Stack manifold

Abstract

To provide a stack manifold capable of preventing an occurrence of a resin floating in an end plate.SOLUTION: A stack manifold includes: a first end plate, which is one of a pair of end plates sandwiching, in a thickness direction, a cell stacked body in which a plurality of plate-shaped unit cells are stacked in the thickness direction; and a piping member attached to the first end plate. The pipe member is made of a thermoplastic resin. The first end plate includes: a plate body made of a high-strength material and provided with a through hole communicating with a flow hole formed as a passage through which a fluid flows in the cell stack and penetrating in the thickness direction; and a thermoplastic resin part integrated with the plate body. The resin part has a cylindrical covering part covering an inner peripheral surface of the through hole in the plate body. The covering part includes: a cylindrical part disposed so as to be in contact with an inner peripheral surface of the through hole in the plate body; and a flange part exposed to an outer side in the thickness direction from an outer end in the thickness direction of the plate body. The plate body and the covering part have a restricting structure that restricts the flange part from being deformed outward in the thickness direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a stack manifold for use in, for example, a fuel cell stack. [Background technology]

[0002] Conventionally, stack manifolds for use in fuel cell stacks have been known (for example, Patent Documents 1 and 2). Such stack manifolds include a first end plate, which is one of a pair of end plates that sandwich a cell stack in the thickness direction. This first end plate has a plate-shaped metal plate and a resin portion provided on the end surface of the metal plate in the thickness direction. The metal plate has a plurality of through holes formed therethrough in the thickness direction. The resin portion also covers the inner circumferential surfaces of the through holes in the metal plate.

[0003] In the stack manifold described in Patent Document 1, a metal plate is set in a mold, and then resin is injected into the mold to form a first end plate in which the metal plate and a resin portion are integrated. Furthermore, the stack manifold described in Patent Document 2 employs a structure that prevents gaps from forming between the resin portion of the first end plate and the metal plate due to thermal shrinkage of the resin portion after molding (so-called resin floating). In this structure, the resin portion has a main body portion that extends in the thickness direction along the inner circumferential surface of the through hole in the metal plate, a flange portion that extends radially outward from the outer end of the main body portion in the thickness direction, and a folded portion that is folded back from the outer end of the flange portion in the radial direction and extends inward in the thickness direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6657974 [Patent Document 2] Patent No. 6776969 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the stack manifold structure described in Patent Document 2 only has folded portions extending inward in the thickness direction from the radially outer ends of the flange portions of the end plates. Therefore, when a force that deforms the flange portions of the resin portion outward in the thickness direction acts due to thermal shrinkage that occurs after molding the resin portion as described above, the folded portions can easily move in the thickness direction from the recessed grooves in the metal plate. This makes it difficult to adequately restrict deformation of the flange portions, and there is a risk of resin floating in the end plates due to thermal shrinkage.

[0006] The present invention has been made in view of the above points, and has an object to provide a stack manifold that can prevent resin floating from occurring in the end plates. [Means for solving the problem]

[0007] One aspect of the present invention is a stack manifold comprising: a first end plate, which is one of a pair of end plates sandwiching a cell stack in the thickness direction, the cell stack being formed by stacking a plurality of plate-shaped unit cells in the thickness direction; and a cylindrical piping member attached to the first end plate, wherein the piping member is made of a thermoplastic resin, and the first end plate is made of a high-strength material different from the thermoplastic resin, and the stack manifold comprises a plate main body provided with through holes penetrating the cell stack in the thickness direction and communicating with circulation holes formed as passages for fluid circulation; and a resin portion made of a thermoplastic resin and integrated with the plate main body, The resin portion has a cylindrical covering portion that covers the inner surface of the through hole in the plate body, and the covering portion has a cylindrical portion that extends in the thickness direction and is arranged so as to contact the inner surface of the through hole in the plate body, and a flange portion that is exposed outward in the thickness direction from the outer end of the plate body in the thickness direction, extends radially outward from the end of the cylindrical portion in the thickness direction, and whose outer end surface in the thickness direction is in contact with the piping member, and the plate body and the covering portion have a restricting structure that restricts the radial outer end of the flange portion from deforming outward in the thickness direction.

[0008] This configuration can prevent the resin from floating on the end plate. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view (partially exploded perspective view) of a fuel cell stack including a stack manifold according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the stack manifold of the present embodiment. [Figure 3] FIG. 3 is an enlarged view of the dashed line portion shown in FIG. [Figure 4] FIG. 4 is a front view of a first end plate of the stack manifold of the present embodiment. [Figure 5] FIG. 5 is a cross-sectional view taken along the line V-V in FIG. [Figure 6]6A is an enlarged cross-sectional view of an undercut portion of the plate body without a relief portion in the dashed line portion shown in FIG. 5 (FIG. 6A), and FIG. 6B is an enlarged cross-sectional view of the relief portion in the plate body (FIG. 6B). [Figure 7] FIG. 5 is an enlarged view of the dashed line portion shown in FIG. [Figure 8] FIG. 10 is a diagram illustrating the configuration of a cutting tool for cutting a plate body to form an undercut portion. [Figure 9] FIG. 10 is a cross-sectional view of a stack manifold according to one variant of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Specific embodiments and modifications of the stack manifold according to the present invention will be described below with reference to FIGS. 1 to 9. FIG.

[0011] The stack manifold 10 of this embodiment is a manifold applied to a fuel cell stack 1. The fuel cell stack 1 is a device that generates electricity through a chemical reaction between, for example, hydrogen and oxygen. The fuel cell stack 1 is mounted on a fuel cell vehicle (FCV). As shown in FIG. 1 , the fuel cell stack 1 includes a cell stack 20, a pair of end plates 30, 40, and a plurality of piping members 50.

[0012] The cell stack 20 is a structure in which a plurality of plate-shaped unit cells are stacked in the thickness direction. The cell stack 20 has a plurality of unit cells 21, a pair of terminal members 22, and a pair of insulating members 23.

[0013] The unit cells 21 are components that constitute the smallest unit of a battery. Each unit cell 21 is formed in a plate shape. The cell stack 20 has a structure in which a plurality of unit cells 21 are stacked in the thickness direction, and terminal members 22 are arranged adjacent to the outer sides of both thickness direction ends of the cell body, and insulating members 23 are arranged adjacent to the outer sides of both thickness direction ends of the terminal members 22. Note that the outer sides in the thickness direction refer to the sides that are separated from the cell stack 20 in the thickness direction, with the cell stack 20 as the reference.

[0014] The cell stack 20 is provided with communication holes 25. The communication holes 25 are holes formed in the cell stack 20 as passages through which fluids flow. A plurality of communication holes 25 are provided in the cell stack 20. Each communication hole 25 is drilled in each unit cell 21, terminal member 22, and insulating member 23, and extends in the thickness direction of the unit cell 21. The fluids that flow through the communication holes 25 are an anode gas (e.g., a fuel gas containing hydrogen) and a cathode gas (e.g., a fuel gas containing oxygen) used for power generation, and a cooling medium (e.g., cooling water) that cools the cell stack 20. The shape, size, and diameter of each communication hole 25 may differ for each communication hole 25, or may be determined according to the fluid that flows through them.

[0015] The flow holes 25 include a supply path for guiding anode gas into the interior, a supply path for guiding cathode gas into the interior, a supply path for guiding a cooling medium into the interior, a supply path for discharging anode gas to the outside, a supply path for discharging cathode gas to the outside, and a supply path for discharging the cooling medium to the outside.

[0016] The pair of end plates 30, 40 are members that sandwich the cell stack 20 in the thickness direction of the unit cells 21. Each end plate 30, 40 is formed in a plate shape. Each end plate 30, 40 is formed to a thickness necessary to obtain sufficient clamping force when the pair of end plates 30, 40 sandwich the cell stack 20. One end plate 30 is disposed adjacent to the front side of the unit cell 21 in the thickness direction (the front side in FIG. 1). The other end plate 40 is disposed adjacent to the rear side of the unit cell 21 in the thickness direction (the back side in FIG. 1).

[0017] Furthermore, the cell stack 20 may be clamped by the pair of end plates 30, 40 by containing the cell stack 20 and the pair of end plates 30, 40 in a storage container, or by fastening the cell stack 20 and the pair of end plates 30, 40 with fastening members.

[0018] One end plate 30 is an end plate to which a piping member 50 is attached. The other end plate 40 is an end plate to which no piping member 50 is attached. Hereinafter, one end plate 30 will be referred to as the first end plate 30, and the other end plate 40 will be referred to as the second end plate 40, as appropriate.

[0019] The second end plate 40 is made of a high-strength material. The high-strength material of the second end plate 40 is a material different from thermoplastic resin, and has higher strength than the thermoplastic resin of the piping member 50 (described later) and the resin portion 32 (described later). The high-strength material of the second end plate 40 is formed from, for example, metal such as aluminum or stainless steel, a sintered body such as ceramic, or a fiber-reinforced thermosetting resin such as CFRP.

[0020] The piping member 50 is a pipe attached to the first end plate 30. A plurality of piping members 50 are provided corresponding to the plurality of communication holes 25. The piping members 50 form a manifold. Each piping member 50 is formed in a cylindrical or rectangular tubular shape. Each piping member 50 is formed in a straight or curved shape. The piping member 50 is made of a thermoplastic resin. Examples of materials for the piping members 50 include polyphenylene sulfide (PPS), polypropylene (PP), polyamide 6T (PA6T), and polyamide 9T (PA9T).

[0021] One end of each piping member 50 is attached to the first end plate 30. The other end of each piping member 50 is connected to a gas supply source or a gas recovery unit. Anode gas, cathode gas, or a cooling medium flows through each piping member 50. The first end plate 30 and the piping members 50 are components that constitute the stack manifold 10. That is, the stack manifold 10 includes the first end plate 30 and the piping members 50.

[0022] The first end plate 30 has a plate body 31 and a resin portion 32. The plate body 31 is a plate-shaped member that forms the main body of the first end plate 30. The plate body 31 is made of a high-strength material. The high-strength material of the plate body 31 is a material different from thermoplastic resin, and has higher strength than the thermoplastic resin of the piping member 50 described above and the resin portion 32 described below. The high-strength material of the plate body 31 is formed from, for example, metal such as aluminum or stainless steel, a sintered body such as ceramic, or a fiber-reinforced thermosetting resin such as CFRP.

[0023] The plate body 31 is provided with through holes 33. The through holes 33 are holes that penetrate the plate body 31 in the thickness direction. The through holes 33 are formed to have a circular or angular cross section. A plurality of through holes 33 are provided in the plate body 31. The through holes 33 are connected to the circulation holes 25 of the cell stack 20. The through holes 33 serve as entrances and exits for the circulation holes 25 of the cell stack 20. The through holes 33 are also connected to the piping member 50. The through holes 33 connect the inside and outside of the cell stack 20, and are capable of circulating an anode gas, a cathode gas, or a cooling medium.

[0024] The resin portion 32 is a resin part that is auxiliary attached to the plate body 31. The resin portion 32 is made of a thermoplastic resin. Examples of the material of the resin portion 32 include polyphenylene sulfide (PPS), polypropylene (PP), polyamide 6T (PA6T), and polyamide 9T (PA9T). The material of the resin portion 32 may be the same as the material of the piping member 50.

[0025] The resin portion 32 is integrated with the plate body 31. The resin portion 32 is molded integrally with the plate body 31 by injecting molten resin into a mold with the plate body 31 inserted therein.

[0026] As shown in Figure 2, the resin part 32 has a covering part 34. The covering part 34 is a part that covers the inner circumferential surface of the through hole 33 in the plate body 31. Note that the resin part 32 may have a sealing part or the like in addition to the covering part 34 that covers the inner circumferential surface of the through hole 33 in the plate body 31. The covering part 34 is formed in a cylindrical or rectangular tubular shape to match the through hole 33. The covering part 34 is provided so as to extend in the thickness direction of the cell stack 20. Hereinafter, the side of the first end plate 30 that is close to the cell stack 20 in the thickness direction will be referred to as the inner side, and the side that is away from the cell stack 20 in the thickness direction will be referred to as the outer side, as appropriate.

[0027] The covering portion 34 is provided so as to be exposed on both the inner and outer sides of the through hole 33 in the thickness direction. The covering portion 34 has a cylindrical portion 34a and a flange portion 34b. The cylindrical portion 34a is a portion that extends cylindrically in the thickness direction. The cylindrical portion 34a is arranged so as to contact the inner circumferential surface of the through hole 33 in the plate body 31. A cylindrical portion 34a is provided for each through hole 33.

[0028] The flange portion 34b is a portion that extends radially outward from the end portion of the cylindrical portion 34a in the thickness direction. The radial direction refers to a direction perpendicular to the extending direction of the cylindrical portion 34a (i.e., the thickness direction of the unit cell 21). The flange portion 34b is formed in an annular shape around the through hole 33. The flange portion 34b is exposed outward in the thickness direction from the outer end of the plate body 31 in the thickness direction (specifically, from the outer opening side of the through hole 33). The flange portion 34b is provided for each through hole 33.

[0029] The plate body 31 has a recessed groove 35. The recessed groove 35 is a groove into which the flange portion 34b fits. The recessed groove 35 is continuous with the through hole 33 and spreads outward in the radial direction from the outer end portion in the thickness direction of the through hole 33. When the flange portion 34b is fitted into the recessed groove 35, the flange portion 34b is exposed to the outside in the thickness direction at the outer end surface in the thickness direction.

[0030] The piping member 50 is attached to the flange portion 34b. One end of the piping member 50 is in contact with the outer end surface of the flange portion 34b in the thickness direction. The flange portion 34b and the piping member 50 are joined to each other. This joining is performed by a method such as vibration welding, heat welding, or adhesive bonding.

[0031] As shown in Figures 2 and 3, the plate body 31 and covering portion 34 of the first end plate 30 have a restricting structure 60. The restricting structure 60 is a structure that restricts the flange portion 34b, which is exposed outward in the thickness direction from the outer end of the plate body 31 in the thickness direction, from deforming outward in the thickness direction. Specifically, the restricting structure 60 is a concave-convex structure formed on the plate body 31 and covering portion 34. The restricting structure 60 has a convex portion 61 that protrudes in the radial direction and a concave portion 62 that is recessed in the radial direction.

[0032] The protrusion 61 is provided integrally with the covering portion 34. The protrusion 61 is formed at the radially outer end of the flange portion 34b of the covering portion 34. The protrusion 61 is provided contiguous to the flange portion 34b. The protrusion 61 protrudes radially outward from a location on the radially outer end surface 34c of the flange portion 34b that is more inward in the thickness direction than the outer end in the thickness direction. In other words, the radially outer end of the flange portion 34b is formed in a stepped shape that includes a shape in which a portion with a short radial length and a portion with a long radial length are continued in that order from the outer end to the inner end in the thickness direction.

[0033] The width of the protrusion 61 in the thickness direction is set to be large enough to withstand deformation when a force that deforms the flange portion 34b outward in the thickness direction acts on the flange portion 34b during thermal contraction after molding of the resin portion 32. The protrusion 61 may protrude radially outward from a location on the radial outer end surface 34c of the flange portion 34b that is further outward in the thickness direction than the inner end in the thickness direction (see FIG. 3), or may protrude so as to be continuous with the inner end surface in the thickness direction of the flange portion 34b.

[0034] Moreover, the protrusion 61 is formed in an annular shape around the entire circumference of the through hole 33. Instead of being formed in an annular shape, the protrusion 61 may be formed at one location around the entire circumference of the through hole 33, or may be formed at two or more locations that are in an equal angular relationship around the entire circumference of the through hole 33. In this case, the circumferential width of the protrusion 61 is set to be large enough to withstand deformation when a force acts on the flange portion 34b to deform it outward in its thickness direction during thermal contraction of the resin portion 32 after molding.

[0035] As described above, the protrusions 61 and the flanges 34b are continuous with each other. Specifically, the circumferential end faces 61a of the protrusions 61 (particularly the circumferential end faces 61a of the bases of the protrusions 61) and the radially outer end faces 34c of the flanges 34b are continuous with each other. The corners where the circumferential end faces 61a of the protrusions 61 and the radially outer end faces 34c of the flanges 34b intersect are formed at obtuse angles. For example, the angle θ formed by the corners satisfies 90°<θ≦165°. This angle condition is intended to prevent stress concentration between the circumferential end faces 61a of the protrusions 61 and the radially outer end faces 34c of the flanges 34b due to thermal shrinkage of the resin portion 32 after molding.

[0036] It is more preferable that the angle θ satisfies 110°≦θ≦150°. In a structure in which the protrusion 61 is formed in an annular shape around the entire circumference of the through hole 33, the above-mentioned angle condition only needs to be applied to the angle that the thickness-direction outer end face and thickness-direction inner end face of the circumferential end face 61a of the base portion of the protrusion 61 form with the radially outer end face 34c of the flange portion 34b (see FIG. 3). On the other hand, in a structure in which the protrusion 61 is formed only on a portion of the entire circumference around the through hole 33, the above-mentioned angle condition preferably applies to the angle that the circumferential end face 61a of the base portion of the protrusion 61 forms with the radially outer end face 34c of the flange portion 34b over the entire circumference.

[0037] The recess 62 is formed in a concave shape on the plate body 31 corresponding to the protrusion 61. Specifically, the recess 62 is formed on the radially inner end surface of the plate body 31 that constitutes the recessed groove portion 35, and is recessed radially outward from a location on the radially inner end surface of the recessed groove portion 35 that is more inward than the outer end in the thickness direction. The protrusion 61 fits into the recess 62. The plate body 31 has a hook portion 36.

[0038] The hook portion 36 is a portion of the circumferential end surface 61a of the protrusion 61 that faces the outer end surface in the thickness direction when the protrusion 61 is fitted in the recess 62. The hook portion 36 is formed and positioned above the protrusion 61 when the protrusion 61 is fitted in the recess 62, and covers the protrusion 61 from above. The hook portion 36 restricts movement of the flange portion 34b by hooking onto the protrusion 61, preventing the radial outer end of the flange portion 34b from moving outward in the thickness direction.

[0039] The recess 62 is formed to a size and shape that allows the protrusion 61 to fit therein. The recess 62 is formed in a ring shape around the entire circumference of the through hole 33. Note that the recess 62 may be formed to correspond to the protrusion 61, and if the protrusion 61 is formed in a non-ring shape around the through hole 33, the recess 62 may be formed in a limited part of the entire circumference around the through hole 33 to correspond to the non-ring shape.

[0040] As shown in FIG. 6, the plate body 31 has an undercut portion 37. The undercut portion 37 is a portion that is shaded when the plate body 31 is viewed from the thickness direction, and is a portion that is cut out by cutting using a cutting tool 70 (see FIG. 8). The undercut portion 37 extends linearly as a portion where the resin portion 32 is integrated. The undercut portion 37 is formed, for example, on the inner side of the plate body 31 in the thickness direction, so as to go all the way around the outer edge of the plate body 31. The undercut portion 37 is provided to strengthen the integration between the plate body 31 and the resin portion 32 or to ensure their sealing properties.

[0041] The undercut portions 37 may be provided only partially around the entire outer edge of the plate body 31. For example, the undercut portions 37 may be provided to avoid locations such as near bolt fastening holes where the remaining thickness of the plate body 31 is small after the undercut portions 37 are formed. In this case, the undercut portions 37 may be provided in multiple separate locations.

[0042] Additionally, the corners formed at the undercut portions 37 where the plate body 31 and the resin portion 32 come into contact with each other are formed at obtuse angles. For example, the angle formed by the corners satisfies 90°<θ≦165°. This angle condition is intended to prevent stress concentration at the corners of the resin portion 32 due to thermal shrinkage of the resin portion 32 after molding. It is more preferable that the angle satisfies 110°≦θ≦150°.

[0043] The cutting tool 70 is a tool that cuts the plate body 31 to form the undercut portion 37. As shown in Fig. 8, the cutting tool 70 has a disk-shaped cutting portion 71. The cutting portion 71 cuts the plate body 31 by rotating around its axis. The cutting tool 70 is movable in a direction in which it moves toward and away from the plate body 31 (specifically, in the thickness direction of the plate body 31) during the manufacture of the plate body 31.

[0044] 6 and 7, the plate body 31 has a relief portion 38. The relief portion 38 is a space portion for inserting and removing the cutting tool 70 when forming the undercut portion 37. The relief portion 38 is provided to prevent the cutting tool 70 from interfering with a component of the plate body 31 (for example, a portion 39 of the plate body 31 that is radially opposed to the undercut portion 37, as shown in FIG. 5) when the cutting tool 70 forms the undercut portion 37 in the plate body 31.

[0045] The relief portion 38 is formed by cutting out a groove extending in the thickness direction of the plate body 31. The relief portion 38 is arranged in a position continuous with the undercut portion 37, while avoiding areas such as the vicinity of bolt fastening holes where the remaining thickness of the plate body 31 will be small after the undercut portion 37 is formed. The machining tool 70 is inserted into the relief portion 38 from the outside of the plate body 31 before the undercut portion 37 is formed, and then the machining tool 70 cuts the plate body 31 to form the undercut portion 37, and then is removed from the relief portion 38 to the outside of the plate body 31.

[0046] The relief portion 38 may be provided with a separate entrance portion for inserting the cutting tool 70 into the plate body 31 before the undercut portion 37 is formed, and an exit portion for removing the cutting tool 70 from the plate body 31 after the undercut portion 37 is formed, or they may be combined into one.

[0047] In the stack manifold 10 described above, the first end plate 30 sandwiches the cell stack 20 between itself and the second end plate 40, and has a piping member 50 attached thereto. The first end plate 30 has a plate body 31 made of a high-strength material and a resin portion 32 made of a thermoplastic resin integrated with the plate body 31. The resin portion 32 has a cylindrical covering portion 34 that covers the inner circumferential surface of a through hole 33 provided in the plate body 31 and communicating with the flow hole 25 of the cell stack 20. The covering portion 34 has a cylindrical portion 34a that contacts the inner circumferential surface of the through hole 33, and a flange portion 34b that extends radially outward from the thickness direction end of the cylindrical portion 34a, is exposed outward in the thickness direction from the outer opening side of the through hole 33 in the plate body 31, and has an outer end surface in the thickness direction with which the piping member 50 contacts. The plate body 31 and the covering portion 34 have a restricting structure 60 that restricts the radially outer end of the flange portion 34b from deforming outward in the thickness direction.

[0048] This restriction structure 60 of the first end plate 30 can restrict the radially outer end of the flange portion 34b from deforming outward in the thickness direction relative to the plate body 31 due to thermal contraction of the resin portion 32 (particularly the covering portion 34) after the plate body 31, made of a high-strength material, and the resin portion 32, made of a thermoplastic resin, are integrated. This can therefore prevent resin lift from occurring in the flange portion 34b of the first end plate 30. This can reduce deformation of the piping member 50 in contact with the flange portion 34b, preventing damage to the piping member 50 and ensuring a good seal between the piping member 50 and the first end plate 30.

[0049] The restricting structure 60 includes a protrusion 61 formed on the radially outer end surface of the flange portion 34b of the covering portion 34 of the resin portion 32, and a recess 62 formed in the plate body 31 in a concave shape corresponding to the protrusion 61. The protrusion 61 protrudes radially outward from a location on the radially outer end surface 34c of the flange portion 34b that is inward from the outer end in the thickness direction, and is covered from above by the hook portion 36 of the plate body 31. When the protrusion 61 of the flange portion 34b fits into the recess 62 of the plate body 31, the protrusion 61 is hooked onto the hook portion 36, thereby restricting the radially outer end of the flange portion 34b from moving outward in the thickness direction. Therefore, the restricting structure 60 can prevent resin floating, in which the radially outer end of the flange portion 34b deforms outward in the thickness direction from a desired position within the recessed groove portion 35 relative to the plate body 31.

[0050] Moreover, the above-described convex portion 61 and concave portion 62 are each formed in an annular shape around the entire circumference of the through-hole 33. Therefore, it is possible to restrict the radially outer end portion of the flange portion 34b from deforming outward in the thickness direction relative to the plate body 31 from a desired position within the concave groove portion 35 all around the circumference, and it is possible to reliably prevent the occurrence of resin floating all around the flange portion 34b.

[0051] Furthermore, to prevent resin floating from occurring in the flange portion 34b as described above, it is sufficient to form the convex portion 61 that protrudes radially outward on the radial outer end surface 34c of the flange portion 34b. Unlike the structure described in Patent Document 2, this configuration does not require a folded portion that extends inward in the thickness direction from the radial outer end of the flange portion 34b. Therefore, even if the first end plate 30 and thus the plate body 31 are thin, a resin floating prevention structure can be formed.

[0052] Furthermore, the angle θ formed between the circumferential end face 61a of the convex portion 61 and the radial outer end face 34c of the flange portion 34b, which are continuous with each other, satisfies 90°<θ≦165°. That is, the convex portion 61 is formed with respect to the flange portion 34b such that the circumferential end face 61a of the convex portion 61 forms an angle θ of 90°<θ≦165° with respect to the radial outer end face 34c of the flange portion 34b. This range of the angle θ makes it possible to prevent the convex portion 61 from continuing to the flange portion 34b at an acute angle θ of 90° or less.

[0053] Therefore, when a force acts on the flange portion 34b to deform it outward in the thickness direction due to thermal shrinkage of the resin portion 32 after molding, stress can be prevented from concentrating at the corner between the circumferential end face 61a of the convex portion 61 and the radial outer end face 34c of the flange portion 34b, and damage or cracks can be prevented from occurring at the base of the convex portion 61.

[0054] In the stack manifold 10, the plate body 31 of the first end plate 30, which is made of a high-strength material, is machined to have an undercut portion 37 that extends linearly as a portion to which the resin portion 32 is integrated. Furthermore, the plate body 31 has a relief portion 38 that allows a cutting tool 70 for forming the undercut portion 37 to be inserted and removed during the forming of the undercut portion 37.

[0055] According to this configuration, in a structure in which the plate body 31 has a component part that may interfere with the cutting tool 70 when the cutting tool 70 is inserted or removed to form the undercut portion 37 in the plate body 31, the cutting tool 70 can be inserted or removed from the plate body 31 while avoiding such interference, and the undercut portion 37 can be formed appropriately without causing such interference.

[0056] In the above embodiment, the convex portions 61 constituting the restriction structure 60 of the first end plate 30 are provided in the covering portion 34 of the resin portion 32, and the concave portions 62 are provided in the plate body 31. However, the present invention is not limited to this. As shown in FIG. 9 , the first end plate 30 may have a restriction structure 80 that has the convex portions 81 provided in the plate body 31 and the concave portions 82 provided in the covering portion 34 of the resin portion 32.

[0057] In the above modified embodiment, the protrusions 81 are formed on the radially inner end surface of the recessed groove 35 in the plate body 31, and protrude radially inward from a location on the radially inner end surface of the recessed groove 35 that is outer than the inner end in the thickness direction. The recesses 82 are formed in a concave shape in the covering portion 34 corresponding to the protrusions 81. Specifically, the recesses 82 are formed on the radially outer end surface 34c of the flange portion 34b in the covering portion 34, and are recessed radially inward from a location on the radially outer end surface 34c of the flange portion 34b that is outer than the inner end in the thickness direction. The protrusions 81 fit into the recesses 82.

[0058] In this modified embodiment, when the convex portion 81 of the plate body 31 fits into the concave portion 82 of the covering portion 34, a portion of the radially outer end of the flange portion 34b of the covering portion 34 that is more inward in the thickness direction than the convex portion 81 gets caught on the convex portion 81, thereby restricting the inner portion of the flange portion 34b from moving outward in the thickness direction. Therefore, the restricting structure 80 can suppress deformation of the flange portion 34b outward in the thickness direction relative to the plate body 31, and can prevent resin floating from occurring.

[0059] The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention, including implementing the invention by appropriately extracting and combining elements described in the embodiments. Furthermore, the specification of the present invention discloses not only the citation relationships of each claim as originally filed, but also the technical idea of ​​appropriately combining the matters described in each claim. [Explanation of symbols]

[0060] 1: fuel cell stack, 10: stack manifold, 20: cell stack, 21: single cell, 25: flow hole, 30: first end plate, 31: plate body, 32: resin portion, 33: through hole, 34: covering portion, 34a: cylindrical portion, 34b: flange portion, 34c: radial outer end surface, 35: groove portion, 36: hook portion, 37: undercut portion, 38: relief portion, 40: second end plate, 50: piping member, 60, 80: restriction structure, 61, 81: convex portion, 61a: circumferential end surface, 62, 82: concave portion.

Claims

1. a first end plate that is one of a pair of end plates that sandwich a cell stack in the thickness direction, the cell stack being formed by stacking a plurality of plate-shaped unit cells in the thickness direction; a cylindrical piping member attached to the first end plate; A stack manifold comprising: the piping member is made of a thermoplastic resin, The first end plate is a plate body made of a high-strength material different from thermoplastic resin, the plate body having through holes penetrating the cell stack in the thickness direction and communicating with circulation holes formed in the cell stack as passages through which fluid flows; a resin portion made of a thermoplastic resin and integrated with the plate body; and the resin portion has a cylindrical covering portion that covers an inner circumferential surface of the through hole in the plate body, The covering portion is a cylindrical portion extending in the thickness direction and arranged to contact an inner circumferential surface of the through hole in the plate body; a flange portion that is exposed to the outside in the thickness direction from an outer end of the plate body in the thickness direction, extends radially outward from an end of the cylindrical portion in the thickness direction, and has an outer end surface in the thickness direction that contacts the piping member; and The plate body and the covering portion have a restricting structure that restricts radially outer ends of the flange portions from deforming outward in the thickness direction.

2. The regulatory structure includes: a protrusion formed on a radially outer end surface of the flange portion of the covering portion, the protrusion protruding radially outward from a location on the radially outer end surface of the flange portion that is more inward than an outer end in the thickness direction; a recess formed in the plate body in a recessed shape corresponding to the protrusion; The stack manifold of claim 1 , comprising:

3. The stack manifold according to claim 2 , wherein the protrusion and the recess are each formed in an annular shape around the entire circumference of the through hole.

4. 4. The stack manifold according to claim 2, wherein an angle θ formed between a circumferential end surface of the convex portion and a radially outer end surface of the flange portion, the angle θ being in the range of 90°<θ≦165°.

5. The plate body is an undercut portion that is machined and extends linearly as a portion where the resin portion is integrated; a relief portion for allowing a cutting tool for forming the undercut portion by cutting to be inserted and removed when the undercut portion is formed; The stack manifold of claim 1 , comprising:

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