TOOL CHECKER FOR AUTOMATIC TOOL CHANGER

PROBLEM TO BE SOLVED: To detect the breakage of various tools with a single photoelectric sensor by providing the photoelectric sensor movably in the axial direction of a tool midway of the moving locus of the tool by a tool change arm, and moving the photoelectric sensor according to the type of the tool so that its optical path crosses the tip section of the tool. SOLUTION: For a tool change, a tool pot 16d holding a tool T to be used next is indexed to a change position, then a tool change arm 17 is rotated 90 deg.CW from the horizontal attitude. A photoelectric sensor 18 having a light emitting element and a light receiving element at one end and the other end of a U-shaped case is provided movably by a moving means 19 midway of a tool moving locus by the tool change arm 17. The servo motor 19a of the moving means 19 is controlled by a controller, the shaft length data of the corresponding tool T are read out from a memory, the photoelectric sensor 18 is moved so that the optical path (b) between the light emitting element and the light receiving element crosses the tip section of the tool T, and the breakage of the tool T is detected.