Effects of Wire Shape in Bundles and Wire Feeding Conditions on shape of Cold Formed Coil Springs (2nd Report, Theoretical Analysis)

摘要

Effects of the wire shape in bundles and the wire feeding conditions on the shape of formed coils are analyzed theoretically and experimentally, which derives the relations between the reel plane inclination and the shape of the formed coils. In these relations, the effects of combined loads on the yield point load of the wire are considered qualitatively. As a result of the analysis, it is clarified that the shape of the formed coils is not affected by the feeding conditions in case of straight wire. On the other hand, the shape of the formed coils is influenced by the wire shape and the wire feeding conditions in case of curved wires. In other words, the more the feed roller force increases and the smaller spring index becomes, the smaller the shape change of formed coils becomes. Furthermore, it is clarified that the torsion of the formed coils is mainly processed by coiling tools compared with wire shape.