Abstract: Two members 10 and 20 are welded together by cutting a groove 41 having a determined cross-sectional shape using a cutting tool 60 along the abutted portion between the two members 10 and 20, inserting a filler member 30 substantially having the same cross-sectional shape to the groove so as to substantially eliminate the gap at the abutted portion, temporarily welding together the projections 12, 22 and the filler member 30, and thereafter, friction stir welding the members 10, 20 and the filler member 30 together completely using a rotary tool 81.

Abstract: A cutter 20 cuts the butted portion between two members 11 and 12 so as to form a groove 13 to the butted portion. 23 is an optical sensor for guiding the cutter 20 to a center of the butted portion of the two members. 21 is a cover that covers the periphery around the cutter. Chips enter the cover 21 and are accumulated therein. 31 is a filling material to be inserted to the groove 13. 33 is a pressure roller preventing the filling material from popping out of the groove 13 during friction stir welding. 41 is a friction stir welding tool for welding the members 11, 12 and the filling material 13. 51 is an air blowout nozzle for blowing air via the proximity of the cutter 20 toward the groove. 52 is another air blowout nozzle disposed at the rear of the cover for blowing air toward the groove 13.

Abstract: A rotary tool (140) is relatively moved against members (30, 30) to be welded so as to perform friction stir welding of said members, while blades (145) mounted on the rotary tool (140) and a rotary brush (220) are used to cut the welded portion, and swarfs on the cut surface are removed through a suction opening (225), before medium liquid is supplied on said cut surface through a supply opening (240). Next, an inspection roller (250) is rotated on the surface of the welded portion for inspection. A probe (251) is provided within the roller (250). Upon detecting a defect, paint is applied to the position of defect by a marking device (270). Thereafter, based on said marking, the joint portion is cut and repaired by welding.

Abstract: Two members 10 and 20 are welded together by cutting a groove 41 having a determined cross-sectional shape using a cutting tool 60 along the abutted portion between the two members 10 and 20, inserting a filler member 30 substantially having the same cross-sectional shape to the groove so as to substantially eliminate the gap at the abutted portion, temporarily welding together the projections 12, 22 and the filler member 30, and thereafter, friction stir welding the members 10, 20 and the filler member 30 together completely using a rotary tool 81.

Abstract: A rotary tool 140 is relatively moved against members 30, 30 to be welded so as to perform friction stir welding of said members, while blades 145 mounted on the rotary tool 140 and a rotary brush 220 are used to cut the welded portion, and swarfs on the cut surface are removed through a suction opening 225, before medium liquid is supplied on said cut surface through a supply opening 240. Next, an inspection roller 250 is rotated on the surface of the welded portion for inspection. A probe 251 is provided within the roller 250. Upon detecting defect, paint is applied to the position of defect by a marking device 270. Thereafter, based on said marking, the joint portion is cut and repaired by welding.