Variable-pitch unmanned aerial vehicle with fixed wings

Abstract

The invention belongs to the technical field of unmanned aerial vehicles, and particularly relates to a variable-pitch unmanned aerial vehicle with fixed wings, which comprises an unmanned aerial vehicle body, rack cantilevers are symmetrically mounted at two opposite angles of the unmanned aerial vehicle body, and a power assembly is mounted at one end, far away from the unmanned aerial vehicle body, of each rack cantilever; the power assembly comprises a power mechanism and a variable-pitch mechanism, the power mechanism comprises a rotor wing, the variable-pitch mechanism comprises a fixed disc, a movable disc is arranged on the inner side of the fixed disc, a cavity is formed between the fixed disc and the movable disc, and the movable disc is connected to the rotor wing through a first connecting rod and a second connecting rod; a variable pressure mechanism is arranged at the lower part of the unmanned aerial vehicle body; fixed wings are rotationally mounted on the two sides of the unmanned aerial vehicle body; and fluid media are pumped into the cavities or pumped out of the cavities through the variable-pressure mechanisms, so that the movable disc is driven to stretch out and draw back up and down in the fixed disc, the rotor wings are driven to deflect through the movable disc, and variable-pitch adjustment of the rotor wings is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of unmanned aerial vehicles, and in particular relates to a variable-pitch unmanned aerial vehicle with fixed wings. Background Art

[0002] A variable pitch propeller is a propeller that can automatically (or manually) change the blade angle according to the flight speed and altitude during flight. Traditional multi-rotor UAVs achieve body attitude and altitude control by adjusting the speed of each rotor motor. This has high requirements on the response speed of the rotor motor speed control to ensure timely and stable control of the UAV's attitude and altitude. The attitude control of the UAV generates horizontal speed, thereby controlling the position of the UAV.

[0003] For example, a variable pitch propeller provided by Chinese patent publication number CN219468054U includes a drone housing, a motor shaft connected to a motor is rotatably assembled inside the drone housing, a propeller shaft is detachably connected to the top of the motor shaft, a propeller blade is assembled on the top of the propeller shaft through the installation of a propeller plate and a propeller seat, a pitch-changing mechanism for completing the pitch change of the propeller is provided outside the connection between the motor shaft and the propeller shaft, and a disassembly component for controlling the separation of the motor shaft and the propeller shaft is provided on the outer surface of the connection between the motor shaft and the propeller shaft. The device pulls the connecting rod to move by the up and down changes of the pitch disc, and drives the propeller blade to change its angle through the connecting rod to achieve the need for variable pitch.

[0004] For example, in the prior art described in the above patent, although the blade angle can be changed, the blade change structure is relatively complicated. When installed on a small UAV, it will increase the weight of the UAV too much, which is likely to affect the UAV's endurance and effective load. Summary of the invention

[0005] The purpose of the present invention is to provide a variable-pitch UAV with fixed wings. By moving a fixed plate and a movable plate up and down and utilizing the connection between connecting rods one and two and the rotor, the angle between the rotor and the propeller seat can be driven to change, thereby changing the angle between the rotor and the horizontal plane, realizing the change of the rotor angle and changing the pitch of the UAV.

[0006] The technical solution adopted by the present invention is as follows: A variable-pitch UAV with fixed wings comprises: a UAV body, frame cantilevers are symmetrically installed at two diagonal parts of the UAV body, and a power assembly is installed at one end of the frame cantilever away from the UAV body; the power assembly comprises a power mechanism and a pitch-changing mechanism, wherein the power mechanism comprises a rotor, the pitch-changing mechanism comprises a fixed plate, a moving plate is arranged on the inner side of the fixed plate, a cavity is formed between the fixed plate and the moving plate, a vertical telescopic structure is formed between the fixed plate and the moving plate, and the moving plate is connected to the rotor through a connecting rod 1 and a connecting rod 2; a transformer mechanism is arranged at the lower part of the UAV body, the transformer mechanism comprises a storage cylinder, and the storage cylinder is connected to the cavity through a connecting pipe; fixed wings are rotatably installed on both sides of the UAV body; a fluid medium is pumped into the cavity or the fluid medium is extracted from the cavity by the transformer mechanism, so as to drive the moving plate to telescope up and down in the fixed plate, and the rotor is driven to deflect by the moving plate to realize the variable pitch adjustment of the rotor.

[0007] In a preferred embodiment, the power mechanism further includes a driving motor mounted on the frame cantilever, a propeller seat is mounted on the top end of the driving shaft of the driving motor, and a rotor is rotatably mounted on the propeller seat.

[0008] In a preferred embodiment, the fixed plate and the movable plate are both annular structures, the fixed plate and the movable plate are sleeved on the outside of the output shaft of the driving motor, the fixed plate is fixedly mounted on the frame cantilever, and the fixed plate and the movable plate are rotating structures in the horizontal direction.

[0009] In a preferred embodiment, the connecting rod 1 is fixedly connected to the top end of the moving plate, and the connecting rod 1 and the connecting rod 2 are hingedly connected.

[0010] In a preferred embodiment, a piston is disposed inside the storage tube, a telescopic rod is connected to the outer side of the piston, and the medium filled inside the storage tube is a liquid substance.

[0011] In a preferred solution, one end of the connecting tube is connected to the storage tube, and the other end of the connecting tube is connected to the cavity on the fixed plate for communication.

[0012] In a preferred solution, each set of variable pitch mechanisms is connected to the storage cylinder via a connecting pipe, and each connecting pipe is provided with a control valve.

[0013] In a preferred embodiment, the fixed wing is rotatably connected to the drone body via a rotating shaft, and a toggle rod is inserted through the inner end of the rotating shaft.

[0014] In a preferred embodiment, a connecting rod three is hingedly connected below the toggle rod, two ends of the connecting rod three are respectively connected to the toggle rods on both sides, and a middle section of the connecting rod three is connected to a telescopic rod two.

[0015] In a preferred embodiment, the upper end surface of the fixed wing is a streamlined structure, and the lower end surface of the fixed wing is a planar structure.

[0016] The technical effects achieved by the present invention are: 1. The present invention pumps a fluid medium into the cavity or extracts the fluid medium from the cavity through a pressure changing mechanism, thereby changing the pressure in the cavity, driving the moving plate to extend and retract in the fixed plate, and utilizing the connection between the moving plate and the rotor through connecting rods 1 and 2 to drive the rotor and the propeller seat to rotate, thereby changing the angle between the rotor and the horizontal plane, and realizing the change of the rotor pitch. This driving structure for the rotor is relatively simple in structure, and even if it is installed on a small UAV, it will not increase the weight of the UAV too much, thereby avoiding affecting the effective load of the UAV; 2. The transformer mechanism of the present invention is connected to each power assembly by a separate connecting pipe, and each connecting pipe is provided with a control valve. In the specific use and adjustment process, the rotor pitch on each power assembly can be adjusted individually according to the specific flight attitude, and the blade angle of each rotor can be adjusted according to the specific use conditions, so that the pitch adjustment is flexible; 3. The present invention is provided with fixed wings on the side of the drone body. When performing horizontal flight, the fixed wings can provide upward lift for the drone, thereby reducing the rotation rate of the rotor, reducing the output power of the drive motor, and reducing the energy consumption of the drone during flight, thereby increasing the endurance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 is an enlarged structural schematic diagram of the power assembly of the present invention; Figure 3 It is a schematic diagram of the enlarged cross-section structure of the pitch-changing mechanism in the power assembly of the present invention; Figure 4 It is a planar enlarged structural schematic diagram of the rotation direction between the propeller seat and the rotor of the present invention; Figure 5 It is a schematic diagram of the enlarged structure of the voltage conversion mechanism of the present invention under the drone body when viewed from above; Figure 6 It is a schematic diagram of an enlarged bottom-view cross-section of the transformer mechanism of the present invention; Figure 7 It is a schematic diagram of the isometric structure between the drone body and the fixed wing of the present invention; Figure 8 It is a planar enlarged structural schematic diagram of the fixed wing and its driving mechanism of the present invention; Fig. 9It is a side-view enlarged structural schematic diagram of the fixed wing and its driving mechanism of the present invention; Fig.10 It is a schematic diagram of the posture structure of the fixed wing of the UAV of the present invention during flight; Fig.11 It is a schematic diagram of the posture structure of the fixed wing during the braking process of the UAV of the present invention.

[0018] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. UAV body; 2. Frame cantilever; 3. Power assembly; 4. Power mechanism; 41. Driving motor; 42. Propeller seat; 43. Rotor; 5. Pitch-changing mechanism; 51. Fixed plate; 52. Moving plate; 53. Cavity; 54. Connecting rod 1; 55. Connecting rod 2; 6. Transformer mechanism; 61. Storage cylinder; 62. Piston; 63. Telescopic rod 1; 64. Connecting pipe; 65. Control valve; 7. Fixed wing; 71. Rotating shaft; 72. Toggle rod; 73. Connecting rod three; 74. Telescopic rod two. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0020] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0021] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The phrase "in a preferred embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0022] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0023] See also Figure 1 and Figure 2As shown, the present invention provides a variable pitch UAV with fixed wings, comprising: a UAV body 1, a frame cantilever 2 is symmetrically installed at two diagonal parts of the UAV body 1, and a power assembly 3 is installed at one end of the frame cantilever 2 away from the UAV body 1; the power assembly 3 includes a power mechanism 4 and a pitch-changing mechanism 5, wherein the power mechanism 4 includes a rotor 43, and the pitch-changing mechanism 5 includes a fixed plate 51, a moving plate 52 is arranged on the inner side of the fixed plate 51, a cavity 53 is formed between the fixed plate 51 and the moving plate 52, and a vertical telescopic structure is formed between the fixed plate 51 and the moving plate 52 The moving plate 52 is connected to the rotor 43 through the connecting rod 1 54 and the connecting rod 2 55; a transformer mechanism 6 is provided at the lower part of the drone body 1, and the transformer mechanism 6 includes a storage cylinder 61, and the storage cylinder 61 is connected to the cavity 53 through a connecting pipe 64; fixed wings 7 are rotatably installed on both sides of the drone body 1; the transformer mechanism 6 is used to pump the fluid medium into the cavity 53 or to extract the fluid medium from the cavity 53, thereby driving the moving plate 52 to extend and retract up and down in the fixed plate 51, and the rotor 43 is driven to deflect through the moving plate 52, so as to realize the variable pitch adjustment of the rotor 43; When the drone is flying, the pressure of the cavity 53 between the fixed plate 51 and the moving plate 52 can be changed by the transformer mechanism 6, and the moving plate 52 and the fixed plate 51 can be driven to move up and down by the change of the pressure in the cavity 53. The rotor 43 and the propeller seat 42 are driven to rotate by the movement of the moving plate 52, thereby changing the angle between the rotor 43 and the horizontal plane to achieve the change of the propeller pitch. When the drone body 1 is flying horizontally, the volume difference between the upper and lower surfaces of the fixed wing 7 is used to provide lift for the drone, thereby reducing the output power of the drive motor 41 and increasing the endurance of the drone. The more prominent feature of the present device is that a fluid medium is pumped into the cavity 53 or the fluid medium is extracted from the cavity 53 through the pressure changing mechanism 6, thereby changing the pressure in the cavity 53, driving the movable plate 52 to extend and retract up and down in the fixed plate 51, and utilizing the connection between the movable plate 52 and the rotor 43 through the connecting rod 1 54 and the connecting rod 2 55 to drive the rotor 43 and the propeller seat 42 to rotate, thereby changing the angle between the rotor 43 and the horizontal plane, and realizing the change of the rotor 43 pitch. This driving structure for the rotor 43 is relatively simple in structure, and even if it is installed on a small UAV, it will not increase the UAV's own weight too much, thereby avoiding affecting the UAV's effective load.

[0024] See also Figure 2 and Figure 3 As shown, the power mechanism 4 also includes a driving motor 41 installed on the frame cantilever 2, and a propeller seat 42 is installed on the top of the driving shaft of the driving motor 41, and a rotor 43 is rotatably installed on the propeller seat 42; In this device, the control mechanism in the drone body 1 is used as the overall control mechanism of the drone device. The control mechanism is adjusted according to the flight attitude, and the control signal sent by the remote control device is received to control the flight of the drone. The control mechanism includes two modules, flight control and electric adjustment, to achieve stable flight of the drone. The power mechanism 4 in the power assembly 3 provides power for the flight of the UAV. The drive motor 41 installed on the frame cantilever 2 drives the propeller seat 42 to rotate horizontally, and the rotation of the propeller seat 42 drives the rotor 43 to rotate, thereby providing power for the flight of the UAV.

[0025] Please also read Figure 3 and Figure 4 As shown, the fixed plate 51 and the movable plate 52 are both annular structures, the fixed plate 51 and the movable plate 52 are sleeved on the outside of the output shaft of the driving motor 41, the fixed plate 51 is fixedly mounted on the frame cantilever 2, and the fixed plate 51 and the movable plate 52 are rotating structures in the horizontal direction; The pressure-changing mechanism 6 is used to pump fluid medium into the cavity 53 or to draw fluid medium out of the cavity 53, thereby driving the movable plate 52 to extend and retract up and down in the fixed plate 51, and the movable plate 52 drives the rotor 43 to deflect, so as to achieve the variable pitch adjustment of the rotor 43. In the specific operation process, when it is necessary to move the movable plate 52 downward, the pressure of the cavity 53 can be reduced. The method for reducing the pressure of the cavity 53 is to draw fluid medium out of the cavity 53 through the pressure-changing mechanism 6, thereby reducing the volume of the cavity 53. The movable plate 52 is driven to retract into the fixed plate 51 by its own gravity and the external volume, so as to achieve the downward movement of the movable plate 52. When it is necessary to move the movable plate 52 upward, On the contrary, it is necessary to increase the pressure of cavity 53. The method for increasing the pressure of cavity 53 is to pump the fluid medium into cavity 53 through pressure transformer 6, thereby increasing the volume of cavity 53, and the increase in the volume of cavity 53 pushes movable plate 52 to extend from fixed plate 51, so as to change the telescopic change between movable plate 52 and fixed plate 51, and realize the up and down movement through the telescopic movement of fixed plate 51, and push the upward or downward swing of connecting rod 1 54 and connecting rod 2 55 through the upward and downward movement of fixed plate 51, and pull rotor 43 and propeller seat 42 to rotate through connecting rod 1 54 and connecting rod 2 55, thereby changing the angle between rotor 43 and the horizontal plane, and changing the pitch of rotor 43.

[0026] like Figure 2 and Figure 3 As shown, the connecting rod 1 54 is fixedly connected to the top of the moving plate 52, and the connecting rod 1 54 and the connecting rod 2 55 are hingedly connected; In this embodiment, the hinged connection between the first connecting rod 54 and the second connecting rod 55 can meet the deflection requirements of the rotor 43. When the first connecting rod 54 and the second connecting rod 55 push the rotor 43 to deflect, the deflection of the rotor 43 will also drive the angle change of the second connecting rod 55 and the first connecting rod 54, thereby realizing linkage and avoiding hindering the deflection of the rotor 43. In this embodiment, the driving motor 41 drives the rotor 43 to rotate along the output shaft of the driving motor 41. Since the connecting rod 2 55 and the connecting rod 1 54 are connected to the moving plate 52, when the rotor 43 rotates along the output shaft of the driving motor 41, the moving plate 52 is driven to rotate at the same time, that is, the moving plate 52 and the fixed plate 51 will rotate relative to each other along the output shaft of the driving motor 41 because the fixed plate 51 is fixed on the frame cantilever 2.

[0027] See also Figure 5 and Figure 6 As shown, a piston 62 is disposed inside the storage cylinder 61, and a telescopic rod 63 is connected to the outside of the piston 62. The medium filled inside the storage cylinder 61 is a liquid substance. One end of a connecting tube 64 is connected to the storage cylinder 61, and the other end of the connecting tube 64 is connected to the cavity 53 on the fixed plate 51. The transformer mechanism 6 is used as a power source for the deflection of the rotor 43. It is connected to the cavity 53 on the fixed plate 51 through a connecting pipe 64. When the volume in the cavity 53 needs to be reduced, the telescopic rod 1 63 can be retracted to drive the piston 62 to move in the storage cylinder 61, so that the volume of the chamber in the storage cylinder 61 increases, thereby sucking the fluid medium in the cavity 53 into the chamber of the storage cylinder 61, so that the volume of the cavity 53 decreases. When the volume in the cavity 53 needs to be increased, the telescopic rod 1 63 can be extended to drive the piston 62 to move in the storage cylinder 61, so that the volume of the chamber in the storage cylinder 61 decreases, thereby pushing the fluid medium in the chamber of the storage cylinder 61 into the cavity 53, so that the volume of the cavity 53 increases. The dynamic plate 52 is pushed to be telescopically adjusted from the fixed plate 51 by the change in the volume of the cavity 53, so as to adjust the pitch of the rotor 43. In addition, the telescopic movement between the moving disk 52 and the fixed disk 51 is driven by squeezing or pumping the fluid medium in the storage tube 61, and the filled fluid medium can be a gaseous substance, such as air, nitrogen and other gases, or a liquid substance, such as hydraulic oil, water, etc. Since the gaseous substance is compressible, under the action of external force, the volume of the cavity 53 will change slightly, causing the rotor 43 to shake, which can easily cause the rotor 43 to break and be damaged. Therefore, in this device, hydraulic oil with less compressibility is used as the driving power.

[0028] See also Figure 5 As shown, each set of variable pitch mechanism 5 is connected to the storage cylinder 61 via a connecting pipe 64, and each connecting pipe 64 is provided with a control valve 65; The transformer mechanism 6 is connected to each power assembly 3 by a separate connecting pipe 64, and each connecting pipe 64 is provided with a control valve 65. During the specific use and adjustment process, the pitch of the rotor 43 on each power assembly 3 can be adjusted individually according to the specific flight attitude, and the blade angle of each rotor 43 can be adjusted according to the specific use conditions, so that the pitch adjustment is flexible. During the specific operation process, when it is necessary to adjust the blade angles of the rotors 43 on the four groups of power components 3 at the same time, the control valves 65 on the four connecting pipes 64 can be opened at the same time, so that the cavities 53 on each group of power components 3 are connected to the storage cylinder 61 for the convenience of changing the chamber volume of the storage cylinder 61. When it is necessary to adjust the angles of the rotors 43 on a certain group or two groups separately, the other control valves 65 can be closed and only the control valve 65 of this group can be left open, so that the cavities 53 of this group are connected to the storage cylinder 61, so that the volume of the cavities 53 can be changed by changing the volume of the storage cylinder 61, thereby changing the pitch of the rotor 43.

[0029] Please also read Figures 7 to 9 As shown, the fixed wing 7 is rotatably connected to the drone body 1 through a rotating shaft 71, a toggle rod 72 is passed through the inner end of the rotating shaft 71, a connecting rod 3 73 is hingedly connected below the toggle rod 72, both ends of the connecting rod 3 73 are respectively connected to the toggle rod 72 on both sides, and a telescopic rod 2 74 is connected to the middle section of the connecting rod 3 73; During flight, the fixed wing 7 can provide the UAV with an upward lift, thereby reducing the rotation rate of the rotor 43, reducing the output power of the drive motor 41, and reducing the energy consumption of the UAV during flight, thereby increasing the endurance; In addition, in order to generate more lift during flight, the angle between the fixed wing 7 and the drone body 1 can be adjusted by rotating the rotating shaft 71. The specific adjustment method is that the telescopic rod 2 74 is extended to drive the connecting rod 3 73 to move, and the movement of the connecting rod 3 73 is used to drive the toggle rod 72, and the toggle rod 72 is used to toggle the rotation of the rotating shaft 71, and the rotation of the rotating shaft 71 is used to drive the fixed wing 7 to deflect; See also Fig.10 As shown, when the UAV flies forward, due to the flight characteristics of the rotor UAV, the UAV body 1 will tilt in the forward direction. In order to obtain greater lift through the fixed wing 7 during the flight, and the fixed wing 7 will not hinder the passage of airflow, the fixed wing 7 can be rotated and adjusted so that the plane of the fixed wing 7 is parallel to the flight direction, so that during the flight, the airflow generates different flow velocities when passing through the upper end face and the lower end face. According to the Bernoulli principle, the fixed wing 7 can provide lift for the UAV.

[0030] The upper end surface of the fixed wing 7 is a streamlined structure, and the lower end surface of the fixed wing 7 is a flat structure. In this embodiment, the upper end surface of the fixed wing 7 adopts a streamlined structure, and the lower end surface is a planar structure, so that the flow velocity of the airflow passing through the upper end surface of the fixed wing 7 is faster than the flow velocity of the lower end surface, thereby providing lift.

[0031] Also, see Fig.11 As shown, in order to make the UAV more maneuverable and to better brake during high-speed flight, in addition to controlling the rotor 43 to rotate in the opposite direction to generate a force opposite to the flight direction to brake the flight of the UAV, in this device, the deflection of the fixed wing 7 can be adjusted so that the lower end surface of the fixed wing 7 is adjusted to be perpendicular to the flight direction or close to the perpendicular state, so that the airflow pushes against the lower end surface of the fixed wing 7 to generate a force opposite to the flight direction, thereby achieving the effect of braking the flight of the UAV; The deflection of the fixed wing 7 and the deflection of the rotor 43 can be controlled and adjusted by the control mechanism of the UAV according to the flight attitude. The two can be adjusted separately without interfering with each other, which can provide better power for the flight of the UAV, make the UAV flight control performance better, meet a better flight experience, and better complete high-demand flight missions.

[0032] The working principle of the present invention is as follows: when the UAV is flying, the pressure of the cavity 53 between the fixed plate 51 and the moving plate 52 can be changed by the transformer mechanism 6, and the moving plate 52 and the fixed plate 51 can be driven to move up and down by the change of the pressure in the cavity 53. Through the movement of the moving plate 52, the rotor 43 and the propeller seat 42 are driven to rotate, thereby changing the angle between the rotor 43 and the horizontal plane to achieve a change in the propeller pitch. When the UAV body 1 is flying horizontally, the volume difference between the upper and lower surfaces of the fixed wing 7 is used to provide lift for the UAV, thereby reducing the output power of the drive motor 41 and increasing the flight endurance of the UAV.

[0033] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A variable pitch UAV with fixed wings, characterized in that: include: A drone body (1), wherein two diagonal portions of the drone body (1) are symmetrically provided with frame cantilevers (2), and a power assembly (3) is provided at one end of the frame cantilever (2) away from the drone body (1); The power assembly (3) comprises a power mechanism (4) and a pitch-changing mechanism (5), wherein the power mechanism (4) comprises a rotor (43), and the pitch-changing mechanism (5) comprises a fixed plate (51), a moving plate (52) is arranged inside the fixed plate (51), a cavity (53) is formed between the fixed plate (51) and the moving plate (52), a vertical telescopic structure is formed between the fixed plate (51) and the moving plate (52), and the moving plate (52) is connected to the rotor (43) via a first connecting rod (54) and a second connecting rod (55); A voltage conversion mechanism (6) is provided at the lower part of the drone body (1), the voltage conversion mechanism (6) comprising a storage cylinder (61), and the storage cylinder (61) is connected to the cavity (53) via a connecting pipe (64); Fixed wings (7) are rotatably mounted on both sides of the drone body (1); The pressure changing mechanism (6) is used to pump a fluid medium into the cavity (53) or to draw the fluid medium out of the cavity (53), thereby driving the moving plate (52) to extend and retract in the fixed plate (51), and the moving plate (52) drives the rotor (43) to deflect, thereby achieving variable pitch adjustment of the rotor (43).

2. The variable-pitch UAV with fixed wings according to claim 1, characterized in that: The power mechanism (4) further comprises a driving motor (41) mounted on the frame cantilever (2), a propeller seat (42) being mounted on the top end of a driving shaft of the driving motor (41), and a rotor (43) being rotatably mounted on the propeller seat (42).

3. The variable pitch UAV with fixed wings according to claim 2, characterized in that: The fixed plate (51) and the movable plate (52) are both annular structures. The fixed plate (51) and the movable plate (52) are sleeved on the outside of the output shaft of the drive motor (41). The fixed plate (51) is fixedly mounted on the frame cantilever (2). The fixed plate (51) and the movable plate (52) are rotating structures in the horizontal direction.

4. The variable-pitch UAV with fixed wings according to claim 1, characterized in that: The connecting rod 1 (54) is fixedly connected to the top end of the movable plate (52), and the connecting rod 1 (54) and the connecting rod 2 (55) are hingedly connected.

5. The variable-pitch UAV with fixed wings according to claim 1, characterized in that: A piston (62) is arranged inside the storage cylinder (61), and a telescopic rod (63) is connected to the outside of the piston (62). The medium filled inside the storage cylinder (61) is a liquid substance.

6. The variable-pitch UAV with fixed wings according to claim 1, characterized in that: One end of the connecting tube (64) is connected to the storage cylinder (61), and the other end of the connecting tube (64) is connected to the cavity (53) on the fixed plate (51) to communicate with each other.

7. The variable-pitch UAV with fixed wings according to claim 1, characterized in that: Each set of variable pitch mechanisms (5) is connected to the storage cylinder (61) via a connecting pipe (64), and each connecting pipe (64) is provided with a control valve (65).

8. The variable-pitch UAV with fixed wings according to claim 1, characterized in that: The fixed wing (7) is rotatably connected to the drone body (1) via a rotating shaft (71), and a toggle rod (72) is inserted through the inner end of the rotating shaft (71).

9. The variable-pitch UAV with fixed wings according to claim 8, characterized in that: A third connecting rod (73) is hingedly connected below the toggle rod (72), two ends of the third connecting rod (73) are respectively connected to the toggle rods (72) on both sides, and a middle section of the third connecting rod (73) is connected to a second telescopic rod (74).

10. The variable pitch UAV with fixed wings according to claim 1, characterized in that: The upper end surface of the fixed wing (7) is a streamlined structure, and the lower end surface of the fixed wing (7) is a planar structure.

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