Valve for battery pack and battery pack

Abstract

The invention relates to the technical field of vehicles, in particular to a valve for a battery pack, which is provided with a valve body support, a valve rod, a valve rod, a valve rod, a valve rod, a valve rod, a valve rod and a valve rod, and is characterized in that the valve body support is provided with a first opening at one end and a second opening at the other end; the breathable film covers the first opening; the piston covers the second opening and comprises a hole, and the hole is closed by an openable sealing part. The invention also discloses a battery pack using the valve. By using the valve, the internal pressure and the external pressure of the battery pack can be balanced, water and dust can be effectively prevented, and the internal pressure of the battery pack can be more effectively controlled when the internal pressure of the battery pack is rapidly increased.

Description

Technical Field

[0001] The present invention generally relates to the technical field of vehicles, and more particularly, to a valve for a battery pack of a vehicle and a battery pack using the valve. Background Art

[0002] Generally, a valve is used to close a container for pressure exchange with the outside world to achieve a desired pressure balance. In practical applications, the valve structures of valves are diverse and have rich application scenarios. In the field of vehicles, electric vehicles have developed rapidly due to their advantages in reducing fuel consumption and exhaust emissions. Electric vehicles include, but are not limited to, hybrid vehicles, plug-in hybrid vehicles, and pure electric vehicles, etc. In a typical electric vehicle, a battery pack is usually included, and the application of a valve with a pressure balancing function on the battery pack is also relatively common. With the increase in the cruising range of pure electric vehicles, ternary batteries are used in battery pack designs, and the airtightness of the battery becomes more important for the normal operation of electric vehicles. Good airtightness can effectively prevent water, water vapor, or dust from entering the battery pack and affecting the internal environment of the battery pack, but at the same time, it is also necessary to meet the requirements of balancing the internal and external air pressures of the battery pack and quickly exhausting air when necessary.

[0003] The inventors of the present application have realized that based on the requirements for the airtightness and pressure balance of the battery pack, there is a need for further optimization in the valve structure for the battery pack to solve one or more problems existing in the prior art. Summary of the Invention

[0004] Aiming at the problems existing in the related art, the purpose of the present invention is to provide a valve for a battery pack and a battery pack.

[0005] According to the present invention, there is provided a valve for a battery pack, the valve having:

[0006] A valve body bracket having a first opening at one end and a second opening at the other end;

[0007] A breathable membrane covering the first opening;

[0008] A piston covering the second opening, the piston including a hole, and the hole is closed by an openable sealing portion.

[0009] According to an embodiment of the present invention, the sealing portion is at least one of a sealing core, a valve flap, and a notch.

[0010] According to an embodiment of the present invention, the sealing core is biased towards a first direction by a first elastic member to close the hole.

[0011] According to an embodiment of the present invention, the piston is biased towards a second direction by a second elastic member to cover the second opening.

[0012] According to an embodiment of the present invention, the valve body bracket further includes a base, a second opening is provided on the base, and the base supports a first elastic member.

[0013] According to an embodiment of the present invention, the bottom of the piston has a supporting portion, and the first elastic member is supported through the supporting portion.

[0014] According to an embodiment of the present invention, the valve body bracket has a guide groove, and the sealing core is biased by the first elastic member to partially pass through the hole and enter the guide groove.

[0015] According to an embodiment of the present invention, under a first pressure difference, the sealing core moves in a second direction to open the hole so that the gas in the external environment flows into the interior of the housing of the battery pack.

[0016] According to an embodiment of the present invention, under a first pressure difference, the incision deforms to open the hole so that the gas in the external environment flows into the interior of the housing of the battery pack.

[0017] According to an embodiment of the present invention, under a first pressure difference, the valve flap pivots around the flap shaft to open the hole.

[0018] According to an embodiment of the present invention, under a second pressure difference, the piston moves in a first direction to open the first opening so that the gas in the housing of the battery pack flows out.

[0019] According to an embodiment of the present invention, the sealing core is a sealing plate covering the hole to close the hole.

[0020] According to an embodiment of the present invention, the sealing core has a core body and a flange extending circumferentially outward from the core body, and the flange abuts against the hole under the biasing of the first elastic member to seal the hole.

[0021] According to an embodiment of the present invention, the sealing core has a first spike extending toward the breathable membrane, and a first gap is provided between the first spike and the breathable membrane.

[0022] According to an embodiment of the present invention, the valve further has a valve cover, and the valve cover has a connecting portion connected to the housing of the battery pack;

[0023] The valve cover is engaged at the upper end of the valve body bracket and covers the breathable membrane with a second gap;

[0024] The valve cover has a second spike extending toward the breathable membrane, and the length of the second spike is less than the second gap.

[0025] According to an embodiment of the present invention, the valve cover has at least one valve cover window provided on the side wall, and when the valve cover is engaged at the upper end of the valve body bracket, the valve cover window is located above the breathable membrane in the longitudinal direction.

[0026] According to one embodiment of the present invention, the base is detachably engaged with or integrally formed with the main body of the valve body bracket.

[0027] According to the present invention, there is also provided a method for controlling the pressure of a battery pack, comprising:

[0028] providing at least one gas exchange chamber having a first passage and a second passage, the first passage and the second passage being in communication with the external environment and the interior of the housing of the battery pack respectively;

[0029] The gas exchange chamber is configured to:

[0030] close the first passage and the second passage when there is no pressure difference;

[0031] open the first passage to allow the gas in the external environment to flow into the interior of the housing of the battery pack when there is a first pressure difference; and

[0032] open the second passage to allow the gas in the interior of the housing of the battery pack to flow out to the external environment when there is a second pressure difference.

[0033] According to one embodiment of the present invention, it further comprises:

[0034] providing a breathable membrane between the gas exchange chamber and the external environment to prevent moisture from entering the gas exchange chamber; and

[0035] rupturing the breathable membrane to increase the gas passage amount of the second passage when the second pressure difference is greater than a threshold value.

[0036] According to another aspect of the present invention, there is provided a battery pack having a valve mounted on the housing of the battery pack, the valve having:

[0037] a valve body bracket having a first opening at one end and a second opening at the other end;

[0038] a breathable membrane covering the first opening;

[0039] a piston covering the second opening, the piston including a hole closed by an openable sealing portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] To better understand the present invention, reference may be made to the embodiments shown in the following drawings. The components in the drawings are not necessarily drawn to scale, and related elements may be omitted, or in some cases the scale may be enlarged to emphasize and clearly show the novel features described herein. Additionally, as known in the art, the system components may be arranged differently. Further, in the drawings, the same reference numerals represent corresponding parts throughout several views.

[0041] Figure 1An electrified vehicle with a battery pack to which the present application can be applied is shown;

[0042] Figures 2A - 2B The front view and top view of a valve that can be used in a vehicle battery pack in an embodiment of the present invention are shown;

[0043] Figure 3 An internal structure embodiment diagram of a valve that can be used in a vehicle battery pack in an embodiment of the present invention is shown;

[0044] Figures 3A - 3C The Figure 3 schematic diagram of the gas flow direction of the valve in different working states in the embodiment of is shown;

[0045] Figures 4A - 4B The exploded structural schematic diagram of a valve that can be used in a vehicle battery pack in an embodiment of the present invention is shown;

[0046] Figure 5 The schematic diagram of the valve body bracket of the valve in an embodiment of the present invention is shown;

[0047] Figure 6A The schematic diagram of the cooperation between the piston and the base in an embodiment of the present invention is shown;

[0048] Figure 6B The schematic diagram of the cooperation between the compression core of the piston and the base in an embodiment of the present invention is shown; and the cross-section of the flexible element taken along the Figure 2B X-X line of Figure 1 the schematic flow path of the gas inflow in one embodiment;

[0049] Figures 7A - 7B The structural schematic diagram of the piston body of the piston in an embodiment of the present invention is shown;

[0050] Figure 8 The structural schematic diagram of the cooperation between the base and the bracket cap in an embodiment of the present invention is shown;

[0051] Figures 9A - 9C The Figure 2B cross-sections of the valve in different working states taken along the X-X line of Detailed Description of the Embodiment

[0052] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. For the reference numerals in the drawings, the same or similar reference numerals are used to indicate the same or similar components. In the following description, a number of operating parameters and components are described in a number of embodiments. These specific parameters and components are included herein only as examples and are not meant to be limiting.

[0053] Embodiments of the present disclosure are described below. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms. The accompanying drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show details of particular components. Accordingly, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching one skilled in the art to use the present application in various ways. As will be understood by those of ordinary skill in the art, the various features shown and described with reference to any one of the accompanying drawings may be combined with features shown in one or more other drawings to produce embodiments that are not explicitly shown or described. Combinations of the shown features provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desirable for certain specific applications or implementations.

[0054] In this application, relational terms such as first and second, etc. are used solely to distinguish one entity or action from another entity or action, and do not necessarily require or imply any actual such relationship or order between such entities or actions. The term "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a series of elements does not include only those elements, but may also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprising" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0055] As used herein, the term "and / or" when used to list two or more items means that any one of the listed items can be taken by itself, or any combination of two or more of the listed items can be taken.

[0056] One or more embodiments of the present application will be described below in conjunction with the accompanying drawings. Flowcharts are used to illustrate examples of processes executed by a system. It can be understood that the execution of the flowchart does not need to be in sequence, one or more steps can be omitted, one or more execution steps can be added, and the steps can be in sequence or reverse order, and even in some embodiments, one or more steps can be executed simultaneously.

[0057] As mentioned in the background art, valves can be used to block the pressure exchange between a container and the outside world to achieve a desired pressure balance. With the rapid development of electric vehicles due to their advantages in reducing fuel consumption and exhaust emissions, the application of valves on battery packs is very common, so as to achieve the effects of waterproof and dustproof sealing of the battery pack and gas exchange under different pressures to balance the air pressure inside and outside the battery pack.

[0058] There are currently various designs of valves for battery packs, and the inventors of the present application believe that there is room for further improvement in valves, especially valves for battery packs. In one or more embodiments, the inventors of the present application have proposed a valve that has one or more advantages among structural robustness, connection convenience, and test convenience. In one or more embodiments, the present application also provides a battery pack that can maintain pressure balance under normal pressure conditions and effectively prevent moisture and the like from entering the interior of the battery pack when using the valve designed as above, and can open an air circulation channel to balance the pressure between the interior and the external environment of the battery pack when there is a pressure difference between the interior and the external environment of the battery pack. In addition, it can effectively reduce the pressure inside the battery pack under thermal shock changes where heat is generated rapidly. In an example of the present invention, when the pressure difference between the external environment and the interior of the battery pack is 3 - 4 Kpa, the air flow rate provided by the valve towards the air circulation channel inside the battery pack is not less than 25 ml / min. When the pressure difference between the interior of the battery pack and the external environment is 1 - 1.8 Kpa, the air flow rate provided by the valve towards the air circulation channel to the external environment is not less than 1 L / min. And when the pressure difference between the interior and the external environment of the battery pack is 8 - 12 Kpa, the air flow rate provided by the valve towards the air circulation channel to the external environment is not less than approximately 1000 L / min.

[0059] Reference Figure 1 , which shows an example of an electrified vehicle 12 with a battery pack to which the present application can be applied. Although shown as a hybrid electric vehicle (HEV), it should be understood that the battery pack of the present application can be used in other types of deep - hybrid plug - in electric vehicles (PHEV), battery electric vehicles (BEV), full - hybrid electric vehicles (FHEV), etc.

[0060] In one embodiment, the powertrain 10 is a power - distributing powertrain. It includes a first drive system and a second drive system. The first drive system includes a combination of an engine 14 and a generator 18 (i.e., the first motor). The second drive system includes at least a motor 22 (i.e., the second motor), a generator 18, and a battery assembly. In this example, the second drive system is considered the electric drive system of the powertrain 10. The first drive system and the second drive system generate torque to drive one or more sets of vehicle drive wheels 28 of the electrified vehicle 12. Although in this illustrative embodiment, the figure shows a power - splitting configuration, the present application extends to any hybrid electric vehicle including full - hybrid, parallel - hybrid, series - hybrid, mild - hybrid, and micro - hybrid. The engine 14 and the generator 18 can be connected through a power transmission unit 30. In addition to planetary gear sets, other types of power transmission units can also be used to connect the engine 14 to the generator 18. In a non - limiting example, the planetary gear set includes a ring gear 32, a sun gear 34, and a carrier assembly 36.

[0061] The generator 18 can be driven by the engine 14 through the power transmission unit 30 to convert kinetic energy into electrical energy. The generator 18 can alternatively be used as a motor to convert electrical energy into kinetic energy, thereby outputting torque to the shaft 38 connected to the power transmission unit 30. Since the generator 18 is operably connected to the engine 14, the speed of the engine 14 can be controlled by the generator 18.

[0062] The ring gear 32 of the power transmission unit 30 can be connected to the shaft 40, and the shaft 40 is connected to the vehicle drive wheels 28 through the second power transmission unit 44. The second power transmission unit 44 can include a gear set having a plurality of gears 46. Other power transmission units may also be suitable. The gears 46 transmit torque from the engine 14 to the differential 48 to ultimately provide traction to the vehicle drive wheels 28. The differential 48 can include a plurality of gears that enable torque to be transmitted to the vehicle drive wheels 28. In one embodiment, the second power transmission unit 44 is mechanically coupled to the axle 50 through the differential 48 to distribute torque to the vehicle drive wheels 28.

[0063] The battery assembly 24 is an example type of an electrified vehicle battery assembly. The battery assembly 24 can provide electrical power for the drive motor, and in regenerative braking, the motor 22 and the generator 18 can output electrical power to the battery assembly 24 for storage. The battery assembly 24 can include a high-voltage battery pack, which can include a plurality of battery arrays. In the following embodiments, a battery pack that can be incorporated into the above example electrified vehicle is provided.

[0064] As Figures 2A - 2B shown are a front view and a top view of the valve 100 in one or more embodiments of the present application. As shown, the valve 100 has a valve cover 140, the valve cover 140 has a main body portion and a lower end edge 141 that protrudes from the main body portion and extends circumferentially. The lower end portion of the valve cover 140 also has a threaded portion 1411. In an embodiment of the present invention, through the threaded portion 1411, the valve cover 140 can be connected to the housing of the battery pack, thereby completing the connection between the valve 100 and the battery pack. It can be understood that other connection methods, such as welding, connection by fasteners, adhesive bonding, etc., can also be used for the connection between the valve 100 and the battery pack housing. The structure of the valve 100 will be further described with reference to additional drawings.

[0065] As Figure 3Shown is a schematic diagram of the internal structure of a pressure relief valve 100 for a battery pack in an embodiment of the present application, including a valve body bracket 101. The valve body bracket 101 has a first opening covered by a breathable membrane 170, and the first opening communicates with the external environment. The valve body bracket 101 also has a second opening 102. In this embodiment, the number of the second openings 102 is two. However, those skilled in the art can understand that the number of the second openings 102 can be set according to the ventilation volume requirement and the structural strength requirement of the valve body bracket 101. In Figure 3 the shown embodiment, the second opening 102 is covered by a piston 103. The piston is supported on the valve body bracket 101 by a second elastic member 107 so that it is biased to cover and seal the second opening 102. The upper end of the piston 103 has a hole 105, and the hole 105 is closed by a sealing portion. In Figure 3 it, the sealing portion is separated from the hole 105 to clearly show the hole 105. In Figure 3 the shown embodiment, the sealing portion is embodied as a sealing core 104, and the sealing core 104 is biased by a first elastic member 106 to close the hole 105. It can be understood that in other embodiments of the present invention, the sealing portion can close the hole 105 in the form of a valve flap or a notch. For example, the valve flap pivots around a shaft to close or open the hole 105, and a spring is arranged on the shaft to bias the valve flap against the hole 105. In another embodiment, the sealing portion can be formed without using an elastic member to bias the hole 105. For example, a notch is arranged on the upper surface of the piston 103 formed by a deformable material, and the shape of the notch can be set according to the required pressure threshold, and can be set to various shapes such as a straight shape, a cross shape, a semicircular shape, etc. The notch closes the hole 105 in the normal state, and when receiving a pressure greater than the threshold, the hole 105 is opened through the deformation of the notch material. In addition, in Figure 3 the shown embodiment, the first elastic member 106 is supported on the supporting portion of the bottom wall of the bracket where the second opening 102 of the valve body bracket 101 is located. In the embodiment of the present invention, the supporting portion is integrally formed with the valve body bracket 101 or fixed to the valve body bracket 101 by means of mechanical connection, adhesive bonding, etc.

[0066] Continuing as Figure 3 shown, a gas exchange chamber C formed by the valve body bracket 101, the breathable membrane 170, the piston 103, and the sealing core 104 is shown in dashed lines in the internal structure of the valve 100 1 , and this gas exchange chamber C 1 serves as a gas buffer area between the external environment and the inside of the battery pack. It has a first channel and a second channel for gas exchange, and is used for gas exchange under different external environmental air pressures and battery pack internal air pressure states.

[0067] Specifically, as Figures 3A - 3C shown in Figure 3 the schematic diagram of the gas flow direction of the valve 100 in the embodiment of Figure 3A under different working states. First, as

[0068] shown in Figure 3B when the pressure difference between the external environment and the internal pressure of the battery pack is within the threshold range, the hole 105 and the second opening 102 are respectively closed by the sealing core 104 and the piston 103, so that the first channel and the second channel are closed, resulting in the inability to exchange gas between the external environment and the inside of the battery pack.

[0069] Then in Figure 3C the working state shown in, it is marked by the dotted arrow that when the pressure difference between the gas pressure of the external environment and the gas pressure inside the battery pack exceeds the threshold, the sealing core 104 moves towards the second direction B under the action of the pressure difference, the first elastic member 106 is compressed, and the hole 105 is opened, so that the first channel for gas to flow from the external environment towards the inside of the battery pack is opened, enabling the gas in the external environment to flow into the inside of the battery pack to achieve pressure balance.

[0070] As Figures 4A - 4B shown in is the exploded structural schematic diagram of the pressure relief valve 100 for the battery pack in another embodiment of the present application. Those skilled in the art should understand that although the structure of the valve 100 in the present application is for the battery pack of a vehicle, the valve 100 can also be applied to any suitable scenario that requires maintaining the pressure balance inside and outside the container.

[0071] Continue to refer to Figures 4A - 4B, in one or more embodiments of the present invention, a valve 100 is provided. The valve 100 includes a valve body bracket 110, a piston 120, a base 130, a valve cover 140, and a breathable membrane 170. Referring to FIG. 4, in an embodiment of the present invention, the valve body bracket 110 has a guide groove 111 extending in the longitudinal direction, a plurality of spaced ribs 112 extending from the guide groove 111 toward the inner peripheral wall 116, and a plurality of first ventilation holes 113 formed between every two adjacent spaced ribs 112, which can communicate with the external environmental gas. In addition, in an embodiment of the present invention, the valve body bracket 110 has an annular support portion 115 extending from the lower edge of the inner peripheral wall 116 toward the lower end of the valve body bracket 110. In an embodiment of the present invention, the support portion 115 can be used for the installation and support of an elastic member. The outer peripheral wall 117 of the valve body bracket 110 also has a groove 1171 extending along the circumferential direction of the outer peripheral wall 117. In an embodiment of the present invention, the groove 1171 is provided as two parallel grooves. It can be understood that the number of the grooves 1171 can be set according to the sealing requirements. Two sealing rings 118 are respectively pressed into the grooves 1171 so that when the valve body bracket 110 is snapped onto the valve cover 140 through a plurality of snap portions 114 spaced at the upper end, a sealing effect between the valve cover 140 and the valve body bracket 110 is achieved.

[0072] Continue to refer to Figures 4A - 4B , in an embodiment of the present invention, the guide groove 111 and the plurality of first ventilation holes 113 on the valve body bracket 110 are covered by the breathable membrane 170 from the upper end of the valve body bracket 110. The material of the breathable membrane 170 can be e-PTEF (expanded PTFE, expanded polytetrafluoroethylene), and the breathable membrane 170 can selectively prevent the passage of liquid and only allow the passage of gas. In an embodiment of the present invention, the breathable membrane 170 is welded to the upper end of the valve body bracket 110 by a welding ring 171 in an ultrasonic welding manner. It can be understood that the breathable membrane 170 can also be fixed to the upper end of the valve body bracket 110 by other connection methods such as bonding. In an embodiment of the present invention, the welding ring 171 can be made of polyethylene and / or fiberglass.

[0073] Then refer to Figures 4A - 4B And in combination with Figures 6A - 6B , the piston 120 has a piston body 121 and a compression core 122. Referring to Figures 6A - 6B It can be seen that the piston body 121 has a generally conical main body portion, which has an opening 1210 at the upper end and a circumferentially extending edge 1211 at the lower end. The edge 1211 has a protruding portion 1212 extending upward, and the protruding portion 1212 and the main body portion form a support groove 1213 in the circumferential direction. In an embodiment of the present invention, the support groove 1213 can be used for installing and supporting an elastic member. Continuing to combine Figures 6A - 6B, the compression core 122 has a cylindrical main body portion and an upper end portion with first spikes 1221. There is a flange 1222 extending in the circumferential direction between the upper end portion and the main body portion. When the compression core 122 is installed from the lower end portion of the piston main body 121, the upper end portion of the compression core 122 passes through the opening 1210 of the piston main body 121 and abuts against the opening 1210 through the flange 1222, thereby realizing the positioning of the piston main body 121 and the compression core 122. The piston main body 121 cooperates with the valve body bracket 110 through an elastic member - a second spring 1214 in the embodiment of the present invention. One end of the second spring 1214 is supported in the support portion 115 of the valve body bracket 110, and the other end is supported in the support groove 1213 of the piston main body 121. When they cooperate through the second spring 1214, the opening 1210 of the piston main body 121 is aligned with the guide groove 111 of the valve body bracket 110. Continue to refer to Figure 6B , in the embodiment of the present invention, the compression core 122 can be supported by a base 130. More specifically, the base 130 has a central support portion 131 and a plurality of extension arms 132 radially extending from the central support portion 131 to the inner edge of the annular main body. A plurality of second ventilation holes 133 are formed between every two extension arms 132, and the second ventilation holes 133 communicate with the internal gas of the battery pack. The elastic member - a first spring 1223 or a second spring 1214 in the embodiment of the present invention. Among them, the first spring 1223 is sleeved on the main body portion of the compression core 122. One end of it is supported by the central support portion 131 of the base 130, and the other end abuts against the flange 1222 of the compression core 122. The compression core 122 is biased by the first spring 1223 so that its front section passes through the opening 1210 and extends into the guide groove 111 of the valve body bracket 110.

[0074] Refer to Figure 4A , 4B and Figure 8 , in the embodiment of the present invention, the valve 100 further includes a bracket cap 150. The bracket cap 150 has a cap main body 151, an upper end opening 152, and a lower flange 153. In the embodiment of the present invention, the upper end opening 152 has a plurality of clamping portions 1521 spaced circumferentially. The plurality of clamping portions 1521 are formed by curling the edge of the upper end opening 152 upward. The plurality of clamping portions 1521 can be clamped into the clamping grooves of the valve body bracket 110 to engage with the valve body bracket 110. Combining Figure 9A As shown, the lower flange 153 of the bracket cap 150 curls downward and inward to form a clamping groove 1531 adapted to the lower edge 134 of the base 130. The clamping groove 1531 opens inward. The lower edge 134 of the base 130 can be clamped into the clamping groove 1531 of the bracket cap 150, so that the base 130 is connected to the valve body bracket 110 through the bracket cap 150.

[0075] Refer again to Figure 4A and 4B , wherein, the sealing gasket 160 can be snap-fitted into the card slot 1410 provided on the inner side of the lower end edge 141 of the valve cover 140, so as to achieve a sealing effect between the valve cover 140 and the housing of the battery pack when the valve cover 140 is connected to the housing of the battery pack through the threaded portion 1411. Combining Figure 9A , in the embodiment of the present invention, a second spike 143 is provided on the inner surface of the valve cover 140 facing the breathable film 170, and the second spike 143 extends from the inner surface of the valve cover 140 towards the breathable film 170. In the embodiment of the present invention, a reinforcing rib (not shown in the figure) is provided at the connection between the second spike 143 and the inner surface of the valve cover 140. The reinforcing rib is cross-shaped, and the bottom of the second spike 143 is arranged at the center of the cross shape, so that the second spike 143 has higher structural strength. In another embodiment of the present invention, the valve cover 140, the reinforcing rib and the second spike 143 can be integrally formed by molding. When the valve body bracket 110 is engaged with the valve cover 140, the length of the second spike 143 is less than the second gap H between the inner surface of the valve cover 140 and the breathable film 170 2 .

[0076] Next, referring to the cross-sectional views of the valve 100 shown in FIGS. 9A-9C, which show different operating states of the valve under different pressure differences caused by the internal pressure of the battery pack and the pressure of the external environment when the valve 100 is used on the housing of the battery pack.

[0077] First, refer to Figure 9A , in Figure 9A the cross-sectional view of the valve 100 shown, the valve 100 is generally in a pressure balance state. In the embodiment of the present invention, the pressure balance state means that the internal pressure of the battery pack is equal to the pressure of the external environment or the pressure difference formed between the two is within a threshold range so that the piston 120 will not generate displacement to open the gas passage under this pressure difference, thereby causing gas exchange between the inside and outside of the battery pack.

[0078] In Figure 9AIn the shown balanced state, the compression core 122 is biased by the second spring 1223 so that its front end extends into the guide groove 111, and the flange 1222 of the compression core 122 is biased against the opening 1210 of the piston body 121 to limit the length of the compression core 122 extending into the guide groove 111, and can close the opening 1210. In the closed state, the gas in the external environment cannot enter the interior of the battery pack through the valve 100. In an embodiment of the present invention, the piston body 121 is biased by the first spring 1214 against the upper surface of the lower edge 134 of the base 130, so that the gas inside the battery pack also cannot be discharged to the external environment through the valve 100. Therefore, the interior of the valve 100 is jointly composed of the valve body bracket 110, the piston 120, the base 130, and the bracket cap 150 to form a gas exchange chamber C for controlling the exchange of the gas inside the battery pack and the gas in the external environment. 2 , in the attached Figure 9A figure, the area of the gas exchange chamber C is roughly defined by a thick dashed line 2 . However, it should be understood that due to Figure 9A the complexity of the internal structure of the valve 100 shown in the cross-sectional view, the area of the gas exchange chamber C defined by the thick dashed line 2 is only exemplary and not a limitation of the present invention. This gas exchange chamber C 2 in the Figure 9A shown state can isolate the gas and moisture in the external environment from the interior of the battery pack, effectively preventing moisture or water vapor from entering the interior of the battery pack.

[0079] Next, referring to Figure 9A , as shown in the figure, in an embodiment of the present invention, in the state where the valve 100 is installed, the position of the window 142 on the side wall of the valve cover 140 in the longitudinal direction is above the breathable film 170. Thus, when moisture enters the interior of the valve cover through the window 142, it can be easily discharged outside the valve cover as shown by the dashed arrow, and generally will not affect the breathable film 170 or the gas entering the gas exchange chamber C of the valve 100 through the breathable film 170 2 .

[0080] Next, referring to Figure 9B, as shown in the figure, which shows the operating state of valve 100 when the gas pressure in the external environment is greater than the gas pressure inside the battery pack. In the embodiment of the present invention, the gas pressure in the external environment being greater than the gas pressure inside the battery pack means that the first pressure difference between the gas pressure in the external environment and the gas pressure inside the battery pack is greater than the first threshold for piston 120 to open. Specifically, when the first pressure difference is greater than the first threshold, under the action of the gas pressure in the external environment, compression core 122 moves towards the second direction B, so that the flange 1222 of compression core 122 disengages from the opening 1210 of piston body 121, thereby enabling the gas in the external environment to enter the inside of the battery pack through the first gas passage as shown by the dotted arrow. Specifically, the gas in the external environment passes through window 142 of valve cover 140 and through the first ventilation hole 113 of valve body support 110 covered by breathable membrane 170 into gas exchange chamber C 2 , and then enters through the gap between compression core 122 and opening 1210 and then enters the inside of the battery pack through the second ventilation hole 133 on base 130 to achieve the air pressure balance between the external environment and the inside of the battery pack.

[0081] Subsequently, refer to Figure 9C , as shown in the figure, which shows the operating state of valve 100 when the gas pressure inside the battery pack is greater than the gas pressure in the external environment. In the embodiment of the present invention, the gas pressure inside the battery pack being greater than the gas pressure in the external environment means that the second pressure difference between the gas pressure inside the battery pack and the gas pressure in the external environment is greater than the second threshold for piston 120 to open. Specifically, when the second pressure difference is greater than the second threshold, under the action of the gas pressure inside the battery pack, piston body 121 moves towards the first direction A, so that the edge 1211 of piston body 121 disengages from the upper surface of the lower edge 134 of base 130, enabling the gas inside the battery pack to be discharged into the external environment through the second gas passage as shown by the dotted arrow. Specifically, the gas inside the battery pack flows into gas exchange chamber C through the second ventilation hole 133 on base 130 from the gap between the edge 1211 of piston body 121 and the lower edge 134 of base 130, and then enters valve cover 140 through the first ventilation hole 113 of valve body support 110 and through breathable membrane 170, and then is discharged to the external environment through window 142 of valve cover 140, thereby maintaining the air pressure balance between the inside and the external environment of the battery pack.

[0082] Subsequently, continue to refer to Figure 9C , when the temperature inside the battery pack rises rapidly (for example, fast charging, high output power, etc.), the internal pressure may rise rapidly. When the third pressure difference with the external environment caused by the rapid rise in internal pressure exceeds the set third threshold, the edge 1211 of piston body 121 compared to Figure 9CThe shown working state is further lifted, so that the gap between the edge 1211 of the piston body 121 and the lower edge 134 of the base 130 becomes further larger (not shown in the figure), enabling the gas to enter the gas exchange chamber C more smoothly. 2 . In addition, as the piston body 121 is lifted, the compression core 122 also moves further in the first direction A under the action of the second spring 1214. As the compression core 122 moves in the first direction A, the first spike 1221 moves at least the first gap H towards the breathable membrane 170. 1 The distance and destroys the breathable membrane 170, causing ventilation holes to appear on the surface of the breathable membrane 170, so as to further improve the ventilation efficiency. As the internal pressure of the battery pack further rapidly increases, in order to further improve the exhaust efficiency, the breathable membrane 170 expands at least the second gap H in the first direction A as shown by the dashed line in Figure 9C . The height of the second spike 143 can further expand the ventilation holes on the basis that the first spike 1221 has damaged the breathable membrane 170, so as to further improve the exhaust efficiency, so that the internal gas can be discharged in time when the battery pack is in a situation of rapid internal pressure growth, ensuring the pressure balance between the inside and outside of the battery pack. 2 On the premise of being technically feasible, the technical features listed for different embodiments above can be combined with each other to form other embodiments within the scope of the present invention.

[0083] In the present application, the use of disjunctive connectives is intended to include conjunctive connectives. The use of definite or indefinite articles is not intended to indicate cardinality. Specifically, the reference to "the" object or "a" and "an" object is intended to mean one of the possible multiple such objects. In addition, the connective "or" can be used to convey co-existing features rather than mutually exclusive scenarios. In other words, the connective "or" should be understood to include "and / or". The term "comprising" is inclusive and has the same scope as "including".

[0084] The above embodiments are possible examples of the implementation manners of the present invention, and are only given to enable those skilled in the art to clearly understand the principle of the present invention. Those skilled in the art should understand that: the discussion for any embodiment above is only exemplary, and is not intended to imply that the scope (including the claims) disclosed by the embodiments of the present invention is limited to these examples; under the overall concept of the present invention, the technical features between the above embodiments or different embodiments can also be combined with each other, and many other variations in different aspects of the embodiments of the present invention as described above will be generated, and they are not provided in the specific implementation manners for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present invention shall be included in the protection scope required by the present invention.

[0085] The above embodiments are possible examples of the implementation manners of the present invention, and are only given to enable those skilled in the art to clearly understand the principle of the present invention. Those skilled in the art should understand that: the discussion for any embodiment above is only exemplary, and is not intended to imply that the scope (including the claims) disclosed by the embodiments of the present invention is limited to these examples; under the overall concept of the present invention, the technical features between the above embodiments or different embodiments can also be combined with each other, and many other variations in different aspects of the embodiments of the present invention as described above will be generated, and they are not provided in the specific implementation manners for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present invention shall be included in the protection scope required by the present invention.

Claims

1. A valve for a battery pack, the valve comprising: a valve body support having a first opening at one end and a second opening at the other end; a breathable membrane covering the first opening; A piston covers the second opening, the piston comprising a hole closed by an openable seal.

2. The valve according to claim 1, wherein: The sealing portion is at least one of a sealing core, a valve flap and a cutout.

3. The valve according to claim 1, wherein: The sealing core is biased toward a first direction by a first elastic member to close the hole.

4. The valve according to claim 1, wherein: The piston is biased toward a second direction by a second elastic member to cover the second opening.

5. The valve according to claim 3, wherein: The valve body support further includes a base, the second opening is arranged on the base, and the base supports the first elastic member.

6. The valve according to claim 3, wherein: The bottom of the piston has a supporting portion, and the first elastic member is supported by the supporting portion.

7. The valve according to claim 3, wherein: The valve body support has a guide groove, and the sealing core is biased by the first elastic member to partially pass through the hole and enter the guide groove.

8. The valve according to claim 3, wherein: Under the first pressure difference, the sealing core moves toward the second direction to open the hole to allow the gas of the external environment to flow into the interior of the battery pack shell.

9. The valve according to claim 2, wherein: Under a first pressure difference, the cutout is deformed to open the hole to allow gas from the external environment to flow into the interior of the battery pack housing.

10. The valve according to claim 2, wherein: Under a first pressure difference, the valve flap pivots about the flap axis to open the hole.

11. The valve according to claim 4, wherein: Under the second pressure difference, the piston moves toward the first direction to open the first opening to allow the gas in the shell of the battery pack to flow out.

12. The valve according to claim 3, wherein: The sealing core is a sealing plate covering the hole to close the hole.

13. The valve according to claim 7, wherein: The sealing core has a core body and a flange extending circumferentially outward from the core body, and the flange abuts against the hole under the bias of the first elastic member to seal the hole.

14. The valve according to claim 7, wherein: The sealing core has a first spike extending toward the air-permeable membrane, and the first spike is spaced apart from the air-permeable membrane with a first gap therebetween.

15. The valve according to claim 1, wherein: The valve further has a valve cover having a connection portion connected to the housing of the battery pack; The valve cover is connected to the upper end of the valve body support and covers the breathable membrane with a second gap; The valve cover has a second spike extending toward the gas-permeable membrane, and the length of the second spike is smaller than the second gap.

16. The valve according to claim 15, wherein The valve cover has at least one valve cover window arranged on the side wall. When the valve cover is engaged with the upper end of the valve body support, the valve cover window is located above the air permeable membrane in the longitudinal direction.

17. The valve according to claim 5, wherein: The base is detachably coupled to or integrally formed with the main body of the valve body support.

18. A method for controlling battery pack pressure, comprising: At least one gas exchange chamber is provided, the gas exchange chamber having a first channel and a second channel, the first channel and the second channel are respectively connected to the external environment and the interior of the housing of the battery pack; The gas exchange chamber is configured as follows: closing the first channel and the second channel when there is no pressure difference; When a first pressure difference exists, opening the first channel allows gas from the external environment to flow into the housing of the battery pack; and When a second pressure difference exists, the second channel is opened to allow the gas inside the housing of the battery pack to flow out to the external environment.

19. The method according to claim 18, wherein: Further including: Disposing a breathable membrane between the gas exchange chamber and the external environment to prevent moisture from entering the gas exchange chamber; and When the second pressure difference is greater than a threshold, the gas permeable membrane is destroyed to increase the gas flow rate of the second channel.

20. A battery pack having a valve mounted on a housing of the battery pack, the valve having: a valve body support having a first opening at one end and a second opening at the other end; a breathable membrane covering the first opening; A piston covers the second opening, the piston comprising a hole closed by an openable seal.

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