Patent ID: 6705186
Filing Date: 2004-03-16
Classification: B23B,Y10T

Abstract:
A control unit of a machine tool, said machine tool comprising:a spindle being rotatable with an axial center as its center a chuck provided on said spindle; a plurality of sliding members provided at said chuck, being free to move with respect to said axial center; workpiece holding members provided at each said sliding member, being free to move and drive with respect to said axial center and being free to be fixed and held; reciprocating drive means provided at said chuck, being free to drive and reciprocate within a predetermined stroke, thereby being free to move and drive said sliding member in a direction of said axial center; said machine tool having further characteristic: projecting said workpiece holding members in said axial center direction and driving said reciprocating drive means so a to move said sliding members in said axial center direction when a workpiece is fixed and held with said chuck; said control unit comprising: a sensor for detecting that the state of said workpiece being fixed and held with said workpiece holding members is released during rotation of said spindle; and a driving control means of said sliding member for driving and controlling said reciprocating drive means so as to drive said sliding member in said axial center direction when said sensor detects the state of said workpiece being fixed and held with said workpiece holding members is released.