This tutorial, unlike other textbooks and manuals on plumbing, contains detailed description specific working techniques and methods for the practical implementation of basic plumbing operations and types of work in a certain technological sequence.Tutorial is intended for industrial training instructors to assist in conducting practical classes in the preparation of locksmiths of various specialties: locksmiths for mechanical assembly work, locksmiths for instrumentation and automation, repairmen, car repairmen and workers in other specialties. The manual covers the material of the main works of 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 receive it.
The file will be sent to your Kindle account. It may take up to 1-5 minutes before you receive it.
Please note you "ve to add our email [email protected]
to approved email 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. pp "training workers in production L?"! T * "Additional. - m. FOREWORD 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" set the task of improving the quality of vocational training and education of workers in production, to create conditions for continuous improving their skills in accordance with the requirements social development and scientific and technological progress. This tutorial, unlike other books and manuals on plumbing, contains a detailed description of specific working techniques and methods for the practical implementation of basic plumbing operations and types of work in a certain technological sequence. The textbook is intended for industrial training instructors to assist in conducting practical classes in the preparation of locksmiths of various specialties: locksmiths for mechanical assembly work, locksmiths for instrumentation and automation, repairmen, car repairmen and workers of other specialties. The manual covers the material of the main works of the general plumbing course and corresponds to the topics of the curriculum. The material on each main issue provides for mastering the skills to perform 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 certain techniques and operations of marking, cutting, cutting, filing, etc. in necessary cases training exercises should be performed. The manual contains a detailed description of the production operations, techniques and methods of work with specific recommendations on what to do and how to do it. When performing operations, it is planned to use mechanized tools and various devices that increase labor productivity and product quality. To control production work and compliance technical requirements it is necessary to comply with the rules for the application and methods of using control and measuring instruments and devices. Special attention in the manual is given to the requirements of labor safety. - At the end of each chapter there are test questions that are used by the industrial training instructor to check mastery educational material. I* GENERAL REQUIREMENTS FOR LABOR SAFETY AND ORGANIZATION OF THE WORKPLACE industrial training in enterprises, the instructor should conduct detailed briefing, monitor sa compliance with labor safety requirements and achieve the assimilation of these rules and instructions by each student. The instructor is obliged to provide training sessions with warning posters on labor safety requirements, posting them in prominent places; if necessary, students should be provided depending on the training and production tasks they perform written instructions on the requirements of labor safety, industrial sanitation and fire safety. There are certain requirements for the organization of the locksmith's workplace. 1. The workbench must be strong and stable. Tabletop. (lid) 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 the person working nearby from fragments flying off during cutting. 2. Parallel swivel vise must be firmly and securely mounted on the workbench. In the compressed position, the jaws are parallel and at the same level. by the force of the hands, not by the weight of the body. Clamping "or releasing parts from the vise, the lever must be lowered smoothly, without throwing it, so as not to hurt the arm or leg. Keep the vise clean and in good condition, and regularly lubricate the rubbing parts with the appropriate lubricant. 3 A footrest should be used in cases where the height of the vise does not correspond to the height of the student.The height of the workbench with a vice is considered normal if the student standing straight has an arm bent at the elbow joint at an angle of 90 °, is at the level of the vise jaws 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, makes it difficult correct execution working methods and obtaining the required accuracy. 4. One of the elements of culture in the workplace is properly fitted, neat and clean overalls. A dressing gown or 4 overalls should be chosen according to the size and height of the worker and should not restrict movement. During work, overalls should always be fastened with all buttons, and the sleeves should have fastened cuffs that tightly cover the wrist; a headdress (beret or scarf) must be worn on the head, under which it is necessary to carefully remove the hair. Clothing and headgear should not have hanging ends (tie, ribbons, ends of scarves), which can be caught by 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 cover to direct light to the workpiece and the plane of the workbench. The voltage in the mains with local lighting should not be "G! ~, l R Fig. 1. A diagram explaining the principle of exceeding do V. the location of tools, workpieces 6. At the workplace, only those tools and devices MUST be documentation at the workplace that are necessary to complete the training and production task.Each tool, fixtures and materials should have its own specific place.Tools, fixtures and materials should 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 worker (Fig. 1). A certain order must also be maintained in the drawer, where each tool must be assigned permanent place. Measuring and calibration tools are placed separately from the working tool on a special shelf or tablet. Drawings and maps for training tasks should be placed on a tablet-stand installed on a workbench at a distance sufficient to read them. MARKING FLAT SURFACES Labor safety requirements» Starting to teach marking flat surfaces, the instructor must carefully examine all the tools and fixtures. It is forbidden to work with a faulty and incorrectly sharpened tool. Tools in use must meet the following requirements. Hammers must be firmly mounted on the handles and wedged in the holes with steel wedges. The hammer handle should 5 have an oval section with a uniform thickening towards the end. The surface of the handle must be clean and smooth, free of knots, cracks and chips. The length of the handle for marking hammers weighing 200 g should be 250-300 mm. The working surfaces of the hammer must be smooth, flat surface, no cracks or breaks. The impact part of the punches should not be knocked down or beveled from impacts. The surface of the impact part should be smooth and slightly convex. The length of the punch must be at least 70 mm so that the impact part of the tool taken in hand is 20 mm higher than the yalts. The working part of the center punch should be a point sharpened into a cone with an angle at the top of 60 °, and for marking the centers of the holes to be drilled, with an angle at the top of 45 °. Do not use a blunt center punch, because when you hit it with a hammer, the tip slides off the marking plane and can cause injury to your hands. Impacts should be applied to the impact part along the axis of the center punch when it perpendicular arrangement to the plane of the workpiece. To prevent injuries to the hands, it is necessary to carefully handle the pointed ends of the compass, scriber and center punch; these tools should not be placed in clothing pockets. Consider the requirements of labor safety when working on grinding machines. General requirements. 1. Work only on a machine to which you are authorized, doing the work that you have been assigned. 2. It is forbidden to work on the machine with mittens or gloves, as well as with bandaged fingers. 3. In the event of a power outage, switch off the electrical equipment of the machine immediately. 4. Every worker is obliged; a) strictly comply with all labor safety requirements; b) keep 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 starting work. 5. Before switching on the machine, make sure that no one is endangered by starting the machine. 6. Tidy up your overalls. 7. Check the strength of the guards." work without guards grinding wheel and belt drive is prohibited. 8. Check the reliability and correct fixing of the hand rest (the gap between the hand rest and the grinding wheels should be no more than 3 mm), check the condition of these wheels by external inspection in order to determine noticeable cracks and potholes. It is forbidden to use circles that have cracks and potholes. 9. Check the correct operation of the machine at idle for 3-5 minutes, being away from the danger zone of a possible rupture of the grinding wheel, and make sure that there is no excessive radial or axial runout of the wheel. 10. If you find a malfunction of the machine or a possible danger, immediately inform the instructor or master. During work. 11. When sharpening the tool, it is necessary to feed the tool onto the wheel smoothly, without jerks and strong pressure. You should stand away from the plane of rotation of the grinding wheel. 12. When working, the worker must use goggles or screens. 13. Sharpening and finishing the tool with grinding wheels * should be done only with cooling. During work, to increase the service life and safety of tools, it is necessary: 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; it must be protected from nicks, scratches and other damage. After completion of work, it is necessary: 1. To avoid corrosion, wipe the tool dry with a clean cloth, and then lubricate with a thin layer of oil. Measuring tool store in cases (each tool should have its own place). It is forbidden to store the tool "in bulk". 3. Rinse the marking plate with kerosene and wipe it with a dry, clean cloth, grease with oil and cover with a protective wooden lid. Preparation of surfaces for marking. Marking work in plumbing is an auxiliary technological operation, which consists in transferring contour constructions according to the dimensions indicated on the drawing to the workpiece. The marking exercise is usually performed on sheet steel plates, with two adjacent edges of each plate being straight and at an angle of 90°. Prepare for surface marking next sequence. 1. Preparation of dyes. For painting 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 to dry it quickly, wood glue is added to the dye (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 blue vitriol(two or three teaspoons of copper sulphate crystals per glass of water) or a special marking varnish. F 2. Preparing the workpiece for painting. When preparing blanks for painting, they are cleaned of dust, dirt, scale and rust with a steel brush. Inserts must be free of burrs and sharp corners. One plate on both sides is cleaned with sandpaper, and the planes of the remaining plates are left untreated. 3. Coloring 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 brushes. The solution should be collected only with the end of the brush in a small amount to avoid the formation of smudges. Cleaned planes are stained with a solution of vitriol, and untreated planes - with chalk staining of the plate. 2. Applying the dye for preparing the solution. Dry after finishing. Applying parallel lines. Drawing marks at an arbitrary distance from each other is done with a scriber using a square with a heel in the following sequence. 1. The plate is placed on the marking plate in such a way that the machined edge, which is taken as the marking base, is facing the worker. For a snug 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 the scratches, the tip of the scriber is pressed tightly against the edge of the square (Fig. 3, b), while tilting the scriber in the direction of movement. To obtain a clear and straight line, a risk should be drawn with a little pressure, without changing the inclination of the scriber relative to the narrow edge of the square. It is impossible for the same risk to pass twice, since the line will turn out to be forked. Two types of scribers are used for drawing risks; round (Fig. 4, b) or with an insertion needle made of hard alloy (Fig. 4, c). 3. The square is moved along the edge of the plate at arbitrary distances and a number of marks are applied. Parallel risks at a given distance from each other are applied using a measuring ruler and a scriber. Rice. Fig. 3. The positions of the square with a 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 markup is performed in the following sequence. 1. Using a measuring ruler and a scriber, two marks are applied to the plate a at a distance of 5 mm from the baseline (the method is shown in Fig. 6, a). c^^wsh) %^ DVD £ Fig. 4. Drawing risks with the help of a scriber: a - acceptance of work; b - round scriber; c - scriber with a plug-in needle ^ 1 - needle; 2 - body; 3 - spare needles; 4 - cork 2. A ruler is applied to the marked plane so that its edge coincides with the strokes of marks a. With the fingers of the left hand widely spaced, they press the ruler against the plate, and with the right hand they apply the risk with a scriber (Fig. 6, b). A similar markup for marking is performed for the remaining parallel lines located at a distance of 6, 13, 21, 29, 38, 47, 55 mm from the baseline (Fig. 6, a), and carry out risks. 3. The accuracy of drawing marks according to the given sizes is checked, ----- h ^ D "1, S5 "-a * - 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 direct risks CD, CB and BD, an inscribed equilateral triangle is obtained. 1 Fig. Fig. 15. Division of a circle into three parts with the construction of an inscribed triangle Fig. 16. Division of a circle into six parts with the construction of an inscribed hexagon Fig. 14. Reception of marking a square 5. The correctness of the construction is checked with a compass, setting the compass opening equal to the length of one of the sides of the triangle and determining the equality of the remaining sides of the triangle * by the same size. Learning 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. On the ruler, they put a risk passing through the center of the circle and intersecting it at points A and B. 13 3. From point A, as from the center, an arc is applied with a radius equal to the radius of the drawn circle, and get points / and 2. A similar construction is done from point B, drawing 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. Connecting the points with direct risks A-2, 2-4, 4-B, B-3, 3-/ and 1-A, an inscribed hexagon is obtained. When marking the faces of the hexagon to 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 deposition of dimensions from the edges and the center line. Techniques for planar marking of various contours of parts depend on the selected one. 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 center (axial) are taken as marking bases lines.Study task 1 contains the marking of a flat square with the dimensions measured from the edge of the workpiece.Marking is carried out using a ruler, a compass and a scriber in the following sequence. (Fig. 18) 2. The same allowance is set aside from the other edge and a mark b is drawn perpendicular to the mark a. 3. Parallel to the risks a and b at a distance of 20 mm, draw a mark ax and bg. 4. From the top of the 90 ° angle at the mark and set aside a size of 100 mm (point /) and at risk b - a size of 63 mm (point 2). 5. From the point / perpendicular to the risk a, apply the risk crossing the risk ah. Similarly, a risk is drawn from point 2. 6. At the top of the inner corner of 90 ° parallel to the risks ax and b (rises a2 and b2 are drawn at a distance of 2 mm from them. 7. An angular groove 2 mm wide is marked from the top of the inner corner, completing the marking of the entire contour 1. According to the drawing (Fig. 19), the marking base is taken as the marking base from the axial (center) line. 2. At a distance of 30 mm from the boundaries of the marking of the contour of the square, two perpendicular risks are drawn, intersecting at point O. Fig. 19. Marking the flange Fig. 20. Receiving the marking of the part from the center line 3. Circles R = 10 are drawn from point O , 17, 25 mm (Fig. 20). Points 1-4 of the intersection of the circle R = 17 mm with the center lines will be the centers of the circles R = 3 mm. according to the template In mass production, to increase labor productivity when performing marking work, marking templates are used. Rice. 21. Nut pattern 22. Reception of markup to the template The sequence of markup of the wrench according to the template is as follows. 1. A marking template is applied to the workpiece (Fig. 21) so that it fits snugly against the plane of the workpiece along the entire contour. To prevent displacement of the template, it is strengthened with two clamps (Fig. 22). 2. The workpiece is placed on the marking plate and the edge of the scriber is drawn along the edge of the template along the entire contour to be marked. Particular attention should be paid to the correct position of the scriber relative to the side face of the template. To ensure the W [spanner wrench in terms of marking accuracy, the tip of the scriber must be" at the top of the angle formed by the face of the template and the plane of the workpiece. Building scans of bodies shaped like a cube, cylinder and cone. Sometimes a locksmith has to make products in the form of a cube, cylinder and cone from sheet metal In the manufacture of products of a similar shape, the first operation will be the construction of surface developments according to the main specified dimensions of the figures.This exercise consists of three tasks.Study task 1 contains the construction of a development of a cubic vessel on sheet steel.100 ./ Fig. 23. Development of a cubic vessel Fig. 24 An example of constructing a development of a cubic vessel i> A r 1 "and -■-i-| *! z k / ^r c A development of the surface of a cubic vessel can be obtained if the side faces /-4 are turned from a vertical position to a horizontal one (Fig. 23). "The sequence of 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, a square 5 with a side of 100 mm is built. 3. Build squares 1-4. 4. To connect the planes at the two sides of the squares 3 and 4, mark the 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 unfolded 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 the task is as follows: 1. Determine the length of the cylinder sweep 0 70 (Fig. 25): L = nD 3.14-70 = 219.8 mm (round up to 220 mm). 2. Build a development of the cylindrical surface of the vessel with a height H = 120 mm and a length L = 220 mm (Fig. 25, a). 16 3. The development of the cylindrical surface is supplemented with an allowance for the side seam. For flanging the upper edge of the cylinder with rolling the wire, take the allowance b \u003d nd (d is the diameter of the wire). 4. Mark the bottom of the vessel (Fig. 25, b), for this, two circles are applied R = 35 mm (cylinder base) and R = 35 + a (with a seam allowance), which completes the complete marking 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) g) Fig. 29. Acceptance of work with a spring or electric center punch: a - installation of a center punch at risk with an inclination; b - vertical installation and deep core holes; - in - spring kerier (d - electric punch) A similar technique when moving can be applied to intersecting risks, where, when moving, the tip of the center punch will find the deepening point of two intersecting marks. Learning task 2 consists in punching marking marks with a spring or electric center punch (Fig. ). These punches, in comparison with ordinary ones, provide increased accuracy of punching and obtaining small depressions of the same size, increase labor productivity, facilitate the work of the worker. The task is performed in the following sequence: (Fig. 29, a) 2. The spring center punch is set perpendicular to the plane to be marked, without moving the tip of the center punch from the mark (Fig. 29, b) 3. Lightly press the cap with the fingers of the hand. the spring will strike the striker rod, the tip Fig. 30. Sharpening the center punch: Fig. 30. 31. Checking the sharpening of the core "a - the position of the hands; b - placement of a conical part of the ner according to the template - on the plane of the abrasive wheel of which the core recess will make. The impact force of the punch striker is adjusted by turning the cap (compressing or weakening the spring). All conical recesses are the same size, since the force of impact with one adjustment is always the same. 4. The center punch is removed from the surface of the part to be marked and returned to its original (working) position. 5. The center punch is moved along the risk and the methods of 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 must press the center punch housing down). Sharpening Tserner, scriber and compass legs. The quality of the markup largely depends on the serviceability and correctness of the sharpening of the marking tool. Before starting work, it is necessary to study the safety requirements for working on grinding machines, set out at the beginning of this chapter. Center punches (Fig. 30) are sharpened in the following sequence. 1. Put on safety goggles and turn on the grinder motor. 20 2. The center punch is taken with the left hand by the middle, and with the right hand - by the end opposite to the one being sharpened. 3. Maintaining the angle of inclination relative to the grinding wheel, with light pressure, apply the center punch with a cone to the rotating circle, with the fingers of the right hand, evenly rotate the center punch around its axis. 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 center punch is periodically cooled in water to avoid the release of its working part. 4. Checking the correctness of sharpening is carried out according to the template (Fig. 31). Rice. 33. Sharpening the legs of the compass: a - reception of work; b - a sample of sharpening the legs of the compass The scriber (Fig. 32) is sharpened in the same sequence as the center punch. Consider the sequence of sharpening the legs of the compass (Fig. 33). 1. The compass is taken with the left hand by the middle, below the arc with the locking screw, and with the right hand - by the swivel of the two legs (the legs should be in close contact), 21 - 2. With light pressure, the compass is brought to the grinding wheel in such a way that the leg the compass was in relation to the circle at a certain angle, and the end of the first leg is 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 brought to a bar, while removing burrs on the inner planes of the legs and on the side faces of the conical part. With proper sharpening, both ends should have the same length and taper with the top of the corner at the adjacent plane of contact of the legs (Fig. 33, b). CONTROL QUESTIONS 1. Why and how are the surfaces of the marked workpieces prepared? 2. Why do marking lines need to be applied in one go? 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. With what kind of center punch do marking risks are punched, in what places and at what distance are core recesses made? 6. What labor safety requirements must be observed when sharpening marking tools on a grinding machine? CUTTING Occupational safety requirements. Before carrying out training work on cutting, the instructor of industrial training is obliged to carefully examine all the tools and devices. 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 and spalls, and the handle should have an oval section with a uniform thickening towards the end; the surface of the handle must be clean and smooth, without knots, cracks and chips; the length of the handle for hammers weighing 500-600 g should be 350-380 mm; b) chisels and crosscuts must not have cracks and spalls; the ribs of the lateral sides of the middle part must be rounded and ground, the surface of the striking part is smooth and slightly convex, the length of the chisel or cross-cut must be such that its striking part is at a distance of 25 mm from the thumb. The angle of sharpening of the chisel and crosscut varies within 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 the same bevel width. During classes, the instructor should pay special attention to the installation of heavy parts in the vise, as they easily break out of the vise and can cause bruises to the hands and feet of the students. The instructor 22 must also make sure that the pieces of metal being cut off fly off towards the protective grid, and the worker has goggles. To protect hands from damage (during the initial period of training), a safety rubber washer should be put on the chisel. Before starting work on grinding machines, the instructor must check the students' knowledge of the requirements for safe work on grinding machines, set out in Ch. 2. Let's consider the general requirements for safe work with hand pneumatic tools. 1. It is forbidden: a) to work with a pneumatic tool without gloves; b) to hold a pneumatic tool by the hose or working tool and. work them on a ladder; c) to repair and partially disassemble the pneumatic tool without disconnecting it from the air duct; d) insert and remove the working tool during the operation of the pneumatic tool. 2. The hose must not have kinks, breaks or abrasions. 3. Avoid pulling, kinking or kinking the hose. 4. Connect the rubber hose to the pneumatic tool only when the air valve on the supply line is closed. 5. Before disconnecting the hose from the pneumatic tool, close the valve that supplies compressed air from the air line to the hose (compressed air escaping from the hose opening can pull the hose out of your hands and cause injury). 6. It is necessary to check for strength the fastening of all parts of the tool, the presence of lubricant in bearings and rubbing parts. In addition to the general, there are additional labor safety requirements. For example, when working with a pneumatic hammer: a) protective goggles must be worn; fence the felling place with a metal mesh; b) when adjusting the number of blows, you can not try the hammer, supporting the striker 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 is in the working position. Wrist blow with a hammer. When cutting metal, the quality of processing depends on the correct methods of working with a percussion tool (hammer). The impact force 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 the hammer. At the workplace, the hammer should lie on the right side of the vise and be turned to them with a round striker. The training device for impacts is placed on the left side of the vise with the clamping part towards the worker. The device is installed bn the middle part of the vise jaws. Sponges are clamped only by the force of the hands, and not by the mass of the whole body. 2» Labor productivity and fatigue reduction depend on maintaining the correct position of the feet and body of the worker. The height of the vice position should correspond to the growth of the worker, and with the vertical position of the body of the worker 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 parts of the arm should be equal to 90 °. When chopping, you should stand straight and steady, half-turned to the vice. 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 shock part (Fig. 35). The wrist strike is carried out by moving only the hand without bending the elbow (Fig. 36, a). 36: Methods of holding the hammer during chopping: a "without unclenching the fingers; b -> with unclenching the fingers 24. There is a wrist strike, in which at the beginning of the swing, when the hand moves upwards, the hammer handle is held with all fingers with a slight unclenching of three fingers (Fig. 36, b).When hit, all fingers are squeezed, bending the hand forward, strike the head of the training device. Elbow blow with a hammer. The exercise provides for training movements, with a hammer at an elbow blow. The positions of the feet, the body body and holding the device with the left hand during this exercise the same as when performing a wrist strike. Hammer blows are made on the head of the device with the help of a complex movement of the right hand (Fig. 37). Rice. Fig. 37. Movement of the hand during lok- Fig. 38. Movement of the hand during a foul blow with a chevy blow When swinging the hammer up, first the hand is bent at the wrist, and then at the elbow. At the end of the stroke, the little finger, ring and middle fingers are slightly unclenched. When striking, first with all fingers they squeeze the handle of the hammer, then they make a sharp movement of the elbow part of the arm away from themselves and, finally, straighten the wrist. Shoulder blow 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 deliver well-aimed blows with a hammer on the shock part of the device. The movement of the right hand must be carried out according to the following complex scheme. When swinging, the arm is bent simultaneously at the wrist, elbow and shoulder joint with full coverage of the hammer handle with all fingers of the hand. At the end of the stroke, the little finger, ring and middle fingers are unclenched (Fig. 38). Upon impact, the shoulder part of the arm is sharply lowered down, at the same time the arm is unbent at the elbow, completing the impact by straightening the wrist. Hitting a chisel with a hammer. To do this job, the chisel must be dulled. On the workbench, it is placed on the left side of the vise with the cutting part facing the worker. 2 "Pig-iron tiles are installed horizontally (above the vise level by b-10 mm). 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 impact part and the chisel is 20-25 mm. (The correct position of the legs and body was discussed earlier.) The chisel is set against the stop on the cast-iron tile at an angle of 45 ° to the axis of the vise jaws and at an angle of 30-35 ° to the horizon. During the application of hand blows with a hammer on the chisel (Fig. 39), the student should look only at the working part of the chisel. To protect the left hand from possible bruises during a miss, a rubber washer is put on the chisel. a) b) C) Fig. 39. Work with a chisel: o - the position of the chisel on the tile; b "* - reception of holding a chisel; c - reception of work Cutting of sheet steel according to the level of vise jaws. 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 vise jaws so that the marking risk is at the level of the vise jaws. 2. The chisel is taken in the left hand, the hammer in the right and take the correct stance. 3. The chisel is set 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 comes into contact with the material being cut off for 2/3 of its length. The angle of inclination of the chisel to the surface to be treated should be 30-35° (Fig. 40, a), and the angle of inclination of the chisel to the axis of the vise jaws should be 45° (Fig. 40, b). Such installation of the chisel ensures the least fatigue of the worker and does not allow damage to the surface of the jaw and the cutting part of the chisel. 4. Cutting is done only with a well-sharpened chisel. With the right hand, they 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 sheared, weakening the blows at the end of the cabin until the metal is completely sheared at the first risk. With this cutting method, the cut layer is always twisted and is not used in the future. 26 After the cutting is completed, at the first risk, put a hammer and a chisel on a workbench, open the vise, rearrange the workpiece with the second risk up at the level of the jaws and repeat the cutting. In the same way, excess metal should be cut off for other risks. Training task 2 on cutting material in a vice according to marked risks is performed in the same sequence as cutting at the vice level, but using a different cutting method, with. which the sheet material is not deformed. 1. Pick up a chisel and a hammer, take the correct stance. Rice. 40. Cutting metal at the level of the vise jaws: a - installing a chisel at an angle to the horizon; 6 - installation of a chisel at an angle to the axis of the jaws of the giskov Fig. Fig. 41. Cutting metal according to the level of the vise jaws: a - setting the chisel at an angle to the horn; b - installation of a chisel at an angle to the axis of the vise jaws 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 at 30-35 h (Fig. 41, a), and the axis the chisel was perpendicular to the plane of the workpiece (Fig. 41, b). 3. With the right hand, light blows are applied to the chisel with a hammer, and with the left, in the interval between blows, the chisel is moved in the figure by 2/3 of the length of the cutting edge, performing a preliminary notching along the entire length of the risk. 4. The felling is continued with strong blows with the chisel moving in several passes (using elbow and shoulder blows). At the end of cutting, the impact force is weakened until the complete separation of one part of the metal from the other. Sheet material with a thickness of 3-5 mm is cut in two steps. First, a deep (not less than half the sheet thickness) notching is made on one side of the workpiece, and then it is turned over on the other side. goy side and cut completely, combining hammer blows with the movement of the chisel. Cutting steel above the level of the vise jaws. Consider the method of cutting strip or thick sheet material at risks located above the level of the vise. 1. The risks that limit the amount of felling are marked with marking tools. The cutting performance, processing accuracy and roughness of the machined surface are affected by the thickness of the cut layer (chips), therefore it is practically established that the thickness of the chips should not exceed 0.5-1 mm. After marking the marks on both sides of the workpiece, inclined marks (bevels) are applied, which are the initial plane at the initial moment of felling. 2. The workpiece is clamped in a vice and the bevels are cut down using the previously studied method (cutting according to the level of the vise). 3. The workpiece is installed in the middle part between the vice jaws so that the line is directed parallel to the jaws and is located 4-8 mm above their level. With this approach, Fig. 42. Installation of the chisel during felling, special attention should be paid to the metal above the level of the jaws of the TVS: be given to the reliability of fastening at an angle to the horizon; b - along the axis of the rumble of the workpiece in a vice for the side of the vice to prevent its displacement between the jaws. 4. Picking up a chisel and a hammer, take a working position; the middle part of the cutting edge of the chisel is set on the edge of the bevel (strictly at the first risk). The angle of inclination of the chisel to the surface to be treated should be 30-35 ° (Fig. 42, a), and in relation to the axis of the vise jaws it should be located along the cut layer (Fig. 42, b). 5. When cutting metal, elbow blows are applied. As the chips are cut, the left hand with the chisel will move along the edge of the workpiece. Usually, when cutting, it is necessary 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 the metal layer. A confirmation of the correctness of the choice of the angle of inclination of the chisel will be a chip uniform in thickness. At the end of the cutting, the force of impact is weakened in order to avoid the breakage of the chisel and damage to the hands. The same methods are used for felling according to the following risks. The straightness of the cut plane is checked with a ruler. £8 Cutting metal with a hinged blow. Side impact cutting is the most effective and is used for large workpieces when it is not possible to use cutting in a vise. Training task 1 for cutting strip and round metal on an anvil (plate) is performed in the following sequence. 1. Marking tools (scriber and measuring ruler) carry out the risks along which the cutting will be carried out. 2. Strip or round metal is placed on a slab or anvil; the cutting edges of the chisel are set at risk with the vertical position of the chisel; the metal is preliminarily cut with a blow of the harmful force of the hammer on the chisel; with strong shoulder blows, they cut the strip to half its thickness (Fig. 43), turn it over and cut it on the other side; set the place of the notch at the edge of the plate 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 out according to Rns. 43. Cutting metal with a wave blow to a template or by geometric construction, then a second risk is applied parallel to the marked contour (at a distance of 1-2 mm from the first risk). 3. To cut the workpiece, the chisel is set obliquely along the second markup risk (Fig. 44.6). After checking the correct position at risk, the chisel is set to a vertical position (Fig. 44, b) and light blows are applied to it with a hammer, moving along the markings. In a similar way, a preliminary notching of the entire contour is performed (Fig. 44, a). After preliminary notching, cutting should be continued with strong shoulder blows from 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 hinged blow, it is necessary to act with both hands", with the right hand accurately and accurately apply strong blows with a hammer to the chisel, and with the left hand move the chisel (in the interval between blows) along the preliminary notch. Each shift of the chisel along the workpiece should not exceed 2/3-% the length of its cutting edge.For the final cutting, it is necessary to turn the workpiece over with the other side (along the noticeable traces of cutting), set the cutting edge of the chisel so that it does not touch the plane of the plate.29 further processing, for the absence of notches, bends of the workpiece obtained during the cutting process. Cutting straight grooves with a crosscut. Cutting straight grooves in metal to a given depth is performed in the following sequence: between the grooves should be no more than 10 mm.) Fig. 44. Cutting blanks with a hanging blow and installing a chisel: o - reception of work; b * - installation with an inclination; c - vertical installation 2. In a vice, the tile is placed in such a way that the risk that determines the depth of the groove is located above the level of the vise jaws by at least 5 mm. Kreuzmeisel should be held in the left hand by the middle part, freely clasping it with all fingers so that the thumb rests on the index finger. The distance from the hand to the impact part of the crosscut must be at least 20-25 mm (Fig. 45, a). 3. The cutting edge of the crosscut is set obliquely at the edge of the tile in the direction of the marks, and at the corners of the tile at the locations of the grooves, oblique chamfers are cut (Fig. 46). One of the main conditions in cutting grooves is the sharpening of the crosscut with undercut, which ensures that the edges of the grooves are clean (see Fig. 45, b). 4. The cutting edge of the crosscut is installed on the plane of the chamfer (see Fig. 45, b), and, striking with a hammer on the impact part of the crosscut, a preliminary groove is cut along the risks to a depth of not more than 1 mm. For convenience, cutting should begin with 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 fine cutting.1 The rest of the grooves are cut in a similar way. Then, applying lighter blows with a hammer on the kreitzmeisel, they perform a final trimming (alignment) of all grooves. The straightness of the sides is checked with a ruler, the depth of the groove - with a measuring ruler. Rice. 45. Cutting out straight grooves with a crosscut: a “I spin the holdings of the crosscut; b "■ sharpening the crosscut about the undercut in *" reception of work, cutting off a layer of metal from wide surfaces. If it is necessary to manually cut a layer of metal from the surface, then a number of grooves are cut through it to the depth of the layer to be removed, and then the resulting protrusions are cut down, and the width of the protrusions must correspond to the length of the cutting edge of the chisel. Cutting off the protrusions is performed in the following sequence. 1. Cast iron tiles with cut grooves are clamped in a vise so that the risk on the side edge is 5 mm higher than the level of the VISE jaws. pi^ 46. Chamfering 2. For convenience, the cutting of protrusions is performed on the right side of the tile. At the edge of the protrusion, the middle part of the cutting edge of the chisel is installed at an angle of 45 ° to the direction of the groove and, striking the chisel with a hammer, the protrusion is cut down to the middle of the tile (Fig. 47). In the same way, the rest of the metal protrusions are cut down, then the tile is turned over 180 ° and the protrusions are cut down from the opposite side, trying to prevent the metal from chipping at the edge of the tile. In order to avoid tearing at the end of the felling, the impact force should be reduced. 3. The entire plane is leveled with a chisel, on which weak blows are applied with a hammer, removing chips no more than 0.5 mm thick. 31 The plane should be relatively smooth and level. Cutting out curvilinear grooves with a crosscut. To lubricate friction surfaces in various machines and mechanisms, it is necessary to make special curved grooves (grooves) with a cross section of various configurations. The operation of cutting out curved grooves with a crosscut requires more accuracy and care compared to the operation of cutting 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. With marking tools (a compass and a measuring ruler), the contours of the grooves are applied to the surface of the tile and they are punched. On the sides, at the exit points of the grooves, a semicircular section is marked. 2. The tile is clamped in a vise so that the groove depth marks are higher than the level of Fig. 47. Cutting off a layer of metal from wide sponges and a 4-8 mm, and one of the planes of the sides (with the grooves out) was facing the worker. In preparation for felling, it is necessary to properly sharpen the crosshead so that the cutting edge is rounded, sharp and consistent with the groove radius. 3. Lateral undercutting of the grooves is performed by filing with a round file to form a bevel to the depth of the grooves near them. 48. Chamfering and cutting out curved grooves of the exit and entrance (Fig. 48). The cutting edge of the crosscut is set on a bevel between the risks, light blows are applied with a hammer on the crosscut, directing it between the risks to apply a groove trace up to 0.5 mm deep. This operation is performed first 32 Fig. 49. Acceptance of work with pneumatic ru- * from one edge of the plate 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 final cutting is about 0.5 mm. Fine cutting is performed from both ends, leveling the existing irregularities and giving the grooves the same depth and roughness. 4. Repeating the techniques for cutting the first groove, sequentially cut through 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. Work with a manual pneumatic chipping hammer. Pneumatic chipping and riveting hammers are used to mechanize cutting, riveting and chasing. Metal cutting with a pneumatic hammer is performed in the following sequence. 1. Before starting work with a pneumatic hammer, study the safety requirements, repeat the general techniques and methods for preparing a pneumatic tool. 2. The hole of the sleeve and the shank of the chisel are wiped clean; check the position of the sleeve, which must be tightly planted in the hole; the chisel is installed in the sleeve with a tight fit. 3. Lubricant is poured through a special hole into the hammer body, the trigger is pressed and the lubricant is injected through the open hole into the internal working parts. 4. Put on gloves and goggles; take a working position; with the right hand they take the handle of the hammer, putting the thumb on the trigger, and with the left hand they hold the body of the hammer (Fig. 49). 5. The cutting edge of the chisel is set 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 to be treated. Cutting is performed only with a sharply sharpened chisel. When transferring a pneumatic hammer, stretching, looping and twisting of the hose must not be allowed. The quality of cutting metal depends on the serviceability and correct sharpening of the cutting tool. The angle of sharpening is chosen depending on the type of metal being processed!64. An example of bending strip metal at an angle Fig. 65. an angle of 90 °; a - angle A * b - angle B of strip metal under Training task /, consisting in bending of strip metal in bends is performed in the following sequence: allowance for bending of the part in two places (Fig. 64) is equal to its thickness (2 mm). 65 4- 2 \u003d 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 set size from the edge The strip is laid on a slab and the workpiece is chopped off with a hinged blow 42 and, if necessary, straightened. muffs so that the risk of bending coincides with the upper plane of the muff. With hammer blows, one shelf of the square is bent (Fig. 65, c), due to which the bent end of the workpiece, tightly adhering to the plane * of the lip, creates an angle A. The workpiece is removed from the vice, measured from the bent end, the size 80 - 2 = 78 mm and applied bending risks for angle B (see Fig. 64). After that, the second end of the workpiece is clamped in a vice and the second shelf of the square is bent with hammer blows (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 vise jaws 44 3. By hammer blows, the end of the strip is bent along the mandrel, achieving a snug 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 by about half the circle with hammer blows. 5. With hammer blows, bend the second end of the strip along the mandrel (Fig. 68, c) until the two planes are in tight contact at the junction. 6. The workpiece is released from the vice, the mandrel is removed and the bending quality is checked with the determination of the diameter using the measuring ruler. Bending of metal of round section with the use of fixtures. Bending of a steel bar of circular cross section on round mandrels (for example, the manufacture of an eyelet with a rod) is carried out in the following sequence. 1. The length of the lug bend is determined by the average diameter (Fig. 69, a), then a distance equal to half the circumference of the ring is measured (put at risk) from the end of the bar. Rice. Fig. 69. Bending of round metal on round mandrels 68. Bending of strip metal on round mandrels d) 2. The workpiece with the mandrel is clamped in a vice so that the outlined risk for the semicircle is at the level of the vise jaws. 3. Hammer blows bend a half ring (Fig. 69, b). 4. The workpiece with the mandrel is rearranged with the reverse side and the second half-ring is bent by blows of a medium-strength hammer (Fig. 69, c). 5. The eye with the mandrel is clamped in a vice and the hammer blows give the rod the correct position with respect to the ring (Fig. 69, d). The quality of bending 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 the bending of pipes at various angles, performed using special devices or on pipe bending machines. Training back / consists in bending a steel pipe with a diameter of 1 "in a cold state with a filler. 1. And prepare two wooden plugs with a diameter equal to the inner diameter of the pipe and a length corresponding to four or five of its diameters. 2. The plug is inserted into one end of the pipe and hammered it with a hammer to a depth of two or three diameters. 3. Fine dry river sand is sifted. The pipe is placed in a vertical position (end with the plug down) and the sifted sand is poured into it. Fig. 71. Acceptance of bending steel pipes Fig. 72 ". Hand bending of steel pipes __ manual pipe bending machine 4. Sand is compacted by tapping with a hammer on the surface of the pipe or by hitting the pipe against a gasket placed on the floor. After the sand is compacted, a wooden plug is hammered into the second end of the pipe (Fig. 70). 5. The place of the bend is marked with chalk. They put on gloves. 6. The bent pipe is inserted into the pipe clamp, between the corner recess of the base and the ledge cracker, and the pipe is clamped by turning the handle. hold down. (When bending welded pipes, the seam must be located outside, and not inside the bends, otherwise the pipe may diverge along the seam.) then, they cover the pipe with both hands and with great effort take it away in the direction of the bend (Fig. 71). To control the end of the bend, a wire template is applied to the center line of the pipe. “8. After the end of the bend, the pipe is released from the clamp, wooden plugs are knocked out and sand is poured out. Pipe bending in a hot state is carried out in a similar sequence. In front of the flexible pipe, the beginning of the bend is marked with chalk, the place of the bend is heated in a furnace or a gas burner to a cherry-red dveta; then the pipe is fixed in the 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 move the bend, the pipe should be cooled with water. Learning task 2 consists in 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 setting the handle to position A (Fig. 72). Rice. 73. Bending pipes from non-ferrous metals: about - in a vice; b-in the roller fixture 2. The beginning of the bend is marked on the pipe with chalk. 3. One end of the pipe is laid between the movable and fixed rollers and into the hole of the clamp so that the marking line on the pipe is aligned with the mark on the surface of the fixed roller. 4. Take the handle with both hands and turn it clockwise to a given angle according to the template. If the effort of the hands is not enough, then in order to increase the shoulder of the application of force, a piece of pipe is put on the handle. The correctness of the bend is checked by a template or by a part (curved pipe). Learning task 3 consists in bending pipes made of non-ferrous metals in the following sequence. 1. A wooden cork is made and hammered into one of the ends of the pipe. 2. Melt the filler (rosin). The vessel must have a spout to drain the molten rosin into the pipe. 3. The pipe is installed vertically (with the stopper down) and rosin is poured into it, leaving the pipe in this position until the rosin has completely hardened. 4. The pipes are bent in one of two ways "a) they are clamped in a vice between the wooden muffs and they are bent by the force of the hands (Fig. 73, a); the bending angle is checked according to the 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 fixed collar. The lever handle is covered with two hands and turned, bending the pipe. 5. The pipe is released from the vice (device), heating it, starting from the open end, along the entire length; rosin is smelted and poured into a vessel. CONTROL QUESTIONS 1. How do you straighten round and sheet metal by hand? 2. How to straighten a steel strip that is bent into an edge with a spiral bend? 3. How to straighten bent angle steel strip with manual screw press? 4. Tell us about the features of straightening hardened parts. 5. How long do you need to take a workpiece to make a ring with a diameter of 200 mm from a round steel bar with a diameter of 8 mm? 6. How are pipes in a cold (hot) state? CUTTING Labor safety requirements. Starting to conduct classes in metal cutting, the instructor of industrial training is obliged to carefully examine all the tools and fixtures. Hand hacksaws that are in use should not be bent, the blade in the hacksaw should be in the same plane and have sufficient tension. The pins for attaching the blade should not have sharp and protruding parts. Wooden handles should be made of hardwood, they should not have cracks and chips.The surface of the handle should be clean and smooth; to prevent splitting, a metal ring should be put on the handle.The handle should be firmly and securely put on the tail of the hacksaw.The tail should enter the handle by a / s -% of their length. Manual scissors for cutting metal should be selected according to the nature of the work performed (straight, curved, right, left). Scissors should be well sharpened and cut without burrs, i.e. not crush the metal being cut. During the work of students the job instructor should pay attention to the installation of round and heavy parts in the vise, as loose parts can easily break out of the vise and cause bruises. When cutting with a hacksaw, the blade must be taut and firmly fixed. Loosely stretched and poorly fastened blades during operation can break and injure the worker. When working on manual lever shears, attention should be paid to the correct supply of material (perpendicular to the knives) and to prevent it from jamming between the knives. When cutting metal with scissors, one should protect one's hands from being injured by the cutting edges of the scissors and burrs on the metal and monitor the position of the fingers of the left hand supporting the sheet from below. 1. When working with a hand-held electrified tool, it is prohibited: a) to work with a faulty power tool (with a faulty electric cable and plug connection); b) perform partial disassembly and repair of power tools; c) work with an electrified tool in damp rooms and outdoors during rain, allow moisture to get inside the power tool, as the case may be energized; d) hold the electrified tool connected to the network by the electric wire, by the cutting tool, press it against the body, put it on your knees; e) leave the power tool connected to the network without supervision during a temporary interruption in operation or a power outage; f) move from one work area to another with the electric motor turned on; g) perform the processing of materials that give rebounding chips without protective glasses; h) allow persons who have not been properly instructed and are not familiar with the requirements of safe work to work with an electrified tool; i) carry out by persons who do not have the right to correct or replace fuses in the electrical network, disassemble the electric motor and the switch of the electrified tool. 2. Work with electrified tools is allowed only with a grounded body of the tool in 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 at the other end to the ground loop. Without the use of protective equipment, it is possible to 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 assemblies and individual parts are tightened sufficiently. 2. Match the mains voltage to the power tool voltage indicated on the plate. The power tool must not 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 securely protect it from mechanical damage by hanging it. 49 4. Check the presence and serviceability of the grounding of the electric tool; ment to the case and the grounding device. 5. Connect the current-carrying cable to the mains and, by turning on the switch, start the power tool at idle for 0.5-] 1 min and check: a) the switch fails to operate; * b) the operation of brushes in commutator motors, where, during normal operation, very little sparking should be observed under the brushes. Starting to conduct training work on a drive hacksaw, the instructor of industrial training is obliged: before starting work, carefully inspect and check the serviceability of the protective > devices of rotating parts, belt drives and the reliability of their fastening; starting devices and distribution devices (knife switches, magnetic starters, push-button stations and other electrical distribution devices), which must have protective casings that exclude contact 1 of the worker with terminals, contacts and other current-carrying parts, as well as protective grounding. The frame of the hacksaw, 1 motor housing, casings of starting and distribution devices must have reliable grounding through a bolted or welded connection. During the operation of the hacksaw, do not clean, wipe ■■ and lubricate moving and rotating parts, transfer re-? go down from step to step with the engine running, blow off sawdust or remove it with your hands (to avoid clogging your eyes or injuring your hands), lean on the machine and put tools, products and other objects on it. When working on a hacksaw, students are prohibited from repairing any equipment. In the event of a malfunction, stop work immediately. The service life, productivity and accuracy of the machine depends on careful and careful care of it. Before starting work, it is necessary to carefully inspect the machine, check its serviceability and, if necessary, lubricate. While working at the workplace, you should maintain order, do not clutter it with unnecessary tools and parts. It is forbidden to leave a working machine unattended; when leaving, even for a short time, the electric motor of the machine should be switched off. After finishing work, remove the tool and clean the machine from chips and dirt with a hair brush or cotton rag. After that, it is necessary to lubricate the working surfaces of the machine with a thin layer of machine oil using a manual oiler and a swab. Work with a manual hacksaw. Performing this exercise, trainees acquire skills in working with a manual hacksaw. The exercise is performed in the following sequence. 1. The blade is inspected, paying attention to the absence of cracks, bends, and also to the set 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 the tension pin, the presence of pins. 2 mm. 4. Install the blade in the slots of the heads so that the teeth are directed away from the handle (Fig. 74). At the same time, the end of the blade is inserted first in the fixed head until the holes match and the position is fixed by laying the pin. Then the second end of the blade is inserted into 5. Tension the blade, screw the wing nut without much effort, without resorting to pliers, a vice and other tools. work tight (with a slight skew) or weak (with increased pressure) the tension of the blade creates another bend during cutting and causes a break.First, a wooden block is cut with a hand saw. Before clamping a wooden block in a vice, risks are applied to it from both sides, which determine the place of cutting. The bar is shifted to the left side so that the line is located at a distance of no more than 30 mm from the edge of the vise jaws. Rice. 74. The 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
FROM WORK EXPERIENCE
Master
production
learning
Aleksandrov Dmitry Gennadievich
working on
individual methodological theme: “Development
practical techniques, skills and abilities in the classroom
educational practice".
Classes of educational practice are held in the educational
workshop in order to form the trainees
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 material
and other conditions, the master p / o outlines who, what and
how much work will be done, sets the total
the number of training and production work per group,
prepares materials, blanks, tools,
accessories - everything you need 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 blanks with the requirements of the drawing, diagram and
technical documentation.
equipment,
Dmitry Gennadievich builds the process
learning so that learners can effectively
perceive and assimilate new, based on previously
learned, and was its continuation and development,
then in the minds of students "bridges are built"
between what they know and can do and what they
to be learned and mastered.
In the process of performing the exercises, the master p / o
constantly encourages students to apply
knowledge, substantiation of the methods being worked out and
ways, he himself gives the necessary explanations,
applies other methods of linking the known,
worked out with what is being studied, worked out on
lesson.
Practical tasks for locksmith practice
(by topic)
markup
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 the bases for metalwork vise.
3. Design and make templates for
various educational and production work in the workshop (according to
student choice).
4. Design a hole marker
fastening the faceplate of a lathe.
5. In a cylindrical part at the same distance from
end you need to drill two holes. How to do
marking the centers of these holes, if, in addition to their distance from
butt, only the length of the arc between them is known?
6. Develop a device that allows you to provide
the correct angle of sharpening a chisel, a cross-cut when cutting
various metals (steel, cast iron, non-ferrous alloys).
7. Design a sheet metal bender
at different angles (in this case, the maximum
thickness and width of the bent metal).
8. Develop a fixture 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
devices production of supports for flowers.
metal cutting
9. To develop such a design of a hacksaw,
which would allow sheet metal cutting
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 markup (the hacksaw blade is not
should lead away from the marking line).
11. Design fixtures for
electric drill, including for cutting sheet
metal and profiles of various sections with a drill.
12. Develop a device that provides accurate
angle of sharpening blades of chair scissors.
filing metal
13. Design such a file handle,
which would not rub calluses on the palms during operation.
14. In a small piece of thin tin, you need to do
square hole with a side of 9 mm. How to do it,
if you have a round file with a diameter of 10 at hand
mm, locksmith workbench with vice, mallet, ruler with
millimeter divisions?
15. Develop such a design of the teeth of the file (in
including removable ones), which would not be clogged with chips when
sawing of viscous metals.
16. Develop such a design of a rotating
file and processing technology that
would allow filing in two planes
simultaneously. In this case, the filing planes should
be the following:
mutually perpendicular;
at an acute angle to each other;
obtuse angles to each other.
Metal drilling
17. Develop a device that allows you to provide
drilling perpendicularity and limit depth
drilling.
18. Develop a device that allows you to provide
the correct angle of sharpening the 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 are angular. How
drill a hole in such material with the correct
forms?
20. The most difficult operation in the manufacture of locksmith
hammer in the workshop is to make in his
preparation of a window under the handle. Usually for this they drill
next to two holes, and then cut out the remaining
jumper. The job can be greatly simplified if
do not cut out the remaining jumper, but drill it out. How
while ensuring that the drill does not come off earlier
drilled hole?
Threading
21. Develop a device that allows you to provide
perpendicularity of the hole axis at the start of cutting
tap threads.
22. In a cylindrical rod with a diameter of 30 mm and a length
50 mm along its axis drilled a hole of 10.1 mm on
depth 36 mm. To a depth of 28 mm in this hole is cut
thread M12. Draw this rod with a
up to half of the screw thread. The shape and size of the screw
choose yourself.
23. Design the cardan joint,
allowing to mechanize deployment (carry out it
using a pneumatic screwdriver).
24. When threading in blind holes due to
heavy loads may break the tap. Suggest
the design of the collar, which would limit the attached
to the force gauge.
25. Can you answer why in mechanical engineering
use hex bolts, and
construction business with a tetrahedral?
Answer: square bolt head and square
the nut is stronger, since when tightening the bolts, their faces are smaller
are crushed by the pressure of the wrench and allow
high tightening forces.
But apply them to
mechanical engineering is inconvenient.
To use a wrench to screw a square nut onto
bolt, it is necessary to turn the key by at least 90 °,
otherwise you will not be able to grab the nut with a wrench for
next turn. In the construction business we meet
with large parts (poles, racks, slopes, etc.),
allowing you to turn the nuts with a wrench to any angle.
But when assembling machines and mechanisms, very often bolts and
nuts are located in places where it is impossible
turn the spanner 90°. In these places
the square nut cannot be tightened with a wrench.
Therefore, hex nuts are used in mechanical engineering.
and hex bolts. This nut or bolt
can be turned by turning the wrench just one
60°, and given that the key handle is rotated relative to
socket by 30°, the hex nut can be
tighten by turning the key only 30° and turning
it for the next nut grip. Further increase
the number of faces of the nuts does not give tangible convenience for their
wrapping, but leads to a decrease in the areas of faces,
makes the angles between the faces more obtuse, and this reduces
their strength. The edges of the nuts will crumple under pressure
wrench.
50 UAH
2018-03-29 00:00:00 - Books and magazines -
Starichkov V.S. "Workshop on metalwork" Edition 4, stereotypical. This manual contains a detailed description of specific working techniques and methods for the practical implementation of basic plumbing operations and types of work in a certain technological sequence. The textbook is intended for industrial training instructors to assist in conducting practical classes in the preparation of locksmiths of various specialties: locksmiths for mechanical assembly work, locksmiths for instrumentation and automation, repairmen, car repairmen and workers of other specialties. 224 pages. Format 60x901/16 Circulation 100,000 copies. Moscow Engineering 1985See my other lots - there are many different books. I combine lots for delivery. Payment-transfer to a Privat Bank card. The buyer pays the commission when replenishing the card. Cash on delivery not to offer Only 100% ADVANCE PAYMENT Shipping paid by the buyer. Kiev - pickup
Topic 1. Introduction 1. INTRODUCTION. ROLE AND TASKS OF THE WORKSHOP ON METAL WORKING IN SPECIAL AND METHODOLOGICAL TRAINING OF FUTURE TEACHERS OF TECHNOLOGY. DEMONSTRATION OF PRODUCTS MANUFACTURED BY STUDENTS DURING THE LESSONS IN THE FITCHWORK WORKSHOP 2. ACQUAINTANCE WITH THE EQUIPMENT OF THE TRAINING WORKSHOP. ORGANIZATION OF THE WORKPLACE OF A LOCKWORKER IN THE TRAINING WORKSHOP, ITS TECHNICAL EQUIPMENT AND MAINTENANCE RULES. 3. INTERNAL RULES DURING WORK IN THE WORKSHOP. BASIC RULES FOR SAFETY AND INDUSTRIAL SANITATION. Study questions:
3 LITERATURE ON THE DISCIPLINE: Basic 1. Pokrovsky B. S. Plumbing: A textbook for the beginning. professional education / B. S. Pokrovsky, V. A. Skakun. - 2nd ed., erased. - M.: Publishing Center "Academy", p. 2. Home locksmith / Comp. A.P. Alekseev. M.: CJSC Tsentrpoligraf, p. 3. Makienko N.I. General plumbing course: Proc. for vocational schools. 3rd ed., rev. M.: Higher. school, with: ill. 4. Makienko N. I. Practical work on plumbing: Proc. allowance for environments, prof.- tech. schools. M.: Higher. school, s, ill. (Professional education. Machining).
4 LITERATURE ON THE DISCIPLINE continued: additional literature 1.Antonov L.P. etc. Practicum in educational workshops. Proc. allowance for students ped. institutes in the specialty "General technical disciplines and labor". M., "Enlightenment", Muravyov E. M. Plumbing: Proc. allowance for students 811 cells. avg. school 2nd ed., revised. and additional M.: Enlightenment, with: ill. 3. Pokrovsky B. S. Fundamentals of plumbing: work. notebook: studies. allowance for the beginning professional education / B. S. Pokrovsky. - M.: Publishing Center "Academy", p. 4. Makienko N. I. Plumbing with the basics of materials science. Textbook for training workers in production. Ed. 5th, revised. M., "Higher. school", p. from ill. 5. Starichkov V. S. Workshop on locksmith work. Proc. allowance for the training of workers in production. 3rd ed., revised. and additional M.: Mashinostroenie, 1983, 220 s, ill. 6. Krupitsky E. I. Plumbing. Ed. 4th, revised. Minsk, "Higher. school", p. from ill. 7. L. Sell. Plumbing in questions and answers / Per. from the 7th Polish. ed. M. E. Lazutina. Ed. G. E-Taurita.K-: Tekhnzha, s. (B-ka worker).
1. INTRODUCTION. ROLE AND TASKS OF THE WORKSHOP ON METAL WORKING IN SPECIAL AND METHODOLOGICAL TRAINING OF FUTURE TEACHERS OF TECHNOLOGY. DEMONSTRATION OF PRODUCTS MADE BY STUDENTS DURING THE LESSONS IN THE LOCTER'S WORKSHOP The main goal of the workshop in educational workshops is to equip students with the knowledge, skills and abilities necessary for the future specialist for the successful implementation at school of an organic combination of labor education and polytechnic education, and, if necessary, initial professional training.
The objectives of the workshop in training workshops: a) teaching students the most efficient use of 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 secondary 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; thicknessing, jointing, turning and sawing machines for wood, as well as the development of all actions associated with sharpening cutting tools manually and on grinding machines);
Continuation of question 1 b) teaching students to choose the most technically and economically feasible methods for manufacturing parts and products in general, finding the most effective technical solutions to particular technological problems (for example, choosing methods for mechanizing the processing of parts, selecting fixtures and tools, types of workpieces, options for technological processes) , i.e., further formation of students' creative attitude to work; c) familiarization of students with the basics of the scientific organization of labor in the processing of structural materials;
Continuation of question 1 d) illustration of methods for teaching 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 methodology of labor training at school, studying the didactics of polytechnic education, and, finally, preparing for directing the technical creativity of schoolchildren.
The peculiarity of these tasks is their clear professional orientation. The future teacher should 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, improving, develop into the working bodies of shaping machines, what is the mechanism of their action and what are the connections of processing operations with physics and other fundamental sciences.
The practical work in the training workshops is built in accordance with the program as a single, but complex module, based on the theoretical and general technical training of students received by them 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 schools. All these works should end with the creation of a well and beautifully designed modern thing (for example, a device, tool, their parts) that is necessary for the production environment, institute or school.
Continuation of question 1 Training in various methods of processing structural materials, developing skills and instilling skills are provided for by examples of the manufacture of the following products: b) tools and devices for replenishing the instrumental economy of the institute's training workshops and transferring them to schools as samples; c) equipment for sports camps and recreation centers for students and high school students; d) models, with the manufacture of which the future leader of circles of technical creativity and high school students will have to meet; e) parts and assemblies ordered by industrial and agricultural enterprises of the production environment of the pedagogical institute.
Continuation of question 1 In the process of completing assignments, future teachers must learn to subordinate their actions in the workshops to certain organizational requirements and labor protection requirements, develop skills of a high work culture at the machine tool and workbench, the ability to work purposefully, proactively and productively. In the course of classes in training workshops, the student must learn to work strictly according to the 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 that is instilled in students throughout the 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. The workshop in training workshops ends with a credit and the assignment of one or two qualification categories (for metal cutting, plumbing or carpentry).
Question 1 continued 1. The purpose and objectives of the discipline: The purpose of the discipline is to develop students' knowledge, skills and abilities of teaching how to work with hand tools, machine tools and technological equipment on the basis of school workshops. Objectives of the discipline: - the study of technological and industrial culture when performing locksmith work in school workshops; - studying the essence of the main types of locksmith work, the tool used, the rules for its selection and use, the sequence of locksmith operations, the methods of their implementation and mechanization of work, safety regulations for locksmith work, requirements for the quality of processing parts, types of tool wear, typical defects, their causes appearance and ways of warning;
Continuation of question 1 - the formation of skills and abilities: choose processing modes taking into account the characteristics of metals and alloys, follow the technological sequence when performing plumbing work: marking, cutting, straightening, bending, cutting and filing metal, scraping, drilling, countersinking, countersinking and reaming holes , threading, riveting, soldering, tinning and gluing; – preparation of students for the use of knowledge and skills of metalworking in professional pedagogical activity.
Continuation of question 1 As a result of studying the discipline, the student must: Know: educational programs and textbooks on metalworking for metalworking; pedagogical technologies necessary for organizing the educational process in an educational institution, extracurricular and extracurricular activities; requirements for equipping and equipping classrooms; subject content in the amount necessary for teaching in basic, senior, including specialized schools; the main types of hand tools, machine tools and technological equipment used in the educational process;
Continuation of question 1 Be able to: apply the main types of hand tools, machines and technological equipment; carry out the main types of work on the maintenance of educational equipment of school workshops; carry out practical work with schoolchildren in the field of metalworking; Own: basic concepts and techniques for the sections of the discipline "Practical locksmith".
Continuation of question 1 The role and place of locksmith work in industrial production The profession of "locksmith" at a modern machine-building enterprise is one of the most common. Each of the locksmith groups is characterized by knowledge and professional skills specific to their work. However, the main base for each locksmith is the possession of general locksmith operations, which are the "frame", "bricks" 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 manual and mechanized tools, which every locksmith should be able to use.
2. FAMILIARIZATION WITH THE EQUIPMENT OF THE TRAINING WORKSHOP. ORGANIZATION OF THE WORKPLACE OF A FITCH IN THE TRAINING WORKSHOP, ITS TECHNICAL EQUIPMENT AND RULES OF MAINTENANCE . Rational, taking into account the requirements of the NOT, the placement of tools, fixtures, as well as the necessary equipment requires dividing them into items of permanent and temporary use and assigning storage places to the tool and fixtures.
Question 2 continued The tool, workpiece and documentation for this work should be placed on the workbench at arm's length. Each item has a strictly defined place. The placement of the tool should ensure a minimum of rotation of 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 tool files, taps, drills, etc. do not deteriorate, and the measuring tool squares, calipers, micrometers, etc. do not deteriorate from nicks, scratches and bumps. After finishing work, the used tools and devices are cleaned of dirt and oil and wiped.
Continuation of 2 questions Technical equipment of the locksmith's workplace Unlike the workplace of a factory locksmith, which is called a section of the workshop with equipment located on it, designed to perform only certain operations, for a student-trainee this is a section of training workshops with a workbench, a vice installed on it, a calibration test and marking plates, a locker or a board on which the most commonly used tool is fixed. The main equipment of the locksmith's workplace is, as a rule, a single workbench with a vice installed on it (Fig. 1.1). The locksmith's workbench must be strong and stable, its height must correspond to the height of the worker.
Continuation of 2 questions Fig. Single locksmith's workbench: 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 - a side from a steel corner; 8 - the handle of the drive for the vertical movement of the vise; b - the location of locksmith tools on a workbench
The most widespread in the performance of metalwork work are the metalwork vice of the following types: chair, parallel (swivel and non-swivel) and high-speed pneumatic vice. Chair vise (Fig. 1.2) are designed to perform heavy work associated with large impact loads, such as cutting, bending, riveting. Rice Chair vise: 1 - workbench; 2 - fastening bar; 3 - fixed sponge; 4 - movable sponge; 5 - clamping screw; b - handle; 7 - flat spring; 8 - rod
Continuation of question 2 Fig. Parallel rotary locksmith vice: 1 - base plate; 2 - turning part; 3 - fixed sponge; 4 - movable sponge; 5 - lead screw nut; 6 - guiding prism; 7 - lead screw; 8 - T-shaped circular groove; 9 - axis; 10 - bolt; 11 - handle; 12 - nut
Continuation of the 2nd question Organization of the workplace There are certain requirements for the placement of tools, blanks and materials in the workplace: only those tools, materials and blanks that are necessary for the performance of this work should be in the workplace; tools and materials that the worker uses frequently should be located closer to him; tools and materials used less often should be located in areas marked with arcs with a radius of approximately 500 mm; tools and materials that are used extremely rarely should be located in distant zones. Their reach is ensured only when the worker's body is tilted.
Continuation of question 2 Fig. Arrangement of convenient and inconvenient zones in the workplace (all dimensions are in millimeters): a, b - on a workbench: 1, A - comfortable; 2, B - less comfortable; 3, B - uncomfortable; c - convenient and inconvenient height reach zones
Rules for the maintenance of the workplace Before starting work, it is necessary: to check the serviceability of the workbench, vise, fixtures, individual lighting and mechanisms used in the work; get acquainted with the instruction or technological map, drawing and technical requirements for the forthcoming work; adjust the height of the vise according to your height; check the availability and condition of tools, materials and workpieces used in the work; place on the workbench tools, blanks, materials and fixtures necessary for work.
During work it is necessary: to have on the workbench only those tools and devices that are currently used (everything else must be in the drawers of the workbench); return the used tool to its original place; Maintain a clean and tidy workplace at all times. Upon completion of work, it is necessary to: clean the tool from chips, wipe it, put it in cases and put it in the drawers of the workbench; clean the countertop of the workbench and vise from chips and dirt; remove unused materials and workpieces, as well as machined parts from the workbench; turn off personal lighting.
3. INTERNAL RULES DURING WORK IN THE WORKSHOP. BASIC RULES FOR SAFETY AND INDUSTRIAL SANITATION General information about labor safety when performing metalwork work, work only with serviceable and sharpened tools; When working on grinding machines, be sure to wear safety goggles or a protective screen with a lock. Avoid beating grinding wheels. Monitor the health of exhaust devices; cutting in a vice is to be carried out only if there is a protective grid or screen on the workbench; work in a headdress and overalls; Only two people can lift heavy parts. Do not put heavy parts on the edge of the workbench; do not blow off the sawdust, do not brush off the chips with your hand, but use a sweeping brush for this;
Continuation 3 questions before starting work on machines and power tools, check them at idle and only then fix the tool; work only in good lighting; when working with electrified tools from a mains voltage of more than 36 V, be sure to use rubber gloves and a rubber mat; work on machines only if there are serviceable guards for moving parts; after working with oils, lubricating liquids, acids, alkalis, soda, fluxes, adhesives, etc., be sure to wash your hands with hot water and soap;
Question 3 continued When receiving minor injuries, be sure to treat the wound with iodine and apply a bandage; work with the use of acids, alkalis, fluxes, etc., as well as work related to the release of dust, smoke, gases, must be performed in a well-ventilated area or under an exhaust hood; do not go out into the draft in a heated state after work; observe all labor safety rules specified in the instructions and technological maps when performing work.
Question 3 continued Industrial sanitation provides for the creation of conditions at work that provide the necessary temperature in production premises, good ventilation, sufficient illumination of workplaces, absence of drafts, availability of auxiliary and amenity premises. Fundamentals 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 work, standing, you need to rest while sitting, and vice versa); sleep at least 8 hours a day; in the process of work from time to time to change the working position; after the end of the working day, wash the whole body in the shower with soap.
Ministry of Education and Science of the Samara Region
State budget educational institution
secondary vocational education
Zhiguli State College
Guidelines
for the implementation of practical work
by discipline: plumbing
for students I course
profession: 190629.08 Construction machinery repairman
2015
APPROVED
Subject (cycle)
commission
technological profile
Protocol No. ____________
dated “___” ______________ 201_
Chairman
G.S. Soldatenkova
Compiled in accordance with the requirements of the Federal State Standard NPO by profession 190629.08 Locksmith for the repair of construction machines
Deputy Director for
educational work
S.Yu. Sorokin
“___” ______________ 201_
APPROVED
at the NMC meeting
Protocol No. ____
dated ___________ 201__
Contains a description of all the practical work performed by studentsIcourse in the study of discipline"Plumbing".
General requirements for the performance of all practical work and recommended literature are given in the introductory part of these guidelines.
Compiled by:
Moshkina Elena Alexandrovna - teacher of special
disciplines GBOU SPO "ZhGK"
Reviewers:
Soldatenkova Galina Sergeevna - teacher of special
disciplines GBOU SPO "ZhGK"
Content
Introduction
General instructions for the implementation of practical work
The procedure for performing practical work and submitting a report
Safety regulations and basic requirements for labor protection when performing practical work
Practical work No. 1 "Measurements with calipers ШЦ-1, ШЦ-2"
Practical work No. 2 "Measurements with micrometers of various types"
Practical work No. 3« Measurements with templates, probes and goniometers»
Practical work No. 4 "Measurements on the indicator stand, indicator inside gauge and depth gauge"
Criteria for evaluation
INTRODUCTION
Practical classes are an integral part of the discipline "Plumbing".
This collection of descriptions of practical work contains topics, tasks and guidelines for self-preparation of the student to perform practical work, consolidating the material covered and testing knowledge.
The task of the collection is to determine the content, form and procedure for performing practical exercises.
In the process of preparing for practical classes, the student must review the material covered on the topic of the lecture, study the recommended additional scientific, technical and methodological literature.
The collection contains the thematic name of practical work, 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 form of reporting are outlined. At the end of each topic there are control questions to consolidate the acquired knowledge and skills.
At the end of the collection is a bibliographic list of recommended literature.
GENERAL INSTRUCTIONS FOR PERFORMANCE
PRACTICAL WORKS
Practical work is carried out after studying the theoretical material of the relevant topics.
Before starting the task, carefully, thoughtfully read this manual in order to be sure to understand the essence of the work.
The implementation of each practical work consists of the following steps:
independent preparation of students;
check by the teacher of readiness of students to carry out practical work;
implementation of practical work;
organizational and technical maintenance of the workplace, preparation of the report and protection of the results of work.
PROCEDURE
PRACTICAL WORKS AND REPORTING
The topics and sequence of practical work are determined by the course program and are reported by the teacher at the first lesson of the group.
Practical work is carried out in accordance with the schedule of training sessions. The work of students 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 of educational and methodological manuals.
Reports are issued for all practical work. The report on practical work is compiled by each student independently.
All reports are carried out in one specially designated notebook. The report is carried out during the practical session and, if necessary, is drawn up through independent work. The completed report will be submitted to the next session.
At the beginning of each report, the topic of the work is indicated, the purpose and summary are given.
The total credit for practical work is given 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 REGULATIONS AND BASIC REQUIREMENTS OF LABOR PROTECTION DURING THE PERFORMANCE OF PRACTICAL WORKS
Before starting practical work, students should familiarize themselves with these rules. Each student who has been instructed in safety precautions must sign in the journal, students who have not been instructed and who have not signed in the journal are not allowed to perform practical work.
Students are prohibited from:
take parts, devices out of the laboratory or bring in foreign objects, smoke, make noise;
walk unnecessarily around the laboratory during classes or approach other workplaces, arbitrarily disassemble or operate cuts, models or other equipment, if this is not provided for by the practical work performed;
lean on posters or fold parts on them, write on tables, stain their surface, leave paper and garbage;
perform actions with devices and other equipment that are contrary to safety regulations.
PRACTICAL WORK #1
Topic: "Measurements with calipers ШЦ-1, ШЦ-2"
Goal of the work : to study the devices, the purpose of calipers, their preparation for measurements and methods of measuring and reading readings.
Work order
Exercise 1. Measurement with a caliper ШЦ-1
Familiarize yourself with the caliper device:
study all parts and their purpose (Fig. 1);
to master the device of the vernier caliper (Fig. 2): the length of the vernier 19 mm 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. Caliper:
1 - rod; 2,7 - sponges; 3 - movable frame; 4 - clamp; 5 – vernier scale; 6 – depth gauge ruler
Rice. 2. Nonius
Prepare the caliper for work:
check the completeness of the tool;
wash the instrument in aviation gasoline, wipe it dry with a soft linen cloth, wipe the measuring surfaces especially carefully.
Perform an external inspection:
sponges and the end of the rod must be in perfect order;
on the measuring surfaces there should be no traces of corrosion, nicks, scratches, blunt sharp ends of the sponges or other defects that affect the accuracy of the measurement;
the strokes and numbers of the scales must be distinct and even;
check the interaction of individual parts of the caliper, the smooth running of the frame 3 , jaw parallelism 2 And 7 , whether there is a skew, tight movement of the frame engine.
Check the zero position of the caliper:
bring the contact of the sponge of the caliper (Fig. 3, A). The jaws must be parallel throughout. There should be no gap at the edges of the sponges. The zero stroke of the vernier must coincide with the zero risk of the main scale;
Rice. 3. Checking the zero position of the caliper
the size of the gap between the measuring surfaces of the wretched calipers is estimated in daylight “by eye” (Fig. 3, b). In the absence of a gap between the jaws for external measurements or with a small gap (no more than 6 mm), the zero strokes of the vernier should coincide with the initial stroke of the main scale (Fig. 3, A);
if the tool is not adjusted, then the actual reading of the tool must be corrected accordingly, equal to the initial error, but with the opposite sign;
in case of a large discrepancy between the zero strokes, it is necessary to depress the screws of the vernier, move the vernier plate until the strokes coincide and fix it with screws.
Measurement methods:
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 to be checked, avoiding distortion of the jaws and achieving a normal measuring force;
Rice. 4. Taking measurements with a caliper ShTs-1
fix the frame with the thumb and forefinger of the right hand, holding the barbell with the rest of the fingers of this hand. At the same time, the left hand should hold the rod sponge (Fig. 4, b).
Reading the readings of the ShTs-1 caliper:
when reading the testimony, keep 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, consequently, to 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 bar scale from left to right with a zero stroke of the vernier.
Fractional values (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 coinciding with the stroke of the rod.
Rice. 5. Reading caliper readings
EXAMPLE. The zero stroke coincided with the 39th division on the bar, and the vernier at zero pressure showed the 7th division. The measurement result will be: 39 + 0.1x7 \u003d 39.7 mm.
Exercise 2. Measurement with a caliper ШЦ-II
Familiarize yourself with the design of the ShTs-II caliper (Fig. 6, A).
Rice. 6. Caliper ШЦ- II :
– fixed measuring jaw 2 - movable measuring sponge, 3 - movable frame, 4 - frame clamp, 5 - micrometer feed frame, 6 - micro feed frame clamp, 7 - rod with millimeter divisions, 8 - micro feed screw, 9 - frame feed nut, 10 - vernier
To study the vernier device: 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), which is 0.05 mm less than the whole number.
Complete tasks (see exercise 1, paragraphs 2 and 3).
Check the interaction of the individual parts of the caliper:
smooth running of the frame, parallelism of the jaws, is there any skew, backlash in the micrometer pair, tight movement of the frame slider, weakening and displacement of the spring located under the locking screw;
whether there is any wear on the working surfaces of the scale of the ruler and the frame, causing the measuring surfaces of the jaws to skew, inaccurate strokes on the scale and vernier.
Check zero position:
check the coincidence of the zero stroke of the vernier 10 with zero division (stroke) rods 7 . For rough frame measurements 3 move along the bar until the jaws fit snugly. Use a micrometric feed to accurately set the caliper. 8 , 9 ;
in the absence of a gap between the jaws for external measurements or with a large gap (no more than 3 microns), the zero strokes of the rod and the vernier with the shifted jaws must match. The position of the scale of the caliper and vernier caliper ShTs-II with a reference value of 0.05 mm is shown in fig. 7.
Rice. 7. Reading the readings of the ShTs-caliper II
Methods of measurement with a caliper ShTs-II:
set an approximately controlled size (for external measurement fig. 8, A a little more, and with the internal fig. 8, b somewhat smaller than the controlled size). Fix the micrometer feed frame 2 ;
take the caliper with your right hand, and with your left hand support the rod sponge or part (if small);
right hand, fixing the engine 2 with microfeed nut 3 , smoothly move the frame 1 so that the sponges are in contact with the surface to be checked, fix the frame, avoiding distortion and achieving normal force;
Rice. 8. Techniques for measuring with a caliper ShTs- II
install the caliper so that the part - the measuring 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. Installing the caliper Fig. 10. Installing the caliper
when measuring outside surfaces when measuring inside surfaces
Reading the readings of the ShTs-II caliper:
keep the caliper straight in front of your eyes (Fig. 5);
count an integer number of millimeters from left to right with a zero stroke of the vernier;
find the stroke of the vernier, coinciding with the stroke of the bar scale. To the nearest left figure, denoting hundredths of a millimeter, add the results of multiplying the reading value by the serial number of the short vernier stroke, which coincides with the stroke of the rod, counting it from the long digitized stroke. Examples are shown in fig. eleven, a, b;
Rice. 11. Examples of reading during measurements:
a, b– external surfaces, V– internal
for internal measurement (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 scales of the caliper.
Answer:
Answer:
Answer:
Control questions:
Name the universal measuring tools 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 Nonius?
What determines the accuracy of sizing?
PRACTICAL WORK № 2
Topic: "Measurements with micrometers of various types"
Goal of the work: to study the design, overlay and measurement techniques with micrometers.
Types of micrometers:
MK- smooth micrometers for measuring the outer dimensions of products;
ML- sheet micrometers with a dial for measuring the thickness of sheets and tapes;
MT- pipe micrometers for measuring the thickness of the walls of pipes;
MOH- gear micrometers for measuring gears.
Micrometers type MK are designed to measure external dimensions. They are issued with limits of measurements: 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 setting measures 8 (Fig. 12). Micrometers with an upper measurement limit of more than 300 mm have movable anvils, providing the ability to measure any size within a given micrometer.
Work order
Exercise 1. Measurement with a micrometer MK
To study the design of the micrometer MK (Fig. 12, A).
Rice. 12. Micrometer MK:
A- device, b- micrometer screw, V- drum; 1 - bracket, 2 - heel, 3 - screw 4 - stopper 5 - stem 6 - drum, 7 - ratchet, 8 - setting measure
Familiarize yourself with the device and the 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 plotted;
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 along the circumference into 50 equal parts (vernier in Fig. 12, V);
per turn micrometer screw 3 moves along the axis by the thread pitch (Fig. 12, b). When turned one notch, the micrometer screw 3 , connected to the drum 6, moves along the axis by 1/50 of the step, i.e. 0.5:50=0.01 mm, which is the division price of a micrometer.
Setting the zero position of the vernier (Fig. 13):
check the zero position of the micrometer before measuring: a properly adjusted micrometer has a heel 2 and screw 3 (see fig. 12) must be in contact with the measuring surfaces of the setting standard 8 or directly between each other (with a diameter measurement range of 0 - 25 mm), and the zero stroke of the drum must coincide with the longitudinal stroke of the stem, while the bevel of the drum must open the zero stroke of the stem (Fig. 13, A);
Rice. 13. Setting the zero position of the micrometer MK
if the strokes do not match, the micrometer should be adjusted:
lock the micrometer screw 3 with reduced measuring planes;
loosen the cap 2 , connecting the drum with a microscopic screw, holding the belt with your left hand 1 (Fig. 13, b);
release the drum from the clutch with the screw and turn it until the zero stroke on the drum bevel coincides with the longitudinal stroke of the stem (Fig. 13, A);
fix the drum on the screw with the cap.
Measurement with a micrometer MK:
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 checked;
take a micrometer (Fig. 14, V) with the left hand on the brace 1 (in the middle), and the measured part 3 put between the heel 2 and the end of the micrometer screw 4 ;
gently rotate the ratchet with the fingers of the right hand 5 , lightly press the end of the micrometer screw 4 detail 3 to the heel 2 until it touches the surface of the part being checked, while the ratchet 5 will not start to turn and click;
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 a micrometer MK:
a, b– cleaning of working parts, V- accepting the installation of a micrometer, G– measuring line
Reading micrometer readings:
when reading the readings, keep the micrometer directly in front of your eyes (Fig. 15, A);
count an integer number of millimeters on the lower scale, half a millimeter on the upper scale of the stem, and count hundredths of a millimeter on the divisions of the drum scale, along the stroke that coincided with the longitudinal risk on the sleeve;
in fig. 15, b examples of readings are given.
Rice. 15. Working with a micrometer:
A- Reading statements b– counting examples
Control questions:
How should measuring instruments be handled?
What are the tools and devices for accurate measurements?
Why should the accuracy of the measuring tool be higher than the accuracy of the part being tested with this tool?
PRACTICAL WORK № 3
Topic: "Measuring with templates, probes and goniometers"
Goal of the work: to study the design of templates, probes and goniometric tools, methods of measurement with goniometers and the rules for reading readings.
Sample(German Schablone, from French echantillon - sample) in technology, a fixture or tool for checking the correctness of the shape of a number of finished products; a sample according to which homogeneous products are made.
Template types:
Radius Pattern- a tool for controlling 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). Radius of curvature 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. Set of thread templates
1 - convex; 2 - concave
Thread template- a tool for determining the pitch and angle of the profile of machine parts and other products. 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 to be checked so that its teeth enter the thread cavities. Correspondence of the pitch and angle of the thread profile with the pitch and angle of the template profile are determined by the "clearance" or by the tightness of the edges of the template to the thread.
Measuring probe used to control the gap between surfaces. It looks like a plate of a certain thickness. Measuring probes are made from 0.02 to 1 mm thick. Their main dimensions are standardized. They are produced in the form of sets of plates (Fig. 18) of different thicknesses in one holder. They are used separately or in various combinations.
Rice. 18. Set of probes (all dimensions are in millimeters):
L- probe length; S– probe thickness
Types of goniometers:
UN- for measuring external angles from 0 to 180 0 and internal angles from 40 - 180 0 ; with a vernier reference value of 2 / (Fig. 19);
MIND– for measuring external angles from 0 to 180 0 with a vernier reading of 2 / (minutes).
Rice. 19. Universal goniometer
Work order
Exercise 1: Measuring gaps with a feeler gauge
Before measuring gaps with a feeler gauge, make sure that the feeler blades move smoothly.
If the movement of the plates in the gap is difficult, then they should be lightly lubricated.
The size of the gap is determined by the total value of the set of probe plates that are completely included in the gap along its entire length.
When measuring the gap, do not apply much force to the probe in order to avoid breakage of the plates or their deformation.
Exercise 2: Preparing for a measurement
Familiarize yourself with the design of the goniometer UN (Fig. 20).
Rice. 20. Goniometer UN
Nonius device: the angle between the extreme strokes of the vernier is 290 and is divided into 30 parts, but unlike the goniometer, the UM is built on an arc of a larger radius, therefore, the distance between the strokes is greater, which makes it easier to read the readings (Fig. 20, b).
Installation of a goniometer for measuring angles:
if a square and a ruler are installed on the goniometer (Fig. 21, a), then angles from 0 to 500 can be measured;
if you remove the square and fix the 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 a square (Fig. 21, d), angles from 230 to 3200 can be measured.
Rice. 21. Installation of a goniometer for measuring angles
Preparing the goniometer for work:
before using the goniometer, it must be thoroughly wiped;
check the condition of the goniometer by external inspection: for scratches, signs of corrosion; clarity of strokes of the scale and vernier;
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 goniometer.
Measurement methods:
put the goniometer on the part to be checked so that the ruler is aligned with the sides of the measured angle;
with the right hand, slightly pressing the base ruler against the measuring surface, move the part gradually, reducing the clearance until it is in full contact;
if there is no clearance, fix the position with a stopper and read the reading.
Reading the readings of the goniometer UN:
Measurement of external corners (Fig. 22, a - e):
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, the 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, e).
Rice. 22. Measurement of external angles with goniometer UN
a - receiving a check, reading readings, b - from 0 to 500, c - from 50 to 900,
d - from 90 to 1400, e - from 140 to 1800
Measurement of 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. Measurement of internal angles with goniometer UN
A- receiving checks, reading testimonies, 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 by measuring angular values or by setting a given angle is checked on a degree scale and vernier.
On a degree scale, placed on the arc of the base, determine at which integer division (or between them) the zero division of the vernier stopped, which corresponds to the number of integer degrees of angular magnitude.
vernier scale determine which of its divisions coincided with the division of the degree scale, using the numbers of the vernier determine the number of minutes, which is multiplied by 2 (the accuracy of the goniometer reading).
Example. The zero stroke of the vernier passed the 34th division of the base scale, but did not reach the 35th; / .
Control questions
What is a square, and in what plumbing operations is it used?
Name the patterns commonly used by a locksmith.
PRACTICAL WORK №4
Topic: "Measurements on the indicator stand, indicator inside gauge and depth gauge"
Goal of the work : to study the design, purpose, methods of measurement and readings of the indicator readings.
Indicator types:
sentry type A) with measurement intervals: from 0 to 5 mm; from 0 to 10 mm and small-sized - from 0 to 2 mm.
End with the movement of the measuring rod 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; to measure the horizontal and vertical position of the planes of individual parts, ovality, taper of shafts, cylinders; beats of gears, pulleys, spindles and other rotating parts.
Work order
Exercise 1
Familiarize yourself with the design of the ICH indicator (Fig. 24, a).
Rice. 24. HI indicator:
A- clock type: 1 - square, 2 - holders 3 - nonius, 4 - screw nut, 5 - stopper 6 - semicircular base 7 - sector, 8 - base line 9 - removable ruler;
b- end, V– indicator scheme
The indicator scheme is given in fig. 24, V: 1 – measuring rod with teeth on one side, 2 – indicator housing, 3 - a small gear wheel on the same axis as the arrow, 4 - a large gear drive wheel relative to the gear wheel 3, 5 - spring 6 - a small gear wheel (leading), sitting on the same axis with the gear wheel 4 and engaged with the teeth of the rod rack 1 , 7 - arrow, 8 - clock face; 9 - spring.
The indicator scale is given in fig. 24, A: The 3 indicator dial is divided into 100 equal parts. The price of each division is 0.01 mm.
small dial 6 (Fig. 24, b) with divisions for reading full revolutions. For one complete revolution, the hand 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 the extreme position, while the indicator needle should give a constant reading.
The indicator has very thin small gears, axles, springs, which must be protected from shocks, shocks in order 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 the corrugated rim 4 or turn your head 11 (when the dial is stationary), set the bezel relative to the arrow, fix it with a stopper 2 .
measuring tip 9 with removable ball 10 bring into contact with the surface of the plate (Fig. 25, A) or setting measures 9 block of tiles, fig. 25, b). Set the arrow against any division of the scale. Further readings are carried out from this indication, as from the initial one.
Rice. 25. Setting the indicator to zero position: A- on the plate, b- end measures
Exercise 4. Techniques for checking the indicator
Install a precisely checked part (Fig. 26, A).
Install the indicator on a tripod (Fig. 26, A).
The working surface of the measuring rod of the indicator 1 bring into contact with the surface of the part to be tested 2 so that the arrow makes one or two turns (Fig. 26, b).
Note the initial position of the arrow 5 (see fig. 24, A) and pointer 6 on the dial. The countdown is carried out from this indication, as from the initial one.
Move the measuring rod of the indicator relative to the surface of the measured part or the measured surface relative to the indicator (Fig. 26, a, b).
Rice. 26. Techniques for checking the indicator:
A– movement of the tested part, b– by moving the indicator
Exercise 5
Whole numbers of millimeters are counted with an arrow 6 (see fig. 24, A), hundredths of a millimeter count on a large scale 3 .
Control questions
What is the purpose of measuring indicators?
What are calipers and calipers, what are they, where are they used?
Criteria for evaluation
For a correctly completed report, with the answer to all control questions, a mark of five points is set.
If there are minor errors (spelling errors, inaccurate work done), the total 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 is designed for 10 minutes. One point is awarded for each correct answer.
Makienko N.I. Practical work on plumbing: Proc. allowance for prof. tech. schools. – M.: 1982. – 208 p.
Pokrovsky B.S. General plumbing course: Proc. allowance. - M .: JIC "Academy", 2007 - 80 p.
Pokrovsky B.S. Locksmith basics. Workbook. - M .: JIC "Academy", 2008.
Pokrovsky B.S. Plumbing Fundamentals: A Textbook for the Beginnings. prof. education. - M .: JIC "Academy", 2007. - 272 p.
Pokrovsky B.S., Skakun V.A. Plumbing: An Album of Posters. - M .: JIC "Academy", 2005. - 30 pcs.
