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: 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 face plate 11 is butted against a frame 520, from which a segment 525 for overlapping with the rear surface of a face plate 21 is projected. The frame 520 includes a raised portion 523. A friction stir welding is performed by inserting a rotary tool 50 into the raised portion 523. The rotary tool 50 is rotated clockwise as seen from the large-diameter portion 51, so that the pressure of fluidized metal is higher at the right-hand side of the axial center of the rotary tool 50. There exists the overlapping surface of the face plate 21 and the projecting segment 525 at the side with high pressure of metal. The raised portion 523 exists at the left-hand side of the axial center of the rotary tool 50. Thus, the occurrence of continuous metal oxide or a notch at the overlapping surface can be restrained.

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: 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 abutted face plates of frame members are joined using friction stir welding. Next, a connection member is mounted on seats formed in the frame members, while a projection of one end of the connection member is inserted into a groove of an end portion of a face plate of the frame member. Next, the other end of the connection member is temporarily welded to the face plate of the hollow frame member. With this condition, an abutted portion of the face plate and the connection member are joined using friction stir welding. Then, the overlapped portion between the other end of the connection member and the frame member is joined by friction stir welding. When the hollow frame members are welded from one side, a temporary welding of the connection member can be reduced.

Abstract: End portions of members 10, 20 are abutted against each other. A trapezoidal convex portion 22 of the member 20 is inserted into a trapezoidal concave portion 12 of the member 10. A friction stir welding is performed by inserting a rotary tool 50 from the side of raised portions 13, 23. A small-diameter portion 51b of the rotary tool 50 is tapered and is provided with a screw thread 51b. A large-diameter portion 53 is of a member different from an axis portion of the rotary tool 50 and is connected thereto by a pin 59. The screw thread of the screw thread portion 51b could be formed in the vicinity of a concave surface 53g of an end surface of the large-diameter portion 53, so that stirring near the end surface can be performed sufficiently. Therefore, good friction stir welding can be achieved.

Abstract: A plate 20 is stacked on a plate 10, the stacked surface of the plate 10 being provided with a groove 12. The outer portion of the plate 20 is equipped with a raised portion 22. A rotary tool 50 is inserted into the raised portion 22 for performing a friction stir welding. The groove 12 is filled up during the friction stir welding with the metal material constituting said raised portion 22. According to the present method, the pressure of the welding portion will not be excessive, and therefore the generation of a notch in the stacked surface is prevented. This provides a friction stir welding method which produces a lightweight joint having good characteristics.

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 preformed 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: Face plates 11b and 12b of a hollow shape member 10 are abutted against face plates 21b and 22b of a hollow shape member 20. Projections 15, 16, 25 and 26 are formed to both sides of the face plates at the abutted areas. The rotary tool 50 comprises two large-diameter portions 53 and 54, and a small-diameter portion 51 disposed therebetween. The projections 15, 16, 25 and 26 of the portions 11b and 21b (12b and 22b) to be welded are sandwiched between the two large-diameter portions 53 and 54 upon performing the friction stir welding. According thereto, even if the heights of the abutted areas of the plates against the two large-diameter portions 53 and 54 differ, the face plates 11b and 21b (12b and 22b) will not be damaged (cut) by the tool since only the depth of the large-diameter portion being inserted to the projections varies. Therefore, the welding process will not reduce the thickness of the face plates, leading to design-related and function-related problems.

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: 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: 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: 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: 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: 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: 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: 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: End portions of members 10, 20are abutted against each other. A trapezoidal convex portion 22of the member 20is inserted into a trapezoidal concave portion 12of the member 10. A friction stir welding is performed by inserting a rotary tool 50from the side of raised portions 13, 23. A small-diameter portion 51bof the rotary tool 50is tapered and is provided with a screw thread 51b. A large-diameter portion 53is of a member different from an axis portion of the rotary tool 50and is connected thereto by a pin 59. The screw thread of the screw thread portion 51bcould be formed in the vicinity of a concave surface 53gof an end surface of the large-diameter portion 53, so that stirring near the end surface can be performed sufficiently. Therefore, good friction stir welding can be achieved.

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.