Hollow cam shaft

Abstract

A hollow cam shaft is composed of a hollow shaft having an inner hollow portion and an end piece which is pressure-welded to at least one end of the hollow shaft. The end piece comprises an end member which is pressure-welded to the one end of the hollow shaft and an enclosure member extending from the end member in an axial direction thereof so as to be inserted into the inner hollow portion of the hollow shaft at a time of pressure welding to define an enclosure space in the inner hollow portion of the hollow shaft. The enclosure member comprises a sealing portion having an outer shape substantially the same as an inner shape of the hollow shaft and a connection portion connecting an end surface of the end member of the end piece and the sealing portion so as to define said enclosure space between the enclosure member and the hollow shaft into which a burr generated at the pressure welding time is enclosed.

Dependencies are inferred from the claim text.