CN113148128A

CN113148128A - Motor inversion half-duct multi-rotor unmanned aerial vehicle aircraft

Info

Publication number: CN113148128A
Application number: CN202110503651.2A
Authority: CN
Inventors: 曾宪阳; 杨红莉
Original assignee: Nanjing Institute of Technology
Current assignee: Nanjing Institute of Technology
Priority date: 2021-05-10
Filing date: 2021-05-10
Publication date: 2021-07-23
Anticipated expiration: 2041-05-10
Also published as: CN113148128B

Abstract

A motor inverted half-duct multi-rotor unmanned aerial vehicle aircraft relates to the technical field of aircraft. The invention comprises a top plate and a bottom plate which are arranged in parallel, wherein at least four groups of mutually matched circular holes for circulation of blade rotating airflow are longitudinally arranged on the top plate and the bottom plate; a half duct is clamped between each group of circular holes between the top plate and the bottom plate, and a plurality of fixing columns are arranged on the periphery of each half duct; the height of each half duct is the distance between the upper surface of the top end of each blade and the upper surface of the bottom plate; the lower part of the bottom plate is provided with a plurality of shock absorption brackets. The motor is arranged in an inverted mode, the circular hole in the bottom plate is a cavity, no cross beam is used for blocking, the system efficiency is high, and the endurance time is longer.

Description

Motor inversion half-duct multi-rotor unmanned aerial vehicle aircraft

Technical Field

The invention relates to the technical field of aircrafts, in particular to the technical field of an unmanned aerial vehicle with an inverted motor and a half duct and multiple rotor wings.

Background

A multi-rotor unmanned aerial vehicle is a special unmanned helicopter with two or more rotor shafts. It rotates through every epaxial motor, drives the rotor to produce the lift. The collective pitch of the rotors is fixed, and the magnitude of the single-shaft propelling force can be changed by changing the relative rotating speed between different rotors, so that the running track of the aircraft is controlled. Many rotor unmanned aerial vehicle has and controls the nature strong, but VTOL and hover, freely realize hovering and the free removal in the space, have very big flexibility. The method is mainly suitable for low-altitude, low-speed and task types with vertical take-off and landing and hovering requirements.

The four-axis aircraft is commonly known as a four-rotor aircraft and a four-rotor helicopter, and is called four-axis and four-rotor for short. The four-axis aircraft is a multi-rotor aircraft. Four propellers of the four-axis aircraft are simple mechanisms with directly connected motors, and the cross-shaped layout allows the aircraft to obtain the force for rotating the aircraft body by changing the rotating speed of the motors, so that the self posture of the aircraft can be adjusted. In recent years, due to the development of micro-electromechanical control technology, the stable four-axis aircraft has attracted extensive attention, and the application prospect is very considerable.

The motor and the blades of the existing multi-rotor unmanned aerial vehicle are generally arranged upwards, so that on one hand, the blades are lack of protection, and especially the requirement on the attitude of the aircraft is higher in the landing process; secondly, the paddle is positioned at the upper part of the aircraft body, so that in order to avoid the downward airflow generated during takeoff from being blocked by the components of the aircraft body, the aircraft arm for extending the paddle is longer, the structure is complex, and the air flying attitude is not convenient to control; thirdly, in order to provide better power support for the aircraft during taking off and landing, the output quantity of the battery is larger during the operation of the battery in the initial stage, so that the endurance time of the aircraft is greatly reduced.

Disclosure of Invention

The invention aims to provide a motor-inverted semi-duct multi-rotor unmanned aerial vehicle, wherein a motor is inversely installed, a circular hole in a bottom plate is a hollow hole, no cross beam is used for blocking, the system efficiency is high, and the endurance time is longer.

A semi-ducted multi-rotor unmanned aerial vehicle with inverted motors comprises a top plate and a bottom plate which are arranged in parallel, wherein at least four groups of mutually matched circular holes for blade rotation airflow circulation are longitudinally arranged on the top plate and the bottom plate;

a semi-duct is clamped between each group of circular holes between the top plate and the bottom plate, a plurality of fixing columns are arranged on the periphery of each semi-duct, and two ends of each fixing column in the length direction are respectively connected with the top plate and the bottom plate; the height of each half duct is the distance between the upper surface of the top end of each blade and the upper surface of the bottom plate;

the lower part of the bottom plate is provided with a plurality of shock absorption brackets; each damping bracket is respectively connected with the top plate and the bottom plate through a supporting rod;

the upper end surface of the top plate is respectively provided with an aircraft control circuit board and a damping plate, and the lower end surface of the top plate is provided with an electronic speed regulator connected with a motor; the upper end face of the bottom plate is provided with a battery, and the lower end face of the bottom plate is provided with an optical flow sensor.

Preferably, the inner diameter of each half-duct of the present invention is equal to the inner diameter of a circular hole.

Preferably, each half duct of the present invention has a trapezoidal longitudinal section, and the included angle between the outer line of the half duct and the vertical direction is α, which is between-60 degrees and 60 degrees. The downward direction of the airflow can be further corrected through the aerodynamic principle, the downward airflow can be more concentrated, and the efficiency is higher.

Preferably, the side wall of each half duct of the present invention is curved, with a curvature radian between 0 and pi radians. The air friction is reduced, and the gas efficiency is improved.

Preferably, the upper surface of the top end of the blade of the present invention is located on the same horizontal plane as the upper surface of the half duct.

Preferably, each damping support comprises a U-shaped elastic sheet, a sleeve cushion and a supporting rod, the sleeve cushion is sleeved on the U-shaped elastic sheet, and the supporting rods are arranged at the tail ends of the U-shaped elastic sheets respectively. The shock absorption support who sets up carries out the shock attenuation buffering through sleeve cushion deformation on the one hand, and the deformation of on the other hand U-shaped shell fragment also plays the effect of shock attenuation buffering.

Preferably, the longitudinal inner side of the sleeve cushion facing the bottom plate and the longitudinal inner side of the half duct are in the same plane. The air flow on the air outlet is prevented from being blocked, the air flow dispersion and loss are reduced, and the system efficiency is further improved.

Preferably, the included angle between the U-shaped elastic sheet and the supporting rod is 90 degrees.

Preferably, the number of the cross members of the present invention is at least 3. The purpose that sets up to 3 crossbeams is because 3 crossbeams can let the motor rock and deformation littleer for the roof when rotating at a high speed to improve the stability of system.

Preferably, the number of the fixing columns of the present invention is at least 3 uniformly arranged.

By adopting the technical scheme, compared with the prior art, the invention has the following advantages:

1. conventional aircraft motors are all mounted upright, i.e.: the motor is arranged on the bottom plate of the aircraft, and the cross beam is arranged on the bottom plate, so that the airflow can be blocked by the cross beam when flowing downwards, and the efficiency is low. The motor is arranged in an inverted mode, the circular hole in the bottom plate is a cavity, no cross beam is used for blocking, the system efficiency is high, and the endurance time is longer.

2. The invention adopts the half duct instead of the full duct, on one hand, the downward circulation of the airflow is corrected to be right below, the airflow is not dispersed, and the efficiency is improved. On the other hand, the upper surface of the periphery of the semi-ducted ring is horizontally aligned with the upper surface of the top end of the blade, so that the air inflow of the blade can be from all directions, the air inflow range is wider, the air flow noise is smaller, and the system efficiency and the endurance time are further improved.

3. The half culvert can be designed into a trapezoid, the projection of the inner wall of the culvert in the vertical direction is an oblique line, the inner wall of the culvert is an oblique line, the diameters of upper and lower circles are different, the included angle between the outer edge line of the culvert and the vertical direction is alpha, and the range of the alpha is-60 degrees to 60 degrees. When the diameter of the upper circle is larger than that of the lower circle, the angle is positive, the half duct is in a bell mouth structure, and the large bell mouth is upward; when the diameter of the upper circle is smaller than that of the lower circle, the angle is negative, the semi-duct still has a bell mouth structure, and the large bell mouth is downward; when the diameter of the upper circle is equal to the diameter of the lower circle, the angle is zero, the half culvert is rectangular, the projection of the inner wall of the culvert in the vertical direction is a vertical line, the inner wall of the culvert is a vertical line, and the half culvert is of a straight cylinder structure at the moment. The downward direction of the airflow can be further corrected through the aerodynamic principle, the downward airflow can be more concentrated, and the efficiency is higher.

4. The projection of the inner wall of the duct of the semi-duct is a curve in the vertical direction, the inner wall is a curved surface, the diameters of upper and lower circles are different, and the radian of the curve is between 0 and pi radian, so that the air friction can be further reduced, and the gas efficiency is improved.

5. The damping support provided by the invention has the advantages that on one hand, the damping buffering is carried out through the deformation of the sleeve cushion, and on the other hand, the deformation of the U-shaped elastic sheet also has the damping buffering effect. And the U-shaped elastic sheet can enable the position of the damping support to deviate from the outer edge of the circular hole, so that airflow on the air outlet hole is prevented from being blocked, airflow dispersion and loss are reduced, and the system efficiency is further improved.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a side view of the invention after assembly.

Fig. 3 is a bottom view of fig. 2.

Fig. 4 is a top view of fig. 2.

Fig. 5 is a schematic structural view of the base plate 1 of the present invention.

Fig. 6 is a schematic view of the structure of the top plate 2 of the present invention.

Fig. 7a is a schematic view of an assembly structure of the U-shaped elastic piece 6 and the supporting rod 11 of the present invention.

Fig. 7b is a schematic view of an assembly structure of the U-shaped elastic sheet 6 and the sleeve cushion 7.

Fig. 8a is a schematic position diagram of the U-shaped elastic sheet 6 and the supporting rod 11 in a normal state.

Fig. 8b is a schematic position diagram of the U-shaped elastic sheet 6 after being stressed and the supporting rod 11.

Figure 9 is a schematic structural view of the half-duct 12 of the present invention.

Figure 10 is a partial exploded view of the semi-ducted, blade position of the present invention.

Fig. 11 is a mounting structure diagram of the semi-duct and blade position of the invention.

Figure 12 is a schematic view of the angle of the semi-ducted ramp of the present invention.

Wherein: 1. the device comprises a bottom plate, a top plate, a motor, a paddle, a bottom plate, a top plate, a bottom plate, a motor, a bottom plate, an electronic speed regulator, a bottom plate, a circular hole, a bottom plate, a supporting rod, a bottom plate, a circular hole, a supporting rod, a bottom plate, a supporting rod, a bottom plate, a circular hole, a supporting rod, a bottom plate, a supporting rod.

Detailed Description

The technical scheme of the invention is explained in detail in the following with the accompanying drawings:

as shown in fig. 1-12, a motor-inverted semi-ducted multi-rotor unmanned aerial vehicle comprises a top plate 2 and a bottom plate 1 which are arranged in parallel, wherein at least four groups of mutually matched circular holes for blade rotation airflow circulation are longitudinally arranged on the top plate 2 and the bottom plate 1, a plurality of cross beams are uniformly arranged in each circular hole on the top plate 2, the cross beams in each circular hole are intersected in the center of the circular hole, a motor 3 is arranged in each circular hole, the upper end part of the motor 3 is connected with the center of the circular hole, and blades 4 are arranged at the lower end part of the motor 3;

a half duct 12 is clamped between each group of circular holes between the top plate 2 and the bottom plate 1, a plurality of fixing columns 13 are arranged on the periphery of each half duct 12, and two ends of each fixing column in the length direction are respectively connected with the top plate 2 and the bottom plate 1; the height of each half-duct 12 is the distance between the upper surface 18 of the top end of the blade 4 and the upper surface of the bottom plate 1;

the lower part of the bottom plate 1 is provided with a plurality of shock absorption brackets; each damping bracket is respectively connected with the top plate 2 and the bottom plate 1 through a support rod 11;

an aircraft control circuit board 16 and a damping plate 15 are respectively arranged on the upper end surface of the top plate 2, and an electronic speed regulator 5 connected with the motor 3 is arranged on the lower end surface of the top plate 2; the battery 17 is disposed on the upper end surface of the base plate 1, and the optical flow sensor 8 is disposed on the lower end surface of the base plate 1.

According to the invention, four circular holes are formed in an aircraft bottom plate 1 of the unmanned aerial vehicle with the inverted motor and the half duct for circulating the rotating airflow of the blades. 4 round holes are also formed on the aircraft top plate 2 and are opposite to the round holes on the bottom plate 1. N cross beams 10 are arranged on each circular hole of the top plate 2, and the cross beams 10 are intersected in the center of the circular hole. The motor 3 is installed at the right center, and n is 3 in this embodiment in order to reduce the vibration caused by the high-speed rotation of the motor 3. The motor 3 is arranged at the bottom of the top plate 2 in an inverted mode, and the paddle 4 is also arranged on a shaft of the motor 3 in an inverted mode.

As shown in fig. 1, 2, 7a and 7b, the invention is provided with a shock absorption bracket on a bottom plate 1, wherein the shock absorption bracket is composed of a U-shaped elastic sheet 6, a sleeve cushion 7 and a support rod 11. The sleeve cushion 7 is sleeved on the U-shaped elastic sheet 6, and the assembly drawing is shown in figure 7 b. The shock attenuation effect includes two aspects: when the aircraft lands, the sleeve cushion 7 contacts the ground firstly, so that the sleeve cushion 7 plays a role in shock absorption; u-shaped shell fragment 6 is connected with 11 verticals of bracing piece, and after sleeve cushion 7 touched ground and took place deformation when the aircraft descends, U-shaped shell fragment 6 also began to take place deformation, promptly: θ changes from 90 degrees to less than 90 degrees as shown in fig. 8a and 8 b. Thus, the U-shaped elastic sheet 6 also plays a role in shock absorption and buffering. Through the damping effect, the aircraft can not violently impact the ground to cause equipment damage when landing. The purpose of the U-shaped spring 6 is also another aspect: after the damping support is installed on the bottom plate 1, the position of the damping support is just deviated from the outer side of the edge of the circular hole 9, so that air flow blown out from the circular hole 9 is prevented from being blocked, resistance is reduced, and system efficiency is improved, as shown in fig. 1, fig. 2, fig. 3 and fig. 4.

The circular hole 9 of the bottom plate 1 is provided with a half-duct 12. The bottom of the half-culvert 12 is mounted on the circular hole 9 of the bottom plate 1, coaxial with the circular hole 9. And m fixing columns 13 are arranged on the outer side of the periphery of the half duct 12 and used for fixing the half duct. To ensure stability m in this example is taken to be 4. The duct height h of the half-ducts 12 is smaller than the distance between the bottom plate 1 and the top plate 2, i.e.: less than the length of the support rods 11. When the semi-ducted segment 12 is installed, the upper surface 18 of the blade tips is in direct horizontal alignment with the upper surface 14 of the semi-ducted annulus, as shown in figures 10 and 11. The beneficial effect that design brought like this is: the half-duct is arranged, so that the airflow generated by the rotation of the blades 4 flows towards the right lower side under the action of the half-duct, the airflow dispersion is reduced, and the efficiency is improved. On the other hand, the half bypass is provided instead of the full bypass because a larger intake flow range of the blades 4 is ensured. The purpose of having the upper surfaces 18 of the tips of the blades in direct horizontal alignment with the upper surfaces 14 of the semi-ducted annuluses is to reduce the resistance of the incoming air flow through the blades, the extent of the incoming air flow, and the noise of the air flow. The problem of current full duct aircraft inefficiency, air current noise big is solved.

Circuit connection: the battery 17 is connected with the aircraft control circuit board 16, the electronic speed regulator 5 and the optical flow sensor 8. The aircraft control circuit board 16 is connected with the electronic speed regulator 5 and the optical flow sensor 8, and the electronic speed regulator 5 is connected with the motor 3.

Conventional aircraft motors are all mounted upright, i.e.: the motor is arranged on the bottom plate of the aircraft, and the cross beam is arranged on the bottom plate, so that the airflow can be blocked by the cross beam when flowing downwards, and the efficiency is low. The motor is arranged in an inverted mode, the circular hole in the bottom plate is a cavity, no cross beam is used for blocking, the system efficiency is high, and the endurance time is longer.

The invention adopts the half duct instead of the full duct, on one hand, the downward circulation of the airflow is corrected to be right below, the airflow is not dispersed, and the efficiency is improved. On the other hand, the upper surface of the periphery of the semi-ducted ring is horizontally aligned with the upper surface of the top end of the blade, so that the air inflow of the blade can be from all directions, the air inflow range is wider, the air flow noise is smaller, and the system efficiency and the endurance time are further improved. If the full-bypass is adopted, the air inlet flow of the blades is blocked by the upper cross beam of the top plate, the system efficiency is low, and the endurance time is short.

The semi-ducted structure of the present invention comprises the following forms:

(1) the half culvert is arranged in a straight cylinder shape, namely the diameters of upper and lower circles of the culvert are the same.

(2) The longitudinal section of the half-duct is trapezoidal, the projection of the inner wall of the duct in the vertical direction is oblique lines, the inner wall is oblique lines, and the diameters of the upper circle and the lower circle are different, as shown in fig. 12. The duct outer sideline is alpha with vertical direction contained angle, and alpha's scope is between-60 degrees to 60 degrees, and the angle is positive when last circle diameter is greater than down circle diameter, and the angle is the negativity when last circle diameter is less than down circle diameter, and in this embodiment, alpha sets up to 5 degrees. The purpose of setting up like this can further rectify the downward direction of air current through the gas dynamics principle, and can make the decurrent air current more concentrated, and efficiency is higher.

(3) The projection of the inner wall of the half duct in the vertical direction is a curve, the inner wall is a curved surface, the diameters of the upper circle and the lower circle are different, as shown in fig. 10 and 11, the radian of the curve is between 0 and pi radian, and the radian is set to be 0.1 in the embodiment. The purpose of this arrangement can be further reduced air friction, improve gas efficiency.

As shown in fig. 7a, 7b, 8a and 8b, the shock absorbing bracket of the present invention has the shock absorbing and buffering effects due to the deformation of the sleeve cushion, and the deformation of the U-shaped resilient piece has the shock absorbing and buffering effects, and it can be seen from the figure that θ changes from 90 degrees of the initial position to an acute angle. And the U-shaped elastic sheet can enable the position of the damping support to deviate from the outer edge of the circular hole, so that airflow on the air outlet hole is prevented from being blocked, airflow dispersion and loss are reduced, and the system efficiency is further improved.

As shown in fig. 3 and 4, the purpose of the present invention is to provide three beams, which can reduce the sway and deformation of the motor relative to the top plate during high-speed rotation, so as to improve the stability of the system.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.

Claims

1. A motor-inverted semi-ducted multi-rotor unmanned aerial vehicle is characterized by comprising a top plate (2) and a bottom plate (1) which are arranged in parallel, wherein at least four groups of mutually matched circular holes for circulation of blade rotating airflow are longitudinally arranged on the top plate (2) and the bottom plate (1), a plurality of cross beams are uniformly arranged in each circular hole on the top plate (2), the cross beams in each circular hole are intersected in the center of the circular hole, a motor (3) is arranged in each circular hole, the upper end part of the motor (3) is connected with the center of the circular hole, and blades (4) are arranged at the lower end part of the motor (3);

a half duct (12) is clamped between each group of circular holes between the top plate (2) and the bottom plate (1), a plurality of fixing columns (13) are arranged on the periphery of each half duct (12), and two ends of each fixing column in the length direction are respectively connected with the top plate (2) and the bottom plate (1); the height of each half duct (12) is the distance between the upper surface (18) of the top end of the blade (4) and the upper surface of the bottom plate (1);

the lower part of the bottom plate (1) is provided with a plurality of shock absorption brackets; each damping support is respectively connected with the top plate (2) and the bottom plate (1) through a support rod (11);

an aircraft control circuit board (16) and a damping plate (15) are respectively arranged on the upper end surface of the top plate (2), and an electronic speed regulator (5) connected with the motor (3) is arranged on the lower end surface of the top plate (2); the upper end surface of the bottom plate (1) is provided with a battery (17), and the lower end surface of the bottom plate (1) is provided with an optical flow sensor (8).

2. The inverted-motor semi-ducted multi-rotor drone aircraft according to claim 1, characterized in that the internal diameter of each of the above mentioned semi-ducts (12) is equal to the internal diameter of a circular hole.

3. The inverted-motor semi-ducted multi-rotor unmanned aerial vehicle as claimed in claim 1, wherein the longitudinal cross-section of each semi-duct (12) is trapezoidal, the outer edge line of the semi-duct (12) forms an angle α with the vertical direction, and α is between-60 degrees and 60 degrees.

4. The inverted-motor semi-ducted multi-rotor unmanned aerial vehicle as claimed in claim 1, wherein the side walls of each semi-duct (12) are curved with a curvature radian between 0 and pi radians.

5. The inverted-motor semi-ducted multi-rotor unmanned aerial vehicle as claimed in claim 1, wherein the blade tip upper surface (18) and the semi-ducted upper surface (14) are located on the same horizontal plane.

6. The unmanned aerial vehicle with the inverted half ducts and the multiple rotor wings as claimed in claim 1, wherein each of the shock-absorbing brackets comprises a U-shaped elastic sheet (6), a sleeve cushion (7) and a support rod (11), the sleeve cushion (7) is sleeved on the U-shaped elastic sheet (6), and the support rods (11) are respectively arranged at the ends of the U-shaped elastic sheet (6).

7. The inverted-motor semi-ducted multi-rotor unmanned aerial vehicle as claimed in claim 6, wherein the longitudinal inner side of the sleeve cushion (7) facing the base plate (1) is coplanar with the longitudinal inner side of the semi-ducted (12).

8. The unmanned aerial vehicle with inverted motors and half ducts as claimed in claim 6, wherein the angle between the U-shaped elastic sheet (6) and the supporting rod (11) is 90 degrees.

9. The inverted-motor, semi-ducted, multi-rotor unmanned aerial vehicle of claim 1, wherein the number of said cross-members is at least 3.

10. The unmanned aerial vehicle with inverted motor, half ducted multi-rotor as defined in claim 1, wherein said stationary posts (13) are at least 3 evenly arranged.