Apparatus and method for manufacturing laminated structure

Abstract

To provide an apparatus and a method for manufacturing a laminated structure capable of performing a short-circuit inspection of an electrolyte membrane during the production of a membrane electrode structure, thereby achieving a reduction in manufacturing time and cost.SOLUTION: The apparatus includes: a pair of opposing crimping members (21); a cushioning material (24) with flexibility and electrical conductivity in a site of one of the crimping members (21), which is a normal-temperature crimping member 22, the site facing the other of the crimping members (21), which is the heated crimping member (23); crimping means (20A) for sandwiching and pressing a plurality of laminated sheet-like members between the normal-temperature crimping member (22) and the heated crimping member (23) so as to crimp the sheet members together into a membrane electrode assembly (10); and a short-circuit inspection circuit (30) for detecting the presence or absence of a short-circuit part within the membrane electrode assembly (10) during the process in which the crimping means (20A) integrally crimps the plurality of sheet-like members to form the membrane electrode assembly (10).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a manufacturing apparatus and method for a laminated structure, such as a membrane electrode assembly that constitutes a fuel cell. [Background technology]

[0002] Conventionally, a method using thermocompression bonding, as shown in Patent Document 1, has been widely used to manufacture membrane electrode assemblies that constitute fuel cells. Furthermore, when manufacturing a membrane electrode assembly, an inspection (short-circuit inspection) to determine whether insulation between the anode and cathode is ensured is carried out by a method such as that shown in Patent Document 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6442544 [Patent Document 2] JP 2023-40519 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional methods for manufacturing laminated structures such as membrane electrode assemblies, the manufacturing equipment and the inspection equipment are configured separately, and therefore the manufacturing process and the inspection process are provided separately, which has hindered efforts to reduce the manufacturing time and the number of steps.

[0005] The present invention has been made in consideration of the above points, and aims to provide a manufacturing apparatus and manufacturing method for a laminated structure that can shorten manufacturing time and reduce costs by enabling short-circuit testing of an electrolyte membrane during the manufacture of a membrane electrode assembly. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the manufacturing apparatus for a laminated structure according to the present invention is characterized in that it comprises a pair of crimping members arranged opposite each other, and a cushioning material having flexibility and conductivity in a portion of at least one of the pair of crimping members facing the other crimping member, a crimping means for clamping and pressing a plurality of stacked sheet-like members between the one crimping member and the other crimping member to crimp them together into a laminated structure, and a short-circuit inspection circuit for detecting the presence or absence of short circuits within the laminated structure during the process in which the crimping means crimps the plurality of sheet-like members together to form the laminated structure. [Effects of the Invention]

[0007] According to the present invention, short-circuit inspection of the electrolyte membrane can be carried out at the same time as manufacturing the membrane electrode assembly, thereby realizing a reduction in manufacturing time and cost. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is an exploded perspective view showing the configuration of a membrane electrode assembly. [Figure 2] 1 is a schematic diagram showing the configuration of a main part of a manufacturing apparatus for a laminated structure according to an embodiment of the present invention. [Figure 3] 1 is a perspective view showing the configuration of a main part of a manufacturing apparatus for a laminated structure according to an embodiment of the present invention; [Figure 4] FIG. 10 is a schematic diagram showing the configuration of the main part of a manufacturing apparatus for a laminated structure according to a first modified example. [Figure 5] FIG. 10 is a schematic diagram showing the configuration of a main part of a manufacturing apparatus for a laminated structure according to a second modified example. [Figure 6] FIG. 10 is a perspective view of the essential configuration showing a manufacturing apparatus for a laminated structure according to a second modified example. [Figure 7] FIG. 10 is a schematic diagram showing the configuration of the main part of a manufacturing apparatus for a laminated structure according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] A laminated structure manufacturing apparatus SA according to one embodiment of the present invention will be described in detail with reference to FIGS. In the description, the same elements are given the same reference numerals and redundant description will be omitted. In the following description, unless otherwise specified, "upper" and "lower" refer to "upper" and "lower" in the vertical direction of the manufacturing equipment.

[0010] Before describing the manufacturing apparatus SA, the configuration of a membrane electrode assembly 10, which is a laminated structure, will be described (see FIG. 1). The membrane electrode assembly 10 constitutes a cell (not shown), which is a power generating element of a fuel cell (not shown), together with a pair of separators (not shown). The membrane electrode assembly 10 is sandwiched between a pair of separators with its outer periphery supported by a frame member 11 .

[0011] The membrane electrode assembly 10 (laminated structure) includes a frame member 11, a polymer electrolyte membrane 12, an anode electrode 13, and a cathode electrode . The frame member 11 is made of a sheet-like resin material and has a rectangular frame shape with a rectangular hole 11a opening in the center. The polymer electrolyte membrane 12 is made of a sheet-like cation exchange membrane and is housed in a rectangular hole 11 a of the frame member 11 . The polymer electrolyte membrane 12 and the frame member 11 are sandwiched between the anode electrode 13 and the cathode electrode 14, and are tightly bonded to each other.

[0012] That is, the anode 13 constitutes one of a pair of electrodes, and the cathode 14 constitutes the other of the pair of electrodes. The anode 13 is made of a sheet-like member and has a rectangular shape that is smaller than the outer shape of the frame member 11 and larger than the rectangular hole 11a. The anode 13 is in close contact with and bonded to the polymer electrolyte membrane 12 and one surface of the frame member 11 . The anode 13 has a central portion that is in close contact with and bonded to the polymer electrolyte membrane 12 , and a peripheral portion that is in close contact with and bonded to the frame portion of the frame member 11 .

[0013] The cathode electrode 14 is made of a sheet-like member and has a rectangular shape that is smaller than the outer shape of the frame member 11 and larger than the rectangular hole 11a. The cathode 14 is in close contact with and bonded to the other surface of the polymer electrolyte membrane 12 and the frame member 11 . The cathode electrode 14 has a central portion that is in close contact with and bonded to the polymer electrolyte membrane 12 , and a peripheral portion that is in close contact with and bonded to the frame portion of the frame member 11 . That is, the membrane electrode assembly 10 (laminate structure) is constructed as a single member by laminating a plurality of sheet-like members, closely adhering and joining them together. For convenience of explanation, the sheet members stacked one upon the other will be referred to as a laminate, and the laminate in which each sheet member is joined to one member will be referred to as a membrane electrode assembly 10.

[0014] Next, the manufacturing apparatus SA for manufacturing a laminated structure of this embodiment will be described (see FIGS. 2 and 3). The laminate structure manufacturing apparatus SA performs adhesion and bonding of the frame member 11, polymer electrolyte membrane 12, anode electrode 13, and cathode electrode 14, and also performs a short-circuit test, in the manufacture of the membrane electrode assembly 10 described above. For this reason, the manufacturing apparatus SA of this embodiment is provided with a crimping means 20A and a short-circuit inspection circuit 30.

[0015] The pressure bonding means 20A includes a cold pressure bonding member 22 (one pressure bonding member) and a hot pressure bonding member 23 (the other pressure bonding member). The cold pressure bonding member 22 and the hot pressure bonding member 23 constitute a pair of pressure bonding members 21 . The cold pressing member 22 and the hot pressing member 23 are arranged opposite to each other so as to be able to approach or separate from each other.

[0016] The cold pressing member 22 is made of a conductive metal plate. The cold pressing member 22 is fixed to the laminate structure manufacturing equipment SA with its plate surface facing up and down. The cold pressing member 22 has a cushioning material 24 provided on the plate surface facing the hot pressing member 23 .

[0017] The buffer material 24 is made of a flat, conductive elastic material such as conductive silicone rubber. The buffer material 24 is set to have a size slightly larger than the outer diameter of the cathode electrode 14 . The surface of the buffer material 24 that faces the thermocompression member 23 is set as the compression surface (room-temperature-side compression surface 24a). An assembly 25 formed by the buffer material 24 and the cold pressing member 22 constitutes one electrode 31a, which will be described later.

[0018] The thermocompression bonding member 23 is made of a conductive metal plate. The thermocompression member 23 is heated to a set temperature and held there. The thermocompression member 23 is disposed opposite the cold compression member 22 so that the plate surface faces the cold compression member 22 and the member can be moved close to or away from the cold compression member 22 . The thermocompression member 23 has a plate surface facing the coldcompression member 22 set as a compression surface (heating-side compression surface 23a).

[0019] The thermocompression member 23 also constitutes the other electrode 31b, which will be described later. That is, the pair of pressure-bonding members 21 are disposed opposite each other so as to be able to approach and separate from each other. Then, the laminate is placed between the room temperature side pressure bonding surface 24a of the buffer material 24 and the heated side pressure bonding surface 23a of the heated pressure bonding member 23, and the pair of pressure bonding members 21 approach each other to press the laminate into one member, thereby forming the membrane electrode structure 10.

[0020] The short circuit inspection circuit 30 includes a pair of electrodes 31, an inspection power supply 32, a shunt resistor 33, a voltmeter 34, and a determination unit 35. The pair of electrodes 31 is composed of one electrode 31a and the other electrode 31b. The one electrode 31a is composed of an assembly 25 (a cold pressing member 22 and a buffer material 24). The one electrode 31a is electrically connected to the negative electrode of the inspection power supply 32 via one wiring .

[0021] The other electrode 31b is made up of a thermocompression member 23. The other electrode 31 b is electrically connected to the positive electrode of the inspection power supply 32 via the other wiring 37 . The other wiring 37 is provided with a shunt resistor 33 .

[0022] Further, the other wiring 37 is provided with a voltmeter 34 for measuring the voltage drop across the shunt resistor 33 . The determination unit 35 calculates the current value of the current flowing through the shunt resistor 33 from the resistance value of the shunt resistor 33 and the voltage value measured by the voltmeter 34 . The determining unit 35 then determines whether or not there is a short circuit in the membrane electrode assembly 10 based on the calculated current value.

[0023] Next, the operation of the laminated structure manufacturing apparatus SA will be described. First, the thermocompression member 23 is heated to a predetermined temperature and maintained at that temperature while being kept apart from the coldcompression member 22 . Next, each sheet-like member is placed on the cold pressing member 22 to form a laminate. Next, the thermocompression member 23 is lowered onto the coldcompression member 22, and while sandwiching the laminate, it presses the laminate with a predetermined pressure.

[0024] When the laminate is pressed, the thermocompression member 23 heats the laminate, causing the electrodes and the polymer electrolyte membrane 12 to become adhesive and thermoplastic. The adhesive force and pressure then unite the components of the laminate into one body, forming the membrane electrode assembly 10. Furthermore, while the voltage is still applied, the determining unit 35 energizes the short circuit inspection circuit 30 and measures the current flowing through the shunt resistor 33 . Then, the determining unit 35 determines whether or not a short circuit has occurred based on the measured current value. After the determination, the thermocompression member 23 is separated from the membrane electrode assembly 10, whereby the temperature of the membrane electrode assembly 10 drops to room temperature, and the adhesiveness and thermoplasticity subside, and the membrane electrode assembly 10 hardens.

[0025] Next, the effects of this embodiment will be described. In the manufacturing apparatus SA of this embodiment, a buffer material 24 made of conductive silicone rubber having flexibility and conductivity is provided on the plate surface of the cold pressing member 22 facing the hot pressing member 23. The manufacturing equipment SA is configured so that a short circuit test for the membrane electrode assembly 10 can be carried out in conjunction with the process of crimping the laminated bodies together to form the membrane electrode assembly 10. This allows the manufacturing process and inspection process of the membrane electrode assembly 10 to be carried out in one device, thereby realizing a reduction in manufacturing time and manufacturing costs.

[0026] In contrast to this, in the conventional method for manufacturing the membrane electrode assembly 10, the manufacturing equipment and the inspection equipment are configured separately. When the manufacturing equipment and the inspection equipment are provided separately, the entire facility becomes bulky and requires a larger site area, which hinders cost reduction. Furthermore, when the manufacturing equipment and the inspection equipment are provided separately, steps such as winding up the membrane electrode assembly, transporting it, and unrolling the wound membrane electrode assembly are required between the manufacturing process and the inspection process. During these processes, the membrane electrode assembly may become wrinkled or peel off, which can lead to a decrease in quality and yield.

[0027] Furthermore, if the cause of the short circuit is due to a defect in the crimping member or manufacturing equipment, and the manufacturing process and the inspection process are carried out separately, there is a risk that the membrane electrode assemblies will be short-circuited in all lots produced after the defect occurred. In contrast, in the case of detecting short circuits during production as in the present embodiment, the production line can be stopped immediately when a short circuit is found and the cause can be investigated, thereby further suppressing a decrease in yield.

[0028] The manufacturing apparatus SA of this embodiment is configured to press the laminate while heating the thermocompression member 23 to a predetermined temperature, but is not limited to this configuration. For example, in the case of materials that are adhesive at room temperature or materials that adhere to each other, bonding is possible by simply pressing without heating, and the same effects as those of the above-mentioned embodiment can be obtained.

[0029] In this embodiment, one of the pair of electrodes is set as the anode 13 and the other electrode is set as the cathode, but the present invention is not limited to this configuration. For example, one of the electrodes may be a cathode and the other an anode, and the same effects can be obtained.

[0030] Furthermore, in the laminated structure manufacturing apparatus SA of this embodiment, the membrane electrode assembly 10 is exemplified as the laminated structure, but the laminated structure is not limited to this. The present invention can be applied to any process in which a laminate of sheet-like members is laminated, pressed together to form a single member, and processed into a laminate structure, and similar effects can be obtained.

[0031] Furthermore, in the laminate structure manufacturing apparatus SA of this embodiment, the thermocompression bonding member 23 is configured to be movable, but the present invention is not limited to this configuration. For example, it is possible to configure the thermocompression member 23 to be fixed and the cold compression member 22 to be movable, and similar effects can be obtained.

[0032] In addition, in the manufacturing apparatus SA of this embodiment, the buffer material 24 is made of conductive silicone rubber. With this configuration, even if the surface of the buffer material 24 cracks due to aging, sufficient conductivity can be ensured. This allows the intervals between replacement and maintenance of the buffer material 24 to be extended, further reducing manufacturing costs.

[0033] In the manufacturing apparatus SA of this embodiment, the buffer material 24 is made of conductive silicone rubber, but the present invention is not limited to this. For example, it is possible to attach a metal foil to the surface of the rubber material and use the metal foil as an electrode, thereby obtaining the same effect.

[0034] In the manufacturing apparatus SA of this embodiment, the short circuit inspection circuit 30 includes a determination unit . With this configuration, it is possible to determine whether or not a short circuit has occurred in accordance with the electrical characteristics of the membrane electrode assembly. For example, if the membrane electrode assembly 10 has dielectric properties, even if there is no short circuit, a current will temporarily flow through the short circuit inspection circuit 30 immediately after energization, and the current will decrease over time. By providing the determination unit 35, such transient response characteristics can be taken into consideration, and therefore, correct determination can be made.

[0035] Next, the first modified example will be described in detail with reference to FIG. The manufacturing apparatus SB of this modified example differs from the above-described embodiment in that a buffer material (heating-side buffer material 26) is also provided on the heat-pressure bonding member 23 constituting the pressure bonding means 20B. With this configuration, when pressure is applied, the pressure can be applied more gently to the laminate. This makes it possible to further suppress the occurrence of wrinkles, tears, and the like during compression bonding. This modified example is suitable for cases where the set temperature of the thermocompression bonding member 23 is closer to room temperature, where heating is not required during bonding, and where thermal degradation of the buffer material 24 is small.

[0036] Next, the second modified example will be described in detail with reference to FIGS. The manufacturing apparatus SC of this modified example differs from the above-described embodiment in that the heating side pressure bonding surface 23a of the thermocompression member 23 constituting the pressure bonding means 20C is electrically divided into a plurality of regions 23b in a matrix pattern. With this configuration, it is possible to detect the presence or absence of a short circuit for each region 23b, and when a short circuit is confirmed in the membrane electrode assembly 10, it is possible to identify the location of the short circuit. This makes it possible to quickly identify the location of the defect if the short circuit is caused by a defect in the crimping member.

[0037] In this modification, the insulation between the electrodes is ensured by providing gaps between the matrix-shaped regions 23b, but the present invention is not limited to this form. For example, it is possible to interpose an insulator between the matrix-shaped electrodes and to make the heating-side pressure-bonding surface 23a of the thermocompression bonding member 23 a flat surface. By adopting such a configuration, it is possible to further suppress wrinkles, breakage, and the like that occur during pressure bonding.

[0038] In addition, in this modified example, the heating-side pressure-bonding surface 23a is divided into a matrix, but the present invention is not limited to this configuration. For example, it is possible to leave the heated side pressure-bonding surface 23a undivided, but to divide the room temperature side pressure-bonding surface 24a of the cushioning material 24 into a matrix, and to detect short circuits in each area, thereby achieving the same effect.

[0039] Next, the third modified example will be described in detail with reference to FIG. The manufacturing apparatus SC of this modified example differs from the above-described embodiment in that the pressure bonding means 20D is composed of a roller 41. That is, the cold pressing member is composed of the cold roller 42, and the hot pressing member is composed of the hot roller 43. A buffer material 44 is wrapped around the outer circumferential surface of the room temperature roller 42. The buffer material 44 is made of a conductive elastic material such as conductive silicone rubber.

[0040] With this configuration, the short circuit inspection is performed in a linear area, so that when a short circuit is confirmed in the membrane electrode assembly 10, the location of the short circuit can be easily identified. This makes it possible to quickly identify the location of the defect if the short circuit is caused by a defect in the crimping member. Furthermore, by using the rollers 41 for heating and pressure bonding, the heat applied to the membrane electrode assembly 10 is reduced, so that thermal deterioration of the buffer material 24 can be suppressed. [Explanation of symbols]

[0041] SA, SB, SC, SD laminated structure manufacturing equipment 11 Sheet-like member (frame member) 12 Sheet-shaped member (polymer electrolyte membrane) 13 Sheet-shaped member (anode side electrode) 14 Sheet-shaped member (cathode electrode) 21 Pair of crimping members 20A Crimping Method 22 One of the crimping members (cold crimping member) 23 Other crimping member (heat crimping member) 23b area 24 Cushioning material 30 Short circuit test circuit 35 Judgment section

Claims

1. a pair of crimping members arranged opposite to each other; a flexible and conductive buffer material provided on at least one of the pair of pressure-bonding members at a portion facing the other pressure-bonding member; Equipped with a pressure-bonding means for sandwiching and pressing the stacked sheet-like members between one pressure-bonding member and the other pressure-bonding member to form a laminated structure; a short circuit inspection circuit that detects the presence or absence of a short circuit in the laminated structure during the process in which the crimping means crimps the plurality of sheet-like members together to form the laminated structure; Equipped with A manufacturing apparatus for a laminated structure.

2. The laminated structure manufacturing apparatus according to claim 1, The buffer material is Made of conductive silicone rubber A manufacturing apparatus for a laminated structure.

3. The laminated structure manufacturing apparatus according to claim 1, The short circuit inspection circuit includes: A determination unit is provided to determine whether or not a short circuit has occurred in the laminated structure. A manufacturing apparatus for a laminated structure.

4. The laminated structure manufacturing apparatus according to claim 1, The at least another crimping member, Electrically divided into multiple regions, The short circuit inspection circuit includes: Check each area for short circuits A manufacturing apparatus for a laminated structure.

5. a crimping step of sandwiching and pressing the laminated structure between a pair of crimping members to crimp the laminated structure together; an inspection step of detecting a current flowing through the laminated structure while maintaining the clamping and pressing of the laminated structure after the laminated structure has been crimped together to determine whether or not there is a short circuit; Equipped with A method for manufacturing a laminated structure comprising:

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