Rotor wing installation containing box device of low-altitude manned aircraft and manufacturing method of rotor wing installation containing box device

Abstract

According to the low-altitude manned aircraft rotor wing installation containing box device and the manufacturing method thereof, through the synergistic effect of the outer shell, the middle layer, the inner shell and the outer shell base, the aerodynamic noise is reduced, the fragment collision kinetic energy attenuation rate is increased, meanwhile, high-frequency vibration transmission is restrained, and the rotor wing installation containing box device is suitable for being used for low-altitude manned aircrafts. The operation stability of the aircraft and the comfort of passengers are improved. A magnetic suction quick-release connector is arranged on the outer-layer shell base, and the outer-layer shell base is connected with the aircraft fuselage through the magnetic suction quick-release connector. The outer wall of the outer-layer shell is in a streamline aerodynamic shape, and a T-shaped guide rail is arranged on the inner wall of the outer-layer shell. The outer wall of the middle layer is provided with a plurality of T-shaped protrusions, the T-shaped protrusions are matched with the T-shaped guide rails, the middle layer is embedded into the T-shaped guide rails of the outer-layer shell in a sliding mode through the T-shaped protrusions, the outer wall of the inner-layer shell is provided with a plurality of buckles, the buckles are buckled into the inner side of the middle layer to achieve connection between the inner-layer shell and the middle layer, and the inner-layer shell is used for containing a rotor wing.

Description

Technical Field

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

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

[0003] However, the following key problems still need to be solved urgently in the prior art: 1) Aerodynamic and mechanical noise problems: When the rotor of a traditional low-altitude manned aircraft operates, broadband aerodynamic noise is generated due to the intense friction between the high-speed rotation and the air. At the same time, mechanical vibrations are transmitted to the fuselage through the rigid structure, forming superimposed noise, which seriously affects the comfort of passengers and the stability of equipment. 2) Risk of secondary damage from rotor fracture fragments: The rotor may fracture under extreme conditions (such as foreign object impact, fatigue fracture), and the fragments fly at high speed. Their kinetic energy is transmitted to the fuselage through the rigid connection structure, causing secondary damage. Most existing protection schemes 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 insufficient attenuation rate of fragment kinetic energy and difficult maintenance of the integral structure, with high maintenance costs.

[0004] Traditional casings are mostly integrally cast or fiber-wound, which cannot be adapted to rotors of different sizes and lack a modular quick-disassembly design, resulting in low maintenance efficiency. For example, in Chinese Patent CN114643725B, although a manufacturing method of a composite material casing is proposed, it does not integrate the collaborative design of noise reduction and impact resistance, making it difficult to balance aerodynamic noise and fragment protection performance.

[0005] Therefore, it is urgent to develop a new type of rotor installation containment box device for a low-altitude manned aircraft 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 improve the safety protection ability of rotor fracture fragments.

[0007] To achieve the above purpose, the present invention provides a rotor installation containment box device for a low-altitude manned aircraft, including: An outer shell, the outer wall of the outer shell has 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 at the bottom of the outer shell; The middle layer, on the outer wall of which there are provided a plurality of T-shaped protrusions that match with the T-shaped guide rails. The middle layer is slidably inserted into the T-shaped guide rails through the T-shaped protrusions. There are provided a plurality of gradient honeycomb-shaped through holes on the middle layer. The middle layer includes an outer middle layer, a middle transition layer and an inner middle layer. The middle transition layer is arranged between the outer middle layer and the inner middle layer. The T-shaped protrusions are arranged on the outer wall of the outer middle layer. There are provided a plurality of first honeycomb-shaped through holes on the outer middle layer, a plurality of second honeycomb-shaped through holes on the middle transition layer, and a plurality of third honeycomb-shaped through holes on the inner middle layer. 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 respectively to form a plurality of gradient honeycomb-shaped through holes; The inner layer housing, on the outer wall of which there are provided a plurality of buckles. The inner layer housing is pressed into the inside of the middle layer through the buckles. The inner layer housing is used for accommodating the rotor. The inner diameter of the inner layer housing is larger than the diameter of the rotor. There are provided a plurality of circular through holes on the inner layer housing; The outer layer housing base, on which there are provided a plurality of connection card slots that match with the connection protrusions. The outer layer housing base is connected to the outer layer housing through the connection card slots. A magnetic quick-release joint is arranged at the bottom of the outer layer housing base. The outer layer housing base is connected to the aircraft fuselage through the magnetic quick-release joint.

[0008] In one embodiment, an elastic damping layer is arranged inside the inner layer housing. The elastic damping layer includes a damping matrix layer, a damping middle layer and a damping contact layer. The damping matrix layer is attached to the inner side of the inner layer housing. The damping middle layer is arranged between the damping matrix layer and the damping contact layer. The inner diameter of the damping contact layer is larger than the diameter of the rotor.

[0009] In one embodiment, the damping matrix layer is made of silica gel, the damping middle layer is made of copper mesh, and the damping contact layer is made of fluororubber.

[0010] In one embodiment, a pressure sensor is installed between the outer layer housing and the middle layer for detecting the spacing value between the installation containment box and the rotor. When the spacing value is less than the preset spacing threshold, an alarm is triggered. The spacing threshold includes a warning value and a danger value. When the spacing value is less than the warning value, a first alarm signal is triggered. When the spacing value is less than the danger value, a second alarm signal is triggered and the machine stops automatically.

[0011] In one embodiment, the radial gradient of the gradient honeycomb-shaped through hole is 0.5 mm / mm, and the axial gradient is 0.3 mm / mm. Wherein, the radial direction is along the thickness direction, and the axial direction is perpendicular to the thickness direction.

[0012] In one embodiment, the rotor installation containment box device of the low-altitude manned aircraft is formed by splicing a plurality of arc units. The number of the arc units is adjusted according to the rotor size. The outer shell is formed by splicing a plurality of arc-shaped outer shell units. The intermediate layer is formed by splicing a plurality of arc-shaped intermediate layer units. The inner shell is formed by splicing a plurality of arc-shaped inner shell units. The outer shell base is formed by splicing a plurality of arc-shaped outer shell base units. Each arc unit includes an arc-shaped outer shell unit, an arc-shaped intermediate layer unit, an arc-shaped inner shell unit and an arc-shaped outer shell base unit.

[0013] In one embodiment, the plurality of arc units are spliced through quick-release interfaces. The quick-release interfaces are male and female tenon structures, and the separation method of the quick-release interfaces is magnetic unlocking.

[0014] In one embodiment, the rotor installation containment box device of the low-altitude manned aircraft has one or both of the following characteristics: The diameter of the installation containment box is greater than 10% - 15% of the rotor diameter; The weight of the installation containment box does not exceed 20% of the total weight of the rotor.

[0015] In one embodiment, the rotor installation containment box device of the low-altitude manned aircraft has one or more of the following characteristics: The outer shell is prepared from a carbon fiber reinforced polyamide matrix, and a silica coating is covered on the outer wall of the outer shell; 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 a micro-perforated plate.

[0016] To achieve the above object, the present invention also provides a manufacturing method for a rotor installation containment box device of a low-altitude manned aircraft, which is applied to the rotor installation containment box device of the low-altitude manned aircraft as described above. The manufacturing method includes the following steps: S1, Preparation and structural shaping of the outer shell: Selective laser sintering is used. With a carbon fiber reinforced polyamide matrix as the material, a laser power of 80W and a layer thickness of 0.1mm are used to sinter layer by layer to form a streamline aerodynamic profile carbon fiber outer shell, and a nano-silica coating is covered on the surface. T-shaped guide rails are pre-set 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.

[0017] The low-altitude manned aircraft rotor installation housing box device and the manufacturing method thereof of the present invention have the following beneficial effects: 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.

[0018] 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.

[0019] 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

[0020] Figure 1 An 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; 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; 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; Figure 4Front view schematic diagram of the outer shell base of the rotor installation containment box device of a low-altitude manned aircraft according to an embodiment of the present invention; Figure 5 Structural schematic diagram of the intermediate layer of the rotor installation containment box device of a low-altitude manned aircraft according to an embodiment of the present invention, where (a) is its three-dimensional schematic diagram, (b) is its top view schematic diagram, (c) is its side view schematic diagram, (d) is the enlarged schematic diagram at A1 in (b), and (e) is the enlarged schematic diagram at A2 in (c); Figure 6 Structural schematic diagram of the inner shell of the rotor installation containment box device of a low-altitude manned aircraft according to an embodiment of the present invention, where (a) is its three-dimensional schematic diagram, (b) is its top view schematic diagram, (c) is its side view schematic diagram, and (d) is the enlarged schematic diagram at B in (c); Figure 7 Structural schematic diagram of the outer shell of the rotor installation containment box device of a low-altitude manned aircraft according to an embodiment of the present invention, where (a) is its top view schematic diagram, (b) is its three-dimensional schematic diagram, and (c) is its side view schematic diagram; Figure 8 Structural schematic diagram of the arc unit of the rotor installation containment box device of a low-altitude manned aircraft according to an embodiment of the present invention. Reference numerals

[0021] 1 - Outer shell, 2 - Intermediate 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-shaped through hole, 31 - Snap, 32 - Circular through hole, 41 - Connecting card slot, 42 - Magnetic quick-release joint. Detailed implementation manners

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, 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 used to limit the invention.

[0023] As Figure 1 and Figure 2 shown, the present invention proposes a rotor installation containment box device for a low-altitude manned aircraft, including: an outer shell 1, an intermediate layer 2, an inner shell 3, and an outer shell base 4. The installation containment box device is integrally annular. As Figure 2 and Figure 7 shown, the outer wall of the outer shell 1 has 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 at the bottom of the outer shell 1.

[0024] As Figure 1 and Figure 5As shown, a plurality of T-shaped protrusions 21 are provided on the outer wall of the middle layer 2. The T-shaped protrusions 21 are matched with the T-shaped guide rails 11. The middle layer 2 is slidably inserted into the T-shaped guide rails 11 of the outer shell through the T-shaped protrusions 21. The T-shaped protrusions 21 and the T-shaped guide rails 11 form a self-locking mechanical interlock. At this time, the outer wall of the middle layer 2 is in contact with the inner wall of the outer shell 1. A plurality of gradient honeycomb-shaped through holes 22 are provided on the middle layer 2. The middle layer 2 includes an outer middle layer, a middle transition layer, and an inner middle layer. The middle 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. A plurality of first honeycomb-shaped through holes are provided on the outer middle layer. A plurality of second honeycomb-shaped through holes are provided on the middle transition layer. A plurality of third honeycomb-shaped through holes are provided on the inner middle layer. The aperture of the first honeycomb-shaped through hole is larger than the aperture of the second honeycomb-shaped through hole. The aperture of the second honeycomb-shaped through hole is larger than the aperture 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 respectively to form a plurality of gradient honeycomb-shaped through holes 22. See Figure 5 .

[0025] A plurality of buckles 31 are provided on the outer wall of the inner shell 3. The inner shell 3 is pressed into the inner side of the middle layer 2 through the buckles 31 to realize the connection between the inner shell 3 and the middle layer 2. The outer side of the inner shell 3 is in contact with 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. A plurality of circular through holes 32 are provided on the inner shell 3. See Figure 6 .

[0026] As Figure 1 and Figure 3 shown, a plurality of connection slots 41 are provided on the outer shell base 4. The connection slots 41 are matched with the connection protrusions 12. The outer shell base 4 is connected to the outer shell 1 through the connection slots 41. As Figure 4 shown, a magnetic quick-release joint 42 is provided at the bottom of the outer shell base 4. The outer shell base 4 is connected to the aircraft fuselage through the magnetic quick-release joint 42. In this embodiment, the outer shell base 4 is connected to the engine of the aircraft through the magnetic quick-release joint 42.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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 .

[0032] 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%.

[0033] 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.

[0034] In this embodiment, the material of the middle outer layer is aluminum alloy. Aluminum alloy is usually selected because it has good stiffness and strength and is suitable for being the part that bears the initial impact or external load. The material of the middle transition layer is Kevlar / aluminum composite material, which may refer to Kevlar fiber-reinforced aluminum matrix composite material, or a certain composite structure of Kevlar honeycomb core and aluminum panel, or Kevlar fabric embedded in aluminum honeycomb. The advantage of combining the two lies in utilizing the stiffness of aluminum and the toughness / energy absorption characteristics of Kevlar to achieve a balanced transition of strength and energy absorption in the transition region. The material of the middle inner layer is pure Kevlar. Small-aperture honeycombs usually have higher plateau stress and better energy absorption efficiency when compressed, and Kevlar itself is an excellent energy-absorbing material. This layer is mainly used to dissipate the final impact energy or bear the innermost load. This design aims to achieve the optimal energy absorption sequence and efficiency while maintaining the stiffness and light weight of the overall structure. The specific energy absorption value tested according to ASTM D3763 standard reaches 35 J / g.

[0035] The inner shell 3 is a porous sound-absorbing structure. Refer to Figure 6 . In this embodiment, preferably, the material of the porous sound-absorbing structure is polyurethane foam or micro-perforated plate. According to the principle of acoustic impedance matching, it can be known that this porous sound-absorbing structure can reduce noise through sound wave reflection and energy dissipation.

[0036] An elastic damping layer is arranged on the inner side of the inner shell 3. The elastic damping layer includes a damping matrix layer, a damping intermediate layer and a damping contact layer. The damping matrix layer is attached to the inner side of the inner shell. The damping intermediate layer is arranged between the damping matrix layer and the damping contact layer. The inner diameter of the damping contact layer is larger than the diameter of the rotor. The rotor can be accommodated in the damping contact layer. The damping contact layer contacts the rotor and can reduce the transmission of high-frequency vibration (theoretical basis: the principle of mechanical impedance mismatch). In one embodiment, the material of the elastic damping layer is rubber or silica gel. In this embodiment, the material of the damping matrix layer is selected as silica gel (Shore hardness 50A), the material of the damping intermediate layer is selected as copper mesh (120 mesh), and the material of the damping contact layer is selected as fluororubber. Preferably, the thickness of the damping matrix layer is 2 mm, the thickness of the damping intermediate layer is 0.5 mm, and the thickness of the damping contact layer is 0.3 mm. This elastic damping layer is thermally pressed and compounded to the inner side of the porous sound-absorbing structure with a pre-compression amount of 15%.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] In this embodiment, the diameter of the mounting enclosure is 10% to 15% greater than the rotor diameter to ensure safety redundancy. Furthermore, the weight of the mounting enclosure does not exceed 20% of the total rotor weight to avoid affecting the thrust-to-weight ratio of the low-altitude manned aircraft.

[0041] In the present invention, a method for manufacturing a low-altitude manned aircraft rotor mounting containment box device comprises the following steps: 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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%.

[0046] 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).

[0047] It should be noted that in the present invention, "inner" refers to the direction close to the center of the installation containment box, and "outer" refers to the direction away from the center of the installation containment box.

[0048] The rotor installation containment box device and its manufacturing method of the low-altitude manned aircraft of the present invention have the following beneficial effects: 1. The device adopts a gradient honeycomb-shaped through-hole structure, and attenuates noise step by step through three layers of honeycomb-shaped through-holes with different pore diameters, effectively reducing aerodynamic and mechanical noises and improving the comfort of passengers. At the same time, the elastic damping layer adopts a combination of silica gel, copper mesh and fluororubber to further absorb vibration energy, reduce noise conduction and improve the operation stability of the equipment.

[0049] 2. The multi-layer structure design of the device can effectively absorb and disperse the kinetic energy of the broken rotor fragments, reducing the risk of secondary damage. The outer carbon fiber reinforced polyamide matrix and silica coating provide high-strength protection, the intermediate layer of aluminum alloy, Kevlar / aluminum composite material and pure Kevlar achieve gradient energy absorption, and the inner layer of polyurethane foam or micro-perforated plate further buffers the energy.

[0050] 3. The device adopts a modular design and is spliced by multiple arc units through quick-release interfaces, which can be adjusted according to the rotor size and has strong adaptability. In the present invention, the magnetic quick-release joint at the base of the outer shell and the male-female tenon structure on the arc unit achieve quick installation and disassembly, significantly improving the maintenance efficiency and reducing the maintenance cost. In addition, the pressure sensor monitors the distance in real time to ensure safe operation.

[0051] The above embodiments are only further descriptions of the present invention, rather than other forms of limitations on the present invention. The present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding modifications and changes according to the present invention, but these corresponding modifications and changes should all fall within the protection scope of the present invention.

Claims

1. A rotor installation containment box device for a low-altitude manned aircraft, characterized in that, Comprising: An outer shell, the outer wall of the outer shell has 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 at the bottom of the outer shell; An intermediate layer, a plurality of T-shaped protrusions are provided on the outer wall of the intermediate layer, the T-shaped protrusions are matched with the T-shaped guide rails, the intermediate layer is slidably embedded in the T-shaped guide rails through the T-shaped protrusions, and a plurality of gradient honeycomb-shaped through holes are provided on the intermediate layer. The intermediate layer includes 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-shaped through holes are provided on the intermediate outer layer, a plurality of second honeycomb-shaped through holes are provided on the intermediate transition layer, and a plurality of third honeycomb-shaped through holes are provided on the intermediate inner layer. The aperture of the first honeycomb-shaped through hole is larger than the aperture of the second honeycomb-shaped through hole, and the aperture of the second honeycomb-shaped through hole is larger than the aperture 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 respectively to form a plurality of gradient honeycomb-shaped through holes; An inner shell, a plurality of buckles are provided on the outer wall of the inner shell, the inner shell is pressed into the inside of the intermediate layer through the buckles, the inner shell is used to accommodate the rotor, the inner diameter of the inner shell is larger than the diameter of the rotor, and a plurality of circular through holes are provided on the inner shell; An outer shell base, a plurality of connecting slots are provided on the outer shell base, the connecting slots are matched with the connecting protrusions, the outer shell base is connected to the outer shell through the connecting slots, a magnetic quick-release joint is provided at the bottom of the outer shell base, and the outer shell base passes through the magnetic quick-release joint is connected to the aircraft fuselage.

2. The rotor installation containment box device of the low-altitude manned aircraft according to claim 1, characterized in that, An elastic damping layer is provided inside the inner shell. The elastic damping layer includes a damping matrix layer, a damping intermediate layer and a damping contact layer. The damping matrix layer is attached to the inner side of the inner shell. The damping intermediate layer is provided between the damping matrix layer and the damping contact layer. The inner diameter of the damping contact layer is larger than the diameter of the rotor.

3. The rotor installation containment box device of the low-altitude manned aircraft according to claim 2, characterized in that The damping matrix layer is made of silicone rubber, 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 containment box device according to claim 1, characterized in that, A pressure sensor is installed between the outer shell and the intermediate layer to detect the spacing value between the installation containment box and the rotor. When the spacing value is less than the preset spacing threshold, an alarm is triggered. The spacing threshold includes a warning value and a danger value. When the spacing value is less than the warning value, a first alarm signal is triggered. When the spacing value is less than the danger value, a second alarm signal is triggered and the machine stops automatically.

5. The rotor installation containment box device of the low-altitude manned aircraft according to claim 1, characterized in that, The radial gradient of the gradient honeycomb-shaped through hole is 0.5 mm / mm, and the axial gradient is 0.3 mm / mm. Among them, 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 containment 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 rotor installation containment box device of the low-altitude manned aircraft 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 containment 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 rotor installation containment box device of the low-altitude manned aircraft 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 manufacturing method of a rotor installation containment box device for a low-altitude manned aircraft, applied to the rotor installation containment box device for a low-altitude manned aircraft 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