KR20110061005A - Method of forming gasket and injection mold for manufacturing the gasket - Google Patents

Abstract

PURPOSE: A gasket molding method and a gasket injection mold for a fuel cell are provided to produce a gasket without damage of a separator plate by preventing direct pressure and impact exerted on the separator plate during injection-molding. CONSTITUTION: In a gasket molding method in which a separator plate(10) is arranged between an upper mold(30) and a lower mold(20) and a rubber material is injected through an injection part(40) to integrally form a gasket on the top surface of the separator plate, the rubber material injected through the injection part is stored in a first chamber(50) separated from the separator plate and the rubber material is charged into the first chamber by being transferred to a second chamber(70) through a channel(60).

Description

Gasket Forming Method and Fuel Cell Gasket Injection Mold {Method of Forming Gasket and Injection Mold for manufacturing the Gasket}

The present invention relates to a gasket molding method, and more particularly, to a method for integrally molding a gasket on the surface of the separator plate provided in the stack of the fuel cell.

In general, a fuel cell is a system that generates power by using hydrogen and oxygen as a reverse reaction of water electrolysis. Fuel cells have a variety of forms, but the most commonly used forms of fuel cells are proton exchange membranes (PEMs).

Conventional fuel cells produce relatively low voltages, and therefore, to produce enough to be available as power, a fuel cell stack must be assembled from tens to hundreds of fuel cells.

1 is a cross-sectional view showing an example of a fuel cell stack, and as shown in the figure, is composed of a plurality of unit cells composed of a membrane electrode assembly, a separator plate 100, and a gasket 130.

The membrane electrode assembly includes a polymer electrolyte membrane 120 for selectively transporting hydrogen ions, a fuel electrode 121 and a cathode 122 which are a pair of electrodes formed on both surfaces of the polymer electrolyte membrane. The anode and the cathode include a catalyst layer formed on the surface of the polymer electrolyte membrane, and a gas diffusion layer formed on the outer surface of the catalyst layer and having both breathability and electron conductivity.

Around the fuel electrode 121 and the air electrode 122, a gasket 130 sealing is disposed so that the fuel gas and the oxidant gas supplied to the electrode do not leak to the outside or the two kinds of gases are not mixed with each other. do.

An outer side of the membrane electrode assembly is provided with a conductive separator plate (130). The separator is made of a thin graphite material and mechanically fixes the membrane electrode assembly, and electrically connects the adjacent membrane electrode assemblies in series or in parallel with each other. For this purpose, a groove-shaped gas flow path 110 is provided. Can be molded.

In forming the gasket 130 on the separator plate 100, an integrated molding method for injection molding directly onto the separator plate using a liquid rubber material has been developed and is being carried out.

2 is a cross-sectional view showing a conventional gasket forming method. As shown, the separation plate 100 is disposed between the upper mold 300 and the lower mold 200, and the liquid rubber is injected at a high pressure through the injection unit 400 provided in the upper mold.

The upper mold 300 is provided with a chamber 600 to the upper side of the separation plate 100, the liquid rubber injected directly into the upper surface of the separation plate through the injection unit 400 is the chamber through the passage 500 Is introduced into the gasket to form the gasket.

Conventional liquid rubber (Liquid Rubber) is an amorphous polymer having an average molecular weight of more than thousands, it is excellent in fluidity can be shaped relatively simply as described above, but the durability has a short lifespan limitations.

Accordingly, it is preferable to prepare a gasket using a fluororubber having excellent heat resistance and durability as a synthetic rubber of a polymer containing fluorine. In particular, in the case of phosphoric acid fuel cells, other materials other than fluorine rubber cannot be used as gasket materials due to chemical reactions.

However, since fluorine rubber does not have a liquid rubber, a solid rubber having excellent flowability should be used, and as described above, the separator may be damaged when directly injected into the surface of the thin separator. That is, in the conventional method, there is a problem in that integral molding is impossible due to breakage of the separator plate when forming a gasket using fluorine rubber.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a gasket molding method capable of integrally forming a gasket made of fluororubber on a separator plate, and a gasket injection mold for fuel cell performing the molding method. have.

Gasket manufacturing method according to an embodiment of the present invention for achieving the above object, the separation plate is disposed between the upper mold and the lower mold, injecting a flowable rubber material through the injection portion gasket on the upper surface of the separation plate In the integrated molding method, the rubber material injected through the injection portion is stored in the first chamber at a position spaced apart from the separation plate, the rubber material injected into the first chamber is passed through the separation plate It is moved to the second chamber provided on the upper surface of the filling to prevent direct pressure and impact on the separator.

At this time, the passage is connected horizontally between the first chamber and the second chamber to configure a smooth flow of the rubber material.

On the other hand, in the fuel cell gasket injection mold according to another aspect of the present invention, the separator plate is disposed between the upper mold and the lower mold, and the fluid rubber material is injected through the injection unit to integrally mount the gasket on the upper surface of the separator plate. A separating plate integrated gasket injection mold for molding, comprising a first chamber, a second chamber, and a passage.

The first chamber is formed at a position spaced apart from the separation plate, and primarily stores the rubber material injected through the injection portion.

The separator is inserted into the second chamber, and the gasket is formed.

The passage communicates between the first chamber and the second chamber, and is formed on an upper surface of the separation plate.

In this case, the passage is a horizontal connection between the first chamber and the second chamber, it may be formed along the upper surface of the separation plate.

According to the present invention having the configuration as described above, in integrally molding the gasket of the fluororubber material on the surface of the separator plate, unlike the prior art, it is possible to prevent the direct pressure and impact generated in the separator plate during the injection process The gasket can be molded without damaging the separator.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view showing a gasket forming method according to the present invention. As shown, the separation plate 10 is disposed between the upper mold 30 and the lower mold 20, and the flowable rubber material is injected through the injection part 40 provided in the upper mold.

The rubber material injected through the injection part 40 is stored in the first chamber 50 formed between the upper mold 30 and the lower mold 20 at a position spaced apart from the separator 10. The rubber material stored in the first chamber is filled and moved to the second chamber 70 provided on the upper surface of the separation plate 10 through the passage 60 by the injection pressure.

That is, the rubber material injected at high pressure through the injection part 40 is first stored in the first chamber 50 inside the mold, and then moved to the second chamber 70 contacting the surface of the separating plate 10 to be stored second. In this way, the impact applied during injection is absorbed in the first chamber, thereby minimizing the impact applied to the separator.

Therefore, as described above, even in the case of fluorine rubber, in which there is no liquid rubber and a solid rubber having excellent flowability is used, the gasket can be integrally formed without damaging the separation plate unlike the conventional art.

At this time, the passage 60 is preferably connected horizontally so that the rubber material injected into the first chamber 50 can flow smoothly into the second chamber 70, one side is connected to the upper end of the first chamber , The other side is configured to be connected to the lower end of the second chamber.

Hereinafter, an injection mold apparatus providing the above molding method will be described.

Referring to FIG. 3, an injection mold providing a method for forming a gasket for a fuel cell of the present invention includes an upper mold 30, a lower mold 20, and an injection part 40.

The upper mold and the lower mold 30 and 20 are joined together to form a second chamber 70 which is a molding space at the time of joining. Specifically, the upper mold and the lower mold 30, 20 is the first and second molding grooves are formed on the surface facing each other to make the second chamber 70 as a whole. At this time, the second chamber 70 has a shape corresponding to a gasket which is a desired shape of a molding to be molded by an injection mold.

A first chamber 50 is included between the upper mold 30 and the lower mold 20. The first chamber 50 is interposed between the first and second molds 10 and 20 and communicates with the second chamber 70 through a passage 60.

The first chamber 50 serves as a kind of gate. That is, the first chamber 50 forms a supply passage of the rubber material in communication with the second chamber 70. In order to install the first chamber 50, the upper mold and the lower mold 30, 20 are formed with first and second supply grooves extending from the first and second molding grooves forming the molding space. Be sure to

As it is provided to extend with the first and second forming grooves, the first and second supply grooves communicate with the side of the second chamber 70. Therefore, the rubber material inserted into the first and second supply grooves communicates with the molding space side.

In the present embodiment, the first chamber 50 may have a quadrangular shape or a trapezoidal shape as shown in the drawings, and may be provided in pairs with a molding space therebetween. However, the illustrated embodiment does not necessarily limit the structure of the first chamber 50, and it is natural that the first chamber 50 may be provided in singular or three or more, or may have a deformation such as having a funnel shape. .

For reference, the injection mold apparatus described in this embodiment may be applied to a three-stage system or a two-stage system having a pin point for supplying a rubber material.

 By this configuration, if the upper and lower molds are separated from each other after the rubber material is molded by the injection mold in the molding space, the mill pin enters through the mill pin groove to lift the rubber material and at the same time, the first passage 50 The gasket injection is completed as is broken.

In the above, certain preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art without departing from the gist of the present invention described in the claims.

1 is a cross-sectional view showing an example of a fuel cell stack.

Figure 2 is a cross-sectional view showing a conventional gasket forming method.

Figure 3 is a cross-sectional view showing a gasket forming method according to the invention.

Description of the Related Art [0002]

10: separator 20: upper mold

30: lower mold 40: injection portion

50: first chamber 60: passage

70: second chamber

Claims (6)

In the method of arranging the separator plate between the upper mold and the lower mold, injecting a flexible rubber material through the injection portion to integrally mold the gasket on the upper surface of the separator plate, The rubber material injected through the injection part is stored in the first chamber at a position spaced apart from the separation plate, Gasket forming method characterized in that the rubber material inside the first chamber is moved to the second chamber provided on the upper surface of the separation plate through a passage. The method of claim 1, And said passage connects said first chamber and said second chamber horizontally. The method of claim 2, The passage is a gasket forming method, characterized in that one side is connected to the upper end of the first chamber, the other side is connected to the lower end of the second chamber. The method according to any one of claims 1 to 3, Gasket molding method characterized in that using the synthetic rubber of the polymer containing fluorine as the rubber material. A separator plate integrated gasket injection mold for disposing a separator plate between an upper mold and a lower mold, and injecting a flexible rubber material through an injection part to integrally form a gasket on an upper surface of the separator plate. A first chamber formed at a position spaced apart from the separation plate and configured to primarily store a rubber material injected through the injection portion; A second chamber in which the separator is inserted and which is a space where the gasket is formed; And And a passage formed in an upper surface of the separation plate to communicate between the first chamber and the second chamber. The method of claim 5, The passage is a horizontal connection between the first chamber and the second chamber, the fuel cell gasket injection mold, characterized in that formed along the upper surface of the separator.

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