An air tightness testing apparatus

Abstract

This application provides an airtightness testing device, relating to the field of airtightness testing technology. The device includes: a cover plate and a base plate arranged opposite each other; the cover plate has an air inlet channel with a first connector and an air inlet hole at each end, the air inlet hole being located on the inner side of the cover plate; the base plate has an air outlet channel with a second connector and an air outlet hole at each end, the air outlet hole being located on the inner side of the base plate; a sealing pad with a hollowed-out area matching the workpiece to be tested; an inflation device and an air detection device; during measurement, the workpiece to be tested is clamped between the cover plate and the base plate in a closed state, with the sealing pad placed on the side of the workpiece facing the base plate. By adjusting the position of the sealing pad and the shape of the hollowed-out area, airtightness testing of bipolar plates of different specifications can be achieved, offering strong applicability, simple and quick operation, and low operating costs.

Description

Technical Field

[0001] This application relates to the field of airtightness testing technology, and in particular to an airtightness testing device for a fuel cell bipolar plate. Background Technology

[0002] Bipolar plates are a key component of fuel cell stacks, and their airtightness is related to the safety of the entire battery. Therefore, all bipolar plates must undergo airtightness testing before leaving the factory to ensure that the products are qualified.

[0003] However, existing testing of bipolar plate airtightness is a customized technology. A single testing device can only be matched with bipolar plates of a certain shape. For bipolar plates of different shapes and sizes, a new testing device needs to be customized, which not only reduces testing efficiency but also brings high costs.

[0004] In view of this, a new technical solution is needed to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this application is to provide an airtightness testing device that is highly flexible, easy and quick to operate, and has low operating costs, and can test bipolar plates of different specifications and sizes.

[0006] To achieve the above objectives, this application employs the following technical means:

[0007] This application provides an airtightness testing device, comprising:

[0008] The cover plate and the bottom plate are arranged opposite to each other. The cover plate is provided with an air inlet channel. The two ends of the air inlet channel are respectively provided with a first connector and an air inlet hole. The air inlet hole is located on the inner side of the cover plate. The bottom plate is provided with an air outlet channel. The two ends of the air inlet channel are respectively provided with a second connector and an air outlet hole. The air outlet hole is located on the inner side of the bottom plate.

[0009] A sealing gasket with a cutout area that matches the workpiece to be tested;

[0010] An inflation device, connected to the first connector of the cover plate, is used to deliver gas into the air intake passage;

[0011] The air detection device, connected to the second connector of the base plate, is used to detect changes in air pressure within the airway.

[0012] During measurement, the workpiece to be measured is clamped between the cover plate and the base plate in the mold-closed state, and the sealing pad is placed on the side of the workpiece to be measured facing the base plate.

[0013] As a further improvement, a partition is also included, which has ventilation holes extending through its upper and lower surfaces.

[0014] As a further improvement, the inner side of the base plate is provided with several guide pillars, and the cover plate is provided with the same number of guide holes; when the mold is closed, the guide pillars are inserted into the guide holes.

[0015] As a further improvement, the cover plate is provided with weight-avoidance holes.

[0016] As a further improvement, a groove is provided on the inner side of the base plate, and the contour of the groove is consistent with the contour of the sealing gasket.

[0017] As a further improvement, the bottom wall of the groove is engraved with intersecting horizontal and vertical grooves, and the air outlet is located at the intersection of the two grooves.

[0018] As a further improvement, the gas detection device is a U-shaped column, which is fixedly connected to the front side of the base plate.

[0019] As a further improvement, it also includes a support plate and two clamping plates, one side of which is provided with an arc-shaped groove; the support plate is fixed to the front side of the base plate, and the two clamping plates respectively clamp the end tube of the U-shaped column onto the support plate.

[0020] As a further improvement, several support blocks are also included, all of which are fixedly connected to the bottom surface of the base plate.

[0021] As a further improvement, the upper surface of the cover plate is also provided with two symmetrical handles.

[0022] Compared with existing technologies, this application brings the following technical effects:

[0023] The airtightness testing equipment of this application, after the cover plate and base plate are molded together, holds the workpiece to be tested between them. A sealing gasket is placed on the side of the workpiece facing the base plate, and the sealing gasket has a hollowed-out area that matches the shape and contour of the workpiece. This creates a testing air path. The air inlet is connected to an inflation device, which introduces stable gas into the air inlet. The air outlet is connected to a gas detection device, allowing for the measurement of pressure changes within the outlet. If a crack exists in the bipolar plate, the gas can be measured by the gas detection device, thus completing the airtightness test. This testing equipment has a simple structure, is easy to operate, and has low manufacturing costs. The hollowed-out area of ​​the sealing gasket can be cut into different shapes as needed, thus enabling airtightness testing of bipolar plates of different specifications and improving the equipment's adaptability. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A perspective view of the airtightness testing equipment of this embodiment is shown from the front.

[0026] Figure 2 A perspective view of the rear of the airtightness testing device of this embodiment is shown;

[0027] Figure 3 A structural diagram of the base plate of the airtightness testing equipment of this embodiment is shown (some parts are omitted);

[0028] Figure 4 It shows Figure 3 A magnified view of a section at point A in the middle;

[0029] Figure 5 A structural diagram of the cover plate of the airtightness testing device of this embodiment is shown;

[0030] Figure 6 A simplified schematic diagram illustrating the principle of measuring three bipolar plates in this embodiment is shown.

[0031] Explanation of key component symbols:

[0032] Cover plate-10; Air inlet-12; First connector-13; Guide hole-14; Weight avoidance hole-16; Handle-17; Base plate-20; Air outlet-22; Second connector-23; Guide post-24; Support plate-25; Clamping plate-26; Support block-27; Groove-28; Slot-29; Sealing gasket-30; Partition plate-40; U-shaped column-50; Bipolar plate-90. Detailed Implementation

[0033] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] Please see Figures 1-6This embodiment provides an airtightness testing device for testing the airtightness of a workpiece. The workpiece specifically refers to the bipolar plate 90 within a fuel cell. This bipolar plate 90 is generally flat and has various grooves or channels. The material used for the bipolar plate 90 mainly includes graphite, a material that is brittle and easily broken. Furthermore, due to the thinness of the bipolar plate 90 itself, it is more prone to fracture. The airtightness testing described in this embodiment primarily aims to detect structural defects such as cracks and pores penetrating both sides of the bipolar plate 90, thereby screening out unqualified products. Specifically, in this embodiment, multiple bipolar plates 90 are stacked together for measurement, and each bipolar plate 90 is rectangular, as detailed below.

[0035] In this embodiment, the airtightness testing device includes a cover plate 10, a base plate 20, a sealing gasket 30, a partition 40, an inflation device (not shown), and an air detection device. The cover plate 10 and the base plate 20 are both made of heavy metal plates, and the partition 40 is made of the same metal material but is thinner.

[0036] The cover plate 10 has an air inlet channel (not shown) inside, and an air inlet hole 12 on the side of the cover plate 10 facing the base plate 20. The other end of the air inlet channel is connected to an inflation device through a first connector 13, thereby achieving the purpose of continuously inflating the cover plate 10. The base plate 20 has an air outlet channel (not shown) inside, and an air outlet hole 22 on the side of the base plate 20 facing the cover plate 10. The other end of the air outlet channel is connected to an air detection device through a second connector 23, thereby enabling the detection of changes in air pressure inside the base plate 20.

[0037] It should be noted that the specific shape of the intake and exhaust ducts is not particularly limited; they can be horizontal, vertical, or S-shaped, as long as they remain connected. However, in general, they should be designed from the perspective of facilitating manufacturing.

[0038] In this embodiment, four guide pillars 24 are provided around the base plate 20, and correspondingly, four guide holes 14 are provided around the cover plate 10. During mold closing, the guide pillars 24 are inserted into the guide holes 14, thereby aligning the cover plate 10 and the base plate 20 vertically, ensuring a smoother mold closing process and preventing displacement.

[0039] In this embodiment, the number of sealing pads 30 is the same as the number of bipolar plates 90 to be tested, and the number of partitions 40 is one less than the number of bipolar plates 90 to be tested. For example, if there are three bipolar plates 90 to be tested, then three sealing pads 30 and two partitions 40 are provided. The sealing pads 30 are plate-shaped, with a hollow area on them that corresponds to the outline of the bipolar plate 90, i.e., a rectangular hollow area. This hollow area is slightly smaller than the maximum outline of the bipolar plate 90 so that the bipolar plate 90 can be supported (or rested) on the edge of the hollow area. The hollow area of ​​the sealing pads 30 in this embodiment can be flexibly cut according to the specific shape and size of the bipolar plate 90. Therefore, the airtightness testing equipment of this application can be applied to bipolar plates 90 of different sizes and specifications, thereby improving the applicability.

[0040] Each partition 40 has ventilation holes (not shown in the figure) extending through the upper and lower surfaces of the partition 40. In actual use, the partition 40 is used in conjunction with a sealing gasket 30, see [reference needed]. Figure 6 The bottom sealing pad 30 does not need to be equipped with a partition 40, but directly cooperates with the bottom plate 20.

[0041] In this embodiment, the gas detection device is a U-shaped column 50, which is fixedly installed on one side wall of the base plate 20. Specifically, a support plate 25 is fixedly installed on the front side wall of the base plate 20, and two clamping plates 26 respectively clamp the two end tubes of the U-shaped column 50 onto the support plate 25. One side of the clamping plate 26 is provided with an arc-shaped groove that matches the end tube. Finally, a hose is used to connect one end tube to the connector of the gas outlet channel. When in use, a certain amount of liquid is injected into the U-shaped column 50. It uses the principle of connecting pipes to detect whether there is a pressure difference between the two end tubes. Therefore, once gas flows out of the gas outlet channel, the liquid surface on the U-shaped column 50 will be uneven, indicating that there is a crack on the bipolar plate 90. This gas detection device has a simple structure, low cost, and the test results are intuitive and reliable. It is worth mentioning that in other embodiments, other gas detection devices that indicate changes in air pressure can also be used.

[0042] In this embodiment, the inflation device is an existing device capable of inflation, such as a system consisting of a blower and a pipe. Instruments such as a barometer can also be installed on the pipe, which will not be described in detail here.

[0043] Please see Figure 6 The testing process and principle of this embodiment are as follows:

[0044] 1. Stack the bipolar plate 90 to be tested, the sealing software, and the partition 40 together vertically;

[0045] Among them, the air inlet 12 of the cover plate 10, the hollow area of ​​the sealing gasket 30, the air vent of the partition plate 40 and the air outlet 22 of the bottom plate 20 must be kept connected (in the case of cracks in the bipolar plate 90) and there must be no blockage of the air passage.

[0046] 2. The cover plate 10 and the base plate 20 are closed together under a certain pressure;

[0047] In this embodiment, the cover plate 10 and the base plate 20 have aligned through holes (not shown in the figure) at their edges. The two are pressed together by bolts and nuts to maintain a certain pressure and prevent air leakage between the bipolar plate 90 and the sealing gasket 30. Of course, other pressure-maintaining methods can also be used.

[0048] 3. Start the inflation device and observe the change in the liquid level in the U-shaped column 50.

[0049] If the liquid surface in the U-shaped column 50 is uneven, it indicates that there are cracks in all three bipolar plates 90.

[0050] If there are no abnormalities on the liquid surface of the U-shaped column 50, then at least one of the three bipolar plates 90 on the surface is qualified. At this point, further testing is required on each bipolar plate 90, or two of them. After multiple rounds of testing, the final result can be obtained as to which bipolar plate 90 is qualified and which bipolar plate 90 has cracks.

[0051] It should be noted that, during the use of this testing equipment, no sealing gasket 30 is placed between the bipolar plate 90 and the upper layer structure; instead, a sealing gasket 30 is placed only between the bipolar plate 90 and the lower layer structure. This is because the inflation device continuously inflates the air intake channel. If sealing gaskets 30 were placed on both the upper and lower surfaces of the bipolar plate 90, the air pressure in the entire air path would continuously increase and could not maintain a constant value. In this embodiment, the upper surface of the bipolar plate 90 is in contact with the cover plate 10 or the partition plate 40, which involves the contact of two rigid surfaces. A gap inevitably exists between them, thus allowing for air leakage and ultimately maintaining a constant air pressure in the testing air path. This is beneficial for airtightness testing. Of course, this leakage will not affect the airtightness test results of the bipolar plate 90.

[0052] It should be noted that the sealing pad 30 in this embodiment is used to detect whether there are cracks on the entire surface of the bipolar plate 90. It is easy to understand that in some other embodiments, a specific area of ​​the bipolar plate 90 can also be detected. Specifically, the hollow area of ​​the sealing pad 30 is opened in the area to be tested, which is directly opposite the bipolar plate 90.

[0053] Furthermore, although the above embodiments demonstrate the measurement of multiple bipolar plates 90 together, this application can also perform airtightness testing on a single bipolar plate 90, based on the same principle, which will not be repeated here. When testing a single bipolar plate 90, the partition 40 is not required.

[0054] In a preferred embodiment, the cover plate 10 is provided with a plurality of weight-avoidance holes 16, thereby reducing the weight of the cover plate 10. Of course, the weight-avoidance holes 16 need to be positioned away from the air intake passage to avoid air leakage.

[0055] In a preferred embodiment, two handles 17 are symmetrically provided on the cover plate 10 to facilitate the user in lifting and moving the cover plate 10.

[0056] In a preferred embodiment, several support blocks 27 are also provided below the base plate 20. The support blocks 27 raise the base plate 20 to a certain height, thereby providing the necessary space for the installation of the U-shaped column 50.

[0057] In a preferred embodiment, a groove 28 is provided on the side of the base plate 20 facing the cover plate 10. The outline of the groove 28 is consistent with the outline of the sealing pad 30, so that the sealing pad 30 can be stably placed on the base plate 20 and avoid movement.

[0058] Even better, the bottom wall of the groove 28 is also engraved with crisscrossing grooves 29, and the vent 22 is located at the intersection of the two grooves 29, one vertical and one horizontal. This arrangement can prevent the vent 22 from being blocked.

[0059] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom still fall within the scope of protection of this application.

Claims

1. A hermeticity testing apparatus, characterized by, include: The cover plate and the bottom plate are arranged opposite each other. The cover plate is provided with an air intake passage. The two ends of the air intake passage are respectively provided with a first connector and an air intake hole. The air intake hole is located on the inner side of the cover plate. The base plate is provided with an air outlet channel, and the two ends of the air inlet channel are respectively provided with a second connector and an air outlet hole, and the air outlet hole is located on the inner side of the base plate. A sealing gasket with a cutout area that matches the workpiece to be tested; An inflation device, connected to the first connector of the cover plate, is used to deliver gas into the air intake passage; The air detection device, connected to the second connector of the base plate, is used to detect changes in air pressure within the airway. During measurement, the workpiece to be measured is clamped between the cover plate and the base plate in the mold-closed state, and the sealing pad is placed on the side of the workpiece to be measured facing the base plate.

2. The air tightness testing apparatus of claim 1, wherein, It also includes a partition, which has ventilation holes extending through its upper and lower surfaces.

3. The air tightness testing apparatus of claim 1, wherein, The inner side of the base plate is provided with several guide pillars, and the cover plate is provided with the same number of guide holes; when the mold is closed, the guide pillars are inserted into the guide holes.

4. The air tightness testing apparatus of claim 1, wherein, The cover plate is provided with a weight-avoidance hole.

5. The air tightness testing apparatus of claim 1, wherein, The inner side of the base plate is provided with a groove, the outline of which is consistent with the outline of the sealing gasket.

6. The air tightness testing apparatus of claim 5, wherein, The bottom wall of the groove is engraved with intersecting horizontal and vertical grooves, and the air outlet is located at the intersection of the two grooves.

7. The air tightness testing apparatus of claim 1, wherein, The gas detection device is a U-shaped column, which is fixedly connected to the front side of the base plate.

8. The air tightness testing apparatus of claim 7, wherein, It also includes a support plate and two clamping plates, one side of which is provided with an arc-shaped groove; the support plate is fixed to the front side of the base plate, and the two clamping plates respectively clamp the end tube of the U-shaped column onto the support plate.

9. The air tightness testing apparatus of claim 1, wherein, It also includes several support blocks, all of which are fixedly connected to the bottom surface of the base plate.

10. The air tightness testing apparatus of claim 1, wherein, The upper surface of the cover plate is also provided with two symmetrical handles.

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