JP2002059278A - Method of friction stir welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the step-free welding in a weld part in the butt welding of plates. SOLUTION: Butted parts of face plates 12b and 22b of shapes 10 and 20 are friction-stir welded. In the butting, a protruded part at an end of a face plate 22 of the shape 20 is fitted to a recessed part at an end of a face plate 12 of the shape 10. No step is present on an outer surface of the face plates 12 and 22 by the fitting. Next, a rotating tool is inserted in the fitted part from protruded parts 16 and 26 side on one surface side of the face plates 12 and 22, and the other surface side of the face plates 12 and 22 is friction-stir welded smoothly. The step-free butt welding can thus be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for friction stir welding a profile. For example, the present invention is suitable for a friction stir welding method of an extruded aluminum alloy material used for railway vehicles, buildings, and 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 into 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. This is disclosed in JP-A-9-3091.
No. 64 (EP0797043A2).

FIG. 9 of this document shows that the joining of two surfaces of a hollow extruded profile is performed from one side. That is, the plates on one side are abutted, and friction stir welding is performed from the other side. The outer surface of the plate is joined flat. The end of the plate on the one surface is orthogonal to the thickness direction.

FIG. 7 of the above-mentioned document shows that good friction stir welding is achieved by joining members provided with convex portions.

[0005]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 9-309 is disclosed.
Consider a case where two long plates (extruded members) are butt-joined as shown in FIG. 9 of Japanese Patent Publication No. 164 (EP0797043A2). In joining, friction stir welding is performed while the plate at the joint is held down from above. The holding device is a holding bracket or a roller that moves together with the rotary tool. Also, after temporarily welding the two plates at a predetermined pitch,
Press with a roller to perform friction stir welding. When the plate is a long material, the end of the plate may be deformed in a wavy shape in the longitudinal direction. In this case, as shown in FIG. 7, in the abutting portion, the ends of the _two plates B ₁ and B ₂ have a step in the vertical direction. This step can be eliminated by pressing from above.

However, in order to eliminate this step,
It is necessary to reduce the pitch of the holding metal, and the device becomes expensive. Further, in the case of performing friction stir welding after the temporary fixing welding, it is necessary that there is no step at the time of the temporary fixing welding, and there is a similar problem. If temporary welding is performed in a state where a step is formed, the step cannot be eliminated thereafter.

SUMMARY OF THE INVENTION An object of the present invention is to provide a butt-joining of plates in which a joining portion is joined without any step.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to fit a convex portion at an end of a plate of a first profile into a concave portion at an end of a plate of a second profile, and then to engage the fit. The part can be achieved by inserting a rotary tool from one surface side of the plate and flat friction stir welding the other surface side of the plate.

[0009]

1 to 6 show an embodiment of the present invention.
This will be described below. FIG. 1 is an enlarged view of the butt joint of FIG. FIG. 2 is an enlarged view of a butt portion of FIG.
It is a figure which shows the state of the butting part before butting of an extruded shape material, and FIG. 3 has shown the state after butting.
4 is an enlarged view of a main part of FIG. 5, and FIG. 5 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 structure and joining method of the hollow sections 10 and 20 for friction stir welding forming the side structure 201 will be described. The same applies to other parts and other structures.

The hollow profiles 10, 20 are composed of two face plates 11, 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 a bed 240 with the face plates 12, 22 downward. The side of the face plates 11 and 21 faces upward. The rotary tool 250 is inserted into the butted portion 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 protruding portions 16 and 26 projecting toward the inside of the vehicle (ie, toward the face plates 11 and 21). The widths and heights 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. Seat 27 (17) is rib 2
It is at the intersection of 3A (13A) and 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 the same as the width of the projection 35 of the connection member 30. The seat 27 (17) is recessed from the outer surface of the face plate 21 (11).

The end 27b (17b) of the face plate 21 (11)
Is inclined as a groove for arc welding with the connecting member 30.

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 width of the connecting member 30 is two hollow members 10, 2
0 is smaller than the interval between the face plates 11 and 21. The connecting member 30 is an extruded member made of the same material as the hollow members 10 and 20.
The length of the connecting member 30 is the same as the length of the hollow members 10 and 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.

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.

The ribs 13A and 23A are ribs 13B and 23A
(Θ1 is small), the rib 13
The plate thickness of A, 23A is larger than the plate thickness of ribs 13B, 23A. The plate thickness of the ribs 13B and 23B is larger than the plate thickness of the other ribs 13. Ribs 13A, 13B, 13 and face plate 11,
Connections with 12, 21, and 22 are arc-shaped. Further, the thickness of the connection portion is determined from the viewpoint of strength.

The configuration of the ends of the face plates 12b and 22b, that is, the butting portion will be described. At the end of the face plate 22b, there is a trapezoidal protrusion 22c protruding toward the face plate 22b.
A trapezoidal concave portion 12 for receiving a convex portion 22c of the face plate 22b is provided on an end surface 12d of the hollow member adjacent to the end portion of the face plate 12b.
There is c. When the convex portion 22c enters the concave portion 12c, the face plate 12
The lower surfaces (outer surfaces of the vehicle body) 12bc and 22bc of b and 22b are substantially the same.

The end faces 12d of the face plates 12b, 22b,
22d can contact. The end faces 12d and 22d of the face plates 12b and 22b excluding the concave portions 12c and the convex portions 22b are face plates 12b and
22b is substantially orthogonal to the thickness direction. Recess 12c
Is greater in height and depth than that of the protrusion 22c. Recess 1
2c, the upper end of the convex portion 22c is located above the extension of the upper surface (the inner surface of the vehicle body) 12bb, 22bb of the face plates 12b, 22b. That is, the upper ends of the concave portion 12c and the convex portion 22c are inside the convex portions 16 and 26.

The concave portion 12c and the convex portion 22c are
22b is located on the end surface in the direction perpendicular to the thickness direction.

A method of manufacturing this structure will be described. The hollow members 10 and 20 are placed on a bed 40. Next, the face plate 12
b, 22b butted against each other to form a projection 2 at the end of the face plate 22b.
2c is fitted into recess 12c of face plate 12b. As a result, the lower surfaces (outer surfaces of the vehicle body) of the face plates 12c and 22c become substantially the same. If one of the hollow sections is wavy in the vertical direction, the convex section 22c is inserted into the concave section 12c by pressing the hollow section from above. If the hollow profile is wavy in the vertical direction, it will be wavy or nearly straight after the butting. Face plates 12b, 22
The outer surface of b is substantially the same. End faces 12d, 22d
Touch or approach.

Next, the hollow members 10 and 20 are
Fix to 0. Next, the end faces 12d and 22d are temporarily fixed by arc welding from above. Temporary welding is intermittent.

The upper surface of the bed 40 on which the butted portions of the face plates 12b and 22b are placed is flat. Near the butted portion of the face plates 12b, 22b, the ribs 13A, 23A and the face plate 12b,
Near the intersection with 22b, ribs 13B and 23B and face plate 12,
The three near the intersection with 22 are on a bed 240 of 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 with the rotary tool 250 inserted 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 rotary tool 250 has a large diameter portion 252 and a small diameter portion 251 at the tip thereof. The distal end (lower end) of the small diameter portion 251 is located near the lower surfaces of the face plates 12b and 22b. That is, the lower end of the small diameter portion 251 is located below the lower end of the concave portion 12c. The lower end of the large diameter portion 252 is the convex portion 1
It is located between the tops 6 and 26 and the inner surface of the face plates 12b and 22b (the surface on the side of the face plates 11 and 21). Large diameter part 25
The diameter of 2 is smaller than the width formed by the two convex portions 16 and 26. The small diameter portion 251 is a screw. The diameter of the small diameter portion 251 is larger than the depth S of the concave portion 12c. Thus, the uneven portions 12c and 22c of the butted portion can be stirred by the small diameter portion 251. As shown in FIG.
The axis of the rotary tool 250 is positioned at a position １ ／ of the depth S of c.

At the time of friction stir welding, the top surfaces of the projections 16 and 26 are held down by rollers moving together with the rotary tool 250.

The protrusions 16 and 26 are detected by a laser sensor. Thus, the height positions of the convex portions 16 and 26 are obtained, and the insertion amount of the rotary tool 250 is determined. In addition, two convex portions 1
A gap (between the end faces 12d and 22d) between the butting portions 6 and 26 is obtained, and the axis of the rotary tool 250 is made to coincide with this position.

By the friction stir welding, the face plate 12b,
The gap between the butting portions 22b (the gap between the end faces 12d and 22d, the gap between the concave portion 12c and the convex portion 22c) is filled and joined. The source of the metal that fills the gap is the convex 16,
26. The outer surfaces (outside of the vehicle) of the face plates 12b and 22b are joined flat. There are no concave portions or steps of the joining line on the outer surface side of the face plates 12b and 22b.

The upper surfaces of the convex portions 16 and 26 are concave due to the large diameter portion 252 of the rotary tool 250. The protrusions 16 and 26 remain 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. Next, the end of the connection member 30 is attached to the face plate 1.
1 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. Rotary tool 250
Is moved along the joining line in a state where the connecting member 30 and the seat 27 are inserted from above into the overlapped portion, and friction stir welding is performed.

The width of the convex portion 35 is the large diameter portion 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. The tip of the small diameter portion 251 of the rotary tool 250 is
7 deeply inserted. Thereby, lap joining is performed. The lower end of the large diameter portion 252 is located between the upper surface of the non-convex connecting member 30 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. The upper surface of the convex portion 35 is concave by the large diameter portion 252 of the rotary tool 250. The convex portions 35 remain on both sides of the concave portions.

The sensor of the friction stir welding apparatus detects the groove 36 and moves the rotary tool 250 along the groove 36.

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 connection member 30 is joined to the seat 17 and then to 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 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. Also, since the butted portions of the face plates 12b and 26b are fitted by the concave portion 12c and the convex portion 22c, the two face plates 12b and 22b are integrated, and the outer surfaces thereof are substantially the same. Because of this, there is no step as in the past,
After friction stir welding, it is not necessary to cut the outer surface side.
Further, since the thickness of the face plates 11b and 22b does not decrease due to the cutting, the hollow profile can be reduced in weight. Of course, some cutting is performed as needed.

Since the convex portion 22c has a trapezoidal shape, the concave portion 12c
Enter c easily. The size of the tip of the convex part 22c is the end face 22.
The shape can be smaller than the d-side, for example, triangular. On the other hand, for the same purpose, the concave portion 12c has
The shape can be smaller than the side, for example, triangular.

Since the abutting portions of the face plates 12b and 22b have the convex portions 16 and 26, the gap between the convex portion 22c and the concave portion 12c can be filled with metal.

The axis of the rotary tool 250 is the end face 12d of the face plate.
(22d). However, recess 1
If the position at half the depth of 2c is the target position of the axis of the rotary tool 250, the diameter of the small diameter portion 251 can be reduced.

Since the end portions of the face plate are thickened by the convex portions 16 and 26, the concave portions 12c and the convex portions 22c are provided at the end portions of the face plate.
Can be easily installed. For this reason, the convex portions 16 and 26 can be used effectively.

The connection member 30 may be placed on any structure and location that can withstand the load during friction stir welding. For example, JP-A-9-309164 (EP0797043A)
As shown in FIG. 9 of 2).

The profile in the above embodiment was a hollow profile.
No hollow is necessary. In addition, face plates 16, 16b, 22,
22b may have only ribs.

The bed 40 can be replaced by a backing such as a roller.

Further, the one joined in the above manner can be used on the outer surface (visible surface) of a structure such as a building.

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

[0056]

According to the present invention, friction stir welding is performed after fitting the butted portions of the shaped plates, so that the plates can be joined without any step.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view of the butt joint portion of FIG. 1 before butting;

FIG. 3 is a longitudinal sectional view after a butt joint of FIG. 1 has been butted;

FIG. 4 is a longitudinal sectional view of a hollow section at a joint of the hollow sections according to one embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a pair of hollow profiles according to an embodiment of the present invention.

FIG. 6 is a perspective view of a vehicle body of a railway vehicle.

FIG. 7 is a longitudinal sectional view of a conventional butting portion.

[Explanation of symbols]

 10, 20 Hollow profile 12, 12b, 22, 22b Face plate 12c, 16, 22c, 26 Concave portion 12bc, 22bc Outer surface 30 Connecting material 40 Bed 201 Side structure 202 Roof structure 203 Underframe 250 Rotary tool

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunari Fukuyoro 794, Higashi-Toyoi, Kazamatsu-shi, Yamaguchi Prefecture Inside Hitachi Kasado Machine Industry Co., Ltd. (72) Inventor Yoshihiko Ina 794, Higashi-Toyoi, Kazamatsu-shi, Yamaguchi Prefecture Hitachi Kasado Works (72) Inventor Tetsuya Matsunaga 794 Higashi-Toyoi, Kazamatsu-shi, Yamaguchi Prefecture F-term in Kasado Works Hitachi, Ltd. 4E067 AA05 BG00 CA01 DA13 EA00

Claims (7)

[Claims] 1. A projection at an end of a plate of a first profile is fitted into a recess at an end of a plate of a second profile, and then the fitted portion is fitted to one surface of the plate. A friction stir welding method characterized by inserting a rotary tool from the side and flattening the other surface side of the plate by friction stir welding. 2. The friction stir welding method according to claim 1, wherein
A friction stir welding method, wherein the position of the outer diameter of the rotary tool inserted into the fitted portion is positioned deeper than the bottom of the concave portion to perform friction stir welding. 3. The friction stir welding method according to claim 1, wherein
A friction stir welding method, characterized in that friction stir welding is performed using a rotary tool having a diameter greater than the depth of the concave portion of the rotary tool located in the concave portion. 4. The friction stir welding method according to claim 1, wherein
Each of the ends of the plate has a second protrusion projecting in the thickness direction of the plate, and a part of the recess is in the second protrusion, and the second protrusion side And performing friction stir welding by inserting the rotary tool from above. 5. The method of claim 1, wherein:
Each end of the plate has a second protrusion projecting in the thickness direction of the plate, and a part of the protrusion is in the second protrusion, and the second protrusion is provided. A friction stir welding method, wherein the rotary tool is inserted from the side to perform friction stir welding. 6. A projection at an end of a plate of a first profile is fitted into a recess at an end of a plate of a second profile, and then the fitted portion is fitted to one surface of the plate. Insert the rotating tool from the side, friction stir welding the other surface side of the plate flat, and place the one surface of the one obtained by the friction stir welding on the outer surface of the structure, And a method of manufacturing a structure. 7. A projection at an end of the plate of the first profile is fitted into a recess at an end of the plate of the second profile, and the fitted portion is then fitted to one surface of the plate. A rotary tool is inserted from the side, and the other surface side of the plate is friction stir welded flat, and the one surface of the plate obtained by the friction stir welding is positioned on the outer surface of the vehicle body to manufacture the vehicle body A method of manufacturing a vehicle body, characterized in that: