A strong sealing integrated liquid cooling lightweight battery box

Abstract

The application discloses a kind of strong sealing integrated liquid cooling lightweight battery box, including battery box and transverse beam structure, transverse beam structure is set in battery box;Battery box includes upper box type plate, lower box type plate and structural reinforcement side plate;Upper box type plate and lower box type plate are stacked nested in height direction, so that the bottom plate and side plate of battery box are formed into double-layer structure;And interlayer space is formed between upper box type plate and lower box type plate, cooling flow channel and structural reinforcement filler are arranged in the interlayer space;Structural reinforcement side plate extends along the length side and / or width side of battery box, and is connected to the outside of lower box type plate, so that the length side and / or width W side of battery box is three-layer structure;Transverse beam structure constitutes the inner support framework of battery box and partitioning is supported inwards.By box stacked nested double-layer structure integrated liquid cooling flow channel and reinforcement filler, realize lightweight, high strength and high sealing integrated battery box.

Description

Technical Field

[0001] This invention belongs to the field of battery box technology, and particularly relates to a highly sealed integrated liquid-cooled lightweight battery box. Background Technology

[0002] Current battery enclosures, designed to balance heat dissipation and load-bearing capacity, often employ a split structure. This involves a frame composed of horizontal and vertical beams, with an independent liquid cooling plate at the bottom, all then welded together. The problems include: the liquid cooling plate, as an independent component, increases the connection interface, introducing potential leakage channels, and resulting in numerous weld points and significant deformation, which is detrimental to sealing and weight reduction; the separation of function between the frame and the base plate necessitates increased wall thickness or the addition of reinforcing ribs to ensure strength, leading to increased weight; and the liquid cooling plate being located only at the bottom leaves the side walls and corners without effective thermal management or structural reinforcement, resulting in insufficient overall rigidity and protection, making it difficult to simultaneously meet the requirements of high sealing, high strength, and integrated thermal management while maintaining a lightweight design. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a strong-sealed integrated liquid-cooled lightweight battery box. By using a double-layer structure of stacked and nested boxes to integrate liquid-cooling channels and reinforcing fillers, a lightweight, high-strength and highly sealed integrated battery box is achieved.

[0004] Technical solution: To achieve the above objectives, the present invention provides a strong-sealed integrated liquid-cooled lightweight battery box, comprising a battery box body and a horizontal and vertical beam structure. The battery box body has a length L, a width W, and a height H. The horizontal and vertical beam structure is disposed within the battery box body. The battery box body includes an upper box-shaped plate, a lower box-shaped plate, and structurally reinforcing side plates.

[0005] The upper box-shaped plate and the lower box-shaped plate are stacked and nested in the height H direction, so that the bottom plate and side plate of the battery box body are both formed into a double-layer structure; and a sandwich space is formed between the upper box-shaped plate and the lower box-shaped plate, and a cooling channel and structural reinforcement filler are provided in the sandwich space;

[0006] The structurally reinforced side panel extends along the length L side and / or width W side of the battery box body and is connected to the outside of the lower box-shaped panel, so that the box panel on the length L side and / or width W side of the battery box body has a three-layer structure.

[0007] The horizontal and vertical beams are arranged in a crisscross pattern along the length L and width W of the battery box body, forming an internal support frame that provides internal support and partitions for the battery box body.

[0008] Furthermore, the thickness of the upper box-shaped plate is a, the thickness of the lower box-shaped plate is b, and the thickness of the structurally reinforcing side plate is c, wherein a < c and b < c.

[0009] Furthermore, a and b satisfy either a = b or a < b.

[0010] Furthermore, the interlayer space includes a water-cooled interlayer space and a filler interlayer space located at the bottom of the battery box body, as well as an inner interlayer space located on the side of the battery box body.

[0011] The water-cooled interlayer space is located below the battery pack installation area, and its coverage area is not less than the area of ​​the battery pack installation area. The cooling channel is formed in the water-cooled interlayer space.

[0012] The filler interlayer space is adjacent to the water-cooling interlayer space and is located at the bottom edge of the battery box body. The structural reinforcement filler is filled in the filler interlayer space.

[0013] The structurally reinforced side panel is disposed on the side of the battery box body and forms an outer interlayer space between it and the side wall of the lower box-shaped panel; the inner interlayer space is formed by the space between the side wall of the upper box-shaped panel and the side wall of the lower box-shaped panel, thereby making the side panel of the battery box body a three-layer panel structure with double interlayer.

[0014] Furthermore, the filler interlayer space, the structural reinforcement filler, and the three-layer plate structure formed by the inner interlayer space and the outer interlayer space are all located on the length L side of the battery box body.

[0015] Furthermore, the structurally reinforced side plate is a Z-shaped plate, with its lower end extending to the bottom of the lower box-shaped plate, forming a bottom support plate that supports the battery box body from the bottom along the length L side.

[0016] Furthermore, the structural reinforcement filler is a zigzag or corrugated structural plate.

[0017] Furthermore, the upper box-shaped plate and the lower box-shaped plate, as well as the battery box body and the horizontal and vertical beam structures, are respectively fixedly connected by welding.

[0018] Furthermore, the upper and lower box-shaped plates are connected by vacuum brazing to seal the cooling channels; the battery box body is connected to the transverse and longitudinal beam structures by friction stir welding.

[0019] Furthermore, the transverse and longitudinal beam structure includes longitudinal beams arranged along the length L direction of the battery box body, and transverse beams arranged along the width W direction of the battery box body.

[0020] Beneficial effects: This invention designs the casing as a double-layered structure with upper and lower nested layers. The interlayer space integrates cooling channels and structural reinforcement fillers, enabling the casing itself to possess thermal management and structural reinforcement functions. This eliminates the need for separate liquid cooling plates, reducing connection interfaces and leakage risks, and improving overall sealing reliability. The double-layered thin plates, compared to a single-layered thick plate of equal weight, have a larger moment of inertia, significantly enhancing bending and torsional stiffness. Combined with localized triple-layered plates and corrugated reinforcement fillers, higher structural load-bearing capacity and impact resistance are achieved while reducing overall weight. The bottom fully covered with channels ensures uniform cooling of the cells, while edge reinforcement and the double-layered sidewall structure precisely strengthen weak areas. The material distribution matches functional requirements, allowing the battery casing to simultaneously achieve lightweight, high strength, high sealing, and efficient thermal management. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the three-dimensional structure of the battery box body of the present invention. Figure 1 .

[0022] Figure 2 This is a schematic diagram of the three-dimensional structure of the battery box body of the present invention. Figure 2 .

[0023] Figure 3 This is a schematic diagram of the battery box body of the present invention in a cross-sectional view. Detailed Implementation

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] like Figure 1 , Figure 2 as well as Figure 3As shown, a strongly sealed integrated liquid-cooled lightweight battery box includes a battery box body 1 and a horizontal and vertical beam structure 8. The battery box body 1 has a length L, a width W and a height H, and the horizontal and vertical beam structure 8 is disposed inside the battery box body 1. The battery box body 1 includes an upper box-shaped plate 2, a lower box-shaped plate 3, and a structurally reinforcing side plate 4. The upper box-shaped plate 2 and the lower box-shaped plate 3 are stacked and nested in the height H direction, so that the bottom plate and side plate of the battery box body 1 are both formed as a double-layer structure. A sandwich space 5 is formed between the upper box-shaped plate 2 and the lower box-shaped plate 3. Cooling channels 6 and structurally reinforcing filler 7 are provided in the sandwich space 5. The structurally reinforcing side plate 4 extends along the length L side and / or width W side of the battery box body 1 and is connected to the outside of the lower box-shaped plate 3, so that the box plate on the length L side and / or width W side of the battery box body 1 is a three-layer structure. The transverse and longitudinal beam structure 8 is arranged in a crisscross pattern along the length L direction and the width W direction of the battery box body 1, forming an internal support skeleton for internal support and partitioning of the battery box body 1. This invention differs from the traditional battery box's modular structure, which involves separately manufacturing individual components such as the frame, liquid cooling plate, and base plate before assembling and welding them. Instead, it presents an integrated double-layer shell structure with unified structure and function. The key lies in the nested layering of the upper and lower box-shaped plates 2 and 3. Here, "layering" refers to the assembly and combination of the upper and lower box-shaped plates in the height direction, causing their base plate areas to overlap. "Nesting" refers to the mutually accommodating and constraining spatial relationship formed between the side walls of the upper and lower box-shaped plates, ultimately transforming the base plate and side plates of the box from single-layer plates into a double-layer plate structure. Therefore, based on this structural change, the advantages are:

[0026] I. Traditionally, increasing the stiffness of a single-layer thick plate requires increasing its thickness, leading to increased weight. This invention employs a double-layer thin-plate nested structure. With a total material usage equal to or even less than a single-layer thick plate, the increased moment of inertia between the two layers results in significantly higher overall bending and torsional stiffness compared to a single-layer structure of the same weight, achieving a breakthrough effect of lighter weight and higher strength. II. The interlayer space 5 formed by the double-layer structure is used as a functional integrated cavity. This invention directly arranges the cooling channel 6 within this interlayer space 5, making the bottom plate of the housing itself a liquid-cooled plate, completely eliminating the independent liquid-cooled plate component and its associated additional connection interfaces and leakage risks. The heat transfer path is: battery pack → thermally conductive adhesive → upper box-shaped plate → cooling channel, reducing thermal resistance and improving heat exchange efficiency. III. In the area within the interlayer space 5 not occupied by the channel, the thin walls of the upper and lower box-shaped plates, provided by the structural reinforcement filler 7, form internal supports, which can suppress local buckling of the thin walls under pressure, bending, or impact. Therefore, the mezzanine space 5 simultaneously accommodates the cooling medium and reinforcing materials, addressing both thermal management and structural reinforcement needs in a single space, demonstrating high space utilization and functional integration. Fourth, based on the double-layer structure, a structurally reinforced side plate 4 is added to the length and / or width sides of the enclosure, where lateral impact or bending causes the greatest stress. This, together with the existing upper and lower box-shaped sidewalls, forms a three-layer structure. This three-layer structure possesses stronger lateral bending resistance, effectively resisting side impact intrusion and lateral bending deformation of the enclosure, protecting the safety of the internal battery pack.

[0027] Therefore, this invention integrates liquid cooling channels and reinforcing fillers through a double-layered, nested structure of the casing, achieving a lightweight, high-strength, and highly sealed integrated battery casing.

[0028] More specifically, the transverse and longitudinal beam structure 8 includes a longitudinal beam 81 arranged along the length L direction of the battery box body 1, and a transverse beam 82 arranged along the width W direction of the battery box body 1.

[0029] It is worth noting that, in the present invention, the thickness of the upper box-type plate 2 is a, the thickness of the lower box-type plate 3 is b, and the thickness of the structural reinforcing side plate 4 is c, wherein a<c and b<c. In the battery box body 1, the bottom portion mainly bears loads such as the gravity of the battery pack and internal pressure, while the upper and lower box-type plates form a double-layer structure, and the overall bearing capacity of the double-layer structure has been fully guaranteed due to the substantial increase in the sectional moment of inertia. Therefore, thinner plates can be used to minimize the weight. In contrast, the side walls of the box body, especially the side walls on the length sides, need to bear lateral concentrated loads and bending moments generated under working conditions such as vehicle turning and collision, and are key areas for structural stress. In the present invention, the thickness c of the structural reinforcing side plate 4 disposed in this region is significantly larger than the thicknesses a and b of the upper and lower box-type plates, so that materials are precisely arranged at the部位 with the highest stress level, realizing the matching between material distribution and stress distribution, and avoiding the problem of large weight caused by the necessity of overall thickening of the traditional box body to meet lateral strength requirements.

[0030] More specifically, said a and b satisfy: a=b or a<b. When a=b, that is, the upper and lower box-type plates have the same thickness, it is convenient to implement stamping forming of plates with uniform specifications, and the double-layer structure has high symmetry when subjected to bending. When a<b, that is, the lower box-type plate 2 is slightly thicker than the upper box-type plate 3, this is because it is considered that the bottom of the box body needs to directly bear the full gravity load of the battery pack, bottom impact, gravel impact from the road surface and other more severe stress conditions. Making the lower box-type plate b, which undertakes main bearing and protection functions, slightly thicker can further improve the reliability of bottom protection while maintaining the total weight still in a lightweight state. The two solutions can be flexibly selected according to the specific application scenarios of the battery box body.

[0031] Said interlayer space 5 includes a water-cooled interlayer space 51 and a filler interlayer space 52 disposed at the bottom of the battery box body 1, and an inner interlayer space 53 disposed at the side portion of the battery box body 1.

[0032] Wherein, said water-cooled interlayer space 51 is located below the battery pack installation area, and the coverage area thereof is not less than the area of said battery pack installation area, and said cooling flow channels 6 are formed in said water-cooled interlayer space 51. This ensures that the entire bottom surface of each battery module can be covered by the cooling flow channels 6, realizing comprehensive and uniform heat exchange.

[0033] The filler interlayer space 52 is adjacent to the water-cooled interlayer space 51 and located at the bottom edge of the battery box body 1. The structural reinforcement filler 7 is filled within the filler interlayer space 52. The filler interlayer space 52 is arranged in the bottom edge area, adjacent to the water-cooled area but without interfering with it. The bottom edge is precisely the sensitive area where the box body is subjected to bottom scraping and lateral impact force transmitted to the bottom plate. Filling this area with structural reinforcement filler is equivalent to embedding a rigid internal skeleton into the weak edge of the interlayer space, effectively restraining the deformation tendency of the double-layer bottom plate edge, and playing a significant role in impact resistance and structural protection.

[0034] The structurally reinforced side panel 4 is disposed on the side of the battery box body 1, forming an outer interlayer space 40 between it and the side wall of the lower box-shaped panel 3; the inner interlayer space 53 is formed by the space between the side wall of the upper box-shaped panel 2 and the side wall of the lower box-shaped panel 3, thereby making the side panel of the battery box body 1 a three-layer panel structure with double interlayers. The inner and outer side interlayer spaces are arranged side by side along the side of the box body, and the three-layer panel structure formed is equivalent to embedding two reinforcing partitions in the side wall. When subjected to lateral impact, the two side interlayer spaces can deform and absorb energy in stages, and the interface between the multiple layers of panels can effectively prevent the penetration and propagation of cracks. It has a penetration resistance and energy absorption buffer effect that is far superior to a single-layer thick plate or a single interlayer structure, providing higher lateral protection safety for the internal battery pack.

[0035] More specifically, the filler interlayer space 52, the structural reinforcement filler 7, and the three-layer plate structure formed by the inner interlayer space 53 and the outer interlayer space 40 are all located on the length L side of the battery box body 1. Since the length L side has the largest span for a rectangular box structure, bending moments and deformations are mainly concentrated on the long side when subjected to longitudinal acceleration / deceleration inertial forces, lateral side impacts, or torsional conditions. Therefore, this invention concentrates the filler interlayer space 52 and the structural reinforcement filler 7, along with the three-layer plate structure with double interlayers on the side, on the length L side of the box body. This directional reinforcement differs from the traditional approach of uniformly thickening the entire box body without prioritizing any specific components. It accurately applies limited reinforcement materials to the most critical stress-bearing parts, achieving the maximum overall stiffness and lateral protection capability with minimal weight. This is the key to achieving both lightweight and high strength in this invention.

[0036] The structurally reinforced side plate 4 is a Z-shaped plate. The Z-shaped cross-section itself has a high moment of inertia in the thickness direction of the plate, which enhances its bending stiffness compared to a flat plate. Moreover, its lower end plate extends to the bottom of the lower box-shaped plate 3, forming a bottom support plate 41 that supports the battery box body 1 along the length L side from the bottom. When the box body is subjected to a side impact, the lateral force no longer relies solely on the shear and bending moment borne by the weld connecting the side plate and the bottom plate. Instead, part of the load is transferred to the bottom surface of the lower box-shaped plate 3 through the bottom support plate 41, allowing the bottom plate to participate in sharing the lateral load. The force transmission path is greatly optimized, the stress concentration at the connection is effectively alleviated, the failure risk of weld fatigue cracking and tearing at the side plate connection is reduced, and the fatigue life of the box body under vibration and impact conditions is extended.

[0037] In this invention, preferably, the structural reinforcement filler 7 is a zigzag or corrugated structural plate. Compared to flat fillers, corrugated structures have stronger compressive and bending resistance, and can provide higher sandwich support stiffness with a lighter material usage, thus improving both reinforcement effect and weight reduction.

[0038] like Figure 1 As shown, the upper box-shaped plate 2 and the lower box-shaped plate 3, as well as the battery box body 1 and the horizontal and vertical beam structures 8, are respectively fixedly connected by welding.

[0039] The connection between the upper and lower box-shaped plates must ensure a reliable connection between the double-layer shells and an absolute seal of the cooling channels 5 within the interlayer space. Therefore, in this invention, the upper box-shaped plate 2 and the lower box-shaped plate 3 are connected by vacuum brazing to seal the cooling channels 6. Vacuum brazing involves overall heating in a vacuum environment. The brazing filler metal penetrates and fills all the gaps between the upper and lower box-shaped plates uniformly through capillary action. A single heating process can simultaneously complete the connection of all large-area double-layer plates and the full-path sealing of all channel boundaries. The joints are dense and pore-free, and the entire welding process exhibits minimal thermal deformation, precisely maintaining the uniformity of the interlayer space gap dimensions. The battery box body 1 is connected to the transverse and longitudinal beam structures 8 by friction stir welding. The peak temperature of friction stir welding is lower than the material melting point, resulting in low heat input and therefore low residual stress and deformation. Since the upper and lower box-shaped plates have been vacuum brazed and the internal cooling channel sealing structure has been formed, the risk of cracking or thermal deformation of the sealed channel caused by high heat input welding can be avoided when using friction stir welding for subsequent connection.

[0040] In summary, this invention designs the casing as a double-layered structure with nested upper and lower layers. The interlayer space integrates cooling channels and structural reinforcement fillers, enabling the casing itself to possess thermal management and structural reinforcement functions. This eliminates the need for separate liquid cooling plates, reducing connection interfaces and leakage risks, and improving overall sealing reliability. The double-layered thin plates, compared to a single-layered thick plate of equal weight, have a larger moment of inertia and significantly enhanced bending and torsional stiffness. Combined with localized triple-layered plates and corrugated reinforcement fillers, higher structural load-bearing capacity and impact resistance are achieved while reducing overall weight. The bottom fully covered with channels ensures uniform cooling of the cells, while edge reinforcement and the double-layered sidewall structure precisely strengthen weak areas. The material distribution matches functional requirements, allowing the battery casing to simultaneously achieve lightweight, high strength, high sealing, and efficient thermal management.

[0041] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A highly sealed, integrated, liquid-cooled, lightweight battery housing, comprising a battery housing (1) and a transverse and longitudinal beam structure (8), wherein the battery housing (1) has a length L, a width W, and a height H, and the transverse and longitudinal beam structure (8) is disposed within the battery housing (1), characterized in that: The battery box body (1) includes an upper box-shaped plate (2), a lower box-shaped plate (3), and a structurally reinforced side plate (4). The upper box-shaped plate (2) and the lower box-shaped plate (3) are stacked and nested in the height H direction, so that the bottom plate and side plate of the battery box body (1) are both formed as a double-layer structure; and a sandwich space (5) is formed between the upper box-shaped plate (2) and the lower box-shaped plate (3), and a cooling channel (6) and structural reinforcement filler (7) are provided in the sandwich space (5). The structurally reinforced side plate (4) extends along the length L side and / or width W side of the battery box body (1) and is connected to the outside of the lower box plate (3) so that the box plate on the length L side and / or width W side of the battery box body (1) has a three-layer structure. The horizontal and vertical beam structures (8) are arranged in a crisscross pattern along the length L and width W of the battery box body (1), forming an internal support skeleton that internally supports and partitions the battery box body (1).

2. The strongly sealed integrated liquid-cooled lightweight battery housing according to claim 1, characterized in that: The thickness of the upper box-shaped plate (2) is a, the thickness of the lower box-shaped plate (3) is b, and the thickness of the structurally reinforced side plate (4) is c, wherein a < c and b < c.

3. The strongly sealed integrated liquid-cooled lightweight battery case according to claim 2, characterized in that: The condition a and b satisfy either a = b or a < b.

4. The strongly sealed integrated liquid-cooled lightweight battery case according to claim 1, characterized in that: The interlayer space (5) includes a water-cooled interlayer space (51) and a filler interlayer space (52) located at the bottom of the battery box body (1), and an inner interlayer space (53) located on the side of the battery box body (1). The water-cooled interlayer space (51) is located below the battery pack installation area, and its coverage area is not less than the area of ​​the battery pack installation area. The cooling channel (6) is formed in the water-cooled interlayer space (51). The filler interlayer space (52) is adjacent to the water-cooled interlayer space (51) and is located at the bottom edge of the battery box body (1). The structural reinforcement filler (7) is filled in the filler interlayer space (52). The structurally reinforced side panel (4) is disposed on the side of the battery box body (1) and forms an outer interlayer space (40) between it and the side wall of the lower box-shaped panel (3); the inner interlayer space (53) is formed by the space between the side wall of the upper box-shaped panel (2) and the side wall of the lower box-shaped panel (3), thereby making the side panel of the battery box body (1) a three-layer panel structure with double interlayer.

5. The strongly sealed integrated liquid-cooled lightweight battery housing according to claim 4, characterized in that: The filler interlayer space (52) and the structural reinforcement filler (7), as well as the three-layer plate structure formed by the inner interlayer space (53) and the outer interlayer space (40), are all located on the length L side of the battery box body (1).

6. A highly sealed integrated liquid-cooled lightweight battery housing according to claim 4 or 5, characterized in that: The structurally reinforced side plate (4) is a Z-shaped plate, with its short end extending to the bottom of the lower box-shaped plate (3) to form a bottom support plate (41) that supports the battery box body (1) from the bottom along the length L side.

7. A highly sealed integrated liquid-cooled lightweight battery housing according to claim 1 or 4, characterized in that: The structural reinforcement filler (7) is a zigzag or wavy structural plate.

8. The strongly sealed integrated liquid-cooled lightweight battery case according to claim 1, characterized in that: The upper box-shaped plate (2) and the lower box-shaped plate (3), as well as the battery box body (1) and the horizontal and vertical beam structure (8), are respectively fixedly connected by welding.

9. A highly sealed, integrated, liquid-cooled, lightweight battery housing according to claim 8, characterized in that: The upper box plate (2) and the lower box plate (3) are connected by vacuum brazing to seal the cooling channel (6); the battery box body (1) and the horizontal and vertical beam structure (8) are connected by friction stir welding.

10. A highly sealed integrated liquid-cooled lightweight battery housing according to claim 1, 8, or 9, characterized in that: The transverse and longitudinal beam structure (8) includes a longitudinal beam (81) arranged along the length L direction of the battery box body (1) and a transverse beam (82) arranged along the width W direction of the battery box body (1).

Images