Unmanned aerial vehicle convenient for noise reduction and sound absorption

Abstract

The utility model belongs to the technical field of aircrafts, and particularly relates to an unmanned aerial vehicle convenient for noise reduction and sound absorption, which comprises an unmanned aerial vehicle main body, a rotary mounting seat arranged on the side surface of the unmanned aerial vehicle main body, a damping bearing seat arranged at the bottom of the rotary mounting seat, a hollow arm rotatably mounted at the bottom of the damping bearing seat, and a supporting seat mounted at one end of the hollow arm. Foam mounting grooves are formed in the inner sides of the hollow machine arms, gradient density polyurethane foam is mounted on the inner sides of the foam mounting grooves, perforated aluminum plates are mounted at the positions, located at notches of the foam mounting grooves, of the tops of the hollow machine arms in a threaded connection mode, motor mounting bins are mounted at the tops of the supporting seats, and sandwich type damping structures are mounted on the inner sides of the motor mounting bins. According to the device, low-noise hardware is adopted to reduce the operation noise of the unmanned aerial vehicle, and meanwhile, the operation noise of the unmanned aerial vehicle is further reduced through the design of a noise reduction and sound absorption structure.

Description

Technical Field

[0001] This utility model belongs to the field of aircraft technology, specifically relating to an unmanned aerial vehicle that facilitates noise reduction and sound absorption. Background Technology

[0002] Unmanned aerial vehicles, or UAVs for short, are unmanned aircraft controlled by radio remote control equipment and onboard program control devices, or operated autonomously by an onboard computer, either completely or intermittently. Ordinary quadcopter drones, due to their generally low flight altitude, easily transmit noise to the ground. Although some drones now use low-noise motors and propellers, aerodynamic noise generated by motor resonance, arm resonance, and propeller rotation still exists during drone operation, failing to meet the low-noise requirements of some operating environments. To improve this problem, we propose an unmanned aerial vehicle that is easy to reduce noise and absorb sound. Utility Model Content

[0003] To address the above problems, the purpose of this utility model is to provide an unmanned aerial vehicle (UAV) that facilitates noise reduction and sound absorption. While using low-noise hardware to reduce the operating noise of the UAV, further noise reduction and sound absorption structure design is used to further reduce the operating noise of the UAV.

[0004] To achieve the above objectives, this utility model provides the following technical solution: an unmanned aerial vehicle (UAV) that facilitates noise reduction and sound absorption, comprising a UAV body, a rotating mounting base on the side of the UAV body, a damping bearing seat at the bottom of the rotating mounting base, a hollow arm rotatably mounted at the bottom of the damping bearing seat, a support seat mounted at one end of the hollow arm, a foam mounting groove on the inner side of the hollow arm, gradient density polyurethane foam mounted inside the foam mounting groove, a perforated aluminum plate screwed onto the top of the hollow arm at the opening of the foam mounting groove, a motor mounting compartment mounted on the top of the support seat, a sandwich-type shock absorption structure mounted inside the motor mounting compartment, the sandwich-type shock absorption structure comprising a lower silicone layer, a honeycomb aluminum plate on top of the lower silicone layer, an upper silicone layer on top of the honeycomb aluminum plate, a noise-reducing motor on top of the upper silicone layer, a top cover on top of the motor mounting compartment, and the output end of the noise-reducing motor penetrating through the top cover and connected to a low-noise propeller.

[0005] The beneficial effects of this invention are as follows: During drone operation, the noise-reducing motor and low-noise propellers work together to reduce operating noise. Simultaneously, the sandwich-style vibration damping structure further efficiently absorbs and isolates the energy generated by high-frequency vibrations during motor operation. The "soft-hard-soft" layered design, consisting of a lower silicone layer, a honeycomb aluminum plate, and an upper silicone layer, suppresses vibration transmission while maintaining structural rigidity. This further reduces the operating noise of the noise-reducing motor, building upon its already low-noise performance. During drone operation, low-frequency structural noise is transmitted through the arms, while the rotation of the propellers generates mid-to-high frequency aerodynamic noise. This device further reduces noise from these two components through gradient sound absorption of gradient-density polyurethane foam and resonant sound attenuation of perforated aluminum plates. Through these technical means, while using low-noise hardware to reduce drone operating noise, the design of further noise-reducing and sound-absorbing structures further reduces the overall operating noise of the drone.

[0006] For support when this device is parked:

[0007] As a further improvement to the above technical solution: the bottom of the support base is equipped with feet.

[0008] The beneficial effect of this improvement is that the feet are used to support the device when it is parked.

[0009] To absorb the operating noise of the noise-reducing motor:

[0010] As a further improvement to the above technical solution, the inner side of the motor mounting compartment is also provided with sound-absorbing sponge.

[0011] The beneficial effect of this improvement is that the sound-absorbing sponge can be used to further absorb and reduce the operating noise of the motor.

[0012] To eliminate the resonance noise generated by the vibration of the machine arm:

[0013] As a further improvement to the above technical solution: the density of the gradient density polyurethane foam gradually increases from the end near the main body of the drone to the end near the support base, in the order of low density foam, medium density foam, and high density foam.

[0014] The beneficial effects of this improvement are as follows: the density of the gradient density polyurethane foam gradually increases from the end near the main body of the drone to the end near the support base, gradually increasing from low-density foam to high-density foam. The high-density foam with high rigidity in the gradient density polyurethane foam directly resists the structural vibration transmitted by the arm. Its closed-cell structure converts vibration energy into heat energy through viscous friction. Meanwhile, the medium-density foam located in the middle section of the gradient density polyurethane foam causes multiple reflections of sound waves through the interconnected pores, consuming sound wave energy. The low-density foam near the main body of the drone eliminates residual vibrations to match the vibration wave attenuation law.

[0015] To meet the structural requirements for sound absorption:

[0016] As a further improvement to the above technical solution: there is a 5mm gap between the bottom of the perforated aluminum plate and the gradient density polyurethane foam.

[0017] The beneficial effects of this improvement are: there is a 5mm gap between the bottom of the perforated aluminum plate and the gradient density polyurethane foam, and the perforated aluminum plate and the air layer located between it and the gradient density polyurethane foam cooperate to form a resonant cavity to meet the structure required for sound absorption.

[0018] To slow down the aging of the upper and lower silicone layers:

[0019] As a further improvement to the above technical solution: the surfaces of the lower silicone layer and the upper silicone layer are provided with uniformly arranged circular grooves.

[0020] The beneficial effects of this improvement are: the surfaces of the upper and lower silicone layers are provided with evenly distributed circular grooves, which increases the space for deformation of the upper and lower silicone layers and slows down the aging rate of the material.

[0021] To ensure proper mounting between the noise-reducing motor and the sandwich-style vibration damping structure:

[0022] As a further improvement to the above technical solution: a screw hole is provided through the top and bottom of the lower silicone layer, the honeycomb aluminum plate, and the upper silicone layer, and the noise reduction motor is fixed to the sandwich-type shock absorption structure by bolt connection screw hole.

[0023] The parts of the device not covered herein are the same as or can be implemented using existing technologies. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the isometric structure of this utility model;

[0025] Figure 2 This is a cross-sectional schematic diagram of the hollow arm and motor mounting compartment in this utility model;

[0026] Figure 3 This is a cross-sectional view of the motor mounting compartment in this utility model;

[0027] Figure 4 This is an exploded view of the sandwich-type shock absorption structure in this utility model;

[0028] In the diagram: 1. Drone body; 2. Rotary mounting base; 3. Damping bearing housing; 4. Hollow arm; 5. Support base; 6. Foot; 7. Gradient density polyurethane foam; 8. Perforated aluminum plate; 9. Motor mounting compartment; 10. Sandwich-style shock absorption structure; 11. Lower silicone layer; 12. Honeycomb aluminum plate; 13. Upper silicone layer; 14. Screw hole; 15. Noise-reducing motor; 16. Top cover; 17. Low-noise propellers; 18. Sound-absorbing sponge. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0030] like Figure 1-4 As shown, an unmanned aerial vehicle (UAV) designed for noise reduction and sound absorption includes a UAV body 1. A rotating mounting base 2 is provided on the side of the UAV body 1. A damping bearing seat 3 is provided at the bottom of the rotating mounting base 2. A hollow arm 4 is rotatably mounted on the bottom of the damping bearing seat 3. A support base 5 is mounted at one end of the hollow arm 4. A foam mounting groove is provided on the inner side of the hollow arm 4. Gradient density polyurethane foam 7 is installed inside the foam mounting groove. A perforated aluminum alloy is screwed onto the top of the hollow arm 4 at the opening of the foam mounting groove. Plate 8, the top of the support base 5 is equipped with a motor mounting compartment 9, the inner side of the motor mounting compartment 9 is equipped with a sandwich-type shock absorption structure 10, the sandwich-type shock absorption structure 10 includes a lower silicone layer 11, the top of the lower silicone layer 11 is provided with a honeycomb aluminum plate 12, the top of the honeycomb aluminum plate 12 is provided with an upper silicone layer 13, the top of the upper silicone layer 13 is provided with a noise reduction motor 15, the top of the motor mounting compartment 9 is provided with a top cover 16, the output end of the noise reduction motor 15 passes through the top cover 16 and is connected to the low noise blade 17.

[0031] During drone operation, the noise-reducing motor 15 and low-noise propellers 17 work together to reduce operating noise. Meanwhile, the sandwich-style vibration damping structure 10 further efficiently absorbs and isolates the energy generated by high-frequency vibrations during the operation of the noise-reducing motor 15. The "soft-hard-soft" layered design formed by the lower silicone layer 11, honeycomb aluminum plate 12, and upper silicone layer 13 suppresses vibration transmission while maintaining structural rigidity. This further reduces the operating noise of the noise-reducing motor 15, building upon its already low-noise performance. During drone motor operation, low-frequency structural noise is transmitted through the arms, while the rotation of the propellers generates mid-to-high frequency aerodynamic noise. This device also reduces the noise of these two components through gradient sound absorption of the gradient density polyurethane foam 7 and resonant sound attenuation of the perforated aluminum plate 8. Through these technical means, while using low-noise hardware to reduce drone operating noise, the design of further noise-reducing and sound-absorbing structures further reduces the overall operating noise of the drone.

[0032] The bottom of the support base 5 is equipped with a foot 6.

[0033] The base 6 is used for support when the device is parked.

[0034] The inner side of the motor mounting compartment 9 is also provided with sound-absorbing sponge 18.

[0035] The sound-absorbing sponge 18 is used to further absorb the operating noise of the noise-reducing motor 15.

[0036] The density of the gradient density polyurethane foam 7 gradually increases from the end near the drone body 1 to the end near the support 5, in the order of low density foam, medium density foam, and high density foam.

[0037] The density of the gradient density polyurethane foam 7 gradually increases from one end near the main body 1 of the drone to the other end near the support base 5, gradually increasing from low-density foam to high-density foam. The high-rigidity foam in the gradient density polyurethane foam 7 directly resists the structural vibration transmitted by the arm. Its closed-cell structure converts vibration energy into heat energy through viscous friction. Meanwhile, the medium-density foam in the middle section of the gradient density polyurethane foam 7 causes multiple reflections of sound waves through interconnected pores, consuming sound wave energy. The low-density foam near the main body of the drone eliminates residual vibrations to match the vibration wave attenuation law.

[0038] There is a 5mm gap between the bottom of the perforated aluminum plate 8 and the gradient density polyurethane foam 7.

[0039] There is a 5mm gap between the bottom of the perforated aluminum plate 8 and the gradient density polyurethane foam 7. The perforated aluminum plate 8 and the air layer between it and the gradient density polyurethane foam 7 work together to form a resonant cavity to meet the structure required for sound absorption.

[0040] The surfaces of the lower silicone layer 11 and the upper silicone layer 13 are provided with uniformly arranged circular grooves.

[0041] The surfaces of the upper silicone layer 13 and the lower silicone layer 11 are provided with evenly distributed circular grooves, which increases the space for deformation of the upper silicone layer 13 and the lower silicone layer 11 and slows down the aging rate of the material.

[0042] A screw hole 14 is provided between the top and bottom of the lower silicone layer 11, the honeycomb aluminum plate 12, and the upper silicone layer 13. The noise reduction motor 15 is fixed to the sandwich-type shock absorption structure 10 by bolt connection through the screw hole 14.

[0043] The working principle and usage process of this utility model are as follows: During the operation of the drone, the noise-reducing motor 15 and the low-noise propeller 17 work together to reduce operating noise. Simultaneously, the sandwich-type shock absorption structure 10 further efficiently absorbs and isolates the energy generated by the high-frequency vibration of the noise-reducing motor 15 during operation. The "soft-hard-soft" layered design formed by the lower silicone layer 11, honeycomb aluminum plate 12, and upper silicone layer 13 suppresses vibration transmission while maintaining structural rigidity, ensuring the installation stability of the motor. The upper silicone layer 13 directly absorbs the high-frequency vibration of the noise-reducing motor 15. The viscoelastic properties of the upper silicone layer 13 cause multiple reflections and interferences of high-frequency waves within the material, converting energy into heat. This heat is then absorbed by the lower silicone layer. 11. The honeycomb structure of the honeycomb aluminum plate 12 in the middle of the upper silicone layer 13 can disperse the direction of vibration energy, convert point loads into surface loads, and suppress low-frequency resonance. The lower silicone layer 11 attenuates residual vibrations secondaryly. Through the cooperation of the lower silicone layer 11, the honeycomb aluminum plate 12, and the upper silicone layer 13, the vibrations generated during the operation of the noise-reducing motor 15 are effectively suppressed, the energy generated by the vibrations is dissipated, and the body radiation noise caused by the vibration of the noise-reducing motor 15 is reduced. The surfaces of the upper silicone layer 13 and the lower silicone layer 11 are provided with evenly distributed circular grooves, increasing the space for deformation of the upper silicone layer 13 and the lower silicone layer 11. Simultaneously, the sound-absorbing sponge 18 can further absorb the operating noise of the noise-reducing motor 15. Through the above technical means… Building upon the low-noise performance of the noise-reducing motor 15 itself, this device further reduces the operating noise of the motor 15. Simultaneously, the device incorporates gradient-density polyurethane foam 7 inside the hollow arm 4 and a perforated aluminum plate 8 on the front side of the hollow arm 4. During drone motor operation, low-frequency structural noise is transmitted through the arm, while the rotation of the propellers generates mid-to-high frequency aerodynamic noise. This device reduces noise from both components through the gradient sound absorption of the gradient-density polyurethane foam 7 and the resonance silencing effect of the perforated aluminum plate 8. The hollow arm 4 is filled with gradient-density polyurethane foam 7, with the density of the foam gradually increasing from the end near the drone body 1 to the end near the support base 5, gradually increasing from low density foam. The high-density foam in the gradient density polyurethane foam 7 directly resists the structural vibration transmitted by the drone arm. Its closed-cell structure converts vibration energy into heat energy through viscous friction. The medium-density foam in the middle section of the gradient density polyurethane foam 7 causes multiple reflections of sound waves through interconnected pores, consuming sound wave energy. The low-density foam close to the drone body eliminates residual vibrations to match the vibration wave attenuation law. When the airflow generated by the low-noise blades 17 impacts the surface of the drone arm, based on the Helmholtz resonance sound absorption principle, the perforated aluminum plate 8 and the air layer generated by the gap between it and the gradient density polyurethane foam 7 form a resonant cavity. For mid-to-high frequency noise, the energy is consumed by the oscillation and friction of the air column, achieving a sound absorption effect.Building upon the low-noise design of the low-noise blade 17, further absorption of its aerodynamic noise is achieved, resulting in enhanced noise reduction. This is accomplished through the combination of gradient-density polyurethane foam 7 and perforated aluminum plate 8, effectively covering a wider range of noise frequencies.

[0044] The circuits, electronic components, and modules involved are all existing technologies, which can be fully implemented by those skilled in the art, and need not be elaborated upon. The content protected by this application does not involve any improvement to the software and methods.

[0045] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0046] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The above examples are only for the purpose of helping to understand the method and core ideas of this utility model. The above description is only a preferred embodiment of this utility model. It should be noted that due to the limitations of textual expression, there are objectively infinite specific structures. For those skilled in the art, several improvements, modifications, or changes can be made without departing from the principles of this utility model, and the above technical features can also be combined in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the concept and technical solution of the utility model to other occasions without modification, should all be considered within the protection scope of this utility model.

Claims

1. An unmanned aerial vehicle (UAV) that facilitates noise reduction and sound absorption, characterized in that: The utility model provides a kind of unmanned aerial vehicle, including unmanned aerial vehicle body (1), the side of unmanned aerial vehicle body (1) is equipped with rotating mounting seat (2), the bottom of rotating mounting seat (2) is equipped with damping bearing seat (3), the bottom of damping bearing seat (3) is rotatably installed hollow machine arm (4), one end of hollow machine arm (4) is installed with support seat (5), the inside of hollow machine arm (4) is equipped with foam installation groove, the inside of foam installation groove is installed with gradient density polyurethane foam (7), the top of hollow machine arm (4) is located in the notch of foam installation groove and is screwed with perforated aluminum plate (8), the top of support seat (5) is installed with motor installation bin (9), the inside of motor installation bin (9) is installed with sandwich shock-absorbing structure (10), and the inside of motor installation bin (9) is installed with sandwich shock-absorbing structure (10), which includes lower silica gel layer (11), the top of lower silica gel layer (11) is equipped with honeycomb aluminum plate (12), the top of honeycomb aluminum plate (12) is equipped with upper silica gel layer (13), the top of upper silica gel layer (13) is equipped with noise reduction motor (15), the top of motor installation bin (9) is equipped with top cover (16), and the output end of noise reduction motor (15) penetrates top cover (16) and is connected with low-noise paddle (17).

2. The unmanned aerial vehicle of claim 1, wherein: The bottom of support seat (5) is installed with bottom foot (6).

3. The unmanned aerial vehicle of claim 1, wherein: The inside of motor installation bin (9) is also equipped with sound-absorbing sponge (18).

4. The unmanned aerial vehicle of claim 1, wherein: The density of gradient density polyurethane foam (7) gradually rises from one end close to unmanned aerial vehicle body (1) to one end close to support seat (5), in sequence, low-density foam, medium-density foam, high-density foam.

5. The unmanned aerial vehicle of claim 1, wherein: There is a 5MM gap between the bottom of perforated aluminum plate (8) and gradient density polyurethane foam (7).

6. The unmanned aerial vehicle of claim 1, wherein: The surface of lower silica gel layer (11) and upper silica gel layer (13) is equipped with uniformly arranged circular grooves.

7. The unmanned aerial vehicle of claim 1, wherein: Screw holes (14) are penetrated between the top and bottom of lower silica gel layer (11), honeycomb aluminum plate (12) and upper silica gel layer (13), and the noise reduction motor (15) and sandwich shock-absorbing structure (10) are fixed by bolt connection screw holes (14).

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