JP5444851B2 - Fuel cell separator - Google Patents

Description

  The present invention relates to a voltage monitoring terminal for each single cell of a fuel cell stack.

  In a fuel cell, for example, a polymer electrolyte fuel cell, a structure (stack structure) in which a plurality of single cells each having a membrane electrode assembly (MEA) and a separator are stacked is employed. In order to confirm the normality of power generation in each single cell of the fuel cell stack, a method is proposed in which a voltage monitoring terminal is provided in each single cell, a connector is connected to this voltage monitoring terminal, and the voltage is measured via the connector. (Patent Document 1).

JP 2005-216700 A

  The voltage monitoring terminal of each single cell is formed by protruding a part of one plate (metal plate) constituting the separator, so that the rigidity is low, and it is bent when the connector is attached or detached, There was a risk of short circuit.

  An object of the present invention is to improve the rigidity of a voltage monitoring terminal of each single cell of a fuel cell stack.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
[Mode 1] A separator for a fuel cell used for each single cell included in a fuel cell stack, each having a first protrusion formed at the same position, and a pair of opposing plates, and the pair At least one of the intermediate plate having a second protrusion formed between the first protrusion and the first protrusion, and the stacked first protrusion and second protrusion. A voltage monitoring terminal for measuring the voltage of the single cell, wherein the voltage monitoring terminal is arranged in the stacking direction of the first protrusion and the second protrusion. have a tip length along the shorter than about the position of the tip, the tip is tapered to two of the first protrusion of the pair of plates are formed by respective bent at a predetermined angle Having a shape, Fuel cell separator.

Application Example 1 A fuel cell separator used in each single cell included in a fuel cell stack, each having a first protrusion formed at the same position, and a pair of opposing plates, Formed by an intermediate plate having a second protrusion sandwiched between a pair of plates and formed at the same position as the first protrusion, and the stacked first protrusion and second protrusion And a voltage monitoring terminal for measuring the voltage of the single cell.

  In the fuel cell separator of Application Example 1, the voltage monitoring terminal is formed by the first projecting portion of the pair of stacked plates and the second projecting portion of the intermediate plate. Rigidity can be improved as compared with the configuration in which the voltage monitoring terminal is formed.

It is explanatory drawing which shows schematic structure of the fuel cell stack provided with the fuel cell (single cell) to which the separator of this invention is applied. It is sectional drawing which shows the AA cross section shown in FIG. It is explanatory drawing which shows the fuel cell stack 100 at the time of mounting | wearing with a cell monitor connector. 2 is a cross-sectional view showing a cross section AA in the fuel cell stack 100 to which the cell monitor connector 60 is attached. FIG. It is sectional drawing which shows the AA cross section of the fuel cell stack in a 2nd Example. It is the perspective view and front view which show the connector side terminal in a 3rd Example.

A. First embodiment:
FIG. 1 is an explanatory diagram showing a schematic configuration of a fuel cell stack including a fuel cell (single cell) to which the separator of the present invention is applied. The fuel cell stack 100 includes a plurality of stacked single cells 10, an oxidant gas supply manifold 11, an oxidant gas discharge manifold 12, a fuel gas supply manifold 13, a fuel gas discharge manifold 14, and a cooling medium supply manifold. 15 and a cooling medium discharge manifold 16. In the example of FIG. 1, the stacked portion of the single cells 10 in the fuel cell stack 100 is shown, and the other portions are omitted. In the example of FIG. 1, the vertically upward direction coincides with the + Z direction in a state where the fuel cell stack 100 is placed.

  Each single cell 10 includes a voltage monitoring terminal 80 for measuring the voltage of each single cell. In each unit cell 10, the voltage monitoring terminal 80 is arranged so as to be shifted from the position of the adjacent unit cell 10. With such a configuration, the distance d1 between the adjacent voltage monitoring terminals 80 is relatively large. Also, with such a configuration, a plurality of voltage monitoring terminals 80 are arranged in a staggered manner on the upper surface S1 of the fuel cell stack 100, and extend along the stacking direction of the single cells 10 (the direction along the Y axis). Two rows of voltage monitoring terminals 80 are formed. The detailed configuration of each single cell 10 will be described later.

  Each single cell 10 includes six through holes formed along the thickness direction. When the single cells 10 are stacked, the six manifolds 11 to 16 described above are fueled by the six through holes. It is formed inside the battery stack 100.

  The oxidant gas supply manifold 11 supplies air as an oxidant gas supplied from an air compressor (not shown) to each single cell 10. The oxidant gas discharge manifold 12 discharges excess air (cathode-side off gas) that has not been used in each single cell 10. The fuel gas supply manifold 13 supplies hydrogen gas as fuel gas supplied from a hydrogen gas tank (not shown) to each single cell 10. The fuel gas discharge manifold 14 discharges surplus hydrogen gas (anode-side off-gas) that has not been used in each single cell 10. The cooling medium supply manifold 15 supplies a cooling medium to each single cell 10. The cooling medium discharge manifold 16 discharges the cooling medium used in each single cell 10.

  FIG. 2 is a cross-sectional view showing the AA cross section shown in FIG. The AA cross section is a cross section along the row of one voltage monitoring terminal 80 formed on the upper surface S <b> 1 of the fuel cell stack 100. In the example of FIG. 2, only a part of the AA cross section is shown.

  The single cell 10 includes a seal-integrated MEA 20 and a separator 40. The seal-integrated MEA 20 includes a power generation unit 22 and a seal unit 21. The power generation unit 22 includes a membrane electrode assembly 25 and a porous body channel 26. The membrane electrode assembly 25 includes an electrolyte membrane (for example, Nafion (registered trademark), Flemion (registered trademark), etc.) of a fluororesin ion exchange membrane. The porous body channel 26 supplies the reaction gas (fuel gas and oxidant gas) to the membrane electrode assembly 25 and discharges the reaction gas from the membrane electrode assembly 25. Moreover, the porous body flow path 26 discharges the water generated with the power generation. For example, a foam metal or a metal mesh can be used as the porous body flow path 26.

  The separator 40 includes a cathode side plate 41, an anode side plate 43, and an intermediate plate 42, and the intermediate plate 42 is sandwiched between the cathode side plate 41 and the intermediate plate 42. Each of these three plates 41 to 43 is configured by forming a through hole in a thin metal plate such as stainless steel (SUS) or titanium. In the example of FIG. 2, the separator 40 having the voltage monitoring terminal 80 in the AA section (hereinafter referred to as “separator 40a”) and the separator 40 having no voltage monitoring terminal 80 in the AA section (hereinafter, referred to as “separator 40a”). "Referred to as" separator 40b ") are alternately arranged.

  The cathode side plate 41 includes an oxidant gas supply hole 45 and an oxidant gas discharge hole 46 in addition to the through holes forming the oxidant gas supply manifold 11. The oxidant gas supply hole 45 supplies the oxidant gas (air) supplied from the oxidant gas supply manifold 11 to the cathode side of the power generation unit 22. The oxidant gas discharge hole 46 discharges the cathode-side off-gas discharged from the power generation unit 22 to the oxidant gas discharge manifold 12.

  The anode side plate 43 is a through hole for supplying the fuel gas (hydrogen gas) supplied from the fuel gas supply manifold 13 to the anode side of the power generation unit 22 in addition to the through hole forming the oxidant gas supply manifold 11. (Not shown) and a through hole (not shown) for discharging the anode-side off-gas discharged from the power generation unit 22 to the fuel gas discharge manifold 14. In addition, these through-holes which the anode side plate 43 has do not appear in the AA cross section of FIG.

  The intermediate plate 42 has a number of through holes in addition to the through holes that form the oxidant gas supply manifold 11. As a space surrounded by these through holes, the cathode side plate 41 and the anode side plate 43, an oxidant gas supply channel 47, an oxidant gas discharge channel 48, and a plurality of cooling medium channels 49 are formed. Has been.

  The oxidant gas supply channel 47 supplies oxidant gas from the oxidant gas supply manifold 11 to the oxidant gas supply hole 45. The oxidant gas discharge channel 48 discharges oxidant gas from the oxidant gas discharge hole 46 to the oxidant gas discharge manifold 12. The cooling medium flow path 49 connects the cooling medium supply manifold 15 and the cooling medium discharge manifold 16 in each single cell 10.

  As shown in the separator 40a of FIG. 2, the voltage monitoring terminal 80 is formed such that a part of the separator 40 protrudes upward (+ Z direction). In other words, the voltage monitoring terminal 80 has a configuration in which projecting portions formed in the same shape at the same position in each of the plates 41 to 43 are stacked. Thus, since the voltage monitoring terminal 80 is formed by the three plates 41 to 43, it has high rigidity.

  FIG. 3 is an explanatory diagram showing the fuel cell stack 100 when the cell monitor connector is attached. The cell monitor connector 60 is detachably attached so as to cover the plurality of voltage monitoring terminals 80 of the fuel cell stack 100, and conducts the voltage monitoring terminal 80 and a voltage detector (not shown). In the example of FIG. 3, the cell monitor connector 60 is attached so as to cover the 14 voltage monitor terminals 80, but covers an arbitrary number of voltage monitor terminals 80 according to the size of the cell monitor connector 60. Can be attached.

  The cell monitor connector 60 includes a plurality of slots 61 and connector side terminals 62 arranged in each slot. Each slot is a groove formed corresponding to each separator 40 constituting the fuel cell stack 100. As shown in an enlarged view in FIG. 3, the connector-side terminal 62 is formed by bending a conductive thin plate member (for example, a metal plate) so that the cross-section has a substantially U-shape, and has a central support portion 62c. And two clamping parts 62a and 62b that are connected to the support part 62c and face each other. One connector side terminal 62 is arranged in each slot 61 of the cell monitor connector 60. When the cell monitor connector 60 is attached to the fuel cell stack 100, the two holding portions 62a and 62b sandwich the voltage monitoring terminals 80, and the support portion 62c contacts the end face of the voltage monitoring terminal 80.

  FIG. 4 is a cross-sectional view showing an AA cross section in the fuel cell stack 100 to which the cell monitor connector 60 is attached. FIG. 4 shows a cross section of the fuel cell stack 100 at the same position as FIG. As shown in FIG. 4, the separator 40 is inserted in each slot 61, and the three plates 41 to 43 are in contact with each connector side terminal 62. As described above, in the fuel cell stack 100, the protruding portions of the three plates 41 to 43 are inserted into the respective slots 61 and come into contact with the connector-side terminals 62, so that the voltage monitor when the cell monitor connector 60 is attached or detached. It is comprised so that it can suppress that the terminal 80 for bending is bent. Like the two separators 40a shown in FIG. 4, the distance d2 between the separators 40 adjacent to each other in the row of voltage monitoring terminals 80 is substantially equal to the distance between every other slot 61 and is relatively long. With such a configuration, the fuel cell stack 100 can suppress contact with the voltage monitoring terminals 80 located adjacent to each other even if the voltage monitoring terminals 80 are bent in the stacking direction. It is configured.

  As described above, the voltage monitoring terminal 80 of each single cell 10 has a high rigidity because the protruding portions formed in the same position on each plate 41 to 43 are laminated at the same position. Therefore, when the cell monitor connector 60 is attached or the cell monitor connector 60 is detached, the occurrence of damage such as breakage of the voltage monitor terminal 80 can be suppressed. Further, the voltage monitoring terminal 80 in each unit cell 10 is arranged so as to be shifted from the position of the adjacent unit cell 10. Therefore, the distance between the voltage monitoring terminals 80 of the adjacent single cells 10 can be made relatively long, and the distance between the voltage monitoring terminals 80 adjacent to each other in the same column can be made relatively long. Therefore, even if the voltage monitoring terminal 80 is bent, it is possible to suppress contact with another voltage monitoring terminal 80.

B. Second embodiment:
FIG. 5 is a cross-sectional view showing an AA cross section of the fuel cell stack in the second embodiment. FIG. 5 shows a cross section of the fuel cell stack at the same position as in FIG. The separator of the second embodiment is different from the separator 40 of the first embodiment in the shape of the voltage monitoring terminal, and the other configuration is the same as that of the first embodiment.

  The separator 40c of the second embodiment is provided with a voltage monitoring terminal 80a at the same position as the separator 40 of the first embodiment. In the voltage monitor terminal 80a, the tip 81 connected to the cell monitor connector 60 has a so-called tapered shape that becomes thinner toward the tip. Such a shape can be formed, for example, by bending the protruding portions forming the voltage monitoring terminals 80a of the cathode side plate 41 and the anode side plate 43, respectively, at a predetermined angle. The separator 40 c is configured so that the distal end portion 81 is easily inserted into the connector-side terminal 62 by forming the distal end portion 81 in a tapered shape.

  The distal end portion 81 includes an elastic layer 90 instead of the intermediate plate 42, and has a configuration in which the elastic layer 90 is sandwiched between the cathode side plate 41 and the anode side plate 43. The elastic layer 90 can be formed of an elastic body such as silicon rubber or butyl rubber, for example. The central layer of the tip 81 is formed by the elastic layer 90 because the thickness of the tip 81 can be reduced by the elasticity of the elastic layer 90 when the cell monitor connector 60 is attached to the fuel cell stack 100. This is because the distal end portion 81 can be easily inserted into the connector side terminal 62. In addition, after the cell monitor connector 60 is mounted on the fuel cell stack 100, the cathode side plate 41 and the anode side plate 43 can be pressed against the connector side terminals 62 (holding portions 62a and 62b) by the elasticity of the elastic layer 90. As a result, it is possible to improve conductivity and to prevent the cell monitor connector 60 from being detached from the fuel cell stack 100. The configuration of the portion closer to the center than the tip 81 (the lower portion in FIG. 5) of the voltage monitoring terminal 80a is the same as that of the voltage monitoring terminal 80 of the first embodiment.

  The separator 40a and the fuel cell stack 100a of the second embodiment having the above configuration have the same effects as the separator 40 and the fuel cell stack 100 of the first embodiment. In addition, since the tip 81 of the voltage monitor terminal 80a is tapered, the voltage monitor terminal 80a can be easily inserted into the connector side terminal 62. In addition, since the elastic layer 90 is disposed as an intermediate layer of the tip 81, the thickness of the tip 81 can be reduced by the elasticity of the elastic layer 90 when the cell monitor connector 60 is attached to the fuel cell stack 100. Therefore, the distal end portion 81 can be easily inserted into the connector side terminal 62. In addition, after the cell monitor connector 60 is mounted on the fuel cell stack 100, the cathode side plate 41 and the anode side plate 43 can be pressed against the connector side terminals 62 (holding portions 62a and 62b) by the elasticity of the elastic layer 90. Therefore, it is possible to improve electrical conductivity and to prevent the cell monitor connector 60 from being detached from the fuel cell stack 100.

C. Third embodiment:
FIG. 6A is a perspective view showing a connector side terminal in the third embodiment. FIG. 6B is a front view showing the connector-side terminal in the third embodiment. The separator of the third embodiment is different from the separator 40 of the first embodiment in the shape of the connector side terminal, and the other configuration is the same as that of the first embodiment.

  The connector side terminal 63 included in the separator of the third embodiment is formed by bending a conductive thin plate member (for example, a metal plate) in the same manner as the connector side terminal 62 of the first embodiment. The connector-side terminal 63 includes a support portion 62c and two sandwiching portions 62d and 62e that are connected to the support portion 62c and face each other. The shape of the support part 62c is the same as the support part 62c of the first embodiment. Unlike the clamping part 62a of the first embodiment, the clamping part 62d includes a bent part 62f that is bent so as to approach the opposing clamping part 62e. Similarly, the clamping part 62e includes a bent part 62g that is bent so as to approach the opposing clamping part 62d, unlike the clamping part 62b of the first embodiment. With such a configuration, the distance between the two clamping portions 62d and 62e is configured to be narrower than the other portions between the two bent portions 62f and 62g.

  Here, the connector-side terminal 63 is installed in each slot 61 so that the two bent portions 62 f and 62 g are located inside the wall surface of the slot 61. With such a configuration, when the connector side terminal 62 is inserted into the voltage monitoring terminal 80, the two bent portions 62 f and 62 g are pushed and expanded in the direction of the wall surface of the slot 61.

  The separator and fuel cell stack of the third embodiment having the above-described configuration have the same effects as the separator 40 and fuel cell stack 100 of the first embodiment. In addition, the connector-side terminal 63 of the third embodiment includes two bent portions 62f and 62g that are bent so as to approach each other. When the connector-side terminal 62 is inserted into the voltage monitoring terminal 80, two The bent portions 62f and 62g are configured to be expanded. Therefore, even if the thickness of the voltage monitoring terminal 80 (separator 40) varies in manufacturing, each voltage monitoring terminal 80 can be firmly held by the connector side terminal 63, and the conductivity can be improved.

D. Variations:
The present invention is not limited to the above-described examples and embodiments, and can be carried out in various modes without departing from the gist thereof. For example, the following modifications are possible.

D1. Modification 1:
In each embodiment, the voltage monitoring terminals 80 are arranged so as to be shifted from each other with respect to the adjacent single cells 10, and a plurality of voltage monitoring terminals 80 are arranged in a staggered manner. In the single cell 10, the voltage monitoring terminals 80 may be arranged at the same position, and all the voltage monitoring terminals 80 may be arranged in a line. Even in such a configuration, each voltage monitoring terminal 80 is formed by the three plates 41 to 43, so that the rigidity of each voltage monitoring terminal 80 can be improved.

D2. Modification 2:
In the second embodiment, the central layer of the tip 81 is the elastic layer 90, but instead of this, it is constituted by an intermediate plate 42 formed in a tapered shape, as in the first embodiment. You can also. Also in this configuration, since the tip of the voltage monitoring terminal 80a is tapered, the voltage monitoring terminal 80a can be easily inserted into the connector side terminal 62. In this configuration, similarly to the second embodiment, the cathode-side plate 41 and the anode-side plate 43 are bent, and the tip of the separator 40c is scraped to reduce the thickness so that the voltage monitoring terminal 80a is tapered. Can be formed.

D3. Modification 3:
In each embodiment, the protruding portions of the plates 41 to 43 constituting the voltage monitoring terminals 80 and 80a have the same shape. However, instead of this, they may have different shapes. Also in this structure, the rigidity of the voltage monitoring terminal can be improved by making the protruding portions of the plates 41 to 43 have portions that overlap each other in the stacked state.

  DESCRIPTION OF SYMBOLS 10 ... Single cell, 11 ... Oxidant gas supply manifold, 12 ... Oxidant gas discharge manifold, 13 ... Fuel gas supply manifold, 14 ... Fuel gas discharge manifold, 15 ... Coolant supply manifold, 16 ... Coolant discharge manifold, 20 ... MEA with seal, 21 ... seal part, 22 ... power generation part, 25 ... membrane electrode assembly, 26 ... porous body channel, 40, 40a, 40b, 40c ... separator, 41 ... cathode side plate, 42 ... intermediate Plates 43... Anode side plate 45. Oxidant gas supply hole 46. Oxidant gas discharge hole 47. Oxidant gas supply channel 48. Oxidant gas discharge channel 49 49 Coolant flow channel 60 ... cell monitor connector, 61 ... slot, 62 ... connector side terminal, 62a, 62b, 62d, 62e ... clamping part, 62c ... support part, 62f 62 g ... bent portion 63 ... connector terminals, 80, 80a ... voltage monitor terminal, 81 ... tip portion, 90 ... elastic layer, 100, 100a ... fuel cell stack, d1, d2 ... distance, S1 ... top

Claims (2)

A fuel cell separator used for each single cell included in the fuel cell stack,
A pair of opposing plates each having a first protrusion formed at the same position;
An intermediate plate sandwiched between the pair of plates and having a second protrusion formed at the same position as the first protrusion;
A voltage monitoring terminal for measuring a voltage of the single cell, at least part of which is formed by the stacked first protrusion and the second protrusion;
With
It said voltage monitoring terminal, possess the tip length along the stacking direction is shorter than the higher position of the tip of the first protrusion and the second protrusion,
The tip portion has a tapered shape formed by bending the two first protrusions of the pair of plates at a predetermined angle, respectively . The fuel cell separator according to claim 1,
The said front-end | tip part is a fuel cell separator currently formed of the two said 1st protrusion parts of the said pair of plate, and the elastic body pinched | interposed into the two said 1st protrusion parts.

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