Patent ID: 8156850
Filing Date: 2012-04-17
Classification: B23B,B23Q,G05B,Y10T

Abstract:
1. A tailstock control device which supports an object to be machined by driving and controlling a servo motor which drives a driving system of a tailstock having a spring member in forward and backward directions, to cause a tailstock center connected to the tailstock to contact a center hole of the object to be machined, the tailstock control device comprising: a limit torque value calculating unit which calculates, as a limit torque value, a drive torque value of the servo motor necessary for supporting the object to be machined; and a servo control unit which drives and controls the servo motor to attempt to move the tailstock at a tailstock movement velocity which is set in advance, until an output torque value of the servo motor reaches the limit torque value, wherein the limit torque value calculating unit comprises: a unit which calculates, as a support thrust, a thrust of the tailstock necessary for supporting the object to be machined; an excessive thrust calculating unit which calculates, as an excessive thrust, an excessive thrust due to an elastic restoring force caused by compression of the spring member during a period between the contact of the tailstock center moving at the tailstock movement velocity with the object to be machined, and stopping of the tailstock center; and a unit which calculates the limit torque value by subtracting the excessive thrust from the support thrust.