TOOL BREAKAGE DETECTING METHOD

摘要

A breakage detecting device is mounted so that the position of the breakage detecting device in a direction parallel to an axial moving path of a spindle is unchanged. The breakage detecting device has a sensing element movable through a path that intersects the axial moving path of the spindle. If the sensing element comes into contact with a tip portion of a tool held by the spindle during the movement of the sensing element, it is judged that the tool held by the spindle has not been broken. Conversely, if the sensing element does not contact the tool, it is judged that the tool has been broken.