JP7076259B2 - Fuel cell system - Google Patents

Description

The present invention relates to a fuel cell system having a fuel cell stack and a casing for accommodating the fuel cell stack.

The fuel cell stack has a plurality of power generation cells stacked on each other and a set of terminal plates as current collectors arranged at each end of the power generation cells in the stacking direction. The anode electrode of each power generation cell is electrically connected to one terminal plate, and the cathode electrode of each power generation cell is electrically connected to the other terminal plate. Further, an external device such as an electrical unit is electrically connected to both terminal plates.

The electrical connection between the terminal plate and the external device is made via a conductor. For example, as shown in Patent Document 1, a tab portion is formed so as to protrude from the terminal plate (“current collector plate” in Patent Document 1), and a conductor is connected to the tab portion. Patent Document 2 proposes a power cable for use as this type of conductor. It is also conceivable to use a bus bar as shown in Patent Document 3.

Japanese Unexamined Patent Publication No. 2017-76574 Japanese Unexamined Patent Publication No. 2006-323229 Japanese Unexamined Patent Publication No. 11-67184

In the case of a fuel cell system in which the fuel cell stack is housed in the casing, in order to electrically connect the terminal plate and the external device arranged outside the casing, a passage hole is formed in the casing and the passage hole is provided. It is necessary to pass the conductor. This passage hole is formed in a preset location on the casing. In addition, connection terminals for external devices are also provided at preset positions. Therefore, when the conductor does not have a shape that passes through the passage hole and reaches the connection terminal, it is necessary to add another conductor or the like.

As described above, in the fuel cell system according to the prior art, the inconvenience that the degree of freedom of the contact position between the conductor and the terminal plate or the contact position between the conductor and the external device is small has become apparent.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a fuel cell system having an improved degree of freedom in contact position and excellent versatility for this purpose.

In order to achieve the above object , according to one embodiment of the present invention, there is a casing containing the fuel cell stack, and the terminal plate included in the fuel cell stack is arranged outside the casing. In a fuel cell system that is electrically connected to an external device via a conductor
A passage hole for passing the conductor is formed in the casing.
A fuel cell system in which the conductor is flexible and the passage holes are offset from the position of contact points between the conductor and the terminal plate along the stacking direction or gravity direction of the fuel cell stack. Is provided .

As described above, in the present invention, a conductor having flexibility is used. Therefore, even when the passage hole for passing the conductor is offset from the position of the contact point between the conductor and the terminal plate along the stacking direction of the fuel cell stack or the gravity direction (height direction). By deforming the cable according to the amount of offset, the cable can be easily passed through the through hole.

Therefore, the contact position between the conductor and the terminal plate or the position of the passage hole can be freely set. Therefore, the degree of freedom in design such as the number of stacked power generation cells and the dimensions of the casing is improved. In addition, since the fuel cell stack can be electrically connected to various external devices, it is excellent in versatility. The conductor is preferably one that can maintain its shape after being deformed by receiving an external force.

The terminal plate preferably has a tab portion having a bent portion at the tip thereof. In this case, a contact is provided on the tab portion. With this configuration, conductors can be passed through through holes at various positions. That is, the degree of freedom in design and versatility are further improved.

A preferable example of the conductor is a cable configured by laminating a plurality of conductive thin plates. This cable exhibits sufficient flexibility and retains its shape when deformed. Moreover, by increasing the number of conductive thin plates, it is possible to cope with a large current.

The conductor preferably has at least two bends. By deforming the conductor so that the two bent portions are formed in this way, it is possible to pass the conductor through the passing hole even if the passing hole is offset from the contact point.

It is preferable to fill the through hole through which the conductor is passed with a sealing member. In other words, a sealing member may be interposed between the passage hole and the conductor. This makes it possible to prevent foreign substances such as dust, dust, and liquid from entering the casing.

According to the present invention, as a conductor for electrically connecting a fuel cell stack and an external device, a conductor that is flexible and capable of maintaining its shape after being deformed by an external force is used. I have to. Such a conductor is when the passage hole formed in the casing for passing the conductor is offset from the contact point between the conductor and the terminal plate along the stacking direction or the height direction of the fuel cell stack. Even if there is, it is easy to deform it according to the offset amount, and therefore it is easy to pass it through the through hole.

For the above reasons, the contact position between the conductor and the terminal plate or the position of the passage hole can be freely set. Therefore, for example, the degree of freedom in design is improved with respect to the number of stacked power generation cells, the dimensions of the casing, and the like. Therefore, the fuel cell stack can be electrically connected to various external devices, which is excellent in versatility.

It is an overall schematic side view of the fuel cell system which concerns on 1st Embodiment of this invention. It is a schematic front view of the terminal plate constituting the fuel cell system of FIG. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 3 is an exploded explanatory view of a main part of a cable (conductor) constituting the fuel cell system of FIG. 1. It is an overall schematic side view of the fuel cell system which concerns on 2nd Embodiment of this invention. It is a Y arrow view of the fuel cell system shown in FIG.

Hereinafter, preferred embodiments of the fuel cell system according to the present invention will be given and will be described in detail with reference to the accompanying drawings. In the following, a so-called solid polymer fuel cell having an electrolyte membrane made of a solid polymer will be exemplified, but the present invention is not particularly limited to this, and is not limited to this, and is a phosphoric acid type, a solid oxide type, or a molten carbonate type. , Direct carbon type or the like may be used.

FIG. 1 is an overall schematic side view of the fuel cell system 10 according to the first embodiment. The fuel cell system 10 has a fuel cell stack 12 and a casing 14 for accommodating the fuel cell stack 12, and above the casing 14, an electrical unit 16 (external) to which power is supplied from the fuel cell stack 12. Equipment) is arranged.

The fuel cell stack 12 has a cell laminate 22 in which a plurality of power generation cells 20 in which an electrolyte membrane / electrode assembly is sandwiched between a set of separators are laminated. In this case, the electrolyte membrane / electrode assembly is configured by sandwiching an electrolyte membrane made of a solid polymer between an anode electrode and a cathode electrode. Such a configuration of the power generation cell 20 and the cell laminated body 22 is well known to those skilled in the art, and detailed description thereof will be omitted here. Note that FIG. 1 has a viewpoint in a direction orthogonal to the stacking direction of the power generation cells 20.

Further, the fuel cell stack 12 includes two terminal plates 24, two insulating plates 26, and two end plates 28 that function as current collectors for extracting generated electric power. The terminal plate 24, the insulating plate 26, and the end plate 28 are arranged at both ends of the cell laminate 22 in the stacking direction in this order from the inside to the outside.

FIG. 2 is a schematic front view of the terminal plate 24. The terminal plate 24 integrally has a substantially flat plate-shaped plate body 30 that abuts on the separator of the power generation cell 20, and a tab portion 32 that extends vertically upward from the upper side of the plate body 30. The upper tip of the tab portion 32 is located higher than the upper portion of the cell laminate 22 (see FIG. 1).

The terminal plate 24 can be manufactured by cutting out, for example, a metal plate having a certain thickness made of copper, aluminum, or the like so as to have the plate body 30 and the tab portion 32 integrally. Alternatively, the terminal plate 24 may be manufactured by cutting out the plate body 30 and the tab portion 32 from separate metal plates and joining them together. The lateral position of the tab portion 32 may be set according to the terminal position of the electrical unit 16.

The tab portion 32 is a terminal portion for connecting the cable 36 (conductor) shown in FIG. That is, a first connection hole 38 is formed through the upper tip of the tab portion 32 along the thickness direction thereof. On the other hand, a second connection hole 40 is formed at one end of the cable 36 so as to be overlapped with the first connection hole 38, and the first connection bolt 42 is passed through the first connection hole 38 and the second connection hole 40. By screwing the first nut 44 into the first connection bolt 42, a first contact 46 in which the terminal plate 24 (fuel cell stack 12) and the cable 36 are electrically joined is formed. A plurality of first connection bolts 42 and first nuts 44 may be used. Further, the first connecting bolt 42 and the first nut 44 may be replaced by joining by rivets, or may be joined by brazing, caulking, or crimping.

One terminal plate 24 is electrically connected to the anode electrode of each power generation cell. Further, the other terminal plate 24 is electrically connected to the cathode electrode of each power generation cell.

The casing 14 is configured by connecting the bottom wall member 50, the plurality of side wall members 52, and the top plate member 54. The top plate member 54 in this is formed with two through holes 56 for leading the cable 36 out of the casing 14. As shown in FIG. 3, the passage hole 56 is an elongated hole extending along the width direction (direction orthogonal to the paper surface) of the cell laminate 22, and the short side thereof is the tab portion 32 (the second). It is at a position offset inward or outward in the stacking direction of the cell laminated body 22 from the one contact 46). The passage hole 56 is filled with a sealing material 58 which is a solidified solid seal or a liquid seal. Therefore, the sealing material 58 is interposed between the cable 36 and the inner wall of the passage hole 56, and is connected to the inside of the casing 14. The outside is sealed.

A set of connection terminals 60 is provided on the end face of the electrical unit 16 parallel to the stacking direction of the cell laminated body 22. At least one of the connection terminals 60 is electrically connected to the tab portion 32 of one of the terminal plates 24. Specifically, a third connection hole 62 is formed at the other end of the cable 36 facing the connection terminal 60, and a fourth connection hole 64 is formed at the connection terminal 60 so as to be superimposed on the third connection hole 62. Will be done. The cable 36 and the electrical unit 16 are electrically joined by screwing the second nut 68 into the second connection bolt 66 passed through the third connection hole 62 and the fourth connection hole 64. The second contact 70 is formed. The terminal plate 24 (fuel cell stack 12) and the electrical unit 16 are electrically connected to each other via the cable 36 by the second contact 70 and the first contact 46. The second contact 70 may be formed by a connection structure other than the second connection bolt 66 and the second nut 68 as long as it is electrically contacted.

Of course, the remaining one connection terminal 60 is also electrically connected to the tab portion 32 of the other terminal plate 24 via the cable 36 in the same manner as described above.

The second contact 70 is formed, for example, substantially above the passage hole 56. Alternatively, the position may be slightly offset in the stacking direction of the cell laminated body 22 or in a direction orthogonal to the stacking direction.

In this case, as shown in FIG. 4, the cable 36 as a conductor covers a long flat plate, that is, a laminated body in which a plurality of strip-shaped thin metal plates 74 such as copper and aluminum are laminated, and the laminated body. It has an insulating coating 76. The cable 36 configured in this way is excellent in flexibility in the stacking direction and maintains its shape when deformed by an external force. Therefore, when the operator bends the cable 36 into a desired shape, the cable 36 keeps its shape until an external force is applied again.

As can be understood from the above, the first contact 46 between the tab portion 32 and the cable 36 is offset outward from the stacking direction of the cell laminate 22 with respect to the passage hole 56, while the cable 36 and the connection terminal. The second contact 70 with 60 is substantially above the passage hole 56. Therefore, the cable 36 is provided with a first bent portion 78 and a second bent portion 80 bent in the stacking direction of the metal thin plates 74, and as a result, the cable 36 has a substantially cubic function curve shape. ..

The fuel cell system 10 according to the first embodiment is basically configured as described above, and the effects thereof will be described next.

To configure the fuel cell system 10, the fuel cell stack 12 is housed in a casing 14 before connecting the top plate member 54. The cable 36 may be connected to the tab portion 32 in advance by screwing the first nut 44 into the first connection bolt 42 passed through the first connection hole 38 and the second connection hole 40. In other words, the first contact 46 is formed in advance.

Next, after temporarily assembling the top plate member 54 and confirming the position of the passage hole 56, the top plate member 54 is removed. Then, the cable 36 is deformed into a shape that allows it to pass through the passage hole 56. That is, the cable 36 is appropriately bent to provide the first bent portion 78 and the second bent portion 80. Since the cable 36 is highly flexible, this deformation is easy. Moreover, since the cable 36 maintains its deformed shape, the state in which the first bent portion 78 and the second bent portion 80 are provided is maintained.

Next, the top plate member 54 is assembled. At this time, the end of the cable 36 is exposed from the passage hole 56. Further, the passing hole 56 is filled with the sealing material 58 to close the passing hole 56. As a result, a seal is made between the inner wall of the passage hole 56 and the cable 36. The top plate member 54, the bottom wall member 50, and the plurality of side wall members 52 may be integrated in advance to form a tubular shape.

Further, the second nut 68 is screwed into the third connection hole 62 of the cable 36 and the fourth connection hole 64 of the connection terminal 60 through the second connection bolt 66. As a result, the second contact 70 is formed.

In this way, the fuel cell stack 12 is electrically connected to the electrical unit 16 via a cable 36 that exhibits flexibility and maintains its shape when deformed. Therefore, the cable 36 can be deformed or kept in shape according to the offset position of the passage hole 56. Therefore, it is not necessary to add another conductor to the cable 36 so as to pass through the passage hole 56.

Further, even when the position of the first contact 46 is different due to the change in the number of stacked power generation cells 20, or another top plate member 54 having a different position of the passage hole 56 is assembled, the above By deforming the cable 36 into an appropriate shape according to the above, the fuel cell stack 12 and the electrical unit 16 can be electrically connected.

That is, it is not necessary to set the position of the first contact 46 or the second contact 70 according to the shape of the cable 36. In other words, the degree of freedom in the positions of the first contact 46 and the second contact 70 is improved. Therefore, the fuel cell system 10 can be electrically connected to the electrical unit 16 of various dimensions or other external devices, and has excellent versatility.

Next, the fuel cell system 100 according to the second embodiment will be described with reference to FIG. 5, which is an overall schematic side view thereof, and FIG. 6, which is a Y arrow view in FIG. The components corresponding to the components shown in FIGS. 1 to 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

Each tab portion 104 of the two terminal plates 102 constituting the fuel cell system 100 has a vertical tab portion 106 extending in the vertical direction and the vertical tab portion 106 inward in the stacking direction of the cell laminate 22. It has a horizontal tab portion 108 that is bent approximately 90 ° toward it and extends in the horizontal direction. In this case, the first connection hole 38 is formed in the horizontal tab portion 108. The bending angle of the horizontal tab portion 108 is not particularly limited to 90 °.

As is understood with reference to FIGS. 5 and 6, in the second embodiment, the passage hole 56 is offset slightly above the upper surface of the horizontal tab portion 108 with respect to the side wall member 52 on the back side of the paper surface of FIG. Formed to be. Further, the electrical unit 16 is arranged at a position where the connection terminal 60 is substantially the same height as the passage hole 56.

That is, the first contact 46 between the horizontal tab portion 108 and the cable 36 is offset downward with respect to the passage hole 56, while the second contact 70 between the cable 36 and the connection terminal 60 is with the passage hole 56. It is about the same height. Therefore, the cable 36 has a substantially cubic function curve shape in which the first bent portion 78 and the second bent portion 80 are provided.

Of course, as in the first embodiment, the passage hole 56 may be formed in the top plate member 54, and the cable 36 may be passed through the passage hole 56. In this case as well, the first contact 46 may be provided in the horizontal tab portion 108, but it is also possible to form another connection hole in the vertical tab portion 106 and provide the first contact 46 through the connection hole. It is possible.

In this way, by providing the horizontal tab portion 108 which is a bent portion with respect to the vertical tab portion 106, the fuel cell stack 12 and the electrical unit 16 correspond to various casings 14 having different formation positions of the passage holes 56. (Or other external equipment) can be electrically connected. That is, the versatility is further improved.

The present invention is not particularly limited to the first and second embodiments described above, and various modifications can be made without departing from the gist of the present invention.

For example, in the first and second embodiments, the terminal plates 24 and 102 having the tab portions 32 and 104 protruding from the plate main body 30 are used, but the terminal plate made of only the plate main body 30 and the terminal plate are used. A separate tab member for current collection may be used. In this case, a recess is formed on one end surface of the insulating plate 26 to accommodate the terminal plate in the recess, a current collecting tab member is arranged on the other end surface, and the terminal plate and the current collecting tab member are attached to the insulating plate 26. All you have to do is screw it in. The screw electrically connects the terminal plate and the current collecting tab member.

Alternatively, a terminal plate having a current collecting protrusion on the end surface facing the insulating plate may be used. In this case, a through hole may be formed in the insulating plate and the end plate, and the current collecting protrusion may be passed through the through hole.

10, 100 ... Fuel cell system 12 ... Fuel cell stack 14 ... Casing 16 ... Electrical unit 24, 102 ... Terminal plate 30 ... Plate body 32, 104 ... Tab portion 36 ... Cable 46 ... First contact 56 ... Passing hole 58 ... Seal Material 60 ... Connection terminal 70 ... Second contact 74 ... Metal thin plate 78 ... First bent part 80 ... Second bent part 106 ... Vertical tab part 108 ... Horizontal tab part

Claims (5)

In a fuel cell system having a casing containing a fuel cell stack, the terminal plate included in the fuel cell stack is electrically connected via a conductor to an external device located outside the casing. ,
A passage hole for passing the conductor is formed in the casing.
The conductor is flexible and can maintain its shape after being deformed by receiving an external force until the external force is applied again , and the passage hole is formed between the conductor and the terminal plate. Is offset from the contact point along the stacking direction or the height direction of the fuel cell stack.
The conductor is a fuel cell system characterized in that the conductor is a cable configured by laminating a plurality of conductive thin plates . The fuel cell system according to claim 1, wherein the terminal plate has a tab portion having a bent portion at the tip thereof, and the contact is provided at the tab portion. In the fuel cell system according to claim 2 , the contact of the tab portion is arranged between the outer periphery of the fuel cell stack and the passage hole in a direction orthogonal to the stacking direction of the fuel cell stack. A fuel cell system characterized by this. The fuel cell system according to any one of claims 1 to 3, wherein the conductor has at least two bent portions. The fuel cell system according to any one of claims 1 to 4, wherein a sealing member is interposed between the passage hole and the conductor.

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