Study on an automotive refill opening cap compound process based on punching and incremental forming

摘要

An automotive refill opening cap manufactured through the traditional punching process usually performs with lower rigidity, and the punching process increases the production cost and manufacturing cycle, which goes against the fast fabricating requirement in modern industry because of the multi-die produced. In this paper, the compound process, adopting incremental sheet forming (ISF) and punching forming, was used to manufacture the part to solve the problems above by utilizing ISF in the pre-forming stage and punching forming in the subsequent stage. Four parameters, including the pre-forming height (PH), the pre-forming press amount (PPA), the pre-forming tool diameter (PTD) and the pre-forming angle (PA), were taken as test factors in the pre-forming stage, and the max thickness reduction percentage (MTRP) was taken as the test target. The effect of the factors was analyzed using the finite element method and an orthogonal test for the target. The orthogonal test result shows that the major factors were the PH and the PPA, and the secondary factors were the PA and the PTD. The PTD and the PA were obtained through a mean analysis as 8 mm and 40°, respectively. A function showing the relationship between the major factors and the target was established through the response surface method to obtain the interaction effect between the PH and the PPA for the target. The PH and the PPA were found by a response surface methodology to be 15 mm and 0.5 mm, respectively. The compound process was verified through an experiment.