JPH0960728A - Pressure container made of aluminum or aluminum alloy and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the pressure container made of aluminum or aluminum alloys and its manufacture, which is low in manufacturing cost, is light in weight but high in strength, and also is simple in manufacturing processes. SOLUTION: The main body part 12 of the pressure container 11 is formed through drawing an aluminum plate, and an end plate 15 made out of an aluminum plate is disposed at the opening part of the main body part 12. The main body part 12 is welded to the end plate 15 at the welding part 14 by laser welding. The welding part 14 for laser welding makes a line over the end plate 15 a welding orbit, which conforms to the wall thick center part of an end face at the opening part of the main body part 12, welding is processed by one path from the starting point of welding to its ending point, the ending point of welding is piled up to its starting point, and concurrently, let welding be continued to its end until laser energy is gradually attenuated to zero. Thus as mentioned above, the pressure container made of aluminum or aluminum alloys can thereby be manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for an air tank for a brake of a transportation machine, has a low manufacturing cost, is lightweight and has high strength, and has a simple manufacturing process. And a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, in automobiles, railroad cars, transportation machines for ships and the like, there has been a demand for improvement in fuel consumption and speedup, and lighter structures have been adopted. As a material for these structures, lightweight aluminum or aluminum alloy materials have come to be used in place of steel. Hereinafter, the aluminum or aluminum alloy material is generically referred to simply as the aluminum material. In particular, air tanks for brakes used in trucks, etc. are required to be lighter due to the increase in the number of installations due to the strengthening of brake systems such as ABS and the tightening of regulations on exhaust gas and load capacity. Instead, the demand for pressure vessels made of aluminum is increasing.

[0003] In a pressure vessel, usually, an open tip portion of a plate material bent into a cylindrical shape is welded to form a body portion, and when a plurality of tank chambers are required inside this, a partition plate is introduced inside. Then, the partition plate and the inner surface of the body are circumferentially fillet-welded to form a tank chamber, and then the open front end of the body and the end plate are circumferentially butt-welded together. Arc welding is generally used for these weldings.

Since MIG welding and TIG welding have good appearance of the bead surface of the welded portion, they have been positively introduced to some metal materials such as aluminum materials. These arc welds are also used for welding.

However, in MIG welding and TIG welding, it is difficult to control the amount of welding, and the heat-affected zone becomes wide due to the wide welding bead, so that the strength of the welded portion cannot be obtained. Further, the shallow penetration depth also causes a decrease in strength.

FIG. 7 is a perspective view showing a conventional pressure vessel manufactured by arc welding.

As shown in FIG. 7, the body 72 of the pressure vessel 71 is formed by bending an aluminum plate material.
The open front end of this plate material is butt-welded at the welded portion 74a to form a cylindrical shape. Then, in order to provide a tank chamber inside the pressure vessel 71, a partition plate (not shown) is arranged in the cylindrical body portion 72, and the partition plate and the inner surface of the body portion 72 form a circle at the welded portion 74b. Arc welded by perimeter fillet welding. An end plate 75 is arranged at the open end of the body 72, and the open end of the body 72 and the circumferential part of the end plate 75 are arc-welded at the welded portion 74c by circumferential butt welding.

On the other hand, in the circumferential welding, there has been devised a welding method in which a welding orbit of one round is welded by high-energy beam welding, and then the energy beam is reduced while removing the welded portion from the welding orbit (Japanese Patent Laid-Open No. H06-6). -285651
Issue).

[0009]

However, in the method shown in FIG. 7 for manufacturing a pressure vessel by arc welding, there is a welded portion 74a in the longitudinal direction of the body portion 72, and it is necessary to estimate the joint efficiency to be low. By increasing the wall thickness to strengthen the joint, the pressure vessel 71
However, there is a problem that the weight increases. Also, the partition plate 7
In the process of processing 3 and the end plate 75 and welding them, there are many welding points and it is necessary to prepare and replace a fixing jig for welding each member, which complicates the manufacturing process and The cost is also high.

Further, in the method of circumferential welding by high energy beam welding while removing the end point of the welded portion from the welding track, the heat-affected zone spreads due to the welding end point deviated from the track, and the tensile strength after welding decreases. , Is difficult to apply to pressure vessels. This phenomenon occurs remarkably in the case of aluminum. In addition, craters are generated in the portion where the laser beam deviates from the welding track, which causes a decrease in strength.

The present invention has been made in view of the above problems, and is an aluminum or aluminum alloy pressure vessel having a low manufacturing cost, a light weight, a high strength, and a simple manufacturing process, and a manufacturing method thereof. The purpose is to provide.

[0012]

An aluminum or aluminum alloy pressure vessel according to the present invention is an aluminum or aluminum alloy pressure vessel comprising a main body portion having an opening and an end plate disposed in the opening, wherein the main body is The portion and the end plate are aligned with the end face of the opening of the main body, and the start portion and the end portion of the welding line on the end plate overlap within the width of the welding line, and the width of the welding line gradually increases from the welding start point. It is characterized by decreasing.

A plurality of the main body portions may be arranged, and the welding line may be located on the end plate that aligns with the end face of the opening of the main body portion and on the end plate that connects the plurality of main body portions.

The main body can be formed by drawing or extruding.

Further, it is preferable that the welded portion is located on an end plate which is aligned with the center portion of the thickness of the end face of the opening.

In the method of manufacturing a pressure vessel made of aluminum or aluminum alloy according to the present invention, laser welding is performed at one welding line from the starting point to the ending point of welding, and the welding ending point is overlapped with the welding starting point. , The laser energy is attenuated until it becomes zero.

[0017]

In the present invention, an aluminum extruded profile having one or more hollow portions or one or more drawn aluminum processed materials is used as a main body, and a mirror plate made of an aluminum plate material is arranged in the opening. Then, the aluminum pressure vessel is manufactured by laser welding the opening end portion and the plate material.

Since the aluminum pressure vessel thus constructed does not have a welded portion in the longitudinal direction of the body of the conventional pressure vessel, the joint efficiency (strength of joint portion / mother strength) in the vessel safety rule of the high pressure gas control method is Η is the strength of the material
= 1 can be considered. Therefore, it is not necessary to increase the wall thickness in order to strengthen the joint portion, and it is possible to reduce the weight of the pressure vessel by reducing the wall thickness.

Since the laser welding method has a high energy density, it has been widely used as a welding method for steel materials and the like as a welding method that can obtain high-speed, high-efficiency, small distortion and deep penetration. Further, in laser welding, a welding line having a two-dimensional curve or corner is NC (numerical co
It has the advantage that it can be controlled by the control method, and the welding line can be freely drawn on a flat plate.

In the present invention, by utilizing the advantages of the laser welding method as described above, the pressure vessel can be manufactured only by welding a predetermined welding track on a flat plate. By cooperating, welding lines on various flat plates can be welded. Therefore, according to the present invention, aluminum materials of any shape can be joined with a small strain. Further, when the laser welding is performed using the central portion of the thickness of the opening end of the pressure vessel body as the welding track, the opening end can be sealed by the lap joint by deep penetration.

Further, in the present invention, laser welding is performed so as to pass on one welding line from the welding start point to the welding end point, the welding end point is overlapped with the welding start point, and the laser energy is set to 0. Aluminum materials are welded to each other by gradually attenuating until

By gradually attenuating the laser energy in this way, the welding bead converges smoothly, and a crater does not form a bead shape in which the end point of welding is dented, thereby preventing weld cracking by the crater. be able to. In addition, by overlapping the welding end point with the welding start point, the steady base metal portion, which does not require welding, is not affected by the welding heat, and the reduction in strength can be prevented.

Further, since it is possible to join with one welding line from the starting point of welding to the ending point of welding, the welding conditions are optimized and the welding jig is replaced according to the change of the welding direction or the joint shape. No complicated steps such as welding are required, and welding can be completed with one setting. Therefore, the pressure vessel according to the method of the present invention can be manufactured at an extremely low manufacturing cost as compared with the conventional manufacturing method.

There are no particular restrictions on the welding conditions for laser welding used in the present invention. There is no limitation on the laser itself used. For melting aluminum, for example, when using a carbon dioxide gas laser, about 3 kW, YA
When using a G laser, it is preferable to irradiate with an output of about 2 kW or more. As described above, the welding conditions such as the laser output and the welding speed can be arbitrarily selected according to the type of laser used, the thickness and shape of the aluminum material, and the like. Further, the flow rate of the shield gas also differs depending on the welding conditions and is not particularly specified, but in order to obtain a good bead shape, it is preferable to flow the shield gas in the range of about 5 to 30 liters per minute.

Further, the optimum attenuation processing time and attenuation processing length of the welding end portion are not specified because they differ depending on the laser output and welding conditions, but the processing length is at least 1.
Desirably, it is about 0 mm. Further, the bead width of laser welding is preferably set within a range of 3 to 10 mm in consideration of the laser output and the plate pressure of the aluminum material. When the thickness of the body member is about 3 mm or more, welding can be performed by irradiating the laser beam in multiple passes while shifting the welding track.

[0026]

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

FIG. 1A is a plan view showing an aluminum pressure vessel according to the first embodiment of the present invention, and FIG. 1B is a schematic sectional view thereof.

As shown in FIG. 1 (b), the main body 12 of the pressure vessel 11 is formed by drawing an aluminum plate, and an end plate 15 made of an aluminum plate is arranged in the opening of the main body 12. Has been done. And the main body 1
2 and the end plate 15 are welded by the welded portion 14.

Further, as shown in FIG. 1 (a), the welded portion 14 of the laser welding has a welding path on the end plate 15 aligned with the center of the thickness of the end face of the opening of the main body 12 from the starting point of welding. Welded in one pass up to the end of welding.

The pressure vessel constructed as described above can be manufactured only by welding on a flat plate, and since there is no welded portion in the longitudinal direction in the main body, the aluminum plate material used can be made thin and lightweight. Can be converted.

FIG. 2 is a plan view showing the end point of the welded portion in this embodiment.

As shown in FIG. 2, the end point 2 of the welded portion 24
7 overlaps within the width of the welded portion 24, and the width of the weld line is gradually reduced by gradually attenuating the laser energy until it becomes zero. Therefore, the portion other than the welded portion 24 is not affected by the welding heat and craters and the like are not generated, so that a high-strength pressure vessel can be obtained.

In order to compare the appearance and the like of the welded portion of the pressure vessel with the welding termination method, pressure vessels were manufactured for this example and the comparative example, and welding was terminated by the method shown in Table 1 below. However, the aluminum materials used, the laser welding conditions, etc. are shown in Table 2 below, and the results are also shown in Table 1 below. The appearance of the welding end point is shown in FIG.

[0034]

[Table 1]

[0035]

[Table 2]

FIG. 3A is a plan view and a schematic cross-sectional view showing the welding end point of Example 1, and FIG. 3B is a plan view and a schematic sectional view showing the welding end point of Comparative Example 1. Sectional view, Figure 3
(C) is a plan view and a schematic cross-sectional view showing a welding end point of Comparative Example 2.

As shown in FIG. 3A, in the first embodiment, the welding start point to the end point passes on one welding track, the welding end point 37a overlaps with the welding start point, and the laser Since the energy was gradually attenuated until it reached 0, crater cracking did not occur and a good weld portion 34a without defects could be obtained.

On the other hand, as shown in FIG. 3 (b), in Comparative Example 1 in which the laser energy was gradually attenuated to 0 while removing the welding end point 37b from the welding track, the base metal excluding the welded portion 34b was used. There was a bead in the part, and it was inferior to Example 1 in appearance and strength. Also, FIG.
As shown in (c), the welded portion 34c is not damped.
In Comparative Example 2 in which the welding was finished above, a bead dent called a crater was generated.

FIG. 4 is a perspective view of an aluminum pressure vessel according to the second embodiment of the present invention.

As shown in FIG. 4, the main body portions 42a, 42b and 42c of the pressure vessel 41 are formed by drawing an aluminum plate material, and the opening portion of each main body portion is made of one aluminum plate material. An end plate 45 is arranged. The main body portions 42a, 42b and 42c and the single end plate 45 are welded along the end portion of the opening end face of each main body portion on the end plate 45 which is aligned with the welding path, and the welded portion 44a,
At 44b and 44c, welding is performed in one pass from the welding start point to the welding end point.

Also in the pressure vessel having the above-mentioned structure, like the pressure vessel shown in FIG. 1, it is possible to manufacture a pressure vessel having a plurality of tank chambers only by welding on a flat plate, and a longitudinal direction is formed in the main body. Since there is no welded part, the aluminum plate material used can be made thinner and lighter in weight. Also, regarding the end point of welding, as shown in FIG.
Similar to the welded part shown in (1), it has a good appearance and high weld strength.

In order to compare the degree of difficulty in the manufacturing process of the pressure vessel, the manufacturing process of this example and the comparative example in which the pressure vessel was manufactured by the conventional technique shown in FIG. 7 were compared.

First, according to the conventional method, the inner diameter is 300 m.
m, the aluminum plate material was bent into a cylindrical shape so that the length in the longitudinal direction was 1000 mm, and the open end portion of the plate material was butt-welded to form a body part, and the volume ratio inside this was 2: 1. After arranging two partition members in order to provide three tank chambers having a ratio of 1, the body and the partition members were circumferentially fillet welded. After that, an end plate was placed at the open tip of the body, and the body and the end plate were circumferentially butt welded together to manufacture a pressure vessel as shown in FIG. 7. This is Comparative Example 3.

Further, in consideration of the inner diameter so that the volume and the volume ratio are equal to those of Comparative Example 3, the aluminum plate material is drawn by a press machine to produce a drawn material to be a main body having a depth of 300 mm. did. Then, by arranging them side by side and arranging a piece of aluminum material to be a mirror plate in the opening, laser welding of the main body and the mirror plate is performed, as shown in FIG.
A pressure vessel as shown in was produced. This is Example 2.

However, the aluminum material used, the welding conditions and the specifications of the pressure vessel after processing are shown in Table 3 below, and the manufacturing conditions are shown in Table 4 below. The thickness of each pressure vessel is J
It was calculated according to ISB 8243 (1981) "Structure of Pressure Vessel" and the vessel safety rule of the High Pressure Gas Control Law. Maximum filling pressure is 10 kgf / mm ² And

[0046]

[Table 3]

In the inner diameter column of the pressure vessel in Table 3 above, the barrel length of Comparative Example 3 was calculated as 300 mm. Further, the total weight of the pressure vessel is the total weight including the end plate and the partition plate, which have the same thickness as the body portion.

[0048]

[Table 4]

The total processing time in Table 4 above was calculated assuming that the time required for each setting such as changing the welding position and exchanging the jig was 5 minutes.

As shown in Tables 3 and 4 above, Example 2
Indicates that there is no longitudinal weld in the body, and the joint efficiency η
Since it can be regarded as 1, the strength was higher than that of Comparative Example 3. Moreover, since the thickness of the aluminum plate material can be reduced, the total weight or the weight is extremely light. Furthermore, in Example 2, the welding length and the number of times of setting were also reduced in the manufacturing process, so that the welding time and the processing time could be significantly shortened.

FIG. 5 (a) is a plan view showing an aluminum pressure vessel according to the third embodiment of the present invention, and FIG. 5 (b) is a schematic sectional view thereof.

As shown in FIG. 5 (b), the pressure vessel 51 according to this embodiment has two main body portions 52 formed by drawing a plate material as in the second embodiment shown in FIG. The main body portions 52 are arranged apart from each other and are welded to each other by the end plate 55 and the welding portion 54.

However, the second embodiment shown in FIG.
5A, the welded portion 54 is connected by a single welding track on the end plate 55, as shown in FIG. 5A. For example, if a welding start point 58 is set on a predetermined welding track and irradiation of laser light is advanced from the starting point 58 in the direction of the arrow on the welding track, the welded part by this laser light will start again. Returning to 58, the laser energy can now be attenuated to complete the weld.

By taking the welding track in this way, it is possible to perform welding from a welding start point to a welding end point with one welding line. Furthermore, since the present embodiment can be applied regardless of how the main body is arranged, the welding process is further simplified, and the number of welded portions on the end plate is only increased. There is nothing to do.

FIG. 6 (a) is a plan view showing an aluminum pressure vessel according to the fourth embodiment of the present invention, and FIG. 6 (b) is a schematic sectional view thereof.

As shown in FIG. 6 (b), the pressure vessel 61 has three tank chambers, but these tank chambers are not individually molded, but integrated by extrusion. The body 62 is used as the main body. One opening of the body portion 62 and a bottom end plate 65b made of an aluminum plate material are welded together by a welded portion 64b, and the other end portion of the body portion 62 is welded through an end plate 65a by a welded portion 64a. ing.

Further, as shown in FIG. 6 (a), since the welded portion 64a of the pressure vessel 61 passes over the end plate 65a aligned with the central portion of the wall thickness of the end portion of the opening of the extruded body portion 62, for example, By setting the welding start point 68 on a predetermined welding track, it is possible to perform welding from the welding start point 68 to the welding end point with one welding line.

As with the first to third embodiments, the pressure vessel constructed in this manner is also lightweight, has high strength, and has a reduced manufacturing cost.

[0059]

As described in detail above, according to the present invention, since the main body of the pressure vessel is formed by drawing or extruding an aluminum material, it is lightweight and has high strength. An alloy pressure vessel can be obtained. In addition, since a plate material serving as an end plate can be installed on the main body and the main body and the end plate can be joined only by laser welding on a plane, the manufacturing process thereof is extremely simple. Further, the welding is performed by one welding track from the welding start point to the end point of the laser welding, the welding end point is overlapped with the welding start point, and the laser energy is attenuated to 0 to end the welded portion. Therefore, it is possible to manufacture an aluminum or aluminum alloy pressure vessel having a welded portion having excellent appearance and strength.

[Brief description of drawings]

1A is a plan view showing an aluminum pressure vessel according to a first embodiment of the present invention, and FIG. 1B is a schematic sectional view thereof.

FIG. 2 is a plan view showing an end point of a welded portion in the first embodiment.

3A is a plan view and a schematic cross-sectional view showing a welding end point of Example 1, and FIG. 3B is a plan view and a schematic cross-sectional view showing a welding end point of Comparative Example 1. (C) is comparative example 2
FIG. 3 is a plan view and a schematic cross-sectional view showing the end point of the welding of FIG.

FIG. 4 is a perspective view of an aluminum pressure vessel according to a second embodiment of the present invention.

5A is a plan view showing an aluminum pressure vessel according to a third embodiment of the present invention, and FIG. 5B is a schematic sectional view thereof.

FIG. 6A is a plan view showing an aluminum pressure vessel according to a fourth embodiment of the present invention, and FIG. 6B is a schematic sectional view thereof.

[Explanation of symbols]

11, 41, 51, 61, 71; pressure vessel 12, 42a, 42b, 42c, 52; body portion 14, 24, 34a, 34b, 34c, 44a, 44
b, 44c, 64a, 54, 64b, 74a, 74b,
74c; welded part 15, 45, 55, 65a, 65b, 75; end plate 27, 37a, 37b, 37c; end point 58, 68; start point 62, 72; trunk

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[Procedure amendment]

[Submission date] December 8, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of drawings]

1A is a plan view showing an aluminum pressure vessel according to a first embodiment of the present invention, and FIG. 1B is a schematic sectional view thereof.

FIG. 2 is a plan view showing an end point of a welded portion in the first embodiment.

3A is a plan view and a schematic cross-sectional view showing a welding end point of Example 1, and FIG. 3B is a plan view and a schematic cross-sectional view showing a welding end point of Comparative Example 1. (C) is comparative example 2
FIG. 3 is a plan view and a schematic cross-sectional view showing the end point of the welding of FIG.

FIG. 4 is a perspective view of an aluminum pressure vessel according to a second embodiment of the present invention.

5A is a plan view showing an aluminum pressure vessel according to a third embodiment of the present invention, and FIG. 5B is a schematic sectional view thereof.

FIG. 6A is a plan view showing an aluminum pressure vessel according to a fourth embodiment of the present invention, and FIG. 6B is a schematic sectional view thereof.

FIG. 7 is a perspective view showing a conventional pressure vessel manufactured by arc welding.

[Explanation of Codes] 11, 41, 51, 61, 71; Pressure Vessel 12, 42a, 42b, 42c, 52; Main Body 14, 24, 34a, 34b, 34c, 44a, 44
b, 44c, 64a, 54, 64b, 74a, 74b,
74c; welded part 15, 45, 55, 65a, 65b, 75; end plate 27, 37a, 37b, 37c; end point 58, 68; start point 62, 72; trunk

Claims (5)

[Claims] 1. A pressure vessel made of aluminum or an aluminum alloy comprising a main body having an opening and a mirror plate disposed in the opening, wherein the main body and the mirror plate are aligned with an end surface of the opening of the main body. While the start and end of the welding line on the end plate overlap within the width of the welding line,
A pressure vessel made of aluminum or an aluminum alloy, wherein the width of the welding line is gradually reduced from the welding start point. 2. A plurality of the main body portions are arranged, the welding line is on the end plate aligned with an end surface of the opening portion of the main body portion,
The aluminum or aluminum alloy pressure vessel according to claim 1, wherein the pressure vessel is located on the end plate that connects the plurality of main body portions. 3. The aluminum or aluminum alloy pressure vessel according to claim 1, wherein the main body is formed by drawing or extruding. 4. The aluminum or aluminum according to any one of claims 1 to 3, wherein the welded portion is located on the end plate which is aligned with the thickness center portion of the end surface of the opening portion. Alloy pressure vessel. 5. The laser welding is performed at one welding line from the welding start point to the welding end point, the welding end point is overlapped with the welding start point, and the laser energy is attenuated to 0. Of manufacturing a pressure vessel made of aluminum or aluminum alloy.