MACHINING METHOD OF MACHINE TOOL

摘要

PROBLEM TO BE SOLVED: To secure machining accuracy constant by estimating a variation in thermal displacement, and determining machining starting time. SOLUTION: A saturation time thermal displacement quantity and a thermal displacement time constant with every required main spindle rotating speed are prestored. After instruction for changing a main spindle rotating speed, when detecting a change in the rotating speed, the saturation time thermal displacement quantity before changing the rotating speed is calculated, and a counter is started. The saturation time thermal displacement quantity and the thermal displacement time constant after changing the rotating speed at an instructed rotating speed are calculated. An allowable value of a preset machining dimension is compared with a variation (AS-ESTO) in thermal displacement at rotating speed instructing time, and when a value of (AS-ESTO) is smaller than the allowable value, machining is performed as it is, when the value is larger than the allowable value, converging time converged within the allowable value is determined, and the machining is made to stand by in the converging time by a machining stopping instruction. COPYRIGHT: (C)2004,JPO&NCIPI