JP2004327125A - External manifold type fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact manifold fastening mechanism by securing sealing surface pressure on a layered product side surface. <P>SOLUTION: Manifolds 2A and 2B and manifolds 3A and 3B are installed on the respective side surfaces of the layered product 1 by interlaying a sealing material 6 and by interlaying a sealing material 7, respectively. The manifolds 3A and 3B facing to each other by interposing the layered product 1 also function as fastening members for the facing manifolds 2A and 2B. Tapered parts 8 are formed outside the manifolds 2A and 2B. The manifolds 3A and 3B have tilting parts 9 each having an angle equivalent to those of the taper parts 8 of the manifolds 2A and 2B. By fastening each rod 4 by a nut 5, the sealing surface pressure between the manifolds 3A and 3B and the layered product 1 is secured; and the sealing surface pressure between the manifolds 2A and 2B and the layered product 1 is secured by force transmitted from the tilting parts 9 to the tapered parts 9. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an external manifold type fuel cell that supplies or discharges a fluid such as a fuel gas or an oxidizing gas through an external manifold disposed on a side surface of a substantially rectangular parallelepiped stack of unit cells.
[0002]
[Prior art]
A fuel cell is usually formed as a stacked body in which a plurality of unit cells are stacked and connected in series because the electromotive force of the unit cells is as low as about 1 V. The external manifold type fuel cell is one in which a manifold for supplying / discharging a reaction gas to / from the laminate and supplying / discharging the cooling liquid is separately provided on a side surface of the laminate.
[0003]
In an external manifold type fuel cell, it is necessary to provide a seal layer so that a reaction gas and a cooling liquid do not leak between the stacked body and the manifold installed on the side surface thereof.
[0004]
However, there are irregularities on the side surfaces of the stacked body due to dimensional errors of the electrodes and separators constituting the unit cell, and it is difficult to secure a highly reliable seal as compared with the internal manifold type fuel cell.
[0005]
Therefore, in order to ensure a high sealing surface pressure, springs and nuts are installed at both ends of a rod penetrating the manifold, and the opposing manifolds are tightened by the elastic force of the spring (for example, Patent Document 1).
[0006]
[Patent Document 1]
JP-A-7-45300 (page 3, FIG. 3)
[0007]
[Problems to be solved by the invention]
In recent years, particularly in mobile fuel cells, demands for higher output density have been increasing, and making a compact shape is a major issue to be studied.
[0008]
However, in the external manifold type fuel cell in which the manifolds are installed on the four sides of the laminate, there are two sets of opposed manifolds, and there are also rods for clamping the laminate, so that a total of three directions of clamping rods are required. is there.
[0009]
Such an external manifold type fuel cell has a problem that it has a complicated structure, poor workability at the time of assembly, and a large external shape.
[0010]
[Means for Solving the Problems]
The external manifold type fuel cell according to the present invention, in order to solve the above-described problems, a fluid such as a fuel gas or an oxidizing gas is supplied through an external manifold disposed on a side surface of a substantially rectangular parallelepiped stack in which unit cells are stacked. In the supply / discharge external manifold type fuel cell, a tapered portion is provided outside at least one set of external manifolds disposed on the mutually facing side surfaces of the stack, and a fastening member for fastening the external manifold to the stack is provided. An inclined portion having an angle equal to that of the tapered portion is provided at a contact portion that comes into contact with the tapered portion, and the tightening member applies a tightening force to the tapered portion from a direction different from a direction of tightening the external manifold to the laminate. The gist of the present invention is to convert the input force into a force for tightening the external manifold.
[0011]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the external manifold type fuel cell which concerns on this invention, since the force from the direction different from the direction which tightens an external manifold can be converted into the direction which tightens an external manifold, the flexibility of arrangement | positioning of a tightening rod increases and a fuel cell is compact. There is an effect that a simple structure can be obtained.
[0012]
Further, since the external manifold can be tightened by using the tightening force for tightening another object, there is an effect that the number of parts can be reduced by also using the part that applies the tightening force.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
FIG. 1 is a cross-sectional view illustrating a configuration of a first embodiment of an external manifold fuel cell according to the present invention. A fuel cell stack (also called a stack) 1 is formed by stacking a plurality of unit cells. Each unit cell is configured by sandwiching a membrane electrode assembly having electrodes formed on both sides of a solid electrolyte membrane on both sides with separators.
[0014]
The manifolds 2A, 2B, 3A, and 3B are respectively supplied with fluids for supplying and discharging fluids to fuel gas such as hydrogen, oxidizing gas such as air, and cooling water supply / discharge holes on the side surface of the laminate 1. Passages 10A, 10B, 11A, 11B are formed.
[0015]
Manifolds 2A and 2B are installed on each side surface of the laminate 1 via a sealing material 6, and manifolds 3A and 3B are installed via a sealing material 7. The manifolds 3A and 3B opposed to each other with the stacked body 1 interposed therebetween also function as a fastening member for the opposed manifolds 2A and 2B.
[0016]
A tapered portion 8 is formed outside the manifolds 2A and 2B. Each of the manifolds 3A and 3B has an inclined portion 9 having the same angle as the tapered portion 8 of each of the manifolds 2A and 2B.
[0017]
Adjacent manifolds are in contact with each other at an inclined portion 9 and a tapered portion 8. Two rods 4 penetrate the manifolds 3A and 3B in the figure. By tightening these rods 4 with nuts 5, a sealing surface pressure between the manifolds 3A and 3B and the laminated body 1 is secured.
[0018]
Further, the clamping pressure in the lateral direction of the rod 4 in the drawing is converted into a force for pressing the manifolds 2A, 2B toward the laminate 1 by the inclined portion 9 and the tapered portion 8 abutting on the inclined portion 9, and the manifolds 2A, 2B and the laminate 1 The seal surface pressure is secured during
[0019]
Therefore, the sealing surface pressure of the two sets of external manifolds (3A, 3B) and (2A, 2B) can be secured by the force for tightening the one set of external manifolds (3A, 3B), and the outer shape of the fuel cell is reduced in size and the vehicle is made compact. There is an effect that the mountability can be improved.
[0020]
In addition, by making the manifolds 3A and 3B also function as fastening members for the manifolds 2A and 2B, the fastening structure is simplified, the number of parts and the number of working parts are reduced, so that cost reduction and quality stabilization can be achieved. There is.
[0021]
In the present embodiment, if the tapered portion and the inclined portion are formed over the entire length direction, the contact surface with the tapered portion and the inclined portion can function as a seal against the outside (atmosphere) of the manifolds 3A and 3B. Supplies fuel to manifolds 3A and 3B. When used as an exhaust manifold, there is an effect that a highly reliable fuel cell that can more reliably suppress fuel gas leakage can be provided.
[0022]
[Second embodiment]
FIG. 2 is a cross-sectional view illustrating the configuration of a second embodiment of the external manifold fuel cell according to the present invention.
[0023]
The second embodiment shows an example in which the outer manifold is tightened by a force for tightening the laminate. End plates 12 </ b> A and 12 </ b> B for tightening the multilayer body 1 are arranged at both ends of the multilayer body 1 similar to the first embodiment. Other components are the same as those of the first embodiment shown in FIG. 1, and therefore, the same components are denoted by the same reference numerals, and overlapping description will be omitted.
[0024]
The end plates 12A and 12B have a role of a fastening member for fastening the laminate 1 in the stacking direction and a role of a fastening member for the external manifolds 2A and 2B.
[0025]
The two rods 4 and the nut 5 fasten the end plates 12A and 12B to each other, and thus tighten the laminate 1 in the laminating direction.
[0026]
The tapered portions 8 of the external manifolds 2A and 2B are in contact with the inclined portions 9 formed on the end plates 12A and 12B, and the force for tightening the end plates 12A and 12B is reduced by the inclined portions 9 and the tapered portions 8 to the manifold 2A. , 2B is converted into a force in the direction of tightening the laminate 1.
[0027]
Furthermore, although not shown in the figure, by arranging another set of manifolds in the same manner, it is possible to tighten the two sets of manifolds by tightening the laminated body, and it is possible to originally tighten the manifold in three directions. The rod can be reduced in one direction.
[0028]
As a result, not only can the fuel cell be made compact to improve vehicle mountability, but also the productivity can be improved by reducing the number of working parts during assembly.
[0029]
[Third embodiment]
FIG. 3 is a cross-sectional view illustrating a configuration of an external manifold fuel cell according to a third embodiment of the present invention.
[0030]
The third embodiment is different from the first embodiment in that the inclined portions 9 are not formed directly on the external manifolds 3A and 3B which also serve as fastening members, and the inclined members 13 having the inclined portions 9 are provided with the elastic body 14 interposed therebetween. That is the point. The outer manifolds 2A and 2B and the tapered portions 8 formed thereon are the same as in the first embodiment. Other components are the same as those in the first embodiment shown in FIG. 1, and therefore, the same components are denoted by the same reference numerals, and redundant description will be omitted.
[0031]
Although not particularly limited, it is preferable that the inclined member 13 and the elastic body 14, and the elastic body 14 and the external manifolds 3A and 3B are integrally bonded for assembly or maintenance after shipment. The inclined portion 9 formed on the inclined member 13 has the same function as the inclined portion 9 of the first embodiment.
[0032]
In the present embodiment, by sandwiching the elastic body 14, there is an effect that the required dimensional accuracy of the external manifolds 2A, 2B, 3A, 3B where the tapered portion 8 and the inclined portion 9 abut can be reduced.
[0033]
Further, when the tightening force of the rod 5 is reduced due to the prolonged operation of the fuel cell, it is necessary to readjust the tightening force by retightening, but the time interval for the readjustment is extended by the elastic body. This has the effect that the maintenance cost of the fuel cell can be reduced.
[0034]
[Fourth embodiment]
FIG. 4 is a sectional view illustrating the configuration of a fourth embodiment of the external manifold fuel cell according to the present invention.
[0035]
The fourth embodiment has a structure in which the inclined portions 9 of the external manifolds 3A and 3B are movable. For this reason, in the present embodiment, the inclined member 13 is provided as an independent component having the inclined portion 9 in contact with the tapered portion 8, and the inclined member 13 is attached to the manifolds 3 </ b> A and 3 </ b> B via the adjustment bolt 15. . By rotating the adjustment bolt 15 left and right, the inclined member 13 can be made to approach or be separated from the manifolds 3A and 3B. Other components are the same as those of the first embodiment shown in FIG. 1, and therefore, the same components are denoted by the same reference numerals, and overlapping description will be omitted.
[0036]
At the time of assembling the fuel cell, first, the adjusting bolt 15 is loosened, and the external manifolds 3A and 3B are tightened to the stacked body 1 by the rod 4 and the nut 5. The tightening by the rod 4 and the nut 5 is performed by a pair of the external manifold 3A. 3B, and is not related to the clamping force of the external manifolds 3A, 3B. Next, the adjustment member 15 is tightened to push the inclined member 13 into the fuel cell, whereby the inclined portion 9 of the inclined member 13 presses the tapered portions 8 of the external manifolds 2A and 2B toward the stacked body 1 and the external manifold 2A. 2B.
[0037]
When the inclined portion 9 is fixed to the external manifolds 3A and 3B as in the first embodiment (FIG. 1), the tightening force of the two sets of manifolds (2A and 2B) and (3A and 3B) is individually adjusted. Can not. That is, when trying to adjust one set of tightening forces, the other set of tightening forces also changed.
[0038]
In the present embodiment, by installing the adjustment bolt 15, there is an effect that the tightening force can be individually adjusted. Further, there is an effect that the required dimensional accuracy of the external manifold can be reduced.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a configuration of a first embodiment of an external manifold type fuel cell according to the present invention.
FIG. 2 is a cross-sectional view showing a configuration of an external manifold fuel cell according to a second embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a configuration of a third embodiment of the external manifold fuel cell according to the present invention.
FIG. 4 is a sectional view showing a configuration of a fourth embodiment of an external manifold type fuel cell according to the present invention.
[Explanation of symbols]
1 ... Laminate (stack)
2A, 2B ... external manifold 3A, 3B ... external manifold (clamping member)
4 Rod 5 Nut 6, 7 Sealing Material 8 Taper 9 Slope 10A, 10B Fluid Passage 11A, 11B Fluid Passage

Claims (8)

In an external manifold fuel cell that supplies or discharges a fluid such as a fuel gas or an oxidizing gas through an external manifold disposed on a side surface of a substantially rectangular parallelepiped stacked body in which unit cells are stacked,
Providing a tapered portion on the outside of at least one set of external manifolds disposed on mutually facing side surfaces of the laminate,
A tightening member for tightening these external manifolds to the laminate is provided with an inclined portion having an angle equivalent to the tapered portion at a contact portion where the tightening member contacts the tapered portion,
The external manifold type fuel cell, wherein the tightening member converts a tightening force from a direction different from a direction in which the external manifold is tightened into the stack into a force to tighten the external manifold by inputting the tightening force into the tapered portion. . The external manifold type fuel cell according to claim 1, wherein the tightening member is configured to apply a tightening force in a direction to tighten an external manifold different from the external manifold. The external manifold type fuel cell according to claim 2, wherein the fastening member is formed integrally with the another external manifold. The external manifold type fuel cell according to claim 1, wherein the fastening member is configured to apply a fastening force in a direction of fastening the stacked body in a stacking direction. The external manifold type fuel cell according to claim 4, wherein the fastening member is formed integrally with an end plate for fastening the stacked body in the stacking direction. The external manifold type fuel cell according to claim 1, wherein an inclined portion of the fastening member is movable. The external manifold type fuel cell according to claim 6, wherein the inclined portion of the fastening member is movable via an elastic body. The tapered portion and the inclined portion are formed over the entire length of the laminate,
The external manifold type fuel cell according to claim 3, wherein the another external manifold is a fuel supply or fuel discharge manifold.

Images