Patent Number: 6,305,866

Title: Structure joined by friction stir welding

Abstract: A friction stir welding technique which avoids occurrence of a dent, in ajoining region, extending to a level beneath the joined surfaces. At endportions of the frame members to be joined, at the joining region,thickened parts which project toward the rotary body joining tool areprovided. Two adjoining thickened parts, of adjacent members to be joined,can form a trapezoid shape. The rotary body joining tool has asmall-diameter tip portion and a larger diameter portion. The rotary bodyjoining tool is inserted in the thickened parts. In a state where therotary body joining tool has been inserted small-diameter tip end first,to a level where the larger diameter portion of the rotary body joiningtool overlaps the thickened part but does not extend below the uppersurface of the non-thickened surfaces of the members joined, the rotarybody is rotated and moved along the joining region. Even when a gap existsbetween two thickened parts, a desirable joining can be carried out. Afterthe joining, the remaining parts of the thickened parts can be machined soas to form a smooth surface.

Inventors: Aota; Kinya (Hitachi, JP), Ezumi; Masakuni (Kudamatsu, JP), Ishimaru; Yasuo (Kudamatsu, JP), Okamura; Hisanori (Ibaraki, JP), Funyuu; Isao (Takahagi, JP), Satou; Akihiro (Kudamatsu, JP)

Assignee:

International Classification:

Expiration Date: 10/23/2013