JP4670345B2 - Manufacturing method of fuel cell - Google Patents

Description

  The present invention relates to a method of manufacturing a fuel cell having a structure in which a plurality of fuel cell constituent members are stacked and fastened in a state where a shaft is passed through a fuel cell constituent member such as a single cell and restrained in a predetermined direction.

  The fuel cell (stack) has a structure in which fuel cell components such as single cells are stacked. The plurality of stacked fuel cell constituent members are usually held in a state of being fastened in the stacking direction. Further, when the number of fuel cell constituent members increases, it becomes difficult to hold the plurality of fuel cell antibiotics only by the fastening force in the stacking direction. The constituent members are constrained with respect to a predetermined direction. Thereby, even if the number of fuel cell constituent members increases, a plurality of stacked fuel cell constituent members can be securely fastened and held.

  Conventionally, a method of manufacturing a fuel cell having such a structure has been proposed (see, for example, Patent Document 1).

  In this conventional manufacturing method, a through-hole is formed in a single cell serving as a fuel cell constituent member, and a plurality of the single cells are stacked in the through-hole through an intermediate adapter (shaft). I try to restrain it. The diameter of the through hole and the diameter of the intermediate adapter are determined so that a predetermined gap is formed between the intermediate adapter and the through hole, and the outer peripheral surface of the intermediate adapter should be pressed against the through hole. A protrusion is formed.

As described above, since the gap is formed between the intermediate adapter and the through hole, it is easy to stack the single cells through the adapter in the through hole, and the protrusion of the intermediate adapter is formed in the through hole in each single cell. By pressing against the peripheral surface, each single cell can be firmly fixed.
Japanese Patent Laid-Open No. 2001-57226

  However, in the conventional fuel cell manufacturing method as described above, although there is a gap between the intermediate adapter and the through hole, the protrusion of the intermediate adapter comes into pressure contact with the through hole. When the intermediate adapter (shaft) is passed through the through hole, the projection becomes an obstacle, and the work is not easily performed. Moreover, there is a possibility that the fuel cell constituent member cannot be held with a sufficient restraining force only by the protrusions.

  The present invention has been made in order to solve such a conventional problem, and can facilitate the assembly work of the fuel cell constituent members and can more reliably restrain the fuel cell constituent members. A method for manufacturing a fuel cell is provided.

  According to the fuel cell manufacturing method of the present invention, a plurality of fuel cell constituent members are stacked through a shaft in the through hole of the fuel cell constituent member having a through hole formed at a predetermined position, and the plurality of fuel cell constituent members are A method of manufacturing a fuel cell by fastening in a stacking direction in a state of being constrained in a predetermined direction by a shaft, wherein a shaft whose width in the predetermined direction to be constrained is variable by a predetermined operation is used. A first step of laminating the fuel cell constituting member through the shaft in the through hole in a state where a first gap is formed in the predetermined direction between the through hole and the shaft; and the shaft and the through hole And a second step of performing a predetermined operation on the shaft so that a second gap smaller than the first gap is formed in the predetermined direction to be restrained between Configuration and become.

  With such a configuration, the fuel cell constituent member can be stacked through the through hole in the state where the first gap is formed in a predetermined direction between the shaft and the through hole to be restrained. Next, by performing a predetermined operation on the shaft, a second gap smaller than the first gap is formed in a predetermined direction to be restrained between the shaft and the through hole. In this state, the fuel cell constituent member is restrained in the predetermined direction to be restrained.

  The second gap can be set to a value small enough to restrain the fuel cell constituent member by the shaft, and may be zero, for example. The first gap can be set larger than the second gap to such an extent that the ease of working the shaft through the through hole is not impaired.

  In the fuel cell manufacturing method according to the present invention, the shaft includes a core shaft and an elastic layer covering a surface of the core shaft, and the second step includes the elastic layer as the fuel cell component. The gap in the predetermined direction to be constrained between the elastic layer and the through hole is changed from the first gap to the second gap by performing an operation of compressing in the stacking direction. .

  With this configuration, the elastic layer of the shaft is compressed in the stacking direction of the fuel cells in a state where the fuel cell constituent members are stacked through the shaft so that the first gap is generated in a predetermined direction to be restrained. When the operation is performed, the diameter of the elastic layer in the direction perpendicular to the stacking direction increases. As a result, the gap in the predetermined direction to be constrained between the through hole and the elastic layer is changed from the first gap to the second gap.

  Furthermore, the fuel cell manufacturing method according to the present invention may be configured such that the elastic layer of the shaft is formed of an insulator.

  With such a configuration, even if the core shaft is made of metal, insulation between the metal fuel cell constituent member and the core shaft can be secured. For this reason, a metal fuel cell structural member can be restrained by a highly rigid shaft as a whole using a highly rigid metal core shaft.

  Further, in the fuel cell manufacturing method according to the present invention, the shaft has a cross-sectional shape perpendicular to the axial center in which the width in a predetermined direction perpendicular to the axial center is larger than the width in the other direction. A step of setting the shaft in a state in which the direction in which the width of the shaft increases and the predetermined direction to be constrained do not coincide with each other, and in a predetermined direction to be constrained between the shaft and the through hole; 1 is formed, and the second step rotates the shaft so that the direction in which the width increases and the predetermined direction to be constrained coincide with each other. The second gap may be formed in a predetermined direction to be constrained between the holes.

  With such a configuration, the gap in the predetermined direction between the shaft and the through hole is deviated from the relatively large first gap by a relatively simple operation such as a rotation operation around the shaft axis. It becomes possible to change to a smaller second gap.

  According to the fuel cell manufacturing method of the present invention, fuel is passed through the shaft through the through hole in a state where a relatively large first gap is formed in a predetermined direction between the shaft and the through hole to be restrained. Since the battery constituent members can be stacked, the stacking operation of the fuel cell constituent members can be facilitated. Further, by operating the shaft in this state, the second gap is small enough to sufficiently restrain the fuel cell constituent member from the first gap in a predetermined direction between the shaft and the through hole to be restrained. Thus, the fuel cell constituent member can be reliably restrained in the predetermined direction to be restrained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A fuel cell (stack) to be manufactured by the manufacturing method according to the embodiment of the present invention is configured as shown in FIG. In each of the plurality of single cells constituting the fuel cell (stack) (a structure in which the MEA (membrane / electrode assembly) is sandwiched between a pair of separators), the proportion of the physical separator is structurally large. In the description, a separator is used to mean a single cell.

  In FIG. 1, this fuel cell (stack) has a structure in which a plurality of plate-like separators 10 serving as fuel cell constituent members are stacked between a pair of end plates 21 and 22. The plurality of stacked separators 10 are fastened and fixed between the end plates 21 and 22 by the pressing force of the spring box 23 adjusted by the load adjusting screw 24. Further, each of the stacked separators 10 is constrained in a direction (vertical direction in the drawing) perpendicular to the stacking direction by external constraining shafts 30a and 30b penetrating the peripheral portions thereof.

  Although not shown in FIG. 1, tension members that apply pressure to the external restraint shafts 30a and 30b are provided outside the end plates 21 and 22, respectively.

  A manufacturing method according to the first embodiment of the present invention for manufacturing a fuel cell having such a structure will be described.

  As shown in FIG. 2A, each separator 10 is formed with a circular through hole 11 at a portion to be restrained. Further, the external constraining shaft 30 (in the case of generically referring to the external constraining shafts 30a and 30b shown in FIG. 1, the reference number 30 is used), and the core shaft 31 made of metal (for example, stainless steel) and the like An elastic layer 32 made of an elastic material such as silicon rubber is provided to cover it. That is, the external constraining shaft 30 has a structure in which the core shaft 31 is fitted into the cylindrical elastic layer 32. The outer diameter of the external restraint shaft 30 is set to be smaller than the inner diameter of the through hole 11 formed in the separator 10.

  A state in which the external restraint shaft 30 as described above is used and the external restraint shaft 30 is loosely fitted in the through hole 11, specifically, as shown in FIG. 2A, between the external restraint shaft 30 and the through hole 11. In a state where the first gap Δ1 is formed in the predetermined direction A (see the block arrow) to be restrained, the separator 10 is stacked in the through hole 11 through the external restraint shaft 30 (first step). The plurality of separators 10 stacked in this manner are fastened and fixed (fastened) between the end plates 21 and 22 by the pressing force of the spring box 23 adjusted by the adjusting screw 24. At that time, the elastic layer 32 of the external constraining shaft 30 disposed between the end plates 21 and 22 is compressed in the stacking direction of the separator 10 by the end plates 21 and 22 (second step).

  Due to the compression of the elastic layer 32, the thickness of the elastic layer 32 is increased, the gap between the elastic layer 32 and the through hole 11 of each separator 10 is reduced, and the gap in the direction A in which the separator 10 is to be restrained is described above. The first gap Δ1 is changed to a second gap Δ2 that is smaller than the first gap Δ1. The hardness of the elastic layer is set so that the second gap Δ2 is, for example, about 0.1 mm. Thereby, the movement of the direction A of each separator 10 stacked between the end plates 21 and 22 is restrained by the external restraint shaft 30.

  According to the first embodiment of the present invention as described above, when the separators 10 are stacked, the first between the through hole 11 and the external restraint shaft 30 at least in the direction A to be restrained. Since a relatively large gap is formed as the gap Δ1, the operation of laminating the separators 10 through the external constraining shaft 30 in the through hole 11 can be easily performed. Further, when each separator 10 is fastened between the end plates 21 and 22, the elastic layer 32 of the external constraining shaft 30 is compressed to increase its thickness, and between the through hole 11 and the external constraining shaft 30. Since the gap becomes the second gap Δ2 that is much smaller than the first gap Δ1 in the direction A to be restrained, each separator 10 is surely restrained in the direction A.

  Further, since the elastic layer 32 is formed of an insulator such as silicon rubber, it is possible to ensure insulation from the metal separator 10 even if the core shaft 31 is made of a metal such as a stainless steel material. That is, it is possible to realize the external constraining shaft 30 in which the insulation with the separator 10 is secured by using the highly rigid metal core shaft 31.

  Note that when the stacked separators 10 are fastened, particularly, the separator 10 located near the spring box 23 slightly moves in the axial direction of the external restraint shaft 30. The second gap Δ2 described above is set to a small value (for example, about 0.1 mm) so as not to hinder this movement. However, for example, when the movement amount is small and the frictional force with respect to the fastening force is small, the second gap Δ2 may be zero.

  A manufacturing method according to the second embodiment of the present invention for manufacturing the fuel cell having the above-described structure (see FIG. 1) will be described.

  In the second embodiment, as shown in FIG. 3 (a), each separator 10 is formed with elliptical through holes 11a and 11b at portions to be restrained. The external restraint shaft 30 is formed of, for example, hard resin or the like, and has a cross section in the direction perpendicular to the axis thereof having an elliptical shape. As shown in FIG. 3B, the relative relationship between the through holes 11 each having an elliptical shape (the reference number 11 is used when the through holes 11a and 11b are collectively referred to) and the cross section of the external restraint shaft 30 is shown. It has become. That is, the through hole 11 has an elliptical shape having a major axis side diameter R1a and a minor axis side diameter R1b, and the cross section of the external restraint shaft 30 has an elliptical shape having a major axis side diameter R2a and a minor axis side diameter R2b. The major axis side diameter R2a of the cross section of the constraining shaft 30 is set smaller than the minor axis side diameter R1b of the through hole 11 (R2a <R1b). Further, the through hole 11 is formed so that the minor axis direction thereof coincides with the direction A in which the separator 10 should be restrained (see FIG. 3A).

  Using the separator 10 as described above and the external constraining shaft 30 having the cross-sectional shape as described above, a fuel cell is manufactured as follows.

  The separator 10 is laminated by passing the through hole 11 through the external constraining shaft 30 so that the short axis direction of the external constraining shaft 30 and the short axis direction of the through hole 11 are aligned (first step). In this case, the short axis side of the external constraining shaft 30 in the direction A (see the block arrow) between the external constraining shaft 30 and the through hole 11a as in the through hole 11a side shown in FIG. A first gap Δ1 based on the difference between the diameter R2b and the short-axis diameter R1b of the through hole 11a is formed. Thereafter, the external constraining shaft 30 disposed between the end plates 21 and 22 is rotated by 90 ° (second step). Then, as in the through hole 11b side shown in FIG. 3 (a), the long axis side diameter R2b of the external restricting shaft 30 and the through hole 11b in the direction A to be constrained between the external restricting shaft 30 and the through hole 11b. The second gap Δ2 based on the difference from the short axis side diameter R1b is formed. As shown in FIG. 3B, the second gap Δ2 is smaller than the second gap Δ1.

  The second gap Δ2 (for example, such that the first gap Δ1 is formed so as not to hinder the operation of passing the external restriction shaft 30 through the through hole 11 and the separator 10 can be sufficiently restricted) The elliptical shape of each of the through hole 11 and the external constraining shaft 30 is set so that a thickness of about 0.1 mm is formed.

  As described above, after the external constraining shaft 30 is rotated by 90 ° and the separators 30 stacked by the external constraining shaft 30 are constrained in the direction A, the stacked separators 10 are located between the end plates 21 and 22. It is fastened and fixed (fastened).

  According to the second embodiment of the present invention, when the separators 10 are stacked, the first gap Δ1 is formed between the through hole 11 and the external restraint shaft 30 in the direction A to be restrained. Since a relatively large gap is formed, the operation of laminating the separators 10 through the external constraining shaft 30 in the through hole 11 can be easily performed. Further, by rotating the external restraint shaft 30 by 90 °, the gap between the through hole 11 and the external restraint shaft 30 is a second gap Δ2 that is much smaller than the first gap in the direction A to be restrained. Therefore, each separator 10 is reliably restrained in the direction A.

  A manufacturing method according to the third embodiment of the present invention for manufacturing the fuel cell having the above-described structure (see FIG. 1) will be described.

  In the third embodiment, as shown in FIGS. 4 and 5, each separator 10 is formed with an elliptical through-hole 11 at a portion to be restrained. Further, the external constraining shaft 30 is formed of, for example, hard resin, and is sandwiched between the rotation center shaft portions 33 and 34 and the rotation center shaft portions 33 and 34 having the same axis Lc1 as shown in FIG. It has the structure which has the curved axis part 35 (column shape) formed in this. The shaft center Lc2 of the curved shaft portion 35 is eccentric from the shaft center Lc1 of the rotation center shaft portions 33 and 34, and the shaft center Lc1 is similar to the relationship between the elliptical short-axis side diameter and long-axis side diameter described above. The width (length) in a predetermined direction perpendicular to the width is larger than the width (length) in the other direction. Further, the through hole 11 formed in each separator 10 has a region Ec (in the movement locus) of the outer peripheral surface of the curved shaft portion 35 when the external constraining shaft 30 is rotated about the rotation center shaft portions 33 and 34 (see FIG. 4 and the two-dot chain line in FIG. 5). Further, the through hole 11 is formed so that the minor axis direction thereof coincides with the direction A in which the separator 10 should be restrained.

  Using the separator 10 as described above and the external restraint shaft 30 having the shape as described above, a fuel cell is manufactured as follows.

  As shown in FIG. 4, the external restraint shaft 30 in which one rotation center shaft portion 33 is fitted in the rotation hole 21 a of the end plate 21 has an outer peripheral surface of the curved shaft portion 35 in the long axis direction of the through hole 11. Set to face. In this state, the separator 10 is laminated by passing the through hole 11 through the external restraint shaft 30 (first step). In this case, since the direction in which the curved shaft portion 35 of the external restraint shaft 30 is formed does not coincide with the direction A (see the block arrow) restraining the separator 10, at least between the external restraint shaft 30 and the through hole 11. A relatively large first gap Δ1 is formed in the direction A to be restrained. Further, in this case, since the through hole 11 is wider than the region Ec of the movement locus on the outer peripheral surface of the curved shaft portion 35 when the external constraining shaft 30 is rotated, it is formed around the external constraining shaft 30. The gap between the through-hole 11 to be made becomes even larger.

  After the plurality of separators 10 are stacked in this manner, as shown in FIG. 5, the other rotation center shaft portion 34 is fitted into the rotation hole 22 a of the end plate 22, and the external restraint shaft 30 is connected to the curved shaft portion. The outer peripheral surface of 25 is turned 90 ° so as to face the short axis direction of the through hole 11 (second step). Then, the direction in which the curved shaft portion 35 of the external restraint shaft 30 is formed coincides with the direction A in which the separator 10 is restrained, and the first direction in the restraint direction A between the external restraint shaft 30 and the through hole 11 is the first. A second gap Δ2 (for example, 0.1 mm) smaller than the gap Δ1 is formed.

  Thereafter, the stacked separators 10 are fastened and fixed (fastened) between the end plates 21 and 22.

  According to the third embodiment of the present invention as described above, when the separators 10 are stacked, the first between the through hole 11 and the external restraint shaft 30 at least in the direction A to be restrained. Since a relatively large gap is formed as the gap Δ1, the operation of laminating the separators 10 through the external constraining shaft 30 in the through hole 11 can be easily performed. Further, by rotating the external restraint shaft 30 by 90 °, the second gap Δ2 in which the gap between the through hole 11 and the external restraint shaft 30 is much smaller than the first gap Δ1 in the direction A to be restrained. Therefore, each separator 10 is reliably restrained in the direction A.

  In each of the above-described embodiments, the separator 10 (single cell) has been described as a fuel cell constituent member. However, as the fuel cell constituent member, an MEA that constitutes a single cell, a single separator, and a plurality of single cells are stacked. It may be a multi-cell module that is bonded and fixed. Furthermore, as shown in FIG. 6, in the fuel cell (stack) having a structure in which an end cell 15 (reset plate) not involved in power generation is sandwiched between a plurality of separators 10 (multi-cell module), the end cell 15 is also a fuel cell component. In this case, the through-hole 11 as described above is formed in each end cell 15, and the external restraint shafts 30 a and 30 b as described above are passed through the through-hole 11, so that the end portions are formed by the external restraint shafts 30 a and 30 b. The cell 15 is restrained.

  As described above, according to the method of manufacturing a fuel cell according to the present invention, the assembly operation of the fuel cell constituent member can be facilitated, and the fuel cell constituent member can be more reliably restrained. A fuel cell manufacturing method having a structure in which a plurality of fuel cell constituent members are stacked and fastened in a state in which a shaft is passed through a fuel cell constituent member such as a single cell and restrained in a predetermined direction. Useful as.

It is a figure which shows the structural example of a fuel cell (stack). It is a figure which shows the manufacturing method of the fuel cell which concerns on the 1st Embodiment of this invention. It is a figure which shows the manufacturing method of the fuel cell which concerns on the 2nd Embodiment of this invention. It is a figure which shows the 1st process in the manufacturing method of the fuel cell which concerns on the 3rd Embodiment of this invention. It is a figure which shows the 2nd process in the manufacturing method of the fuel cell which concerns on the 3rd Embodiment of this invention. It is a figure which shows the other structural example of a fuel cell (stack).

Explanation of symbols

10 Separator (single cell)
11 (11a, 11b) Through hole 15 End cell 21, 22 End plate 21a, 22a Rotating hole 23 Spring box 24 Load adjusting screw 30 (30a, 30b) External restraint shaft 31 Core shaft 32 Elastic layer 33, 34 Center of rotation Shaft 35 Curved Shaft

Claims (4)

A plurality of fuel cell constituent members are stacked through a shaft in the through hole of the fuel cell constituent member having a through hole formed at a predetermined position, and the fuel cell constituent members are stacked in a state of being constrained in a predetermined direction by the shaft. A method of manufacturing a fuel cell by fastening in a direction,
Using a shaft whose width in a predetermined direction to be restrained is variable by a predetermined operation,
A first step of laminating the fuel cell constituent member through the shaft in the through hole in a state where a first gap is formed in the predetermined direction to be constrained between the shaft and the through hole;
And a second step of performing a predetermined operation on the shaft such that a second gap smaller than the first gap is formed in the predetermined direction to be constrained between the shaft and the through hole. Method. The shaft has a core shaft and an elastic layer covering the surface of the core shaft,
In the second step, an operation of compressing the elastic layer in the stacking direction of the fuel cell constituent members is performed, and a gap in the predetermined direction to be constrained between the elastic layer and the through hole is formed in the first step. 2. The method of manufacturing a fuel cell according to claim 1, wherein the gap is changed from the gap to the second gap.   The fuel cell manufacturing method according to claim 2, wherein the elastic layer of the shaft is formed of an insulator. The shaft has a cross-sectional shape perpendicular to the axis, the width in a predetermined direction perpendicular to the axis is greater than the width in the other direction;
The first step sets the shaft in a state where the direction in which the width of the shaft increases and the predetermined direction to be constrained do not coincide with each other, and the predetermined to be constrained between the shaft and the through hole A first gap is formed in the direction,
In the second step, the predetermined direction to be constrained between the shaft and the through hole is obtained by rotating the shaft so that the direction in which the width increases and the predetermined direction to be constrained coincide with each other. 2. The method of manufacturing a fuel cell according to claim 1, wherein the second gap is formed in a direction.

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