NUMERICAL CONTROLLER

摘要

A numerical controller employs interpolation to control a tool along the profile of the work that is to be machined. The radial offset of the cutting tool is performed at high speeds even during the involute interpolation. Therefore, the involute curve is approximated by an arc that is set depending upon the crossing angle of the machining loci at an instruction point at which the machining is instructed to be started. Abstract A numerical control apparatus according to the invention is 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 even when involute interpolation is carried out, an involute curve is approximated by a circular arc set in dependence upon the intersection angle of a machining trajectory at a command point commanding the start of machining.