To provide a hydroforming method which does not cause wrinkles on a formed article and can achieve high material yield and superior productivity.
In the hydroforming method, after two pieces of metal plates 2 piled together are gripped by an upper die 11 and a lower die 12 and clamped, high pressure water is injected between the two pieces of the metal plates 2 for applying inner pressure, and the metal plates 2 are formed into a shape of a cavity 13 formed respectively in the upper die 11 and the lower die 12. The upper die 11 and the lower die 12 have gripping faces 14 to grip the two pieces of metal plates 2 on the entire periphery of the cavity 13 respectively, and have also protrusions 15 protruded from the gripping faces 14 consecutively formed around the entire periphery of the cavities 13. The protrusions 15 are bitten into the metal plate 2 to form locking beads 25 during die-clamping. The metal plate 2 is locked so that the metal material outside the locking beads 25 does not flow into the cavity 13 side while applying inner pressure.
YAMANAKA MASAMI
TOMIZAWA ATSUSHI
UCHIDA MITSUTOSHI
SUMITOMO METAL IND
| JPH1085944A | 1998-04-07 | |||
| JP2001001065A | 2001-01-09 | |||
| JP2001511706A | 2001-08-14 | |||
| JP2002273526A | 2002-09-25 | |||
| JP2002001449A | 2002-01-08 |
| US4331284A | 1982-05-25 |
Tamiwa Iwakura