Quality Improvement Measures for Stamping Parts Production Process Stage

[1] In the production process stage of stamping parts, it can be seen that the material utilization rate of the open stretching process is significantly higher than that of the closed stretching process. 2. The use of material cutting technology can improve material utilization for stamping parts with complex shapes and high single piece waste. As shown in Figure 2, the use of material cutting technology has improved material utilization. 3. The use of the left and right part merging process in automotive body stamping is mostly symmetrical. When designing the process, it is important to consider the design of the left and right part merging. This not only reduces process supplementation and improves material utilization, but also reduces mold manufacturing costs and stamping costs. In addition, some metal stamping parts; The method of the first mock examination with multiple parts can also be used, that is, a pair of molds can produce multiple identical parts at a time. This method has the same effect as the double left and right parts, and can improve the utilization rate of materials by reducing the process supplement. The material utilization rate of the double slot process of the door inner plate is estimated to be 59.38%, and the utilization rate of materials increases to 69.45% by using the combined process. 4. There are two ways to reuse waste materials: direct reuse of waste materials and reuse of large waste materials. The waste generated during the cutting of skylight installation panels can be used to manufacture other parts of the same material and thickness as these panels, reducing material costs. If collected during the production process, other materials and small parts with the same thickness can be reused to improve the material utilization rate of the entire vehicle. [2] Stamping process can be divided into two categories: separation process and forming process. The separation process includes cutting, punching, trimming, etc., while the forming process includes stretching, bending, flanging, etc. Propose detailed preventive measures and solutions for possible wrinkling, cracking, and rebound defects in each process. 1. The fundamental reason for wrinkling defects is that the sheet metal is subjected to compression, and when the primary and secondary stresses in the plane direction reach a certain level, the thickness direction becomes unstable. According to the different causes of wrinkle formation, it can be divided into two types. The first type is caused by excessive material entering the cavity, resulting in material accumulation and wrinkling; The wrinkling is caused by instability in the thickness direction of the sheet metal or uneven tensile stress. To address this defect, the specific solution is as follows: (1) From a product design perspective: minimize the height of the flange as much as possible; Connect the areas of drastic changes in shape in a smooth state; For areas of the product that are prone to wrinkling, suction molding can be appropriately added; (2) Starting from the design of stamping process: increase the edge pressure and control the feeding speed; Add circular or square drawing ribs to the process supplement; Add forming processes within a reasonable range; (3) For the selection of stamping materials: While meeting product performance requirements, for some parts that are prone to wrinkling, materials with good formability should be selected. 2. The fundamental reason for the formation of cracking defects is that during the stretching process of the material, the strain exceeds it, and the obvious manifestation is the visible cracks on the surface of the workpiece. It can usually be divided into three types: first, it is caused by insufficient tensile strength of the material, and the cause of fracture is generally due to excessive local stress at the rounded corners of the convex and concave molds; The cracking is caused by insufficient deformation of the material, such as cracking at the sharp point; The third type is cracks caused by impurities in the material. Therefore, in order to prevent fracture defects, the fundamental measure is to reduce stress concentration. The specific plan is as follows: (1) Choose a reasonable billet size and shape; (2) Adjust the parameters of the drawstring to prevent cracking caused by excessive swelling force; (3) Increase process incisions, ensure reasonable material flow, and achieve uniform deformation; (4) Lubrication conditions, reducing friction and increasing feed rate; (5) Reduce the edge pressure or use variable edge pressure to control the feeding resistance; (6) Using materials with good ductility and formability to reduce cracks. 3. The vast majority of stamped parts will produce rebound defects, and the fundamental reason for rebound can be summarized as follows: after the part is deformed by stamping, the material is loaded due to elasticity, resulting in local or overall deformation. Stamping materials, pressure levels, and mold conditions can all affect springback. For rebound defects, the solution is as follows (1) Compensation method, which is based on the metal stamping parts after bending and forming; The magnitude of the rebound amount is determined by making a slope on the mold equal to the rebound amount of the workpiece in advance to compensate for the rebound after the workpiece is formed. The magnitude of the rebound amount to be compensated in this method is mainly determined based on manual experience estimation or CAE numerical simulation analysis results; (2) Bending method: Apply tension while bending the sheet metal to make the stress distribution inside the sheet metal more uniform, thereby reducing the amount of rebound; (3) Local compression method: Transforming the deformation zone into a stress state of triaxial compression, fundamentally changing the properties of elastic deformation; (4) By locally reinforcing and other methods to increase stiffness, the stiffness of stamped parts can be improved and deformation reduced.