Sealing and glue spraying device for fuel cell polar plate

Abstract

The utility model discloses a fuel cell polar plate sealing glue spraying device which comprises an operation table, a polar plate fixing area is arranged on the operation table, the operation table comprises a fixing table and an air pipe, negative pressure is formed on the surface of the fixing table through air exhaust of the air pipe, and therefore the polar plate is attached and fixed. The moving assembly comprises an X-axis sliding rail and a Y-axis sliding rail and is used for enabling the spraying assembly and the light curing machine to move to any point in the plane above the pole plate fixing area; and the injection assembly comprises an injection valve and an injection needle opening below the injection valve. The polar plate gluing device is flexible to operate and can be used for gluing operation of various different polar plates.

Description

Technical Field

[0001] The utility model belongs to a glue spraying device, in particular to a sealing glue spraying device for a fuel cell. Background Art

[0002] Currently, the main sealing processes for fuel cell plates are screen printing, transfer printing, dispensing, injection molding, etc.

[0003] Screen printing technology is widely used in bipolar plates. It mainly uses a scraper to leak ink through the screen onto the substrate, forming ink marks as the main body of the print, and then drying to make the glue layer sticky. However, the speed is slow, the efficiency is low, the dot restoration is poor, and the blockage of the screen holes easily causes defects such as glue leakage and difficulty in cleaning. In order to ensure the effect of sealing printing, screen printing technology requires the surface of the plate to be relatively flat. For uneven or complex planes on the surface of the plate, screen printing technology cannot guarantee the quality of the seal.

[0004] Transfer technology is similar to movable type printing. Its limitation is that the transferred images and texts are easily deformed. This is related to the shape of the product and the properties of the water transfer film itself. At the same time, because the tooling used is more complicated and the cost is higher, the more complicated the process, the higher the price.

[0005] Glue dispensing and injection molding are currently widely used in fuel cells. The glue dispensing process uses equipment to dispense glue on the surface of the workpiece according to the circuit, and then the glue layer is adhered to the surface through drying. However, the molded glue layer is thicker, generally greater than 100μm, which is not conducive to improving the volume power density of the battery stack. In addition, the glue dispensing process has some defects in joint processing, which can easily form artificial stacking height. When hundreds of plates are stacked, the stacking point exceeds the tolerance too much, causing the plate to deform or even rupture, and finally the seal fails.

[0006] The injection molding process mainly uses a mold to shape the glue layer, that is, the glue line, and then transfers it to the plate or the membrane electrode frame. However, the glue layer is thick and not easy to iterate and update. The mold and sample need to be remade, which greatly increases the R&D cycle. The injection molding process has low flexibility in operation changes. The rapid iteration and continuous updating of products directly affect the production of plastic films, which has the problem of long cycle and high investment cost.

[0007] In metal plate fuel cell stacks, the anode and cathode plates are mainly welded and injected to meet the sealing requirements of the single cell. The welding process has high cost and precision requirements. During the welding process, welding slag and some undesirable gases must be prevented from penetrating, which will cause some uncertain factors on the surface layer of the plate. The injection molding process has low flexibility in operation changes. The rapid iteration and continuous updating of products directly affect the production of plastic films, resulting in long cycles and high investment costs. Summary of the invention

[0008] Purpose of the utility model: The utility model aims to provide a fuel cell plate sealing glue spraying device, which has a plate fixing area for fuel cell adsorption, and can realize automatic and batch glue spraying operations for fuel cell plates, and is particularly suitable for sealing metal plates with corrugated or large uneven surfaces.

[0009] In order to achieve the above-mentioned utility model purpose, the following technical solution is provided.

[0010] A fuel cell plate sealing glue spraying device comprises an operating table, wherein the operating table is provided with:

[0011] The plate fixing area is provided with a fixing platform and an air pipe for forming negative pressure on the surface of the fixing platform;

[0012] The moving assembly includes an X-axis slide rail and a Y-axis slide rail, which are used to enable the injection assembly and the light curing machine to move to any point in the upper plane of the plate fixing area;

[0013] The injection assembly includes an injection valve and an injection needle port thereunder.

[0014] Furthermore, in the above scheme, the surface of the fixing table is provided with suction holes, which are connected to the air cavity inside the fixing table. The air cavity is connected to the suction device through an air pipe to form suction on the surface of the fixing table, thereby achieving adsorption and fixation of the electrode plate.

[0015] Furthermore, the X-axis slide rail and the Y-axis slide rail may be configured as pneumatic, electric or mechanical drive mechanisms;

[0016] The pneumatic type is connected to the cylinder to realize the movement of the injection assembly and the light curing machine;

[0017] The electric type means that there is a motor to realize the movement of the injection assembly and the light curing machine;

[0018] The mechanical method refers to the use of a ball screw module to achieve the movement of the injection assembly and the light curing machine.

[0019] Furthermore, the injection valve includes a piezoelectric injection valve or a pneumatic injection valve.

[0020] Furthermore, the fixing platform can be replaced according to different sizes of the pole plates, including being configured to have an exterior and surface shape that matches the pole plates, including being configured to have a surface curve including an arched shape and a wavy shape.

[0021] Furthermore, the mechanical driving method includes setting up a ball screw module, and driving the injection valve and the light curing machine to be fixed by a screw slider in the screw module.

[0022] Furthermore, the device includes a protective cover.

[0023] Furthermore, in the above solution, the control unit of the device includes a PLC controller or a host computer.

[0024] In addition, the device includes setting the injection assembly and / or light curing machine to be fixed, setting the plate fixing area and its fixing platform to be movable, and moving the fuel cell plate on the fixing platform to the injection assembly and light curing machine to complete the gluing operation through the movable assembly.

[0025] Beneficial effects: Compared with the prior art, the device described in the utility model adopts negative pressure adsorption to fix the fuel cell plate, which can ensure that the surface of the plate to be glued is not blocked, and at the same time, the plate can be flat, thereby improving the glue dispensing quality. The utility model also adopts a mobile component to realize the movement of the injection component and the light curing machine at any point in the plane, and its control and operation are more flexible. It is further pointed out that the glue layer is ultra-thin, the utility model is uniform and controllable, and the thickness is adjustable for easy operation. In particular, the glue layer path can be switched at any time during research and development or production, with high production efficiency, and the spraying can be transmitted by multi-plate guide rails; glue coating, transmission, and curing are integrated, saving manpower operation; the degree of consistency is high, and the error is ±5μm. Finally, the metal bipolar plate is sealed using a new jet-type process. The thickness of the sealing layer of the new process is thinner, thereby reducing the stacking height of the battery stack; and the defects of the combination point and welding point of the general glue dispensing and welding process are solved; this process modifies the existing equipment, automates the glue spraying and curing into an integrated one, and increases the production line efficiency by more than several times. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the device described in the utility model;

[0027] Figure 2 It is a schematic diagram of the arrangement structure of the ventilation holes on the upper surface of the fixed table;

[0028] Figure 3 It is a structural schematic diagram of a fuel cell plate;

[0029] Figure 4 It is a combined structure of fuel cell plates achieved by gluing. DETAILED DESCRIPTION

[0030] The utility model provides a fuel cell plate sealing spray device, which is used to achieve the gluing and sealing of the fuel cell plate, forming a uniform and extremely thin sealing layer with a thickness of 20-100 μm on the surface of the plate with complex and uneven surface, reducing the core thickness of the stack and increasing the volume power. Compared with screen printing technology. Spraying glue is suitable for more complex plate surfaces, and has better results for sealing points on complex surfaces; compared with dispensing technology, the advantage of spraying glue is that the design thickness of the glue layer can be below 100 μm, generally around 20-100 μm. This is impossible to achieve with dispensing technology.

[0031] In addition, when the plate design has uneven features and the thickness of the sealing ring is required to be very thin, the existing printing technology cannot meet the requirements. Although dispensing can be applied to uneven plates, it cannot meet the thickness of the sealing ring of tens of microns. Therefore, the glue spraying solution can be applied to the uneven plate features and make the thickness of the sealing ring very thin. This is an innovation that needs to be emphasized. The design of the glue sprayer and the fixture is to achieve this innovation. Specifically, the glue spraying device provided by the utility model is as follows.

[0032] like Figure 1 As shown, a fuel cell plate sealing glue spraying device is provided with an operating table 1. Based on the operating table 1, a plate fixing area is provided in the middle thereof, and the plate fixing area can be provided with a fixing table 2, including a convex or concave setting. Figure 2 As shown, the hollow structure of the fixing platform 2 is an air cavity, which is connected to the air vents on the surface of the fixing platform 2 (the position where the plate is placed), and the air cavity is connected to an air pipe 201. The air pipe 201 is used to connect to air extraction equipment such as an air pump, especially to form a negative pressure in the air cavity, so that air enters the air vents on the surface of the fixing platform 2. After the fuel cell plate is placed, there will be an adsorption force, thereby fixing the plate for a long time.

[0033] The operating table 1 is provided with a movable component, which can be arranged along the side panel of the operating table 1, including an X-axis slide rail 101 and a Y-axis slide rail 102. A movable slider can be arranged on the slide rail to install the injection valve 3 and the injection needle port 301 located at the bottom thereof. The injection needle port 301 is replaceable to realize glue coating operations of different thicknesses, and can also be selected according to different colloid materials.

[0034] For the moving components, the existing technology can also be combined, such as a ball screw module, an electric telescopic device or a pneumatic telescopic device, to drive the corresponding position of the slider. The X-axis slide rail 101 and the Y-axis slide rail 102 can be set on the side plate of the operating table 1. Figure 1 As shown. The X-axis slide rail 101 can be set on the Y-axis slide rail 102, and then the injection valve 3 can be slidably set on the X-axis slide rail 101. For the movement of the injection valve 3 to achieve dispensing, first the control unit (control switch 6) controls it to move a corresponding distance on the X-axis slide rail, and then the entire X-axis slide rail 101 can be controlled to move on the Y-axis slide rail 102 to achieve the distance traveled in the Y-axis direction in the plane. For the plate, combined with Figure 3 and Figure 4 As shown, its motion trajectory is a regular geometric figure, that is, the control and the like are routine operations that should be performed by those skilled in the art.

[0035] To further illustrate, the Brookfield viscosity of suitable glue is generally between 300 and 100,000 cps, mainly including UV glue, UV spray adhesive, epoxy resin, pressure-sensitive adhesive, hot melt adhesive, etc.

[0036] The spraying environment temperature is 25℃±5, and the nozzle temperature is normally between 20-80℃.

[0037] The curing method depends on the characteristics of the glue. For example, UV glue is cured by ultraviolet light; epoxy resin is cured by adding ultraviolet sensitizer; pressure-sensitive adhesives are cured by natural evaporation and heating, and hot-melt adhesives are cured by physical cooling.

[0038] The following is an application of the device described in the utility model on the sealing surface of the anode and cathode plates and the membrane electrode, combined with Figure 2 The glue spraying route exists at the inlet and outlet of hydrogen, air and cooling. At the intersection of the lines, the glue is sprayed through the injection valve nozzle to form an intersection. Under the influence of gravity, the glue layer in the intersection area is highly consistent, and there is no accumulation, glue leakage and other undesirable phenomena.

[0039] When the glue is sprayed for the first time, a dense and fine dot structure is formed on the surface of the workpiece being coated. In about 10 seconds (the thicker the glue layer and the greater the amount of glue, the shorter the time), the dots are formed into an integrated thin surface structure, and the concave and convex areas tend to be flat under the action of gravity. The self-leveling time is also subject to the external ambient temperature. The higher the temperature, the faster the leveling speed, and it tends to be absolutely flat infinitely.

[0040] The glue layer on the workpiece cross section Figure 4 , align the glue layer position during bipolar plate bonding, and then pressurize and seal through the upper and lower layers. Taking the 50μm spray height and 2mm width of the monopolar plate as an example, after the single plate is stacked, the pressure is pressurized to 3T. The actual glue layer is compressed to a height of 25-35μm and a width of about 2.5mm. The overall glue layer height is reduced by about 30%-50%, and it has passed the 200Kpa airtightness verification. At the same time, during the verification, the concentration of the glue and the size of the stacking pressure directly affect the final actual stacking height.

[0041] Currently, this invention has been successfully used to verify more than 1,000 plates, and 530 metal stacks have been stacked, and the 200Kpa sealing verification requirements have been met. In the performance test, the height of the MEA needs to be relatively consistent with the height of the glue layer after compression, so that the performance of the battery stack can reach the best level.

[0042] Based on the ultra-thin sealing of the device described in the utility model, the glue spray head is replaced with a piezoelectric valve spray nozzle, and a control valve with stable performance and high precision is made based on the bending deformation principle under the action of voltage. The glue spraying route exists at the inlet and outlet of hydrogen, air, and cooling. At the intersection area of ​​the line, the glue is sprayed through the spray valve nozzle to form an intersection. When the glue is self-leveled under the influence of gravity, the glue layer height in the intersection area is consistent, and there is no undesirable phenomenon such as accumulation and glue leakage. At the same time, the utility model is suitable for the surface of fuel cell plates of different materials, and can be quickly cured. The operation process is simple and reliable and can be used for mass production. The design scheme can also be changed at any time during research and development, and the verification results can be obtained in a short time. It can also be used for spray sealing of irregular surfaces such as graphite plates, metal plates, and composite plates.

Claims

1. A fuel cell plate sealing glue spraying device, comprising an operating table (1), characterized in that: The operating table (1) is provided with: The electrode plate fixing area is provided with a fixing platform (2) and an air pipe for forming negative pressure on the surface of the fixing platform (2); A moving assembly, comprising an X-axis slide rail (101) and a Y-axis slide rail (102), for enabling the injection assembly and the light curing machine (4) to move to any point in the upper plane of the fixed platform (2); The injection assembly comprises an injection valve (3) and an injection needle port (301) below the injection valve.

2. The fuel cell plate sealing glue spraying device according to claim 1, characterized in that: The fixing platform (2) is provided with air extraction holes distributed on its surface, the air extraction holes being connected to the air cavity inside the fixing platform (2), and the air cavity being connected to the air extraction device via the air pipe (201) to form suction force on the surface of the fixing platform (2), thereby achieving adsorption and fixation of the electrode plate.

3. The fuel cell plate sealing glue spraying device according to claim 1, characterized in that: The X-axis slide rail (101) and the Y-axis slide rail (102) may be configured as pneumatic, electric or mechanical drive mechanisms; The pneumatic type is to connect the cylinder to realize the movement of the injection assembly and the light curing machine (4); The electric type means that a motor is present to realize the movement of the injection assembly and the light curing machine (4); The mechanical method refers to the use of a ball screw module to achieve the movement of the injection assembly and the light curing machine (4).

4. The fuel cell plate sealing glue spraying device according to claim 1, characterized in that: The injection valve (3) may be configured as a piezoelectric injection valve or a pneumatic injection valve.

5. The fuel cell plate sealing glue spraying device according to claim 1, characterized in that: The fixing platform (2) can be replaced according to different sizes of the pole plates, including being configured to have an exterior and surface shape that matches the pole plates, including being configured to have a curved surface such as an arch or a wave.

6. The fuel cell plate sealing glue spraying device according to claim 3, characterized in that: The mechanical driving method includes setting a ball screw module, and driving the injection valve (3) and the light curing machine (4) to be fixed by a screw slider in the screw module.

7. The fuel cell plate sealing glue spraying device according to claim 1, characterized in that: The device includes providing a protective cover.

8. The fuel cell plate sealing glue spraying device according to claim 1, characterized in that: The control unit of the device includes a PLC controller or a host computer.

9. The fuel cell plate sealing glue spraying device according to claim 1, characterized in that: The device comprises setting the injection assembly and / or the light curing machine (4) to be fixed, setting the plate fixing area and its fixing platform (2) to be movable, and moving the fuel cell plate on the fixing platform (2) to the injection assembly and the light curing machine (4) to complete the gluing operation by moving the assembly.

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