Composite material antenna beam, preparation method thereof, and rail vehicle

Abstract

The present invention relates to a composite antenna beam, a preparation method thereof, and a rail vehicle, and belongs to the field of composite material forming technology. The preparation method comprises: preparing a crossbeam; laying a fiber composite material on the surface of a mounting seat mold core to obtain an inner layer of the mounting seat; gluing the crossbeam to the inner layer of the mounting seat, and then laying a fiber composite material on the outer side of the whole composed of the crossbeam and the inner layer of the mounting seat to obtain a middle layer of the mounting seat; subjecting the mounting seat mold core, the inner layer of the mounting seat, the crossbeam, and the middle layer of the mounting seat to autoclave forming; applying glue on the outer side of the solidified middle layer of the mounting seat and laying a fiber composite material to obtain an outer layer of the mounting seat, subjecting the entire device to autoclave forming to obtain a composite antenna beam. The middle part of the crossbeam is wrapped between the inner layer of the mounting seat and the middle layer of the mounting seat of the lay-up structure. Since the mounting seat has not yet been solidified during the laying process, the degree of close fit between the surfaces of the two can be effectively improved, thereby improving the connection strength between the crossbeam and the support seat.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material forming, and in particular relates to a composite material antenna beam, a preparation method thereof, and a rail vehicle. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] The bogie antenna mounting beam (antenna beam) is a critical load-bearing accessory for the vehicle and serves as the mounting platform for the ATP monitoring antenna. It consists of a mounting base and a horizontal crossbeam. The mounting base secures the antenna beam to the vehicle roof, while the antenna is mounted via supports and other structures at both ends of the crossbeam. The mounting base is located in the middle of the crossbeam, where the two are fixedly connected.

[0004] Due to the requirement of lightweight vehicle body, there are technical solutions for preparing antenna beams with composite materials. There are two main ways to connect the mounting base and the horizontal beam. The first is to form the beam and the mounting base separately, and then connect them together by gluing and then riveting. The riveted structure strengthens the connection and compensates for the problem of insufficient bonding strength. However, in this solution, the riveted structure will destroy the continuity of the fibers inside the beam and produce microcracks, which can easily cause connection failure. The second is to form the beam part by laying the prepreg used to prepare the mounting base on the mold, and then co-curing the two after connection. Since the interior of the mounting base is a hollow structure, foam needs to be used for filling during molding. The foam transmits pressure to compact the prepreg at the connection between the beam and the support base. However, due to the certain elasticity of the foam, the pressure transmitted to the connection position is insufficient, which causes problems with the density of the product, thereby affecting the overall strength of the product. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a composite material antenna beam, a preparation method thereof, and a rail vehicle, so as to avoid surface defects during the preparation process, improve the forming quality, and ensure the mechanical properties of the product.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] In a first aspect, a method for preparing a composite material antenna beam comprises the following steps:

[0008] S1. Prepare the beam;

[0009] S2. Laying fiber composite material on the surface of the mounting seat mold core to obtain the inner layer of the mounting seat;

[0010] S3, gluing the crossbeam to the inner layer of the mounting seat, and then laying a fiber composite material on the outer side of the whole formed by the crossbeam and the inner layer of the mounting seat to obtain a middle layer of the mounting seat;

[0011] S4, subjecting the mounting seat mold core, the mounting seat inner layer, the crossbeam and the mounting seat middle layer to autoclave forming;

[0012] S5. Apply glue to the outer side of the cured middle layer of the mounting base and then lay the fiber composite material to obtain the outer layer of the mounting base. Perform autoclave forming on the entire device to obtain the composite antenna beam.

[0013] Optionally, the fiber composite material includes carbon fiber unidirectional tape prepreg and carbon fiber cloth, and the resin matrix is ​​one of a thermosetting resin and a thermoplastic resin.

[0014] Optionally, in S1, the preparation method of the beam includes one or more of a molding and blowing process, a three-dimensional weaving process, a tube rolling process, and a pultrusion process.

[0015] Optionally, in S2, 3K twill fabric and T700 unidirectional tape prepreg are laid in sequence from the inside to the outside, and the thickness of the inner layer of the mounting base is 1.5 to 3 mm.

[0016] Optionally, in S3, after laying the epoxy mold in the set area of ​​the inner layer of the mounting base, a positioning tool is used to fix the beam to connect the beam to the inner layer of the mounting base.

[0017] Optionally, in S3, after applying the film on the surface of the paving area between the inner layer of the mounting seat and the crossbeam, T700 unidirectional tape prepreg and 3K twill fabric are laid in sequence from the inside to the outside, and the thickness of the middle layer of the mounting seat is 4 to 6 mm.

[0018] Optionally, in S4, the mounting seat mold core, the mounting seat inner layer, the crossbeam and the mounting seat middle layer are loaded into the first vacuum system, and then the first vacuum system is sent into the autoclave for curing and forming. The process parameters of the curing process include: pressure 0.6~0.8Mpa, temperature at 80~90℃ for 1~2h and then at 130~150℃ for 3~4h.

[0019] Optionally, in S5, T700 unidirectional tape prepreg and 3K twill fabric are laid sequentially from the inside to the outside, and the thickness of the outer layer of the mounting base is 1.5 to 3 mm.

[0020] Optionally, in S5, the device including the mounting seat mold core, the mounting seat inner layer, the crossbeam, the mounting seat middle layer and the mounting seat outer layer is loaded into the second vacuum system as a whole, and then the second vacuum system is sent into the autoclave for curing and forming. The process parameters of the curing process include: pressure 0.6~0.8Mpa, temperature at 80~90℃ for 1~2h and then at 130~150℃ for 3~4h.

[0021] Optionally, the method further includes step S6, removing the antenna beam formed into one piece by hot pressing from the mold core, and gluing a base plate to the bottom of the mounting base.

[0022] In a second aspect, a composite material antenna beam is prepared by the above-mentioned method for preparing the composite material antenna beam.

[0023] In a third aspect, a rail vehicle includes a bogie, on which the composite material antenna beam is provided.

[0024] The beneficial effects of the present invention are:

[0025] 1. The composite antenna beam provided by the present invention is formed using an autoclave process. The middle portion of the beam is wrapped between the inner and middle layers of the mounting base's layup structure, resulting in a large effective contact area. Furthermore, since the mounting base is not yet solidified during layup, the tightness of the two surfaces' fit can be effectively improved, avoiding dimensional deviations and internal voids in the product caused by separate forming of the two, thereby increasing the connection strength between the beam and the support base. Furthermore, a variety of fiber composite materials are used for laying. Unidirectional tape prepreg is used to provide mechanical properties, and twill, as a two-dimensional fabric, has good tension in all directions. This effectively prevents wrinkles in the internal unidirectional tape during autoclave forming, thereby effectively improving the flatness of the layup structure in the product and reducing internal defects. The autoclave forming process can apply uniform pressure to all locations of a complex-shaped mounting base, meeting product density requirements.

[0026] 2. During the manufacturing process, the mounting base is laid using the core mold shape and the beam profile. This allows for effective adjustment of the mounting range on the beam during the process, making it suitable for products with varying mechanical strength requirements. A larger mounting range results in a larger effective contact area, while a smaller mounting range results in a smaller effective contact area. This simplifies operation and reduces equipment requirements.

[0027] 3. The present invention uses a fiber composite material with a thermosetting resin matrix. After each curing and molding, a layer of epoxy film is first laid on the surface of the product to improve the adhesion between the subsequent prepreg and the cured product. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0029] Figure 1 Schematic diagram of the structure of the composite material antenna beam in Example 1, including (a) a schematic diagram of the connection relationship structure and (b) an exploded view.

[0030] Figure 2 This is a schematic structural diagram of the molding tooling in Example 1.

[0031] Figure 3 Schematic diagram of the preparation of the inner layer of the mounting base in Example 1.

[0032] Figure 4 Schematic diagram of the bonding preparation between the inner layer of the mounting base and the crossbeam in Example 1.

[0033] Figure 5 Schematic diagram of the preparation of the middle layer of the mounting base in Example 1.

[0034] Figure 6 This is a schematic diagram of the preparation of the first vacuum system in Example 1.

[0035] Figure 7 Schematic diagram of the preparation of the outer layer of the mounting base in Example 1.

[0036] Among them, 1. crossbeam; 2. mounting seat; 21. inner layer of mounting seat; 22. middle layer of mounting seat; 23. outer layer of mounting seat; 3. bottom plate; 4. flat plate; 5. mounting seat mold core; 6. supporting fixture; 7. positioning plate; 8. first vacuum system. DETAILED DESCRIPTION

[0037] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0038] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0039] A method for preparing a composite material antenna beam comprises the following steps:

[0040] S1. Prepare the beam;

[0041] S2. Laying fiber composite material on the surface of the mounting seat mold core to obtain the inner layer of the mounting seat;

[0042] S3, gluing the crossbeam to the inner layer of the mounting seat, and then laying a fiber composite material on the outer side of the whole formed by the crossbeam and the inner layer of the mounting seat to obtain a middle layer of the mounting seat;

[0043] S4, subjecting the mounting seat mold core, the mounting seat inner layer, the crossbeam and the mounting seat middle layer to autoclave forming;

[0044] S5. Apply glue to the outer side of the solidified mounting base middle layer and lay fiber composite material to obtain the mounting base outer layer. Perform autoclave forming on the mounting base mold core, mounting base inner layer, crossbeam, mounting base middle layer and mounting base outer layer to obtain the composite antenna beam.

[0045] In this process, the middle and outer layers of the mounting base are laid out in the shape of the beam, allowing for a tightly connected antenna beam. This avoids dimensional deviations and internal voids that might otherwise occur if the two were formed separately. This improves the connection strength between the beam and the mounting base, effectively optimizing the stress distribution between the beam and the mounting base, and ultimately enhancing overall performance, including impact, vibration, and static loads.

[0046] Optionally, the fiber composite material includes carbon fiber unidirectional tape prepreg and carbon fiber cloth, the resin matrix is ​​a thermosetting resin, the carbon fiber unidirectional tape prepreg is mainly used to provide mechanical strength according to the fiber orientation, and the carbon fiber cloth, as a two-dimensional or three-dimensional fabric, can withstand tension in all directions and can maintain a smooth surface during the autoclave forming process to avoid wrinkles and defects; and the carbon fiber cloth itself has beautiful patterns and can improve the quality of the outer tube.

[0047] Optionally, the carbon fiber unidirectional tape prepreg includes one or more of T300 unidirectional tape prepreg, T700 unidirectional tape prepreg, T800 unidirectional tape prepreg, and T1000 unidirectional tape prepreg; the carbon fiber cloth includes one or more of 3K twill cloth, 3K plain cloth, 12K twill cloth, and 12K twill cloth.

[0048] Optionally, the resin matrix includes one or more of thermosetting epoxy resin, thermosetting phenolic resin, thermoplastic polypropylene, and thermoplastic polyetheretherketone.

[0049] Optionally, in S1, the preparation method of the beam includes: one of: molding and blowing, molding and blowing process, three-dimensional weaving process, tube rolling process, and pultrusion process. The prepared beam has a hollow structure with mounting holes or adhesive connectors at both ends for installing the antenna support.

[0050] Optionally, in S2, 3K twill fabric and T700 unidirectional tape prepreg are laid in sequence from the inside to the outside, and the thickness of the inner layer of the mounting seat is 1.5 to 3 mm. After demoulding, the inner twill fabric is located on the surface of the mounting seat, which has an aesthetic effect.

[0051] Optionally, in S3, after laying glue in the set area of ​​the inner layer of the mounting seat, the positioning tool is used to fix the beam to connect the beam to the inner layer of the mounting seat. Specifically, a structural adhesive film is set in the contact area between the beam and the mounting seat. Since the thermosetting resin beam has been produced, the structural adhesive film is required to improve the connection strength between the beam and the mounting seat. The structural adhesive film can be selected from a medium-temperature epoxy adhesive film.

[0052] Optionally, the bonding surface of the beam is subjected to surface treatment including grinding and cleaning before being connected to the inner layer of the mounting seat. The positioning fixture is used to limit the position of the beam relative to the mounting seat (mold) from six degrees of freedom.

[0053] Optionally, in S3, T700 unidirectional tape prepreg and 3K twill fabric are laid in sequence from the inside to the outside in the paving area on the surface of the beam to form the middle layer of the mounting seat. The paving thickness of the middle layer of the mounting seat is 4 to 6 mm. The gluing method is to set a structural adhesive film. The main function of the twill fabric here is to prevent the paving structure from wrinkling in the autoclave.

[0054] Optionally, in S4, the mounting base mold core, mounting base inner layer, crossbeam, and mounting base middle layer are loaded into a first vacuum system, which is then placed in an autoclave for curing. The curing process parameters include: a pressure of 0.6-0.8 MPa, a temperature of 80-90°C for 1-2 hours, and then a temperature of 130-150°C for 3-4 hours. The first vacuum system includes a barrier film, a breathable felt, a vacuum bag, and a sealing strip. The first vacuum system completely covers the mounting base middle layer and is used to apply uniform pressure to the mounting base inner layer and the mounting base middle layer during autoclave curing. The barrier film protects the outer surface of the mounting base middle layer; the breathable felt forms gas flow channels on the outer surface of the mounting base middle layer, evacuating air from various locations in the vacuum bag; the vacuum bag is airtight and creates a vacuum environment; and the sealing strip seals the interfaces of the vacuum bag.

[0055] Optionally, in S5, the gluing method is to set a structural adhesive film, and lay T700 unidirectional tape prepreg and 3K twill fabric in sequence from the inside to the outside. The outer layer thickness of the mounting base is 1.5 to 3 mm. The main function of the twill fabric here is to prevent wrinkles in the laid structure in the autoclave and to form a beautiful outer surface.

[0056] Optionally, in S5, the device including the mounting seat mold core, the mounting seat inner layer, the crossbeam, the mounting seat middle layer and the mounting seat outer layer is loaded into the second vacuum system as a whole, and then the second vacuum system is sent to the autoclave for curing and forming. The process parameters of the curing process include: pressure 0.6~0.8Mpa, temperature at 80~90℃ for 1~2h and then at 130~150℃ for 3~4h; the second vacuum system includes an isolation film, a breathable felt, a vacuum bag and a sealing strip. The second vacuum system completely covers the mounting seat outer layer and is used to apply uniform pressure to the mounting seat inner layer and the mounting seat middle layer during hot pressing and curing in the autoclave; wherein, the isolation film is used to protect the outer surface of the mounting seat outer layer; the breathable felt is used to form a gas flow channel from the outer surface of the mounting seat outer layer, and to draw air from various positions of the vacuum bag; the vacuum bag is airtight and is used to form a vacuum environment; the sealing strip is used to seal the interface of the vacuum bag.

[0057] Optionally, the method further includes step S6, removing the antenna beam formed into one piece by hot pressing from the mold core, and gluing a base plate to the bottom of the mounting base, where the base plate is used to mount the antenna beam to the vehicle connection structure.

[0058] The composite material antenna beam is prepared by the above-mentioned method for preparing the composite material antenna beam.

[0059] A rail vehicle comprises a bogie, on which the composite material antenna beam is provided.

[0060] Example

[0061] A composite antenna beam, such as Figure 1 As shown in (a) of FIG. , it includes a beam 1, a mounting base 2 and a base plate 3. Figure 1 As shown in (b), the crossbeam 1 and the base plate 3 can be formed separately. Since the mounting seat 2 is prepared and formed with the participation of the crossbeam 1, it can fit tightly with the crossbeam 1 with basically no dimensional error. Accordingly, the mounting seat 2 and the crossbeam 1 cannot actually be separated.

[0062] The molding tool used in this embodiment is as follows Figure 2 As shown, it includes a flat plate 4, a mounting seat core 5, a support clamp 6 and a positioning plate 7. The flat plate 4 can be used as a paving operation table, the mounting seat core 5 is used for forming the mounting seat 2, the support clamp 6 is used for clamping the crossbeam 1 and its position is adjustable, and the positioning plate 7 is used as a reference to adjust the support clamp 6 to a set position; since the mounting seat core 5 and the support clamp 6 have a set relative position, the crossbeam 1 and the mounting seat inner layer 21 have a precise relative position when glued.

[0063] The preparation method comprises the following steps:

[0064] S1. Prepare a crossbeam 1 using carbon fiber T700 unidirectional tape prepreg and carbon fiber 3K twill fabric. The resin matrix is ​​a thermosetting resin. After curing, it becomes a crossbeam product for the next step.

[0065] S2, paving 3K twill cloth and T700 unidirectional tape prepreg on the surface of the mounting seat mold core 5 from the inside to the outside in sequence to form Figure 3 The light blue portion is the mounting seat inner layer 21 covering the surface of the mounting seat mold core 5, and has a paving thickness of 2 mm;

[0066] S3, such as Figure 4 As shown, after the structure film is applied to the set area of ​​the inner layer 21 of the mounting seat, the green beam 1 is fixed with the support fixture 6, and the beam 1 is glued to the inner layer 21 of the mounting seat. Figure 5As shown, T700 unidirectional tape prepreg and 3K twill fabric are laid in sequence from the inside to the outside in the paving area on the surface of the beam 1 to form a blue mounting seat middle layer 22. The mounting seat middle layer 22 has a thickness of 5 mm and covers the inner light blue mounting seat inner layer 21.

[0067] S4, such as Figure 6 As shown, the mounting seat core 5, the mounting seat inner layer 21, the crossbeam 1 and the mounting seat middle layer 22 are loaded into the first vacuum system 8. After the pressure is maintained and qualified, the first vacuum system 8 is sent to the autoclave for curing and forming. The process parameters of the curing process include: pressure of 0.7 MPa, temperature at 70°C for 2 hours and then at 140°C for 3.5 hours; the first vacuum system 8 includes an isolation film, a breathable felt, a vacuum bag and a sealing strip, which are conventional settings in the field. The first vacuum system 8 completely covers the mounting seat middle layer 22 and is used to apply uniform pressure to the mounting seat inner layer 21 and the mounting seat middle layer 22 during hot pressing and curing in the autoclave for autoclave forming;

[0068] S5, such as Figure 7 As shown, after a structural adhesive film is applied to the outer side of the cured mounting seat middle layer 22, T700 unidirectional tape prepreg and 3K twill fabric are laid in sequence from the inside to the outside to obtain a mounting seat outer layer 23 with a thickness of 2 mm. On the flat plate 4, the device including the mounting seat core 5, the mounting seat inner layer 21, a part of the crossbeam 1, the mounting seat middle layer 22 and the mounting seat outer layer 23 is placed in a second vacuum system as a whole. After the pressure is maintained and qualified, the second vacuum system is sent to the autoclave for curing and forming. The process parameters of the curing process include: pressure of 0.7 MPa, temperature at 70°C for 2 hours and then at 140°C for 3.5 hours; the second vacuum system is set according to the first vacuum system 8, and the second vacuum system completely covers the mounting seat outer layer 23. The composite antenna beam is obtained by hot pressing and curing in the autoclave.

[0069] S6. Remove the antenna beam formed into one piece by hot pressing from the mold core, and adhere the bottom plate 3 to the bottom of the mounting base 2.

[0070] In S1, the crossbeam 1 is manufactured by a blow molding process. The manufactured crossbeam 1 has a hollow structure and is provided with mounting holes at both ends for mounting antenna supports.

[0071] The mounting base 2 of the present invention is formed into a product through three layers of lamination and two layers of curing. Figure 7As shown, the first layup produces the inner mounting base layer 21, followed by the second layup to produce the middle mounting base layer 22, followed by the first curing step. A third layup then forms the outer mounting base layer 23, followed by the second curing step. This results in a superior appearance and addresses the issue of insufficient strength in the direct connection between the beam body and the mounting base, which can lead to product damage in conventional molding processes. Compared to existing technologies, this solution achieves superior interlayer density and structural strength after molding. The product's strength meets the incremental level test requirements of the GB / T 21563 standard and can also meet the requirements of ultrasonic flaw detection.

[0072] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing a composite material antenna beam, characterized in that: The following steps are involved: S1. Prepare the beam; S2. Laying fiber composite material on the surface of the mounting seat mold core to obtain the inner layer of the mounting seat; S3, gluing the crossbeam to the inner layer of the mounting seat, and then laying a fiber composite material on the outer side of the whole formed by the crossbeam and the inner layer of the mounting seat to obtain a middle layer of the mounting seat; S4, subjecting the mounting seat mold core, the mounting seat inner layer, the crossbeam and the mounting seat middle layer to autoclave forming; S5. Apply glue to the outer side of the cured middle layer of the mounting base and then lay a fiber composite material to obtain the outer layer of the mounting base. Perform autoclave forming on the entire device to obtain a composite antenna beam. In S3, after applying glue to the set area of ​​the inner layer of the mounting base, a positioning tool is used to fix the crossbeam and connect the crossbeam to the inner layer of the mounting base; In S3, after applying glue on the surface of the paving area between the inner layer of the mounting base and the beam, T700 unidirectional tape prepreg and 3K twill fabric are laid in the paving area on the surface of the beam from the inside to the outside to form the middle layer of the mounting base. The thickness of the middle layer of the mounting base is 4~6mm.

2. The method for preparing a composite material antenna beam according to claim 1, wherein: The fiber composite material comprises carbon fiber unidirectional tape prepreg and carbon fiber cloth, and the resin matrix is ​​a thermosetting resin; In S1, the preparation method of the crossbeam includes one or more of a molding and blowing process, a three-dimensional weaving process, a tube rolling process, and a pultrusion process.

3. The method for preparing a composite material antenna beam according to claim 1, wherein: In S2, 3K twill fabric and T700 unidirectional tape prepreg are laid out from the inside out, and the thickness of the inner layer of the mounting base is 1.5~3mm.

4. The method for preparing a composite material antenna beam according to claim 1, wherein: In S4, the mounting base mold core, the mounting base inner layer, the crossbeam, and the mounting base middle layer are loaded into a first vacuum system, and then the first vacuum system is sent into an autoclave for curing and forming. The process parameters of the curing process include: pressure 0.6-0.8 MPa, temperature at 80-90°C for 1-2 hours, and then at 130-150°C for 3-4 hours.

5. The method for preparing a composite material antenna beam according to claim 1, wherein: In S5, T700 unidirectional prepreg and 3K twill fabric are laid out from the inside out, and the thickness of the outer layer of the mounting base is 1.5~3mm.

6. The method for preparing a composite material antenna beam according to claim 1, wherein: In S5, the device including the mounting seat mold core, the mounting seat inner layer, the crossbeam, the mounting seat middle layer and the mounting seat outer layer is loaded into the second vacuum system as a whole, and then the second vacuum system is sent into the autoclave for curing and forming. The process parameters of the curing process include: pressure 0.6~0.8Mpa, temperature preservation at 80~90℃ for 1~2h and then preservation at 130~150℃ for 3~4h.

7. The method for preparing a composite material antenna beam according to claim 6, wherein: The method comprises step S6 of removing the antenna beam formed into one piece by hot pressing from the mold core, and gluing a base plate to the bottom of the mounting base.

8. A composite material antenna beam prepared by the method for preparing a composite material antenna beam according to any one of claims 1 to 7.

9. A rail vehicle comprising a bogie, characterized in that: The bogie is provided with the composite antenna beam according to any one of claims 1 to 7.

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