Manufacturing method of joined body
A manufacturing method includes a joining step of abutting and joining an end surface of a tube main body and a projecting portion of a head member by frictional welding in a state in which a through hole of the tube main body and the projecting portion of the head member are fitted with a fitting clearance. In the joining step, flow material which is practically flowed from an end surface of the tube main body and the flange portion of the head member is filled in the fitting clearance from the root side until the tip portion is located within the range in the direction of the rotation axis, thereby joining between a non-contact portion and the tube main body and between an inclined inner peripheral surface of the tube main body and an outer peripheral surface of the projecting portion by the flow material.
1. 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.
2. The manufacturing method for the joined body according to claim 1 , wherein
the projecting portion includes;
a cylindrical outer peripheral surface having a uniform outer diameter along the rotation axis; and
an inclined outer peripheral surface provided on a tip end side of the projecting portion than the cylindrical outer peripheral surface, the inclined outer peripheral surface being to be joined to the inclined inner peripheral surface of the hollow portion by the flowing material, and the inclined outer peripheral surface having an outer diameter that decreases as the distance from the flange portion along the rotation axis increases,
the first member further includes a cylindrical inner peripheral surface connected to the end surface of the first member, the cylindrical inner peripheral surface having a uniform inner diameter along the rotation axis, and
in the first joining step, the inclined outer peripheral surface of the projecting portion is accommodated inside the inclined inner peripheral surface of the hollow portion, and a root side clearance formed between the cylindrical inner peripheral surface of the hollow portion and the cylindrical outer peripheral surface of the projecting portion is smaller than a tip end side clearance formed between the inclined inner peripheral surface of the hollow portion and the inclined outer peripheral surface of the projecting portion.
3. The manufacturing method for the joined body according to claim 2 , wherein
the inclined inner peripheral surface is a tapered surface inclined at a predetermined angle with respect to the rotation axis, and
the inclined outer peripheral surface is a tapered surface inclined at the same angle as the inclined inner peripheral surface with respect to the rotation axis.
4. The manufacturing method for the joined body according to claim 1 , wherein
in the first joining step, the contact portion of the flange portion of the second member is brought into contact with the part of the end surface of the first member, and an opposing clearance is formed between a clearance portion provided on the flange portion at a position radially outward of the contact portion and an other part of the end surface of the first member, the clearance portion being separated from the end surface of the first member, and
in the second joining step, the end surface of the first member and the clearance portion are joined by the flowing material plastically flowing 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 so as to fill in the opposing clearance.
5. The manufacturing method for the joined body according to claim 4 , wherein
the flange portion includes a flange inclined surface on which the contact portion is provided, the flange inclined surface being continuous with an outer peripheral surface of the projecting portion, the flange inclined surface being inclined with respect to the rotation axis, and
an inclined end surface is provided on the end surface of the first member, the inclined end surface being formed in a shape corresponding to the flange inclined surface, the inclined end surface being to be in contact with the contact portion to form the contact part.
6. The manufacturing method for the joined body according to claim 4 , wherein
the flange portion includes a flange vertical surface formed perpendicularly to the rotation axis, the contact portion being provided on the flange vertical surface,
the end surface of the first member is provided with a vertical end surface formed perpendicularly to the rotation axis and being to be in contact with the contact portion,
at least one of the clearance portion of the flange portion and the other part of the end surface of the first member facing the clearance portion is formed to be inclined with respect to the rotation axis so as to form the opposing clearance with being separate from the other.