Avrutin S.V. Milling (1963). Milling for secondary vocational schools Collection of programs for milling

Fedor Alekseevich Barbashov

Textbook for secondary vocational schools

"Library Series"

Publishing house "Higher School" 1975

To build a communist society, it is necessary to solve the main economic task - to create the material and technical base of communism.

The creation of the material and technical base of communism presupposes high rates of growth of industrial production, while the main share of the increase in industrial output should be ensured by increasing labor productivity.

Increasing labor productivity is one of the most important tasks facing socialist industry, the solution of which must be inextricably linked with reducing costs and reducing the labor intensity of manufactured products. The most important condition for increasing labor productivity is technological progress.

The directives of the XXIV Congress of the CPSU provide for rapid growth in the production of metalworking machines with numerical control, with an increase in their output by 1975 of no less than 3.5 times. It is also planned to expand the production of high and especially high precision machines, automatic and semi-automatic lines.

The national economy's need for skilled workers is continuously increasing, therefore, the Directives of the 24th Congress of the CPSU provide for the training of at least 9 million skilled workers in vocational educational institutions for all sectors of the national economy over the next five years. One of the forms of training for industry is also the training of young workers directly in production.

In a speech at the XVII Congress of the All-Union Leninist Communist Youth Union, L. I. Brezhnev said on the issue of preparing the work shift: “It is necessary, first of all, that the bulk of it be trained in vocational educational institutions so that even before entering work, young people people got a specialty.”

The network of vocational schools will be significantly expanded, the graduates of which will receive a general secondary education along with a profession. By the end of this five-year period the number of such schools will double.

Increasing the efficiency of social production and its intensification is the main line of economic development of the country in the coming years and in the long term, as the primary condition for creating the material and technical base of communism and increasing the people's well-being.

It is currently important to introduce advanced technology, high-performance equipment and cutting tools, as well as modern forms of organization and management into production.

The sequence of presentation and content of the book's material correspond to the training program for milling operators in secondary vocational schools, approved by the State Committee of the USSR Council of Ministers for Vocational Education.

Book title: Milling
Edition: Moscow

Year of printing: 1963
Number of pages: 538
Format: Djvu

The book provides basic information about milling, milling machines, tools and devices; Much attention is paid to progressive milling technology, issues of mechanization of processing processes, organization and economics of production are highlighted. The book is intended as a textbook for students of vocational schools and can be used for training and advanced training of workers in production. The fifth edition of the book has been revised in accordance with the requirements of the curriculum and programs for training milling operators in urban vocational schools. This publication contains the necessary clarifications caused by the modernization of milling machines, the release of new standards for milling cutters and the introduction of general machine-building standards for cutting modes for milling work.

Material on tolerances and fits, on the designs and use of measuring instruments was removed from the book, since according to the new curriculum this information is included in a separate course \"Tolerances and technical measurements\". The author tried to present the educational material in the most accessible form for students and at the level of the current state of technology, linking the scientific foundations of milling with the advanced experience of innovative milling operators, and also set out to present the basic prerequisites and basic information on the mechanization and automation of milling work in order to prepare the student to master the special course \"Fundamentals of mechanization and automation of production\", provided for by the curriculum for training milling operators in vocational schools. A large place in the book is occupied by processing examples, arranged in increasing degrees of complexity and selected in such a way as to cover the entire range of milling operations provided for in the industrial training program.

The first examples of processing, which introduce the beginner to the basic techniques of controlling, setting up and setting up the machine, are presented in more detail than the subsequent ones in order to maximally ensure the development of the initial operations that serve as the basis for subsequent ones. In conclusion, material is provided for independent development of the technological process of milling operations and for selecting cutting modes taking into account maximum productivity. In the process of preparing this publication, the author took into account all the valuable advice and comments received from employees of educational institutions of the vocational education system and readers of the book. In preparing this publication, the author partially revised chapters XI \"Elementary information about the technological process\" and XXX \"Technological process of processing parts on milling machines\", written by a teacher at vocational school No. 40 (Moscow), engineer. B.I. Obshadko for previous editions of the book.

The author recommends that when taking the course \"Milling\" you use educational films \"Basic information about milling metals\" (parts 1 and 2) released in 1958 and 1959, \"Basic information about milling machines\", \"Console- milling machines of the first range\", \"Cantilever milling machines of the second and third range\", \"Longitudinal milling machines\", \"Widely universal machines\", \"Continuous action machines\" produced in 1961, \ "Methods of copy milling of flat contours and complex surfaces\" and \"Copy milling machines with tracking systems\" produced in 1962 by the Kyiv Film Studio of Popular Science Films. The attention that was given to previous editions of the textbook, as well as the positive assessment from organizations in charge of training workers, allows the author to hope that this edition of the textbook, intended for the vocational education of young people going into production after graduating from an eight-year school, will contribute improving the quality of training of young qualified milling operators.

§ 1. GENERAL CONCEPTS ABOUT MILLING

Milling is one of the cutting processing methods. It is carried out using a multi-bladed tool called a milling cutter.

When rotating, the cutter cuts its teeth into the workpiece advancing on it, fixed on the machine table, and with each tooth cuts off chips from its surface, giving the workpiece the shape and dimensions specified in the drawing.

Depending on the location of the teeth relative to the surface being processed, there are different types: cylindrical (Fig. 1, a) and end mills (Fig. 1, b). All other types of cutters - slotted disk (Fig. 1, c), three-sided disk (Fig. I, d), cut-off (Fig. 1, d) and terminal (Fig. 1, e) - can be conditionally considered as one of these two main types.

The rotation of the cutter around its axis is calledthe main movement,and the forward movement of the workpiece is feed movement. Both of these movements are carried out by a milling machine.

The main movement, i.e. rotation of the cutter, is determined by the number of revolutions of the machine spindle per minute (rpm) and characterizes the cutting speed. The feed movement is characterized by the amount of minute movement of the machine table with the workpiece mounted on it relative to the cutter. This value is expressed in millimeters per minute(mm/min).

Milling is a very productive process of machining by cutting, so it has become widely used relatively quickly.

Milling has become especially widespread with the development of large-scale and mass production, since it makes it possible to process large quantities of identical parts with a given accuracy at a low cost of working time.

The development of milling and the widespread use of milling have in turn led to a number of improvements in milling tools and milling machines, as a result of which labor productivity is continuously increasing and the quality of work performed is improving.

There is not a single branch of mechanical engineering, from the production of precision instruments to the construction of the largest hydraulic turbines, where milling is not used to process parts.

Rice. 1. Main types of cutters:

a - cylindrical; b - end; c - grooved; G — three-sided disk; d — cutting (slotted); e - end

Milling machines are produced by a number of domestic enterprises: Gorky, Odessa and Dmitrov milling machine plants, Ulyanovsk Heavy Engineering Plant, Zalgiris plant in Vilnius, etc.

§ 2. QUALIFICATION CHARACTERISTICS OF THE MILLING OPERATOR

1st class

The qualification characteristics of a 1st category milling operator according to the new qualification directory correspond to the 3rd category of the previous directory; it is given in the program

for individual and team training of milling operators, published by Trudrezervizdat in 1959.

During the training, the milling operator must also learn advanced work techniques, namely: high-speed milling methods, working with multi-location devices, with prefabricated and shaped cutters, multi-machine maintenance methods, etc.

Having received this knowledge, the milling operator must constantly improve his skills in production, carefully studying the work performed and constantly monitoring the technical literature on milling.

CUTTERS

§ 18. BASIC INFORMATION ABOUT CUTTING TOOLS

Processing methods. In mechanical engineering, many different materials are used: alloys of ferrous and non-ferrous metals, plastics, wood, etc. Workpieces made from these materials, depending on their purpose, must be given the required shape and dimensions, which can be obtained in the process processing. There are two processing methods:

A) machining without removing chips:casting, forging, hot and cold stamping, pressing, etc.;

b) processing with chip removal,i.e. mechanical processing on lathes, milling, planing, drilling and other machines.

The workpiece must have allowance, i.e., a layer of material that is cut off during machining in order to obtain the required shape and dimensions of the part, as well as the quality of its surface.

In machining by cutting, the stock is removed from the workpiece using cutting tools. Depending on the type of processing, cutting tools differ from each other in design. However, all these numerous designs are created on the basis of a turning or planing cutter of a conventional shape by increasing the number of cutting edges, changing its profile or changing its main angles. The operating principle for all cutting tools is exactly the same.

The simplest chisel and its work. The cutting part of each cutting tool is shaped like a wedge. Under the influence of the force applied to the cutter, the tip of the wedge goes deeper into the material being processed, breaks the adhesion of its particles and moves the separated layer to the side.

In Fig. 44, a shows a simple cutter cutting into a workpiece to remove allowance.

The sharper the wedge, i.e., the smaller the angle formed by its sides, the less force is required to insert it into the material. So, the sharper the knife, the easier it cuts. The angle formed by the sides of the wedge is calledpoint angleand are designated by a Greek letter (beta). Consequently, the smaller the taper angle β, the easier the cutter penetrates the material, and, conversely, the larger the taper angle β, the greater the force that must be applied to cut the material.

You should consider what material needs to be cut. If you cut hard material with a tool that has a small sharpening angle p, then the thin blade will not hold up and will crumble or break. Therefore, depending on the hardness of the metals to be cut, the corresponding sharpening angle of the cutter is assigned.

Under the influence of force R (Fig. 44.6) the front surface of the cutter will compress the layer of the material being processed and, overcoming the internal forces of adhesion of the material particles, break a piece of it, and then take it upward. This piece is calledchip element.The cutter, moving further under the action of the applied force, will again compress and then chip (crack) the next elements of the chip and, thus, remove a layer of material, i.e., cut.

From the author
Introduction
Section one. Basic information about milling
Chapter I: Milling Basics
§ 1. Concept of the process of metal cutting
§ 2. The concept of milling
Chapter II. Milling machine and its components
§ 3. Types of milling machines
§ 4. Main components of cantilever milling machines
§ 5. Control of a cantilever milling machine
§ 6. Machine care
Chapter III. General information about cutters
§ 7. Elements of the cutter
§ 8. Basic information about the design of cutters
§ 9. Securing cutters on the machine
Chapter IV. Basic concepts of cutting theory
§ 10. Cutting elements during milling
§ 11. The process of chip formation
§ 12. Operation of cutters
Chapter V. The simplest devices for securing workpieces
§ 13. Securing workpieces on the flock table
§ 14. Fastening workpieces in corner plates and prisms
§ 15. Securing workpieces in a vice
§ 16. Securing workpieces in special clamping devices
Chapter VI Industrial sanitation and safety
§ 17. What a young milling operator should know about industrial sanitation
§ 18. Safety rules when working on a milling machine
§ 19. First aid in case of accidents
§ 20. Production instructions for safety and fire prevention measures
Section two. The simplest milling work
Chapter VII. Plane milling
§ 21. Milling cutter in the cutting process
§ 22. Milling a plane with a cylindrical cutter
§ 23. Milling a plane with an end mill
§ 24. Milling of mating planes
§ 25. Milling inclined planes and bevels
§ 26. High-performance methods for milling planes
§ 27. Rules for milling with cylindrical and end mills
Chapter VIII. Milling of shoulders, rectangular slots and grooves. Cutting work
§ 28. Milling ledges and grooves
§ 29. Milling keyways in shafts
§ 30. Cutting work
Chapter IX. Milling of shaped grooves and special grooves
§ 31. Milling of shaped grooves
§ 32. Milling special grooves
Chapter X. Milling curved contours and shaped surfaces
§ 33. Milling curved contours
§ 34. Milling of shaped surfaces
Section three. Basics of the milling process
Chapter XI. Basic information about the technological process
§ 35. Basic concepts about the technological process
§ 36. Contents and form of the operational card
Chapter XII. Machining accuracy and surface quality during milling
§ 37. Reasons affecting milling error
§ 38. Methods for assessing processing inaccuracy
§ 39. Accuracy of geometric shape
§ 40. Surface quality
Chapter XIII. Selecting a mounting base when securing workpieces
§ 41. Basic information about databases
§ 42. Examples of basing blanks
Section four. Milling work using a dividing head
Chapter XIV. Dividing heads
§ 43. Simplified dividing heads
§ 44. Universal dividing heads
Chapter XV. Direct division milling
§ 45. Milling polyhedra
§ 46. Milling of end grooves and splines
Chapter XVI. Milling using the simple division method
§ 47. Division without using a dividing disk
§ 48. Division using a dividing disk
Chapter XVII. Differential milling
§ 49. The essence of the differential division method
§ 50. Design of the universal dividing head UDG-135
§ 51. Features of the design of the universal dividing head UDG-160
§ 52. Accessories for the universal dividing head for differential division
§ 53. Practice of differential division
Chapter XVIII. Milling of spur gears
§ 54. Basic information about gearing
§ 55. Milling of gears
Chapter XIX. Complex types of milling
§ 56. Milling grooves on a cone
§ 57. End milling
§ 58. Dividing the workpiece around the circumference into unequal parts
Chapter XX. Helical groove milling
§ 59. General information about the helix
§ 60. Practice of milling helical grooves
Section five. Milling machine design
Chapter XXI. Basic information about milling machines
§ 61. Main types of domestic milling machines
§ 62. Kinematic diagrams of machines
Chapter XXII. Cantilever milling machines
§ 63. Milling machines 6N81; 6N81G and 6N11
§ 64. Milling machines 6M82; 6M82G and 6M12P
§ 65. Milling machines 6M83; 6M83G and 6M13P
§ 66. Modifications of cantilever milling machines of the second and third sizes
Chapter XXIII. Copy milling machines
§ 67. Classification of copy-milling machines
§ 68. Copy-milling machines without a tracking system
§ 69. Copy-milling machines with a tracking system
Chapter XXIV. Operation of milling machines
§ 70. Modernization and adaptation of machines for productive milling
§ 71. Checking the accuracy of milling machines
§ 72. Operation of milling machines
Section six. Fundamentals of cutting theory in milling
Chapter XXV. Milling forces
§ 73. Elements of the cut layer
§ 74. Cross section and volume of the cut layer
§ 75. Forces during milling
Chapter XXVI. Power required for milling
§ 76. Power when milling
§ 77. Passport of the milling machine
Chapter XXVII Selecting the cutting mode when milling
§ 78. Conditions determining the choice of cutting mode
§ 79. Selecting cutting mode
Chapter XXVIII. Rational operation of cutters
§ 80. Operation and sharpening of cutters
§ 81. Control of sharpening of cutters
Section seven. Basics of rational work of a milling operator
Chapter XXIX. Information about the organization and economics of labor
§ 82. Organizational and technical maintenance of the workplace
§ 83. The concept of labor organization
§ 84. Basic information about cost accounting
Chapter XXX. Technological process of processing parts on milling machines
§ 85. Principles of constructing a technological process
§ 86. Example of drawing up a process map
§ 87. Ways to reduce the total time when milling
Applications
Literature