Machine tool with fault detection

摘要

A machine tool includes a spindle having a cutting tool for cutting a workpiece. For fault detection, a control unit of the machine tool detects a value representing a torque applied on the spindle while the spindle is stopped in a state the cutting tool is engaged with the workpiece. The control unit further compares the detected value (representing a torque) with a predetermined threshold thereby to determine that a fault has occurs. Since the detection of the value representing a torque is performed while the spindle is stopped, the detection is free from the effects of acceleration or deceleration of the spindle.