The three elements of sheet metal stamping: reasonable stamping technology, advanced molds, and efficient stamping equipment. Stamping die is special process equipment for processing materials into parts (or semi-finished products) in stamping processing. The following is an introduction to common defects and their causes in the sheet metal stamping process.
1. Blanking, punching, trimming
Defects: excessive burrs, deformation, surface scratches, size inconsistencies, few holes, etc.
1) The burr is too large → the gap between the convex and concave die is too large or too small; the cutting edge is worn; the guiding accuracy is poor; the position of the convex and concave die is not concentric, etc.
2) Deformation → The hole distance is too small; the pressure plate does not fit well with the concave mold surface; the gap is too large, etc.
3) Surface scratches → drag and pull during operation; the sheet material is scratched during the cutting process.
4) Inconsistent size → material loading is not in place; positioning device is damaged or loose, position shifting, etc.
5) Fewer holes → the punch is broken; the length of the punch is not enough.
Defects: the flanging is not vertical, the flanging height is inconsistent, the flanging is rough, the flanging is cracked, etc.
1) Flanging is not vertical → the gap between the convex and concave molds is too large.
2) Inconsistent flanging height → uneven gap between convex and concave molds; inaccurate positioning; the inaccurate size of blanking parts.
3) Flanging and roughening → There are scars on the cutting edge; there are impurities on the surface of the part; the cutting edge hardness is too low.
4) Flanging crack → large burrs when trimming; the gap between the convex and concave molds is too small; there is a sudden change in the shape of the flanging.
Defects: unqualified sheet metal bending angle, cracked bending edge, step at bending R angle, etc.
1) The bending angle is unqualified → the gap between the convex and concave molds is too large, and the matching angle of the convex and concave molds does not match the thickness of the plate material.
2) The bending edge is broken → the gap between the punch and the die is too small; the bending angle is too small; the punching force is too large and the speed is too fast; the plate material is too hard.
3) The bending R angle has steps → the convex and concave die bending angle is too large; the outer R angle is too large; the bending force is too small.