What are the reasons for the uneven surface of the stamping parts and the concave arc surface? How to solve it?

What are the reasons for the uneven surface of the stamping part and the concave arc surface? How to solve it? The reasons for the uneven arc surface of the stamping part are mainly as follows: 1) In ordinary stamping, the blank is initially exposed to the punch When pressure is applied, it will produce elastic warpage and produce a concave arc surface under the punch. If the gap is moderate and the shearing is carried out in time, the elastic warpage will be basically eliminated. When the gap is too large, the blank will be severely bent and stretched at the cutting edge, the shearing will be delayed, the warpage will not be eliminated, and it will be left on the stamping part to become a concave arc surface. When the interlayer film is too small, because the size of the stamping part that falls into the cavity of the cavity is slightly larger than the size of the hole, the workpiece is squeezed and warped, forming a concave arc surface. The method of elimination is to set an edge holding device (such as an elastic discharge plate) and an elastic ejector device on the stamping die to suppress elastic warpage. When the gap is small, trimming the stamping gap can eliminate the concave arc surface of the workpiece. 2) The straight wall section of the cavity of the cavity has a reverse taper or the contact area of u200bu200bthe ejector plate and the workpiece is small, resulting in a concave arc surface of the workpiece. The method of elimination is to repair the back taper of the cavity wall of the cavity and replace the top plate. 3) When the shape of the stamping part is complicated, the unevenness of the punching force around the workpiece will cause the workpiece to warp unevenly. The way to eliminate it is to increase the blank holder force. 4) When there is oil, air or debris between the die and the stamping parts, it will also cause the stamping parts to flex, especially for thin and soft workpieces. The way to eliminate it is to pay attention to strengthening the cleaning work, and design vent holes on the die when there is air. Previous post: What is the impact of the loosening of metal stamping die pins on the stamping parts? What is the reason for the loosening of the pins?