Lithium battery explosion-proof test box

Abstract

The invention relates to the technical field of lithium battery detection equipment, and discloses a lithium battery explosion-proof test box which is used for solving the problems that a box door deforms due to explosion impact of a lithium battery, and chippings in the box body are difficult to clean. A buffer plate is arranged in a mounting groove of the box body, a plurality of closed grooves are formed in the edge of the box door, and a supporting block is arranged in a sliding groove in the edge of the box door; when the exploded lithium battery generates smoke and impact force, the impact of scraps is relieved through the buffer plate, and the edge of the box door is locked by inserting the supporting block into the closed groove, so that the edge of the box door is prevented from tilting; by arranging the slidable cleaning block on the buffer plate, when the lithium battery explodes, the buffer plate extrudes gas in the mounting groove to store energy, and when the box door is opened, gas in the gas collecting groove pushes the cleaning block to move, so that chippings on the upper end face of the buffer plate are collected, and experimenters can conveniently sweep the chippings to the chipping collecting groove.

Description

Technical Field

[0001] The present application relates to the technical field of lithium battery testing equipment, and in particular to an explosion-proof test box for lithium batteries. Background Art

[0002] Lithium battery is a common rechargeable battery that uses lithium metal or lithium compounds as the positive electrode material and usually uses carbon materials as the negative electrode material. Lithium batteries are widely used in various electronic devices, power tools, electric vehicles, etc. Due to the high energy density and fast charge and discharge capabilities of lithium batteries, improper use or storage conditions may cause overheating, short circuit, electrolyte leakage and other problems, which may lead to explosions or fires. In order to ensure the safety performance and stability of lithium batteries, lithium battery manufacturers and related industries usually use lithium battery explosion-proof test boxes for testing and evaluation.

[0003] The lithium battery explosion-proof test box is specially used to simulate the situations that lithium batteries may encounter under abnormal conditions, such as overcharging, over-discharging, high temperature, short circuit, etc., in order to evaluate the safety performance of lithium batteries. Since the door of the lithium battery explosion-proof test box is installed on the box body through hinges and locking devices, and the installation points are only on both sides of the door, when the lithium battery is tested in the lithium battery explosion-proof test box, the large impact force generated by the lithium battery explosion will act on the door of the box, and the edge of the door will be lifted under the action of the impact force. After multiple actions, the deformed door will cause the lithium battery explosion-proof test box to be poorly sealed and leak harmful gases; and after the lithium battery explodes, the lithium battery debris will be scattered throughout the box. Due to the deep box, it is difficult for the experimenter to clean up the debris. Summary of the invention

[0004] The present application proposes a lithium battery explosion-proof test box, which has the advantages of preventing the box door from being deformed by impact force and facilitating the cleaning of lithium battery debris inside the box. It is used to solve the problem that the box door is deformed by the impact of lithium battery explosion and the debris inside the box is difficult to clean.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: a lithium battery explosion-proof test box, comprising a base, a box body and a box door, a purification port for exhausting gas is provided on the rear side of the box body, and mounting grooves are provided on the four side walls of the box body, a buffer plate and a support spring are provided in the mounting groove, the buffer plate is slidingly and sealably installed in the mounting groove, and the mounting groove is filled with gas; the support spring is fixedly installed in the mounting groove, and the two ends of the support spring are respectively fixedly connected to the buffer plate and the bottom end of the mounting groove; a plurality of slide grooves are provided on the side wall of the box body close to the box door, a support block is slidingly and sealably installed in the slide groove, and the bottom end of the slide groove is connected with the bottom end of the mounting groove through a connecting hole I; a plurality of closed grooves are provided on the side wall of the box door close to the box body, and the positions of the closed grooves and the slide grooves correspond one to one.

[0006] Furthermore, the length of the support block is smaller than the length of the slide slot.

[0007] Furthermore, a limiting block is fixedly installed on one side of the bottom end of the slide groove to prevent the supporting block from blocking the connecting hole I.

[0008] Furthermore, a connecting hole II for connecting the top of the slide groove and the bottom of the installation groove is opened on the inner wall at the lower end of the box body, and the support block is located in the slide groove between the connecting holes I and II; an air collecting groove, a connecting groove and a telescopic tube are provided at the bottom end of the rear wall of the box body, and the air collecting groove is connected to the installation groove through a one-way valve; the connecting groove is close to the upper side of the air collecting groove, and a blocking block is installed in the connecting groove for sliding sealing, and a return spring is provided in the connecting groove, and the two ends of the return spring are respectively fixedly connected to the blocking block and the inner wall of the connecting groove; the telescopic tube is embedded in the box body close to the upper side of the connecting groove, and the side of the telescopic tube An air outlet is provided at one end of the wall; two through holes are provided on the side wall where the reset spring of the connecting groove is installed, and the two through holes are respectively connected to the air collecting groove and the telescopic tube; a power rod is movably installed in the buffer plate, and the power rod passes through the buffer plate, one end of the power rod is close to the blocking block, and the other end of the power rod is close to the inner wall of the box door, and a cleaning block that can slide relative to the buffer plate is installed on the upper surface of the buffer plate at the lower end, and permanent magnet blocks are fixedly installed on the opposite end surfaces of the cleaning block and the telescopic tube; a chip collecting groove is fixedly installed on the side wall of the box body, and the chip collecting groove is close to the lower end of the box door.

[0009] Furthermore, the flow direction of the one-way valve is from the installation groove to the air collecting groove.

[0010] Furthermore, when the door is not closed, the support spring and the return spring are both in a normal state, and when the door is closed, the return spring is in a compressed state.

[0011] Furthermore, the permanent magnet block on the end surface of the cleaning block and the permanent magnet block on the end surface of the telescopic tube generate a force of attraction.

[0012] Furthermore, the support spring and the return spring are high temperature resistant springs, and the permanent magnet block is a high temperature resistant permanent magnet.

[0013] This application has the following beneficial effects:

[0014] 1. The present application provides a lithium battery explosion-proof test box, which is provided with a mounting groove in the box body, a buffer plate and a support spring in the mounting groove, a plurality of closed grooves at the edge of the box door, a slide groove is provided on the box body at the edge of the box door, the slide groove is connected with the mounting groove, a support block is provided in the slide groove, and the support block is adapted to the closed groove. During operation, the lithium battery explodes, and the exploded lithium battery generates a large impact force, thereby pushing the buffer plate to slide into the mounting groove, thereby generating a certain buffer for the explosion debris and reducing the damage of the explosion debris to the inner wall of the box body; at the same time, the gas in the mounting groove enters the slide groove, so that the support block is inserted into the closed groove. When the impact force acts on the box door, the edge position of the box door is locked by the support block, and the impact force generated by the explosion acts on the support block, thereby preventing the edge of the box door from warping, thereby avoiding the phenomenon of poor sealing effect between the box door and the box body.

[0015] 2. The present application provides a lithium battery explosion-proof test box. When the lithium battery explodes to generate gas and impact force, the box is in a high-pressure state. At this time, the support block is always in a closed groove, and the box door is stuck by the support block, making it difficult to open. After the gas in the box is discharged through the purification port, when the pressure in the box reaches a safe pressure, the buffer plate is reset under the action of the elastic force of the support spring, and negative pressure is generated in the installation groove to reset the support block, thereby achieving an unlocking effect, avoiding the box door being opened when the box is under high pressure, the high-pressure gas causing the box door to pop out, and the box door hitting the experimenter.

[0016] 3. The present application provides a lithium battery explosion-proof test box, which has an air collecting groove at the lower position of the rear wall of the box body, the air collecting groove is connected with the installation groove through a one-way valve, the air collecting groove is connected with the telescopic tube through a connecting groove, a blocking block is slidably installed in the connecting groove, a power rod is provided in the lower buffer plate, one end of the power rod supports the blocking block, and a slidable cleaning block is provided on the lower buffer plate. When the box door is closed, the box door supports the power rod, so that the power rod pushes the blocking block to slide into the connecting groove, thereby blocking the through hole of the connecting groove. When the lithium battery explodes The impact force generated by the explosion pushes the buffer plate to move, so that the gas in the lower installation groove enters the gas collecting groove through the one-way valve for storage, and the pressure is released in the box. When the box door is opened, the block and the power rod are reset under the action of the reset spring, and the gas collecting groove is connected with the telescopic tube through the connecting groove. The gas in the gas collecting groove quickly enters the telescopic tube, and the telescopic tube extends, thereby pushing the cleaning block to slide toward the box door. The cleaning block pushes the debris on the lower buffer plate to the box door. The experimenter only needs to sweep the debris into the chip collecting groove, which is convenient for the experimenter to clean. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute a part of the specification, illustrate embodiments disclosed in the present application and, together with the description, serve to explain the principles disclosed in the present application.

[0018] The present application can be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0019] Figure 1 It is a schematic diagram of the structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the internal structure of the box of the present invention;

[0021] Figure 3 For the present invention Figure 2 Sectional view at AA;

[0022] Figure 4 For the present invention Figure 3 A magnified view of the local structure at B in the middle;

[0023] Figure 5 For the present invention Figure 3 A magnified view of the local structure at C in the middle;

[0024] Figure 6 For the present invention Figure 5 Enlarged view of the local structure at point D in the middle.

[0025] In the figure: 1. base; 2. box body; 201. purification port; 202. mounting groove; 203. buffer plate; 204. support spring; 205. slide groove; 206. support block; 207. connecting hole I; 208. connecting hole II; 209. air collecting groove; 210. one-way valve; 211. connecting groove; 212. blocking block; 213. power rod; 214. telescopic tube; 215. air outlet; 216. cleaning block; 217. permanent magnet block; 218. reset spring; 3. box door; 301. sealing strip; 302. closing groove; 4. chip collecting groove. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0027] See also Figure 1 , Figure 2 and Figure 3A lithium battery explosion-proof test box includes a base 1, a box body 2 and a box door 3. The box body 2 is fixedly installed on the top of the base 1, one side of the box door 3 is movably installed on the box body 2 through a hinge, and a locking device is fixedly installed on the other side of the box door 3. A sealing strip 301 for sealing is fixedly installed on the side wall of the box door 3. A chip collecting groove 4 is fixedly installed on the side wall of the box body 2. The chip collecting groove 4 is close to the lower end of the box door 3. The length of the chip collecting groove 4 is greater than the width of the box door 3. A purification port 201 for exhausting gas is opened on the rear side of the box body 2.

[0028] See also Figure 2 and Figure 3 The four side walls of the box body 2 are provided with mounting grooves 202, and a buffer plate 203 is slidingly sealed and installed in the mounting grooves 202. The mounting grooves 202 are filled with gas. A plurality of supporting springs 204 are fixedly installed at the bottom end of the mounting grooves 202, and one end of the supporting spring 204 is fixedly installed on the buffer plate 203.

[0029] See also Figure 2 , Figure 3 and Figure 4 A plurality of slide grooves 205 are provided on the side wall of the box body 2 close to the box door 3, and a support block 206 is installed in the slide groove 205 in a sliding seal. The length of the support block 206 is less than the length of the slide groove 205. The bottom end of the slide groove 205 is connected with the bottom end of the installation groove 202 through a connecting hole Ⅰ207. A limiting block for preventing the support block 206 from blocking the connecting hole Ⅰ207 is fixedly installed on one side of the bottom end of the slide groove 205. A plurality of closed grooves 302 are provided on the side wall of the box door 3 close to the box body 2, and the positions of the closed grooves 302 and the slide grooves 205 correspond one to one.

[0030] See also Figure 3 , Figure 4 , Figure 5 and Figure 6A connecting hole II 208 for connecting the top of the slide groove 205 and the bottom of the installation groove 202 is provided on the inner wall of the lower end of the box body 2, and the support block 206 is located in the slide groove 205 between the connecting hole I 207 and the connecting hole II 208. A gas collecting groove 209 is provided at the bottom end of the rear wall of the box body 2, and the gas collecting groove 209 is connected with the installation groove 202 through a one-way valve 210. A connecting groove 211 is provided in the box body 2 close to the upper side of the gas collecting groove 209, and a blocking block 212 is installed in the connecting groove 211 for sliding sealing. A return spring 218 is provided in the connecting groove 211, and one end of the return spring 218 is fixedly connected to the blocking block 212, and the other end of the return spring 218 is fixedly installed on the side wall of the connecting groove 211. A through hole connected to the gas collecting groove 209 is provided on the side wall of the connecting groove 211 where the return spring 218 is installed, and a buffer plate 203 is movably installed in There is a power rod 213, which passes through the buffer plate 203. One end of the power rod 213 is close to the blocking block 212, and the other end of the power rod 213 is close to the inner wall of the box door 3. A telescopic tube 214 is embedded and installed in the box body 2 close to the upper side of the connecting groove 211. The telescopic tube 214 can be extended axially when inflated. The telescopic tube 214 is located in the inner wall of the box body 2 when not inflated. A through hole connected to the telescopic tube 214 is provided on the side wall of the connecting groove 211 where the reset spring 218 is installed. An air outlet 215 for air outlet is provided at one end of the side wall of the telescopic tube 214. The air outlet 215 is a small hole with a slow air outlet speed. A cleaning block 216 that can slide relative to the buffer plate 203 is installed on the upper end surface of the buffer plate 203 at the lower end, and permanent magnet blocks 217 are fixedly installed on the opposite end surfaces of the cleaning block 216 and the telescopic tube 214.

[0031] The flow direction of the one-way valve 210 is from the installation groove 202 to the gas collecting groove 209. When the gas in the installation groove 202 is squeezed by the buffer plate 203, the gas in the installation groove 202 can enter the gas collecting groove 209 through the one-way valve 210, so that the gas is stored in the gas collecting groove 209, and the gas in the gas collecting groove 209 is prevented from flowing back.

[0032] When the door 3 is not closed, the support spring 204 and the return spring 218 are both in a normal state. When the door 3 is closed, the return spring 218 is in a compressed state. When the door 3 is not closed, the support spring 204 only provides a force to support the buffer plate 203, and the return spring 218 limits the block 212, so that the gas collecting groove 209, the connecting groove 211 and the telescopic tube 214 are in a connected state; when the door 3 is closed, the return spring 218 is compressed by the block 212, and the block 212 blocks the through hole. At the same time, the compressed return spring 218 provides power for the block 212 to reset.

[0033] The permanent magnet block 217 on the end face of the cleaning block 216 and the permanent magnet block 217 on the end face of the telescopic tube 214 generate a force of attraction. When the telescopic tube 214 pushes the permanent magnet block 217 and the cleaning block 216 to slide toward the door 3, the gas in the telescopic tube 214 is slowly discharged from the gas outlet 215. When the telescopic tube 214 is exhausted and reset, the permanent magnet block 217 on the telescopic tube 214 attracts the permanent magnet block 217 on the cleaning block 216, so that the cleaning block 216 returns to its original position.

[0034] The support spring 204 and the return spring 218 are high temperature resistant springs, and the permanent magnet block 217 is a high temperature resistant permanent magnet. The lithium battery explosion-proof test box will detect the battery in an overheated environment. At this time, the lithium battery explosion-proof test box is at a high temperature to prevent the support spring 204 and the return spring 218 from being deformed due to the high temperature, and at the same time, prevent the permanent magnet block 217 from being demagnetized at a high temperature.

[0035] The working principle of the present invention is as follows:

[0036] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 Before the lithium battery explosion-proof test box is inspected, the lithium battery is placed on the buffer plate 203 on the lower side of the box body 2 and the box door 3 is closed. At this time, the box door 3 supports one end of the power rod 213, so that the power rod 213 slides in the buffer plate 203 at the lower end, and the other end of the power rod 213 pushes the blocking block 212 to move, so that the blocking block 212 blocks the through hole of the side wall of the connecting groove 211, so that the gas collecting groove 209, the connecting groove 211 and the telescopic tube 214 are in a disconnected state.

[0037] During the detection operation, when a lithium battery explodes, the lithium battery will quickly generate a large amount of smoke. At this time, since the smoke cannot be immediately discharged through the purification port 201, the air pressure in the box 2 increases. Under the action of the high pressure in the box 2, the smoke in the box 2 pushes the buffer plate 203 to slide into the installation groove 202, so that the buffer plate 203 squeezes the gas in the installation groove 202. In the process of the buffer plate 203 sliding into the installation groove 202, the debris generated by the lithium battery explosion will also rush to the buffer plate 203, and the debris moves with the buffer plate 203. In the process of the buffer plate 203 squeezing the gas in the installation groove 202, the gas buffers the buffer plate 203. At the same time, the buffer plate 203 generates a buffering force on the debris, which reduces the force of the debris hitting the buffer plate 203, thereby reducing the damage to the inner wall of the box 2 by the exploded debris.

[0038] Before the lithium battery explodes, it will quickly generate a large amount of smoke, and the air pressure in the box body 2 will increase. The smoke in the box body 2 will push the buffer plate 203 to slide into the installation groove 202. At this time, the gas in the installation groove 202 is squeezed, and the squeezed gas enters the slide groove 205 through the connecting hole I 207, thereby pushing the support block 206 in the slide groove 205 to slide, so that the support block 206 slides into the closed groove 302, so that the support block 206 is fixed to the edge of the box door 3. When the lithium battery explodes, the impact force generated by the explosion rushes to the box door 3, and the edges of the box door 3 are fixed by the support block 206, thereby preventing the edges of the box door 3 from being lifted up by the impact force generated by the explosion, thereby avoiding the phenomenon of poor sealing effect between the box door 3 and the box body 2.

[0039] When preparing to open the door 3, if the air pressure in the box body 2 is greater than the standard atmospheric pressure, the buffer plate 203 is always in the installation groove 202, and at the same time, the support block 206 is stuck in the closed groove 302, and the door 3 cannot be opened; after the gas in the box body 2 is discharged through the purification port 201, when the air pressure in the box body 2 is less than or equal to the standard atmospheric pressure, under the action of the elastic force of the support spring 204, the buffer plate 203 is reset, and a negative pressure is generated in the installation groove 202 to reset the support block 206, thereby unlocking the door 3 to achieve the unlocking effect, thereby avoiding the phenomenon that the door 3 is opened when the pressure in the box body 2 is high, the high-pressure gas causes the door 3 to pop out, and the door 3 hits the experimenter.

[0040] When a lithium battery explodes, the lithium battery will quickly generate a large amount of smoke, and the impact force generated by the explosion pushes the buffer plate 203 to slide into the mounting groove 202. After the gas in the mounting groove 202 at the lower end of the box body 2 enters the slide groove 205 and the support block 206 enters the closed groove 302, the support block 206 blocks the connecting hole II 208, and the buffer plate 203 at the lower end continues to be pushed. At this time, the gas in the mounting groove 202 passes through the one-way valve 210 and enters the gas collecting groove 209, thereby storing the gas in In the gas collecting groove 209, after the gas inside the box body 2 is discharged and purified through the purification port 201, the pressure inside the box body 2 is reduced, the buffer plate 203 is restored to a certain position, and at the same time, the support block 206 moves down a certain distance. At this time, the support block 206 no longer blocks the connecting hole II 208, and the gas enters the installation groove 202 through the connecting hole II 208. The buffer plate 203 and the support block 206 are restored to their original positions, and the box door 3 can be opened. In the process of opening the box door 3, the blocking block 212 and the power rod 213 are in the reset spring Under the action of the elastic force of the spring 218, the blocking block 212 and the power rod 213 slide in the direction of the box door 3. At this time, the blocking block 212 no longer blocks the through hole, and the gas collecting groove 209, the connecting groove 211 and the telescopic tube 214 are connected. A large amount of high-pressure gas stored in the gas collecting groove 209 quickly enters the telescopic tube 214 through the connecting groove 211, so that the telescopic tube 214 extends. During the extension of the telescopic tube 214, the telescopic tube 214 pushes the cleaning block 216 to slide on the upper end surface of the buffer plate 203, so that the cleaning block 216 The sorting block 216 pushes the debris on the upper end surface of the buffer plate 203 to move toward the box door 3, and the experimenter only needs to sweep the debris into the chip collecting groove 4, which is convenient for the experimenter to clean; when the telescopic tube 214 is extended, the gas in the telescopic tube 214 is slowly discharged through the air outlet 215, and the telescopic tube 214 is retracted. Under the action of the gravitational force of the permanent magnet block 217 on the telescopic tube 214, the permanent magnet block 217 on the telescopic tube 214 attracts the permanent magnet block 217 on the cleaning block 216, thereby driving the cleaning block 216 to return to its original position.

Claims

1. A lithium battery explosion-proof test box, comprising a base (1), a box body (2) and a box door (3), wherein a purification port (201) for exhausting gas is provided on the rear side of the box body (2), characterized in that: The four side walls of the box body (2) are provided with mounting grooves (202), and the mounting grooves (202) are provided with: A buffer plate (203), the buffer plate (203) is slidably sealed and installed in the installation groove (202), and the installation groove (202) is filled with gas; A support spring (204), wherein the support spring (204) is fixedly installed in the installation groove (202), and two ends of the support spring (204) are respectively fixedly connected to the buffer plate (203) and the bottom end of the installation groove (202); A plurality of slide grooves (205) are provided on the side wall of the box body (2) close to the box door (3), a support block (206) is slidably and sealably installed in the slide groove (205), and the bottom end of the slide groove (205) is connected to the bottom end of the installation groove (202) through a connecting hole I (207); A plurality of closed grooves (302) are provided on the side wall of the box door (3) which is close to the box body (2), and the positions of the closed grooves (302) and the sliding grooves (205) correspond one to one.

2. A lithium battery explosion-proof test box according to claim 1, characterized in that: The length of the support block (206) is smaller than the length of the slide groove (205).

3. A lithium battery explosion-proof test box according to claim 1, characterized in that: A limiting block is fixedly installed on one side of the bottom end of the slide groove (205) to prevent the supporting block (206) from blocking the connecting hole I (207).

4. The lithium battery explosion-proof test box according to claim 1, characterized in that: A connecting hole II (208) for connecting the top of the slide groove (205) and the bottom of the mounting groove (202) is provided on the inner wall of the lower end of the box body (2), and the supporting block (206) is located in the slide groove (205) between the connecting hole I (207) and the connecting hole II (208); The bottom end of the rear wall of the box body (2) is provided with: An air collecting groove (209), wherein the air collecting groove (209) is connected to the installation groove (202) via a one-way valve (210); A connecting groove (211), the connecting groove (211) is in close contact with the upper side of the gas collecting groove (209), a blocking block (212) is installed in the connecting groove (211) in a sliding seal, a return spring (218) is provided in the connecting groove (211), and two ends of the return spring (218) are respectively fixedly connected to the blocking block (212) and the inner wall of the connecting groove (211); A telescopic tube (214), the telescopic tube (214) being embedded and installed in the box body (2) close to the upper side of the connecting groove (211), and an air outlet (215) for air outlet is provided at one end of the side wall of the telescopic tube (214); The side wall of the connecting groove (211) where the return spring (218) is installed is provided with two through holes, and the two through holes are respectively connected to the air collecting groove (209) and the telescopic tube (214); A power rod (213) is movably installed in the buffer plate (203), the power rod (213) penetrates the buffer plate (203), one end of the power rod (213) is in close contact with the blocking block (212), and the other end of the power rod (213) is in close contact with the inner wall of the box door (3); a cleaning block (216) which can slide relative to the buffer plate (203) is installed on the upper end surface of the buffer plate (203) at the lower end, and permanent magnet blocks (217) are fixedly installed on the opposite end surfaces of the cleaning block (216) and the telescopic tube (214); A chip collecting groove (4) is fixedly mounted on the side wall of the box body (2), and the chip collecting groove (4) is closely attached to the lower end of the box door (3).

5. A lithium battery explosion-proof test box according to claim 4, characterized in that: The flow direction of the one-way valve (210) is from the installation groove (202) to the gas collecting groove (209).

6. A lithium battery explosion-proof test box according to claim 4, characterized in that: When the box door (3) is not closed, the support spring (204) and the return spring (218) are both in a normal state; when the box door (3) is closed, the return spring (218) is in a compressed state.

7. A lithium battery explosion-proof test box according to claim 4, characterized in that: The permanent magnet block (217) on the end surface of the cleaning block (216) and the permanent magnet block (217) on the end surface of the telescopic tube (214) generate a force of attraction.

8. The lithium battery explosion-proof test box according to claim 4, characterized in that: The support spring (204) and the return spring (218) are high temperature resistant springs, and the permanent magnet block (217) is a high temperature resistant permanent magnet.

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