Abstract: The purpose of the present invention is to provide a method that can be easily applied to friction stir welding where the thickness of face plates at one welding portion is different from the thickness of face plates at another welding portion. Three shape members 10, 11, 12 having two butt joint portions are mounted on a jig 15. The face plate 14 of shape member 10 is thick and the face plate 14 of shape member 12 is thin. The protruded height of projection 18 is greater at portion B where surface plates 14 being welded are thin than the protruded height of projection A where surface plates 14 are thick. The depths for inserting rotary tools to shape members 10, 11, 12 for friction stir welding are the same. Friction stir welding is facilitated since the size and insertion depth of all the rotary tools being applied can be the same.

Abstract: There is provided a friction stir welding method for forming a satisfactory weld portion by two steps when members having different thicknesses are butted together and friction stir welded. A first member 10 having a thickness T1 and the second member 20 having a thickness T2, which is smaller than the thickness T1, are placed on a table 40 to form a stepped butt portion 30. In a first step, metal is transferred from the first member 10 to the second member 20 to form a convex substitute portion 150 in the stepped portion by rotatingly moving a columnar tool 100 along the butt portion 30. In a second step, friction stir welding is performed on the convex substitute portion 150 to obtain a satisfactory weld portion 250 by using a friction stir welding tool 200.

Abstract: Face plates 11 and 12 of a hollow shape member 10 are abutted against face plates 21 and 22 of a hollow shape member 20. Grooves 18 formed to said face plates 11 and 12 at the abutted region receive projections 28 formed to said face plates 21 and 22. A connecting plate 14 orthogonal to said face plates 11 and 12 is provided to the hollow shape member 10. There is no connecting plate orthogonal to face plates 21 and 22 disposed on the end of the hollow shape member 20. Friction stir welding heat causes the face plate 21 (22) to move toward the thickness direction of hollow shape members 10 and 20, but such movement is suppressed by the groove 18 and projection 28. Thereby, the abutted region is welded flatly. Since the hollow shape member 20 requires no connecting plate corresponding to plate 14, the welded members are light in weight.

Abstract: The purpose of the present invention is to provide a method that can be easily applied to friction stir welding where the thickness of face plates at one welding portion is different from the thickness of face plates at another welding portion. Three shape members 10, 11, 12 having two butt joint portions are mounted on a jig 15. The face plate 14 of shape member 10 is thick and the face plate 14 of shape member 12 is thin. The protruded height of projection 18 is greater at portion B where surface plates 14 being welded are thin than the protruded height of projection A where surface plates 14 are thick. The depths for inserting rotary tools to shape members 10, 11, 12 for friction stir welding are the same. Friction stir welding is facilitated since the size and insertion depth of all the rotary tools being applied can be the same.

Abstract: The purpose of the present invention is to provide a method that can be easily applied to friction stir welding where the thickness of face plates at one welding portion is different from the thickness of face plates at another welding portion. Three shape members 10, 11, 12 having two butt joint portions are mounted on a jig 15. The face plate 14 of shape member 10 is thick and the face plate 14 of shape member 12 is thin. The protruded height of projection 18 is greater at portion B where surface plates 14 being welded are thin than the protruded height of projection A where surface plates 14 are thick. The depths for inserting rotary tools to shape members 10, 11, 12 for friction stir welding are the same. Friction stir welding is facilitated since the size and insertion depth of all the rotary tools being applied can be the same.

Abstract: The invention provides a friction stir welding method with less weld defects upon welding a butted portion between a first member and a second member. A first member 10 is butted against a second member 20, and then a round-bar buildup member 30 is pressed against the upper surface of the butted portion and rotated to weld a buildup bead 35 thereon. The buildup bead corresponds to a projection of the prior art friction stir welding method. Next, a pin 51 of the rotary tool 50 is inserted to the butted portion to perform friction stir welding. According to this method, the buildup bead 35 corresponds to a projection and fills the space formed to the butted portion, so a good weld joint is formed and the generation of defects is suppressed.

Abstract: The end of a hollow member 10 is abutted against the end of a hollow member 20. The end of a face plate 21 is supported on a protrusion 15. A small-diameter portion 52 of a rotary tool 50 is inserted into the abutted area, and the tool 50 is moved along the abutted region while being rotated in a clockwise direction as observed from the large-diameter potion 51. Thus, the pressure of mobilized metal is greater on 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 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 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: Two members 11 and 12 are butted against each other, and the butted portion is cut with a cutter 20 to form a slit 14 thereto, and a filler member 21 is inserted to slit 14 using rollers 22, 23 and 25. Then, friction stir welding is performed to weld filler member 21 and two member 11 and 12 disposed on both sides thereof using a rotary tool 35, and the position of a gap formed between an end of filler member 21 at the upstream side in the rotating direction of rotary tool 35 and one member 11b at the upstream side in the rotating direction is detected using an optical sensor 35. Then, half the width of filler member 21 is added to the detected position, and the calculated position is set as the position of the rotary tool 35.

Abstract: A cutting tool 60 cuts along the butted portion between two members 10, 20. A filling material 30 is inserted to the gap 40 formed by said cutting, and a roller 70 presses protrusions 12 and 22 to crimp said protrusions 12 and 22 so as to fix said filling material to position. Next, friction stir welding is performed to the protrusions 12, 22 and the filling material 30 using a rotary tool 80. In another example, instead of cutting, the filling material can be welded and filled to the gap. In yet another example, cutting can be performed so as to approximate the two members before performing the friction stir welding step.

Abstract: The friction stir welding technique disclosed 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, thickened parts, which project toward the rotary body joining tool, are provided. The Two adjoining thickened parts form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion, and is inserted in the thickened parts. When 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, 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. After the joining, the remaining parts of the thickened parts can be machined to form a smooth surface.

Abstract: The purpose of the present invention is to provide a method that can be easily applied to friction stir welding where the thickness of face plates at one welding portion is different from the thickness of face plates at another welding portion. Three shape members 10, 11, 12 having two butt joint portions are mounted on a jig 15. The face plate 14 of shape member 10 is thick and the face plate 14 of shape member 12 is thin. The protruded height of projection 18 is greater at portion B where surface plates 14 being welded are thin than the protruded height of projection A where surface plates 14 are thick. The depths for inserting rotary tools to shape members 10, 11, 12 for friction stir welding are the same. Friction stir welding is facilitated since the size and insertion depth of all the rotary tools being applied can be the same.

Abstract: A cutting tool 60 cuts along the butted portion between two members 10, 20. A filling material 30 is inserted to the gap 40 formed by said cutting, and a roller 70 presses protrusions 12 and 22 to crimp said protrusions 12 and 22 so as to fix said filling material to position. Next, friction stir welding is performed to the protrusions 12, 22 and the filling material 30 using a rotary tool 80. In another example, instead of cutting, the filling material can be welded and filled to the gap. In yet another example, cutting can be performed so as to approximate the two members before performing the friction stir welding step.

Abstract: Two members 11 and 12 are butted against each other, and the butted portion is cut with a cutter 20 to form a slit 14 thereto, and a filler member 21 is inserted to slit 14 using rollers 22, 23 and 25. Then, friction stir welding is performed to weld filler member 21 and two member 11 and 12 disposed on both sides thereof using a rotary tool 35, and the position of a gap formed between an end of filler member 21 at the upstream side in the rotating direction of rotary tool 35 and one member 11b at the upstream side in the rotating direction is detected using an optical sensor 35. Then, half the width of filler member 21 is added to the detected position, and the calculated position is set as the position of the rotary tool 35.

Abstract: Grooves 18 formed to face plates 11 and 12 of a hollow shape member 10 at an abutted region with hollow shape member 20 receive projections 28 formed to face plates 21 and 22 of member 20. A connecting plate 14 orthogonal to the face plates 11 and 12 is provided to the hollow shape member 10. There is no connecting plate orthogonal to face plates 21 and 22 disposed on the end of the hollow shape member 20. Friction stir welding heat causes the face plate 21(22) to wove toward the thickness direction of hollow shape members 10 and 20, but such movement is suppressed by the groove 18 and projection 28. Thereby, the abutted region is welded flatly.

Abstract: On a main shaft 30 of a numeric control type machine tool, a rotary tool 50 is installed. The main shaft 30 is not inclined in the machine tool. A first member 70 and a second member 76 to be subjected to friction stir welding are fixed on a table 20. Relative to an axial center of the rotary tool 50, a non-linear welding portion of the first member 70 and the second member 76 is inclined by inclining the table 20. Then, by rotating the table 20 and relatively moving the portion to be welded into contact with the rotary tool 50, welding of the first member to the second member is carried out according to friction stir welding. The above-stated inclination is the inclination required for the friction stir welding. In this way, welding along a path of ring shape or circular shape (including a circular arc) using friction stir welding can be carried out easily.

Abstract: A rotary tool (200) having on the end surface of a large-diameter portion (210) facing a small-diameter portion (220) grooves (213) formed in arc-like shapes, and performing friction stir weld by inserting the end surface of the large-diameter portion (210) and the small-diameter portion to members and rotating the tool (200). By the rotation, the metal of the members moves along the grooves (213) to the center axis direction of the rotary tool (200). The arc-shaped grooves (213)are formed to curve toward the direction of rotation. Since the metal material of the members is moved toward the center, a good weld is realized even when only one of the members to be welded has a projection, or when a large gap is formed therebetween.

Abstract: A rim member 120 forming an entrance 110 and a plate 11 (21) are friction stir welded by moving a rotary tool 200 along the rim member 120. The rotary tool 120 is tilted along the direction of movement. Welding is started at right block 120R, and when the tool reaches corner portion P5 between the right block 120R and a center block 120C, the tool 200 is pulled out of the rim member 120 and plate 11 (21). Next, the tool is tilted toward the direction of movement along center block 120C. Thereafter, the tool is lowered and inserted to position, and friction stir welding is restarted. According to the invention, the direction of the rotary tool is not changed while the tool is inserted to the rim member 120. This prevents generation of excessive friction heat, and thereby realizes a good weld.

Abstract: Abutted portions of face plates 12b and 22b of frame members 10 and 20 are friction stir welded. With the abutting, a projecting portion 20c of an end portion of the face plate 20b of the frame member 20 is inserted into a recessed portion 12c of an end portion of the face plate 12b of the frame member 10. By this engagement, the outer face on one face side of the face plates 12b and 20b form a smooth surface, so that there is no step at the joined edges. Next, a rotary tool 250 is inserted into the gap between the abutted plates, from the side of the raised portions 16 and 26 of the face plates 12b and 20b, while the other faces 12bc and 20bc of the face plates 12b and 20b are supported flatly on a bed during the friction stir welding. Accordingly, the welding of the engaged plates can be carried out without any step-wise difference.

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.