| 摘要 |
PROBLEM TO BE SOLVED: To diminish a ratio of flatness to shorten a closely contact length as well as allowing a coil spring to receive stably a load in a closely-contact state and besides to make it possible to further improve uniformity of stress distribution by attaining a continuity of a circumferential stress dispersion of a cross-sectional area. SOLUTION: There is provided a coil spring 1 in which with respect to a cross-sectional peripheral area of a spring wire 3 to be coiled, a portion 7 of the outer diametrical side of a coil or a portion 5 of the inner diametrical side of the coil is made into a semi-circular form represented by x<SP>2</SP>+y<SP>2</SP>=b<SP>2</SP>with the major axis=a, minor axis=b, and the portion of the inner diametrical side 5 or outer diametrical side 7 of the coil is made into a noncircular form represented by (x/a)<SP>α</SP>+(y/b)<SP>α</SP>=1 and then a value of theαis defined as a range of 1.85 to 2.45. The coil spring 1 is provided with flat surfaces 9, 11 against which a coil portion adjacent to the four directions of a coil axis line 4 can abut between the portions 5, 7 of the inner and outer diametrical sides of the coil of a cross-sectional peripheral form in the coil wire 3. COPYRIGHT: (C)2008,JPO&INPIT |
