Patent ID: 6871586

Claim:
A slide drive apparatus for a pressing machine, comprising: a slide; a servo motor for controlling slide motion, wherein a rotation angle and speed of said servo motor are controlled to produce a desired slide motion; a mechanical power transmission mechanism coupled to the servo motor for converting rotational power of said servo motor for controlling slide motion into vertical reciprocating motion of said slide; a plunger incorporated in said power transmission mechanism and connected to said slide through an adjusting screw; and a servo motor for adjusting die height coupled to the adjusting screw, which performs die height adjustment of said slide through position control by rotating the adjusting screw to vary a spacing between said slide and said plunger; and a control unit for receiving a signal from a sensor which directly and constantly monitors a position of said slide so as to drive said servo motor for adjusting die height to accurately vary the spacing between said slide and said plunger.