As shown in table 1- 1.
Table 1- 1 Schematic diagram of separation process name Application scope of process characteristics The blanking die cuts the sheet along the closed line, and the punched part is the workpiece. Stamping dies used to manufacture flat parts of various shapes punch plates along closed lines, and the punched parts are waste products. It is used to cut holes on stamping plates or molded parts. The cutting line is not closed with scissors or dies. It is mostly used to cut the edges of flat parts with simple shapes, and the redundant materials at the edges of workpieces are stamped out by dies. It is mainly used for stamping parts with three-dimensional shapes, punching long and narrow grooves on plates or parts with shapes, and cutting the punched semi-finished products into two or more parts. Mostly used after asymmetric double printing or group printing. 2. Forming process: the blank is plastically deformed without being damaged, and the required shape and dimensional accuracy are formed.
As shown in table 1-2.
Table 1-2 The name of the forming process is simple, and the process characteristics are simple. The bending die is used to bend the metal plate into a part with a certain angle, or to bend the bent part again. The die used for deep drawing presses the metal plate into a hollow part with any shape, or the hollow part is further deformed and flanged. The mold is used to turn the outer edge of the hole or metal plate into a straight wall. The die is used to apply an outward radial force to the hollow part, so as to enlarge the local diameter. The necking die applies radial pressure from outside to inside to the mouth of the hollow part to reduce the local diameter. Extrusion puts the blank into the mold cavity and extrudes it to extrude it from the gap of the mold, thus forming a hollow or solid part. The end of the plate is rolled into a nearly closed round head to process parts similar to hinges. A deformation method for expanding the radial dimension of a hollow blank or a tubular blank at a specific position. Correction will flatten the uneven surface of the workpiece; Compared with other machining and plastic processing methods, stamping has many unique advantages in technology and economy. The main performance is as follows.
(1) The stamping production efficiency is high, the operation is convenient, and it is easy to realize mechanization and automation. This is because stamping depends on stamping die and stamping equipment to complete the processing. The number of strokes of an ordinary press can reach dozens of times per minute, and the high-speed pressure can reach hundreds or even thousands of times per minute. Every stroke of stamping may be punched.
(2) During stamping, because the die ensures the accuracy of the size and shape of the stamping parts, it generally does not damage the surface quality of the stamping parts, and the die life is generally long, the stamping quality is stable, the interchangeability is good, and it has the characteristics of "identical".
(3) Parts with large size range and complex shapes can be processed by stamping, such as stopwatches as small as clocks and watches, as large as automobile longitudinal beams and panels. In addition, the cold deformation hardening effect of materials in the stamping process makes the stamping strength and stiffness higher.
(4) Stamping generally does not produce chips and waste materials, requires less materials, and does not need other heating equipment. It is a material-saving and energy-saving processing method, and the cost of stamping parts is low. Because stamping has such advantages, stamping is widely used in all fields of national economy. For example, aerospace, aviation, military industry, machinery, agricultural machinery, electronics, information, railways, posts and telecommunications, transportation, chemical industry, medical equipment, household appliances, light industry and other industries all have stamping processes. Not only is it used in the whole industry, but everyone is directly related to stamping products. There are many large, medium and small stamping parts on airplanes, trains, cars and tractors. Body, frame and rim are all stamped. According to relevant survey statistics, 80% of bicycles, sewing machines and watches are stamped parts; 90% of televisions, tape recorders and cameras are stamped parts; There are also food metal cans, steel boilers, porcelain bowls and stainless steel tableware, all of which are products stamped with molds; Even the hardware of the computer needs stamping parts.
However, the dies used in stamping are generally special, sometimes a complex part needs several sets of dies to be processed and formed, and the dies have high manufacturing accuracy and high technical requirements, so they are technology-intensive products. Therefore, only mass production of stamping parts can fully reflect the advantages of stamping and obtain better economic benefits.
Of course, there are also some problems and shortcomings in stamping. Mainly manifested in the noise and vibration produced by stamping, and the safety accidents of operators occur from time to time. However, these problems are not entirely due to the stamping process and the die itself, but mainly due to the traditional stamping equipment and backward manual operation. With the progress of science and technology, especially the development of computer technology and electromechanical integration technology, these problems will be solved as soon as possible. (1) designed stamping parts must meet the product use and technical performance, and be easy to assemble and maintain.
(2) The designed stamping parts must be conducive to improving the utilization rate of metal materials, reducing the varieties and specifications of materials and reducing the consumption of materials as much as possible. If possible, use low-priced materials, so as not to waste stamping parts as much as possible.
(3) The designed stamping parts must be simple in shape and reasonable in structure, so as to simplify the die structure and the number of processes, that is, the whole part is processed with the least and simplest stamping process, and the use of other methods is reduced, which is beneficial to stamping operation, organization and realization of mechanized and automated production, thus improving labor productivity.
(4) Under the condition of normal use, the designed stamping parts should be as low as possible in dimensional accuracy grade and surface roughness grade, which is beneficial to product interchange, reduce waste products and ensure stable product quality.
(5) The designed stamping parts should be as beneficial as possible to use the existing equipment, process equipment and process flow for processing and to prolong the service life of the stamping die.