| 摘要 |
PURPOSE:To enable the rolling of a wire to improve its productivity, by polygonally shaping the cross section of the tapered portion of the wire, from which a tapered coiled spring is made, so that each side of the cross section is expanded as an arc. CONSTITUTION:A wire 1 comprises a central large-diameter portion 2, both end small-diameter portions 3, 4 and tapered portions 5, 6. The cross section of the small-diameter portions 3, 4 and the tapered portions 5, 6 is polygonally shaped so that each side of the cross section is expanded as an arc. The tapered portions 5, 6 are provided by rolling the wire 1. According to this constitution, the productivity and material yield of the wire 1 are improved. The rolled wire 1 is coiled to manufacture a tapered coiled spring at low cost. |
