A battery pack structure

Abstract

The utility model discloses a battery package structure, including electric core subassembly, shell subassembly and output subassembly, shell subassembly is hollow structure, including upper cover, bottom shell and end cover, and the waterproof ultrasonic groove is provided with around bottom shell, and the upper cover is equipped with the sealing structure of cooperation with waterproof ultrasonic groove, and waterproof ultrasonic groove and sealing structure are all ultrasonic welding shear type structure, the upper cover is welded with sealing structure ultrasonic through waterproof ultrasonic groove with bottom shell, and the end cover is assembled in the tail end of bottom shell along length direction close to output subassembly one side, and the electric core subassembly is embedded in shell subassembly, the utility model discloses the waterproof ultrasonic groove of battery package structure bottom shell and the sealing structure of upper cover adopt shear type ultrasonic welding design and can effectively block liquid invasion, realize IP68 level standard waterproof, and the structure upper cover's clamping hook and bottom shell's clamping hook card groove structure and ultrasonic welding's double fixed, when falling impact, shell subassembly is not easy to crack, satisfies 2.8M drop and 2 round 6 face cylinder 1M4000 times test's requirement.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, specifically a battery pack structure for a handheld device. Background Technology

[0002] A battery pack is a module formed by combining multiple individual battery cells. When in use, a battery pack can provide higher voltage and higher capacity. Therefore, battery packs have a relatively wide range of applications. However, there are also some problems with the design structure of battery packs: existing battery packs generally use a top shell and bottom shell fixed with screws. This structure has poor waterproof performance, and rainwater can easily enter the battery, causing short circuits and affecting people's use; the existing series and parallel battery pack structure design has weak drop resistance and pressure resistance. The traditional battery pack has a drop resistance height of 1.2M, which cannot meet the drop resistance requirements of higher heights.

[0003] Therefore, this utility model proposes a battery pack structure to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a battery pack structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a battery pack structure, including a cell assembly, a shell assembly, and an output assembly. The shell assembly is a hollow structure, including a top cover, a bottom shell, and an end cover. A waterproof ultrasonic groove is provided around the bottom shell, and the top cover is provided with a sealing structure that cooperates with the waterproof ultrasonic groove. Both the waterproof ultrasonic groove and the sealing structure are ultrasonic welding and shearing type structures. The top cover and bottom shell are ultrasonically welded to the sealing structure via a waterproof ultrasonic groove. The end cover is assembled at the tail end of the bottom shell along the length direction near the output component. The battery cell assembly is embedded in the outer shell assembly.

[0006] Furthermore, the top cover is provided with hooks, which are evenly distributed around the top cover, and the bottom shell is provided with the same number of hook slots at the corresponding positions of the hooks. The output components include metal springs and metal nuts, which are integrally formed and connected to the bottom shell using an in-mold molding process.

[0007] Furthermore, it also includes a protective plate and a bracket. The protective plate is fixed inside the bottom shell. The protective plate is provided with through holes, which match the size and shape of the metal springs. The through holes pass through the metal springs one by one and are welded. The bracket is fixed inside the bottom shell by silicone around the bottom shell. The protection board includes a PCBA rigid board, an FPC flexible board, nickel sheets, and NTCs. The PCBA rigid board is electrically connected to two FPC flexible boards. Nickel sheets are fixedly attached to the other end surfaces of the two FPC flexible boards. NTCs are spaced apart on the surface of the FPC flexible boards. The battery cell assembly is attached to the surface of the FPC flexible board parallel to the length direction of the bottom shell. The tabs of the battery cell assembly correspond to the nickel sheets. The nickel sheets are resistively welded to the positive and negative tabs of the corresponding battery cell assembly. The battery cell assembly is embedded in the bracket.

[0008] Furthermore, the bottom shell has a push button mounting groove at the rear, in which a push button and a spring are installed. The push button is elastically connected to the bottom shell through the spring. The inner wall of the push button mounting groove has a connecting groove, in which a bearing is installed. The push button is connected to the bearing.

[0009] Furthermore, the support surface is provided with a cell positioning groove, the cell assembly is embedded in the cell positioning groove, and the outer wall of the cell positioning groove is provided with reinforcing ribs.

[0010] Furthermore, along the length of the bottom shell, a mounting part is provided at the bottom near the end of the metal spring, and the mounting part is interference-fitted with the groove of the end cover.

[0011] Furthermore, a welding window is provided at the corresponding position between the FPC flexible board and the nickel sheet.

[0012] Furthermore, the bottom shell has ventilation holes on its side wall, and the support has support ventilation holes at positions corresponding to the ventilation holes. A waterproof and breathable membrane is attached to the side of the support ventilation holes closest to the bottom shell.

[0013] Furthermore, PC insulating sheets are assembled at both ends of the battery cell assembly along the length direction. The shape and size of the PC insulating sheets match the shape and size of the ends of the battery cell assembly along the length direction. The PC insulating sheets are attached to the outside of the protection plate. PC insulation sheets include solid insulation sheets and hollow insulation sheets. Hollow insulation sheets have through holes inside, and solid insulation sheets are attached to the outside of hollow insulation sheets.

[0014] Furthermore, a label is attached between the bracket and the bottom shell. The label is attached to the side away from the metal spring, and a label vent is provided at the position corresponding to the vent hole.

[0015] The above technical solution produces the following technical effects: 1. The waterproof ultrasonic groove of the bottom shell and the sealing structure of the top cover of the battery pack structure of this application adopt a shear-type ultrasonic welding design. During ultrasonic welding, a molecular-level sealing interface is formed. This structure can effectively prevent liquid intrusion. Combined with the high-strength fusion characteristics of ultrasonic welding, the leakage value can be kept within the IP68 standard. The end cover is interference-fitted with the bottom shell assembly part through the slot, which can eliminate the tail assembly gap and block the path of water vapor ingress from the end. The metal spring and metal nut are integrally formed with the bottom shell by the in-mold molding process, eliminating the gaps of traditional assembly and preventing water from entering the shell. The welding seal between the through hole of the protective plate and the metal spring blocks the path of water vapor ingress from the output interface, further improving the waterproof capability of the battery pack.

[0016] 2. The battery pack structure of this application adopts a shear-type ultrasonic welding structure with stronger tensile strength than ordinary welding structures. The outer shell assembly forms a rigid whole, and the outer shell assembly is not easy to crack during drop impact. The double fixation of the hook and slot structure of the top cover and the bottom shell and ultrasonic welding makes the impact force borne by the outer shell during drop impact distributed to the whole circumference, rather than stress concentration at a single connection point. The interference fit end cover can resist longitudinal impact and prevent the tail structure from loosening during drop, meeting the requirements of 2.8M drop and 2-wheel 6-sided roller 1M 4000-cycle test. Attached Figure Description

[0017] Figure 1 This is a front view of a battery pack structure according to the present invention; Figure 2 This is an exploded view of a battery pack structure according to the present invention; Figure 3 This is a partial detailed drawing of a battery pack structure according to the present invention; Figure 4 This is a detailed drawing of a battery pack structure FPC flexible circuit board according to this utility model.

[0018] In the picture: 1 - Battery cell assembly; 11 - PC insulating sheet; 111 - Solid insulating sheet; 112 - Hollow insulating sheet; 2 - Housing assembly; 21 - Top cover; 211 - Sealed structure; 212 - Hook; 22 - Bottom shell; 221 - Waterproof ultrasonic bath; 222-Hook and slot; 223 - Push button mounting slot; 2231 - Push button; 2232 - Spring; 2233 - Connecting slot; 2234 - Bearing; 224 – Assembly Department; 225 - Vent hole; 23 - End cap; 231 - Card slot; 3 - Output components; 31 - Metal shrapnel; 32 - Metal nut; 4 - Protective plate; 41-PCBA rigid board; 42-FPC flexible printed circuit board; 421 – Welding window; 43-Nickel sheet 5 - Support; 51 - Cell positioning slot; 511 - Reinforcing rib; 52 - Vent holes for the support; 53 - Waterproof and breathable membrane; 6 - Labels; 61 - Ventilation holes on the label. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figure 1-3This application provides a battery pack structure, including a cell assembly 1, a housing assembly 2, and an output assembly 3. The housing assembly 2 is a hollow structure, including an upper cover 21, a bottom shell 22, and an end cap 23. Waterproof ultrasonic grooves 221 are provided around the bottom shell 22. The upper cover 21 has a sealing structure 211 that cooperates with the waterproof ultrasonic grooves 221. Both the waterproof ultrasonic grooves 221 and the sealing structure 211 are ultrasonic welding shearing structures. The upper cover 21 and the bottom shell 22 are ultrasonically welded to the sealing structure 211 via the waterproof ultrasonic grooves 221. Furthermore, the bottom shell 22 has an assembly part 224 at its tail end near the metal spring 31 along its length. The assembly part 224 is interference-fitted with the slot 231 of the end cap 23. In this embodiment, the cell assembly 1 uses cylindrical 18650 cells, which can realize 1S2P and 2S1P combination schemes respectively. The cell assembly 1 is embedded in the housing assembly 2. The waterproof ultrasonic groove 221 of the bottom shell 22 and the sealing structure 211 of the top cover 21 adopt a shear-type fit, which is different from the traditional planar bonding. This structure has an interference fit design, which allows the material to fully melt in the groove during ultrasonic welding and form a closed weld layer. The full-circumference ultrasonic welding forms a continuous sealing ring without splicing gaps. Combined with the end cap 23 sealing the tail end of the bottom shell, the entire outer shell assembly 2 achieves an IP68 waterproof standard, avoiding short circuits of the battery cells or corrosion of the circuit. In addition, the top cover 21 and the bottom shell 22 form a rigid whole through the ultrasonic welding shear-type structure, making the outer shell less likely to disintegrate in the event of a drop, preventing the internal battery cell assembly 1 from directly colliding with hard objects.

[0021] It should be noted that the battery pack structure of this application is applied to handheld devices, which may specifically be smartphones, PDAs, handheld game consoles, handheld computers, etc.

[0022] Furthermore, the top cover 21 is provided with hooks 212, which are evenly distributed around the top cover 21. The bottom shell 22 is provided with the same number of hook slots 222 at the corresponding positions of the hooks 212. This design disperses the impact force borne by the shell during a drop collision to the entire circumference, rather than stress concentration at a single connection point, thereby improving the drop resistance. The output component 3 includes a metal spring 31 and a metal nut 32. The metal spring 31 and the metal nut 32 are integrally formed and connected to the bottom shell 22, further improving the waterproof capability of the battery pack.

[0023] Preferably, the bottom shell 22 has a push button mounting groove 223 at its tail. A push button 2231 and a spring 2232 are installed in the push button mounting groove 223. The push button 2231 is elastically connected to the bottom shell 22 via the spring 2232. A connecting groove 2233 is provided on the inner wall of the push button mounting groove 2233, and a bearing 2234 is installed in the connecting groove 2233. The push button 2231 is connected to the bearing 2234. When the battery cell assembly 1 needs to be replaced, the push button 2231 is pressed to compress the spring 2232, causing it to move inward along the bearing 2234. The push button 2231 disengages from the push button mounting groove 223, allowing the battery cell assembly 1 to be easily removed and replaced from the outer shell assembly 2. After replacement, the spring 2232 rebounds, pushing the push button 2231 back to its original position and engaging with the push button mounting groove 223, thus locking the battery pack. Compared to traditional screw-fixed or snap-fit ​​designs, this structure requires no tools and can be disassembled and assembled with one hand, making it much easier to operate.

[0024] This embodiment also includes a protection plate 4 and a bracket 5. The protection plate 4 is fixed inside the bottom shell 22. The protection plate 4 is provided with through holes 45. The through holes 45 are matched with the size and shape of the metal springs 31. The through holes 45 pass through the metal springs 31 one by one and are welded. The protection plate 4 includes a PCBA rigid board 41, an FPC flexible board 42, a nickel sheet 43, and an NTC 44. In this embodiment, the FPC flexible board 42 is equipped with two NTCs, which can more accurately detect the temperature of the battery cell and provide the device with temperature data in a timely and accurate manner. When the battery cell assembly 1 reaches the set temperature, the device automatically shuts down and cuts off the current. When the temperature exceeds the operating temperature of the battery cell assembly 1, the temperature protection is activated, which greatly improves the safety factor of the battery pack.

[0025] The PCBA rigid board 41 is electrically connected to two FPC flexible boards 42. Nickel sheets 43 are fixedly attached to the other ends of the two FPC flexible boards 42. NTC 44s are spaced apart on the surface of the FPC flexible boards 42. The battery cell assembly 1 is attached to the surface of the FPC flexible board 42 parallel to the length direction of the bottom shell 22. The tabs of the battery cell assembly 1 correspond to the nickel sheets 43. A welding window 421 is opened at the corresponding position between the FPC flexible board 42 and the nickel sheets 43. The nickel sheets 43 are resistance welded to the corresponding positive and negative tabs of the battery cell assembly 1. The battery cell assembly 1 is embedded in the bracket 5. The bracket 5 is fixed to the inside of the bottom shell 22 by silicone around its perimeter. When the battery pack is dropped, the silicone around the bottom shell 22 can absorb the impact energy through compression deformation, preventing the impact from being directly transmitted to the bracket 5 and the battery cell assembly 1 embedded inside. Compared to rigid fixing such as screw locking, silicone can significantly reduce the impact force, reducing the risk of tab breakage and separator damage to the battery cell assembly 1 due to severe impact.

[0026] Furthermore, the support 5 has a cell positioning groove 51 on its surface, and the cell assembly 1 is embedded in the cell positioning groove 51. The outer wall of the cell positioning groove 51 has reinforcing ribs 511. The size of the cell positioning groove 51 is precisely matched to the shape and size of the cell assembly 1. The embedded design can form a holistic enclosure and restraint for the cell assembly from all sides. During the battery pack assembly process, the cell assembly can be quickly positioned to the preset position, avoiding positional deviations that may occur during manual assembly. This ensures that the electrode tabs of the cell can be precisely aligned with the nickel sheet 43 on the protection plate 4, providing a stable foundation for subsequent resistance welding. The reinforcing ribs 511 are distributed along the outer wall of the cell positioning groove 51, which can significantly improve the bending and torsional strength of the support 5. When the battery pack is dropped or collided, such as when the equipment falls from a height of 1.5 meters, the impact energy will first act on the support. The reinforcing ribs can disperse the energy to the entire support through their own structure, preventing the support from bending, breaking, or other deformations.

[0027] Furthermore, the bottom shell 22 has vents 225 on its side wall, and the bracket 5 has bracket vents 52 at positions corresponding to the vents 225. A waterproof and breathable membrane 53 is attached to the side of the bracket vents 52 closest to the bottom shell 22. During charge and discharge cycles, the battery cell assembly 1 generates trace amounts of gas due to chemical reactions. Simultaneously, temperature changes inside the battery pack cause thermal expansion and contraction of the air, leading to internal pressure fluctuations. The vents 225 of the bottom shell 22 and the bracket vents 52 of the bracket 5 form an airflow channel, enabling bidirectional airflow between the inside and outside of the battery pack: when the internal pressure increases, excess gas is discharged through the vents; when the internal pressure decreases, external air is replenished through the vents, thus stabilizing the internal pressure at near atmospheric pressure. This design avoids the risk of deformation of the outer shell components due to excessively high pressure or the risk of external moisture entering the interior due to excessively low pressure, further ensuring the structural integrity of the battery pack.

[0028] Preferably, PC insulating sheets 11 are assembled at both ends of the battery cell assembly 1 along its length. The shape and size of the PC insulating sheets 11 match the shape and size of the ends of the battery cell assembly 1 along its length. The PC insulating sheets 11 are attached to the outside of the protection board 4. The PC insulating sheets 11 include solid insulating sheets 111 and hollow insulating sheets 112. The hollow insulating sheets 112 have through holes inside, and the solid insulating sheets 111 are attached to the outside of the hollow insulating sheets 112. The PCBA rigid board 41, FPC flexible board 42, and nickel sheet 43 on the protection board are all conductive components. Although the battery cell shell is insulated, the end tabs are made of metal. If they come into direct contact with the components of the protection board, they are prone to short circuits due to vibration and deformation. The PC insulating sheets 11 can effectively prevent the battery cell tabs from directly contacting the metal components of the protection board, greatly reducing the risk of short circuits. In addition, there may be tiny metal debris or dust inside the battery pack. The PC insulating sheet 11 covers and seals the battery pack completely, preventing impurities from entering the gap between the end of the battery cell assembly 1 and the protection board 4, thus avoiding local leakage or abnormal self-discharge of the battery cell assembly 1 caused by impurities.

[0029] Preferably, a label 6 is also attached between the bracket 5 and the bottom shell 22. The label 6 is attached to the side away from the metal spring 31, and a label vent 61 is provided at the position corresponding to the vent 225. The label 6, attached to the side away from the metal spring 31, can cover the gap between the bracket 5 and the bottom shell 22, preventing external dust and moisture from entering from this area and avoiding internal components from getting damp and accumulating dust. At the same time, the surface of the label 6 can protect the inner wall of the bottom shell 22, reduce wear caused by long-term vibration of the bracket 5, and extend the service life of the bottom shell 22. In some embodiments, the label 6 can also be printed with battery parameters such as capacity, voltage, and safety warnings, serving as an information labeling function and improving user convenience. In some embodiments, an insulating sheet is also attached to the side of the bracket 5 near the metal spring contact 31 between the bracket 5 and the bottom shell 22. The metal spring contact 31 serves as the power supply interface between the battery pack and the device and is in a continuously energized state. If the metal spring contact 31 comes into contact with non-conductive components such as the inner wall of the bottom shell 22 or the bracket 5 due to vibration or assembly deviation, leakage or short circuit may easily occur. The insulating sheet 7 can physically block this conductive path to ensure a safe and stable power supply process.

[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A battery pack structure, characterized in that, The device includes a battery cell assembly (1), a housing assembly (2), and an output assembly (3). The housing assembly (2) is a hollow structure, including an upper cover (21), a bottom shell (22), and an end cap (23). The bottom shell (22) is provided with a waterproof ultrasonic groove (221) around its perimeter. The upper cover (21) is provided with a sealing structure (211) that cooperates with the waterproof ultrasonic groove (221). Both the waterproof ultrasonic groove (221) and the sealing structure (211) are ultrasonic welding and shearing type structures. The upper cover (21) and the bottom shell (22) are ultrasonically welded to the sealing structure (211) through the waterproof ultrasonic groove (221). The end cover (23) is assembled on the tail end of the bottom shell (22) along the length direction near the output component (3). The battery cell assembly (1) is embedded in the outer shell assembly (2).

2. The battery pack structure according to claim 1, characterized in that, The upper cover (21) is provided with hooks (212), which are evenly distributed around the upper cover (21). The bottom shell (22) is provided with the same number of hook slots (222) at the positions corresponding to the hooks (212). The output component (3) includes a metal spring (31) and a metal nut (32), which are integrally formed and connected to the bottom shell (22).

3. The battery pack structure according to claim 2, characterized in that, It also includes a protective plate (4) and a bracket (5). The protective plate (4) is fixed inside the bottom shell (22). The protective plate (4) has through holes (45). The through holes (45) match the size and shape of the metal springs (31). The through holes (45) pass through the metal springs (31) one by one and are welded. The bracket (5) is fixed inside the bottom shell (22) by silicone around the bottom shell (22). The protection board (4) includes a PCBA rigid board (41), an FPC flexible board (42), a nickel sheet (43), and an NTC (44). The PCBA rigid board (41) is electrically connected to two FPC flexible boards (42). The nickel sheet (43) is attached to the other end surface of the two FPC flexible boards (42). The NTC (44) is spaced apart on the surface of the FPC flexible board (42). The battery cell assembly (1) is attached to the surface of the FPC flexible board (42) parallel to the length direction of the bottom shell (22). The tabs of the battery cell assembly (1) correspond to the nickel sheet (43). The nickel sheet (43) is resistively welded to the positive and negative tabs of the corresponding battery cell assembly (1). The battery cell assembly (1) is embedded in the bracket (5).

4. The battery pack structure according to claim 1, characterized in that, The bottom shell (22) is provided with a push button mounting groove (223) at the tail end. A push button (2231) and a spring (2232) are installed in the push button mounting groove (223). The push button (2231) is elastically connected to the bottom shell (22) through the spring (2232). A connecting groove (2233) is provided on the inner wall of the push button mounting groove (2233). A bearing (2234) is installed in the connecting groove (2233). The push button (2231) is connected to the bearing (2234).

5. A battery pack structure according to claim 3, characterized in that, The bracket (5) has a cell positioning groove (51) on its surface, and the cell assembly (1) is embedded in the cell positioning groove (51). The outer wall of the cell positioning groove (51) is provided with reinforcing ribs (511).

6. A battery pack structure according to claim 2, characterized in that, Along the length direction, the bottom of the bottom shell (22) near the end of the metal spring (31) is provided with an assembly part (224), and the assembly part (224) is interference-fitted with the slot (231) of the end cover (23).

7. A battery pack structure according to claim 3, characterized in that, A welding window (421) is provided at the corresponding position between the FPC flexible board (42) and the nickel sheet (43).

8. A battery pack structure according to claim 3, characterized in that, The bottom shell (22) has a vent hole (225) on its side wall, and the bracket (5) has a bracket vent hole (52) at a position corresponding to the vent hole (225). The bracket vent hole (52) has a waterproof and breathable membrane (53) attached to the side of the bracket vent hole (52) near the bottom shell (22).

9. A battery pack structure according to claim 3, characterized in that, The battery cell assembly (1) is equipped with PC insulating sheets (11) at both ends along the length direction. The shape and size of the PC insulating sheets (11) match the shape and size of the ends of the battery cell assembly (1) along the length direction. The PC insulating sheets (11) are attached to the outside of the protective plate (4). The PC insulating sheet (11) includes a solid insulating sheet (111) and a hollow insulating sheet (112). The hollow insulating sheet (112) has a through hole inside, and the solid insulating sheet (111) is attached to the outside of the hollow insulating sheet (112).

10. A battery pack structure according to claim 8, characterized in that, A label (6) is also attached between the bracket (5) and the bottom shell (22). The label (6) is attached to the side away from the metal spring (31). The label (6) has a label vent hole (61) at the position corresponding to the vent hole (225).

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