MANUFACTURING METHOD FOR CONSTANT VELOCITY UNIVERSAL JOINT OUTER JOINT MEMBER AND OUTER JOINT MEMBER

摘要

Provided is a manufacturing method for a constant velocity universal joint outer joint member that comprises a cup part and shaft part made from separate members with the cup member forming the cup part and the shaft member forming the shaft part being welded together, said cup part having an inner circumference in which a track groove for engaging with a torque transmitting element is formed and said shaft part being formed on the bottom part of the cup part. This manufacturing method uses a medium-carbon steel to form the cup member and the shaft member and comprises: preparing, as the cup member, a cup member in which a cylindrical part and a bottom part are integrally formed by forging, after which a weld end face is formed on the outer wall of the bottom part in a machining step; preparing, as the shaft member, a shaft member in which a weld end face to be welded to the bottom part of the cup member is formed in a machining step; and butting the weld end face of the cup member to the weld end face of the shaft member and welding together by focusing a beam from the outside of the butted parts in the radial direction. The manufacturing method is characterized in that the shaft member has a step part and a radially inner recess part formed thereon by forging from a billet cut from a bar material, the step part being where the weld end face is formed.