DYNAMICALLY TOOL ABRASION COMPENSATING METHOD IN A NUMERICALLY-CONTROLLED MACHINE TOOL

摘要

A method of the invention detects a machining loadacting on a tool during a machining process, computesestimatingly an abrasion quantity of the tool on the basisof the machining load and a tool abrasion characteristicregistered in advance in a memory, and changes automaticallya tool position compensation quantity on the basis of the toolabrasion quantity. The estimating computation of a toolabrasion quantity is performed by, for example, obtaining inadvance a tool abrasion coefficient on the basis of a toolabrasion quantity per unit time in case of taking a mainspindle load current value as a reference machining currentvalue, and integrating for a machining time the product ofa ratio of a main spindle load current value during an actualmachining process to the reference current value and said toolabrasion coefficient.