| 摘要 |
PROBLEM TO BE SOLVED: To provide a watertight structure capable of connecting securely and for a long time extrusion moldings made of mutual aluminum alloy or plate materials while minimizing the previous processes or works. SOLUTION: An extrusion molding 2 made of aluminum alloy is provided with a horizontal flat plate part 3, and a pair of projected streaks 4, 4 provided symmetrically on the underside thereof; and the ends of the flanges 6, 6 projected from both the right and left ends of the flat plate parts 3 are integrally provided with a slightly thick end parts 8, 8, and such a plurality of end parts 8 of the extrusion molding 2 are get butted against each other to form a butt part 9. An joining line W shallow in depth is formed along the surface of the butt part 9 by the frictional stirring junction using a tool including a friction pin and a surface pressing part, so that the extrusion molds 2 are metallically joined to each other. Since the surface of the joining line W is flat, after- working such as grinding is almost unnecessary, and a plane watertight structure 1 can be securely and for a long time maintained by such a joining line W. |
