JPS62110268A - Fuel cell - Google Patents

Abstract

PURPOSE:To make it possible to fasten unit cells at an even pressure, by fastening them through a member with a projection on the surface contacting to the cells. CONSTITUTION:On the unit cells 1 piled with the recessed side up, a fastening metal 2a with a projecting side down is placed, and depressed by fastening rods 3. The projection of the fastening metal 2a is formed in a spherical surface with a curvature less than that of the recession of the unit cell 1. Therefore, the center of the unit cells 1 is depressed initially, then the edge side is pressed gradually, and a relaxation or discrepancy produced in the piling are corrected while depressing, resulting in an even fastening.

Description

[Detailed description of the invention] (Field of application of the invention) The present invention relates to fuel cells.

[Background of the invention]

FIG. 3 shows a conventional example of a fuel cell.

As shown in the figure, the fuel cell consists of a plurality of stacked unit cells 1 which are tightened with tightening fittings 2 placed above and below them. Niko 9
It is being done.

In a fuel cell configured in this manner, if the rigidity of the clamping fitting 2 is sufficiently large and the thickness of the unit cell 1 is uniform, a uniform clamping pressure distribution can be provided to the unit cell 1. However, in reality, due to variations in the thickness of unit cells when stacking them, the center part becomes convex (see figure (a)) or concave (see figure 4 (a)), as shown in Figures 4 (a) and (b). (See Figure (b)).

In this case, the tightening pressure is equalized in the state shown in Fig. 4 (a), but in the case shown in Fig. 5 (b), the tightening pressure is equalized as shown in Fig. 5. The tightening distribution is large at the four corners and small at the center, and the pressure is applied around the first corner and then to the center, first at the four corners and last at the center. In this way, with both ends of the unit battery restrained, the unit battery becomes deaf when it is pressurized, and as shown in Figure 6, the unit battery 1
It was not possible to correct the deflection that occurred during the process, resulting in uneven clamping pressure distribution and increased contact resistance.

Regarding this, Japanese Patent Application Laid-Open No. 58-164168
There is a publication.

[Purpose of the invention]

The present invention has been made in view of the above points, and it is an object of the present invention to provide a fuel cell that makes it possible to equalize the clamping pressure of unit cells.

[Summary of the invention]

That is, the present invention comprises a plurality of unit cells with a stack of 1@'7'', and the stacked unit cells are tightened with fasteners disposed above and below the stacked unit cells. , the unit battery is tightened through a member having a convex portion on the contact surface side with the unit battery, whereby the unit battery is tightened in the order of the central part and the end part. Applying pressure can now be applied.

[Example of Haimei]

The present invention will be explained below based on the illustrated embodiments. An embodiment of the present invention is shown in FIGS. 1(a) and 1(b). Note that parts that are the same as those in the conventional system are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, the unit battery 1 is tightened through a member having a convex portion on the contact surface side with the unit battery 1, for example, a fastening fitting 28 having a convex portion on the contact surface side. By doing this, the unit battery 1 is tightened via the clamping fitting 2a which has a convex portion on the contact surface side with the unit battery 1, and the unit current l is applied between the center part and the end part. It is possible to obtain a fuel cell in which the clamping pressure can be clearly applied (9), and the clamping pressure of the unit cells 1 can be made uniform.

That is, a fastening fitting 2a having a convex portion on the lower side is attached to the upper part of the unit batteries 1 which are stacked in a concave state on the upper side.
Place and pressurize with tightening rod 3. Note that the convex portion of the fastening metal fitting 2a is formed into a spherical shape with a smaller curvature than the curvature of the concave portion of the unit battery 1. By doing this, the unit battery l
Pressure is applied to the center of the stack, and then force is gradually applied to the edges, making it possible to apply pressure while outwardly correcting deflections and misalignments that occur during stacking, ensuring uniform tightening. It can be done. That is, the central portion is pressurized first, but as the pressurizing force increases, the gaps between the unit batteries 1 become clogged, and the displacement in the plane direction that occurs at that time can be released to the outside. Furthermore, the clamping fitting 2a itself also bends due to the clamping pressure, and the curvature of the contact part with the unit battery 1 increases, so that the entire clamping bracket 2a pressurizes the unit battery 1, and the clamping pressure is made uniform. Therefore, the contact resistance between the unit batteries 1 can be reduced.

Another embodiment of the invention is shown in FIG.

In this embodiment, at least one of the fastening fittings 2 and the unit battery 1 are connected to a member having a convex portion on the contact surface side with the unit cell and the pond l.
A pressure equalizing plate 4 was provided between the two.

By doing so, the clamping pressure is applied to the unit battery 1 by the pressure equalizing plate 4 in the central part and then the end part, and the same effect as in the case described above can be achieved. Note that it is effective to make the pressure equalizing plate 4 concave on the side of the fastening fitting 2 and made of an elastic body.

〔Effect of the invention〕

As described above, the present invention makes it possible to obtain a fuel cell in which the clamping pressure of the unit cells is made uniform, thereby making it possible to equalize the clamping pressure of the unit cells.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) show the state in which the unit cells are tightened using a tightening fitting provided with a convex portion in an embodiment of the fuel cell of the present invention, and FIG. 1(a) shows the state in which the unit cells are stacked; (b) is a side view showing the state before and after tightening with the fastening fitting, FIG. 2 is a 011 side view showing the state when unit current is tightened in another embodiment of the fuel cell of the present invention, and FIG. 4 is a side view of a conventional fuel cell, and FIGS. 4(a) and 4(b) show the stacked state of the unit cells of the conventional fuel cell. (a) shows a convex stacked state, and (b) shows a concave stacked state. Fig. 5 is a stress distribution diagram when unit cells are tightened in a concave state of a conventional fuel cell, and Fig. 6 is a side view showing the stacked state of unit cells after tightening of a conventional fuel cell. It is a diagram. l...Unit r"Pond, 2.2a...Tightening fitting, 3...
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Claims (1)

[Claims] 1. A fuel cell comprising a plurality of stacked unit cells, and the stacked unit cells are fastened with fastening fittings disposed above and below the stacked unit cells. 1. A fuel cell characterized in that the fuel cell is tightened through a member having a convex portion on the side of the contact surface with the unit cell. 2. The fuel cell according to claim 1, wherein the member is formed of at least one of the fastening metal fittings. 3. The fuel cell according to claim 1, wherein the member is formed of a pressure equalizing plate provided between at least one of the fastening fittings and the unit cell.