Tool breakage identification unit in machine tool - judges tool to be broken if detection element is not in contact with tip of tool after holding tool spindle during axial movement for tool exchange at intersection with detection element.

摘要

The spindle movement path is parallel to the rotational axis of the spindle (56) for exchange of the tool held by the spindle by a tool from a tool magazine. The tool breakage identification includes a breakage identification unit (112) with an identification element (116), which is movable in a direction intersecting the axial movement path. so that the position of the identification unit is unaltered in a direction parallel to the axial movement path. The spindle is held during the axial movement for changing the tool at a position, where a tip section of the tool is at an intersection between a location of the detection element and the axial movement path, if the held tool is unbroken. The detection element is moved from a position remote from the axial path, to a position where the detection element makes contact with the tip section of the tool if the tool is not broken. The tool is then judged to be broken if the detection element is not in contact with the tip section of the tool. ADVANTAGE - Tool breakage can be quickly identified.