Fuel cell bipolar plate air tightness detection clamp

Abstract

The utility model discloses a fuel cell bipolar plate air tightness detection clamp comprising a cover plate and an upper pressing plate fixed on a machine table, and the cover plate is provided with a first sealing groove having the same shape as the bipolar plate; the bottom plate is fixed on a lower pressing plate of the machine table and directly faces the cover plate, and a second sealing groove with the same shape as the polar plate is formed in the bottom plate; a first sealing strip is clamped in the first sealing groove, and a second sealing strip is clamped in the second sealing groove; after the cover plate is pressed downwards and is closed with the bottom plate, the bipolar plate is divided into a plurality of detection areas by the first sealing strips and the second sealing strips; a plurality of air channels are arranged on the side face of the bottom plate and used for supplying air to the detection area. Through the sealing strip with the section in a specific shape and the groove matched with the sealing strip in shape on the clamp, the sealing strip can be fixed on the clamp without gluing, so that the problems that the air tightness test is influenced due to non-uniform gluing and the residual glue needs to be cleaned during disassembly are avoided, and the production efficiency is improved. And the installation and test efficiency is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of airtightness testing fixtures, and in particular to an airtightness testing fixture for fuel cell bipolar plates. Background Technology

[0002] A fuel cell is a device that converts chemical energy into electrical energy, in which the metal bipolar plate plays a crucial role as a core component. Metal bipolar plates are typically produced by stamping thin metal sheets into anode and cathode plates, which are then joined together using laser welding to form the finished metal bipolar plate. During the welding process, the absolute integrity of the weld line must be ensured to avoid any defects such as incomplete welds, burn-through, bursts, or pressure damage, as these defects directly affect the independence and integrity of each functional area of ​​the plate. Furthermore, since the plates themselves are formed by stamping, their integrity must be rigorously inspected to ensure they are free from cracks or other defects, guaranteeing the proper functioning of the plates. Therefore, testing the integrity of the weld line and the plate substrate is an indispensable step. This necessitates the design of a testing fixture, and the sealing ring installed on the fixture is a critical component.

[0003] In existing technologies, the sealing ring of a bipolar plate airtightness fixture is typically bonded to the groove of the fixture by applying adhesive. The contact surface between the sealing ring and the bipolar plate also usually requires adhesive application to ensure airtightness. However, while this adhesive application method ensures the sealing ring is fixed, the adhesive thickness is difficult to control, easily leading to uneven application, which affects the airtightness test results or damages the bipolar plate. Furthermore, when disassembling the bipolar plate after airtightness testing, the adhesive-fixed sealing ring can easily stick to the bipolar plate, making disassembly difficult. Utility Model Content

[0004] To address the shortcomings of the existing technology, the technical problem to be solved by this utility model is to provide a fuel cell bipolar plate airtightness testing fixture. By using a sealing strip with a specific cross-section and a groove on the fixture that matches the shape of the sealing strip, the sealing strip can be fixed on the fixture without the need for adhesive bonding. This avoids the impact of uneven adhesive application on airtightness testing and the need to clean residual adhesive during disassembly, greatly improving installation and testing efficiency.

[0005] To solve the above-mentioned technical problems, the present invention provides a technical solution: a fuel cell bipolar plate airtightness testing fixture, comprising:

[0006] A cover plate, fixed to the upper pressure plate of the machine base, is provided with a first sealing groove that is the same shape as the bipolar plate;

[0007] The base plate is fixed to the lower pressure plate of the machine tool and faces the cover plate. The base plate has a second sealing groove with the same shape as the bipolar plate.

[0008] A first sealing strip is embedded in the first sealing groove, and a second sealing strip is embedded in the second sealing groove. The second pole of the bipolar plate can be attached to the second sealing strip and fixed on the base plate.

[0009] After the cover plate is pressed down and closed with the bottom plate, the first pole of the bipolar plate can fit with the first sealing strip, and the first and second sealing strips divide the bipolar plate into several detection areas.

[0010] The base plate has several air channels on its side for supplying air to the detection area.

[0011] Furthermore, both the first and second sealing grooves have convex cross-sections, with a groove body having a larger cross-sectional size and a slot opening having a smaller cross-sectional size; both the first and second sealing strips have convex cross-sections, allowing the first sealing strip to be snapped into the first sealing groove, and having a limiting part with a larger cross-sectional size that is embedded in the groove body and a sealing part with a smaller cross-sectional size that extends out of the slot opening.

[0012] Furthermore, the cross-sectional dimensions of the first sealing strip and the second sealing strip are adapted to the cross-sectional dimensions of the first sealing groove and the second sealing groove.

[0013] Furthermore, the bipolar plate includes a hydrogen inlet, a hydrogen outlet, an oxygen inlet, an oxygen outlet, a coolant inlet, and a coolant outlet; the hydrogen inlet, oxygen inlet, and coolant inlet are located on one side of the reaction zone of the bipolar plate, and the hydrogen outlet, oxygen outlet, and coolant outlet are located on the other side.

[0014] Furthermore, the outline of the first sealing groove is the same as the outline of the first electrode, and the outline of the second sealing groove is the same as the outline of the second electrode; after the cover plate is pressed down and closed with the bottom plate, the outlines of the hydrogen inlet, hydrogen outlet, oxygen inlet, oxygen outlet, coolant inlet and coolant outlet are respectively attached to the first sealing strip and the second sealing strip, forming a detection area.

[0015] Furthermore, the number of airways is the same as the number of detection zones, and each airway connects to only one detection zone.

[0016] Furthermore, at least one through hole is provided on the top of the base plate, and a positioning bushing is fixed in the through hole.

[0017] Furthermore, a positioning pin is fixed on the opposite surface of the cover plate and the base plate. After the cover plate is pressed down and closed with the base plate, the positioning pin is inserted into the positioning bushing.

[0018] Furthermore, the top of the base plate is provided with at least two first positioning holes, which match the second positioning holes provided on the bipolar plate, so that the bipolar plate can be positioned and fixed on the top of the base plate.

[0019] Furthermore, the area of ​​the upper pressure plate is larger than that of the cover plate, and the upper pressure plate can completely cover the cover plate; the area of ​​the lower pressure plate is larger than that of the bottom plate, and the lower pressure plate can completely cover the bottom plate.

[0020] This utility model discloses a fuel cell bipolar plate air tightness testing fixture, which has at least the following beneficial effects: 1. This utility model uses a sealing strip with a specific cross-section and a groove on the fixture that matches the shape of the sealing strip, so that the sealing strip can be fixed on the fixture without applying glue, thereby avoiding the impact of uneven glue application on air tightness testing and the need to clean residual glue during disassembly, greatly improving the efficiency of installation and testing; 2. The positioning pin on the cover plate and the positioning bushing on the base plate cooperate to make the joint between the cover plate and the base plate more precise, improving the accuracy of fuel cell bipolar plate air tightness testing. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a schematic diagram of one embodiment of the airtightness testing fixture of this utility model.

[0023] Figure 2 This is an exploded view of one embodiment of the airtightness testing fixture of this utility model.

[0024] Figure 3 for Figure 2 A magnified view of a portion of point A in the middle.

[0025] Figure 4 for Figure 2 A magnified view of a section at point B in the middle.

[0026] Figure 5 This is a front view of one embodiment of the airtightness testing fixture of this utility model.

[0027] Figure 6 for Figure 5 A cross-sectional view along the CC direction.

[0028] Figure 7 for Figure 6 A magnified view of a section at point D.

[0029] Explanation of reference numerals in the attached figures:

[0030] Upper pressure plate-1; Lower pressure plate-2; Cover plate-3; First sealing groove-31; First sealing strip-32; Positioning pin-33; Base plate-4; Second sealing groove-41; Second sealing strip-42; Air passage-43; Through hole-44; Positioning bushing-45; First positioning hole-46; Bipolar plate-5; Second positioning hole-51; Positioning piece-52. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings.

[0032] Please see Figure 1 , Figure 1 This is a schematic diagram of one embodiment of the fuel cell bipolar plate airtightness testing fixture of this utility model. The fuel cell bipolar plate airtightness testing fixture may specifically include a cover plate 3 and an upper pressure plate 1 fixed to the machine base. The cover plate 3 has a first sealing groove 31 with the same shape as the bipolar plate 5.

[0033] The base plate 4 is fixed to the lower pressure plate 2 of the machine base and faces the cover plate 3. The base plate 4 has a second sealing groove 41 with the same shape as the bipolar plate 5.

[0034] A first sealing strip 32 is embedded in the first sealing groove 31, and a second sealing strip 42 is embedded in the second sealing groove 41. The second pole of the bipolar plate 5 can be attached to and fixed to the base plate 4 with the second sealing strip 42.

[0035] After the cover plate 3 is pressed down and closed with the bottom plate 4, the first pole of the bipolar plate 5 can fit with the first sealing strip 32, and the first sealing strip 32 and the second sealing strip 42 divide the bipolar plate 5 into several detection areas.

[0036] The side of the base plate 4 is provided with several air channels 43 for supplying air to the detection area.

[0037] The aforementioned machine, upper pressure plate 1, lower pressure plate 2, cover plate 3, and base plate 4 constitute the conventional structural configuration of an airtightness testing fixture. The machine serves as the pressurization mechanism for this fuel cell bipolar plate airtightness testing fixture. The cover plate 3 is fixed to the upper pressure plate 1 of the machine, and the base plate 4 is fixed to the lower pressure plate 2. When the upper and lower pressure plates 1 and 2 are separated, the base plate 4 and cover plate 3 are positioned directly opposite each other. This ensures that when the upper pressure plate 1 is pressed down, the cover plate 3 can perfectly match and engage with the base plate 4, thereby improving testing efficiency. Unlike conventional designs, this solution incorporates sealing grooves in both the cover plate 3 and the base plate 4. A first sealing groove 31 is located on the lower surface of the cover plate 3 (the surface opposite the top surface of the base plate 4), while a second sealing groove 41 is located on the top surface of the base plate 4. These two sealing grooves serve to house sealing rings. A first sealing strip 32 can be fitted into the first sealing groove 31, and a second sealing strip 42 can be fitted into the second sealing groove 41. Furthermore, to ensure proper fit between the two sealing strips and the bipolar plate 5, the first and second sealing grooves 31 and 41 must be pre-designed to match the shape of the bipolar plate 5. This allows the second electrode of the bipolar plate 5 to be fixedly installed on the base. The sealing strip 42 can naturally fit the second pole of the bipolar plate 5. At the same time, after the upper pressure plate 1 drives the cover plate 3 to press down and the cover plate 3 is joined with the bottom plate 4, the first sealing strip 32 can naturally fit the first pole of the bipolar plate 5. At this time, the two poles of the bipolar plate 5 are respectively fitted with the corresponding sealing strips. Therefore, the first sealing strip 32 and the second sealing strip 42, i.e. the bipolar plate 5, are divided into several detection areas (the number of which is determined by the structure of the bipolar plate 5, and the detection area is the area of ​​the bipolar plate 5 that needs to be tested for air tightness). Then, according to the location of the detection area, several air passages 43 can be set on the bottom plate 4 so that the air passages 43 are connected to the above-mentioned detection areas. Air can be supplied to the detection area through the air supply component to complete the air tightness test of the bipolar plate 5.

[0038] In some implementations, please refer to Figure 6 and Figure 7The first sealing groove 31 and the second sealing groove 41 both have convex cross-sections, with a large cross-sectional area and a small cross-sectional opening. The first sealing strip 32 and the second sealing strip 42 also have convex cross-sections, allowing the first sealing strip 32 to be snapped into the first sealing groove 31 and the second sealing strip 42 to be snapped into the second sealing groove 41. The second sealing strip 42 has a large cross-sectional area embedded in the groove and a small cross-sectional area extending out of the opening. To avoid the problems of uneven adhesive application affecting airtightness testing and the need to clean residual adhesive during disassembly that can occur with traditional adhesive bonding methods, this solution employs a snap-fit ​​connection, different from traditional adhesive bonding. It utilizes a first sealing strip and a second sealing strip 42 with the same cross-sectional shape as the first sealing groove 31 and the second sealing groove 41, both with convex or inverted T-shaped cross-sections. This allows the first sealing strip 32 to be directly snapped into the first sealing groove 31 and the second sealing strip 42 to be directly snapped into the second sealing groove 41, without the need for adhesive bonding.

[0039] To further improve the sealing effect of the sealing strips, the height of the first sealing strip 32 and the second sealing strip 42 can be set higher than the first sealing groove 31 and the second sealing groove 41. This means that when the first sealing strip 32 is engaged in the first sealing groove 31, the top of the first sealing strip 32 protrudes a certain distance from the opening of the first sealing groove 31, and when the second sealing strip 42 is engaged in the second sealing groove 41, the top of the second sealing strip 42 protrudes a certain distance from the opening of the second sealing groove 41. In this way, when the upper pressure plate 1 drives the cover plate 3 to press down and close with the bottom plate 4, the two ends of the bipolar plate 5 are respectively attached to the first sealing strip 32 and the second sealing strip 42. Simultaneously, under the squeezing action of the cover plate 3 and the bottom plate 4, the ends of the first sealing strip 32 and the second sealing strip 42 that protrude from the openings of the first sealing groove 31 and the second sealing groove 41 are also squeezed, causing them to deform towards both sides of the opening. This improves the sealing effect of the first sealing strip 32 and the second sealing strip 42, thereby increasing the detection efficiency of the airtightness of the bipolar plate 5.

[0040] It should be noted that, in order to facilitate the installation between the first sealing strip 32 and the first sealing groove 31, the second sealing strip 42 and the second sealing groove 41, the cross-sectional dimensions of the first sealing strip 32 and the second sealing strip 42 can be adapted to the cross-sectional dimensions of the first sealing groove 31 and the second sealing groove 41.

[0041] Please see Figure 2The bipolar plate 5 includes six fluid inlets and outlets: a hydrogen inlet, a hydrogen outlet, an oxygen inlet, an oxygen outlet, a coolant inlet, and a coolant outlet. The hydrogen inlet, oxygen inlet, and coolant inlet are located on one side of the reaction zone of the bipolar plate, while the hydrogen outlet, oxygen outlet, and coolant outlet are located on the other side. The arrangement of these fluid inlets and outlets on the bipolar plate 5 is conventional. The outline of the first sealing groove 31 is the same as the outline of the first electrode, and the outline of the second sealing groove 41 is the same as the outline of the second electrode. After the cover plate 3 is pressed down and closed with the base plate 4, both sides of the outlines of the hydrogen inlet, hydrogen outlet, oxygen inlet, oxygen outlet, coolant inlet, and coolant outlet are respectively abutted against the first sealing strip 32 and the second sealing strip 42, forming a detection area.

[0042] Please see Figure 5 and Figure 6 The number of air passages 43 is the same as the number of detection zones, and each air passage 43 connects to only one detection zone. In this scheme, there are 6 air passages 43 and 6 detection zones, which is the number of fluid inlets and outlets of the bipolar plate 5. The number of detection zones is also determined by the structure of the bipolar plate 5 itself, that is, the number of fluid inlets and outlets of the bipolar plate 5. The number of air passages 43 can be adjusted adaptively according to the number of detection zones. At the same time, one end of the air passage 43 is naturally opened in the detection zone, while the other end can be set according to actual needs, or it can be directly set on the side of the base, so as to facilitate the air supply component to supply air to the detection zone.

[0043] Please see Figure 2 To facilitate the alignment between the cover plate 3 and the base, this design also includes a through hole 44 on the top of the base plate 4, with a positioning bushing 45 fixed within it. Simultaneously, a positioning pin 33 is fixed on the cover plate 3 at a position corresponding to the base plate 4. This ensures that after the cover plate 3 moves under the action of the upper pressure plate 1 and closes with the base plate 4, the positioning pin 33 can be inserted into the positioning bushing 45, thereby improving the positioning accuracy between the cover plate 3 and the base plate 4, and consequently enhancing the airtightness detection effect of the bipolar plate 5 in both the cover plate 3 and the base plate 4. It is worth noting that one or more through holes 44 can be provided. This design symmetrically provides through holes 44 on both sides of the top of the base, further improving the stability between the cover plate 3 and the base after the cover plate 3 moves under the action of the upper pressure plate 1 and closes with the base plate 4.

[0044] Please see Figure 3 and Figure 4In this design, at least one first positioning hole 46 can be formed on the top of the base plate 4. This first positioning hole 46 can match the second positioning hole 51 on the bipolar plate 5, so that the bipolar plate 5 can be directly positioned and fixed through the first positioning hole 46 and the second positioning hole 51 during fixing, thereby improving the fixing stability of the bipolar plate 5 and thus improving the airtightness testing effect of the bipolar plate 5. It should be noted that the second positioning hole 51 can be formed on a positioning piece 52 extending from the edge of the bipolar plate 5, so that the excess material of the positioning piece can be removed after the bipolar plate 5 has been tested.

[0045] In some embodiments, the area of ​​the upper pressure plate 1 can be set to be larger than the area of ​​the cover plate 3, and the upper pressure plate 1 can completely cover the cover plate 3. At the same time, the area of ​​the lower pressure plate 2 is larger than the bottom plate 4, and the lower pressure plate 2 can completely cover the bottom surface of the bottom plate 4. This arrangement makes the first sealing strip 32 and the second sealing strip 42 between the cover plate 3 and the bottom plate 4 more uniformly stressed after the upper pressure plate 1 drives the cover plate 3 to press down and close with the bottom plate 4. This makes the deformation of the first sealing strip 32 and the second sealing strip 42 more uniform, further improving the airtightness detection effect of the bipolar plate 5.

[0046] This solution utilizes a sealing strip with a specific cross-sectional shape and a groove on the clamp that matches the shape of the sealing strip. This allows the sealing strip to be fixed to the clamp without the need for adhesive bonding, thus avoiding the impact of uneven adhesive application on airtightness testing and the need to clean residual adhesive during disassembly. This greatly improves the efficiency of installation and testing. Furthermore, the positioning pin 33 on the cover plate 3 and the positioning bushing 45 on the base plate 4 can cooperate to make the engagement between the cover plate 3 and the base plate 4 more precise, thereby improving the accuracy of airtightness testing of fuel cell bipolar plates.

[0047] The above description merely illustrates preferred embodiments of the present invention and is quite specific and detailed; however, it should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A fuel cell bipolar plate air tightness test fixture, characterized by, include: A cover plate, fixed to the upper pressure plate of the machine base, is provided with a first sealing groove that is the same shape as the bipolar plate; The base plate is fixed to the lower pressure plate of the machine tool and faces the cover plate. The base plate has a second sealing groove with the same shape as the bipolar plate. A first sealing strip is embedded in the first sealing groove, and a second sealing strip is embedded in the second sealing groove. The second pole of the bipolar plate can be attached to the second sealing strip and fixed on the base plate. After the cover plate is pressed down and closed with the bottom plate, the first pole of the bipolar plate can fit with the first sealing strip, and the first and second sealing strips divide the bipolar plate into several detection areas. The base plate has several air channels on its side for supplying air to the detection area.

2. The fuel cell bipolar plate air tightness test fixture of claim 1, wherein, The first sealing groove and the second sealing groove both have convex cross-sections, with a groove body with a larger cross-sectional size and a groove opening with a smaller cross-sectional size; the first sealing strip and the second sealing strip both have convex cross-sections, with a limiting part with a larger cross-sectional size that is embedded in the groove body and a sealing part with a smaller cross-sectional size that extends out of the groove opening.

3. The fuel cell bipolar plate air tightness test fixture of claim 2, wherein, The cross-sectional dimensions of the first sealing strip and the second sealing strip are adapted to the cross-sectional dimensions of the first sealing groove and the second sealing groove.

4. The fuel cell bipolar plate air tightness test fixture of claim 1, wherein, The bipolar plate includes a hydrogen inlet, a hydrogen outlet, an oxygen inlet, an oxygen outlet, a coolant inlet, and a coolant outlet; the hydrogen inlet, oxygen inlet, and coolant inlet are located on one side of the reaction zone of the bipolar plate, and the hydrogen outlet, oxygen outlet, and coolant outlet are located on the other side.

5. The fuel cell bipolar plate air tightness test fixture of claim 4, wherein, The outline of the first sealing groove is the same as the outline of the first pole, and the outline of the second sealing groove is the same as the outline of the second pole. After the cover plate is pressed down and closed with the bottom plate, the outlines of the hydrogen inlet, hydrogen outlet, oxygen inlet, oxygen outlet, coolant inlet and coolant outlet are respectively attached to the first sealing strip and the second sealing strip, forming a detection area.

6. The fuel cell bipolar plate air tightness test fixture of claim 5, wherein, The number of airways is the same as the number of detection zones, and each airway connects to only one detection zone.

7. The fuel cell bipolar plate air tightness test fixture of claim 1, wherein The top of the base plate is also provided with at least one through hole, and a positioning bushing is fixed in the through hole.

8. The fuel cell bipolar plate air tightness test fixture of claim 7, wherein, A positioning pin is fixed on the opposite surface of the cover plate and the base plate. After the cover plate is pressed down and closed with the base plate, the positioning pin is inserted into the positioning bushing.

9. The fuel cell bipolar plate air tightness test fixture of claim 1, wherein, The top of the base plate is also provided with at least two first positioning holes, which match the second positioning holes provided on the bipolar plate, so that the bipolar plate can be positioned and fixed on the top of the base plate.

10. The fuel cell bipolar plate air tightness test fixture of claim 1, wherein, The area of ​​the upper pressure plate is larger than that of the cover plate, and the upper pressure plate can completely cover the cover plate; the area of ​​the lower pressure plate is larger than that of the bottom plate, and the lower pressure plate can completely cover the bottom plate.

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