JPH01235165A - Fuel cell manifold - Google Patents

Abstract

PURPOSE:To increase the strength and rigidity of a rubber manifold, to thin the rubber thickness, and to make it lightweight by bonding a reinforcer on the surface of the manifold or burying in its inside. CONSTITUTION:In a rubber manifold with which a reaction gas is supplied to or exhausted from the side of a fuel cell stack 2, a reinforcer 8 is bonded on its surface or buried in its inside. As the reinforcer 8, inorganic fibers, a metal mesh, or a metal thin plate is used. The reinforcer 8 is made thin and flexible, and the manifold 1 is reinforced with the advantage of rubber retained. The thickness of the manifold is made thin to make it lightweight.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a fuel cell that generates electricity by supplying a reactive gas to positive and negative electrodes arranged with an electrolyte sandwiched therebetween, and particularly to a manifold that supplies or exhausts the reactive gas.

[Conventional technology]

In a fuel cell, a fuel cell stack is constructed by stacking unit cells consisting of an air electrode, an electrolyte-impregnated matrix, and a hydrogen electrode in a columnar manner. is supplied to generate electricity. To this end, manifolds for supplying or exhausting reactive gases (air and fuel gas) are attached to all four sides of the fuel cell stack. Conventionally, this manifold has mostly been made of metal such as stainless steel, but recently, manifolds made of rubber have been proposed. FIG. 3 shows a state in which a conventional rubber manifold is attached to a fuel cell stack. In FIG. 3, the connection between the opening flange portion 1a of the manifold 1 and the side surface of the fuel cell stack 2 is achieved by applying a metal annular seat 3 to the back surface of the opening flange portion 1a, and attaching bolts 4 to the periphery of the fuel cell stack 2. This is done by tightening the In addition, the connection with the reaction gas supply/discharge pipe 5 is made at the connection part 1 of the manifold 1.
b is sandwiched between the flange portion 5a of the supply/discharge pipe 5 and an annular stopper 6 and tightened with bolts 7. This rubber manifold has the following features. (1) By using rubber or foamed rubber with low specific gravity, it is lighter than metal. (2) Since it can be manufactured by integral molding, it can be mass-produced at low cost. (3) Since it is possible to expand and contract to a certain extent, the allowable value of dimensional accuracy can be increased, and dimensional changes due to temperature changes can be absorbed by the manifold itself. (4) Rubber material has excellent electrical insulation properties, so there is no need to worry about short circuits through the manifold.

[Problem to be solved by the invention]

By the way, since rubber is naturally softer than metal, it must be made considerably thicker in order to withstand the gas pressure inside the fuel cell and to maintain its shape as a manifold. Depending on the case, this wall thickness may need to be 5 to 10 times that of metal, and in that case, the result will be that it is not much different in weight from a metal manifold. It is an object of the present invention to provide a rubber manifold for a fuel cell that is lightweight and does not impair the above-mentioned advantages of the rubber manifold.

[Means to solve the problem] In a rubber manifold that supplies or exhausts reactive gas from the side of a fuel cell stack in which unit cells are stacked in a columnar manner, a reinforcing material is either bonded to the surface or embedded inside. As the reinforcing material, an inorganic fiber material, a wire mesh, a metal delta plate, etc. can be used. [For use]

By reinforcing it with a reinforcing material, the wall thickness can be reduced accordingly, and as a result, the weight can be reduced. In addition, the reinforcing material bonded to the surface or embedded inside can be made thin and stretchable, so it can be reinforced without impairing the various advantages mentioned above of the rubber material that is the main body of the manifold. .

【Example】

FIG. 1 is a sectional view showing a first embodiment of the invention. In FIG. 1, a rubber manifold 1 has an open flange portion 1a and a connection portion 1b with a supply/discharge pipe 5 on its outer surface.
A reinforcing material 8 made of glass fiber cloth is bonded to the reinforcing material 8 using a heat-resistant adhesive. As a result, the pressure resistance is increased, and the thickness of the rubber material constituting the manifold 1 can be reduced to about 1/2 compared to a case without reinforcing material. If this reinforcing material 8 is made of a wire mesh, the thickness of the rubber material can be further reduced to 1/2, although it depends on the wire diameter. Further, as the other reinforcing material 8, a thin metal plate having a thickness of 2 mm or less can be used. When joining a thin metal plate to the outer surface of the manifold l, this thin plate does not require highly difficult manufacturing techniques such as high processing accuracy on the sealing surface and airtightness of the welded part, which are required for metal manifolds. therefore,
The manufacturing cost in that case is much lower than that of a metal manifold, and even if you add that cost to a rubber manifold, the overall cost is lower than that of a metal manifold. FIG. 2 shows another embodiment. In this case, a reinforcing member 8 made of wire mesh is embedded inside the manifold 1. With this structure, when molding the manifold 1, a wire mesh is buried in the mold along with rubber, or after the wire mesh is bonded to the outer surface as shown in Fig. 1, colloidal latex dissolved in a solvent is added to the surface. It can be formed by coating. In this case as well, the first step is to bond the wire mesh to the outer surface.
It is possible to obtain the same or higher strength with the same wall thickness as in the case shown in the figure.

【Effect of the invention】

According to this invention, the strength and rigidity of the rubber manifold are increased, so the thickness of the rubber material can be kept small, and the weight can be reduced while taking advantage of the features of the rubber manifold.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view of another embodiment, and FIG. 3 is a sectional view illustrating a conventional manifold installation state. 1: Manifold, 2: Fuel cell stack, 8: Reinforcement material. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1) A rubber manifold that supplies or exhausts reactive gas from the side of a fuel cell stack in which unit cells are stacked in a columnar manner, characterized by having a reinforcing material bonded to the surface or embedded inside. Fuel cell manifold.