Numerical controlling unit having tool-breakage detecting function
First Claim
1. A numerical controlling unit comprising:
- an inputting part into which a machining program for machining a workpiece is inputted;
an analyzing part that analyzes the machining program to generate an instructed spindle rotational speed and calculates a spindle load ratio indicating a ratio of a load applied to a spindle under a machining condition according to the machining program, with respect to a spindle load being caused when the workpiece is machined under a machining condition of a certain reference;
a distributing part that generates, based on the machining program, a distribution amount per unit period to be inputted into a feed-axis servo driver for moving a feed axis;
a spindle-rotational-amount-command outputting part that receives the instructed spindle rotational speed and outputs a spindle-rotational-amount command for commanding a rotational amount per unit period;
a spindle driver into which the spindle-rotational-amount command is inputted;
a cutting-load-for-judgment calculating part that calculates a reference torque value based on the spindle load ratio outputted by the analyzing part, the distribution amount outputted by the distributing part, and the spindle-rotational-amount command outputted by the spindle-rotational-amount-command outputting part; and
a spindle-load comparing part that compares the reference torque value with a load torque value which is feedback inputted by the spindle driver and outputs a tool-breakage detecting signal when the load torque value is higher than the reference torque value.
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Abstract
A numerical controlling unit according to the present invention includes: an inputting part into which a machining program for machining a workpiece is inputted; an analyzing part that analyzes the machining program to generate an instructed spindle rotational speed and calculates a spindle load ratio indicating a ratio of a load applied to a spindle under a machining condition according to the machining program, with respect to a spindle load being caused when the workpiece is machined under a machining condition of a certain reference; and a distributing part that generates, based on the machining program, a distribution amount per unit period to be inputted into a feed-axis servo driver for moving a feed axis. A spindle-rotational-amount-command outputting part receives the instructed spindle rotational speed and outputs a spindle-rotational-amount command for commanding a rotational amount per unit period. The spindle-rotational-amount command is inputted into a spindle driver. A cutting-load-for judgment calculating part calculates a reference torque value based on the spindle load ratio outputted by the analyzing part, the distribution amount outputted by the distributing part, and the spindle-rotational-amount command outputted by the spindle-rotational-amount-command outputting part. A spindle-load comparing part compares the reference torque value with a load torque value which is feedback inputted by the spindle driver and outputs a tool-breakage detecting signal when the load torque value is higher than the reference torque value.
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Citations
4 Claims
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1. A numerical controlling unit comprising:
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an inputting part into which a machining program for machining a workpiece is inputted;
an analyzing part that analyzes the machining program to generate an instructed spindle rotational speed and calculates a spindle load ratio indicating a ratio of a load applied to a spindle under a machining condition according to the machining program, with respect to a spindle load being caused when the workpiece is machined under a machining condition of a certain reference;
a distributing part that generates, based on the machining program, a distribution amount per unit period to be inputted into a feed-axis servo driver for moving a feed axis;
a spindle-rotational-amount-command outputting part that receives the instructed spindle rotational speed and outputs a spindle-rotational-amount command for commanding a rotational amount per unit period;
a spindle driver into which the spindle-rotational-amount command is inputted;
a cutting-load-for-judgment calculating part that calculates a reference torque value based on the spindle load ratio outputted by the analyzing part, the distribution amount outputted by the distributing part, and the spindle-rotational-amount command outputted by the spindle-rotational-amount-command outputting part; and
a spindle-load comparing part that compares the reference torque value with a load torque value which is feedback inputted by the spindle driver and outputs a tool-breakage detecting signal when the load torque value is higher than the reference torque value. - View Dependent Claims (2, 3, 4)
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Specification