WO2010047142A1

WO2010047142A1 - Generator cell of a fuel cell and manufacturing method thereof

Info

Publication number: WO2010047142A1
Application number: PCT/JP2009/058343
Authority: WO
Inventors: 諭二見; 橋本　圭二
Original assignee: トヨタ車体株式会社
Priority date: 2008-10-20
Filing date: 2009-04-28
Publication date: 2010-04-29
Also published as: JP2010153041A; JP5298758B2

Abstract

An MEA (15) is housed inside frames (13, 14). First and second gas flow path forming members (21, 22) are interposed between the anode layer (17) and the cathode layer (18) of the MEA (15) and the first and second separators (23, 24), which are secured by bonding to both the upper and lower surfaces of the frames (13,14). The gas flow path forming parts (21, 22) are formed from a lathe-cut metal (25) comprising thin sheet metal. A plurality of perforations having a prescribed shape is formed in a grid form and in a stepped form in the lathe-cut metal (25). Curved planar parts (29a) that contact the surfaces of gas diffusion layers (19, 20) are formed on rings (27), in which the respective perforations of the gas flow path forming parts (21, 22) are formed.

Description

Fuel cell power generation cell and method of manufacturing the same

The present invention relates to a power generation cell of a fuel cell including a gas flow path forming member interposed between a gas diffusion layer and a separator, and a method for manufacturing the same.

Conventionally, as a polymer electrolyte fuel cell, one disclosed in Patent Document 1 has been proposed. This fuel cell includes a fuel cell stack constituted by stacked power generation cells. The power generation cell includes a membrane-electrode assembly. The membrane-electrode assembly includes an electrolyte membrane, an anode layer formed on one surface of the electrolyte membrane, and a cathode formed on the other surface of the electrolyte membrane. It is composed of layers. By supplying a fuel gas such as hydrogen gas and an oxidant gas such as air to the anode layer and the cathode layer via a gas flow path forming member (collector), an electrode reaction occurs in the membrane-electrode assembly. It is generated and electricity is generated. The generated electricity is output to the outside through a collector and a plate-like separator.

In order to efficiently supply the fuel gas and the oxidant gas to the anode layer and the cathode layer, for example, a gas flow path forming member described in Patent Document 1 can be employed. The gas flow path forming member is made of a lath cut metal formed of a thin metal plate, and a large number of small through holes are formed in a net shape in the lath cut metal. This lath cut metal can be formed, for example, by performing lath cut processing on a stainless steel plate having a thickness of about 0.1 mm. These through-holes are formed in a hexagonal shape, for example, and the portions forming the through-holes, that is, the ring portions (strands) are connected so as to sequentially overlap, and the cross-sectional shape becomes a stepped shape. ing.
JP 2007-87768 A

In the power generation cell constituting the fuel cell stack, two gas diffusion layers are interposed between the surfaces of both electrode layers and the gas flow path forming member. The gas diffusion layer is formed of carbon paper made of conductive fibers. Fine gaps are formed in the gas diffusion layer, and the fuel gas and the oxidant gas are efficiently diffused by passing through these gaps and are appropriately supplied to both electrode layers. Here, in order to properly make electrical contact between the gas diffusion layers and the gas flow path forming member, when a plurality of power generation cells are stacked, the direction in which the two upper and lower separators of each power generation cell slightly approach each other The gas flow path forming member is pressed against the gas diffusion layer. FIG. 17 is a partial cross-sectional view of a power generation cell employing a conventional gas flow path forming member. As shown in FIG. 17, a gas flow path forming member 21 is interposed between the gas diffusion layer 19 joined to the anode layer 17 and the separator 23. In this state, when the upper and lower separators are pressed as described above, the separator 23 is pressed downward in the drawing, and the contact portion 29 of the gas flow path forming member 21 is strongly pressed against the gas diffusion layer 19. Thereby, as shown in FIG. 18, the contact portion 29 may bite into the gas diffusion layer 19.

When the contact part 29 bites into the gas diffusion layer 19 in this way, a part of the gas diffusion layer 19 is cut and broken by the contact part 29, and the function as the gas diffusion layer is lowered. Since a part of the gas flow path of the gas flow path forming member 21 is closed by the gas diffusion layer, the effective area of the gas flow path is reduced. Thereby, since the pressure loss of fuel gas increases, there also existed a problem that the supply amount of fuel gas fell and power generation efficiency fell. Further, when the carbon fiber in the gas diffusion layer is cut and flowed by the fuel gas, the fiber may adhere to the narrow gas flow path of the gas flow path forming member, and clogging may occur in the gas flow path. When clogging occurs in the gas flow path in this way, the flow of fuel gas is hindered and power generation efficiency decreases. Furthermore, since the amount of the contact portion 29 of the gas flow path forming member 21 biting into the gas diffusion layer 19 differs in each power generation cell, there is also a problem that the stability of the power generation voltage is lowered.

In order to solve the above-mentioned problems, a lath cut molding apparatus shown in FIG. 8 was employed. As shown in FIG. 8, this lath cut molding apparatus has a first shearing die 33 in which only the shearing blade 33 b is formed, and the recesses 34 b and the projections 34 a are alternately positioned above the first shearing die 33. A second shearing die 34 formed. When forming a lath cut metal using this lath cut, the following method has been adopted. That is, in one up / down operation of the second shearing die 34, the upper half ring portion and the lower half ring portion are alternately formed by the concave portion 34b and the convex portion 34a. In this case, when the lower half ring part formed by the convex part 34a is deformed downward, the upper half ring part formed by the concave part 34b hangs obliquely downward. This hanging portion forms a bent flat portion 29 shown in FIG. The bent flat portion 29 functions as the contact portion 29 of the gas flow path forming member 21 and is in surface contact with the gas diffusion layer 19. Thereby, the problem resulting from the biting of the contact portion 29 described above can be solved. However, in the case where the bent flat portion 29a is formed in this way, there is a problem that the effective area of the gas flow path is reduced and the power generation efficiency is lowered because the thickness T of the gas flow path forming member 21 is reduced. there were.

The present invention eliminates the problems in the above-described conventional technology, suppresses the gas flow path forming member from biting into the gas diffusion layer, and improves the power generation efficiency of the fuel cell, and can improve the power generation efficiency of the fuel cell. And a manufacturing method thereof.

In order to solve the above problems, according to a first aspect of the present invention, an electrode layer, a gas diffusion layer formed on a surface of the electrode layer, a separator facing the gas diffusion layer, and the gas A gas flow path forming member formed between the diffusion layer and the separator and having a gas flow path for supplying either the fuel gas or the oxidant gas to the electrode layer, and is generated in the electrode layer In a power generation cell of a fuel cell that generates power by electrode reaction, the gas flow path forming member is constituted by a lath cut metal formed of a thin metal plate, and the gas flow path forming member has a plurality of through holes of a predetermined shape. The ring part is formed in a mesh shape, and the ring part is formed with a bent flat part in surface contact with the surface of the gas diffusion layer, and between the bent flat part and the connecting plate part connecting the ring part. Is Bent flat portion is formed, the a bent flat portion and the non-bending plane portion is power generation cell of a fuel cell is formed by a plurality of steps one after the Rasukatto molding apparatus is provided.

Moreover, in the power generation cell of the fuel cell according to the present invention, each of the ring portions is preferably formed in a pentagonal shape or a hexagonal shape.
In the second embodiment of the present invention, the first shear die having a linear first shear blade, and a plurality of recesses and projections alternately formed at a predetermined interval are provided, and each of the projections is provided. And a second shearing die provided with a second shearing blade that forms a plurality of cuts in the metal thin plate in cooperation with the first shearing blade, along the feeding direction of the metal thin plate in the metal thin plate. A plurality of first processed parts and second processed parts that are alternately positioned are sequentially processed, and the first processed part of the metal thin plate is in an intermediate forming position with respect to the first shear mold and the second shear mold. In a state where the first processed portion is sent to the first processed portion, a first step of forming a half ring portion including the bent plane portion with respect to the first processed portion, and after the first step, the first processed portion is moved to the first processed portion. With the first shear mold and the second shear mold further fed to the final molding position, A second step of forming a half ring portion including the non-bent flat portion with respect to a work part; and after the second step, the first workpiece from the upstream side in the feeding direction of the metal thin plate in the metal thin plate. In a state where the second processed part adjacent to the part is sent to the intermediate forming position with respect to the first shear mold and the second shear mold, the second shear mold is orthogonal to the feeding direction of the metal thin plate. A third step of forming a half ring portion including the bent flat portion with respect to the second processed portion by offsetting in the direction; and after the third step, the second processed portion is moved to the first processed portion. A fourth step of forming a half ring portion including the non-bent flat portion with respect to the second processed portion in a state where the second die is further sent to the final forming position with respect to the shear die and the second shear die; The first and second steps and the third and fourth steps Each other repeatedly performed, the manufacturing method of the power generation cell of a fuel cell and a step of molding the lath cut metal by molding the ring portion in a mesh shape with respect to the metal sheet is provided.

In the method for manufacturing a power generation cell of a fuel cell according to the present invention, it is preferable that the second step and the fourth step are each performed a plurality of times.
(Function)
In this invention, since the bent flat portion is formed in the contact portion that comes into contact with the gas diffusion layer such as carbon paper in the outer peripheral edge of the ring portion that forms the through hole of the gas flow path forming member, the surface of the gas diffusion layer On the other hand, the bent flat portion is brought into surface contact. For this reason, the contact portion does not bite into the gas diffusion layer, the destruction of the gas diffusion layer is prevented, and the destroyed gas diffusion layer enters the gas passage of the gas flow path forming member and the effective area of the gas passage Will not decrease.

In addition, since the present invention is such that the bent flat portion and the non-bent flat portion are formed by twice the lath cut processing, a wide bent flat portion is formed in the entire width direction of the ring portion by a single lath cut processing. Compared to the above, the formation width of the bent flat portion can be reduced, and the thickness of the gas flow path forming member can be increased correspondingly, thereby increasing the effective area of the gas flow path and improving the power generation efficiency. it can.

According to the present invention, the contact portion of the gas flow path forming member can be prevented from biting into the gas diffusion layer made of carbon paper or the like, and the thickness of the gas flow path forming member can be increased. The effective area of the flow path can be increased and the power generation efficiency of the fuel cell can be improved.

The longitudinal cross-sectional view of the fuel cell stack by which the electric power generation cell of this invention was laminated | stacked. The exploded perspective view of a power generation cell. The expanded perspective view which shows a part of 1st gas flow path formation member used for an electric power generation cell. The front view which shows a part of 1st gas flow path formation member. Sectional drawing which shows a part of 1st gas flow path formation member. Sectional drawing which shows the lamination | stacking state of a gas diffusion layer, the 1st gas flow path formation member, and a 1st separator. Sectional drawing which shows the lath metal lath cut molding apparatus. The perspective view which shows a part of 1st shear type and 2nd shear type. (A) is a sectional side view which shows the manufacturing process of a gas flow path formation member, (b) is a front view which shows the manufacturing process. (A) is a sectional side view which shows the manufacturing process of a gas flow path formation member, (b) is a front view which shows the manufacturing process. (A) is a sectional side view which shows the manufacturing process of a gas flow path formation member, (b) is a front view which shows the manufacturing process. (A) is a sectional side view which shows the manufacturing process of a gas flow path formation member, (b) is a front view which shows the manufacturing process. (A) is a sectional side view which shows the manufacturing process of a gas flow path formation member, (b) is a front view which shows the manufacturing process. (A) is a sectional side view which shows the manufacturing process of a gas flow path formation member, (b) is a front view which shows the manufacturing process. (A) is a sectional side view which shows the manufacturing process of a gas flow path formation member, (b) is a front view which shows the manufacturing process. (A) is a sectional side view which shows the manufacturing process of a gas flow path formation member, (b) is a front view which shows the manufacturing process. Sectional drawing which shows the laminated structure of the gas diffusion layer of a conventional power generation cell, a gas flow path formation member, and a separator. Sectional drawing which shows the state by which the separator was pressed with respect to the gas diffusion layer. Sectional drawing which shows the laminated structure of the gas diffusion layer of a conventional power generation cell, a gas flow path formation member, and a separator.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the fuel cell stack 11 of the present embodiment is a solid polymer type and includes a large number of stacked power generation cells 12.

As shown in FIG. 1 and FIG. 2, the power generation cell 12 has a square frame shape, first and

second frames

13 and 14 made of synthetic rubber (or synthetic resin), and an MEA 15 (Membrane-) as an electrode structure. Electrode-Assembly: capsule-electrode assembly). The first frame 13 defines a fuel gas passage space S1 inside thereof, and the second frame 14 defines an oxidant gas passage space S2 inside thereof. The MEA 15 is disposed between the

frames

13 and 14.

The power generation cell 12 includes a metal first gas flow path forming member 21 housed in the fuel gas passage space S1, and a metal second gas flow path forming member 22 housed in the oxidant gas passage space S2. It has. Further, the power generation cell 12 includes a flat plate-like first separator 23 and a second separator 24 made of titanium or a titanium alloy. The first separator 23 is bonded to the upper surfaces of the first frame 13 and the first gas flow path forming member 21 in the drawing. The second separator 24 is bonded to the lower surface of the second frame 14 and the second gas flow path forming member 22 in the drawing. In FIG. 2, the configuration of the gas flow

path forming members

21 and 22 is shown in a simplified form as a flat plate.

In the two

opposite sides

131 and 132 of the first frame 13, elongated

hole gas passages

13a and 13b are formed, respectively.

Gas passages

14a and 14b are formed in two

sides

141 and 142 orthogonal to the

sides

131 and 132 in the second frame 14, respectively.

As shown in FIGS. 1 and 2, the MEA 15 includes an electrolyte membrane 16, an anode layer 17 and a cathode layer 18, and gas diffusion layers 19 and 20 made of, for example, carbon paper having conductivity. The anode layer 17 is formed of a catalyst laminated on the anode side surface of the electrolyte membrane 16, that is, the upper surface in the drawing, and the cathode layer 18 is a catalyst laminated on the cathode side surface of the electrolyte membrane 16, that is, the lower surface in the drawing. Is formed by. The gas diffusion layers 19 and 20 are bonded to the surfaces of the electrode layers 17 and 18, respectively.

In the first separator 23, gas inlets 231a and 232a are formed on two sides corresponding to the side 131 of the first frame 13 and the side 141 of the second frame 14, and

gas outlets

231b and 231b are formed on the other two sides. 232b is formed. In the second separator 24, gas inlets 241a and 242a are formed on two sides corresponding to the gas inlets 231a and 232a, and

gas outlets

241b and 242b are formed on the other two sides.

As shown in FIG. 3, the first and second gas flow

path forming members

21 and 22 have the same configuration and are formed of a lath cut metal 25 (hereinafter simply referred to as a lath metal) having a plate thickness of about 0.1 mm. ing. As shown in FIG. 4, the lath metal 25 is formed so that a large number of substantially hexagonal through holes 26 meander. The ring portions 27 forming these through-holes 26 are connected so as to be sequentially overlapped by a connecting plate portion 28 (the portion given the dots in FIG. 3).

3 and 4, the upper half ring portion R1 of the ring portion 27 is composed of a pair of first inclined plate portion 27a and first flat plate portion 27b. The pair of first inclined plate portions 27a are opposed to each other, and the first flat plate portion 27b is formed integrally with the inclined plate portion 27a so as to be bridged with the upper end portions of both inclined plate portions 27a. The lower half ring portion R2 of the ring portion 27 in the figure is composed of a pair of second inclined plate portions 27c and a second flat plate portion 27d. The pair of second inclined plate portions 27c face each other, and the second flat plate portion 27d is formed integrally with the inclined plate portion 27c so as to be bridged with the upper end portions of both inclined plate portions 27c.

As shown in FIG. 3, the connecting plate portion 28 is the same plate portion as the second flat plate portion 27 d of the ring portion 27. A first contact portion 29 that faces the second flat plate portion 27 d of the ring portion 27 is formed on the first flat plate portion 27 b of each ring portion 27. When the power generation cell 12 is assembled, the first contact portion 29 comes into contact with the surface of the gas diffusion layer 19. Specifically, a bent flat portion 29a is formed in the first contact portion 29, and the bent flat portion 29a is in surface contact with the gas diffusion layer 19 (20) as shown in FIGS. Yes. A second contact portion 30 is formed on the second flat plate portion 27 d of each ring portion 27 so as to face the first flat plate portion 27 b of the ring portion 27. When the power generation cell 12 is assembled, the second contact portion 30 comes into line contact with the inner surfaces of the first or

second separators

23 and 24.

Between the bent flat part 29a and the connecting plate part 28 (lower flat plate part 27d), the first flat plate part 27b is formed with a non-bending flat part 27f located on the same plane as the connecting plate part 28. . The first flat plate portion 27b is formed by the non-bent flat portion 27f and the bent flat portion 29a. As shown in FIG. 5, the bending angle α of the bending plane portion 29a with respect to the connecting plate portion 28 (non-bending plane portion 27f) can be set in a range of 60 to 70 °. In the present embodiment, the bending angle α is set to 65 °.

As shown in FIG. 1, the first and second gas flow

path forming members

21 and 22 are accommodated in the fuel gas passage space S1 and the oxidant gas passage space S2 of the first and

second frames

13 and 14, respectively. The surfaces of the gas diffusion layers 19 and 20 are in contact with the inner surfaces of the first and

second separators

23 and 24.

As indicated by an arrow G1 in FIG. 2, the fuel gas introduced into the fuel gas passage space S1 from the gas introduction port 232a of the first separator 23 by the first gas flow path forming member 21 is the gas outlet port 232b or The gas flows to the gas passage 14b of the two frames 14 and the gas outlet 242b of the second separator 24. As shown by an arrow G2 in FIG. 2, the oxidation introduced into the oxidant gas passage space S2 by the second gas passage forming member 22 from the gas introduction port 231a of the first separator 23 through the gas passage 13a of the first frame 13. The agent gas flows through the gas passage 13 b of the first frame 13 to the gas outlet 231 b or the gas outlet 241 b of the second separator 24.

In the present embodiment, the first and

second frames

13 and 14 are formed of synthetic rubber. Therefore, it is possible to improve the sealing performance against the gas at the contact portion between the first frame 13 and the electrolyte membrane 16 and the contact portion between the first frame 13 and the second frame 14. Here, when the fuel cell stack 11 is configured by laminating the power generation cells 12, the first and second gas flow

path forming members

21 and 22 are caused to move to the first and

second separators

23, 22 by the fastening load of the stack 11. 24 is assembled in a state of being slightly pressed to the MEA 15 side. Thereby, the surface contact state between the bent flat surface portion 29 a of the first contact portion 29 of the first gas flow path forming member 21 and the gas diffusion layer 19 is appropriately maintained. The second gas flow path forming member 22 has a configuration according to the gas flow path forming member 21.

In the fuel cell stack 11, the gas introduction port 232 a of the first separator 23 and the gas introduction port 242 a of the second separator 24 of the stacked power generation cells 12 are connected to the fuel gas passage space S 1 and the second frame of the first frame 13. All are connected via 14 gas passages 14a. A fuel gas (hydrogen gas) flow passage is formed by the gas introduction port 232a, the gas introduction port 242a, the passage space S1, and the gas passage 14a. The gas inlet 231a of the first separator 23 and the gas inlet 241a of the second separator 24 are all connected via the gas passage 13a of the first frame 13 and the oxidant gas passage space S2 of the second frame 14. Yes. The gas introduction port 231a, the gas introduction port 241a, the gas passage 13a, and the oxidant gas passage space S2 form an oxidant gas (air) flow passage. The fuel gas and the oxidant gas supplied to the fuel gas flow path and the oxidant gas flow path are fed into the fuel gas path space S1 and the oxidant gas path space S2 by the first and second gas flow

path forming members

21 and 22, respectively. Uniformly diffuse. For example, the fuel gas in the fuel gas passage space S1 becomes a turbulent flow by passing through a large number of through holes 26 formed in the first gas flow path forming member 21, and is uniformly diffused in the gas passage space S1. Become. The fuel gas is further appropriately diffused by passing through the gas diffusion layer 19 and is uniformly supplied to the anode layer 17. Then, by supplying the fuel gas and the oxidant gas, an electrode reaction occurs in the MEA 15 and power generation is performed. Desired electric power is output from the fuel cell stack 11 including the plurality of stacked power generation cells 12.

Next, a lath cut molding apparatus for molding the first and second gas flow

path forming members

21 and 22 will be described.
FIG. 7 is a cross-sectional view showing this lath cut molding apparatus. This lath cut forming apparatus includes a pair of feed rollers 31 that are provided one above the other for sequentially supplying the metal thin plates 25A. The forming apparatus further includes a forming mechanism 32 that cuts the thin metal plate 25A and plastically deforms the thin metal plate 25A by bending and extending the thin metal plate 25A corresponding to the cut. By this forming mechanism 32, a large number of hexagonal through holes 26 (ring portions 27) having a mesh shape are formed in the metal thin plate 25 </ b> A in a step shape, and the lath metal 25 is formed.

As shown in FIG. 8, the forming mechanism 32 includes a first shearing die 33 and a second shearing die 34. The first shearing die 33 is fixed to a support base (not shown), and the second shearing die 34 is parallel to the vertical direction and the width direction of the metal thin plate 25A, that is, the rotation axis of the feed roller 31 by an elevator mechanism and an offset mechanism (not shown). It can reciprocate in the direction (direction perpendicular to the paper surface of FIG. 7). The upper surface 33a of the first shearing die 33 functions as a surface that supports the thin metal plate 25A, and a linear first shearing blade is provided on an edge of the upper surface 33a that is located downstream in the feed direction H of the thin metal plate 25A. 33b is formed. A planar position regulating surface 33c is formed below the first shearing blade 33b.

A large number of convex portions 34 a are horizontally formed at a predetermined pitch D below the second shearing die 34. A horizontal molding surface 34c is formed at the lower end of the convex portion 34a of the second shear mold 34, and inclined molding surfaces 34d are formed on the left and right sides of the convex portion 34a. A horizontal molding surface 34e is formed between the inclined molding surfaces 34d of the two adjacent convex portions 34a. The inclined molding surface 34d and the horizontal molding surface 34e define a plurality of concave portions 34b, and these concave portions 34b are alternately formed with the convex portions 34a. An inverted trapezoidal second shearing blade 34f is formed on an edge portion of the forming surface 34c and the inclined forming surface 34d located on the upstream side in the feed direction H of the thin metal plate 25A. The second shearing blade 34f can cut the metal thin plate 25A in cooperation with the first shearing blade 33b.

Next, a method of the present embodiment for forming the gas flow

path forming members

21 and 22 using the forming apparatus configured as described above will be described with reference to FIGS.
In the method of the present embodiment, a plurality of first processed portions P1 and second processed portions P2 that are alternately positioned along the feeding direction H of the thin metal plate 25A in the thin metal plate 25A are sequentially processed. In the first step of this method, first, as shown in FIG. 9A, the first processed portion P1 of the metal thin plate 25A is moved by the feed roller 31 (see FIG. 7) into the first shear die 33 and the second shear. The mold 34 is sent to an intermediate molding position. In the present embodiment, the metal thin plate 25A is fed to a position where the end protrudes from the first shearing blade 33b in the feed direction H by a predetermined first feed amount L1 (for example, 0.2 mm). In this state, the second shearing die 34 descends toward the first shearing die 33, and a part of the first workpiece portion P1 is sheared by the first shearing blade 33b and the second shearing blade 34f, and a large number of them are sheared. A break is formed. Next, as shown in FIGS. 10A and 10B, the second shearing die 34 descends to the lowest point position and comes into contact with the convex portion 34a of the second shearing die 34 in the metal thin plate 25A. The part where it is bent and extended downward. A portion curved and extended by the convex portion 34a in the metal thin plate 25A has a substantially inverted trapezoidal shape as shown in FIG. On the other hand, a portion between the curved and extended portions enters the concave portion 34b and has a substantially trapezoidal shape.

In this first step, the second flat plate portion 27d (connecting plate portion 28) that forms the lower half ring portion R2 of the ring portion 27 is formed horizontally as shown in FIG. 10B. The surface 34c is pressed down and formed. Therefore, the second flat plate portion 27d is formed horizontally. On the other hand, the upper half ring portion R1 of the ring portion 27 formed corresponding to the concave portion 34b is not pressed upward by a forming portion having a horizontal forming surface, such as the convex portion 34a. For this reason, as shown in FIG. 10A, the first flat plate portion 27b of the half ring portion R1 formed by the concave portion 34b hangs down so as to incline downward about the first shearing blade 33b. As a result, a bent plane portion 29 a having a bending angle α with respect to the horizontal portion of the thin metal plate 25 A is formed, and this bent plane portion 29 a functions as the first contact portion 29. Thereafter, as shown in FIGS. 11A and 11B, the second shearing die 34 returns from the lowest point position to the upper original position.

Subsequently, in the second step of this method, as shown in FIG. 11A, the metal thin plate 25A is further moved in the feed direction H by the feed roller 31 (see FIG. 7) to a predetermined second feed amount L2 ( For example, 0.1 mm). Thus, the first processed portion P1 of the metal thin plate 25A is sent to the final processing position with respect to the first shearing die 33 and the second shearing die 34. In this state, as shown in FIGS. 12A and 12B, the second shearing die 34 is lowered again without being offset from the position in the first step in the width direction of the metal thin plate 25A. The upper half ring portion R1 and the lower half ring portion R2 of the ring portion 27 are formed on the edge of the thin metal plate 25A. At this time, the first flat plate portion 27 b of the upper half ring portion R <b> 1 is in a free state like the first contact portion 29. The second feed amount L2 is set smaller than the first feed amount L1 described above, and the entire first flat plate portion 27b is located in the vicinity of the first shearing blade 33b. Therefore, the first flat plate portion 27b can easily follow the horizontal molding surface 34e of the concave portion 34b of the second shear mold 34. As a result, as shown in FIG. 12A, the first flat plate portion 27b located on the rear side of the bent flat portion 29a hardly hangs down and is held in a substantially horizontal state. The first flat plate portion 27b becomes a non-bent flat portion 27f. By this second step, the half ring portions R1 and R2 including the non-bending flat surface portion 27f are finally formed.

As described above, in the present embodiment, the half ring portions R1 and R2 that are originally formed by a single molding operation are molded in two steps, and then the bent plane portion 29a formed at the first time is followed by a non-bend. The flat portion 27f is formed. Thereby, compared with the case where shaping | molding of half ring part R1, R2 is performed only by one shaping | molding operation | movement, the formation width | variety of the bending plane part 29a can be made small, and it can form in an appropriate width | variety.

Next, in the third step of this method, as shown in FIG. 13A, after the second shearing die 34 is lifted and moved to the original position, the metal sheet 25A is moved from the upstream side in the feed direction H to the first. The second processed part P2 adjacent to the first processed part P1 is sent to the intermediate forming position with respect to the first shear mold 33 and the second shear mold 34. In other words, the thin metal plate 25A is again fed in the feed direction H by the first feed amount L1. And as shown in FIG.13 (b), the 2nd shear type | mold 34 descend | falls after offset by the half (half pitch) of the arrangement pitch D of the ring part 27 along the width direction of the metal thin plate 25A, and 2nd The part P2 to be processed is formed as shown in FIGS. 14 (a) and 14 (b). Then, the half ring portion R1 is formed on the upper side of the half ring portion R2, and the half ring portion R2 is formed on the lower side of the half ring portion R1, thereby forming a plurality of ring portions 27.

Next, in the fourth step of this method, as shown in FIGS. 15 (a) and 15 (b), the metal sheet 25A is further moved to the second feed amount L2 while the second shearing die 34 remains offset. Only sent. Accordingly, the second processed portion P2 is sent to the final processing position with respect to the first shearing die 33 and the second shearing die 34. As shown in FIGS. 16A and 16B, the second shearing die 34 is lowered, and the half ring portions R1 and R2 including the non-bending flat surface portion 27f are finally formed.

Thereafter, by alternately repeating the first and second steps and the third and fourth steps described above, the parts P1 and P2 to be processed are alternately processed, and the lath metal 25 shown in FIGS. Is formed. In the lath metal 25, as shown in FIG. 3, a ring portion 27 having a large number of mesh-like through holes 26 is formed to meander.

The thin metal plate 25A that is not sheared by the second shearing blade 34f provided on the convex portion 34a of the second shearing die 34 remains as a portion where the cut is not processed in the lath metal 25. This unbroken portion is the connecting plate portion 28 (second flat plate portion 27d). Accordingly, the ring portions 27 are connected so as to overlap one another, and the cross-sectional shape of the lath metal 25 is formed in a stepped shape as shown in FIGS. 3 and 5.

Thus, after the manufacture of the lath metal 25 is completed, the lath metal 25 is cut into a predetermined dimension, and the first and second gas flow

path forming members

21 and 22 shown in FIGS. 1 and 2 are formed.

The first gas flow path forming member 21 manufactured as described above is incorporated into the power generation cell 12 as shown in FIG. In this state, as shown in FIG. 6, the bent flat portion 29 a of the first contact portion 29 of the first gas flow path forming member 21 is in surface contact with the upper surface of the gas diffusion layer 19, and the second contact portion 30 is Line contact is made with the back surface of the first separator 23.

According to the above embodiment, the following effects can be obtained.
(1) In the above embodiment, the first and second gas flow

path forming members

21 and 22 housed in the fuel gas passage space S1 and the oxidant gas passage space S2 of the first and

second frames

13 and 14 are the lath metal 25. It was molded by. A bent flat portion 29 a is formed in a portion of the ring portion 27 of the lath metal 25 that contacts the surfaces of the gas diffusion layers 19 and 20, that is, in the first contact portion 29. For this reason, the contact state between the gas diffusion layers 19 and 20 formed from the fibers and the first contact portion 29 can be in surface contact, and the first contact portion 29 bites into the surfaces of the gas diffusion layers 19 and 20. Can be suppressed. Therefore, the fuel gas passage space S1 and the oxidant are caused by the gas diffusion layers 19 and 20 entering the fuel gas passage and the oxidant gas passage of the first and second gas

passage forming members

21, 22. It can suppress that the effective cross-sectional area of gas passage space S2 falls. As a result, it is possible to suppress a decrease in power generation efficiency due to a decrease in the supply amount of the fuel gas and the oxidant gas. Further, as compared with the case where the first contact portion 29 is in line contact with the gas diffusion layers 19, 20, the electrical connection between the gas diffusion layers 19, 20 and the first and second gas flow

path forming members

21, 22 is achieved. The connection is made properly. Therefore, the flow of electricity from the gas diffusion layers 19 and 20 to the first and second gas flow

path forming members

21 and 22 becomes smooth, and the current collection efficiency can be improved. Furthermore, damage to the portion in contact with the first contact portion 29 in the portions of the gas diffusion layers 19 and 20 can be prevented. Therefore, for example, carbon fibers in the carbon paper forming the gas diffusion layers 19 and 20 can be prevented from being cut and clogged in the gas passages of the gas flow

path forming members

21 and 22, and power generation performance can be ensured. .

(2) In the above embodiment, the ring portion 27 that is originally performed in a single step by the first shear die 33 having only the first shear blade 33b and the second shear die 34 having the convex portion 34a and the concave portion 34b. The half ring portions R1 and R2 were formed in two steps. Thereby, as shown in FIG. 5, compared with the case where shaping | molding of half ring part R1, R2 is performed at one process, the formation width W1 of the bending plane part 29a is made small, and the gas flow path formation member 21 of FIG. The thickness T1 can be set large. Therefore, the effective area of the gas flow path in the gas flow path forming member 21 can be secured, the gas can be properly supplied, and the power generation efficiency can be improved.

(3) In the above embodiment, since the conventional apparatus having the simple structure shown in FIGS. 7 and 8 can be used as the lath cut forming apparatus, the molding apparatus can be simplified and the ring portion 27 can be simplified. In the first contact portion 29, the bent flat portion 29a can be easily formed.

In addition, you may change the said embodiment as follows.
A molding surface that faces the horizontal molding surface 34c of the convex portion 34a of the second shearing mold 34 may be provided on the side surface of the first shearing mold 33 that is located downstream in the feed direction H of the thin metal plate 25A. In this case, when the second shearing die 34 is lowered, the forming surface formed on the first shearing die 33 and the horizontal forming surface 34c of the convex portion 34a sandwich the metal thin plate 25A, thereby the ring portion 27. It is possible to prevent the second flat plate portion 27d from being bent.

The second step shown in FIGS. 11 and 12 and the fourth step shown in FIGS. 15 and 16 may be performed in a plurality of times.
In the above embodiment, the second shearing die 34 is offset in the width direction of the metal thin plate 25A by half the pitch D of the convex portions and the

concave portions

34a and 34b of the second shearing die 34, that is, the half pitch, and the half ring portion R1 , R2 is formed. You may change this offset amount suitably. Further, the ring portion 27 may not be arranged to meander.

-You may shape the shape of the ring part 27 in shapes other than hexagonal shape, such as a pentagonal shape.
-As a material of the 1st, 2nd gas flow

path formation members

21 and 22, the metal which has electroconductivity, such as a stainless plate, aluminum, copper, can be adopted, for example.

Claims

An electrode layer;
A gas diffusion layer formed on the surface of the electrode layer;
A separator facing the gas diffusion layer;
A gas flow path forming member formed between the gas diffusion layer and the separator and formed with a gas flow path for supplying any one of a fuel gas and an oxidant gas to the electrode layer;
In a power generation cell of a fuel cell that generates power by an electrode reaction occurring in the electrode layer,
The gas flow path forming member is constituted by a lath cut metal formed of a thin metal plate, and the gas flow path forming member has a plurality of ring portions having through holes of a predetermined shape formed in a mesh shape,
The ring part is formed with a bent plane part in surface contact with the surface of the gas diffusion layer, and a non-bent plane part is formed between the bent plane part and the connecting plate part connecting the ring part. ,
The bent flat portion and the non-bent flat portion are formed in a plurality of steps before and after the lath cut forming apparatus.
The power generation cell of the fuel cell according to claim 1,
Each said ring part is shape | molded in the pentagon shape or the hexagon shape. The power generation cell of the fuel cell characterized by the above-mentioned.
In the manufacturing method of the power generation cell of the fuel cell according to claim 1 or 2,
A first shear type having a linear first shear blade;
A second shear comprising a plurality of recesses and projections alternately formed at a predetermined interval, and forming a plurality of cuts in the metal thin plate in cooperation with the first shearing blade at each projection; Using a second shearing die provided with a blade, sequentially processing a plurality of first processed parts and second processed parts located alternately along the feeding direction of the thin metal sheet in the thin metal sheet,
A half ring including the bent plane portion with respect to the first processed portion in a state where the first processed portion of the metal thin plate is sent to the intermediate forming position with respect to the first and second shearing dies. A first step of forming the part;
After the first step, in the state where the first processed portion is further sent to the final forming position with respect to the first and second shearing molds, A second step of forming a half ring part including a bent plane part;
After the second step, the second processed part adjacent to the first processed part from the upstream side in the feeding direction of the thin metal sheet is moved with respect to the first shear mold and the second shear mold after the second step. The second ring is offset in the direction perpendicular to the feeding direction of the thin metal plate in a state where the second shearing die is fed to the intermediate forming position, and the half ring part including the bent plane part with respect to the second processed part. A third step of molding
After the third step, the second processed part is further sent to the final forming position with respect to the first shearing mold and the second shearing mold, and the second processed part is moved to the second processed part. A fourth step of forming a half ring part including a non-bent flat part;
The steps of alternately performing the first and second steps and the third and fourth steps, forming the ring portion into a mesh shape with respect to the metal thin plate, and forming the lath cut metal, A method for producing a power generation cell of a fuel cell, comprising:
In the manufacturing method of the power generation cell of the fuel cell according to claim 3,
Each of the second step and the fourth step is performed a plurality of times. A method for manufacturing a power generation cell of a fuel cell.