JP2006185667A - Molding method and molding device of metal separator for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding device of a metal separator for a fuel cell which has a superior manufacturing cost and in which contact resistance can be reduced. <P>SOLUTION: This molding device has a first molding die 140 in which a cavity 142 having a recessed part and a convex part in order to form a flow passage groove of a first reaction gas is installed and in which a first metal plate material 241 is arranged, has a second molding die 110 corresponding to the recessed part and the convex part of the first molding die 140 in which the cavity 112 having the convex part and the recessed part for forming the passage groove of a second reaction gas is installed and which is arranged opposite to the first molding die 140, has a pressing means 170 in order to mold-clamp the first molding die 140 and the second molding die 110 and to simultaneously press the first metal plate material 241 and a second metal plate material 251 which is arranged opposite to the second molding die 110 and which is superposed on the first metal plate material 241, and has a retaining member 180 in order to retain the difference between the recessed part of the cavity 142 of the first molding die 140 and the convex part of the cavity of the second molding die 110 corresponding to the recessed part and in order to form a passage of the cooling fluid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a molding method and a molding apparatus for a fuel cell metal separator.

A single cell of a fuel cell has a separator for separating fuel gas and oxidant gas. Since a metal material has excellent strength even when it is thin, it has been tried to be applied to a separator, and two metal plates having concave and convex portions corresponding to flow channel grooves are laminated. Thus, a separator is formed (see, for example, Patent Document 1 and Patent Document 2).
JP 2002-373673 A JP 2003-331859 A

  However, since the concave and convex portions of the metal plate are formed by pressing, there is a spring back. Therefore, when a separator is formed by superimposing two metal plates, there is a problem that a contact resistance increases due to a gap formed on the mating surface of the convex portions of the metal plate. On the other hand, when the deformation due to the spring back is corrected, the number of processes increases, and the manufacturing cost increases.

  The present invention has been made in order to solve the above-described problems associated with the prior art, and provides a molding method and a molding apparatus for a fuel cell metal separator that have good manufacturing costs and can reduce contact resistance. With the goal.

In order to achieve the above object, the invention described in claim 1
A molding method for producing a metal separator applied to a single cell of a fuel cell,
A first metal plate is disposed in a first mold provided with a cavity having a concave portion and a convex portion for forming a flow channel for the first reactive gas;
The first metal is opposed to the second mold provided with a cavity having a convex part and a concave part for forming a channel groove for the second reactive gas corresponding to the concave part and the convex part of the first mold. Place the second metal plate on top of the plate,
When the first mold and the second mold are clamped and the first metal plate and the second metal plate are pressed at the same time, the cavity corresponds to the recess of the first mold and the recess. The cooling fluid flow path is formed while maintaining the difference between the convex portion of the cavity of the second molding die.

In order to achieve the above object, the invention according to claim 9 provides:
A molding apparatus for producing a metal separator applied to a single cell of a fuel cell,
A first mold in which a cavity having a concave portion and a convex portion for forming a flow channel for the first reactive gas is provided, and a first metal plate material is disposed;
Corresponding to the concave and convex portions of the first mold, a cavity having a convex portion and a concave portion for forming a flow channel for the second reactive gas is provided, and is disposed relative to the first mold. Second mold,
The first molding die and the second molding die are clamped, and the first metal plate material and a second metal plate material disposed opposite to the second molding die and superimposed on the first metal plate material Pressing means for pressing simultaneously, and
A holding member for holding a difference between the concave portion of the cavity of the first mold and the convex portion of the cavity of the second mold corresponding to the concave portion, and forming a cooling fluid flow path; Is a molding apparatus characterized by

  The present invention configured as described above has the following effects.

  According to the first aspect of the present invention, the first and second metal plate members are pressed at the same time to form the concave portion and the convex portion. Even if the mating surfaces of the convex portions are in close contact with each other and then spring back occurs, the contact resistance is deformed in the same manner, thereby suppressing an increase in contact resistance. Therefore, it is not necessary to correct the deformation by the springback, and it is possible to avoid an increase in process and an increase in manufacturing cost. In addition, since the difference between the concave portion of the cavity of the first mold and the convex portion of the cavity of the second mold corresponding to the concave portion is held at the time of pressing, the flow path of the cooling fluid is not formed. It ’s unimpeded. Therefore, it is possible to provide a method of forming a metal separator for a fuel cell that has a good manufacturing cost and can reduce contact resistance.

  According to invention of Claim 9, it is possible to form a recessed part and a convex part by pressing the 1st and 2nd metal plate material simultaneously. In this case, even if the mating surfaces of the convex portions are brought into close contact with each other and then spring back occurs, an increase in contact resistance is suppressed by similarly deforming. Therefore, it is not necessary to correct the deformation by the springback, and it is possible to avoid an increase in process and an increase in manufacturing cost. Further, since the difference between the concave portion of the cavity of the first mold and the convex portion of the cavity of the second mold corresponding to the concave portion is held by the holding member at the time of pressing, the flow of the cooling fluid The formation of the path is not hindered. Therefore, it is possible to provide a metal separator molding device for a fuel cell that has a good manufacturing cost and can reduce the contact resistance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view for explaining a fuel cell and a separator according to an embodiment of the present invention, and FIG. 2 is a plan view of the separator shown in FIG.

  The fuel cell 10 is in the form of a stack formed by laminating a large number of single cells, and is used as, for example, a drive source for an automobile. The single cell is a battery that can obtain electricity in the process of obtaining water by reacting hydrogen and oxygen by utilizing the reverse principle of electrolysis of water, and has an electrode portion 20 and a metal separator 30.

  The electrode part 20 is arrange | positioned between the metal separators 30, and has a solid polymer electrolyte membrane and the gas diffusion layer arrange | positioned on both surfaces.

  The metal separator 30 has a central flow path portion 32 in which the flow path grooves are disposed, and end portions 33 located on both sides of the flow path portion 32. Openings 34, 35, and 36 for circulating hydrogen and oxygen as reaction gases and water as a cooling fluid are disposed at the end 33.

  The metal separator 30 is composed of two stacked plates (upper layer plate 41 and lower layer plate 51). The upper layer plate 41 and the lower layer plate 51 have convex portions 42 and 52 and concave portions 46 and 56, and exhibit an uneven shape. The material of the upper layer plate 41 and the lower layer plate 51 is, for example, a stainless steel plate. Stainless steel plates are preferred because they are easy to perform complex machining and have good electrical conductivity. The stainless steel plate can be coated with a corrosion-resistant coating as necessary. An aluminum plate or a clad material can also be applied.

The upper surface 43 of the convex portion 42 of the upper layer plate 41 is in contact with the lower surface of the electrode portion 30 located above. The space S ₁ defined by a lower surface of the upper surface 47 and the electrode portion 30 of the recess 46 forms a channel groove for flowing the fuel gas (hydrogen).

The upper surface 53 of the convex portion 52 of the lower layer plate 51 is in contact with the lower surface 44 of the convex portion 42 of the upper layer plate 41. The lower surface 54 of the convex portion 52, the space S ₂ defined by the upper surface of the electrode portion 30 positioned below forms a flow channel for circulating the oxidizing gas (air). The lower surface 58 of the recess 56 is in contact with the upper surface of the electrode unit 30 located below.

The depth of the concave portion 56 of the lower layer plate 51 is set to be larger than the depth of the concave portion 56 of the upper layer plate 41, and the lower surface 58 of the concave portion 56 of the upper layer plate 41 and the upper surface of the concave portion 56 of the lower layer plate 51. space S ₃ defined by a 57 forms a channel groove for flowing the cooling water. The space S ₃ is located below the flow channel groove (space S ₁ ) for allowing the fuel gas (hydrogen) to flow through the concave portion 56 of the upper layer plate 41.

The adjacent metal separators 30 are arranged with the concave and convex portions offset. Therefore, the flow channel groove (space S ₂ ) for flowing the oxidant gas of the metal separator 30 is a flow channel groove for flowing the fuel gas of the adjacent metal separator 30 through the electrode part 30 located above. It is opposed to (space S ₁ ) and a channel groove (space S ₃ ) for circulating cooling water. On the other hand, the flow channel groove (space S ₁ ) for circulating the fuel gas of the metal separator 30 and the flow channel groove (space S ₃ ) for circulating the cooling water are adjacent to each other via the electrode portion 30 positioned below. This is opposed to a channel groove (space S ₂ ) for allowing the oxidizing gas of the metal separator 30 to flow through.

The shape and arrangement of the spaces (flow channel grooves) S _{1 to} S ₃ are appropriately set in consideration of gas diffusibility, pressure loss, generated water discharge, cooling performance, and the like.

  3 is a side view for explaining the molding apparatus according to the embodiment of the present invention, FIG. 4 is a plan view for explaining the molding die shown in FIG. 3, and FIG. 5 is shown in FIG. FIG. 6 is a cross-sectional view taken along a line VI-VI in FIG. 3.

  The molding apparatus 100 includes an upper mold (second molding mold) 110, a lower mold (first molding mold) 140, a pressing device (pressing means) 170, and a spacer (holding member) 180.

  The upper mold 110 is disposed so as to be able to approach and separate from the lower mold 140, and has an upper flow path die 111 and an upper end die 121 corresponding to the flow path section 32 and the end section 33 on the upper surface of the metal separator 30. The upper flow path die 111 and the upper end die 121 and the holder part 135 disposed around are connected to and supported by the support part 130.

  The cavity 112 of the upper flow path die 111 has a convex portion 113 and a concave portion 114 for forming a fuel gas flow channel. The convex portion 113 corresponds to the concave portion 46 of the upper layer plate 41, and the concave portion 114 corresponds to the convex portion 42 of the upper layer plate 41. The upper flow path die 111 is divided into five.

  The lower mold 140 is disposed in a fixed manner, and has a flow path portion 32 corresponding to the lower surface of the metal separator 30 and a lower flow path die 141 and a lower end die 151 corresponding to the end portion 33. The lower flow path die 141 and the lower end die 151 and the holder part 165 disposed around are connected to and supported by the support part 160.

  The cavity 142 of the lower flow path die 141 has a convex part 143 and a concave part 144 for forming a channel groove for oxidizing gas. The convex portion 143 corresponds to the concave portion 56 of the lower layer plate 51, and the concave portion 144 corresponds to the convex portion 52 of the lower layer plate 51.

  The convex portion 113 and the concave portion 114 of the cavity 112 of the upper flow path die 111 and the concave portion 144 and the convex portion 143 of the cavity 142 of the lower flow path die 141 of the lower mold 140 are arranged offset. That is, the convex portion 143 and the concave portion 144 correspond to the concave portion 114 and the convex portion 113 of the upper mold 110. The lower flow path die 141 is divided into five.

  A lower blank material (first metal plate material) 241 and an upper blank material (second metal plate material) 251 are disposed in the cavities 142 and 152 of the lower flow path die 141 and the lower end die 151 of the lower mold 140. The lower blank material 241 and the upper blank material 251 constitute the lower layer plate 51 and the upper layer plate 41 of the metal separator 30. The upper blank member 251 is positioned so as to be opposed to the upper flow path die 111 of the upper mold 110 and the cavities 112 and 122 of the upper end die 121 and overlap the lower blank member 241.

  The pressing device 170 has a driving device for moving the support portion 130 of the upper mold 110 toward the lower mold 140, and clamps the upper mold 110 and the lower mold 140 to lower the lower blank material 241 and the upper blank material 251. Are simultaneously pressed. The drive device is, for example, a hydraulic cylinder.

  Therefore, the lower blank plate 241 is pressed by the convex portions 143 and the concave portions 144 of the cavity 142 of the lower flow path die 141, thereby forming the lower layer plate 51 having the convex portions 52 and the concave portions 56 corresponding to the convex portions 143 and the concave portions 144. It is possible to form. Further, by pressing the upper blank material 251 with the convex portions 113 and the concave portions 114 of the cavity 112 of the upper flow path die 111, the upper layer plate 41 having the convex portions 42 and the concave portions 46 corresponding to the convex portions 113 and the concave portions 114 is obtained. It is possible to form.

  The spacer 180 holds a difference between the concave portion 144 of the cavity 142 of the lower flow channel die 141 and the convex portion 113 of the cavity 112 of the upper flow channel die 111 corresponding to the concave portion 144 to form a cooling fluid flow channel. Used to do. The material of the spacer 180 is not particularly limited as long as it has an appropriate strength, and metal, ceramic, resin, or the like can be applied. The resin is an engineering plastic such as PEEK (polyether ether ketone resin).

  The spacer 180 is disposed between the lower blank material 241 and the upper blank material 251 and is positioned corresponding to the concave portion 144 of the cavity 142 of the lower flow path die 141. The spacer 180 has a substantially rectangular cross section, and its corners are chamfered to correspond to the bent shape of the corners of the recess 144.

  The sum of the thickness of the spacer 180 and the height of the convex portion 113 of the cavity 112 of the upper flow path die 111 substantially matches the depth of the concave portion 144 of the cavity 142 of the lower flow path die 141. Since a plurality of spacers 180 are installed corresponding to the recesses 144 of the cavity 142 of the lower flow path die 141, they are integrated for easy handling. Integration is performed by connecting the end portions 181 of the spacers 180.

  Accordingly, the molding apparatus 100 can press the lower blank material 241 and the upper blank material 251 simultaneously to form the concave portions 46 and 56 and the convex portions 42 and 52. In this case, even if the mating surfaces of the convex portions 42 and 52 are in close contact with each other and then spring back occurs, the contact resistance is increased in a similar manner, thereby suppressing an increase in contact resistance. Therefore, it is not necessary to correct the deformation by the springback, and it is possible to avoid an increase in process and an increase in manufacturing cost.

  Further, the difference between the concave portion 144 of the cavity 142 of the lower flow path die 141 and the convex portion 113 of the cavity 112 of the upper flow path die 111 corresponding to the concave portion 144 is held by the spacer 180 at the time of pressing. Therefore, the formation of the cooling fluid channel is not hindered.

  Next, the molding method according to the embodiment of the present invention will be described. 7 is a cross-sectional view for explaining the placement of the lower blank material and the upper blank material, FIG. 8 is a cross-sectional view for explaining pressing following FIG. 7, and FIG. 9 is a mold following FIG. FIG. 10 is a cross-sectional view for explaining the opening of the separator, following FIG. 9.

  The lower blank material 241 is disposed in the cavities 142 and 152 of the lower flow path die 141 and the lower end die 151 of the lower mold 140. The spacer 180 is placed on the lower blank material 241 and positioned corresponding to the concave portion 144 of the cavity 142 of the lower flow path die 141. The upper blank member 251 is positioned so as to overlap with the lower blank member 241 on which the spacer 180 is placed, relative to the upper flow path die 111 of the upper die 110 and the cavities 112 and 122 of the upper end die 121. (See FIG. 7).

  The pressing device 170 moves the support portion 130 of the upper mold 110 toward the lower mold 140, thereby clamping the upper mold 110 and the lower mold 140, and simultaneously pressing the lower blank material 241 and the upper blank material 251. .

  The lower blank material 241 is pressed by the convex portion 143 and the concave portion 144 of the cavity 142 of the lower flow path die 141, and is formed into the lower layer plate 51 having the convex portion 52 and the concave portion 56 corresponding to the convex portion 143 and the concave portion 144. The upper blank member 251 is pressed by the convex portion 113 and the concave portion 114 of the cavity 112 of the upper flow path die 111 and is formed into the upper layer plate 41 having the convex portion 42 and the concave portion 46 corresponding to the convex portion 113 and the concave portion 114 ( (See FIG. 8).

  Since the lower blank member 241 and the upper blank member 251 are pressed at the same time to form the concave portions 46 and 56 and the convex portions 42 and 52, the mating surfaces of the convex portions 42 and 52 are brought into close contact with each other. Even if it occurs, an increase in contact resistance is suppressed by deformation in the same manner. Therefore, it is not necessary to correct the deformation by the springback, and it is possible to avoid an increase in process and an increase in manufacturing cost.

  After the molding is completed, the pressing device 170 moves the support portion 130 of the upper mold 110 away from the lower mold 140, whereby the upper mold 110 and the lower mold 140 are opened (see FIG. 9). The spacer 180 is removed (see FIG. 10).

  The spacer 180 holds a difference between the concave portion 144 of the cavity 142 of the lower flow path die 141 and the convex portion 113 of the cavity 112 of the upper flow path die 111 corresponding to the concave portion 144 when pressed. Therefore, the space occupied by the spacer 180 can constitute a flow path for the cooling fluid. That is, the formation of the cooling fluid channel is not hindered.

  As described above, the present embodiment can provide a molding method and a molding apparatus for a fuel cell metal separator that have good manufacturing costs and can reduce contact resistance.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims.

  For example, the upper mold upper flow channel die and the lower mold lower flow channel die can be integrated. In addition, the spacer can be a free end without connecting one end to facilitate removal.

It is sectional drawing for demonstrating the fuel cell and separator which concern on embodiment of this invention. It is a top view of the separator shown by FIG. It is a side view for demonstrating the shaping | molding apparatus which concerns on embodiment of this invention. It is a top view for demonstrating the shaping die shown by FIG. It is a top view for demonstrating the spacer shown by FIG. FIG. 4 is a cross-sectional view taken along line VI-VI in FIG. 3. It is sectional drawing for demonstrating the shaping | molding method which concerns on embodiment of this invention, and has mounted mounting of the lower blank material and the upper blank material. FIG. 8 is a cross-sectional view for explaining pressing following FIG. 7. It is sectional drawing for demonstrating mold opening following FIG. FIG. 10 is a cross-sectional view for explaining separator removal following FIG. 9.

Explanation of symbols

10. Fuel cell,
20 .. Electrode part,
30 ... Metal separator,
32. ・ Flow path part,
33..End,
34, 35, 36 .. opening,
41 .. Upper layer plate,
42 .. convex part,
43..Upper surface,
44 .. Lower side,
46 .. recess,
47 .. Upper surface,
48 .. Lower side,
51..Lower plate,
52 .. Convex part,
53 .. upper surface,
54 .. Lower side,
56 .. recess,
57..Upper surface,
58 .. lower surface,
100. ・ Molding equipment,
110 .. Upper mold,
111 .. Upper flow path die,
112 .. cavity,
113 .. Convex part,
114 .. recess,
121 .. Upper end die,
122 .. cavity
130 .. support part,
135 .. Holder part,
140 ... lower mold,
141..Lower flow path die,
142 .. cavity,
143 .. convex part,
144 .. Recess,
151 .. Lower end die,
152 .. cavity,
160 .. support part,
165 .. Holder part,
170 .. Pressing device,
180 .. spacer
181 ... the end,
241, lower blank material,
251 ... Upper blank material
S ₁ , S ₂ , S ₃ .. space.

Claims (16)

A molding method for producing a metal separator applied to a single cell of a fuel cell,
A first metal plate is disposed in a first mold provided with a cavity having a concave portion and a convex portion for forming a flow channel for the first reactive gas;
The first metal is opposed to the second mold provided with a cavity having a convex part and a concave part for forming a channel groove for the second reactive gas corresponding to the concave part and the convex part of the first mold. Place the second metal plate on top of the plate,
When the first mold and the second mold are clamped and the first metal plate and the second metal plate are pressed at the same time, the cavity corresponds to the recess of the first mold and the recess. The molding method is characterized in that the difference between the second molding die and the convex portion of the cavity of the second molding die is maintained to form a cooling fluid flow path.   2. The molding method according to claim 1, wherein one and the other of the first reaction gas and the second reaction gas are hydrogen gas and oxygen gas, and the cooling fluid is water.   The difference is held by a spacer disposed between the first metal plate material and the second metal plate material, and the spacer is positioned corresponding to the concave portion of the cavity of the first mold. The molding method according to claim 1, wherein:   The molding method according to claim 3, wherein the spacer has a substantially rectangular cross section.   The molding method according to claim 4, wherein the corner portion of the spacer has a bent shape.   The sum of the thickness of the spacer and the height of the convex portion of the cavity of the second mold is substantially the same as the depth of the concave portion of the cavity of the first mold. Item 6. The molding method according to Item 5.   The molding method according to claim 3, wherein the spacer includes a plurality of pieces and is integrated.   The molding method according to claim 7, wherein the spacers are integrated by connecting end portions. A molding apparatus for producing a metal separator applied to a single cell of a fuel cell,
A first mold in which a cavity having a concave portion and a convex portion for forming a flow channel for the first reactive gas is provided, and a first metal plate material is disposed;
Corresponding to the concave and convex portions of the first mold, a cavity having a convex portion and a concave portion for forming a flow channel for the second reactive gas is provided, and is disposed relative to the first mold. Second mold,
The first molding die and the second molding die are clamped, and the first metal plate material and a second metal plate material disposed opposite to the second molding die and superimposed on the first metal plate material Pressing means for pressing simultaneously, and
A holding member for holding a difference between the concave portion of the cavity of the first mold and the convex portion of the cavity of the second mold corresponding to the concave portion, and forming a cooling fluid flow path; A molding apparatus characterized by.   The molding apparatus according to claim 9, wherein one and the other of the first reaction gas and the second reaction gas are hydrogen gas and oxygen gas, and the cooling fluid is water.   The holding member is a spacer disposed between the first metal plate material and the second metal plate material, and the spacer is positioned corresponding to the concave portion of the cavity of the first mold. The molding apparatus according to claim 9 or 10.   The molding apparatus according to claim 11, wherein the spacer has a substantially rectangular cross section.   The molding device according to claim 12, wherein a corner portion of the spacer has a bent shape.   The sum of the thickness of the spacer and the height of the convex portion of the cavity of the second mold is substantially the same as the depth of the concave portion of the cavity of the first mold. Item 14. The molding apparatus according to Item 13.   The molding apparatus according to claim 11, wherein the spacer includes a plurality of spacers and is integrated.   The molding apparatus according to claim 15, wherein the spacer is integrated by connecting end portions.

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