JP4878419B2 - Membrane / electrode assembly trim device for fuel cells - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a fuel cell membrane / electrode assembly trim apparatus improved for reliably cutting a polymer electrolyte membrane with a small load.
[0002]
[Prior art]
A fuel cell is a battery that utilizes the reverse principle of water electrolysis and can obtain electricity in the process of obtaining water by reacting hydrogen and oxygen. In general, since the fuel gas is replaced by hydrogen and the air or oxidant gas is replaced by oxygen, the terms fuel gas, air, and oxidant gas are often used.
[0003]
As such a fuel cell, for example, Japanese Unexamined Patent Publication No. 2000-123848 “Fuel Cell” is known.
The cells of the fuel cell will be described with reference to the following diagram created based on FIGS. 1 and 2 of the publication. In addition, the code | symbol was reassigned.
[0004]
FIG. 8 is a cross-sectional view of a cell of a fuel cell. In the cell 100, an anode side electrode 102 and a cathode side electrode 103 are bonded to both surfaces of an electrolyte membrane 101, and the anode side electrode 102 and the cathode side electrode 103 are connected. The separator 104 is sandwiched between two separators 104 and 105, a plurality of flow channel grooves 106 for supplying hydrogen gas as fuel to the anode side electrode 102 are formed in the separator 104, and the separator 105 has an oxidant to the cathode 103. A plurality of flow channel grooves 107 for supplying oxygen gas are formed, and a desired voltage is obtained by stacking a large number of the cells 100.
Here, 111 and 112 are sealing materials (gaskets) for sealing between the electrolyte membrane 101 and the separators 104 and 105.
[0005]
The electrolyte membrane 101 is a polymer electrolyte membrane (PEM) made of a polymer compound. This electrolyte membrane 101 is hereinafter referred to as PEM101.
Further, the PEM 101, the anode side electrode 102, and the cathode side electrode 103 constitute a membrane / electrode assembly (MEA: Membrane Electrode Assembly) 108. This membrane / electrode assembly 108 is hereinafter referred to as MEA 108.
[0006]
The above publication does not describe a method of manufacturing the MEA 108. However, in general, (1) the anode side having a smaller area than the PEM is provided on each of the front and back surfaces of the PEM that is cut larger than the final shape to be molded. A method is known in which the electrode 102 and the cathode-side electrode 103 are pressure-bonded, and (2) the edge of the PEM is cut (trimmed) with a trim blade to be finally formed.
[0007]
[Problems to be solved by the invention]
The present inventors tried the above production using the MEA 108 production apparatus, but the problems shown in FIGS. 9 and 10 occurred during the trimming of the PEM shown in (2).
FIGS. 9A and 9B are first explanatory views for explaining the MEA trim device and the trim processing procedure.
In (a), the PEM 101 a having electrodes bonded to both sides is placed on the mounting table 121. (In order to distinguish from the PEM 101 after cutting, the sign of the PEM before cutting is set to 101a for the sake of convenience. Next, the trim blade 123 in which the blade edge 122 is waved is lowered from above the PEM 101a as indicated by the white arrow. (For convenience of explanation, the amount of waviness of the blade edge 122 is exaggerated.)
[0008]
In (b), the trim blade 123 cuts the PEM 101a. However, due to the undulation of the blade edge 122, the cross-hatched portion of the cross section of the PEM 101a is not cut.
[0009]
In order to completely cut the PEM 101a, the trim blade 123 is pressed against the PEM 101a with a larger pressing force, and the load acting on the trim blade 123 is increased. Therefore, the strength of the trim blade 123 is increased to withstand this load. It is necessary to increase the size of the cylinder device that presses the trim blade 123.
[0010]
FIGS. 10A and 10B are second explanatory diagrams for explaining the MEA trim device and the trim processing procedure.
In (a), the PEM 101 a having electrodes bonded to both sides is placed on the mounting table 121.
[0011]
The trim blade 125 is lowered from above the PEM 101a as indicated by the white arrow.
For example, when the parallelism between the upper surface of the mounting table 121 and the blade edge 126 of the trim blade 125 is large (the blade edge 126 is inclined by an angle θ with respect to the upper surface of the mounting table 121), in FIG. When the PEM 101a is cut, the cross-hatched portion of the cross section of the PEM 101a is not cut.
Therefore, in order to cut the PEM 101a, it is necessary to apply a larger pressing force to the trim blade 125 as described in FIG.
[0012]
Accordingly, an object of the present invention is to reliably cut a polymer electrolyte membrane with a small load by improving a membrane-electrode assembly trim device for a fuel cell.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the first aspect of the present invention is to trim a membrane / electrode assembly formed by bonding a carbon electrode having a smaller area on both sides of a polymer electrolyte membrane, and trim the edges of the polymer electrolyte membrane. In a fuel cell membrane / electrode assembly trim device for cutting with a blade, the trim device comprises a lower press mold for placing the membrane / electrode assembly, and the trim blade disposed on the lower surface of the press lower die . constituted by an upper mold press, the press lower mold, a first receiving member made of an elastic body provided a wider area than the membrane electrode assembly, harder than the first receiving member on the first receiving member By attaching a second receiving member made of a soft material and receiving the edge of the polymer electrolyte membrane, the cutting force of the trim blade is transmitted in the order of the edge of the polymer electrolyte membrane, the second receiving member, and the first receiving member. It is characterized by that.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a cross-sectional view of a fuel cell membrane / electrode assembly trim apparatus according to the present invention. A membrane / electrode assembly trim apparatus 10 (hereinafter referred to as “MEA trim apparatus 10”) is a carbon-made carbon paper. A trim on which a polymer electrolyte membrane 13a (hereinafter referred to as “PEM13a” is referred to as “PEM13a”. The PEM before cutting is referred to as PEM13a in this way for distinction from PEM13 after cutting), which will be described later), is obtained by pressing the electrodes 11 and 12 to each surface. The lower die 14, the trim upper die 16 having a trim blade 15 for trimming or trimming the edge of the PEM 13 a, and the adsorption holding connected to the trim upper die 16 for adsorbing and holding the carbon electrode 12 and the PEM 13 a. It comprises a device 17 and a cylinder device 18 for lowering the trim upper mold 16.
The two carbon electrodes 11 and 12 are the same, but are separated from each other for convenience.
[0020]
The trim lower mold 14 includes a placement part 21 that also serves as a positioning part of the PEM 13a, a lower mold support part 22 that supports the placement part 21, and a lower mold suction part 23 that sucks the peripheral edge of the PEM 13a.
[0021]
The mounting portion 21 includes a lower receiving member 25 as a first receiving member provided on the bottom portion 22a of the lower supporting portion 22, and an upper portion as a second receiving member on which the PEM 13a is placed by being disposed above the lower receiving member 25. The positioning receiving portion 26 includes a positioning housing portion 27 for positioning the carbon electrode 11 at the center of the upper receiving member 26, and a resin plate 28 above the lower receiving member 25 and below the positioning housing portion 27. Is arranged.
[0022]
The lower receiving member 25 is made of a foam-like elastic body such as polyurethane, and the upper receiving member 26 is made of a soft material such as a PET (polyethylene terephthalate) material. The resin plate 28 is a member for preventing the carbon electrode 11 from coming into contact with the lower receiving member 25 and preventing the metal ion from attaching to the carbon electrode 11 when the metal ion is attached to the lower receiving member 25. It is.
[0023]
If metal ions adhere to the carbon electrode 11, the metal ions and electrons are combined, and a metal is deposited on the carbon electrode 11. As a result, the deposited metal may hinder the reaction between hydrogen and oxygen, which may reduce the performance of the fuel cell.
[0024]
The lower mold suction part 23 has suction holes 31 (... are shown in plural, the same applies hereinafter) opened in the mounting part 21 and joints 32. The connecting pipes 33... Are connected via a suction pipe 31... And connected to a suction device (not shown) to suck air from the suction holes 31. Adsorbs.
[0025]
The trim blade 15 has a substantially rectangular shape in plan view, and is a member that cuts off the peripheral edge of the PEM 13 a outside the carbon electrodes 11 and 12.
The trim upper die 16 includes a trim blade 15 and a trim blade fixing portion 35 that fixes the trim blade 15.
[0026]
The suction holding device 17 is connected to the trim blade fixing portion 35 via a rod 36... And trimmed in order to press and position the PEM 13 a during trimming of the PEM 13 a and to prevent lateral displacement during conveyance after trimming of the PEM 13 a. A spring 37 is interposed between the blade fixing portion 35 and pressed downward. A presser portion 41 that presses the PEM 13a during trimming, a first recess 42 provided inside the presser portion 41, The pad 43 made of a porous material disposed in the first recess 42, the upper mold first adsorption portion 44 that adsorbs the carbon electrode 12 through the pad 43, and the PEM 13a at the position of the presser portion 41 described above. The upper mold second adsorption part 45 adsorbs. In addition, 17a ... is a guide hole provided in the trim blade fixing portion 35 for guiding the rods 36 ..., 17b ... is a through hole for passing through the connecting pipes 48, 52 ..., 43a is This is a second recess provided in the lower part of the pad 43 for accommodating the carbon electrode 12.
[0027]
The pad 43 is a porous resin material, has air permeability, and is also for preventing metal ions from adhering to the carbon electrode 12, similar to the resin plate 28 of the trim lower mold 14 described above. .
The upper mold first suction portion 44 includes a suction hole 47 formed in the bottom of the first recess 42 and a connection pipe 48 connected to the suction hole 47 via a joint 32. The connection pipe 48 is illustrated in FIG. By connecting to a suction device (not shown), the air in the first recess 42 is sucked through the pad 43 and the suction hole 47 to suck the carbon electrode 12.
[0028]
The upper mold second suction part 45 includes suction holes 51 formed in the holding part 41, and connection pipes 52 connected to the suction holes 51 through joints 32, respectively. By connecting these connecting pipes 52 to a suction device (not shown), air is sucked from the suction holes 51 to suck the PEM 13a.
[0029]
The cylinder device 18 includes a cylinder main body 61, a piston (not shown) movably accommodated in the cylinder main body 61, a piston rod 62 attached to the piston, and a pressing portion 63 attached to the lower end of the piston rod 62. Become.
[0030]
Next, a procedure for manufacturing the fuel cell including the MEA trim processing by the MEA trim device 10 described above will be described.
FIG. 2 is a flowchart illustrating the flow of manufacturing a fuel cell including trim processing by the MEA trim device according to the present invention. STXX indicates a step number.
ST01: The PEM with the carbon electrode attached is placed on the lower trim mold.
ST02 ... Position the PEM.
ST03 ... Trim PEM and build MEA.
[0031]
ST04 ... The MEA is transported to the stacking station.
ST05 ... A sealing material is applied to the separator.
ST06 ... A separator coated with a sealing material and MEA are laminated to form a cell.
Then, by stacking a plurality of these cells, a fuel cell having a desired voltage is completed.
Each process of above-mentioned ST01-ST03 is explained in full detail below.
[0032]
FIGS. 3A to 3C are first operation views for explaining the operation of the MEA trim device according to the present invention. FIGS. 3A and 3B are plan views, and FIG. It is c line sectional drawing.
First, in (a), PEM13a which stuck carbon electrodes 11 and 12 (carbon electrode 11 is the back side of PEM13a) is mounted on mounting part 21 of trim lower mold 14. FIG.
[0033]
In (b) and (c), the two sides of the carbon electrode 11 are brought into contact with the two side walls 27 a and 27 b of the positioning housing portion 27 of the mounting portion 21 to position the carbon electrode 11 with respect to the mounting portion 21. (For convenience of explanation, carbon electrode 12 is not shown in (b).)
[0034]
4 (a) and 4 (b) are second operation diagrams for explaining the operation of the MEA trim device according to the present invention.
After the positioning of the PEM 13a with respect to the mounting portion 21, in FIG. 4 (a), the lower mold suction portion 23 starts sucking the peripheral portion of the PEM 13a from the state of FIG. The device 18 is operated, the pressing portion 63 of the cylinder device 18 is lowered, and the trim blade fixing portion 35 of the trim upper mold 16 is pushed downward.
As a result, the carbon electrode 12 is housed in the second recess 43a, the PEM 13a is pressed by the elastic force of the spring 37 by the pressing portion 41 of the suction holding device 17, and then the peripheral edge of the PEM 13a is cut by the trim blade 15. To do.
[0035]
During and after cutting the peripheral edge of the PEM 13a, the upper electrode first adsorption part 44 adsorbs the carbon electrode 12 and the upper mold second adsorption part 45 adsorbs the PEM 13a. Thereafter, in (b), the pressing portion 63 of the cylinder device 18 is raised, and the trim upper die 16 is raised. The upper mold first adsorption unit 44 and the upper mold second adsorption unit 45 continue to adsorb the carbon electrode 12 and the PEM 13.
[0036]
The frame-shaped member 13b that has become unnecessary by cutting the PEM 13a is removed from the trim lower mold 14 after the adsorption by the lower mold adsorption section 23 is stopped.
Here, the joined body of the PEM 13 and the carbon electrodes 11 and 12 with the peripheral edge cut is referred to as a membrane / electrode assembly 65, that is, MEA 65. In addition, in order to distinguish MEA before cutting | disconnecting a peripheral part from MEA65, it is set as MEA65a.
[0037]
FIG. 5 is a third action view for explaining the action of the MEA trim device according to the present invention. In the plan view showing the PEM 13a, the position indicated by the imaginary line 67 is cut by the trim blade 15 shown in FIG. 4 (a). It shows that.
The cutting position is a portion outside the contour of the carbon electrodes 11 and 12 (the carbon electrode 11 on the back side is not shown).
[0038]
FIG. 6 is a fourth operation view for explaining the operation of the MEA trim device according to the present invention.
When cutting the peripheral edge of the PEM 13a, even if the cutting edge 15a of the trim blade 15 is wavy, for example, the upper receiving member 26 of the trim lower mold 14 is a soft material. The upper edge of the undulation of the blade edge 15a, for example, the point A can be made lower than the lower surface of the PEM 13a, and the PEM 13a can be cut by the entire blade edge 15a.
Therefore, the PEM 13a can be reliably cut even with a relatively small load.
[0039]
FIGS. 7A and 7B are fifth operation diagrams for explaining the operation of the MEA trim device according to the present invention.
In (a), for example, the cutting edge 15a of the trim blade 15 of the trim upper mold 16 is inclined by an angle θ with respect to the upper surface of the mounting portion 21 of the trim lower mold 14 (upper surface of the upper receiving member 26), and the cutting edge 15a. When the PEM 13a is cut as shown in (b) when the parallelism between the placing portion 21 and the cutting edge 15a of the trim blade 15 is large. Thus, the upper surface of the upper receiving member 26 and the PEM 13a follows the cutting edge 15a of the trim blade 15 so that the cutting edge 15a hits the entire surface of the PEM 13a. Therefore, the PEM 13a can be reliably cut with a small load.
[0040]
As described above with reference to FIG. 1, first, the present invention first targets the MEA 65a formed by bonding the carbon electrodes 11 and 12 having a smaller area on both sides of the PEM 13a, and trims the edges of the PEM 13a with the trim blade 15. In the fuel cell membrane / electrode assembly trim device 10 to be cut, the trim device 10 includes a trim lower die 14 on which the MEA 65 a is placed and a trim upper die 16 having a trim blade 15. The lower receiving member 25 having a larger area than the MEA 65a is provided, and the upper receiving member 26 that receives the edge of the PEM 13a is attached to the lower receiving member 25, so that the cutting force of the trim blade 15 is changed to the edge of the PEM 13a, the upper receiving member 26, and the lower receiving member. The structure is such that the members 25 are transmitted in order.
[0041]
Since the lower receiving member 25 and the upper receiving member 26 receive the cutting force of the trim blade 15, for example, the lower receiving member 25 and the upper receiving member 26 can be made of different materials. If the PEM 13a is cut by the trim blade 15, the lower receiving member 25 or the upper receiving member 26 is deformed so as to follow the shape of the cutting edge 15a of the trim blade 15 by making a difference in hardness between the upper receiving member 26 and the upper receiving member 26. Cutting can be performed while the lower receiving member 25 or the upper receiving member 26 absorbs the assembly error between the trim lower mold 14 and the trim upper mold 16, the assembly error of the trim blade 15 with respect to the trim upper mold 16, and the like.
[0042]
That is, if the lower receiving member 25 or the upper receiving member 26 is made relatively hard, the cutting force can be reliably transmitted to the PEM 13a while absorbing a relatively small deviation such as a dimensional error of the trim blade 15 itself.
Further, if the lower receiving member 25 or the upper receiving member 26 is softened, a large deviation such as an assembly error between the trim lower mold 14 and the trim upper mold 16 and an assembly error of the trim blade 15 with respect to the trim lower mold 14 is absorbed. be able to.
[0043]
Therefore, for example, by combining the lower receiving member 25 and the upper receiving member 26 having different hardnesses as described above, it is possible to absorb the dimensional errors and assembling errors of the respective parts and apply the entire trim blade 15 to the PEM 13a. In addition, the cutting force of the trim blade 15 can be reliably transmitted to the lower receiving member 25 and the upper receiving member 26. As a result, the PEM 13a can be favorably cut with a small load.
[0044]
Thereby, since a big load does not act on the trim blade 15, abrasion of the trim blade 15 can be suppressed. In addition, the strength of each part of the trim blade 15 and the MEA trim device 10 is small, and it is not necessary to increase the size of the cylinder device 18 that presses the trim blade 15. Therefore, the manufacturing cost of the MEA trim device 10 can be reduced. .
[0045]
Secondly, the present invention is characterized in that the lower receiving member 25 is an elastic body as described with reference to FIGS.
Even if the parallelism between the cutting edge 15a of the trim blade 15 and the trim lower mold 14 is increased by using the lower receiving member 25 as an elastic body, the lower receiving member 25 is cut when the trim blade 15 cuts the edge of the PEM 13a. The member 25 bends so that the entire trim blade 15 can be applied to the PEM 13 a, and the PEM 13 a can be cut evenly by the entire trim blade 15.
[0046]
Third, the present invention is characterized in that the upper receiving member 26 is made of a soft material harder than the lower receiving member 25 as described with reference to FIGS. 1 and 6.
Since the upper receiving member 26 is made of a soft material, even when the cutting edge 15a of the trim blade 15 is wavy and the cutting edge 15a is not straight, the trim blade 15 can be moved upward when the trim blade 15 cuts the edge of the PEM 13a. The receiving member 26 can be bitten, the entire trim blade 15 hits the PEM 13 a, and the PEM 13 a can be cut evenly by the entire trim blade 15.
[0047]
In the present invention, the first receiving member and the second receiving member are used to absorb dimensional errors and assembly errors of each part of the MEA trim device at the time of PEM cutting. The above error may be absorbed by attaching the trim blade 15 to the trim 16 via a universal joint such as a ball joint or attaching the trim blade 15 to the trim upper die 16 via an elastic body or a soft material.
[0048]
【Effect of the invention】
The present invention exhibits the following effects by the above configuration.
The fuel cell membrane / electrode assembly trim device according to claim 1 comprises a lower press mold on which the membrane / electrode assembly is placed and a press upper mold provided with a trim blade. A first receiving member having a larger area is provided, and a second receiving member that receives the edge of the polymer electrolyte membrane is attached to the first receiving member, whereby the cutting force of the trim blade is adjusted to the edge of the polymer electrolyte membrane, the second receiving member. Since it is structured to transmit in the order of the member and the first receiving member, for example, the first receiving member and the second receiving member can be made of different materials, and the first receiving member and the second receiving member If there is a difference in hardness, when the polymer electrolyte membrane is cut with a trim blade, the first receiving member or the second receiving member may be deformed to follow the shape of the edge of the trim blade, or the lower trim and upper trim The first is the assembly error with the mold and the trim blade assembly error with respect to the upper mold. It is possible to perform the absorbed while cutting with only member or the second receiving member.
[0049]
Therefore, the entire trim blade can be applied to the polymer electrolyte membrane, and the cutting force of the trim blade can be reliably transmitted to the polymer electrolyte membrane, the second receiving member, and the first receiving member. As a result, the polymer electrolyte membrane can be reliably cut with a small load.
[0050]
In addition, fuel cell membrane electrode assembly trimming apparatus according to claim 1, the first receiving member, since an elastic body, even parallelism between the cutting edge of trimming knife and trim lower mold side is increased When the edge of the polymer electrolyte membrane is cut with the trim blade, the first receiving member bends so that the entire trim blade can be applied to the polymer electrolyte membrane, and the polymer electrolyte membrane can be uniformly applied to the entire trim blade. Can be cut.
[0051]
In addition, in the fuel cell membrane / electrode assembly trim device according to claim 1 , since the second receiving member is made of a soft material harder than the first receiving member, the cutting edge of the trim blade is swelled and the cutting edge is Even when the edge of the polymer electrolyte membrane is cut with the trim blade even when it is not in a straight line, the trim blade can bite into the second receiving member, the entire trim blade hits the polymer electrolyte membrane, The trim blade can be cut evenly.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a membrane / electrode assembly trim device for a fuel cell according to the present invention. FIG. 3 is a first operation diagram for explaining the operation of the MEA trim device according to the present invention. FIG. 4 is a second operation diagram for explaining the operation of the MEA trim device according to the present invention. FIG. 6 is a fourth action diagram for explaining the action of the MEA trim device according to the present invention. FIG. 7 is a fifth action diagram for explaining the action of the MEA trim device according to the invention. 8] Cross-sectional view of fuel cell [Fig. 9] Fig. 9 is a first explanatory diagram explaining the trim device and trim processing procedure of the membrane-electrode assembly. [Fig. 10] Trim device of the membrane-electrode assembly and trim procedure. Second explanatory diagram explaining the explanation 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 10 ... Membrane / electrode assembly trim device, 11, 12 ... Carbon electrode, 13 ... Polymer electrolyte membrane, 13a ... Polymer electrolyte membrane before trimming, 14 ... Press lower die (trim lower die), 15 ... Trim blade, 16: Press upper mold (trim upper mold), 25: First receiving member (lower receiving member), 26: Second receiving member (upper receiving member), 65: Membrane / electrode assembly, 65a: Film before trimming Electrode assembly.

Claims (1)

The membrane / electrode assembly (65a) formed by bonding the carbon electrodes (11, 12) having a smaller area on both sides of the polymer electrolyte membrane (13a) is to be trimmed, and the edge of the polymer electrolyte membrane (13a) is trimmed. In the fuel cell membrane / electrode assembly trim device (10) for cutting the fuel cell with the trim blade (15) ,
The trim device (10) includes a press lower die (14) on which the membrane / electrode assembly (65a) is placed, and a press having the trim blade (15) provided on the lower surface of the press lower die (14). Consists of the upper mold (16) ,
A first receiving member (25) made of an elastic body having a larger area than the membrane-electrode assembly (65a ) is provided on the lower press die (14) , and the first receiving member (25) is provided with the first receiving member (25). By attaching a second receiving member (26) made of a soft material harder than the first receiving member (25) and receiving the edge of the polymer electrolyte membrane (13a) , the cutting force of the trim blade (15) is reduced to the polymer electrolyte. A membrane / electrode assembly trim device for a fuel cell, characterized in that it is structured so as to transmit the edge of the membrane (13a) , the second receiving member (26) , and the first receiving member (25) in this order.

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