Double-folding propeller structure suitable for small-sized cylinder-launched unmanned aerial vehicle

Abstract

The invention relates to the technical field of unmanned aerial vehicles, in particular to a double-folding propeller structure suitable for a small cylindrical unmanned aerial vehicle, and the structure comprises a propeller hub which is connected with a transmission shaft on the unmanned aerial vehicle; each paddle is connected with the propeller hub through a propeller hub hinging mechanism; each propeller hub hinge mechanism comprises a connecting piece, one end of each connecting piece is hinged to the corresponding propeller hub through a first pin shaft, and the other end of each connecting piece is hinged to the corresponding blade root through a second pin shaft. A torsional spring mechanism is further arranged at the connecting position of the root of the paddle and the connecting piece and controls the paddle to be naturally unfolded around the hinge point. Through the double-folding design of the propeller blades and the propeller hub, the storage space can be effectively reduced, the unmanned aerial vehicle can be conveniently put into the launching canister, it is ensured that enough thrust can be provided after the unmanned aerial vehicle is unfolded, and the power requirement of the unmanned aerial vehicle in the take-off and flight process is met.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles (UAVs), and in particular to a double-folding propeller structure suitable for a small-sized tube-launched UAV. Background Art

[0002] With the continuous development of drone technology, particularly in the aerospace sector, tube-launched drones are becoming an increasingly important application. These drones typically require high portability and maneuverability, particularly in terms of space requirements during storage and launch. Traditional drone propellers, often fixed or folding, often fail to meet the compact design requirements of tube-launched drones.

[0003] While existing folding propellers can reduce storage space, their blade folding does not take into account the folding of the hub. As a result, the structure still occupies a large space even after folding, making it ineffective for adapting to the size requirements of the launch tube. Furthermore, existing folding structures also have certain issues with stability and reliability when unfolded. Therefore, there is an urgent need for a new folding propeller structure that can meet the compactness requirements of tube-launched UAVs during launch and ensure stable power output during flight. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a double-folding propeller structure suitable for small tube-launched UAVs. Through the double-folding design of the blades and the hub, this structure can effectively reduce the storage space, facilitate the placement of the UAV into the launch tube, and ensure that it can provide sufficient thrust after unfolding to meet the power requirements of the UAV during take-off and flight.

[0005] The first object of the present invention is to provide a double-folding propeller structure suitable for a small tube-launched UAV, comprising: A propeller hub, which is connected to the drive shaft on the drone; A plurality of blades, each blade being connected to the hub via a hub hinge mechanism; Each hub hinge mechanism includes a connecting member, one end of which is hinged to the hub via a first pin, and the other end of which is hinged to the root of the blade via a second pin; The axis of the first pin is parallel to the axis of the hub; the axis of the second pin is perpendicular to the axis of the hub; A torsion spring mechanism is further provided at the connection between the root of the blade and the connecting piece, and the torsion spring mechanism controls the blade to unfold naturally around the hinge point.

[0006] Preferably, the torsion spring mechanism includes torsion springs sleeved on both ends of the second pin shaft, and a connecting rod provided between the two torsion springs; Each torsion spring includes a fixed end and a torsion end, wherein the fixed end is bent into a hook shape and inserted into a hole provided on the connecting member; the torsion end is connected to the connecting rod; The portion where the blade root and the connecting member are hinged via the second pin is located between the two torsion springs; Each of the blades drives the connecting rod to rotate under the action of the torsion spring torque of the two torsion springs to push the blade to unfold naturally to adapt to the flight state of the drone.

[0007] Preferably, the connecting rod corresponds to the portion between the blade body and the root.

[0008] Preferably, metal flange anti-loosening nuts are provided at both ends of the second pin shaft and outside the torsion spring.

[0009] Preferably, the propeller hub is a strip-shaped propeller hub, the center of which is connected to the transmission shaft on the drone.

[0010] Preferably, two blades are provided, wherein one blade is provided at one end of the hub and the other blade is provided at the other end of the hub.

[0011] Preferably, when the double-folding propeller structure is stored, the connecting members are rotated toward the center of the hub to perform a first folding, and the blades hinged to the connecting members are rotated in a direction perpendicular to the hub to perform a second folding.

[0012] The second object of the present invention is to provide a small tube-fired UAV, comprising: a fuselage and a propeller; The propeller structure is a double-folding propeller structure suitable for small tube-launched UAVs.

[0013] Preferably, the connecting parts in the propeller of the UAV are rotated in a direction parallel to the hub to perform a first folding, and the blades hinged to the connecting parts are rotated in a direction perpendicular to the hub to perform a second folding. After the first folding and the second folding, the UAV is stored in the launch tube.

[0014] The present invention has at least the following beneficial effects: The present invention provides a double-folding propeller structure suitable for a small-sized tube-launched UAV, which is mainly reflected in the following aspects: Reduced space usage: Through the double-folding design, the propeller blades and hub can be folded into a compact form when not in use, significantly reducing space usage during storage and transportation, which is particularly suitable for the design requirements of tube-launched UAVs.

[0015] Adaptable to tube-launched launch: The folded propellers easily fit into the launch tube, meeting the launch space restrictions of tube-launched drones. Once deployed, they quickly return to their working state, ensuring stability and thrust output during flight.

[0016] Improved maneuverability: The folded propeller structure allows the drone to take up less space during transportation and storage, thereby improving the drone's maneuverability.

[0017] Reliability and durability: The folding mechanism of the present invention ensures that the folding and unfolding process is stable and reliable through a precise hinge device and an auxiliary drive device. It can withstand frequent folding operations and has a long service life.

[0018] Efficient power output: The unfolded propellers can provide sufficient thrust to ensure that the tube-launched drone can take off quickly and fly stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the double-folding propeller structure suitable for small tube-launched UAVs; Figure 2 This is a schematic diagram of the propeller in the deployed state; Figure 3 This is a schematic diagram of the connection details between the hub and the blade; Figure 4 is a cross-sectional schematic diagram of the folding mechanism; Figure 5 Schematic diagram of the propeller folding inside the launch tube. DETAILED DESCRIPTION

[0020] In order to illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following is a detailed description with reference to the embodiments.

[0021] The main purpose of this invention is to provide a double-folding propeller structure suitable for small tube-launched drones. This structure, through the double-folding design of the blades and hub, effectively reduces storage space, facilitates the placement of the drone in the launch tube, and ensures that after deployment, it can provide sufficient thrust to meet the power requirements of the drone during takeoff and flight.

[0022] See also Figures 1 to 5 As shown, a double-folding propeller structure suitable for a small tube-launched UAV includes a hub 1 and a plurality of blades 2; A propeller hub 1 is connected to a transmission shaft 4-1 on the drone; each propeller blade 2 is connected to the propeller hub 1 via a propeller hub hinge mechanism; each propeller hub hinge mechanism includes a connector 3, one end of which is hinged to the propeller hub 1 via a first pin, and the other end is hinged to the root of the propeller blade 2 via a second pin 3-1; Among them, the axis of the first pin is parallel to the axis of the hub 1; the axis of the second pin 3-1 is perpendicular to the axis of the hub 1; a torsion spring mechanism 6 is also provided at the connection between the root of the blade 2 and the connecting member 3, and the torsion spring mechanism 6 controls the blade 2 to unfold naturally around the hinge point.

[0023] When the double-folding propeller structure of the present invention is stored, the connecting member 3 is rotated toward the center of the hub 1 to perform a first fold, and the blades hinged to the connecting member 3 are rotated perpendicular to the hub 1 to perform a second fold. This realizes a double-folding propeller for the drone, making it easier to place the drone into the launch tube.

[0024] In order to realize the torsion spring mechanism to control the blades to unfold naturally around the hinge point, a torsion spring mechanism 6 is provided, which includes torsion springs 6-1 sleeved on both ends of the second pin 3-1, and a connecting rod 6-2 provided between the two torsion springs 6-1; Each torsion spring 6-1 includes a fixed end and a torsion end, wherein the fixed end is bent into a hook shape and inserted into a hole provided on the connecting member 3; the torsion end is connected to the connecting rod 6-2; The part where the root of the blade 2 is hinged to the connector 3 via the second pin 3-1 is located between the two torsion springs 6-1; Each of the blades 2 drives the connecting rod 6 - 2 to rotate under the action of the torsion spring torque of the two torsion springs 6 - 1 to push the blade 2 to unfold naturally to adapt to the flight state of the drone.

[0025] The connecting rod 6 - 2 corresponds to the portion between the main body and the root of the blade 2 .

[0026] Metal flange anti-loosening nuts are also provided at both ends of the second pin shaft 3 - 1 and outside the torsion spring 6 - 1 .

[0027] It should be noted that the second pin shaft can be set as a pin to replace the metal flange anti-loosening nut at one end of the second pin shaft 3-1.

[0028] To achieve a hinged connection between the second pin connector and the blade root, a concave slot is provided at the end of the connector. The blade root is inserted into the slot, and a second pin extends from one side of the slot, passes through the blade root, and then exits from the other side of the slot, thus achieving a hinged connection between the second pin connector and the blade root. A torsion spring and a metal flange locknut are then mounted on each end of the second pin.

[0029] In this embodiment, the propeller hub 1 is a strip-shaped propeller hub, the center of which is connected to the transmission shaft 4-1 on the drone.

[0030] Two blades 2 are provided, wherein one blade is provided at one end of the hub 1 and the other blade is provided at the other end of the hub 1 .

[0031] In order to realize the hinged connection between the connecting piece and the hub, a concave through groove is opened at the end of the hub, and the end of the connecting piece is embedded in the through groove. A first pin shaft is extended from one side of the through groove, passes through the end of the connecting piece, and then passes through the other side of the through groove, thereby realizing the hinged connection between the connecting piece and the hub through the first pin shaft. In addition, metal flange anti-loosening nuts are also provided at both ends of the first pin shaft to prevent the pin shaft from loosening.

[0032] In order to illustrate that a double-folding propeller structure provided by the present invention is applicable to a small-sized tube-launched UAV, the present invention also provides a small-sized tube-launched UAV, comprising: a fuselage and a propeller; The structure of the propeller is the above-mentioned double-folding propeller structure suitable for small tube-launched UAVs.

[0033] Among them, the connecting parts 3 in the propeller of the drone are rotated in a direction parallel to the hub 1 for the first folding, and the blades hinged to the connecting parts 3 are rotated in a direction perpendicular to the hub 1 for the second folding. After the first folding and the second folding, the drone is stored in the launch tube 5.

[0034] In this embodiment, the design process of a dual-folding propeller structure of a tube-launched UAV includes: Hub design: The hub adopts a foldable design with multiple movable joints. When not in use, the hub can be folded to the required storage state to adapt to the space requirements of tube-fired launch.

[0035] Propeller Design: The propeller blades are connected to the hub via hinged joints and can be folded around the hinge point. When folded, the propeller blades rotate along their roots, remaining perpendicular or nearly perpendicular to the hub, ensuring the smallest possible folded volume.

[0036] Folding mechanism: The folding mechanism consists of a hinge device, springs, etc., which can convert the blades and hub from the working state to the folding state when needed, ensuring the stability of the folding and unfolding process.

[0037] Tube-launched adaptation design: This structure is particularly suitable for tube-launched UAVs. The folded propeller can be easily placed in the launch tube and unfolded to the working state through the drive mechanism during launch, ensuring that the UAV can take off quickly and provide the required thrust.

[0038] To further illustrate the double-folding propeller structure for a small-sized tube-launched UAV provided by the present invention, the following is also included in the specific implementation process: First, determine that the hub and blade lengths account for 20% and 80% of the total propeller length (diameter), respectively. Excluding the approximately 5% non-lift surface at the blade root, the effective aerodynamic surface length of the blade accounts for approximately 75% of the total propeller length (diameter). Next, determine the rotation axes of the blade and hub hinge mechanisms, respectively. The specific methods are as follows: According to the spatial constraints between the UAV and the launch tube, the root of the blade is used as the blade rotation axis, and the hub hinge axis is taken at a ratio of 50%, 55%, 60%, 65%, and 70% of the half length of the hub from the center of the hub, and the hinge mechanism and the blade are rotated according to the hub hinge rotation axis and the blade rotation axis until the blade does not interfere with the UAV and the launch tube. This state is the final folding state of the hub hinge mechanism and the blade, and the corresponding rotation axis position and rotation angle are the rotation axis position and folding angle of the hub hinge mechanism and the blade in the final folding state.

[0039] Finally, before launching the drone, the propeller hub hinge and blades are rotated to the appropriate folding angle to accommodate the spatial constraints between the launch tube and the drone. During launch, the torsion spring torque of the hinge mechanism causes the blades to naturally unfold, adapting to the drone's flight state.

[0040] The specific working principle is as follows: See also Figure 5 As shown, the propeller hub fixed part 1 and the blade 2 are connected by a hinge mechanism 3. The blade 2 can rotate and fold around the hinge point. In the working state, the blade 2 is unfolded and fixed by the locking mechanism, driving the rotation of the hub 1 to generate thrust. Figure 1 As shown, when storage or transportation is required, the hinge mechanism 3 is folded to a corresponding angle around its rotation axis, and the blade 2 is folded to a corresponding angle around the hinge point of the hinge mechanism 3, so that the blade and the hub hinge mechanism remain vertical or nearly vertical. The folded structure greatly reduces the occupied space and is easy to place into the launch tube.

[0041] See also Figure 3 and Figure 4 As shown, the hinge mechanism enables the connection structure between the blades and the hub to reliably complete the folding and unfolding process. In particular, during the unfolding process, the folding mechanism can stably unfold the blades and hub from the folded state through the torsion spring mechanism and fix them in the working position, ensuring thrust output during flight.

[0042] The design of this propeller is particularly suitable for tube-launched UAVs. The folded propeller can be easily placed in the launch tube. After launch, the propeller is restored to the working state through the electric drive device and spring, quickly starts and provides the required thrust to ensure that the UAV takes off quickly.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A double-folding propeller structure suitable for a small tube-launched UAV, characterized in that: include: A propeller hub (1) connected to a transmission shaft (4-1) on the UAV; A plurality of blades (2), each blade (2) being connected to the hub (1) via a hub hinge mechanism; Each hub hinge mechanism comprises a connecting member (3), one end of which is hinged to the hub (1) via a first pin, and the other end of which is hinged to the root of the blade (2) via a second pin (3-1); The axis of the first pin is parallel to the axis of the hub (1); the axis of the second pin (3-1) is perpendicular to the axis of the hub (1); A torsion spring mechanism (6) is further provided at the connection between the root of the blade (2) and the connecting member (3), and the torsion spring mechanism (6) controls the blade (2) to unfold naturally around the hinge point.

2. The double-folding propeller structure for a small-sized tube-launched UAV according to claim 1 is characterized in that: The torsion spring mechanism (6) comprises torsion springs (6-1) sleeved on both ends of the second pin shaft (3-1), and a connecting rod (6-2) arranged between the two torsion springs (6-1); Each torsion spring (6-1) comprises a fixed end and a torsion end, wherein the fixed end is bent into a hook shape and inserted into a hole provided on the connecting member (3); the torsion end is connected to the connecting rod (6-2); The portion where the root of the blade (2) is hinged to the connecting member (3) via the second pin (3-1) is located between the two torsion springs (6-1); Each of the blades (2) drives the connecting rod (6-2) to rotate under the action of the torsion spring torque of the two torsion springs (6-1) to push the blade (2) to unfold naturally, thereby adapting to the flight state of the drone.

3. The double-folding propeller structure suitable for a small-sized tube-launched UAV according to claim 2 is characterized in that: The connecting rod (6-2) corresponds to the portion between the main body and the root of the blade (2).

4. The double-folding propeller structure suitable for a small tube-launched UAV according to claim 2 is characterized in that: Metal flange anti-loosening nuts are also provided at both ends of the second pin shaft (3-1) outside the torsion spring (6-1).

5. The double-folding propeller structure suitable for a small tube-launched UAV according to claim 1 is characterized in that: The propeller hub (1) is a strip-shaped propeller hub, the center of which is connected to the transmission shaft (4-1) on the UAV.

6. The double-folding propeller structure for a small-sized tube-launched UAV according to claim 5 is characterized in that: Two blades (2) are provided, wherein one blade is provided at one end of the hub (1), and the other blade is provided at the other end of the hub (1).

7. The double-folding propeller structure for a small-sized tube-launched UAV according to claim 1 is characterized in that: When the double-folding propeller structure is stored, the connecting member (3) is rotated toward the center of the hub (1) to perform a first folding, and the blades hinged to the connecting member (3) are rotated in a direction perpendicular to the hub (1) to perform a second folding.

8. A small tube-launched UAV, characterized in that: include: fuselage and propellers; The structure of the propeller is a double-folding propeller structure suitable for a small tube-launched UAV as described in any one of claims 1 to 7.

9. The small tube-launched UAV according to claim 8, characterized in that: The connecting member (3) in the propeller of the UAV is rotated in a direction parallel to the propeller hub (1) to perform a first folding, and the blade hinged to the connecting member (3) is rotated in a direction perpendicular to the propeller hub (1) to perform a second folding. After the first folding and the second folding, the UAV is stored in the launch tube (5).

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