Punching, Cutting and Bending Die

Contents

Introduction

Part Description and Assignment

Rationale for Process Selection

Billet Calculation for Stamping

Material Cut

Material Utilization Factor

Routing technology of part manufacturing

Stamping transitions

Calculation of process forces and deformation operation

Equipment selection and short description

Workplace Organization

Stamp diagram

Determination of die pressure center

Calculation of actuating dimensions of the working tool

Selecting Materials for Forming Die Parts

Calculation of die parts for strength

Calculation and description of mechanization tools operation

Safety precautions

Calculation of cost-effectiveness of the process

List of Used Sources

Applications

Part Description and Assignment

The specified part "Bracket" is made of sheet material with thickness a = 1 mm. The part is made in the form of an angle. As a result of bending, two surfaces were obtained: the first surface with dimensions of 12x22 mm, having a rectangular groove of 8x10 mm and the second surface, combining a rectangle of 14x22 mm and a semicircle with a radius of R8 mm. Concentric with a semicircle is a hole for fixing a part with a diameter of 6 mm. According to the design of this part, it can be concluded that it belongs to the type of fasteners for fixing, as well as increasing the stiffness of angular joints. This bracket is made of Steel 20, which indicates the need for reliable fastening of the walls.

Introduction

Cold sheet stamping is one of the most advanced technological methods of production; it has a number of advantages over other types of metal processing, both technically and economically.

Technically, cold stamping allows:

to obtain parts of very complex shapes which are otherwise difficult or impossible to manufacture;

to create strong and rigid, but lightweight structures of parts, with a small material consumption;

to obtain interchangeable parts with sufficiently high dimension accuracy.

Economically, cold stamping has the following advantages:

economical use of the material and relatively small waste;

very high capacity of equipment using mechanization and automation of production processes;

mass production and low cost of manufactured parts.

Sheet stamping, or stamping of sheet material, is a widespread and very progressive form of metal forming technology. Using sheet material (strip, tape, sheet) as the initial workpiece, a large range of a wide variety of flat and spatial parts can be produced by sheet stamping.

Sheet stamping is used in all industries related to the manufacture of metal parts.

It is especially used in such industries as automotive, tractor and aircraft engineering, in the defense industry, in the manufacture of household items.

Among the advantages of sheet stamping, which ensure its increasing use in industry, are the following:

The possibility of manufacturing parts with a minimum metal capacity that cannot be obtained by other methods of metalworking.

High accuracy of stamped parts ensuring their interchangeability.

Good surface quality of the stamped parts (under cold stamping conditions), which, along with their accuracy, allows to completely eliminate or minimize cutting.

Relatively high labor productivity even with manual feeding of blanks.

Comparative simplicity of mechanization and automation of sheet stamping processes.

Adaptability to scale of production.

Relatively small metal waste.

Possibility of obtaining different and optimal mechanical properties in different sections of parts obtained by stamping.

Some of the noted advantages of sheet stamping are due to the fact that the forming of the workpiece is carried out by plastic deformation, and a significant part of the workpiece undergoes simultaneous deformation. Cold forging, characterized by deformation of the preform without preheating, is usually accompanied by strengthening of the metal, while the surface quality, as a rule, does not deteriorate, but can even improve compared to the surface quality of the initial sheet preform.

Cold sheet stamping combines a large number of various operations that can be systematized according to technological characteristics. By the nature of deformation, cold stamping is divided into two main groups: deformation with material separation and plastic deformation.

The first group combines deformations, which lead to local separation of the material, by cutting and separating one part of it from another. Group of plastic deformations of cold forging includes operations to change shape of bent and hollow sheet parts.

There are four main types of deformations of cold sheet stamping:

cutting - separation of one part of material from the other along closed or open contour;

bending - turning a flat blank into a curved part;

drawing - transformation of a flat blank into a hollow part of any shape;

moulding - changing the shape of a part or workpiece by local deformations of various types.

Each of the main types of deformation of cold forging is divided into a number of separate specific operations, characterized by the peculiarity and purpose of the work, as well as the type of die. In addition to stamping operations, in cold stamping, procurement, pressure-rolling, auxiliary, thermal and finishing operations are used.

The technological processes of sheet stamping can be divided into operations, the alternating use of which makes it possible to give the initial flat blank the shape and size of the part specified for manufacture.

Such die designs and technical means have been developed that allow the successful use of sheet stamping not only in mass and large-scale, but also in serial and small-scale production. All this contributes to the successful use of sheet stamping in all areas of metalworking.

The technology of sheet stamping and the design of the stamping tool are established depending on the size and shape of the stamped part, the accuracy of stamping, as well as on the seriousness of production. In mass and large-scale production, high automation of processes, as well as complex expensive dies, justify themselves, since the cost of producing dies per unit of stamped product is very small and slightly affects the total cost of production. In small-scale production, and sometimes in serial, experimental, cold sheet stamping in the case of the use of conventional die structures is economically unprofitable.

Sheet stamping production is easily mechanized and automated and is currently developing towards the development and implementation of new technological processes and the widespread use of mechanization and automation tools.

The introduction of new processes is characteristic of small-scale production and production with an often changing nomenclature of products in which the use of conventional tool dies is economically impractical.

The main progressive technological factor for the further development of cold stamping is the desire to obtain a fully finished part by stamping, which does not require further cutting.

The greatest effect from the use of cold stamping can be achieved by comprehensively solving technical issues in all stages of production preparation, starting from the creation of technological structures or shapes of parts that allow them to be economically manufactured. In recent years, labour productivity has increased significantly as a result of full or partial mechanization, automation of production, as well as progressive and high-speed stamping methods.