JP2008147103A - Manufacturing method for fuel-cell sealing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a fuel cell sealing structure that improves robustness in manufacturing while properly restricting a reduction in power generation region due to impregnation of a rubber material for gasket molding into each porous body constituting both sides in the thickness direction of a cell of a fuel cell. <P>SOLUTION: A filler made of a low viscosity or liquid rubber or a resin is impregnated into a region, having a prescribed width from the end face 1a of a power generation body 1, in each porous body 20 so as to form each impregnated part 21. After that or before that, recessed parts 1b, respectively having each engagement face 1c in the planar extension direction of the power generation body 1, are formed in the end face 1a of the power generation body 1 at prescribed intervals. The power generation body 1 is set in a die while the die inner face is brought into close contact with each impregnated part 21. A molding rubber material is filled into a cavity defined between the end face 1a and the die inner face so as to be crosslinked and cured. Consequently, it is possible to mold a gasket 3 that is joined to the power generation body 1 while being firmly and adheringly engaged with the power generation body. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a gasket for sealing a flow path formed between fuel cells of a fuel cell stack, and a gasket integrated part in which GDLs on both sides in the thickness direction of the power generator of the fuel cell are integrated. It relates to a method of manufacturing.

  The fuel cell has GDL (Gas Diffusion Layer) on both sides in the thickness direction of MEA (Membrane Electrode Assembly) with a pair of electrode layers on both sides of the electrolyte membrane (ion exchange membrane). A stack in which a power generation body made of MEA in which a porous gas diffusion electrode layer is disposed on both surfaces of the power generation body disposed on the electrolyte membrane is sandwiched between separators to form a fuel cell, and a number of these fuel cells are stacked. It has a structure. Then, the oxidizing gas (air) is supplied from the oxidizing gas flow path formed on one surface of each separator to the cathode side of the power generator via one GDL, and the fuel gas (hydrogen) is supplied to each separator. The fuel gas flow path formed on the other surface is supplied to the anode side of the power generator through the other gas diffusion layer, and the electrochemical reaction, which is the reverse reaction of water electrolysis, that is, water from hydrogen and oxygen is removed. Electric power is generated by the reaction to be generated.

  For this reason, each fuel battery cell is integrally provided with a gasket for sealing a fuel gas, an oxidant gas, water generated by the above-described electrochemical reaction, surplus air, etc., for example, in the fuel cell. A fuel cell seal structure as a cell seal is formed. 11 and 12 are cross-sectional views showing an example of a conventional fuel cell seal structure.

  In this fuel cell seal structure, reference numeral 100 is a power generator composed of an electrolyte membrane 111 and an MEA 110 comprising a pair of electrode layers 112 and 112 provided on both sides thereof, and GDLs 120 and 120 provided on both sides thereof. is there. The power generator 100 is integrally formed with a gasket 200 made of a rubber-like elastic material.

In the fuel cell seal structure shown in FIG. 11, the molding rubber material is shaped through the through-hole 100 a opened in the power generation body 100, so that the gaskets 200 and 200 each having the seal lip 201 are formed into the power generation body 100. Are formed in a shape in which the rubber material for molding is connected to each other in the through hole 100a via the portions 202 which are hardened. Further, at the time of molding, a part of the molding rubber material having low viscosity or liquid is impregnated into the GDL 120, 120 made of a porous body such as carbon fiber, so that the GDL 120, 120 is filled with the gasket 200, 200. The rubber-impregnated portions 121 and 121 that are continuous with each other are formed so as to prevent permeation leakage from the GDLs 120 and 120 (see, for example, Patent Document 1 below).
JP 2003-7328 A

  However, in the structure shown in FIG. 11, the compressive load acting on the gaskets 200, 200 by the separators 300, 300 on both sides in the assembled state as a stack also acts on the GDLs 120, 120. Excessive load may be applied.

  Therefore, in the fuel cell seal structure shown in FIG. 12, the gasket 200 is oriented in the plane extension direction of the power generator 100 so that the compressive load of the gasket 200 by the separator 300 does not act on the GDLs 120 and 120. It is formed into a shape having a base 203 extending endlessly along the end face 100a and seal lips 201, 201 formed on both sides thereof. When the gasket 200 is molded using a low viscosity or liquid molding rubber material, a part of the molding rubber material is impregnated in the peripheral portion of the GDL 120 or 120 made of a porous body such as carbon fiber. Rubber impregnated portions 121, 121 are formed, and the gasket 200 is firmly joined to the GDLs 120, 120 via the rubber impregnated portions 121, 121, and there is no permeation leakage from the GDLs 120, 120.

  However, since the porosity of the GDL 120 made of a porous material such as carbon fiber varies, the structure shown in FIG. 12 has a gasket 200 formed of a mold using a low-viscosity or liquid molding rubber material. When molding, it is difficult to appropriately limit the impregnation of the molding rubber material into the peripheral portion of the GDL 120, 120. For this reason, even if the filling pressure and viscosity of the molding rubber material are constant, the width W of the rubber-impregnated portions 121 and 121 becomes larger than necessary depending on the porosity and the like of the GDLs 120 and 120. There was a risk that the power generation area would be narrowed.

  The present invention has been made in view of the above points, and the technical problem is that the gasket is integrally formed in a state of being joined to the end face along the peripheral edge of the power generator. In the manufacture of the provided fuel cell seal structure, the reduction of the power generation area due to the impregnation of the gasket forming rubber material into the porous body constituting both sides in the thickness direction of the power generation body is appropriately limited, and the manufacturing robustness It is to improve the performance.

  As a means for effectively solving the technical problem described above, the method for manufacturing a fuel cell seal structure according to the invention of claim 1 is directed to an electric power generator of a fuel cell along an end surface facing the planar extension direction. In the production of the fuel cell seal structure in which the gasket is integrally provided, among the porous bodies constituting the both sides in the thickness direction of the power generation body, a low-viscosity or liquid state is formed in a region having a predetermined width from the end face. A step of forming an impregnated portion by impregnating a sealant made of rubber or resin and curing it by cross-linking, and then forming recesses having engagement surfaces with respect to the planar extension direction on the end surface of the power generator at predetermined intervals. A rubber material for molding in a cavity defined between the end surface and the inner surface of the mold, and the step of setting the power generator in the mold and bringing the inner surface of the mold into intimate contact with the impregnation portion Filled with cross-linked cured And a that process.

  According to a second aspect of the present invention, there is provided a method for manufacturing a fuel cell seal structure, wherein the molding rubber material impregnation / crosslinking curing according to the first aspect and the order of forming the recesses on the end face of the power generator are reversed. That is, a step of forming concave portions having engagement surfaces with respect to the planar extension direction of the power generation body at predetermined intervals on the end face of the power generation body, and then a porous material constituting both side portions in the thickness direction of the power generation body A step of forming an impregnated portion by impregnating a sealing material made of low-viscosity or liquid rubber or resin into a region having a predetermined width from the end face of the body and crosslinking and curing the power generation body in the mold And setting the inner surface of the mold in close contact with the impregnated portion, filling the cavity defined between the end surface and the inner surface of the mold with a molding rubber material, and crosslinking and curing. .

  Here, the power generation body means a power generation body in which a GDL made of a porous body is arranged on both sides in the thickness direction of the MEA provided with a pair of electrode layers on both sides of the electrolyte membrane, or a porous body on both sides of the electrolyte membrane. It includes a power generator having a gas diffusion electrode layer made of

  According to these methods, a sealing material made of a low-viscosity or liquid rubber or resin in advance in a region having a predetermined width from the end face of the power generation body among the porous bodies constituting both sides in the thickness direction of the power generation body. By impregnating and curing by crosslinking, this portion becomes an impregnation portion in which the continuous pores of the porous body are sealed with rubber or resin. Therefore, when the power generator is set in a mold and clamped, it is necessary / sufficient to seal a cavity defined between the end face of the power generator and the inner surface of the mold in the impregnated portion. A mold clamping force can be applied, and leakage of the molding rubber material filled in the cavity and penetration into the porous body can be prevented in the subsequent gasket molding process.

  In addition, since a recess having an engaging surface with respect to the planar extension direction of the power generator is formed in advance on the end face of the power generator, the molding rubber material filled in the cavity has a portion that flows into the recess. In the process of cross-linking and curing, the recesses are brought into close contact with each other, whereby the gasket is integrated with the power generator simultaneously with molding.

  According to the first or second aspect of the invention, it is possible to obtain a fuel cell seal structure having a gasket firmly joined to the power generator by close engagement with a recess formed on the end face thereof. And since the porous body in the power generation body is impregnated with a sealing material made of liquid rubber or resin in advance before molding the gasket, an impregnation portion having a certain width can be easily formed from the end face of the power generation body. In addition, since the molding rubber material that leaks from the cavity to the power generation area side in the gasket molding process is blocked by the impregnated portion, it is effective that the power generation area is narrowed by the penetration of the molding rubber. Can be prevented. In addition, in the gasket molding process, it is not necessary to increase the filling pressure in the cavity for the purpose of impregnating the porous material with the molding rubber material, thereby reducing the uncertainties necessary for various controls in the manufacturing process. Thus, robustness can be improved.

  Hereinafter, a preferred embodiment of a method for producing a fuel cell seal structure according to the present invention will be described with reference to the drawings. 1A and 1B show a part of a power generator 1 for carrying out a method for producing a fuel cell seal structure according to the present invention, wherein FIG. 1A is a sectional view and FIG. 1B is a plan view. That is, the power generator 1 shown in FIG. 1 has GDLs 20 arranged on both sides in the thickness direction of the MEA 10 in which a pair of electrode layers 12 are provided on both surfaces of the electrolyte membrane 11. The GDL 20 corresponds to the “porous body” described in claim 1 or 2 and is made of carbon fiber or the like.

  2A and 2B show a state in which an impregnation portion 21 is formed on the GDL 20 of the power generator 1 in the method for manufacturing a fuel cell seal structure according to the present invention, where FIG. 2A is a cross-sectional view and FIG. 2B is a plan view. It is. That is, the GDL 20 constituting both side portions in the thickness direction of the power generator 1 is made of a low-viscosity or liquid rubber or resin in a region having a predetermined width W from the end surface 1a facing the planar extension direction of the power generator 1 in advance. The impregnated portion 21 is formed by impregnating the sealing material and crosslinking and curing. In this step, for example, a method of impregnating the power generator 1 by immersing it in a liquid tank storing the sealing material to a predetermined depth, a method of applying and impregnating the sealing material by screen printing or dispenser extrusion, etc. Therefore, it is possible to easily form the impregnated portion 21 having a certain width W from the end face 1a of the power generator 1.

  As the above-mentioned sealing material, those that can penetrate into the continuous pores of GDL 20 and do not generate elution gas that adversely affects the power generation function in MEA 10 are preferable. For example, low-viscosity or liquid fluorine rubber, EPDM, silicone rubber, A rubber material such as acrylic rubber, or a resin material such as a low-viscosity or liquid epoxy resin, silicone resin, phenol resin, or urethane resin can be used.

  Thus, in the impregnation part 21 formed in the peripheral part of GDL20, the continuous pore by the gap | interval etc. between the fibers of GDL20 is filled with rubber | gum or resin, and it has the structure sealed.

  FIG. 3 shows a state in which the impregnated portion 21 is formed in the GDL 20 and the concave portion 1b is formed in the end surface 1a of the power generator 1, in the method for manufacturing the fuel cell seal structure according to the present invention. Sectional drawing and (B) are top views. That is, a large number of recesses 1b having engagement surfaces 1c with respect to the planar extension direction are formed at predetermined intervals on the end surface 1a of the power generator 1 in which the impregnated portion 21 is formed on the peripheral edge of the GDL 20. In the illustrated example, each concave portion 1b has a dovetail shape, and both inner side surfaces thereof are engaging surfaces 1c inclined substantially symmetrically so that the front end is narrowed toward the groove opening end side.

  The recess 1b can be easily formed by a method of punching at once using a jig, and the depth D of the recess 1b is smaller than the width W of the impregnation portion 21.

  FIG. 4 is an explanatory diagram showing a process of molding a gasket in the method for manufacturing a fuel cell seal structure according to the present invention. In other words, the power generator 1 in which the impregnated portion 21 is formed in the peripheral portion of the GDL 20 and a large number of the concave portions 1b are formed in the end surface 1a as described above is set in the mold 4. That is, the mold 4 is composed of an upper mold 41 and a lower mold 42 that are brought into contact with and separated from each other, and on the inner surfaces facing each other, the peripheral portion of the power generator 1, in other words, the impregnation portion 21 at the peripheral edge of the GDL 20 Clamping surfaces 41 a and 42 a that can be clamped by clamping are formed, and a cavity 43 is defined between the inner surfaces 41 b and 42 b that extend to the outer peripheral side and the end surface 1 a of the power generator 1. In the upper mold 41, a gate 44 is opened toward the cavity 43.

  The cavity 43 is a space for molding the gasket 3 shown in FIG. 5 described later. That is, the cavity 43 corresponds to the base molding portion 431 having a shape corresponding to the base 33 of the gasket 3 and the seal lips 32 and 32 of the gasket 3. The seal lip molding portions 432 and 432 are shaped. Then, when the power generator 1 is set in the mold 4 and clamped as shown in FIG. 4, the impregnation portion 21 in the GDL 20 of the power generator 1 causes the clamping surfaces 41 a and 42 a of the upper mold 41 and the lower mold 42. A clamping force (compression force) is received between them, that is, the clamping surfaces 41a and 42a, which are inner surfaces of the mold, and the impregnated portion 21 are brought into close contact with each other with an appropriate surface pressure.

  Next, the molding rubber material is filled into the cavity 43 from the molding machine (not shown) through the gate 44 in the clamped state shown in FIG. The molding rubber material that can be used here is preferably one that does not generate an elution gas that adversely affects the power generation function in the MEA 10. For example, low-viscosity or liquid fluorine rubber, EPDM, silicone rubber, acrylic rubber, or the like can be used. is there. As the molding method, LIM molding using a liquid molding rubber material, SIM molding or compression molding using a low viscosity molding rubber material is employed.

  Further, the peripheral edge portion of the GDL 20 of the power generator 1 is an impregnated portion 21 in which continuous pores due to gaps between fibers or the like are sealed with rubber or resin, so that the low-viscosity or liquid molding rubber in the cavity 43 is formed. The material does not penetrate into the GDL 20, and the impregnated portion 21 is in intimate contact with the clamping surfaces 41a and 42a of the upper die 41 and the lower die 42 with an appropriate surface pressure. Leakage is also prevented. Moreover, unlike the case where the GDL 20 is sandwiched between the clamping surfaces 41a and 42a, the compression rate restriction can be relaxed, and the filling pressure of the molding rubber material into the cavity 43 for the purpose of impregnating the GDL 20 with the molding rubber material. There is no need to use high pressure.

  In addition, the end face 1a of the power generation body 1 is formed with a plurality of dovetail recesses 1b having engagement surfaces 1c inclined substantially symmetrically so as to narrow the front end toward the groove shoulder side, so that a plurality of notches are formed at predetermined intervals. A part of the molding rubber material filled in the cavity 43 flows into each recess 1b and is cured by crosslinking.

  5A and 5B show a fuel cell seal structure manufactured according to the present invention, in which FIG. 5A is a sectional view and FIG. 5B is a plan view. That is, when the molding rubber material filled in the cavity 43 shown in FIG. 4 is cross-linked and cured, the upper mold 41 and the lower mold 42 are separated from each other to open the product (fuel cell seal structure). Take out. As shown in FIG. 5, the fuel cell seal structure has a power generator 1 in which GDLs 20 are provided on both sides of an MEA 10 composed of an electrolyte membrane 11 and electrode layers 12 on both sides thereof, and a plane extending direction thereof. And a gasket 3 made of a rubber-like elastic material integrally formed along the end face 1a.

  Specifically, the gasket 3 has a shape having a base 31 extending endlessly along the end surface 1a facing the planar extension direction of the power generator 1, and a seal lip 32 protruding from both sides in the thickness direction. 4 is a portion molded in the cavity 43. The gasket 3 and the power generation body 1 are connected to each other in a large number of dovetail-shaped recesses 1b formed on the end surface 1a of the power generation body 1 and a large number of protrusions 33 formed by crosslinking and curing in the recesses 1b. It is in close contact. And since the inclined engaging surface 1c in each recessed part 1b exhibits the engaging force in the plane extension direction of the electric power generation body 1 with respect to the to-be-engaged surface 33a of the protrusion 33 closely_contact | adhered to this, the gasket 3 The power generator 1 is joined in a state of being tightly engaged with the recess 1b and the protrusion 33.

  FIG. 6 is a cross-sectional view showing the relationship between the fuel cell seal structure manufactured as described above and the fuel cell separator. That is, this fuel cell seal structure constitutes a fuel cell together with the separator 5 indicated by the alternate long and short dash line in FIG. 6. In the assembled state, the seal lip 32 of the gasket 3 is appropriately applied to the separators 5 on both sides. By closely contacting in a compressed state, a sealing function against fuel gas, oxidizing gas, and the like is achieved. And since this gasket 3 is provided so that the outer periphery may be extended along the end surface 1a which faced the planar extension direction of the electric power generation body 1, the reaction force by compression of the seal lip 32 will become an excessive load to GDL20. Does not act directly.

  Moreover, since the peripheral part of GDL20 which is a porous body becomes the impregnation part 21 with which the continuous pores were plugged, and the outer peripheral side is surrounded by the gasket 3, gas etc. of sealing object of GDL20 It is possible to prevent the inside from moving in the plane extension direction and leaking into the outside.

  In the manufacturing method described above, the impregnation portion 21 is formed by impregnating the peripheral portion of the GDL 20 of the power generation body 1 to form the impregnation portion 21, and then the dovetail recess 1 b is formed on the end surface 1 a of the power generation body 1. On the contrary, after forming the dovetail-shaped recess 1b on the end face 1a of the power generator 1, the impregnation part 21 may be formed by impregnating the edge of the GDL 20 with a sealing material.

  FIG. 7 shows a state in which the concave portion 1b is formed in the end surface 1a of the power generator 1 before the formation of the impregnation portion in the GDL 20 as a manufacturing method according to another embodiment of the present invention. (B) is a plan view. That is, in this method, first, a large number of recesses 1b having engagement surfaces 1c with respect to the planar extension direction of the power generator 1 are formed at predetermined intervals on the end face 1a of the power generator 1 shown in FIG. In the illustrated example, each recess 1b has a dovetail shape, and both inner side surfaces thereof are engaging surfaces 1c that are inclined substantially symmetrically so that the front end is narrower toward the groove shoulder side.

  And after formation of the recessed part 1b, as FIG. 3 demonstrated previously demonstrates from the end surface 1a which faced the planar extension direction of the electric power generation body 1 among GDL20 which comprises the thickness direction both sides part of the electric power generation body 1. Then, the impregnated portion 21 is formed by impregnating a region having a predetermined width W larger than the depth D of the concave portion 1b with a sealing material made of low-viscosity or liquid rubber or resin and curing it. Subsequent steps are the same as those described above.

  Moreover, the shape of the recessed part 1b may be shapes other than dovetail shape, as long as it has the engaging surface 1c with respect to the planar extension direction of the electric power generation body 1. FIG. FIG. 8 shows an example of the shape, where (A) is a cross-sectional view and (B) is a plan view.

  That is, the recess 1b illustrated in FIG. 8 is formed in a bowl shape, and an engagement surface 1c with respect to the planar extension direction of the power generator 1 is formed in a step shape on the inner surface. The depth D is smaller than the width W of the impregnation portion 21. Also in this case, the concave portion 1b may be formed after the impregnated portion 21 is formed by impregnating the peripheral edge portion of the GDL 20 of the power generating body 1 or after forming the concave portion 1b. The impregnated portion 21 may be formed by impregnating the peripheral edge portion with a sealing material.

  Thereafter, the gasket is integrally molded by the molding process as shown in FIG. In this molding step, the recesses 1b formed in the power generation body 1 and a plurality of hook-shaped protrusions 33 formed by a part of the molding rubber material flowing into this and cross-linking and curing are in close contact with each other. . And the step-shaped engaging surface 1c in each recessed part 1b exhibits the engaging force in the plane extension direction of the electric power generation body 1 with respect to the to-be-engaged surface 33a of the protrusion 33 formed corresponding to this. The gasket 3 and the power generator 1 are joined in a state of being tightly engaged at the recess 1b and the protrusion 33.

  Next, FIG. 9 and FIG. 10 show an example in which the manufacturing method of the present invention is applied to a method of integrating a gasket with a power generator 1 consisting only of MEA 10, wherein (A) is a cross-sectional view and (B) is a cross-sectional view. It is a top view. That is, the power generation body 1 shown in FIGS. 9 and 10 is a gas diffusion electrode in which an electrode catalyst is supported on both surfaces of an electrolyte membrane 11 and at least an electrolyte membrane contact surface of a porous body such as carbon fiber used for GDL or the like. The layer 13 is provided in a laminated state, and in this case as well, a fuel cell seal structure can be manufactured basically in the same process as described above.

  Specifically, in the gas diffusion electrode layer 13 made of a porous body constituting both sides in the thickness direction of the power generation body 1 (MEA 10), a low-viscosity or liquid state is formed in a region having a predetermined width W from the end face 1a of the power generation body 1. After impregnating part 131 is formed by impregnating a sealing material made of rubber or resin and curing by cross-linking, a large number of engagement surfaces 1c with respect to the planar extension direction of power generator 1 are provided on end surface 1a of power generator 1. The recesses 1b are formed at predetermined intervals, or conversely, a plurality of recesses 1b having engagement surfaces 1c with respect to the planar extension direction of the power generator 1 are formed at predetermined intervals on the end surface 1a of the power generator 1. The impregnated portion 131 is formed by impregnating an area of a predetermined width W from the end face 1a of the power generator 1 with a sealing material made of low-viscosity or liquid rubber or resin and curing it.

  Thus, in the impregnation part 131 formed in the peripheral part of the gas diffusion electrode layer 13, the continuous pores of the gas diffusion electrode layer 13 are filled with rubber or resin to have a structure that is sealed. In this case, the impregnation portion 131 is also formed by, for example, a method of impregnating the power generator 1 by immersing it in a liquid tank storing a liquid sealing material to a predetermined depth, or by screen printing or dispenser extrusion. A method of applying and impregnating a stopper can be employed, and therefore, the impregnation portion 21 having a certain width W can be easily formed from the end face 1a of the power generator 1.

  The recess 1b shown in FIG. 9 has a dovetail shape, and both inner side surfaces thereof are engaging surfaces 1c inclined substantially symmetrically so that the front end is narrower toward the groove shoulder side. Moreover, the recessed part 1b shown by FIG. 10 is formed in the bowl shape, Comprising: The engagement surface 1c is formed in the inner surface at the level | step difference form.

  Next, the power generator 1 in which the impregnated portion 131 and the concave portion 1b are formed by the above-described steps is set in a mold (not shown), and the impregnated portion 131 is interposed between the inner surfaces of the mold in the same manner as the molding step described above. Then, the cavity defined between the power generator 1 and the inner surface of the mold is filled with a low-viscosity or liquid molding rubber material and cured by crosslinking.

  In this molding process, the leakage of the low viscosity or liquid molding rubber material filled in the cavity is effectively blocked at the impregnation portion 131 and the close contact portion between the impregnation portion 131 and the mold inner surface. It is possible to effectively prevent the power generation region from being narrowed by the penetration or leakage of the molding rubber material into the electrode layer 13. Unlike the case where the gas diffusion electrode layer 13 is sandwiched between the inner surfaces of the mold, the restriction on the compressibility can be relaxed, and for molding into the cavity for the purpose of impregnating the gas diffusion electrode layer 13 with the rubber material for molding. There is no need to increase the filling pressure of the rubber material.

  The fuel cell sealing structure manufactured by this method includes a power generator 1 composed of only the MEA 10 composed of the electrolyte membrane 11 and the gas diffusion electrode layers 13 and 13 on both sides thereof, and an end face 1a facing in the plane extension direction. The gasket 3 is made of a rubber-like elastic material that is integrally molded. The gasket 3 has a base 31 formed in the recess 1b formed in the power generator 1 and the above-described molding process. A part of the molding rubber material flows in and is joined to the gas diffusion electrode layer 13 in a state in which a large number of projections 33 formed by crosslinking and curing are firmly engaged.

FIG. 2 shows a part of a power generation body that implements the method for manufacturing a fuel cell seal structure according to the present invention, in which (A) is a sectional view and (B) is a plan view. In the manufacturing method of this invention, the state which formed the impregnation part in GDL of an electric power generation body is shown, (A) is sectional drawing, (B) is a top view. In the manufacturing method of this invention, the impregnation part is formed in GDL and the state which formed the recessed part in the end surface of an electric power generation body is shown, (A) is sectional drawing, (B) is a top view. It is explanatory drawing which shows the process of shape | molding a gasket in the manufacturing method of this invention. 1 shows a fuel cell seal structure manufactured according to the present invention, in which (A) is a sectional view and (B) is a plan view. It is sectional drawing which shows the sealing structure for fuel cells manufactured by this invention in relation to the separator for fuel cells. As another embodiment of the present invention, a state in which a concave portion is formed on the end face of the power generation body before the formation of the impregnation portion in the GDL is shown, (A) is a cross-sectional view, and (B) is a plan view. In the manufacturing method of this invention, the other shape example of the recessed part formed in the end surface of an electric power generation body is shown, (A) is sectional drawing, (B) is a top view. The example which applied the manufacturing method of this invention to the method of integrating a gasket with the electric power generation body which consists of MEA is shown, (A) is sectional drawing, (B) is a top view. The other example which applied the manufacturing method of this invention to the method of integrating a gasket with the electric power generation body which consists of MEA is shown, (A) is sectional drawing, (B) is a top view. It is sectional drawing which shows an example of the conventional sealing structure for fuel cells. It is sectional drawing which shows the other example of the conventional sealing structure for fuel cells.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric power generation body 1a End surface 1b Recessed part 1c Engagement surface 10 MEA
11 Electrolyte membrane 12 Electrode layer 13 Gas diffusion electrode layer (porous body)
20 GDL (porous material)
21, 131 Impregnated portion 3 Gasket 31 Base portion 32 Seal lip 33 Projection portion 33a Engaged surface 4 Mold 41 Upper die 42 Lower die 43 Cavity 44 Gate

Claims (2)

In the production of a fuel cell seal structure in which a gasket (3) is integrally provided along an end surface (1a) facing the planar extension direction of a power generator (1) of a fuel cell,
Of the porous body (20, 13) constituting both side portions in the thickness direction of the power generation body (1), a region having a predetermined width (W) from the end face (1a) is made of a low-viscosity or liquid rubber or resin. Forming an impregnated portion (21, 131) by impregnating a sealing material to be crosslinked and curing;
Then, forming a recess (1b) having an engagement surface (1c) in the planar extension direction on the end surface (1a) of the power generation body (1) at a predetermined interval;
The power generation body (1) is set in the mold (4), and the inner surface of the mold (4) is brought into close contact with the impregnation portion (21, 131), and the end surface (1a) and the mold (4) Filling a rubber material for molding into a cavity (43) defined between the inner surface and the cross-linking and curing;
The manufacturing method of the sealing structure for fuel cells characterized by the above-mentioned. In the production of a fuel cell seal structure in which a gasket (3) is integrally provided along an end surface (1a) facing the planar extension direction of a power generator (1) of a fuel cell,
Forming recesses (1b) having engagement surfaces (1c) in the planar extension direction on the end surface (1a) of the power generation body (1) at predetermined intervals;
Thereafter, in the porous body (20, 13) constituting the both sides in the thickness direction of the power generation body (1), a low-viscosity or liquid rubber or a region having a predetermined width (W) from the end face (1a) A step of forming an impregnated portion (21, 131) by impregnating a sealing material made of resin and curing by crosslinking;
The power generation body (1) is set in the mold (4), and the inner surface of the mold (4) is brought into close contact with the impregnation portion (21, 131), and the end surface (1a) and the mold (4) Filling a rubber material for molding into a cavity (43) defined between the inner surface and the cross-linking and curing;
The manufacturing method of the sealing structure for fuel cells characterized by the above-mentioned.

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