JP2006292005A - Gas seal structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas seal structure capable of maintaining a sealing function by suppressing excessive deformation while protecting a seal object member from damage in spite of the pressure fluctuation of hydrogen-containing gas. <P>SOLUTION: The gas seal structure comprises a seal member provided around a part through which the hydrogen-containing gas flows. The seal member comprises a seal body having a C-shaped part made of metal opened to the flow-through side of the gas, and a cover member made of resin to cover the outer peripheral side of the seal body. The C-shaped part has resilience and contacts the seal object member at least at two points opposed to each other, to energize the seal object member. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas seal structure applied to a joint portion of a vessel or piping that handles high-pressure natural gas, hydrogen, helium, or the like.

Conventionally, as a seal structure requiring airtightness, a structure in which a coil spring made of piano wire, Inconel, or the like is provided on the inner peripheral side of a metal outer peripheral portion (envelope) formed in a C-shaped cross section has been proposed. (See Non-Patent Document 1).
By Takahito Nishida, VALQUA, Vol. 29, No. 7, No. 3645

  By the way, in recent years, a fuel cell vehicle equipped with a fuel cell as a power source has been developed for practical use. In a fuel cell vehicle, it is necessary to mount a tank for storing a hydrogen-containing gas (including pure hydrogen) as a fuel gas, and a high degree of airtightness is required for the connecting portion between the hydrogen tank and the fuel cell.

However, when rubber or resin having elasticity is used as the material of the seal member, there is a problem in terms of hydrogen permeation resistance. From the viewpoint of hydrogen permeation resistance, it is preferable to use metal as the material of the sealing member, but since high airtightness is required as described above, the tightening force must be increased. On the other hand, as the material of the tank, a relatively soft material such as aluminum tends to be used from the viewpoint of weight reduction. If the tightening force is increased as described above, the tank is damaged and the life is shortened. There is a problem of end.
And in solving this problem, it is necessary to consider also the durability with respect to the pressure which acts on a sealing member. That is, when pressure fluctuation occurs due to the flow of hydrogen-containing gas or the like in the portion to be sealed, if the seal member is excessively deformed following this, the durability of the seal member is reduced. The usage period will be shortened.

  The present invention has been made to solve the above-described problems, and maintains a sealing function by suppressing excessive deformation while protecting a member to be sealed from damage regardless of pressure fluctuations of the hydrogen-containing gas. An object of the present invention is to provide a gas seal structure that can be used.

  The invention according to claim 1 is provided with a seal member provided around a portion through which the hydrogen-containing gas flows, and the seal member includes a metal C-shaped portion that opens to the gas flow side. A self-tightening seal body and a resin cover member covering the outer peripheral side of the seal body, and the C-shaped portion has an elastic force and contacts at least two points opposite to each other to be sealed And it biases with respect to this sealing object member, It is characterized by the above-mentioned.

  According to this invention, since the C-shaped part of the seal body is made of metal, it has high hydrogen permeation resistance. Since the C-shaped part is in contact with the member to be sealed at at least two points facing each other, the hydrogen-containing gas is blocked from flowing to the outside. Further, when the pressure of the circulating gas rises, the gas flows from the opening position of the C-shaped part, and the C-shaped part is deformed so as to contact the sealing target member. Thereby, even if the pressure of the gas increases, the sealing function of the seal body can be maintained.

  Further, when the gas pressure increases as described above, the sealing function is maintained by the deformation of the C-shaped portion, so that the tightening force when the seal body is mounted can be reduced. And it can prevent that the said sealing object member is damaged, and can prevent the lifetime reduction of the said sealing object member.

  In addition, by contacting the member to be sealed at the two points, the C-shaped portion can be expanded or contracted based on these contact points, so that the pressure variation of the circulating hydrogen-containing gas can be prevented. Thus, the direction in which the urging force acts does not fluctuate, and the positional deviation of the seal body can be prevented.

  Furthermore, by providing the cover member on the outer peripheral side of the seal body, the rigidity on the outer periphery side of the seal body can be increased. Therefore, when the pressure of the gas increases, the inner peripheral side of the seal body is deformed by the gas. The durability of the seal body can be improved by supporting the outer peripheral side of the seal body by the cover member and suppressing excessive deformation of the C-shaped portion while maintaining the sealing performance. Therefore, the lifetime of the seal body can be extended and the reliability can be further improved. Moreover, since the cover member is made of resin, it is possible to select a member having appropriate rigidity and elasticity so that unnecessary stress is not applied to the C-shaped portion and excessive deformation can be suppressed. . Furthermore, it can be easily attached to the seal body, and is excellent in assemblability. And the said seal body and the said cover member can be manufactured separately, and a production process can be simplified and cost can be reduced.

The invention according to a second aspect is the one according to the first aspect, wherein the cover member is made of urethane resin.
According to this invention, the rigidity and elasticity of the cover member can be made more suitable for the seal body, which can further contribute to improving the durability and extending the life of the seal body. .

The invention according to claim 3 is the one according to claim 1 or 2, wherein the cover member has a notch formed in a radial direction.
According to the present invention, when pressure is applied in the radial direction of the cover member, the pressure can be released by the notch, so that deformation of the cover member in the radius / circumferential direction can be suppressed.

According to a fourth aspect of the present invention, in any one of the first to third aspects, at least an outer surface of the seal body is lubricated.
According to this invention, since the lubricity of the seal body can be improved, even when a force is applied to the seal target member in contact with the seal target member, the seal body can be smoothly displaced. Can do. Therefore, the seal main body and the seal member target member can be prevented from being damaged from each other, and the lifetime of both can be increased.

The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the seal member is disposed at an inlet portion of a hydrogen tank connected to the fuel cell. Features.
According to the present invention, the hydrogen-containing gas stored in the hydrogen tank can be supplied to the fuel cell while ensuring high airtightness, so that the reliability as a fuel cell system is improved. Can do.

  According to the first aspect of the present invention, even if the pressure of the gas fluctuates, it is possible to maintain a sealing function of the seal body and ensure a high degree of airtightness. Moreover, it can prevent that the said sealing object member is damaged, and can prevent the lifetime reduction of the said sealing object member. In addition, it is possible to prevent the positional deviation of the seal main body, and to further improve the sealing performance. Furthermore, by providing the cover member on the outer peripheral side of the seal body, the life of the seal body can be extended and the reliability can be further improved. In addition, the production process can be simplified and the cost can be reduced.

According to the invention which concerns on Claim 2, it can contribute further to the durable improvement and lifetime improvement of the said seal main body.
According to the invention which concerns on Claim 3, the deformation | transformation to the radial / circumferential direction of the said cover member can be suppressed.
According to the invention which concerns on Claim 4, the said seal body and the said sealing member object member can be prevented from receiving damage mutually, and both lifetime can be improved.
According to the invention which concerns on Claim 5, the reliability as a fuel cell system can be improved.

A gas seal structure according to an embodiment of the present invention will be described with reference to the drawings. Below, the case where the fuel cell vehicle carrying a fuel cell as a motive power source is applied as a fuel cell system is demonstrated.
FIG. 1 is a configuration diagram of a main part of a fuel cell system to which a gas seal structure according to an embodiment of the present invention is applied. As shown in FIG. 1, the fuel cell system 1 includes a fuel cell 2 that generates electricity by electrochemical reaction of hydrogen and oxygen, and a hydrogen tank 3 that stores hydrogen. The hydrogen tank 3 and the fuel cell 2 are connected via a hydrogen supply path 5.

  As the hydrogen tank 3, a structure in which a carbon fiber is wound around an aluminum liner body formed in a bottomed cylindrical shape is preferably used from the viewpoint of weight reduction and the like. The inlet 4 of the hydrogen tank 3 is reduced in diameter as compared with the main body portion. A mounting portion 6 connected to the hydrogen supply path 5 is mounted at the inlet 4 of the hydrogen tank 3.

  FIG. 2 is an explanatory view showing a seal structure of a hydrogen tank of the fuel cell system shown in FIG. As shown in the figure, a fitting recess 8 having a slightly enlarged diameter is formed in a portion near the inlet 4 in the tank inner peripheral portion 7 of the hydrogen tank 3. The fitting portion 6 is attached to the hydrogen tank 3 by inserting and fitting the protruding tip portion 6 a of the fitting portion 6 into the fitting recess 8. As a result, the hydrogen tank 3 is connected to the fuel cell 2 via the hydrogen supply path 5.

  In addition, a housing groove 9 for expanding the fitting recess 8 and a housing groove 10 located on the outer periphery thereof are formed on the front end surface of the hydrogen tank 3. A main seal member 11 and an auxiliary seal member 12 are disposed in the housing grooves 9 and 10, respectively.

FIG. 3 is a state explanatory view showing a state of the seal member in the first embodiment at the time of normal pressure (FIG. 3A) and at the time of pressurization (FIG. 3B).
As shown in the figure, the main seal member 11 has an opening 13 so as to open to the gas flow side (in this case, the inner peripheral side) and has a substantially C-shaped cross section (in this case). A metal seal body 15 formed in an O-ring (with an opening 13 formed therein), and a resin cover member 14 attached so as to be in close contact with the outer peripheral surface of the seal body 15. ing. Further, the seal body 15 has an elastic force and comes into contact with the mounting portion 6 and the hydrogen tank 3 which are members to be sealed at two points facing each other (in this case, the upper end portion and the lower end portion of the seal body 15). 3 and 6 are configured to be biased.
On the other hand, the auxiliary seal member 12 is made of resin and has a substantially circular cross section. In the present embodiment, the auxiliary seal member 12 is also configured to come into contact with the mounting portion 6 and the hydrogen tank 3 which are members to be sealed. The material of the auxiliary seal member 12 is not limited to resin, and may be rubber or metal, for example. Further, the shape of the auxiliary seal member 12 may be, for example, an O-ring shape or a C-ring shape.

  FIG. 3 is a state explanatory view showing a state of the seal member in the first embodiment at the time of normal pressure (FIG. 3A) and at the time of pressurization (FIG. 3B). As shown in FIG. 3A, the main seal member 11 is tightened with a tightening force sufficient to contact the seal target members 3 and 6 at two points facing each other with the mounting portion 6 mounted on the hydrogen tank 3. It has been processed and is accommodated in the accommodating groove 9. Similarly, the auxiliary seal member 12 is accommodated in the accommodating groove 10.

  Since the seal body 15 is made of metal, it has high hydrogen permeation resistance. And as shown to Fig.3 (a), since the said seal | sticker main body 15 is contacting the sealing object members 3 and 6 at two points | pieces which mutually oppose, the distribution | circulation to the exterior of the said hydrogen containing gas is interrupted | blocked. .

  Further, when the pressure of the flowing gas (hydrogen gas) increases, the gas flows in from the opening 13 of the seal body 15, and as shown in FIG. The outer peripheral side of the seal body 15 is deformed so as to come into contact. Thereby, even if the pressure of the gas increases, the sealing function of the seal body 15 can be maintained.

  Further, as described above, since the tightening force when the seal body 15 is mounted can be reduced, it is possible to prevent the seal target members 3 and 6 from being damaged, and to prevent a decrease in life. it can.

  In addition, when the seal main body 15 comes into contact with the sealing target members 3 and 6 at the two points, the seal main body 15 can be expanded or contracted based on these contact points. For this reason, the direction in which the urging force acts on the pressure fluctuation of the flowing hydrogen-containing gas (in this case, substantially the same direction as the axial direction of the hydrogen tank 3) does not fluctuate, and the displacement of the seal body 15 is prevented. be able to. Furthermore, the sealing performance can be further improved by providing the auxiliary seal member 12.

  Furthermore, by providing the cover member 14 on the outer peripheral side of the seal main body 15, the rigidity on the outer peripheral side of the seal main body 15 can be increased. Therefore, when the hydrogen-containing gas rises in pressure, such as when the hydrogen tank 3 is filled with the hydrogen-containing gas, the inner peripheral side of the seal body 15 is deformed by the hydrogen-containing gas to maintain the sealing performance, and the cover member By supporting the outer peripheral side of the seal body 15 by 14, excessive deformation of the C-shaped portion in the seal body 15 can be suppressed. Thereby, the durability of the seal body 15 can be enhanced. Therefore, the life of the seal body 15 can be extended and the reliability can be further improved.

  Moreover, since the cover member 14 is made of resin, it is possible to select a member having appropriate rigidity and elasticity so that unnecessary stress is not applied to the C-shaped portion and excessive deformation can be suppressed. (The urethane resin is particularly preferable as the resin). Furthermore, it can be easily attached to the seal main body 15 and is excellent in assemblability. And since the said seal main body 15 and the said cover member 14 can be manufactured separately, a preparation process can be simplified and cost can be reduced. That is, the main seal member 11 of the present embodiment is produced by individually manufacturing the seal body 15 having a substantially C-shaped cross section and the cover member 14 having a U-shaped cross section with the inner peripheral side recessed. It is easy to create each mold material, and it is not necessary to prepare a special mold material, so that the cost can be reduced. Since the main seal member 11 can be created by mounting the cover member 14 on the outer peripheral side of the seal body 15, it is not necessary to perform a special joining process or the like, and the creation process can be simplified.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a state explanatory view showing states of the seal member in the second embodiment at normal pressure (FIG. 4A) and at pressurization (FIG. 4B). The seal main body 25 shown in the figure is different from the above-described embodiment in that the cross section is formed in a substantially C shape with an opening further than the seal main body 15. If it does in this way, at the time of pressurization, a deformation | transformation of the seal body 25 can be permitted so that the site | part which contacts the said sealing object members 3 and 6 may spread more.

  Here, the surface of the seal body 25 is preferably subjected to a lubrication treatment such as silver plating. In this way, since the lubricity of the seal body 25 can be improved, a force that slides against the sealing target members 3 and 6 in contact with the seal body 25 (in this case, orthogonal to the axial direction of the tank 3). Even when such a force is applied, it can be displaced smoothly. Therefore, the seal body 25 and the seal member target members 3 and 6 can be prevented from being damaged from each other, and the lifetime of both can be increased.

  In addition, by providing the cover member 24 on the outer peripheral side of the seal body 25, excessive deformation such that the distance between the openings 23, 23 of the seal body 25 increases excessively as in the first embodiment. Can be suppressed.

  Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a state explanatory view showing a state of the seal member in the third embodiment at normal pressure (FIG. 5A) and at the time of pressurization (FIG. 5B). FIG. 6 is a perspective view of the cover member shown in FIG. The main seal member 31 shown in these drawings has a notch 33 formed in the radial direction of the cover member 32, which is different from the above-described embodiment.

  In this way, when pressure is applied in the radial direction of the cover member 32 (in the direction of arrow A in FIG. 5), the pressure can be released by the notch 33, so the radius / circumferential direction of the cover member 32 Can be prevented from being deformed.

  The contents of the present invention are not limited to the above-described embodiments. For example, although the case where pure hydrogen is used as the hydrogen-containing gas has been described, a hydrogen reformed gas or the like may be used. Further, as described in the above embodiment, when the main seal member and the auxiliary seal member are disposed at the inlet of the hydrogen tank connected to the fuel cell, the hydrogen-containing gas stored in the hydrogen tank is Since it can supply to the said fuel cell in the state which ensured high airtightness, the reliability as a fuel cell system can be improved. However, the application target of the present invention is not limited to this, and may be a joint seal structure, for example. Moreover, as a shape of the main seal member, it is only necessary to have a C-shaped part. That is, the cross section may be O-shaped as in the first embodiment. Moreover, you may combine each embodiment suitably. For example, a notch may be formed in the cover member shown in the first embodiment.

It is a principal part block diagram of the fuel cell system to which the gas seal structure in the 1st to 3rd embodiment of this invention is applied. It is explanatory drawing which shows the seal structure of the hydrogen tank of the fuel cell system shown in FIG. It is a state explanatory drawing which shows the state at the time of normal pressure (the figure (a)) and pressurization (the figure (b)) of the sealing member in 1st Embodiment. It is state explanatory drawing which shows the state at the time of the normal pressure (the figure (a)) and pressurization (the figure (b)) of the sealing member in 2nd Embodiment. It is state explanatory drawing which shows the state at the time of the normal pressure (the figure (a)) and pressurization (the figure (b)) of the sealing member in 3rd Embodiment. It is a perspective view of the cover member shown in FIG.

Explanation of symbols

2 ... Fuel cell 3 ... Hydrogen tank (member to be sealed)
4 ... Tank inlet 5 ... Hydrogen supply path 6 ... Mounting portion (member to be sealed)
11, 21, 31 ... main seal member (seal member)
14, 24, 32 ... Cover members 15, 25, 35 ... Seal body

Claims (5)

Comprising a seal member provided around the site through which the hydrogen-containing gas flows;
The seal member is a self-tightening seal body having a metal C-shaped portion that opens to the gas flow side;
A resin cover member covering the outer peripheral side of the seal body,
The gas seal structure characterized in that the C-shaped portion has an elastic force, contacts the member to be sealed at at least two points facing each other, and urges the member to be sealed.   The gas seal structure according to claim 1, wherein the cover member is made of urethane resin.   The gas seal structure according to claim 1, wherein the cover member is formed with a notch in a radial direction.   The gas seal structure according to any one of claims 1 to 3, wherein at least an outer surface of the seal body is lubricated. The gas seal structure according to any one of claims 1 to 4, wherein the seal member is disposed at an inlet portion of a hydrogen tank connected to a fuel cell.

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