1975 年 41 巻 488 号 p. 919-924
This report describes the trial manufacturing of a screw lead measuring machine with laser interferometer and its characteristics, comparing with the first trial machine. The measuring capacity for a thread length of a screw to be measured is 1 m, while it is 500 mm in the first trial machine. The other characteristics are as follows: (1) The optical system is improved to avoid the back talk of laser. (2) In the electronic circuit, the correction circuit for atmosphere and DA conversion circuit for simultaneous digital and analog recording are added. (3) Beside the function of the measurement of cumulative pitch error, the functions of the measurement of lead error of screws and nuts are added, where the lead error is the combination of cumulative pitch error and cyclic error. (4) The reproducibility of measurement is expressed by a standard deviation as follows: 0.3 μm for the measurement of cumulative pitch error of ground screw having thread length of 800 mm, 0.2 μm for the measurement of lead error of ground screw having thread length of 250 mm and 0.4 μm for the measurement of lead error of cut nut having thread length of 80 mm.