JP2022066850A - gasket - Google Patents

Abstract

To provide a gasket which enables improvement of durability.SOLUTION: A gasket includes: a separator 200; and gasket bodies 210, 220 which are adhered to the separator 200 by an adhesive so as to surround a sealing object area and integrally provided with the separator 200 by integral molding. The separator 200 is formed with a groove 203 which surrounds the sealing object area. The gasket bodies 210, 220 are provided at the separator 200 in a state that the gasket bodies 210, 220 are arranged along the groove 203 and a part on the separator 200 side is embedded in the groove 203.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gasket such as a gasket integrated with a separator.

In the gasket integrated with a separator provided in a fuel cell, a gasket body made of an elastic body such as rubber is integrally molded with an adhesive applied to a separator made of a metal or carbon material. In the separator-integrated gasket thus obtained, the adhesive deteriorates due to the influence of acids such as hydrofluoric acid and sulfuric acid mixed in the wastewater due to power generation, and the gasket body is peeled off over time, resulting in sealing performance. Is known to decrease. As a countermeasure, a technique of coating the surface of an adhesive with a corrosion-resistant material is known (see Patent Document 1). However, in this technique, a corrosion-resistant material is required, and a step of coating the corrosion-resistant material must be added in the manufacturing process, which increases the cost. In addition, a technique is also known in which the deterioration of the adhesive is prevented from spreading by not applying the adhesive to a part of the contact portion between the separator and the gasket body instead of applying the adhesive to the entire contact portion. (See Patent Document 2). According to this technique, although the life is extended, there is still room for improvement because hydrofluoric acid and the like gradually invade into the portion to which the adhesive is not applied and the entire adhesive is deteriorated. It should be noted that not only the gasket integrated with the separator but also the metal gasket and the like have the same problem.

Japanese Unexamined Patent Publication No. 2007-59256 Japanese Unexamined Patent Publication No. 2011-54399

An object of the present invention is to provide a gasket capable of increasing durability.

The present invention employs the following means to solve the above problems.

The gasket of the present invention is
A gasket comprising a substrate and a gasket body made of an elastic body that is adhered to the substrate with an adhesive and integrally provided by integral molding so as to surround the area to be sealed.
The substrate is formed with a groove surrounding the area to be sealed.
The gasket main body is characterized in that it is provided on the substrate along the groove and in a state where a part of the substrate side is embedded in the groove.

According to the present invention, since the gasket body is partially embedded in the groove formed in the substrate, hydrofluoric acid or the like penetrates to the position of the adhesive provided between the gasket body and the substrate. Can be suppressed. This makes it possible to prevent the adhesive from deteriorating over time.

The groove may have a substantially rectangular cross-sectional shape perpendicular to the direction in which the groove extends.

As a result, when the gasket body is compressed, the stress acting on the gasket body is concentrated near the boundary portion between the groove upper end portion and the groove side surface of the contact portion between the gasket body and the substrate. As a result, the surface pressure of the gasket body with respect to the substrate increases near both sides in the width direction of the gasket body, so that it is possible to effectively suppress the invasion of hydrofluoric acid and the like to the position of the adhesive.

It is preferable that the gasket body is provided with at least one protrusion that tapers as the distance from the substrate increases along the groove.

It is preferable that the protrusions are composed of a pair of protrusions extending in parallel.

The substrate may be a separator constituting the fuel cell.

In addition, each of the above configurations can be adopted in combination as much as possible.

As described above, according to the present invention, durability can be improved.

FIG. 1 is a cross-sectional view showing a part of the fuel cell according to the first embodiment of the present invention. FIG. 2 is a plan view of the gasket according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating the performance of the gasket according to the first embodiment of the present invention. FIG. 4 is a diagram illustrating the performance of the gasket according to Comparative Example 1. FIG. 5 is a diagram illustrating the performance of the gasket according to the second embodiment of the present invention. FIG. 6 is a diagram illustrating the performance of the gasket according to Comparative Example 2.

Hereinafter, embodiments for carrying out the present invention will be described in detail exemplary with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention to those alone unless otherwise specified. .. In the following examples, the case where the gasket is a gasket with an integrated separator will be described as an example.

(Example 1)
The gasket according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is a cross-sectional view showing a part of the fuel cell according to the first embodiment of the present invention, and is a cross-sectional view schematically showing a part of the fuel cell. FIG. 2 is a plan view of the gasket according to the first embodiment of the present invention. Of the cross-sectional views in FIG. 1, the cross-sectional view of the separator integrated gasket corresponds to the AA cross-sectional view in FIG. FIG. 3 is a diagram for explaining the performance of the gasket according to the first embodiment of the present invention, and FIG. 4 is a diagram for explaining the performance of the gasket according to the comparative example 1.

<Fuel cell>
A fuel cell provided with a separator integrated gasket according to the present embodiment will be described with reference to FIGS. 1 and 2. Generally, a fuel cell is configured as a cell stack consisting of a plurality of single cells. FIG. 1 shows a cross-sectional view of a part of a cell stack composed of a plurality of single cells. As shown in FIG. 1, the cell stack is configured such that a MEA (Membrane Electrode Assembly) 100 and a separator 200 as a substrate are alternately laminated. Then, the single cell 10 is composed of the MEA 100 and the pair of separators 200 provided on both sides thereof.

The MEA 100 includes an electrolyte membrane and a pair of gas diffusion layers provided on both sides of the electrolyte membrane. Further, the separator 200 is formed with a flow path 201 through which a fuel gas, an oxidant gas, a coolant, and the like flow.

And, in order to prevent fuel gas, oxidant gas, coolant and the like from leaking between the MEA 100 and the separator 200, gasket bodies 210 and 220 made of an elastic body such as rubber are provided. In this embodiment, the separator 200 is integrally provided with the gasket bodies 210 and 220. A member in which the gasket bodies 210 and 220 are integrally provided on the separator 200 in this way is called a "separator integrated gasket". A gasket integrated with a separator can be obtained by molding the gasket bodies 210 and 220 by insert molding using the separator 200 as an insert component in a state where the adhesive is applied to the region of the separator 200 where the gasket bodies 210 and 220 are provided.

<Separator integrated gasket>
The separator integrated gasket provided in the fuel cell will be described in more detail. The separator 200 is made of a metal or carbon material. The separator 200 is provided with a flow path 201 formed on the surface of the separator 200 and a plurality of manifolds 202. The manifold 202 is provided to distribute the fuel gas, the oxidant gas, the coolant, and the like to each cell.

Then, in order to prevent the above fuel gas and the like from leaking to the outside, the gasket bodies 210 and 220 are attached to the separator 200 around the region where the flow path 201 is formed and around the manifold 202, respectively. It is provided integrally. That is, the gasket bodies 210 and 220 are adhered to and integrated with the separator 200 so as to surround the area to be sealed (the area where the flow path 201 is formed and the area where the manifold 202 is provided). It is integrally provided by molding. In FIG. 2, the portion where the gasket main body 210 is provided is shown by a thick line. As the material of the gasket bodies 210 and 220, rubber materials such as VMQ, EPDM, and FKM can be preferably used.

The separator 200 is formed with a groove 203 surrounding the sealing target area, and the gasket bodies 210 and 220 are formed along the groove 203 with a part of the separator 200 side embedded in the groove 203. It is provided on the separator 200. The width of the gasket bodies 210 and 220 needs to be set to be equal to or larger than the width of the groove 203 so that a part of the gasket bodies 210 and 220 is embedded in the entire inside of the groove 203. Here, the groove 203 is configured so that the shape of the cross section perpendicular to the direction in which the groove 203 extends is substantially rectangular. That is, the groove 203 is configured to include a pair of a flat groove bottom surface and a groove side surface perpendicular to the groove bottom surface. The bottom surface of the groove and the side surface of the groove can be connected by a so-called C surface or R surface. Further, the gasket main body 210 according to the present embodiment is provided with a protrusion 211 that tapers as the distance from the separator 200 increases along the groove 203.

<Excellent points of the gasket according to this embodiment>
According to the gasket (separator integrated gasket) according to the present embodiment, the gasket bodies 210 and 220 are partially embedded in the groove 203 formed in the separator 200 on the separator 200 side. Therefore, it is possible to prevent hydrofluoric acid, sulfuric acid, and the like mixed in the wastewater due to the power generation of the fuel cell from invading to the position of the adhesive provided between the gasket bodies 210 and 220 and the separator 200. This makes it possible to prevent the adhesive from deteriorating over time. Therefore, it is possible to prevent the gasket bodies 210 and 220 from peeling off from the separator 200 for a long period of time.

Further, in the present embodiment, the groove 203 effectively suppresses the invasion of hydrofluoric acid or the like to the position of the adhesive by having a substantially rectangular cross-sectional shape perpendicular to the direction in which the groove 203 extends. Can be done. This point will be described in detail with reference to FIGS. 3 and 4.

FIG. 3A shows a cross-sectional view of the gasket integrated gasket according to the present embodiment in the vicinity of the gasket main body 210 in a state where no external force is applied. FIG. (B) shows a cross-sectional view of the separator integrated gasket according to the present embodiment in the vicinity of the gasket main body 210 in a state of being incorporated in the fuel cell. FIG. 3C shows the surface pressure distribution of the gasket main body 210 with respect to the separator 200.

FIG. 4A shows a cross-sectional view of the separator integrated gasket according to Comparative Example 1 in the vicinity of the gasket main body 210X in a state where no external force is applied. FIG. (B) shows a cross-sectional view of the separator integrated gasket according to Comparative Example 1 in the vicinity of the gasket main body 210X in a state of being incorporated in the fuel cell. FIG. 3C shows the surface pressure distribution of the gasket body 210X with respect to the separator 200X.

In Comparative Example 1, the separator 200X is not provided with a groove, and the gasket body 210X is provided on the plane of the separator 200X. The gasket main body 210 according to the present embodiment and the gasket main body 210X according to Comparative Example 1 have the same width W and the same height H0 from the surface of the separators 200 and 200X in a state where no external force is applied. Further, the shapes of the portions exposed from the surfaces of the separators 200 and 200X are also the same, and the materials and the manufacturing method of the separator integrated gasket are also the same. Further, the height H1 from the surface of the separators 200 and 200X of the gasket bodies 210 and 210X when the gasket integrated with the separator is incorporated in the fuel cell is also the same.

In the case of the separator integrated gasket according to the present embodiment, the surface pressure of the gasket body 210 with respect to the separator 200 is higher on both sides of the gasket body 210 in the width direction than on the peak surface pressure on the back side of the protrusion 211. It can be seen that it is about twice as large (see FIG. 3 (c)). This acts on the gasket main body 210 in the vicinity of the boundary portion between the groove upper end portion and the groove side surface of the groove 203 in the contact portion between the gasket main body 210 and the separator 200 when the gasket main body 210 is compressed. This is because the stress is concentrated. As described above, since the surface pressure of the gasket main body 210 with respect to the separator 200 becomes high near both sides in the width direction of the gasket main body 210, it is possible to effectively suppress the invasion of hydrofluoric acid and the like to the position of the adhesive. can. Although the gasket main body 210 has been described in FIG. 3, it goes without saying that the same applies to the gasket main body 220.

On the other hand, in the case of the gasket with a separator integrated according to Comparative Example 1, the surface pressure of the gasket main body 210X with respect to the separator 200X is highest on the directly back side of the protrusion and gradually decreases toward both sides in the width direction. Therefore, it can be seen that hydrofluoric acid and the like easily invade the position of the adhesive.

(Example 2)
FIG. 5 shows Example 2 of the present invention. In this embodiment, the configuration when the configuration of the gasket main body is different from that of the first embodiment will be shown. Since other configurations and operations are the same as those in the first embodiment, the same components are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 5 is a diagram for explaining the performance of the gasket according to the second embodiment of the present invention, and FIG. 6 is a diagram for explaining the performance of the gasket according to the comparative example 2.

Since the configuration other than the configuration of the fuel cell and the configuration relating to the shape of the gasket body in the gasket integrated with the separator is the same as that of the first embodiment, the description thereof will be omitted.

The separator-integrated gasket according to the present embodiment is different from the first embodiment in that the protrusions of the gasket main body 210A are composed of a pair of protrusions 211A extending in parallel. That is, the gasket main body 210A according to the present embodiment is provided with a pair of protrusions 211A that taper as the distance from the separator 200 increases, along the groove 203. A groove 212A is provided between the pair of protrusions 211 so as to follow the groove 203.

Also in the gasket (separator integrated gasket) according to the present embodiment configured as described above, the gasket main body 210A is partially embedded in the groove 203 formed in the separator 200 on the separator 200 side. Therefore, it is possible to prevent acids such as hydrofluoric acid and sulfuric acid mixed in the wastewater due to the power generation of the fuel cell from invading to the position of the adhesive provided between the gasket main body 210A and the separator 200. Therefore, the same effect as that of the first embodiment can be obtained.

Further, also in this embodiment, the groove 203 effectively suppresses the invasion of hydrofluoric acid or the like to the position of the adhesive by having a substantially rectangular cross-sectional shape perpendicular to the direction in which the groove 203 extends. Can be done. This point will be described in detail with reference to FIGS. 5 and 6.

FIG. 5A shows a cross-sectional view of the separator integrated gasket according to the present embodiment in the vicinity of the gasket main body 210A in a state where no external force is applied. FIG. (B) shows a cross-sectional view of the separator integrated gasket according to the present embodiment in the vicinity of the gasket main body 210A in a state of being incorporated in the fuel cell. FIG. 3C shows the surface pressure distribution of the gasket body 210A with respect to the separator 200.

FIG. 6A shows a cross-sectional view of the separator integrated gasket according to Comparative Example 2 in the vicinity of the gasket main body 210Y in a state where no external force is applied. FIG. 2B shows a cross-sectional view of the separator integrated gasket according to Comparative Example 2 in the vicinity of the gasket main body 210Y in a state of being incorporated in the fuel cell. FIG. 3C shows the surface pressure distribution of the gasket body 210Y with respect to the separator 200Y.

In Comparative Example 2, the separator 200Y is not provided with a groove, and the gasket body 210Y is provided on the plane of the separator 200Y. The gasket main body 210A according to the present embodiment and the gasket main body 210Y according to Comparative Example 2 have the same width W and the same height H0 from the surface of the separators 200 and 200Y in a state where no external force is applied. Further, the shapes of the portions exposed from the surfaces of the separators 200 and 200Y are also the same, and the materials and the manufacturing method of the separator integrated gasket are also the same. Further, the height H1 from the surface of the separators 200 and 200Y of the gasket bodies 210A and 210Y when the gasket integrated with the separator is incorporated in the fuel cell is also the same.

In the case of the separator integrated gasket according to this embodiment, the surface pressure of the gasket body 210A with respect to the separator 200 is the peak surface pressure on both sides in the width direction of the gasket body 210A rather than the peak surface pressure on the back side near the pair of protrusions 211A. It can be seen that is about twice as large (see FIG. 5 (c)). The reason is as described in Example 1. Therefore, the same effect as that of the first embodiment can be obtained. In the case of this embodiment, by adopting the configuration having the pair of protrusions 211A, the peak surface pressure on the back side in the vicinity of the pair of protrusions 211A is 1.5 as compared with the case of the first embodiment. It was found that the peak surface pressure on both sides of the gasket body 210A in the width direction can be increased by about 1.5 times as compared with the case of Example 1.

On the other hand, in the case of the separator integrated gasket according to Comparative Example 2, the surface pressure of the gasket main body 210Y with respect to the separator 200Y is the highest on the directly back side of the pair of protrusions, as in the case of Comparative Example 1, and is in the width direction. It gradually decreases toward both sides. Therefore, it can be seen that hydrofluoric acid and the like easily invade the position of the adhesive.

(others)
In the above embodiment, the case where the gasket body is provided with one protrusion and the case where the protrusion is two are shown, but in the present invention, the number of protrusions is not limited, and three or more protrusions can be provided. Further, in the above embodiment, the case where the gasket is a separator integrated gasket provided in the fuel cell is shown. However, in the present invention, it can also be applied to gaskets used for other uses. For example, it can be applied to a general metal gasket. In this case, the substrate is a metal plate, and the gasket body is an elastic gasket body integrally provided on the substrate by integral molding.

10 single cell 100 MEA
200 Separator 201 Flow path 202 Manifold 203 Groove 210, 210A, 220 Gasket body 211,211A Protrusion 212A Groove

Claims (5)

A gasket comprising a substrate and a gasket body made of an elastic body that is adhered to the substrate with an adhesive and integrally provided by integral molding so as to surround the area to be sealed.
The substrate is formed with a groove surrounding the area to be sealed.
The gasket body is provided on the substrate along the groove and with a part of the substrate side embedded in the groove. The gasket according to claim 1, wherein the groove has a substantially rectangular shape in a cross section perpendicular to the direction in which the groove extends. The gasket according to claim 1 or 2, wherein the gasket body is provided with at least one protrusion that tapers as the distance from the substrate increases along the groove. The gasket according to claim 3, wherein the protrusions are composed of a pair of protrusions extending in parallel. The gasket according to claim 1, 2, 3 or 4, wherein the substrate is a separator constituting a fuel cell.

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