Lithium battery packaging leakproofness detection equipment and detection method thereof

Abstract

The invention discloses lithium battery packaging leakproofness detection equipment and a detection method thereof, and relates to the technical field of lithium battery packaging leakproofness detection.The lithium battery packaging leakproofness detection equipment comprises an operation table, a battery shell and a gas inlet device used for inputting detection gas; the piston plate is arranged in the fixed cylinder in a sliding manner and is driven by air pressure; the adjusting unit is in driven connection with the piston plate and is used for simulating the sealing damage state of the battery shell; the limiting unit is in driven connection with the piston plate and is used for being matched with the adjusting unit to change the sealing state of the battery shell; the damage state of the sealing gasket is simulated through the interaction of the upper magnet and the lower magnet, the sealing performance of the lithium battery shell used for a period of time is detected, whether the dye leaks or not is observed through the cooperation of the transparent marking frame arranged on the battery shell and the fluorescent dye, and therefore the leakproofness of the battery shell is detected.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery packaging airtightness detection, and specifically provides a lithium battery packaging airtightness detection device and a detection method thereof. Background Art

[0002] A lithium battery is a battery using lithium metal or lithium alloy as the positive and negative electrode materials and a non-aqueous electrolyte solution. A lithium battery mainly consists of two major parts: a battery cell and a casing. The battery cell packaging requires placing the battery cell inside the lithium battery casing, and the casing is sealed through a sealing cover, completely isolating the inside of the lithium battery casing from the outside, so that the battery cell is in a sealed environment to ensure the electrochemical performance of the battery cell. Sealing gaskets are used when connecting the lithium battery casing and the sealing cover to ensure that the electrolyte does not leak out and the battery works normally. Existing lithium battery airtightness detection methods mostly detect the airtightness of the casing without installing the sealing gasket, and do not fully consider the potential impact of sealing gasket wear on the lithium battery airtightness during actual use.

[0003] Traditional lithium battery packaging airtightness detection devices usually adopt a detection method based on the helium leak detection principle. During the detection process, the battery casing is regarded as a closed cavity, and the cavity is provided with a liquid injection hole. The main purpose of the detection is to confirm whether there is leakage in the battery casing except for the liquid injection hole. Existing helium leak detection devices place the battery to be tested in a closed detection cavity, open the liquid injection hole, and use a vacuum pump to evacuate the detection cavity and the inside of the battery; then close the liquid injection hole, and inject helium gas into the battery through the liquid injection hole (at this time, the inside of the battery is filled with helium gas and the outside is in a vacuum state. If the battery has a leak, the helium gas will escape into the vacuum detection cavity); finally, detect the helium gas concentration in the detection cavity through a helium leak detector to determine whether the airtightness of the battery meets the standard. Although this method can detect tiny leaks, it is difficult to accurately locate the leak position for a battery with multiple leak points or a complex structure.

[0004] In view of the above problems, there is an urgent need to innovate and design on the basis of the original lithium battery packaging airtightness detection device. Summary of the Invention

[0005] The technical solution of the present invention aims at the technical problem that the existing technical solutions are too single, and provides a solution significantly different from the existing technologies. Specifically, the purpose of the present invention is to provide a lithium battery packaging airtightness detection device and a detection method thereof to solve the problems proposed in the above background art, that is, detecting the airtightness of the casing without installing the sealing gasket, not fully considering the potential impact of sealing gasket wear on the lithium battery airtightness during actual use, and although the existing detection can detect tiny leaks, it is difficult to accurately locate the leak position for a battery with multiple leak points or a complex structure.

[0006] To achieve the above object, the present invention provides the following technical solution: A lithium battery packaging airtightness detection device, including an operating table, a battery housing having upper and lower liquid injection holes, and an air intake device for inputting gas, further including a fixed cylinder for receiving the air intake of the air intake device, a piston plate slidably disposed inside the fixed cylinder and driven by air pressure, an adjustment unit driven by the piston plate to simulate the state of damaged battery housing seal, and a limit unit driven by the piston plate to cooperate with the adjustment unit to change the seal state of the battery housing; A mixing mechanism for visualizing the seal detection marker is provided between the adjustment unit and the fixed cylinder; Also included in cooperation with the mixing mechanism is a marking frame, which surrounds the joint between the sealing cover provided at the top of the battery housing and the housing opening of the battery housing.

[0007] Preferably, the lower end of the fixed cylinder is hermetically inserted into the lower liquid injection hole on the battery housing through a pipe, and one side of the piston plate is fixed with a piston rod for driving the adjustment unit.

[0008] Preferably, the adjustment unit includes a limit frame, which is fixedly connected to the upper surface of the operating table, and a driven slider is slidably limited inside the limit frame, and the driven slider is fixedly connected to the outer end of the piston rod. A pressing rod that slides through the upper end of the limit frame is attached to the upper surface of the driven slider, and one end of a connecting frame is fixed to the upper end of the pressing rod outside the limit frame, and the other end of the connecting frame is fixed with an upper magnet; An elastic telescopic rod is placed inside the battery housing, and a support frame is horizontally slidably connected to the end of the telescopic shaft of the elastic telescopic rod. A lower magnet and a sealing gasket are sequentially placed on the top of the support frame, and the surfaces of the lower magnet and the upper magnet facing each other are of the same magnetic pole.

[0009] Preferably, a first spring is provided inside the limit frame, and one end of the first spring is fixed to one side of the driven slider, and the other end of the first spring is welded to the inner wall of the limit frame; A second spring is wound around the outer wall of the pressing rod. One end of the second spring is fixed to the top end inside the limit frame, and the other end of the second spring is welded to the top of a disc fixedly connected to the outer wall of the pressing rod.

[0010] Preferably, the upper surface of the driven slider is composed of three parts: a high-level plane, an inclined plane, and a low-level plane, and a roller that rolls on the upper surface of the driven slider is rotatably installed at the lower end of the pressing rod.

[0011] Preferably, the limiting unit includes a sealed insertion tube. One end of the sealed insertion tube is fixedly communicated with the end of the fixed cylinder, and the other end of the sealed insertion tube is sealingly inserted into the liquid injection hole located at the upper position on the battery housing. A first sleeve is fixedly arranged inside the sealed insertion tube. A second sleeve is slidably connected inside the sealed insertion tube, and one end of the first sleeve is located inside the second sleeve. A plug rod is slidably connected inside the first sleeve, and a lifting plate is slidably connected inside the plug rod. Slots for limiting the plug rod are formed on the surface of the telescopic shaft of the elastic telescopic rod. A pressing plate is arranged above the sealing cover of the battery housing, and the pressing plate is fixedly connected with the operating table through an electric push rod; The lifting plate is designed in a "Z" shape. A limiting groove for limiting the lifting of the lifting plate is formed inside the first sleeve. Two inclined surfaces for cooperating with the lifting of the lifting plate are arranged at one end of the second sleeve. The "Z" - shaped lifting plate penetrates through the plug rod.

[0012] Preferably, a third spring is arranged inside the second sleeve. One end of the third spring is fixedly connected with the plug rod, and the other end of the third spring is fixedly connected with the inner wall of the second sleeve.

[0013] Preferably, the mixing mechanism includes a storage tube. The storage tube is arranged on one side of the limiting frame. The lower end of the storage tube is connected to the fixed cylinder through a pipeline in a penetrating manner. The inner bottom surface of the storage tube is rotatably connected with a third sleeve with internal threads through a bearing. A lifting rod is slidably connected to the top of the storage tube. The lower end of the lifting rod is movably connected with the third sleeve through external threads formed on its surface, and the top end of the lifting rod is fixedly connected with the bottom of the connecting frame. A rotating blade is fixedly connected to the outer wall of the third sleeve.

[0014] A method for detecting the airtightness of a lithium - battery package, the detection method comprising the following steps: S1. Place the battery housing at the detection position inside the operating table. The sealed insertion tube and the pipeline below the fixed cylinder are respectively sealingly inserted into the upper and lower liquid injection holes. Place the elastic telescopic rod and the support frame inside the battery housing. Slide the elastic telescopic rod so that its slot is engaged with the plug rod. Place the lower magnet and the sealing gasket on the top of the support frame in sequence. Cover the sealing cover of the battery housing. Drive the pressing plate to descend to the upper surface of the sealing cover through the electric push rod; S2. Gas is conveyed into the fixed cylinder through the air inlet device to drive the piston plate to move. When the piston plate moves past the pipe connecting the fixed cylinder and the battery housing, the gas enters the interior of the battery housing through the pipe. At this time, the gas inside the fixed cylinder and the storage pipe is dispersed, relieving the pressure inside. The fluorescent dye in the storage pipe also enters the interior of the battery housing through the pipe under the action of air pressure. The interior of the battery housing gradually fills with gas and fluorescent dye. At this time, due to the mutual extrusion of the pressure plate and the lower magnet, the airtightness detection is realized in the case of a sound battery housing gasket. If there is a leak in the battery housing, the fluorescent dye will fly with the leaking gas and appear on the inner wall of the transparent marking frame, and the leak point can be judged by the position of the dye. S3. The air inlet device continuously conveys gas. When the air pressure inside the battery housing is balanced with the air pressure inside the fixed cylinder, the piston plate continues to move, driving the driven slider to slide, and the push rod slides from the high-level plane to the low-level plane to move downward. The downward movement of the push rod drives the connecting frame and the upper magnet to move downward. S4. When the piston plate moves to the end connected to the sealing cannula, it pushes the second sleeve inside the sealing cannula to slide. The second sleeve drives the lifting plate to move downward in the limiting groove of the first sleeve through the two inclined planes inside it. At the same time, with the help of the "Z"-shaped structure of the lifting plate itself, it pushes the insertion rod to move backward, releasing the limit on the elastic telescopic rod. The elastic telescopic rod drives the support frame to move downward, and further releases the limit on the lower magnet. Since the upper magnet and the lower magnet repel each other with the same pole, the downward movement of the upper magnet drives the lower magnet to move downward, thereby releasing the extrusion on the gasket, realizing the airtightness detection in the state of simulating the damaged gasket. The fluorescent dye will fly with the leaking gas and appear on the inner wall of the transparent marking frame, and the leak point can be judged by the position of the dye.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. Gas is conveyed into the fixed cylinder through the air inlet device, and the air pressure is used to drive the piston plate to move inside the fixed cylinder. When the piston plate moves to one side of the sealing cannula, it pushes the second sleeve inside the sealing cannula to slide. The second sleeve drives the lifting plate to move downward in the limiting groove of the first sleeve through the two inclined planes arranged inside it. Since the lifting plate has a "Z"-shaped structure, when it moves downward, it drives the insertion rod to move backward, releasing the limit of the insertion rod on the elastic telescopic rod, enabling the elastic telescopic rod to drive the support frame to move downward, and further releasing the limit on the lower magnet. At this time, the extrusion on the gasket located between the battery housing and the lower magnet is released, thereby simulating the damaged state of the gasket and achieving the effect of detecting the sealing performance of the battery housing after being used for a period of time.

[0016] 2. The movement of the piston plate drives the driven slider to slide along a fixed path. A bevel structure is provided on the driven slider to facilitate the restoring driving force of the second spring to push the abutting rod downward, thereby driving the connecting frame to move downward synchronously. The downward movement of the connecting frame further drives the lifting rod to move downward. Since the lifting rod is threadedly connected to the third sleeve, the linear motion of the lifting rod is converted into the rotational motion of the third sleeve. The rotation of the third sleeve drives the rotary vane on its outer wall to uniformly mix the fluorescent dye in the storage tube. When the pressure inside the fixed cylinder is relieved, the fluorescent dye in the storage tube enters the inside of the battery housing under the action of air pressure. By the cooperation of the transparent marking frame fixed outside the battery housing and the fluorescent dye, it is observed whether the gas leaks, thereby detecting the airtightness of the battery housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the first three-dimensional structure of the present invention.

[0018] Figure 2 is a schematic diagram of the second three-dimensional structure of the present invention.

[0019] Figure 3 is a schematic diagram of the initial position structure of the pressing plate of the present invention.

[0020] Figure 4 is a side sectional view of the pressing plate of the present invention moved to the top of the sealing cover.

[0021] Figure 5 is a schematic diagram of the initial position structure of the piston plate of the present invention.

[0022] Figure 6 is a schematic diagram of the structure of the piston plate of the present invention in the stopped state after the first movement.

[0023] Figure 7 For the present invention Figure 6 magnified view of the structure at A.

[0024] Figure 8 is a schematic diagram of the internal structure of the sealing insertion tube of the present invention.

[0025] Figure 9 is a schematic diagram of the connection structure between the storage tube and the fixed cylinder of the present invention.

[0026] Figure 10 For the present invention Figure 9 magnified view of the structure at B.

[0027] Figure 11 is an exploded view of the internal structure of the battery housing of the present invention.

[0028] In the figure: 1, operating table; 2, battery housing; 301, fixed cylinder; 302, piston plate; 303, piston rod; 304, driven slider; 305, first spring; 4, limit frame; 501, abutting rod; 502, second spring; 503, connecting frame; 504, upper magnet; 601, sealing insertion tube; 602, first sleeve; 603, second sleeve; 604, third spring; 605, insertion rod; 606, lifting plate; 701, support frame; 702, elastic telescopic rod; 703, slot; 704, lower magnet; 801, storage tube; 802, lifting rod; 803, third sleeve; 804, rotating blade; 9, air intake device; 10, pressing plate; 11, marking frame. Specific implementation manner

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] Please refer to Figures 1 to 11 A lithium battery packaging airtightness detection device as shown, including an operating table 1, a battery housing 2 provided with two upper and lower liquid injection holes, and an air intake device 9 for inputting gas. It also includes a fixed cylinder 301 for receiving the intake air of the air intake device 9, a piston plate 302 slidably arranged inside the fixed cylinder 301 and driven by air pressure, an adjustment unit that is driven by the piston plate 302 to simulate the damaged state of the battery housing 2 in a sealed state, and a limit unit that is driven by the piston plate 302 to cooperate with the adjustment unit to change the sealed state of the battery housing 2; A mixing mechanism for visualizing the sealed detection marker is arranged between the adjustment unit and the fixed cylinder 301; A marking frame 11 is also included in cooperation with the mixing mechanism. The marking frame 11 surrounds the joint between the sealing cover provided at the top of the battery housing 2 and the opening of the battery housing 2.

[0031] In specific implementation, gas is input into the fixed cylinder 301 through the air intake device 9 to drive the piston plate 302 to slide. The piston plate 302 drives the adjustment unit through a driven connection to simulate the detection of the battery housing 2 in a sealed state, and the sealed state of the battery housing 2 is changed through the limit unit. A mixing mechanism is provided between the adjustment unit and the fixed cylinder 301 for mixing the visual sealed detection marker. The marking frame 11 surrounds the joint between the battery housing 2 and the sealing cover. By observing the distribution of the marker in the marking frame 11, the airtight performance of the battery housing 2 is judged.

[0032] As a further embodiment of the present invention, the lower end of the fixed cylinder 301 is hermetically inserted into the liquid injection hole located at the lower position on the battery housing 2 through a pipeline, and a piston rod 303 for driving the adjustment unit is fixed to one side of the piston plate 302.

[0033] In specific implementation, since the lower end of the fixed cylinder 301 is hermetically inserted into the liquid injection hole located at the lower position on the battery housing 2 through a pipeline, the piston plate 302 moves under the drive of air pressure, and drives the adjustment unit through the piston rod 303 fixed to one side thereof, thereby simulating the change of the sealing state of the battery housing 2, which is helpful for the subsequent detection of the airtight performance.

[0034] As a further embodiment of the present invention, the adjustment unit includes a limit frame 4, the limit frame 4 is fixedly connected to the upper surface of the operation table 1, and a driven slider 304 is limited and slid in the limit frame 4, and the driven slider 304 is fixedly connected to the outer end of the piston rod 303. A push rod 501 that penetrates through the upper end of the limit frame 4 in a sliding manner is attached to the upper surface of the driven slider 304, and one end of a connecting frame 503 is fixed to the upper end of the push rod 501 located outside the limit frame 4, and an upper magnet 504 is fixed to the other end of the connecting frame 503; An elastic telescopic rod 702 is placed inside the battery housing 2, and a support frame 701 is horizontally slidably connected to the end of the telescopic shaft of the elastic telescopic rod 702. A lower magnet 704 and a sealing gasket are sequentially placed on the top of the support frame 701, and the surface of the lower magnet 704 opposite to the upper magnet 504 is of the same-sex magnetic pole.

[0035] In specific implementation, the piston rod 303 drives the driven slider 304 to move, and further drives the push rod 501 to move the position of the connecting frame 503, so that the upper magnet 504 moves downward. Due to the repulsion between the same poles of the upper magnet 504 and the lower magnet 704, the lower magnet 704 moves downward synchronously, releasing the extrusion state of the sealing gasket, thereby achieving the purpose of simulating the damage of the sealing gasket through the upper magnet 504.

[0036] As a further embodiment of the present invention, a first spring 305 is arranged inside the limit frame 4, and one end of the first spring 305 is fixed to one side of the driven slider 304, and the other end of the first spring 305 is welded to the inner wall of the limit frame 4; A second spring 502 is wound around the outer wall of the push rod 501. One end of the second spring 502 is fixed to the top end inside the limit frame 4, and the other end of the second spring 502 is welded to the top of the disc fixedly connected to the outer wall of the push rod 501.

[0037] In specific implementation, the first spring 305 connects the driven slider 304 and the inner wall of the limit frame 4, which is convenient for providing a reset elastic force for the driven slider 304. The second spring 502 is wound around the outer wall of the abutting rod 501, with one end fixed to the top end of the limit frame 4 and the other end connected to the disc of the abutting rod 501. The lifting movement of the abutting rod 501 is controlled by the telescopic action of the second spring 502.

[0038] As a further embodiment of the present invention, the upper surface of the driven slider 304 is composed of a high-level plane, an inclined plane, and a low-level plane. And a roller that is in rolling fit with the upper surface of the driven slider 304 is rotatably installed at the lower end of the abutting rod 501.

[0039] In specific implementation, the upper surface of the driven slider 304 is composed of a high-level plane, an inclined plane, and a low-level plane. The abutting rod 501 is in rolling fit with the upper surface of the driven slider 304 through the roller installed at the lower end. When the driven slider 304 moves, the roller slides along the inclined plane, driving the abutting rod 501 to lift and lower, thereby adjusting the sealing state.

[0040] As a further embodiment of the present invention, the limiting unit includes a sealing insertion tube 601. One end of the sealing insertion tube 601 is fixedly communicated with the end of the fixed cylinder 301, and the other end of the sealing insertion tube 601 is sealingly inserted into the liquid injection hole located at the upper position on the battery housing 2. A first sleeve 602 is fixed inside the sealing insertion tube 601. A second sleeve 603 is slidably connected inside the sealing insertion tube 601, and one end of the first sleeve 602 is located inside the second sleeve 603. A plug rod 605 is slidably connected inside the first sleeve 602. A lifting plate 606 is slidably connected inside the plug rod 605. A slot 703 for limiting the plug rod 605 is provided on the surface of the telescopic shaft of the elastic telescopic rod 702. A pressing plate 10 is provided above the sealing cover of the battery housing 2, and the pressing plate 10 is fixedly connected to the operating table 1 through an electric push rod; The lifting plate 606 is designed in a "Z" shape. A limiting groove for limiting the lifting of the lifting plate 606 is provided inside the first sleeve 602. Two inclined planes for cooperating with the lifting of the lifting plate 606 are provided at one end of the second sleeve 603. The "Z" - shaped lifting plate 606 penetrates through the plug rod 605.

[0041] In specific implementation, one side of the sealed insertion tube 601 is hermetically inserted into the liquid injection hole located at the upper position on the battery housing 2. When the piston plate 302 inside the fixed cylinder 301 is pressed and moves to one end of the second sleeve 603 and pushes the second sleeve 603 to slide along the sealed insertion tube 601, the sliding second sleeve 603 pushes the "Z"-shaped lifting plate 606 by means of the two inclined surfaces at its end, causing the lifting plate 606 to move downward under force. At the same time, under the action of the "Z" shape of the lifting plate 606 itself, the insertion rod 605 is pulled to move inside the sealed insertion tube 601, so that the end of the insertion rod 605 is disengaged from the engagement with the slot 703, thereby releasing the limit of the insertion rod 605 on the elastic telescopic rod 702, facilitating the reset of the telescopic shaft of the elastic telescopic rod 702 to drive the support frame 701 to move downward, and further releasing the position limitation of the lower magnet 704. By virtue of the principle that like poles of the upper magnet 504 and the lower magnet 704 repel each other, during the downward movement of the upper magnet 504 along with the connecting frame 503, the lower magnet 704 is prompted to move downward synchronously, thereby releasing the extrusion of the lower magnet 704 on the sealing gasket and adjusting the sealing state of the battery housing 2. Subsequently, the electric push rod is used to push the pressing plate 10 downward to tightly press the sealing cover at the opening of the battery housing 2 to ensure the sealing performance during the detection process, thus facilitating the subsequent airtightness detection.

[0042] As a further embodiment of the present invention, a third spring 604 is arranged inside the second sleeve 603. One end of the third spring 604 is fixedly connected to the insertion rod 605, and the other end of the third spring 604 is fixedly connected to the inner wall of the second sleeve 603.

[0043] In specific implementation, the arranged third spring 604, in the initial state, facilitates the support of the insertion rod 605 and the second sleeve 603, so that the opposite ends of the insertion rod 605 and the second sleeve 603 both extend to the outside of the sealed insertion tube 601, thereby facilitating the subsequent engagement of the insertion rod 605 with the slot 703 and the pushing of the second sleeve 603 by the piston plate 302. As the piston plate 302 is pressed and moves, it gradually pushes the second sleeve 603 to move along the inside of the sealed insertion tube 601, thereby releasing the engagement of the insertion rod 605 with the slot 703 with the assistance of the lifting plate 606. After the airtightness detection of the battery housing 2 is completed and the sealing cover is removed, the stretched first spring 305 is restored to pull the piston plate 302 to move in a reset manner through the driven slider 304 and the piston rod 303. When the piston plate 302 moves to release the extrusion on the second sleeve 603, the third spring 604 is restored to push the insertion rod 605 to reset, thus facilitating the next airtightness detection of the battery housing 2.

[0044] As a further embodiment of the present invention, the mixing mechanism includes a storage tube 801. The storage tube 801 is arranged on one side of the limiting frame 4. The lower end of the storage tube 801 is connected to the fixed cylinder 301 through a pipeline in a penetrating manner. The inner bottom surface of the storage tube 801 is rotatably connected with a third sleeve 803 with internal threads through a bearing. The top of the storage tube 801 is slidably connected with a lifting rod 802. The lower end of the lifting rod 802 is movably connected with the third sleeve 803 through external threads provided on the surface. And the top end of the lifting rod 802 is fixedly connected to the bottom of the connecting frame 503. A rotating blade 804 is fixedly connected to the outer wall of the third sleeve 803.

[0045] In specific implementation, the connecting frame 503 drives the lifting rod 802 to lift and lower. The lifting rod 802 drives the third sleeve 803 to rotate through threads. The third sleeve 803 drives the rotating blade 804 to uniformly mix the detection markers in the storage tube 801. The mixed markers enter the battery case 2 through the pipeline for visualizing the airtightness detection.

[0046] A method for detecting the airtightness of a lithium battery package, the detection method comprising the following steps: S1. Place the battery case 2 at the detection position in the operation table 1. The sealing insertion tube 601 and the pipelines below the fixed cylinder 301 are respectively and hermetically inserted into the upper and lower liquid injection holes. Place the elastic telescopic rod 702 and the support frame 701 inside the battery case 2. Slide the elastic telescopic rod 702 so that its slot 703 is engaged with the insertion rod 605. Place the lower magnet 704 and the sealing gasket on the top of the support frame 701 in sequence. Cover the sealing cover of the battery case 2. Drive the pressing plate 10 to descend to the upper surface of the sealing cover through the electric push rod; S2. Convey gas into the fixed cylinder 301 through the air inlet device 9 to drive the piston plate 302 to move. When the piston plate 302 moves past the pipeline connecting the fixed cylinder 301 and the battery case 2, the gas enters the inside of the battery case 2 through the pipeline. At this time, the gas inside the fixed cylinder 301 and the storage tube 801 is dispersed and its internal pressure is relieved. The fluorescent dye in the storage tube 801 also enters the inside of the battery case 2 through the pipeline under the action of air pressure. The inside of the battery case 2 is gradually filled with gas and fluorescent dye. At this time, due to the mutual extrusion of the pressing plate 10 and the lower magnet 704, the airtightness detection of the battery case 2 in the state of a good sealing gasket is realized. If there is a leak in the battery case 2, the fluorescent dye will fly with the leaked gas to the inner wall of the transparent marking frame 11 and appear, and the leak point is judged through the position of the dye; S3. The air inlet device 9 continuously conveys gas. When the air pressure inside the battery case 2 is balanced with the air pressure inside the fixed cylinder 301, the piston plate 302 continues to move, driving the driven slider 304 to slide. The abutting rod 501 slides from the high-level plane to the low-level plane to realize downward movement. The downward movement of the abutting rod 501 drives the connecting frame 503 and the upper magnet 504 to move downward; S4. When the piston plate 302 moves to one end connected to the sealing cannula 601, it pushes the second sleeve 603 inside the sealing cannula 601 to slide. The second sleeve 603 drives the lifting plate 606 to move downward in the limiting groove of the first sleeve 602 through two inclined surfaces inside it. At the same time, with the help of the "Z"-shaped structure of the lifting plate 606 itself, it pushes the plug rod 605 to move backward, releasing the limit on the elastic telescopic rod 702. The elastic telescopic rod 702 drives the support frame 701 to move downward, and then releases the limit on the lower magnet 704. Since the upper magnet 504 and the lower magnet 704 repel each other with the same pole, the downward movement of the upper magnet 504 drives the lower magnet 704 to move downward, thereby releasing the extrusion on the sealing gasket, realizing the airtightness detection under the state of the simulated damaged sealing gasket. The fluorescent dye will fly with the leaked gas to the inner wall of the transparent marking frame 11 and appear, and the leakage point is judged by the position of the dye.

[0047] Working principle: The battery case 2 of the present invention is clearly provided with a liquid injection hole for facilitating the replenishment of electrolyte. During normal use, the gasket is located between the battery case 2 and the sealing cover. In order to simulate the airtightness detection under the damaged state of the gasket in the present invention, the gasket is arranged at the internal joint of the sealing cover and the battery case 2, and the deformation amount of the gasket is changed by changing the extrusion degree of the gasket, so as to facilitate the simulation of the damaged gasket. When using this lithium battery packaging airtightness detection device, first, the lower end of the fixed cylinder 301 is hermetically inserted into the liquid injection hole at the lower position on the battery case 2 through a pipeline, and one side of the sealing plug-in tube 601 is hermetically inserted into the liquid injection hole at the upper position on the battery case 2. Secondly, the elastic telescopic rod 702 and the support frame 701 slidably connected thereto are placed inside the battery case 2, and the slot 703 opened by the elastic telescopic rod 702 is engaged with the plug rod 605 slidably connected inside the sealing plug-in tube 601 by sliding the elastic telescopic rod 702. The lower magnet 704 and the gasket are sequentially placed on the top of the support frame 701, and the sealing cover of the battery case 2 is placed on the top of the gasket. The pressing plate 10 is driven by the electric push rod to descend to the upper surface of the sealing cover of the battery case 2 for extrusion, so as to prevent the inside of the battery case 2 from pushing the sealing cover upward due to excessive atmospheric pressure in the follow-up. The gas is conveyed into the fixed cylinder 301 through the air inlet device 9. At this time, the gas inside the fixed cylinder 301 will be conveyed into the storage tube 801 through the pipeline fixedly connected to the storage tube 801, so that the air pressure inside the fixed cylinder 301 and the storage tube 801 is the same. The purpose is that when the piston plate 302 moves past the pipeline below the fixed cylinder 301, during the process of the fixed cylinder 301 instantaneously releasing air flow into the battery case 2 through this pipeline, it is convenient to drive the fluorescent dye inside the storage tube 801 to fly into the battery case 2 (it should be noted that the air supply of the air inlet device 9 is slowly pressurized. At the moment when the pipeline opening below the fixed cylinder 301 is exposed, the air supply volume of the air inlet device 9 is less than the release volume of the pipeline opening. At this time, under the action of the instantaneous pressure difference, it is convenient for the air flow to actively drive the fluorescent dye to fly into the battery case 2. When the air supply volume of the air inlet device 9 is pressurized to exceed the release volume of the pipeline opening, the gas conveyed inside the air inlet device 9 first replenishes the air pressure inside the storage tube 801, and then will continuously be conveyed into the battery case 2 through the pipeline below the fixed cylinder 301. At the same time, it is also convenient for the fluorescent dye entering the battery case 2 to fly randomly under the influx of the air flow, so as to prepare for observing the leakage point when the gas inside the battery case 2 leaks). After the storage tube 801 is filled with air pressure, as the air inlet device 9 continuously conveys gas into the fixed cylinder 301, the piston plate 302 is driven by the air pressure to move along the inner wall of the fixed cylinder 301. While the piston plate 302 moves, the driven slider 304 is driven by the piston rod 303 to slide inside the limit frame 4, so as to stretch the first spring 305. At the same time, the high-level plane at the top of the driven slider 304 slides over the rolling surface of the roller at the lower end of the abutting rod 501.

[0048] When the piston plate 302 slides inside the fixed cylinder 301 past the pipe where the fixed cylinder 301 is connected to the battery housing 2 below, the gas stored inside the fixed cylinder 301 flows into the battery housing 2 through the pipe. At this time, the gas inside the fixed cylinder 301 is instantaneously released, and the gas stored inside the fixed cylinder 301 flows into the battery housing 2 through the pipe (the air pressure inside the fixed cylinder 301 and the storage pipe 801 remains the same), thereby relieving the pressure inside the fixed cylinder 301 and the storage pipe 801. As the air pressure flows, it drives the fluorescent dye inside the storage pipe 801 to enter the fixed cylinder 301 through the pipe. The lower end of the fixed cylinder 301 is hermetically inserted into the liquid injection hole located below on the battery housing 2 through the pipe. The battery housing 2 gradually fills with gas and fluorescent dye, and with the cooperation of the pressing plate 10 and the support frame 701, the battery housing 2 is in a tightness detection state where the gasket is not worn. If there is gas leakage in the battery housing 2 in this state, the fluorescent dye will fly and disperse onto the inner wall of the transparent marking frame 11 along with the gas leakage and become visible, thereby determining the leakage point of the battery housing 2 based on the position of the fluorescent dye.

[0049] Since the air intake device 9 has been delivering gas, when the air pressure inside the battery housing 2 is balanced with the air pressure inside the fixed cylinder 301, it will drive the piston plate 302 to continue moving. The continuous movement of the piston plate 302 drives the driven slider 304 to continue moving. As the driven slider 304 continues to move, when the inclined surface on the upper surface of the driven slider 304 passes by the roller at the lower end of the abutting rod 501, the compressed second spring 502 resumes its original state. With the restoring force of the second spring 502, it pushes the abutting rod 501 equipped with the roller to move downward to the lower flat surface on the driven slider 304 for rolling. The downward movement of the abutting rod 501 drives the connecting frame 503 to move synchronously, and further drives the upper magnet 504 fixedly connected to the connecting frame 503 to move downward. At the same time, the movement of the connecting frame 503 drives the lifting rod 802 to move downward. Since the lifting rod 802 is threadedly connected to the third sleeve 803, the downward movement of the lifting rod 802 drives the third sleeve 803 to rotate, and further drives the rotating blade 804 fixedly connected to the outer wall of the third sleeve 803 to rotate to uniformly mix the fluorescent dye inside the storage pipe 801.

[0050] When the piston plate 302 continues to move inside the fixed cylinder 301 to the side connected to the sealing insertion tube 601, the piston plate 302 first contacts one end of the second sleeve 603, and the movement of the piston plate 302 is used to push the second sleeve 603 to slide inside the sealing insertion tube 601. The sliding of the second sleeve 603 uses the inclined plane inside it to push the lifting plate 606 with a "Z" - shaped structure to move downward. During the downward movement of the lifting plate 606, the insertion rod 605 will be synchronously driven to compress the third spring 604 and move into the sealing insertion tube 601, so that the end of the insertion rod 605 is disengaged from the engagement with the slot 703, thereby releasing the limit on the elastic telescopic rod 702, and the telescopic shaft of the elastic telescopic rod 702 is reset to drive the support frame 701 to move downward, and further release the limit on the lower magnet 704. Since the upper magnet 504 and the lower magnet 704 repel each other with the same poles, the downward movement of the upper magnet 504 drives the lower magnet 704 to move downward. At this time, the extrusion on the gasket located between the battery housing 2 and the lower magnet 704 is released, thus simulating the damaged state of the gasket of the battery housing 2. If there is also gas leakage in the battery housing 2 in this state, the fluorescent dye will also fly to the inner wall of the transparent marking frame 11 along with the gas leakage and appear, so as to determine the leakage point of the battery housing 2 through the position of the fluorescent dye.

[0051] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A lithium battery encapsulation tightness detection device, comprising an operation table (1), a battery housing (2) provided with upper and lower liquid injection holes, and an air inlet device (9) for inputting gas, characterized in that: It further includes a fixed cylinder (301) for receiving the intake air of the intake device (9), a piston plate (302) slidably arranged inside the fixed cylinder (301) and driven by air pressure, an adjusting unit driven by the piston plate (302) to simulate the damaged state of the seal of the battery case (2), and a limiting unit driven by the piston plate (302) to cooperate with the adjusting unit to change the seal state of the battery case (2); A mixing mechanism for visualizing the seal detection marker is arranged between the adjusting unit and the fixed cylinder (301); Also included is a marking frame (11) cooperating with the mixing mechanism. The marking frame (11) surrounds the joint between the seal cover arranged at the top of the battery case (2) and the mouth of the battery case (2).

2. The hermeticity detection device for lithium battery packaging according to claim 1, characterized in that: The lower end of the fixed cylinder (301) is hermetically inserted into the liquid injection hole at the lower position on the battery case (2) through a pipeline. One side of the piston plate (302) is fixed with a piston rod (303) for driving the adjusting unit.

3. The hermeticity detection device for lithium battery packaging according to claim 2, characterized in that: The adjusting unit includes a limiting frame (4). The limiting frame (4) is fixedly connected to the upper surface of the operating table (1). A driven slider (304) is limited and slid inside the limiting frame (4), and the outer end of the driven slider (304) is fixedly connected to the piston rod (303). A resisting rod (501) that slidably penetrates through the upper end of the limiting frame (4) is attached to the upper surface of the driven slider (304). One end of a connecting frame (503) is fixed to the upper end of the resisting rod (501) located outside the limiting frame (4), and the other end of the connecting frame (503) is fixed with an upper magnet (504); An elastic telescopic rod (702) is placed inside the battery case (2). A support frame (701) is horizontally slidably connected to the end of the telescopic shaft of the elastic telescopic rod (702). A lower magnet (704) and a gasket are sequentially placed on the top of the support frame (701). The side of the lower magnet (704) opposite to the upper magnet (504) has the same magnetic pole.

4. A lithium battery packaging airtightness detection device according to claim 3, characterized in that: A first spring (305) is arranged inside the limiting frame (4). One end of the first spring (305) is fixed to one side of the driven slider (304), and the other end of the first spring (305) is welded to the inner wall of the limiting frame (4); A second spring (502) is wound around the outer wall of the resisting rod (501). One end of the second spring (502) is fixed to the top end inside the limiting frame (4), and the other end of the second spring (502) is welded to the top of a disc fixedly connected to the outer wall of the resisting rod (501).

5. The hermeticity detection device for lithium battery packaging according to claim 3, characterized in that: The upper surface of the driven slider (304) consists of three parts: a high-level plane, an inclined plane, and a low-level plane. A roller that is in rolling cooperation with the upper surface of the driven slider (304) is rotatably installed at the lower end of the resisting rod (501).

6. The hermeticity detection device for lithium battery packaging according to claim 3, wherein: The limiting unit includes a sealing insertion tube (601). One end of the sealing insertion tube (601) is fixedly communicated with the end of the fixed cylinder (301), and the other end of the sealing insertion tube (601) is sealingly inserted into the liquid injection hole located at the upper position on the battery case (2). A first sleeve (602) is fixed inside the sealing insertion tube (601). A second sleeve (603) is slidably connected inside the sealing insertion tube (601), and one end of the first sleeve (602) is located inside the second sleeve (603). A plug rod (605) is slidably connected inside the first sleeve (602). A lifting plate (606) is slidably connected inside the plug rod (605). A slot (703) for limiting the plug rod (605) is provided on the surface of the telescopic shaft of the elastic telescopic rod (702). A pressing plate (10) is provided above the sealing cover of the battery case (2), and the pressing plate (10) is fixedly connected to the operating table (1) through an electric push rod; The lifting plate (606) is designed in a "Z" shape. A limiting groove for limiting the lifting of the lifting plate (606) is provided inside the first sleeve (602). Two inclined surfaces for cooperating with the lifting of the lifting plate (606) are provided at one end of the second sleeve (603). The "Z" - shaped lifting plate (606) penetrates through the plug rod (605).

7. The hermeticity detection device for lithium battery packaging according to claim 6, characterized in that: A third spring (604) is provided inside the second sleeve (603). One end of the third spring (604) is fixedly connected to the plug rod (605), and the other end of the third spring (604) is fixedly connected to the inner wall of the second sleeve (603).

8. An airtightness detection device for lithium battery packaging according to claim 6, characterized in that: The mixing mechanism includes a storage tube (801). The storage tube (801) is arranged on one side of the limiting frame (4). The lower end of the storage tube (801) is connected to the fixed cylinder (301) through a pipeline in a penetrating manner. The inner bottom surface of the storage tube (801) is rotatably connected with a third sleeve (803) with internal threads through a bearing. A lifting rod (802) is slidably connected to the top of the storage tube (801). The lower end of the lifting rod (802) is movably connected to the third sleeve (803) through external threads provided on its surface, and the top end of the lifting rod (802) is fixedly connected to the bottom of the connecting frame (503). A rotating blade (804) is fixedly connected to the outer wall of the third sleeve (803).

9. A method for detecting the sealing performance of a lithium battery package, applicable to a device for detecting the sealing performance of a lithium battery package as described in claim 8, characterized in that, The detection method includes the following steps: S1. Place the battery case (2) at the detection position inside the operating table (1). The pipeline below the sealing insertion tube (601) and the fixed cylinder (301) are respectively sealingly inserted into the upper and lower liquid injection holes. Place the elastic telescopic rod (702) and the support frame (701) inside the battery case (2). Slide the elastic telescopic rod (702) to make its slot (703) engage with the plug rod (605). Place the lower magnet (704) and the sealing gasket on the top of the support frame (701) in sequence. Cover the sealing cover of the battery case (2), and drive the pressing plate (10) to descend to the upper surface of the sealing cover through the electric push rod; S2. Gas is transported into the interior of the fixed cylinder (301) through the air intake device (9) to drive the piston plate (302) to move. When the piston plate (302) moves past the pipeline connecting the fixed cylinder (301) and the battery housing (2), the gas enters the interior of the battery housing (2) through the pipeline. At this time, the gas inside the fixed cylinder (301) and the storage pipe (801) is dispersed, so the pressure inside is relieved. The fluorescent dye in the storage pipe (801) also enters the interior of the battery housing (2) through the pipeline under the action of air pressure. The interior of the battery housing (2) is gradually filled with gas and fluorescent dye. At this time, due to the mutual extrusion of the pressing plate (10) and the lower magnet (704), the airtightness detection of the battery housing (2) in the intact state of the gasket is realized. If there is a leak in the battery housing (2), the fluorescent dye will fly with the leaked gas and appear on the inner wall of the transparent marking frame (11), and the leak point is judged by the position of the dye. S3. The air intake device (9) continuously transports gas. When the air pressure inside the battery housing (2) is balanced with the air pressure inside the fixed cylinder (301), the piston plate (302) continues to move, driving the driven slider (304) to slide, and the push rod (501) slides from the high position plane to the low position plane to achieve downward movement. The downward movement of the push rod (501) drives the connecting frame (503) and the upper magnet (504) to move downward. S4. When the piston plate (302) moves to the end connected to the sealing insertion tube (601), it pushes the second sleeve (603) inside the sealing insertion tube (601) to slide. The second sleeve (603) drives the lifting plate (606) to move downward in the limiting groove of the first sleeve (602) through the two inclined surfaces inside it. At the same time, with the help of the "Z"-shaped structure of the lifting plate (606) itself, the push rod (605) is pushed backward, releasing the limit on the elastic telescopic rod (702). The elastic telescopic rod (702) drives the support frame (701) to move downward, and then releases the limit on the lower magnet (704). Since the upper magnet (504) and the lower magnet (704) repel each other with the same pole, the downward movement of the upper magnet (504) drives the lower magnet (704) to move downward, thereby releasing the extrusion of the gasket, realizing the airtightness detection in the state of simulating the damaged gasket. The fluorescent dye will fly with the leaked gas and appear on the inner wall of the transparent marking frame (11), and the leak point is judged by the position of the dye.

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