Battery box assembly, battery pack and electric device

Abstract

This invention provides a battery housing assembly, a battery pack, and an electrical device, relating to the field of battery technology. The battery housing assembly includes: a side beam; an exhaust chamber formed between a first wall and a second wall; a first through hole communicating with the exhaust chamber on the first wall; and a ratio E between the wall thickness of the first wall and the maximum width of the exhaust chamber in the direction from the inside to the outside of the side beam. A housing pressure relief valve includes a body, a movable rod movably mounted on the body, and a cover plate fixedly connected to the movable rod. When the cover plate is at its furthest position with the first communicating hole open, in the direction from the second wall to the first wall, the cover plate is farther from the second communicating hole, and the minimum distance between the side of the cover plate facing the second communicating hole and the first hole wall surface of the second communicating hole is a distance B mm. The ratio E, the distance B mm, and the diameter R mm of the first through hole satisfy the following condition: 0.5710. ‑4 ≤E / (BR)≤11.0810 ‑4 This addresses the issue of deformation easily occurring in the side beams where pressure relief valves are installed in the housing, a problem found in related technologies.

Description

Technical Field

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

[0002] The battery pack is equipped with a pressure relief valve to release the high-temperature and high-pressure gas inside the battery pack in the event of thermal runaway. The pressure relief valve is usually installed by opening a through hole in the side beam of the battery pack housing.

[0003] During the use of the battery pack, it was found that the side beam where the pressure relief valve of the housing is located is prone to deformation and even breakage. Summary of the Invention

[0004] The main objective of this invention is to provide a battery housing assembly, a battery pack, and an electrical device to solve the problem in related technologies where the side beams with pressure relief valves are prone to deformation.

[0005] To achieve the above objectives, according to one aspect of the present invention, a housing assembly is provided, comprising: a side beam, the side beam including a first wall and a second wall spaced apart along its outer to its inner direction, an exhaust chamber formed between the first wall and the second wall, a first through hole communicating with the exhaust chamber on the first wall, and a ratio E between the wall thickness of the first wall and the maximum width of the exhaust chamber along the direction from the inner to the outer side of the side beam; and a housing pressure relief valve, including a body, a movable rod movably disposed on the body, and a cover plate fixedly connected to the movable rod, the body being fixedly disposed on the outer side of the first wall, and a first connecting hole communicating with the first through hole on the body. A second connecting hole is coaxial with and connected to the first connecting hole. The diameter of the second connecting hole is larger than that of the first connecting hole. A movable rod passes through the first connecting hole. When the movable rod moves, it allows the cover plate to open or close the first connecting hole. When the cover plate closes the first connecting hole, at least part of the cover plate is located inside the second connecting hole. When the cover plate is at its furthest position with the first connecting hole open, from the second wall to the first wall, the cover plate is farther away from the second connecting hole. The minimum distance between the side of the cover plate facing the second connecting hole and the first hole wall of the second connecting hole is a distance B mm. The ratio E, the distance B mm, and the diameter R mm of the first connecting hole satisfy the following condition: 0.57. 10 -4 ≤E / (B R)≤11.08 10 -4 .

[0006] According to another aspect of the present invention, a battery pack is provided, including a battery housing assembly, a base plate and a battery, wherein the battery housing assembly is the battery housing assembly described above, the base plate is disposed at the bottom of a side beam and forms a receiving cavity with the side beam, and the battery is disposed in the receiving cavity.

[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, when the pressure relief valve of the housing does not reach the preset pressure, the cover plate closes the first connecting hole to prevent the battery pack's medium from leaking or being contaminated by the outside, thus ensuring the normal operation of the battery pack; when the pressure relief valve of the housing reaches the preset pressure, it pushes the cover plate to move away from the first connecting hole, and the cover plate opens the first through hole to achieve pressure relief. Wherein, when E / (B R) is less than 0.57 10 -4 When the thickness of the first wall is too small, or the minimum distance between the side of the cover plate facing the second connecting hole and the first hole wall of the second connecting hole is too large compared to the diameter of the first through hole, the portion of the first wall located in the exhaust chamber becomes too thin, resulting in low strength of the side beam of the pressure relief valve in the housing, making it prone to deformation or even breakage. When E / (B R) greater than 11.08 10 -4 If the thickness of the first wall is too large, or if the minimum distance between the side of the cover plate facing the second connecting hole and the first hole wall of the second connecting hole is too small compared to the diameter of the first through hole, the portion of the first wall located in the exhaust chamber will occupy a large space. This will reduce the pressure relief space of the pressure relief valve in the housing, increase the resistance of the pressure relief gas passing through the exhaust chamber, and slow down the pressure relief rate of the battery pack. Consequently, the internal temperature and pressure of the battery pack will be high, which may easily trigger a chain reaction of thermal runaway risks. Thus, E / (B R) controlled at 0.57 10 -4 Up to 11.08 10 -4 Within a certain range, this design avoids both excessive thinness and excessive thickness of the first wall located at the exhaust chamber. It also reasonably controls the size of the internal pressure relief space of the battery pack, effectively controlling the resistance of the pressure-relieved gas passing through the exhaust chamber. While ensuring timely pressure relief of the battery pack, it also guarantees the strength of the side beam where the pressure relief valve is located, reducing the possibility of deformation and preventing internal and external conductivity that could affect the safety of battery pack operation. Therefore, the technical solution of this application effectively solves the problem of deformation of the side beam where the pressure relief valve is located 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 of an embodiment of the battery pack according to the present invention is shown;

[0011] Figure 2 It shows Figure 1 A partial cross-sectional view of the battery compartment of the battery pack;

[0012] Figure 3 A three-dimensional structural schematic diagram of an embodiment of the battery pack according to the present invention is shown, with the battery not shown.

[0013] Figure 4 It shows Figure 3 A partial structural diagram of the battery pack housing after cross-section of the pressure relief valve.

[0014] Figure 5 It shows Figure 4 An enlarged view of point A1 of the battery pack;

[0015] Figure 6 It shows Figure 3 A partial cross-sectional view of the battery pack cover when the first connecting hole is closed;

[0016] Figure 7 It shows Figure 6 An enlarged view of point A2 of the battery pack;

[0017] Figure 8 It shows Figure 3 A partial cross-sectional view of the battery pack cover when the first connecting hole is opened;

[0018] Figure 9 It shows Figure 8 An enlarged view of the battery pack at point A3;

[0019] Figure 10 A three-dimensional structural schematic diagram of the cover plate of an embodiment of the battery pack housing pressure relief valve according to the present invention is shown when the first communication hole is closed;

[0020] Figure 11 A three-dimensional structural schematic diagram of the cover plate of an embodiment of the battery pack housing pressure relief valve according to the present invention is shown when the first communication hole is opened;

[0021] Figure 12 A cross-sectional view is shown of an embodiment of the housing pressure relief valve of the battery pack according to the present invention, with the cover plate closed when the first communication hole is closed;

[0022] Figure 13 A cross-sectional view is shown of the cover of an embodiment of the battery pack housing pressure relief valve according to the present invention when the first communication hole is opened;

[0023] Figure 14 A perspective view of an embodiment of the pressure relief valve for a battery pack according to the present invention is shown, without a cover plate.

[0024] Figure 15 It shows Figure 14 A side view of the pressure relief valve of the housing;

[0025] Figure 16 A three-dimensional structural schematic diagram from another perspective is shown of an embodiment of the battery pack housing pressure relief valve according to the present invention, with the cover plate closed at the first communication hole;

[0026] Figure 17 A side view schematic diagram of the side beam deformation test of the battery pack according to the present invention is shown;

[0027] Figure 18 A side view schematic diagram of the side beam deformation degree test of the battery pack according to the present invention is shown.

[0028] The above figures include the following reference numerals:

[0029] 1. Pressure relief valve of the housing; 10. Body; 101. Annular part; 11. First connecting hole; 111. Sub-connecting hole; 12. Second connecting hole; 13. Stop surface; 14. Receiving groove;

[0030] 20. Bridging section; 22. Groove;

[0031] 31. Moving rod; 32. Cover plate; 321. First cover surface; 322. Second cover surface; 33. Telescopic component;

[0032] 40. Install the cylinder;

[0033] 50. First seal; 51. Second seal;

[0034] 61. Side beam; 611. First wall; 612. Second wall; 613. First through hole; 614. Exhaust chamber; 62. Base plate; 63. Cavity; 64. Guide plate; 65. Second through hole; 66. Flow guide cover;

[0035] 70. Battery; 71. Battery explosion-proof valve; 72. First exhaust channel. Detailed Implementation

[0036] 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.

[0037] 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.

[0038] 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.

[0039] Research has found that the main reason for the failure of the pressure relief valve in the related technology is that in order to ensure a fast enough pressure relief speed, the cavity in the side beam is made large enough to ensure exhaust space. However, this will reduce the wall thickness of the side beam, thereby reducing the strength of the side beam and making it prone to deformation or breakage.

[0040] To address the aforementioned problems, according to one aspect of this application, a battery pack is provided, such as... Figures 1 to 13As shown, one embodiment of the battery pack includes: a side beam 61, a base plate 62, a battery 70, and a housing pressure relief valve 1. The side beam 61 includes a first wall 611 and a second wall 612 spaced apart along its outer to its inner direction. An exhaust chamber 614 is formed between the first wall 611 and the second wall 612. The first wall 611 is provided with a first through hole 613 communicating with the exhaust chamber 614. In the direction from the inner to the outer side of the side beam 61, the ratio of the wall thickness of the first wall 611 to the maximum width of the exhaust chamber 614 is a ratio E. The pressure relief valve 1 includes a body 10, a movable rod 31 movably mounted on the body 10, and a cover plate 32 fixedly connected to the movable rod 31. The body 10 is fixedly mounted on the outside of the first wall 611. The body 10 is provided with a first connecting hole 11 communicating with the first through hole 613 and a second connecting hole 12 coaxial with and communicating with the first connecting hole 11. The diameter of the second connecting hole 12 is larger than the diameter of the first connecting hole 11. The movable rod 31 passes through the first connecting hole 11. When the movable rod 31 moves, the cover plate 32 can open or close the first connecting hole 11. When the cover plate 32 closes the first connecting hole 11, at least part of the cover plate 32 is located in the second connecting hole 12. Specifically, when the cover plate 32 is at its furthest position with the first connecting hole 11 open, in the direction from the second wall 612 to the first wall 611, the cover plate 32 is farther away from the second connecting hole 12, and the minimum distance between the side of the cover plate 32 facing the second connecting hole 12 and the first hole wall 121 of the second connecting hole 12 is a distance B mm. The ratio E, the distance B mm, and the diameter R mm of the first through hole 613 satisfy the following condition: 0.57 10 -4 ≤E / (B R)≤11.08 10 -4 .

[0041] Applying the technical solution of this application, when the pressure relief valve 1 of the housing does not reach the preset pressure, the cover plate 32 closes the first connecting hole 11 to prevent the battery pack's medium from leaking or being contaminated by the outside, thus ensuring the normal operation of the battery pack; when the pressure relief valve 1 of the housing reaches the preset pressure, it pushes the cover plate 32 to move away from the first connecting hole 11, and the cover plate 32 opens the first connecting hole 11 to achieve pressure relief. Wherein, when E / (B R) is less than 0.57 10 -4 When the thickness of the first wall 611 is too small, or the minimum distance between the side of the cover plate 32 facing the second connecting hole 12 and the first hole wall 121 of the second connecting hole 12 and the diameter of the first through hole 613 is too large, the portion of the first wall 611 located at the exhaust chamber 614 becomes too weak, and the strength of the side beam 61 of the box body pressure relief valve 1 is low. The side beam 61 with low strength is prone to deformation or even breakage when subjected to the high impact force and pressure load of the pressure relief gas passing through the exhaust chamber 614. When E / (B R) greater than 11.08 10 -4 If the thickness of the first wall 611 is too large, or if the minimum distance between the side of the cover plate 32 facing the second connecting hole 12 and the first hole wall 121 of the second connecting hole 12 is too small compared to the diameter of the first through hole 613, the portion of the first wall 611 located in the exhaust chamber 614 will occupy a large space, resulting in a smaller pressure relief space for the pressure relief valve 1 of the housing. This increases the resistance of the pressure relief gas passing through the exhaust chamber 614, leading to a slower pressure relief rate in the battery pack. Consequently, the internal temperature and pressure of the battery pack will be higher, easily triggering a chain reaction of thermal runaway risks. Thus, E / (B R) controlled at 0.57 10 -4 Up to 11.08 10 -4 Within a certain range, the portion of the first wall 611 located at the exhaust chamber 614 is prevented from being too thin, and the wall thickness of the first wall 611 is also prevented from being too large. Furthermore, the size of the internal pressure relief space of the battery pack is reasonably controlled, i.e., the resistance of the pressure-relieved gas passing through the exhaust chamber 614 is reasonably controlled. While ensuring timely pressure relief of the battery pack, the strength of the side beam 61 where the pressure relief valve 1 is installed is guaranteed, reducing the possibility of deformation and preventing internal and external conduction of the battery pack, which would affect the safety of battery pack use. Therefore, the technical solution of this application effectively solves the problem of deformation of the side beam where the pressure relief valve is installed in the related art.

[0042] It should be noted that "the first hole wall 121 of the second connecting hole 12" refers to the surface of the hole wall of the second connecting hole 12 that forms a circle.

[0043] It should be noted that the term " " indicates a multiplication sign.

[0044] The above E / (B R can be 0.57 10 -4 0.6 10 -4 0.8 10 -4 1.0 10 -4 1.2 10 -4 1.4 10 -4 1.6 10 -4 1.8 10 -4 2.0 10 -4 2.2 10 -4 、2.4 10 -4 、2.6 10 -4 、2.8 10 -4 、3.0 10 -4 、3.2 10 -4 、3.4 10 -4 、3.6 10 -4 、3.8 10 -4 、4.0 10 -4 、4.2 10 -4 、4.4 10 -4 、4.6 10 -4 、4.8 10 -4 、5.0 10 -4 、5.2 10 -4 、5.4 10 -4 、5.6 10 -4 、5.8 10 -4 、6.0 10 -4 、6.2 10 -4 、6.4 10 -4 、6.6 10 -4 、6.8 10 -4 、7.0 10 -4 、7.2 10 -4 、7.4 10 -4 、7.6 10 -4 、7.8 10 -4 、8.0 10 -4 、8.2 10 -4 、8.4 10-4 8.6 10 -4 8.8 10 -4 9.0 10 -4 9.2 10 -4 9.4 10 -4 9.6 10 -4 9.8 10 -4 10.0 10 -4 10.2 10 -4 10.4 10 -4 10.6 10 -4 10.8 10 -4 11.0 10 -4 11.08 10 -4 It can be any value in the range or a value between any two values.

[0045] The wall thickness of the first wall 611 is greater than or equal to 1.5 mm and less than or equal to 3 mm, and the maximum width of the exhaust cavity 614 is greater than or equal to 15 mm and less than or equal to 30 mm. Preferably, the wall thickness of the first wall 611 is any one of 1.5 mm, 2 mm, 2.5 mm, or 3 mm, or a value between any two of these values. The maximum width of the exhaust cavity 614 is any one of 15 mm, 20 mm, 25 mm, or 30 mm, or a value between any two of these values.

[0046] The study found that the minimum distance between the side of the cover plate 32 facing the second connecting hole 12 and the first hole wall 121 of the second connecting hole 12 is too small, resulting in insufficient pressure relief space for the pressure relief valve 1 of the housing, leading to untimely pressure relief; the minimum distance between the side of the cover plate 32 facing the second connecting hole 12 and the first hole wall 121 of the second connecting hole 12 is too large, resulting in an excessively fast exhaust rate, affecting the strength of the side beam. The ratio of the wall thickness of the first wall 611 to the maximum width of the exhaust chamber 614 is too small, resulting in poor strength of the side beam and easy deformation of the side beam; the ratio of the wall thickness of the first wall 611 to the maximum width of the exhaust chamber 614 is too large, resulting in insufficient air guiding space within the side beam, leading to a slow pressure relief rate. The diameter Rmm of the first through hole 613 is too small, resulting in insufficient pressure relief space for the pressure relief valve 1 of the housing, leading to untimely pressure relief; the diameter Rmm of the first through hole 613 is too large, resulting in poor strength of the side beam and easy deformation of the side beam.

[0047] The aforementioned pressure relief space refers to the annular space between the side of the cover plate 32 facing the second connecting hole 12 and the first hole wall 121 of the second connecting hole 12 when the cover plate 32 opens the first connecting hole 11 to achieve pressure relief.

[0048] The aforementioned air guiding space within the side beam refers to the air guiding channel provided within the side beam. When the battery pack experiences thermal runaway, it will generate depressurized gas. This air guiding channel can guide the depressurized gas within the battery pack into the exhaust chamber 614.

[0049] The aforementioned edge beam can be formed by splicing multiple beams together. Each edge beam includes four sub-edge beams, which connect 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 edge beam can be made of various materials, such as aluminum alloy, copper alloy, steel, or plastic. The edge beam can be rectangular, circular, polygonal, etc., with no specific limitation. The edge beam contains an internal cavity.

[0050] The aforementioned pressure relief valve is a component that is activated to release internal pressure or temperature when the internal pressure or temperature of the battery pack reaches a predetermined threshold. The pressure relief valve 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 pressure relief valve seals the battery casing to ensure normal battery operation; in the event of thermal runaway, the pressure relief valve needs to activate its explosion-proof function in a timely manner to release internal gas and heat, thereby reducing the risk of explosion. The working principle of the pressure relief 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 pressure relief valve may include a housing, a valve cover, and a hinge structure. The pressure relief valve can be made of metal or flame-retardant polymer materials such as polyvinyl chloride, polyvinylidene chloride, and fluoroplastics.

[0051] like Figures 4 to 13 As shown, the battery pack also includes a telescopic member 33, which is disposed between the moving rod 31 and the body 10. The moving rod 31 is slidably connected to the body 10. The two ends of the telescopic member 33 abut against the moving rod 31 and the body 10 respectively. When the cover plate 32 is in the position of opening the first through hole 613, the telescopic member 33 causes the cover plate 32 to reset from the position of opening the first through hole 613 to the position of closing the first through hole 613. When the internal pressure of the battery pack increases, a pressure-relieving gas is generated. When the cover plate 32 is pushed by the pressure-relieving gas and overcomes the resistance of the telescopic member 33, the moving rod 31 moves away from the body 10 along the axis C of the first through hole 613 to open the first through hole 613 for pressure relief. At this time, the telescopic member 33 is compressed or stretched to store energy. When the pressure of the pressure-relieving gas drops to a level that cannot overcome the compression or stretching of the telescopic member 33 to store energy, the telescopic member 33 releases the stored energy, which directly acts on the moving rod 31, causing the cover plate 32 to move back from the position where the first through hole 613 is opened to the position where the first through hole 613 is closed. This resets the cover plate 32 to the position where the first through hole 613 is closed, thereby achieving automatic sealing after pressure relief. This effectively prevents external contaminants from entering the battery pack in a non-thermal runaway state, improving the sealing reliability and safety of the battery pack.

[0052] The aforementioned telescopic component 33 includes a spring, disc spring, leaf spring, rubber pad, or elastic ring. For ease of processing and lower cost, the telescopic component 33 of this application is preferably a compression spring.

[0053] like Figures 5 to 13 As shown, the movable rod 31 is preferably a push rod connected to the cover plate 32 and a stop ring disposed on the push rod. The stop ring is located at the end of the push rod away from the cover plate 32, and the two ends of the telescopic member 33 abut against the bridging part 20 and the stop ring, respectively. When the telescopic member 33 always applies a spring force to the stop ring, and there is no depressurized gas pushing the cover plate 32, the push rod always pulls the cover plate 32 under the action of the spring force of the telescopic member 33, and the cover plate 32 can always maintain a stop engagement with the stop surface 13, so that the cover plate 32 is stably held in the position of closing the first connecting hole 11. When there is depressurized gas pushing the cover plate 32, the depressurized gas overcomes the spring force applied by the telescopic member 33 to the stop ring. At this time, the telescopic member 33 is compressed and stores force, and the cover plate 32 drives the push rod to move, and the cover plate 32 opens the first connecting hole 11. When the cover plate 32 loses the pressure relief gas, it cannot overcome the spring force of the telescopic member 33. Under the action of the spring force accumulated in the telescopic member 33, the stop ring is pulled by the push rod to move the cover plate 32. The cover plate 32 is reset from the position of opening the first connecting hole 11 to the position of closing the first connecting hole 11 to prevent foreign objects from entering the first connecting hole 11.

[0054] like Figures 4 to 9As shown, the movable rod 31 extends into the exhaust chamber 614. In the direction of axis C of the first through hole 613, the distance the movable rod 31 extends into the exhaust chamber 614 is less than or equal to the width of the exhaust chamber 614. This distance range effectively limits the space occupied by the movable rod 31 within the exhaust chamber 614, ensuring that during the opening of the pressure relief valve, the depressurized gas can still flow smoothly and rapidly from the inside of the side beam 61 through the first through hole 613 to the first connecting hole 11 and the second connecting hole 12, avoiding partial blockage of the airflow channel due to excessive length of the movable rod 31. This significantly improves the pressure relief response speed and gas emission rate. Simultaneously, this distance range is adapted to the displacement distance of the cover plate 32 away from the second connecting hole 12 when open, keeping the exhaust chamber 614 unobstructed during gas release and effectively mitigating the possibility of structural stress concentration in the side beam 61 due to concentrated pressure relief.

[0055] like Figures 4 to 13 As shown, in the axial direction C of the first through hole 613, the distance between the end face of the moving rod 31 facing the second wall 612 and the second wall 612 is greater than or equal to 0.5 mm and less than or equal to 10 mm. This distance range prevents the cover plate 32 from opening too small due to a distance greater than 10 mm, and prevents insufficient exhaust space due to a distance less than 0.5 mm. Thus, the aforementioned distance range is effectively controlled, ensuring that the depressurized gas smoothly exits from the exhaust chamber 614 through the first through hole 613 and the first connecting hole 11, improving the timeliness of the depressurization response and the reasonable depressurization rate, and effectively mitigating the risk of deformation or breakage of the side beam 61 due to a sudden increase in local pressure.

[0056] The preferred distance between the end face of the movable rod 31 facing the second wall 612 and the second wall 612 is 0.5mm, 0.7mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2.1mm, 2.3mm, 2.5mm, 2.7mm, 2.9mm, 3.1mm, 3.3mm, 3.5mm, 3.7mm, 3.9mm, 4.1mm, 4.3mm, 4.5mm, 4.7mm, 4.9mm. The value is any one of 5.1mm, 5.3mm, 5.5mm, 5.7mm, 5.9mm, 6.1mm, 6.3mm, 6.5mm, 6.7mm, 6.9mm, 7.1mm, 7.3mm, 7.5mm, 7.7mm, 7.9mm, 8.1mm, 8.3mm, 8.5mm, 8.7mm, 8.9mm, 9.1mm, 9.3mm, 9.5mm, 9.7mm, 9.9mm, or 10mm, or a value between any two of these values.

[0057] like Figures 4 to 13As shown, the main body 10 includes an annular portion 101 and a bridging portion 20 disposed within the annular portion 101. The annular portion 101 is fixedly disposed on the outer side of the first wall 611. The inner hole of the annular portion 101 forms a first connecting hole 11 and a second connecting hole 12. The movable rod 31 is movably inserted through the bridging portion 20. A groove 22 is provided on the side of the bridging portion 20 away from the cover plate 32. When the internal pressure of the battery pack increases, causing the depressurized gas to impact the movable rod, the movable rod is displaced along the axial direction of the first connecting hole 11 to open the first connecting hole for depressurization. At this time, the groove provides a buffer space for the local deformation caused by the force process during the movement of the movable rod, effectively dispersing the stress concentration caused by the impact of the depressurized gas, and preventing the movable rod from undergoing plastic deformation or breakage due to stress concentration.

[0058] like Figures 4 to 16 As shown, the groove 22 is a trapezoidal groove 22. When the pressure relief gas impact causes the moving rod 31 to deform, the trapezoidal groove 22 can provide support along the axial direction of the moving rod 31, so that the local stress acting on the bridging part 20 is evenly diffused along the shape of the trapezoidal groove 22. This effectively avoids the fracture or plastic deformation of the bridging part 20 caused by stress concentration in the rectangular groove of the prior art, and significantly improves the structural integrity and reliability of the bridging part 20 under pressure relief conditions.

[0059] like Figures 5 to 13 As shown, the main body 10 is fixedly disposed on the outside of the first wall 611 by the first sealing member 50. The first sealing member 50 is located on the outside of the first through hole 613, and the distance between the first sealing member 50 and the second hole wall surface 6131 of the first through hole 613 is greater than 0 mm. The above structural design separates the sealing position of the first sealing member 50 from the second hole wall surface 6131 of the first through hole 613. When the side beam 61 is subjected to internal air pressure or external load, causing local deformation of the first wall 611, the deformation is concentrated on the second hole wall surface 6131 of the first through hole 613. Since the first sealing member 50 does not contact the second hole wall surface 6131 of the first through hole 613, the sealing performance of the first sealing member 50 is not affected by deformation, thereby ensuring stable and reliable airtightness between the main body 10 and the first wall 611, and effectively preventing gas leakage in the first through hole 613 or external contaminants from entering the first through hole 613.

[0060] It should be noted that the "second hole wall surface of the first through hole 613" mentioned above refers to the surface of the second hole wall of the first through hole 613 that forms a circle.

[0061] The first sealing element 50 mentioned above can be made of rubber-based sealing materials, such as nitrile rubber, hydrogenated nitrile rubber, fluororubber, silicone rubber, acrylate rubber, and EPDM rubber; or engineering plastic sealing materials, such as polytetrafluoroethylene, polyetheretherketone, and polyurethane.

[0062] like Figures 5 to 13As shown, the distance between the first sealing element 50 and the second hole wall of the first through hole 613 is greater than or equal to 0.6 mm and less than or equal to 5 mm. When the distance between the first sealing element 50 and the second hole wall of the first through hole 613 is less than 0.6 mm, the first through hole 613 is too close to the first sealing element, resulting in greater deformation of the first wall and causing the first sealing element to fail. When the distance between the first sealing element 50 and the second hole wall of the first through hole 613 is greater than 5 mm, the overall circumference of the first sealing element is larger, increasing the risk of failure. Thus, limiting the distance to the range of 0.6 mm to 5 mm ensures that the first sealing element 50 maintains a distance from the second hole wall of the first through hole 613 when the side beam 61 undergoes thermal runaway or local deformation due to internal pressure. This effectively isolates the first sealing element 50 from the direct squeezing effect of the deformation of the first wall 611 caused by thermal expansion or stress concentration, effectively ensuring the sealing performance of the first sealing element 50.

[0063] The distance between the first sealing element 50 and the second hole wall of the first through hole 613 is preferably 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, or 2. The value is any one of 7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, or 5.0mm, or a value between any two of these values.

[0064] like Figures 5 to 13 As shown, a receiving groove 14 is provided on the body 10 or the first wall 611, and the receiving groove 14 accommodates the first sealing element 50. The first sealing element 50 is accommodated between the inner wall of the receiving groove 14 and the body 10 or the first wall 611, thereby forming a physical isolation between the first sealing element 50 and the external environment, preventing the first sealing element 50 from being exposed, effectively blocking water vapor and corrosive media from directly contacting the first sealing element 50, and significantly improving the sealing reliability.

[0065] Specifically, the main body 10 is provided with a receiving groove 14. In other embodiments, the first wall 611 is provided with a receiving groove 14.

[0066] like Figures 5 to 13As shown, the cross-sectional area of ​​the first connecting hole 11 is smaller than that of the first through hole 613. During the flow of depressurized gas from the exhaust chamber 614 of the side beam 61 through the first through hole 613 to the body 10 of the pressure relief valve 1, it encounters local resistance at the connection between the first through hole 613 and the first connecting hole 11. This effectively reduces the instantaneous kinetic energy of the gas impact, thereby significantly alleviating the stress concentration at the connection between the first wall 611 and the body 10, and improving the sealing reliability between the body 10 and the first wall 611.

[0067] like Figures 5 to 13 As shown, the body 10 includes an annular portion 101 and a bridging portion 20 disposed within the annular portion 101. The annular portion 101 is fixedly disposed on the outer side of the first wall 611. The inner hole of the annular portion 101 forms a first connecting hole 11 and a second connecting hole 12. The moving rod 31 is movably inserted through the bridging portion 20, which divides the first connecting hole 11 into multiple sub-connecting holes 111. When the internal pressure of the battery pack increases, causing the cover plate 32 to open, the depressurized gas is evenly distributed through the multiple sub-connecting holes 111 and impacts the circumferential surface of the moving rod 31, effectively dispersing the force of the depressurized gas, significantly reducing the local stress concentration of the moving rod 31, and preventing it from bending and deforming due to stress concentration, thereby improving the smoothness of the moving rod's movement. At the same time, the bridging portion 20 supports the annular portion 101, enhancing the structural strength of the body 10, so that the first connecting hole and the second connecting hole can still maintain the stability of their contour shape under the impact of the depressurized gas.

[0068] like Figures 5 to 13 As shown, along the axis C of the first through hole 613, the cover plate 32 includes a first cover surface 321 and a second cover surface 322. The first cover surface 321 is located on the side of the cover plate 32 away from the moving rod 31, and the second cover surface 322 is located on the side of the cover plate 32 facing the moving rod 31. The area of ​​the first cover surface 321 is larger than the area of ​​the second cover surface 322. During the opening process, after the depressurized gas enters the second through hole 12 through the first through hole 11, it can push the cover plate 32 circumferentially along the second cover surface 322, allowing the cover plate 32 to open more quickly. Furthermore, because the area of ​​the first cover surface 321 is larger than the area of ​​the second cover surface 322, a larger flow cross-section can be formed, facilitating the axial diffusion of the depressurized gas and reducing the local pressure accumulation of the depressurized gas in the second through hole 12. This makes the depressurization process more uniform and efficient, thereby reducing the local impact stress of the first wall 611 and ensuring the structural strength of the side beam 61.

[0069] like Figures 5 to 13As shown, the ratio of the area of ​​the first cover 321 to the area of ​​the second cover 322 is greater than or equal to 1.56 and less than or equal to 2.78. This reasonably increases the minimum distance between the side of the cover 32 facing the second connecting hole 12 and the first hole wall of the second connecting hole 12, further reasonably controlling the size of the internal pressure relief space of the battery pack. While ensuring timely pressure relief of the battery pack, it also ensures the strength of the side beam 61 where the pressure relief valve 1 of the housing is installed, reducing the possibility of deformation and avoiding internal and external conduction of the battery pack, which would affect the safety of battery pack use.

[0070] The ratio of the area of ​​the first cover surface 321 to the area of ​​the second cover surface 322 is preferably any one of 1.56, 1.61, 1.66, 1.71, 1.76, 1.81, 1.86, 1.91, 1.96, 2.01, 2.06, 2.11, 2.16, 2.21, 2.26, 2.31, 2.36, 2.41, 2.46, 2.51, 2.56, 2.61, 2.66, 2.71, 2.76, or 2.78, or a value between any two values.

[0071] like Figures 5 to 13 As shown, a stop surface 13 is formed between the first connecting hole 11 and the second connecting hole 12. The cover plate 32 can stop and cooperate with the stop surface 13. When the cover plate 32 stops and cooperates with the stop surface 13, the cover plate 32 closes the first connecting hole 11. A second sealing element 51 is provided between the cover plate 32 and the stop surface 13. When the cover plate 32 stops and cooperates with the stop surface 13, the second sealing element 51 is deformed by pressure and fits tightly between the two, effectively blocking the leakage path between the first connecting hole 11 and the external environment. This significantly improves the airtight reliability of the housing pressure relief valve 1 under normal pressure or negative pressure conditions and reduces the risk of pressure relief gas leakage or foreign objects entering the first connecting hole 11 due to the failure of the second sealing element 51.

[0072] It should be noted that, in order to facilitate processing and forming, and to facilitate the subsequent installation of the structure, the first connecting hole 11, the stop surface 13 and the second connecting hole 12 together form a stepped hole.

[0073] like Figures 5 to 13As shown, there is a first distance H1mm between the axis C of the first through hole 613 and the top wall of the side beam 61, and a second distance H2mm between the axis C of the first through hole 613 and the bottom wall of the side beam 61. The first distance is greater than or equal to the second distance H2mm. The above-mentioned dimensional limitation makes the position of the first through hole 613 closer to the bottom of the side beam 61. Therefore, when the thermal runaway gas is released outward from the exhaust chamber 614 through the first through hole 613, the gas impact force mainly acts on the bottom of the first wall 611 rather than the top of the first wall 611. This can make full use of the high structural strength brought by the connection between the bottom wall of the side beam 61 and the base plate, and effectively avoid the risk of stress concentration and deformation caused by setting the first through hole at the top of the side beam.

[0074] It should be noted that the battery pack includes a side beam and a base plate set at the bottom of the side beam. The top wall of the side beam 61 refers to the end of the side beam 61 away from the base plate, and the top wall of the side beam 61 refers to the end of the side beam 61 close to the base plate.

[0075] like Figures 5 to 13 As shown, the second distance H2mm is greater than or equal to 8mm and less than or equal to 40mm. This facilitates control over the size of the exhaust chamber. On the one hand, it prevents the second distance H2mm from being too small, which would cause the exhaust chamber to occupy a large internal space of the side beam, resulting in significant deformation of the side beam. On the other hand, it prevents the second distance H2mm from being too large, which would cause the exhaust path of the exhaust chamber to be too long, increasing the pressure relief and exhaust rate, and thus causing a greater impact on the main body 10. In this way, controlling the size range of the second distance H2mm can significantly improve the structural strength of the side beam 61 and the smoothness of exhaust from the exhaust chamber.

[0076] The second distance H2mm mentioned above is preferably any value among 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, or 40mm, or a value between any two values.

[0077] like Figures 5 to 13As shown, the pressure relief valve also includes a mounting cylinder 40 fixedly connected to the first connecting hole 11 and the bridging portion 20. The mounting cylinder 40 is sleeved outside the moving rod 31 and is welded or bonded to the bridging portion 20. This ensures that the mounting cylinder 40 is reliably fixed to the bridging portion 20. Furthermore, the friction and impact loads of the moving rod 31 during reciprocating movement within the first connecting hole 11 are directly borne by the mounting cylinder 40, rather than directly transmitted to the bridging portion 20. This avoids direct contact between the moving rod 31 and the bridging portion 20, thereby reducing the risk of structural failure due to stress concentration in the bridging portion 20 and extending the service life of the pressure relief valve. In this application, a guide shroud 66 is provided on the first wall 611, covering the pressure relief valve. This guide shroud 66 can directionally guide the pressure relief gas ejected from the pressure relief valve, preventing the pressure relief gas from flowing haphazardly and creating a chain reaction risk of thermal runaway.

[0078] According to another aspect of this application, a battery pack is provided, comprising a battery housing assembly, a base plate 62, and a battery 70. The battery housing assembly is the aforementioned battery housing assembly. Since the aforementioned battery housing assembly can solve the problem in related technologies where the side beam with the pressure relief valve is easily deformed, the battery pack including this battery housing assembly can solve the same technical problem. The base plate 62 is disposed at the bottom of the side beam 61 and forms a receiving cavity with the side beam 61, and the battery 70 is disposed within the receiving cavity.

[0079] The aforementioned base plate is the main load-bearing component of the battery pack. It typically refers to the structural component installed at the bottom of the battery pack, used to support and secure the internal battery pack components such as the battery assembly, battery management system, and cooling system. The base plate is located at the bottom of the casing 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; there are no specific limitations, and its dimensions are determined by the number and size of the battery cells housed in the battery pack.

[0080] The aforementioned battery can store chemical energy and controllably convert chemical energy into electrical energy. In recyclable batteries, the active materials can be activated by charging after discharge so that the battery can continue to be used. The battery includes a casing and a cell disposed inside the casing.

[0081] like Figures 1 to 13 As shown, the bottom of the battery 70 has a battery explosion-proof valve 71, which faces the base plate 62. The base plate 62 has a first exhaust channel 72 that connects the battery explosion-proof valve and the exhaust chamber 614. In the event of thermal runaway, the depressurized gas generated inside the battery can break through the battery explosion-proof valve 71, enter the first exhaust channel 72, and flow in a directed manner to the exhaust chamber 614, preventing the depressurized gas from accumulating inside the battery pack.

[0082] 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.

[0083] like Figures 1 to 13 As shown, multiple cavities 63 are spaced apart inside the side beam 61 along the preset direction Z. A partition plate is installed inside the side beam 61, separating adjacent cavities 63. This provides multiple cavities 63 inside the side beam, avoiding the formation of a large deformation area from a single cavity. Furthermore, the partition plate restricts the deformation expansion of the cavities 63 along the preset direction Z of the side beam 61, effectively limiting the local deformation tendency caused by thermal expansion or pressure impact. It also avoids stress concentration on the first wall 611 at the installation position of the pressure relief valve 1, which is caused by a single continuous cavity, significantly improving the structural strength of the side beam 61 where the pressure relief valve 1 is installed.

[0084] It should be noted that the preset direction Z of the side beam 61 can be the height direction, width direction, or length direction of the side beam 61.

[0085] like Figures 1 to 13 As shown, the multiple cavities 63 include a first cavity 63 and a second cavity 63. The first cavity 63 forms an exhaust chamber 614. In the preset direction Z of the side beam 61, the size of the first cavity 63 is larger than the size of the second cavity 63. When the exhaust chamber 614 is subjected to the impact of the depressurized gas inside during thermal runaway, the second cavity 63 can absorb the deformation of the exhaust chamber 614, effectively blocking the overall deformation trend of the exhaust chamber 614 along the preset direction of the side beam 61 under the action of gas pressure. This significantly improves the structural strength of the side beam 61 during the depressurization process, thereby reducing the risk of local deformation or fracture of the first wall due to stress concentration. At the same time, by setting the size of the first cavity 63 to be larger than that of the second cavity 63, it is ensured that the exhaust channel formed by the first cavity 63 has sufficient volume and flow efficiency, balancing the depressurization performance and structural strength.

[0086] like Figures 1 to 13As shown, in the predetermined direction Z of the side beam 61, the first cavity 63 is closer to the bottom plate 62 than the second cavity 63. Thus, since the bottom of the side beam 61 is connected to the bottom plate 62, the placement of the bottom plate 62 increases the structural strength of the bottom of the side beam 61. This allows the larger first cavity 63 to receive support from the stronger side beam 61 at the bottom, reducing the risk of deformation to the side beam 61 caused by the larger first cavity 63.

[0087] like Figures 1 to 13 As shown, the wall thickness of the first wall 611 is greater than or equal to the wall thickness of the second wall 612. In this way, the structural strength of the first wall 611 is higher than or equal to the structural strength of the second wall 612, so that the first wall 611 has a higher resistance to deformation when subjected to the force of the body and the pressure impact in the exhaust cavity, effectively ensuring the stability of the fixed connection between the first wall 611 and the body, and preventing the sealing failure caused by deformation around the first through hole.

[0088] like Figures 1 to 9 As shown, the interior of the side beam 61 is provided with a second exhaust channel connecting the battery and the exhaust chamber 614, and the second wall 612 is provided with a second through hole 65 connecting the second exhaust channel and the exhaust chamber 614. The depressurized gas generated by the battery during thermal runaway can be directionally guided along the second exhaust channel and directly introduced into the exhaust chamber 614 through the second through hole, preventing the depressurized gas from diffusing or accumulating locally around the inside of the side beam, significantly improving the unobstructedness and timeliness of the exhaust path.

[0089] like Figures 1 to 9 As shown, the area enclosed by the first through hole 613 and the area enclosed by the second through hole 65 form a first projection and a second projection respectively on a plane parallel to the first wall 611. The first projection and the second projection do not coincide. During thermal runaway, the depressurized gas introduced into the exhaust chamber 614 through the second through hole 65, and the depressurized gas discharged from the exhaust chamber 614 through the first through hole 613, during the process of passing through the first through hole 613 and the second through hole 65, the stress areas of the depressurized gas acting on the first wall 611 and the second wall 612 are staggered on a plane parallel to the first wall 611, effectively avoiding stress concentration and effectively reducing the risk of deformation or cracking of the side beam 61 under depressurization impact.

[0090] like Figures 1 to 9As shown, a guide plate 64 is provided on the side of the second wall 612 facing the first wall 611. The guide plate 64 is inclined relative to the first wall 611. In the preset direction Z of the side beam 61, the guide plate 64 is located on the side of the second through hole 65 away from the first through hole 613. The depressurized gas entering the exhaust chamber 614 from the second through hole 65 first impacts the inclined surface of the guide plate 64 after entering, and is guided into the exhaust chamber 614 along the guide plate 64. This effectively avoids the depressurized gas directly impacting the area of ​​the first wall 611 around the first through hole 613, significantly reducing stress concentration caused by the impact of the depressurized gas, and reducing the risk of deformation or fracture of the first wall 611 due to excessive local stress.

[0091] like Figures 1 to 9 As shown, the inclination angle of the guide plate 64 relative to the first wall 611 is greater than or equal to 20 degrees and less than or equal to 80 degrees. The depressurized gas entering the exhaust chamber from the second through-hole is stably guided by the inclined surface of the guide plate 64, effectively preventing the depressurized gas from directly impacting the area of ​​the first wall 611 surrounding the first through-hole, significantly reducing local stress concentration in the first wall 611. Thus, by controlling the aforementioned inclination angle within the range of 20 to 80 degrees, the guide plate 64 can work synergistically and complementaryly with the ratio E, the distance Bmm, and the diameter Rmm of the first through-hole. This ensures that the depressurized gas flows efficiently and directionally through the first through-hole to the pressure relief valve of the housing, while minimizing the impact load on the first wall 611, thereby significantly improving the overall structural strength and deformation resistance of the side beam under thermal runaway conditions.

[0092] The tilt angle of the aforementioned guide plate 64 relative to the first wall 611 is preferably any value among 20 degrees, 22 degrees, 24 degrees, 26 degrees, 28 degrees, 30 degrees, 32 degrees, 34 degrees, 36 degrees, 38 degrees, 40 degrees, 42 degrees, 44 degrees, 45 degrees, 46 degrees, 48 ​​degrees, 50 degrees, 52 degrees, 54 degrees, 56 degrees, 58 degrees, 60 degrees, 62 degrees, 64 degrees, 66 degrees, 68 degrees, 70 degrees, 72 degrees, 74 degrees, 76 degrees, 78 degrees, or 80 degrees, or a value between any two values.

[0093] like Figures 1 to 9 As shown, when the ratio E is greater than or equal to 0.05 and less than or equal to 0.2, and the ratio of the wall thickness of the first wall 611 to the maximum width of the exhaust cavity 614 is less than 0.05, the strength of the side beam is poor, and the side beam is prone to significant deformation. When the ratio of the wall thickness of the first wall 611 to the maximum width of the exhaust cavity 614 is greater than 0.2, the air guiding space in the side beam is insufficient, resulting in a slow depressurization rate. Thus, by controlling the ratio E within the range of 0.05 to 0.2, sufficient structural strength of the first wall 611 is ensured, reducing the risk of deformation or breakage of the side beam 61.

[0094] The ratio E is preferably any one of 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0.1, 0.105, 0.11, 0.115, 0.12, 0.125, 0.13, 0.135, 0.14, 0.145, 0.15, 0.155, 0.16, 0.165, 0.17, 0.175, 0.18, 0.185, 0.19, 0.195, or 0.2, or a value between any two values. More preferably, the ratio E is greater than or equal to 0.08 and less than or equal to 0.17. When the above preferred range is met, the strength of the side beam 61 is ensured, while the depressurization rate of the battery pack is further guaranteed.

[0095] The diameter Rmm of the first through hole 613 is greater than or equal to 25mm and less than or equal to 70mm. When the diameter Rmm of the first through hole 613 is less than 25mm, the pressure relief space of the pressure relief valve 1 in the housing is insufficient, resulting in untimely pressure relief. When the diameter Rmm of the first through hole 613 is greater than 70mm, the strength of the side beam is poor, and the side beam is prone to significant deformation. Thus, by controlling the diameter Rmm within the range of 25mm to 70mm, the pressure relief valve 1 in the housing has sufficient pressure relief space, which facilitates timely pressure relief, and the side beam has sufficient structural strength, reducing the possibility of significant deformation of the side beam and effectively reducing the risk of breakage of the side beam 61.

[0096] The diameter Rmm mentioned above is preferably any value among 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm, 51mm, 52mm, 53mm, 54mm, 55mm, 56mm, 57mm, 58mm, 59mm, 60mm, 61mm, 62mm, 63mm, 64mm, 65mm, 66mm, 67mm, 68mm, 69mm, or 70mm, or a value between any two values. More preferably, the diameter Rmm of the first through hole 613 is greater than or equal to 32mm and less than or equal to 60mm. When the above preferred range is met, the battery pack has sufficient pressure relief space and timely pressure relief is ensured, while the impact on the strength of the side beam 61 is further reduced.

[0097] The minimum distance Bmm between the side of the cover plate 32 facing the second connecting hole 12 and the first hole wall 121 of the second connecting hole 12 is greater than or equal to 6mm and less than or equal to 15mm. When the minimum distance Bmm between the side of the cover plate 32 facing the second connecting hole 12 and the first hole wall of the second connecting hole 12 is less than 6mm, the pressure relief space of the box pressure relief valve 1 is insufficient, resulting in untimely pressure relief; when the minimum distance between the side of the cover plate 32 facing the second connecting hole 12 and the first hole wall of the second connecting hole 12 is greater than 15mm, the exhaust rate is too fast, affecting the strength of the side beam.

[0098] The aforementioned distance Bmm is preferably any value selected from 6.0mm, 6.5mm, 7.0mm, 7.5mm, 8.0mm, 8.5mm, 9.0mm, 9.5mm, 10.0mm, 10.5mm, 11.0mm, 11.5mm, 12.0mm, 12.5mm, 13.0mm, 13.5mm, 14.0mm, 14.5mm, or 15.0mm, or a value between any two of these values. More preferably, the distance Bmm is greater than or equal to 7.5mm and less than or equal to 11.8mm. When the above preferred range is met, a better balance can be achieved between the exhaust rate and the strength of the side beam, ensuring the safety of the battery pack.

[0099] Furthermore, the above E / (B) R) controlled at 1.41 10 -4 Up to 8.85 10 -4 Within the specified range, the size of the internal pressure relief space of the battery pack is reasonably controlled, which can relieve pressure in a timely manner. While further ensuring timely pressure relief of the battery pack, the strength of the side beam 61 on which the pressure relief valve 1 of the housing is installed is guaranteed, which greatly reduces the possibility of deformation, reduces the risk of the side beam 61 breaking, and avoids causing internal and external conduction of the battery pack, which would affect the safety of battery pack use.

[0100] The performance of the box-type pressure relief valves on the side beams obtained in Examples 1 to 16 and Comparative Examples 1 to 4 was tested, and the performance is shown in Table 1.

[0101] Table 1

[0102]

[0103] 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 deformation degree of the side beam can be controlled to avoid unqualified situations by reasonably selecting the values ​​of the four parameters. Furthermore, the difference between the opening pressure of the box-type pressure relief valve and the preset pressure can be reasonably controlled, ensuring sufficient pressure relief space and timely pressure relief, thus preventing unqualified situations. Embodiments 4 to 11, in particular, effectively balance the control of the side beam deformation degree and the difference between the opening pressure of the box-type pressure relief valve and the preset pressure.

[0104] By comparing the data from Examples 12, 13, and 15 with Comparative Example 1, it can be seen that when E / (B R) satisfies: 9.81 10 -4 ≤E / (B R)≤11.08 10 -4 At this time, the deformation degree of the side beam is considered good, and the difference between the opening pressure of the box-type pressure relief valve and the preset pressure is considered acceptable. Specifically, when E / (B) R) equals 11.08 10 -4 When E / (B) can be at its maximum value, R) satisfies: 11.08 10 -4 ≤E / (B R)≤12.17 10 -4 At that time, as can be seen from the values ​​of Comparative Example 1, the deformation of the side beam is in good condition, but the difference between the opening pressure of the box body pressure relief valve and the preset pressure is unqualified.

[0105] By comparing the data from Examples 1 to 3 and Comparative Example 2, it can be seen that when E / (B R) satisfies: 0.57 10 -4 ≤E / (B R)≤0.94 10 -4 At that time, the deformation degree of the side beam is acceptable, and the difference between the opening pressure of the box body pressure relief valve and the preset pressure is good. Among them, E / (B) in Example 1 is acceptable. R can be designed to have a minimum value of 0.57. 10 -4 When E / (B R) satisfies: 0.54 10 -4 ≤E / (B R) < 0.57 10 -4At that time, as can be seen from the values ​​of Comparative Example 2, although the deformation of the side beam has become unqualified, the difference between the opening pressure of the box body pressure relief valve and the preset pressure is still in good condition.

[0106] By comparing the data from Examples 12, 13, and 15 with Comparative Example 3, it can be seen that when E / (B R) satisfies: 9.81 10 -4 ≤E / (B R)≤11.08 10 -4 When the side beam deformation is good, and the difference between the opening pressure of the box body pressure relief valve and the preset pressure is acceptable, Rmm can be set to a minimum value of 22mm; when E / (B R) satisfies: 11.08 10 -4 <E / (B R)≤13.09 10 -4 At that time, as can be seen from the values ​​of Comparative Example 3, the deformation of the side beam is in good condition, but the difference between the opening pressure of the box body pressure relief valve and the preset pressure is unqualified.

[0107] By comparing the data from Example 1, Example 14, Example 16, and Comparative Example 4, it can be seen that when E / (B R) satisfies: 0.57 10 -4 ≤E / (B R)≤1.01 10 -4 When the deformation of the side beam is within acceptable limits, and the difference between the opening pressure of the box-type pressure relief valve and the preset pressure is within acceptable limits, the minimum value of E can be designed to be 0.04 mm, and the maximum value of B mm can be designed to be 17.2 mm; when E / (B R) satisfies: 0.51 10 -4 ≤E / (B R) < 0.57 10 -4 At that time, as can be seen from the values ​​of Comparative Example 4, although the deformation of the side beam has become unqualified, the difference between the opening pressure of the box body pressure relief valve and the preset pressure is still in good condition.

[0108] It should be noted that the dimensions of the battery pack in this application can be measured using measuring instruments such as micrometers or calipers, including 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.

[0109] The method for measuring the wall thickness of the first wall 611 and the maximum width of the exhaust cavity 614 is as follows: cut the side beam along a plane perpendicular to the extension direction of the side beam, and measure the wall thickness of the first wall 611 and the maximum width of the exhaust cavity 614 on the cross section.

[0110] The test process for the deformation degree of the side beam of the battery pack is as follows:

[0111] Prepare two hundred batteries and stack them within the cavity formed by the side beams and base plate of the battery pack, then bond them securely to the base plate. Select the first side beam on one side of the battery pack as the test object, and install a pressure relief valve on the first side beam corresponding to those in the embodiments and comparative examples. Figure 17 As shown, a first reference line G1 parallel to the extension direction of the first side beam is drawn at the center of the first wall 611 of the first side beam in the height direction. The two ends of the first reference line G1 are used as the first reference point and the second reference point. The distance between the center G0 of the first through hole 613 and the first reference line G1 in the height direction of the battery pack is measured and recorded as L1.

[0112] After covering the battery pack with its lid, install the battery pack on the vibration table according to GB / T2423.43. The testing process should be conducted according to GB / T2423.56. Apply random and fixed-frequency vibration loads in each direction, preferably in the following order: random z-axis, fixed-frequency z-axis, random y-axis, fixed-frequency y-axis, random x-axis, fixed-frequency x-axis (the line connecting the front and rear of the battery pack is the x-axis direction, and the horizontal direction perpendicular to the x-axis is the y-axis direction). The vibration frequency, power spectral density (PSD), vibration time, etc., are shown in Table 2 below.

[0113] Table 2

[0114]

[0115] After the vibration ends, such as Figure 18 As shown, with the first reference point and the second reference point as endpoints, draw a straight line with a marker as the second reference line G2. Measure the distance between the center G0 of the first through hole 613 and the second reference line G2 again, and record it as L2.

[0116] When |L1-L2| is greater than 5mm, the deformation degree of the edge beam is recorded as unqualified; when |L1-L2| is less than or equal to 5mm but greater than 2mm, the deformation degree of the edge beam is recorded as qualified; when |L1-L2| is less than or equal to 2mm, the deformation degree of the edge beam is recorded as good.

[0117] The test procedure for the difference between the opening pressure of the battery pack's pressure relief valve and the preset pressure is as follows:

[0118] Fabricate a pressure relief valve corresponding to the embodiments and comparative examples, and seal and fix the pressure relief valve to the sealing test chamber. The cover plate of the pressure relief valve faces the outside of the sealing test chamber, and the first connecting hole 11 faces the inside of the sealing test chamber. A pressure sensor is installed inside the sealing chamber to collect the gas pressure inside the sealing chamber in real time.

[0119] At room temperature (20℃), use clean, dry compressed air or nitrogen to pressurize the inside of the sealed chamber. The pressurization rate is controlled to be ≤10kPa / s. Record the pressure-time curve in real time until the chamber's pressure relief valve opens. The maximum pressure inside the chamber recorded in the pressure-time curve is taken as the preset opening pressure V1 of the chamber's pressure relief valve.

[0120] Prepare two hundred batteries and stack them within the cavity formed by the side beams and base plate of the battery pack, then bond them to the base plate. Select the first side beam on one side of the battery pack as the test object, and install a pressure relief valve on the first side beam corresponding to those in the embodiments and comparative examples. Electrically connect the battery terminals via conductive strips, and place a heating element on the large side of the casing of one battery at the same location. Install a pressure sensor inside the battery pack to record the pressure-time curve in real time. Seal the battery pack with the lid.

[0121] At room temperature (20℃), 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. The pressure relief valve of the battery pack is observed until it opens. The maximum pressure inside the pack recorded in the pressure-time curve is taken as the actual opening pressure V2 of the pressure relief valve.

[0122] When V2-V1 is greater than 2 kPa, it is recorded as unqualified; when V2-V1 is less than or equal to 2 kPa but greater than 1 kPa, it is recorded as qualified; when V2-V1 is less than or equal to 1 kPa, it is recorded as good.

[0123] 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.

[0124] The positive electrode active material used in this test was selected from LiNi. 0.6 Co 0.2 Mn 0.2Taking 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.

[0125] 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 side beams 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 includes a lower battery housing composed of side beams and 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.

[0126] Battery pack fabrication: The battery pack casing is manufactured, consisting of a base plate, frame, and 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.

[0127] 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 deformation of the side beam where the pressure relief valve of the housing is located in the related art, 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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 battery housing assembly, characterized in that, include: Side beam (61), the side beam (61) includes a first wall (611) and a second wall (612) spaced apart along its outer to its inner direction, an exhaust cavity (614) is formed between the first wall (611) and the second wall (612), the first wall (611) is provided with a first through hole (613) communicating with the exhaust cavity (614), and the ratio of the wall thickness of the first wall (611) to the maximum width of the exhaust cavity (614) in the direction from the inner to the outer of the side beam (61) is ratio E; The box-type pressure relief valve (1) includes a body (10), a movable rod (31) movably disposed on the body (10), and a cover plate (32) fixedly connected to the movable rod (31). The body (10) is fixedly disposed on the outside of the first wall (611). The body (10) is provided with a first connecting hole (11) communicating with the first through hole (613) and a second connecting hole (12) coaxial with and communicating with the first connecting hole (11). The diameter of the second connecting hole (12) is larger than the diameter of the first connecting hole (11). The movable rod (31) passes through the first connecting hole (11). When the movable rod (31) moves, the cover plate (32) can open or close the first connecting hole (11). When the cover plate (32) closes the first connecting hole (11), at least part of the cover plate (32) is located in the second connecting hole (12). When the cover plate (32) is at its furthest position with the first through hole (11) open, in the direction from the second wall (612) to the first wall (611), the cover plate (32) is far away from the second through hole (12), and the minimum distance between the side of the cover plate (32) facing the second through hole (122) and the first hole wall (121) of the second through hole (12) is a distance B mm. The ratio E, the distance B mm, and the diameter R mm of the first through hole (613) satisfy the following: 0.57 10 -4 ≤E / (B R)≤11.08 10 -4 .

2. The battery housing assembly according to claim 1, characterized in that, The battery housing assembly also includes a telescopic member (33), which is disposed between the moving rod (31) and the body (10). The moving rod (31) is slidably connected to the body (10). The two ends of the telescopic member (33) abut against the moving rod (31) and the body (10) respectively. When the cover plate (32) is in the position of opening the first through hole (613), the telescopic member (33) causes the cover plate (32) to reset from the position of opening the first through hole (613) to the position of closing the first through hole (613).

3. The battery housing assembly according to claim 1, characterized in that, The movable rod (31) extends into the exhaust chamber (614), and in the direction of the axis (C) of the first through hole (613), the distance by which the movable rod (31) extends into the exhaust chamber (614) is less than or equal to the width of the exhaust chamber (614).

4. The battery housing assembly according to claim 3, characterized in that, In the axial (C) direction of the first through hole (613), the distance between the end face of the moving rod (31) facing the second wall (612) and the second wall (612) is greater than or equal to 0.5 mm and less than or equal to 10 mm.

5. The battery housing assembly according to claim 1, characterized in that, The body (10) includes an annular portion (101) and a bridging portion (20) disposed within the annular portion (101). The annular portion (101) is fixedly disposed on the outside of the first wall (611). The inner hole of the annular portion (101) forms the first connecting hole (11) and the second connecting hole (12). The moving rod (31) is movably inserted through the bridging portion (20). The bridging portion (20) has a groove (22) on the side away from the cover plate (32).

6. The battery housing assembly according to claim 5, characterized in that, The groove (22) is a trapezoidal groove (22).

7. The battery housing assembly according to any one of claims 1 to 6, characterized in that, The main body (10) is fixedly disposed on the outside of the first wall (611) by a first sealing member (50). The first sealing member (50) is located on the outside of the first through hole (613). The distance between the first sealing member (50) and the second hole wall (6131) of the first through hole (613) is greater than 0 mm.

8. The battery housing assembly according to claim 7, characterized in that, The distance between the first seal (50) and the second hole wall of the first through hole (613) is greater than or equal to 0.6 mm and less than or equal to 5 mm.

9. The battery housing assembly according to claim 7, characterized in that, The body (10) or the first wall (611) is provided with a receiving groove (14) which receives the first sealing element (50).

10. The battery housing assembly according to any one of claims 1 to 6, characterized in that, The cross-sectional area of ​​the first connecting hole (11) is smaller than the cross-sectional area of ​​the first through hole (613).

11. The battery housing assembly according to any one of claims 1 to 6, characterized in that, The body (10) includes an annular portion (101) and a bridging portion (20) disposed within the annular portion (101). The annular portion (101) is fixedly disposed on the outside of the first wall (611). The inner hole of the annular portion (101) forms the first connecting hole (11) and the second connecting hole (12). The moving rod (31) is movably inserted through the bridging portion (20). The bridging portion (20) divides the first connecting hole (11) into a plurality of sub-connecting holes (111).

12. The battery housing assembly according to any one of claims 1 to 6, characterized in that, In the axial (C) direction of the first through hole (613), the cover plate (32) includes a first cover surface (321) and a second cover surface (322). The first cover surface (321) is located on the side of the cover plate (32) away from the moving rod (31), and the second cover surface (322) is located on the side of the cover plate (32) facing the moving rod (31). The area of ​​the first cover surface (321) is larger than the area of ​​the second cover surface (322).

13. The battery housing assembly according to claim 12, characterized in that, The ratio of the area of ​​the first cover (321) to the area of ​​the second cover (322) is greater than or equal to 1.56 and less than or equal to 2.

78.

14. The battery housing assembly according to any one of claims 1 to 6, characterized in that, A stop surface (13) is formed between the first connecting hole (11) and the second connecting hole (12). The cover plate (32) can stop and cooperate with the stop surface (13). A second sealing element (51) is provided between the cover plate (32) and the stop surface (13).

15. The battery housing assembly according to any one of claims 1 to 6, characterized in that, The axis (C) of the first through hole (613) has a first distance H1mm between it and the top wall of the side beam (61), and the axis (C) of the first through hole (613) has a second distance H2mm between it and the bottom wall of the side beam (61). The first distance is greater than or equal to the second distance H2mm.

16. The battery housing assembly according to claim 15, characterized in that, The second distance H2mm is greater than or equal to 8mm and less than or equal to 40mm.

17. A battery pack comprising a battery housing assembly, a base plate (62), and a battery (70), characterized in that, The battery housing assembly is the battery housing assembly according to any one of claims 1 to 16, the bottom plate (62) is disposed at the bottom of the side beam (61) and forms a receiving cavity with the side beam (61), and the battery (70) is disposed in the receiving cavity.

18. The battery pack according to claim 17, characterized in that, The bottom of the battery (70) has a battery explosion-proof valve (71) facing the base plate (62), and the interior of the base plate (62) is provided with a first exhaust channel (72) that connects the battery explosion-proof valve and the exhaust chamber (614).

19. The battery pack according to claim 17, characterized in that, In the preset direction Z of the side beam (61), a plurality of cavities (63) are provided at intervals inside the side beam (61), and a partition plate is provided inside the side beam (61), and two adjacent cavities (63) are separated by the partition plate.

20. The battery pack according to claim 19, characterized in that, The plurality of cavities (63) include a first cavity (63) and a second cavity (63), the first cavity (63) forming the exhaust cavity (614), and in the preset direction Z of the side beam (61), the size of the first cavity (63) is larger than the size of the second cavity (63).

21. The battery pack according to claim 20, characterized in that, In the predetermined direction Z of the side beam (61), the first cavity (63) is closer to the bottom plate (62) than the second cavity (63).

22. The battery pack according to claim 17, characterized in that, The thickness of the first wall (611) is greater than or equal to the thickness of the second wall (612).

23. The battery pack according to claim 17, characterized in that, The side beam (61) is provided with a second exhaust channel connecting the battery and the exhaust chamber (614), and the second wall (612) is provided with a second through hole (65) connecting the second exhaust channel and the exhaust chamber (614).

24. The battery pack according to claim 23, characterized in that, The area enclosed by the first through hole (613) and the area enclosed by the second through hole (65) form a first projection and a second projection respectively on a plane parallel to the first wall (611), and the first projection and the second projection do not coincide.

25. The battery pack according to claim 23, characterized in that, A guide plate (64) is provided on the side of the second wall (612) facing the first wall (611). The guide plate (64) is inclined relative to the first wall (611). In the preset direction Z of the side beam (61), the guide plate (64) is located on the side of the second through hole (65) away from the first through hole (613).

26. The battery pack according to claim 25, characterized in that, The angle of inclination of the guide plate (64) relative to the first wall (611) is greater than or equal to 20 degrees and less than or equal to 80 degrees.

27. The battery pack according to claim 17, characterized in that, The ratio E is greater than or equal to 0.05 and less than or equal to 0.2, and / or the distance B mm is greater than or equal to 25 mm and less than or equal to 70 mm, and / or the diameter R mm of the first through hole (613) is greater than or equal to 6 mm and less than or equal to 15 mm.

28. An electrical device comprising a battery pack, characterized in that, The battery pack is the battery pack according to any one of claims 17 to 27.

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