Pressure equalization device

Abstract

The application discloses a pressure balancing device configured to be fitted on a battery pack, comprising: a cover; a base; and a mounting piece made of metal, covering the fluid inlet from below the fluid inlet; wherein the mounting piece is connected with the base through a snap connection, and connected with the battery pack through a fastener. The mounting piece and the base are connected through the snap connection, which can facilitate the disassembly of the mounting piece. The mounting piece and the battery pack are fastened through the fastener, which ensures the stability of the connection and prevents the mounting piece from falling off the battery pack. Moreover, the mounting piece made of metal is also conducive to isolating any adverse heat effects or consequences caused by high-temperature gas / environment in the battery.

Description

Technical Field

[0001] This application relates to a pressure balancing device, and more particularly to a pressure balancing device for balancing the internal and external pressures of a battery pack. Background Technology

[0002] Battery packs generate heat during use, causing their temperature to rise. As the temperature of the gas inside the battery pack increases, the internal pressure also increases. If this gas is not released in time, it will affect the normal operation of the batteries. Therefore, pressure equalization devices are often installed on battery packs to release the gas inside and into the external environment, ensuring pressure balance inside and outside the battery pack.

[0003] Under normal circumstances, pressure equalization devices are typically made of plastic. When the temperature of the gas inside the battery pack becomes too high, the pressure equalization device may deform due to heat and detach from the battery pack, exposing the holes on the battery pack used to mount the pressure equalization device. Summary of the Invention

[0004] At least one object of this application is to provide a pressure balancing device capable of preventing detachment, the pressure balancing device being configured to be mounted on a battery pack, comprising: a cover; a base, a cavity formed between the base and the cover, the base having a fluid inlet located below and in fluid communication with the cavity; and a mounting member made of metal, the mounting member covering the fluid inlet from below, and the mounting member having a plurality of vent holes to allow gas inside the battery pack to enter the fluid inlet through the plurality of vent holes; wherein the mounting member is snap-fitted to the base and connected to the battery pack by fasteners.

[0005] According to the above, the mounting component includes at least one elastic arm, the elastic arm includes a hook, and the base includes at least one step; wherein the mounting component and the base are configured to achieve a snap-fit ​​connection through the hook and the corresponding step.

[0006] According to the above, the hook is formed by a spring attached to the elastic arm, the elastic arm including a window, the top end of the spring being connected to the top of the window, the bottom end of the spring forming a free end, and the spring being configured to be able to stretch and deform relative to the other parts of the elastic arm to move into or out of the window.

[0007] According to the above, the hook is formed by bending outward from the top of the elastic arm.

[0008] Based on the above, the mounting component includes at least one threaded hole for fastening to the battery pack via a fastener.

[0009] Based on the above, the mounting component includes at least one sleeve, and the at least one threaded hole is disposed within the at least one sleeve.

[0010] According to the above, the mounting component is flat, and the elastic arm and the at least one threaded hole are located near the outer peripheral edge of the mounting component.

[0011] According to the above, the pressure balancing device further includes: a heat insulation element made of metal, the heat insulation element being located below the mounting element and configured to cover the fluid inlet, the heat insulation element having several additional vent holes so that gas inside the battery pack can enter the fluid inlet through the several additional vent holes and the several vent holes.

[0012] Based on the above, the additional vents and the vents are staggered.

[0013] Based on the above, the battery pack is configured to be sandwiched between the mounting member and the heat insulation member, and the heat insulation member is connected to the mounting member by fasteners.

[0014] The mounting component of the pressure balancing device in this application is made of metal, such as sheet metal. The mounting component and the base are connected by a snap-fit ​​mechanism, facilitating easy disassembly of the mounting component. The mounting component and the battery pack are securely connected by fasteners to prevent the mounting component from detaching from the battery pack. Therefore, even when the temperature inside the battery pack is high, the mounting component and the battery pack maintain a stable connection, preventing plastic components from detaching from the battery pack and exposing the holes on the battery pack used to mount the pressure balancing device. Furthermore, the metal mounting component also provides a degree of insulation and heat dissipation, reducing heat accumulation and thus better preventing the transfer of high-temperature gases to the pressure balancing device. This helps to isolate any adverse thermal effects or consequences caused by high-temperature gases / environment within the battery. Attached Figure Description

[0015] Figure 1A and Figure 1B This is a perspective view of the pressure balancing device according to an embodiment of the present application when it is installed on the battery pack housing from two angles.

[0016] Figure 2 for Figure 1A A three-dimensional structural diagram of the pressure balancing device shown;

[0017] Figure 3A and Figure 3B for Figure 2The pressure balancing device shown is an exploded 3D structure diagram at two angles.

[0018] Figure 4A and Figure 4B for Figure 3A The three-dimensional structural diagram of the mounting components in the pressure balancing device shown in two angles;

[0019] Figure 5A for Figure 1B A cross-sectional view along line AA of the pressure balancing device mounted on the battery pack casing;

[0020] Figure 5B for Figure 1B A cross-sectional view along line BB of the pressure balancing device mounted on the battery pack housing;

[0021] Figure 6A and Figure 6B This is a perspective view of the pressure balancing device according to another embodiment of this application when it is installed on the battery pack housing from two angles.

[0022] Figure 6C for Figure 6A A bottom view of the pressure balancing device shown;

[0023] Figure 7A and Figure 7B for Figure 6A The pressure balancing device shown is an exploded 3D structure diagram at two angles.

[0024] Figure 8 Show Figure 6A The pressure balancing device mounted on the plate along Figure 6C A cross-sectional view of the CC line. Detailed Implementation

[0025] Various specific embodiments of this application will now be described with reference to the accompanying drawings, which form part of this specification. It should be understood that although terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "top," "bottom," "inner," and "outer," are used herein to describe various exemplary structural parts and elements, their use is merely for illustrative purposes and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this application can be arranged in different orientations, these terms indicating direction are illustrative only and should not be considered limiting.

[0026] Figure 1A and Figure 1BThis is a perspective view of the pressure balancing device 100 according to an embodiment of this application, mounted on a battery pack housing, from two angles. In the example shown, only a portion of the battery pack housing, specifically the plate 101 for mounting the pressure balancing device 100, is shown. Although the complete battery pack is not shown in the figure, it is understood that the area below the plate 101 is the internal space of the battery pack for accommodating the battery components, and the area above the plate 101 is in fluid communication with the outside air.

[0027] like Figure 1A and 1B As shown, the pressure balancing device 100 is generally cylindrical in shape and is mounted on the plate 101 of the battery pack casing. The pressure balancing device 100 allows fluid communication between the internal space of the battery pack and the external air. When the gas pressure inside the battery pack is greater than the gas pressure in the external environment, the gas inside the battery pack can be released to the external environment through the pressure balancing device 100, thus relieving pressure on the battery pack. However, during battery pack storage or use, there may be situations where the internal gas pressure of the battery pack is lower than the external gas pressure. In this case, gas from the external environment will also flow into the battery pack through the pressure balancing device.

[0028] In this embodiment, the pressure balancing device 100 is mounted on the plate 101 of the battery pack casing using fasteners (not shown). Specifically, the pressure balancing device 100 includes a main body 104 and a mounting member 109. The main body 104 includes a base 111 and a cover 112 connected together. The mounting member 109 is disposed below and connected to the base 111 of the main body 104. In this embodiment, the mounting member 109 has a bottom 107 that protrudes axially downward. Several elastic arms 115, for example, four elastic arms 115, are connected to the edge of the bottom 107 of the mounting member 109 that extend axially upward relative to the bottom 107 of the mounting member 109.

[0029] The plate 101 has a mounting hole 102 and several circular holes 105. The circular holes 105 are arranged around the mounting hole 102. As an example, four circular holes 105 are symmetrically arranged around the mounting hole 102. The shape of the mounting hole 102 on the plate 101 matches the shape of the bottom 107 of the mounting member 109. That is, the main body of the mounting hole 102 is used to receive the bottom 107 of the mounting member 109, so that when the mounting member 109 is installed in the mounting hole 102, the bottom 107 of the mounting member 109 can pass downward through the mounting hole 102 to extend below the plate 101. Furthermore, the edge of the mounting hole 102 has four ends to respectively receive the four resilient arms 115.

[0030] Mounting component 109 is provided with threaded hole 216 corresponding to the position of circular hole 105 on plate 101 (see...). Figure 2The positions of the circular holes 105 on plate 101 are configured such that when the bottom 107 of mounting member 109 passes through mounting hole 102, the four circular holes 105 respectively engage with the four threaded holes on mounting member 109 (see...). Figure 2 The threaded hole 216 in the mounting bracket 109 is aligned with the fastener (not shown in the figure) so that the fastener can pass through the circular hole 105 on the plate 101 and be fastened to the threaded hole 216 on the mounting bracket 109, thereby fastening the pressure balancing device 100 to the plate 101. As an example, the inner wall of the circular hole 105 may also have threads. In this embodiment, the mounting bracket 109 is made of a metal material, such as sheet metal. Of course, the mounting bracket 109 can also be made of other types of metal materials, as long as they have a certain high temperature resistance. Similarly, the fastener is also made of a metal material to make the connection between the fastener and the threaded hole 216 more reliable.

[0031] In this embodiment, the bottom of the mounting bracket 109 of the pressure balancing device 100 also has several vent holes 108, through which the inside of the battery pack can be fluidly connected with the inside of the pressure balancing device 100. The top of the cover 112 has several vent holes 113, through which the inside of the pressure balancing device 100 can be fluidly connected with the outside air. Thus, the inside of the battery pack and the outside air can be fluidly connected through the pressure balancing device 100.

[0032] Figure 2 It shows Figure 1A and Figure 1B A three-dimensional structural diagram of the pressure balancing device 100 is provided to illustrate its external structure. For example... Figure 2 As shown, the base 111 of the pressure balancing device 100 includes a button portion 214 that is generally cylindrical in shape. A mounting member 109 is engaged with the lower part of the button portion 214, and a cover 112 is engaged with the top of the button portion 214. Thus, the cover 112, the base 111, and the mounting member 109 can be connected together.

[0033] Mounting member 109 includes four circumferentially spaced plates 219, four sidewalls 217 extending downward from the inside of each plate 219, and a bottom 107 connected to the bottom end of each sidewall 217. Four threaded holes 216 are provided on a corresponding plate 219. Four resilient arms 115 extend upward from the edge of the bottom 107 and are positioned at intervals corresponding to adjacent plates 219. The resilient arms 115 are capable of engaging with the base 111 through snap-fit ​​holes 271. As a specific example, in the circumferential direction of mounting member 109, the four resilient arms 115 are spaced apart from the four threaded holes 216 such that each resilient arm 115 is located between two adjacent threaded holes 216.

[0034] In such Figure 2In the illustrated embodiment, the diameter of plate 219 is smaller than the bottom diameter of base 111. In the radial direction, a circumferentially arranged annular sealing ring 218 is provided between the bottom of base 111 and plate 219, surrounding plate 219. The sealing ring 218 abuts against the upper surface of plate 101 (see [reference]). Figure 6A and Figure 6B (as shown), to achieve a sealed installation between the pressure balancing device 100 and the battery pack housing.

[0035] Figure 3A and Figure 3B This is an exploded three-dimensional structural view of the pressure balancing device 100 from two angles, used to show the approximate shape and relative position of the internal components of the pressure balancing device 100. (See attached image.) Figure 3A and Figure 3B As shown, in addition to the cover 112, base 111, and mounting member 109, the pressure balancing device 100 also includes a venting assembly disposed inside the pressure balancing device 100 and located within the receiving space formed by the cover 112 and base 111 (see Figure 109). Figure 6A and Figure 6B The cavity 580 shown is within the battery pack. The venting assembly allows air from the external environment to enter the battery pack while preventing liquids from entering. It also rapidly connects the battery pack's interior to the external environment when the internal pressure is too high. In this embodiment, the venting assembly includes a venting membrane 320, a separator 321, a cover 322, and a drying component 323. In other embodiments, the venting assembly can be any other structure that achieves the same function.

[0036] like Figure 3A and Figure 3BAs shown, the top 351 of the cover 112 faces the external environment, and a vent 113 is provided through the top 351 to discharge gas in the cavity 580 to the external environment. The inner surface of the top 351 of the cover 112 also has inwardly protruding spikes 325. The sidewall 352 of the cover 112 has several fasteners 353 and corresponding slots 355. Each slot 355 is located on the sidewall 352 between the top 351 and the corresponding fastener 353, and is recessed inward from the outer surface of the sidewall 352. The button portion 214 of the base 111 has a corresponding number of inwardly protruding bosses 362, the size of which matches the size of the slots 355. The bosses 362 can be installed by engaging with the fasteners 353 and the slots 355, allowing the cover 112 to be snapped into place with the base 111. As an example, there are four fasteners 353, four slots 355, and four bosses 362. In this embodiment, when the base 111 rotates relative to the cover 112, the bosses 362 can move along the upper surface of the corresponding fasteners 353 until they enter the slots 355 above the fasteners 353. After that, the base 111 can no longer rotate relative to the cover 112, thereby connecting the cover 112 and the base 111 together.

[0037] The breathable membrane 320 is a generally circular sheet located below and close to the top 351 of the cover 112. Made of a waterproof and breathable material, the breathable membrane 320 allows for ventilation between the battery pack's interior and the external environment while preventing liquids from entering the battery pack, thus providing dustproof, waterproof, and breathable protection. As an example, the breathable membrane 320 is a composite of plastic and non-woven fabric. In this embodiment, the breathable membrane 320 is a composite of ePTFE and non-woven fabric, offering better breathability compared to a breathable membrane made solely of ePTFE.

[0038] The separator 321 is located below the breathable membrane 320, dividing the cavity 580 between the cover 112 and the base 111 into an upper cavity 581 and a lower cavity 582 (see [reference]). Figure 6A and Figure 6BThe separator 321 includes a connecting flange 331, an elastic portion 332, and a support portion 333. The support portion 333 is disposed on the elastic portion 332, and the connecting flange 331 protrudes outward from the outer surface of the elastic portion 332. In this embodiment, the elastic portion 332 is made of an elastic material so that it can elastically deform, thereby moving the support portion 333 relative to the cover 112. As a specific example, the elastic portion 332 is made of a rubber material. In this embodiment, the elastic portion 332 is generally cylindrical, and its cylindrical wall has pleats 327 that can expand or contract. The pleats 327 can expand or contract along the direction of elastic deformation to further move the support portion 333 relative to the cover 112.

[0039] The support portion 333 has a ventilation hole 335 penetrating through it, and a breathable membrane 320 is disposed on the support portion 333 and covers the ventilation hole 335. As an example, the breathable membrane 320 and the support portion 333 have a certain connection strength, allowing them to move together. In this embodiment, the breathable membrane 320 is molded onto the support portion 333 using processes such as injection molding, which not only facilitates processing but also ensures a certain connection strength between the breathable membrane 320 and the separator 321. The support portion 333 also has a receiving hole 336 penetrating approximately at its center, which is used to receive the spikes 325 on the cover 112 when the support portion 333 moves relative to the cover 112 to a specific position. As an example, the support portion 333 encloses the top end of the cylindrical elastic portion 332.

[0040] The connecting flange 331 is an annular ring extending outward from the outer surface of the elastic portion 332 and is connected to the bottom end of the elastic portion 332. The bottom surface of the connecting flange 331 is provided with an annular sealing edge 338 protruding toward the base 111. The connecting flange 331 is used to connect with the base 111. In this embodiment, the separator 321 is sealed to the base 111 through the annular sealing edge 338.

[0041] For ease of manufacturing, in this embodiment, the connecting flange 331, the elastic portion 332, and the supporting portion 333 of the separator 321 are integrally formed from rubber material. When the connecting flange 331 is made of elastic material, the annular sealing edge 338 can provide an elastic seal. Of course, in other embodiments, only the elastic portion 332 may be made of elastic material.

[0042] The cover 322 is generally umbrella-shaped and is disposed between the separator 321 and the base 111 to prevent the drying component 323 from flowing along with the airflow passing through it. The cover 322 includes a top plate 345 and an insertion portion 346, one end of which is connected to the bottom of the top plate 345, and the other end is connected to the base 111. In this embodiment, the top plate 345 has a perforated channel 347 that allows airflow to pass through but prevents the drying component 323 from passing through.

[0043] The bottom inner side of the button portion 214 of the base 111 is provided with a sealing groove 342 and a snap-fit ​​hole 271. The position of the sealing groove 342 corresponds to the annular sealing edge 338 of the separator 321, so as to facilitate the installation of the separator 321 and the base 111. The position and size of the snap-fit ​​hole 271 are provided to correspond to the elastic arm 115 of the mounting member 109, so as to facilitate the installation of the mounting member 109 and the base 111. The hole wall of the snap-fit ​​hole 271 is provided with a step 339 extending into the hole, and the top of the elastic arm 115 is provided with a hook portion 383, which is used to snap onto the step 339 to connect the mounting member 109 to the bottom of the base 111. In this embodiment, the hook portion 383 is formed by a spring piece 372 connected to the elastic arm 115. The specific structure of the spring piece 372 on the elastic arm 115 and the step 339 in the snap-fit ​​hole 271 will be combined Figures 4A-4B Detailed description.

[0044] The base 111 also includes a cylindrical body 375, which extends downward from the middle of the button portion 214. The cylindrical body 375 is generally cylindrical in shape and coaxial with the side wall of the button portion 214. In this embodiment, for ease of processing, the cylindrical body 375 and the button portion 214 of the base 111 are integrally formed. A receiving space 341 is formed on the inner side of the cylindrical body 375, and the top plate 345 of the cover 322 closes the receiving space 341 from above. The receiving space 341 is used to receive the drying component 323. The bottom of the cylindrical body 375 has a fluid inlet 379, and the bottom 107 of the mounting member 109 covers the fluid inlet 379 from below, so that the air inside the battery pack can first pass through the vent hole 108 of the mounting member 109, then enter the fluid inlet 379 and flow into the interior of the cylindrical body 375, then flow through the drying component 323 and into the cavity 580. As a more specific example, the cylinder 375 has a central cylinder 340, within which mounting holes 343 are formed for connection with the insertion portion 346 of the cover 322. The periphery of the cylinder 340 of the cylinder 375 is provided with several vent holes 378, which form fluid inlets 379. These vent holes 378 are generally partially annular in shape, arranged in several concentric rings, each ring comprising several spaced-apart vent holes 378.

[0045] In the receiving space 341 between the cylinder wall of the cylinder 340 and the cylinder body 375, several partitions 349 are also provided, and the drying component 323 is received between adjacent partitions 349. As a specific example, there are four partitions 349. In this embodiment, the four partitions 349 are arranged in a radiating pattern around the cylinder 340. One end of each partition 349 is connected to the cylinder 340, and the other end passes through the cylinder wall of the cylinder body 375 and protrudes outward from the outer surface of the cylinder wall to form a rib 376. The four ribs 376 are used to abut against the side wall 217 of the mounting member 109 to strengthen the connection between the mounting member 109 and the base 111.

[0046] Several blind holes 344 are provided at the bottom of the button portion 214 of the base 111, and the positions of the blind holes 344 correspond to the positions of the threaded holes 216 on the mounting member 109. As an example, a clearance hole 389 is also provided on the outside of the snap-fit ​​hole 271. The clearance hole 389 allows for a certain amount of deformation space in the hole wall of the snap-fit ​​hole 271 when the elastic arm 115 is inserted into the snap-fit ​​hole 271. In this embodiment, both the blind holes 344 and the clearance holes 389 are formed by recessing upward from the bottom of the button portion 214, but neither needs to extend beyond the bottom of the button portion 214.

[0047] The mounting plate 219 of the mounting member 109 is provided with a number of sleeves 373 corresponding to the threaded holes 216, each sleeve 373 extending upward from the top surface of the plate 219. The threaded holes 216 are provided on the inner surface of the corresponding sleeves 373. The sleeves 373 can be inserted into the blind holes 344 of the base 111 to facilitate the positioning connection between the mounting member 109 and the base 111.

[0048] The drying component 323 is made of silica gel desiccant, alumina gel desiccant, or molecular sieve desiccant, and is used to absorb moisture in the pressure balancing device 100 and prevent moisture in the gas from the external environment from entering the battery pack. In this embodiment, the drying component 323 includes multiple desiccant particles, which are spherical or hemispherical. In other embodiments, the drying component 323 may also be made into other shapes and structures.

[0049] Blind holes 344, snap-fit ​​holes 271, and clearance holes 389 are arranged around the bottom of the button portion 214 around the cylinder body 375. In the embodiment shown, blind holes 344 and snap-fit ​​holes 271 are spaced apart in the circumferential direction of the cylinder body 375, and clearance holes 389 are positioned close to snap-fit ​​holes 271 to allow deformation space for snap-fit ​​holes 271. In this embodiment, a step 339 extends inward from the inner surface of the outer sidewall of snap-fit ​​hole 271 in the radial direction of the cylinder body 375, and clearance holes 389 are also provided on the outer side of snap-fit ​​holes 271. Thus, when the elastic arm 115 of the mounting member 109 is inserted into the snap-fit ​​hole 271, the elastic arm 115 can deform the sidewall of the snap-fit ​​hole 271 toward the clearance hole 389 by pressing the step 339, facilitating the smooth insertion of the elastic arm 115 into the snap-fit ​​hole 271, and the hook portion 383 is connected to the step 339 by a snap fastener.

[0050] Figure 4A and Figure 4B The three-dimensional structural diagram of the mounting component 109 is shown at two different angles, in which Figure 4A This shows the view from above. Figure 4B This shows the angle viewed from below. For example... Figure 4A and Figure 4B As shown, the vent holes 108 on the bottom 107 of the mounting member 109 are generally partially annular in shape, arranged in several concentric rings at intervals, with each ring including several spaced vent holes 108. In this embodiment, the position of the vent holes 108 matches the position of the vent holes 378 on the bottom of the base 111, so that when the mounting member 109 is connected to the base 111, air can flow through the vent holes 108 and 378 without being blocked.

[0051] The four plates 219 of the mounting member 109 are generally fan-shaped. Four sleeves 373 are each disposed on the upper surface of one plate 219, and four threaded holes 216 are each disposed on the inner surface of one sleeve 373. Four elastic arms 115 are disposed between adjacent plates 219. As an example, the threaded holes 216 and elastic arms 115 are approximately evenly spaced in the circumferential direction of the mounting member 109. The positions of the four sleeves 373 correspond to the positions of the four blind holes 344 on the base 111, so that the sleeves 373 can be inserted into the corresponding blind holes 344.

[0052] Four elastic arms 115 are connected to the bottom of the side wall 217. The positions of the four elastic arms 115 correspond to the positions of the four snap-fit ​​holes 271 on the base 111, so that the elastic arms 115 can be snapped into the corresponding snap-fit ​​holes 271. The bottom 107 of the side wall 217 is provided with partition grooves 463 on the left and right sides of each elastic arm 115. Each elastic arm 115 includes a bottom 464 and an arm 465. The bottom 464 extends outward from the edge of the bottom 107 of the side wall 217, and the arm 465 extends upward from the outer edge of the bottom 464. The partition grooves 463 are provided so that only the bottom 464 of each elastic arm 115 is connected to the bottom 107, while the top end of the arm 465 away from the bottom 464 forms a free end. This arrangement allows the elastic arm 115 to have a certain degree of elasticity, and its arm 465 can expand and contract relative to the side wall 217. Four hooks 383 are respectively disposed at the top of the arm portion 465 of the corresponding elastic arm 115. In this embodiment, the hooks 383 are formed by spring pieces 372. Specifically, the top end of the arm portion 465 of each elastic arm 115 has a window 484, the top end of each spring piece 372 is connected to the top of the window 484 of the corresponding elastic arm 115, and the bottom end of each spring piece 372 forms a free end and extends outward at an angle from the top end to the bottom end. This arrangement allows the spring piece 372 to also have a certain degree of elasticity, and its bottom end can move in and out of the window 484 relative to the other parts of the arm portion 565.

[0053] In this embodiment, the base 111 has four blind holes 344, the mounting member 109 has four sleeves 373 and four threaded holes 216, and their positions are correspondingly arranged so that the mounting member 109 can be positioned and installed under the base 111 as expected. This ensures that the positions of the vent holes 378 of the base 111 and the mounting member 109 are also corresponding, thereby ensuring that the inside of the battery pack and the outside can be fluidly connected through the vent holes 108, 378 and the cavity 580 in sequence. In other embodiments, the number of blind holes 344, sleeves 373 and threaded holes 216 can be set accordingly.

[0054] Figure 5A and Figure 5B They are shown respectively Figure 1B A cross-sectional view of the pressure balancing device 100 mounted on plate 101 along line AA and line BB. Figure 5A and Figure 5BAs shown, the pressure balancing device 100 can be fastened to the plate 101 of the battery pack housing using fasteners. The bottom of the plate 219 of the mounting member 109 and the button portion 214 of the base 111 abuts against the upper surface of the plate 101. The side wall 217, bottom 107 of the mounting member 109, and the cylinder 375 of the base 111 extend at least partially into the mounting hole 102. The sealing ring 218 tightly abuts against the upper surface of the plate 101 to prevent external dust particles or liquids from entering the battery pack below the plate 101 through the gap between the pressure balancing device 100 and the plate 101. The circular hole 105 on the plate 101 is aligned with the threaded hole 216 in the sleeve 373 of the mounting member 109 to achieve a positioning connection between the plate 101 and the pressure balancing device 100 using fasteners.

[0055] refer to Figure 5B As shown, the sleeve 373 of the mounting member 109 is inserted into the blind hole 344 of the base 111, and the hook 383 of the elastic arm 115 of the mounting member 109 is inserted into the snap-fit ​​hole 271 of the base 111, so that the mounting member 109 and the base 111 are connected by snap-fit.

[0056] When the mounting piece 109 is installed onto the base 111, the elastic arm 115 is inserted into the corresponding snap-fit ​​hole 271 in the base 111 from bottom to top. After the outer surface of the spring piece 372 of the elastic arm 115 contacts the step 339 in the snap-fit ​​hole 271, continuing to insert the elastic arm 115 into the snap-fit ​​hole 271 will cause the step 339 in the snap-fit ​​hole 271 to compress the spring piece 372, causing the spring piece 372 to contract and deform inward until the bottom end of the spring piece 372 passes over the step 339. When the step 339 no longer compresses the spring piece 372, the spring piece 372 returns to its original position. Figure 5B In the initial state shown, the bottom end of the spring piece 372 abuts against the upper surface of the step 339, preventing the mounting member 109 from moving downward relative to the base 111. Furthermore, the bottom 107 of the mounting member 109 abuts against the bottom of the base 111, preventing the mounting member 109 from moving upward relative to the base 111. During the elastic deformation of the spring piece 372, the clearance hole 389 provides deformation space for the snap-fit ​​hole 271, allowing the sidewall of the snap-fit ​​hole 271 to deform towards the clearance hole 389, reducing the pressure exerted by the step 339 on the spring piece 372. In this embodiment, both the arm 465 of the elastic arm 115 and the spring piece 372 can undergo a certain degree of elastic deformation. On the other hand, the wall of the snap-fit ​​hole 271 can also undergo a certain degree of elastic deformation, allowing the elastic arm 115 to be smoothly inserted into the snap-fit ​​hole 271, thereby allowing the mounting member 109 to be installed below the base 111.

[0057] When removing the mounting piece 109 from the base 111, the operator presses the arm 465 of the elastic arm 115 of the mounting piece 109, causing the arm 465 to retract and deform inward until the bottom end of the spring piece 372 no longer abuts against the upper surface of the step 339. Under the action of external force, the elastic arm 115 can be pulled out from the snap-fit ​​hole 271, thereby removing the mounting piece 109 from the base 111.

[0058] Continue to refer to Figure 5A The base 111 forms a cavity 580 enclosed by a cover 112. A separator 321 divides the cavity 580 into an upper cavity 581 and a lower cavity 582. The upper cavity 581 is used for fluid communication with the external environment, and the lower cavity 582 is used for fluid communication with the inside of the battery pack. The upper cavity 581 and the lower cavity 582 are fluidly connected through a ventilation hole 335 and a receiving hole 336 on the support 333 and a breathable membrane 320.

[0059] Specifically, the bottom end face of the side wall of the cover 112 of the pressure balancing device 100 abuts against the upper surface of the connecting flange 331 of the separator 321, so that the annular sealing edge 338 of the separator 321 is pressed against the inner side of the bottom of the button portion 214 of the base 111, and sealed with the sealing groove 342. Thus, the separator 321 divides the cavity 580 into an upper cavity 581, approximately between the inside of the button portion 214 of the base 111 and the outside of the separator 321, and closed by the cover 112, and a lower cavity 582, approximately formed by the cylinder 375 and the interior of the separator 321. A breathable membrane 320 is connected above the support 333 and is also located in the upper cavity 581. The upper cavity 581 communicates with the external environment through the vent 113 on the cover 112, so that the air pressure in the upper cavity 581 is approximately the same as the air pressure of the external environment. The lower cavity 582 is connected to the inside of the battery pack through the vent 108 at the bottom of the side wall 217 of the mounting 109 and the fluid inlet 379 at the bottom of the cylinder 375 of the base 111, so that the pressure in the lower cavity 582 is approximately the same as the air pressure inside the battery pack.

[0060] When the internal air pressure of the battery pack is lower than the external air pressure (i.e., the air pressure in the lower cavity 582 is lower than the air pressure in the upper cavity 581), air from the external environment will enter the battery pack through the pressure balancing device 100. Specifically, the air from the external environment first enters the upper cavity 581 of the pressure balancing device 100 through the vent 113 on the cover 112, and then flows down to the lower cavity 582 through the ventilation holes 335 and receiving holes 336 on the support portion 333 of the breathable membrane 320 and the separator 321. The air entering the lower cavity 582 then flows through the perforated channel 347 on the top plate 345 of the cover 322 to the receiving space 341 and comes into contact with the drying component 323, and finally flows into the battery pack through the fluid inlet 379 and the vent 108.

[0061] When the battery cells inside the battery pack are in operation, the internal temperature of the battery pack will rise, causing the internal air pressure to increase to a level greater than that of the external environment (i.e., the air pressure in the lower cavity 582 is greater than that in the upper cavity 581). The hot air inside the battery pack will flow through the pressure balancing device 100 in the opposite direction to the above, that is, it will first enter the lower cavity 582, then pass through the support part 333 into the upper cavity 581, and after passing through the breathable membrane 320 in the upper cavity 581, it will be released into the external environment.

[0062] In certain situations, when the internal air pressure of the battery pack increases to a certain level—that is, when the pressure difference between the upper cavity 581 and the lower cavity 582 equals or exceeds a predetermined value—the elastic portion 332 of the separator 321 will elastically deform and elongate. The elastic portion 332 drives the support portion 333 to move upwards until the spike 325 on the inner side of the cover 112 pierces the ventilated membrane 320 and is received by the receiving hole 336. At this time, the battery pack rapidly depressurizes through the holes in the ventilated membrane 320, thereby quickly bringing the pressure in the upper cavity 581 and the lower cavity 582 to a balance. As an example, the predetermined value of the pressure difference can be set according to specific needs, and the predetermined value can be met by adjusting the height of the elastic deformation of the elastic portion 332 of the separator 321 and the distance between the spike 325 and the ventilated membrane.

[0063] Those skilled in the art will understand that the elastic part 332 in this embodiment may not be a pleated deformable structure, but may be set as other deformable structures, as long as the pressure difference between the upper cavity and the lower cavity is greater than a predetermined value, it can drive the support part 333 and the breathable membrane 320 to move toward the spike part 325.

[0064] In this embodiment, to ensure that the pressure balancing device 100 can balance the pressure between the inside of the battery pack and the external environment under normal circumstances, so that the inside of the battery pack is approximately at atmospheric pressure, the breathable membrane 320 needs to have good air permeability. In some special cases, the pressure balancing device 100 needs to be able to quickly relieve the pressure inside the battery pack, for example, by setting spikes 325 to pierce the breathable membrane 320 to quickly release pressure. Although the breathable membrane 320 may deform to some extent and bulge towards the spikes 325 when the pressure difference between the inside and outside of the breathable membrane 320 is large, due to material limitations, deformation is generally difficult when the breathable membrane 320 has good air permeability.

[0065] The pressure balancing device 100 of this embodiment includes a separator 321. The breathable membrane 320 is moved by the elastic deformation of the elastic portion 332 of the separator 321, without relying on the elastic deformation of the breathable membrane 320 itself to be punctured by the spike 325. Thus, under certain conditions, the pressure balancing device 100 can quickly depressurize the inside of the battery pack. Furthermore, the breathable membrane 320 can also be made of a material with better breathability. In the embodiments of this application, the breathable membrane 320 is made of a composite of plastic and non-woven materials, which meets its breathability requirements.

[0066] Those skilled in the art will understand that, although the cavity 580 is provided with a drying component 323 and a deformable separator 321 in this embodiment, depending on the specific type of battery pack, these components may not be provided in the cavity 580, or other components may be provided. It is only necessary to ensure that when the pressure balancing device 100 is installed on the plate 101, the air on the upper and lower sides of the plate 101 can be connected through the cavity 580, and that when the pressure difference between the upper and lower sides of the plate 101 is too large, the pressure balancing device 100 can quickly balance the pressure on both sides.

[0067] Figure 6A and Figure 6B This is a perspective view of the pressure balancing device 600 according to another embodiment of this application, when mounted on the battery pack housing, from two angles. Figure 6C This is a bottom view of the pressure balancing device 600. (See attached image.) Figures 6A-6C As shown, the pressure balancing device 600 is generally rectangular in shape and is also used to mount on the plate 601 of the battery pack casing, allowing fluid communication between the internal space of the battery pack and the outside air through the pressure balancing device 600. The pressure balancing device 600 includes a cover 612 and a base 611 connected together, and a mounting member 609 and a heat insulation member 691 connected below the base 611, wherein the heat insulation member 691 is located below the plate 601, and the rest of the pressure balancing device 600 is located above the plate 601.

[0068] The cover 612 has several vent holes 613, and the side wall of the base 611 has several vent holes 699. Through the vent holes 613 and 699, the outside air above the plate 601 can communicate with the fluid inside the pressure balancing device 600. The base 611 also has a fluid inlet 779 (see...). Figure 7B The mounting element 609 and the heat insulation element 691 cover the fluid inlet 779 from below, and the mounting element 609 has several vent holes 608, while the heat insulation element 691 also has several additional vent holes 692. Therefore, the interior of the battery pack below the plate 601 can also be in fluid communication with the interior of the pressure balancing device 600.

[0069] The heat insulation component 691 has four round holes 693 at its four corners, which are connected to the threaded holes 716 on the mounting component 109 (see...). Figure 7A and 7B The positions are aligned so that the thermal insulation 691 and the mounting 109 can be fastened together by fasteners (not shown in the figure).

[0070] In this embodiment, compared to the pressure balancing device 100, the pressure balancing device 600 is additionally provided with a generally square plate-shaped heat insulation member 691. The base 611 and the mounting member 609 no longer have a downwardly protruding shape; the mounting member 609 is generally flat and located above the plate 601, and the heat insulation member 691 is located below the plate 601 (see [reference]). Figure 8 (As shown). Furthermore, the heat insulation component 691, the mounting component 609, and the fasteners are all made of metal. This arrangement ensures that the gas on both sides of the pressure balancing device 600 connecting plate 601 is kept within safe limits, while also providing insulation through the heat insulation component 691 and the mounting component 609. This helps to isolate the high-temperature gas or adverse thermal effects or consequences caused by the environment inside the battery pack, and avoids affecting other parts of the pressure balancing device 600 located outside the battery pack.

[0071] In this embodiment, both the vent 608 on the mounting component 609 and the additional vent 692 on the heat insulation component 691 are square holes, and the vent 608 and the additional vent 692 are staggered. This ensures proper ventilation while better preventing high-temperature gas from inside the battery pack from entering the pressure balancing device 600.

[0072] Figure 7A and Figure 7B for Figure 6A The three-dimensional structure diagram of the pressure balancing device 600 in the middle at two angles after an explosion. Figure 7A This shows the view from above. Figure 7B This shows the angle viewed from below. For example... Figure 7A and Figure 7BAs shown, the base 611 of the pressure balancing device 600 is generally a through-type rectangular tube. A cover 612 is fitted over the top of the base 611, and a mounting member 609 and a heat insulation member 691 are connected to the bottom of the base 611. In this embodiment, the cover 612 and the base 611 are engaged together via a receiving hole 755 on the cover 612 and a boss 762 on the outer side wall of the base 611. The mounting member 609 and the base 611 are engaged together via an elastic arm 715 on the mounting member 609 and a step 739 on a transverse wall 786 inside the base 611. Furthermore, the heat insulation member 691 is fastened to the mounting member 609 with fasteners. Thus, the cover 612, the base 611, the mounting member 609, and the heat insulation member 691 can be connected together to form the pressure balancing device 600.

[0073] Specifically, the base 611 has a transverse wall 786 with a through square hole 787 forming a fluid inlet 779 on the bottom surface of the transverse wall 786. The base 611 includes an edge 785 extending downward around the transverse wall 786, with a sealing ring 718 positioned at the bottom of the edge 785. A mounting member 609 and a heat insulation member 691 cover the fluid inlet 779 from below the transverse wall 786, with the mounting member 609 positioned approximately at the top of the edge 785 and the heat insulation member 691 positioned approximately at the bottom of the edge 785. Thus, the mounting member 609 and the heat insulation member 691 are spaced apart to ensure that although the vent holes on the mounting member 609 and the heat insulation member 691 are staggered, fluid flow is not obstructed, thus ensuring effective ventilation.

[0074] Mounting member 609 is generally square flat plate in shape. It includes sleeves 773 located at four corners and multiple elastic arms 715, for example, six elastic arms 715, arranged around its outer periphery. The sleeves 773 extend into a square hole 787, each sleeve 773 having a threaded hole 716. The elastic arms 715 also extend into the square hole 787 and have hooks 783 at their tops for engaging with steps 739 on the transverse wall 786 of the base 611. That is, when mounting member 609 covers the fluid inlet 779 from below, the hooks 783 of the elastic arms 715 engage with the steps 739, preventing mounting member 609 from moving downwards relative to the base 611, and the mounting member 609 is blocked by the transverse wall 786, preventing it from moving upwards. Thus, mounting member 609 can be snapped together with the base 611. In this embodiment, the hooks 783 are formed by bending the top ends of the elastic arms 715 outwards.

[0075] Similar to the pressure balancing device 100, the pressure balancing device 600 also includes a receiving space disposed between the cover 612 and the base 611 (see Figure 8The venting component within the cavity 880 (shown) allows air from the external environment to enter the battery pack while preventing liquids from entering. It also quickly connects the internal and external environments when the internal pressure of the battery pack becomes excessive. Unlike the pressure balancing device 100, in this embodiment, there are two sets of venting components arranged side-by-side. Each set includes a separator 721, a breathable membrane 720, and a spring 732.

[0076] The partition 721 is generally square in shape and covers the square hole 787 from above. A seal 738 is provided at the bottom edge of the partition 721. The seal 738 abuts against the transverse wall 786 of the edge of the square hole 787, such that the partition 721 generally divides the cavity 880 between the cover 612 and the base 611 into an upper cavity 881 and a lower cavity 882 (see...). Figure 8 The upper cavity 881 is used for fluid communication with the external environment, and the lower cavity 882 is connected to the fluid inlet 779 on the transverse wall 786, thereby communicating with the internal fluid of the battery pack. The separator 721 is provided with a ventilation hole 735, through which the upper cavity 881 and the lower cavity 882 are connected, and a breathable membrane 720 covers the ventilation hole 735 to block dust, water, etc. from passing through.

[0077] Spring 732 is supported between cover 612 and partition 721. Normally, spring 732 is compressed to provide downward support to partition 721, keeping it in a position that covers the square hole 787 and seal 738 abuts against the transverse wall 786. When partition 721 is subjected to a larger upward force, spring 732 can be further compressed, causing partition 721 to move upward away from the position covering the square hole 787. This allows the upper cavity 881 and lower cavity 882 to no longer communicate through the vent membrane 720 and vent 735 on partition 721, but directly through the square hole 787.

[0078] To better guide the movement of the separator 721, two downward-extending posts 798 are provided on the inner top of the cover 612. Two springs 732 are respectively sleeved on the corresponding post 798. Furthermore, each separator 721 has a downward-extending post 796 on its lower side, and two sleeves 795 arranged side-by-side within a square hole 787. The inner wall of each sleeve 795 forms a hole 794, which accommodates a corresponding post 796. The post 796 can move up and down relative to the hole 794. To prevent the separator 721 from displacing relative to the square hole 787 other than vertically, corresponding convex-concave fitting structures 797 can also be provided on the post 796 and the hole 794.

[0079] Figure 8 Show Figure 6A The pressure balancing device 600 mounted on plate 601 along Figure 6C A cross-sectional view of the CC line. (e.g.) Figure 8 As shown, after the pressure balancing device 600 is installed on the plate 601, the mounting part 609 and the heat insulation part 691 are located on the upper and lower sides of the plate 601, respectively. The sealing ring 718 on the base 611 abuts against the upper surface of the plate 601 to prevent external dust particles or liquids from entering the battery pack below the plate 601 through the gap between the pressure balancing device 600 and the plate 601.

[0080] The interior of the base 611 forms a cavity 880 sealed by the cover 612. The separator 721 divides the cavity 880 into an upper cavity 881 and a lower cavity 882. The upper cavity 881 is used for fluid communication with the external environment, and the lower cavity 882 is used for fluid communication with the inside of the battery pack. The upper cavity 881 and the lower cavity 882 are fluidly connected through a ventilation hole 735 and a breathable membrane 720.

[0081] Similar to the pressure balancing device 100, when the internal air pressure of the battery pack is lower than the external air pressure (i.e., the air pressure in the lower cavity 882 is lower than the air pressure in the upper cavity 881), air from the external environment will enter the upper cavity 881 through the vent 613 on the cover 612 and the vent 699 on the base 611 in sequence. Then, it will flow into the lower cavity 882 after passing through the breathable membrane 720 and the ventilation hole 735. It will then flow out from the fluid inlet 779 and flow through the vent 608 on the mounting part 609 and the additional vent 692 on the heat insulation part 691 in sequence before flowing into the battery pack.

[0082] When the battery cells inside the battery pack are in operation, the internal temperature of the battery pack will rise, causing the internal air pressure to increase to a level greater than that of the external environment (i.e., the air pressure in the lower cavity 882 is greater than that in the upper cavity 881). The hot air inside the battery pack will flow in the opposite direction to the above through the pressure balancing device 600, that is, first enter the lower cavity 882, then enter the upper cavity 881 through the breathable membrane 720 and the ventilation hole 735, and be released to the external environment through the vent hole 613 on the cover 612 and the vent hole 699 on the base 611.

[0083] In certain situations, when the internal air pressure of the battery pack increases to a certain level—that is, when the pressure difference between the lower cavity 882 and the upper cavity 881 increases to a certain level, for example, equal to or greater than the preset force of the spring 732, allowing the spring 732 to be compressed—the separator 721 will move upward and no longer cover the square hole 787. At this time, the battery pack rapidly releases pressure through the square hole 787, thereby quickly bringing the pressure in the upper cavity 881 and the lower cavity 882 to a balance.

[0084] In some embodiments of this application, the cover and base of the pressure balancing device are made of plastic, which not only reduces the weight of the pressure balancing device but also simplifies the manufacturing process, allowing it to be produced through molding and reducing production costs. The mounting components and fasteners of the pressure balancing device are made of metal, such as sheet metal. The mounting components and base are connected by a snap-fit ​​connection, facilitating the removal of the mounting components. The mounting components and battery pack are securely connected by fasteners to prevent the mounting components from detaching from the battery pack. Therefore, even when the temperature inside the battery pack is high, the mounting components and battery pack maintain a stable connection, preventing the plastic components from detaching from the battery pack and exposing the holes on the battery pack used to mount the pressure balancing device.

[0085] Furthermore, the metal mounting components also provide a degree of insulation and heat dissipation, reducing heat accumulation and thus better preventing high-temperature gases from being transferred to the pressure equalization device. This helps to isolate any adverse thermal effects or consequences caused by high-temperature gases / environment within the battery.

[0086] In some embodiments of this application, the pressure balancing device further includes a metal heat insulation component, which is connected to the mounting component via metal fasteners. This ensures a stable connection between the heat insulation component and the mounting component and the battery pack. The heat insulation component, with vent holes staggered from those on the mounting component, further enhances insulation and heat dissipation without compromising ventilation. This helps isolate the battery pack from adverse thermal effects or consequences caused by high-temperature gases / environment within the battery pack, preventing impact on other parts of the pressure balancing device located outside the battery pack.

[0087] Although this application will be described with reference to the specific embodiments shown in the accompanying drawings, it should be understood that the pressure balancing device of this application can have many variations without departing from the spirit, scope, and context of the teachings of this application. Those skilled in the art will also recognize that different ways of modifying the structure of the embodiments disclosed in this application fall within the spirit and scope of this application and the claims.

Claims

1. A pressure balancing device, the pressure balancing device being configured to be mounted on a battery pack, characterized in that... include: build; A base, wherein a cavity is formed between the base and the cover, and the base has a fluid inlet located below the cavity and in fluid communication with it; as well as The mounting component, which is a separate part from the base and is made of metal, covers the fluid inlet from below and has several vent holes to allow gas inside the battery pack to enter the fluid inlet through the vent holes. The mounting component is connected to the base by a snap-fit ​​connection and to the battery pack by fasteners.

2. The pressure balancing device according to claim 1, characterized in that: The mounting component includes at least one elastic arm, the elastic arm includes a hook, and the base includes at least one step; The mounting component and the base are configured to be snap-fit ​​connected via the hook and the corresponding step.

3. The pressure balancing device according to claim 2, characterized in that: The hook is formed by a spring attached to the elastic arm, which includes a window. The top end of the spring is connected to the top of the window, and the bottom end of the spring forms a free end. The spring is configured to expand and contract relative to the rest of the elastic arm to move into or out of the window.

4. The pressure balancing device according to claim 2, characterized in that: The hook is formed by bending outward from the top of the elastic arm.

5. The pressure balancing device according to claim 2, characterized in that: The mounting component includes at least one threaded hole for fastening to the battery pack by a fastener.

6. The pressure balancing device according to claim 5, characterized in that: The mounting component includes at least one sleeve, and the at least one threaded hole is disposed within the at least one sleeve.

7. The pressure balancing device according to claim 5, characterized in that: The mounting component is flat, and the elastic arm and the at least one threaded hole are located near the outer peripheral edge of the mounting component.

8. The pressure balancing device according to claim 7, characterized in that: The pressure balancing device also includes: A heat insulation element, made of metal, is located below the mounting element and configured to cover the fluid inlet. The heat insulation element has several additional vent holes to allow gas inside the battery pack to enter the fluid inlet through the additional vent holes and the vent holes.

9. The pressure balancing device according to claim 8, characterized in that: The additional vents and the vents are staggered.

10. The pressure balancing device according to claim 8, characterized in that: The battery pack is configured to be sandwiched between the mounting member and the heat insulation member, and the heat insulation member is connected to the mounting member by fasteners.

11. The pressure balancing device according to claim 1, characterized in that: The cover and the base are made of plastic.

Images