JP6341063B2 - Manufacturing method of fuel cell stack - Google Patents

Description

  The present invention relates to a method for manufacturing a fuel cell stack.

  A fuel cell body including a stack formed by stacking a plurality of fuel cell single cells along the stacking direction; a tension plate provided outside the outer peripheral surface of the fuel cell body along the stacking direction; and a fuel There has been disclosed a fuel cell stack including an intervening layer having a low friction characteristic, a buffer characteristic and an insulating characteristic, which is disposed between an outer peripheral surface of a battery main body and a tension plate (see, for example, Patent Document 1). Examples of the intervening layer include foamable resin and rubber.

JP 2003-203670 A

  Although the method for manufacturing the fuel cell stack of Patent Document 1 is not specifically described in Patent Document 1, an intervening layer is disposed on the outer peripheral surface of the fuel cell main body along the stacking direction, and the intervening layer is placed on the intervening layer. A method of arranging a tension plate on the surface can be considered. That is, there is a method in which intervening layers are arranged on the outer peripheral surface of the fuel cell main body, subsequently tension plates are arranged on the respective intervening layers, and then the tension plates are connected to each other. In this case, in order to surround the fuel cell main body with a plate-like tension plate, a member such as a gasket to be inserted between the tension plates and a bolt for connecting the tension plates to each other is necessary to ensure water tightness. Manufacturing costs increase and productivity decreases. As a result of investigations to cope with this, the inventors prepared a box-shaped case instead of the tension plate, and placed the fuel cell body with an intervening layer on the outer peripheral surface in the case, thereby improving water tightness. It was found that the manufacturing cost can be reduced and the productivity can be improved while securing the above. Here, in order to exhibit the function of the intervening layer, particularly the buffering characteristic, it is necessary to dispose the intervening layer in a compressed state between the outer peripheral surface of the fuel cell main body and the inner peripheral surface of the case. However, in the case where the fuel cell main body is housed in the case, it is extremely difficult to dispose the intervening layer in a compressed state between the outer peripheral surface of the fuel cell main body and the inner peripheral surface of the case. A technique that can appropriately dispose an intervening layer between the outer peripheral surface of the fuel cell main body and the inner peripheral surface of the case is desired.

  According to the present invention, a fuel cell main body including a stack formed by stacking a plurality of fuel cell single cells along the stacking direction, four side walls surrounding the fuel cell main body along the stacking direction, and at least A case in which the fuel cell main body is accommodated, and an intervening layer disposed between the fuel cell main body and the case and having a restoring force to return to the original dimensions when deformed A fuel cell stack manufacturing method comprising: an outer peripheral surface of the fuel cell main body along the stacking direction when the fuel cell main body is accommodated in the case; A step of disposing the intervening layer having a thickness larger than the distance from the inner peripheral surface of the side wall on each of the two opposing surfaces of the outer peripheral surface; and an interposition disposed on the two opposing surfaces Crushing with a roller from one end to the other end in the stacking direction of the intervening layer so that the thickness of the intervening layer is smaller than the distance, and before the thickness of the intervening layer swells to the distance, And a step of accommodating the fuel cell main body in the case through the opening while moving the case relative to the fuel cell main body.

  An intervening layer can be appropriately disposed between the outer peripheral surface of the fuel cell main body and the inner peripheral surface of the case.

It is sectional drawing of a fuel cell stack. It is sectional drawing of a fuel cell stack. It is sectional drawing which shows the manufacturing process of a fuel cell stack. It is sectional drawing which shows the manufacturing process of a fuel cell stack. It is sectional drawing which shows the manufacturing process of a fuel cell stack. It is the front view and side view which show the structural example of a compressor. It is sectional drawing which shows the manufacturing process of a fuel cell stack. It is sectional drawing which shows the manufacturing process of a fuel cell stack. It is sectional drawing which shows the manufacturing process of a fuel cell stack. It is sectional drawing which shows the manufacturing process of a fuel cell stack. It is sectional drawing which shows the manufacturing process of a fuel cell stack. It is a side view which shows the relationship of the thickness of the intervening layer in each manufacturing process. It is sectional drawing explaining the effect in the case of using a roller. It is sectional drawing explaining the problem when not using a roller. It is sectional drawing which shows the relationship of the thickness of an intervening layer before and behind crushing an intervening layer. It is sectional drawing which shows an example of the relationship between the intervening layer and a fuel cell single cell before and after crushing the intervening layer. It is sectional drawing which shows the case of another Example. It is a top view which shows the case of another Example. It is sectional drawing which shows the manufacturing process of the fuel cell stack of another Example. It is sectional drawing which shows the case of another Example. It is a top view which shows the case of another Example. It is sectional drawing which shows the manufacturing process of the fuel cell stack of another Example. It is sectional drawing of the fuel cell stack of another Example.

  The fuel cell stack A according to the example will be described. 1 and 2 are schematic sectional views of the fuel cell stack A. FIG. However, FIG. 1 is an E1-E1 sectional view of FIG. 2, and FIG. 2 is an E2-E2 sectional view of FIG. The fuel cell stack A includes a fuel cell main body 1, a case 2 in which the fuel cell main body 1 is accommodated, and an intervening layer 3 disposed between the fuel cell main body 1 and the case 2.

  The fuel cell body 1 is supplied with a fuel gas and an oxidant gas and generates electric power by an electrochemical reaction. The fuel cell main body 1 includes a stacked body 11, a terminal plate 12, an end plate 14, and an insulating plate 13. The stacked body 11 is formed by stacking a plurality of fuel cell single cells along the stacking direction S. The terminal plate 12 is disposed at both ends of the stacked body 11 in the stacking direction S. The end plate 14 is disposed outside the terminal plate 12 in the stacking direction S. The insulating plate 13 is disposed between the terminal plate 12 and the end plate 14. The terminal plate 12, the end plate 14, and the insulating plate 13 each have a rectangular shape when viewed in a cross section perpendicular to the stacking direction S. At that time, the terminal plate 12 and the insulating plate 13 have substantially the same size. On the other hand, the end plate 14 is approximately the same size as or slightly larger than the terminal plate 12 and the insulating plate 13. The terminal plate 12 and the end plate 14 are made of a conductive material, and the insulating plate 13 is made of an electrically insulating material.

  The case 2 accommodates the fuel cell body 1 in a compressed state and restrains the fuel cell body 1. The case 2 includes a case main body 22 and a lid plate 21. The case main body 22 can accommodate the fuel cell main body 1 therein. The case main body 22 is substantially a rectangular parallelepiped, has four side walls 22a and a bottom wall 22b surrounding the fuel cell main body 1 along the stacking direction S, and has an opening facing the bottom wall 22b. The width of the bottom surface inside the case body 22 is slightly larger than the cross section perpendicular to the stacking direction S of the fuel cell body 1. The length in the stacking direction S inside the case body 22, that is, the depth, is the same as or slightly longer than the length in the stacking direction S when the fuel cell body 1 is compressed in the stacking direction S. The lid plate 21 is a lid of the case body 22 and is fastened to the case body 22 by a fastening member (not shown). The case body 22 and the lid plate 21 are made of a metal such as stainless steel or aluminum.

  When the fuel cell main body 1 is accommodated in the case main body 22 and the lid plate 21 is closed, and the case main body 22 and the lid plate 21 are fastened by a fastening member, the fuel cell main body 1 is separated from the lid plate 21 and the case main body 22. The bottom wall 22b is restrained by being pushed inward in the stacking direction S from both sides. As a result, the end plates 14 and 14 on both sides of the fuel cell main body 1 approach each other in the stacking direction S. Therefore, the stacked body 11, the terminal plate 12, the insulating plate 13, and the end plate 14 are in close contact with each other in the stacking direction S. At this time, a gap of a distance D is formed between the outer peripheral surface 1a of the fuel cell main body 1 along the stacking direction S and the inner peripheral surface 2a of the side wall 22a of the case 2 facing the outer peripheral surface 1a. The intervening layer 3 is disposed in the gap.

  When the depth of the case body 22 is slightly longer than the length of the compressed fuel cell body 1 in the stacking direction S, for example, the bottom wall 22b is tightened from the outside of the bottom wall 22b of the case body 22 to tighten the bolt. The bolt projecting from the inside pushes the end plate 14 of the fuel cell main body 1 to restrain the fuel cell main body 1. In another embodiment (not shown), when the fuel cell main body 1 is accommodated in the case 2, the lid plate 21 and the end plate 14 in contact therewith are fastened by a fastening member, and the bottom wall 22 b of the case main body 22 and the end plate in contact therewith. 14 is fastened with a fastening member, whereby the case 2 and the fuel cell main body 1 are fastened.

  The lid plate 21, the terminal plate 12, the insulating plate 13 and the end plate 14 located at one end in the stacking direction S of the fuel cell stack A are connected to the lid plate 21, the terminal plate 12, the insulating plate 13 and the end plate 14 in the stacking direction S. And a plurality of flow paths (not shown) extending from the outside of the fuel cell stack A to the stacked body 11. In these flow passages, a supply path for supplying a fuel gas such as hydrogen to the stack 11, a discharge path for discharging the fuel gas from the stack 11, and a supply path for supplying an oxidant gas such as air to the stack 11 , A discharge path for discharging the oxidant gas from the stacked body 11, a supply path for supplying cooling water to the stacked body 11, and a discharge path for discharging cooling water from the stacked body 11.

  Each single fuel cell has an anode electrode and a cathode electrode (not shown), and the anode electrode is electrically connected to the cathode electrode of the fuel cell unit cell adjacent to one side, and the cathode electrode is adjacent to the other side. It is electrically connected to the anode electrode of the single fuel cell. The anode electrode at one end of the laminate 11 is electrically connected to one terminal plate 12, and the cathode electrode at the other end is electrically connected to the other terminal plate 12. The fuel cell unit cell generates electric power by an electrochemical reaction between the fuel gas and the oxidant gas supplied to the fuel cell unit cell. The electric power generated in the single fuel cell is taken out of the fuel cell stack A through a plurality of wires extending from the terminal plate 12 to the outside of the fuel cell stack A. The electric power extracted from the fuel cell stack A is supplied to, for example, an electric motor for driving a vehicle or a capacitor. The end plate 14 and the case 2 are grounded. Note that illustration of these electrical configurations is omitted.

  The intervening layer 3 is a member that absorbs an impact applied to the fuel cell main body 1, suppresses displacement of the fuel cell main body 1, and electrically insulates the fuel cell main body 1 and the case 2. The intervening layer 3 is formed between the fuel cell main body 1 and the case 2, that is, between the outer peripheral surface 1a of the fuel cell main body 1 along the stacking direction S and the inner peripheral surface 2a of the side wall 22a of the case 2 facing the outer peripheral surface 1a. It arrange | positions in between and is each arrange | positioned at two sets of two surfaces which face each other among the outer peripheral surfaces 1a. Further, when viewed in a cross section in the stacking direction S (for example, FIG. 1), the intervening layer 3 is provided from one end to the other end of the fuel cell main body 1 along the stacking direction S. On the other hand, when viewed in a cross section perpendicular to the stacking direction S (for example, FIG. 2), the intervening layer 3 is at least in the vicinity of the four corners Cn of the fuel cell body 1, that is, at least in the vicinity of the four corners of the case 2. Is provided.

  In the embodiment shown in FIG. 2, a pair of intervening layers 3-1a and 3-1b are provided in the vicinity of one corner Cn on the two opposing surfaces 1a-1 and 1a-2 of the outer peripheral surface 1a. The other pair of intervening layers 3-2a and 3-2b are arranged in the vicinity of the other corner Cn. In addition, a pair of intervening layers 3-3a and 3-3b are arranged in the vicinity of one corner Cn on the two opposing surfaces 1a-3 and 1a-4 of the outer peripheral surface 1a, and the other of the other surfaces 1a-3 and 1a-4. Another pair of intervening layers 3-4a and 3-4b are arranged in the vicinity of the corner Cn. In another embodiment (not shown), one intervening layer 3 that covers almost the entire surface, not two near the corner, is disposed on one surface of the outer peripheral surface 1a.

  When the intervening layer 3 is viewed in a cross section in the stacking direction S (FIG. 1), the force in the direction perpendicular to the stacking direction S is provided along the stacking direction S from one end to the other end of the fuel cell body 1. This is to prevent the position of each fuel cell unit from being displaced when the is added, and to reliably hold the central portion of the stacked body 11 that is particularly likely to be displaced. Further, when the intervening layer 3 is viewed in a cross section perpendicular to the stacking direction S (FIG. 2), at least four corners of the case 2 are provided when the intervening layer 3 is about to be displaced. This is because when the force applied to the intermediate layer 3 is supported by the case 2, the force applied to the intervening layer 3 can be stably supported by supporting at least the corners of the case 2 having high rigidity. In addition, the interposition layer 3 is disposed so as to be paired with two opposing surfaces of the outer peripheral surface 1a because the fuel cell main body 1 is evenly restrained from both sides of the fuel cell main body 1 via the interposition layer 3. This is because a force to crush and a force to crush the intervening layer 3 is applied.

  The intervening layer 3 has electrical insulation and restoring force. The restoring force is a force for returning to the original dimension when the dimension is changed by an external force. The material of the intervening layer 3 is not particularly limited as long as it has electrical insulation and restoring force, and is exemplified by a resin elastic material. The intervening layer 3 preferably further has dilatant characteristics. The dilatant characteristic is a property that exhibits fluidity to a slow input load, deforms slowly, behaves like a solid to a sudden input load, and hardly deforms. In this case, the material of the intervening layer 3 is not particularly limited as long as it further has dilatant characteristics in addition to the above characteristics, and examples thereof include a mixture of a resin and a solid material. Specifically, a mixture of silicone oil and boric acid is exemplified. In addition, products such as Dow Corning 3179 (Dow Corning is a registered trademark) manufactured by Dow Corning and M48 and M49 manufactured by Wacker GmbH may be used. A mixture of silicone resin (including gel) and silica can also be used. In FIG. 1 and FIG. 2 and the embodiment shown below, the case where the intervening layer 3 further has a dilatant characteristic in addition to the electrical insulation and the restoring force will be described.

  As the intervening layer 3, a layer having a thickness larger than the distance D between the outer peripheral surface 1 a of the fuel cell main body 1 and the inner peripheral surface 2 a of the side wall 22 a of the case 2 is used in the state of zero load. And the intervening layer 3 arrange | positioned at the outer peripheral surface 1a is crushed, the thickness becomes smaller than the distance D, and the fuel cell main body 1 is accommodated in the case 2 before the thickness expands to the distance D, The fuel cell body 1 is accommodated in the case 2 without being affected by the intervening layer 3. In this case, the intervening layer 3 subsequently recovers to the same thickness as the distance D due to its restoring force, but since the original thickness is larger than the distance D, the fuel cell body 1 in a compressed state without recovering the original thickness. The outer peripheral surface 1a of the case 2 and the inner peripheral surface 2a of the side wall 22a of the case 2 are disposed. By disposing the intervening layer 3 in a compressed state, the impact applied to the fuel cell main body 1 is easily absorbed, and the displacement of the fuel cell main body 1 is further suppressed.

  The reason why it is preferable to use a material having a dilatant characteristic for the intervening layer 3 is as follows.

  When the fuel cell stack A is mounted on a vehicle, a sudden impact may occur due to a vehicle collision or the like. When the fuel cell stack A receives a sudden impact, a force in a direction parallel to and perpendicular to the stacking direction S is applied to the fuel cell main body 1. Of these, each fuel cell single cell of the stacked body 11 tends to shift from the original position in the direction of the force due to the force in the direction perpendicular to the stacking direction S. In particular, among the single fuel cells, the single fuel cell located at the center in the stacking direction S is more easily displaced in the direction perpendicular to the stacking direction S than the single fuel cell at both ends. Try to. Here, an intervening layer 3 having a dilatant characteristic is disposed on the outer peripheral surface 1a on the side of the stacked body 11 in the direction perpendicular to the stacking direction S. Therefore, when each fuel cell single cell is about to shift rapidly due to an impact at the time of a vehicle collision, the intervening layer 3 receives a sudden change and behaves like a solid. As a result, the intervening layer 3 can suppress the occurrence of misalignment of each fuel cell single cell in the stacked body 11, and can suppress the occurrence of leakage of the reaction gas and the cooling medium due to the misalignment.

  On the other hand, each fuel cell single cell may be slowly deformed in a direction perpendicular to the stacking direction S due to, for example, thermal expansion of the fuel cell single cell of the stacked body 11 instead of a vehicle collision or the like. Here, an intervening layer 3 having a dilatant characteristic is disposed on the outer peripheral surface 1a on the side of the stacked body 11 in the direction perpendicular to the stacking direction S. Therefore, when the fuel cell unit cell is slowly deformed due to thermal expansion or the like, the intervening layer 3 undergoes a slow change and changes fluidly. As a result, the intervening layer 3 is deformed so as to fill a gap between the fuel cell single cell and the intervening layer 3 caused by the deformation of the fuel cell single cell. As described above, since the generation of the gap between the fuel cell unit cell and the intervening layer 3 is suppressed, even if the fuel cell unit cell suddenly shifts at the time of a vehicle collision, the shift is suppressed by the intervening layer 3, thereby Generation | occurrence | production of the leak of the reactive gas and cooling medium resulting from the position shift of a fuel cell single cell is suppressed.

  Next, a method for manufacturing the fuel cell stack A according to the embodiment will be described. 3 to 5 and 7 to 11 are schematic cross-sectional views showing each manufacturing process of the fuel cell stack A.

  First, the lid plate 21 of the case 2 is held by a fixing jig (not shown). Then, as shown in FIG. 3, the fuel cell main body 1 is pressed against the held lid plate 21 with a load P. Thereby, the fuel cell body 1 is compressed with the load P from the side in contact with the lid plate 21, that is, from the side opposite to the lid plate 21 side. In this manufacturing method, the fuel cell main body 1 continues to be compressed with the load P until the lid plate 21 and the case main body 22 are fastened.

  Next, the intervening layer 3 is prepared. The thickness of the intervening layer 3 is a thickness d1 larger than the distance D between the outer peripheral surface 1a of the fuel cell main body 1 and the inner peripheral surface 2a of the side wall 22a of the case 2 when the fuel cell main body 1 is accommodated in the case 2. is there. The thickness d1 is the thickness when the load in the thickness direction applied to the intervening layer 3 is zero. The length of the intervening layer 3 is the length from one end to the other end of the fuel cell main body 1 (FIG. 1), and the width of the intervening layer 3 is a width that covers at least the vicinity of the corner Cn of the fuel cell main body 1. The number of layers 3 is, for example, two on each of the four surfaces of the outer peripheral surface 1a, for a total of eight (FIG. 2). Then, as shown in FIGS. 4 and 5, two intervening layers 3 are arranged in the vicinity of the four corners Cn of the outer peripheral surface 1 a of the fuel cell main body 1. 4 is an E4-E4 sectional view of FIG. 5, and FIG. 5 is an E5-E5 sectional view of FIG. That is, the interposition layers 3-1a, 3-1b and 3-2a, 3-2b are respectively arranged on the two faces 1a-1, 1a-2 facing each other, and the interposition layers 3-3a, 3-3b and 3-4a, 3-4b is arranged on each of the two faces 1a-3 and 1a-4 facing each other.

  Subsequently, a compressor 30 as shown in FIG. 6 is prepared. The compressor 30 is a jig for crushing the intervening layer 3. The compressor 30 includes a rectangular frame 32 that is slightly larger than a cross section perpendicular to the stacking direction S of the fuel cell main body 1. The frame 32 includes frame members 32-1 to 32-4 corresponding to the sides of the rectangle, and is detachably coupled to each other. Specifically, one end of the frame member 32-1 and one end of the frame member 32-2, the other end of the frame member 32-2 and one end of the frame member 32-3, the other end of the frame member 32-3, and the frame member 32. -4, and the other end of the frame member 32-4 and the other end of the frame member 32-1 are detachably coupled to each other. The roller 31 has a cylindrical shape or a columnar shape, and an axis of the cylinder or the column and the frame 32 overlap with each other, and are supported by the frame 32 so as to be rotatable around the frame 32, for example. In the embodiment shown in FIG. 6, the rollers 31-1a and 31-2a of the rollers 31 are the frame member 32-1, the rollers 31-1b and 31-2b are the frame member 32-2, and the rollers 31-3a and 31-2a. 31-4a is rotatably supported by the frame member 32-3, and the rollers 31-3b and 31-4b are rotatably supported by the frame member 32-4. At this time, the four frames 32-1, 32-2, 32-3, and 32-4 extend in the common plane RS. When this plane RS is referred to as a compressor plane, the innermost portion 31a among the outer surfaces of the rollers 31-1a to 31-4b is located in the compressor plane RS. In another embodiment (not shown), the shaft of the roller 31 and the frame 32 are separate members and are coupled at the end of the roller 31.

  Next, as shown in FIG. 7, the compressor 30 is set on the side opposite to the lid plate 21 side in the fuel cell main body 1. However, the compressor plane RS is perpendicular to the stacking direction S, and the distance dg between the innermost portion 31a of the outer surface of each roller 31 and the outer peripheral surface 1a of the fuel cell body 1 is almost the same value. The compressor 30 is arranged so that the rotation axis of the roller 31, that is, the frame 32 extends in a direction perpendicular to the stacking direction S. The distance dg at each roller 31 is smaller than the thickness d1 of the intervening layer 3 and smaller than the distance D between the outer peripheral surface 1a of the fuel cell main body 1 and the inner peripheral surface 2a of the side wall 22a of the case 2.

  Thereafter, as shown in FIG. 8, the intervening layer 3 is crushed by a roller 31, and the intervening layer 3 and the fuel cell main body 1 are accommodated in the case 2. Specifically, first, the compressor plane RS is perpendicular to the stacking direction S, and the distances dg at the respective rollers 31 are almost the same value, while maintaining that value, the lid plate 21 side The compressor 30 is moved along the stacking direction S from the opposite side to the lid plate 21 side. In other words, the compressor 30 is moved so that the fuel cell body 1 is inserted inside the compressor 30. At this time, since the distance dg between the innermost portion 31a of the outer surface of the roller 31 and the outer peripheral surface 1a of the fuel cell body 1 is smaller than the thickness d1 of the intervening layer 3, the roller 31 collides with the intervening layer 3. Layer 3 is deformed. Here, since the rotating shaft of the roller 31 extends perpendicularly to the stacking direction S, the roller 31 crushes the intervening layer 3 toward the outer peripheral surface 1 a while rotating (spinning) around the frame 32. As a result, the crushed intervening layer 3 has a thickness d2. However, distance dg ≦ thickness d2 <distance D. Here, since the intervening layer 3 has a dilatant characteristic, it can be easily deformed by slowly deforming, that is, by slowly crushing. In this case, the return to the original shape also slowly returns, that is, the intervening layer 3 maintains a thin state for a while.

  As shown in FIG. 9, when the compressor 30 and the fuel cell main body 1 are viewed from the side opposite to the lid plate 21 without considering the case main body 22, the compressor 30 is disposed so as to surround the fuel cell main body 1. The The pair of rollers 31-1 a and 31-1 b has a pair of intervening layers 3-1 a and 3-1 b arranged on the two faces 1 a-1 and 1 a-2 facing each other from one end in the stacking direction S to the other. Crush to the end. Similarly, the pair of rollers 31-2a and 31-2b includes a pair of intervening layers 3-2a and 3-2b arranged on two opposing surfaces 1a-1 and 1a-2, at one end in the stacking direction S. Crush to the other end. Further, the pair of rollers 31-3a and 31-3b has a pair of intervening layers 3-3a and 3-3b disposed on the two faces 1a-3 and 1a-4 facing each other from one end in the stacking direction S. Crush to the other end. Further, the pair of rollers 31-4a and 31-4b has a pair of intervening layers 3-4a and 3-4b disposed on the two facing surfaces 1a-4 and 1a-4 from one end in the stacking direction S. Crush to the other end.

  When the compressor 30 reaches the lid plate 21, the coupling between the frame members 32-1 to 32-4 of the compressor 30 is removed, and the compressor 30 is removed from the fuel cell main body 1.

  At this time, the force with which the pair of rollers 31 crush the pair of intervening layers 3 has the same magnitude, and the directions are opposite to each other. Therefore, even if the force by which the roller 31 crushes the intervening layer 3 is applied to the fuel cell main body 1, the force does not shift the fuel cell single cell in the direction perpendicular to the stacking direction S. Thereby, even when the intervening layer 3 is crushed on the fuel cell main body 1, it is possible to prevent the plurality of fuel cell single cells of the fuel cell main body 1 from being displaced by an external force.

  Further, as shown in FIGS. 8 and 9, in parallel with the crushing of the intervening layer 3 by the compressor 30, before the thickness of the intervening layer 3 swells to the distance D, the case body 22 of the case 2 is moved. The fuel cell body 1 is accommodated in the case body 22 through the opening while being moved relative to the fuel cell body 1. That is, the fuel cell main body 1 and the intervening layer 3 are accommodated in the case 2. Thereafter, the case main body 22 is fastened to the lid plate 21 with a fastening member (not shown) such as a bolt. At this time, as shown in FIG. 10, since the intervening layer 3 on the outer peripheral surface 1a of the fuel cell main body 1 accommodated in the case main body 22 has a thickness of about d2, the case main body 22 is hardly touched by the intervening layer 3. The fuel cell main body 1 can be easily accommodated. In another embodiment (not shown), after the crushing of the intervening layer 3 by the compressor 30 is finished and the compressor 30 is removed from the fuel cell body 1, before the thickness of the intervening layer 3 expands to the distance D, The fuel cell main body 1 is accommodated in the case main body 22 through the opening. The load P can be applied through an opening (for wiring and piping) provided in the bottom wall 22b of the case 2. In still another embodiment (not shown), the case main body 22 is not provided with the bottom wall 22b, and after the fuel cell main body 1 is accommodated in the case main body 22 through the opening, the case main body 22 is connected to a fastening member such as a bolt (not shown). The bottom wall 22b is fastened to the side wall 22a with a fastening member (not shown) such as a bolt. In still another embodiment (not shown), there are a plurality of compressors 30, and a plurality of compressors 30 are arranged along the stacking direction S at intervals, and the plurality of compressors 30 push the intervening layer 3. Crush.

  Thereafter, as shown in FIG. 11, the intervening layer 3 returns to the original shape, that is, the thickness d <b> 1 by the restoring force. However, since the gap between the outer peripheral surface 1a and the inner peripheral surface 2a is only the distance D, the intervening layer 3 is held between the outer peripheral surface 1a and the inner peripheral surface 2a in a compressed state after returning to the thickness D. The

  FIG. 12 is a side view showing the relationship of the thickness of the intervening layer 3 in each manufacturing process. In the state where the load is zero, that is, in the step of FIG. 4, the thickness of the intervening layer 3 is d1, but in the state of being crushed by the roller 31, that is, in the step of FIG. Thereafter, the thickness of the intervening layer 3 gradually recovers, and finally the thickness of the intervening layer 3 becomes D in the stage of FIG. 11 and is held in a compressed state. However, d2 <D <d1.

  Thus, the fuel cell stack A is completed. At this time, while the thickness of the intervening layer 3 is expanded and the thickness is restored, the gap with the case 2 is filled in accordance with the unevenness of each plate of the fuel cell main body 1 and each single cell of the fuel cell, and the outer peripheral surface 1a of the fuel cell main body 1 It arrange | positions in the compression state between the internal peripheral surfaces 2a of case 2. FIG.

  13 and 14 are cross-sectional views for explaining the effect of using the roller 31. FIG. In the manufacturing method described above, when the intervening layer 3 is crushed by the roller 31, the roller 31 rotates (spins) as shown in FIG. 13, so that the roller 31 translates in the direction Sa toward the lid plate 21 in the stacking direction S. Even in this case, the intervening layer 3 does not swell in the front area FA of the roller 31. This is because when the roller 31 and the intervening layer 3 come into contact and contact with each other, the roller 31 rotates, so that almost no force in the translational direction acts on the intervening layer 3, and the force in the direction of the fuel cell body 1, that is, intervening. This is because the force in the direction of crushing the layer 3 works dominantly.

  On the other hand, if a cylindrical body 131 that does not rotate (spin) is used as shown in FIG. 14, if the cylindrical body 131 is translated in the direction Sa of the lid plate 21 in the stacking direction, in the front area FA of the cylindrical body 131. As a result, the intervening layer 3 swells to form the convex portion 3r. If it becomes so, the thickness of the intervening layer 3 including the convex part 3r will exceed the distance D, and there exists a possibility that it may become difficult to accommodate the fuel cell main body 1 in the case main body 22. FIG. This is because when the cylindrical body 131 and the intervening layer 3 are brought into contact and in close contact with each other, the cylindrical body 131 does not rotate, so that a force in the translational direction acts dominantly on the intervening layer 3, so It is considered that the upper portion, that is, the portion in contact with the cylindrical body 131 is pushed out to the front area FA so as to be scraped off.

  In this way, by using the compressor 30 that can rotate the roller 31, the intervening layer 3 can be crushed to a desired thickness d <b> 2 without forming a convex portion.

  FIG. 15 is a cross-sectional view showing the relationship of the thickness of the intervening layer 3 before and after crushing the intervening layer 3. For example, in the two opposing surfaces 1a-1 and 1a-2 on the outer peripheral surface 1a, the initial thickness of the intervening layer 3 is p1 and q1, respectively, and the thickness after being crushed is p2 and q2. However, p1 and q1 correspond to the above d1, and p2 and q2 correspond to the above d2.

  FIG. 16 is a cross-sectional view showing an example of the relationship between the intervening layer 3 and the single fuel cell before and after crushing the intervening layer 3. When viewed in detail, the relative position of the fuel cell single cell 11a of the stacked body 11 may be shifted in a direction perpendicular to the center line C in the stacking direction S of the stacked body 11 in some cases. For example, when the length of each fuel cell single cell 11a is L, it is ideal that the upper length with respect to the center line C is L / 2 and the lower length is L / 2. However, due to the stacking variation, a part of the fuel cell single cell 11a is slightly shifted outward or inward with respect to the center line C. In the example shown on the left side of FIG. 16, in the fuel cell single cells 11a1, 11a3, and 11a5, the positions of the upper and lower end portions are respectively the lines C1 and C2 at the upper and lower L / 2 positions. Matching. However, in the fuel cell single cells 11a2 and 11a6, the position of the upper end is slightly shifted inward from the line C1, and the position of the lower end is slightly shifted outward from the line C2. Assuming that the magnitude of this shift is 1 unit, the fuel cell single cells 11a2 and 11a6 are shifted by 1 unit inward and by 1 unit outward. Further, in the fuel cell unit cell 11a4, the position of the upper end is shifted by one unit outward from the line C1, and the position of the lower end is shifted by one unit inward from the line C2. Further, in the fuel cell single cell 11a7, the position of the upper end is shifted by 2 units inward from the line C1, and the position of the lower end is shifted by 2 units outward from the line C2. However, by crushing the intervening layer 3 as shown in FIG. 15, along the outside of each fuel cell single cell 11 a, regardless of the displacement of each fuel cell single cell 11 a as shown in the diagram on the right side of FIG. 16. The intervening layer 3 can be disposed without a gap. At that time, for example, at the upper end portion of the fuel cell unit cell 11a4, the amount of compression of the intervening layer 3 is large because the outward displacement is large, and thus a large force acts inward. However, since the inward displacement is large at the lower end portion, the amount of compression of the intervening layer 3 is small, and therefore inward force hardly acts. Therefore, the fuel cell single cell 11a4 is not excessively compressed as a whole. In this manner, the intervening layer 3 can be crushed substantially uniformly so that the fuel cell single cell is not excessively compressed in the left-right direction and the up-down direction with respect to the center line C of the stacked body 11.

  In this case, in FIG. 15, for example, if p1 and q1 (= d1) are 5 mm and p2 and q2 (= d2) are about 2 mm, | (p1-p2) − (q1−q2) | ≦ 1. 5 mm is preferable. By doing in this way, the intervening layer 3 is compressed uniformly in all the outer peripheral surfaces 1a of the fuel cell main body 1, and the fuel cell main body 1 is hold | maintained equally within the case 2. FIG.

  In the fuel cell stack manufacturing method described above, the intervening layer 3 having a restoring force to return to the original dimensions when deformed is used. That is, the intervening layer 3 disposed on two opposing surfaces of the outer peripheral surface 1 a of the fuel cell main body 1 is crushed by a pair of rollers 31 while applying a force from the outside to the inside of the fuel cell main body 1. At this time, the force with which the pair of rollers 31 crush the intervening layer 3 has the same magnitude and the directions are opposite to each other, and therefore cancel each other. Thereby, the intervening layer 3 can be crushed without generating an external force in the fuel cell main body 1 and without generating a shift of the single fuel cell in the stacked body 11. Further, by crushing the intervening layer 3 to be less than the distance (gap) D between the fuel cell main body 1 and the case 2, the external force required to insert the fuel cell main body 1 into the case 2 can be reduced, and the case 2 of the fuel cell main body 1 can be reduced. The ease of insertion into can be improved. In addition, the intervening layer 3 can be easily disposed in a compressed state between the fuel cell main body 1 and the case 2 by restoring the thickness of the intervening layer 3 after the fuel cell main body 1 is accommodated in the case 2. Further, since the case 2 has functions of watertightness, fastening, and external restraint, the configuration for realizing these functions is simplified, the size of the fuel cell stack A can be reduced, and the cost can be reduced. Furthermore, when the fuel cell stack A receives a sudden impact, the intervening layer 3 behaves like a solid, suppresses the occurrence of misalignment of each fuel cell single cell, and reacts with the reaction gas and cooling medium caused by the misalignment. The occurrence of leakage can be suppressed. Further, when the fuel cell unit cell is gently deformed, the intervening layer 3 exhibits fluidity, and is deformed so as to fill a gap generated by the deformation of each fuel cell unit cell. Generation | occurrence | production of the clearance gap between can be suppressed.

  As described above, in the method of manufacturing the fuel cell stack A according to the embodiment, the intervening layer 3 can be appropriately disposed between the outer peripheral surface of the fuel cell main body and the inner peripheral surface of the case.

  Next, another embodiment will be described with reference to FIGS.

  17 and 18 are a cross-sectional view and a plan view showing the case 2 of another embodiment. 17 is a cross-sectional view taken along line E17-E17 in FIG. In the case 2, the compressor 30 is provided at the end of the side wall 22 a of the case body 22 on the opening side. Therefore, the roller 31 is provided at the end of the side wall 22a on the opening side. The frame 32 is attached to the inner side of the side wall 22a, that is, the inner peripheral surface 2a. The roller 31 is rotatably supported by the frame 32 with the frame 32 as a rotation axis. The rotation axis of the roller 31 extends in a direction perpendicular to the stacking direction S. In order to improve water tightness, a sealing material is inserted into the boundary between the roller 31 and the side wall 22a as necessary after the case body 22 and the lid plate 21 are fastened. In another embodiment (not shown), the portion near the roller 31 is formed in a convex shape so that the side wall 22a covers the entire roller 31, that is, the side of the roller 31 that does not face the fuel cell main body 1.

  As for the manufacturing method of the fuel cell stack A, as shown in FIG. 19, the fuel cell main body 1 is accommodated in the case main body 22 while the intervening layer 3 is crushed by a roller 31. That is, the step of crushing the intervening layer 3 with the roller 31 and the step of housing the fuel cell main body 1 in the case 2 are performed in parallel. In this case, it is not necessary to remove the compressor 30 after crushing the intervening layer, and productivity can be improved. Other processes are the same as those in the embodiment of FIGS.

  Thus, by incorporating the compressor 30 having the roller 31 into the case 2, the step of crushing the intervening layer 3 in advance and the step of housing the fuel cell main body 1 in the case 2 can be performed substantially simultaneously. Thereby, the time concerning the assembly | attachment of the fuel cell stack A can be shortened, productivity can be improved, and manufacturing cost can be reduced. Further, the manufacturing cost can be reduced by eliminating the compressor 30. Further, even when a material having a quick recovery of the thickness of the intervening layer 3 is used for the intervening layer 3, the housing of the fuel cell main body 1 in the case 2 can be completed more reliably before the recovery. Further, a material having a high thickness recovery force, that is, a high binding force can be used as the intervening layer 3.

  Next, still another embodiment will be described with reference to FIGS.

  20 and 21 are a sectional view and a plan view showing the case 2 of still another embodiment. 20 is a cross-sectional view taken along line E20-E20 in FIG. In the case 2, the compressor 30 is provided at the end of the side wall 22 a of the case body 22 on the opening side, and a plurality of compressors 30 are provided along the stacking direction S at intervals. Accordingly, not only the roller 31 is provided at the opening side end of the side wall 22a, but also the roller 31 is provided along the stacking direction S. The number of the compressors 30 is arbitrary. With respect to the roller 31 other than the end of the opening on the side wall 22a, a hole is formed in the side wall 22a so that the side of the roller 31 that does not face the fuel cell body 1 is exposed to the outside of the side wall 22a. In order to improve water tightness, a sealing material is inserted into the boundary between the roller 31 and the side wall 22a as necessary after the case body 22 and the lid plate 21 are fastened. The frame 32 is attached to the inner side of the side wall 22a, that is, the inner peripheral surface 2a. In another embodiment (not shown), the portion near the roller 31 is formed in a convex shape so that the side wall 22a covers the entire roller 31, that is, the side of the roller 31 that does not face the fuel cell main body 1.

  Regarding the method of manufacturing the fuel cell stack A, as shown in FIG. 22, the fuel cell main body 1 is accommodated in the case main body 22 while the intervening layer 3 is crushed by a plurality of rollers 31. That is, the step of crushing the intervening layer 3 with the roller 31 and the step of housing the fuel cell main body 1 in the case 2 are performed in parallel. In this case, it is not necessary to remove the compressor 30 after crushing the intervening layer, and productivity can be improved. Other processes are the same as those in the embodiment of FIGS.

  In this case, the same effects as those of the other embodiments of FIGS. In addition, in this further embodiment, by incorporating a compressor 30 having a plurality of rollers 31 into the case 2, the intervening layer 3 is crushed not only at the opening end of the case 2 but also inside the case 2. be able to. Thereby, a material having a higher thickness recovery force, that is, a higher restraining force can be used as the intervening layer 3. When disassembling the manufactured fuel cell stack A, the plurality of rollers 31 crush the intervening layer 3, so that the case body 22 can be easily removed.

  Next, still another embodiment will be described with reference to FIG.

  In the embodiment shown in FIG. 2, the intervening layer 3 is disposed on two sets of two opposing faces 1a-1, 1a-2 and 1a-3, 1a-4 of the outer peripheral face 1a. In the embodiment shown in FIG. 23, the intervening layer 3, that is, the intervening layers 3-1 a, 3-1 b / 3-2 a only on a pair of two facing surfaces 1 a-1 and 1 a-2 of the outer peripheral surface 1 a, 3-2b is arranged. When the restraining force of the intervening layer 3 is large, for example, when the degree of compression of the intervening layer 3 is large, even if there is no intervening layer 3 on the surfaces 1a-3 and 1a-4, the surfaces 1a-1 and 1a-2 The intervening layer 3 alone can provide the same effects as those in the embodiment of FIG. 2, such as preventing the displacement of the single fuel cell in the direction perpendicular to the surfaces 1a-3 and 1a-4. In addition, since the intervening layer 3 is reduced, productivity can be improved and manufacturing cost can be reduced. In another embodiment (not shown), one intervening layer 3 that covers almost the entire surface, not two near the corner, is disposed on one surface of the outer peripheral surface 1a.

DESCRIPTION OF SYMBOLS 1 Fuel cell main body 1a Outer peripheral surface 2 Case 2a Inner peripheral surface 3 Intervening layer 11 Laminated body 31 Roller A Fuel cell stack D Distance d1 Thickness S Lamination direction

Claims (7)

A fuel cell main body including a stack formed by stacking a plurality of fuel cell single cells along the stacking direction; four side walls surrounding the fuel cell main body along the stacking direction; and at least one opening. A fuel cell stack including a case in which the fuel cell main body is accommodated, and an intervening layer disposed between the fuel cell main body and the case and having a restoring force to return to the original dimensions when deformed. A manufacturing method of
Thickness greater than the distance between the outer peripheral surface of the fuel cell main body along the stacking direction and the inner peripheral surface of the side wall of the case facing the outer peripheral surface when the fuel cell main body is accommodated in the case Arranging the intervening layer having each of two opposing surfaces of the outer peripheral surface;
Crushing the intervening layer disposed on the two opposite surfaces with a roller from one end to the other end in the stacking direction of the intervening layer so that the thickness of the intervening layer is smaller than the distance;
Storing the fuel cell main body in the case through the opening while moving the case relative to the fuel cell main body before the thickness of the intervening layer expands to the distance;
A method for manufacturing a fuel cell stack. The step of crushing the intervening layer with the roller and the step of accommodating the fuel cell main body in the case are performed in parallel, and the fuel cell main body is accommodated in the case while crushing the intervening layer with the roller. The method for producing a fuel cell stack according to claim 1. The method of manufacturing a fuel cell stack according to claim 2, wherein the roller is provided on the side wall of the case. The method for manufacturing a fuel cell stack according to claim 3, wherein the roller is provided at an end of the side wall of the case on the opening side. The roller includes a plurality of rollers arranged along the stacking direction,
The step of crushing the intervening layer with the roller,
The method for producing a fuel cell stack according to any one of claims 1 to 4, further comprising a step of crushing the intervening layer with the plurality of rollers. The step of disposing the intervening layer on the two faces facing each other,
Arranging the intervening layer on each of the two opposing surfaces of the outer peripheral surface, and disposing each of the intervening layers on the other two opposing surfaces of the outer peripheral surface,
The step of crushing the intervening layer with the roller,
6. The method includes crushing the intervening layer disposed on the two opposing surfaces with a roller and crushing the interposing layer disposed on the other two opposing surfaces with another roller. 6. A method for producing a fuel cell stack according to the item. The method for manufacturing a fuel cell stack according to any one of claims 1 to 6, wherein the intervening layer has a dilatant characteristic.

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