Fiber composite material and preparation method thereof, protective structural component and vehicle

Abstract

The present application discloses a fiber composite material and a preparation method thereof, a protective structural part and a vehicle. The fiber composite material includes: a resin matrix and a plurality of fiber layers. The resin matrix is ​​impregnated with the plurality of fiber layers by high-pressure resin transfer molding with the plurality of fiber layers. Thus, the resin and the plurality of fiber layers are prepared and molded by a high-pressure resin transfer molding process, and the fiber is coated with the resin matrix, so that the fiber composite material has good mechanical properties, good impact resistance, wear resistance, aging resistance, corrosion resistance and other advantages, which can meet the use requirements of vehicle anti-collision and wear resistance, and the fiber composite material does not need to be provided with a metal reinforcement structure, which can reduce the weight while ensuring the mechanical properties of the fiber composite material. At the same time, in the preparation process of the fiber composite material in the present application, the raw material utilization rate is high, the molding process is simple, the molding time and manufacturing cost can be reduced, and the production efficiency can be improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a fiber composite material and a preparation method thereof, a protective structural component and a vehicle. Background Art

[0002] Currently, protective structures in vehicles are mostly made of metal parts (such as metal plates, etc.), which results in a heavier weight of the vehicle.

[0003] In the related technologies, the composite materials used in vehicles are usually mainly fiber-reinforced thermosetting composite materials, which leads to high brittleness and poor impact resistance of the structural parts, limiting the use of composite structural parts in protective parts. At the same time, fiber-reinforced elastomer composite structural parts are mostly prepared by spraying first and then molding, which results in uneven resin mixing and high porosity, which is not conducive to improving the overall impact resistance of the material. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to provide a fiber composite material, which has high structural strength and good impact resistance.

[0005] The present application also provides a protective structural component.

[0006] The application also proposes a vehicle.

[0007] The application also provides a method for preparing the fiber composite material.

[0008] According to the fiber composite material of the first embodiment of the present application, the fiber composite material includes: a plurality of fiber layers; a resin matrix, wherein the resin matrix and the plurality of fiber layers are impregnated with the plurality of fiber layers by high pressure resin transfer molding.

[0009] In the present application, the resin and multiple fiber layers are prepared and molded through a high-pressure resin transfer molding process, and a resin matrix is ​​formed in the multiple fiber layers. The fiber composite material in the present application has good mechanical properties, good impact resistance, wear resistance, aging resistance, and corrosion resistance, which can meet the use requirements of vehicle anti-collision and wear resistance, and the fiber composite material does not need to be provided with a metal reinforcement structure, which can reduce the weight while ensuring the mechanical properties of the fiber composite material. At the same time, during the preparation process of the fiber composite material in the present application, the raw material utilization rate is high, the molding process is simple, the molding time and manufacturing cost can be reduced, and the production efficiency can be improved.

[0010] In some embodiments of the present application, the resin matrix is ​​impregnated with the plurality of fiber layers by high pressure resin transfer molding with a fiber preform composed of the plurality of fiber layers.

[0011] In some embodiments of the present application, the plurality of fiber layers are stacked.

[0012] In some embodiments of the present application, the fiber layer includes: a unidirectional fiber layer, the unidirectional fiber layer having a plurality of fibers extending in the same direction and arranged sequentially, and / or a fiber fabric layer, the fiber fabric layer having a plurality of fibers interlaced.

[0013] In some embodiments of the present application, the multiple fiber layers include multiple unidirectional fiber layers; wherein, the extension directions of the fibers in two adjacent unidirectional fiber layers are parallel to each other; and / or, in the projection of the stacking direction, the extension directions of the fibers in two adjacent unidirectional fiber layers have an angle, and the angle α satisfies the relationship: 45°≤α≤90°.

[0014] In some embodiments of the present application, the fiber composite material is provided with reinforcing ribs, and the reinforcing ribs are provided on the fiber layer located on the outermost side when stacked upward.

[0015] In some embodiments of the present application, the fiber composite material further includes a core layer, and in the stacking direction of the multiple fiber layers, the core layer is arranged between two of the fiber layers.

[0016] In some embodiments of the present application, the core layer is constructed as a foam structure.

[0017] In some embodiments of the present application, the foam structure includes at least one of polyethylene foam, balsa wood material, foam aluminum, polyurethane foam, polypropylene foam, and foam magnesium.

[0018] In some embodiments of the present application, the core layer is constructed as a lattice structure.

[0019] In some embodiments of the present application, the lattice structure is constructed as one of a honeycomb structure, a polygonal structure, a cross-shaped structure, and a polyhedron structure.

[0020] In some embodiments of the present application, the material of the lattice structure includes at least one of aluminum alloy, fiber reinforced composite material, aramid, polypropylene and ultra-high molecular weight polyethylene.

[0021] In some embodiments of the present application, the resin matrix is ​​made of an elastomeric resin material, and the elastomeric resin material includes: at least one of polyurethane, polyurea, semi-polyurea, silicone resin, and ethylene propylene rubber; and / or the fiber material in the fiber layer includes: at least one of carbon fiber, glass fiber, aramid fiber, basalt fiber, ultra-high molecular weight polyethylene fiber, and boron nitride fiber.

[0022] The protective structural component according to the second embodiment of the present application comprises an embedding component and the above-mentioned fiber composite material, wherein the embedding component is embedded in the multiple fiber layers along the stacking direction of the multiple fiber layers.

[0023] In some embodiments of the present application, the embedded part is configured as a metal part.

[0024] In some embodiments of the present application, the embedded component is provided with a connecting hole.

[0025] The vehicle according to the third aspect of the present application includes the above-mentioned fiber composite material or the above-mentioned protective structural component.

[0026] According to the method for preparing a fiber composite material of the fourth aspect embodiment of the present application, the fiber composite material includes a fiber preform and a resin matrix, and the preparation method includes: placing the fiber preform in a mold, and after the mold is closed and vacuumed, injecting resin material into the fiber preform, and forming the resin material and the fiber preform by high-pressure resin transfer molding.

[0027] In some embodiments of the present application, the injection pressure of the resin material is: 0-25 MPa; and / or, the injection time of the resin material is 5s-180s.

[0028] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 is a cross-sectional view of a fiber composite material according to a first embodiment of the present application;

[0031] Figure 2 is a cross-sectional view of a fiber composite material according to a second embodiment of the present application;

[0032] Figure 3 is a cross-sectional view of a fiber composite material according to a third embodiment of the present application;

[0033] Figure 4 is a cross-sectional view of a fiber preform according to an embodiment of the present application;

[0034] Figure 5 This is a schematic diagram of the fiber layer laying according to the embodiment of the present application. Figure 1 ;

[0035] Figure 6This is a schematic diagram of the fiber layer laying according to the embodiment of the present application. Figure 2 ;

[0036] Figure 7 This is a schematic diagram of the fiber layer laying according to the embodiment of the present application. Figure 3 ;

[0037] Figure 8 This is a schematic diagram of the fiber layer laying according to the embodiment of the present application. Figure 4 ;

[0038] Fig. 9 It is a schematic diagram of a fiber layer according to an embodiment of the present application.

[0039] Reference numerals:

[0040] Fiber composite material 100; protective structure 200; fiber preform 10;

[0041] Fabric layer 1; fiber 101; unidirectional fiber layer 11; fiber fabric layer 12;

[0042] Embedded part 2; connecting hole 21; core layer 3; reinforcing rib 4. DETAILED DESCRIPTION

[0043] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0044] Reference below Figure 1-Figure 9 A fiber composite material 100 according to an embodiment of the present application is described. The fiber composite material 100 in the present application is applied to a vehicle, and can be specifically constructed as a vehicle floor, a battery pack bottom guard plate, a battery pack side guard plate, a battery pack cover plate, a battery pack protective beam, a battery pack tray, a battery pack shell, an anti-collision beam (such as: front anti-collision beam, rear anti-collision beam), a bumper (front bumper, rear bumper), a trunk cover, a motor shell, a motor guard plate, pedals (such as: accelerator pedal, brake pedal, etc.) and energy absorption boxes and other structural parts in the vehicle that are susceptible to impact or wear.

[0045] The fiber composite material 100 according to the embodiment of the present application includes a resin matrix and a plurality of fiber layers 1 . The resin matrix impregnates the plurality of fiber layers 1 through high-pressure resin transfer molding with the plurality of fiber layers 1 .

[0046] Furthermore, multiple fiber layers 1 are stacked to form a fiber preform 10, and the resin matrix and the fiber preform 10 are impregnated with the multiple fiber layers 1 by high-pressure resin transfer molding, thereby obtaining a fiber composite material 100 with good impact resistance, wear resistance and aging resistance.

[0047] It is understood that the resin matrix is ​​a resin formed on the fiber preform 10 through a high-pressure resin transfer molding process. The resin impregnates the reinforcing fibers, and the resin is cured and formed after the resin fully impregnates the fibers. The fiber layer 1 refers to: a structural layer formed by fibers 101, which is not limited to a fiber structure composed of a single layer of fibers 101, but also includes a fiber structure formed by interlacing the fibers 101.

[0048] In the present application, a plurality of fiber layers 1 are first stacked to form a fiber preform 10, and a fiber composite material 100 is further formed by molding a resin and the fiber preform 10, so that the resin can fully infiltrate the fiber preform 10, improve the mechanical properties of the fiber composite material 100, and make the quality of the fiber composite material 100 easier to control.

[0049] Among them, the fiber composite material 100 of the present application is formed by a high pressure resin transfer molding (HP-RTM) process, and the resin is mixed and injected into the mold by high pressure. Under the action of high pressure, the resin can fully impregnate the fiber preform 10 located in the mold, and the fiber 101 in the fiber preform 10 is impregnated with the resin and coated with the fiber 101, thereby improving the mechanical properties of the fiber composite material 100. At the same time, when the fiber composite material 100 is prepared by the high pressure resin transfer molding process, there is basically no small molecule volatiles released during the molding process of the fiber composite material 100, which is environmentally friendly and environmentally friendly, and can improve the raw material utilization rate of the protective part, and the molding process is simple, which can reduce the molding time and manufacturing cost of the fiber composite material 100, and meet the needs of efficient batch production.

[0050] At present, the protective structures in vehicles are mostly made of metal parts (such as metal plates, etc.), which leads to a large weight of the vehicle. In related technologies, the composite materials used in vehicles are usually mainly fiber-reinforced thermosetting composite materials, which leads to high brittleness and poor impact resistance of the structural parts, limiting the use of composite structural parts in protective parts. At the same time, fiber-reinforced elastomer composite structural parts are mostly prepared by spraying first and then molding, which results in uneven resin mixing and high porosity, which is not conducive to improving the overall impact resistance of the material.

[0051] In the present application, multiple fiber layers 1 are stacked to form a fiber preform 10, and the resin and the fiber preform 10 are further prepared and molded by a high-pressure resin transfer molding process, the resin impregnates the fiber preform 10, and forms a resin matrix after curing. The fiber composite material 100 in the present application has good mechanical properties, good impact resistance, wear resistance, aging resistance, and corrosion resistance, which can meet the requirements of vehicle anti-collision and wear resistance, and the fiber composite material 100 does not need to be provided with a metal reinforcement structure, which can reduce the weight while ensuring the mechanical properties of the fiber composite material 100. At the same time, during the preparation process of the fiber composite material 100 in the present application, the raw material utilization rate is high, the molding process is simple, the molding time and manufacturing cost can be reduced, and the production efficiency can be improved.

[0052] In the present application, the fiber composite material 100 is formed by a high-pressure resin transfer molding process.

[0053] When the fiber preform 10 is arranged in the mold, the resin injection pressure is 0-25MPa (preferably 10MPa-25MPa). When the resin injection pressure reaches the above parameter range, the resin can be mixed evenly, the mold filling is faster, and the resin has a good effect of impregnating the fiber, which can significantly reduce bubbles and further reduce the porosity of the fiber composite material 100.

[0054] Furthermore, the resin injection time is 5s-180s (preferably 10s-30s).

[0055] The production and molding steps of the fiber composite material 100 in the present application are as follows: stacking multiple fiber layers 1 to form a fiber preform 10, arranging the fiber preform 10 in a mold, closing the mold and evacuating the mold, and injecting resin (such as two reactive components, such as isocyanate and amino compound) under pressure, allowing rapid reaction and polymerization, and continuing to maintain pressure so that the resin can fully infiltrate the fiber preform 10 under pressure, and finally curing and demolding to obtain the fiber composite material 100.

[0056] Compared with the prior art, the fiber composite material 100 in the present application is lighter and has better impact resistance and wear resistance.

[0057] The fiber preform 10 is formed by stacking a plurality of fiber layers 1 in sequence along a thickness direction, so that the fiber preform 10 is obtained by stacking the plurality of fiber layers 1 in layers.

[0058] like Figure 5 , Figure 6 and Figure 7As shown, in some embodiments of the present application, the fiber layer 1 includes: at least one of a unidirectional fiber layer 11 and a fiber fabric layer 12. The fiber preform 10 is formed by stacking at least one of the unidirectional fiber layer 11 and the fiber fabric layer 12. By stacking a plurality of fiber layers 1 (unidirectional fiber layers 11 or fiber fabric layers 12), the impact resistance of the fiber composite material 100 can be improved.

[0059] It should be understood that the fiber fabric layer 12 is a structural layer formed by weaving fibers 101 , wherein the fiber fabric layer 12 can be formed by weaving a plurality of fibers 101 , and the weaving method of the fiber fabric layer 12 is not specifically limited herein.

[0060] Reference Figure 5 , the fiber fabric layer 12 has a plurality of fibers 101 interwoven; Figure 6 The unidirectional fiber layer 11 has a plurality of fibers 101 extending in the same direction and arranged in sequence. The fiber fabric layer 12 is a structure formed by weaving the fibers 101.

[0061] It can be understood that due to the different arrangements of the fibers 101 in the fiber fabric layer 12 and the unidirectional tape, there are also differences in the way the fiber fabric layer 12 and the unidirectional fiber layer 11 transfer and buffer the force when subjected to impact force. Therefore, the fiber layer 1 can be configured as a fiber fabric layer 12 or a unidirectional fiber layer 11 according to the impact force buffering requirements to enhance the impact buffering effect of the fiber-fiber composite material 100.

[0062] Reference Figure 5 , the fiber preform 10 is formed by stacking multiple fiber fabric layers 12; Figure 6 , the fiber preform 10 is formed by stacking multiple unidirectional fiber layers 11; Figure 7 The fiber preform 10 is formed by stacking a fiber fabric layer 12 and a unidirectional fiber layer 11. Therefore, the fiber layer 1 can be arranged in a manner such that the fiber composite material 100 can improve its buffering effect against impact forces in different directions.

[0063] like Figure 6 As shown, in some embodiments of the present application, the fiber layer 1 includes a plurality of unidirectional fiber layers 11 , and the fiber preform 10 is formed by stacking and laying the plurality of unidirectional fiber layers 11 .

[0064] Reference Figure 6 In the plurality of unidirectional fiber layers 11, the extending directions of the fibers 101 in two adjacent unidirectional fiber layers 11 are parallel to each other. Figure 6 The fibers 101 of the unidirectional fiber layer 11 shown in FIG. 1 are arranged along the width direction (also Figure 6The fiber preform 10 is arranged in sequence along the length direction of the fiber preform 10, which can improve the impact resistance of the fiber preform 10.

[0065] Reference Figure 6 In the projection of the stacking direction, the extension directions of the fibers 101 in two adjacent unidirectional fiber layers 11 have an angle, and the angle α satisfies the relationship: 45°≤α≤90°.

[0066] in, Figure 6 The fibers 101 in the two unidirectional fiber layers 11 shown extend along the length direction and the width direction of the fiber preform 10 respectively, that is, the fibers 101 in the two stacked unidirectional fiber layers 11 are arranged perpendicular to each other, thereby improving the impact resistance of the fiber preform 10 in multiple directions.

[0067] It can be understood that the fiber preform 10 is usually arranged to be subjected to impact force in the direction of its thickness (i.e., the stacking direction of the fiber layer 1). Since the buffering effect of the unidirectional fiber layer 11 against impact forces in different directions is different, the arrangement of the fiber layer 1 can be designed according to the direction of the impact force that the fiber composite material 100 is susceptible to when used, so as to enhance the impact resistance of the fiber composite material 100.

[0068] like Figure 3 and Fig. 9 As shown, in some embodiments of the present application, the fiber composite material 100 is provided with reinforcing ribs 4, and the reinforcing ribs 4 are arranged on the outermost fiber layer 1 in the stacking direction, such as: the unidirectional fiber layer 11, the fiber fabric layer 12, so as to further improve the impact resistance of the fiber composite material 100.

[0069] like Figure 3 As shown, in some embodiments of the present application, taking the case where the reinforcing ribs 4 are arranged on the fiber fabric layer 12 as an example, in the stacking direction, at least one fiber fabric layer 12 is arranged on the outermost side of the multiple fiber layers 1, and the outer surface of the outermost fiber fabric layer 12 is provided with reinforcing ribs 4, so that the reinforcing ribs 4 are formed on the outer surface of the fiber composite material 100, thereby improving the impact resistance of the outer area of ​​the fiber composite material 100 and preventing interference between the reinforcing ribs 4 and other fiber layers 1, thereby facilitating the molding of the fiber preform 10.

[0070] like Fig. 9 As shown, in some embodiments of the present application, the fiber composite material 100 is provided with a plurality of reinforcing ribs 4, and the plurality of reinforcing ribs 4 are staggered to further enhance the strength of the fiber composite material 100. Optionally, the reinforcing ribs 4 are arranged perpendicular to each other, such as staggered in a "cross" shape.

[0071] like Figure 2 and Figure 8 As shown, in some embodiments of the present application, the fiber composite material 100 further includes a core layer 3, and in the stacking direction of the multiple fiber layers 1, the core layer 3 is arranged between two fiber layers 1, and the rigidity of the fiber composite material 100 can be improved by arranging the core layer 3. It can be understood that by arranging the core layer 3, the complex impact force can be better resisted, and the impact resistance of the fiber composite material 100 can be improved.

[0072] Reference Figure 2 and Figure 8 As shown, in the stacking direction of the fiber layers 1, the core layer 3 is arranged in the middle of the fiber preform 10, that is, fiber layers 1 are provided on both sides of the core layer 3 in the stacking direction, at least two fiber layers 1 are provided in the fiber preform 10, and the two fiber layers 1 are arranged on both sides of the core layer 3.

[0073] In some embodiments of the present application, the core layer 3 is configured as a foam structure. The foam structure has the advantages of light weight and high strength, which can improve the strength of the fiber composite material 100 while reducing the weight of the fiber composite material 100.

[0074] In a further embodiment of the present application, the foam structure includes at least one of polyethylene foam, balsa wood material (i.e., light wood), foamed aluminum, foamed magnesium, polypropylene foam, and polyurethane foam. That is, the foam structure can be made of one of polyethylene foam, balsa wood material (i.e., light wood), foamed aluminum, and polyurethane foam, or can be made of a combination of polyethylene foam, balsa wood material (i.e., light wood), foamed aluminum, and polyurethane foam, so that the foam structure has the advantages of high strength, good cushioning performance, easy molding, and light weight (low density).

[0075] In some other embodiments of the present application, the core layer 3 is constructed as a lattice structure, so as to ensure the structural strength of the core layer 3. The lattice structure includes a two-dimensional lattice structure and a three-dimensional lattice structure.

[0076] Furthermore, the lattice structure is constructed as one of a honeycomb structure, a polygonal structure, a cross-shaped structure, and a polyhedron structure. Figure 2 The lattice structure is constructed as a honeycomb structure, and the honeycomb structure reserves an installation area for arranging the embedded part 2.

[0077] In some embodiments of the present application, the material of the lattice structure includes at least one of aluminum alloy, fiber reinforced polymer / plastic (FRP), aramid, polypropylene and ultra-high molecular weight polyethylene. Among them, the FRP composite material is a high-performance material formed by mixing fiber material and matrix material (resin) in a certain proportion, so as to ensure the strength of the lattice structure.

[0078] It is understandable that the lattice structure can be made of the above materials, so as to ensure the strength of the lattice structure while preventing the weight of the lattice structure from being too high, thereby meeting the lightweight design requirements of the protective component. Among them, the core layer 3 can be composed of multiple lattice structures spliced ​​together.

[0079] In some embodiments of the present application, the resin matrix is ​​made of an elastomeric resin material, and the elastomeric resin material includes at least one of polyurethane, polyurea, semi-polyurea, silicone resin, and ethylene-propylene rubber.

[0080] It should be noted that the elastomeric resin material includes but is not limited to the above-mentioned materials.

[0081] Compared with the prior art that only uses resin materials (such as polyurethane, etc.) as the coating skin of the structural parts, the present application fully combines the resin matrix with the fiber preform 10 to improve the structural strength and impact resistance of the fiber composite material 100.

[0082] In some embodiments of the present application, the fiber material in the fiber layer 1 includes at least one of carbon fiber, glass fiber, aramid fiber, basalt fiber, ultra-high molecular weight polyethylene fiber, and boron nitride fiber.

[0083] Reference Figure 1 In a first embodiment of the present application, the fiber composite material 100 is configured as a battery pack underbody guard plate of a vehicle.

[0084] The multiple fiber layers 1 include unidirectional fiber layers 11 and fiber fabric layers 12 . The unidirectional fiber layers 11 and the fiber fabric layers 12 are mixed and laid, and embedded parts 2 (such as metal embedded parts) are pre-embedded in the multiple fiber layers 1 .

[0085] like Figure 1 As shown, there are six fiber layers 1, and the six fiber layers 1 include two fiber fabric layers 12 and four unidirectional fiber layers 11. The two fiber fabric layers 12 are arranged on both sides of the stacking direction, that is, the two fiber layers 1 on both sides of the up and down direction are fiber fabric layers 12, and the four unidirectional fiber layers 11 are stacked between the two fiber fabric layers 12, and the middle four unidirectional fiber layers 11 are arranged orthogonally.

[0086] The laying order of the six fiber layers 1 is: fiber fabric layer 12, unidirectional fiber layer 11 arranged at 90°, two unidirectional fiber layers 11 at 0°, unidirectional fiber layer 11 arranged at 90°, and fiber fabric layer 12.

[0087] Furthermore, the fiber layer 1 is stacked and cut into the shape of the battery pack bottom guard plate in the above order, and the cut fiber layer 1 pre-buries the embedded part 2 in the fiber layer 1 to obtain a fiber preform 10. After the fiber preform 10 is arranged in the mold, it is transferred to the molding equipment (such as: high pressure resin transfer molding (HR-RTM) machine), the mold is closed and vacuumed, and the two reaction components of isocyanate and amino compound are injected at a pressure of 10-25MPa. The injection of the reaction components can be completed in about 25 seconds, and the mixture is fully mixed and the polymerization reaction is completed in the mold cavity under vacuum. The pressure is continued to be maintained, and the resin (such as: polyurea resin) is fully impregnated with the fiber layer 1 under pressure and cured to obtain the battery pack bottom guard plate.

[0088] In the first embodiment, the fiber preform 10 adopts a mixed layer structure of a unidirectional fiber layer 11 and a fiber fabric layer 12, which can enhance the effect of the battery pack bottom guard plate in resisting complex impact forces, and uses the HP-RTM process to inject resin for molding, which can fully impregnate the fibers and better exert the advantages of the resin matrix when subjected to impact forces.

[0089] Specifically, the fiber fabric layer 12 is configured as a glass fiber cloth, and the unidirectional fiber layer 11 is configured as a glass fiber unidirectional tape.

[0090] Among them, the battery pack bottom protective plate in the first embodiment has a thickness of 4 mm, which can withstand 400J of energy without penetration in a drop hammer impact test, and the deformation on the battery pack bottom protective plate caused by the impact can be partially restored.

[0091] Reference Figure 2 In the second embodiment of the present application, the fiber composite material 100 is configured as a motor underbody guard.

[0092] The plurality of fiber layers 1 include a plurality of fiber fabric layers 12 , in which embedded parts 2 (such as metal embedded parts) are pre-embedded, and core layers 3 are arranged between the fiber fabric layers 12 .

[0093] like Figure 2 As shown, there are four fiber layers 1, and all of the four fiber layers 1 are fiber fabric layers 12. In the stacking direction, two fiber fabric layers 12 (such as glass fiber cloth) are provided on both sides of the core layer 3, and the core layer 3 is constructed as an aluminum honeycomb core with a three-dimensional lattice structure to improve the stiffness through the core layer 3.

[0094] Furthermore, the fiber layer 1 is stacked and cut into the shape of the battery pack bottom guard plate in the above order, and the cut fiber layer 1 pre-buries the embedded part 2 in the fiber layer 1 to obtain a fiber preform 10. After the fiber preform 10 is arranged in the mold, it is transferred to the molding equipment (such as: high-pressure resin transfer molding (HR-RTM) machine), the mold is closed and vacuumed, and the two reaction components of isocyanate and amino compound are injected at a pressure of 10-25MPa. The injection of the reaction components can be completed in about 25 seconds, and the mixture is fully mixed and the polymerization reaction is completed in the mold cavity under vacuum. The pressure is continued to be maintained, and the resin (such as: polyurea resin) is fully impregnated with the fiber layer 1 under pressure and cured to obtain the motor bottom guard plate.

[0095] In the second embodiment, the fiber preform 10 adopts a sandwich structure. Compared with a single-layer structure, the sandwich structure has better strength and can further improve the impact resistance of the fiber composite material 100.

[0096] The thickness of the motor lower guard plate in the second embodiment is 6 mm, and the thickness of the aluminum honeycomb core is 4 mm, which can withstand 400J of energy without penetration in a drop hammer impact test.

[0097] Reference Figure 3 In the third embodiment of the present application, the fiber composite material 100 is configured as a battery pack bottom guard plate of a vehicle. Compared with the first embodiment, the battery pack bottom guard plate in the third embodiment is provided with a reinforcing rib 4 on one side of the surface in the thickness direction, and the thickness of the reinforcing rib 4 is 1 mm. The battery pack bottom guard plate in the third embodiment can also resist 400J energy without penetration in a drop hammer impact test, and the deformation of the battery pack bottom guard plate caused by the impact can be partially restored.

[0098] In the fourth embodiment of the present application, the resin material is replaced by polyurethane elastomer resin instead of polyurea resin, and the other features are the same as those in the first embodiment. The thickness of the battery pack bottom guard plate in the fourth embodiment is 4 mm, and it can resist 400J energy without penetration in the drop hammer impact test, and the deformation of the battery pack bottom guard plate caused by the impact can be partially restored.

[0099] In Comparative Example 1, the composite material is a thermosetting epoxy resin (i.e., a thermosetting composite material used in the prior art), and during the molding process, the injection pressure is 2-5 MPa, the injection time is 180 s, the curing temperature is 110±5° C., and the curing time is 5 min.

[0100] When the structural member in Comparative Example 1 is also constructed as a battery pack bottom guard plate, when the thickness of the battery pack bottom guard plate is 4 mm, in a drop hammer impact test, the battery pack bottom guard plate can be penetrated and damaged by 150J of energy.

[0101] In Comparative Example 2, the structural member is an aluminum plate with the same size as that of the first embodiment (4 mm thick), and the aluminum plate is constructed as a battery pack bottom guard plate, and the aluminum plate can be penetrated by 180J of energy.

[0102] In comparative example 3, the structural part is prepared by spraying first and then molding. The structural part adopts the laying sequence of the fiber layer 1 in the first embodiment, and before each fiber layer 1 is laid, the upper and lower surfaces of the fiber layer 1 are sprayed with polyurea elastomer by high-pressure spraying equipment, the spraying pressure is 25M, and the gel is completed 25s after the spraying is completed. The laid reinforcing material with polyurea coating is further placed in the mold, the mold is closed and vacuumed, and a pressure of 1MPa is applied and maintained for 90min to obtain a composite material plate. The composite material plate in comparative example 3 is 4mm thick, and can be penetrated by 250J energy in the drop hammer impact test.

[0103] The performance comparison table of the first embodiment, the second embodiment, the third embodiment, the fourth embodiment and the comparative examples 1, 2 and 3 is as follows:

[0104]

[0105] Note: The drop hammer impact test in the examples and comparative examples of the present application uses a spherical punch with a diameter of 25 mm. The mass wear is tested using the ASTM G65-04 standard, with carbon steel as 1 as a reference. The smaller the value, the more wear-resistant the material.

[0106] In summary, in the present application, by designing the plying method, the core layer 3, the process and the material, a fiber composite material 100 with good impact resistance can be obtained. Among them, the reinforcing ribs or the core layer 3 with a honeycomb structure can improve the overall stiffness of the fiber composite material 100, and the impact resistance is consistent. Under the impact load, the resin matrix (elastic resin) undergoes a glass transition effect and viscous dissipation and hydrogen bond dissipation, and at the same time, the fibers in the fiber layer 1 and the resin matrix undergo interface slippage, which can further dissipate the impact energy.

[0107] Among them, the polyurea material alternates between soft segments and hard segments in the molecular structure, and has both elastomer and plastic properties. It is a microphase separation structure and has good wear resistance, which is significantly better than polyurethane, epoxy resin aluminum and other materials.

[0108] According to the protective structural component 200 of the embodiment of the present application, the protective structural component 200 includes an embedded component 2 and the above-mentioned fiber composite material 100, and the embedded component 2 is embedded in the fiber preform 10 along the stacking direction of the multiple fiber layers 1. The local strength of the fiber composite material 100 can be further improved by designing the embedded component 2, and a mounting structure can be formed at the embedded component 2 to form a mounting point on the fiber composite material 100, so as to facilitate the connection and coordination of the fiber composite material 100 with other components.

[0109] In some embodiments of the present application, the insert 2 is constructed as a metal part, which has high structural strength and can reduce the impact of high-pressure resin transfer molding on the insert 2. It can be understood that during the molding process of the fiber composite material 100, the insert 2 is pre-embedded in the fiber preform 10, that is, the insert 2 is arranged in the mold together with the fiber layer 1 and molded by high-pressure resin transfer molding.

[0110] like Figure 1-Figure 4 As shown, in some embodiments of the present application, the insert 2 is provided with a connection hole 21, so as to form a mounting structure on the fiber composite material 100 through the connection hole 21. The connection hole 21 can be configured to be through-set along the stacking direction, or can be configured to be non-through-set, so that the fiber composite material 100 can be assembled and fixed through the connection hole 21. For example, the connection hole 21 is used for a connection member (such as a bolt) to pass through, so as to fix the fiber composite material 100 at the installation position through the connection member and the installation position (such as a threaded hole). It should be noted that the mounting structure formed on the insert 2 is not limited to a hole structure, but can also be a connection groove, etc.

[0111] According to the vehicle of the embodiment of the present application, the vehicle includes the above-mentioned fiber composite material 100 or protective structure 200. The resin matrix in the fiber composite material 100 is fully impregnated with the reinforcing fiber, so that the fiber composite material 100 has good mechanical properties and the product quality is easy to control. At the same time, the fiber composite material 100 is formed by high-pressure resin transfer molding, and almost no small molecule volatiles are released during the molding process, the raw material utilization rate is high, the molding process is simple, the molding time and manufacturing cost are greatly reduced, and high-efficiency batch production can be achieved. In addition, under the same protective performance, the fiber composite material 100 in the present application has a lighter mass than the metal protective structure, thereby reducing the weight of the fiber composite material 100.

[0112] In some embodiments of the present application, the vehicle includes a battery pack, and the fiber composite material 100 is constructed as a battery pack protective plate. By constructing the above-mentioned fiber composite material 100 as a battery pack protective plate, the impact resistance of the battery pack can be improved.

[0113] In other embodiments of the present application, the vehicle includes a drive motor, the fiber composite material 100 is constructed as a lower guard plate, and the lower guard plate is arranged under the drive motor. By constructing the above-mentioned fiber composite material 100 as the lower guard plate of the motor, the motor can be protected by the lower guard plate.

[0114] According to the preparation method of the fiber composite material of the embodiment of the present application, the fiber composite material 100 includes a fiber preform 10 and a resin matrix, and the preparation method includes: placing the fiber preform 10 in a mold, and after the mold is closed and vacuumed, injecting resin material into the fiber preform 10, and high-pressure resin transfer molding the resin material and the fiber preform 10 to prepare the fiber composite material 100.

[0115] The fiber preform 10 may be constructed as the preform structure formed by stacking a plurality of fiber layers 1 as mentioned in the above embodiments.

[0116] When preparing the fiber-fiber composite material 100, the fiber preform 10 is first arranged in a mold, and the mold is further closed and vacuumed. After the vacuuming action is completed, the resin material is injected at a preset pressure for a preset time, and the pressure is maintained so that the resin material fully impregnates the fibers in the fiber preform under pressure, and finally solidifies to obtain the fiber composite material 100.

[0117] The resin material may be two reactants, such as two reaction components, namely, isocyanate and amino compound, which are fully mixed and polymerized in a high-pressure resin transfer molding device to generate polyurea resin.

[0118] It should be noted that after the fiber preform is arranged in the mold, the mold and the fiber preform arranged in the mold are transferred to a high-pressure resin transfer molding device, and steps such as mold closing, vacuuming, and resin injection are performed.

[0119] In some embodiments of the present application, the injection pressure of the resin material is: 0-25MPa, preferably, the injection pressure of the resin material is 10-25Mpa, so that the resin material (such as: the above-mentioned isocyanate and amino compound) can be fully mixed, and the filling speed of the resin material is increased, the wetting effect of the resin material on the fiber is improved, and bubbles are reduced, further reducing the porosity.

[0120] In some embodiments of the present application, the resin material injection time is 5s-180s, preferably 10s-30s. The resin material injection time refers to: the duration of injecting the resin material.

[0121] After the resin material is injected while maintaining the injection pressure, the resin material can be allowed to fully infiltrate the fiber preform under pressure by continuing to maintain the pressure, and finally solidify and demould to obtain the fiber composite material 100.

[0122] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0123] In the description of this application, "first feature" or "second feature" may include one or more of the features.

[0124] In the description of the present application, “plurality” means two or more.

[0125] In the description of the present application, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0126] In the description of the present application, “above”, “over” and “above” a first feature to a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0127] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0128] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A fiber composite material, characterized in that: include: A plurality of fiber layers (1); A resin matrix, wherein the resin matrix impregnates the plurality of fiber layers (1) through high-pressure resin transfer molding with the plurality of fiber layers (1); It also comprises a core layer (3), wherein in the stacking direction of the plurality of fiber layers (1), the core layer (3) is arranged between two of the fiber layers (1). The core layer (3) is constructed as a lattice structure, and the lattice structure is constructed as one of a honeycomb structure, a polygonal structure, a cross-shaped structure, and a polyhedron structure. The resin matrix is ​​made of an elastomeric resin material, and the elastomeric resin material includes polyurea, The multiple fiber layers (1) are formed by stacking a unidirectional fiber layer (11) and a fiber fabric layer (12), wherein the unidirectional fiber layer (11) comprises a plurality of fibers (101) extending in the same direction and arranged in sequence, and the fiber fabric layer (12) comprises a plurality of fibers (101) arranged in an interlaced manner; The fiber composite material (100) is provided with reinforcing ribs (4), wherein the reinforcing ribs (4) are arranged on the fiber layer (1) located at the outermost side when stacked upward, and the reinforcing ribs (4) are arranged perpendicular to each other.

2. The fiber composite material according to claim 1, characterized in that The resin matrix impregnates the multiple fiber layers (1) through high-pressure resin transfer molding with a fiber preform composed of the multiple fiber layers (1).

3. The fiber composite material according to claim 1, characterized in that The plurality of fiber layers (1) include a plurality of unidirectional fiber layers (11); wherein: The extension directions of the fibers (101) in two adjacent unidirectional fiber layers (11) are parallel to each other; And / or, in the projection in the stacking direction, the extension directions of the fibers (101) in two adjacent unidirectional fiber layers (11) have an angle, and the angle α satisfies the relationship: 45°≤α≤90°.

4. The fiber composite material according to claim 1, characterized in that The material of the lattice structure includes at least one of aluminum alloy, fiber-reinforced composite material, aramid, polypropylene and ultra-high molecular weight polyethylene.

5. The fiber composite material according to claim 1, characterized in that The fiber material in the fiber layer (1) comprises at least one of carbon fiber, glass fiber, aramid fiber, basalt fiber, ultra-high molecular weight polyethylene fiber, and boron nitride fiber.

6. A protective structural member, characterized in that: It comprises an embedding part (2) and the fiber composite material according to any one of claims 1 to 5, wherein the embedding part (2) is embedded in the multiple fiber layers (1) along the stacking direction of the multiple fiber layers (1).

7. The protective structural member according to claim 6, characterized in that: The insert (2) is constructed as a metal part.

8. The protective structural member according to claim 6, characterized in that: The embedded part (2) is provided with a connecting hole (21).

9. A vehicle, characterized in that: The invention comprises the fiber composite material according to any one of claims 1 to 5, or the protective structure according to any one of claims 6 to 8.

10. A method for preparing a fiber composite material, characterized in that: Used for preparing the fiber composite material according to any one of claims 1 to 5, the fiber composite material comprising a resin matrix and a plurality of fiber layers (1), the preparation method comprising: A fiber preform (10) composed of the plurality of fiber layers (1) is placed in a mold, and after the mold is closed and vacuumed, a resin material is injected into the fiber preform (10), and the resin material and the fiber preform (10) are molded by high-pressure resin transfer molding.

11. The method for preparing a fiber composite material according to claim 10, characterized in that: Resin material injection pressure: 10-25MPa; And / or, the resin material injection time is 5s-180s.

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