Process innovation and process scheme design stage for metal stamping parts, cha

（1） Innovation approach for stamping process of automotive chassis: 1. Optimization of process combination. Based on the completion of a stamping part, there are often multiple processes in the process, so multiple processes are combined or a single process is combined as much as possible. When the size of the stamping part is too small, the production of composite molds or continuous molds should be selected. 2. Design Measures for Manufacturing Molds for Automotive Stamping Parts (1) Determination of Mold Structure Form and Type for Hardware Stamping Parts; After the establishment of the process plan, the single die, compound die and continuous die can be selected by simple operation, which is mainly reflected in the unity of stamping for different dies in multiple processes. The positioning surface should be based on no deformation or movement, and flange positioning should be selected for different shapes of parts. (2) As a key link in car body manufacturing, the manufacturing process quality of automotive stamping parts is directly related to the actual profits of enterprises through modular body technology. Therefore, improving the body design and process design to achieve efficiency and cost reduction is the current core development trend. The modular technology of the vehicle body has improved the adaptability of the production line, and the application of platform based and modular methods has been enhanced. The stamping process design in stamping dies is a typical innovative design process. Especially the introduction of KBE technology will be a way for innovative design of stamping dies. In the stage of workpiece design, it is necessary to analyze the processing characteristics of the workpiece, formulate the mold type, basic process parameters, and continuously develop the process plan. In the stage of using stamping dies, the first step is to carry out product stamping activities, and then take corresponding measures to solve problems that arise during different periods of use. In the stamping stage, apply the methods and systems of innovative design to the stamping process design. Especially in the digitalization and intelligent design of stamping dies, a combination of manual and computer methods is first used to manually complete processes such as product drawing development, process design and strip layout, and concave die layout. Secondly, according to the stamping requirements of the parts, the stroke of the slider, the speed curve of the slider, the holding time of the bottom dead center, the nominal pressure, etc. can be programmed arbitrarily, making the mold processing technology have the characteristics of high service life. （2） During the stamping process design stage, the stamping process design can be carried out solely based on the product data of the parts, enabling the parts to be processed and formed. The process scheme for stamping the car door collision beam can be designed as: drawing+trimming and punching. This process design scheme does not pay attention to the requirements of part tolerances, and there is no relevant precision scheme. There is a risk that the accuracy of local parts cannot meet the usage requirements (such as the welding matching surface between the collision beam and the door outer panel), which affects the lap matching during the welding of the white body. In order to ensure that the precision of the parts after processing can meet the precision requirements of the welding assembly and the white body, based on the size and tolerance of the parts and the requirements of the reference positioning system (RPS) drawing, the scheme of local tolerances and positioning methods of the parts is reflected in the process design. The process scheme is optimized as: drawing+trimming punching+, with the requirement of the contour of the overlapping surface of the parts. During stamping processing, the accuracy level of hole positioning is higher than that of shape positioning, so in metal stamping parts; When designing the process plan, try to use hole positioning as much as possible, and maintain consistency in the positioning points between each stamping process to avoid cumulative errors caused by the conversion of positioning benchmarks. In addition, in the manufacturing process of pushing from low-level sub assemblies to sub assemblies from stamped parts → sub assemblies → large sub assemblies → white body, the RPs should be unified in the upper and lower sequence, so that the point positioning pins and main positioning surfaces are inherited step by step; Low unused locating pins and main locating surfaces cannot appear on high sub assemblies. Reduce cumulative errors by inheriting the main positioning points between welding processes. Therefore, unifying the RP8 points in the upper and lower sequences, while maintaining consistency in the positioning benchmarks between stamping molds, part gauges, and welding fixtures, is also one of the basic principles for improving detection accuracy and reducing the accumulation of errors in white body. It should be strictly followed when stamping molds and welding fixtures.