FLANGE FORMING METHOD FOR PANEL

摘要

PURPOSE:To increase the bending accuracy of a flange by performing the bending of the step part facing the sectional die side prior to the flange forming stage. CONSTITUTION:A bending formation is performed on a flange forming part 20a simultaneously with a step part 21. In this case the size L1 of the rise part 22 of the step part 21 is made smaller than the size L2 between DC. The rise part 22 (between BD) is bent with press to the die face 9a side of punch 9 with being ironed after the bending between AB in the forming stage by a press die. In this case the end edge C comes easily into contact with the die face 9a of the punch 9 due to the size L2 being set smaller than the L1. The space between BD is therefore easily elongated by the ironing of the sectional die 10 and the reverse camber to the springback is formed. With this method the effect of the springback can be prevented in the bending of the flange and the work accuracy is increased.