Safety protection device for assembled battery pack of new energy automobile

Abstract

The invention belongs to the technical field of vehicle safety, and discloses a new energy vehicle assembled battery pack safety protection device which comprises a bottom shell, a top shell and a trigger structure. According to the battery pack cooling device, through the arranged trigger structure, when the temperature in the battery pack rises and exceeds the cooling effect of the liquid cooling plate, the electric control valve located on the lower portion is opened at the moment, the lower pipe pushes the circular plate to move upwards, then the circular plate seals the vent holes, and at the moment, external air cannot enter the battery pack from the vent holes and the vent holes; then, an electric control valve above is controlled to be opened, compressed nitrogen in a compression tank is sprayed out at the moment, air in the battery pack and a battery module connected with a heat conduction block are cooled at the same time, the air in the battery pack is pushed outwards by the compressed nitrogen at the moment, and the air in the battery pack is cooled; the oxygen content in the battery pack is further reduced, so that the battery pack is prevented from spontaneous combustion, and the ignited battery module is extinguished at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle safety, and in particular relates to a safety protection device for a combined battery pack of a new energy vehicle. Background Art

[0002] A new energy vehicle is a vehicle that uses non-traditional fuels or advanced vehicle drive technology. Its main purpose is to use an electric motor instead of a traditional internal combustion engine to drive the vehicle. In order to drive the electric motor, a battery pack is required to store electrical energy in the new energy vehicle. The existing battery pack is composed of an outer shell, a liquid cooling plate, and a battery module. The battery module is cooled by placing the liquid cooling plate under the battery module, and the battery module is fixed to the inside of the battery pack outer shell with bolts and a frame. The various parameters of the battery pack are monitored by using a battery management system.

[0003] The battery pack of existing new energy vehicles uses a thermal management system to monitor the temperature inside the battery pack, and a liquid cooling plate is set at the bottom of the battery module to cool the battery module. At the same time, the heat dissipation holes and ventilation holes of the battery pack are set on the top of the battery pack cover. During the daily driving of the vehicle, the fixing bolts of the battery module will become loose due to the vibration of the vehicle, causing the battery module to jump up and down during the operation of the vehicle and collide with the liquid cooling plate below. When the collision causes the coolant passage inside the liquid cooling plate to deform and become blocked, the cooling efficiency of the liquid cooling plate will be greatly reduced, thereby causing the temperature inside the battery pack to continue to rise. When the battery pack is in a high temperature environment, its service life will be greatly reduced. At the same time, the collision between the battery module and the liquid cooling plate will also cause damage to the battery module casing and the internal battery cells, increasing the risk of short circuit of the battery module. In this case, the battery pack is prone to overheating and spontaneous combustion, leading to the occurrence of safety accidents. Summary of the invention

[0004] The purpose of the present invention is to provide a safety protection device for a new energy vehicle combined battery pack to solve the problems raised in the above background technology.

[0005] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: a safety protection device for a new energy vehicle combined battery pack, comprising a bottom shell and a top shell, the top surface of the top shell is provided with a plurality of air holes, the inner bottom surface of the bottom shell is fixedly connected to a liquid cooling plate, the interior of the bottom shell is fixedly connected to a battery rack, the internal bolts of the battery rack are connected to a plurality of battery modules, and a trigger structure is fixedly arranged on the top of the battery rack; the trigger structure comprises a bottom plate fixedly connected to the top surface of the battery rack and a top plate fixedly connected to the inner bottom surface of the top shell, the top surface of the bottom plate is fixedly connected to a gas spring, and the gas spring The outer side surface of the upper tube is movably sleeved with a return spring, and the center positions of the bottom plate and the top plate are provided with ventilation holes, the bottom surface of the top plate is fixedly connected with an upper tube, the bottom surface of the upper tube is provided with a first sliding groove, the interior of the first sliding groove is slidably connected with a lower tube, the bottom surface of the lower tube is fixedly connected with a push plate, the outer side surfaces of the upper tube and the lower tube are provided with ventilation grooves communicating with their interiors, the top surface of the lower tube is fixedly connected with a plurality of sliding blocks, one end of the sliding blocks is slidably connected to the ventilation groove provided on the outer side surface of the upper tube, the top surface of the lower tube is fixedly connected with a circular plate, and the top surface of the circular plate is provided with a circular ring groove.

[0006] Preferably, a plurality of groups of bases and heat-conducting blocks are fixedly connected to the top surface of the liquid cooling plate, two of the bases form a group and are located between two heat-conducting blocks, the heat-conducting block is located between two battery modules, a plurality of compression tanks are fixedly installed inside the heat-conducting block, two electrically-controlled valves arranged up and down are fixedly connected to the side of the heat-conducting block, the input end of the lower electrically-controlled valve is connected to one of the compression tanks, and the upper electrically-controlled valve is connected to the remaining compression tanks, connecting pipes are fixedly connected to the opposite sides of the two bases, the connecting pipes are communicated with the electrically-controlled valves located below, and the output end of the electrically-controlled valves located above is fixedly connected to an upward pipe, a telescopic rod is fixedly connected to the top surface of the base, the telescopic end of the telescopic rod passes through the battery rack and the bottom plate and is fixedly connected to the bottom surface of the push plate.

[0007] Preferably, the top surface of the push plate is fixedly connected with a lower gasket, the lower gasket is fixedly sleeved on the outer side surface of the lower tube, the inner top surface of the first slide groove is fixedly connected with an upper gasket, and one side of the top shell is fixedly connected with a constant pressure valve.

[0008] Preferably, the inner diameter of the upper tube is the same as the diameter of the vent hole, and the interior of the upper tube is communicated with the vent hole, the circular plate is slidably connected to the interior of the upper tube, and after the lower tube moves upward along the first slide groove until the stroke ends, the circular plate closes the top end of the upper tube so that the upper tube is no longer communicated with the vent hole.

[0009] Preferably, the two electrically controlled valves are connected to a battery management system, and after the compression tank connected to the lower electrically controlled valve is emptied, the upper electrically controlled valve opens.

[0010] Preferably, the vent hole is in communication with the air-permeable hole, the elastic force provided by the return spring prevents the gas spring from being completely retracted to the retracted telescopic end, and the bottom surface of the bottom plate abuts against the top surface of the battery module.

[0011] The beneficial effects of the present invention are as follows:

[0012] 1. In the present invention, by setting a trigger structure, during the daily driving of the vehicle, when the bolts between the battery module and the battery rack become loose, the elastic force provided by the gas spring and the return spring counteracts the inertia of the battery module moving upward, preventing the battery module from colliding with the liquid cooling plate below, causing the liquid cooling plate to fail to work normally. At the same time, when the temperature inside the battery pack rises and exceeds the cooling effect of the liquid cooling plate, the electric control valve located below opens, causing the lower tube to push the circular plate upward, thereby causing the circular plate to close the vent hole. At this time, the outer The air from the outside cannot enter the battery pack through the air vents and the vents, preventing oxygen from continuing to enter the battery pack and increasing the risk of spontaneous combustion. The electronic control valve above is then controlled to open, and the compressed nitrogen in the compression tank is ejected. At the same time, the air in the battery pack and the battery module connected to the heat conductive block are cooled, further preventing the battery pack from spontaneous combustion. At this time, due to the increase in air pressure in the battery pack, the constant pressure valve is opened, and the air in the battery pack is pushed outward by the compressed nitrogen, further reducing the oxygen content in the battery pack, preventing the battery pack from spontaneous combustion while extinguishing the battery module that has already caught fire.

[0013] 2. The present invention provides ventilation grooves, so that in daily use, air can freely pass through the ventilation grooves and ventilation holes to remove the heat in the battery pack. When the telescopic end of the lower telescopic rod extends upward and drives the lower tube to move upward, it also guides the slider, so that the lower tube connected to the slider will not shift during the upward movement, thereby preventing the circular plate from shifting due to the shift of the lower tube and failing to seal the top of the upper tube, so that external oxygen can still enter the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0015] Figure 2 It is a schematic diagram of the internal structure of the present invention;

[0016] Figure 3 It is a schematic cross-sectional view of the internal structure of the present invention;

[0017] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle;

[0018] Figure 5 It is a schematic diagram of the structure of the trigger structure of the present invention;

[0019] Figure 6 It is a cross-sectional view of the trigger structure of the present invention;

[0020] Figure 7 For the present invention Figure 6 Enlarged view of point B in the middle;

[0021] Figure 8 It is a partial cross-sectional view of the heat conductive block of the present invention.

[0022] In the figure: 1. bottom shell; 2. top shell; 21. air vent; 22. constant pressure valve; 3. liquid cooling plate; 4. battery rack; 41. battery module; 5. trigger structure; 51. bottom plate; 52. top plate; 53. gas spring; 54. return spring; 55. air vent; 56. upper tube; 57. first slide groove; 58. lower tube; 59. push plate; 510. air vent; 511. slider; 512. round plate; 513. annular groove; 514. base; 515. heat transfer block; 516. electric control valve; 517. compression tank; 518. connecting pipe; 519. telescopic rod; 520. lower gasket; 521. upper gasket. DETAILED DESCRIPTION

[0023] 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.

[0024] like Figures 1 to 8As shown, an embodiment of the present invention provides a safety protection device for a combined battery pack of a new energy vehicle, comprising a bottom shell 1 and a top shell 2, wherein a plurality of vent holes 21 are provided on the top surface of the top shell 2, a liquid cooling plate 3 is fixedly connected to the inner bottom surface of the bottom shell 1, a battery rack 4 is fixedly connected to the inside of the bottom shell 1, a plurality of battery modules 41 are connected to the internal bolts of the battery rack 4, and a trigger structure 5 is fixedly arranged on the top of the battery rack 4; the trigger structure 5 comprises a bottom plate 51 fixedly connected to the top surface of the battery rack 4 and a top plate 52 fixedly connected to the inner bottom surface of the top shell 2, a gas spring 53 is fixedly connected to the top surface of the bottom plate 51, a return spring 54 is movably sleeved on the outer side surface of the gas spring 53, and a bottom plate 52 is fixedly connected to the top surface of the battery rack 4 and a top plate 52 is fixedly connected to the inner bottom surface of the top shell 2, a gas spring 53 is fixedly connected to the top surface of the bottom plate 51, a return spring 54 is movably sleeved on the outer side surface of the gas spring 53, and a trigger structure 5 is fixedly arranged on the top of the battery rack 4. A vent hole 55 is provided at the center position of the plate 51 and the top plate 52, an upper tube 56 is fixedly connected to the bottom surface of the top plate 52, a first slide groove 57 is provided on the bottom surface of the upper tube 56, a lower tube 58 is slidably connected inside the first slide groove 57, a push plate 59 is fixedly connected to the bottom surface of the lower tube 58, an air-permeable groove 510 communicating with the interior is provided on the outer side surfaces of the upper tube 56 and the lower tube 58, a plurality of sliders 511 are fixedly connected to the top surface of the lower tube 58, one end of the slider 511 is slidably connected to the air-permeable groove 510 provided on the outer side surface of the upper tube 56, a circular plate 512 is fixedly connected to the top surface of the lower tube 58, and an annular groove 513 is provided on the top surface of the circular plate 512.

[0025] In the present invention, by setting the trigger structure 5, during the daily driving of the vehicle, when the bolts between the battery module 41 and the battery rack 4 become loose, the elastic force provided by the gas spring 53 and the return spring 54 counteracts the inertia of the battery module 41 moving upward, preventing the battery module 41 from colliding with the liquid cooling plate 3 below, causing the liquid cooling plate 3 to fail to work normally. At the same time, when the temperature in the battery pack rises and exceeds the cooling effect of the liquid cooling plate 3, the electric control valve 516 located below opens, so that the lower tube 58 pushes the circular plate 512 to move upward, thereby causing the circular plate 512 to close the vent 55. At this time, outside air cannot enter the battery pack through the air vent 21 and the air vent 55, preventing oxygen from continuing to enter the battery pack and increasing the risk of spontaneous combustion. The upper electric control valve 516 is then controlled to open, and the compressed nitrogen in the compression tank 517 is ejected. At the same time, the air in the battery pack and the battery module 41 connected to the heat conductive block 515 are cooled, further preventing the battery pack from spontaneous combustion. At this time, due to the increase in air pressure in the battery pack, the constant pressure valve 22 is opened, and the air in the battery pack is pushed outward by the compressed nitrogen, further reducing the oxygen content in the battery pack, thereby preventing the battery pack from spontaneous combustion and extinguishing the battery module 41 that has caught fire.

[0026] By setting up the ventilation groove 510 in the present invention, in daily use, air can freely pass through the ventilation groove 510 and the ventilation hole 21 to remove the heat in the battery pack. When the telescopic end of the telescopic rod 519 below extends upward and drives the lower tube 58 to move upward, it also guides the slider 511, so that the lower tube 58 connected to the slider 511 will not shift during the upward movement, thereby preventing the circular plate 512 from shifting due to the shift of the lower tube 58 and failing to seal the top of the upper tube 56, so that external oxygen can still enter the battery pack.

[0027] like Figure 3 and Figure 4 As shown, the top surface of the liquid cooling plate 3 is fixedly connected with multiple groups of bases 514 and heat-conducting blocks 515, two bases 514 form a group and are located between the two heat-conducting blocks 515, the heat-conducting blocks 515 are located between the two battery modules 41, and multiple compression tanks 517 are fixedly installed inside the heat-conducting blocks 515. The sides of the heat-conducting blocks 515 are fixedly connected with two electric-controlled valves 516 arranged up and down, the input end of the lower electric-controlled valve 516 is connected to a compression tank 517, and the upper electric-controlled valve 516 is connected to the remaining compression tanks 517. The opposite sides of the two bases 514 are fixedly connected with connecting pipes 518, the connecting pipes 518 are communicated with the electric-controlled valves 516 located below, and the output end of the electric-controlled valve 516 located above is fixedly connected with an upward pipeline, and the top surface of the base 514 is fixedly connected with a telescopic rod 519, and the telescopic end of the telescopic rod 519 passes through the battery rack 4 and the bottom plate 51 and is fixedly connected to the bottom surface of the push plate 59.

[0028] The electric control valve 516 opens when the power is off to prevent the battery management system of the battery pack from failing to work properly. The heat conductive block 515 located between the two battery modules 41 not only prevents the battery module 41 from moving left and right, causing the two battery modules 41 to collide, resulting in the battery module 41 shell being broken and short-circuited, but also when the compressed gas in the compression tank 517 is ejected, the compressed nitrogen reduces the temperature of the tank body, and the battery modules 41 on both sides are cooled by the heat conductive effect of the heat conductive block 515 to prevent the battery pack from overheating and self-ignition. At the same time, when the battery pack self-ignites, as the compressed nitrogen is ejected, the gas in the battery pack is replaced by the compressed nitrogen. When the compressed nitrogen is ejected, its temperature will be lower than the ambient temperature according to the adiabatic expansion phenomenon, so that the overall temperature in the battery pack is reduced. At the same time, the nitrogen will not react with the battery unit and the electrolyte, and has a flame retardant and fire extinguishing effect, thereby extinguishing the flame of the battery module 41 and improving the safety of the battery pack during use.

[0029] like Figures 5 to 7As shown, the top surface of the push plate 59 is fixedly connected with a lower gasket 520, and the lower gasket 520 is fixedly sleeved on the outer side surface of the lower tube 58, the inner top surface of the first slide groove 57 is fixedly connected with an upper gasket 521, and one side of the top shell 2 is fixedly connected with a constant pressure valve 22, the inner diameter of the upper tube 56 is the same as the diameter of the vent hole 55, and the interior of the upper tube 56 is connected to the vent hole 55, the circular plate 512 is slidably connected to the interior of the upper tube 56, and the lower tube 58 moves upward along the first slide groove 57 until the stroke ends, and the circular plate 512 closes the top end of the upper tube 56, so that the upper tube 56 is no longer connected to the vent hole 55.

[0030] The lower gasket 520 and the upper gasket 521 are both made of high-temperature resistant elastic materials. When the circular plate 512 is pushed upward by the lower tube 58 to the end of the stroke of the first slide groove 57, that is, after the circular plate 512 moves up to the highest point, the top surface of the circular plate 512 located in the first slide groove 57 contacts the bottom surface of the upper gasket 521. At this time, the circular plate 512 closes the upper end of the upper tube 56. At this time, the upper tube 56 and the vent 55 are no longer connected. At this time, the inside and outside of the battery pack are isolated, preventing outside air from entering the battery pack from the vent 21, resulting in the spontaneous combustion of the overheated battery module 41 due to the oxygen contained in the air.

[0031] Among them, the two electric control valves 516 are connected to the battery management system. After the compression tank 517 connected to the electric control valve 516 located at the bottom is emptied, the electric control valve 516 located at the top is opened.

[0032] The battery pack monitors its various data through the battery management system equipped. When the battery module 41 in the battery pack overheats or catches fire, the electric control valve 516 located at the bottom is first opened to allow the compressed gas in the compression tank 517 connected thereto to be ejected, driving the telescopic rod 519 to extend, thereby causing the lower tube 58 to push the circular plate 512 upward to isolate the battery pack from the outside world. Subsequently, the electric control valve 516 at the top is activated to allow the compressed nitrogen in the compression tank 517 connected thereto to be ejected. On the one hand, the compressed nitrogen will reduce the tank body temperature of the compression tank 517 when ejected, and the adjacent battery module 41 will be cooled by the heat conduction of the heat conductive block 515. At the same time, the ejected compressed nitrogen will increase the air pressure in the battery pack. At this time, the constant pressure valve 22 is opened, and the pressure provided by the compressed nitrogen causes the air in the battery pack to leave the constant pressure valve 22, thereby reducing the oxygen content in the battery pack. When the battery module 41 spontaneously ignites, it loses oxygen and extinguishes, thereby improving the safety of the battery pack.

[0033] The vent hole 55 is connected to the vent hole 21 , and the elastic force provided by the return spring 54 prevents the gas spring 53 from being completely retracted to the retracted telescopic end, and the bottom surface of the bottom plate 51 abuts against the top surface of the battery module 41 .

[0034] When the bolts between the battery module 41 and the battery rack 4 become loose, causing the battery module 41 to move up and down during driving, the thrust provided by the gas spring 53 and the return spring 54 will counteract the inertia of the battery module 41 moving upward, making it impossible for the battery module 41 to move up and down, thereby preventing the battery module 41 from causing damage to the liquid cooling plate 3 and its own casing when moving up and down, causing a short circuit in the battery module 41, and thus causing a fire.

[0035] Working principle:

[0036] When using the battery pack safety protection device of the present invention, first fix the base 514 and the heat conductive block 515 on the top surface of the liquid cooling plate 3, then install the battery module 41 inside the battery rack 4, then fix the bottom plate 51 on the top surface of the battery rack 4, then fix the push plate 59 on the top of the telescopic end of the telescopic rod 519, then fix the gas spring 53 on the top surface of the bottom plate 51, and sleeve the return spring 54 on the gas spring 53, then install the lower tube 58, the circular plate 512 and the upper tube 56, finally connect the top plate 52 with the top end of the gas spring 53 and the top end of the upper tube 56, then fix the top shell 2 on the bottom shell 1, and fix the top plate 52 with the top shell 2 so that the vent hole 55 is connected with the vent hole 21, and complete the installation of the battery pack safety protection device.

[0037] When the vehicle is driving and charging, when the temperature of the battery module 41 is higher than the safe temperature preset by the battery management system, the battery management system cuts off the circuit of the electric control valve 516 located below, causing it to be powered off and open. At this time, the telescopic end of the telescopic rod 519 extends, thereby pushing the push plate 59 to move upward, driving the lower tube 58 and the circular plate 512 to move upward. As the telescopic rod 519 is fully extended, the circular plate 512 closes the top of the upper tube 56. At this time, the inside of the battery pack is isolated from the outside, and the outside air cannot enter the battery pack. When the telescopic rod 519 is fully extended After that, the electric control valve 516 located at the top opens, so that the compressed nitrogen in the compression tank 517 connected thereto is ejected. When the compressed nitrogen is ejected, the tank body temperature of the compression tank 517 drops, and the adjacent battery module 41 is cooled by the heat conduction effect of the heat conductive block 515. At the same time, after the compressed nitrogen is ejected, the temperature inside the battery pack will drop, thereby cooling the battery pack. At the same time, after the compressed nitrogen is ejected, the air pressure in the battery pack rises. At this time, the constant pressure valve 22 opens, and the internal air leaves the battery pack under the push of the compressed nitrogen to reduce the oxygen concentration in the battery pack.

[0038] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A safety protection device for a new energy vehicle combined battery pack, comprising a bottom shell (1) and a top shell (2), Features: The top surface of the top shell (2) is provided with a plurality of vent holes (21); the inner bottom surface of the bottom shell (1) is fixedly connected to a liquid cooling plate (3); the interior of the bottom shell (1) is fixedly connected to a battery rack (4); the interior of the battery rack (4) is bolted with a plurality of battery modules (41); and a trigger structure (5) is fixedly provided on the top of the battery rack (4); The trigger structure (5) comprises a bottom plate (51) fixedly connected to the top surface of the battery rack (4) and a top plate (52) fixedly connected to the inner bottom surface of the top shell (2); the top surface of the bottom plate (51) is fixedly connected to a gas spring (53); the outer side surface of the gas spring (53) is movably sleeved with a return spring (54); the center positions of the bottom plate (51) and the top plate (52) are both provided with vent holes (55); the bottom surface of the top plate (52) is fixedly connected to an upper tube (56); the bottom surface of the upper tube (56) is provided with a first slide groove (57); the first slide groove (57) ) is slidably connected to the interior of the lower tube (58), a push plate (59) is fixedly connected to the bottom surface of the lower tube (58), the outer side surfaces of the upper tube (56) and the lower tube (58) are both provided with air-permeable grooves (510) communicating with the interior thereof, a plurality of sliders (511) are fixedly connected to the top surface of the lower tube (58), one end of each slider (511) is slidably connected to the air-permeable grooves (510) provided on the outer side surface of the upper tube (56), a circular plate (512) is fixedly connected to the top surface of the lower tube (58), and a circular groove (513) is provided on the top surface of the circular plate (512).

2. A safety protection device for a new energy vehicle combined battery pack according to claim 1, Features: The top surface of the liquid cooling plate (3) is fixedly connected to a plurality of groups of bases (514) and heat conducting blocks (515), two of the bases (514) form a group and are located between two heat conducting blocks (515), the heat conducting blocks (515) are located between two battery modules (41), a plurality of compression tanks (517) are fixedly installed inside the heat conducting blocks (515), and two electric control valves (516) arranged up and down are fixedly connected to the side of the heat conducting blocks (515), the input end of the lower electric control valve (516) is connected to one of the compression tanks (517), and the upper electric control valve (516) is connected to the input end of the compression tank (517). The electric control valve (516) is connected to the remaining compression tanks (517); a connecting pipe (518) is fixedly connected to the opposite sides of the two bases (514); the connecting pipe (518) is communicated with the electric control valve (516) located below; the output end of the electric control valve (516) located above is fixedly connected to an upward pipeline; a telescopic rod (519) is fixedly connected to the top surface of the base (514); the telescopic end of the telescopic rod (519) passes through the battery rack (4) and the bottom plate (51) and is fixedly connected to the bottom surface of the push plate (59).

3. A safety protection device for a new energy vehicle combined battery pack according to claim 2, Features: The top surface of the push plate (59) is fixedly connected to a lower gasket (520), and the lower gasket (520) is fixedly sleeved on the outer side surface of the lower tube (58). The inner top surface of the first slide groove (57) is fixedly connected to an upper gasket (521), and one side of the top shell (2) is fixedly connected to a constant pressure valve (22).

4. A safety protection device for a new energy vehicle combined battery pack according to claim 3, Features: The inner diameter of the upper tube (56) is the same as the diameter of the vent hole (55), and the interior of the upper tube (56) is communicated with the vent hole (55). The circular plate (512) is slidably connected to the interior of the upper tube (56). After the lower tube (58) moves upward along the first slide groove (57) until the stroke ends, the circular plate (512) closes the top end of the upper tube (56), so that the upper tube (56) is no longer communicated with the vent hole (55).

5. A safety protection device for a new energy vehicle combined battery pack according to claim 4, Features: The two electric control valves (516) are connected to a battery management system. After the compression tank (517) connected to the lower electric control valve (516) is emptied, the upper electric control valve (516) is opened.

6. A safety protection device for a new energy vehicle combined battery pack according to claim 5, Features: The vent hole (55) is in communication with the air hole (21), and the elastic force provided by the return spring (54) prevents the gas spring (53) from being completely retracted to the retracted telescopic end, and the bottom surface of the bottom plate (51) abuts against the top surface of the battery module (41).

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