Composite component for fuel cell and method for manufacturing the same

Abstract

To provide a fuel cell composite member capable of suppressing the deterioration of sealing properties and a manufacturing method therefor.SOLUTION: A fuel cell composite member 1 includes a plate-like member 2 having a gasket disposition part 4 and a gasket 5 integrally molded with the gasket disposition part 4. The gasket disposition part 4 has a front-side disposition part 4U disposed on a front surface 2U and a rear-side disposition part 4D disposed on a rear surface 2D. The front-side disposition part 4U has a continuous part 40U disposed around desired sealing target regions 22ULa, 22ULc, 22URa, 22URc, and 22UM, and an independent part 41U independent from the continuous part 40U and disposed on the outer side of the continuous part 40U in a surface direction. The continuous part 40U and the independent part 41U communicate with each other through continuous part inner penetrating holes 402Ua, the rear-side disposition part 4D, and independent part inner penetrating holes 410U. Inside the independent part 41U, the gasket 5 is disposed not to protrude forward from the front surface 2U.SELECTED DRAWING: Figure 8

Description

Technical Field

[0005] , , ,

[0001] The present disclosure relates to a composite member for a fuel cell in which a gasket is integrally formed on a plate-like member and a method for manufacturing the same.

Background Art

[0002] A gasket is disposed around a sealing target area (such as a manifold, a membrane electrode assembly, etc.) of a separator of a fuel cell. As a method of disposing a gasket on a separator, there is a method of adhering a separately manufactured gasket to the separator. In the case of this method, it is necessary to perform an operation of attaching a thin and flexible gasket to the gasket disposal portion of the separator. Further, before attaching the gasket, it is necessary to perform an operation of applying an adhesive to the gasket disposal portion of the separator. These operations are complicated.

[0003] In this regard, Patent Document 1 discloses a method of integrally forming a gasket on a separator. In the case of this method, by injecting a gasket raw material into a cavity of a mold in which a separator is disposed, the separator and the gasket can be integrated while injection-molding the gasket. Therefore, the above-described gasket disposal operation and adhesive application operation are unnecessary.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the case of the method of the same document, due to a molding defect of the gasket, the shape accuracy of the gasket may be reduced. Therefore, there is a possibility that the sealing performance with respect to the sealing target area may be reduced. Therefore, an object of the present disclosure is to provide a composite member for a fuel cell capable of suppressing a reduction in sealing performance and a method for manufacturing the same. [Means for solving the problem]

[0006] (1) To solve the above problems, the fuel cell composite member of the present disclosure comprises a plate-shaped member having a gasket arrangement portion and a gasket integrally molded with the gasket arrangement portion, wherein the gasket arrangement portion has a front-side arrangement portion arranged on the surface of the plate-shaped member and a back-side arrangement portion arranged on the back surface of the plate-shaped member, and the front-side arrangement portion has a continuous portion recessed in the surface and arranged around a desired sealing target area and a recessed in the surface and independent of the continuous portion, The continuous portion has an independent portion located on the outer side in the surface direction, the continuous portion has a through-hole that penetrates the plate-shaped member in the front-back direction and connects to the back-side portion, the independent portion has a through-hole that penetrates the plate-shaped member in the front-back direction and connects to the back-side portion, the continuous portion and the independent portion are in communication via the through-hole in the continuous portion, the back-side portion and the through-hole in the independent portion, and the gasket is arranged inside the independent portion so as not to protrude from the surface to the front side.

[0007] The gasket is integrally molded into the gasket placement area of ​​the plate-shaped member. Therefore, compared to a method of bonding a pre-fabricated, separate gasket to the plate-shaped member, the number of work steps can be reduced. Furthermore, the gasket and the plate-shaped member can be positioned and integrated simultaneously with the gasket molding process.

[0008] The plate-shaped member has through-holes in the continuous section and through-holes in the independent section. This increases the contact area between the plate-shaped member and the gasket. Therefore, even without adhesive, displacement or detachment of the gasket from the plate-shaped member can be suppressed. Furthermore, the gasket is integrally molded on both the front and back surfaces of the plate-shaped member via the through-holes in the continuous section and through-holes in the independent section. Therefore, due to the anchoring effect, displacement or detachment of the gasket from the plate-shaped member can be suppressed even without adhesive.

[0009] The independent section is separate from the continuous section (i.e., the area to be sealed). Furthermore, the independent section is positioned on the outer side in the plane direction of the continuous section. For this reason, even if a molding defect occurs in the gasket of the independent section (more specifically, the portion of the gasket that is located in the independent section; similarly, "gasket of any part" refers to "the portion of the gasket that is located in that arbitrary part"), in other words, even if the shape accuracy of the gasket of the independent section is low, the impact of that shape accuracy on the gasket of the continuous section is less likely to occur. Therefore, a decrease in sealing performance caused by the gasket of the independent section can be suppressed.

[0010] In the isolated section, the gasket is positioned so that it does not protrude from the surface of the plate-shaped member to the front side. Therefore, even if the shape accuracy of the gasket in the isolated section is low, the reduction in sealing performance caused by the gasket in the isolated section can be suppressed.

[0011] (2) Preferably, in the above configuration, the continuous portion has a front groove portion on which the seal lip of the gasket protrudes from the surface to the front side, and a plurality of side protrusions protruding outward in the groove width direction from the front groove portion, and the plurality of side protrusions have a plurality of through side protrusions having through holes in the continuous portion, and a plurality of non-through side protrusions having non-through holes in the continuous portion that do not penetrate the plate-shaped member in the front-back direction.

[0012] The plate-shaped member has a groove on the front side, a projection on the through side, a through hole in the continuous section, a projection on the non-through side, and a non-through hole in the continuous section. This increases the contact area between the plate-shaped member and the gasket. Therefore, even though it is not adhesive, it can suppress displacement and detachment of the gasket from the plate-shaped member.

[0013] On the front side of the groove portion, the gasket's seal lip (more specifically, the top of the seal lip that forms the seal line) is positioned. On the other hand, the through-holes within the continuous portion are positioned on the through-side projection, and the non-through-holes within the continuous portion are positioned on the non-through-side projection. In other words, the through-holes and non-through-holes within the continuous portion are positioned to avoid the groove portion on the front side. Therefore, even if the shape accuracy of the gaskets in the through-holes and non-through-holes within the continuous portion is low, the effect of this shape accuracy is less likely to affect the gasket in the groove portion on the front side. Consequently, a decrease in sealing performance caused by the gaskets in the through-holes and non-through-holes within the continuous portion can be suppressed.

[0014] (3) Preferably, in any of the above configurations, the surface has a rectangular shape in plan view, and the longitudinal direction of the surface is the X direction and the short direction is the Y direction, the surface groove portion has a plurality of X-direction extending portions extending in the X direction and a plurality of Y-direction extending portions extending in the Y direction, the independent portion includes the X-direction central portion of the surface and is arranged in pairs on both the Y-direction outer sides of the plurality of X-direction extending portions, and of the plurality of through-side projections, two of the through-side projections include the Y-direction central portion of the surface and are X-direction outer end projections arranged on both the X-direction outer sides of the plurality of Y-direction extending portions.

[0015] The two independent sections are positioned to include the center of the surface in the X direction. Furthermore, the two independent sections are positioned on both the Y-sides of the multiple X-extending sections. In addition, the independent sections have through holes. As a result, displacement and detachment of the gasket from the plate-like member can be suppressed at the position including the center of the surface in the X direction and on both the Y-sides of the surface groove section.

[0016] The two X-direction outer end projections are positioned to include the Y-direction center of the surface. Furthermore, the two X-direction outer end projections are positioned on both the X-direction outer sides of the multiple Y-direction extending portions. In addition, through holes are provided within the continuous portion of the X-direction outer end projections. As a result, displacement and detachment of the gasket from the plate-shaped member can be suppressed at the position including the Y-direction center of the surface and on both the X-direction outer sides of the surface groove portion.

[0017] (4) Preferably, in any of the above configurations, two of the multiple through-side projections are Y-direction outer end projections that include the X-direction central portion of the surface and are located on both Y-direction outer sides of the multiple X-direction extending portions.

[0018] The two Y-direction outer end projections are positioned to include the X-direction center of the surface. Furthermore, the two Y-direction outer end projections are positioned on both Y-sides of the multiple X-direction extending portions. In addition, through holes are provided within the continuous portion of the Y-direction outer end projections. As a result, displacement and detachment of the gasket from the plate-like member can be suppressed at positions including the X-direction center of the surface and on both Y-sides of the surface groove portion.

[0019] (5) Preferably, in any of the above configurations, the continuous portion has a branching and merging section connecting the X-direction outer end projection and the Y-direction outer end projection, and in the branching and merging section, with the direction toward the X-direction outer end projection being the upstream side and the direction toward the Y-direction outer end projection being the downstream side, the branching and merging section has an upstream main body, a downstream main body located downstream of the upstream main body, a plurality of branch portions located between the upstream main body and the downstream main body, a branching section connecting the downstream end of the upstream main body and the upstream ends of the plurality of branch portions, and a merging section connecting the downstream ends of the plurality of branch portions and the upstream end of the downstream main body, wherein at least one of the plurality of through-side projections is a merging section projection located in the merging section, and at least one of the plurality of non-through-side projections is a branch portion projection located in any of the branch portions.

[0020] In this configuration, a confluence side projection is positioned at the confluence. This increases the contact area between the confluence and the gasket. Furthermore, the gasket is integrally molded on both the front and back surfaces of the plate-shaped member through through-holes in the continuous portion of the confluence side projection. This provides an anchoring effect that suppresses displacement and detachment of the gasket from the confluence. Additionally, in this configuration, a branch side projection is positioned at the branch. This increases the contact area between the branch and the gasket.

[0021] (6) Preferably, in any of the above configurations, the through-side projection has a tapered shape with a through-hole in the continuous portion at its outer end in the groove width direction, and the non-through-side projection has a tapered shape with a non-through-hole in the continuous portion at its outer end in the groove width direction.

[0022] In this configuration, the through-hole in the continuous section is located at the outer end in the groove width direction of the through-side projection. That is, the through-hole in the continuous section is located at the position furthest from the surface groove on the through-side projection. Therefore, even if the shape accuracy of the gasket in the through-hole in the continuous section is low, the effect of this shape accuracy is less likely to affect the gasket in the surface groove. Consequently, a decrease in sealing performance caused by the gasket in the through-hole in the continuous section can be suppressed.

[0023] In this configuration, a non-through hole within the continuous section is positioned at the outer end in the groove width direction of the non-through side projection. That is, the non-through hole within the continuous section is positioned at the position furthest from the front groove in the non-through side projection. Therefore, even if the shape accuracy of the gasket in the non-through hole within the continuous section is low, the effect of this shape accuracy is less likely to affect the gasket in the front groove. Consequently, a decrease in sealing performance caused by the gasket in the non-through hole within the continuous section can be suppressed.

[0024] (7) Preferably, in any of the above configurations, the continuous portion further has a front intervening portion interposed between a plurality of front groove portions adjacent to each other in the planar direction, and the front intervening portion has a through hole within the continuous portion and a non-through hole within the continuous portion.

[0025] The front-side intervening portion has a through-hole within the continuous portion and a non-through-hole within the continuous portion. Therefore, the contact area between the front-side intervening portion and the gasket can be increased. Accordingly, even though there is no adhesion, displacement and detachment of the gasket from the front-side intervening portion can be suppressed. Further, the gasket is integrally formed on both the front and back surfaces of the plate-shaped member through the through-hole within the continuous portion. Therefore, due to the anchor effect, even though there is no adhesion, displacement and detachment of the gasket from the front-side intervening portion can be suppressed.

[0026] (8) Preferably, in any of the above configurations, the back-side placement portion is recessed in the back surface, and includes a back-side groove portion where the seal lip of the gasket protrudes from the back surface to the back side, a groove edge portion that is flush with the back surface and extends outward in the plane direction from the back-side groove portion, and a back-side intervening portion that is recessed in the back surface, intervenes between a plurality of adjacent back-side groove portions in the plane direction, and where the through-hole within the continuous portion of the front-side intervening portion opens.

[0027] The back-side placement portion has a groove edge portion that is flush with the back surface of the plate-shaped member. Therefore, a surface seal portion can be arranged on the back surface by the gasket of the groove edge portion. Further, the through-hole within the continuous portion of the front-side placement portion opens in the back-side placement portion. Therefore, the contact area between the plate-shaped member and the gasket can be increased. Also, due to the anchor effect, displacement and detachment of the gasket from the back-side placement portion can be suppressed even though there is no adhesion. In particular, the through-hole within the continuous portion of the front-side intervening portion opens in the back-side intervening portion. Therefore, the contact area between the plate-shaped member and the gasket can be increased between the front-side intervening portion and the back-side intervening portion. Also, due to the anchor effect, displacement and detachment of the gasket from the back-side intervening portion can be suppressed even though there is no adhesion.

[0028] (9) Preferably, in any of the above configurations, the membrane electrode assembly further comprises an electrolyte membrane and a pair of catalyst layers disposed on both the front and back surfaces of the electrolyte membrane, wherein the gasket is integrally molded with the plate-shaped member and the membrane electrode assembly.

[0029] The gasket is integrally molded with the plate-shaped member and the membrane electrode assembly. Therefore, compared to a method in which a separate, pre-fabricated gasket is bonded to the plate-shaped member and the membrane electrode assembly is laminated onto the plate-shaped member, the number of work steps can be reduced. In addition, the gasket, plate-shaped member, and membrane electrode assembly can be positioned and integrated simultaneously with the molding of the gasket.

[0030] (10) Preferably, in a method for manufacturing a composite member for a fuel cell having any of the above configurations, the configuration includes: an arrangement step of arranging the plate-shaped member in the cavity of the mold such that the gate of the mold faces the continuous portion; and a raw material injection step of injecting the gasket raw material into the cavity from the gate, causing the raw material to flow into the continuous portion, causing the raw material to flow from the continuous portion to the back side arrangement portion through through holes in the continuous portion, and causing the raw material to flow from the back side arrangement portion to the independent portion through through holes in the independent portion.

[0031] The composite components for fuel cells manufactured using this configuration have the same effects as the configuration described in (1) above. With this configuration, in the raw material injection process, the gasket raw material circulates through the rear side placement area before finally reaching the independent area. Therefore, it is possible to suppress the occurrence of molding defects in the rear side placement area due to flow.

[0032] (11) Preferably, in the configuration of (10) above, the continuous portion has a front groove portion on which the seal lip of the gasket protrudes from the surface to the front side, and a plurality of side protrusions protruding outward in the groove width direction from the front groove portion, wherein the plurality of side protrusions have a plurality of through side protrusions having through holes in the continuous portion, and a plurality of non-through side protrusions having non-through holes in the continuous portion that do not penetrate the plate-shaped member in the front-back direction.

[0033] The composite component for fuel cells manufactured by this configuration has the same effects as the configuration described in (2) above. According to this configuration, in the raw material injection process, the raw material for the gasket flows into the through-hole in the continuous section via the through-side projection. By passing the raw material through the through-side projection, it is possible to suppress the entrapment of air when the raw material flows into the through-hole in the continuous section. Therefore, it is possible to suppress the occurrence of molding defects in the rear-side placement area.

[0034] (12) Preferably, in any of the configurations described in (10) and later (including (10); the same applies hereinafter), the surface has a rectangular shape in plan view, and of the surface directions, the longitudinal direction is the X direction and the short direction is the Y direction, the surface groove portion has a plurality of X-direction extending portions extending in the X direction and a plurality of Y-direction extending portions extending in the Y direction, the independent portion includes the X-direction central portion of the surface and is arranged in pairs on both the Y-direction outer sides of the plurality of X-direction extending portions, and of the plurality of through-side projections, two of the through-side projections include the Y-direction central portion of the surface and are X-direction outer end projections arranged on both the X-direction outer sides of the plurality of Y-direction extending portions, and in the arrangement step, it is preferable to arrange the plate-shaped member in the cavity of the mold such that the gate faces the X-direction outer end projections.

[0035] The composite component for fuel cells manufactured using this configuration has the same effects as the configuration described in (3) above. In the raw material injection process, the gasket raw material flows from the two X-direction outer end protrusions, through the back side arrangement portion, to the two independent portions. This configuration makes it possible to suppress variations in the flow path length when the gasket raw material flows. Therefore, it is possible to suppress the occurrence of molding defects caused by such variations.

[0036] (13) Preferably, in any of the configurations described in (10) and later, two of the multiple through-side projections are Y-direction outer end projections that include the X-direction central portion of the surface and are located on both Y-direction outer sides of the multiple X-direction extending portions.

[0037] The composite component for fuel cells manufactured by this configuration has the same effects as the configuration in (4) above. In the raw material injection process, the gasket raw material flows from the two X-direction outer end protrusions, through the front side arrangement portion, to the two Y-direction outer end protrusions. With this configuration, variations in the flow path length when the gasket raw material flows can be suppressed. Therefore, the occurrence of molding defects caused by such variations can be suppressed.

[0038] (14) Preferably, in any of the configurations described in (10) and later, the continuous portion has a branching and merging section connecting the X-direction outer end projection and the Y-direction outer end projection, and in the branching and merging section, with the direction toward the X-direction outer end projection being the upstream side and the direction toward the Y-direction outer end projection being the downstream side, the branching and merging section has an upstream main body, a downstream main body located downstream of the upstream main body, a plurality of branch portions located between the upstream main body and the downstream main body, a branching section connecting the downstream end of the upstream main body and the upstream ends of the plurality of branch portions, and a merging section connecting the downstream ends of the plurality of branch portions and the upstream end of the downstream main body, wherein at least one of the plurality of through-side projections is a merging section projection located in the merging section, and at least one of the plurality of non-through-side projections is a branch portion projection located in any of the branch portions.

[0039] The composite components for fuel cells manufactured using this configuration have the same effects as the configuration described in (5) above. In the raw material injection process, the gasket raw material flows through the branching and merging section in the direction of "X-direction outer end projection → upstream main body → branching section → multiple branch sections → merging section → downstream main body → Y-direction outer end projection". The shapes of the multiple branch sections (extension shape of the flow path, cross-sectional shape, etc.) and flow path lengths are not constant. Therefore, the flow resistance of the multiple branch sections tends to vary. Consequently, the timing at which the gasket raw material flowing through the multiple branch sections merges at the merging section also tends to vary.

[0040] In this configuration, a side projection is provided on any branch among the multiple branches. This allows the flow velocity of the gasket material in that branch to be slowed down. Therefore, by appropriately placing the side projection on the branches (one or more) where the flow velocity of the gasket material is high, variations in the flow resistance of the multiple branches can be suppressed. In other words, variations in the timing of when the gasket material flowing through the multiple branches merges at the confluence can be suppressed. Thus, the occurrence of molding defects caused by these timing variations can be suppressed.

[0041] (15) Preferably, in any of the configurations described in (10) and later, the through-side projection has a tapered shape with a through-hole in the continuous portion at its outer end in the groove width direction, and the non-through-side projection has a tapered shape with a non-through-hole in the continuous portion at its outer end in the groove width direction.

[0042] The composite component for fuel cells manufactured by this configuration has the same effects as the configuration described in (6) above. In the raw material injection process, the gasket raw material flows into the through-hole in the continuous section via the through-side projection. The through-side projection in this configuration has a tapered shape that narrows towards the outer end in the groove width direction. The through-hole in the continuous section is located at the top of the tapered portion of the through-side projection. Therefore, the gasket raw material remains in the through-side projection (flowing from the base of the through-side projection (inner end in the groove width direction) to the top of the tapered portion (outer end in the groove width direction)) before flowing into the through-hole in the continuous section via the through-side projection. Consequently, air entrapment can be suppressed. Thus, the occurrence of molding defects in the back-side configuration can be suppressed.

[0043] In the raw material injection process, the gasket material flows along the groove on the front side. The through-side projection in this configuration has a tapered shape that narrows towards the outer end in the groove width direction. Therefore, the flow width of the gasket material in the front-side configuration can be partially adjusted. The same applies to the non-through-side projection. In addition, the non-through holes within the continuous section are located at the tapered top of the non-through-side projection. Therefore, the flow depth of the gasket material in the front-side configuration can be partially adjusted.

[0044] (16) Preferably, in any of the configurations described in (10) and later, the continuous portion further has a front intervening portion interposed between a plurality of front groove portions adjacent to each other in the planar direction, and the front intervening portion has a through hole within the continuous portion and a non-through hole within the continuous portion.

[0045] The composite component for fuel cells manufactured by this configuration has the same effects as the configuration described in (7) above. With this configuration, in the raw material injection process, the gasket material can be flowed from the front side placement portion to the back side placement portion through the through-holes in the continuous portion of the front side intervening portion.

[0046] (17) Preferably, in any of the configurations described in (10) and later, the back-side arrangement portion is configured to have: a back-side groove portion recessed in the back surface, on which the seal lip of the gasket protrudes from the back surface to the back side; a groove edge portion arranged flush with the back surface, on which the back-side groove portion extends outward in the surface direction; and a back-side intervening portion recessed in the back surface, interposed between a plurality of adjacent back-side groove portions in the surface direction, on which the through-hole in the continuous portion of the front-side intervening portion opens.

[0047] The composite component for fuel cells manufactured by this configuration has the same effects as the configuration described in (8) above. With this configuration, in the raw material injection process, the gasket raw material can be directly flowed from the front intervening portion to the back intervening portion through the through-holes in the continuous portion of the front intervening portion.

[0048] (18) Preferably, in any of the configurations described in (10) and later, the configuration further includes a membrane electrode assembly having an electrolyte membrane and a pair of catalyst layers arranged on both the front and back surfaces of the electrolyte membrane, wherein in the arrangement step, the gasket is integrally molded with the plate-shaped member and the membrane electrode assembly by arranging the membrane electrode assembly together with the plate-shaped member in the cavity.

[0049] The composite fuel cell component manufactured using this configuration has the same effects as the configuration described in (9) above. With this configuration, the gasket can be integrally molded with the plate-shaped member and the membrane electrode assembly. [Effects of the Invention]

[0050] According to the composite material for fuel cells and its manufacturing method disclosed herein, a decrease in sealing performance can be suppressed. [Brief explanation of the drawing]

[0051] [Figure 1] Figure 1 is a perspective view of a fuel cell stack equipped with a composite component for a fuel cell according to the first embodiment. [Figure 2]Figure 2 is an exploded perspective view of part II of Figure 1. [Figure 3] Figure 3 is an exploded perspective view of part III of Figure 1. [Figure 4] Figure 4 is a top view of the composite member for a fuel cell according to the first embodiment. [Figure 5] Figure 5 is a top view of the first separator of the composite component for the fuel cell. [Figure 6] Figure 6 is a bottom view of the composite component for the fuel cell. [Figure 7] Figure 7 is a bottom view of the first separator of the composite component for the fuel cell. [Figure 8] Figure 8 is an enlarged view of the area within frame VIII in Figure 4. [Figure 9] Figure 9 is a cross-sectional view taken in the direction of IX-IX in Figure 8. [Figure 10] Figure 10 is an enlarged view of the area within circle X in Figure 8. [Figure 11] Figure 11 is a cross-sectional view taken along the line XI-XI in Figure 10. [Figure 12] Figure 12 is an enlarged view of the area within frame XII in Figure 8. [Figure 13] Figure 13 is a cross-sectional view taken along the XIII-XIII line in Figure 12. [Figure 14] Figure 14 is an enlarged view of the area within frame XIV in Figure 8. [Figure 15] Figure 15 is an enlarged view of the area within frame XV in Figure 14. [Figure 16] Figure 16 is a cross-sectional view taken in the direction of XVI-XVI in Figure 15. [Figure 17] Figure 17 is an enlarged view of the area within frame XVII in Figure 6. [Figure 18] Figure 18 is a top view of the second separator of the first embodiment. [Figure 19] Figure 19 is a bottom view of the second separator. [Figure 20] Figure 20 is a partial cross-sectional view of the stack shown in Figure 1, viewed in the vertical direction. [Figure 21] Figure 21 is a schematic diagram of the first stage of the arrangement process in the manufacturing method of the composite component for fuel cell according to the first embodiment. [Figure 22] Figure 22 is a schematic diagram of the second stage of the process. [Figure 23] Figure 23 is a schematic diagram of the same stage. [Figure 24] Figure 24 is a schematic diagram of the raw material injection process in the same manufacturing method. [Figure 25] Figure 25 is a partial cross-sectional view in the vertical direction of a fuel cell stack equipped with a fuel cell composite member according to the second embodiment. [Modes for carrying out the invention]

[0052] Embodiments of the composite material for fuel cells and its manufacturing method described herein will be explained below. In the following figures, the upper side corresponds to the "front side" of the disclosure, and the lower side corresponds to the "back side" of the disclosure. The left-right direction (longitudinal direction) corresponds to the "X direction" of the disclosure, and the front-back direction (short direction) corresponds to the "Y direction" of the disclosure.

[0053] <First Embodiment> [stack] First, the configuration of the fuel cell stack equipped with the fuel cell composite component of this embodiment will be briefly described. Figure 1 shows a perspective view of the fuel cell stack equipped with the fuel cell composite component of this embodiment. Figure 2 shows an exploded perspective view of part II of Figure 1. Figure 3 shows an exploded perspective view of part III of Figure 1. In Figures 1 to 3, the gasket 5 is hatched with a dotted line.

[0054] As shown in Figures 1 to 3, the stack 9 comprises a pair of end plates 90, a plurality of fuel cell composite members 1, and a plurality of second separators 7. The fuel cell composite members 1 and the second separators 7 are stacked alternately in the vertical direction (stacking direction).

[0055] As shown in Figure 2, the lower surface 7D of the second separator 7 is laminated on the upper surface 2U of the fuel cell composite member 1. Five sealing areas 22ULa, 22ULc, 22URa, 22URc, and 22UM are set on the upper surface 2U of the fuel cell composite member 1. A gasket 5 made of VMQ (vinyl methyl silicone rubber) is also placed on the upper surface 2U. The gasket 5 elastically contacts the groove portion 700D on the back side of the lower surface 7D of the second separator 7. This elastic contact isolates the five sealing areas 22ULa, 22ULc, 22URa, 22URc, and 22UM from the outside. The gasket 5 also isolates the five sealing areas 22ULa, 22ULc, 22URa, 22URc, and 22UM from each other.

[0056] As shown in Figure 3, the lower surface 2D of the fuel cell composite member 1 is laminated on the upper surface 7U of the second separator 7. Seven sealing areas 22DLa, 22DLb, 22DLc, 22DRa, 22DRb, 22DRc, and 22DM are set on the lower surface 2D. In addition, a gasket 5 integrated with the gasket 5 on the upper surface 2U is positioned on the lower surface 2D. The gasket 5 elastically contacts the upper surface 7U of the second separator 7 itself, the front groove portion 700U of the upper surface 7U, and the retaining portion housing groove portion 701U of the upper surface 7U. Through this elastic contact, the gasket 5 isolates the seven sealing areas 22DLa, 22DLb, 22DLc, 22DRa, 22DRb, 22DRc, and 22DM from the outside. Furthermore, the gasket 5 isolates the seven sealing areas 22DLa, 22DLb, 22DLc, 22DRa, 22DRb, 22DRc, and 22DM from each other.

[0057] [Composite component for fuel cell 1] Next, the configuration of the fuel cell composite member of this embodiment will be described. Figure 4 shows a top view of the fuel cell composite member of this embodiment. Figure 5 shows a top view of the first separator of the fuel cell composite member of this embodiment. Figure 6 shows a bottom view of the fuel cell composite member of this embodiment. Figure 7 shows a bottom view of the first separator of the fuel cell composite member of this embodiment. Note that in Figures 4 and 6, the gasket 5 is hatched with a dotted line. Also, in Figure 5, the non-penetrating hole 403Ua in the continuous section that does not penetrate the first separator 2 is shown in black (the inside of the hole is filled in black).

[0058] As shown in Figures 4 to 7, the fuel cell composite member 1 comprises a first separator 2, a gasket 5, and a MEGA (Membrane Electrode Gas Diffusion Layer Assembly) 6. The first separator (bipolar plate) 2 is included in the concept of a "plate-shaped member" as described herein.

[0059] (First separator 2) The first separator 2 is made of conductive resin and has a rectangular plate shape. The upper surface 2U of the first separator 2 has a rectangular shape when viewed from above. The first separator 2 comprises six manifolds 20La to 20Lc, 20Ra to 20Rc, and a gasket placement section 4.

[0060] (Manifold 20La~20Lc, 20Ra~20Rc) The six manifolds 20La~20Lc and 20Ra~20Rc each penetrate the first separator 2 in the vertical direction (front-to-back direction, stacking direction). Of these, three manifolds 20La~20Lc are arranged along the left edge of the first separator 2, from front to rear. The remaining three manifolds 20Ra~20Rc are arranged along the right edge of the first separator 2, from rear to front.

[0061] (Flow region 21ULa, 21ULc, 21URa, 21URc, 21DM) As shown by the dashed lines in Figures 4 and 5, on the upper surface (surface) 2U of the first separator 2, a flow path region 21ULa is located to the right (inward in the plane direction) of manifold 20La, a flow path region 21ULc is located to the right of manifold 20Lc, a flow path region 21URa is located to the left (inward in the plane direction) of manifold 20Ra, and a flow path region 21URc is located to the left of manifold 20Rc. In addition, a flow path region 21UM is located midway between manifold 20Lb and manifold 20Rb in the left-right direction (inward in the plane direction).

[0062] As shown by the dashed line in Figure 7, on the lower surface (back surface) 2D of the first separator 2, a flow path region 21DM is located midway between the three manifolds 20La to 20Lc on the left and the three manifolds 20Ra to 20Rc on the right. Each of these flow path regions 21ULa, 21ULc, 21URa, 21URc, and 21DM has multiple grooves (not shown) recessed for the fluid (hydrogen, air, cooling water).

[0063] (Sealable areas: 22ULa, 22ULc, 22URa, 22URc, 22UM, 22DLa, 22DLb, 22DLc, 22DRa, 22DRb, 22DRc, 22DM) As shown in Figures 4 and 5, the upper surface 2U has five sealing areas 22ULa, 22ULc, 22URa, 22URc, and 22UM. The sealing area 22ULa includes the manifold 20La and the flow path area 21ULa. The sealing area 22ULc includes the manifold 20Lc and the flow path area 21ULc. The sealing area 22URa includes the manifold 20Ra and the flow path area 21URa. The sealing area 22URc includes the manifold 20Rc and the flow path area 21URc. The sealing area 22UM includes the manifolds 20Lb and 20Rb and the flow path area 21UM.

[0064] As shown in Figure 7, the lower surface 2D has seven sealing areas 22DLa, 22DLb, 22DLc, 22DRa, 22DRb, 22DRc, and 22DM. Sealing area 22DLa includes manifold 20La. Sealing area 22DLb includes manifold 20Lb. Sealing area 22DLc includes manifold 20Lc. Sealing area 22DRa includes manifold 20Ra. Sealing area 22DRb includes manifold 20Rb. Sealing area 22DRc includes manifold 20Rc. Sealing area 22DM includes flow path area 21DM and MEGA6 (see Figure 6), which will be described later.

[0065] (Gasket placement section 4) As shown in Figures 5 and 7, the gasket placement section 4 comprises a front placement section 4U and a back placement section 4D. The gasket 5 is integrally molded into the gasket placement section 4.

[0066] (Front side placement section 4U) The front-side mounting portion 4U is located on the top surface 2U. The front-side mounting portion 4U is located around the five sealing target areas 22ULa, 22ULc, 22URa, 22URc, and 22UM.

[0067] Figure 8 shows an enlarged view of the area within frame VIII in Figure 4. Figure 9 shows a cross-sectional view of Figure 8 in the IX-IX direction. Figure 10 shows an enlarged view of the area within circle X in Figure 8. Figure 11 shows a cross-sectional view of Figure 10 in the XI-XI direction. Figure 12 shows an enlarged view of the area within frame XII in Figure 8. Figure 13 shows a cross-sectional view of Figure 12 in the XIII-XIII direction. Figure 14 shows an enlarged view of the area within frame XIV in Figure 8. Figure 15 shows an enlarged view of the area within frame XV in Figure 14. Figure 16 shows a cross-sectional view of Figure 15 in the XVI-XVI direction.

[0068] In Figure 8 and its enlarged section (Figures 10, 12, 14, and 15), the gasket 5 is shown with dotted hatching. Also, in Figure 8 and its enlarged section, the first separator 2 is shown through the gasket 5. Furthermore, in Figures 8 and 12, the non-penetrating holes 403Ua within the continuous section that do not penetrate the first separator 2 are shown in black (the inside of the holes is filled in black). As shown in Figures 5 and 8, the front-side arrangement section 4U comprises a continuous section 40U and two independent sections 41U.

[0069] (Continuous section 40U) As shown in Figure 9, the continuous section 40U is recessed in the upper surface 2U. As shown in Figures 5 and 8, the continuous section 40U comprises a front groove section 400U, a plurality of side protrusions 401U, a front outer frame section 404U, four front intervening sections 405ULa, 405ULc, 405URa, and 405URc, and four branching and merging sections A.

[0070] (Front side groove 400U) As shown in Figure 9, the seal lip 51 of the gasket 5 protrudes upward from the surface groove 400U relative to the upper surface 2U. As shown in Figure 11, the groove bottom of the surface groove 400U is located lower (deeper) than the recessed bottom of the side projection 401U. The continuous section 40U has a two-tiered bottom shape.

[0071] As shown in Figure 8, the front groove portion 400U comprises a plurality of X-direction extending portions 400UX and a plurality of Y-direction extending portions 400UY. The X-direction extending portions 400UX extend in the left-right direction. The Y-direction extending portions 400UY extend in the front-rear direction. As shown in Figure 10, the groove width W2 of the front groove portion 400U is narrower than the lip width W1 of the seal lip 51. In plan view, the top portion 510 of the seal lip 51 is located within the groove of the front groove portion 400U.

[0072] (Side protrusion 401U) As shown in Figure 8, in a plan view, the side projection 401U protrudes outward in the groove width direction from the front side groove 400U. The side projection 401U has a tapered shape, narrowing from the inside in the groove width direction to the outside in the groove width direction. The multiple side projections 401U have multiple through side projections 402U and four non-through side projections 403U. The non-through side projections 403U correspond to the "branch side projections" of this disclosure.

[0073] (Penetration side protrusion 402U) As shown in Figures 10 to 14, the through-side projection 402U has a through-hole 402Ua within the continuous section. The through-hole 402Ua is located at the outer end (tapered top) in the groove width direction of the through-side projection 402U. The through-hole 402Ua penetrates the first separator 2 in the vertical direction (front-to-back direction). The through-hole 402Ua is connected to the back-side arrangement section 4D.

[0074] As shown in Figures 5, 8, and 10-14, the multiple through-side projections 402U have two X-direction outer end projections 402UX (particularly in Figure 10), two Y-direction outer end projections 402UY (particularly in Figure 14), and four confluence side projections 402UA (particularly in Figure 12).

[0075] As shown in Figure 5, the two X-direction outer end projections 402UX are positioned on the upper surface 2U, including axis AX. Axis AX extends laterally through the front-to-back centers of the upper surface 2U and the lower surface 2D. Axis AX is included in the concept of the "Y-direction center" of this disclosure. The two X-direction outer end projections 402UX are positioned on both the left-to-right outer sides of all Y-direction extending portions 400UY. As shown in Figure 10, the X-direction outer end projections 402UX, like the other through-side projections 402U, have a triangular shape that tapers outward in the groove width direction.

[0076] As shown in Figure 5, the two Y-direction outer end projections 402UY are positioned on the upper surface 2U, including axis AY. Axis AY extends in the front-rear direction through the left-right centers of the upper surface 2U and the lower surface 2D. Axis AY is included in the concept of the "X-direction central portion" of this disclosure. The two Y-direction outer end projections 402UY are positioned on both the front-rear and outer sides of all X-direction extending portions 400UX. As shown in Figure 14, unlike the other through-side projections 402U, the Y-direction outer end projections 402UY have a shape in which the two through-side projections 402U are connected in the left-right direction. That is, the Y-direction outer end projections 402UY comprise two triangular portions 402UYa and a connecting portion 402UYb. The triangular portions 402UYa, like the other through-side projections 402U, have a triangular shape that tapers outward in the groove width direction. The two triangular sections 402UYa are spaced apart in the left-right direction, with the axis AY in between. The connecting section 402UYb is a long, strip-like shape in the left-right direction. The connecting section 402UYb straddles the axis AY and is positioned midway between the two triangular sections 402UYa. The connecting section 402UYb connects the two triangular sections 402UYa in the left-right direction. Overall, the Y-direction outer end projection 402UY has a tapered shape that tapers outward in the groove width direction.

[0077] As shown in Figure 5, the four junction side projections 402UA are arranged one by one in the four regions R1 to R4 (as shown in Figure 5, in a plan view, clockwise around the intersection O, left front region R1, left rear region R2, right rear region R3, and right front region R4) which are set up by dividing the first separator 2 by axes AX and AY. The junction side projections 402UA are located in the portion where the Y-direction ends (front end and rear end) of the Y-direction extension portion 400UY connect to the middle portion of the X-direction extension portion 400UX. The junction side projections 402UA are located in the junction A5, which will be described later.

[0078] (Non-penetrating side protrusion 403U) As shown in Figures 5, 8, and 12-13, the non-penetrating side projection (branch side projection) 403U has a non-penetrating hole 403Ua within the continuous section. The non-penetrating hole 403Ua is located at the outer end (tapered top) in the groove width direction of the non-penetrating side projection 403U. The non-penetrating hole 403Ua does not penetrate the first separator 2 in the vertical direction. The non-penetrating hole 403Ua has a bottomed recess shape.

[0079] As shown in Figure 5, the four non-penetrating side projections 403U are arranged one by one in the four regions R1 to R4. The non-penetrating side projections 403U are located next to (outward in the plane direction of) the confluence side projection 402UA. The non-penetrating side projections 403U are located in the outer branch portion A3a, which will be described later.

[0080] (Front side outer frame part 404U, front side intervening part 405ULa, 405ULc, 405URa, 405URc) As shown in Figure 5, the front outer frame portion 404U extends in a rectangular frame shape along the outer edge of the upper surface 2U. The front outer frame portion 404U has the aforementioned front groove portion 400U arranged along the direction of extension of the front outer frame portion 404U. In addition, the front outer frame portion 404U has the aforementioned side projection portion 401U that protrudes outward in the surface direction from the front groove portion 400U of the front outer frame portion 404U.

[0081] As shown in Figure 5, the four front intervening portions 405ULa, 405ULc, 405URa, and 405URc are arranged one by one in the four regions R1 to R4. The four front intervening portions 405ULa, 405ULc, 405URa, and 405URc are arranged in an L-shape on the inside of the four corners in the surface direction of the front outer frame portion 404U. Specifically, the front intervening portion 405ULa is positioned between the sealing target region 22ULa and the sealing target region 22UM. The front intervening portion 405ULc is positioned between the sealing target region 22ULc and the sealing target region 22UM. The front intervening portion 405URa is positioned between the sealing target region 22URa and the sealing target region 22UM. The front intervening portion 405URc is positioned between the sealing target region 22URc and the sealing target region 22UM.

[0082] As an example, the front intervening portion 405ULa in region R1 shown in Figure 8 is positioned between the X-direction extending portion 400UX adjacent to the sealing target region 22ULa and the X-direction extending portion 400UX adjacent to the sealing target region 22UM. Furthermore, the front intervening portion 405ULa is positioned between the Y-direction extending portion 400UY adjacent to the sealing target region 22ULa and the Y-direction extending portion 400UY adjacent to the sealing target region 22UM. In other words, the front intervening portion 405ULa is interposed between two adjacent front groove portions 400U in the planar direction.

[0083] The front intervening portion 405ULa includes a through-hole 402Ua within the continuous portion and a non-through-hole 403Ua within the continuous portion, as shown in Figure 13. The same applies to the front intervening portion 405ULc of region R2, the front intervening portion 405URa of region R3, and the front intervening portion 405URc of region R4.

[0084] (Branching and merging section A) As shown in Figure 5, the four branching and merging sections A are located one in each of the four regions R1 to R4. The four branching and merging sections A correspond to the four front intervening sections 405ULa, 405ULc, 405URa, and 405URc mentioned above.

[0085] As an example, the branching and merging section A of region R1 shown in Figure 8 connects the X-direction outer end projection 402UX of the boundary between region R1 and region R2, and the Y-direction outer end projection 402UY of the boundary between region R1 and region R4. In other words, in a plan view, branching and merging section A connects the X-direction outer end projection 402UX and the Y-direction outer end projection 402UY that are adjacent to each other in the circumferential direction of the first separator 2.

[0086] The branching and merging section A comprises an upstream main section A1, a downstream main section A2, an outer branch section A3a, an inner branch section A3b, a branch section A4, and a merging section A5. The outer branch section A3a and the inner branch section A3b are included in the concept of "branch section" in this disclosure. Here, in the branching and merging section A, the direction toward the outer end projection 402UX in the X direction is defined as the upstream side, and the direction toward the outer end projection 402UY in the Y direction is defined as the downstream side.

[0087] The upstream main section A1 is connected to the outer end projection 402UX in the X direction. The downstream main section A2 is connected to the outer end projection 402UY in the Y direction. The outer branch section A3a and the inner branch section A3b are located between the upstream main section A1 and the downstream main section A2, respectively. The outer branch section A3a bypasses the sealing target area 22ULa outward in the planar direction. The inner branch section A3a bypasses the sealing target area 22ULa inward in the planar direction. The branch section A4 connects the downstream end of the upstream main section A1, the upstream end of the outer branch section A3a, and the upstream end of the inner branch section A3b. The confluence section A5 connects the upstream end of the downstream main section A2, the downstream end of the outer branch section A3a, and the downstream end of the inner branch section A3b.

[0088] (Independent part 41U) As shown in Figure 16, the independent portion 41U is recessed in the upper surface 2U. As shown in Figures 5 and 14, on the upper surface 2U, the independent portion 41U is positioned independently from the continuous portion 40U. The two independent portions 41U are positioned on both the front-rear outer sides (both outer sides in the surface direction) of the continuous portion 40U. The two independent portions 41U are positioned in a location that includes the left-right central part (axis AY) of the upper surface 2U.

[0089] As shown in Figure 16, the independent section 41U comprises an internal through-hole 410U, a deep bottom section 411U, and a shallow bottom section 412U. The shallow bottom section 412U is recessed in the upper surface 2U. As shown in Figure 15, the shallow bottom section 412U has an elongated hole shape extending in the left-right direction. The deep bottom section 411U is recessed in the bottom surface of the shallow bottom section 412U. The internal through-hole 410U of the independent section is opened in the bottom surface of the deep bottom section 411U. The internal through-hole 410U of the independent section is connected to the rear side arrangement section 4D. Comparing the flow path cross-sectional areas, the internal through-hole 410U of the independent section is the smallest, the deep bottom section 411U is in the middle, and the shallow bottom section 412U is the largest.

[0090] As shown in Figures 5, 11, 13, and 16, the continuous section 40U and the independent section 41U are in communication via the through-hole 402Ua inside the continuous section, the rear-side arrangement section 4D, and the through-hole 410U inside the independent section. As shown in Figure 16, within the independent section 41U, the gasket 5 is positioned below the upper surface 2U. That is, the gasket 5 is positioned so as not to protrude above the upper surface 2U.

[0091] (Back side placement section 4D) As shown in Figure 7, the rear-side placement section 4D is positioned on the lower surface 2D of the first separator 2. The rear-side placement section 4D is positioned around the seven sealing target areas 22DLa, 22DLb, 22DLc, 22DRa, 22DRb, 22DRc, and 22DM.

[0092] Figure 17 shows an enlarged view of the area within frame XVII in Figure 6. Dotted hatching is applied to the gasket 5. The first separator 2 is shown through the gasket 5. As shown in Figures 7 and 17, the back side arrangement portion 4D comprises a back side groove portion 400D, a retaining portion fixing groove portion 402D, a groove edge portion 401D, a back side outer frame portion 404D, and six back side intervening portions 405DLa, 405DLb, 405DLc, 405DRa, 405DRb, and 405DRc.

[0093] (Rear side groove section 400D) As shown in Figure 9, the seal lip 51 of the gasket 5 protrudes downward from the rear groove 400D relative to the bottom surface 2D. As shown in Figure 11, the bottom of the groove 400D on the rear side is positioned above (deeper than) the bottom surface 2D (the surface on which the groove edge 401D is located).

[0094] Similar to the front groove 400U shown in Figure 10, the groove width of the back groove 400D (the same as the groove width W2 of the front groove 400U shown in Figure 10) is narrower than the lip width of the seal lip 51 (the same as the lip width W1 of the seal lip 51 shown in Figure 10). In a plan view (viewed from below), the top 510 of the seal lip 51 is located within the groove of the back groove 400D.

[0095] (Holding part fixing groove part 402D, groove edge part 401D) As shown in Figure 9, the retaining part fixing groove 402D is recessed in the lower surface 2D. As shown in Figures 7 and 17, the retaining part fixing groove 402D is positioned along the outer edge of the sealing area 22DM. As shown in Figure 9, the groove edge 401D is positioned flush with the lower surface 2D. In other words, the groove edge 401D is continuous with the lower surface 2D without any steps. The groove edge 401D extends outward in the surface direction from the back groove 400D. The groove edge 401D extends to near the outer edge of the lower surface 2D.

[0096] (Rear outer frame part 404D, rear intervening parts 405DLa, 405DLb, 405DLc, 405DRa, 405DRb, 405DRc) As shown in Figure 7, the back outer frame portion 404D extends in a rectangular frame shape along the outer edge of the bottom surface 2D. The back outer frame portion 404D has the aforementioned back groove portion 400D arranged along the direction of extension of the back outer frame portion 404D. In addition, the groove edge portion 401D is arranged on the back outer frame portion 404D, protruding outward in the surface direction from the back groove portion 400D of the back outer frame portion 404D.

[0097] Of the six back-side intervening portions 405DLa, 405DLb, 405DLc, 405DRa, 405DRb, and 405DRc, four back-side intervening portions 405DLa, 405DLc, 405DRa, and 405DRc are arranged one by one in the four regions R1 to R4. The four back-side intervening portions 405DLa, 405DLc, 405DRa, and 405DRc are arranged in an L-shape on the inside of the four corners in the planar direction of the back-side outer frame portion 404D. Specifically, the back-side intervening portion 405DLa is arranged between the sealing target region 22DLa and the sealing target regions 22DLb and 22DM. The back-side intervening portion 405DLc is arranged between the sealing target region 22DLc and the sealing target regions 22DLb and 22DM. The back-side intervening portion 405DRa is positioned between the sealing target area 22DRa and the sealing target areas 22DRb and 22DM. The back-side intervening portion 405DRc is positioned between the sealing target area 22DRc and the sealing target areas 22DRb and 22DM.

[0098] Of the remaining two back-side intervening parts 405DLb and 405DRb, back-side intervening part 405DLb connects the L-shaped corner of back-side intervening part 405DLa to the L-shaped corner of back-side intervening part 405DLc. Also, back-side intervening part 405DRb connects the L-shaped corner of back-side intervening part 405DRa to the L-shaped corner of back-side intervening part 405DRc.

[0099] The back-side intervening portion 405DLb is positioned between the sealing target area 22DLb and the sealing target area 22DM. The back-side intervening portion 405DRb is also positioned between the sealing target area 22DRb and the sealing target area 22DM.

[0100] Similar to the front intervening portion 405ULa described above, the back intervening portions 405DLa, 405DLb, 405DLc, 405DRa, 405DRb, and 405DRc are each intervened between two adjacent back groove portions 400D in the planar direction.

[0101] (Gasket 5) As shown in Figures 4, 6, 8, 11, and 17, the gasket 5 is integrally molded with the gasket placement portion 4 of the first separator 2. The gasket 5 is a single, continuous piece. The gasket 5 comprises a base portion 50, a seal lip 51, and a MEGA holding portion 52.

[0102] As shown in Figure 8, on the upper surface 2U, the base portion 50 is positioned on multiple side protrusions 401U and four front intervening portions 405ULa, 405ULc, 405URa, and 405URc of the front outer frame portion 404U. As shown in Figure 11, the top surface (upper surface) of the base portion 50 is flush with the upper surface 2U. That is, the base portion 50 is embedded in the upper surface 2U.

[0103] As shown in Figure 17, on the lower surface 2D, the base portion 50 is positioned on the groove edge portion 401D of the back outer frame portion 404D and on the six back intervening portions 405DLa, 405DLb, 405DLc, 405DRa, 405DRb, and 405DRc. As shown in Figure 11, the top surface (lower surface) of the base portion 50 is positioned below the lower surface 2D via a step. In other words, the base portion 50 is stacked on the lower surface 2D.

[0104] As shown in Figures 8, 11, and 17, the seal lip 51 is positioned along the front groove 400U and the back groove 400D. The seal lip 51 comprises a top portion 510 and a base portion 511. The top portion 510 is the protruding end of the seal lip 51. The top portion 510 is elastically in contact with the second separator 7, which will be described later. This elastic contact causes the top portion 510 to form a seal line (a linear seal portion or a strip seal portion). The base portion 511 is positioned outside the top portion 510 in the groove width direction. The base portion 511 has a slope shape. The base portion 511 connects the base portion 50 and the top portion 510.

[0105] As shown in Figures 6 and 17, the MEGA holding portion 52 is positioned around the sealing target area 22DM along the holding portion fixing groove portion 402D on the lower surface 2D. The MEGA holding portion 52 extends in a rectangular frame shape. As shown in Figure 9, the MEGA holding portion 52 includes a pair of upper and lower gripping bodies 520.

[0106] (MEGA6) As shown in Figures 6 and 17, MEGA 6 is a rectangular thin plate and is positioned on the lower surface 2D. As shown in Figure 9, the outer edge of MEGA 6 is held from above and below by a pair of gripping bodies 520 of the MEGA holding portion 52 of the gasket 5. In other words, the gasket 5 is integrally molded with the first separator 2 and MEGA 6.

[0107] MEGA6 comprises a Membrane Electrode Assembly (MEA) (not shown) 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 comprises 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.

[0108] [Second separator 7] Next, the configuration of the second separator in this embodiment will be described. Figure 18 shows a top view of the second separator in this embodiment. Figure 19 shows a bottom view of the same second separator. Figure 20 shows a partial cross-sectional view in the vertical direction of the stack shown in Figure 1. Note that Figure 20 corresponds to the IX-IX cross-section in Figure 8 (see Figure 9).

[0109] As shown in Figures 1-3 and 18-19, the second separator 7, like the first separator 2, is made of conductive resin and has a rectangular plate shape. The second separator 7 is equipped with six manifolds 70La-70Lc and 70Ra-70Rc. The six manifolds 70La-70Lc and 70Ra-70Rc are connected vertically to the six manifolds 20La-20Lc and 20Ra-20Rc of the first separator 2.

[0110] As shown in Figure 18, the upper surface 7U of the second separator 7 has a front groove 700U, a retaining part housing groove 701U, and a flow path region 71UM indicated by a dashed line. As shown in Figures 3, 7, and 20, the front groove 700U is opposite the back groove 400D of the lower surface 2D of the first separator 2. The top 510 of the seal lip 51 of the gasket 5, which is located in the back groove 400D, elastically contacts the bottom surface of the front groove 700U. This elastic contact forms a seal line. As shown in Figures 3, 7, and 20, the retaining part housing groove 701U is opposite the retaining part fixing groove 402D. The gripping body 520 of the MEGA retaining part 52 of the gasket 5, which is located in the retaining part fixing groove 402D, elastically contacts the bottom surface of the retaining part housing groove 701U. This elastic contact causes the MEGA holding portion 52 to press against the MEGA 6. Furthermore, this elastic contact forms a seal line. Thus, around the MEGA 6, there is an annular outer seal line formed by the top portion 510 of the seal lip 51 and an annular inner seal line formed by the gripping body 520. Additionally, the gasket 5 of the groove edge 401D is interposed across the entire surface between the upper surface 7U and the lower surface 2D, except for the MEGA 6. The gasket 5 of the groove edge 401D is in surface contact with the upper surface 7U. Therefore, insulation between the upper surface 7U and the lower surface 2D can be ensured.

[0111] As shown in Figure 19, the lower surface 7D of the second separator 7 has a back groove 700D and flow path regions 71DLc and 71DRc, indicated by dashed lines. As shown in Figures 2, 5, and 20, the back groove 700D faces the front groove 400U of the upper surface 2U of the first separator 2. The top 510 of the seal lip 51 of the gasket 5 located in the front groove 400U elastically contacts the bottom surface of the groove 700D. This elastic contact forms a seal line. On the other hand, the lower surface 7D is in full surface contact with the upper surface 2U. Therefore, electrical conductivity between the lower surface 7D and the upper surface 2U can be ensured.

[0112] [Manufacturing method for composite materials for fuel cells] Next, the manufacturing method for the fuel cell composite member of this embodiment will be described. The manufacturing method for the fuel cell composite member of this embodiment includes a placement step, a raw material injection step, and a mold opening step.

[0113] Figure 21 shows a schematic diagram of the first stage of the arrangement process in the manufacturing method of the fuel cell composite member of this embodiment (near the left front manifold of the first separator). Figure 22 shows a schematic diagram of the second stage of the same process (near the left front manifold of the first separator). Figure 23 shows a schematic diagram of the same stage (near the left X-direction outer end protrusion of the first separator). Figure 24 shows a schematic diagram of the raw material injection process of the same manufacturing method. Figures 21-22 and 24 correspond to the IX-IX cross section in Figure 8 (see Figure 9). Figure 23 corresponds to the XI-XI cross section in Figure 10 (see Figure 11).

[0114] (Mold) First, the configuration of the mold 8 used in the manufacturing method of the fuel cell composite member of this embodiment will be described. As shown in Figure 21, the mold 8 comprises a first mold 80 and a second mold 81. The first mold 80 can be moved toward and away from the second mold 81 from above. The molding surface 801 of the first mold 80 is provided with the shape of a gasket 5 that is integrally molded onto the front side arrangement portion 4U of the first separator 2. The molding surface 811 of the second mold 81 is provided with the shape of a gasket 5 that is integrally molded onto the back side arrangement portion 4D of the first separator 2. In addition, six bosses 811a are arranged on the molding surface 811 corresponding to the six manifolds 20La~20Lc, 20Ra~20Rc (see Figure 5) of the first separator 2. In addition, rectangular frame-shaped retaining groove portions 811b are arranged on the molding surface 811. As shown in Figure 22, in the closed state, a cavity 82 with the same shape as the gasket 5 is partitioned inside the mold 8. As shown in Figure 23, the first type 80 is equipped with gates 800. Two gates 800 are arranged on the left and right, corresponding to the two X-direction outer end protrusions 402UX of the first separator 2 shown in Figure 5.

[0115] (Placement process) In this process, MEGA6 and the first separator 2 are placed in the second mold 81 of the mold 8 in the open state. As shown in Figure 21, first, MEGA6 is placed on the molding surface 811 of the second mold 81. Next, the first separator 2 is placed above MEGA6. At this time, the six bosses 811a of the molding surface 811 are relatively inserted into the six manifolds 20La~20Lc, 20Ra~20Rc (see Figure 5) of the first separator 2.

[0116] Next, as shown in Figure 22, the first mold 80 is brought into contact with the second mold 81 from above. In other words, the mold is closed. As shown in Figure 23, the gate 800 is positioned directly above the X-direction outer end projection 402UX of the first separator 2 due to the mold closing. That is, the gate 800 faces the continuous portion 40U of the front side arrangement portion 4U.

[0117] (Raw material injection process) In this process, gasket material (specifically, liquid silicone rubber) is injected from two gates 800 into the cavity 82 (located directly above the X-direction outer end projection 402UX). As shown by arrows y1 to y4 in Figure 8, in the front-side arrangement section 4U of region R1, the material flows between the X-direction outer end projection 402UX and the Y-direction outer end projection 402UY via the branching and merging section A. Specifically, the material flows from the upstream side to the downstream side in the following order: X-direction outer end projection 402UX → upstream main section A1 → branching section A4 → outer branch section A3a and inner branch section A3b → merging section A5 → downstream main section A2 → Y-direction outer end projection 402UY. The same applies to regions R2 to R4.

[0118] As shown in Figures 5 and 8, the raw materials from region R1 (arrows y1 to y4 in Figure 8) and the raw materials from region R4 (arrow y5 in Figure 8) merge at the front Y-direction outer end projection 402UY. Similarly, the raw materials from region R2 and the raw materials from region R3 merge at the rear Y-direction outer end projection 402UY.

[0119] When the raw material flows from the gate 800 to the X-direction outer end projection 402UX, it flows into the back side arrangement section 4D through the continuous through-hole 402Ua of the X-direction outer end projection 402UX. Also, when the raw material passes through the through-side projections 402U other than the X-direction outer end projection 402UX, it flows into the back side arrangement section 4D through the continuous through-hole 402Ua. Furthermore, after the raw material merges at the Y-direction outer end projection 402UY, it flows into the back side arrangement section 4D through the two continuous through-holes 402Ua of the Y-direction outer end projection 402UY. Also, when the raw material passes through the front side intervening section 405ULa, it flows into the back side arrangement section 4D through the continuous through-hole 402Ua of the front side intervening section 405ULa. In this way, the raw material flows into the back side arrangement section 4D from various points in the front side arrangement section 4U through multiple continuous through-holes 402Ua.

[0120] As shown by arrow y6 in Figure 17, in the rear-side arrangement section 4D of region R1, the raw material diffuses in the planar direction along the shape of the cavity 82 (see Figure 24) from multiple continuous through-holes 402Ua to the bottom surface 2D. The raw material, having reached every corner of the rear-side arrangement section 4D, merges into the through-holes 410U of the independent section. The merged raw material flows through the through-holes 410U of the independent section into the independent section 41U (deep bottom section 411U, shallow bottom section 412U) shown in Figure 8. The same applies to regions R2 to R4.

[0121] As shown in Figures 7 and 17, the raw material from region R1 (arrow y6 in Figure 17) and the raw material from region R4 (arrow y7 in Figure 17) merge at the through-hole 410U inside the front independent section. As shown in Figure 16, the merged raw material (arrow y8 in Figure 16) flows into the independent section 41U from below. Similarly, the raw material from region R2 and the raw material from region R3 merge at the through-hole 410U inside the rear independent section and flow into the rear independent section 41U.

[0122] In this way, the raw material spreads throughout the cavity 82. As shown in Figure 24, the gasket 5 is formed as the raw material hardens in the cavity 82. At this time, the gasket 5 integrates with the first separator 2 and MEGA 6. In this way, the fuel cell composite member 1 is manufactured.

[0123] (Mold opening process) In this process, the first mold 80 is separated from the second mold 81, that is, the mold is opened. Then, the fuel cell composite member 1 is removed from the cavity 82. After that, as shown in Figure 1, the fuel cell composite member 1 and the second separator 7 are stacked alternately to form a laminate, and the stack 9 is assembled by sandwiching the laminate with a pair of end plates 90.

[0124] [Effects and Effects] Next, the effects of the composite component for fuel cells and its manufacturing method according to this embodiment will be described. As shown in Figures 4, 6, and 24, the gasket 5 is integrally molded with the gasket placement portion 4 of the first separator 2. Therefore, compared to a method of bonding a pre-fabricated separate gasket 5 to the first separator 2, the number of work steps can be reduced. In addition, the gasket 5 and the first separator 2 can be positioned and integrated at the same time as the molding of the gasket 5.

[0125] As shown in Figure 5, the first separator 2 has through holes 402Ua in the continuous section and through holes 410U in the independent section. This increases the contact area between the first separator 2 and the gasket 5. Therefore, even without adhesive, displacement or detachment of the gasket 5 from the first separator 2 can be suppressed. Furthermore, as shown in Figures 11 and 16, the gasket 5 is integrally molded on both the upper and lower surfaces (front and back surfaces) of the first separator 2 via the through holes 402Ua in the continuous section and the through holes 410U in the independent section. Therefore, due to the anchoring effect, displacement or detachment of the gasket 5 from the first separator 2 can be suppressed even without adhesive. In addition, the gasket 5 and the first separator 2 can be positioned and integrated simultaneously with the molding of the gasket 5. As an example, the anchoring effect enjoyed by the gasket 5 of the front-side positioning section 4U will be described. The gasket 5 on the front side (4U) is connected to the gasket 5 on the back side (4D) via the through-hole 402Ua in the continuous section and the through-hole 410U in the independent section (the gasket 5 is a single unit). Therefore, if the gasket 5 attempts to detach from the front side (4U), the gasket 5 on the back side (4D) functions like a hook's "barb," preventing it from falling off. The same applies to the anchoring effect enjoyed by the gasket 5 on the back side (4D). In the case of the gasket 5 on the back side (4D), the gasket 5 on the front side (4U) functions like a hook's "barb."

[0126] As shown in Figures 5 and 14, the independent portion 41U is independent of the continuous portion 40U, that is, the sealing target areas 22ULa, 22ULc, 22URa, 22URc, and 22UM. Furthermore, the independent portion 41U is positioned on the outside of the continuous portion 40U in the front-rear direction (surface direction). Therefore, even if a molding defect (such as burrs) occurs in the gasket 5 of the independent portion 41U, in other words, even if the shape accuracy of the gasket 5 of the independent portion 41U is low, the effect of this shape accuracy is less likely to affect the gasket 5 of the continuous portion 40U. Thus, a decrease in sealing performance caused by the gasket 5 of the independent portion 41U can be suppressed.

[0127] As shown in Figure 16, in the independent portion 41U, the gasket 5 is positioned so as not to protrude upward from the upper surface 2U of the first separator 2. Therefore, even if molding defects (such as burrs) occur in the gasket 5 of the independent portion 41U, a decrease in sealing performance caused by the gasket 5 of the independent portion 41U can be suppressed.

[0128] As shown in Figure 5, the first separator 2 is provided with a groove on the front side 400U, a projection on the through side 402U, a through hole 402Ua in the continuous section, a projection on the non-through side 403U, and a non-through hole 403Ua in the continuous section. This increases the contact area between the first separator 2 and the gasket 5. Therefore, despite not being adhesive, displacement and detachment of the gasket 5 from the first separator 2 can be suppressed.

[0129] As shown in Figure 11, the seal lip 51 of the gasket 5 (more specifically, the top portion 510 of the seal lip 51 that forms the seal line) is located above the surface groove portion 400U. On the other hand, as shown in Figure 12, the through-hole 402Ua in the continuous portion is located on the through-side projection 402U, and the non-through-hole 403Ua in the continuous portion is located on the non-through-side projection 403U. In other words, the through-hole 402Ua and non-through-hole 403Ua in the continuous portion are located to avoid the surface groove portion 400U. Therefore, even if a molding defect (such as shrinkage) occurs due to the gasket 5 of the through-hole 402Ua and non-through-hole 403Ua in the continuous portion, the effect of this molding defect is less likely to extend to the gasket 5 of the surface groove portion 400U. Thus, a decrease in sealing performance due to the gasket 5 of the through-hole 402Ua and non-through-hole 403Ua in the continuous portion can be suppressed.

[0130] As shown in Figure 5, the two independent portions 41U are positioned within the axis AY of the upper surface 2U. Furthermore, the two independent portions 41U are positioned on both the front-rear and outer sides of the multiple X-direction extending portions 400UX. In addition, as shown in Figures 15 and 16, the independent portions 41U have through holes 410U inside them. Therefore, displacement and detachment of the gasket 5 from the first separator 2 can be suppressed at the position within the axis AY of the upper surface 2U and on both the front-rear and outer sides of the front groove portion 400U.

[0131] As shown in Figure 5, the two X-direction outer end protrusions 402UX are positioned on the upper surface 2U, including the axis AX. Furthermore, the two X-direction outer end protrusions 402UX are positioned on both the left and right outer sides of the multiple Y-direction extending portions 400UY. Also, as shown in Figures 10 and 11, the X-direction outer end protrusions 402UX have through holes 402Ua within the continuous portion. Therefore, displacement and detachment of the gasket 5 from the first separator 2 can be suppressed at the position on the upper surface 2U including the axis AX, and on both the left and right outer sides of the front groove portion 400U.

[0132] As shown in Figure 5, the two Y-direction outer end projections 402UY are positioned within the axis AY of the upper surface 2U. Furthermore, the two Y-direction outer end projections 402UY are positioned on both the front-rear and outer sides of the multiple X-direction extending portions 400UX. Also, as shown in Figure 14, the Y-direction outer end projections 402UY have a pair of continuous through-holes 402Ua on the left and right sides. As a result, displacement and detachment of the gasket 5 from the first separator 2 can be suppressed at the position within the axis AY of the upper surface 2U and on both the front-rear and outer sides of the front groove portion 400U.

[0133] As shown in Figures 5 and 8, the front intervening portions 405ULa, 405ULc, 405URa, and 405URc have through-holes 402Ua and non-through-holes 403Ua within the continuous portion. This increases the contact area between the front intervening portions 405ULa, 405ULc, 405URa, and 405URc and the gasket 5. Therefore, despite not being adhesive, displacement and detachment of the gasket 5 from the front intervening portions 405ULa, 405ULc, 405URa, and 405URc can be suppressed. Furthermore, the gasket 5 is integrally molded on both the upper and lower surfaces of the first separator 2 via the through-holes 402Ua within the continuous portion. Therefore, due to the anchoring effect, displacement and detachment of the gasket 5 from the front intervening portions 405ULa, 405ULc, 405URa, and 405URc can be suppressed despite not being adhesive.

[0134] As shown in Figure 8, a confluence section A5 has a confluence section side projection 402UA. This increases the contact area between the confluence section A5 and the gasket 5. Furthermore, the gasket 5 is integrally molded on both the upper and lower surfaces of the first separator 2 through the through-hole 402Ua in the continuous portion of the confluence section side projection 402UA. This provides an anchoring effect that suppresses displacement or detachment of the gasket 5 from the confluence section A5. Additionally, a non-penetrating side projection 403U is provided on the outer branch section A3a. This increases the contact area between the outer branch section A3a and the gasket 5.

[0135] As shown in Figure 10, a through-hole 402Ua is located at the outer end of the through-side projection 402U in the groove width direction. That is, the through-hole 402Ua is located at the position furthest from the front groove portion 400U on the through-side projection 402U. Therefore, even if the shape accuracy of the gasket 5 of the through-hole 402Ua is low, the effect of this shape accuracy is less likely to affect the gasket 5 of the front groove portion 400U. Consequently, a decrease in sealing performance caused by the gasket 5 of the through-hole 402Ua can be suppressed.

[0136] As shown in Figure 12, a non-through hole 403Ua within the continuous section is located at the outer end in the groove width direction of the non-through side projection 403U. That is, the non-through hole 403Ua within the continuous section is located at the position furthest from the front groove section 400U in the non-through side projection 403U. Therefore, even if the shape accuracy of the gasket 5 of the non-through hole 403Ua within the continuous section is low, the effect of this shape accuracy is less likely to affect the gasket 5 of the front groove section 400U. Consequently, a decrease in sealing performance caused by the gasket 5 of the non-through hole 403Ua within the continuous section can be suppressed.

[0137] As shown in Figures 4 and 6, the gasket 5 on the front side of the mold is in the shape of a thin string, compared to the gasket 5 on the back side of the mold (4D). Furthermore, the gasket 5 has rubber elasticity and is flexible. For this reason, during the mold opening process, the gasket 5 on the front side of the mold (4U) is difficult to separate from the molding surface 801 of the first mold 80 shown in Figure 24. In other words, it has poor mold release properties. In this regard, the front side of the mold (4U) has multiple side protrusions 401U (through side protrusions 402U, non-through side protrusions 403U). Therefore, the mold release properties of the gasket 5 from the molding surface 801 can be improved.

[0138] As shown in Figure 4, all side protrusions 401U are located on the front outer frame portion 404U. Therefore, compared to the case where the side protrusions 401U are located on the front intervening portions 405ULa, 405ULc, 405URa, and 405URc, the flow path regions 21ULa, 21ULc, 21URa, 21URc, and 21DM can be made wider.

[0139] As shown in Figure 4, all side protrusions 401U extend outward in the surface direction from the front groove portion 400U of the front outer frame portion 404U. Therefore, compared to the case where the side protrusions 401U extend inward in the surface direction from the front groove portion 400U of the front outer frame portion 404U, the flow path regions 21ULa, 21ULc, 21URa, 21URc, and 21DM can be widened.

[0140] As shown in Figures 7, 9, and 17, the rear side arrangement portion 4D has a groove edge portion 401D that is flush with the lower surface 2D of the first separator 2. Therefore, a surface seal portion (planar seal portion) can be arranged on the lower surface 2D by the gasket 5 of the groove edge portion 401D. Specifically, as shown in Figure 20, a wide-area frame-shaped surface seal portion can be formed between the outer edge of the lower surface 2D of the first separator 2 and the outer edge of the upper surface 7U of the second separator 7. In the surface seal portion, the gasket 5 is in full surface contact with the upper surface 7U.

[0141] As shown in Figures 7 and 17, the back-side mounting portion 4D has through-holes 402Ua within the continuous portion of the front-side mounting portion 4U. This increases the contact area between the first separator 2 and the gasket 5. Furthermore, due to the anchoring effect, displacement and detachment of the gasket 5 from the back-side mounting portion 4D can be suppressed despite the lack of adhesive. In particular, the back-side intervening portions 405DLa, 405DLb, 405DLc, 405DRa, 405DRb, and 405DRc have through-holes 402Ua within the continuous portion of the front-side intervening portions 405ULa, 405ULc, 405URa, and 405URc. Therefore, the contact area between the first separator 2 and the gasket 5 can be increased between the front intervening portions 405ULa, 405ULc, 405URa, 405URc and the back intervening portions 405DLa, 405DLb, 405DLc, 405DRa, 405DRb, 405DRc. Furthermore, due to the anchoring effect, displacement and detachment of the gasket 5 from the back intervening portions 405DLa, 405DLb, 405DLc, 405DRa, 405DRb, 405DRc can be suppressed despite the lack of adhesive.

[0142] As shown in Figures 10, 11, and 15-17, when integrally molding the gasket 5 into the back side mounting section 4D during the raw material injection process, the raw material for the gasket 5 flows from the front side mounting section 4U into the back side mounting section 4D through a plurality of continuous through-holes 402Ua. The raw material that has flowed through the back side mounting section 4D reaches the independent section 41U (deep bottom section 411U, shallow bottom section 412U) through the independent section through-holes 410U. Therefore, molding defects caused by flow (voids, slag, short molds, etc.) can be concentrated in the independent section 41U. Thus, the occurrence of molding defects in the back side mounting section 4D can be suppressed.

[0143] As shown in Figure 23, when integrally molding the gasket 5 into the rear side mounting portion 4D, the raw material for the gasket 5 flows into the through-hole 402Ua in the continuous portion via the through-side projection 402U. By passing the raw material through the through-side projection 402U, it is possible to suppress the entrapment of air when the raw material flows into the through-hole 402Ua in the continuous portion. Therefore, it is possible to suppress the occurrence of molding defects (such as voids) in the rear side mounting portion 4D.

[0144] As shown in Figures 10, 11, 15 to 17, when integrally molding the gasket 5 into the back side placement section 4D during the raw material injection process, the raw material for the gasket 5 flows from the two X-direction outer end protrusions 402UX, through the back side placement section 4D, to the two independent sections 41U.

[0145] As shown in Figure 5, the two independent portions 41U are located at positions including axis AY and are positioned on both the front-rear and outer sides of the multiple X-direction extending portions 400UX. Similarly, the two X-direction outer end protrusions 402UX are located at positions including axis AX and are positioned on both the left-right and outer sides of the multiple Y-direction extending portions 400UY. Thus, in a plan view, the two independent portions 41U and the two X-direction outer end protrusions 402UX are evenly spaced near the outer edge of the upper surface 2U, with a central angle (central angle centered at intersection O) of 90° each. Therefore, variations in the flow path length when the gasket material flows can be suppressed. Consequently, the occurrence of molding defects (such as weld lines) caused by such variations can be suppressed.

[0146] As shown in Figures 8 and 23, during the raw material injection process, the raw material for the gasket 5 flows from the two X-direction outer end protrusions 402UX, through the front side arrangement portion 4U, to the two Y-direction outer end protrusions 402UY. As shown in Figure 5, the two Y-direction outer end protrusions 402UY are located at a position including axis AY, and are positioned on both the front-to-back outer sides of the multiple X-direction extending portions 400UX. Furthermore, the two X-direction outer end protrusions 402UX are located at a position including axis AX, and are positioned on both the left-to-right outer sides of the multiple Y-direction extending portions 400UY. Thus, in a plan view, the two Y-direction outer end protrusions 402UY and the two X-direction outer end protrusions 402UX are evenly arranged near the outer edge of the upper surface 2U, spaced 90° apart at central angles. Therefore, variations in the flow path length when the raw material for the gasket 5 flows can be suppressed. Consequently, the occurrence of molding defects (such as weld lines) caused by such variations can be suppressed.

[0147] As shown in Figure 8, the Y-direction outer end projection 402UY protrudes forward (outward in the surface direction) from the X-direction extending portion 400UX and has a long, band-like shape in the left-right direction. Therefore, the flow path width of the continuous portion 40U is expanded in the section where the Y-direction outer end projection 402UY is located. Consequently, even if there is variation in the flow path length when the gasket material flows through the continuous portion 40U, the Y-direction outer end projection 402UY can absorb this variation.

[0148] As shown in Figures 8 and 12, when the gasket 5 is integrally molded into the front side arrangement portion 4U during the raw material injection process, the raw material for the gasket 5 flows through the branching and merging section A in the direction of "X-direction outer end projection 402UX → upstream main body A1 → branching section A4 → outer branch A3a, inner branch A3b → merging section A5 → downstream main body A2 → Y-direction outer end projection 402UY". Here, the shape of the outer branch A3a and inner branch A3b (extended flow path shape, cross-sectional shape, etc.) and flow path length are not constant. If the non-penetrating side projection 403U is not present, the flow resistance of the outer branch A3a is smaller than that of the inner branch A3b. Therefore, the raw material for the gasket 5 flowing through the outer branch A3a reaches the merging section A5 faster than the raw material flowing through the inner branch A3b. Therefore, the flow of raw material that flows through the inner branch A3b and reaches the confluence A5 is obstructed by the flow of raw material that flows through the outer branch A3a and reaches the confluence A5, and then passes through the confluence A5.

[0149] In this regard, a non-penetrating projection 403U is provided on the outer branch A3a (upstream of the confluence A5). This increases the flow resistance of the outer branch A3a, which in turn slows down the flow velocity of the raw material. Consequently, variations in the timing of the confluence of the gasket 5 raw materials flowing through the outer branch A3a and inner branch A3b at the confluence A5 can be suppressed. This suppresses the occurrence of molding defects (such as weld lines) caused by these timing variations. To increase the flow resistance of the inner branch A3b, a non-penetrating projection 403U is provided on the inner branch A3b. In this way, by providing a non-penetrating projection 403U on any branch (outer branch A3a, inner branch A3b), variations in flow resistance between the outer branch A3a and the inner branch A3b can be suppressed.

[0150] As shown in Figure 8, when the gasket 5 is integrally molded into the back side mounting section 4D during the raw material injection process, the raw material for the gasket 5 flows into the through-hole 402Ua in the continuous section via the through-side projection 402U. The through-side projection 402U has a tapered shape that narrows towards the outer end in the groove width direction. The through-hole 402Ua in the continuous section is located at the tapered top of the through-side projection 402U. Therefore, the raw material for the gasket 5 remains in the through-side projection 402U (flowing from the base of the through-side projection 402U (inner end in the groove width direction) to the tapered top (outer end in the groove width direction)) before flowing into the through-hole 402Ua in the continuous section via the through-side projection 402U. Thus, air entrapment can be suppressed. As a result, molding defects (such as voids) in the back side mounting section 4D can be suppressed.

[0151] As shown in Figure 8, during the raw material injection process, when the gasket 5 is integrally molded into the front side placement portion 4U, the raw material for the gasket 5 flows along the front side groove portion 400U. The through-side projection 402U has a tapered shape that narrows towards the outer end in the groove width direction. Therefore, the flow width of the raw material for the gasket 5 in the front side placement portion 4U can be partially adjusted. The same applies to the non-through-side projection 403U. In addition, the non-through hole 403Ua in the continuous portion is located at the tapered top of the non-through-side projection 403U. Therefore, the flow depth of the raw material for the gasket 5 in the front side placement portion 4U can be partially adjusted.

[0152] As shown in Figures 5 and 8, the front intervening portions 405ULa, 405ULc, 405URa, and 405URc each have a through-hole 402Ua within the continuous portion and a non-through-hole 403Ua within the continuous portion. Therefore, in the raw material injection process, the raw material for the gasket 5 can be flowed from the front placement portion 4U to the back placement portion 4D through the through-hole 402Ua within the continuous portion of the front intervening portions 405ULa, 405ULc, 405URa, and 405URc. In addition, the flow rate of the raw material flowing through the front intervening portions 405ULa, 405ULc, 405URa, and 405URc (i.e., the inner branch portion A3b) can be adjusted by the through-hole 402Ua and the non-through-hole 403Ua within the continuous portion.

[0153] As shown in Figure 23, during the placement process, the gate 800 faces the X-direction outer end projection 402UX (through hole 402Ua in the continuous section). The gate 800 does not face the front groove 400U. Therefore, it is possible to suppress the retention of gate marks on the gasket 5 (especially the seal lip 51) of the front groove 400U.

[0154] The raw material for the gasket 5 used in the raw material injection process is liquid silicone rubber. Liquid silicone rubber has low viscosity and high fluidity. Therefore, the gasket 5 can be placed and molded in one go in the gasket placement area 4 (front placement area 4U, back placement area 4D) set across the upper surface 2U and lower surface 2D of the first separator 2. In addition, damage to the first separator 2 and MEGA 6, which are pre-placed in the cavity 82, can be suppressed.

[0155] As shown in Figure 21, during the placement process, the MEGA 6 is placed in the cavity 82 together with the first separator 2. Therefore, the gasket 5 can be integrally molded with the first separator 2 and the MEGA 6.

[0156] As shown in Figure 20, the flow path region 21DM on the lower surface 2D side (anode side) of the first separator 2 and the flow path region 71UM on the upper surface 7U side (cathode side) of the second separator 7 are opposite each other in the vertical direction with MEGA 6 in between. Flow path region 21DM communicates with manifold 20La via a through hole (not shown) and flow path region 21ULa. Furthermore, flow path region 21DM communicates with manifold 20Ra via a through hole (not shown) and flow path region 21URa. Air (oxygen) is supplied to flow path region 21DM. Flow path region 71UM communicates with manifold 20Lc via a through hole (not shown) and flow path region 21ULc. Furthermore, flow path region 71UM communicates with manifold 20Rc via a through hole (not shown) and flow path region 21URc. Hydrogen is supplied to flow path region 21DM. The flow path region 21UM is connected to the manifolds 20Lb and 20Rb. Cooling water is supplied to the flow path region 21UM. Thus, the stack 9 is mainly composed of only two types of components: the fuel cell composite component 1 and the second separator 7. According to the stack 9 of this embodiment, the number of parts is reduced.

[0157] <Second Embodiment> The difference between the fuel cell composite member and its manufacturing method in this embodiment and the fuel cell composite member and its manufacturing method in the first embodiment is that MEGA is not integrated into the fuel cell composite member. Here, only the differences will be explained.

[0158] Figure 25 shows a vertical cross-sectional view of a fuel cell stack equipped with the fuel cell composite member of this embodiment. The same reference numerals are used for parts corresponding to those in Figure 20. As shown in Figure 25, a frame-shaped gripping piece 520a is joined to the outer edge of the MEGA 6. The gripping piece 520a is made of VMQ, similar to the gasket 5. The gripping piece 520a is a separate component of one of the pair of gripping bodies 520 of the MEGA holding portion 52 of the gasket 5 shown in Figure 9 (specifically, the gripping body 520 protruding downward from the lower surface 2D).

[0159] The manufacturing method for the fuel cell composite member 1 of this embodiment includes a joining step in addition to the aforementioned arrangement step, raw material injection step, and mold opening step. The manufacturing method for the fuel cell composite member 1 of this embodiment will be explained with reference to Figures 21 to 24. Note that the molding surface 811 of the second mold 81 of the mold 8 does not have a recessed holding part molding groove 811b.

[0160] In the placement process, as shown in Figure 21, the first separator 2 is placed in the second mold 81 of the mold 8 in the open state, and the mold is closed as shown in Figure 22. In the raw material injection process, the gasket raw material is injected from the two gates 800 into the cavity 82 (directly above the outer end projection 402UX in the X direction). The raw material spreads throughout the cavity 82 and hardens. This hardening forms the gasket 5. At this time, the gasket 5 becomes integrated with the first separator 2. In the mold opening process, the mold is opened and the first separator 2 with the integrated gasket 5 is removed from the cavity 82. In the joining process, the MEGA 6 is placed on the inside of the MEGA holding portion 52 of the gasket 5 in the surface direction, and the gripping piece 520a is joined to the MEGA holding portion 52. At this time, the gripping piece 520a covers the outer edge of the MEGA 6 from below. Subsequently, as shown in Figure 1, the fuel cell composite member 1 and the second separator 7 are stacked alternately to form a laminate, and the stack 9 is assembled by sandwiching the laminate between a pair of end plates 90.

[0161] The fuel cell composite member and its manufacturing method of this embodiment and the fuel cell composite member and its manufacturing method of the first embodiment have similar effects with respect to parts that share a common structure. As in this embodiment, the gasket 5 may be integrally molded with the first separator 2, and then the MEGA 6 may be attached to the first separator 2.

[0162] <Other> Embodiments of the fuel cell composite member and its manufacturing method described herein have been explained above. However, the embodiments are not particularly limited to the above forms. Various modified and improved forms can be implemented by those skilled in the art.

[0163] The shape, position, size, and number of the side protrusions 401U (through side protrusions 402U, non-through side protrusions 403U) (hereinafter abbreviated as "shape, etc.") are not particularly limited. As shown in Figure 11, the bottom surface of the side protrusion 401U may be positioned shallower than the bottom surface of the groove of the front side groove 400U. Alternatively, the bottom surface of the side protrusion 401U may be flush with the bottom surface of the groove of the front side groove 400U. As shown in Figure 10, the shape of the side protrusion 401U may be tapered in plan view. Alternatively, the shape of the side protrusion 401U may be trapezoidal, rectangular, or arc-shaped in plan view. The shapes of multiple side protrusions 401U may or may not be the same. As shown in Figure 5, the side protrusions 401U may be arranged on the front outer frame 404U. Alternatively, the side projections 401U may be arranged on the front intervening portions 405ULa, 405ULc, 405URa, and 405URc. As shown in Figure 5, the side projections 401U may protrude outward in the planar direction from the front outer frame portion 404U. Alternatively, the side projections 401U may protrude inward in the planar direction from the front outer frame portion 404U.

[0164] The shape of the through-hole 402Ua within the continuous section in the through-side projection 402U is not particularly limited. The shape of the non-through-hole 403Ua within the continuous section in the non-through-side projection 403U is not particularly limited. The non-through-side projection 403U may be placed in a location other than the branch section (outer branch section A3a, inner branch section A3b). The through-hole 402Ua within the continuous section and the non-through-hole 403Ua within the continuous section do not have to be placed in the side projection 401U. The side projection 401U does not have to be placed in the front side arrangement section 4U. The shape of the continuous section 40U and the independent section 41U is not particularly limited. For example, on the upper surface 2U, the two independent sections 41U may be placed on both the left and right outer sides (both outer sides in the surface direction) of the continuous section 40U. Alternatively, the two independent sections 41U may be placed at a position that includes the front-to-back center of the upper surface 2U (axis AX). The independent section 41U only needs to be independent from the continuous section 40U on the upper surface 2U.

[0165] The position of the continuous section 40U relative to the gate 800 in the placement process is not particularly limited. For example, the gate 800 may have a through-side projection 402U (including through-side projections 402U other than the X-direction outer end projection 402UX). In this case, as shown in Figure 23, the through-hole 402Ua inside the continuous section may be positioned opposite the gate 800. Alternatively, the gate 800 may not have a through-hole 402Ua inside the continuous section. The relative sizes of the exit (downstream end) of the gate 800 and the entrance (upstream end) of the through-hole 402Ua inside the continuous section are not particularly limited. The exit of the gate 800 may be larger or smaller in diameter than the entrance of the through-hole 402Ua inside the continuous section. Alternatively, the exit and entrance may be the same diameter. Furthermore, parts other than the through-side projection 402U (such as the front outer frame portion 404U, front intervening portions 405ULa, 405ULc, 405URa, 405URc, and non-through-side projection 403U) may be positioned opposite the gate 800. In this case, the gate 800 may be positioned opposite the continuous through-holes 402Ua or the continuous non-through-holes 403Ua located in these portions. Also, multiple gates 800 may be arranged in the mold 8.

[0166] The arrangement direction of the stack 9 shown in Figure 1 is not particularly limited. The stacking direction of the fuel cell composite member 1 and the second separator 7 may be inverted vertically relative to Figure 1. Of course, the stacking direction may be horizontal, vertical, or oblique to the horizontal. The shapes of the first separator 2 and the second separator 7 are not particularly limited. In plan view, they may be rectangular, square, or the like.

[0167] The materials of the first separator 2 and the second separator 7 are not particularly limited. Any material that is conductive and non-corrosive, such as resin or metal, may be used. Examples include stainless steel, titanium, copper, magnesium, aluminum, carbon, graphite, ceramics, and conductive resins (thermoplastic resins or thermosetting resins containing carbon, graphite, polyacrylonitrile-based carbon fibers, etc.).

[0168] The material of gasket 5 is not particularly limited. Any elastomer with insulating and rubber elasticity is acceptable. It is sufficient that it has fluidity at the raw material stage. In addition to the rubber component, gasket 5 may also contain crosslinking agents, co-crosslinking agents, processing aids, softeners, reinforcing materials, etc. Suitable rubber components include VMQ (silicone rubber), as well as other silicone rubbers (PVMQ (phenyl vinyl methyl silicone rubber), FVMQ (fluoro vinyl methyl silicone rubber), etc.), EPDM (ethylene propylene diene rubber), FKM (fluororubber), etc. When liquid silicone rubber is used as a raw material, 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]

[0169] 1: Composite components for fuel cells 2: First separator (plate-shaped member), 20La~20Lc: Manifold, 20Ra~20Rc: Manifold 2U: Top surface (surface), 21ULa: Flow channel area, 21ULc: Flow channel area, 21URa: Flow channel area, 21URc: Flow channel area, 21UM: Flow channel area, 22ULa: Area to be sealed, 22ULc: Area to be sealed, 22URa: Area to be sealed, 22URc: Area to be sealed, 22UM: Area to be sealed 2D: Bottom surface (back side), 21DM: Flow channel area, 22DLa: Sealing area, 22DLb: Sealing area, 22DLc: Sealing area, 22DRa: Sealing area, 22DRb: Sealing area, 22DRc: Sealing area, 22DM: Sealing area 4: Gasket placement section, 4U: Front side placement section, 40U: Continuous section, 400U: Front side groove section, 400UX: X-direction extension section, 400UY: Y-direction extension section, 401U: Side projection section, 402U: Through side projection section, 402UA: Confluence side projection section, 402UX: X-direction outer end side projection section, 402UY: Y-direction outer end side projection section, 402UYa: Triangular section, 402UYb: Continuous section, 402Ua: Through hole inside continuous section, 403U: Non-through side projection section (branch side projection section), 403Ua: Non-through hole inside continuous section, 404U: Front side outer frame section, 405UL a: Front side intervening part, 405ULc: Front side intervening part, 405URa: Front side intervening part, 405URc: Front side intervening part, 41U: Independent part, 410U: Through hole in independent part, 411U: Deep bottom part, 412U: Shallow bottom part, 4D: Back side arrangement part, 400D: Back side groove part, 40 1D: Groove edge, 402D: Holding part fixing groove, 404D: Back side outer frame, 405DLa: Back side intervening part, 405DLb: Back side intervening part, 405DLc: Back side intervening part, 405DRa: Back side intervening part, 405DRb: Back side intervening part, 405DRc: Back side intervening part 5: Gasket, 50: Base, 51: Seal lip, 510: Top, 511: Bottom, 52: MEGA holding part, 520: Gripping body, 520a: Gripping piece, 6: MEGA, 7: Second separator, 70La~70Lc: Manifold, 70Ra~70Rc: Manifold, 7U: Top surface, 700U: Front groove, 701U: Holding part housing groove, 71UM: Flow path area, 7D: Bottom surface, 700D: Back groove, 71DLc: Flow path area, 71DRc: Flow path area, 8: Mold, 80: First mold, 800: Gate, 801: Molding surface, 81: Second mold, 811: Molding surface, 811a: Boss, 811b: Groove for holding part molding, 82: Cavity, 9: Stack, 90: End plate A: Branching / merging section, A1: Upstream main section, A2: Downstream main section, A3a: Outer branch section (branch section), A3b: Inner branch section (branch section), A4: Branching section, A5: Merging section, AX: Axis (center in the Y direction), AY: Axis (center in the X direction), O: Intersection, R1~R4: Region, W1: Lip width, W2: Groove width

Claims

1. A composite member for a fuel cell comprising a plate-shaped member having a gasket arrangement portion and a gasket integrally molded with the gasket arrangement portion, The gasket arrangement portion has a front arrangement portion that is arranged on the surface of the plate-shaped member and a back arrangement portion that is arranged on the back surface of the plate-shaped member. The front-side arrangement portion includes a continuous portion recessed in the surface and arranged around the desired sealing area, and an independent portion recessed in the surface and arranged independently of the continuous portion and on the outer side in the surface direction of the continuous portion. The continuous portion has a through-hole that penetrates the plate-shaped member in the front-back direction and connects to the rear-side arrangement portion. The independent portion has an internal through-hole that penetrates the plate-shaped member in the front-back direction and connects to the rear-side arrangement portion. The continuous portion and the independent portion are in communication via the through-holes within the continuous portion, the rear-side arrangement portion, and the through-holes within the independent portion. A composite member for a fuel cell, characterized in that the gasket is arranged inside the independent portion so as not to protrude from the surface to the front side.

2. The continuous portion has a front groove portion on which the seal lip of the gasket protrudes outward from the surface, and a plurality of side protrusions protruding outward in the groove width direction from the front groove portion. The composite member for a fuel cell according to claim 1, wherein the plurality of side protrusions include a plurality of through side protrusions having through holes within the continuous portion, and a plurality of non-through side protrusions having non-through holes within the continuous portion that do not penetrate the plate-shaped member in the front-back direction.

3. The aforementioned surface has a rectangular shape when viewed from above. Of the surface directions, the longitudinal direction is the X direction and the transverse direction is the Y direction, The aforementioned surface groove portion has a plurality of X-direction extending portions and a plurality of Y-direction extending portions, The independent portion includes the central portion in the X direction of the surface, and two of them are arranged on both the outer sides in the Y direction of the plurality of X-extending portions. The composite member for a fuel cell according to claim 2, wherein of the plurality of through-side projections, two of the through-side projections include the Y-center portion of the surface and are X-side projections arranged on both the X-outer sides of the plurality of Y-extending portions.

4. The composite member for a fuel cell according to claim 3, wherein of the plurality of through-side projections, two of the through-side projections include the central portion in the X direction of the surface and are Y-direction outer end projections arranged on both Y-direction outer sides of the plurality of X-direction extending portions.

5. The continuous section has a branching and merging section that connects the X-direction outer end projection and the Y-direction outer end projection. In the aforementioned branching and merging section, the direction toward the outer end projection in the X direction is considered the upstream side, and the direction toward the outer end projection in the Y direction is considered the downstream side. The branching and merging section comprises an upstream main body connected to the X-direction outer end projection, a downstream main body located downstream of the upstream main body and connected to the Y-direction outer end projection, a plurality of branch sections located between the upstream main body and the downstream main body, a branching section connecting the downstream end of the upstream main body and the upstream ends of the plurality of branch sections, and a merging section connecting the downstream ends of the plurality of branch sections and the upstream end of the downstream main body. Of the multiple through-side projections, at least one of the through-side projections is a confluence-side projection located at the confluence, The composite member for a fuel cell according to claim 4, wherein at least one of the plurality of non-penetrating side projections is a branch side projection that is arranged on any of the branch portions.

6. The aforementioned through-side projection has a tapered shape with a through-hole in the continuous portion at its outer end in the groove width direction. The composite member for a fuel cell according to claim 2, wherein the non-penetrating side projection has a tapered shape with a non-penetrating hole in the continuous portion at its outer end in the groove width direction.

7. The continuous portion further has a front intervening portion interposed between a plurality of front groove portions adjacent to each other in the planar direction. The composite member for a fuel cell according to claim 2, wherein the front intervening portion has through holes within the continuous portion and non-through holes within the continuous portion.

8. The composite member for a fuel cell according to claim 7, wherein the rear side arrangement portion comprises a rear side groove portion recessed in the rear surface and on which the seal lip of the gasket protrudes from the rear surface to the rear side; a groove edge portion arranged flush with the rear surface and extending outward from the rear side groove portion in the surface direction; and a rear side intervening portion recessed in the rear surface and interposed between a plurality of adjacent rear side groove portions in the surface direction, on which the through-hole in the continuous portion of the front side intervening portion opens.

9. Furthermore, the membrane electrode assembly comprises an electrolyte membrane disposed on the back surface of the plate-shaped member, and a pair of catalyst layers disposed on both the front and back surfaces of the electrolyte membrane, The composite member for a fuel cell according to claim 1, wherein the gasket is integrally molded with the plate-shaped member and the membrane electrode assembly.

10. A method for manufacturing a composite member for a fuel cell according to claim 1, A positioning step of arranging the plate-shaped member in the cavity of the mold such that the gate of the mold faces the continuous portion, A raw material injection step comprising injecting the gasket material into the cavity from the gate, allowing the material to flow into the continuous section, allowing the material to flow from the continuous section to the back-side arrangement section through through holes in the continuous section, and allowing the material to flow from the back-side arrangement section to the independent section through through holes in the independent section, A method for manufacturing a composite component for a fuel cell having the following characteristics.

11. The continuous portion has a front groove portion on which the seal lip of the gasket protrudes outward from the surface, and a plurality of side protrusions protruding outward in the groove width direction from the front groove portion. The method for manufacturing a composite member for a fuel cell according to claim 10, wherein the plurality of side protrusions include a plurality of through side protrusions having through holes within the continuous portion and a plurality of non-through side protrusions having non-through holes within the continuous portion that do not penetrate the plate-shaped member in the front-back direction.

12. The aforementioned surface has a rectangular shape when viewed from above. Of the surface directions, the longitudinal direction is the X direction and the transverse direction is the Y direction, The aforementioned surface groove portion has a plurality of X-direction extending portions and a plurality of Y-direction extending portions, The independent portion includes the central portion in the X direction of the surface, and two of them are arranged on both the outer sides in the Y direction of the plurality of X-extending portions. Of the multiple through-side projections, two of the through-side projections include the center portion in the Y direction of the surface and are X-direction outer end projections arranged on both the X-direction outer sides of the multiple Y-direction extending portions. The method for manufacturing a composite member for a fuel cell according to claim 11, wherein in the arrangement step, the plate-shaped member is arranged in the cavity such that the gate faces the outer end projection in the X direction.

13. The method for manufacturing a composite member for a fuel cell according to claim 12, wherein of the plurality of through-side projections, two of the through-side projections include the central portion in the X direction of the surface and are Y-direction outer end projections arranged on both Y-direction outer sides of the plurality of X-direction extending portions.

14. The continuous section has a branching and merging section that connects the X-direction outer end projection and the Y-direction outer end projection. In the aforementioned branching and merging section, the direction toward the outer end projection in the X direction is considered the upstream side, and the direction toward the outer end projection in the Y direction is considered the downstream side. The branching and merging section comprises an upstream main body connected to the X-direction outer end projection, a downstream main body located downstream of the upstream main body and connected to the Y-direction outer end projection, a plurality of branch sections located between the upstream main body and the downstream main body, a branching section connecting the downstream end of the upstream main body and the upstream ends of the plurality of branch sections, and a merging section connecting the downstream ends of the plurality of branch sections and the upstream end of the downstream main body. Of the multiple through-side projections, at least one of the through-side projections is a confluence-side projection located at the confluence, The method for manufacturing a composite member for a fuel cell according to claim 13, wherein at least one of the plurality of non-penetrating side projections is a branch side projection that is arranged on any of the branch portions among the plurality of branch portions.

15. The aforementioned through-side projection has a tapered shape with a through-hole in the continuous portion at its outer end in the groove width direction. The method for manufacturing a composite member for a fuel cell according to claim 11, wherein the non-penetrating side projection has a tapered shape with a non-penetrating hole in the continuous portion at its outer end in the groove width direction.

16. The continuous portion further has a front intervening portion interposed between a plurality of front groove portions adjacent to each other in the planar direction. The method for manufacturing a composite member for a fuel cell according to claim 11, wherein the front intervening portion has through holes within the continuous portion and non-through holes within the continuous portion.

17. The method for manufacturing a composite member for a fuel cell according to claim 16, wherein the rear side arrangement portion comprises a rear side groove portion recessed in the rear surface and on which the seal lip of the gasket protrudes from the rear surface to the rear side; a groove edge portion arranged flush with the rear surface and extending outward from the rear side groove portion in the surface direction; and a rear side intervening portion recessed in the rear surface and interposed between a plurality of adjacent rear side groove portions in the surface direction, on which the through-hole in the continuous portion of the front side intervening portion opens.

18. Furthermore, the membrane electrode assembly comprises an electrolyte membrane disposed on the back surface of the plate-shaped member, and a pair of catalyst layers disposed on both the front and back surfaces of the electrolyte membrane, In the aforementioned arrangement step, the film electrode assembly is placed in the cavity together with the plate-shaped member, The method for manufacturing a composite member for a fuel cell according to claim 10, wherein the gasket is integrally molded with the plate-shaped member and the membrane electrode assembly.

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