cause

The gap between the concave and the punch is too small, resulting in cracks on both sides of the punch and the die without coincidence, and two extruded shear occurs at both ends of the section.

The gap between the concave and punch is too large, and when the punch falls, the crack occurs late, and the shear is completed like tearing, resulting in non-coincidence of cracks.

The cutting edge is worn or rounded and chamfered, the cutting edge does not play the role of wedge segmentation, and the entire section produces irregular tearing.

solution

Reasonable selection of the blanking gap of the concave and punch. Such punch cutting is between extrusion and stretching, and when the punch cuts into the material, the cutting edge forms a

wedge, causing the plate to produce nearly linear coincidence cracks.

Timely repair the rounded corners or chamfer produced by the concave and punch cutting edges.

Ensure the vertical concentricity of the concave and punch, so that the matching gap is uniform.

Ensure mold installation is vertical and smooth.