when the automobile stamping parts are stretched, the flange wrinkles and sidewall wrinkles will be generated due to compression deformation. to avoid this phenomenon, the inner tensile stress of the plate can be increased to eliminate wrinkles, and the tensile ribs can also be increased and reduced. the fillet radius of the small die, adjust the gap of the blanking surface and the stretching gap to increase the blank holder force. the tensile deformation force of the partially formed internal stamping parts is higher than that of the side wall material, which will cause bidirectional elongation and deformation. if the external material cannot supplement the internal part, the deformation will be too large and cracks will occur. how to overcome this problem?
first, the blanking method is used to cut the material to ensure the quality of the edge section of the blank, thereby improving the edge state of the blank, and appropriately increasing the material size to effectively determine the size of the concave flanging blank. if the size of the blank becomes larger or the shape is improper, it is necessary to change its size or shape and adjust the stamping process to overcome edge cracks.
secondly, the gap between the convex and concave molds should be uniform, and the round corners of the convex and concave molds should be increased appropriately, and the drawing process or the shaping process should be increased to ensure that the resistance of the materials entering the concave mold is uniform and consistent, which can effectively overcome the shear fracture.