Battery box body with fire extinguishing function
By setting up a fusible sealing piece and a distributed air intake design in the battery box, the problem of the lack of effective fire extinguishing measures in the traditional battery box is solved, and the rapid fire extinguishing and safety guarantee of the battery box when it is thermally out of control is achieved.
Patent Information
- Application Number
- CN202411901734.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2025-03-28
AI Technical Summary
Traditional battery boxes lack effective fire extinguishing measures, which leads to the fire spreading easily when the battery gets out of control and causes serious consequences.
A battery box with fire extinguishing function is designed. By melting the conductive sealing member under specific circumstances, the fire extinguishing gas enters the upper cavity for extinguishing the fire, and the diffusion speed of the fire extinguishing gas is improved through a dispersed intake design.
When the battery gets out of control and catches fire, the fire-extinguishing gas can quickly enter the upper cavity, effectively extinguish the flame, ensure the safety of the battery box and peripheral equipment, and improve the fire-extinguishing efficiency.
Smart Images
Figure CN119725943A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of battery boxes, and in particular relates to a battery box with a fire extinguishing function. Background Art
[0002] With the widespread use of new energy equipment such as electric vehicles, battery safety is becoming increasingly important. During the charging and discharging process, the battery may cause thermal runaway due to a variety of reasons, such as internal short circuits and overheating, which may lead to fire and combustion. Traditional battery boxes often only focus on the physical protection of the battery and lack effective fire extinguishing measures. Once the battery catches fire, the fire is easy to spread and cause serious consequences. Therefore, the development of battery boxes with fire extinguishing functions has become an urgent problem to be solved. Summary of the invention
[0003] The purpose of this patent is to provide a battery box with a fire extinguishing function. By setting a sealing member that can melt and conduct the first through hole under specific circumstances, the fire extinguishing gas can enter the upper cavity to extinguish the fire when the battery thermal runaway catches fire, thereby ensuring the safety of the battery box and peripheral equipment. The design of decentralized air intake is realized by utilizing the fact that when some sealing members melt, the remaining sealing members lose air pressure support to greatly increase the diffusion speed of the fire extinguishing gas, thereby ensuring the fire extinguishing efficiency.
[0004] To achieve the above object, a technical solution adopted by the present invention is:
[0005] A battery box with a fire extinguishing function, the battery box having an upper cavity and a lower cavity distributed up and down, the upper cavity being used to assemble batteries, the lower cavity being used to store fire extinguishing gas, the top wall of the lower cavity having a plurality of first through holes connected to the upper cavity; a closing component is provided in the lower cavity, the closing component comprising a piston cylinder, the piston cylinder having a first sliding cavity corresponding to a plurality of the first through holes one by one, each of the first sliding cavities being sealingly and slidingly assembled with a push piston, the push piston having a second through hole arranged longitudinally, the upper end of each of the push pistons being fixedly connected with a sealing member that seals the upper end of the second through hole and is used to abut against the top wall of the lower cavity to close the corresponding first through hole, the sealing member being made of hot-melt material, and the piston cylinder being filled with a pushing gas for applying an upward thrust to each of the sealing members.
[0006] Furthermore, the sealing assembly also includes a first sealing ring, which is located between the sealing member and the top wall of the lower cavity to seal the gap therebetween.
[0007] Furthermore, the first through hole includes a large diameter section and a small diameter section, the small diameter section is located above the large diameter section, and the first sealing ring abuts between the top wall of the large diameter section and the upper end of the blocking member.
[0008] Furthermore, the pushing gas component is an inert gas.
[0009] Furthermore, the piston cylinder has a second sliding cavity, and the second sliding cavity is sealingly and slidingly connected with a pressure regulating piston. The pressure regulating piston can axially adjust the front and rear position relative to the second sliding cavity to adjust the pressure of the pushing gas.
[0010] Furthermore, the circumferential surface of the pressure regulating piston has a first smooth section and an external thread section distributed front and back, and the inner side surface of the second sliding cavity has a second smooth section and an internal thread section distributed front and back. The pressure regulating piston is assembled in the second sliding cavity, and a sealed sliding connection is achieved through the sealing cooperation between the first smooth section and the second smooth section, and a threaded connection is achieved through the thread cooperation between the external thread section and the internal thread section.
[0011] When the pressure regulating piston rotates relative to the second sliding cavity, the external thread section cooperates with the internal thread section to drive the first smooth section to slide back and forth relative to the second smooth section.
[0012] Furthermore, the first smooth section has a first sealing ring assembly groove, a second sealing ring is assembled in the first sealing ring assembly groove, and the second sealing ring is used to seal the gap between the pressure regulating piston and the second sliding cavity.
[0013] Furthermore, the peripheral surface of the push piston has a second sealing ring assembly groove, and a third sealing ring is assembled in the second sealing ring assembly groove. The third sealing ring is used to seal the gap between the push piston and the first sliding cavity.
[0014] Furthermore, the battery box includes a frame, a support plate and a bottom guard plate. The support plate and the bottom guard plate are sealed and fixed to the lower end of the frame in sequence from top to bottom. The frame and the support plate enclose the upper cavity, and the support plate and the bottom guard plate enclose the lower cavity.
[0015] Furthermore, the piston cylinder is fixedly connected to the inner bottom wall of the bottom guard plate.
[0016] The present invention discloses a battery box with a fire extinguishing function. When the battery thermal runaway catches fire, the blocking piece will melt and open the first through hole, so that the fire extinguishing gas enters the upper cavity to extinguish the fire, so as to ensure the safety of the battery box and surrounding equipment. When any blocking piece corresponding to each upper cavity is melted, the remaining blocking pieces corresponding to the upper cavity will lose air pressure support, so that the remaining first through holes are opened, and decentralized air intake is realized, so as to greatly increase the diffusion speed of the fire extinguishing gas and ensure the fire extinguishing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0018] Figure 1 It is a structural schematic diagram of an embodiment of a battery box with a fire extinguishing function of the present invention;
[0019] Figure 2 for Figure 1 A schematic diagram of the structure enlargement at the center A;
[0020] Figure 3 It is a schematic cross-sectional structure diagram of an embodiment of a battery box with a fire extinguishing function of the present invention;
[0021] Figure 4 for Figure 3 A schematic diagram of the structure enlarged at B in the middle;
[0022] Figure 5 for Figure 4 A schematic diagram of the structure enlarged at C in the middle;
[0023] Figure 6 for Figure 4 A schematic diagram of the structure at D in the middle is enlarged;
[0024] Figure 7 This is a schematic diagram of an embodiment of a battery box with a fire extinguishing function of the present invention after the bottom guard plate is hidden;
[0025] Figure 8 for Figure 7 Enlarged schematic diagram of the structure at E in the middle.
[0026] The meanings of the symbols in the accompanying drawings are:
[0027] Battery box 1, upper cavity 1a, lower cavity 1b, first through hole 11, large diameter section 111, small diameter section 112, frame 12, support plate 13, bottom guard plate 14, closing assembly 2, piston cylinder 21, first sliding cavity 211, second sliding cavity 212, second smooth section 213, internal thread section 214, push piston 22, second sealing ring assembly groove 221, third sealing ring 222, second through hole 223, blocking piece 23, first sealing ring 231, pressure regulating piston 24, first smooth section 241, external thread section 242, first sealing ring assembly groove 243, second sealing ring 244. DETAILED DESCRIPTION
[0028] The present invention will be further described below in conjunction with the accompanying drawings.
[0029] Reference Figure 1-Figure 8As shown, the battery box 1 with fire extinguishing function of this embodiment has an upper cavity 1a and a lower cavity 1b distributed up and down, the upper cavity 1a is used to assemble batteries, the lower cavity 1b is used to store fire extinguishing gas, and the top wall of the lower cavity 1b has 5 first through holes 11 connected to the upper cavity 1a.
[0030] In this embodiment, the battery box 1 includes a frame 12, a support plate 13 and a bottom guard plate 14, and the support plate 13 and the bottom guard plate 14 are sealed and fixed to the lower end of the frame 12 from top to bottom. After the three are connected to each other, the frame 12 and the support plate 13 enclose an upper cavity 1a for assembling batteries. In this embodiment, there are two upper cavities 1a. The support plate 13 and the bottom guard plate 14 enclose a lower cavity 1b for storing fire extinguishing gas. In this embodiment, the first through hole 11 is specifically arranged on the support plate 13.
[0031] In this embodiment, a sealing component 2 is provided in the lower cavity 1b, and there are two sealing components 2, and the two sealing components 2 correspond to the two upper cavities 1a respectively. In this embodiment, the sealing component 2 includes a piston cylinder 21, and the piston cylinder 21 has a first sliding cavity 211 corresponding to the five first through holes 11. A push piston 22 is sealed and slidably assembled in each first sliding cavity 211, and the push piston 22 has a second through hole 223 arranged longitudinally. The upper end of each push piston 22 is fixedly connected to a plugging member 23 that seals the upper end of the second through hole 223 and is used to abut against the top wall of the lower cavity 1b to close the corresponding first through hole 11. The push piston 22 is fixedly connected to the lower end of the plugging member 23, and the plugging member 23 is made of hot-melt material. The piston cylinder 21 is filled with a pushing gas used to apply an upward thrust to each plugging member 23.
[0032] In this embodiment, the circumferential surface of the push piston 22 has a second sealing ring assembly groove 221 , in which a third sealing ring 222 is assembled. The third sealing ring 222 is used to seal the gap between the push piston 22 and the first sliding cavity 211 .
[0033] Under normal conditions, the pushing gas will exert an upward thrust on each blocking member 23 through each push piston 22, so that the blocking member 23 is tightly abutted against the top wall of the lower cavity 1b to close the corresponding first through hole 11, so that the connection between the upper cavity 1a and the lower cavity 1b is disconnected, and the fire extinguishing gas can be sealed and stored in the lower cavity 1b. In this embodiment, the fire extinguishing gas stored in the lower cavity 1b is in a high-pressure state, and the specific gas pressure is greater than the gas pressure in the upper cavity 1a.
[0034] When the battery in the upper cavity 1a ignites due to thermal runaway caused by a fault, the temperature inside the upper cavity 1a rises rapidly. Once the melting point of the hot-melt material of the plugging piece 23 is reached, the plugging piece 23 will melt under the high temperature, so that the upper cavity 1a and the lower cavity 1b are connected through the first through hole 11. In this way, the fire extinguishing gas in the lower cavity 1b can enter the upper cavity 1a through the first through hole 11 under the action of pressure difference, and inhibit the combustion of the battery by physically isolating oxygen, thereby playing a role in extinguishing the fire, so as to prevent the fire from spreading further, thereby ensuring the safety of the entire battery box and surrounding equipment.
[0035] It should be emphasized that when any one of the sealing pieces 23 corresponding to the upper cavity 1a is melted, the second through hole 223 in the corresponding push piston 22 will also be in a conducting state, so that the pushing gas in the piston cylinder 21 will be depressurized through the second through hole 223, and the remaining four sealing pieces 23 will lose air pressure support in the process, so that the four sealing pieces 23 will slide downward together with the corresponding push pistons 22 under the action of gravity, that is, they will be released from the contact with the top wall of the lower cavity 1b, so that the remaining four first through holes 11 corresponding to the upper cavity 1a will be conducted, and the fire extinguishing gas can enter the upper cavity 1a from these first through holes 11 to prevent the flame from spreading to the upper cavity 1a positions corresponding to these first through holes 11.
[0036] By allowing the fire extinguishing gas to enter the upper cavity 1a from multiple locations, it is possible to ensure that the fire extinguishing gas quickly and evenly fills the entire upper cavity 1a space in a short time. Since multiple first through holes 11 are connected at the same time, the gas is no longer limited to a single channel for release, and the decentralized air intake path greatly improves the diffusion efficiency of the fire extinguishing gas, allowing the fire extinguishing gas to reach various parts of the battery module faster.
[0037] It is worth mentioning that the hot-melt material can be selected according to actual needs, such as polyamide (PA), polyester (PET), etc.
[0038] Polyamide is a hot-melt material with excellent performance. It has a high melting point, generally around 200°C-300°C, which enables it to remain solid under normal battery operating temperature environment and stably block the first through hole 11. For example, within the operating temperature range of lithium batteries commonly used in electric vehicles (usually -20°C-60°C), the polyamide material blocking piece will not melt easily.
[0039] Polyamide also has good mechanical properties, and its strength and toughness can withstand a certain degree of external impact and vibration, preventing the plugging member 23 from being damaged or displaced during daily use of the battery box. Moreover, it has good chemical stability and has a certain tolerance to substances such as fire extinguishing gas and electrolyte that may leak from the battery, and will not deteriorate due to contact with these substances.
[0040] The melting point of polyester material is usually between 250℃-260℃, and this temperature range can effectively avoid melting under normal battery conditions. It is a thermoplastic polyester with excellent molding properties.
[0041] Polyester materials also have good chemical corrosion resistance and are resistant to various chemical substances that may exist in the battery box, such as organic solvents in the battery electrolyte. At the same time, its cost is relatively reasonable. When mass-producing battery boxes with fire extinguishing functions, production costs can be effectively controlled while ensuring performance.
[0042] The fire extinguishing gas used in the battery box can specifically be selected from carbon dioxide, nitrogen in the inert gas family, heptafluoropropane, etc.
[0043] Carbon dioxide (CO2) is one of the common candidate gases. It has the characteristics of high fire extinguishing efficiency and can effectively extinguish battery fires by diluting the oxygen concentration in the air to below the level required to support combustion. At the same time, the chemical properties of carbon dioxide are relatively stable and will not undergo violent chemical reactions with the electrolyte, electrode materials, etc. inside the battery, avoiding the production of additional harmful substances and reducing the risk of secondary hazards. Moreover, carbon dioxide gas is easy to obtain and store, and the cost is relatively controllable, making it suitable for large-scale application in battery box fire extinguishing systems.
[0044] Nitrogen (N2) in the inert gas family is also very popular. Nitrogen is extremely chemically inert and hardly reacts with any substance. Even in harsh environments where battery thermal runaway generates high temperatures and complex chemicals escape, it can remain stable, ensuring the safety of the fire extinguishing process. Its density is slightly lower than that of air, and it can diffuse well in the battery box, covering the fire area in all directions and inhibiting the spread of flames.
[0045] Heptafluoropropane (HFC-227ea) is also a suitable fire extinguishing gas. It has a fast fire extinguishing speed, can quickly block the combustion chain reaction, and effectively extinguish the initial fire. In addition, heptafluoropropane has a relatively short residual time in the atmosphere and has a small long-term impact on the environment, which is in line with the current green environmental protection concept. Although the cost is relatively high, it is an ideal choice for high-end battery application scenarios with strict requirements on fire extinguishing efficiency and environmental protection.
[0046] These fire-extinguishing gases are not used in isolation. Sometimes they are combined according to factors such as battery type, box volume, expected fire risk, etc., so as to customize the most appropriate fire-extinguishing plan and fully ensure the safety of the battery box.
[0047] In this embodiment, the composition of the pushing gas also uses a gas with fire extinguishing performance, preferably an inert gas such as nitrogen, argon, etc. This type of gas is selected as the pushing gas, on the one hand, because of its stable chemical properties, it will not chemically react with other components inside the battery box during storage and normal working conditions, ensuring the material stability of the closed components and the battery and other equipment, and avoiding corrosion, oxidation and other adverse phenomena that affect the life and performance of the device.
[0048] On the other hand, when a fire occurs, the blocking member 23 melts, and the second through hole 223 in the push piston 22 is opened to release the pressure of the pushing gas. The gas originally used to apply thrust is discharged into the upper cavity 1a. Since the gas has its own fire extinguishing properties, it can cooperate with the special fire extinguishing gas flowing in from the lower cavity 1b at high pressure, contributing extra strength in the fire suppression link and further improving the fire extinguishing performance.
[0049] In this embodiment, the sealing assembly 2 further includes a first sealing ring 231, which is located between the sealing member 23 and the top wall of the lower cavity 1b to seal the gap therebetween. Under normal working conditions, the pushing gas continuously applies upward pressure to the push piston 22, and this pressure is transmitted to the sealing member 23. The first sealing ring 231 will form an effective seal under the pushing action of the sealing member 23 and the top wall of the lower cavity 1b to prevent the fire extinguishing gas in the lower cavity 1b from entering the upper cavity 1a.
[0050] In this embodiment, the first through hole 11 includes a large diameter section 111 and a small diameter section 112, the small diameter section 112 is located above the large diameter section 111, and the first sealing ring 231 abuts between the top wall of the large diameter section 111 and the upper end of the blocking member 23. Such a setting can ensure that the first sealing ring 231 will not shift when affected by interference factors such as pushing gas pressure, daily slight vibrations, temperature changes, etc., so as to always maintain a good sealing state and ensure that the fire extinguishing gas in the lower cavity 1b will not leak to the upper part.
[0051] In this embodiment, the piston cylinder 21 has a second sliding cavity 212, and the second sliding cavity 212 is sealed and slidably connected with a pressure regulating piston 24. The pressure regulating piston 24 can axially adjust the front and rear position relative to the second sliding cavity 212 to adjust the pressure of the pushing gas.
[0052] Specifically, the circumferential surface of the pressure-regulating piston 24 has a first smooth section 241 and an external threaded section 242 distributed front to back, and the inner surface of the second sliding cavity 212 has a second smooth section 213 and an internal threaded section 214 distributed front to back. The pressure-regulating piston 24 is assembled in the second sliding cavity 212, and a sealed sliding connection is achieved through the sealing cooperation between the first smooth section 241 and the second smooth section 213, and a threaded connection is achieved through the threaded cooperation between the external threaded section 242 and the internal threaded section 214.
[0053] In addition, the first smooth section 241 has a first sealing ring assembly groove 243 , in which a second sealing ring 244 is assembled. The second sealing ring 244 is used to seal the gap between the pressure regulating piston 24 and the second sliding cavity 212 .
[0054] When the pressure of the pushing gas needs to be changed, the operator rotates the pressure regulating piston 24, and the external thread section 242 cooperates with the internal thread section 214 according to the principle of thread transmission to drive the first smooth section 213 to slide forward and backward along the axial direction of the second sliding cavity 212. If the pressure regulating piston 24 is pushed into the cavity, the space for the pushing gas is reduced, and the pressure increases accordingly; conversely, if the pressure regulating piston 24 is pulled outward, the gas space increases and the pressure decreases. This setting can adapt to different usage conditions by adjusting the pushing gas pressure.
[0055] In this embodiment, the five first through holes 11 corresponding to the upper cavity 1a are specifically distributed in an "X" shape, that is, four of the first through holes 11 are located at the four endpoints of the "X" shape, and the remaining one is located at the midpoint of the "X". This layout is conducive to the rapid and comprehensive distribution of fire-extinguishing gas. When the fire-extinguishing process is started, the fire-extinguishing gas in the lower cavity 1b in a high-pressure state rushes to the first through hole 11. The four first through holes 11 located at the four endpoints of the "X" shape can efficiently guide the gas to the edge area of the battery module, while the first through hole 11 at the midpoint of the "X" shape delivers a large amount of gas to the center of the battery module, prompting the central area to quickly obtain sufficient fire-extinguishing gas. Over time, the gases gushing out from the endpoints and the midpoint are intertwined and mixed with each other, ensuring that the gas concentration in the entire upper cavity 1a space rises evenly, so that every corner can be covered in time, maximizing the fire-extinguishing efficiency.
[0056] In this embodiment, the shape of the piston cylinder 21 is configured as an "X" shape corresponding to the distribution shape of the five first through holes 11. Each branch of the "X"-shaped piston cylinder 21 can accurately correspond to the first through hole 11 above, and the first sliding cavity 211 in each branch and the corresponding first through hole 11 are on the same vertical axis. This one-to-one corresponding layout can effectively ensure the gas flow efficiency.
[0057] In addition, the piston cylinder 21 is welded and fixed to the inner bottom wall of the bottom guard plate 14. This arrangement is equivalent to adding an additional support structure to the bottom guard plate 14, which can enhance the strength of the bottom guard plate 14.
[0058] In summary, the present invention discloses a battery box with a fire extinguishing function. When the battery thermal runaway catches fire, the blocking piece will melt and open the first through hole, allowing the fire extinguishing gas to enter the upper cavity to extinguish the fire, so as to ensure the safety of the battery box and surrounding equipment. When any blocking piece corresponding to each upper cavity is melted, the remaining blocking pieces corresponding to the upper cavity will lose air pressure support, allowing the remaining first through holes to be opened, realizing decentralized air intake, thereby greatly improving the diffusion speed of the fire extinguishing gas and ensuring the fire extinguishing efficiency.
[0059] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.
Claims
1. A battery box with fire extinguishing function, characterized in that: The battery box has an upper cavity and a lower cavity distributed up and down, the upper cavity is used to assemble batteries, and the lower cavity is used to store fire extinguishing gas, and the top wall of the lower cavity has a plurality of first through holes connected to the upper cavity; a closing component is provided in the lower cavity, and the closing component includes a piston cylinder, and the piston cylinder has a first sliding cavity corresponding to a plurality of the first through holes one by one, and each of the first sliding cavities is sealed and slidably equipped with a push piston, and the push piston has a second through hole arranged longitudinally, and the upper end of each of the push pistons is fixedly connected to a sealing member that seals the upper end of the second through hole and is used to abut against the top wall of the lower cavity to close the corresponding first through hole, and the sealing member is made of hot-melt material, and the piston cylinder is filled with a pushing gas for applying an upward thrust to each of the sealing members.
2. The battery box with fire extinguishing function according to claim 1, characterized in that: The sealing assembly further includes a first sealing ring, which is located between the sealing member and the top wall of the lower cavity to seal the gap therebetween.
3. The battery box with fire extinguishing function according to claim 1, characterized in that: The first through hole includes a large diameter section and a small diameter section, the small diameter section is located above the large diameter section, and the first sealing ring abuts between the top wall of the large diameter section and the upper end of the blocking member.
4. The battery box with fire extinguishing function according to claim 1, characterized in that: The pushing gas component is an inert gas.
5. The battery box with fire extinguishing function according to claim 1, characterized in that: The piston cylinder has a second sliding cavity, and the second sliding cavity is sealingly and slidingly connected with a pressure regulating piston. The pressure regulating piston can axially adjust the front and rear positions relative to the second sliding cavity to adjust the pressure of the pushing gas.
6. The battery box with fire extinguishing function according to claim 5, characterized in that: The circumferential surface of the pressure regulating piston has a first smooth section and an external thread section distributed front and back, and the inner side surface of the second sliding cavity has a second smooth section and an internal thread section distributed front and back. The pressure regulating piston is assembled in the second sliding cavity, and a sealed sliding connection is achieved through the sealing cooperation between the first smooth section and the second smooth section, and a threaded connection is achieved through the thread cooperation between the external thread section and the internal thread section; When the pressure regulating piston rotates relative to the second sliding cavity, the external thread section cooperates with the internal thread section to drive the first smooth section to slide back and forth relative to the second smooth section.
7. The battery box with fire extinguishing function according to claim 6, characterized in that: The first smooth section has a first sealing ring assembly groove, a second sealing ring is assembled in the first sealing ring assembly groove, and the second sealing ring is used to seal the gap between the pressure regulating piston and the second sliding cavity.
8. The battery box with fire extinguishing function according to claim 1, characterized in that: The circumferential surface of the push piston is provided with a second sealing ring assembly groove, in which a third sealing ring is assembled, and the third sealing ring is used to seal the gap between the push piston and the first sliding cavity.
9. The battery box with fire extinguishing function according to claim 1, characterized in that: The battery box includes a frame, a support plate and a bottom guard plate. The support plate and the bottom guard plate are sealed and fixed to the lower end of the frame from top to bottom. The frame and the support plate enclose the upper cavity, and the support plate and the bottom guard plate enclose the lower cavity.
10. The battery box with fire extinguishing function according to claim 9, characterized in that: The piston cylinder is fixedly connected to the inner bottom wall of the bottom guard plate.