METHOD AND APPARATUS FOR SETTING ANGLE POSITION OF WORKPIECE ON MACHINE TOOL BY LASER BEAM

摘要

PURPOSE: To precisely determine an angular position by producing a shaded zone determined by a characteristic amount fluctuating with a rotary angle by shutting off a beam by a part of a workpiece in a zone and rotating the workpiece until the characteristic amount reaches a reference value. CONSTITUTION: Spiral grooves 3a, 3b are provided in a roughly cut drill bit 3 and are arranged in a path of a laser beam F generated by a laser generator 10 to shut it off. The beam F is transmitted in parallel in a plane vertical to an axis XX' and is detected by a laser receive device 11, the receive device 11 supplies a signal S generated by a beam shut off by the drill bit 3 to compare it with a reference signal S1 corresponding to a predetermined angular position of the drill bit 3 in a comparison circuit 12, and a signal D is sent to a terminal 6 of a grinder 1 when it reaches a value of the signal S1. When a control button 4 is pressed when the drill bit 3 is fixed in a mandrel 2, it rotates centered on the axis XX' to generate a fluctuation of the signal S which becomes equal to the reference signal S1 so that the signal D is sent to the terminal 6 in the comparison circuit and the terminal 6 stops the drill bit 3 at the predetermined angular position.