JP5129495B2 - Cell pressure assembly for fuel cell - Google Patents

Description

  The present invention relates to a cell pressing assembly for a fuel cell for pressing and fastening a cell stack of a fuel cell.

For example, in Patent Document 1 and Patent Document 2, a cell pressing assembly for a fuel cell including an input side plate, an output side plate, and a coil spring group (hereinafter, abbreviated as “cell pressing assembly” as appropriate). Has been introduced. The coil spring group is interposed between the input side plate and the output side plate. A load applied from the outside is transmitted to the cell stack of the fuel cell via the input side plate, the coil spring group, and the output side plate. The cell stack is configured by stacking a large number of plate-like cells. The cell stack is fastened by an external load transmitted through the output side plate.
JP 2004-288618 A JP 2006-114362 A

  By the way, in order to firmly fasten the cell stack, it is necessary to apply a relatively large load to the input side plate. However, if the input side plate is bent due to a large load, it is difficult to press the cell stack uniformly over the cell surface development direction. From this viewpoint, the input side plate is required to have high rigidity. For this reason, it is preferable that the plate thickness of the input side plate is large.

  However, as the plate thickness of the input side plate increases, the total length of the cell pressing assembly in the direction in which the load is applied (cell stacking direction) (hereinafter simply referred to as “total length” as appropriate) increases accordingly. . In this respect, from the viewpoint of reducing the installation space of the cell pressing assembly, the total length of the cell pressing assembly is required to be small.

  In order to satisfy such conflicting requirements, the present inventor has devised an input side plate having an accommodation recess. A plurality of receiving recesses are arranged on the pressing surface of the input side plate (surface on the cell laminate side). One end of the coil spring is housed in the housing recess. According to this input side plate, for example, the length of the cell pressing assembly is ensured while maintaining an equivalent stroke as compared with the case where a holding portion having a standing claw is provided on the pressing surface and one end of the coil spring is held by the holding portion. Can be reduced. And since the wall part between adjacent accommodating recessed parts acts as a rib, the input side plate can ensure desired rigidity.

  However, when an input side plate having an accommodation recess is used for the cell pressing assembly for a fuel cell, when a load is applied from the outside, stress may concentrate on a specific part. For this reason, the maximum stress (the maximum value of the maximum principal stress, the same shall apply hereinafter) may increase. Here, in order to reduce the maximum stress, it is necessary to change the shape of the input side plate. However, the rigidity of the input side plate may be lowered depending on the part and the degree of the shape change.

  The cell pressing assembly for a fuel cell according to the present invention has been completed in view of the above problems. Accordingly, an object of the present invention is to provide a cell pressing assembly for a fuel cell that can reduce the maximum stress of an input side plate while ensuring a desired rigidity.

  (1) In order to solve the above problems, a fuel cell cell pressing assembly according to the present invention is provided with an elastic body group composed of a plurality of elastic bodies and one end side of the elastic body group in the expansion and contraction direction, and a load is input from the outside. A cell stack composed of a plurality of stacked cells that are disposed on the other end side in the expansion and contraction direction of the elastic body group and output the load transmitted through the elastic body group. An output side plate for pressing, wherein the input side plate accommodates one end of the plurality of elastic bodies and has an opening area larger than the bottom area. A pressing surface having a plurality of large receiving recesses, a load portion to which the load is applied, and a maximum displacement portion that maximizes a displacement amount with respect to the load portion when the load is applied. The thickness is smaller than the average thickness of the maximum displacement part It is characterized by (corresponding to claim 1).

  The input side plate of the cell pressing assembly of the present invention has a pressing surface. A plurality of receiving recesses are arranged on the pressing surface. One end of the elastic body is housed in the housing recess. The receiving recess of the pressing surface has an opening and a bottom. The opening is substantially flush with the pressing surface. The bottom portion is disposed farthest from the opening in the depth direction. The area of the opening (specifically, the area in the direction substantially perpendicular to the depth direction of the housing recess, the same applies hereinafter) is larger than the area of the bottom. For this reason, when a load is applied, the compressed elastic body can be prevented from interfering with the housing recess due to swelling, bending, buckling, collapse, and the like.

  In addition, since the area of the opening is larger than the area of the bottom, focusing on the wall between any pair of adjacent housing recesses, the distance between the openings in the wall (hereinafter referred to as “thickness between openings” as appropriate). Is smaller than the distance between the bottoms (hereinafter referred to as “thickness between the bottoms” as appropriate). Therefore, when a load is applied from the outside, a maximum stress is generated in a portion between the openings of the wall portion.

  In this regard, according to the cell pressing assembly of the present invention, the average plate thickness of the load portion is smaller than the average plate thickness of the maximum displacement portion. If the plate thickness is small, the depth of the accommodating recess is reduced accordingly. For this reason, compared with the case where plate | board thickness is large, the thickness between opening parts becomes large (that is, it becomes thick). That is, the thickness between the opening portions of the accommodating concave portion disposed in the load portion (specifically, the region disposed in the load portion of the pressing surface) increases. Therefore, compared with the case where the plate | board thickness of an input side plate is constant, it is the site | part between opening parts in the wall part of the accommodation recessed part arrange | positioned at a load part (henceforth a site | part between opening parts suitably). The maximum stress generated can be reduced. Thus, according to the cell pressing assembly of the present invention, the maximum stress generated in the portion between the openings can be reduced in the load portion.

  On the other hand, the average plate thickness of the maximum displacement portion is larger than the average plate thickness of the load portion. For this reason, when a load is applied, the maximum displacement portion is hardly deformed. Therefore, according to the input side plate of the cell pressing assembly of the present invention, a desired rigidity can be ensured even though the average plate thickness of the load portion is small.

  (2) Preferably, in the configuration of (1), the input side plate includes a central portion including the load portion and a peripheral portion including the maximum displacement portion, and an average plate thickness of the central portion is It is better to have a configuration smaller than the average thickness of the peripheral portion (corresponding to claim 2).

  According to this configuration, the maximum stress generated in the portion between the openings can be reduced in the central portion. On the other hand, since the average plate thickness of the peripheral portion is larger than the average plate thickness of the central portion, the input side plate can ensure desired rigidity.

  (2-1) Preferably, in the configuration of (2) above, the central portion and the peripheral portion are preferably connected in a slope shape (inclined surface shape) on the pressing surface. If it carries out like this, compared with the case where a center part and a peripheral part are connected in the step shape (step shape) in a press surface, the stress concentration at the time of applying a load can be suppressed.

  (3) Preferably, in the configuration of the above (2), the boundary between the central portion and the peripheral portion is set such that the displacement amount of the maximum displacement portion with respect to the load portion is 100%, and the displacement amount is 5% or more and 100 It is better to set it as the range set to the% or less (corresponding to claim 3).

  FIG. 1A shows a schematic cross-sectional view of the input side plate before a load is applied. FIG. 1B shows a schematic cross-sectional view of the input side plate when a load is applied. FIG. 1 is a diagram illustrating the operation of the cell pressing assembly of the present invention for the sake of convenience. The shape of the input side plate of the present invention, the method of adding an external load, the number of load portions, and the shape It does not limit anything.

  The boundary between the central part and the peripheral part is set as follows. As shown in FIG. 1A, the input side plate 109 has a load portion 110 and a maximum displacement portion 111 (shown by a thick line). A plurality of receiving recesses (not shown) are disposed on the pressing surface 112 of the input side plate 109.

  As shown in FIG. 1B, when a load is applied to the load portion 110 by the rod 115, the maximum displacement portion 111 of the input side plate 109 warps in the direction in which the load is applied starting from the load portion 110. Displace as follows. This displacement is set to 100%. In this example, the boundary B0 is set based on the displacement amount B1% within a range where the displacement amount is A1 (= 5)% or more and 100% or less. A portion including the load portion 110 across the boundary B0 is defined as a central portion 113. In addition, a portion including the maximum displacement portion 111 across the boundary B0 is defined as a peripheral portion 114. Thus, the boundary is set based on the amount of displacement when a load is applied.

  Here, the reason why the boundary position is set to 5% or more is that when it is less than 5%, the peripheral part becomes large (the central part becomes small), and the area where the thickness between the openings is small on the pressing surface becomes large. It is. That is, it is easy to ensure the desired rigidity, but the region where the maximum stress generated in the portion between the openings is small is small.

  (4) Preferably, in any one of the configurations (1) to (3), the elastic body is a coil spring (corresponding to claim 4). According to this configuration, a desired fastening load can be applied to the cell stack by adjusting the coil diameter and length of the coil spring.

  (5) Moreover, in order to solve the said subject, the cell press assembly of this invention is arrange | positioned at the elastic body group which consists of several elastic bodies, and the expansion-contraction direction one end side of this elastic body group, and a load is input from the outside. The input side plate and the elastic body group are arranged on the other end side in the expansion / contraction direction, and the load transmitted through the elastic body group is output to press the cell laminated body composed of a plurality of laminated cells. An output side plate, and a fuel cell cell pressing assembly, wherein the input side plate has a pressing surface having a plurality of receiving recesses in which one end portions of the plurality of elastic bodies are stored, The pressing surface has a load region to which the load is applied from the back side, and among the accommodating recesses arranged in the load region, at least a part of the opening of the accommodating recess is a substantially polygonal polygonal opening. It is a part and is arranged in a region other than the load region Among the receiving recesses, at least a part of the opening of the receiving recess is a substantially perfect circular opening, and the area of the polygonal opening is larger than the area of the perfect opening and is adjacent. The linear portions of the polygonal opening are arranged so as to be substantially parallel to each other (corresponding to claim 5).

  FIG. 2A shows a schematic view of a pair of adjacent perfect circular openings as viewed from above the pressing surface. FIG. 2B shows a schematic view of a pair of adjacent polygonal openings as viewed from above the pressing surface. FIG. 2 is a diagram illustrating the operation of the cell pressing assembly of the present invention for the sake of convenience, and limits the shape of the perfect circular opening or the polygonal opening of the present invention, the distance between the openings, and the like. Not what you want.

  As shown in FIG. 2 (a), when the opening is a perfect circle opening 100, the portion 101 between the openings (indicated by a left-upward hatching) is a pair of semicircles when viewed from above the pressing surface 102. It is shaped like a back-to-back arrangement. For this reason, the part where the thickness between the openings is the smallest is only the part P1 (indicated by a thick line) on the straight line L1 connecting the centroids (centers) of the adjacent perfect circular openings 100. When a load is applied, stress is locally concentrated on the part P1. For this reason, the maximum stress increases.

  On the other hand, as shown in FIG. 2B, when the opening is a polygonal (substantially regular hexagonal) opening 103, the linear portions L2 of the polygonal opening 103 are substantially parallel to each other. Are arranged as follows. For this reason, the portion 104 between the openings (shown by left-upward hatching) is a portion P2 (shown by cross-hatching) in which the pair of straight portions L2 are arranged back to back as viewed from above the pressing surface 105. have. In the said site | part P2, the thickness between opening parts becomes the minimum. The part P2 extends to the part 104 between the openings over the entire length of the straight part L2 of the polygonal opening 103. For this reason, when the polygonal opening 103 is arranged, stress concentration when a load is applied can be suppressed. Therefore, the maximum stress can be reduced.

  On the other hand, the area of the polygonal opening 103 is larger than the area of the perfect circular opening 100 (indicated by a one-dot chain line circle in FIG. 2B). For this reason, the thickness between the openings between the perfect circular openings 100 is larger than the thickness between the openings between the polygonal openings 103. Therefore, the portion corresponding to the perfect circular opening 100 in the input side plate has higher rigidity than the portion corresponding to the polygonal opening 103.

  According to the cell pressing assembly of the present invention, the opening of the receiving recess disposed in the load region is a polygonal opening. On the other hand, the opening part of the accommodation recessed part arrange | positioned in areas other than a load area | region is a perfect circle opening part. For this reason, in a load area | region, the maximum stress which generate | occur | produces in the site | part between openings can be made small by suppressing stress concentration. In addition, since the thickness between the openings in the region other than the load region is large, the input side plate can ensure desired rigidity.

  (6) Preferably, in the configuration of the above (5), the polygonal opening may have a substantially regular hexagonal shape in which adjacent linear portions are connected via a curved portion. (Corresponding to claim 6).

  In order to reduce the overall length of the cell pressing assembly while ensuring a desired fastening load, shorten the length of the elastic body interposed between the input side plate and the output side plate and increase the number of arrangements. Is preferred. If it is going to arrange | position an elastic body densely, arbitrary one accommodation recessed parts will be surrounded by the other six accommodation recessed parts in a press surface, and will adjoin. That is, one receiving recess is adjacent to another receiving recess in six directions.

  In this regard, according to the present configuration, the polygonal opening has a substantially regular hexagonal shape. For this reason, a linear part can be arrange | positioned in six directions. Therefore, even if the elastic bodies are densely arranged, stress concentration can be suppressed in the load region. That is, the maximum stress generated at the site between the openings can be reduced. In addition, since the thickness between the openings in the region other than the load region is large, the input side plate can ensure desired rigidity.

  (6-1) Preferably, in the configuration of (5) above, the polygonal opening should have a substantially square shape in which adjacent straight portions are connected via a curved portion. . According to this structure, a linear part can be arrange | positioned in four directions. Therefore, even if any one accommodating recess is adjacent to and surrounded by the other four accommodating recesses, stress concentration can be suppressed in the load region. That is, the maximum stress generated at the site between the openings can be reduced. In addition, since the thickness between the openings in the region other than the load region is large, the input side plate can ensure desired rigidity.

  (7) Preferably, in the configuration of (5) or (6) above, the area of the opening of the receiving recess is preferably larger than the area of the bottom of the receiving recess (corresponding to claim 7). ). According to this configuration, when a load is applied, the compressed elastic body can be prevented from interfering with the housing recess due to swelling, bending, buckling, collapse, and the like.

  (8) Preferably, in any one of the configurations (5) to (7), the elastic body is a coil spring (corresponding to claim 8). According to this configuration, a desired fastening load can be applied to the cell stack by adjusting the coil diameter and length of the coil spring.

  (9) Moreover, in order to solve the said subject, the cell press assembly of this invention is arrange | positioned at the elastic body group which consists of several elastic bodies, and the expansion-contraction direction one end side of this elastic body group, and the input which applies a load from the outside A side plate, and an output side plate that is disposed on the other end side in the expansion and contraction direction of the elastic body group, and that presses the cell stack composed of a plurality of stacked cells by the load transmitted through the elastic body group. The input side plate has a pressing surface with a plurality of receiving recesses in which one end portions of the plurality of elastic bodies are stored, and the pressing surface is Of the surrounding area formed by connecting the centers of gravity of the openings of the three or more adjacent receiving recesses including the receiving recesses disposed in the load area, the load area to which the load is applied from the back side, At least some of the recesses between the openings are arranged. Is characterized in that is (corresponding to claim 9).

  FIG. 3 shows a schematic view of three adjacent openings as viewed from above the load area of the pressing surface. FIG. 3 is a diagram illustrating the operation of the cell pressing assembly of the present invention for the sake of convenience, and limits the shape of the opening of the present invention, the number of adjacent openings, the distance between the openings, and the like. Not what you want.

  As shown in FIG. 3, if the opening is a perfect circle, the portion where the thickness between the openings is minimum connects the centers of gravity G1 of the adjacent openings 106 as in FIG. Only the portion P3 (shown by a thick line) on the straight line L3. When a load is applied, stress is locally concentrated on the part P3. For this reason, the maximum stress increases.

  In this respect, the opening-to-opening recess 107 (indicated by the right-up hatching) is disposed in at least a part of the surrounding region r0 (indicated by the alternate long and short dash line) formed by connecting the centers of gravity G1 of the cell pressing assembly of the present invention. Has been. When the recess 107 between the openings is arranged, the height of the wall between the receiving recesses is reduced accordingly. For this reason, the stress which concentrates on the site | part P3 can be released to the recessed part 107 between opening parts. Therefore, in the load region 108, the maximum stress generated at the site between the openings can be reduced.

  On the other hand, when the adjacent accommodation recesses are all disposed in a region other than the load region, the inter-opening recesses are not disposed. For this reason, the rigidity of the input side plate can be ensured by an area other than the load area.

  (10) Preferably, in the configuration of the above (9), the surrounding region should have a triangular shape (corresponding to claim 10). In order to reduce the overall length of the cell pressing assembly while ensuring a desired fastening load, shorten the length of the elastic body interposed between the input side plate and the output side plate and increase the number of arrangements. Is preferred. If it is going to arrange | position an elastic body densely, arbitrary one accommodation recessed parts will be surrounded by the other six accommodation recessed parts in a press surface, and will adjoin. For this reason, the surrounding region has a triangular shape as in this configuration.

  According to this configuration, even if the elastic bodies are densely arranged, stress concentration can be suppressed in the load region. That is, the maximum stress generated at the site between the openings can be reduced. In addition, the rigidity of the input side plate can be ensured by an area other than the load area.

  (10-1) Preferably, in the configuration of the above (9), it is better that the surrounding region has a quadrangular shape. According to this configuration, even if any one accommodating recess is adjacent to and surrounded by the other four accommodating recesses, stress concentration can be suppressed in the load region. That is, the maximum stress generated at the site between the openings can be reduced. In addition, the rigidity of the input side plate can be ensured by an area other than the load area.

  (11) Preferably, in the configuration of (9), one of the surrounding regions arranged in the center of the load region has a hexagonal shape, and the other has a triangular shape, and has a hexagonal shape. Of the triangular surrounding regions, at least the hexagonal surrounding region is preferably provided with the inter-opening recesses (corresponding to claim 11).

  In order to reduce the overall length of the cell pressing assembly while ensuring a desired fastening load, shorten the length of the elastic body interposed between the input side plate and the output side plate and increase the number of arrangements. Is preferred. If it is going to arrange | position an elastic body densely, arbitrary one accommodation recessed parts will be surrounded by the other six accommodation recessed parts in a press surface, and will adjoin. For this reason, the surrounding region has a triangular shape.

  However, it is difficult to secure a desired rigidity if the accommodating recess is arranged at the center of the load region. Therefore, the present configuration does not dare to place an accommodation recess at the center of the load region. In the center of the load area, a large hexagonal surrounding area is arranged instead of the accommodating recess. Moreover, the large recessed part between opening parts is arrange | positioned in the said surrounding area | region. Then, a triangular surrounding region is arranged around a large hexagonal surrounding region.

  According to this configuration, stress concentration can be suppressed in the load region. That is, the maximum stress generated at the site between the openings can be reduced. Moreover, the rigidity of the input side plate can be ensured by not intentionally arranging the accommodation recess at the center of the load region.

  (12) Preferably, in the configuration of the above (11), the opening forming the hexagonal surrounding region of the opening of the receiving recess is compared to the case where the opening is a perfect circle. The center end of the opening that is closest to the center of the load region is preferably configured to have a deformed circular shape arranged so as to be closer to the center of the load region. Correspondence).

  According to this configuration, stress concentration in the load region can be further suppressed. That is, the maximum stress generated in the portion between the openings can be further reduced.

  (13) Preferably, in any one of the configurations (9) to (12), the area of the opening of the receiving recess is larger than the area of the bottom of the receiving recess. 13). According to this configuration, when a load is applied, the compressed elastic body can be prevented from interfering with the housing recess due to swelling, bending, buckling, collapse, and the like.

  (14) Preferably, in any one of the configurations (9) to (13), the elastic body is a coil spring (corresponding to claim 14). According to this configuration, a desired fastening load can be applied to the cell stack by adjusting the coil diameter and length of the coil spring.

  ADVANTAGE OF THE INVENTION According to this invention, the cell press assembly for fuel cells which can make small the maximum stress of an input side plate can be provided, ensuring desired rigidity.

  Embodiments of a fuel cell cell pressing assembly according to the present invention will be described below.

<First embodiment>
(Configuration of fuel cell)
First, the structure of the fuel cell in which the cell pressing assembly of this embodiment is assembled will be described. FIG. 4 shows a side view of a polymer electrolyte fuel cell in which the cell pressing assembly of this embodiment is assembled. Note that the orientations in the drawings after FIG. 4 are set for convenience of explanation, and do not limit the arrangement direction of the polymer electrolyte fuel cell and the cell pressing assembly.

  As shown in FIG. 4, the polymer electrolyte fuel cell 9 includes a cell pressing assembly 1, a cell stack 8, a pair of insulating plates 91a and 91b, a pair of terminal plates 92a and 92b, and a pair of end plates. 90a, 90b, a pair of restraining plates 93a, 93b, a pair of tension plates 94a, 94b, and a pair of adjusting rods 6a, 6b.

  Each of the pair of end plates 90a and 90b is made of an aluminum alloy and has a rectangular plate shape. The pair of end plates 90a and 90b are arranged to face each other in parallel with a predetermined distance apart in the stacking direction (vertical direction) of the cell stack 8 to be described later. The end plate 90a is formed with a pair of adjusting rod through holes 900a and 900b (shown in cross section in FIG. 4) spaced apart from each other by a predetermined distance in the left-right direction. Thread grooves (not shown) are formed on the inner peripheral surfaces of the adjusting rod through holes 900a and 900b, respectively.

  Each of the pair of tension plates 94a and 94b is made of an aluminum alloy and has a rectangular plate shape. The pair of tension plates 94a and 94b are arranged to face each other in parallel with a predetermined distance in the left-right direction. The pair of tension plates 94a and 94b and the pair of end plates 90a and 90b are connected so as to form a rectangular frame as a whole.

  The cell pressing assembly 1, the cell stack 8, the pair of insulating plates 91a and 91b, the pair of terminal plates 92a and 92b, the pair of restraining plates 93a and 93b, and the pair of adjusting rods 6a and 6b are accommodated in the rectangular frame. ing.

  The cell stack 8 is formed by stacking a large number of cells 80. The cell 80 is formed by sandwiching an MEA (electrolyte membrane electrode assembly, not shown) between separators (not shown). The cell 80 has a thin plate shape.

  Each of the pair of terminal plates 92a and 92b is made of copper and has a rectangular plate shape. The terminal plate 92a is disposed above the cell stack 8, and the terminal plate 92b is disposed below the cell stack 8.

  Each of the pair of insulating plates 91a and 91b is made of insulating resin and has a rectangular plate shape. The insulating plate 91a is disposed above the terminal plate 92a, and the insulating plate 91b is disposed below the terminal plate 92b.

  Each of the pair of restraint plates 93a and 93b is made of urethane foam and has a rectangular plate shape. The restraint plate 93a is disposed on the left side of the cell stack 8, and the restraint plate 93b is disposed on the right of the cell stack 8.

  The adjusting rods 6a and 6b are made of steel and have a round bar shape. Screw threads are formed on the outer peripheral surfaces of the adjusting rods 6a and 6b. The adjusting rod 6a is inserted into the adjusting rod through hole 900a. The thread of the adjusting rod 6a is screwed with the thread groove of the adjusting rod through hole 900a. By turning the adjusting rod 6a, the screwing amount L of the adjusting rod 6a can be adjusted. Similarly, the adjustment rod 6b is inserted into the adjustment rod through hole 900b. The thread of the adjusting rod 6b is screwed with the thread groove of the adjusting rod through hole 900b. By turning the adjusting rod 6b, the screwing amount L of the adjusting rod 6b can be adjusted.

  The cell pressing assembly 1 is interposed between the end plate 90a and the insulating plate 91a. Further, the cell pressing assembly 1 is separated from the end plate 90a by the screwing amount L of the adjusting rods 6a and 6b.

(Configuration of cell pressing assembly)
Next, the configuration of the cell pressing assembly of this embodiment will be described. FIG. 5 shows a perspective combined view of the cell pressing assembly of this embodiment. FIG. 6 shows an exploded perspective view of the cell pressing assembly. As shown in FIGS. 5 and 6, the cell pressing assembly 1 includes an input side plate 2, an output side plate 4, a spring group 3, and a guide plate 5.

  The spring group 3 includes a large number of coil springs 30 made of spring steel. The spring group 3 is included in the elastic body group of the present invention. A large number of coil springs 30 are regularly arranged. The vertical projection surface of the coil spring 30 has a perfect circular shape.

  The input side plate 2 is made of an aluminum alloy and has a rectangular plate shape. The input side plate 2 is disposed above the spring group 3. A pair of rod receiving members 28 a and 28 b are disposed on the upper surface of the input side plate 2. Each of the rod receiving members 28a and 28b is made of steel and has a disk shape with a slightly raised center. The rod receiving members 28a and 28b are fixed to the upper surface of the input side plate 2 by screws. The adjusting rod 6a shown in FIG. 4 contacts the rod receiving member 28a, and the adjusting rod 6b shown in FIG. 4 contacts the rod receiving member 28b. Guide rod through holes 21 are formed in the vicinity of the four corners of the input side plate 2. The guide rod through hole 21 has a stepped cylindrical shape whose diameter decreases from the upper side to the lower side. The input side plate 2 will be described in detail later.

  The output side plate 4 is made of an aluminum alloy and has a rectangular plate shape. The output side plate 4 is disposed below the spring group 3. The upper surface 46 of the output side plate 4 has a substantially planar shape. A large number of output side recesses 40 are formed on the upper surface 46. The output-side recess 40 is disposed so as to correspond to each of the multiple coil springs 30. The output side recess 40 has a perfect circle shape. The output-side recess 40 houses the lower end of the coil spring 30. Guide rod fixing holes 42 are formed in the vicinity of the four corners of the output side plate 4. A thread groove (not shown) is formed on the inner peripheral surface of the guide rod fixing hole 42. Further, three bolt fixing recesses 41 are provided in the vicinity of the front and rear edges of the output side plate 4, respectively.

  The guide plate 5 is made of an aluminum alloy and has a rectangular thin plate shape. The guide plate 5 is fixed to the upper surface 46 of the output side plate 4. The guide plate 5 is provided with a number of perfect circular coil spring holding holes 50. The coil spring holding hole 50 is disposed so as to correspond to each of the multiple coil springs 30. The coil spring 30 is disposed in the coil spring holding hole 50 so as to penetrate in the vertical direction. Three bolt through holes 51 are formed near the front and rear edges of the guide plate 5. The bolt 45 passes through the bolt through hole 51 from the top to the bottom and is screwed into the bolt fixing recess 41. That is, the guide plate 5 is fixed to the upper surface 46 of the output side plate 4 by the bolts 45.

  Nut fastening holes 52 are formed in the vicinity of the four corners of the guide plate 5. The forward guide rod through hole 21, the nut fastening hole 52, and the forward guide rod fixing hole 42 are arranged in a line in the vertical direction. A guide rod 43 is inserted into these three holes from the top to the bottom. More specifically, the guide rod 43 is made of steel and has a bolt shape. A thread is formed on the outer peripheral surface below the shaft portion of the guide rod 43. The lower end of the guide rod 43 passes from the upper side to the lower side through the guide rod through hole 21 of the input side plate 2, the nut fastening hole 52 of the guide plate 5, and the guide rod fixing hole 42 of the output side plate 4. It is fixed to. Specifically, the screw rod of the guide rod 43 and the screw groove of the guide rod fixing hole 42 are screwed together, whereby the lower end of the guide rod 43 is accommodated and fixed in the guide rod fixing hole 42. Further, a nut 44 is screwed onto an upper portion of the nut fastening hole 52 on the outer peripheral surface of the shaft portion of the guide rod 43. The nut 44 regulates the screwing amount of the lower end of the guide rod 43 with respect to the guide rod fixing hole 42. The head portion of the guide rod 43 is disposed above the step of the guide rod through hole 21 of the input side plate 2. Separation of the input side plate 2 and the output side plate 4 is suppressed by the head of the guide rod 43 being caught by the step.

  In the state where the cell pressing assembly 1 is assembled to the polymer electrolyte fuel cell 9 (see FIG. 4), the adjustment rods 6a and 6b are connected to the input side plate 2 via the rod receiving members 28a and 28b. A load is applied. The input side plate 2 moves downward (in the direction of the output side plate 4) while compressing the spring group 3 by the load. The output side plate 4 is urged downward (in the direction of the cell stack 8) by the spring group 3 and presses the cell stack 8. In this way, a fastening load is applied to the cell stack 8.

(Detailed configuration of input side plate)
Next, the configuration of the input side plate of the cell pressing assembly of this embodiment will be described in detail. In FIG. 7, the perspective view of the input side plate of the cell press assembly of this embodiment is shown. FIG. 8 shows a bottom view of the input side plate. FIG. 9 shows a cross-sectional view in the IX-IX direction of FIG. FIG. 10 is a sectional view taken along the line XX of FIG. In addition, the input side plate 2 shown in FIG. 7 is the input side plate 2 of FIG. 6 turned upside down around the axis L4 (see the azimuth in the figure).

  As shown in FIGS. 7 to 10, the entire lower surface of the input side plate 2 is a pressing surface 26 for pressing the spring group 3 (see FIG. 6). Further, the input side plate 2 includes a central portion R3 and a peripheral portion R4 (however, the input side plate 2 itself is an integral part). In FIG. 8, a boundary B2 between the central portion R3 and the peripheral portion R4 is indicated by a one-dot chain line.

  The central portion R3 has a rectangular plate shape. Of the pressing surface 26, a portion corresponding to the central portion R3 has a concave surface shape (conical shape) that is gently recessed upward. The central portion R3 has a pair of left and right load portions R1 (shown by dotted lines in FIG. 8). Each of the pair of load portions R1 has a short-axis columnar shape. The rod receiving members 28a and 28b are respectively disposed on the upper surfaces of the pair of load portions R1 (see FIG. 4). That is, a load is directly applied to the pair of load portions R1 from the adjusting rods 6a and 6b via the rod receiving members 28a and 28b. A load region r1 is disposed in a portion of the pressing surface 26 corresponding to the load portion R1. Therefore, a load is applied to the load region r1 from the back side (upper surface side).

  The peripheral portion R4 has a rectangular frame shape. The peripheral portion R4 is disposed around the central portion R3. The peripheral portion R4 has a pair of left and right maximum displacement portions R2 (indicated by bold lines in FIGS. 8 and 10). The pair of left and right maximum displacement portions R <b> 2 correspond to the left and right edges of the input side plate 2. When a load is applied to the load portion R1 from the rod receiving members 28a and 28b (see FIG. 4), the input side plate 2 is deformed so as to be warped up with the load portion R1 as a base point. At this time, the warp amount (displacement amount) of the maximum displacement portion R2 becomes the maximum in the entire input side plate 2.

  A large number of input side recesses 22 are formed on the pressing surface 26. The input side recess 22 is included in the housing recess of the present invention. The multiple input side recesses 22 are arranged to correspond to the multiple coil springs 30 (see FIG. 6). The upper end of the coil spring 30 is accommodated in the input-side recess 22. That is, the coil spring 30 is accommodated in the input side plate 2 and the output side by accommodating the upper end in the input side recess 22, the lower end in the output side recess 40, and the body portion near the lower end in the coil spring holding hole 50. It is held between the plates 4.

  Many input side recessed parts 22 are arrange | positioned regularly over the whole surface of the press surface 26. As shown in FIG. More specifically, the plurality of input-side recesses 22 form a large number of rows that are separated by a predetermined interval and are arranged in the front-rear direction. A large number of the rows are arranged in parallel in the left-right direction. Here, in order to increase the number of the input-side recesses 22 arranged, the input-side recesses 22 between adjacent rows are arranged so as not to line up in a row in the left-right direction (so as to be staggered). For this reason, the arbitrary input-side recess 22 is surrounded by the six input-side recesses 22.

  FIG. 11 shows an enlarged view near the load region r1 in FIG. As shown in FIGS. 8 and 11, the input-side recess 22 arranged in the load region r <b> 1 has a substantially regular hexagonal shape. That is, the input-side recess 22 in the load region r1 includes a hexagonal opening 220a and a hexagonal bottom 221a. The hexagonal opening 220a is included in the polygonal opening of the present invention. The area of the hexagonal opening 220a is larger than the area of the hexagonal bottom 221a.

  On the other hand, the input side recessed part 22 arrange | positioned in the area | regions other than the load area | region r1 at least in part is exhibiting perfect circle shape. That is, the input-side recess 22 outside the load region r1 includes a perfect circle opening 220b and a perfect circle bottom 221b. The area of the perfect circle opening 220b is larger than the area of the perfect circle bottom 221b. The outer diameter of the coil spring 30 (see FIG. 6) is the same as or slightly smaller than the inner diameter of the perfect circle bottom 221b. In addition, all the output side recessed parts 40 of the output side plate 4 are also exhibiting the same shape as the said input part recessed part 22 of the perfect circle shape.

  FIG. 12 shows an enlarged view of the input-side recess in the load region r1. As shown in FIG. 12, the hexagonal opening 220a includes six straight portions 220c and six curved portions 220d. These straight portions 220c and curved portions 220d are alternately connected to form a hexagonal opening 220a. The area of the hexagonal opening 220a is larger than the area of the perfect circular opening 220b (indicated by a one-dot chain line in FIG. 12). The perfect circle opening 220b corresponds to an inscribed circle of the hexagonal opening 220a. Similarly, the area of the hexagonal bottom portion 221a is larger than the area of the perfect circle bottom portion 221b (indicated by a one-dot chain line in FIG. 12). The perfect circle bottom 221b corresponds to the inscribed circle of the hexagonal bottom 221a.

  Returning to FIG. 11, a large number of inter-opening recesses 223 (shown by hatching) are arranged in the load region r1. Each of the recesses 223 between the openings is disposed in the surrounding region r2 (indicated by a one-dot chain line). The surrounding region r2 is formed by connecting the centers of gravity of three adjacent openings (a general term for the hexagonal opening 220a and the perfect circular opening 220b; the same shall apply hereinafter), and has a triangular shape. The center of gravity of the recess 223 between the openings and the center of gravity of the surrounding region r2 are coincident with each other.

  FIG. 13 shows an enlarged perspective view of the vicinity of the concave portion on the input side arranged at the center of the load region r1 in FIG. As shown in FIG. 13, the inter-opening recess 223 is disposed at a site where three wall portions 222 between the pair of input-side recesses 22 converge. The inter-opening recess 223 has a partial “back” spherical shape as indicated by a one-dot chain line in the drawing.

  FIG. 14 shows an enlarged view in the frame XIV of FIG. As shown in FIGS. 9 and 14, the input side recess 22 has a vertical cross-sectional shape that tapers from the opening toward the bottom (generic name for the hexagonal bottom 221a and the perfect circle bottom 221b; the same applies hereinafter). Presents. The opening is continuous with the pressing surface 26. Further, the vertical position of the bottom is all constant.

  The minimum thickness T3 of the central portion R3 is set to be smaller than the thickness T4 of the peripheral portion R4. For this reason, the average plate thickness of the central portion R3 is smaller than the average plate thickness (= T4) of the peripheral portion R4. Therefore, paying attention to any pair of adjacent input-side recesses 22, the wall portion 222 between the pair of input-side recesses 22 becomes lower when the plate thickness of the input-side plate 2 is smaller. When the height of the wall portion 222 is lowered, the distance between the top surfaces of the wall portion 222 (the thickness between the openings in the horizontal direction) is increased. That is, the inter-opening thickness t3 of the central portion R3 is larger than the inter-opening thickness t4 of the peripheral portion R4.

(Operation effect of cell pressing assembly)
Next, the effect of the cell pressing assembly of this embodiment will be described. The input-side recess 22 and the output-side recess 40 of the cell pressing assembly 1 of the present embodiment have a tapered shape that narrows from the opening toward the bottom. For this reason, when a load is applied, the compressed coil spring 30 can be prevented from interfering with the input side recess 22 or the output side recess 40 due to swelling, bending, buckling, collapse, or the like. .

  By the way, if the input side recessed part 22 is exhibiting the taper shape, the thickness between opening parts will become smaller than the thickness between bottom parts. For example, as shown in FIG. 14, the wall 222 between the adjacent input side recesses 22 gradually becomes thinner from the hexagonal bottom 221a toward the hexagonal opening 220a. For this reason, when a load is applied from the outside, the maximum stress is generated in the portion between the openings.

  In this respect, according to the input side plate 2 of the cell pressing assembly 1 of the present embodiment, the average plate thickness of the central portion R3 is smaller than the average plate thickness (= T4) of the peripheral portion R4. For this reason, the inter-opening thickness t3 of the central portion R3 is larger than the inter-opening thickness t4 of the peripheral portion R4. Therefore, the maximum stress generated at the site between the openings can be reduced.

  On the other hand, the average plate thickness (= T4) of the peripheral portion R4 is larger than the average plate thickness of the central portion R3. For this reason, when a load is applied, the peripheral portion R4 is not easily displaced. Therefore, according to the input side plate 2 of the cell pressing assembly 1 of the present embodiment, a desired rigidity can be ensured although the average plate thickness of the central portion R3 is small.

  Further, according to the input side plate 2 of the cell pressing assembly 1 of the present embodiment, as shown in FIGS. 9 and 10, the central portion R3 and the peripheral portion R4 are connected in a gentle slope shape on the pressing surface 26. ing. Specifically, the lower surface of the flat peripheral portion R4, the flat inclined surface, and the lower surface of the flat central portion R3 are connected via a rounded chamfered curved surface. For this reason, compared with the case where center part R3 and surrounding part R4 are continued in a step shape, the stress concentration at the time of applying a load can be suppressed.

  In addition, according to the input side plate 2 of the cell pressing assembly 1 of the present embodiment, the boundary B2 between the central portion R3 and the peripheral portion R4 has a displacement amount of 100% as the displacement amount of the maximum displacement portion R2 with respect to the load portion R1. The region is set to 5%. For this reason, it is possible to reduce the maximum stress generated in the portion between the openings while ensuring the desired rigidity.

  Further, according to the cell pressing assembly 1 of the present embodiment, as shown in FIGS. 4 to 6, the coil spring 30 is used as the elastic body of the present invention. For this reason, a desired fastening load can be applied to the cell stack 8 by adjusting the coil diameter, length, and the like of the coil spring 30.

  Further, according to the input side plate 2 of the cell pressing assembly 1 of the present embodiment, as shown in FIG. 11, the input side concave portion 22 arranged in the load region r1 includes a hexagonal opening 220a. Further, as shown in FIG. 12, the hexagonal opening 220a includes six straight portions 220c. Here, between the adjacent hexagonal openings 220a, the linear portions 220c are arranged in parallel to each other. For this reason, it can suppress that stress concentrates locally in the specific location of the site | part between opening parts. Therefore, the maximum stress generated in the portion between the openings can be reduced. The hexagonal opening 220a includes six curved portions 220d. For this reason, compared with the case where the linear parts 220c are directly connected not via the curved part 220d, stress concentration can be suppressed.

  On the other hand, the input-side recess 22 arranged in a region other than the load region r1 includes a perfect circular opening 220b. For this reason, the thickness between the openings in the region other than the load region r1 is large. Therefore, since the effect of ensuring rigidity as a rib is great, the input side plate 2 can ensure desired rigidity.

  Further, according to the input side plate 2 of the cell pressing assembly 1 of the present embodiment, as shown in FIG. 11, the inter-opening recesses 223 are arranged in each of the multiple surrounding regions r2 in the load region r1. ing. As shown in FIG. 13, since the portion where the recess 223 between the openings is disposed is depressed from the surface of the pressing surface 26, the height of the wall 222 is reduced accordingly. For this reason, the local concentration of the stress distribution in the wall portion 222 can be released in the direction of the recess 223 between the openings. Therefore, the maximum stress generated at the site between the openings in the load region r1 can be reduced.

  On the other hand, when the adjacent input-side recesses 22 are all disposed in a region other than the load region r1, the inter-opening recess 223 is not disposed. For this reason, the rigidity of the input side plate 2 can be ensured.

  Further, according to the cell pressing assembly 1 of the present embodiment, since the input-side recess 22 and the output-side recess 40 are formed, both ends of the coil spring 30 are accommodated in the input-side recess 22 and the output-side recess 40. Thus, the coil spring 30 can be easily positioned.

  Further, the coil spring 30 is firmly held by the input side recess 22, the output side recess 40 and the coil spring holding hole 50. Accordingly, it is possible to suppress the displacement of the coil spring 30 when the cell pressing assembly 1 is conveyed or used.

  Further, according to the cell pressing assembly 1 of the present embodiment, one coil spring 30 is accommodated in the pair of the input-side recess 22 and the output-side recess 40. For this reason, even when many coil springs 30 are arranged, the individual coil springs 30 can be positioned without interfering with each other.

  Moreover, in the cell pressing assembly 1 of this embodiment, members made of aluminum alloy such as the input side plate 2, the output side plate 4, the guide plate 5 and the like are frequently used. Therefore, it is possible to reduce the weight of the cell pressing assembly 1 and thus the polymer electrolyte fuel cell 9. Furthermore, the cell pressing assembly 1 of the present embodiment is modularized by an input side plate 2 and an output side plate 4 that are connected to each other so that an elastic force is generated in the spring group 3. For this reason, it is possible to easily manufacture and replace the polymer electrolyte fuel cell 9.

  In the cell pressing assembly 1 of this embodiment, the guide plate 5 is disposed on the output side plate 4. By arranging the guide plate 5, the tilting of the coil spring 30 can be restricted when the cell pressing assembly 1 is assembled, and the attachment of the coil spring 30 becomes easier. That is, 1) First, the guide plate 5 is disposed above the output side plate 4, and 2) Next, the lower end of the coil spring 30 is accommodated in the output side recess 40, and the upper end is accommodated in the coil spring holding hole 50. 3) Finally, the coil spring 30 can be easily attached by accommodating the upper end of the coil spring 30 in the recess 22 on the input side. Note that the steps 1) and 3) may be reversed. That is, the arrangement order of the input side plate and the output side plate may be reversed. Further, when the guide plate 5 is arranged, the displacement of the coil spring 30 during the conveyance and use of the cell pressing assembly 1 can be further suppressed. In this manner, the coil spring 30 can be positioned more easily due to the synergistic effect of the input-side recess 22, the output-side recess 40, and the guide plate 5. Further, since the guide rod 43 has a head with a hexagonal hole, the screwing operation of the guide rod 43 is easy, and the cell pressing assembly 1 can be easily assembled.

<Second embodiment>
The difference between the cell pressing assembly of the present embodiment and the cell pressing assembly of the first embodiment is that the center portion and the load portion coincide. That is, all the parts other than the load part in the input side plate are peripheral parts. Therefore, only the differences will be described here.

  In FIG. 15, the bottom view of the input side plate of the cell press assembly of this embodiment is shown. In addition, about the site | part corresponding to FIG. 8, it shows with the same code | symbol. FIG. 16 is a cross-sectional view in the XVI-XVI direction of FIG. In addition, about the site | part corresponding to FIG. 10, it shows with the same code | symbol.

  As shown in FIGS. 15 and 16, the central portion R30 coincides with the load portion. That is, the central portion R30 has a short-axis columnar shape, and a pair is disposed on the left and right sides of the input side plate 2. A peripheral portion R40 is disposed in all portions of the input side plate 2 other than the central portion R30. A portion of the pressing surface 26 corresponding to the central portion R30 has a portion “back” spherical shape that is gently recessed upward. For this reason, the plate | board thickness of center part R30 is not constant. However, the average plate thickness of the central portion R30 is smaller than the average plate thickness of the peripheral portion R40.

  The cell pressing assembly of the present embodiment has the same effects as the cell pressing assembly of the first embodiment with respect to the parts having the same configuration. Further, according to the input side plate 2 of the cell pressing assembly of the present embodiment, the central portion R30 having a small average plate thickness is disposed only in the portion where the largest load is applied. Therefore, the input side plate 2 is easy to ensure desired rigidity.

<Third embodiment>
The difference between the cell pressing assembly of the present embodiment and the cell pressing assembly of the first embodiment is that all the input side recesses of the pressing surface have a perfect circular shape. Moreover, it is a point by which the recessed part between opening parts is not arrange | positioned. Therefore, only the differences will be described here.

  In FIG. 17, the perspective view of the input side plate of the cell press assembly of this embodiment is shown. In addition, about the site | part corresponding to FIG. 7, it shows with the same code | symbol. As shown in FIG. 17, all the input side recessed parts 22 of the press surface 26 are exhibiting perfect circle shape. That is, as shown in FIG. 11, the input-side recess 22 includes a perfect circle opening 220b and a true circle bottom 221b having a smaller diameter than the perfect circle opening 220b. Further, the inter-opening recess 223 as shown in FIG. 11 is not formed between the openings of the three adjacent input-side recesses 22.

  The cell pressing assembly of the present embodiment has the same effects as the cell pressing assembly of the first embodiment with respect to the parts having the same configuration. Moreover, according to the input side plate 2 of the cell pressing assembly of this embodiment, all the input side recessed parts 22 are exhibiting perfect circle shape. And the recessed part between opening parts is not arrange | positioned. For this reason, the input side plate 2 is easy to ensure desired rigidity.

<Fourth embodiment>
The difference between the cell pressing assembly of this embodiment and the cell pressing assembly of the first embodiment is that the plate thickness of the input side plate is constant. In addition, the input side recess is not tapered. Moreover, it is a point by which the recessed part between opening parts is not arrange | positioned. Therefore, only the differences will be described here.

  FIG. 18 shows a bottom view of the input side plate of the cell pressing assembly of this embodiment. In addition, about the site | part corresponding to FIG. 8, it shows with the same code | symbol. FIG. 19 shows a cross-sectional view in the XIX-XIX direction of FIG. In addition, about the site | part corresponding to FIG. 10, it shows with the same code | symbol.

  As shown in FIGS. 18 and 19, the plate thickness of the input side plate 2 is constant. Moreover, the opening part and bottom part of the input side recessed part 22 are exhibiting the same shape. That is, the taper shape which narrows toward the bottom from the opening is not set. Further, the inter-opening recess 223 as shown in FIG. 11 is not formed between the openings of the three adjacent input-side recesses 22.

  The cell pressing assembly of the present embodiment has the same effects as the cell pressing assembly of the first embodiment with respect to the parts having the same configuration. Moreover, according to the input side plate 2 of the cell pressing assembly of the present embodiment, the plate thickness is constant. And the recessed part between opening parts is not arrange | positioned. For this reason, the input side plate 2 is easy to ensure desired rigidity.

<Fifth embodiment>
The difference between the cell pressing assembly of this embodiment and the cell pressing assembly of the first embodiment is that the plate thickness of the input side plate is constant. In addition, the input side recess is not tapered. Moreover, all the input side recessed parts of a press surface are the points which are exhibiting perfect circle shape. Therefore, only the differences will be described here.

  In FIG. 20, the bottom view of the input side plate of the cell press assembly of this embodiment is shown. In addition, about the site | part corresponding to FIG. 8, it shows with the same code | symbol. As shown in FIG. 20, the plate thickness of the input side plate 2 is constant. Moreover, the opening part and bottom part of all the input side recessed parts 22 are exhibiting the perfect circle shape of the same diameter. That is, the taper shape which narrows toward the bottom from the opening is not set. Further, the substantially regular hexagonal input side recess 22 is not arranged.

  The cell pressing assembly of the present embodiment has the same effects as the cell pressing assembly of the first embodiment with respect to the parts having the same configuration. Moreover, according to the input side plate 2 of the cell pressing assembly of the present embodiment, the plate thickness is constant. And all the input side recessed parts 22 are exhibiting perfect circle shape. For this reason, the input side plate 2 is easy to ensure desired rigidity.

<Sixth embodiment>
The difference between the cell pressing assembly of the present embodiment and the cell pressing assembly of the first embodiment is that the input side recesses are arranged in a grid pattern on the pressing surface. In addition, the input side recess of the load region has a substantially square shape. Therefore, only the differences will be described here.

  In FIG. 21, the bottom view of the input side plate of the cell press assembly of this embodiment is shown. In addition, about the site | part corresponding to FIG. 8, it shows with the same code | symbol. As shown in FIG. 21, the input-side recess 22 is linearly arranged in the front-rear direction and the left-right direction. That is, the input side recesses 22 are arranged in a lattice pattern. For this reason, the arbitrary input-side recess 22 is surrounded by the four input-side recesses 22.

  The input-side recess 22 arranged in the load region r1 has a substantially square shape. That is, the input-side recess 22 in the load region r1 includes a square opening 230a and a square bottom 231a. The square opening 230a is included in the polygonal opening of the present invention. The area of the square opening 230a is larger than the area of the square bottom 231a.

  The square opening 230a includes four straight portions and four curved portions. These linear portions and curved portions are alternately connected to form a square opening 230a. The area of the square opening 230a is larger than the area of the perfect circular opening 220b. The perfect circle opening 220b corresponds to the inscribed circle of the square opening 230a. Similarly, the area of the square bottom 231a is larger than the area of the perfect circle bottom 221b. The perfect circle bottom 221b corresponds to the inscribed circle of the square bottom 231a.

  A large number of inter-opening recesses 224 (shown by hatching) are arranged in the load region r1. Each of the recesses 224 between the openings is disposed in the surrounding region r20 (indicated by a two-dot chain line). The surrounding region r20 is formed by connecting the centers of gravity of four adjacent openings, and has a square shape. Moreover, the recessed part 224 between opening parts is exhibiting the part "back" spherical shape.

  The cell pressing assembly of the present embodiment has the same effects as the cell pressing assembly of the first embodiment with respect to the parts having the same configuration. Further, according to the input side plate 2 of the cell pressing assembly of the present embodiment, the number of the input side recesses 22 is less than that of the input side plate 2 shown in FIG. For this reason, the thickness between the openings between the adjacent input side recesses 22 is increased. Therefore, the input side plate 2 is easy to ensure desired rigidity.

<Seventh embodiment>
The difference between the cell pressing assembly of the present embodiment and the cell pressing assembly of the first embodiment is that the input side recess is not arranged at the center of the load region. In addition, among the input side recesses, the six input side recesses surrounding the center of the load region have a deformed circular shape. In addition, a single hexagonal surrounding region is disposed at the center of the load region, and a triangular surrounding region is disposed around the hexagonal surrounding region. Therefore, only the differences will be described here.

  FIG. 22 shows an enlarged view near the load region. In addition, about the site | part corresponding to FIG. 11, it shows with the same code | symbol. As shown in FIG. 22, the six input side recessed parts 22 arrange | positioned at the load area | region r1 are exhibiting the deformed circle shape. That is, the input-side recess 22 in the load region r1 includes a deformed circular opening 220e and a deformed circular bottom 221e. The area of the deformed circular opening 220e is larger than the area of the deformed circular bottom 221e.

  A single hexagonal surrounding region r21 is disposed at the center of the load region r1. A triangular enclosure region r22 is arranged around the enclosure region r21. A large inter-opening recess 225 is formed in the central surrounding region r21. Of the surrounding surrounding region r22, a small inter-opening recess 226 is formed in the front two surrounding regions r22 and the two rear surrounding regions r22 around the recess 225 between the openings.

  FIG. 23 shows an enlarged view in a circle XXIII in FIG. As shown in FIG. 23, the center end 220f of the deformed circular opening 220e is closer to the center of the load region than when the opening is a perfect circle (shown by a dotted line in FIG. 23). So that it is arranged. In other words, the center end 220f is shifted backward. The deformed circular opening 220e and the deformed circular bottom 221e have similar shapes.

  Returning to FIG. 22, the remaining five input-side recesses 22 arranged in the load region r <b> 1 have the same shape as the input-side recess 22 of FIG. 23. That is, the remaining five input-side recesses 22 have a shape obtained by rotating the input-side recesses 22 in FIG. 23 by approximately 60 ° with respect to the center of the circle of the load region.

  The cell pressing assembly of the present embodiment has the same effects as the cell pressing assembly of the first embodiment with respect to the parts having the same configuration. Moreover, according to the input side plate of the cell pressing assembly of this embodiment, the input side recessed part 22 is not arrange | positioned in the center of the load area | region r1. For this reason, it is easy to ensure rigidity.

  Further, a large single inter-opening recess 225 is disposed in the surrounding region r21, and four small inter-opening recesses 226 are disposed in the surrounding region r22. For this reason, in the load area | region r1, the maximum stress generate | occur | produced in the site | part between opening parts can be made small.

  Moreover, the six input side recessed parts 22 of the load area | region r1 are exhibiting the deformed circle shape which tapers toward the center of the load area | region r1. Also in this respect, the maximum stress in the load region r1 can be reduced.

<Others>
The embodiments of the fuel cell cell pressing assembly of the present invention have been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  For example, the manufacturing method of the input side plate 2 is not particularly limited. You may produce by cutting. Moreover, you may produce by casting. Further, the concave surface shapes of the central portions R3, R30 and the inter-opening recesses 223, 224 are not particularly limited. “Back” spherical shape, “back” conical shape, “back” pyramid shape, etc. may be used. Further, the concave shape is preferably a shape that can further suppress the warpage of the input side plate 2 when a load is applied. Moreover, in the said embodiment, although the guide plate 5 (refer above-mentioned FIG. 6) was arrange | positioned, the guide plate 5 does not need to be arrange | positioned.

  Moreover, the setting method of a center part is not specifically limited. For example, as in the first embodiment, the central portion R3 may be arranged so as to include a plurality of load portions R1 (see FIG. 8 above). Or you may arrange | position central part R30 locally for every load part like 2nd embodiment (refer above-mentioned FIG. 15).

  For example, when the input side recessed part 22 does not exhibit a taper shape like 4th embodiment, the board thickness of the input side plate 2 may be constant (refer above-mentioned FIG. 19). Further, for example, as can be seen by comparing the first embodiment and the sixth embodiment, the arrangement of the input-side recess 22 on the pressing surface 26 is not particularly limited (see FIGS. 8 and 21).

  Moreover, you may provide the level | step difference shape which narrows toward the bottom part from an opening part instead of a taper shape at the input side recessed part 22. FIG. In the above embodiment, a load is applied to the input side plate 2 from the pair of adjusting rods 6a and 6b via the rod receiving members 28a and 28b (see FIG. 4). There is no particular limitation. For example, the load may be applied using a single adjusting rod or three or more adjusting rods. Moreover, the part which applies a load is not specifically limited. In other words, there are no particular limitations on the number, location, and shape of the load portion R1 and load region r1. Moreover, in the said embodiment, although the coil spring 30 was used as an elastic body of this invention, you may use sponge, rubber | gum, an elastic resin etc., for example.

  The maximum stress and the maximum warp amount of the input side plate of the cell pressing assembly of the first embodiment were analyzed by FEM (finite element method) analysis. Hereinafter, the results will be described with reference to FIGS.

<Sample dimensions>
The length in the left-right direction of the input side plate 2 was set to 354.9 mm. The length in the front-rear direction was 149 mm. The plate thickness T4 of the peripheral portion R4 is 19 mm. The minimum thickness T3 of the central portion R3 was 14 mm. The length in the left-right direction of the central portion R3 was 292 mm. The length in the front-rear direction was 124.5 mm. Further, the pair of load regions r <b> 1 has a perfect circular shape with a diameter of 70 mm, and are respectively arranged from the center of gravity of the pressing surface 26 around a 90.25 mm portion on the left and right.

  Of the numerous input side recesses 22, the perfect circle opening 220 b of the perfect input side recess 22 has a perfect circle shape with a diameter of 19.1 mm. The perfect circle bottom 221b has a perfect circle shape with a diameter of 18.5 mm. The depth of the input-side recess 22 (the distance from the perfect circle opening 220b to the perfect circle bottom 221b) is 8 mm. On the other hand, the hexagonal opening 220a of the input side recess 22 having a substantially regular hexagonal shape has a substantially regular hexagonal shape to which the perfect circular opening 220b circumscribes. Similarly, the hexagonal bottom portion 221a of the substantially regular hexagonal input-side recess 22 has a substantially regular hexagonal shape that circumscribes the perfect circle bottom portion 221b. The depth of the input side recess 22 (distance from the hexagonal opening 220a to the hexagonal bottom 221a) is 3 mm. Moreover, the depth of the recessed part 223 between openings is 0.8 mm. The input side plate 2 having such dimensions was taken as an example. As the material characteristics of the sample, the input side plate 2 had a Young's modulus of 70600 MPa and a Poisson's ratio of 0.33.

  Further, in the input side plate 2, the plate thickness is constant (19 mm), all the input side concave portions 22 are made into a perfect circle shape, the perfect circle opening 220b has a diameter of 19 mm, the perfect circle bottom 221b has a diameter of 18 mm, and the gap between the openings An example in which the concave portion 223 is not disposed is used as a reference example (not a conventional example).

<Analysis results>
Table 1 shows the maximum stress and the amount of warpage of the maximum displacement portion R2 when a load of 40 kN is applied to each of the pair of load portions R1 by 20 kN.

  As shown in Table 1, the maximum stress was reduced by about 15% in the example with respect to the reference example. Further, in the example, the warpage amount was about 22% larger than the reference example.

<Summary>
By making the plate thickness of the central portion R3 smaller than the plate thickness of the peripheral portion R4, the substantially hexagonal input side recesses 22 are arranged in the load region r1, and the inter-opening recesses 223 are dispersedly arranged in the load region r1. The maximum stress can be reduced. In addition, although the warpage amount is slightly increased, it has been found that it is well within the allowable range for fuel cells.

(A) is a schematic cross section of the input side plate before a load is applied. (B) is a schematic cross section of the input side plate when a load is applied. (A) is the schematic diagram which looked at a pair of adjacent perfect circle opening part from the press surface upper direction. (B) is the schematic diagram which looked at a pair of adjacent polygonal opening part from the press surface upper direction. It is the schematic diagram which looked at three adjacent opening parts from the load area | region upper part of the press surface. It is a side view of the polymer electrolyte fuel cell with which the cell press assembly of a first embodiment was assembled. It is a perspective combined view of the cell pressing assembly. It is a perspective exploded view of the cell pressing assembly. It is a perspective view of the input side plate of the cell pressing assembly. It is a bottom view of the input side plate. It is the IX-IX direction sectional drawing of FIG. It is XX direction sectional drawing of FIG. FIG. 9 is an enlarged view near a load region r1 in FIG. It is an enlarged view of the input side recessed part in the load area | region r1. FIG. 12 is an enlarged perspective view of the vicinity of a concave portion on the input side disposed in the center of the load region r1 in FIG. FIG. 10 is an enlarged view in a frame XIV in FIG. 9. It is a bottom view of the input side plate of the cell pressing assembly of the second embodiment. It is the XVI-XVI direction sectional drawing of FIG. It is a perspective view of the input side plate of the cell press assembly of a third embodiment. It is a bottom view of the input side plate of the cell press assembly of 4th embodiment. It is the XIX-XIX direction sectional drawing of FIG. It is a bottom view of the input side plate of the cell press assembly of a fifth embodiment. It is a bottom view of the input side plate of the cell press assembly of 6th embodiment. It is an enlarged view near the load area | region of the input side plate of the cell press assembly of 7th embodiment. It is an enlarged view in circle XXIII of FIG.

Explanation of symbols

1: Cell pressing assembly.
2: input side plate, 21: guide rod through hole, 22: input side recess (accommodating recess), 220a: hexagonal opening (polygonal opening), 220b: perfect circular opening, 220c: linear part, 220d: Curved portion, 220e: deformed circular opening, 220f: center end, 221a: hexagonal bottom, 221b: perfect circle bottom, 221e: deformed circular bottom, 222: wall, 223: recess between openings, 224: opening Recesses between parts, 225: Recesses between openings, 226: Recesses between openings, 230a: Square openings (polygonal openings), 231a: Square bottom, 26: Press surface, 28a: Rod receiving member, 28b: Rod receiver Element.
3: Spring group (elastic body group), 30: Coil spring.
4: output side plate, 40: output side recess, 41: bolt fixing recess, 42: guide rod fixing hole, 43: guide rod, 44: nut, 45: bolt, 46: upper surface.
5: Guide plate, 50: Coil spring holding hole, 51: Bolt through hole, 52: Nut fastening hole.
6a: Adjustment rod, 6b: Adjustment rod.
8: Cell laminate, 80: Cell.
9: Solid polymer fuel cell, 90a: End plate, 90b: End plate, 900a: Adjust rod through hole, 900b: Adjust rod through hole, 91a: Insulating plate, 91b: Insulating plate, 92a: Terminal plate, 92b: Terminal plate, 93a: restraint plate, 93b: restraint plate, 94a: tension plate, 94b: tension plate.
100: perfect circular opening, 101: part between openings, 102: pressing surface, 103: polygon opening, 104: part between openings, 105: pressing surface, 106: opening, 107: recess between openings, 108: load region, 109: input side plate, 110: load portion, 111: maximum displacement portion, 112: pressing surface, 113: center portion, 114: peripheral portion, 115: rod.
A1: Displacement amount, B0: Boundary, B1: Displacement amount, B2: Boundary, G1: Center of gravity, L: Screw amount, L1: Straight line, L2: Straight line part, L3: Straight line, L4: Axis, P1-P3: Site R1: load part, R2: maximum displacement part, R3: center part, R30: center part, R4: peripheral part, R40: peripheral part, T3: minimum plate thickness, T4: plate thickness.
r0: Surrounding area, r1: Load area, r2: Surrounding area, r20: Surrounding area, r21: Surrounding area, r22: Surrounding area, t3: Thickness between openings, t4: Thickness between openings.

Claims (14)

An elastic group consisting of a plurality of elastic bodies;
An input side plate that is arranged on one end side of the elastic body group in the expansion / contraction direction and receives a load from the outside;
An output-side plate that is disposed on the other end side of the elastic body group in the expansion and contraction direction, outputs the load transmitted through the elastic body group, and presses the cell stack including a plurality of stacked cells;
A cell pressing assembly for a fuel cell comprising:
The input side plate includes one end of a plurality of elastic bodies and a pressing surface having a plurality of receiving recesses in which the area of the opening is larger than the area of the bottom, a load portion to which the load is applied, and the load A maximum displacement portion where the amount of displacement with respect to the load portion when the is applied is maximized,
The cell pressing assembly for a fuel cell, wherein an average plate thickness of the load portion is smaller than an average plate thickness of the maximum displacement portion. The input side plate includes a central portion including the load portion, and a peripheral portion including the maximum displacement portion,
The cell pressing assembly for a fuel cell according to claim 1, wherein an average plate thickness of the central portion is smaller than an average plate thickness of the peripheral portion.   The boundary between the central portion and the peripheral portion is set in a range in which the displacement amount is 5% or more and 100% or less, where the displacement amount of the maximum displacement portion with respect to the load portion is 100%. The cell pressing assembly for a fuel cell as described.   The cell pressing assembly for a fuel cell according to any one of claims 1 to 3, wherein the elastic body is a coil spring. An elastic group consisting of a plurality of elastic bodies;
An input side plate that is arranged on one end side of the elastic body group in the expansion / contraction direction and receives a load from the outside;
An output-side plate that is disposed on the other end side of the elastic body group in the expansion and contraction direction, outputs the load transmitted through the elastic body group, and presses the cell stack including a plurality of stacked cells;
A cell pressing assembly for a fuel cell comprising:
The input side plate has a pressing surface having a plurality of accommodating recesses in which one end portions of the plurality of elastic bodies are accommodated,
The pressing surface has a load region to which the load is applied from the back side,
Among the accommodating recesses arranged in the load region, at least a part of the openings of the accommodating recesses are substantially polygonal polygonal openings,
Of the accommodating recesses disposed in the region other than the load region, at least a part of the opening of the accommodating recess is a substantially circular opening of a perfect circle,
The area of the polygonal opening is larger than the area of the perfect circular opening,
A cell pressing assembly for a fuel cell, wherein linear portions of adjacent polygonal openings are arranged so as to be substantially parallel to each other.   The cell pressing assembly for a fuel cell according to claim 5, wherein the polygonal opening has a substantially regular hexagonal shape in which adjacent straight portions are connected via a curved portion.   The cell pressing assembly for a fuel cell according to claim 5 or 6, wherein an area of the opening of the housing recess is larger than an area of a bottom of the housing recess.   The cell pressing assembly for a fuel cell according to any one of claims 5 to 7, wherein the elastic body is a coil spring. An elastic group consisting of a plurality of elastic bodies;
An input side plate that is arranged on one end side of the elastic body group in the direction of expansion and contraction and receives a load from the outside;
An output side plate that is disposed on the other end side in the expansion and contraction direction of the elastic body group, and presses the cell stack composed of a plurality of stacked cells by the load transmitted through the elastic body group;
A cell pressing assembly for a fuel cell comprising:
The input side plate has a pressing surface having a plurality of accommodating recesses in which one end portions of the plurality of elastic bodies are accommodated,
The pressing surface has a load region to which the load is applied from the back side,
Among the surrounding areas formed by connecting the centers of gravity of the openings of three or more adjacent receiving recesses including the receiving recesses arranged in the load area, at least some of the recesses between the openings are arranged. A cell pressing assembly for a fuel cell.   The cell pressing assembly for a fuel cell according to claim 9, wherein the surrounding region has a triangular shape. One of the surrounding regions arranged in the center of the load region has a hexagonal shape, and the other has a triangular shape,
The cell pressing assembly for a fuel cell according to claim 9, wherein the recess between the openings is arranged in at least the hexagonal surrounding region of the hexagonal and triangular surrounding regions.   Among the openings of the housing recess, the opening forming the hexagonal surrounding region is closest to the center of the load region of the opening compared to the case where the opening is a perfect circle. The cell pressing assembly for a fuel cell according to claim 11, wherein the center end further has a deformed circular shape arranged so as to be close to the center of the load region.   The cell pressing assembly for a fuel cell according to any one of claims 9 to 12, wherein an area of the opening of the housing recess is larger than an area of a bottom of the housing recess.   The cell pressing assembly for a fuel cell according to any one of claims 9 to 13, wherein the elastic body is a coil spring.

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