FRICTION STIR WELDING DEVICE, WELDING TOOL, AND FRICTION STIR WELDING METHOD

PROBLEM TO BE SOLVED: To provide a friction stir welding device by which the strength of the welded object subjected to welding and the welding strength of each welded member can be improved. SOLUTION: The device comprises a tool angular displacement driving means of allowing a tool holder to angular displacement driving around an angular displacement axis. The object 21 to be welded is sufficiently stirred by a welding tool 20, and, thereafter, the tool holder is separated from the object 21 in a state where the tool holder is subjected to angular displacement around an angular displacement axis. Thus, in the welded part of one member 21a, shape is made to differ between a transmission region 123 where force is transmitted and a non-transmission region 124 where force is not transmitted. In this way, the strength of the object 21 can be improved. Further, the welding tool 20 is swung in a state of being immersed in the object to be welded, so that a stirring region 21c can be increased, and the welding strength of the welded members can be improved. COPYRIGHT: (C)2004,JPO