A low-altitude manned aircraft rotor installation and containment box device and its manufacturing method

Abstract

The present invention provides a mounting and containment box device for the rotor blades of a low-altitude manned aircraft and a manufacturing method thereof. This mounting and containment box device, through the synergistic action of an outer shell, an intermediate layer, an inner shell, and an outer shell base, reduces aerodynamic noise, improves the attenuation rate of kinetic energy from debris impacts, and suppresses the transmission of high-frequency vibrations, thereby enhancing aircraft operational stability and passenger comfort. A magnetic quick-release connector is provided on the outer shell base, connecting the outer shell base to the aircraft fuselage via the connector. The outer shell has a streamlined aerodynamic outer wall, and a T-shaped guide rail is provided on the inner wall of the outer shell. The outer wall of the intermediate layer is provided with multiple T-shaped protrusions that mate with the T-shaped guide rails. The intermediate layer slides into the T-shaped guide rails of the outer shell via the T-shaped protrusions. The outer wall of the inner shell is provided with multiple clips that press into the inner side of the intermediate layer to connect the inner shell to the intermediate layer. The inner shell is used to accommodate the rotor blades.

Description

Technical Field

[0001] The present invention relates to the field of rotor installation, and in particular to a low-altitude manned aircraft rotor installation containing box device and a manufacturing method thereof. Background Art

[0002] With the rapid development of low-altitude manned aircraft, the safety and operating performance of the rotor system as a core power component have attracted much attention.

[0003] However, the existing technology still has the following key problems that need to be solved urgently: 1) Aerodynamic and mechanical noise problems: When the rotors of traditional low-altitude manned aircraft are in operation, broadband aerodynamic noise is generated due to the intense friction between the high-speed rotation and the air. At the same time, the mechanical vibrations are transmitted to the fuselage through the rigid structure, forming superimposed noise, which seriously affects the comfort of the occupants and the stability of the equipment. 2) Risk of secondary damage from broken rotor fragments: The rotor may break under extreme working conditions (such as foreign object impact, fatigue fracture), and the fragments will fly at high speed. The kinetic energy is transmitted to the fuselage through the rigid connection structure, causing secondary damage. Existing protection solutions mostly use a single material casing (such as a carbon fiber integral structure). Although it can improve the impact resistance, it lacks a layered energy absorption design, resulting in an insufficient kinetic energy attenuation rate of the fragments. In addition, the integral structure is difficult to repair and the maintenance cost is high.

[0004] Traditional casings are often integrally cast or filament-wound, making them incapable of adapting to rotor sizes of varying sizes. They also lack modular quick-release features, resulting in inefficient maintenance. For example, Chinese patent CN114643725B proposes a composite casing manufacturing method, but fails to integrate noise reduction and impact resistance, making it difficult to balance aerodynamic noise with debris protection.

[0005] Therefore, it is urgent to develop a novel low-altitude manned aircraft rotor installation containing box device to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to solve the noise problem during the operation of the rotor of a low-altitude manned aircraft and to improve the safety protection capability of the rotor broken fragments.

[0007] In order to achieve the above-mentioned object, the present invention proposes a low-altitude manned aircraft rotor installation containment box device, comprising:

[0008] An outer shell, wherein the outer wall of the outer shell is a streamlined aerodynamic shape, a plurality of T-shaped guide rails are provided on the inner wall of the outer shell, and a plurality of connecting protrusions are provided on the bottom of the outer shell;

[0009] An intermediate layer, wherein a plurality of T-shaped protrusions are provided on the outer wall of the intermediate layer, the T-shaped protrusions match the T-shaped guide rail, the intermediate layer is slidably embedded in the T-shaped guide rail through the T-shaped protrusions, a plurality of gradient honeycomb through holes are provided on the intermediate layer, the intermediate layer comprises an intermediate outer layer, an intermediate transition layer and an intermediate inner layer, the intermediate transition layer is provided between the intermediate outer layer and the intermediate inner layer, the T-shaped protrusions are provided on the outer wall of the intermediate outer layer, a plurality of first honeycomb through holes are provided on the intermediate outer layer, a plurality of second honeycomb through holes are provided on the intermediate transition layer, a plurality of third honeycomb through holes are provided on the intermediate inner layer, the aperture of the first honeycomb through hole is larger than the aperture of the second honeycomb through hole, the aperture of the second honeycomb through hole is larger than the aperture of the third honeycomb through hole, each first honeycomb through hole corresponds to a second honeycomb through hole and a third honeycomb through hole respectively to form a plurality of gradient honeycomb through holes;

[0010] An inner shell, wherein a plurality of buckles are provided on the outer wall of the inner shell, and the inner shell is pressed into the inner side of the middle layer through the buckles. The inner shell is used to accommodate the rotor, and the inner diameter of the inner shell is larger than the diameter of the rotor. The inner shell is provided with a plurality of circular through holes;

[0011] The outer shell base is provided with a plurality of connecting slots, the connecting slots match the connecting protrusions, the outer shell base is connected to the outer shell through the connecting slots, and the bottom of the outer shell base is provided with a magnetic quick-release connector, and the outer shell base is connected to the aircraft fuselage through the magnetic quick-release connector.

[0012] In one embodiment, an elastic damping layer is provided on the inner side of the inner shell, and the elastic damping layer includes a damping base layer, a damping intermediate layer and a damping contact layer. The damping base layer is adhered to the inner side of the inner shell, and the damping intermediate layer is provided between the damping base layer and the damping contact layer. The inner diameter of the damping contact layer is larger than the diameter of the rotor.

[0013] In one embodiment, the damping base layer is silicone, the damping intermediate layer is copper mesh, and the damping contact layer is fluororubber.

[0014] In one embodiment, a pressure sensor is installed between the outer shell and the middle layer to detect the distance between the installation box and the rotor. When the distance value is less than a preset distance threshold, an alarm is triggered. The distance threshold includes a warning value and a danger value. When the distance value is less than the warning value, a first alarm signal is triggered. When the distance value is less than the danger value, a second alarm signal is triggered and the machine automatically shuts down.

[0015] In one embodiment, the gradient honeycomb-shaped through holes have a radial gradient of 0.5 mm / mm and an axial gradient of 0.3 mm / mm, wherein the radial direction is along the thickness direction and the axial direction is perpendicular to the thickness direction.

[0016] In one embodiment, the low-altitude manned aircraft rotor mounting enclosure device is composed of a plurality of arc-shaped units, the number of the arc-shaped units is adjusted according to the size of the rotor, the outer shell is composed of a plurality of arc-shaped outer shell units, the middle layer is composed of a plurality of arc-shaped middle layer units, the inner shell is composed of a plurality of arc-shaped inner shell units, and the outer shell base is composed of a plurality of arc-shaped outer shell base units, and each arc unit includes an arc-shaped outer shell unit, an arc-shaped middle layer unit, an arc-shaped inner shell unit and an arc-shaped outer shell base unit.

[0017] In one embodiment, the plurality of arc-shaped units are spliced ​​together through a quick-release interface, the quick-release interface is a male-female tenon structure, and the quick-release interface is separated by magnetic unlocking.

[0018] In one embodiment, the low-altitude manned aircraft rotor mounting enclosure device has one or both of the following features:

[0019] The diameter of the mounting enclosure is 10% to 15% greater than the rotor diameter;

[0020] The weight of the mounting enclosure does not exceed 20% of the total weight of the rotor.

[0021] In one embodiment, the low-altitude manned aircraft rotor mounting enclosure device has one or more of the following features:

[0022] The outer shell is made of a carbon fiber reinforced polyamide matrix, and the outer wall of the outer shell is covered with a silicon dioxide coating;

[0023] In the intermediate layer, the material of the intermediate outer layer is aluminum alloy, the material of the intermediate transition layer is Kevlar / aluminum composite material, and the material of the intermediate inner layer is pure Kevlar;

[0024] The material of the inner shell is polyurethane foam or micro-perforated plate.

[0025] To achieve the above-mentioned object, the present invention further proposes a method for manufacturing a low-altitude manned aircraft rotor mounting containment box device, which is applied to the low-altitude manned aircraft rotor mounting containment box device as described above. The manufacturing method comprises the following steps:

[0026] S1, Preparation and Structural Forming of the Outer Shell: Selective laser sintering is used with a carbon fiber reinforced polyamide matrix as the material. The laser power is 80W and the layer thickness is 0.1mm. The streamlined aerodynamic carbon fiber outer shell is sintered layer by layer. The surface is coated with nano-silica. T-shaped guide rails are pre-installed on the inner wall of the outer shell.

[0027] S2, preparation and assembly of the middle layer: Digital light processing (DLP) prints a honeycomb mold with a gradient honeycomb aperture design. Vacuum-assisted resin infusion is used to inject Kevlar fiber / epoxy resin into the mold. After curing, gradient honeycomb-shaped through-holes are formed. Multiple T-shaped protrusions are set on the outer wall of the middle layer. The T-shaped protrusions slide and embed along T-shaped guide rails to form a self-locking mechanical interlock.

[0028] S3, forming and assembling the composite structure of the inner shell and the elastic damping layer: forming the inner shell by foaming a polyurethane foam, and hot-pressing the composite elastic damping layer on the inner side of the inner shell. A buckle is provided on the outer wall of the inner shell, and the inner shell is pressed into the inner side of the intermediate layer by the buckle;

[0029] S4, preparation and assembly of the outer shell base: The outer shell base is inserted into the connecting protrusion at the bottom of the outer shell through the connecting slot, and is connected to the aircraft fuselage through a magnetic quick-release connector.

[0030] The low-altitude manned aircraft rotor installation housing box device and the manufacturing method thereof of the present invention have the following beneficial effects:

[0031] 1. The device utilizes a gradient honeycomb perforated structure. Three layers of honeycomb perforations with varying apertures progressively attenuate noise, effectively reducing aerodynamic and mechanical noise and enhancing passenger comfort. Furthermore, the elastic damping layer utilizes a combination of silicone, copper mesh, and fluororubber to further absorb vibration energy, reduce noise conduction, and improve operational stability.

[0032] The device's multi-layered structure effectively absorbs and disperses the kinetic energy of rotor fragments, reducing the risk of secondary damage. An outer layer of carbon fiber-reinforced polyamide matrix and silica coating provides high-strength protection, while an intermediate layer of aluminum alloy, Kevlar / aluminum composite, and pure Kevlar achieves gradient energy absorption. An inner layer of polyurethane foam or micro-perforated sheeting further cushions the energy.

[0033] 3. The device adopts a modular design, consisting of multiple curved units connected via quick-release interfaces. This allows for adjustment to the rotor size, ensuring high adaptability. The magnetic quick-release connector at the base of the outer shell and the male and female tenon structures on the curved units enable rapid installation and removal, significantly improving maintenance efficiency and reducing costs. Furthermore, a pressure sensor monitors the clearance in real time to ensure safe operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1An exploded schematic diagram of a layered structure of a containment box device for installing a rotor of a low-altitude manned aircraft according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the overall structure of a low-altitude manned aircraft rotor installation containment box device according to one embodiment of the present invention;

[0036] Figure 3 A schematic diagram of the three-dimensional structure of the outer shell base of a low-altitude manned aircraft rotor installation containment box device according to one embodiment of the present invention;

[0037] Figure 4 A schematic front view of the outer shell base of a low-altitude manned aircraft rotor installation containment box device according to one embodiment of the present invention;

[0038] Figure 5 Schematic diagrams of the structure of the intermediate layer of a low-altitude manned aircraft rotor mounting containment box device according to one embodiment of the present invention, wherein (a) is a three-dimensional schematic diagram, (b) is a top view schematic diagram, (c) is a side view schematic diagram, (d) is an enlarged schematic diagram of point A1 in (b), and (e) is an enlarged schematic diagram of point A2 in (c);

[0039] Figure 6 Schematic diagrams of the structure of the inner shell of a low-altitude manned aircraft rotor mounting containment box device according to one embodiment of the present invention, wherein (a) is a three-dimensional schematic diagram, (b) is a top view schematic diagram, (c) is a side view schematic diagram, and (d) is an enlarged schematic diagram of point B in (c);

[0040] Figure 7 Schematic diagrams of the structure of the outer shell of a low-altitude manned aircraft rotor installation containment box device according to one embodiment of the present invention, wherein (a) is a top view thereof, (b) is a perspective view thereof, and (c) is a side view thereof;

[0041] Figure 8 The figure is a schematic structural diagram of an arc-shaped unit of a low-altitude manned aircraft rotor installation containment box device according to one embodiment of the present invention.

[0042] Reference numerals

[0043] 1-outer shell, 2-middle layer, 3-inner shell, 4-outer shell base, 5-arc unit, 11-T-shaped guide rail, 12-connecting protrusion, 21-T-shaped protrusion, 22-gradient honeycomb through hole, 31-clip, 32-circular through hole, 41-connecting slot, 42-magnetic quick-release connector. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the invention and are not intended to limit the invention.

[0045] like Figure 1 and Figure 2 As shown, the present invention proposes a low-altitude manned aircraft rotor installation and containment box device, comprising: an outer shell 1, an intermediate layer 2, an inner shell 3 and an outer shell base 4. The installation and containment box device is annular in shape. Figure 2 and Figure 7 As shown, the outer wall of the outer shell 1 is a streamlined aerodynamic shape, a plurality of T-shaped guide rails 11 are provided on the inner wall of the outer shell 1, and a plurality of connecting protrusions 12 are provided on the bottom of the outer shell 1.

[0046] like Figure 1 and Figure 5 As shown, the outer wall of the middle layer 2 is provided with multiple T-shaped protrusions 21. The T-shaped protrusions 21 mate with the T-shaped guide rails 11. The middle layer 2 slides into the T-shaped guide rails 11 of the outer shell via the T-shaped protrusions 21. The T-shaped protrusions 21 and the T-shaped guide rails 11 form a self-locking mechanical interlock, and the outer wall of the middle layer 2 contacts the inner wall of the outer shell 1. The middle layer 2 is provided with multiple gradient honeycomb-shaped through-holes 22. The middle layer 2 includes an outer middle layer, an intermediate transition layer, and an inner middle layer. The intermediate transition layer is provided between the outer middle layer and the inner middle layer. The T-shaped protrusions 21 are provided on the outer wall of the outer middle layer. The outer middle layer is provided with multiple first honeycomb-shaped through-holes, the intermediate transition layer is provided with multiple second honeycomb-shaped through-holes, and the inner middle layer is provided with multiple third honeycomb-shaped through-holes. The aperture of the first honeycomb-shaped through hole is larger than that of the second honeycomb-shaped through hole, and the aperture of the second honeycomb-shaped through hole is larger than that of the third honeycomb-shaped through hole. Each first honeycomb-shaped through hole corresponds to a second honeycomb-shaped through hole and a third honeycomb-shaped through hole to form a plurality of gradient honeycomb-shaped through holes 22, see Figure 5 .

[0047] The outer wall of the inner shell 3 is provided with a plurality of clips 31. The inner shell 3 is pressed into the inner side of the middle layer 2 through the clips 31 to achieve the connection between the inner shell 3 and the middle layer 2. The outer side of the inner shell 3 contacts the inner side of the middle layer 2. The inner shell 3 is used to accommodate the rotor. The inner diameter of the inner shell 3 is larger than the diameter of the rotor. The inner shell 3 is provided with a plurality of circular through holes 32. Figure 6 .

[0048] like Figure 1 and Figure 3 As shown, the outer shell base 4 is provided with a plurality of connecting slots 41, which match the connecting protrusions 12, and the outer shell base 4 is connected to the outer shell 1 through the connecting slots 41. Figure 4As shown, a magnetic quick-release connector 42 is provided at the bottom of the outer shell base 4, and the outer shell base 4 is connected to the aircraft fuselage via the magnetic quick-release connector 42. In this embodiment, the outer shell base 4 is connected to the aircraft engine via the magnetic quick-release connector 42.

[0049] In this embodiment, the T-shaped guide rail 11 is preferably 5 mm in height and 3 mm in width, providing a rigid sliding track for the middle layer 2, ensuring axial positioning accuracy and resisting circumferential torsion. The buckle 31 on the inner shell 3 is an elastic buckle made of 70A Shore hardness silicone, which has medium hardness and is both elastic and supportive. The elastic buckle provides a flexible locking force to compensate for tolerances and absorb vibrations, avoiding stress concentration caused by hard connections. The assembly sequence is as follows: First, the T-shaped protrusion of the middle layer is assembled and locked along the axial direction of the T-shaped guide rail. Then, the buckle on the inner shell is pressed vertically into the middle layer. After deformation, the buckle rebounds, generating a radial preload force, filling the gap and preventing separation between layers. Finally, a tightening torque of 150 N·m is applied circumferentially to the entire structure to further compact the interlocking surface between the T-shaped protrusion and the T-shaped guide rail, thereby improving the overall stiffness and interface strength.

[0050] In a specific embodiment, the outer shell base 4 includes a circular ring structure and a cylindrical structure. The circular ring structure is concentric with the cylindrical structure, and the inner side of the circular ring structure is connected to the outer side of the cylindrical structure through a connecting piece. Figure 3 The number of connectors is preferably four. A connecting slot 41 is provided on the annular structure, and a magnetic quick-release connector 42 is provided below the cylindrical structure. When the outer shell base 4 is connected to the outer shell 1, a bearing is placed above the cylindrical structure to support the mounting of the housing device, reduce the friction coefficient during its movement, and ensure its rotational accuracy.

[0051] In one specific embodiment, the connection between the outer shell 1 and the aircraft fuselage utilizes a dual-fixation solution consisting of a magnetic quick-release connector and a shape-memory alloy anti-dropout safety pin. The quick-release structure is implemented collaboratively by the following core components: Circumferentially distributed N45-grade neodymium iron boron (NdFeB) magnets (Φ10×3mm) provide a single-point magnetic attraction force of 80N. A 5° taper-type structure enables automatic centering under magnetic guidance, ensuring a radial positioning accuracy of ±0.1mm. After assembly, a shape-memory alloy anti-dropout safety pin, with an austenite transition point of 60°C, is manually inserted. This creates a rigid mechanical lock at room temperature, increasing the overall tensile strength to over 500N. When the system temperature abnormally rises to 60°C, the anti-dropout safety pin undergoes a phase change and contraction, achieving a thermally triggered emergency separation.

[0052] The outer wall of the outer shell 1 has a streamlined aerodynamic shape. In this embodiment, the Navier-Stokes equations are used as the physical basis for the simulation to reduce airflow separation and turbulence. Computational fluid dynamics (CFD) is also used for simulation analysis. The outer shell is designed with a profile similar to the NACA 64-418 airfoil, with a leading edge radius of 8 mm, meaning the radius of curvature at the front end of the airfoil is set to 8 mm. A smaller radius optimizes high-speed performance but requires balancing stall characteristics. The maximum thickness is located at 30% of the chord length, meaning the thickest point on the airfoil profile is located 30% of the chord length from the leading edge. This is a significant change from the original NACA 64-418, where the maximum thickness is typically around 40% of the chord length. This enhances leading edge stiffness, delays stall, and controls shock wave location. The trailing edge taper angle is 12°, meaning the upper and lower surfaces of the rear section of the airfoil taper inward at a 12-degree angle. The trailing edge taper angle affects the airfoil's rearward load distribution, wake structure, and drag. A relatively large taper angle helps accelerate the airflow near the trailing edge and reduce the aft adverse pressure gradient, thereby controlling the aft flow and reducing separation and turbulence. CFD (Computational Fluid Dynamics) simulations validated the k-ω SST turbulence model (Shear Stress Transport), where k represents the turbulent kinetic energy and ω represents the specific dissipation rate. The results showed a 38% reduction in separated vorticity at a Mach number of 0.15, quantifying the decrease in separation strength on the airfoil surface.

[0053] Furthermore, the number of the connecting protrusions 12 on the bottom of the outer shell 1 can be configured according to needs, while ensuring that the outer shell base 4 has the same number of connecting slots 41 .

[0054] In this embodiment, the outer shell 1 is preferably made of a carbon fiber reinforced polyamide matrix, and a silicon dioxide coating is applied to the outer wall of the outer shell 1. The impact strength of the outer shell 1 is increased by 40% and the weight is reduced by 25%.

[0055] The middle layer 2 is a gradient honeycomb energy absorbing structure, and a plurality of gradient honeycomb through holes 22 are provided on the middle layer 2. Figure 5 . Its radial gradient is 0.5 mm / mm, and radial generally refers to the direction along the thickness of the structure, that is, the direction from the outer surface to the inner surface. Its axial gradient is 0.3 mm / mm, and axial generally refers to the direction perpendicular to the thickness direction, that is, the direction along the plane of the honeycomb structure. In this embodiment, preferably, the shapes of the first, second and third honeycomb through holes are all regular hexagons. Among them, the aperture of the outermost edge of the first honeycomb through hole is 6 mm, the aperture of the outermost edge of the second honeycomb through hole is 4 mm, and the aperture of the outermost edge of the third honeycomb through hole is 2 mm.

[0056] In this embodiment, the middle outer layer is made of aluminum alloy. Aluminum alloy is typically chosen for its superior stiffness and strength, making it suitable for bearing initial impact or external loads. The middle transition layer is made of a Kevlar / aluminum composite material, which may refer to a Kevlar fiber-reinforced aluminum-based composite material, a composite structure of a Kevlar honeycomb core and aluminum panels, or a Kevlar fabric embedded in an aluminum honeycomb. Combining the advantages of both, it leverages the stiffness of aluminum and the toughness / energy absorption properties of Kevlar to achieve a balanced transition between strength and energy absorption in the transition region. The middle inner layer is made of pure Kevlar. Small-pore honeycombs typically have higher plateau stresses and better energy absorption efficiency when compressed, while Kevlar itself is an excellent energy-absorbing material. This layer is primarily used to dissipate the final impact energy or bear the innermost load. This design aims to achieve optimal energy absorption sequence and efficiency while maintaining the stiffness and lightweight of the overall structure. The specific energy absorption value tested according to ASTM D3763 reached 35 J / g.

[0057] The inner shell 3 is a porous sound absorbing structure, see Figure 6 In this embodiment, the porous sound absorbing structure is preferably made of polyurethane foam or micro-perforated plate. According to the principle of acoustic impedance matching, the porous sound absorbing structure can reduce noise through sound wave reflection and energy dissipation.

[0058] An elastic damping layer is provided on the inner side of the inner shell 3. This elastic damping layer comprises a damping base layer, a damping intermediate layer, and a damping contact layer. The damping base layer is bonded to the inner side of the inner shell, while the damping intermediate layer is positioned between the damping base layer and the damping contact layer. The inner diameter of the damping contact layer is larger than the diameter of the rotor. The damping contact layer can accommodate the rotor and, in contact with the rotor, reduces the transmission of high-frequency vibrations (theoretically based on the principle of mechanical impedance mismatch). In one embodiment, the elastic damping layer is made of rubber or silicone. In this embodiment, the damping base layer is made of silicone (Shore hardness 50A), the damping intermediate layer is made of copper mesh (120 mesh), and the damping contact layer is made of fluororubber. Preferably, the damping base layer is 2 mm thick, the damping intermediate layer is 0.5 mm thick, and the damping contact layer is 0.3 mm thick. The elastic damping layer is laminated to the inner side of the porous sound-absorbing structure by hot pressing, with a pre-compression of 15%.

[0059] Pressure sensors are installed between the outer shell 1 and the intermediate layer 2 to detect the spacing between the mounting enclosure and the rotor. When the spacing falls below a preset threshold, an alarm is triggered. These thresholds include a warning value and a danger value. When the spacing falls below the warning value, a first alarm is triggered; when the spacing falls below the danger value, a second alarm is triggered, and the machine automatically shuts down. In this embodiment, six pressure sensors are equidistantly spaced circumferentially between the outer shell 1 and the intermediate layer 2. Preferably, the pressure sensors are MEMS piezoresistive sensors with a range of 0-50 kPa and a sampling frequency of 1 kHz. Preferably, the warning value is 3 mm, with a yellow alarm as the first alarm signal, and a red alarm as the second alarm signal when the danger value is 1.5 mm.

[0060] In one or more embodiments, the low-altitude manned aircraft rotor installation housing box device is composed of multiple arc-shaped units 5, see Figure 8 . In this embodiment, the arc unit adopts a 60° standard arc segment. The outer shell 1 is spliced ​​by multiple arc-shaped outer shell units, the middle layer 2 is spliced ​​by multiple arc-shaped middle layer units, the inner shell 3 is spliced ​​by multiple arc-shaped inner shell units, the outer shell base 4 is spliced ​​by multiple arc-shaped outer shell base units, and each arc unit 5 includes an arc-shaped outer shell unit, an arc-shaped middle layer unit, an arc-shaped inner shell unit and an arc-shaped outer shell base unit. The number of arc units 5 is adjusted according to the size of the rotor. For example, for a Φ600mm rotor (i.e., a rotor diameter of 600mm), 10 arc units are spliced, and for a Φ800mm rotor, 12 arc units are spliced.

[0061] In this embodiment, multiple arc-shaped units 5 are assembled into a ring structure via a quick-release interface. This interface is a male-female tenon structure, and the quick-release interface is released by magnetic unlocking. Preferably, the male-female tenon has a tolerance of H7 / g6, a clearance fit, enabling tool-free insertion and removal. This quick-release interface achieves a preload force of ≥200N while reducing the release force to ≤50N. A bidirectional wedge-shaped lock allows for assembly and disassembly of the rotor housing in 0.5 seconds.

[0062] In this embodiment, the diameter of the mounting containment box is 10% to 15% larger than the rotor diameter to ensure safety redundancy. Furthermore, the weight of the mounting containment box does not exceed 20% of the total rotor weight to avoid affecting the thrust-to-weight ratio of the low-altitude manned aircraft.

[0063] In the present invention, a method for manufacturing a low-altitude manned aircraft rotor mounting containment box device comprises the following steps:

[0064] S1. Preparation and Structural Formation of the Outer Shell: Selective laser sintering is used, using a carbon fiber-reinforced polyamide matrix as the material. In this example, the material chosen is CF / PA6, a carbon fiber-reinforced nylon 6 composite material with high strength, high stiffness, excellent heat resistance, and dimensional stability. Using a laser power of 80W and a layer thickness of 0.1mm, the streamlined, aerodynamic-shaped carbon fiber outer shell is sintered layer by layer. The surface is coated with a nano-silica coating, and T-shaped guide rails are pre-installed on the inner wall of the outer shell.

[0065] S2, Preparation and Assembly of the Intermediate Layer: Digital Light Processing (DLP) prints a honeycomb mold with a gradient-designed honeycomb aperture. Vacuum-assisted resin infusion injects Kevlar fiber / epoxy resin into the mold, which cures to form a gradient honeycomb-shaped, energy-absorbing structure with through-holes. This achieves the Kevlar composite material portion of the "Kevlar / aluminum composite" described above (although the matrix here is epoxy resin rather than aluminum, the functional positioning is similar). This combines the flexibility and precision of complex molds manufactured using 3D printing (DLP) with the excellent mechanical properties and lightweight characteristics of composite materials (VARI). This avoids the equipment complexity or performance limitations of direct 3D printing of continuous fiber-reinforced composites. Multiple T-shaped protrusions are provided on the outer wall of the intermediate layer, sliding and inserting along the T-shaped guide rails of the outer layer to form a self-locking mechanical interlock.

[0066] S3, Molding and Assembly of the Composite Structure of the Inner Shell and Elastic Damping Layer: The inner shell is constructed from a polyurethane foam foam. The foam can be directly poured / injected into the prefabricated inner cavity of the honeycomb structure, or formed using a separate mold and then assembled. The density of the molded inner shell is 0.3 g / cm³. The main advantages of low-density foam are its excellent energy absorption capacity (absorbing large amounts of energy through cell crushing) and extreme lightweight. The elastic damping layer is hot-pressed onto the inner side of the inner shell. Clips are provided on the outer wall of the inner shell to press the inner shell into the inner side of the middle layer.

[0067] S4, preparation and assembly of the outer shell base: The outer shell base is inserted into the connecting protrusion at the bottom of the outer shell through the connecting slot, and is connected to the aircraft fuselage through a magnetic quick-release connector.

[0068] The interlayer bonding strength of the mounting and containing box device produced by this manufacturing method is ≥15MPa, the production cycle is shortened to 1 / 3 of that of the traditional process, and the scrap rate is less than 5%.

[0069] This invention also undergoes noise reduction and protection performance verification. Acoustic testing: The noise spectrum before and after installation is compared in an anechoic chamber, with an expected noise reduction of ≥5dB(A). Impact testing: A high-speed camera is used to record a rotor fracture scenario to verify debris containment capabilities (referring to SAE ARP4761 safety standards).

[0070] It should be noted that, in the present invention, “inside” refers to a direction close to the center of the installation containing box, and “outside” refers to a direction away from the center of the installation containing box.

[0071] The low-altitude manned aircraft rotor installation housing box device and the manufacturing method thereof of the present invention have the following beneficial effects:

[0072] 1. The device utilizes a gradient honeycomb perforated structure. Three layers of honeycomb perforations with varying apertures progressively attenuate noise, effectively reducing aerodynamic and mechanical noise and enhancing passenger comfort. Furthermore, the elastic damping layer utilizes a combination of silicone, copper mesh, and fluororubber to further absorb vibration energy, reduce noise conduction, and improve operational stability.

[0073] The device's multi-layered structure effectively absorbs and disperses the kinetic energy of rotor fragments, reducing the risk of secondary damage. An outer layer of carbon fiber-reinforced polyamide matrix and silica coating provides high-strength protection, while an intermediate layer of aluminum alloy, Kevlar / aluminum composite, and pure Kevlar achieves gradient energy absorption. An inner layer of polyurethane foam or micro-perforated sheeting further cushions the energy.

[0074] 3. The device adopts a modular design, consisting of multiple curved units connected via quick-release interfaces. This allows for adjustment to the rotor size, ensuring high adaptability. The magnetic quick-release connector at the base of the outer shell and the male and female tenon structures on the curved units enable rapid installation and removal, significantly improving maintenance efficiency and reducing costs. Furthermore, a pressure sensor monitors the clearance in real time to ensure safe operation.

[0075] The above embodiments are merely further explanations of the present invention and are not intended to limit the present invention in any other manner. The present invention may also have various other embodiments. Those skilled in the art may make various corresponding modifications and variations based on the present invention without departing from the spirit and substance of the present invention, and such corresponding modifications and variations shall fall within the scope of protection of the present invention.

Claims

1. A low-altitude manned aircraft rotor installation containment box device, characterized in that: include: An outer shell, wherein the outer wall of the outer shell is a streamlined aerodynamic shape, a plurality of T-shaped guide rails are provided on the inner wall of the outer shell, and a plurality of connecting protrusions are provided on the bottom of the outer shell; An intermediate layer, wherein a plurality of T-shaped protrusions are provided on the outer wall of the intermediate layer, the T-shaped protrusions match the T-shaped guide rail, the intermediate layer is slidably embedded in the T-shaped guide rail through the T-shaped protrusions, a plurality of gradient honeycomb through holes are provided on the intermediate layer, the intermediate layer comprises an intermediate outer layer, an intermediate transition layer and an intermediate inner layer, the intermediate transition layer is provided between the intermediate outer layer and the intermediate inner layer, the T-shaped protrusions are provided on the outer wall of the intermediate outer layer, a plurality of first honeycomb through holes are provided on the intermediate outer layer, a plurality of second honeycomb through holes are provided on the intermediate transition layer, a plurality of third honeycomb through holes are provided on the intermediate inner layer, the aperture of the first honeycomb through hole is larger than the aperture of the second honeycomb through hole, the aperture of the second honeycomb through hole is larger than the aperture of the third honeycomb through hole, each first honeycomb through hole corresponds to a second honeycomb through hole and a third honeycomb through hole respectively to form a plurality of gradient honeycomb through holes; An inner shell, wherein a plurality of buckles are provided on the outer wall of the inner shell, and the inner shell is pressed into the inner side of the middle layer through the buckles. The inner shell is used to accommodate the rotor, and the inner diameter of the inner shell is larger than the diameter of the rotor. The inner shell is provided with a plurality of circular through holes; The outer shell base is provided with a plurality of connecting slots, the connecting slots match the connecting protrusions, the outer shell base is connected to the outer shell through the connecting slots, and the bottom of the outer shell base is provided with a magnetic quick-release connector, and the outer shell base is connected to the aircraft fuselage through the magnetic quick-release connector.

2. The low-altitude manned aircraft rotor installation and containing box device according to claim 1, characterized in that: An elastic damping layer is arranged on the inner side of the inner shell, and the elastic damping layer includes a damping base layer, a damping intermediate layer and a damping contact layer. The damping base layer is adhered to the inner side of the inner shell, and the damping intermediate layer is arranged between the damping base layer and the damping contact layer. The inner diameter of the damping contact layer is larger than the diameter of the rotor.

3. The low-altitude manned aircraft rotor installation housing box device according to claim 2, characterized in that: The damping matrix layer is made of silica gel, the damping intermediate layer is made of copper mesh, and the damping contact layer is made of fluororubber.

4. The low-altitude manned aircraft rotor installation and containing box device according to claim 1, characterized in that: A pressure sensor is installed between the outer shell and the middle layer to detect the distance between the installation box and the rotor. When the distance value is less than a preset distance threshold, an alarm is triggered. The distance threshold includes a warning value and a danger value. When the distance value is less than the warning value, a first alarm signal is triggered. When the distance value is less than the danger value, a second alarm signal is triggered and the machine automatically shuts down.

5. The low-altitude manned aircraft rotor installation and containing box device according to claim 1, characterized in that: The gradient honeycomb-shaped through holes have a radial gradient of 0.5 mm / mm and an axial gradient of 0.3 mm / mm, wherein the radial direction is along the thickness direction and the axial direction is perpendicular to the thickness direction.

6. The low-altitude manned aircraft rotor installation and containing box device according to claim 1, characterized in that: The low-altitude manned aircraft rotor mounting and containing box device is composed of multiple arc-shaped units, the number of which is adjusted according to the size of the rotor, the outer shell is composed of multiple arc-shaped outer shell units, the middle layer is composed of multiple arc-shaped middle layer units, the inner shell is composed of multiple arc-shaped inner shell units, and the outer shell base is composed of multiple arc-shaped outer shell base units, each arc unit includes an arc-shaped outer shell unit, an arc-shaped middle layer unit, an arc-shaped inner shell unit and an arc-shaped outer shell base unit.

7. The low-altitude manned aircraft rotor installation and containing box device according to claim 6, characterized in that: The multiple arc-shaped units are spliced ​​together through a quick-release interface, the quick-release interface is a male-female tenon structure, and the quick-release interface is separated by magnetic unlocking.

8. The low-altitude manned aircraft rotor installation and containing box device according to claim 1, characterized in that: The low-altitude manned aircraft rotor installation containment box device has one or both of the following features: The diameter of the mounting enclosure is 10% to 15% greater than the rotor diameter; The weight of the mounting enclosure does not exceed 20% of the total weight of the rotor.

9. The low-altitude manned aircraft rotor installation and containing box device according to claim 1, characterized in that: The low-altitude manned aircraft rotor installation containment box device has one or more of the following features: The outer shell is made of a carbon fiber reinforced polyamide matrix, and the outer wall of the outer shell is covered with a silicon dioxide coating; In the intermediate layer, the material of the intermediate outer layer is aluminum alloy, the material of the intermediate transition layer is Kevlar / aluminum composite material, and the material of the intermediate inner layer is pure Kevlar; The material of the inner shell is polyurethane foam or micro-perforated plate.

10. A method for manufacturing a low-altitude manned aircraft rotor installation containing box device, applied to the low-altitude manned aircraft rotor installation containing box device according to any one of claims 1 to 9, characterized in that: The steps include: S1, Preparation and Structural Forming of the Outer Shell: Selective laser sintering is used with a carbon fiber reinforced polyamide matrix as the material. The laser power is 80W and the layer thickness is 0.1mm. The streamlined aerodynamic carbon fiber outer shell is sintered layer by layer. The surface is coated with nano-silica. T-shaped guide rails are pre-installed on the inner wall of the outer shell. S2, preparation and assembly of the middle layer: Digital light processing (DLP) prints a honeycomb mold with a gradient honeycomb aperture design. Vacuum-assisted resin infusion is used to inject Kevlar fiber / epoxy resin into the mold. After curing, gradient honeycomb-shaped through-holes are formed. Multiple T-shaped protrusions are set on the outer wall of the middle layer. The T-shaped protrusions slide and embed along T-shaped guide rails to form a self-locking mechanical interlock. S3, forming and assembling the composite structure of the inner shell and the elastic damping layer: forming the inner shell by foaming a polyurethane foam, and hot-pressing the composite elastic damping layer on the inner side of the inner shell. A buckle is provided on the outer wall of the inner shell, and the inner shell is pressed into the inner side of the intermediate layer by the buckle; S4, preparation and assembly of the outer shell base: The outer shell base is inserted into the connecting protrusion at the bottom of the outer shell through the connecting slot, and is connected to the aircraft fuselage through a magnetic quick-release connector.

Images