Patent ID: 7086327
Filing Date: 2006-08-08
Classification: B30B

Abstract:
1. A press forming method comprising the steps of providing a press machine comprising a fixed plate, a slide plate disposed to face the fixed plate and movable relatively to the fixed plate, a plurality of drive sources each having a servo-motor for driving the slide plate and pressing each of a plurality of engaging portions positioned on the slide plate to press horizontally the slide plate, displacement measuring devices are provided near the respective engaging portions to measure a displacement of the slide plate, a control device for control driving of each of the drive sources, and press-forming a work-piece at descending speeds of the plurality of drive sources in a trial forming, the descending speeds being set to be sufficiently small and same among the plurality of drive sources at an initial stage of the trial forming and then adjusted so as to be close to target speeds of a production forming and so that a delay difference between a displacement of each of the plurality of drive sources and an instructed displacement is less than a predetermined value, by a delay adjustment step among the drive sources and a driving speed increasing step, wherein, in the delay adjustment step, each of the descending speeds for the plurality of driving sources is adjusted by such a speed increment that the delay difference becomes less than or equal to the predetermined value, and, in the driving speed increasing step, the descending speeds for the plurality of driving sources are adjusted to increase more than in the delay adjustment step and close to the target speeds of the production forming.