Low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device of bionic sawtooth structure

Abstract

The low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device of the bionic sawtooth structure comprises a trailing edge noise reduction device body, the trailing edge noise reduction device body comprises a mounting head, and three propeller blades are fixed to the edge of the mounting head through mounting bolts; by designing the rear edge noise reduction mechanism, the connecting plate and the sawtooth structure body can be reinforced and mounted, and when the propeller blades are operated and used after mounting, the end parts of the propeller blades and the mounting head are reinforced and mounted and used through a high-strength connecting piece, and the propeller blades rotate at a high speed; continuous airflow flowing through the rear edges of the propeller blades is divided into a plurality of small discrete airflow by the connecting plates and the sawtooth structural bodies, and the small airflow interacts after leaving the propeller blades to generate complex vortex interference, so that trailing vortex energy originally concentrated at a specific frequency is diffused to a wider frequency band, the noise peak intensity is reduced, and the noise loss is reduced. And the environment adaptability is high, the structural strength is high, and noise reduction treatment is effective.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the trailing edge noise reduction device technical field, concretely relates to a low altitude unmanned aerial vehicle propeller trailing edge noise reduction device of bionic sawtooth structure. BACKGROUND

[0002] The unmanned aerial vehicle propeller is a key component of the unmanned aerial vehicle, generates lift and thrust through rotation, realizes the flight of the unmanned aerial vehicle in the air, and needs noise reduction treatment when the unmanned aerial vehicle propeller is running. The trailing edge of the propeller is usually equipped with a noise reduction device for noise reduction, and the existing trailing edge noise reduction device is a device for noise reduction.

[0003] In terms of the optimization of the shape contour of the propeller blade of the existing unmanned aerial vehicle, the authorized patent CN220974574U discloses a noise reduction propeller and an indoor unmanned aerial vehicle. The noise radiation intensity is reduced by changing the flow field characteristics of the airflow flowing through the blade surface through special design of the blade tip, pitch and other geometric parameters, and reducing airflow separation and vortex generation. Although the noise can be reduced, a number of wind tunnel experiments show that the noise reduction effect is poor, the aerodynamic layout is damaged, the lift-drag ratio of the blade is reduced, and the flight efficiency and endurance are affected.

[0004] In the field of sound-absorbing coating application, the patent CN219428379U proposes a technical solution of setting a sound-absorbing cotton tube on each propeller end. The sound-absorbing cotton absorbs and dissipates sound energy, and the noise generated by the rotation of the propeller is weakened. The sound-absorbing coating technology takes the sound-absorbing cotton tube as an example, and works in an environment with humidity exceeding 80%. At the same time, when encountering wind and sand, the coating is easily worn and loses noise reduction.

[0005] The bionic propeller disclosed in the patent CN202110343549 reduces drag and noise. A plurality of rows of fiber fluff are arranged on the blade base layer, and a similar non-smooth surface is constructed on the blade surface to achieve the purpose of noise reduction by suppressing airflow turbulence development. In the bionic flow control structure technology, the sawtooth structure has a fatigue crack rate of 20% after running for 120 hours at a high speed (more than 8000 rpm), which threatens flight safety.

[0006] In view of the above existing technologies, it is known that the existing unmanned aerial vehicle propeller noise reduction technology has the problems of insufficient noise reduction effect, poor environmental adaptability, low structural strength, and affects the effect of noise reduction treatment of the propeller during use of the unmanned aerial vehicle. Therefore, the utility model proposes a low altitude unmanned aerial vehicle propeller trailing edge noise reduction device of bionic sawtooth structure. UTILITY MODEL CONTENTS

[0007] The utility model discloses a low altitude unmanned aerial vehicle propeller trailing edge noise reduction device of bionic sawtooth structure aims at providing a low altitude unmanned aerial vehicle propeller trailing edge noise reduction device of bionic sawtooth structure to solve the problem of insufficient noise reduction effect, poor environmental adaptability, low structural strength of existing unmanned aerial vehicle propeller noise reduction technology in the foregoing background art, which affects the effect of propeller noise reduction processing when using unmanned aerial vehicle.

[0008] In order to realize the above-mentioned purpose, the utility model provides the following technical scheme: a low altitude unmanned aerial vehicle propeller trailing edge noise reduction device of bionic sawtooth structure, including trailing edge noise reduction device main part, the trailing edge noise reduction device main part includes the mounting head, the edge of mounting head is fixed with three propeller blades through mounting bolt, the end of propeller blade is fixed with high -strength connecting piece of mounting head's junction, still be provided with on trailing edge noise reduction device main part:

[0009] The trailing edge noise reduction mechanism includes a trailing edge noise reduction assembly arranged on the surface of the end of the propeller blade, the end of the trailing edge noise reduction assembly is provided with a rotary fixing assembly, and the inner surface of the trailing edge noise reduction assembly is provided with an adhesive fixing assembly.

[0010] The protection mechanism includes a protection assembly arranged on the outer surface of the end of the propeller blade, and the inner surface of the protection assembly is provided with an anti-skid pressing assembly.

[0011] Preferably, the trailing edge noise reduction assembly includes a connecting plate arranged on the surface of the end of the propeller blade, and the surface of the connecting plate is integrally arranged in the sawtooth structure body.

[0012] Preferably, the rotary fixing assembly includes a mounting plate arranged on the end of the connecting plate and located on the surface of the propeller blade, the end of the mounting plate is integrally provided with a short plate, the short plate is fixed through a countersunk screw, and the surface of the mounting plate is threadedly connected with a fixing bolt.

[0013] Preferably, the end of the connecting plate and the surface of the propeller blade are rotatably fixed through the mounting plate and the fixing bolt.

[0014] Preferably, the adhesive fixing assembly includes an epoxy resin adhesive filled in the connecting portion of the lower surface of the connecting plate and the surface of the propeller blade, and the surface of the connecting plate is consistent with the side surface structure of the end of the propeller blade.

[0015] Preferably, the protection assembly includes a protection cover sleevedly mounted on the outer surface of the end of the propeller blade, and the inner surface of the protection cover is formed with a closed groove.

[0016] Preferably, the anti-skid pressing assembly includes an outer guard plate adhesively fixed in the closed groove, the inner surface of the outer guard plate is integrally provided with an anti-skid rubber body, and the inner surface of the anti-skid rubber body is in contact with the surface of the propeller blade.

[0017] Compared with the prior art, the utility model has the beneficial effects that:

[0018] Through design rear edge noise reduction mechanism, can connect the plate with sawtooth structure body reinforcement installation, and in the installation after the propeller blade operation uses, the end of propeller blade and installation head between through high strength connecting piece strengthens the installation use, the propeller blade high -speed rotation, the connecting plate and sawto tooth structure will be split into multiple discrete small air current after the continuous air current of the propeller blade rear edge, these small air current in the exit propeller blade and interact, produce complex vortex interference, make the originally concentrated in the specific frequency's tail vortex energy spread to more wide frequency band, thereby reduce noise peak intensity, and environmental adaptability is strong, structural strength is high, effective noise reduction treatment. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is structural schematic diagram of the utility model;

[0020] Figure 2 It is structural schematic diagram of the utility model's installation head, propeller blade and high strength connecting piece;

[0021] Figure 3 It is the utility model Figure 2 Amplification structural schematic diagram of part B;

[0022] Figure 4 It is structural schematic diagram of the utility model's connecting plate, sawtooth structure body and epoxy resin adhesive;

[0023] Figure 5 It is structural schematic diagram of the utility model's installation plate and short plate;

[0024] Figure 6 It is partial cutaway structural schematic diagram of the utility model's propeller blade and protective cover installation protection;

[0025] Figure 7 It is the utility model Figure 6 Amplification structural schematic diagram of part B;

[0026] In the drawing: 100, rear edge noise reduction device main part;101, installation head;102, propeller blade;1021, installation plate;1022, fixed bolt;1023, short plate;1024, connecting plate;1025, sawtooth structure body;1026, epoxy resin adhesive;103, protective cover;1031, closed groove;1032, outer cover;1033, antiskid rubber body;104, high strength connecting piece. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0028] Please refer to Figures 1 to 7 The utility model provides a kind of technical scheme: a low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device of bionic sawtooth structure, including trailing edge noise reduction device main body 100, trailing edge noise reduction device main body 100 includes installation head 101, the edge of installation head 101 is fixed with three propeller blades 102 by mounting bolt, propeller root position inclination angle 15 °, propeller tip position inclination angle 30 °.Propeller root is then balanced by smaller inclination angle to ensure structural stability and aerodynamic performance, and the end of propeller blade 102 is fixedly installed with high-strength connecting piece 104 at the connecting place of installation head 101, and high-strength connecting piece 104 is fully fused by glass fiber and epoxy resin, to form firm mechanical connection between propeller blade 102 and installation head 101, trailing edge noise reduction device main body 100 is also provided with:

[0029] Trailing edge noise reduction mechanism, and the trailing edge noise reduction mechanism includes the trailing edge noise reduction component arranged on the end surface of propeller blade 102, the end of the trailing edge noise reduction component is provided with rotary fixed component, and the inner surface of the trailing edge noise reduction component is provided with adhesive fixed component, so that, when propeller blade 102 is operated, connecting plate 1024 and sawtooth structure body 1025 can divide the continuous airflow passing through the trailing edge of propeller blade 102 into a plurality of discrete small airflows, these small airflows interact after leaving propeller blade 102, generate complex vortex interference, and make the originally concentrated in specific frequency tail vortex energy spread to wider frequency band.

[0030] In order to facilitate effective noise reduction treatment of propeller blade 102 by trailing edge noise reduction component, preferably, in the embodiment, the trailing edge noise reduction component includes connecting plate 1024 arranged on the end surface of propeller blade 102, and the surface of connecting plate 1024 is integrally provided in sawtooth structure body 1025, so that, when propeller blade 102 is operated, connecting plate 1024 and sawtooth structure body 1025 can divide the continuous airflow passing through the trailing edge of propeller blade 102 into a plurality of discrete small airflows, these small airflows interact after leaving propeller blade 102, generate complex vortex interference, and make the originally concentrated in specific frequency tail vortex energy spread to wider frequency band to carry out noise reduction treatment, and connecting plate 1024 and sawtooth structure body 1025 are formed by mold injection, so that smooth surface can reduce airflow friction resistance.

[0031] In order to facilitate the installation of the connecting plate 1024 and the surface of the propeller blade 102 by the rotating fixing assembly, preferably, the rotating fixing assembly includes the mounting plate 1021 arranged at the end of the connecting plate 1024 and located on the surface of the propeller blade 102. The end of the mounting plate 1021 is integrally provided with the short plate 1023. The short plate 1023 is fixed with the propeller blade 102 by means of the countersunk screw. The mounting plate 1021 can be fixed with the propeller blade 102 through the short plate 1023. The surface of the mounting plate 1021 is threadedly connected with the fixing bolt 1022. The connecting plate 1024 is fixed between the mounting plate 1021 and the propeller blade 102 again, which facilitates the installation and use.

[0032] In order to facilitate the close adhesion and increase the firmness by the adhesive fixing assembly, and have better flowability, preferably, the adhesive fixing assembly includes the epoxy resin adhesive 1026 filled in the connecting plate 1024 and the surface of the propeller blade 102. The surface of the connecting plate 1024 is consistent with the side structure of the end of the propeller blade 102. The lower surface of the connecting plate 1024 and the surface of the propeller blade 102 can be tightly adhered and fixed by the epoxy resin adhesive 1026, which facilitates the installation and use. The adhesive fixing assembly has good flowability and adhesion, can fill the small gap on the surface of the propeller blade 102, and provide initial bonding force.

[0033] The protection mechanism includes the protection assembly arranged on the outer surface of the end of the propeller blade 102. The inner surface of the protection assembly is provided with the anti-skid pressing assembly. When the propeller blade 102 is not used after use, the end of the propeller blade 102 is protected by the protection mechanism, and the sawtooth structure 1025 is not easily exposed to the outside to cause danger.

[0034] In order to protect the sawtooth structure 1025 at the end of the propeller blade 102 by the protection assembly, the sawtooth structure 1025 is not easily exposed to the outside to cause danger. Preferably, the protection assembly includes the protection cover 103 fitted and installed on the outer surface of the end of the propeller blade 102. The inner surface of the protection cover 103 is formed with the closed groove 1031. When the propeller blade 102 is placed after use, the protection cover 103 is closed and installed on the end of the propeller blade 102 for protection.

[0035] In order to tightly press and protect the use of the protection cover 103 by the anti-skid pressing assembly, preferably, the anti-skid pressing assembly includes the outer cover plate 1032 adhered and fixed in the inner part of the closed groove 1031 by the glue. The inner surface of the outer cover plate 1032 is integrally provided with the anti-skid rubber body 1033. The inner surface of the anti-skid rubber body 1033 is in contact with the surface of the propeller blade 102. When the protection cover 103 is fitted and installed on the end of the propeller blade 102, the anti-skid rubber body 1033 contacts the surface of the propeller blade 102 to reinforce the installation and protection for use.

[0036] The connecting plate 1024 and the sawtooth structure 1025 are made of high-strength carbon fiber reinforced resin matrix composite material, have high strength and lightweight characteristics, the height of a single sawtooth is 2mm, and the spacing is 8mm, and the mounting plate 1021 and the short plate 1023 are made of titanium alloy material and have high strength and corrosion resistance.

[0037] The working principle and use process of the low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device of the bionic sawtooth structure are as follows: before use, the end surface of the propeller blade 102 is first formed into a rough and porous microstructure to increase the surface area, then the connecting plate 1024 is closed on the end surface of the propeller blade 102 and fixed by epoxy resin adhesive 1026, then the mounting plate 1021 is closed and pressed on the end of the connecting plate 1024, the connecting plate 1024, the mounting plate 1021 and the propeller blade 102 are fixed and installed by rotating the fixing bolt 1022, the short plate 1023 and the propeller blade 102 are fixed by the countersunk screw on the side, so that the connecting plate 1024 and the sawtooth structure 1025 are reinforced and installed, and when the propeller blade 102 is in operation after installation, the end of the propeller blade 102 and the mounting head 101 are reinforced and installed by the high-strength connecting piece 104, the propeller blade 102 is rotated at a high speed of 8000r / min, the connecting plate 1024 and the sawtooth structure 1025 divide the continuous airflow flowing through the trailing edge of the propeller blade 102 into multiple discrete small airflows, the small airflows interact with each other after leaving the propeller blade 102, complex vortex interference is generated, the tail vortex energy originally concentrated at a specific frequency is diffused to a wider frequency band, so that the noise peak strength is reduced, the environmental adaptability and structural strength are high, the noise reduction treatment is effective, the durability and safety of the device under complex working conditions are greatly improved, and the service life of the unmanned aerial vehicle propeller is prolonged.

[0038] Then when the connecting plate 1024 and the sawtooth structure 1025 are installed on the end of the propeller blade 102 for noise reduction treatment, and when the propeller blade 102 is not in use, the protective cover 103 can be fitted on the outer surface of the end of the propeller blade 102, and after fitting and installation, the outer cover plate 1032 and the anti-skid rubber body 1033 are deformed and tightly pressed on the outer surface of the propeller blade 102 to reinforce and install the protective cover 103 after fitting and installation, so that the connecting plate 1024 and the sawtooth structure 1025 are conveniently and effectively protected when the propeller blade 102 is not in use, and it is not easy to cause danger caused by exposure to the outside world, and the safety protection of the trailing edge noise reduction device main body 100 after installation on the propeller blade 102 is improved.

[0039] Although the embodiments of the present application have been shown and described (see the detailed description above), it should be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device of bionic sawtooth structure, comprising a trailing edge noise reduction device main body (100), the trailing edge noise reduction device main body (100) comprises a mounting head (101), the edge of the mounting head (101) is fixed with three propeller blades (102) through mounting bolts, the end of the propeller blade (102) is fixedly provided with a high-strength connecting piece (104) at the connecting place with the mounting head (101), characterized in that: The rear edge noise reduction device body (100) is further provided with: ​ The rear edge noise reduction mechanism comprises a rear edge noise reduction assembly arranged on the end surface of the propeller blade (102), an end portion of the rear edge noise reduction assembly is provided with a rotation fixing assembly, and an inner surface of the rear edge noise reduction assembly is provided with an adhesive fixing assembly. The protection mechanism comprises a protection assembly arranged on the outer surface of the end portion of the propeller blade (102), and an inner surface of the protection assembly is provided with an anti-skid pressing assembly.

2. The low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device with a bionic sawtooth structure according to claim 1, characterized in that: The rear edge noise reduction assembly comprises a connecting plate (1024) arranged on the end surface of the propeller blade (102), and a surface of the connecting plate (1024) is integrally provided with a sawtooth structure (1025).

3. The low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device with a bionic sawtooth structure according to claim 2, characterized in that: The rotation fixing assembly comprises a mounting plate (1021) arranged on the end portion of the connecting plate (1024) and located on the surface of the propeller blade (102), an end portion of the mounting plate (1021) is integrally provided with a short plate (1023), the short plate (1023) is fixed to the propeller blade (102) through a countersunk screw, and a surface of the mounting plate (1021) is threadedly connected with a fixing bolt (1022).

4. The low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device with a bionic sawtooth structure according to claim 3, characterized in that: The end portion of the connecting plate (1024) and the surface of the propeller blade (102) are rotationally fixed through the mounting plate (1021) and the fixing bolt (1022).

5. The low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device with a bionic sawtooth structure according to claim 2, characterized in that: The adhesive fixing assembly comprises an epoxy resin adhesive (1026) filled at the connecting position between the lower surface of the connecting plate (1024) and the surface of the propeller blade (102), and a surface of the connecting plate (1024) is consistent with the end portion side structure of the propeller blade (102).

6. The low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device with a bionic sawtooth structure according to claim 1, characterized in that: The protection assembly comprises a protection cover (103) which is sleeved and mounted on the outer surface of the end portion of the propeller blade (102), and an inner surface of the protection cover (103) is formed with a closed groove (1031).

7. The low-altitude unmanned aerial vehicle propeller trailing edge noise reduction device with a bionic sawtooth structure according to claim 6, characterized in that: The anti-skid pressing assembly comprises an outer guard plate (1032) which is adhesively fixed in the inner portion of the closed groove (1031), an inner surface of the outer guard plate (1032) is integrally provided with an anti-skid rubber body (1033), and an inner surface of the anti-skid rubber body (1033) is in contact with the surface of the propeller blade (102).

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