1. Influence of tensile depth
The distribution of the material flow resistance along the die orifice has a direct relationship with the stretching depth. In the position of concave and convex curves, the stretching depth of the stretching parts is too large to cause uneven distribution of deformation resistance, forming wrinkling, which should be prevented as far as possible.
2. Adjust the size of the blank holder force
When wrinkle occurs evenly all around the piece, should judge to be pressed material force is lacking, increase press material force gradually can eliminate wrinkle. When the drawing part stretches the conical part and the hemispherical part, most of the data is in suspension at the beginning of the drawing. The side wall is wrinkled easily, reason besides increasing blank holding force, precision stamping processing plant still should choose to increase to pick up extension bar to increase radial pull stress inside the plate, eliminate wrinkle.
3. The radius of the die fillet is affected
The radius of the corner of the concave die of the stretching die is too large, and the flow of the blank to the concave die through the concave die fillet is the smaller the bending resistance of the bending deformation. The smaller the zigzag resistance, the simpler the formation of wrinkling. The smaller the radius of the die, the greater the zigzag resistance of the bending deformation, the more not simple wrinkle, but easy to form the cracking and hair drawing phenomenon.
