NUMERICAL CONTROL APPARATUS
First Claim
1. A numerical control apparatus comprising:
- a cycle-time measuring unit that measures a cycle time in machining a workpiece;
a current-amount measuring unit that measures a current amount per unit cycle flowing to a motor that drives a workpiece rotating shaft;
a cycle-time calculating unit that calculates, on the basis of the measured current amount per unit cycle, a cycle time at which suppression of the occurrence of overheating of the motor is guaranteed;
a processing unit that determines on the basis of a comparison of a cycle time calculation value by the cycle-time calculating unit and a cycle time measurement value by the cycle-time measuring unit whether the motor overheats; and
a delay unit that delays, when the processing unit determines that the motor overheats, a start of a next cycle by at least a value obtained by subtracting the cycle time measurement value from the cycle time calculation value.
1 Assignment
0 Petitions
Accused Products
Abstract
To avoid overheating of a spindle motor as easy as possible, a numerical control apparatus measures a cycle time in machining a work (step S5), measures a current amount per unit cycle flowing to the spindle motor (steps S3 and step S4), calculates, on the basis of the measured current amount per unit cycle, a duty cycle time in which suppression of the occurrence of overheating of the spindle motor is guaranteed (step S6), determines on the basis of a comparison of the duty cycle time and the cycle time whether the spindle motor overheats (step S7), and, when the spindle motor overheats (Yes at step S7), delays a start of the next cycle by a wait time setting value Tw obtained by subtracting the cycle time from the duty cycle time (step S8, No at step S10, and step S11).
16 Citations
8 Claims
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1. A numerical control apparatus comprising:
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a cycle-time measuring unit that measures a cycle time in machining a workpiece; a current-amount measuring unit that measures a current amount per unit cycle flowing to a motor that drives a workpiece rotating shaft; a cycle-time calculating unit that calculates, on the basis of the measured current amount per unit cycle, a cycle time at which suppression of the occurrence of overheating of the motor is guaranteed; a processing unit that determines on the basis of a comparison of a cycle time calculation value by the cycle-time calculating unit and a cycle time measurement value by the cycle-time measuring unit whether the motor overheats; and a delay unit that delays, when the processing unit determines that the motor overheats, a start of a next cycle by at least a value obtained by subtracting the cycle time measurement value from the cycle time calculation value. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A numerical control apparatus comprising:
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a storing unit that stores in advance continuous operation time information indicating the relation between an electric current flowing to a motor, which drives a workpiece rotating shaft, and a time until overheating of the motor occurs in a state in which the electric current flows; a cycle-time measuring unit that measures a cycle time in machining a workpiece; a current-amount measuring unit that measures a current amount per unit cycle flowing to the motor; and an estimation processing unit that estimates, on the basis of a cycle time measurement value by the cycle-time measuring unit, a current amount measurement value by the current-amount measuring unit, and the continuous operation time information, the time in which the workpiece can be continuously machined, or a number of workpieces that can be continuously machined.
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8-9. -9. (canceled)
Specification