There are many reasons for wrinkling in the process of drawing automobile parts

2019-11-01 16:56:19

It is an effective and useful method to adjust and control the deformation resistance by setting Drawbead on the pressing surface. The drawbead can adjust the flow of material well, make the flow resistance of each part of the material in the drawing process even, make the amount of material flowing into the cavity fit for the needs of the workpiece, and prevent the phenomenon of more wrinkling and less cracking.

For the drawing parts with complex curved surface, especially the drawing parts with small flange, the draw bead should be set to improve the radial tensile stress of the drawing to control the wrinkling; the draw bead should be set on the part with small radial tensile stress, that is, the part where the sheet metal is easy to flow. For the parts with small flange, in order to set the drawbead, some materials (process supplementary materials) can be added appropriately, and this part can be removed during trimming. For drawing parts with large difference in drawing depth, the drawbead should be set at the part with less feed, so that the excessive material in this part can be organized to draw into the cavity of the die, so as to prevent wrinkling.

There are many reasons for wrinkling in the process of drawing. The main reasons are as follows:

(1) the drawing depth of automobile parts is too deep, which causes the sheet metal to flow too fast and form wrinkling in the process of feeding.

(2) the R angle of the die is too large during the drawing process of the stamping part, which causes the punch unable to hold the material during the drawing process, resulting in the sheet material flowing too fast and forming wrinkles.

(3) the pressing bar of stamping parts is unreasonable, too small and the position is not correct, which can not effectively prevent the sheet material from flowing too fast and forming wrinkling.

(4) the pressure of the ejector pin is too small, so that the stamping parts are not completely formed and wrinkled.

(5) the unreasonable design of die positioning results in that the stamping parts cannot be pressed during the drawing process or the pressing edge is too small, resulting in that the stamping parts cannot be pressed during the drawing process, causing wrinkling.

(6) the gap between the convex die and the concave die is too large to press the material during the drawing process, resulting in wrinkling.

The above are the common causes of wrinkling in the drawing process of metal car stamping parts. In the specific problems, specific analysis is needed to find the specific reasons according to the specific situation of stamping parts The way to prevent wrinkling is to ensure that the die can hold the material during the drawing process of the metal stamping parts and ensure a reasonable flow speed of the plate. On the other hand, if the sheet flow is too slow, it can cause the stamping parts to crack.