Power battery pack module of electric automobile

Abstract

The utility model discloses a power battery pack module of an electric automobile, which relates to the technical field of battery packs and comprises a battery cell, a module supporting structural member and a lower box body, the lower box body is fixedly connected with the module supporting structural member, the module supporting structural member comprises a frame, a longitudinal beam and a middle cross beam, and the longitudinal beam and the middle cross beam are connected in the frame. The interior of the frame is divided into a plurality of accommodating cavities for placing battery cells through longitudinal beams and middle cross beams, the battery cells are encircled into a whole by the module supporting structural member to form a battery cell module, the module supporting structural member is provided with two middle cross beams which are arranged at intervals, the middle cross beams are fixed with the lower box body through fasteners, and the fasteners do not penetrate through the battery cell module. The electric vehicle battery pack solves the problem that an existing electric vehicle battery pack is poor in sealing performance.

Description

Technical Field

[0001] The utility model relates to the technical field of battery packs, in particular to a power battery pack module for electric vehicles. Background Art

[0002] In the field of electric vehicles, the battery pack, as the core of the power system, its design and assembly are directly related to the performance, safety and endurance of the vehicle. The current electric vehicle battery packs mainly include box body mechanical structure parts, battery modules and battery management systems. The box body mechanical structure parts include an upper cover, a lower box body and module support structure parts, which jointly provide a stable support and protection for the battery modules. Among them, the lower box body, as the bottom foundation of the battery pack, bears all the components above, and the battery cell module is arranged inside the box body. Through precise structural design, while ensuring the efficient use of space, it also guarantees the stability and safety of the battery system. The battery cell module includes battery cells, module mechanical support structures, insulating parts, conductive carriers and signal acquisition carriers. The role of the battery cells is to store and release electrical energy, and they are arranged in series or parallel in the module.

[0003] For an existing electric vehicle battery pack, its module mechanical support structure includes a frame composed of front and rear end plates, an intermediate cross beam, two L-shaped beams on both sides and an intermediate T-shaped beam, whose function is to connect all the series or parallel battery cells into a whole, and fix the battery cells to the lower box body through bolts. In order to fix the battery cells more effectively, two stable lifting point columns are designed and installed on the lower box body. At the same time, through holes matching these lifting point columns are precisely opened on the intermediate T-shaped beam to ensure that the lifting point columns can accurately pass through the corresponding through holes, thus penetrating the entire battery pack structure. In order to further enhance the connection strength between the intermediate T-shaped beam and the box body, a special T-shaped beam pressing plate needs to be installed on the T-shaped beam. When the bolts are firmly tightened, the T-shaped beam pressing plate will closely fit the T-shaped beam and the box body. Through this pressing method, the T-shaped beam is effectively fixed to the box body, and further provides a more reliable and stable support for the battery cells.

[0004] The battery pack with the above structure has the problem of poor sealing, because the lifting point columns penetrate the entire battery pack, and its sealing depends on the cooperation of the upper cover compression nut and the sealing ring. However, this sealing method has extremely high requirements for the machining accuracy and installation accuracy of parts. Once there are slight deviations, the risk of poor sealing may increase significantly. Specifically, if the sealing interfaces between the lifting point columns and the intermediate cross beam compression nut and the upper cover compression nut are not properly processed, leakage problems are very likely to occur, thus affecting the overall performance and safety of the battery pack. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a power battery pack module for electric vehicles, which can solve the problem of poor sealing existing in the existing electric vehicle battery packs.

[0006] To solve the above problems, the technical solution adopted by the present utility model is as follows: This electric vehicle power battery pack module includes battery cells, a module support structure member, and a lower box body. The lower box body is fixedly connected to the module support structure member. The module support structure member includes a frame, longitudinal beams, and intermediate cross beams connected within the frame. The interior of the frame is divided into a plurality of accommodation cavities for placing the battery cells by the longitudinal beams and the intermediate cross beams. The module support structure member encloses a plurality of the battery cells into an integrated battery cell module. The module support structure member has two spaced-apart intermediate cross beams. The intermediate cross beams and the lower box body are fixed by fasteners, and the fasteners do not penetrate the battery cell module; the lower box body is not provided with lifting point columns.

[0007] In the above technical solution of the electric vehicle power battery pack module, a more specific technical solution may further be: The intermediate cross beam is provided with an upper card slot and a lower card slot. The upper card slot is engaged with the longitudinal beam, and the lower card slot is engaged with the limiting rib of the lower box body.

[0008] In some possible implementation schemes, the module support structure member is a symmetric structure.

[0009] In some possible implementation schemes, the frame includes end plates and side plates. The outer side surface of the end plate is provided with reinforcing ribs, and the upper edge of the side plate is provided with an inner pressing edge.

[0010] In some possible implementation schemes, the height of the intermediate cross beam is greater than the height of the longitudinal beam, and a heat dissipation space is provided between the longitudinal beam and the lower box body.

[0011] In some possible implementation schemes, the intermediate cross beam is a double-layer hollow profile.

[0012] Due to the adoption of the above technical solution, the present utility model has the following beneficial effects compared with the prior art:

[0013] 1. The present utility model cancels the design of the lifting point columns and their related compression nuts, fundamentally eliminating the sealing problems caused by penetrating parts. At the same time, by introducing two spaced-apart intermediate cross beams and using fasteners that do not penetrate the battery cell module to fix to the lower box body, a more reliable sealing system is constructed. This not only simplifies the sealing structure, reduces the requirements for part processing and installation accuracy, but also significantly improves the sealing performance of the battery pack, effectively preventing the intrusion of external pollutants such as moisture and dust; by increasing the number of intermediate cross beams, the stability of the module support structure member is further enhanced, and the overall stiffness of the battery pack is improved. This not only helps to resist vibrations and impacts during driving but also ensures that the battery pack can still maintain sufficient structural strength after canceling the lifting point columns, providing a strong guarantee for the safe operation of electric vehicles.

[0014] 2. The middle crossbeam is tightly fitted with the longitudinal beam and the lower box body through the upper and lower clamping grooves respectively, realizing the stable connection of the internal structure of the battery pack and improving the assembly efficiency.

[0015] 3. The module support structure is symmetrically designed, and the forces on both sides can balance each other, reducing the stress concentration and deformation risk caused by uneven stress, thereby enhancing the structural stability of the entire battery pack.

[0016] 4. The structure of the frame reduces the use of unnecessary materials and costs compared with the existing frame; the stiffness of the end plate is increased through the design of the reinforcing ribs, and the inner pressure edge design of the side plate can directly act on the edge of the battery cell, providing an additional pressing force to ensure that the battery cell is firmly fixed inside the battery pack, thereby enhancing the overall stability and safety of the battery pack.

[0017] 5. The height design of the middle crossbeam creates a large heat dissipation space between the lower box body and the longitudinal beam. This space provides more heat dissipation channels for the heat inside the battery pack, enabling the heat to be transferred more effectively from the inside of the battery pack to the external environment, reducing the operating temperature of the battery pack, and extending the service life of the battery cell.

[0018] 6. The structure of the double-layer hollow profile of the middle crossbeam can reduce the overall weight while still maintaining sufficient load-bearing capacity and anti-deformation ability; it can also improve the heat dissipation efficiency and reduce the operating temperature of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the module of the power battery pack of this electric vehicle.

[0020] Figure 2 It is a schematic structural diagram of the module support structure.

[0021] Figure 3 It is a schematic structural diagram of the middle crossbeam.

[0022] Figure 4 It is a schematic structural diagram of the lower box body.

[0023] Description of the reference numerals in the drawings: 1. Lower box body; 2. Module support structure; 3. Battery cell; 4. End plate; 5. Side plate; 6. Longitudinal beam; 7. Pressing plate; 8. Middle crossbeam; 9. Upper clamping groove; 10. Lower clamping groove; 11. Limit rib. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following further details the present utility model in conjunction with the embodiments of the drawings:

[0025] Figure 1The shown electric vehicle power battery pack module includes a lower box body 1, a module support structure member 2, battery cells 3, and an upper cover (not shown in the figure). Among them, the module support structure member 2 is the core framework of the module. A plurality of neatly arranged battery cells 3 are enclosed by the module support structure member 2 to form a whole battery cell module. The module support structure member 2 is fixed in the lower box body 1 through fasteners, and the upper cover and the lower box body 1 are covered to obtain the battery pack. To improve the sealing yield of the battery pack module, the present utility model abandons the lifting point column design of the traditional lower box body 1 and its supporting parts and holes. At the same time, aiming at the possible problem of insufficient middle stiffness, the structures of the module support structure member 2 and the lower box body 1 are optimized and strengthened.

[0026] In some examples, as Figure 2 and Figure 3 shown, the module support structure member 2 is a symmetric structure. It includes a frame, multiple longitudinal beams 6, and two middle cross beams 8 arranged separately. The frame includes end plates 4 and side plates 5. Reinforcing ribs are provided on the outer side surface of the end plate 4, and an inner pressing edge for pressing the battery cells 3 is provided on the upper edge of the side plate 5. The longitudinal beams 6 are arranged along the length direction of the frame, and the middle cross beams 8 are perpendicular to the longitudinal beams 6. These longitudinal beams 6 are equidistantly installed on the middle cross beams 8, dividing the space inside the frame into multiple accommodation cavities designed specifically for the battery cells 3. The middle cross beam 8 adopts a double-layer hollow profile design to enhance its structural strength in the thickness direction. At the same time, its height is higher than that of the longitudinal beams. A sufficient distance is provided between the bottom edge of the longitudinal beam 6 and the lower box body 1 to form sufficient heat dissipation space, which helps to improve the heat dissipation performance of the battery pack. The middle cross beam 8 is not only firmly connected to the lower box body 1 through fasteners, but also is respectively engaged with the longitudinal beam 6 and the lower box body 1 for quick assembly. Specifically, an upper card slot 9 and a lower card slot 10 are respectively opened on the upper and lower sides of the middle cross beam 8. The upper card slot 9 is tightly engaged with the longitudinal beam 6, and the lower card slot 10 matches the limit rib 11 on the lower box body 1 to achieve precise positioning and stable connection. See Figure 4 . To fix the battery cells 3, the longitudinal beam 6 adopts a T-shaped beam structure. A pressing plate 7 and bolts are used to fix the T-shaped beam on the middle cross beam 8, and then the flange of the T-shaped beam can be used to press the battery cells 3 placed in the module support structure member 2. The middle cross beam 8, longitudinal beam 6, and frame of the module support structure member 2 are all fixed on the lower box body 1 through fasteners. The fasteners are designed not to penetrate the length of the battery cell module, thus maintaining good sealing performance. The fasteners can adopt fastening bolts.

[0027] During assembly, first install the two middle crossbeams 8 of the module support structure 2 onto the lower box body 1, aligning the installation positions of the middle crossbeams 8 with the corresponding bolt positions on the box body; then install the end plates 4 and side plates 5 onto the lower box body 1 and tighten them with bolts; next, arrange the battery cells 3 in the lower box body 1 and the frame; subsequently, install the longitudinal beams 6 on the middle crossbeams 8, fix the longitudinal beams 6 with pressing plates 7 and bolts, and press and fix the battery cells 3 in the predetermined positions; finally, cover the upper cover over the assembled battery cell module, and use bolts to tightly connect the upper cover to the lower box body 1 to complete the assembly of the entire battery pack module.

[0028] This electric vehicle power battery pack module not only simplifies the component composition and reduces the manufacturing cost, but also realizes an approximately 5% improvement in assembly efficiency. More importantly, it significantly reduces the failure rate of poor battery pack sealing from 5‰ to 0.1‰, greatly enhancing the reliability of the product.

[0029] The above examples only show several specific implementation manners of the present invention. Although the description is relatively specific and detailed, it should not be construed as a limitation on the protection scope of the present invention patent. It should be clear that for those of ordinary skill in the art, without departing from the core concept and basic principles of the present invention, various deformations and improvements can be made to the present invention. These deformations and improvements should all be regarded as belonging to the protection scope of the present invention.

Claims

1. An electric vehicle power battery pack module, comprising battery cells, a module support structure member, and a lower box body. The lower box body is fixedly connected to the module support structure member. The module support structure member includes a frame and longitudinal beams and intermediate cross beams connected within the frame. The interior of the frame is divided into a plurality of accommodation cavities for placing the battery cells by the longitudinal beams and the intermediate cross beams. The module support structure member encloses a plurality of the battery cells into an integrated battery cell module, and is characterized in that: The module support structure has two intermediate crossbeams that are separately arranged. The intermediate crossbeams are fixed to the lower box body by fasteners, and the fasteners do not penetrate the battery cell module.

2. The electric vehicle power battery pack module according to claim 1, wherein: The intermediate crossbeam is provided with an upper card slot and a lower card slot. The upper card slot is engaged with the longitudinal beam, and the lower card slot is engaged with the limiting rib of the lower box body.

3. The electric vehicle power battery pack module according to claim 2, characterized in that: The module support structure is a symmetric structure.

4. The electric vehicle power battery pack module according to claim 3, wherein: The frame includes end plates and side plates. Reinforcing ribs are provided on the outer side surface of the end plates, and an inner pressing edge is provided on the upper edge of the side plates.

5. The electric vehicle power battery pack module according to any one of claims 1 to 4, characterized in that: The height of the intermediate crossbeam is greater than the height of the longitudinal beam, and a heat dissipation space is provided between the longitudinal beam and the lower box body.

6. The electric vehicle power battery pack module according to claim 5, characterized in that: The intermediate crossbeam is a double-layer hollow profile.

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