JP2007172874A - Fuel cell separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separator capable of freely changing a passage shape without increasing pitches of a fuel cell unit cell. <P>SOLUTION: The separator 20 used in a fuel cell generating electric power with gases for power generation is equipped with a first passage 21 on the surface formed by press work of the central part of a separator body; a second passage 22 on the back; a first passage rib 101 arranged at both ends on the surface of the separator body, stringing out along the first passage 21, and straightening gas for power generation; and a second passage rib 103 arranged at both ends of the back of the separator body, stringing out along the second passage 22, and straightening gas for power generation or a cooling medium, and the first passage rib 101 and the second passage rib 103 are independently formed with material different from the separator body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell separator.

  A polymer electrolyte fuel cell stack (hereinafter referred to as “fuel cell stack”) is formed by laminating a single cell comprising a membrane electrode assembly (hereinafter referred to as “MEA”) and a pair of separators having flow paths on both sides. Consists of. The MEA is composed of an anode electrode formed on one surface of the electrolyte membrane and a cathode electrode formed on the other surface.

An anode gas containing hydrogen H ₂ flows through the flow path of the separator in contact with the anode electrode.

This causes the following reaction at the anode electrode.
Anode electrode: 2H ₂ → 4H ⁺ + 4e ⁻ (1)
The proton H ⁺ thus generated at the anode electrode passes through the electrolyte membrane and reaches the cathode electrode. Further, the electron e ⁻ reaches the cathode electrode through an external circuit.

A cathode gas containing oxygen O ₂ flows through the flow path of the separator in contact with the cathode electrode.

This cathode gas reacts with protons H ⁺ and electrons e ⁻ that have reached the cathode electrode. This causes the following reaction at the cathode electrode.
Cathode electrode: O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (2)
Between each single cell, a cooling water flow path is formed by the flow path on the back surface of the adjacent separator. The cooling water flowing through this cooling water flow path absorbs heat generated by the single cell.

  Now, as a role of the separator, it is necessary to separate each single cell of the fuel cell stack and distribute each gas to each electrode. Further, in order to stack the fuel cell stack and function as a battery, the separator needs to be a conductor. Further, the separator needs to be thin in order to improve the space efficiency of the fuel cell stack.

For this reason, a conventional fuel cell separator is manufactured by pressing a metal thin plate, and the above-described flow paths are formed on both surfaces (see Patent Document 1).
JP-A-11-354142

  However, if the flow paths on both sides of the separator are formed by pressing from a thin metal plate, the shape of the flow path on one side that guides the gas is affected by the shape of the flow path on the other side that guides the cooling medium. become. For this reason, restrictions have been imposed on the shape of the flow path, and there has been a risk of non-uniform distribution of each gas in the conventional separator. On the other hand, in order to eliminate this non-uniform distribution of gas, only the flow path near the center is formed by pressing, and the other flow paths are attached by separate parts manufactured by pressing. It was molded. However, in this case, there is a possibility that the flow rate of the gas or the cooling medium cannot be sufficiently secured due to the plate thickness of the separate component itself. And if it is going to ensure this flow enough, there existed a possibility that the problem that the cell pitch of a single cell had to be increased by the plate | board thickness of another component itself might arise.

  The present invention has been made paying attention to such a conventional problem, and without causing an increase in the cell pitch of a single cell, the flow channel shape other than the vicinity of the center of the separator can be freely changed, thereby It aims at providing the fuel cell separator which can perform distribution appropriately.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.

  In a separator used in a fuel cell that generates electricity by supplying a gas for power generation to a membrane electrode assembly, the separator main body is formed by pressing a separator main body composed of a conductive member and a central portion of the separator main body. A groove-shaped first flow path that leads to the power generation gas, and is formed in parallel with a flow path that is formed on the back surface of the separator body by the pressing process and that guides the power generation gas. A groove-shaped second flow path for guiding a working gas or a cooling medium, and a first flow path arranged at at least one end of the surface of the separator body and connected to the first flow path to rectify the power generation gas. And a second flow channel rib arranged at at least one end of the back surface of the separator body and connected to the second flow channel to rectify the power generation gas or the cooling medium. For example, wherein the first flow path the ribs and the second flow path the ribs provides a fuel cell separator, characterized by being formed independently with different materials, and each other with the separator body.

  According to the present invention, since the flow passages connected to the flow passage in the central portion of the separator main body are formed by the flow passage ribs independent of each other, the flow passage ribs by press working as in the past, depending on the plate thickness. There is no problem that a sufficient flow rate cannot be secured. Therefore, it is possible to provide a separator that can rectify the fluid without increasing the cell pitch in order to ensure a sufficient flow rate.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
(First embodiment)
FIG. 1 is a perspective view of a fuel cell stack 10 using the fuel cell separator of the present invention. The fuel cell stack 10 is a fuel cell stack used for a moving vehicle such as an automobile.

  The fuel cell stack 10 includes a plurality of stacked single cells 1, a pair of current collector plates 2, a pair of insulators 3, a pair of end plates 4, and nuts 5.

  The single cell 1 is a unit cell of a polymer electrolyte fuel cell that generates an electromotive force. Each single cell 1 generates an electromotive voltage of about 1 volt (V). Details of the configuration of each single cell 1 will be described later.

The pair of current collector plates 2 are respectively arranged outside the plurality of stacked unit cells 1. The current collector plate 2 is formed of a gas impermeable conductive member, and is formed of dense carbon, for example. The current collector plate 2 includes an output terminal 2a at a part of the upper side. The fuel cell stack 1 takes out and outputs the electrons e ⁻ generated in each single cell 1 through the output terminal 2a.

  The pair of insulating plates 3 are respectively arranged outside the current collector plate 2. The insulating plate 3 is formed of an insulating member, and is formed of, for example, rubber.

  The pair of end plates 4 are respectively arranged outside the insulating plate 3. The end plate 4 is formed of a metallic material having rigidity, for example, steel.

  Of the pair of end plates 4, one end plate 4 (the front end plate 4 in FIG. 1) includes a cooling water inlet hole 41a, a cooling water outlet hole 41b, and an anode gas (power generation gas) inlet hole 42a. An anode gas outlet hole 42b, a cathode gas (power generation gas) inlet hole 43a, and a cathode gas outlet hole 43b.

  The end plate 4 has a cooling water inlet hole 41a, an anode gas outlet hole 42b, and a cathode gas inlet hole 43a on the same end side. The end plate 4 has a cooling water outlet hole 41b, an anode gas inlet hole 42a, and a cathode gas outlet hole 43b on the same end side.

  The four nuts 5 are respectively arranged outside the pair of end plates 4. The four nuts 5 are respectively arranged near the four corners of the end plate 4. By the way, the fuel cell stack 1 has a through hole (not shown) penetrating therein. A tension rod (not shown) is inserted through the through hole. The tension rod is formed of a metal material having rigidity, for example, steel. In order to prevent an electrical short circuit between the single cells 1, the surface of the tension rod is subjected to insulation treatment. Nuts 50 are screwed onto both ends of the tension rod. The nut 50 and the tension rod tighten the fuel cell stack 1 in the stacking direction.

  FIG. 2 is a diagram showing a part of a side cross section of a single cell 1 using a separator according to the present invention. In this figure, the uneven flow path at the center of the separator and the MEA 11 sandwiched between the flow paths are shown.

  The single cell 1 includes an MEA 11, a separator 20, a separator 30, and a gasket 12. The single cell 1 has a separator 20 on one side of the MEA 11. The single cell 1 has a separator 30 on the other side of the MEA 11.

  The MEA 11 includes an electrolyte membrane 11a, an anode electrode 11b, and a cathode electrode 11c. The MEA 11 has an anode electrode 11b on one surface of the electrolyte membrane 11a and a cathode electrode 11c on the other surface.

  The electrolyte membrane 11a is a proton-conductive ion exchange membrane formed of a fluorine-based resin. The electrolyte membrane 11a exhibits good electrical conductivity in a wet state.

  The anode electrode 11b includes a gas diffusion layer, a water repellent layer, and a catalyst layer.

  The gas diffusion layer is formed of a member having sufficient gas diffusibility and conductivity, and is formed of, for example, a carbon cloth woven with yarns made of carbon fibers. The water repellent layer is a layer containing polyethylene fluoroethylene and a carbon material. The catalyst layer is formed from carbon black particles on which platinum is supported.

  Since the cathode electrode 11c is configured similarly to the anode electrode 11b, a detailed description thereof is omitted.

  The separator 20 is in contact with the anode electrode 11b. The separator 20 is manufactured by a thin metal plate having sufficient conductivity, strength, and corrosion resistance.

  The separator 20 has a gas flow path 21 on one surface. The gas flow path 21 is in contact with the anode electrode 11b.

  The separator 20 has a cooling water passage 22 on the other surface. The cooling water channel 22 is continuous with a cooling water channel 32 described later of the adjacent separator 30.

  The separator 30 is in contact with the cathode electrode 11c. Since the separator 30 has substantially the same configuration as the separator 20, a detailed description thereof is omitted. The separator 30 has a gas flow path 31 on one surface. The gas flow path 32 is in contact with the cathode electrode 11c. The separator 30 has a cooling water channel 32 on the other surface.

  The gasket 12 (seal part) is formed of a rubber-like elastic material, for example, silicon rubber.

  The gasket 12 serves to seal the gas flowing through the gas flow paths 21 and 31 and the cooling water flowing through the cooling water flow paths 22 and 32. Details of the gasket 12 will be described below.

  Hereinafter, the power generation reaction in the single cell 1 will be described. The anode gas flows from the anode gas inlet hole 42 a (FIG. 1) into the fuel cell stack 10 and flows through the gas flow path 21. The anode gas contacts the anode electrode 11 b while flowing through the gas flow path 21. As a result, the reaction of the above formula (1) occurs on the anode electrode 11b. Excess anode gas that has passed through the gas flow path 21 and was not used for the reaction is discharged to the outside from the anode gas outlet hole 42b (FIG. 1).

On the other hand, the cathode gas flows from the cathode gas inlet hole 43 a (FIG. 1) into the fuel cell stack 10 and flows through the gas flow path 31. The cathode gas is in contact with the cathode electrode 11 c while flowing through the gas flow path 31. On the cathode electrode 11c, the reaction of the formula (2) occurs from the cathode gas and the protons H ⁺ and electrons e ⁻ generated by the reaction of the formula (1). Excess cathode gas that has passed through the gas flow path 31 and was not used for the reaction is discharged to the outside from the cathode gas outlet hole 42b.

  Next, the action of the cooling water in the single cell 1 will be described.

  The cooling water flows from the cooling water inlet hole 41 a (FIG. 1) into the fuel cell stack 10 and flows through the flow path formed by the cooling water flow paths 22 and 32. The cooling water absorbs heat from the separator 20 and the separator 30 while flowing through the flow path formed by the cooling water flow paths 22 and 32. The cooling water that has absorbed heat in this way is discharged to the outside from the cooling water outlet hole 41b.

  FIG. 3 is a diagram showing a first embodiment of a separator according to the present invention.

  FIG. 3A is a diagram showing the separator 20 of the present embodiment as viewed from the MEA 11 side. A dotted line in the drawing is a dotted line showing a surface of the separator 20 on the side opposite to the MEA 11 side. FIG. 3B is a diagram showing a BB cross section of FIG. FIG. 3C is a view showing the channel ribs 101 to 104 arranged on the separator 20.

  The separator 20 has a plurality of groove-shaped gas flow paths 21 (first flow paths) on the front surface and a plurality of groove-shaped cooling water flow paths 22 (second flow paths) on the back surface in the central portion. . The gas channel 21 and the cooling water channel 22 are formed by pressing the separator 20 (separator body). The gas flow path 21 and the cooling water flow path 22 each extend linearly in parallel with the longitudinal direction of the separator 20. The back surface between the gas flow paths 21 is a cooling water flow path 22.

  The separator 20 has an anode gas outlet hole 21b (first outlet hole), a cooling water inlet hole 22a (second inlet hole), and a cathode gas inlet hole 23a at the left end. Each hole is formed through. The anode gas outlet hole 21 b is disposed on the left end of the separator 20. The cooling water inlet hole 22 a is disposed at the center of the left end of the separator 20. The cathode gas inlet hole 23a is disposed below the left end of the separator 20 (FIG. 3A).

  The separator 20 has an anode gas inlet hole 21a (first inlet hole), a cooling water outlet hole 22b (second outlet hole), and a cathode gas outlet hole 23b at the right end. Each hole is formed through. The cathode gas outlet hole 23 b is disposed on the right end of the separator 20. The cooling water outlet hole 22 b is disposed at the center of the right end of the separator 20. The anode gas inlet hole 21 a is disposed below the right end of the separator 20.

  Here, the anode gas inlet hole 21a, the anode gas outlet hole 21b, the cathode gas inlet hole 23a, and the cathode gas outlet hole 23b have substantially the same shape. Further, the cooling water inlet hole 22a and the cooling water outlet hole 22b have substantially the same shape.

  The separator 20 includes the gasket 12 described above so as to surround the cooling water inlet hole 22a, the cooling water outlet hole 22b, the cathode gas inlet hole 23a, and the cathode gas outlet hole 23b on the surface. And the separator 20 is equipped with the gasket 12 so that the anode gas inlet hole 21a and the anode gas outlet hole 21b may be continued on the surface. Thus, only the anode gas flows on the surface of the separator 20, and the cooling water and the cathode gas do not flow.

  In order to facilitate understanding of the present invention, the region in which the above-described anode gas circulates will be described below as an anode gas flow channel region 24a.

  The anode gas channel region 24a extends from the anode gas inlet hole 21a toward the left so as to have a width substantially the same as the width of the separator 20. The anode gas flow channel region 24a is narrowed toward the anode gas outlet hole 21b.

  The anode gas channel region 24a includes an inlet side channel region 25a and an outlet side channel region 26a. The inlet-side flow channel region 25 a is a region that extends from the anode gas inlet hole 21 a toward the gas flow channel 21. The outlet side flow channel region 26a is a region that is recessed from the gas flow channel 21 toward the anode gas outlet hole 21b.

  The separator 20 has a plurality of channel ribs 101 (first channel ribs) in the inlet-side channel region 25a. The channel rib 101 rectifies the anode gas from the anode gas inlet hole 21 a toward the gas channel 21. Specifically, the flow path rib 101 rectifies the anode gas so as to spread across the width of the separator 20 from the lower right end of the separator 20.

  Four channel ribs 101 are formed on the anode gas inlet hole 21a side and four on the gas channel 21 side. The channel rib 101 has a shape elongated in the longitudinal direction of the separator 20. The flow path ribs 101 are arranged radially so that the interval between the flow path ribs 101 extends from the anode gas inlet hole 21 a toward the gas flow path 21. The width of each flow channel rib 101 is narrower than the width of the gas flow channel 21. Each flow path rib 101 is substantially the same height as the gasket 12 (FIG. 3B). With the above configuration, the channel rib 101 smoothly diffuses the anode gas from the anode gas inlet hole 21 a to the gas channel 21.

  The separator 20 has a plurality of flow channel ribs 102 in the outlet side flow channel region 26a. The channel ribs 102 rectify the anode gas from the gas channel 21 toward the anode gas outlet hole 21b. Specifically, the flow path rib 102 rectifies the anode gas so as to collect from the full width of the separator 20 to the left end of the separator 20.

  The flow path ribs 102 are arranged in a radial pattern that extends from the anode gas outlet hole 21 b toward the gas flow path 21 in substantially the same manner as the flow path rib 101. Since the channel ribs 102 have substantially the same shape as the channel ribs 101, detailed description thereof is omitted. With the above configuration, the channel rib 102 smoothly collects the anode gas from the gas channel 21 to the anode gas outlet hole 21b.

  The separator 20 includes the gasket 12 described above so as to surround the anode gas inlet hole 21a, the anode gas outlet hole 21b, the cathode gas inlet hole 23a, and the cathode gas outlet hole 23b on the back surface. And the separator 20 is equipped with the gasket 12 so that the cooling water inlet hole 22a and the cooling water outlet hole 22b may be continued in a back surface (FIG. 3 (A) dotted line). As a result, only the cooling water flows on the back surface of the separator 20, and the anode gas and the cathode gas do not flow. Here, the height of the gasket 12 on the back surface of the separator 20 is substantially equal to the height of the gasket 12 on the front surface.

  In order to facilitate understanding of the present invention, the above-described region through which the cooling water flows will be described below as a cooling water flow channel region 24b.

  The cooling water flow path region 24 b has a shape substantially equivalent to the anode gas flow path region 24 a at the center of the separator 20, but has different shapes at both ends of the separator 20.

  The cooling water channel region 24b includes an inlet side channel region 26b and an outlet side channel region 25b. The inlet side channel region 26b is disposed on the back surface of the outlet side channel region 26a. The outlet side channel region 25b is disposed on the back surface of the inlet side channel region 25a.

  The inlet-side flow channel region 26b is a region that extends from the cooling water inlet hole 22a toward the cooling water flow channel 22. Channel ribs 104 are arranged in the inlet side channel region 26b. The channel rib 104 has substantially the same shape as the channel ribs 101 and 102. The flow path ribs 104 are arranged radially so as to spread from the cooling water inlet hole 22 a toward the cooling water flow path 22 in the same manner as the flow path ribs 101 and 102. Here, the flow path ribs 102 are arranged radially from the upper left end of the separator 20, whereas the flow path ribs 104 on the rear surface are arranged radially from the left end center. For this reason, the channel ribs 102 and the channel ribs 104 are not arranged in parallel across the separator 20 (solid line and dotted line in FIG. 3A).

  The outlet side channel region 25b is a region that is recessed from the cooling water channel 22 toward the cooling water outlet hole 22b. A channel rib 103 (second channel rib) is disposed in the outlet side channel region 25b. The channel rib 103 has substantially the same shape as the channel ribs 101 and 102. Since the flow path rib 103 is disposed substantially the same as the flow path rib 104, detailed description thereof is omitted. Here, similarly to the relationship between the channel ribs 102 and the channel ribs 104, the channel ribs 103 and the channel ribs 101 are not arranged in parallel with the separator 20 in between (the solid line in FIG. dotted line).

  The flow channel ribs 101 to 104 are separate members from the separator 20, and the mold is used as described later for the inlet side flow channel region 25 a, the outlet side flow channel region 26 a, the inlet side flow channel region 26 b, and the outlet side flow channel. It is placed directly on the region 25b, and rubber is injected to integrally form it. The channel ribs 101 to 104 are formed so as to stand vertically with respect to the separator 20 (FIG. 3C).

  Since the separator 30 has substantially the same configuration as the separator 20, detailed description thereof is omitted.

  FIG. 6 is a diagram relating to a conventional separator used in a fuel cell. FIG. 6A is a diagram illustrating a part of the surface of the separator 60 on the MEA 11 side. The arrows in the figure are arrows indicating the flow of anode gas. FIG. 6B is a view showing a cross section when the separator 60 is cut along BB.

  The conventional flow path rib 600 is different from the flow path ribs 101 to 104 of the present invention formed by injection molding in that it is formed by press working.

  The channel rib 600 is manufactured by press work separately from the manufacture of the separator 60 and is attached to the outlet side channel region 26a (FIG. 6B).

  In the flow path rib 600, the flow rate of the anode gas flowing between the convex portions cannot be sufficiently ensured due to the plate thickness. Further, if the flow rate is to be secured sufficiently, the convex portion has to be made higher by that amount, and there is a problem that the cell pitch must be increased by the flow path rib 600.

  In the present invention, since the flow channel ribs 100 to 104 are formed as described above with respect to such a flow channel rib 600, the conventional problems can be solved as follows.

  The separators 20 and 30 are preferably manufactured as a whole by pressing a metal thin plate from the above-described role, necessity, and productivity. Here, the anode gas inlet hole 21a, the anode gas outlet hole 21b, the cooling water inlet hole 22a, the cooling water outlet hole 22b, the cathode gas inlet hole 23a, the cathode gas outlet hole 23b, and the flow paths at the center of both surfaces are separators. Since it is common to 20 and 30, it can form by press work.

  However, as described above, in the inlet-side channel region 25a of the separator 20 and the outlet-side channel region 25b on the back surface thereof, the movement trajectory of the fluid flowing through each region is not parallel. Similarly, the movement trajectory of the fluid flowing through each region is not parallel in the outlet side channel region 26a and the inlet side channel region 26b on the back surface thereof. For these reasons, unlike the flow paths formed on both surfaces of the central portion of the separator 20, it is not appropriate to form the flow paths at both ends of the separator 20 by pressing.

  Therefore, in the present invention, as described above, the fluid in these regions is rectified by the channel ribs 101 to 104 that are not press-worked. In the present invention, the channel ribs 101 to 104 are formed separately from the separator 20 and injection molded so as to be integrally formed with the separator 20. When injection molding is performed in this manner, the channel ribs 101 to 104 stand vertically from the separator 20. Therefore, the flow ribs 101 to 104 do not have a problem that the flow rate cannot be sufficiently secured due to the plate thickness as in the conventional flow rib 600. Therefore, in the channel ribs 101 to 104, there is no problem that the pitch of the single cell 1 has to be increased in order to ensure a sufficient flow rate.

  In addition, the channel rib 101 is formed in the inlet-side channel region 25a, and the channel rib 103 is formed separately from the channel rib 101 in the outlet-side channel region 25b on the back surface thereof. Therefore, in the inlet side channel region 25a and the outlet side channel region 25b, the channel rib 101 and the channel rib 103 can be formed as much as necessary. The same applies to the outlet side channel region 26a and the inlet side channel region 26b. Therefore, the arrangement of the channel ribs in each region can be kept to the minimum necessary, and the manufacture of the separator 20 can be simplified.

  The separator 30 is configured substantially the same as the separator 20 as described above. The separator 30 has an anode gas outlet hole 21b at the left end of the separator 20, a cooling water inlet hole 22a, and a cathode gas inlet hole 23a at the right end. The separator 30 has an anode gas inlet hole 21a at the right end of the separator 20, a cooling water outlet hole 22b, and a cathode gas outlet hole 23b at the left end. In addition, the gasket 12 is provided substantially in the same manner as the separator 20, and only the cathode gas is circulated on the front surface and the cooling water is circulated on the back surface.

  Here, the anode gas inlet hole 21a, the anode gas outlet hole 21b, the cathode gas inlet hole 23a, and the cathode gas outlet hole 23b have substantially the same shape. Further, the cooling water inlet hole 22a and the cooling water outlet hole 22b have substantially the same shape.

  Therefore, the separator 20 and the separator 30 have the same shape, and in the present invention, the separators 20 and 30 can be shared.

  Further, since the mold is placed directly on the separator 20 and rubber is injected to form the channel ribs 101 to 104, it is not necessary to stick the separator rib 20 after the channel ribs 101 to 104 are manufactured. Therefore, the manufacturing process can be reduced.

(Second Embodiment)
FIG. 4 is a view showing a second embodiment of the separator according to the present invention. In the following embodiments, the same reference numerals are given to the portions that perform the same functions as those of the above-described embodiments, and overlapping descriptions are omitted as appropriate.

  FIG. 4A is a diagram illustrating the surface of the separator 20. In addition, the dotted line of the round frame in a figure is a dotted line which shows the through hole H. FIG. FIG. 4B is a view showing a cross section when the separator 20 is cut along BB. FIG. 4C is a diagram illustrating a method for manufacturing the flow path ribs 101 and 103.

  The separator 20 has a through-hole H at the intersection of the flow channel rib 101 and the flow channel rib 103 disposed on the back surface thereof (FIG. 4 (A) dotted circle). The through hole H penetrates the separator 20, and the flow channel rib 101 and the flow channel rib 103 are continuous through the through hole H (FIG. 4B).

  The same applies to the channel ribs 102 and the channel ribs 104 disposed on the back surface thereof, and detailed description thereof will be omitted.

  A method for manufacturing the flow path ribs 101 and 103 of this embodiment will be described.

  A through hole H is formed at the intersection of the flow channel rib 101 and the flow channel rib 103 on the surface of the separator 20 (through hole forming step).

  In the next step, a mold 71 (first mold) having an injection port 71a and a mold 72 (second mold) having no injection port are arranged so as to cover the through hole H (metal mold). Mold placement step). In the present embodiment, the mold 71 is disposed so as to form the flow path rib 101. The mold 72 is disposed so as to form the flow path rib 103. Here, the shape of the space surrounded by the inner wall of the mold 71 and the separator 20 is substantially the same as the shape of the flow path rib 103. The shape of the space surrounded by the inner wall of the mold 72 and the separator 20 is substantially the same as the shape of the flow path rib 103.

  In the next step, rubber is injected from the injection port 71a into the space surrounded by the inner walls of the molds 71 and 72 (injection step).

  In the next step, the injected rubber is cured as described above (curing step).

  As described above, the molds 71 and 72 are removed from the separator 20 after the rubber is cured. The channel rib 101 and the channel rib 103 formed in this way are the channel ribs 101 and 103 shown in FIG.

  Since the flow channel ribs 102 and the flow channel ribs 104 are formed in the same manner, detailed description thereof is omitted.

  In this embodiment, since the through hole H is provided in the separator 20, the flow path ribs 101 to 104 on both sides can be simultaneously formed by injecting rubber from one side of the separator. Therefore, the manufacturing process can be further simplified compared to the first embodiment in which rubber is injected from both sides of the separator 20 to form the channel ribs 101-104.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

  FIG. 5 is a view showing a cross section of the fuel cell stack 10 using the separator of the present invention.

  The fuel cell stack 10 includes a second end plate 4A between one end plate 4 and the insulating plate 3 (right side in FIG. 5), and a spring or the like between the end plate 4 and the second end plate 4A. A pressurizing device 6 may be provided. In this case, the fuel cell stack 10 can be tightened more strongly between the pair of end plates 4 by the tension rod 5.

  In addition, the fuel cell stack 10 may be configured such that the pair of end plates 4 are tightened with the tension rods outside rather than being tightened with the tension rods inserted through the inside.

  The fuel cell stack 10 may be used other than an automobile.

  The current collector plate 2 may be formed of a copper plate or the like as long as it is a gas impermeable conductive member.

  The insulating plate 3 may be formed of resin or the like as long as it is an insulating member.

  The end plate 4 and the second end plate 4A may be formed of a member other than a metal material such as steel as long as the material has rigidity.

  The tension rod 5 may be formed of a member other than a metal material such as steel as long as the material has rigidity.

  The electrolyte membrane 11a may be a proton-conductive ion exchange membrane that exhibits good electrical conductivity in a wet state, and may be formed of a solid polymer material other than a fluorine-based resin.

  The gas diffusion layer forming the anode electrode 11b and the cathode electrode 11c is not limited to carbon cloth as long as it is a member having sufficient gas diffusibility and conductivity, and may be composed of carbon paper, carbon felt, or the like.

  The catalyst layer forming the anode electrode 11b and the cathode electrode 11c is not necessarily supported by the gas diffusion layer to form an electrode, but platinum or an alloy of platinum and other metals as a catalyst is supported on the surface of the electrolyte membrane 11a. May be. In this case, the anode electrode 11b and the cathode electrode 11c are formed of a gas diffusion layer assembly in which a water repellent layer is laminated on the surface of the gas diffusion layer.

  Separator 20,30 should just be formed with the material which has sufficient electroconductivity, intensity | strength, and corrosion resistance, and may be manufactured by pressing a carbon material.

  The gasket 12 may be formed of a rubber-like elastic material such as EPDM or fluororubber. The gasket 12 may be integrated with the separators 20 and 30 or a separator formed of a thin plate material having a large elastic coefficient. The thin plate material having a large elastic modulus is formed of a material such as polycarbonate or polyethylene terephthalate, and is bonded to the electrolyte membrane 11a by a liquid seal such as thermosetting fluorine-based or thermosetting silicon.

  The channel ribs 101 to 104 may be integrally formed by injection molding resin, elastomer or the like.

  You may arrange | position the flow-path ribs 101-104 and the gasket 12 simultaneously at the same process. The manufacturing process of the separator 20 in this case will be described.

In the separator 20, an anode gas inlet hole 21a, an anode gas outlet hole 21b, a cooling water inlet hole 22a, a cooling water outlet hole 22b, a cathode gas inlet hole 23a, and a cathode gas are formed by pressing a metal thin plate. Forming the outlet hole 23b (hole forming step);
The gas flow path 21 and the cooling water flow path 22 are formed (flow path forming step).

  Next, the gasket 12 that seals the anode gas, the cathode gas, and the cooling water flowing through the front and back surfaces of the separator 20 and the flow path ribs 101 to 104 are simultaneously disposed by the injection molding (injection process).

  Since the separator 30 is manufactured substantially the same as the separator 20, detailed description is omitted.

  In this invention, the manufacturing process of the separators 20 and 30 can be reduced by arrange | positioning the gasket 12 and the flow-path ribs 101-104 simultaneously by the equivalent process in this way.

  The members of the channel ribs 101 to 104 may have higher hardness than the members of the gasket 12.

  The single cell 1 is strongly tightened in the stacking direction, and the gasket 12 may be deformed by this force. However, as described above, if the flow path ribs 101 to 104 are formed of a member having a hardness higher than that of the gasket 12, the deformation of the gasket 12 can be suppressed by the flow path ribs 101 to 104. Therefore, in this case, the sealing performance is prevented from being lowered due to the deformation of the gasket 12.

It is a figure which shows the fuel cell stack using the separator by this invention. It is a figure which shows a part of side cross section of the single cell using the separator by this invention. It is a figure regarding the separator of 1st Embodiment of this invention. It is a figure regarding the separator of 2nd Embodiment of this invention. It is a figure which shows the fuel cell stack using the separator of this invention. It is a figure explaining the conventional separator for fuel cells.

Explanation of symbols

1 Single cell 2 Current collector plate 3 Insulating plate 4, 4A End plate 12 Gasket (seal part)
20, 30 Separator 21, 31 Gas channel 22, 32 Cooling water channel 25a, 26b Inlet side channel region 25b, 26a Outlet side channel region 101, 102, 103, 104 Channel rib H Through hole

Claims (12)

In a separator used in a fuel cell that generates electricity by supplying a gas for power generation to a membrane electrode assembly,
A separator body composed of a conductive member;
By pressing the central portion of the separator body, a groove-shaped first flow path that is formed on the surface of the separator body and guides the power generation gas;
A groove-shaped second flow path formed on the back surface of the separator main body by the pressing process, in parallel with the first flow path, for guiding the power generation gas or the cooling medium;
A first flow path rib disposed at at least one end of the surface of the separator body, connected to the first flow path, and rectifying the power generation gas;
A second channel rib disposed at at least one end of the back surface of the separator body, connected to the second channel, and rectifies the power generation gas or the cooling medium;
With
The fuel cell separator, wherein the first flow path rib and the second flow path rib are made of a material different from that of the separator body and are independent from each other. The fuel cell separator according to claim 1, wherein
A first inlet hole formed through the separator body and supplying the power generation gas to the first flow path;
A second inlet hole formed through the separator body and supplying the power generation gas or the cooling medium to the second flow path;
A first outlet hole formed through the separator body and discharging the power generation gas from the first flow path;
A second outlet hole formed through the separator body and discharging the power generation gas or the cooling medium from the second flow path;
A fuel cell separator comprising: The fuel cell separator according to claim 1 or 2,
The separator body is a metal plate;
A fuel cell separator. The fuel cell separator according to any one of claims 1 to 3, wherein
The first channel rib and the second channel rib are integrally formed by injection molding an elastic member on the separator body.
A fuel cell separator. In the fuel cell separator according to any one of claims 1 to 4,
The first channel rib and the second channel rib are formed of rubber.
A fuel cell separator. In the fuel cell separator according to any one of claims 1 to 4,
The first flow path rib and the second flow path rib are formed of resin.
A fuel cell separator. The fuel cell separator according to any one of claims 1 to 6, wherein
A rib-shaped seal portion that is disposed on the separator body and seals the power generation gas or the cooling medium;
The hardness of the first channel rib and the second channel rib is higher than the hardness of the seal part,
A fuel cell separator. The fuel cell separator according to any one of claims 1 to 7, wherein
An intersection of the first flow path rib and the second flow path rib, and having a through hole penetrating the separator body,
The first flow path rib and the second flow path rib are continuous through the through hole.
A fuel cell separator.   A fuel cell stack comprising the fuel cell separator according to any one of claims 1 to 8. A method for producing a separator used in a fuel cell that generates power by supplying a gas for power generation to a membrane electrode assembly,
By pressing the central portion of the separator body, the groove-shaped first flow path for guiding the power generation gas on the surface of the separator body and the power generation gas or the cooling medium on the back surface of the separator body are guided. A flow path forming step for forming a groove-shaped second flow path;
An elastic member includes a rib-shaped seal portion that seals the power generation gas and the cooling medium, and a flow path rib that is disposed at both ends of the separator body and that is connected to the flow path and rectifies the power generation gas or the cooling medium. An injection process of integrally molding by injection molding,
A separator manufacturing method comprising: It is a manufacturing method of the separator according to claim 10,
A first inlet hole for supplying the power generation gas to the first flow path and the separator main body through the separator main body by the press working, and the power generation power in the second flow path. A second inlet hole for supplying gas or the cooling medium, a first outlet hole that passes through the separator body and discharges the power generation gas from the first flow path, and the separator body; A separator manufacturing method comprising a hole forming step of forming a second outlet hole for discharging the power generation gas or the cooling medium from the second flow path. A method for producing a separator used in a fuel cell that generates power by supplying a gas for power generation to a membrane electrode assembly,
A through hole forming step of forming a through hole at the intersection of the first flow path rib on the surface of the separator body and the second flow path rib on the back surface of the separator body;
A first mold having a space surrounded by an inner wall substantially the same as the shape of the first flow path rib so as to cover the through hole is disposed at the position of the first flow path rib. A mold placement step of placing a second mold having a space surrounded by an inner wall substantially the same as the shape of the second flow path rib at the position of the second flow path rib;
An injection step of injecting an elastic material from the injection port into a space surrounded by the mold inner walls of the first mold and the second mold,
A curing step for curing the elastic material;
A separator manufacturing method comprising:

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