Defects

Reasons

Measures

Uneven and wrinkled edges of deep drawn parts.

The center of the blank does not match the center of the convex and concave molds, or the material thickness is uneven, as well as the radius of the concave mold fillet and the gap between the convex and concave molds are uneven (the concave mold fillet radius is too large, and in the final stage of deep drawing, it detaches from the edge pressing ring, causing the edge pressing ring of the material that has not yet crossed the fillet to wrinkle and be pulled into the concave mold to form edge wrinkles.

Repositioning the punching die, correcting the radius of the concave die corner and the gap between the convex and concave dies to make them uniform in size, and then putting them into production (reducing the radius of the concave die corner or using an arc-shaped edge pressing ring device can eliminate wrinkles).

Wrinkles on the waist during deep drawing of conical or hemispherical parts.

At the beginning of deep drawing, most of the material is in a suspended state, coupled with too little edge pressure, too large radius of the concave die corner, or too much lubricant used. Reducing the radial tensile stress causes the material to lose stability and wrinkle under the action of tangential compressive stress.

Increase the edge pressing force or use a rolling rib structure to reduce the radius of the concave die corner or slightly increase the material thickness.