New energy battery box skin made of thermoplastic composite material

Abstract

According to the new energy battery box skin made of the thermoplastic composite material, high-performance continuous fibers and thermoplastic resin are pressed through a rolling assembly to form a multi-angle thickness-adjustable laminated plate, and the laminated plate is sequentially conveyed through a fiber bundle unwinding assembly and a resin unwinding assembly in a matched mode; and after fixed-size cutting, the materials are contained in a material containing box, and finally the skin is formed through a hot bending process. The continuous fiber is a filament glass fiber, and the unwinding assembly drives an unwinding roller through a servo motor and is matched with a guide adjusting roller to realize accurate alignment and tension control of a fiber bundle and a pre-impregnated thermoplastic resin film; the rolling assembly is integrated with a heating and cooling shaping device, and sufficient infiltration and size stability of materials are guaranteed. The structural strength, the corrosion resistance and the lightweight level of the battery box skin are improved, flexible thickness regulation and high-precision size control are achieved, and the battery box skin is suitable for complex working condition requirements of new energy automobiles and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of thermoplastic forming, and particularly relates to a new energy battery box skin made of thermoplastic composite material. BACKGROUND

[0002] As a key protective component of the battery pack, the new energy battery box skin directly affects the structural safety, lightweight level and environmental resistance of the battery system. Its performance requirements are becoming increasingly stringent as new energy vehicles develop towards long endurance, high safety and low energy consumption. At present, the new energy battery box skin of commercial vehicles and passenger vehicles generally adopts metal materials (such as cold-rolled steel sheets and aluminum alloy sheets) which are formed by stamping and then are surface-protected by electroplating or paint spraying processes to meet the basic structural support and corrosion protection requirements.

[0003] However, the traditional metal skin still has the following defects: the contradiction between weight and energy consumption is prominent: the density of metal materials is large (such as the density of steel is about 7.85 g / cm³ and the density of aluminum alloy is about 2.7 g / cm³), which leads to an increase in the overall weight of the battery box and directly affects the endurance mileage of the whole vehicle. Taking the battery box of a commercial vehicle as an example, the metal skin accounts for 15% to 20% of the total weight of the battery pack, becoming a key bottleneck restricting lightweight.

[0004] Therefore, developing a new energy battery box skin material and preparation process which has high strength, lightweight, corrosion resistance, flexible process and environmental protection has become a technical problem to be solved in the field. SUMMARY

[0005] To achieve the above-mentioned purpose, the present application provides a new energy battery box skin made of thermoplastic composite material, in which high-performance continuous fibers and thermoplastic resins are pressed by a roller assembly to form a laminated plate material with adjustable multi-angle thickness, the laminated plate material is cooperatively conveyed by a fiber bundle unwinding assembly and a resin unwinding assembly, and is then collected in a material container after being sized and cut by a cutting assembly; the thickness adjustment of the laminated plate material is realized by adjusting the roll gap of the roller assembly, and the material flowability of the laminated plate material is maintained by a temperature control system during the pressing process to ensure that the plate structure is dense and the performance is stable.

[0006] In an embodiment, the continuous fibers are long filament glass fibers.

[0007] In an embodiment, the resin unwinding assembly and the fiber bundle unwinding assembly have the same structure and each include three sets of unwinding rollers and one set of guide adjusting rollers, the unwinding rollers are driven by a servo motor, and the guide adjusting rollers are used to uniformly expand and guide the fiber bundle or resin film into the roller assembly.

[0008] In an embodiment, the resin unwinding assembly is wound with a pre-impregnated thermoplastic resin film, and the fiber bundle unwinding assembly is wound with a continuous fiber bundle, both of which are tension-adjusted and path-corrected by the guide adjustment roller during unwinding, ensuring accurate alignment and preliminary compounding of the fiber and resin before entering the rolling assembly.

[0009] In an embodiment, the rolling assembly includes two sets of pressure rollers arranged symmetrically above and below, the pressure rollers are provided with heating devices on the side away from the cutting assembly, and cooling and shaping devices on the other side, and the roll gap formed between the upper and lower pressure rollers is used to adjust the thickness of the laminated plate.

[0010] In an embodiment, the pressure rollers are driven by servo motors, and the pressure roller located on the upper side rotates clockwise, and the pressure roller located on the lower side rotates counterclockwise, both of which operate synchronously to continuously press the fiber and resin entering the roll gap.

[0011] In an embodiment, the cutting assembly includes a fixed frame, a cutting tool, and a positioning sensor, the fixed frame is used to support the cutting tool and ensure its running stability, the cutting tool is driven by a servo motor to cut to size, and the positioning sensor detects the conveying length of the laminated plate in real time and triggers the cutting action when the preset size is reached.

[0012] In an embodiment, the laminated plate is bent by a hot bending process with a CFRT raw material plate to form a battery box skin.

[0013] Compared with the prior art, the beneficial effects of the present application are: 1. Long filament glass fiber is used as high-performance continuous fiber, which has excellent tensile strength and corrosion resistance, and forms a composite system with thermoplastic resin, which can effectively improve the structural load-bearing capacity and fatigue resistance of the battery box skin, significantly prolonging the service life of the product. Compared with traditional metal materials, this composite structure can maintain stable performance under long-term complex working conditions (such as vibration, impact, temperature and humidity changes), reducing maintenance costs.

[0014] 2. The composite system of thermoplastic resin and long filament glass fiber greatly reduces the weight of the battery box skin (about 57.5% lighter than metal materials), and achieves a balance between "lightweight-high strength" performance through the synergistic effect between materials. In addition, the composite material has good weather resistance and dimensional stability, which can avoid the problems of metal materials such as rusting, thermal expansion and cold shrinkage deformation, and meets the harsh environmental requirements of new energy vehicle application scenarios.

[0015] 3. The roll assembly integrates heating device and cooling shaping device: the heating stage softens the thermoplastic resin to enhance the flowability, ensuring the sufficient combination of the fiber and resin interface; the cooling stage quickly shapes to lock the structure of the plate, improving the compactness and interface bonding strength of the composite material. This process makes the laminated plate not prone to delamination, cracking and other defects in long-term use, ensuring the structural stability and safety of the battery box skin. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0017] Fig. 1 A three-dimensional view of the new energy battery box skin made of thermoplastic composite material is provided in the present application; Fig. 2 A raw material production process diagram of the new energy battery box skin made of thermoplastic composite material is provided in the present application.

[0018] Explanation of reference signs: 1, resin unwinding assembly; 2, fiber bundle unwinding assembly; 3, roll assembly; 4, cutting assembly; 5, material container. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also belong to the scope of protection of the present application.

[0020] Reference Figs. 1-2 As shown in the present application, the new energy battery box skin made of thermoplastic composite material comprises: a multi-angle thickness adjustable laminated plate formed by pressing high performance continuous fiber and thermoplastic resin through a roll assembly 3, the laminated plate is sequentially conveyed through the cooperation of a fiber bundle unwinding assembly 2 and a resin unwinding assembly 1, and is stored in a material container 5 after being sized and cut by a cutting assembly 4; the thickness adjustment of the laminated plate is realized by adjusting the roll gap of the roll assembly 3, and the material flowability is maintained during the pressing process by a temperature control system, ensuring that the plate structure is dense and stable in performance.

[0021] In the production process, the fiber bundle unwinding assembly 2 and the resin unwinding assembly 1 work together to uniformly spread and deliver the fiber and resin to the rolling assembly 3. The rolling assembly 3 controls the gap distance and temperature during the pressing process to make the material fully infiltrate and achieve the required thickness. After pressing, the material is delivered to the cutting assembly 4 for cutting to size, ensuring that the size accuracy of the laminated plate meets the requirements of subsequent bending forming.

[0022] Optionally, the continuous fiber is a filament glass fiber. The continuous filament glass fiber has excellent tensile strength and corrosion resistance, which can effectively improve the structural strength and service life of the battery box skin. Compared with traditional metal materials, the composite system of filament glass fiber and thermoplastic resin not only greatly reduces the product weight, but also has good weather resistance and dimensional stability, which meets the long-term use requirements under complex working conditions.

[0023] Optionally, the resin unwinding assembly 1 and the fiber bundle unwinding assembly 2 have the same structure, both including three sets of unwinding rollers and a set of guide adjusting rollers. The unwinding rollers are driven by a servo motor, and the guide adjusting rollers are used to uniformly spread and guide the fiber bundle or resin film into the rolling assembly 3.

[0024] In this embodiment, the servo motor adjusts the speed of the unwinding roller according to the material tension requirement during the unwinding operation, ensuring that the fiber bundle and resin film maintain constant tension during the delivery process, avoiding wrinkles or breakage. At the same time, the guide adjusting roller can uniformly spread the fiber bundle and resin film and form a continuous and flat layer structure, providing a uniform material basis for subsequent rolling forming.

[0025] Optionally, the unwinding roller in the resin unwinding assembly 1 is wound with a pre-impregnated thermoplastic resin film, and the unwinding roller in the fiber bundle unwinding assembly 2 is wound with a continuous fiber bundle. Both of them are tension-adjusted and path-corrected by the guide adjusting roller during the unwinding process, ensuring that the fiber and resin are accurately aligned and preliminarily compounded before entering the rolling assembly.

[0026] Optionally, the rolling assembly includes two sets of pressure rollers arranged symmetrically above and below. The pressure rollers are provided with a heating device on the side away from the cutting assembly 4, and a cooling and shaping device on the other side. The gap formed between the upper and lower pressure rollers is used to adjust the thickness of the laminated plate. The pressure rollers are driven by a servo motor, and the pressure roller on the upper side rotates clockwise, and the pressure roller on the lower side rotates counterclockwise. Both of them operate synchronously to continuously press the fiber and resin entering the gap.

[0027] In this fact example, two groups of pressing rollers keep constant linear speed under the synchronous driving of servo motors, ensuring that the fibers and resin are fully combined during the pressing process, and at the same time, the thickness of the plate is controlled by adjusting the gap distance to meet the processing needs of the laminated plate. During the operation of the pressing roller, the heating device preheats and softens the fibers and resin, making them flow more easily and distribute uniformly during the pressing process, thereby improving the density and interfacial bonding strength of the composite material. The cooling and shaping device quickly cools the plate after hot pressing to ensure its shape stability and good dimensional accuracy.

[0028] Optionally, the cutting assembly 4 includes a fixed frame, a cutting tool, and a positioning sensor. The fixed frame is used to support the cutting tool and ensure its stable operation. The cutting tool is driven by a servo motor to perform size cutting. The positioning sensor detects the conveying length of the laminated plate in real time and triggers the cutting action when the preset size is reached.

[0029] In this embodiment, while completing the size cutting, the cutting assembly 4 realizes rapid reciprocating motion through high-precision servo motor driving the tool, ensuring that the cutting edge is smooth and free of burrs. During the cutting process, the positioning sensor and the control system work together to ensure cutting accuracy and repeatability, thereby improving the quality consistency of the finished plate.

[0030] Optionally, the laminated plate is bent after being subjected to the hot bending process with the CFRT raw material plate to form the battery box skin.

[0031] In this embodiment, after the laminated plate is subjected to the hot bending process with the CFRT raw material plate, a battery box skin with high structural strength and lightweight characteristics is formed. The formed battery box skin is fixed to the outside of the battery box bracket through M8 bolts to realize stable protection of the entire battery box.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that; it can still modify the technical solutions described in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A new energy battery box skin made of thermoplastic composite material, characterized in that: High-performance continuous fibers and thermoplastic resin are pressed into multi-angle thickness adjustable laminates by roller pressing assembly (3). The laminates are conveyed by fiber bundle unwinding assembly (2) and resin unwinding assembly (1) in sequence, and are cut to size by cutting assembly (4) and then stored in material box (5). The thickness of the laminates is adjusted by adjusting the roller gap of roller pressing assembly (3). During the pressing process, the material fluidity is maintained by temperature control system to ensure that the structure of the laminate is dense and the performance is stable.

2. The new energy battery box skin made of thermoplastic composite material according to claim 1, characterized in that: The continuous fiber is a long-filament glass fiber.

3. The new energy battery box skin made of thermoplastic composite material according to claim 1, characterized in that: The resin unwinding assembly (1) has the same structure as the fiber bundle unwinding assembly (2), both including three sets of unwinding rollers and one set of guide adjustment rollers. The unwinding rollers are driven by a servo motor, and the guide adjustment rollers are used to evenly unfold the fiber bundle or resin film and guide it into the roller pressing assembly (3).

4. The new energy battery box skin made of thermoplastic composite material according to claim 3, characterized in that: The unwinding roller in the resin unwinding assembly (1) is wound with a pre-impregnated thermoplastic resin film, while the unwinding roller in the fiber bundle unwinding assembly (2) is wound with a continuous fiber bundle. During the unwinding process, the tension of both is adjusted and the path is corrected by the guide adjustment roller to ensure that the fiber and resin are accurately aligned and initially compounded before entering the roller pressing assembly.

5. The new energy battery box skin made of thermoplastic composite material according to claim 1, characterized in that: The roller pressing assembly includes two sets of rollers arranged symmetrically on the upper and lower sides. A heating device is provided on the side of the rollers away from the cutting assembly (4), and a cooling and shaping device is provided on the other side. The gap formed between the upper and lower rollers is used to adjust the thickness of the laminate.

6. The new energy battery box skin made of thermoplastic composite material according to claim 5, characterized in that: The pressure rollers are driven by a servo motor, with the upper pressure roller rotating clockwise and the lower pressure roller rotating counterclockwise. The two operate synchronously to continuously press the fibers and resin entering the roller gap.

7. The new energy battery box skin made of thermoplastic composite material according to claim 1, characterized in that: The cutting assembly (4) includes a fixing frame, a cutting tool and a positioning sensor. The fixing frame is used to support the cutting tool and ensure its operational stability. The cutting tool performs fixed-size cutting under the drive of a servo motor. The positioning sensor detects the conveying length of the laminate in real time and triggers the cutting action when the preset size is reached.

8. The new energy battery box skin made of thermoplastic composite material according to any one of claims 1-7, characterized in that: The laminated sheet is formed into the battery box skin by bending it with CFRT raw material sheet through a hot bending process.

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