SCREW MEASUREMENT METHOD, PROBE FOR MEASURING SCREW, AND SCREW MEASUREMENT DEVICE USING IT

摘要

PROBLEM TO BE SOLVED: To provide a screw measurement device for automatically and accurately measuring the effective diameter of female screws. SOLUTION: The scrw measurement device 10 comprises: an inside size measurement mechanism 30 for measuring inside size information DWof the female screws 16 by bringing a stylus edge sphere 22 having diameters 2r selected in response to pitches P of the female screws 16 being measuring objects set on a coordinate measurement machine body 12 in contact with screw grooves of the female screws 16; and an effective diameter calculation means 32 for finding effective diameter information Deof the female screws 16 by an effective diameter operational expression of De=DW+2r×cosec(α/2)-(P/2)×cot(α/2) from diameter information 2r of the stylus edge sphere 22, thread angle informationαand pitch information P of the female screws 16. COPYRIGHT: (C)2007,JPO&INPIT