Manufacturing method of joined body

A manufacturing method for manufacturing a joined body by joining a first member and a second member, the first member having a hollow portion formed on an end surface thereof, the second member having a projecting portion to be fitted into the hollow portion and a flange portion provided so as to extend radially outward from the projecting portion, the manufacturing method comprising:

• a first joining step of generating frictional heat between the end surface of the first member and the flange portion of the second member by relatively rotating the first member and the second member about a rotation axis in a state in which the hollow portion and the projecting portion are fitted with a predetermined fitting clearance, and by bringing a part of the end surface of the first member into contact with a contact portion of the flange portion of the second member to form a contact part;
• and
• a second joining step of joining the end surface of the first member and the flange portion of the second member by relatively moving the first member and the second member along the rotation axis in a direction approaching each other in a state in which the relative rotation speed between the first member and the second member is lower than that in the first joining step, wherein
• the first member includes an inclined inner peripheral surface having an inner diameter that decreases as a distance from the end surface of the first member along the rotation axis increases, the inclined inner peripheral surface of the first member forming the hollow portion, and
• in the second joining step, flowing material, which plastically flows from the contact part between the part of the end surface of the first member and the contact portion of the flange portion of the second member that contact each other, fills in the fitting clearance from an end thereof located at a root side of the projecting portion until a tip portion of the flowing material reaches a region of the inclined inner peripheral surface in the rotation axial direction, thereby joining the first member with a non-contact portion of the flange portion facing the fitting clearance by the flowing material and joining the first member with the projecting portion by the flowing material.