Press working method with a pinch release step and apparatus performing such method

摘要

In a press working apparatus (10), while a servo motor (24) is acting, an upper die (238) is made to come close to a lower die (252) while the plate (212) is being pinched by a first holder (240) and a second holder (254). The pinch conducted by the first holder (240) and the second holder (254) on the plate (212) is released after press forming of the plate (212) was started in the press forming step and before both dies (238,252) reach a bottom dead center (x2) at which the dies (238,252) are made to come close to each other.