Fuel cell gaskets

Abstract

To provide a gasket which suppresses deformation and extension of a bead caused by a compressive load to the gasket, with a relatively simple configuration, which does not cause deterioration in sealing properties. and which is also capable of eliminating the need for laser welding itself or reducing welding points of laser welding.SOLUTION: A gasket 1 includes a first separator 2 having a first bead 7, and a second separator 3 superposed on the first separator 2 and having a second bead 13 formed in a position opposite to the first bead 7. The first separator 2 further has a first protrusion 8 disposed close to the first bead 7 and protruding from a first separator front surface 2a in the same direction as the protruding direction of the first bead 7, and the second separator 3 further has a second protrusion 14 disposed close to the second bead 13, protruding from a second separator rear surface 3b in a direction opposite to the protruding direction of the second bead 13, and fittable to the first protrusion 8.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gasket for a fuel cell, and more particularly to a separator-integrated gasket for a fuel cell that is integrally formed with a separator. [Background technology]

[0002] Many fuel cells (fuel cell stacks) have been developed for use primarily in fuel cell vehicles, etc. Such fuel cell stacks mainly comprise a stack body formed by stacking a plurality of unit cells, and a housing body that houses the stack body.

[0003] Furthermore, the main components of a unit cell are an electrolyte membrane, electrodes, gas diffusion layers, separators, and gaskets (sealing materials), and electricity is generated by a reaction between a fuel gas such as hydrogen supplied from the anode side and an oxidizing gas such as air supplied from the cathode side. Separator-integrated fuel cell gaskets, in which the separator and gasket are integrated, are also known.

[0004] The separators, which form part of the unit cells, form fluid flow paths that allow the flow of gases (fluids) consisting of fuel gases such as hydrogen and oxidizing gases such as air, etc. The gaskets also form a sealed structure that prevents these fluids from leaking from the fluid flow paths to the outside.

[0005] The separators are made by pressing flat metal plates into a predetermined shape, forming ridge-like beads that protrude from the plate surface. A pair of separators, one on the anode side and one on the cathode side, are then stacked together to form a fluid flow path surrounded by the opposing beads. Utilizing the reaction force of the protrusions makes it possible to maintain a high level of sealing (sealing performance) to prevent fluid leakage (see, for example, Patent Document 1).

[0006] More specifically, as shown in FIG. 11, a conventional fuel cell gasket 100 includes an anode-side separator 102 and a cathode-side separator 103, each having a bead 101 formed thereon, and is configured by stacking the anode-side separator 102 and the cathode-side separator 103 on top of each other.

[0007] In this case, the beads 101 of the cathode side separator 103 are disposed at positions facing the beads 101 of the anode side separator 102, and are formed with their protruding directions opposite to each other. That is, by combining a pair of beads 101, a fluid flow path FC having a substantially hexagonal cross section is formed, as shown in Fig. 11. In addition, the bead connecting portions 104 of the beads 101 are covered with elastic rubber portions 105, allowing the fuel cell gasket 100 to maintain even higher sealing performance.

[0008] In the case of the gasket 100 for the fuel cell, for example, when a force is applied in a direction (corresponding to the vertical direction of the paper in FIG. 12, load directions F1 and F2) that compresses the gasket 100 for the fuel cell (particularly the unit cell), the beads 101 tend to expand in a direction (expansion directions D1 and D2) perpendicular to the compressive direction. As a result, the spring characteristics of the beads 101 decrease, and the reaction force of the beads 101 becomes insufficient. become Therefore, there is a possibility that the sealing property may be impaired.

[0009] Therefore, a laser joint 106 is provided between the anode side separator 102 and the cathode side separator 103 by laser welding or the like to suppress deformation of the bead 101 due to compression (see the pair of arrows on the left and right in Figure 13), thereby achieving stable sealing properties (see Figure 13). [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2020-198200 Summary of the Invention [Problem to be solved by the invention]

[0011] However, if a joining step of laser welding the anode side separator and the cathode side separator as described above is required in manufacturing a fuel cell stack, there is a risk that the number of manufacturing steps will increase and the working time for the welding work will increase.

[0012] In particular, for each unit cell, laser welding must be performed at multiple locations to prevent such deformation, which can lead to problems in the manufacture of fuel cell stacks, such as reduced work efficiency and increased manufacturing costs.

[0013] In view of the above circumstances, an object of the present invention is to provide a gasket for fuel cells that has a relatively simple structure, suppresses deformation and expansion of the beads due to a compressive load on the gasket for fuel cells, and exhibits sufficient spring characteristics so as not to cause a decrease in sealing performance. In particular, an object of the present invention is to provide a gasket for fuel cells that suppresses an increase in the number of manufacturing steps such as laser welding and an increase in the welding work time, and that does not require laser welding itself, or that reduces the number of welded parts by laser welding, thereby reducing work time and manufacturing costs. [Means for solving the problem]

[0014] According to the present invention, a gasket for a fuel cell that solves the above problems is provided as follows.

[0015] [1] A separator includes a first separator having a first bead, and a second separator overlapping the first separator and having a second bead formed at a position opposite to the first bead, wherein the first separator further has a first convex portion disposed adjacent to the first bead and projecting from the surface of the first separator in the same direction as the projecting direction of the first bead, and the second separator further has a second convex portion disposed adjacent to the second bead and projecting from the back surface of the second separator in the opposite direction to the projecting direction of the second bead, and capable of engaging with the first convex portion. Two or more of the second protrusions are fitted to one of the first protrusions. Gasket for fuel cells.

[0016] [2] A gasket for a fuel cell as described in [1], wherein the height of the first convex portion from the surface of the first separator is set to be equal to or less than the height of the first bead from the surface of the first separator.

[0017] [3] The gasket for a fuel cell according to [1] or [2], wherein the first convex portion is disposed at a position at least within 10 mm from the bead center position of the first bead.

[0018] [4] A gasket for a fuel cell according to [1], wherein the first convex portion and the second convex portion are arranged at predetermined intervals along the longitudinal direction of the first bead and the second bead.

[0019] [5] A gasket for a fuel cell according to [1], wherein the first convex portion and the second convex portion have a cross-sectional tapered shape that is protruded from the surface of the first separator or the back surface of the second separator at an angle relative to the vertical direction.

[0020] [6] The gasket for a fuel cell described in [1], wherein when the first convex portion and the second convex portion are fitted together, a first fitting gap is set between the back surface of the first convex portion and the surface of the second convex portion along the bead longitudinal direction of the first bead and the second bead, and a second fitting gap is set between the back surface of the first convex portion and the surface of the second convex portion along the bead perpendicular direction perpendicular to the bead longitudinal direction, the second fitting gap being equal to or smaller than the first fitting gap.

[0021] [7] The gasket for a fuel cell according to [1], wherein the first separator and the second separator are made of metal plates made of stainless steel or titanium.

[0022] [8] A gasket for a fuel cell as described in [1], further comprising a laser joining portion provided in a position close to the first convex portion and the second convex portion, or the first bead and the second bead, and joining the first separator and the second separator, which are stacked on top of each other, by laser welding.

[0023] [9] The gasket for a fuel cell according to [1], wherein the first convex portion and the second convex portion are formed to have at least one of a rectangular cross-section, a circular cross-section, and an elliptical cross-section when viewed from above.

[0025] [1 0 ] The gasket for a fuel cell described in [1], wherein the first separator is arranged adjacent to the first bead and further has a first recess recessed from the surface of the first separator in the opposite direction to the protruding direction of the first bead, and the second separator is arranged adjacent to the second bead and further has a second recess recessed from the back surface of the second separator in the same direction as the protruding direction of the second bead and capable of fitting with the first recess. [Effects of the Invention]

[0026] The gasket for fuel cells of the present invention has a first convex portion of the first separator and a second convex portion of the second separator that are close to the first bead and the second bead and can fit together, thereby restricting the movement of the first separator and the second separator when they are stacked together, and even when a load is applied in a direction that compresses the gasket for fuel cells, the expansion of the first bead and the second bead is suppressed, thereby maintaining stable sealing properties.

[0027] In addition, the joining work by laser welding of the first separator and the second separator to suppress the spreading of the first bead and the second bead can be omitted or the number of joining points can be reduced. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is an explanatory diagram showing a schematic configuration of a gasket for a fuel cell according to one embodiment of the present invention. [Figure 2] 1 is a cross-sectional front view showing a schematic configuration of a gasket for a fuel cell according to an embodiment of the present invention. [Figure 3] 1 is a plan view showing a schematic configuration of a gasket for a fuel cell according to an embodiment of the present invention, as viewed from above. [Figure 4] 4 is a cross-sectional view taken along line AA' in FIG. 3, showing the first fitting gap. FIG. [Figure 5] 4 is a cross-sectional view taken along line BB' in FIG. 3, illustrating a second fitting gap. FIG. [Figure 6] 10 is an explanatory top view showing the cross-sectional shapes of the first and second convex portions of a gasket for a fuel cell according to another embodiment of the present invention; FIG. [Figure 7] FIG. 10 is an explanatory top view showing the position of a laser-bonded portion of a gasket for a fuel cell according to another embodiment of the present invention (2). [Figure 8] 10 is an explanatory top view showing the fitted state of the first and second protrusions of a gasket for a fuel cell according to another embodiment of the present invention (3). FIG. [Figure 9] FIG. 10 is an explanatory top view showing the positions of the first and second convex portions and the laser-bonded portions of a gasket for a fuel cell according to another embodiment of the present invention (4). [Figure 10] FIG. 10 is an explanatory view showing the positions of the first recess and the second recess of a gasket for a fuel cell according to another embodiment of the present invention (5). [Figure 11] FIG. 10 is an explanatory diagram showing a schematic configuration of a conventional gasket for a fuel cell. [Figure 12] 10 is an explanatory diagram showing deformation of a bead due to a compressive load in a conventional gasket for a fuel cell. [Figure 13] FIG. 10 is an explanatory diagram showing the position of a laser-bonded portion of a conventional gasket for a fuel cell. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, an embodiment of the gasket for a fuel cell of the present invention will be described with reference to the drawings. Note that the gasket for a fuel cell of the present invention is not limited to the following, and various design changes, modifications, improvements, etc. can be made without departing from the gist of the present invention.

[0030] 1. Fuel cell gaskets A gasket 1 for a fuel cell (hereinafter simply referred to as "gasket 1") according to one embodiment of the present invention is configured as part of a unit cell (not shown) of a fuel cell stack, as shown primarily in Figures 1 to 5, and is configured to include a first separator 2, a second separator 3, and elastic rubber parts 4 attached to the first separator 2 and the second separator 3, respectively.

[0031] The first separator 2 is formed by press-molding a flat metal plate P and bending it into a predetermined shape. When taken along the longitudinal direction of the metal plate P (corresponding to the horizontal direction in FIG. 2 ), the first separator 2 has a pair of inclined first bead legs 5 a, 5 b bent obliquely upward from the first separator surface 2 a, a first bead connecting portion 6 connecting one ends of the pair of first bead legs 5 a, 5 b and extending parallel to the first separator surface 2 a, a first bead 7 formed with a convex cross section (see FIG. 2 ), and a first convex portion 8 disposed adjacent to the first bead 7 and projecting from the first separator surface 2 a in the same direction as the protruding direction of the first bead 7.

[0032] Furthermore, in the gasket 1 of this embodiment, the elastic rubber portion 4 is attached by a well-known method so as to cover the surface of the first bead connecting portion 6 of the first bead 7. Here, the metal plate P can be made of various metals, such as a stainless steel plate or a titanium plate.

[0033] To explain the first convex portion 8 in more detail, similar to the first bead 7 described above, the first convex portion 8 has a pair of first convex inclined portions 9 that are bent obliquely upward from the first separator surface 2a, and a first convex connecting portion 10 that connects one ends of the first convex inclined portions 9 and is parallel to the first separator surface 2a, and is formed into a convex cross-sectional shape.

[0034] At this time, the convex portion height H1 (see FIG. 2), which indicates the height from the first separator surface 2a to the first convex portion connecting portion 10 of the first convex portion 8, is set to be equal to or smaller than the bead height H2 (see FIG. 2), which indicates the height from the first separator surface 2a to the first bead connecting portion 6 of the first bead 7. In other words, the height H1 is set to satisfy the relationship "bead height H2≧convex portion height H1."

[0035] Furthermore, the first convex portion 8 is set so that the first convex portion inclined portion 9 or the first convex portion connecting portion 10 is located at a position close to and within at least 10 mm from the bead center position C (see FIG. 2) of the first bead 7. In other words, the distances L1 and L2 (see FIG. 2) from the bead center position C to the first convex portion 8 are set to at least 10 mm.

[0036] In this way, the convex portion height H1 of the first convex portion 8 is determined based on the bead height H2 of the first bead 7, and the first convex portion 8 is arranged within the range of distances L1 and L2 close to the first bead 7.

[0037] On the other hand, the second separator 3, like the first separator 2, is formed by press-forming a flat metal plate P and bending it into a predetermined shape, and has a pair of second bead legs 11a, 11b bent obliquely downward from the second separator surface 3a when taken along the plate longitudinal direction of the metal plate P (corresponding to the horizontal direction in FIG. 2 ), a second bead connecting portion 12 connecting one end of the pair of second bead legs 11a, 11b and extending parallel to the second separator surface 3a, a second bead 13 formed with an inverted convex cross section (see FIG. 2 ), and a second convex portion 14 disposed adjacent to the second bead and protruding from the second separator back surface 3b in the direction opposite to the protruding direction of the second bead 13. Also, like the first separator 2, an elastic rubber portion 4 is attached to cover the surface of the second bead connecting portion 12 of the second bead 13.

[0038] Here, the second beads 13 of the second separator 3 are disposed at positions opposite to the second beads 13 of the first separator 2 that is overlaid on the second separator 3, and are projected in a different direction from the first beads 7. In other words, they are formed symmetrically with respect to the longitudinal direction of the metal plate P.

[0039] To explain the second convex portion 14 in more detail, it has a pair of second convex portion inclined portions 15 that are bent diagonally upward from the second separator back surface 3b and inclined, and a second convex portion connecting portion 16 that connects one end of the second convex portion inclined portions 15 and is parallel along the second separator back surface 3b, and is formed into a convex cross-sectional shape.

[0040] At this time, the convex height (not shown) of the second convex portion 14 from the back surface 3b of the second separator and the distance (not shown) from the first bead 7 and the second bead 13 are determined by the convex height H1 and distances L1 and L2 of the first convex portion 8 to be fitted.

[0041] With the above configuration, by stacking the first separator 2 and the second separator 3 on top of each other, a fluid flow path FC is formed, which is a space with an approximately hexagonal cross section surrounded by the first beads 7 and the second beads 13 that are respectively protruded in different directions (see Figure 2), and it becomes possible to circulate various fluids (gases) such as fuel gases such as hydrogen and oxidizing gases such as air through the fluid flow path FC.

[0042] At this time, when the first separator 2 and the second separator 3 are overlapped with each other, the second convex portion 14 is fitted into the first convex portion 8 of the first separator 2. That is, at least a part of the first separator back surface 2b side of the first convex portion 8 and the second separator back surface 3b side of the second convex portion 14 are in contact with each other (see FIGS. 1 and 2).

[0043] As a result, the gasket 1 is compressed in the direction (the up-down direction on the paper in FIGS. 1 and 2). equivalent ) (see FIG. 12 ), the engagement between the first convex portion 8 and the second convex portion 14 can suppress deformation of the first bead 7 of the first separator 2 and the second bead 13 of the second separator 3 that would otherwise tend to expand along the longitudinal direction of the plates. As a result, the gasket 1 can maintain stable sealing performance by utilizing the reaction forces of the first bead 7 and the second bead 13.

[0044] In particular, as described above, by arranging the first convex portion 8 within a range of 10 mm adjacent to the first bead 7 and setting the convex portion height H1 of the first convex portion 8 to be at least the same as or less than the bead height H2 of the first bead 7, the above-mentioned sealing property can be made more reliably stable.

[0045] In addition, the gasket 1 of this embodiment has a plurality of first protrusions 8 and second protrusions 14 that can fit therewith, which are arranged at predetermined intervals along the bead longitudinal direction X of the first bead 7 and the second bead 13 (see Figure 1, corresponding to the direction from the front to the back of the paper in Figure 2).

[0046] In this way, by disposing a plurality of first protrusions 8 etc. discontinuously at predetermined intervals along the bead longitudinal direction X, the first beads 7 etc. are less likely to deform even when a load is applied in a direction that compresses the gasket 1. Note that, as with the first beads 7 etc., the first protrusions 8 etc. may be formed continuously along the bead longitudinal direction as long as sufficient bead characteristics are obtained.

[0047] Furthermore, as described above, the first convex portion 8 and the second convex portion 14 of the gasket 1 of this embodiment each have a first convex portion inclined portion 9 that is bent diagonally upward from the first separator surface 2a and folded, and a second convex portion inclined portion 15 that is bent diagonally upward from the second separator back surface 3b and folded, respectively.

[0048] In other words, the width between the upper ends of the first convex inclined portion 9 (or the second convex inclined portion 15) (corresponding to the length of the first convex connecting portion 10 or the second convex connecting portion 16) is formed to be shorter than the width between the lower ends of the first convex inclined portion 9 (or the second convex inclined portion 15).

[0049] As a result, the first convex portions 8 and the second convex portions 14 are formed so as to have a tapered cross section in a square or side view. More specifically, the first convex portions 8 are provided so as to protrude from the first separator front surface 2a on which they are protruding or the second separator back surface 3b on which they are protruding, and are inclined relative to the vertical direction. By configuring the first convex portions 8 etc. to have a tapered cross section in this way, deformation can be suppressed when the first separator 2 and the second separator 3 are overlapped and the first convex portions 8 and second convex portions 14 are fitted together and when compressed.

[0050] Furthermore, in the gasket 1 of this embodiment, the first and second protrusions 8 and 14 are fitted together such that, in relation to a first fitting gap a (see FIG. 5) between the back surface of the first protrusion 8 (the first separator back surface 2b side) and the front surface of the second protrusion 14 (the second separator back surface 3b side) along the bead longitudinal direction X of the first beads 7 and second beads 13, the second fitting gap b (see FIG. 4) between the back surface of the first protrusion 8 and the front surface of the second protrusion 14 along the bead-orthogonal direction Y perpendicular to the bead longitudinal direction X is set to be equal to or smaller than the first fitting gap a. In other words, the first fitting gap a and second fitting gap b are set to satisfy the relationship: "first fitting gap a≧second fitting gap b."

[0051] In order to suppress deformation of the first bead 7 and the like that expands in the horizontal direction, the second fitting gap b is set to be as small as possible, thereby making it possible to more reliably suppress deformation of the first bead 7 and the like. On the other hand, since deformation in the bead longitudinal direction X is not that large, the first fitting gap a may be relatively large.

[0052] As described above, the gasket 1 of this embodiment has a first convex portion 8 provided in a position close to the first bead 7 of the first separator 2, and a second convex portion 14 provided on the second separator 3 so as to fit into the first convex portion 8, thereby reliably suppressing deformation of the first bead 7 and the like when the first separator 2 and the second separator 3 are stacked together.

[0053] 2. Gasket with Alternative Configuration (Gasket for Fuel Cells) The gasket of the present invention is not limited to the above configuration, and may have various forms, for example, as shown below. Note that in the gaskets of the following alternative configurations, components having the same configuration as the gasket 1 of the present embodiment described above are given the same numbers, and detailed explanations thereof will be omitted below.

[0054] 2.1 Gasket of Alternative Configuration (1) As shown in FIG. 6, the gasket 20 of the alternative configuration (1) is configured to have a first convex portion 21 having a rectangular (approximately rectangular) cross section when viewed from above, a second convex portion 22a having a circular cross section when viewed from above, and a second convex portion 22b having an elliptical cross section when viewed from above.

[0055] That is, the shape of the second convex portion is not particularly limited as long as it can be fitted into the first convex portion 21, and it is not necessary for the first convex portion 8 and the second convex portion 14 to have similar shapes as shown in the gasket 1 of this embodiment. Note that, while the second convex portions 22a, 22b have a circular or elliptical cross section in comparison with the first convex portion 21 having a rectangular cross section, the first convex portion 21 may also be changed to a circular cross section or the like.

[0056] Even when the first convex portion 21 and the second convex portions 22a, 22b have different shapes, as in the gasket 20 of the alternative configuration (1), the effect of sufficiently suppressing deformation of the first bead 7 can be achieved, and work processes such as laser welding can be omitted.

[0057] 2.2 Gasket 30 of Alternative Configuration (2) As shown in FIG. 7, the gasket 30 of the alternative configuration (2) is configured with a laser-bonded portion 33 located adjacent to a first convex portion 31 and a second convex portion 32 having a circular cross section that is fitted with the first convex portion 31, more specifically, on the opposite side facing the first bead 7.

[0058] That is, by utilizing a conventionally known technique for joining separators, the first separator 2 and the second separator (not shown) can be firmly joined, and deformation of the first bead 7 can be more reliably suppressed. Although the laser welding and other work steps cannot be omitted, the effect of fitting the first protrusion 31 and the second protrusion 32 together can significantly reduce the number of joining locations where the laser joining portions 33 are provided, compared to the conventional method. This has the effect of shortening the work time and reducing the manufacturing cost.

[0059] 2.3 Gasket of Alternative Configuration (3) 8, the gasket 40 of the modified configuration (3) has two second convex portions 42a, 42b each having a circular cross section fitted to one first convex portion 41 having a rectangular cross section. Furthermore, the gasket 40 is provided with the laser-bonded portion 43 shown in the modified configuration (2) at a position close to the first convex portion 41.

[0060] That is, two or more second protrusions 42a, 42b may be fitted to one first protrusion 41. This makes it possible to more reliably fit the first protrusion 41 to the second protrusions 42a, 42b, and more effectively suppress deformation of the first bead 7.

[0061] 2.4 Gasket of Alternative Configuration (4) 9, the gasket 50 of the modified configuration (4) is configured to include a laser-bonded portion 53 at a position close to the first bead 7, more specifically, at a position facing the first convex portion 51 and the second convex portion 52. That is, a fitting portion consisting of the first convex portion 51 and the second convex portion 52 is provided on one side of the first bead 7 (the right side of the paper in FIG. 9), and the laser-bonded portion 53 is provided on the other side, so that the first bead 7 is sandwiched between the first convex portion 51, the second convex portion 52, and the laser-bonded portion 53.

[0062] That is, by combining the fitting of the first convex portion 51 and the second convex portion 52 with the laser-bonded portion 53, deformation of the first bead 7 can be suppressed.

[0063] 2.5 Gasket of Alternative Configuration (5) As shown in FIG. 10, the gasket 60 of the alternative configuration (5) is mainly composed of a first separator 61, a second separator 62, and an elastic rubber portion 63 attached to the first separator 61 and the second separator 62, and the first separator 61 is provided with the first convex portion 64 already shown, and the second separator 62 is provided with the second convex portion 65 already shown.

[0064] Furthermore, the first separator 61 has a first recess 67 that is disposed at a predetermined distance from the first protrusion 64 along the bead longitudinal direction X and in close proximity to the first bead 66, and is recessed from the first separator surface 61a in a direction different from the protruding direction of the first bead 66.

[0065] On the other hand, the second separator 62 is disposed adjacent to the second bead 68, recessed from the back surface 62a of the second separator in the same direction as the protruding direction of the second bead 68, and has a second recess 69 that can fit into the first recess 67.

[0066] That is, the gasket 60 of the modified configuration (5) has a first recess 67 that is protruded (recessed) in the opposite direction to the protruding direction of the first protrusion 64 and the second protrusion 65, which are the configurations already described, and a second recess 69 that can fit into the first recess 67. Note that the configurations and effects of the first recess 67 and the second recess 69 are substantially the same except for the protruding (recessed) direction, so a description thereof will be omitted here.

[0067] In addition to the effect of the engagement between the first convex portion 64 and the second convex portion 65, the gasket 60 of alternative configuration (5) also has the effect of the engagement between the first recess 67 and the second recess 69, and therefore can further suppress deformation of the first bead 66.

[0068] As described above, although the gaskets 20, 30, 40, 50, and 60 of the alternative configurations (1) to (5) of the present invention have some structural differences from the gasket 1 of the present embodiment already shown, they have similar basic structures, and can suppress the expansion and deformation of the first bead 7 and the like in response to a compressive load on the gasket 20 and the like, thereby maintaining stable sealing properties.

[0069] Therefore, by selecting an appropriate gasket 1 etc. depending on the magnitude of the compressive load applied to the first bead 7 etc. when the first separator 2 and the second separator 3 are stacked, it is possible to efficiently and reliably suppress deformation of the first bead 7 etc. In other words, the gasket 1 of this embodiment and the gaskets 20, 30, 40, 50, and 60 shown as alternative configurations can be suitably used as gaskets for fuel cells. [Industrial Applicability]

[0070] The gasket for a fuel cell of the present invention can be suitably used in the manufacture of fuel cells used in fuel cell vehicles and the like. [Explanation of symbols]

[0071] 1, 20, 30, 40, 50, 60, 100: Gaskets (fuel cell gaskets) 2,61: First separator 2a, 61a: first separator surface 2b: Back side of first separator 3,62: Second separator 3a: Second separator surface 3b, 62a: rear surface of second separator 4, 63, 105: Elastic rubber part 5a, 5b: First bead leg 6: First bead connection part 7,66: First bead 8, 21, 31, 41, 51, 64: First convex part 9: First convex inclined portion 10: First convex part connection part 11a, 11b: Second bead leg 12: Second bead connection part 13,68: Second bead 14, 22a, 22b, 32, 42a, 42b, 52, 65: Second convex part 15: Second convex inclined portion 16: Second protruding part connecting part 33, 43, 53, 106: Laser welding 67: First recess 69: Second recess 101: Bead 102: Anode side separator 103: Cathode side separator 104: Bead connection part C: Bead center position D1, D2: Expansion direction F1, F2: Load direction FC: Fluid flow path H1: Height of the convex part H2: Bead height L1,L2: distance P: Metal plate

Claims

1. a first separator having a first bead; a second separator overlapping the first separator and having a second bead formed at a position opposite to the first bead; The first separator is disposed adjacent to the first bead, a first protrusion protruding from the surface of the first separator in the same direction as the protruding direction of the first bead; The second separator is disposed adjacent to the second bead, a second protrusion provided on the rear surface of the second separator in a direction opposite to the protruding direction of the second bead and capable of fitting with the first protrusion, A gasket for a fuel cell in which two or more of the second protrusions are fitted to one of the first protrusions.

2. The height of the first convex portion from the surface of the first separator is 2. The gasket for a fuel cell according to claim 1, wherein the height of the first bead from the surface of the first separator is set to be equal to or less than the height of the first bead.

3. The first convex portion is 3. The gasket for a fuel cell according to claim 1, wherein the first bead is disposed at a position within 10 mm from the center of the first bead.

4. The first convex portion and the second convex portion are 2. The gasket for a fuel cell according to claim 1, wherein a plurality of the first beads and the second beads are arranged at predetermined intervals along the longitudinal direction of the first beads and the second beads.

5. The first convex portion and the second convex portion are 2. The gasket for a fuel cell according to claim 1, wherein the gasket has a tapered cross section projecting from the front surface of the first separator or the rear surface of the second separator at an angle relative to the vertical direction.

6. The first protrusion and the second protrusion in a state where they are fitted together are a first fitting gap between the rear surface of the first convex portion and the front surface of the second convex portion along the bead longitudinal direction of the first bead and the second bead, 2. A gasket for a fuel cell as described in claim 1, wherein a second fitting gap between the back surface of the first convex portion and the front surface of the second convex portion along a bead-orthogonal direction perpendicular to the bead longitudinal direction is set to be equal to or smaller than the first fitting gap.

7. The first separator and the second separator are 2. The gasket for a fuel cell according to claim 1, which is made of a metal plate made of stainless steel or titanium.

8. provided at a position close to the first convex portion and the second convex portion, or the first bead and the second bead, 2. The gasket for a fuel cell according to claim 1, further comprising a laser joint formed by joining the first separator and the second separator, which are stacked together, by laser welding.

9. The first convex portion and the second convex portion are 2. The gasket for a fuel cell according to claim 1, which is formed to have at least one of a rectangular cross section, a circular cross section, and an elliptical cross section when viewed from above.

10. The first separator is disposed adjacent to the first bead, a first recess formed in a surface of the first separator in a direction opposite to a protruding direction of the first bead; The second separator is disposed adjacent to the second bead, 2. The gasket for a fuel cell according to claim 1, further comprising a second recess recessed from the rear surface of the second separator in the same direction as the protruding direction of the second bead, the second recess being engageable with the first recess.

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