新転造法の提案と加工実験--ねじ状工具よるクラッチハブ部品のスプライン転造Ⅰ

摘要

Based on previous studies, deep-drawn cups with trapezoidal splines are successfully formed by rolling of two-dies-plunge-feed type, but the rolling process has to be divided into two stages to ensure the required accuracy of tooth trace. In this study, authors propose a new method of spline rolling for clutch hubs using a form rolling machine of crossed axis type. A screw-shaped tool with a rack-shaped tooth profile is used. A deep-drawn cup is fed axially during rolling and an involute spline is formed on the sidewall of the workpiece, which resembles the generating motion of gear bobbing. It is experimentally shown that involute clutch hubs can be successfully formed by only one rolling pass. The effective whole depth of the involute spline is determined. Although the tooth profiles on both sides become slightly convex, they are within the target accuracy. The tooth trace curves on both sides are fairly flat and satisfy the desired level in the same degree as the commercial products of the clutch hubs formed by the Grob or press method.