| 摘要 |
PROBLEM TO BE SOLVED: To provide a mold for press forming which stably generates a reverse bending deformed part by overrun even when a die shoulder radius is large, reduces a phenomenon such as a wall camber as much as possible, and can improve a dimensional accuracy of press forming of a metal plate as a result. SOLUTION: A projecting part elongating in the direction of a die is formed at the region of the head of a punch corresponding to the part formed at the early period of forming, further, a recessed part is not formed at the die, and the punch-die clearance CL2 corresponding to the part formed at least immediately after the early period of press forming is set broader than the punch-die clearance CL1 corresponding to the part formed at the early period of press forming (CL1<CL2). Further, the thickness t (mm) of the metal plate to be formed and the clearances CL1, CL2 are set so as to satisfy prescribed relationships, respectively, and in a state where the forming of a vertical wall part is completed, overrun is generated at the metal plate, further, the overrun is amplified upon mold releasing, and reverse bending is generated at the formed metal plate. COPYRIGHT: (C)2009,JPO&INPIT
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