Battery pack and assembly method thereof

Abstract

The invention provides a battery pack and an assembly method thereof, the battery pack comprises: a bottom tray, the upper end of which is fixedly connected with a middle box body; a first accommodating cavity for accommodating the battery module is formed in the lower side of the middle box body; a plurality of battery modules, the confluence structures of the battery modules are located at least one end of the battery modules in the horizontal direction, a part of the battery modules are fixedly connected to the upper side of the bottom tray, and the confluence structures of the part of the battery modules are located above the top of the bottom tray; the other part of the battery modules are fixedly connected to the upper side of the middle box body, and a confluence structure of the part of the battery modules is positioned above the top of the middle box body; the upper cover is fixedly connected to the upper end of the middle box body, and a second containing cavity is formed in the lower side of the upper cover and used for containing the battery module fixed to the upper side of the middle box body.

Description

Technical Field

[0001] This invention belongs to the field of battery pack technology, specifically relating to a battery pack and its assembly method. Background Technology

[0002] In the commercial vehicle sector, stacked battery packs have been successfully deployed on a large scale. These battery packs generally adopt a tall, box-shaped structure design, with the blade cells inside featuring a configuration with terminals at both ends. However, due to the space limitations of the tall box, the cells must be assembled using an inverted assembly process or with the aid of suction cups for positioning. This unique assembly method presents significant drawbacks. Once the battery cells are installed and secured in the casing, the accessibility and operability of the integrated flexible printed circuit board (FPC) and voltage acquisition module decrease dramatically, making effective maintenance difficult. This issue has a dual negative impact: firstly, it directly reduces the yield rate in the production process; secondly, the difficulties in subsequent maintenance indirectly increase after-sales costs. Ultimately, this situation becomes a key factor restricting the overall efficiency improvement of this battery pack solution. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a battery pack and its assembly method. The structural design of the battery pack enables the battery module to be connected to the bottom tray and the top of the middle box, thereby improving the operability and convenience of blade battery module maintenance.

[0004] To address the aforementioned technical problems, the first aspect of this application provides a battery pack, comprising: The bottom tray is fixedly connected to the middle box at the top. The middle housing has a first receiving cavity on the lower side for accommodating the battery module; A plurality of battery modules, wherein the busbar structure of the battery modules is located at at least one end of the battery modules in the horizontal direction, a portion of the battery modules are fixedly connected to the upper side of the bottom tray, and the busbar structure of the portion of the battery modules is located above the top of the bottom tray; another portion of the battery modules are fixedly connected to the upper side of the intermediate housing, and the busbar structure of the portion of the battery modules is located above the top of the intermediate housing. The top cover is fixedly connected to the upper end of the intermediate box. The lower side of the top cover is provided with a second receiving cavity for accommodating the battery module fixed to the upper side of the intermediate box.

[0005] Furthermore, the upper side of the intermediate housing is provided with a mounting groove, the mounting groove including at least two end plates spaced apart along the length of the battery pack, the end plates being used to mechanically constrain the two sides of the battery module.

[0006] Furthermore, there are multiple intermediate boxes, which are stacked vertically and fixedly connected. The bottom intermediate box is fixedly connected to the top of the bottom tray, and the top cover is fixedly connected to the top of the top intermediate box.

[0007] Furthermore, the intermediate housing includes a rectangular frame structure with the first accommodating cavity, and the rectangular frame structure has a support plate for supporting the battery module inside, the support plate being a liquid cooling plate.

[0008] Furthermore, a wire-passing hole is provided between the rectangular frame structure and the support plate.

[0009] Furthermore, the bottom tray has a mounting groove on its upper side, the mounting groove including at least two end plates spaced apart along the length of the battery pack, the end plates being used to mechanically constrain the two sides of the battery module.

[0010] Furthermore, the bottom tray includes a frame and a base plate connected within the frame, the base plate being a liquid-cooled plate.

[0011] Furthermore, the bottom tray, the intermediate boxes, and the top cover are all provided with coaxial and longitudinally penetrating through holes at their four corners, and a first connecting rod is connected in the through holes to enable the bottom tray, the multiple intermediate boxes, and the top cover to be detachably connected.

[0012] A second aspect of this application provides an assembly method based on a battery pack as described in any of the above claims, comprising the following steps: Several battery modules are installed in two parts, one part is fixedly connected to the mounting slot of the bottom tray, and the other part is installed in the mounting slot of the middle box; and the busbar structure of the battery module installed on the upper side of the bottom tray protrudes from the top of the bottom tray, and the busbar structure of the battery module installed on the upper side of the middle box protrudes from the top of the middle box. Multiple intermediate boxes are stacked sequentially, so that the bottom intermediate box is fitted onto the battery module on the upper side of the base tray, and the lower end of the bottom intermediate box is fixedly connected to the base tray; adjacent intermediate boxes are fixedly connected, and the upper intermediate box is fitted onto the battery module on the lower intermediate box. The top cover is fitted onto the outside of the battery module on the top middle box, and the lower end of the top cover is fixedly connected to the top middle box. A first connecting rod is used to sequentially pass through the top cover, multiple intermediate boxes, and the bottom tray. Fasteners are applied to both ends or one end of the first connecting rod and tightened to make the top cover, multiple intermediate boxes, and the bottom tray a single unit.

[0013] Furthermore, during the process of stacking and fixing multiple intermediate boxes in sequence, high-voltage wire harnesses are used to pass through the corresponding wiring holes in adjacent intermediate boxes to achieve circuit connection between the battery modules installed in adjacent intermediate boxes.

[0014] Compared with the prior art, the beneficial effects of this application are: 1. The battery module of this application is fixed to the bottom tray and the top of the middle box, and the bottom tray, the middle box, and the top cover are all detachably connected. When the battery module malfunctions, the middle box or the top cover on the battery module can be removed to expose the terminal post structure at the end of the battery module, providing convenient operating space for repairing the terminal post structure at both ends of the battery module, greatly improving the repair efficiency of the battery module, saving repair time, and reducing after-sales costs.

[0015] 2. The rectangular frame structure of this application has vertically oriented wiring holes on its inner side, allowing high-voltage wiring harnesses to pass through and connect the blade battery module to the vehicle's power system. This structure directly reduces the use of internal wiring harnesses, saves on high-voltage connectors and internal copper busbars, and lowers costs.

[0016] 3. When the bottom tray and the intermediate housing of this application are stacked together, the battery modules on the bottom tray and the upper sides of the battery modules located on the lower intermediate housing abut against the lower side of the liquid cooling plate on the upper intermediate housing. This allows battery modules on different intermediate housings to share the liquid cooling plate for centralized cooling, achieving not only weight reduction but also significantly improving the battery pack's cooling capacity. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the battery pack structure of this application; Figure 2 This is a schematic diagram of the bottom tray structure of this application; Figure 3 This is a schematic diagram of the structure of the base of this application; Figure 4 This is a bottom view of the base of this application; Figure 5 This is a structural schematic diagram of the intermediate box body of this application; Figure 6 This is a bottom view of the rectangular frame structure of this application.

[0018] In the picture: 1. Bottom tray; 2. Middle box; 3. Top cover; 4. First connecting rod; 5. Second connecting rod; 6. Base; 7. Blade battery module; 8. Rectangular frame structure; 9. End plate; 10. Liquid cooling plate; 11. Liquid cooling water nozzle; 12. Wiring hole; 13. Maintenance window; 14. MSD. Detailed Implementation

[0019] To facilitate understanding of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] refer to Figures 1 to 2 As shown, this embodiment provides a battery pack, including: The bottom tray 1 is fixedly connected to the middle box 2 at its upper end; The middle housing 2 has a first receiving cavity on its lower side for accommodating the battery module 7; A plurality of battery modules 7, wherein the busbar structure of the battery modules 7 is located at at least one end of the battery modules 7 in the horizontal direction; a portion of the battery modules 7 are fixedly connected to the upper side of the bottom tray 1, and the busbar structure of this portion of the battery modules 7 is located above the top of the bottom tray 1; another portion of the battery modules 7 are fixedly connected to the upper side of the intermediate housing 2, and the busbar structure of this portion of the battery modules 7 is located above the top of the intermediate housing 2. The upper cover 3 is fixedly connected to the upper end of the intermediate box 2. The lower side of the upper cover 3 is provided with a second receiving cavity for accommodating the battery module 7 fixed to the upper side of the intermediate box 2.

[0021] In existing technologies, battery packs adopt a box-type structure design. When the cell module is placed in the box, the side beams of the box will block the terminal structures at both ends of the cell module. When the cell module fails, it is difficult to repair the terminal structures at both ends of the cell module. This not only directly affects the yield rate in the production process, but also indirectly increases after-sales costs due to the difficulty of subsequent maintenance.

[0022] In this application, several battery modules 7 are respectively fixed to the top of the bottom tray 1 and the middle housing 2, and the terminal post structure at the end of the battery module 7 is located above the bottom tray 1 and the middle housing 2. The bottom tray 1, the middle housing 2, and the top cover 3 are all detachably connected. The first receiving cavity at the bottom of the middle housing 2 and the second receiving cavity at the bottom of the top cover 3 not only cover the outside of the battery module 7, providing protection for the battery module 7, but also do not interfere with the terminal post structure at the end of the battery module 7. When the battery module 7 malfunctions, the middle housing 2 or the top cover 3 on the battery module 7 can be removed, exposing the terminal post structure at both ends of the battery module 7. This provides convenient operating space for repairing the terminal post structure at the end of the battery module 7, greatly improving the repair efficiency of the battery module 7, saving repair time, and reducing after-sales costs.

[0023] refer to Figure 5 As shown, in some embodiments, the upper side of the intermediate housing 2 is provided with a mounting groove, which includes at least two end plates 9 spaced apart along the length of the battery pack. The end plates 9 are used to mechanically constrain the two sides of the battery module 7. Preferably, there are three end plates 9, dividing the mounting groove into two mounting areas. The battery module 7 is arranged in the mounting groove along the width direction of the battery pack and extends along the length direction of the battery pack, such that the busbar structure at the end of the battery module 7 is located at the openings on both sides of the mounting groove. In this embodiment, the busbar structure at the end of the battery module 7 is the terminal post structure of the battery module 7.

[0024] In some embodiments, there are multiple intermediate boxes 2, which are stacked vertically and fixedly connected. The bottom intermediate box 2 is fixedly connected to the upper side of the bottom tray 1, and the top cover 3 is fixedly connected to the upper side of the top intermediate box 2. Specifically, the number of intermediate boxes 2 can be selected according to actual needs.

[0025] refer to Figure 6 As shown, in some embodiments, the intermediate housing 2 includes a rectangular frame structure 8 with the first accommodating cavity. The rectangular frame structure 8 has a support plate inside for supporting the battery module 7, and the support plate is a liquid cooling plate 10. The liquid cooling plate 10 is thermally connected to the battery module 7 on its upper side.

[0026] refer to Figure 2 As shown, in some embodiments, the bottom tray 1 has a mounting groove on its upper side. The mounting groove includes at least two end plates 9 spaced apart along the length of the battery pack. The end plates 9 are used to mechanically constrain the two sides of the battery module 7. Preferably, there are three end plates 9, dividing the mounting groove into two mounting areas. The battery module 7 is arranged in the mounting groove along the width of the battery pack and extends along the length of the battery pack, such that the terminal post structure at the end of the battery module 7 is located at the openings on both sides of the mounting groove.

[0027] refer to Figure 3 As shown, the bottom tray 1 includes a frame and a base plate connected within the frame, the base plate being a liquid cooling plate 10. The liquid cooling plate 10 is thermally connected to the battery module 7 on its upper side. There are several options for the specific connection method between the liquid cooling plate 10 and the battery module 7; for example, the battery module 7 can be bonded to the liquid cooling plate 10 using thermally conductive structural adhesive.

[0028] In some embodiments, when the bottom tray 1 and multiple intermediate housings 2 are stacked together, the battery module 7 on the bottom tray 1 is thermally connected to the liquid cooling plate 10 in the intermediate housing 2 above it, and the battery module 7 on the lower intermediate housing 2 is thermally connected to the liquid cooling plate 10 on the intermediate housing 2 above it. The battery modules 7 on these different intermediate housings 2 can share the liquid cooling plate 10 for centralized cooling, achieving not only weight reduction but also significantly improving the battery pack's cooling capacity.

[0029] refer to Figure 5 As shown, in some embodiments, the rectangular frame structure 8 includes a side plate and an end plate. The outer side of the end plate is provided with a liquid cooling water nozzle 11, an MSD 14 and a maintenance window 13. The liquid cooling water nozzle 11 is connected to the liquid cooling plate 10.

[0030] In some embodiments, the top cover 3 is a box-shaped structure with a narrow top and a wide bottom opening, and it is made of composite materials. This achieves weight reduction of the overall battery pack while further controlling costs.

[0031] refer to Figure 6 As shown, in some embodiments, a wire-passing hole 12 is provided between the frame and the base plate of the bottom tray 1, and a wire-passing hole 12 is provided between the rectangular frame structure 8 and the support plate, with the wire-passing hole 12 extending vertically, through which a high-voltage wiring harness for connecting the battery module 7 to the vehicle power system is installed. This structural design allows for vertical wiring of the high-voltage wiring harness inside the battery pack, replacing the traditional copper busbar connection method, reducing the number of high-voltage plugs and internal copper busbars, lowering material costs and assembly complexity, while improving system reliability.

[0032] In the above embodiments, the specific structural form of the wire hole 12 can be set according to actual needs. For example, the shape of the wire hole 12 can be circular, square, or rectangular. The edges of the wire hole 12 are provided with a rounded corner structure, and a rubber protective sleeve can be optionally provided to prevent damage to the wire harness insulation layer. A wire harness fixing bracket is also provided near the wire hole 12 to secure the high-voltage wire harness to the frame structure by cable ties or clips, preventing the wire harness from shaking during vehicle operation.

[0033] refer to Figure 1 As shown, in some embodiments, the bottom tray 1, the multiple intermediate boxes 2 and the top cover 3 are provided with coaxial and longitudinally penetrating through holes at the four corners, and a first connecting rod 4 is connected in the through holes to realize the detachable connection of the bottom tray 1, the multiple intermediate boxes 2 and the top cover 3.

[0034] Preferably, the first connecting rod 4 is a lifting rod. The through holes at the four corners of the bottom tray 1, multiple intermediate boxes 2, and the top cover 3 provide installation channels for the lifting rod, ensuring accurate axial positioning of the lifting rod. The lifting rod is detachably installed in the through holes and can be removed after hoisting without affecting the normal use of the battery pack. It also eliminates the need for special tools, facilitating operation in outdoor maintenance and other scenarios. The lifting rod includes a lifting ring and a rod body connected to the lifting ring. The lifting ring is directly connected to a hook or strap, eliminating the reliance on special hoisting tools and simplifying the hoisting connection steps.

[0035] refer to Figure 1 As shown, in some embodiments, the bottom tray 1, the multiple intermediate boxes 2 and the top cover 3 are provided with coaxial and longitudinally penetrating connecting holes on both sides, and a second connecting rod 5 is connected in the connecting holes to realize the detachable connection of the bottom tray 1, the multiple intermediate boxes 2 and the top cover 3.

[0036] Preferably, the first connecting rod 4 is a long screw rod with a nut at the top and an external thread at the bottom. The nut at the top is engaged with the upper side of the connecting hole in the upper cover 3, and the external thread at the bottom passes downward through the connecting hole in the bottom tray 1 and is connected by a nut. This connection method is stable and reliable, effectively withstanding vibrations and impacts during vehicle operation, ensuring the battery pack is securely installed. At the same time, the threaded connection facilitates later disassembly and maintenance, improving operational convenience.

[0037] This application also provides a battery pack assembly method, including the following steps: A portion of several battery modules 7 are fixedly connected in the mounting slot of the bottom tray 1, and another portion is installed in the mounting slot of the middle box 2. The busbar structure of the battery modules 7 on the upper side of the bottom tray 1 is located above the top of the bottom tray 1, and the busbar structure of the battery modules 7 on the upper side of the middle box 2 is located above the top of the middle box 2. The plurality of intermediate boxes 2 are stacked sequentially on the bottom tray 1, and the first receiving cavity at the bottom of the intermediate box 2 is respectively fitted onto the outside of the battery module 7 located below it; The top cover 3 is installed on the top intermediate box 2, and the second receiving cavity at the bottom of the top cover 3 is sleeved on the outside of the battery module 7 on the top intermediate box 2; The first connecting rod is installed in the through holes at the four corners of the bottom tray 1, the plurality of intermediate boxes 2 and the top cover 3 to achieve a detachable connection between the bottom tray 1, the plurality of intermediate boxes 2 and the top cover 3.

[0038] In some embodiments, the step of "stacking the plurality of intermediate housings 2 sequentially on the bottom tray 1" further includes: using a high-voltage wire harness to pass through the wiring holes on the bottom tray 1 and the plurality of intermediate housings 2 to connect the battery module 7 to the vehicle's power system.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this application as claimed. The scope of protection of this application is defined by the appended claims and their equivalents.

Claims

1. A battery pack, characterized by, The utility model relates to a battery pack, including: The bottom tray is fixedly connected with the upper end of the middle box body; The middle box body is provided with a first containing cavity on the lower side for containing the battery module; A plurality of battery modules, the bus structure of the battery module is located at least one end in the horizontal direction of the battery module, a part of the battery module is fixedly connected on the upper side of the bottom tray, and the bus structure of the battery module is located above the top of the bottom tray; another part of the battery module is fixedly connected on the upper side of the middle box body, and the bus structure of the battery module is located above the top of the middle box body; The upper cover is fixedly connected with the upper end of the middle box body, and the second containing cavity is arranged on the lower side of the upper cover for containing the battery module fixedly connected with the upper side of the middle box body.

2. The battery pack of claim 1, wherein, The upper side of the middle box body is provided with a mounting groove, and the mounting groove includes at least two end plates arranged at intervals along the length direction of the battery pack, and the end plates are used for mechanically restraining the two sides of the battery module.

3. The battery pack of claim 1, wherein, The number of the middle box bodies is multiple, the multiple middle box bodies are stacked and fixedly connected, the lowermost middle box body is fixedly connected on the upper side of the bottom tray, and the upper cover is fixedly connected on the upper side of the uppermost middle box body.

4. The battery pack of claim 3, wherein, The middle box body includes a rectangular frame structure provided with the first containing cavity, and the rectangular frame structure has a support plate inside for supporting the battery module, and the support plate is a liquid cooling plate.

5. The battery pack of claim 4, wherein, The rectangular frame structure and the support plate are provided with a threading hole.

6. The battery pack of claim 1, wherein, The upper side of the bottom tray is provided with a mounting groove, and the mounting groove includes at least two end plates arranged at intervals along the length direction of the battery pack, and the end plates are used for mechanically restraining the two sides of the battery module.

7. The battery pack of claim 1, wherein, The bottom tray includes a frame and a bottom plate connected in the frame, and the bottom plate is a liquid cooling plate.

8. The battery pack of claim 1, wherein, The four corners of the bottom tray, the middle box body and the upper cover are provided with through holes coaxial and longitudinally penetrating, and the first connecting rod is connected in the through hole to realize detachable connection of the bottom tray, the multiple middle box bodies and the upper cover.

9. A method of assembling a battery pack according to any one of claims 1-8, characterized by, The utility model relates to a battery pack, including: A plurality of battery modules are installed in two parts, one part is fixedly connected in the mounting groove of the bottom tray, and the other part is installed in the mounting groove of the middle box body; and the bus structure of the battery module installed on the upper side of the bottom tray protrudes from the top of the bottom tray, and the bus structure of the battery module installed on the upper side of the middle box body protrudes from the top of the middle box body; The multiple middle box bodies are sequentially stacked one above the other, so that the lowermost middle box body is sleeved outside the battery module on the upper side of the base tray, and the lower end of the lowermost middle box body is fixedly connected with the base tray; the adjacent two middle box bodies are fixedly connected, and the upper middle box body is sleeved outside the battery module on the lower middle box body; The upper cover is sleeved outside the battery module on the top middle box body, and the lower end of the upper cover is fixedly connected with the top middle box body; A first connecting rod is sequentially penetrated through the upper cover, the multiple middle box bodies and the bottom tray, a fastener is applied to the two ends or one end of the first connecting rod, and the upper cover, the multiple middle box bodies and the bottom tray are fastened as a whole.

10. The battery packaging method according to claim 9, wherein, In the process of stacking and fixedly connecting the plurality of intermediate boxes in sequence from top to bottom, the high-voltage wire harness is used to pass through the wire passing holes correspondingly arranged in the adjacent intermediate boxes, so as to realize the circuit communication between the battery modules installed in the adjacent intermediate boxes.

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