Why do automotive metal stamping parts cause tearing?
Why do automotive metal stampings cause tearing? The quality of stamped products will lay a solid foundation for the appearance and performance of the vehicle. Therefore, the quality assurance of stamping parts has always been a problem that automobile manufacturers attach great importance to. In this article, the editor of Zhejiang Balford Electromechanical shares the reasons for the tearing of automotive metal stamping parts.
The stamping process of common tearing and skewing of metal stamping parts is: blanking punching – punching incision – flanging forming – incision – flanging. There are many forms of tearing and skewing of the intermediate protective bracket during the forming process. The tearing parts are mainly distributed in the hole shape of the part, the junction of the R arc and the wall neck at the corner of the side wall, etc. Different, the proportion of each fracture site is different. The tear can be a one-time forming tear or a tear caused by a fatigue crack, i.e. invisible crack development.
Analysis of the reasons, according to the actual situation on site, by checking the tearing position, fracture shape and crushing degree of the parts, it is believed that the tearing and skewing behavior of the parts is mainly reflected in the flanging forming process, and the reasons for this process phenomenon are as follows:
The molding process parameters were not implemented correctly. In the forming process of the part, the process requires that the die, the pressing material core and the parts of the two must be closely attached together, and the forming is realized by the plastic deformation of the pressing plate when the machine tool slides down. However, due to the unstable quality of the pressed parts, it means that the pressure of the machine tool is in a state of unbalanced pressing during the production process. The main reason is that the processing technicians did not adjust the machine tool pressure in time according to the requirements of the process regulations at this stage, or did not communicate with each other about the stability of the machine tool pressure during the handover process. Every shift changes, resulting in poor and unstable parts quality.
The common design defects of flanging forming molds for left/right parts with one mold and two cavities, in addition to flanging, also have shape forming content, and the finished parts are particularly complex, the bending surface is narrow, and the forming requirements of the concave mold core are consistent with the forming surface, resulting in The mold structure has a large forming stroke and a small pressing area. In the initial mold design, the designer only considered the small feature of the pressing surface, while ignoring the guiding sliding of the pressing core forming