MEASURING APPARATUS FOR LEAD ERROR OF SCREWTYPE CUTTING TOOL BY NONCONTACTING TYPE OPTICAL FILLER

摘要

PURPOSE:To improve accuracy and to measure the lead errors of a screw type cutting tool continuously at a real time by using a noncontacting type optical detector. CONSTITUTION:A gear hob 7 to be measured is rotated around a shaft 7a by a driving arm 9. The angle L of rotation is detected by a rotary encoder 13. A moving board 4 moves in the direction of A along a fixing board 1 at a sending speed equal to the leading pitch of a gear 7 in accordance with the rotation of the shaft 7a and the moving distance E is detected by an interference type measuring instrument consisting of a laser source 15, three mirror sets 20-22 and a photodetector 26. The position Ve of a cutting tooth of a gear 7 is detected by a detector 5 for the rotational angle of the cutting tooth from the reflected light of the cutting tooth. The extent of movement lL of a flank image is detected by an optical filler mechanism 6 from the quantity of light of the projected image of the screw. A lead error epsilon is obtained by finding a sending error DELTAE=E-L and adding the value of lL in every Ve input, i.e. epsilon-DELTAE to the found sending error.