摘要 |
A coiled spring formed from a wire whose sectional shape is semicircular outside the coil and semielliptical inside the coil, exhibits improved stress distribution when a length L from the center of the semicircle to the surface is in the relation of L0 < L, as compared with L0 of an ellipse expressed by… a/b = 2w/t - 1,… where a is the long diameter and b is the short diameter, and the axial dimension of coil does not exceed t, and the dimension perpendicular to the axial direction does not exceed w. Preferably 1.1 < a/b < 2w/t - 1, |