Patent ID: 7152444
Filing Date: 2006-12-26
Classification: B30B

Abstract:
1. A press forming machine comprising: a fixed plate; a pressure plate facing the fixed plate, having a forming space between the pressure plate and the fixed plate and being capable of reciprocating; a plurality of driving shafts for pressing the pressure plate at three or more respective pressure points distributed on the pressure plate by engaging with the pressure plate; a plurality of driving sources for respectively driving the plurality of driving shafts; control means for independently driving and controlling each of the plurality of driving sources; and displacement measuring means for measuring a positional displacement of the pressure plate adjacent each of the pressure points; wherein at least one pressure point (hereinafter referred to as “central pressure point”) among the pressure points is set between or surrounded by other pressure points (hereinafter referred to as “peripheral pressure points”), a gap between a driving shaft engaged with the pressure plate at the central pressure point and the pressure plate is larger than a gap between a driving shaft engaged with each of the peripheral pressure points and the pressure plate, and the control means is provided with means which measures the positional displacement adjacent each of the pressure points by the displacement measuring means on each of a plurality of operation stages during a press-forming operation, detects a state in which the entire pressure plate is kept at desired displacement positions, extracts a control data for each of the plurality of driving sources to keep the entire pressure plate at the desired displacement positions, supplies the extracted control data to each of the plurality of driving sources, and individually drives the plurality of driving sources.