This paper describes the results of the study and research on ovate wire helical springs which have been jointly conducted by the members of the Japan Society for Spring Research consisting of the engineers from material suppliers, wire and spring producers and automotive manufacturers as well as researchers at Japanese universities.
Attention is focused particularly on two types of wire cross sections, typical elliptical shape and Fuchs' egg-shape. Stresses on these two cross sections were analyzed by numerical calculations within the range of practical specification, and then the results have been compared with those of round wire spring. As a result, it has been found that the elliptical wire spring is superior to Fuchs- egg-shaped one for general application.
Simple designing methods for the both types of wire helical springs have been developed based on the findings from the stress analysis. Also, designing guidelines have been established so that ovate wire helical springs can be redesigned from the basic round wire springs by means of simple calculations, to meet various specific requirements.
Moreover, this paper summarizes the results of survey on manufacturing and evaluation process of wires having ovate cross sections and the springs made of such wires.