JP6619646B2 - Gasket for fuel cell and manufacturing method thereof - Google Patents

Description

  The present invention relates to a fuel cell gasket having a reinforcing frame integrally and a method for manufacturing the same.

  In a fuel cell, basically, a power generator including MEA (membrane-electrode composite) provided with a pair of electrode layers on both surfaces of an electrolyte membrane is sandwiched between separators to form a fuel cell. It has a stack structure in which many are stacked. Then, an oxidizing gas (oxygen) is supplied to one catalytic electrode layer (cathode) from an oxidizing gas flow path formed on one side of each separator, and a fuel gas flow formed on the other side of each separator. Electric power is generated by an electrochemical reaction that is supplied from the channel to the other catalyst electrode layer (anode) and is a reverse reaction of water electrolysis, that is, a reaction that generates water from hydrogen and oxygen.

  The fuel cell stack has a cathode gas (oxidizing gas) layer, an anode gas (fuel gas) layer, and a refrigerant layer in one cell, and the fuel cell stack has, for example, 400 to 500 cells stacked one by one. Some have more than 1000 fluid layers. These fluid layers need to be sealed so that the fluid flowing through the layers does not leak. As a sealing means, it is known to provide a sealing means along the outer periphery of the reaction surface of the power generation body, and further to provide a sealing means so as to surround a manifold hole for supplying and discharging fluid as required. . As such a sealing means, a gasket made of a rubber-like elastic body such as rubber or thermoplastic elastomer, or a rigid adhesive is used.

  In the case of a gasket made of a rubber-like elastic body, it is preferable to integrally form a laminated member such as a separator constituting the fuel cell. The reason is that labor can be saved when the fuel cell stack is assembled. However, depending on the structure of the fuel cell stack, a gasket made of a single rubber is used as a sealing means between the units that are subassembled to some extent or between the unit and the outermost member (eg, current collector plate). Sometimes. This single rubber gasket seals an area as large as a fuel cell separator for automobiles, and since it has low rigidity, it is likely to be twisted when assembled into a seal groove, so that workability is poor and mechanization is difficult. It must be done manually, and as a result, a huge amount of work is required.

  Therefore, the handling property at the time of assembling has been improved by integrally molding a gasket made of a rubber-like elastic body into a reinforcing frame (frame body) formed by punching a thin sheet of synthetic resin or metal. (For example, see the following Patent Document 1).

Japanese Patent No. 5468457

  However, according to the conventional gasket for a fuel cell, the connecting portion connecting the seal portion and the frame is made of a rubber-like elastic body whose thickness is smaller than the thickness of the frame. Concerns remain in handling at the time of assembly.

Set only with the time of the handling of the fuel cell gasket provides child and which was further improved.

In fuel gasket for a fuel battery to be interposed between the cells components of the battery, the cell with the synthetic resin frame shape surrounding the seal region of interest between components, a rubber-like elastic body that is integrally joined to the frame A gasket main body, and the gasket main body is joined to an end portion of the frame on the seal target region side so as to cover both sides in the thickness direction of the end portion; A connecting part that extends to the sealing target area side and is joined to a surface of the frame facing the sealing target area side and is thicker than the frame, and extends from the connecting part to the sealing target area side to the cell part. And a thin portion at a portion of the frame where the covering portion of the gasket body is joined.

Gasket body, the seal covering portion in the thickness direction both sides of the end portion is formed so as to cover the end portion of the target region side and the connecting portion formed thicker than the frame extends from the covering portion of the frame Therefore, the rigidity of the joint portion with the frame is large, and therefore, the seal portion is not easily twisted or tilted during assembly, and handling properties can be further improved.

It is a partial sectional view showing a first embodiment of the fuel cell gaskets alone. The first embodiment of the fuel cell gaskets is a partial sectional view showing in a mounted state of the fuel cell a plurality of layers. The first embodiment of the fuel cell gaskets is a partial cross-sectional perspective view showing a state of arranging on one of the separators. It is a partial sectional view showing a second embodiment of the fuel cell gaskets alone. The second embodiment of the fuel cell gaskets is a partial sectional view showing in a mounted state of the fuel cell a plurality of layers. The second embodiment of the fuel cell gaskets is a partial cross-sectional perspective view showing a state of arranging on one of the separators. It is a partial cross-sectional view illustrating a third embodiment of the fuel cell gaskets alone. The third embodiment of the fuel cell gaskets is a partial sectional view showing in a mounted state of the fuel cell a plurality of layers. The third embodiment of the fuel cell gaskets is a partial cross-sectional perspective view showing a state of arranging on one of the separators. It is a partial sectional view showing a fourth embodiment of the fuel cell gaskets alone. The fourth embodiment of the fuel cell gaskets is a partial sectional view showing in a mounted state of the fuel cell a plurality of layers. The fourth embodiment of the fuel cell gaskets is a partial cross-sectional perspective view showing a state of arranging on one of the separators. It is a partial cross-sectional view illustrating a fifth embodiment of the fuel cell gaskets alone. The fifth embodiment of the fuel cell gaskets is a partial sectional view showing in a mounted state of the fuel cell a plurality of layers. The fifth embodiment of the fuel cell gaskets is a partial cross-sectional perspective view showing a state of arranging on one of the separators.

For implementation in the form of a fuel cell gasket it will be described with reference to the drawings.

First, FIG. 1 to FIG. 3 shows a first embodiment of a fuel cell gaskets. The fuel cell gasket 10 is assembled to a fuel cell as shown in FIG. 2. In FIG. 2, reference numeral 20 denotes an electrolyte membrane and catalyst electrode layers (anode and cathode) provided on both sides thereof. It is a power generation body which consists of a gas-diffusion layer laminated | stacked on the both sides of the thickness direction. Then, separators 30 and 40 each formed of a metal plate are laminated on both sides in the thickness direction of power generation body 20 to constitute fuel cell 1, and a large number of fuel cells 1 are interposed via fuel cell gasket 10. The fuel cell stack is configured by being stacked. Incidentally, the separator 30 and 40 correspond to cell Le component.

  Between the power generation body 20 and the separator 30 on one side thereof, for example, a fuel gas flow path A is defined by a flow path groove 31 formed in the separator 30, and the power generation body 20 and the separator 40 on the other side are defined. In the meantime, for example, an oxidant gas flow path B is defined by a flow path groove 41 bent in the separator 40. The fuel gas flow path A and the oxidant gas flow path B are sealed by an elastic sheet 50 provided integrally around the power generation body 20. That is, in this fuel cell, in each fuel cell 1, the fuel gas flowing through the fuel gas flow path A is supplied to the anode side of the power generator 20, and the oxidant gas flowing through the oxidant gas flow path B is It is supplied to the cathode side of the body 20 and generates electric power by a reaction that generates water from hydrogen and oxygen.

  Further, between the separators 30 and 40, a refrigerant flow path C is formed for circulating a refrigerant liquid for removing reaction heat generated by power generation. The fuel cell gasket 10 includes the refrigerant flow path. C is sealed. As shown in FIGS. 1 and 3, the fuel cell gasket 10 includes a synthetic resin frame 11 and a rubber-like elastic gasket main body 12 provided integrally with the frame 11.

  Specifically, the frame 11 in the fuel cell gasket 10 is made of a synthetic resin having rigidity higher than that of the rubber-like elastic body forming the gasket body 12, and is sealed between the separators 30 and 40 shown in FIG. 2 by injection molding. In other words, it is formed in a shape surrounding the refrigerant flow path C, which is the target area, in other words, between the gasket receiving grooves 32 and 42 formed in the separators 30 and 40 so as to surround the formation areas of the flow path grooves 31 and 41. It is manufactured in a shape that can be placed in the fitted state.

  Further, the gasket body 12 in the fuel cell gasket 10 is formed integrally with the frame 11 by a molding rubber material such as liquid rubber, and has a thickness at the end of the frame 11 on the refrigerant flow path C side. The covering portions 121 and 122 joined so as to cover the directional both sides 11a and 11b, and the surface 11c of the frame 11 facing the refrigerant flow path C side while extending from the covering portions 121 and 122 to the refrigerant flow passage C side. And a seal portion 124 extending from the connection portion 123 to the refrigerant flow path C side.

  The surface of the connecting portion 123 in the gasket body 12 is flush with the surfaces of the covering portions 121 and 122, and thus the connecting portion 123 is thicker than the frame 11. Further, the seal portion 124 in the gasket body 12 includes a plate-like base portion 124c having substantially the same thickness as the connecting portion 123, and a pair of seal beads 124a and 124b formed to protrude from the base portion 124c to both sides in the thickness direction. Become. Accordingly, the seal portion 124 as a whole is thicker than the connecting portion 123 and consequently thicker than the frame 11, and in the assembled state shown in FIG. 2, the seal beads 124 a and 124 b are inserted into the gasket receiving grooves 32 of the separators 30 and 40. , 42 are in close contact with each other in an appropriate compression state.

  According to the fuel cell gasket 10 of the first embodiment having the above configuration, the gasket main body 12 made of a rubber-like elastic body is reinforced by the frame 11 made of a synthetic resin. It is possible to ensure good handling when assembling between 1 (separator 30, 40).

  In particular, the gasket main body 12 includes the covering portions 121 and 122 formed so as to cover both sides in the thickness direction of the end portion on the refrigerant flow path C side of the frame 11, and the frame 11 continuously with the covering portions 121 and 122. Since it is joined to the frame 11 by the connecting portion 123 formed to be thicker, the rigidity between the frame 11 and the seal portion 124 is large, so that the seal portion 124 is less likely to twist or fall during assembly, Handling property at the time of assembly can be further improved. As a result, the reliability of the seal is also improved.

  In addition, when the frame 11 is manufactured by punching a sheet made of synthetic resin or metal as in the prior art, most of the sheet is wasted and only the specification with a uniform thickness can be obtained. According to the fuel cell gasket 10 configured as described above, since the frame 11 is manufactured by injection molding of synthetic resin, there is little material that is wasted in the manufacturing process, and thus the yield of the material can be improved. The degree of freedom in design can be improved, for example, by making the specifications of the frame 11 partially different.

  Further, the seal portion 124 in the gasket body 12 is made of only a rubber-like elastic body, that is, the frame 11 does not exist between the seal beads 124a and 124b, so that the compression amount of the seal portion 124 (seal beads 124a and 124b) is increased. Sufficient sealing surface pressure and seal width can be secured.

4 to 6, as an example of the different specifications the thickness of the frame 11 partially shows a second embodiment of the fuel cell gaskets.

  In the fuel cell gasket 10 of this embodiment, a thin portion 111 is formed in a portion of the frame 11 where the covering portions 121 and 122 of the gasket body 12 are joined (end portion on the refrigerant flow path C side). Is. That is, the frame 11 is manufactured by injection molding of a synthetic resin, and the thin-walled portions 11a and 11b are formed on both ends 11a and 11b in the thickness direction of the end of the frame 11 to which the covering portions 121 and 122 of the gasket body 12 are joined. Steps 111a and 111b are formed as boundaries between 111 and other portions. Of course, the thickness of the thin portion 111 is appropriately set in consideration of the rigidity to be secured. In addition, the other part is comprised similarly to 1st embodiment shown in FIGS. 1-3 demonstrated previously.

  According to the fuel cell gasket 10 of the second embodiment having the above configuration, in addition to the same effects as those of the first embodiment, the thin portion 111 is formed at the end of the frame 11. Since the covering portions 121 and 122 are thickened by the amount, the shape of the rubber material of the covering portions 121 and 122 can be enhanced when the gasket body 12 is integrally formed with the frame 11. For this reason, it is possible to prevent molding defects of the covering portions 121 and 122 and to secure a required bonding strength with the frame 11.

Next, FIGS. 7 to 9 show a third embodiment of the fuel cell gaskets.

  In the fuel cell gasket 10 of this embodiment, two pairs of seal beads 124a and 124b are formed on the seal portion 124 of the gasket body 12 so as to protrude to both sides in the thickness direction. The other parts are configured in the same manner as the second embodiment shown in FIGS. 4 to 6 described above, that is, the part of the frame 11 where the covering parts 121 and 122 of the gasket body 12 are joined ( A thin portion 111 is formed at the end of the refrigerant flow path C side.

  According to the fuel cell gasket 10 of the third embodiment having the above-described configuration, in addition to the same effects as those of the second embodiment, the seal portion 124 of the gasket body 12 has two pairs of seal beads 124a and 124b. Therefore, the assembled state between the gasket receiving grooves 32 and 42 of the separators 30 and 40 is stable. Therefore, in the stacked state shown in FIG. 8, the upper and lower fuel cell gaskets 10 and 10 are slightly displaced due to the assembly accuracy. However, the sealing performance is compensated, and the seal beads 124a and 124b are not easily tilted when compressed between the gasket receiving grooves 32 and 42.

Next, FIGS. 10 to 12 shows a fourth embodiment of the fuel cell gaskets.

  The fuel cell gasket 10 of this embodiment is provided with more rows of seal beads 124a, 124b than in the third embodiment, that is, three pairs of seal beads 124a, 124b in the seal portion 124 of the gasket body 12. As a result, the assembled state is further stabilized.

  In this embodiment, by increasing the number of seal beads 124a and 124b, the width W of the frame 11 is smaller than that of the third embodiment shown in FIGS. Therefore, when there is a concern that the handling property at the time of assembly is impaired or the reinforcing function for the gasket body 12 is impaired, it is desirable to increase the width W of the frame 11.

In the fifth embodiment of the gasket for a fuel cell shown in FIGS. 13 to 15 , the width W of the frame 11 is made larger than the embodiment shown in FIGS. is there. By constituting in this way, handling property and rigidity at the time of assembly can be secured.

DESCRIPTION OF SYMBOLS 1 Fuel cell 10 Gasket 11 for fuel cells Frame 111 Thin part 12 Gasket main body 121,122 Cover part 123 Connection part 124 Seal part 20 Electric power generation body 30,40 Separator (cell component)
C Refrigerant flow path (area to be sealed)

Claims (2)

In the fuel cell gasket interposed between the cell components of the fuel cell,
A synthetic resin frame having a shape surrounding a region to be sealed between the cell parts;
A rubber-made elastic gasket body integrally joined to the frame ;
With
The gasket body is
A covering portion joined to cover the both ends in the thickness direction of the end portion on the end portion on the seal target region side of the frame;
A connecting portion extending from the covering portion to the sealing target region side and joined to a surface of the frame facing the sealing target region side and formed thicker than the frame;
A seal portion extending from the coupling portion toward the seal target region and being in close contact with the cell component in a compressed state ;
A portion of the frame where the covering portion of the gasket body is joined is provided with a thin portion,
A fuel cell gasket. Wherein the seal portion, the fuel cell gasket according to claim 1, wherein the gasket pairs sealing bead that protrudes in the thickness direction on both sides of the body is formed, characterized in that.

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