Battery shell
By designing an annular protrusion and a glue injection groove in the lithium battery casing, and combining the soft and hard shells with waterproof pillars and waterproof rings, the problem of separation gaps between the hard and soft plastic shells is solved, achieving efficient sealing and improved waterproof performance of the battery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TWS TECH GUANGZHOU LTD
- Filing Date
- 2025-04-09
- Publication Date
- 2026-05-15
AI Technical Summary
In existing waterproof structures for lithium batteries, the difference in physical properties between the hard plastic shell and the soft plastic shell makes it easy for the injection port to separate, thus failing to achieve the IP68 waterproof effect.
Design a battery casing including annular bosses and injection grooves at both ends of an injection hole. The annular bosses surround the injection hole to provide a physical limiting barrier to restrict the cooling and shrinkage of the soft glue. The design of the soft and hard casings and the waterproof pillars and waterproof rings form a sealing structure.
It improves the battery's sealing and waterproof performance, meets the IP68 waterproof rating requirements, reduces the formation of gaps, and enhances overall waterproof reliability.
Smart Images
Figure CN224248802U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of batteries, and in particular to a battery casing. Background Technology
[0002] Currently, the commonly known waterproof structure for lithium batteries consists of an outer hard plastic shell and a soft plastic filler. The soft plastic wraps around and protects the solder joints of the PCB board inside the lithium battery, enabling the lithium battery assembly to achieve an IP68 waterproof rating. However, the soft plastic is a hot melt adhesive (around 200 degrees Celsius). Under normal, uncontrolled conditions, it will shrink upon natural cooling. The hard plastic shell has different physical properties than the soft plastic, which means there is a chance of separation gaps at the soft plastic injection port on the hard plastic shell. This can lead to water ingress and prevent the IP68 waterproof rating from being achieved. Utility Model Content
[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. It provides a battery casing that improves the sealing of the battery's injection holes, thereby enhancing the waterproof performance of the battery casing.
[0004] To achieve the above objectives, this utility model provides a battery casing, including a first housing, the first housing having an injection hole, the first housing having an outer side and an inner side arranged opposite to each other, the two ends of the injection hole passing through the outer side and the inner side respectively, the inner side having an injection groove, the opening of the injection groove facing the inner side, the injection groove and the injection hole forming an annular boss in the radial direction, the annular boss surrounding the injection hole.
[0005] As a preferred embodiment, the glue injection groove, the annular boss, and the glue injection through hole are coaxially arranged.
[0006] As a preferred embodiment, the diameter of the injection hole is set between 1mm and 3mm.
[0007] As a preferred embodiment, the annular boss has a boss end face at one end away from the outer side, and the boss end face protrudes towards the inner side to form a boss protrusion, and the bottom surface of the glue injection groove is located between the boss end face and the outer side.
[0008] As a preferred embodiment, the boss protrusion is provided in multiple ways, and the multiple boss protrusions are arranged at intervals along the circumference of the annular boss.
[0009] As a preferred embodiment, the width 'a' of the annular boss in the radial direction is set to 0.4mm-0.5mm.
[0010] As a preferred embodiment, the width b of the glue injection groove in the radial direction is set to 1.2mm-1.5mm.
[0011] As a preferred embodiment, the system further includes a second housing, the second housing having a lower hardness than the first housing. The second housing includes a connecting layer, a waterproof column, and a waterproof ring. The waterproof column is located inside the waterproof ring and is inserted into the glue injection through hole. The outer peripheral surface of the waterproof column is in contact with the inner peripheral surface of the glue injection through hole. The waterproof ring is inserted into the glue injection groove. The inner peripheral surface of the waterproof ring is in contact with the outer peripheral surface of the annular boss, and the outer peripheral surface of the waterproof ring is in contact with the inner wall of the glue injection groove.
[0012] As a preferred embodiment, the connecting layer, the waterproof column, and the waterproof ring are integrally formed.
[0013] Compared with the prior art, the battery casing of this utility model has the following advantages: The first casing has an injection hole, and the first casing has an outer side and an inner side arranged opposite to each other. The two ends of the injection hole penetrate the outer side and the inner side respectively. By forming a soft rubber column inside the injection hole, the soft rubber column seals the injection hole, thereby achieving a sealed and waterproof effect. The inner side has an injection groove with its opening facing inward. Soft rubber is injected into the injection groove. An annular boss is formed radially between the injection groove and the injection hole, surrounding the injection hole. The annular boss provides a physical limiting barrier, restricting the movement of the soft rubber in the circumferential direction when it cools and shrinks, thereby controlling the shrinkage of the soft rubber during cooling, reducing the formation of gaps, improving sealing performance, and thus meeting waterproof requirements. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of the first housing in an embodiment of this utility model.
[0015] Figure 2 This is an embodiment of the present utility model. Figure 1 A magnified structural diagram of point A in the diagram.
[0016] Figure 3 This is a cross-sectional view of the overall structure of an embodiment of this utility model.
[0017] Figure 4 This is an embodiment of the present utility model. Figure 3 A magnified structural diagram of point B in the diagram.
[0018] Figure 5 This is a schematic diagram of the structure of the second shell in an embodiment of this utility model.
[0019] Figure 6 This is a schematic diagram of the component disassembly structure of an embodiment of this utility model.
[0020] In the picture:
[0021] 10. First housing; 11. Injection hole; 12. Outer side; 13. Inner side; 14. Injection groove; 15. Annular boss; 16. Boss end face; 17. Boss protrusion;
[0022] 20. Second shell; 21. Connecting layer; 22. Waterproof column; 23. Waterproof ring;
[0023] 30. PCB board. Detailed Implementation
[0024] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0025] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" used to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 this utility model.
[0026] In the description of this utility model, it should be understood that the terms "connected," "linked," and "fixed," etc., used in this utility model should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a welded connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0027] like Figures 1 to 6 As shown, a preferred embodiment of the present invention provides a battery casing including a first housing 10. The first housing 10 has an injection hole 11. The first housing 10 has an outer side 12 and an inner side 13 arranged opposite to each other. The two ends of the injection hole 11 pass through the outer side 12 and the inner side 13 respectively. The inner side 13 is provided with an injection groove 14. The opening of the injection groove 14 faces the inner side 13. An annular boss 15 is formed between the injection groove 14 and the injection hole 11 in the radial direction. The annular boss 15 surrounds the injection hole 11.
[0028] The battery casing of this utility model has a first housing 10 with a glue injection through hole 11. The first housing 10 has an outer side 12 and an inner side 13 arranged opposite to each other. The two ends of the glue injection through hole 11 pass through the outer side 12 and the inner side 13 respectively. By forming a soft glue column in the glue injection through hole 11, the soft glue column seals the glue injection through hole 11, thereby achieving a waterproof seal. The inner side 13 is provided with a glue injection groove 14, the opening of which faces the inner side 13. Soft glue is injected into the glue injection groove 14. An annular boss 15 is formed radially between the glue injection groove 14 and the glue injection through hole 11. The annular boss 15 surrounds the glue injection through hole 11 and provides a physical limiting barrier. When the soft glue cools and shrinks, it restricts the movement of the soft glue in the circumferential direction, thereby controlling the shrinkage of the soft glue during cooling, reducing the formation of gaps, improving sealing performance, and thus meeting waterproof requirements.
[0029] Furthermore, such as Figures 1 to 4 As shown, the glue injection groove 14, the annular boss 15, and the glue injection through hole 11 are coaxially arranged. The coaxial limiting function of the annular boss 15 is aligned with the axes of the glue injection groove 14 and the glue injection through hole 11, which can convert the radial stress generated during the cooling and shrinkage of the soft glue into axial restraint force, significantly reducing the risk of lateral shrinkage deformation and preventing the formation of separation gaps between the edge of the annular boss 15 and the soft glue. The coaxial arrangement makes the glue injection groove 14, the annular boss 15, and the glue injection through hole 11 form a concentric circle structure. After the soft glue cures, the contact interface with the hard glue shell is symmetrically distributed in both the circumferential and axial directions, improving the mechanical balance of the sealing interface, avoiding local stress concentration caused by asymmetrical shrinkage, and thus enhancing the reliability of the overall waterproof performance.
[0030] Furthermore, such as Figures 1 to 4 As shown, the diameter of the injection hole 11 is set between 1mm and 3mm. Setting the injection hole 11 within a smaller diameter range reduces the volume of soft glue injected in a single application. Since the cooling rate of the soft glue after hot melting is inversely proportional to its volume, a smaller glue column can achieve internal and external temperature equilibrium more quickly, shortening the overall cooling time. This effectively reduces the excessive shrinkage rate of the soft glue caused by prolonged cooling (especially in the edge area of the injection hole 11), thereby reducing the risk of shrinkage stress concentration and gap formation.
[0031] Furthermore, such as Figure 2As shown, the annular boss 15 has a boss end face 16 at the end opposite to the outer side 12. The boss end face 16 protrudes towards the inner side 13 to form a boss protrusion 17. The bottom surface of the injection groove 14 is located between the boss end face 16 and the outer side 12. By setting the boss protrusion 17, the contact area of the soft rubber on the boss end face 16 is increased, which improves the mechanical interlocking strength between the soft rubber and the hard rubber shell, i.e., the first shell 10. Even if the soft rubber undergoes volume changes due to thermal expansion and contraction, it can maintain adhesion through the "anchoring effect" of the texture, reducing the possibility of gaps. At the same time, the boss protrusion 17 disperses the shrinkage stress of the soft rubber, preventing the injection port edge from separating due to unidirectional shrinkage of the soft rubber.
[0032] Furthermore, such as Figure 2 As shown, multiple bosses 17 are provided, and the multiple bosses 17 are spaced apart along the circumference of the annular boss 15.
[0033] Furthermore, such as Figure 4 As shown, the radial width 'a' of the annular boss 15 is set at 0.4mm-0.5mm. A wider radial width provides a wider support interface for the soft adhesive, significantly improving the physical restraint effect on the adhesive's cooling shrinkage. The wider annular boss 15 also forms a wider sealing band during the injection molding process. Even with minor shrinkage fluctuations or filling deviations during the cooling process, the wide annular boss 15 still provides sufficient contact area to maintain sealing, improving the process tolerance and reliability of the waterproof structure.
[0034] Furthermore, such as Figure 4 As shown, the width b of the dispensing groove 14 in the radial direction is set to 1.2mm-1.5mm. After the soft glue is injected, it provides a certain lateral diffusion space, and the glue can be evenly distributed radially in the groove, reducing uneven filling or air bubble residue caused by narrow flow path.
[0035] Furthermore, such as Figures 5 to 6As shown, it also includes a second housing 20, the hardness of which is less than that of the first housing 10. The second housing 20 includes a connecting layer 21, a waterproof column 22, and a waterproof ring 23. The waterproof column 22 is located inside the waterproof ring 23 and is inserted into the glue injection through hole 11. The outer peripheral surface of the waterproof column 22 is in contact with the inner peripheral surface of the glue injection through hole 11. The waterproof ring 23 is inserted into the glue injection groove 14. The inner peripheral surface of the waterproof ring 23 is in contact with the outer peripheral surface of the annular boss 15, and the outer peripheral surface of the waterproof ring 23 is in contact with the inner wall of the glue injection groove 14. The entire second housing 20 is made of soft rubber and is used to include the PCB board 30 and to seal the glue injection through hole 11 to improve the waterproof effect. The connecting layer 21 is used to connect the waterproof column 22 and the waterproof ring 23 to form a whole. The waterproof column 22 is used to seal the glue injection through hole 11 so that the glue injection through hole 11 is sealed and waterproof. The shape of the waterproof ring 23 matches the glue injection groove 14, and the waterproof ring 23 achieves further sealing and improves the waterproof effect.
[0036] Furthermore, such as Figures 4 to 5 As shown, the connecting layer 21, waterproof pillar 22, and waterproof ring 23 are integrally formed. The second housing 20 is used to wrap the PCB board 30. The PCB board 30 assembly is pressed into the first housing 10 to form a product component. After ensuring a close fit, the product component is placed in a mold for forming the second housing 20. LPM soft glue is injected into the product using an LPM low-pressure injection molding machine. The LPM soft glue forms waterproof pillar 22 in the injection hole 11 and waterproof ring 23 in the injection groove 14. A connecting layer 21 is formed above the annular boss 15. After cooling, the integrally formed second housing 20 is formed, thus completing the wrapping of the PCB board 30 and the sealing of the injection hole 11, and finally completing the lithium battery product. Using this structure will meet the IP68 waterproof performance requirements.
[0037] In summary, this utility model embodiment provides a battery casing. A first casing 10 has an injection hole 11. The first casing 10 has an outer side 12 and an inner side 13 arranged opposite to each other. The two ends of the injection hole 11 penetrate the outer side 12 and the inner side 13 respectively. A soft rubber column is formed inside the injection hole 11, sealing the injection hole 11 and achieving waterproofing. The inner side 13 has an injection groove 14, with its opening facing inwards. Soft rubber is injected into the injection groove 14. An annular boss 15 is formed radially between the injection groove 14 and the injection hole 11, surrounding the injection hole 11. The annular boss 15 provides a physical limiting barrier, restricting the movement of the soft rubber in the circumferential direction during cooling and shrinkage, thereby controlling the shrinkage of the soft rubber during cooling, reducing the formation of gaps, improving sealing, and thus meeting waterproofing requirements.
[0038] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this utility model, and these improvements and substitutions should also be considered within the protection scope of this utility model.
Claims
1. A battery casing, characterized in that: The device includes a first housing with an injection hole. The first housing has an outer side and an inner side arranged opposite to each other. The two ends of the injection hole pass through the outer side and the inner side, respectively. The inner side is provided with an injection groove with the opening facing the inner side. An annular boss is formed between the injection groove and the injection hole in the radial direction. The annular boss surrounds the injection hole.
2. The battery casing according to claim 1, characterized in that: The glue injection groove, the annular boss, and the glue injection through hole are coaxially arranged.
3. The battery casing according to claim 1, characterized in that: The diameter of the injection hole is set between 1mm and 3mm.
4. The battery casing according to claim 1, characterized in that: The annular boss has a boss end face at one end away from the outer side, and the boss end face protrudes towards the inner side to form a boss protrusion. The bottom surface of the glue injection groove is located between the boss end face and the outer side.
5. The battery casing according to claim 4, characterized in that: The boss has multiple protrusions, which are spaced apart circumferentially along the annular boss.
6. The battery casing according to claim 2, characterized in that: The radial width 'a' of the annular boss is set at 0.4mm-0.5mm.
7. The battery casing according to claim 1, characterized in that: The width b of the glue injection groove in the radial direction is set at 1.2mm-1.5mm.
8. The battery casing according to claim 1, characterized in that: It also includes a second housing, the hardness of which is less than that of the first housing. The second housing includes a connecting layer, a waterproof column, and a waterproof ring. The waterproof column is located inside the waterproof ring and is inserted into the glue injection through hole. The outer peripheral surface of the waterproof column is in contact with the inner peripheral surface of the glue injection through hole. The waterproof ring is inserted into the glue injection groove. The inner peripheral surface of the waterproof ring is in contact with the outer peripheral surface of the annular boss, and the outer peripheral surface of the waterproof ring is in contact with the inner wall of the glue injection groove.
9. The battery casing according to claim 8, characterized in that: The connecting layer, the waterproof column, and the waterproof ring are integrally formed.