| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for hydroforming, which method can control the material flow in hydrobulging without adopting special welding patterns as a laminated plate, and further without increasing the number of processes. SOLUTION: An overhang 10c is preliminarily formed at the edge of the laminated plate 10 as a non-overlapped portion. First, the overhang 10c is bent so as to form a flange portion 11 by cooperation of a bending punch 3 with a bending die 4 attached to an upper die 1 and a lower die 2 respectively in the state that the laminated plate 10 has been pressed and constrained by tightening the upper die 1 and the lower die 2. Successively, the hydrobulging is carried out by introducing hydraulic pressure to the laminated plate 10. During the hydrobulging operation, the flow rate of material is regulated by engaging the flange portion 11 with the edge portion 12 of the lower die 2. COPYRIGHT: (C)2006,JPO&NCIPI
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