Automobile carbon fiber underbody shield
Patent Information
- Application Number
- CN202522132525.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-09
- Publication Date
- 2026-08-28
- Estimated Expiration
- 2035-10-09
AI Technical Summary
[0004]为了解决传统碳纤维复合材料原材料及铺层成本高昂，模压固化周期时间长的问题，以及制品韧性不足容易脆断，在成型过程中经常出现缺胶的缺陷，本实用新型提供一种汽车碳纤维底护板，本实用新型解决上述问题所采用的技术方案是：一种汽车碳纤维底护板，所述碳纤维底护板铺层结构为五层铺层结构，沿厚度方向从上到下依次为保护膜、碳纤维层、非金属增强材料层、UD碳纤维预浸料层和保护膜，其中第一层和第五层的保护膜采用保护膜一体化集成设计
[0010]如上所述，本实用新型所提供了一种汽车碳纤维底护板的有益效果是：本实用新型采用碳纤维、玻璃纤维或碳纤维SMC等轻质材料，配合五层复合结构的精准设计，整体重量较传统铝合金护板降低30%～50%，轻量化直接减少车身负荷，可使新能源汽车续航里程提升5%～8%，而碳纤维层、UD碳纤维预浸料层和非金属增强材料层的协同增强，底护板的抗冲击性、抗弯曲性、抗撕裂性全面优于传统材料，外层保护膜具有耐高温性和耐刮擦性，具有较长的使用寿命且能大幅降低维护更换频率，对碳纤维层不同的丝束规格、不同织法和非金属增强材料层的选用，可以灵活调整产品的性能，适配不同的车型，提升产品的通用性。
Smart Images
Figure CN224690119U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of carbon fiber composite material products, and in particular to a carbon fiber underbody protection plate for automobiles. Background Technology
[0002] Carbon fiber composites are structural materials made by combining carbon fiber as the reinforcement with a matrix of resin, ceramics, and metals. They are among the most advanced composite materials in the world today, possessing a variety of excellent properties such as high strength, light weight, high temperature resistance, and corrosion resistance. They have been widely used in aerospace, shipbuilding, automobile manufacturing, and military industries. With the rapid development of new energy vehicles, their market share and vehicle ownership are gradually increasing. Therefore, the chassis of new energy vehicles that house battery packs have increasingly higher requirements for protection, and carbon fiber composite underbody plates provide a solution for this.
[0003] Traditional carbon fiber composites often employ a multilayer structure of "carbon fiber + UD prepreg + glass fiber." While these carbon fiber products possess high strength, they also suffer from significant drawbacks: high raw material and layup costs, molding and curing cycles exceeding one hour, and low production efficiency. Furthermore, the products lack toughness and are prone to brittle fracture, and defects such as insufficient adhesive during molding often result in poor surface quality, requiring subsequent coating to compensate. These factors collectively restrict their large-scale industrial application. Utility Model Content
[0004] To address the issues of high raw material and layup costs, long molding and curing cycles, insufficient toughness and brittleness of traditional carbon fiber composite materials, and frequent defects such as insufficient adhesive during molding, this invention provides a carbon fiber underbody protection plate for automobiles. The technical solution adopted by this invention to solve the above problems is: a carbon fiber underbody protection plate for automobiles, wherein the carbon fiber underbody protection plate has a five-layer layup structure, which consists of a protective film, a carbon fiber layer, a non-metallic reinforcing material layer, a UD carbon fiber prepreg layer, and a protective film in the thickness direction from top to bottom. The protective films of the first and fifth layers adopt an integrated design.
[0005] The aforementioned automotive carbon fiber underbody protection plate can be equipped with carbon fiber tows of 1K, 3K, 6K, 12K, 18K, or 24K specifications, and can provide any of the plain weave, twill weave, and forged weave patterns. The carbon fiber layer is formed by stacking 2 to 4 layers of fabric. Different vehicle models and different protected parts have different requirements for the mechanical properties and appearance precision of the underbody protection plate. The corresponding parameters can be selected according to the specific protection requirements. Among them, 1K means that the number of monofilaments in a single bundle of carbon fiber is 1000. The finer the bundle, the more delicate the fabric surface and the higher the flatness, which is suitable for parts with high appearance precision requirements. The thicker the bundle, the higher the carbon fiber density per unit area, and the better the impact resistance and tear resistance of the product, which is suitable for parts with high protection strength requirements.
[0006] The aforementioned automotive carbon fiber underbody protection plate, wherein the carbon fiber layer is a layer formed by resin impregnation and curing of carbon fiber fabric. The resin content after impregnation is controlled between 30% and 45%, and the interlaminar shear strength of the cured carbon fiber layer is ≥40 MPa. The resin content is a core indicator of the ratio of resin to fiber in carbon fiber composite materials. The resin content range of 30% to 45% ensures that the resin fully encapsulates the carbon fiber and maximizes the high strength characteristics of the carbon fiber, achieving a balance between strength and weight control. This meets the dual requirements of lightweight and high protective strength for automotive underbody protection plates. Interlaminar shear strength is a key indicator for measuring the ability of composite material interlaminars to resist shear failure. An interlaminar shear strength of ≥40 MPa ensures that the carbon fiber layer maintains structural integrity under complex working conditions, effectively transfers and disperses stress, and improves the safety redundancy and service life of the product.
[0007] The aforementioned automotive carbon fiber underbody protection plate, wherein the non-metallic reinforcing material layer is a glass fiber layer or a carbon fiber SMC layer. If it is a glass fiber layer, alkali-free glass fiber is selected; if it is a carbon fiber SMC layer, the carbon fiber length is 25-50mm, and the flexural modulus is ≥15GPa. The alkali-free glass fiber layer has better corrosion resistance, insulation and mechanical stability than the alkali-containing glass fiber. The carbon fiber SMC layer is a composite material made by mixing and pressing short carbon fibers with resin, which has the advantages of high molding efficiency and strong shape adaptability. The fiber length range of 25-50mm can ensure that the fibers are evenly dispersed and form a continuous reinforcing network. The flexural modulus ≥15GPa can ensure that the carbon fiber SMC layer is not easily bent and deformed when subjected to road impact, providing rigid support for the underbody protection plate, which is suitable for core parts with high strength requirements.
[0008] The aforementioned automotive carbon fiber underbody protection plate, wherein the UD carbon fiber prepreg layer is composed of a thermoplastic resin matrix and high-strength carbon fiber reinforcement material, wherein the volume content of high-strength carbon fiber accounts for 55% to 65% of the total volume of the UD carbon fiber prepreg layer. The UD carbon fiber prepreg layer is the core reinforcement layer of the underbody protection plate that bears directional stress. Compared with traditional thermosetting resins, thermoplastic resins have sliding molecular chains and can absorb energy through deformation when impacted, avoiding brittle fracture of the UD layer, and have better toughness and impact resistance. Thermoplastic resins can be reheated and recast, facilitating production. The recycled materials after the product is scrapped contain high-strength carbon fiber, which accounts for 55% to 65% of the total volume of the UD carbon fiber prepreg layer. This ensures that the carbon fiber forms a continuous directional reinforcement network and that the resin fully encapsulates the fiber, so that the longitudinal tensile strength of the UD layer can reach more than 1500MPa. This perfectly matches the protection requirements of the bottom plate in bearing the main stress direction. The unidirectional arrangement of the UD carbon fiber prepreg layer enhances the longitudinal stress resistance. Combined with the multidirectional weave of the upper carbon fiber layer that can resist transverse and longitudinal stress and the lower protective film, the overall mechanical properties of the product are improved.
[0009] The aforementioned automotive carbon fiber underbody protection plate uses a PET or PP film as the protective film, with a thickness of 0.05–0.2 mm, a temperature resistance of not less than 150°C, a surface tension of ≥38 mN / m, and a peel strength of ≥5 N / cm between the protective film and adjacent carbon fiber layers and UD carbon fiber prepreg layers. PET film has excellent scratch resistance, chemical corrosion resistance, and dimensional stability, while PP film has better flexibility, lower cost, and excellent low-temperature resistance, making it suitable for vehicles in cold regions. The 0.05–0.2 mm range design ensures that the film has sufficient tear resistance to effectively resist daily scratches. The temperature resistance of ≥150°C meets the requirements of the hot pressing process in production and the operating conditions during vehicle operation. The surface tension of ≥38 mN / m ensures good wetting and adhesion between adjacent layers, avoiding air bubbles or gaps between layers. The peel strength of ≥5 N / cm ensures a lasting bond between layers and resists vibrations during operation.
[0010] As described above, the beneficial effects of the carbon fiber underbody protection plate provided by this utility model are as follows: This utility model uses lightweight materials such as carbon fiber, glass fiber, or carbon fiber SMC, combined with a precise design of a five-layer composite structure, reducing the overall weight by 30% to 50% compared to traditional aluminum alloy underbody protection plates. This lightweighting directly reduces the vehicle body load, which can increase the driving range of new energy vehicles by 5% to 8%. The synergistic reinforcement of the carbon fiber layer, the UD carbon fiber prepreg layer, and the non-metallic reinforcement material layer makes the underbody protection plate superior to traditional materials in terms of impact resistance, bending resistance, and tear resistance. The outer protective film has high temperature resistance and scratch resistance, has a long service life, and can significantly reduce the frequency of maintenance and replacement. By selecting different tow specifications, different weaving methods, and non-metallic reinforcement material layers for the carbon fiber layer, the performance of the product can be flexibly adjusted to adapt to different vehicle models, thus improving the product's versatility. Attached Figure Description
[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0012] Figure 1 This is a schematic diagram of the overall design of this utility model; Figure 2 This is an exploded view of the present invention; Figure 3 This is an exploded view of another option of this utility model; Figure 4 This is a partial sectional view of the present invention.
[0013] Summary of figure labels and their descriptions: 1. Protective film, 2. Carbon fiber layer, 3. Non-metallic reinforcing material layer, 31. Glass fiber layer, 32. Carbon fiber SMC layer, 4. UD carbon fiber prepreg layer. Detailed Implementation
[0014] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.
[0015] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. When a component is said to be "set on" another component, it can be directly set on the other component or there may be an intervening component.
[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
[0017] Please see Figure 1 and Figure 2 A carbon fiber underbody protection plate for automobiles has a five-layer ply structure. From top to bottom along the thickness direction, the layers are a protective film 1, a carbon fiber layer 2, a non-metallic reinforcing material layer 3, a UD carbon fiber prepreg layer 4, and a protective film 1. The first and fifth protective films 1 are integrated into one piece. The five-layer ply structure is composited into one piece through a hot pressing molding process.
[0018] Please see Figure 2 The carbon fiber layer 2 can be equipped with carbon fiber tows of 1K, 3K, 6K, 12K, 18K or 24K specifications, and can be provided with any of the plain weave, twill weave and forged weave patterns. The carbon fiber layer 2 is formed by stacking 2 to 4 layers of fabric. Different vehicle models and different protected parts have different requirements for the mechanical properties and appearance precision of the underbody protection plate. The corresponding parameters can be selected according to the specific protection requirements. Among them, 1K means that the number of single carbon fiber filaments in a single bundle is 1000. The finer the bundle, the more delicate the fabric surface and the higher the flatness, which is suitable for parts with high appearance precision requirements. The thicker the bundle, the higher the carbon fiber density per unit area, and the better the impact resistance and tear resistance of the product, which is suitable for parts with high protection strength requirements.
[0019] Please see Figure 4Carbon fiber layer 2 is a layer formed by impregnating and curing carbon fiber fabric with resin. The resin content after impregnation is controlled between 30% and 45%. After curing, the interlaminar shear strength of carbon fiber layer 2 is ≥40 MPa. The resin content is the core indicator of the ratio of resin to fiber in carbon fiber composite materials. The resin content range of 30% to 45% can ensure that the resin fully encapsulates the carbon fiber and maximize the high strength characteristics of the carbon fiber, achieving a balance between strength and weight control. This meets the dual requirements of lightweight and high protective strength for automotive underbody protection plates. Interlaminar shear strength is a key indicator for measuring the ability of composite materials to resist shear failure between layers. An interlaminar shear strength of ≥40 MPa can ensure that carbon fiber layer 2 maintains structural integrity under complex working conditions, effectively transfers and disperses stress, and improves the safety redundancy and service life of the product.
[0020] Please see Figure 2 and Figure 3 The non-metallic reinforcing material layer 3 is either a glass fiber layer 31 or a carbon fiber SMC layer 32. If it is a glass fiber layer 31, alkali-free glass fiber is selected; if it is a carbon fiber SMC layer 32, the carbon fiber length is 25-50mm and the flexural modulus is ≥15GPa. The alkali-free glass fiber layer 31 has better corrosion resistance, insulation and mechanical stability than alkali glass fiber. The carbon fiber SMC layer 32 is a composite material made by mixing and pressing short carbon fibers with resin. It has the advantages of high molding efficiency and strong shape adaptability. The fiber length range of 25-50mm can ensure that the fibers are evenly dispersed and form a continuous reinforcing network. The flexural modulus ≥15GPa can ensure that the carbon fiber SMC layer 32 is not easily bent and deformed when subjected to road impact, providing rigid support for the bottom guard plate, which is suitable for core parts with high strength requirements.
[0021] Please see Figure 2 and Figure 4The UD carbon fiber prepreg layer 4 is composed of a thermoplastic resin matrix and high-strength carbon fiber reinforcement. The high-strength carbon fiber accounts for 55%–65% of the total volume of the UD carbon fiber prepreg layer 4. The UD carbon fiber prepreg layer 4 is the core reinforcement layer of the bottom liner that withstands directional stress. Compared to traditional thermosetting resins, thermoplastic resins have sliding molecular chains, allowing them to absorb energy through deformation upon impact, preventing brittle fracture of the UD layer and exhibiting superior toughness and impact resistance. Furthermore, thermoplastic resins can be reheated and recast, facilitating the removal of materials after product disposal. The high-strength carbon fiber accounts for 55% to 65% of the total volume of the UD carbon fiber prepreg layer 4. This ensures that the carbon fiber forms a continuous directional reinforcement network and that the resin fully encapsulates the fiber, enabling the longitudinal tensile strength of the UD layer to reach over 1500 MPa. This perfectly matches the protection requirements of the bottom plate in bearing the main stress directions. The unidirectional arrangement of the UD carbon fiber prepreg layer 4 enhances the longitudinal stress resistance. Combined with the multidirectional weaving of the upper carbon fiber layer 2, which can resist transverse and longitudinal stresses, and the lower protective film 1, it improves the overall mechanical properties of the product.
[0022] Please see Figure 1 The protective film 1 is made of PET film or PP film with a thickness of 0.05-0.2mm, a temperature resistance of ≥150℃, a surface tension of ≥38mN / m, and a peel strength of ≥5N / cm between the protective film 1 and the adjacent carbon fiber layer 2 and UD carbon fiber prepreg layer 4. PET film has excellent scratch resistance, chemical corrosion resistance and dimensional stability, while PP film has better flexibility, lower cost and excellent low temperature resistance, making it suitable for vehicles in cold regions. The 0.05-0.2mm range design can ensure that the film has sufficient tear resistance to effectively resist daily scratches. The temperature resistance of the protective film 1 of not less than 150℃ meets the requirements of the hot pressing process in production and the working conditions during vehicle operation. The surface tension of ≥38mN / m ensures good wetting and adhesion between adjacent layers, avoiding air bubbles or gaps between layers. The peel strength of ≥5N / cm can ensure a lasting bond between layers and resist vibration under working conditions.
[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.
Claims
1. A carbon fiber underbody protection plate for automobiles, characterized in that: The carbon fiber bottom protective plate has a five-layer ply structure, which consists of a protective film (1), a carbon fiber layer (2), a non-metallic reinforcing material layer (3), a UD carbon fiber prepreg layer (4), and a protective film (1) in the thickness direction from top to bottom. The first and fifth protective films (1) adopt an integrated design, and the five-layer ply structure is composited into one by a hot pressing molding process.
2. The automotive carbon fiber underbody protection plate according to claim 1, characterized in that: The carbon fiber layer (2) can be equipped with carbon fiber tows of 1K, 3K, 6K, 12K, 18K or 24K specifications, and can provide any one of plain weave, twill weave and forged weave, and the carbon fiber layer (2) is formed by stacking 2 to 4 layers of fabric.
3. The automotive carbon fiber underbody protection plate according to claim 2, characterized in that: The carbon fiber layer (2) is a layer formed by impregnating and curing carbon fiber fabric with resin. The resin content after impregnation is controlled at 30% to 45%, and the interlaminar shear strength of the carbon fiber layer (2) after curing is ≥40MPa.
4. The automotive carbon fiber underbody protection plate according to claim 1, characterized in that: The non-metallic reinforcing material layer (3) is a glass fiber layer (31) or a carbon fiber SMC layer (32). If it is a glass fiber layer (31), alkali-free glass fiber is selected; if it is a carbon fiber SMC layer (32), the carbon fiber length is 25-50mm and the bending modulus is ≥15GPa.
5. The automotive carbon fiber underbody protection plate according to claim 1, characterized in that: The UD carbon fiber prepreg layer (4) is composed of a thermoplastic resin matrix and high-strength carbon fiber reinforcement material, wherein the volume content of high-strength carbon fiber accounts for 55% to 65% of the total volume of the UD carbon fiber prepreg layer (4).
6. The automotive carbon fiber underbody protection plate according to claim 1, characterized in that: The protective film (1) is made of PET film or PP film with a thickness of 0.05 to 0.2 mm, a temperature resistance of ≥150℃, a surface tension of ≥38 mN / m, and a peel strength of ≥5 N / cm between the protective film (1) and the adjacent carbon fiber layer (2) and UD carbon fiber prepreg layer (4).