Cylindrical interpolation system

Abstract

A cylindrical interpolation system for machining a cylindrical surface of a cylindrical workpiece, wherein a tool diameter correcting means (104) obtains a tool center path by calculating a tool diameter offset vector for a machining shape specified with reference to an assumed orthogonal coordinate system, and an interpolating means (107) interpolates the tool center path and outputs an interpolation pulse (PCyi) related to an assumed linear axis and an interpolation pulse (PZi) related to a cylindrical axis. To effect a reverse conversion from the assumed orthogonal coordinate system to the cylindrical coordinate system, a pulse converting means (108) converts the interpolation pulse (PCyi) into an interpolation pulse (PCi) for rotating the rotary axis. A block-start correction component calculating means (105) and synchronous correction component calculating means (109) calculate correction components (Vcy, .DELTA.Vcy), and these correction components (Vcy, .DELTA.Vcy) are interpolated by a block-start correction component interpolating means (106) and synchronous correction component interpolating means (110), and added to the interpolation pulse (PCi) for rotating the rotary axis. As a result, the tool cutting surface can be always located immediately above the axis of rotation of the workpiece, and the side surface being machined is at a right angle to the cylindrical surface of the workpiece.

Dependencies are inferred from the claim text.