Hitachi, Ltd.

Hitachi Software Engineering Company, Ltd.

Other

Tamotsu Harihara

Osamu Chiba

Hiroshi Arai

Nobuhisa Kanamaru

Junichi Hirai

Masaaki Takahashi

Shunsuke Minami

When creating other tool path from two tool paths for cutting a work accurately and efficiently, the data on the first tool path is composed of a position vector and a direction vector of a tool for use when the work is cut while moving the tool. The data on the second tool path is composed of a position vector and a direction vector of the tool for use when the work, which has been cut according to the first tool path, is further cut. A computer uses the first tool path data and second tool path data to calculate a position vector and a direction vector of a medium tool path that is between the first tool path and second tool path.

Apparatus and method for creating tool path

A numerically controlled curved-surface machining unit equipped with three linearly moving axes and, at least, one rotary axis, including a simultaneous multiple-axis control NC machine numerically controlled by a numerical control unit with a numerical control NURBS interpolation function. The unit enables reading, as CL (cutter location) data, tool control point vector data and tool axis vector data, along a machining direction on a workpiece coordinate system for a curved surface, obtaining feed rates therefor, and calculation by conversion of the CL data into position vectors of three linear axes on a machine coordinate system, rotation angles and feed rates on the machine coordinate system so as to operate the simultaneous multiple-axis control NC machine on the basis of a machine configuration of the simultaneous multiple-axis control NC machine. The unit forms at least one NURBS curve having continuous curvature, calculates data therefor and converts the NURBS curve into NC data for NURBS interpolation.

Numerically controlled curved surface machining unit

A numerically controlled curved-surface machining unit comprises a component converting matrix&#xb7;angle-addition value forming function of converting CL (cutter location) data into components on a normal coordinate system on the basis of the machine configuration of the simultaneous multiple-axis control NC machine, a component converting function of converting from the workpiece coordinate system to the normal coordinate system, a function of forming second angles of a second rotary axis on the normal coordinate system, a compensating function of forming a continuous angle distribution from a distribution of the second angles, a function of forming first angles of a first rotary axis on a coordinate system rotated by the second angles at the second rotary axis, a compensating function of forming a continuous angle distribution from a distribution of the first angles, a machine coordinate transformation matrix forming function of obtaining a matrix for converting the tool control point vectors on the workpiece coordinate system into a machine coordinate system by using the first angles and the second angles, and a machine coordinate converting function of converting the tool control point vectors into the machine coordinate system by using the machine coordinate transforming matrix.

Performing NURBS (non-uniform rational B-spline) interpolation machining is performed by reading cutter location (CL) data consisting of a tool control point vector and a tool axis vector on a workpiece coordinate system, converting the CL data into a position vector of three linear axes and a rotation angle on a machine coordinate system in accordance with the machine configuration of a simultaneous multiple-axis NC machine, calculating knot vectors of a NURBS curve with the most suitable chord length on the basis of a position vector of the three linear axes and a rotation angle, calculating a NURBS curve of the three linear axes and one rotary axis using the knot vectors, converting the NURBS curve into NURBS interpolation NC data, converting the feed rate on a workpiece coordinate system into the feed rate per minute on a machine coordinate system, and transmitting NC data to a NC machine.

Growing community of inventors

Fujisawa, Japan

Tamotsu Harihara