JP6389767B2 - Fuel cell stack - Google Patents

Description

  The present invention relates to a fuel cell stack, and more specifically, to a structure for allowing gas to flow through the fuel cell stack.

  A fuel cell is a power generator that generates power by a reaction between an anode gas and a cathode gas supplied to a battery cell. The anode gas is generally hydrogen gas, and the cathode gas is generally oxygen gas in the air. The fuel cell is provided with a supply path for supplying these gases to the battery cells, and a discharge path for discharging the remaining gas and water as a reaction product to the outside.

  The fuel cell stack is a part of the components of the fuel cell, and generally, a cell stack in which a plurality of plate-shaped battery cells (single cells) are stacked in the thickness direction, and the cell stack A pair of end plates sandwiching the body in the stacking direction, and a plurality of manifolds attached to the end plates. The cell stack has a plurality of flow holes for supplying gas to the single cell, discharging gas from the single cell, and circulating the cooling medium between the single cells, and one end plate A plurality of inlets and outlets respectively communicating with the plurality of flow holes are provided. An end plate having an inlet / outlet is called a connecting end plate. A plurality of cylindrical manifolds that respectively communicate with the plurality of entrances are attached to the communication end plate. Some manifolds communicate with a fuel supply unit such as a hydrogen tank to form an anode gas supply path. Some other manifolds communicate with the outside air to form a cathode gas supply path. The other part of the manifold communicates with a cooling medium supply unit that stores the cooling medium, and forms a cooling medium supply path. Still another part of the manifold communicates with the outside world to form various gas and / or water discharge paths from the fuel cell stack toward the outside world.

  In recent years, many uses have been proposed for fuel cells, and the fuel cells are required to be lighter and smaller. A single cell involved in power generation and an end plate that requires high pressure resistance to sandwich the single cell have a low degree of freedom in material and shape, but a manifold has a relatively high degree of freedom in material and shape. For this reason, a technique for reducing the size and weight of the fuel cell stack by using a resin manifold is proposed (see, for example, Patent Document 1).

  According to the fuel cell stack introduced in Patent Document 1, an inlet / outlet is provided in a metal connecting end plate, a resin manifold is inserted into the inlet / outlet, and a gap between the manifold and the connecting end plate is sealed with an O-ring. And the manifold is fixed to the connecting end plate while the manifold and the inlet / outlet are hermetically sealed by fastening the manifold to the connecting end plate with bolts.

JP 2010-262908 A

However, according to the technique introduced in Patent Document 1, O-rings, bolts, and the like for attaching the manifold to the connecting end plate are required, and it is difficult to reduce the number of parts of the fuel cell stack. In addition, a work space for fastening the manifold to the connecting end plate is required on the surface of the fuel cell stack, and the degree of freedom of the shape of the manifold is low. For example, when it is desired to reduce the size of the fuel cell stack by making the manifold curved, depending on the positional relationship between the manifold and the connecting end plate, a sufficient work space for fastening the bolts can be secured between the manifold and the end plate. There may not be. As a result, it may be difficult to reduce the size of the fuel cell stack.
This invention is made | formed in view of the said situation, and makes it a subject to provide the technique which can miniaturize a fuel cell stack.

The fuel cell stack of the present invention has a cell stack formed by laminating a plurality of plate-shaped single cells in the thickness direction, a pair of end plates sandwiching the cell stack in the stacking direction, and a cylindrical shape. A plurality of manifolds attached to a communication end plate that is one of a pair of end plates;
The cell stack has a plurality of flow holes serving as passages for fluid flowing through the single cell, and the connection end plate has a plurality of inlets and outlets that are in the form of through holes and communicate with the plurality of flow holes, respectively. Each manifold is attached to the doorway;
The manifold is made of a thermoplastic resin,
The connecting end plate includes an end plate body made of a high-strength material other than a thermoplastic resin, and a cover portion made of a thermoplastic resin that is formed into a cylindrical shape and is integrated with the end plate body to constitute an inner peripheral surface of the entrance / exit. Have
The manifold is fixed to the covering portion.

  The fuel cell stack of the present invention can be miniaturized.

1 is an exploded perspective view schematically showing a fuel cell stack of Example 1. FIG. FIG. 3 is an enlarged perspective view of a main part schematically showing a connection part in the fuel cell stack of Example 1. 2 is a cross-sectional view schematically showing a connection portion in the fuel cell stack of Example 1. FIG. 6 is a cross-sectional view schematically showing a connection part in a fuel cell stack of Example 2. FIG. 6 is a cross-sectional view schematically showing a connection portion in a fuel cell stack of Example 3. FIG. 6 is a cross-sectional view schematically showing a connection portion in a fuel cell stack of Example 4. FIG. 6 is a cross-sectional view schematically showing a connection portion in a fuel cell stack of Example 5. FIG. 10 is a cross-sectional view schematically showing a connection part in a fuel cell stack of Example 6. FIG. 10 is a cross-sectional view schematically showing a connection portion in a fuel cell stack of Example 7. FIG.

  Hereinafter, the fuel cell stack of the present invention will be described with specific examples. The fuel cell stack of the present invention includes a polymer electrolyte fuel cell (so-called PEFC), a phosphoric acid fuel cell (so-called PAFC), a molten carbonate fuel cell (so-called MCFC), and a solid oxide fuel cell (so-called SOFC). ) Etc., and can be embodied as a fuel cell stack for various types of fuel cells.

Example 1
Embodiment 1 of the present invention will be described below with reference to FIGS. Hereinafter, the terms “up”, “down”, “left”, “right”, “front”, and “rear” refer to “upper, lower, left, right, front, and rear” shown in FIG.
The fuel cell stack of Example 1 shown in FIG. 1 has a cell stack 1, a pair of end plates 5, and a plurality of manifolds 8. This fuel cell stack is accommodated in an unillustrated container. The storage container fastens and holds the pair of end plates 5 and the cell stack 1 sandwiched between the end plates 5 in the stacking direction of the cell stack 1. In addition, you may fasten and hold | maintain the pair of end plates 5 and the cell laminated body 1 clamped by this with fastening members, such as a tie rod, instead of a storage container.

  The cell stack 1 includes a cell portion 10, a pair of terminal members 15, and a pair of insulating members 16. The cell unit 10 is composed of a large number of single cells 11 stacked in the front-rear direction in FIG. The pair of terminal members 15 sandwich the cell portion 10 from the front and rear. The pair of insulating members 16 sandwich the pair of terminal members 15 from the front and rear. Although not shown, each single cell 11 has a flat plate shape, a membrane electrode assembly in which a cathode, an electrolyte membrane, and an anode are stacked, a pair of separators sandwiching each membrane electrode assembly in the stacking direction, and a pair of separators And an insulating material interposed therebetween. Further, a gasket (not shown) is interposed between the single cells 11, more specifically, between the separators of the adjacent single cells 1.

  The cell stack 1 is provided with six flow holes 20 (21 to 26). Each flow hole 20 is formed in each element such as the single cell 11 and the terminal member 15 constituting the cell stack 1 and extends in the thickness direction of the cell stack 1. Each flow hole 20 communicates with a flow groove (not shown) formed in each single cell 11 (more specifically, a separator) (not shown). For reference, the first flow hole 21 located at the upper left in FIG. 1 is a cathode gas supply port that communicates with a flow groove provided inside the cathode separator, that is, on the electrolyte membrane side. The 2nd circulation hole 22 located under the 1st circulation hole 21 is a coolant supply port connected to the circulation groove provided in the outside of each separator. The third flow hole 23 located below the second flow hole 22 is an anode gas discharge port that communicates with a flow groove provided inside the anode separator, that is, on the electrolyte membrane side. The 4th circulation hole 24 located in the upper right in FIG. 1 is an anode gas supply port connected to the circulation groove provided inside the above-mentioned anode side separator. The 5th circulation hole 25 located under the 4th circulation hole 24 is a coolant discharge port connected to the circulation groove provided in the outside of each above-mentioned separator. The sixth flow hole 26 located below the fifth flow hole 25 is a cathode gas discharge port that communicates with the flow groove provided inside the cathode separator. Air flows through the first flow hole 21, a cooling medium (LLC in the first embodiment) flows through the second flow hole 22 and the fifth flow hole 25, and passes through the third flow hole 23 and the fourth flow hole 24. Hydrogen gas circulates, and air and water generated by the battery reaction circulate in the sixth circulation hole 26. The third flow hole 23 and the fourth flow hole 24 through which hydrogen gas flows are smaller in diameter than the other flow holes 21, 22, 25, and 26, but each flow hole 20 has a rectangular cross section. It is the same. In addition, what is necessary is just to set suitably the shape of each circulation hole 20, a position, and the fluid to distribute | circulate according to the kind, application, etc. of a fuel cell.

  The cell stack 1 is sandwiched between a pair of end plates 5 in the stacking direction of the cell stack 1, that is, the thickness direction of each single cell 11. One end plate 5 is a connecting end plate 50 having an entrance and exit described later, and the other end plate 5 is a general end plate 58 having no entrance and exit. The connecting end plate 50 is located on the front side in FIG. 1, and the general end plate 58 is located on the rear side in FIG. The general end plate 58 is made of aluminum, and the connecting end plate 50 is made of polyphenylene sulfide (PPS) resin and aluminum as described later.

  The communication end plate 50 has six doorways at positions facing the first flow hole 21 to the sixth flow hole 26. The entrance facing the first circulation hole 21 is called a first entrance 51, the entrance facing the second circulation hole 22 is called a second entrance 52, and the entrance facing the third circulation hole 23 is called a third entrance 53. The inlet / outlet facing the fourth circulation hole 24 is called a fourth inlet / outlet 54, the inlet / outlet facing the fifth circulation hole 25 is called a fifth inlet / outlet 55, and the inlet / outlet facing the sixth circulation hole 26 is a sixth inlet / outlet 56. Call. The first inlet / outlet 51 to the sixth inlet / outlet 56 are through holes, and the inner peripheral surfaces of the first inlet / outlet 51 to the sixth inlet / outlet 56 are made of a thermoplastic resin.

  Specifically, the communication end plate 50 includes one end plate body 6 and six covering portions 7 (71 to 76). The end plate main body 6 is made of metal, has a substantially flat plate shape, and has six main body entrances / exits 60 (61 to 66) having a through hole shape. As shown in FIGS. 1 and 2, the rear end of each main body entrance / exit 60 has a substantially rectangular cross section, and the front end has a substantially circular cross section. Between the front end and the rear end, the cross-sectional shape of each main body entrance / exit 60 gradually changes. Each covering portion 7 is made of a thermoplastic resin and has a substantially cylindrical shape. Each covering portion 7 is disposed inside each corresponding main body entrance 60.

  As shown in FIGS. 2 and 3, each covering portion 7 includes a cylindrical covering main body portion 77 and a pair of hook portions 78 that are continuous with two axial ends of the covering main body portion 77 and have a hook shape. , 79 and a substantially cylindrical shape. The covering main body 77 covers the inner peripheral surface of the main body entrance / exit 60, and the pair of flange portions 78 and 79 are exposed on the surface of the connecting end plate 50. In other words, each of the covering portions 7 is formed in a cylindrical shape, covering the inner peripheral surface of the entrance / exit, and extending from the two ends of the covering main body 77 along the surface of the connection end plate 50. A pair of flanges 78 and 79 exposed on the surface of the plate 50. The outer diameters of the flange portions 78 and 79 are larger than the outer diameter of the covering main body portion 77 and the inner diameter of the main body entrance / exit 60. Accordingly, the flange portions 78 and 79 contribute to preventing the covering portion 7 from coming off from the connecting end plate 50. The flange 78 is located on the front side in FIG. 1, that is, on the manifold 8 side, which will be described later, and the flange 79 is located on the rear side in FIG. 1, that is, on the cell laminate 1 side. Hereinafter, a portion of the covering portion 7 located on the front side, that is, the manifold 8 side in FIG. 1 is referred to as a first covering end portion 7a, and a portion located on the rear side, ie, the cell stack side in FIG. Call it.

The outer peripheral surface of each covering main body 77 has a shape corresponding to the inner peripheral surface of each corresponding main body entrance / exit 60. The outer peripheral surface at the rear end of each covering main body 77 has a substantially rectangular cross section, and the outer peripheral surface at the front end has a substantially circular cross section. Between the front end and the rear end, the cross-sectional shape of the outer peripheral surface of each covering main body 77 gradually changes. The inner peripheral surface of each covering main body 77 has a shape along the outer peripheral surface of each covering main body 77. The channel cross section of the inner peripheral surface of the rear end portion of each covering main body 77 has a substantially rectangular cross section that substantially matches the channel cross section of each flow hole 20. Therefore, each covering main body 77 has a cylindrical shape in which one end side is substantially cylindrical and the other end side is substantially rectangular. The flow path cross section of the inner peripheral surface of the front end portion in each of the covering main body portions 77 is a substantially circular shape that substantially matches the flow path cross section of the first manifold connection end portion described later. Between the front end portion and the rear end portion, the flow path cross-sectional shape of the inner peripheral surface of each covering main body portion 77 gradually changes.
Each covering portion 7 is formed by an insert injection molding method using the end plate body 6 as an insert material.

As shown in FIGS. 1 to 3, manifolds 8 (81 to 86) made of thermoplastic resin are attached to the first inlet / outlet 51 to the sixth inlet / outlet 56, respectively. Hereinafter, the connection structure including the connection end plate 50 and the manifolds 81 to 86 is referred to as a connection portion 9 as necessary. The manifolds 81 to 86 are vibration welded to the first covering end portions 7 a of the covering portions 71 to 76 provided on the connecting end plate 50. The method for fixing the manifold 8 to the covering portion 7 is not limited to vibration welding, and may be, for example, hot plate welding or adhesion.
Each manifold 8 has a curved substantially cylindrical shape. Of the two end portions in the axial direction of each manifold 8, the one located on the rear side in FIG. 1, that is, on the covering portion 7 side is called the first manifold connection end portion 87, and the other is the second manifold connection end portion 88. Call. The first manifold side connecting end 87 has a flange shape. As described above, the flow passage cross section of the first manifold connection end portion 87 and the flow passage cross section of the first covering end portion 7a form a perfect circle that is substantially coincident with each other. The first manifold connecting end portion 87 and the first covering end portion 7a are vibration welded to each other.

The connecting end plate 50 in the fuel cell stack of the first embodiment includes a metal end plate body 6 and thermoplastic resin coatings 71 to 76, and the manifolds 81 to 86 are made of the corresponding thermoplastic resin. The cover portions 71 to 76 are fixed.
Since it is difficult to firmly fix the resin and the metal, in order to attach the resin manifold 8 to the metal connection end plate 50 as in the conventional fuel cell stack, there are many O-rings, bolts and the like. In addition, the shapes of the connecting end plate 50 and the manifold 8 are limited due to the mounting work. However, since the thermoplastic resins are easily fixed to each other by a method such as welding or adhesion, a thermoplastic resin manifold 8 is fixed to the thermoplastic resin coating portion 7 as in the fuel cell stack of the first embodiment. In this case, the manifold 8 can be easily attached to the connecting end plate 50 by a method such as welding or adhesion.
In addition, since a structure such as a bolt, an O-ring, or the like for fastening or a flange for fastening the bolt is not necessary, the fuel cell stack can be reduced in size.
Furthermore, it is not necessary to provide a space for bolt fastening work in the vicinity of the surface of the fuel cell stack, more specifically, in the vicinity of the connection portion 9. For this reason, the freedom degree of the shape of the manifold 8 increases, for example, the shape of the manifold 8 can also be made into the curved shape routed near the surface of the connection end plate 50. FIG. By doing so, the fuel cell including the fuel cell stack can be further reduced in size.
In addition, since the number of parts such as bolts is reduced and the number of assembly steps is reduced, there is an advantage that the manufacturing cost of the fuel cell stack and the fuel cell having the fuel cell stack is reduced.

  In the fuel cell stack of Example 1, the end plate body 6 in the connection end plate 50 is made of metal. However, the material of the end plate body 6 in the fuel cell stack of the present invention is not limited to metal, and is thermoplastic. What is necessary is just to consist of high-strength materials other than resin. Specifically, the “high-strength material other than the thermoplastic resin” is at least one selected from metal materials such as aluminum and stainless steel, sintered bodies such as ceramics, and fiber-reinforced thermosetting resin materials such as CFRP. Illustrated. Here, “high strength” refers to strength compared to the manifold 8 made of thermoplastic resin and the covering portion 7 made of thermoplastic resin. The end plate body 6 made of a material other than the thermoplastic resin and the manifold 8 made of the thermoplastic resin are hard to be firmly fixed. Therefore, even when the material of the end plate body 6 is other than metal, the portion fixed to the manifold 8 made of thermoplastic resin, that is, the covering portion 7 in the connecting end plate 50 is made of thermoplastic resin. As in Example 1, the manifold 8 can be easily attached to the communication end plate 50, the fuel cell stack can be downsized, and the fuel cell including the fuel cell stack can be further downsized. Note that the materials for the general end plate 58 and the connecting end plate 50 may be appropriately selected in consideration of strength, heat resistance, acid resistance, and insulation as necessary.

  In the first embodiment, the flow path cross section of the first manifold connection end portion 87 and the flow path cross section of the first covering end portion 7a have a substantially circular cross section. By doing in this way, there exists an advantage which can set freely the attachment direction of the manifold 8 with respect to the connection end plate 50 in the circumferential direction of the flow-path cross section in the 1st manifold connection end part 87 and the 1st coating | coated end part 7a. That is, in order to fix the first manifold connecting end 87 to the first covering end 7a, the first covering is made so that the flow path cross-sectional shape of both is substantially the same in the axial direction and the circumferential direction perpendicular to the axial direction. It is necessary to attach the first manifold connection end portion 87 to the end portion 7a. If the channel cross sections of the first manifold connecting end 87 and the first covering end 7a are substantially true circles, the first manifold connecting end 87 is at various angles in the circumferential direction with respect to the first covering end 7a. There is an advantage that can be attached. In Example 1, the first manifold connecting end portion 87 and the first covering end portion 7a both have a circular cross section of the cross section and are cylindrical, as shown in FIG. Thus, the marker 99 for positioning is provided on both outer peripheral surfaces.

  For example, if the fuel cell stack is for in-vehicle use, the bending direction of the manifold 8 with respect to the connection end plate 50 may be different for each vehicle type. However, if the flow path cross section of the first covering end portion 7a and the flow path cross section of the first manifold connection end portion 87 are substantially true circles, the same connection end plate 50 and manifold 8 can be used. The bending direction of the manifold 8 with respect to the connecting end plate 50 can be freely changed simply by arbitrarily changing the mounting angle of the manifold 8 in the circumferential direction. Therefore, in this case, there is an advantage that the fuel cell stack of the present invention can be used for various vehicles.

  In general, in the fuel cell stack, in order to secure a flow path area as large as possible, the flow path cross section of each flow hole 20 has a rectangular shape. On the other hand, it is considered that the cross section of the flow path of the manifold 8 and the pipe connected to the manifold 8 is preferably circular in order to reduce pressure loss. In the fuel cell stack of Example 1, the portion facing the flow hole 20 having a rectangular cross section in the covering portion 7, that is, the flow passage cross section of the second covering end portion 7b was rectangular. In addition, the portion of the covering portion 7 facing the manifold 8, that is, the flow passage cross section of the first covering end portion 7a, has a substantially perfect circle. And the flow path cross section of the part in the meantime was gradually changed from the rectangle to the perfect circle. By doing so, the flow passage 20 having a rectangular flow passage cross section and the manifold 8 having a true flow passage cross section can be smoothly continued by the covering portion 7, and the pressure loss of the gas flowing through the fuel cell stack is reduced. be able to.

  In the first embodiment, the flow passage cross-sectional shape of the main body inlet / outlet 60 in the end plate main body 6 is made a constant rectangular shape, the outer peripheral surface of the covering portion 7 is made a rectangular shape with a constant cross section, and only the flow passage cross-sectional shape of the covering portion is provided. Is gradually changed from a rectangle to a circle. By doing in this way, the ratio which the end plate main body 6 which is a metal part accounts in the connection end plate 50 can be made small, and it can contribute to the weight reduction of a fuel cell stack.

  Further, the main body entrance / exit 60 provided in the end plate main body 6 can be gradually changed from a rectangle to a true circle according to the cross-sectional shape of the flow path of the covering portion 7. In this case, the wall thickness of the thermoplastic resin coating portion 7 can be made constant, and unevenness of the inner peripheral surface of the coating portion 7 due to variations in molding shrinkage can be suppressed, so that turbulent flow is generated in the fluid passage of the fuel cell stack. And pressure loss in the fluid passage can be reduced.

  In the first embodiment, PPS is used as the thermoplastic resin used for the covering portion 7 of the connection end plate 50. However, the present invention is not limited to this. For example, an olefin resin such as PP or an aromatic nylon resin such as PA6T or PA9T is used. May be.

In the first embodiment, the covering portion 7 is formed integrally with the end plate body 6 by the insert injection molding method. However, the covering portion 7 is formed separately from the end plate body 6 and bonded to the end plate body 6 by a method such as adhesion. May be integrated. The molding method of the covering portion 7 is not limited to injection molding, and other molding methods such as blow molding may be used.
Although various methods can be used as the bonding method for bonding the thermoplastic resin coating portion 7 to the metal end plate body 6, the method described in Japanese Patent No. 5560565 or Japanese Patent No. 5234011 is adopted. preferable.

  As described in Japanese Patent No. 5560565, when a polar functional group is introduced on the surface of a metal member and an adhesive modifier is blended in the resin material, the polar functional group and the adhesive modifier are combined. By reacting with the adhesive functional group contained, the metal member and the resin member are fixed with high bonding strength. In the fuel cell stack of the present invention, a polar functional group is imparted to the surface of the end plate main body 6 as described above, and the above-described adhesive property modifier is blended as an adhesive for bonding the covering portion 7 and the end plate main body 6 together. If the resin material made is used, it is considered that the metal end plate body 6 and the thermoplastic resin covering portion 7 can be fixed with high bonding strength.

In order to bond the end plate main body 6 and the covering portion 7 based on the technique disclosed in Japanese Patent No. 5234011, a polar functional group is added to the surface of the metal end plate main body 6 and the covering portion 7 is used. It is considered that a resin material in which the above-mentioned adhesive property modifier is blended may be used as an adhesive for bonding the end plate body 6 to the end plate body 6. Alternatively, a method is also conceivable in which the above-mentioned adhesion modifier is blended with the raw material of the covering portion 7 and the surface-treated end plate body 6 and the covering portion 7 are welded. In any case, similarly to the above, it is considered that the metal end plate body 6 and the thermoplastic resin covering portion 7 can be fixed with high bonding strength.
Furthermore, when the end plate body 6 surface-treated by one of the two methods described above is used as an insert material and the covering portion 7 is insert-molded using a raw material blended with an adhesive modifier, it is made of metal. It is considered that an integrally molded product in which the end plate body 6 and the thermoplastic resin coating 7 are fixed with high bonding strength is obtained.

(Example 2)
The fuel cell stack of Example 2 is the same as the fuel cell stack of Example 1 except for the shape of the connection portion 9.
As shown in FIG. 4, in the fuel cell stack of Example 2, the flange portion 78 on the first covering end portion 7a side of the covering portion 7 has a larger diameter than the flange portion 79 on the second covering end portion 7b side. is there. Further, the peripheral portion 78 a of the flange portion 78 has a hook shape protruding toward the flange portion 79 along the axial direction of the covering portion 7. The peripheral edge 60 a of each main body entrance / exit 60 in the end plate main body 6 constitutes a ring-shaped groove 60 a corresponding to the peripheral edge 78 a of the flange 78. Therefore, it can be said that the end plate main body 6 and the flange portion 78 are engaged with each other inside the groove portion 60a. By forming the connecting portion 9 in such a shape, the covering portion 7 can be firmly integrated with the end plate body 6.
Further, in the fuel cell stack of the second embodiment, since the flange portion 78 has a large diameter, the fixing area between the flange portion 78 and the first manifold connection end portion 87 of the manifold 8 can be increased. There is also an advantage that the bonding strength with the plate 50 can be improved.

(Example 3)
The fuel cell stack of Example 3 is the same as the fuel cell stack of Example 1 except for the shape of the connection portion 9.
As shown in FIG. 5, in the fuel cell stack of Example 3, a plurality of through holes 60 b are provided in the peripheral edge of each main body entrance / exit 60 in the end plate main body 6. In the through hole 60b, a coupling wall 7c, which is a part of the covering portion 7 and extends in the axial direction of the covering portion 7, that is, in the thickness direction of the end plate body 6, enters. The coupling wall 7 c connects the peripheral edge of the flange 78 and the peripheral edge of the flange 79. In other words, the end plate main body 6 and the covering portion 7 are mechanically integrated, and the end plate main body 6 and the covering portion 7 are very firmly integrated.

(Example 4)
The fuel cell stack of Example 4 is the same as that of Example 1 except for the shape of the connection portion 9.
As shown in FIG. 6, in Example 4, the flow passage cross section of the first covering end portion 7 a and the flow passage cross section of the first manifold connection end portion 87 form a regular hexagonal shape. By setting the flow path cross-sectional shapes of the first covering end portion 7a and the first manifold connection end portion 87 in this way, the mounting direction of the first manifold connection end portion 87 with respect to the first covering end portion 7a is set to the flow path cross section. The direction can be changed in six directions rotated by 60 ° in the circumferential direction. Therefore, the bending direction of the manifold 8 with respect to the connection end plate 50 can be changed to six predetermined directions only by changing the mounting angle of the manifold 8 with respect to the connection end plate 50 in the circumferential direction. Therefore, also in this case, there is an advantage that the same fuel cell stack having the same connecting end plate 50 and the manifold 8 can be used for various applications.
The first covering end 7a and the first manifold connection end 87 each have a rectangular tube shape. For this reason, the operator can easily perceive the attachment direction of the first manifold connection end portion 87 with respect to the first covering end portion 7a by touch or vision. For this reason, according to the fuel cell stack of the fourth embodiment, there is an advantage that the mounting direction of the manifold 8 with respect to the connection end plate 50 can be easily positioned.
In Example 4, the flow passage cross section of the first covering end portion 7a and the flow passage cross section of the first manifold connection end portion 87 have a regular hexagonal shape that substantially coincides with each other. If so, the same effect as in the fourth embodiment can be obtained. In this case, in consideration of the versatility of the connecting end plate 50 and the manifold 8 and the positioning of both, the flow passage cross sections of the first covering end 7a and the first manifold connecting end 87 are regular pentagons to octagons. Preferably there is.

(Example 5)
The fuel cell stack of Example 5 is the same as the fuel cell stack of Example 1 except for the shape of the connection portion 9.
As shown in FIG. 7, in the fuel cell stack of Example 5, the covering portion 7 is inclined toward the curve direction of the manifold 8. By doing so, it is possible to omit the rising portion of the manifold 8, that is, the portion extending perpendicularly to the surface of the connecting end plate 50, while smoothly covering the covering portion 7 and the manifold 8. As a result, the manifold 8 can be brought closer to the connecting end plate 50, and the fuel cell stack can be further downsized.

(Example 6)
The fuel cell stack of Example 6 is the same as the fuel cell stack of Example 1 except for the shape of the connection portion 9.
As shown in FIG. 8, in the fuel cell stack of Example 6, the flange portion 78 in the covering portion 7 has a curved shape along the bending direction of the manifold 8 and protrudes from the end plate body 6 to the manifold 8 side. Yes. By doing so, the rising portion of the manifold 8 can be omitted while the covering portion 7 and the manifold 8 are smoothly continuous, and the manifold 8 can be brought closer to the connecting end plate 50. Further downsizing can be achieved.

(Example 7)
The fuel cell stack of Example 7 is the same as the fuel cell stack of Example 1 except for the shape of the connection portion 9.
As shown in FIG. 9, in the fuel cell stack of Example 7, the peripheral edge portion of each main body entrance / exit 60 in the end plate main body 6 is deeply depressed. The peripheral edge of each main body entrance / exit 60 is referred to as a depressed portion 60c. Since the flange portion 78 in the covering portion 7 has entered the depressed portion 60 c, the collar portion 78 is located at a position lower than the surface of the end plate body 6 on the manifold 8 side. That is, in Example 7, the thickness of the end plate body 6 is relatively thin at the peripheral edge of each body entrance / exit 60. Further, the axial length of the covering portion 7 is also relatively short. The manifold 8 is the same as that of the first embodiment, but the first manifold connection end portion 87 of the manifold 8 is fixed to the flange portion 78 on the back side of the depressed portion 60c. For this reason, the rising part of the manifold 8 is accommodated in the depression 60c. That is, also in the fuel cell stack of Example 7, the rising portion of the manifold 8 is substantially omitted. For this reason, also in the fuel cell stack of the seventh embodiment, the manifold 8 can be brought closer to the connecting end plate 50 while the covering portion 7 and the manifold 8 are smoothly continued, and thus the fuel cell stack can be further reduced in size. .

  In Examples 5 to 7, it can be said that the rising portion of the manifold 8, that is, the portion of the manifold 8 on the side of the connecting end plate 50 is configured by a part of the covering portion 7. As a result, the rising portion of the manifold 8 is substantially inserted into the communication end plate 50 and can be omitted from the manifold 8. Further, this makes it possible to bring the manifold 8 close to the connecting end plate 50, and to realize a reduction in the size of the fuel cell stack.

(Note 1)
The present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope not departing from the gist.
(Note 2)
The fuel cell stack of the present invention comprises:
A cell stack 1 in which a plurality of unit cells 11 having a plate shape are stacked in the thickness direction, a pair of end plates 5 sandwiching the cell stack 1 in the stacking direction, and a pair of end plates having a cylindrical shape A plurality of manifolds 8 (81 to 86) attached to a communication end plate 50 that is one of the five,
The cell stack 1 has a plurality of flow holes 20 (21 to 26) serving as passages for fluid flowing through the single cell 11, and the connection end plate 50 has a through-hole shape and a plurality of the flow holes 20. A plurality of inlets and outlets 51 to 56, each of which is connected to the inlet and outlet,
The manifold 8 is made of a thermoplastic resin,
The connecting end plate 50 is made of a high-strength material other than a thermoplastic resin, and is made of a thermoplastic resin that is formed in a cylindrical shape and is integrated with the end plate main body 6 to constitute an inner peripheral surface of the entrance / exit. Covering portion 7 (71-76),
The manifold 8 is fixed to the covering portion 7.
The fuel cell stack of the present invention preferably includes any one of the following (1) to (5), and preferably includes a plurality.
(1) The covering portion 7 includes a cylindrical covering main body portion 77 that covers the inner peripheral surface of the doorway, and a pair of eaves that extend from two ends of the covering main body portion 77 and are exposed on the surface of the connecting end plate 50. Parts 78 and 79.
(2) The manifold 8 is welded or bonded to the covering portion 7.
(3) Of the two end portions in the axial direction of the covering portion 7, the flow path cross section of the first covering end portion 7 a located on the manifold 8 side and the two end portions in the axial direction of the manifold 8 The flow path cross section of the first manifold connection end portion 87 located on the connection end plate 50 side forms a perfect circle corresponding to each other.
(4) The flow hole 20 has a rectangular cross section,
Of the two ends in the axial direction of the covering portion 7, the second covering end portion 7b located on the cell laminate 1 side has a shape corresponding to the flow path cross section of the flow hole 20,
The shape of the cross section of the flow path of the covering portion 7 is gradually changed from the second covering end portion 7b toward the first covering end portion 7a.
(5) The manifold 8 has a curved cylindrical shape.

1: Cell laminate 5: End plate 6: End plate body 7 (71-76): Covering portion 8 (81-86): Manifold 11: Single cell 20 (21-26): Flow hole 50: Contact end plate 51 -56: Entrance / exit port 77: Cover main body portion 78, 79: Eaves portion 7a: First cover end portion 7b: Second cover end portion 87: First manifold connection end portion

Claims (3)

One of the pair of end plates, a cell stack formed by laminating a plurality of plate-shaped single cells in the thickness direction, a pair of end plates sandwiching the cell stack in the stacking direction A plurality of manifolds attached to the communication end plate;
The cell stack has a plurality of flow holes serving as passages for fluid flowing through the single cell, and the connection end plate has a plurality of inlets and outlets that are in the form of through holes and communicate with the plurality of flow holes, respectively. Each manifold is attached to the doorway;
The manifold is made of a thermoplastic resin,
The connecting end plate includes an end plate body made of a high-strength material other than a thermoplastic resin, and a cover portion made of a thermoplastic resin that is formed into a cylindrical shape and is integrated with the end plate body to constitute an inner peripheral surface of the entrance / exit. Have
The manifold is welded or bonded to the covering portion and has a curved cylindrical shape,
Of the two end portions in the axial direction of the covering portion, the flow path section of the first covering end portion located on the manifold side, and among the two end portions in the axial direction of the manifold, located on the connecting end plate side. A fuel cell stack having a circular shape corresponding to the flow path cross section of the first manifold connection end .   The said covering part has a cylindrical covering main-body part which covers the inner peripheral surface of the said entrance, and a pair of eaves parts extended from the two end parts of the said covering main-body part, and being exposed to the surface of the said connection end plate, respectively. Item 2. The fuel cell stack according to Item 1. The flow hole has a rectangular cross section,
Of the two end portions in the axial direction of the covering portion, the second covering end portion located on the cell laminate side has a shape corresponding to the flow path cross section of the flow hole,
3. The fuel cell stack according to claim 1 , wherein a shape of a flow path cross section of the covering portion gradually changes from the second covering end portion toward the first covering end portion.

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