Adhesive application system

Abstract

The present invention addresses the problem of making it difficult for an adhesive to overflow from a desired coating region when a gas diffusion layer is bonded to an intermediate layer in the manufacturing stage of a fuel cell. In order to solve the problem, the present invention provides an adhesive application system in which an adhesive is applied to an intermediate layer in a manufacturing stage of a fuel cell provided with the intermediate layer and gas diffusion layers on both sides thereof. The adhesive application system includes an application unit, a robot arm, and a control device. The coating part coats an adhesive when the valve is opened. The robot arm is configured so as to be capable of moving the coating unit. The control device controls the valve and the mechanical arm. The control device applies the adhesive to the intermediate layer in a linear shape from a coating start point by opening the valve before the coating part is located directly above the coating start point while moving the coating part by the robot arm.

Description

Technical Field

[0001] The present invention relates to a system for applying an adhesive to components constituting a fuel cell. Background Art

[0002] In a fuel cell, some fuel cells include, in order from one side thereof, a gas diffusion layer on the anode side, an intermediate layer, and a gas diffusion layer on the cathode side. When this fuel cell supplies a fuel gas containing hydrogen as a gas to the gas diffusion layer on the anode side and supplies an oxidizing gas containing oxygen as a gas to the gas diffusion layer on the cathode side, power generation is performed.

[0003] [Prior Art Documents]

[0004] (Patent Documents)

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2023-161181 Summary of the Invention

[0006] [Problems to be Solved by the Invention]

[0007] The present inventors have noticed the following problems in the manufacturing stage of such a fuel cell. In a fuel cell, sometimes, structurally, one gas diffusion layer can be joined to the intermediate layer by hot pressing, while the other gas diffusion layer cannot be joined to the intermediate layer by hot pressing. In this case, it is necessary to bond the other gas diffusion layer to the intermediate layer using an adhesive.

[0008] Specifically, for example, an adhesive is applied linearly to the intermediate layer, and the gas diffusion layer is bonded to the intermediate layer. However, both sides of the region where the adhesive is applied linearly sometimes become adhesive prohibited regions. In addition, as the adhesive prohibited regions mentioned here, for example, the electrode region and the vicinity of the sealing region in the fuel cell can be cited.

[0009] Specifically, for example, when the adhesive overflows into the electrode region, it may have an adverse effect on the internal resistance of the fuel cell and the like. In addition, for example, when it overflows into the vicinity of the sealing region, it may have an adverse effect on the sealing performance in the fuel cell.

[0010] In summary, it is necessary to precisely control the region where the adhesive is applied.

[0011] The present invention has been made in view of the above circumstances, and an object thereof is to prevent the adhesive from overflowing from a desired application region when bonding a gas diffusion layer to an intermediate layer in the manufacturing stage of a fuel cell.

[0012] [Technical Means for Solving the Problem]

[0013] The inventor of the present invention has found that the above object can be achieved by performing specified control on the valve of the coating section for coating the adhesive and the robotic arm that moves the coating section, thereby completing the present invention. The present invention is the following adhesive coating systems (1) to (4).

[0014] (1) An adhesive coating system that coats an adhesive on the intermediate layer during the manufacturing stage of a fuel cell having an intermediate layer and gas diffusion layers on both sides thereof, and the adhesive coating system includes:

[0015] A coating section that coats the above-mentioned adhesive when the valve is opened;

[0016] A robotic arm configured to be able to move the above-mentioned coating section; and,

[0017] A control device that controls the above-mentioned valve and the above-mentioned robotic arm; and,

[0018] The above-mentioned control device opens the above-mentioned valve before the coating section is directly above the coating start point while moving the coating section with the above-mentioned robotic arm, and coats the above-mentioned intermediate layer with the above-mentioned adhesive in a line shape starting from the above-mentioned coating start point.

[0019] According to this configuration, the valve is opened before the coating section is directly above the coating start point while moving the coating section. Therefore, compared with the case where the coating section stops directly above the coating start point and then the valve is opened, and after starting to coat the adhesive, the coating section moves in a line shape, it is less likely to have liquid accumulation at the coating start point. Thus, when the gas diffusion layer is bonded to the intermediate layer, it is less likely for the adhesive to overflow from the desired coating area.

[0020] (2) The adhesive coating system according to the above-mentioned (1), wherein the above-mentioned control device coats the above-mentioned intermediate layer with the above-mentioned adhesive in a dotted line shape as the intermittent above-mentioned line shape by intermittently opening the above-mentioned valve.

[0021] In the case of coating the adhesive in a solid line shape, there is a limit to the narrowing of the coating width. In this regard, according to this configuration, by coating the intermediate layer with the adhesive in a dotted line shape, it is easy to suppress the coating width of the adhesive. Thus, when the gas diffusion layer is bonded to the intermediate layer, it is also less likely for the adhesive to overflow from the desired coating area.

[0022] (3) An adhesive coating system that coats an adhesive on the intermediate layer during the manufacturing stage of a fuel cell having an intermediate layer and gas diffusion layers on both sides thereof, and the adhesive coating system includes:

[0023] A coating section that coats the above-mentioned adhesive when the valve is opened;

[0024] A robotic arm configured to be able to move the aforementioned coating unit; and,

[0025] A control device that controls the aforementioned valve and the aforementioned robotic arm; and,

[0026] The aforementioned control device applies the adhesive to the aforementioned intermediate layer in a dotted line pattern by moving the aforementioned coating unit using the aforementioned robotic arm and intermittently opening the aforementioned valve.

[0027] According to this configuration, similar to the case of the aforementioned (2), it is also easy to suppress the coating width of the adhesive. Therefore, when bonding the gas diffusion layer to the intermediate layer, the adhesive can be prevented from overflowing from the desired coating area.

[0028] (4) The adhesive coating system according to any one of the aforementioned (1) to (3), wherein the aforementioned intermediate layer includes an electrolyte membrane and a resin film provided around the aforementioned electrolyte membrane.

[0029] The aforementioned adhesive is a moisture-curing adhesive.

[0030] The aforementioned control device applies the aforementioned adhesive to the aforementioned resin film.

[0031] The resin film is not easily absorbent of moisture. In contrast, the gas diffusion layer is easily absorbent of moisture. Therefore, in this configuration, at the time of applying the moisture-curing adhesive to the resin film, the adhesive is not easily cured. Subsequently, at the time of bringing the gas diffusion layer into contact with the adhesive, the moisture in the gas diffusion layer causes the adhesive to be easily cured. Thus, it is easy to properly bond the gas diffusion layer to the intermediate layer. Therefore, it is easy to suppress the total amount of the adhesive to be applied and easy to suppress the coating width of the adhesive. Therefore, when bonding the gas diffusion layer to the intermediate layer, the adhesive can also be prevented from overflowing from the desired coating area.

[0032] (Advantages of the Invention)

[0033] As described above, according to the configuration of the aforementioned (1) or (3), when bonding the gas diffusion layer to the intermediate layer during the manufacturing stage of the fuel cell, the adhesive can be prevented from overflowing from the desired coating area. Furthermore, according to the configurations of the aforementioned (2) and (4) that cite the aforementioned (1) or (3), respective additional advantages can be obtained. Description of the Drawings

[0034] Figure 1 is a schematic diagram showing the adhesive coating system of the first embodiment.

[0035] Figure 2 is a plan view showing the adhesive of the comparative method.

[0036] Figure 3It is a diagram showing the process of applying the adhesive in a solid line pattern.

[0037] Figure 4 It is a side sectional view showing the internal structure of the fuel cell, specifically showing Figure 6 the cross-section of the fg4-fg4 line.

[0038] Figure 5 It is a plan view showing the state where the adhesive is applied in a solid line pattern to the intermediate layer of the fuel cell.

[0039] Figure 6 It is a plan view showing the state where the gas diffusion layer is attached to the intermediate layer of the fuel cell.

[0040] Figure 7 It is a diagram showing the process of applying the adhesive in a dotted line pattern in the second embodiment. Detailed implementation mode

[0041] Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited by any of the following embodiments and can be appropriately modified and implemented within the scope without departing from the gist of the present invention.

[0042] [First Embodiment]

[0043] Figure 1 The adhesive coating system 50 shown is a device for manufacturing Figure 4 the fuel cell 40 shown. The fuel cell 40 sequentially includes a gas diffusion layer 20a on the anode side, an intermediate layer 30, and a gas diffusion layer 20c on the cathode side from one side thereof. In addition, the intermediate layer 30 may also be referred to as "UEA" or "unitized electrode assembly".

[0044] The intermediate layer 30 includes a resin film 32 and an electrolyte film 35. The resin film 32 is a film for protecting the edge portion of the electrolyte film 35 and is provided around the electrolyte film 35. Specifically, the resin film 32 is composed of, for example, the following two films: a first resin film closer to the anode side than the electrolyte film 35; and a second resin film closer to the cathode side than the electrolyte film 35. On this resin film 32, as Figure 5 shown, a film window 32w is formed for exposing a portion of the electrolyte film 35 other than the edge portion.

[0045] As Figure 4 shown, each gas diffusion layer 20a, 20c includes a carbon paper 23 and a porous layer 26. The porous layer 26 is provided on the side closer to the intermediate layer 30 than the carbon paper 23.

[0046] As Figure 6As shown, the intermediate layer 30 is larger in plan view than the gas diffusion layers 20a and 20c. Therefore, as Figure 4 shown, the end portions of the intermediate layer 30 protrude from between the gas diffusion layers 20a and 20c. The gas diffusion layer 20a on the anode side is attached to the intermediate layer 30 by thermocompression. On the other hand, the gas diffusion layer 20c on the cathode side is attached to the intermediate layer 30 by an adhesive A.

[0047] Hereinafter, a gas containing hydrogen will be referred to as a "fuel gas", and a gas containing oxygen will be referred to as an "oxidizing gas". When the fuel cell 40 shown in Figure 4 is in use, the electrodes on both sides of the intermediate layer 30, that is, the anode-side electrode and the cathode-side electrode, are electrically connected via a circuit including the power supply object. When in this state, a fuel gas is supplied to the gas diffusion layer 20a on the anode side, and an oxidizing gas is supplied to the gas diffusion layer 20c on the cathode side, power generation occurs.

[0048] Figure 1 The adhesive coating system 50 shown in Figure 4 is a system for coating the adhesive A on the cathode-side surface of the intermediate layer 30 at the manufacturing stage of the fuel cell 40 shown above. Specifically, as shown in Figure 5 , the adhesive A is coated in a solid line shape along the film window 32w on both side portions of the resin film 32 sandwiching the film window 32w.

[0049] As shown in Figure 1 , the adhesive coating system 50 includes a coating unit 51, a pressurizing system 52, a robotic arm 53, and a control device 55.

[0050] The coating unit 51 is a dispenser nozzle or the like and contains the adhesive A inside. The adhesive A is a moisture-curing adhesive. The pressurizing system 52 is an air pressurization control method or the like and is configured to be able to supply back pressure to the adhesive A inside the coating unit 51. A valve 51b is provided between the pressurizing system 52 and the coating unit 51. When the valve 51b is opened, the adhesive A is coated from the coating unit 51 by the back pressure from the pressurizing system 52.

[0051] The robotic arm 53 is configured to be able to move the coating unit 51. The control device 55 controls the pressurizing system 52, the valve 51b, and the robotic arm 53.

[0052] Next, the problems to be solved in the present embodiment will be described. Hereinafter, by Figure 1The control device 55 shown assumes the following control situation as the "comparison method". In the comparison method, after the coating unit 51 stops directly above the specified coating start point Sp, the valve 51b is opened, and after starting to coat the adhesive A, the coating unit 51 is moved linearly. In this case, sometimes due to the delay in the departure of the coating unit 51 from the coating start point Sp, as Figure 2 shown, a liquid accumulation Ap appears at the coating start point Sp.

[0053] In this regard, Figure 1 the control device 55 of the present embodiment shown uses the robotic arm 53 to move the Figure 3 shown coating unit 51, and while moving the coating unit 51, the valve 51b is opened before the coating unit 51 is directly above the coating start point Sp. Thus, the adhesive A is coated in a solid line shape starting from the coating start point Sp. In addition, regarding the timing of opening the valve 51b at this time, it is controlled based on the viscosity of the adhesive A, the magnitude of the back pressure, and the moving speed of the coating unit 51 to be the timing when the adhesive A is coated on the resin film 32 from the coating start point Sp. After that, the control device 55 closes the valve 51b at a specified time, and thus the coating of the adhesive A is completed.

[0054] By performing the above actions twice by changing the part where the adhesive A is coated, as Figure 5 shown, on both sides of the resin film 32 sandwiching the film window 32w, the adhesive A is coated in a solid line shape along the film window 32w. This resin film 32 is not easily absorbent of moisture. Therefore, the moisture-curing adhesive A coated on the upper surface of this resin film 32 is not easily cured. In addition, the manufacturing environment at this time is about 50% RH (23 °C).

[0055] After that, on the intermediate layer 30, the Figure 6 shown cathode-side gas diffusion layer 20c is placed. Specifically, at this time, Figure 4 the shown porous layer 26 abuts against the adhesive A. The porous layer 26 is easily absorbent of moisture, so it contains sufficient moisture at this moment. The moisture in the porous layer 26 makes the adhesive A easily cured.

[0056] Hereinafter, the structure and effects of the present embodiment will be summarized. Hereinafter, the cathode-side gas diffusion layer 20c will be simply referred to as the "gas diffusion layer 20c".

[0057] According to the present embodiment, as Figure 3 shown, while moving the coating unit 51, the valve 51b is opened before the coating unit 51 is directly above the coating start point Sp. Therefore, compared with the case where the coating unit 51 stops directly above the coating start point Sp and then the valve 51b is opened, and after starting to coat the adhesive A, the coating unit 51 is moved linearly, that is,Figure 2 The comparison method shown, such as Figure 3 shown, can prevent the accumulation of liquid Ap at the coating start point Sp. Therefore, when Figure 5 the intermediate layer 30 shown is bonded to Figure 6 the gas diffusion layer 20c on the cathode side shown, the adhesive A is less likely to overflow from the desired coating area. Therefore, it is possible to suppress the overflow of the adhesive A into the adhesive prohibited area in the fuel cell 40.

[0058] Specifically, as the adhesive prohibited area mentioned here, for example, it can be listed as Figure 4 near the electrode area and the sealing area in the fuel cell 40 shown. The electrode area is the area on both sides of the electrolyte membrane 35 sandwiching the electrolyte membrane 35 in the thickness direction. On the other hand, the sealing area is the joint area between a plurality of cover members (not shown) covering the intermediate layer 30 and the gas diffusion layers 20a, 20c. Therefore, the area near the sealing area is near the part protruding from between the gas diffusion layers 20a, 20c in the intermediate layer 30. Therefore, when applying the adhesive A, the electrode area and the area near the sealing area are located on both sides of the coating area in the horizontal direction.

[0059] In summary, according to the present embodiment, by making it difficult for the liquid accumulation Ap to occur, it is possible to suppress the overflow of the adhesive A into the electrode area and the area near the sealing area located on both sides thereof. Therefore, it is possible to suppress the drawbacks such as the overflow of the adhesive A into the electrode area and having an adverse effect on the internal resistance of the fuel cell 40, and the overflow into the area near the sealing area and having an adverse effect on the sealing performance in the fuel cell 40.

[0060] In addition, since it is possible to make it difficult for the liquid accumulation Ap to occur in this way, it is also possible to suppress Figure 6 the deviation in the penetration amount of the adhesive A coated in a solid line shape as shown in the parts of the gas diffusion layer 20c. Therefore, it is also possible to suppress the deviation in elasticity at each part of the gas diffusion layer 20c.

[0061] Furthermore, Figure 5 the adhesive A shown is a moisture-curing type adhesive A. As described above, the resin film 32 is not easily absorbent of moisture, while the porous layer 26 of the gas diffusion layer 20c is easily absorbent of moisture. Therefore, as Figure 5 shown, at the time of applying the moisture-curing type adhesive A to the resin film 32, the adhesive A is not easily cured. After that, as Figure 6 shown, at the time of bringing the gas diffusion layer 20c into contact with the adhesive A, the moisture in the gas diffusion layer 20c makes the adhesive A easily cured. Thus, it is easy to properly bond the gas diffusion layer 20c to the intermediate layer 30. Therefore, it is easy to suppress Figure 5The total amount of the adhesive A shown, and it is easy to suppress the coating width W of the adhesive A. Therefore, when bonding the Figure 6 shown gas diffusion layer 20c to the intermediate layer 30, the adhesive A can also be prevented from overflowing from the desired coating area.

[0062] [Second Embodiment]

[0063] Next, the second embodiment will be described. Regarding this embodiment, based on the first embodiment, the description will be centered on the aspects different from it, and the description of the aspects the same as or similar to the first embodiment will be omitted as appropriate.

[0064] In this embodiment, Figure 1 the shown control device 55 intermittently opens the valve 51b while moving the coating unit 51 with the robotic arm 53. Thus, as Figure 7 shown, a back pressure from the pressurizing system 52 is intermittently applied to the adhesive A in the coating unit 51. Thus, the adhesive A is applied to the resin film 32 in a dotted line shape.

[0065] According to this embodiment, the following effects can be obtained. As Figure 5 shown, when the adhesive A is applied in a solid line shape, the reduction of the coating width W is limited. In this regard, according to this embodiment, by intermittently opening the valve 51b, as Figure 7 shown, the adhesive A is applied in a dotted line shape. Thus, it is easy to suppress the coating width W of the adhesive A. Therefore, when bonding the gas diffusion layer 20c to the intermediate layer 30, the adhesive A can also be prevented from overflowing from the desired coating area.

[0066] [Other Embodiments]

[0067] The embodiments shown above can be modified as follows, for example. In the Figure 7 shown second embodiment, the valve 51b can also be opened after temporarily stopping the movement of the robotic arm 53 to the coating unit 51. In this case, by applying the adhesive A in a dotted line shape, the effect of being more likely to suppress the coating width W than in the case of applying it in a solid line shape can also be obtained.

[0068] Reference Numerals

[0069] 20c Gas diffusion layer on the cathode side

[0070] 30 Intermediate layer

[0071] 32 Resin film

[0072] 35 Electrolyte membrane

[0073] 40 Fuel cell

[0074] 50 Adhesive Coating System

[0075] 51 Coating Section

[0076] 51b Valve

[0077] 53 Robot Arm

[0078] 55 Control Device

[0079] A Adhesive

[0080] Sp Coating Start Point

Claims

1. An adhesive coating system that coats an adhesive on the intermediate layer during the manufacturing stage of a fuel cell having an intermediate layer and gas diffusion layers on both sides thereof, and the adhesive coating system includes: A coating unit that coats the adhesive when the valve is opened; A robotic arm configured to be able to move the coating unit; and, A control device that controls the valve and the robotic arm; and, The control device opens the valve before the coating unit is directly above the coating start point while moving the coating unit with the robotic arm, and coats the intermediate layer with the adhesive linearly from the coating start point.

2. The adhesive coating system according to claim 1, wherein, The control device coats the intermediate layer with the adhesive in a dotted line shape, which is a discontinuous line, by intermittently opening the valve.

3. An adhesive coating system that coats an adhesive on the intermediate layer during the manufacturing stage of a fuel cell having an intermediate layer and gas diffusion layers on both sides thereof, and the adhesive coating system includes: A coating unit that coats the adhesive when the valve is opened; A robotic arm configured to be able to move the coating unit; and, A control device that controls the valve and the robotic arm; and, The control device coats the intermediate layer with the adhesive in a dotted line shape by moving the coating unit with the robotic arm and intermittently opening the valve.

4. The adhesive coating system according to any one of claims 1 to 3, wherein, The intermediate layer includes an electrolyte membrane and a resin film provided around the electrolyte membrane. The adhesive is a moisture-curing adhesive. The control device coats the adhesive on the resin film.

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