SCREEN COATING JIG AND SEALING STRUCTURE OF PLATE-SHAPED MEMBER

Screen coating jig for screen-coating surface of plate-shaped member having protrusion to cross protrusion with sealing member, including: jig body having higher rigidity than sealing member to be placed on surface of plate-shaped member. Jig body includes: first surface facing surface of plate-shaped member; second surface on opposite side of first surface; and pair of dividing surfaces extending from first surface to second surface and dividing at least part of jig body into first portion and second portion. First surface includes recess to be fitted to protrusion of plate-shaped member starting from intersection portions with pair of dividing surfaces. Pair of dividing surfaces has uniform height from first surface to second surface. Width between pair of dividing surfaces is narrowed at position corresponding to recess.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2023-057478 filed on Mar. 31, 2023, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a screen coating jig for screen-coating a plate-shaped member with a sealing member, and a sealing structure of the plate-shaped member.

Description of the Related Art

In the related art, there has been known a jig for screen-coating, with a paste-like member, a plate material provided in an uneven shape such as a separator of a fuel cell. For example, in a jig described in JP 2017-087504 A, fitting recesses and protrusions that can be fitted into recesses and protrusions formed in an application target member are formed on a surface facing the application target member in a mask integrally provided on a screen, and a paste application opening is opened in at least one of the fitting protrusion and the fitting recess in the fitting recesses and protrusions.

Meanwhile, when a sealed space is formed facing a plate material provided in an uneven shape, a sealing member crossing a surface of the plate material may be formed. In such a case, it is preferable to make a height of the sealing member uniform in order to secure sealing properties. However, J P 2017-087504 A does not describe this point at all.

SUMMARY OF THE INVENTION

An aspect of the present invention is a screen coating jig for screen-coating a surface of a plate-shaped member having a protrusion to cross the protrusion with a sealing member, including: a jig body having higher rigidity than the sealing member to be placed on the surface of the plate-shaped member. The jig body includes: a first surface facing the surface of the plate-shaped member; a second surface on an opposite side of the first surface; and a pair of dividing surfaces extending from the first surface to the second surface and dividing at least a part of the jig body into a first portion and a second portion. The first surface includes a recess to be fitted to the protrusion of the plate-shaped member starting from intersection portions with the pair of dividing surfaces. The pair of dividing surfaces has a uniform height from the first surface to the second surface. A width between the pair of dividing surfaces is narrowed at a position corresponding to the recess.

Another aspect of the present invention is a sealing structure of a plate-shaped member, including: a plate-shaped member having a protrusion; and a sealing member provided on a surface of the plate-shaped member to cross the protrusion. The sealing member has a uniform height from the surface of the plate-shaped member. A width of the sealing member is narrowed at a position where the sealing member crosses the protrusion.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference toFIGS.1to15. A screen coating jig according to the embodiments of the present invention is a jig for screen-coating, with a sealing member, a surface of a plate-shaped member having a protrusion to cross the protrusion, and is, for example, a jig for screen-coating, with a sealing member, a separator of a fuel cell provided in an uneven shape. A sealing structure of a plate-shaped member according to the embodiments of the present invention is a sealing structure provided on a surface of the plate-shaped member having a protrusion to cross the protrusion, and is, for example, a sealing structure provided on a surface of a separator of a fuel cell provided in an uneven shape. The fuel cell is mounted on, for example, a vehicle and can generate electric power for driving the vehicle. First, an overall configuration of a fuel cell stack that is a component of the fuel cell will be schematically described.

FIG.1is a perspective view schematically illustrating an overall configuration of a fuel cell stack100having a sealing structure of a plate-shaped member according to the embodiments of the present invention. Hereinafter, for the sake of convenience, three-axis directions orthogonal to each other as illustrated in the drawing are defined as a front-rear direction, a left-right direction, and an up-down direction, and a configuration of each unit will be described according to such definitions. These directions are not necessarily identical to a front-rear direction, a left-right direction, and an up-down direction of the vehicle. For example, the front-rear direction inFIG.1may be the front-rear direction, the left-right direction, or the up-down direction of the vehicle.

As illustrated inFIG.1, the fuel cell stack100includes a cell stacked body101formed by stacking a plurality of power generation cells1in the front-rear direction, and end units102arranged at both front and rear end portions of the cell stacked body101, and has a substantially rectangular parallelepiped shape as a whole. A length of the cell stacked body101in the left-right direction is longer than a length in the up-down direction. InFIG.1, a single power generation cell1is illustrated for the sake of convenience. The power generation cell1includes an electrode assembly2having a joint body including an electrolyte membrane and an electrode, and separators3and3that are arranged on both front and rear sides of the electrode assembly2and sandwich the electrode assembly2. The electrode assembly2and the separators3are alternately arranged in the front-rear direction.

The separator3includes a pair of front and rear metal thin plates having a corrugated cross section, and is integrally formed by joining outer peripheries of the thin plates. For the separator3, a conductive material having excellent corrosion resistance is used, and for example, titanium, a titanium alloy, stainless steel, or the like can be used. A cooling flow path through which a cooling medium flows is formed inside the separator3, and a power generation surface of the power generation cell1is cooled by the flow of the cooling medium. For example, water can be used as the cooling medium. Surfaces (front surface and rear surface) of the separators3facing the electrode assembly2are formed in an uneven shape by press-molding or the like to form gas flow paths between the separators and the electrode assembly2.

The separator3on the front side of the electrode assembly2is, for example, a separator on an anode side (anode separator), and an anode flow path through which a fuel gas flows is formed between the anode separator3and the joint body of the electrode assembly2. The separator3on the rear side of the electrode assembly2is, for example, a separator on a cathode side (cathode separator), and a cathode flow path through which an oxidant gas flows is formed between the cathode separator3and the joint body of the electrode assembly2. For example, a hydrogen gas can be used as the fuel gas, and for example, air can be used as the oxidant gas. The fuel gas and the oxidant gas may be referred to as a reaction gas without being distinguished from each other.

FIG.2is a perspective view illustrating a schematic configuration of the electrode assembly2. As illustrated inFIG.2, the electrode assembly2includes a substantially rectangular joint body20and a frame21that supports the joint body20. The joint body20is a membrane electrode joint body (so-called membrane electrode assembly (MEA)), and has an electrolyte membrane, an anode electrode provided on a front surface of the electrolyte membrane, and a cathode electrode provided on a rear surface of the electrolyte membrane.

The electrolyte membrane is, for example, a solid polymer electrolyte membrane, and a thin film of perfluorosulfonic acid containing moisture can be used. Not only a fluorine-based electrolyte but also a hydrocarbon-based electrolyte can be used.

The anode electrode is an electrode catalyst layer that is formed on the front surface of the electrolyte membrane and serves as a reaction field of an electrode reaction, and a gas diffusion layer that diffuses and supplies a reaction gas is provided on the front surface of the electrode catalyst layer. The cathode electrode is an electrode catalyst layer that is formed on the rear surface of the electrolyte membrane and serves as a reaction field of an electrode reaction, and a gas diffusion layer that diffuses and supplies a reaction gas is provided on the rear surface of the electrode catalyst layer. The electrode catalyst layer includes a catalytic metal that promotes an electrochemical reaction between hydrogen contained in the fuel gas and oxygen contained in the oxidant gas, an electrolyte having proton conductivity, carbon particles having electron conductivity, and the like. The gas diffusion layer is made of a conductive member having gas permeability, for example, a carbon porous body.

In the anode electrode, the fuel gas (hydrogen) supplied through the anode flow path and the gas diffusion layer is ionized by an action of a catalyst, passes through the electrolyte membrane, and moves to the cathode electrode side. Electrons generated at this time pass through an external circuit and are extracted as electric energy. In the cathode electrode, an oxidant gas (oxygen) supplied via the cathode flow path and the gas diffusion layer reacts with hydrogen ions guided from the anode electrode and electrons moved from the anode electrode to generate water. The generated water gives an appropriate humidity to the electrolyte membrane, and excess water is discharged to the outside of the electrode assembly2.

The frame21is a thin plate having a substantially rectangular shape, and is made of an insulating resin, rubber, or the like. A substantially rectangular opening portion21ais provided in a central portion of the frame21, and the joint body20is provided to cover the entire opening portion21a. Three through-holes211to213penetrating the frame21in the front-rear direction are opened in a line in the up-down direction on a left side of the opening portion21aof the frame21, and three through-holes214to216penetrating the frame21in the front-rear direction are opened in a line in the up-down direction on a right side of the opening portion21a.

As illustrated inFIG.1, through-holes311to316penetrating the separators3in the front-rear direction are opened in the separators3on the front and rear sides of the electrode assembly2at positions corresponding to the through-holes211to216of the frame21. The through-holes311to316communicate with the through-holes211to216of the frame21, respectively. The sets of the through-holes211to216and311to316communicating with each other form flow paths PA1to PA6(indicated by arrows for the sake of convenience) penetrating the cell stacked body101and extending in the front-rear direction. The flow paths PA1to PA6may be referred to as manifolds. The flow paths PA1to PA6are connected to a manifold outside the fuel cell stack100.

The flow path PA1(solid arrow) extending forward via the through-holes211and311is a fuel gas supply flow path. The flow path PA6(solid arrow) extending rearward via the through-holes216and316is a fuel gas discharge flow path. The fuel gas supply flow path PA1and the fuel gas discharge flow path PA6communicate with the anode flow path facing the front surface of the joint body20, and as indicated by the solid arrows, the fuel gas flows through the anode flow path in the left-right direction via the fuel gas supply flow path PA1and the fuel gas discharge flow path PA6. The communication between the anode flow path and the other flow paths PA2to PA5is blocked via a sealing member7(FIG.3). The fuel gas flowing through the fuel gas discharge flow path PA6is a fuel gas a part of which has been used in the anode electrode, and may be referred to as a fuel exhaust gas.

The flow path PA4(dotted arrow) extending forward via the through-holes214and314is an oxidant gas supply flow path. The flow path PA3(dotted arrow) extending rearward via the through-holes213and313is an oxidant gas discharge flow path. The oxidant gas supply flow path PA4and the oxidant gas discharge flow path PA3communicate with the cathode flow path facing the rear surface of the joint body20, and as indicated by the dotted arrows, the oxidant gas flows through the cathode flow path in the left-right direction via the oxidant gas supply flow path PA4and the oxidant gas discharge flow path PA3. The communication between the cathode flow path and the other flow paths PA1, PA2, PA5, and PA6is blocked via the sealing member7(FIG.3). The oxidant gas flowing through the oxidant gas discharge flow path PA3is an oxidant gas a part of which has been used in the cathode electrode, and may be referred to as oxidant exhaust gas. The fuel exhaust gas and the oxidant exhaust gas may be referred to as a reaction exhaust gas without being distinguished from each other.

The flow path PA5(dashed-dotted line arrow) extending forward via the through-holes215and315is a cooling medium supply flow path. The flow path PA2(dashed-dotted line arrow) extending rearward via the through-holes212and312is a cooling medium discharge flow path. The cooling medium supply flow path PA5and the cooling medium discharge flow path PA2communicate with the cooling flow path inside the separator3, and the cooling medium flows through the cooling flow path via the cooling medium supply flow path PA5and the cooling medium discharge flow path PA2. The communication between the cooling flow path and the other flow paths PA1, PA3, PA4, and PA6is blocked via the sealing member7(FIG.3).

Each of the end units102arranged on both the front and rear sides of the cell stacked body101includes a terminal plate4, an insulating plate5, and an end plate6. Note that the end unit102on the front side may be referred to as a dry-side end unit, and the end unit102on the rear side may be referred to as a wet-side end unit. The pair of front and rear terminal plates4and4is arranged on both front and rear sides of the cell stacked body101with the cell stacked body interposed therebetween. The pair of front and rear insulating plates5and5is arranged on both front and rear sides of the terminal plates4and4with the terminal plates interposed therebetween. The pair of front and rear end plates6and6is arranged on both front and rear sides of the insulating plates5and5with the insulating plates interposed therebetween.

The terminal plate4is a substantially rectangular plate-shaped member made of metal, and has a terminal portion for extracting electric power generated by an electrochemical reaction in the cell stacked body101. The insulating plate5is a substantially rectangular plate-shaped member made of non-conductive resin or rubber, and electrically insulates the terminal plate4from the end plate6. The end plate6is a plate-shaped member made of metal or resin having high strength, and for example, a coupling member elongated in the front-rear direction and coupling the front and rear end plates6and6to each other is fixed to the end plate6with a bolt. The fuel cell stack100is held in a state of being pressed in the front-rear direction by the end plates6and6via the coupling member. A case surrounding the cell stacked body101may be used as the coupling member, and the end plates6and6may be fixed to a front end surface and a rear end surface of the case, respectively.

A plurality of through-holes102ato102fpenetrating the end unit102in the front-rear direction are opened in the end unit102on the rear side. Note that each of the through-holes102ato102fincludes a through-hole penetrating the terminal plate4, a through-hole penetrating the insulating plate5, and a through-hole penetrating the end plate6, but, inFIG.1, these through-holes are collectively referred to as through-holes102ato102ffor the sake of convenience. The through-hole102ais opened on an extension line of the fuel gas supply flow path PA1to communicate with the fuel gas supply flow path PA1. The through-hole102bis opened on an extension line of the cooling medium discharge flow path PA2to communicate with the cooling medium discharge flow path PA2. The through-hole102cis opened on an extension line of the oxidant gas discharge flow path PA3to communicate with the oxidant gas discharge flow path PA3. The through-hole102dis opened on an extension line of the oxidant gas supply flow path PA4to communicate with the oxidant gas supply flow path PA4. The through-hole102eis opened on an extension line of the cooling medium supply flow path PA5to communicate with the cooling medium supply flow path PA5. The through-hole102fis opened on an extension line of the fuel gas discharge flow path PA6to communicate with the fuel gas discharge flow path PA6.

More specifically, a fuel gas tank storing a high-pressure fuel gas is connected to the through-hole102avia an ejector, an injector, or the like, and the fuel gas in the fuel gas tank is supplied to the fuel cell stack100via the through-hole102a. A gas-liquid separator is connected to the through-hole102f, and a fuel gas (fuel exhaust gas) discharged via the through-hole102fis separated into a fuel gas and water by the gas-liquid separator. The separated fuel gas is sucked via the ejector and is supplied to the fuel cell stack100again. The separated water is discharged to the outside via a drain flow path.

A compressor for supplying the oxidant gas is connected to the through-hole102d, and the oxidant gas compressed by the compressor is supplied to the fuel cell stack100via the through-hole102d. The oxidant gas (oxidant exhaust gas) flows to the outside from the through-hole102c. A pump for supplying the cooling medium is connected to the through-hole102e, and the cooling medium is supplied to the fuel cell stack100via the through-hole102e. The cooling medium is discharged from the through-hole102b. The discharged cooling medium is cooled by heat exchange in a radiator, and is supplied to the fuel cell stack100again via the through-hole102e.

A schematic configuration of the fuel cell stack100has been described above. The fuel cell stack100is housed in a substantially box-shaped case and is mounted on the vehicle.

FIG.3is a cross-sectional view of the power generation cell1ofFIG.1taken along line III-III. As illustrated inFIG.3, an anode flow path An is formed between the anode separator3on the front side and the electrode assembly2(joint body20), and a cathode flow path Ca is formed between the cathode separator3on the rear side and the electrode assembly2(joint body20).FIG.4is a front view illustrating an example of the sealing structure in the vicinity of the through-hole311(fuel gas supply flow path PA1) of the separator (anode separator)3, and illustrates a surface (rear surface) in the vicinity of the through-hole311of the separator3facing the electrode assembly2(frame21).

As illustrated inFIGS.3and4, a plurality of protrusions30having a semi-cylindrical shape (only one protrusion is illustrated in the drawing) forming a communication path that allows communication between the through-holes311and314(reaction gas supply flow paths PA1and PA4) and the gas flow paths An and Ca are provided on the surface of the separator3facing the electrode assembly2. Among these communication paths, a communication path that allows communication between the fuel gas supply flow path PA1and the cathode flow path Ca and a communication path that allows communication between the oxidant gas supply flow path PA4and the anode flow path An are closed.

The sealing member7is provided on the surface of the separator3to cross the protrusions30and surround the through-holes311and314. As the sealing member7, a resin material such as a thermosetting elastomer such as silicon, urethane, or fluorine, a thermoplastic elastomer, synthetic rubber, or natural rubber can be used. A distal end of the sealing member7provided on the surface of the separator3is in close contact with the electrode assembly2(frame21), whereby the reaction gas supply flow paths PA1and PA4are blocked (sealed) from an external space EX and the gas flow paths Ca and An not communicating with the reaction gas supply flow paths.

More specifically, when the fuel cell stack100inFIG.1is pressed in the front-rear direction by the end plates6and6via the coupling member, a compressive load in the front-rear direction is applied to the sealing member7, the sealing member7is pressed to be elastically deformed, and the distal end of the sealing member7is brought into close contact with the electrode assembly2(frame21). At this time, the surface pressure is applied to the distal end of the sealing member7by the compressive load, whereby the sealed state of the reaction gas supply flow paths PA1and PA4is secured.

As described above, in a case where the sealed space is formed to face the plate-shaped member such as the separator3having the protrusion30, it is preferable to make the height of the sealing member7uniform in order to secure the sealing properties. Therefore, in the present embodiment, a screen coating jig is configured as follows such that it is possible to screen-coat the surface of the separator3having the protrusion30with the sealing member7crossing the protrusion30and having a uniform height.

First Embodiment

FIG.5is a front view illustrating an example of a screen coating jig (hereinafter, jig)10A according to a first embodiment of the present invention, andFIG.6is a cross-sectional view taken along line VI-VI ofFIG.5. As illustrated inFIGS.5and6, the jig10A includes a jig body11placed on the surface of the separator3to be a coating surface, and a connection portion12that connects a first portion111and a second portion112of the jig body11.

The jig body11and the connection portion12are made of a member having higher rigidity than that of the sealing member7. For example, metal such as stainless steel can be used for the jig body11and the connection portion12. A material obtained by applying a water-repellent treatment to a resin such as Teflon (registered trademark) or silicon may be used for the jig body11and the connection portion12. The width of the connection portion12is set to a sufficiently small value (for example, about 100 μm) in consideration of the material of the sealing member7so as not to cause a step on the surface of the sealing member7after coating.

The jig body11has a first surface11afacing the surface of the separator3, a second surface11bon a side opposite to the first surface11a, and a pair of dividing surfaces113and113that extends from the first surface11ato the second surface11band divides the jig body11into the first portion111and the second portion112. In the example ofFIG.5, the pair of dividing surfaces113and113is provided in an annular shape, and completely divides the jig body11into the first portion111on the inner side surrounded by the pair of dividing surfaces113and113and the second portion112on the outer side. The pair of dividing surfaces113and113may be provided in a line segment shape or a curved line shape to partially divide the jig body11into the first portion111and the second portion112. In this case, the jig10A may be configured only with the jig body11without providing the connection portion12connecting the first portion111and the second portion112. Hereinafter, a space between the first portion111and the second portion112, in other words, a space between the first surface11aand the second surface11band between the pair of dividing surfaces113and113is referred to as a groove portion13.

The jig body11is formed, for example, by molding a lower layer14including the first surface11aand an upper layer15including the second surface11bseparately and joining the lower layer14and the upper layer15. In this case, the lower layer14includes the first portion111and the second portion112, and the upper layer15includes the first portion111, the second portion112, and the connection portion12. The jig body11and the connection portion12may be integrally molded, and subjected to processing such as etching processing or milling processing so that the jig body11is divided into the first portion111and the second portion112and the connection portion12is formed.

FIG.7is a perspective view partially illustrating the jig10A, and schematically illustrates a state in which the surface of the separator3having the protrusion30to cross the protrusion30is screen-coated with the sealing member7by the jig10A. As illustrated inFIG.7, in the screen coating, first, the jig10A is placed on the surface of the separator3to be the coating surface such that the first surface11aof the jig body11faces the surface of the separator3having the protrusion30. Next, a paste P of a resin material such as a thermosetting elastomer such as silicon, urethane, or fluorine having thixotropy, a thermoplastic elastomer, synthetic rubber, or natural rubber is placed on the second surface11bof the jig body11. Then, the paste P is pressed against the second surface11baround the groove portion13by a squeegee16, the squeegee16is slid to apply the paste P on the surface of the separator3via the groove portion13, and the paste P is cured, thereby applying and forming the sealing member7on the surface of the separator3. Such screen coating may be performed manually, or may be automatically performed using a screen printing apparatus including a mounting table where the separator3is fixed, the jig10A, and the squeegee16.

The first surface11aof the jig body11has a pair of recesses115and115fitted to the protrusions30of the separator3starting from intersection portions114and114with the pair of dividing surfaces113and113. One of the pair of recesses115and115is provided in the first portion111of the jig body11, and the other is provided in the second portion112of the jig body11. In a case where the jig body11is made of metal, a material obtained by applying a water-repellent treatment to a resin such as Teflon (registered trademark) or silicon may be used only for the recess115.

Since the recess115fitted to the protrusion30on the surface of the separator3is provided in the first surface11aof the jig body11facing the coating surface, it is possible to regulate the displacement of the jig body11with respect to the coating surface even in a case where a pressing force is applied to the jig10A in the sliding direction of the squeegee16during the coating. Thus, screen coating can be accurately performed on the surface of the separator3.

As described above, by performing the screen coating using the jig body11having relatively higher rigidity than that of the sealing member7and the squeegee16, it is possible to prevent the sealing member7from being applied to the outside of the groove portion13and to coat and form the sealing member7having a shape conforming to the shape of the groove portion13.

The jig body11is formed such that the depth of the groove portion13, that is, a height h1of the pair of dividing surfaces113and113is uniform from the first surface11ato the second surface11b. Therefore, the height of the sealing member7applied and formed along the shape of the groove portion13defined by the pair of dividing surfaces113and113, the first surface11a(surface of the separator3), and the second surface11b(squeegee16) of the jig body11can be made substantially uniform.

FIG.8is a cross-sectional view of the sealing member7coated on the surface of the separator3, andFIG.9is a diagram for describing characteristics (thixotropic characteristics) of the resin material constituting the sealing member7. As illustrated inFIGS.8and9, in a case where coating conditions such as the composition of the paste P are the same, a thickness d of the sealing member7made of a resin material having thixotropy after curing is determined according to a width w of the portion in contact with the surface of the separator3. That is, as the width w of the sealing member7is larger (wider), the thickness d of the sealing member7is larger (higher), and as the width w of the sealing member7is smaller (narrower), the thickness d of the sealing member7is smaller (lower). The width w of the sealing member7corresponds to the width w of the groove portion13of the jig10A, that is, the width w between the pair of dividing surfaces113and113of the jig body11.

FIG.10is a cross-sectional view of the sealing member7coated by the jig10A, andFIG.11is a perspective view of the sealing member7coated by the jig10A. As illustrated inFIGS.10and11, the width w and the thickness d of the sealing member7coated by the jig10A are uniform in the extension direction of the sealing member7. Since the sealing member7extends along the surface of the separator3including the protrusion30, a height h2of the sealing member7from the surface of the separator3is higher at a position where the sealing member7crosses the protrusion30than the other positions by the height of the protrusion30.

As described above, in a case where the height h2of the sealing member7from the surface of the separator3varies, the linear pressure (seal load) applied to the distal end of the sealing member7in close contact with the electrode assembly2(frame21) inFIG.3varies in the extension direction of the sealing member7inFIG.4, and leakage may occur at a place where the linear pressure is low. Note that the linear pressure is an average value per unit length of the surface pressure applied to the distal end of the sealing member7in close contact with the electrode assembly2(frame21), in the extension direction of the sealing member7by the compressive load.

Second Embodiment

FIG.12is a perspective view partially illustrating a jig10B according to a second embodiment of the present invention,FIG.13is a cross-sectional view of the sealing member7coated by the jig10B, andFIG.14is a perspective view of the sealing member7coated by the jig10B. To describe the difference from the first embodiment, the jig10B is configured such that the width w (the width w of the groove portion13) between the pair of dividing surfaces113and113of the jig body11is narrowed at a position corresponding to the recess115. More specifically, as illustrated inFIG.12, a width w1of the groove portion13at the position corresponding to the recess115is set to a value smaller than a width w2of the groove portion13at the other positions (w1<w2).

In this case, as illustrated inFIGS.13and14, the height h2of the sealing member7coated by the jig10B from the surface of the separator3is uniform in the extension direction of the sealing member7. That is, the width w1of the sealing member7at the position where the sealing member7crosses the protrusion30is smaller than the width w2of the sealing member7at the other positions, and the thickness d of the sealing member7is smaller at the position where the sealing member7crosses the protrusion30than at the other positions. Thus, the height h2of the sealing member7from the surface of the separator3becomes uniform in the extension direction of the sealing member7, and the variation in the linear pressure (seal load) applied to the distal end of the sealing member7in close contact with the electrode assembly2(frame21) ofFIG.3is eliminated, and the sealing properties is improved.

The widths w1and w2of the sealing member7and the groove portion13of the jig10B are set according to the maximum pressure of the gas flowing through the gas flow path, the material of the sealing member7, the compressive load applied to the sealing member7, and the like. The ratio between the width w1and the width w2may be determined on the basis of the coating position of the sealing member7on the surface of the separator3, the shape of the protrusion30, the characteristics of the resin material illustrated inFIG.9, and the like, or may be determined by trial production of the jig10B (jig body11) and the sealing member7.

FIG.15is a front view illustrating an example of the sealing structure of the plate-shaped member according to the second embodiment, and illustrates the sealing structure in the vicinity of the through-hole311(fuel gas supply flow path PA1) of the separator (anode separator)3facing the electrode assembly2(frame21). As illustrated inFIG.15, the sealing structure of the plate-shaped member includes the separator3having the protrusion30, and the sealing member7provided on the surface of the separator3to cross the protrusion30. The height h2of the sealing member7from the surface of the separator3is uniform, and the width w (w1, w2) of the sealing member7is narrowed at a position where the sealing member7crosses the protrusion30.

As described above, in the second embodiment, unlike the first embodiment, the jig10B is configured such that the width w (the width w of the groove portion13) between the pair of dividing surfaces113and113of the jig body11is narrowed at the position corresponding to the recess115, and thus the sealing member7having a uniform height can be formed. In addition, since the height h1of the groove portion13of the jig10B is uniform, the sealing member7along the shape of the groove portion13can be formed by single screen coating using the squeegee16as in the first embodiment.

According to the present embodiment, the following effects can be achieved.(1) The jig10B for screen-coating, with the sealing member7, the surface of the separator3having the protrusion30to cross the protrusion30includes the jig body11(FIG.12). The jig body11has higher rigidity than that of the sealing member7. The jig body11is to be placed on the surface of the separator3. The jig body11has the first surface11afacing the surface of the separator3, the second surface11bon a side opposite to the first surface11a, and the pair of dividing surfaces113and113that extends from the first surface11ato the second surface11band divides at least a part of the jig body11into the first portion111and the second portion112. The first surface11ahas the recesses115and115to be fitted to the protrusions30of the separator3starting from intersection portions114and114with the pair of dividing surfaces113and113. The pair of dividing surfaces113and113has a uniform height h1from the first surface11ato the second surface11b, and the width w between the pair of dividing surfaces113and113is narrowed at the position corresponding to the recesses115and115.

As described above, by providing the recess115fitted to the protrusion30on the surface of the separator3, displacement of the jig body11with respect to the coating surface can be restricted during the coating, and screen coating can be accurately performed on the surface of the separator3. In addition, by performing the screen coating using the jig body11having relatively higher rigidity than that of the sealing member7, it is possible to prevent the sealing member7from being applied to the outside of the groove portion13and to coat and form the sealing member7having a shape conforming to the shape of the groove portion13. Further, by making the depth (height) h1of the groove portion13uniform, the sealing member7can be formed by single screen coating using the squeegee16. Furthermore, by narrowing the width w of the groove portion13at the position corresponding to the recess115fitted to the protrusion30on the surface of the separator3, it is possible to prevent the sealing member7from swelling at the position where the sealing member7crosses the protrusion30and to form the sealing member7having a uniform height h2.(2) The protrusion30has a curved cross-sectional shape, for example, a semi-cylindrical shape (FIG.12). Even in a case where the protrusion30is curved and the sealing member7coated on the protrusion30is likely to spread, by narrowing the widths w of the groove portion13and the sealing member7at the position where the sealing member7crosses the protrusion30, it is possible to prevent swelling at the position where the sealing member7crosses the protrusion30and to form the sealing member7having a uniform height h2.(3) The pair of dividing surfaces113and113surrounds one of the first portion111and the second portion112(FIG.12). The jig10B further includes the connection portion12that connects the first portion111and the second portion112. Even in a case where the pair of dividing surfaces113and113(groove portion13) is provided in an annular shape and the jig body11is completely divided, the screen coating can be accurately performed by providing the connection portion12.(4) The sealing member7is a resin member. Even in a case where the sealing member7is coated through the groove portion13of the jig10, the aspect ratio between the width w and the thickness d after curing is determined by the thixotropy of the resin material. In consideration of such characteristics, the height h2of the cured sealing member7from the surface of the separator3can be made uniform by narrowing the width w at the position where the sealing member7crosses the protrusion30of which the thickness d should be reduced.(5) The sealing structure of the plate-shaped member includes the separator3having the protrusion30, and the sealing member7provided on the surface of the separator3to cross the protrusion30(FIGS.13to15). The height h2of the sealing member7from the surface of the separator3is uniform, and the width w of the sealing member7is narrowed at a position where the sealing member7crosses the protrusion30. In a case where the sealing member7is used to form the sealed space to face the plate-shaped member such as the separator3having the protrusion30, the sealing properties of the sealed space can be secured by making the height h2of the sealing member7uniform.

In the above embodiments, the screen coating jig for screen-coating the surface of the separator3of the fuel cell with the sealing member7to cross the protrusion30forming the gas communication path and the sealing structure of the separator3have been described as an example, but the screen coating jig and the sealing structure of the plate-shaped member are not limited thereto. The protrusion may be any protrusion as long as the protrusion protrudes from the surface of the plate-shaped member on which the sealing member is applied, and is not limited to a hollow protrusion that forms a communication path for gas or the like. The sealing member may cross the protrusion, and the extension direction of the protrusion and the extension direction of the sealing member do not need to be orthogonal to each other. The surface of the plate-shaped member only needs to have the protrusion and a portion other than the protrusion, and the area occupied by the protrusion is not required to be smaller than the area occupied by the portion other than the protrusion. For example, the present invention can also be applied to a plate-shaped member having a recess such as a groove in a part by regarding the portion other than the recess as the protrusion. In this case, it is possible to form the sealing member having a uniform height by configuring the width of the sealing member to be wide at a position where the sealing member crosses the recess of such a plate-shaped member and configuring the width between the pair of dividing surfaces of the jig body to be wide at a position corresponding to the protrusion fitted to the recess of such a plate-shaped member.

The above embodiment can be combined as desired with one or more of the aforesaid modifications. The modifications can also be combined with one another.

According to the present invention, it becomes possible to form a uniform height sealing member.