Patent ID: 6291959
Filing Date: 2001-09-18
Classification: G05B

Abstract:
A method of controlling a numerically controlled machine tool by performing a numerical control program supplied from a read and interpret unit of a numerical control unit to control a drive means of at least one feed axis via an execution command unit, an interpolation unit and a servo control unit, comprising the steps of:presetting acceleration/deceleration time constants for rapid feed and cutting feed of the feed axis, and data on a predetermined temperature and data on a predetermined heat generation amount tolerable for said drive means of said feed axis;computing a temperature of said drive means based on control data of said numerical control program;determining a heat generation amount tolerable for said drive means in accordance with the computed temperature of said drive means;computing a total amount of heat generation of said drive means within a predetermined time, a rapid feed heat generation amount within a predetermined during a rapid feed operation and a cutting feed heat generation amount within a predetermined time during a cutting feed operation, based on the control data of said numerical control program;comparing each of said computed total heat generation amount within the predetermined time, the rapid feed heat generation amount within the predetermined time and the cutting feed heat generation within the predetermined time with the fore-determined tolerable heat generation amount, respectively; andcontrolling an acceleration/deceleration time constant for at least one of the rapid feed operation and the cutting feed operation of said feed axis in accordance with a result of said comparing step.