Patent ID: 6463835
Filing Date: 2002-10-15
Classification: B23B,B23Q,G05B,Y10T

Abstract:
A method of controlling a motor-driven chucking device in which gripping jaws of a chuck provided on a main spindle rotatably supported by a frame provided on a body of a machine tool are opened or closed by a torque controllable driving motor to grip a workpiece, said method comprising the steps of:inputting a set value for gripping force, with which said gripping jaws grip the workpiece, by a command from an NC machining program; providing a correspondence between values of a driving torque of said driving motor and values of a gripping force of said chuck; opening or closing said gripping jaws by controlling rotation of an output shaft of said driving motor according to the set value for said gripping force; and stopping movement of said gripping jaws when said driving torque of said driving motor has reached a value corresponding to the set value for said gripping force.