JP5284041B2 - Fuel cell - Google Patents

Description

  The present invention relates to a technique for preventing a current collector plate from being damaged in a fuel cell by improving a connection portion of a current cable in the fuel cell.

  Conventional fuel cells generally use a screw hole installed in the current collector plate as a means for connecting the current collector plate and the current cable, and screw the current cable to the current collector plate. There is known a method in which a protruding portion is provided at a portion to connect a current cable. However, the current collector plate is made of a metal material with excellent electrical conductivity and high mechanical strength. However, if the current collector plate is made of a metal plate, it may cause elution of metal ions or corrosion of the metal part. Battery performance may be reduced. For this reason, means for providing a seal portion so that the fuel gas, oxidant gas or cooling water supplied to each single cell of the fuel cell stack does not contact the metal current collector plate has been proposed (Patent Document 1, 2).

JP 2007-179992 A JP-A-2005-44527

  However, in the configuration in which the current collector plate is made of a metal plate and the seal portion is installed so that the fuel gas, the oxidant gas, or the cooling water does not come into contact with the metal, the fuel gas, the oxidant gas, or the There is a problem that the cooling water partially contacts the metal current collector plate, or the metal current collector plate is corroded due to the influence of moisture in the atmosphere.

  Therefore, it is desired to use a non-metallic material such as a carbon plate or graphite plate excellent in corrosion resistance and electric conductivity, or a molded product mainly composed of carbon or graphite as the material of the current collector plate. Even when the current collector plate is made of a conductive material other than metal, as shown in FIG. 7, the current cable is collected by using screw holes installed in the current collector plate as means for connecting the current collector plate and the current cable. Means are provided for screwing the electrical plate.

  That is, in FIG. 7, reference numeral 1 is a fuel cell stack, 2 is a conductive current collecting plate, 3 is an electrically insulating fastening plate, and 4 is a fastening plate 3 in a direction close to each other. It is a tie rod. Reference numeral 6 denotes an opening formed so that the current collector plate 2 provided on the fastening plate 3 is exposed to the outside, 9 is a current cable, 10 is a connection terminal 10 of the current cable, and 12 is a current. A cable fixing screw for fixing the cable 9 to the current collector plate 2.

  The fastening plate 3 is made of an electrically insulating material. However, when the fastening plate 3 is made of a conductive material, the current collecting plate 2 and the fastening plate are used to prevent the electromotive portion from being exposed. It is desirable to insert an insulator between 3. The fastening plate 3 is provided with an opening 6 formed so that the current collector plate 2 is exposed to the outside. The current collector plate 2 is provided with screw holes, and cable fixing screws 12 are screwed into the screw holes. A connection terminal 10 is fixed to the tip of the current cable 9, and the connection terminal 10 is fixed to the current collector plate 2 by a cable fixing screw 12.

  However, when the current collector plate 2 is made of a non-metallic material such as a carbon plate, a graphite plate, or a molded product mainly composed of carbon or graphite, these materials generally have a tensile direction compared to the strength in the compression direction. The strength in the bending direction is weak. Therefore, as in the prior art, a screw hole installed in the current collector plate is used to screw the current cable to the current collector plate, or a protruding portion is provided on a part of the current collector plate to connect the current cable. In the means, there is a problem that the current collector plate is easily damaged by an external force in a pulling direction or a bending direction generated at a connection portion between the current cable and the current collector plate.

  The present invention has been proposed in order to solve the above-described problems of the prior art, and the object thereof is to have a structure in which the current collector plate is not easily damaged at the connection between the current collector plate and the current cable. It is to provide a fuel cell.

In order to achieve the above object, a fuel cell of the present invention comprises a fuel cell stack formed by stacking a plurality of unit cells, and a conductive current collector plate installed at both ends of the fuel cell stack. A fuel cell comprising: a clamping plate that clamps and holds the fuel cell stack and the current collector plate in directions approaching each other; and a current cable connected to the current collector plate. A fixing member is disposed between the attachment plate and the current collector plate, and a connection portion of the current cable tip is disposed between the fixing member and the current collector plate. The connecting portion is pressed against the surface of the current collector plate, the current cable and the current collector plate are fixed, and the fixing member is a fixing screw installed on the clamping plate, and the fixing screw is tightened. By the current cable Connection of the tip is pressed against the current collector plate, and the current cable and the collector plate is characterized in that it is fixed.

  Another aspect of the present invention is characterized in that the connection portion at the tip of the current cable is a terminal fixed to the connection portion at the tip of the current cable or a connection fitting to which the terminal is fixed.

  According to the present invention having the above-described configuration, the current cable and the current collector plate are fixed by pressing the connecting portion at the tip of the current cable against the current collector plate by the fixing member. Since only an external force in the compression direction is applied, the current collector plate can be prevented from being damaged. Further, the current cable can be easily attached to and detached from the fuel cell main body, and a highly reliable fuel cell with excellent assemblability can be provided.

  Embodiments of a fuel cell according to the present invention will be described below with reference to the drawings. Here, in each embodiment, the same code | symbol is attached | subjected to the same or similar component, and the overlapping description is abbreviate | omitted.

[First Embodiment]
[Constitution]
First, the configuration of the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing a first embodiment according to the present invention, and FIG. 2 is a sectional view thereof.

  In FIG. 1, reference numeral 1 denotes a fuel cell stack, in which an anode electrode and a cathode electrode are arranged on both sides of the electrolyte. A plurality of unit cells each including a separator having a fuel gas flow path, an oxidant gas flow path, and a cooling water flow path are disposed in contact with the anode electrode and the cathode electrode, respectively.

  At both ends of the fuel cell stack 1, a conductive current collecting plate 2, an electrically insulating fastening plate 3 installed at both ends of the current collecting plate 2, and the fastening plate 3 are arranged in directions close to each other. Tightening tie rods 4 are installed. The fastening plate 3 is made of an electrically insulating material. However, when the fastening plate 3 is made of a conductive material, the current collecting plate 2 and the fastening plate are used to prevent the electromotive portion from being exposed. It is desirable to insert an insulator between 3.

  A gas manifold 5 is installed on the side surface of the fuel cell stack 1. The gas manifold 5 is a box-shaped structure having an opening on the surface facing the fuel cell stack 1, and includes a fuel gas flow path, an oxidant gas flow path, a cooling water flow path, and a separator of each unit cell. A gas chamber and a cooling water chamber for supplying fuel, an oxidant, and cooling water are configured.

  Further, as shown in FIG. 2, the fastening plate 3 is provided with an opening 6 formed so that the current collector plate 2 is exposed to the outside, and a screw hole 7 installed facing the opening 6. The fixing screw 8 of the current cable is screwed into the screw hole 7. A connection terminal 10 is fixed to the tip of the current cable 9, and the connection terminal 10 is sandwiched between the tip of the fixing screw 8 and the surface of the current collector plate 2.

  The operation of the first embodiment having the above configuration will be described. In the first embodiment, the connection terminal 10 is pressed against the surface of the current collector plate 2 by tightening the fixing screw 8. By this pressing force, the connection terminal 10 and the current collector plate 2 are fixed, and conduction between the two is ensured. As a result, only the external force in the compression direction is applied to the current collector plate 2.

  Moreover, since the strength tightened with the fixing screw 8 can be adjusted, the connection terminal 10 can be fixed with an appropriate pressing force. Further, by loosening the fixing screw 8, the current cable 9 can be easily attached to and detached from the fuel cell main body.

  As described above, in the first embodiment, only the external force in the compression direction acts on the current collector plate 2, so that the current collector plate 2 is a carbon plate, a graphite plate, or a molded product mainly composed of carbon or graphite. Even when the non-metallic material is used, the current collector plate 2 is not easily damaged. Further, the force for pressing the connection terminal 10 against the current collector plate 2 by the fixing screw 8 can be adjusted. Therefore, an increase in electrical resistance due to a decrease in contact resistance between the connection terminal 10 and the current collector plate 2 can be prevented. Furthermore, the current cable 9 can be easily attached to and detached from the fuel cell body, and a fuel cell excellent in assemblability can be provided.

[ Reference Example of First Embodiment]
The configuration of the reference example of the first embodiment will be described with reference to FIG. FIG. 3 is a sectional view of a fuel cell in a reference example of the first embodiment according to the present invention.

In the fuel cell of the reference example of the first embodiment, an opening 6 is formed in the clamping plate 3 such that the current collector plate 2 is exposed to the outside, and is sandwiched between the clamping plate 3 and the connection terminal 10. Thus, the fixed spring 11 is installed, and the connection terminal 10 is sandwiched between the fixed spring 11 and the current collector plate 2. Here, the fixed spring 11 is a leaf spring formed by bending spring steel, and is installed in a deformed state so as to press the connection terminal 10 against the current collector plate 2 by the restoring force of the spring.

The operation of the reference example of the first embodiment having the above-described configuration will be described. In the reference example of the first embodiment, the connection terminal 10 is pressed against the current collector plate 2 by the restoring force of the fixing spring 11 made of an elastic body, and the connection terminal 10 and the current collector plate 2 are fixed and both of them are fixed. Continuity is ensured. As a result, as in the first embodiment, even in the configuration of the reference example of the first embodiment, only the external force in the compression direction is applied to the current collector plate 2.

  Further, since the current cable 9 is pressed against the current collector plate 2 by the restoring force of the elastic deformation of the fixing spring 11, the holding force is not loosened as compared with the case where it is fixed with screws. Further, the current cable 9 can be easily attached to and detached from the fuel cell main body by removing the fixing spring 11 or pulling out the connection terminal 10 sandwiched between the fixing spring 11 and the current collector plate 2.

As described above, in the reference example of the first embodiment, as in the first embodiment, since the acts only external force in the compressing direction is the current collector plate 2, carbon plate or graphite plate current collecting plate 2 Alternatively, the current collector plate 2 is not easily damaged even when it is made of a non-metallic material such as a molded product mainly composed of carbon or graphite. In addition, since the restoring force of the elastic deformation of the fixed spring 11 is used, the holding force for a long period can be maintained. Therefore, it is possible to prevent an increase in electrical resistance due to a decrease in contact resistance between the connection terminal 10 and the current collector plate 2 during long-term operation of the fuel cell. Furthermore, the current cable 9 can be easily attached to and detached from the fuel cell body, and a fuel cell excellent in assemblability can be provided.

Second Embodiment
The configuration of the second embodiment will be described with reference to FIG. The second embodiment is the first embodiment combines the reference example of the first embodiment, the pressing force and the restoring force from the connecting terminal 10 to the current collector plate 2 fixed spring 11 of the fixing screw 8 It is fixed to the surface. FIG. 4 is a cross-sectional view of a fuel cell according to the second embodiment of the present invention.

In the second embodiment, the fastening plate 3 is provided with an opening 6 formed so that the current collector plate 2 is exposed to the outside and a screw hole 7 installed facing the opening, A fixing screw 8 is screwed into the screw hole 7. Further, a connection terminal 10 is installed at the tip of the current cable 9, and a fixing spring 11 is installed between the fixing screw 8 and the connection terminal 10. That is, the connection terminal 10 is sandwiched between the fixed spring 11 and the current collector plate 2.

The operation of the second embodiment having the above configuration will be described. In the second embodiment, the fixing screw 8 adjusts the space between the fixing screw 8 and the current collector plate 2, and the fixing spring 12 is sandwiched between the spaces. The connection terminal 10 is pressed against the surface of the current collector plate 2 by the restoring force of the fixed spring 12 disposed in the space formed between the fixing screw 8 and the current collector plate 2. By this pressing force, the connection terminal 10 and the current collector plate 2 are fixed, and conduction between the two is ensured. As a result, as in the first embodiment and the reference example of the first embodiment, only the external force in the compression direction is applied to the current collector plate 2 even in the configuration of the second embodiment.

  In addition, since the connection terminal 10 is pressed against the current collector plate 2 by the restoring force of the elastic deformation of the fixed spring 11, the force of clamping for a long time does not loosen. Further, the current cable 9 can be easily attached to and detached from the fuel cell main body by removing the fixing spring 11 or pulling out the connection terminal 10 sandwiched between the fixing spring 11 and the current collector plate 2.

As described above, in the second embodiment, as in the first embodiment and the reference example of the first embodiment, only the external force in the compression direction acts mainly on the current collector plate 2. Even when the plate 2 is made of a non-metallic material such as a carbon plate, a graphite plate, or a molded product mainly composed of carbon or graphite, the current collector plate 2 is not easily damaged.

Moreover, the use of the both the fixing screw 8 fixed the spring 1 1, comprising a connection terminal 10 is easy to adjust the force of pressing the current collector plate 2. For example, an excessive force is not applied to the current collector plate 2 by screwing the fixing screw 8 too much. Further, the space between the fixing screw 8 and the current collector plate 2 can be freely adjusted by the fixing screw 8. Therefore, fixing the spring 1 1 is the size need not be applied resiliency between the opening 6 and the current collector plate 2. That is, the fixing spring 1 1, if a size falling between the opening 6 and the current collector plate 2, it is possible to use a spring of various sizes. Furthermore, even if the loose fixing screws 8, the connecting terminal 10 by the restoring force of the fixing spring 1 1 is possible to be sandwiched between the current collector plate 2. Therefore, it is possible to provide a highly reliable fuel cell in which the electric resistance between the current cable 9 and the current collector plate 2 does not increase even during long-term operation.

[Other Embodiments]
The embodiments described above are merely examples, and the present invention is not limited to these. Moreover, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

(A) The screw hole 7 of the fastening plate 3 in FIGS. 2 and 4 does not have to be a screw hole directly processed in the fastening plate 3. For example, a configuration in which a component having a screw hole is attached to the fastening plate 3 may be used. Further, the fixed spring 11 in FIGS. 3 and 4 can also be constituted by a compression coil or a block-like elastic body, not a leaf spring formed by bending spring steel.
(B) In the embodiment of the present invention, in FIGS. 2 to 4, the opening 6 is provided in the center of the fastening plate 3, and the connection terminal 10 is placed in the center of the current collector 2 by the fixing spring 11 or the fixing screw 8. It is fixed. However, the positions of the openings 6 and the places where the connection terminals 10 are fixed are examples and are not limited thereto. For example, the position of the opening 6 does not need to be the center of the fastening plate 3 and can be freely installed as long as the connection terminal 10 can be fixed to the current collector plate 2. Furthermore, the direction of the opening 6 does not have to be perpendicular to the current collector plate as shown in FIGS. 2 to 4 and can be provided parallel to the current collector plate 2 as shown in FIG. is there.

(C) In the above embodiment, the connection terminal 10 fixed to the current cable 9 is pressed against the current collector plate 2 by the fixing member in order to make the current cable 9 and the current collector plate 2 conductive. What is pressed against the current collector plate 2 by the fixing member may not be the connection terminal 10 fixed to the current cable 9. For example, as shown in FIG. 6, the connection fitting 13 can be pressed against the current collector plate 2. That is, in FIG. 6, the connection metal fitting 13 may be a metal L-shaped metal piece, and the connection terminal 10 fixed to the current cable 9 and the connection metal fitting 13 may be connected by screws, solder, or the like.

The perspective view of the whole fuel cell concerning a 1st embodiment. Sectional drawing of opening part 6 vicinity of the clamping board of the fuel cell concerning 1st Embodiment Sectional drawing of opening part 6 vicinity of the clamping board of the fuel cell concerning the reference example of 1st Embodiment Sectional drawing of opening part 6 vicinity of the clamping board of the fuel cell concerning 2nd Embodiment Sectional drawing of embodiment at the time of providing the opening part 6 of a clamping board in the side surface of the clamping board 3 Sectional drawing of embodiment in the case of fixing the connection terminal 10 to the member for connection Sectional view of the vicinity of the opening 6 of the conventional fuel cell clamping plate

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell laminated body 2 ... Current collecting plate 3 ... Clamping plate 4 ... Tie rod 5 ... Gas manifold 6 ... Clamping plate opening 7 ... Clamping plate screw hole 8 ... Fixing screw 9 ... Current cable 10 ... Connection Terminal 11 ... Fixing spring 12 ... Set screw

Claims (3)

A fuel cell stack formed by stacking a plurality of unit cells;
Conductive current collectors installed at both ends of the fuel cell stack;
A clamping plate that clamps and holds the fuel cell stack and the current collector plate in directions close to each other;
In a fuel cell comprising a current cable connected to the current collector plate,
A fixing member is disposed between the clamping plate or the clamping plate and the current collector plate,
A connecting portion at the tip of the current cable is disposed between the fixing member and the current collector plate,
By the fixing member, the connection portion at the tip of the current cable is pressed against the surface of the current collector plate to fix the current cable and the current collector plate ,
The fixing member is a fixing screw installed on the fastening plate;
By tightening the fixing screw, the connecting portion at the tip of the current cable is pressed against the current collector plate, and the current cable and the current collector plate are fixed . A fixing spring is provided adjacent to the tip of the fixing screw,
The current cable and the current collector plate are fixed by tightening the fixing screw and the connecting force at the tip of the current cable being pressed against the current collector plate by the elastic deformation restoring force of the fixing spring. The fuel cell according to claim 1. The connection portion at the tip of the current cable is
3. The fuel cell according to claim 1, wherein the fuel cell is a terminal fixed to a front end of the current cable or a connection fitting to which the terminal is fixed.

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