JPS6398969A - Sealing method for fuel cell - Google Patents

Abstract

PURPOSE:To increase the sealing capability and insulation capability between a stack and a frame by forming adjacent three lines of grooves on the surface of a gasket comprising cured fluorine rubber fitted to a frame, fitting an O-ring shaped uncured fluorine rubber in each groove, and curing the uncured rubber to uniting them and to form a sealing member. CONSTITUTION:A gasket 5 comprising cured fluorine rubber is fitted to a recessed part 4 installed on the sealing surface of a frame 1. Adjacent three lines of semicircular grooves 6 are formed in the gasket 5, and O-ring-shaped uncured fluorine rubbers 7 and 6 are fitted to each groove. When the frame 1 fitted with a sealing member 3 is temporarily fastended, three lines of uncured fluorine rubbers 7 and 8 closely contact with the sealing surface of a cell stack 2. The irregularities on the stack surface are absorbed to make the contact close. A pair of uncured rubbers 7 on both diside are cured, and after refastening, the inside uncured rubber 8 is cured and they are united. Thereby, effective sealing area on the stack surface is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a fuel cell sealing method C2, specifically, between a battery stack and a manifold mounting frame that elastically tightens the stack from the outer periphery. This relates to sealing method C2.

(Shun) Prior Art The present applicant proposed a method of indirectly attaching one manifold to the MLq stack using a rigid frame that tightens the battery stack from the outer periphery in advance without attaching a contact manifold.
J, 4=I 1976-197679) I proposed c.

With this method, the manifold can be installed by tightening bolts around the entire circumference of the frame, and the sealing is simple and reliable, but the seal between the battery stack and the frame is
Since the stack stacking surface has irregularities, the commonly used vulcanized fluororubber (product name: Paiton Rubber) has the disadvantage of lacking flexibility and adhesion to the stack surface.

7, as shown in Figure 5, a pair of vulcanized fluorine rubber (1) (2) flexible Q
A method of reinforcing the tightness by inserting a ring-shaped raw rubber 1crljz or the like could be considered, but there was a problem that the effective sealing area for the stack (21) was small and sufficient sealing performance could not be obtained.

! / Mouse The problem that the invention aims to solve This invention is '1
The above-mentioned problems are solved by improving the resistance to the pond stack surface and expanding the effective sealing area.

! 2 Means for Solving the Problems This invention provides a sealing member on each peripheral surface of the stack.
The elastic C=
When connecting and tightening the stack along the outer periphery, three adjacent grooves are formed on the surface, and these grooves are each shaped like an O-ring (unvulcanized fluorine rubber). Swallow, and after temporarily tightening the frame so that the three stripes of unvulcanized fluorine-based rubber come into close contact with the stack surface, the pair of unvulcanized rubber located on both sides first (;
After vulcanization, the frame body is finally tightened by vulcanizing the unvulcanized rubber located at the rear intermediate position to integrate the three parts to form the sealing member.

Function: In this invention, the three strips of fluororubber are in an unvulcanized state with good flexibility, and when temporarily tightened, the battery stack surface (the two are in close contact with each other, so
It absorbs the unevenness of the stack surface and has good tightness, and the pair of unvulcanized rubbers on both sides are first 110 vulcanized, and the main tightening is done later (the unvulcanized rubber in the middle is vulcanized). Since they are integrated together, the effective sealing area that is in close contact with the stack surface can be increased.

Furthermore, since these three strips of fluorocarbon rubber are attached to the frame via a gas get made of vulcanized fluorocarbon rubber, this contributes to improving the sealing and insulation properties between the stack and the frame.

(f) Examples The method of the present invention is shown in Figure 1 and Figure 2. ),
These adjacent frame bodies are elastically connected to each other and the battery stack (2) is tightened from the outer periphery. This elastic coupling means (
(not disclosed) is Japanese Patent Application Laid-open No. 58-19 related to the applicant's application C.
7679 and Japanese Unexamined Patent Publication No. 61-116769, details C2 are shown, so the explanation thereof will be omitted.

These sealing surfaces (two recesses (4) C) of the frame (1) are.

A gasket (5) made of vulcanized fluororubber (product name Paiton Rubber, Buslas Rubber) is fitted, and three semicircular grooves (6) adjacent to each other are inserted into this gasket (5).
61 (61) is formed, and ring-shaped unvulcanized fluorine rubber (71 (71 and (8)) is fitted into these grooves.

Both sides (=a pair of unvulcanized fluororubber f7 located) (7
) and the unvulcanized fluorine-based rubber (8) located in the center are raw rubber [ ; The type of sulfurizing agent (curing agent) - raw and organic peroxide - to be mixed in is different from raw rubber (8) in order to create a difference in vulcanization temperature. different,
As the vulcanizing agent, the former (7071 is, for example, 1-1 ditanylbutyl peroxide, 5,5)-limethylcyclohexane, and the latter (8)C is, for example.

Contains ditetrabutyl bar tau oxide isoglobylbenzene.

Such a sealing member t31'p - each attached frame body (1
) is temporarily tightened (-next tightening), the three strips of unvulcanized fluorine rubber (7) (71 and (8) are attached to the battery stack (2)
in close contact with the sealing surface. In this case, since the unvulcanized rubber has flexibility like raw rubber, it absorbs the unevenness of the stack surface and exhibits good sealability. This state is shown in FIG.

The unvulcanized rubber is vulcanized by raising the temperature L of the battery stag (2). When the stack temperature reaches 160"CC, hold the temperature for about 20 minutes and the unvulcanized rubber (71 (7
1 is vulcanized, but the unvulcanized rubber (8) in the center is not yet vulcanized. In this state, main tightening (secondary tightening) of the frame (11) is performed, and the force is applied to the stack surface (= pressing the vulcanized rubber (7) (2. Unvulcanized rubber (8) in the center) Compress. Next, raise the temperature of the stack +21, and when it reaches about 180℃ (-), maintain that temperature for about 20 minutes, and the unvulcanized rubber in the center (
8) is also vulcanized. This state is shown in Figure 2, where the rubber (7), (7) and (8) after vulcanization are integrated into a gaskerato (
Together with 5), it constitutes a sealing member (3).

The temperature increase of the stack can be carried out by external heating at the time of starting the battery and by the heat of subsequent battery reaction.

In section 1, (9) indicates the manifold, and the opening (■) indicates the hole material between the manifold and the frame.

(G) Effects of the Invention As described above, according to the present invention ζ, the three strips of fluorocarbon rubber on the frame sealing surface are in an unvulcanized state with good flexibility when the frame is temporarily tightened on the battery stack surface (two Because they are in close contact, they absorb the unevenness of the stack surface and have good adhesion.In addition, these unvulcanized fluorine-based rubbers are first vulcanized on one pair on both sides, and then after the final tightening (the middle rubber is Since it is vulcanized and integrated, the effective sealing area can be increased.

In addition, these three strips of fluorocarbon rubber are attached to the frame via a gasket made of vulcanized fluorocarbon rubber, which improves the sealing and insulation properties between the stack and the frame. .

[Brief explanation of the drawing]

1 and 2 are sectional views of essential parts of a battery showing one embodiment of the method of the present invention, and FIG. 1 shows the first step. FIG. 2 shows respective state diagrams of the second step. FIG. 3 is a sectional view of a main part of a conventional battery. DESCRIPTION OF SYMBOLS 1... Frame body, 2... Battery stack, 5... Seal member. 5... Gasket, 7.7... Unvulcanized fluorine rubber to be vulcanized first, 8... Unvulcanized fluorine rubber to be vulcanized later.

Claims (2)

[Claims] (1) A fuel cell sealing method comprising elastically connecting manifold mounting frames that are in contact with each peripheral surface of a battery stack via a sealing member, and tightening the stack from the outer periphery, the method comprising: Three adjacent grooves are formed on the surface of the gasket made of vulcanized fluorocarbon rubber fitted to the body, and O-ring-shaped unvulcanized fluorocarbon rubber is fitted into each of these grooves, and the unvulcanized three grooves are fitted into the grooves. After temporarily tightening the frame so that the fluorine-based rubber comes into close contact with the stack surface, first vulcanize the pair of unvulcanized rubber located on both sides, then after final tightening of the frame, vulcanize the unvulcanized rubber in the middle. A method for sealing a fuel cell, characterized in that the sealing member is formed by vulcanizing rubber and integrating the three components. (2) The fuel cell sealing method according to claim 1, wherein the heating for vulcanization is performed by raising the temperature of the stack at the time of starting the battery.