Numerical control device having tool correction function in skiving processing
Command data indicating a command path of a tool is generated on the basis of tool data created on the basis of an inclination and a shape of the tool, and interpolation data for each interpolation period is generated and outputted. When a command block is a block commanding skiving processing, correction data for correcting the command path is generated on the basis of the tool data stored in the tool data storage unit, and the correction data corresponding to interpolation data outputted by an interpolation unit is outputted.
1. A numerical control device controlling a machine tool which performs skiving processing of cutting processing on a rotational symmetry surface of a rotating workpiece with a tool, on the basis of a processing program including a command block, the device comprising:
a tool data storage unit that stores tool data created on the basis of at least one of an inclination of the tool and a shape of the tool;
a processing program analysis unit that reads out and analyzes a command block from the processing program, and generates and outputs command data indicating a command path of the tool which is commanded by the command block;
an interpolation unit that performs interpolation processing on the basis of the command data, and generates and outputs interpolation data for each interpolation period of the interpolation processing; and
a correction unit that determines, when the command block is a block commanding the skiving processing, whether a current position of the tool is between a cutting start point and a cutting end point, and that generates, when the current position of the tool is between the cutting start point and the cutting end point and when the command block is the block commanding the skiving processing, correction data for correcting the command path for each interpolation period of the interpolation processing on the basis of the tool data stored in the tool data storage unit and the current position of the tool being between the cutting start point and the cutting end point, and outputs the correction data corresponding to the interpolation data outputted by the interpolation unit.
2. The numerical control device according to claim 1 , further comprising a tool data creation unit that generates the tool data on the basis of output of a sensor that measures the inclination of the tool or the shape of the tool, and stores the tool data in the tool data storage unit.
3. The numerical control device according to claim 1 , wherein
the tool data includes a coordination value at the cutting start point on a blade edge of the tool and a coordination value at least one point, on the blade edge, which is different from the cutting start point, and
the correction unit generates the correction data on the basis of a difference between the coordination value at the cutting start point on the blade edge of the tool and the coordination value at the point, on the blade edge, which is different from the cutting start point.
4. The numerical control device according to claim 1 , wherein the correction unit calculates a correction amount for correcting a position of a cutting point at which the workpiece perpendicularly comes into contact with the blade edge of the tool on the basis of the inclination of the blade edge of the tool, which is calculated on the basis of the tool data, and outputs the correction data that is generated on the basis of the correction amount, in accordance with the interpolation data outputted by the interpolation unit.
5. The numerical control device according to claim 2 , wherein
the tool data includes a coordination value at the cutting start point on a blade edge of the tool and a coordination value at least one point, on the blade edge, which is different from the cutting start point, and
the correction unit generates the correction data on the basis of a difference between the coordination value at the cutting start point on the blade edge of the tool and the coordination value at the point, on the blade edge, which is different from the cutting start point.
6. The numerical control device according to claim 2 , wherein the correction unit calculates a correction amount for correcting a position of a cutting point at which the workpiece perpendicularly comes into contact with the blade edge of the tool on the basis of the inclination of the blade edge of the tool, which is calculated on the basis of the tool data, and outputs the correction data that is generated on the basis of the correction amount, in accordance with the interpolation data outputted by the interpolation unit.
7. The numerical control device according to claim 3 , wherein the correction unit calculates a correction amount for correcting a position of a cutting point at which the workpiece perpendicularly comes into contact with the blade edge of the tool on the basis of the inclination of the blade edge of the tool, which is calculated on the basis of the tool data, and outputs the correction data that is generated on the basis of the correction amount, in accordance with the interpolation data outputted by the interpolation unit.
8. The numerical control device according to claim 5 , wherein the correction unit calculates a correction amount for correcting a position of a cutting point at which the workpiece perpendicularly comes into contact with the blade edge of the tool on the basis of the inclination of the blade edge of the tool, which is calculated on the basis of the tool data, and outputs the correction data that is generated on the basis of the correction amount, in accordance with the interpolation data outputted by the interpolation unit.