JP6164524B2 - Fuel cell stack structure - Google Patents

Description

  The present invention relates to a fuel cell stack used as a power source for driving a moving body such as an automobile, and more particularly to a fuel cell stack including a stacked body formed by stacking a plurality of single cells.

  Conventionally, as a fuel cell stack structure provided with a single cell stack, for example, there is one described in Patent Document 1 under the name of a fuel cell stack device. A fuel cell stack device described in Patent Document 1 includes a stack formed by stacking a plurality of cells, end plates disposed on both sides in the stacking direction of the stack, and a pressure plate provided between the stack and one end plate. I have.

  In the fuel cell stack device, a spring is interposed between one end plate and the pressure plate, and the end plates on both sides are connected by a pair of tension members. In this fuel cell stack device, the stack is stacked by the end plate and the tension member while applying a predetermined load in the stacking direction to the stack by the spring. In addition, as a fuel cell stack provided with a single cell stack, there are those described in Patent Documents 2 and 3.

JP 2009-181723 A JP 2010-123492 A Japanese Patent Laid-Open No. 9-92324

  However, in the conventional fuel cell stack device as described above, for example, when used as a vehicle power source, the entire stack also vibrates due to vibration during travel, which causes changes in the end plate and tension members over time such as wear and deterioration. Thus, there is a problem that the binding force of the stack is reduced, and it has been a problem to solve such a problem.

  The present invention has been made paying attention to the above-described conventional problems, and in a fuel cell stack structure including a single-cell laminate, the vibration resistance of the laminate is improved, and the binding force of the laminate is increased. An object of the present invention is to provide a fuel cell stack structure that can be maintained over a long period of time.

The fuel cell stack structure of the present invention includes a laminate formed by stacking rectangular plate-shaped single cells, and restrains the stack in the stacking direction of the single cells and suppresses movement in the direction along one opposite side of the single cells. First suppressing means and second suppressing means for suppressing movement in the direction along the other opposite side of the single cells , wherein the first suppressing means and the second suppressing means constitute a case of the laminate . . In the fuel cell stack structure, the second restraining means includes a curved substrate portion covering the one side of the laminate on the opposite side of the laminate, and the other end of the laminate in succession to both ends of the substrate portion. a pair of holding portions in contact with the stack end face opposite sides side, and both holding portions have a spring property to be pressed against the laminate, the substrate portion of the second suppression means, and a curved surface protruding outward In this configuration , a gap is formed between the laminate and the substrate portion, and the above configuration is used as a means for solving the conventional problems.

The fuel cell stack structure of the present invention is a case-integrated fuel cell stack structure including a single-cell stack, and the in-plane direction (surface) between the single cells is defined by the first and second restraining means constituting the case. The vibration of the laminate is also absorbed by the spring property of the second restraining means while suppressing the movement in the direction along the direction), so that the vibration resistance performance of the laminate can be improved and the restraining force of the laminate can be maintained over a long period of time. Can do.

In the fuel cell stack structure described above, since the second suppressing means has a curved substrate portion, a larger elastic force can be obtained by making the distance between the holding portions smaller than the width of the stacked body. It becomes possible, and a laminated body can be clamped with sufficient force. Thereby, the function which suppresses a motion between single cells, and the vibration absorption function of a laminated body are improved further. Further, in the fuel cell stack structure described above, in the case-integrated structure, a gap is formed between the curved substrate portion protruding outward and the laminate, and the gap is used as a cooling air circulation space. obtain.

FIG. 2 is a perspective view (A) of a fuel cell stack and a perspective view (B) in an exploded state for explaining a fuel cell stack structure of the present invention. They are a perspective view (A) explaining 1st Embodiment of a fuel cell stack structure, sectional drawing (B) before mounting | wearing of a reinforcement board, and sectional drawing (C) after mounting | wearing of a reinforcement board. It is sectional drawing explaining 2nd Embodiment of a fuel cell stack structure. It is a perspective view explaining 3rd Embodiment of a fuel cell stack structure. It is sectional drawing explaining 4th Embodiment of a fuel cell stack structure. It is sectional drawing explaining 5th Embodiment of a fuel cell stack structure.

<First Embodiment>
As shown in FIG. 1B, the fuel cell stack FS shown in FIG. 1 includes at least two cell modules M in which a plurality of rectangular plate-like single cells C are stacked and integrated, and the cell module M And a seal plate P interposed therebetween. The unit cell C and the seal plate P in the illustrated example are both rectangular plates having substantially the same vertical and horizontal dimensions. In FIG. 1B, two cell modules M and one seal plate P are shown, but in reality, a larger number of cell modules M and seal plates P are stacked.

  Further, in the fuel cell stack FS, end plates 56A and 56B are arranged at both ends in the stacking direction of the cell modules M, respectively, and a stacking end surface on the long side that is one side of the single cell C (in FIG. 1). Fastening plates 57A and 57B are provided on the upper and lower surfaces, and reinforcing plates 58A and 58B are provided on the end surface on the short side which is the opposite side. Each of the fastening plates 57A, 57B and the reinforcing plates 58A, 58B has a size over the entire length in the stacking direction of the stacked body A composed of the cell module M and the seal plate P, and is connected to both end plates 56A, 56B by bolts (not shown). .

  In this way, the fuel cell stack FS has a case-integrated structure as shown in FIG. 1A. Each cell module M and the seal plate P are constrained and pressurized in the stacking direction, and each unit cell C is predetermined. In order to maintain good gas sealing performance and electrical conductivity.

  Although not shown in detail, the single cell C includes a membrane electrode assembly and a pair of separators sandwiching the membrane electrode assembly, and anode gas and cathode gas are interposed between the membrane electrode assembly and each separator. Each gas flow path is formed.

  The membrane electrode assembly is generally called MEA (Membrane Electrode Assembly), and detailed illustration is omitted. However, the membrane electrode assembly has a structure in which an electrolyte layer made of a solid polymer is sandwiched between an anode electrode layer and a cathode electrode layer. Have. The separator is a metal plate member having an inverted shape, and is made of, for example, stainless steel, and can be formed into an appropriate shape by pressing.

  As shown in FIG. 1, the single cell C has three manifold holes H1 to H3 and H4 to H6 arranged along both short sides. The manifold holes H1 to H3 shown on the left side in FIG. 1 are for anode gas supply (H1), coolant discharge (H2) and cathode gas discharge (H3) from the upper side, and communicate with each other in the stacking direction. Forming each manifold. In addition, the manifold holes H4 to H6 shown on the right side in FIG. 1 are for the cathode gas supply (H4), the coolant supply (H5), and the anode gas discharge (H6) from the upper side. Communicate to form each manifold. The positional relationship between supply and discharge of each manifold hole H1 to H6 may be partially or entirely reversed.

  In addition, although illustration was abbreviate | omitted, the sealing material is arrange | positioned around the manifold holes H1-H6. These sealing materials also function as adhesives, and airtightly join the membrane electrode assembly and the separator. Further, the sealing material arranged around the manifold holes H1 to H6 has an opening at a corresponding portion in order to supply a fluid corresponding to each layer while maintaining the airtightness of each manifold.

  The unit cell C is formed by stacking a predetermined number of cell modules M. At this time, a flow path of the cooling liquid (for example, water) is formed between the adjacent single cells C, and a flow path of the cooling liquid is also formed between the adjacent cell modules M. Therefore, the seal plate P is disposed between the cell modules M, that is, in the flow path of the coolant.

  The seal plate P is formed by molding a single conductive metal plate, and is formed in the same size and in the same rectangular plate shape as the above-described single cell C in a plan view. Manifold holes H1 to H6 similar to the cell C are formed. This seal plate P is provided with a seal member (not shown) around each of the manifold holes H1 to H6, and an outer peripheral seal member and an inner peripheral seal member are provided in parallel on the entire periphery thereof. The member prevents rainwater or the like from entering from the outside, and the inner peripheral sealing member prevents leakage of the coolant flowing through the flow path between the cell modules M.

  Here, the fuel cell stack structure of the present invention includes a stacked body A formed by stacking rectangular plate-shaped (square plate-shaped) single cells C, a stacked body A constrained in the stacking direction of the single cells C, and a single cell. First suppression means for suppressing movement in the direction along the short side (one opposite side) between C and second suppression means for suppressing movement in the direction along the long side (the other opposite side) between the single cells C. I have. Further, when the fuel cell stack FS is mounted on a vehicle, as illustrated in FIG. 1, the stacking direction of the single cells C is set to the horizontal direction, and the stacking end surface on the long side of the single cell C is vertically It will be installed in the direction.

  The laminated body A in this embodiment is composed of the cell module M and the seal plate P, and may be configured to include both end plates 56A and 56B. The first restraining means is both fastening plates 57A and 57B, or both fastening plates 57A and 57B and both end plates 56A and 56B, and restrains the laminate A in the stacking direction of the single cells C and The movement in the direction along the short side of C (up and down direction in FIG. 1) is suppressed. On the other hand, the second restraining means is both reinforcing plates 58A and 58B, that is, reinforcing plates 58A and 58B mounted on both short sides of the single cell C of the laminate A, respectively, on the long side between the single cells C. Suppresses the movement in the direction along the left and right direction in FIG.

  In the fuel cell stack structure, the reinforcing plates 58A and 58B as the second suppressing means are curved so as to cover the stacking end surface on the short side of the single cell C in the stack A, as shown in FIG. And a pair of holding parts 12 and 12 that are in contact with the laminated end surface of the long side of the single cell C in the laminated body A continuously at both ends of the substrate part 11, and both the holding parts 12 and 12 are provided. It has the spring property which press-contacts to the laminated body A.

  Further, in this embodiment, the reinforcing plates 58A and 58B as the second suppressing means are formed in a curved shape in which the substrate portion 11 protrudes outward. In FIG. 2A, the fastening plates (57A, 57B) and the end plates (56A, 56B) as the first suppressing means are not shown.

  Furthermore, the board | substrate part 11 can be formed in a curved surface shape by giving shot peening to an outer side surface, and, thereby, spring property is provided so that the holding parts 12 and 12 may be press-contacted to the laminated body A. In addition, the substrate portion 11 can be formed into a curved surface by, for example, pressing.

  As shown in FIG. 2 (B), the reinforcing plates 58A and 58B are in a state in which both ends thereof are brought close to each other as shown in FIG. 2 (B). Then, as shown in FIG. 2C, the reinforcing plates 58A and 58B are attached to the laminate A so as to spread both the holding portions 12 and 12. As a result, the reinforcing plates 58A and 58B are configured so that the holding portions 12 and 12 are brought into pressure contact with the stacking end surfaces (upper and lower surfaces in each figure) of the long side of the single cell C in the stacked body A. Absorbs vibration in the direction along the short side of the cell C.

  Further, the reinforcing plates 58A and 58B absorb the vibration of the laminated body A, but include not only a function of damping the vibration but also an adjustment function of suppressing the vibration by increasing the resonance frequency of the laminated body A. As shown in FIG. 1, when the fuel cell stack FS is mounted on a vehicle with the stacking direction of the single cells C set in the horizontal direction and the stacking end face on the long side of the single cells C up and down, Vibration is likely to occur in the direction along the top (vertical direction). For this reason, the fuel cell stack FS has spring properties on the reinforcing plates (second suppressing means) 58A and 58B provided on both short sides.

  The fuel cell stack FS is the same as that in which the spring elements are assembled in the vibration direction of the laminate A (vertical direction in FIG. 2). In particular, in the case of this embodiment, the reinforcing plates 58A and 58B having the substrate part 11 and the holding part 12 extend over the entire length of the laminate A in the stacking direction, so that the spring elements are continuous in the cell stacking direction. As a result, the fuel cell stack FS holds the stacked body A with the reinforcing plates 58A and 58B having a simple structure, and increases the resonance frequency (natural frequency) of the stacked body A.

  In the fuel cell stack structure having the above-described configuration, the fastening plates 57A and 57B serving as the first restraining means and the reinforcing plates 58A and 58B serving as the second restraining means provide in-plane directions between the single cells C (directions along the surface). ). At the same time, the fuel cell stack structure absorbs vibration in the direction along the short side of the single cell C of the laminate A due to the spring properties of the reinforcing plates (second suppressing means) 58A and 58B. The vibration resistance is improved, and the binding force of the laminate A can be maintained for a long time.

  Further, in the fuel cell stack structure described above, the reinforcing plates 58A and 58B suppress the movement in the direction along the long side of the single cells C and also vibrate in the direction along the short side of the single cell C of the stacked body A. Absorb. For this reason, the reinforcing plates 58A and 58B have both the function of the first suppressing means, that is, the function of suppressing the movement in the direction along the short sides of the single cells C. Thereby, in the fuel cell stack structure, it is possible to employ a fastening band 67 indicated by a virtual line in FIG. 2 instead of the fastening plates 57A and 57B as the first suppressing means. In this case, the fastening band 67 has a main function of constraining the stacked body A in the stacking direction of the single cells C, and supplementarily suppresses movement in the direction along the short sides of the single cells C.

  Further, in the fuel cell stack structure described above, since the reinforcing plates (second suppressing means) 58A and 58B have the curved substrate portion 11, the distance between the holding portions 12 and 12 is set to the short side of the laminate A. By making it smaller than this width, it becomes possible to obtain a larger elastic force, and the laminate A can be held with a sufficient force.

  That is, when the substrate portion is flat, it is essential that the distance between the holding portions be equal to or greater than the width of the stacked body, and the force for sandwiching the stacked body depends on only the elastic force of the holding portion. On the other hand, in the reinforcing plates 58A and 58B, since the substrate portion 11 has a curved surface shape, the interval between the holding portions 12 and 12 is made smaller than the width on the short side of the laminate A to form the laminate A. When mounted, the substrate portion 11 is deformed to be nearly flat, so that the reaction force can be utilized. Thereby, the whole elastic force becomes large and the force which clamps a laminated body also increases, and the function which suppresses a motion between the single cells C and the vibrational absorption function of the laminated body A are improved further.

  Furthermore, in the fuel cell stack structure described above, since the second suppressing means is the reinforcing plates 58A and 58A having the substrate portion 11 and the holding portions 12 and 12 and having spring properties, the structure is extremely simple, Reduction of the number of points, improvement of assemblability, reduction of manufacturing cost, etc. can be realized.

  Further, in the fuel cell stack structure described above, the base plate portion 11 of the reinforcing plates 58A and 58B as the second restraining means is formed in a curved shape protruding outward, so that a sufficient spring property is imparted with a very simple configuration. be able to. In addition, when shot peening is employed when forming the substrate portion 11 in a curved surface shape, it is possible to arbitrarily set a spring constant to be applied to the substrate portion 11 by selecting a processing time, for example. Furthermore, by forming the substrate part 11 in a curved shape protruding outward as described above, a gap is formed between the laminate A and the substrate part 11, and this gap can be utilized as a circulation space for cooling air. .

  3-6 is a figure explaining the 2nd-5th embodiment of the fuel cell stack structure concerning this invention. In the following embodiments, the same parts as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

Second Embodiment
The fuel cell stack structure shown in FIG. 3 includes the laminate A equivalent to that of the first embodiment and the reinforcing plates 58A and 58 as the second restraining means, and the laminate A and the reinforcing plate (second restraining means). ) A complementary spring mechanism 61 that absorbs vibration in a direction along the long side of the single cell of the laminated body A is provided between the substrate portions 11 of 58A and 58B.

  The complementary spring mechanism 61 is a plate-shaped member having a size covering almost the entire surface of the short side stacking end surface of the single cell C in the stack A, and the outer side (in FIG. It has a bent portion 61A projecting to the right side), and has curved portions 61B and 61B directed to the laminate A side at both ends of the cross section, thereby imparting springiness in the thickness direction.

  In the fuel cell stack structure described above, the reinforcing plates 58A and 58B absorb vibration in the direction along the short side of the single cell C of the multilayer body A, and the complementary spring mechanism 61 allows the single cell of the multilayer body A to be absorbed. The vibration in the direction along the long side of C can also be absorbed, and the vibration resistance performance of the laminate A can be further improved.

<Third Embodiment>
In the fuel cell stack structure shown in FIG. 4, the reinforcing plates 58 </ b> A and 58 </ b> B as the second suppressing means have the curved substrate portion 11 and bulge outward at the continuous portion of the substrate portion 11 and the holding portion 12. The bent portion 13 is provided. The bent portion 13 of this embodiment has a C-shaped section that bulges outward. The reinforcing plates 58 </ b> A and 58 </ b> B have a spring property that presses the holding portions 12 and 12 against the laminated body A by the curved substrate portion 11 and the bent portion 13.

  Even in the fuel cell stack structure, as in the previous embodiment, the vibration resistance performance of the multilayer body A is enhanced by the reinforcing plates 58A and 58B as the second suppression means, and the binding force of the multilayer body A is increased for a long time. In particular, since the range of movement of the holding portion 12 to the outside is increased by the bent portion 13, there is an advantage that it is easy to attach to the laminate A.

<Fourth embodiment>
In the fuel cell stack structure shown in FIG. 5, the reinforcing plates 58A and 58B as the second restraining means have the substrate portion 11 having a convex curved surface shape. Further, one (left in the drawing) reinforcing plate 58A as the second suppressing means has a holding portion 12 formed in a curved surface shape. Further, the other reinforcing plate 58 </ b> B (the right side in the drawing) as the second suppressing means has a bent portion 14 that bulges outward at a continuous portion of the substrate portion 11 and the holding portion 12.

  Both holding portions 12 and 12 in one reinforcing plate 58A are formed in a curved shape whose front end portions open to the outside. Further, the bent portion 14 of the other reinforcing plate 58B has an angular cross section that bulges in the direction along the short side of the single cell C (the vertical direction in FIG. 5).

  Even in the fuel cell stack structure described above, as in the previous embodiment, the reinforcing plate (second suppressing means) 58A, 58B having the substrate portion 11, the holding portion 12, and the bent portion 14 can be used to form the laminate A. The vibration resistance can be improved and the binding force of the laminate A can be maintained for a long time. Further, one reinforcing plate 58A has an advantage that it can be easily attached to the laminated body A by the curved holding portion 12, and the other reinforcing plate 58B is movable to the outside of the holding portion 12 by the bent portion 13. Since the range becomes large, there is an advantage that it is easy to attach to the laminate A. In this embodiment, the reinforcing plates 58A and 58B having different configurations on the left and right are shown, but it is naturally possible to provide reinforcing plates having the same configuration on the left and right.

<Fifth Embodiment>
In the fuel cell stack structure shown in FIG. 6, the reinforcing plates 58A and 58B as the second suppressing means have the substrate portion 11 having a curved surface. Further, one reinforcing plate 58 </ b> A (left side in the drawing) as the second suppressing means has a bent portion 15 recessed inward in the vicinity of the tip end portion of the holding portion 12. Further, the other reinforcing plate 58B as the second suppressing means (right side in the figure) has a holding portion 12 formed in a wave shape.

  Even in the fuel cell stack structure described above, as in the previous embodiment, the reinforcing plate (second suppressing means) 58A, 58B having the substrate portion 11, the holding portion 12, and the bent portion 15 is used to withstand the durability of the laminate A. The vibration performance can be improved and the binding force of the laminate A can be maintained over a long period of time. Further, the one reinforcing plate 58A functions as a retaining member with the bent portion 15 engaged with the laminate A. Further, the other reinforcing plate 58B has an advantage that the movable portion of the holding portion 12 becomes larger and can be easily attached to the laminate A because the holding portion 12 has a wave shape. In this embodiment as well, the reinforcing plates 58A and 58B having different configurations on the left and right are shown as in the fourth embodiment, but it is naturally possible to provide reinforcing plates having the same configuration on the left and right.

  Further, the fuel cell stack structure according to the present invention has each part of the reinforcing plates 58A and 58B shown in the first to fifth embodiments shown in FIGS. 2 to 6, that is, the substrate part 11, the holding part 12, and the bent parts. The spring constants of the portions 13 to 15 may be different. Thereby, the appropriate press-contact force according to each part of the laminated body A can be set.

  In addition, the structure of the fuel cell stack according to the present invention is not limited only to the above-described embodiments, and the configurations of the respective embodiments may be combined or the members of the respective members may be combined without departing from the gist of the present invention. It is possible to change the material, shape, size, number, and the like.

A Stack C Single cell FS Fuel cell stack 11 Substrate part 12 Holding part 13 Bending part 14 Bending part 57A, 57B Fastening plate (first suppressing means)
58A, 58B Reinforcement plate (second suppression means)
61 Complementary spring mechanism 67 Fastening band (first suppression means)

Claims (7)

A laminate formed by stacking rectangular plate-shaped single cells;
A first suppressing means for restraining the stacked body in the stacking direction of the single cells and suppressing movement in a direction along one opposite side of the single cells;
A second suppression means for suppressing movement in a direction along the other opposite side of the single cells,
The first suppression means and the second suppression means constitute a case of the laminate,
The second suppressing means contacts the stacked end surface on the other opposite side of the stacked body continuously with the curved substrate portion covering the stacked end surface on the one opposite side of the stacked body and the both end portions of the substrate portion. a pair of holding portions, have a spring property to and pressed against the two holding portions in the laminated body,
The substrate portion of the second suppression means is formed in a curved shape protruding outward,
A fuel cell stack structure , wherein a gap is formed between the laminate and the substrate portion .   2. The fuel cell stack structure according to claim 1, wherein the single cell has a rectangular plate shape, the one opposite side is a short side, and the other opposite side is a long side. The fuel cell stack structure according to claim 1 or 2 , wherein the substrate portion of the second suppressing means is formed into a curved surface by performing shot peening. The fuel cell stack structure according to any one of claims 1 to 3 , wherein the second suppressing means has a bent portion that bulges outward in a continuous portion of the substrate portion and the holding portion. The fuel cell stack structure according to any one of claims 1 to 4 , wherein the holding portion of the second suppressing means is formed in a wave shape or a curved surface shape. The fuel cell stack structure according to any one of claims 1 to 5 , wherein the spring constants of the substrate portion and the holding portion in the second suppressing means are different. The fuel cell stack structure according to any one of claims 1 to 6 , further comprising a supplementary spring mechanism that absorbs vibrations of the multilayer body between the multilayer body and the substrate portion of the second suppressing means. .

Images