JP5565352B2 - FUEL CELL AND EXPANDED METAL MANUFACTURING DEVICE AND MANUFACTURING METHOD FOR FUEL CELL - Google Patents

Description

  The present invention relates to a technique for manufacturing an expanded metal that forms a mesh-like flow path along a membrane surface of an electrolyte membrane in a fuel cell.

  In general, a fuel cell includes a power generator layer including a membrane electrode assembly in which electrodes are joined to respective membrane surfaces of an electrolyte membrane, and a separator disposed with the power generator layer interposed therebetween, and the power generator layer and the separator A gas flow path is defined between the two. In recent years, it has been proposed that the gas flow path be formed in a mesh shape with expanded metal that has been subjected to press molding of a thin metal plate (Patent Document 1).

JP 2010-170984 A

  Expanded metal is capable of forming a mesh-like flow path (gas flow path) with a simple existing technique called press molding, and thus is advantageous in terms of cost, but further improvement in power generation performance is required.

  In general, the reaction gas is supplied from one end side of the fuel cell, passes through a mesh-like gas flow path formed by the expanded metal, and reaches each part of the electrode surface during the passage of the flow path. Is consumed. And off-gas is discharged | emitted from the other edge part of a fuel cell. For this reason, since the amount of gas (gas passage amount) is larger on the reaction gas supply side than on the off-gas discharge side, moisture is carried away by the gas passing through the expanded metal gas flow path. It is expected that the electrolyte membrane will continue to dry.

  On the other hand, since the temperature of a fuel cell increases with an electrochemical reaction, the temperature increase is suppressed by supplying a cooling refrigerant. Since the refrigerant takes the temperature of the fuel cell and warms, the refrigerant temperature is higher on the outflow side on the inflow side and outflow side of the refrigerant. For this reason, in the region which is both the refrigerant outflow side and the above-described reaction gas supply side, the refrigerant temperature is high, and accordingly, the effect of suppressing the temperature rise of the battery temperature is reduced, and moisture removal by the gas increases. Therefore, there is a concern that the electrolyte membrane may be further dried during high temperature operation of the fuel cell. Since drying of the electrolyte membrane can hinder the progress of the electrochemical reaction of the reaction gas, it is desirable to suppress drying. However, the conventional expanded metal lacks consideration for these points, and thus it has been desired to deal with drying of the electrolyte membrane.

  In view of the above-described problems, an object of the present invention is to provide a new expanded metal capable of suppressing drying of an electrolyte membrane and to improve power generation performance.

In order to achieve at least a part of the above object, the present invention adopts the following configuration.
A fuel cell,
A power generator layer including a membrane electrode assembly in which an electrode is bonded to each membrane surface of the electrolyte membrane;
A pair of separators that are arranged with the power generation layer sandwiched therebetween and that are involved in the supply and discharge of the reaction gas used in the power generation reaction in the power generation layer;
A flow that is disposed between the power generation layer and at least one of the pair of separators and forms a mesh-like flow path that allows the reaction gas from the separator to flow in the gas flow direction along the membrane surface of the electrolyte membrane. A road forming member,
The flow path forming member is:
The portion surrounding the mesh-shaped flow path has a wide and narrow difference in the contact part area that contacts the power generation body layer, and based on the flow rate of the reaction gas passing through the flow path, the electrolyte membrane of the power generation layer The mesh-like flow path having a wide contact area is formed in a range where drying is expected to occur more easily than other electrolyte membrane locations.

[Application 1: Fuel cell]
A fuel cell,
A power generator layer including a membrane electrode assembly in which an electrode is bonded to each membrane surface of the electrolyte membrane;
A pair of separators that are arranged with the power generation layer sandwiched therebetween and that are involved in the supply and discharge of the reaction gas used in the power generation reaction in the power generation layer;
A flow that is disposed between the power generation layer and at least one of the pair of separators and forms a mesh-like flow path that allows the reaction gas from the separator to flow in the gas flow direction along the membrane surface of the electrolyte membrane. A road forming member,
The flow path forming member is:
The area surrounding the mesh-shaped flow path has a wide and narrow difference in the contact part area in contact with the power generator layer, and in the range where the drying of the electrolyte membrane in the power generator layer is more likely to occur than other electrolyte membrane locations, The gist of the present invention is to form the mesh-like flow path having a wide contact area.

  In the fuel cell having the above-described structure, when forming a mesh-like channel along the membrane surface of the electrolyte membrane of the reaction gas from the separator by the channel-forming member, a portion surrounding the mesh-like channel is a power generator. There were wide and narrow differences in the area of the contact area in contact with the layer. If the contact part area is large, the area where the power generator layer surface layer is covered at the part surrounding the mesh-like flow path becomes larger, so that the reaction gas is generated when the reaction gas passes through the mesh-like flow path. The area in contact with the water becomes narrow, and moisture removal can be suppressed. The fuel cell having the above configuration forms a network-like flow path having a wide contact area in a range where the electrolyte membrane in the power generation layer is more likely to dry than other electrolyte membrane locations, so that the electrolyte membrane is dried. By suppressing the removal of moisture within an easy range, it is possible to suppress the drying of the electrolyte membrane. As a result, according to the fuel cell having the above configuration, the power generation performance can be improved by suppressing the drying of the electrolyte membrane.

  The fuel cell system described above can be configured as follows. For example, the flow path forming member can be an expanded metal, and in this way, the flow path forming member can be simply provided.

  Further, the separator is provided with a cooling medium flow path for cooling the power generation body layer, and the flow path of the gas flows in the mesh-shaped flow path formed by the flow path forming member. Crossed the direction. With respect to the flow path forming member, the region on the flow path end side in the flow path of the refrigerant and the upstream side of the flow path of the reactive gas in the mesh flow path is set as a range in which the electrolyte membrane is liable to dry. Thus, the mesh-like flow path having a wide area of the contact part can be formed in the region. In this way, in the region that is also the refrigerant channel end side where the refrigerant temperature rises due to the high-temperature operation of the fuel cell and also the upstream side of the reaction gas channel that is assumed to dry the electrolyte membrane due to moisture removal, the electrolyte described above The drying of the film can be suppressed. Therefore, the power generation capacity during high-temperature operation can be maintained or increased. In addition, as described above, since the area where the power generator layer surface layer is covered is widened at the portion surrounding the mesh-like flow path as described above, the consumption of the reaction gas is suppressed accordingly. . For this reason, since the unreacted reaction gas can easily reach the downstream side of the reaction gas flow path, the electrochemical reaction is activated and the power generation capability is increased. The power generation capacity of the entire battery will also increase.

[Application 2: Expanded metal manufacturing equipment for fuel cells]
An apparatus for producing expanded metal for fuel cells,
A supply section for feeding out metal plate materials;
By pressing a metal mold having convex blade parts arranged in the mold width direction against the metal plate material fed by the supply unit, recesses and projections are alternately continuous in the plate width of the plate material. A press portion for press-forming the mesh-shaped flow path,
The mold is
The width of the mold is wider than the flow path width of the mesh-shaped flow path, and the width of the mold corresponds to the flow width of the first flow path of the mesh-shaped flow path and the remaining range of the mold. Dividing into the second mold width part, the pitch of the convex blade part in the first mold width part is narrower than the pitch of the convex blade part in the second mold width part, A convex blade portion is provided side by side with the first and second metal width portions,
The press section is
Holding the mold slidably along the mold width direction,
Press formation of the mesh-like flow path over the flow path width by the convex blade parts arranged in the first mold width, and the convex blades arranged in the second mold width part Press forming the mesh-shaped flow path across the flow path width by the convex blade portion in the first mold width continuous with the second mold width section. The gist is to switch by sliding along the mold width direction.

[Application 3: Manufacturing method of expanded metal for fuel cell]
A method for producing expanded metal for a fuel cell, comprising:
A delivery process for delivering a metal plate;
By pressing a mold having convex blade portions arranged in the mold width direction against the metal plate material to be sent out, a mesh-like structure in which concave portions and convex portions are alternately continuous in the flow path width. A press process for press forming the flow path,
In the pressing process,
A mold width wider than the flow path width is divided into a first mold width section corresponding to the flow path width of the mesh-shaped flow path and a remaining second mold width section, and the first mold width section The mold having the convex blade portion is arranged so that the pitch of the convex blade portion is narrower than the pitch of the convex blade portion in the second mold width portion. Slidable along the direction,
Press formation of the mesh-like flow path over the flow path width by the convex blade parts arranged in the first mold width, and the convex blades arranged in the second mold width part Press forming the mesh-shaped flow path across the flow path width by the convex blade portion in the first mold width continuous with the second mold width section. The gist is to switch by sliding along the mold width direction.

  According to the expanded metal manufacturing apparatus and manufacturing method for a fuel cell having the above-described configuration / procedure, the expanded metal that can contribute to the improvement of power generation performance through the suppression of drying of the electrolyte membrane is pressed into a metal plate. It can be easily manufactured with the existing method. In addition, since it is not necessary to replace the metal mold having the blade portion, the number of man-hours can be reduced, and the cost can be reduced.

  Furthermore, the present invention can be realized in various forms, for example, in the form of a fuel cell manufacturing method in which a network-like gas flow path is formed of the above-described expanded metal.

2 is an explanatory diagram showing a schematic configuration of a fuel cell stack 100 of the present embodiment together with a schematic configuration of a fuel cell 20. FIG. 3 is an explanatory diagram showing a schematic structure of a gas flow path forming member 40. FIG. FIG. 4 is an explanatory diagram showing the flow direction of air in the forming member in association with the cooling water flow direction in the separator 80 in contact with the gas flow path forming member 40 while viewing the gas flow path forming member 40 in plan view. It is explanatory drawing which shows typically the relationship between the electric power generation body layer 35, the gas flow path formation member 40, and the separator 80 along line 4-4 in FIG. FIG. 5 is an explanatory diagram schematically showing a relationship among a power generation layer 35, a gas flow path forming member 40, and a separator 80 along line 5-5 in FIG. It is explanatory drawing which shows the structure of the blade type | mold part 300 used for press formation of the gas flow path formation member 40, the structure of a supply system 340, and both. It is explanatory drawing which shows the switching of a press form, the relationship between a blade type | mold slide, and the base material 210 in planar view roughly. It is explanatory drawing which shows the 1st step of press formation in a 40W press form. It is explanatory drawing the 2nd step of press formation in a 40W press form. It is explanatory drawing which shows the 3rd step of press formation in a 40W press form. It is explanatory drawing which shows the 1st step of the press formation in a 40N press form. It is explanatory drawing the 2nd step of press formation in a 40N press form. It is explanatory drawing which shows the 3rd step of press formation in a 40N press form. 4 is an explanatory diagram schematically showing the relationship between the power generation distribution of the electrolyte membrane 31 in the power generation body layer 35 of the fuel cell 20 and the flow paths of air and gas in normal temperature operation and high temperature operation. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing a schematic configuration of a fuel cell stack 100 of this embodiment together with a schematic configuration of a fuel cell 20. As shown in the figure, the fuel cell stack 100 includes a plurality of polymer electrolyte fuel cells 20 stacked, terminals and insulators (not shown) arranged at both ends, and sandwiched between end plates 95 and 96. Composed. In this fuel cell stack 100, hydrogen gas as fuel gas and air as oxidant gas are supplied to the fuel cell 20 from the hydrogen supply manifold 95a and air supply manifold 95b, and the exhaust gas is supplied from the hydrogen discharge manifold 95c and air discharge manifold 95d. Discharged. Further, the cooling water is supplied from the cooling water supply manifold 95e to the fuel cell 20, and the waste water is discharged from the cooling water discharge manifold 95f.

  The fuel cell 20 is configured by laminating gas flow path forming members 40, 60 and separators 70, 80 on both surfaces of the power generation body layer 35. The power generation body layer 35 is configured by bonding gas diffusion layers 33a and 33b to both surfaces of an MEA (Membrane Electrode Assembly) 34 as an electrolyte membrane / electrode assembly. The MEA 34 includes a cathode electrode 32 a and an anode electrode 32 b on the surface of the electrolyte membrane 31. The electrolyte membrane 31 is a thin film of a solid polymer material that exhibits good proton conductivity in a wet state. In this embodiment, Nafion (registered trademark) is used for the electrolyte membrane 31. The cathode electrode 32a and the anode electrode 32b are electrodes in which a catalyst is supported on a carrier having conductivity. In this embodiment, carbon particles supporting a platinum catalyst, a polymer electrolyte constituting the electrolyte membrane 31, and With the same electrolyte.

  The gas diffusion layers 33a and 33b can be formed of a conductive member having gas permeability, such as carbon paper or carbon cloth, a metal mesh, or a foam metal. In this embodiment, carbon paper is used for the gas diffusion layers 33a and 33b. The gas diffusion layers 33a and 33b diffuse the oxidizing gas or the fuel gas and supply it to the entire surface of the cathode electrode 32a or the anode electrode 32b. The gas diffusion layers 33a and 33b have a smaller porosity than those of gas flow path forming members 40 and 60, which will be described later. In addition to the gas diffusion function, the gas diffusion layers 33a and 33b also have a current collecting function and a MEA 34 protection function. . The gas diffusion layers 33a and 33b may have a function of adjusting the moisture content of the MEA 34.

  The power generator layer 35 is integrally formed with a seal gasket 36 disposed on the outer periphery thereof. The seal gasket 36 includes a hydrogen supply manifold 30a, an air supply manifold 30b, a hydrogen discharge manifold 30c, an air discharge manifold 30d, a cooling water supply manifold 30e, and a cooling water discharge manifold 30f. The seal gasket 36 is formed with convex portions surrounding each manifold and the outer peripheral portion of the power generation layer 35 in the thickness direction, and the portions are separators laminated on both sides of the seal gasket 36. 70 and 80, and functions as a seal that suppresses leakage of fluid (fuel gas, oxidizing gas, cooling water) from the inside of the manifold and the power generation layer 35.

  The gas flow path forming members 40 and 60 form a gas flow path for supplying gas to the power generation body layer 35. The gas flow path forming member 40 is disposed between the anode electrode 32b side of the power generation body layer 35 and the separator 70 (flow path forming region), and is a fuel gas (here, hydrogen gas) supplied via the separator 70. The fuel gas is supplied to the anode electrode 32b side of the power generation body layer 35 while flowing in a flow from one side of the electrode surface of the MEA 34 toward the other side. Similarly, the gas flow path forming member 60 supplies an oxidizing gas (air in this case) to the cathode electrode 32 a side of the power generation body layer 35. The gas flow path forming members 40, 60 are formed of a metal having corrosion resistance and conductivity, such as stainless steel, titanium, titanium alloy, etc., but in this embodiment, stainless steel was used. The detailed structure of the gas flow path forming members 40 and 60 will be described later. In the present embodiment, the gas flow path forming members 40 and 60 are provided on both surfaces of the power generation body layer 35, but may be provided only on one side of the power generation body layer 35.

  Separator 70,80 is a member which functions as a reaction gas partition, and has the same configuration. Hereinafter, the separator 70 will be described. The separator 70 is formed of a gas impermeable conductive member, such as a member made of compressed carbon or stainless steel. In this example, stainless steel was used. In the separator 70, a flat cathode side separator 71 provided on the cathode electrode 32a side, a flat anode side separator 73 provided on the anode electrode 32b side, and an intermediate separator 72 disposed therebetween are integrated. Composed. The cathode-side separator 71 includes a hydrogen supply manifold 71a, an air supply manifold 71b, a hydrogen discharge manifold 71c, an air discharge manifold 71d, a cooling water supply manifold 71e, a cooling water discharge manifold 71f, and air communication holes 75 and 76. The air supplied to the air supply manifold 71 b flows through the air communication hole 72 b and the air communication hole 75 of the intermediate separator 72 and flows in the other fuel cell 20 (not shown) provided facing the cathode side separator 71. Guided to the path forming member 40. The exhaust gas is discharged to the air discharge manifold 71d through the air communication hole 76 and the communication hole (not shown) of the intermediate separator 72.

  Similarly, the hydrogen supplied to the hydrogen supply manifold 71a is guided to the gas flow path forming member 60 through the hydrogen communication hole 72a of the intermediate separator 72 and the communication hole (not shown) of the anode side separator 73, and the gas flow After flowing through the passage forming member 60, it is discharged to the hydrogen discharge manifold 71 c through the communication holes (not shown) of the intermediate separator 72 and the anode side separator 73. The intermediate separator 72 is formed with a plurality of cutouts along the long side direction of a substantially rectangular outline, and both ends of the cutouts communicate with the cooling water discharge manifold 71f and the cooling water supply manifold 71e, respectively. The separator 70 is not limited to the three-layer structure described above. For example, the cathode side separator 71 and the anode side separator 73 may have a two-layer structure, and a shape corresponding to the communication hole formed in the intermediate separator 72 may be formed inside the cathode side separator 71 and / or the anode side separator 73. Good.

  The separator 70 forms a cooling water flow path in the intermediate separator 72 sandwiched between the cathode separator 71 and the intermediate separator 72 when discharging the cooling water flowing in from the cooling water supply manifold 71e from the cooling water discharge manifold 71f. . The same applies to the separator 80, and the separator 80 located on the cathode electrode 32a side of the power generation body layer 35 is formed with a cooling water flow path as indicated by a dotted line in FIG. Then, the power generator layer 35 is cooled. In this case, the cooling water flow path of the separator 80 and the air flow path in the gas flow path forming member 40 are formed so that the flow direction of the cooling water and the flow direction of the air intersect.

  Next, the gas flow path forming members 40 and 60 will be described. In this embodiment, since the gas flow path forming member 40 and the gas flow path forming member 60 have the same structure, the following description will be made as the structure of the gas flow path forming member 40 on the cathode electrode 32a side. To do. FIG. 2 is an explanatory view showing a schematic structure of the gas flow path forming member 40, and FIG. 3 is a separator that contacts the gas flow path forming member 40 in the air flow direction in the forming member while viewing the gas flow path forming member 40 in plan view. It is explanatory drawing shown in relation with the cooling water flow direction in 80. FIG.

  As shown in FIG. 2, the gas flow path forming member 40 has the concave portions 51 and the convex portions 53 alternately and continuously in one direction (hereinafter, this direction is referred to as the X direction for convenience), Expand metal that repeats in the Y direction orthogonal to The gas flow path forming member 40 includes a concave portion 51 and a convex portion 53 arranged in the Y direction, and the bottom portion of the concave portion 51 and the top portion 53a of the convex portion 53 arranged in the Y direction are connected. 53, a through hole 41 along the Y direction is formed, and a continuous flow path 41 forms a mesh-like flow path. Hereinafter, in this embodiment, the Y direction in the figure is the flow path direction, the front side of the figure is the air in side, the back side is the out side, and the mesh-like flow path formed by the concave portions 51 and the convex portions 53 is: The formation wall of the recessed part 51 and the convex part 53 is comprised as a shape connected with a fixed gradient with respect to XY plane. The flow direction of the air in the Y direction shown in FIG. 2 is the direction indicated by the solid line in the gas flow path forming member 40 of FIG.

  The gas flow path forming member 40 has the concave portion 51 and the convex portion 53 as one cycle and is continuous in the same cycle, and the phase of the concave and convex portions is shifted by almost a half cycle (half pitch) in the Y direction. Further, in the gas flow path forming member 40, a convex portion continuous with the concave portion 51 is a wide range convex portion 54 in the region on the lower right side in FIG. 2. The formation area of the wide area convex portion 54 (hereinafter, wide area convex area 40W) is shown by a cross hatch in FIG. 3, and the gas flow path forming member 40 sandwiched between the power generation layer 35 and the separator 80 (see FIG. 1). ), The end side of the cooling water flow path in the separator 80 (specifically, the end side 1/4 to 1/2 of the cooling water flow path), and the air formed in the through hole 41 in the gas flow path forming member 40 It is an area on the upstream side of the flow path (specifically, on the upstream side 1/4 to 1/2 of the air flow path). The range of the normal hatch in FIG. 3 is a region (hereinafter referred to as a normal region 40N) in which the air flow paths are formed in a mesh pattern by alternately and continuously forming the concave portions 51 and the convex portions 53. In the example of FIG. 2, the concavo-convex in the X direction is described by repeating six pairs in the Y direction. However, this is for the convenience of illustration, and actually, in accordance with the specifications of the power generation layer 35, the concavo-convex The continuation is repeated in the X and Y directions.

  Since the gas flow path forming member 40 has the wide-area convex portion 54 connected to the concave portion 51 in the wide-area convex portion area 40W described above, in the wide-area convex portion area 40W, the bottom of the concave portion 51 is aligned with the Y direction. The through hole 41 is formed by the concave portion 51 and the wide area convex portion 54 by connecting the top portion 54 a of the wide area convex portion 54. Thus, there is a difference in size between the through hole 41 formed by the concave portion 51 and the wide convex portion 54 and the through hole 41 in the normal region 40N where the concave portion 51 and the convex portion 53 are continuous. As shown in FIG. 2, the gas flow path forming member 40 brings the top surface sides of the convex portion 53 and the wide range convex portion 54 into contact with the MEA 34, specifically, the power generator layer 35 (see FIG. 1). The apex portion 54a of the wide-area convex portion 54 surrounding the through-hole 41 of the wide-area convex portion area 40W where the concave portion 51 and the wide-area convex portion 54 are continuous on the power generator layer 35 side is a normal portion where the concave portion 51 and the convex portion 53 are continuous. It becomes wider than the top 53a of the convex part 53 which surrounds the through-hole 41 of the area | region 40N by the electric power generation body layer 35 side. Therefore, the gas flow path forming member 40 has a wide and narrow difference in the top area where the top of the convex portion 53 or the wide range convex portion 54 surrounding the through-hole 41 contacts the power generator layer 35. This will be described with reference to the drawings. 4 is an explanatory view schematically showing the relationship among the power generating layer 35, the gas flow path forming member 40, and the separator 80 along line 4-4 in FIG. 3, and FIG. 5 is along line 5-5 in FIG. FIG. 6 is an explanatory diagram schematically showing a relationship among a power generation layer 35, a gas flow path forming member 40, and a separator 80. In this case, in the figure, a series of concave portions 51 and convex portions 53 and concave portions 51 and wide range convex portions 54 in the X direction in FIG. 2 are shown, but these are hung from the near side to the far side of the drawing. As a result, the through holes 41 overlap with each other by being shifted by a half cycle of the concave portion 51 and the convex portion 53.

  As shown in FIGS. 4 to 5, in the wide-area convex portion area 40 </ b> W, the top portion 54 a of the wide-area convex portion 54 is widened by the wide pitch of the concave portions 51 in the area, and is in contact with the power generation body layer 35. The top area increases. On the other hand, in the normal region 40N, the top portion 53a of the convex portion 53 is narrowed by the narrow pitch of the concave portions 51 in the region, and the top area in contact with the power generation body layer 35 is also narrowed. In this case, the top 53a of the convex part 53 and the top part 54a of the wide-range convex part 54 are inclined and come into contact with the power generator layer 35, but the gas (air; FIG. 1), the top 53a and the top 54a are diffused into the power generation layer 35 (permeation) because they are inclined so as to be guided from the power generation layer 35 side to the separator 80 side. ) To cover the surface layer of the power generator layer 35. Note that the bottom of the recess 51, the top 53a of the protrusion 53, and the top 54a of the wide-range protrusion 54 can be flattened so as to be parallel to the XY plane in FIG. The area of the top portion described above is in surface contact with 35, that is, the area covering the surface layer of the power generation layer 35 becomes more prominent.

  Next, a method for manufacturing the gas flow path forming members 40 and 60 will be described. FIG. 6 is an explanatory diagram showing the configuration of the blade mold part 300 and the supply system 340 used for press forming of the gas flow path forming member 40 and the relationship between them. As shown in the figure, the supply system 340 feeds the substrate 210 to the blade mold part 300 by a roller pair 342 in which rollers are opposed to each other. The base material 210 is a stainless steel plate and receives the press described later by the blade mold part 300 to become an expanded metal gas flow path forming member 40 shown in FIG. Hereinafter, for convenience of explanation, the width of the base material 210 is the same as the width of the gas flow path forming member 40, but the base material 210 may be equal to the width of the gas flow path forming member 40. In addition, the blade mold portion 300 described below may be wide.

  The blade mold part 300 is a press mold and includes an upper blade mold 310, a lower blade mold 320, and a lower receiving blade mold 330. The blade mold part 300 having these blade parts has an air flow path width of the gas flow path forming member 40 shown in FIG. 3, that is, a mold width wider than the width of the gas flow path forming member 40 itself. The substrate 210 to be fed is pressed by the blade part to form a mesh-like gas flow path in which the above-described through holes 41 (see FIGS. 2 to 5) are continuous. The upper blade mold 310 has convex convex blade portions 312 arranged in the mold width direction (X direction). The lower blade mold 320 has an edge extending along the mold width direction (X direction), and participates in cutting the base material with the projecting blade portion 312 that descends. The lower receiving blade mold 330 has concave blade portions 332 corresponding to the convex blade portions 312 of the upper blade die 310 arranged in the mold width direction (X direction), and the convex blade portions 312 enter the concave blade portions 332. Thus, the recess 51 shown in FIG. 2 is formed. The blade mold part 300 includes a lower blade mold 320 in a positional relationship fixed with respect to the base 210 delivered by the supply system 340, and slides the upper blade mold 310 and the lower receiving blade mold 330 along the mold width direction. Hold as possible. Therefore, the upper blade mold 310 and the lower receiving blade mold 330 slide in the substrate width direction, that is, the mold width direction with respect to the substrate 210 sent out by the supply system 340.

  The upper blade mold 310 and the lower blade mold 320 are flow paths in which the normal region 40N and the wide-area convex region 40W are continuous in the flow channel width direction as shown in FIG. The 40W press form that forms the press and the 40N press form that forms the press of the flow path having the normal area 40N in the entire flow path width are adopted. The upper blade mold 310 is provided with the convex blade portions 312 at an equal pitch in the first mold width portion which is the key to press formation in the 40N press form, and the convex blade portion 312 in the remaining second mold width portion. With a wide pitch. The formation pitch of the convex blade portions 312 in the first mold width portion, which is the key to the press formation in the 40N press form, is made equal to the pitch (first pitch) of the concave portions 51 aligned with the convex portions 53 shown in FIG. Yes. Further, the pitch (second pitch) of the convex blade portions 312 in the remaining second mold width portion is equal to the pitch of the concave portions 51 arranged in the wide range convex portion 54 shown in FIG. It is narrower than the second pitch. The lower receiving blade mold 330 includes a concave blade portion 332 in combination with the convex blade portions 312 of the upper blade mold 310 described above. In the 40 W press form shown in FIG. 6, the blade mold portion 300 presses the concave portions 51 arranged at the wide second pitch and the concave portions 51 arranged at the narrow first pitch against the base material 210. On the other hand, in the 40N press form shown in FIG. 6, only the concave portions 51 arranged at a narrow first pitch are pressed against the base material 210. As described above, when the base material 210 has the same width as the width of the gas flow path forming member 40, the blade mold portion 300, specifically, the upper blade mold 310, has the above-described first pitch and second pitch. The concave portions 51 arranged at a pitch are repeatedly provided in the mold width direction. The same applies to the lower receiving blade mold 330. In FIG. 6, for convenience of illustration, in the 40 W press form, the three concave portions 51 are arranged at the first pitch and the three concave portions 51 are arranged at the second pitch. In the 40 N press form, the first concave portion 51 is arranged. The six concave portions 51 are arranged at a pitch. The same applies to FIG. 8 and later described later.

  Next, the press molding procedure by the blade mold part 300 will be described. FIG. 7 is an explanatory diagram schematically showing the relationship between the press mode switching, the blade-type slide, and the substrate 210 in plan view. As shown in the drawing, the base material 210 is sent out downward in the drawing, and the upper blade mold 310 and the lower receiving blade mold 330 of the blade mold part 300 are in a 40W press form and a 40N press form with respect to the base material 210. In each press form, a half-pitch slide is performed in the mold width direction, which is the left-right direction in the drawing, by half of the pitch of the recesses 51 in the normal region 40N. When the press form is switched between the 40W press form and the 40N press form, the upper blade mold 310 and the lower receiving blade mold 330 are formed over a wide range as shown in FIG. Slide in the width direction. FIG. 8 is an explanatory diagram showing a first stage of press formation in a 40 W press form, FIG. 9 is an explanatory view of a second stage of press formation in a 40 W press form, and FIG. 10 is a third stage of press formation in a 40 W press form. It is explanatory drawing which shows a step.

  In the 40 W press form of FIG. 6, as shown in FIG. 8A, the supply system 340 sends the base material 210 in the Y direction by the roller pair 342. The feed amount of the base material 210 is a length corresponding to the blade thickness of the upper blade mold 310, and the supply system 340 performs the base material feed each time a press described later by the blade mold portion 300. The blade mold part 300 presses the upper blade mold 310 up and down in the Z-axis direction as shown in FIG. By this pressing, the base 210 is partially sheared by the convex blade portion 312 of the lower blade die 320 and the upper blade die 310 and the concave blade portion 332 of the lower blade die 330, and therefore the convex portion 53 and the concave portion 51. And form. As a result, the concave portions 51 are arranged at the first narrow pitch, and the concave portions 51 and the convex portions 53 are alternately and continuously formed. The concave portions 51 are arranged at the second wide pitch, and the wide convex portions 54 are formed in the concave portions 51. It is formed alternately and continuously. That is, the first row of projections and depressions in the X direction on the front side in FIG. 2 is formed such that the concave portions 51 and the convex portions 53 and the concave portions 51 and the wide range convex portions 54 are alternately and continuously formed in the width direction of the substrate 210. The In the figure, the X direction, the Y direction, and the Z direction are directions orthogonal to each other (hereinafter the same).

  When the blade mold part 300 returns the upper blade mold 310 to the position before pressing along the Z axis, the supply system 340 has the above-mentioned base material feed amount as shown in FIG. The material 210 is sent out in the Y direction by the roller pair 342. The blade mold portion 300 moves the upper blade mold 310 and the lower receiving blade mold 330 in the X direction as shown in FIG. 9B in parallel with or after the substrate feed by the supply system 340. The amount of movement at this time is a half pitch shorter than half of the first pitch in which the recesses 51 are arranged at narrow intervals. This movement amount becomes the phase shift of the unevenness of each column adjacent in the Y direction in FIG.

  When the upper blade mold 310 and the lower receiving blade mold 330 are moved, the blade mold section 300 moves the upper blade mold 310 up and down again and presses against the substrate 210 as shown in FIG. . Thus, the new recesses 51 are arranged in a phase shifted by the above half pitch with respect to the unevenness due to the continuation of the recesses 51 and the protrusions 53 formed in FIG. Concavities and convexities are formed adjacent to each other in the Y direction. In such an adjacency in the Y direction, as shown in FIG. 2, the bottom of the recess 51 and the top 53a of the projection 53 are connected, and the bottom of the recess 51 and the top 54a of the wide projection 54 are connected. A mesh-like flow path in which the surrounded through holes 41 are continuous is formed. Thereafter, as shown in FIG. 10B, the blade mold part 300 returns the upper blade mold 310 and the lower receiving blade mold 330 to their original positions corresponding to the half pitch. Repeat each step. As shown in FIG. 3 and FIG. 7, the repetition of the process in the 40 W press form described above spans a range in which the normal region 40N and the wide-area convex portion region 40W are continuous in the flow channel width direction (width direction of the substrate 210). Done.

  The blade mold part 300 continues the press in the 40N press form (see FIG. 6) using only the concave portions 51 arranged at the narrow first pitch following the 40W press form (see FIG. 6). In this press form transition, as shown in FIGS. 6 to 7, the blade mold part 300 moves the upper blade mold 310 and the lower receiving blade mold 330 at the press position in the 40 W press form to the right in both the above figures. Slide over a wide range. Thereby, in the base material width of the base material 210 (that is, the flow path width of the gas flow path forming member 40), the convex blade portions 312 and the concave blade portions 332 are alternately arranged at a narrow first pitch, The press (40N press form) by these becomes possible. FIG. 11 is an explanatory view showing a first stage of press forming in a 40N press form, FIG. 12 is an explanatory view of a second stage of press forming in a 40N press form, and FIG. 13 is a third stage of press forming in a 40N press form. It is explanatory drawing which shows a step.

  In the 40N press form of FIG. 6, as shown in FIG. 11A, the supply system 340 feeds the base material 210 in the Y direction by the roller pair 342 with the feed amount already described. The blade mold 300 presses the upper blade mold 310 up and down in the Z-axis direction as shown in FIG. In this case, as shown in the figure, since only the convex blade portion 312 and the concave blade portion 332 act on the base 210 at a narrow first pitch, the concave portion 51 is formed on the base 210 at a narrow first pitch. The concave portions 51 and the convex portions 53 are alternately and continuously formed side by side.

  When the blade mold portion 300 returns the upper blade mold 310 to the position before pressing along the Z-axis, the supply system 340 uses the base material feed amount described above as shown in FIG. The material 210 is sent out in the Y direction by the roller pair 342. The blade mold portion 300 moves the upper blade mold 310 and the lower receiving blade mold 330 in the X direction as shown in FIG. 12B in parallel with or after the substrate feed by the supply system 340. The amount of movement at this time is a half pitch shorter than half of the first pitch in which the recesses 51 are arranged at narrow intervals. This movement amount becomes the phase shift of the unevenness of each column adjacent in the Y direction in FIG.

  When the upper blade mold 310 and the lower receiving blade mold 330 are moved, the blade mold section 300 moves the upper blade mold 310 up and down again and presses against the substrate 210 as shown in FIG. . Thus, the unevenness due to the continuation of the new concave portion 51 and the convex portion 53 is Y in the arrangement shifted in phase by the above-mentioned half pitch with respect to the concave and convex portion due to the continuation of the concave portion 51 and the convex portion 53 that have been formed in FIG. It is formed adjacent to the direction. As shown in FIG. 2, in the adjacency in the Y direction, the bottom of the recess 51 and the top 53a of the projection 53 are connected, and the through-hole 41 surrounded by the bottom and the top 53a is continuous. A path is formed. Thereafter, as shown in FIG. 13B, the blade mold part 300 returns the upper blade mold 310 and the lower receiving blade mold 330 to their original positions corresponding to the half pitch. Repeat each step. The repetition of the process in the 40N press form described above is performed over the entire area in the flow path width direction (width direction of the substrate 210) over the range of the normal area 40N, as shown in FIGS.

  In this embodiment, the press in the 40W press form and the press in the 40N press form are repeated as shown in FIG. 7, so that the gas flow path forming member 40, which is an expanded metal obtained through the press, is a gas A plurality are connected in the flow path direction. Therefore, the gas flow path forming member 40 is obtained by passing through the cutting in the feeding direction of the base material 210 following the pressing in the blade mold part 300. The same applies to the gas flow path forming member 60, but for the gas flow path forming member 60 on the anode side, an expanded state in which the concave portions 51 are arranged at a narrow first pitch and the concave portions 51 and the convex portions 53 are alternately continued. Can be metal. In manufacturing the fuel cell 20 having the gas flow path forming members 40, 60 thus obtained, and thus the fuel cell stack 100, first, the obtained gas flow path forming members 40, 60 are placed on the top of the convex portion 53. The portions 53a and the top portions 54a of the wide-area convex portions 54 are arranged and laminated so as to contact the MEGA 35. Thereafter, the fuel cell 20 is manufactured by being sandwiched between the separator 70 and the separator 80, and the fuel cell stack 100 is obtained by stacking them as shown in FIG.

  Next, as shown in FIG. 3, the advantage of providing the wide convex region 40W in the gas flow path forming member 40 will be described. FIG. 14 is an explanatory diagram schematically showing the relationship between the power generation distribution of the electrolyte membrane 31 in the power generation body layer 35 of the fuel cell 20 and the flow paths of air and gas in normal temperature operation and high temperature operation. As shown in the figure, in the fuel cell 20 of the present embodiment, the gas flow path forming member 40 has an air flow path (from the lower end in the drawing) toward the other end (upper end in the drawing) of the power generation layer 35 ( 1). This air flow path includes the through-hole 41 surrounded by the bottom of the recess 51 and the top 53a of the protrusion 53, and the through-hole 41 surrounded by the bottom of the recess 51 and the top 54a of the wide-area protrusion 54. This is a mesh-like flow path. Further, the separator 80 of the fuel cell 20 has a cooling water flow path (shown in the figure) from one end (left end in the figure) to the other end (right end in the figure) of the power generation layer 35 so as to be orthogonal to the air flow path described above. 1).

  In the region upstream of the flow path that is the air inflow side (supply side), since there is a large amount of unconsumed gas because it is on the gas inflow side, the amount of air passing increases, and the mesh of the gas flow path forming member 40 is increased. The amount of moisture taken away by air passing through the channel is increased. For this reason, the drying of the electrolyte membrane 31 is expected to proceed in the region upstream of the air flow path. In addition, since the cooling water flows through the flow path of the separator 80 while taking heat accompanying the power generation in the power generation body layer 35, the cooling water temperature becomes higher on the cooling water outflow side from the separator 80. For this reason, in the region that is both the cooling water outflow side and the air flow path upstream side, the refrigerant temperature is high. Therefore, the effect of suppressing the temperature rise of the electrolyte membrane 31 is reduced by that amount, and the moisture removal is increased. There is a concern that the film 31 may proceed from drying. In the figure, a region which is both the cooling water outflow side and the air flow path upstream side is shown as a dry sensible area. In the above-described dry sensible region during normal temperature operation, a decrease in power generation capacity due to the drying of the film is observed, and in high temperature operation, a site where a decrease in power generation capacity is observed spreads. For this reason, in the fuel cell 20 of the present embodiment, the region overlapping the dry sensible region during high temperature operation in FIG. 14, that is, the region that is both the cooling water outflow side and the air flow path upstream side is shown in FIG. The wide convex region 40W was used.

  In this wide area 40W, as shown in FIG. 2, the wide area 54 is connected to the recess 51 in the direction (X direction) intersecting the air flow direction, and along the air flow direction (Y direction). Connects the bottom of the recess 51 and the top 54 a of the wide projection 54, and the through hole 41 is formed by the recess 51 and the wide projection 54. The through hole 41 formed by the concave portion 51 and the wide convex portion 54 is located between the concave portions 51 having the wide convex portion 54 formed at a wide pitch. It becomes larger than the hole 41. The top 54 a of the wide-area convex portion 54 that surrounds the through-hole 41 on the power generator layer 35 side is the top of the convex portion 53 that surrounds the through-hole 41 formed by the continuation of the concave portion 51 and the convex portion 53 on the power generator layer 35 side. The power generator layer 35 is brought into contact with an area wider than the top 53a. For this reason, in the wide-area convex portion area 40W, the top portion 54a of the wide-area convex portion 54 covers the surface layer of the power generation body layer 35 so as to prevent gas diffusion (penetration) into the power generation body layer 35. When air passes through the mesh-shaped flow path, the area where the air contacts the surface layer of the power generation body layer 35 can be reduced, and moisture removal due to the passing air is suppressed. In other words, in the fuel cell 20 of the present embodiment, a region that is both on the cooling water outflow side and on the upstream side of the air flow path and is likely to proceed from the drying of the electrolyte membrane 31 is a wide range capable of suppressing moisture removal. Since it is set as the convex part area | region 40W, drying of the electric power generation body layer 35 can be suppressed. As a result, according to the fuel cell 20 of the present embodiment, by suppressing the drying of the electrolyte membrane 31, it is possible to improve the power generation performance not only during normal temperature operation but also during high temperature operation.

  Further, in the fuel cell 20 of the present embodiment, since the area covering the surface layer of the power generator layer 35 by the top 54a in the wide area 40W of the wide area is widened, oxygen in the air permeates the power generator layer 35 correspondingly. It becomes difficult to suppress the consumption of air (oxygen). For this reason, unconsumed air (oxygen) can easily reach the downstream side of the air flow path (see FIG. 3) from the wide convex region 40W, and the electrochemical reaction is activated, thereby increasing the power generation capacity. As a result, according to the fuel cell 20 of the present embodiment, the power generation capacity of the entire battery can be increased by making the power generation distribution uniform throughout the fuel cell.

  In the present embodiment, the blade mold part 300 used for manufacturing the gas flow path forming member 40 is a mold wider than the flow path width of the gas flow path forming member 40, and the blade mold part 300 is narrow. The convex blade portions 312 are arranged in the mold width direction at the first pitch, and the convex blade portions 312 are arranged in the mold width direction at the second wide pitch. Then, the convex blade portions 312 arranged at the narrow first pitch and the convex blade portions 312 arranged at the second wide pitch following thereto are continuously connected in the normal region 40N and the wide convex region 40W in the flow path width direction. Used for the press formation of the flow channel region (40W press configuration: see FIGS. 3, 6 to 7), and the press formation of the flow channel region where the entire channel width is the normal region 40N (40N press configuration: FIGS. 3 and 6). (See FIG. 7), by sliding the blade mold portion 300 (specifically, the upper blade mold 310 and the lower receiving blade mold 330) in the mold width direction, the convex blade portions 312 arranged at a narrow first pitch. Only to use. As a result, according to the gas flow path forming member manufacturing method of the present embodiment, the gas flow path forming members 40 and 60 as expanded metals that can contribute to improvement of power generation performance through suppression of drying of the electrolyte membrane 31 are made of metal. It can be easily manufactured by an existing method of pressing a mold against the substrate 210. Moreover, the press formation of the flow channel region in which the normal region 40N and the wide-area convex region 40W are continuous in the flow channel width direction (40W press form: see FIGS. 3, 6 to 7), and the entire flow channel width is the normal region 40N. Since the press formation (40N press form: see FIG. 3, FIG. 6 to FIG. 7) of the flow path area can be switched by the sliding movement of the blade mold part 300, it is not necessary to replace the mold, thereby reducing the man-hours. As a result, the cost can be reduced.

  As mentioned above, although the embodiment of the present invention has been described in the embodiments, the present invention is not limited to the above-described embodiments and modifications, and can be implemented in various modes without departing from the gist thereof. Is possible. For example, in the above-described embodiment, the region that is both the cooling water outflow side and the air flow path upstream side is the region where the drying of the electrolyte membrane 31 is easy to proceed, and the region is defined as the wide convex region 40W. It is not limited to. If the drying proceeds on the flow path end side separated in the gas flow path direction from the wide-area convex area 40W in FIG. 3, the wide-area convex area on the gas flow path end side and also on the cooling water flow path end side. It can also be 40W. That is, in FIG. 3, a partial region on the flow channel end side of the normal region 40N aligned with the wide-area convex region 40W in the gas flow channel direction can be the wide-area convex region 40W.

DESCRIPTION OF SYMBOLS 20 ... Fuel cell 30a ... Hydrogen supply manifold 30b ... Air supply manifold 30c ... Hydrogen discharge manifold 30d ... Air discharge manifold 30e ... Cooling water supply manifold 30f ... Cooling water discharge manifold 31 ... Electrolyte membrane 32a ... Cathode electrode 32b ... Anode electrode 33a ... Gas diffusion layer 34 ... MEA
35 ... Power generation layer 36 ... Seal gasket 40 ... Gas flow path forming member 40N ... Normal region 40W ... Wide area convex region 41 ... Through hole 51 ... Recessed portion 53 ... Convex portion 53a ... Top portion 54 ... Wide area convex portion 54a ... Top portion 60 ... Gas flow path forming member 70 ... Separator 71 ... Cathode side separator 71a ... Hydrogen supply manifold 71b ... Air supply manifold 71c ... Hydrogen discharge manifold 71d ... Air discharge manifold 71e ... Cooling water supply manifold 71f ... Cooling water discharge manifold 72 ... Intermediate Separator 72a ... Hydrogen communication hole 72b ... Air communication hole 73 ... Anode separator 75 ... Air communication hole 76 ... Air communication hole 80 ... Separator 95 ... End plate 95a ... Hydrogen supply manifold 95b ... Air supply manifold 95c ... Hydrogen exhaust manifold Hold 95d ... Air discharge manifold 95e ... Cooling water supply manifold 95f ... Cooling water discharge manifold 100 ... Fuel cell stack 210 ... Substrate 300 ... Blade part 310 ... Upper blade type 312 ... Convex blade part 320 ... Lower blade type 330 ... Lower Receiving blade type 332 ... Concave blade 340 ... Supply system 342 ... Roller pair

Claims (5)

A fuel cell,
A power generator layer including a membrane electrode assembly in which an electrode is bonded to each membrane surface of the electrolyte membrane;
A pair of separators that are arranged with the power generation layer sandwiched therebetween and that are involved in the supply and discharge of the reaction gas used in the power generation reaction in the power generation layer;
A flow that is disposed between the power generation layer and at least one of the pair of separators and forms a mesh-like flow path that allows the reaction gas from the separator to flow in the gas flow direction along the membrane surface of the electrolyte membrane. A road forming member,
The flow path forming member is:
The portion surrounding the mesh-shaped flow path has a wide and narrow difference in the contact part area that contacts the power generation body layer, and based on the flow rate of the reaction gas passing through the flow path, the electrolyte membrane of the power generation layer A fuel cell in which the mesh-like flow path having a wide contact area is formed in a range where drying is expected to occur more easily than other electrolyte membrane locations.   The fuel cell according to claim 1, wherein the flow path forming member is an expanded metal. The fuel cell according to claim 1 or 2, wherein
The separator is configured such that the flow path of the cooling medium for cooling the power generation body layer intersects the flow direction of the gas in the mesh-shaped flow path formed by the flow path forming member. Prepared,
The flow path forming member has an area on the flow path end side in the flow path of the refrigerant and on the upstream side of the flow path of the reaction gas in the mesh flow path as a range in which the electrolyte membrane is easily dried. A fuel cell in which the mesh-like flow path having a wide contact area is formed in a region. An apparatus for producing expanded metal for fuel cells,
A supply section for feeding out metal plate materials;
By pressing a metal mold having convex blade parts arranged in the mold width direction against the metal plate material fed by the supply unit, recesses and projections are alternately continuous in the plate width of the plate material. A press portion for press-forming the mesh-shaped flow path,
The mold is
The width of the mold is wider than the flow path width of the mesh-shaped flow path, and the width of the mold corresponds to the flow width of the first flow path of the mesh-shaped flow path and the remaining range of the mold. Dividing into the second mold width part, the pitch of the convex blade part in the first mold width part is narrower than the pitch of the convex blade part in the second mold width part, A convex blade portion is provided side by side with the first and second metal width portions,
The press section is
Holding the mold slidably along the mold width direction,
Press formation of the mesh-like flow path over the flow path width by the convex blade parts arranged in the first mold width, and the convex blades arranged in the second mold width part Press forming the mesh-shaped flow path across the flow path width by the convex blade portion in the first mold width continuous with the second mold width section. An apparatus for producing expanded metal for a fuel cell, which is switched by sliding along the mold width direction. A method for producing expanded metal for a fuel cell, comprising:
A delivery process for delivering a metal plate;
By pressing a mold having convex blade portions arranged in the mold width direction against the metal plate material to be sent out, a mesh-like structure in which concave portions and convex portions are alternately continuous in the flow path width. A press process for press forming the flow path,
In the pressing process,
A mold width wider than the flow path width is divided into a first mold width section corresponding to the flow path width of the mesh-shaped flow path and a remaining second mold width section, and the first mold width section The mold having the convex blade portion is arranged so that the pitch of the convex blade portion is narrower than the pitch of the convex blade portion in the second mold width portion. Slidable along the direction,
Press formation of the mesh-like flow path over the flow path width by the convex blade parts arranged in the first mold width, and the convex blades arranged in the second mold width part Press forming the mesh-shaped flow path across the flow path width by the convex blade portion in the first mold width continuous with the second mold width section. A method for producing expanded metal for a fuel cell, which is switched by sliding along the mold width direction.

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