Patent ID: 7905126

Claim:
A die-cushion controlling device for a press machine, comprising: a position-command-signal outputting section that outputs a first position command signal corresponding to a target position value of a die-cushion pad; a position detecting section that detects a position of the die-cushion pad; an escape-position-command-signal outputting section that outputs a second position command signal for commanding the die-cushion pad to downwardly escape from a position detection value received when the die-cushion pad has reached its own bottom dead center position by a predetermined escape height when a press signal is received, wherein the press signal is outputted when a slide of the press machine has reached a bottom dead center position; an output switching section that selectively outputs one of the first position command signal output by the position-command-signal outputting section and the second position command signal output by the escape-position-command-signal outputting section; a position comparing section that outputs a position deviation signal corresponding to a deviation between the target position value based on the position command signal output by the output switching section and a position detection value based on a position detection signal from the position detecting section; a position controlling section that outputs a position-speed command signal based on the position deviation signal; a speed controlling section that outputs a motor-current command signal based on the position-speed command signal output from the position controlling section; and a servo amplifier that feeds an electric servo motor for driving a die cushion with a current corresponding to the motor-current command signal.