Separator with double-sided gasket and method for manufacturing stack

Abstract

To manufacture a separator with a double-sided gasket capable of protecting an inner peripheral surface of a manifold, and a stack.SOLUTION: The method for manufacturing the bipolar plate 2 with the double-sided gasket includes an arrangement step of arranging the bipolar plate main body 20 in the mold of the mold 8 in a mold open state so that the gate G of the mold 8 faces the manifold 20La to 20Lc and the manifold 20Ra to 20Rc, and clamping the mold 8, a material injection step of injecting the material E into the cavity 5c of the mold 8 from the manifold 20La to 20Lc and the manifold 20Ra to 20Rc, and a hardening step of hardening the material E injected into the cavity to integrally mold the covering portion, the front-side gasket, and the back-side gasket, and joining them to the bipolar plate main body 20. 5c 5M 5D 5U.SELECTED DRAWING: Figure 20

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a separator with a double-sided gasket and a stack for a fuel cell including the separator with the double-sided gasket. [Background technology]

[0002] The fuel cell described in Patent Document 1 includes a membrane electrode assembly, a cathode-side separator, and an anode-side separator. The cathode-side separator includes a separator body and a sealing material. The separator body has through-holes. The sealing material is integrally molded on both the front and back sides of the separator body.

[0003] In the manufacturing method for the cathode-side separator, first, the separator body is sandwiched between an upper mold and a lower mold. In this state, cavities for molding the sealant are defined on both the top and bottom sides of the separator body. Next, molten sealant (raw material for the sealant) is injected into the cavity of the upper mold from the gate of the upper mold. The molten sealant spreads through the through-holes into the cavity of the lower mold. Next, in this state, the molten sealant is cured to mold the sealant. In this manner, the cathode-side separator is manufactured. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-237317 Summary of the Invention [Problem to be solved by the invention]

[0005] The separator body of the cathode-side separator in this document is a press-molded product made of a metal plate. The inner circumferential surface of the manifold of the separator body is exposed to the internal space of the manifold. This exposes the inner circumferential surface to fluids (fuel gas, oxidizer gas, coolant, etc.) flowing through the manifold, making the inner circumferential surface susceptible to deterioration (corrosion, etc.). Therefore, the manufacturing method of a separator and stack with a double-sided gasket disclosed herein aims to manufacture a separator and stack with a double-sided gasket that can protect the inner circumferential surface of the manifold. [Means for solving the problem]

[0006] (1) In order to solve the above-mentioned problems, the present disclosure provides a method for manufacturing a separator with a double-sided gasket, comprising: a separator body that is a press-formed metal plate and has a manifold that penetrates the separator body in the front-to-back direction and through which a predetermined fluid flows; an elastomer covering portion that is disposed on the inner peripheral surface of the manifold; an elastomer front-side gasket that is disposed on the surface of the separator body; and an elastomer back-side gasket that is disposed on the back surface of the separator body, wherein the front-side gasket is made of the elastomer and has a front-side flow path portion through which the predetermined fluid flows, and the back-side gasket is a manufacturing method for a double-sided gasketed separator made of the elastomer and having a back-side flow path portion through which a predetermined fluid flows, and is characterized by comprising: an arrangement step of arranging the separator body in the mold in an open state so that the mold gate faces the manifold and then closing the mold; a raw material injection step of injecting raw material from the manifold into the cavity of the mold; and a curing step of hardening the raw material injected into the cavity to integrally mold the covering portion, the front-side gasket, and the back-side gasket and join them to the separator body.

[0007] According to this configuration, a covering portion is formed on the inner peripheral surface of the manifold. This allows the inner peripheral surface to be protected. Furthermore, according to this configuration, the covering portion, the front gasket, and the rear gasket are integrally molded. This allows the front gasket and the rear gasket to be prevented from peeling from each other via the covering portion.

[0008] Furthermore, with this configuration, the covering portion, front gasket, and rear gasket are manufactured from a common material. Therefore, compared to when these components are made from different materials, the manufacturing cost can be reduced by using only a single type of material. Also, the number of manufacturing steps can be reduced.

[0009] Furthermore, with this configuration, the covering portion, front gasket, and rear gasket are molded as a single unit. Therefore, compared to when the covering portion, front gasket, and rear gasket are molded separately, only one mold is required, thereby reducing manufacturing costs and man-hours.

[0010] Furthermore, with this configuration, the raw material is injected into the cavities using a manifold. This reduces the variation in the flow distance and filling time of the raw material between the front gasket cavity and the back gasket cavity. This reduces the variation in molding precision between the front gasket and the back gasket.

[0011] (1-1) In the configuration of (1) above, it is preferable that, when viewed from the front-back direction, the outer edge of the front gasket and the outer edge of the back gasket overlap, and the inner edge of the front gasket and the inner edge of the back gasket overlap.

[0012] With this configuration, the silhouette of the front gasket (the outline shape when illuminated from the front and back) overlaps with the silhouette of the back gasket when viewed from the front and back, which improves the shape stability of the fuel cell stack.

[0013] Furthermore, in the raw material injection process, it is possible to secure cavities of the same shape on both the front and back sides of the separator body (a cavity for a front gasket and a cavity for a back gasket), which makes it possible to suppress deformation of the separator body even when the separator body is thin.

[0014] (1-2) In any of the above configurations, the cavity has a covering portion cavity for molding the covering portion, a front gasket cavity connected to the covering portion cavity for molding the front gasket, and a rear gasket cavity connected to the covering portion cavity for molding the rear gasket, and it is preferable that in the raw material injection step, the raw material is configured to start from the covering portion cavity and be divided into the front gasket cavity and the rear gasket cavity.

[0015] With this configuration, the raw material flows from the covering cavity in the manifold into the front gasket cavity and the back gasket cavity. This reduces the variation in the flow distance and filling time between the front gasket cavity and the back gasket cavity. This reduces the variation in molding accuracy between the front gasket and the back gasket.

[0016] (1-3) In the configuration of (1-2) above, it is preferable that the mold, in a clamped state, has a front-side abutment portion that is placed in the front gasket cavity and abuts against the front surface of the separator body, and a back-side abutment portion that is placed in the back gasket cavity and abuts against the back surface of the separator body, and that the front-side abutment portion and the back-side abutment portion overlap when viewed from the front-back direction.

[0017] According to this configuration, the separator body is supported from both the front and back sides by the front and back contact portions, which makes it possible to suppress deformation of the separator body during the raw material injection step.

[0018] (2) In any of the above configurations, the cavity has a covering portion cavity for molding the covering portion, a front gasket cavity connected to the covering portion cavity for molding the front gasket, and a back gasket cavity connected to the covering portion cavity for molding the back gasket, the front gasket cavity has a front base layer cavity that is narrowest in the front-to-back direction among the front gasket cavities, and the back gasket cavity has a back base layer cavity that is narrowest in the front-to-back direction among the back gasket cavities, and it is preferable that the front base layer cavity and the back base layer cavity overlap when viewed from the front-to-back direction.

[0019] According to this configuration, the cavity for the top base layer and the cavity for the bottom base layer face each other in the front-to-back direction, sandwiching the separator body between them. This prevents the separator body from deforming during the raw material injection process, thereby improving the molding accuracy of the top gasket and the bottom gasket.

[0020] (2-1) In the above-mentioned configuration (2), the front gasket preferably has a front base layer molded in the front base layer cavity, and the thickness of the front base layer in the front-back direction is set to be within the range of 100% to 300% of the thickness of the separator body in the front-back direction.

[0021] According to this configuration, the thickness in the front-back direction is set to 100% or more. Therefore, the forming accuracy of the front base layer can be improved compared to when the thickness in the front-back direction is less than 100%. Also, according to this configuration, the thickness in the front-back direction is set to 300% or less. Therefore, the forming accuracy of the front base layer can be improved compared to when the thickness in the front-back direction is more than 300%.

[0022] (2-2) In the configuration of (2) or (2-1) above, the rear gasket preferably has a rear base layer molded into the cavity for the rear base layer, and the thickness of the separator body in the front-to-back direction is preferably set to be within the range of 100% to 300% of the thickness of the separator body in the front-to-back direction.

[0023] According to this configuration, the thickness in the front-back direction is set to 100% or more. Therefore, the forming accuracy of the back base layer can be improved compared to when the thickness in the front-back direction is less than 100%. Also, according to this configuration, the thickness in the front-back direction is set to 300% or less. Therefore, the forming accuracy of the back base layer can be improved compared to when the thickness in the front-back direction is more than 300%.

[0024] (3) In any of the above configurations, it is preferable that the separator body has a plurality of the manifolds, and that the separator body has a manifold selection step of selecting, before the placement step, the manifold to be used for injecting the raw material from among the plurality of manifolds in accordance with the fluidity of the raw material.

[0025] According to this configuration, the arrangement and number of manifolds used for raw material injection can be adjusted depending on the fluidity of the raw material. For example, if the raw material has high fluidity (e.g., silicone rubber), the number of manifolds used for raw material injection can be reduced. On the other hand, if the raw material has low fluidity (e.g., EPDM (ethylene propylene diene rubber)), the number of manifolds used for raw material injection can be increased.

[0026] (4) In order to solve the above-mentioned problems, the manufacturing method of a fuel cell stack of the present disclosure is a manufacturing method of a fuel cell stack including a stack of a plurality of cells, wherein the cells include a first separator manufactured by any of the manufacturing methods of a separator with a double-sided gasket described above, a power generation member stacked on the back side of the separator body of the first separator and including a power generation section having a membrane electrode assembly and a frame section surrounding the power generation section, and a second separator stacked on the back side of the power generation member and not including the front gasket or the back gasket, and the frame section has a back surface on which the fluid the frame-side flow path portion has a frame-side convex portion, and when viewed from the front-back direction, the frame-side convex portion overlaps with the front-side gasket and the back-side gasket of the first separator; the gas supplying method includes a preparation step of preparing the first separator, the power generation member, and the second separator; a stacking step of stacking the first separator, the power generation member, and the second separator in this order to produce the stack; and a fastening step of applying a fastening force to the stack from both sides in the stacking direction to produce the stack.

[0027] With this configuration, when viewed from the front-to-back direction (the stacking direction of the fuel cell stack), the frame-side convex portion of the frame-side flow path portion of the frame of the power generation member overlaps with the front-side gasket and rear-side gasket of the first separator. This simplifies the stacking process of the first separator, power generation member, and second separator. Furthermore, the shape stability of the stack can be improved after the fastening process.

[0028] Furthermore, with this configuration, the gaskets (front gasket and back gasket) are concentrated on the first separator. This improves the productivity and practicality of the fuel cell stack compared to when the gaskets are distributed across the first and second separators. Furthermore, because the gaskets are concentrated on the first separator, the flexibility in the material and shape of the second separator can be increased.

[0029] Furthermore, with this configuration, the frame section alone can provide the flow path section (frame-side flow path section), eliminating the need to provide a flow path section in the second separator, thereby simplifying the shape of the second separator.

[0030] (5) In order to solve the above-mentioned problems, the manufacturing method of a fuel cell stack of the present disclosure is a manufacturing method of a fuel cell stack including a stack of a plurality of cells, wherein the cells include a first separator manufactured by the manufacturing method of a separator with a double-sided gasket having any of the configurations (1) to (3) above, a power generation member stacked on the back side of the separator body of the first separator and including a power generation section having a membrane electrode assembly and a frame section surrounding the power generation section, and a second separator stacked on the back side of the power generation member and not including the front gasket or the back gasket, and the second separator has a surface on which the flow a second separator-side flow path portion through which a gas flows, the second separator-side flow path portion having a second separator-side convex portion, and the second separator-side convex portion overlaps with the front-side gasket and the back-side gasket of the first separator when viewed from the front-back direction; and the fuel cell stack has the following features: a preparation step of preparing the first separator, the power generation member, and the second separator; a stacking step of stacking the first separator, the power generation member, and the second separator in this order to produce the laminate; and a fastening step of applying a fastening force to the laminate from both sides in the stacking direction to produce the stack.

[0031] According to this configuration, when viewed from the front and back, the second separator-side convex portion of the second separator-side flow path portion of the second separator overlaps with the front and back gaskets of the first separator. This simplifies the lamination process of the first separator, the power generation member, and the second separator. Furthermore, this also improves the shape stability of the stack after the fastening process.

[0032] Furthermore, with this configuration, the gaskets (front gasket and back gasket) are concentrated on the first separator. This improves the productivity and practicality of the fuel cell stack compared to when the gaskets are distributed across the first and second separators. Furthermore, because the gaskets are concentrated on the first separator, the flexibility in the material and shape of the second separator can be increased.

[0033] Furthermore, with this configuration, the second separator alone can provide a flow path (second separator-side flow path), eliminating the need to provide a flow path in the power generation member, thereby simplifying the shape of the power generation member.

[0034] (6) In the configurations (4) and (5) above, it is preferable that the first separator, the power generation member, and the second separator are laminated in a non-adhered state during the lamination process. This configuration eliminates the need for a bonding process and a cleaning process before the bonding process. This improves the productivity and practicality of fuel cell stacks. [Effects of the Invention]

[0035] According to the manufacturing method of the separator and stack with double-sided gasket of the present disclosure, it is possible to manufacture a separator and stack with double-sided gasket that can protect the inner peripheral surface of a manifold. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 is an exploded perspective view of a separator with double-sided gaskets and a stack manufactured by a manufacturing method of a stack according to a first embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the stack of the second separator of the upper cell and the first separator of the lower cell. [Figure 3] FIG. 3 is an exploded perspective view of the cell. [Figure 4] FIG. 4 is a top view of the cell. [Figure 5] FIG. 5 is a top view of the separator body of the first separator. [Figure 6] FIG. 6 is a top view of the front gasket of the first separator. [Figure 7] FIG. 7 is a bottom view of the first separator. [Figure 8] FIG. 8 is a bottom view of the separator body. [Figure 9] FIG. 9 is a bottom view of the rear gasket of the first separator. [Figure 10] FIG. 10 is a top view of the second separator of the cell. [Figure 11] FIG. 11 is a bottom view of the cell. [Figure 12] FIG. 12 is a top view of the power generation member of the cell. [Figure 13] FIG. 13 is an enlarged view of the area within the frame XIII in FIG. [Figure 14] FIG. 14 is an enlarged view of the area within the frame XIII in FIG. [Figure 15] FIG. 15 is a cross-sectional view taken along the line XV-XV in FIGS. [Figure 16] FIG. 16 is a top view of the front gasket and the back gasket superimposed on each other. [Figure 17] FIG. 17 is an enlarged view of the area within the frame XIII in FIG. [Figure 18] FIG. 18 is a vertical cross-sectional view of a part of a mold in a placement step of an injection molding step in the method for producing the first separator. [Figure 19] FIG. 19 is a vertical cross-sectional view of a part of the mold in a raw material injection step of the injection molding process. [Figure 20] FIG. 20 is an enlarged view of the area enclosed by the frame XX in FIG. [Figure 21] FIG. 21 is a vertical cross-sectional view of a part of the mold during the curing step of the injection molding process. [Figure 22] FIG. 22 is a top view of the second separator of the cell of the second embodiment. [Figure 23]FIG. 23 is a bottom view of the power generation member of the cell. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, embodiments of the double-sided gasketed separator and the method for manufacturing the stack according to the present disclosure will be described.

[0038] First Embodiment FIG. 1 shows an exploded perspective view of a stack manufactured by the double-sided gasketed separator and stack manufacturing method of this embodiment. FIG. 2 shows an exploded perspective view of a laminated portion of the second separator of the upper cell and the first separator of the lower cell of the stack. FIG. 3 shows an exploded perspective view of the cell. The first separator 2 is included in the concept of the double-sided gasketed separator of the present disclosure. In FIGS. 1 to 3, the first concave-convex portion 201 of the first separator 2 and the second concave-convex portion 71 of the second separator 7 are shown in a simplified form.

[0039] [Stack 9] First, the configuration of the fuel cell stack 9 of this embodiment will be described. As shown in Fig. 1, the fuel cell stack 9 includes a pair of upper and lower end plates 90 and a plurality of cells 1. The plurality of cells 1 are stacked in the vertical direction. The pair of upper and lower end plates 90 sandwich a stack 91 of the plurality of cells 1 from above and below. The pair of upper and lower end plates 90 are connected by a pair of left and right tie rods (fastening members) 92 that pass through the rod insertion holes 202, 72 of all of the cells 1. A fastening force F is applied to the plurality of cells 1 from above and below (from the outside in the stacking direction).

[0040] The first separator 2, power generation member 6, and second separator 7 that make up the cell 1 are not bonded to each other. Any pair of cells 1 adjacent in the vertical direction are not bonded to each other. These members are positioned in the vertical direction by the above-mentioned fastening force F. In addition, these members are positioned in the planar direction (the layer-side direction of the stack 9, a direction perpendicular to the vertical direction) by tie rods 92.

[0041] [Flow path area] Next, the flow path areas defined between the layers of the stack 9 will be described.

[0042] {First gas flow area A1} 3, a first gas flow path area A1 is defined between the upper surface (front surface) of the power generation member 6 in any cell 1 and the lower surface (back surface) 20D of the separator body 20 of the first separator 2. Air L1 flows in the first gas flow path area A1.

[0043] {Second gas flow area A2} 2 and 3, a second gas flow path area A2 is defined between the lower surface of the power generation member 6 and the upper surface 7U of the second separator 7 in any cell 1. Hydrogen L2 flows in the second gas flow path area A2.

[0044] {Inter-separator flow area A3} 1 and 2, an inter-separator flow path area A3 is defined between a pair of cells 1 adjacent in the vertical direction (front-to-back direction, stacking direction) (specifically, between the lower surface 7D of the second separator 7 of the upper (front-side) cell 1 and the upper surface 20U of the separator body 20 of the first separator 2 of the lower (back-side) cell 1). A coolant L3 flows in the inter-separator flow path area A3.

[0045] [Cell 1] Next, the configuration of cell 1 will be described. FIG. 4 shows a top view of a cell of this embodiment (top view of the first separator). In FIG. 4, the front gasket is hatched with dotted lines. FIG. 5 shows a top view of the separator body of the first separator. FIG. 6 shows a top view of the front gasket of the first separator. FIG. 7 shows a bottom view of the first separator. In FIG. 7, the back gasket is hatched with dotted lines. FIG. 8 shows a bottom view of the separator body. FIG. 9 shows a bottom view of the back gasket of the first separator. FIG. 10 shows a top view of the second separator of the cell. FIG. 11 shows a bottom view of the cell (bottom view of the second separator). FIG. 12 shows a top view of the power generation member of the cell. Note that the bottom view of the power generation member is the same as the top view shown in FIG. 12. FIG. 13 shows an enlarged view of the area within frame XIII in FIG. 4. Figure 14 shows an enlarged view of the area within frame XIII in Figure 7. Figure 15 shows a cross-sectional view taken along the line XV-XV in Figures 13 and 14. Frame XIII in each figure indicates a common portion (the front left portion of cell 1).

[0046] As shown in FIG. 1, the cell 1 includes a power generation member 6, a first separator 2, and a second separator 7. The first separator 2 is stacked on the upper side of the power generation member 6. As shown in FIG. 2, a second separator 7 of another cell 1 (a cell 1 adjacent to the upper side of the first separator 2) is stacked on the upper side of the first separator 2. As shown in FIG. 1, the second separator 7 is stacked on the lower side of the power generation member 6. A first separator 2 of another cell 1 (a cell 1 adjacent to the lower side of the second separator 7) is stacked on the lower side of the second separator 7.

[0047] {First Separator 2} 2 to 9, the first separator 2 is provided with gaskets (a front gasket 5U and a back gasket 5D) on both the top and bottom surfaces. That is, the first separator 2 is a double-sided gasketed separator. The first separator 2 is provided with a separator body 20 and a gasket 5.

[0048] (Separator body 20) 5 and 8, the separator body 20 is a press-formed metal plate. The upper surface 20U and the lower surface 20D of the separator body 20 are symmetrical to each other. The separator body 20 includes six (plural) manifolds 20La-20Lc, 20Ra-20Rc, two (plural) gas flow holes 20Ld, 20Rd, a plurality of raw material flow holes 200, a first concave-convex portion 201, and two (plural) rod insertion holes 202.

[0049] (Manifold 20La~20Lc, 20Ra~20Rc) The manifolds 20La to 20Lc vertically penetrate the separator body 20. The manifolds 20La to 20Lc are arranged along the left edge of the separator body 20 from the front side to the rear side in the order of manifold 20La, manifold 20Lb, and manifold 20Lc.

[0050] The manifolds 20Ra to 20Rc vertically penetrate the separator body 20. The manifolds 20Ra to 20Rc are arranged along the right edge of the separator body 20 from the front side to the rear side in the order of manifold 20Ra, manifold 20Rb, and manifold 20Rc.

[0051] A predetermined fluid (coolant, gas) flows through the manifolds 20La to 20Lc and 20Ra to 20Rc. Specifically, as shown in Fig. 1, air (oxidizer gas) L1 flows through the manifolds 20La and 20Rc, a coolant L3 flows through the manifolds 20Lb and 20Rb, and hydrogen (fuel gas) L2 flows through the manifolds 20Lc and 20Ra.

[0052] (Gas flow holes 20Ld, 20Rd, raw material flow hole 200) As shown in Figures 5 and 8, the gas flow holes 20Ld, 20Rd penetrate the separator body 20 in the vertical direction. As shown in Figure 4, the gas flow hole 20Ld is located to the right of (inside in the planar direction) the manifold 20La, with a front-side flow path section 51U of a front-side gasket 5U (described later) sandwiched between them. The gas flow hole 20Rd is located to the left of (inside in the planar direction) the manifold 20Rc, with a front-side flow path section 51U of a front-side gasket 5U (described later) sandwiched between them. Air L1 flows through the gas flow holes 20Ld, 20Rd.

[0053] As will be described later, the gas flow holes 20Ld, 20Rd are arranged in the overlapping portion B between the surrounding portions shown in Fig. 15. The gas flow holes 20Ld, 20Rd vertically connect the front-side manifold surrounding portion 520U around the manifolds 20La, 20Rc on the upper side of the first separator 2 with the first gas flow path area surrounding portion 521D on the lower side of the first separator 2 (see Figs. 2 and 3).

[0054] 5 and 8, the plurality of raw material flow holes 200 penetrate the separator body 20 in the vertical direction. The plurality of raw material flow holes 200 are arranged around the first concave-convex portion 201. As shown by dotted lines in FIGS. 4 and 7, the plurality of raw material flow holes 200 overlap with the front gasket 5U and the back gasket 5D when viewed from the vertical direction (in a plan view).

[0055] (First uneven portion 201, rod insertion hole 202) 5 and 8, the first concave-convex portion 201 is disposed in the center of the separator body 20 in the planar direction. The first concave-convex portion 201 includes a plurality of groove-shaped recesses extending in the left-right direction and a plurality of rib-shaped protrusions extending in the left-right direction. The recesses and protrusions are alternately disposed in the front-rear direction.

[0056] 5 and 8, the two rod insertion holes 202 extend vertically through the separator body 20. The two rod insertion holes 202 are located near both left and right edges of the separator body 20.

[0057] (Gasket 5) As shown in Figures 6, 9, and 15, the gasket 5 is a one-piece member made of EPDM (ethylene propylene diene rubber, an elastomer). The gasket 5 includes a front gasket 5U, a rear gasket 5D, and a plurality of covering portions 5M. The front gasket 5U, rear gasket 5D, and a plurality of covering portions 5M are integrally connected. The front gasket 5U, rear gasket 5D, and a plurality of covering portions 5M are made of the same elastomer.

[0058] (Front gasket 5U) 4 and 6, the front gasket 5U is disposed on the upper surface 20U of the separator body 20. The front gasket 5U includes a front base layer 50U, six (a plurality of) front flow path portions 51U, a front seal portion 52U, and a plurality of front abutment holes 53U (see FIGS. 13 and 15). The six front flow path portions 51U and the front seal portion 52U are integrally connected via the front base layer 50U.

[0059] (Top side base layer 50U, front side channel part 51U) The front-side base layer 50U is a thin film and is laminated on the upper surface 20U of the separator body 20. Six front-side flow path sections 51U are formed on the upper surface of the front-side base layer 50U. The six front-side flow path sections 51U are arranged corresponding to the manifolds 20La to 20Lc and 20Ra to 20Rc. A predetermined fluid flows through the front-side flow path sections 51U.

[0060] 1, of the three surface-side passage sections 51U near the manifolds 20La to 20Lc, air L1 flows through the surface-side passage section 51U to the right of manifold 20La, coolant L3 flows through the surface-side passage section 51U to the right of manifold 20Lb, and hydrogen L2 flows through the surface-side passage section 51U to the right of manifold 20Lc. Of the three surface-side passage sections 51U near the manifolds 20Ra to 20Rc, hydrogen L2 flows through the surface-side passage section 51U to the left of manifold 20Ra, coolant L3 flows through the surface-side passage section 51U to the left of manifold 20Rb, and air L1 flows through the surface-side passage section 51U to the left of manifold 20Rc.

[0061] As shown in Figures 4, 6, 13, and 15, the front-side flow passage section 51U includes a plurality of front-side protrusions 510U and a plurality of front-side grooves 511U. The front-side protrusions 510U protrude upward from the front-side base layer 50U. The front-side protrusions 510U are arranged side by side at predetermined intervals in the front-rear direction. The front-side protrusions 510U are rib-shaped and extend in the left-right direction.

[0062] The front-side groove 511U is defined between a pair of front-side protrusions 510U adjacent to each other in the front-rear direction. The front-side groove 511U extends in the left-right direction. As described above, a predetermined fluid (air L1, hydrogen L2, coolant L3) flows through the front-side groove 511U.

[0063] (Front seal part 52U) As shown in Figures 4 (cross-hatched portion), 6, 13 (cross-hatched portion), and 15, the front seal portion 52U is formed on the upper surface of the front base layer 50U. The front seal portion 52U protrudes upward from the front base layer 50U. The front seal portion 52U includes four (a plurality of) front manifold enclosures 520U and an inter-separator flow path area enclosure 521U.

[0064] 4, 6, and 13, the four front-side manifold enclosures 520U are arranged to correspond to the manifolds 20La, 20Lc, 20Ra, and 20Rc at the four corners of the separator body 20. Specifically, the front-side manifold enclosure 520U at the left front corner, when viewed from the top-bottom direction, surrounds, in an endless annular shape, the manifold 20La, the front-side flow path section 51U located to the right of the manifold 20La, and the gas flow hole 20Ld located to the right of the front-side flow path section 51U. The front-side manifold enclosure 520U at the left rear corner, when viewed from the top-bottom direction, surrounds, in an endless annular shape, the manifold 20Lc and the front-side flow path section 51U located to the right of the manifold 20Lc.

[0065] Furthermore, the front-side manifold enclosure 520U at the front right corner surrounds, in an endless ring shape, the manifold 20Ra and the front-side flow path section 51U located to the left of the manifold 20Ra when viewed from the top-bottom direction. The front-side manifold enclosure 520U at the rear right corner surrounds, in an endless ring shape, the manifold 20Rc, the front-side flow path section 51U located to the left of the manifold 20Rc, and the gas flow hole 20Rd located to the left of the front-side flow path section 51U when viewed from the top-bottom direction.

[0066] As shown in Figures 4 and 6, when viewed from the top and bottom, the inter-separator flow path area surrounding portion 521U surrounds, in an endless ring shape, the manifold 20Lb of the separator main body 20, the front-side flow path portion 51U to the right of the manifold 20Lb, the manifold 20Rb, the front-side flow path portion 51U to the left of the manifold 20Rb, and the first uneven portion 201 (inter-separator flow path area A3).

[0067] (Front side contact hole 53U) 13 and 15, the front contact hole 53U penetrates the front gasket 5U (specifically, the front base layer 50U) in the vertical direction. The front contact hole 53U reaches the upper surface 20U of the separator body 20. The front contact hole 53U has a slit shape that is long in the front-rear direction. As shown in FIG. 18, which will be described later, the front contact hole 53U is a contact mark of the front contact portion 800U of the upper mold 8U when molding the gasket 5, which will be described later.

[0068] (Backside gasket 5D) 7 and 9, the back gasket 5D is disposed on the lower surface 20D of the separator body 20. The back gasket 5D includes a back base layer 50D, two (or more) back flow path portions 51D, a back seal portion 52D, and a plurality of back abutment holes 53D (see FIGS. 14 and 15). The two back flow path portions 51D and the back seal portion 52D are integrally connected via the back base layer 50D.

[0069] (Backside base layer 50D, backside flow path portion 51D) The back-side base layer 50D is a thin film and is laminated on the lower surface 20D of the separator body 20. Two back-side flow path portions 51D are formed on the lower surface of the back-side base layer 50D. The two back-side flow path portions 51D are arranged on both the left and right sides of the first concave-convex portion 201. Air L1 flows through the back-side flow path portions 51D.

[0070] As shown in Figures 7, 9, 14, and 15, the back-side flow path section 51D includes a plurality of back-side convex sections 510D and a plurality of back-side groove sections 511D. The back-side convex sections 510D protrude downward from the back-side base layer 50D. The multiple back-side convex sections 510D are arranged side by side at predetermined intervals in the front-rear direction. The back-side convex sections 510D are rib-shaped and extend in the left-right direction.

[0071] The rear-side groove 511D is defined between a pair of rear-side protrusions 510D adjacent to each other in the front-rear direction. The rear-side groove 511D extends in the left-right direction. As described above, air L1 flows through the rear-side groove 511D.

[0072] (Backside seal part 52D) As shown in Figures 7 (cross-hatched portion), 9, 14 (cross-hatched portion), and 15, the back seal portion 52D is formed on the lower surface of the back base layer 50D. The back seal portion 52D protrudes downward from the back base layer 50D. The back seal portion 52D includes six (plural) back manifold enclosures 520D, a first gas flow path area enclosure 521D, and a total gas flow path area enclosure 522D.

[0073] 7, 9, and 14, the six rear-side manifold enclosing portions 520D are arranged to correspond to the six manifolds 20La to 20Lc and 20Ra to 20Rc of the separator body 20. When viewed from the top-bottom direction, the six rear-side manifold enclosing portions 520D surround the manifolds 20La to 20Lc and 20Ra to 20Rc, respectively, in an endless annular shape.

[0074] As shown in Fig. 7, the first gas flow path area enclosure 521D, when viewed from the top and bottom, surrounds the first gas flow path area A1, the two back-side flow path sections 51D, and the two gas flow holes 20Ld, 20Rd in an endless annular shape. As shown in Figs. 3 and 15, the first gas flow path area enclosure 521D is in elastic contact (pressure contact) with the upper surface of a frame section 61 of the power generation member 6, which will be described later. The first gas flow path area A1 is disposed above the frame section 61 shown in Fig. 15, and the second gas flow path area A2 is disposed below it. The first gas flow path area enclosure 521D seals the first gas flow path area A1.

[0075] As shown in FIGS. 13 to 15, in a single cell 1, an overlapping portion B between the upper surface 20U and the lower surface 20D of the separator body 20 of the first separator 2 is set when viewed from the top-bottom direction.

[0076] Specifically, an overlapping portion B between the surrounding portions is set between the front manifold surrounding portion 520U around the manifolds 20La, 20Rc on the upper surface 20U of the separator body 20 and the first gas flow path area surrounding portion 521D on the lower surface 20D of the separator body 20.

[0077] At the overlapping portion B between the surrounding portions, a portion of the internal space 520Ua of the front-side manifold surrounding portion 520U and a portion of the internal space 521Da of the first gas flow path area surrounding portion 521D overlap. The gas flow holes 20Ld and 20Rd of the separator body 20 are arranged at the overlapping portion B. The gas flow holes 20Ld and 20Rd communicate the internal space 520Ua of the front-side manifold surrounding portion 520U with the internal space 521Da of the first gas flow path area surrounding portion 521D.

[0078] 7, 9, and 15, the comprehensive gas flow path area enclosure 522D is disposed on the planar outer side of the first gas flow path area enclosure 521D and the second gas flow path area enclosure 721U on the upper surface 7U of the second separator 7 (described later in FIG. 10). The comprehensive gas flow path area enclosure 522D is disposed on the planar outer side of the frame 61 of the power generation member 6 (described later). When viewed from the top-bottom direction, the comprehensive gas flow path area enclosure 522D surrounds the first gas flow path area A1 in an endless annular shape from the planar outer side of the first gas flow path area enclosure 521D. That is, the first gas flow path area A1 is sealed in a double annular shape by the inner first gas flow path area enclosure 521D and the outer comprehensive gas flow path area enclosure 522D.

[0079] 3 and 15, the comprehensive gas flow path area enclosure 522D is in elastic contact (pressure contact) with the upper surface 7U of the second separator 7. When viewed from the top-bottom direction, the comprehensive gas flow path area enclosure 522D surrounds the second gas flow path area A2 in an endless ring shape from the outer side in the planar direction of the second gas flow path area enclosure 721U. That is, the second gas flow path area A2 is sealed in a double ring shape by the inner second gas flow path area enclosure 721U and the outer comprehensive gas flow path area enclosure 522D.

[0080] (Back side contact hole 53D) As shown in Figures 14 and 15, the back-side contact hole 53D penetrates the back-side gasket 5D (specifically, the back-side base layer 50D) in the vertical direction. The back-side contact hole 53D reaches the lower surface 20D of the separator body 20. The back-side contact hole 53D has a slit shape that is long in the front-rear direction. As shown in Figure 18, which will be described later, the back-side contact hole 53D is a contact mark of the back-side contact portion 800D of the lower mold 8D during molding of the gasket 5, which will be described later.

[0081] When viewed from the top-bottom direction, the front-side contact hole 53U and the rear-side contact hole 53D overlap each other. That is, the front-side contact hole 53U and the rear-side contact hole 53D face each other in the top-bottom direction with the separator body 20 sandwiched therebetween.

[0082] (Coated part 5M) As shown in Figures 4, 6, 7, 9, and 13 to 15, multiple covering portions 5M are laminated on the inner circumferential surfaces of the manifolds 20La-20Lc and 20Ra-20Rc and the gas flow holes 20Ld and 20Rd of the separator body 20. The covering portions 5M completely cover the inner circumferential surfaces of the holes (manifolds 20La-20Lc, 20Ra-20Rc, gas flow holes 20Ld and 20Rd). The covering portions 5M are integrally connected to the front base layer 50U and the back base layer 50D.

[0083] (Regarding overlap between front gasket 5U and rear gasket 5D) Fig. 16 shows a top view of the front gasket and the back gasket overlapping each other. Fig. 17 shows an enlarged view of the area within frame XIII in Fig. 16. In Fig. 16, for ease of explanation of the overlapping portion B between the surrounding portions, the gas flow holes 7Ld, 7Rd of the second separator 7 are indicated by dashed lines.

[0084] (Overall shape) 16 and 17, when viewed from the top and bottom, the outer edge 5Ua of the front gasket 5U (specifically, the outer edge of the front base layer 50U) overlaps with the outer edge 5Da of the back gasket 5D (specifically, the outer edge 5Da of the back base layer 50D). Also, the inner edge 5Ub of the front gasket 5U (specifically, the inner edge of the front base layer 50U) overlaps with the inner edge 5Db of the back gasket 5D (specifically, the inner edge of the back base layer 50D). Thus, the silhouettes of the front gasket 5U and the back gasket 5D overlap.

[0085] (Regarding partial shapes) As shown by dotted hatching in Figures 16 and 17, when viewed from the top-bottom direction, multiple gasket overlap portions O are arranged between the front convex portion 510U of the front flow path portion 51U of the front gasket 5U on the upper side of the first separator 2 and the back seal portion 52D (back manifold enclosure portion 520D, first gas flow path area enclosure portion 521D, total gas flow path area enclosure portion 522D) of the back gasket 5D on the lower side of the first separator 2.

[0086] Similarly, when viewed from the top-bottom direction, multiple gasket overlap portions O are arranged between the front seal portion 52U (front manifold enclosure portion 520U, inter-separator flow path area enclosure portion 521U) of the front gasket 5U on the upper side of the first separator 2 and the back convex portion 510D of the back flow path portion 51D of the back gasket 5D on the lower side of the first separator 2.

[0087] Similarly, when viewed from the top-bottom direction, multiple gasket overlap portions O are arranged between the front seal portion 52U of the front gasket 5U on the upper side of the first separator 2 and the back seal portion 52D of the back gasket 5D on the lower side of the first separator 2.

[0088] Similarly, when viewed from the top-bottom direction, multiple gasket overlap portions O are arranged between the top-side convex portion 510U of the top-side flow path portion 51U of the top-side gasket 5U on the upper side of the first separator 2 and the back-side convex portion 510D of the back-side flow path portion 51D of the back-side gasket 5D on the lower side of the first separator 2.

[0089] In this way, the gasket overlap portions O are arranged between the front-side convex portion 510U and the back-side seal portion 52D, between the front-side seal portion 52U and the back-side convex portion 510D, between the front-side seal portion 52U and the back-side seal portion 52D, and between the front-side convex portion 510U (front-side flow path portion 51U) and the back-side convex portion 510D (back-side flow path portion 51D). In the gasket overlap portions O, the parts (elastomers) of the gaskets 5 are stacked in the vertical direction, sandwiching the separator body 20. In the stack 9 shown in FIG. 1, the gasket overlap portions O of all the cells 1 are stacked in the vertical direction.

[0090] {Second Separator 7} As shown in Fig. 1, the second separator 7 is stacked below (on the back side of) the separator body 20 of the first separator 2, with the power generation member 6 interposed therebetween. Also, as shown in Fig. 2, the second separator 7 is stacked above the separator body 20 of the first separator 2 of another cell 1 (the cell 1 adjacent to the lower side of the cell 1 including the second separator 7).

[0091] 10 and 11, the second separator 7 is made of resin and has a thin plate shape. The second separator 7 does not have a gasket 5 (see FIGS. 6 and 9). The second separator 7 corresponds to the separator body 20 of the first separator 2. The second separator 7 includes six (plural) manifolds 7La-7Lc, 7Ra-7Rc, two (plural) gas flow holes 7Ld, 7Rd, a second uneven portion 71, two (plural) rod insertion holes 72, two (plural) second separator-side flow path portions 73U, and a second gas flow path area surrounding portion 721U.

[0092] (Manifolds 7La~7Lc, 7Ra~7Rc) The manifolds 7La to 7Lc vertically penetrate the second separator 7. The manifolds 7La to 7Lc are arranged along the left edge of the second separator 7 from the front side to the rear side in the order of manifold 7La, manifold 7Lb, and manifold 7Lc.

[0093] The manifolds 7Ra to 7Rc penetrate the second separator 7 in the vertical direction. The manifolds 7Ra to 7Rc are arranged in the following order from the front to the rear along the right edge of the second separator 7: manifold 7Ra, manifold 7Rb, manifold 7Rc. A predetermined fluid flows through the manifolds 7La to 7Lc and 7Ra to 7Rc.

[0094] The manifold 7La is connected to the manifold 20La of the first separator 2, the manifold 7Lb is connected to the manifold 20Lb of the first separator 2, the manifold 7Lc is connected to the manifold 20Lc of the first separator 2, the manifold 7Ra is connected to the manifold 20Ra of the first separator 2, the manifold 7Rb is connected to the manifold 20Rb of the first separator 2, and the manifold 7Rc is connected to the manifold 20Rc of the first separator 2 in the vertical direction.

[0095] (Gas flow holes 7Ld, 7Rd) As shown in Figures 10 and 11, the gas flow holes 7Ld and 7Rd penetrate the second separator 7 in the vertical direction. The gas flow hole 7Ld is located to the right of the manifold 7Lc. The gas flow hole 7Rd is located to the left of the manifold 7Ra. Hydrogen L2 flows through the gas flow holes 7Ld and 7Rd.

[0096] Similar to the overlapping portion B between the surrounding portions within a single cell 1 shown in Figures 13 to 15, between a pair of adjacent cells 1 in the vertical direction, an overlapping portion B between the surrounding portions is set between the upper surface 20U of the separator body 20 of the first separator 2 of the lower cell 1 and the lower surface 20D of the separator body 20 of the first separator 2 of the upper cell 1.

[0097] Specifically, an overlapping portion B is defined between the front-side manifold enclosure 520U (see FIG. 2) around the manifolds 20Lc and 20Ra on the upper surface 20U of the first separator 2 of the lower cell 1 and the overall gas flow path area enclosure 522D (more specifically, the second gas flow path area enclosure 721U on the upper surface 7U of the second separator 7) on the lower surface 20D of the first separator 2 of the upper cell 1 (see FIG. 3), via the second separator 7 and the power generation member 6. As shown in FIG. 16, the gas flow holes 7Ld and 7Rd of the second separator 7 are disposed in the overlapping portion B. The gas flow holes 7Ld and 7Rd connect the internal space 520Ua of the front-side manifold enclosure 520U to the internal space of the second gas flow path area enclosure 721U.

[0098] (Second uneven portion 71, rod insertion hole 72) The second uneven portion 71 is disposed in the center of the second separator 7 in the planar direction. The configuration of the second uneven portion 71 is similar to the configuration of the first uneven portion 201 of the first separator 2. The two rod insertion holes 72 penetrate the second separator 7 in the vertical direction. The two rod insertion holes 72 are disposed near both left and right edges of the second separator 7. The rod insertion holes 72 are connected in the vertical direction to the rod insertion holes 202 of the first separator 2. In the stack 9 shown in FIG. 1 , a tie rod 92 is inserted through the rod insertion holes 72, 202 of a plurality of cells 1 connected in the vertical direction.

[0099] (Second separator side flow path portion 73U) As shown in FIG. 10, two second separator-side flow paths 73U are formed on the upper surface 7U of the second separator 7. The second separator-side flow paths 73U include a plurality of second separator-side convex portions 730U and a plurality of second separator-side groove portions 731U. The second separator-side convex portions 730U protrude upward from the upper surface 7U of the second separator 7. The plurality of second separator-side convex portions 730U are arranged side by side at predetermined intervals in the front-rear direction. The second separator-side convex portions 730U are rib-shaped and extend in the left-right direction.

[0100] The second separator groove 731U is defined between a pair of second separator protrusions 730U adjacent to each other in the front-rear direction. The second separator groove 731U extends in the left-right direction. As shown in FIG. 3, hydrogen L2 flows in the second separator groove 731U.

[0101] (Second gas flow path area enclosure 721U) As shown in Fig. 10, a second gas flow path area enclosure 721U is formed on the upper surface 7U of the second separator 7. When viewed from the top and bottom, the second gas flow path area enclosure 721U has an endless annular shape and surrounds the second gas flow path area A2, the two second separator-side flow path sections 73U, and the two gas flow holes 7Ld, 7Rd. As shown in Fig. 15, the second gas flow path area enclosure 721U is in pressure contact with the lower surface of a frame section 61 of the power generation member 6, which will be described later.

[0102] 15, a first gas flow path area A1 is disposed on the upper side and a second gas flow path area A2 is disposed on the lower side. The second gas flow path area enclosure 721U seals the second gas flow path area A2.

[0103] When viewed from the top-bottom direction, the first gas flow path area enclosure 521D and the second gas flow path area enclosure 721U overlap each other. That is, the first gas flow path area enclosure 521D and the second gas flow path area enclosure 721U face each other in the top-bottom direction with the frame portion 61 interposed therebetween.

[0104] 10 and 11, the second separator-side flow path section 73U and the second gas flow path area surrounding section 721U on the upper surface 7U are not disposed on the lower surface 7D of the second separator 7. Thus, the upper surface 7U and the lower surface 7D have different shapes. Furthermore, the upper surface 7U and the lower surface 7D are not symmetrical to each other.

[0105] {Power Generation Components 6} As shown in Figs. 1 and 3, the power generation member 6 is disposed between the lower surface 20D of the separator body 20 of the first separator 2 and the upper surface 7U of the second separator 7. As shown in Fig. 12, the power generation member 6 includes a power generation section 60 and a frame section 61. Note that Fig. 12 shows the shape of the upper surface of the power generation member 6. The shape of the lower surface of the power generation member 6 is the same as the shape of the upper surface.

[0106] The power generation unit 60 is disposed between the upper first gas flow path area A1 and the lower second gas flow path area A2. The power generation unit 60 includes an MEA (Membrane Electrode Assembly) and a pair of gas diffusion layers. The pair of gas diffusion layers are laminated on both the upper and lower surfaces of the MEA. The MEA includes an electrolyte membrane and a pair of catalyst layers. The pair of catalyst layers are laminated on both the upper and lower surfaces of the electrolyte membrane. The frame unit 61 is made of resin and surrounds the power generation unit 60 when viewed from above and below.

[0107] [Fluid flow path] Next, the flow paths of the fluids (air L1, hydrogen L2, coolant L3) in the fuel cell stack 9 of this embodiment will be briefly described.

[0108] As shown in Figures 1 to 3, air L1 flows inside the cell 1 in the following order: manifold 20La at the front left corner → front side flow path section 51U at the front left corner → gas flow hole 20Ld on the left side (from top to bottom) → back side flow path section 51D on the left side → first gas flow path area A1 → back side flow path section 51D on the right side → gas flow hole 20Rd on the right side (from bottom to top) → front side flow path section 51U at the rear right corner → manifold 20Rc at the rear right corner.

[0109] Hydrogen L2 flows inside the cell 1 in the following order: manifold 20Ra at the front right corner → front side flow path section 51U at the front right corner → gas flow hole 7Rd on the right side (from bottom to top) → second separator side flow path section 73U on the right side → second gas flow path area A2 → second separator side flow path section 73U on the left side → gas flow hole 7Ld on the left side (from top to bottom) → front side flow path section 51U at the rear left corner → manifold 20Lc at the rear left corner.

[0110] The coolant L3 flows between a pair of adjacent cells 1 in the vertical direction in the following order: left center manifold 20Lb → left center front side flow path section 51U → inter-separator flow path area A3 → right center front side flow path section 51U → right center manifold 20Rb.

[0111] In this way, the air L1 and hydrogen L2 flow three-dimensionally through the gas flow holes 20Ld, 20Rd, 7Ld, and 7Rd on both the upper and lower sides of the separator body 20. The coolant L3 flows two-dimensionally between a pair of adjacent cells 1.

[0112] [Stack 9 manufacturing method] Next, a method for manufacturing the fuel cell stack 9 of this embodiment will be described. The method for manufacturing the stack 9 includes a preparation step, a stacking step, and a fastening step.

[0113] {Preparation process} In the preparation step, the first separator 2, the power generation member 6, and the second separator 7 are prepared. Of these, the power generation member 6 and the second separator 7 are each appropriately procured by means of purchase, manufacturing, or the like. For example, the second separator 7 made of resin is molded by injection molding. On the other hand, the first separator 2 is manufactured by the following manufacturing method. The manufacturing method of the first separator 2 includes a press molding step and an injection molding step.

[0114] (press molding process) In the press molding process, separator body 20 shown in Figures 5 and 8 is produced from a flat metal plate by press molding. Upper surface 20U and lower surface 20D of separator body 20 have shapes that are symmetrical to each other. For example, when focusing on the uneven shape of first uneven portion 201, the convex portions on the upper surface 20U side correspond to the concave portions on the lower surface 20D side, and the concave portions on the upper surface 20U side correspond to the convex portions on the lower surface 20D side.

[0115] (injection molding process) In the injection molding process, a mold is used to integrally mold the gasket 5 with the separator body 20. The injection molding process includes a manifold selection process, a placement process, a raw material injection process, and a curing process.

[0116] Fig. 18 shows a vertical cross-sectional view of a portion of a mold in a placement step of an injection molding step in a manufacturing method for a first separator of this embodiment (included in the preparation step of a manufacturing method for a stack of this embodiment). Fig. 19 shows a vertical cross-sectional view of a portion of a mold in a raw material injection step of the same injection molding step. Fig. 20 shows an enlarged view of the area within box XX in Fig. 19. Fig. 21 shows a vertical cross-sectional view of a portion of a mold in a curing step of the same injection molding step.

[0117] 18 to 21 correspond to the portion shown in FIG. 15. That is, the portion of the mold corresponds to the portion within frame XIII shown in FIGS. 4, 7, 13, and 14. In FIGS. 18 to 21, the reference numerals for the cavities are the reference numerals for the gaskets molded by the cavities with the letter "c" added. For example, the reference numeral "5c" for gasket cavity 5c is the reference numeral "5" for the gasket 5 molded by the gasket cavity 5c with the letter "c" added.

[0118] (Molds used in the injection molding process 8) First, the configuration of the mold 8 used in the injection molding process will be described. As shown in Figures 18 to 21, the mold 8 includes an upper mold (movable mold) 8U, a lower mold (fixed mold) 8D, and a gasket cavity 5c. The gasket cavity 5c is included in the concept of "cavity" in this disclosure.

[0119] (upper mold 8U) The upper mold 8U has a mold surface 80U facing downward (toward the lower mold 8D) and a plurality of front-side contact portions 800U. The front-side contact portions 800U protrude downward from the mold surface 80U. As shown in FIGS. 19 and 20, in the mold-closed state, the front-side contact portions 800U are disposed in front-side gasket cavities 5Uc, which will be described later. In the mold-closed state, the front-side contact portions 800U abut against the upper surface 20U of the separator body 20.

[0120] (Lower mold 8D) The lower mold 8D has an upward-facing mold surface 80D (facing the upper mold 8U) and a plurality of backside contact portions 800D. The backside contact portions 800D protrude upward from the mold surface 80D. As shown in FIGS. 19 and 20, in the mold-closed state, the backside contact portions 800D are disposed in backside gasket cavities 5Dc, which will be described later. In the mold-closed state, the backside contact portions 800D abut against the lower surface 20D of the separator body 20.

[0121] When viewed from the top-bottom direction, the front contact portion 800U and the rear contact portion 800D overlap with each other. The front contact portion 800U and the rear contact portion 800D face each other in the top-bottom direction, with the separator body 20 sandwiched between them.

[0122] (Gasket cavity 5c) 19 and 20, the gasket cavity 5c is defined between the upper mold 8U and the lower mold 8D in the mold clamped state. The gasket cavity 5c includes a plurality of covering portion cavities 5Mc, a front gasket cavity 5Uc, a rear gasket cavity 5Dc, and a plurality of gate cut portion cavities Sc. The gasket cavities 5c are integrally connected.

[0123] (Cavity 5Mc for coated part, cavity Sc for gate cut part) 20 and 21, the inner circumferential surfaces of a plurality of openings (specifically, manifolds 20La-20Lc, 20Ra-20Rc, and gas flow holes 20Ld, 20Rd) of the separator body 20 are exposed to the cavity 5Mc for the covering portion. The covering portion 5M is molded in the cavity 5Mc for the covering portion.

[0124] The gate cut portion cavity Sc is connected to the radially inner side of the covering portion cavity 5Mc. In the gate cut portion cavity Sc, a gate cut portion (scrap) S is formed. After the hardening process, the gate cut portion S is cut out from the covering portion cavity 5Mc.

[0125] (Front gasket cavity 5Uc) 19 to 21, the front gasket 5U is molded in the front gasket cavity 5Uc. The front gasket cavity 5Uc includes a front base layer cavity 50Uc, six (plural) front flow path portion cavities, and a front seal portion cavity 52Uc.

[0126] The cavity 50Uc for the front base layer is the portion of the cavity 5Uc for the front gasket that has the narrowest vertical width. The upper surface 20U of the separator body 20 is exposed to the cavity 50Uc for the front base layer. The cavity 50Uc for the front base layer is where the front base layer 50U is molded.

[0127] The front-side seal cavity 52Uc includes four (a plurality of) front-side manifold enclosure cavities 520Uc and an inter-separator flow path area enclosure cavity 521Uc. The front-side manifold enclosure 520U is molded in the front-side manifold enclosure cavity 520Uc, and the inter-separator flow path area enclosure cavity 521U is molded in the inter-separator flow path area enclosure cavity 521Uc. Similarly, the front-side flow path cavity 51U shown in FIG. 4 is molded.

[0128] (Backside gasket cavity 5Dc) 19 to 21, a back gasket 5D is molded in a back gasket cavity 5Dc. The back gasket cavity 5Dc includes a back base layer cavity 50Dc, two (plural) back flow path portion cavities, and a back seal portion cavity 52Dc.

[0129] The cavity 50Dc for the backside base layer is the narrowest portion of the cavity 5Dc for the backside gasket in the vertical direction. The underside 20D of the separator body 20 is exposed in the cavity 50Dc for the backside base layer. The cavity 50Dc for the backside base layer is where the backside base layer 50D is molded. When viewed from the vertical direction, the cavity 50Uc for the frontside base layer and the cavity 50Dc for the backside base layer overlap each other.

[0130] The back-side seal cavity 52Dc includes six (plural) back-side manifold enclosure cavities 520Dc, a first-gas flow path area enclosure cavity 521Dc, and a comprehensive gas flow path area enclosure cavity 522Dc. The back-side manifold enclosure 520Dc is molded in the back-side manifold enclosure cavity 520Dc, the first-gas flow path area enclosure cavity 521Dc is molded in the first-gas flow path area enclosure cavity 521D, and the comprehensive gas flow path area enclosure cavity 522Dc is molded in the comprehensive gas flow path area enclosure cavity 522D. Similarly, the back-side flow path cavity 51D shown in FIG. 7 is molded.

[0131] (Details of the injection molding process) Next, the injection molding process will be described. As described above, the injection molding process includes a manifold selection process, a placement process, a raw material injection process, and a curing process.

[0132] (Manifold selection process) In the manifold selection step, an opening to be used for injecting raw material E is selected from the multiple openings of separator body 20 (specifically, manifolds 20La-20Lc, 20Ra-20Rc, gas flow holes 20Ld, 20Rd, and multiple raw material flow holes 200) depending on the fluidity of raw material E. Note that raw material E used in this embodiment is EPDM. EPDM has lower fluidity than silicone rubber, etc. For this reason, in this step, all openings are selected for injecting raw material E.

[0133] (Placement process) In the placement step, first, the separator body 20 is placed inside the mold 8 in an open state so that the gates G of the mold 8 face the openings selected in the manifold selection step, as shown in Fig. 18. In Fig. 4, the positions of the gates G when viewed from above and below are indicated by dotted lines.

[0134] An adhesive is applied in advance to the gasket molding portion of the separator body 20 (the portion where the gasket 5 is molded). Next, as shown in FIG. 19, the upper mold 8U is brought into contact with the lower mold 8D, thereby clamping the mold 8. The mold 8 switches from an open state to a clamped state. As shown in FIG. 20, in the clamped state, the front contact portion 800U is in contact with the upper surface 20U of the separator body 20, and the back contact portion 800D is in contact with the lower surface 20D of the separator body 20.

[0135] (Raw material injection process) In the raw material injection process, as shown in FIGS. 19 and 20, raw material E is injected from multiple gates G into multiple openings to fill the gasket cavity 5c. As an example, in manifolds 20La-20Lc and 20Ra-20Rc among the multiple openings, raw material E is injected from the gate G through the gate cut portion cavity Sc into the covering portion cavity 5Mc. Starting from the covering portion cavity 5Mc, the raw material E is diverted into the front gasket cavity 5Uc and the back gasket cavity 5Dc. The diverted raw material E is filled into the front gasket cavity 5Uc and the back gasket cavity 5Dc.

[0136] As described above, the front contact portion 800U contacts the upper surface 20U of the separator body 20, and the back contact portion 800D contacts the lower surface 20D of the separator body 20. This prevents deformation of the separator body 20 due to the injection pressure of the raw material E, etc. This prevents changes in the volume of the front gasket cavity 5Uc and the back gasket cavity 5Dc.

[0137] The raw material E is also injected from the gate G into the plurality of openings other than the manifolds 20La to 20Lc and 20Ra to 20Rc, in the same manner as the manifolds 20La to 20Lc and 20Ra to 20Rc.

[0138] (hardening process) In the curing step, first, the mold 8 is heated with a predetermined temperature pattern (heating temperature, heating time) as shown in Fig. 21 to cure the raw material E. Next, the mold 8 is switched from a clamped state to an open state, and the first separator 2 is removed from the mold 8. Thereafter, the gate cut portion S is cut off from the covering portion 5M.

[0139] {Lamination process, fastening process} In the stacking step, as shown in FIG. 1, the first separator 2, the power generation member 6, and the second separator 7 are stacked vertically in this order to produce the cell 1 and a laminate 91 at the same time.

[0140] In the fastening process, first, as shown in FIG. 1, a pair of end plates 90 are placed on both the top and bottom sides of the stack 91. Next, a pair of left and right tie rods 92 are inserted into the rod insertion holes 202, 72 of all the cells 1, respectively. Then, a fastening force F is applied to the stack 91 from both the top and bottom sides. In this manner, the stack 9 is produced.

[0141] [Action and effect] Next, the effects of the first separator 2 (double-sided gasketed separator) and the cell 1 of this embodiment will be described, as well as the effects of the method for manufacturing the first separator 2 and the stack 9 of this embodiment.

[0142] (Actions and Effects of First Separator 2 and Cell 1) First, we will explain the effects of the first separator 2 and the cell 1. As shown in Figures 4 and 7, gaskets 5 (front gasket 5U, back gasket 5D) are concentrated on both the top and bottom surfaces of the separator body 20 of a single separator (first separator 2). This improves the productivity and practicality of the fuel cell stack 9 compared to when the gaskets 5 are dispersed among multiple separators (first separator 2, second separator 7).

[0143] Furthermore, because the gaskets 5 are concentrated in the first separator 2, there is no need to consider the placement of the gaskets when designing the second separator 7. This allows for greater freedom in the material and shape of the second separator 7. For example, the second separator 7 can be made of resin. Furthermore, as shown in FIGS. 10 and 11, the upper surface 7U and the lower surface 7D of the second separator 7 can have different shapes. For example, the second separator-side flow path section 73U can be disposed only on the upper surface 7U.

[0144] As shown in Figures 5 and 8, the separator body 20 is a press-molded product. Therefore, the shapes of the upper surface 20U and the lower surface 20D are exactly symmetrical. This places great restrictions on the shape. Furthermore, in order to place the gasket 5 on the separator body 20, it is necessary to ensure that the upper surface 20U and the lower surface 20D of the separator body 20 each have a flat portion.

[0145] Thus, when arranging the gasket 5 on the separator body 20, which is a press-molded product, it is necessary to ensure flat portions on the upper surface 20U and the lower surface 20D, despite the large restrictions on the shape. For this reason, if the separator body 20 is used to define the flow path portions (front-side flow path portion 51U, back-side flow path portion 51D), the degree of freedom in the arrangement and shape of the flow path portions will be reduced.

[0146] In this regard, in the first separator 2 of this embodiment, as shown in FIGS. 6 and 9, a flow path portion is formed in the gasket 5. The separator body 20 is not used to define the flow path portion. Therefore, even though the separator body 20 is a press-molded product (despite significant restrictions on the shape), the degree of freedom in the arrangement and shape of the flow path portion can be increased. Furthermore, in the first separator 2 of this embodiment, it is not necessary to impart a shape for the flow path portion to the separator body 20. Therefore, the degree of freedom in the shape of the separator body 20 can be increased. For example, the shape of the separator body 20 can be simplified. Furthermore, the separator body 20 can be imparted with a shape other than the shape for the flow path portion (such as a shape for ensuring strength).

[0147] As shown in FIGS. 16 and 17, when viewed from the top-bottom direction, the outer edge 5Ua of the top gasket 5U overlaps with the outer edge 5Da of the bottom gasket 5D. Also, when viewed from the top-bottom direction, the inner edge 5Ub of the top gasket 5U overlaps with the inner edge 5Db of the bottom gasket 5D. That is, when viewed from the top-bottom direction, the silhouette of the top gasket 5U (the outline shape when illuminated from the top-bottom direction) and the silhouette of the bottom gasket 5D overlap. In a stack 91 of cells 1, the top gaskets 5U and bottom gaskets 5D in all of the cells 1 face each other in the top-bottom direction without being misaligned in the planar direction. This improves the shape stability of the fuel cell stack 9.

[0148] 4, the front gasket 5U has a front seal portion 52U that surrounds the manifolds 20La to 20Lc, 20Ra to 20Rc, and the inter-separator flow path area A3, thereby sealing the manifolds 20La to 20Lc, 20Ra to 20Rc, and the inter-separator flow path area A3.

[0149] 7, the rear gasket 5D includes a rear seal portion 52D that surrounds the manifolds 20La to 20Lc, 20Ra to 20Rc, and the first gas flow path area A1, thereby sealing the manifolds 20La to 20Lc, 20Ra to 20Rc, and the first gas flow path area A1.

[0150] As shown in Fig. 15, the front-side flow path portion 51U and the front-side seal portion 52U are formed on the upper side of the front-side base layer 50U. That is, as shown in Fig. 6, the front-side flow path portion 51U and the front-side seal portion 52U are integrally connected via the front-side base layer 50U. This simplifies the structure of the front-side gasket 5U compared to when the front-side flow path portion 51U and the front-side seal portion 52U are independent of each other.

[0151] As shown in Fig. 15, the back-side flow path portion 51D and the back-side seal portion 52D are formed below the back-side base layer 50D. That is, as shown in Fig. 9, the back-side flow path portion 51D and the back-side seal portion 52D are integrally connected via the back-side base layer 50D. This simplifies the structure of the back-side gasket 5D compared to when the back-side flow path portion 51D and the back-side seal portion 52D are independent of each other.

[0152] 16 and 17, gasket overlapping portions O are arranged between the front-side convex portion 510U (front-side flow path portion 51U) and the back-side seal portion 52D, between the front-side seal portion 52U and the back-side convex portion 510D (back-side flow path portion 51D), between the front-side seal portion 52U and the back-side seal portion 52D, and between the front-side convex portion 510U and the back-side convex portion 510D. In the gasket overlapping portions O, the material (elastomer) of the gasket 5 is stacked in the vertical direction.

[0153] When the gasket overlap portion O is disposed between the front-side protrusions 510U and the back-side seal portion 52D, the front-side protrusions 510U and the back-side seal portion 52D can mutually reinforce each other. Specifically, the front-side protrusions 510U can be reinforced from below by the back-side seal portion 52D. This can suppress deformation of the front-side protrusions 510U. This can improve the flow straightening performance of the front-side flow path portion 51U. Furthermore, the back-side seal portion 52D can be reinforced from above by the front-side protrusions 510U. This can suppress deformation of the back-side seal portion 52D. This can improve the sealing performance of the back-side seal portion 52D. For example, as shown in FIG. 17 , the gasket overlap portion O is disposed between the plurality of front-side protrusions 510U and the first gas flow path area surrounding portion 521D. This can reinforce the plurality of front-side protrusions 510U from below by the first gas flow path area surrounding portion 521D. Additionally, the first gas flow path area surrounding portion 521D can be reinforced from above by the plurality of front-side protrusions 510U.

[0154] Similarly, when the gasket overlap portion O is disposed between the front seal portion 52U and the rear convex portion 510D, the front seal portion 52U and the rear convex portion 510D can reinforce each other, thereby improving the sealing performance of the front seal portion 52U and the flow straightening performance of the rear flow path portion 51D.

[0155] Similarly, when the gasket overlap portion O is disposed between the front seal portion 52U and the rear seal portion 52D, the front seal portion 52U and the rear seal portion 52D can reinforce each other, thereby improving the sealing performance of the front seal portion 52U and the rear seal portion 52D.

[0156] Similarly, when a gasket overlap portion O is disposed between the front-side convex portion 510U and the back-side convex portion 510D, the front-side convex portion 510U and the back-side convex portion 510D can reinforce each other. This improves the flow straightening properties of the front-side flow path portion 51U and the back-side flow path portion 51D. In addition, in the stack 9 shown in FIG. 1, the gasket overlap portions O (i.e., reinforcing portions) of all the cells 1 are stacked in the vertical direction. This improves the shape stability of the stack 9.

[0157] As shown in FIG. 15, the first gas flow path area enclosure 521D and the second gas flow path area enclosure 721U are opposed to each other in the vertical direction, sandwiching the frame 61 therebetween. This allows the first gas flow path area enclosure 521D and the second gas flow path area enclosure 721U to reinforce each other. This also allows the frame 61, i.e., the power generation member 6, to be firmly sandwiched (held) from above and below. This also improves the shape stability of the stack 9 shown in FIG. 1.

[0158] 4 and 7, the front-side groove 511U is defined by the upper surface of the front-side base layer 50U and a pair of front-side protrusions 510U adjacent to each other in the front-rear direction and protruding upward from the front-side base layer 50U. This allows the front-side groove 511U to be positioned without using the separator body 20. The same applies to the back-side groove 511D.

[0159] 4, the front-side manifold enclosures 520U at the four corners (front, rear, left, and right) surround and seal the manifolds 20La, 20Lc, 20Ra, and 20Rc above the first separator 2. As shown in Fig. 7, the first gas flow path area enclosure 521D surrounds and seals the first gas flow path area A1 below the first separator 2. For this reason, the front-side manifold enclosures 520U and the first gas flow path area enclosure 521D are independent of each other.

[0160] In this regard, as shown in FIGS. 4, 7, and 13 to 15, the first separator 2 of this embodiment has gas flow holes 20Ld arranged in the surrounding-portion overlap portion B. The gas flow holes 20Ld establish communication between the internal space 520Ua of the front-side manifold surrounding portion 520U and the internal space 521Da of the first gas flow path area surrounding portion 521D. This ensures the fluidity of air L1 between the manifold 20La and the first gas flow path area A1 while ensuring the sealing performance of the front-side manifold surrounding portion 520U and the first gas flow path area surrounding portion 521D. Similarly, the gas flow holes 20Ld ensure the fluidity of air L1 between the manifold 20Rc and the first gas flow path area A1.

[0161] Similarly, the gas flow holes 7Ld of the second separator 7 shown in Figures 10 and 11 can ensure the fluidity of hydrogen L2 between the manifold 7La and the second gas flow path area A2, and between the manifold 7Rc and the second gas flow path area A2.

[0162] As shown in FIG. 15, the inner circumferential surfaces of the multiple openings of separator body 20 (specifically, manifolds 20La-20Lc, 20Ra-20Rc, and gas flow holes 20Ld, 20Rd) are covered with an elastomer covering 5M. This protects the inner circumferential surfaces from corrosion, dust, and the like. Furthermore, multiple raw material flow holes 200 are embedded in gasket 5. This protects the inner circumferential surfaces of raw material flow holes 200 from corrosion, dust, and the like.

[0163] 6, 9, and 15, the front gasket 5U, the back gasket 5D, and the covering portion 5M are integrally connected. This simplifies the structure of the gasket 5 compared to when at least one of the front gasket 5U, the back gasket 5D, and the covering portion 5M is independent. Furthermore, the front gasket 5U and the back gasket 5D can prevent peeling from each other (from the separator body 20) via the covering portion 5M.

[0164] As shown in FIG. 10, the second separator 7 has a second separator-side flow path section 73U on its upper surface 7U. This allows the second separator 7 to provide a flow path section (second separator-side flow path section 73U) by itself. Therefore, there is no need to provide a flow path section in the power generation member 6 shown in FIG. 12. This increases the degree of freedom in the shape of the power generation member 6. For example, the shape of the power generation member 6 can be simplified. Similarly, there is no need to provide a second gas flow path area surrounding section 721U in the power generation member 6, which increases the degree of freedom in the shape of the power generation member 6.

[0165] 15, when viewed from the top and bottom, the second separator-side protrusion 730U of the second separator-side flow path section 73U of the second separator 7, the front-side gasket 5U of the first separator 2 (more specifically, the front-side manifold surrounding section 520U and the inter-separator flow path area surrounding section 521U of the front-side seal section 52U), and the back-side gasket 5D of the first separator 2 (more specifically, the back-side protrusion 510D of the back-side flow path section 51D) overlap. This allows the second separator-side protrusion 730U, the front-side gasket 5U, and the back-side gasket 5D to reinforce each other.

[0166] 3, 7, and 15, the first gas flow path area A1 is sealed in a double ring shape by an inner first gas flow path area enclosure 521D and an outer general gas flow path area enclosure 522D, thereby improving the sealing performance of the first gas flow path area A1.

[0167] 10 and 15, similar to the first gas flow path area A1, the second gas flow path area A2 is sealed in a double ring shape by an inner second gas flow path area enclosure 721U and an outer comprehensive gas flow path area enclosure 522D. This improves the sealing performance of the second gas flow path area A2. Furthermore, the single comprehensive gas flow path area enclosure 522D can comprehensively improve the sealing performance of the first gas flow path area A1 and the second gas flow path area A2.

[0168] (Functions and Effects of the Manufacturing Method of the First Separator 2 and the Stack 9) Next, the effects of the manufacturing method of the first separator 2 and the stack 9 will be described. As described above, the manufacturing method of the first separator 2 of this embodiment includes a press molding step and an injection molding step. The injection molding step includes a manifold selection step, an arrangement step, a raw material injection step, and a curing step.

[0169] 19 and 20, in the injection molding process, the covering portion 5M, the front gasket 5U, and the back gasket 5D are manufactured from a common raw material (elastomer) E. Therefore, compared to when these components are made from different raw materials E, the manufacturing cost can be reduced because only a single type of raw material E is required. In addition, the number of manufacturing steps can be reduced.

[0170] 19 and 20, in the injection molding process, the covering portion 5M, the front gasket 5U, and the rear gasket 5D are molded integrally. Therefore, compared to when the covering portion 5M, the front gasket 5U, and the rear gasket 5D are molded separately, only one mold 8 is required, which reduces the manufacturing cost and the number of manufacturing steps.

[0171] As shown in FIGS. 19 and 20, in the raw material injection step, raw material E is injected into gasket cavities 5c using openings (specifically, manifolds 20La-20Lc, 20Ra-20Rc, gas flow holes 20Ld, 20Rd, and multiple raw material flow holes 200). This reduces the variation in the flow distance and filling time of raw material E between front gasket cavities 5Uc and back gasket cavities 5Dc. This reduces the variation in molding precision between front gasket 5U and back gasket 5D.

[0172] 16 and 17, the silhouettes of the front gasket 5U and the back gasket 5D overlap when viewed from the top and bottom. Therefore, when the gasket 5 is integrally molded with the separator body 20 in the raw material injection step, cavities of the same shape (front gasket cavity 5Uc and back gasket cavity 5Dc) can be secured on both the top and bottom sides of the separator body 20, as shown in FIG. 19. Therefore, even if the separator body 20 has a thin vertical thickness (i.e., the separator body 20 has low rigidity), deformation of the separator body 20 due to factors such as raw material injection pressure can be suppressed.

[0173] 20, in the raw material injection step, raw material E is divided into a front gasket cavity 5Uc and a back gasket cavity 5Dc, starting from the covering portion cavity 5Mc. This reduces the variation in the flow distance and filling time of raw material E between the front gasket cavity 5Uc and the back gasket cavity 5Dc. This reduces the variation in molding accuracy between the front gasket 5U and the back gasket 5D.

[0174] 19 and 20, in the mold clamped state, the front contact portion 800U and the back contact portion 800D overlap when viewed from the top-bottom direction. That is, the separator body 20 is supported from both sides in the top-bottom direction by the front contact portion 800U and the back contact portion 800D. This makes it possible to suppress deformation of the separator body 20 during the raw material injection step.

[0175] As shown in Figures 19 and 20, when the mold is clamped, the cavity 50Uc for the top substrate layer and the cavity 50Dc for the bottom substrate layer overlap when viewed from the top to bottom. That is, the cavity 50Uc for the top substrate layer and the cavity 50Dc for the bottom substrate layer face each other in the top to bottom direction, sandwiching the separator body 20 therebetween. This prevents deformation of the separator body 20 during the raw material injection process. This also increases the molding precision of the top gasket 5U and the bottom gasket 5D.

[0176] 15, the vertical thickness T of the separator body 20 is set to 100%, and the vertical thickness TU of the front base layer 50U is set to be within the range of 100% to 300%. Therefore, the forming accuracy of the front base layer 50U can be improved compared to when the vertical thickness TU is less than 100% or more than 300%.

[0177] 15, the vertical thickness TD of the back base layer 50D is set to be within the range of 100% to 300% of the vertical thickness T of the separator body 20. This allows for higher forming accuracy of the back base layer 50D compared to when the vertical thickness TD is less than 100% or more than 300%.

[0178] The method for producing the first separator 2 of this embodiment includes a manifold selection step before the arrangement step. Therefore, the arrangement and number of manifolds 20La-20Lc and 20Ra-20Rc used to inject the raw material E can be adjusted depending on the fluidity of the raw material E. For example, if the fluidity of the raw material E is high (e.g., if the raw material E is silicone rubber), the number of manifolds 20La-20Lc and 20Ra-20Rc used to inject the raw material E can be reduced. On the other hand, if the fluidity of the raw material E is low (e.g., if the raw material E is EPDM), the number of manifolds 20La-20Lc and 20Ra-20Rc used to inject the raw material E can be increased.

[0179] As shown in FIG. 15 , when viewed from the top and bottom, the second separator-side protrusion 730U of the second separator-side flow path section 73U of the second separator 7, the front-side gasket 5U of the first separator 2 (more specifically, the front-side manifold surrounding portion 520U and the inter-separator flow path area surrounding portion 521U of the front-side seal portion 52U), and the back-side gasket 5D of the first separator 2 (more specifically, the back-side protrusion 510D of the back-side flow path section 51D) overlap. This simplifies the stacking process of the first separator 2, the power generation member 6, and the second separator 7. Furthermore, the shape stability of the stack 9 can be improved after the fastening process.

[0180] Focusing on the manufacturing process of each of the first separator 2 and the second separator 7, bonding is only required once during the manufacturing process of the first separator 2, when the gasket 5 (covering portion 5M, front gasket 5U, and back gasket 5D) is molded onto the separator body 20. Therefore, compared to when multiple gaskets are molded separately onto the separator body 20, or when gaskets are molded onto not only the first separator 2 but also the second separator 7, the bonding process and the cleaning process prior to the bonding process can be reduced. This allows for improved productivity and practicality of the stack 9.

[0181] As shown in Figures 1, 3, and 15, the first separator 2, the power generation member 6, and the second separator 7 are pressed against each other but are not bonded to each other. That is, in the lamination process, the first separator 2, the power generation member 6, and the second separator 7 are laminated in a non-bonded state. This eliminates the need for a bonding process to bond these components and a cleaning process prior to the bonding process. This improves the productivity and practicality of the stack 9.

[0182] Second Embodiment The cell of this embodiment differs from the cell of the first embodiment in that a second separator-side flow path section is not provided in the second separator, and a frame-side flow path section and a second gas flow path area surrounding section are provided in the frame section of the power generation component. Only these differences will be described here.

[0183] FIG. 22 shows a top view of the second separator of the cell of this embodiment. Note that parts corresponding to those in FIG. 10 are denoted by the same reference numerals. The second separator 7 is a press-formed metal plate. As shown in FIG. 22, the second separator-side flow path section 73U shown in FIG. 10 is not disposed on the upper surface 7U of the second separator 7. Note that the lower surface shape of the second separator 7 is symmetrical to the upper surface shape shown in FIG. 22.

[0184] Figure 23 shows a bottom view of the power generation member of the cell of this embodiment. Note that parts corresponding to those in Figure 12 are denoted by the same reference numerals. As shown in Figure 23, two frame-side flow path sections 63D and a second gas flow path area surrounding section 621D are formed on the bottom surface of the frame section 61.

[0185] The frame-side flow path 63D includes a plurality of frame-side protrusions 630D and a plurality of frame-side grooves 631D. The frame-side protrusions 630D protrude downward from the lower surface of the frame 61. The frame-side protrusions 630D are arranged side by side at predetermined intervals in the front-rear direction. The frame-side protrusions 630D are rib-shaped and extend in the left-right direction.

[0186] The frame portion groove 631D is defined between a pair of frame portion protrusions 630D adjacent in the front-rear direction. The frame portion groove 631D extends in the left-right direction. Hydrogen L2 flows in the frame portion groove 631D.

[0187] The second gas flow path area enclosing portion 621D encloses the second gas flow path area A2 and the two frame portion-side flow path portions 63D in an endless annular shape when viewed from above and below. The second gas flow path area enclosing portion 621D is in pressure contact with the upper surface of the second separator (not shown).

[0188] The frame portion 61 does not have a frame portion-side flow path portion or a second gas flow path area surrounding portion disposed on its upper surface. That is, the upper surface shape is the same as that shown in FIG. 12. Thus, the upper surface and the lower surface have different shapes. Furthermore, the upper surface and the lower surface are not symmetrical to each other.

[0189] The cell of this embodiment and the cell of the first embodiment have similar effects with respect to the common configuration. According to the cell of this embodiment, as shown in FIG. 23, the frame portion 61 alone can provide a flow path portion (frame portion-side flow path portion 63D). Furthermore, the frame portion 61 alone can provide a second gas flow path area surrounding portion 621D. Therefore, as shown in FIG. 22, it is not necessary to provide a flow path portion or a second gas flow path area surrounding portion in the second separator 7. This increases the degree of freedom in the shape of the second separator 7. For example, the shape of the second separator 7 can be simplified. As an example, a press-molded product can be used as the second separator 7.

[0190] The frame-side flow path section 63D shown in Fig. 23 is disposed in the same position as the second-separator-side flow path section 73U shown in Fig. 15. Therefore, when viewed from the top-bottom direction, the frame-side protrusion 630D (second-separator-side protrusion 730U shown in Fig. 15) of the frame-side flow path section 63D, the front-side gasket 5U of the first separator 2 (more specifically, the front-side manifold enclosure 520U and inter-separator flow path area enclosure 521U of the front-side seal section 52U), and the back-side gasket 5D of the first separator 2 (more specifically, the back-side protrusion 510D of the back-side flow path section 51D) overlap with each other. Therefore, the frame-side protrusion 630D, the front-side gasket 5U, and the back-side gasket 5D can mutually reinforce each other.

[0191] The second gas flow path area enclosure 621D is located at the same position as the second gas flow path area enclosure 721U shown in FIG. 10 when viewed from the top-bottom direction. The first gas flow path area enclosure 521D shown in FIG. 15 and the second gas flow path area enclosure 621D shown in FIG. 23 face each other in the top-bottom direction, with the frame 61 sandwiched between them. This allows the first gas flow path area enclosure 521D and the second gas flow path area enclosure 621D to reinforce each other. This also allows the frame 61, i.e., the power generation member 6, to be firmly sandwiched (held) from above and below. This also improves the shape stability of the stack 9 shown in FIG. 1.

[0192] The method for manufacturing the stack of this embodiment is the same as the method for manufacturing the stack of the first embodiment. As described above, the frame-side convex portion 630D, the front gasket 5U, and the back gasket 5D overlap when viewed from the top and bottom. This simplifies the stacking process of the first separator 2, the power generation member 6, and the second separator 7. Furthermore, the shape stability of the stack 9 can be improved after the fastening process.

[0193] <Other> The above describes embodiments of the double-sided gasketed separator and stack manufacturing method of the present disclosure. However, the embodiments are not particularly limited to the above-described embodiments. Various modifications and improvements that can be made by those skilled in the art are also possible.

[0194] The configuration of a double-sided gasketed separator manufactured by the double-sided gasketed separator and stack manufacturing method of the present disclosure is not particularly limited to the configuration of the first separator 2 in the above embodiment. It is sufficient that the covering portion 5M, the front gasket 5U, and the rear gasket 5D are integrally connected. The presence or absence of the gasket 5 in the second separator 7 is not particularly limited. At least a portion of the gasket 5 may be disposed on the second separator 7. For example, the rear manifold surrounding portion 520D, the first gas flow path area surrounding portion 521D, and the overall gas flow path area surrounding portion 522D of the rear seal portion 52D of the rear gasket 5D shown in FIG. 3 may be disposed (transferred) on the upper surface 7U of the second separator 7.

[0195] The second separator-side flow path section 73U shown in Fig. 10 and the frame-side flow path section 63D shown in Fig. 23 may be arranged alternatively. Alternatively, both may be arranged together. That is, it is sufficient that at least one of the second separator-side flow path section 73U and the frame-side flow path section 63D is arranged.

[0196] The type of fastening member for fastening the stack 9 is not particularly limited. The fastening member may be a tie rod 92, a bolt, a clamp, or the like. Alternatively, a case for accommodating the stack 9 may be used. The shape, position, size, and number (hereinafter abbreviated as "shape, etc.") of the flow path sections (front-side flow path section 51U, back-side flow path section 51D, second separator-side flow path section 73U, and frame-side flow path section 63D) are not particularly limited. The same applies to the shapes, etc. of the front-side seal section 52U, back-side seal section 52D, second gas flow path area surrounding section 621D, 721U, manifolds 20La to 20Lc, 20Ra to 20Rc, 7La to 7Lc, 7Ra to 7Rc, gas flow holes 20Ld, 20Rd, 7Ld, 7Rd, and raw material flow hole 200.

[0197] The number of openings for injecting raw material E (manifolds 20La-20Lc, 20Ra-20Rc, gas flow holes 20Ld, 20Rd, and multiple raw material flow holes 200) selected in the manifold selection step is not particularly limited. For example, only a single manifold 20La-20Lc or 20Ra-20Rc may be used to inject raw material E. Alternatively, multiple manifolds 20La-20Lc or 20Ra-20Rc may be used to inject raw material E. Furthermore, raw material flow hole 200 may or may not be used to inject raw material E. Raw material flow hole 200 may be used only to flow raw material E between front gasket cavity 5Uc and back gasket cavity 5Dc.

[0198] The flow paths of the air L1, hydrogen L2, and coolant L3 shown in Figures 1 to 3 are not particularly limited. The flow direction of the air L1 relative to the first gas flow path area A1 may be opposite to the direction shown in the figures. The same applies to the flow direction of the hydrogen L2 relative to the second gas flow path area A2 and the flow direction of the coolant L3 relative to the inter-separator flow path area A3. The air L1 may flow through the second gas flow path area A2, and the hydrogen L2 may flow through the first gas flow path area A1.

[0199] The type of oxidant gas is not particularly limited, as long as it contains oxygen, such as air L1. The type of fuel gas is not particularly limited, as long as it contains hydrogen, such as hydrogen L2 or hydrocarbons. The type of coolant L3 is not particularly limited, as long as it can cool the cell 1.

[0200] The arrangement direction of the stack 9 shown in Fig. 1 is not particularly limited. The stacking direction may be vertical, horizontal, or a direction intersecting the vertical and horizontal directions. The shapes of the first separator 2 and the second separator 7 are not particularly limited. They may be rectangular, square, or the like in a plan view.

[0201] The material of the first separator 2 and the second separator 7 is not particularly limited. Preferably, they are made of a conductive, non-corrosive resin, metal (e.g., a press-molded product), etc. Examples include stainless steel, titanium, copper, magnesium, aluminum, carbon, graphite, ceramics, and conductive resin (thermoplastic resin or thermosetting resin containing carbon, graphite, polyacrylonitrile-based carbon fiber, etc.).

[0202] The material of the gasket 5 is not particularly limited. It may be an elastomer having insulating properties and rubber elasticity. It is sufficient that the material has fluidity at the stage of raw material E. In addition to the rubber component, the gasket 5 may contain a crosslinking agent, a co-crosslinking agent, a processing aid, a softener, a reinforcing material, etc. Suitable rubber components include VMQ (silicone rubber), as well as silicone rubbers other than VMQ (such as PVMQ (phenyl vinyl methyl silicone rubber) and FVMQ (fluoro vinyl methyl silicone rubber)), EPDM (ethylene propylene diene rubber), and FKM (fluoro rubber). When liquid silicone rubber is used as raw material E, the type of liquid silicone rubber is not particularly limited. It may be a one-component type or a two-component type. It may also be a room temperature curing type or a heat curing type. [Explanation of symbols]

[0203] 1: Cell 2: First separator (separator with double-sided gasket) 20: separator body, 20La to 20Lc: manifold, 20Ld: gas flow hole, 20Ra to 20Rc: manifold, 20Rd: gas flow hole, 200: raw material flow hole, 201: first uneven portion, 202: rod insertion hole, 20U: upper surface (surface), 20D: lower surface (rear surface) 5: Gasket, 5c: Gasket cavity (cavity), 5U: Front gasket, 5Ua: Outer edge, 5Ub: Inner edge, 5Uc: Cavity for front gasket, 50U: Front base layer, 50Uc: Cavity for front base layer, 51U: Front flow path portion, 510U: Front convex portion, 511U: Front groove portion, 52U: Front seal portion, 52Uc: Cavity for front seal portion, 520U: Front manifold surrounding portion, 520Ua: Internal space, 520Uc: Cavity for front manifold surrounding portion, 521U: Inter-separator flow path area surrounding portion, 521Uc: Cavity for inter-separator flow path area surrounding portion, 53U: Front abutment hole, 5D: Back gasket, 5D a: outer edge, 5Db: inner edge, 5Dc: cavity for backside gasket, 50D: backside base layer, 50Dc: cavity for backside base layer, 51D: backside flow path portion, 510D: backside convex portion, 511D: backside groove portion, 52D: backside seal portion, 52Dc: cavity for backside seal portion, 520D: backside manifold surrounding portion, 520Dc: cavity for backside manifold surrounding portion, 521D: first gas flow path area surrounding portion, 521Da: internal space, 521Dc: cavity for first gas flow path area surrounding portion, 522D: overall gas flow path area surrounding portion, 522Dc: cavity for overall gas flow path area surrounding portion, 53D: backside abutment hole, 5M: covering portion, 5Mc: cavity for covering portion 6: power generation member, 60: power generation section, 61: frame section, 621D: second gas flow path area surrounding section, 63D: frame section side flow path section, 630D: frame section side convex section, 631D: frame section side groove section 7: second separator, 7La to 7Lc: manifold, 7Ld: gas flow hole, 7Ra to 7Rc: manifold, 7Rd: gas flow hole, 71: second concave-convex portion, 72: rod insertion hole, 7U: upper surface (surface), 721U: second gas flow path area surrounding portion, 73U: second separator side flow path portion, 730U: second separator side convex portion, 731U: second separator side groove portion, 7D: lower surface (rear surface) 8: Mold, 8U: Upper mold, 80U: Mold surface, 800U: Front contact part, 8D: Lower mold, 80D: Mold surface, 800D: Back contact part 9: stack, 90: end plate, 91: laminate, 92: tie rod A1: First gas flow area, A2: Second gas flow area, A3: Flow area between separators, B: Overlap between enclosed parts, E: Raw material, F: Fastening force, G: Gate, L1: Air (fluid, gas), L2: Hydrogen (fluid, gas), L3: Coolant (fluid), O: Gasket overlap, S: Gate cut part, Sc: Cavity for gate cut part, T: Plate thickness in the vertical direction (plate thickness in the front and back directions), TD: Plate thickness in the vertical direction (plate thickness in the front and back directions), TU: Plate thickness in the vertical direction (plate thickness in the front and back directions)

Claims

1. a separator body that is a press-formed metal plate and has a manifold that penetrates the separator body in the front-to-back direction and through which a predetermined fluid flows; an elastomer covering portion disposed on an inner peripheral surface of the manifold; a front gasket made of an elastomer and disposed on the surface of the separator body; a back gasket made of elastomer and disposed on the back surface of the separator body; Equipped with the front gasket is made of the elastomer and has a front flow path portion through which a predetermined fluid flows, The rear gasket is made of the elastomer and has a rear flow path through which a predetermined fluid flows. A method for manufacturing a separator with a double-sided gasket, comprising the steps of: an arrangement step of arranging the separator body in the mold in an open state so that a gate of the mold faces the manifold, and then clamping the mold; a raw material injection step of injecting raw material from the manifold into the cavity of the mold; a curing step of hardening the raw material injected into the cavity to integrally mold the covering portion, the front gasket, and the rear gasket and bond them to the separator body; A method for manufacturing a separator with a double-sided gasket.

2. The cavity is a cavity for molding the covering portion; a front gasket cavity connected to the covering portion cavity and configured to mold the front gasket; a back gasket cavity connected to the covering portion cavity and configured to mold the back gasket; and the front-side gasket cavities include a front-side base layer cavity having the narrowest width in the front-back direction among the front-side gasket cavities, the back-side gasket cavities include a back-side base layer cavity having the narrowest width in the front-back direction among the back-side gasket cavities, 2. The method for manufacturing a separator with double-sided gasket according to claim 1, wherein the cavity for the front base layer and the cavity for the back base layer overlap each other when viewed from the front and back directions.

3. the separator body has a plurality of the manifolds, 2. The method for manufacturing a separator with a double-sided gasket according to claim 1, further comprising, before the placing step, a manifold selection step of selecting the manifold to be used for injecting the raw material from among a plurality of manifolds in accordance with the fluidity of the raw material.

4. 1. A method for manufacturing a fuel cell stack comprising a stack of multiple cells, comprising: The cell is a first separator manufactured by the method for manufacturing a separator with a double-sided gasket according to claim 1; a power generation member laminated on the rear side of the separator body of the first separator, the power generation member including a power generation section having a membrane electrode assembly and a frame section surrounding the power generation section; a second separator that is laminated on the back side of the power generation member and does not have the front gasket or the back gasket; and the frame portion has, on a rear surface thereof, a frame portion-side flow path portion through which the fluid, i.e., gas, flows; the frame portion-side flow path portion has a frame portion-side convex portion, When viewed from the front and back direction, the frame portion-side convex portion overlaps with the front gasket and the rear gasket of the first separator, a preparation step of preparing the first separator, the power generation member, and the second separator; a lamination step of laminating the first separator, the power generation member, and the second separator in this order to produce the laminate; a fastening step of applying a fastening force to the laminate from both sides in the stacking direction to fabricate the stack; 10. A method for manufacturing a fuel cell stack, comprising:

5. 1. A method for manufacturing a fuel cell stack comprising a stack of multiple cells, comprising: The cell is a first separator manufactured by the method for manufacturing a separator with a double-sided gasket according to claim 1; a power generation member laminated on the rear side of the separator body of the first separator, the power generation member including a power generation section having a membrane electrode assembly and a frame section surrounding the power generation section; a second separator that is laminated on the back side of the power generation member and does not have the front gasket or the back gasket; and the second separator has, on a surface thereof, a second separator-side flow path portion through which the fluid, i.e., gas, flows; the second separator-side flow path portion has a second separator-side convex portion, When viewed from the front and back direction, the second separator-side convex portion overlaps with the front gasket and the back gasket of the first separator, a preparation step of preparing the first separator, the power generation member, and the second separator; a lamination step of laminating the first separator, the power generation member, and the second separator in this order to produce the laminate; a fastening step of applying a fastening force to the laminate from both sides in the stacking direction to fabricate the stack; 10. A method for manufacturing a fuel cell stack, comprising:

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