JP2001212679A - Welded member, welded container and their manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welded member and welded container in which heat input during welding work is minimized regardless of surface conditions of welded joints and a sealing capability with air, liquid and the like is superior, and their manufacturing method. SOLUTION: A welded container is provided with an upper container member 1 in which the upper container member has an opening at a downward portion, and a flange portion 1a extending outwardly from an upper container main body 1b is integrally formed at an entire periphery of the opening; and a lower container member 2 in which the lower container member has an opening at an upward portion, and a flange portion 2a extending outwardly from a lower container body 2b is integrally formed at an entire periphery of the opening portion 2c. Both of the flange portion of these upper and lower container members are superposed each other, and then the superposed flanged portions are temporarily fixed by rivets so that the flanged portions are welded by a friction churning welding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining member, a joining container, and a method of manufacturing the joining member, in which members made of aluminum or aluminum alloy are joined by friction stir welding, and more particularly to an automobile or a motorcycle such as a passenger car, a truck and a bus. TECHNICAL FIELD The present invention relates to a joining member, a joining container, and a manufacturing method thereof suitable for a box-shaped product such as a fuel tank used for a semiconductor device or a vacuum chamber for a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, motorcycles, passenger cars, trucks,
Fuel tanks used for cars such as buses and special vehicles
It is made of steel, synthetic resin, aluminum and various clad plates. As such a fuel tank, a fuel tank made of steel is disclosed in JP-A-8-323487 (conventional example 1). The steel fuel tank described in Conventional Example 1 has two box-shaped members formed of a steel plate and having openings, and a flange portion is formed outwardly on the periphery of the opening of the two box-shaped members. The flange portions of the openings of the two box-shaped members are overlapped, and the flange portions are welded by seam welding.

Further, Japanese Utility Model Laid-Open Publication No. 5-273 discloses a fuel tank made of aluminum or an aluminum alloy which is attached to a truck, an industrial machine or the like, and stores a liquid fuel such as gasoline or light oil. Conventional example 2). The fuel tank described in Conventional Example 2 has an aluminum or aluminum cylindrical tank main body and two end plates for closing both openings of the tank main body, and the inner periphery of the end plate is bent substantially at right angles. Formed inwardly directed flange. Further, a welding joint which is inclined at an inclination angle of about 15 ° toward the inside of the tank is provided on the flange portion. The opening end of the tank body is attached to the welding joint and is welded and fixed by inert gas arc welding. ing. The fuel tank of Conventional Example 2 configured as described above can absorb a dimensional error between the tank body and the end plate, and can easily adjust the size and obtain a clean weld.

[0004]

However, the prior art 1 has a problem that the heat input is large when the flange portions of the steel box-shaped members are overlapped and resistance seam-welded. In particular, when a member having a flange portion made of aluminum or an aluminum alloy instead of steel is seam-welded, the aluminum or aluminum alloy plate is distorted due to a large amount of heat input, and dimensional accuracy is reduced. For example,
When a box-shaped member made of aluminum or an aluminum alloy is used as a fuel tank and welded by seam welding, if the dimensional accuracy is reduced, there is a problem that the hermeticity of gas, liquid, and the like is deteriorated. Since the fuel tank stores a liquid fuel such as gasoline, it is necessary to seal gas components volatilized from the liquid fuel together with the liquid fuel, and it is extremely dangerous if airtightness is deteriorated. Also, in seam welding, if the contact surface between the flange portions is not flat or an oxide film is formed, the resistance becomes high or the resistance becomes non-uniform, so that the heat flow rate further increases, There is also a problem that the heat-affected zone becomes large.

Further, in the technique of the prior art 2, the main body of the fuel tank and the end plate are butted and fixed by inert gas arc welding. In this way, it is necessary to overlap and weld aluminum members. It is necessary to pay attention not only to the surface that directly receives a heat source such as an arc or a laser, but also to the surface properties of the surfaces where the members are in contact.If this is neglected, defects will occur in the welds and further penetration will occur. There is a problem that it is not stable, and the hermeticity of gas and liquid becomes insufficient. When air bubbles are generated in the fusion zone, the weld is solidified earlier than the air bubbles emerge, and the air bubbles remain as blowhole defects. When a mechanical stress is applied to the substrate, cracks are generated and the sealing performance of gas, liquid and the like is deteriorated. Further, in arc welding, since the heat-affected zone by welding is relatively large, the heat-affected zone of the base metal occurs in a wide range. For this reason, there is a problem that the base material near the joint is severely softened, and the base material is deformed and it is difficult to obtain a necessary sealing property.

The present invention has been made in view of the above problems, and is a joining member which has a small heat input during joining and a high strength regardless of the surface properties of the joint, and has excellent sealing properties for gas, liquid and the like. It is an object to provide a joint container and a method for manufacturing the same.

[0007]

A joining member according to the present invention comprises two aluminum or aluminum alloy members having a flange portion, and the flange portions are overlapped with each other and the flange portions are joined by friction stir welding. It is characterized by having been done.

[0008] In the joining container according to the present invention, a flange portion protruding outside is formed over the entire periphery of the opening.
It has a pair of aluminum or aluminum alloy container members, and the flange portions are joined by overlapping these flange portions and performing friction stir welding along the entire peripheral edge thereof.

In the present invention, the flange portions formed on the peripheral edges of the openings of the pair of container members are overlapped with each other, and the overlapped flange portions are joined by friction stir welding. In the case of fusion welding such as arc welding, leakage is likely to occur due to minute defects etc.In contrast, friction stir welding has a small amount of heat input and little heat effect, so distortion or the like due to heat of aluminum or aluminum alloy container members due to heat is small. It is possible to improve the hermeticity of gas, liquid, etc. while maintaining high dimensional accuracy.

The method of manufacturing a joining member according to the present invention comprises the steps of superimposing and temporarily fixing the flange portions of two aluminum or aluminum alloy members having a flange portion, and friction stir welding the flange portions. And characterized in that:

According to the method for manufacturing a joined container according to the present invention, there is provided an upper container member made of aluminum or an aluminum alloy having an opening at a lower portion and a flange portion protruding to the outside over the entire periphery of the opening, and an opening at an upper portion. A step of superposing the lower container member made of aluminum or aluminum alloy on which a flange portion projecting to the outside over the entire periphery of the opening is formed by overlapping the flange portions, and temporarily fixing the flange portion; And friction stir welding the parts along the entire periphery.

In the present invention, since the upper container member and the lower container member are friction stir welded, they are excellent in dimensional accuracy, airtightness, liquid tightness and other hermetic properties, and are temporarily fixed before friction stir welding. Therefore, both members can be more reliably joined. When welding with a groove with a flange overlapped, the contact between the flanges where the upper and lower members overlap is a flat surface, so if it is not fixed properly, deformation of the opening may occur during welding. Or, because the contact portion is flat, the upper and lower members may slip and cause displacement, etc., but by performing friction stir welding after performing temporary fixing, the sideslip and opening of the members to be joined are performed. Thus, it is possible to obtain a desired dimensional accuracy and a stable joint by preventing deformation or the like.

Further, the method of temporarily fixing the joining member and the flange portion of the joining container according to the present invention includes a method of mechanically joining using a self-piercing rivet or mechanical clinching, a method of welding by resistance spot welding, Alternatively, it is possible to adopt a method in which the bending process is performed while the flange portions are overlapped.

When performing friction stir welding, the joining surface of the joining members to be joined or the flange portion of the joining container may be either vertical or horizontal, or may be inclined. In addition, the flange portion where the upper container member and the lower container member are overlapped can be joined without performing temporary fixing.
Further, as the temporary fixing, any method can be used as long as it can fix both members at the time of friction stir welding, and is not limited to the above method.

[0015]

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing each member constituting the joining container according to the first embodiment of the present invention. The joining container of the present embodiment is suitable for a fuel tank for an automobile, and is a joining container made of aluminum or an aluminum alloy and subjected to friction stir welding. As shown in FIG. 1, an upper container member 1 whose lower part is opened,
And a lower container member 2 having an upper opening. The lower container member 2 is integrally formed with a flange portion 2a that is bent outwardly from the lower container main body 2b by approximately 90 ° and protrudes over the entire periphery of the opening 2c. Similarly, the upper container member 1 extends over the entire periphery of the opening.
A flange portion 1a that is bent outward by about 90 [deg.] from b is integrally formed.

FIG. 2 is a side view of the joining container according to the embodiment.
FIG. 3 is a top view thereof. As shown in FIG. 2, the flange portion 1a of the upper container member 1 and the lower container member 2 shown in FIG.
And the flange portion 2a are overlapped. After the two flange portions are temporarily fixed, the flange portions of the two container members are joined by friction stir welding along the entire peripheral edge. Therefore, as shown in FIG. 3, a joining line 4 formed by friction stir welding is formed on the overlapped flange portions.

Next, a description will be given of a method of manufacturing the welding container subjected to friction stir welding according to the present embodiment. First, both flange portions of the upper container member 1 and the lower container member 2 shown in FIG. Next, in order to perform the friction stir welding more securely, the overlapped flange portions are temporarily fixed.

As a temporary fixing method performed before the two flange portions are overlapped and subjected to friction stir welding, a method of mechanically joining using a self-piercing rivet or mechanical clinching, or welding such as resistance spot welding is used. There are methods to do so. In the present embodiment, a self-piercing rivet is used, and a plurality of the rivets are temporarily fixed around the opening in the overlapped flange portion.

Thereafter, the temporarily fixed flange portion is joined along the entire peripheral edge thereof by friction stir welding. Note that the entire periphery of the opening may be joined by friction stir welding along the shape of the opening of the upper and lower container members. FIG. 4 is a top view as viewed from the upper container member 1 of the joining container, and is an enlarged view showing a flange portion. In the friction stir welding, as shown in FIG. 4, for example, a tool that rotates so as to pass over a rivet 5a that is temporarily fixed by overlapping the flange portion 1a of the upper container member 1 and the flange portion of the lower container member. The joint can be moved relative to both flange portions. In this embodiment, the friction stir welding is performed so as to pass over the rivet which is temporarily fixed, but the position of the temporary fixing is changed to the end side 5b of the flange portion 1a of the joining line 4 or the joining line. 4 so that the joining line 4 does not pass over the temporarily fixed rivet. In the case of mechanical clinching or resistance spot welding, temporary fixing can be similarly performed at any position.

Next, the friction stir welding will be described in more detail. FIG. 5 is a schematic view showing a method of friction stir welding. As shown in FIG. 5, first, after the flange portion 1a and the flange portion 2a are overlapped, the flange portion 2a side of the lower container member of the two overlapped flange portions is backing material (surface plate) (shown in FIG. 5). C) Place on top. Next, while rotating the tool 12 having the probe 11 formed at the tip,
Flange 1 from above in the thickness direction of the overlapped flange
a. Then, the contact portion between the rotating probe 11 and the flange portion 1a is softened and plasticized by frictional heat between the probe 11 and the flange portion 1a, and is press-fitted while being agitated by the probe 11, so that the flange portion 1a and the flange portion 2a are pressed. Let it plastically flow. Further, while the probe 11 is rotating, friction stir welding is performed by applying relative pressure to the flanges while applying a constant pressure along the entire peripheral edge of the upper and lower container members at the joining position of the two flanges. Thereby, a joint is formed, and the flange 1a and the flange 2
3a and 3b, and a joining line 4 is formed at the joining position of the flange portion as shown in FIGS. In the present embodiment, the diameter T1 of the tool 12 used for friction stir welding is, for example, 10 mm, and the diameter T2 of the probe 11 is, for example, 4 m.
m, the length h of the probe 11 is, for example, 1.8 mm, the rotational speed of the tool is, for example, 3000 rpm, and the feed speed is, for example, 400 mm / min.

In addition, since the friction stir welding of the present embodiment is performed on the rivet 5a which is temporarily fixed, the portion after the temporary fixing is not left by the joining line 4. Further, if an appropriate material is selected as a material for the rivet, the strength of the friction stir welding portion can be improved by, for example, stirring the driven rivet together with the flange portion with the probe 11. in this way,
The material of the rivet or clinch for temporary fixing for improving the strength is not particularly limited as long as it is higher in strength than the material of the flange portion, but from the viewpoint of recycling, for example, 2000 or 7000 It is preferable to use a high-strength aluminum alloy such as a system.

Further, the temporary fixing position may be a position deviating from the joining line 4, and if the temporary fixing position is set to the outside 5b of the joining line 4 subjected to the friction stir welding, the overlapping flanges are formed by the friction stir welding. It can be prevented that the ends of the portion 1a and the flange portion 2a are turned up and the accuracy of the overlapping is reduced. In addition, as a temporary fixing, when spot welding is performed instead of mechanically joining as in this embodiment,
The diameter of the electrode is 16 mm, for example, and the tip radius is 75 m, for example.
The welding can be performed with a pressure of, for example, 2.7 kN and a welding current of, for example, 25 kA.
Also, without performing such temporary fixing, the friction stir welding can be directly performed after the upper and lower container members are overlapped. Furthermore, the method of the temporary fixing is not limited to the above-described method as long as the position of the upper and lower container members can be fixed to the extent that the positions thereof do not shift during friction stir welding.

In this embodiment, the friction stir welding is performed by pushing the rotating tool up against the flanges of the upper and lower container members while keeping the flanges horizontal. The upper and lower container members may be friction stir welded to the upper and lower container members in such a state that the upper and lower container members are vertical.

According to the first embodiment of the present invention, the flanges of two container members each having an opening and having a flange on the periphery of the opening are overlapped, and the flanges are joined by friction stir welding. To join, at the flange
No special consideration is required for joining the surface of the flange portion where the probe is press-fitted and the surface where the two flange portions are in contact, and therefore, stable joint performance is exhibited regardless of the characteristics of these surfaces. Can be. Further, since friction stir welding is performed, the amount of heat input is smaller than that of fusion welding such as arc welding, and the influence of distortion or the like due to heat of the joining member is small. Therefore, it is suitable for joining of a joining container that requires tightness of gas and liquid, such as a box-shaped product such as a tank as in the present embodiment, and can obtain extremely excellent tightness of gas and liquid. it can.

Further, since the groove having the flange portion is overlapped and welded, the upper and lower container members are in flat contact. Therefore, if not properly fixed, deformation of the opening and slippage on the surface of the flange portion may easily occur during welding, but in this embodiment, temporary fixing is performed before friction stir welding. Therefore, the upper and lower container members do not slide sideways, suppress deformation such as opening, and secure a stable joint and desired dimensional accuracy. In particular, since friction stir welding does not use a filler material, even if it is friction stir welding directly to the temporarily fixed portion, the components of the aluminum or aluminum alloy forming the upper and lower container members do not change,
A stable joint can be created.

Next, a second embodiment of the present invention will be described. In this embodiment, after the upper container member and the lower container member are overlapped, the temporary fixing is performed by bending the end of the overlapped flange portion. FIG. 6 is a schematic side view showing the joining container of this embodiment. As shown in FIG. 6, as in the first embodiment, after the two flange portions of the upper container member 1 and the lower container member 2 each having an opening and having a flange formed on the periphery of the opening are overlapped. The flange portion is turned back to, for example, the upper container member 1 side, and the flange portion 1a of the upper container member 1 is turned back.
The bent flanges are bent so that they touch each other. Then, as in the first embodiment, the probe is moved relative to the flange portion by friction stir welding at a position where the flange portion does not overlap by bending, along the shape of the opening of the upper container body 1a. And join.

According to the second embodiment, since the joining container is formed by friction stir welding, the same effect as in the first embodiment can be obtained. Further, even when the temporary fixing is performed and the upper and lower members are fixed in this way, as in the case of the self-piercing rivet of the first embodiment, the upper and lower container members are suppressed from sliding and opening deformation, and are stable. Joints and desired dimensional accuracy can be obtained. Furthermore, since the flange portion is folded back by bending, the folded end portion has four layers, and the strength is improved.

In the first and second embodiments, the upper container member and the lower container member may or may not have the same shape as long as the shape and size of the openings are equal.

Next, a bonded container actually manufactured by the method of the present invention will be described. For the upper and lower container members, A51
82, O material, and a plate thickness of 1 mm, this aluminum wrought material has the same shape as the upper and lower container members shown in FIG. It was molded integrally with the projecting container member. Then, after the two container member flange portions were overlapped, temporary fixing was performed by spot welding. For spot welding, electrode diameter 16mm, tip radius 7
A 5 mm electrode was used, the pressing force was 2.7 kN, and the melting current was 25 kA. Thereafter, friction stir welding was performed by friction stir welding. For friction stir welding, the probe diameter is 4.0 mm,
Using a tool with a probe length of 1.8 mm and a tool diameter of 10 mm, the tool rotation speed is 3000 rpm, the feed speed is 400 mm / min, and the flanges of the upper and lower container members are joined around the container body along the entire periphery. did. The joining container made of the aluminum alloy thus formed was able to obtain a stable joint and desired dimensional accuracy.

[0030]

As described in detail above, according to the present invention,
After the two members having the flanges are overlapped so that the flanges overlap, the flanges are joined by friction stir welding, so the heat input is small and the properties of the surfaces of the flanges and the contact surfaces between the flanges are related. And stable joint performance can be obtained. In particular, when the present invention is applied to a fuel tank used for automobiles or motorcycles such as passenger cars, trucks and buses, or a box-shaped product such as a vacuum chamber for semiconductor manufacturing equipment, extremely excellent airtightness and liquid tightness are obtained. It is possible to obtain a hermeticity such as a sealing property.

[Brief description of the drawings]

FIG. 1 is a perspective view showing members constituting a joining container according to a first embodiment of the present invention.

FIG. 2 is a side view of the joining container according to the first embodiment of the present invention.

FIG. 3 is a top view of the joining container according to the first embodiment of the present invention.

FIG. 4 is a top view of the joining container according to the first embodiment of the present invention as viewed from the upper container member 1.

FIG. 5 is a schematic view showing a method of friction stir welding of the present invention.

FIG. 6 is a side view showing a joining container according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1: upper container member 1a, 2a; flange portion 1b, 2b; container body 2c; opening 2: lower container member 4: welding line

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Mitsuo Hino Inventor F-term (reference) 4-7-23 Meiji Station, Naka-ku, Nagoya City, Aichi Prefecture F-term (reference) 4E067 AA05 BG00 DA00 EA00 EA07 EB06 EC03

Claims (6)

[Claims] 1. A joining member comprising two aluminum or aluminum alloy members having a flange portion, wherein the flange portions are overlapped and joined by friction stir welding of the flange portions. 2. A pair of aluminum or aluminum alloy container members each having a flange portion protruding to the outside over the entire periphery of the opening, and the flange portions are overlapped with each other. A joining container characterized by being joined by friction stir welding along the entire periphery. 3. A joining method comprising: a step of superimposing and temporarily fixing the flange portions of two aluminum or aluminum alloy members having a flange portion; and a process of friction stir welding the flange portions. Manufacturing method of the member. 4. The step of temporarily fixing the flange portion may be performed by mechanical joining using a self-drilling rivet or mechanical clinching, welding by resistance spot welding, or while the flange portions are stacked. The method according to claim 3, wherein the method is a bending process. 5. An aluminum or aluminum alloy upper container member having a lower portion opened and formed with a flange portion projecting to the outside over the entire periphery of the opening portion, and an upper portion opened over the entire periphery of the opening portion. A step of superimposing the lower portion made of aluminum or aluminum alloy having a flange portion protruding to the outside with the flange portions and temporarily fixing the flange portion, and frictionally stirring the flange portion along the entire periphery. And a joining step. 6. The step of temporarily fixing the flange portion may be performed by mechanical joining using a self-drilling rivet or mechanical clinching, welding by resistance spot welding, or while the flange portions are stacked. The method according to claim 5, wherein the method is a bending process.