To provide a method for measuring the number of washers capable of compensating an error in a crushing amount of the washers and accurately determining whether the number of washers used is appropriate.
The method for measuring the number of washers at the tightening of a bolt to a tightening object member includes steps of seating the bolt, the washers, and the tightening object member by turning the bolt; completing tightening while crushing the washers by turning the bolt further until predetermined torque is generated; measuring thicknesses of the washers at the completion of tightening; reversely calculating crushing distances of the washers based on a predetermined turning angle and thread pitches of the bolt; calculating the thicknesses of the washers when seated by adding the thicknesses and crushing distances of the washers at the completion of tightening; calculating upper-limit and lower-limit thresholds of the thicknesses of the washers by adding and subtracting thickness variation tolerances of the washers to and from thickness specification values of the washers; and determining that the values are accepted if the thicknesses of the washers at the seating are within limits of the upper-limit and lower-limit thresholds, and rejected if the thicknesses of the washers at the seating are beyond the limits of the thresholds.
| JP3079787 | SCREWS CLAMPING DEVICE |
KITAJIMA YUKI
KAMIMURA MASAHIRO
SHISHIKURA RIKIYA
