Patent ID: 6934601

Claim:
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, comprising: component converting matrix·angle-addition value forming means for converting CL (cutter location) data composed of tool control point vector data and tool axis vector data, calculated along a machining direction on a workpiece coordinate system on which a curved surface is defined by a host computer into components on a normal coordinate system for operating said simultaneous multiple-axis control NC machine on the basis of the machine configuration of said simultaneous multiple-axis control NC machine; component converting means for converting from the workpiece coordinate system to the normal coordinate system; second angle forming means for forming second angles of a second rotary axis on the normal coordinate system; second angle compensating means for forming a continuous angle distribution from a distribution of the second angles; first angle forming means for forming first angles of a first rotary axes on a coordinate system rotated by the second angles at the second rotary axis; first angle compensating means for forming a continuous angle distribution from a distribution of the first angles; machine coordinate transformation matrix forming means for obtaining a matrix for converting the tool control point vectors on the workpiece coordinate system into a machine coordinate system by using said first angles and said second angles; machine coordinate converting means for converting the tool control point vectors into the machine coordinate system by using said machine coordinate transforming matrix; means for converting data on the machine coordinate system to NC data; and means for transmitting said NC data to said numerical control unit.