Motor control apparatus capable of protecting process face at the time of occurrence of abnormal load

Patent metadata

Field	Value
Publication number	US-10095212-B2
Application number	US-201715499141-A
Country	US
Kind code	B2
Filing date	Apr 27, 2017
Priority date	Mar 19, 2014
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

A motor control apparatus controlling a motor driving a machine tool includes, an abnormal load detecting unit that detects an abnormal load by monitoring a load of the motor, a retract amount storing unit that stores a plurality of retract amounts used when the machine tool performs a retract operation in response to detection of an abnormal load by the abnormal load detecting unit, a retract amount switching unit that switches a retract amount selected from the plurality of retract amounts in accordance with a result of determination of whether the machine tool is processing or not, and a retract amount adding unit that adds a retract amount selected by switching of the retract amount switching unit to an instruction value indicative of a movement amount of the machine tool.

First claim

What is claimed is:

1. A motor control apparatus controlling a motor driving a machine tool, the machine tool having two modes of operation: a processing mode and a non-processing mode, the motor control apparatus comprising:
an abnormal load detecting unit that detects an abnormal load by monitoring a load of the motor;
a retract amount storing unit that stores a plurality of retract amounts used when the machine tool retracts in response to detection of an abnormal load by the abnormal load detecting unit;
a retract amount switching unit that selects a retract amount from the plurality of retract amounts in accordance with a result of determination of whether the machine tool is operating in the processing mode or the non-processing mode; and
a retract amount adding unit that adds a retract amount selected by switching of the retract amount switching unit to an instruction value indicative of a movement amount of the machine tool.

2. The motor control apparatus according to claim 1 , wherein the retract amount switching unit switches a retract amount to be selected in accordance with a mode signal input from a host controller indicating whether the machine tool is operating in the processing mode or the non-processing mode.

3. The motor control apparatus according to claim 1 , wherein the retract amount switching unit selects a retract amount in accordance with a switch signal input from an external device.

4. The motor control apparatus according to claim 1 , wherein a retract amount selected when it is determined that the machine tool is operating in the processing mode is rewritten in accordance with a process program used.

5. The motor control apparatus according to claim 1 , wherein a retract amount selected when it is determined that the machine tool is operating in the processing mode is rewritten in accordance with a process state of a workpiece processed by the machine tool.

Assignees

• Fanuc Corp

Inventors

• Takayama Kenichi
• Tang Zhiwei

Classifications

• G05B2219/42289

  Avoid overload servo motor, actuator limit servo torque · CPC title

• G05B2219/37025

  Retract, swing out of the way, measuring device during normal machining for protection · CPC title

• G05B2219/49147

  Retract on collision with moving object, tool follows, yields to object · CPC title

• B23Q15/225

  in feed control, i.e. approaching of tool or work in successive decreasing velocity steps · CPC title

• B23Q15/013

  Control or regulation of feed movement (B23Q15/12 takes precedence) · CPC title