JP4482413B2 - Manufacturing method of fuel cell separator - Google Patents

Description

  The present invention relates to a method for manufacturing a separator for a fuel cell comprising a sealing material on upper and lower surfaces of an edge of a separator body in a polymer electrolyte fuel cell.

Conventionally, a method for manufacturing a separator for a fuel cell in which a sealing material is integrally formed on the upper and lower surfaces of the edge of the separator body has been proposed (see, for example, Patent Document 1).
JP 2002-237317 A (FIG. 17)

Patent document 1 is demonstrated based on the following figure.
FIG. 12 is a diagram for explaining the basic configuration of the prior art. By sandwiching the separator body 103 between the lower mold 101 and the upper mold 102 and injecting a molten sealing material through the gates 105 and 105, the edge of the separator body 103 is formed. The sealing material 106 is integrally formed.
The separator main body 103 in which warpage, undulation, or distortion has occurred is placed in the mold, and the separator main body 103 is pressed in the mold with the holding metal fittings 107, 108, 109, 110 to correct the warpage, undulation, or distortion. And

Since the presser fittings 107 to 110 are an accessory of the lower mold 101 and the upper mold 102, when the upper mold 102 is opened, a trace that the presser fittings 107 to 110 have been removed is partly covered with the sealing material 106. Remains in the form of a hole.
Since these holes are not preferable from the viewpoint of insulation, etc., it is necessary to fill the holes in the subsequent process.
For this reason, in the technique of patent document 1, manufacturing cost increases.

  An object of the present invention is to provide a method of manufacturing a separator for a fuel cell that does not require a hole filling operation in a subsequent process when a sealing material is injected on both surfaces of the separator body and integrally molded.

According to a first aspect of the present invention, there is provided a method for manufacturing a separator for a fuel cell including a sealing material on upper and lower surfaces of an edge of a separator body, wherein a plurality of holding members are provided on at least one surface of the upper and lower surfaces of the separator body. Placing the separator body provided with the holding member into an injection mold having a cavity for forming a sealing material at a position corresponding to the edge of the separator body, and to the cavity of the injection mold A step of injecting the sealing material to integrally form the sealing material in the separator body, and a step of opening the mold and taking out the separator body with the sealing material embedded in the holding member. It has a thickness corresponding to the thickness of the sealing material in the portion where the holding member is disposed .

  The invention according to claim 2 is characterized in that the sealing material is silicone rubber, and the holding member contains silicon or a silicon compound.

  The invention according to claim 3 is characterized in that the holding member is a sphere having a diameter corresponding to the thickness of the sealing material.

The invention according to claim 4 is characterized in that the holding member is a U-shaped cross-section piece in which portions disposed on the upper surface and the lower surface of the edge of the separator body are connected to each other at the edge of the separator .

In the invention according to claim 5, in the step of arranging a plurality of holding members on at least one of the upper and lower surfaces of the edge of the separator main body, a part of the plurality of holding members arranged is the edge of the separator main body. The portions disposed on the upper and lower surfaces of the separator are U-shaped cross-section pieces connected to each other at the edge of the separator, and the remainder is a sphere having a diameter corresponding to the thickness of the sealing material of the portion where the holding member is disposed. Features.

  In the invention according to claim 1, the separator is a separator in which a plurality of holding members corresponding to the thickness of the sealing material are arranged on at least one of the upper and lower surfaces of the edge of the separator body, and these holding members are arranged. Is set in an injection mold, molten sealing material is injected, the sealing material is integrally formed, and the separator body with the sealing material is taken out from the injection mold.

  The holding member attached to the edge of the separator body is buried in the sealing material without being removed from the sealing material. Therefore, no hole remains in the sealing material, and no work for filling the hole occurs. Since the hole filling work is unnecessary, there is an advantage that the manufacturing cost can be reduced.

In the invention according to claim 2, since silicone rubber is used for the sealing material, there is an advantage that effects of insulation, heat resistance, water repellency, aging resistance and chemical resistance can be obtained.
In addition, since the holding member contains silicon or a silicon compound, it contains the same components as the sealing material, which is silicone rubber to be injection molded, and the sealing material and the holding member can be blended, and the seal There is an advantage that a preferable joint between the material and the holding member can be obtained.

  In the invention which concerns on Claim 3, since a holding member is a spherical body, there exists an advantage that a holding member can be easily arrange | positioned to the predetermined position of a separator main body.

Further, since the holding member is a sphere, the height from the separator body can be set to a constant value.
As a result, there is an advantage that a pressing force can be uniformly applied between a plurality of holding members attached at predetermined positions.

In the invention according to claim 4, since the holding member is a U-shaped cross-sectional piece having a height corresponding to the total vertical height of the sealing material, the upper and lower surfaces of the separator body can be held at the same time. A separator without distortion can be obtained by molding.
As a result, there is an advantage that the manufacturing cost can be further reduced.

  In the invention which concerns on Claim 5, since the holding member was made into the combination of the spherical body and the U-shaped cross-sectional piece, there exists an advantage that the separator with higher thickness accuracy of a sealing material can be obtained.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a diagram illustrating a process of arranging a spherical holding member on the separator body according to the present invention. In this step, as shown in (c), spherical holding members 16... (... indicates a plurality. The same applies hereinafter) are regularly arranged on the upper surface 12 of the separator body 11. For this purpose, a chip jig 18 (a) and a plate jig 21 (b) are prepared.

  As shown in (a), the chip jig 18 has set holes 19... For setting spherical holding members 16... (Hereinafter also referred to as chips 17...) On the surface 18 a. In addition, it is a jig that can set the spherical chips 17 in the set holes 19.

  The chip jig 18 is provided with positioning post holes 23 and 23 at positions where the positioning jigs 22 and 22 provided on the lower plate jig 21 are fitted, and air is provided below the set holes 19. Suction air outlets 24 for suction are provided, and connection holes 25 are provided downward from the suction air outlets 24, and are connected to the connection holes 25 in a horizontal direction. Is provided. The piping 27 drawn out from the outlet of the collecting hole 26 is connected to a vacuum pump (not shown).

In order to set the chips 17... In the chip jig 18, the set holes 19... Provided on the surface 18 a of the chip jig 18 are directed upward, and the chips are directed toward these set holes 19. The chips 17 are set so as to be arranged at the predetermined positions shown in FIG. 5C by sucking air from the suction outlets 24.
In this embodiment, the extra chip that does not enter the set holes 19 is a sphere, and can be easily removed by shaking the chip jig 18.

  In order to remove excess chips, the chips may be blown off with air, or the chip jig 18 may be inclined, and the removal method is arbitrary.

Next, the separator body 11 is set on the plate jig 21 of (b), and the chip jig 18 indicated by an imaginary line is aligned.
Specifically, the positioning post 22 of the plate jig 21 on which the separator body 11 is placed, with the surface 18a of the chip jig 18 facing downward while sucking air so that the chips 17... The positioning post holes 23, 23 of the chip jig 18 are overlapped with 22.

It is assumed that an adhesive or a primer for bonding the chip 17 by contact with the chip 17 is applied to the upper surface 12 of the separator body 11 in advance.
After the chip jig 18 is overlaid on the plate jig 21, air suction is stopped from the suction outlets 24..., The restriction of the chips 17. Attach the tip 17. In order to attach the chips 17 to the upper surface 12 of the separator body 11, air is blown out from the suction outlet 24 toward the set holes 19.

(C) shows the separator body 11 taken out from the plate jig 21.
In this way, by using the chip jig 18, it is possible to easily arrange a plurality of chips 17... As a sphere at predetermined positions.

That is, since the holding member is a sphere, the holding member can be easily disposed at a predetermined position of the separator body 11.
Along with this, the height from the separator body 11 can be made constant without variation. Accordingly, it is possible to apply a pressing force uniformly to each of the holding members attached to a predetermined position in the post-process injection mold.

In addition, by adding a process, it is possible to attach the spherical holding member 16 to the lower surface 13 in addition to the upper surface 12 of the separator body 11. In this case, since the spherical holding members 16 are attached to the both surfaces 12 and 13 of the separator body 11, the both surfaces 12 and 13 of the separator body 11 can be simultaneously injection molded.
That is, a plurality of spherical holding members 16 having a diameter or thickness corresponding to the thickness of the sealing material can be arranged on at least one of the both surfaces 12, 13 of the edge 11a of the separator body 11.

  In the present embodiment, the spherical holding member 16 is a sphere, but is not limited to this shape. For example, a rectangular parallelepiped or a cube may be used.

  2 is a cross-sectional view taken along line 2-2 of FIG. 1 and shows a state in which a spherical holding member 16 (hereinafter sometimes referred to as a chip 17) is attached to the edge 11a of the separator body 11. FIG. Since the adhesive (or primer) is applied to the upper surface 12 of the separator body 11 in advance, the chip 17 can be fixed to the upper surface 12.

The injection process following the process of arranging the holding member as described above will be described in order below.
FIG. 3 is a view showing that the separator body provided with the holding member according to the present invention is set in the injection mold. First, the separator body 11 with the spherical holding member 16 attached to the first lower mold 42 is set. The upper mold 43 is placed. The upper mold 43 is provided with gates 44 and 45 for injecting molten sealing material, and injected from a cylinder (not shown) for supplying the molten sealing material to the gates 44 and 45 via runners 46 and 47 serving as supply paths. It is a mold that can do.
When the upper mold 43 is aligned with the first lower mold 42, that is, when the injection mold 41 is closed, the spherical holding member 16 attached to the separator body 11 contacts the cavity 51 of the upper mold 43.

FIG. 4 is an explanatory view of resin injection according to the present invention.
First, the conditions for injection molding in this example are set as follows.
Sealing material injection pressure: 1.5 to 10 MPa (150 to 1000 kg / cm ² )
Injection mold temperature: 373-473K (100-200 ° C)
Seal material: Silicone rubber Separator holding member: Resin or rubber elastic body

In (a), a molten sealing material is injected into the cavity 51 through the gate 44 using a cylinder (not shown). When the sealing material is solidified, the first lower mold 42 is removed from the upper mold 43.
In (b), the second mold 54 is aligned with the upper mold 43, and the molten sealing material is injected into the cavity 52 through the gate 45 using a cylinder (not shown).

  At this time, since the holding member 16 attached to the separator body 11 is brought into contact with the cavity 51 of the upper mold 43 and the separator body 11, the separator body 11 is not warped, swelled, or distorted.

More specifically, since a plurality of spherical holding members 16 having a diameter or thickness corresponding to the thickness of the sealing material 14 are arranged on at least one of the upper and lower surfaces of the edge 11a of the separator body 11, the mold When the separator main body 11 is disposed therein, warping, undulation, and distortion generated in the separator main body 11 can be corrected by pressing with the holding member 16. Originally, since the separator body 11 is extremely thin, the warp or the like is usually left on the upper and lower surfaces. However, the warp remaining on the upper and lower surfaces can be obtained by arranging a plurality of spherical holding members 16. Can be corrected before molding.
As a result, a separator 15 in which the sealing material 14 is coated with a constant thickness is obtained.

The sealing material 14 is silicone rubber, and the holding member contains silicon or a silicon compound.
Since silicone rubber is used as the sealing material, effects of insulation, heat resistance, water repellency, aging resistance and chemical resistance can be obtained.

In addition, since the spherical holding member 16 contains silicon or a silicon compound, the spherical holding member 16 contains the same components as the silicone rubber that is the sealing material to be injection-molded, and between the sealing material 14 and the holding member 16. A preferred bond is obtained.
In addition, after the spherical holding member 16 is arranged, a primer containing silicon or a silicon compound is applied to the surface of the spherical holding member 16 and injection molding of the molten sealing material is performed, so that the sealing material 14 and the spherical holding member 16 are further spherical. It is also possible to improve the bonding with the holding member 16.

  FIG. 5 is a mold opening view of the mold according to the present invention. The upper die 43 and the second lower die 54 are separated from each other, and the separator body 11 on which the sealing material 14 is formed is connected to the upper die 43 and the second lower die 54. Take out from the injection mold 41 provided.

  FIG. 6 is a completed view of the separator according to the present invention. A spherical holding member 16 is attached to a part of the separator main body 11, and the spherical holding member 16 is molded to become a part of the sealing material 14. Thus, a separator in which the sealing material is coated to a certain thickness can be manufactured.

  Thus, the spherical holding member 16 attached to the edge 11 a of the separator body 11 is embedded in the sealing material 14 without being removed from the sealing material 14. Therefore, no hole remains in the sealing material 14, and no work for filling the hole occurs. Since the hole filling operation is unnecessary, the manufacturing cost can be reduced.

Furthermore, this hole filling operation is a manual operation, and defects may occur due to excessive application of material or application of material to a place other than the hole, but the operation itself is not necessary.
As a result, the occurrence of defects related to the holes can be prevented.

FIG. 7 is a view showing that the U-shaped cross-section piece according to the present invention is arranged on the edge of the separator body. Specifically, in the step of preparing a plurality of U-shaped cross-section pieces 61 having a height corresponding to the total vertical height H of the sealing material 14, a predetermined number of U-shaped cross-section pieces 61 are prepared.
Next, in the step of arranging the prepared U-shaped cross-sectional piece 61 on the edge 66 of the separator main body 11B, the prepared U-shaped cross-sectional piece 61 is disposed on the edge 11a of the separator main body 11.
The sealing material 14 is silicone rubber, and the U-shaped cross-section piece 61 is a member containing silicon or a silicon compound.

FIG. 8 is a view showing that a separator body provided with a U-shaped cross-section piece according to the present invention is set in an injection mold.
By setting the U-shaped cross-section piece 61 in place of the spherical holding member of FIG. Distortion can be corrected and molten sealing material can be injected.

Specifically, in the step of setting the separator body with the U-shaped cross-section piece in the injection mold, the separator body 11B with the U-shaped cross-section piece 61 is set on the lower mold 62 and the upper mold 64 is covered.
Next, in the step of injecting resin into the cavity 63 of the injection mold 60 including the upper mold 64 and the lower mold 62 and integrally molding the sealing material 14B into the separator body 11B, the molten sealing material is injected.

  Finally, in the step of opening the mold and taking out the separator body 11B with the sealing material 14B, the upper die 64 is opened and the integrally formed separator 15B is taken out.

8 differs from FIG. 4 in that the upper surface 61a of the U-shaped cross-section piece 61 is brought into contact with the cavity 63 of the upper mold 64, and the lower surface 61b of the U-shaped cross-section piece 61 is brought into contact with the cavity 65 of the lower mold 62. Structure. 68 is a runner and 69 is a gate.
A U-shaped cross-sectional piece 61 having a height corresponding to the total vertical height H of the sealing material 14 is fitted to the edge 66 of the separator main body 11B, and the separator main body 11B with the U-shaped cross-sectional piece 61 is set in the injection mold 60. After that, a molten sealing material is injected into the cavities 63 and 65 of the injection mold 60.

Thus, the U-shaped cross-section piece 61 set on the edge 66 of the separator main body 11B is a member embedded in the separator, so that no hole remains in the covering portion, and a hole filling operation for filling the hole can be made unnecessary.
As a result, there is an advantage that the manufacturing cost can be reduced.
Since the work itself becomes unnecessary, there is no possibility that a defect related to the hole occurs.

Since the upper and lower surfaces 12B and 13B of the separator main body 11B can be simultaneously held by the U-shaped cross-section piece 61, a separator in which a sealing material is coated on both surfaces of the separator can be obtained by a single injection molding.
As a result, the manufacturing cost can be reduced.

Further, since the U-shaped cross-sectional piece 61 contains silicon or a silicon compound, the U-shaped cross-sectional piece 61 contains the same components as the sealing material that is silicone rubber to be injection-molded. Bonding is obtained.
Furthermore, after the U-shaped cross-section piece 61 is disposed, a primer containing silicon or a silicon compound is applied to the surface of the U-shaped cross-section piece 61, and the bonding between the sealing material and the U-shaped cross-section piece 61 is further performed. It is also possible to improve.

Figure 9 is a complete view of the separator arranged a U-shaped cross section piece according to the present invention, placing the edge 66 in a U-shaped cross section piece 61 of the separator body 11B, the U-section piece 61 of the sealing member 14B one It is molded to be a part.
By the above manufacturing method, the fuel cell separator 15B including the sealing material 14B on the upper and lower surfaces 12B and 13B of the edge 66 of the separator body 11B can be manufactured.

FIG. 10 is a view of another embodiment of FIG. 8, and the spherical holding member 16 is a combination of a spherical body 72 that is also the spherical holding member 16 and a U-shaped cross-sectional piece 61.
In the method for manufacturing a fuel cell separator, the spherical holding member 16 is attached to the separator body 11C, and then a U-shaped cross-section piece 61 is attached to the separator body 11C.
73 is an upper mold, 74 is a lower mold, 76 is a runner, and 77 is a gate.

The spherical holding member 16 is attached by placing a plurality of spherical holding members 16 described in FIG. 1 on the separator main body 11C, and the U-shaped cross-section piece 61 on the edge 71 of the separator main body 11C described in FIG. And performing the placing step.
In addition, the process of setting the separator main body described in FIG. 8 to the injection mold and the process of injecting the molten sealing material are basically the same and will not be described.

  The order in which the U-shaped cross-sectional piece 61 is attached to the separator main body 11C and then the spherical holding member 16 is attached may be employed.

FIG. 11 is a diagram showing another embodiment of FIG. 9, in which a spherical holding member 16 is placed on the upper surface 12C of the separator body 11C, a U-shaped cross-sectional piece 61 is disposed on the edge 71, injection molding is performed, and the sealing material 14C is formed. Form. A spherical holding member 16 and a U-shaped cross-section piece 61 are formed so as to be a part of the sealing material 14C.
The holding member can obtain a separator having a higher sealing material thickness by appropriately combining a sphere and a U-shaped cross-sectional piece.

  The present invention is suitable for manufacturing a fuel cell separator.

It is a figure explaining the process of arrange | positioning a spherical holding member to the separator main body which concerns on this invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a figure which shows setting the separator main body provided with the holding member which concerns on this invention to an injection die. It is resin injection explanatory drawing which concerns on this invention. It is a mold opening figure of the metal mold | die which concerns on this invention. It is a completion drawing of the separator concerning the present invention. It is a figure which shows arrange | positioning the U-shaped cross-section piece which concerns on this invention to the edge of a separator main body. It is a figure which shows setting the separator main body provided with the U-shaped cross-section piece which concerns on this invention to an injection die. It is a completed figure of the separator which has arrange | positioned the U-shaped cross-section piece which concerns on this invention. It is another Example figure of FIG. It is another Example figure of FIG. It is a figure explaining the basic composition of the conventional technology.

Explanation of symbols

  11, 11B, 11C ... Separator body, 12, 12B, 12C ... Upper surface of separator body, 13, 13B, 13C ... Lower surface of separator body, 14, 14B, 14C ... Sealing material, 16 ... Spherical holding member, 51, 52 ... cavity, 61 ... U-shaped cross-section piece.

Claims (5)

In the manufacturing method of a separator for a fuel cell provided with a sealing material on the upper and lower surfaces of the edge of the separator body
A step of arranging a plurality of holding members on at least one of the upper and lower surfaces of the edge of the separator body;
Setting the separator body including the holding member in an injection mold including a cavity for forming the sealing material at a position corresponding to an edge of the separator body ;
Injecting the sealing material into the cavity of the injection mold and integrally molding the sealing material in the separator body;
Opening the mold and removing the separator body with the sealing material embedded with the holding member , and
The method for manufacturing a fuel cell separator , wherein the holding member has a thickness corresponding to a thickness of the sealing material at a portion where the holding member is disposed .   2. The method for manufacturing a fuel cell separator according to claim 1, wherein the sealing material is silicone rubber, and the holding member contains silicon or a silicon compound.   3. The method for manufacturing a fuel cell separator according to claim 1, wherein the holding member is a sphere having a diameter corresponding to the thickness of the sealing material. 3. The fuel according to claim 1, wherein the holding member is a U-shaped cross-section piece in which portions disposed on an upper surface and a lower surface of an edge of the separator body are connected to each other at the edge of the separator. Manufacturing method of battery separator. In the step of arranging a plurality of holding members on at least one of the upper and lower surfaces of the edge of the separator body, a part of the plurality of holding members arranged on the upper and lower surfaces of the edge of the separator body. The disposed portion is a U-shaped cross-section piece connected to each other at the edge of the separator, and the remaining portion is a sphere having a diameter corresponding to the thickness of the sealing material of the portion where the holding member is disposed. The manufacturing method of the separator for fuel cells of Claim 1 or Claim 2.

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