CORRECTING DEVICE FOR FEEDING MECHANISM OF NUMERICALLY CONTROLLED MACHINE TOOL AND THE SAME MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a position correcting device of a feeding mechanism of a numerically controlled machine tool capable of performing an appropriate correction of a gradually increasing type lost motion without being affected by any quadrantal projection.;SOLUTION: The position correcting device of this feeding mechanism is provided with a servo motor 11 for driving a table 9 on which a work 13 is mounted, control parts (20, 30, 40, 50, 60, and 70) for feeding back the position of the table obtained from the detection of the rotation of the servo motor in response to a position command value, and for feeding back a table speed obtained from the table position in response to a speed command value obtained from the position command value, and for converting the result into a torque command value or a current command value, and for supplying the value to the servo motor, a torque analyzing part (80) for detecting the changing point of torque accompanied with quadrant switching from the waveform of the torque command value, and for calculating time t01 and t02 between the changing points, and a correction amount calculating part (90) for calculating a table position error due to a gradually increasing type lost motion from the output of the torque analyzing part based on a theoretical formula, and for calculating correction amounts to the table position using the calculated error.;COPYRIGHT: (C)2002,JPO