Control device for machine tool including rotary indexing device
First Claim
1. A control device for a machine tool including a rotary indexing device, the rotary indexing device comprising:
- a rotary table on which a work is to be mounted and fixed;
a clamping mechanism configured to clamp the rotary table;
a drive motor configured to rotate and drive the rotary table; and
a motor controller configured to control a rotation position and a speed of the drive motor,wherein the rotary table is configured to be clamped by the clamping mechanism at a target position of a predetermined rotation angle position,wherein the control device comprises a processor configured todetect an output torque of the drive motor,obtain a position deviation from the motor controller, andexecute a target position changing processing on a condition that a time, during which the detected output torque of the drive motor is equal to or higher than a preset permissible torque, continues for a predetermined time or the detected output torque of the drive motor reaches a preset upper limit torque while a work mounted on the rotary table is being machined, andwherein, in executing the target position changing processing, the processor is configured tochange the target position such that the output torque of the drive motor is brought close to or equal to 0 if the detected output torque is equal to or higher than the permissible torque, andchange the target position by increments such that the obtained position deviation is brought close to or equal to 0 if the detected output torque is smaller than the permissible torque.
1 Assignment
0 Petitions
Accused Products
Abstract
A rotary table is rotated by a machining load. A drive motor tries to return the rotary table to a positioned target position, and increases output torque. When the output torque reaches upper limit torque Tmax or when output torque which is equal to or greater than permissible torque Tp continues for predetermined time ΔT, a target position which is sent to a drive motor is changed, thereby promoting reduction in output torque. If the output torque becomes smaller than permissible torque Tp, the target position is changed to bring position deviation of the drive motor equal to 0, and the position deviation is swiftly returned.
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Citations
7 Claims
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1. A control device for a machine tool including a rotary indexing device, the rotary indexing device comprising:
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a rotary table on which a work is to be mounted and fixed; a clamping mechanism configured to clamp the rotary table; a drive motor configured to rotate and drive the rotary table; and a motor controller configured to control a rotation position and a speed of the drive motor, wherein the rotary table is configured to be clamped by the clamping mechanism at a target position of a predetermined rotation angle position, wherein the control device comprises a processor configured to detect an output torque of the drive motor, obtain a position deviation from the motor controller, and execute a target position changing processing on a condition that a time, during which the detected output torque of the drive motor is equal to or higher than a preset permissible torque, continues for a predetermined time or the detected output torque of the drive motor reaches a preset upper limit torque while a work mounted on the rotary table is being machined, and wherein, in executing the target position changing processing, the processor is configured to change the target position such that the output torque of the drive motor is brought close to or equal to 0 if the detected output torque is equal to or higher than the permissible torque, and change the target position by increments such that the obtained position deviation is brought close to or equal to 0 if the detected output torque is smaller than the permissible torque. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification