JP5067055B2 - Fuel cell and fuel cell manufacturing method - Google Patents

Description

  The present invention relates to a fuel cell including a cell stack including a plurality of stacked fuel battery cells, and electrochemically generating electric power using a reaction gas, and more particularly to fastening a cell stack of a fuel cell.

  The fastening structure for fastening the cell stack of the fuel cell includes a pair of end plates that abut the cell stack at both ends in the stacking direction of the cell stack, and a pair of cells along the stacking direction of the cell stack. A configuration has been proposed in which a shaft-shaped side member disposed between end plates is provided and the end plate and the side member are fastened by a fastening bolt (for example, Patent Documents 1 and 2).

JP 2004-185845 A JP 2006-302900 A

  FIG. 14 is an explanatory view for explaining a fastening structure conventionally employed. As shown in the upper part of FIG. 14, when the end plate 61r and the side member 62r are fastened by the fastening bolt 64r along the stacking direction, the cell stack between the end plates receives a pressing force by both end plates, A reaction force is exerted on the end plate 61r. This reaction force acts on the plate so as to bend the end plate 61r outward in the stacking direction of the cell stack as shown in the figure. For this reason, as shown in the lower stage of FIG. 14, the end plate 61r exerts a lever action on the fastening bolt 64r with a portion in contact with the side member 62r on the end plate end face side as a fulcrum Ps. Will receive. By this nail extraction action, stress concentrates on a part Pb of the fastening bolt 64r in the vicinity where the end plate 61r and the side member 62r abut. Therefore, in such a fastening structure, it is necessary to sufficiently increase the size of the fastening bolt in order to ensure sufficient strength when fastening the cell stack, and as a result, the fuel cell becomes large. The problem was pointed out.

  In view of the above-described problems, an object of the present invention is to improve the fastening strength with bolts when fastening a cell laminate.

  In order to achieve at least a part of the above object, the present invention adopts the following configuration.

[Application 1: Fuel cell]
A fuel cell that generates electricity electrochemically using a reaction gas,
A cell stack comprising a plurality of stacked fuel cells; and
A pair of end plates in contact with the cell stack at both ends in the stacking direction in which the plurality of fuel cells in the cell stack are stacked;
A shaft-shaped side member that is disposed between the pair of end plates along the stacking direction and is shorter than the stacking direction length of the cell stack,
A bolt shaft that protrudes from the end surface of the side member along the stacking direction and penetrates the end plate is provided, and the bolt shaft is screwed into a female screw hole into which the bolt shaft is screwed, so that the end plate and the side A fastening bolt portion for fastening the member;
The gist of the present invention is to provide a filling base material that is filled and hardened so as to surround the bolt shaft so as to surround the gap between the short side member and the end plate.

[Application 2: Manufacturing method of fuel cell]
A method for producing a fuel cell comprising a cell laminate in which a plurality of fuel cells that are units of electrochemical power generation using a reaction gas are laminated,
The end plate is brought into contact with both ends of the fuel cell in the stacking direction of the cell stack,
Between the end plates at both ends of the cell laminate, a shaft-shaped side member shorter than the stacking direction length of the cell laminate is disposed,
The bolt shaft is tightened with a fastening bolt portion that projects from the end surface of the side member along the stacking direction and is screwed into a female screw hole into which the bolt shaft is screwed. Fastening the cell stack between the end plates leaving a gap between the short side members and the end plates;
The gist is to fill the gap with a filling base material so as to surround the bolt shaft, and to cure the filling base material.

  When fastening the cell stack that the fuel cell has, the end bolts positioned at both ends of the cell stack and contacting the end faces of the stack and the side members between the end plates are fastened by the fastening bolts. Thus, the cell laminate between the end plates is fastened. This fastening is performed by passing the bolt shaft of the fastening bolt through the end plate to reach the female screw hole of the side member, and screwing the bolt shaft into the female screw hole of the side member. Alternatively, it is made by screwing a nut having a female screw hole on the bolt shaft protruding from the end face of the side member and penetrating the end plate outside the end plate.

  By the way, since the side member is a shaft shorter than the length in the stacking direction of the cell stack, the cell stack is fastened by a fastening bolt with a gap left between the side member and the end plate. The The gap is filled with a filling base material that is filled and hardened so as to surround the bolt shaft. However, in the state where the fastening is performed, the gap is left between the side member and the end plate. Can do. That is, the cell stack can be fastened without bringing the end plate into contact with the end surface of the side member.

  Then, as described in FIG. 14, even if the cell stack that has been fastened exerts a reaction force against the pressing on the end plate, the end plate that receives this reaction force is stacked in accordance with the reaction force. Although it bends outward in the direction, it does not cause contact with the side member on the end face side of the end plate, so that it does not exert a nail pulling action on the fastening bolt. Therefore, when fastening the cell laminate through the bolt shaft screwing of the fastening bolt into the female screw hole on the side member end face, it is possible to prevent stress concentration due to the nail pulling action from occurring on the fastening bolt. It is possible to ensure or improve the strength when performing the above without inadvertently increasing the size of the fastening bolt. For this reason, enlargement of the fuel cell can be avoided with high effectiveness. Then, in a state in which the cell stack is fastened through the bolt shaft screwing described above, the gap between the side member and the end plate is filled with the filling base material so as to surround the bolt shaft, and the filling base material is cured. Let Therefore, fastening of the cell laminate after curing of the filling base material is in a state where the filling base material and the side member in the gap are integrated. Such integration of the filling base material and the side member contributes to improvement of rigidity for restraining the fuel cell, and therefore, impact resistance to external force applied to the fuel cell from the direction intersecting the stacking direction of the cell stack. Will also increase.

  The fuel cell described above can be configured as follows. For example, when filling the gap between the side member and the end plate in the fastening state of the cell laminate through the bolt shaft screwing with the filling base material, first, a spacer is provided between the end face of the side member and the end plate in the gap. Then, the gap between the spacer and the side member end surface and / or the gap between the spacer and the end plate can be filled with an adhesive and cured. In this way, the spacer interposed in the gap is integrated with the side member by the adhesive and is also integrated with the end plate, so that the strength as a filling base material filling the gap can be secured.

  Also, after fastening the cell stack with fastening bolts, the spacer can be attached to the bolt shaft in a gap so as to surround the bolt shaft, for example, a cylindrical body having a through-hole having a diameter larger than the shaft diameter of the bolt shaft Can be a spacer that is divided in the axial direction of the through hole, or a spacer having a slit into which the bolt shaft enters. If it carries out like this, the spacer mounting | wearing after the cell laminated body fastening with a fastening bolt will become easy, and simplification of an operation | work can be advanced.

  Further, if the adhesive is a composite material in which a dispersion material is dispersed in a base material, the strength as a filling base material composed of a cured adhesive and a spacer can be increased. It can contribute to improvement. In this case, the filled base material itself can be a composite material that hardens after gap filling, for example, a fiber-reinforced composite material (plastic).

  Hereinafter, embodiments of the present invention will be described based on examples. FIG. 1 is a perspective view showing an overall configuration of a fuel cell 10 as an embodiment of the present invention, FIG. 2 is an exploded perspective view showing an essential part of the overall configuration of the fuel cell 10, and FIG. FIG. 4 is an explanatory view showing a detailed configuration of the cell stack 50. FIG. As illustrated in the drawings, the fuel cell 10 includes a cell stack 50 including a plurality of stacked fuel battery cells, and a fastening mechanism 60 that fastens the cell stack 50, and illustrates a tank, a reformer, and the like. Electricity is generated by the electrochemical reaction of the reaction gas supplied from the gas supply unit that does not.

  In the present embodiment, the fuel cell 10 includes a solid polymer type fuel cell, and the reaction gas used in the fuel cell 10 includes a fuel gas containing hydrogen and an oxidizing gas containing oxygen. The fuel gas used in the fuel cell 10 may be a hydrogen gas stored in a hydrogen tank or a hydrogen storage alloy, or may be a hydrogen gas obtained by reforming a hydrocarbon fuel. As the oxidizing gas used in the fuel cell 10, for example, air taken from outside air can be used. In this embodiment, the fuel cell 10 is a circulation type fuel cell that circulates and reuses the fuel gas, and the hydrogen concentration of the fuel gas supplied to the fuel cell 10 decreases as the electrochemical reaction proceeds. Then, the anode off gas is discharged to the outside of the fuel cell 10, and the anode off gas is reused as the fuel gas. The oxidizing gas supplied to the fuel cell 10 decreases in oxygen concentration with the progress of the electrochemical reaction, and is discharged outside the fuel cell 10 as a cathode off gas.

  As shown in FIG. 4, the cell laminate 50 is configured by laminating a plurality of plate-like members formed in substantially the same shape, and the cell laminate 50 is a columnar solid whose cross section is the shape of these members. It becomes. In this embodiment, as shown in FIGS. 2 and 4, the cell stack 50 has a shape in which four corners of a rectangular cross section are cut out from the upper surface to the bottom surface of the rectangular parallelepiped. The cell stack 50 of the fuel cell 10 includes a power generation plate 300 having a membrane electrode assembly (MEA) 320 in which an electrochemical reaction of a reaction gas is performed, and a separator 200 that supplies the reaction gas to the power generation plate 300. A plurality of power generation plates 300 and separators 200 are alternately stacked. As a result, a plurality of fuel cells in which the power generation plate 300 is sandwiched between the two separators 200 are formed in the cell stack 50. The cell stack 50 includes a pair of terminals 120 and 420 for collecting electricity generated in each of the fuel cells by sandwiching a stack structure in which separators 200 and power generation plates 300 are alternately stacked from both sides, and a terminal 120, The stack structure sandwiched by 420 is further sandwiched from both sides to electrically insulate the pair of insulators 110 and 410.

  In this embodiment, as shown in FIGS. 1 to 3, the fuel cell 10 includes a restraint sheet 510 that protects the cell stack 50, and the side surface along the stacking direction Ds of the cell stack 50 is the restraint sheet 510. Wrapped by. In this embodiment, the restraint sheet 510 includes a sheet-like member made of rubber or urethane.

  As shown in FIGS. 1 to 3, the fastening mechanism 60 of the fuel cell 10 includes a pair of end plates 61 and 63 that sandwich the cell stack 50 from both ends in the stacking direction Ds, and a cell stack between the two end plates. 50, the side members 62 disposed along the stacking direction Ds, the end plates 61 and 63, the side members 62, and the fastening bolts 64 involved in fastening the cell stack 50, and the end plates 61. , 63 and a filling member 66 disposed and formed between each of the side members 62. In this case, the side members 62 are prepared at the four corners of the cell stack 50 and are shafts (rectangular shafts) shorter than the length of the cell stack 50 in the stacking direction.

  As shown in FIG. 1 and FIG. 3 showing the fuel cell 10 as a finished product, the filling joint portion 66 of the fastening mechanism 60 has a spacer 660 and a gap between the spacer, the end face of the side member, and the side member in this embodiment. And an adhesive layer 670 cured in step (b). The configuration and formation of the filling joint portion 66 are as follows.

  FIG. 5 is an enlarged cross-sectional view showing a state in which the end plate 61 and the side member 62 facing each other are connected by the fastening bolt 64 and the filling joint portion 66 in an enlarged cross-sectional view. FIG. 6 is an explanatory view showing the state of connection between the end plate 61 and the side member 62 in an exploded view, and FIG. 7 is an explanatory view showing the state of connection between the end plate 61 and the side member 62 in perspective. is there. The fastening bolt 64 that constitutes the fastening mechanism 60 is a metal bolt having a round rod-like bolt shaft 644. One end of the bolt shaft 644 is a male screw portion 646, and the other end is a hexagonal bolt head 642. To do. The bolt head 642 is larger than the diameter of the through hole 614 of the end plate 61, and the bolt shaft 644 is smaller in diameter than the through hole 614 of the end plate 61 and the passage hole 624 of the side member 62.

  As shown in FIGS. 1 to 3, the end plates 61 and 63 of the fastening mechanism 60 are metal plate-like members that match the cross-sectional shape of the cell stack 50. The end plates 61 and 63 have through holes 614 that are provided at positions corresponding to the side members 62 and pass through the fastening bolts 64 substantially along the stacking direction Ds. The end plate 61 includes the reaction gas in addition to the through holes 614. And a through hole 618 communicating with the flow path provided in the cell stack 50 for supplying and discharging cooling water. As shown in FIGS. 5 to 7, the through holes 614 of the end plates 61 and 63 are larger in diameter than the diameter of the bolt shaft 644 of the fastening bolt 64.

  The side member 62 of the fastening mechanism 60 serves as a guide hole for the bolt shaft 644 and a female screw hole 626 that engages with the male screw portion 646 of the fastening bolt 64 on each end side of the end plate 61 side and the end plate 63 side. And a passage hole 624. In the present embodiment, the fuel cell 10 includes four side members 62 formed in a prismatic shape, and these four side members 62 fit into corner step portions at the four corners of the cell stack 50 from the restraint sheet 510, respectively. So as to be in contact with each other.

  The spacer 660 of the filling joint portion 66 is a so-called two-piece member obtained by dividing a cylindrical body having a through hole 661 having a diameter larger than the axial diameter of the bolt shaft 644 in the axial direction of the through hole 661. In this embodiment, when the two spacers 660 face each other on the side of the through hole 661, the outer shape (rectangular shape) is substantially the same as that of the side member 62. In this case, one spacer 660 is attached to the corner step portion of the cell stack 50 when the side member 62 is disposed at the four corners of the cell stack 50 as described above. Therefore, the spacer 660 surrounds the bolt shaft 644 by disposing the other spacer 660 so as to face the spacer 660 already attached to the corner step portion of the cell stack 50. Such spacer mounting can be performed after the cell stack 50 is fastened by the fastening bolt 64 because the spacer 660 is the above-described two-piece member.

  Next, a manufacturing process of the fuel cell 10, specifically, a state of fastening of the cell stack 50 will be described. FIG. 8 is an explanatory diagram for explaining a procedure for fastening the cell stack 50. When the fuel cell 10 is manufactured, first, the cell stack 50 shown in FIG. 4 is manufactured, and the cell stack 50 is sandwiched between opposing end plates 61 and 63 as shown in FIG. Thereby, the cell laminated body 50 contacts the end plates 61 and 63 at both ends thereof. Next, between the end plates 61 and 63 at both ends of the cell stack 50, the side members 62 that are shorter than the length in the stacking direction of the cell stack 50 as described above are connected to each corner step of the cell stack 50. It arranges in the part. At the same time as or after the side member arrangement, one spacer 660 is arranged at each corner step portion of the cell stack 50. In this case, when the side member 62 is made shorter than the length in the stacking direction of the cell stack 50, the side member 62 is placed between the end surface of the side member 62 and the end plates 61 and 63 as shown in FIG. The length of the side member is defined so that a gap K greater than the thickness of the member 62 is formed.

  When the arrangement of the side member 62 is completed, the fastening bolt 64 is inserted into the through hole 614 from the outside of the end plate 61, and the male screw portion 646 at the tip of the bolt is screwed into the female screw hole 626 in the side member 62. Then, the fastening bolt 64 is tightened with a predetermined tightening torque defined when the cell stack 50 is fastened. By this bolt fastening, the cell stack 50 is fastened between the end plates 61 and 63. The state where the fastening of the cell stack 50 is completed is shown in FIG. 8A. In this state, since the side member 62 is short as already described, the side member 62 and both ends thereof are arranged. A gap K is formed between the side end plates 61 and 63. In this case, one spacer 660 is already attached to the cell stack 50 in the gap K, but does not fill the gap K.

  After completing the fastening of the cell stack 50, the other spacer 660 is mounted facing the spacer 660 mounted on the cell stack 50, as shown in FIG. 8B. Thus, the facing spacers 660 are attached to the bolt shaft 644 at the gap K so as to surround the bolt shaft 644 after the cell stack 50 is fastened by the fastening bolt 64.

  Next, as shown in FIG. 8C, the epoxy adhesive is injected and filled into the gaps on both sides of the spacer 660 from the epoxy adhesive container SC to cure the filled adhesive. Thus, the gap K is filled so that the bolt shaft 644 of the fastening bolt 64 is surrounded by the spacer 660 and the cured epoxy adhesive. This cured epoxy adhesive becomes the adhesive layer 670. The side member 62 supports the end plates 61 and 63 at both ends of the cell stack 50 after being integrated with the epoxy adhesive cured in the gap K and the spacer 660. In this case, in injecting and filling the epoxy adhesive into the gap K, if the spacer 660 is in contact with the end face of the side member or the end plate, the epoxy adhesive is applied to one side of the spacer 660. It is also possible to inject and fill.

  As described above, in the fuel cell 10 according to the present embodiment, when the cell stack 50 is fastened, the end plates 61 and 63 that are located at both ends of the cell stack 50 and are in contact with the end faces of the stack, and both the end plates The side members 62 between the end plates are fastened with fastening bolts 64, thereby fastening the cell stack 50 between the end plates. In this fastening, the male screw portion 646 at the tip of the bolt shaft of the fastening bolt 64 passes through the end plates 61 and 63 to reach the female screw hole 626 of the side member 52, and the male screw portion 646 is connected to the female screw hole of the side member 62. This is done by screwing to 626 and tightening the fastening bolt 64 with a predetermined torque. Since the side member 62 has a short size as described above, the fastening bolt 64 is tightened between the end surface of the side member 62 and the end plates 61 and 63 as shown in FIG. This is done with the gap K left. In this case, one spacer 660 exists in the gap K, but the gap K remains between the end face of the side member 62 and the end plates 61 and 63 on the end plate end face side, the upper end side in the figure. There is no change. Therefore, the cell stack 50 can be fastened without causing the end plates 61 and 63 to contact the end surface of the side member 62.

  In this embodiment, after the fastening of the cell stack 50 is completed in this manner, the other spacer 660 is mounted facing the spacer 660 mounted on the cell stack 50 as shown in FIG. 8B. Then, as shown in FIG. 8C, the gap K is filled with an epoxy adhesive to cure the adhesive, and an adhesive layer 670 is formed on both sides of the spacer 660 facing each other. After the adhesive layer 670 is formed, the side member 62, the spacer 660, and the adhesive layer 670 are integrated to support the end plates 61 and 63 at both ends of the cell stack 50.

  Therefore, when the cell stack 50 shown in FIG. 8A is fastened, the end plates 61 and 63 are subjected to the reaction force against the pressure from the cell stack 50 to the outside of the cell stack 50 in the stacking direction. Although it bends, it does not contact the side member 62 on the end plate end face side. For this reason, since the end plates 61 and 63 do not exert the nail extraction action due to the lever action upon the fastening of the cell stack 50, the stress concentration due to the nail extraction action can be prevented from occurring in the fastening bolt 64. As a result, in the fuel cell 10 of the present embodiment, the strength (fastening strength) when the cell stack 50 is fastened can be secured without inadvertently increasing the size of the fastening bolt 64. In other words, when the cell stack 50 is fastened using the fastening bolts 64 of the same size, the fastening strength of the cell stack 50 can be improved. For this reason, according to the present Example, size reduction of the fuel cell 10 can be promoted.

  Moreover, in the fuel cell 10 of the present embodiment, after the cell stack 50 is fastened by the fastening bolt 64, the epoxy adhesive with the spacer 660 interposed in the gap K between the side member 62 and the end plates 61, 63. Is cured to form the adhesive layer 670, and the gap K is filled so as to be surrounded by the spacer 660 and the adhesive layer 670, and the side member 62, the spacer 660, and the adhesive layer 670 are integrated to form a cell stack. The end plates 61 and 63 at both ends of the body 50 are supported. For this reason, the strength of the spacer 660 and the adhesive layer 670 filling the gap K is ensured by the integration of the spacer 660 and the side member 62 via the adhesive layer 670 and the integration of the end plates 61 and 63. Above, the rigidity which restrains the fuel cell 10 along the lamination direction of the cell laminated body 50 can be improved. Therefore, the impact resistance against the external force applied to the fuel cell 10 from the direction intersecting the stacking direction of the cell stack 50 is also increased. In this case, in this embodiment, the outer shape of the facing spacer 660 is a rectangular shape similar to that of the side member 62. Therefore, the opposing area of the side member 62 and the spacer 660, that is, the bonding area by the adhesive layer 670 increases. In view of the above integration, it is preferable.

  In this embodiment, one spacer 660 is attached to the cell laminate 50 prior to fastening of the cell stack 50, and after the fastening, the other spacer 660 can be easily attached facing the already installed spacer 660. . Therefore, the work at the time of manufacturing the fuel cell can be simplified.

  Next, another embodiment will be described. FIG. 9 is an exploded perspective view corresponding to FIG. 2 and an exploded perspective view showing an essential part of the overall configuration of the fuel cell 10 of another embodiment. FIG. 10 is an equivalent view of FIG. It is explanatory drawing which shows the mode of a connection with 61 and the side member 62 by a perspective view. As shown in the figure, in this embodiment, the spacer 663 used has a slit 664 having a width larger than the diameter of the bolt shaft 644 of the fastening bolt 64. When this spacer 663 is used, the cell stack 50 is fastened with the spacer 663 not attached. After the fastening, the spacer 663 is attached so that the bolt shaft 644 enters the spacer 663. As described above, the adhesive layer 670 is formed with an epoxy adhesive. Also according to this embodiment, the above-described effects can be achieved.

  FIG. 11 is an enlarged cross-sectional view showing a state of connection between the side member 62 and the end plate 61 in another embodiment in a state where the cell laminated body fastening is completed, and FIG. 12 is an enlarged cross-sectional view in this embodiment. It is explanatory drawing which shows the mode of the connection of the side member 62 and the end plate 61 at the time of a cell laminated body fastening in a perspective view.

  As shown in FIG. 11, in this embodiment, the side member 62 includes a cylindrical guide tube portion 627 at the tip, and a sleeve 665 is loosely fitted on the outer periphery of the tube portion. The sleeve 665 moves in the axial direction on the outer periphery of the guide tube portion 627 and has a slit 666 along the axial direction. The slit 666 is for injecting an epoxy-based adhesive, and the slit path has a circular shape in part for convenience of injecting the adhesive into the interior. In the completed fuel cell 10, as shown in FIG. 11, the sleeve 665 is positioned so as to contact the end plate 61 while being loosely fitted to the guide tube portion 627, and the adhesive layer 671 is disposed inside the sleeve. Is formed.

  In this embodiment, as shown in FIG. 12, the sleeve 665 is positioned on the base side of the guide tube portion 627, and in this state, the end plate 61 and the side member 62 are connected by the fastening bolts 64, thereby Conclude. Even in this case, a gap K is formed between the end face of the side member 62, that is, the tip face of the guide tube portion 627 and the end plate 61, and the cell stacking is performed with the gap K remaining as described above. The body 50 is fastened. After the fastening, the sleeve 665 is slid in the direction of the arrow X shown in FIG. 12 to form a gap around the axis of the bolt shaft 644, and epoxy adhesive is injected and filled into the gap from the slit 666. Thus, an adhesive layer 671 is formed in the slit.

  Even in this embodiment, when the cell stack 50 is fastened, the end plate 61 and the side member 62 are fastened by the fastening bolts 64 with the gap K remaining, so that they do not come into contact with each other. Further, after the fastening is completed, the adhesive member layer 671 is formed in the space surrounded by the sleeve 665, and the side member 62 and the sleeve 665 are integrated. Therefore, the effects described above can also be achieved by this embodiment.

  The epoxy adhesive to be injected and filled into the sleeve 665 can be a composite material using carbon fiber or the like as a dispersion material (filler). By so doing, the strength of the cured adhesive layer 671 itself can be improved, and the strength of the sleeve 665 and the side member 62 as an integrated product can be increased. It is possible to further improve the impact resistance against external force applied from the direction intersecting with.

  This embodiment can be modified as follows. FIG. 13 is an enlarged cross-sectional view showing a state of connection between the side member 62 and the end plate 61 in a modified example using the sleeve 665 in a cross-sectional view in a state where the cell laminated body fastening is completed. In this modification, the end plate 61 includes a counterbore hole 615 on the side member 62 side. The sleeve 665 enters the counterbore hole 615 of the end plate 61 while loosely fitting in the guide tube portion 627 of the side member 62, and surrounds the adhesive layer 671 therein. Fastening of the cell stack 50 in this modification is performed with the sleeve 665 positioned on the base side of the guide tube portion 627 as described with reference to FIG. 12, and after the fastening, the sleeve 665 is inserted into the counterbore hole 615. The adhesive layer 671 is formed by fitting. In this modification, the end plate 61 and the side member 62 are more reliably integrated with each other by the sleeve 665 and the adhesive layer 671 hardened therein, so that the stacking direction of the cell stack 50 with respect to the fuel cell 10 is increased. It is possible to further improve the impact resistance against external force applied from the direction intersecting with. Even in this modification, it is more preferable that the epoxy adhesive is a composite material using carbon fiber or the like as a dispersion material (filler).

  As mentioned above, although the embodiment of the present invention has been described in the embodiments, the present invention is not limited to the above-described embodiments and modifications, and can be implemented in various modes without departing from the gist thereof. Is possible. For example, in the above-described embodiment, the spacer 660 is a two-piece member or a member having a slit, but a spacer that has only a through hole and is thinner than the gap K is used as the spacer of the fastening bolt 64. The cell stack 50 can be fastened by loosely fitting the bolt shaft 644.

  Further, when the cell stack 50 is fastened between the side member 62 and the end plate 61, the male screw portion 646 of the fastening bolt 64 is screwed into the female screw hole 626 on the side member end surface. . That is, after a so-called cut bolt shaft is screwed into the female screw hole 626 of the side member 62, the bolt shaft is protruded from the end face of the side member to penetrate the end plate 61. In addition, a nut can be screwed onto the front end side of the bolt shaft outside the end plate 61. Alternatively, the bolt shaft itself may be cut and formed on the end surface of the side member 62, and a nut may be screwed onto the tip side of the bolt shaft.

1 is a perspective view showing an overall configuration of a fuel cell 10 as an embodiment of the present invention. FIG. 2 is an exploded perspective view showing an essential part of the overall configuration of the fuel cell 10 in an exploded manner. It is sectional drawing which shows the cross section which cut | disconnected the fuel cell 10 with the fastening location in the AA cross section of FIG. 3 is an explanatory diagram showing a detailed configuration of a cell stack 50. FIG. It is an expanded sectional view which expands and shows a mode that the end plate 61 and the side member 62 which oppose were connected with the fastening bolt 64 and the filling joint part 66. It is explanatory drawing which decomposes | disassembles and shows the mode of a connection with the end plate 61 and the side member 62 by sectional view. It is explanatory drawing which shows the mode of the connection of the end plate 61 and the side member 62 by a perspective view. FIG. 5 is an explanatory diagram for explaining a procedure for fastening the cell stack 50. FIG. 3 is an exploded perspective view corresponding to FIG. 2 and showing an exploded view of the main part of the overall configuration of the fuel cell 10 of another embodiment. FIG. 8 is an explanatory view showing a perspective view of the connection between the end plate 61 and the side member 62 when the spacer 663 is used, corresponding to FIG. 7. It is an expanded sectional view expanding and showing the state of connection of side member 62 and end plate 61 in another example in the state where cell layered product conclusion was completed. It is explanatory drawing which shows the mode of the connection of the side member 62 and the end plate 61 at the time of the cell laminated body fastening in this Example by a perspective view. It is an expanded sectional view which expands and shows the mode of connection of side member 62 and end plate 61 in the modification using sleeve 665 in the state where cell layered product conclusion was completed. It is explanatory drawing for demonstrating the fastening structure conventionally employ | adopted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cell 50 ... Cell laminated body 52 ... Side member 60 ... Fastening mechanism 61, 63 ... End plate 62 ... Side member 64 ... Fastening bolt 66 ... Filling joint part 110 ... Insulator 120 ... Terminal 200 ... Separator 300 ... Power generation plate 510 ... restraint sheet 614 ... through hole 615 ... counterbore hole 618 ... through hole 624 ... passage hole 626 ... female screw hole 627 ... guide cylinder part 642 ... bolt head 644 ... bolt shaft 646 ... male screw part 660 ... spacer 661 ... through hole 663 ... Spacer 664 ... Slit 665 ... Sleeve 666 ... Slit 670 ... Adhesive layer 671 ... Adhesive layer K ... Gap SC ... Container

Claims (10)

A fuel cell that generates electricity electrochemically using a reaction gas,
A cell stack comprising a plurality of stacked fuel cells; and
A pair of end plates in contact with the cell stack at both ends in the stacking direction in which the plurality of fuel cells in the cell stack are stacked;
A shaft-shaped side member that is disposed between the pair of end plates along the stacking direction and is shorter than the stacking direction length of the cell stack,
A bolt shaft that protrudes from the end surface of the side member along the stacking direction and penetrates the end plate is provided, and the bolt shaft is screwed into a female screw hole into which the bolt shaft is screwed, so that the end plate and the side A fastening bolt portion for fastening the member;
A fuel cell comprising: a filling base material which is filled and hardened so as to surround the bolt shaft so as to surround the gap between the short side member and the end plate.   2. The fuel cell according to claim 1, wherein the fastening bolt portion is a fastening bolt having the bolt shaft that is screwed into the female screw hole that the side member has at both ends of the shaft. The fuel cell according to claim 1 or 2, wherein
The filling substrate is
A spacer interposed between the end surface of the side member and the end plate in the gap;
A fuel cell comprising: an adhesive that fills and cures a gap between the spacer and the end surface of the side member and / or a gap between the spacer and the end plate. A method for producing a fuel cell comprising a cell laminate in which a plurality of fuel cells that are units of electrochemical power generation using a reaction gas are laminated,
The end plate is brought into contact with both ends of the fuel cell in the stacking direction of the cell stack,
Between the end plates at both ends of the cell laminate, a shaft-shaped side member shorter than the stacking direction length of the cell laminate is disposed,
The bolt shaft is tightened with a fastening bolt portion that projects from the end surface of the side member along the stacking direction and is screwed into a female screw hole into which the bolt shaft is screwed. Fastening the cell stack between the end plates leaving a gap between the short side members and the end plates;
A method of manufacturing a fuel cell, wherein the gap is filled with a filling substrate so as to surround the bolt shaft, and the filling substrate is cured.   The method of manufacturing a fuel cell according to claim 4, wherein the bolt shaft is tightened by the fastening bolt portion by tightening a fastening bolt having the bolt shaft in the female screw hole that the side member has at both ends of the shaft. A method for producing a fuel cell according to claim 4 or 5, wherein
When filling the gap with the filling substrate,
A spacer is interposed between the end surface of the side member in the gap and the end plate;
A method of manufacturing a fuel cell, wherein an adhesive is filled in the gap between the spacer and the end surface of the side member and / or the gap between the spacer and the end plate.   The method of manufacturing a fuel cell according to claim 6, wherein the spacer can be attached to the bolt shaft in the gap so as to surround the bolt shaft after the cell stack is fastened by the fastening bolt.   The fuel cell manufacturing method according to claim 7, wherein the spacer is formed by dividing a cylindrical body having a through hole having a diameter larger than an axial diameter of the bolt shaft in an axial direction of the through hole.   The fuel cell manufacturing method according to claim 7, wherein the spacer has a slit into which the bolt shaft is inserted.   The fuel cell manufacturing method according to claim 6, wherein the adhesive is a composite material in which a dispersion material is dispersed in a base material.

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