Abstract
There are many demands for cup-shaped parts with a gear shape in the automotive industry and a large load is often required for the complete filling of the gear portion in conventional progressive forming. In this study, a new method was proposed for solving the problem using a multi-action press. This method features the operation of depressing the cup wall to provide an appropriate shape for gear filling with the cup corner prior to gear forming. Experiments and FE analysis were carried out, varying the amount of cup wall depression. The filling ratio of the gear increased with increasing amount of cup wall depression and complete filling was achieved with a low load compared with progressive forming. An increase in load and burr formation were observed after the cup corner reached the bottom of the die. Accordingly, the optimum conditions for cup wall depression should be determined so that the unfilled portion is minimized at the stroke that the cup corner reaches the bottom of the die.
