Development of controlled tapered rolling method for manufacturing tapered leaf spring

摘要

In order to produce Tapered Leaf Spring (TLS), a new Controlled Taper Rolling (CTR) method is developed. This process is a combination of the edge rolling used grooved rolls and the flat rolling. It is very important in this method to predict thedeformation properties such as spread precisely. For the first pass, quadratic equations which relate the reduction in width and the mean thickness increment, is obtained. For the second pass, it was clarified that Ekelund's equation was good agreementwith the experimental values even if the rolling diameter changed from 125 mm to 720mm and the rolling temperature changed from 1073K to 1223K. The actual pass schedule to produce TLS is designed by using the data obtained from these steady sate rolling.It is afraid that there is large difference in the deformation and loading properties between the steady state rolling and the non-steady state rolling such as tapered rolling. However, it was clarified that the spread is not effected and projectedcontact length is effected in tapered rolling. The pass schedule based on the steady state rolling can be applicable and the rolling load and the rolling torque might be predicted by concerning the change of the projected contact length.