JP2002358983A - Fuel cell stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell stack in which the connecting portion of the terminal plate and the power takeout cable does not become loose and bring about conduction failure even if a vibration is worked and which can maintain connection state steadily. SOLUTION: In the fuel cell stack 11, which comprises a fuel cell stack body S that has piled several pieces of electrolyte and electrode structures through a pair of separators and a terminal plate T that is provided at both ends of the fuel cell stack body S, a boss 36 is provided at the terminal plate T and a pin 43 that is connected to the power takeout cable 41 is structured capable of insertion, and a ring-shape spring member 38 elastically contacting these is provided between the boss 36 and the pin 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell stack having an improved power take-out portion.

[0002]

2. Description of the Related Art For example, a fuel cell stack in which a plurality of electrolyte / electrode structures in which an electrolyte such as a solid polymer electrolyte membrane is sandwiched between a pair of electrodes is interposed via a separator, and both ends of the fuel cell stack. A fuel cell stack having a terminal plate provided is known.

In this type of fuel cell stack, a fuel gas, for example, hydrogen gas, supplied to an anode electrode is hydrogen-ionized on a catalyst electrode and moves toward a cathode electrode via a moderately humidified electrolyte. . The electrons generated during that time are taken out to the external circuit via the terminal plate,
Used as DC electrical energy. Since an oxidant gas, for example, oxygen gas or air is supplied to the cathode electrode, the hydrogen ions, the electrons, and the oxygen gas react at the cathode electrode to generate water.

An example of this will be described with reference to FIGS. 13 to 15. In the drawings, reference numeral 1 denotes a fuel cell stack.
The fuel cell stack 1 is formed by stacking a plurality of electrolyte / electrode structures each having a solid polymer electrolyte membrane sandwiched between a cathode electrode and an anode electrode with a separator interposed therebetween. Reference numeral 2 denotes a terminal plate, which is sandwiched between the fuel cell stack 1 and an end plate 3 disposed at an end of the fuel cell stack 1. And terminal plate 2
The fuel cell stack 1 is formed by inserting stud bolts (not shown) into the fuel cell stack 1 with the components sandwiched therebetween and tightening from both sides. A terminal connection portion 4 is provided on the peripheral edge of the terminal plate 2 in a direction along the surface of the terminal plate 2, and the terminal connection portion 4 has a connection attached to the tip of a power extraction cable 5 as shown in FIGS. The part 6 is fastened and fixed to the terminal connection part 4 of the terminal plate 2 by a bolt 7 and a nut 8.

As shown in FIGS. 16 and 17, a projecting portion 9 is formed perpendicularly to the surface of the terminal plate 2 on the terminal plate 2 superposed on the fuel cell stack 1, and the projecting portion 9 is attached to an end plate. There is also a type in which a connection portion 6 at the tip of the power take-out cable 5 is fixed to a stud bolt 10 attached to the tip of the protruding portion 9 by a nut 8 (see JP-A-06-290803).

[0006]

However, in any of the fuel cell stacks, the connecting portion 6 at the tip of the power take-out cable 5 is tightened by the bolts 7 and the nuts 8. Therefore, for example, the fuel cell stack is mounted on a vehicle. When vibrations act on the fuel cell stack as in the case where the fuel cell stack is used, the bolts 7 and the nuts 8 are easily loosened at the tightened portions. There is a problem that conduction failure occurs, contact resistance increases, and electrical loss increases. Therefore, the present invention provides a fuel cell stack that can reliably maintain a connected state without causing a connection failure between a terminal plate and a power extraction cable due to loosening even when vibration is applied. .

[0007]

In order to solve the above-mentioned problems, according to the invention described in claim 1, the electrolyte (for example, the solid polymer electrolyte membrane 12 in the embodiment) is connected to a pair of electrodes (for example, in the embodiment). Electrolyte / electrode structure sandwiched between anode electrode 13 and cathode electrode 14 (for example,
The electrolyte / electrode structure 15) in the embodiment is replaced with a separator (for example, the separators 16 and 17 in the embodiment).
A fuel cell stack (for example, the fuel cell stack S in the embodiment), and terminal plates (for example, the terminal plate T in the embodiment) provided at both ends of the fuel cell stack. Fuel cell stack (for example, fuel cell stack 1 in the embodiment)
In 1), a boss (for example, the boss 36 in the embodiment) is provided on at least one of the terminal plates, and a rod-shaped electrode member connected to a power extraction member (for example, the power extraction cable 41 in the embodiment) is provided on the boss. (For example, the pin 43 in the embodiment) is configured to be insertable, and an annular spring member (for example, the spring member 38 in the embodiment) is provided between the boss and the electrode member so as to elastically contact with both. And With this configuration, when connecting the power takeout member and the terminal plate, if a rod-shaped electrode member is inserted into the boss of the terminal plate, the spring member interposed between the electrode member and the boss can be connected. By making elastic contact with both, a conduction state between them can be ensured.

[0008] In the invention described in claim 2, a fuel cell laminate in which a plurality of electrolyte / electrode structures in which an electrolyte is sandwiched between a pair of electrodes is laminated via a separator, and provided at both ends of the fuel cell laminate. In a fuel cell stack having a terminal plate, at least one of the terminal plates has a pin (for example, pin 5 in the embodiment).
3), the pin can be inserted into an insertion portion (for example, 55 in the embodiment) of an electrode member (for example, the receiving member 54 in the embodiment) connected to the power extraction member, and the pin and the insertion portion can be inserted. And an annular spring member (for example, 56 in the embodiment) elastically contacting the both is provided. With this configuration, when connecting the power extraction member and the terminal plate, if the insertion portion of the electrode member on the power extraction member side is fitted to the pin of the terminal plate, the insertion portion of the electrode member and the pin Since the spring member interposed between them elastically contacts both, a conductive state between both can be ensured.

According to a third aspect of the present invention, there is provided a pressing member (for example, the pressing member 47 in the embodiment) for preventing the electrode member from moving in the detaching direction with respect to the pin or the boss. Features. With this configuration, it is possible to prevent the pin or the boss from coming off.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, reference numeral 11 denotes a vehicle-mounted fuel cell stack. Fuel cell stack 11
Has a fuel cell stack S and terminal plates T provided at both ends of the fuel cell stack S. In the fuel cell stack S, a plurality of electrolyte / electrode structures 15 composed of a solid polymer electrolyte membrane (electrolyte) 12 sandwiched between an anode electrode 13 and a cathode electrode 14 are arranged in a horizontal direction via separators 16 and 17. They are stacked.

The separator 1 adjacent to the anode electrode 13
6, a hydrogen gas supply path 18 is formed, while an air supply path 19 is formed between the cathode electrode 14 and the adjacent separator 17. In addition, each separator 16,
A cooling medium such as pure water or ethylene glycol is supplied to the supply path 20 of the separator 16 located between the back surfaces of the
The unit fuel cell in which the electrolyte / electrode structure 15 is sandwiched between the separators 16 and 17 is cooled.
In FIG. 1, hatching indicating a cross section is omitted for convenience of illustration.

Then, in order to supply the hydrogen gas, the air, and the cooling medium to the supply paths 18, 19, and 20, the fuel cell stack S and the terminal plate T, the insulating plate 23, and the end plate 24, which will be described later. As shown in FIG. 2, communication holes 25, 26, and 27 are formed to penetrate through the respective surfaces to form an internal manifold structure.

The terminal plate T is a conductive member formed of a metal material such as copper or stainless steel or a carbon material disposed at both ends of the fuel cell stack S. An end plate 24 is arranged via an insulating plate 23 (shown in FIG. 3) made of. And this end plate 2
4, a stud bolt 28 is inserted through the insulating plate 23 and the fuel cell stack S, and a nut 29 is fastened to the stud bolt 28 to form the fuel cell stack 11.

The terminal plate T is shown in FIGS.
As shown in FIG. 3, an end plate 24 protrudes from a central portion of the flat plate portion 35 in a substantially vertical direction, that is, a direction in which the unit fuel cells 15 are stacked. And a cylindrical boss 36 passing through the receiving hole. The boss 36 is fixed to the flat plate portion 35 by welding or screwing. An annular groove 37 is formed on the inner peripheral surface of the boss 36, and a metal annular spring member 38 shown in FIGS. 6 and 7 is mounted inside the annular groove 37. As shown in FIG. 6, the spring member 38 has an inner peripheral side formed in an arc shape, and is easily bent by a slit portion 39 provided in the axial direction. Here, as the spring member 38, a member provided with notches 40 alternately from the upper and lower edges in place of the slit portion 39 as shown in FIG. 8 may be used, and as shown in FIG. The spring member 38 may have a band shape. The outer peripheral portion of the boss 36 is covered with the insulating plate 23.

On the other hand, in FIG. 4, reference numeral 41 denotes a power take-out cable (power take-out member), and a metal fitting 42 is attached to the end of the power take-out cable 41 by caulking. An electrode member 43 is joined by brazing or resistance welding. The bases of the metal fitting 42 and the pin 43 are covered with a grommet 45 made of rubber or resin attached to the end of the coating material 44 of the power take-out cable 41. A chamfered portion 46 is provided on the periphery of the tip of the pin 43 to facilitate insertion into the boss 36, and is fixed between the tip of the pin 43 and the surface of the fuel cell stack S when the pin 43 is inserted. Clearance is ensured. The pin 4 connected to the power take-out cable 41 is connected to the boss 36.
3 is configured to be insertable, and in a state where the pin 43 is inserted into the boss 36, as shown in FIG.
A pressing member 47 having a semicircular shape in a top view for preventing the moving member 3 from moving in the pull-out direction is attached to the end plate 24 by a bolt 48.

Here, as shown in FIG. 3, a boss 36 of a terminal plate T formed on the end plate 24 is provided.
A stepped portion 52 is formed on the outer peripheral edge of the receiving hole, and a rubber cap-shaped grommet 49 is formed in the stepped portion 52.
Is attached. Most of the receiving holes of the terminal plate T are closed by the grommet 49, so that foreign substances are hard to enter from here. A flange 50 is formed on the outer peripheral surface of the grommet 49, and the flange 50 is connected to the holding member 47 and the end plate 24.
It is designed to be sandwiched and fixed between them.

Here, as shown in FIG.
A ball 51 is interposed between the outer peripheral surface of the boss 36 and the inner peripheral surface of the boss 36, and the ball 43 can be urged by a spring (not shown) to engage the pin 43 and the boss 36 with a sense of moderation. It is. Further, as shown in FIG. 11, an annular groove 37 may be formed on the outer peripheral surface side of the pin 43, and a spring member 38 may be provided here.

Each of the communication holes 25, 2 shown in FIG.
6, 27, specifically, each communication hole 2 of the end plate 24.
Air, hydrogen gas, and cooling medium supply / discharge pipes (not shown) are connected to 5, 26, and 27, respectively.
The cooling medium flows so as to make a U-turn inside the fuel cell stack 11, and the two power extraction cables 41
Power is extracted from the power supply to an external circuit.

Next, the operation will be described. In connecting the power take-out cable 41 to the terminal plate T, first, the bolts 48 in FIGS. 3 and 4 are removed, and the pressing member 47 and the grommet 49 are removed from the end plate 24. Next, when the pin 43 at the end of the power take-out cable 41 is inserted into the boss 36 of the terminal plate T, the spring member 38 attached to the annular groove 37 of the inner peripheral wall of the boss 36 is attached to both the boss 36 and the pin 43. Make contact Therefore, the boss 36 and the pin 43, that is, the terminal plate T and the power take-out cable 41 conduct. And
The grommet 49 is attached to the step portion 52 of the receiving hole of the end plate 24, and then the holding member 47 is
Therefore, if the pin 43 is tightened to the end plate 24, the pin 43 can be prevented from falling off from the terminal plate T and can be attached. Therefore, for example, when the fuel cell stack 1 is used for a vehicle,
Even if the fuel cell stack 11 is vibrated, the conduction between the boss 36 and the pin 43 is maintained.

According to the above embodiment, the boss 36 has a pin 4
3, the terminal plate T and the power take-out cable 41 can be easily connected. Further, while the fuel cell stack 11 is vibrated while the vehicle is running, even if the vibration is applied, the spring member 38 is moved by the boss 36.
The terminal plate T and the power take-out cable 41 can be reliably connected to each other without any poor conduction by making elastic contact with both the pin 43 and the pin 43. Therefore, it is suitable as an in-vehicle fuel cell stack. Also,
Since the pin 43 having a circular cross section is used, rotation around the axis is allowed, and a biased force does not act on the power extraction cable 41. As a result, it is possible to improve the reliability without causing a loss in electrical contact due to an increase in contact resistance due to loosening of the tightened portion due to vibration as in the related art. Pin 4
When the pin 43 is inserted into the boss 36, the pressing member 47 for preventing the pin 43 from moving in the removal direction with respect to the boss 36.
Is provided, the terminal plate T can reliably prevent the power take-out cable 41 from falling off.

As described above, at the connection portion between the pin 43 and the boss 36, the spring member 3 is provided as a measure against vibration.
By providing the holding members 47 as separate members as measures against the slippage, the conductivity is not impaired even when the vibration by the spring member 38 acts, and each function can be exhibited without adversely affecting each other. it can.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the basic structure is the same as that of the first embodiment, but the pin 43 in the first embodiment is used.
Instead, a concave receiving member (electrode member) 54 connected to the power take-out cable 41 is provided, and a pin 53 having a circular cross section is provided on the terminal plate T instead of the boss 36 of the first embodiment. . Terminal plate T
The pin 53 is configured to be insertable into the insertion portion 55 of the concave receiving member 54 connected to the power take-out cable 41. An annular groove 56 is formed on the inner peripheral wall of the receiving member 54, and an annular spring member 56 elastically contacting the pin 53 and the insertion portion 55 is mounted in the annular groove 56. Note that the other configuration is the same as that of the first embodiment, and thus the same portions are denoted by the same reference numerals and description thereof will be omitted.

Also in this embodiment, the terminal plate T and the power take-out cable 41 can be easily connected only by inserting the pins 53 into the insertion portions 55 of the receiving members 54 and attaching the receiving members 54 to the pins 53. Can be connected. Further, while the fuel cell stack 11 is vibrated while the vehicle is running, even if the vibration is applied, the spring member 56 elastically contacts both the receiving member 54 and the pin 53, so that the conduction state between both is ensured. Therefore, the terminal plate T and the power take-out cable 41 can be reliably connected without poor conduction. As a result, it is possible to improve the reliability without causing a loss in electrical contact due to an increase in contact resistance due to loosening of the tightened portion due to vibration as in the related art.

Further, since the receiving member 54 is prevented from coming off from the pin 53 by the pressing member 47 as in the above-described embodiment, the mounting reliability can be improved. In particular, in this embodiment, the insertion portion 55 of the receiving member 54 attached to the power extraction cable 41 is
Is advantageous in that it is not easily exposed to scratches or damage because it is not exposed to the outside unlike the pin 43 of the first embodiment.

The present invention is not limited to the above-described embodiment. For example, the boss 36 of the terminal plate may be used.
Is not limited to the through hole as long as the pin 43 can be inserted, and may be a concave portion. Also, the case where the pins 43 and 53 are formed in a circular cross section has been described, but various cross sectional shapes such as a triangle and a quadrangle can be adopted.

[0026]

As described above, according to the first aspect of the present invention, when connecting the power extraction cable and the terminal plate, if the rod-shaped electrode member is inserted into the boss of the terminal plate, Since the spring member interposed between the electrode member and the boss resiliently contacts the both, a conductive state between the two can be secured, so that even if vibration is applied, the terminal plate and the power takeout cable can be connected without poor conduction. There is.

According to the second aspect of the invention, when connecting the power take-out cable and the terminal plate, if the insertion portion of the electrode member on the power take-out cable side is fitted to the pin of the terminal plate, Since the spring member interposed between the insertion portion of the member and the pin elastically contacts the both, a conductive state between the two can be ensured, so that even if vibration is applied, the terminal plate and the power extraction cable can be connected without poor conduction. effective.

According to the third aspect of the present invention, the pin or the boss can be prevented from coming off, so that the power take-out cable can be reliably prevented from dropping from the terminal plate.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fuel cell stack according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view of a main part of FIG.

FIG. 4 is an exploded view of FIG.

FIG. 5 is a plan view showing the vicinity of a pressing member.

FIG. 6 is a sectional view taken along the line BB of FIG. 7;

FIG. 7 is a plan view of a spring member.

FIG. 8 is a cross-sectional view corresponding to FIG. 6 of another spring member.

FIG. 9 is a plan view of another spring member.

FIG. 10 is an enlarged sectional view of FIG. 3 to which a member for retaining is attached.

FIG. 11 is an enlarged sectional view of FIG. 3 using another spring member.

FIG. 12 is a sectional view corresponding to FIG. 3 of a second embodiment of the present invention.

FIG. 13 is a schematic front view of a conventional fuel cell stack.

FIG. 14 is a plan view of FIG.

FIG. 15 is an enlarged view of a connection portion according to the related art.

FIG. 16 is a schematic front view of another conventional fuel cell stack.

FIG. 17 is a plan sectional view of FIG. 16;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Fuel cell stack 12 Solid polymer electrolyte membrane (electrolyte) 13 Anode electrode 14 Cathode electrode 15 Electrolyte / electrode structure 16, 17 Separator 36 Boss 38, 56 Spring member 41 Power extraction member (power extraction cable) 43 Pin (electrode member) ) 47 pressing member 53 pin 54 receiving member (electrode member) 55 insertion portion S fuel cell stack T terminal plate

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masahiko Sato 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. 5H026 AA06 CX08 CX09

Claims (3)

[Claims] An electrolyte comprising an electrolyte sandwiched between a pair of electrodes.
In a fuel cell stack having a fuel cell stack in which a plurality of electrode structures are stacked with a separator interposed therebetween and terminal plates provided at both ends of the fuel cell stack, a boss is provided on at least one of the terminal plates, A fuel cell stack, wherein a rod-shaped electrode member connected to a power take-out member is inserted into the boss, and an annular spring member elastically contacting the boss and the electrode member is provided between the boss and the electrode member. . 2. An electrolyte comprising an electrolyte sandwiched between a pair of electrodes.
In a fuel cell stack having a plurality of electrode structures stacked with a separator interposed therebetween and a terminal plate provided at both ends of the fuel cell stack, a pin is provided on at least one of the terminal plates, The fuel cell stack, wherein the pin is configured to be insertable into an insertion portion of an electrode member connected to a power take-out member, and an annular spring member is provided between the pin and the insertion portion so as to resiliently contact both the pin and the insertion portion. . 3. The fuel cell stack according to claim 1, further comprising a pressing member for preventing the electrode member from moving in a detaching direction with respect to the pin or the boss.