Separator for fuel cell and method for manufacturing power generation single cell laminate

Abstract

The present invention relates to a separator for a fuel cell and a method for manufacturing a power generation single cell laminate. The separator (28) for a fuel cell forms a laminated monomer (E) of the power generation single cell laminate (12). The separator (28) is formed of a joined body of a first bipolar plate (46) and a second bipolar plate (48) that are laminated, and a positioning portion (58) is provided. The positioning portion (58) is provided at positions that overlap in the lamination direction with respect to the first bipolar plate (46) and the second bipolar plate (48), respectively. The position of a first positioning edge portion (46c) of the first bipolar plate (46) is different from the position of a second positioning edge portion (48c) of the second bipolar plate (48) in the separator surface direction.

Description

Technical Field

[0001] The present invention relates to a separator for a fuel cell and a method for manufacturing a power generation single cell laminate. Background Art

[0002] Generally, a fuel cell is used in the form of a fuel cell stack. The fuel cell stack includes a power generation single cell laminate and end plates. The power generation single cell laminate is formed by laminating a plurality of power generation single cells (fuel cell monomers), and the end plates are disposed on both ends in the lamination direction of the power generation single cell laminate. A power generation single cell is constituted by sandwiching an electrolyte membrane-electrode structure with a pair of separators. In such a fuel cell stack, an internal manifold is sometimes formed. In the internal manifold, a fluid such as a reaction gas is supplied to each electrolyte membrane-electrode structure of the power generation single cell laminate. In this case, in order to ensure the fluid tightness well, it is necessary to laminate the laminated monomers of the power generation single cell laminate in a state of high-precision positioning.

[0003] Therefore, as disclosed in Patent Document 1, for example, positioning holes are considered to be provided in the laminated monomers. The positioning holes of the plurality of laminated monomers are made to coincide with each other in the lamination direction. Thereby, the laminated monomers are arranged to be positioned at a predetermined lamination position with respect to each other. By providing the positioning holes in this way, for example, an assembling device in which positioning pins are protrudingly provided on a base plate can be used to easily position the laminated monomers with respect to each other. That is, the positioning pins are inserted through the positioning holes, and while causing the inner peripheral surface of the positioning hole to follow the outer peripheral surface of the positioning pin, a plurality of laminated monomers are laminated on the base plate. Thereby, the positioning holes are made to coincide with each other in the lamination direction, and thus a plurality of laminated monomers can be laminated in a mutually positioned state.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-196849 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, sometimes the separator is constituted by a joined body formed by laminating and joining a first bipolar plate and a second bipolar plate in the lamination direction. In this case, the positioning holes provided in the separator are through holes that penetrate the first bipolar plate and the second bipolar plate integrally in the lamination direction. Therefore, both the edge portion of the positioning hole of the first bipolar plate and the edge portion of the positioning hole of the second bipolar plate are laminated to form the inner peripheral surface of the positioning hole.

[0009] As described above, in a case where, for example, stacked single units each provided with a positioning hole are stacked using a positioning pin, a frictional force is generated between the inner peripheral surface of the positioning hole and the outer peripheral surface of the positioning pin. In this case, when the inner peripheral surface of the positioning hole is formed by both a first bipolar plate and a second bipolar plate, the above-described frictional force tends to increase. In the case where the above frictional force is large, there is a concern that the stacked single unit may be deformed. In a power generation single cell stack, it is necessary to maintain adjacent separators in an electrically insulated state.

[0010] In view of the above, it is desirable to be able to easily position the stacked single units with respect to each other and to suppress deformation of the separators.

[0011] An object of the present invention is to solve the above problems.

[0012] Means for Solving the Problems

[0013] One aspect of the present invention relates to a separator for a fuel cell, which overlaps with an electrolyte membrane-electrode structure body in which electrodes are disposed on both sides of an electrolyte membrane to form a stacked single unit. In the separator for the fuel cell, a plurality of the stacked single units are stacked in a stacking direction to form a power generation single cell stack. The separator is a joined body of a stacked first bipolar plate and a second bipolar plate. A positioning portion is provided in the separator so that the positioning portions of the plurality of separators overlap each other in the stacking direction to position the stacked single units with respect to each other. The positioning portion is provided at a position that overlaps in the stacking direction with respect to each of the first bipolar plate and the second bipolar plate. The edge portion of the positioning portion of the first bipolar plate, i.e., the first positioning edge portion, and the edge portion of the positioning portion of the second bipolar plate, i.e., the second positioning edge portion, are different from each other in the position in the separator surface direction.

[0014] Other aspects of the present invention relate to a method for manufacturing a power generation single cell laminate, in which a plurality of laminate monomers are laminated in the lamination direction to obtain a power generation single cell laminate. The laminate monomer is formed by overlapping a separator with an electrolyte membrane-electrode structure in which electrodes are disposed on both sides of an electrolyte membrane. In the method for manufacturing the power generation single cell laminate, the separator has a positioning portion, and by overlapping the positioning portions in the lamination direction, the laminate monomers are positioned relative to each other. The method for manufacturing the power generation single cell laminate includes a laminate monomer formation step of forming the laminate monomer from the separator and the electrolyte membrane-electrode structure, and a lamination step of laminating a plurality of the laminate monomers on the mounting table while causing the positioning portions of the laminate monomers to overlap in the lamination direction along a guide rod protruding from the mounting table in the lamination direction. The separator is formed of a joined body of a first bipolar plate and a second bipolar plate, the positioning portion is provided at a position overlapping in the lamination direction with respect to the first bipolar plate and the second bipolar plate, respectively, and a position of a first positioning edge portion, which is an edge portion of the positioning portion of the first bipolar plate, and a position of a second positioning edge portion, which is an edge portion of the positioning portion of the second bipolar plate, are different in the separator surface direction.

[0015] A positioning portion is provided on the separator, and the positioning portions are overlapped in the lamination direction to position the laminate monomers relative to each other. For example, while causing the positioning portions to follow the guide rod, a plurality of laminate monomers are laminated, whereby the positioning portions can be overlapped with each other in the lamination direction. As a result, a plurality of laminate monomers can be easily laminated in a state where they are positioned relative to each other.

[0016] In addition, the separator is formed of a joined body of a first bipolar plate and a second bipolar plate. The positioning portion of the separator has a first positioning edge portion, which is an edge portion of the positioning portion of the first bipolar plate, and a second positioning edge portion, which is an edge portion of the positioning portion of the second bipolar plate. The relative positions of the first positioning edge portion and the second positioning edge portion are different in the separator surface direction. Therefore, as described above, when a plurality of laminate monomers are laminated in a state where they are positioned relative to each other, it is possible to prevent both the first positioning edge portion and the second positioning edge portion from following the guide rod. That is, the contact area between the positioning portion and the guide rod can be reduced. As a result, the frictional force generated between the positioning portion and the guide rod can be reduced, and deformation of the separator can be suppressed.

[0017] Effects of the Invention

[0018] Therefore, according to the present invention, the laminate monomers can be easily positioned relative to each other, and deformation of the separator can be suppressed.

[0019] The following embodiments will be described with reference to the drawings. Based on the description of the embodiments, the above objects, features, and advantages can be easily understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a perspective view of a fuel cell stack according to this embodiment.

[0021] Figure 2 This is an exploded perspective view of a power generation single cell having a separator for a fuel cell according to this embodiment.

[0022] Figure 3 This is an explanatory view of the MEA side of the first bipolar plate in the separator.

[0023] Figure 4A This is Figure 3 an enlarged view of the first positioning portion of

[0024] Figure 4B This is Figure 3 an enlarged view of the second positioning portion of

[0025] Figure 4C This is Figure 3 an enlarged view of the third positioning portion of

[0026] Figure 5 This is Figure 4C a perspective explanatory view of the third positioning portion of

[0027] Figure 6 This is a schematic top view of a manufacturing apparatus for manufacturing a power generation single cell laminate of a fuel cell stack.

[0028] Figure 7 This is Figure 6 a schematic cross-sectional view taken along the arrow direction of line VII-VII of

[0029] Figure 8 This is an explanatory view of bringing the pressing portion closer to the Figure 7 mounting table of

[0030] Figure 9 This is an explanatory view of bringing the pressing portion even closer to the Figure 8 mounting table of

[0031] Figure 10A This is an explanatory view of an embodiment in which laminate monomers with a second positioning edge protruding more than the first positioning edge are laminated. Figure 6 A cross-sectional view taken along the arrow direction of line XA-XA of

[0032] Figure 10B This is an explanatory view of an embodiment in which laminate monomers with a first positioning edge protruding more than the second positioning edge are laminated. Specific Embodiments

[0033] In the following figures, the same reference numerals may be sometimes assigned to the same or structurally equivalent elements that perform the same functions and effects, and repeated explanations may be omitted.

[0034] Figure 1 The fuel cell stack 16 equipped with the separator 28 for a fuel cell according to the present embodiment shown in Figure 2 ) can be mounted and used, for example, in a fuel cell vehicle such as a fuel cell electric vehicle (not shown). In addition, the fuel cell stack 16 can also be used as a stationary type. The fuel cell stack 16 includes a power generation single cell laminate 12 obtained by applying the manufacturing method of the power generation single cell laminate according to the present embodiment. In the power generation single cell laminate 12, a plurality of power generation single cells 14 are laminated in the lamination direction (arrow A direction).

[0035] At one end in the lamination direction of the power generation single cell laminate 12 (the end in the arrow A1 direction), a wiring board 18a, an insulating member 20a, and an end face plate 22a are sequentially arranged outward. In addition, at the other end in the lamination direction of the power generation single cell laminate 12 (the end in the arrow A2 direction), a wiring board 18b, an insulating member 20b, and an end face plate 22b are sequentially arranged outward.

[0036] The insulating members 20a and 20b are formed of an insulating material such as polycarbonate (PC) or phenolic resin. Moreover, it is also possible that each of the insulating members 20a and 20b is constituted by overlapping a plurality (for example, two) in the lamination direction. In addition, although not shown, it is also possible that concave portions recessed toward the side separated from the power generation single cell laminate 12 are formed on the surfaces of the insulating members 20a and 20b facing the power generation single cell laminate 12. In this case, the wiring board 18a is disposed in the concave portion of the insulating member 20a. The wiring board 18b is disposed in the concave portion of the insulating member 20b.

[0037] Linking rods 24 are arranged between the respective sides of the end face plate 22a and the respective sides of the end face plate 22b. One end of each linking rod 24 is fixed to the inner surface of the end face plate 22a by means of a bolt or the like. The other end of each linking rod 24 is fixed to the inner surface of the end face plate 22b by means of a bolt or the like. By fixing the linking rods 24 to the end face plates 22a and 22b, a compressive load (tightening load) in the lamination direction is applied to the power generation single cell laminate 12. Moreover, in the fuel cell stack 16, a casing having the end face plates 22a and 22b as end plates may be provided. In this case, the power generation single cell laminate 12 is housed in the casing.

[0038] As Figure 2As shown, the power generation single cell 14 has an MEA 26 with a resin frame and a pair of separators 28 that sandwich the MEA 26 with the resin frame. The MEA 26 with the resin frame has an electrolyte membrane - electrode structure (MEA) 30 and a frame - shaped (frame - like) resin frame member 32 that surrounds the outer periphery of the electrolyte membrane - electrode structure 30. The electrolyte membrane - electrode structure 30 has an electrolyte membrane 34, an anode electrode 36, and a cathode electrode 38. The anode electrode 36 is provided on one surface of the electrolyte membrane 34. The cathode electrode 38 is provided on the other surface of the electrolyte membrane 34.

[0039] The electrolyte membrane 34 is, for example, a solid polymer electrolyte membrane (cation exchange membrane) such as a thin film of perfluorosulfonic acid containing moisture. The electrolyte membrane 34 is sandwiched between the anode electrode 36 and the cathode electrode 38. Moreover, as the electrolyte membrane 34, in addition to fluorine - based electrolytes, HC (hydrocarbon) - based electrolytes can also be used.

[0040] The anode electrode 36 has an anode electrode catalyst layer (not shown) and an anode gas diffusion layer. The anode electrode catalyst layer is joined to one surface of the electrolyte membrane 34. The anode gas diffusion layer is laminated on the anode electrode catalyst layer. The cathode electrode 38 has a cathode electrode catalyst layer (not shown) and a cathode gas diffusion layer. The cathode electrode catalyst layer is joined to the other surface of the electrolyte membrane 34. The cathode gas diffusion layer is laminated on the cathode electrode catalyst layer.

[0041] The anode electrode catalyst layer is formed, for example, by uniformly coating porous carbon particles with a platinum alloy on the surface and an ion - conductive polymer binder on the surface of the anode gas diffusion layer. The cathode electrode catalyst layer is formed, for example, by uniformly coating porous carbon particles with a platinum alloy on the surface and an ion - conductive polymer binder on the surface of the cathode gas diffusion layer.

[0042] Each of the cathode gas diffusion layer and the anode gas diffusion layer is formed of a conductive porous sheet such as carbon paper or carbon cloth. Alternatively, a porous layer (not shown) may be provided on at least one of the interfaces between the cathode electrode catalyst layer and the cathode gas diffusion layer and between the anode electrode catalyst layer and the anode gas diffusion layer.

[0043] For example, the inner peripheral edge portion of the resin frame member 32 is joined to the outer peripheral edge portion of the electrolyte membrane - electrode structure 30. By providing the resin frame member 32 on the electrolyte membrane - electrode structure 30 in this way, the area of the electrolyte membrane 34 required to form one power generation single cell 14 can be reduced, for example. The electrolyte membrane 34 is relatively expensive. Therefore, by reducing the area of the electrolyte membrane 34 required to form one power generation single cell 14, the material cost of the electrolyte membrane - electrode structure 30 can be reduced.

[0044] The joining structure of the resin frame member 32 and the electrolyte membrane-electrode structure 30 is not limited to the above structure. As an example of the joining structure of the resin frame member 32 and the electrolyte membrane-electrode structure 30, it is possible to cite clamping the inner peripheral edge portion of the resin frame member 32 between the outer peripheral edge portions of the cathode gas diffusion layer and the anode gas diffusion layer. In this case, the inner peripheral end face of the resin frame member 32 may be close to, may be in contact with, or may overlap the outer peripheral end face of the electrolyte membrane 34.

[0045] As other examples of the joining structure of the resin frame member 32 and the electrolyte membrane-electrode structure 30, the outer peripheral edge portion of the electrolyte membrane 34 protrudes outward as compared with each of the cathode gas diffusion layer and the anode gas diffusion layer. Frame-shaped films are provided on both sides of the outer peripheral edge portion of the electrolyte membrane 34. A plurality of frame-shaped films are laminated in such a manner as to sandwich the electrolyte membrane 34. The laminated frame-shaped films are joined to each other by an adhesive or the like, thereby constituting the resin frame member 32.

[0046] As Figure 1 and Figure 2 shown, at one end portion (the end portion in the direction of arrow symbol B1) in the long side direction of each of the power generation single cell 14, the end plate 22a, and the insulators 20a and 20b, an oxidant gas inlet communication hole 40a, a cooling medium inlet communication hole 42a, and a fuel gas outlet communication hole 44b are arranged in the direction of arrow symbol C. At the other end portion (the end portion in the direction of arrow symbol B2) in the long side direction of each of the power generation single cell 14, the end plate 22a, and the insulators 20a and 20b, a fuel gas inlet communication hole 44a, a cooling medium outlet communication hole 42b, and an oxidant gas outlet communication hole 40b are arranged in the direction of arrow symbol C.

[0047] An oxidant gas (for example, an oxygen-containing gas) is supplied to the oxidant gas inlet communication hole 40a. A cooling medium (for example, at least one of pure water, ethylene glycol, and oil) is supplied to the cooling medium inlet communication hole 42a. A fuel gas (for example, a hydrogen-containing gas) is discharged from the fuel gas outlet communication hole 44b. A fuel gas is supplied to the fuel gas inlet communication hole 44a. The cooling medium is discharged from the cooling medium outlet communication hole 42b. The oxidant gas is discharged from the oxidant gas outlet communication hole 40b.

[0048] The oxidant gas inlet communication holes 40a provided in each power generation single cell 14, the end plate 22a, and the insulating members 20a and 20b in the power generation single cell laminate 12 communicate with each other in the stacking direction. That is, the oxidant gas inlet communication holes 40a penetrate the end plate 22a, the insulating members 20a and 20b, and the power generation single cell laminate 12 in the stacking direction. Similarly, the cooling medium inlet communication holes 42a, the fuel gas outlet communication holes 44b, the fuel gas inlet communication holes 44a, the cooling medium outlet communication holes 42b, and the oxidant gas outlet communication holes 40b each also penetrate the end plate 22a, the insulating members 20a and 20b, and the power generation single cell laminate 12 in the stacking direction.

[0049] In the present embodiment, in each power generation single cell 14, one oxidant gas inlet communication hole 40a, one cooling medium inlet communication hole 42a, one fuel gas outlet communication hole 44b, one fuel gas inlet communication hole 44a, one cooling medium outlet communication hole 42b, and one oxidant gas outlet communication hole 40b (hereinafter collectively referred to as "communication holes") are provided. However, the number of each communication hole provided in each power generation single cell 14 is not particularly limited, and may be single or multiple. In addition, the shape and arrangement of each communication hole are not limited to Figure 1 and Figure 2 the present embodiment described therein, and can be appropriately set according to the required specifications.

[0050] As Figure 2 shown, the separator 28 has a rectangular shape with a set of long sides and a set of short sides. A set of long sides of the separator 28 are arranged at intervals in the direction of the arrow symbol C. In the present embodiment, a set of long sides of the separator 28 are arranged parallel or substantially parallel to each other. A set of short sides of the separator 28 are arranged at intervals in the direction of the arrow symbol B. In the present embodiment, a set of short sides of the separator 28 are arranged parallel or substantially parallel to each other. The separator 28 is formed by laminating a first bipolar plate 46 and a second bipolar plate 48. The outer periphery of the first bipolar plate 46 and the outer periphery of the second bipolar plate 48 are joined together in a stacked state, for example, by welding, brazing, caulking (Japanese: かしめ), etc. Each of the first bipolar plate 46 and the second bipolar plate 48 is formed, for example, by stamping a cross-section of a thin metal plate into a corrugated shape. As an example of the thin metal plate, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, a titanium plate, or a plate having a surface treatment for corrosion prevention on its metal surface can be cited. Moreover, an insulating resin material may be provided at the outer edge of the separator 28.

[0051] The first bipolar plate 46 has a surface facing the resin-framed MEA 26, i.e., the MEA side 46a, and its back surface, i.e., the refrigerant side 46b. The second bipolar plate 48 has a surface facing the resin-framed MEA 26, i.e., the MEA side 48a, and its back surface, i.e., the refrigerant side 48b.

[0052] As Figure 3 shown, a plurality of rib portions linearly extending in the direction of arrow symbol B are provided on the MEA side 46a of the first bipolar plate 46. A linear oxidant gas flow path 50 is formed in the groove between these rib portions. Moreover, the rib portions and the oxidant gas flow path 50 may each be wavy. The oxidant gas flow path 50 is in fluid communication with the oxidant gas inlet communication hole 40a and the oxidant gas outlet communication hole 40b, thereby allowing the oxidant gas to flow in the plane direction (arrow symbols B and C directions) of the separator 28.

[0053] In addition, a metal raised seal 52a protruding toward the resin-framed MEA 26 ( Figure 2 ) is provided on the MEA side 46a of the first bipolar plate 46. For example, the first bipolar plate 46 is stamped, thereby integrally providing the metal raised seal 52a on the first bipolar plate 46. Instead of the metal raised seal 52a, a convex elastic seal formed of an elastic material such as rubber may be provided on the MEA side 46a.

[0054] A part of the metal raised seal 52a of the first bipolar plate 46 integrally surrounds the oxidant gas flow path 50, the oxidant gas inlet communication hole 40a, and the oxidant gas outlet communication hole 40b. Inside the area surrounded by the metal raised seal 52a, the oxidant gas flow path 50, the oxidant gas inlet communication hole 40a, and the oxidant gas outlet communication hole 40b communicate with each other. In addition, other parts of the metal raised seal 52a individually surround the fuel gas inlet communication hole 44a, the fuel gas outlet communication hole 44b, the cooling medium inlet communication hole 42a, and the cooling medium outlet communication hole 42b. Thus, the metal raised seal 52a prevents the fuel gas and the cooling medium from flowing into the oxidant gas flow path 50.

[0055] As Figure 2 shown, a plurality of rib portions linearly extending in the direction of arrow symbol B are provided on the MEA side 48a of the second bipolar plate 48. A linear fuel gas flow path 54 is formed in the groove between these rib portions. Moreover, the rib portions and the fuel gas flow path 54 may each be wavy. The fuel gas flow path 54 is in fluid communication with the fuel gas inlet communication hole 44a and the fuel gas outlet communication hole 44b, thereby allowing the fuel gas to flow in the plane direction (arrow symbols B and C directions) of the separator 28.

[0056] In addition, a metal raised seal 52b protruding toward the resin-framed MEA 26 is provided on the MEA side 48a of the second bipolar plate 48. For example, the second bipolar plate 48 is stamp-formed, whereby the metal raised seal 52b is integrally provided on the second bipolar plate 48. Alternatively, instead of the metal raised seal 52b, a convex elastic seal formed of an elastic material such as rubber may be provided on the MEA side 48a.

[0057] A part of the metal raised seal 52b of the second bipolar plate 48 integrally surrounds the fuel gas flow path 54, the fuel gas inlet communication hole 44a, and the fuel gas outlet communication hole 44b. Inside the area surrounded by the metal raised seal 52b, the fuel gas flow path 54, the fuel gas inlet communication hole 44a, and the fuel gas outlet communication hole 44b communicate with each other. In addition, other parts of the metal raised seal 52b individually surround the oxidant gas inlet communication hole 40a, the oxidant gas outlet communication hole 40b, the coolant inlet communication hole 42a, and each coolant outlet communication hole 42b. Thereby, the metal raised seal 52b prevents the oxidant gas and the coolant from flowing into the fuel gas flow path 54.

[0058] A coolant flow path 56 is provided between the coolant side 46b of the first bipolar plate 46 and the coolant side 48b of the second bipolar plate 48. The coolant flow path 56 is in fluid communication with the coolant inlet communication hole 42a and the coolant outlet communication hole 42b. Thereby, the coolant flow path 56 allows the coolant to flow in the plane direction (in the directions of the arrow symbols B and C) of the separator 28.

[0059] The coolant flow path 56 is formed by the back shape of the oxidant gas flow path 50 of the first bipolar plate 46 overlapping with the back shape of the fuel gas flow path 54 of the second bipolar plate 48. In addition, the periphery of the communication hole on the coolant side 46b and the periphery of the communication hole on the coolant side 48b are joined in a state of facing each other, for example, by welding, brazing, or the like.

[0060] The power generation single cell laminate 12 is formed by laminating a plurality of laminate units E ( Figure 2 ), for example. For example, one separator 28 (the first bipolar plate 46 and the second bipolar plate 48) is overlapped and joined with one resin-framed MEA 26 (the electrolyte membrane-electrode structure 30), thereby constituting each laminate unit E. In each laminate unit E, the outer edge portion of the resin frame member 32 is pre-joined to the outer edge portion 28a of the separator 28, for example, by fusion welding, bonding, or the like. Moreover, each laminate unit E is not limited to being formed by overlapping and joining one separator 28 with one resin-framed MEA 26. Each laminate unit E may be a unit that can ultimately form the power generation single cell laminate 12 when laminated in multiple layers.

[0061] A positioning portion 58 is provided on the partition plate 28 of each stacked monomer E. When a plurality of stacked monomers E are stacked, the positioning portions 58 of the respective stacked monomers E are made to coincide in the stacking direction, whereby the stacked monomers E are accurately positioned with respect to each other. In the present embodiment, the positioning portion 58 is a groove (recessed portion) formed in the outer edge portion 28a of the partition plate 28 and recessed from the outside of the partition plate 28 toward the inside.

[0062] In addition, as Figure 3 and Figures 4A - 4C shown, in the present embodiment, the positioning portion 58 has a first positioning portion 58a, a second positioning portion 58b, and a third positioning portion 58c. That is, a total of three positioning portions 58 are provided on one partition plate 28.

[0063] As Figure 3 shown, the first positioning portion 58a is provided near the end portion in the arrow symbol C1 direction of the short side disposed at the end portion in the arrow symbol B1 direction of the partition plate 28. The second positioning portion 58b is provided near the end portion in the arrow symbol C2 direction of the short side disposed at the end portion in the arrow symbol B2 direction of the partition plate 28. That is, the first positioning portion 58a and the second positioning portion 58b are disposed at diagonal positions of the partition plate 28. Further, it is also possible that, in the arrow symbol C direction, the second positioning portion 58b is disposed nearer to the end portion in the arrow symbol C2 direction of the partition plate 28 than the first positioning portion 58a. The third positioning portion 58c is provided at the center or substantially at the center of the long side disposed at the end portion in the arrow symbol C2 direction of the partition plate 28. Hereinafter, when the first positioning portion 58a, the second positioning portion 58b, and the third positioning portion 58c are not distinguished from each other, these are collectively referred to as the positioning portion 58 only.

[0064] As Figures 3 - 5 shown, the positioning portion 58 is provided on each of the first bipolar plate 46 and the second bipolar plate 48. A positioning structure is constituted by the positioning portion 58 of the first bipolar plate 46 and the positioning portion 58 of the second bipolar plate 48. The positioning portion 58 of the first bipolar plate 46 and the positioning portion 58 of the second bipolar plate 48 overlap in the stacking direction. The edge portion of the positioning portion 58 of the first bipolar plate 46 is referred to as a first positioning edge portion 46c. The edge portion of the positioning portion 58 of the second bipolar plate 48 is referred to as a second positioning edge portion 48c. The direction (arrow symbols B and C directions) perpendicular to the thickness direction of the partition plate 28 is referred to as the partition plate surface direction. The position of the first positioning edge portion 46c in the partition plate surface direction is different from the position of the second positioning edge portion 48c in the partition plate surface direction. In the present embodiment, the entire second positioning edge portion 48c protrudes more toward the outside in the partition plate surface direction (the inside of the groove of the positioning portion 58) than the first positioning edge portion 46c.

[0065] Here, as Figures 4A - 4CAs shown, the first positioning edge portion 46c of the first bipolar plate 46 has a first side 110a and a set of second sides 112a. The first side 110a of the first positioning edge portion 46c is on the inner side of the partition plate 28 with respect to the outer edge portion 28a of the partition plate 28 and extends along the extension direction of the outer edge portion 28a. The set of second sides 112a of the first positioning edge portion 46c face each other at intervals in the extension direction of the outer edge portion 28a.

[0066] Similarly, the second positioning edge portion 48c of the second bipolar plate 48 has a first side 110b and a set of second sides 112b. The first side 110b of the second positioning edge portion 48c is on the inner side of the partition plate 28 with respect to the outer edge portion 28a of the partition plate 28 and extends along the extension direction of the outer edge portion 28a. The set of second sides 112b of the second positioning edge portion 48c face each other at intervals in the extension direction of the outer edge portion 28a.

[0067] That is, as Figure 4A shown, the first side 110a of the first positioning edge portion 46c in the first positioning portion 58a is near the end in the arrow symbol B2 direction compared to the short side disposed at the end in the arrow symbol B1 direction of the partition plate 28 and extends along the extension direction of the short side (arrow symbol C direction). Similarly, the first side 110b of the second positioning edge portion 48c in the first positioning portion 58a is near the end in the arrow symbol B2 direction compared to the short side disposed at the end in the arrow symbol B1 direction of the partition plate 28 and extends along the extension direction of the short side (arrow symbol C direction).

[0068] The set of second sides 112a of the first positioning edge portion 46c in the first positioning portion 58a face each other at intervals in the arrow symbol C direction (groove width direction). Similarly, the set of second sides 112b of the second positioning edge portion 48c in the first positioning portion 58a face each other at intervals in the arrow symbol C direction (groove width direction).

[0069] As Figure 4B shown, the first side 110a of the first positioning edge portion 46c in the second positioning portion 58b is disposed at a position away from the short side disposed at the end in the arrow symbol B2 direction of the partition plate 28 in the arrow symbol B1 direction and extends along the extension direction of the short side (arrow symbol C direction). Similarly, the first side 110b of the second positioning edge portion 48c in the second positioning portion 58b is disposed at a position away from the short side disposed at the end in the arrow symbol B2 direction of the partition plate 28 in the arrow symbol B1 direction and extends along the extension direction of the short side (arrow symbol C direction).

[0070] A set of second sides 112a of the first positioning edge portion 46c in the second positioning portion 58b face each other at intervals in the direction of arrow symbol C (groove width direction). Similarly, a set of second sides 112b of the second positioning edge portion 48c in the second positioning portion 58b face each other at intervals in the direction of arrow symbol C (groove width direction).

[0071] As Figure 4C shown, the first side 110a of the first positioning edge portion 46c in the third positioning portion 58c is arranged at a position away from the long side arranged at the end portion in the direction of arrow symbol C2 of the partition plate 28 in the direction of arrow symbol C1, and along the extending direction of the long side (direction of arrow symbol B). Similarly, the first side 110b of the second positioning edge portion 48c in the third positioning portion 58c is arranged at a position away from the long side arranged at the end portion in the direction of arrow symbol C2 of the partition plate 28 in the direction of arrow symbol C1, and along the extending direction of the long side (direction of arrow symbol B).

[0072] A set of second sides 112a of the first positioning edge portion 46c in the third positioning portion 58c face each other at intervals in the direction of arrow symbol B (groove width direction). Similarly, a set of second sides 112b of the second positioning edge portion 48c in the third positioning portion 58c face each other at intervals in the direction of arrow symbol B (groove width direction).

[0073] Hereinafter, regarding the positioning portion 58, the length of each of the first sides 110a and 110b is referred to as the width, and the length of each of the second sides 112a and 112b is referred to as the depth. Moreover, the shape of the positioning portion 58 when viewed from the stacking direction is not limited to Figure 3 the rectangular shape shown, etc. The shape of the positioning portion 58 when viewed from the stacking direction can be, for example, an arc shape, or a polygon other than a rectangular shape. When the shape of the positioning portion 58 when viewed from the stacking direction is a polygon, there may also be rounded corners. In addition, the arrangement and number of the positioning portions 58 provided in the stacked single body E are not limited to Figure 3 shown. For example, various settings can be made according to the shape of at least any one of the partition plate 28 and the MEA 26 with a resin frame.

[0074] Moreover, in the present embodiment, as Figure 2As shown, in the power generation single cell 14, the outer edge portion of the resin frame member 32 overlaps with the outer edge portion 28a of the separator 28. A groove portion 32a is provided in a portion of the outer edge portion of the resin frame member 32 that faces the positioning portion 58 of the separator 28. When viewed in the stacking direction, the size of the groove portion 32a is larger than the size of the positioning portion 58. That is, the depth of the groove portion 32a is larger than the depth of the positioning portion 58. The groove width of the groove portion 32a is larger than the groove width of the positioning portion 58. Therefore, as described later, when the insertion portion 86 of the guide rod 66 is inserted through the positioning portion 58, contact between the resin frame member 32 and the insertion portion 86 can be avoided.

[0075] As Figures 4A - 5 shown, in the present embodiment, the width of the positioning portion 58 of the first bipolar plate 46 is larger than the width of the positioning portion 58 of the second bipolar plate 48. The depth of the positioning portion 58 of the first bipolar plate 46 is larger than the depth of the positioning portion 58 of the second bipolar plate 48. Therefore, the positions of the first positioning edge portion 46c and the second positioning edge portion 48c in the separator surface direction are different from each other. That is, the entire second positioning edge portion 48c protrudes more toward the outside in the separator surface direction than the entire first positioning edge portion 46c.

[0076] Specifically, compared with the first side 110a of the first positioning edge portion 46c, the first side 110b of the second positioning edge portion 48c protrudes toward the outside in the separator surface direction (inside the groove of the positioning portion 58). In addition, compared with each of the pair of second sides 112a of the first positioning edge portion 46c, each of the pair of second sides 112b of the second positioning edge portion 48c protrudes toward the outside in the separator surface direction.

[0077] However, without being particularly limited to the above, it is sufficient to arrange at least a part of the first positioning edge portion 46c and at least a part of the second positioning edge portion 48c so that their positions in the partition surface direction are different from each other. In this case, preferably, in the first positioning edge portion 46c and the second positioning edge portion 48c, at least one of a set of second sides 112a and at least one of a set of second sides 112b are different from each other in the partition surface direction. That is to say, it is preferable to satisfy at least one of the following condition A and condition B. Condition A is that the position of the second side 112a arranged at the end portion of the positioning portion 58 in the direction of arrow symbol B1 and the position of the second side 112b arranged at the end portion of the positioning portion 58 in the direction of arrow symbol B1 are different from each other in the partition surface direction. Condition B is that the position of the second side 112a arranged at the end portion of the positioning portion 58 in the direction of arrow symbol B2 and the position of the second side 112b arranged at the end portion of the positioning portion 58 in the direction of arrow symbol B2 are different from each other in the partition surface direction. In this case, the position of the first side 110a of the first positioning edge portion 46c and the position of the first side 110b of the second positioning edge portion 48c in the partition surface direction may be the same as each other or different from each other.

[0078] In this case, although not shown, for example, the width of the positioning portion 58 of the first bipolar plate 46 may be smaller than the width of the positioning portion 58 of the second bipolar plate 48. Although not shown, the depth of the positioning portion 58 of the first bipolar plate 46 and the depth of the positioning portion 58 of the second bipolar plate 48 may be the same as each other.

[0079] Alternatively, the width of the positioning portion 58 of the first bipolar plate 46 and the width of the positioning portion 58 of the second bipolar plate 48 may be the same as each other, and the depth of the positioning portion 58 of the first bipolar plate 46 and the depth of the positioning portion 58 of the second bipolar plate 48 may be the same as each other. In these cases, when viewed from the stacking direction, the positioning portion 58 of the first bipolar plate 46 and the positioning portion 58 of the second bipolar plate 48 are arranged to be offset from each other in the groove width direction with respect to the partition plate 28. As a result, only either one of a set of second sides 112a of the first positioning edge portion 46c protrudes outward in the partition surface direction compared to one of the second sides 112b of the second positioning edge portion 48c. That is to say, the other of a set of second sides 112b of the second positioning edge portion 48c protrudes outward in the partition surface direction compared to the other of a set of second sides 112a of the first positioning edge portion 46c.

[0080] Moreover, it may also be that among the first positioning edge portion 46c and the second positioning edge portion 48c, only the first side 110a and the first side 110b are different from each other in the position in the separator surface direction, and the second side 112a and the second side 112b are the same as each other in the position in the separator surface direction.

[0081] Around the positioning portion 58 of the separator 28, along the positioning portion 58, a welding portion 116 for welding the first bipolar plate 46 and the second bipolar plate 48 is provided. That is, the welding portion 116 is provided inside the separator 28 as compared with each side of the first side 110a and the second side 112a of the positioning portion 58, and is provided in a linear shape extending along the first side 110a and the second side 112a.

[0082] Hereinafter, with reference to Figures 1 - 3 , the operation of the fuel cell stack 16 including the power generation single cell laminate 12 will be briefly described. When the fuel cell stack 16 generates power, a fuel gas is supplied to the fuel gas inlet communication hole 44a. An oxidant gas is supplied to the oxidant gas inlet communication hole 40a. A cooling medium is supplied to the cooling medium inlet communication hole 42a.

[0083] As Figure 3 shown, the oxidant gas is introduced from the oxidant gas inlet communication hole 40a into the oxidant gas flow path 50. The oxidant gas introduced into the oxidant gas flow path 50 is supplied to the cathode electrode 38 of the electrolyte membrane - electrode structure 30 while moving in the direction of the arrow symbol B along the oxidant gas flow path 50. On the other hand, as Figure 2 shown, the fuel gas is introduced from the fuel gas inlet communication hole 44a into the fuel gas flow path 54. The fuel gas introduced into the fuel gas flow path 54 is supplied to the anode electrode 36 of the electrolyte membrane - electrode structure 30 while moving in the direction of the arrow symbol B along the fuel gas flow path 54.

[0084] Therefore, in each electrolyte membrane - electrode structure 30, the oxidant gas supplied to the cathode electrode 38 and the fuel gas supplied to the anode electrode 36 are consumed through an electrochemical reaction in the cathode electrode catalyst layer and the anode electrode catalyst layer. Thereby, power generation is performed.

[0085] The oxidant gas (oxidant exhaust gas) that is not consumed in the electrochemical reaction flows from the oxidant gas flow path 50 into the oxidant gas outlet communication hole 40b. The oxidant exhaust gas flowing into the oxidant gas outlet communication hole 40b flows in the direction of arrow symbol A in the oxidant gas outlet communication hole 40b and is discharged from the fuel cell stack 16. Similarly, the fuel gas (fuel exhaust gas) that is not consumed in the electrochemical reaction flows from the fuel gas flow path 54 into the fuel gas outlet communication hole 44b. The fuel exhaust gas flowing into the fuel gas outlet communication hole 44b flows in the direction of arrow symbol A in the fuel gas outlet communication hole 44b and is discharged from the fuel cell stack 16.

[0086] The cooling medium is introduced from the cooling medium inlet communication hole 42a into the cooling medium flow path 56. The cooling medium introduced into the cooling medium flow path 56 moves in the direction of arrow symbol B along the cooling medium flow path 56 while exchanging heat with the electrolyte membrane - electrode structure 30. The cooled cooling medium after heat exchange flows into the cooling medium outlet communication hole 42b. The cooling medium flowing into the cooling medium outlet communication hole 42b flows in the direction of arrow symbol A in the cooling medium outlet communication hole 42b and is discharged from the fuel cell stack 16.

[0087] Hereinafter, mainly with reference to Figures 6 - 9 , an example of the manufacturing apparatus 10 for manufacturing the power - generating single - cell laminate 12 by laminating a plurality of stacked monomers E while aligning the positioning portions 58 will be described. The manufacturing apparatus 10 can be applied, for example, to the case of obtaining the Figure 1 power - generating single - cell laminate 12 by laminating a plurality of stacked monomers E in the stacking direction indicated by arrow symbol X. In the present embodiment, the plurality of stacked monomers E are stacked upward (in the direction of arrow symbol X1). That is, the stacking direction of the stacked monomers E related to the manufacturing apparatus 10 is along the vertical direction.

[0088] In addition, in the present embodiment, Figures 6 - 9 the direction of arrow symbol X2 of the manufacturing apparatus 10 in Figures 1 - 5 corresponds to the direction of arrow symbol A1 of the separator plate 28 in Figure 10A . Therefore, as shown in

[0089] As shown in Figures 7 - 9 , the manufacturing apparatus 10 includes a mounting table 60, a pressing portion 62, a driving mechanism 64, guide rods 66, and a supporting mechanism 68. Moreover, in the Figure 6 manufacturing apparatus 10, the illustration of the pressing portion 62 and the driving mechanism 64 is omitted. In addition, inFigure 6 In the plan view of the stacked monomer E, whether the upper surface of the stacked monomer E is the partition plate 28 or not, the positioning portion 58 is illustrated for convenience. This is to illustrate the positional relationship between the positioning portion 58 and the guide rod 66.

[0090] The mounting table 60 has a mounting surface 70 for stacking the stacked monomers E in the stacking direction (the direction of the arrow symbol X). The pressing portion 62 is driven by a driving mechanism 64. Thus, the pressing portion 62 can approach the mounting table 60 along the stacking direction or separate from the mounting table 60 along the stacking direction.

[0091] On the outside of the mounting surface 70 of the mounting table 60, a guide post 72 extending in the stacking direction is protrudingly provided. In addition, an engaging portion 74 is provided on the pressing portion 62. As Figure 8 and Figure 9 shown, when the pressing portion 62 approaches the mounting table 60 to a predetermined distance, the engaging portion 74 engages with the guide post 72. In the present embodiment, the engaging portion 74 is a through hole provided in the pressing portion 62. The guide post 72 is slidably inserted through the engaging portion 74, and the engaging portion 74 engages with the guide post 72. In a state where the engaging portion 74 engages with the guide post 72, the pressing portion 62 approaches or separates from the mounting table 60, thereby guiding the pressing portion 62 in such a manner that the moving direction of the pressing portion 62 is along the stacking direction.

[0092] In addition, a pressing surface 76 and an abutting portion 78 are provided on the pressing portion 62. As Figure 8 and Figure 9 shown, when the pressing portion 62 approaches the mounting table 60, the pressing surface 76 abuts against the stacked monomer E stacked on the mounting surface 70. When the pressing portion 62 approaches the mounting table 60, the abutting portion 78 abuts against the upper surface of the guide rod 66.

[0093] The guide rod 66 protrudes from the mounting surface 70 of the mounting table 60 in the stacking direction. In addition, the guide rod 66 can relatively move in the stacking direction with respect to the mounting surface 70. Therefore, in a state where the abutting portion 78 of the pressing portion 62 abuts against the upper surface of the guide rod 66, when the pressing portion 62 is further moved closer to the mounting table 60, the guide rod 66 and the pressing portion 62 can be moved integrally at the same speed.

[0094] In the present embodiment, the guide rod 66 is in a prismatic shape extending in the stacking direction. Hereinafter, the end portion of the guide rod 66 that approaches the mounting table 60 in the extending direction is referred to as a base end portion (the end portion in the direction of the arrow symbol X2). The end portion of the guide rod 66 that is opposite to the mounting table 60 in the extending direction is referred to as a front end portion (the end portion in the direction of the arrow symbol X1). For example, the guide rod 66 is provided corresponding to the number and arrangement of the positioning portions 58 of the stacked monomer E in a state of being stacked on the mounting surface 70. Therefore, in the present embodiment, as Figure 6As shown, three guide rods 66 respectively corresponding to the first positioning portion 58a, the second positioning portion 58b, and the third positioning portion 58c of the stacked monomer E are provided on the placement table 60. These three guide rods 66 can have the same structure as each other except for their configurations relative to the placement surface 70.

[0095] As Figures 7 - 9 shown, specifically, the guide rod 66 has a main body portion 80, a narrow portion 82, and a stopper portion 84. The main body portion 80, the narrow portion 82, and the stopper portion 84 are sequentially arranged from the front end portion in the extending direction of the guide rod 66 toward the base end portion. Although not shown in the figure, the narrow portion 82 and the stopper portion 84 are integrally formed in a separable manner. In the extending direction of the main body portion 80, most of the front end portion of the main body portion 80 protrudes from the placement surface 70 in the stacking direction. The length by which the main body portion 80 protrudes from the placement surface 70 is longer than the stacking direction length of the plurality of stacked monomers E when a predetermined number of stacked monomers E constituting the power generation single cell laminate 12 are stacked on the placement surface 70.

[0096] In addition, the main body portion 80 has an insertion portion 86 and an exposed portion 88. When the stacked monomer E is stacked on the placement surface 70, the insertion portion 86 is inserted into the positioning portion 58 of the stacked monomer E. When the insertion portion 86 is inserted into the positioning portion 58, the exposed portion 88 is arranged outside the positioning portion 58 when viewed from the stacking direction. That is, the shape of the main body portion 80 when viewed from the stacking direction corresponds to the shape of the positioning portion 58 when viewed from the stacking direction. In the present embodiment, the shape of the guide rod 66 when viewed from the stacking direction is a rectangular shape. The length of the side along the width direction of the positioning portion 58 is slightly shorter than the width of the positioning portion 58. In addition, the length of the side along the depth direction of the positioning portion 58 is longer than the depth of the positioning portion 58.

[0097] In the state where the insertion portion 86 is inserted into the positioning portion 58 as described above, the stacked monomer E is stacked on the placement surface 70 while moving the positioning portion 58 along the guide rod 66. Thereby, the stacked monomer E can be guided to a predetermined stacking position on the placement surface 70. The positioning portions 58 of the plurality of stacked monomers E stacked on the placement surface 70 in this way coincide with each other in the stacking direction by means of the guide rod 66. Thereby, the plurality of stacked monomers E can be stacked in a mutually positioned state.

[0098] Although not shown, the outer dimension of the cross section of the narrow portion 82 orthogonal to the extending direction is smaller than the outer dimension of the cross section of the main body portion 80 orthogonal to the extending direction. The outer dimension of the cross section of the narrow portion 82 orthogonal to the extending direction is smaller than the outer dimension of the cross section of the stopper portion 84 orthogonal to the extending direction. Therefore, a first stepped portion 90 is formed between the main body portion 80 and the narrow portion 82. In addition, a second stepped portion 92 is formed between the narrow portion 82 and the stopper portion 84. Although in this embodiment the above-mentioned outer dimensions of the main body portion 80 and the stopper portion 84 are the same as each other, they may also be different from each other.

[0099] The base end portion of the main body portion 80, the narrow portion 82, and the stopper portion 84 can be inserted into the support hole 94. The support hole 94 is formed in the mounting table 60 along the stacking direction. The base end portion of the main body portion 80, the narrow portion 82, and the stopper portion 84 can move along the stacking direction within the support hole 94. Although not shown, the dimension of the cross section of the support hole 94 orthogonal to the extending direction is the same as the above-mentioned outer dimensions of the main body portion 80 and the stopper portion 84, or slightly larger than the above-mentioned outer dimensions of the main body portion 80 and the stopper portion 84. Therefore, the main body portion 80 and the stopper portion 84 can slide along the stacking direction within the support hole 94. Thereby, the extending direction of the guide rod 66 is maintained in a state along the stacking direction.

[0100] A hole diameter portion 96 is provided in the support hole 94. The hole diameter portion 96 is disposed between the first stepped portion 90 and the second stepped portion 92 of the guide rod 66 inserted into the support hole 94. When viewed from the extending direction of the support hole 94, the hole diameter portion 96 protrudes from the inner wall surface of the support hole 94 toward the center of the support hole 94. In addition, a through hole 96a through which the narrow portion 82 is inserted is formed at the center of the hole diameter portion 96. Although not shown, the dimension of the cross section of the through hole 96a in the direction orthogonal to the extending direction of the support hole 94 is smaller than the above-mentioned outer dimensions of the main body portion 80 and the stopper portion 84. In addition, the dimension of the cross section of the through hole 96a in the direction orthogonal to the extending direction of the support hole 94 is slightly larger than the above-mentioned outer dimension of the narrow portion 82.

[0101] The end face 96b of the front end portion of the hole diameter portion 96 faces the first stepped portion 90 with a space therebetween. An elastic member 98 is disposed between the end face 96b of the front end portion of the hole diameter portion 96 and the first stepped portion 90. In this embodiment, the elastic member 98 is a helical spring, and its expansion and contraction direction is along the stacking direction. In addition, the narrow portion 82 is inserted into the inside of the elastic member 98. The elastic member 98 elastically biases the guide rod 66 in a direction protruding from the mounting surface 70.

[0102] The end surface 96c of the base end portion of the aperture portion 96 can abut against the second step portion 92 and face the second step portion 92. As described above, the end surface 96c of the base end portion of the aperture portion 96 abuts against the second step portion 92, thereby restricting the guide rod 66 elastically urged by the elastic member 98 from further moving in the direction of protruding from the mounting surface 70 ( Figure 7 ). In addition, Figure 8 as well as Figure 9 As shown, the elastic member 98 is elastically deformed in the direction in which the elastic member 98 is compressed between the end surface 96b of the front end portion of the aperture portion 96 and the first step portion 90. As a result, the guide rod 66 can move in the direction of entering the placement surface 70. When the guide rod 66 moves in the direction of entering the placement surface 70, the second step portion 92 is separated from the end surface 96c of the base end portion of the aperture portion 96.

[0103] A support rod 100 is provided near the guide rod 66 of the mounting table 60 and protrudes in the stacking direction along the guide rod 66. The support rod 100 is fixed to the mounting table 60. A recess 102 ( Figure 6 The exposed portion 88 of the guide rod 66 is accommodated in the recess 102 in a manner that allows sliding in the stacking direction. The protruding length of the support rod 100 from the mounting surface 70 is greater than the length (in the stacking direction) of the plurality of stacked monomers E compressed on the mounting surface 70 as described later. Figure 9 ) is short. The support rod 100 and the support hole 94 of the mounting table 60 constitute a support mechanism 68. In the support mechanism 68, the guide rod 66 is supported by the support rod 100 and the support hole 94 of the mounting table 60 in a manner that allows movement in the stacking direction. As a result, the extension direction of the guide rod 66 can be maintained in a state along the stacking direction.

[0104] The following describes how to use Figures 6 - 9 The manufacturing device 10 stacks a plurality of stacking monomers E to obtain Figure 1 An example of a method for manufacturing a power generation cell stack 12. In the method for manufacturing the power generation cell stack 12, first, a stacking unit forming step is performed. In the stacking unit forming step, a separator 28 and an MEA 26 (electrolyte membrane-electrode assembly 30) with a resin frame are stacked in a positioned state to form a stacking unit E. The outer edge of the resin frame member 32 is joined to the outer edge of the separator 28 by welding or bonding.

[0105] Then, the lamination process is performed. Figure 7As shown, in the lamination process, the pressing portion 62 is moved by the drive mechanism 64 to a position separated from the mounting table 60. As a result, the contact portion 78 of the pressing portion 62 is also separated from the guide rod 66. Therefore, due to the elastic force of the elastic member 98, the guide rod 66 is disposed at a position where the second step portion 92 of the support hole 94 of the mounting table 60 abuts against the end face 96c of the hole diameter portion 96. That is, the protruding length of the main body portion 80 from the mounting surface 70 is the maximum.

[0106] In this state, a predetermined number of laminated monomers E constituting the power generation single cell laminate 12 are laminated on the mounting surface 70. Specifically, the insertion portions 86 of the plurality of guide rods 66 are respectively inserted into the plurality of positioning portions 58 of each laminated monomer E in the lamination direction. At this time, as described above, in the positioning portion 58, the second positioning edge portion 48c is disposed below the first positioning edge portion 46c ( Figure 10A ). The second positioning edge portion 48c protrudes outward in the direction of the partition surface compared to the first positioning edge portion 46c.

[0107] Moreover, while moving the positioning portion 58 along the insertion portion 86, the laminated monomer E is moved downward. Alternatively, this movement may be performed in such a manner that the laminated monomer E is dropped onto the mounting surface 70 in a state where the insertion portion 86 is inserted into the positioning portion 58.

[0108] As described above, by moving the positioning portion 58 along the insertion portion 86, the laminated monomer E is guided to the lamination position. In this way, the plurality of laminated monomers E are respectively guided to the lamination position and laminated, whereby the positioning portions 58 of the respective laminated monomers E are positioned in a state of being aligned in the lamination direction by means of the guide rods 66. That is, a predetermined number of laminated monomers E can be laminated on the mounting surface 70 while suppressing mutual positional deviation.

[0109] Then, a compression process is performed. In the compression process, the pressing portion 62 is brought close to the mounting table 60 on which a plurality of laminated monomers E are laminated in the lamination process by the drive mechanism 64. As a result, as Figure 8 shown, the pressing surface 76 of the pressing portion 62 abuts against the laminated monomer E. In addition, the contact portion 78 of the pressing portion 62 abuts against the front end portion of the guide rod 66. From this state, as Figure 9 shown, the pressing portion 62 is further brought close to the mounting table 60, whereby a plurality of laminated monomers E are compressed between the mounting surface 70 of the mounting table 60 and the pressing surface 76 of the pressing portion 62.

[0110] At this time, with the aid of the abutting portion 78, the guide rod 66 is also pressed by the pressing portion 62. Accordingly, the guide rod 66 resists the elastic force of the elastic member 98 and moves in the direction of entering the inside of the support hole 94 of the mounting table 60. That is to say, in the compression process, while moving the guide rod 66 in the same direction as the moving direction of the pressing portion 62 in a state where the insertion portion 86 is along the positioning portion 58, the plurality of stacked monomers E are compressed.

[0111] Moreover, in the compression process, the timing at which the pressing surface 76 abuts against the stacked monomer E may be the same as or earlier than the timing at which the abutting portion 78 abuts against the front end portion of the guide rod 66. For example, by adjusting the relative positions of the pressing surface 76 and the abutting portion 78 in the stacking direction, the timing at which the pressing surface 76 abuts against the stacked monomer E and the timing at which the abutting portion 78 abuts against the guide rod 66 can be adjusted. For example, by adjusting the protruding length of the main body portion 80 protruding from the mounting surface 70, the timing at which the pressing surface 76 abuts against the stacked monomer E and the timing at which the abutting portion 78 abuts against the guide rod 66 can be adjusted. Therefore, in the compression process, the relationship between the timing at which the stacked monomer E is compressed and starts to move and the timing at which the guide rod 66 starts to move can be adjusted.

[0112] Then, for example, with a fixing mechanism (not shown), the plurality of stacked monomers E are maintained as they are in the compressed state in the compression process. Thereby, the stacked monomers E can be applied with a compressive load in a positioned state to obtain the power generation single cell laminate 12.

[0113] Moreover, the magnitude of the compressive load applied to the plurality of stacked monomers E in the compression process can be set variously as needed. Alternatively, the compression process may be performed multiple times with a release process interposed therebetween. In the release process, the driving mechanism 64 moves the pressing portion 62 in the direction away from the mounting table 60 to reduce the compressive load to zero. Thereby, for example, an aging process for promoting initial creep can be performed on the plurality of stacked monomers E.

[0114] Based on the above, in the separator 28 according to the present embodiment, the positioning portion 58 is provided, and the positioning portion 58 is made to coincide in the stacking direction, whereby the stacked monomers E are positioned with respect to each other. Therefore, for example, by using the manufacturing apparatus 10 and stacking the plurality of stacked monomers E on the mounting table 60 while making the positioning portion 58 follow the guide rod 66 or the like, the positioning portions 58 can be made to coincide with each other in the stacking direction. Thereby, the plurality of stacked monomers E can be easily stacked in a mutually positioned state.

[0115] In addition, the separator 28 is formed by joining a first bipolar plate 46 and a second bipolar plate 48. In this separator 28, the position of the first positioning edge portion 46c in the separator surface direction is different from the position of the second positioning edge portion 48c in the separator surface direction. The first positioning edge portion 46c is the edge portion of the positioning portion 58 of the first bipolar plate 46. The second positioning edge portion 48c is the edge portion of the positioning portion 58 of the second bipolar plate 48. Therefore, as described above, when stacking a plurality of stacked monomers E in a mutually positioned state, it is possible to prevent both the first positioning edge portion 46c and the second positioning edge portion 48c from running along the guide rod 66. That is, the contact area between the positioning portion 58 and the guide rod 66 can be reduced. As a result, the frictional force generated between the positioning portion 58 and the guide rod 66 can be reduced, and deformation of the separator 28 can be suppressed.

[0116] Therefore, according to the separator 28 according to the present embodiment and the manufacturing method of the power generation single cell laminate 12 including the separator 28, the stacked monomers E can be easily and highly accurately positioned with respect to each other, and deformation of the separator 28 can be suppressed.

[0117] Further, in the above-described embodiment, when compressing a plurality of stacked monomers E stacked between the mounting table 60 and the pressing portion 62, the guide rod 66 is caused to run along the positioning portion 58 to maintain the relative positions of the stacked monomers E with respect to each other. Thereby, it is possible to effectively suppress the deviation of the relative positions of the stacked monomers E with respect to each other, and it is possible to compress the plurality of stacked monomers E in the stacking direction. In this way, in a state where the guide rod 66 runs along the positioning portion 58, when a compressive force is applied to the plurality of stacked monomers E, bending stress is likely to be generated around the positioning portion 58 due to friction or the like generated between the positioning portion 58 and the guide rod 66.

[0118] Even in this case, as described above, the contact area between the positioning portion 58 and the guide rod 66 can be reduced in the separator 28 according to the present embodiment. Therefore, the frictional force generated between the positioning portion 58 and the guide rod 66 can be reduced. As a result, it is possible to apply a compressive load to the plurality of stacked monomers E while suppressing the position deviation of the stacked monomers E and the deformation of the separator 28, thereby obtaining the power generation single cell laminate 12.

[0119] In the separator 28 for a fuel cell according to the above-described embodiment, it is preferable that one of the first positioning edge portion 46c and the second positioning edge portion 48c protrudes outward in the separator surface direction compared to the other, and when stacking the stacked monomers E from the bottom up, one of the first positioning edge portion 46c and the second positioning edge portion 48c is arranged lower than the other.

[0120] In the method for manufacturing the power generation single cell laminate 12 according to the above-described embodiment, it is preferable that in the separator 28 of the laminate monomer E formed in the laminate monomer forming step, one of the first positioning edge portion 46c and the second positioning edge portion 48c protrudes outward in the direction of the separator surface compared to the other, and in the laminating step, the laminate monomer E is laminated from the bottom upward in a state where one of the first positioning edge portion 46c and the second positioning edge portion 48c is arranged lower than the other.

[0121] In the present embodiment, as Figure 10A shown, the second positioning edge portion 48c protrudes outward in the direction of the separator surface compared to the first positioning edge portion 46c. Further, when laminating the laminate monomer E from the bottom upward, the second positioning edge portion 48c is arranged lower than the first positioning edge portion 46c. In this case, when laminating the laminate monomer E, a stress in the upward deformation direction may be generated in the second positioning edge portion 48c that contacts the guide rod 66 due to the frictional force with the guide rod 66.

[0122] Moreover, for example, as Figure 10B shown, it may also be that when laminating the laminate monomer E from the bottom upward, the first positioning edge portion 46c arranged above the second positioning edge portion 48c protrudes outward in the direction of the separator surface compared to the second positioning edge portion 48c. In this case, when laminating the laminate monomer E, a stress in the upward deformation direction may be generated in the first positioning edge portion 46c that contacts the guide rod 66 due to the frictional force with the guide rod 66.

[0123] In Figure 10A the embodiment, even if the above stress is generated, the first positioning edge portion 46c is also arranged above the second positioning edge portion 48c. Therefore, in Figure 10A the embodiment, for example, the deformation of the second positioning edge portion 48c can be suppressed more effectively than in Figure 10B the embodiment. Further, in Figure 10A the embodiment, a force in the direction of separating the first bipolar plate 46 from the second bipolar plate 48 can be suppressed from being applied to the welded portion 116. Therefore, in Figure 10A the embodiment, the deformation of the separator 28 can be further effectively suppressed.

[0124] However, even in Figure 10B the embodiment, the frictional force generated between the second positioning edge portion 48c and the guide rod 66 can be reduced. Therefore, in Figure 10B the embodiment, the deformation of the separator 28 can be effectively suppressed as compared with the case where frictional forces are generated between both the first positioning edge portion 46c and the second positioning edge portion 48c and the guide rod 66.

[0125] However, in an embodiment where the second positioning edge portion 48c protrudes outward in the direction away from the separator surface compared to the first positioning edge portion 46c, the outer edge portion of the second bipolar plate 48 may be cut to form the positioning portion 58. In the cutting process, the outer edge portion of the second bipolar plate 48 is cut by a cutting edge (not shown). In this case, preferably, the cutting edge moves from the lower surface of the second bipolar plate 48 toward the upper surface with respect to the second bipolar plate 48 during lamination in the lamination process. As a result, in the second positioning edge portion 48c, burrs are formed from the lower surface toward the upper surface of the second positioning edge portion 48c during lamination in the lamination process. By forming burrs in such a direction, the frictional force generated between the second positioning edge portion 48c and the guide rod 66 can be effectively reduced. Furthermore, the deformation of the separator 28 can be more effectively suppressed. Moreover, in an embodiment where the first positioning edge portion 46c protrudes outward in the direction away from the separator surface compared to the second positioning edge portion 48c, preferably, the cutting edge moves in the above-described direction with respect to the first bipolar plate 46.

[0126] In the separator 28 for a fuel cell according to the above-described embodiment, the positioning portion 58 is a groove that is formed in a part of the outer edge portion 28a of the separator 28 and recesses from the outside of the separator 28 toward the inside. In this case, the positioning portion 58 can be easily formed in the separator 28. Even if the positioning portion 58 is formed, an increase in the outer shape of the separator 28 can be avoided. With a simple structure in which the rod-shaped guide rod 66 is inserted into the groove-shaped positioning portion 58, the plurality of stacked monomers E can be easily positioned with respect to each other.

[0127] Moreover, the positioning portion 58 may be a convex portion that protrudes outward in the direction away from the separator surface from the outer edge portion 28a of the separator 28. In this case, the position of the edge portion of the convex portion of the positioning portion 58 in the first bipolar plate 46 in the direction of the separator surface may be different from the position of the edge portion of the convex portion of the positioning portion 58 in the second bipolar plate 48 in the direction of the separator surface. Alternatively, a groove (not shown) extending in the stacking direction may be formed in the guide rod 66. With the positioning portion 58 inserted into this groove, the stacked monomers E are stacked on the placement surface 70. As a result, the stacked monomers E can be guided to the stacking position. In addition, although not shown, the positioning portion 58 may be a through-hole that penetrates the separator 28 in the thickness direction.

[0128] In the separator 28 for a fuel cell according to the above-described embodiment, each of the first positioning edge portion 46c and the second positioning edge portion 48c has a set of sides (the second side 112a of the first positioning edge portion 46c and the second side 112b of the second positioning edge portion 48c) facing each other with an interval in the groove width direction of the positioning portion 58. The positions of at least one of the set of sides in the separator surface direction are different between the first positioning edge portion 46c and the second positioning edge portion 48c. The end portions in the extending directions of the second sides 112a and 112b of the positioning portion 58 are connected to the outer edge portion 28a of the separator 28. Therefore, when a frictional force is generated between the second sides 112a and 112b and the guide rod 66, the second sides 112a and 112b tend to be more easily deformed than the first sides 110a and 110b. Thus, the positions of the second side 112a of the first positioning edge portion 46c and the second side 112b of the second positioning edge portion 48c in the separator surface direction are made different. Thereby, the frictional force generated between the second sides 112a and 112b and the guide rod 66 can be reduced, and thereby the deformation of the separator 28 can be effectively suppressed with a simple structure.

[0129] In the fuel cell stack 16 according to the above-described embodiment, the separator 28 has a rectangular shape and has a set of long sides facing each other and a set of short sides facing each other. The positioning portion 58 has a first positioning portion 58a provided on one of the set of short sides of the separator 28, a second positioning portion 58b provided on the other of the set of short sides, and a third positioning portion 58c provided on either one of the set of long sides.

[0130] In addition, in the fuel cell stack 16 according to the above-described embodiment, the first positioning portion 58a and the second positioning portion 58b are arranged at diagonal positions of the separator 28, and the third positioning portion 58c is arranged at the center of the long side.

[0131] By providing the positioning portion 58 as described above, the positional deviation between the stacked monomers E can be effectively suppressed. By providing the positioning portion 58 as described above, the deformation of the separator 28 can be effectively suppressed.

[0132] Moreover, the present invention is not limited to the above-described embodiment, and various structures can be obtained without departing from the gist of the present invention.

Claims

1. A separator for a fuel cell, which overlaps with an electrolyte membrane-electrode structure (30) formed by disposing electrodes on both sides of an electrolyte membrane (34) to form a stacked monomer (E). In the separator (28) for the fuel cell, a plurality of the stacked monomers are stacked in the stacking direction to thereby form a power generation single cell stack (12), the separator is an assembly formed by mutually joining a stacked first bipolar plate (46) and a second bipolar plate (48), a positioning structure is provided in the separator, the positioning structure includes a positioning portion (58), and the positioning portion has a groove shape formed by cutting out a part of an outer edge portion (28a) of the assembly from the outside toward the inside. When a plurality of the stacked monomers are overlapped in the stacking direction, the stacked monomers are positioned relative to each other, the positioning portion is provided on the first bipolar plate and the second bipolar plate, the positioning portion of the first bipolar plate and the positioning portion of the second bipolar plate are provided at positions overlapping each other in the stacking direction, a second positioning edge portion (48c) which is an edge portion of the positioning portion of the second bipolar plate protrudes toward the inside of the groove of the positioning portion compared to a first positioning edge portion (46c) which is an edge portion of the positioning portion of the first bipolar plate, when a plurality of the stacked monomers are overlapped in the stacking direction, the second positioning edge portion is located on the traveling direction side of the stacking direction relative to the first positioning edge portion.

2. A method for manufacturing a power generation single cell stack, in which a plurality of stacked monomers (E) are stacked in the stacking direction to obtain a power generation single cell stack (12). The stacked monomer is formed by overlapping a separator (28) with an electrolyte membrane-electrode structure (30) formed by disposing electrodes on both sides of an electrolyte membrane (34). In the method for manufacturing the power generation single cell stack, the separator has a positioning structure, and the positioning structures are overlapped in the stacking direction to thereby position the stacked monomers relative to each other, the method for manufacturing the power generation single cell stack includes: a stacked monomer forming step of stacking the electrolyte membrane-electrode structure on the separator to form the stacked monomer; and a stacking step of stacking a plurality of the stacked monomers on the mounting table while causing the positioning portion of the stacked monomer to follow a guide rod (66) protruding in the stacking direction from the mounting table (60), thereby overlapping the positioning structures of the plurality of the stacked monomers in the stacking direction. The separator forming the stacked monomer in the stacked monomer forming step is formed by a joined body of a first bipolar plate (46) and a second bipolar plate (48) stacked thereon. The positioning structure has a positioning portion (58) provided on the first bipolar plate and a positioning portion (58) provided on the second bipolar plate. The positioning portion of the first bipolar plate and the positioning portion of the second bipolar plate are provided at positions overlapping each other in the stacking direction. An edge portion of the positioning portion of the first bipolar plate, i.e., a first positioning edge portion (46c), and an edge portion of the positioning portion of the second bipolar plate, i.e., a second positioning edge portion (48c), are different in position in a separator surface direction perpendicular to the thickness direction of the separator. The electrolyte membrane - electrode structure has a groove portion larger than the positioning portion when viewed from the stacking direction at a portion overlapping with the positioning portion of the separator.

3. The method for manufacturing a stacked power generation single cell according to claim 2, wherein: In the stacked monomer forming step, one of the first positioning edge portion and the second positioning edge portion of the separator forming the stacked monomer protrudes outward in the separator surface direction compared to the other. In the stacking step, the stacked monomers are stacked from bottom to top in a state where one of the first positioning edge portion and the second positioning edge portion is arranged lower than the other.

Images