Abstract: Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces, structural body formed. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip end first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region.

Abstract: A welding bead 50 is formed along to a jointing potion 40 using friction stir welding on a first frame member 20 and a second frame member 30, each of which is a hollow extruded molded base member made of an aluminum alloy A6N01 material. When a defect exists in this welding bead 50, the welding bead including this defect is moved by a grinding processing and then a mending zone is formed. In this mending zone, a mending bead is formed using TIG welding. The welding rod used in this TIG welding is made of the same material as the base member of the frame member, and so the composition of the welding bead is formed homogeneously. In the friction stir welding portion, a hairline processing is performed, so that a surface having a beautiful appearance, in which a boundary between the frame members and traces of the defect are inconspicuous, can be obtained.

Abstract: Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip and first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out.

Abstract: Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip and first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out.

Abstract: Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip and first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out.

Abstract: Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip and first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out.

Abstract: The end of a face plate 11 of a hollow member 10 is abutted against the end of a face plate of a hollow member 20. The end of a face plate 21 is stacked to a protrusion 15. A small-diameter portion 52 of a rotary tool 50 is inserted to the abutted area, and the tool 50 is moved along the abutted region while being rotated in the right direction observed from the large-diameter portion 51. The direction of movement is from the front of the drawing of FIG. 1 toward the far end thereof. In FIG. 1, the pressure of mobilized metal is greater in the right side of the axial center of the rotary tool. The thickness of the member from the tip of the inserted small-diameter portion 51 to the hollow areas 10b and 10a is thicker at the right side. Accordingly, the thickness of the member is greater at the right side of the tool where the pressure is higher, thus preventing metal from flowing out into the hollow region 10a.

Abstract: Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip and first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out.

Abstract: The rotary tools are disposed to weld along two spaced welding lines. The two rotary tools are inserted into respective welding joints and moved at the same time along the respective welding lines. At a position P1 of a portion of a window one rotary tool is withdrawn from the welding joint so that the friction stir welding on that welding joint is stopped although the welding tool continues to move. At a position P3, the rotary tools are gradually withdrawn from their respective welding joints while they continue to move along the welding line. At a position P4, the movement of the rotary tools along the respective welding lines is stopped, the rotary tools are completely withdrawn and the welding is stopped. Next, the rotary tools are inserted into the respective welding joints once again and movement thereof is started again. An insertion amount of the rotary tools at this time is larger than the insertion amount thereof prior to the stopping of the movement of these rotary tools.

Abstract: A raised portion 32 is provided on an upper face of an end portion of a plate 31 which forms one side of a frame member 30. An end portion of a plate 41 of another frame member 40 is abutted with the plate 31 of the frame member 30. The frame members 30 and 40 are aluminum alloy extruded frame members and the directions of extrusion of the two frame members are orthogonal. A welding padding is carried on an upper face of the plate 41 of the frame member 40. Under this condition, a rotary tool is inserted from above and a friction stir welding is carried out. Accordingly, the padding serves the same function on the plate 41 as the raised portion 32 on the plate 31, so that a good welding can be carried out.

Abstract: The rotary tools are disposed to weld along two spaced welding lines. The two rotary tools are inserted into respective welding joints and moved at the same time along the respective welding lines. At a position P1 of a portion of a window one rotary tool is withdrawn from the welding joint to that the friction stir welding on that welding joint is stopped although the welding tool continues to move. At a position P3, the rotary tools are gradually withdrawn from their respective welding joints while they continue to move along the welding line. At a position P4, the movement of the rotary tools along the respective welding lines is stopped, the rotary tools are completely withdrawn and the welding is stopped. Next, the rotary tools are inserted into the respective welding joints once again and movement thereof is started again. An insertion amount of the rotary tools at this time is larger than the insertion amount thereof prior to the stopping of the movement of these rotary tools.

Abstract: The rotary tools are disposed to weld along two spaced welding lines. The two rotary tools are inserted into respective welding joints and moved at the same time along the respective welding lines. At a position P1 of a portion of a window one rotary tool is withdrawn from the welding joint so that the friction stir welding on that welding joint is stopped although the welding tool continues to move. At a position P3, the rotary tools are gradually withdrawn from their respective welding joints while they continue to move along the welding line. At a position P4, the movement of the rotary tools along the respective welding lines is stopped, the rotary tools are completely withdrawn and the welding is stopped. Next, the rotary tools are inserted into the respective welding joints once again and movement thereof is started again. An insertion amount of the rotary tools at this time is larger than the insertion amount thereof prior to the stopping of the movement of these rotary tools.

Abstract: A raised portion 32 is provided on an upper face of an end portion of a plate 31 which forms one side of a frame member 30. An end portion of a plate 41 of another frame member 40 is abutted with the plate 31 of the frame member 30. The frame members 30 and 40 are aluminum alloy extruded frame members and the direction of extrusion of the two frame members are orthogonal. A welding padding is carried on an upper face of the plate 41 of the frame member 40. Under this condition, a rotary tool is inserted from above and a friction stir welding is carried out. Accordingly, the padding serves the same function on the plate 41 25 the raised portion 32 on the plate 31 so that a good welding can be carried out.

Abstract: A friction stir welding apparatus 1a comprises members 20 and 30 to be subjected to a friction stir welding which members are fixed on a table 5, and a joining welding head 200 which moves in an arrow mark A direction along the table 5. A rotary tool 10 performs the friction stir welding so that a welding bead 50 is formed. A sensor 210 irradiates a light beam 212 on the area to be welded and detects edge portions 24 and 34 of the members, and the welding head 200 is moved and controlled to follow the center of the welded joint. A burr removing cutting means 12 of the rotary tool 10 operates to cut off the burr from the weld, causing chips 60 to be formed. An air jet J injected from an air nozzle is discharged to the outside from a cover 230, whereby entry of the chips 60 into the area of the sensor 210 can be prevented. In a friction stir welding apparatus, the entry of chips into the area of the sensor 210 for detecting a center position where the welding joint is located can be prevented.

Abstract: A friction stir welding technique which avoids occurrence of a dent, in a joining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip end first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out.

Abstract: End portions of face plates 111 and 112 of a frame member 110 are connected by a rib 116A. To protrusion chips 117b1 and 117b2 end portions of face plates 101 and 102 of another frame member 100 are overlapped. The corners between the rib 116A and the rear faces of the face plates 111 and 112 are in the form of a convex circular arc 131 which protrudes into a hollow portion 119 of the frame member 110. Both end portions of the circular arc 131b1 are connected to the rib 116A and the face plates 111 and 112 by two smooth recessed circular arcs 132b1 and 133b1. Accordingly, since a flow-out of metal does not occur from this portion, the cross-section can be small and a light weight structure can be obtained. A structural body formed of hollow frame members which are joined by friction stir welding provides a light weight structure.

Abstract: End portions of face plates 111 and 112 of a frame member 110 are connected by a rib 116A. To protrusion chips 117b1 and 117b2 end portions of face plates 101 and 102 of another frame member 100 are overlapped. The corners between the rib 116A and the rear faces of the face plates 111 and 112 are in the form of a convex circular arc 131 which protrudes into a hollow portion 119 of the frame member 110. Both end portions of the circular arc 131b1 are connected to the rib 116A and the face plates 111 and 112 by two smooth recessed circular arcs 132b1 and 133b1. Accordingly, since a flow-out of metal does not occur from this portion, the cross-section can be small and a light weight structure can be obtained. A structural body formed of hollow frame members which are joined by friction stir welding provides a light weight structure.

Abstract: Rotary tools 340A and 340B are disposed to weld along two joining lines. For this purpose spaced welding lines the two rotary tools are inserted and into respective welding joints moved at the same time along their respective welding lines. At a position P1 of a portion of a window 210, the rotary tool 340A is retreated from the welding joint so that the tool 340 A continues to move friction stir welding on that welding joint is stopped although the welding. At a position P3, the rotary tools 340B are gradually withdrawn from their respective welding joints while they continue to move along the welding line. At a position P4, the moves of the rotary tools 340A and 340B is stopped, the rotary tool 340B is made to retreat and the joining is made to stop. Next, the rotary tools 340A and 340B are inserted and the move are started again. An insertion amount of the rotary tool 340B is larger than an insertion amount during the stop of the move of the rotary tool.

Abstract: Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip and first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out.

Abstract: Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip and first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out.