Carbon fiber composite rib-containing cross beam for commercial vehicle and co-curing preparation process of carbon fiber composite rib-containing cross beam

Abstract

The invention relates to the field of composite manufacturing, and discloses a carbon fiber composite rib-containing cross beam for a commercial vehicle and a co-curing preparation process of the carbon fiber composite rib-containing cross beam for the commercial vehicle, and the cross beam comprises a rear cross beam main body which is prepared from carbon fiber woven cloth and an epoxy resin matrix through a co-curing process; the rib plate is located at the right-angle turning position of the cross beam body and integrally formed with the cross beam body through a co-curing process; the metal lining is embedded in the cross beam main body and used for assembly of bolt connection, and the lining and the main body are formed into a whole through a co-curing process. The preparation process comprises the steps of mold preparation, rib plate positioning, main body laying, lining installation, vacuumizing, curing and aftertreatment. Through the characteristics of light weight and high strength of the carbon fiber composite material and the optimal design of the rib plates and the metal linings, light weight, high strength and fatigue performance improvement of the commercial vehicle rear cross beam are achieved, and the commercial vehicle rear cross beam has good environmental adaptability and wide application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of composite material manufacturing, and in particular to a carbon fiber composite material ribbed crossbeam for commercial vehicles and a co-curing preparation process thereof. Background Art

[0002] With the development of the automobile industry, lightweighting has become one of the important directions in the design and manufacture of commercial vehicles. Carbon fiber reinforced resin-based composite materials are gradually being used in automotive structural parts due to their excellent properties such as high specific strength, high specific modulus, and corrosion resistance. Compared with traditional metal materials, carbon fiber composite materials can significantly reduce the weight of components while ensuring strength and stiffness, so they have broad application prospects in the field of commercial vehicles.

[0003] However, the rear crossbeams of traditional commercial vehicles are mostly made of metal materials, such as steel and aluminum alloy. Although these materials have certain strength and rigidity, they are heavy, which limits the lightweight design of the entire vehicle. In addition, in scenarios where complex load conditions need to be met, the stress concentration problem of traditional metal crossbeams is more prominent, especially at right-angle turns, where fatigue failure is prone to occur, affecting the service life. At the same time, due to the limitations of metal materials on fatigue performance and environmental adaptability, they may degrade in performance due to fatigue cracks or corrosion after long-term use.

[0004] Although some existing commercial vehicle crossbeam technologies based on composite materials try to take advantage of the lightweight advantages of carbon fiber composite materials, they still have many shortcomings in practical applications. For example, the stiffness and strength of composite crossbeams in local areas are difficult to meet the design requirements, especially at corners or assembly locations of connecting bolts. Traditional mechanical connection methods are prone to wear or failure of the connection parts, while increasing manufacturing costs. In addition, existing processes often require multiple separate processing steps, which are inefficient and difficult to ensure consistent product quality.

[0005] Therefore, how to utilize the excellent performance of carbon fiber composite materials to design a commercial vehicle rear beam structure that is lightweight, high-strength and highly reliable, and solve the shortcomings of traditional structures and processes through optimized manufacturing processes is an urgent problem to be solved in the current technical field. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a carbon fiber composite material ribbed cross beam for commercial vehicles and a co-curing preparation process thereof, which solves the problems of heavy weight, stress concentration, insufficient fatigue performance and low manufacturing efficiency of the existing rear cross beams of commercial vehicles.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A carbon fiber composite material ribbed crossbeam for commercial vehicles, comprising:

[0008] The rear cross member body is made of prepreg composited with carbon fiber woven cloth and epoxy resin matrix through a co-curing process;

[0009] The rib plate is located at the right-angle turn of the beam body and is integrally formed with the beam body through a co-curing process;

[0010] The metal bushing is embedded in the main body of the crossbeam and is used for assembling the connecting bolts. The metal bushing and the main body of the crossbeam are solidified synchronously to form a whole.

[0011] Preferably, the carbon fiber prepreg comprises:

[0012] 0° / 90° biaxial prepreg fabric to provide bending strength;

[0013] 45° / -45° biaxial prepreg fabric to provide shear resistance.

[0014] Preferably, the prepregs are laid alternately in different fiber directions to form a multi-layer composite material structure.

[0015] Preferably, the rib plate is a C-shaped structure, and the material of the rib plate is the same as that of the rear cross beam body.

[0016] Preferably, the rib material and the rear cross beam body are both composed of T400-12K carbon fiber woven cloth and epoxy resin matrix.

[0017] Preferably, the metal bushing is made of aluminum alloy and is fixed in the mold by a positioning device during laying so that it is solidified synchronously with the rear cross beam body.

[0018] Preferably, the fiber mass content of the carbon fiber prepreg of the rear cross beam body is 58% to 65%.

[0019] The present invention also provides a co-curing preparation process of a carbon fiber composite material ribbed cross beam for commercial vehicles, comprising the following steps:

[0020] Mould preparation: design and manufacture the integral split mould, including upper and lower moulds, left and right moulds and demolding module; before paving, clean the mould surface and apply release agent and release wax;

[0021] Bushing installation: Place the aluminum alloy metal bushing at the predetermined position in the mold and fix it by bonding;

[0022] Rib positioning: Cut the carbon fiber prepreg according to the shape of the rib, lay it to the limit of the rib groove on the upper surface of the mold and compact it;

[0023] Main body laying: alternately lay 0° / 90° and 45° / -45° carbon fiber prepregs to the designed thickness, and lay unidirectional prepregs at right-angle turns for reinforcement;

[0024] Vacuuming: Perform vacuum treatment to remove bubbles in the ply;

[0025] Curing: Place the assembled mold into a preheated 60°C molding press and cure according to the preset temperature, pressure and time parameters;

[0026] Post-processing: After curing is completed and cooled to room temperature, the beam parts are trimmed and polished after demoulding to ensure surface quality and dimensional accuracy.

[0027] Preferably, the temperature of the curing process is 130° C. to 150° C., the pressure is 30 to 100 kg, and the curing time is 1 to 2 hours.

[0028] Preferably, the curing process adopts a multi-stage heating process, including:

[0029] In the first stage, the temperature was raised from room temperature to the pre-curing temperature at a heating rate of 2°C / min;

[0030] The second stage is to maintain the pre-curing temperature for a certain period of time;

[0031] In the third stage, the temperature is raised to the final curing temperature at a heating rate of 1°C / min.

[0032] The present invention provides a carbon fiber composite material ribbed cross beam for commercial vehicles and a co-curing preparation process thereof. It has the following beneficial effects:

[0033] 1. The present invention adopts carbon fiber composite materials as the main material of the rear cross beam, combined with the integrated design of ribs and metal bushings, which significantly reduces the weight of the rear cross beam. While meeting the strength and stiffness requirements, it reduces the weight of the vehicle, thereby improving fuel economy and reducing emissions, which is in line with the development trend of lightweight commercial vehicles.

[0034] 2. The present invention significantly enhances the overall structural strength and rigidity of the rear cross beam by alternately laying carbon fiber prepregs in the directions of 0° / 90° and 45° / -45°, and using unidirectional prepregs for reinforcement at right-angle turns. In particular, the C-shaped ribs are arranged to effectively disperse stress in stress concentration areas, thereby increasing local fatigue life.

[0035] 3. The present invention embeds an aluminum alloy metal bushing in the crossbeam body and adopts a roughened surface design and a co-curing molding process, so that the metal bushing forms a firm interface bond with the composite material body. This design avoids wear caused by direct contact of the bolts with the carbon fiber, and enhances the reliability and long-term durability of the bolt connection.

[0036] 4. The present invention significantly improves the stress concentration problem at the right-angle turning point of the beam by providing unidirectional prepreg reinforcement at the ribs and corners. The co-curing molding design of the ribs and the main body enhances the local stiffness and strength of the area, effectively reduces the risk of fatigue cracks, and thus extends the service life of the beam.

[0037] 5. The co-curing process realizes the integrated molding of the rib plate, metal bushing and the beam body, without the need for traditional mechanical connection or subsequent drilling process, which greatly simplifies the production process. This process not only reduces manufacturing costs, but also improves production efficiency and is suitable for mass production.

[0038] 6. The design and manufacturing process of the present invention is not only applicable to the rear cross beam of commercial vehicles, but can also be extended to other structural parts fields with high strength and lightweight requirements, such as rail transit components, aerospace structural parts, etc., showing good technical versatility and industrialization potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0040] Figure 2 It is a schematic diagram of the process flow of the present invention.

[0041] Among them, 1. The main body of the rear cross beam; 2. The rib plate; 3. The metal bushing. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Please see attached Figure 1 The present invention provides a carbon fiber composite material ribbed cross beam for commercial vehicles, which aims to achieve a lightweight design of a rear cross beam of a commercial vehicle, while ensuring that it has high strength, high stiffness and excellent fatigue performance during use. The entire cross beam is made by a co-curing process, achieving efficient integration of the rib plate 2, the metal bushing 3 and the main body, thereby improving production efficiency, reducing manufacturing costs, and significantly improving mechanical properties.

[0044] like Figure 1 As shown, the carbon fiber composite material ribbed cross beam for commercial vehicles mainly includes a rear cross beam body 1, a rib plate 2 and a metal bushing 3. Each component is described in detail below.

[0045] Rear cross member body 1

[0046] In this embodiment, the rear cross beam body 1 is made of prepreg composited with carbon fiber woven cloth and epoxy resin matrix through a co-curing process, and has the structural characteristics of lightweight and high strength. Its design meets the mechanical performance requirements of the rear cross beam of commercial vehicles under complex working conditions.

[0047] As an option, the carbon fiber prepreg of the rear cross beam body 1 adopts T400-12K carbon fiber biaxial cloth, and the fiber directions include 0° / 90° and 45° / -45° to meet the strength requirements of the cross beam under bending load and shear load. Among them, the prepreg with a fiber direction of 0° / 90° mainly provides the bending resistance of the cross beam, while the prepreg with a fiber direction of 45° / -45° is used to enhance its shear resistance.

[0048] In some embodiments, the carbon fiber prepreg of the rear cross beam body 1 is laid alternately in the fiber direction to form a multi-layer composite structure to further optimize the overall strength and stiffness. Specifically, the alternating direction during laying can reduce interlayer stress concentration and avoid degradation of mechanical properties in local areas.

[0049] The matrix material of the rear cross beam body 1 is epoxy resin, which has excellent adhesion, fatigue resistance and durability, and can ensure reliable bonding between carbon fiber layers. It is understood that epoxy resin can also be modified according to specific performance requirements, such as by adding toughening agents (such as liquid rubber or block copolymers) to improve the impact resistance of the composite material.

[0050] As a possible implementation method, 1% to 5% by mass of nano-silicate or carbon nanotubes can be added to the epoxy resin to enhance the interface strength and thermal conductivity. The use of these additives can further optimize the overall performance of the rear cross beam body 1, especially the stability under long-term fatigue load or high temperature environment.

[0051] It should be noted that the ply thickness of the rear cross beam body 1 is designed according to the specific load requirements of the vehicle. In some embodiments, the fiber density of the ply is 190 g / m 2 Up to 250g / m 2 To achieve a balance between weight and strength. Specifically, the thickness and direction of the ply can be optimized through mechanical simulation calculations to meet the performance requirements of different models.

[0052] As a possible structural design, the right-angle turn of the rear cross beam body 1 is a key stress concentration area. To this end, in this embodiment, unidirectional prepreg is used to reinforce this area, and the unidirectional prepreg is bonded with other layers to form a complete composite material structure. This reinforcement measure can significantly reduce the risk of stress concentration at the corner and extend the fatigue life of the cross beam.

[0053] It should be pointed out that the fiber mass content of the carbon fiber prepreg of the rear cross beam body 1 is 58% to 65%, to ensure that the finished structure can maintain a certain toughness, while the fiber and the matrix material have sufficient interface bonding strength, and the overall mechanical properties will not be reduced due to excessive matrix material.

[0054] It is understandable that the rear cross beam body 1 needs to be manufactured through precise mold design and ply sequence control to ensure that the fiber direction is consistent with the mechanical requirements. This design can maximize the high specific strength and specific modulus characteristics of carbon fiber, so that the cross beam body can achieve the goal of lightweight while ensuring performance.

[0055] In this embodiment, the rear cross beam body 1 can withstand large bending loads and shear loads during use, and its multi-directional ply structure can effectively resist stress in all directions, thereby ensuring the reliability of the cross beam under complex working conditions.

[0056] Rib 2

[0057] In this embodiment, the rib 2 is arranged at the right-angle turn of the rear cross beam body 1 and is integrally formed with the cross beam body through a co-curing process. Its main function is to enhance the rigidity and strength of this area to cope with the stress concentration problem at the right-angle turn.

[0058] As an option, the rib plate 2 is made of the same material as the rear cross member body 1, namely T400-12K carbon fiber prepreg cloth. This material combination has excellent mechanical properties, can provide high strength and high stiffness under the premise of light weight, thereby significantly improving the structural performance at corners.

[0059] Specifically, according to the loading conditions of the actual vehicle under complex conditions and the installation constraint position of the crossbeam, the load can be regarded as a small torsion with different amplitudes and frequencies that changes randomly. Adding ribs will greatly increase the overall torsional stiffness of the crossbeam, thereby reducing the overall torsional deformation of the crossbeam and thus reducing the overall load. In addition, the geometric shape of the rib 2 is designed to be C-shaped, and its arc structure can effectively disperse the stress concentration at the right-angle turn and improve the overall strength by being closely combined with the crossbeam body. In some embodiments, the thickness and size of the rib 2 are optimized according to the specific load requirements of the vehicle to achieve a balance between weight and performance.

[0060] In a possible implementation, the ply design of the rib plate 2 follows the principle of alternating fiber directions to further improve the mechanical properties. For example, the rib plate 2 ply uses carbon fiber prepregs in 0° / 90° and 45° / -45° directions to be laid alternately, and each layer is bonded to each other by the epoxy resin of the carbon fiber prepregs, thereby forming a stable multi-layer structure.

[0061] It should be noted that the laying direction of the rib plate 2 is in a certain matching relationship with the fiber direction of the rear cross beam body 1 to ensure uniform interlayer stress transmission at the joint between the two and avoid structural weakening or delamination caused by direction mismatch. It is understandable that this laying design can provide higher strength and stability under bending load and torsional load.

[0062] As an option, the edge of the rib plate 2 is designed with a certain transition arc, so as to form a smooth transition at the connection with the rear cross beam body 1. This design can further reduce the stress concentration at the connection and improve the interface bonding performance between the rib plate 2 and the body.

[0063] In some embodiments, in order to further improve the impact resistance of the rib plate 2, a certain proportion of toughening agent, such as 2% to 8% by mass of liquid rubber or block copolymer, may be added to the epoxy resin matrix of the rib plate 2. These additives can effectively improve the toughness of the rib plate 2 under dynamic loads and avoid structural failure caused by impact loads.

[0064] It should be noted that the fiber direction accuracy of the rib 2 directly affects its mechanical properties. In this embodiment, the fiber direction deviation is precisely controlled to be no more than ±2° to ensure that the mechanical properties of the rib 2 in actual use are fully exerted along the design direction. This precision control is achieved through special tools and equipment used in the material cutting and laying process.

[0065] It is understandable that after the rib plate 2 and the beam body are integrally formed through the co-curing process, their overall performance is significantly improved compared to the traditional mechanically connected split design. The integrated structure not only avoids the stress concentration problem caused by mechanical connection, but also simplifies the production process and improves production efficiency.

[0066] In some possible embodiments, the surface of the rib plate 2 may be designed with a special texture structure for enhancing the bonding strength, and these textures can increase the interface area between the rib plate 2 and the cross beam body, thereby further improving the interface bonding strength. This design is particularly suitable for commercial vehicle cross beams that need to bear a large load.

[0067] In practical applications, the ribs 2 in this embodiment are mainly used to improve the fatigue performance of the right-angle turning portion of the rear cross beam and effectively extend the service life of the cross beam.

[0068] Metal Bushing 3

[0069] In this embodiment, the metal bushing 3 is embedded in the rear cross beam body 1 for bolt connection and assembly to solve the wear, stress concentration and fatigue failure problems that may be caused by direct contact between the carbon fiber composite material and the metal bolt. The metal bushing 3 forms an integral structure through a co-curing process with the cross beam body to ensure its accurate position and high-strength connection performance.

[0070] As an option, the metal bushing 3 is made of aluminum alloy. Aluminum alloy has high strength and corrosion resistance, low density and certain wear resistance, and can meet the requirements of structural strength and long-term use without significantly increasing the overall weight. It can be understood that the selection of aluminum alloy material takes into account both lightweight design and durability requirements, and is a preferred material for commercial vehicle crossbeams.

[0071] Specifically, the outer surface of the metal bushing 3 is roughened, such as by sandblasting or etching, to enhance the interfacial bonding between it and the carbon fiber composite material. For example, such roughening can enable the epoxy resin matrix to better fill the microscopic concave-convex structure on the surface of the metal bushing 3 during the co-curing process, thereby significantly improving the embedding stability of the bushing.

[0072] In some embodiments, the metal bushing 3 is cylindrical in shape, and its outer diameter matches the reserved hole diameter in the beam body to achieve a precise fit. In order to further improve the bonding performance of the bushing, its end is designed as a chamfered structure, which can reduce stress concentration during the curing process and improve the fluidity and permeability of the epoxy resin at the interface.

[0073] As a possible implementation, the inner diameter design of the metal bushing 3 is determined according to the specifications of the bolts to be adapted, and the inner surface is anodized to improve the wear resistance and corrosion resistance. It is understandable that the finish and dimensional accuracy of the inner diameter surface play an important role in the firmness and long-term reliability of the bolt connection.

[0074] It should be noted that the axial length of the metal bushing 3 is adjusted according to the thickness of the beam body. In some embodiments, the length of the metal bushing 3 is slightly greater than the thickness of the beam body, ensuring that both ends of the bushing are flush with the surface of the body or slightly protrude. This design can effectively disperse the axial load applied by the bolt and prevent the carbon fiber layer from compressing and deforming when subjected to force.

[0075] In another possible implementation, an annular groove is designed on the outer periphery of the metal bushing 3, and the groove is filled with epoxy resin matrix material. This design can further enhance the anti-pullout performance of the bushing during the co-curing process, thereby improving its reliability under long-term vibration loads.

[0076] It is understandable that the embedded position of the metal bushing 3 in the rear cross beam body 1 needs to meet specific mechanical distribution requirements to ensure connection strength and uniform load distribution. For example, the metal bushing 3 is usually arranged at key connection points of the cross beam, such as the connection parts with the vehicle body or other structural parts, to ensure that these areas have sufficient tensile, shear and extrusion resistance.

[0077] The metal bushing 3 in this embodiment is formed integrally with the rear cross beam body 1 through a co-curing process, resulting in a strong interface bond between the bushing and the carbon fiber composite material, thereby avoiding the slippage or loosening problems that may occur in traditional mechanical connections. This integrated design significantly improves the structural strength and service life of the entire cross beam.

[0078] In some embodiments, the material and structural design of the metal bushing 3 can also be adjusted according to different vehicle models or load conditions. For example, for a vehicle model that needs to withstand a higher load, a higher strength titanium alloy can be selected as the bushing material, or the outer diameter of the bushing can be increased, the number of sleeves can be reasonably added, or the sleeve positions can be distributed to improve the shear resistance of the embedded area.

[0079] It should be noted that the arrangement and design of the metal bushing 3 can be adapted to the use requirements in different environments. For example, commercial vehicles operating in a salt spray corrosion environment can further improve durability by adding an anti-corrosion coating on the bushing surface; vehicles operating in a high vibration environment can reduce stress concentration by optimizing the size and geometric structure of the bushing.

[0080] The metal bushing 3 in this embodiment not only meets the mechanical performance requirements of the bolt connection, but also achieves efficient production and optimization of structural performance through a synchronous molding process with the carbon fiber composite material, providing reliable technical support for the lightweight and high-performance design of commercial vehicle crossbeams.

[0081] In general, the present invention achieves lightweight, high strength and excellent fatigue performance of the rear crossbeam by adopting a composite body composed of carbon fiber woven cloth and epoxy resin matrix, combined with the C-shaped rib plate 2 design and the embedded metal bushing 3 structure. The rib plate 2 is located at the right-angle turn of the crossbeam. Through one-piece molding, the local strength is improved, the overall rigidity is increased, and the problem of large torsional deformation is solved; the metal bushing 3 is synchronously cured with the main body to ensure the reliability and durability of the bolt connection. The overall process meets the use requirements under complex load conditions through precise material selection and design optimization, providing an efficient solution for lightweighting and improving structural performance of commercial vehicles.

[0082] Please refer to the attached Figure 2 Correspondingly, the present invention also provides a co-curing preparation process of a carbon fiber composite material ribbed crossbeam for commercial vehicles, comprising the following steps:

[0083] S1. Mold preparation:

[0084] In this embodiment, the mold is designed as an integral split structure, including four pieces of upper and lower molds and left and right molds, and a small stripping module is designed to facilitate laying and molding operations. The inner cavity of the mold is precisely customized according to the shape of the rear crossbeam, and a dedicated positioning structure is set in the rib plate area to ensure the laying accuracy of the rib plate.

[0085] As an option, in order to avoid surface defects on the finished beam, the inner surface of the mold is coated with a high temperature resistant release agent and polished to a mirror finish to improve the surface finish and demoulding performance of the mold. It should be noted that the mold is also equipped with a multi-point vacuum interface to effectively remove bubbles during the subsequent vacuum operation.

[0086] S2. Rib positioning:

[0087] In this embodiment, the carbon fiber prepreg is designed and cut according to the shape of the rib plate, and is precisely laid to the designated position of the rib plate in the mold. When laying the rib plate, the carbon fiber prepreg in the 0° / 90° direction is preferably used as the bottom material to provide basic stiffness.

[0088] Specifically, after the rib area is laid, a rolling tool is used to compact each layer of prepreg to eliminate potential bubbles and ensure that the material fits tightly against the inner wall of the mold. This process lays the foundation for the high-precision forming of the rib and its integration with the main beam.

[0089] S3. Main body laying:

[0090] After the ribs are laid, the carbon fiber prepreg is laid on the beam body. In this embodiment, the main body is laid by alternately laying the carbon fiber prepreg in the directions of 0° / 90° and 45° / -45° until the designed thickness is reached.

[0091] In a possible implementation, additional unidirectional prepreg is cut in the right-angle turning area of ​​the beam body for reinforcement. It should be noted that the laying of unidirectional prepreg can not only significantly improve the local strength of the turning area, but also effectively improve the stress concentration problem and extend the service life of the beam.

[0092] During the laying process, each layer of carbon fiber prepreg is compacted and rolled from one end to the other along the fiber direction using a special rolling tool to ensure that the layers are tightly bonded and no bubbles remain.

[0093] When laying, round holes are left on the prepreg, and the bushing passes through the round holes of each layer of prepreg. Multiple layers of prepreg completely wrap the bushing.

[0094] S4. Bushing installation:

[0095] Before laying, the aluminum alloy metal bushing with roughened surface is placed at a predetermined position in the mold. For example, the bushing is fixed by a professional glue with weaker bonding force to ensure that it will not be displaced during the subsequent laying process. The bushing is installed before the main body is laid. When laying each layer of prepreg, a circular hole is left on the prepreg, and the bushing passes through the circular hole of each layer of prepreg, and the bushing is completely wrapped during the laying of multiple layers of prepreg.

[0096] It can be understood that the outer peripheral surface of the metal bushing is designed with an annular groove, and the groove is filled with epoxy resin matrix material to further improve its bonding performance with the carbon fiber layer.

[0097] S5. Vacuuming:

[0098] After the main body is paved on the lower mold of the mold, before the mold is closed, a closed cavity is made in the lower mold using adhesive strips, breathable felt and vacuum bags to wrap the unformed part. Subsequently, the mold is evacuated by a vacuum pump, air pipe and metal nozzle. In this embodiment, the vacuum degree is controlled at -0.1MPa, and the operation time is 10 to 15 minutes to ensure that the air and bubbles inside the mold are completely removed. After vacuuming, observe the state of the preform to ensure that there are no bubbles or unevenness before closing the mold and closing the mold.

[0099] It can be understood that the vacuum operation is of great significance to ensure the interface bonding quality between carbon fiber layers and between carbon fiber and metal bushing, which can effectively prevent delamination or void defects in the finished product.

[0100] S6. Curing:

[0101] The curing process in this embodiment adopts a multi-stage temperature increase process to ensure that the epoxy resin matrix is ​​fully cross-linked during the curing process, while avoiding the problem of internal stress in the material caused by too rapid temperature changes. The specific steps are as follows:

[0102] The first stage: the temperature is raised from room temperature to the pre-curing temperature (60°C) at a rate of 2°C / min and maintained for 30 minutes. This stage is to reach the glue coating temperature, at which time the viscosity of the glue decreases and the fluidity increases, allowing the glue to fully flow in the mold, eliminating internal pores and reducing the surface glue deficiency phenomenon.

[0103] The second stage: the temperature is increased from the pre-curing temperature to the final curing temperature (130-150°C) at a heating rate of 1°C / min and maintained for 1 to 2 hours to ensure that the resin is completely cross-linked.

[0104] Stage 3: After the final curing is completed, the heating is stopped and the mold is slowly cooled to room temperature along with the equipment to avoid thermal stress caused by rapid cooling.

[0105] It should be noted that during the curing process, a pressure of 30 kg was maintained in the first stage and a pressure of 100 kg was maintained in the second stage to further improve the interlayer bonding strength and ensure the dimensional accuracy of the final beam.

[0106] S7, post-processing:

[0107] After curing is complete and cooling to room temperature, the mold is removed and the beam components are post-processed.

[0108] The specific steps are as follows:

[0109] Trimming: Use high-precision cutting tools to trim the edges of the beams to remove burrs and excess material.

[0110] Sanding: Sand the surface of the beam using 200-600 grit sandpaper to improve the surface finish and eliminate potential blemishes.

[0111] Quality inspection: Ultrasonic testing or CT scanning is used to detect defects such as bubbles and delamination inside the beam. Mechanical tests such as bending strength and fatigue performance are also carried out to ensure that the quality of the beam meets the design requirements.

[0112] In this embodiment, through the above co-curing preparation process, the rib plate, metal bushing and rear cross beam body are integrally formed, which significantly improves the overall structural strength and service life of the cross beam. The optimized laying sequence and curing parameters can ensure that the mechanical properties of the composite material are fully exerted, while greatly improving production efficiency, providing a reliable high-performance lightweight solution for the commercial vehicle field.

[0113] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A carbon fiber composite material ribbed cross beam for commercial vehicles, characterized in that: include: The rear cross member body is made of prepreg fabric composited with carbon fiber woven fabric and epoxy resin matrix through a co-curing process; The rib plate is located at the right-angle turn of the beam body and is integrally formed with the beam body through a co-curing process; The metal bushing is embedded in the main body of the crossbeam and is used for assembling the connecting bolts. The metal bushing and the main body of the crossbeam are solidified synchronously to form a whole.

2. The carbon fiber composite material ribbed cross beam for commercial vehicles according to claim 1, characterized in that: The carbon fiber prepreg comprises: 0° / 90° biaxial prepreg fabric to provide bending strength; 45° / -45° biaxial prepreg fabric to provide shear resistance.

3. The carbon fiber composite material ribbed cross beam for commercial vehicles according to claim 2, characterized in that: The prepregs are laid alternately according to different fiber directions to form a multi-layer composite material structure.

4. The carbon fiber composite material ribbed cross beam for commercial vehicles according to claim 1, characterized in that: The rib plate is a C-shaped structure, and the material of the rib plate is the same as that of the rear cross beam body.

5. The carbon fiber composite material ribbed cross beam for commercial vehicles according to claim 3, characterized in that: The rib material and the rear cross beam body are both made of T400-12K carbon fiber prepreg cloth.

6. The carbon fiber composite material ribbed cross beam for commercial vehicles according to claim 1, characterized in that: The metal bushing is made of aluminum alloy and is fixed in the mold by a positioning device during laying so that it is solidified synchronously with the rear cross beam body.

7. The carbon fiber composite material ribbed cross beam for commercial vehicles according to claim 1, characterized in that: The fiber mass content of the carbon fiber woven cloth prepreg of the rear cross beam body is 58% to 65%.

8. A co-curing preparation process of a carbon fiber composite material ribbed cross beam for commercial vehicles, used to prepare the carbon fiber composite material ribbed cross beam for commercial vehicles as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Mould preparation: design and manufacture the integral split mould, including upper and lower moulds, left and right moulds and demolding module; before paving, clean the mould surface and apply release agent and release wax; Bushing installation: Place the aluminum alloy metal bushing at the predetermined position in the mold and fix it by bonding; Rib positioning: Cut the carbon fiber prepreg according to the shape of the rib, lay it to the limit of the rib groove on the upper surface of the mold and compact it; Main body laying: alternately lay 0° / 90° and 45° / -45° carbon fiber prepregs to the designed thickness, and lay unidirectional prepregs at right-angle turns for reinforcement; Vacuuming: Perform vacuum treatment to remove bubbles in the ply; Curing: Place the assembled mold into a preheated 60°C molding press and cure according to the preset temperature, pressure and time parameters; Post-processing: After curing is completed and cooled to room temperature, the beam parts are trimmed and polished after demoulding to ensure surface quality and dimensional accuracy.

9. The co-curing preparation process of the carbon fiber composite material ribbed cross beam for commercial vehicles according to claim 8, characterized in that: The temperature of the curing process is 130° C. to 150° C., the pressure is 30 to 100 kg, and the curing time is 1 to 2 hours.

10. The co-curing preparation process of the carbon fiber composite material ribbed cross beam for commercial vehicles according to claim 8, characterized in that: The curing process adopts a multi-stage heating process, including: In the first stage, the temperature was raised from room temperature to the pre-curing temperature at a heating rate of 2°C / min; The second stage is to maintain the pre-curing temperature for a certain period of time; In the third stage, the temperature is raised to the final curing temperature at a heating rate of 1°C / min.

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