New energy automobile battery pack airtightness detection device and method

Abstract

The invention relates to the technical field of airtightness detection, in particular to a new energy automobile battery pack airtightness detection device and method.The new energy automobile battery pack airtightness detection device comprises a box body, the top of the box body is rotationally connected with a limiting shaft, the outer ring face of the limiting shaft is fixedly connected with a cover plate used for covering, and the two sides of the bottom of the cover plate are each provided with a flow guide structure used for guiding gas; a swinging structure for stirring gas is arranged in the middle of the cover plate, and a clamping structure for clamping a battery pack is arranged at the bottom of the swinging structure; the surface of the box body is covered by the cover plate, and the flow guide structure is driven to be in a bent state and guide flow to protect the battery pack, so that the battery pack is prevented from being damaged when high-pressure gas enters the battery pack, the battery pack can be prevented from being destroyed by the high-pressure gas, meanwhile, the high-pressure gas is better guided to each part of the box body, and the service life of the battery pack is prolonged. And meanwhile, the swing structure can be driven to rotate, so that high-pressure gas is effectively prevented from entering the battery pack to gather a certain part, and the subsequent detection effect on the air tightness of the battery pack is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of airtightness detection, and in particular to an airtightness detection device and method for a battery pack of a new energy vehicle. Background Art

[0002] The new energy power battery pack is the "heart" of new energy vehicles. As the core component of new energy vehicles, the safety, working stability and reliability of the power battery directly affect the performance and safety of new energy electric vehicles. In order to prevent the batteries in the battery pack from being affected by water, dust, etc., the battery pack box must be sealed.

[0003] Known application number: CN118090067A A new energy vehicle battery pack air tightness detection device, the invention is to seal and wrap the battery pack by setting a first sealing component, a second sealing component and a front baffle, and set an air guide grille in the sealing component, and set a leakage detection device on the outside of the air guide grille to detect the air pressure inside the air guide grille, and judge whether the battery pack is leaking by observing the on and off of the display light;

[0004] It can be seen that although the above patent can detect the air tightness of new energy battery packs, when high-pressure gas is injected into the battery pack before the test, the battery pack may be damaged due to the high-intensity flow of gas, or even the battery pack shell may rupture, thereby affecting the subsequent air tightness detection effect of the battery pack. In addition, when the high-pressure gas enters the battery pack, most of the gas will gather at the position where the gas enters the battery pack. If the gas gathers at the position where the gas just enters the battery pack, it may cause the battery pack to be unable to quickly cover the gas inside the battery pack, or even cause the battery pack to be over-inflated. Excessive pressure may cause physical damage to the battery pack shell, seals, connectors, etc., thereby reducing the structural strength of the battery pack and causing leakage or rupture in subsequent use. In addition, the above patent did not propose to clamp the battery pack in the process of testing the air tightness of the battery pack. If it is not clamped, the various parts of the battery pack may not fit tightly. If vibration occurs during the detection process, it will cause leakage of high-pressure gas, thereby affecting the detection effect. In view of this, we propose a new energy vehicle battery pack air tightness detection device and method. Summary of the invention

[0005] The purpose of the present invention is to provide a new energy vehicle battery pack airtightness detection device and method to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, one of the purposes of the present invention is to provide a new energy vehicle battery pack airtightness detection device, comprising a box body, the top of the box body is rotatably connected to a limit shaft, the outer ring surface of the limit shaft is fixedly connected to a cover plate for covering, both sides of the bottom of the cover plate are provided with a guide structure for guiding gas, the middle of the cover plate is provided with a swing structure for stirring the gas, and the bottom of the swing structure is provided with a clamping structure for clamping the battery pack;

[0007] When in use, the cover plate is used to cover the surface of the box body, and the flow-guiding structure is driven to be in a curved state to guide and protect the battery pack, and at the same time, the swing structure is driven to rotate to stir and fluctuate the incoming gas, and then the clamping structure is driven to clamp the battery pack;

[0008] When not in use, the cover is opened and the guide structure is driven to be parallel to stabilize the cover, while the swing structure is driven to reset, rotate, stir and quickly discharge the gas, and the clamping structure is driven to open.

[0009] Preferably, the surface of the cover plate is provided with several groups of bolts, the surface of the box body provided at the bottom of the cover plate is provided with bolt holes adapted to the bolts, air intake ducts are provided on both sides of the box body, and the surface of the cover plate is provided with a door handle for opening the cover plate.

[0010] Preferably, the guide structure includes a guide plate, which is slidably connected to the bottom of the cover plate, and a plurality of air holes for guiding air are provided on the surface of the guide plate. A sliding groove for limiting positioning is provided at the bottom of the cover plate, and a sliding block is slidably connected inside the sliding groove.

[0011] Preferably, the swing structure includes a first rack and a second rack, the first rack is fixedly connected to the sliding block, the second rack is fixedly connected to another group of sliding blocks, and both sides of the first rack and the second rack are hingedly connected to the surface of the guide plate.

[0012] Preferably, the side surfaces of the first rack and the second rack are meshingly connected to the gear, the top of the gear is rotatably connected to the cover plate, and a swing plate is fixedly connected to the side of the gear away from the bottom of the cover plate.

[0013] Preferably, the clamping structure includes a pin shaft, the pin shaft is fixedly connected to the surface of the swing plate, the bottom of the pin shaft is rotatably connected to a clamping plate, the interior of the clamping plate is hollow, and the outer side of the clamping plate is slidably connected to a tool box.

[0014] Preferably, the guide plates are made of soft material, and two groups of the guide plates are symmetrically arranged along the lateral center of the box body. The top of the guide plates is slidably connected to the box body, and the bottom of the box body is slidably connected to the sliding block.

[0015] Preferably, the teeth arranged on the side of the first rack are matched with the teeth arranged on the surface of the gear, and the swing plate fixedly connected to the bottom of the gear is rectangular.

[0016] Preferably, the pin shaft, the clamping plate and the tool box are symmetrically arranged in two groups along the transverse center of the box body, and the clamping plate slides inside the pin shaft.

[0017] The second object of the present invention is to provide a method for detecting the airtightness of a battery pack of a new energy vehicle, comprising the following steps:

[0018] Step 1: Clean the inside of the box, put the battery pack into the box, and make sure the battery pack is firmly fixed inside the box;

[0019] Step 2: Close the cover and tighten the cover to the box body, and ensure that there is no gas leakage;

[0020] Step 3: insert the high-pressure gas output pipe from the air inlet pipes arranged on both sides of the box body, and deliver the gas to the inside of the box body;

[0021] Step 4: When the cover is closed, the flow guide structure can protect the input high-pressure gas and make the swing structure rotate so that the high-pressure gas covers the inside of the box, and then the clamping structure clamps the battery pack to limit the position;

[0022] Step 5. Insert the airtightness detector from the sockets on both sides of the box and observe the value of the airtightness detector;

[0023] Step 6. Remove the screws and open the cover, then disassemble and take out the battery pack and complete the air tightness test of the battery pack.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. In the air tightness detection device for the battery pack of a new energy vehicle, the cover plate covers the surface of the box body, and drives the guide structure to be in a curved state and guide the battery pack to protect it, thereby preventing the high-pressure gas from damaging the battery pack when entering the battery pack. It can not only protect the battery pack from being destroyed by the high-pressure gas, but also better guide the high-pressure gas to various parts of the box body, and at the same time, it can drive the swing structure to rotate to stir and fluctuate the incoming gas, effectively preventing the high-pressure gas from gathering in a certain part of the battery pack after entering it, thereby improving the subsequent detection effect of the air tightness of the battery pack, and preventing the battery pack from being over-inflated.

[0026] 2. In the air tightness detection device for the battery pack of a new energy vehicle, the guide structure is bent and guides the battery pack to protect it, while driving the swing structure to rotate to stir and fluctuate the incoming gas, and then driving the clamping structure to clamp the battery pack. Clamping the battery pack can ensure that the various parts of the battery pack are tightly fitted without gaps, which can avoid gas leakage caused by tiny gaps or loose connections inside the battery pack, thereby ensuring the accuracy of subsequent air tightness detection results.

[0027] 3. In the airtightness detection device for the battery pack of a new energy vehicle, when not in use, the cover is opened and the guide structure is driven to be in a parallel state to stabilize the cover, while the swing structure is driven to reset, rotate, stir and quickly discharge the gas, and the clamping structure is driven to open, so that when the cover is opened, it is stabilized and prevented from being accidentally closed, and the gas inside the box can be quickly discharged, and the clamping structure can also be opened and placed in front of the staff, which not only facilitates the staff to subsequently install or disassemble the battery pack, but also improves work safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall assembly of the present invention;

[0029] Figure 2 It is an overall side perspective view of the present invention;

[0030] Figure 3 It is an overall cutaway stereogram of the present invention;

[0031] Figure 4 A bottom perspective view of the sliding block and the sliding groove of the present invention;

[0032] Figure 5 It is a top perspective view of the swing structure of the present invention;

[0033] Figure 6 It is a schematic diagram of the split structure of the swing structure and the clamping structure of the present invention;

[0034] Figure 7 A bottom perspective view of a first rack and a second rack of the present invention;

[0035] Figure 8 It is a schematic diagram of the overall structure of the present invention in an opened state;

[0036] Fig. 9 It is a bottom-up stereoscopic view of the overall structure of the present invention;

[0037] Fig.10 It is a schematic diagram of the two-dimensional motion state of the overall structure of the present invention.

[0038] The meaning of each number in the figure is:

[0039] 1. Cover plate; 2. Box body; 300. Guide structure; 301. Guide plate; 302. Air vent; 303. Sliding block; 304. Slide groove; 400. Swing structure; 401. First rack; 402. Gear; 403. Second rack; 404. Swing plate; 500. Clamping structure; 501. Pin; 502. Clamping plate; 503. Tool box; 6. Limiting axis. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Although the existing technology can detect the air tightness of new energy battery packs, when high-pressure gas is injected into the battery pack before the test, the battery pack may be damaged due to the high-intensity flow of gas, or even the battery pack shell may rupture, thereby affecting the subsequent air tightness detection of the battery pack. In addition, when the high-pressure gas enters the battery pack, most of the gas will gather at the position where the gas enters the battery pack. If the gas gathers at the position where the gas just enters the battery pack, it may cause the battery pack to be unable to quickly cover the gas inside the battery pack, or even cause the battery pack to be over-inflated. The excessive pressure may cause physical damage to the battery pack shell, seals, connectors, etc., thereby reducing the structural strength of the battery pack and causing leakage or rupture in subsequent use. In addition, the above patent does not propose clamping and limiting the battery pack during the process of testing the air tightness of the battery pack. If it is not clamped, the various parts of the battery pack may not fit tightly. If vibration occurs during the detection process, it will cause leakage of high-pressure gas, thereby affecting the detection effect. For Example 1 of the present invention, please refer to Figures 1 to 10 , a new energy vehicle battery pack airtightness detection device, characterized in that: it includes a box body 2, the top of the box body 2 is rotatably connected to a limit shaft 6, the outer ring surface of the limit shaft 6 is fixedly connected to cover the cover plate 1, both sides of the bottom of the cover plate 1 are provided with a guide structure 300 for guiding gas, the middle of the cover plate 1 is provided with a swing structure 400 for stirring the gas, and the bottom of the swing structure 400 is provided with a clamping structure 500 for clamping the battery pack;

[0042] When in use, the cover plate 1 covers the surface of the box body 2, and drives the flow-guiding structure 300 to be in a curved state and guide the flow to protect the battery pack, and at the same time drives the swing structure 400 to rotate to stir the incoming gas, and then drives the clamping structure 500 to clamp the battery pack;

[0043] When not in use, the cover plate 1 is opened, and the flow guiding structure 300 is driven to be parallel to stabilize the cover plate 1, and the swing structure 400 is driven to reset, rotate, stir, and quickly discharge the gas, and the clamping structure 500 is driven to open;

[0044] The present invention takes into account that when high-pressure gas is injected into the battery pack before detection, the battery pack may be damaged due to the high-intensity flow of gas, or even the battery pack shell may rupture, thereby affecting the effect of subsequent battery pack detection airtightness. In addition, when the high-pressure gas enters the battery pack, most of the gas will gather at the position where the gas enters the battery pack. If the gas gathers at the position where the gas just enters the battery pack, it may cause the battery pack to be unable to quickly cover the gas inside the battery pack, or even cause the battery pack to be over-inflated. Excessive pressure may cause physical damage to the battery pack shell, seals, connectors, etc., thereby making the structure of the battery pack strong. The degree of the gasket 2 decreases, and leakage or rupture may occur in subsequent use. Therefore, the cover plate 1 covers the surface of the box body 2, and drives the guide structure 300 to be in a curved state and guide the battery pack to protect it, thereby preventing the high-pressure gas from damaging the battery pack when entering the battery pack. It can not only protect the battery pack from being destroyed by the high-pressure gas, but also better guide the high-pressure gas to various parts of the box body 2. In addition, the swing structure 400 can be driven to rotate at the same time to stir and fluctuate the incoming gas, effectively preventing the high-pressure gas from gathering in a certain part of the battery pack after entering it, thereby improving the subsequent detection effect of the air tightness of the battery pack, and preventing the battery pack from being over-inflated.

[0045] Furthermore, in the process of testing the air tightness of the battery pack, no clamping limit is proposed. If it is not clamped, the various parts of the battery pack may not fit tightly. If vibration occurs during the testing process, it will cause leakage of high-pressure gas, thereby affecting the testing effect. Therefore, the flow guide structure 300 is bent and guides the battery pack to protect it, and at the same time drives the swing structure 400 to rotate to stir the incoming gas, and then drives the clamping structure 500 to clamp the battery pack. Clamping the battery pack can ensure that the various parts of the battery pack fit tightly without gaps, so as to avoid gas leakage caused by tiny gaps or loose connections inside the battery pack, thereby ensuring the accuracy of the subsequent air tightness test results;

[0046] Next, considering the existing situation, when installing or replacing the battery later, it is necessary to constantly change the tools or forget to take the tools. Therefore, when not in use, by opening the cover plate 1, driving the guide structure 300 to be in a parallel state to stabilize the cover plate 1, and driving the swing structure 400 to reset, rotate, stir and quickly discharge the gas, and drive the clamping structure 500 to open, so as to achieve that when the cover plate 1 is opened, it is stabilized and prevented from being accidentally closed, and the gas inside the box body 2 can be quickly discharged, and the clamping structure 500 can also be opened and placed in front of the staff, which is not only convenient for the staff to install or disassemble the battery pack later, but also improves work safety;

[0047] In order to inject high pressure gas into the box 2 and open the box 2, the following specific structure needs to be disclosed in detail. Please refer to Figures 1 to 3 , a plurality of groups of bolts are arranged on the surface of the cover plate 1, bolt holes adapted to the bolts are arranged on the surface of the box body 2 arranged at the bottom of the cover plate 1, air intake ducts are arranged on both sides of the box body 2, and a door handle for opening the cover plate 1 is arranged on the surface of the cover plate 1;

[0048] First, before the air tightness test of the battery pack, the staff needs to confirm that there is no dust inside the box 2, and then put the battery pack into the box 2 and fix the battery pack, and then press the cover 1 to close the box 2, and then manually tighten the bolts by the staff to fix the cover 1 and the box 2 to reduce air leakage, and then the staff will connect the high-pressure gas output pipe with the air intake pipes set on both sides of the box 2, and pour the high-pressure gas into the box 2, so as to inject high-pressure gas into the box 2, and at the same time reduce the gap between the cover 1 and the box 2 after merging, so as to improve the subsequent air tightness test of the battery pack;

[0049] In order to guide the incoming high-pressure gas, the following specific structures need to be disclosed in detail, please refer to Figures 3 to 5 The guide structure 300 includes a guide plate 301, which is slidably connected to the bottom of the cover plate 1. The surface of the guide plate 301 is provided with a plurality of air holes 302 for guiding air. The bottom of the cover plate 1 is provided with a slide groove 304 for limiting position. A sliding block 303 is slidably connected inside the slide groove 304.

[0050] When the cover plate 1 is pressed to close the box body 2, the cover plate 1 will drive the guide plate 301 to move synchronously and be placed inside the box body 2. At that time, because the guide plate 301 is made of soft material and is larger than the width of the box body 2, the guide plate 301 will contact the box body 2 during the movement and drive the guide plate 301 to bend, so that when the subsequent intake pipe enters the high-pressure gas, the gas contacts and guides the bent guide plate 301, and the high-pressure gas is also discharged into the box body 2 from the air vents 302 opened on the surface of the guide plate 301. The guide plate 301 is set as a soft material, so it can also buffer the entering high-pressure gas, effectively preventing the battery pack from being damaged by the impact of the high-pressure gas;

[0051] In order to achieve the stirring of the incoming gas by the swinging of the swinging structure 400, the following specific structure needs to be disclosed in detail, please refer to Figures 3 to 7 The swing structure 400 includes a first rack 401 and a second rack 403. The first rack 401 is fixedly connected to the sliding block 303, and the second rack 403 is fixedly connected to another set of sliding blocks 303. Both sides of the first rack 401 and the second rack 403 are hingedly connected to the surface of the guide plate 301.

[0052] When the guide plate 301 is bent, the high-pressure gas will enter the interior of the box body 2 from the air vent 302, and the guide plate 301 will drive the first rack 401 and the second rack 403 to move towards each other when it is bent. At that time, because the tops of the first rack 401 and the second rack 403 are fixedly connected to the sliding block 303, when the first rack 401 and the second rack 403 are bent and driven by the guide plate 301, the first rack 401 and the second rack 403 will synchronously drive the sliding block 303 to slide inside the slide groove 304, which can not only limit the first rack 401 and the second rack 403, but also move the first rack 401 and the second rack 403 inside the box body 2, so that the high-pressure gas inside the box body 2 is moved by the first rack 401 and the second rack 403, and the high-pressure gas is activated, which helps to evenly distribute the high-pressure gas to cover the interior of the box body 2 and improve the subsequent air tightness detection of the battery pack;

[0053] In order to achieve the subsequent clamping and limiting of the battery pack, the following specific structure needs to be disclosed in detail, please refer to Figures 1 to 7 The sides of the first rack 401 and the second rack 403 are meshed with the gear 402, the top of the gear 402 is rotatably connected to the cover plate 1, and the side of the gear 402 away from the bottom of the cover plate 1 is fixedly connected with a swing plate 404;

[0054] When the first rack 401 and the second rack 403 move toward each other, they will mesh and drive the gear 402 to rotate. The rotation of the gear 402 will drive the swing plate 404 to rotate around the center of the gear 402, so as to achieve the subsequent clamping and limiting of the clamping structure 500 battery pack, thereby ensuring the accuracy of the subsequent airtightness test;

[0055] In order to achieve clamping and limiting before testing the air tightness of the battery pack, the following specific structure needs to be disclosed in detail, please refer to Figures 1 to 7 The clamping structure 500 includes a pin 501, which is fixedly connected to the surface of the swing plate 404. The bottom of the pin 501 is rotatably connected to a clamping plate 502. The inside of the clamping plate 502 is hollow, and the outside of the clamping plate 502 is slidably connected to a tool box 503.

[0056] When the swing plate 404 rotates around the center of the gear 402, the two groups of clamping plates 502 are driven to move closer to each other until the inner sides of the two groups of clamping plates 502 are in contact with the battery pack, thereby clamping and limiting the battery pack. The clamping and limiting can ensure that the battery pack will not be displaced or deformed during the detection process, thereby ensuring the accuracy of the detection result;

[0057] After clamping the battery pack, the staff will pull out the high-pressure gas output pipe and the air intake pipes set on both sides of the box body 2, and block the air intake pipes set on both sides of the box body 2 to ensure that there is no gas leakage. Then, the staff will insert the air tightness tester into the sockets set on both sides of the box body 2 to realize the air tightness test of the battery pack;

[0058] In order to facilitate the disassembly of the battery pack, the following specific structure needs to be disclosed in detail: the guide plate 301 is made of soft material, and two groups of guide plates 301 are symmetrically arranged along the transverse center of the box body 2. The top of the guide plate 301 is slidably connected to the box body 2, and the bottom of the box body 2 is slidably connected to the sliding block 303;

[0059] After the air tightness test of the battery pack, the staff needs to manually remove the tightened bolts, and then manually pull the door handle and rotate the cover 1 around the limit axis 6 to open the cover 1. After the cover 1 is opened, the guide plate 301 will lose its elasticity and return to a parallel state. At this time, the guide plate 301 will be larger than the vertical diameter of the box body 2, so that the cover 1 can be supported. For details, please refer to Figure 8 , so that it is convenient for staff to disassemble the battery pack;

[0060] In order to quickly discharge the high-pressure gas inside the battery pack after detection, the following specific structure needs to be disclosed in detail: the teeth arranged on the side of the first rack 401 and the teeth arranged on the surface of the gear 402 are adapted to each other, and the swing plate 404 fixedly connected to the bottom of the gear 402 is rectangular;

[0061] When the guide plate 301 recovers from the bent state to the parallel state, it drives the first rack 401 and the second rack 403 to move away from each other, and drives the gear 402 to reverse, and then drives the swing plate 404 to be parallel. When the swing plate 404 rotates and resets, the high-pressure gas injected into the box body 2 is driven to be discharged quickly, thereby improving the service life of the battery pack;

[0062] In order to facilitate the staff to take the tools, the following specific structure needs to be disclosed in detail. The pin shaft 501, the clamping plate 502 and the tool box 503 are symmetrically arranged in two groups along the transverse center of the box body 2, and the clamping plate 502 slides inside the pin shaft 501;

[0063] When the cover 1 is opened, the swing structure 400 and the clamping structure 500 are driven to be arranged in an oblique shape. For details, please refer to Figure 8 , so that the entire structure of the clamping structure 500 is placed in front of the staff, and then the staff can open the pin 501 to facilitate the tool to be taken, thereby improving the effect of disassembling the battery pack;

[0064] Embodiment 2 of the present invention: Step 1, clean the interior of the box 2, put the battery pack into the box 2, and ensure that the battery pack is fastened inside the box 2;

[0065] Step 2: Close the cover plate 1 and tighten the cover plate 1 and the box body 2 by threads, and ensure that there is no gas leakage from the external leakage port;

[0066] Step 3: insert the high-pressure gas output pipe from the air inlet pipes arranged on both sides of the box body 2, and transport the gas into the box body 2;

[0067] Step 4: When the cover plate 1 is closed, the flow guide structure 300 can protect the input high-pressure gas and make the swing structure 400 rotate so that the high-pressure gas covers the inside of the box body 2, and then make the clamping structure 500 clamp the battery pack to limit the position;

[0068] Step 5: Insert the airtightness detector from the sockets provided on both sides of the box 2, and observe the value of the airtightness detector;

[0069] Step 6. Remove the screws and open the cover 1, then disassemble and take out the battery pack, and complete the air tightness test of the battery pack.

[0070] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. New energy vehicle battery pack airtightness detection device, characterized by: The invention comprises a box body (2), the top of the box body (2) is rotatably connected to a limiting shaft (6), the outer ring surface of the limiting shaft (6) is fixedly connected to a cover plate (1), both sides of the bottom of the cover plate (1) are provided with a flow guiding structure (300) for guiding gas, the middle of the cover plate (1) is provided with a swing structure (400) for stirring gas, and the bottom of the swing structure (400) is provided with a clamping structure (500) for clamping a battery pack; When in use, the cover plate (1) covers the surface of the box body (2), and drives the flow-guiding structure (300) to be in a curved state and guide the flow to protect the battery pack, while driving the swing structure (400) to rotate to stir the incoming gas, and then drives the clamping structure (500) to clamp the battery pack; When not in use, the cover plate (1) is opened and the flow-guiding structure (300) is driven to be in a parallel state to stabilize the cover plate (1), while the swing structure (400) is driven to return to its original position to rotate and stir to quickly discharge gas, and the clamping structure (500) is driven to open.

2. The new energy vehicle battery pack airtightness detection device according to claim 1 is characterized in that: The surface of the cover plate (1) is provided with a plurality of groups of bolts, the surface of the box body (2) arranged at the bottom of the cover plate (1) is provided with bolt holes adapted to the bolts, the left and right sides of the box body (2) are provided with air intake ducts, and the surface of the cover plate (1) is provided with a door handle for opening the cover plate (1).

3. The new energy vehicle battery pack airtightness detection device according to claim 1, characterized in that: The guide structure (300) comprises a guide plate (301), the guide plate (301) is slidably connected to the bottom of the cover plate (1), a plurality of air holes (302) for guiding air are provided on the surface of the guide plate (301), a slide groove (304) for limiting position is provided at the bottom of the cover plate (1), and a sliding block (303) is slidably connected inside the slide groove (304).

4. The new energy vehicle battery pack airtightness detection device according to claim 1, characterized in that: The swing structure (400) comprises a first rack (401) and a second rack (403); the first rack (401) is fixedly connected to the sliding block (303); the second rack (403) is fixedly connected to another group of sliding blocks (303); and both sides of the first rack (401) and the second rack (403) are hingedly connected to the surface of the guide plate (301).

5. The new energy vehicle battery pack airtightness detection device according to claim 4, characterized in that: The side surfaces of the first rack (401) and the second rack (403) are meshingly connected to the gear (402), the top of the gear (402) is rotatably connected to the cover plate (1), and a swing plate (404) is fixedly connected to the side of the gear (402) away from the bottom of the cover plate (1).

6. The new energy vehicle battery pack airtightness detection device according to claim 1, characterized in that: The clamping structure (500) includes a pin shaft (501), the pin shaft (501) is fixedly connected to the surface of the swing plate (404), the bottom of the pin shaft (501) is rotatably connected to a clamping plate (502), the interior of the clamping plate (502) is hollow, and the outer side of the clamping plate (502) is slidably connected to a tool box (503).

7. The new energy vehicle battery pack airtightness detection device according to claim 3 is characterized in that: The guide plates (301) are made of soft material. Two groups of guide plates (301) are symmetrically arranged along the transverse center of the box body (2). The top of the guide plates (301) is slidably connected to the box body (2), and the bottom of the box body (2) is slidably connected to the sliding block (303).

8. The new energy vehicle battery pack airtightness detection device according to claim 4, characterized in that: The teeth arranged on the side of the first rack (401) are adapted to the teeth arranged on the surface of the gear (402), and the swing plate (404) fixedly connected to the bottom of the gear (402) is arranged in a rectangular shape.

9. The new energy vehicle battery pack airtightness detection device according to claim 6, characterized in that: The pin shaft (501), the clamping plate (502) and the tool box (503) are symmetrically arranged in two groups along the transverse center of the box body (2), and the clamping plate (502) slides inside the pin shaft (501).

10. A method for detecting air tightness of a battery pack of a new energy vehicle, applied to the air tightness detection device for a battery pack of a new energy vehicle as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: clean the inside of the box (2), place the battery pack into the box (2), and ensure that the battery pack is firmly fixed inside the box (2); Step 2: Close the cover plate (1), and tighten the cover plate (1) and the box body (2) by screw threads, and ensure that there is no gas leakage from the external leakage port; Step 3: inserting the high-pressure gas output pipe from the air inlet pipes provided on both sides of the box body (2) and delivering the gas to the inside of the box body (2); Step 4: When the cover plate (1) is closed, the flow guide structure (300) can protect the input high-pressure gas and make the swing structure (400) rotate so that the high-pressure gas covers the inside of the box (2), and then make the clamping structure (500) clamp the battery pack to limit the position; Step 5: Insert the airtightness detector from the sockets provided on both sides of the box (2) and observe the value of the airtightness detector; Step 6: Remove the screws and open the cover (1), then remove the battery pack and complete the air tightness test of the battery pack.

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