Lithium ion battery box pressure relief device

Abstract

The invention discloses a lithium ion battery box pressure relief device which comprises a pressure relief valve, the pressure relief valve comprises a valve seat and a valve rod, a hole shaped like a Chinese character'ri 'is formed in one side of the valve seat, a piston cover plate is arranged on the other side of the valve seat, the piston cover plate and the valve seat form an inner cavity, the inner cavity is communicated with the hole shaped like the Chinese character'ri', and one end of the valve rod slidably penetrates through the hole shaped like the Chinese character'ri 'of the valve seat to be fixedly connected with the piston cover plate. A spring is arranged on the valve rod, a fixed spring cover is arranged at the other end of the valve rod, and the spring cover covers the spring. The invention has the following advantages: when the internal battery core of the lithium ion battery pack in the battery box is out of control due to heating and is on fire, and the internal air pressure of the battery box continuously rises and exceeds the set standard air pressure, the air pressure acts on the piston cover plate through the hole shaped like the Chinese character'ri 'and then overcomes the spring to push the piston cover plate out of the valve seat, and meanwhile, the valve rod moves outwards and the spring cover further compresses the spring; and the inner cavity is opened, so that the air pressure leaks outwards. Explosion caused by internal fire and air pressure rise of the battery box is prevented, and explosive casualties and property and economic losses are avoided.

Description

Technical Field

[0001] This invention relates to the technical field of pressure relief devices for lithium-ion battery boxes, specifically to a pressure relief device for lithium-ion battery boxes. Background Technology

[0002] my country has 380 million electric bicycles, making it the world's largest carrier of green transportation. In the first half of 2025, sales of electric two-wheelers reached 32.325 million units, a year-on-year increase of 29.5%.

[0003] However, due to the use of high-energy-density lithium-ion batteries in electric bicycles, fires occur frequently. According to statistics from the National Fire and Rescue Administration, over 19,000 electric bicycle fires were reported in 2024, with 9,175 occurring nationwide from May to December 2024, resulting in multiple deaths and injuries. Compared to other types of fires, electric bicycle fires develop rapidly and have a high fatality and injury rate. Because lithium-ion batteries are installed in sealed enclosures, a rapid increase in pressure within the enclosure when the battery overheats and catches fire can lead to an explosion. Therefore, there is an urgent need to develop pressure relief devices for lithium-ion battery enclosures to prevent explosions and avoid personal injury and property damage from fires. Summary of the Invention

[0004] The purpose of this invention is to provide a pressure relief device for lithium-ion battery boxes to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solutions: This invention discloses a pressure relief device for a lithium-ion battery box, comprising a pressure relief valve, the pressure relief valve including a valve seat and a valve stem, the valve seat having a H-shaped hole on one side and a piston cover plate on the other side, the piston cover plate and the valve seat forming an inner cavity, the inner cavity communicating with the H-shaped hole, one end of the valve stem slidingly passing through the H-shaped hole side of the valve seat and fixedly connected to the piston cover plate, the valve stem having a spring, and the other end of the valve stem having a fixed spring cover covering the spring.

[0006] As an improvement, a gasket is provided in the inner cavity, and the gasket is press-fitted with the inner side of the piston cover plate.

[0007] As an improvement, the valve stem is provided with a threaded nut at the end away from the valve seat, which can secure the spring cover.

[0008] As an improvement, the valve stem slides through the middle of the central plate of the H-shaped hole and is fixedly connected to the piston cover plate.

[0009] As an improvement, the valve seat is provided with several screw holes on the H-shaped hole side. The screw holes are used to fix the pressure relief valve in the battery box by bolts. The opening of the battery box is connected to the H-shaped hole.

[0010] The advantages of this invention compared to existing technologies are as follows: When the internal cells of the lithium-ion battery pack inside the battery box overheat and ignite uncontrollably, if the fire is not extinguished in time, the internal gas pressure of the battery box continuously rises. This pressure acts on the piston cover plate through the H-shaped orifice, then overcomes the spring and pushes the piston cover plate outward from the valve seat. Simultaneously, the valve rod moves outward, and the spring cover further compresses the spring until the inner cavity is opened, thereby releasing the gas pressure. This pressure relief valve can prevent the battery box from exploding due to the increased gas pressure caused by an internal fire, avoiding blast-related personal injury and property damage. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings listed below are only some structural schematic diagrams of the present invention, and not all of them.

[0012] Figure 1 This is a schematic diagram of the structure of a lithium-ion battery box pressure relief device according to the present invention.

[0013] Figure 2 This is a side view of the valve seat of a lithium-ion battery box pressure relief device according to the present invention.

[0014] Figure 3 This is a cross-sectional view of a lithium-ion battery box pressure relief device according to the present invention.

[0015] Figure 4 This is an installation cross-sectional view of a lithium-ion battery box pressure relief device according to the present invention.

[0016] Figure label: Pressure relief valve 1; valve seat 11; H-shaped hole 111; piston cover 112; inner cavity 113; washer 114; screw hole 115; middle plate 116; valve stem 12; spring 121; spring cover 122; nut 123; battery box 2. Detailed Implementation

[0017] 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. 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.

[0018] In the description of the embodiments of the present invention, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on the present invention.

[0019] Furthermore, the terms "first," "second," and "third" are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance. The use of terms such as "horizontal," "vertical," and "suspended" does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be perfectly horizontal, but can be slightly tilted.

[0020] In the description of the embodiments of the present invention, the terms "multiple" or "several" refer to at least two.

[0021] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0022] This embodiment, in conjunction with the accompanying drawings, provides a detailed description of a pressure relief device for a lithium-ion battery box.

[0023] This embodiment provides a pressure relief device for a lithium-ion battery box, such as... Figures 1 to 4 As shown, the device includes a pressure relief valve 1, which comprises a valve seat 11 and a valve stem 12, and is a metal structure. The valve seat 11 has a U-shaped hole 111 on one side and a piston cover plate 112 on the other side. The piston cover plate 112 and the valve seat 11 form an inner cavity 113, which communicates with the U-shaped hole 111. One end of the valve stem 12 slides through the U-shaped hole 111 of the valve seat 11 and is fixedly connected to the piston cover plate 112. A spring 121 is provided on the valve stem 12. Figure 4 In the compressed state, the other end of the valve stem 12 is provided with a fixed spring cover 122. The spring cover 122 is not threaded to the valve stem 12, but is directly put on and the inner end is limited. The spring cover 122 covers the spring 121, and the other end of the spring 121 is limited by the valve seat 11.

[0024] like Figure 3 As shown, a gasket 114 made of rubber is provided in the inner cavity 113 to serve as a seal. The gasket 114 is pressed and fitted with the inner side of the piston cover plate 112.

[0025] like Figure 1 , Figure 4 As shown, the valve stem 12 is provided with a threaded nut 123 at the end away from the valve seat 11. The nut 123 can fasten the spring cover 122 and lock it in place.

[0026] like Figure 1 , Figure 4 As shown, the valve stem 12 slides through the middle part of the middle plate 116 through the H-shaped hole 111 and is fixedly connected to the piston cover plate 112. The middle plate 116 has a round hole in the middle (through which the valve stem 12 slides), and the other end of the spring 121 is limited by the middle plate 116.

[0027] like Figure 4 As shown, the valve seat 11 has several screw holes 115 on the side of the H-shaped hole 111. The screw holes 115 are used to fix the pressure relief valve 1 in the battery box 2 by bolts. The opening of the battery box 2 is connected to the H-shaped hole 111. The valve seat 11 is located outside the battery box 2 and is attached to the wall. It is fixed by bolts. The valve stem 12 is inserted into the battery box 2.

[0028] In specific implementation, in accordance with as follows Figure 4 As shown, the pressure relief valve 1 is installed on the upper side of the battery box 2. Under normal conditions, the piston cover 112, under the action of the spring 121, presses the washer 114 to close the pressure relief valve 1. When the internal cells of the lithium-ion battery pack in the battery box 2 overheat and catch fire, if the fire is not extinguished in time, the internal air pressure of the battery box 2 continues to rise. The air pressure acts on the piston cover 112 through the H-shaped hole 111, and then overcomes the spring 121 to push the piston cover 112 outward out of the valve seat 11. At the same time, the valve stem 12 moves outward, and the spring cover 122 further compresses the spring 121 until the inner cavity 113 is opened, thereby releasing the air pressure. After the air pressure inside the battery box 2 drops, the piston cover 112, under the action of the spring 121, retracts to press the washer 114 to seal the valve seat 11, thereby closing the pressure relief valve 1.

[0029] This pressure relief valve 1 can prevent the battery box 2 from exploding due to increased gas pressure caused by internal fire, thus avoiding blast-related casualties and property damage.

[0030] The present invention and its embodiments have been described above. This description is not restrictive, and the actual scope of protection is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this invention should be included within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A pressure relief device for a lithium-ion battery box, characterized in that, The valve includes a pressure relief valve (1), which includes a valve seat (11) and a valve stem (12). The valve seat (11) has a H-shaped hole (111) on one side and a piston cover plate (112) on the other side. The piston cover plate (112) and the valve seat (11) form an inner cavity (113). The inner cavity (113) communicates with the H-shaped hole (111). One end of the valve stem (12) slides through the H-shaped hole (111) of the valve seat (11) and is fixedly connected to the piston cover plate (112). A spring (121) is provided on the valve stem (12), and a fixed spring cover (122) is provided on the other end of the valve stem (12). The spring cover (122) covers the spring (121).

2. The lithium-ion battery box pressure relief device according to claim 1, characterized in that, A washer (114) is provided in the inner cavity (113), and the washer (114) is pressed against the inner side of the piston cover plate (112).

3. The lithium-ion battery box pressure relief device according to claim 1, characterized in that, The valve stem (12) is provided with a threaded nut (123) at the end away from the valve seat (11), and the nut (123) can fasten the spring cover (122).

4. A lithium-ion battery box pressure relief device according to claim 1, characterized in that, The valve stem (12) slides through the middle part of the middle plate (116) of the H-shaped hole (111) and is fixedly connected to the piston cover plate (112).

5. A lithium-ion battery box pressure relief device according to claim 1, characterized in that, The valve seat (11) has several screw holes (115) on the side of the H-shaped hole (111). The screw holes (115) are used to fix the pressure relief valve (1) in the battery box (2) by bolts. The opening of the battery box (2) is connected to the H-shaped hole (111).

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