JP2001081903A - Friction stirring joint extrusion section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction stirring joint extrusion section capable of obtaining a joint section with high strength in friction stirring joint of an overlap section. SOLUTION: The end of a member 310 and the end of a member 320 overlap each other, and friction stirring joint is made in a state to insert a rotational tool into the members 310 and 320 in a state to incline it to overlapped surfaces 310b and 320b. Since the rotational tool is inclined to the overlapped surfaces 310b and 320b, stirring and mixing are substantially made in the direction of the axis of the rotational tool, and sufficient stirring is made to make it possible to firmly connect them to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to friction stir welding of lap joints made of aluminum alloy or the like.

[0002]

2. Description of the Related Art In a friction stir welding method, a round bar (referred to as a rotary tool) inserted in a joint is moved along a joining line while rotating, so that the joint is heated, softened, plastically fluidized, and solid-phased. It is a joining method. The rotary tool has a small diameter portion inserted into the joint and a large diameter portion located outside. The small diameter part and the large diameter part are coaxial. The boundary between the small diameter portion and the large diameter portion is slightly inserted into the joint.

[0003] This is the Presented at IBEC 98, Detroit,
MI, USA, 29 Sept-10ct 1998, No 98IBECC-37 "Appl
ication of Friction Stir Welding to Lightweight Ve
hicles "(hereinafter referred to as Document 1), and
No. 309164 (EP0797043A2) (hereinafter referred to as Document 2). FIG. 4 of Document 1 shows lap joining. FIG. 9 of the latter document shows that the joining of two surfaces of a hollow extruded profile is performed from one surface. Also shown is a joint for preventing deformation of the hollow profile.

[0004]

Friction stir welding is a process in which members to be joined are brought close to each other, and the two are sufficiently stirred and mixed to be joined. Insufficient agitation causes a decrease in quality such as a decrease in strength due to generation of defects and a decrease in appearance. For this reason, in order to ensure the quality of the joint, it is important to sufficiently stir and mix the members to be joined. Since the friction stir welding is performed by rotating the rotary tool, the flow of the member to be welded due to the friction between the rotary tool and the member to be welded is mainly in only the rotation direction. Almost no agitation in the direction of the rotation axis.

[0005] This is because Script Materially.
No.9, pp.1041-1046, 1999 "SOLID-STATE FLOW VISUAL
IZATION IN THE FRICTION-STIR WELDING OF 2024 AL TO
6061 AL "(hereinafter referred to as Reference 3) as shown in FIG. 2. According to this, the member to be joined is sufficiently stirred in the rotating direction of the rotating tool, but the inserting direction of the rotating tool is That is, the axial direction of the rotating tool (the thickness direction of the member to be joined,
It can be clearly seen that little stirring was performed in the (overlapping direction).

When the butted portions are joined by the friction stir welding method, the members to be joined are sufficiently stirred, and a joint of required quality can be obtained. This is because the contact surface of the member to be joined is parallel to the rotation axis of the rotary tool, that is, the contact surface is oblique in a direction perpendicular to the rotation direction of the rotary tool, and the rotation of the rotary tool agitates and mixes the contact surface. It is known that the mechanical properties in this case are better than those of conventional arc welding. This is, for example, Science and
Technology of Welding and Joinning 1997 Vol.2 No.5
pp.199-208 "Mechanical properties of welded joint
s in thin walled aluminum extrusions "(hereinafter referred to as Reference 4).

[0007] However, when joining in which the joining surface and the rotational direction of the rotary tool are parallel to each other, such as lap joining, by the friction stir joining method, it is difficult to obtain mechanical characteristics such as butt portions. The flow of the member to be joined due to the friction between the rotary tool and the member to be joined is mainly in the rotation direction only. Almost no agitation in the direction of the rotation axis. Therefore, when the joining surface and the rotating direction of the rotary tool are parallel as in the case of lap joining, the mechanical characteristics are not large.

This is shown in FIG.
A black line along the horizontal direction is recognized in the upper and lower central portions of the joint in FIG. This is an oxide film existing on the surface of the member to be joined before joining. The oxide film existing on the surface of the member to be joined remains almost unchanged from the state before joining even after joining, and is present on the overlapping surface. This indicates that sufficient stirring is not performed on the overlapping surface parallel to the rotation direction.
Therefore, when a tensile test is performed, the two members to be joined are separated from each other along the overlapping surface. That is, the strength is small. For this reason, it is difficult to employ lap joining as a strength member.

An object of the present invention is to provide a high-strength joint in friction stir welding of an overlapped portion.

[0010]

The object of the present invention is to overlap one end of a first member with the other end of a second member, and the overlapped portion is the other end of the first member. Between the first member and the second member in a state in which the rotary tool is inclined with respect to the overlapped surface between the first member and the second end of the second member.
It can be achieved by performing friction stir welding in a state of being inserted into the member.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS.
This will be described below. This embodiment is used as a strength member in which a tensile load acts on a joint. Two members 310,
320 has overlapping ends. One end of the member 310 and the other end of the member 320 are overlapped, and the overlapped portion is the member 3
10 and the other end of the member 320. The overlapping surfaces 310b and 320b are inclined. The inclination angle of the overlapping surfaces 310b, 320b is, for example, 4 degrees to 10 degrees. The other upper and lower surfaces 310c, 310d (320c,
320d) is parallel and horizontal. Lower surface 3 of member 320
20d is mounted on a gantry. The members 310, 320 are extruded profiles.

In this state, the friction stir welding is performed by moving the rotary tool 250 of the friction stir welding apparatus along the welding line with the rotary tool 250 being inserted into the overlapping portion from above. Rotary tool 25
The axis of 0 is the vertical direction (direction along the normal line of the joint). However, the axis is inclined in a known manner with respect to the traveling direction of the rotary tool 250. The joining line is perpendicular to the plane of FIG. The overlapping surfaces 310b and 320b are perpendicular to the joining line (joining direction). Stack surface 31
Ob, 320b can be said to be between the ends of the two members 310,320. The movement of the rotary tool 250 is performed by the member 310,
What is necessary is just to move relatively to 320.

The rotary tool 250 has a large diameter portion 252 and a small diameter portion 251 at the tip thereof. The small diameter portion 251 is a screw. The small diameter portion 251 is inserted deeper than the overlapping surfaces 310b and 320b. The tip of the small diameter portion 251 is the lower member 32
0 is inserted deeply near the lower surface 320d. Large diameter part 2
The lower end of 52 is slightly inserted from the upper surface 310 c of the member 310.

FIG. 2 shows a state after joining, and hatching indicates a joining bead (heat affected zone). The size of the joining bead is slightly larger than the outer shape of the inserted rotary tool 250. According to this, the rotation axis of the rotary tool 250 is vertical, but the overlapping surfaces 310b and 320b are inclined with respect to the horizontal plane. Therefore, it can be said that the overlapping surfaces 310b and 320b are inclined with respect to the axis of the rotary tool 250. Therefore, the overlapping surfaces 310b and 320b are inclined with respect to the rotation direction of the rotary tool 250. Therefore, the member 3
10 and 320 are stirred and mixed according to the inclination angle of the overlapping surfaces 310b and 320b. That is, it is mixed also in the axial direction of the rotary tool 250. Therefore, even if there is an oxide film before joining, it is mixed well. For this reason, even if the members 310 and 320 are pulled right and left, high-strength bonding can be obtained. Therefore, the members 310, 3
20 can be used as a strength member for pulling left and right.

The embodiment shown in FIGS. 3 and 4 will be described. The members 330 and 340 have overlapping ends. Members 330, 34
0 is a flat plate except for the projection 330e. The overlapping surface is horizontal. The rotary tool 250 is inclined at 4 to 10 degrees with respect to the vertical. The inclination direction is the end direction of the members 330 and 340. With this, the same effect as in the above embodiment can be obtained. The member 330 on the upper side, that is, the rotary tool 250 side
Is provided with a convex portion 330e protruding toward the rotary tool 250.

The protrusion 330e has a thickness t1 and a thickness t2 at the end of the plate portion of the member 330 from the extension of the upper surface of the plate portion. The end of the plate portion and the end of the t1 portion of the protrusion 330e are substantially perpendicular to the plate portion. The end of the plate portion and the end of the t1 portion of the protrusion 330e are substantially flush with each other. The upper surface of the projection 330e is inclined. That is, the upper surface of the protrusion 330e is orthogonal to the axis of the rotary tool 250. According to this, unnecessary portions in the member 330 can be reduced. In FIG. 4, the joining beads with hatching are inclined.

An embodiment in which the present invention is applied to a vehicle body of a railway vehicle will be described with reference to FIGS. In the following description, part numbers not shown in FIG. 5 may be used.
In that case, the part number obtained by subtracting 10 from the part number corresponds to the part with the right half part number. 5 is an enlarged view of a main part of FIG. 6, FIG. 6 is an enlarged view of a main part of FIG. 7, and FIG. 7 is a longitudinal sectional view of a main part of the side structure of FIG.

The vehicle body 200 has a side structure 20 forming a side surface.
1, a roof structure 202 constituting a roof, an underframe 203 constituting a floor, and a wife structure 204 constituting an end in a longitudinal direction. The side structure 201, the roof structure 202, and the underframe 203 are each formed by joining a plurality of extruded members. The longitudinal direction of the extruded profile is set to the longitudinal direction of the vehicle body. The extruded profile is a hollow profile made of an aluminum alloy. The configuration and joining method of the hollow members 10 and 20 constituting the side structure 201 will be described. The same applies to other parts and other structures.

The hollow profiles 10 and 20 are composed of two face plates 11 and 1
A plurality of ribs 13 arranged in a truss shape with 2, 21, 22;
23. The two face plates 11, 12 (21, 22) are substantially parallel. The pitch of the truss by the ribs 13 and 23 is the same. Truss: ribs 13, 23, face plate 1
1, 12, 21, and 22 are constituted by the center line of the plate thickness. The vertices are on the face plates 11, 12, 21, 22 side. Rails 19 and 29 for mounting equipment are integrally provided near the top of the truss inside the vehicle. The rails 19 and 29 are composed of two L-shaped members. The rails serve as seats for equipment such as interior boards and chairs.

The ends of the face plates 12 and 22 located on the outer surface side of the vehicle body project toward the adjacent hollow members 20 and 10 than the ends of the face plates 11 and 21 inside the vehicle. The protruding face plates are called 12b and 22b. The ends of the face plates 12b and 22b are abutted against each other to perform friction stir welding. The butting portions are butted so that the gap is small. Face plate 12
The plate thickness of b and 22b is larger than the plate thickness of the face plates 12 and 22 in the other portions. The hollow profiles 10, 20 rest on the bed 40 with the face plates 12, 22 facing downward. The side of the face plates 11 and 21 faces upward. The rotary tool 250 is inserted into the joint from above to perform friction stir welding. It can be said that friction stir welding is performed from the inside of the car. At the ends of the face plates 12b and 22b, there are convex portions 16 and 26 protruding toward the vehicle inside (that is, the face plates 11 and 21 side). The width and height of the projections 16 and 26 are substantially the same.

An end of the face plate 11 on the inside of the vehicle and an end of the face plate 21 are joined via a connecting member 30. Connection material 3
The zero end rests (overlaps) on a seat 27 (17) provided at the top of the truss. The seat 27 (17) is an overlapping surface. It is inclined as in FIG. Seat 27 (17)
It is at the intersection of the rib 23A (13A) and the rib 23B (13B). The intersection is located at the center of the width of the seat 27 (17).
That is, the vertex of the end truss is located at the center of the width of the seat 27 (17). The width of the seat 27 (17) is
Same as the width of 5. The seat 27 (17) is attached to the face plate 21 (1).
It is more concave than the outer surface of 1). The seat 27 (17) is open to the outside in the thickness direction of the hollow profile and to the end in the width direction.
The end 27b (17b) of the face plate 21 (11) is
It is inclined as a groove for arc welding.

The connecting members 30 are arranged for the purpose of making the surfaces of the face plates 11 and 21 continuous. For this reason, the seat 27 (17) is recessed by the thickness of the face plate 21 (11) with respect to the outer surface of the face plate 21 (11).
The center of the connecting member 30 excluding the both ends 35 is a plate 31 whose thickness is substantially the same as the thickness of the face plate 21 (11).

At both ends of the connecting member 30, there are convex portions 35 projecting upward. There is a V-shaped groove 36 on the upper surface of the projection. The groove 36 is located at the center of the width of the projection 35. The width of the convex portion 35 is larger than the diameter of the large diameter portion 252 of the rotary tool 250. The groove 36 is an object for position detection for guiding the rotary tool 250. The groove 36 is detected by the laser sensor so that the axis of the rotary tool 250 coincides with the groove 36. On the extension of the groove 36, that is, on the axis of the rotary tool 250, the two ribs 1
There is an intersection of 3A (23A) and 13B (23B).

The lower surfaces at both ends of the connecting member 30 are seats 27 (17).
Slope. Connecting material 30 and seats 17, 27
Are superimposed on a flat surface without any undulation, and they are in contact with each other.
The width of the connecting member 30 is the face plate 1 of the two hollow members 10 and 20.
It is smaller than the interval of 1, 21. The connection member 30 is the hollow member 1
It is an extruded profile of the same material as 0 and 20. Connection material 30
Is the same as the length of the hollow profiles 10, 20.

The distance P from the end of the face plate 11 to the end of the face plate 21 (the distance from the top of the truss at the end of the hollow section 10 to the top of the truss at the end of the hollow section 20) is another position. Truss pitch P.

The truss of the hollow profile is composed of face plates 11, 12, 2
When the vertices are on the 1, 22 side, it is an isosceles triangle. However, the trusses at the ends of the hollow members 10, 20 are not isosceles triangles. The angle formed by the ribs 13A and 23A constituting the truss at the ends of the hollow members 10 and 20 with respect to the vertical line is θ.
It is one. Ribs 13A, 2 constituting the end truss
The angle formed by 3B with respect to the vertical line is θ2. θ1 <θ
2.

For this reason, the rib 13A (23A) is
2 (22). Rib 13A and face plate 1
2 and the connection between the rib 23A and the face plate 22 have a space for inserting the friction stir welding apparatus. Since the ribs 13A and 23A stand up (θ1 is smaller) than the ribs 13B and 23A, the thickness of the ribs 13A and 23A is larger than the thickness of the ribs 13B and 23A. Rib 13B,
The plate thickness of 23B is larger than the plate thickness of the other ribs 13. The connection between the ribs 13A, 13B, 13 and the face plates 11, 12, 21, 22 is arc-shaped. Further, the thickness of the connection portion is determined from the viewpoint of strength.

A method for manufacturing this structure will be described. The hollow members 10 and 20 are placed on a bed 240 and fixed. The butted portions at the ends of the face plates 12b and 22b are in contact with or close to each other. The projections 16 and 26 of the butted portions of the face plates 12 and 22 are temporarily fixed by arc welding from above. Temporary welding is intermittent. Face plates 12b, 22b
The upper surface of the bed 240 on which the butting portion is placed is flat. Near the butted portion of the face plates 12b and 22b, the rib 13
A, 23A, near the intersection of the face plates 12b, 22b, rib 1
The three persons near the intersection of 3B, 23B and face plates 12, 22 are on bed 240 at the same height.

In this state, friction stir welding is performed by moving the rotary tool 250 of the friction stir welding apparatus along the welding line while inserting the rotary tool 250 from above into the butted portion of the projections 16 and 26. The axis of the rotary tool 250 is in the vertical direction (the direction along the normal line of the joint). However, the axis is inclined in a known manner with respect to the traveling direction of the rotary tool 250.
The butting portion of the two convex portions 16 and 26 is detected by the sensor to determine the position of the gap between the butting portions, and the axis of the rotary tool 250 is positioned in this gap.

The tip of the small diameter portion 251 of the rotary tool 250 is located near the lower surfaces of the face plates 12b and 22b. The lower end of the large diameter portion 252 is connected to the tops of the convex portions 16 and 26 and the face plates 12b and 22.
b is located between the inner side surface (the surface on the side of the face plates 11 and 21). The diameter of the large diameter portion 252 is smaller than the width formed by the two convex portions 16 and 26.

By the friction stir welding, the face plate 12b,
The gap between the butting portions 22b is filled and joined. The outer surface side (outside of the vehicle) of the butted portion is flatly joined. There is no concave portion of the joining line on the outer surface side of the face plates 12b and 22b. The upper surface of the convex portions 16 and 26 is the large diameter portion 2 of the rotary tool 250.
52 makes it concave. There are unjoined parts on both sides of the recess.

Next, the connecting member 30 is placed on the seats 17 and 27 of the face plates 11 and 21. The end of the connection member 30 is in contact with the surface of the seat 27. Next, the ends of the connection members 30 are connected to the face plates 11 and 21.
Are temporarily fixed by arc welding. Temporary welding is intermittent. Next, the connection member 30 and the seats 17 and 27 are joined using the friction stir welding apparatus used for friction stir welding of the butted portions of the face plates 12b and 22b. With the rotary tool 250 inserted from above into the portion where the connecting member 30 and the seat 27 are overlapped, the rotary tool 250 is moved along the joining line to perform friction stir welding. The rotary tool 250 is inclined with respect to the overlapping surfaces 17 and 27 as in the embodiment of FIG.

The width of the convex part 35 is the large diameter part 2 of the rotary tool 250.
52 is larger than the diameter. A groove 36 is provided at the center of the width of the protrusion 35. The rotation axis of the rotary tool 250 is aligned with the groove 36. For this reason, the position of the rotary tool 250 is an inner position having a portion that is not friction stir welded to the end of the connection member 30. The tip of the small diameter portion 251 of the rotary tool 250 is inserted deeply into the seats 17 and 27. Thereby, lap joining is performed. The lower end of the large diameter portion 252 is a non-convex connecting material 3
0 and the top of the convex portion 35.

The upper surface of the convex portion 35 is concave by the large diameter portion 252 of the rotary tool 250. There are unjoined parts on both sides of the recess. The sensor of the friction stir welding apparatus detects the groove 36 and moves the rotary tool 250 along the groove 36. For this reason, the positional relationship between the rotary tool 250 and the sensor when joining the butted portions of the face plates 12b and 22b can be used as it is. The relationship between the other rotary tools and the joints is as described above.

The axis of the rotary tool 250 has two ribs 13
A, 13B (23A, 23B) lies on a vertical line passing at or near the vertex of the truss. For eccentricity, the thickness of the ribs 13A, 13B (23A, 23B) is increased, the shape of the arc connecting the rib and the face plate, the thickness of the connection portion,
Corresponding to the thickness of 7, 27, etc. The joining of the connecting member 30 is performed by joining with the seat 17 and then with the seat 27.
If two rotating tools are used, both ends of the connecting member 30 can be joined at the same time.

According to this, the joining of the connecting members 30 is lap joining, not butt joining. For this reason, the connecting member 30 can be joined even if the gap between the two hollow profiles 10 and 20 changes due to the manufacturing tolerance of the two hollow profiles 10 and 20 and the tolerance of the interval between the arrangement of the two hollow profiles. is there. Particularly, when a large number of hollow members are arranged and joined at one time, an error increases. In this case, since it is lap joining, it can be easily joined.

Further, the joining of both sides of the hollow profile can be performed from one side. For this reason, there is no need to invert the structure in which one surface is joined. Therefore, it can be manufactured at low cost and with high precision.

The outer surface of the joint between the face plates 12b and 22b can be joined flat. The convex portions 16, 26, and 35 are located inside the structure or inside the vehicle, and are required to have a smooth surface (the outer surface side,
Outside). In addition, there is no concave portion formed by cutting with the rotary tool on the outside of the vehicle. For this reason, the cutting of the convex portion can be made unnecessary, and the vehicle body can be manufactured at low cost.

The insertion force at the time of joining the connecting members 30 is as follows:
Two ribs 13 arranged toward the axis of the rotary tool 250
A, 13B (23A, 23B). For this reason, the bending of the ribs 13A, 13B (23A, 23B) can be suppressed. 13A and 13B (23A and 23B) can be made thinner and lighter. Of course, the bending of the face plates 11, 21, 30 can also be suppressed. Rib 13
Since the beds 240 supporting A, 13B (23A, 23B) are at the same height, bending of the face plates 12, 22 can also be prevented.

Further, considering the case of using as a structure after joining, substantially all of the structure is constituted by a truss structure. The joint between the hollow members 10 and 20 also has a truss structure. Therefore, the out-of-plane bending rigidity is improved, and the weight can be reduced. Since the connecting members 30, the face plates 12b and 22b and the ribs 13A and 23A between the ribs 13A and 23A substantially constitute a truss, these portions are not particularly weak. However, the thickness should be considered.

Further, the inclination angle θ1 of the ribs 13A and 23A can be made larger than the inclination angle θ2 of the ribs 13B and 23B. According to this, the width of the connection member 30 becomes large, and it becomes necessary to increase the thickness of the connection member 30, and the weight becomes large. However, it can be used when a large opening is required for insertion of the friction stir welding apparatus. By making the inclination angles θ1 and θ2 of the rib the same, it is possible to form an isosceles triangle. According to this, the plate thickness of the ribs 13A and 13B (23A and 23B) can be made the same. The thickness of the ribs 13A and 23A is shown in FIG.
It could be thinner than However, if the size of the isosceles triangular truss is made the same as the size of the truss at other places, the width of the connecting member 30 becomes large.

However, the two ribs 13A, 13B (23
If the inclination angles θ1 and θ2 of A, 23B) are the inclination angles θ1 of FIG. 5, the truss at the end can be made a small isosceles triangle. The size of the base of the truss at this end is smaller than the size of the base of the truss at other places. According to this,
The distance from the intersection of the rib 13B (23B) and the face plate 12 (22) to the end of the hollow profile 10 (20) can be reduced. Therefore, the width of the connecting member 30 can be made similar to the width of the connecting member 30 in FIG.

The pitch of all the trusses including the connecting member 30 is the same. Except for the end truss, the size of the truss is the same. For this reason, the design of the hollow profile can be standardized. Two ribs 13A, 13B (23A, 23B)
May be located on the outer surface side of the face plates 21 and 31. Also, the two ribs 13A, 13B (23A, 23
The rotary tool 250 may be inserted at an angle toward the middle of the angle formed by B). The axis in this case is directed to the top of the truss.

In the above embodiment, the joining of the connecting members 30 is performed by friction stir welding, but may be performed in combination with arc welding. Since the friction stir welding is lap welding, the joining strength is lower than that of butt welding. Therefore, the butted portions of the end portions of the connecting members 30 and the face plates 21 and 31 are arc-welded. The location of the arc welding is, for example, a region where the strength is low. Also, arc welding can be used for repair.

In the above embodiment, both ends of the connecting member 30 are joined by friction stir welding, but one end may be joined by friction stir welding and the other end may be joined by arc welding. Since arc welding has a larger distortion, friction stir welding is performed first.

In the above embodiment, the face plates 11, 12, 21, 22
Are parallel, but it is possible to cope with a case where one face plate is inclined with respect to the other face plate. Rib 13
A, 13B (23A, 23B) in the thickness, face plate 1
The plate thickness on the sides 1 and 21 is made larger than that on the face plates 12 and 22.
The reason for increasing the thickness of the face plates 11 and 21 is that the temperature tends to be high during joining.

In the above embodiment, the face plate of the joint is horizontal, but the joint can be similarly performed even if the normal of the face plate of the joint is inclined. This is likely to occur at the joining line at the end of the side structure 201. In this case, the axis of the rotating body is along the normal of the face plate.

The embodiment shown in FIG. 9 will be described. Hollow profile 10C
Is perpendicular to the face plates 11C and 12C (along the normal of the face plate). Face plate 11C and rib 1
At the connection portion with 3C, there is a seat 17C of a concave portion similar to the above. 17Cb is a protruding piece connected to the seat 17C, and
30 appears. The rotating tool 25 is set within the range of the thickness of the rib 13C.
There is a zero rotation axis and a groove 36. In this case, the insertion force during friction stir welding is supported by the rib. The center of the thickness of the rib 13C is located at the center of the width of the seat 17C including the protruding piece 17Cb. The width of the seat 17C including the protruding piece 17Cb is the same as the width of the projection 35. The rib at the end of the other hollow profile can be made in this way.

In the embodiment shown in FIGS. 5 and 9, as in the embodiment shown in FIG. 3, the overlapping surface can be made horizontal and the rotation axis of the rotary tool 250 can be inclined. Inclined convex portions are provided at both ends of the connection members 30 and 130. The connecting portions between the connecting members 30, 130 and the hollow members 10, 10C, 20 are face plates 11, 11
Although they are superimposed on the seats 17, 17C, 27 that are recessed with respect to C, 21, they may be superimposed on the face plates 11, 11, 21.

The technical scope of the present invention is not limited to the language described in each claim or the language described in the section for solving the problem, and is easily replaced by those skilled in the art. It extends to a range.

[0051]

According to the present invention, high-strength welding can be obtained in friction stir welding of the overlapped portion.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a joint according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view after the bonding of FIG. 1;

FIG. 3 is a longitudinal sectional view of a joint according to another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view after the bonding of FIG. 3;

FIG. 5 is a longitudinal sectional view of a main part of a joint according to one embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a joint according to one embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a pair of hollow profiles according to an embodiment of the present invention.

FIG. 8 is a perspective view of a vehicle body of a railway vehicle.

FIG. 9 is a longitudinal sectional view of a main part of another embodiment of the present invention.

[Explanation of symbols]

10, 10C, 20 Hollow profile 11, 11C, 12, 11b, 12C, 21, 22, 2,
2b face plate 13, 13A, 13B, 13C, 23, 23A, 23B
Rib 17, 17C, 27 Seat 30 Connecting material 201 Side structure 202 Roof structure 203 Underframe 240 Bed 250 Rotary tool 310, 320, 330, 340 Member 310b, 320b Inclined surface

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B61D 17/04 B61D 17/04

Claims (3)

[Claims] 1. An extruded section for friction stir welding, characterized in that at one end of a substantially parallel plate, one surface of the plate is inclined. 2. The plate according to claim 1, wherein the inclined portion is a convex portion, and the convex portion and an end of the plate are substantially orthogonal to the plate. An extruded member for friction stir welding, characterized in that ends of the projections are substantially on the same plane. 3. The two face plates are connected by a plurality of ribs, an end of one face plate is located near the rib at an end of the hollow profile, and an end of the other face plate is connected by the rib. The one face plate side of the connecting portion between the end of the one face plate and the rib at the end of the hollow profile is protruded from the end of the one face plate, and is inclined toward the end. An extruded section for friction stir welding.