| 摘要 |
PROBLEM TO BE SOLVED: To friction stir join a gusset and a cross member with sufficient coupling strength.SOLUTION: A notch-shaped joint recessed portion 31 is formed on a gusset side attaching plate portion 25 of a gusset 4, and a joint projecting portion 22 is formed on a cross member side attaching plate portion 17 of a cross member 3. In a combination state in which the gusset side attaching plate portion 25 and the cross member side attaching plate portion 17 are superimposed, the joint projecting portion 22 enters the joint recessed portion 31. In the combination state, an outside surface of the joint projecting portion 22 opposes to an inside surface of the joint recessed portion 31 to approach or contact with each other, and a projecting portion top surface 33 is disposed on the generally same surface as an upper surface 27 of the gusset side attaching plate portion 25. The inside surface of the joint recessed portion 31 and the outside surface of the joint projecting portion 22 are linearly joined by friction stir joining along a boundary 35 between the upper surface 27 and the projecting portion top surface 33 in the combination state.SELECTED DRAWING: Figure 1 |
