Cover plate with injection molding structure

Abstract

The utility model provides an injection molding structure cover plate, the injection molding structure cover plate comprises a substrate, a lower insulating part, a pole and an upper injection molding part, the substrate is provided with a pole hole and an explosion-proof hole, the inner surface of the explosion-proof hole is provided with an explosion-proof membrane, and the explosion-proof membrane has a concave-convex structure and is M-shaped. A conical structure is arranged around the pole hole, a groove is formed in the inclined surface of the conical structure, and the upper injection molding part is provided with a convex structure so that the convex structure can be connected with the groove; the lower insulating part is also provided with a pole hole, a sealing ring is arranged between the lower insulating part and the substrate and corresponds to the position of the pole hole of the lower insulating part and the position of the pole hole of the substrate, the pole is composed of an upper pole and a lower pole, and both the upper pole and the lower pole are provided with pole bodies and hollow structures; the upper pole further comprises an upper pole cap, the lower pole further comprises a pole connecting piece, the design of the hollow structure of the upper pole and the hollow structure of the lower pole enables the pole to be better in heat dissipation effect and capable of bearing larger current, the design of the explosion-proof film does not need to add an additional protective film and does not need a nick structure, and the design of the conical structure does not need a stamping process.

Description

Technical Field

[0001] The utility model relates to an injection-molded structure cover plate, in particular to a lithium battery cover plate structure with good safety and reliability and the shape and connection mode of its accessories. Background Art

[0002] In the injection molding structure of the cover of the square aluminum shell battery, grooves or bosses are usually set around the pole holes of the substrate, and a positioning hole structure is used for positioning. In more complex structures, a riveted part is set on the surface of the substrate; the explosion-proof valve design of the cover adopts an aluminum film notch method, and a reinforcement structure is set in the explosion-proof hole on the upper surface of the substrate and a protective film is affixed to protect the explosion-proof valve. In terms of pole setting, there are simplified poles to save cover space. At the same time, the one-piece pole has higher strength than the simplified cover structure. The one-piece pole usually has an I-shaped, earth-shaped and other structures and has a large current capacity.

[0003] In existing solutions, the pole hole attachment substrate is configured with raised bosses, ribs, or grooves, along with positioning holes, requiring a stamping process. To overcome the complexity of this process, a cutting process is employed directly around the pole hole. A tapered concave structure is cut around the pole hole, and a rectangular groove is cut from the square aperture on the inclined surface of the concave structure to position the injection molded part. Scoring aluminum film for explosion-proof valves can provide a venting channel for the venting structure, but the scoring is prone to electrolyte accumulation and corrosion, leading to failure. Additional protective films and structures are required to prevent explosion-proof valve failure. Utility Model Content

[0004] The purpose of the present invention is to provide an injection-molded structure cover plate, which solves the above-mentioned background problems.

[0005] In order to achieve this purpose, the specific implementation methods are as follows:

[0006] The injection-molded structure cover includes a base plate, a lower insulating member and a pole; the base plate is provided with an upper pole hole and an explosion-proof hole, the explosion-proof hole is provided with an explosion-proof film, and there is a concave-convex structure on the explosion-proof film; the lower insulating member is provided with a lower pole hole; the base plate and the lower insulating member are connected to the pole hole through the pole passing through the pole hole.

[0007] Preferably, a conical structure is provided around the upper pole hole, and a plurality of grooves are provided on the conical inclined surface of the conical structure.

[0008] Preferably, the pole comprises an upper pole and a lower pole, the lower pole is composed of a pole connecting piece and a pole body, and a hollow structure is provided in the pole body; the upper pole is composed of a pole body and an upper pole cap, and a hollow structure is provided in the upper pole.

[0009] Preferably, the explosion-proof membrane is provided on the inner surface of the explosion-proof hole. The explosion-proof membrane is formed by integrally punching an aluminum membrane. A thin concave-convex structure is punched on the explosion-proof membrane, and the structure is M-shaped as a whole.

[0010] Preferably, the upper injection molded part fills the gap between the pole and the substrate, and the upper injection molded part has a protruding structure.

[0011] Preferably, the protruding structure in the upper injection molded part is embedded in the groove.

[0012] Preferably, the substrate and the lower insulating member are connected via the upper pole and the lower pole and their sealing rings.

[0013] Preferably, the upper pole sleeve is connected to the lower pole through the hollow structure of the upper pole body and the hollow structure of the lower pole body.

[0014] Preferably, when the substrate is connected to the lower insulating member, the lower pole passes through the lower pole hole of the lower insulating member and the sealing ring and the upper pole hole of the substrate.

[0015] Preferably, a lower pole column hollow structure is provided in the lower pole column, and the lower pole column hollow structure does not penetrate the lower pole column.

[0016] The beneficial effects of this experimental design are as follows: the injection-molded cover plate has a simple production process, strong pole current capacity, good pole heat dissipation, and high safety. The combined hollow pole has a high current capacity and excellent heat dissipation performance; the base plate pole hole structure is simple, eliminating the need for a stamping process and ensuring a stable injection molded part; the explosion-proof valve is stamped from aluminum film, eliminating the need for notched structures or reinforcing ribs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the exploded structure diagram of the utility model.

[0018] Figure 2 This is an exploded structural diagram of the cover plate of the present invention.

[0019] Figure 3 This is the cross section of the cover plate of the present invention.

[0020] In the above drawings: 5, substrate; 3, lower insulating member; 2, pole; 51, upper pole hole; 52, conical structure; 53, groove; 54, explosion-proof hole; 31, lower pole hole; 22, upper pole; 21, lower pole; 211, lower pole body; 212, lower pole body hollow structure; 213, lower pole body connecting piece; 22, upper pole; 221, upper pole body; 223, upper pole body hollow structure; 222, upper pole cap; 4, sealing ring; 6, upper injection molded part; 61, upper injection molded part raised structure; 7, explosion-proof membrane; 71, explosion-proof membrane concave and convex structure. DETAILED DESCRIPTION

[0021] like Figure 1As shown, the exploded structure diagram of the present invention shows an innovative injection-molded structural cover plate, which is mainly composed of a substrate 5 and a lower insulating member 3. Specifically, pole holes 51 are provided on the opposite outer sides of the substrate 5. The design of these holes is intended to facilitate subsequent connections. Explosion-proof holes 54 are provided between the pole holes 51 on the substrate 5 to enhance the safety of the overall structure. The inner surface of the explosion-proof hole 54 is provided with an explosion-proof film 7, which has an important protective function, and its surface is also designed with a concave-convex structure 71 to more effectively disperse the force and prevent the leakage of explosive gas. The lower insulating member 3 is also provided with pole holes 31 on its opposite outer sides, and the positions of these holes are just below the pole holes 51 on the opposite outer sides of the substrate 5, ensuring a tight fit of the entire structure. In addition, there is a sealing ring 4 between the pole hole 51 and the pole hole 31. The setting of this sealing ring can effectively prevent the leakage of liquid or gas and ensure the sealing of the system. The substrate 5 and the lower insulator 3 are connected together through the pole 2, which consists of a lower pole 21 and an upper pole 22. The lower pole 21 is composed of a pole connecting piece 211 and a lower pole body 212. The lower pole body 212 has a hollow structure 213 inside, but this structure does not pass through the lower pole 21 to maintain its strength and stability. The upper pole is composed of an upper pole body 221 and an upper pole cap 222. The upper pole body has a hollow structure 223 that passes through it to further reduce weight and improve heat dissipation performance. In the entire structure, the upper injection molded part 6 fills the gap between the pole and the substrate 5, and there are several raised structures 61 on the upper injection molded part. These raised structures form a good fit with the conical structure 52 around the pole hole 51. It is worth noting that the conical inclined surface of the conical structure 52 is provided with grooves 53. The presence of these grooves enables the upper injection molded part 6 to form a more secure connection with the pole hole 51 during installation. When the base plate 5 is connected to the lower insulator 3, the upper molded part 6 connects to the pole hole 51. The grooves 53 in the upper molded part 6 correspond one-to-one with the raised structures 61 therein, allowing the raised structures 61 of the upper molded part to fit into the grooves 53 on the conical structure 52, thereby ensuring that the upper molded part 6 is accurately connected to the corresponding position of the pole hole 51 of the base plate 5. After this operation is completed, the upper pole body 221 of the upper pole is connected to the upper molded part 6 to form a single unit, so that the hollow structure 223, upper pole body 221, and upper pole cap 222 of the upper pole are all located directly above the upper pole hole 51 and the conical structure 52. After this series of operations is completed, the sealing ring 4 is located directly below the upper pole hole 51 and directly above the pole hole 31 of the lower insulator 3.The lower pole body 212 on the lower pole 21 passes through the lower pole hole 31 of the lower insulating member 3, and finally forms a closed structure, ensuring that the sealing ring 4 between the substrate 5 and the lower insulating member 3, the upper pole hole 51 and the upper injection molded part 6 form an effective connection, thereby achieving a tight connection between the lower pole 21 and the upper pole 22.

[0022] like Figure 2 As shown, the exploded structural diagram of the cover of the present invention shows in detail the composition of the upper pole 22, which is mainly composed of the upper pole cap 222, the upper pole body 221 and the upper pole body hollow structure 223. The design of the upper pole body 221 not only takes into account strength and stability, but also forms an inner hollow cylinder through the hollow structure 223. This structure can reduce weight while also improving heat dissipation performance. At the same time, the lower pole 21 is mainly composed of a pole connecting piece 211 and a pole body 212, wherein the lower pole body hollow structure 213 is provided in the pole body 212. Such a design enables the lower pole 21 to have good heat dissipation performance while maintaining a certain strength. The outer diameter of the body 212 of the lower pole 21 is slightly smaller than the inner diameter of the hollow structure 223 of the upper pole 22. Such a proportional design ensures that the lower pole 21 is inserted into the middle of the upper pole 22, and is sealed and connected together by means of riveting or welding. This allows the two to work better together during assembly. This design concept not only enhances the overall performance of the structure, but also provides higher safety and durability for subsequent use, ensuring good functionality and stability under various working conditions.

[0023] The hollow structure of the terminal not only significantly enhances its high-current handling capacity but also significantly improves its heat dissipation performance. This design cleverly addresses the thermal management challenges faced by traditional solid terminals in high-power applications. The hollow structure addresses this challenge by increasing the heat dissipation surface area, effectively improving heat dissipation efficiency. The hollow design fully exploits the principle that heat transfer efficiency is proportional to surface area. The hollow design not only retains the heat dissipation capacity of the outer surface but also creates a new heat dissipation area on the inner surface, creating a more efficient heat exchange system. This dual-layer heat dissipation structure allows heat to be dissipated both internally and externally, significantly increasing heat dissipation per unit time. Furthermore, the hollow structure facilitates the circulation of air or coolant, further enhancing heat dissipation. This design not only improves battery safety and reliability but also paves the way for the development of high-power density batteries, with significant implications for the development of electric vehicles, energy storage systems, and other fields.

[0024] More importantly, the hollow structure offers significant advantages in heat transfer, providing more paths for heat dissipation. In a solid pole, the heat generated in the center needs to be conducted outward through the thermal conductivity of the material, first reaching the surface and then dissipating into the surrounding environment. This process is not only time-consuming, but also, during the heat transfer process, heat may accumulate due to the thermal conductivity limitations of the material, thereby affecting the overall heat dissipation effect and efficiency. In contrast, the hollow pole design is more efficient. The heat generated internally can be quickly dissipated directly through the inner surface. The openness of this structure greatly shortens the heat transfer path and reduces heat loss during conduction. Because heat is more easily released into the environment from the inner surface, this design significantly improves heat dissipation efficiency, allowing the device to maintain a lower temperature during use, thereby extending its service life and improving overall performance. Therefore, adopting a hollow structure is an effective way to optimize thermal management and improve heat dissipation, especially in high-power density application scenarios, which can better meet heat dissipation requirements and ensure stable operation of the equipment.

[0025] In addition, the hollow structure also provides ample room for subsequent performance optimization. For example, internal cooling channels can be designed and liquid cooling systems can be introduced to achieve more efficient thermal management. The flexibility of this design allows the pole to adapt to a variety of different application scenarios and heat dissipation requirements. From the perspective of manufacturing process, although the production of hollow poles is more complicated than solid poles, modern manufacturing technology can already meet this demand well. Common manufacturing methods include extrusion molding and precision machining. Extrusion molding is suitable for mass production and can directly produce the required hollow cross-section. Precision machining is more suitable for small-batch or customized production, and can form a hollow structure in solid materials through methods such as deep hole drilling. The second issue is the sealing problem. In some applications, the pole needs to withstand high pressure or prevent the infiltration of harmful substances.

[0026] like Figure 3The cross-section of the cover plate of the present invention is shown in the figure. The explosion-proof cover plate 7 has a concave-convex structure 71, forming an overall M-shaped design. This design offers several significant advantages. First, the M-shaped structure increases the effective area of ​​the membrane, providing greater room for deformation while maintaining the overall dimensions. This means that when internal battery pressure rises, the membrane can better absorb and buffer pressure changes, extending the time from the initial pressure increase to membrane rupture, providing valuable reaction time for the battery management system to implement other safety measures. Second, the central recessed portion of the M-shaped structure naturally forms a predetermined rupture zone, where the membrane thickness is thinnest, ensuring that it ruptures preferentially at this location when the critical pressure is reached. This controlled rupture behavior significantly improves the reliability and consistency of the explosion-proof membrane and reduces the safety hazards that may arise from random rupture. Furthermore, the two raised portions of the M-shaped structure provide support and cushioning. Under normal operating conditions, they can withstand certain pressure fluctuations without causing membrane rupture, thereby improving system stability. As the pressure continues to rise to the critical point, the two raised portions further deform, absorbing more energy before rupture, making the rupture process smoother and more controllable. This gradual rupture mechanism helps reduce the impact force at the moment of rupture and minimizes potential secondary damage to surrounding components. The M-shaped structure also optimizes the seal between the film and the battery casing. The concave-convex structure increases contact area and contact pressure, creating a more reliable seal that effectively prevents electrolyte leakage and the intrusion of external contaminants under normal operating conditions. Furthermore, this structure exhibits a degree of adaptability, compensating for minor deformation caused by temperature fluctuations or long-term use, maintaining a good seal. From a production perspective, the M-shaped explosion-proof film also offers advantages. This shape can be mass-produced using precision stamping or molding processes, resulting in high production efficiency and relatively low cost. The M-shaped structure's distinct geometric features facilitate in-line inspection and quality control, allowing for rapid and accurate measurement of critical dimensions using optical or mechanical methods to ensure that each product meets stringent specifications. Regarding material utilization, the M-shaped structure allows for the use of relatively thin raw materials, which can be stamped to achieve the desired thickness distribution in key areas. This not only saves raw materials but also optimizes the overall weight and thickness of the film, contributing to a lightweight battery design. At the same time, this structural design also provides greater room for the performance of the material, which can maximize the sensitivity and responsiveness of the film while ensuring strength. From the perspective of mechanical properties, the M-type structure provides excellent stress distribution. Under normal working pressure, the stress is mainly concentrated in the two raised parts, while the central recessed area is less stressed. Such stress distribution is conducive to extending the service life of the film. When the pressure reaches the critical value, the stress will gradually concentrate towards the center, guiding the rupture process. This gradual stress transfer process not only improves the reliability of the film, but also makes the rupture process more controllable and predictable.

[0027] The present utility model has explained its purpose, technical solutions and beneficial effects in depth through specific embodiments, but these embodiments are only used as examples to demonstrate the application of the invention and do not constitute a limitation on the scope of protection of the present invention. We explicitly point out that any reasonable modification, equivalent replacement or technical improvement under the guidance of the spirit and principles of the present invention should be included in the scope of protection of the present utility model. This means that as long as these changes do not deviate from the core idea and basic function of the invention, they should be protected by patent rights. The scope of protection of the present invention should be broad, including all direct and obvious variants and non-obvious innovations that technical experts can reasonably deduce based on the disclosure of the present invention. This broad protection is intended to promote further research and development based on the present invention, while ensuring that its innovation and practicality are fully legally protected.

Claims

1. An injection molded structural cover plate, characterized in that: The injection-molded structure cover comprises a base plate (5), a lower insulating member (3) and a pole (2); the base plate (5) is provided with an upper pole hole (51) and an explosion-proof hole (54); the explosion-proof hole (54) is provided with an explosion-proof membrane (7), and a concave-convex structure (71) exists on the explosion-proof membrane (7); the lower insulating member (3) is provided with a pole hole (31); the base plate (5) and the lower insulating member (3) are connected to the lower pole hole (31) through the pole (2) passing through the upper pole hole (51).

2. The injection molded structural cover according to claim 1, characterized in that A conical structure (52) is provided around the upper pole hole (51), and a groove (53) is provided on the conical inclined surface of the conical structure (52).

3. The injection molded structural cover according to claim 2, characterized in that The pole (2) comprises an upper pole (22) and a lower pole (21); the lower pole (21) is composed of a pole connecting piece (211) and a pole body (212); a hollow structure (213) is provided inside the pole body (212); and the upper pole (22) is composed of a pole body (221) and an upper pole cap (222); a through-hollow structure (223) is provided inside the upper pole.

4. The injection-molded structural cover according to any one of claims 1 to 3, characterized in that: The explosion-proof membrane (7) is provided on the inner surface of the explosion-proof hole (54). The explosion-proof membrane (7) is formed by integrally punching an aluminum membrane. A thin concave-convex structure (71) is punched on the explosion-proof membrane (7), and the overall structure presents an M shape.

5. The injection-molded structural cover plate according to claim 2, characterized in that: The upper injection molded part (6) is filled in the gap between the pole (2) and the base plate (5), and the upper injection molded part (6) has a convex structure.

6. The injection-molded structural cover plate according to claim 5, characterized in that: The protruding structure (61) in the upper injection molded part (6) is embedded in the groove (53).

7. The injection-molded structural cover plate according to claim 3, characterized in that: The substrate (5) and the lower insulating member (3) are connected via the upper pole (22) and the lower pole (21) and the sealing ring (4).

8. The injection-molded structural cover plate according to claim 3 or 7, characterized in that: The hollow structure (223) of the upper pole (22) is sleeved on the pole body (212) of the lower pole (21); the pole body (212) passes through the hollow structure (223), and is sealed from the top of the upper pole (22) by laser welding or riveting.

9. The injection-molded structural cover plate according to claim 3, characterized in that: The hollow structure (213) provided in the pole body (212) of the lower pole does not penetrate the lower pole (21).

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