Locksmith workshop. Guidelines for performing practical work in the discipline “Plumbing”
Topic 1. Introduction 1. INTRODUCTION. THE ROLE AND TASKS OF THE PRACTICUM ON METAL PROCESSING IN THE SPECIAL AND METHODOLOGICAL TRAINING OF FUTURE TECHNOLOGY TEACHERS. DEMONSTRATION OF PRODUCTS MADE BY STUDENTS DURING CLASSES IN THE FITTING SHOP 2. INTRODUCTION TO THE EQUIPMENT OF THE TRAINING WORKSHOP. ORGANIZATION OF THE WORKPLACE OF A FITTER IN A TRAINING WORKSHOP, ITS TECHNICAL EQUIPMENT AND CONTENT RULES. 3. INTERNAL RULES DURING WORK IN A FITTING SHOP. BASIC RULES FOR SAFETY AND INDUSTRIAL SANITARY. Study questions:
3 LITERATURE ON THE DISCIPLINE: Basic 1. Pokrovsky B.S. Plumbing: Textbook for beginners. vocational education / B. S. Pokrovsky, V. A. Skakun. - 2nd ed., erased. - M.: Publishing center "Academy", p. 2. Home locksmith / Comp. A.P. Alekseev. M.: ZAO Tsentrpoligraf, p. 3. Makienko N.I. General plumbing course: Textbook. for vocational schools. 3rd ed., rev. M.: Higher. school, village: ill. 4. Makienko N. I. Practical work in plumbing: Textbook. manual for environments, prof.-techn. schools M.: Higher. school, village, ill. (Vocational education. Cutting).
4 LITERATURE ON DISCIPLINE continued: additional literature 1. Antonov L.P. and others. Workshop in educational workshops. Textbook manual for pedagogical students. institutes specializing in “General technical disciplines and labor”. M., “Enlightenment”, Muravyov E. M. Plumbing: Textbook. manual for students 811 classes. avg. school 2nd ed., revised. and additional M.: Enlightenment, p.: ill. 3. Pokrovsky B. S. Fundamentals of plumbing: slave. notebook: textbook guide for beginners vocational education / B. S. Pokrovsky. - M.: Publishing center “Academy”, p. 4. Makienko N. I. Plumbing with the fundamentals of materials science. Textbook for training workers in production. Ed. 5th, revised M., “Higher. school", p. from illus. 5. Starichkov V. S. Workshop on metalwork. Textbook manual for training workers in production. 3rd ed., revised. and additional M.: Mechanical Engineering, 1983, 220 pp., ill. 6. Krupitsky E.I. Plumbing. Ed. 4th, revised Minsk, “Vysh. school", p. with ill. 7. L. Sell. Plumbing in questions and answers / Transl. from 7th Polish ed. M. E. Lazutina. Ed. G. E- Taurita.K-: Technzha, s. (B-ka worker).
1. INTRODUCTION. THE ROLE AND TASKS OF THE PRACTICUM ON METAL PROCESSING IN THE SPECIAL AND METHODOLOGICAL TRAINING OF FUTURE TECHNOLOGY TEACHERS. DEMONSTRATION OF PRODUCTS MADE BY STUDENTS DURING CLASSES IN THE FITTING SHOP The main goal of the workshop in educational workshops is to equip students with the knowledge, skills and abilities necessary for a future specialist to successfully implement at school an organic combination of labor education and polytechnic training, and, if necessary, initial vocational training.
Objectives of the workshop in educational workshops: a) training students in the most effective use modern tools, measuring and marking equipment for manual, partially mechanized and machine processing of structural materials (such training includes improving the skills and abilities acquired in high school, mastering new, more complex skills related to the use of tolerance and fit systems, roughness classes, as well as more complex measuring equipment, mastering the control of turning, milling, drilling, planing, grinding metal-cutting machines; thicknesser, planer, lathe and sawing machines for wood, as well as mastering all actions associated with sharpening cutting tools manually and on sharpening machines);
Continuation of question 1 b) training students to choose the most technically and economically feasible methods for manufacturing parts and products in general, to find the most effective technical solutions private technological tasks (for example, the choice of methods for mechanizing the processing of parts, the selection of fixtures and tools, the type of workpieces, options technological processes), i.e., further formation of a creative attitude towards work among students; c) familiarizing students with the basics scientific organization labor when processing structural materials;
Continuation of question 1 d) illustration of teaching methods for the basic operations of manual and mechanized labor in the processing of structural materials, as well as the assembly of components and products; preparation for studying the methods of labor training at school, studying didactics polytechnic education and, finally, preparation for directing the technical creativity of schoolchildren.
The peculiarity of these tasks is their clear professional orientation. The future teacher must not only have a good command of the means of processing structural materials, not only skillfully describe their structure and operation, but also show how the simplest hand tools, as they improve, develop into the working parts of shaping machines, what is the mechanism of their action and what are the connections between processing operations and physics and other basic sciences.
The practicum in educational workshops is built in accordance with the program as a single but comprehensive module, based on the theoretical and general technical training students receive during the first three years of study. At the same time, a scientific, logical and methodological connection is provided with drawing, technology of structural materials, strength of materials, physics, disciplines of the pedagogical cycle, as well as with labor training programs in secondary school. All this work should end with the creation of a well and beautifully designed modern thing (for example, a device, a tool, their parts) that is necessary for the production environment, institute or school.
Continuation of question 1 Training in various techniques for processing structural materials, developing skills and instilling skills are provided using examples of the manufacture of the following products: a) instruments, individual components for them and visual aids, facilitating the study of the basics of science, conducting research at the institute and teaching at school; b) tools and devices to replenish the tool inventory of the institute’s educational workshops and transfer them to schools as samples; c) equipment for sports camps and recreation centers for students and high school students; d) models, the production of which will have to be encountered by the future leader of technical creativity clubs and high school students; e) parts and assemblies ordered by industrial and agricultural enterprises in the production environment of the pedagogical institute.
Continuation of 1 question In the process of completing tasks, future teachers must learn to subordinate their actions in the workshops to certain organizational requirements and labor protection requirements, develop skills of a high culture of work at the machine and workbench, the ability to work purposefully, proactively and productively. During classes in educational workshops, the student must learn to work strictly according to a drawing or technological map, observing the necessary accuracy, quality of processing and using all available and necessary measuring equipment. This does not exclude the creative approach instilled in students throughout all years of study, which is necessary in cases where the documentation contains incomplete data or they are debatable, or, finally, the task itself requires a creative solution. Practicum in educational workshops ends with a test and the assignment of one or two qualification categories (in metal cutting, plumbing or carpentry).
Continuation of 1 question 1. Purpose and objectives of the discipline: The purpose of the discipline is to develop in students the knowledge, skills and abilities of learning how to work with hand tools, machines and technological equipment on the basis of school workshops. Objectives of the discipline: – study of technological and industrial culture when performing plumbing work in school workshops; – study of the essence of the main types of metalworking work, the tool used, the rules for its selection and use, the sequence of metalworking operations, methods of their implementation and mechanization of work, safety rules for metalworking work, requirements for the quality of processing parts, types of tool wear, typical defects, their causes appearance and methods of prevention;
Continuation of question 1 - the formation of skills and abilities: choose processing modes taking into account the characteristics of metals and alloys, observe the technological sequence when performing metalwork work: marking, cutting, straightening, bending, cutting and filing metal, scraping, drilling, countersinking, countersinking and reaming holes , threading, riveting, soldering, tinning and gluing; – preparing students to use the knowledge and skills of metalworking in professional teaching activities.
Continuation of question 1 As a result of studying the discipline, the student must: Know: educational programs and textbooks on metalworking; educational technologies necessary for organizing the educational process in educational institution, extracurricular and extracurricular activities; requirements for equipment and equipment of classrooms; subject content to the extent necessary for teaching in basic, senior, including specialized schools; main types of hand tools, machines and technological equipment, used in educational process;
Continuation of question 1 Be able to: use the main types of hand tools, machines and technological equipment; perform basic types of work on maintaining educational equipment in school workshops; conduct practical work with schoolchildren in the field of metalworking; Possess: basic concepts and techniques in the sections of the discipline “Practicum plumbing”.
Continuation of question 1 The role and place of plumbing work in industrial production The profession of “mechanic” at a modern machine-building enterprise is one of the most common. Each group of mechanics is characterized by knowledge and professional skills specific to their work. However, the main basis for each locksmith is mastery of general locksmith operations, which represent the “framework”, the “building blocks” of locksmith skills. These include marking, cutting, straightening, bending, cutting, filing, drilling, countersinking and reaming holes, threading, scraping, lapping and finishing, riveting and soldering. These operations are performed with hand and mechanized tools, which every mechanic should be able to use.
2. FAMILIARIZATION WITH THE TRAINING WORKSHOP EQUIPMENT. ORGANIZATION OF A WORKPLACE FOR A FECTER IN A TRAINING WORKSHOP, ITS TECHNICAL EQUIPMENT AND CONTENT RULES Organization of a work place for a mechanic in a training workshop Under rational organization workplaces understand the creation of conditions for achieving high labor productivity and excellent product quality with the least expenditure of effort and money, as well as guaranteed labor safety. Rational, taking into account the requirements of the NOT, the placement of tools, devices, as well as the necessary equipment requires dividing them into items of permanent and temporary use and assigning storage places to the tools and devices.
Continuation of question 2 The tool, workpiece and documentation for this work should be placed on the workbench at arm's length. Each subject is strictly specific place. The placement of the tool should ensure a minimum of rotation for the worker. The workplace should be provided with good lighting. The tool should be stored in the drawers of the workbench in such an order that the cutting tools (files, taps, drills, etc.) do not deteriorate, and the measuring tools (squares, calipers, micrometers, etc.) do not deteriorate from nicks, scratches and impacts. After finishing work, used tools and devices are cleaned of dirt and oil and wiped.
Continuation of 2 questions Technical equipment of a mechanic's workplace In contrast to the workplace of a factory mechanic, which is called a section of the workshop with equipment located on it, intended to perform only certain operations, for a student trainee, this is an area of training workshops with a workbench, a vice mounted on it, a calibration and marking plate, a cabinet or board on which the most commonly used tool is mounted. The main equipment of a mechanic's workplace is, as a rule, a single workbench with a vice installed on it (Fig. 1.1). The workbench must be strong and stable, its height must correspond to the height of the worker.
Continuation of 2 questions Fig Single bench: a - general view: 1- screw for raising and lowering the adjustable vice; 2 - tool box; 3 - plane-parallel vice; 4 - tool shelf; 5 - protective screen; b - tablet for the tool; 7 - edge made of steel angle; 8 - drive handle for vertical movement of the vice; b - arrangement of plumbing tools on the workbench
The following types of bench vices are most widespread when performing metalwork work: chair vice, parallel (rotary and non-rotating) and high-speed pneumatic vice. Chair vices (Fig. 1.2) are designed to perform heavy work involving high impact loads, for example, chopping, bending, riveting. Fig. Chair vice: 1 - workbench; 2 - fastening bar; 3 - fixed sponge; 4 - movable sponge; 5 - clamping screw; b - handle; 7 - flat spring; 8 – rod
Continuation of 2 questions Fig. Parallel rotary bench vice: 1 - base plate; 2 - rotating part; 3 - fixed sponge; 4 - movable sponge; 5 - lead screw nut; 6 - guide prism; 7 - lead screw; 8 - T-shaped circular groove; 9 - axis; 10 - bolt; 11 - handle; 12 - nut
Continuation of question 2 Organization of the workplace There are certain requirements for the placement of tools, workpieces and materials in the workplace: only those tools, materials and workpieces that are necessary to perform this work should be at the workplace; tools and materials that the worker uses frequently should be located closer to him; tools and materials used less frequently should be located in areas marked by arcs with a radius of approximately 500 mm; tools and materials used extremely rarely should be located in distant areas. Their reach is ensured only when the worker’s body is tilted.
Continuation of 2 questions Fig. Location of convenient and inconvenient zones in the workplace (all dimensions are indicated in millimeters): a, b - on the workbench: 1, A - comfortable; 2, B - less comfortable; 3, B - uncomfortable; c - convenient and inconvenient height reach zones
Rules for maintaining the workplace Before starting work, it is necessary to: check the serviceability of the workbench, vice, devices, individual lighting and mechanisms used in the work; read the instructions or technological map, drawing and technical requirements for the upcoming work; adjust the height of the vice according to your height; check the availability and condition of tools, materials and workpieces used in the work; place on the workbench the tools, workpieces, materials and devices necessary for the work.
During work it is necessary: to have on the workbench only those tools and devices that are currently in use (everything else should be in the drawers of the workbench); return the used tool to its original place; Maintain cleanliness and order in the workplace at all times. At the end of the work, it is necessary to: clean the tool from shavings, wipe it, put it in cases and put it in the drawers of the workbench; clean the workbench tabletop and vice from shavings and dirt; remove unused materials and workpieces, as well as processed parts, from the workbench; turn off individual lighting.
3. INTERNAL RULES DURING WORK IN A FITTING SHOP. BASIC RULES FOR SAFETY AND OCCUPATIONAL SANITATION General information on labor safety when performing plumbing work, work only with serviceable and sharpened tools; When working on sharpening machines, be sure to wear safety glasses or a protective shield with a lock. Do not allow sharpening wheels to run out. Monitor the serviceability of exhaust devices; cutting in a vice should only be done if there is a protective mesh or screen on the workbench; work in a headdress and overalls; lift heavy parts only with two people. Do not place heavy parts on the edge of the workbench; do not blow away sawdust, do not brush off the shavings with your hand, but use a broom brush for this;
Continuation of question 3: Before starting to work on machines and power tools, check them at idle speed and only after that secure the tool; work only in good lighting; When working with electrified tools from a mains voltage above 36 V, be sure to use rubber gloves and a rubber mat; work on machines only if there are working parts guards; after working with oils, lubricants, coolants, acids, alkalis, soda, fluxes, adhesives, etc., be sure to wash your hands hot water with soap;
Continuation of Question 3: If you receive minor injuries, be sure to treat the wound with iodine and apply a bandage; work using acids, alkalis, fluxes, etc., as well as work associated with the release of dust, smoke, gases, must be performed in a well-ventilated area or under an exhaust hood; do not go out into a draft in a hot state after work; When performing work, observe all labor safety rules specified in the instructions and technological maps.
Continuation of question 3 Industrial sanitation involves the creation of conditions at work that provide the required temperature in production premises, good ventilation, sufficient illumination of workplaces, absence of drafts, the presence of auxiliary and household premises. Basics of industrial sanitation To maintain health and prevent diseases, it is necessary to: take short breaks during work to relieve fatigue (in addition, it should be borne in mind that after working while standing, you need to rest while sitting, and vice versa); get at least 8 hours of sleep per day; during work, change your working position from time to time; After finishing the working day, wash your entire body in the shower with soap.
Starichkov Vladimir SemenovichThis textbook, unlike other textbooks and manuals on plumbing, contains detailed description specific working techniques and methods of practical implementation of basic plumbing operations and types of work in a certain technological sequence. Tutorial intended for industrial training instructors to assist in conducting practical training in the training of mechanics of various specialties: mechanics mechanical assembly works, instrumentation and automation mechanics, repairmen, car repair mechanics and workers in other specialties. The textbook covers the material of the basic work of the general locksmith course and corresponds to the topics curriculum.
The file will be sent to selected email address. It may take up to 1-5 minutes before you received it.
The file will be sent to your Kindle account. It may take up to 1-5 minutes before you received it.
Please note you"ve to add our email [email protected]
to approved e-mail addresses. Read more.
You can write a book review and share your experiences. Other readers will always be interested in your opinion of the books you"ve read. Whether you"ve loved the book or not, if you give your honest and detailed thoughts then people will find new books that are right for them.
BBK 34.671 C 77 UDC 683.3 (075) Reviewer N. I. Makienko Starichkov V. S. C77 Workshop on metalwork work - Education benefits? pp “training workers in production L?”! T * “Add. - m.. Mechanical engineering Ss!- 220 e%P*P In lane: 80 k, s2704080000-181 038(01)-83- Sh "M BBK- 34-671 6P5.4 © Publishing House "Machine Building", 1983 PREFACE The resolution of the Central Committee of the CPSU and the Council of Ministers of the USSR dated June 21, 1979 “On measures to further improve the training and advanced training of workers in production” sets the task of improving the quality of vocational training and education of workers in production and creating conditions for continuous. improving their skills in accordance with the requirements social development and scientific and technological progress. This textbook, unlike other textbooks and manuals on plumbing, contains a detailed description of specific working techniques and methods of practical implementation of basic plumbing operations and types of work in a certain technological sequence. The training manual is intended for industrial training instructors to assist in conducting practical training in the training of mechanics of various specialties: mechanical assembly mechanics, instrumentation and automation mechanics, repairmen, car repair mechanics and workers of other specialties. The textbook covers the material of the main works of the general mechanics course and corresponds to the topics of the curriculum. The material on each main issue provides for mastering the skills of performing preparatory, auxiliary and basic operations and types of work characteristic of the locksmith profession being mastered by the worker. The study of operations is carried out sequentially from simple to more complex. To master the initial skills in individual techniques and operations of marking, chopping, cutting, filing, etc., training exercises should be performed when necessary. The manual contains a detailed description of production operations, techniques and methods of work with specific recommendations on what and how to do. When performing operations, the use of mechanized tools and various devices is provided to increase labor productivity and product quality. To control production work and compliance technical requirements It is necessary to follow the rules of application and techniques for using control and measuring instruments and instruments. Special attention The manual focuses on occupational safety requirements. -At the end of each chapter there are test questions, which are used by the industrial training instructor to check mastery educational material. I* GENERAL OCCUPATIONAL SAFETY AND WORKPLACE ORGANIZATION REQUIREMENTS During industrial training classes at enterprises, the instructor must provide detailed instructions, monitor compliance with occupational safety requirements and ensure that each student understands these rules and instructions. The instructor must provide training sessions warning posters about occupational safety requirements, hanging them in prominent places; in necessary cases, students should be provided, depending on the educational and production tasks they perform, with written instructions on labor safety requirements, industrial sanitation and fire safety. There are certain requirements for organizing a mechanic's workplace. 1. The workbench must be durable and stable. Tabletop. The (cover) of the workbench should be flat and covered over the entire plane with sheet steel, textolite or linoleum, and the edges should be covered with angle steel or wooden slats. A replaceable (retractable) mesh screen must be installed on each workbench to protect those working nearby from fragments flying off during cutting. 2." Parallel rotary vices must be firmly and reliably mounted on the workbench. In the compressed position, the jaws are parallel and at the same level. The overhead jaws are firmly fixed, well hardened and have a clear cut to securely fasten the part. The part should only be clamped in the vise using the force of your hands, not your body weight. When releasing the parts from the vice, the lever must be lowered smoothly, without throwing it, so as not to hurt your arm or leg. Keep the vice clean and in good condition, and the rubbing parts should be regularly lubricated with appropriate lubricant. A footrest should be used in cases where the height of the vice does not correspond to the height of the student. The height of the workbench with the vice is considered normal if the student’s arm, bent at the elbow joint at an angle of 90°, is at the level of the jaws of the vice when it is in a vertical position. shoulder part. The selected supports should lie tightly on the floor. Incorrect position of the student’s body causes rapid fatigue and makes it difficult. correct execution working methods and obtaining the required accuracy. 4. -One of the elements of workplace culture is properly fitted, neat and clean workwear. A robe or 4-piece overalls must be selected according to the size and height of the worker and should not restrict movement. During work, overalls should always be buttoned with all buttons, and the sleeves should have fastened cuffs that tightly cover the wrist; You must wear a headdress (beret or scarf) on your head, under which you must carefully tuck your hair away. There should be no hanging ends on clothes and headwear (ties, ribbons, ends of scarves) that could be caught in rotating parts of machines, machines or mechanisms and lead to an accident. 5. Local lighting at the workplace must have serviceable movable fittings with a protective shade to direct the light onto the workpiece and the plane of the workbench. The voltage in the electrical network during local lighting should not be "G! ~ , l R Fig. 1. Diagram explaining the principle of exceeding do B. location of tools, workpieces - 6. Only those tools and devices MUST be at the workplace, documentation that are necessary to complete the educational and production task. Each tool, fixtures and materials must have its own specific place. Tools, fixtures and materials must be located on the workbench in such a way that everything that is taken. right hand, was to the right of the worker, with his left hand - to the left. More often than others, the tools and workpieces used must be located closer to the person working (Fig. 1). Certain order should be supported and in a drawer, where each tool should be allocated permanent place. Measuring and testing tools are placed separately from the working tool on a special shelf or tablet. Drawings and maps for educational tasks should be placed on a tablet stand installed on a workbench, at a distance sufficient for reading them. MARKING FLAT SURFACES Occupational safety requirements" When starting to learn how to mark flat surfaces, the instructor must carefully inspect all tools and devices. It is prohibited to work with a faulty or improperly sharpened tool. Tools in use must meet the following requirements. Hammers must be firmly seated on the handles and wedged in the holes with steel wedges. The hammer handle should have an oval cross-section with a uniform thickening towards the end. The surface of the handle must be clean and smooth, without knots, cracks or chips. The length of the handle for marking hammers weighing 200 g should be 250-300 mm. The working surfaces of the hammer must have a smooth, even surface, without cracks or chips. The impact part of the punches should not be knocked down or beveled from impacts. The surface of the striking part should be smooth and slightly convex. The length of the punch must be at least 70 mm so that the striking part of the instrument taken in the hand is 20 mm above the yals. The working part of the punch should be a sharpened tip with an apex angle of 60°, and for marking the centers of holes to be drilled, with an apex angle of 45°. You cannot use a dull center punch, since when you hit it with a hammer, the point will slide off the marking plane and can cause hand injury. Impacts should be applied to the striking part along the axis of the punch when it is perpendicular to the plane of the workpiece. To prevent hand injuries, you must carefully handle the pointed ends of the compass, scriber and center punch; these tools must not be placed in clothing pockets. Let's consider the labor safety requirements when working on sharpening machines. General requirements. 1. Operate only a machine to which you are authorized to perform the work assigned to you. 2. It is prohibited to work on the machine wearing mittens or gloves, as well as with bandaged fingers. 3. If there is a power outage, immediately turn off the electrical equipment of the machine. 4. Every worker is obliged; a) strictly comply with all labor safety requirements; b) keep it clean workplace throughout the working day; c) do not wash your hands in oil, emulsion and kerosene; d) do not eat at the machine. Before you start. 5. Before each start of the machine, make sure that starting the machine does not endanger anyone. 6. Put your work clothes in order. 7. Check the strength of the guard fastening." It is prohibited to work without the guards of the grinding wheel and belt drive. 8. Check the reliability and correct fastening of the tool rest (the gap between the tool rest and the grinding wheels should be no more than 3 mm), check the condition of these wheels by external inspection to determine noticeable cracks and potholes. It is prohibited to use wheels that have cracks and potholes. 9. Check the proper operation of the machine at idle for 3-5 minutes, standing away from it. danger zone possible rupture of the grinding wheel, and make sure that there is no excessive radial or axial runout of the wheel. 10. If you discover a malfunction of the machine or a possible danger, immediately inform the instructor or foreman. While working. 11. When sharpening a tool, it is necessary to move the tool onto the wheel smoothly, without jerking or strong pressure. You should stand away from the plane of rotation of the grinding wheel. 12. When working, the worker must use protective glasses or shields. 13. Sharpening and finishing of tools with grinding wheels* should only be done with cooling. During work, to increase the service life and safety of tools, it is necessary: 1. Protect the tool from mechanical damage ( nicks and scratches on working edges, scales, measuring surfaces). 2. When using a compass, the locking screws should be unscrewed only one turn. 3. The surface of the marking plate must always be clean and smooth; After finishing work, you must: 1. To prevent corrosion, wipe the tool dry with a clean cloth, and then lubricate it with a thin layer of oil. 2. Store the measuring tool in cases (each tool must have its own place. It is prohibited to store the tool in bulk 3). Wash the marking plate with kerosene and wipe with a dry, clean cloth, lubricate with oil and cover with a protective wooden cover. Preparing surfaces for marking. Marking work in plumbing is an auxiliary technological operation consisting in transferring contour structures according to the dimensions indicated in the drawing to the workpiece. The marking exercise is usually performed on plates of sheet steel, and the two adjacent edges of each plate should be straight and located at an angle of 90°. The surfaces are prepared for marking in the following sequence. 1. Preparation of dyes. To paint untreated surfaces (castings, forgings, rolled products), a chalk solution is used (ground chalk is diluted in water). To protect the paint layer from abrasion and for its quick drying, wood glue is added to the dye composition (600 g of chalk and 50 g of wood glue per 4 liters of water). Cleanly processed surfaces of products are painted with a solution of copper sulfate (two to three teaspoons of copper sulfate crystals in glasses of water) or a special varnish for marking. F 2. Preparing the workpiece for painting. When preparing workpieces for painting, they are cleaned of dust, dirt, scale and rust with a steel brush. The plates must be free of burrs and sharp corners . One plate is cleaned on both sides with sandpaper, and the planes of the remaining plates are left untreated. 3. Painting surfaces. When applying the dye (Fig. 2), the workpiece is held in the left hand in an inclined position. A thin and uniform layer of dye is applied to the plane with cross vertical and horizontal movements of the brush. The solution should be applied only with the end of the brush in small quantities to avoid the formation of smudges. The cleaned surfaces are painted with a solution of vitriol, and the untreated surfaces are painted with chalk; painting the plate is necessary Fig. 2. Applying the dye during the preparation with a solution. After finishing, dry. Applying parallel marks. Marks are applied at an arbitrary distance from each other using a scriber using a square with a heel in the following sequence. 1. The plate is placed on the marking plate so that the processed edge, which is taken as the marking base, faces the worker. For a tight fit of the square, the workpiece must be moved to the edge of the marking plate (Fig. 3, a). , 2. A square with a wide base is applied to the base edge and the first mark is drawn with a scriber. When applying marks, the tip of the scriber is pressed tightly against the edge of the square (Fig. 3, b), while simultaneously tilting the scriber towards the direction of movement. To obtain a clear and straight line, the mark should be applied with slight pressure, without changing the inclination of the scribe relative to the narrow edge of the square. You cannot follow the same risk twice, as the line will turn out to be forked. To apply marks, two types of scribers are used; round (Fig. 4, b) or with an insert needle made of hard alloy (Fig. 4, c). 3. The square is moved along the edge of the plate at arbitrary distances and a series of marks are applied. Parallel marks at a given distance from each other are applied using a measuring ruler and scriber. Rice. 3. Positions of the square with the heel on the plate (a) and the tip of the scriber at the edge of the square (b) 8 According to the sketch (Fig. 5), all dimensions are set aside from the bottom line, which is taken as the base line, and markings are made in the following sequence. 1. Using a measuring ruler and a scriber, two marks a are applied to the plate at a distance of 5 mm from the base line (the method is shown in Fig. 6, a). v^^shsh) %^DVD £ Fig. 4. Applying marks using a scriber: a - method of work; b - round scriber; c - scriber with insert needle^ 1 - needle; 2 - body; 3 - spare needles; 4 - plug 2. Place a ruler on the marked plane so that its edge coincides with the strokes of marks a. With the widely spaced fingers of the left hand, press the ruler against the plate, and with the right hand apply a mark with a scriber (Fig. 6, b). Similar markings for marking are performed for the rest parallel lines, located at a distance of 6, 13, 21, 29, 38, 47, 55 mm from the baseline (Fig. 6, a), and draw risks. 3. The accuracy of applying marks according to the given dimensions is checked, ----- з p h^ Д» 1, S5 "-а * - 5" / E^ "<Г i и и *Г~^ф гд Рис ныл. 5. Пример рисок ^ 1 разметки параллель* измерительной линейкой Перпендикулярные риски (рис. 7) наносят разметочными инструментами - угольником, линейкой и чертилкой. 1. Параллельно нижней границе пластинки проводят риску АВ длиной 75 мм, которую принимают за базовую линию (рис. 7). 2. От точки А по измерительной линейке откладывают расстояние 48,мм и чертилкой делают отметку (точка О). 3. На линию А В накладывают линейку, к ребру которой плотно приставляют ребро плоского угольника (рис. 8), чтобы вершина угла совпадала с точкой О, и проводят риску О-0Х длиной 50 мм (см. рис. 7). 4. Таким же способом проводят линии В-Вг и А-А{ и получают три линии, перпендикулярные основанию АВ. ^ При разметке углов Нанесение рисок под заданными углами. применяют циркуль, линейку и чертилку. * Рассмотрим последовательность разметки угла 45°. 1. С помощью плоского угольника строят угол 90° ВАС (рис. 9). 2. Циркуль раздвигают на произвольный размер R < АВ. Рис. 6. Прием откладывания размеров от кромки заготовки (я) я иаиесе- ния параллельных рисок (б) 3. Острие циркуля ставят в точку А (вершину угла) и установленным радиусом наносят дугу, пересекающую стороны угла в точках 1 и 2. 4. Из точек / и 2 одним и тем же произвольным радиусом наносят перекрестные дуги а и b с точкой D в месте пересечения. Рис. 7. Пример построения взаимно перпендикулярных рисок по заданным размерам Рис. 8. Прием построения угла 90*? с помощью плоского угольника, линейки и чертилки 5. С помощью линейки и чертилки из вершины угла А через точку D проводят риску, которая делит угол 90° на два равных угла по 45°. Возможно совмещенное построение углов в 30, 60 и 120°. 1. На базовую риску АВ наносят среднюю точку О (рис. 10). 2. Циркуль раздвигают на произвольный размер (не более отрезка ОВ). 10 3. Опорную ножку циркуля ставят в точку О (вершина угла) и установленным радиусом проводят дугу, пересекающую базовую линию АВ в точке 1. 4. Из точки 1, не изменяя величины радиуса, делают циркулем на дуге метку (точка С), необходимую для построения угла 60°. 5. Через точки О и С с помощью линейки чертилкой проводят риску (LCOB = 60°). 0 Рис. 9. Пример разметки угла 45° Рис. 10. Пример построения углов 30, 60 и 120° 6. При построении угла 120° используют разметку угла 60° и тем же радиусом делают вторую засечку по дуге, образуя точку D, а затем приставляя к основанию ОС второй угол 60°. Таким образом, точка D будет исходной для построения угла 120°. Риска OD образует угол 120°. Рис. 11. Нахождение центра окружности с помощью цеитроискателя: а - нанесение первой риски; б - нанесение второй рнски; в - определение положе» ния центра Разметку угла 30° выполняют на базе [_AOD - 60° в следующем порядке. 1. Из точек О и D одним и тем же произвольным радиусом наносят перекрестные дуги, образуя точку Е. 2. Через точки О и Ё проводят прямую риску, которая делит угол [_AOD на два угла по 30°. Нанесение окружности, деление ее на равные части и построение многоугольников. Учебное задание 1 заключается в нахождении центра"окружности с помощью угольника-центроискателя(рис. 11, а). Угольник состоит из двух планок, соединенных под углом 90°, и жестко укрепленной линейки, рабочее ребро которой делит угол 90° пополам. И Разметку выполняют в следующей последовательности. 1. Деталь устанавливают на разметочную плиту так, чтобы размечаемый торец был сверху. 2. На верхний торец детали накладывают угольник-центроиска- тель так, чтобы две его стороны (планки) касались цилиндрической поверхности детали. 3. Левой рукой плотно прижимают линейку угольника к поверхности торца, а правой проводят чертилкой первую диаметральную риску. 4. Угольник-центроискатель поворачивают по цилиндрической поверхности детали примерно на 90° и проводят чертилкой вторую диаметральную риску (рис. 11, б). Точка~ пересечения двух рисок будет центром размечаемой окружности (рис. 11, в). Рис. 12. Способ проверки точности разметки центра окружности разметочным циркулем Рис. 13. Пример деления окружности на четыре части с построением вписанного квадрата Разметку центра детали с грубо обработанной цилиндрической поверхностью производят в такой же последовательности. В этом случае для более точного нахождения центра окружности необходимо нанести пять-семь рисок, и центром будет точка, в которой пересекается наибольшее число рисок. Точность разметки центра окружности проверяют разметочным циркулем (рис. f2). Острие одной ножки циркуля устанавливают в размеченный центр, а другую ножку перемещают так, чтббы ее острие слегка касалось цилиндрической части детали. Если острие ножки циркуля касается детали по всей длине окружности, то центр размечен правильно. Учебное задание 2 представляет собой деление окружности на четыре равные части с построением вписанного квадрата (рис. 13). 1. В центре размечаемой плоскости циркулем проводят окружность R = 28 мм (радиус может быть произвольным). 2. Церез центр окружности по линейке проводят прямую риску, чтобы она пересекла окружность в двух точках Л и В и разделила ее на две равные части. 3. Опорную ножку циркуля устанавливают в точку А и, раздвинув циркуль на расстояние несколько большее, чем половина отрезка АВ, проводят дугу ), where the length of the arc between them will be equal to one third of the circumference. 4. By connecting the points with straight lines CD, CB and BD, an inscribed equilateral triangle is obtained. 1 Fig. Fig. 15. Dividing a circle into three parts with the construction of an inscribed triangle Fig. 16. Dividing a circle into six parts with the construction of an inscribed hexagon Fig. 14. Method of marking a square 5. The correctness of the construction is checked with a compass, setting the opening of the compass equal to the length of one of the sides of the triangle and with the same size determining the equality of the remaining sides of the triangle. Training task 4 (Fig. 16) is a division of a circle into six parts with the construction of an inscribed hexagon (Fig. 17). 1. In the center of the marked plane, a circle R = 27 mm is drawn with a compass (the radius can be arbitrary). . 2. Using a ruler, draw a mark passing through the center of the circle and intersecting it at points A and B. 13 3. From point A, as from the center, draw an arc with a radius equal to the radius of the drawn circle, and get points / and 2. A similar construction is made from point B, plotting points 3 and 4. The resulting intersection points and end points of the diameter will be the desired points for dividing the circle into six parts. 4. By connecting the points with straight lines A-2, 2-4, 4-B, B-3, 3-/ and 1-A, an inscribed hexagon is obtained. When marking the faces of a hexagon to the size h of the wrench mouth (Fig. 17), the radius of the circumscribed circle of the inscribed hexagon is determined by the formula R = 0.577/z. Marking the contours of workpieces with dimensions measured from the edges and the center line. Techniques for planar marking of various contours of parts depend on the chosen Fig. Fig. 17. An example of marking a hexagon for the size of the jaw of a wrench mShpodt" Fig. 18. Marking the square of the marking base, the shape of the part and the sequence of its processing. After the drawing of the part has been studied, in most cases the outer edges of the workpieces or the center (axial) ones are taken as marking bases. lines. Training task 1 contains the marking of a flat square with dimensions measured from the edge of the workpiece. The marking is done using a ruler, a compass and a scribe in the following sequence: 1. An allowance (2 mm) is set aside from the side edge of the plate for further processing and a mark is applied along the edge. (Fig. 18). a set aside a size of 100 mm (point /) and on the mark b - a size of 63 mm (point 2). 5. From the point / perpendicular to the mark a, apply a mark intersecting the mark ah. Similarly, a mark is made from point 2. 6. At the top of the internal corner, 90° parallel to the marks a and b (at a distance of 2 mm from them, marks a2 and b2 are drawn. 7. From the top of the inner corner, a corner groove 2 mm wide is marked, completing the marking of the entire contour flat square. And Training task 2 consists of marking the end of the flange with dimensions measured from the axial (center) line (Marking is carried out on the same plate as marking the flat square 1. According to the drawing (Fig. 19), the marking base is taken. center lines 2. At a distance of 30 mm from the boundaries of the square contour, draw two perpendicular marks intersecting at point O. Fig. 19. Marking the flange Fig. 20. Method of marking the part from the center line 3. From point O, draw circles R = 10 , 17, 25 mm (Fig. 20). Points 1-4 of intersection of the circle R = 17 mm with the axial lines will be the centers of circles R = 3 mm. 4. By constructing circles R * = 3 mm, marking the parts according to the drawing is completed. according to a template. In mass production, marking templates are used to increase labor productivity when performing marking work. Rice. 21. Wrench template Fig. 22. Reception of marking a template The sequence of marking a wrench according to a template is as follows. 1. A marking template (Fig. 21) is applied to the workpiece so that it fits tightly to the plane of the workpiece along the entire contour. To prevent the template from moving, it is strengthened with two clamps (Fig. 22). 2. The workpiece is placed on the marking plate and the entire marked contour is traced along the edge of the template with the tip of the scriber. Particular attention should be paid to the correct position of the scribe relative to the side edge of the template. To ensure that the marking accuracy of the wrench is ensured, the tip of the scriber must be located at the apex of the angle formed by the face of the template and the plane of the workpiece. Construction of developments of bodies in the shape of a cube, cylinder and cone. Sometimes a mechanic has to make products in the shape of a cube, cylinder and cone from sheet metal When manufacturing products of this shape, the first operation will be to construct the development of surfaces according to the main specified dimensions of the figures. This exercise consists of three tasks. Training task 1 contains the construction of a development of a cubic vessel on sheet steel 100./ Fig. 23. . An example of constructing a development of a cubic vessel i> A g 1 "and -■-i-| * ! з к / ^г в The development of the surface of a cubic vessel can be obtained if the side faces /-4 are rotated from a vertical position to a horizontal one (Fig. 23). "The sequence of completing the task is as follows: 1. Mutually perpendicular axial lines A B and CD are applied to the metal sheet (Fig. 24). 2. Starting from the base lines, construct a square 5 with a side of 100 mm. 3. Build squares 1-4. 4. To connect the planes at the two sides of squares 3 and 4, mark an allowance for a rivet seam 10 mm wide. Training task 2 contains the construction of a development of a cylindrical vessel on sheet steel. The development of the surface of the cylinder will be a rectangle with a height equal to the height of the cylinder and a length equal to the circumference of the cylinder. The sequence of completing the task is as follows: 1. Determine the development length of the cylinder 0 70 (Fig. 25): L = nD 3.14-70 = 219.8 mm (rounded to 220 mm). 2. Construct a development of the cylindrical surface of the vessel with height H = 120 mm and length L = 220 mm (Fig. 25, a). 16 3. The development of the cylindrical surface is supplemented with allowance a for the side seam. To flange the upper edge of the cylinder with rolled wire, take an allowance b = nd (d is the diameter of the wire). 4. Mark the bottom of the vessel (Fig. 25, b), to do this, apply two circles R = 35 mm (base of the cylinder) and R = 35 + a (with seam allowance), thereby completing the complete marking of the development of the cylindrical vessel. >| L, !<■- R35+a ^R - " i i -- T R35 L-220 a) Рис. 25. Цилиндрический "сосуд: a - развертка цилиндрической поверхности; б - основание Учебное задание 3 содержит построение развертки поверхности конуса. Конус (рис. 26) состоит из двух частей: круга радиусом г и кругового сектора (развертка боковой поверхности конуса) радиусом R, равным длине образующей. Развертку поверхности конуса можно разметить двумя способами. При первом способе за базу развертки берут угол А кругового сектора (рис. 27). Зная радиус т = 30 мм основания конуса и длину R = 90 мм образующей конуса, разметку выполняют в следующей последовательности. 1. Угол ВАС рассчитывают по формуле ВАС = 360 rlR =» 360-30/90 - 120°. 2. Из произвольной точки О наносят две риски ОВ и ОС под углом 120° друг к другу (рис. 27, а). 3. Раствор циркуля устанавливают на размер R = 90 мм и из точки О наносят дугу до пересечениям угловыми рисками, образуя точки В и С. 4. Для получения полной развертки конуса к круговому сектору добавляют припуск на шов (штриховой контур на рис. 27, а). При втором способе за базу разметки принимают длину дуги кругового сектора. Последовательность выполнения задания заключается в следующем. 1. Из точки О радиусом R = 90 мм наносят часть окружности - дугу В (рис. 27, б). 17 Рис. 26. Эскиз ко- и уса 2. Окружность основания конуса делят на произвольное число равных частей, например на 16 равных дуг, где а - 1/16. 3. На дуге С из произвольной точки А 16 раз откладывают дугу а и получают точку В. 4. Прочерчивают прямые риски А-О и О-В и получают развертку боковрй поверхности. 5. Для получения полной развертки конуса устанавливают припуск на швы (штриховая линия на рис. 27, б). 6. Размечают основание конуса. Для этого из произвольной точки наносят окружности г = 30 мм и г = 30 мм + припуск на шов и тем самым завершают разметку второй детали конуса /рис. 27, в). Ри. 27. Примеры построения развертки конуса: а - первый способ разметки (базой является угол А); б - второй способ рае- Йеткн (базой является дуга В); в - раз» Ьетка площади основания конуса Кернеиие разметочных линий. Операция кернения заключается в выполнении кернером небольших углублений по линиям - ри- скам. Рабочая часть разметочных кернеров имеет угол заточки конусной части 45-или 60°. Кернение необходимо главным образом для контроля правильности произведенной обработки. Расстояние между керновыми углублениями выбирают на глаз в зависимости от длины и вида разметочных линий: на прямых линиях - на расстоянии 15-20 мм; на окружностях и дугах - на расстоянии 5-10 мм. Точки сопряжения и пересечения обязательно кернят. На обработанных поверхностях точных изделий разметочные риски не кернят. Учебное задание 1 содержит кернение рисок обыкновенным кернером (рис. 28). Последовательность выполнения задания. 1. Размечаемую заготовку укладывают на плиту таким образом, чтобы риска, подлежащая кернению, была направлена прямо к работающему. Молоток держат правой рукой, а кернер-левой. 2. Установку кернера на риску и кернение выполняют в два приема. Сначала при установке кернера на риску (рис. 28, а) работающий наклоняет его немного от себя, устанавливая острие точно 18 на середину риски или же в точку пересечения. Затем, не сдвигая кернер с риски (рис. 28, б), работающий ставит его перпендикулярно разметочной плоскости и наносит по кернеру легкий кистевой удар молотком (рис. 28, в). Рис. 28. Установка кернера: а - наклонно (первое положение); б - вертикально (оторое положение); в - нанесение ударов молотком при кернеинн a) S) в) Перемещая кернер для последующего кернового углубления, следует вторично установить острие в углубление риски и почти без усилия переместить его по риске на необходимое расстояние. Острие кернера в этом случае, не сбиваясь с направления, хорошо скользит по риске. D> > a) e) Fig. 29. How to work with a spring or electric punch: a - installing the punch on a score with an inclination; b - vertical installation of core recesses; - c - spring punch (d - electric punch A similar technique when moving can be applied to intersecting marks, where when moving, the tip of the punch will find the deepening point of two intersecting marks. Training task 2 consists of punching marking marks with a spring or electric punch (Fig. 29 These punches, compared to conventional ones, provide increased accuracy of 19 punching and obtaining small depressions of the same size, increase labor productivity, and facilitate the work of the worker. The task is performed in the following sequence: 1. The tip of the spring punch is placed exactly in the middle of the groove or at the intersection point. mark, slightly tilting the center punch towards itself (Fig. 29, a). 2. The spring center punch is installed perpendicular to the marked plane, without moving the tip of the center punch from the mark (Fig. 29, b). Lightly press the cap with your fingers. the spring will hit the striker rod, the tip of Fig. 30. Sharpening the center punch: Fig. 31. Checking the sharpening of the core “a - position of the hands; b - placement of a conical part according to the template - on the plane of the abrasive wheel which will make a core recess. The impact force of the center punch is regulated by turning the cap (compressing or loosening the spring). All conical recesses are the same size, since the impact force is always the same for one adjustment. 4. The center punch is removed from the surface of the part to be marked and returned to its original (working) position. 5. The core is moved along the mark and the techniques for installing and applying core recesses are repeated sequentially along the length of the marking lines. The sequence of operation with an electric punch is similar to that discussed above (to perform punching, you need to press the punch body down). Sharpening the tserner, scriber and compass legs. The quality of marking largely depends on the serviceability and correct sharpening of the marking tool. Before you begin, you need to study the safety requirements for working on sharpening machines, set out at the beginning of this chapter. The center punches (Fig. 30) are sharpened in the following sequence. 1. Put on safety glasses and turn on the electric motor of the sharpening machine. 20 2. The punch is taken by the middle with the left hand, and by the end opposite to the one being sharpened with the right hand. 3. Maintaining the angle of inclination relative to the grinding wheel, apply the center punch with a cone to the rotating wheel with light pressure, and evenly rotate the center punch around its axis with the fingers of the right hand. The position of the center punch axis relative to the circle should not change until a regular cone with a sharp apex is formed. The tip of the punch is periodically cooled in water to avoid releasing its working part. 4. Checking the correctness of sharpening is carried out using a template (Fig. 31). Rice. 33. Sharpening compass legs: a - work procedure; b - sample of sharpening the legs of a compass. The scriber (Fig. 32) is sharpened in the same sequence as the center punch. Let's consider the sequence of sharpening the compass legs (Fig. 33). 1. The compass is taken with the left hand in the middle, below the arc with the locking screw, and with the right hand - by the hinge joint of the two legs (the legs should be in close contact), 21 - 2. With light pressure, the compass is brought to the grinding wheel so that the leg the compass was at a certain angle in relation to the circle, and the end of the first leg was sharpened; then the position of the legs is changed and the end of the second leg is sharpened. After sharpening on a grinding wheel, the sharp ends of the legs of the compass are polished on a block, while simultaneously removing burrs on the inner planes of the legs and on the side faces of the conical part. When sharpened correctly, both ends should have the same length and taper with the apex of the angle at the adjacent plane of contact of the legs (Fig. 33, b). CHECK QUESTIONS 1. Why and how are the surfaces of the marked workpieces prepared? 2. Why do marking marks need to be applied at one time? 3. How to find the center of a circle on a flat workpiece? 4. What is called the base for marking parts, and under what conditions is it chosen? 5. What kind of core is used to mark the marking marks, in what places and at what distance are the core recesses made? 6. What labor safety requirements must be observed when sharpening marking tools on a sharpening machine? CUTTING Occupational safety requirements. Before conducting felling training, the industrial training instructor is required to carefully inspect all tools and accessories. Tools in use must meet the following conditions: a) hammers must be firmly mounted on the handles and wedged in the hole with steel wedges; the working surface of the hammer should have a smooth, slightly convex surface without cracks or chips, and the handle should have an oval cross-section with a uniform thickening towards the end; the surface of the handle must be clean and smooth, without knots, cracks or chips; the length of the handle for hammers weighing 500-600 g should be 350-380 mm; b) chisels and crosspieces should not have cracks or chips; the ribs of the sides of the middle part should be rounded and smooth, the surface of the striking part should be smooth and slightly convex, the length of the chisel or cross-section should be such that its striking part is at a distance of 25 mm from the thumb. The sharpening angle of the chisel and crosspiece varies between 45-64)-70° depending on the hardness of the metal being processed. The cutting edge of the chisel should be a straight or slightly convex line with equal chamfer widths. During classes, the instructor should pay special attention to the installation of heavy parts in the vice, as they can easily break out of the vice and can cause bruises to the hands and feet of students. The instructor 22 must also ensure that the pieces of metal being cut fly off towards the protective mesh, and that the worker wears safety glasses. To protect your hands from damage (in the initial period of training), you should put a safety rubber washer on the chisel. Before starting work on sharpening machines, the instructor must check the student’s knowledge of the requirements for safe work on sharpening machines set out in Chapter. 2. Let's consider the general requirements for safe work with hand-held pneumatic tools. 1. It is prohibited: a) to work with a pneumatic tool without gloves; b) to hold a pneumatic tool by the hose or working tool, etc. work with it on a ladder; c) carry out repairs and partial disassembly of a pneumatic tool without disconnecting it from the air duct; d) insert and remove the working tool while the pneumatic tool is operating. 2. The hose must not have kinks, tears or abrasions. 3. Avoid straining, looping and twisting of the hose. 4. Connect a rubber hose to a pneumatic tool only when the air duct tap on the supply line is closed. 5. Before disconnecting the hose from the air tool, close the valve that supplies compressed air from the air line to the hose (compressed air escaping from the hose opening may cause the hose to be pulled out of your hands and cause injury). 6. It is necessary to check the strength of the fastening of all parts of the tool, the presence of lubricant in the bearings and rubbing parts. In addition to the general ones, there are additional occupational safety requirements. For example, when working with a pneumatic hammer: a) you must wear safety glasses; fence the cutting area with a metal mesh; b) when adjusting the number of blows, you should not try the hammer while supporting the hammer with your hands, it can fly out of the hammer and cause injury; c) air can be supplied to the pneumatic tool only after the hammer has been installed in the working position. Wrist blow with a hammer. When cutting metal, the quality of processing depends on the correct techniques for working with a percussion tool (hammer). The force of the blow is determined by the nature of the work performed and depends on the mass of the hammer, the length of the handle, the magnitude of the swing and the speed of movement of the hammer. At the workplace, the hammer should lie on the right side of the vice and be turned towards it with a round striker. The impact training device is placed on the left side of the vice with the clamping part facing the operator. The device is installed in the middle part of the jaws of the vice. The jaws are clamped only with the force of the hands, and not with the weight of the whole body. 2" Labor productivity and reduction of fatigue depend on maintaining the correct position of the feet and body of the worker. The height of the vice position must correspond to the height of the worker, and with the vertical position of the worker’s body and the horizontal position of the elbow part of the arm lying on the jaws of the vice, the angle between the elbow and shoulder part of the arm should be equal to 90°. When chopping, you should stand straight and steady, half-turned to the vice Rubber Steel pipe " Fig. 34. Position of the feet and body of the person working when chopping Fig. 35. Movement of the hand during a wrist blow and a device for striking (Fig. 34), and hold the hammer in the right hand at a distance of 15-30 mm from the end of the handle. The training device is held with the left hand at a distance of 30 mm from the striking part (Fig. 35). The wrist blow is carried out by moving only the hand without bending the elbow (Fig. 36, a). 36: Methods of holding a hammer when chopping: a “without unclenching the fingers; b -> with unclenching the fingers 24. There is a wrist blow, in which at the beginning of the swing, when moving the hand upward, the hammer handle is held with all fingers with a slight extension of three fingers (Fig. 36, b). When striking, squeeze all fingers, bending the hand forward, strike the head of the training device. The exercise involves training movements with a hammer during an elbow strike, the position of the body and holding the device with the left hand. the same as when performing a wrist shot. The head of the device is struck with a hammer using a complex movement of the right hand (Fig. 37). Rice. 37. Movement of the hand during localization. Fig. 38. Movement of the hand during a back blow When swinging the hammer upward, first the hand bends at the wrist, and then at the elbow. At the moment of completion of the swing, the little finger, ring and middle fingers slightly unclench. When striking, first squeeze the hammer handle with all fingers, then make a sharp movement of the elbow part of the hand away from you and, finally, straighten the wrist. Shoulder strike with a hammer. This blow is used when chopping when it is necessary to strike with great force. When applying shoulder blows, you should hold the training device with your left hand and apply well-aimed blows with a hammer to the striking part of the device. The movement of the right hand must be carried out according to the following complex pattern. When swinging, the hand is bent simultaneously at the wrist, elbow and shoulder joint with full coverage of the hammer handle with all fingers. At the moment of completion of the swing, the little finger, ring and middle fingers are unclenched (Fig. 38). When striking, the shoulder part of the arm is sharply lowered down, at the same time the arm is extended at the elbow, completing the blow by straightening the wrist. Hitting a chisel with a hammer. To do this job, the chisel must be dull. On the workbench it is placed on the left side of the vice with the cutting part facing the worker. 2" The cast iron tile is installed horizontally (6-10 mm above the level of the vice). The thrust recess for the chisel should be located at an angle of 45° to the sides of the plate (Fig. 39, a). The chisel should be held in the left hand by the middle part in such a way that the thumb rests on the index finger (Fig. 39, b). The distance from the hand to the striking part and the chisel is 20-25 mm. (The correct position of the legs and body was discussed earlier.) The chisel is installed against the stop on a cast iron plate at an angle of 45° to the axis of the vice jaws and at an angle of 30-35° to the horizontal. When applying wrist blows with a hammer to a chisel (Fig. 39), the student should look only at the working part of the chisel. To protect your left hand from possible bruises if you miss, put a rubber washer on the chisel. a) b) C) Fig. 39. Working with a chisel: o - position of the chisel on the tile; b “* - technique of holding a chisel; c - work procedure: Cutting sheet steel according to the level of the jaws of the vice. Training task 1 on cutting a large allowance on sheet metal in a vice is performed in the following sequence. 1. The marked workpiece is installed and clamped between the jaws of the vice so that the marking line is at the level of the jaws of the vice. 2. Take the chisel in the left hand, the hammer in the right and take the correct stance. 3. The chisel is placed to the edge of the workpiece so that the cutting edge lies on the surface of two jaws, and the middle of the cutting edge is in contact with the material to be cut at 2/3 of its length. The angle of inclination of the chisel to the surface being processed should be 30-35° (Fig. 40, a), and the angle of inclination of the chisel to the axis of the vice jaws should be 45° (Fig. 40, b). Such an installation of the chisel ensures the least fatigue for the worker and prevents damage to the surface of the jaw and the cutting part of the chisel. 4. Chopping is done only with a well-sharpened chisel. With the right hand, accurately and accurately strike the chisel with a hammer and, in the interval between blows, move the chisel along the workpiece. Particular attention should be focused on the cutting part of the chisel and the chips being cut, weakening the blows at the end of the cut until the metal is completely cut off at the first mark. With this cutting method, the cut layer is always twisted and is not used in the future. 26 After finishing cutting along the first notch, place the hammer and chisel on the workbench, unclench the vice, rearrange the workpiece with the second notch up at the level of the jaws and repeat the cutting. Excess metal for other risks should be cut down in the same way. Training task 2 on cutting material in a vice according to marked marks is carried out in the same sequence as cutting at the vice level, but using a different cutting method, with. in which the sheet material is not deformed. 1. Take a chisel and a hammer in your hands and take the correct stance. Rice. 40. Cutting down metal at the level of the jaws of the vice: a - installing the chisel at an angle to the horizontal; 6 - installation of the chisel at an angle to the axis of the jaw jaws Fig. 41. Cutting metal at the level of the jaws of the vice: a - installing the chisel at an angle to the forge; b - installation of the chisel at an angle to the axis of the jaws of the vice 2. The chisel is installed on the edge of the workpiece so that the edge of the cutting edge of the chisel is in full contact with the plane of the workpiece, forming an angle of inclination of the chisel to the horizon of 30-35 hours (Fig. 41, a), and the axis the chisel was perpendicular to the plane of the workpiece (Fig. 41, b). 3. With the right hand, apply weak blows with a hammer to the chisel, and with the left hand, in the interval between blows, move the chisel in the figure to 2/3 of the length of the cutting edge, performing a preliminary cut along the entire length of the marks. 4. Chopping continues with strong blows, moving the chisel in several passes (using elbow and shoulder blows). At the end of cutting, the impact force is weakened until one part of the metal is completely separated from the other. Sheet material 3-5 mm thick is cut in two steps. First, make a deep cut (at least half the thickness of the sheet) on one side of the workpiece, and then turn it over on the other side. side and cut it completely, combining the blows of the hammer with the movement of the chisel. Cutting steel above the level of the vice jaws. Let's consider the technique of cutting strip or thick sheet material at risks located above the level of the vice. 1. Risks that limit the amount of cutting are marked with marking tools. The cutting productivity, processing accuracy and roughness of the processed surface are affected by the thickness of the layer being cut (chips), therefore it is practically established that the thickness of the chips should not exceed 0.5-1 mm. After marking the marks, inclined marks (bevels) are applied on both sides of the workpiece, which are the starting plane at the initial moment of cutting. 2. The workpiece is clamped in a vice and the bevels are cut off using the previously learned technique (cutting at the level of the vice). 3. The workpiece is installed in the middle part between the jaws of the vice so that the mark is directed parallel to the jaws and located 4-8 mm above their level. With this technique Fig. 42. Installation of the chisel during felling - Special attention must be paid to the metal above the level of the jaws of the assemblies: be given to the reliability of fastening - at an angle to the horizon; b - along the axis of movement of the workpiece in the vice for the sides of the vice to prevent its displacement between the jaws. 4. Taking a chisel and a hammer in your hands, take the working position; The middle part of the cutting edge of the chisel is placed on the bevel edge (strictly along the first mark). The angle of inclination of the chisel to the surface being processed should be 30-35° (Fig. 42, a), and in relation to the axis of the vice jaws it should be located along the layer being cut down (Fig. 42, b). 5. When chopping metal, elbow strikes are applied. As the chips are cut, the left hand with the chisel will move along the edge of the workpiece. Usually, when chopping, you have to adjust the angle of inclination of the chisel to the horizontal plane. At a large angle of inclination, the cutting edge of the chisel will cut into the workpiece, removing thick chips, and at a small angle, it will tear off a layer of metal. The correct choice of the chisel angle will be confirmed by uniform chip thickness. At the end of the cutting, the impact force is weakened to avoid breaking the chisel and damaging your hands. The same techniques are used to cut down the following risks. The straightness of the cutting plane is checked with a ruler. £8 Cutting metal with a mounted blow. Chopping with a mounted impact is the most effective and is used for large workpieces, when it is impossible to use chopping in a vice. Training task 1 on cutting strip and round metal on an anvil (slab) is performed in the following sequence. 1. Marking tools (a scriber and a measuring ruler) are used to mark the marks along which the cutting will be carried out. 2. Strip or round metal is placed on a plate or anvil; The cutting edges of the chisel are set at the risk with the chisel in a vertical position; the metal is first cut by hitting a chisel with more harmful force than a hammer; with strong shoulder blows, cut the strip to half the thickness (Fig. 43), turn it over and cut it on the other side; set the location of the cut at the edge of the slab and, pressing with your hands, produce a break. Training task 2 on cutting blanks from sheet steel. 1. The chisel is sharpened so that the cutting edge is rounded. 2. The workpiece is marked according to Rns. 43. Cutting metal by blowing a template or by geometric construction, then parallel to the marked contour (at a distance of 1-2 mm from the first mark) a second mark is applied. 3. To cut out the workpiece, the chisel is installed obliquely along the second marking mark (Fig. 44.6). After checking the correct position on the mark, the chisel is placed in a vertical position (Fig. 44, b) and light blows are applied to it with a hammer, moving along the markings. In a similar way, preliminary cutting of the entire contour is carried out (Fig. 44, a). After preliminary scoring, you should continue cutting with strong shoulder blows on one side of the workpiece to a depth of more than half the thickness of the sheet. The number of passes depends on the thickness of the workpiece. When chopping with a mounted blow, you must use both hands, with your right hand, accurately and accurately apply strong blows with a hammer to the chisel, and with your left hand, move the chisel (in the interval between blows) along the preliminary cut. Each shift of the chisel along the workpiece should not exceed 2/3-% the length of its cutting edge. For final cutting, it is necessary to turn the workpiece over to the other side (according to noticeable cutting marks), set the cutting edge of the chisel so that it does not touch the plane of the slab. 29 4. The quality of cutting is checked visually, paying special attention to the amount of allowance left for. further processing, to ensure that there are no cuts or bends in the workpiece resulting from the cutting process. Cutting out straight grooves in the metal to a given depth is carried out in the following sequence: 1. All side surfaces of the cast iron tiles are painted with a chalk solution and dried, and marks are applied (distance). there should be no more than 10 mm between the grooves) Fig. 44. Cutting out workpieces with a mounted blow and installing a chisel: o - work procedure; b * - installation with a slope; c - vertical installation 2. In a vice, the tiles are placed in such a way that the mark, which determines the depth of the groove, is located at least 5 mm above the level of the vice jaws. The Kreuzmeisel should be held in the left hand by the middle part, loosely clasping it with all fingers so that the thumb rests on the index finger. The distance from the hand to the striking part of the crosspiece should be at least 20-25 mm (Fig. 45, a). 3. The cutting edge of the crossmeissel is installed obliquely at the edge of the tile in the direction of the marks and inclined chamfers are cut out at the corners of the tile at the locations of the grooves (Fig. 46). One of the main conditions in cutting grooves is to sharpen the crosspiece with undercut, which ensures clean edges of the grooves (see Fig. 45, b). 4. The cutting edge of the crossmeissel is placed on the chamfer plane (see Fig. 45, b), and, hitting the striking part of the crossmeisel with a hammer, a preliminary groove is cut along the marks to a depth of no more than 1 mm. For convenience, cutting should begin from the right groove. In subsequent passes, it is necessary to sequentially remove a layer of metal no more than 1 mm thick, leaving about 0.5 mm for finishing cutting.1 The remaining grooves are cut in a similar way. Then, applying lighter blows with a hammer to the kreitzmeisel, they perform finishing trimming (alignment) of all grooves. The straightness of the sides is checked with a ruler, the depth of the groove is checked with a measuring ruler. Rice. 45. Cutting out straight grooves with a crosspiece: “I’m spinning the holding of the crossmeisel; b “■ sharpening the crosspiece on the undercuts in *” method of work, cutting down a layer of metal from wide surfaces. If it is necessary to manually cut off a layer of metal from a surface, then a series of grooves are cut into it to the depth of the layer being removed, and then the resulting protrusions are cut off, and the width of the protrusions must correspond to the length of the cutting edge of the chisel. Cutting down the protrusions is carried out in the following sequence. 1. A cast iron tile with cut-out grooves is clamped in a vice so that the mark on the side edge is 5 mm higher than the level of the VICE jaws. ri^ 46. Cutting off the chamfers 2. For convenience, cutting off the protrusions is done on the right side of the tile. At the edge of the protrusion, set the middle part of the cutting edge of the chisel at an angle of 45° to the direction of the groove and, striking the chisel with a hammer, cut off the protrusion to the middle of the tile (Fig. 47). Using the same technique, cut off the remaining metal protrusions, then turn the tile 180° and cut off the protrusions on the opposite side, trying to prevent the metal from chipping at the edge of the tile. To avoid tearing out at the end of the cutting, the impact force should be reduced. 3. The entire plane is leveled with a chisel, which is struck lightly with a hammer, removing chips no more than 0.5 mm thick. 31 The plane should be relatively smooth and even. Cutting out curved grooves with crossmeisel. To lubricate rubbing surfaces in various machines and mechanisms, it is necessary to make special curved grooves (grooves) with cross-sections of various configurations. The operation of cutting out curved grooves with a cross-meissel requires greater accuracy and care compared to the operation of cutting out straight grooves and is performed in the following order. 1. The upper plane of the cast iron tile is painted with a solution of vitriol. Using marking tools (compasses and measuring rulers), the contours of the grooves are applied to the surface of the tile and punched. On the sides, where the grooves exit, a semicircular section is marked. 2. The tile is clamped in a vice so that the groove depth marks are higher than the level of Fig. 47. Cutting off a layer of metal from wide jaws and 4-8 mm, and one of the planes of the side sides (with the exit of the grooves) was facing the worker. In preparation for chopping, it is necessary to sharpen the crossmeisel correctly so that the cutting edge is rounded, sharp and matches the radius of the groove. 3. Lateral undercutting of the grooves is carried out by filing with a round file to form a bevel to the depth of the grooves at their Fig. 48. Chamfering and cutting out curved grooves of the exit and entrance (Fig. 48). The cutting edge of the crosspiece is placed on a bevel between the marks, light blows are applied with a hammer to the crossmeissel, directing it between the marks to create a trace of a groove up to 0.5 mm deep. This operation is performed first 32 Fig. 49. Reception of work with a pneumatic ru-* from one edge of the slab to the middle of the groove, and then counter from the other edge to the middle. The depth of subsequent passes is 1 mm, the preliminary allowance for finishing cutting is about 0.5 mm. Finish cutting is carried out at both ends, leveling out existing irregularities and giving the grooves the same depth and roughness. 4. Repeating the techniques for cutting the first groove, sequentially cut the second groove. - The quality of cutting grooves is determined by the roughness of the radius surface, and the width and depth of the grooves - by the radius template. Working with a manual pneumatic chipping hammer. To mechanize cutting, riveting and embossing, pneumatic chipping and riveting hammers are used. Cutting metal with a pneumatic hammer is performed in the following sequence. 1. Before starting to work with a pneumatic hammer, study the safety requirements, repeat the general techniques and methods of preparing a pneumatic tool. 2. The hole in the sleeve and the shank of the chisel are wiped clean; check the position of the bushing, which should be tightly seated in the hole; The chisel is installed in the bushing with a tight fit. 3. Lubricant is poured into the hammer body through a special hole, the trigger is pressed and through the open hole the lubricant is introduced into the internal working parts. 4. Put on gloves and safety glasses; take a working position; With your right hand you take the handle of the hammer, placing your thumb on the trigger, and with your left hand you hold the body of the hammer (Fig. 49). 5. The cutting edge of the chisel is installed at the cutting site; pull the trigger and cut off a layer of metal. When cutting, the chisel is placed at an angle of 30-35° to the surface being processed. Chopping is done only with a sharply sharpened chisel. When carrying a pneumatic hammer, do not allow tension, looping or twisting of the hose. After finishing cutting, turn off the pipeline tap and disconnect the pneumatic hammer from the air line, remove the working tool, clean the hammer from dust, dirt and wipe it clean; carefully wind up the hose. Sharpening the chisel crossmeisel. The quality of metal cutting depends on the serviceability and correct sharpening of the cutting tool. The sharpening angle is chosen depending on the type of metal being processed 2 ODvdod", £.,of the parts divided into the length of the workpiece, 1c, EL "L ^E so Fig. 64. An example of bending strip metal at an angle Fig. 65. at an angle of 90°; a - angle A * b - angle B of strip metal under Training task /, consisting of When bending strip metal in castings, perform it in the following sequence. Take allowance for bending of the part in two places (Fig. 64) equal to its thickness (2 mm). Then the length of the workpiece is L = 20 4- (80 - - 2) -f. 65 4- 2 = 165 mm (excluding processing allowance). If the workpiece needs to be cut off from the strip, take an additional allowance for further processing of the ends of 1 mm per side. Thus* the total length will be 167 mm. Then set aside the established size from the edge. The strip is laid on the plate and the workpiece is cut off with a mounted blow and, if necessary, straightened. The length of the flange of the first bend is measured on the workpiece [(20 4-1) mm] and the workpiece is then clamped in a vice between. mouthpieces so that the bend line coincides with the upper plane of the mouthpiece. With the blows of a hammer, one shelf of the square is bent (Fig. 65, c), due to which the bent end of the workpiece, tightly adjacent to the plane of the mouthpiece, creates an angle A. The workpiece is removed from the vice, a size of 80 - 2 = 78 mm is measured from the bent end and applied bending risks for corner B (see Fig. 64). After this, the second end of the workpiece is clamped in a vice and the second shelf of the square is bent with blows of a hammer (rio. 65, b). Rio. 66. Bending of strip metal on flat mandrels: a< эскиз скобы; б-г - этапа гибки Гибка с применением приспособлений. Учебное задание 1 заключается в гибке полосовой стали на плоских оправках (на примере изготовления прямоугольной скобы) я выполняется в следующем порядке. 1. Определяют длину заготовки (припуском на один изгиб 0,5 толщины полосы) (рис. 66, a) L = 18 4- 1 4- 15 4- 1 4- 20 4- 1 +■ 4- 15 4- 1 4- 18 = 90 мм. 2. Откладывают длину о дополнительным припуском на обработку торцов по 1 мм на сторону (90 4- 2). 3. Откладывают размер 35 мм (18 4- 1 4- 15 4- 1), нанося линию раски первого изгиба. 4. Размеченную заготовку зажимают в тисках между нагубниками на уровне риски и ударами молотка загибают один конец скобы (рис. 66, б). 5. Заготовку устанавливают в тисках с оправкой и ударами молотка загибают второй конец (рис. 66, в), размеры оправки должны соответствовать размерам скобы (20x15) мм. 6. Заготовку освобождают из тисков и вынимают оправку. На наружных плоскостях загнутых концов размечают высоту скобы на размер 15 мм. 7. Внутрь скобы вставляют другую оправку, зажимают <зкобу с оправкой в тисках и по рискам, расположенным на уровне плоскостей нагубников, загибают лапки скобы (рио. 66, г). 43 8. Скобу освобождают из тисков и вынимают оправку. Правильность гибки проверяют измерительной линейкой (линейные размеры и совпадение плоскостей лапок) и угольником (угол изгиба). Учебное задание 2 состоит в гибке полосовой стали (рамка для ножовки) на ребро с применением приспособления (рис. 67) и выполняется в следующей последовательности. 1. От стальной полосы отрезают заготовку по размеру чертежа с припуском б мм. 2. Ролики приспособления смазывают для облегчения изгиба полосы. Рйс 67. Гибка рамки для слесарной ножовки: в -" «кема приспособления: 6 - образец гибки; в - прием гибки 3. Рычаг отводят в верхнее положение / (рис. 67, в), заготовку вставляют в прямоугольное отверстие так, чтобы ее выступающий конец соответствовал заданному размеру (обычно этот размер отмеряют от наружной грани приспособления). Затем заготовку зажимают в приспособлении винтами. 4. Рычаг приспособления обхватывают двумя руками и с большим усилием отводят рычаг вниз (положение 2 рис. 67, в). Обкатывая роликами заготовку по радиусной сфере приспособления, получим изгиб полосы на ребро (рис. 67, б). 5. Правильность изгиба проверяют угольником. Учебное задание 3 заключается в гибке полосовой стали на круглых оправках (на примере изготовления цилиндрической втулки) и выполняется в следующей последовательности. 1. Сначала определяют длину заготовки, получая при сгибании полосы цилиндрическую втулку (длина заготовки соответствует длине средней окружности). Если внешний диаметр равен 20 мм, а внутренний 16 мм, то средний диаметр будет равен 18 мм. Тогда общая длина заготовки L - пГ> = 3.14-18 = 56.5 mm. 2. The workpiece with the mandrel is clamped in a vice so that half of the bent part is above the level of the jaws of the vice 44 3. Using a hammer, bend the end of the strip along the mandrel, achieving a tight fit of the strip to the surface of the mandrel (Fig. 68, a). 4. The workpiece with the mandrel is rearranged with the reverse side (Fig. 68, b), and then the workpiece is bent approximately half the circle with hammer blows. 5. Using a hammer, bend the second end of the strip along the mandrel (Fig. 68, c) until the two planes come into close contact at the joint. 6. The workpiece is released from the vice, the mandrel is removed and they begin to check the quality of bending by determining the diameter using a measuring ruler. Bending round metal using fixtures. Bending of a round steel bar on round mandrels (using the example of making an eyelet with a rod) is carried out in the following sequence. 1. Determine the length of the bend of the eye by the average diameter (Fig. 69, a), then measure from the end of the rod (mark) a distance equal to half the circumference of the ring. Rice. 69. Bending round metal on round mandrels Fig. 68. Bending of strip metal on round mandrels d) 2. The workpiece with the mandrel is clamped in a vice so that the outlined mark for the semicircle is at the level of the jaws of the vice. 3. Using a hammer, bend the half ring (Fig. 69, b). 4. The workpiece with the mandrel is rearranged with the reverse side and the second half-ring is bent with blows of a medium-force hammer (Fig. 69, c). 5. The eye with the mandrel is clamped in a vice and with hammer blows the rod is given the correct position in relation to the ring (Fig. 69, d). The bending quality is checked for the symmetry of the location of the ring in relation to the rod. Pipe bending. One of the main preparatory operations in the manufacture of pipelines is bending pipes at various angles, performed using special devices or on pipe bending machines. The training task consists of bending a steel pipe with a diameter of 1" in a cold state with filler. 1. And prepare two wooden plugs with a diameter equal to the internal diameter of the pipe and a length corresponding to four to five of its diameters. 2. The plug is inserted into one end of the pipe and driven in with a hammer to a depth of two to three diameters. 3. Sift fine dry river sand. Place the pipe in a vertical position (end with the plug down) and pour the sifted sand into it. Fig. 71. Method of bending steel pipes Fig. 72". We bend steel pipes manually using a manual pipe bending machine 4. The sand is compacted by tapping the surface of the pipe with a hammer or hitting the pipe against a gasket located on the floor. After compacting the sand, a wooden plug is hammered into the second end of the pipe (Fig. 70). 5. The bend area is marked with chalk. Put on mittens. 6. The bent pipe is inserted into the pipe clamp, between the corner recess of the base and the cracker with ledges, and by rotating the handle the pipe is clamped into. pressed. (When bending welded pipes, the seam must be placed on the outside, and not inside the bends, otherwise the pipe may separate along the seam.) 7. A piece of large bottom pipe is put on the end of the pipe being bent so that its end does not reach the bend mark slightly. then, grasp the pipe with both hands and, with great effort, move it in the direction of the bend (Fig. 71). To control the end of the bend, a wire template is placed on the center line of the pipe. “ 8. After bending is completed, the pipe is released from the clamp, the wooden plugs are knocked out and sand is poured out. Hot pipe bending is carried out in a similar sequence. Before bending, the beginning of the bend is marked on the pipe with chalk, the bend is heated in a forge or with a gas burner until it turns cherry-red; then the pipe is secured in a clamp and the pipe is bent at a given angle according to the template. Since this heats up a large area of the pipe, which can displace the bend location, the pipe should be cooled with water. Training task 2 consists of bending a steel pipe on a manual machine in a cold state without filler; it is performed in the following sequence. 1. The manual machine is prepared for bending by placing the handle in position A (Fig. 72). Rice. 73. Bending pipes made of non-ferrous metals: in a vice; b-c rollers in fixture 2. Mark the beginning of the bend on the pipe with chalk. 3. One end of the pipe is placed between the movable and stationary rollers and into the hole in the clamp so that the marking line on the pipe aligns with the mark marked on the surface of the stationary roller. 4. Take the handle with both hands and turn it clockwise to a given angle according to the template. If the force of the hands is not enough, then in order to increase the leverage of the application of force, a piece of pipe is put on the handle. The correctness of the bend is checked using a template or a part (bent pipe). Training task 3 consists of bending pipes made of non-ferrous metals and is performed in the following sequence. 1. Make a wooden plug and hammer it into one end of the pipe. 2. Melt the filler (rosin). The vessel must have a spout to drain the melted rosin into the pipe. 3. The pipe is installed vertically (with the plug down) and rosin is poured into it, leaving the pipe in this position until the rosin has completely hardened. 4. Pipes are bent in one of two ways: a) clamped in a vice between wooden jaws and bent by hand (Fig. 73, a); the bending angle is checked using a template or product; , t b) using a roller device (Fig. 73, b), when working with which one end of the pipe is inserted between the rollers into a stationary clamp. The lever handle is grasped with both hands and rotated, bending the pipe. 5. The pipe is released from the vice (device), heating it, starting from the open end, along its entire length; rosin is melted and poured into a vessel. CHECK QUESTIONS 1. How do you straighten round and sheet metal by hand? 2. How to straighten an edge-bent steel strip with a spiral bend? 3. How to straighten a curved angle steel strip using a manual screw press? 4. Tell us about the features of straightening hardened parts. 5. How long does the workpiece need to be taken to make a ring with a diameter of 200 mm from a round steel bar with a diameter of 8 mm? 6. How do pipes dry in a cold (hot) state? CUTTING Occupational safety requirements. When starting to conduct metal cutting classes, the industrial training instructor must carefully inspect all tools and devices. Hand hacksaws in use should not be bent, the blade in the hacksaw machine should be in the same plane and have sufficient tension. The pins for fastening the blade should not have sharp or protruding parts. Wooden handles should be made of hardwood, they should not have cracks or chips. The surface of the handle should be clean and smooth; to prevent splitting, a metal ring should be placed on the handle. The handle should be firmly and securely placed on the tail part of the hacksaw. The tail part should fit into the handle at a/s - %. of their length. Hand scissors for cutting metal should be selected according to the nature of the work being performed (straight, curved, right, left). Scissors must be well sharpened and cut without burrs, i.e., do not crush the metal being cut. The industrial training instructor should pay attention to the installation of round and heavy parts in the vice, as loose parts can easily break out of the vice and cause injury. When cutting with a hacksaw, the blade must be taut and firmly secured. Loosely tensioned and poorly secured blades can break during work and injure the worker. When working with manual lever shears, you should pay attention to the correct feeding of the material (perpendicular to the knives) and not allow it to jam between the knives. When cutting metal with scissors, you should protect your hands from injury from the cutting edges of the scissors and burrs on the metal and monitor the position of the fingers of your left hand supporting the sheet from below. 1. When working with hand-held electrified tools, it is prohibited to: a) perform work with a faulty power tool (with a faulty power cable and plug connection); b) carry out partial disassembly and repair of power tools; c) work with electrified tools in damp rooms and outdoors during rain, allow moisture to get inside the power tool, since the housing may be energized; d) hold an electrified tool connected to the network by the electrical cord, by the cutting tool, press it against the body, place it on your knees; e) leave the power tool connected to the network without supervision during a temporary interruption in work or power outage; f) move from one work area to another with the electric motor turned on; g) carry out processing of materials that produce rebound chips without safety glasses; h) allow persons to work with electrified tools who have not undergone proper training and who have not become familiar with the requirements of safe work; i) for persons not authorized to do so, to correct or replace fuses in the electrical network, disassemble the electric motor and switch of an electrified tool. 2. Work with an electrified tool is only permitted with a grounded body of the tool, wearing rubber gloves and galoshes, or standing on an insulated surface (rubber mat, dry wooden shield). Grounding is carried out with a special wire, connected at one end to the body of the power tool and the other to the ground loop. Without the use of protective equipment, you can perform work with high-frequency electrified tools, as well as under normal frequency current at voltages up to 36 V. 3. Immediately stop the power tool if it “sticks” in operation, the slightest malfunction or breakage of the cutting tool and inform the industrial training instructor or foreman. Before you start working with an electrified tool, you must do the following. 1. Check whether the screws and nuts securing all components and individual parts are tightened sufficiently. 2. Make sure that the mains voltage corresponds to the voltage of the power tool indicated on the label. The power tool cannot be connected to a network with a voltage higher than that indicated on the plate. 3. Carefully check the insulation condition of the current-carrying cable and reliably protect it from mechanical damage by hanging it. 49 4. Check the presence and serviceability of grounding of electrical tools; ment to the housing and grounding device. 5. Connect the current-carrying cable to the network and, by turning on the switch, let the power tool idle for 0.5-1 min and check: a) the failure-free operation of the switch; * b) the operation of brushes on commutator electric motors, where during normal operation very weak sparking should be observed under the brushes. When starting training work on a powered hacksaw machine, the industrial training instructor is obliged to: before starting work, carefully inspect and check the serviceability of the protective devices of the rotating parts, belt drives and the reliability of their fastening; starting devices and distribution devices (switches, magnetic starters, push-button stations and other electrical distribution devices), which must have protective casings that prevent contact of the worker with terminals, contacts and other live parts, as well as protective grounding. The frame of the hacksaw machine, 1 electric motor housing, casings of starting and distribution devices must have reliable grounding through a bolted or welded connection. While the hacksaw machine is operating, do not clean, wipe ■■ or lubricate moving and rotating parts; move from step to step with the engine running, blow off sawdust or remove it by hand (to avoid clogging your eyes or injuring your hands), lean on the machine and place tools, products and other objects on it. When working on a hacksaw machine, students are prohibited from repairing any equipment. If any malfunctions are detected, you should stop working immediately. The service life, productivity and accuracy of the machine depend on careful and careful maintenance. Before starting work, it is necessary to carefully inspect the machine, check its serviceability and, if necessary, lubricate it. While working, the workplace should be kept in order and not cluttered with unnecessary tools and parts. It is prohibited to leave a working machine unattended; When leaving, even for a short time, the machine's electric motor should be turned off. After finishing the work, you need to remove the tool and clean the machine from chips and dirt with a hair brush or cotton rag. After this, you need to use a hand oiler and a swab to lubricate the working surfaces of the machine with a thin layer of machine oil. Working with a hand hacksaw. By performing this exercise, students acquire skills in working with a hand hacksaw. The exercise is performed in the following sequence. 1. The blade is inspected, paying attention to the absence of cracks, bends, and also the spread of teeth. "SO 2. Check the serviceability of the frame (body) of the hacksaw; tight fit of the handle, free rotation of the wing nut, movement of the sliding part and tension pin, presence of pins. 3. Set the sliding part of the hacksaw to the size of the blade, leaving the tension pin extended by 10-\ 2 mm. 4. Place the blade in the slots of the heads so that the teeth are directed away from the handle (Fig. 74). In this case, insert the end of the blade into the stationary head first until the holes coincide and fix the position with a pin. Then insert the second end of the blade into the head. the slot of the movable pin and secure it with a pin. 5. Tension the blade, screw in the wing nut without much effort, without resorting to pliers, a vice or other tools. When tensioning the blade, due to the danger of tearing it, you should keep the hacksaw at some distance from the linden. When working tightly (with slight misalignment) or weak (with increased pressure), the tension of the blade creates a bend during cutting and causes a break. First, a wooden block is cut using a hand hacksaw. Before clamping a wooden block in a vice, marks are applied to it on both sides to determine the location of the cut. The block is shifted to the left side so that the mark is located at a distance of no more than 30 mm from the edge of the vice jaws. Rice. 74. Direction of the teeth of the hacksaw blade<У 8) Рис. 75. Расположение рук пра работе ножовкой Стоять у тисков при резке ножовкой следует прямо, свободно и устойчиво, вполоборота по отношению к губкам тисков. Левую (опорную) ногу необходимо выставить немного вперед. Правильное держание ручной слесарной ножовки инструктор демонстрирует в три приема: I) ножовку берут в нравую руку так, чтобы ручка упиралась в ладонь (рис. 75, а); 2) ручку охватывают четырьмя пальцами, накладывая большой палец на ручку сверху (рис. 75, 67; 3) пальцами левой руки берут передний угольник ножовки, барашек и натяжной болт (рис. 75, <ф. Полотно ножовки устанавливают на широкую плоскость деревянного бруска, создавая в начале резания небольшой наклон перед» 51 ней части ножовки вниз. Для получения точного направления резания по разметке необходимо у риски поставить ноготь большого пальца левой руки, плотно прижать к нему полотно ножовки (рис. 76, а), а правой рукой осуществлять резание (рис. 76, б). Продолжая резание, режущую кромку полотна постепенно переводят в горизонтальное положение (рис. 76, в). Движения при работе ножовкой должны быть плавными, без рывков и с таким размахом, чтобы в резании участвовали все зубья полотна. Темп движений при резании ножовкой должен составлять 30-60 ходов в минуту. Заканчивая резание, следует ослабить нажим на ножовку, уменьшить темп движений, чтобы избежать поломки полотна и ранения рук. После окончания работы ножовку, повернутую полотном к тискам, кладут на верстак с правой стороны тисков. Рис. 76. Работа ручной слесарной ножовкой: а - установка ножовочного полотна на риску; 6 - прием работы в иачале резаиия; в «в прием работы в процессе резаиия Резка металла ручной слесарной ножовкой без поворота полотна. Выполняя это упражнение, обучающиеся овладевают приемами резания металлических заготовок различных профилей слесарной ножовкой. Для резания металлических прутков круглого сечения места резания размечают чертилкой. Пруток зажимают в тисках горизонтально, выдвинув отрезаемый конец в левую сторону от губок тисков настолько, чтобы при работе ножовкой ее головка не задевала боковую поверхность тисков. Если плоскость резания слишком удалена от губок тисков, пруток при резке будет дрожать, затрудняя резаиие. Пруток необходимо закреплять в тисках надежно. На заготовке (по риске) делают небольшой пропил трехгранным напильником, чтобы ножовочное полотно в начале резания не скользило по поверхности прутка. Затем берут ножовку, принимают рабочее положение, смазывают кисточкой полотно вареным маслом, вводят режущую кромку ножовочного полотна в пропил и приступают к резанию (рис. 77, а). В начале резки нажим на ножовочное полотно должен быть меньше, а по мере приближения полотна к центру прутка нажим усиливают. Во время резки ножовочное полотно иногда «уводит» в сторону, это создает косую прорезь (из-за слабого натяжения полотна или неправильного положения ножовки и ее направления). Если полотно «увело» в сторону, необходимо повернуть пруток и начать резание g противоположной стороны напротив прореза. В конце резки надо ослабить нажим на ножовку и уменьшить темп движения. 52 При резании металлического прутка квадратного сечения сначала размечают место резания, для чего отмеряют измерительной линейкой длину заготовки, нанося риски чертилкой. После этого, используя угольник с широким основанием, проводят риски на верхней и двух боковых сторонах квадрата. Далее пруток зажимают в тисках так, чтобы риска была расположена сверху. Для сохранности зубьев полотна резание начинают с заднего ребра детали, наклонив ножовку от себя до образования начала пропила при слабом нажиме (рис. 77, б). Наклон постепенно уменьшают до тех пор, пока пропил не дойдет до передней кромки и ножовочное полотно не примет горизонтального положения. В таком положении усиливают нажим на ножовку, продолжая резание прутка г) й) Рис. 77. Положение ножовочного полотна при начальном резаиии заготовок различных профилей: о - круглого; б - квадратного; в - прямоугольного; г » трубы; 6 ■» углового до конца с использованием всей длины ножовочного полотна и все время контролируя положение полотна и его направление по отношению к риске. В конце резания нажим ослабляют. Резание полосового металла (рис. 77, в), как правило, следует выполнять по узкой стороне полосы при условии, что резание производят не менее трех зубьев ножовочного полотна. Чем меньше зубьев одновременно участвуют в работе, тем меньший нажим на ножовочное полотно. Резку заготовок толщиной менее шага зубьев полотна следует осуществлять ножовкой в вертикальном положении, со слабым нажимом на инструмент. Работать ножовкой в этом случае надо медленно с использованием всей длины ножовочного полотна. При резании труб места резания размечают с помощью шаблона. Шаблон изготовляют из тонкой жести, изогнутой по окружности трубы. Измерительной линейкой от конца трубы отмечают длину отрезка. Кромку шаблона подводят к метке, наносят чертилкой риску по всей окружности трубы. Для резания трубу зажимают в тисках горизонтально. Чтобы избежать смятия трубы, ее зажимают в прокладках (рис. 77, е) Для резания выбирают полотно с мелкими зубьями (шаг зубьев 1 мм), трехгранным напильником по риске делают пропил и приступают к резанию. По мере углубления ножовочного полотна в стенку трубы ножовку немного наклоняют к себе. Прорезав трубу на толщину 53 стенки, вынимают ножовку, поворачивают трубу от себя на 45-60° и продолжают резание, сочетая поворот трубы с резанием по всей длине окружности трубы. Темп движения при резании труб должен составлять 35-45 ходов в минуту при малом нажиме на ножовку. В конце резания нажим на ножовку необходимо ослабить. Перед резанием уголка его размечают па плоскостях полок. Полку уголка надо устанавливать в тисках (рис. 77, д). Уголок необходимо резать по узкой грани полки, там, где требуется меньшая сила резания. Поэтому резание будет производиться значительно легче. Прорезав первую полку до внутренней плоскости второй полки, уголок устанавливают в положение резания первой полки, продолжая резание до конца. В конце резания необходимо ослабить нажим на ножовку. Правильность среза проверяют линейкой, а угол 90° - угольником. Резка металла ручной слесарной ножовкой с поворотом полотна. Выполняя это упражнение, обучающиеся должны овладеть приемами резания по- на глубину, превышающую ши- повернутым на 90°. Рис. 78. Приемы резания металла ручной слесарной ножовкой с поворотом ножовочного полотна лосового или листового металла рину рамки ножовки с полотном, Упражнение выполняется в следующей последовательности. 1. Разметку выполняют обычным способом. 2. Ножовку готовят к работе, причем проверяют качество полотна и его пригодность для работы. 3. Полотно в боковые прорези головок необходимо установить перпендикулярно к плоскости ножовки (зубья направлены от ручки); затем следует заложить в отверстие штифты и натянуть полотно. 4. Заготовку установить и зажать в тисках с боковой стороны, выдвинув отрезаемый коиец таким образом, чтобы при вертикальном резании головка ножовки не задевала боковой поверхности тисков н не мешала движению рук. Кроме того, заготовка должна незначительно возвышаться над уровнем губок тисков, иначе во время резки заготовка будет вибрировать. При резании необходимо следить за направлением полотна, поддерживая плоскость ножовки в горизонтальном „положении. Движение ножовкой следует выполнять плавно, без рывков, избегая перекоса полотна, так как это может привести к его уводу или поломке. По мере резания металла заготовку нужно переставлять выше для продолжения резания (рис. 78), уменьшая темп движения я силу нажатия на ножовку в конце резання. Размер отрезанной заготовки проверяют по размеченным рискам. Резка труб труборезом. Для резания труб кроме ручной слесарной ножовки используют специальный инструмент - труборез, 54 у которого режущими частями являются оетрые стальные диски- ролики. Для выполнения этого упражнения рабочее место должно быть снабжено специальным трубным прижимом. Трубу зажимают в прижиме вращением рукоятки с винтом между угловой выемкой основания и сухарем с уступами. Прежде чем приступить к работе труборезом, следует убедиться в его исправности и проверить: а) остроту режущих, лезвнй роликов; б) посадку роликов на осях (не должно быть, качания);, в) правильности установки роликов в одной плоскости. На конец зажатой трубы в прижиме надевают труборез и, вращая рукоятку трубореза вокруг своей оси, доводят подвижный ролик трубореза до его соприкосновения со стенкой трубы. Далее делают один оборот труборезом вокруг трубы; при этом ролики, легко врезаясь в- металл, оставляют след в виде риски. Если риска не раздвоенная и замкнутая, ролики установлены правильно. Приемы резания (рис. 79) заключаются в следующем. Рукоятку установленного на трубе трубореза поворачивают на V4 оборота, прижимая подвижный ролик к поверхности трубы так, чтобы линии разметки совпали с острыми гранями роликов. Место среза смазывают вареным маслом для охлаждения в уменьшения трения режущих кромок роликов. В результате вращения ручки трубореза на окружности трубы получится прорезанная линия. Рукоятку поворачивают еще на 1/* оборота- и делают один оборот труборезом вокруг трубы. Перемещая подвижньш ролик, вращают труборез вокруг трубы до тех пор, пока ее стенки не будут полностью прорезаны. Качество резки проверяют линейкой (длину отрезанных труб) и угольником (положение среза относительно наружта» стенки трубы). Резка проволоки. Подготовка провелоки к резке заключается в правке, которая осуществляется перетягиванием провшянн вокруг круглой оправки, зажатой в тисках. При этом- необходимо» соблюдать меры предосторожности, так как при трении проволока-ешшю нагревается и может вызвать ожоги; поэтому на рукк следует; надевать рукавицы. Перед резкой берут острогубцы в правую руку (рис., 8ЭД*. При этом, сжимая ручки, приближают друг к другу режущие кромки;, а нажимая на рукоятки мизиицем; после раарезан»» разводам ручки, В начале упражнения выполняют несколько движений кистью руки так, чтобы режущие кромки острогубцев раскрывались и за- Рис. 79. Резка труб труборезом 55 крывались. Правильность подгонки и остроту режущих кромок проверяют, разрезая тонкие бумажные листы. При резке проволоки острогубцы раскрывают на размер, превышающий диаметр проволоки, помещают проволоку между лезвиями так, чтобы они располагались перпендикулярно, и выполняют резание на заданные размеры. Кроме ручных кусачек, для резки проволоки применяют очень п
Ministry of Education and Science of the Samara Region
State budgetary educational institution
secondary vocational education
"Zhigulevsky State College"
Guidelines
for practical work
by discipline: Plumbing
for students I course
profession: 190629.08 Construction machine repairman
2015
APPROVED
Subject (cycle)
commission
technological profile
Protocol No. ____________
from “___” ______________ 201_
Chairman
G.S. Soldatenkova
Compiled in accordance with the requirements of the Federal State Standard for NPO by profession 190629.08 Construction machine repairman
Deputy Director for
educational work
S.Yu. Sorokina
“___” ______________ 201_
APPROVED
at the NMC meeting
Protocol No. ____
from ___________ 201__
Contains a description of all practical work performed by studentsIcourse when studying the discipline"Plumbing".
General requirements for performing all practical work and recommended literature are given in the introductory part of these instructions.
Compiled by:
Moshkina Elena Aleksandrovna – teacher of special education
disciplines of GBOU SPO "ZhGK"
Reviewers:
Soldatenkova Galina Sergeevna – teacher of special education
disciplines of GBOU SPO "ZhGK"
Content
Introduction
General instructions for performing practical work
The procedure for performing practical work and submitting a report
Safety rules and basic labor protection requirements when performing practical work
Practical work No. 1 “Measurements with calipers ShTs-1, ShTs-2”
Practical work No. 2 “Measurements with various types of micrometers”
Practical work No. 3« Measurements with templates, probes and protractors»
Practical work No. 4 “Measurements on an indicator stand, an indicator bore gauge and a depth gauge”
Evaluation criteria
INTRODUCTION
Practical exercises are an integral part of the discipline “Plumbing”.
This collection of descriptions of practical work contains topics, assignments and methodological recommendations for the student’s independent preparation for performing practical work, consolidating the material covered and testing knowledge.
The purpose of the collection is to determine the content, form and order of practical exercises.
In the process of preparing for practical classes, the student must review the material covered on the topic of the lecture and study the recommended additional scientific, technical and methodological literature.
The collection contains the thematic title of practical works, according to the thematic plan of the curriculum of the theoretical course. For each practical lesson, the purpose and objectives of the work, the order of implementation and the reporting form are outlined. At the end of each topic there are test questions to consolidate the acquired knowledge and skills.
At the end of the collection there is a bibliographic list of recommended literature.
GENERAL INSTRUCTIONS FOR IMPLEMENTATION
PRACTICAL WORK
Practical work is carried out after studying the theoretical material of the relevant topics.
Before starting the task, carefully and thoughtfully read this manual to be sure to understand the essence of the work.
Each practical work consists of the following stages:
independent training of students;
teacher checking students’ readiness to perform practical work;
performing practical work;
organizational and technical maintenance of the workplace, preparation of reports and protection of work results.
EXECUTION ORDER
PRACTICAL WORK AND REPORT SUBMISSION
The topic and order of practical work are determined by the course program and communicated by the teacher at the first lesson of the group.
Practical work is carried out in accordance with the training schedule. Students' work at the workplace is carried out in accordance with the guidelines for each practical work. The student must be prepared to perform the next practical work, having studied the necessary material in educational and teaching aids.
Reports are prepared for all practical work. The report on practical work is compiled by each student independently.
All reports are completed in one specially designated notebook. The report is completed during the practical lesson and, if necessary, completed through independent work. The completed report is presented to the next lesson.
At the beginning of each report, the topic of the work is indicated, the purpose and summary are given.
The overall credit for practical work is awarded to the student after he has completed all the work, prepared and defended the reports. The form of the test is an interview on all topics of practical classes.
SAFETY RULES AND BASIC OCCUPATIONAL HEALTH REQUIREMENTS WHEN PERFORMING PRACTICAL WORK
Before starting practical work, students must familiarize themselves with these rules. Each student who has completed the safety briefing must sign in the journal; students who have not completed the instruction and have not signed in the journal are not allowed to perform practical work.
Students are prohibited from:
remove parts, instruments from the laboratory or bring in foreign objects, smoke, make noise;
during classes, walk unnecessarily around the laboratory or approach other workstations, unauthorized disassemble or operate sections, models or other equipment, if this is not provided for by the practical work being performed;
lean on posters or place parts on them, write on tables, dirty their surface, leave paper and garbage;
perform actions with devices and other equipment that are contrary to safety regulations.
PRACTICAL WORK No. 1
Topic: “Measurements with calipers ShTs-1, ShTs-2”
Purpose of the work : study devices, the purpose of calipers, their preparation for measurements and methods of measuring and reading readings.
Work order
Exercise 1. Measurement with a ShTs-1 caliper
Familiarize yourself with the design of the caliper:
study all parts and their purpose (Fig. 1);
master the design of a vernier caliper (Fig. 2): the vernier length is 19 mm and is divided into 10 equal parts. One division of the vernier is equal to 19:10 = 1.9 mm, which is 0.1 mm less than a whole number of millimeters.
Rice. 1. Vernier caliper:
1 – rod; 2,7 – sponges; 3 – movable frame; 4 – clamp; 5 – vernier scale; 6 – depth gauge ruler
Rice. 2. Vernier
Prepare the caliper for use:
check the completeness of the tool;
rinse the instrument in aviation gasoline, wipe it dry with a soft linen cloth, especially wipe the measuring surfaces thoroughly.
Carry out an external inspection:
the jaws and the end of the rod must be in perfect order;
the measuring surfaces should not have signs of corrosion, nicks, scratches, blunt sharp ends of jaws or other defects that affect the accuracy of the measurement;
the strokes and numbers of the scales must be clear and even;
check the interaction of individual parts of the caliper, the smooth movement of the frame 3 , parallelism of jaws 2 And 7 , is there any skew or tight movement of the frame slider?
Check the zero position of the caliper:
bring the caliper jaw into contact (Fig. 3, A). The jaws must be parallel along their entire length. There should be no gap at the edges of the jaws. The zero line of the vernier must coincide with the zero line of the main scale;
Rice. 3. Checking the zero position of the caliper
the size of the gap between the measuring surfaces of the reduced calipers is estimated in daylight “by eye” (Fig. 3, b). If there is no clearance between the jaws for external measurements or with a small clearance (no more than 6 mm), the zero strokes of the vernier must coincide with the initial stroke of the main scale (Fig. 3, A);
if the instrument is not adjusted, then an appropriate correction must be made to the actual reading of the instrument, equal to the initial error, but with the opposite sign;
in case of a large discrepancy between the zero lines, it is necessary to unscrew the vernier screws, move the vernier plate until the lines coincide and secure it with the screws.
Measurement techniques:
take the part in your left hand, which should be behind the jaws and grab the part not far from the jaws (Fig. 4 , A). The right hand should hold the rod, while the thumb of this hand should move the frame until it comes into contact with the surface being tested, avoiding distortion of the jaws and achieving normal measuring force;
Rice. 4. Taking measurements with a ShTs-1 caliper
Fasten the frame with the thumb and forefinger of your right hand, holding the bar with the remaining fingers of this hand. The left hand should hold the sponge of the barbell (Fig. 4, b).
Reading the readings of the ShTs-1 caliper:
When reading the readings, hold the caliper directly in front of your eyes (Fig. 5, A). If you look at the readings from the side (Fig. 5, b), this will lead to distortion and therefore incorrect measurement results. To prevent distortion, the surface on which the vernier scale is applied has a bevel in order to bring the vernier scale closer to the main scale on the rod;
an integer number of millimeters is counted on the rod scale from left to right with the zero stroke of the vernier.
Fractional values (the number of tenths) are determined by multiplying the reading value (0.1 mm) by the serial number of the vernier stroke, not counting the zero, which coincides with the rod stroke.
Rice. 5.Reading the caliper readings
EXAMPLE. The zero line coincided with the 39th division on the bar, and the vernier at zero pressure showed the 7th division. The measurement result will be equal to: 39+0.1x7 = 39.7 mm.
Exercise 2. Measurement with a ShTs-II caliper
Familiarize yourself with the design of the ShTs-II caliper (Fig. 6, A).
Rice. 6. Vernier caliper ShTs- II:
– fixed measuring jaw, 2 – movable measuring jaw, 3 – movable frame, 4 – frame clamp, 5 – micrometric feed frame, 6 – microfeed frame clamp, 7 – rod with millimeter graduations, 8 – microfeed screw, 9 – frame feed nut, 10 – vernier
Study the structure of the vernier: it has a length of 39 mm, divided into 20 parts. One division of the vernier is 39:20 = 1.95 mm (Fig. 6, b), this is 0.05 mm less than a whole number.
Complete the tasks (see exercise 1, paragraphs 2 and 3).
Check the interaction of individual parts of the caliper:
smooth movement of the frame, parallelism of the jaws, is there any skew, backlash in the micrometric pair, tight movement of the frame slider, weakening and displacement of the spring located under the locking screw;
is there any wear on the working surfaces of the scale of the ruler and frame, causing distortion of the measuring surfaces of the jaws, inaccuracy of strokes on the scale and vernier.
Check zero position:
check the alignment of the zero stroke of the vernier 10 with zero division (stroke) of the rod 7 . For rough measurements frame 3 move along the rod until the jaws fit snugly. To accurately install the caliper, use micrometric feed 8 , 9 ;
if there is no gap between the jaws for external measurements or with a large gap (no more than 3 µm), the zero strokes of the rod and vernier with the jaws shifted must coincide. The position of the caliper scale and the vernier of the ShTs-II caliper with a reading value of 0.05 mm is shown in Fig. 7.
Rice. 7. Reading the readings of the ShTs-caliper II
Methods of measuring with a ShTs-II caliper:
set approximately the controlled size (for external measurements, Fig. 8, A slightly more, and with internal rice. 8, b slightly smaller than the controlled size). Attach the micrometer feed frame 2 ;
take the caliper with your right hand and support the rod sponge or part (if small in size) with your left hand;
with your right hand, securing the engine 2 using microfeed nut 3 , move the frame smoothly 1 so that the jaws come into contact with the surface being tested, secure the frame, avoiding distortion and achieving normal force;
Rice. 8. Methods of measuring with a ShTs-caliper II
install the caliper so that the part - the measurement line is not skewed, but is perpendicular to the axis of the part.
Incorrect installation of the caliper leads to an overestimation of the reading (Fig. 9 - external measurements; Fig. 10 - internal measurements).
Rice. 9. Installation of calipers Fig. 10. Installing a caliper
when measuring external surfaces when measuring internal surfaces
Reading the readings of the ShTs-II caliper:
hold the caliper directly in front of your eyes (Fig. 5);
count an integer number of millimeters from left to right with the zero stroke of the vernier;
find the vernier stroke that matches the bar scale stroke. To the figure closest to the left, indicating hundredths of a millimeter, add the results of multiplying the reading value by the serial number of the short vernier stroke that coincides with the bar stroke, counting it from the long digitized stroke. Examples are shown in Fig. 11, a, b;
Rice. 11. Examples of reference during measurements:
a, b– external surfaces, V– internal
for internal measurements (Fig. 11, c), the thickness of the jaws (10 mm) indicated on them is added to the readings of the caliper.
In Figures 12,13,14, find the size on the caliper scales.
Answer:
Answer:
Answer:
Security questions:
Name the universal measuring instruments for dimensional control used in plumbing.
What is a universal caliper, what is it intended for and what elements does it consist of?
What is vernier?
What determines the accuracy of size measurements?
PRACTICAL WORK No. 2
Topic: “Measurements with various types of micrometers”
Purpose of the work: study the design, overlay and measuring techniques with micrometers.
Micrometer types:
MK– smooth micrometers for measuring the external dimensions of products;
ML– sheet micrometers with a dial for measuring the thickness of sheets and tapes;
MT– pipe micrometers for measuring pipe wall thickness;
MOH– gear micrometers for measuring gears.
Micrometers type MK are designed for measuring external dimensions. They are available with measurement limits: 0-25; 25-50, etc. every 25 mm, and then from 300-400; 400-500; 500-600 mm.
Micrometers with an upper measurement limit of 50 mm or more are supplied with installation standards 8 (Fig. 12). Micrometers with an upper measurement limit of more than 300 mm have movable heels, providing the ability to measure any size within a given micrometer.
Work order
Exercise 1. Measurement with an MK micrometer
Study the design of the MK micrometer (Fig. 12, A).
Rice. 12. Micrometer MK:
A- device, b– micrometric screw, V- drum; 1 - bracket, 2 – heel, 3 – screw, 4 – stopper, 5 – stem, 6 - drum, 7 – ratchet, 8 – installation measure
Familiarize yourself with the structure and purpose of the vernier (Fig. 12, V):
on the outer surface of the stem 5 a longitudinal line is drawn, below which millimeter divisions are applied;
micrometer screw 3 , the pitch of which is 0.5 mm, is connected to the drum 6 . The conical part of the drum is divided around the circumference into 50 equal parts (vernier in Fig. 12, V);
per revolution micrometer screw 3 moves along the axis by a thread pitch (Fig. 12, b). When turned by one division, the micrometer screw 3 , connected to drum 6, moves along the axis by 1/50 steps, i.e. 0.5:50=0.01 mm, which is the micrometer division price.
Setting the zero position of the vernier (Fig. 13):
check the zero position of the micrometer before measuring: a correctly adjusted micrometer has a heel 2 and screw 3 (see Fig. 12) must be in contact with the measuring surfaces of the installation standard 8 or directly among themselves (with a diameter measurement range of 0 - 25 mm), and the zero stroke of the drum should coincide with the longitudinal stroke of the stem, while the bevel of the drum should open the zero stroke of the stem (Fig. 13, A);
Rice. 13. Setting the zero position of the MK micrometer
If the strokes do not match, the micrometer should be adjusted:
lock the micrometer screw 3 with the measuring planes flattened;
loosen the cap 2 , connecting the drum with a microscopic screw, holding the belt with the left hand 1 (Fig. 13, b);
release the drum from the clutch with the screw and turn it until the zero line on the bevel of the drum coincides with the longitudinal line of the stem (Fig. 13, A);
secure the drum to the screw using the cap.
Measurement with MK micrometer:
wipe the measuring surfaces with a soft cloth or paper (Fig. 14, a – b);
set the micrometer to a size slightly larger than the one being tested;
take a micrometer (Fig. 14, V) left hand behind the bracket 1 (in the middle), and the part being measured 3 place between the heel 2 and the end of the micrometer screw 4 ;
With the fingers of your right hand, smoothly rotate the ratchet 5 , lightly press with the end of the micrometer screw 4 detail 3 to the heel 2 until it touches the surface of the part being tested, until the ratchet 5 will not start turning and clicking;
when measuring a part, the measurement line must be perpendicular to the generatrix and pass through the center (Fig. 14, G).
Rice. 14. Measurements with an MK micrometer:
a, b– wiping working parts, V– method of installing a micrometer, G– measurement line
Micrometer reading:
When reading readings, keep the micrometer directly in front of your eyes (Fig. 15, A);
a whole number of millimeters is counted on the lower scale, half a millimeter is counted on the upper scale of the stem, and hundredths of a millimeter are counted according to the divisions of the drum scale, according to the stroke that coincides with the longitudinal mark on the sleeve;
in Fig. 15, b examples of readings are given.
Rice. 15. Working with a micrometer:
A- reading readings, b– examples of reference
Security questions:
How should you handle measuring instruments?
What are the tools and instruments for precise measurements?
Why should the accuracy of a measuring tool be higher than the manufacturing accuracy of the part being checked by this tool?
PRACTICAL WORK No. 3
Topic: “Measurements with templates, probes and protractors”
Purpose of the work: study the design of templates, chisels and goniometer tools, measuring techniques with goniometers and the rules for taking readings.
Sample(German Schablone, from French echantillon - sample) in technology, a device or tool for checking the correct shape of a number of finished products; a sample from which homogeneous products are manufactured.
Template types:
Radius pattern- a tool for monitoring the profile radii of curvature of convex and concave surfaces of machine parts and other products. It is a steel plate 0.5-1 mm thick with a concave or convex rounding at the end (Fig. 16). Curvature radius 1-25 mm. To check the radii of curvature, the template is applied to the product. The deviation of the radius of curvature of the product from the radius of curvature of the template is determined “through the light”.
Rice. 16. Set of radius templates: Fig. 17. Thread template set
1 - convex; 2 - concave
Threaded template- a tool for determining the pitch and profile angle of machine parts and other products. A steel plate 0.5-1 mm thick with teeth made along the axial profile of the thread (Fig. 17). There are templates for checking inch and metric threads. The template is applied to the thread being tested so that its teeth fit into the grooves of the thread. The correspondence of the pitch and angle of the thread profile to the pitch and angle of the template profile is determined by “clearance” or by the tightness of the fit of the template faces to the thread.
Measuring probe, used to control the gap between surfaces. It looks like a plate of a certain thickness. Measuring probes are manufactured with a thickness from 0.02 to 1 mm. Their main dimensions are standardized. They are produced in the form of sets of plates (Fig. 18) of different thicknesses in one holder. Used separately or in various combinations.
Rice. 18. Set of probes (all dimensions are indicated in millimeters):
L– probe length; S– thickness of the probe
Types of protractors:
UN– for measuring external angles from 0 to 180 0 and internal angles from 40 – 180 0; with a vernier reading value of 2/ (Fig. 19);
MIND– for measuring external angles from 0 to 180 0 with a vernier reading value of 2 / (minutes).
Rice. 19. Universal protractor
Work order
Exercise 1. Measuring gaps with a feeler gauge
Before measuring gaps with a feeler gauge, make sure that the feeler plates move smoothly.
If the movement of the plates in the gap is difficult, they should be lightly lubricated.
The size of the gap is determined by the total size of the set of probe plates that are completely included in the gap along its entire length.
When measuring the gap, do not apply great force to the feeler gauge to avoid breaking the plates or deforming them.
Exercise 2. Preparing for measurement
Familiarize yourself with the design of the protractor UN (Fig. 20).
Rice. 20. Goniometer UN
Vernier device: the angle between the extreme strokes of the vernier is 290 and is divided into 30 parts, but unlike the protractor, the UM is built on an arc of a larger radius, therefore, the distance between the strokes is greater, this makes it easier to read the readings (Fig. 20, b).
Installing a protractor for measuring angles:
if a square and a ruler are installed on the protractor (Fig. 21, a), then angles can be measured from 0 to 500;
if you remove the square and fix a ruler in its place, you can measure angles from 50 to 1400 (Fig. 21, b);
if you remove the ruler and leave only the square (Fig. 21, c), then you can measure angles from 140 to 2300;
in the absence of a ruler and square (Fig. 21, d), angles from 230 to 3200 can be measured.
Rice. 21. Installing a protractor for measuring angles
Preparing the protractor for work:
Before using the protractor, it must be thoroughly wiped;
check the condition of the protractor by external inspection: there are no scratches, signs of corrosion; clarity of scale and vernier strokes;
set the protractor to the zero position: the strokes of the base and vernier must match. If the strokes of the vernier and the base coincide, there should be no gap between the measuring surfaces of the protractor.
Measurement techniques:
place the protractor on the part being tested so that the ruler is aligned with the sides of the angle being measured;
with your right hand, lightly pressing the base ruler against the measuring surface, move the part gradually, reducing the clearance until complete contact;
if there is no clearance, fix the position with a stopper and read the reading.
Reading readings from the protractor UN:
Measuring external corners (Fig. 22, a – d):
when measuring external angles from 0 to 500 (Fig. 22, a), the readings are read on the right side of the scale (Fig. 22, b);
when measuring external angles from 50 to 900, readings are read on the left side of the scale (Fig. 22, c);
when measuring external angles from 90 to 1400, 900 is added to the readings on the right side of the scale (Fig. 22, d);
when measuring external angles from 140 to 1800, 900 is added to the readings on the left side of the scale (Fig. 22, d).
Rice. 22. Measuring external angles with an inclinometer UN
a – receiving a check, reading readings, b – from 0 to 500, c – from 50 to 900,
g – from 90 to 1400, d – from 140 to 1800
Measuring internal angles (Fig. 23, a – d):
when measuring internal angles from 180 to 1300, the readings on the right side of the scale are subtracted from 1800 (Fig. 23, b);
when measuring internal angles from 130 to 900, the readings on the left side of the scale are subtracted from 1800 (Fig. 23, d);
when measuring angles from 90 to 1400, the readings on the right side of the scale are subtracted from 900 (Fig. 23, c).
Rice. 23. Measuring internal angles with an inclinometer UN
A– receiving checks, reading readings, b– from 180 to 130 0, V– from 90 to 140 0,
G– from 180 to 90 0
NOTE
The accuracy of the reading obtained when measuring angular values or when setting a given angle is checked using a degree scale and a vernier.
On a degree scale, placed on the arc of the base, determine which whole division (or between them) the zero division of the vernier stopped, which corresponds to the number of whole degrees of angular magnitude.
Vernier scale determine which of its divisions coincides with the division of the degree scale, using the numbers of the vernier to determine the number of minutes, which is multiplied by 2 (the accuracy of the protractor).
Example. The zero stroke of the vernier passed the 34th division of the base scale, but did not reach the 35th; the 20th stroke coincided with the stroke of the main scale (not counting the zero division of the vernier stroke. Therefore, the measured angle is 34 0 20 x 2 = 34 0 40 / .
Security questions
What is a square, and in what metalworking operations is it used?
Name the patterns often used by a locksmith.
PRACTICAL WORK No. 4
Topic: “Measurements on an indicator stand, an indicator bore gauge and a depth gauge”
Purpose of the work : study the design, purpose, measurement techniques and readings of the indicator.
Types of indicators:
Clock type A) with measurement intervals: from 0 to 5 mm; from 0 to 10 mm and small-sized - from 0 to 2 mm.
Face with the measuring rod moving perpendicular to the scale (Fig. 24, b).
Purpose – relative, or comparative, measurement and verification of minor deviations from the shape, size, as well as the relative position of the surfaces of parts; for measuring the horizontal and vertical position of the planes of individual parts, ovality, taper of shafts, cylinders; runout of gears, pulleys, spindles and other rotating parts.
Work order
Exercise 1. Studying the instructions and design of the ICH indicator
Familiarize yourself with the design of the ICH indicator (Fig. 24, a).
Rice. 24. ICH indicator:
A– clock type: 1 – square, 2 – holders, 3 – vernier, 4 – screw nut, 5 – stopper, 6 – semicircular base, 7 – sector, 8 – base ruler, 9 – removable ruler;
b– end, V– indicator circuit
The indicator diagram is shown in Fig. 24, V: 1 – a measuring rod with teeth on one side, 2 – indicator housing, 3 – small gear on the same axis with the arrow, 4 – large gear drive wheel relative to the gear wheel 3, 5 – spring, 6 – small gear (drive), sitting on the same axis with the gear 4 and in mesh with the teeth of the rod rack 1 , 7 - arrow, 8 - clock face; 9 – spring.
The indicator scale is shown in Fig. 24, A: Dial 3 indicators are divided into 100 equal parts. The value of each division is 0.01 mm.
Small dial 6 (Fig. 24, b) with divisions for counting full revolutions. For one full revolution, the arrow moves one division equal to 1 mm.
Exercise 2. Preparing the indicator for measurement
The measuring rod should move easily along the sleeve and not jam.
The spring that creates the measuring pressure should pull the rod with the tip to its extreme position, while the indicator arrow should give a constant indication.
The indicator contains very thin small gears, axles, and springs that must be protected from shocks and impacts to avoid their breakage and failure.
The indicator should be protected from moisture, dirt and external mechanical influences. Do not bend the measuring rod.
Exercise 3. Setting the indicator to the initial (zero) position
For any measurement, you need to set the indicator to the initial position (Fig. 24).
Clock face 3 (Fig. 24, a) turn by the grooved rim 4 or turn the head 11 (with a stationary dial), install the bezel relative to the arrow, secure with a stopper 2 .
Measuring tip 9 with removable ball 10 bring into contact with the surface of the slab (Fig. 25, A) or installation measures 9 block of tiles, fig. 25, b). Place the arrow against any scale division. Further readings should be made from this reading as from the initial one.
Rice. 25. Setting the indicator to the zero position: A- on the stove, b– end measures
Exercise 4. Techniques for checking with an indicator
Accurately install the part being tested (Fig. 26, A).
Install the indicator on a tripod (Fig. 26, A).
Working surface of the indicator measuring rod 1 bring into contact with the surface of the part being tested 2 so that the arrow makes one or two turns (Fig. 26, b).
Note the starting position of the arrow 5 (see Fig. 24, A) and pointer 6 on the dial. Count from this reading as from the initial one.
Move the measuring rod of the indicator relative to the surface of the part being measured or the surface to be measured relative to the indicator (Fig. 26, a, b).
Rice. 26. Techniques for checking with an indicator:
A– moving the part being tested, b– moving the indicator
Exercise 5. Reading the indicator
Count whole numbers of millimeters with an arrow 6 (see Fig. 24, A), hundredths of a millimeter are counted on a large scale 3 .
Security questions
What are the purposes of measuring indicators?
What are calipers and bore gauges, what are they, where are they used?
Evaluation criteria
For a correctly completed report, with answers to all control questions, a mark of five points is given.
If there are minor errors (spelling errors, sloppy work), the overall score is reduced by 10%.
If there are significant errors (incorrect answers to control questions), the mark is reduced to 50%.
The defense of laboratory work is carried out in writing and lasts 10 minutes. A correct answer to each question is awarded one point.
Makienko N.I. Practical work in plumbing: Textbook. manual for prof. tech. schools – M.: 1982. – 208 p.
Pokrovsky B.S. General plumbing course: Textbook. allowance. – M.: JIC “Academy”, 2007 – 80 p.
Pokrovsky B.S. Basics of plumbing. Workbook. – M.: JIC “Academy”, 2008.
Pokrovsky B.S. Basics of plumbing: A textbook for beginners. prof. education. – M.: JIC “Academy”, 2007. – 272 p.
Pokrovsky B.S., Skakun V.A. Plumbing: Album of posters. – M.: JIC “Academy”, 2005. – 30 pcs.
FROM WORK EXPERIENCE
Master
production
training
Alexandrov Dmitry Gennadievich
working on
individual methodological topic: “Development
practical techniques, skills and abilities in the classroom
educational practice".
Practical training sessions are conducted in the educational
workshop with the aim of developing in students
systems of practical professional techniques,
skills and abilities, by including them in
educational and production activities.
And
Taking into account individual characteristics,
level of preparedness
abilities
students, as well as real educational materials
and other conditions, the master of the p/o outlines who, what and
how much work will be performed establishes the total
number of educational and production works per group,
prepares materials, workpieces, tools,
accessories - everything necessary for high-quality
conducting a lesson. At the same time, he is personally convinced of
serviceability
devices,
tools, checks the quality of materials and
compliance of the workpieces with the requirements of the drawing, diagram and
technical documentation.
equipment,
Dmitry Gennadievich builds the process
training so that learners effectively
perceived and assimilated new things, relying on previously
learned, and was its continuation and development,
then “bridges are built” in the minds of students
between what they know and can do and what they need
to be learned and mastered.
During the exercises, master p/o
constantly encourages students to use
knowledge, justification of the techniques being practiced and
ways, he himself gives the necessary explanations,
uses other methods of linking the known,
practiced with what is being studied, practiced on
lesson.
Practical tasks in plumbing practice
(by topic)
Marking
1. Develop a device for marking drilling points
holes for the handle in a hammer with a square striker.
2. Develop a device for marking drilling points
under bases for bench vices.
3. Design and produce templates for
various educational and production work in the workshop (according to
students' choice).
4. Develop a device for marking holes
fastening the faceplate of a lathe.
5. In a cylindrical part at the same distance from
two holes must be drilled at the end. How to do
marking the centers of these holes, if, in addition to their distance from
end, only the length of the arc between them is known?
6. Develop a device that allows you to provide
the correct sharpening angle of the chisel, cross-section when chopping
various metals (steel, cast iron, non-ferrous alloys).
7. Develop a device for bending sheet metal
at different angles (in this case, the maximum
thickness and width of the metal being bent).
8. Develop a device that allows you to bend steel
wire, rod with a diameter of up to 8 mm in two planes
(the design must be such that it allows
receive rings, change the bending angle). Purpose
accessories for making flower stands.
Metal cutting
9. Develop such a design for a hacksaw machine,
which would allow cutting sheet metal
to a significantly greater depth than when cutting conventional
hacksaw for metal.
10. Develop a device that allows you to provide
cutting line exactly according to the markings (the hacksaw blade is not
should lead away from the marking line).
11. Design devices for
electric drill, including for cutting sheet metal
metal and profiles of various sections using a drill.
12. Develop a device that provides accurate
sharpening angle of chair scissors blades.
Metal filing
13. Design such a file handle,
which would not rub calluses on the palms while working.
14. In a small piece of thin tin it is necessary to make
square hole with side 9 mm. How to do it
if you have a round file with a diameter of 10 on hand
mm, bench with a vice, mallet, ruler with
in millimeter divisions?
15. Develop such a design of file teeth (in
including removable ones) that would not become clogged with chips when
filing of tough metals.
16. Develop such a rotating design
file and such processing technology that
would allow filing in two planes
simultaneously. In this case, the filing planes should
be as follows:
mutually perpendicular;
at an acute angle to each other;
at an obtuse angle to each other.
Drilling metal
17. Develop a device that allows you to provide
perpendicularity of drilling and limit depth
drilling.
18. Develop a device that allows you to provide
the correct sharpening angle for a twist drill.
19. When drilling holes in thin sheet material,
due to the fact that the guide strips of the drill are not
participate in the work, the holes turn out to be angular. How
drill a hole in such material with the correct
forms?
20. The most difficult operation in the manufacture of metalwork
hammer in the workshop is to make in it
window blank for handle. This is usually done by drilling
there are two holes next to each other, and then the remaining one is cut out
jumper. The work can be greatly simplified if
Do not cut out the remaining jumper, but drill it out. How
at the same time, ensure that the drill does not fall into earlier
drilled hole?
Threading
21. Develop a device that allows you to provide
perpendicularity to the hole axis at the beginning of cutting
threads with a tap.
22. In a cylindrical rod with a diameter of 30 mm and a length
A 10.1 mm hole was drilled 50 mm along its axis
depth 36 mm. This hole is cut to a depth of 28 mm.
M12 thread. Draw this rod with a screw screwed into it
up to half the thread with a screw. Screw shape and size
choose for yourself.
23. Design the universal joint,
allowing for mechanized deployment (carrying it out
using a pneumatic gun).
24. When cutting threads in blind holes due to
Large loads may cause the tap to break. Suggest
design of a collar that would limit the attached
to the force tap.
25. Can you answer why in mechanical engineering
use hex head bolts, and in
construction business with tetrahedral?
Answer: square bolt head and square
the nut is stronger, since when the bolts are tightened, their edges are smaller
crumple under the pressure of a wrench and allow
high tightening forces.
But apply them in
mechanical engineering is inconvenient.
To use a wrench to screw a square nut onto
bolt, the key must be turned at least 90°,
otherwise you will not be able to grab the nut with a wrench
next turn. We meet in the construction business
with large parts (pillars, racks, slopes, etc.),
allowing you to turn the nuts with a wrench to any angle.
But when installing machines and mechanisms, very often bolts and
nuts are located in places where it is impossible
turn the wrench 90°. In these places
It will not be possible to tighten the square nut with a wrench.
That is why hex nuts are used in mechanical engineering.
and hex bolts. Such a nut or bolt
can be tightened by turning the wrench just one
60°, and if we take into account that the key handle is rotated relative to
heads at 30°, then the hex nut can be
tighten by turning the key only 30° and turning over
it for the next nut grip. Further increase
the number of edges of the nuts does not provide tangible convenience for their
wrapping, but leads to a decrease in the areas of the faces,
makes the angles between the faces more obtuse, and this reduces
their strength. The edges of the nuts will wrinkle from the pressure
wrench.
Related articles
The best amulets against the evil eye and damage Amulet against the evil eye with hands for children
How to read the Psalter correctly
Delicious dishes with sausages
A glimpse of Bella. Romantic chronicle. A glimpse of genius. Messerer about Akhmadulina Boris Messerer glimpse of Bella romantic chronicle
I dreamed that I was sailing on a boat on the river
How to cook beef entrecote in a frying pan
About the company Foreign language courses at Moscow State University
Which city and why became the main one in Ancient Mesopotamia?
Why Bukhsoft Online is better than a regular accounting program!
Which year is a leap year and how to calculate it