Batch detection device for air tightness of hydrogen fuel cell stack

Abstract

The invention relates to the technical field of hydrogen fuel cell detection, in particular to a hydrogen fuel cell stack airtightness batch detection device. Comprising a conveying mechanism and a detection mechanism, the conveying mechanism is provided with a plurality of bearing positions, each bearing position is provided with a lower carrier capable of containing a plurality of batteries at the same time, the detection mechanism comprises an upper carrier and a pressure maintaining assembly, and when the upper carrier and the lower carrier are closed, the pressure maintaining assembly is arranged on the upper carrier. A sealing cavity for independently accommodating each battery and an air passage for communicating air ports of the adjacent batteries are formed between the upper carrier and the lower carrier, the upper carrier is also provided with a pressurizing structure, the pressurizing structure is provided with a ventilation pipe sleeve and a closed pipe sleeve, and the ventilation pipe sleeve and the closed pipe sleeve are respectively provided with a linkage piece matched with the pressure maintaining assembly. According to the invention, the upper carrier and the lower carrier are closed to form the sealed cavity for accommodating a plurality of batteries therein, and the ventilation pipe sleeve and the closed pipe sleeve are in sealed butt joint with the corresponding battery gas ports through the synergistic effect of the pressure maintaining assembly and the linkage piece, so that the detection accuracy and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen fuel cell detection, and specifically relates to a batch detection device for the air tightness of a hydrogen fuel cell stack. Background Art

[0002] During the production and detection of hydrogen fuel cell stacks, air tightness detection is a key link to ensure their safety and performance. Currently, traditional air tightness detection devices mostly adopt the method of individually testing single cells. By placing the cell in a sealed cavity, inflating and pressurizing it, and then monitoring the pressure change to determine whether there is leakage. Since the cell has an air inlet and an air outlet, generally, it is inflated through the air inlet while closing the air outlet, so as to detect whether there is air leakage after the cell is pressurized to a predetermined value. However, this method has two problems. Firstly, the detection efficiency is low, making it difficult to meet the requirements of large-scale and continuous production. Secondly, the operation is complex. Each time, a single stack needs to be clamped and inflated, increasing manual intervention and the probability of errors.

[0003] A hydrogen fuel cell stack defect detection device and its detection method with the Chinese patent authorization announcement number CN115588761B currently disclosed includes a transportation component. The transportation component includes a conveyor belt driven by a driving roller, and a plurality of linearly distributed and spaced positioning material holes are arranged on the conveyor belt, and a bearing tray is clamped in the positioning material holes; a fuel cell, the lower end of the fuel cell is installed on the bearing tray, and interface components are arranged on both sides of the upper end of the fuel cell, and a connection end is arranged at the upper end of the fuel cell; a lifting component, the lifting component is fixedly installed in the middle inner cavity of the circulating conveyor belt, the lifting component includes a telescopic column, the end of the telescopic column is provided with a top plate, and the top of the top plate is directly opposite to the bearing tray; a detection component, the detection component is installed at the upper end of the conveyor belt, the detection component includes a detection box and a sealing end cover, the lower end port of the detection box is directly opposite to the top plate, the upper end of the detection box is hermetically connected with the sealing end cover, a sealing connection component is horizontally telescopically installed in the inner cavity of the detection box, an air inlet pump and an exhaust pump are symmetrically arranged at the upper end of the sealing end cover, the air inlet pump and the exhaust pump are hermetically connected with the interface component through the sealing connection component, and a pressure gauge for detecting the air pressure in the inner cavity is inserted and installed at the upper end of the sealing end cover.

[0004] According to the above-mentioned patent, the patent forms a sealed environment by setting up the cooperation of the lifting drive and the sealing detection box, enables the fuel cell to work by introducing gas, and detects whether the fuel cell leaks by detecting the internal pressure. With the drive of the conveyor belt, the workstations of loading, detection, and unloading are switched to achieve automated detection. However, when the sealing detection box is formed, the sealing between the sealing end cover and the detection box may be poor due to insufficient holding pressure, which is likely to cause misjudgment in airtightness detection. Moreover, the one-to-one detection mode is not efficient, and it takes a lot of time for batch detection. Therefore, there is currently a need for an airtightness batch detection device that can provide a sealed environment for the hydrogen fuel cell stack, ensure the stability of the sealed environment, and detect multiple hydrogen fuel cell stacks at the same time. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, a hydrogen fuel cell stack airtightness batch detection device is provided. A sealed cavity for accommodating multiple cells is formed by the closure of the upper carrier and the lower carrier. Through the synergistic action of the pressure maintaining component and the linkage component, the gas pipe sleeve and the closed pipe sleeve are hermetically docked with the cell gas ports during the downward pressing of the upper carrier. After the charging of the cells is completed, the valve rod structure is activated to cut off the airway connection, so that multiple cells enter an independent sealed state respectively and the airtightness detection is carried out synchronously, improving the detection accuracy and efficiency.

[0006] To solve the problems of the prior art, the present invention provides a hydrogen fuel cell stack airtightness batch detection device, including a conveying mechanism and a detection mechanism. The conveying mechanism has a plurality of loading positions, and each loading position is provided with a lower carrier capable of accommodating multiple cells at the same time. The detection mechanism includes an upper carrier capable of fitting with the lower carrier and a pressure maintaining component connected to the upper carrier. Both the lower carrier and the upper carrier have sealing surfaces that can fit tightly with each other. When the upper carrier and the lower carrier are closed, a sealed cavity for each cell to be separately accommodated and not communicating with each other and an air passage connecting the adjacent cell gas ports are formed between them. A leakage detection structure is provided on the upper carrier corresponding to each cell, and a charging structure capable of ventilating all cells is also provided on the upper carrier. The charging structure has a gas pipe sleeve and a closed pipe sleeve. The gas pipe sleeve and the closed pipe sleeve can be respectively connected to the gas ports of the two outermost cells among multiple cells. The gas pipe sleeve and the closed pipe sleeve are both provided with linkage components cooperating with the pressure maintaining component. When the pressure maintaining component drives the upper carrier to fit with the lower carrier and continuously applies pressure, the gas pipe sleeve and the closed pipe sleeve gradually approach the cells under the drive of the linkage components and are hermetically connected to the corresponding cell gas ports, so that all cells form a continuous gas flow path during the unified charging process.

[0007] Preferably, extension rods extending horizontally outward are provided at both ends of the upper carrier. A slider fixedly connecting the corresponding air pipe sleeve and the sealing pipe sleeve is slidably provided on each extension rod. The linkage is cooperatively provided between the slider and the pressure maintaining assembly. When the lower carrier moves to the detection station, the air pipe sleeve and the sealing pipe sleeve are respectively coaxial with the corresponding battery air ports.

[0008] Preferably, the linkage has a pressure-receiving part provided on the slider and a pressure-applying part provided on the pressure maintaining assembly. When the pressure-applying part acts on the pressure-receiving part following the downward movement of the pressure maintaining assembly, the upper carrier is in a relatively stationary state. At this time, the slider gradually approaches the upper carrier under the drive of the pressure-receiving part.

[0009] Preferably, a return spring is provided between the slider and the extension rod. When the slider gradually approaches the upper carrier, the return spring is in a compressed state. When the pressure-applying part disengages from the pressure-receiving part, the return spring drives the slider to be in a reset state, so that the connection between the air pipe sleeve and the sealing pipe sleeve and the corresponding battery air ports is released.

[0010] Preferably, the pressure-receiving part is specifically a block structure, and the pressure-applying part is specifically a rod structure. The pressure-receiving part has a slope extending obliquely outward from top to bottom. When the pressure-applying part applies the vertical pressure along the slope to the pressure-receiving part, the slider gradually receives an inward horizontal thrust along the extension rod.

[0011] Preferably, the pressure maintaining assembly includes a pressing plate and a hydraulic rod for driving the pressing plate to move. A plurality of guide rods vertically passing through the pressing plate are provided on the upper carrier. The pressing plate can move relative to the upper carrier along the guide rods. A buffer spring is further provided between the pressing plate and the upper carrier. When the pressing plate drives the upper carrier to fit with the lower carrier and continuously applies pressure, the buffer spring is in a compressed state.

[0012] Preferably, an anti-disengagement part is provided at the upper end of each guide rod. When the pressing plate contacts the anti-disengagement part, the buffer spring is in a normal state, and at the same time, the pressure-applying part and the pressure-receiving part are in a state of moving away from each other.

[0013] Preferably, a valve rod structure is provided at the position on the upper carrier corresponding to the formation of the air passage. When all the batteries are fully pressurized, the air passage is in a closed state under the drive of the valve rod structure, so that the gas flow path between adjacent batteries is cut off, forming an independent pressurization detection state.

[0014] Preferably, the air leakage detection structure has a pressure sensor and a pressure conduction member. A compression spring is provided between the pressure conduction member and the pressure sensor. When the pressure in the sealed cavity increases due to the pressure relief of the battery, the compression spring is in a compressed state under the pressure-receiving force of the pressure conduction member.

[0015] Preferably, the pressure conducting member has a plate body movably arranged on the upper carrier and an airbag fixedly arranged on the upper carrier. The airbag is located below the plate body. The plate body has a guide shaft that abuts against a compression spring. When the pressure in the sealed cavity increases and causes the airbag to expand, the plate body is in a jacked-up state under the pressure of the airbag.

[0016] The beneficial effects of this application compared with the prior art are as follows:

[0017] 1. Through the cooperation of the pressure maintaining component and the linkage component, the ventilation pipe sleeve and the closed pipe sleeve can approach the battery air port synchronously during the downward pressing process of the pressure maintaining component, achieving precise alignment and sealed connection with the battery air port. This ensures the stability and tightness of the gas flow path during the unified pressurization process, avoids leakage problems caused by connection deviation or poor sealing, and improves the accuracy and efficiency of detection.

[0018] And by placing multiple batteries on the lower carrier at the same time and forming multiple independent and non-interfering sealed cavities after the upper carrier and the lower carrier are fitted together, each battery can be subjected to airtightness detection under the same conditions. After all the batteries are synchronously pressurized to the target pressure, the air leakage detection structure can independently monitor the pressure changes in each sealed cavity, accurately identify the battery units with leakage, without interference, ensuring the accuracy of the detection results, and also avoiding the low efficiency problem caused by individual detection.

[0019] 2. Through the cooperation of the pressure-receiving part on the slider and the pressure-applying part on the pressure plate, the vertical pressure is converted into a horizontal thrust by the slope on the pressure-receiving part, realizing the automatic and synchronous docking of the ventilation pipe sleeve and the closed pipe sleeve to the battery air port. As the slider slides along the extension rod while overcoming the resistance of the return spring during the pushing process, it ensures the stability and precision of the connection process, and avoids seal failure caused by deviation.

[0020] At the same time, after the pressure plate releases the pressure on the upper carrier, the pressure-applying part disengages from the pressure-receiving part, and the return spring releases its elastic potential energy, driving the ventilation pipe sleeve and the closed pipe sleeve to quickly reset, realizing automatic separation. This not only improves the reliability of the air port connection and the stability of the pressurization process, but also realizes the automated operation of the detection process, improves the detection efficiency and repeatability, and is suitable for the high-efficiency airtightness detection of batch hydrogen fuel cell stacks.

[0021] 3. Through the buffer spring, the upper carrier can obtain a uniform and stable contact pressure when descending and fitting with the lower carrier, effectively preventing seal failure of the sealed cavity caused by impact or pressure fluctuation, and ensuring the stability of the sealed environment during the detection process.

[0022] On this basis, the air passage is isolated and controlled through the valve rod structure, so that each battery enters an independent sealed state after pressurization, without interference with each other, thereby realizing the individual and accurate airtightness detection of each battery, significantly improving the accuracy and reliability of the detection results, and being applicable to the efficient automatic detection of a batch of hydrogen fuel cells. Brief Description of the Drawings

[0023] Figure 1 is a schematic perspective view of a batch airtightness detection device for a hydrogen fuel cell stack according to the present invention.

[0024] Figure 2 is a schematic perspective view of a hydrogen fuel cell stack according to the present invention.

[0025] Figure 3 is a schematic perspective view of a lower carrier and a battery of a batch airtightness detection device for a hydrogen fuel cell stack according to the present invention.

[0026] Figure 4 is a schematic perspective view of a lower carrier, an upper carrier and a pressure maintaining component of a batch airtightness detection device for a hydrogen fuel cell stack according to the present invention.

[0027] Figure 5 is a plane cross-sectional view of a lower carrier, an upper carrier and a pressure maintaining component of a batch airtightness detection device for a hydrogen fuel cell stack according to the present invention.

[0028] Figure 6 is a three-dimensional structural cross-sectional view of a lower carrier, an upper carrier and a pressure maintaining component of a batch airtightness detection device for a hydrogen fuel cell stack according to the present invention.

[0029] Figure 7 is a plane cross-sectional view of an upper carrier, a lower carrier and a leakage detection structure of a batch airtightness detection device for a hydrogen fuel cell stack according to the present invention.

[0030] Figure 8 is a three-dimensional structural cross-sectional view of an upper carrier, a lower carrier and a leakage detection structure of a batch airtightness detection device for a hydrogen fuel cell stack according to the present invention.

[0031] Figure 9 is a schematic view of the state of a closed tube sleeve connecting a battery air port of a batch airtightness detection device for a hydrogen fuel cell stack according to the present invention.

[0032] Figure 10 is a schematic view of the state of a ventilation tube sleeve connecting a battery air port of a batch airtightness detection device for a hydrogen fuel cell stack according to the present invention.

[0033] Figure 11 is of the present invention Figure 5 Enlarged schematic view of part A.

[0034] The reference numerals in the figure are: 1, conveying mechanism; 2, detection mechanism; 3, battery; 31, air port; 4, lower carrier; 41, sealed cavity; 42, air duct; 421, valve rod structure; 5, upper carrier; 51, extension rod; 52, slider; 521, return spring; 6, pressure maintaining assembly; 61, pressing plate; 611, guiding rod; 6111, anti - detachment part; 612, buffer spring; 62, hydraulic rod; 7, air leakage detection structure; 71, pressure sensor; 711, compression spring; 72, pressure conducting part; 721, plate body; 7211, guide shaft; 722, airbag; 8, pressurizing structure; 81, ventilation pipe sleeve; 82, closed pipe sleeve; 83, linkage part; 831, pressed part; 832, pressing part. Detailed implementation manners

[0035] To further understand the features, technical means, specific purposes and functions achieved by the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0036] Refer to Figures 1 - 6 and Figure 11 As shown, a batch airtightness detection device for a hydrogen fuel cell stack includes a conveying mechanism 1 and a detection mechanism 2. The conveying mechanism 1 has a plurality of loading positions, and each loading position is provided with a lower carrier 4 capable of accommodating a plurality of batteries 3 at the same time. The detection mechanism 2 includes an upper carrier 5 capable of fitting with the lower carrier 4 and a pressure maintaining assembly 6 connected to the upper carrier 5. Both the lower carrier 4 and the upper carrier 5 have sealing surfaces capable of closely fitting with each other. When the upper carrier 5 and the lower carrier 4 are closed, a sealed cavity 41 for separately accommodating each battery 3 and not communicating with each other and an air duct 42 connecting the air ports 31 of adjacent batteries 3 are formed therebetween. An air leakage detection structure 7 is provided on the upper carrier 5 corresponding to each battery 3, and a pressurizing structure 8 capable of ventilating all the batteries 3 is further provided on the upper carrier 5. The pressurizing structure 8 has a ventilation pipe sleeve 81 and a closed pipe sleeve 82. The ventilation pipe sleeve 81 and the closed pipe sleeve 82 can be respectively connected to the air ports 31 of the two outermost batteries 3 among a plurality of batteries 3. The ventilation pipe sleeve 81 and the closed pipe sleeve 82 are both provided with a linkage part 83 cooperating with the pressure maintaining assembly 6. When the pressure maintaining assembly 6 drives the upper carrier 5 to fit with the lower carrier 4 and continuously applies pressure, the ventilation pipe sleeve 81 and the closed pipe sleeve 82 gradually approach the battery 3 under the drive of the linkage part 83 and are hermetically connected to the corresponding air ports 31 of the battery 3, so that all the batteries 3 form a continuous gas flow path during the unified pressurization process.

[0037] The battery 3 has an air port 31 for intake air and an air port 31 for exhaust air.

[0038] Both the ends of the downloading body 4 and the uploading body 5 that come into contact with each other are provided with sealing layers, and the surfaces where the two sealing layers contact each other are the said sealing surfaces. The sealing layers are not shown in the figure. The sealing layers are made of elastic sealing materials, such as sealing rings or rubber gaskets.

[0039] When the downloading body 4 and the uploading body 5 are closed, the sealing surfaces between them fit tightly to form the reliable sealed sealing cavity 41 and the air passage 42, so as to fill the possible tiny gaps and produce elastic deformation when being pressed, further enhancing the sealing effect.

[0040] When performing batch airtightness detection on the hydrogen fuel cell 3 stack, first, a plurality of cells 3 to be detected are sequentially placed on the downloading body 4 at the loading position of the conveying mechanism 1. Each downloading body 4 can accommodate a plurality of cells 3 simultaneously and ensure an appropriate spacing between the cells 3 for subsequent sealing and detection operations. After all the cells 3 are correctly placed, the conveying mechanism 1 transports the downloading body 4 to the working position of the detection mechanism 2. At this time, the uploading body 5 of the detection mechanism 2 is in the open state and keeps a certain distance from the downloading body 4, preparing for the next closing operation.

[0041] Subsequently, the pressure maintaining component 6 starts to work, driving the uploading body 5 to move downward to make it fit and closely contact with the downloading body 4. During this process, the air leakage detection structure 7 on the uploading body 5 aligns with the corresponding positions of each cell 3, while the ventilation pipe sleeve 81 and the closed pipe sleeve 82 respectively align with the air ports 31 of the two outermost cells 3. As the pressure maintaining component 6 continues to press down, it not only has a pressure maintaining effect on the uploading body 5, making the fit between the uploading body 5 and the downloading body 4 closer. It also prompts the linkage 83 to drive the ventilation pipe sleeve 81 and the closed pipe sleeve 82 to gradually approach the air ports 31 of the corresponding cells 3 and finally achieve sealed connection, ensuring that gas will not leak from the connection.

[0042] When the uploading body 5 and the downloading body 4 are completely fitted, a plurality of independent and non - communicating sealing cavities 41 are formed between them, and each cavity exactly accommodates one cell 3. At the same time, the air passage 42 formed after the uploading body 5 and the downloading body 4 are fitted enables the air ports 31 between adjacent cells 3 to be connected, thus constructing a continuous gas flow path during the pressurization process. The gas flow path starts from the ventilation pipe sleeve 81 in the pressurization structure 8, passes through the air ports 31 of the cells 3 connected to it, the air passage 42, the air ports 31 of other cells 3, and finally connects to the end of the closed pipe sleeve 82, forming a complete gas passage.

[0043] Next, the pressure charging phase begins. The vent sleeve 81 is connected to the air pump and compressed gas begins to be injected into the battery 3. The gas enters the air inlet 31 of the first battery 3 through the vent sleeve 81, then passes through the air passages 42 between each battery 3, and finally reaches the sealing sleeve 82. As the gas is continuously injected, the pressure inside all batteries 3 gradually rises to the set value. Once the target pressure is reached, the pressure charging stops and the pressure maintenance phase begins.

[0044] During the pressure maintenance stage, the battery 3 will maintain a constant pressure for a period of time in order to fully expose possible tiny leaks. During this period, the leakage detection structure 7 monitors the pressure changes in the sealed cavity 41 around each battery 3 in real time. If a battery 3 leaks, the pressure in the sealed cavity 41 will fluctuate abnormally due to gas infiltration. Since the pressure inside the battery 3 is much higher than the pressure in the sealed cavity 41, the resulting pressure difference will form a pressure gradient at the leak point. Gas always tends to flow from high-pressure areas to low-pressure areas, and is then captured by the corresponding leakage detection structure 7. Accurately identify tiny pressure changes and transmit data to the control system for analysis and judgment.

[0045] If no pressure anomalies are detected during the test, all batteries 3 are leak-free and meet airtightness standards. Conversely, if a pressure drop or other abnormal signal is detected at a specific point, the corresponding battery 3 has an airtightness issue and needs to be removed from the batch for further inspection and repair. The control system automatically determines the test results for each battery 3 based on the feedback data and generates a corresponding test report for the operator to review and process.

[0046] After testing is complete, the pressure-maintaining assembly 6 releases pressure, driving the upper carrier 5 upward and out of contact with the lower carrier 4. At this point, the vent sleeve 81 and the sealing sleeve 82, driven by the linkage 83, also separate from the gas port 31 of the battery 3, returning to their initial positions. Finally, the conveyor mechanism 1 transports the lower carrier 4 and the battery 3 on it away from the testing station and continues testing subsequent batteries 3.

[0047] See also Figures 4 - 10 As shown, both ends of the upper carrier 5 are provided with extension rods 51 extending horizontally outward, and each extension rod 51 is slidably provided with a slider 52 fixedly connected to the corresponding ventilation sleeve 81 and the closed sleeve 82, and the slider 52 and the pressure maintaining assembly 6 are cooperated with the linkage 83. When the lower carrier 4 moves to the inspection station, the ventilation sleeve 81 and the closed sleeve 82 are respectively in a coaxial state with the corresponding battery 3 gas port 31.

[0048] After the download body 4 moves to the detection station, the ventilation pipe sleeve 81 and the sealing pipe sleeve 82 are already coaxially aligned with the air ports 31 of the corresponding batteries 3 in the initial state. At this time, the sliders 52 on the extension rods 51 at both ends of the upper carrier 5 are in the starting position of sliding. When the pressure maintaining component 6 does not further act on the upper carrier 5, the linkage 83 remains in a relaxed state, that is, the sliders 52 are not subjected to the thrust of the linkage 83.

[0049] When the pressure maintaining component 6 is activated and continuously applies pressure to the upper carrier 5, the movement of the pressure maintaining component 6 is converted into a thrust on the slider 52 along the direction of the extension rod 51 through the linkage 83. The slider 52 slides along the extension rod 51 towards the air port 31 of the battery 3, thereby driving the ventilation pipe sleeve 81 and the sealing pipe sleeve 82 to synchronously advance towards the air port 31 of the battery 3.

[0050] Until the ventilation pipe sleeve 81 and the sealing pipe sleeve 82 are respectively tightly attached to the positions of the air ports 31 of the corresponding batteries 3. The linkage 83 ensures that while the ventilation pipe sleeve 81 and the sealing pipe sleeve 82 move with the pressure maintaining component 6, they can also achieve precise and stable approaching actions in the horizontal direction, thereby ensuring reliable and non-offset sealed connection between the ventilation pipe sleeve 81 and the sealing pipe sleeve 82 and the air ports 31 of the battery 3, and ensuring that the unified pressurization process of all batteries 3 will not leak at the air port 31 connection.

[0051] See Figures 4 - 6 、 Figure 9 and Figure 10 As shown, the linkage 83 has a pressure receiving part 831 provided on the slider 52 and a pressure applying part 832 provided on the pressure maintaining component 6. When the pressure applying part 832 acts on the pressure receiving part 831 following the downward movement of the pressure maintaining component 6, the upper carrier 5 is in a relatively static state. At this time, the slider 52 gradually approaches the upper carrier 5 under the drive of the pressure receiving part 831.

[0052] When the pressure maintaining component 6 starts to press down, the pressure applying part 832 on it moves downward accordingly, contacts the pressure receiving part 831 on the slider 52 and applies pressure. At this time, the upper carrier 5 is in contact with the download body 4 and is in a relatively static state.

[0053] As the pressure applying part 832 continuously presses down and acts on the pressure receiving part 831, the slider 52 moves along the extension rod 51 towards the upper carrier 5 under the push of the pressure receiving part 831, that is, slides towards the direction close to the air port 31 of the battery 3. The ventilation pipe sleeve 81 and the sealing pipe sleeve 82 connected to each slider 52 synchronously advance towards the corresponding air port 31 direction, gradually approach and finally fit the air port 31 of the battery 3, completing the air port 31 docking and ensuring the stability of the subsequent pressurization process.

[0054] See Figures 4 - 6 、 Figure 9 and Figure 10As shown, a return spring 521 is provided between the slider 52 and the extension rod 51. When the slider 52 gradually approaches the upper carrier 5, the return spring 521 is in a compressed state. When the pressure-applying portion 832 is separated from the pressure-receiving portion 831, the return spring 521 drives the slider 52 to a reset state, so that the vent sleeve 81 and the sealing sleeve 82 are disconnected from the corresponding gas port 31 of the battery 3.

[0055] When the pressure-applying portion 832 acts downward on the pressure-receiving portion 831 and pushes the slider 52 to move along the extension rod 51 toward the upper carrier 5, the slider 52 overcomes the elastic force of the return spring 521 and is compressed. At this time, the ventilation sleeve 81 and the closing sleeve 82 are pushed forward and establish a connection with the gas port 31 of the battery 3.

[0056] When the pressure-maintaining assembly 6 completes its downward movement and begins its return stroke, the pressure-applying portion 832 moves upward and gradually disengages from the pressure-receiving portion 831. At this point, the external force acting on the slider 52 disappears, and the return spring 521 releases its previously stored elastic potential energy, pushing the slider 52 to slide back along the extension rod 51 and return to its initial position. Simultaneously, the slider 52 returns to its original position, simultaneously moving the vent sleeve 81 and the sealing sleeve 82 away from the battery 3's gas port 31, releasing the seal between them and preparing for the next charge of the battery 3.

[0057] See also Figures 4 - 6 , Figure 9 and Figure 10 As shown, the pressure-bearing part 831 is specifically a block structure, and the pressure-applying part 832 is specifically a rod structure. The pressure-bearing part 831 has a slope extending outward from top to bottom. When the pressure-applying part 832 applies vertical pressure to the pressure-bearing part 831 along the slope, the slider 52 is gradually subjected to an inward horizontal thrust along the extension rod 51.

[0058] When the pressure-applying portion 832 contacts the slope of the pressure-receiving portion 831 , the vertical pressure is decomposed and transferred to the slope, and part of the pressure is converted into a horizontal force through the inclination angle of the slope, thereby applying an inward thrust to the slider 52 .

[0059] During this process, the slider 52 is acted upon by the horizontal thrust, overcomes the resistance of the return spring 521 , and slides along the extension rod 51 toward the upper carrier 5 , thereby pushing the vent sleeve 81 and the sealing sleeve 82 toward the gas port 31 of the battery 3 .

[0060] See also Figures 4 - 10As shown, the pressure-holding component 6 includes a pressure plate 61 and a hydraulic rod 62 for driving the movement of the pressure plate 61. A plurality of guide rods 611 vertically passing through the pressure plate 61 are provided on the upper carrier 5. The pressure plate 61 can move relative to the upper carrier 5 along the guide rods 611. A buffer spring 612 is also provided between the pressure plate 61 and the upper carrier 5. When the pressure plate 61 drives the upper carrier 5 to fit with the lower carrier 4 and continuously applies pressure, the buffer spring 612 is in a compressed state.

[0061] After the pressure plate 61 pushes the upper carrier 5 to fit with the lower carrier 4 and continues to apply pressure, the buffer spring 612 between the pressure plate 61 and the upper carrier 5 begins to be compressed, absorbing the excess impact force and maintaining a stable contact pressure.

[0062] The compression of the buffer spring 612 ensures a uniform and continuous sealed fit between the upper carrier 5 and the lower carrier 4, preventing connection loosening or seal failure caused by pressure fluctuations, and providing a stable and reliable pressure-holding environment for the detection process.

[0063] See Figures 4 - 10 As shown, an anti-disengagement portion 6111 is provided at the upper end of each guide rod 611. When the pressure plate 61 contacts the anti-disengagement portion 6111, the buffer spring 612 is in a normal state, and at the same time, the pressure-applying portion 832 and the pressure-receiving portion 831 are in a separated state.

[0064] When the pressure plate 61 moves upward under the drive of the hydraulic rod 62 to contact the anti-disengagement portion 6111, it indicates that the pressure plate 61 has risen to the set upper limit position. At this time, the buffer spring 612 is not compressed and is in a normal state of natural extension. At this time, as the pressure plate 61 continues to be lifted upward, the upper carrier 5 is driven away from the lower carrier 4.

[0065] At the same time, the pressure-applying portion 832 and the pressure-receiving portion 831 are respectively in a separated state from each other, that is, the linkage member 83 does not act, the slider 52 is in the initial position, the air pipe sleeve 81 and the closed pipe sleeve 82 do not contact the air port 31 of the battery 3, and at this time, it is in a ready state waiting for the start of detection.

[0066] See Figure 5 、 Figure 6 and Figure 11 As shown, a valve rod structure 421 is provided at the position on the upper carrier 5 corresponding to the formation of the air passage 42. When all the batteries 3 are pressurized, the air passage 42 is in a closed state under the drive of the valve rod structure 421, cutting off the gas flow path between adjacent batteries 3 and forming an independent pressure detection state.

[0067] The specific driver of the valve rod structure 421 is not shown in the figure.

[0068] When all batteries 3 are uniformly charged, the valve stem structure 421 is driven to move, inserting into the air passage 42 and sealing it. At this point, the previously connected gas flow path is severed, and the air passages 42 between each battery 3 are isolated from each other, leaving each battery 3 in an independently sealed state. This ensures that during subsequent testing, if a leak in a battery 3 occurs, it will only affect the pressure change of that battery, without affecting the test results of other batteries 3, thereby enabling accurate airtightness testing of each battery 3.

[0069] See also Figures 5 - 10 As shown, the air leakage detection structure 7 has a pressure sensor 71 and a pressure conductor 72, and a compression spring 711 is provided between the pressure conductor 72 and the pressure sensor 71. When the pressure in the sealed cavity 41 increases due to the pressure release of the battery 3, the compression spring 711 is in a compressed state under the pressure of the pressure conductor 72.

[0070] When a battery 3 leaks, gas seeps from within the battery 3 into the sealed cavity 41. Over time, the accumulation of leaked gas causes the pressure within the sealed cavity 41 to gradually increase, acting on the pressure transmitter 72. At this point, the pressure transmitter 72, driven by the gas pressure, moves toward the pressure sensor 71, compressing the compression spring 711 between the two, causing the compression spring 711 to enter a compressed state.

[0071] The compression spring 711 absorbs part of the impact force by deformation, and transmits the pressure change to the pressure sensor 71 in a stable mechanical form. The sensor converts the pressure signal into an electrical signal for analysis, thereby achieving accurate detection of the air tightness of the battery 3.

[0072] See also Figures 5 - 10 As shown, the pressure transmission member 72 has a plate body 721 movably arranged on the upper carrier 5 and an airbag 722 fixedly arranged on the upper carrier 5, the airbag 722 is located below the plate body 721, and the plate body 721 has a guide shaft 7211 that resists the compression spring 711. When the pressure in the sealed cavity 41 increases and causes the airbag 722 to expand, the plate body 721 is in a lifted state under the pressure of the airbag 722.

[0073] When the pressure within sealed cavity 41 rises due to battery 3 leakage, the gas pressure inflates airbag 722, pushing plate 721 above it upward. The expanding force of airbag 722 lifts plate 721, driving guide shaft 7211 upward simultaneously. This force compresses compression spring 711, which then compresses it. Compression spring 711 transmits the pressure from plate 721 to pressure sensor 71 with a stable elastic force, enabling precise sensing of changes in leakage pressure.

[0074] Through the synergistic effect of the pressure-holding component 6 and the linkage member 83, the ventilation pipe sleeve 81 and the closed pipe sleeve 82 can be automatically aligned with and hermetically connected to the air port 31 of the battery 3 during the downward pressing process of the upper carrier 5, improving the stability of the pressurization path and the sealing reliability. During this process, the cooperation between the slope surface of the pressure-receiving portion 831 and the pressure-applying portion 832 is used to convert the vertical pressure into a horizontal thrust, synchronously driving the slider 52 to drive the ventilation pipe sleeve 81 and the closed pipe sleeve 82 to move precisely, and realizing automatic separation after docking through the return spring 521, ensuring the automation and repeatability of the detection process.

[0075] As the pressing plate 61 presses down, the buffer spring 612 ensures that the pressure is uniform and stable when the upper carrier 5 fits with the lower carrier 4, avoiding sealing failure, and the airway 42 is cut off through the valve rod structure 421, so that each battery 3 enters an independent sealed state, realizing precise detection one by one. While improving the synchronous detection efficiency of multiple batteries 3, the detection accuracy and stability are significantly improved, meeting the requirements of large-batch and high-precision airtightness automation detection for the hydrogen fuel cell 3 stack.

[0076] The above embodiments only represent one or several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be understood as a limitation to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A batch airtightness detection device for a hydrogen fuel cell stack, comprising a conveying mechanism (1) and a detection mechanism (2). The conveying mechanism (1) has a plurality of carrying positions, and each carrying position is provided with a downloading body (4) capable of accommodating a plurality of batteries (3) simultaneously. It is characterized in that The detection mechanism (2) includes an upper carrier (5) capable of fitting with the downloading body (4) and a pressure maintaining component (6) connected to the upper carrier (5). Both the downloading body (4) and the upper carrier (5) have sealing surfaces capable of closely fitting with each other. When the upper carrier (5) and the downloading body (4) are closed, a sealed cavity (41) for separately accommodating each battery (3) and not communicating with each other and an air passage (42) connecting the air ports (31) of adjacent batteries (3) are formed between them. A leakage detection structure (7) is provided on the upper carrier (5) corresponding to each battery (3), and a pressurizing structure (8) capable of ventilating all the batteries (3) is also provided on the upper carrier (5). The pressurizing structure (8) has a ventilation pipe sleeve (81) and a closed pipe sleeve (82). The ventilation pipe sleeve (81) and the closed pipe sleeve (82) can be respectively connected to the air ports (31) of the two outermost batteries (3) among a plurality of batteries (3). Both the ventilation pipe sleeve (81) and the closed pipe sleeve (82) are provided with linkage parts (83) cooperating with the pressure maintaining component (6). When the pressure maintaining component (6) drives the upper carrier (5) to fit with the downloading body (4) and continuously applies pressure, the ventilation pipe sleeve (81) and the closed pipe sleeve (82) gradually approach the battery (3) under the drive of the linkage part (83) and are hermetically connected to the air port (31) of the corresponding battery (3), so that all the batteries (3) form a continuous gas flow path during the unified pressurization process. A valve rod structure (421) is provided at the position corresponding to the formation of the air passage (42) on the upper carrier (5).

2. The airtightness batch detection device for a hydrogen fuel cell stack according to claim 1, wherein, Extension rods (51) extending horizontally outwards are provided at both ends of the upper carrier (5). A slider (52) fixedly connecting the corresponding ventilation pipe sleeve (81) and closed pipe sleeve (82) is slidably provided on each extension rod (51). The linkage part (83) is cooperatively provided between the slider (52) and the pressure maintaining component (6). When the downloading body (4) moves to the detection station, the ventilation pipe sleeve (81) and the closed pipe sleeve (82) are respectively in a coaxial state with the air port (31) of the corresponding battery (3).

3. The airtightness batch detection device for a hydrogen fuel cell stack according to claim 2, characterized in that, The linkage part (83) has a pressure receiving part (831) provided on the slider (52) and a pressure applying part (832) provided on the pressure maintaining component (6). When the pressure applying part (832) acts on the pressure receiving part (831) following the downward pressing action of the pressure maintaining component (6), the upper carrier (5) is in a relatively static state. At this time, the slider (52) gradually approaches the upper carrier (5) under the drive of the pressure receiving part (831).

4. The batch airtightness detection device for a hydrogen fuel cell stack according to claim 3, wherein, A return spring (521) is provided between the slider (52) and the extension rod (51). When the slider (52) gradually approaches the upper carrier (5), the return spring (521) is in a compressed state. When the pressing portion (832) disengages from the pressed portion (831), the return spring (521) drives the slider (52) to be in a reset state, so that the ventilation pipe sleeve (81) and the closed pipe sleeve (82) are disengaged from the air ports (31) of the corresponding battery (3).

5. The airtightness batch detection device for a hydrogen fuel cell stack according to claim 4, characterized in that, The pressed portion (831) is specifically a block structure, and the pressing portion (832) is specifically a rod structure. The pressed portion (831) has a slope that extends obliquely outward from top to bottom. When the pressing portion (832) acts on the pressed portion (831) with the vertical pressure along the slope, the slider (52) gradually receives an inward horizontal thrust along the extension rod (51).

6. The airtightness batch detection device for a hydrogen fuel cell stack according to claim 3, characterized in that, The pressure-holding assembly (6) includes a pressure plate (61) and a hydraulic rod (62) for driving the pressure plate (61) to move. A plurality of guide rods (611) vertically passing through the pressure plate (61) are provided on the upper carrier (5). The pressure plate (61) can move relative to the upper carrier (5) along the guide rods (611). A buffer spring (612) is also provided between the pressure plate (61) and the upper carrier (5). When the pressure plate (61) drives the upper carrier (5) to be in contact with the lower carrier (4) and continuously applies pressure, the buffer spring (612) is in a compressed state.

7. An airtightness batch detection device for a hydrogen fuel cell stack according to claim 6, characterized in that, An anti-disengagement portion (6111) is provided at the upper end of each guide rod (611). When the pressure plate (61) contacts the anti-disengagement portion (6111), the buffer spring (612) is in a normal state, and at the same time, the pressing portion (832) and the pressed portion (831) are in a separated state.

8. A batch detection device for the airtightness of a hydrogen fuel cell stack according to claim 1, characterized in that, The air leakage detection structure (7) has a pressure sensor (71) and a pressure conduction member (72). A compression spring (711) is provided between the pressure conduction member (72) and the pressure sensor (71). When the pressure in the sealed cavity (41) increases due to the pressure relief of the battery (3), the compression spring (711) is in a compressed state under the pressure force received by the pressure conduction member (72).

9. The airtightness batch detection device for a hydrogen fuel cell stack according to claim 8, characterized in that, The pressure conduction member (72) has a plate body (721) movably arranged on the upper carrier (5) and an airbag (722) fixedly arranged on the upper carrier (5). The airbag (722) is located below the plate body (721). The plate body (721) has a guide shaft (7211) that abuts against the compression spring (711). When the pressure in the sealed cavity (41) increases and causes the airbag (722) to expand, the plate body (721) is in a lifted state under the pressure of the airbag (722).

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