P-type folded edge bending process

Abstract

The invention discloses a P-type folded edge bending process. The P-type folded edge bending process comprises the following steps that a first folded edge is bent downwards to be formed; a second folded edge is bent downwards to be formed; a third folded edge is bent downwards to be formed, and the included angle between the third folded edge and the bottom edge is 140 degrees; the third folded edge continues to be bent downwards to be formed, and the included angle between the third folded edge and the bottom edge is 90 degrees; and the third folded edge is continuously bent downwards to beformed, and the included angle between the third folded edge and the bottom edge is 43 degrees. One step is added before an existing two-step forming method, a material at the bending line of the third folded edge is intermittently and continuously stretched three times, the elastic stress of the material is thoroughly eliminated, and it is guaranteed that the negative angle of a P-type folded edge does not rebound any more after being formed.

Description

technical field [0001] The invention belongs to the technical field of stamping dies, and relates to a P-type hemming and bending process. Background technique [0002] Some stampings will be designed as figure 1 The P-shaped hemming shown in includes the first hem 10, the second hem 20, the third hem 30 and the bottom 40. The angle between the third hem and the bottom is a negative angle of about 43°. At present, a two-step forming method is generally used for the bending of negative angles, that is, the folded edge is bent downward by 90°, and then the folded edge is pushed sideways to form a negative angle. This method is suitable for a negative angle of about 80°. figure 1 If the negative angle is less than 43°, the extension line of the folded edge 2 and the extension line of the bottom edge will intersect at a certain point. If the existing two-step forming method is used, it cannot be guaranteed that the negative angle after bending will not spring back. Contents o...

AI Technical Summary

Problems solved by technology

At present, a two-step forming method is generally used for the bending of negative angles, that is, the folded edge is bent downward by 90°, and then the folded edge is pushed sideways to form a negative angle. This method is suitable for a negative angle of about 80°. figure 1 If the negative angle is less than 43°, the extension line of edge 2 and the extension line of the bottom edge will intersect at a certain point. If the existing two-step forming method is used, it cannot be guaranteed that the negative angle after bending will not spring back

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