Special metal stamping parts, bending parts-hardware

What should I do if the bottom of the bent part of special metal stamping parts is uneven and bulged? The bottom of common U-shaped metal stamping and bending parts sometimes has uneven and bulging bottoms. So what should we do if this happens? Most of these factors are caused by the fact that at the end of the bending process of metal stamping parts, the top plate is not used, but only the bottom of the die is used for pressing. When U-shaped punching and bending are performed without using the top plate, from the beginning of the punching to the final forming, the sheet metal and the bottom of the punch are punched without tightly fitting. In this way, it is impossible to make the material completely plastically deformed, and the bottom of the U-shaped stamping part is often bulged. 1. When the punch of the metal stamping parts starts to press down and just touches the sheet, the sheet is bent under the pressure exerted by the convex and concave horizontal fillet, and the sheet is bulged away from the top surface of the punch. 2. When the punch of the metal stamping part enters the die and continues to be bent, although the sheet material is bent under the action of the corners of the die, the initial bulge is formed under the punch. Because there is no pressing of the top plate, no obvious changes occur. 3. The punch of the metal stamping part is pressed to the bottom, that is, the final stage of the bending process. The bulging part is flattened by the convex and the bottom of the female mold, and the workpiece is flattened when the bending is completed and the workpiece is taken out of the stamping die. The bulging part is recovered due to the rebound, leaving the bottom of the uneven and bulging bending deformation remaining. Do you understand the above introduction of the hardware author? Need more detailed understanding, welcome to consult: