Cell PACK anti-loosening fixing device and assembling method thereof

Abstract

The invention discloses an anti-loosening fixing device for a battery cell PACK, and the device comprises a battery cell box which comprises a battery lower housing and a blocking frame surrounding the periphery of the battery lower housing, and is used as a bearing structure of the battery cell; the battery cell module fixing structure is arranged in the battery cell box body, a battery cell module fixing cavity is formed in the battery cell module fixing structure, and the battery cell module fixing structure is used for accommodating and positioning a battery cell module; and the anti-loosening fixing structure is detachably mounted on the battery lower shell, is connected with the battery cell module fixing structure and is used for locking and fixing the battery lower shell and the battery cell module fixing structure. The anti-loosening device has the beneficial effects that a special anti-loosening structure is designed on the basis of the physical principle of the wedging effect, rotation energy causing loosening is actively converted into locking force for restraining loosening, crossing from passive resisting to active locking is achieved, rapid disassembly and assembly, long-acting vibration resistance and creep aging resistance are achieved, and the service life of the anti-loosening device is prolonged. The industrial problem that a traditional fixing mode cannot give consideration to maintenance convenience and long-term reliability is effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of battery assembly technology and relates to a battery cell PACK anti-loosening fixing device and its assembly method. Background Technology

[0002] Battery pack (PACK) is a comprehensive and interdisciplinary engineering technology field. Its core task is to scientifically integrate individual battery cells into a system that can safely, reliably, and efficiently provide energy to specific devices or vehicles. This field encompasses five key technologies: cell selection and matching technology requires choosing cathode materials (such as lithium iron phosphate and ternary lithium) based on the application scenario and ensuring high uniformity of cell performance through consistent sorting; mechanical structure and thermal management design focuses on optimizing modular housing strength, lightweighting, and cooling systems (air cooling / liquid cooling / phase change materials); the battery management system (BMS) acts as the "brain," responsible for cell status monitoring, SOC / SOH / SOP estimation, and safety protection; electrical connection and high-voltage safety design includes bus layout, insulation monitoring, and high-voltage interlocking mechanisms; and manufacturing processes involve key aspects such as laser welding, torque control, and automated assembly, directly affecting the consistency and reliability of the PACK.

[0003] Currently, battery packs mainly use two fixing methods to secure the battery module to the bottom of the casing: structural adhesive and foam adhesive. However, both methods have significant technical drawbacks. Structural adhesive is irreversible after curing, leading to difficult maintenance, high recycling costs, and the difficulty in regenerating materials, which may be environmentally unfriendly. The process requirements are stringent, and performance degradation can easily occur due to uneven application or insufficient curing. High-modulus adhesives constrain cell expansion, causing accelerated decay of mechanical stress and reduced reliability after long-term aging. At the same time, high thermal conductivity can accelerate the spread of thermal runaway, posing challenges to fireproofing designs. The overall cost is comparable to traditional solutions due to the amount of adhesive used and equipment investment. The use of foamed adhesive to fix battery modules has the following drawbacks: limited thermal conductivity, easily becoming a heat dissipation bottleneck at high energy densities, leading to increased cell temperature and affecting fast charging performance and safety; insufficient strength and structural support, its "foam" characteristics result in low compressive and shear strength, failing to provide sufficient rigidity, requiring the use of end plates, side plates, and other structural components; complex and difficult-to-control manufacturing process, the foaming process is sensitive to temperature, humidity, and environmental pressure, easily causing cell deformation due to excessive pressure (such as separator tearing, internal short circuit), and it is difficult to ensure the consistency of the foaming state; prominent long-term aging and chemical stability issues, easily pulverizing, becoming brittle, and precipitating corrosive substances at high temperatures, requiring verification of electrolyte resistance; extremely poor repairability and recyclability, after solidification forming a monolithic "cake," making it difficult to repair and separate the cells, hindering material regeneration; in addition, its porous structure and thermal insulation may lead to heat accumulation during thermal runaway, and its flammability may contribute to the spread of fire.

[0004] Therefore, given the technical shortcomings of existing structural adhesives and foam adhesives for fixing (such as difficulty in maintenance, mechanical stress damage, risk of thermal runaway, and obstacles to recycling), developing a battery cell PACK fixing structure and matching assembly process that combines rapid disassembly and assembly capabilities, resistance to long-term vibration, and resistance to material creep and aging loosening has become an urgent need for the industry to break through technical bottlenecks and achieve sustainable development. Summary of the Invention

[0005] In response to the shortcomings of existing battery pack fixing technologies (structural adhesive / foaming adhesive) such as maintenance difficulties, mechanical stress damage, thermal runaway risks, and recycling obstacles, this application provides a battery pack anti-loosening fixing device and assembly method. Through innovative structural design, it achieves rapid disassembly and assembly, long-term vibration resistance, and creep aging resistance, effectively solving the industry pain point that traditional fixing methods cannot balance maintenance convenience and long-term reliability.

[0006] To solve the above problems, the technical solution adopted in this application is:

[0007] This invention provides a battery cell PACK anti-loosening fixing device, comprising:

[0008] The cell housing includes the lower battery casing and the baffle frame surrounding the lower battery casing, serving as the supporting structure for the cell.

[0009] A cell module fixing structure is disposed within the cell housing, and an internal cell module fixing cavity is formed therein for accommodating and positioning the cell module; and

[0010] The anti-loosening fixing structure is detachably installed on the lower battery casing and connected to the cell module fixing structure. It is used to lock and fix the lower battery casing and the cell module fixing structure to resist vibration and prevent loosening.

[0011] As a preferred embodiment of this application, the upper surface of the lower battery housing is provided with a plurality of fixed mounting positions, each of the fixed mounting positions being provided with a mounting post that is perpendicular to the upper surface of the lower battery housing and extends upward; the mounting post is internally defined with an axially penetrating cavity, and the inner wall of the cavity is covered with an insulating layer, which is used to achieve buffering and electrical isolation between the cell module fixing structure and the lower battery housing.

[0012] As a preferred embodiment of this application, the mounting post is connected to the lower casing of the battery by integral molding or welding.

[0013] As a preferred embodiment of this application, the insulating layer is an elastic insulator, such as one made of high-performance engineering plastics (e.g., PA66+GF30 or similar materials). This elastic insulating layer effectively absorbs and attenuates high-frequency vibrations from the vehicle's road surface, preventing direct and rigid transmission of vibrations to the battery module. The insulating layer also provides electrical insulation between the fasteners and the battery's lower casing, preventing electrochemical corrosion and potential short-circuit risks. Furthermore, the overmolding process ensures a firm bond between the mounting post and the battery's lower casing, avoiding the risk of loosening associated with traditional press-fit mounting posts.

[0014] As a preferred embodiment of this application, the axial height of each of the mounting posts is the same, and their top surfaces are coplanar with the same horizontal plane, which can maintain the installation level of the battery cell module fixing structure.

[0015] As a preferred embodiment of this application, the cell module fixing structure includes:

[0016] A battery cell module mounting bracket includes a pair of parallel end clamping plates and a peripheral connecting rod, which together form a battery cell module mounting cavity for accommodating and positioning the battery cell module; and

[0017] The connecting structure is located on the side of the cell module fixing frame. The connecting wing plate on it is parallel to the upper surface of the lower battery housing and has a through hole. The position and size of the through hole correspond one-to-one with the axial through cavity of the mounting post. The cell module fixing structure and the lower battery housing are quickly positioned and fixed by the cooperation of the mounting post and the through hole.

[0018] As a preferred embodiment of this application, the connecting structure is a T-shaped sheet metal part, which is integrally formed from a vertical connecting plate and a connecting wing plate, and the vertical connecting plate and the connecting wing plate are perpendicular to each other. The vertical connecting plate is fixedly installed on the baffle frame. The connecting wing plate is horizontal and is used to achieve horizontal connection or positioning with other components. Through the structural design of integrally formed sheet metal parts, both connection stability and processing convenience are taken into account. The fact that the connecting structure is a sheet metal part can greatly enhance its local rigidity and provide a solid and flat force-bearing surface for subsequent fastening.

[0019] As a preferred embodiment of this application, the anti-loosening fixing structure includes:

[0020] The self-locking anti-loosening component includes a pair of stacked washers facing each other. Each washer has a meshing surface and a bearing surface on opposite sides. The meshing surface is provided with sloping serrations, and the two washers mesh with each other through the sloping serrations. The bearing surface is machined with anti-slip teeth.

[0021] The fastener passes through the corresponding through hole and axial through cavity in sequence and is threaded to the nut. The pre-tightening force of the threaded connection realizes the anti-loosening and locking of the battery lower shell and the cell module fixing structure.

[0022] As a preferred embodiment of this application, the meshing surface is an annular surface, which extends spirally along its circumference as a base to form a spiral trajectory. On the spiral trajectory, multiple sloping saw teeth are divided by height differences, and each sloping saw tooth is distributed along the spiral line, ultimately forming a spiral stepped structure on the annular surface.

[0023] As a preferred embodiment of this application, the ramp-type saw teeth are wedge-shaped, comprising a first inclined surface and a first transition surface connecting the first inclined surface, wherein:

[0024] The first inclined surface has a first connecting edge and a second connecting edge arranged radially. The first connecting edge is connected to the lower edge of the first transition surface of the inclined saw tooth, and the second connecting edge is connected to the upper edge of the first transition surface of the adjacent inclined saw tooth. The height of the first connecting edge exceeds that of the second connecting edge.

[0025] As a preferred embodiment of this application, the slope of the sloping saw teeth is greater than the thread helix angle. When two washers are stacked facing each other, the sloping saw teeth of the two washers mesh with each other to form an "interlocking" structure. This interlocking relationship can effectively limit the relative rotation between the washers and block the initial force of loosening from the structural level, which is the physical basis for the "wedge effect".

[0026] As a preferred embodiment of this application, the slope of the sloping saw teeth is 8-30°.

[0027] This invention achieves the connection between the battery lower casing and the cell module fixing structure through an anti-loosening fixing structure. When the entire system is subjected to external vibration, and the fasteners exhibit a slight tendency to loosen and rotate, the sloping serrations on the meshing surfaces of the washers, being greater than the thread helix angle, force the sloping serrations of the two washers to slide relative to each other and generate radial expansion—this is the "wedge effect." This effect converts the rotational tendency of the fasteners into a huge locking force between the washers, thus acting like a "mechanical lock," firmly locking the fasteners (such as bolts) in their current position and preventing any further loosening.

[0028] As a preferred embodiment of this application, the bearing surface is an annular surface, which extends spirally along its circumference to form a spiral trajectory. Multiple anti-slip teeth are divided by height differences on the spiral trajectory, and each anti-slip tooth is distributed along the spiral line, ultimately forming a spiral stepped structure on the annular surface.

[0029] As a preferred embodiment of this application, the anti-slip teeth are distributed radially or in a stepped pattern on the bearing surface, forming a sawtooth texture, which is used to disperse axial load and prevent the washer from sliding relative to each other under vibration or impact. When the washer is subjected to external force (such as vibration or impact), the anti-slip teeth further suppress the relative sliding between the washer and the contact parts (such as connecting flanges, fasteners, etc.) by increasing the friction of the contact surface, thereby enhancing the anti-loosening effect from the friction level.

[0030] As a preferred embodiment of this application, the anti-slip teeth are wedge-shaped, comprising a second inclined surface and a second transition surface connecting the second inclined surface, wherein:

[0031] The second inclined surface has a first edge and a second edge arranged radially. The first edge is connected to the upper edge of the second transition surface of the anti-slip tooth, and the second edge is connected to the lower edge of the second transition surface of the adjacent anti-slip tooth. The height of the first edge exceeds that of the second edge.

[0032] As a preferred embodiment of this application, the inclination angle of the second inclined surface should be controlled between 8° and 30°. If the angle is too small, the wedging effect will be insignificant and the anti-loosening ability will decrease; if the angle is too large, it may be difficult to generate sufficient radial force between the meshing surfaces of the washers, and may even affect normal tightening.

[0033] As a preferred embodiment of this application, the slope length of the first inclined plane is 1 to 3 times the slope length of the second inclined plane. More preferably, it is 2 times.

[0034] As a preferred embodiment of this application, both the first transition surface and the second transition surface are disposed along the thickness direction of the gasket, and the first transition surface and at least one second transition surface are coplanar in the thickness direction of the gasket.

[0035] This invention optimizes the fastener's locking force and stress distribution through the synergistic design of ramp-type saw teeth and anti-slip teeth, achieving this through three aspects: structural layering, functional differences, and directional complementarity. The ramp-type saw teeth include a first ramp surface and a first transition surface connecting the first ramp surface. The first ramp surface acts as an "engaging surface," preventing misalignment, while the first transition surface acts as a "connecting surface," connecting adjacent ramp-type saw teeth to ensure overall structural continuity and forming a basic load-bearing structure of "ramps-transition surfaces." The height difference between the first and second connecting edges achieves spatial misalignment / stress differences between the saw teeth, converting the fastener's rotational tendency into a large locking force between the washers, thus achieving anti-slip between the two washers. Similarly, the anti-slip teeth include a second ramp surface and a second transition surface connecting the second ramp surface, forming a basic load-bearing structure of "ramps-transition surfaces." The height difference between the first and second edges also contributes to this effect. This invention achieves spatial misalignment and stress difference between the anti-slip teeth, with the first inclined surface of the ramp-type saw teeth and the second inclined surface of the anti-slip teeth tilting in opposite directions. The advantages are: Enhanced spatial misalignment: The opposite inclined surface design makes the spatial misalignment of the ramp-type saw teeth / anti-slip teeth more significant, avoiding structural "overlap" or "synchronous stress," and improving the overall layout rationality; Amplified stress difference: The opposite inclined surfaces combined with the height difference allow the ramp-type saw teeth / anti-slip teeth to distribute stress more evenly, further optimizing functional efficiency; Enhanced stress dispersion: The opposite inclined surface design can more evenly disperse stress (such as the impact force when the washer rotates, the lateral force when the anti-slip teeth mesh), reducing the risk of local stress concentration. This invention achieves efficient conversion of fastener locking force and full dispersion of stress through a triple design of "structural layering of ramp-type saw teeth and anti-slip teeth, height difference misalignment, and complementary directions," improving overall technical performance.

[0036] The present invention also provides an assembly method for the cell PACK anti-loosening fixing device, comprising the following steps:

[0037] Step 1, Pre-assembly: Place the two washers of the self-locking anti-loosening component on the upper surface of the connecting wing plate of the cell module fixing structure after the two washers are in contact with each other with their meshing surfaces, so that the anti-slip surface of the lower washer contacts the connecting wing plate.

[0038] Step 2, Positioning: Place the battery cell module fixing structure with the installed battery module on the lower battery housing, so that the mounting post passes through the through hole on the connecting wing plate and the inner hole of the self-locking anti-loosening component in sequence;

[0039] Step 3, Tightening: After passing the fastener through the inner hole and through hole of the self-locking anti-loosening component, screw it into the axial through cavity and connect it with the nut in the mounting column. Keep the anti-slip surface of the washer pressed against the upper surface of the connecting wing plate and the bearing surface of the fastener. The assembly is complete.

[0040] The present invention also provides a start-stop battery PACK, including a cell PACK anti-loosening fixing device.

[0041] Compared with the prior art, the beneficial effects of this application are:

[0042] 1. A fundamental solution to prevent loosening: Unlike traditional spring washers that only provide elasticity or ordinary anti-loosening washers that rely solely on friction, this invention is based on the physical principle of the "wedge effect," which actively converts the rotational energy (vibration) that causes loosening into a locking force that inhibits loosening. This achieves a leap from "passive resistance" to "active locking," resulting in extremely reliable and permanent anti-loosening performance.

[0043] 2. System-level structural stability: This invention is not an isolated fastener improvement, but rather a complete system that goes from "rubber-coated mounting post (shock absorption and buffer)" to "rigid connection structure (providing a solid load-bearing base)" and then to "core anti-loosening fixing structure (active locking)," which comprehensively improves the connection reliability and structural integrity of the battery module under harsh working conditions.

[0044] 3. Multiple safety guarantees: The rubber-coated structure provides physical insulation, eliminating the risks of conduction and corrosion; the excellent anti-loosening capability ensures stable contact resistance at electrical connection points, avoiding serious safety hazards such as overheating and arcing caused by loosening, and greatly improving the life cycle safety performance of the battery pack.

[0045] 4. Combining processability and economy: This assembly process only adds a double-overlap washer placement step to the conventional process. It requires no special tools or complicated operations and is easy to implement on existing production lines. Its long-term reliability and maintenance-free operation reduce the total life cycle cost of the product. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the structure of the battery cell PACK anti-loosening fixing device of the present invention.

[0047] Figure 2 This is a top view of the battery cell PACK anti-loosening fixing device of the present invention.

[0048] Figure 3 This is a partial cross-sectional view of the battery cell PACK anti-loosening fixing device of the present invention.

[0049] Figure 4 yes Figure 3 A magnified view of a portion at point A.

[0050] Figure 5 This is a top view of the battery cell housing of the present invention.

[0051] Figure 6 for Figure 5 A partial sectional view.

[0052] Figure 7 This is a schematic diagram of the battery cell module fixing structure of the present invention.

[0053] Figure 8 This is a schematic diagram of the anti-loosening fixing structure of the present invention.

[0054] Figure 9 This is one of the structural schematic diagrams of the self-locking anti-loosening component of the present invention.

[0055] Figure 10 This is the second structural schematic diagram of the self-locking anti-loosening component of the present invention.

[0056] Figure 11 This is the third schematic diagram of the self-locking anti-loosening component of the present invention.

[0057] Figure 12 This is a schematic diagram of the start-stop battery PACK of the present invention.

[0058] Figure 13 This is a schematic diagram of the anti-loosening fixing structure of the present invention under stress.

[0059] Figure 14 This is a flowchart illustrating the assembly process of the start-stop battery PACK of the present invention.

[0060] 1-Cell housing; 11-Battery lower casing; 111-Mounting post; 112-Nut; 12-Baffle frame;

[0061] 2-Cell module fixing structure; 21-Cell module fixing frame; 211-End clamping plate; 212-Connecting rod; 22-Connecting structure; 2221-Connecting wing plate; 222-Through hole; 223-Vertical connecting plate;

[0062] 3-Anti-loosening fixing structure; 31-Self-locking anti-loosening component; 311-Washer; 312-Sloping serrations; 3121-First slope; 3122-First transition surface; 3123-First connecting edge; 3124-First connecting edge; 313-Anti-slip teeth; 3131-Second slope; 3132-Second transition surface; 3133-First edge; 3134-First edge; 32-Fastener;

[0063] 4-Battery cell module. Detailed Implementation

[0064] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application.

[0065] It should be noted that the process equipment or apparatus not specifically mentioned in the following embodiments are all conventional equipment or apparatus in the art.

[0066] Furthermore, it should be understood that the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps, does not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise stated. It should also be understood that the combined connection relationship between one or more devices / apparatus mentioned in this application does not preclude the existence of other devices / apparatus before or after the combined devices / apparatus, or the insertion of other devices / apparatus between these explicitly mentioned devices / apparatus, unless otherwise stated. Moreover, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or limiting the scope of implementation of this application. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this application.

[0067] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0068] In the description of this application, it should be understood that the terms "upper," "lower," "left," "right," "inner," "outer," "axial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, features defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0069] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] The present application will be further described below with reference to specific embodiments, but the scope of protection of the present application is not limited thereto.

[0072] like Figures 1-3 As shown, the present invention provides a battery cell PACK anti-loosening fixing device, comprising:

[0073] The cell housing 1 includes a lower battery casing 11 and a baffle frame 12 surrounding the lower battery casing 11, serving as a support structure for the battery cell.

[0074] A cell module fixing structure 2 is disposed within the cell housing 1, and an internal cell module fixing cavity is formed therein for accommodating and positioning the cell module 4; and

[0075] The anti-loosening fixing structure 3 is detachably installed on the lower battery housing 11 and connected to the cell module fixing structure 2. It is used to lock and fix the lower battery housing 11 and the cell module fixing structure 2 to resist vibration and prevent loosening.

[0076] like Figures 3-6 As shown, the upper surface of the lower battery housing 11 has a plurality of fixed mounting positions. Each fixed mounting position is provided with a mounting post 111 that is perpendicular to the upper surface of the lower battery housing 11 and extends upward, and a nut 112 that is embedded in the axial through cavity. The mounting post 111 defines an axial through cavity, and an insulating layer is provided between the inner wall of the cavity and the nut 112.

[0077] like Figure 6As shown, the mounting post 111 is connected to the lower battery housing 11 by integral molding or welding.

[0078] like Figure 6 As shown, the lower battery housing 11 is connected to the baffle frame 12 by integral molding or welding.

[0079] In some embodiments of the present invention, the insulating layer is an elastic insulator, such as one made of high-performance engineering plastics (e.g., PA66+GF30 or similar materials). As an elastomer, this insulating layer effectively absorbs and attenuates high-frequency vibrations from the vehicle's road surface, preventing direct and rigid transmission of vibrations to the battery module. The insulating layer also provides electrical insulation between the fasteners and the lower battery housing 11, preventing electrochemical corrosion and potential short-circuit risks. Furthermore, the overmolding process ensures a firm bond between the mounting post 111 and the lower battery housing 11, avoiding the risk of loosening associated with traditional press-fit mounting posts 111.

[0080] like Figures 3-6 As shown, the axial height of each of the mounting posts 111 is the same, and their top surfaces are coplanar on the same horizontal plane, which can maintain the installation level of the battery cell module fixing structure 2.

[0081] like Figure 7 As shown, the battery cell module fixing structure 2 includes:

[0082] The battery cell module mounting bracket 21 includes a pair of parallel end clamping plates 211 and a peripheral connecting rod 212, which together form a battery cell module mounting cavity for accommodating and positioning the battery cell module; and

[0083] The connecting structure 22 is disposed on the side of the cell module fixing frame 21. The connecting wing plate 221 disposed thereon is parallel to the upper surface of the lower battery housing 11 and has a through hole 222. The position and size of the through hole 222 correspond one-to-one with the axial through cavity of the mounting post 111, which is used to realize the rapid positioning and fixing of the cell module fixing structure 2 and the lower battery housing 11.

[0084] like Figure 7 As shown, the connecting structure 22 is a T-shaped sheet metal part, which is integrally formed by a vertical connecting plate 223 and a connecting wing plate 221. The vertical connecting plate 223 and the connecting wing plate 221 are perpendicular to each other. The vertical connecting plate 223 is fixedly installed on the baffle frame 12. The connecting wing plate 221 is horizontal and is used to connect or position with other components in the horizontal direction. Through the structural design of integrally formed sheet metal parts, both connection stability and processing convenience are taken into account. The connecting structure 22 is a sheet metal part, which can greatly enhance its local rigidity and provide a solid and flat force-bearing surface for subsequent fastening.

[0085] like Figures 8-11As shown, the anti-loosening fixing structure 3 includes:

[0086] The self-locking anti-loosening component 31 includes a pair of stacked washers 311 facing each other. The opposite sides of the pair of washers 311 are respectively provided with a meshing surface and a bearing surface. The meshing surface is provided with a ramp-type serration 312, and the two washers 311 mesh with each other through the ramp-type serration 312. The bearing surface is machined with anti-slip teeth 313.

[0087] Fastener 32, which passes through the corresponding through hole 222 and axial through cavity in sequence, and is threadedly connected to nut 112, is used to achieve anti-loosening locking between battery lower housing 11 and cell module fixing structure 2.

[0088] like Figures 9-11 As shown, the meshing surface is an annular surface. Based on the annular surface, it extends in a spiral shape along its circumference to form a spiral trajectory. On the spiral trajectory, multiple sloping saw teeth 312 are divided by the height difference. Each sloping saw tooth 312 is distributed along the spiral line, and finally forms a spiral stepped structure on the annular surface.

[0089] In some embodiments of this application, the slope of the ramp-shaped sawtooth 312 is greater than the helix angle. When two washers 311 are stacked facing each other, the ramp-shaped sawtooth 312 of the two washers 311 mesh with each other to form an "interlocking" structure. This interlocking relationship can effectively limit the relative rotation between the washers 311 and block the initial force of loosening from the structural level, which is the physical basis for the "wedge effect".

[0090] This invention achieves the connection between the battery lower casing 11 and the cell module fixing structure 2 through the anti-loosening fixing structure 3. When the entire system is subjected to external vibration, and the fastener 32 exhibits a slight tendency to loosen and rotate, because the sloping serrations 312 of the meshing surface of the washer 311 are greater than the thread helix angle, this tendency will force the sloping serrations 312 of the two washers 311 to slide relative to each other and generate radial expansion, which is the "wedge effect". This effect will convert the rotational tendency of the fastener 32 into a huge locking force between the washers 311, thus acting like a "mechanical lock" to firmly lock the fastener 32 (such as bolts) in its current position and prevent any further loosening.

[0091] like Figures 8-11 As shown, each of the ramp-type saw teeth 312 is wedge-shaped, comprising a first inclined surface 3121 and a first transition surface 3122 connecting the first inclined surface 3121, wherein:

[0092] The first inclined surface 3121 has a first connecting edge 3123 and a second connecting edge 3124 arranged radially. The first connecting edge 3123 is connected to the first transition surface 3122 of the inclined saw tooth 312, and the second connecting edge 3124 is connected to the first transition surface 3122 of the adjacent inclined saw tooth 312. The distance from the first connecting edge 3123 to the horizontal plane where the meshing surface is located exceeds the distance from the second connecting edge 3124 to the horizontal plane where the meshing surface is located.

[0093] In some embodiments of this application, the slope of the ramp-type saw teeth 312 is 8-30°.

[0094] like Figures 8-11 As shown, the bearing surface is an annular surface. Based on the bearing surface, it extends in a spiral shape along its circumference to form a spiral trajectory. On the spiral trajectory, multiple anti-slip teeth 313 are divided by the height difference. Each anti-slip tooth 313 is distributed along the spiral line, and finally forms a spiral stepped structure on the annular surface.

[0095] like Figures 8-11 As shown, the anti-slip teeth 313 are distributed radially or in a stepped pattern on the bearing surface, forming a sawtooth pattern, which is used to distribute axial load and prevent the washer 311 from sliding relative to each other under vibration or impact. When the washer 311 is subjected to external force (such as vibration or impact), the anti-slip teeth 313 increase the friction of the contact surface, further suppressing the relative sliding between the washer 311 and the contacting parts (such as the connecting wing plate 221, fastener 32, etc.), thus strengthening the anti-loosening effect from the friction level.

[0096] like Figures 8-11 As shown, the anti-slip tooth 313 is wedge-shaped, comprising a second inclined surface 3131 and a second transition surface 3132 connecting the second inclined surface 3131, wherein:

[0097] The second inclined surface 3131 has a first edge 3133 and a second edge 3134 arranged radially. The first edge 3133 is connected to the second transition surface 3132 of the anti-slip tooth 313, and the second edge 3134 is connected to the second transition surface 3132 of the adjacent anti-slip tooth 313. The distance from the first edge 3133 to the horizontal plane where the bearing surface is located exceeds the distance from the second edge 3134 to the horizontal plane where the bearing surface is located.

[0098] In some embodiments of this application, the inclination angle of the second inclined surface 3131 should be controlled between 8° and 30°. If the angle is too small, the wedging effect will be insignificant and the anti-loosening ability will decrease; if the angle is too large, it may be difficult to generate sufficient radial force between the meshing surfaces of the washers, or even affect normal tightening.

[0099] like Figures 8-11 As shown, the slope length of the first inclined plane 3121 is 1 to 3 times the slope length of the second inclined plane 3131. More preferably, it is 2 times.

[0100] like Figures 8-11 As shown, the first transition surface 3122 and the second transition surface 3132 are both arranged along the thickness direction of the gasket 311, and the first transition surface 3122 and at least one second transition surface 3132 are coplanar in the thickness direction of the gasket 311.

[0101] This invention optimizes the locking force and stress dispersion of fastener 32 from three aspects: "structural layering, functional difference, and directional complementarity" through the synergistic design of ramp-type saw teeth 312 and anti-slip teeth 313. The ramp-type saw teeth 312 include a first ramp surface 3121 and a first transition surface 3122 connecting the first ramp surface 3121. The first ramp surface 3121 serves as the "meshing surface" and undertakes the function of preventing misalignment. The first transition surface 3122 serves as the "connecting surface" and connects adjacent ramp-type saw teeth 312, ensuring the continuity of the overall structure and forming a basic load-bearing structure of "ramps-transition surfaces". The spatial misalignment / force difference between the saw teeth is achieved through the height difference between the first connecting edge 3123 and the second connecting edge 3124, which converts the rotational tendency of the fastener 32 into a huge locking force between the washers 311, thereby achieving anti-slip between the two washers 311. The anti-slip tooth 313 includes a second ramp surface 3131 and a second transition surface 3132 connecting the second ramp surface 3131, forming a basic load-bearing structure of "ramps-transition surfaces". It can also be achieved through the height difference between the first connecting edge 3123 and the second connecting edge 3124. 133. The height difference of the second edge 3134 achieves spatial misalignment / stress difference between the anti-slip teeth 313. Moreover, the first inclined surface 3121 of the ramp-type sawtooth 312 and the second inclined surface 3131 of the anti-slip tooth 313 have opposite inclination directions. The advantages are: enhanced spatial misalignment: the opposite inclined surface design makes the spatial misalignment of the ramp-type sawtooth 312 / anti-slip tooth 313 more significant, avoiding structural "overlap" or "synchronous stress", and improving the rationality of the overall layout; amplified stress difference: the opposite inclined surface combined with the height difference makes the stress of the ramp-type sawtooth 312 / anti-slip tooth 313 more dispersed, further optimizing functional efficiency; upgraded stress dispersion: the opposite inclined surface design can more evenly disperse stress (such as the impact force when the washer 311 rotates, the lateral force when the anti-slip tooth 313 bites), reducing the risk of local stress concentration. This invention achieves efficient conversion of the fastener 32's locking force and full dispersion of stress through a triple design of "slope-type saw teeth 312 and anti-slip teeth 313 with structural layering, height difference misalignment, and complementary directions," thereby improving the overall technical performance.

[0102] The present invention also provides an assembly method for the cell PACK anti-loosening fixing device, comprising the following steps:

[0103] Step 1, Pre-assembly: Place the two washers 311 of the self-locking anti-loosening component 31 onto the upper surface of the connecting wing plate 221 of the cell module fixing structure 2 after they are aligned with the meshing surfaces, so that the anti-slip surface of the lower washer 311 contacts the connecting wing plate 221.

[0104] Step 2, Positioning: Place the battery cell module fixing structure 2 with the battery module installed on the lower battery housing 11, so that the mounting post 111 passes through the through hole 222 on the connecting wing plate 221 and the inner hole of the self-locking anti-loosening component 31 in sequence.

[0105] Step 3, Tightening: After passing through the inner hole and through hole 222 of the self-locking anti-loosening component 31, the fastener 32 is screwed into the axial through cavity and threadedly connected to the nut 112 in the mounting column 111. The anti-slip surface of the washer 311 is pressed against the upper surface of the connecting wing plate 221 and the bearing surface of the fastener 32. The assembly is complete.

[0106] like Figure 12 As shown, the present invention also provides a start-stop battery PACK, which includes a cell PACK anti-loosening fixing device.

[0107] like Figure 14 As shown, the present invention also provides an assembly process for a start-stop battery pack, comprising the following steps:

[0108] 1. First Phase: Preparation of Individual Battery Cells

[0109] (1) Cell appearance inspection: Soft-pack cells are automatically fed into the production line.

[0110] Machine vision systems inspect battery cells for defects such as scratches, dents, misaligned tabs, leakage, and intact packaging edges. This may include dimensional checks to ensure cell thickness and length are within tolerances, guaranteeing smooth subsequent stacking and module compactness.

[0111] (2) Voltage and internal resistance sorting: The open circuit voltage (OCV) and internal resistance (IR) of each cell are accurately measured. Based on the test results, the cells are precisely grouped to ensure that the core parameters such as voltage and internal resistance of cells within the same module are highly consistent. This is the absolute foundation for ensuring the battery pack's lifespan, power performance, and safety.

[0112] 2. Second stage: Cell assembly

[0113] (1) Cell stacking: The sorted cells are stacked in sequence. Thermal pads or insulating films are often placed between the cells for heat dissipation and insulation.

[0114] (2) Electrode welding: Using ultrasonic welding or laser welding technology, the electrodes of a single cell are welded into series or parallel connecting pieces (Busbar).

[0115] (3) Install the acquisition harness: Install the voltage and temperature acquisition harness (such as FPC flexible circuit board) and reliably connect it to the voltage acquisition point and temperature sensor (NTC).

[0116] (4) Molding and Glue Pouring: Place the battery cells into the battery cell module fixing structure, put the washers on the fasteners (such as bolts), tighten them, and pour in the thermally conductive glue. After the glue cures, it plays a role in structural fixation, efficient heat conduction, and insulation protection.

[0117] (5) Module testing: 100% inspection of the assembled positioning cell module, including insulation resistance test, voltage and resistance test, etc., to ensure that the module performance and safety meet the standards.

[0118] (6) Qualified modules are taken offline: Qualified modules that have passed all tests are taken offline and are waiting to be sent to the final assembly line or used as spare parts.

[0119] The above embodiments are for illustrating the implementation schemes disclosed in this application and should not be construed as limiting this application. Furthermore, various modifications listed herein, as well as variations in methods and compositions of the invention, will be apparent to those skilled in the art without departing from the scope and spirit of this application. Although this application has been specifically described in conjunction with various specific preferred embodiments, it should be understood that this application should not be limited to these specific embodiments. In fact, various modifications as described above that are obvious to those skilled in the art to obtain the invention should be included within the scope of this application.

Claims

1. An anti-loosening fixing device for a battery cell PACK, characterized by, The application relates to a battery cell module fixing structure and a battery cell module fixing method. The application relates to a battery cell module fixing structure and a battery cell module fixing method. The application relates to a battery cell module fixing structure and a battery cell module fixing method. The application relates to a battery cell module fixing structure and a battery cell module fixing method.

2. The cell PACK anti-loosening fixing device according to claim 1, characterized in that, The application relates to a battery cell module fixing structure and a battery cell module fixing method.

3. The cell PACK anti-loosening fixing device according to claim 1, characterized in that, The application relates to a battery cell module fixing structure and a battery cell module fixing method. The application relates to a battery cell module fixing structure and a battery cell module fixing method. The application relates to a battery cell module fixing structure and a battery cell module fixing method.

4. The cell PACK anti-loosening fixing device according to claim 2, characterized in that, The application relates to a battery cell module fixing structure and a battery cell module fixing method. The application relates to a battery cell module fixing structure and a battery cell module fixing method. The application relates to a battery cell module fixing structure and a battery cell module fixing method.

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The height of the first connecting edge (3123) exceeds that of the second connecting edge (3124).

6. The electric cell PACK anti-loosening fixing device according to claim 4, characterized in that, The slope of the sloping saw teeth (312) is greater than the thread helix angle, which is 8-30°.

7. The electric cell PACK anti-loosening fixing device according to claim 4, characterized in that, The anti-slip teeth (313) are radially distributed on the bearing surface to form a sawtooth pattern, which is used to disperse axial load and prevent the washer (311) from sliding relative to each other under vibration or impact.

8. The electric cell PACK anti-loosening fixing device according to claim 7, characterized in that, The anti-slip tooth (313) is wedge-shaped and includes a second inclined surface (3131) and a second transition surface (3132) connecting the second inclined surface (3131). The second inclined surface (3131) has a first edge (3133) and a second edge (3134) arranged radially. The first edge (3133) is connected to the upper edge of the second transition surface (3132) of the anti-slip tooth (313). The second edge (3134) is connected to the lower edge of the second transition surface (3132) of the adjacent anti-slip tooth (313). The distance from the first edge (3133) to the horizontal plane where the bearing surface is located exceeds the distance from the second edge (3134) to the horizontal plane where the bearing surface is located.

9. The assembling method of the anti-loosening fixing device for the battery cell PACK according to any one of claims 1 to 8, characterized in that, include: Step 1, Pre-assembly: Place the two washers (311) of the self-locking anti-loosening component (31) on the upper surface of the connecting wing plate (221) of the battery cell module fixing structure (2) after the two washers (311) of the self-locking anti-loosening component (31) are in contact with each other with their meshing surfaces (3111), so that the anti-slip surface of the lower washer (311) contacts the connecting wing plate (221). Step 2, Positioning: Place the battery cell module fixing structure (2) with the battery module installed on the lower battery housing (11), so that the mounting post (111) passes through the through hole (222) on the connecting wing plate (221) and the inner hole of the self-locking anti-loosening component (31) in sequence; Step 3, Tightening: After passing the fastener (32) through the inner hole and through hole (222) of the self-locking anti-loosening component (31), screw it into the axial through cavity and connect it with the nut in the mounting column (111) by thread. Keep the anti-slip surface of the washer (311) pressing against the upper surface of the connecting wing plate (221) and the bearing surface of the fastener (32). The assembly is complete.

10. A start-stop battery PACK, characterized by, It includes the cell PACK anti-loosening fixing device according to any one of claims 1 to 8.

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