During the stamping process, mechanical motion runs through the entire process. The implementation of various stamping processes has its basic motion mechanism, which is closely related to the mold. The structural and mechanical design of various molds is ultimately to meet the requirements of their ability to achieve specific movements. Whether the designed mold can strictly complete the movements required to achieve the stamping process directly affects the quality of the stamping parts. Therefore, mechanical motion should be controlled in mold design. At the same time, in order to meet the requirements of product shape and size, it should not be limited to various basic motion modes of the process, but should continue to develop and innovate, and flexibly apply mechanical motion in mold design.

2 Stamping process

2.1 Introduction to stamping process

Stamping is a forming and processing method that relies on a press and mold to apply external forces to plates, strips, pipes, and profiles, causing plastic deformation or separation, in order to obtain the required shape and size of workpieces (stamped parts). Stamping and forging both belong to plastic processing (also known as pressure processing), collectively known as forging and stamping. The billets used for stamping are mainly hot-rolled and cold-rolled steel plates and strips. Among the world's steel products, 60% to 70% are plates, most of which are finished products made through stamping. The body, chassis, fuel tank, radiator plates of automobiles, boiler drums, container shells, motors, electrical appliances, and iron core silicon steel sheets are all stamped and processed. In products such as instruments, household appliances, bicycles, office machinery, and household utensils, there are also a large number of stamped parts. Compared with castings and forgings, stamped parts have the characteristics of being thin, uniform, light, and strong. Stamping can produce workpieces with reinforcing ribs, ribs, undulations, or flanges that are difficult to manufacture by other methods to improve their rigidity. Due to the use of molds, the accuracy of the workpiece can reach the micrometer level, and it can be repeated with consistent specifications, such as punching holes, protrusions, etc.

Cold stamped parts generally do not undergo cutting or require only a small amount of cutting. The precision and surface state of hot stamping parts are lower than those of cold stamping parts, but they are still better than castings and forgings, and the cutting amount is less. Stamping is a production method that uses composite molds, especially multi-station progressive molds, to complete multiple stamping processes on a single press, achieving fully automatic production from strip uncoiling, leveling, punching to forming and finishing. Production, good labor conditions, low production costs, typically producing hundreds of pieces per minute.

22 Types of stamping processes

Stamping is mainly classified by process, which can be divided into two categories: separation process and forming process. The separation process, also known as punching, aims to separate the stamped parts from the sheet along the contour line, while also separating the quality requirements of the cross-section. The purpose of the forming process is to cause plastic deformation of the sheet metal without breaking the billet, and to produce the required shape and size of the workpiece. In actual production, it is often a combination of multiple processes applied to a workpiece. Punching, bending, shearing, deep drawing, bulging, spinning, and straightening are several main stamping processes. The surface and internal properties of stamping materials have a significant impact on the quality of stamping products, requiring the thickness and uniformity of stamping materials; The surface is smooth and clean, without scars, scratches, surface cracks, etc; Uniform yield strength without obvious directionality; High uniform elongation; Low yield strength ratio; Low work hardening.

Control and Application of Mechanical Motion in 3 Punching Dies

Basic operation of punching process