Box body explosion-proof valve, battery pack and electric device

Abstract

This invention provides an explosion-proof valve for a battery enclosure, a battery pack, and an electrical device, relating to the field of battery technology. The explosion-proof valve includes: a valve body comprising a first end face and a second end face disposed opposite to each other; a pressure relief hole on the valve body; a first annular groove on the first end face; a first sealing element; a partition frame connected to the wall of the pressure relief hole; a piston rod movably disposed on the partition frame; and a cover plate fixedly connected to the piston rod, wherein moving the piston rod causes the cover plate to open or cover the pressure relief hole. The ratio of the width of the first annular groove to the radius of the pressure relief hole is a first ratio M; the ratio of the area of ​​the first projected region to the area of ​​the second projected region is a second ratio J; and the product of the first ratio M and the second ratio J, M×J, is greater than or equal to 5.72×10⁻⁶. ‑3 And less than or equal to 75 × 10 ‑3 This is to address the sealing failure issue of explosion-proof valves in related technologies.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically, to an explosion-proof valve for a housing, a battery pack, and an electrical device. Background Technology

[0002] An opening needs to be made in the battery enclosure frame where the explosion-proof valve is installed to connect the valve to the inside of the frame. A piston-type explosion-proof valve is a commonly used type. When the pressure inside the enclosure rises sharply (e.g., during thermal runaway), the gas pressure forces open the explosion-proof valve, creating a venting channel for rapid pressure relief. After the pressure drops, the piston rod automatically resets, and the explosion-proof valve closes.

[0003] However, during use, there has been a risk that the explosion-proof valve of the enclosure may fail to seal under vibration conditions or when the enclosure is depressurized, resulting in deformation or even rupture, which affects the safety of the battery pack. Summary of the Invention

[0004] The main objective of this invention is to provide an explosion-proof valve for a housing, a battery pack, and an electrical device to solve the problem of sealing failure of explosion-proof valves for housings in related technologies.

[0005] To achieve the above objectives, according to one aspect of the present invention, a housing explosion-proof valve is provided, comprising: a valve body including a first end face and a second end face disposed opposite to each other, a pressure relief hole provided on the valve body, the pressure relief hole penetrating the first end face and the second end face along its axial direction, a first annular groove provided on the first end face; a first sealing member disposed within the first annular groove; and a partition frame connected to the wall of the pressure relief hole and dividing the pressure relief hole into at least two pressure relief channels, the partition frame forming a first projection on a plane parallel to the first end face, and the area enclosed by the wall of the pressure relief hole forming a second projection on a plane parallel to the first end face. A piston rod is movably mounted on a partition frame, which has a through hole for the piston rod to pass through. The piston rod is slidably connected to the partition frame. A cover plate is fixedly connected to the piston rod and is located on the side of the second end face away from the first end face. When the piston rod moves, it causes the cover plate to open or cover the pressure relief hole. A spring has its two ends abutting against the partition frame and the piston rod, respectively. The ratio of the width of the first annular groove to the radius of the pressure relief hole is a first ratio M, the ratio of the area of ​​the first projected area to the area of ​​the second projected area is a second ratio J, and the product of the first ratio M and the second ratio J, M×J, is greater than or equal to 5.72×10⁻⁶. -3 And less than or equal to 75 × 10 -3 .

[0006] According to another aspect of the present invention, a battery pack is provided, including a base plate, a frame surrounding the edge of the base plate, a box explosion-proof valve disposed on the frame, and a battery disposed within the frame, wherein the box explosion-proof valve is the aforementioned box explosion-proof valve.

[0007] According to another aspect of the present invention, an electrical device is provided, including a battery pack, wherein the battery pack is the battery pack described above.

[0008] Applying the technical solution of this invention, the explosion-proof valve for the enclosure includes: a valve body that can be mounted on a frame, and a first sealing element that seals the gap between the valve body and the frame to prevent foreign objects from entering the frame. When the explosion-proof valve does not reach the preset pressure, the cover plate covers the pressure relief hole to prevent leakage of the battery pack's medium or contamination from the outside, thus ensuring the normal operation of the battery pack; when the explosion-proof valve reaches the preset pressure, the cover plate is pushed to move away from the pressure relief hole, opening the pressure relief hole to release pressure. When the product of the first ratio M and the second ratio J, M×J, is less than 5.72×10... -3 When the ratio of the width of the first annular groove to the radius of the pressure relief hole is too small, or the ratio of the area of ​​the first projected portion to the area of ​​the second projected portion is too small, the deformation space of the first seal is too small. The first seal cannot fit tightly against the surfaces of the valve body and the frame, resulting in leakage points and poor sealing performance of the first seal. This leads to insufficient airtightness and failure to seal the gap between the valve body and the frame. When the product of the first ratio M and the second ratio J is greater than 75 × 10⁻⁶, the sealing performance of the first seal is poor, resulting in insufficient airtightness and failure to seal the gap between the valve body and the frame. -3 When the ratio of the width of the first annular groove to the radius of the pressure relief hole is too large, or the ratio of the area of ​​the first projected portion to the area of ​​the second projected portion is too large, the first annular groove or partition occupies most of the space of the pressure relief hole. This reduces the total effective flow cross-sectional area of ​​at least two pressure relief channels, resulting in a smaller exhaust space for the explosion-proof valve in the enclosure. This creates resistance during pressure relief, leading to a poor pressure relief rate and delayed pressure relief, which can easily cause a chain reaction of thermal runaway within the enclosure. Therefore, the product of the first ratio M and the second ratio J should be controlled within 5.72 × 10⁻⁶. -3 Up to 75×10 -3 Within a certain range, the first seal deforms within a reasonable deformation space, allowing it to fit tightly against the surfaces of the valve body and the frame, preventing leaks and ensuring good sealing performance and sufficient airtightness. This prevents sealing failure of the gap between the valve body and the frame. Furthermore, the exhaust space of the explosion-proof valve is controlled to a reasonable size, preventing the first annular groove or partition from occupying most of the pressure relief hole space, reducing resistance during pressure relief, ensuring a reasonable pressure relief rate, and enabling timely pressure relief. This prevents the accumulation of high-temperature, high-pressure gas inside the enclosure and avoids the risk of a chain reaction of thermal runaway within the frame. Therefore, the technical solution of this application effectively solves the problem of sealing failure in explosion-proof valves in related technologies. Attached Figure Description

[0009] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0010] Figure 1 A three-dimensional structural schematic diagram is shown of an embodiment of the explosion-proof valve for housing according to the present invention, in which the cover portion covers the pressure relief hole;

[0011] Figure 2 A three-dimensional structural schematic diagram of the cover portion of an embodiment of the explosion-proof valve for housings according to the present invention is shown when the pressure relief hole is opened;

[0012] Figure 3 A cross-sectional schematic diagram is shown of an embodiment of the explosion-proof valve for housings according to the present invention, in which the cover portion covers the pressure relief hole;

[0013] Figure 4 It shows Figure 3 An enlarged schematic diagram of point A of the explosion-proof valve in the enclosure;

[0014] Figure 5 A cross-sectional schematic diagram is shown of the cover portion of an embodiment of the explosion-proof valve for housings according to the present invention when the pressure relief hole is opened;

[0015] Figure 6 A three-dimensional structural schematic diagram from another perspective is shown of an embodiment of the explosion-proof valve for housings according to the present invention, in which the cover portion covers the pressure relief hole;

[0016] Figure 7 It shows Figure 6 An enlarged schematic diagram of point B on the explosion-proof valve of the enclosure;

[0017] Figure 8 A perspective structural schematic diagram of an embodiment of the explosion-proof valve for housing according to the present invention is shown, with the cover portion not shown.

[0018] Figure 9 A three-dimensional structural schematic diagram of an embodiment of the battery pack according to the present invention is shown;

[0019] Figure 10 It shows Figure 9 A partial structural diagram of the battery pack casing after being cut open at the explosion-proof valve.

[0020] Figure 11 It shows Figure 10 An enlarged schematic diagram of point D of the battery pack;

[0021] Figure 12 It shows Figure 10 The front view of the battery pack at point D;

[0022] Figure 13 It shows Figure 10A partial cross-sectional view of the battery compartment of the battery pack.

[0023] The above figures include the following reference numerals:

[0024] 1. Explosion-proof valve of enclosure; 10. Valve body; 101. First end face; 102. Second end face; 103. Outer peripheral surface; 11. Pressure relief hole; 111. Pressure relief channel; 14. First annular groove; 15. Second annular groove; 16. Fixing part;

[0025] 20. Divider frame; 201. Through hole; 21. Common part; 25. Divider rib;

[0026] 31. Piston rod; 32. Cover plate; 33. Spring;

[0027] 40. Install the cylinder;

[0028] 50. First seal; 51. Annular portion; 52. Protrusion; 53. Second seal;

[0029] 61. Enclosure frame; 611. Outer wall; 612. Inner wall; 613. Mounting hole; 614. Cavity; 62. Base plate; 63. Draft shield;

[0030] 70. Battery; 71. Battery explosion-proof valve; 72. Exhaust channel. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0034] Research has found that to prevent foreign objects such as moisture and dust from entering through the connection between the explosion-proof valve and the enclosure, thus affecting battery life, a seal needs to be installed between the explosion-proof valve and the enclosure to isolate foreign objects. Due to the overall size limitations of the battery pack—namely, the overall size of the enclosure and the size of the mounting holes for the explosion-proof valve—the overall size of the explosion-proof valve is also limited. The explosion-proof valve has a groove corresponding to the seal; this groove reduces the size of the pressure relief opening on the valve, resulting in insufficient pressure relief space and slow pressure relief. This could lead to severe thermal runaway in the battery pack, affecting its safety.

[0035] To address the aforementioned problems, according to one aspect of this application, a housing explosion-proof valve is provided, such as... Figures 1 to 12As shown, one embodiment of the explosion-proof valve includes: a valve body 10, a first seal 50, a separator 20, a spring 33, a piston rod 31, and a cover plate 32. The valve body 10 includes a first end face 101 and a second end face 102 disposed opposite to each other. A pressure relief hole 11 is provided on the valve body 10, penetrating the first end face 101 and the second end face 102 along its axis C. A first annular groove 14 is provided on the first end face 101. The first seal 50 is disposed within the first annular groove 14. The separator 20 is connected to the wall of the pressure relief hole 11 and divides the pressure relief hole 11 into at least two pressure relief channels 111. The separator 20 forms a first projection on a plane parallel to the first end face 101, and the area enclosed by the wall of the pressure relief hole 11 forms a second projection on a plane parallel to the first end face 101. A piston rod 31 is movably mounted on a partition frame 20. The partition frame 20 has a through hole 201 through which the piston rod 31 passes. The piston rod 31 is slidably connected to the partition frame 20. A cover plate 32 is fixedly connected to the piston rod 31. The cover plate 32 is located on the side of the second end face 102 opposite to the first end face 101. When the piston rod 31 moves, it causes the cover plate 32 to open or cover the pressure relief hole 11. The two ends of the spring 33 abut against the partition frame 20 and the piston rod 31, respectively. The ratio of the width of the first annular groove 14 to the radius of the pressure relief hole 11 is a first ratio M; the ratio of the area of ​​the first projected area to the area of ​​the second projected area is a second ratio J; and the product of the first ratio M and the second ratio J, M×J, is greater than or equal to 5.72×10⁻⁶. -3 And less than or equal to 75 × 10 -3 .

[0036] It should be noted that the "×" used in this application represents the multiplication sign.

[0037] Using the technical solution of this application, the valve body 10 can be installed on the frame, and the first sealing member 50 can seal the gap between the valve body 10 and the frame to prevent foreign objects from entering the frame. When the explosion-proof valve of the enclosure does not reach the preset pressure, the cover plate 32 covers the pressure relief hole 11 to prevent the battery pack from leaking or being contaminated by the outside, so as to ensure the normal operation of the battery pack; when the explosion-proof valve of the enclosure reaches the preset pressure, it pushes the cover plate 32 to move away from the pressure relief hole 11, and the cover plate 32 opens the pressure relief hole 11 to achieve pressure relief.

[0038] When the product of the first ratio M and the second ratio J is less than 5.72 × 10 -3When the ratio of the width of the first annular groove 14 to the radius of the pressure relief hole 11 is too small, or the ratio of the area of ​​the first projected portion to the area of ​​the second projected portion is too small, the deformation space of the first seal 50 is too small. The first seal 50 cannot fit tightly against the surface of the valve body 10 and the frame, resulting in leakage points and poor sealing performance of the first seal 50, leading to insufficient airtightness and failure to seal the gap between the valve body 10 and the frame. When the product of the first ratio M and the second ratio J is greater than 75 × 10... -3 When the ratio of the width of the first annular groove 14 to the radius of the pressure relief hole 11 is too large, or the ratio of the area of ​​the first projected portion to the area of ​​the second projected portion is too large, the first annular groove 14 or the partition 20 occupies most of the space of the pressure relief hole 11. This reduces the total effective flow cross-sectional area of ​​at least two pressure relief channels 111, resulting in a smaller exhaust space for the explosion-proof valve in the enclosure. This creates resistance during pressure relief, leading to a poor pressure relief rate and delayed pressure relief, which can easily cause a chain reaction of thermal runaway within the enclosure. Therefore, the product of the first ratio M and the second ratio J should be controlled within 5.72 × 10⁻⁶. -3 Up to 75×10 -3 Within a reasonable deformation range, the first sealing element 50 deforms within a reasonable deformation space, allowing it to fit tightly against the surfaces of the valve body 10 and the frame, preventing leaks and ensuring good sealing performance and sufficient airtightness. This prevents sealing failure of the gap between the valve body 10 and the frame. Furthermore, the exhaust space of the explosion-proof valve is controlled to a reasonable size, preventing the first annular groove 14 or the partition frame 20 from occupying most of the space of the pressure relief hole 11, reducing resistance during pressure relief, ensuring a reasonable pressure relief rate, and enabling the explosion-proof valve to release pressure in a timely manner. This prevents the accumulation of high-temperature and high-pressure gas inside the enclosure and avoids the risk of a chain reaction of thermal runaway within the frame. Therefore, the technical solution of this application effectively solves the problem of sealing failure of explosion-proof valves in related technologies. Specifically, the two ends of the spring 33 abut against the partition frame 20 and the piston rod 31 respectively. When the cover plate 32 overcomes the spring force of the spring 33 under the action of external force and drives the piston rod 31 to extend out of the pressure relief hole 11, the pressure relief hole 11 is opened. When the cover plate 32 is not subjected to external force and the piston rod 31 is subjected to the spring force of the spring 33, the spring 33 drives the piston rod 31 to retract into the pressure relief hole 11 and causes the piston rod 31 to drive the cover plate 32 to cooperate with the stop wall (see below) to close the pressure relief hole 11.

[0039] The product of the first ratio M and the second ratio J is preferably 5.72 × 10⁻⁶. -3 6×10 -3 9×10 -3 12×10 -3 15×10 -3 18×10 -3 21×10-3 24×10 -3 27×10 -3 30×10 -3 33×10 -3 36×10 -3 39×10 -3 42×10 -3 45×10 -3 48×10 -3 51×10 -3 54×10 -3 57×10 -3 60×10 -3 63×10 -3 66×10 -3 69×10 -3 72×10 -3 Or 75×10 -3 It can be any value in the range or a value between any two values.

[0040] The study found that if the ratio of the width of the first annular groove 14 to the radius of the pressure relief hole 11 is too small, the battery pack's airtightness will be insufficient; if the ratio is too large, the exhaust space will be insufficient, resulting in a slow pressure relief speed. If the ratio of the area of ​​the first projection to the area of ​​the second projection is too small, the partition frame is prone to deformation during pressure relief, leading to accidental leakage of the explosion-proof valve in the enclosure and a decrease in sealing performance, resulting in seal failure and easy entry of moisture into the pressure relief hole 11; if the ratio is too large, the pressure relief opening of the cover plate 32 will be small, resulting in a poor pressure relief rate.

[0041] Specifically, the aforementioned first sealing element 50 isolates foreign objects, preventing moisture, dust, and other foreign objects from entering the enclosure from the connection between the explosion-proof valve and the enclosure, thus avoiding affecting the battery's lifespan.

[0042] The explosion-proof valve of the aforementioned enclosure can be made of metal or flame-retardant polymer materials such as polyvinyl chloride, polyvinylidene chloride, and fluoroplastics, specifically including iron, aluminum, copper, titanium, aluminum alloy, stainless steel, and titanium alloy.

[0043] The aforementioned explosion-proof valve for the battery pack is a component that actuates to release internal pressure or temperature when the internal pressure or temperature reaches a predetermined threshold. It is used to prevent the risk of explosion caused by abnormal conditions such as battery overheating or overcharging, ensuring the safe operation of the battery. When the battery is operating normally, the explosion-proof valve seals the battery casing to ensure normal battery operation; in the event of thermal runaway, the explosion-proof valve needs to activate its explosion-proof function promptly to release internal gas and heat, thereby reducing the risk of explosion. The working principle of the explosion-proof valve is to establish a regulating venting channel inside the battery pack. When the internal pressure of the battery pack increases, the valve opens, allowing gas to be released from the battery pack, thereby reducing the pressure. The explosion-proof valve may include a housing, a valve cover, and a hinge structure.

[0044] like Figures 1 to 5 As shown, in the radial direction of the pressure relief hole 11, the inner ring surface of the first annular groove 14 is spaced apart from the hole wall surface of the pressure relief hole 11. This ensures that the hole wall of the pressure relief hole 11 is supported in the radial direction by a portion of the solid structure of the valve body 10, preventing the placement of the first annular groove 14 from weakening the structural strength of the hole wall of the pressure relief hole 11, thereby improving the deformation resistance of the pressure relief hole 11 and preventing the sealing failure of the first seal 50 caused by deformation of the hole wall of the pressure relief hole 11.

[0045] The materials of the first and second sealing elements in this application include, but are not limited to, rubber-based sealing materials and engineering plastic sealing materials. Rubber-based sealing materials include: nitrile rubber, hydrogenated nitrile rubber, fluororubber, silicone rubber, acrylate rubber, and EPDM rubber. Engineering plastic sealing materials include: polytetrafluoroethylene, polyetheretherketone (PEEK), and polyurethane.

[0046] like Figures 1 to 5 As shown, the inner ring surface of the first annular groove 14 is spaced apart from the wall surface of the pressure relief hole 11 by a first distance H1mm, where the first distance H1mm is greater than or equal to 0.6mm and less than or equal to 5mm. This first distance H1mm range ensures that the wall of the pressure relief hole 11 is supported radially by a portion of the solid structure of the valve body 10, preventing the placement of the first annular groove 14 from weakening the structural strength of the wall thickness of the pressure relief hole 11, thereby improving the deformation resistance of the pressure relief hole 11. Simultaneously, the placement of the pressure relief hole 11 also avoids weakening the structural strength of the groove wall thickness of the first annular groove 14, further improving the deformation resistance of the first annular groove 14. This facilitates the stable installation of the first sealing element 50 within the first annular groove 14, ensuring that the sealing function of the first sealing element 50 is not affected by the reduced strength of the wall of the pressure relief hole 11, thus preventing sealing failure caused by deformation of the wall of the pressure relief hole 11.

[0047] The first distance H1mm mentioned above is preferably any value among 0.6mm, 1.1mm, 1.6mm, 2.1mm, 2.6mm, 3.1mm, 3.6mm, 4.1mm, 4.6mm or 5mm, or a value between any two values.

[0048] Furthermore, in the radial direction of the pressure relief hole 11, the minimum distance between the outer ring surface of the first annular groove 14 and the outer peripheral surface 103 of the valve body portion 10 is greater than or equal to 0.6 mm and less than or equal to 5 mm.

[0049] The minimum distance mentioned above is preferably any value among 0.6mm, 1.1mm, 1.6mm, 2.1mm, 2.6mm, 3.1mm, 3.6mm, 4.1mm, 4.6mm or 5mm, or a value between any two values.

[0050] The aforementioned minimum distance is limited to a range of 0.6mm to 5mm, ensuring that the valve body 10 retains sufficient wall thickness in the outer region of the first annular groove 14. This guarantees sufficient structural strength of the valve body 10 and effectively avoids the risk of deformation or breakage due to excessively thin walls. This ensures the structural integrity of the first annular groove 14, facilitating the sealing performance of the first sealing element 50 and significantly improving the sealing reliability of the explosion-proof valve under long-term use. Simultaneously, the product of the aforementioned minimum distance range and the first ratio M and the second ratio J is controlled to be within 9.1 × 10⁻⁶. -3 Up to 53.78×10 -3 The coordinated operation within the specified range ensures both the flow rate of the pressure relief channel 111 and the overall structural strength of the valve body 10, achieving a better balance between sealing performance and structural strength.

[0051] The product of the first ratio M and the second ratio J is preferably 9.1 × 10⁻⁶. -3 10×10 -3 20×10 -3 30×10 -3 40×10 -3 50×10 -3 Or 53.78×10 -3 It can be any value in the range or a value between any two values.

[0052] like Figures 2 to 6As shown, the first seal 50 includes an annular portion 51 and a protrusion 52 disposed on the annular portion 51. In the radial direction of the pressure relief hole 11, the width of the annular portion 51 is smaller than the groove width of the first annular groove 14. In the radial direction of the pressure relief hole 11, the protrusion 52 protrudes from the outer surface of the annular portion 51 toward the outer ring surface of the first annular groove 14. When the first seal 50 is compressed by the valve body portion 10 and the surrounding frame, a deformable space is reserved between the annular portion 51 and the groove wall of the first annular groove 14. The first seal 50 deforms within the first annular groove 14, allowing the annular portion 51 to fully fill the deformable space after deformation. Furthermore, the protrusion 52, after being compressed, makes full contact with the groove wall surface of the first annular groove 14, increasing the friction of the first seal 50. This ensures that the first seal 50 is reliably and stably positioned within the first annular groove 14, improving the reliability of the seal. In the radial direction of the pressure relief hole 11, the protrusion 52 protrudes from the inner side of the annular portion 51 toward the inner ring surface of the first annular groove 14. Furthermore, when the first seal 50 deforms within the first annular groove 14, the protrusion 52 is the first to contact the groove wall of the first annular groove 14 during the deformation process, forming a local elastic buffer area. The protrusion 52 effectively absorbs the volume change caused by the expansion of the annular portion 51 under pressure, avoiding the risk of leakage due to the annular portion 51 being squeezed and separating from the groove wall of the first annular groove 14, thus improving the sealing performance and long-term sealing reliability of the first seal 50.

[0053] like Figures 2 to 6 As shown, the first seal 50 includes an annular portion 51 and a protrusion 52 disposed on the annular portion 51. In the radial direction of the pressure relief hole 11, the width of the annular portion 51 is smaller than the groove width of the first annular groove 14. This allows the first seal 50 to partially release its volume expansion into the radial space of the first annular groove 14 when it undergoes elastic deformation under the pressure of the valve body portion 10 and the surrounding frame. Specifically, in the radial direction of the pressure relief hole 11, the protrusion 52 protrudes from the outer surface of the annular portion 51 by a distance greater than or equal to 0.3 mm and less than or equal to 1 mm towards the outer surface of the first annular groove 14. This distance range provides a controllable deformation accommodating space within the first annular groove 14 towards the outer surface of the first annular groove 14 when the pressure inside the pressure relief hole 11 increases. This effectively prevents the first seal 50 from overflowing into the first annular groove 14 due to excessive pressure, thus maintaining its sealing performance while preventing seal failure caused by stress concentration.

[0054] In the radial direction of the pressure relief hole 11, the protrusion 52 protrudes from the inner surface of the annular portion 51 by a distance greater than or equal to 0.3 mm and less than or equal to 1 mm toward the inner ring surface of the first annular groove 14. This distance range provides a controllable deformation accommodating space within the first annular groove 14 toward the inner ring surface of the first sealing member 50 when the pressure inside the pressure relief hole 11 increases. This effectively prevents the first sealing member 50 from overflowing into the first annular groove 14 due to excessive pressure, thus maintaining its sealing performance while preventing seal failure caused by stress concentration. Furthermore, when the aforementioned protrusion 52 protrudes from the outer surface of the annular portion 51 at a distance greater than or equal to 0.3 mm and less than or equal to 1 mm toward the outer surface of the first annular groove 14, and when the protrusion 52 protrudes from the inner surface of the annular portion 51 at a distance greater than or equal to 0.3 mm and less than or equal to 1 mm toward the inner surface of the first annular groove 14, it can work together with the first ratio M and the second ratio J to ensure both the flow rate of the pressure relief channel and the long-term stability of the sealing performance formed by the first sealing element 50 under different pressure environments, thereby improving the reliability of the explosion-proof valve of the housing under pressure relief impact conditions.

[0055] The distance by which the protrusion 52 protrudes from the outer surface of the annular portion 51 toward the outer ring surface of the first annular groove 14 is preferably any one of 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1.0mm or a value between any two of these values.

[0056] The distance by which the protrusion 52 protrudes from the inner surface of the annular portion 51 toward the inner ring surface of the first annular groove 14 is preferably any one of 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1.0mm or a value between any two of these values.

[0057] like Figures 2 to 7 As shown, there are multiple protrusions 52, which are spaced apart circumferentially along the annular portion 51. The distance between any two adjacent protrusions 52 in the circumferential direction of the annular portion 51 is greater than or equal to 8 mm and less than or equal to 20 mm. Within this distance range, during the radial deformation of the first seal 50 under compression, the deformation volume of the first seal 50 can be locally accommodated by the spacing between adjacent protrusions 52, rather than concentrated at the position of a single protrusion 52. This effectively avoids tearing or sealing failure of the first seal 50 due to localized stress concentration. Simultaneously, the annular portion 51, under pressure, has the support and buffering effect of multiple protrusions 52, maintaining a stable fit between the first seal 50 and the annular groove wall of the first annular groove 14, while also providing a controllable deformation space, significantly improving the reliability of the seal.

[0058] The distance between any two adjacent protrusions 52 is preferably any value among 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm or 20mm, or a value between any two values.

[0059] like Figures 2 to 7 As shown, a second annular groove 15 is provided on the second end face 102. The explosion-proof valve of the enclosure also includes a second sealing element 53, which is disposed in the second annular groove 15. When the cover plate portion 32 abuts against the second sealing element 53, the cover plate portion 32 covers the pressure relief hole 11. When the cover plate portion 32 is in the covered position, the cover plate portion 32 directly abuts against the second sealing element 53, which can block the pressure relief hole 11, thereby effectively preventing the gas inside the enclosure from leaking through the gap between the cover plate portion 32 and the inner wall of the valve body portion 10, or preventing foreign objects from entering the pressure relief hole 11.

[0060] like Figures 2 to 7 As shown, the width of the second annular groove 15 is less than or equal to the width of the first annular groove 14. When the cover plate 32 covers the pressure relief hole 11, the cover plate 32 abuts against the second seal 53 to achieve a seal. The depth of the second annular groove 15 is less than or equal to the depth of the first annular groove 14. The compressive force borne by the second seal 53 under the compression state is less than that of the first seal 50, effectively preventing the risk of medium leakage or foreign matter ingress caused by the failure of the second seal 53 due to excessive compression under pressure relief conditions. Furthermore, since the risk of sealing failure of the first seal 50 is higher than that of the second seal 53, the aforementioned range of groove width and depth allows for a larger volume of the first seal 50 to be installed in the first annular groove 14, effectively improving the sealing performance and sealing reliability of the first seal 50.

[0061] like Figures 2 to 7 As shown, the first annular groove 14 and the second annular groove 15 form a third projection and a fourth projection respectively on a plane parallel to the first end face 101, and the third projection and the fourth projection do not overlap at least partially. The above-mentioned structural arrangement avoids the weakening of the structural strength of the valve body 10 caused by the removal of material from both the first annular groove 14 and the second annular groove 15 in the same direction of the valve body 10. It can effectively disperse the risk of stress concentration, improve the overall structural strength of the valve body 10 in the corresponding areas of the first annular groove 14 and the second annular groove 15, and ensure that the valve body 10 can still maintain good sealing performance for the first seal 50 and the second seal 53 during long-term use.

[0062] It should be noted that the fact that the third projection and the fourth projection do not overlap at least partially includes the fact that the third projection and the fourth projection do not overlap at all, as well as the intermediate state between the fact that the third projection and the fourth projection do not overlap at all and the fact that the third projection and the fourth projection do overlap at all.

[0063] like Figures 2 to 5 As shown, in the radial direction of the pressure relief hole 11, the inner wall of the first annular groove 14 has a first radial dimension with the inner wall of the pressure relief hole 11, and the inner wall of the second annular groove 15 has a second radial dimension with the inner wall of the pressure relief hole 11. The first radial dimension is larger than the second radial dimension. Since the first annular groove 14 is easily affected by water vapor and air, the first seal inside the first annular groove 14 is prone to oxidation. Therefore, the first annular groove 14 is set further away from the pressure relief hole 11 than the second annular groove 15, and the volume of the first seal is increased to improve the internal sealing environment and increase the sealing strength. At the same time, the size of the second seal is reduced to avoid oxidation of the second seal.

[0064] like Figures 2 to 7 As shown, the separator 20 includes a common portion 21 disposed within the pressure relief hole 11 and multiple separator ribs 25. The first end of each separator rib 25 is fixedly connected to the common portion 21, and the second end of each separator rib 25 is fixedly connected to the inner wall of the pressure relief hole 11. A through hole 201 is disposed on the common portion 21, and the piston rod 31 is movably disposed on the common portion 21. Thus, the radial load and impact force borne by the piston rod 31 during movement are applied to the common portion 21 and transmitted to the hole wall of the pressure relief hole 11 through the multiple separator ribs 25, improving the overall strength and deformation resistance of the separator 20. When the pressure inside the battery pack increases, the structure of the separator 20 reduces its deformation capacity, ensuring that the piston rod 31 can move stably along a predetermined trajectory, driving the cover portion 32 to accurately open or cover the pressure relief hole 11. This maintains the sealing reliability between the first seal and the first annular groove while ensuring pressure relief efficiency, effectively solving the sealing failure problem caused by insufficient structural strength of the separator.

[0065] like Figures 2 to 7 As shown, in the width direction of the partition ribs 25, the width of the common part 21 is greater than the width of a single partition rib 25. Thus, the volume of the common part 21 is larger than that of a single partition rib 25, increasing the structural strength of each partition rib 25 fixed at the common part 21. This enhances the deformation resistance of the partition frame 20 when subjected to the impact of depressurized gas during depressurization, allowing the common part 21 to stably support the piston rod 31 and preventing deformation caused by localized stress concentration.

[0066] The aforementioned common portion 21 is preferably an annular ring, and the width of the common portion 21 refers to the radial dimension between the inner and outer rings of the annular ring.

[0067] like Figures 2 to 7As shown, in the circumferential direction of the pressure relief hole 11, the second end of each partition rib 25 has a larger dimension than the first end. The connection area between the partition rib 25 and the wall of the pressure relief hole 11 has a larger contact area in the circumferential force direction, thereby improving the connection strength between the partition frame 20 and the wall of the pressure relief hole 11. Furthermore, the dimension of each partition rib 25 can form a gradual dimension from its first end to its second direction, so that the impact force on the common part 21 can be transmitted to the wall of the pressure relief hole 11 more quickly along the extension direction of the partition rib 25, effectively preventing the partition rib 25 from undergoing local deformation or breakage, so that the partition frame 20 can stably support the piston rod 31, and the pressure in the central area of ​​the pressure relief hole 11 can quickly push the cover plate part 32 to relieve pressure.

[0068] like Figures 2 to 7 As shown, in the axial direction C of the pressure relief hole 11, the thickness of the partition frame 20 is greater than or equal to 2 mm and less than or equal to 5 mm. The width W1 mm ​​of the partition rib 25 is greater than or equal to 3 mm and less than or equal to 6 mm. The above-mentioned thickness and width ranges enable the partition frame 20 to maintain sufficient structural strength and deformation resistance under the impact of the pressure relief gas, thereby ensuring that the contour of the pressure relief channel 111 remains stable during the pressure relief process, preventing the pressure relief path from being disordered due to the deformation of the pressure relief channel 111 caused by the deformation of the partition frame 20; at the same time, the above-mentioned thickness and width ranges, together with the product of the first ratio M and the second ratio J, make the load applied to the first sealing element 50 by the cover plate 32 uniformly distributed during the opening or closing process, effectively avoiding local stress concentration caused by the deformation of the partition frame 20, significantly reducing the risk of sealing failure of the first sealing element 50, thereby ensuring the reliability of the seal while ensuring the pressure relief efficiency.

[0069] The thickness of the aforementioned divider 20 is preferably any one of 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm or 5.0mm, or a value between any two of these values.

[0070] The width W1mm of the aforementioned partition rib 25 is preferably any value among 3.0mm, 3.5mm, 4.0mm, 4.5mm, 5.0mm, 5.5mm or 6.0mm, or a value between any two values.

[0071] like Figures 2 to 7As shown, multiple partition ribs 25 are radially distributed, and the second ends of all partition ribs 25 are connected to the wall of the pressure relief hole 11 at intervals along the circumference of the pressure relief hole 11. In this way, a radially distributed partition frame 20 structure is formed inside the pressure relief hole 11. This structure allows the pressure generated during the pressure relief process to be transmitted synchronously and evenly to the wall of the pressure relief hole 11 through multiple partition ribs 25, effectively dispersing local stress and avoiding local deformation of the partition ribs 25 due to pressure concentration, thus ensuring the stability of the outline shape of the pressure relief channel 111. At the same time, the radially distributed partition frame 20 structure enhances the overall compressive strength of the partition frame 20, so that the partition frame 20 always maintains structural stability when the cover plate part 32 is opened or covered by the pressure relief hole 11, thereby ensuring the sealing reliability of the first seal in the first annular groove.

[0072] like Figures 2 to 7 As shown, the second ends of all the partition ribs 25 are connected to the wall of the pressure relief hole 11 at intervals along the circumference of the pressure relief hole 11. A fixing part 16 is provided on the outer peripheral surface 103 of the valve body 10. The fixing part 16 is used to fix and connect to the frame of the battery pack. The extending direction of at least one partition rib 25 does not intersect with the fixing part 16. When the pressure relief valve of the box is depressurized, the partition rib 25 can be staggered from the fixing position of the fixing part 16 on its force path, so as to avoid the stress at the fixing point of the fixing part 16 being directly transmitted to the partition rib 25, thereby effectively avoiding stress concentration, reducing the possibility of the partition rib 25 breaking under concentrated stress, and ensuring that the partition frame 20 always maintains structural stability.

[0073] like Figures 2 to 5 As shown, the explosion-proof valve also includes a mounting cylinder 40 located within the pressure relief hole 11 and fixedly connected to the partition frame 20. The mounting cylinder 40 is sleeved around the piston rod 31 and is welded or bonded to the partition frame 20. This ensures that the mounting cylinder 40 is reliably fixed to the partition frame 20. Furthermore, the friction and impact loads experienced by the piston rod 31 during its reciprocating movement within the pressure relief hole 11 are directly borne by the mounting cylinder 40, rather than directly transmitted to the partition frame 20. This avoids direct contact between the piston rod 31 and the partition frame 20, thereby reducing the risk of structural failure due to stress concentration in the partition frame 20 and extending the service life of the explosion-proof valve.

[0074] like Figures 2 to 5As shown, the piston rod 31 is preferably a piston rod connected to the cover plate portion 32, and a stop ring is provided on the piston rod. The stop ring is located at the end of the piston rod away from the cover plate portion 32, and the two ends of the spring 33 abut against the common portion 21 and the stop ring, respectively. The spring 33 is preferably a compression spring. When the spring 33 always applies a spring force to the stop ring, and no depressurized gas pushes the cover plate portion 32, the piston rod always pulls the cover plate portion 32 under the action of the spring force of the spring 33, and the cover plate portion 32 can always maintain a stop engagement with the stop wall, so that the cover plate portion 32 is stably kept in the position of closing the pressure relief hole 11. When depressurized gas pushes the cover plate portion 32, the depressurized gas overcomes the spring force applied by the spring 33 to the stop ring. At this time, the spring 33 is compressed and stores force, the cover plate portion 32 drives the piston rod to move, and the cover plate portion 32 opens the pressure relief hole 11. When the cover plate 32 loses the pressure relief gas, it cannot overcome the spring force of the spring 33. Under the action of the spring force accumulated by the spring 33, the stop ring is pulled by the piston rod to move the cover plate 32. The cover plate 32 returns from the position of opening the pressure relief hole 11 to the position of closing the pressure relief hole 11 to prevent foreign objects from entering the pressure relief hole 11.

[0075] In this application, for ease of processing and forming, and for ease of subsequent structural installation, the pressure relief hole includes a first hole segment and a second hole segment coaxial with and connected to the first hole segment. The diameter of the second hole segment is larger than the diameter of the first hole segment. A stop wall is formed between the first hole segment and the second hole segment. The partition frame 20 is connected to the hole wall of the first hole segment. The stop wall is located on the second end face 102. When the cover plate portion 32 is reset from the position of opening the pressure relief hole 11 to the position of covering the pressure relief hole 11, the cover plate portion 32 and the stop wall stop and cooperate. The second annular groove is provided on the stop wall.

[0076] like Figures 1 to 7 As shown, the first ratio M is greater than or equal to 0.044 and less than or equal to 0.333. When the first ratio M is less than 0.044, the first annular groove 14 is not positioned sufficiently, and the narrower first sealing element 50 does not provide a good seal for the explosion-proof valve, resulting in insufficient airtightness of the battery pack. When the first ratio M is greater than 0.333, the excessively wide first annular groove 14 encroaches on the space available for a pressure relief hole on the explosion-proof valve, resulting in insufficient venting space and a slow pressure relief speed. Thus, the first ratio M is controlled within the range of 0.044 to 0.333 to ensure that the size of the first sealing element within the first annular groove 14 is within a reasonable range, avoiding insufficient airtightness and insufficient venting space of the battery pack, and improving the pressure relief speed. More preferably, the first ratio M is greater than or equal to 0.076 and less than or equal to 0.244, which better guarantees both the sealing performance and pressure relief capacity of the explosion-proof valve.

[0077] The second ratio J is greater than or equal to 0.1 and less than or equal to 0.25. When the second ratio J is less than 0.1, the support effect of the partition frame on the cover plate 32 is poor, making it prone to deformation (because the spring is always pressing against the partition frame), resulting in the accidental opening of the explosion-proof valve of the enclosure and a decrease in sealing performance, allowing moisture to easily enter the pressure relief hole 11. When the second ratio J is greater than 0.25, the pressure relief opening of the cover plate 32 is small, resulting in a poor pressure relief rate. Thus, the second ratio J is controlled within the range of 0.1 to 0.25, so that the size of the partition frame occupies a reasonable space in the pressure relief hole 11, improving the structural strength of the partition frame, preventing the accidental opening of the explosion-proof valve of the enclosure, and improving the sealing performance of the first sealing element, preventing moisture from easily entering the pressure relief hole 11. The pressure relief opening of the cover plate 32 is also reasonable, resulting in a more reasonable pressure relief rate. More preferably, the second ratio J is greater than or equal to 0.12 and less than or equal to 0.22, so that the structural strength and pressure relief rate of the explosion-proof valve itself can be better guaranteed.

[0078] The first ratio M is preferably any one of 0.044, 0.064, 0.084, 0.104, 0.124, 0.144, 0.164, 0.184, 0.204, 0.224, 0.244, 0.264, 0.284, 0.304, 0.324, or 0.333, or a value between any two values.

[0079] The second ratio J mentioned above is preferably any one of 0.1, 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24 or 0.25, or a value between any two values.

[0080] The width of the first annular groove 14 is greater than or equal to 1.5 mm and less than or equal to 5 mm, preferably any value among 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm or 5.0 mm or a value between any two values.

[0081] The radius of the aforementioned pressure relief hole 11 is greater than or equal to 15 mm and less than or equal to 34 mm, preferably any value among 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm or 34 mm or a value between any two of these values.

[0082] The first ratio M mentioned above is greater than or equal to 0.044 and less than or equal to 0.333, preferably any value among 0.044, 0.074, 0.104, 0.134, 0.164, 0.194, 0.224, 0.254, 0.284, 0.314 or 0.044, or a value between any two values.

[0083] The area of ​​the first projection mentioned above is greater than or equal to 70.65 mm². 2 And less than or equal to 907.46 mm 2 The preferred size is 70.65mm. 2 , 75.0mm², 100.0mm², 125.0mm², 150.0mm², 175.0mm², 200.0mm², 225.0mm², 250.0mm², 275.0m m², 300.0mm², 325.0mm², 350.0mm², 375.0mm², 400.0mm², 425.0mm², 450.0mm², 475.0mm², 500. 0mm², 525.0mm², 550.0mm², 575.0mm², 600.0mm², 625.0mm², 650.0mm², 675.0mm², 700.0mm², 725.0mm², 750.0mm², 775.0mm², 800.0mm², 825.0mm², 850.0mm², 875.0mm², 900.0mm², or 907.46mm 2 It can be any value in the range or a value between any two values.

[0084] The area of ​​the second projection mentioned above is greater than or equal to 706.5 mm². 2 And less than or equal to 3629.84mm 2 The preferred size is 706.5mm. 2 750.0mm², 1000.0mm², 1250.0mm², 1500.0mm², 1750.0mm², 2000.0mm², 2250.0mm², 2500.0mm², 2750.0mm², 3000.0mm², 3250.0mm², 3500.0mm², or 3629.84mm 2 It can be any value in the range or a value between any two values.

[0085] The second ratio J mentioned above is greater than or equal to 0.1 and less than or equal to 0.25, preferably any value among 0.1, 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24 or 0.25 or a value between any two values.

[0086] According to another aspect of this application, a battery pack is provided, such as Figures 8 to 13 As shown, one embodiment of the battery pack includes a base plate 62, a frame 61 surrounding the edge of the base plate 62, a housing explosion-proof valve 1 disposed on the frame 61, and a battery 70 disposed within the frame 61. The base plate 62 and the frame 61 together form a housing, and the housing explosion-proof valve is the aforementioned housing explosion-proof valve. Since the aforementioned housing explosion-proof valve solves the problem of sealing failure in housing explosion-proof valves in related technologies, the battery pack including this housing explosion-proof valve can solve the same technical problem.

[0087] The aforementioned enclosure can be formed by splicing together multiple beams. The enclosure includes four sub-frames, which are joined end-to-end to form an enclosed space. This enclosed space is sealed by a top cover and a bottom plate to form a accommodating cavity. The enclosure can be made of various materials, such as aluminum alloy, copper alloy, steel, or plastic. The enclosure can be rectangular, circular, polygonal, etc., with no specific limitation. The enclosure contains an internal cavity.

[0088] The aforementioned base plate is the main load-bearing component of the battery pack, typically referring to the structural member installed at the bottom of the battery pack. It supports and secures the battery pack, battery management system, cooling system, and other components inside the pack. The base plate is located at the bottom of the enclosure frame, for example, by welding, riveting, or screwing. The base plate can be made of various materials, such as high-strength materials like aluminum alloy, steel, and stainless steel. It can be rectangular, circular, polygonal, or a plate-like structure; the specific shape is not limited, and its dimensions are determined by the number and size of the battery cells housed in the battery pack.

[0089] like Figures 8 to 13 As shown, the enclosure 61 includes an outer wall 611 and an inner wall 612 disposed opposite to each other. A cavity 614 is formed between the outer wall 611 and the inner wall 612. An installation hole 613 is provided on the outer wall 611, and the piston rod 31 passes through the installation hole 613. The valve body 10 is fixed to the outer wall 611. When the cover plate 32 covers the pressure relief hole 11, the explosion-proof valve of the enclosure blocks the installation hole 613. When the cover plate 32 covers the pressure relief hole 11, the explosion-proof valve of the enclosure completely blocks the installation hole 613, ensuring the sealing reliability and structural stability between the explosion-proof valve of the enclosure and the enclosure. Furthermore, by fixing the valve body 10 to the outer wall 611 and using the piston rod 31 to cooperate with the mounting hole 613 for positioning, when the cover plate 32 covers the pressure relief hole 11, the valve body 10 is tightly fitted to the outer wall 611, which not only maintains the sealing state, but also allows the pressure relief gas to pass through the cavity 614 and act on the cover plate 32 when pressure relief gas is generated in the battery pack, so that the cover plate 32 can be opened in time to relieve pressure.

[0090] like Figures 8 to 13As shown, the first sealing element 50 is located on the outer side of the mounting hole 613 in the radial direction, and the distance between the first sealing element 50 and the wall surface of the mounting hole 613 is greater than 0 mm. This structural arrangement ensures that when the explosion-proof valve 1 is installed on the outer wall 611, the first sealing element 50 does not contact the wall surface of the mounting hole 613, thus avoiding interference with the mounting hole 613 and preventing any impact on the installation of the piston rod 31 or the discharge of depressurized gas. Furthermore, the fact that the first sealing element 50 does not contact the wall surface of the mounting hole 613 provides deformation space for the first sealing element 50, facilitating a good sealing performance after the valve body 10 is tightly fitted to the outer wall 611.

[0091] like Figures 8 to 13 As shown, there are multiple explosion-proof valves 1 in the enclosure, which are spaced apart along the circumference of the frame 61. The distance between any two adjacent explosion-proof valves 1 in the circumference of the frame 61 is greater than or equal to 50mm and less than or equal to 2500mm. This distance range ensures that the pressure relief rate of each explosion-proof valve is accurately controlled in the event of thermal runaway. When multiple pressure relief channels open in tandem, the pressure release is uniform and stable, effectively preventing the partition frame 20 from breaking due to stress concentration. Simultaneously, it ensures that the depressurized gas can be discharged promptly and fully from the pressure relief channels, achieving a balance between safe pressure relief and structural strength. This avoids the large impact that could damage the partition frame due to a concentrated activation of a single explosion-proof valve 1 causing a localized pressure increase. Therefore, it achieves balanced and timely circumferential pressure relief of the entire frame 61, and also avoids weakening the structural strength of the frame 61 due to excessively close proximity of the mounting holes 613.

[0092] The preferred distance between any two adjacent explosion-proof valves 1 in the aforementioned enclosures is 50mm, 100mm, 150mm, 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, 550mm, 600mm, 650mm, 700mm, 750mm, 800mm, 850mm, 900mm, 950mm, 1000mm, 1050mm, 1100mm, 1150mm, 1200mm, 1250mm, or 1300mm. The value of 1350mm, 1400mm, 1450mm, 1500mm, 1550mm, 1600mm, 1650mm, 1700mm, 1750mm, 1800mm, 1850mm, 1900mm, 1950mm, 2000mm, 2050mm, 2100mm, 2150mm, 2200mm, 2250mm, 2300mm, 2350mm, 2400mm, 2450mm, or 2500mm, or a value between any two of these values.

[0093] like Figures 8 to 13As shown, the battery 70 has a bottom surface facing the base plate 62, on which a battery explosion-proof valve 71 is disposed. An exhaust channel 72 connecting the battery explosion-proof valve 71 and the cavity 614 is disposed within the base plate 62. The second ratio J is greater than or equal to 0.12 and less than or equal to 0.25. When the battery 70 experiences thermal runaway, the depressurized gas generated can be directionally introduced into the cavity 614 through the exhaust channel 72, preventing gas from accumulating in localized areas within the enclosure 61. Meanwhile, the second ratio J is limited to the range of 0.12 to 0.25, indicating that the structural strength of the partition frame 20 and the flow area of ​​the pressure relief channel 111 are controlled within a reasonable size range. This ensures that the battery explosion-proof valve 71 has sufficient structural strength when the partition frame 20 is subjected to gas pressure. At the same time, the pressure relief channel 111 maintains sufficient exhaust space, allowing the pressure relief gas to diffuse evenly in the cavity 614 and be discharged through multiple pressure relief channels 111. This effectively prevents the partition frame 20 from deforming or breaking due to local pressure, and also reduces the possibility of the frame 61 deforming due to the deformation or breakage of the partition frame 20.

[0094] The second ratio J mentioned above is preferably any one of 0.12, 0.135, 0.15, 0.165, 0.18, 0.195, 0.21, 0.225, 0.24 or 0.25, or a value between any two values.

[0095] The aforementioned battery can store chemical energy and controllably convert it into electrical energy. In recyclable batteries, the active materials can be reactivated by charging after discharge, allowing for continued use. The battery includes a casing and battery cells housed within the casing.

[0096] The aforementioned battery explosion-proof valve refers to a component or part that can be actuated to release internal pressure or temperature when the battery's internal pressure or temperature reaches a predetermined threshold. During battery use, the battery explosion-proof valve is mainly used to prevent excessive pressure buildup that could cause deformation or explosion in the event of thermal runaway or other situations. It allows gas to escape from the battery, thus reducing internal pressure. The material of the battery explosion-proof valve is not limited, including but not limited to aluminum, steel, and alloys. The shape of the battery explosion-proof valve is not limited, and it can be square, oblong, elliptical, racetrack-shaped, etc. The type of battery explosion-proof valve is not limited, such as a notched battery explosion-proof valve, which can be formed by stamping or laser etching.

[0097] In this application, a flow guide 63 is provided on the outer wall 611, which covers the explosion-proof valve of the enclosure. In this way, the flow guide 63 can guide the pressure relief gas ejected from the explosion-proof valve of the enclosure in a specific direction, preventing the pressure relief gas ejected from the explosion-proof valve of the enclosure from flowing in no direction and causing a chain risk of thermal runaway.

[0098] The performance of the explosion-proof valves on the enclosures obtained in Examples 1 to 16 and Comparative Examples 1 and 2 was tested, and the performance is shown in Table 1.

[0099] Table 1

[0100]

[0101] As can be seen from the data comparison in Table 1, by adopting the technical solutions of Embodiments 1 to 16 of the present invention, the battery pack's casing sealing performance can be controlled to be good or qualified by reasonably selecting the values ​​of the six parameters. This ensures sufficient airtightness, prevents sealing failure of the gap between the valve body 10 and the frame, and reduces the possibility of thermal runaway in other batteries, avoiding the risk of cascading thermal runaway within the frame. Embodiments 4 to 11, in particular, can balance good casing sealing performance with preventing thermal runaway in other batteries. The aforementioned "other batteries" refer to batteries other than those subject to actively induced thermal runaway.

[0102] By comparing the data from Examples 12-14, Example 16, and Comparative Example 1, it can be seen that when M×J satisfies: 60.88×10 -3 ≤M×J≤75.00×10 -3 At that time, the battery pack casing has good sealing performance and sufficient airtightness, preventing sealing failure of the gap between the valve body 10 and the frame. Furthermore, there is a risk of thermal runaway in at least one of the other batteries, which is considered a qualified condition. The maximum design value of the second ratio J is 0.25. When M×J satisfies: 75.00×10 -3 <M×J≤81.48×10 -3 At that time, as can be seen from the values ​​of Comparative Example 1, the battery pack's casing sealing performance is good, but more than one of the other batteries is at risk of thermal runaway, which is considered a non-compliance.

[0103] By comparing the data from Examples 1-3, Example 15, and Comparative Example 2, it can be seen that when M×J satisfies: 5.72×10 -3 ≤M×J≤8.44×10 -3 At that time, the battery pack's casing sealing performance was qualified, with sufficient airtightness to prevent sealing failure of the gap between the valve body 10 and the frame, and there was no risk of thermal runaway in other batteries, which is considered a good situation. The minimum designable value for the first ratio M is 0.044; when M×J satisfies: 4.67×10 -3 ≤M×J<5.72×10 -3 At that time, as can be seen from the values ​​of Comparative Example 2, the sealing performance of the battery pack casing is unqualified, but there is no risk of thermal runaway in other batteries, which is considered a good situation.

[0104] It should be noted that the dimensions of the explosion-proof valve housing in this application can be measured using measuring instruments such as micrometers or calipers, measuring parameters such as length, width, distance, thickness, and diameter. The area is calculated from the measured parameters such as length, width, distance, thickness, and diameter. The area of ​​the first projected portion can be measured using basic calculation methods such as the grid method, segmentation method, and cut-and-paste method to calculate the area of ​​each pressure relief channel 111 and sum them to obtain the area of ​​the first projected portion. The pressure relief hole 11 has a radius r1, and the area of ​​the second projected portion = π × r1. 2 .

[0105] The testing process for the sealing performance of the battery pack enclosure is as follows:

[0106] The battery pack is manufactured by including a base plate, a frame surrounding the edge of the base plate, and the base plate and frame forming a receiving cavity. It also includes a cover to seal the receiving cavity. Batteries manufactured according to the above method are arranged in the battery pack. For the explosion-proof valves in each embodiment and comparative example, a mounting hole for installing the explosion-proof valve is provided on one side of the frame. The diameter of the mounting hole is larger than the diameter of the pressure relief hole 11 and smaller than the diameter of the inner wall of the first annular groove 14. The explosion-proof valve is then attached to the corresponding battery pack. Except for the size of the mounting hole, the other structures of the battery pack are completely identical. A battery pack without a mounting hole is then used as a reference sample.

[0107] According to the test standard for waterproof performance of battery packs in GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles", the reference sample was subjected to an immersion test to ensure that the waterproof performance of the reference sample met the IP68 level.

[0108] Next, the battery packs corresponding to the explosion-proof valves of the enclosures in each embodiment and comparative example were tested according to the test standards for the waterproof performance of battery packs in GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles". If the test results show that the battery pack meets the IP68 level, it is recorded as good; if the test results show that the battery pack meets the IP67 level, it is recorded as qualified; if the test results show that the battery pack does not meet the IP67 standard, it is recorded as unqualified.

[0109] The testing process for other batteries to determine whether thermal runaway occurs is as follows:

[0110] Prepare two hundred batteries and stack them in a battery pack housing. An explosion-proof valve, corresponding to those in the embodiment and comparative example, is installed on the edge of the battery pack housing. The battery terminals are electrically connected via conductive strips, and a heating element is placed on the large side of the casing of one battery at the same location.

[0111] The battery pack is charged at a constant current rate of 1C until the battery voltage reaches the upper limit. Then, it is switched to constant voltage charging until the battery current drops to 0.05C. After resting for 30 minutes, the battery is heated at the maximum power of the heating element. If thermal runaway occurs, the triggering is stopped and the heating element is turned off. After the thermal runaway process of the battery pack ends, it is allowed to stand for 2 hours. Then, the battery pack is opened to check if any other batteries in the pack have also experienced thermal runaway, specifically whether the battery explosion-proof valve has opened. If no other batteries in the battery pack have experienced thermal runaway, it is recorded as good; if the total number of batteries with thermal runaway (excluding the battery with actively induced thermal runaway) is less than or equal to 1, it is recorded as qualified; if more than 1 battery has experienced thermal runaway, it is recorded as unqualified.

[0112] For different systems, the upper and lower voltage limits of a single battery need to be adjusted accordingly: Lithium iron phosphate (LFP) - upper limit voltage 3.65V, lower limit voltage 2.5V; Nickel-cobalt-manganese ternary NCM - upper limit voltage 4.25V, lower limit voltage 2.5V; Lithium manganese iron phosphate (LFMP) - upper limit voltage 4.25V, lower limit voltage 2.5V; Lithium nickel manganese oxide - upper limit voltage 4.8V, lower limit voltage 3.5V.

[0113] The positive electrode active material used in this test was selected from LiNi. 0.6 Co 0.2 Mn 0.2 Taking O2 as an example, other positive electrode materials all meet the above test requirements, and the mass ratio of positive electrode active material: conductive agent: binder meets 96:2:2; the negative electrode active material is selected from artificial graphite, and the ratio of negative electrode active material: conductive agent: thickener: binder meets 95:2:1:2.

[0114] The battery pack in this application includes a battery pack composed of multiple batteries connected in series and / or parallel, a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (casing, brackets, etc.), and protective components. These components are placed inside a battery housing and sealed with a cover, forming a complete functional unit capable of directly outputting electrical energy. The battery pack, as a rechargeable battery, is the power source for new energy vehicles. A battery pack generally includes cell modules, a battery management system (BMS) control module, and a battery housing that houses the cell modules and the BMS control module. The battery pack includes a battery housing and multiple batteries housed within it. The battery housing is divided into upper and lower parts; the upper part includes a cover, and the lower part includes a frame and a base plate, with the two parts sealed together. The battery pack includes at least two cell units, a BMS control assembly, and a battery housing. A battery pack generally includes a battery housing and battery modules; the battery housing consists of a lower battery housing composed of a frame, a base plate, and a cover. A battery pack typically includes a battery housing, a battery, and a separator. Both the battery and the separator are located inside the battery housing. The separator is located on the side of the battery away from the bottom plate of the battery housing, separating the battery from other components located above it, thus providing isolation.

[0115] Battery pack fabrication: The battery pack casing is manufactured, consisting of a base plate, a frame, and a cover. The casing can be formed by casting, stamping, or extrusion of materials such as steel plates or aluminum alloys, or by using lightweight materials such as glass fiber reinforced composites or carbon fiber reinforced composites. The base plate is located at the bottom of the frame, for example, by welding, riveting, or screwing. The batteries are fixed to the casing, and after connecting each battery via a high-voltage busbar, the casing is sealed with the cover, thus completing the battery pack.

[0116] According to another aspect of this application, an electrical device is provided, including a battery pack, which is the battery pack described above. Since the battery pack described above can solve the problem of sealing failure of the explosion-proof valve in the enclosure in related technologies, the electrical device including this battery pack can solve the same technical problem. The battery pack described above can provide electrical energy to the electrical device.

[0117] The electrical devices covered in this application include, but are not limited to, vehicles, mobile phones, tablets, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be fuel-powered vehicles, natural gas vehicles, new energy vehicles, or rail vehicles; new energy vehicles can be pure electric vehicles, hybrid vehicles, or range-extended vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. When the electrical device is a vehicle, the battery pack can be located at the bottom, front, or rear of the vehicle.

[0118] In the description of this invention, it should be understood that "a plurality of" means two or more. Directional terms such as "front, back, up, down, left, right," "horizontal, vertical, horizontal," and "top, bottom" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner or outer contours relative to the outline of each component itself.

[0119] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0120] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0121] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A box explosion relief valve characterized by, include: The valve body (10) includes a first end face (101) and a second end face (102) disposed opposite to each other. A pressure relief hole (11) is provided on the valve body (10). The pressure relief hole (11) passes through the first end face (101) and the second end face (102) along its axis (C). A first annular groove (14) is provided on the first end face (101). The first sealing element (50) is disposed within the first annular groove (14); A partition (20) is connected to the wall of the pressure relief hole (11) and divides the pressure relief hole (11) into at least two pressure relief channels (111). The partition (20) forms a first projection on a plane parallel to the first end face (101), and the area enclosed by the wall of the pressure relief hole (11) forms a second projection on a plane parallel to the first end face (101). A piston rod (31) is movably disposed on the partition frame (20), and the partition frame (20) is provided with a through hole (201) through which the piston rod (31) passes. The piston rod (31) is slidably connected to the partition frame (20). The cover plate (32) is fixedly connected to the piston rod (31). The cover plate (32) is located on the side of the second end face (102) away from the first end face (101). When the piston rod (31) moves, it drives the cover plate (32) to open or cover the pressure relief hole (11). Spring (33), the two ends of which abut against the separator (20) and the piston rod (31) respectively. Wherein, the ratio of the width of the first annular groove (14) to the radius of the pressure relief hole (11) is a first ratio M, the ratio of the area of ​​the first projection to the area of ​​the second projection is a second ratio J, and the product of the first ratio M and the second ratio J, M×J, is greater than or equal to 5.72×10 -3 And less than or equal to 75 × 10 -3 .

2. The box explosion relief valve of claim 1, wherein, In the radial direction of the pressure relief hole (11), the inner ring surface of the first annular groove (14) is spaced apart from the hole wall surface of the pressure relief hole (11).

3. The box explosion relief valve of claim 2, wherein, The inner ring surface of the first annular groove (14) is spaced apart from the hole wall surface of the pressure relief hole (11) by a first distance H1mm, wherein the first distance H1mm is greater than or equal to 0.6mm and less than or equal to 5mm.

4. The box explosion relief valve of claim 1, wherein, In the radial direction of the pressure relief hole (11), the minimum distance H2mm between the outer ring surface of the first annular groove (14) and the outer peripheral surface (103) of the valve body (10) is greater than or equal to 0.6mm and less than or equal to 5mm.

5. The explosion-proof valve for a housing according to claim 1, characterized in that, The first sealing element (50) includes an annular portion (51) and a protrusion (52) disposed on the annular portion (51). In the radial direction of the pressure relief hole (11), the width of the annular portion (51) is smaller than the groove width of the first annular groove (14). Wherein, in the radial direction of the pressure relief hole (11), the protrusion (52) protrudes outward from the outer side of the annular portion (51) toward the outer ring surface of the first annular groove (14); and / or, in the radial direction of the pressure relief hole (11), the protrusion (52) protrudes outward from the inner side of the annular portion (51) toward the inner ring surface of the first annular groove (14).

6. The explosion-proof valve for a housing according to claim 5, characterized in that, In the radial direction of the pressure relief hole (11), the protrusion (52) protrudes from the outer surface of the annular portion (51) by a distance greater than or equal to 0.3 mm and less than or equal to 1 mm toward the outer ring surface of the first annular groove (14); and / or, in the radial direction of the pressure relief hole (11), the protrusion (52) protrudes from the inner surface of the annular portion (51) by a distance greater than or equal to 0.3 mm and less than or equal to 1 mm toward the inner ring surface of the first annular groove (14).

7. The box explosion relief valve of claim 5, wherein, There are multiple protrusions (52), and the multiple protrusions (52) are arranged at intervals along the circumference of the annular portion (51). In the circumference of the annular portion (51), the distance between any two adjacent protrusions (52) is greater than or equal to 8 mm and less than or equal to 20 mm.

8. The box explosion relief valve of claim 1, wherein, The second end face (102) is provided with a second annular groove (15). The explosion-proof valve of the box also includes a second sealing element (53). The second sealing element (53) is disposed in the second annular groove (15). When the cover plate part (32) abuts and cooperates with the second sealing element (53), the cover plate part (32) covers the pressure relief hole (11).

9. A box explosion relief valve according to claim 8, characterised in that The width of the second annular groove (15) is less than or equal to the width of the first annular groove (14); and / or, the depth of the second annular groove (15) is less than or equal to the depth of the first annular groove (14).

10. The box explosion relief valve of claim 8, wherein, The first annular groove (14) and the second annular groove (15) form a third projection and a fourth projection respectively on a plane parallel to the first end face (101), and the third projection and the fourth projection do not overlap at least partially.

11. The explosion-proof valve for a housing according to claim 8, characterized in that, In the radial direction of the pressure relief hole (11), the inner wall of the first annular groove (14) and the inner wall of the pressure relief hole (11) have a first radial dimension, and the inner wall of the second annular groove (15) and the inner wall of the pressure relief hole (11) have a second radial dimension, wherein the first radial dimension is greater than the second radial dimension.

12. A box explosion relief valve according to any one of claims 1 to 11, characterized in that The partition frame (20) includes a common part (21) disposed in the pressure relief hole (11) and a plurality of partition ribs (25). The first end of each partition rib (25) is fixedly connected to the common part (21), and the second end of each partition rib (25) is fixedly connected to the inner side wall of the pressure relief hole (11). The through hole (201) is disposed in the common part (21), and the piston rod (31) is movably disposed in the common part (21).

13. The box explosion relief valve of claim 12, wherein, In the width direction of the partition rib (25), the width of the common part (21) is greater than the width of a single partition rib (25).

14. The box explosion relief valve of claim 12, wherein, In the circumferential direction of the pressure relief hole (11), the second end of each of the partition ribs (25) is larger than the first end of the partition rib (25).

15. The box explosion relief valve of claim 12, wherein, In the direction of the axis (C) of the pressure relief hole (11), the thickness of the partition frame (20) is greater than or equal to 2 mm and less than or equal to 5 mm; and / or, the width of the partition rib (25) is greater than or equal to 3 mm and less than or equal to 6 mm.

16. The box explosion relief valve of claim 12, wherein, The plurality of the partition ribs (25) are radially distributed, and the second ends of all the partition ribs (25) are connected to the wall of the pressure relief hole (11) at intervals along the circumference of the pressure relief hole (11).

17. The box explosion relief valve of claim 16, wherein, A fixing part (16) is provided on the outer peripheral surface (103) of the valve body (10). The fixing part (16) is used to fix and connect with the frame of the battery pack. The extending direction of at least one of the partition ribs (25) does not intersect with the fixing part (16).

18. The box explosion relief valve according to any one of claims 1 to 11, characterized in that The first ratio M is greater than or equal to 0.044 and less than or equal to 0.333; and / or, the second ratio J is greater than or equal to 0.1 and less than or equal to 0.

25.

19. A battery pack, comprising a base plate (62), a frame (61) surrounding the edge of the base plate (62), a box explosion-proof valve (1) disposed on the frame (61), and a battery (70) disposed within the frame (61), characterized in that, The explosion-proof valve for the enclosure is the explosion-proof valve for the enclosure as described in any one of claims 1 to 18.

20. The battery pack of claim 19, wherein, The frame (61) includes an outer wall (611) and an inner wall (612) arranged opposite to each other, a cavity (614) is formed between the outer wall (611) and the inner wall (612), a mounting hole (613) is provided on the outer wall (611), the piston rod (31) passes through the mounting hole (613), and the valve body (10) is fixed on the outer wall (611).

21. The battery pack of claim 20, wherein, The first seal (50) is located on the outer side of the mounting hole (613) in the radial direction, and the distance between the first seal (50) and the hole wall of the mounting hole (613) is greater than 0 mm.

22. The battery pack of claim 19, wherein, There are multiple explosion-proof valves (1) in the enclosure, and the multiple explosion-proof valves (1) are arranged at intervals along the circumference of the frame (61). In the circumference of the frame (61), the distance between any two adjacent explosion-proof valves (1) is greater than or equal to 50 mm and less than or equal to 2500 mm.

23. The battery pack of claim 20, wherein, The battery (70) has a bottom surface facing the base plate (62), and a battery explosion-proof valve (71) is provided on the bottom surface. An exhaust channel (72) connecting the battery explosion-proof valve (71) and the cavity (614) is provided in the base plate (62). The second ratio J is greater than or equal to 0.12 and less than or equal to 0.

25.

24. An electrically powered device comprising a battery pack, characterized in that The battery pack is the battery pack according to any one of claims 19 to 23.

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