Screen coating tool and sealing structure for plate-shaped member

Abstract

To form a seal member having a uniform height.SOLUTION: There is provided a screen coating jig 10B which coats by screen coating, a seal member so as to traverse a salient 30, on a surface of a plate member 3 having the salient 30. The screen coating jig comprises: a jig main body 11 which is formed of a member whose rigidity is greater than that of the seal member, and is mounted on a surface of the plate member 3. The jig main body 11 has; a first surface 11a facing the surface of the plate member 3; a second surface 11b on an opposite side of the first surface 11a; and a pair of division surfaces 113 which extends from the first surface 11a to the second surface 11b and divides at least a part of the jig main body 11 into a first part 111 and a second part 112. The first surface 11a has a recess 115 which fits to the salient 30 of the plate member 3, with a cross point 114 with the division surface 113, as an origin. The division surface 113 has a uniform height from the first surface 11a to the second surface 11b, and a width between the pair of division surfaces 113 becomes narrow at a position corresponding to the recess 115.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to a screen coating tool for screen coating a seal material onto a plate-like member, and a seal structure for the plate-like member. [Background technology]

[0002] Conventionally, there has been known a jig for screen coating a paste-like material onto a plate material having an uneven surface, such as a separator for a fuel cell (see, for example, Patent Document 1). In the jig described in Patent Document 1, a mask is provided integrally with the screen, and on its surface facing the mating member is formed with mating unevenness that can be fitted into the unevenness formed on the mating member, and an opening for applying the paste is provided in at least one of the mating convex portion and mating concave portion of the mating unevenness. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-87504 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when forming a sealed space facing a plate material having an uneven surface, a sealing member may be formed across the surface of the plate material, and in such a case, it is preferable to make the height of the sealing member uniform in order to ensure sealing performance. However, the above-mentioned Patent Document 1 does not mention anything about this point. [Means for solving the problem]

[0005] One aspect of the present invention is a screen coating jig for screen coating a sealing material on a surface of a plate-like member having a convex portion so as to cross the convex portion. The screen coating jig includes a jig body made of a member having a higher rigidity than the sealing material and placed on the surface of the plate-like member. The jig body has a first surface facing the surface of the plate-like member, a second surface opposite to 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 has a recess that fits into the convex portion of the plate-like member, starting from an intersection with the pair of dividing surfaces. The pair of dividing surfaces have a uniform height from the first surface to the second surface, and the width between the pair of dividing surfaces narrows at a position corresponding to the recess.

[0006] A sealing structure for a plate-like member according to another aspect of the present invention includes a plate-like member having a convex portion, and a sealing member provided on a surface of the plate-like member so as to cross the convex portion. The sealing member has a uniform height from the surface of the plate-like member, and the width of the sealing member narrows at a position where it crosses the convex portion. Effect of the Invention

[0007] According to the present invention, a seal member of uniform height can be formed. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a schematic overall configuration of a fuel cell stack having a seal structure for plate members according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view showing a schematic configuration of an electrode assembly included in the fuel cell stack of FIG. [Diagram 3] FIG. 3 is a cross-sectional view of the power generating cell shown in FIG. 1 along line III-III. [Figure 4] 4 is a front view showing an example of a seal structure near the through-hole of the separator in FIG. 3. [Diagram 5] FIG. 1 is a front view showing an example of a screen coating tool according to a first embodiment of the present invention. [Figure 6] Cross-sectional view taken along line VI-VI in Figure 5 . [Figure 7]FIG. 6 is a perspective view partially showing the screen coating jig of FIG. 5. [Figure 8] FIG. 5 is a cross-sectional view of the seal member of FIG. 4 . [Figure 9] 5 is a diagram for explaining the characteristics of a resin material constituting the seal member in FIG. 4. [Figure 10] 6 is a cross-sectional view of a sealing member coated by the screen coating tool of FIG. 5 . [Figure 11] FIG. 6 is a perspective view of a seal member coated by the screen coating tool of FIG. 5 . [Figure 12] FIG. 5 is a perspective view partially showing a screen coating tool according to a second embodiment of the present invention. [Figure 13] 13 is a cross-sectional view of a seal member coated by the screen coating tool of FIG. 12. [Figure 14] FIG. 13 is a perspective view of a seal member coated by the screen coating tool of FIG. 12 . [Figure 15] FIG. 6 is a front view showing an example of a seal structure for a plate-like member according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 15. The screen coating jig according to the embodiment of the present invention is a jig for screen coating a seal member on the surface of a plate-like member having a convex portion so as to cross the convex portion, for example, a jig for screen coating a seal member on a separator of a fuel cell provided in an uneven shape. In addition, the seal structure of the plate-like member according to the embodiment of the present invention is a seal structure provided on the surface of a plate-like member having a convex portion so as to cross the convex portion, for example, a seal structure provided on the surface of a separator of a fuel cell provided in an uneven shape. The fuel cell is mounted, for example, on a vehicle and can generate electric power for driving the vehicle. First, the overall configuration of a fuel cell stack, which is a component of a fuel cell, will be described in brief.

[0010] FIG. 1 is a perspective view showing a schematic overall configuration of a fuel cell stack 100 having a sealing structure of a plate-shaped member according to an embodiment of the present invention. In the following, for convenience, three mutually orthogonal axial directions as shown in the figure are defined as the front-rear direction, the left-right direction, and the up-down direction, and the configuration of each part will be described according to these definitions. These directions are not necessarily the same as the front-rear direction, the left-right direction, and the up-down direction of a vehicle. For example, the front-rear direction in FIG. 1 may be the front-rear direction, the left-right direction, or the up-down direction of a vehicle.

[0011] As shown in FIG. 1, a fuel cell stack 100 has a cell stack 101 formed by stacking a plurality of power generating cells 1 in the front-rear direction, and end units 102 arranged at both front and rear ends of the cell stack 101, and has a generally rectangular parallelepiped shape as a whole. The length of the cell stack 101 in the left-right direction is longer than its length in the up-down direction. For convenience, FIG. 1 shows a single power generating cell 1. The power generating cell 1 has an electrode assembly 2 having an assembly including an electrolyte membrane and an electrode, and separators 3, 3 arranged on both the front and rear sides of the electrode assembly 2 and sandwiching the electrode assembly 2 therebetween. The electrode assemblies 2 and the separators 3 are arranged alternately in the front-rear direction.

[0012] The separator 3 has a pair of front and rear thin metal plates with a corrugated cross section, which are integrally formed by joining the outer peripheries of these thin plates. A conductive material with excellent corrosion resistance is used for the separator 3, and examples of materials that can be used include titanium, titanium alloys, and stainless steel. A cooling flow path through which a cooling medium flows is formed inside the separator 3, and the power generation surface of the power generation cell 1 is cooled by the flow of the cooling medium. For example, water can be used as the cooling medium. The surfaces (front and rear surfaces) of the separator 3 facing the electrode assembly 2 are formed unevenly by press molding or the like so as to form a gas flow path between the separator 3 and the electrode assembly 2.

[0013] The separator 3 on the front side of the electrode assembly 2 is, for example, an anode side separator (anode separator), and an anode flow path through which a fuel gas flows is formed between the anode separator 3 and the assembled electrode assembly 2. The separator 3 on the rear side of the electrode assembly 2 is, for example, a cathode side separator (cathode separator), and a cathode flow path through which an oxidizer gas flows is formed between the cathode separator 3 and the assembled electrode assembly 2. For example, hydrogen gas can be used as the fuel gas, and for example, air can be used as the oxidizer gas. Sometimes, the fuel gas and the oxidizer gas are called reactant gases without being distinguished from each other.

[0014] Fig. 2 is a perspective view showing a schematic configuration of the electrode assembly 2. As shown in Fig. 2, the electrode assembly 2 has a substantially rectangular assembly 20 and a frame 21 that supports the assembly 20. The assembly 20 is a membrane electrode assembly (so-called MEA; Membrane Electrode Assembly), and has an electrolyte membrane, an anode electrode provided on the front surface of the electrolyte membrane, and a cathode electrode provided on the rear surface of the electrolyte membrane.

[0015] The electrolyte membrane is, for example, a solid polymer electrolyte membrane, and a thin film of perfluorosulfonic acid containing water can be used. The electrolyte is not limited to a fluorine-based electrolyte, and a hydrocarbon-based electrolyte can also be used.

[0016] The anode electrode is an electrode catalyst layer formed on the front surface of the electrolyte membrane and serves as a reaction field for the electrode reaction, and a gas diffusion layer is provided on the front surface of the electrode catalyst layer to diffuse and supply the reactant gas. The cathode electrode is an electrode catalyst layer formed on the rear surface of the electrolyte membrane and serves as a reaction field for the electrode reaction, and a gas diffusion layer is provided on the rear surface of the electrode catalyst layer to diffuse and supply the reactant gas. The electrode catalyst layer includes a catalyst metal that promotes the electrochemical reaction between hydrogen contained in the fuel gas and oxygen contained in the oxidant gas, an electrolyte having proton conductivity, and carbon particles having electron conductivity. The gas diffusion layer is composed of a conductive material having gas permeability, such as a carbon porous body.

[0017] At the anode electrode, the fuel gas (hydrogen) supplied via the anode flow path and gas diffusion layer is ionized by the action of a catalyst and passes through the electrolyte membrane to move to the cathode electrode. The electrons generated at this time pass through an external circuit and are extracted as electrical energy. At the cathode electrode, the oxidant gas (oxygen) supplied via the cathode flow path and gas diffusion layer reacts with the hydrogen ions guided from the anode electrode and the electrons that have moved from the anode electrode to produce water. The produced water provides an appropriate humidity to the electrolyte membrane, and excess water is discharged outside the electrode assembly 2.

[0018] The frame 21 is a thin plate having a substantially rectangular shape and is made of insulating resin, rubber, or the like. A substantially rectangular opening 21a is provided in the center of the frame 21, and the joining body 20 is provided so as to cover the entire opening 21a. On the left side of the opening 21a of the frame 21, three through holes 211-213 penetrating the frame 21 in the front-rear direction are opened in a line in the vertical direction, and on the right side of the opening 21a, three through holes 214-216 penetrating the frame 21 in the front-rear direction are opened in a line in the vertical direction.

[0019] As shown in FIG. 1, the separators 3 at the front and rear of the electrode assembly 2 are provided with through holes 311-316 that penetrate the separators 3 in the front-rear direction at positions corresponding to the through holes 211-216 of the frame 21. The through holes 311-316 are connected to the through holes 211-216 of the frame 21, respectively. A collection of the through holes 211-216 and 311-316 that communicate with each other forms flow paths PA1-PA6 (indicated by arrows for convenience) that penetrate the cell stack 101 and extend in the front-rear direction. The flow paths PA1-PA6 are sometimes called manifolds. The flow paths PA1-PA6 are connected to a manifold external to the fuel cell stack 100.

[0020] The flow path PA1 (solid arrow) extending forward through the through holes 211, 311 is a fuel gas supply flow path. The flow path PA6 (solid arrow) extending rearward through the through holes 216, 316 is a fuel gas discharge flow path. The fuel gas supply flow path PA1 and the fuel gas discharge flow path PA6 communicate with the anode flow path facing the front surface of the assembly 20, and as shown by the solid arrow, the fuel gas flows in the left-right direction through the anode flow path via the fuel gas supply flow path PA1 and the fuel gas discharge flow path PA6. The communication between the anode flow path and the other flow paths PA2 to PA5 is blocked via the seal member 7 (FIG. 3). The fuel gas flowing through the fuel gas discharge flow path PA6 is the fuel gas after a part of it has been used in the anode electrode, and this may be called fuel exhaust gas.

[0021] The flow path PA4 (dotted arrow) extending forward through the through holes 214, 314 is an oxidant gas supply flow path. The flow path PA3 (dotted arrow) extending backward through the through holes 213, 313 is an oxidant gas discharge flow path. The oxidant gas supply flow path PA4 and the oxidant gas discharge flow path PA3 communicate with the cathode flow path facing the rear surface of the assembly 20, and as shown by the dotted arrow, the oxidant gas flows in the left-right direction through the cathode flow path via the oxidant gas supply flow path PA4 and the oxidant gas discharge flow path PA3. The communication between the cathode flow path and the other flow paths PA1, PA2, PA5, PA6 is blocked via the seal member 7 (FIG. 3). The oxidant gas flowing through the oxidant gas discharge flow path PA3 is the oxidant gas after a part of it has been used at the cathode electrode, and this may be called an oxidant exhaust gas. The fuel exhaust gas and the oxidant exhaust gas may also be called reaction exhaust gas without distinguishing between them.

[0022] A flow path PA5 (indicated by a dashed line arrow) extending forward through the through holes 215, 315 is a cooling medium supply flow path. A flow path PA2 (indicated by a dashed line arrow) extending rearward through the through holes 212, 312 is a cooling medium discharge flow path. The cooling medium supply flow path PA5 and the cooling medium discharge flow path PA2 are connected to a cooling flow path inside the separator 3, and the cooling medium flows through the cooling flow path via the cooling medium supply flow path PA5 and the cooling medium discharge flow path PA2. Communication between the cooling flow path and the other flow paths PA1, PA3, PA4, PA6 is blocked via a seal member 7 (FIG. 3).

[0023] The end units 102 arranged on both the front and rear sides of the cell stack 101 each have a terminal plate 4, an insulating plate 5, and an end plate 6. The front end unit 102 is sometimes called the dry side end unit, and the rear end unit 102 is sometimes called the wet side end unit. The pair of front and rear terminal plates 4, 4 are arranged on both the front and rear sides of the cell stack 101, sandwiching the cell stack 101 between them. The pair of front and rear insulating plates 5, 5 are arranged on both the front and rear sides of the terminal plate 4, 4 between them. The pair of front and rear end plates 6, 6 are arranged on both the front and rear sides of the insulating plate 5, 5 between them.

[0024] The terminal plate 4 is a metal, substantially rectangular plate-like member, and has a terminal portion for extracting the electric power generated by the electrochemical reaction in the cell stack 101. The insulating plate 5 is a non-conductive, substantially rectangular plate-like member made of resin or rubber, and electrically insulates the terminal plate 4 from the end plate 6. The end plate 6 is a metal or high-strength resin plate-like member, and a connecting member elongated in the front-rear direction that connects the front and rear end plates 6, 6 to each other is fixed to the end plate 6 by a bolt, for example. The fuel cell stack 100 is held in a state in which it is pressed in the front-rear direction by the end plates 6, 6 via the connecting member. A case surrounding the cell stack 101 may be used as the connecting member, and the end plates 6, 6 may be fixed to the front and rear end faces of the case, respectively.

[0025] The rear end unit 102 has a plurality of through holes 102a to 102f penetrating the end unit 102 in the front-rear direction. The through holes 102a to 102f include a through hole penetrating the terminal plate 4, a through hole penetrating the insulating plate 5, and a through hole penetrating the end plate 6, but in FIG. 1, for convenience, these are collectively shown as the through holes 102a to 102f. The through hole 102a is opened on an extension of the fuel gas supply passage PA1 and communicates with the fuel gas supply passage PA1. The through hole 102b is opened on an extension of the cooling medium discharge passage PA2 and communicates with the cooling medium discharge passage PA2. The through hole 102c is opened on an extension of the oxidizing gas discharge passage PA3 and communicates with the oxidizing gas discharge passage PA3. The through hole 102d is opened on an extension of the oxidizing gas supply passage PA4 and communicates with the oxidizing gas supply passage PA4. The through hole 102e is opened on an extension of the coolant supply passage PA5 and communicates with the coolant supply passage PA5. The through hole 102f is opened on an extension of the fuel gas discharge passage PA6 and communicates with the fuel gas discharge passage PA6.

[0026] More specifically, a fuel gas tank storing high-pressure fuel gas is connected to through-hole 102a via an ejector, injector, etc., and the fuel gas in the fuel gas tank is supplied to fuel cell stack 100 via through-hole 102a. A gas-liquid separator is connected to through-hole 102f, and fuel gas (fuel exhaust gas) discharged through through-hole 102f is separated into fuel gas and water by the gas-liquid separator. The separated fuel gas is sucked in via the ejector and supplied again to fuel cell stack 100. The separated water is discharged to the outside via a drain passage.

[0027] A compressor for supplying oxidant gas is connected to through-hole 102d, and the oxidant gas compressed by the compressor is supplied to fuel cell stack 100 via through-hole 102d. Oxidant gas (oxidant exhaust gas) flows out from through-hole 102c. A pump for supplying a cooling medium is connected to through-hole 102e, and the cooling medium is supplied to fuel cell stack 100 via through-hole 102e. The cooling medium is discharged from through-hole 102b. The discharged cooling medium is cooled by heat exchange in the radiator and is supplied again to fuel cell stack 100 via through-hole 102e.

[0028] The above is a schematic configuration of the fuel cell stack 100. The fuel cell stack 100 is housed in a substantially box-shaped case and mounted on a vehicle.

[0029] Fig. 3 is a cross-sectional view taken along line III-III of the power-generating cell 1 in Fig. 1. As shown in Fig. 3, an anode flow path An is formed between the front anode separator 3 and the electrode assembly 2 (joint 20), and a cathode flow path Ca is formed between the rear cathode separator 3 and the electrode assembly 2 (joint 20). Fig. 4 is a front view showing an example of a seal structure near the through-hole 311 (fuel gas supply flow path PA1) of the separator (anode separator) 3, and shows the surface (rear surface) near the through-hole 311 of the separator 3 facing the electrode assembly 2 (frame 21).

[0030] 3 and 4, a plurality of semi-cylindrical protrusions 30 (one in the figure) are provided on the surface of the separator 3 facing the electrode assembly 2 to form communication paths connecting the through-holes 311, 314 (reactant gas supply paths PA1, PA4) and the gas paths An, Ca. Of these communication paths, the communication path connecting the fuel gas supply path PA1 and the cathode path Ca and the communication path connecting the oxidant gas supply path PA4 and the anode path An are closed.

[0031] A seal member 7 is provided on the surface of the separator 3 so as to cross the protrusion 30 and surround the through-holes 311, 314. The seal member 7 may be made of a resin material such as a thermosetting elastomer such as silicone, urethane, or fluorine, a thermoplastic elastomer, synthetic rubber, or natural rubber. The tip of the seal member 7 provided on the surface of the separator 3 is in close contact with the electrode assembly 2 (frame 21), thereby blocking (sealing) the reaction gas supply flow paths PA1, PA4 from the gas flow paths Ca, An that are not in communication with each other and the external space EX.

[0032] 1 is pressed in the front-rear direction by the end plates 6, 6 via the connecting members, a compressive load is applied to the seal member 7 in the front-rear direction, the seal member 7 is pressed and elastically deformed, and the tip of the seal member 7 comes into close contact with the frame 21. At this time, a surface pressure is applied to the tip of the seal member 7 by the compressive load, and the reactant gas supply flow paths PA1, PA4 are kept sealed.

[0033] In this way, when forming an enclosed space facing a plate-like member such as a separator 3 having protrusions 30, in order to ensure sealing performance, it is preferable to make the height of the sealing member 7 uniform. Therefore, in this embodiment, a screen coating tool is configured as follows so that the sealing member 7 of a uniform height across the protrusions 30 can be screen coated on the surface of the separator 3 having the protrusions 30.

[0034] First Embodiment Fig. 5 is a front view showing an example of a screen coating jig (hereinafter, jig) 10A according to a first embodiment of the present invention, and Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5. As shown in Figs. 5 and 6, the jig 10A has a jig body 11 placed on the surface of the separator 3 that will be the coating surface, and a connection part 12 that connects a first part 111 and a second part 112 of the jig body 11.

[0035] The jig body 11 and the connection portion 12 are made of a material having higher rigidity than the seal member 7. The jig body 11 and the connection portion 12 may be made of a metal such as stainless steel. The jig body 11 and the connection portion 12 may be made of a material obtained by subjecting a resin such as Teflon (registered trademark) or silicone to a water-repellent treatment. The width of the connection portion 12 is set to a sufficiently small value (for example, about 100 μm) taking into consideration the material of the seal member 7 so that no steps are generated on the surface of the seal member 7 after coating.

[0036] The jig body 11 has a first surface 11a facing the surface of the separator 3, a second surface 11b opposite to the first surface 11a, and a pair of dividing surfaces 113, 113 extending from the first surface 11a to the second surface 11b and dividing the jig body 11 into a first portion 111 and a second portion 112. In the example of FIG. 5, the pair of dividing surfaces 113, 113 are provided in an annular shape and completely divide the jig body 11 into an inner first portion 111 surrounded by the pair of dividing surfaces 113, 113 and an outer second portion 112. The pair of dividing surfaces 113, 113 may be provided in a line segment or a curved segment and may partially divide the jig body 11 into the first portion 111 and the second portion 112. In this case, the jig 10A may be configured only by the jig body 11, without providing the connection portion 12 that connects the first portion 111 and the second portion 112. Hereinafter, the space between the first portion 111 and the second portion 112, in other words, the space between the first surface 11a and the second surface 11b and between the pair of dividing surfaces 113, 113, will be referred to as a groove portion 13.

[0037] The jig body 11 is formed, for example, by molding a lower layer 14 including the first surface 11a and an upper layer 15 including the second surface 11b as separate bodies, and then joining the lower layer 14 and the upper layer 15. In this case, the lower layer 14 includes a first portion 111 and a second portion 112, and the upper layer 15 includes the first portion 111, the second portion 112, and the connection portion 12. The jig body 11 and the connection portion 12 may be integrally molded, and the jig body 11 may be divided into the first portion 111 and the second portion 112 and the connection portion 12 may be formed by processing such as etching or milling.

[0038] FIG. 7 is a perspective view partially showing the jig 10A, and shows a schematic diagram of a state in which the seal member 7 is screen-coated on the surface of the separator 3 having the protrusions 30 so as to cross the protrusions 30 using the jig 10A. As shown in FIG. 7, in the screen coating, the jig 10A is first placed on the surface of the separator 3 to be coated so that the first surface 11a of the jig body 11 faces the surface of the separator 3 having the protrusions 30. Next, a paste P of a resin material such as a thermosetting elastomer such as silicone, urethane, or fluorine having thixotropy, a thermoplastic elastomer, synthetic rubber, or natural rubber is placed on the second surface 11b of the jig body 11. Then, the paste P is pressed against the second surface 11b around the grooves 13 by the squeegee 16, and the paste P is applied to the surface of the separator 3 through the grooves 13 by sliding the squeegee 16, and the seal member 7 is applied and formed on the surface of the separator 3 by hardening it. Such screen coating may be performed manually, or may be performed automatically using a screen printing device having a mounting table for fixing the separator 3, a jig 10A, and a squeegee 16.

[0039] The first surface 11a of the jig body 11 has a pair of recesses 115, 115 that fit into the protrusion 30 of the separator 3, starting from intersections 114, 114 with the pair of dividing surfaces 113, 113. One of the pair of recesses 115, 115 is provided in the first portion 111 of the jig body 11, and the other is provided in the second portion 112 of the jig body 11. When the jig body 11 is made of metal, only the recesses 115 may be made of a material obtained by subjecting a resin such as Teflon (registered trademark) or silicone to a water-repellent treatment.

[0040] By providing the first surface 11a of the jig body 11 facing the surface to be coated with the recesses 115 that fit into the protrusions 30 on the surface of the separator 3, it is possible to restrict the displacement of the jig body 11 relative to the surface to be coated even if a pressing force is applied to the jig 10A in the sliding direction of the squeegee 16 during coating. This allows screen coating to be performed on the surface of the separator 3 with high precision.

[0041] In this way, by performing screen coating using the jig body 11, which is relatively more rigid than the sealing member 7, and the squeegee 16, it is possible to prevent the sealing member 7 from being coated outside the groove portion 13, and to coat and form the sealing member 7 in a shape that follows the shape of the groove portion 13.

[0042] The jig body 11 is formed so that the depth of the groove 13, i.e., the height h1 from the first surface 11a to the second surface 11b of the pair of divided surfaces 113, 113, is uniform. Therefore, the height of the seal member 7 that is applied and formed along the shape of the groove 13 defined by the pair of divided surfaces 113, 113 of the jig body 11, the first surface 11a (surface of the separator 3), and the second surface 11b (squeegee 16) can be made roughly uniform.

[0043] FIG. 8 is a cross-sectional view of the seal member 7 applied to the surface of the separator 3, and FIG. 9 is a diagram for explaining the characteristics (thixotropy) of the resin material constituting the seal member 7. As shown in FIG. 8 and FIG. 9, the thickness d of the seal member 7 made of a resin material having thixotropy after hardening is determined according to the width w of the portion in contact with the surface of the separator 3, if the application conditions such as the composition of the paste P are the same. That is, the larger (wider) the width w of the seal member 7, the larger (higher) the thickness d of the seal member 7, and the smaller (narrower) the width w of the seal member 7, the smaller (lower) the thickness d of the seal member 7. The width w of the seal member 7 corresponds to the width w of the groove portion 13 of the jig 10A, that is, the width w between the pair of divided surfaces 113, 113 of the jig body 11.

[0044] Fig. 10 is a cross-sectional view of the seal member 7 applied by the jig 10A, and Fig. 11 is a perspective view of the seal member 7 applied by the jig 10A. As shown in Fig. 10 and Fig. 11, the width w and thickness d of the seal member 7 applied by the jig 10A are uniform along the extension direction of the seal member 7. Since the seal member 7 extends along the surface of the separator 3 including the protruding portion 30, the height h2 of the seal member 7 from the surface of the separator 3 is higher at the position where the seal member 7 crosses the protruding portion 30 by the amount of the protruding portion 30 than at other positions.

[0045] In this way, if there is variation in the height h2 of the seal member 7 from the surface of the separator 3, the line pressure (sealing load) applied to the tip of the seal member 7 that comes into contact with the frame 21 in Fig. 3 will vary in the extension direction of the seal member 7 in Fig. 4, which may cause leakage at locations where the line pressure is low. Note that the line pressure is the average value per unit length in the extension direction of the seal member 7 of the surface pressure applied to the tip of the seal member 7 that comes into contact with the frame 21 due to a compressive load.

[0046] <Second embodiment> FIG. 12 is a perspective view partially showing a jig 10B according to a second embodiment of the present invention, FIG. 13 is a cross-sectional view of the seal member 7 applied by the jig 10B, and FIG. 14 is a perspective view of the seal member 7 applied by the jig 10B. Regarding the differences from the first embodiment, the jig 10B is configured so that the width w between a pair of divided surfaces 113, 113 of the jig body 11 (width w of the groove portion 13) is narrowed at a position corresponding to the recess 115. More specifically, as shown in FIG. 12, the width w1 of the groove portion 13 at the position corresponding to the recess 115 is set to a smaller value than the width w2 of the groove portion 13 at other positions (w1 <w2)。

[0047] 13 and 14, the height h2 of the seal member 7 applied by the jig 10B from the surface of the separator 3 becomes uniform along the extension direction of the seal member 7. That is, the width w1 of the seal member 7 at the position where the seal member 7 crosses the protrusion 30 becomes smaller than the width w2 of the seal member 7 at other positions, and the thickness d of the seal member 7 at the position where the seal member 7 crosses the protrusion 30 becomes smaller than the other positions. As a result, the height h2 of the seal member 7 from the surface of the separator 3 becomes uniform along the extension direction of the seal member 7, eliminating variations in the line pressure (sealing load) applied to the tip of the seal member 7 that comes into close contact with the frame 21 in FIG. 3, and improving the sealing performance.

[0048] The widths w1 and w2 of the groove 13 of the sealing member 7 and the jig 10B are set depending on the maximum pressure of the gas flowing through the gas flow path, the material of the sealing member 7, the compressive load applied to the sealing member 7, etc. The ratio of the width w1 to the width w2 may be determined based on the application position of the sealing member 7 on the surface of the separator 3, the shape of the protruding portion 30, the properties of the resin material shown in FIG.

[0049] 15 is a front view showing an example of a sealing structure of a plate-like member according to the second embodiment, and shows the sealing structure near a through-hole 311 (fuel gas supply flow path PA1) of a separator (anode separator) 3 facing an electrode assembly 2 (frame 21). As shown in FIG. 15, the sealing structure of the plate-like member has a separator 3 having a protruding portion 30, and a sealing member 7 provided on the surface of the separator 3 so as to cross the protruding portion 30. The sealing member 7 has a uniform height h2 from the surface of the separator 3, and the width w (w1, w2) of the sealing member 7 narrows at a position crossing the protruding portion 30.

[0050] Thus, in the second embodiment, unlike the first embodiment, the jig 10B is configured so that the width w between the pair of divided surfaces 113, 113 of the jig body 11 (width w of the groove portion 13) is narrow at a position corresponding to the recess 115, thereby making it possible to form a seal member 7 of a uniform height. Furthermore, since the height h1 of the groove portion 13 of the jig 10B is uniform, the seal member 7 can be formed in accordance with the shape of the groove portion 13 by a single screen coating using the squeegee 16, as in the first embodiment.

[0051] According to this embodiment, the following advantageous effects can be obtained. (1) A jig 10B for screen-coating the seal member 7 on the surface of a separator 3 having a protruding portion 30 so as to cross the protruding portion 30 has a jig body 11 made of a member having a higher rigidity than the seal member 7 and placed on the surface of the separator 3 (FIG. 12). The jig body 11 has a first surface 11a facing the surface of the separator 3, a second surface 11b opposite to the first surface 11a, and a pair of dividing surfaces 113, 113 extending from the first surface 11a to the second surface 11b and dividing at least a part of the jig body 11 into a first portion 111 and a second portion 112. The first surface 11a has recesses 115, 115 that engage with the protruding portion 30 of the separator 3, starting from intersections 114, 114 with the pair of dividing surfaces 113, 113. The pair of divided surfaces 113, 113 have a uniform height h1 from the first surface 11a to the second surface 11b, and the width w between the pair of divided surfaces 113, 113 narrows at positions corresponding to the pair of recesses 115, 115.

[0052] In this way, by providing the recess 115 that fits into the protrusion 30 on the surface of the separator 3, the displacement of the jig body 11 relative to the coating surface during coating is restricted, and the screen coating can be performed accurately on the surface of the separator 3. In addition, by performing screen coating using the jig body 11 that is relatively more rigid than the seal member 7, the seal member 7 is prevented from being coated outside the groove portion 13, and the seal member 7 having a shape that matches the shape of the groove portion 13 can be coated and formed. In addition, by making the depth (height) h1 of the groove portion 13 uniform, the seal member 7 can be formed by one screen coating using the squeegee 16. Furthermore, by narrowing the width w of the groove portion 13 at a position corresponding to the recess 115 that fits into the protrusion 30 on the surface of the separator 3, the seal member 7 is prevented from rising at a position crossing the protrusion 30, and the seal member 7 having a uniform height h2 can be formed.

[0053] (2) The protrusions 30 have a curved cross-sectional shape, for example, a semi-cylindrical shape ( FIG. 12 ). Even if the protrusions 30 are curved and the seal member 7 applied to the protrusions 30 tends to spread, the width w of the grooves 13 and the seal member 7 is narrowed at the position crossing the protrusions 30, thereby preventing the seal member 7 from swelling at the position crossing the protrusions 30 and forming a seal member 7 with a uniform height h2.

[0054] (3) The pair of dividing surfaces 113, 113 surround one of the first portion 111 and the second portion 112 ( FIG. 12 ). The jig 10B further has a connecting portion 12 that connects the first portion 111 and the second portion 112. Even if the pair of dividing surfaces 113, 113 (groove portion 13) are provided in an annular shape and the jig body 11 is completely separated, providing the connecting portion 12 enables accurate screen coating.

[0055] (4) The sealing member 7 is a resin member. Even if the sealing member 7 is applied through the groove portion 13 of the jig 10, the aspect ratio of 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 h2 of the sealing member 7 from the surface of the separator 3 after curing can be made uniform by narrowing the width w at the position crossing the protrusion 30 where the thickness d should be small.

[0056] (5) The sealing structure of the plate-like member has a separator 3 having a protrusion 30, and a sealing member 7 provided on the surface of the separator 3 so as to cross the protrusion 30 (FIGS. 13 to 15). The sealing member 7 has a uniform height h2 from the surface of the separator 3, and the width w of the sealing member 7 narrows at the position where it crosses the protrusion 30. When using the sealing member 7 to form a sealed space facing a plate-like member such as the separator 3 having the protrusion 30, the sealing performance of the sealed space can be ensured by making the height h2 of the sealing member 7 uniform.

[0057] In the above embodiment, the screen coating jig for screen coating the seal member 7 on the surface of the separator 3 of the fuel cell so as to cross the convex portion 30 forming a gas communication path and the seal structure of the separator 3 are described as examples, but the screen coating jig and the seal structure of the plate-shaped member are not limited to these. The convex portion may be one that protrudes from the surface of the plate-shaped member to which the seal member is applied, and is not limited to one that is hollow and forms a communication path for gas or the like. The seal member may be one that crosses the convex portion, and the extension direction of the convex portion and the extension direction of the seal member do not need to be perpendicular to each other. The surface of the plate-shaped member may have a convex portion and a portion other than the convex portion, and the area occupied by the convex portion does not need to be smaller than the area occupied by the portion other than the convex portion. For example, the present invention can be applied to a plate-shaped member having a concave portion such as a groove in a part thereof by regarding the portion other than the concave portion as the convex portion. In this case, the width of the sealing member is configured to be wider at a position crossing the recess of such a plate-like member, and the width between a pair of dividing surfaces of the jig body is configured to be wider at positions corresponding to the protrusions that fit into the recesses of such a plate-like member, thereby making it possible to form a sealing member of uniform height.

[0058] The above description is merely an example, and the present invention is not limited to the above-mentioned embodiment and modifications, as long as the features of the present invention are not impaired. The above-mentioned embodiment and one or more modifications can be arbitrarily combined, and modifications can be combined with each other. [Explanation of symbols]

[0059] REFERENCE SIGNS LIST 1 power generation cell, 2 electrode assembly, 3 separator, 7 seal member, 10A, 10B screen coating jig (jig), 11 jig body, 11a first surface, 11b second surface, 12 connection portion, 13 groove portion, 14 lower layer, 15 upper layer, 16 squeegee, 20 bonded body, 21 frame, 30 convex portion, 100 fuel cell stack, 111 first portion, 112 second portion, 113 dividing surface, 114 intersection portion, 115 concave portion

Claims

1. A screen coating tool for screen coating a sealant on a surface of a plate-like member having a convex portion so as to cross the convex portion, a jig body that is made of a member having a higher rigidity than the sealing member and is placed on a surface of the plate-like member; The jig body is A first surface facing the front surface of the plate-like member; a second surface opposite the first surface; and a pair of dividing surfaces extending from the first surface to the second surface and dividing at least a portion of the jig body into a first portion and a second portion; the first surface has a recess that starts at an intersection with the pair of dividing surfaces and that fits into the protrusion of the plate-like member, The pair of dividing surfaces has a uniform height from the first surface to the second surface, A screen coating tool, characterized in that a width between the pair of divided surfaces narrows at positions corresponding to the pair of recesses.

2. The screen coating tool according to claim 1, The screen coating tool is characterized in that the convex portion has a curved cross-sectional shape.

3. The screen coating tool according to claim 1 or 2, the pair of dividing surfaces surrounds one of the first portion and the second portion, The screen coating tool further comprises a connection portion that connects the first portion and the second portion.

4. The screen coating tool according to claim 1 or 2, The screen coating tool, wherein the sealing member is a resin member.

5. A plate-like member having a protrusion; a seal member provided on the surface of the plate-like member so as to cross the protrusion, the sealing member has a uniform height from the surface of the plate-like member; A seal structure for a plate-like member, wherein the width of the seal member narrows at a position crossing the protrusion.

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