Control device for a die cushion mechanism

A control device for a die cushion mechanism that produces a force for a slide in a press machine using servo motors as a drive source, comprising:

• slide velocity command-forming means for forming a velocity command for said slide;
• die cushion velocity command-forming means for forming a velocity command for said die cushion;
• and
• velocity relation calculation means for calculating a velocity relation between the velocity of said slide and the velocity of said die cushion based on a rate of increase in the force produced between said slide and said die cushion immediately after the collision of said slide with said die cushion;
• wherein said slide velocity command-forming means forms the velocity command for said slide based upon the die cushion velocity command formed by said die cushion velocity command-forming means and upon said velocity relation calculated by said velocity relation-calculation means.

A control device for a die cushion mechanism that produces a force for a slide in a press machine using servo motors as a drive source, comprising:

• slide velocity command-forming means for forming a velocity command for said slide;
• die cushion velocity command-forming means for forming a velocity command for said die cushion;
• and
• velocity relation calculation means for calculating a velocity relation between the velocity of said slide and the velocity of said die cushion based on a rate of increase in the force produced between said slide and said die cushion immediately after the collision of said slide with said die cushion;
• wherein said slide velocity command-forming means and said die cushion velocity command-forming means, respectively, form the velocity command for said slide and the velocity command for said die cushion based upon said velocity relation calculated by said velocity relation-calculation means.