| 摘要 |
<p>A hollow frame member is constituted by joining two face plates 11, 12 in a truss manner by ribs 13, 13A, 13B. The end portions of the face plates are connected by one rib 13A. A face plate 21 of a second hollow frame member 20 is joined at a vicinity of an apex of the truss of the first hollow frame member 10. The face plate 12 of the first hollow frame member 10 is joined at a vicinity of an apex of the truss of the second hollow frame member 20. These joints are made by friction stir joining using a rotating tool 250. The load during friction stir joining is received by the ribs 13A, 13B (13A, 23B). Since this truss structure is provided, a lightweight structure and high rigidity performance can be obtained. <IMAGE></p> |
