pressure relief device

Abstract

A pressure relief device comprises a shell, a valve core and an elastic member. The elastic member is clamped between the shell and the top of the valve core, so that the valve core has a first position and a second position. The valve core can move between the first position and the second position relative to the shell. In the first position, the valve core is supported by the shell, the bottom of the valve core covers the shell through hole, and the shell through hole can be connected to the shell cavity through the valve core through hole; in the second position, the valve core leaves the shell to form a pressure relief channel between the bottom of the valve core and the shell, and the shell through hole can be connected to the shell cavity through the pressure relief channel. When the valve core moves from the first position to the second position, the elastic member is compressed, and the restoring elastic force of the elastic member can make the valve core move from the second position to the first position. The pressure relief device of the present application can not only meet the requirements of sealing testing of the battery pack with the pressure relief device installed, but also realize the function of centralized pressure relief without destroying the structure of the pressure relief device.

Description

Technical Field

[0001] The present application relates to a pressure relief device, and in particular, to a pressure relief device for use in a battery pack. Background Art

[0002] Batteries generate heat during use, causing the battery pack to heat up. When the temperature inside the battery pack rises, the gases inside expand due to the heat. If the gases inside the battery pack are not discharged promptly and accumulate inside the battery pack, the internal pressure will increase, affecting the normal operation of the battery pack. Therefore, to ensure the safe use of the battery, it is often necessary to install a pressure relief device on the battery pack. When the pressure inside the battery pack exceeds a predetermined value, the pressure relief device automatically opens to discharge the accumulated gas inside the battery pack and reduce the excessive pressure. Summary of the Invention

[0003] The purpose of the present application is to provide a pressure relief device that can not only meet the need for sealing testing of a battery pack with the pressure relief device installed, but also realize the function of centralized pressure relief without destroying the structure of the pressure relief device.

[0004] In order to achieve the above-mentioned purpose, the present application provides a pressure relief device, which includes a shell, a valve core and an elastic member. The shell has a shell cavity inside, and the shell is provided with a shell through-hole, and the shell through-hole is connected to the internal space of the component to be relieved. The valve core is arranged in the shell cavity, and the valve core includes a top, a bottom and a valve core through-hole extending from the top to the bottom. A breathable film covering the valve core through-hole is provided on the top of the valve core, and the valve core has a first position and a second position, and is configured to be able to move between the first position and the second position relative to the shell. The elastic member is clamped between the shell and the top of the valve core. wherein, in the first position, the valve core is supported by the housing, the bottom of the valve core covers the housing through hole, and the housing through hole can be communicated with the housing cavity through the valve core through hole; in the second position, the valve core leaves the housing to form a pressure relief channel between the bottom of the valve core and the housing, and the housing through hole can be communicated with the housing cavity through the pressure relief channel; and wherein, when the valve core moves from the first position to the second position, the elastic member is compressed, and the restoring elastic force of the elastic member can enable the valve core to move from the second position to the first position.

[0005] As described above in the pressure relief device, the valve core further comprises an upper guide member provided on the top of the valve core; an upper guide hole is provided on the housing, and the upper guide hole can receive the upper guide member to guide the movement of the valve core.

[0006] As described above in the pressure relief device, the distal end of the upper guide member extends to the outside of the shell through the upper guide hole, wherein an operating portion is provided on the distal end, and the operating portion is configured to be able to pull the valve core from the first position to the second position through the operating portion.

[0007] As described above in the pressure relief device, the elastic member is a spring, and the spring is sleeved on the upper guide member.

[0008] As described above in the pressure relief device, the valve core also includes several lower guide members arranged on the bottom of the valve core; several lower guide grooves are provided on the hole wall of the shell through hole of the shell, and the several lower guide grooves can correspondingly receive the several lower guide members to guide the movement of the valve core.

[0009] As described above in the pressure relief device, the housing further comprises a boss arranged around the outer periphery of the housing, the boss having a joint surface around the outer periphery of the housing, the joint surface facing away from the component to be relieved.

[0010] As described above, the pressure relief device further includes a valve core sealing ring, which is arranged between the bottom of the valve core and the shell. When the valve core is in the first position, the valve core sealing ring can sealably connect the bottom of the valve core and the shell.

[0011] As described above in the pressure relief device, the valve core sealing ring is arranged in the shell sealing groove surrounding the shell through hole; a valve core sealing groove is provided at the bottom of the valve core, and the valve core sealing groove is configured as follows: when the valve core is in the first position, the valve core sealing ring is clamped between the shell sealing groove and the valve core sealing groove.

[0012] As described above, in the pressure relief device, when the valve core is in the first position, the elastic member applies a first elastic pressure to the valve core. When the valve core is subjected to a force that is opposite to the direction of the first elastic pressure and is greater than the first elastic pressure, the valve core can leave the housing and move to the second position.

[0013] As described above, the pressure relief device is further provided with an air vent on the shell, and the air vent is configured to connect the shell cavity with the external environment, so that when the valve core is in the second position, the pressure relief channel can connect the internal space of the component to be relieved with the external environment.

[0014] The present application sets an elastic member in the pressure relief device, and uses the elastic properties of the elastic member itself to open and close the pressure relief channel in the pressure relief device, thereby realizing the centralized pressure relief function of the pressure relief device. Since the elastic properties of the elastic member are sustainable, the pressure relief device of the present application can be reused in the battery pack, and a single installation can achieve multiple pressure relief functions. In addition, the structural setting of the pressure relief device of the present application enables the external airtightness detection tooling to perform airtightness detection on the battery pack installed with the pressure relief device, solving the problem that when the pressure relief device needs to be fixedly installed from the inside of the battery pack, it is impossible to perform airtightness detection on the battery pack installed with the pressure relief device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of a pressure relief device 100 according to an embodiment of the present application;

[0016] Figure 2 yes Figure 1 An enlarged view of the battery pack 110 at the position of the pressure relief device 100;

[0017] Figure 3 yes Figure 2 A perspective view of the pressure relief device 100;

[0018] Figure 4 yes Figure 2 A perspective view of the middle battery pack housing 102;

[0019] Figure 5 yes Figure 3 An exploded view of the pressure relief device 100;

[0020] Figure 6A and 6B yes Figure 5 A perspective view of the base 114 at different viewing angles;

[0021] Figure 7 Shown Figure 5 The structure after the base 114 and the mounting base 109 are installed together;

[0022] Figure 8 yes Figure 5 The structure after the valve core 201, the elastic member 202 and the breathable film 203 are assembled together;

[0023] Figure 9 Shown Figure 2 A longitudinal cross-sectional view of the pressure relief device 100 when the valve core 201 is in the first position;

[0024] Figure 10 Shown Figure 2 FIG. 1 is a longitudinal cross-sectional view of the pressure relief device 100 at another angle when the valve core 201 is in the second position. DETAILED DESCRIPTION

[0025] Various specific embodiments of the present application will be described below with reference to the accompanying drawings that form a part of this specification. It should be understood that although terms indicating directions, such as "front", "rear", "up", "down", "left", "right", etc., are used in this application to describe various example structural parts and elements of the present application, these terms are used here only for the purpose of convenience of explanation and are determined based on the example orientations shown in the accompanying drawings. Since the embodiments disclosed in this application can be set in different directions, these directional terms are only for illustration and should not be regarded as limitations. Where possible, the same or similar figure numbers used in this application refer to the same parts.

[0026] Figure 1 Schematic diagram of a battery pack 110 using the pressure relief device 100 according to an embodiment of the present application. Figure 1 As shown, the battery pack 110 is roughly rectangular. In other embodiments, the battery pack 110 can also be of other shapes. The battery pack 110 includes a battery pack housing 102 and a pressure relief device 100. The interior of the battery pack housing 102 forms a storage space for accommodating battery cells (not shown). The upper side of the pressure relief device 100 faces the external environment 120, and the lower side faces the component to be pressure-relieved. In this embodiment, the component to be pressure-relieved is the battery pack 110. The pressure relief device 100 is installed on the battery pack housing 102 to connect the storage space inside the battery pack housing 102 with the external environment 120. In the embodiment of the present application, the pressure relief device 100 needs to be fixed to the battery pack housing 102 from the inside of the battery pack 110 using fasteners. When the gas pressure in the internal space 103 of the battery pack 110 is greater than the gas pressure in the external environment, the pressure relief device 100 can relieve the pressure in the internal space 103 of the battery pack 110.

[0027] Figure 2 yes Figure 1 An enlarged view of the battery pack 110 at the location of the pressure relief device 100. Figure 2As shown, the upper part of the battery pack shell 102 is the external environment 120, and the lower part of the battery pack shell 102 is the internal space 103 of the battery pack 110. The pressure relief device 100 is arranged above the battery pack shell 102. The pressure relief device 100 includes a shell 111, and the outer surface of the shell 111 is exposed to the external environment 120. The shell 111 is provided with a plurality of air holes 113 for connecting the external environment 120 with the inner side of the shell 111. In this embodiment, the plurality of air holes 113 are respectively in the shape of long strips and are distributed on the top surface and side surfaces of the shell 111. The bottom of the pressure relief device 100 is connected to the internal space 103 of the battery pack 110, so when the gas pressure in the internal space 103 of the battery pack 110 is greater than or equal to a predetermined value, the pressure relief device 100 can release the gas in the internal space 103 to the external environment 120 in a concentrated manner, thereby relieving the pressure of the battery pack 110.

[0028] Figure 3 yes Figure 2 The perspective view of the pressure relief device 100 shows the structure viewed from the bottom upward. Figure 3 As shown, the pressure relief device 100 is roughly in the shape of a cylindrical button. The pressure relief device 100 also includes a mounting base 109, which is arranged at the bottom of the housing 111. The mounting base 109 is provided with a plurality of mounting holes 311, and the plurality of mounting holes 311 are arranged at intervals in the circumferential direction of the mounting base 109. The pressure relief device 100 can be fixedly mounted on the battery pack housing 102 through the plurality of mounting holes 311. In this embodiment, four mounting holes 311 are provided on the mounting base 109. In other embodiments, other numbers of mounting holes 311 may also be provided.

[0029] Figure 4 yes Figure 2 A perspective view of the battery pack housing 102. Figure 4 As shown, the battery pack housing 102 includes a battery pack communicating hole 401 and a plurality of battery pack mounting holes 402. The battery pack communicating hole 401 is used to ensure that the bottom of the pressure relief device 100 is connected to the internal space 103 of the battery pack 110, and the plurality of battery pack mounting holes 402 are used to cooperate with the installation of the pressure relief device 100 on the battery pack housing 102. The opening size of the battery pack communicating hole 401 is much larger than the opening size of the plurality of battery pack mounting holes 402, and the plurality of battery pack mounting holes 402 are arranged at intervals around the outer circumference of the battery pack communicating hole 401. The number of battery pack mounting holes 402 matches the number of mounting holes 311 on the pressure relief device 100. Corresponding to the four mounting holes 311 on the pressure relief device 100 of this embodiment, four battery pack mounting holes 402 are also provided on the battery pack housing 102.

[0030] Figure 5 yes Figure 3 Exploded view of the pressure relief device 100. Figure 5As shown, in addition to the shell 111 and the mounting seat 109, the pressure relief device 100 also includes a valve core 201, an elastic member 202, a breathable film 203, a mounting seat 109, a valve core sealing ring 204 and a shell sealing ring 205. The shell 111 includes a cover 112 and a base 114. The cover 112 includes a top plate 503, a side wall 502 and several snap-fit ​​portions 504. The top plate 503 is roughly circular, and some of the multiple vents 113 are arranged through the top plate 503. The side wall 502 is roughly cylindrical and extends downward from the lower surface of the top plate 503. The cross-section of the side wall 502 is roughly circular, and the side wall 502 and the top plate 503 are arranged cocentrically. In addition, since the diameter of the cross-section of the side wall 502 is smaller than the diameter of the top plate 503, the outer surface of the side wall 502 is located on the inner side of the outer periphery of the top plate 503. Several latching portions 504 protrude outward from the outer surface of the side wall 502, and each latching portion 504 is identical in size and shape. The latching portions 504 are located at the same height on the side wall 502 and are spaced apart along the outer circumference of the side wall 502. Each latching portion 504 includes an upper surface 506, a lower surface 508, a front surface 509, a rear surface 510, and side surfaces 507. The upper surface 506 and the lower surface 508 are disposed opposite each other, located above and below the latching portion 504, respectively. The upper surface 506 is spaced a distance from the lower surface of the top plate 503 to form a latching slot 505. The lower surface 508 is planar and flush with the bottom end surface of the side wall 502. The front surface 509 and the rear surface 510 are disposed opposite each other, located on the left and right sides of the latching portion 504, respectively. The side surfaces 507 are arcuate and generally parallel to the outer surface of the side wall 502. The upper surface 506 includes an inclined portion 530 and a flat portion 531. The inclined portion 530 extends obliquely upward from the top of the front surface 509, and the flat portion 531 extends from the upper end of the inclined portion 530 in a direction parallel to the top plate 503. This arrangement allows the slot 505 to have a larger accommodating space near the front surface 509 and a smaller accommodating space near the rear surface 510. An upper guide hole wall 518 is provided in the middle of the cover 112. The upper guide hole wall 518 protrudes from the upper surface of the cover 112 and extends in a direction perpendicular to the upper surface of the cover 112. An upper guide hole 218 is formed on the inner side of the upper guide hole wall 518, which extends through the thickness of the cover 112. The upper guide hole 218 can guide the movement of the valve core 201 from the top of the pressure relief device 100.

[0031] The base 114 includes an intermediate platform 515, an upper extension wall 513, and a lower support portion 514. The intermediate platform 515 is generally in the shape of a circular plate. The upper extension wall 513 extends upward from the upper surface of the intermediate platform 515, and the lower support portion 514 extends downward from the lower surface of the intermediate platform 515. The cross-sections of the upper extension wall 513 and the lower support portion 514 are generally circular, and the intermediate platform 515, the upper extension wall 513, and the lower support portion 514 are arranged cocentrically. In the embodiment of the present application, the cross-sectional diameters of the upper extension wall 513 and the lower support portion 514 are both smaller than the diameter of the boss 106. Therefore, the outer walls of the upper extension wall 513 and the lower support portion 514 are both located inward of the boss 106. The outer peripheral edge of the intermediate platform 515 protrudes outward relative to the outer walls of the upper extension wall 513 and the lower support portion 514 to form an annular boss 106. The upper surface of the boss 106 forms a joint surface 107 of the pressure relief device 100 . An external airtightness testing tool can be sealed and combined with the pressure relief device 100 through the joint surface 107 to achieve airtightness testing of the battery pack 110 .

[0032] The upper extension wall 513 is generally cylindrical, and another portion of the plurality of air holes 113 is disposed on the upper extension wall 513. The upper extension wall 513 and the intermediate platform 515 together form an upper base cavity 516 for accommodating the valve core 201, the elastic member 202, the breathable membrane 203, and the valve core sealing ring 204. The upper base cavity 516 can also at least partially accommodate the cover 112. The inner wall of the upper extension wall 513 is provided with a plurality of inwardly projecting protrusions 511. The dimensions of the protrusions 511 match those of the retaining grooves 355, allowing the protrusions 511 to be mounted in conjunction with the retaining portions 353, thereby enabling the cover 112 to be snap-fitted and connected to the base 114. In this embodiment, the retaining portions 353, retaining grooves 355, and protrusions 511 are all four in number. In other embodiments, other numbers of protrusions 511 may also be configured.

[0033] The elastic member 202 is a spring, which is formed by spring steel spirally rotating in an axial direction. The elastic member 202 has an axially compressible structure. The spiral elastic member 202 forms an elastic member cavity 520 on its inner side, and the elastic member cavity 520 extends along the axial direction of the elastic member 202. In this embodiment, the elastic member 202 is composed of a spring. In other embodiments, it can also be made of other elastic materials. The breathable film 203 is a roughly annular thin sheet. The breathable film 203 can prevent liquid from penetrating and allow gas to pass through, thereby playing a waterproof and breathable role in the pressure relief device 100. In this embodiment, the breathable film 203 is made of PTFE material. In other embodiments, it can also be made of other materials.

[0034] The valve core 201 includes a valve core body 340, an upper guide 212 and a plurality of lower guides 215. Figure 5As shown, the cross-section of the valve core body 340 is roughly circular. The upper guide member 212 is roughly cylindrical and extends upward from the center of the upper surface of the valve core body 340, located at the top 221 of the valve core 201. An operating portion 216 is provided at the top of the upper guide member 212. The operating portion 216 is configured to cooperate with the airtightness testing operation of an external airtightness testing tool. In this embodiment, the operating portion 216 includes a groove 346 and a receiving hole 345. The groove 346 is annular and arranged around the outer circumference of the upper guide member 212, and the annular groove 346 is spaced a distance from the end surface of the top end of the upper guide member 212. The receiving hole 345 extends downward from the end surface of the top end (distal end 223) of the upper guide member 212. The receiving hole 345 does not extend through the length of the upper guide member 212, and the receiving hole 345 and the groove 346 do not intersect. Several lower guide members 215 are located at the bottom 222 of the valve core 201. Each lower guide member 215 is elongated and extends downward from the lower surface of the valve core body 340. In this embodiment, the valve core 201 includes four lower guide members 215, but other embodiments may also include a different number of lower guide members 215. The valve core body 340 includes a valve core inner ring 344, a valve core outer ring 342, and multiple valve core strips 343. The valve core inner ring 344 and the valve core outer ring 342 are both annular in shape. The valve core inner ring 344 is located inside the valve core outer ring 342 and is cocentric with the valve core inner ring 344 and the valve core outer ring 342. The valve core inner ring 344 surrounds the outer circumference of the upper guide member 216, while the valve core outer ring 342 is located near the outer edge of the valve core body 340. The valve core strips 343 extend radially along the valve core body 340, with one end connected to the valve core inner ring 344 and the other end connected to the valve core outer ring 342. Multiple valve core strips 343 are spaced apart circumferentially around the valve core body 340, with valve core through-holes 217 defined between adjacent valve core strips 343. Each valve core through-hole 217 is enclosed by the valve core inner ring 344, the valve core outer ring 342, and two adjacent valve core strips 343. The valve core 201 of this embodiment has eight valve core strips 343, evenly spaced along the circumference of the valve core body 340, forming eight valve core through-holes 217.

[0035] The valve core seal 204 and the housing seal 205 are both annular and made of an elastic material. In some embodiments, the elastic material is silicone or rubber. The valve core seal 204 is used to achieve a sealed connection between the valve core 201 and the base 114, while the housing seal 205 is used to achieve a sealed connection between the base 114 and the battery pack housing 102.

[0036] The mounting base 109 is used to connect to the component 101 to be relieved of pressure and includes a base plate 219, four mounting hole walls 312, and four elastic arms 521. In this embodiment, the mounting base 109 is made of a metal material, such as sheet metal. Metal is resistant to high temperatures, and the provision of the metal mounting base 109 ensures that the pressure relief device 100 is secured to the component 101 to be relieved of pressure even at relatively high temperatures. The base plate 219 is flat, and the four mounting hole walls 312 are spaced apart near the outer edge of the base plate 219. Each mounting hole wall 312 is roughly cylindrical and extends upward from the base plate 219. A mounting hole 311 is formed on the inner side of the cylindrical mounting hole wall 312. The mounting hole 311 extends perpendicularly to the base plate 219 and passes through the mounting base 109. Four elastic arms 521 extend upward from the base plate 219, each elastic arm 521 being located between two adjacent mounting hole walls 312. The elastic arm 521 includes an extension portion 522 and a bent portion 523, which are used to cooperate with the connection between the base 114 and the mounting seat 109. The extension portion 522 extends upward perpendicular to the bottom plate 219, and the bent portion 523 is formed by bending downward and outward at an angle from the end of the extension portion 522. Since one end of the elastic arm 521 is a fixed end and the other end is a free end, the elastic arm 521 has a certain degree of elasticity, and its free end can roughly expand and contract along the radial direction of the bottom plate 219. In this embodiment, the elastic arm 521 is formed integrally with the bottom plate 219. Figure 5 As shown, the base plate 219 and the four elastic arms 521 can be made of a circular flat plate. First, at the quartered position of the circular flat plate, four strips of equal thickness are cut radially from the radial middle position of the circular flat plate to the outer edge position. Subsequently, the four strips are bent upwards respectively so that the four strips are perpendicular to the flat plate. Next, the end areas of the four strips are bent obliquely downward and outwards respectively to form the bending portions 523 of the four elastic arms 521. The above arrangement enables the base plate 219 of the mounting seat 109 to be divided into four sector-shaped plates 559 by the four elastic arms 521, and the four mounting hole walls 312 are respectively arranged on the upper surfaces of the four sector-shaped plates 559. A plurality of mounting seat through holes 524 are provided at the center position of the base plate 219, and each mounting seat through hole 524 is roughly arc-shaped. The plurality of mounting seat through holes 524 are arranged at intervals to form a plurality of concentric rings. The four elastic arms 521 and the four mounting hole walls 312 are arranged in pairs and spaced apart around the outer sides of the plurality of mounting seat through holes 524 .

[0037] Figure 6A and 6B yes Figure 5 The base 114 is a three-dimensional image at different viewing angles. Figure 6A and 6BAs shown, the base 114 is provided with a housing through-hole 213. The housing through-hole 213 is located in the middle of the intermediate platform 515 and extends through the intermediate platform 515 and the lower support portion 514, thereby enabling communication between the housing through-hole 213 and the upper chamber 516 of the base. The wall of the housing through-hole 213 is provided with several lower guide grooves 301 and several engaging grooves 603, each of which is in communication with the housing through-hole 213. The lower guide grooves 301 extend axially along the base 104, so that each lower guide groove 301 can receive a corresponding lower guide member 215 of the valve core 201 to guide the movement of the valve core 201. A clamping member 604 is provided in the clamping groove 603. The clamping member 604 is in the shape of a step extending from the inner wall of the clamping groove 603 toward the housing through hole 213, so that the elastic arm 521 in the mounting seat 109 can be connected to the clamping member 604 in a corresponding clamping groove 603. Corresponding to the four lower guide members 215 and the four elastic arms 521 in this embodiment, the base 114 is also provided with four lower guide grooves 301 and four clamping grooves 603. Figure 6A and 6B As shown, the four lower guide grooves 301 and the four engaging grooves 603 are arranged in pairs. That is, there is a lower guide groove 301 and an engaging groove 603 in each of two adjacent grooves in the circumferential direction of the shell through hole 213. Figure 6A As shown, a housing sealing groove 302 is provided on the upper surface of the middle platform 515. The housing sealing groove 302 is annular and is provided around the outer periphery of the housing through hole 213 for receiving the valve core sealing ring 204.

[0038] The base 114 has several blind holes 605 on the bottom surface of the lower support portion 514. These blind holes 605 are spaced around the periphery of the housing through-hole 213 and are designed to receive the mounting hole walls 312 on the mounting base 109. Four blind holes 605 are also provided on the base 114, corresponding to the four mounting hole walls 312 on the mounting base 109. These four blind holes 605 are located outside the four lower guide grooves 301 and, like the four lower guide grooves 301, are spaced between two adjacent engaging grooves 603. The blind holes 605 are recessed inward from the bottom surface of the lower support portion 514 but do not penetrate the lower support portion 514. The base 114 also has a housing sealing ring receiving groove 517 on the bottom surface of the lower support portion 514 for receiving the housing sealing ring 205. The housing sealing ring receiving groove 517 is annular and located at the outer edge of the lower support portion 514.

[0039] Figure 7 Shown Figure 5 The structure after the base 114 and the mounting seat 109 are installed together. Figure 7As shown, the mounting base 109 is roughly installed at the position of the housing through hole 213 of the base 114. The multiple mounting base through holes 524 on the bottom plate 219 of the mounting base 109 are exactly located in the housing through hole 213 of the base 114. The four elastic arms 521 on the mounting base 109 are respectively abutted against the four clamping members 604 in the four clamping grooves 603 of the base 114 through the bent portions 523.

[0040] Figure 8 yes Figure 5 The valve core 201, the elastic member 202 and the breathable film 203 are assembled together to form the valve core assembly 800. Figure 8 As shown, the size of the elastic member cavity 520 in the elastic member 202 matches the size of the upper guide member 212 of the valve core 201, so that the elastic member 202 can be sleeved on the outer side of the upper guide member 212 through the elastic member cavity 520. The breathable film 203 covers the top 221 of the valve core 201. Figure 5 and Figure 8 As can be seen, the inner edge of the annular breathable film 203 covers the valve core inner ring 344 of the valve core 201, just avoiding the upper guide member 212 of the valve core 201. The outer edge of the annular breathable film 203 covers the valve core outer ring 342 of the valve core 201, so that the breathable film 203 can cover all valve core through-holes 217 in the valve core body 340. In this embodiment, the breathable film 203 is fixed to the upper surface of the valve core 201 by ultrasonic welding. In other embodiments, the breathable film 203 can also be connected to the valve core 201 using other connection methods, such as adhesive bonding or secondary injection molding.

[0041] Figure 9 Shown Figure 2 A longitudinal cross-sectional view of the pressure relief device 100 when the valve core 201 is in the first position, Figure 10 Shown Figure 2 A longitudinal cross-sectional view of the pressure relief device 100 at another angle when the valve core 201 is in the second position. Figure 9 and Figure 10 As shown, the cover 112 covers the upper portion of the base cavity 516 of the base 114, so that the housing cavity 501 is formed inside the housing 111, and the valve core assembly 800 is disposed in the housing cavity 501. Figure 5 and Figure 10As can be seen, to install the cover 112 on the base 114, the cover 112 can first be placed above the upper cavity 516 of the base, and then the cover 112 can be rotated relative to the base 114. As the cover 112 rotates, the protrusion 511 on the inner wall of the base 114 can enter the slot 355 above the latch portion 353 in the cover 112. The rotation direction of the cover 112 allows the protrusion 511 to enter the slot 355 from the front surface 509 of the latch portion 353. The structural arrangement of the slot 505 with a larger accommodation space near the front surface 509 and a smaller accommodation space near the rear surface 510 further facilitates the snap connection between the protrusion 511 and the slot 355. Once the protrusion 511 is fully inserted into the slot 355, the cover 112 can no longer rotate relative to the base 114, thus achieving a snap-fit ​​installation between the cover 112 and the base 114.

[0042] The mounting base 109 is mounted on the bottom of the housing 111. Figure 10 As shown, the four mounting hole walls 312 of the mounting seat 109 are respectively accommodated in the four blind holes 605 at the bottom of the housing 111. Figure 9 As shown, the bent portions 523 at the ends of the four elastic arms 521 of the mounting base 109 are respectively in contact with the upper surfaces of the four clamping members 604 of the housing 111. Figure 9 and Figure 10 It can be seen that the mounting base 109 can be fixedly mounted on the housing 111 through the limitation of the blind hole 605 of the housing 111 and the snap fit between the elastic arm 521 and the snap fit member 604 .

[0043] The housing seal ring 205 is accommodated in the housing seal ring receiving groove 517 at the bottom of the housing 111. Through the interference fit between the housing seal ring 205 and the housing seal ring receiving groove 517, the pressure relief device 100 can form a sealed connection with the battery pack housing 102. In addition, the provision of the housing seal ring 205 can also prevent external dust particles or liquids from entering the interior of the battery pack 110. Figure 10As shown, the four mounting holes 311 in the pressure relief device 100 are aligned with the four battery pack mounting holes 402 on the battery pack housing 102, respectively. This allows the user to sequentially insert fasteners through the battery pack mounting holes 402 and the mounting holes 311 of the pressure relief device 100 from the inside of the battery pack housing 102 to securely connect the pressure relief device 100 to the battery pack mounting holes 402. Because the mounting holes 311 of the pressure relief device 100 are disposed within the blind holes 605, the provision of the blind holes 605 on the housing 111 facilitates the positioning and connection of the mounting base 109 and the base 114, while also providing space for fasteners, thereby facilitating the secure connection of the pressure relief device 100 to the battery pack housing 102. When the pressure relief device 100 is fixedly connected to the battery pack shell 102, the multiple mounting seat through holes 524 on the bottom plate 219 of the mounting seat 109 are connected to the battery pack connecting hole 401, so that the internal space 103 of the battery pack 110 can be connected to the shell through hole 213 through the multiple mounting seat through holes 524.

[0044] When the valve core assembly 800 is located in the housing cavity 501, the elastic member 202 is clamped between the inner surface of the housing cover 112 and the top 221 of the valve core 201. Figure 9 and Figure 10 As shown, the upper guide hole wall 518 not only protrudes from the upper surface of the cover 112 but also extends downward from the lower surface of the cover 112 for a distance. The extension of the upper guide hole wall 518 from the lower surface of the cover 112 allows the top end of the elastic member 202 to fit over the outer side of the lower end of the upper guide hole wall 518. The valve core body 340 is provided with an elastic member receiving groove 901 between the valve core inner ring 344 and the bottom of the lower guide member 215. The elastic member receiving groove 901 is annular and surrounds the outer side of the bottom of the lower guide member 215, accommodating the lower end of the elastic member 202. The upper guide hole wall 518 and the elastic member receiving groove 901 respectively provide relatively fixed mounting positions for the upper and lower ends of the elastic member 202, thereby ensuring that the elastic member 202 is relatively fixedly clamped between the housing 111 and the valve core 201. The arrangement of the elastic member 202 in the valve core assembly 800 enables the valve core 201 to move up and down within the housing cavity 501. Figure 9 and Figure 10 The structure of the pressure relief device 100 is shown when the valve core 201 is located in the first position 511 and the second position 512. When the valve core 201 moves between the first position 511 and the second position 512, the upper guide hole 218 on the cover 112 and the lower guide groove 301 on the base 114 can respectively provide a movable path for the upper guide member 212 and the lower guide member 215 of the valve core 201.

[0045] like Figure 9As shown, the first position 511 of the valve core 201 is the initial position of the valve core 201. When the valve core 201 is in the initial position, the bottom 222 of the valve core 201 is connected to the upper surface of the middle platform 515 of the housing 111, and the valve core body 340 covers the housing through hole 213. The bottom of the valve core 201 is also provided with an annular valve core sealing groove 602. To achieve a sealed connection between the valve core 201 and the housing 111, the valve core sealing ring 204 is clamped between the valve core sealing groove 602 and the housing sealing groove 302. When the valve core 201 is in the first position 511, because the valve core sealing ring 204 is installed in an interference fit between the valve core sealing groove 602 and the housing sealing groove 302, the outer edge of the valve core body 340 is sealed to the middle platform 515 of the housing 111.

[0046] like Figure 9 As shown, the bottom of the multiple valve core through-holes 217 on the valve core 201 is connected to the housing through-hole 213, and the top of the valve core through-holes 217 is connected to the housing cavity 501 above the breathable film 203 through the breathable film 203. The housing cavity 501 above the breathable film 203 can be connected to the external environment through the multiple breathable holes 117 on the housing 111. Because the multiple mounting seat through-holes 524 on the pressure relief device 100 can simultaneously connect the housing through-hole 213 with the internal space 103 of the battery pack 101, when the pressure in the internal space 103 of the battery pack 101 is greater than the pressure of the external environment, the gas inside the battery pack 110 can pass through the battery pack communication hole 401, the mounting seat through-holes 524, the housing through-hole 213, the valve body through-hole 217, and then slowly discharge to the external environment through the breathable film 203, thereby achieving a balance between the internal and external pressures of the battery pack 101. When the pressure inside the battery pack 110 is less than a predetermined value, the bottom 222 of the valve core 201 remains connected to the upper surface of the intermediate platform 515 of the housing 111. At this point, the pressure relief function of the breathable film 203 in the pressure relief device 100 can meet the pressure relief requirements of the internal space 103 of the battery pack 110.

[0047] In this embodiment, when the valve core 201 is in the initial position, in order to achieve a sealed connection between the valve core 201 and the upper surface of the middle platform 515 of the shell 111, the elastic member 202 is in a compressed state, exerting a downward force on the top 221 of the valve core 201. For the convenience of description, this application refers to this downward force as the first elastic pressure. When the air pressure in the internal space 103 of the battery pack 110 is greater than a predetermined value, the internal gas of the battery pack 110 exerts an upward force on the bottom 222 of the valve core 201. The direction of this force is opposite to the direction of the first elastic pressure, and its magnitude is greater than that of the first elastic pressure, so that the valve core 201 can overcome the elastic force of the elastic member 202 and move upward to Figure 10The second position 512 is shown. When the valve core 201 moves from the first position 511 to the second position 512, the elastic member 202 is further compressed.

[0048] like Figure 10 As shown, when the valve core 201 is in the second position, the bottom 222 of the valve core 201 leaves the middle platform 515 of the shell 111, so that there is a distance between the bottom 222 of the valve core 201 and the upper surface of the middle platform 515, and a pressure relief channel 601 is formed between the bottom 222 of the valve core 201 and the shell 111. Since the pressure relief channel 601 can simultaneously connect the shell cavity 501 and the shell through hole 213, the gas from the internal space 103 of the battery pack 110 can escape directly from the pressure relief channel 601 to the external environment 120. When the pressure relief channel 601 is formed in the pressure relief device 100, the breathable film 203 can also play a role in ventilation. However, the ventilation efficiency of the breathable film 203 is much lower than the ventilation efficiency generated when the pressure relief member 502 is opened. When the pressure relief time is sufficient and the gas pressure in the internal space 103 of the battery pack 110 drops below a predetermined value, the restoring elastic force of the elastic member 202 causes the valve core 201 to move from the second position 512 to the first position 511. At this time, the valve core 201 returns to its original position. Figure 9 In the initial state shown, the bottom 222 of the valve core 201 is sealed to the shell 111 through the valve core sealing ring 204, the pressure relief channel 601 is closed, and the pressure relief device 100 only relies on the breathable film 203 to exhaust the internal space 103 of the battery pack 110.

[0049] like Figure 9 As shown, when the valve core 201 is in the initial position, the operating part 216 provided at the distal end 223 of the upper guide member 212 passes through the upper guide hole 218 in the cover 112, so that part of the operating part 216 is located outside the shell 111. The operating part 216 on the outside of the pressure relief device 100 is provided to facilitate the user to use an external airtightness detection tool (not shown in the figure) to perform an airtightness test on the battery pack 110 equipped with the pressure relief device 100. The steps for performing an airtightness test on the battery pack 110 by means of an external airtightness detection tool are as follows: First, the external airtightness detection tool is covered on the outside of the pressure relief device 100, thereby connecting the operating part 216 of the pressure relief device 100 through the airtightness detection tool. The airtightness detection tool then applies an upward force to the operating part 216 to move the valve core 201 upward from the initial position to Figure 10The second position 512 is shown. When the valve core 201 is in the second position 512, the pressure relief channel 601 in the pressure relief device 100 is opened, so that the internal space 103 of the battery pack 110 is directly connected to the external environment 120. Then, the airtightness detection tooling is controlled to inflate the internal space 103 of the battery pack through the pressure relief channel 601 in the pressure relief device 100 to perform subsequent airtightness detection. In order to ensure the inflation effect when inflating the internal space 103 of the battery pack 110 and the effect of the airtightness detection of the battery pack 110, there is a joint surface in the airtightness detection tooling that fits with the joint surface 107 on the boss 106 in the pressure relief device 100. In other words, the battery pack 110 of the present application can not only make the pressure relief channel 601 of the pressure relief device 100 in an open state when the pressure in the internal space 103 is greater than the predetermined pressure. When a user applies a certain upward force to the operating portion 216 of the pressure relief device 100, the pressure relief channel 601 of the pressure relief device 100 can also be opened. The configuration of the operating portion 216 in the pressure relief device 100 and the configuration of the joint surface 107 surrounding the outer periphery of the housing 111 of the pressure relief device 100 can effectively assist external airtightness testing tooling in performing airtightness testing on the battery pack 110 installed with the pressure relief device 100.

[0050] When the pressure relief device 100 needs to be installed on the battery pack shell 102 from the inside of the battery pack 110, the pressure relief device 100 must be installed on the battery pack shell 102 before the battery pack shell 102 is formed as a whole. When the battery pack shell 102 is formed as a whole, the pressure relief device 100 has been installed on the battery pack connecting hole 401 on the battery pack shell 102. In the prior art, an external airtightness detection device is usually used to inflate the interior of the battery pack shell 102 to detect the airtightness of the battery pack 110. However, for the existing pressure relief device structure, if the pressure relief device 100 is already installed on the battery pack connecting hole 401 during the airtightness test, then the airtightness detection device cannot achieve the step of inflating the interior of the battery pack shell 102. The present application improves the structure of the existing pressure relief device so that an openable and closable pressure relief channel 601 can be formed inside the pressure relief device 100. The user can operate from the outside of the pressure relief device 100 to inflate the battery pack 110 through the pressure relief device 100, thereby realizing airtightness testing of the battery pack 110 equipped with the pressure relief device 100.

[0051] The pressure relief device 100 of this application is equipped with an elastic member 202. The elastic properties of the elastic member 202 enable the valve core 504 to move up and down within the pressure relief device 100. As the valve core 504 moves up and down, an openable and closable pressure relief channel 601 is constructed within the pressure relief device 100 to relieve pressure in the internal space 103 of the battery pack 110. Because each opening and pressure release of the pressure relief member 504 does not damage the inherent structure of the pressure relief device 100, the pressure relief device 100 of this application is reusable, eliminating the need to replace the pressure relief device 100 after each pressure release, significantly reducing the cost of the pressure relief device 100. Furthermore, the preset pressure value for the centralized pressure relief of the pressure relief device 100 of this application can be adjusted based on the materials used for the elastic member 202 and the valve core 201. When the elastic member 202 has greater elasticity and lower hardness, the pressure relief device 100 has a lower preset pressure value. When the elastic member 202 has lower elasticity and higher hardness, the pressure relief device 100 has a higher set pressure value.

[0052] The pressure relief device 100 of the present application is used in a battery pack 110. In other embodiments, the pressure relief device 100 can also be installed in other components that require pressure relief. In this embodiment, the battery pack 110 using the pressure relief device 100 is installed in an electric vehicle, such as an electric vehicle, a hybrid vehicle, etc. In other embodiments, the pressure relief device 100 can also be used in battery packs 110 in other technical fields.

[0053] Although the present application will be described with reference to specific embodiments shown in the accompanying drawings, it should be understood that the pressure relief device of the present application may be modified in many ways without departing from the spirit, scope, and context of the present application. Those skilled in the art will also recognize that there are different ways to modify the structure of the embodiments disclosed in the present application, all of which fall within the spirit and scope of the present application and the claims.

Claims

1. A pressure relief device, characterized in that: The pressure relief device (100) comprises: A housing (111), wherein the housing (111) has a housing cavity (501) therein, and the housing (111) is provided with a housing through hole (213), wherein the housing through hole (213) is in communication with an internal space (103) of the component (101) to be depressurized; A valve core (201), the valve core (201) being disposed in the housing cavity (501), the valve core (201) comprising a top portion (221), a bottom portion (222), and a valve core through hole (217) extending from the top portion (221) to the bottom portion (222), a breathable film (203) covering the valve core through hole (217) being disposed on the top portion (221) of the valve core (201), the valve core (201) having a first position (511) and a second position (512), and being configured to be movable relative to the housing (111) between the first position (511) and the second position (512); an elastic member (202), the elastic member (202) being clamped between the housing (111) and the top (221) of the valve core (201); and A metal mounting seat (109), the metal mounting seat (109) being arranged at the bottom of the housing (111), the metal mounting seat (109) being configured to be connected to the housing (111), and the metal mounting seat (109) being configured to be connected to the component to be relieved (101) via a fastener, so that the pressure relief device is configured to be mounted to the component to be relieved (101) from the inner side of the component to be relieved (101) via the metal mounting seat (109), wherein, in the first position (511), the valve core (201) is supported by the housing (111), the bottom (222) of the valve core (201) covers the housing through hole (213), and the housing through hole (213) can communicate with the housing cavity (501) through the valve core through hole (217); in the second position (512), the valve core (201) leaves the housing (111) to form a pressure relief channel (601) between the bottom (222) of the valve core (201) and the housing (111), and the housing through hole (213) can communicate with the housing cavity (501) through the pressure relief channel (601); and When the valve core (201) moves from the first position (511) to the second position (512), the elastic member (202) is compressed, and the restoring elastic force of the elastic member (202) enables the valve core (201) to move from the second position (512) to the first position (511). The valve core (201) further includes an upper guide member (212) disposed on a top portion (221) of the valve core (201); The housing (111) is provided with an upper guide hole (218), and the upper guide hole (218) is capable of receiving the upper guide member (212) to guide the movement of the valve core (201). The distal end (223) of the upper guide member (212) extends through the upper guide hole (218) to the outside of the housing (111), wherein an operating portion (216) is provided on the distal end (223), and the operating portion (216) is configured to be able to pull the valve core (201) from the first position (511) to the second position (512) through the operating portion (216).

2. The pressure relief device according to claim 1, characterized in that: The elastic member (202) is a spring, and the spring is sleeved on the upper guide member (212).

3. The pressure relief device according to claim 1, characterized in that: The valve core (201) further includes a plurality of lower guide members (215) arranged on the bottom (222) of the valve core (201); A plurality of lower guide grooves (301) are provided on the hole wall of the shell through hole (213) of the shell (111), and the plurality of lower guide grooves (301) can correspondingly receive the plurality of lower guide members (215) to guide the movement of the valve core (201).

4. The pressure relief device according to claim 3, characterized in that: The housing (111) further comprises a boss (106) arranged around the outer periphery of the housing (111), wherein the boss (106) has a joint surface (107) around the outer periphery of the housing (111), and the joint surface (107) faces away from the component (101) to be relieved of pressure.

5. The pressure relief device according to claim 1, characterized in that: The pressure relief device (100) further comprises a valve core sealing ring (204), wherein the valve core sealing ring (204) is arranged between the bottom (222) of the valve core (201) and the housing (111), and when the valve core (201) is in the first position (511), the valve core sealing ring (204) can sealably connect the bottom (222) of the valve core (201) and the housing (111).

6. The pressure relief device according to claim 5, characterized in that: The valve core sealing ring (204) is arranged in a housing sealing groove (302) surrounding the housing through hole (213); The bottom (222) of the valve core (201) is provided with a valve core sealing groove (602), and the valve core sealing groove (602) is configured such that when the valve core (201) is in the first position (511), the valve core sealing ring (204) is clamped between the housing sealing groove (302) and the valve core sealing groove (602).

7. The pressure relief device according to claim 1, characterized in that: When the valve core (201) is in the first position (511), the elastic member (202) applies a first elastic pressure to the valve core (201); when the valve core (201) is subjected to a force that is opposite to the direction of the first elastic pressure and is greater than the first elastic pressure, the valve core (201) can leave the housing (111) and move to the second position (512).

8. The pressure relief device according to claim 1, characterized in that: The housing (111) is further provided with an air vent (113), and the air vent (113) is configured to connect the housing cavity (501) with the external environment (120), so that when the valve core (201) is in the second position (512), the pressure relief channel (601) can connect the internal space (103) of the component to be relieved (101) with the external environment (120).

9. The pressure relief device according to claim 1, wherein: The metal mounting seat (109) is provided with a mounting hole (311), and the component to be relieved (101) is provided with a corresponding mounting hole (402), so that when the pressure relief device is mounted on the component to be relieved (101), the fastener is sequentially passed through the mounting hole (402) of the component to be relieved (101) and the mounting hole (311) of the metal mounting seat (109) from the inner side of the component to be relieved (101) so that the pressure relief device and the component to be relieved (101) are fastened and connected, and The metal mounting seat (109) is provided with a mounting seat through hole (524). When the metal mounting seat (109) is connected to the shell (111), the mounting seat through hole (524) is communicated with the internal space (103) of the component to be depressurized (101) and is also communicated with the shell through hole (213) of the shell (111).

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