JP2010055892A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell not obstructing fluid flow and sufficiently keeping the sealing property in a connection part even when a pipe line is deformed or displaced by outside force or inner pressure of pressure fluid acting to the pipe line in the structure of a connection part of an end plate and the pipe line for fluid such as gas or cooling water in the fuel cell. <P>SOLUTION: The end plates 20, 20 are arranged on both sides of a cell stack 100 of the fuel cell, a pipe line 30 made of resin is communicated with a manifold through which fluid such as fuel gas circulated, and in this state, a flange 33 of the pipe line 30 and the end plate 20 on one side are joined, a recessed groove 21 having no end is formed in the periphery of a through-hole 20a on the surface of the end plate, a sealing material 40 having no end is housed in the recessed groove, the flange 33 and the end plate 20 are joined in such attitude that a sealant 40 is pressed by a projection 34 formed in the position corresponding to the recessed groove 21 on the surface of the flange, and the through-hole 20a and the pipe line 30 form a passage having the same hollow section. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more particularly, to a structure of a connection portion between an end plate forming a fuel cell stack and various gas and cooling medium pipes.

  A polymer electrolyte fuel cell includes a membrane electrode assembly (MEA) comprising an ion-permeable electrolyte membrane, an anode-side catalyst layer and a cathode-side catalyst layer sandwiching the electrolyte membrane, and a membrane electrode assembly (MEA). A separator is arranged on the outer side to form a single cell. A gas diffusion layer (GDL) for promoting gas flow and enhancing current collection efficiency is provided outside each catalyst layer to form a membrane electrode assembly (MEGA: MEA and GDL assembly). There is also a form in which a separator is disposed outside the diffusion layer. Actually, these single cells are stacked by the number of stages according to the power generation performance, and a fuel cell stack is formed.

  In the fuel cell described above, hydrogen gas or the like is provided as the fuel gas to the anode electrode, oxygen or air is provided as the oxidant gas to the cathode electrode, and the gas diffused in the gas diffusion layer is led to the electrode catalyst. An electrochemical reaction takes place. In this electrochemical reaction, protons (hydrogen ions) and water generated at the anode electrode pass through the electrolyte membrane in a hydrated state to reach the cathode electrode, and generated water is generated at the cathode electrode.

  The above-mentioned MEA (or MEGA) or separator is supplied with a fuel gas, an oxidant gas, a manifold into which a cooling medium (cooling fluid) for suppressing the temperature rise of the membrane electrode assembly flows, or a fluid discharged from the cell. A manifold that flows out to the outside is formed in the cell stacking direction. Then, through holes formed in one of the end plates on both sides of the fuel cell stack and this manifold communicate with each other, communicate with gas tanks, etc., and pipes (fluids, hoses, etc.) for fluids composed of various gases and cooling media The fuel cell stack is formed by the end portion of the end plate communicating with the through hole of the end plate.

  The conventional fluid conduit is formed from a metal material. Since this fluid is generally a pressure fluid, the pipe line receives an internal pressure from the pressure fluid, but sufficient rigidity is ensured because of the metal material. In addition, in the process of assembling the pipeline extending from the fuel cell to a gas tank, various external forces act due to product errors such as bends in the pipeline and tank and pipeline placement accuracy, and assembly errors. (Torsion, bending, shearing, etc. acting when trying to) and various external stresses (bending stress, shearing stress, torsional stress, etc.) can occur in the pipe line. It could resist the rigidity of the pipeline.

  However, on the other hand, the pipe formed from the metal material is heavier, which contributes to an increase in the weight of the entire fuel cell. In recent years, there has been an urgent need to reduce the weight of hybrid vehicles and electric vehicles. In light of the urgent issue of reducing the weight of fuel cells mounted on these vehicles, instead of this metallic conduit, A lighter resin conduit for fluid is going to be connected to the end plate.

  Although it is possible to reduce the weight of the fuel cell by using a resin conduit for fluid, its rigidity is lower than that of a metal conduit, and the internal pressure received from the pressure fluid and the external force received during assembly It becomes easy to deform | transform or displace by etc. As a result, gaps (openings) are likely to occur at the connection between the resin material pipe line and the end plate, and fluid sealing properties such as various gases and cooling media are secured between the end plate and the pipe line. The new challenge of becoming difficult will arise, and the elimination of this challenge is an important development goal in this field.

By the way, Patent Documents 1 and 2 can be cited as published techniques relating to the fluid seal structure at the connection portion between the pipe line and the peripheral edge of the through hole of the end plate.
In the fuel cell system disclosed in Patent Document 1, an end portion of a resin material pipe line is fitted into a through hole of an end plate, and a flange and an end plate projecting from the side surface of the pipe line are bolted together. By providing a reinforcing member having a lower coefficient of linear expansion and higher Young's modulus (high rigidity) at the end of the pipe line fitted into the through hole of the end plate, the pipe connection part Therefore, it is intended to suppress the dimensional change due to the temperature change and the temporal deterioration due to the dimensional change.

  However, in the connection structure of the pipe line and the end plate in this fuel cell system, the pipe line fits inside the through hole of the end plate, and the inner dimension of the through hole is eroded, thereby inhibiting the fluid flow, Problems such as exciting turbulence in the fluid are likely to occur. The obstruction of the fluid flow leads to insufficient provision of various gases, insufficient electrode cooling function, and the like, and directly leads to a decrease in power generation performance.

  On the other hand, in the connection structure of the pipe line and the end plate in the fuel cell stack disclosed in Patent Document 2, an insulating grommet is arranged on the surface of the through hole of the end plate, and the inner space of the pipe line and the inner space of the insulating grommet are substantially the same. It is considered that the above-described problem that can occur with the technique of Patent Document 1 is solved by the fact. In this connection portion, a seal structure is formed at a portion where both the end portion of the insulating grommet and the end portion of the pipe line overlap in the stacking direction. However, in this seal configuration, when the pipe line is deformed or the pipe line is displaced due to an external force acting and an opening is generated between the end of the insulating grommet and the end of the pipe, It is inevitable that the sex will decline.

JP 2006-59652 A JP 2006-49129 A

  The present invention has been made in view of the above problems, and relates to a structure of a connection portion between an end plate in a fuel cell and a conduit for a fluid such as a gas or a cooling medium without impeding fluid flow. A fuel cell capable of sufficiently ensuring the sealing performance of the connecting portion even when the pipe is deformed or displaced by an external force acting on the pipe during assembly or an internal pressure received from a pressure fluid flowing inside the pipe. The purpose is to provide.

  In order to achieve the above object, a fuel cell according to the present invention includes a plurality of fuel cells stacked to form a cell stack, and end plates are arranged on both sides of the cell stack, and the cell stack is stacked in the stacking direction. The formed through hole and the through hole of the end plate communicate with each other to form a manifold through which a fluid composed of a fuel gas, an oxidant gas, and a cooling medium flows, and a conduit of a resin material through which the fluid flows communicates with the manifold. In the fuel cell, the fuel cell stack is formed by being fastened to the end plate in the posture, and the pipe line has a flange projecting to the outside, and a fastening means is interposed between the flange and the end plate. In the end plate, an endless concave groove is formed in the periphery of the through hole on the surface of the end plate on the side where the pipe line is disposed, and an endless sealing material is formed in the concave groove. Is housed A projection is formed at a position corresponding to the concave groove on the flange surface facing the concave groove, and the flange and the end plate are fastened in a posture in which the sealing material is pressed by the projection, The through hole of the end plate and the pipe line form a flow path having the same inner cross section.

  The fuel cell of the present invention is fastened with an end plate disposed on both sides of the cell stack constituting the fuel cell, and a posture positioned in a fluid through-hole formed in one of the end plates. The present invention relates to a connection structure with a resin pipe for fluid.

  This resin material pipe is lighter in weight than conventional metal pipes, and moreover it is less rigid than a metal pipe, but it is assembled in the pipe. It has sufficient rigidity to resist the stress of time and the pressure received from the pressure fluid passing through the inside. Moreover, the deformation | transformation performance (flexibility) is improving by shape | molding from the resin raw material. However, the rigidity and flexibility of the pipe line change not only with the material properties of the material resin, but also with its cross-sectional rigidity and length, etc. A pipe line having properties is used.

  As the material resin of this pipe line, a thermosetting resin can be used from the viewpoint of its rigidity, strength, dimensional stability, material cost, etc. For example, unsaturated polyester, vinyl ester, epoxy, phenol, polyimide, etc. These copolymers and two or more of these mixed materials can be used. In addition, thermoplastic resins can be used from the viewpoint of dimensional stability, material cost, productivity, heat resistance, chemical resistance, rigidity, etc., for example, polycarbonate resin, styrene resin, polyamide resin, polyester resin, polyphenylene Polyolefin resins such as sulfide resin (PPS), polyphenylene ether resin (PPE), polyacetal resin (POM), polyetherimide resin (PEI), polypropylene resin (PP), and polyethylene resin (PE) can be used. Of these, one or two or more mixed materials can be used.

  The resin material pipe line consists of a main part through which gas and cooling medium (cooling water, cooling air, cooling ethylene glycol, etc.) flow, and a flange projecting outward from the main part. In the abutting posture, both are fastened through fastening means such as bolts.

  In the end plate, an endless concave groove is formed at the periphery of the through hole on the surface on the side where the pipe line is disposed. An endless seal material (for example, a ring-shaped fixed seal material such as an O-ring or a material that is filled with an amorphous seal material and hardened into a ring shape) is accommodated in the groove. The “peripheral edge of the through-hole” here means a position spaced apart from the through-hole formed in the end plate by a certain distance, and a circular outline or rectangular outline so as to surround the through-hole at this position. An endless concave groove having a contour such as a square contour or an elliptical contour is formed.

  On the other hand, a protrusion is formed at a position corresponding to the groove on the flange surface of the pipe line facing the groove, and the flange and the end plate are fastened in a posture in which the sealing material is pressed by the protrusion. It is like that. Due to the pressing posture of the concave groove and the projection that presses the sealing material in the concave groove (which is also preferably endless), a sealing structure with excellent sealing performance against the fluid flowing in the pipe line and manifold is obtained. It is formed.

  Further, in the posture in which the end plate and the flange are fastened, the inner hollow section (inner hollow dimension or inner diameter) of the pipe line and the inner hollow section of the end plate through hole have the same inner hollow dimension or inner diameter. It is what you are doing.

  Since both have the same internal cross-section, the fluid flow is obstructed or turbulent in the fluid in the problem of the prior art described above, that is, in the flow path of the connection portion between the pipe and the end plate. There is no problem of being excited, and there is no risk of a decrease in power generation performance of the fuel cell due to these problems.

  In another embodiment of the fuel cell according to the present invention, a plurality of fuel cells are stacked to form a cell stack, end plates are arranged on both sides of the cell stack, and the stacking direction of the cell stack is The through hole formed in the end plate and the through hole of the end plate communicate with each other to form a manifold through which a fluid composed of a fuel gas, an oxidant gas, and a cooling medium flows, and a pipe of a resin material through which the fluid flows flows into the manifold In the fuel cell, the fuel cell stack is formed by being fastened to the end plate in a communicating posture, and the pipe line has a flange projecting outside thereof, and the flange and the end plate are elastic between both. The end plate surface facing the flange and the flange surface facing the end plate are fastened via a fastening means in a posture with a sealing material interposed therebetween. Either or both of them have endless protrusions, and when the flange and the end plate are fastened, the endless protrusions are embedded in the sealing material and penetrate the end plate. The hole and the pipe form a flow path having the same internal cross section.

  In the fuel cell according to the present embodiment, an elastic sealing material spreading in a plane is interposed between the end plate and the flange constituting the pipe line, and further, either or both of the end plate and the flange are sealed. An endless protrusion is formed on the side surface, and the endless protrusion is embedded in the sealing material in the fastening posture. With this configuration, a sealing structure having excellent sealing properties is formed for fluid flowing in the pipe line and the manifold.

  Here, the elastic sealing material is preferably a rubber material from the viewpoint of material cost, deformability, and rigidity. Specific examples thereof include natural rubber, styrene butadiene rubber, SBS rubber, and liquid polymerized styrene-butadiene rubber. Styrene copolymer rubber, polyisobutylene rubber, butyl rubber, butadiene rubber, isoprene rubber, alphine rubber, nitrile rubber, fluorine rubber, vinyl pyridine rubber, silicone rubber, butadiene-methyl methacrylate rubber, acrylic rubber, urethane rubber, etc. .

  Also in this embodiment, in the posture in which the end plate and the flange are fastened, the inner hollow section (inner hollow dimension or inner diameter) of the pipe line and the inner hollow section of the through hole of the end plate are the same, that is, the same. It has an inner space size or an inner diameter, so that problems such as hindering fluid flow and exciting turbulence in the fluid do not occur.

Here, in the pipe line described above, it is preferable that the flange has high rigidity as compared with other pipe line parts (such as a pipe main body part or a branch pipe branching from the main body part).
Both the main body and the flange of the pipe line are molded from a resin material, but by making the flange relatively rigid, the main body can be deformed (flexible) against the applied pressure and external force. It is easy to deform due to the property, and stress (bending stress, tensile stress, etc.) in the vicinity of the connecting portion with the flange in the main body portion can be minimized. Furthermore, since the flange is relatively high in rigidity, the opening between the end plate and the flange can be effectively suppressed.

  As described above, in a pipe line in which the main body and the flange are generally formed integrally, as one measure for changing the rigidity between the main body and the flange, when performing injection molding using a resin (matrix resin) of an arbitrary material In addition, there may be mentioned a method in which a base material made of reinforcing fiber is disposed in the flange forming cavity, and only the flange of the formed pipe line is formed from a fiber reinforced resin material.

  Here, as the matrix resin used, for example, the thermosetting or thermoplastic resin described above can be used. Reinforcing fibers include metal fibers such as aluminum fibers and stainless steel fibers, polyacrylonitrile-based, rayon-based, lignin-based, pitch-based carbon fibers, graphite fibers, glass fibers, and other insulating fibers, aramid fibers, polyphenylene sulfide. Organic fibers such as fibers, polyester fibers, acrylic fibers, nylon fibers, and polyethylene fibers, and inorganic fibers such as silicon carbide fibers and silicon nitride fibers can be used.

  In addition, as another measure for changing the rigidity of both the main body and the flange, a partition is provided in the cavity of the mold, more specifically, at the boundary between the cavity for the main body and the cavity for the flange, By injecting resin of different materials into both cavities and forming the pipeline by removing the partition before the resin hardens, it is possible to form pipelines with different rigidity between the main body and the flange based on the material properties .

  In another embodiment of the fuel cell according to the present invention, an engagement portion is provided on a peripheral edge of a through hole on a surface of the end plate on the side where the pipe line is disposed, and the pipe In a posture in which the path and the end plate are fastened, an engaged part is provided at a position corresponding to the engaging part of the pipeline, and when the fastened, the engaged part and the engaged part are engaged. The part is engaged.

  In the present embodiment, an engaging portion is provided on the periphery of the through hole of the end plate, and an engaged portion that engages with the engaging portion is provided in a connection region of the pipe, for example, the main body portion and the flange. Both are engaged by simply pressing the pipe.

  In this embodiment, in addition to being able to easily engage the end plate and the pipe line, even when the above-described external force or the like acts on the pipe line, it is possible to effectively suppress the lifting of the pipe line. In addition, the fluid sealability is further improved by suppressing the opening between the pipe and the end plate.

Moreover, regarding the structure of the pipe line, at least an embodiment in which a leg region rising from a connection portion with the end plate is a bellows structure may be used.
By making at least the leg region of the pipe a bellows structure, the deformation performance in the area is improved, and both the generated stress in the part of the pipe and the generated stress in the flange due to this can be reduced. This can lead to suppression of opening between the pipe and the end plate.

  As can be understood from the above description, according to the fuel cell of the present invention, regarding the structure of the connection portion between the end plate in the fuel cell and the conduit for fluid such as gas and cooling medium, the conduit is made of resin material. By doing so, the weight of the fuel cell can be reduced. In addition, in the connection portion, the pipe does not obstruct the flow of fluid such as gas and cooling water flowing through the pipe and the manifold, and further, the pipe by the external force acting on the pipe and the internal pressure received from the pressure fluid when the pipe is assembled. Even when is deformed or displaced, it is possible to sufficiently ensure the sealing performance of the connection portion between the pipe line and the end plate.

  Embodiments of the present invention will be described below with reference to the drawings. In the illustrated example, the fuel cell is a so-called flat type module cell, and the separator has a three-layer structure, but the separator has a conventional general structure, that is, meanders on one side thereof. Alternatively, the gas flow channel groove may be formed and the cooling medium flow channel meandering on the other side may be formed.

  FIG. 1 is an exploded perspective view of a stack of fuel cells, an end plate, and a pipe line. The cell stack 100 is formed by stacking a desired number of fuel cells 10 according to power generation performance, end plates 20 and 20 are arranged on both sides of the cell stack 100, and a tension plate (not shown). A fuel cell is formed by stacking and insulators and the like and stacking them with a given compressive force. The cell stack 100 includes a manifold that extends in the stacking direction to provide oxidant gas, fuel gas, and cooling water to each cell, and oxidant gas, fuel gas, and cooling that have flown through the cell stack. Manifolds M,... For flowing water out of the stack are provided.

  The fuel cell 10 includes a membrane electrode assembly 11 (MEGA) including an electrolyte membrane, a cathode electrode layer and an anode electrode layer sandwiching the electrolyte membrane, and a cathode side and anode side gas diffusion layer (GDL) sandwiching the electrolyte membrane. And separators 12 and 12 on the cathode side and the anode side that sandwich the MEGA 11.

  Here, the electrolyte membrane is a fluorine-based ion exchange membrane having a sulfonic acid group or a carbonyl group, a non-fluorine-based material such as a substituted phenylene oxide, a sulfonated polyaryletherketone, a sulfonated polyarylethersulfone, or a sulfonated phenylene sulfide. It is formed from a polymer or the like. The electrode layer is made of a porous material in which a catalyst made of platinum or an alloy thereof is supported on carbon or the like, and the gas diffusion layer is made of a gas permeable material such as carbon paper or carbon cloth.

  In addition, the separator 12 of the so-called flat type module has a three-layer structure, a surface material that defines a cell between adjacent single cells, and a separate surface material on the MEGA side facing the surface material, A spacer made of a resin material that is interposed between these two face materials and formed in a frame shape (endless shape) along the outer peripheral contour of each face material (not shown). The face material is formed of a gas-impermeable dense carbon material, dense graphite material, or the like, and a plurality of projections (dimples) (not shown) are provided on the side surface of the one face material facing the other face material. When the projection has a height corresponding to the thickness of the spacer, when the three-layer structure is formed, the tip of the projection comes into contact with the side surface of the face material, and turbulently flows between the projections. A flow path of the flowing cooling water is formed. Note that a gas flow path layer made of expanded metal is interposed between the separator 12 having the three-layer structure and the membrane electrode assembly 11.

  A fuel cell system mounted on an electric vehicle or the like includes a fuel cell, various tanks for storing hydrogen gas and air, a blower for providing these gases to the fuel cell, and a radiator for cooling the fuel cell. The battery is generally composed of a battery that stores electric power generated by the fuel cell, a drive motor that is driven by the electric power, and the like.

  The end plate 20 has a through hole 20a for the oxidant gas to flow (X1 direction), the through hole 20a 'for the oxidant gas flowing through the cell stack 100 to flow (X1' direction), fuel Through hole 20b for gas to flow in (X2 direction), through hole 20b ′ for fuel gas flowing through cell stack 100 to flow out (X2 ′ direction), and cooling water to flow in (X3 direction) Through holes 20c, and through holes 20c 'through which the cooling water flowing through the cell stack 100 flows out (in the X3' direction) are attached in a posture communicating with a unique manifold.

  The pipe line 30 includes a main body 31, three branch pipes 32 a, 32 b, 32 c extending from one end thereof, and a flange 33 projecting outward at the other end of the main body 31. These are integrally molded by injection molding. The branch pipes 32a, 32b, and 32c are used to circulate any of oxidant gas, fuel gas, and cooling water, and the illustrated example shows the branch pipes 32a, 32b, and 32c cut along the way. Actually, however, the tip is connected to a gas tank or a radiator.

  Here, the pipe line 30 is, for example, an unsaturated polyester, vinyl ester, epoxy, phenol, polyimide, or the like, which is a thermosetting resin, a copolymer thereof, a resin in which two or more of these are mixed, or Polycarbonate resin, styrene resin, polyamide resin, polyester resin, polyphenylene sulfide resin (PPS), polyphenylene ether resin (PPE), polyacetal resin (POM), polyetherimide resin (PEI), polypropylene resin (PP ), One or two or more mixed materials of polyolefin resins such as polyethylene resin (PE) can be used.

  2 is an enlarged view of a portion II in FIG. 1, and FIG. 3 is a view taken in the direction of arrows III-III in FIG. 1, both of which connect the elements constituting the connecting portion between the end plate 20 and the pipe line 30. It is a figure explaining the previous state.

  As shown in FIG. 2, endless grooves 21,... Are formed on the surface of the end plate 20 at the periphery of each through hole 20 a,. An endless seal member 40 (in the illustrated example, an O-ring) having the same contour as the concave groove 21 is accommodated therein.

  Further, on the surface of the flange 33 of the pipe line 30, when the end plate 20 and the pipe line 30 are fastened, endless protrusions 34 are provided at positions corresponding to the concave grooves 21,. The projections 34 are provided at positions that surround the through holes 33a, 33b, and 33c provided at positions corresponding to the manifolds.

  The sealing material 40 is accommodated in the endless concave groove 21, the end plate 20 and the pipe line 30 are brought into contact with each other in this state, and bolts (not shown) are screwed into the coaxial bolt holes 20 d and 35 opened on both sides. Thereby, the connection structure of the end plate 20 and the pipe line 30 is formed.

  Since the pipe line 30 is formed from resin, the weight of the entire fuel cell including the pipe line is much lighter than that of a fuel cell having a conventional metal material pipe line. Further, since it is made of resin, the deformation performance of the main body portion 31 of the pipe line 30 is improved, and when the branch pipe lines are assembled to a gas tank or the like, an external force is applied to the main body section 31 due to an assembling error or the like. This external force can be absorbed by the deformation of the flexible main body portion 31 even when acted on. Therefore, even when an external force is applied, excessive bending stress, tensile stress, or the like hardly occurs in the flange 33 connected to the main body portion 31. This leads to suppression of the opening that may occur between the flange 33 and the end plate 20 due to the external force, and leads to securing the fluid sealability in this connection structure.

  FIG. 4 shows another embodiment of the pipe line. In the pipe line 30A, the main body 31A rising from the flange 33 has a bellows structure. Since the main body 31A has a bellows structure, the deformation performance can be further improved.

  5 to 8 are longitudinal cross-sectional views illustrating an embodiment relating to a connection structure between an end plate and a pipe line. In each of the drawings, one manifold M and through hole in the connection structure are taken up and described. However, the connection structure shown in FIG. 1 applies to all six manifolds M and through holes in FIG.

The connection structure shown in FIG. 5 is a structure formed when the end plate 20 and the pipe line 30 shown in FIGS.
By pressing the flange 33 of the pipe line 30 against the end plate 20 via the bolt B, the endless protrusion 34 crushes the sealing material 40 in the endless concave groove 21, and the end plate 20 and the flange 33 are connected. A seal structure in the part is formed.

  As shown in the drawing, in this fastening posture, the inner hollow section of the manifold M composed of the coaxial fluid through-holes opened in the respective laminates 10,... And the through-holes 20 a of the end plate 20, The inner hollow section of the main body 31 has the same dimensions (same inner diameter).

  Accordingly, the gas (in this case, the oxidant gas) flowing through the main body portion 31 of the pipe line can flow into the manifold M without hindering its flow, and effective gas supply to each fuel cell can be achieved. Realized.

  The connection structure shown in FIG. 6 is formed between an end plate 20A having endless projections 22 on the periphery of each through hole (in the illustrated example, through hole 20a) and a flange 33A having a flat surface constituting the pipe line 30B. In this connection structure, both are fastened in a posture in which the planar sealing material 50 is interposed.

  The planar sealing material 50 is made of, for example, rubber, and the endless protrusion 22 is embedded in the planar sealing material 50 in the fastening posture, thereby forming a seal structure at the connection portion between the end plate 20A and the flange 33A. The Specific examples of the rubber material include natural rubber, styrene butadiene rubber, SBS rubber, styrene copolymer rubber such as liquid polymerized styrene-butadiene rubber, polyisobutylene rubber, butyl rubber, butadiene rubber, isoprene rubber, alphine rubber, nitrile. Examples thereof include rubber, fluororubber, vinylpyridine rubber, silicone rubber, butadiene-methyl methacrylate rubber, acrylic rubber, and urethane rubber.

  The connection structure shown in FIG. 7 is substantially the same as the connection structure of FIG. 5 except that the pipe line 30C in FIG. 7 is formed of a different material resin in the main body 31 and the flange 33B. That is. For example, the main body portion 31 is made of any one of the above-described material resins, and the flange 33B is made of the same material resin as the main body portion 31 as a matrix resin, and the reinforcing fibers are disposed therein to increase the rigidity. Is. Here, specific examples of the reinforcing fibers include metal fibers such as aluminum fibers and stainless fibers, polyacrylonitrile-based, rayon-based, lignin-based, pitch-based carbon fibers, graphite fibers, glass fibers, and other insulating fibers, Mention may be made of organic fibers such as aramid fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, nylon fibers and polyethylene fibers, and inorganic fibers such as silicon carbide fibers and silicon nitride fibers.

  According to the connection structure of FIG. 7, in addition to the endless projection 34 crushing the sealing material 40 in the endless concave groove 21 to form a seal structure, the pipe line 30 </ b> C is more than the main body portion 31. By having the high-rigidity flange 33B, even when an external force acts on the flange 33B and the main body 31 is deformed, the high-rigidity flange 33B does not open the opening due to this deformation, and the close contact posture with the end plate 20 Can be secured, and a connection structure with even better sealing performance can be formed.

  In the connection structure shown in FIG. 8, the engagement hook 23 is provided at the periphery of the through hole of the end plate 20B, and in the connection region between the main body 31 and the flange 33C in the conduit 30D, the main body 31 is opposite to the flange 33C. This is an embodiment in which an engaged hook 36 is provided, and the engagement hook 23 and the engaged hook 36 are engaged by pressing the pipe line 30D against the end plate 20B. Also in this embodiment, after the hooks are engaged with each other, the end plate 20B and the flange 33C are fastened by the bolt B, and a given seal structure is formed. Also in this embodiment, the inner hollow section of the manifold M and the inner hollow section of the main body portion 31 (including the engaged hook 36 of the engaging portion) of the pipe line 30D have the same dimensions (same inner diameter). .

  In this embodiment, in addition to being able to easily engage the end plate 20B and the flange 33C of the pipe line 30D (therefore, both can be easily positioned when tightening the bolt), the engagement between the hooks causes external force and the like. Even when acting on the pipe line 30D, the floating of the pipe line 30D can be effectively suppressed. Thereby, the opening between the pipe line 30 </ b> D and the end plate 20 </ b> B is suppressed, and a connection structure with further excellent sealing performance can be formed.

  According to the connection structure of the end plate and the flange of the pipe line shown in the figure, the pipe line is formed from a resin material, so that the weight of the entire fuel cell including the pipe line can be reduced. Excellent fluid sealability can be imparted between the end plate and the flange constituting the pipe line.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

It is a disassembled perspective view of the laminated body of a fuel cell, an end plate, and a pipe line. It is an enlarged view of the II section of FIG. It is the III-III arrow line view of FIG. It is a perspective view of other embodiment of a pipe line. It is a longitudinal cross-sectional view of one Embodiment of the connection structure of a pipe line and an end plate. It is a longitudinal cross-sectional view of other embodiment of the connection structure of a pipe line and an end plate. It is a longitudinal cross-sectional view of further another embodiment of the connection structure of a pipe line and an end plate. It is a longitudinal cross-sectional view of further another embodiment of the connection structure of a pipe line and an end plate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 11 ... MEGA (membrane electrode assembly), 12 ... Separator, 20, 20A, 20B ... End plate, 20a ... Through-hole (for oxidant gas inflow), 20a '... Through-hole (oxidant gas) For discharge), 20b ... through hole (for fuel gas inflow), 20b '... through hole (for fuel gas outflow), 20c ... through hole (for cooling water inflow), 20c' ... through hole (for cooling water outflow), DESCRIPTION OF SYMBOLS 21 ... Endless concave groove, 22 ... Endless protrusion, 23 ... Engagement hook, 30, 30A, 30B, 30C, 30D ... Pipe line, 31 ... Main part, 32a, 32b, 32c ... Branch pipe line, 33 33A, 33B, 33C ... flange, 33a, 33b, 33c ... through hole, 34 ... projection, 36 ... engaged hook, 40 ... endless seal material (O-ring), 50 ... planar seal material, 100 ... Cell stack

Claims (6)

A plurality of fuel cells are stacked to form a cell stack, end plates are arranged on both sides of the cell stack, and the through holes formed in the stacking direction of the cell stack communicate with the through holes of the end plates. The fuel cell stack forms a manifold through which a fluid composed of a fuel gas, an oxidant gas, and a cooling medium circulates, and a pipe of resin material through which the fluid circulates is fastened to the end plate in a posture communicating with the manifold. In the formed fuel cell,
The pipe line has a flange projecting to the outside, and is fastened between the flange and the end plate via fastening means,
Of the end plate, an endless concave groove is formed in the peripheral edge of the through hole on the surface on which the pipe line is disposed, and an endless sealing material is accommodated in the concave groove,
A projection is formed at a position corresponding to the concave groove on the flange surface facing the concave groove, and the flange and the end plate are fastened in a posture in which the sealing material is pressed by the projection.
A fuel cell in which a through hole of an end plate and a pipe line form a flow path having the same internal cross section. A plurality of fuel cells are stacked to form a cell stack, end plates are arranged on both sides of the cell stack, and the through holes formed in the stacking direction of the cell stack communicate with the through holes of the end plates. A fuel cell, a oxidant gas, and a cooling medium are circulated through a manifold, and a resin material pipe through which the fluid circulates is fastened to the end plate in a posture communicating with the manifold. In the formed fuel cell,
The pipe line has a flange projecting to the outside, and the flange and the end plate are fastened through fastening means in a posture in which an elastic sealing material is interposed between both.
Endless protrusions are formed on either or both of the end plate surface facing the flange and the flange surface facing the end plate,
When the flange and the end plate are fastened, the endless protrusion is embedded in the seal material, and the through hole and the pipe line of the end plate form a flow path having the same inner cross section. ,Fuel cell.   3. The fuel cell according to claim 1, wherein, of the pipes, the flange is highly rigid as compared with other pipe parts.   4. The fuel cell according to claim 3, wherein the flange is made of a fiber reinforced resin made of a reinforced fiber and a matrix resin, and the other pipe portion is made of a matrix resin made of the same material as the flange. An engagement portion is provided on the periphery of the through hole on the surface of the end plate on the side where the pipe line is disposed,
In the posture where the pipe line and the end plate are fastened, an engaged part is provided at a position corresponding to the engaging part of the pipe line,
The fuel cell according to any one of claims 1 to 4, wherein when engaged, the engaging portion and the engaged portion are engaged.   The fuel cell according to any one of claims 1 to 5, wherein at least a leg region rising from a connection portion with an end plate has a bellows structure.

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