JP2010118329A - Fuel cell stack and manufacturing method of metal separator for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell stack in which structural support of power generation units having a cooling medium passage formed are made securely and metal separators can be manufactured simply and economically. <P>SOLUTION: The fuel cell stack 10 is constructed of a first power generation unit 12A and a second power generation unit 12B laminated alternately along horizontally direction. In the first power generation unit 12A and the second power generation unit 12B, first metal separators 14A, 14B arranged respectively at an identical position have a shape of a first oxidant gas circulation region established mutually 180° rotated in the separator surface, while the shape of communication hole groups is established in an identical shape. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention has n (n is an even number) electrolyte / electrode structure in which a pair of electrodes are arranged on both sides of an electrolyte, and n + 1 metal separators stacked alternately with each electrolyte / electrode assembly. In addition, a reaction gas flow region for flowing a reaction gas, which is either a fuel gas or an oxidant gas, in the surface direction of the metal separator and a reaction gas communication hole for flowing the reaction gas in the stacking direction are formed. A fuel cell stack and a fuel cell metal that are alternately stacked by forming a cooling medium flow path between the first power generation unit and the second power generation unit The present invention relates to a method for manufacturing a separator.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure (MEA) in which an anode side electrode and a cathode side electrode are disposed on both sides of an electrolyte membrane made of a polymer ion exchange membrane is provided by a pair of separators. The unit cell is sandwiched. This type of fuel cell is normally used as a fuel cell stack by stacking a predetermined number of unit cells.

  In the above fuel cell, a fuel gas flow channel for flowing fuel gas is provided in the plane of one separator so as to face the anode side electrode, and the cathode side electrode is opposed in the plane of the other separator. An oxidant gas flow path for flowing an oxidant gas is provided. Further, between the separators, a coolant flow path for allowing a coolant to flow as needed is provided along the surface direction of the separator.

  At this time, when a metal separator is used as the separator, when a recess for the fuel gas flow path is provided on one surface of the anode-side metal separator, the other surface of the metal separator has a back surface shape of the recess. A convex part is formed. Further, when a concave portion for the oxidant gas flow path is provided on one surface of the cathode-side metal separator, a convex portion that is the back surface shape of the concave portion is formed on the other surface of the metal separator.

  For example, as disclosed in Patent Document 1, in a fuel cell stack in which a plurality of fuel cells each having electrodes disposed on both sides of a solid electrolyte are stacked, the fuel cells are used by being interposed between the fuel cells. One side surface is provided with a fuel gas channel groove for supplying fuel gas to one adjacent fuel cell, and the other side surface is used to supply oxidant gas to the other adjacent fuel cell. A fuel cell separator having an oxidant gas channel groove is known.

  In this separator, a metal material having excellent workability is coated on the front and back surfaces of a metal material having excellent workability, and a large number of protrusions are provided on the front and back surfaces at appropriate intervals. Further, the protrusion is provided so as to contact the surface of the fuel cell in the fuel cell stack, and the fuel gas passage groove and the oxidant gas passage groove are provided between the protrusion and the fuel cell, respectively. Is formed in communication.

JP-A-8-222237

  By the way, the fuel cell stack may adopt a so-called thinning cooling structure in which a cooling medium flow path is formed between a predetermined number of unit cells. When the above-described conventional technology is employed in a fuel cell having this type of thinning cooling structure, as shown in FIG. 30, a cell unit 3 having two MEAs 1a and 1b and three metal separators 2a, 2b and 2c. However, the fuel cell is configured by stacking a plurality of layers.

  In the MEAs 1a and 1b, an anode side electrode 4b and a cathode side electrode 4c are disposed on both sides of the solid electrolyte membrane 4a. The metal separator 2a has a plurality of convex portions 5a that form a fuel gas flow path 5 for supplying fuel gas to the anode side electrode 4b of the MEA 1a. On the other hand, the metal separator 2b supplies the fuel gas to the plurality of convex portions 6a for forming the oxidant gas flow path 6 for supplying the oxidant gas to the cathode side electrode 4c of the MEA 1a and the anode side electrode 4b of the MEA 1b. A plurality of convex portions 5a for forming the fuel gas flow path 5 are alternately provided.

  The metal separator 2c has a plurality of convex portions 6a for forming an oxidant gas flow path 6 for supplying an oxidant gas to the cathode side electrode 4c of the MEA 1b, and between the metal separators 2c and 2a adjacent to each other, A cooling medium flow path 7 for supplying the cooling medium is formed.

  In the metal separators 2a and 2b, the protrusions 5a and 6a are set at the same position with respect to the stacking direction with the MEA 1a interposed therebetween. In the metal separators 2b and 2c, the protrusions 5a and 6a are It is set at the same position with respect to the stacking direction across the MEA 1b.

  However, when the cooling medium flow path 7 is formed between the cell units 3, the cooling medium flow path 7 does not have a structure for supporting the metal separators 2c and 2a in the stacking direction. This is because the convex portion and the concave portion face each other in the stacking direction. For this reason, the load at the time of lamination | stacking of a fuel cell stack cannot be hold | maintained between each cell unit 3, and also there exists a problem that it cannot endure the pressure fluctuation at the time of electric power generation.

  As a result, the MEAs 1a and 1b and the metal separators 2a to 2c are deformed, and there is a problem that electrical conduction between the cell units 3 cannot be improved.

  Accordingly, it is possible to employ a fuel cell stack in which two types of first and second cell units having different concavo-convex shapes are prepared and the first cell units and the second cell units are alternately stacked. However, since three metal separators are used for each cell unit, six metal separators having different shapes must be manufactured, and there is a problem that the number of molds increases and it is not economical.

  The present invention provides a fuel cell having a thinned cooling structure of this type, which can reliably hold the structural unit between the power generation units forming the cooling medium flow path and can easily and economically manufacture the metal separator. It aims at providing the manufacturing method of the battery stack and the metal separator for fuel cells.

  The present invention has n (n is an even number) electrolyte / electrode structure in which a pair of electrodes are arranged on both sides of an electrolyte, and n + 1 metal separators stacked alternately with each electrolyte / electrode assembly. In addition, a reaction gas flow region for flowing a reaction gas, which is either a fuel gas or an oxidant gas, in the surface direction of the metal separator and a reaction gas communication hole for flowing the reaction gas in the stacking direction are formed. A fuel cell stack and a fuel cell metal that are alternately stacked by forming a cooling medium flow path between the first power generation unit and the second power generation unit The present invention relates to a method for manufacturing a separator.

  In this fuel cell stack, the metal separators arranged at the same positions in the first power generation unit and the second power generation unit have shapes in which the shape of the reaction gas circulation region is rotated by 180 ° within the separator surface. On the other hand, the communication hole shape including at least the reaction gas communication hole is set to be the same.

  The reactive gas flow region preferably includes at least a reactive gas flow channel for flowing the reactive gas along the power generation surface, and a buffer unit that communicates the reactive gas flow channel with the reactive gas communication hole.

  Furthermore, it is preferable that a buffer part is provided with an embossing part.

  Furthermore, it is preferable that a buffer part is provided with a continuous guide part.

  Further, in the method of manufacturing a fuel cell metal separator, at least a reaction gas is formed in each metal separator by a first step of forming a reaction gas circulation region in each metal separator by a first die and a second die. And a second step of forming a communication hole shape including the communication hole.

  One metal separator is disposed in the same posture in the first mold and the second mold, and the other metal separator has a thickness direction intersecting the surface direction as a rotation axis. The second mold is disposed so as to be rotated by 180 ° relative to the second mold.

  Further, in the second step, it is preferable to trim the outer shape of each metal separator at the same time as the communication hole shape is formed by the second mold.

  Furthermore, in the method for producing a fuel cell metal separator, at least the outer shape of each metal separator is formed by a first step of forming a reaction gas flow area in each metal separator with a first die and a second die. And a second step of performing trim processing.

  One metal separator is disposed in the same posture in each of the first mold and the second mold, and the other metal separator rotates in the thickness direction intersecting the plane direction. Thus, the second mold is disposed so as to be rotated by 180 ° relative to the second mold.

  According to the present invention, each metal separator disposed at the same position in the first power generation unit and the second power generation unit includes the first mold for forming the reaction gas flow area, and at least the reaction gas. It is possible to use a second mold that forms a communication hole shape including the communication hole or at least trims the outer shape of each metal separator. That is, one metal separator is disposed in the same posture in the first mold and the second mold, and the other metal separator has a thickness direction intersecting the plane direction as a rotation axis. Thus, the second mold is disposed so as to rotate by 180 ° relative to the second mold.

  Therefore, corresponding to each metal separator disposed at the same position in the first power generation unit and the second power generation unit, a dedicated first mold and a dedicated second mold are prepared. There is no need. As a result, the number of molds can be halved, and the metal separator manufacturing operation can be carried out economically and efficiently.

It is a principal part disassembled perspective explanatory drawing of the fuel cell stack which concerns on the 1st Embodiment of this invention. It is a principal part disassembled perspective explanatory drawing of the 1st electric power generation unit which comprises the said fuel cell stack. FIG. 3 is a sectional view of the fuel cell stack taken along line III-III in FIG. 2. It is a disassembled perspective explanatory view of the 3rd metal separator which constitutes the 1st power generation unit, and the 1st metal separator which constitutes the 2nd power generation unit. It is explanatory drawing of a 1st metal mold | die. It is explanatory drawing of a 2nd metal mold | die. It is explanatory drawing of the process of manufacturing one 1st metal separator. It is explanatory drawing of the process of manufacturing the other 1st metal separator. It is a principal part disassembled perspective explanatory drawing of the fuel cell stack which concerns on the 2nd Embodiment of this invention. It is explanatory drawing of a 2nd metal mold | die. It is explanatory drawing of the process of manufacturing one 1st metal separator. It is explanatory drawing of the process of manufacturing the other 1st metal separator. It is a principal part disassembled perspective explanatory drawing of the fuel cell stack which concerns on the 3rd Embodiment of this invention. It is a disassembled perspective explanatory drawing of the 1st electric power generation unit which comprises the said fuel cell stack. It is front explanatory drawing of the 1st metal separator which comprises the said 1st electric power generation unit. It is a partial perspective explanatory view of the entrance buffer part of the first metal separator. FIG. 17 is a cross-sectional explanatory view of the first metal separator taken along line XVII-XVII in FIG. 16. It is explanatory drawing of one surface of the 2nd metal separator which comprises the said 1st electric power generation unit. It is explanatory drawing of the other surface of the 2nd metal separator which comprises the said 1st electric power generation unit. It is front explanatory drawing of the 3rd metal separator which comprises the said 1st electric power generation unit. It is a disassembled perspective explanatory drawing of the 2nd cell unit which comprises the said fuel cell stack. FIG. 15 is a cross-sectional view of the fuel cell stack taken along line XXII-XXII in FIG. It is explanatory drawing of the process of manufacturing one 1st metal separator. It is explanatory drawing of the process of manufacturing the other 1st metal separator. It is a principal part disassembled perspective explanatory drawing of the fuel cell stack which concerns on the 4th Embodiment of this invention. It is a disassembled perspective explanatory drawing of the 1st electric power generation unit which comprises the said fuel cell stack. It is a disassembled perspective explanatory drawing of the 2nd electric power generation unit which comprises the said fuel cell stack. It is front explanatory drawing of the 1st metal separator which comprises the said 1st electric power generation unit. It is front explanatory drawing of the 2nd metal separator which comprises the said 1st electric power generation unit. It is explanatory drawing of the conventional fuel cell stack.

  FIG. 1 is an exploded perspective view of a main part of a fuel cell stack 10 according to the first embodiment of the present invention.

  The fuel cell stack 10 is configured by alternately stacking first power generation units 12A and second power generation units 12B along the horizontal direction (arrow A direction). As shown in FIG. 2, the first power generation unit 12A includes a first metal separator 14A, a first electrolyte membrane / electrode structure (MEA) (electrolyte / electrode structure) 16a, a second metal separator 18A, and a second electrolyte. The membrane / electrode structure 16b and the third metal separator 20A are provided. Note that the first power generation unit 12A may include four or more even number of MEAs, and may include five or more odd number of metal separators.

  The first metal separator 14A, the second metal separator 18A, and the third metal separator 20A are, for example, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, or a metal plate whose surface is subjected to anticorrosion treatment (described later). ). As will be described later, the first metal separator 14A, the second metal separator 18A, and the third metal separator 20A have a concavo-convex shape by pressing a metal plate into a wave shape.

  The first and second electrolyte membrane / electrode structures 16a and 16b include, for example, a solid polymer electrolyte membrane 22 in which a perfluorosulfonic acid thin film is impregnated with water, and an anode side sandwiching the solid polymer electrolyte membrane 22 The electrode 24 and the cathode side electrode 26 are provided.

  The anode side electrode 24 and the cathode side electrode 26 are uniformly coated on the surface of the gas diffusion layer with a gas diffusion layer (not shown) made of carbon paper or the like and porous carbon particles carrying a platinum alloy on the surface. And an electrode catalyst layer (not shown) formed. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 22.

  A fuel gas inlet communication hole 30a for supplying a fuel gas, for example, a hydrogen-containing gas, communicates with each other in the arrow A direction at one end edge in the long side direction (arrow B direction) of the first power generation unit 12A. A cooling medium inlet communication hole 32a for supplying a cooling medium and an oxidant gas outlet communication hole 34b for discharging an oxidant gas, for example, an oxygen-containing gas, are provided.

  The other end edge of the first power generation unit 12A in the long side direction (arrow B direction) communicates with each other in the direction of arrow A to supply an oxidant gas inlet hole 34a, a cooling medium, and the like. A cooling medium outlet communication hole 32b for discharging the fuel gas and a fuel gas outlet communication hole 30b for discharging the fuel gas are provided. The fuel gas outlet communication hole 30b is set to an opening shape smaller than the fuel gas inlet communication hole 30a, while the oxidant gas outlet communication hole 34b is set to an opening shape smaller than the oxidant gas inlet communication hole 34a. .

  On the surface 14a of the first metal separator 14A facing the first electrolyte membrane / electrode structure 16a, there is a first oxidant gas flow path 36 that connects the oxidant gas inlet communication hole 34a and the oxidant gas outlet communication hole 34b. It is formed. The first oxidizing gas channel 36 has a plurality of channel grooves 36a extending in the direction of arrow B.

  An inlet buffer section 38 and an outlet buffer section 40 are provided in the vicinity of the inlet and outlet of the first oxidant gas flow path 36 (or at least one of them) to form a first oxidant gas flow area (reaction gas flow area). Is done.

  The inlet buffer portion 38 and the outlet buffer portion 40 have a convex shape from the intermediate height to the front and back surfaces, and a plurality of convex portions (embossed portions) projecting to the surface 14a side (first electrolyte membrane / electrode structure 16a side). ) 38a, 40a and a plurality of convex portions (embosses) 38b, 40b projecting toward the surface 14b. The convex portions 38a, 38b, 40a, and 40b can be set in various shapes such as a circle, an oval, or a rectangle. The same applies to the following embossing.

  A part of the cooling medium flow path 44 that connects the cooling medium inlet communication hole 32a and the cooling medium outlet communication hole 32b is formed on the surface 14b of the first metal separator 14A. A plurality of flow channel grooves (concave portions) 44a having a back surface shape between the plurality of flow channel grooves 36a constituting the first oxidant gas flow channel 36 are formed on the surface 14b. In the vicinity of the inlet and outlet of the flow channel 44a, a buffer portion back surface shape having a plurality of convex portions 40b and 38b is provided.

  A first fuel gas channel 46 that communicates the fuel gas inlet communication hole 30a and the fuel gas outlet communication hole 30b is formed on the surface 18a of the second metal separator 18A facing the first electrolyte membrane / electrode structure 16a. . The first fuel gas channel 46 has a plurality of channel grooves (recesses) 46a extending in the direction of arrow B, and an inlet buffer 48 is provided near the inlet and outlet of the first fuel gas channel 46, respectively. And the outlet buffer unit 50 is provided to constitute a first fuel gas circulation region (reaction gas circulation region).

  The inlet buffer portion 48 and the outlet buffer portion 50 have convex shapes from the middle height to the front and back, and a plurality of convex portions (embossed portions) projecting to the surface 18a side (first electrolyte membrane / electrode structure 16a side). ) 48a, 50a, and a plurality of convex portions (embosses) 48b, 50b projecting to the surface 18b side (second electrolyte membrane / electrode structure 16b side).

  On the surface 18b of the second metal separator 18A facing the second electrolyte membrane / electrode structure 16b, there is a second oxidant gas flow path 52 that connects the oxidant gas inlet communication hole 34a and the oxidant gas outlet communication hole 34b. It is formed. The second oxidant gas flow channel 52 has a plurality of flow channel grooves (recesses) 52a extending in the direction of arrow B, and an inlet buffer portion is provided near the inlet and outlet of the second oxidant gas flow channel 52. 54 and the outlet buffer unit 56 are provided to constitute a second oxidant gas flow region (reactive gas flow region). The second oxidant gas channel 52 has a back surface shape of the first fuel gas channel 46, while the inlet buffer unit 54 and the outlet buffer unit 56 have the back surface shape of the inlet buffer unit 54 and the outlet buffer unit 56.

  A second fuel gas flow path 58 that connects the fuel gas inlet communication hole 30a and the fuel gas outlet communication hole 30b is formed on the surface 20a of the third metal separator 20A facing the second electrolyte membrane / electrode structure 16b. . The second fuel gas channel 58 has a plurality of channel grooves (recesses) 58a extending in the direction of arrow B. In the vicinity of the inlet and outlet of the second fuel gas channel 58, an inlet buffer part 60 and an outlet buffer part 62 are provided to constitute a second fuel gas circulation region (reactive gas circulation region).

  The inlet buffer unit 60 and the outlet buffer unit 62 have a convex shape from the middle height to the front and back, and a plurality of convex portions (embossed portions) projecting to the surface 20a side (second electrolyte membrane / electrode structure 16b side). ) 60a, 62a, and a plurality of convex portions (embosses) 60b, 62b projecting to the surface 20b side (second power generation cell 12B side).

  A part of the coolant flow path 44 is formed on the surface 20b of the third metal separator 20A. A plurality of flow channel grooves (concave portions) 44b that are the back surface shapes of the plurality of flow channel grooves 58a that constitute the second fuel gas flow channel 58 are formed on the surface 20b.

  In the first power generation unit 12A, when the first electrolyte membrane / electrode structure 16a is sandwiched between the first metal separator 14A and the second metal separator 18A, the first oxidizing gas channel 36 and the first In the fuel gas channel 46, the convex portions between the respective channel grooves 36a, 46a are arranged at the same position in the stacking direction. Similarly, when sandwiching the second electrolyte membrane / electrode structure 16b between the second metal separator 18A and the third metal separator 20A, the second oxidant gas flow path 52 and the second fuel gas flow path 58 are: The convex portions between the respective channel grooves 52a and 58a are arranged at the same position in the stacking direction.

  In each emboss, as shown in FIG. 3, in the first metal separator 14A and the second metal separator 18A, the protrusions 40a and 48a and 38a and 50a that protrude toward the first electrolyte membrane / electrode structure 16a are Are arranged at the same position in the stacking direction.

  In the second metal separator 18A and the third metal separator 20A, the convex portions 48b and 60a and 50b and 62a protruding toward the second electrolyte membrane / electrode structure 16b are disposed at the same position in the stacking direction. .

  As shown in FIG. 2, the first seal member 64 is integrally formed on the surfaces 14a and 14b of the first metal separator 14A so as to go around the outer peripheral edge of the first metal separator 14A. On the surfaces 18a and 18b of the second metal separator 18A, a second seal member 66 is integrally formed around the outer peripheral edge of the second metal separator 18A, and the surfaces 20a and 20b of the third metal separator 20A. The third seal member 68 is integrally formed around the outer peripheral edge of the third metal separator 20A.

  As shown in FIG. 1, the second power generation unit 12B includes a first metal separator 14B, a first electrolyte membrane / electrode structure 16a, a second metal separator 18B, a second electrolyte membrane / electrode structure 16b, and a third metal. A separator 20B is provided. The same components as those of the first power generation unit 12A are denoted by the same reference numerals, and detailed description thereof is omitted.

  The first metal separator 14B, the second metal separator 18B, and the third metal separator 20B are disposed at the same positions as the first metal separator 14A, the second metal separator 18A, and the third metal separator 20A of the first power generation unit 12A, respectively. Is done.

  The first metal separator 14B is set to a shape (hereinafter also referred to as point symmetry) in which the shape of the first oxidant gas circulation region is rotated by 180 ° within the separator surface with respect to the first metal separator 14A. Fuel gas inlet communication hole 30a, cooling medium inlet communication hole 32a, oxidant gas outlet communication hole 34b, oxidant gas inlet communication hole 34a, cooling medium outlet communication hole 32b, and fuel gas outlet communication hole 30b (hereinafter referred to as a communication hole group) The opening shape (communication hole shape) is set to be the same.

  Specifically, the first oxidant gas flow path 36, the inlet buffer section 38, and the outlet buffer section 40 constituting the first oxidant gas flow path area have a thickness that intersects the first metal separator 14A in the plane direction. When rotated 180 degrees about the vertical direction (direction of arrow A), the first oxidant gas flow areas of the first metal separators 14A and 14B have the same shape.

  Similarly, in the second metal separator 18B, the shapes of the first fuel gas circulation region and the second oxidant gas circulation region are set point-symmetrically with respect to the second metal separator 18A. In the third metal separator 20B, the shape of the second fuel gas circulation region is set point-symmetrically with respect to the third metal separator 20A.

  As shown in FIGS. 3 and 4, a cooling medium flow path is provided between the third metal separator 20A constituting the first power generation unit 12A and the first metal separator 14B constituting the second power generation unit 12B. 44 is formed. On both ends of the cooling medium flow path 44, convex portions 60b and 40b and convex portions 62b and 38b projecting from the third metal separator 20A and the first metal separator 14B to face each other are the same in the stacking direction. Placed in position. In addition, as for the flow-path grooves 44b and 44a, it is preferable that convex parts mutually are arrange | positioned in the same position in the lamination direction.

  FIG. 5 shows a first mold 70 for forming the first oxidant gas flow area in the first metal separators 14A and 14B, and FIG. 6 shows a communication hole group in the first metal separators 14A and 14B. A second mold 72 for forming is shown. The first mold 70 includes an uneven portion 74 having the shape of the first oxidant gas flow path 36, and buffer shape portions 76 a and 76 b having the shapes of the inlet buffer portion 38 and the outlet buffer portion 40.

  In order to trim the communication hole group, the second mold 72 includes trim holes 78a to 78c corresponding to the fuel gas inlet communication hole 30a, the cooling medium inlet communication hole 32a, and the oxidant gas outlet communication hole 34b. Agent gas inlet communication hole 34a, coolant outlet communication hole 32b, and trim holes 78d to 78f corresponding to fuel gas outlet communication hole 30b are provided. The second mold 72 can be trimmed on the outer shape of the first metal separators 14A and 14B.

  Next, when the first metal separator 14A is formed by the first mold 70 and the second mold 72, as shown in FIG. 7, first, a thin metal plate 80A is prepared. The metal plate 80 </ b> A is disposed in the first mold 70.

  In the first mold 70, the metal plate 80 </ b> A is pressed to form the first oxidant gas flow path 36 via the concavo-convex shape portion 74, while via the buffer shape portions 76 a and 76 b. Thus, the inlet buffer portion 38 and the outlet buffer portion 40 are formed.

  The metal plate 80A that has been formed by the first mold 70 is placed in the second mold 72 and trimmed in the same posture. By this trim processing, the metal plate 80A has a fuel gas inlet communication hole 30a, a cooling medium inlet communication hole 32a, an oxidant gas outlet communication hole 34b, and an oxidant gas inlet communication hole 34a corresponding to the trim holes 78a to 78f. The cooling medium outlet communication hole 32b and the fuel gas outlet communication hole 30b are formed, and trimming of the outer shape is simultaneously performed.

  A first metal separator 14A is manufactured by integrally forming a first seal member 64 on the metal plate 80A that has been trimmed by the second mold 72.

  On the other hand, when manufacturing the 1st metal separator 14B, as shown in FIG. 8, the thin plate-shaped metal plate 80B is prepared similarly. The metal plate 80B is substantially the same as the metal plate 80A.

  The metal plate 80B is formed in the same shape as the first oxidant gas flow area by being placed in the first mold 70 and subjected to press working. The metal plate 80B is rotated 180 ° with the thickness direction intersecting the surface direction as the rotation axis. For this reason, the second oxidant gas circulation region is obtained on the metal plate 80B by inverting the first oxidant gas circulation region by 180 °.

  Next, the metal plate 80B is disposed in the second mold 72 and is connected to the fuel gas inlet communication hole 30a, the cooling medium inlet communication hole 32a, the oxidant gas outlet communication hole 34b, the oxidant gas via the trim holes 78a to 78f. An inlet communication hole 34a, a cooling medium outlet communication hole 32b, and a fuel gas outlet communication hole 30b are formed.

  The first metal separator 14B is obtained by integrally forming the first seal member 64 on the metal plate 80B that has been trimmed by the second mold 72.

  In this case, in the first embodiment, the first metal separator 14A constituting the first power generation unit 12A and the first metal separator 14B constituting the second power generation unit 12B are the same in each unit. The first oxidant gas flow area is configured to be point-symmetric while being disposed at a position.

  On the other hand, the fuel gas inlet communication hole 30a and the fuel gas outlet communication hole 30b are not point-symmetric, and similarly, the oxidant gas inlet communication hole 34a and the oxidant gas outlet communication hole 34b are not point-symmetric. .

  For this reason, it is possible to use a single first mold 70 and a single second mold 72 in order to form the first metal separators 14A and 14B. That is, in the manufacturing process of the first metal separator 14A, as shown in FIG. 7, the first oxidation is performed by arranging the metal plate 80A on the first mold 70 and the second mold 72 in the same posture. The agent gas flow area and the communication hole group are formed.

  On the other hand, when manufacturing the 1st metal separator 14B, as shown in FIG. 8, the thickness which cross | intersects the metal plate 80B in the surface direction between the 1st metal mold | die 70 and the 2nd metal mold | die 72 is shown. The first oxidant gas circulation region and the communication hole group are formed simply by rotating the direction about the rotation axis by 180 °.

  Therefore, it is not necessary to prepare a dedicated first mold and a dedicated second mold for the first metal separator 14A and the first metal separator 14B, respectively. As a result, the number of molds can be halved, and the effect that the separator manufacturing operation is performed economically and efficiently can be obtained.

  Similarly, in the manufacturing work of the second metal separators 18A and 18B and the manufacturing work of the third metal separators 20A and 20B, it is possible to share the molds. There is an effect that it can be performed efficiently and efficiently.

  In the first embodiment, the manufacturing process of the first metal separator 14B includes a process of inverting the metal plate 80B between the first mold 70 and the second mold 72. However, the present invention is not limited to this. For example, during the manufacturing process of the first metal separator 14B, the first mold 70 is inverted 180 °, or the second mold 72 is inverted 180 °, while the metal plate 80B is in the same posture, It is also possible to arrange in one mold 70 and the second mold 72.

  The operation of the fuel cell stack 10 configured as described above will be described below.

  First, as shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas inlet communication hole 34a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas inlet communication hole 30a. Further, a cooling medium such as pure water, ethylene glycol, or oil is supplied to the cooling medium inlet communication hole 32a.

  Therefore, in the first power generation unit 12A, as shown in FIG. 2, the oxidant gas is supplied from the oxidant gas inlet communication hole 34a to the first oxidant gas flow path 36 of the first metal separator 14A and the second metal separator. 18 A of the second oxidant gas passage 52 is introduced. The oxidant gas moves in the direction of arrow B (horizontal direction) along the first oxidant gas flow path 36 and is supplied to the cathode side electrode 26 of the first electrolyte membrane / electrode structure 16a. It moves in the direction of arrow B along the oxidant gas flow path 52 and is supplied to the cathode electrode 26 of the second electrolyte membrane / electrode structure 16b.

  On the other hand, the fuel gas moves in the horizontal direction (in the direction of arrow B) along the first fuel gas flow path 46 of the second metal separator 18A from the fuel gas inlet communication hole 30a, and the first electrolyte membrane / electrode structure 16a. It is supplied to the anode side electrode 24. Further, the fuel gas moves in the direction of arrow B along the second fuel gas flow path 58 of the third metal separator 20A, and is supplied to the anode side electrode 24 of the second electrolyte membrane / electrode structure 16b.

  Therefore, in the first and second electrolyte membrane / electrode structures 16a and 16b, the oxidant gas supplied to the cathode side electrode 26 and the fuel gas supplied to the anode side electrode 24 are electrically generated in the electrode catalyst layer. It is consumed by chemical reaction to generate electricity.

  Next, the oxidant gas consumed by being supplied to the cathode-side electrodes 26 of the first and second electrolyte membrane / electrode structures 16a and 16b is discharged in the direction of arrow A along the oxidant gas outlet communication hole 34b. The Similarly, the fuel gas supplied to and consumed by the anode-side electrodes 24 of the first and second electrolyte membrane / electrode structures 16a and 16b is discharged to the fuel gas outlet communication hole 30b.

  On the other hand, as shown in FIGS. 3 and 4, the cooling medium supplied to the cooling medium inlet communication hole 32a constitutes the third metal separator 20A constituting the first power generation unit 12A and the second power generation unit 12B. After being introduced into the cooling medium flow path 44 formed between the first metal separator 14 </ b> A and the first metal separator 14 </ b> A, it flows in the direction of arrow B. The cooling medium cools the first and second electrolyte membrane / electrode structures 16a and 16b, and then is discharged into the cooling medium outlet communication hole 32b.

  In the second power generation unit 12B, power is generated by the first and second electrolyte membrane / electrode structures 16a and 16b in the same manner as the first power generation unit 12A.

  FIG. 9 is an exploded perspective view of a main part of a fuel cell stack 90 according to the second embodiment of the present invention. The same components as those of the fuel cell stack 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Similarly, in the third and subsequent embodiments described below, detailed description thereof is omitted.

  The fuel cell stack 90 is configured by alternately stacking first power generation units 92A and second power generation units 92B along the horizontal direction (arrow A direction). The first power generation unit 92A includes a first metal separator 94A, a first electrolyte membrane / electrode structure 16a, a second metal separator 96A, a second electrolyte membrane / electrode structure 16b, and a third metal separator 98A.

  A recess 100 is formed at the approximate center of the upper side of the first metal separator 14A, and a cell voltage terminal 102 is provided in the recess 100. The cell voltage terminal 102 detects a voltage generated in the first electrolyte membrane / electrode structure 16a and the second electrolyte membrane / electrode structure 16b. The second metal separator 18A and / or the third metal separator 20A may be provided with a cell voltage terminal 102 as necessary.

  The fuel gas inlet communication hole 30a, the cooling medium inlet communication hole 32a, and the oxidant gas outlet communication hole 34b provided at one end edge in the long side direction of the first power generation unit 92A may be set to have the same opening shape. . Similarly, the oxidant gas inlet communication hole 34a, the coolant outlet communication hole 32b, and the fuel gas outlet communication hole 30b provided at the other end edge in the long side direction of the first power generation unit 92A are set to have the same opening shape. May be.

  The second power generation unit 92B includes a first metal separator 94B, a first electrolyte membrane / electrode structure 16a, a second metal separator 96B, a second electrolyte membrane / electrode structure 16b, and a third metal separator 98B. The same components as those of the first power generation unit 92A are denoted by the same reference numerals, and detailed description thereof is omitted.

  In order to form the first oxidant gas flow area in the first metal separators 94A and 94B, the first mold 70 is used, while the outer shapes of the first metal separators 94A and 94B are trimmed. The mold 104 is shown in FIG. The second mold 104 has a trim line 106 corresponding to the outer shape of the first metal separators 94A and 94B. A concave portion 106 a corresponding to the concave portion 100 and a convex portion 106 b corresponding to the cell voltage terminal 102 are provided at substantially the center of one long side of the trim line 106.

  In the second embodiment configured as described above, when the first metal separator 94A is formed by the first mold 70 and the second mold 104, first, as shown in FIG. A metal plate 110A is prepared. The metal plate 110A is disposed in the first mold 70, and the first oxidant gas flow path 36, the inlet buffer part 38, and the outlet buffer part 40 are formed.

  The metal plate 110A subjected to the forming process by the first mold 70 is placed in the second mold 104 in the same posture and is subjected to external trim processing. By this outer trim processing, the metal plate 110A is processed into a desired outer shape and is accommodated in the recess 100 to form the cell voltage terminal 102.

  The fuel gas inlet communication hole 30a, the cooling medium inlet communication hole 32a, the oxidant gas outlet communication hole 34b, the oxidant gas inlet communication hole 34a, the cooling medium outlet communication hole 32b, and the fuel gas outlet communication hole 30b It may be formed simultaneously with the mold 104, or may be formed individually with another mold.

  On the other hand, when manufacturing the 1st metal separator 94B, as shown in FIG. 12, the thin metal plate 110B is prepared similarly. The metal plate 110B is substantially the same as the metal plate 110A.

  This metal plate 110B is formed in the same shape as the first oxidant gas flow area by being placed in the first mold 70 and subjected to press working. The metal plate 110B is rotated 180 ° with the thickness direction intersecting the plane direction as the rotation axis. For this reason, the second oxidant gas circulation region is obtained in the metal plate 110B by inverting the first oxidant gas circulation region by 180 °.

  Next, the metal plate 110B is disposed on the second mold 104 and subjected to external trim processing. Accordingly, the metal plate 110 </ b> B is processed into a desired outer shape and is accommodated in the recess 100 to form the cell voltage terminal 102.

  Thereby, in the second embodiment, the number of molds can be halved, and the same effects as those in the first embodiment can be obtained, for example, the separator manufacturing operation can be performed economically and efficiently.

  FIG. 13 is an exploded perspective view of a main part of a fuel cell stack 120 according to the third embodiment of the present invention.

  The fuel cell stack 120 is configured by alternately stacking first power generation units 122A and second power generation units 122B in the direction of arrow A.

  As shown in FIG. 14, the first power generation unit 122A includes a first metal separator 124A, a first electrolyte membrane / electrode structure (MEA) (electrolyte / electrode structure) 126a, a second metal separator 128A, and a second electrolyte. A membrane / electrode structure 126b and a third metal separator 130A are provided.

  The first metal separator 124A, the second metal separator 128A, and the third metal separator 130A are composed of, for example, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, or a metal plate whose surface has been subjected to anticorrosion treatment. Is done. The first metal separator 124A, the second metal separator 128A, and the third metal separator 130A have a concavo-convex shape by pressing a metal plate into a wave shape.

  One end edge of the first power generation unit 122A in the long side direction (arrow B direction) communicates with each other in the arrow A direction, and communicates with the fuel gas inlet communication hole 30a, the coolant outlet communication hole 32b, and the oxidant gas outlet communication. A hole 34b is provided. The other end edge of the first power generation unit 122A in the long side direction (arrow B direction) communicates with each other in the arrow A direction, and the oxidant gas inlet communication hole 34a, the cooling medium inlet communication hole 32a, and the fuel gas outlet. A communication hole 30b is provided.

  As shown in FIG. 15, the first metal separator 124A has a first surface that communicates the oxidant gas inlet communication hole 34a and the oxidant gas outlet communication hole 34b with the surface 124a facing the first electrolyte membrane / electrode structure 126a. An oxidizing gas channel 136A is formed. On the surface 14b of the first metal separator 124A, a first coolant flow path 138A that is the back surface shape of the first oxidant gas flow path 136A is formed.

  The first oxidizing gas channel 136A includes a plurality of linear channels 140a extending in the direction of arrow B along the power generation surface and arranged in the direction of arrow C, and the vicinity of the inlet of the linear channel 140a and It has an inlet buffer part 142a and an outlet buffer part 142b provided in the vicinity of the outlet. The straight flow path 140a is formed between the straight flow path protrusions 140b protruding toward the surface 124a. The first oxidant gas flow path 136A, the inlet buffer part 142a, and the outlet buffer part 142b constitute a first oxidant gas flow area (reaction gas flow area).

  The inlet buffer 142a includes a plurality of embossed protrusions 146a that protrude from the intermediate height 144a toward the first oxidant gas flow path 136A. The outlet buffer 142b includes a plurality of embossed protrusions 146b that protrude from the intermediate height 144b toward the first oxidant gas flow path 136A. The embossed protrusions 146a and 146b are arranged in a plurality of rows, each having a predetermined number of embossed groups arranged in a row.

  As shown in FIG. 14, on the other surface 124b of the first metal separator 124A, a first coolant flow path 138A that is the back surface shape of the first oxidant gas flow path 136A is formed. The first cooling medium flow path 138A includes a plurality of linear flow paths 148a extending in the direction of arrow B along the power generation surface and arranged in the direction of arrow C, and the vicinity and the outlet of the linear flow path 148a. It has an inlet buffer unit 150a and an outlet buffer unit 150b provided in the vicinity.

  The straight flow path 148a is formed between the straight flow path protrusions 148b protruding toward the surface 124a. The straight flow path 148a has a back surface shape of the straight flow path protrusion 140b, while the straight flow path protrusion 148b has a back surface shape of the straight flow path 140a. The inlet buffer unit 150a has a back surface shape of the inlet buffer unit 142a, while the outlet buffer unit 150b has a back surface shape of the outlet buffer unit 142b.

  As shown in FIGS. 16 and 17, the inlet buffer portion 150a includes a continuous guide convex portion 152a that protrudes from the intermediate height portion 144a toward the first cooling medium flow path 138A. The depth from the intermediate height portion 144a to the continuous guide convex portion 152a is set to be equal to the depth from the intermediate height portion 144a to the embossed raised portion 146a.

  As shown in FIG. 14, the outlet buffer part 150b includes a continuous guide convex part 152b protruding from the intermediate height part 144b to the first cooling medium flow path 138A side. A predetermined number of embossed raised portions 146a (embossed group) and continuous guide convex portions 152a arranged in a row are alternately provided on the front and back of the first metal separator 124A, and a predetermined number arranged in a row. Embossed protrusions 146b (embossed group) and continuous guide protrusions 152b are alternately provided.

  As shown in FIG. 18, a first fuel gas channel 154A is formed on a surface 128a of the second metal separator 128A facing the first electrolyte membrane / electrode structure 126a. A second oxidant gas channel 156A that is the back surface shape of the first fuel gas channel 154A is formed on the surface 128b toward the second electrolyte membrane / electrode structure 126b.

  The first fuel gas channel 154A includes a plurality of linear channels 158a extending in the direction of arrow B along the power generation surface and arranged in the direction of arrow C, and the vicinity of the inlet and the outlet of the linear channel 158a. It has an inlet buffer unit 160a and an outlet buffer unit 160b provided in the vicinity. The straight flow path 158a is formed between the straight flow path protrusions 158b protruding toward the surface 128a. 154A of 1st fuel gas flow paths, the entrance buffer part 160a, and the exit buffer part 160b comprise the 1st fuel gas distribution area (reaction gas distribution area).

  The inlet buffer portion 160a includes a continuous guide convex portion 164a that protrudes from the intermediate height portion 162a toward the first fuel gas flow path 154A. Each continuous guide convex part 164a is provided so as to guide the fuel gas from the fuel gas inlet communication hole 30a to the linear flow path 158a. The outlet buffer 160b includes a continuous guide protrusion 164b that protrudes from the intermediate height 162b toward the first fuel gas flow path 154A. Each continuous guide convex part 164b is provided so as to guide the fuel gas from the linear flow path 158a to the fuel gas outlet communication hole 30b.

  On the surface 128b of the second metal separator 128A, as shown in FIG. 19, a second oxidant gas channel 156A that is the back surface shape of the first fuel gas channel 154A is formed. The second oxidant gas flow path 156A, the inlet buffer portion 142a, and the outlet buffer portion 142b constitute a second oxidant gas flow region (reactive gas flow region). The second oxidant gas flow path 156A is configured in the same manner as the first oxidant gas flow path 136A, and the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 14, a second fuel gas channel 166A is formed on the surface 130a of the third metal separator 130A facing the second electrolyte membrane / electrode structure 126b, and on the opposite surface 130b, A second coolant flow path 168A having a back surface shape of the second fuel gas flow path 166A is formed. The second fuel gas channel 166A, the inlet buffer unit 160a, and the outlet buffer unit 160b constitute a second fuel gas flow region (reactive gas flow region). The second fuel gas flow channel 166A is configured in the same manner as the first fuel gas flow channel 154A, and the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 20, the second cooling medium channel 168A includes a plurality of linear channels 170a extending in the direction of arrow B along the power generation surface and arranged in the direction of arrow C, and the linear flow. It has an inlet buffer portion 172a and an outlet buffer portion 172b provided near the inlet and the outlet of the passage 170a.

  The straight flow path 170a is formed between the straight flow path projections 70b protruding to the surface 130b side. The inlet buffer portion 172a and the outlet buffer portion 172b include a plurality of embossed convex portions 174a and 174b that protrude from the intermediate height portions 162b and 162a toward the second cooling medium flow path 168A.

  In the first power generation unit 122A, when the first electrolyte membrane / electrode structure 126a is sandwiched between the first metal separator 124A and the second metal separator 128A, the first oxidizing gas channel 136A and the first In the fuel gas channel 154A, the embossed protrusions 146a and 146b and the continuous guide protrusions 164b and 164a are arranged at the same position in the stacking direction. The embossed protrusions 146a and 146b and the continuous guide protrusions 164b and 164a sandwich the first electrolyte membrane / electrode structure 126a.

  Similarly, when sandwiching the second electrolyte membrane / electrode structure 126b between the second metal separator 128A and the third metal separator 130A, the second oxidant gas channel 156A and the second fuel gas channel 166A are embossed. The protruding portions 146a and 146b and the continuous guide protruding portions 164b and 164a are arranged at the same position in the stacking direction. The embossed protrusions 146a and 146b and the continuous guide protrusions 164b and 164a sandwich the second electrolyte membrane / electrode structure 126b.

  As shown in FIG. 14, a first seal member 168a is integrally formed on the surfaces 124a and 124b of the first metal separator 124A around the outer peripheral edge of the first metal separator 124A. On the surfaces 128a and 128b of the second metal separator 128A, a second seal member 168b is integrally formed around the outer peripheral edge of the second metal separator 128A, and the surfaces 130a and 130b of the third metal separator 130A. The third seal member 168c is integrally formed around the outer peripheral edge of the third metal separator 130A.

  As shown in FIG. 21, the second power generation unit 122B includes a first metal separator 124B, a first electrolyte membrane / electrode structure 126a, a second metal separator 128B, a second electrolyte membrane / electrode structure 126b, and a third metal. A separator 130B is provided. The same components as those of the first power generation unit 122A are denoted by the same reference numerals, and detailed description thereof is omitted.

  A first oxidant gas flow path 136B that connects the oxidant gas inlet communication hole 34a and the oxidant gas outlet communication hole 34b is formed on the surface 124a of the first metal separator 124B facing the first electrolyte membrane / electrode structure 126a. It is formed. A first cooling medium flow path 138B having a back surface shape of the first oxidant gas flow path 136B is formed on the surface 124b of the first metal separator 124B.

  In the first oxidant gas flow paths 136A and 136B, the phases of the straight flow path projections 140b are different, and the concavities and convexities are set reversely on the front and back sides. In the first cooling medium flow paths 138A and 138B, the phases of the linear flow path protrusions 148b are different, and the concavities and convexities are set reversely on the front and back sides. The embossed protrusions 146a and 146b have different phases and the continuous guide protrusions 152a and 152b have different phases, and the embossed protrusions 146a and the continuous guide protrusions 152b and the embossed protrusions 146b and the continuous guide. The arrangement order of the convex portions 152a is alternately set reversely.

  When the first metal separator 124A is rotated 180 ° with the thickness direction (arrow A direction) intersecting the plane direction as the rotation axis, the first oxidant gas flow path regions of the first metal separators 124A and 124B are Have the same shape.

  A first fuel gas channel 154B is formed on a surface 128a of the second metal separator 128B facing the first electrolyte membrane / electrode structure 126a, and a surface 128b facing the second electrolyte membrane / electrode structure 126b is formed on the surface 128b of the second metal separator 128B. A second oxidant gas passage 156B having a back surface shape of the first fuel gas passage 154B is formed.

  In the first fuel gas flow paths 154A and 154B, the phases of the linear flow path protrusions 158b are different, and the concavities and convexities are set reversely on the front and back sides. In the second oxidant gas flow paths 156A, 156B, the phases of the linear flow path projections 140b are different, and the concavities and convexities are set reversely on the front and back sides. The embossing protrusions 146a and 146b have different phases and the continuous guide protrusions 164a and 164b are different in phase, and the embossing protrusions 146a and the continuous guide protrusions 164b and the embossing protrusions 146b and the continuous guide. The arrangement order of the convex portions 164a is alternately reversed.

  A second fuel gas channel 166B is formed on the surface 130a of the third metal separator 130B facing the second electrolyte membrane / electrode structure 126b, and the second fuel gas channel is formed on the opposite surface 130b. A second cooling medium flow path 168B having a back surface shape of 166B is formed.

  In the second fuel gas flow paths 166A and 166B, the phases of the linear flow path protrusions 58b and the phases of the continuous guide protrusions 164a and 164b are different. In the second cooling medium channels 168A and 168B, the phases of the linear channel protrusions 170b and the phases of the embossed protrusions 174a and 174b are different (see FIG. 22).

  In the second metal separator 128B, the shapes of the first fuel gas circulation region and the second oxidant gas circulation region are set point-symmetrically with respect to the second metal separator 128A. Similarly, in the third metal separator 130B, the shape of the second fuel gas circulation region is set point-symmetrically with respect to the third metal separator 130A.

  In the third embodiment configured as described above, when forming the first metal separator 124A, first, as shown in FIG. 23, a thin metal plate 180A is prepared. The metal plate 180A is disposed in the first mold 182, and the first oxidant gas flow path 136A, the inlet buffer part 142a, and the outlet buffer part 142b are formed.

  The metal plate 180A subjected to the forming process by the first mold 182 is arranged in the second mold 184 while being in the same posture and is subjected to trim processing. By this trim processing, the metal plate 180A has a fuel gas inlet communication hole 30a, a cooling medium inlet communication hole 32a, an oxidant gas outlet communication hole 34b, an oxidant gas inlet communication hole 34a, a cooling medium outlet communication hole 32b, and a fuel gas. The outlet communication hole 30b is formed, and trimming of the outer shape is simultaneously performed.

  On the other hand, when manufacturing the 1st metal separator 124B, as shown in FIG. 24, the thin plate-shaped metal plate 180B is prepared similarly. The metal plate 180B is substantially the same as the metal plate 180A.

  The metal plate 180B is formed in the same shape as the first oxidant gas flow area by being placed in the first mold 182 and subjected to press working. The metal plate 180B is rotated 180 ° with the thickness direction intersecting the plane direction as the rotation axis. Instead of rotating the metal plate 180B by 180 °, the first mold 182 may be rotated by 180 °.

  Next, the metal plate 180B is disposed in the second mold 184, and the fuel gas inlet communication hole 30a, the cooling medium inlet communication hole 32a, the oxidant gas outlet communication hole 34b, the oxidant gas inlet communication hole 34a, and the cooling medium. An outlet communication hole 32b and a fuel gas outlet communication hole 30b are formed.

  Thereby, in 3rd Embodiment, the number of metal mold | dies can be reduced by half, and the effect similar to said 1st and 2nd embodiment, such as a separator manufacturing operation being performed economically and efficiently, is carried out. can get.

  FIG. 25 is an exploded perspective view of a main part of a fuel cell stack 190 according to the fourth embodiment of the present invention.

  The same components as those of the fuel cell stack 120 according to the third embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The fuel cell stack 190 is configured by alternately stacking first power generation units 192A and second power generation units 192B in the direction of arrow A. The first power generation unit 192A includes a first metal separator 194A, a first electrolyte membrane / electrode structure 126a, a second metal separator 196A, a second electrolyte membrane / electrode structure 126b, and a third metal separator 198A (FIG. 25). And FIG. 26).

  As shown in FIGS. 25 and 27, the second power generation unit 192B includes a first metal separator 194B, a first electrolyte membrane / electrode structure 126a, a second metal separator 196B, a second electrolyte membrane / electrode structure 126b, and A third metal separator 198B is provided.

  As shown in FIG. 28, the first metal separator 194A constituting the first power generation unit 192A is provided with a first oxidant gas flow path 136A on the surface 194a. The first oxidizing gas channel 136A has an inlet buffer part 142a and an outlet buffer part 142b on both sides of the linear channel 140a.

  The inlet buffer portion 142a and the outlet buffer portion 142b are provided with a plurality of continuous guide convex portions 200a and 200b that protrude toward the first oxidizing gas channel 136A. The continuous guide protrusion 200a guides the oxidant gas from the oxidant gas inlet communication hole 34a to the linear flow path 140a, and the continuous guide protrusion 200b extends from the linear flow path 140a to the oxidant gas outlet communication hole 34b. To guide the oxidizing gas.

  As shown in FIG. 26, a first coolant flow path 138A is provided on the surface 194b of the first metal separator 194A. The first cooling medium channel 138A includes an inlet buffer unit 150a and an outlet buffer unit 150b, and the inlet buffer unit 150a and the outlet buffer unit 150b include a plurality of protrusions protruding toward the first cooling medium channel 138A. Embossed convex portions 202a and 202b are provided. The predetermined number of embossed protrusions 202a and 202b are arranged in one row and alternately with the continuous guide protrusions 200a and 200b.

  A first fuel gas passage 154A is formed on the surface 196a of the second metal separator 196A, and the first fuel gas passage 154A has an inlet buffer portion 160a and an outlet buffer portion 160b. The inlet buffer portion 160a and the outlet buffer portion 160b include a plurality of embossed convex portions 204a and 204b that protrude toward the first fuel gas channel 154A.

  A second oxidant gas flow path 156A is formed on the surface 196b of the second metal separator 196A as shown in FIG. A plurality of continuous guide protrusions 206a and 206b projecting toward the second oxidant gas flow channel 156A are formed in the inlet buffer portion 142a and the outlet buffer portion 142b constituting the second oxidant gas flow channel 156A.

  As shown in FIG. 26, a second fuel gas channel 166A is provided on the surface 198a of the third metal separator 198A. A plurality of embossed protrusions 208a and 208b projecting into the second fuel gas channel 166A are formed in the inlet buffer unit 160a and the outlet buffer unit 160b that constitute the second fuel gas channel 166A.

  A second coolant flow path 168A is formed on the surface 198b of the third metal separator 198A. A plurality of continuous guide protrusions 210a and 210b projecting toward the second cooling medium flow path 168A are formed in the inlet buffer section 150a and the outlet buffer section 150b constituting the second cooling medium flow path 168A.

  In the first power generation unit 192A, the continuous guide convex portions 200a and 200b constituting the first oxidant gas flow path 136A and the embossed convex portions 204b and 204a constituting the first fuel gas flow path 154A of the second metal separator 196A. Protrudes toward the first electrolyte membrane / electrode structure 126a and overlaps in the stacking direction to sandwich the first electrolyte membrane / electrode structure 126a.

  The continuous guide convex portions 206a and 206b constituting the second oxidant gas flow path 156A of the second metal separator 196A and the embossed convex portions 208b and 208a constituting the second fuel gas flow path 166A of the third metal separator 198A The second electrolyte membrane / electrode structure 126b protrudes to a position overlapping in the stacking direction to sandwich the second electrolyte membrane / electrode structure 126b.

  In the first power generation unit 192A and the second power generation unit 192B, in the first oxidant gas flow paths 136A, 36B, the phases of the continuous guide protrusions 200a, 200b are different from each other, and the second oxidant gas flow paths 156A, In 56B, the phases of the continuous guide convex portions 206a and 206b are different.

  In the first fuel gas flow paths 154A and 154B, the embossed protrusions 204a and 204b have different phases, and in the second fuel gas flow paths 166A and 166B, the embossed protrusions 28a and 208b have different phases.

  In the fourth embodiment configured as described above, the first metal separator 194A configuring the first power generation unit 192A and the first metal separator 194B configuring the second power generation unit 192B are included in each unit. And the shape of the first oxidant gas flow area is set point-symmetrically. As a result, the number of molds can be halved, and the same effects as those of the first to third embodiments can be obtained, for example, the separator manufacturing operation can be performed economically and efficiently.

10, 90, 120, 190 ... Fuel cell stacks 12A, 12B, 92A, 92B, 122A, 122B, 192A, 192B ... Power generation units 14A, 14B, 18A, 18B, 20A, 20B, 94A, 94B, 96A, 96B, 98A 98B, 124A, 124B, 128A, 128B, 130A, 130B, 194A, 194B, 196A, 196B, 198A, 198B ... Metal separators 16a, 16b, 126a, 126b ... Electrolyte membrane / electrode structure 22 ... Solid polymer electrolyte membrane 24 ... Anode-side electrode 26 ... Cathode-side electrode 36, 52, 136A, 136B, 156A, 156B ... Oxidant gas flow path 38, 48, 54, 60, 142a, 150a, 160a, 172a ... Inlet buffer 38a, 38b, 40a, 40b, 48a, 48 b, 50a, 50b, 60a, 60b, 62a, 62b ... convex portions 40, 50, 56, 62, 142b, 150b, 160b, 172b ... outlet buffer portions 44, 138A, 138B, 168A, 168B ... cooling medium flow path 46 , 58, 154A, 154B, 166A, 166B ... Fuel gas flow paths 70, 72, 104 ... Mold 74 ... Concave and convex portions 76a, 76b ... Buffer shape portions 78a-78f ... Trim holes 80A, 80B, 110A, 110B ... Metal Plate 100 ... Concave 102 ... Cell voltage terminals 146a, 146b ... Embossed protrusions 152a, 152b, 164a, 164b, 200a, 200b, 206a, 206b, 210a, 210b ... Continuous guide protrusions 174a, 174b, 202a, 202b, 204a , 204b, 208a, 208b ... Embo Convex portions 180A, 180B ... metal plate

Claims (10)

A fuel gas comprising n (n is an even number) electrolyte / electrode structure having a pair of electrodes disposed on both sides of the electrolyte, and (n + 1) metal separators alternately stacked with each electrolyte / electrode assembly. Or a first gas generating unit in which a reaction gas flow region for flowing a reaction gas which is either an oxidant gas in the surface direction of the metal separator and a reaction gas communication hole for flowing the reaction gas in the stacking direction are formed; A fuel cell stack comprising a second power generation unit, wherein a cooling medium flow path is formed between the first power generation unit and the second power generation unit and is alternately stacked;
The metal separators arranged at the same position in the first power generation unit and the second power generation unit are set such that the shape of the reaction gas flow area is rotated by 180 ° within the separator surface. On the other hand, the fuel cell stack is characterized in that the communication hole shape including at least the reaction gas communication hole is set to be the same. 2. The fuel cell stack according to claim 1, wherein the reaction gas flow region includes at least a reaction gas flow channel for flowing the reaction gas along a power generation surface,
A buffer portion communicating the reaction gas flow path and the reaction gas communication hole;
A fuel cell stack comprising:   The fuel cell stack according to claim 2, wherein the buffer portion includes an embossed portion.   4. The fuel cell stack according to claim 2, wherein the buffer unit includes a continuous guide unit. A fuel gas comprising n (n is an even number) electrolyte / electrode structure having a pair of electrodes disposed on both sides of the electrolyte, and (n + 1) metal separators alternately stacked with each electrolyte / electrode assembly. Or a first gas generating unit in which a reaction gas flow region for flowing a reaction gas which is either an oxidant gas in the surface direction of the metal separator and a reaction gas communication hole for flowing the reaction gas in the stacking direction are formed; In a fuel cell stack comprising a second power generation unit and alternately stacked by forming a cooling medium flow path between the first power generation unit and the second power generation unit, And a method of manufacturing a metal separator for a fuel cell, which manufactures each metal separator disposed at the same position in the second power generation unit,
A first step of forming the reactive gas flow area in each metal separator by a first mold;
A second step of forming a communication hole shape including at least the reaction gas communication hole in each metal separator by a second mold;
Have
One of the metal separators is disposed in the same posture on the first mold and the second mold, respectively.
The other metal separator is disposed by being rotated by 180 ° relative to the second mold with a thickness direction intersecting the plane direction as a rotation axis. Manufacturing method. 6. The manufacturing method according to claim 5, wherein the reaction gas flow region includes at least a reaction gas flow channel for allowing the reaction gas to flow along a power generation surface.
A buffer portion communicating the reaction gas flow path and the reaction gas communication hole;
The manufacturing method of the metal separator for fuel cells characterized by having.   6. The method of manufacturing a fuel cell metal separator according to claim 5, wherein the buffer portion has an embossed portion.   7. The method of manufacturing a metal separator for a fuel cell according to claim 5, wherein the buffer portion has a continuous guide portion.   9. The manufacturing method according to claim 5, wherein in the second step, the shape of the communication hole is formed by the second mold, and at the same time, trim processing is performed on the outer shape of each metal separator. The manufacturing method of the metal separator for fuel cells characterized by performing. A fuel gas comprising n (n is an even number) electrolyte / electrode structure having a pair of electrodes disposed on both sides of the electrolyte, and (n + 1) metal separators alternately stacked with each electrolyte / electrode assembly. A first power generation unit in which a reaction gas flow region for flowing a reaction gas that is either an oxidant gas in the surface direction of the metal separator and a reaction gas communication hole for flowing the reaction gas in the stacking direction are formed; In a fuel cell stack comprising a second power generation unit and alternately stacked by forming a cooling medium flow path between the first power generation unit and the second power generation unit, And a method of manufacturing a metal separator for a fuel cell, which manufactures each metal separator disposed at the same position in the second power generation unit,
A first step of forming the reactive gas flow area in each metal separator by a first mold;
A second step of trimming at least the outer shape of each metal separator with a second mold;
Have
One of the metal separators is disposed in the same posture on the first mold and the second mold, respectively.
The other metal separator is disposed by being rotated by 180 ° relative to the second mold with a thickness direction intersecting the plane direction as a rotation axis. Manufacturing method.

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