Warm-up control system for machine tool

Abstract

A warm-up control system for a machine tool drives a spindle motor for rotating a main spindle of the machine tool before starting machining, thereby performing a warm-up operation, and acquires a spindle motor load value that is variable by heat generated during the warm-up operation. The warm-up operation is ended when the acquired spindle motor load value becomes substantially equal to a preset working reference load value. The cutting capacity of the main spindle can be improved by this warm-up operation.

1 . A warm-up control system for a machine tool, comprising:
 a warm-up operation executing unit configured to drive a spindle motor for rotating a main spindle of the machine tool before starting machining, thereby performing a warm-up operation;   a spindle motor load value acquiring unit configured to acquire a spindle motor load value variable by heat generated during the warm-up operation of the warm-up operation executing unit;   a comparison unit configured to compare the spindle motor load value acquired by the spindle motor load value acquiring unit with a preset working reference load value; and   a warm-up operation ending unit configured to end the warm-up operation when it is determined as a result of the comparison by the comparison unit that the difference between the spindle motor load value and the preset working reference load value is within a predetermined range.   
     
     
         2 . The warm-up control system for a machine tool according to  claim 1 , wherein the warm-up operation comprises acceleration and deceleration of the main spindle and steady-state rotation of the main spindle achieved by driving the spindle motor. 
     
     
         3 . The warm-up control system for a machine tool according to  claim 1 , wherein the spindle motor load value is a value of current or a load meter value obtained from the spindle motor. 
     
     
         4 . The warm-up control system for a machine tool according to  claim 1 , further comprising a reference load value setting unit capable of setting a plurality of the working reference load values and a reference load value selection unit configured to select one reference load value to be used for the comparison in the comparison unit, from among the reference load values set in the reference load value setting unit. 
     
     
         5 . The warm-up control system for a machine tool according to  claim 1 , further comprising a warm-up operation end informing unit configured to inform of an end of the warm-up operation when the warm-up operation is ended by the warm-up operation ending unit. 
     
     
         6 . The warm-up control system for a machine tool according to  claim 1 , further comprising a machining starting unit configured to automatically start the machining when the warm-up operation is ended by the warm-up operation ending unit.