1991 年 57 巻 4 号 p. 658-663
In the previous papers, authors have clarified the effects of dimensional errors of the parallel movement for balance on the error rate of displacement. Although the correction of the dimensional errors of the springs in length and thickness is necessary for accurate measurement, it is, however, difficult to eliminate the dimensional errors by machining. The authors propose to put a groove on the springs, which modifies the error rate of displacement without eliminating the dimensional errors. Following is concluded through theoretical, experimental and FEM analyses. (1) The groove at the ends of the spring is most effective for modification, while the one at the center of the spring does not contribute to the modification. (2) The modification effect is in proportion to the width and thickness of the groove. (3) In case of the parallel spring movement with four leaf springs, the reinforcing plate reduces the modification effect due to the groove.