What are the causes of surface quality problems of automotive stamping parts?

2021-04-23 15:32:17

According to the actual situation of the site, through the inspection of the tearing position, fracture morphology and extrusion degree of the parts, it is considered that the tearing and skewing behavior of the parts is mainly reflected in the flanging forming process, and the causes of this process are as follows:

1. The forming process parameters are not implemented in place. In the forming process, the process requires that the die, the die and the bixu of the two parts closely fit together. When the slide of the machine tool slides down, the plastic deformation of the sheet metal is compressed to realize the forming. But now, because the quality of the pressed parts is unstable, it shows that the pressure of the machine tool is in the state of unbalanced pressure jump in the production process. The main reason is that the processing technicians did not adjust the pressure of the machine tool in time according to the specified requirements of the process, or did not communicate with each other about the pressure stability information of the machine tool during the handover of each shift, which led to the instability of the quality of the parts.

2. The first mock exam for flanging forming die is the one with two chambers. The left and right parts are common. Because the process is not only flanging, it also has shape forming contents, especially the parts are complex, the bending surface is narrow, forming requires the die material to match the forming face, which results in the large forming stroke and small pressing area. In the design of the initial die of Zui, the designer only considered the characteristic of small pressing surface, but ignored the guide sliding stroke of the pressing core.

There are many reasons for the surface quality problems of metal automobile stamping parts. The surface quality of coil, sheet and die will affect the quality of final stamping parts. The operation in the stamping process and the loading and unloading of station equipment may also damage the surface quality of parts. Therefore, the details should be fully considered in every link of the whole manufacturing process, Try to avoid quality problems that affect the appearance of Zui final products.

Stamping parts in the progressive die, through punching stamping parts peripheral residual material method, to form the shape of stamping parts. The main reason of turning over and twisting is the influence of blanking force. During blanking, due to the existence of blanking clearance, the material is stretched on one side of the die (the material warps upward) and compressed on the other side of the punch. When the discharge plate is used, the material is compressed by the discharge plate to prevent the material on the die side from warping upward. At this time, the stress condition of the material changes accordingly. With the increase of the pressure on the discharge plate, the material near the punch side is stretched (the compression force tends to decrease), while the material on the die surface is compressed (the tension force tends to decrease). The turnover of stamping parts is caused by the material on the die surface being stretched.