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US 2016/0116900 A1Published application
Numerical control device and method
AssigneeOkuma Corporation
InventorYoichi KAWAI
Life of this patent
Estimating the term…
Abstract
A numerical control device with a function to prevent a problem caused by a rapid stop of a processing operation due to a motor overheating during processing. A temperature comparator obtains a load ratio T/Tmax or Tw/Tmax which is a ratio of the motor temperature T or predicted temperature Tw to a maximum allowable temperature Tmax stored in a storage device. When the load ratio T/Tmax or Tw/Tmax is over a threshold Tp stored in a storage, the device is placed in an alarm mode to shutdown the power supply to the motor after the processing program is executed to the end of a sequence block or the end of the processing program.
Claims8
A numerical control device comprising:
- an NC command generator that outputs a positional command by executing a processing program;
- a position controller that receives inputs of the positional command and a positional feedback from an encoder sensing a position of a movable element of a motor, obtains a speed command based on the received inputs, and outputs the speed command;
- a speed controller that receives inputs of the speed command and a speed feedback from the encoder, obtains a current command based on the received inputs, and outputs the current command;
- a current controller that receives inputs of the current command and a current feedback, obtains an inverter drive command based on the received inputs, and outputs the inverter drive command;
- an inverter circuit that controls the motor in accordance with the inverter drive command;
- a motor temperature sensor that senses or predicts a temperature of the motor;
- and
- a power supply controller that
- calculates a load ratio that is a ratio of the motor temperature sensed or predicted by the motor temperature sensor to a predetermined maximum motor allowable temperature, and
- controls to shutdown a power supply to the motor after allowing the NC command generator to execute the processing program to an end of a sequence block or an end of the processing program when the calculated load ratio is over a predetermined threshold.
7 more elements
A method comprising:
- outputting a positional command by executing a processing program by an NC command generator;
- receiving inputs of the positional command and a positional feedback from an encoder sensing a position of a movable element of a motor, obtaining a speed command based on the received inputs, and outputting the speed command;
- receiving inputs of the speed command and a speed feedback from the encoder, obtaining a current command based on the received inputs, and outputting the current command;
- receiving inputs of the current command and a current feedback, obtaining an inverter drive command based on the received inputs, and outputting the inverter drive command;
- controlling the motor in accordance with the inverter drive command;
- sensing or predicting a temperature of the motor;
- and
- calculating a load ratio that is a ratio of the sensed or predicted motor temperature to a predetermined maximum motor allowable temperature, and shutting down a power supply to the motor after allowing the NC command generator to execute the processing program to an end of a sequence block or an end of the processing program when the calculated load ratio is over a predetermined threshold.
5 more elements
A numerical control device comprising:
- an NC command generator that outputs a positional command by executing a processing program;
- a position controller that receives inputs of the positional command and a positional feedback from an encoder sensing a position of a movable element of a motor, obtains a speed command based on the received inputs, and outputs the speed command;
- a speed controller that receives inputs of the speed command and a speed feedback from the encoder, obtains a current command based on the received inputs, and outputs the current command;
- a current controller that receives inputs of the current command and a current feedback, obtains an inverter drive command based on the received inputs, and outputs the inverter drive command;
- an inverter circuit that controls the motor in accordance with the inverter drive command;
- a motor temperature sensor that senses or predicts a temperature of the motor;
- and
- a cut depth controller that
- calculates a load ratio that is a ratio of the motor temperature sensed or predicted by the motor temperature sensor to a predetermined maximum motor allowable temperature, and
- controls to reduce a cut depth commanded by the processing program when the calculated load ratio is over a predetermined threshold.
7 more elements
A method comprising:
- outputting a positional command by executing a processing program by an NC command generator;
- receiving inputs of the positional command and a positional feedback from an encoder sensing a position of a movable element of a motor, obtaining a speed command based on the received inputs, and outputting the speed command;
- receiving inputs of the speed command and a speed feedback from the encoder, obtaining a current command based on the received inputs, and outputting the current command;
- receiving inputs of the current command and a current feedback, obtaining an inverter drive command based on the received inputs, and outputting the inverter drive command;
- controlling the motor in accordance with the inverter drive command;
- sensing or predicting a temperature of the motor;
- and
- calculating a load ratio that is a ratio of the sensed or predicted motor temperature to a predetermined maximum motor allowable temperature, and controlling to reduce a cut depth commanded by the processing program when the calculated load ratio is over a predetermined threshold.
5 more elements
Dependencies are inferred from the claim text.