JP2000120997A - High pressure container and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give a high pressure container friction welding of the mirror part of an aluminum alloy having a large amount of magnesium directly to the neck member of stainless steel, though the friction welding was difficult until now. SOLUTION: The top part of a mirror part 2 manufactured of an aluminum.4-6% magnesium alloy is formed in a cylinder body 8. A burr reservoir 9 having a narrow outlet 10 is arranged in a neck member 3 made of a stainless steel and in a joining spot situated opposite to the upper end of the cylinder body 8. The upper end of the cylinder body 8 and the joining spot of the neck member 3 are brought into contact with each other. With burrs protruded through the narrow outlet 10, friction welding is carried out to join together the two members.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding type high-pressure vessel filled with a high-pressure gas and a high-pressure liquid and a method for manufacturing the same.

[0002]

2. Description of the Related Art As an example of a high-pressure vessel made of an aluminum alloy to be filled with a high-pressure gas and a high-pressure liquid, many examples shown in FIG. 10 are commercially available. The material is 5083-O
(Annealed material) is used. The body 1 is manufactured by winding a rectangular plate material into a cylinder, joining both ends together by arc welding. Then, curved mirror sections 2 are joined to both ends of the body section 1 by arc welding. At the center of one mirror part 2, a neck member 3 internally threaded is attached by arc welding. The female screw of the neck member 3 is attached by screwing a valve 4 having an external thread cut on the outer periphery. As shown in the figure on the left, there is a case where a protector 5 is attached so as to surround the valve 4. As shown in the figure on the right, there is a case where a cap 6 is attached instead of the protector 5.

[0003] By the way, pressure tests and airtight tests are to be performed on the high-pressure container. These tests are performed after the connecting portion of the testing machine is screwed into the neck member 3.
However, the female screw of the neck member 3 was easily damaged by the tightening torque when the connecting portion was screwed. The valve 4 was also easily damaged by the tightening torque at the time of screwing.

The inventor of the present invention has continued to study how to prevent breakage of the internal thread of the neck member 3 and has completed one invention, and has filed Japanese Patent Application No. Hei 9-81785.
No. has already been filed. According to the present invention, an aluminum alloy neck member is welded to a mirror portion of an aluminum alloy high-pressure container, a stainless steel intermediate member cylinder is fitted to the neck member, and a flange of the intermediate member is attached to the outside of the neck member. The ends are joined by friction welding. Then, a female screw is cut on the inner periphery of the intermediate member, and a brass valve is screwed. It was pointed out in the specification of this application that direct friction welding between a mirror portion made of an aluminum alloy 5083 having a large amount of magnesium and stainless steel had a joining problem.

[0005]

The inventor of the present invention has conceived to further develop the technology of the above-mentioned application. And
The neck member 3 was made of stainless steel having excellent strength, and a path was searched for a method of directly friction welding the mirror portion 2 made of an aluminum alloy having a large amount of magnesium and the neck member 3 made of stainless steel. As a result of repeated studies and experiments, a sufficient pool was secured toward the mirror portion 2 and a flash pool 9 having a narrow outlet 10 was provided toward the neck member 3 so that the flash protruded from the narrow outlet 10. It has been found that if joining is performed while the welding is being performed, the pressure is concentrated during the friction welding, and a sound joint having excellent sealing properties against high-pressure gas or the like can be obtained.

Although the neck member 3 is made of stainless steel,
Stainless steel is inferior in workability when drilling or the like by cutting. For this reason, when manufacturing the neck member 3 from a solid material such as a round bar by mechanical cutting, the damage to the cutting tool is extremely fast, and the mechanical cutting requires a long time. Therefore, the present inventor has studied whether there is an economical method for manufacturing the neck member 3. First, attention was paid to the fact that stainless steel has about twice the strength of aluminum alloy 5083. And
It has been noticed that if the forming process by pressing is carried out so as to have a lightened portion from the plate material, the material cost can be reduced, the machine cutting process can be reduced, and the highly efficient production of the neck member 3 which is excellent in economic efficiency can be realized. .

The problem to be solved by the present invention is that the mirror portion 2 made of an aluminum alloy having a large amount of magnesium and the neck member 3 made of stainless steel, which have been difficult to perform friction welding, are directly friction welded. According to this approach,
The material for the neck member 3 can be saved, cutting can be reduced, and high-efficiency manufacturing with excellent economy can be realized.

[0008]

In the high-pressure container according to the present invention and the high-pressure container manufactured by the manufacturing method according to the present invention, the top of the mirror section 2 is formed as a cylindrical body 8 and means for concentrating the pressurization are taken. The neck member 3 made of stainless steel is directly joined to the cylindrical body 8 by friction welding. In the case where the neck member 3 has the lightened portion 7, the plate member can be manufactured by press molding or the like.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inventors of the present invention have examined whether there is any good measure for directly friction-welding a stainless steel neck member 3 to an aluminum alloy mirror part 2 having a large amount of magnesium. At this time, it is necessary to sufficiently secure the sealing property of the joint with respect to the high-pressure gas and the high-pressure liquid, and it is also necessary to use a method that is excellent in economic efficiency. As a result of repeated trial and error, the present invention was able to be completed. An embodiment of the present invention will be described in detail.

In the high-pressure container according to the present invention and the high-pressure container manufactured by the manufacturing method according to the present invention, as the amount of magnesium increases, the strength of the base material increases and the container can be made thinner. Therefore, it is desirable to increase the amount of magnesium. This type of high-pressure vessel is subject to the High Pressure Gas Safety Law, and Article 4 of the Welding Container Notice of the same law states that 5052 aluminum alloy is applied to the pressure-resistant part of the vessel.
And 5083 or their equivalents. Since it is important to reduce the weight of the container, a strong
083 is selected, but it is desirable that the amount of magnesium be 4 to 6% as a base material of the mirror portion 2 including a material equivalent to 5083.

[0011] Further, Article 4 stipulates a material to be applied to a pressure-resistant part of a stainless steel high-pressure vessel.
S304 and SUS316 or materials equivalent thereto. It also stipulates that dissimilar material joining between the aluminum alloy and the stainless steel is allowed. Therefore, in the high-pressure container according to the present invention and the high-pressure container manufactured by the manufacturing method according to the present invention, the neck member 3 is manufactured from the stainless steel so that the screw portion is less damaged.

[0012] As shown in FIG.
May be manufactured by machine cutting a solid material such as a round bar. However, this method increases the manufacturing cost due to the poor machinability and manufacturing efficiency of stainless steel. Therefore, as shown in FIG. 2 and FIG.
It is desirable to provide. Such a thing can be manufactured by press-forming and forging a plate material. Not only can material costs be saved, but also highly efficient manufacturing can be achieved, and the neck member 3 excellent in economy can be obtained.
Note that a male screw for attaching the cap 6 may or may not be provided on the outer periphery of the neck member 3.

As shown in FIG. 1 and the like, the top of the mirror portion 2 is formed in a cylindrical body 8, the upper end of the cylindrical body 8 is abutted against the lower surface of the neck member 3, and joined by friction welding. The reason why the cylindrical body 8 is used is to specify a joint by friction welding. Further, in friction welding between an aluminum alloy and stainless steel, there is a large difference between the two materials in deformation resistance at high temperature, and burrs are generated only from the aluminum alloy side. For this reason, the margin for heat generation is secured only on the aluminum alloy side. Conversely, when a cylindrical body is formed on the neck member 3 side and the lower end of the cylindrical body is abutted against the curved portion of the mirror portion 2 and friction welded, the neck member 3 pierces the mirror portion 2 as shown in FIG. It becomes such a joint. This does not result in a joint having excellent sealing properties against high-pressure gas and the like.

For example, as shown in the upper drawing of FIG. 1, a circular recess having a width larger than the thickness of the cylindrical body 8 is provided in the neck member 3 at a joint portion between the neck member 3 and the cylindrical body 8 of the mirror portion 2. Then, friction welding is performed by abutting the upper end of the cylindrical body 8 against the bottom of the recess. At this time, the depression becomes the burrow 9. The outlet 10 of the pool 9 is made slightly narrower. Then, as shown in the figure below, burrs are generated from the cylindrical body 8 during friction welding, but the burrs fill the burrs 9 and then protrude from the narrow outlet 10. Since the outlet 10 is narrow, the pressure in the pool 9 increases, and the friction torque, which is an important factor for joining during upset, which is the final process of friction welding, increases. For this reason, a sound joint excellent in sealing performance against high-pressure gas or the like is obtained. Moreover, the neck member 3 is joined in a crimped shape as if holding the burrs. The joint strength is further strengthened by the increased strength. The narrower the outlet 10 of the burrow 9, the greater the effect. It is desirable to make the outlet 10 as narrow as possible within a range that does not hinder rotation during friction welding. Since burrs are generated only from the cylindrical body 8 side, the cylindrical body 8
There is no point in providing the pool 9.

In FIG. 1, the burrs 9 of the neck member 3 are provided on both sides of the outer peripheral surface and the inner peripheral surface of the cylindrical body 8 of the mirror portion 2. In the example shown in FIG. 2, a collar 11 is formed on the outer periphery of the neck member 3, and the outer periphery of the collar 11 is bent slightly downward to form a bent piece 12. Bent piece 12
A burrow 9 is formed between the outer peripheral surface of the cylindrical body 8. In the example shown in FIG. 3, a bent piece 12 is formed by bending the outer periphery of the collar 11 vertically downward. As shown in the lower diagram of FIG. 3, the outlet 10 of the burrow 9 becomes narrower during upsetting. Note that a narrow portion may be provided in the middle so as to partition the burrows 9 at two or more places.

The burrs are discharged more toward the outer peripheral surface than from the inner peripheral surface of the cylindrical body 8. On the inner peripheral surface side, the ring-shaped burrs discharge in the direction of decreasing the diameter, so that a large compressive stress is generated in the ring-shaped burrs, and the compressive stress itself suppresses the discharge of the burrs. Therefore, it is desirable to provide the burrs 9 on both sides of the cylindrical body 8 or only on the outer peripheral surface side. In this case, post-processing of deburring may not be necessary. It does not make much sense to provide it only on the inner peripheral surface side.

In order to provide the burrs 9 on the inner peripheral surface side of the cylindrical body 8 in the case of the neck member 3 having the lightening portion 7 as shown in FIG.
The burrs 9 may be provided on the jig at positions corresponding to the inner peripheral surface side of the cylindrical body 8. A bearing may be provided between the jig and the neck member 3 so that the jig does not interlock with rotation or stop of the neck member 3. This is to prevent the jig and the burrs from joining by friction welding.

The cylindrical body 8 of the mirror section 2 needs to be longer than a length that allows a sufficient margin for the burrs to protrude from the narrow outlet 10 of the burrs 9 during friction welding. This is because the pressure is concentrated and the friction torque is increased to obtain a sound joint excellent in sealing performance against high-pressure gas and the like. As shown in FIG. 5, the cylindrical body 8 may be formed by forming a curved portion 13 of the mirror portion 2, and then performing drilling and burring. Alternatively, as shown in FIG. 6, the curved portion 13 may be formed after the cylindrical body 8 is formed. Bending part 13 and cylindrical body 8
And may be formed simultaneously. As described above, the cylindrical body 8 has to be longer than a length that allows a side margin, but preforming or simultaneous forming is suitable for making the cylindrical body 8 longer. In the case of a high-pressure vessel to which the protector 5 is attached,
No screws are needed to attach the cap 6. Therefore, as shown in FIGS. 7 and 8, it is more effective to make the cylindrical body 8 longer. In this case, pre-molding or simultaneous molding is better.

When the neck member 3 is formed from a plate by press working, it may be performed in three steps shown in FIG. That is, the first step is a step of forming the mounting portion of the valve 4 by deep drawing the disk, the second step is a step of forming the lightening portion 7, the collar 11, and the bent piece 12, and the third step is drilling and folding. This is a crimping step of squeezing the bent piece 12 inward. The central hole may be punched with a press. When the protector 5 is attached, the shape of the neck member 3 may be as shown in FIG. Then, a female screw for mounting the valve 4 is processed. If necessary, a male screw for attaching the cap 6 is processed.

As the friction welding method, inertial friction welding or brake friction welding may be used. It is easier to set the allowance for causing the burrs to protrude from the burrs 9 with the brake type.

[0021]

EXAMPLES A 30 kg high-pressure container was manufactured under the conditions shown in Table 1.

[0022]

[Table 1]

The material of the body part 1 and the mirror part 2 is an aluminum alloy 5083 (plate thickness 4.5 mm), and the material of the neck member 3 is SUS304 stainless steel. No. shown in Table 1.
1 relates to the present invention. The structure of the neck member 3 was as shown in FIG. 1 and was manufactured by mechanically cutting a round bar having a diameter of 110 mm. No. 2 also relates to the present invention. A neck member 3 was manufactured by press-molding a 3 mm plate material. No. 3 is a comparative example, and the neck member 3 is N
o. Same as 1 The cylindrical body 8 of the mirror section 2 was formed by burring, and the length of the cylindrical body 8 was set to be as small as 5 mm in order to examine the effect of the offset in friction welding.

No. 3.0MPa for 1-3
A pressure test was performed at a water pressure of. Thereafter, an air tightness test was performed at an air pressure of 1.8 MPa. Table 2 shows the results of both tests.

[0025]

[Table 2]

No. 1 and No. 1 In case 2, no leakage was observed in high-pressure water or high-pressure air.
In the subsequent burst test using high-pressure water, no abnormality was found in the friction welded portion between the mirror part 2 and the neck member 3 at all.
It was destroyed at the location of the torso 1. On the other hand, in Comparative Example No.
In the case of No. 3, the pressure test revealed that the mirror part 2 and the neck member 3 were not sufficiently joined, and the subsequent test was stopped.

No. The time required to manufacture the neck member 3 in each of the cases 1, 2, and 3 is as follows. N
o. 1 and No. 1 While the neck member 3 of No. 3 required about 2 hours, Two could be made in less than 5 minutes. It has been found that manufacturing the neck member 3 shown in FIG. 2 in the step shown in FIG. 9 is extremely efficient.

[0028]

According to the present invention, direct friction welding between the mirror member 2 made of aluminum and 4 to 6% magnesium alloy and the neck member 3 made of stainless steel, which has been difficult in the past, has become possible. And the joining part excellent in the sealing property with respect to high pressure gas etc. was able to be obtained, and the high efficiency joining method was able to be provided.

The neck member 3 having the hollow portion 7 can be manufactured by press-forming a plate material or the like. For this reason, the material cost can be reduced and the production can be performed with high efficiency, resulting in excellent economy.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing another embodiment.

FIG. 3 is a longitudinal sectional view showing still another embodiment.

FIG. 4 is a longitudinal sectional view showing a comparative example.

FIG. 5 is a longitudinal sectional view showing still another embodiment.

FIG. 6 is a longitudinal sectional view showing still another embodiment.

FIG. 7 is a longitudinal sectional view showing still another embodiment.

FIG. 8 is a longitudinal sectional view showing still another embodiment.

FIG. 9 is a longitudinal sectional view showing still another embodiment.

FIG. 10 is a one-side sectional view showing a conventional example.

[Explanation of symbols]

2 Mirror part 3 Neck member 7 Lightening part 8 Cylindrical body 9 Burr pool 10 Exit 13 Curved part

Claims (7)

[Claims] 1. A state in which a burr (9) having a narrow outlet (10) at least on the outer peripheral surface side of a cylindrical body (8) is provided in a neck member (3), and the burr protrudes from the narrow outlet (10). And a cylindrical body (8) formed on the top of a mirror part (2) made of aluminum and a 4-6% magnesium alloy.
A high-pressure vessel in which the lower surface of a stainless steel neck member (3) is joined by friction welding. 2. The high-pressure container according to claim 1, wherein the neck member has a hollow portion. 3. A mirror (2) made of aluminum and a 4-6% magnesium-based alloy is formed with a cylindrical body (8) at the top, and a neck (3) made of stainless steel is attached to the cylindrical body (8). The width of the portion facing the upper end of the cylindrical body (8) is larger than the thickness of the cylindrical body (8), and the pool (9) has a narrow outlet (10) at least on the outer peripheral surface side of the cylindrical body (8). ), The cylindrical body (8) being of such a length that a sufficient margin is ensured for the burrs to protrude from its narrow outlet (10) during friction welding, and the upper end of the cylindrical body (8) and the neck member are provided. (3) A method of manufacturing a high-pressure container in which the two parts are brought into contact with each other by friction welding while making contact with the joints and protruding burrs from their narrow outlets (10). 4. The method for producing a high-pressure container according to claim 3, wherein the neck member (3) has a hollow portion (7). 5. The method for producing a high-pressure container according to claim 3, wherein the cylindrical body is formed by burring after forming the curved portion of the mirror portion. . 6. A cylindrical body (8) of a mirror part (2) is bent by a curved part (1).
The method for producing a high-pressure container according to claim 3, wherein the molding is performed before the molding of 3) or simultaneously with the molding of the curved portion (13). 7. The method for producing a high-pressure container according to claim 3, wherein the neck member is formed by pressing a plate material.