CN217540352U

CN217540352U - Sealing structure of high-pressure hydrogen storage tank

Info

Publication number: CN217540352U
Application number: CN202221668126.2U
Authority: CN
Inventors: 吉田尚弘; 堤雄吾
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2022-10-04
Anticipated expiration: 2032-06-30

Abstract

The utility model provides a sealing structure of a high-pressure hydrogen storage tank. The structure is used for a joint part between one sealing component and the other sealing component in the high-pressure hydrogen storage tank, an O-shaped sealing ring and a protective gasket are arranged in a groove formed on a joint surface of the one sealing component, the O-shaped sealing ring is close to the inner side of the high-pressure hydrogen storage tank, the protective gasket is close to the outer side of the high-pressure hydrogen storage tank, the joint surface of the O-shaped sealing ring and the other sealing component is tightly attached, and the distance between the bottom surface of the groove and the joint surface of the other sealing component is set to be shorter as the distance is closer to the outer side of the high-pressure hydrogen storage tank. Based on the above structure of the utility model, even at low temperature, the O shape sealing washer also can produce sufficient seal face pressure to can prevent the hydrogen leakage in the high pressure hydrogen storage jar.

Description

Sealing structure of high-pressure hydrogen storage tank

Technical Field

The utility model relates to a sealing structure of a high-pressure hydrogen storage tank for a fuel cell vehicle and the like.

Background

Conventionally, in a high-pressure hydrogen storage tank used in a fuel cell vehicle or the like, a sealing structure using an O-ring (rubber) is generally used in order to prevent leakage of hydrogen gas in the tank from a joint portion between one sealing member and the other sealing member.

In this sealing structure, an O-ring and a protection gasket are disposed in a groove formed on a joint surface of one sealing member, and the O-ring is deformed by hydrogen gas pressure, and the deformed O-ring is brought into close contact with a bottom surface of the groove and a joint surface of the other sealing member, thereby preventing leakage of hydrogen gas in the high-pressure hydrogen storage tank.

However, at low temperatures, the rubber elasticity of the O-ring becomes poor due to the reduced activity of the rubber molecules. In this case, the O-ring cannot be sufficiently deformed even if air pressure is applied. Thus, it is difficult to generate sufficient surface pressure on the seal surface, and a problem of hydrogen gas leakage occurs.

In order to solve the above problem, it is conceivable to provide a double groove for disposing the O-ring and the protection washer, but this structure increases the number of parts and the number of grooves to be processed. Therefore, not only the cost is increased, but also the capacity of the tank is reduced since the space for providing the sealing structure is doubled, resulting in a reduction in hydrogen storage efficiency.

SUMMERY OF THE UTILITY MODEL

In view of the above, an object of the present invention is to provide a sealing structure of a high pressure hydrogen storage tank, which has a simple structure and can prevent hydrogen leakage by generating sufficient sealing surface pressure even at a low temperature with an O-ring seal.

As a technical scheme for solving the above-mentioned technical problem, the utility model provides a seal structure of high-pressure hydrogen storage tank, this seal structure of high-pressure hydrogen storage tank be arranged in the high-pressure hydrogen storage tank between a seal part and another seal part the inslot that forms on the faying face of a seal part disposes O shape sealing washer and protection packing ring, just O shape sealing washer is close to the inboard of high-pressure hydrogen storage tank the protection packing ring is close to the outside of high-pressure hydrogen storage tank O shape sealing washer with the faying face of another seal part closely laminates its characterized in that: in a region of the groove where the O-ring is disposed, a distance between a bottom surface of the groove and a coupling surface of the other seal member is set to be shorter as it approaches an outer side of the high-pressure hydrogen tank.

The utility model discloses an above-mentioned high pressure hydrogen storage tank's seal structure's advantage lies in, when hydrogen atmospheric pressure acted on O shape sealing washer, O shape sealing washer can move towards the direction rigid body that is close to the outside of high pressure hydrogen storage tank at the inslot. Since the distance between the bottom surface of the groove and the joint surface of the other seal member is set to be shorter as the distance from the bottom surface of the groove to the outside of the high-pressure hydrogen tank becomes closer to the region in the groove where the O-ring is disposed, the O-ring is displaced to a narrow portion (a portion where the groove depth is shallow) in the groove, and thus the O-ring is compressed in the depth direction of the groove. The O-ring compressed in the depth direction of the groove is further compressed by the hydrogen gas pressure. Thus, even if the O-ring is not sufficiently deformed, a sufficient seal surface pressure required for sealing can be generated. Therefore, by adopting a simple structure in which the distance between the bottom surface of the groove and the joint surface of the other seal member is shorter as it approaches the outside of the high-pressure hydrogen storage tank, the O-ring can generate a sufficient seal surface pressure even at low temperatures, and leakage of hydrogen gas in the high-pressure hydrogen storage tank can be effectively prevented.

In the sealing structure of the high-pressure hydrogen storage tank of the present invention, it is preferable that the O-ring is disposed in the groove so that the depth of the groove is set to be shallower in the region of the O-ring, the more the groove is located outside the high-pressure hydrogen storage tank.

In the above configuration, the depth of the groove is set to be shallower as the groove is closer to the outside of the high-pressure hydrogen storage tank in the region where the O-ring is disposed in the groove, and thus the distance between the bottom surface of the groove and the joint surface of the other seal member can be easily made shorter as the distance is closer to the outside of the high-pressure hydrogen storage tank.

In the seal structure of the high-pressure hydrogen storage tank of the present invention, a region of the joining surface of the other seal member, which region is opposed to the region in the groove where the O-ring is disposed, may be formed as an inclined surface inclined so as to approach the one seal member more toward the outside of the high-pressure hydrogen storage tank.

In the above configuration, the region of the coupling surface of the other seal member facing the region in the groove where the O-ring is disposed is configured as an inclined surface that is inclined so as to approach the one seal member as the distance from the groove bottom surface to the coupling surface of the other seal member becomes closer to the outside of the high-pressure hydrogen storage tank.

Drawings

Fig. 1 is a schematic diagram showing a seal structure of a high-pressure hydrogen storage tank according to a first embodiment of the present invention.

Fig. 2 is a schematic diagram for explaining a sealing structure under the hydrogen gas pressure.

Fig. 3 is a schematic diagram showing a seal structure of a high-pressure hydrogen storage tank according to a second embodiment of the present invention.

Fig. 4 is a schematic diagram showing a seal structure of a high-pressure hydrogen storage tank according to a third embodiment of the present invention.

Fig. 5 is a schematic view showing a sealing structure of a high-pressure hydrogen storage tank of the related art.

Fig. 6 is a schematic diagram for explaining a deformation state when the O-ring in the sealing structure of the high-pressure hydrogen storage tank of the related art is pressurized at normal temperature.

Fig. 7 is a schematic diagram for explaining a deformation state when the O-ring in the sealing structure of the high-pressure hydrogen storage tank of the related art is pressurized at normal temperature.

Fig. 8 is a schematic diagram for explaining a state of deformation when the O-ring seal in the sealing structure of the high-pressure hydrogen storage tank of the related art is pressurized at low temperature.

Fig. 9 is a schematic diagram for explaining a state of deformation when the O-ring in the sealing structure of the high-pressure hydrogen storage tank of the related art is pressurized at low temperature.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the contents described in the following embodiments. Further, the dimensional relationship (length, width, etc.) in each drawing does not reflect the actual dimensional relationship. In fig. 1 to 6 and 8, arrow H indicates the high pressure side (inside of the high pressure hydrogen storage tank) (closed hydrogen gas side), and arrow L indicates the low pressure side (outside of the high pressure hydrogen storage tank) (atmosphere side).

< first embodiment >

Fig. 1 is a schematic diagram showing a seal structure of a high-pressure hydrogen storage tank according to a first embodiment of the present invention. The seal structure is applied to a connection portion between a first seal member (one seal member) 10 and a second seal member (the other seal member) 20 in a high-pressure hydrogen storage tank 1 used on a fuel cell vehicle, for sealing high-pressure hydrogen gas inside the high-pressure hydrogen storage tank 1.

As shown in fig. 1, a groove 11 is formed on the joint surface 10a of the first seal member 10. An O-ring 30 and a protection gasket 40 are disposed in the groove 11, with the O-ring 30 being located close to the inside of the high-pressure hydrogen tank 1 and the protection gasket 40 being located close to the outside of the high-pressure hydrogen tank 1. In other words, the O-ring 30 and the backup ring 40 are arranged in order from the high pressure side H to the low pressure side L in the groove 11.

The O-ring 30 is made of rubber having good gas barrier properties (gas impermeability). The protective washer 40 is made of resin. The O-ring 30 and the protection gasket 40 are respectively in close contact with the joint surface 20a of the second seal member 20 above in the state of being disposed in the groove 11.

In the region of the groove 11 where the protection gasket 40 is disposed, the depth of the groove 11 becomes gradually shallower from the high pressure side H toward the low pressure side L (becomes shallower toward the outside of the high pressure hydrogen tank 1). That is, in the region where the protection gasket 40 is disposed, the bottom surface 11b of the groove 11 is formed as an inclined surface inclined from the high-pressure side H toward the low-pressure side L toward the second seal member 20. Correspondingly, the bottom surface 40a of the protection washer 40 is also formed as an inclined surface.

Here, in order to make the present invention easy to understand, a sealing structure of a high-pressure hydrogen storage tank of the related art will be described first. Fig. 5 is a schematic diagram showing a sealing structure of a high-pressure hydrogen storage tank 101 of the related art. As shown in fig. 5, in the high-pressure hydrogen storage tank 101 according to the related art, similarly, the O-ring 130 and the protection gasket 140 are arranged in the order from the high-pressure side H to the low-pressure side L in the groove 11 formed in the coupling surface 110a of the first seal member 110, and the O-ring 130 and the protection gasket 140 are in close contact with the coupling surface 120a of the second seal member 120 in a state of being disposed in the groove 111.

In the high-pressure hydrogen storage tank 101 according to the related art, the groove 111 has a uniform depth in the region where the O-ring 130 is disposed in the groove 111, that is, the bottom surface 111a of the groove 111 is a flat surface in the region where the O-ring 130 is disposed. On the other hand, in the region where the protection gasket 140 is disposed in the groove 111, the depth of the groove 111 becomes gradually shallower from the high pressure side H toward the low pressure side L. That is, in the region where the protection gasket 140 is disposed, the bottom surface 111b of the groove 11 is formed as an inclined surface inclined from the high-pressure side H toward the low-pressure side L toward the second seal member 120. Correspondingly, the bottom surface 140a of the protection gasket 140 is also inclined.

Fig. 6 and 7 are schematic diagrams for explaining a deformation state when the O-ring 130 in the sealing structure of the high-pressure hydrogen storage tank 101 of the related art is pressurized at normal temperature. When the pressure is applied at normal temperature as indicated by black arrows in fig. 7, the O-ring 130 is compressed by the air pressure, and then largely deformed in a direction perpendicular to the air pressure as indicated by hatched arrows in fig. 7. Therefore, in the conventional sealing structure, when the pressure is applied at normal temperature, as shown in fig. 6, the O-ring 130 is largely deformed in the direction perpendicular to the gas pressure, and therefore, a sufficient surface pressure is generated on the sealing surface (the bottom surface 111a of the groove 111 and the joint surface 120a of the second seal member 120) to prevent the hydrogen gas in the high-pressure hydrogen tank 101 from leaking.

Fig. 8 and 9 are schematic diagrams for explaining a deformation state of the O-ring 130 when the O-ring is pressurized at a low temperature in the sealing structure of the high-pressure hydrogen storage tank 101 of the related art. When the pressure is applied at a low temperature as indicated by black arrows in fig. 9, the O-ring 130 is compressed by the gas pressure, but the rubber elasticity of the O-ring 130 is deteriorated due to the decrease in the activity of the rubber molecules at a low temperature, and therefore, the O-ring 130 is hardly deformed in the direction perpendicular to the gas pressure as indicated by white arrows in fig. 9. Therefore, in the conventional sealing structure, since the O-ring 130 is hardly deformed in the direction perpendicular to the gas pressure when the pressure is applied at low temperature, a sufficient surface pressure is not generated on the sealing surface (the bottom surface 111a of the groove 111 and the joint surface 120a of the second seal member 120) as shown in fig. 8, and there is a possibility that hydrogen gas leaks.

In contrast, in the seal structure of the high-pressure hydrogen storage tank 1 according to the present embodiment, as shown in fig. 1, in the region in the groove 11 where the O-ring 30 is disposed, the depth of the groove 11 (i.e., the distance between the bottom surface 11a and the coupling surface 20a of the second seal member 20) becomes gradually shallower from the high-pressure side H to the low-pressure side L, that is, the distance between the bottom surface 11a and the coupling surface 20a becomes shorter as the distance becomes closer to the outside of the high-pressure hydrogen storage tank 1. Specifically, in the region where the O-ring 3 is disposed, the bottom surface 11a of the groove 11 is formed as an inclined surface (indicated by a thick-line frame in fig. 1) inclined toward the second seal member 20 from the high-pressure side H toward the low-pressure side L. Thus, the depth of the groove 11 becomes shallower as it approaches the outside of the high-pressure hydrogen storage tank 1 (D1 > D2).

Fig. 2 is a schematic diagram for explaining a sealing structure under the hydrogen gas pressure. In the seal structure of the high-pressure hydrogen storage tank 1 of the present embodiment having the above-described structure, when the hydrogen gas pressure acts on the O-ring 30, the O-ring 30 moves toward the low-pressure side rigid body of the high-pressure hydrogen storage tank 1 in the groove 11 as shown in fig. 2. Here, since the distance between the bottom surface 11a of the groove 11 and the coupling surface 20a of the second seal member 20 is set to be gradually shorter from the high pressure side H toward the low pressure side L (shorter as the distance becomes closer to the outside of the high pressure hydrogen storage tank 1) in the region where the O-ring 30 is disposed in the groove 11, the O-ring 30 is displaced to a narrow portion (a shallow portion of the depth of the groove 11) in the groove 11, and the O-ring 30 is compressed in the depth direction (the direction perpendicular to the gas pressure) of the groove 11 as indicated by a white arrow in fig. 2.

Since the O-ring 30 thus compressed in the depth direction of the groove 11 is further compressed by the hydrogen gas pressure, a sufficient seal surface pressure required for sealing can be generated even if the O-ring 30 is not sufficiently deformed. Therefore, by adopting a simple structure in which the distance between the bottom surface 11a of the groove 11 and the joint surface 20a of the second seal member 20 is gradually shortened from the high pressure side H toward the low pressure side L, the O-ring 30 can generate a sufficient seal surface pressure even at low temperatures, and leakage of hydrogen gas in the high-pressure hydrogen storage tank 1 can be effectively prevented.

Further, since the O-ring 30 is supported by the protection gasket 40, even under high pressure at normal temperature, the O-ring is not damaged by excessive deformation, exposure, or the like, and the sealing function can be maintained.

< second embodiment >

The present embodiment is different from the first embodiment in that the bottom surface of the groove is formed as a flat surface and the coupling surface of the second seal member 20 is formed as an inclined surface in the region where the O-ring 30 is disposed in the groove. Hereinafter, only the differences from the first embodiment will be described.

Fig. 3 is a schematic diagram showing the seal structure of the high-pressure hydrogen storage tank 1 of the present embodiment. Unlike the first embodiment, in the high-pressure hydrogen storage tank 1 of the present embodiment, the depth of the groove 11 'is uniform in the region where the O-ring 30 is disposed in the groove 11', that is, the bottom surface 11a 'of the groove 11' is a flat surface in the region where the O-ring 30 is disposed. In the region of the groove 1 'where the backup washer 40 is disposed, the depth of the groove 11' is gradually reduced from the high pressure side H to the low pressure side L, that is, the bottom surface 11b 'of the groove 11' is formed as an inclined surface inclined from the high pressure side H to the low pressure side L toward the second seal member 20 in the region where the backup washer 40 is disposed, as in the first embodiment.

On the other hand, in the high-pressure hydrogen storage tank 1 of the present embodiment, as shown in fig. 3, the region (the joint surface 20 b) of the joint surface 20a of the second seal member 20 that faces the region in the groove 11' where the O-ring 3 is disposed is configured as a slope that slopes from the high-pressure side H toward the low-pressure side L toward the first seal member 10 (see the thick-line frame in fig. 3).

In this way, in the region where the O-ring 30 is disposed in the groove 11', the distance between the bottom surface 11a ' of the groove 11' and the joining surface 20b of the second seal member 20 becomes gradually shorter from the high pressure side H toward the low pressure side L, so that the O-ring 30 can generate a sufficient sealing surface pressure even at low temperatures, as in the first embodiment, and leakage of hydrogen gas in the high-pressure hydrogen storage tank 1 can be effectively prevented.

< third embodiment >

The present embodiment is different from the first embodiment in that the coupling surface 20b of the second seal member 20 is formed as an inclined surface. Hereinafter, only the differences from the first embodiment will be described.

Fig. 4 is a schematic diagram showing the seal structure of the high-pressure hydrogen storage tank 1 of the present embodiment. In the high-pressure hydrogen storage tank 1 of the present embodiment, as shown in fig. 4, the region (the joint surface 20 b) of the joint surface 20a of the second seal member 20 that faces the region in the groove 11 where the O-ring 30 is disposed is formed as an inclined surface that is inclined from the high-pressure side H toward the low-pressure side L toward the first seal member 10.

That is, in the high-pressure hydrogen storage tank 1 of the present embodiment, the depth of the groove 11 becomes gradually shallower from the high-pressure side H to the low-pressure side L in the region where the O-ring 30 is disposed in the groove 11, and the joining surface 20b of the second seal member 20 facing the region where the O-ring 30 is disposed in the groove 11 also becomes gradually closer to the first seal member 10 side from the high-pressure side H to the low-pressure side L (see thick line frame of fig. 4).

In this way, in the region where the O-ring 30 is disposed in the groove 11, the distance between the bottom surface 11a of the groove 11 and the joint surface 20b of the second seal member 20 is shortened at a higher rate from the high pressure side H to the low pressure side L, and therefore, the O-ring 30 can generate a sufficient seal surface pressure even at a low temperature, and the leakage of hydrogen gas in the high-pressure hydrogen storage tank 1 can be prevented more effectively.

Claims

1. A sealing structure of a high-pressure hydrogen storage tank is used for a joint part between one sealing part and another sealing part in the high-pressure hydrogen storage tank, an O-shaped sealing ring and a protective gasket are arranged in a groove formed on the joint surface of the sealing part, the O-shaped sealing ring is close to the inner side of the high-pressure hydrogen storage tank, the protective gasket is close to the outer side of the high-pressure hydrogen storage tank, and the joint surface of the O-shaped sealing ring and the joint surface of the other sealing part are tightly attached, and the sealing structure is characterized in that:

in a region of the groove where the O-ring is disposed, a distance between a bottom surface of the groove and a coupling surface of the other seal member is set to be shorter as it approaches an outer side of the high-pressure hydrogen tank.

2. The seal structure of a high-pressure hydrogen storage tank according to claim 1, characterized in that:

the depth of the groove is set to be shallower as the groove is closer to the outside of the high-pressure hydrogen storage tank in the region where the O-ring is disposed in the groove.

3. The seal structure of a high-pressure hydrogen storage tank according to claim 1 or 2, characterized in that:

the region of the coupling surface of the other seal member facing the region of the groove in which the O-ring is disposed is configured as an inclined surface that is inclined so as to approach the one seal member as the high-pressure hydrogen tank approaches the outside.