JP2006012529A - Manufacturing device of fuel cell separator and manufacturing method of fuel cell separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing device having high productivity, preventing breakage of a fuel cell separator, and efficiently taking out the separator in the manufacturing method of the fuel cell separator using a lower mold having an air ejector. <P>SOLUTION: The manufacturing device of the fuel cell separator is comprised of an upper mold having a pattern of many recessed and projecting shapes and the lower mold having a pattern of many recessed and projecting shapes corresponding to the upper mold, and the lower mold has a plurality of air ejectors ejecting gas into the inside of the lower mold. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a fuel cell separator manufacturing apparatus and manufacturing method, and in particular, a manufacturing apparatus and a fuel cell separator that can be removed without damaging the fuel separator using an air ejector when being removed from a mold after molding. It relates to the manufacturing method.

In general, a polymer electrolyte fuel cell has a structure in which an electrolyte membrane is sandwiched between an anode and a cathode made of gas diffusion electrodes, and the outside is sandwiched between separators. The separator in contact with the anode supplies hydrogen gas to the anode, and the separator in contact with the cathode supplies oxygen as oxidant gas to the cathode.
The fuel cell separator is required to have gas impermeability, conductivity and surface accuracy that do not allow hydrogen gas or oxygen gas to permeate, that is, high thickness accuracy, and the performance of the fuel cell is improved due to their superior performance.
Conventional fuel cell separators are manufactured by mixing carbon powder and liquid or powdered synthetic resin to produce a raw material, which is pressurized and heated using a press or injection molding machine and a mold. For example, the separator formed in the lower mold is separated from the mold by, for example, pushing up an ejector pin and taken out.
However, when separating the molded separator with the force of the ejector pin from the mold, a considerable force is required. Therefore, when a material with relatively low toughness is molded by the force of the ejector pin, cracking of the separator, There is a problem that deformation occurs. Further, a stepped portion of about 0.2 mm may be formed as a trace on the molded separator.

Therefore, after molding the fuel cell separator without using the ejector pin, the gas is blown to the periphery of the separator to separate the separator from the mold, and then the separator is taken out by a suction device. Has been proposed (see Patent Document 1).
However, this manufacturing method does not clearly indicate what kind of material the suction device can be taken out and under what conditions. For example, the joint surface of the suction device may be a commonly used metal or If they are made of resin, the material is rigid, so that there is a problem that even if the suction device is gently joined to the fuel cell separator, the separator will break even if there is a slight strain on the surface. Further, if the joining surface of the suction device is rigid, the degree of adhesion with the fuel cell separator is lowered, and therefore, the degree of adsorption is low and the efficiency is poor even when suctioned. Further, since air is blown from above the molded fuel cell separator, the peeling effect by air is not sufficient, and the productivity is not high.

JP 2001-143722 A

  The present invention relates to a method of manufacturing a fuel cell separator using a lower mold having an air ejector, which is highly productive and can efficiently take out the separator without damaging the fuel cell separator. An object of the present invention is to provide a manufacturing apparatus for carrying out the manufacturing method.

The present invention comprises an upper mold having a large number of concave / convex patterns and a lower mold having a number of concave / convex patterns corresponding to the upper mold. The present invention relates to a fuel cell separator manufacturing apparatus having a plurality of ejectors.
The present invention also relates to the above manufacturing apparatus having a plurality of air ejectors for blowing gas into the upper mold.

  Further, the present invention is to mold a powdery raw material or prepreg between upper and lower molds, pressurize and heat, mold the mold, release the upper and lower molds, and place the lower part on the bottom of the molded fuel cell separator. The present invention relates to a method of manufacturing a fuel cell separator, characterized in that gas is blown out from a mold air ejector, the fuel cell separator is released from the lower mold, and the fuel cell separator is taken out.

  The present invention can provide a fuel cell separator manufacturing apparatus and a manufacturing method with high production efficiency without damaging the fuel cell separator by providing an air ejector capable of ejecting air to the lower mold. .

In the fuel cell separator manufacturing apparatus according to the present invention, the air ejector is installed in the lower mold or further in the upper mold, and the interior thereof is pressurized with gas so that the air ejector is interposed between the molds. A fuel cell separator formed by generating a gap and blowing gas out of the gap can be taken out by releasing it from the mold.
As the air ejector, a main body having a front end portion to be engaged with the lower mold or the surface portion of the upper mold, and capable of moving the front end portion up and down by pressurizing gas at the rear portion. The thing which consists of parts can be raised.
Such a main body portion can raise a tip having a spring that applies a force to the tip portion toward the inside of the mold and locks the tip portion to the surface portion of the lower die and the upper die. However, it can operate | move so that it may diverge from the surface part of a lower metal mold | die and an upper metal mold | die by applying a gas pressure from the back of this main-body part.
In addition, the main body portion is a piston that locks the tip portion on the surface portion of the lower die and the upper die by applying force to the tip portion in the outward direction of the lower die and the upper die. The tip part may be separated from the surface part of the lower mold and the upper mold by applying gas pressure to the piston member in the inner direction of the lower mold and the upper mold. Can be operated as follows.

Next, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to this drawing.
FIG. 1 is a view showing a main part of a fuel cell separator manufacturing apparatus according to the present invention. The apparatus shown in FIG. 1 mainly includes an upper mold installed in a press machine, a lower mold having an air ejector for blowing out gas, and a suction device.
The upper mold 1 has an uneven upper mold pattern 2 that forms the upper surface of the fuel cell separator on its lower surface. One lower mold 3 is also integrated with a frame mold part, and has an uneven upper mold pattern 4 that forms the lower surface of the fuel cell separator on the upper surface, and an air ejector that blows out gas on the lower surface. 5 These concavo-convex patterns mainly include gas passages and cooling fluid passages, and are formed in the center of the mold so that the periphery of the upper and lower molds is flat. The patterns 2 and 4 are formed on the center portion of each side of the molded fuel cell separator. It is also possible to use a mold in which either the upper mold 1 or the lower mold 3 is not formed, that is, a mold in which one mold is flat. In this case, the molded fuel cell separator has an uneven pattern formed on only one side. Although not shown, an air ejector that blows out gas can be installed in the upper mold 1, and in that case, the air ejector is formed in the same manner as the lower mold 3.

The air ejector 5 is provided inside the lower mold 3 and is engaged with the surface of the lower mold so that the fuel cell separator material does not enter the lower mold 3 when the fuel cell separator is molded. It consists of a part 6 and a body part 7 that acts so that the tip part can be moved up and down by gas pressure. As the air ejector 5, for example, as shown in FIG. 2, the front end portion 6 has a tapered shape with a narrow width in the body portion direction, and is fitted into the lower mold 3 when the fuel cell separator is molded. The body part 7 that is slightly movable upward from the lower mold 3 at the time of mold release and that is connected to the tip part receives a downward stress by a spring 8 that is locked to the lower mold 3. When the fuel cell separator is released, the fuel cell separator is pushed up by the pressure of the gas from the back of the main body, and is ejected between the fuel cell separator and the lower mold 3 molded from the gap between the lower mold 3 and the tip. When the gas is filled, the fuel cell separator can be easily peeled off. As another example of the air ejector 5, as shown in FIG. 3, the main body portion 7 connected to the distal end portion 6 includes a piston member 10 having an O-ring 9, and the lower and upper portions of the piston member are airtight. The fuel cell separator is molded by bringing the tip into contact with the opening of the lower mold 3 having a narrow opening on the upper side by pressurizing gas from the rear of the main body, and after molding, It is also possible to use a device in which the tip is pushed down by blowing gas into the upper part of the piston member, and the gas is ejected from the gap between the generated lower mold 3 and the tip.
At least two, and preferably four, air ejectors are provided in the lower mold 3, and their tip portions are usually circular and may be angular. The position of the air ejector 5 in the lower mold 3 is not particularly limited, but may be, for example, a corner of the lower mold 3, and preferably a portion corresponding to the opening of the molded fuel cell separator (immediately after molding). Is the position of the lower mold where there is an opening and becomes a part to be cut out after removing the fuel cell separator from the mold. When the air ejector is installed in the upper mold 1, the position of the air ejector 5 is preferably the same position as the lower mold 3.

  The gas ejected from the air ejector 5 is not particularly limited, but is usually air, and is preferably heated to reduce the temperature drop of the mold. The ejection pressure is preferably about 10 to 1000 kPa, more preferably about 100 to 500 kPa.

  As a preferable fuel cell separator device of the present invention, there is one having an adsorbing device 11 in addition to the upper and lower molds 1 and 3 as shown in FIG. As shown in FIG. 6, the adsorption device 11 has an adsorption member 13 that adsorbs on the surface of at least two corners 17 of the fuel cell separator 14. There are preferably four such adsorbing members, connected to the main body of the adsorbing device 11, and a hole 19 for sucking gas is formed at the center thereof. The adsorbing member 13 does not necessarily have to be joined to the surface of the corner portion 17 of the fuel cell separator 14, and can be joined to the flat portion of the separator other than the uneven pattern portion if no distortion occurs when sucked. . However, in order to reduce the distortion of the fuel cell separator that is taken out, the adsorbing member is preferably joined to the surfaces of at least two, preferably four corners 17 of the fuel cell separator 14.

  FIG. 4 is a state diagram in which the adsorbing member 13 of the adsorbing device 11 is adsorbed to the surface of the corner 17 of the typical fuel cell separator 14 shown in FIG. Since the adsorbing member 13 has an appropriate bending strength based on the material, the adsorbing member 13 can be effectively adsorbed to the corner 17 of the fuel cell separator 14.

  In the present invention, as shown in FIG. 7, it is preferable that the adsorption surface of the adsorption device 11 is composed of a sheet layer 18 made of an elastomer material, and it is not always necessary to be a corner of the adsorption surface. A suction device 11 having a suction hole 19 can also be used. Note that the adsorption device 11 having the adsorption member 13 described above is preferable to the adsorption device because the adsorption efficiency to the fuel cell separator 14 is higher.

In order to achieve good adsorption to the adsorption surface of the adsorption device 11, that is, the fuel cell separator in which the adsorption member 13 and the sheet layer 18 are molded, the adsorption member 13 preferably has a flexural modulus of 10 to 1000 MPa, more preferably Is a flexural modulus of 10 to 500 MPa.
The material for the adsorption surface is not particularly limited, and examples thereof include elastomers such as synthetic rubber, natural rubber, fluororubber, acrylic rubber, polyvinyl chloride elastomer, and polyurethane elastomer. More preferred are fluororubber and silicone rubber from the viewpoint of heat resistance.

  The suction device 11 is supported by a fixed part such as a press device, and can be moved in the left-right direction and the vertical direction in FIG. The size of the suction device 11 needs to be within the frame of the lower mold 3. In addition, the suction member 13 installed on the lower surface of the suction device 11 and the gas suction hole 19 formed in the sheet layer 18 are connected to a suction pump or the like (not shown), so that the suction device 11 contacts the lower surface. The fuel cell separator that is present can be adsorbed. In the manufacturing apparatus of the present invention, a gas blowing nozzle that blows a gas having a pressure such as compressed air on the periphery of the uneven pattern of the lower mold 3 can be installed.

Next, a method for producing the fuel cell separator of the present invention will be described.
First, in FIG. 1, the suction device 10 is moved between the upper and lower molds, the gap between the upper mold 1 and the lower mold 3 is opened, and the raw material of the fuel cell separator 14 is put on the lower mold 3. To do. Examples of such raw materials include a granulated fuel cell separator in which phenol resin, epoxy resin, and vinyl ester resin are mixed in a weight ratio of 95: 5 to 60:40 with respect to graphite having an average particle diameter of 10 to 1000 μm. A compound can be used. Further, a prepreg obtained by preforming such a compound in advance can also be used as a raw material.
After filling the raw materials, the upper mold 1 is stacked, and the mold is held at a temperature of 100 to 350 ° C. and a molding pressure of 2 to 100 MPa for about 5 minutes to mold a fuel cell separator 14 of, for example, 200 mm × 200 mm × 3 mm.
Then, the upper die 1 is separated from the lower die 3, and the lower part of the fuel cell separator in which compressed gas (air) having an original pressure of 100 to 1000 kPa is molded from the air ejector 5 of the lower die 3 shown in FIG. The fuel cell separator is released from the lower mold 3.
At this time, since the fuel cell separator 14 is thin and fragile, the pressure of the gas to be blown out is adjusted so as not to be damaged.
Thereafter, as shown in FIG. 1, the adsorption device 11 is moved onto the lower mold 3, the adsorption member 13 is brought into light contact with the fuel cell separator 14, and suction is performed at a negative pressure of 30 to 101.3 kPa. Then, the fuel cell separator 14 is sucked. At that time, the fuel cell separator 14 is separated from the lower mold 3 and attracts to the adsorption member 13 of the adsorption device 11. In this state, the adsorption device 11 is raised, the suction device is moved to another place, the suction is stopped, and the molded fuel cell separator 14 is accommodated.
Also, depending on the shape of the separator, molding conditions, etc., the mold may be opened when the mold is opened, with the molded separator attached to the upper mold side, and the molded product may fall and be damaged. In order to prevent this phenomenon, it is preferable to use a fuel cell separator manufacturing apparatus in which the upper die 1 is also provided with an air ejector. That is, the mold is blown into the upper die 1 by ejecting air from the mold release side onto the upper surface of the molded fuel cell separator several seconds before the mold is opened. After opening and then releasing the upper mold 1, the fuel cell separator is taken out from the lower mold 3 as described above.

A fuel cell separator was manufactured using the apparatus shown in FIG.
A total of 20 parts by weight of a vinyl ester resin, a curing agent, a thickener, and an additive were added to and mixed with 80 parts by weight of graphite powder. This mixture was aged for 24 hours at room temperature to increase the viscosity.
The obtained material was preformed into a square shape with a thickness of 1 cm, set in the center of a mold (200 × 200 mm) shown in FIG. 1, and pressurized for 5 minutes under conditions of a mold temperature of 140 ° C. and a pressure of 30 MPa.
After the mold was opened, air was ejected from the air ejector 5 of the lower mold 3 of FIG. 2 to the lower part of the molded product at a pressure of 300 kPa. The molded product was lifted up and separated from the lower mold. Thereafter, the molded product was taken out using a take-out device.
The apparatus used for taking out was a shape in which four adsorbing members having a diameter of 15 mm were attached to an adsorbing apparatus of 195 × 195 mm (see FIG. 6), and a fluororubber member having an elastic modulus of 100 MPa was used as the adsorbent. By applying a negative pressure of 85 kPa to this adsorbing member, the molded product was adsorbed and taken out.
When the product was taken out, there was no dropout of the molded product, and the molded product was free from problems such as cracking.

It is a schematic diagram which shows the principal part of the manufacturing apparatus of the fuel cell separator of this invention. It is a fragmentary sectional view which shows an example of the lower die air ejector of the manufacturing apparatus of the fuel cell separator of this invention, (a) is a state figure at the time of shaping | molding of a fuel cell separator, (b) is the molded fuel cell. The state figure at the time of mold release of a separator is shown. It is a fragmentary sectional view which shows an example of the lower die air ejector of the manufacturing apparatus of the fuel cell separator of this invention, (a) is a state figure at the time of shaping | molding of a fuel cell separator, (b) is the molded fuel cell. The state figure at the time of mold release of a separator is shown. It is the state figure which attracted | sucked the fuel cell separator which the suction device of the manufacturing apparatus of the fuel cell separator of this invention shape | molded. It is a top view which shows an example of the fuel cell separator shape | molded by this invention. It is a top view which shows an example of the suction device of the manufacturing apparatus of the fuel cell separator of this invention. It is a top view which shows the other example of the suction device of the manufacturing apparatus of the fuel cell separator of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper mold 2 Upper mold pattern 3 Lower mold 4 Upper mold pattern 5 Air ejector 6 Tip part 7 Body part 8 Spring 9 O-ring 10 Piston member 11 Adsorption device 12 Arm 13 Adsorption member 14 Fuel cell separator 15 Recessed part Pattern 16 Opening 17 Corner 18 Sheet layer 19 Gas suction hole

Claims (14)

It consists of an upper mold having a large number of uneven patterns and a lower mold having a large number of uneven patterns corresponding to the upper mold, and the lower mold has a plurality of air ejectors for blowing gas into the inside. A fuel cell separator manufacturing apparatus. The said air ejector is installed in the said lower metal mold | die, pressurizes the inside with gas, a gap | interval is produced between this lower metal mold | die or this upper metal mold | die, and gas is blown out from the gap | interval. Equipment for manufacturing fuel cell separators. 3. The air ejector includes a main body portion having a front end portion that is engaged with a surface portion of the lower mold and capable of moving the front end portion up and down by pressurizing gas at a rear portion thereof. The fuel cell separator manufacturing apparatus as described. The main body portion has a spring that applies a force to the tip portion toward the inside of the mold and locks the tip portion to the surface portion of the lower die, and the tip portion is formed from the rear of the main body portion. 4. The fuel cell separator manufacturing apparatus according to claim 3, wherein the apparatus separates from the surface portion of the lower mold by applying pressure with gas. The main body portion is composed of a piston member that locks the front end portion to the surface portion of the lower mold by applying a force to the front end portion in the external direction of the lower mold, and the front end portion is the piston. 4. The fuel cell separator manufacturing apparatus according to claim 3, wherein the member is separated from the surface portion of the lower mold by applying a gas pressure to the member in the inner direction of the lower mold. 6. The fuel cell separator manufacturing apparatus according to claim 1, wherein the air ejector is installed at a corner of the lower mold. 7. The fuel cell separator manufacturing apparatus according to claim 1, wherein the air ejector is installed in the lower mold portion that forms a portion corresponding to the opening of the fuel cell separator to be molded. The apparatus for producing a fuel cell separator according to any one of claims 1 to 7, further comprising an adsorption device for taking out the molded fuel cell separator. The apparatus for manufacturing a fuel cell separator according to any one of claims 1 to 8, comprising a plurality of air ejectors for blowing gas into the upper mold. The fuel cell separator manufacturing apparatus according to claim 9, wherein the upper die includes the air ejector according to claim 2. The apparatus for manufacturing a fuel cell separator according to claim 10, wherein the air ejector in the upper mold has the main body of claim 4 or 5. Put the material for the fuel cell separator between the upper and lower molds, press and heat to mold, release the upper mold after molding, and blow out the gas from the air ejector of the lower mold to the bottom of the molded fuel cell separator A method for producing a fuel cell separator, wherein the fuel cell separator is released from the lower mold, and then the fuel cell separator is taken out. Put the material for the fuel cell separator between the upper and lower molds, pressurize and heat to mold, release the upper and lower molds after molding, and gas from the lower mold air ejector to the bottom of the molded fuel cell separator A method for producing a fuel cell separator, characterized in that the fuel cell separator is released from the lower mold by blowing out, and then the adsorbing device is adsorbed on the upper surface of the fuel cell separator to take out the fuel cell separator. Put fuel cell separator material between upper and lower molds, pressurize and heat to mold, blow out gas from upper mold air ejector to upper part of molded fuel cell separator, then upper mold The fuel cell separator is characterized in that gas is blown out from the lower mold air ejector to the bottom of the molded fuel cell separator, the fuel cell separator is released from the lower mold, and the fuel cell separator is taken out. Manufacturing method.

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