JP2001143722A - Manufacturing apparatus of fuel cell separator and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method that does not require much labor and deteriorate the efficiency of the apparatus in manufacturing a fuel cell separator having no trace an ejector pin, and a manufacturing apparatus for implementing the manufacturing method. SOLUTION: The manufacturing apparatus of fuel cell separator comprises an upper metal mold 21 into which the pattern 21a in the shape of rough parts corresponding to one surface of the fuel cell separator is formed, a lower metal mold 22 into which the pattern 22a of rough parts corresponding to its other surface, a suction device 23 movable between the upper and the lower metal molds, and a nozzle 25. It includes injecting a raw material a in the shape of powder between the upper and the lower metal molds 21, 22 and shapes it by pressing and heating, after shaping, separating the upper and the lower metal mold 21, 22, delaminating the fuel cell separator from the lower metal mold by spraying gas with the nozzle, entering the suction device 23 between the upper and the lower metal mold, and sucking and drawing out the fuel cell separator 1 shaped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for manufacturing a fuel cell separator, and more particularly, to removing a fuel separator without breaking it without using ejector pins when removing it from a mold after molding. The present invention relates to a manufacturing apparatus and a manufacturing method that can be used.

[0002]

2. Description of the Related Art A fuel cell using a fuel gas and an oxidizing gas, among which a polymer electrolyte fuel cell, comprises an ion-conductive solid electrolyte membrane formed of a gas diffusion electrode carrying a catalyst, an anode and a cathode. , And the outside of these is sandwiched between separators. The anode-side separator supplies hydrogen as fuel gas to the anode, and the cathode-side separator supplies oxygen as oxidant gas to the cathode.

FIG. 3 is a diagram of such a fuel cell separator. As shown in FIG.
A U-shaped thin groove 1a serving as a gas passage is formed on the plate-like surface. However, in order to increase the contact area between the gas diffusion electrode and the gas, the groove 1a meanders over almost the entire surface of the separator and is fine. It is formed with a pitch. This groove 1a corresponds to FIG.
As shown in (b), the separator may be formed on both sides, but may be formed on only one side.

[0004] In addition to the above structure, the separator is provided with projections arranged on both sides or one side thereof, and the gap between the projections serves as a gas flow path. Some have a combined structure.

[0005] The above-mentioned fuel cell separator is required to have the following properties. Gas impermeable. This means a property that does not allow the supplied hydrogen gas or oxygen gas to permeate. Normally, a fuel cell is formed by laminating a large number of units, each including a central solid polymer electrolyte membrane, gas diffusion electrodes on both sides thereof, and a separator on the outside thereof as one unit cell. Accordingly, gas flows on at least one side of one separator, and if the separator has a property of allowing gas to pass through, the power generation efficiency of the battery is reduced, or power generation itself becomes impossible and the battery is not established. That's why.

[0006] Conductive. Since the separator is an electrode of the fuel cell, conductivity is indispensable.

High surface accuracy, that is, high thickness accuracy. This is because the separator and the anode or the cathode are in contact with each other and conduct electricity, and if the surface accuracy is poor, the contact area is reduced and the conductivity is deteriorated. Further, if the surface accuracy is poor, a gap is formed between the anode and the cathode, and if a force acts in a direction in which the gap is crushed, the separator may be broken. The higher the surface accuracy, the lower the contact resistance, so that the performance of the fuel cell is improved.

In a conventional fuel cell separator, a powdery raw material is prepared by mixing a carbon powder and a synthetic resin powder, and the raw material is put into a lower die of a press machine and covered with an upper die. It was molded by pressing and heating with a press machine. Here, the term “powder-like raw material” is used as a generic term for powdery, granular, and short-fiber raw materials.

This will be further described with reference to FIG. In the figure, reference numeral 2 denotes an upper die, 3 denotes a frame die, and 4 denotes a lower die. As shown in FIG. 3A, the upper and lower molds are separated from each other,
A powdery raw material a, which is a raw material for a fuel cell separator, is put on the lower mold 4. Next, as shown in (b), the upper mold 2 is put on the lower mold 4 and the powdery raw material a is pressed and heated to form the fuel cell separator 1.

When the molding is completed, as shown in FIG. 4C, the upper mold 2 is raised, the ejector pins 5 and 5 provided on the lower mold 4 are raised, and the fuel cell separator 1 is lowered. It is moved away from the mold 4 to a position where it can be taken out.

The upper mold 2 is formed with an uneven pattern 2a on the upper surface of the fuel cell separator 1. The pattern 2a mainly includes a gas flow path for supplying a gas to the gas diffusion electrode. On the upper surface of the other lower mold 4, an uneven pattern 4 a on the lower surface of the fuel cell separator 1 is formed.

However, the pattern 2a of the upper mold is the pattern of the entire upper surface of the fuel cell separator 1, whereas the pattern 4a of the lower mold is not the pattern of the entire lower surface of the fuel cell separator 1. This is because the ejector pins 5 and 5 are provided.

FIG. 5 is an enlarged sectional view of the lower mold 4.
On the upper surfaces of the ejector pins 5 and 5 described above, the pattern 4
A pattern 5a which is a continuous portion of a is formed. In both the pattern 4a and the pattern 5a, the fuel cell separator 1
Since these are irregularities corresponding to the lower surface of the slab, a mold must be made so that the continuous portion A has no step. if,
If a step is formed, the contact with the gas diffusion electrode is deteriorated at a low place, and the performance of the battery is lowered.

However, if the ejector pins 5 are formed in one mold as described above, it is very difficult to match these joints with high accuracy on the order of 1/100 (mm). A has a step. As a result, FIG.
As shown in FIG. 7, a step portion of about 0.2 mm was formed as the ejector pin mark 1b. Further, burrs are likely to be formed at the boundary between the ejector pin 5 and the mold, which may block the gas flow path. Further, there is a problem that the rigidity of the lower mold 4 is reduced by the amount of the ejector pins 5.

To solve such a problem, a manufacturing apparatus as shown in FIG. 6 has been proposed. In this device, no ejector pin is formed on the lower mold 12.
The upper mold 11 is separated from the lower mold 12 as shown in FIG.
The raw material is put on the top, and the upper mold 11 is put thereon as shown in FIG. When the molding is completed, it is the same as the previous conventional example up to the point where the upper mold is separated. Thereafter, in this conventional example, the entire lower mold 12 is raised so that the fuel cell separator 1 can be taken out. In this conventional example, since no ejector pin is used, no ejector pin mark is formed on the molded fuel cell separator 1.

However, since the lower die 12 is moved up and down in the frame die 13, a gap s is formed between the lower die 12 and the frame die 13, into which the molten raw material enters and the lower die 1
2 will be hindered. For this reason, frequent cleaning is required, which is troublesome, and at the same time, there is a problem that the downtime of the press increases and the efficiency decreases. In addition, when the lower mold 12 is moved up and down, if the movement is poor, the mold is inclined, and in some cases, it may be stuck and may not move.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and is directed to a method of manufacturing a fuel cell separator. An object of the present invention is to provide a manufacturing method that does not damage a fuel cell separator, and a manufacturing apparatus for performing the manufacturing method.

[0018]

In order to achieve the above object, a fuel cell separator manufacturing apparatus according to the present invention comprises an upper mold having an uneven pattern corresponding to one surface of a fuel cell separator. A lower mold in which an uneven pattern corresponding to the other surface of the fuel cell separator is formed, and a method in which a gas is blown to a peripheral portion of the formed fuel cell separator to separate the fuel cell separator from the lower mold. It is characterized by having two or more nozzles, and an adsorbing device that moves between the upper and lower molds and removes the formed fuel cell separator. In principle, the upper and lower mold patterns have a configuration corresponding to the entire surface of each surface of the separator, and have no ejector pins.

Alternatively, the lower mold has a structure in which a powdery raw material for a fuel cell separator is charged, or the adsorbing device can move up and down toward the upper mold or the lower mold. It can be.

The method of manufacturing a fuel cell separator according to the present invention is directed to a method of manufacturing a fuel cell separator wherein a powdery raw material is put between upper and lower molds, pressed and heated, and molded.
After molding, the upper and lower molds are separated from each other, and gas is blown to the periphery of the formed fuel cell separator on the lower mold to separate the fuel cell separator from the lower mold. It is characterized in that the fuel cell separator is inserted and adsorbed and taken out of the molded fuel cell separator.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing a main part of a fuel cell separator manufacturing apparatus according to the present invention. The apparatus of the present invention shown in FIG. 1 is mainly composed of a mold installed in a press machine.

The upper mold 21 is the same as that described in the conventional example, and has an uneven pattern 21a for forming the upper surface of the fuel cell separator 1 on the lower surface thereof. On the other hand, the lower mold 22 has a shape in which the frame mold portion in the conventional example is also integrated, and has an uneven pattern 22 a that forms the lower surface of the fuel cell separator 1 on the upper surface. These concavo-convex patterns mainly include gas passages and cooling fluid passages. In addition, neither the upper mold 21 nor the lower mold 22 has an ejector pin. Therefore, pattern 21
Since a and 22a are respectively formed on the entire surface of each one side of the fuel cell separator 5, the operation of matching the boundary surfaces with the ejector pins becomes unnecessary. Further, the frame mold portion and the lower mold are integrated to form a space 2 for material input.
Although the gap 2b is formed, the gap s, which is a problem in the conventional example of FIG. 6, can be eliminated, so that the molten material does not enter. In particular, since the lower mold 22 has no ejector pins and is integrated with the frame mold, the rigidity is increased.

In the present invention, in addition to the upper and lower dies 21, 22, a suction device 23 and one or more nozzles 25 are provided. The suction device 23 is supported by a fixed portion such as a press device, and can be moved in the left-right direction and the up-down direction in FIG. 1 by a driving device (not shown). Although not shown, some holes are formed in the lower surface of the suction device 23. By connecting the arm / pipe 23a to a suction pump or the like (not shown), the suction device 23 comes into contact with the lower surface thereof. Can be adsorbed. The nozzle 25 blows a gas under pressure, such as compressed air, to the peripheral portion of the uneven pattern of the lower mold 22. This nozzle 25 is also driven by a driving device (not shown).
It is movable in the horizontal direction and the vertical direction in FIG. Although only one nozzle 25 may be provided, two nozzles may be provided at opposing positions, one nozzle may be provided on each side of a rectangular separator, or a continuous nozzle may be provided on the entire circumference of the separator.

FIGS. 2 (a) to 2 (c) are views for explaining a use state of the apparatus of the present invention, that is, a method for manufacturing a fuel cell separator. First, as shown in FIG. 2A, the space between the upper mold 21 and the lower mold 22 is opened, and the raw material a in the form of a powder of the fuel cell separator 1 is put into the space 22 b of the lower mold 22. As the raw material a, for example, phenol resin is added to 100 parts by weight of flaky graphite (average particle size: 30 μm).
5 parts by weight of a mixed and granulated fuel cell separator compound can be used.

When the powdery raw material a is filled in this way, the upper mold 21 is overlaid, and the mold is heated at a temperature of 160 ° C. and a molding pressure of 200
kg / cm ² for about 5 minutes, 300mm x 250
The fuel cell separator 1 of mm × 2 mmt was molded.

Then, as shown in FIG. 2B, the upper mold 21 and the lower mold 22 are separated from each other, and the nozzle 25 is moved to the lower mold 2.
2 and blows a gas such as compressed air to the periphery of the fuel cell separator 1 on the lower mold 22. The blown gas reaches the lower mold 22 through a narrow gap between the lower mold 22 and the fuel cell separator 1, and separates the fuel cell separator 1 from the lower mold 22. Although the fuel cell separator 1 is thin and brittle, it can be safely separated from the lower mold 22 without being damaged by appropriately adjusting the pressure of the gas to be blown. Thereafter, as shown in FIG. 2 (c), the suction device 23 is moved horizontally just above the lower mold 22, and is further lowered to lightly contact the fuel cell separator 1 to be sucked. The size of the suction part of the suction device 23 is 290 mm × 240 mm, which is slightly smaller than the fuel cell separator 1. Fuel cell separator 1
Is separated from the lower mold 22 and adheres to the suction device 23. In this state, the suction device 23 is raised, and is further horizontally moved from the upper part of the lower mold 22 to a storage position (not shown), and is lowered as necessary to stop suction. The fuel cell separator 1 is separated from the adsorption device 23 and taken into the accommodation place. The fuel cell separator molded in this manner had no ejector marks, and no step at that portion.

[0027]

According to the present invention as described above,
An upper mold having an uneven pattern corresponding to one surface of the fuel cell separator, a lower mold having an uneven pattern corresponding to the other surface of the fuel cell separator, and an upper and lower mold. An adsorbing device that retreats and removes the formed fuel cell separator; one or more nozzles that blow gas to the periphery of the formed fuel cell separator to separate the fuel cell separator from the lower mold; And a suction device that can move back and forth between the molds.
The molded separator can be removed from the mold by the suction device without using an ejector pin. Therefore, no ejector pin marks are left on the separator, and a separator having excellent surface accuracy can be obtained. In the above configuration, one or more nozzles may be provided, but providing a plurality of nozzles allows the fuel cell separator to be more reliably separated from the lower mold.

If the suction device is configured to be able to move up and down toward the upper die or the lower die, even if there is a height difference between the suction device and the take-out position of the die, the fuel cell after the molding is formed. The separator can be taken out without fail.

In the fuel cell separator manufactured according to the present invention, since no ejector mark is formed in the gas flow path, no trouble such as blocking the gas flow path occurs. In addition, since there is no step formed in the ejector mark, the contact between the separator and the gas diffusion electrode can be stabilized.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a main configuration of a fuel cell separator manufacturing apparatus according to the present invention.

FIG. 2 is a diagram illustrating a method for manufacturing a fuel cell separator of the present invention.

FIG. 3 is a view of a fuel cell separator, (a) is a plan view,
(B) is BB sectional drawing of (a).

FIG. 4 is a diagram illustrating a method for manufacturing a conventional fuel cell separator.

FIG. 5 is an enlarged sectional view of a lower mold of FIG. 4;

FIG. 6 is a diagram illustrating another method for manufacturing a conventional fuel cell separator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel cell separator 21 Upper mold 21a pattern 22 Lower mold 22a pattern 23 Suction device 25 Nozzle a Raw material

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Atsushi Tsuruya 1-2-3, Onodai, Midori-ku, Chiba-shi, Chiba Nisshin Spinning Co., Ltd. R & D Center (72) Inventor Yoshitaka Araki 1, Onodai, Midori-ku, Chiba-shi, Chiba 2-2-3 Nisshin Spinning Co., Ltd. Research and Development Center (72) Inventor Takashi Maki 1-2-3 Onodai, Midori-ku, Chiba City, Chiba Prefecture Nisshin Spinning Co., Ltd. Research and Development Center

Claims (3)

[Claims] An upper mold having an uneven pattern corresponding to one surface of a fuel cell separator, and a lower mold having an uneven pattern corresponding to the other surface of the fuel cell separator. One or two or more nozzles for blowing the gas to the periphery of the molded fuel cell separator to separate the fuel cell separator from the lower mold, and advance and retreat between the upper and lower molds to remove the molded fuel cell separator. An apparatus for manufacturing a fuel cell separator, comprising: an adsorbing device for extracting the fuel cell separator. 2. The apparatus for manufacturing a fuel cell separator according to claim 1, wherein the adsorption device is capable of moving up and down toward an upper mold or a lower mold. 3. A method of manufacturing a fuel cell separator, in which a powdery raw material is charged between upper and lower molds and pressurized and heated to mold the fuel cell separator, the upper and lower molds are separated after molding, and Blowing gas around the molded fuel cell separator to separate the fuel cell separator from the lower mold, inserting an adsorption device between the upper and lower molds, adsorbing and removing the molded fuel cell separator A method for producing a fuel cell separator, comprising: