JP7276256B2 - METHOD FOR MANUFACTURING FUEL CELL SEPARATOR - Google Patents

Description

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

Patent Literature 1 discloses a method of manufacturing a fuel cell separator made of a mixture of carbon powder and thermoplastic resin. In this production method, first, the mixture is extruded to form a sheet-like molding. After that, the pattern is transferred to the sheet-like molding by a rolling roller having grooves corresponding to the pattern of the separator. As a result, a separator is manufactured in which gas flow paths corresponding to the shape of the grooves are formed.

Japanese Patent Application Laid-Open No. 2002-198062

By the way, the fuel cell separator is formed on one side in the thickness direction of the separator and has a plurality of types of gas flow paths through which reactant gases flow. The plurality of types of gas flow paths include gas flow paths extending along a predetermined direction, gas flow paths extending obliquely with respect to the predetermined direction, and the like.

In order to form such a plurality of types of gas flow paths on one side in the thickness direction of the separator, when a separator is manufactured using a rolling roller having a pattern of these gas flow paths, the dimensional accuracy of each gas flow path must be improved. It becomes difficult to secure them individually. Therefore, it is desired to improve the dimensional accuracy of the separator.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a fuel cell separator capable of improving dimensional accuracy.

A method of manufacturing a fuel cell separator for achieving the above object comprises a pair of rolls that rotate by fitting a mixture of a conductive carbon material and a resin material on a pair of parallel rotating shafts, respectively. By passing between the first gas flow path through which the reaction gas flows and the direction in which the first gas flow path extends, the first gas flow path through which the reaction gas flows and the direction in which the first gas flow path extends are formed on at least one side surface of the formed body. and second gas flow paths extending in different directions, wherein at least one roll of the pair of rolls is a first divided body, and the first divided body is and a second divided body divided in the axial direction of the rotating shaft, wherein the position of the first divided body and the position of the second divided body with respect to the rotating shaft are individually adjustable. The first protrusion projecting from the outer peripheral surface of the split body forms the first gas flow path, and the second protrusion protruding from the outer peripheral surface of the second split body forms the second gas flow path.

For example, when a roll in which the first divided body and the second divided body are integrally provided is used, it becomes difficult to change the relative positions of the first divided body and the second divided body. Therefore, in roll forming in which a mixture is made to flow between a pair of rolls, it may be difficult to ensure the dimensional accuracy of each gas flow path.

In this regard, according to the above method, the dimensional accuracy of each gas flow path can be ensured by individually adjusting the position of each divided body with respect to the rotating shaft. Therefore, the dimensional accuracy of the separator can be improved.

In the method for manufacturing a fuel cell separator, it is preferable that the first projecting portion and the second projecting portion are adjacent to each other in the axial direction.
According to this method, the first gas flow path formed by the first protrusion and the second gas flow path formed by the second protrusion are communicated. Here, by individually adjusting the position of each divided body with respect to the rotating shaft, the dimensional accuracy of each gas flow path can be ensured, so that each gas flow path can be smoothly communicated with each other.

In the above method of manufacturing a fuel cell separator, it is preferable that the first protrusion forms the entire first gas flow path, and the second protrusion forms the entire second gas flow path.

For example, when the middle portion of the first gas flow path is formed by the boundary portion of two divisions adjacent to each other, the dimensional accuracy of the first gas flow path depends on the positional accuracy of these two divisions. .

In this respect, according to the above method, each gas flow path does not have a portion formed by the boundary portion of two division bodies adjacent to each other. Accordingly, by individually positioning each divided body, the dimensional accuracy of each gas flow path can be individually ensured. Therefore, it becomes easy to improve the dimensional accuracy of the separator.

According to the present invention, the dimensional accuracy of the fuel cell separator can be improved.

FIG. 2 is a plan view showing a separator manufactured by an embodiment of a fuel cell separator manufacturing method; The front view which shows a roll forming machine. The perspective view which shows a 1st roll and a 2nd roll. Sectional drawing which shows an extruder. FIG. 2 is a cross-sectional view showing a roll forming machine in a state of roll forming a mixture;

An embodiment of a method for manufacturing a fuel cell separator will be described below with reference to FIGS. 1 to 5. FIG.
In each drawing, part of the configuration may be exaggerated or simplified for convenience of explanation. Also, the dimensional ratio of each part may differ from the actual one.

<Separator 10>
As shown in FIG. 1, the separator 10 has a rectangular plate shape having long sides and short sides in plan view. The separator 10 is composed of a mixture 100 in which a carbon material 101 and a resin material 102, which will be described later, are mixed.

Hereinafter, the direction in which the long sides of the separator 10 extend is referred to as the length direction L, and the direction in which the short sides of the separator 10 extend is referred to as the width direction W. Moreover, let the right side and the left side of FIG. 1 be the one side of the length direction L, and the other side of the length direction L, respectively. Let the upper side and lower side of FIG. 1 be the one side of the width direction W, and the other side of the width direction W, respectively. In addition, the length direction L and the width direction W are orthogonal.

As shown in FIG. 1, a fuel gas supply manifold 11, a cooling water supply manifold 13, and an oxidant gas discharge manifold 16 are arranged from one side in the width direction W at one end in the length direction L of the separator 10. They are provided in order toward the other side.

An oxidizing gas supply manifold 15, a cooling water discharge manifold 14, and a fuel gas discharge manifold 12 are provided in order from one side to the other side in the width direction W at the other end of the separator 10 in the length direction L. It is

A fuel gas such as hydrogen supplied to the fuel cell is supplied to a fuel gas supply manifold 11 and discharged to the outside through a fuel gas discharge manifold 12 . Oxidant gas such as air supplied to the fuel cell is supplied to an oxidant gas supply manifold 15 and discharged to the outside through an oxidant gas discharge manifold 16 . Also, the cooling water supplied to the fuel cell is supplied to the cooling water supply manifold 13 and discharged to the outside through the cooling water discharge manifold 14 .

The separator 10 is formed with a groove-like gas passage portion 20 through which the fuel gas, the oxidant gas, and the cooling water flow. In this embodiment, as an example of a fuel cell separator, a separator 10 having a gas channel portion 20 through which an oxidizing gas flows will be described.

The gas channel portion 20 includes a first gas channel 21 formed in the central portion of the separator 10, second gas channels 22 formed continuously at both ends of the first gas channel 21 in the length direction L, 23.

The first gas flow path 21 is composed of a plurality of grooves extending along the length direction L. As shown in FIG. The second gas flow paths 22 and 23 are composed of a plurality of grooves extending in directions inclined with respect to both the length direction L and the width direction W. As shown in FIG.

The second gas flow path 22 communicates the end of the first gas flow path 21 on one side in the length direction L with the fuel gas supply manifold 11 . The second gas flow path 23 communicates the other end of the first gas flow path 21 in the length direction L with the fuel gas discharge manifold 12 .

Extending along the length direction L in a portion of the separator 10 between the first gas flow path 21 and the oxidizing gas discharge manifold 16 and a portion between the first gas flow path 21 and the oxidizing gas supply manifold 15 A plurality of dimples 24 are provided. The plurality of dimples 24 are spaced apart from each other in the width direction W. As shown in FIG. Each dimple 24 is recessed in the direction orthogonal to the surface of the separator 10, ie, the direction orthogonal to the paper surface of FIG.

Next, an apparatus for manufacturing the separator 10 will be described.
<Roll forming machine 30>
First, the roll forming machine 30 will be described.

As shown in FIG. 2, the roll forming machine 30 includes a base 31 and a pair of side walls 32 and 33 projecting from the base 31 and spaced apart from each other. A first bearing 34 and a second bearing 35 are provided on each of the side walls 32 and 33 at intervals in the projecting direction of the side walls 32 and 33 . The first bearing 34 is provided at a position farther from the base 31 than the second bearing 35 in the projecting direction.

The roll forming machine 30 has a first rotating shaft 36 and a second rotating shaft 37 arranged in parallel. The first rotating shaft 36 is rotatably supported by the first bearings 34 of the side walls 32 and 33 . The second rotating shaft 37 is rotatably supported by the second bearings 35 of the side walls 32 and 33 .

A first roll 40 is fitted over a portion of the first rotating shaft 36 located between portions supported by the respective first bearings 34 . A second roll 50 is fitted over a portion of the second rotating shaft 37 positioned between portions supported by the respective second bearings 35 . The outer peripheral surface of the first roll 40 and the outer peripheral surface of the second roll 50 face each other.

Gears 36a and 37a that mesh with each other are provided at one end of the first rotating shaft 36 and one end of the second rotating shaft 37, respectively. A sprocket 37 b is provided at one end of the second rotating shaft 37 . The sprocket 37b is rotationally driven by an electric motor (not shown) through an endless chain (not shown) wound around the sprocket 37b. The first rotating shaft 36 rotates in synchronization with the second rotating shaft 37 by the sprocket 37b and the gears 36a, 37a. Note that the first roll 40 and the second roll 50 rotate in opposite directions.

Next, the configurations of the first roll 40 and the second roll 50 will be described in detail. In addition, henceforth, the axial direction of the 1st rotating shaft 36 and the 2nd rotating shaft 37 is only called an axial direction.
<First roll 40>
As shown in FIG. 3, the first roll 40 includes a first divided body 41, a pair of second divided bodies 42 obtained by dividing the first divided body 41 in the axial direction, and a pair of second divided bodies 42 divided in the axial direction. and a pair of third split bodies 43 split in the direction. The second divided body 42 and the third divided body 43 are laminated in this order on both sides of the first divided body 41 in the axial direction.

A plurality of first protrusions 41 a that form the first gas flow path 21 are provided on the outer peripheral surface of the first divided body 41 . Each first projecting portion 41 a extends along the axial direction and is spaced apart from each other in the circumferential direction of the first divided body 41 .

A plurality of second protrusions 42 a that form the second gas flow paths 22 are provided on the outer peripheral surface of each second divided body 42 . Each second projecting portion 42a extends spirally and is spaced from each other in the circumferential direction of the second divided body 42 . The first projecting portion 41a and the second projecting portion 42a are provided adjacent to each other in the axial direction.

A plurality of protrusions 42b that form the dimples 24 are provided on the outer peripheral surface of each second split body 42. As shown in FIG. Each protrusion 42b extends along the axial direction and is spaced apart from each other in the circumferential direction of the second split body 42 .

A plurality of third protrusions 43a forming the manifolds 11 to 16 are provided on the outer peripheral surface of each third divided body 43. As shown in FIG. The third protrusions 43a are spaced from each other in the circumferential direction of the third divided body 43. As shown in FIG. The second projecting portion 42a and the third projecting portion 43a are provided adjacent to each other in the axial direction.

Each of the divided bodies 41 to 43 is divided in the axial direction and is relatively movable. More specifically, the position of the first divided body 41, the position of the second divided body 42, and the position of the third divided body 43 with respect to the first rotating shaft 36 can be individually adjusted. The split bodies 41 to 43 are positioned relative to each other, for example, by engaging a key (not shown) and a key groove with each other.

Each of the divided bodies 41 to 43 is individually provided with a heater (not shown).
<Second roll 50>
The second roll 50 includes a first divided body 51, a pair of second divided bodies 52 obtained by dividing the first divided body 51 in the axial direction, and a pair of second divided bodies 52 obtained by dividing the second divided body 52 in the axial direction. and a third split body 53 . The second divided body 52 and the third divided body 53 are laminated in this order on both sides of the first divided body 51 in the axial direction.

The outer peripheral surface of the first divided body 51 is provided with a plurality of first recesses 51a into which the first projections 41a of the first roll 40 enter. The first recesses 51a extend along the axial direction and are spaced apart from each other in the circumferential direction of the first divided body 51 .

A plurality of second recesses 52a into which the second protrusions 42a of the first roll 40 are inserted are provided on the outer peripheral surface of each second split body 52 . The second recesses 52a extend spirally and are spaced apart from each other in the circumferential direction of the second split body 52 . The first recessed portion 51a and the second recessed portion 52a are provided adjacent to each other in the axial direction.

In addition, a plurality of depressions 52b into which the projections 42b of the first roll 40 are inserted are provided on the outer peripheral surface of each of the second divided bodies 52. As shown in FIG. The recessed portions 52b extend along the axial direction and are spaced apart from each other in the circumferential direction of the second divided body 52 .

A plurality of third recesses 53a into which the third protrusions 43a of the first roll 40 are inserted are provided on the outer peripheral surface of each third divided body 53 . The third recesses 53a are spaced from each other in the circumferential direction of the third divided body 53. As shown in FIG. The second recessed portion 52a and the third recessed portion 53a are provided adjacent to each other in the axial direction.

The divided bodies 51 to 53 are divided in the axial direction and are relatively movable. More specifically, the position of the first divided body 51, the position of the second divided body 52, and the position of the third divided body 53 with respect to the second rotating shaft 37 can be individually adjusted. The divided bodies 51 to 53 are positioned relative to each other, for example, by engaging a key (not shown) and a key groove with each other.

Each of the divided bodies 51 to 53 is individually provided with a heater (not shown).
<Extruder 60>
Next, the extruder 60 will be explained.

As shown in FIG. 4, an extruder 60 is an apparatus for extruding a mixture 100 in which a conductive carbon material 101 and a thermoplastic resin material 102 are mixed. Examples of the carbon material 101 include natural graphite such as spherical graphite. Examples of the resin material 102 include thermoplastic resin such as polypropylene resin.

The extruder 60 includes a cylinder 61, a screw 62 accommodated in the cylinder 61, a first hopper 63 that supplies the resin material 102 into the cylinder 61, and a second hopper that supplies the carbon material 101 into the cylinder 61. 64. The second hopper 64 is provided closer to the tip side of the cylinder 61 than the first hopper 63 is.

A die 65 having a discharge port 65a is provided at the tip of the cylinder 61 . A heater 66 for heating the inside of the cylinder 61 is provided on the outer peripheral portion of the cylinder 61 .

The screw 62 is connected to a driving device 67 having a motor (not shown) and is rotatably provided within the cylinder 61 . As the screw 62 rotates, the resin material 102 supplied from the first hopper 63 and the carbon material 101 supplied from the second hopper 64 are mixed, and the mixture 100 is directed toward the tip of the cylinder 61. transported by At this time, the resin material 102 is melted by being heated by the heater 66 . The mixture 100 is molded into a plate shape by being extruded from the discharge port 65a of the die 65. As shown in FIG.

<Manufacturing Method of Separator 10>
Next, a method for manufacturing the separator 10 will be described.
First, the mixture 100 extruded by the extruder 60 is supplied to the roll former 30 .

Next, the divided bodies 41 to 43 and the divided bodies 51 to 53 are heated by the heaters individually provided in the divided bodies 41 to 43 of the first roll 40 and the divided bodies 51 to 53 of the second roll 50. heat up. Thus, by melting the resin material 102 of the mixture 100, the mixture 100 is imparted with fluidity.

As shown in FIG. 5, the mixture 100 is passed between a first roll 40 and a second roll 50 to roll-form into a plate-like formed body 110 . FIG. 5 shows cross sections of the first divided body 41 and the first divided body 51 of the roll forming machine 30 . In the present embodiment, the mixture 100 is roll-formed so that the feed direction of the mixture 100 and the width direction W of the separator 10 are aligned.

The mixture 100 is rolled while flowing between the first roll 40 and the second roll 50 . At this time, the thickness of the compact 110 becomes smaller than the thickness of the mixture 100 .
By roll forming the mixture 100 , the first gas flow path 21 , the second gas flow paths 22 and 23 , the manifolds 11 to 16 and the dimples 24 are formed on one side surface of the compact 110 . At this time, the entire first gas flow path 21 is formed by the first projecting portion 41a and the first recessed portion 51a. Further, the second gas flow paths 22 and 23 are formed by the second protrusions 42a and the second recesses 52a. Each dimple 24 is formed by each protrusion 42b and each recess 52b. Further, each of the manifolds 11 to 16 is formed by each of the third projections 43a and each of the third recesses 53a.

Finally, the separator 10 is manufactured by cooling the compact 110 and cutting it into a predetermined shape.
The operation of this embodiment will be described.

For example, the first roll 40 in which the first divided body 41 and the second divided body 42 are integrally provided, and the second roll 50 in which the first divided body 51 and the second divided body 52 are integrally provided are used. In this case, it becomes difficult to change the relative position between the first divided body 41 and the second divided body 42 and the relative position between the first divided body 51 and the second divided body 52 . Therefore, in roll forming in which the mixture 100 is caused to flow between the first roll 40 and the second roll 50, it may be difficult to ensure the dimensional accuracy of the gas flow path portion 20.

In this regard, according to the method of manufacturing the separator 10 of the present embodiment, the positions of the divided bodies 41 and 42 with respect to the first rotating shaft 36 and the positions of the divided bodies 51 and 52 with respect to the second rotating shaft 37 are individually adjusted. By doing so, the dimensional accuracy of the gas flow path portion 20 can be ensured.

Effects of the present embodiment will be described.
(1) As the first roll 40, the first divided body 41 and the second divided body 42 are provided, and the position of the first divided body 41 and the position of the second divided body 42 with respect to the first rotating shaft 36 are individually adjusted. Use what you can. The second roll 50 includes a first divided body 51 and a second divided body 52, and the position of the first divided body 51 and the position of the second divided body 52 with respect to the second rotating shaft 37 are individually adjustable. Use The first gas flow path 21 is formed by the first protruding portion 41 a of the first divided body 41 and the first concave portion 51 a of the first divided body 51 . The second gas passages 22 and 23 are formed by the second projecting portion 42 a of the second split body 42 and the second recessed portion 52 a of the second split body 52 .

According to such a method, the dimensional accuracy of the separator 10 can be improved because the above-described effects are achieved.
(2) Use the first roll 40 in which the first protruding portion 41a and the second protruding portion 42a are adjacent to each other in the axial direction. A second roll 50 is used in which the first recessed portion 51a and the second recessed portion 52a are adjacent to each other in the axial direction.

According to this method, the first gas flow path 21 formed by the first protrusion 41a and the first recess 51a and the second gas flow path 22 formed by the second protrusion 42a and the second recess 52a , 23 are connected. Here, by individually adjusting the positions of the divided bodies 41 and 42 with respect to the first rotating shaft 36 and the positions of the divided bodies 51 and 52 with respect to the second rotating shaft 37, the dimensions of the gas flow paths 21 to 23 Accuracy can be ensured. As a result, the gas flow paths 21 to 23 can be smoothly communicated with each other.

(3) The first protrusion 41a and the first recess 51a form the entire first gas flow path 21, and the second protrusion 42a and the second recess 52a form the entire second gas flow paths 22 and 23. do.

For example, when the middle portion of the first gas flow path 21 is formed by the boundary portion between the first divided body 41 and the second divided body 42 adjacent to each other, the dimensional accuracy of the first gas flow path 21 depends on these It depends on the positional accuracy of the split bodies 41 and 42 .

In this respect, according to the method described above, each of the gas flow paths 21 to 23 includes a portion formed by the boundary portion between the first divided body 41 and the second divided body 42 adjacent to each other and a portion formed by the boundary portion between the first divided body 41 and the second divided body There is no portion formed by the boundary portion between the first split body 51 and the second split body 52 that meet. Accordingly, by individually positioning the divided bodies 41 and 42 and the divided bodies 51 and 52, the dimensional accuracy of the gas flow paths 21 to 23 can be secured individually. Therefore, it becomes easier to improve the dimensional accuracy of the separator 10 .

(4) As the first roll 40, one provided with the first divided body 41, the second divided body 42, and the third divided body 43 is used. As the second roll 50, one provided with a first divided body 51, a second divided body 52, and a third divided body 53 is used.

According to such a method, when it becomes necessary to change the shape of a portion of the gas flow passage portion 20, it is sufficient to change the shape of only the divided body that forms the portion. In addition, replacement and maintenance of each of the divided bodies 41 to 43 and each of the divided bodies 51 to 53 can be performed individually.

(5) The mixture 100 is roll-formed while the first roll 40 and the second roll 50 are heated.
According to such a method, since the resin material 102 is melted, the mixture 100 can be rolled while being fluidized. Therefore, variations in the thickness of the separator 10 can be suppressed.

<Change example>
This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

- The 1st division body 41 may have the 1st protrusion part 41a and the 2nd protrusion part 42a, and each 2nd division body 42 may have only the 2nd protrusion part 42a. According to such a first roll 40, the first gas flow path 21 is formed by the first projecting portion 41a, and the second projecting portion 42a of the first divided body 41 and the second projecting portion of each second divided body 42 are formed. Each of the second gas flow paths 22 and 23 is formed by the portion 42a. In this case, a portion formed by a boundary portion between the first divided body 41 and the second divided body 42 exists in the middle of the second gas flow paths 22 and 23 .

- The 1st division body 41 may have only the 1st protrusion part 41a, and each 2nd division body 42 may have the 1st protrusion part 41a and the 2nd protrusion part 42a. According to such a first roll 40, the first gas flow path 21 is formed by the first projecting portion 41a of the first divided body 41 and the first projecting portion 41a of each second divided body 42. Each of the second gas flow paths 22 and 23 is formed by the two protrusions 42a. In this case, a portion formed by a boundary portion between the first divided body 41 and the second divided body 42 exists in the middle of the first gas flow path 21 .

- A roll forming machine 30 in which the first divided body 41 and the first divided body 51 have the same configuration and the second divided body 42 and the second divided body 52 have the same configuration can also be employed.
・As the first roll 40, a roll including the first divided body 41 and the second divided body 42 is used, and as the second roll 50, the first divided body 51 and the second divided body 52 are integrally provided. You can also use things. At this time, a cylindrical roll having a smooth outer peripheral surface can also be used as the second roll 50 .

・As the first roll 40, the one in which the first divided body 41 and the second divided body 42 are integrally provided is used, and as the second roll 50, the first divided body 51 and the second divided body 52 are provided. You can also use things.

In the present embodiment, the mixture 100 is roll-formed so that the feeding direction of the mixture 100 and the width direction W of the separator 10 are aligned. , the mixture 100 may be roll-formed. In this case, for example, in the central portion of the separator 10 in the width direction, the cooling water supply manifold 13, the second gas flow path 22, the first gas flow path 21, the second gas flow path 23, and the A cooling water discharge manifold 14 may be formed.

The carbon material 101 may be any conductive carbon material, and may be, for example, artificial graphite or natural graphite other than spherical graphite.
- The resin material 102 may be a thermoplastic resin other than the polypropylene resin, or may be a thermosetting resin.

In the present embodiment, as an example of a fuel cell separator, a method for manufacturing the separator 10 having the gas channel portion 20 through which the oxidizing gas flows has been described. A similar method can be applied to

DESCRIPTION OF SYMBOLS 10... Separator 21... 1st gas flow path 22... 2nd gas flow path 23... 2nd gas flow path 36... 1st rotating shaft 37... 2nd rotating shaft 40... 1st roll 41... 1st divided body 41a... 3rd 1 projecting portion 42 second divided body 42 a second projecting portion 43 third divided body 43 a third projecting portion 50 second roll 51 first divided body 51 a first recess 52 second divided body 52 a Second recess 53 Third divided body 53a Third recess 100 Mixture 101 Carbon material 102 Resin material 110 Molded body

Claims (3)

A mixture in which a conductive carbon material and a resin material are mixed is passed between a pair of rolls that rotate while being fitted on a pair of parallel rotating shafts, respectively, to roll-form into a plate-like formed body. In addition, a first gas flow path through which reaction gas flows and a second gas flow path extending in a direction different from the direction in which the first gas flow path extends are formed on at least one side surface of the molded body. A method for manufacturing a battery separator, comprising:
As at least one roll of the pair of rolls, a first divided body and a second divided body obtained by dividing the first divided body in the axial direction of the rotating shaft are provided, and the first divided body with respect to the rotating shaft is provided. Using a body position and a position of the second divided body that are individually adjustable,
A first projecting portion projecting from the outer peripheral surface of the first divided body forms the first gas flow channel, and a second projecting portion projecting from the outer peripheral surface of the second divided body forms the second gas flow channel. Form,
A method for producing a fuel cell separator. The first projecting portion and the second projecting portion are adjacent to each other in the axial direction,
2. A method for manufacturing the fuel cell separator according to claim 1. The first protrusion forms the entire first gas flow path, and the second protrusion forms the entire second gas flow path,
3. The method of manufacturing the fuel cell separator according to claim 1 or 2.

Images