JP2015027699A - Friction stir welded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a decrease in a plate thickness at a joining part of welded members after welding, and to prevent a decrease in strength at the joining part without interference between a rear part of a shoulder part of a tool and the welded member even in a case of a curved surface shape with a small radius and the thin welded member when the welded members with the curved surface shape in a tool advancing direction are mutually subjected to friction stir welding.SOLUTION: A friction stir welded body 1 is obtained by mutually butting two welded members 2, 3 with a curved surface shape in an advancing direction F of a rotating tool 4 and by subjecting the welded members to friction stir welding by inserting the rotating tool 4 in a planned joining part of the welded members 2, 3. A protruding part 5 having a slanting surface part 5a is provided on an end part of the welded member 3 on the side where the rotating tool 4 is inserted, and the friction stir welding is performed by inserting the rotating tool 4 substantially perpendicularly to the slanting surface part 5a.

Description

  The present invention relates to a friction stir welded body, and more specifically, when two members to be joined made of a metal material are abutted with each other, or two or more members to be joined are overlapped to form a two-dimensional plane. The present invention relates to a friction stir welded body joined by friction stir welding a portion having a curved surface shape other than the flat surface portion from the flat surface portion in the traveling direction of the rotating tool for joining the portions.

As a conventional method of joining two members to be joined made of a metal material, there is a method of performing friction stir welding (FSW) using a cylindrical rotary tool 51 as shown in FIG. The rotating tool 51 includes a large-diameter shoulder portion 52 and a small-diameter protruding probe portion 53 provided so as to protrude from the shoulder portion 52. The shoulder portion 52 and the probe portion 53 are rotated. It is arranged concentrically with respect to the axis C of the tool 51.
In the case of joining two members 54 to be joined, the rotary tool 51 is abutted against a portion to be joined between the members 54 to be joined, inserted while rotating around the axis C, and a predetermined joining line (not shown). ) Along the tool traveling direction F. At this time, if the probe member 53 agitates and plastically flows the member to be joined 54 softened by frictional heat generated between the rotary tool 51 and the member 54 to be joined, the joint portion is aligned along a predetermined joining line. Will be formed.

  In general, in the friction stir welding method, in order to prevent a cavity defect after joining, the axis C of the rotary tool 51 is joined to the member to be joined 54 by being inclined by the advance angle α. That is, at the time of stirring by the probe unit 53, at least the cross-sectional area of the rotary tool 51 is obtained in order to obtain a good bonded joint (bonded portion) without defects without flowing out the material of the bonded member 54 from the shoulder portion 52. Half is brought into contact with the member 54 to be joined.

By the way, in the friction stir welding method, joining the members to be joined having curved shapes in the traveling direction F of the rotary tool 51 has not been seen much, but a similar friction stir welding method has been proposed. (For example, refer to Patent Documents 1 to 3).
Patent Document 1 discloses a shape of a rotary tool that enables friction stir welding even when a member to be joined has a curved surface shape. Patent Document 2 discloses a T-type, L-type, which is joined by friction stir welding, and the contact surface of the shoulder portion is formed in an inclined plane across both the horizontal member to be joined and the member to be erected. A vertical or inclined standing joint structure such as a letter shape, an I shape, a saddle shape, and a saddle shape is disclosed. Further, Patent Document 3 discloses a friction stir bonded body having an inclined jumping up as a detection unit that can be confirmed by a sensor of a bonded portion that abuts a member to be bonded.

JP 2007-301579 A JP 2003-326375 A JP 2006-35284 A

  However, while maintaining a state in which at least half of the cross-sectional area of the shoulder portion 52 and the horizontal surface of the rotary tool 51 is in contact with the member to be joined, as shown in FIG. When the members to be joined 55 and 56 having the curved portion R are to be friction stir welded, the rear portion of the shoulder portion 52 of the rotary tool 51 excessively interferes with the members to be joined 55 and 56. Therefore, particularly when the radius of the curved surface shape is small, or when the plate thickness of the members to be joined 55 and 56 is thin, the plate thickness of the joint portion W after joining the members to be joined 55 and 56 in the curved portion R of the curved surface shape. There is a possibility that t is greatly reduced, and the strength of the joined portion W of the joined members 55 and 56 having the curved portion R is lowered.

  On the other hand, the shape of the rotary tool described in Patent Document 1 is very complicated, and the material of the rotary tool is very hard such as SK material, SKD material, PCBN (polycrystalline cubic boron), etc. However, there was a problem that considerable processing costs and production days were required. Further, Patent Document 2 does not describe the above-described problem of the present invention. Temporarily, in the case of friction stir welding between the members to be joined having curved shapes in the traveling direction of the tool in the disclosed configuration, since it is necessary to abut the inclined surfaces, compared to the case where the vertical surfaces are abutted, There are problems that it is difficult to align the butted portion and the positioning accuracy is low. Furthermore, as in Patent Document 2, the above-described problem of the present invention is not described in Patent Document 3. Temporarily, when the joined members having curved shapes in the advancing direction of the tool are friction stir welded with the disclosed configuration, the tool is inserted from the substantially vertical direction with respect to the joined members. When the radius is small or the plate thickness of the bonded member is thin, the plate thickness of the bonded portion after bonding of the bonded member in the curved curved portion is greatly reduced, and the strength of the bonded portion is reduced. There was a problem of being unavoidable. Therefore, there has been a demand for a high-quality friction stir bonded body obtained by friction stir welding of two members to be bonded having a curved shape with a generally used rotary tool having a shoulder portion and a probe portion. .

  The present invention has been made in view of such circumstances, and the purpose thereof is when the radius of the curved surface shape is small when the members to be bonded having curved surface shapes in the tool traveling direction are friction stir welded, or Even when the plate thickness of the member to be joined is thin, interference between the rear portion of the shoulder portion of the tool and the member to be joined does not occur, and a reduction in the plate thickness of the joint portion of the member to be joined after joining is suppressed. It is an object of the present invention to provide a friction stir bonded body that can prevent a decrease in strength.

  In order to solve the above-described problems of the prior art, the present invention is configured to abut the two members to be joined having curved shapes in the advancing direction of the tool, and to insert the tool into a joining portion between the members to be joined. A friction stir welded body to be friction stir welded, wherein at least an end of the member to be joined on the side where the tool is inserted is provided with a protrusion having a slope, On the other hand, the tool is inserted substantially vertically and is friction stir welded.

  Moreover, in this invention, the length of the side of the said slope part is set more than the diameter of the shoulder part of the said tool.

  Furthermore, in the present invention, the protrusion is formed in a substantially triangular shape in cross section.

  In the present invention, the angle θ between the hypotenuse and the base of the protrusion having a substantially triangular cross section is set in a range of 40 ° ≦ θ <75 °.

  Further, in the present invention, the end of the member to be joined on the side where the tool is not inserted has a substantially quadrangular cross section or a substantially triangular cross section in contact with the protrusion of the member to be joined on the side where the tool is inserted. Is formed.

  Further, in the present invention, the protrusion extends to the upper surface of the end of the bonded member on the side where the tool is not inserted, and can be overlapped with the upper surface of the end of the bonded member on the side where the tool is not inserted. It is configured.

  Further, the present invention provides a friction stir welding by superimposing two or more members to be joined having a curved surface shape in the advancing direction of the tool and inserting the tool into a part to be joined between the members to be joined. An end of the member to be joined on the side where the tool is inserted is formed in an inclined surface shape, and the tool is inserted substantially perpendicularly to the end of the inclined surface shape. And friction stir welding.

  The friction stir welded body according to the present invention abuts two members to be joined having a curved surface shape in the traveling direction of the tool, and inserts the tool into a portion to be joined between the members to be joined. A protrusion having a slope is provided at least on the end of the member to be joined on the side where the tool is inserted, and the tool is substantially perpendicular to the slope. Since it is inserted and friction stir welded, the protrusion can be a part where the rear part of the shoulder part of the tool and the member to be joined interfere with each other. Therefore, according to the friction stir welded body of the present invention, when the members to be welded having curved shapes in the tool advancing direction are friction stir welded, if the radius of the curved shape is small, or the plate thickness of the members to be joined is thin. Even in the case, interference between the rear portion of the shoulder portion of the tool and the member to be joined does not occur, and the reduction in the thickness of the joint portion of the member to be joined after joining can be suppressed, and the strength reduction of the joint portion can be surely prevented. be able to.

  Further, in the present invention, since the length of the side of the slope portion is set to be equal to or larger than the diameter of the shoulder portion of the tool, it is possible to suppress the occurrence of a joint defect due to the outflow of material in the joint portion of the member to be joined. And a good joint can be obtained.

  Furthermore, in the present invention, since the protrusion is formed in a substantially triangular cross section, an increase in weight due to the presence of the protrusion can be reduced.

  In the present invention, the angle θ between the oblique side and the bottom side of the protrusion having a substantially triangular cross section is set in a range of 40 ° ≦ θ <75 °. The interface can be reliably agitated, and a bonded portion having a higher strength can be obtained than the bonded members having the plate thickness without the protrusions.

  Further, in the present invention, the end of the member to be joined on the side where the tool is not inserted has a substantially quadrangular cross section or a substantially triangular cross section in contact with the protrusion of the member to be joined on the side where the tool is inserted. Since it is formed, it can be joined in a state in which the ends of the two members to be joined are reliably abutted, and it is possible to suppress the occurrence of joining defects due to the outflow of material at the joined portion, and to obtain a good joined portion. Can do.

  Further, in the present invention, the protrusion extends to the upper surface of the end of the bonded member on the side where the tool is not inserted, and can be overlapped with the upper surface of the end of the bonded member on the side where the tool is not inserted. Therefore, the end portions of the members to be joined can be positioned with high accuracy, and a good joined portion can be obtained.

  In addition, the friction stir bonded body according to the present invention includes two or more members to be joined that have a curved shape in the traveling direction of the tool, and friction is obtained by inserting the tool into a planned joining portion between the members to be joined. The end of the member to be joined on the side where the tool is inserted is formed in an inclined surface shape, and the tool is substantially perpendicular to the end of the inclined surface shape. Since the friction stir welding is carried out, the same effects as those of the above-described invention can be obtained even with the overlap welding.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a friction stir joined body according to a first embodiment of the present invention, wherein (a) is a perspective view of a state in which two members to be joined are butted together and a rotary tool is inserted into a part to be joined; It is sectional drawing. It is sectional drawing which shows the friction stir conjugate | zygote which concerns on the 1st modification of 1st Embodiment of this invention. It is sectional drawing which shows the friction stir conjugate | zygote which concerns on the 2nd modification of 1st Embodiment of this invention. It is sectional drawing which shows the friction stir conjugate | zygote which concerns on the 3rd modification of 1st Embodiment of this invention. It is sectional drawing which shows the friction stir conjugate | zygote which concerns on the 4th modification of 1st Embodiment of this invention. FIG. 2 shows a friction stir joined body according to a second embodiment of the present invention, wherein (a) is a perspective view of a state in which two members to be joined are butted together and a rotary tool is inserted into a part to be joined; It is sectional drawing. It is sectional drawing which shows the friction stir conjugate | zygote which concerns on the modification of 2nd Embodiment of this invention. FIG. 3 shows a friction stir joined body according to a third embodiment of the present invention, in which (a) is a perspective view of a state in which two members to be joined are overlapped and a rotary tool is inserted into a planned joining portion; FIG. Moreover, (c) is a cross-sectional view of a state in which three members to be joined are overlapped and a rotary tool is inserted into a part to be joined. It is sectional drawing which shows the state which inserted the rotation tool in the joining plan part of the conventional to-be-joined member. A conventional friction stir joined body is shown, (a) is a perspective view of a state in which two members to be joined are brought into contact with each other and a rotary tool is inserted into a planned joining portion, and (b) is a sectional view thereof.

[First Embodiment]
Hereinafter, a friction stir assembly according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a friction stir joined body according to a first embodiment of the present invention, and (a) is a perspective view of a state in which two members to be joined are butted together and a rotary tool is inserted into a planned joining portion. b) is a sectional view thereof.

As shown in FIG. 1, the friction stir joined body 1 according to the first embodiment joins two-dimensional flat portions when the two members to be joined 2 and 3 made of a metal material are brought into contact with each other and friction stir joined. In the traveling direction F of the rotary tool 4, the structure is joined by friction stir welding of a portion having a curved surface shape other than the planar portion from the planar portion. That is, the friction stir joined body 1 abuts the two members 2 and 3 having curved surfaces in the traveling direction F of the rotary tool 4 used as the friction stir welding tool, and also connects the rotary tool 4 to the member 2 to be joined. , 3 is a joined body obtained by inserting into a joint portion to be joined and friction stir welding.
For this reason, the members 2 and 3 of this embodiment are formed in a substantially L shape in a side view, and are perpendicular to the planar portions 2a and 3a extending in the horizontal direction and the rear ends of the planar portions 2a and 3a. It has vertical surface portions 2b and 3b extending in the direction, and curved surface-shaped curved portions 2c and 3c connecting the flat surface portions 2a and 3a and the vertical surface portions 2b and 3b.

In addition, of the members 2 and 3 to be joined of the present embodiment, the end portion of the member 3 to be joined on the side where the rotary tool 4 is inserted is provided with a protruding portion 5 having a non-vertical slope portion 5a. This protrusion 5 is located above the upper surface of the end of the member 3 to be joined so that the shoulder (described later) of the rotary tool 4 during friction stirring does not come into contact with the curved parts 2c and 3c of the members 2 and 3 to be joined. It is formed in a quadrangular shape projecting over a certain height, and is configured as a portion where a rear portion of a shoulder portion (described later) of the rotary tool 4 interferes with the member 3 to be joined. Therefore, in the friction stir joined body 1 of the present embodiment, the interference portion between the rear portion of the shoulder portion (described later) of the rotary tool 4 and the member to be joined 3 moves to the protruding portion 5 instead of the member to be joined 3. It has become.
The slope portion 5a is a place where a shoulder portion (to be described later) of the rotary tool 4 is placed, and an upper end corner portion on the opposite side to the joined member 2 into which the rotary tool 4 is not inserted is obliquely cut at a predetermined angle. The rotary tool 4 is configured to be inserted substantially perpendicular to the inclined surface portion 5a and frictionally stirred.

  The rotary tool 4 of the friction stir welding tool includes a cylindrical shoulder portion 6 that contacts the inclined surface portion 5a of the projection portion 5 of the member 3 to be joined, and a cylindrical probe portion that is provided so as to protrude from the shoulder portion 6. 7 and is configured to rotate about the axis C. The probe portion 7 is formed to have a smaller diameter than the shoulder portion 6, and is set so that the tip portion 7 a extends beyond the interface between the members 2 and 3 (the planned joining portion) during friction stir welding. It is arranged concentrically with the axis C of the shoulder portion 6.

Next, a procedure for obtaining the friction stir joined body 1 of the first embodiment by joining the pair of members 2 and 3 to be joined using the rotating tool 4 will be described.
As shown in FIG. 1, first, the end portions of the two members to be joined 2 and 3 are brought into contact with each other and positioned. Next, the shoulder portion 6 is pressed against the inclined surface portion 5 a while rotating the rotary tool 4 from the projection portion 5 of one of the members to be joined 3. At this time, the rotary tool 4 is inserted substantially perpendicular to the inclined surface portion 5a. In this state, when the rotary tool 4 is moved along a predetermined joining planned portion (not shown), the softened members 2 and 3 around the probe portion 7 are agitated and plastically flowed, and the joining portion W is formed. Will be formed.

  In the friction stir bonded body 1 according to the first embodiment of the present invention, the protruding portion 5 having the slope portion 5a is provided at the end of the member 3 to be joined on the side where the rotary tool 4 is inserted, and the slope portion 5a Since the rotary tool 4 is inserted substantially vertically and is friction stir welded, the protrusion 5 becomes an interference part between the rear portion of the shoulder portion 6 of the rotary tool 4 and the member 3 to be joined, and at the time of friction stirring, the rotary tool It is possible to prevent the rear part of the shoulder portion 6 of 4 from coming into contact with the member 3 to be joined. Therefore, the friction stir joined body 1 of the present embodiment has the curved portions 2c, 2c, and 2b when the members to be joined 2 and 3 having the curved portions 2c, 3c in the traveling direction F of the rotary tool 4 are friction stir joined. Even when the radius of 3c is small or the plate thickness of the member to be joined 3 is thin, the rear portion of the shoulder portion 6 of the rotary tool 4 and the member to be joined 3 do not interfere with each other. It is possible to suppress a decrease in the plate thickness of the bonded portion W of the members 2 and 3 to be bonded, to reliably prevent a decrease in the strength of the bonded portion W, and to provide a structure having excellent quality strength.

2 to 5 show a friction stir joined body according to first to fourth modified examples of the first embodiment of the present invention. In addition, about the part similar to what was demonstrated in 1st Embodiment mentioned above, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.
(1) In the friction stir welded body 11a of the first modified example, as shown in FIG. 2, unlike the first embodiment, the length L of the side surface of the inclined surface 5a of the protrusion 5 is the shoulder of the rotary tool 4. It is set to be equal to or larger than the diameter D of the portion 6 (see FIG. 1B). As a result, it is possible to suppress the occurrence of a bonding defect due to the outflow of the material at the bonded portion W of the members 2 and 3 to be bonded, and the friction stir bonded body 11a having the high-strength bonded portion W can be obtained.
(2) In the friction stir assembly 11b of the second modification, as shown in FIG. 3, unlike the first embodiment, the protrusion 5 is formed in a substantially triangular cross section, and the protrusion height is the other object. It is set so as to substantially match the plate thickness of the joining member 2. Thereby, even if the projection part 5 which contributes to the strength improvement of the junction part W is provided, the weight increase of the friction stir joined body 11b can be reduced.

(3) In the friction stir bonded body 11c of the third modified example, as shown in FIG. 4, unlike the first embodiment, the protruding portion 5 is formed in a substantially triangular cross section, and the protruding portion has a substantially triangular cross section. 5 is set in a range of 40 ° ≦ θ <75 °, and the protruding height is set to be larger than the thickness of the other member 2 to be joined. ing. According to this, it becomes possible to stir firmly the joining interface between the to-be-joined members 2 and 3 with the rotary tool 4, and compared with the case where the to-be-joined members in the plate | board thickness of the state which does not have the projection part 5 are joined. In addition, the friction stir bonded body 11c having the high-strength bonded portion W can be obtained. In addition, when the angle θ is set in a range of 40 ° ≦ θ <75 °, it is possible to join all the joined members 2 and 3 that are abutted, but when the angle θ is 40 ° or less, The stirring area of the rotary tool 4 does not reach the joining interface of the members 2 and 3 to be joined. On the other hand, when the angle θ is 75 ° or more, there is a possibility that a crack is generated from the middle of the slope portion 5a of the protruding portion 5 and breaks after joining.
(4) In the friction stir bonded body 11d of the fourth modified example, as shown in FIG. 5, unlike the first embodiment, the end of the member 2 to be bonded on the side where the protrusion 5 does not insert the rotary tool 4 It extends to the upper surface, and the bottom surface of the extension portion 5b having a triangular cross section is configured to be able to overlap the upper surface of the end portion of the member 2 to be joined on the side where the rotary tool 4 is not inserted. Thereby, it becomes possible to perform positioning of the edge parts of the to-be-joined members 2 and 3 with high precision, and the friction stir joined body 11d provided with the high intensity | strength junction part W can be obtained.

[Second Embodiment]
FIG. 6 shows a friction stir joined body according to a second embodiment of the present invention, wherein (a) is a perspective view of a state in which two members to be joined are butted together and a rotary tool is inserted into a planned joining portion. b) is a sectional view thereof. In addition, about the part similar to what was demonstrated in 1st Embodiment mentioned above, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.
In the friction stir joined body 21 according to the second embodiment, as shown in FIG. 6, the projection 5 of the member 3 to be joined on the side where the rotary tool 4 is inserted is formed in a substantially triangular cross section, and has a substantially triangular cross section. The angle θ between the hypotenuse and the base of the protrusion 5 is set in a range of 40 ° ≦ θ <75 °. On the other hand, the end of the bonded member 2 on the side where the rotary tool 4 is not inserted faces the projection 5 of the bonded member 3 on the side where the rotary tool 4 is inserted, and the cross section has a size that abuts against the projection 5. It is formed in a substantially triangular shape and is configured as an opposing protrusion 8.

  As described above, in the friction stir bonded body 21 of the second embodiment, the end of the member 2 to be bonded on the side where the rotary tool 4 is not inserted is formed in a substantially triangular cross section in contact with the protrusion 5 of the member 3 to be bonded. Since it is configured as the opposing projection 8, the area of the contact portion where the ends of the two members 2 and 3 are abutted increases, and the ends of the two members 2 and 3 are securely connected. Bonding can be performed in a state of being abutted, generation of a bonding defect due to outflow of material at the bonding portion W can be effectively suppressed, and a high-strength bonding portion W can be provided.

By joining the members to be joined 2 and 3 under the friction stir welding (FSW) conditions shown in Table 1 below, the friction stir joined body 21 according to the second embodiment of the present invention was obtained.
Here, as the members 2 and 3 to be joined, those having a plate thickness of 3 mm were used. Further, as the rotating tool 4, a tool having a shoulder portion 6 having a diameter D1 of 12 mm and a probe portion 7 having a diameter D2 of 3.6 mm and a length L1 of 4.5 mm was used.

In addition, the friction stir welding test was performed by changing the angle θ of the inclined surface portion 5a of the protrusion 5, and the tensile test of the joint W of the friction stir bonded body 21 was performed. The results are shown in Table 2 below.
Here, Autograph AG-X plus 100 kN (manufacturer: Shimadzu Corporation) was used as the tensile tester, and the test piece was manufactured by cutting out the curved portion of the joint W of the friction stir joint 21 into a strip shape. The test piece was fixed using a gripping tooth that matched the curved shape of the curved part, and pulled in a direction perpendicular to the joining progress direction at a pulling speed of 5 mm / min.

表２から、θ＝３５°のときは、被接合部材２，３の接合界面に回転ツール４の撹拌領域が達しなかったため、被接合部材２，３を接合できなったことが判る。また、θが４０°≦θ≦８０°の範囲のときは、すべての被接合部材２，３を接合できたことが判る。さらに、θが７５°以上のときは、摩擦撹拌接合体２１の突起部５の斜面部５ａの途中から亀裂が生じて、破断した。

From Table 2, it can be seen that when θ = 35 °, the stirring region of the rotary tool 4 did not reach the bonding interface of the members 2 and 3 to be bonded, so that the members 2 and 3 could not be bonded. When θ is in the range of 40 ° ≦ θ ≦ 80 °, it can be seen that all the members 2 and 3 were bonded. Furthermore, when θ was 75 ° or more, a crack occurred from the middle of the slope portion 5a of the projection portion 5 of the friction stir bonded body 21, and the fracture occurred.

FIG. 7 shows a friction stir assembly according to a modification of the second embodiment of the present invention. In addition, about the part similar to what was demonstrated in 1st and 2nd embodiment mentioned above, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.
In the friction stir bonded body 21a of this modified example, as shown in FIG. 7, unlike the second embodiment, the end of the member 2 to be joined on the side where the rotating tool 4 is not inserted inserts the rotating tool 4. It is formed in a substantially quadrangular cross section having a size that faces the protrusion 5 of the member to be bonded 3 on the side and abuts against the protrusion 5 and is configured as an opposing protrusion 8a. As a result, it is possible to suppress the occurrence of bonding defects due to the outflow of material at the bonded portions W of the members 2 and 3 to be bonded, and the friction stir bonded body 21a having the high-strength bonded portions W can be obtained.

[Third Embodiment]
FIG. 8 shows a friction stir joined body according to a third embodiment of the present invention, in which (a) is a perspective view of a state in which two members to be joined are overlapped and a rotary tool is inserted into a planned joining portion. (B) is a sectional view thereof. Moreover, (c) is a cross-sectional view of a state in which three members to be joined are overlapped and a rotary tool is inserted into a part to be joined. In addition, about the part similar to what was demonstrated in 1st and 2nd embodiment mentioned above, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.
In the friction stir bonded body 31 of the third embodiment, as shown in FIG. 8, the member to be bonded 2 on the side where the rotary tool 4 is inserted is placed on the upper surface of the member 3 on the side where the rotary tool 4 is not inserted. In this structure, the rotary tool 4 is inserted into a portion to be joined between the members to be joined 2 and 3 or the members to be joined 2, 3, and 9 and joined by friction stir welding. In the friction stir bonded body 31 of the present embodiment, the end 2d of the member 2 to be bonded on the side where the rotary tool 4 is inserted is formed in an inclined surface shape having a substantially triangular cross section. The inclined surface-shaped end portion 2d is a portion on which the shoulder portion 6 of the rotary tool 4 is placed, and is formed by being obliquely cut at a predetermined angle. It is configured so as to be frictionally stirred by being inserted substantially perpendicular to the end 2d.

  Thus, in the friction stir joined body 31 of the third embodiment, the end 2d of the member 2 to be joined on the side where the rotary tool 4 is inserted is formed in an inclined surface shape having a substantially triangular cross section. Even if it is joining, the edge part of two to-be-joined members 2, 3 or three to-be-joined members 2, 3, and 9 can be joined reliably, and the effect similar to butt joining can be acquired.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Friction stir joined body 2,3,9 Joined member 2a, 3a Plane part 2b, 3b Vertical surface part 2c, 3c Curved part 2d End part 4 Rotating tool 5 Protrusion part 5a Slope part 6 Shoulder part 7 Probe part 7a Probe part Tip 11a, 11b, 11c, 11d Friction stir welded body 21, 31 Friction stir welded body C Center axis of rotary tool F Traveling direction of rotary tool W Joint

Claims (7)

While abutting two to-be-joined members having a curved shape in the advancing direction of the tool, and a friction stir joined body to be friction stir welded by inserting the tool into the joining planned portion of the to-be-joined members,
At least an end of the member to be joined on the side where the tool is inserted is provided with a protrusion having a slope portion,
The friction stir joint, wherein the tool is inserted substantially perpendicularly to the slope portion and is friction stir welded.   2. The friction stir bonded assembly according to claim 1, wherein a length of a side of the slope portion is set to be equal to or larger than a diameter of a shoulder portion of the tool.   The friction stir joined body according to claim 1, wherein the protrusion has a substantially triangular cross section.   4. The friction stir bonded assembly according to claim 3, wherein an angle θ between the oblique side and the bottom side of the projecting portion having a substantially triangular cross section is set in a range of 40 ° ≦ θ <75 °.   The end portion of the member to be joined on the side where the tool is not inserted is formed in a substantially quadrangular cross section or a substantially triangular shape in cross section that abuts on the protrusion of the member to be joined on the side where the tool is inserted. The friction stir joined body according to any one of claims 1 to 4.   The protrusion is configured to extend to the upper surface of the end portion of the member to be bonded on the side where the tool is not inserted and to be superimposed on the upper surface of the end portion of the member to be bonded on the side where the tool is not inserted. The friction stir joined body according to any one of claims 1 to 4. A friction stir joined body that is joined by friction stir welding by superimposing two or more members to be joined having a curved shape in the direction of travel of the tool and inserting the tool into a planned joining portion of the members to be joined. ,
The end of the member to be joined on the side where the tool is inserted is formed in an inclined surface shape,
The friction stir joint, wherein the tool is inserted substantially perpendicularly to the end portion having the inclined surface shape and is friction stir joined.

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