Manufacturing method of unmanned aerial vehicle conformal antenna vertical tail structure

Abstract

The application relates to a manufacturing method of a UAV conformal antenna vertical tail structure and belongs to the field of UAV conformal antenna integrated manufacturing. The method introduces a polymethacrylimide foam core material into the inside of a UAV vertical tail, divides the vertical tail into a left core body and a right core body, lays a radiation plate and glass fiber prepreg on the surface of the left core body and the right core body in sequence, and forms a foam sandwich structure composite vertical tail through autoclave curing forming. The left core body and the right core body are preformed with an antenna mounting groove, a cable groove and an equipment mounting hole, integrated installation of an antenna assembly can be realized, the vertical tail forming process is simplified, the forming efficiency is improved, the cable positioning stability is effectively improved, and electromagnetic performance decline caused by vibration and displacement is reduced.

Description

Technical Field

[0001] This invention relates to the field of conformal antenna integration manufacturing for unmanned aerial vehicles (UAVs), and specifically to a method for manufacturing a conformal antenna vertical tail structure for UAVs. Background Technology

[0002] Conformal antennas, as a type of antenna that blends into the surface of an aircraft, offer advantages such as good stealth performance, light weight, and compact structure. They can enhance the communication and detection capabilities of UAVs while maintaining an aerodynamic shape. Placing a conformal antenna at the UAV's vertical tail not only helps reduce the obstruction of electromagnetic signals by the aircraft but also utilizes the spatial shape of the protruding tail to achieve more stable signal coverage.

[0003] In existing technologies, the vertical tail of UAVs typically employs a composite material beam-rib structure. While this type of structure meets basic strength and stiffness requirements, it has certain shortcomings in manufacturing processes. The composite material beam-ribs usually need to be molded separately and then connected to the skin via secondary adhesive bonding, resulting in a complex process and low manufacturing efficiency. When integrating conformal antennas, this structure lacks simplified installation methods and effective measures for securing the feed lines, making the antenna cables susceptible to displacement or vibration during use, thus affecting electromagnetic performance and reliability.

[0004] Invention patent CN 116365229 A proposes "a 3D-printed conformal antenna skin structure and manufacturing method using composite materials," which uses 3D printing to manufacture a conformal antenna skin structure in the form of horizontal and vertical grids. This method simplifies the complex molding and bonding process of traditional beam-rib structures to some extent, improving manufacturing efficiency. However, limited by the current forming quality and material properties of 3D-printed composite materials, its overall mechanical strength is insufficient compared to traditional composite material processes. Furthermore, the horizontal and vertical grid structure does not provide effective constraints for the arrangement and fixation of antenna feed lines or RF cables, and the cables may still experience displacement or vibration during use, leading to insufficient electromagnetic performance stability.

[0005] This shows that there is still room for improvement in the existing UAV vertical tail structure in terms of ease of manufacturing and adaptability to antenna integration.

[0006] Therefore, there is a need to provide a method for manufacturing a conformal antenna vertical tail structure for UAVs to solve the above problems. Summary of the Invention

[0007] The technical problem to be solved:

[0008] To avoid the shortcomings of existing technologies, this invention provides a method for manufacturing a conformal antenna vertical tail structure for unmanned aerial vehicles (UAVs), and a method for manufacturing a vertical tail structure adapted to the installation of a conformal antenna, thereby solving the problems of complex manufacturing of existing composite material vertical tail structures and insufficient reliability of cable fixing when integrated with antennas.

[0009] The technical solution of this invention is: a method for manufacturing a conformal antenna vertical tail structure for a UAV, used to manufacture a conformal antenna vertical tail structure for a UAV; the vertical tail structure includes a left core, a right core, a left inner skin, a right inner skin, a radiating plate, and an outer skin; the left core and the right core have the same external shape, each with one side being a plane and the other side being an arc-shaped surface, the plane sides of the left core and the right core are joined together to form the core of the vertical tail, the left core and the right core are provided with antenna mounting slots, cable slots, and equipment mounting holes for mounting conformal antenna components; the left inner skin covers the arc-shaped surface of the left core, the radiating plate is attached to the arc-shaped surface of the right core, the right inner skin covers and adheres to the outer side of the radiating plate and the arc-shaped surface of the right core; the outer skin is entirely covered by the outer layer of the left inner skin and the right inner skin after the two cores are joined together;

[0010] The manufacturing method includes the following steps:

[0011] Design and manufacture metal molds, which are used for the final curing and shaping after the outer skin is covered;

[0012] Foam material is selected, and the left and right cores, as well as the antenna mounting groove, cable groove and equipment mounting hole on them, are processed by CNC machining to obtain the finished left and right cores;

[0013] On a piece of high-temperature resistant flat glass, the left core, left inner skin raw materials, and curing auxiliary materials are sequentially layered and laid. The whole assembly is sealed in a vacuum bag and placed in an autoclave for curing and molding to obtain a left foam sandwich panel containing a left core and a left inner skin. On another piece of high-temperature resistant flat glass, the right core, radiant plate, right inner skin raw materials, and curing auxiliary materials are sequentially layered and laid. The whole assembly is sealed in a vacuum bag and placed in an autoclave for curing and molding to obtain a right foam sandwich panel containing a right core, radiant plate, and right inner skin.

[0014] The outer skin material is laid in the mold. The left foam sandwich panel is placed on the outer skin material in the mold. The flat side of the right foam sandwich panel is then joined and fixed with the flat side of the left foam sandwich panel to form an integral sandwich panel. The outer skin material exposed on the mold side is then flipped over to cover the integral sandwich panel. Curing auxiliary material is then laid on the outer skin material. The whole assembly is sealed in a vacuum bag and placed in a thermostatic precipitator for curing and molding to obtain the finished conformal antenna vertical tail of the UAV.

[0015] A further technical solution of the present invention is that the left inner skin material, the right inner skin material and the outer skin material are all glass fiber prepregs.

[0016] A further technical solution of the present invention is as follows: the antenna mounting slot is used to install the antenna, and the top of both the left core and the right core are provided with a recessed antenna mounting slot; the device mounting hole is used to install antenna-related electronic components, and the plane side where the left core and the right core meet is provided with a device mounting hole, the device mounting hole of the left core is a through hole, and the device mounting hole of the right core is a blind hole, and the device mounting holes of the left core and the right core correspond to each other; the cable groove is used to thread and fix the antenna feed line or radio frequency cable, and the plane side wall of both the left core and the right core is provided with a cable groove.

[0017] A further technical solution of the present invention is as follows: the cable groove of the right core includes a fastening section and a first loosening section. The width of the fastening section is the same as the diameter of the cable and is used to limit and fix the cable. The width of the first loosening section is greater than the diameter of the cable. The first loosening section allows the cable to move within the range defined by its width. One end of the fastening section is connected to the equipment mounting hole of the right core, and the other end is connected to the inlet of the first loosening section. The outlet of the first loosening section is located at the bottom of the right core. The cable groove of the left core includes a second loosening section, which is mirror-corresponding to the first loosening section.

[0018] A further technical solution of the present invention is as follows: when laying the left inner skin material, a slot corresponding to the left core antenna mounting slot and a through hole corresponding to the left core device mounting hole are cut out on it; when laying the right inner skin material, a slot corresponding to the right core antenna mounting slot is cut out on it; when laying the outer skin material, slots corresponding to the left core antenna mounting slot and the right core antenna mounting slot, and through holes corresponding to the left core device mounting hole are cut out on it.

[0019] A further technical solution of the present invention is as follows: the molding auxiliary materials include a non-porous release membrane, a pressure pad, and a breathable felt. The non-porous release membrane is used to prevent resin from overflowing from the glass fiber prepreg and to act as an isolation agent. The pressure pad is used to apply uniform pressure to the layup structure during the curing process. The breathable felt is used to form gas channels during vacuuming. The pressure pad is reusable and is made of rubber material. Its size is consistent with the arc surface size of the left and right core products. The non-porous release membrane and the breathable felt are disposable consumables.

[0020] A further technical solution of the present invention is: the method of sealing the right foam sandwich panel by vacuum bag during molding is as follows: the right core, the radiating plate, the right inner skin material, the non-porous isolation film, the pressure pad and the breathable felt are stacked sequentially on the flat glass by vacuum bag, and the contact surface between the vacuum bag and the flat glass is sealed with sealing tape, and the air tightness is checked to ensure that the requirements are met.

[0021] A further technical solution of the present invention is as follows: after the outer skin material is covered, the method of sealing it with a vacuum bag is as follows: remove the positioning block on the side of the mold, wrap the integral sandwich panel, non-porous isolation film, pressure pad and breathable felt stacked on the mold with a vacuum bag, and seal the contact surface between the vacuum bag and the mold with sealing tape, and check that the airtightness meets the requirements.

[0022] A further technical solution of the present invention is: the mold is a female mold, the cavity of the mold is consistent with the arc surface of the finished product of the vertical tail structure, and positioning blocks are fixed at both ends of the mold. The positioning blocks are used to limit the position of the left / right foam sandwich wall panels when they are placed in the mold.

[0023] A further technical solution of the present invention is as follows: During the curing and molding process in the autoclave, the heating rate of the autoclave is 2 ℃ / min. After heating to 120 ℃, it is kept at the temperature for 1 h and then cooled down at a rate of 2 ℃ / min until it is below 60 ℃. After being removed from the autoclave, it is allowed to cool naturally to room temperature. The entire process of curing and molding in the autoclave is continuously vacuumed, and the vacuum degree is required to reach above 0.08 MPa.

[0024] The beneficial effects of this invention are as follows: The manufacturing method of the conformal antenna tail structure for UAVs provided by this invention uses foam material as the left and right cores, which are joined together to form the foam core of the tail. By dividing the foam core into two halves and joining them together, it is convenient to process corresponding antenna mounting slots, equipment mounting holes, and cable slots on the foam core for mounting the antenna of the conformal antenna assembly, antenna-related electronic components, and antenna feed lines or RF cables. By attaching and curing glass fiber prepreg to the left and right cores respectively, left and right foam sandwich panels are formed. Finally, the left and right foam sandwich panels are cured together using a special mold through the outer layer of glass fiber prepreg to form the finished conformal antenna tail structure for UAVs. The antenna is installed through the antenna mounting slot at the top of the tail, and integrated electronic components are installed through the equipment mounting holes on the left and right cores. The through-hole structure of the equipment mounting hole in the left core forms an integrated electronic component mounting channel. The cable slots on the mating surfaces of the left and right cores ensure the stable installation of antenna feed lines or RF cables. This method not only ensures the ease of manufacturing the UAV's vertical tail structure, but also facilitates the integrated installation of antenna components, enabling the stable deployment of connecting cables (antenna feed lines or RF cables) between the antenna, antenna-related electronic components, and onboard computer, thus ensuring the stability of the antenna signal.

[0025] This method introduces a foam core material into the vertical tail structure and co-cures it with a composite material skin, forming a foam sandwich structure for the entire vertical tail. This simplifies the internal structure of the vertical tail, avoiding the separate molding and secondary bonding processes required for traditional beam-rib structures, resulting in a simpler manufacturing process and higher molding efficiency. Simultaneously, by pre-processing cable grooves within the foam core material, antenna feed lines or RF cables can be effectively embedded and fixed, thereby improving cable positioning stability and preventing electromagnetic performance degradation due to vibration or displacement. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of the conformal antenna vertical tail structure assembly for a UAV prepared according to the present invention;

[0028] Figure 2 for Figure 1 Sectional view of AA;

[0029] Figure 3 for Figure 1 BB section view;

[0030] Figure 4 This is a schematic diagram of the left core structure in this invention;

[0031] Figure 5 This is a schematic diagram of the right core structure in this invention;

[0032] Figure 6 This is a schematic diagram of the molding process of the right foam sandwich panel in this invention;

[0033] Figure 7 This is a schematic cross-sectional view of the metal mold structure used in this invention;

[0034] Figure 8 This is a schematic diagram of the final forming process of the vertical tail structure.

[0035] In the diagram: 1. Left core, 1-1. First antenna mounting slot, 1-2. First equipment mounting hole, 1-3. Second expansion section, 1-4. First mounting hole, 2. Right core, 2-1. Second antenna mounting slot, 2-2. Second equipment mounting hole, 2-3. Fastening section, 2-4. First expansion section, 2-5. Second mounting hole, 3. Left inner skin, 4. Right inner skin, 5. Radiation plate, 6. Outer skin, 7. Mold, 8. Flat glass, 9. Left inner skin raw material, 10. Left foam sandwich panel, 11. Right inner skin raw material, 12. Right foam sandwich panel, 13. Outer skin raw material, 14. Non-porous isolation membrane, 15. Pressure pad, 16. Breathable felt, 17. Vacuum bag, 18. Sealing tape, 19. Positioning block. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] An embodiment of the manufacturing method of a conformal antenna vertical tail structure for a UAV according to the present invention, wherein the method specifically manufactures, as shown in the embodiment of the present invention. Figure 1 The illustrated conformal antenna tail structure for unmanned aerial vehicles (UAVs) aims to integrate a conformal antenna onto the tail. This method involves introducing a polymethacrylamide foam core material inside the UAV tail, and then sequentially laying a radiating plate and glass fiber prepreg on its surface. The mixture is then cured in an autoclave to form a composite material tail with a foam sandwich structure. By pre-setting antenna mounting slots, equipment mounting holes for antenna-related electronic components, and cable slots for embedding and fixing RF cables within the foam core inside the tail, the integrated installation of the conformal antenna is achieved. Compared to traditional beam-ribbed tail structures, this method simplifies the manufacturing process, avoids secondary bonding, and has high molding efficiency. Simultaneously, it effectively improves cable positioning stability and reduces electromagnetic performance degradation caused by vibration and displacement in the integrated conformal antenna design.

[0038] like Figures 1-5As shown, the conformal antenna tail structure of the UAV includes: a left core 1, a right core 2, a left inner skin 3, a right inner skin 4, a radiating plate 5, and an outer skin 6. The left core 1 and right core 2 are blocks of foam material with identical shapes and are mirror images of each other. Both left core 1 and right core 2 have a flat side and an arc-shaped side. The flat sides of left core 1 and right core 2 are joined and fixed to form the core of the tail. The left core 1 and right core 2 are provided with antenna mounting slots, cable slots, and equipment mounting holes for mounting the conformal antenna assembly. The left inner skin 3 covers the arc-shaped surface of the left core 1, and the two surfaces are in contact. The radiating plate 5 is attached to the arc-shaped surface of the right core 2, and the two surfaces are in contact. The right inner skin 4 covers and attaches to the outer side of the arc-shaped surface of the radiating plate 5 and the right core 2. The outer skin 6 completely covers the outer layer of the left inner skin 3 and right inner skin 4 after the two cores are joined, forming a complete enclosure for the internal components. To ensure the installation of antenna components in the antenna mounting slots, cable slots, and equipment mounting holes of the two cores, corresponding slots are provided at the corresponding mounting locations on the left inner skin 3, right inner skin 4, and outer skin 6.

[0039] Specifically, such as Figure 4 , Figure 5 As shown, the antenna mounting slot is used to install the antenna. Both the left core 1 and the right core 2 have recessed antenna mounting slots at their tops. Two protrusions at the bottom of each antenna mounting slot are used to connect with the antenna mounting base. The left core 1 has a first antenna mounting slot 1-1 at its top, and the right core 2 has a second antenna mounting slot 2-1 at its top. The two mounting slots are mirror images of each other. When the left core 1 and right core 2 are connected, the first antenna mounting slot 1-1 and the second antenna mounting slot 2-1 connect to form a single mounting slot. The protrusions at the bottom of the two antenna mounting slots connect to form two integral protrusions, which are embedded in the antenna mounting base to achieve a mortise and tenon connection. The antenna is mounted on the mounting base, and the bottom of the antenna conforms to the overall mounting slot.

[0040] The mounting holes are used to install the antenna's electronic components. Both the left core 1 and the right core 2 have mounting holes on their mating planes. The mounting holes on the left core 1 are through holes, while those on the right core 2 are blind holes. The mounting holes on the left and right cores correspond to each other. Figure 2 , Figure 4As shown, the device mounting hole of the left core 1 is the first device mounting hole 1-2, which is a through hole that penetrates both the planar side and the arc-shaped side of the left core 1. The through hole structure forms a channel for loading and unloading electronic components and also serves a heat dissipation function. The device mounting hole of the right core 2 is the second device mounting hole 2-2, which is a blind hole with its open end facing and aligned with the first device mounting hole 1-2. When the left core 1 and the right core 2 are connected, the first device mounting hole 1-2 and the second device mounting hole 2-2 are connected. Some of the antenna's related electronic components, such as power amplifiers, are located in the first device mounting hole 1-2, and some are located in the second device mounting hole 2-2. To facilitate the loading and unloading of electronic components, slots corresponding to the first device mounting hole 1-2 are provided on the left inner skin 3 and outer skin 6.

[0041] Cable slots are used to embed and fix antenna feed lines or RF cables. Cable slots are provided on the planar sidewalls of both the left core 1 and the right core 2. For example... Figure 4 , Figure 5 As shown, the cable tray of the right core 2 includes a fastening section 2-3 and a first loosening section 2-4. The width of the fastening section 2-3 is the same as the diameter of the installed cable, used to limit and fix the cable. The width of the first loosening section 2-4 is greater than the diameter of the cable, allowing the cable to move within its width limit. One end of the fastening section 2-3 is connected to the equipment mounting hole of the right core 2, and the other end is connected to the inlet of the first loosening section 2-4. The outlet of the first loosening section 2-4 is located at the bottom of the right core 2. The fastening section 2-3 can prevent the cable from shaking and shifting, so as to achieve a stable connection between the cable and related electronic components and ensure the stability of antenna signal transmission. The first loosening section 2-4 ensures that the cable can move within the installation tolerance range when the vertical tail is connected to the body, which is convenient for installation. The cable tray of the left core 1 includes a second loosening section 1-3, which is mirror-corresponding to the first loosening section 2-4. When the left core 1 and the right core 2 are connected, the first expansion section 2-4 and the second expansion section 1-3 are spliced ​​together to form a cable passage. At the same time, the first equipment mounting hole 1-2 of the left core 1 is located close to the first antenna mounting slot 1-1. A connecting slot for accommodating cables is provided between the bottom of the first antenna mounting slot 1-1 and the first equipment mounting hole 1-2. Similarly, a connecting slot for accommodating cables is also provided between the second equipment mounting hole 2-2 and the second antenna mounting slot 2-1 of the right core 2. The connecting slots of the two cores are connected to form a cable passage.

[0042] To facilitate the overall installation of the vertical tail structure, such as Figure 1 , Figure 4 and Figure 5As shown, the left core 1 has two through first mounting holes 1-4, and the right core 2 has second mounting holes 2-5 corresponding to the two first mounting holes 1-4. At the same time, the left inner skin 3, the right inner skin 4, the radiating plate 5 and the outer skin 6 all have through holes corresponding to the first mounting holes 1-4 and the second mounting holes 2-5, so that the vertical tail structure as a whole forms two mounting holes, thus realizing the installation of the vertical tail structure as a whole with the UAV.

[0043] During antenna assembly installation, the antenna is fixedly installed in the antenna mounting slots of the two cores using the mounting bracket. The antenna-related electronic components are inserted into the equipment mounting holes of the two cores through the opening of the second equipment mounting hole 2-2 and fixed. The antenna feed line or RF cable connecting the antenna and electronic components is first fixed and limited by the fastening section 2-3 of the cable slot of the right core 2, then enters the cable loosening section of the two cores, and then enters the fuselage and connects to the onboard computer.

[0044] The manufacturing method of the conformal antenna vertical tail structure for this UAV includes the following steps:

[0045] Step 1. Design and manufacture metal mold 7. Based on the design dimensions of the tail structure, design the forming mold of the tail using CATIA 3D modeling software, specifically a female mold. The shape of mold 7 is consistent with the arc surface dimensions of the tail structure product. Mold 7 is used for the final curing and shaping of the tail after covering the outer skin.

[0046] The mold 7 is equipped with detachable positioning blocks 19 at both ends. These positioning blocks 19 are used to limit the position of the integral sandwich panel when it is installed in the mold. The mold 7 and positioning blocks 19 are manufactured by machining, using CNC milling to ensure a surface roughness of ≤1.6, thus meeting the surface quality requirements of the part and ensuring molding accuracy. The mold structure is as follows: Figure 7 As shown. In this embodiment, necessary positioning lines and detachable metal positioning blocks 19 are provided on the mold 7 to ensure the accurate positioning and assembly of the foam core, radiant plate 5, and inner and outer skin materials during the molding process.

[0047] Step 2. Process two foam cores. The foam material is selected; in this embodiment, Rohacell® 71WF polymethacrylimide foam, suitable for aerospace structures, is specifically chosen as the sandwich core material. This material has good specific strength and heat resistance, ensuring the dimensional stability and strength of the vertical tail.

[0048] The left core 1 and right core 2 are machined using CNC machining technology to obtain the finished products of left core 1 and right core 2, including their antenna mounting slots, cable slots and equipment mounting holes.

[0049] This embodiment specifically utilizes a CNC machine tool to cut and process the foam blocks, precisely shaping them according to a digital model, with processing accuracy controlled within ±0.1mm. The structures of the left core 1 and right core 2 are as follows: Figures 2-5 As shown, after machining the external shape, the left core 1 is machined with the first antenna mounting slot 1-1, the first equipment mounting hole 1-2, the second expansion section 1-3 of the cable trough, and the first mounting hole 1-4. The right core 2 is machined with the second antenna mounting slot 2-1, the second equipment mounting hole 2-2, the fastening section 2-3 of the cable trough, the first expansion section 2-4 of the cable trough, and the second mounting hole 2-5. After machining, the surfaces of the left core 1 and the right core 2 are trimmed and cleaned to remove cutting residue and chips, ensuring that the surface quality meets the requirements for subsequent bonding of the radiating plate 5 and laying of the composite material.

[0050] Step 3. Fabrication of pressure pad 15. Pressure pad 15 is used in the curing process of the tail structure as a process auxiliary component to ensure uniform pressure on the component during curing. In this embodiment, pressure pad 15 is manufactured according to the theoretical arc surface dimensions of the left core 1 (same as the right core 2), ensuring complete coverage of the arc surfaces of the left core 1 and right core 2. This ensures comprehensive coverage and uniform pressure on the foam core and glass fiber prepreg (i.e., the raw materials for the left inner skin 3, right inner skin 4, or outer skin 6) during the molding process, thus ensuring the quality of curing. AIRPAD HTX rubber is selected as the pressure pad material, and it is manufactured using existing general manufacturing methods. After curing according to the material properties, the external dimensions are processed.

[0051] Step 4. Form the left foam sandwich panel 10 and the right foam sandwich panel 12.

[0052] Molding the left foam sandwich panel 10: The left core 1, left inner skin material 9, non-porous isolation membrane 14, pressure pad 15, and breathable felt 16 are sequentially layered on a high-temperature resistant flat glass panel 8. When laying the left inner skin material 9, slots corresponding to the first antenna mounting slot 1-1 on the left core 1, through holes corresponding to the first equipment mounting holes 1-2 on the left core 1, and through holes corresponding to the first mounting holes 1-4 need to be cut into it. After laying, a vacuum bag 17 is used to wrap the sequentially stacked left core 1, left inner skin material 9, non-porous isolation membrane 14, pressure pad 15, and breathable felt 16 on the flat glass panel 8. The contact surface between the vacuum bag 17 and the flat glass panel 8 is sealed with sealing tape 18, forming a sealed space inside the vacuum bag. After verifying the airtightness, the above components, along with the vacuum bag 17 and the flat glass panel 8, are placed in an autoclave for curing and molding. The autoclave heating rate is 2 ℃ / min. After heating to 120 ℃, it is held at that temperature for 1 h and then cooled down at a rate of 2 ℃ / min until it reaches below 60 ℃. After removal from the autoclave, it is allowed to cool naturally to room temperature. The entire process of curing and molding in the autoclave is continuously vacuumed, with a required vacuum level of 0.08 MPa or higher. After cooling, the vacuum bag 17, flat glass 8, and molding auxiliary materials are removed. The surface of the part is then corrected and cleaned to obtain a left foam sandwich panel 10, including a left core 1 and a left inner skin 3 (the curing and molding process of the left foam sandwich panel is not illustrated; please refer to [reference needed]). Figure 6 (Schematic diagram of the molding process of the right foam sandwich panel).

[0053] The molding auxiliary materials include a non-porous release liner 14, a pressure pad 15, and a breathable felt 16. The non-porous release liner 14 prevents resin from overflowing from the glass fiber prepreg and acts as a barrier between the product and the auxiliary materials. The pressure pad 15 applies uniform pressure to the layup structure during curing to ensure molding accuracy. The breathable felt 16 forms gas channels during vacuuming to ensure efficient vacuuming and uniform curing. The pressure pad 15 is the same as the one produced in step 3 and is reused during curing. The non-porous release liner 14 and the breathable felt 16 are disposable consumables.

[0054] The molding of the right-side foam sandwich panel 12 is basically the same as described above, except that the right-side foam sandwich panel 12 has an additional radiant plate 5. For example... Figure 6As shown, the right core 2, radiant plate 5, right inner skin material 11, non-porous isolation film 14, pressure pad 15, and breathable felt 16 are sequentially layered on another high-temperature resistant flat glass 8. Specifically, during the laying process, a 0.03mm thick radiant plate 5 is first adhered to the curved surface of the right core 2. Then, a layer of glass fiber prepreg (i.e., right inner skin material 11) is adhered to the outer surface of the radiant plate 5. Epoxy films are placed between the radiant plate 5 and the right core 2, and between the radiant plate 5 and the right inner skin material 11. These epoxy films enhance the interlayer bonding strength and ensure the reliability of the interfaces between the radiant plate 5, the right core 2, and the right inner skin material 11. Then, the non-porous isolation film 8, pressure pad 9, and breathable felt 10 are sequentially laid on the outside of the right inner skin material 11 to construct a complete curing auxiliary layer system. When laying the right inner skin material 11, slots corresponding to the second antenna mounting slot 2-1 on the right core 2 and through holes corresponding to the second mounting hole 2-5 are cut into it. After the installation is completed, the right core 2, radiating plate 5, right inner skin material 11, non-porous isolation membrane 14, pressure pad 15, and breathable felt 16, which are stacked sequentially on the flat glass 8, are wrapped in a vacuum bag 17. The contact surface between the vacuum bag 17 and the flat glass 8 is sealed with sealing tape 18 to form a sealed space inside the vacuum bag. After checking the airtightness, the above components, along with the vacuum bag 17 and the flat glass 8, are placed in an autoclave for curing. The autoclave is heated at a rate of 2℃ / min, and after reaching 120℃, it is held at that temperature for 1 hour and then cooled at a rate of 2℃ / min until it reaches below 60℃. After removal from the autoclave, it is allowed to cool naturally to room temperature. The entire curing process in the autoclave is carried out under vacuum, with a vacuum level required to be above 0.08MPa. After cooling after being taken out of the furnace, the vacuum bag 17, flat glass 8 and molding auxiliary materials are removed, and the surface of the part is corrected and cleaned to obtain the right foam sandwich panel 12, which includes the right core 2, the radiating plate 5 and the right inner skin 4.

[0055] Step 5. Integral Shaping of the Tail. The outer skin material 13, which is glass fiber prepreg, is laid inside mold 7. The left foam sandwich panel 10 and right foam sandwich panel 12, prepared in Step 4, are placed in mold 7 according to the designed positioning reference. The left and right foam sandwich panels 10 and 12 are connected by an epoxy film to ensure accurate installation within the mold cavity. After the planar sides of the left and right foam sandwich panels 10 and 12 are butted and fixed, an integral sandwich panel is formed. After placement, the outer skin material 13 exposed on one side of mold 7 is folded over to cover the outer surface of the right foam sandwich panel 12, thus forming a continuous outer skin covering structure. Then, a non-porous release film 14, a pressure pad 15, and a breathable felt 16 are sequentially stacked and laid on the upper outer skin material 13 to construct a complete curing auxiliary system. When laying the outer skin material 13, corresponding slots or through holes need to be cut on it to correspond to the first antenna mounting slot 1-1, the first equipment mounting hole 1-2, the first mounting hole 1-4, the second antenna mounting slot 2-1, and the second mounting hole 2-5. After laying, remove the positioning blocks 19 on the side of the mold 7, wrap the vacuum bag 17 around the integral sandwich panel, the non-porous isolation membrane 14, the pressure pad 15, and the breathable felt 16 stacked on the mold 7, and seal the contact surface between the vacuum bag 17 and the mold 7 with sealing tape 18. After checking that the airtightness is qualified, place the above components as a whole in a thermostatic precipitator for curing. The airtightness can be checked by vacuum pumping to ensure that the sealing performance meets the curing requirements. During the curing process, the outer skin material 13, i.e., the glass fiber prepreg, forms the outer skin layer and achieves integral co-curing with the internal integral sandwich panel. During curing, the autoclave is heated at a rate of 2 °C / min, held at 120 °C for 1 hour, and then cooled at a rate of 2 °C / min until it reaches below 60 °C. After removal from the autoclave, it is allowed to cool naturally to room temperature. The entire curing process in the autoclave is carried out under vacuum, with a required vacuum level of 0.08 MPa or higher. After cooling, the vacuum bag 17, mold 7, and molding auxiliary materials are removed. The cured material is then shaped and cleaned to obtain the finished conformal antenna vertical tail structure for the UAV.

[0056] It should be noted that when covering the core with inner and outer skins, only the outer curved surface needs to be covered. The top surface of the vertical tail structure is only used for flanging at the antenna mounting location; the bottom of the vertical tail and the mounting of the fuselage can also be left uncovered. If the top and bottom of the vertical tail structure need to be covered, it is necessary to ensure that the antenna mounting slot at the top and the cable slot at the bottom are unobstructed and do not affect the installation of the antenna components.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a conformal antenna vertical tail structure for an unmanned aerial vehicle (UAV), characterized in that, This structure is used to manufacture the conformal antenna vertical tail structure for unmanned aerial vehicles (UAVs). The vertical tail structure includes a left core, a right core, a left inner skin, a right inner skin, a radiating plate, and an outer skin. The left and right cores have the same external shape, with one side being a flat surface and the other side being an arc-shaped surface. The flat sides of the left and right cores are joined together to form the core of the vertical tail. The left inner skin covers the arc-shaped surface of the left core, and the radiating plate is attached to the arc-shaped surface of the right core. The right inner skin covers and adheres to the outer side of the radiating plate and the arc-shaped surface of the right core. The outer skin completely covers the outer layer of the left and right inner skins after the two cores are joined together. Both the left and right cores have recessed antenna mounting slots at their top for mounting antennas. The mating planes of the left and right cores also have device mounting holes for mounting antenna-related electronic components. The device mounting holes on the left core are through holes, while those on the right core are blind holes, and they correspond to each other. Both the left and right cores also have cable grooves on their planar sidewalls for threading and fixing antenna feed lines or RF cables. The cable slot of the right core includes a fastening section and a first loosening section. The width of the fastening section is the same as the diameter of the installed cable, which is used to limit and fix the cable. The width of the first loosening section is greater than the diameter of the cable, allowing the cable to move within the range defined by its width. One end of the fastening section is connected to the equipment mounting hole of the right core, and the other end is connected to the inlet of the first loosening section. The outlet of the first loosening section is located at the bottom of the right core. The cable slot of the left core includes a second loosening section, which is mirror-corresponding to the first loosening section. The manufacturing method includes the following steps: Design and manufacture metal molds, which are used for the final curing and shaping after the outer skin is covered; Foam material is selected, and the left and right cores, as well as the antenna mounting groove, cable groove and equipment mounting hole on them, are processed by CNC machining to obtain the finished left and right cores; On a piece of high-temperature resistant flat glass, the left core, left inner skin raw materials, and curing auxiliary materials are sequentially layered and laid. The whole assembly is sealed in a vacuum bag and placed in an autoclave for curing and molding to obtain a left foam sandwich panel containing a left core and a left inner skin. On another piece of high-temperature resistant flat glass, the right core, radiant plate, right inner skin raw materials, and curing auxiliary materials are sequentially layered and laid. The whole assembly is sealed in a vacuum bag and placed in an autoclave for curing and molding to obtain a right foam sandwich panel containing a right core, radiant plate, and right inner skin. The outer skin material is laid in the mold. The left foam sandwich panel is placed on the outer skin material in the mold. The flat side of the right foam sandwich panel is then joined and fixed with the flat side of the left foam sandwich panel to form an integral sandwich panel. The outer skin material exposed on the mold side is then flipped over to cover the integral sandwich panel. Curing auxiliary material is then laid on the outer skin material. The whole assembly is sealed in a vacuum bag and placed in a thermostatic precipitator for curing and molding to obtain the finished conformal antenna vertical tail of the UAV.

2. The manufacturing method of the conformal antenna vertical tail structure for a UAV according to claim 1, characterized in that, The raw materials for the left inner skin, right inner skin, and outer skin are all glass fiber prepregs.

3. The manufacturing method of the conformal antenna vertical tail structure for a UAV according to claim 1, characterized in that, When laying the left inner skin material, cut out the slots corresponding to the left core antenna mounting slot and the through holes corresponding to the left core equipment mounting holes; when laying the right inner skin material, cut out the slots corresponding to the right core antenna mounting slot; when laying the outer skin material, cut out the slots corresponding to the left core mounting slot, the right core mounting slot, and the through holes corresponding to the left core mounting holes.

4. The manufacturing method of the conformal antenna vertical tail structure for a UAV according to claim 2, characterized in that, The curing auxiliary materials include a non-porous release membrane, a pressure pad, and a breathable felt. The non-porous release membrane is used to prevent resin from overflowing from the glass fiber prepreg and to act as a barrier. The pressure pad is used to apply uniform pressure to the layup structure during the curing process. The breathable felt is used to form gas channels during vacuuming. The pressure pad is reusable and is made of rubber material. Its size is consistent with the arc surface size of the left and right cores. The non-porous isolation membrane and breathable felt are disposable consumables.

5. The manufacturing method of the conformal antenna vertical tail structure for a UAV according to claim 4, characterized in that, When forming the right foam sandwich panel, the method of sealing it with a vacuum bag is as follows: the right core, the radiating plate, the right inner skin material, the non-porous isolation membrane, the pressure pad and the breathable felt are stacked sequentially on the flat glass wrapped in the vacuum bag. The contact surface between the vacuum bag and the flat glass is then sealed with sealing tape, and the air tightness is checked to ensure it meets the requirements.

6. The manufacturing method of the conformal antenna vertical tail structure for a UAV according to claim 4, characterized in that, The mold is a female mold, and the cavity of the mold is consistent with the arc surface of the finished vertical tail structure. Positioning blocks are fixed at both ends of the mold. The positioning blocks are used to limit the position of the left / right foam sandwich panel when it is placed in the mold.

7. The manufacturing method of the conformal antenna vertical tail structure for a UAV according to claim 6, characterized in that, The method of sealing the outer skin material with a vacuum bag is as follows: remove the positioning block on the side of the mold, stack the integral sandwich panel, non-porous isolation film, pressure pad and breathable felt in sequence on the mold wrapped in the vacuum bag, and seal the contact surface between the vacuum bag and the mold with sealing tape. Check that the airtightness meets the requirements.

8. The method for manufacturing the conformal antenna vertical tail structure for a UAV according to claim 1, characterized in that, During the curing process in the autoclave, the heating rate of the autoclave is 2 ℃ / min. After heating to 120 ℃, it is held at that temperature for 1 h and then cooled down at a rate of 2 ℃ / min until it is below 60 ℃. After being removed from the autoclave, it is allowed to cool naturally to room temperature. The entire process of curing in the autoclave is continuously vacuumed, and the vacuum level is required to reach above 0.08 MPa.

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