Study on the multi-point forming process with a swinging punch unit

A spherical surface with a radius of R500 was used as the target surface for this study. The forming processes of three different forming methods, namely, using a fixed punch unit, using a polyurethane elastic pad, and using a swinging punch unit, were studied by numerical simulations and experimental methods. The forming process, forming principle, and mechanical structure of the three forming methods were discussed, and the effects of the three forming methods on the forming quality and accuracy of the sheet metal were analyzed in detail with respect to surface quality, curvature distribution, material thickness distribution, and spring-back. The results show that using the swinging punch unit can effectively restrain dimple and wrinkle defects, increase the plastic deformation degree of the sheet, and reduce spring-back.