One-piece hollow camshafts and process for producing same

Abstract

The invention relates to a hollow camshaft consisting of a metal or metal alloy or plastic which can be cold-formed and heat-treated and has a fiber flow parallel to the exterior contours of the camshaft, and to a method for producing it comprising the steps of: Placing a pipe outlet element and filling it with fluid; Sealing at least the pipe section to be widened; Applying an internal high pressure suitable for widening the pipe section to produce an intermediate product pre-form, wherein, while the internal high pressure is applied, the hollow pipe is compressed against a movable die in the direction of its long axis in such a way that accumulations of material occur at approximately those places where it is intended to create cams; Shaping the intermediate product pre-form into a shape corresponding to a final camshaft shape by means of the internal high pressure shaping method, so that cams are shaped at the desired locations; If necessary, finishing the cams by heat-treatment.

Dependencies are inferred from the claim text.