A new energy battery box with multi-layer sealing

Abstract

The application discloses a new energy battery box sealed in multiple layers, and relates to the field of battery boxes. The battery box is mainly composed of a box body for bearing battery units, a box cover for closing the opening of the box body, and a bolt assembly for fastening and connecting the box body and the box cover. The opening edge of the box body is provided with a plurality of bolt holes, the box cover is provided with through holes corresponding to the bolt holes, and fastening bolts are arranged in the through holes and screwed into the bolt holes of the box body to rigidly lock the box cover and the box body. In order to improve the sealing performance of the joint interface between the box body and the box cover, a first sealing element is arranged in the outer side region of the box body edge. The application provides basic sealing through the first sealing element, and a second sealing element can automatically trigger sealing enhancement according to the environmental moisture contact signal after the basic sealing fails, and sealing treatment is performed on the bolt connection hole.

Description

Technical Field

[0001] This application relates to the field of battery boxes, and in particular to a multi-layer sealed new energy battery box. Background Technology

[0002] As a core safety component of the power battery system in new energy vehicles, the primary function of the battery box is to provide reliable environmental isolation protection for critical devices such as the internal high-voltage battery modules and battery management system. Given that new energy vehicles inevitably face risks such as high temperature, high humidity, rain immersion, and even submersion, as well as continuous vibration and impact during operation, extremely stringent requirements are placed on the sealing performance of the battery box. Any seal failure in the box can lead to moisture intrusion, decreased insulation performance, and even serious safety accidents such as short circuits, corrosion, or thermal runaway. Currently, the most common battery box sealing method in the industry relies on a single-layer sealing structure between the top cover and the box body. This is achieved by setting a single rubber sealing ring or applying sealant to the mating surface and applying pressure using bolts. This structural design is simple, easy to assemble, and is currently the mainstream technical solution.

[0003] However, existing single-layer sealing structures are significantly inadequate in ensuring the sealing reliability of battery boxes under long-term, complex operating conditions. The root causes are twofold. First, a single sealing interface is subjected to multiple environmental stresses: under drastic temperature fluctuations (such as the self-heating of battery charging and discharging and ambient temperature differences), the difference in thermal expansion coefficients between different materials (such as the box metal, the composite material of the top cover, and the rubber seals) can lead to uneven deformation or fretting displacement at the joint surface; continuous vibration and impact accelerate the attenuation of bolt preload, affecting the stable maintenance of sealing pressure. The cumulative effect of these dynamic loads makes a single sealing interface highly susceptible to micro-cracks or stress relaxation. Second, and more critically, existing structures struggle to effectively block potential leakage risks along the bolt hole path. Water molecules or moisture can penetrate through two main pathways: firstly, the thread gap between the bolt itself and the inner wall of the mounting hole forms a capillary penetration channel; secondly, vibration causes tiny gaps to form between the bottom of the bolt head or the contact surface between the gasket and the box, creating conditions for leakage. If a weak point appears in the initial seal, especially in high-pressure water environments (such as wading or heavy rain), the water flow will accelerate the penetration process. Furthermore, the hardening and cracking of rubber seals due to environmental aging (such as ozone and extreme temperatures) during long-term service will further exacerbate the risk of seal failure. The combined effect of these factors makes it difficult for traditional single-layer sealing structures to guarantee the absolute sealing integrity of the battery box throughout its entire lifespan and under extreme conditions, creating potential safety hazards.

[0004] Therefore, in order to improve the environmental protection level and long-term reliability of new energy battery boxes, especially battery systems with "zero tolerance" for sealing failure, it is imperative to develop a more advanced and reliable multi-layer sealing structure. Utility Model Content

[0005] The purpose of this application is to overcome at least one deficiency of the prior art and to provide a multi-layer sealed new energy battery box.

[0006] To achieve the above objectives, this application discloses a multi-layer sealed new energy battery box, which mainly consists of a box body that carries battery units, a box cover that closes the opening of the box body, and a bolt assembly that secures the two together.

[0007] The box body opening edge is provided with multiple bolt holes, and the box cover has a corresponding through hole. The fastening bolt is inserted through the through hole and screwed into the bolt hole of the box body to achieve rigid locking between the box cover and the box body.

[0008] To improve the sealing performance of the interface between the enclosure and the lid, a first sealing element is arranged on the outer edge of the enclosure. Specifically, this first sealing element is fixedly installed on the upper surface of the enclosure edge, and it is a solid structure with an elliptical cross-section. The lower edge of the lid has a receiving structure that matches the shape of the first sealing element. When the lid and enclosure are fastened together with bolts, this receiving structure applies pressure to the first sealing element, forcing it to undergo elastic deformation to fill the gap in the contact area, thereby forming the initial first sealing barrier.

[0009] An annular second seal is located on the inner edge of the enclosure, adjacent to the first seal. This second seal has a rectangular cross-section and comprises an outer layer and an inner layer. The outer layer is an elastic hollow colloid, filled with a solid water-absorbing and swelling agent to form the inner layer. The hollow colloid has several through-holes, allowing communication between the interior and the external environment. When external liquid seeps between the lid and the enclosure due to the failure of the first seal, the liquid contacts and wets the water-absorbing and swelling agent through the through-holes. The agent then absorbs moisture and undergoes significant volume expansion, causing the outer elastic colloid to expand and deform outwards simultaneously. This expansion significantly enhances the filling capacity and sealing contact pressure of the second seal under pressure.

[0010] To optimize the sealing performance of the second seal after water absorption and expansion, an inverted V-shaped guide groove is designed on the lower surface of the cover where it mates with the second seal. As the second seal expands and grows upwards due to water absorption, the sidewall structure of this inverted V-shaped groove guides and constrains the expanding elastic colloid. The expanding colloid fills the groove and undergoes adaptive deformation, ultimately forming a tight and increased contact area with the inner wall of the inverted V-shaped groove. This creates a reinforced, actively formed additional sealing interface on top of the original seal.

[0011] In addition, to prevent environmental media from seeping in along the bolt assembly, a sealant layer is specifically provided on the inner wall of the bolt holes located on the housing. After curing, this sealant layer effectively fills the microscopic gap between the bolt shank and the inner wall of the bolt hole, sealing off potential leakage paths and further improving the overall sealing reliability.

[0012] Compared with the prior art, this application provides a basic seal through the first sealing element, and the second sealing element can automatically trigger the sealing enhancement based on the environmental moisture contact signal after the basic seal fails. Combined with the sealing treatment of the bolt connection hole, a progressive multi-seal protection system combining the outside to the inside and the passive and active methods is constructed.

[0013] The beneficial effects listed above are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementation methods will be further disclosed in the embodiments or other descriptive sections of this application. Attached Figure Description

[0014] A better understanding of various aspects of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. The positions, dimensions, and extents of the structures shown in the drawings, etc., do not always represent actual positions, dimensions, and extents. In the drawings:

[0015] Figure 1 This is an exploded view of one embodiment disclosed in this application.

[0016] Figure 2 This is a partial structural diagram of one embodiment disclosed in this application.

[0017] Figure 3 This is a cross-sectional structural diagram of a second sealing element in an embodiment disclosed in this application. Detailed Implementation

[0018] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0019] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0020] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail; however, where appropriate, such techniques, methods, and apparatus should be considered part of this specification.

[0021] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the relevant listed items.

[0022] See attached document Figures 1 to 3 This embodiment relates to a multi-layer sealed new energy battery box, which aims to effectively improve the sealing performance of the battery box through a multi-layer sealing structure, preventing external liquids, gases, and impurities from seeping into the battery box, thereby ensuring the safe operation and service life of the battery cells. The following will describe in detail the implementation of this battery box, including the design principles, material selection, structural fit, and working principle of each component.

[0023] This multi-layered sealed new energy battery box mainly consists of a box body 1, a box cover 2, and a bolt assembly 3. The box body 1 is integrally formed from high-strength aluminum alloy, with a cuboid structure. Its interior is used to house the new energy battery units, and multiple bolt holes are evenly distributed along its opening edge. The box cover 2 is shaped to match the opening of the box body 1, and its edge has through holes corresponding to the bolt holes in the box body 1. The bolt assembly 3 includes bolts and nuts. The bolts pass through the through holes in the box cover 2 and the bolt holes in the box body 1 in sequence before engaging with the nuts to achieve a tight connection between the box cover 2 and the box body 1. To improve sealing performance, multiple sealing structures are set at the interface between the box body 1 and the box cover 2, specifically including a first sealing element 4, a second sealing element 5, and a sealing adhesive layer inside the bolt holes. These sealing structures work together to construct a comprehensive sealing and protection system.

[0024] As the core component carrying the battery unit, the housing 1 is made of high-strength aluminum alloy, which has good mechanical strength, corrosion resistance, and electrical insulation properties, providing stable support and protection for the battery unit. The housing 1 is manufactured using a one-piece molding process, ensuring the integrity of the overall structure and the sealing performance. An annular flange extends outward from the opening edge of the housing 1, with the flange thickness precisely controlled within a reasonable range. The upper surface of this flange is fixedly fitted with the first sealing element 4, providing a stable mounting base for the seal.

[0025] The lid 2 is fitted to the body 1, and its edge has through holes corresponding to the bolt holes of the body 1. It is tightly connected to the body 1 by bolt assembly 3. The lower surface edge of the lid 2 has an annular groove that matches the shape of the first seal 4. This groove is used to apply pressure to the seal when the lid 2 and body 1 are closed, causing it to undergo elastic deformation, thereby forming the initial first sealing barrier. In addition, a guide groove 6 with an inverted V-shaped cross section is designed in the area where the lower surface of the lid 2 mates with the second seal 5. When the second seal 5 expands in volume and expands upward due to water absorption, the guide groove 6 guides and constrains the expanding elastic colloid, allowing the expanding colloid to fill the groove and undergo adaptive deformation. Finally, it forms a tight and increased contact area with the inner wall of the guide groove 6, establishing a reinforced additional sealing interface.

[0026] Bolt assembly 3 consists of bolts and nuts. The bolts are made of high-strength stainless steel, possessing excellent tensile strength and corrosion resistance. Their dimensions are designed according to the connection strength requirements between the housing 1 and the cover 2, ensuring sufficient preload to achieve a tight connection between the cover 2 and the housing 1. The bolts pass through the through holes in the cover 2 and the bolt holes in the housing 1 in sequence before engaging with the nuts. By controlling the tightening torque of the nuts, the cover 2 and the housing 1 are tightly joined, simultaneously compressing the sealing components to ensure their sealing function.

[0027] The first seal 4 is fixedly installed on the upper surface of the edge of the housing 1. It is a solid structure with an elliptical cross-section, made of high-quality elastic material with good elasticity, aging resistance, and weather resistance. This seal is fixed to the flange of the housing 1 with a special adhesive. When the cover 2 is tightened to the housing 1 with bolts 3, the annular groove on the lower edge of the cover 2 applies pressure to the first seal 4, forcing it to undergo elastic deformation to fill the tiny gaps in the contact area, thus forming the initial first sealing barrier. In actual working conditions, such as when the battery box is exposed to rain in the field, the first seal 4 can effectively prevent most liquid intrusion, ensuring the operating environment of the battery cells.

[0028] The second seal 5 is located on the inner edge of the housing 1, adjacent to the first seal 4. It has a rectangular cross-section and a ring structure, employing a multi-layer composite design. Its outer layer 501 is an elastic hollow colloid, and the inner layer 502 is filled with a water-absorbing and expanding material. The outer layer 501 has regularly distributed through-holes, allowing communication between the inside and outside of the colloid. When external liquid seeps between the housing cover 2 and the housing 1 due to the failure of the first seal, the liquid can contact and wet the water-absorbing and expanding material in the inner layer 502 through the holes. Upon contact with water, the water-absorbing and expanding material rapidly expands, pushing the elastic colloid in the outer layer 501 outwards. This expansion, combined with the guide groove 6 on the lower surface of the housing cover 2, guides and constrains the expanding elastic colloid, allowing it to fill the groove and undergo adaptive deformation, forming a tight and increased contact area with the groove wall, thus establishing a reinforced additional sealing interface. In simulated battery box immersion tests, after prolonged soaking, the sealing structure effectively prevented further liquid penetration, significantly improving the sealing reliability of the battery box under extreme environments.

[0029] To prevent environmental media from seeping in along bolt assembly 3, a sealant layer (not shown in the figure) is formed on the inner wall of the bolt holes located on housing 1. The sealant has good elasticity and weather resistance; after curing, it effectively fills the microscopic gaps between the bolt shank and the inner wall of the bolt hole, sealing potential leakage paths. Even under varying bolt preload conditions, the sealant layer maintains stable sealing performance, ensuring the reliability of the bolt connection. In the battery box vibration test, after multiple vibration cycles, no liquid leakage occurred at the bolt connection, effectively ensuring the sealing integrity of the battery box under dynamic conditions.

[0030] The multi-layer sealed new energy battery box of this embodiment demonstrates excellent sealing performance in practical applications. In outdoor photovoltaic power station scenarios, the battery box withstood the test of continuous rainfall and dusty environments, maintaining a dry and condensation-free internal state. Compared with traditional single-sealed battery boxes, the leakage rate of this multi-layer sealed structure is significantly reduced, significantly improving the reliability and safety of the new energy battery system. It meets the stringent battery protection requirements of applications such as electric vehicles and energy storage power stations, effectively extending battery life and maintenance cycles. In electric vehicle applications, this battery box can still ensure the safe operation of battery cells under complex road conditions and severe weather conditions encountered during vehicle operation, such as driving through water and being splashed with mud and sand. It reduces the risk of battery failure caused by external environmental factors, improving the overall performance of new energy vehicles and user satisfaction.

[0031] While exemplary embodiments of this disclosure have been described, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope thereof. Therefore, all changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A multi-layer sealed new energy battery box, characterized in that, The battery box mainly consists of a box body that carries the battery cells, a box cover that closes the opening of the box body, and a bolt assembly that secures the two together. The box body opening edge is provided with multiple bolt holes, and the box cover has a corresponding through hole. The fastening bolt is inserted through the through hole and screwed into the bolt hole of the box body to achieve rigid locking between the box cover and the box body. A first sealing element is arranged on the outer edge of the box. Specifically, the first sealing element is fixedly installed on the upper surface of the edge of the box. It is a solid structure with an elliptical cross-section. The lower edge of the box cover has a receiving structure that matches the shape of the first sealing element. An annular second seal is provided on the inner side of the housing edge, adjacent to the first seal. The second seal has a rectangular cross-section.

2. A multi-layer sealed new energy battery box as claimed in claim 1, characterized in that, The second sealing element includes an outer layer and an inner layer. The outer layer is an elastic hollow colloid, and the inner layer is filled with a solid water-absorbing and swelling agent. The hollow colloid has several through holes, so that the interior of the colloid is connected to the external environment.

3. A multi-layer sealed new energy battery box as claimed in claim 2, characterized in that, A guide groove with an inverted V-shaped cross-section is designed on the lower surface of the cover in the area where it mates with the second seal.

4. A multi-layer sealed new energy battery box as claimed in claim 1, characterized in that, A sealant layer is provided on the inner wall of the bolt holes located on the housing.

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