| 摘要 |
PROBLEM TO BE SOLVED: To provide a press working method and a press working apparatus by which the occurrence of cracks in the end parts to which stretch-flanging is applied is prevented. SOLUTION: In the press working apparatus, a steel sheet 12 is held with a holder 40 and blank holders 54 and, in the state where blank holding force is applied to the steel sheet, a potion of the steel sheet 12 is press-formed by lowering a fixed upper die 41. Next, in the state where the blank holding force applying to the steel sheet 12 is released by lowering the blank holders 54, a bent part is formed by performing the stretch-flanging of the rest portion of the steel sheet 12 by lowering a second upper die 90. COPYRIGHT: (C)2008,JPO&INPIT
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