Numerical control apparatus
AssigneeFanuc Corporation
InventorsHideaki Kawamura, Kentaro Fujibayashi, Toshiaki Otsuki
Life of this patent
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Abstract
A numerical control apparatus according to the invention for interpolatory control of a tool along the shape of a workpiece to be machined. In order to perform offsetting of a cutting tool by an amount equivalent to the tool diameter when involute interpolation is carried out, an involute curve is approximated by a circular which is set in dependence upon the intersection angle of a machining trajectory at a command point commanding the start of machining.
Claims11
A numerical control apparatus having a tool control function for machining a workpiece into a shape along an involute curve, comprising:
- setting means for setting an approximation circle approximating the involute curve in accordance with an intersection angle at a command point commanding the start of machining along the involute curve;
- arithmetic means for computing a command point offset vector at the command point based on both the approximation circle and a tool offset quantity of a tool trajectory up to the command point;
- and
- interpolating means for interpolating the involute curve as offset by a tool diameter based on the command point offset vector.
A numerical control apparatus for machining a workpiece with a tool along an involute curve, the involute curve having a command point and an intersection angle with a magnitude, the tool having a tool offset quantity, said apparatus comprising:
- curve approximation means for approximating the involute curve with an approximate circle based upon the magnitude of the intersection angle;
- interpolation means for switching from offset linear interpolation to offset circular interpolation at the command point;
- and
- processor means for calculating an offset vector at the command point based on the approximate circle and the tool offset quantity, and for outputting circular interpolation data to machine the workpiece.
A method for machining a workpiece with a tool along an involute curve, the involute curve having a command point and an intersection angle with a magnitude, said method comprising the steps of:
- (a) switching from offset linear interpolation to offset circular interpolation at the command point;
- (b) approximating the involute curve with an approximate circle based upon the magnitude of the intersection angle;
- (c) calculating an offset vector based on the approximate circle and outputting circular interpolation data to machine the workpiece;
- and
- (d) converting the circular interpolation data into signals for controlling the machining of the workpiece.
Dependencies are inferred from the claim text.