Method for manufacturing outer joint member for constant velocity universal joint, shaft member and outer joint member

A method of manufacturing an outer joint member of a constant velocity universal joint, which is constructed by forming, through use of separate members, a cup section having track grooves formed at an inner periphery of the cup section and engageable with torque transmitting elements, and a shaft section formed at a bottom portion of the cup section, and by welding a cup member forming the cup section and a shaft member forming the shaft section,

• the method comprising:
• preparing the cup member of carbon steel, the preparing of the cup member including forging to integrally form a cylindrical portion and a bottom portion, and machining a joining end surface at an outer surface of the bottom portion after the forging;
• preparing the shaft member of carbon steel, the preparing of the shaft member including a preforming step of forging a billet cut from a bar material to form a tapered shape at a portion of the billet, a main forming step of forging, at the portion of the billet having the tapered shape, a step portion and a radially inner side recessed portion at the step portion, and a machining step of machining a joining end surface at the step portion, the joining end surface of the shaft member to be joined to the bottom portion of the cup member;
• bringing the joining end surface of the cup member and the joining end surface of the shaft member into abutment against each other;
• welding the cup member and the shaft member by radiating a beam from an outer side of the cup member to an abutment portion between the cup member and the shaft member in a radial direction of the cup member;
• and
• forming the outer joint member.