Fuel battery stack

Abstract

To easily and uniformly press a limiting member that limits a movement of a cell stack against the cell stack.SOLUTION: A fuel battery stack includes: a cell stacked body configured by stacking a plurality of power generation cells in a predetermined direction; a housing surrounding the cell stacked body; a limit member whose one end surface abuts against an outer surface of the cell stacked body through an opening provided in a side wall of the housing and limits a movement of the cell stacked body in a direction orthogonal to the predetermined direction; a support member provided to support the other end surface of the limit member and cover the opening; and a pressing member that presses the support member toward a surface of the side wall. The housing has an outer side wall outside the side wall and extending substantially parallel to the side wall at a predetermined distance from a surface of the side wall. The pressing member is interposed between the outer side wall and the support member such that the limit member applies a predetermined pressing force to the cell stack.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a fuel cell stack. [Background technology]

[0002] In recent years, technological developments have been made in fuel cells that contribute to energy efficiency in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. A known technology for fuel cell stacks used in this type of fuel cell is one in which an intervening layer is disposed between a cell stack and a case (see, for example, Patent Document 1). In Patent Document 1, a compression body is fastened to the case with bolts, thereby pressing the intervening layer via the compression body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6512118 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a configuration in which the intermediate layer is pressed by screwing in a bolt, as in the technology described in Patent Document 1, it is difficult to control the load when screwing in the bolt, and it is difficult to press the intermediate layer evenly. [Means for solving the problem]

[0005] A fuel cell stack according to one aspect of the present invention includes a cell stack formed by stacking a plurality of power-generating cells in a predetermined direction, a housing surrounding the cell stack, a limiting member having one end face abutting against the outer surface of the cell stack through an opening provided in a side wall of the housing and limiting movement of the cell stack in a direction perpendicular to the predetermined direction, a support member supporting the other end face of the limiting member and provided to cover the opening, and a pressing member pressing the support member toward the surface of the side wall. The housing has an outer side wall on the outside of the side wall that extends substantially parallel to the side wall at a predetermined distance from the surface of the side wall, and the pressing member is interposed between the outer side wall and the support member so that the limiting member applies a predetermined pressing force to the cell stack. [Effects of the Invention]

[0006] According to the present invention, the restricting member can be easily and uniformly pressed against the cell stack. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view schematically showing the overall configuration of a fuel cell stack according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] Enlarged view of part IV in Figure 2. [Figure 5A] FIG. 5 is a front view of a shim included in the support of FIG. 4 . [Figure 5B] FIG. 5B is a diagram showing a modification of FIG. 5A. [Figure 6A] 5A to 5C are diagrams illustrating a procedure for attaching the restricting member shown in FIG. 4. [Figure 6B] 6B is a diagram illustrating the procedure for attaching the restricting member following FIG. 6A. [Figure 6C] 6B is a diagram illustrating the procedure for attaching the restricting member. FIG. [Figure 7] 5C is a diagram illustrating the configuration of a support portion when the shim of FIG. 5B is used. FIG. [Figure 8] FIG. 5 is a diagram showing a modification of FIG. 4. [Figure 9A]9A to 9C are diagrams illustrating the procedure for attaching the restricting member shown in FIG. 8. [Figure 9B] 9B is a diagram illustrating the procedure for attaching the restricting member following FIG. 9A. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 9B. A fuel cell stack according to an embodiment of the present invention constitutes a main element of a fuel cell. The fuel cell is mounted, for example, in a vehicle and can generate electric power for driving the vehicle. The fuel cell can also be mounted in mobile objects other than vehicles, such as aircraft and ships, robots, and various industrial machines.

[0009] FIG. 1 is a perspective view showing a schematic overall configuration of a fuel cell stack 100 according to an embodiment of the present invention. For convenience, the three mutually orthogonal axial directions 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 in accordance with 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. The front-rear direction in FIG. 1 is the stacking direction of the fuel cell stack 100, and when assembling the fuel cell stack 100, the stacking direction is aligned with the direction of gravity.

[0010] 1, the fuel cell stack 100 has a cell stack 10, end units 40 arranged at both front and rear ends of the cell stack 10, and a case 30 arranged around the cell stack 10, and has a generally rectangular parallelepiped shape as a whole. The length of the fuel cell stack 100 in the left-right direction is longer than the length in the up-down direction.

[0011] The case 30 has four generally rectangular side walls 300 that face the top, left, bottom, and right sides of the cell stack 10. These four side walls 300 form a generally box-shaped storage space SP0 with open front and rear sides. The case 30 is made of a metal such as aluminum or iron. The end unit 40 includes a conductive terminal plate, an insulating insulator that is arranged inside the end plate in the front-to-rear direction, and a metal end plate that is arranged on both sides of the insulator in the front-to-rear direction.

[0012] Part A of FIG. 1 shows a side wall 300 of the case 30 with a portion cut away. As shown in part A of FIG. 1, the cell stack 10 has a plurality of power-generating cells 1 (for convenience, only a single power-generating cell 1 is shown) arranged in the storage space SP0. The power-generating cell 1 has a unitized electrode assembly (UEA) 2 having a membrane electrode assembly (MEA) including an electrolyte membrane and electrodes, and separators 3 arranged on both the front and rear sides of the unitized electrode assembly 2 and sandwiching the unitized electrode assembly 2. The unitized electrode assemblies 2 and the separators 3 are arranged alternately in the front-to-rear direction. The unitized electrode assemblies 2 can also be called membrane electrode structures.

[0013] The separator 3 has a pair of front and rear metal thin plates with a corrugated cross section, and is integrally formed by joining the outer peripheries of the pair of thin plates. Separator 3 is made of a conductive material with excellent corrosion resistance, such as titanium, titanium alloy, or stainless steel. The pair of thin plates (front plate, rear plate) are formed into an uneven shape by press molding or the like to form a gas flow path between them and the integrated electrode assembly 2. More specifically, an anode flow path through which fuel gas containing hydrogen flows is formed between the integrated electrode assembly 2 and the rear plate. A cathode flow path through which oxidant gas containing oxygen flows is formed between the integrated electrode assembly 2 and the front plate. A cooling flow path through which a coolant (e.g., water) flows is formed between the pair of thin plates.

[0014] The integrated electrode assembly 2 includes a membrane electrode assembly and a resin frame that supports the periphery of the membrane electrode assembly. The membrane electrode assembly includes 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. The electrolyte membrane is, for example, a solid polymer electrolyte membrane. The anode electrode is an electrode catalyst layer formed on the front surface of the electrolyte membrane and serves as a reaction field for electrode reactions. A gas diffusion layer that diffuses and supplies reactant gases is provided on the front surface of the electrode catalyst layer. The cathode electrode is an electrode catalyst layer formed on the rear surface of the electrolyte membrane and serves as a reaction field for electrode reactions. A gas diffusion layer that diffuses and supplies reactant gases is provided on the rear surface of the electrode catalyst layer.

[0015] At the anode electrode, fuel gas (hydrogen) supplied via the anode flow channel and gas diffusion layer is ionized by the action of a catalyst and moves through the electrolyte membrane 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, oxidant gas (oxygen) supplied via the cathode flow channel and gas diffusion layer reacts with hydrogen ions introduced from the anode electrode and electrons transferred from the anode electrode, producing water. The produced water provides an appropriate humidity to the electrolyte membrane, and excess water is discharged outside the integrated electrode assembly 2.

[0016] Through holes 401 to 406 are opened in the rear end unit 40. Fuel gas is supplied to the inside of the cell stack 10 through through hole 401, oxidant gas is supplied through through hole 404, and a coolant is supplied through through hole 405. From the fuel cell stack 100, fuel gas is discharged through through hole 406, oxidant gas is discharged through through hole 403, and the coolant is discharged through through hole 402.

[0017] Although not shown in the figure, through holes are opened in each integrated electrode assembly 2 and separator 3 so as to communicate with the through holes 401 to 406. Via the through holes, fuel gas is supplied to the anode flow path, oxidant gas is supplied to the cathode flow path, and cooling medium is supplied to the cooling flow path of each power generation cell 1. Also, via the through holes, fuel gas is discharged from the anode flow path, oxidant gas is discharged from the cathode flow path, and cooling medium is discharged from the cooling flow path.

[0018] The fuel cell stack 100 is assembled, for example, in the following manner. First, one (e.g., the rear) end unit 40 is placed on the top surface of an assembly table. Next, the case 30 is placed on the top surface of this end unit 40, and the end unit 40 is fastened to one end (lower end) of the case 30 using bolts. Furthermore, a plurality of power generating cells 1 are accommodated in the storage space SP0 inside the case through the opening in the top surface of the case 30, and a predetermined number of power generating cells 1 are stacked. At this time, the power generating cells 1 are stacked while being positioned relative to the case 30 by guide members (not shown) that are provided on the inner wall surface of the case 30 and extend in the front-to-rear direction.

[0019] Once a predetermined number of power-generating cells 1 have been stacked, the other (e.g., front) end unit 40 is mounted, and a pressurizing machine is used to apply pressure to the entire stack from above. When the upper end unit 40 comes into contact with the other end (top end) of the case 30 due to the application of pressure, the end unit 40 and the other end of the case 30 are fastened together using bolts. This completes the assembly of the fuel cell stack 100. When the fuel cell stack 100 is assembled, the cell stack 10 is held in a state where a predetermined compressive load is applied.

[0020] When such a fuel cell stack 100 is mounted on a vehicle, an inertial force acts on the cell stack 10 in accordance with the acceleration acting on the vehicle. For example, when the stacking direction is the left-right direction of the vehicle, if acceleration in the front-rear direction acts on the vehicle when accelerating or decelerating, an inertial force acts on the cell stack 10 in a direction perpendicular to the stacking direction. Also, when the stacking direction is the front-rear direction of the vehicle, if lateral acceleration in the front-rear direction acts on the vehicle when turning, an inertial force acts on the cell stack 10 in a direction perpendicular to the stacking direction.

[0021] In this way, an inertial force acts on the cell stack 10 during normal vehicle operation, but this is not limited to this. An inertial force also acts on the cell stack 10 when an external impact force acts on the vehicle. For example, when the stacking direction is in the left-right direction of the vehicle, if an impact is applied from the front or rear by an object external to the vehicle (e.g., another vehicle), an inertial force acts on the cell stack 10 in a direction perpendicular to the stacking direction. Furthermore, when the stacking direction is in the front-to-rear direction of the vehicle, if an impact is applied from the right or left by an object external to the vehicle (e.g., another vehicle), an inertial force acts on the cell stack 10 in a direction perpendicular to the stacking direction.

[0022] When an inertial force acts on the cell stack 10 in a direction perpendicular to the stacking direction, the center of the cell stack 10 in the stacking direction is deformed in a bow shape. At this time, a shear force acts on the stacking surface of the cell stack 10, which may cause misalignment of the stacking surface of the cell stack 10. To prevent such deformation and misalignment of the cell stack 10 in the direction perpendicular to the stacking direction, a limiting member is provided in the fuel cell stack 100 according to this embodiment.

[0023] 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. Note that in FIGS. 2 and 3, only the outer edge shape of the cell stack 10 is shown, and the individual power-generating cells 1 (integrated electrode assemblies 2 and separators 3) are not shown. Point P in FIG. 2 is the center point of the cell stack 10 in the left-right direction and the top-bottom direction, and is referred to as the center point. Hereinafter, the side toward center point P will be referred to as the inside, and the side away from center point P will be referred to as the outside. As shown in FIG. 2, limiting members 50 are provided at four locations around the cell stack 10.

[0024] More specifically, the restricting members 50 are provided facing the left-right center of the upper side wall 300 (upper wall 301), the up-down center of the right side wall 300 (right wall 302), the left-right center of the lower side wall 300 (lower wall 303), and the up-down center of the left side wall 300 (left wall 304). The restricting members 50 are made of an insulating elastic material such as resin or rubber.

[0025] 3, the restricting member 50 has a generally rectangular parallelepiped shape and extends over a predetermined length in the front-to-rear direction at the center of each side wall 300 in the front-to-rear direction. The restricting members 50 may be provided near the four corners of the cell stack 10. For example, a pair of restricting members 50 may be provided corresponding to each corner of the cell stack 10, sandwiching the corners.

[0026] The multiple limiting members 50 are each supported by the case 30 and have the functions of preventing displacement due to inertial forces of the power generating cells 1, receiving external impacts, and absorbing impacts. The configurations of the multiple limiting members 50 and the configurations of the multiple support parts 55 that support the limiting members 50 from the case 30 are identical to one another.

[0027] 4 is an enlarged view of portion IV in FIG. 2. As shown in FIG. 4, an outer sidewall 310 extends generally parallel to the sidewall 300 on the outside of the sidewall 300 (the lower wall 303 in FIG. 4). A pair of connecting portions 315 extend generally perpendicular to the outer sidewall 310 from both ends of the outer sidewall 310 in the width direction (the left-right direction in FIG. 4). Tips of the pair of connecting portions 315 are connected to the outer surface of the sidewall 300. The connecting portions 315 and the sidewall 300 are joined by, for example, welding. As a result, a generally box-shaped outer space SP1 that is elongated in the front-rear direction and has a predetermined width W0 and height L0 is formed between the sidewall 300, the outer sidewall 310, and the pair of connecting portions 315.

[0028] 3, a rear end wall 316 is provided on the rear end surface of the outer sidewall 310 so as to cover the rear end of the outer space SP1. An end of the rear end wall 316 is connected to the surface of the sidewall 300 by, for example, welding, thereby closing the rear end opening of the outer space SP1. A front end wall 317 is detachably attached to the front end surface of the outer sidewall 310 by, for example, bolts, thereby closing a front end opening 317a of the outer space SP1.

[0029] As shown in Fig. 4, the side wall 300 has a generally rectangular opening 305 that is elongated in the front-rear direction and is located in the center of the outer space SP1 in the left-right direction. The width W1 of the opening 305 is narrower than the width W0 of the outer space SP1 and wider than the width W2 of the restricting member 50. The outer side wall 310 has a generally rectangular outer opening 311 that is elongated in the front-rear direction and is located in the center of the left-right direction. The width W3 of the outer opening 311 is narrower than the width W0 of the outer space SP1 and is the same as the width W1 of the opening 305. Note that the width W3 of the outer opening 311 may be wider or narrower than the width W1 of the opening 305.

[0030] A flat support plate 56 having a predetermined thickness is accommodated in the outer space SP1 via the front end opening 317a (FIG. 3). The width W4 of the support plate 56 is narrower than the width W0 of the outer space SP1 and wider than the widths W1 and W3 of the openings 305 and 311. The support plate 56 has an inner surface 561 facing the opening 305 and an outer surface 562 facing the outer opening 311.

[0031] The limiting member 50 is attached, for example, via an adhesive, to the center in the left-right direction of the inner surface 561. A sealing member 58 (for example, an O-ring) having a substantially rectangular frame shape is attached to the inner surface 561 so as to surround the limiting member 50. A height L1 from the outer surface 562 of the support plate 56 to the inner end face of the limiting member 50 is shorter than a height L0 of the outer space SP1.

[0032] A shim 57 of a predetermined thickness is inserted between the outer surface 562 of the support plate 56 and the outer side wall 310 through the front end opening 317a of the outer side wall 310. The thickness of the shim 57 is equal to or approximately equal to the height L0 of the outer space SP1 minus the thickness of the support plate 56.

[0033] Fig. 5A is a front view of shim 57. As shown in Fig. 5A, shim 57 has a pair of vertical plate portions 571 extending substantially parallel to each other and a horizontal plate portion 572 connecting the ends of vertical plate portions 571, and has a substantially U-shape overall. Width W5 of shim 57 is the same as width W4 (Fig. 4) of support plate 56.

[0034] 4 shows a state in which the limiting member 50 is supported by the support portion 55. The support plate 56 is held in contact with the outer surface of the side wall 300 in the outer space SP1 by inserting a shim 57 between the support plate 56 and the outer side wall 310. Because the shim 57 has a pair of vertical plate portions 571, 571, when the shim 57 is inserted, a region AR1 in the left-right center of the outer surface 562 of the support plate 56, i.e., the region AR1 between the pair of vertical plate portions 571, 571, is exposed to the outside.

[0035] When the shim 57 is inserted between the support plate 56 and the outer side wall 310, the sealing member 58 is crushed, sealing the gap between the outer surface of the side wall 300 and the support plate 56. At this time, the inner end face of the restricting member 50 abuts against the outer surface of the cell stack 10, thereby restricting the movement of the cell stack 10.

[0036] 1 (e.g., rearward) is aligned with the direction of gravity, and the fuel cell stack 100 is assembled in an upright position, and then the restricting member 50 is attached from the outside of the fuel cell stack 100. The restricting member 50 is attached, for example, as follows.

[0037] First, as shown in Fig. 6A, the limiting member 50 and the seal member 58 are adhered to the inner surface 561 of the support plate 56 to form the limiting member unit 51. Next, the limiting member unit 51 is inserted from above into the outer space SP1 through the front end opening 317a (Fig. 3) at the top of the outer side wall 310. At this time, the lower end of the limiting member unit 51 abuts against the rear end wall 316 (Fig. 3), restricting the downward movement of the limiting member unit 51.

[0038] Next, a cylinder is used to push the limiting member unit 51 toward the cell stack 10. More specifically, as shown in Fig. 6B, a frame 420 is attached to the side wall 300 so as to cover the outside of the outer side wall 310. A telescopic cylinder 421 (e.g., a pneumatic cylinder) is fixed to the frame 420 in advance, and a thin plate 422 that is elongated in the vertical direction is fixed to the tip of the cylinder 421.

[0039] Plate 422 is brought into contact with area AR1 of outer surface 562 of support plate 56 through outer opening 311 of outer sidewall 310. In this state, support plate 56 is pushed inward as shown by the arrows in FIG. 6B while squeezing seal member 58 until inner surface 561 of support plate 56 comes into contact with the outer surface of sidewall 300. By using cylinder 421, it is possible to apply a pushing force evenly to the elongated support plate 56.

[0040] When the support plate 56 abuts against the side wall 300, as shown in FIG. 6C , the shim 57 is inserted between the support plate 56 and the outer side wall 310 through the front end opening 317a at the top of the outer side wall 310. That is, the shim 57 is inserted with the horizontal plate portion 572 facing upward. The lower end of the shim 57 abuts against the rear end wall 316 of the outer side wall 310. As a result, the limiting member 50 is held in a state pressed against the cell stack 10 via the shim 57 and the support plate 56.

[0041] Next, the frame 420 is removed from the side wall 300. Furthermore, the front end wall 317 is fastened to the front end surface of the outer side wall 310 with bolts. This confines the support plate 56 and the shim 57 in the outer space SP1. This completes the installation of the limiting member 50 to the support part 55.

[0042] 5A, the shim 57 is configured to have a substantially U-shape, but the shape of the shim 57 is not limited to this. For example, as shown in FIG. 5B, the shim 57 may be configured with a pair of vertical plate portions 571. In this case, as shown in FIG. 7, for example, a cover 59 is attached to the outer side wall 310 via bolts (not shown). The cover 59 has a protrusion 591 that protrudes inward, and the protrusion 591 is inserted between the pair of vertical plate portions 571 through the outer opening 311 of the outer side wall 310. This makes it possible to regulate the position of the pair of vertical plate portions 571.

[0043] Fig. 8 is a diagram showing another example of the support portion 55 (a modified example of Fig. 4). In Fig. 8, unlike Fig. 4, a cylinder 421 is not used, but a wedge member 61 is used to push the restricting member 50 toward the cell stack 10. The configuration of Fig. 8 will be described below.

[0044] As shown in Fig. 8, a connection portion 315 connecting the side wall 300 and the outer side wall 310 of the case 30 is provided so as to surround three sides of the outer side wall 310. Therefore, an outer space SP1 between the side wall 300 and the outer side wall 310 is open only on one side of the outer side wall 310 (the right side in Fig. 8). A cover 62 having a generally L-shaped cross section is attached to an end of the outer side wall 310 so as to close the opening 310a. The cover 62 is attached to the side wall 300 and the outer side wall 310 via a seal member 63, and the entire periphery of the opening 310a is sealed by the seal member 63.

[0045] As in FIG. 4, the limiting member 50 is bonded in advance to an inner surface 561 of a support plate 56. The plate thickness of the support plate 56 is thicker than that of FIG. 4, and a tapered surface 563 is formed on an outer surface 562 of the support plate 56 so that the plate thickness gradually increases from the opening 310a toward the back of the outer space SP1. The wedge member 61 has an inner surface 611 that abuts against the support plate 56 and an outer surface 612 that abuts against the outer sidewall 310. The inner surface 611 is provided with a tapered surface 613 that has an inclination angle corresponding to the tapered surface 563, and the tapered surfaces 563, 613 abut against each other.

[0046] The limiting member 50 in FIG. 8 is temporarily fixed to the side wall 300 after fastening the case 30 to one (for example, rear) end unit 40 and before stacking multiple power generating cells 1 in the case 30. Specifically, first, the support plate 56 is inserted from the side (the right in FIG. 8) into the outer space SP1 through the opening 310a. Next, the limiting member 50 is bonded to the inner surface 561 of the support plate 56 through the opening 305 from inside the side wall 300. This forms a limiting member unit 51 in which the limiting member 50 and the support plate 56 are integrated.

[0047] Next, as shown in FIG. 9A , a jig 410 is attached to the end of the outer sidewall 310. The jig 410 is provided with a recess 411 into which the end of the support plate 56 fits. This holds the limiting member unit 51 with the outer surface 562 of the support plate 56 abutting against the outer sidewall 310, and the limiting member 50 is retracted to the outside. In this state, the power generating cells 1 are stacked, and further, pressure is applied from above via the end unit 40. By retracting the limiting member 50 to the outside, a gap GP1 of a predetermined distance is provided between the limiting member 50 and the cell stack 10. This allows multiple power generating cells 1 to be easily stacked inside the case 30 without interference with the limiting member 50.

[0048] Next, as shown in FIG. 9B , jig 410 is removed, and wedge member 61 is inserted into outer space SP1 through opening 310a. Then, tapered surface 563 of support plate 56 and tapered surface 613 of wedge member 61 are brought into contact with each other. Thereafter, the end of wedge member 61 is struck with a hammer or the like to push wedge member 61 in the direction of arrow A. This moves limiting member 50 inward via support plate 56. By using wedge member 61, it is possible to apply a uniform pushing force to elongated support plate 56.

[0049] As shown in Fig. 8, the wedge member 61 is pushed in until the inner surface 561 of the support plate 56 abuts against the outer surface of the side wall 300. When the support plate 56 abuts against the side wall 300, the limiting member 50 abuts against the cell stack 10. Next, the cover 62 is attached to the side wall 300 and the outer side wall 310 via the sealing member 63. At this time, although not shown, a spacer is interposed in the left-right gap GP2 between the wedge member 61 and the cover 62. This allows the wedge member 61 to be fixed in the outer space SP1.

[0050] According to this embodiment, the following effects can be achieved. (1) A fuel cell stack 100 includes a cell stack 10 formed by stacking a plurality of power-generating cells 1 in a predetermined stacking direction (front-rear direction), a case 30 surrounding the cell stack 10, a limiting member 50 whose inner end face abuts against the outer surface of the cell stack 10 through an opening 305 formed in a side wall 300 of the case 30 and limits movement of the cell stack 10 in a direction perpendicular to the stacking direction, a support plate 56 that supports the outer end face of the limiting member 50 and is provided to cover the opening 305, and a shim 57 or wedge member 61 that presses the support plate 56 toward the surface of the side wall 300 (FIGS. 1, 4, and 8). The case 30 has an outer side wall 310 on the outside of the side wall 300 that extends substantially parallel to the side wall 300 and is spaced a predetermined distance (a predetermined height L0) from the surface of the side wall 300 (FIG. 4). A shim 57 or wedge member 61 is interposed between the outer sidewall 310 and the support plate 56 so that the restricting member 50 exerts a predetermined pressing force against the cell stack 10 (FIGS. 4 and 8).

[0051] In this way, the shim 57 or the wedge member 61 presses the limiting member 50 toward the cell stack 10 via the support plate 56, so that the elongated limiting member 50 can be pressed evenly. Therefore, the limiting member 50 comes into even close contact with the cell stack 10, and the limiting member 50 can function well as a positioning member for the cell stack 10, a load-bearing member, etc.

[0052] (2) An outer opening 311 is provided in the outer side wall 310 opposite the opening 305 (FIG. 4). The shim 57 has a pair of vertical plate portions 571, 571 provided to sandwich an area (predetermined area) AR1 of the support plate 56 that faces the outer opening 311 (FIGS. 5A and 5B). This allows the support plate 21 to be pressed from the outside by the cylinder 421 through the area AR1, and the shim 57 can be easily inserted from the outside into the gap created by the pressing of the cylinder 421.

[0053] (3) The support plate 56 has an inner surface 561 that abuts against the surface of the side wall 300, and an outer surface 562 opposite the inner surface 561 (FIG. 8). The outer surface 562 forms a tapered surface 563 that is inclined relative to the surface of the side wall 300 (FIG. 8). The wedge member 61 is configured in a wedge shape that is inserted between the outer surface 562 of the support plate 56 and the outer side wall 310 (FIG. 8). This makes it possible to evenly press the limiting member 50 against the cell stack 10 with a simple configuration that simply involves inserting the wedge member 61 from the outside, without using a cylinder 421.

[0054] (4) The fuel cell stack 100 further includes sealing members 58 and 63 (FIGS. 4 and 8) that prevent gas leakage from the opening 305. This allows for a configuration in which the restricting member 50 is pressed from the outside through the opening 305 without causing gas leakage.

[0055] The above embodiment can be modified in various ways. Some modifications will be described below. In the above embodiment, the limiting member 50 has a substantially rectangular parallelepiped shape. However, the limiting member may have any configuration as long as one end face abuts against the outer surface of the cell stack through an opening in the side wall of the case 30 as the housing and limits movement of the cell stack in a direction perpendicular to the predetermined stacking direction (predetermined direction). For example, the limiting member may have a substantially L-shape corresponding to a corner of the cell stack. In the above embodiment, the limiting member 50 is supported by a support plate 56. However, the configuration of the support member is not limited to the above, as long as it supports the other end face of the limiting member and covers the opening in the side wall.

[0056] In the above embodiment, the restricting member 50 is pressed toward the cell stack 10 by the shim 57 inserted between the support plate 56 and the outer sidewall 310, or by the wedge member 61 inserted between the support plate 56 and the outer sidewall 310, but the configuration of the pressing member is not limited to the above. In other words, the pressing member may have any configuration as long as it is interposed between the outer sidewall and the support member so as to apply a predetermined pressing force to the cell stack.

[0057] In the above embodiment (FIG. 4), the shim 57 is configured to have a pair of vertical plate portions 571 sandwiching the central region AR1 of the support plate 56. However, the configuration of the pair of pressing portions is not limited to the above, as long as they are arranged to sandwich a predetermined region of the support member. In the above embodiment (FIG. 8), the support plate 56 has an inner surface 561 (first surface) and an outer surface 562 (second surface), and a tapered surface 563 (inclined surface) is formed on the outer surface 562, and a wedge member 61 is inserted between the outer surface 562 and the outer sidewall 310. However, the configuration of the wedge-shaped pressing member is not limited to the above. In the above embodiment, the sealing members 58, 63 are provided around or outside the opening 305 of the sidewall 300 to prevent gas leakage from the opening 305. However, the configuration of the sealing member is not limited to the above.

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

[0059] 1 power generating cell, 10 cell stack, 30 case, 50 limiting member, 56 support plate, 57 shim, 58 sealing member, 61 wedge member, 63 sealing member, 100 fuel cell stack, 300 side wall, 305 opening, 310 outer side wall, 311 outer opening, 561 inner surface, 562 outer surface, 563 tapered surface, 571 vertical plate portion, AR1 region, L0 predetermined height

Claims

1. a cell stack formed by stacking a plurality of power generating cells in a predetermined direction; a housing that surrounds the cell stack; a limiting member having one end surface abutting against an outer surface of the cell stack through an opening provided in a side wall of the housing, the limiting member limiting movement of the cell stack in a direction perpendicular to the predetermined direction; a support member that supports the other end surface of the restricting member and is provided to cover the opening; a pressing member that presses the support member toward the surface of the side wall, the housing has an outer side wall extending substantially parallel to the side wall at a predetermined distance from the surface of the side wall, The fuel cell stack is characterized in that the pressing member is interposed between the outer side wall and the support member so that the limiting member applies a predetermined pressing force to the cell stack.

2. 2. The fuel cell stack according to claim 1, The outer sidewall has an outer opening facing the opening, The fuel cell stack, wherein the pressing member has a pair of pressing portions provided to sandwich a predetermined region of the support member facing the outer opening.

3. 2. The fuel cell stack according to claim 1, the support member has a first surface that abuts against the surface of the side wall and a second surface opposite to the first surface; the second surface forms an inclined surface inclined with respect to the surface of the side wall; The fuel cell stack, wherein the pressing member is configured in a wedge shape that is inserted between the second surface and the outer side wall.

4. 4. The fuel cell stack according to claim 1, The fuel cell stack further comprises a sealing member for preventing gas leakage from the opening.

Images