Two=stage cold extrusion process for gear wheel mfr. - uses die with taper bore to finish rough formed gears

摘要

In the first stage a circular blank (13) is placed in an internally toothed die (11) and the gear teeth are formed by exerting pressure on the blank (13) so that the metal is extruded into the spaces between the teeth of the die. In the second stage, the blank is pressed into a second internally toothed die (21) with a taper bore (22) leading to a parallel bore (23). This method of manufacture has the advantage of producing teeth with radial grain flow.