JP2006054198A - Separator for fuel cell utilizing multiple recess and projection board and bending processing die for multiple recess and projection board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separator for a fuel cell utilizing a multiple recess and projection board which has no constraint in the shape and spacing of the recess and projection portions and is superior in productivity. <P>SOLUTION: This is the separator for the fuel cell utilizing the multiple recess and projection board in which a plurality of mutually independent recess and projection portions are formed on both front and rear faces of a plate material 57. The separator has a plurality of stripes of first grooves 58 on at least one face of a plate 57 of the base material which are formed by reducing the thickness of the plate, and second grooves 59 which are formed on both the front and rear faces of the plate by applying a bending process on the plate so as to have a corrugated continuous bending shape in which the trough lines and crest lines cross these first grooves 58. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is for a fuel cell using a multiple uneven plate provided with a relatively large number of uneven portions by forming a plurality of recesses or protrusions on at least one surface while forming a plate shape as a whole. The present invention relates to a separator and a bending die for bending the multiple uneven plate.

  A plate-like material having a plate shape as a whole and provided with a plurality of protrusions (convex portions) and depressions (concave portions) associated with forming the protrusions on one or both surfaces thereof, that is, a multiple uneven plate, It is used in various fields. This type of multiple concavo-convex plate is obtained by increasing the moment of section by providing convex portions and concave portions, or improving the strength of the plate-like body, or the convex portions and concave portions are plate-like bodies. There are a variety of uses or functions, such as increasing the overall surface area of the material, and further, the convex portion functions as a contact or as a support.

  Regardless of the multiple concave and convex plates, the convex portions and concave portions need to be integrated with the flat plate portion which is the base portion. Therefore, as a manufacturing method thereof, a plate body such as a metal plate as a material is pressed. A method of deforming in the plate thickness direction by, for example, is fundamental. In addition, if the function required for the convex portion is different from the flat plate portion that is the base portion, the material of the convex portion and the flat plate portion will be different. In such a case, the axis that becomes the convex portion In this case, the pin-like member or the pin-like member is joined in the standing state. As a method of manufacturing such a multiple uneven plate having different materials for the convex portion and the flat plate portion, a method for joining the convex part to the flat plate body by welding or adhesion, There is a method in which the convex part is integrated with the base part by so-called caulking in which the part part is inserted and then the convex part is crushed.

  If a method of forming a convex part or a concave part by partially deforming a metal plate as a raw material in manufacturing the above-described multiple concave and convex plates, the material will be elongated or flowed. However, even if a metal material with excellent ductility is used, its height and flow are limited, so the height of the convex part or the depth of the concave part that can be formed is about 1.5 times the thickness of the material. In many cases, the required uneven shape cannot be obtained. As a method of solving such inconvenience, there is a method of repeating drawing and ironing a plurality of times. However, in such a method, there is a problem that the number of processing steps is increased and productivity is lowered. There is an inconvenience limited only when the material can be sufficiently supplied to the recess.

  Furthermore, especially in the case of multiple concavo-convex plates in which a large number of convex portions and concave portions are formed close to each other, the material that can be supplied to each convex portion and concave portion when the convex portions and concave portions are close to each other. In this respect, the height of the convex part and the depth of the concave part are restricted, and in general, the ratio of the diameter and pitch of the concave and convex parts must be set to 2.5 or more. However, there is a disadvantage that the shape of the multiple uneven plate is limited.

  On the other hand, in the method of manufacturing a multiple uneven plate by joining convex parts to a flat plate, there is no restriction on the shape as described above because the material is not deformed. However, if welding is performed for joining, melting of the material will occur, so if the convex part is as small as a few millimeters and the interval is small, the convex part itself will melt and disappear. There is a high possibility that On the other hand, if an adhesive is used, it is difficult to ensure the conductivity between the convex portion and the flat plate portion, and the bonding strength and durability may be insufficient.

  Instead of this, if the convex portion is joined to the flat plate body by caulking, it is necessary to form a prepared hole in the flat plate body for inserting the convex component, and there is a disadvantage that the number of processing steps increases. . In order to facilitate the insertion of the convex part, the pilot hole has an inner diameter larger than the outer diameter of the convex part, and the gap between them is sealed by caulking the convex part. However, even if the caulking process can compensate for the integration of the convex part and the flat plate, it is difficult to ensure airtightness. It cannot be adopted as a method.

  Thus, conventionally, when manufacturing a multi-concave plate, due to processing restrictions, the height of the convex portions and the depth of the concave portions cannot be increased, or the interval between them must be increased. There were inconveniences such as the shape of the uneven plate being restricted. In addition, in order to eliminate such inconveniences, the actual situation is that other inconveniences such as increased processing costs and reduced reliability, such as increased product costs and reduced quality, occur. there were.

  The present invention has been made against the background described above, and is a fuel cell separator using a multi-concave plate having no restrictions on the shape and interval of the uneven portions and having high productivity, and the separator. An object of the present invention is to provide a bending die for bending a multi-concave plate.

  In order to achieve the above object, the invention of claim 1 is directed to a separator for a fuel cell that uses a multiple concavo-convex plate in which a plurality of concavo-convex portions independent from each other are formed on the front and back surfaces of the plate material. A plurality of first groove portions formed by reducing the plate thickness on at least one surface, and a bend shape that is continuous in a wave shape in which valley lines and mountain lines intersect with the first groove portions. It has a 2nd groove part formed in the front and back both surfaces of the said board | plate material by bending a board | plate material, It is characterized by the above-mentioned.

  According to a second aspect of the present invention, in the first aspect of the invention, the groove formed on the one surface forms a flow path for cooling water, and the groove formed on the other surface forms a gas flow. A separator for a fuel cell using a multiple uneven plate, characterized in that a path is formed.

  Further, the invention of claim 3 is the invention of claim 2, wherein the shape or arrangement of the upstream first groove portion and the shape or arrangement of the downstream first groove portion in the flow direction of the cooling water are different. A separator for a fuel cell using a multi-concave plate, characterized in that

  Furthermore, the invention of claim 4 is the third invention, wherein in the invention of claim 1, a third portion formed so as to intersect the mountain line at a portion corresponding to the mountain line on the other surface of the plate member with the bending process. The first groove portion and the second groove portion on the one surface form a flow path for cooling water, and the second groove portion and the third groove portion on the other surface serve as a flow path for gas. A separator for a fuel cell using a multiple uneven plate characterized by being formed.

  According to a fifth aspect of the present invention, in the first aspect of the invention, a predetermined portion of the portion corresponding to the mountain line on the other surface of the plate member is pressed and deformed in the plate thickness direction so that the cross-sectional area is larger than that of the third groove portion. A separator for a fuel cell using a multiple uneven plate, wherein a large fourth groove is formed.

  Further, the invention of claim 6 is a method in which a plate material in which a plurality of grooves having a plate thickness thinner than the other portion is formed on only one surface is subjected to a bending process in which peaks and valleys continue in a direction intersecting the grooves. A bending die for a multi-concave plate, which obtains the multi-concave plate as described in 1, characterized in that it has a protrusion that restricts deformation of the groove.

  Therefore, according to the first aspect of the present invention, there is provided a separator for a fuel cell using a multiple uneven plate in which a plurality of independent uneven portions are formed on both front and back surfaces of a plate material, and at least one surface of the plate material as a material In addition, a plurality of first groove portions formed by reducing the plate thickness, and the plate material is bent so as to have a continuous bent shape so that valley lines and mountain lines intersect the groove portions. Thus, the convex portion defined by the first groove portion and the second groove portion is a contact point that is electrically connected to the electrode in the fuel cell. Moreover, these groove portions can be used as flow paths for gas and refrigerant.

  According to the invention of claim 2, in addition to the same effect as that of the invention of claim 1, the groove formed on the one surface forms a flow path for cooling water and is formed on the other surface. Since the formed groove portion forms the gas flow path, the gas flow path and the cooling water flow path can be formed by a single separator or a pair of separators.

  Furthermore, according to the invention of claim 3, in addition to the same effect as that of the invention of claim 1 or 2, the shape or arrangement of the upstream first groove portion in the flow direction of the cooling water and the first downstream side are provided. Therefore, the flow rate of the cooling water dispersed in the second groove part via the first groove part is controlled by the shape or arrangement of the first groove part, It is possible to secure a sufficient amount of cooling water for each groove and prevent the occurrence of defective cooling.

  Furthermore, according to the invention of claim 4, in addition to the same effect as that of the invention of claim 1, the mountain line intersects with the mountain line at a portion corresponding to the mountain line of the other surface of the plate material with the bending. The first groove and the second groove on the one surface form a cooling water flow path, and the second groove and the third groove on the other surface. Since the groove portion of this plate formed a gas flow path, one surface side of the plate member is used as a cooling portion in which cooling water flows, and the other surface is used to supply and discharge gas supplied for power generation in the fuel cell. Moreover, since the groove portions are formed so as to intersect with each other, dispersion of the cooling water and the gas can be promoted.

  And according to invention of Claim 5, in addition to the effect similar to invention of Claim 1, the predetermined location of the part equivalent to the mountain line of the other surface of the said board | plate material is press-deformed in the plate | board thickness direction, and the said Since the fourth groove portion having a larger cross-sectional area than the third groove portion is formed, a liquid such as water droplets in the gas flow path is fed into the fourth groove portion, or another second groove portion through the fourth groove portion. As a result, the clogging of the second groove by the droplets can be eliminated, and the gas can be distributed and dispersed well.

  According to the invention of claim 6, when bending the multi-concave plate used as the separator according to the invention of claim 1, the deformation of the groove on the one surface can be prevented while the other A groove at the top of the crest portion of the surface of the plate can be surely formed, and as a result, a large number of concavo-convex portions independent from each other protrude greatly with respect to the plate thickness and are formed close to each other. Can do.

  Next, the present invention will be specifically described with reference to the drawings. First, an example of the multiple uneven plate 1 used as a separator for a fuel cell in the present invention will be described. The example shown in FIG. 1 is separated in both directions on both the front and back surfaces of the flat plate portion 2 as a base portion. A number of arranged convex portions 3 are provided. The flat plate portion 2 and the convex portion 3 are made of the same metal material, or are made of different kinds of metal materials. Moreover, although the convex part 3 and the flat plate part 2 are completely integrated in the state of a product, these are separate parts, and the components which comprise the convex part 3 are closely_contact | adhered to the parts which comprise the flat plate part 2 It is configured by fitting.

  Here, the relationship between the dimensions of each part in the multiple uneven plate 1 will be described. The height h of the convex part 3 is set to 1.5 times or more the plate thickness t of the flat plate part 2, and the outside of the convex part 3 The diameter d is set to be equal to or less than the pitch p between the convex portions 3. As an example, the plate thickness t is 0.3 mm, the height h of the convex portion 3 is 0.6 mm, the outer diameter d of the convex portion 3 is 1.0 mm, and the pitch p is 1.0 mm. In addition, if the flat plate part 2 is used as a reference, the convex parts 3 are formed on both front and back surfaces, but assuming a plane connecting the tips of the convex parts 3, The part between the convex parts 3 will be depressed, and it can also be said that the recessed part is formed here. In that case, the depth of the recess is 1.5 times or more the plate thickness t.

  Below, the manufacturing method of the multiple uneven | corrugated board 1 shown in FIG. 1 is demonstrated. The multiple uneven plate used in the present invention can be constituted by a single flat plate. The flat plate 20 shown in FIG. 2A is made of an appropriate metal or alloy such as aluminum, and first, a plurality of grooves 21 parallel to each other are formed on both the front and back surfaces of the flat plate 20. The grooves 21 are not formed by bending the flat plate body 20 but are formed by the flow or removal of a material such as coining or cutting. Therefore, the plate thickness at the portions of these grooves 21 is the groove 21. It is thinner than the thickness of the other parts. Further, the groove 21 on the front surface side and the groove 21 on the back surface side are shifted by a half pitch in the direction intersecting the longitudinal direction as shown in FIG. In addition, when an example of the dimension of each part of the flat plate 20 is shown here, the plate thickness is 0.3 mm, and the width and depth of the groove 21 are each 0.15 mm.

  When the groove 21 is formed by coining, the depth is 50% or less of the plate thickness. This is to limit the amount of material that is removed by coining and rises between the grooves 21 while maintaining the life of the mold used for coining. When the amount of the material that rises between the grooves 21 increases, work hardening occurs at that portion, and there is a high possibility of cracking during wave bending described later. In the case where annealing is performed after the groove 21 is formed by coining or similar material flow, the groove 21 may be formed at a depth of 50% or more of the plate thickness.

  Next, a wave bending process (wave bending process) is applied to the flat plate 20 shown in FIG. The wave bending process is a process of bending into a shape in which the crests and troughs in the cross section are alternately continuous in one direction, and the crest line 22 or trough line 23 is the groove. Wave bending is performed so as to intersect with 21. The height of the crest portion or the depth of the trough portion generated by the wave bending process, that is, the dimension between the top of the crest portion and the bottom of the trough portion is 1.5 times the plate thickness of the flat plate 20. That's it.

  The peak portion formed by wave bending in this way is a direction in which the wave bending direction intersects the groove 21 at right angles or obliquely, and therefore, the mountain line is formed by the groove 21 remaining after the wave bending. It is divided in the direction. And the part of each mountain divided in this way is the convex part 24. Since the grooves 21 are formed on both the front and back surfaces of the flat plate 20 and the wave bending forms the same bent state on the front surface side and the back surface side, the convex portions 24 are formed on both front and back surfaces of the flat plate body 20. It is formed similarly. The positions of the convex portions 24 on the front surface side and the convex portions 24 on the back surface side are shifted by a half pitch.

  The multi-concave plate 25 manufactured in this way has a height of the convex portion 24 or a depth of the concave portion opposite thereto that is 1.5 times or more the plate thickness. Further, the pitch of the convex portion 24 or the concave portion can be arbitrarily set in the direction along the groove 21 according to the pitch at the time of wave bending, and the pitch in the direction intersecting with this is set to the pitch of the groove 21. can do. That is, the pitch can be smaller than the maximum outer dimension of the convex portion 24.

  In the shape shown in FIG. 2B, the top of the convex portion 24 is formed flat. However, in this shape, a flat surface is formed on the processing die for wave bending. Can be obtained. In addition, FIG. 2 shows a shape in which the edge clearly appears by grooving and wave bending, but this is schematically shown, and when the machining is actually performed, the edge Parts and bent parts appear as curved surfaces.

  Here, an example of the shape of the groove 21 formed in the flat plate 20 is as shown in FIGS. The example shown in FIG. 3A is an example in which the grooves 21 are formed on both the front and back surfaces of the flat plate 20 with a half pitch shift. The example shown in FIG. 3B is an example in which the grooves 21 are formed at the same position in the width direction of the front and back surfaces of the flat plate 20. Although not particularly illustrated, a groove may be formed on only one of the front and back surfaces of the flat plate 20, and the thickness of the portion may be reduced. Even when a groove is formed only on one surface, when the flat plate body is wave-bent as described above, the tip of a so-called peak portion is formed at a thick portion where the groove portion is removed. The largest tension acts on the part, and as a result, material flow occurs in that part, and a slight groove is formed so as to cross the mountain line. Therefore, even with a flat plate with grooves formed on only one surface, by applying wave bending, continuous peaks associated with wave bending are separated by grooves generated in the crossing direction at the top, and independent multiple Are formed. Thus, in the processing method for forming the groove only on one surface of the flat plate, the mold having the protrusions for forming the groove is only one of the upper and lower molds, and thus the wear mold is either the upper or lower one. Therefore, the cost required for the mold can be reduced.

  Further, the bending shape by wave bending may be a shape having a cross-sectional shape in which arcs are continuous as shown in FIG. Furthermore, when the flat plate body 20 on which the grooves 21 are formed in advance is wave-bending, the flat plate body 20 may be subjected to complicated stress in the surface direction, and the shape of the grooves 21 may be lost. Moreover, when the groove | channel 21 is formed only in one surface, in order to produce a groove | channel reliably in the top part of the peak part in the other surface, it is desired to produce a material flow appropriately. Therefore, as shown in FIG. 5, a projection 26 that fits into a previously formed groove 21 is formed on a bending die used for wave bending. The protrusions 26 may be continuous as shown in FIG. 5, or formed only at a location corresponding to the top of the mountain and a location corresponding to the bottom of the valley at the time of wave bending. It may be. Moreover, since this protrusion 26 is for shape | molding the shape of the part of the groove | channel which divides the convex part 24 into the target shape, it is the shape which necessarily closely_contact | adheres to the groove | channel 21 formed previously, and fits it. Need not be. Further, the protrusion 26 may be formed on both or one of the processed surfaces of the punch 27 and the die (not shown) constituting the wave bending mold.

  In each of the specific examples described above, an example is shown in which the cross section when cut in the plane direction of the flat plate portion forms a concave or convex portion having a circular cross section. However, in the present invention, the cross section is a rectangular cross section. Or you may form the recessed part or convex part used as a polygon. Moreover, although the example in which the cross section in the direction perpendicular to the flat plate portion forms a rectangular or cup-shaped concave portion or convex portion is shown in the above specific example, the sectional shape of the concave portion or convex portion in this invention is the above example. It is not limited to what was shown, and it can be made into an appropriate shape as needed. The multiple uneven plate is used as a separator in a solid oxide fuel cell stack.

  Next, an example in which the above-described multiple uneven plate is used for a fuel cell separator will be described. FIG. 6 is a schematic cross-sectional view showing a part of a polymer electrolyte membrane fuel cell stack, on both sides of an electrolyte membrane 50 that allows ions such as protons to pass through, a catalyst reaction layer, a gas diffusion layer, and The electrodes 51 and 52 containing are provided. The electrolyte membrane 50 is formed of, for example, an ion exchange membrane that exhibits cation permeability in a wet state, and the electrodes 51 and 52 are formed by ionization or ionization of fuel gas and oxidizing gas (air). It comprises a catalyst layer for promoting the reaction and a porous diffusion layer for diffusing gas to the catalyst layer. Separators 53 made of multiple concavo-convex plates are arranged in close contact with the surfaces of the respective electrodes 51 and 52.

  These separators 53 are made of a conductive material (for example, metal), and are arranged so that the top surface of the convex portion or the bottom surface of the concave portion is brought into close contact with the electrode to maintain an electrically conductive state. Therefore, since the separator 53 is a multiple concavo-convex plate, a large number of hollow portions separated from the surfaces of the electrodes 51 and 52 are formed so as to communicate with each other at regular intervals. For example, the gas flow path 54 is configured to flow a hydrogen gas) and an oxidizing gas (for example, air).

  A single cell (single cell) 55 is configured by sandwiching the electrolyte membrane 50 and the electrodes 51 and 52 stacked above each other with a pair of separators 53. A large number of these single cells 55 are stacked in the thickness direction. The fuel cell stack 56 is configured. In that case, the convex portions or the concave portions of the separators 53 in the single cells 55 adjacent to each other are abutted with each other. Therefore, there are portions that are deformed in the direction of being separated from each other adjacent to the abutted portions. The portions communicate with each other, and a cooling water channel 57 is formed here.

  The separator 53 is manufactured by a method in which coining and wave bending are combined in the above-described manufacturing method of the multiple uneven plate. Specifically, as shown in FIG. 7, a plurality of parallel grooves 58 (hereinafter referred to as “coining grooves”) 58 are formed on one surface of a metal plate by coining, and then a mountain line and a valley line are formed. A wave-like bending process is performed so as to intersect these coining grooves 58. As a result, on the surface on which the coining groove 58 is formed, the coining groove 58 and a groove by wave bending (hereinafter, referred to as wave bending groove) 59 intersect with each other. Therefore, a portion surrounded by these grooves 58 and 59 Becomes a convex part.

  On the other hand, on the surface where the coining groove 58 is not formed, “sink marks” occur in the portion corresponding to the mountain line on the surface side and on the back side of the coining groove 58, and a shallow groove (hereinafter temporarily sinked). 60) (denoted as a groove). FIG. 8 shows a cross section of the sink groove 60, where the sum of the depth d2 of the sink groove 60 and the depth d1 of the coining groove 58 on the opposite side is not "sink". The depth d0 of the coining groove 58 in FIG. Therefore, even on the surface that has not been subjected to coining, the portion corresponding to the mountain line on the surface is divided at regular intervals by the sink groove 60, and as a result, a large number of independent convex portions are formed.

  As shown in FIG. 8, the coining groove 58 is about half the thickness of the metal plate, whereas the wave bending groove 59 is formed by bending the metal plate. The depth of the bending groove 59 is considerably deeper than the depth of the coining groove 58. Further, since the sink groove 60 is generated by “sink” accompanying wave bending, the depth thereof is considerably shallower than the coining groove 58. Accordingly, the wave-side grooved grooves 59 on the surface side subjected to coining are communicated with each other by the coining grooves 58 having a cross-sectional area larger than that of the sink groove 60. 58 is a cooling water flow path for circulating the cooling water. On the other hand, the wave bending groove 59 and the sink groove 60 on the surface side not subjected to coining are gas flow paths for allowing a reaction gas such as fuel gas and oxidizing gas to flow.

  By the way, it is preferable that the reaction gas flows along the surfaces of the electrodes 51 and 52 for as long as possible in order to improve the reaction efficiency. Therefore, the gas flow path is formed so that the reaction gas can meander and flow. An example thereof is schematically shown in FIG. The coining groove is formed in the central portion of the opposite surface that does not appear in FIG. The region in which the coining grooves are formed in this way is equally divided into four regions in the vertical direction in FIG. 9, and in each region, the mountain line and the valley line are directed in the horizontal direction in FIG. 9. Wave bending is applied. As a result, the wave bending groove 59 and the sink groove 60 are formed in a direction orthogonal to each other on the gas channel side surface shown in FIG. 9, and the adjacent wave bending grooves 59 communicate with each other by the sink groove 60. ing. In other words, gas flow paths that intersect vertically and horizontally are formed in each region.

  An inlet manifold 61 communicating with all the wave bending grooves 59 in the upper region is formed at one end of the upper region in FIG. Further, an intermediate manifold 62 communicating with all of the wave bending grooves 59 in these regions is formed at one end of the two intermediate regions, and further, all the wave bending grooves in that region are formed at one end of the lower region. An outlet manifold 63 communicating with 59 is formed. These manifolds 61, 62, and 63 are long holes that penetrate the separator 53 in the plate thickness direction, and in order to supply or discharge the reaction gas over the entire fuel cell stack by stacking a large number of single cells. The flow path is formed.

  A wave bending groove 59 that is curved in the vertical direction is formed at the other end of the upper region and the second region from the top so that the wave bending grooves 59 in these regions communicate with each other. The same applies to the third region from the top and the bottom region. Accordingly, the reaction gas supplied from the inlet manifold 61 passes through the gas flow path (that is, the wave bending groove 59 and the sink groove 60) in the upper region to reach one end thereof, and from here the wave bending groove ( The so-called U-turn groove) 59 passes through the gas flow path in the second region from the top to reach the intermediate manifold 62 and flows from here to the gas flow channel in the third region. Thereafter, similarly, the other end portion enters a lower region via a so-called U-turn groove along the vertical direction, and is finally discharged from the outlet manifold 63.

  In FIG. 9, reference numerals 64, 65, and 66 denote through holes, which are formed at positions symmetrical to the respective manifolds 61, 62, and 63 in the left-right direction and stacked as a fuel cell stack. A flow path for other reaction gases is formed. Further, an inlet manifold 67 for cooling water is formed in the lower part of FIG. 9, and an outlet manifold 68 for cooling water is formed in the upper part. These manifolds 67 and 68 are long holes extending in the left-right direction, penetrate the separator 53, and communicate with a cooling water flow path formed on the other surface that does not appear in FIG. 9.

  As described above, the gas flow path is formed by the wave bending groove 59 and the sink groove 60, and the sink groove 60 is a shallow groove caused by “sink” accompanying the wave bending. On the other hand, the electrolyte membrane 50 needs to be in a wet state in order to maintain the cation permeability, and in the fuel cell using hydrogen gas as the fuel gas, water is generated as a reaction product. Therefore, although water droplets may flow into or generate in the gas flow path, the opening cross-sectional area of the sink groove 60 is relatively small with respect to the water droplets, so that the water droplets are clogged in the wave bending groove 59, and the water droplets are Until it is pushed out from the wave bending groove 59, the wave bending groove 59 does not function effectively as a gas flow path, which may cause a decrease in power generation efficiency of the fuel cell. In order to eliminate such inconvenience, the separator 53 is provided with a water droplet removing groove 69.

  The water droplet removing groove 69 will be described in detail. FIG. 10 shows a part of the surface of the separator 53 on the gas flow path side, its AA line cross section and BB line cross section. A wave bending groove 59 is formed and a sink groove 60 is formed at a position corresponding to the coining groove 58 on the back surface side. The part sandwiched between the sink grooves 60 is a convex part that is brought into contact with the electrode, and the part corresponding to the convex part is pushed and bent to the back surface side at predetermined intervals, and the part is the convex part. On the contrary, it is recessed, and a water drop removing groove 69 is formed here. Therefore, the water droplet removing groove 69 is formed by bending at a position avoiding the coining groove 58 on the back surface side (the surface side on which coining is performed). This is to prevent the coining groove 58 from being crushed, and therefore its width W2 is set narrower than the width W1 of the coining groove 58. The depth of the water droplet removal groove 69 may be about the depth of the wave bending groove 59 as an example, as long as it has a cross-sectional area through which the water droplet Wd can pass.

  Therefore, in the separator 53 in which the water droplet removal groove 69 is formed, the gas flow path is not blocked by water droplets or the blockage of the gas flow path can be quickly eliminated. It is possible to efficiently disperse the electrolyte membrane 50 throughout. Therefore, if the separator 53 is used, the power generation efficiency of the fuel cell can be improved.

  The water droplet removing groove 69 corresponds to the fourth groove portion in the invention of claim 5. Further, the coining groove 58 corresponds to the first groove portion in the inventions of claims 1 to 5, and the wave bending groove 59 intersecting with the second groove portion corresponds to the second groove portion, and is not subjected to coining processing. The wave bending groove 59 corresponds to the third groove portion in the inventions of claims 4 and 5.

  The separator 53 is subjected to wave bending to form wave bending grooves 59 on both front and back surfaces. Therefore, like the gas flow path described above, the cooling water flow path is also divided into four regions. The wave bending groove 59 in the region and the lower two regions is in a state of being communicated by the U-turn groove on one end side. A part of the shape is schematically shown in FIG. As shown in FIG. 11, cooling water is supplied to each wave bending groove 59 constituting the cooling water flow path via a coining groove 58 formed in a direction intersecting with the wave bending groove 59. In that case, the coining groove 58 is shallower than the wave bending groove 59, and its opening area (flow channel area) is smaller than the wave bending groove 59, so that it is difficult for cooling water to flow into the coining groove 58 from the wave bending groove 59. . Therefore, the cooling water flow path is configured as described below so that the cooling water can be diffused as evenly as possible over the entire surface of the separator 53 to uniformly cool the whole.

  A cooling water inlet manifold 67 is formed on the lower side of the separator 53, and the cooling water is supplied from here through the coining groove 58 to the wave bending groove 59. Accordingly, the cooling water is first supplied to the wave bending groove 59 closest to the inlet manifold 67, and the cooling water flows along the wave bending groove 59, while a part of the cooling water passes through the other coining grooves 58 and the other. Flows into the adjacent wave bending groove 59 and flows inside the other wave bending groove 59. Thus, since the cooling water is supplied to the wave bending groove 59 far from the inlet manifold 67 via the coining groove 58 shallower than the wave bending groove 59, the wave bending groove near the inlet manifold 67 is supplied. The total opening area of the coining groove 58 that intersects 59 is set larger than the total opening area of the coining groove 58 that intersects the wave bending groove 59 at a distant position.

In particular,
Vm = V1 + V1-2
V1-2 = V2 + V2-3
V2-3 = V3 + V3-4
And (1/2) ^n-1 / Vm = V1
Set the amount of cooling water to satisfy Vm is the amount of cooling water in the inlet manifold 67, V1 is the amount of cooling water in the wave bending groove 59 closest to the inlet manifold 67, and V1-2 is the wave bending groove 59 closest to the inlet manifold 67 and the first adjacent to it. The amount of cooling water in the coining groove 58 connecting the second wave bending groove 59, and so on. Similarly, V2 and V3 are the amount of cooling water in the second wave bending groove 59 and the amount of cooling water in the third wave bending groove 59. The amount of cooling water, V2-3 is the amount of cooling water in the coining groove 58 connecting the second and third wave bending grooves 59, and V3-4 is the coining connecting the third and fourth wave bending grooves 59. The amount of cooling water in the groove 58 is shown respectively. Also, n is the number of wave bending grooves 59, and is “4” in the example shown in FIG.

  Eventually, the amount of cooling water is set so that the coining groove 58 near the inlet manifold 67 increases. This is set by increasing the width or depth of each coining groove 58 to increase the opening cross-sectional area, or by increasing the number of coining grooves 58 toward the inlet manifold 67 side. In the example shown in FIG. 11, the number of coining grooves 58 is increased on the inlet manifold 67 side.

  In order to disperse the cooling water as evenly as possible over the entire surface of the separator 53, it is necessary to promote the dispersion of the cooling water from the inlet manifold 67 to the wave bending groove 59. The shape or arrangement of the coining grooves 58 having a small area is set as described above. Therefore, since the cooling water is already dispersed in the wave bending grooves 59 in the middle flow area or downstream area of the entire cooling water flow path, there is no need to disperse the cooling water via the coining grooves 58. Therefore, in the separator 53 according to the present invention, the shape or arrangement of the coining grooves 58 for promoting the dispersion of the cooling water is adopted at a location near the inlet manifold 67 in the entire cooling water flow path, and on the downstream side from this. Then, the shape or arrangement of the coining grooves 58 is set to be the same between the wave bending grooves 59. That is, the shape or arrangement of the coining grooves 58 corresponding to the first groove portion in the present invention is different between the upstream side and the downstream side in the flow direction of the cooling water.

  Of the wave bending groove 59, the U-turn groove portion has a continuously intersecting angle with the coining groove 58, and the directions of both coincide with each other. It is difficult to form a stable U-turn groove. Therefore, in the example shown in the figure, the coining groove 58 is not formed in the U-turn groove portion. Since the portion up to the middle of the U-turn groove is used for the diffusion of the cooling water, the processing for making the shape or arrangement of the coining grooves 58 different between the wave bending grooves 59 is the same as the U-turn groove. It may be applied in the middle part of the, more specifically in the section from the start end of the U-turn groove until reaching the position turned approximately 45 degrees.

It is a perspective view which shows a part of multiple concavo-convex board by this invention. (A) And (B) is explanatory drawing for demonstrating the process in which a multiple uneven | corrugated board is manufactured by a wave bending process. (A) And (B) is sectional drawing which shows the groove shape which can be employ | adopted by the method shown in FIG. It is sectional drawing which shows an example of the wave bending shape which can be employ | adopted with the method shown in FIG. It is a schematic diagram which shows an example of the bending type | mold which has a protrusion for groove | channel formation. It is a typical fragmentary sectional view of the fuel cell stack using the separator which concerns on this invention. It is a fragmentary perspective view which shows the state before the wave bending process of the board | plate material for separators, and the state in which the sink groove was formed by the wave bending process. It is an expansion partial end view which shows a sink groove. It is a perspective view of the separator which concerns on this invention. It is the fragmentary top view and sectional drawing which show the water droplet removal groove | channel in the separator which concerns on this invention. It is a fragmentary top view which shows a part of cooling water flow path in the separator which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Multiple uneven plate, 2 ... Flat plate part, 3 ... Convex part, 20 ... Flat plate body, 21 ... Groove, 22 ... Mountain line, 23 ... Valley line, 24 ... Convex part, 25 ... Multiple uneven plate, 26 ... Projection, 50 ... Electrolyte membrane, 51, 52 ... Electrode, 53 ... Separator, 54 ... Gas flow path, 57 ... Cooling water flow path, 58 ... Coining groove, 59 ... Wave bending groove, 60 ... Sink groove, 67 ... Inlet manifold, 69 ... Water drop removal groove.

Claims (6)

In the separator for a fuel cell using a multiple uneven plate in which a plurality of independent uneven portions are formed on the front and back surfaces of the plate material,
A plurality of first groove portions formed by reducing the plate thickness on at least one surface of a plate material that is a material, and a bent shape that is continuous in a wave shape in which valley lines and mountain lines intersect the first groove portions. A separator for a fuel cell using a multiple uneven plate, wherein the plate member is bent so that the second groove portion is formed on both the front and back surfaces of the plate member.   The groove part formed in said one surface forms the flow path for cooling water, and the groove part formed in the other surface forms the flow path for gas. A separator for fuel cells using multiple uneven plates.   3. The multiple unevenness according to claim 2, wherein the shape or arrangement of the first groove portion on the upstream side in the flow direction of the cooling water is different from the shape or arrangement of the first groove portion on the downstream side. A separator for fuel cells using a plate. A third groove portion formed so as to intersect the mountain line in a portion corresponding to the mountain line of the other surface of the plate member with the bending process,
The first groove and the second groove on the one surface form a cooling water channel, and the second groove and the third groove on the other surface form a gas channel. A fuel cell separator using the multiple uneven plate according to claim 1.   The fourth portion having a cross-sectional area larger than that of the third groove portion is formed by pressing and deforming a predetermined portion of the portion corresponding to the mountain line on the other surface of the plate material in the plate thickness direction. Item 10. A fuel cell separator using the multiple uneven plate according to Item 1.   The multiple uneven plate according to claim 1, wherein a plurality of grooves are formed on only one surface by forming a plurality of grooves thinner than other portions by bending a mountain valley in a direction intersecting the grooves. A multi-concave plate bending mold for obtaining a multi-concave plate, comprising a protrusion for restricting deformation of the groove.

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