JPH10189025A - Fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in gas sealing performance or an increase in contact resistance by keeping the direction of a pressing force applied to a fuel cell stack encased in a case so as to be always in parallel with a laminating direction of the stack. SOLUTION: In a stack stored in a stack storage hole 81A formed in a case 80A, an insulating plate 33 is disposed at an end part with the definite number of single cells laminated. A pressure plate 34 having four plate guides 35 is laminated on the outside from the insulating plate 33. Four rail parts 82 formed in a parallel direction with the laminating direction of the stack are provided in the side face in the stack storage hole 81A. When laminating the pressure plate 34, the rail parts 82 are engaged with the corresponding plate guides 35 to introduced the pressure plate 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fuel cell,
More specifically, the present invention relates to a fuel cell in which a fuel cell stack composed of unit cells is housed in a case.

[0002]

2. Description of the Related Art Conventionally, a fuel cell has been formed in a stack structure in which a large number of unit cells are stacked in order to obtain a desired electromotive force. When a fuel cell is formed as such a stack structure, the stacked state of the unit cells affects the internal resistance of the entire fuel cell. In order to realize sufficient energy efficiency in a fuel cell, it is required that the internal resistance of the fuel cell be sufficiently small. Normally, in a fuel cell, the stack structure is maintained by applying a pressing force in the stacking direction.However, by making this pressing force large enough, the contact resistance between the cells is reduced, and the internal resistance of the fuel cell is reduced. We are trying to reduce it. Further, the pressing force applied in the stacking direction in the fuel cell is also important for ensuring gas sealing properties in each unit cell.

In order to apply the above-mentioned pressing force to the stack structure and to reduce the size and simplify the configuration of the entire fuel cell, the applicant has proposed a configuration in which the entire fuel cell is housed in a case (for example, JP-A-8-1719
No. 26, etc.). In this fuel cell, a plurality of stack structures are integrally housed in a case. Here, since the number of cells required to obtain a desired electromotive force is divided into a plurality of cells, it is necessary to improve the stacking accuracy as compared to a case where all the required number of cells are formed as one stack. Thus, the internal resistance is kept low.

In the above fuel cell, the mechanism for pressurizing the stack structure is attached to a case having a predetermined rigidity, so that the whole fuel cell can be made compact. In this fuel cell, a pressurizing mechanism for pressurizing the stack structure housed in the case is provided at the end of the case. The pressure mechanism has a pressure shaft, which is screwed into a predetermined hole structure provided at the end of the case, and screwed into the hole structure to hold the pressing force against the stack structure. . The pressing force applied from the pressure shaft is transmitted to the stack structure via the pressure plate laminated on the end of the stack structure, and the entire stack structure in the case is pressed. Therefore,
In order to pressurize the stack structure, there is no need to separately provide a frame or the like having a tightening structure such as a spring, a bolt, and a nut. Further, in the above fuel cell, a predetermined fuel supply / discharge member is provided inside the case, and the fuel supply / discharge member supplies / discharges the fuel gas and the oxidizing gas to / from the plurality of stack structures housed in the case and cools the water. Supply and discharge are performed collectively. Therefore, even though the fuel cell is divided into a plurality of stack structures, the piping structure of the gas and the cooling water does not become complicated.

[0005]

The above-described fuel cell is
Although it is an excellent one that enables simplification of the whole configuration of the fuel cell, the inventor pays attention to the following points and considers the parallelism of the pressure plate (the pressure plate is perpendicular to the stacking direction of the stack structure). State). That is, in the above-described fuel cell, since the end of the pressurizing shaft has a hemispherical surface, the pressure plate to which the pressing force from the pressurizing shaft is transmitted may not be able to maintain sufficient parallelism. . If the pressure plate tilts more than the desired parallelism,
There is a possibility that the pressing force applied to the members constituting the stack structure may be non-uniform in the lamination plane (the plane parallel to the plane in which adjacent unit cells are in contact with each other).

Here, the reason why the end portion of the pressure shaft is formed in a hemispherical surface is that the pressing force generated by rotating the pressure shaft is applied to the laminated surface (the unit cells formed in a plate shape). This is for surely transmitting in a direction perpendicular to the surface (contact surface). As described above, the pressurizing shaft generates a pressurizing force by an operation involving rotation called screwing, but the pressing force generated by the tip being formed in a hemispherical surface always has a certain direction through one point of the tip. Conveyed to. In addition, a hemispherical recess corresponding to the shape of the hemispherical end of the pressing shaft is formed at the end of the stack structure that is in contact with the hemispherical end of the pressing shaft. It is possible to reliably receive the pressing force in a certain direction with a small resistance.

[0007] In a fuel cell, particularly a solid polymer electrolyte fuel cell, the electrolyte membrane is wetted during operation of the fuel cell, but when the electrolyte membrane is wetted, the electrolyte membrane swells and the cell of each unit cell is damaged. The thickness of the central portion is further increased.
When the non-uniform internal pressure is generated in each lamination plane as described above, each member may be inclined in the stack during operation of the fuel cell.

The fuel cell of the present invention solves such a problem and maintains the direction of the pressure applied to the fuel cell stack housed in the case so as to be parallel to the stacking direction of the stack. It was made for the purpose and adopted the following configuration.

[0009]

Means for Solving the Problems and Actions / Effects of the Fuel Cell The fuel cell according to the present invention is such that a fuel cell stack composed of unit cells is housed in a case, and the fuel cell stack is attached to at least one end. A fuel cell pressurized and held by a pressing member from the side, wherein a direction of a pressing force applied from the pressing member to an end of the fuel cell stack is parallel to a stacking direction of the fuel cell stack. The gist of the present invention is to provide a parallel maintaining mechanism for maintaining the degree of parallelism of the pressing surface by the pressing member.

In the fuel cell of the present invention having the above-described structure, a fuel cell stack formed by stacking unit cells is housed in a case, and the fuel cell stack is pressurized from at least one end. When the member is pressed and held, the pressing member is applied so that the direction of the pressing force applied from the pressing member to the end of the fuel cell stack is always parallel to the stacking direction of the fuel cell stack. , The parallelism of the pressing surface is maintained.

According to such a fuel cell, since the direction of the pressing force applied from the pressing member is always parallel to the stacking direction of the fuel cell stack, the internal resistance of the fuel cell is maintained at a sufficiently low state. It is possible to prevent the gas sealing performance from being deteriorated in the fuel cell stack.

In the fuel cell according to the present invention, the parallel maintaining mechanism is stacked on an end of the fuel cell stack, and transmits an applied pressure applied to an end of the fuel cell stack to the fuel cell stack. A guide part formed in a predetermined shape, and a guide part provided in the case, wherein the guide part included in the end member is guided when the fuel cell stack receives a pressing force; A configuration including a guide mechanism for keeping the member perpendicular to the stacking direction of the fuel cell stack is also preferable.

[0013] In such a fuel cell, the end member laminated on the end of the fuel cell stack and transmitting the pressing force applied to the end of the fuel cell stack to the fuel cell stack may have a predetermined shape. A guide mechanism provided in the case guides the guide portion formed in the shape. Thereby, when the fuel cell stack receives the pressing force, the end member is kept perpendicular to the stacking direction of the fuel cell stack. Therefore, even when the members constituting the fuel cell stack have an uneven thickness or an uneven internal pressure is generated in the fuel cell stack during the operation of the fuel cell, the pressure is applied via the end member. The direction of the pressing force applied from the pressure member can always be kept parallel to the stacking direction of the fuel cell stack. Therefore, the stacking surface of each member constituting the fuel cell stack can be maintained in a state perpendicular to the stacking direction of the fuel cell stack, which increases the internal resistance of the fuel cell and deteriorates the gas sealing property. There is no end.

In such a fuel cell, the guide mechanism engages with the guide portion provided on an end member of the fuel cell stack to guide the end member of the fuel cell stack. And may be formed on the wall surface of the case in parallel to the stacking direction of the fuel cell stack.

In such a fuel cell, the guide portion provided on the end member is guided by the guide mechanism, which is a rail formed on the wall surface of the case in parallel to the stacking direction of the fuel cell stack. I will Therefore, when the end member is stacked on the end of the fuel cell stack, the guide member provided on the end member is engaged with the guide mechanism, so that the end member is stacked on the fuel cell stack. The above-mentioned effect can be obtained by maintaining the state perpendicular to the direction.

Alternatively, in the fuel cell according to the present invention, the guide portion provided on the end member of the fuel cell stack has an engaging portion projecting in a predetermined shape, and the guide mechanism is provided in the case. And a notch formed in parallel with the stacking direction of the fuel cell stack and engaged with the engaging portion of the guide portion to guide an end member of the fuel cell stack.

In such a fuel cell, the guide mechanism, which is a notch formed in the case in a direction parallel to the stacking direction of the fuel cell stack, has a predetermined shape provided by a guide provided on an end member. And the guide portion is guided. Therefore, when stacking the end member on the end of the fuel cell stack, the end member is engaged with the guide mechanism by engaging the engaging portion of the guide provided on the end member with the guide mechanism. The above-mentioned effect can be obtained by maintaining the state perpendicular to the stacking direction of the stack.

The fuel cell according to the present invention may further include a frictional force reducing unit configured to reduce a frictional force generated between the guide unit and the guide mechanism provided on an end member of the fuel cell stack. Is also good.

With this configuration, the operation of laminating the end members on the ends of the fuel cell stack can be performed smoothly.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the structure and operation of the present invention described above, embodiments of the present invention will be described below based on examples. FIG. 1 is a perspective view showing an overview of a fuel cell 10 according to a preferred embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating an outline of an internal configuration of the fuel cell 10.

The fuel cell 10 is formed by stacking single cells.
Stacks 11A to 11D and the stacks 11A to 11D
Fuel supply / discharge unit 4 that supplies / discharges fuel etc. to 11D
0, cases 80A and 80B forming storage containers for the stacks 11A to 11D, and a pressing mechanism 110 for applying pressure to the stacks 11A to 11D in the stacking direction. First, the stacks 11 </ b> A to 11 </ b> D that are the main components of power generation in the fuel cell 10 will be described.

Each of the stacks 11A to 11D is configured as a solid polymer electrolyte type fuel cell, and is formed by stacking a plurality of unit cells 12 as structural units. The electrochemical reaction that proceeds in the solid polymer electrolyte fuel cell is shown below.

H ₂ → 2H ⁺ + 2e ⁻ (1) (1/2) O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (2) H ₂ + (1/2) O ₂ → H ₂ O (3) )

Equation (1) represents the reaction on the anode side,
Equation (2) represents the reaction on the cathode side, and the reaction shown in equation (3) proceeds in the entire fuel cell. As described above, the solid polymer electrolyte fuel cell receives the supply of the fuel gas containing hydrogen on the anode side, and receives the supply of the oxidizing gas containing oxygen on the cathode side, and proceeds the above reaction to generate an electromotive force. obtain. FIG. 3 is a cross-sectional view illustrating the configuration of the single cell 12 configuring the stacks 11A to 11D. The single cell 12 includes an electrolyte membrane 13, an anode 14 and a cathode 15, and separators 16 and 17.

The anode 14 and the cathode 15 are gas diffusion electrodes having a sandwich structure sandwiching the electrolyte membrane 13 from both sides. The separators 16 and 17 form a flow path for fuel gas and oxidizing gas between the anode 14 and the cathode 15 while further sandwiching the sandwich structure from both sides. A fuel gas flow path 16P is formed between the anode 14 and the separator 16, and the cathode 1
An oxidizing gas flow path 17P is formed between 5 and separator 17. Although the separators 16 and 17 each have a flow path formed only on one side in FIG. 3, ribs are actually formed on both sides thereof, and a fuel gas flow path 16 P is formed on one side with the anode 14. The other surface forms an oxidizing gas flow path 17P with the cathode 15 provided in the adjacent single cell. As described above, the separators 16 and 17 form a gas flow path with the gas diffusion electrodes, and play a role of separating the flows of the fuel gas and the oxidizing gas between the adjacent single cells.

Here, the electrolyte membrane 13 is made of a solid polymer material, for example, a fluororesin having a thickness of 100%.
It is a proton conductive ion exchange resin of μm to 200 μm and shows good electric conductivity in a wet state. In this example, a Nafion membrane (manufactured by DuPont) was used. The surface of the electrolyte membrane 13 is coated with platinum as a catalyst or an alloy composed of platinum and another metal. As a method of applying the catalyst, a carbon powder supporting platinum or an alloy of platinum and another metal is prepared, and the carbon powder supporting the catalyst is dispersed in an appropriate organic solvent, and an electrolyte solution (for example, Aldrich Chemical) is used. Company, Na
An appropriate amount of F.Solution was added to form a paste, and screen printing was performed on the electrolyte membrane 13. Alternatively, a configuration in which a paste containing the carbon powder supporting the catalyst is formed into a film to form a sheet and the sheet is pressed on the electrolyte membrane 13 is also suitable.

The anode 14 and the cathode 15 are both formed of a carbon cloth woven with carbon fiber yarns. In the present embodiment, the anode 14 and the cathode 15 are formed by carbon cloth, but a configuration formed by carbon paper or carbon felt made of carbon fiber is also suitable. In the present embodiment, as described above, the catalyst made of platinum or the like is used for the electrolyte membrane 1.
Although it is configured to adhere on the surface 3, a paste of a catalyst made of platinum or the like may be adhered to the surfaces of the anode 14 and the cathode 15 in contact with the electrolyte membrane 13.

The electrolyte membrane 13 and the anode 14 and the cathode 15 are integrated by thermocompression bonding. That is, the electrolyte membrane 13 coated with a catalyst such as platinum is sandwiched between the anode 14 and the cathode 15,
These are pressure-bonded while heating to 0 ° C, preferably 120 ° C to 130 ° C. As a method of integrating the electrolyte membrane 13 with the anode 14 and the cathode 15, a bonding method may be used instead of thermocompression bonding. Anode 1
When the electrolyte membrane 13 is sandwiched between the electrode 4 and the cathode 15, a proton conductive solid polymer solution (for example, Aldrich Chemical Company,
When bonding is performed using Nafion Solution, the electrodes function as an adhesive in a home where the proton-conductive solid polymer solution solidifies, and the electrodes and the electrolyte membrane 13 are fixed.

The separators 16 and 17 are made of a gas-impermeable conductive material, for example, dense carbon which is made by compressing carbon to be gas-impermeable. Separator 1
Each of the surfaces 6 and 17 has a plurality of ribs arranged in parallel to form the above-described gas flow path. In FIG. 3, the fuel gas passage 16P and the oxidizing gas passage 17P are shown in parallel, but in the fuel cell 10 of the present embodiment, the fuel gas passage 16P and the oxidizing gas passage 17P are orthogonal to each other. It was formed so that. The shape of the rib formed on the surface of each separator may be any shape as long as a fuel gas or an oxidizing gas can be supplied to the gas diffusion electrode.

FIG. 4 shows the stacks 11A to 11A of this embodiment.
D shows how the single cells 12 are actually stacked in an exploded perspective view. The separators 16 and 17 are end separators 18 and 1 in the actual stacks 11A to 11D.
9, the center separator 20 and the cooling separator 21. These separators are formed into a plate shape having a square lamination surface. Hereinafter, the structure of each of the above separators will be described.

The end separators 18, 19, the center separator 20, and the cooling separator 21 are formed with cooling water holes 22, 23 having circular cross sections at two peripheral corners (upper corners in FIG. 4). Have been. These cooling water holes 22, 23
When the above-mentioned stack is formed, a flow path of cooling water penetrating the stack in the stacking direction is formed. A pair of elongated holes (oxidizing gas holes) 24 and 25 and a pair of holes (fuel gas holes) 26 and 27 are formed near the edges of each side of the laminated surface of the three types of separators along the side. ing. When the stack is formed, the oxidizing gas holes 24 and 25 and the fuel gas holes 26 and 27 are formed so as to penetrate the flow path of the oxidizing gas containing oxygen and the fuel gas containing hydrogen in the stacking direction of the stack. .

On one surface (the front side in FIG. 4) of the end separator 18, there are formed a plurality of parallel groove-shaped ribs 28 communicating between the opposing oxidizing gas holes 24 and 25. Rib 2
8 are adjacent cathodes 15 when a stack is formed.
The oxidizing gas flow path 17P described above is formed between. The other surface of the end separator 18 is a flat surface without a groove structure.

On one surface (the front side in FIG. 4) of the central separator 20, there are formed a plurality of parallel groove-shaped ribs 28 which communicate between the opposing oxidizing gas holes 24 and 25. Rib 2
8 are adjacent cathodes 15 when a stack is formed.
The oxidizing gas flow path 17P described above is formed between. On the other surface of the center separator 20, opposed fuel gas holes 26,
27, a plurality of groove-shaped ribs 29 which are orthogonal to the ribs 28 are formed. When the stack is formed, the rib 29 forms the fuel gas flow path 16 </ b> P described above with the adjacent anode 14.

A plurality of parallel groove-shaped ribs 29 are formed on one side (the back side in FIG. 4) of the cooling separator 21 to communicate between the opposed fuel gas holes 26 and 27. Rib 2
9 are adjacent anodes 14 when a stack is formed.
And the fuel gas flow path 16P described above is formed. Further, on the other surface of the cooling separator 21 (the front side in FIG. 4),
The concavity-shaped groove 3 that connects between the cooling water holes 22 and 23 described above.
0 is formed. When the stack is formed, the cooling separator 21 is adjacent to the end separator 18 as described later, but at this time, the groove 30 forms a cooling water passage 31P between the cooling separator 21 and the flat surface of the end separator 18.

Although the above three types of separators are formed of dense carbon as described above, they may be formed of other conductive members. For example, the end separators 18 and 19 and the cooling separator 21 may be formed of a metal such as a copper alloy or an aluminum alloy with emphasis on rigidity and heat conductivity.

When the stacks 11A to 11D are formed, the structure in which the electrolyte membrane 13 is sandwiched between the anode 14 and the cathode 15 is assembled by further sandwiching the above-mentioned separators from both sides. In FIG. 4, the end separators 18,
Although only one center separator 20 and one cooling separator 21 are shown, when actually forming the stacks 11A to 11D, a predetermined number of the center separators 20 are continuously stacked. The number of successively stacked central separators 20 (or the ratio of the cooling separators 21 in the stack) is determined by conditions such as the calorific value of the single cell 12, the temperature of the cooling water, the flow rate of the cooling water, and the like. In this embodiment, the end separator 18 and the cooling separator 21 are arranged every five consecutive center separators 20.

As described above, the electrolyte membrane 13 and the anode 1
4, stacks 11A to 11D formed by laminating the cathode 15 and each separator are adjacent stacks 11A
And the stack 11B and the adjacent stacks 11C and 11D constitute the fuel cell 10 with the fuel supply / discharge unit 40 interposed therebetween. Here, the stacking direction (the order in which the anodes 14 and the cathodes 15 are arranged during stacking) in each stack and the structure of the end of each stack will be described.

In this embodiment, the stacks 11A and 11C are formed by stacking the stacks in the same direction, and the stacks 11B and 11D are formed by stacking the stacks in the opposite direction. At both ends of each of the stacks 11A to 11D, end separators are arranged adjacent to the central separator 20 that is continuous with five sheets. Here, one end of the stacks 11A and 11C (the right rear side in FIG. 2) and the stack 11
B, an end separator 18 is arranged on the other end side (the left front side in FIG. 2) of the stack 11D (however, the stacks 11A and 11C and the stacks 11B and 11D are arranged in opposite directions). Further, end separators 19 are arranged at the other ends of the stacks 11A and 11C (left front side in FIG. 2) and at one ends of the stacks 11B and 11D (right rear side in FIG. 2) (however, the stack 11A). , 11C and the stacks 11B, 11D are arranged in opposite directions to each other). This end separator 19
Has the same structure as the end separator 18 described above, but the arrangement of the surface on which the ribs are formed on the surface and the flat surface is opposite to that of the end separator 18 shown in FIG. Has become. That is, the rib is formed on the surface adjacent to the anode 14, and the opposite surface is a flat surface. Here, the rib formed on the end separator 19 communicates between the fuel gas holes 26 and 27 and communicates with the anode 14 through the fuel gas flow path 16P, similarly to the rib 29 on the center separator 20 shown in FIG. To form

Further, in each of the stacks 11A to 11D, on the end side corresponding to the end of the entire fuel cell 10, the current collector plate 3 is provided outside the end separator 18 or 19.
2, an insulating plate 33 and a pressure plate 34 are further arranged in this order. These current collecting plate 32, insulating plate 33,
The pressure plate 34 has substantially the same shape as each of the separators described above. However, it does not have a hole structure or a rib structure related to supply and discharge of gas and cooling water.

Here, the current collecting plate 32 is formed of a highly conductive material, for example, copper or the like. A terminal (not shown) for taking out an output from the fuel cell 10 is provided at a predetermined position of the current collector plate 32. The insulating plate 33 is formed of an insulating material, for example, rubber or resin. Alternatively, the insulating plate 33 may be formed by covering the surface of a conductive member such as a metal with an insulating member. The pressure plate 34 is formed of a highly rigid material, for example, steel. The pressure plate 34 has a configuration corresponding to the main part of the present invention, and will be described later in detail.

In each of the stacks 11A to 11D, on the end side adjacent to the fuel supply / discharge section 40, the current collector plate 32A and the insulating plate 33 are provided outside the end separator 18 or 19.
A are further arranged in this order. These current collectors 32
A, the insulating plate 33A includes the current collecting plate 32 and the insulating plate 33 described above.
The cooling water holes 22 and 23, the fuel gas holes 26 and
27, a hole structure corresponding to the oxidizing gas holes 24 and 25 is provided. The current collecting plate and the insulating plate correspond to the fuel cell 1
In order to ensure the durability of the fuel cell 10, it is desirable that the fuel cell 10 be formed of a material that is excellent in durability against fuel gas, oxidizing gas, and water and that is stable at the operating temperature of the fuel cell 10. Stack 1 thus stacked
1A to 11D are adjacent to the fuel supply / discharge unit 40 via the insulating plate 33A.

FIG. 5 is a perspective view showing an overview of the fuel supply / discharge unit 40. The fuel supply / discharge unit 40 is formed in a rectangular parallelepiped shape from aluminum. This fuel supply / discharge unit 40
Supplies fuel gas, oxidizing gas, and cooling water from a fuel gas supply / discharge device, an oxidizing gas supply / discharge device, and a cooling water supply / discharge device (not shown) to the stacks 11A to 11D and the fuel discharged from the stacks 11A to 11D. This is a device for returning exhaust gas, oxidizing exhaust gas, and cooling water to a fuel gas supply / discharge device, an oxidizing gas supply / discharge device, and a cooling water supply / discharge device. For this reason,
The fuel supply / discharge unit 40 connects a fuel gas supply / discharge device to each of the stacks 11A to 11D, and a fuel gas supply / discharge passage, and an oxidizing gas supply / discharge device to each of the stacks 11A to 11D. A flow path for supplying and discharging the oxidizing gas and a flow path for supplying and discharging the cooling water that connects the cooling water supply and discharge device to each of the stacks 11A to 11D are formed.

First, the flow path for supplying and discharging the cooling water will be described. Cooling water supply ports 42A to 42D for receiving cooling water from a cooling water supply / discharge device are formed on both sides of the center of the upper surface of the fuel supply / discharge section 40, and the cooling water supply ports are provided at four corners of the same surface. Cooling water outlet 46A that returns cooling water to the supply / discharge device
To 46D are formed (see FIG. 5). Further, the cooling water from the cooling water supply / discharge device is stacked in the upper center of one side surface (the right side surface in FIG. 5) of the fuel supply / discharge unit 40.
The cooling water supply connection ports 44A and 44B for supplying to the stacks 11A and 1B are provided at both upper corners of the same surface.
Cooling water discharge connection ports 48A and 48B for receiving the cooling water discharged from 1B are formed. The other side (the left side of the fuel supply / discharge unit 40 shown in FIG. 1) of the fuel supply / discharge unit 40 is also provided with the cooling water supply connection port 44 similarly to this surface.
C, 44D and cooling water discharge connection ports 48C, 48D are formed. The cooling water supply ports 42A to 42D, the cooling water supply connection ports 44A to 44D, and the cooling water discharge port 4
6A to 46D and the cooling water discharge connection ports 48A to 48D
The inside of the fuel supply / discharge unit 40 is connected by a flow path formed in a predetermined shape.

Accordingly, the fuel supply / discharge unit 40 supplies the cooling water from the cooling water supply / discharge device to the cooling water supply ports 42A to 42D.
The cooling water is supplied to the stacks 11A to 11D via the cooling water supply connection ports 44A to 44D. The cooling water supplied to each stack is discharged to the cooling water supply / discharge device via cooling water discharge ports 48A to 48D and cooling water discharge ports 46A to 46D via cooling water channels formed inside the stack. You.

Next, the flow path for supplying and discharging the fuel gas will be described. In the center of one side surface (the right side surface in FIG. 5) of the fuel supply / discharge unit 40, two fuel gas supply lines which are vertically elongated in the figure and which supply fuel gas from the fuel gas supply / discharge device to the stacks 11A and 11B are provided. Connection ports 62A and 62B are formed, and two elongated fuel gas discharges for receiving the fuel exhaust gas discharged from the stacks 11A and 11B are provided near the edges of the sides facing the fuel gas supply connection ports 62A and 62B. Connection ports 64A and 64B are formed. The other side surface of the fuel supply / discharge unit 40 (the left side surface of the fuel supply / discharge unit 40 shown in FIG. 1) is also provided with the fuel gas supply connection ports 62C and 62D and the fuel gas discharge connection port similar to this surface. 64C, 6
4D is formed.

Further, the fuel supply / discharge section 40 has a side surface different from the fuel gas supply connection ports 62A to 62D and the fuel gas discharge connection ports 64A to 64D (right rear side surface in FIG. 5). Further, a fuel gas supply port 50 for receiving the supply of the fuel gas from the fuel gas supply / discharge device is formed. The fuel gas supply / discharge unit 40 has a fuel gas discharge port for discharging fuel exhaust gas to a fuel gas supply / discharge device on a surface (the left side surface in FIG. 5) opposite to the surface on which the fuel gas supply port 50 is formed. An outlet 59 is formed. The fuel gas supply port 50 and the fuel gas supply connection ports 62A to 62D, and the fuel gas discharge connection ports 64A to 64D and the fuel gas discharge port 59 are formed in a predetermined shape inside the fuel supply / discharge section 40. They are connected by a channel.

Therefore, the fuel supply / discharge unit 40 supplies the fuel gas from the fuel gas supply / discharge device to the stacks 11A to 11D via the fuel gas supply port 50 and the fuel gas supply connection ports 62A to 62D. The fuel gas supplied to each stack is supplied to the electrochemical reaction via a fuel gas flow passage formed inside the stack, and is supplied through the fuel gas discharge connection ports 64A to 64D and the fuel gas discharge port 59. The gas is discharged to the gas supply / discharge device.

Next, the flow path for supplying and discharging the oxidizing gas will be described. An oxidizing gas distribution groove 70 including an annular groove and four grooves formed in four corners from the annular groove is formed at the center of the upper surface of the fuel supply / discharge unit 40. 5). Oxidizing gas supply ports 71A to 71D having a circular cross section are formed at the tips of the four grooves formed toward the four corners of the oxidizing gas distribution groove 70. The oxidizing gas distribution groove 70 is connected to an oxidizing gas supply / discharge device (not shown). In the fuel supply / discharge unit 40, an oxidizing gas from the oxidizing gas supply / discharge device is supplied to the stacks 11A and 11B on the upper side of the same side where the fuel gas supply connection ports 62A and 62B are formed. Two elongated oxidizing gas supply connection ports 72A and 72B are formed, and two elongated oxidizing gas discharge connection ports 74A and 7 for receiving oxidizing exhaust gas discharged from the stacks 11A and 11B are formed at a lower portion.
4B is formed. The oxidizing gas supply connection ports 72C and 72D and the oxidization gas discharge connection ports 74C and 74D similar to this surface are also provided on the surface (the left side surface of the fuel supply / discharge unit 40 shown in FIG. 1) opposite to this surface. Is formed.

In the fuel supply / discharge section 40, a surface (a lower surface in FIG. 5) opposite to the surface on which the oxidizing gas distribution groove 70 is formed has an oxidizing gas having the same shape as the oxidizing gas distribution groove 70. A gas outlet 78 is formed. In the oxidizing gas discharge section 78, the oxidizing gas discharge ports 76A to 76C having circular cross sections are provided at the tips of the four grooves formed toward the four corners.
76D is formed. The oxidizing gas discharge unit 78
It is connected to an oxidizing gas supply / discharge device (not shown). The oxidizing gas supply ports 71A to 71D and the oxidizing gas supply connection ports 72A to
72D and the oxidizing gas discharge connection ports 74A to 74D and the oxidizing gas discharge ports 76A to 76D
The inside is connected by a flow path formed in a predetermined shape.

Therefore, the fuel supply / discharge section 40 supplies the oxidizing gas from the oxidizing gas supply / discharge device to the oxidizing gas supply ports 71A-71.
The fuel is supplied to the stacks 11A to 11D via the oxidizing gas supply connection ports 72A to 72D. The oxidizing gas supplied to each stack is subjected to the above-described electrochemical reaction via an oxidizing gas flow passage formed inside the stack, and is connected to the oxidizing gas discharge connection ports 74A to 74D and the oxidizing gas discharge port 7.
The fuel gas is discharged to the fuel gas supply / discharge device via 6A to 76D.

Next, the configuration of the cases 80A and 80B and how the cases 80A and 80B accommodate the stacks 11A to 11D will be described. Case 80A, 80B
Is formed of a steel plate material, and its inner wall surface is covered with an insulating member. The case 80A houses the stacks 11A and 11B, and the case 80B houses the stacks 11C and 11D. Here, since the case 80A and the case 80B have the same configuration, the case 80A will be described below. FIG.
FIG. 2 is a sectional view taken along line EE of the fuel cell 10 shown in FIG. 1. The case 80A includes a stack storage hole 81A for storing the stack 11A and a stack storage hole 81B for storing the stack 11B.

Inside each of the stack storage holes 81A and 81B, two rail portions 82 are formed on each side surface. That is, each stack storage hole 81A,
81B includes four rail portions 82, respectively.
Each rail portion 82 formed on the side surface corresponding to the side surface of the entire fuel cell 10 has two parallel elongated shapes formed vertically from the side surfaces in the stacking direction of the stack on the inner walls of the stack storage holes 81A and 81B. It is constituted by a plate-like structure. Each rail portion 82 provided on the side surface on the side where the stack storage holes 81A and 81B are adjacent to each other
It is constituted by the shape of the irregularities formed on the wall surface of A. Here, the distance between the adjacent rail portions 82 corresponds to the position of a later-described plate guide 35 provided in the pressure plate 34 described above. These rails 82
The structure of the pressure plate 34 corresponds to a main part of the present invention, and will be described later in detail.

Further, positioning portions 83A and 83B are formed at predetermined positions of the bottom surfaces of the stack storage holes 81A and 81B, respectively, in the stacking direction of the stack. The alignment portions 83A and 83B are formed as elongated plate-like structures perpendicular to the bottom surfaces of the stack storage holes 81A and 81B. This alignment unit 83A,
83B is a structure for adjusting the position along the corners of the stack components being stacked when storing the stacks 11A and 11B in the stack storage holes 81A and 81B.

Further, the case 80A is formed with a reinforcing portion 84 connecting the side where the stack storage hole 81A is formed and the side where the stack storage hole 81B is formed. The reinforcing portion 84 has a beam structure formed in the stacking direction of the stack at an intermediate portion between the upper rail portion 82 and the lower rail portion 82 of the two sets of facing rail portions 82. In the stack storage holes 81A and 81B, pressing force is applied from the side to the stacks 11A and 11B stored therein via a plate guide 35 described later.
The reinforced portion 84 gives the case 80A strength to withstand this pressing force.

Although the configuration of the case 80A has been described above, the case 80B for storing the stack 11C and the stack 11D has the same configuration. It should be noted that a case 8 is provided at both ends of the case 80A and the case 80B.
0A and 80B are supplied to the fuel supply / discharge unit 40 and the pressurizing mechanism 110.
A bolt hole is formed to fix the bolt.

Here, the stack 11 is placed in the case 80A.
A state in which A and 11B are stored will be described. First, the case 80A is connected to the fuel supply / discharge unit 4 using the bolt holes described above.
Fix to 0. Subsequently, the stacks 11A and 11B are stored in the stack storage holes 81A and 81B provided in the case 80A fixed to the fuel supply / discharge unit 40. Stack 11
A and 11B are stored in the unit cells 12 constituting each stack.
May be stacked one by one in order, or a predetermined number of single cells 12 may be stacked for each module. The module is a module in which a predetermined number of single cells 12 are applied in advance to a predetermined number of single cells 12 and adhered to a peripheral portion thereof to be integrated.
By thus modularizing the single cells 12 in advance, it is possible to reduce the number of components at the time of lamination and facilitate the operation of laminating the stack. In addition, since the constituent members of the stack are compressed to some extent in advance for each module by modularizing the single cells 12 in advance, when the stacks 11A and 11B are stored in the case 80A, the stacks 11A and 11B are pressed by the pressing mechanism 110. Before stacking, the length of each stack in the stacking direction can be further reduced. That is, the length in the stacking direction of the case 80A required for the stacking operation can be made shorter, and can be made closer to the length of the stack when completed by applying pressure.

When stacking the single cells 12 or the modules in the stack storage holes 81A and 81B, one of the corners of the single cells 12 or the modules is aligned with the above-described alignment portions 83A and 83B. Laminate.
As described above, by aligning the corners of the single cell 12 or the module along the alignment portions 83A and 83B, the stack required to form the fuel gas passage, the oxidizing gas passage, and the cooling water passage that penetrates the inside of the stack is formed. Accuracy is ensured.

At the end of each stack, as described above,
Current collector plate 32, insulating plate 3 adjacent to a predetermined end separator;
3 and the pressure plate 34 are stacked. FIG.
FIG. 9 is an explanatory diagram showing a state in which a pressure plate 34 is further stacked in a stack storage hole 81A in which the insulating plate 33 is stacked. This structure for guiding the pressure plate 34 when the pressure plate 34 is stored in the stack storage hole 81A corresponds to the main part of the present invention. The pressure plate 34 is provided with four plate guides 35 at predetermined positions around the lamination surface (the description of the plate guides 35 is omitted in each stack shown in FIG. 1). In the present embodiment, corresponding to the position of the rail portion 82 described above, each of the pressure plates 34 has a pair of opposed two parallel to the side surface of the fuel cell 10.
Each side is provided with two plate guides 35 (see FIG. 7). These plate guides 35 are formed of a material having an insulating property and a predetermined strength, such as a resin. Alternatively, a configuration may be employed in which a conductive material such as a metal is used and the surface is covered with an insulating member.

FIG. 8 is a sectional view (sectional view taken along line FF) of the fuel cell 10 shown in FIG. 1 taken along a plane corresponding to the plane on which the pressure plate 34 is provided. The plate guide 35 has a substantially square cross section when viewed from the end of the stack, and is fitted into the pressure plate 34 such that the longitudinal direction thereof is the stacking direction of the stack. The plate guide 35 is a pressure plate 34
The portion protrudes from the outer peripheral portion of the rail, and the protruding portion is engaged with the rail portion 82 described above. In addition, the end on the side adjacent to the insulating plate 33 already stacked in the stack storage holes 81A and 81B has a shape in which a region overlapping with the stacked surface is cut off according to the shape of the insulating plate 33 and the like. (See FIG. 7). In the plate guide 35, a ball bearing 36 is provided at a predetermined position on an outer peripheral surface of the plate guide 35 which abuts on an inner wall of the rail portion 82.

When the pressure plate 34 is housed in the stack housing hole 81A, the four plate guides 35 are engaged with the four rails 82 formed in the stack housing hole 81A, respectively. Then, the pressure plate 34 is pushed into the stack storage hole 81A. Here, as described above, each rail portion 82 is formed parallel to the stacking direction of the stack, and the plate guide 35 is also formed so that its longitudinal direction is parallel to the stacking direction of the stack. Therefore, when the plate guide 35 is pushed in while being engaged with the rail portion 82, the pressure plate 34 is housed in the stack housing hole 81A while being kept perpendicular to the stacking direction of the stack.
Further, since the ball bearing 36 is provided at a predetermined position on the outer peripheral surface of the plate guide 35 as described above, the pressure plate 34 is attached to the stack accommodation hole 81A.
Resistance when pushing into the inside is reduced.

As described above, the stack 1 is inserted into the stack accommodation hole 81A.
Although the state of storing the stack 11A has been described, the stack 11B can be stored in the stack storage hole 81B in the same manner. Also, the stacks 11C and 11C are placed in the case 80B.
The same applies to the case where D is stored. Stacks 11A to 11A are provided in cases 80A and 80B fixed to fuel supply / discharge unit 40.
After storing D, each stack is pressurized by the pressurizing mechanism 110 to complete the fuel cell 10.

In the case 80A, 80B of the fuel cell 10 shown in FIG. 1, each side surface is formed as a flat plate structure. However, the inside of the stack accommodating hole is formed on the side surface of the case 80A, 80B from outside. It is also preferable to provide an observable window structure by punching or the like. If such a window structure is provided, cases 80A, 80B
When stacking the stacks 11A to 11D inside, the state of the single cells 12 or modules being stacked can be easily known from the outside, and the state of the single cells 12 or modules having an undesired inclination can be determined. Correction can be easily performed, and convenience at the time of lamination can be achieved.

Next, the pressing mechanism 110 will be described.
FIG. 9 is a cross-sectional view illustrating the configuration of the pressing mechanism 110. As shown, the pressing mechanism 110 includes a pressing mechanism 11.
0 to the case 80, a rotation preventing member 120 for transmitting a reaction force accompanying pressurization by a pressure bolt 140 described later to the mount plate 112,
Each of the stacks 11A to 11D includes a pressing member 130 for applying a pressure in the stacking direction and a pressing bolt 140 for applying a pressing force to the pressing member 130. Two regular octagonal through holes 114 are formed in the mounting plate 112, and the rotation preventing member 120 is fitted into the through holes 114.

FIG. 10 is an explanatory view of the rotation preventing member 120 as viewed from the right side in FIG. As shown in the figure, the rotation preventing member 120 has a circular pedestal portion 122 that transmits a reaction force accompanying pressurization by the pressurizing bolt 140 to the mounting plate 112,
The fitting portion 124 is a regular octagon and can be fitted into the through hole 114 of the mounting plate 112. In the center of the fitting portion 124,
A through hole 126 penetrating through the fitting portion 124 is formed.
A spiral groove is formed so as to be screwed with the No. 0 thread part 144. Note that the rotation preventing member 120 shown in FIG. 9 corresponds to a cross section taken along line GG of the rotation preventing member 120 shown in FIG.

FIG. 11 is an explanatory view of the pressing member 130 as viewed from the right side in FIG. As shown, the pressing member 130
Is a disk 132 for applying a pressing force to the stacking ends of the stacks 11A to 11D, a pressing shaft 136 attached to the center of the disk 132, and reinforcing the disk 132 and the pressing shaft 136 to form a triangle. And four pressing ribs 134. At an end (right end in FIG. 9) of the pressing shaft 136, a hemispherical pressing recess 138 is formed.

The pressure bolt 140 is, as shown in FIG.
One end 142 is formed in a hemispherical shape so as to be aligned with the pressing recess 138 of the pressing member 130, and the other end 1 is formed.
46 is formed so that its cross section becomes hexagonal. Between the end 142 and the end 146 of the pressure bolt 140 is a screw 144 having a spiral groove formed to screw into the through hole 126 of the rotation preventing member 120.

The pressure mechanism 110 configured as described above applies a pressure in the stacking direction to the stacks 11A to 11D as follows. When the pressure bolt 140 screwed into the through hole 126 of the rotation preventing member 120 is rotated, the pressure bolt 1
Reference numeral 40 moves in the left-right direction in FIG. Pressure bolt 14
0 is rotated clockwise and the pressure bolt 140 is moved to the left in FIG.
2 comes into contact with the pressing recess 138 of the pressing member 130, and moves the pressing member 130 to the left. Therefore, stack 1
A pressure in the stacking direction is applied to 1A to 11D by the disk 132 of the pressing member 130. The stacks 11A to 11A stored in the cases 80A and 80B fixed to the fuel supply / discharge unit 40 using the pressurizing mechanism 110 configured as described above.
D is pressurized to form the fuel cell 10.

In the fuel cell 10 shown in FIG. 1, the terminals of the current collecting plate 32 described above are omitted, but the ends of each of the stacks 11A to 11D are described above. Electric boards 32 and 32A are provided, and these are connected as follows. That is, the stack 11A
The terminal of the current collecting plate 32A provided at the end of the fuel supply / discharge unit 40 on the side of the fuel supply / discharge unit 40
A current collector plate 32 provided at the end of the 1C fuel supply / discharge unit 40 side
A terminal. The terminals of the current collector 32 provided at the end of the stack 11C on the pressing mechanism 110 side are connected to the terminals of the current collector 32 provided at the end of the adjacent stack 11D on the side of the pressing mechanism 110. . The terminal of the current collector 32A provided at the end of the stack 11D on the side of the fuel supply / discharge unit 40 is connected to the stack 11B facing the fuel supply / discharge unit 40.
Is connected to the terminal of the current collector 32A provided at the end of the pressure mechanism 110 side.

Here, as described above, the stack 11
A, 11C and stacks 11B, 11D are single cells 12
The stacking directions of the stacks 11A to 11D are reversed by connecting the connection terminals at the ends of the stacks as described above.
1D and 11B are connected in series in this order. Stack 11A
11D are connected in series as described above, the stack 1
The terminal of the current collecting plate 32 provided at the end of the pressurizing mechanism 110 of 1A and the terminal of the current collecting plate 32 provided at the end of the stack 11B at the side of the pressing mechanism 110 are output terminals of the fuel cell 10. , Power can be obtained from these terminals.

In the fuel cell 10 of this embodiment, the stack 1
1A to 11D are stacked 11A, 11C, 11D, 11
B is connected in series in the order of B, but may be connected in series in a different order, or the stacks 11A to 11D may be connected in parallel. Alternatively, each of the stacks 11A to 11A
Two of D may be connected in series, and the two sets connected in series may be further connected in parallel.

According to the fuel cell 10 of this embodiment configured as described above, the plate guide 35 mounted on the pressure plate 34 in parallel with the lamination direction is used.
Since the rails 82 formed parallel to the stacking direction on the inner walls of the cases 80A and 80B guide the stacks 11A to 11D by the pressing mechanism 110, the stacking surface of the pressure plate 34 is moved in the stacking direction of the stacks. It can be kept vertical. Therefore, a uniform pressing force can be applied to the stacking surfaces of the members constituting the stacks 11A to 11D. Since a uniform pressing force is applied to the stacking surface, the contact resistance becomes uniform in each stack, and the internal resistance of the fuel cell 10 does not increase. Further, since the entire stack is sufficiently pressurized, there is no possibility that the gas sealing property is partially impaired.

According to the fuel cell 10 of this embodiment,
Even after the stacks 11A to 11D are pressurized to complete the fuel cell 10, the plate guide 35 and the rail 8
Due to 2, the state where the lamination surface of the pressure plate 34 is perpendicular to the lamination direction of the stack is maintained. Therefore, during operation of the fuel cell 10, each of the stacks 11A to 11A
Inclination does not occur in any of the members constituting 1D. During operation of the fuel cell 10, as the electrolyte membrane 13 becomes wet, the thickness of the central portion of each unit cell 12 where no bonding is performed further increases. Each unit cell 12 has a thickness of several millimeters, and the thickness that increases for each unit cell 12 is insignificant. However, in the entire stack in which dozens or more unit cells 12 are stacked, the center of the stacking surface is The increase in thickness at this point is not negligible. The pressure plate 34 disposed at the end of the stack in which the single cells 12 (or a module in which a predetermined number of the single cells 12 are integrated) having a thick central portion and a thin peripheral portion is disposed during the operation of the fuel cell 10. As the central portion of each unit cell 12 becomes thicker, there is a possibility that a force for tilting the pressure plate 34 in any direction may act.
Since the pressure plate 34 is supported by the plate guide 35 and the rail portion 82, the stacking surface of the pressure plate 34 can be maintained in a state perpendicular to the stacking direction of the stack. Therefore, the fuel cell 10
During the operation, the pressure plate 34 tilts, and the pressing force applied to the stacking surface of each of the stacks 11A to 11D becomes uneven in the stacking surface, and the gas sealing property is impaired or the contact resistance increases. Absent.

In the first embodiment, each stack accommodation hole 8
The rail portions 82 provided in 1A to 81D are formed by two elongated plate-like structures provided in parallel to the stacking direction on the side surface corresponding to the outer side surface of the fuel cell 10, and the rail portion 82 on the side facing these side surfaces is provided. The side surfaces are formed by molding the side walls of the cases 80A and 80B into a predetermined uneven shape. These rail portions are provided with stack storage holes 81A-8A.
All may be formed by two elongated plate-like structures provided in 1D, or all may be formed by molding the side walls of the cases 80A and 80B into a predetermined uneven shape.

In the first embodiment, each of the stack housing holes is provided with two opposite side surfaces.
Although the two rail portions 82 are provided, the rail portions 82 may be provided on a surface different from that of the first embodiment. An example is shown below. FIG. 12 is an explanatory diagram showing a state of the fuel cell 10A in which the rail portion 82 is provided on one side surface and the upper surface of the stack housing hole. FIG. 12 shows the fuel cell 1
At 0A, the pressure plate 34 is
Shows the state of the cross section including. Here, members in common with the fuel cell 10 of the first embodiment are assigned the same reference numerals and detailed description is omitted. However, in the following embodiments described below, portions common to the first embodiment will be described. Are assigned the same member numbers, and a detailed description thereof will be omitted.
In the fuel cell 10A, two rail portions 82 are formed on one side surface (the left side surface in FIG. 12) and the upper surface (the upper side surface in FIG. 12) in the stack storage holes 81A and 81B, respectively. In (2), a plate guide 35 is formed at a position corresponding to these rail portions. Here, it is assumed that each plate guide 35 is provided with a ball bearing 36 at a predetermined position on the outer surface thereof as in the first embodiment. The fuel cell 10 including the rail portion 82 and the plate guide 35 having such an arrangement
In A, the same effect as the fuel cell 10 of the first embodiment can be obtained. Further, in the fuel cell 10A, the rail 8
By forming 2 on one side surface and the upper surface, the unit cell 12 (or module) can be accommodated in the stack storage hole along the other side surface and the lower surface during stacking. Therefore, the accuracy at the time of stacking the stack can be ensured without providing the alignment portions 83A and 83B as in the first embodiment.

In the fuel cell 10 and the fuel cell 10A of the first embodiment, since the plate guide 35 has the ball bearing 36 at a predetermined position on the outer surface thereof, when the pressure plate 34 is stored in the stack storage hole. Therefore, the operation of housing the pressure plate 34 in the stack housing hole can be smoothly performed. Here, if the resistance at the time of storing the pressure plate 34 can be reduced, a configuration other than the ball bearing 36 may be provided in the plate guide 35.

For example, it is preferable to provide a roller instead of the ball bearing 36 at a predetermined position on the outer surface of the plate guide 35. Ball bearing 3
When the roller 6 is used, the contact portion with the side surface forming the rail portion 82 is a point, but when a roller is used, the contact portion with the side surface is a line. Therefore, the pressure applied from the stack side to the case side surface is dispersed as compared with the point, which is preferable. Further, instead of providing a structure such as the ball bearing 36 or the roller in the plate guide 35, a lubricant (for example, grease) capable of reducing frictional force and having no conductivity is applied between the plate guide 35 and the stack housing hole. It may be applied to the contact surface.

In the first embodiment, the plate guide 35 provided in the pressure plate 34 has a shape formed by combining square pillars, and the rail portion 82 provided in the cases 80A and 80B has the above-mentioned two parallel elongated plate-like structures. Although the plate guide 35 and the rail portion 82 are formed so as to be able to engage with the quadrangular columnar plate guide 35, the plate guide 35 and the rail portion 82 may have different shapes. For example, the plate guide may be formed in a substantially triangular prism shape, the bottom side of the triangular prism may be embedded in a pressure plate, the rail portion may be formed in a substantially wedge shape, and the triangular prism plate guide may be formed. It suffices if the pressure plate can be guided to maintain the pressure plate perpendicular to the stack stacking surface.

In the above-described embodiment, the rail 82 for guiding the plate guide 35 is provided inside the stack accommodating hole. However, the engaging portion formed in the plate guide so as to protrude into a predetermined shape is connected to the case. It may be configured to be guided by a cut portion provided on the wall surface of the first embodiment. Such a configuration is described below as a second embodiment.

FIG. 13 is an explanatory view showing the structure of a mechanism for maintaining the parallelism of the pressure plate 34B in the fuel cell 10B of the second embodiment. Fuel cell 1 of second embodiment
OB is the same as that of the fuel cell 10 of the first embodiment except for the structure for keeping the parallelism of the pressure plate constant in the stack storage hole. FIG. 13 shows one of four stack storage holes (here, stack storage hole 8
1A), a pressure plate 34B adjacent to the insulating plate 33 at the end of the stack 11A that has already been stacked.
Is stored.

The pressure plate 34B provided in the fuel cell 10B of the second embodiment has two plate guides 35B on two opposing sides, similarly to the first embodiment. These plate guides 35B form grooves 37 of a constant and predetermined depth formed in parallel with the stacking direction on the upper and lower surfaces of the region protruding from the outer peripheral portion of the pressure plate 34B (FIG. 13). reference). The groove 37 is formed over the entire length of the plate guide 35B in the longitudinal direction (stacking direction of the stack).

In the case 80A, slits 85 are formed at positions corresponding to the plate guides 35B on two side surfaces corresponding to the two opposite sides of the pressure plate 34B where the plate guides 35B are formed. The slit 85 has a cut structure having a predetermined length formed in parallel with the stacking direction of the stack from the end of the case 80A on the connection side with the pressing mechanism 110. The predetermined length is a length that allows the entire length of the plate guide 35B to be sufficiently engaged when the pressure plate 34B is housed in the stack storage hole and is adjacent to the insulating plate 33.

The slit 85 provided in the fuel cell 10B of the second embodiment guides the plate guide 35B when the pressure plate 34B is housed in the case 80A, similarly to the rail portion 82 of the first embodiment, and guides the pressure plate 34B. 34B is maintained perpendicular to the stacking direction of the stack. Press the pressure plate 34B to the stack storage hole 81
When the plate guide 35B is housed in the slot A, the ends of the grooves 37 formed on the upper and lower surfaces of each plate guide 35B are engaged with the ends of the slits 85 corresponding to the respective plate guides 35B. The pressure plate 34B is pushed into the stack accommodation hole 81A while being fitted into the hole 85. In this embodiment, in order to smoothly perform the operation of storing the pressure plate 34B into the stack storage hole 81A, in the present embodiment, the inside of the groove 37 (the engagement portion with the slit 85) or the peripheral portion of the slit 85 provided in the plate guide 35 is provided. , A predetermined lubricant (such as grease) is applied. FIG. 13 shows a state in which the pressure plate 34B is stored in the stack storage hole 81A, but the remaining stack storage holes 81B to 81B are shown.
The same applies to the operation of placing the pressure plate 34B at the end of the stacked stack in D.

The plate guide 3 configured as described above
According to the fuel cell 10B including the fuel cell 5B and the slit 85, the same effect as the fuel cell 10 of the first embodiment can be obtained. That is, since the plate guide 35B having the groove 37 is guided to the slit 85 formed in the case 80A, the pressure plate 34B is maintained in a state perpendicular to the stacking direction during assembly and operation of the fuel cell 10B. Therefore, the fuel cell 10B
There is no increase in the internal contact resistance or impairment of the gas sealing property.

In the second embodiment, in order to reduce the resistance when the pressure plate 34B is housed in the stack housing hole 81A, a lubricant is applied to the periphery of the groove 37 or the slit 85. The resistance may be reduced by another configuration such as using a ball bearing or a roller as in the embodiment. When ball bearings and rollers are used, these ball bearings and rollers are provided on the inner wall of the groove 37 (the surface that engages with the slit 85).

In the second embodiment, the slit 85 is formed to have a predetermined length from the end of the case. However, when the pressure plate 34B is laminated, the plate guide 3
5B may be formed in any length as long as it can be fully engaged. For example, cases 80A, 8
The slit 85 may be formed over the entire length of 0B. In this case, each of the cases 80A and 80B includes a plurality of members divided by the slits 85.

In the second embodiment, a groove parallel to the side surface of the case 80A is formed on the plate guide 35B side as a structure for engaging with the slit 85 on the case 80A side. If it is possible to maintain the parallelism of the pressure plate 34B by engaging with the cut notch structure, the plate guide 3 may have a different shape.
It may be provided on the 5B side.

Further, the structure provided on the case side to guide the pressure plate in a state perpendicular to the stack laminating surface may be a structure other than the above-described cut portion such as a slit or a groove structure. FIG. 14 shows an example of the third embodiment.
Shown in Case 8 provided in fuel cell 10C of the third embodiment
0A and 80B have two rail portions 86 on each side surface on the inner wall surface of the opposite side surface similar to the rail portion 82 formed in the first embodiment. The rail portion 82 of the first embodiment is formed as a groove structure by two parallel elongated plate-like structures provided perpendicular to the wall surface. And is formed by one elongated plate-like structure provided vertically.

Further, similarly to the first embodiment, the pressure plate 34C of the second embodiment has two plate guides 35C on two opposite sides parallel to the side surface of the fuel cell.
It has. The plate guide 35C has a groove 38 on the outer surface that is in contact with the inner wall surface of the stack storage hole. The groove portion 38 has a groove structure formed parallel to the stacking direction of the stack over the entire length of the plate guide 35C. When assembling the fuel cell 10C, the case 8 is provided at the end of the groove 38 provided in the plate guide 35C.
0A and 80B are fitted with the ends of the rails 86, and the pressure plates 34C are engaged with each other.
Into the stack storage hole.

Here, similarly to the above-described embodiment, the groove 3
If a configuration for reducing the resistance between the rail 8 and the rail portion 86 is provided, the work of fitting the pressure plate 34C can be performed more smoothly. For example, a predetermined lubricant is applied to the contact surface between the groove 38 and the rail 86, or the groove 38 is formed on the plate guide 35C.
A ball bearing or a roller may be provided on the inner surface side (on the contact surface with the rail portion 86). Of course,
The surface on which the groove 38 and the rail 86 are provided is the same as that of the fuel cell 10C.
The present invention is not limited to the two opposing surfaces corresponding to the side surfaces, but may be provided on other surfaces.

In the fuel cells of the first to third embodiments described above, the fuel supply / discharge unit 40 is formed of aluminum, and the insulating plate 33 is provided between the fuel supply / discharge unit 40 and the current collecting plate 32. However, it is sufficient that the stack and the fuel supply / discharge unit 40 be insulated. For example, if the fuel supply / discharge unit 40 is formed of an insulating member such as a resin, the insulating plate 33 is provided. The fuel supply / discharge unit 40 and the current collecting plate 32 can be adjacent to each other without the need. The same applies to the end of each stack on the pressure plate side, as long as the stack and the pressure plate are insulated from each other.For example, if the surface of the pressure plate is covered with an insulating member, the insulation can be achieved. The pressure plate and the current collecting plate 32 can be adjacent to each other without providing the plate 33. Further, it is sufficient that the respective stacks and the case are similarly insulated. If the case is formed of an insulating member such as a resin having sufficient strength, it is not necessary to perform an insulation treatment on the inner wall of the case. Further, in the above-described embodiment, a current collector plate further provided with terminals is stacked outside the end separator in order to connect the respective stacks. By directly connecting the separators, a configuration without such a current collecting plate may be adopted.

In the fuel cell according to the above-described embodiment, the four stacks 11A to 11D are housed in the case and connected via the fuel supply / discharge unit 40 to integrate the stacks. The present invention can be applied to a configuration in which the number of stacks to be stored is other than four as long as the number of stacks to be stored is not four. Hereinafter, as an example, a configuration in which the plate guide 35 and the rail portion 82 of the first embodiment are applied to a fuel cell including one stack will be described as a fourth embodiment.

FIG. 15 is an explanatory view showing an overview of a fuel cell 10D according to a fourth embodiment, and FIG.
It is an end elevation showing the state of a line section. Fuel cell 10D
Accommodates one stack 11 inside the case 80. Here, the fuel cell 10D includes a pressurizing mechanism 110 similar to the embodiment described above at one end, and the other end includes:
The fuel supply / discharge unit 40D includes a pressure receiving unit 87 adjacent to the fuel supply / discharge unit 40D. All of these components are housed in a case 80. The pressure receiving portion 87 is
It has substantially the same shape as the contact surface between the pressure member 130 and the pressure plate 34 provided in the pressure mechanism 110,
Prevents the generation of undesired bending and shearing force inside the fuel cell. At a predetermined position of the case 80, a hole structure of a predetermined size is provided at a position corresponding to a supply / discharge port of the cooling water, fuel gas, and oxidizing gas provided in the fuel / supply / discharge unit 40D. The fuel supply / discharge unit 40D can be connected to an external cooling water supply / discharge device, a fuel gas supply / discharge device, and an oxidizing gas supply / discharge device.

The fuel cell 10D according to the fourth embodiment having the above-described structure includes the pressure plate 34 having the plate guide 35 and the rail portion 82 as described above. Also, when the pressure plate 34 tilts during operation, the contact resistance inside the fuel cell does not increase and the gas sealing performance is not impaired. Of course, a mechanism for maintaining the parallelism of the pressure plate used in the other embodiment may be provided instead of the plate guide 35 and the rail portion 82 of the first embodiment. Further, in the fuel cell 10D of the fourth embodiment, the pressurizing mechanism 110 is provided only at one end, but the pressurizing mechanism 110 may be provided at both ends to pressurize from both sides.

When one fuel cell is formed by storing one stack in a case, the fuel supply / discharge unit 40 may not be provided. Also in such a case, by forming the same configuration as the rail portion 82 on the inner wall surface of the case and arranging the same configuration as the pressure plate 34 including the plate guide 35 at the end on the pressing device side, It is possible to keep the stacking surface of the pressure plate perpendicular to the stacking direction of the stack. Here, when the fuel cell does not include the fuel supply / discharge unit 40, the opening connectable to the external fuel supply / discharge device, the oxidizing gas supply / discharge device, and the cooling water supply / discharge device is provided at the end of the case. The fuel gas, the oxidizing gas, and the cooling water are supplied and discharged to a predetermined flow path formed in the fuel cell through the opening.

In the above, the case where the number of stacks provided in the fuel cell is four or one has been described, but other numbers may be used as a matter of course. The stack includes two stacks, and the fuel supply / discharge unit is sandwiched between the two stacks, or the fuel supply / discharge unit is sandwiched by an even number of stacks such as six or eight,
A configuration such as a configuration in which a fuel supply / discharge section is supported from multiple directions by three or more odd-numbered stacks is possible. Alternatively, a plurality of stacks may be individually connected by piping without using a fuel supply / discharge unit, and the present invention can be applied as long as each stack is housed in a case.

In the above-described embodiment, the pressing member 130, the pressing bolt 140, the rotation preventing member 120, the mounting plate 11
Although the stack is pressurized by the pressurizing mechanism 110 composed of two or the like, if the stack can be held in the case while a pressing force parallel to the stacking direction is applied to the stack. For example, a pressing mechanism having another configuration may be used. Also in this case, in the end structure of the stack pressurized by the pressurizing device, a guide portion corresponding to the plate guide included in the pressure plate of the above-described embodiment is provided, and in the case of storing the stack, the above-described case is described. If a guide mechanism corresponding to the rail portion or the slit of the embodiment is provided, the stacking surface of the end member of the stack can be maintained in a state perpendicular to the stacking direction of the stack, and the same effect as the above embodiment can be obtained. be able to.

The embodiments of the present invention have been described above.
The present invention is not limited to such embodiments at all, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an overview of a fuel cell 10 according to a preferred embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an outline of an internal configuration of the fuel cell 10;

FIG. 3 is an explanatory view illustrating the configuration of a single cell 12;

FIG. 4 is a perspective view schematically illustrating members constituting the single cell 12. FIG.

FIG. 5 is an explanatory diagram illustrating an overview of a fuel supply / discharge unit 40.

FIG. 6 is a cross-sectional view of the fuel cell 10 taken along line EE.

FIG. 7 shows a stack storage hole 81A stacked up to the insulating plate 33;
FIG. 7 is an explanatory diagram showing a state in which a pressure plate 34 is further stacked therein.

FIG. 8 is a sectional view taken along line FF of the fuel cell 10;

FIG. 9 is a cross-sectional view illustrating the configuration of the pressing mechanism 110.

FIG. 10 is an explanatory view schematically illustrating a rotation preventing member 120;

FIG. 11 is an explanatory view schematically illustrating a pressing member 130;

FIG. 12 is a sectional view schematically showing a configuration of a fuel cell 10A.

FIG. 13 shows a stack storage hole 8 in a fuel cell 10B.
It is explanatory drawing showing a mode that the pressure plate 34B is laminated | stacked in 1A.

FIG. 14 is a sectional view schematically showing a configuration of a fuel cell 10C.

FIG. 15 is an explanatory diagram illustrating an overview of a fuel cell 10D according to a fourth embodiment.

FIG. 16 is an end view showing a cross section taken along line HH of the fuel cell 10D.

[Explanation of symbols]

 10, 10A to 10D fuel cell 11, 11A to 11D stack 12 single cell 13 electrolyte membrane 14 anode 15 cathode 16, 17 separator 16P fuel gas channel 17P oxidizing gas channel 18, 19 End separator 20 ... Center separator 21 ... Cooling separator 22,23 ... Cooling water hole 24,25 ... Oxidizing gas hole 26,27 ... Fuel gas hole 28,29 ... Rib 30 ... Groove 31P ... Cooling water passage 32,32A ... Plates 33, 33A: Insulating plates 34, 34B, 34C: Pressure plates 35, 35B, 35C: Plate guides 36: Ball bearings 37, 38: Grooves 40, 40D: Fuel supply / discharge units 42A to 42D: Cooling water supply port 44A -44D: Cooling water supply connection port 46A-46D: Cooling water discharge port 48A-48D: Cooling water discharge connection port 50: fuel gas supply port 59: fuel gas discharge port 62A-62D: fuel gas supply connection port 64A-64D: fuel gas discharge connection port 70: oxidizing gas distribution groove 71A-71D: oxidizing gas supply port 72A-72D: oxidizing gas Supply connection ports 74A to 74D: Oxidizing gas discharge connecting ports 76A to 76D: Oxidizing gas discharge ports 78: Oxidizing gas discharge sections 80, 80A, 80B: Cases 81A to 81D: Stack storage holes 82: Rail sections 83A, 83B: Positioning Part 84: Strengthening part 85: Slit 86: Rail part 87: Pressure receiving part 110: Pressing mechanism 112: Mounting plate 114: Through hole 120: Rotation preventing member 122: Pedestal part 124: Fitting part 126: Through hole 130 ... Pressing member 132 ... Disc 134 ... Pressing rib 136 ... Pressing shaft 138 ... Pressing recess 140 ... Pressing bolt 142 ... End 144 ... threaded portion 146 ... end

Claims (5)

[Claims] 1. A fuel cell in which a fuel cell stack formed by stacking unit cells is accommodated in a case, and the fuel cell stack is pressed and held by a pressing member from at least one end side. The parallelism maintaining the parallelism of the pressing surface by the pressing member so that the direction of the pressing force applied from the pressing member to the end of the fuel cell stack is parallel to the stacking direction of the fuel cell stack. A fuel cell having a maintenance mechanism. 2. The fuel cell according to claim 1, wherein the parallel maintaining mechanism is stacked on an end of the fuel cell stack, and applies a pressing force applied to an end of the fuel cell stack to the fuel. In the end member to be transmitted to the cell stack, a guide portion formed in a predetermined shape, and provided in the case, when the fuel cell stack receives a pressing force, the guide portion provided in the end member And a guide mechanism for guiding and keeping the end member perpendicular to the stacking direction of the fuel cell stack. 3. The guide mechanism is a rail portion that engages with the guide portion provided on an end member of the fuel cell stack and guides the end member of the fuel cell stack. The fuel cell according to claim 2, wherein the fuel cell stack is formed on a wall surface of the fuel cell stack in parallel to a stacking direction of the fuel cell stack. 4. The fuel cell according to claim 2, wherein the guide portion provided on an end member of the fuel cell stack has an engaging portion projecting in a predetermined shape, and the guide mechanism is provided. Is a cut portion formed in the case in parallel to the stacking direction of the fuel cell stack, and engaged with the engaging portion of the guide portion to guide an end member of the fuel cell stack. . 5. A fuel cell stack according to claim 2, further comprising: a frictional force reducing unit configured to reduce a frictional force generated between the guide unit and the guide mechanism provided on an end member of the fuel cell stack.
The fuel cell as described.