Shaping of inner helical spline by cold extrusion

摘要

We have previously proposed a two-step cold extrusion method for internal spur gear shaping. A mandrel specially designed to form the outer diameter of a spur gear in two steps is used to expand the inner diameter of the cylindrical workpiece. In this paper, the shaping of an inner helical spline by this method is reported. The specifications of the helical splines examined are as follows module 1.0. 1.5, 1.75; helix angle 10-30 and number of teeth 10-22. It is shown that almost all the conditions examined produced a completely teethed inner helical spline even with only a few percent area reduction and under quite low compressive stress on the stepped mandrel and the punch.