Patent ID: 7421878

Claim:
A control device of a die cushion mechanism of a press machine, for generating a force applied to a slide of the press machine by using a servomotor as a driving source, the control device comprising: a force commanding part for generating a force command including a commanded force value to be generated between the slide and the die cushion mechanism; a force detecting part for detecting a force generated between the slide and the die cushion mechanism; a speed commanding part for generating a speed command including a commanded speed value of the servomotor based on the commanded force value and a force detected by the force detecting part; a speed detecting part for detecting a speed of the servomotor; a current commanding part for generating a current command including a commanded current value of the servomotor based on the commanded speed value and a speed detected by the speed detecting part; and a correcting part for correcting at least one of the commanded speed value and the commanded current value corresponding to an acceleration of the slide, wherein the control device further comprises a slide position detecting part for detecting the position of the slide such that the acceleration of the slide is obtained by second-order differentiation of the position of the slide detected by the slide position detecting part.