| 摘要 |
PROBLEM TO BE SOLVED: To provide a press-forming method including and clamping a metal plate with a punch and a die arranging a blank holder, which improves a forming limit of generating a crack in the metal plate, is easily applicable to a large-scale press-forming machine, and is conducted at low cost, even if the shape of parts to be formed is complicated or a metal plate stock has high strength, without using special means such as replacement of the shape of a press-forming mold with another one, alteration of the shape or the quality of a blank into a special one, and micro-vibration of the press-forming mold by use of ultrasonic waves or the like. SOLUTION: In the press-forming method for the metal plate, after starting forming by bringing a punch 10 into contact with the metal plate at first in such a state that the metal plate (100) is clamped with a blank holder 30 and a die 20, an operation of separating the blank holder once from the metal plate, feeding lubricant between the metal plate and the fold, and forming the metal plate again with the same punch, the same die and the same blank holder is conducted once or more before the punch reaches a terminal end of a stroke to complete the forming of the metal plate. COPYRIGHT: (C)2006,JPO&NCIPI
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