JP2009099423A - Gasket member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasket member of which a handling property is improved. <P>SOLUTION: Since a seal lip is composed of an elastic body capable of exhibiting a sealing function by being deformed by pressing from a pair of separators, in the gasket member, gas sealing property between the pair of the separators can be secured, and further, since the gasket member has a shape reinforcing part composed of a material having a higher rigidity than that of the seal lip, deformation of the gasket member (twist, breakage or the like) is suppressed and the handling property is improved. Moreover, like this, by means that the deformation is suppressed, a membrane electrode assembly positioned at the inner peripheral side of the gasket member is prevented from being broken and damaged in handling the gasket member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gasket member, and relates to a gasket member with improved handling properties.

  In general, a unit cell of a polymer electrolyte fuel cell is composed of a membrane electrode assembly (MEA) and separators stacked on both sides of the membrane electrode assembly (MEA).

  The membrane electrode assembly is composed of an electrolyte membrane made of a solid polymer electrolyte membrane such as Nafion (registered trademark: manufactured by DuPont), a catalyst layer and a gas diffusion layer disposed on one surface of the electrolyte membrane, and an oxidant gas ( For example, a fuel electrode (for example, hydrogen gas) that includes an air electrode (cathode electrode) to which air is supplied and a catalyst layer and a gas diffusion layer disposed on the other surface of the electrolyte membrane (for example, hydrogen gas) is supplied. Anode electrode).

  When the separator is hermetically molded from a conductive material and laminated with the membrane electrode assembly interposed therebetween, an air chamber is formed on the air electrode side of the membrane electrode assembly, and the fuel chamber is formed on the fuel electrode side. Form. When the fuel cell stack is configured, the separators are common to adjacent unit cells.

  One of the structures for ensuring the gas sealing property between a pair of separators is a gasket member disposed on the outer peripheral side of the membrane electrode assembly. For example, Patent Document 1 discloses a gasket (seal structure) that is integrally held on the outer peripheral side of a membrane electrode assembly and seals between a pair of separators, and is entirely composed of a rubber-like elastic body. Is described.

The gasket described in Patent Document 1 is integrally formed with a seal lip that is in close contact with the inner surface of the separator and exhibits a sealing function. The fastening load applied to the seal lip is lower than the load applied to the membrane electrode assembly. Therefore, a rubber-like elastic body having a low hardness has been adopted.
JP 2006-228590 A

  However, since the gasket described in Patent Document 1 is made of a rubber-like elastic body having a low hardness, the gasket is likely to be deformed (for example, twisted or broken) during handling. Since the membrane electrode assembly is integrated with such a gasket, there is a possibility that the membrane electrode assembly may be broken or damaged by twisting or breaking of the gasket. Therefore, although satisfying the requirement of lowering the fastening load applied to the seal lip relative to the load applied to the membrane electrode assembly, the gasket that is likely to be deformed has a problem of poor handling.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a gasket member having improved handling properties.

  In order to achieve this object, the gasket member according to claim 1 includes a membrane electrode assembly having a solid polymer electrolyte membrane and a pair of electrode layers laminated on both surfaces of the solid polymer electrolyte membrane, and the membrane. Used in a fuel cell including a pair of separators provided on both surfaces of an electrode assembly and having a gas flow path for supplying gas to each electrode layer, and disposed between the membrane electrode assembly and the pair of separators. The seal lip is made of an elastic body that can be deformed by pressing from the pair of separators and can exhibit a sealing function, and a material that is more rigid than the seal lip. And a shape reinforcing portion.

  The gasket member according to claim 2 is the gasket member according to claim 1, wherein the shape reinforcing portion is provided on at least one of the inner peripheral side and the outer peripheral side of the seal lip, and is more rigid than the seal lip. It is the shoulder part comprised from the elastic body.

  A gasket member according to a third aspect is the gasket member according to the first aspect, wherein the shape reinforcing portion is a linear member made of a material having a higher rigidity than the seal lip embedded therein.

  A gasket member according to a fourth aspect is the gasket member according to any one of the first to third aspects, wherein the shape reinforcing portion is disposed so as to surround at least the outer peripheral side of the seal lip.

  According to the gasket member of the first aspect, since the seal lip is formed of an elastic body that can be deformed by pressing from the pair of separators and exhibit a sealing function, the gas sealing performance between the pair of separators can be secured. In addition, since the shape reinforcing portion made of a material having higher rigidity than that of the seal lip is provided, deformation (twisting, folding, etc.) of the gasket member is suppressed and the handling property is improved.

  According to the gasket member of the second aspect, in addition to the effect produced by the gasket member according to the first aspect, the following effect is obtained. On at least one side of the inner peripheral side or the outer peripheral side of the seal lip, a shoulder portion made of an elastic body having higher rigidity than the seal lip is provided, and the shoulder portion functions as a shape reinforcing portion.

  Therefore, the shoulder portion is made of an elastic body having higher rigidity than the seal lip, and a function as a shape reinforcing portion that increases the rigidity of the gasket member can be added to the original function as the shoulder portion. Accordingly, there is no need to separately provide a shape reinforcing portion, and there is an effect that the handling property can be improved while suppressing the complexity of the configuration of the gasket member.

  According to the gasket member of claim 3, in addition to the effect of the gasket member of claim 1, the following effect is obtained. Since the linear member made of a material having higher rigidity than the seal lip is embedded inside as the shape reinforcing portion, the deformation of the gasket member can be suppressed, and as a result, the handling property can be improved. is there. Here, since the linear member which is a shape reinforcement part is embed | buried inside, the component of a linear member is hard to elute outside. Therefore, the handling property can be improved without increasing the risk of deterioration of the membrane electrode assembly due to the elution component from the linear member.

  According to the gasket member of Claim 4, in addition to the effect which the gasket member in any one of Claim 1 to 3 exhibits, there exists the following effect. Since the shape reinforcing portion is disposed so as to surround at least the outer peripheral side of the seal lip, the rigidity of the gasket member is effectively increased, and deformation such as twisting or breaking of the gasket member can be effectively suppressed. Therefore, there is an effect that the handling property of the gasket member can be greatly improved.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view showing a part of a fuel cell stack 100 in which a plurality of unit cells 10 of a fuel cell are stacked.

  As shown in FIG. 1, the fuel cell stack 100 has a structure in which a number of gasket members 40 in which membrane electrode assemblies 20 are integrated on the inner peripheral side and metal separators 60 are alternately stacked (in FIG. 1, Only three gasket members 40 and three metal separators 60 are shown). End plates (not shown) are arranged at both ends of the fuel cell stack 100 in the stacking direction, and both end plates are fastened using bolts (not shown) and nuts (not shown). By doing so, the gasket member 20 and the metal separator 60 which are laminated | stacked alternately are press-clamped.

  Here, the unit cell 10 of the fuel cell includes a membrane electrode assembly 20, a gasket member 40 disposed on the outer peripheral side of the membrane electrode assembly 20, and metal separators positioned on both sides of the membrane electrode assembly 20. 60. As shown in FIG. 1, one metal separator 60 is commonly used as a separator for adjacent unit cells 10.

  The membrane electrode assembly 20 includes a solid polymer electrolyte membrane 21 (see FIG. 2 (c)) such as Nafion (registered trademark: manufactured by DuPont) or Aciplex (registered trademark: manufactured by Asahi Kasei Co., Ltd.), and the solid polymer. It is comprised from a pair of electrode layers 22 and 23 (refer FIG.2 (c)) each laminated | stacked and joined on both surfaces of the electrolyte membrane.

  Both electrode layers 22 and 23 in the membrane electrode assembly 20 are each composed of a catalyst layer (not shown) and a gas diffusion layer (not shown), and the catalyst layer side is joined to the solid polymer electrolyte membrane. ing. These electrode layers are used as an air electrode (cathode electrode) or a fuel electrode (anode electrode) depending on the type of gas supplied. Hereinafter, the electrode layer 22 will be described as the air electrode 22, and the electrode layer 23 will be described as the fuel electrode 23.

  A gas diffusion layer (not shown) in the air electrode 22 and the fuel electrode 23 is composed of carbon woven fabric, carbon paper, or the like capable of gas diffusion. For example, carbon cloth, carbon paper, carbon fiber A nonwoven fabric made of or the like is used.

  In addition, as the catalyst layer (not shown) in the membrane electrode assembly 20, for example, a layer including carbon carrying a platinum catalyst and an electrolyte can be employed.

  Next, the gasket member 40 of this embodiment is demonstrated with reference to FIGS. 2A is a perspective view schematically showing one surface side of the gasket member 40 in which the membrane electrode assembly 20 is integrated on the inner peripheral side, and FIG. 2B is a perspective view of FIG. FIG. 2C is a perspective view schematically showing the back surface side of the gasket member 40 shown in FIG. 2, and FIG. 2C is a cross-sectional view taken along the line IIc-IIc in FIG. 2A and 2C, the detailed structure of the seal structures 45 and 51 is omitted for the purpose of facilitating understanding of the drawings.

  3 (a) is a front view of the portion viewed from the direction of arrow IIIa in FIG. 2 (a), and FIG. 3 (b) is a cross-sectional view taken along line IIIb-IIIb in FIG. 3 (a). 3 (c) is a front view of a portion viewed from the direction of arrow IIIc in FIG. 2 (a). For the purpose of facilitating understanding of the drawing, hatching is applied to the shoulder portions 45b and 45c in FIG. 3A and to the shoulder portions 51b and 51c in FIG. 3C. FIG. 4 is an enlarged cross-sectional view schematically showing the seal structures 45 and 51.

  The gasket member 40 is a member that is disposed on the outer peripheral side of the membrane electrode assembly 20 and ensures a gas sealing property between a pair of metal separators 60 that are disposed to face both surfaces thereof. The gasket member 40 includes an air electrode gasket 41 constituting one surface of the gasket member 40 and a fuel electrode gasket 42 constituting the other surface.

  The air electrode gasket 41 and the fuel electrode gasket 42 are made of an insulating elastic body such as rubber or resin. Although details will be described later, each of the air electrode gasket 41 and the fuel electrode gasket 42 is composed of two types of insulating elastic bodies having different hardness (or rigidity). Such an air electrode gasket 41 and a fuel electrode gasket 42 are produced by injection molding one type of insulating elastic body into a corresponding shape and then injection molding the other type of insulating elastic body into the corresponding shape. be able to.

  Here, an adhesive film sheet (not shown) is disposed on one side of each gasket 41, 42 (the side to be bonded to each other), and these gaskets 41 are opposed to each other. , 42 are bonded together to produce the gasket member 40. The air electrode gasket 41 and the fuel electrode gasket 42 have openings 41a and 42a corresponding to the membrane electrode assembly 20, respectively. When the gasket member 40 is manufactured, the air electrode gasket 41 and the fuel electrode gasket 42 After the membrane electrode assembly 20 is interposed between the two, they are bonded. Therefore, the membrane electrode assembly 20 is fixed by the adhesive film sheet (not shown), and as a result, the gasket member 40 is obtained as the membrane electrode assembly 20 integrated on the inner peripheral side thereof.

  The gasket member 40 has openings 43 and 44 on both ends sandwiching the membrane electrode assembly 20. These openings 43 and 44 serve as flow paths through which fuel gas (for example, hydrogen gas) flows in the stacking direction of the fuel cell stack 100 (the arrow Z direction in FIG. 2A or the opposite direction). is there.

  In order to prevent fuel gas from leaking from the openings 43 and 44 to the air electrode 22 and the outside, a seal structure 45 is formed around the openings 43 and 44 in the air electrode gasket 41 of the gasket member 40. ing.

  The seal structure 45 includes a seal lip portion 45a, shoulder portions 45b and 45c positioned on both sides of the seal lip portion 45a in cross-sectional view (that is, the inner peripheral side and the outer peripheral side of the seal lip 45a), and the seal lip portion 45a. 45d formed between the shoulder portion 45b and the groove portion 45e formed between the seal lip portion 45a and the shoulder portion 45c.

  The seal lip portion 45 a is a portion that exerts a gas seal function by being deformed by being pressed from the metal separator 60 facing when the fuel cell stack 100 is configured (stacking). Shoulder portions 45b and 45c, together with shoulder portions 51b and 51c, which will be described later, are portions that define the distance between the pair of metal separators 60 when the fuel cell stack 100 is configured (during lamination). The groove portions 45d and 45e are portions that function as escape portions of the insulating elastic body for allowing deformation of the seal lip portion 45a due to a compressive load.

  More specifically, the seal lip portion 45a has a sharp tapered tip such as a cross-sectional mountain shape or a triangular shape as shown in FIG. 4 in order to satisfy the demand for long-term durability of the gas seal function. At the same time, the height is configured to be higher than the height of the shoulder portions 45b and 45c (that is, the tip portion is positioned higher than the shoulder portions 45b and 45c).

  Further, the seal lip portion 45a has a low hardness (for example, a hardness of about 40 to 50 degrees) due to the necessity of lowering the fastening load applied to the seal lip portion 45a with respect to the load applied to the membrane electrode assembly 20. It is composed of an elastic body.

  Further, the shoulder portions 45b and 45c are required to control the seal lip portion 45a to a desired compression rate (that is, to control the seal lip portion 45a to a desired height with respect to the compression load). Therefore, a shape with little or no deformation against a compressive load is employed. Examples of the shape with little or no deformation with respect to the compressive load include a shape having a flat tip (such as a trapezoidal cross section or a square cross section) as shown in FIG. Further, the heights of the shoulder portions 45b and 45c are configured to be lower than the seal lip portion 45a and substantially the same height so that the seal lip portion 45a can be controlled to a desired compression rate. Yes.

  In the gasket member 40 of the present embodiment, the shoulder portion 45b and the shoulder portion 45c are made of an insulating elastic body that is higher in rigidity (or higher hardness) than the seal lip portion 45a and hardly elastically deforms. By configuring the shoulder portions 45b and 45c from an insulating elastic body having higher rigidity than the seal lip portion 45a, the rigidity of the gasket portion 40 can be increased, so that it can be handled during handling (for example, when the gasket portion 40 is lifted). Etc.) can be made difficult to deform. Therefore, the handling property of the gasket part 40 of this embodiment can be improved.

  Further, the air electrode gasket 41 in the gasket member 40 is formed with an open recess 46 on the opposite two end sides 46a, 46b side. The concave portion 46 accommodates the air electrode side collector 63 (see FIG. 5A) when the metal separator 60 is laminated, and the air as the oxidant gas flows on the air electrode 22 in the direction indicated by the arrow X (or the opposite direction). ) Is formed. The bottom surface portion of the recess 46 is made of an insulating elastic body having the same low hardness as the seal lip portion 45a.

  On the other hand, a seal structure 51 is formed on the outer periphery of the fuel electrode gasket 42 in the gasket member 40. The seal structure 51 prevents fuel gas from leaking from the fuel cell stack 100 (or unit cell 10) to the outside.

  Similar to the seal structure 45 described above, the seal structure 51 includes a seal lip portion 51a and shoulder portions located on both sides of the seal lip portion 51a in cross-sectional view (that is, the inner peripheral side and the outer peripheral side of the seal lip 45a). 51b, 51c, a groove 51d formed between the seal lip 51a and the shoulder 51b, and a groove 51e formed between the seal lip 51a and the shoulder 51c.

  Similar to the seal lip 45a, the seal lip portion 51a is deformed by being pressed from the metal separator 60 facing when the fuel cell stack 100 is configured (stacked), and has a gas seal function by being in close contact with the metal separator 60. It is a part to be exhibited, and has a sharp tapered tip, and is configured such that its height is higher than the height of the shoulders 51b and 51c. Similarly to the seal lip 45a, the seal lip portion 51a is also composed of an insulating elastic body having a low hardness due to the necessity of lowering the fastening load applied to the seal lip portion 51a with respect to the load applied to the membrane electrode assembly 20. ing.

  The shoulder portions 51b and 51c, together with the above-described shoulder portions 45b and 45c, are portions that define the distance between the pair of metal separators 60, and have a shape with a flat tip (such as a trapezoidal cross section or a square cross section). In addition, the height is lower than the height of the seal lip portion 51a, and the height is substantially the same. The shoulder portions 51b and 51c are also made of an insulating elastic body that is higher in rigidity (or higher hardness) than the seal lip portion 51a and hardly elastically deforms so that the rigidity of the gasket portion 40 can be increased.

  Moreover, the groove parts 51d and 51e are parts which function as escape parts of the insulating elastic body for allowing deformation of the seal lip part 51a due to a compressive load, like the groove parts 45d and 45e described above.

  A recess 52 is formed in the fuel electrode gasket 42 of the gasket member 40. The recess 52 accommodates the fuel electrode side collector 62 (see FIG. 5A) when the metal separators 60 are stacked, and the fuel gas (for example, hydrogen) moves on the fuel electrode 23 in the arrow Y direction (or vice versa). A fuel chamber that circulates in the direction) is formed. The bottom surface portion of the recess 52 is made of an insulating elastic body having the same low hardness as the seal lip 51a.

  Next, the metal separator 60 of this embodiment will be described with reference to FIG. FIG. 5A is a perspective view schematically showing one side of the metal separator 60, and FIG. 5B is a perspective view schematically showing the back side of the metal separator 60 shown in FIG. 5A. FIG.5 (c) is sectional drawing in the Vc-Vc line | wire of Fig.5 (a).

  The metal separator 60 includes a plate-shaped separator main body 61, a fuel electrode side collector 62 provided on one surface of the separator 61, and an air electrode side collector 63 provided on the other surface of the separator 61.

  The separator body 61 functions as a gas blocking member between the adjacent unit cells 10 and is made of a conductive thin plate, and corresponds to the openings 43 and 44 of the gasket member 40 (that is, when stacked). Openings 61a and 61b serving as fuel gas flow paths are opened at positions communicating with the openings 43 and 44). As the conductive thin plate constituting the separator main body 61, for example, a thin plate obtained by subjecting a stainless steel, nickel alloy, titanium alloy or the like to a corrosion-resistant conductive treatment such as gold plating can be used.

  The fuel electrode side collector 62 is a current collector that is accommodated in the recess 52a (see FIG. 2) of the gasket member 40 and collects current generated by electrode reaction by contacting the fuel electrode 23 side of the membrane electrode assembly 20. is there.

  The fuel electrode side collector 62 is erected at the same height from one surface side of the separator body 61, and has a plurality of conductive ribs 62a extending between the opening 61a and the opening 61b, and these ribs 62a. And a current collecting member 62b which is a conductive plate material (for example, a metal plate material such as an expanded metal or a punching metal) having a large number of openings disposed at the front end thereof. A space 62c surrounded by the rib 62a adjacent to the separator body 61 and the current collecting member 62a functions as a fuel gas flow path.

  On the other hand, the air electrode side collector 63 is housed in the recess 46 (see FIG. 2) of the gasket member 40 and contacts the air electrode 22 side of the membrane electrode assembly 20 to collect current generated by the electrode reaction. It is an electric body.

  The air electrode side collector 63 is erected at the same height from the other surface side of the separator body 61, and has a plurality of conductive ribs 63a extending in a direction substantially perpendicular to the ribs 62a, and tips of these ribs 63a. And a current collecting member 63b, which is a conductive plate material (for example, a metal plate material such as expanded metal or punching metal) having a large number of openings. A space 63c surrounded by the rib 63a adjacent to the separator body 61 and the current collecting member 63b functions as an air flow path. Since the air electrode side collector 63 has a current collecting member 63b having a large number of openings, water generated in the air electrode 22 as a result of the electrode reaction is transmitted to the space 63c (air channel). Can do.

  As the rib 62a and the current collecting member 62b constituting the fuel electrode side collector 62 and the rib 63a and the current collecting member 63b constituting the air side collector 63, the material adopted as the separator main body 61, that is, stainless steel is used. Steel, nickel alloy, titanium alloy or the like subjected to a corrosion-resistant conductive treatment such as gold plating can be used.

  As described above, according to the first embodiment, the shoulder portions 45b and 45c provided on the air electrode gasket 41 in the gasket member 40 and the shoulder portions 51b and 51c provided on the fuel electrode gasket 42 are provided. However, since it is comprised from the highly rigid elastic body compared with other parts (seal lip parts 45a, 51, etc.), the rigidity of gasket member 40 increases. Therefore, deformation (for example, twist or breakage) of the gasket member 40 during handling can be suppressed, and handling properties of the gasket member 40 are improved (improved).

  In addition, since the deformation of the gasket member 40 is suppressed as described above, the membrane electrode assembly 20 integrated with the gasket member 40 can be prevented from being damaged or damaged when the gasket member 40 is handled. Is also effective.

  Here, according to the gasket member 40 of the present embodiment, the shoulder portions 45b, 45c, 51b, and 51c are made of an elastic body having higher rigidity (or higher hardness) than other portions, so that the pair of metal separators 60 can be formed. The function of increasing the rigidity of the gasket member 40 can be added to the original function of the shoulder for defining the interval. Therefore, it is not necessary to separately provide a member for increasing the rigidity of the gasket member 40, and the handling property can be improved while suppressing the complexity of the structure of the gasket member 40.

  In particular, since the shoulder portions 51b and 51c are disposed on the outer periphery of the gasket member 40, the rigidity of the gasket member 40 can be effectively increased. As a result, deformation (twisting or bending) of the gasket member 40 can be effectively suppressed, so that the handling performance of the gasket member 40 is greatly improved.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 6A and FIG. 6B are enlarged cross-sectional views schematically showing seal structures 450 and 510 according to the second embodiment of the present invention. In the description of the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  Whereas the shoulder portions 45b, 45c, 51b, 51c of the seal structures 45, 51 of the gasket member 40 in the first embodiment described above are composed of an insulating elastic body having higher rigidity than the seal lip portions 45a, 51a. In the seal structures 450 and 510 according to the second embodiment, the shoulder portions 450b, 450c, 510b, and 510c are made of an insulating elastic body having the same low hardness as the seal lip portions 45a and 51a.

  As shown in FIGS. 6A and 6B, in the second embodiment, metal wires W are arranged inside the seal structures 450 and 510. The wire W is provided around the seal structures 450 and 510. Thus, by arranging the wires W inside the seal structures 450 and 510, the rigidity of the gasket member 40 can be increased as in the first embodiment described above.

  In the case where the wire W is disposed inside the seal structures 450 and 510, as shown in FIG. 6B, as compared to the case where the wire W is disposed inside the seal lip portions 45a and 51a, FIG. As shown to (a), the direction which arrange | positions the wire W inside the shoulder parts 450b, 450c, 510b, 510c does not restrict | limit compression of the thickness direction of the seal lip parts 45a, 51a, and gas sealing function inhibits it. It is preferable because it is not.

  As described above, according to the second embodiment, since the wires W are disposed inside the seal structures 450 and 510, the rigidity of the gasket member 40 is increased, and the gasket member 40 is deformed during handling. (For example, twist or breakage) can be suppressed, and as a result, the handleability of the gasket member 40 is improved.

Here, as shown in FIGS. 6A and 6B, the wire W, which is a member that reinforces the rigidity of the gasket member 40, is buried in the seal structures 450 and 510. The elution component from W is difficult to elute to the outside of the gasket member 40, and the risk of deterioration of the membrane electrode assembly due to the elution component from the wire W is low. Therefore, according to the second embodiment, the handling property can be improved without increasing the risk of deterioration of the membrane electrode assembly due to the elution component from the wire W.
As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed.

  For example, in each of the above embodiments, the shoulder portions 45b, 45c, 51b, 51c configured from an elastic body having higher rigidity than the other portions and the wire W are members for increasing the rigidity of the gasket member 40. Such members are not limited to these. For example, as an adhesive film sheet (not shown) used for bonding the air electrode gasket 41 and the fuel electrode gasket 42, a sheet having rigidity that can be used as a reinforcing plate that increases the rigidity of the gasket member 40 is used. May be.

  In the second embodiment, the metal wire W is disposed inside the seal structures 450 and 510. However, instead of the metal wire W, a resin wire having higher rigidity than other portions. It is good also as a strip-shaped member (or strip-shaped member).

  Moreover, in each said embodiment, although shoulder part 45b, 45c, 51b, 51c and the wire W were used as the member for improving the rigidity of the gasket member 40, arrangement | positioning of the member for improving the rigidity of this gasket member 40 is provided. The position is not limited to these, and the gasket member 40 can be disposed at various positions. Further, the shoulder portions 45b, 45c, 51b, 51c, and the wire W are not limited to members that are continuously provided, and the members may be provided discontinuously (intermittently) or irregularly. It may be arranged in.

  When the member for increasing the rigidity of the gasket member 40 is arranged in a state where the cross sections of the seal lip portions 45a and 51a are crossed in layers, the compression of the seal lip portions 45a and 51a in the thickness direction is not limited, and the gas seal It is preferable to arrange so that the function is not inhibited. More preferably, the member that increases the rigidity of the gasket member 40 is preferably disposed without crossing the cross sections of the seal lip portions 45a and 51a in layers.

  In the first embodiment, both the shoulder portions 45b and 45c formed on the air electrode gasket 41 and the shoulder portions 51b and 51c formed on the fuel electrode gasket 42 are elastic with higher rigidity than the other portions. Although it comprised from a body, the shoulder part comprised from an elastic body higher rigidity than another part is good also as either one of shoulder part 45b, 45c or shoulder part 51b, 51c. Similarly, in the second embodiment, the seal structure in which the wire W is disposed may be one of the seal structure 450 or the seal structure 510.

  Further, of the shoulder portions 45b and 45c formed on the outer peripheral side and the inner peripheral side of the seal lip portion 45a, the shoulder portion formed of an elastic body having higher rigidity than the other portions is either the shoulder portion 45b or the shoulder portion 45c. It is good also as one side. Similarly, of the shoulder portions 51b and 51c formed on the outer peripheral side and the inner peripheral side of the seal lip portion 51a, the shoulder portion formed of an elastic body having higher rigidity than the other portions is either the shoulder portion 45b or the shoulder portion 45c. It is good also as either. Similarly, the shoulder part in which the wire W is disposed may be either the shoulder part 45b (shoulder part 51b) or the shoulder part 45c (shoulder part 51c).

1 is an exploded perspective view showing a part of a fuel cell stack in which a plurality of unit cells of a fuel cell are stacked. (A) is a perspective view which shows typically the one surface side of the gasket member by which the membrane electrode assembly is integrated by the inner peripheral side, (b) is the back surface of the gasket member shown to Fig.2 (a). It is a perspective view which shows the side typically, (c) is sectional drawing in the IIc-IIc line | wire of Fig.2 (a). (A) is the front view of the part seen from the arrow IIIa direction in Fig.2 (a), (b) is sectional drawing in the IIIb-IIIb line | wire of Fig.3 (a), (c) is It is the front view of the part seen from the arrow IIIc direction in Fig.2 (a). It is an expanded sectional view showing typically the seal structure of a 1st embodiment. (A) is a perspective view which shows typically the one surface side of a metal separator, (b) is a perspective view which shows typically the back surface side of the metal separator shown to Fig.5 (a), (c) These are sectional drawings in the Vc-Vc line of Drawing 5 (a). It is an expanded sectional view showing typically the seal structure of a 2nd embodiment.

Explanation of symbols

10 unit cell 20 membrane electrode assembly 21 solid polymer electrolyte membrane 22 air electrode (part of a pair of electrode layers)
23 Fuel electrode (part of a pair of electrode layers)
40 Gasket member 45a Seal lip (seal lip)
45b Shoulder (shape reinforcement)
45c Shoulder (shape reinforcement)
51a Seal lip (seal lip)
51b Shoulder (shape reinforcement)
51c Shoulder (shape reinforcement)
60 Metal separator (separator)
100 Fuel cell stack W Wire (shape reinforcement)

Claims (4)

A membrane electrode assembly having a solid polymer electrolyte membrane and a pair of electrode layers laminated on both sides of the solid polymer electrolyte membrane, and a gas flow supplied to each electrode layer provided on both sides of the membrane electrode assembly A gasket member that is used in a fuel cell including a pair of separators having a path, and that is disposed between the membrane electrode assembly and the pair of separators to ensure gas sealing properties,
A seal lip composed of an elastic body that can be deformed by pressing from the pair of separators and exhibit a sealing function;
And a shape reinforcing portion made of a material having higher rigidity than the seal lip.   The shape reinforcing portion is a shoulder portion that is provided on at least one of the inner peripheral side and the outer peripheral side of the seal lip, and is formed of an elastic body having higher rigidity than the seal lip. The gasket member as described.   The gasket member according to claim 1, wherein the shape reinforcing portion is a linear member made of a material having a higher rigidity than the seal lip embedded therein. The gasket member according to any one of claims 1 to 3, wherein the shape reinforcing portion is disposed so as to surround at least an outer peripheral side of the seal lip.

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