Water-air dual-purpose unmanned aerial vehicle

Abstract

The invention discloses a water-air dual-purpose unmanned aerial vehicle, relates to the technical field of unmanned aerial vehicles, and aims to solve the problems of large accommodating volume and poor reliability under special working conditions. The water-air dual-purpose unmanned aerial vehicle comprises a ship body, a foldable vehicle arm, an outer wrapping air bag, an air pump, a pressure control unit and a controller, the outer wrapping air bag covers the lower portion of the foldable vehicle arm in a semi-wrapping mode, and the outer wrapping air bag and one end of the foldable vehicle arm are relatively fixed; the air pump is connected with the outer wrapping air bag and used for inflating air into the outer wrapping air bag. The pressure control unit comprises a pressure valve and a pressure sensor in the outer wrapping air bag, and the pressure valve is used for overpressure protection; after the outer wrapping air bag expands, the foldable machine arms are driven to be unfolded to be in a working state, the controller controls the inflation speed, start and stop of the air pump, and the pressure valve is used for overpressure protection. After being exhausted, the outer wrapping air bag shrinks and drives the foldable machine arms to be folded. The water-air dual-purpose unmanned aerial vehicle is used for reducing the storage size, improving the environmental adaptability and enhancing the reliability of the folding mechanism.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and more particularly to a dual-purpose (water and air) UAV. Background Technology

[0002] Traditional drones are primarily designed for aerial flight. Their fixed airframe structure occupies a significant amount of space during transport and storage, making them unsuitable for carrying and deploying in confined spaces. This is especially true in space-constrained environments such as shipboard or vehicle-mounted applications, where the fixed size of traditional drones severely limits their application scope.

[0003] To address the size issue, some foldable drone designs have emerged in the current technology, using mechanical structures such as hinges and sliding rails to fold the arms. However, these foldable designs have several drawbacks: First, exposed moving parts are easily damaged by impacts during transportation or operation, affecting their lifespan; second, in high-speed flight or windy conditions, the folding joints of the arms are prone to vibration or deformation, leading to drone instability and affecting flight accuracy and safety; furthermore, existing folding mechanisms often require complex locking devices and manual intervention, making rapid automatic unfolding and folding impossible, reducing ease of use. This is especially true for amphibious drones, whose operating environments are more complex and variable, facing both high-altitude strong winds and humid water surfaces, where traditional folding mechanisms struggle to meet reliability requirements under these special conditions. Summary of the Invention

[0004] The purpose of this invention is to provide an amphibious unmanned aerial vehicle (UAV) that reduces storage volume, improves environmental adaptability, and enhances the reliability of the folding mechanism.

[0005] To achieve the above objectives, the present invention provides an amphibious unmanned aerial vehicle (UAV), comprising a hull, a foldable arm, a power unit, an external airbag, an air pump, a pressure control unit, and a controller. The first end of the foldable arm is rotatably connected to the hull. The power unit includes a propeller and a drive motor, with the drive motor fixedly mounted at the second end of the foldable arm, and the propeller and drive motor being drive-connected. The external airbag partially covers the underside of the foldable arm, and is fixed relative to the second end of the foldable arm. The air pump is connected to the external airbag and is used to inflate the external airbag with gas. The pressure control unit includes a pressure valve mounted on the outer airbag and a pressure sensor inside the outer airbag. The pressure valve is used for overpressure protection. The controller is located inside the hull and is connected to the pressure sensor and the air pump. When the air pump starts, gas enters the outer airbag. After the outer airbag inflates, it drives the foldable arm to unfold to the working state. The controller controls the inflation speed and start / stop of the air pump according to the feedback signal from the pressure sensor. The pressure valve is used for overpressure protection to maintain the pressure inside the outer airbag within a preset range. After the outer airbag deflates, it contracts and drives the foldable arm to fold.

[0006] For example, in the above-mentioned amphibious drone, the outer airbag and the hull are relatively fixed by a snap-fit ​​structure. One end of the snap-fit ​​structure is fixed to the outer airbag, and the other end can be inserted into a slot set on the hull.

[0007] For example, the pressure valve is an automatic pressure valve, used to automatically release the gas in the outer airbag to balance the internal and external pressure when the external air pressure decreases during the drone's ascent.

[0008] Specifically, the outer airbag can be made of polyester fiber or polyester fiber composite material.

[0009] For example, there are four foldable arms and four power units, symmetrically arranged on both sides of the hull, and the foldable arms can be folded inward.

[0010] Furthermore, the hull has a first sealed compartment and a second sealed compartment. The amphibious unmanned aerial vehicle also includes a piston engine, a generator, and a power battery. The piston engine is located in the first sealed compartment; the generator is located in the first sealed compartment and is connected to the crankshaft assembly of the piston engine; the power battery is located in the second sealed compartment. The power output terminals of both the power battery and the generator are electrically connected to the drive motor. The piston engine and the power battery can provide power to the drive motor independently or jointly. The power output terminal of the generator is also electrically connected to the power input terminal of the power battery, so that the piston engine can charge the power battery through the generator during operation.

[0011] Furthermore, the aforementioned amphibious drone also includes a water immersion sensor, which is used to detect whether the amphibious drone is in a water environment; when the signal from the water immersion sensor indicates that the drone has left the water area and the power battery charge is below a preset threshold, the controller controls the solenoid valve to open and start the piston engine.

[0012] Furthermore, the piston engine is a two-stroke direct injection engine, including a combustion chamber, a fuel supply system, an air supply system, and a fuel rail; the combustion chamber is composed of the piston, cylinder, and cylinder head of the piston engine; the fuel supply system is used to supply and inject fuel; the air supply system is used to supply compressed air; the fuel rail is connected to the fuel supply system and the air supply system; wherein, the compressed air provided by the air supply system and the fuel provided by the fuel supply system are pre-mixed in the fuel rail and then injected together into the combustion chamber.

[0013] Furthermore, the fuel supply system includes fuel injectors connected to the fuel rail; the air supply system includes air injectors and an air pump assembly, the air injectors being connected to the air inlet, and the air pump assembly being driven by the crankshaft assembly of the piston engine to generate compressed air; the piston engine also includes a chuck nozzle, through which compressed air and fuel are mixed in the fuel rail and then injected into the combustion chamber.

[0014] Furthermore, the fuel supply system also includes a mechanical pump, a fuel filter, a primary fuel pump, and a secondary fuel pump. The mechanical pump draws fuel from the fuel tank; the fuel filter is connected to the outlet of the mechanical pump; the inlet of the primary fuel pump is connected to the fuel filter; the inlet of the secondary fuel pump is connected to the outlet of the primary fuel pump, and its outlet is connected to the fuel inlet of the fuel rail; the fuel rail also has a return port, which is connected to the return port of the primary fuel pump through a pipeline to form a fuel circuit.

[0015] Furthermore, the primary fuel pump includes a thermostatic heater, an electric pump core, and a temperature sensor. The thermostatic heater is used to heat the fuel in the pump chamber; the electric pump core is used to provide primary boost pressure to the fuel; and the temperature sensor is used to monitor the fuel temperature. Both the thermostatic heater and the temperature sensor are electrically connected to the controller.

[0016] Furthermore, the amphibious drone also includes an air filter silencer, which is connected to the air inlet of the air pump assembly.

[0017] Furthermore, the piston engine also includes spark plugs and glow plugs, with the spark plugs mounted on the cylinder head and the glow plugs mounted on the cylinder head; wherein the glow plugs are electrically connected to the controller.

[0018] Furthermore, this application also proposes that the amphibious unmanned aerial vehicle (UAV) further includes a sealed air intake and exhaust system, which includes an air intake port, an air intake channel, and a first solenoid valve; the air intake port is located on the outer wall of the hull; one end of the air intake channel is connected to the air intake port, and the other end is connected to the air supply system; the first solenoid valve is located on the air intake channel and is electrically connected to the controller; wherein, when the UAV is in air or surface mode, the controller controls the solenoid valve to open, and when the UAV is in underwater mode, the controller controls the solenoid valve to close.

[0019] Furthermore, the sealed intake and exhaust system also includes a pressure relief valve, a second solenoid valve, and an exhaust port; the pressure relief valve is located between the intake passage and the first sealed enclosure, and is electrically connected to the controller; the second solenoid valve is located at the exhaust port, and is electrically connected to the controller; the exhaust port is located on the outer wall of the hull; wherein, when the intake passage pressure reaches a certain threshold, the controller controls the pressure relief valve to open, allowing the gas in the intake passage to enter the first sealed enclosure, and the controller also controls the second solenoid valve to open, so that the gas cools the piston engine and is discharged from the exhaust port.

[0020] As can be seen from the above, the amphibious unmanned aerial vehicle (UAV) provided in this application has the following beneficial effects: 1. The outer airbag acts as a flexible protective layer, covering the underside of the foldable arm. Its buffering characteristics effectively absorb external impact energy, reducing the risk of damage to the foldable arm joints upon impact. Simultaneously, the outer airbag reduces the risk of vibration and deformation of the foldable arm. Combined with closed-loop control of the pressure sensor and air pump, the internal pressure of the airbag is dynamically adjusted, and the pressure valve provides overpressure protection, ensuring a smooth and reliable deployment process without manual intervention, significantly improving the reliability and environmental adaptability of the folding mechanism. 2. Significantly improved endurance and flight performance. The adoption of a hybrid electric power system coordinates the working modes of the piston engine and the power battery, achieving efficient energy distribution and recycling. The bidirectional energy flow design of the generator powers both the motor and the battery, greatly extending endurance, increasing flight altitude and distance, and meeting the needs of long-duration, large-scale operations. 3. Optimized combustion efficiency and power output. Through the air-clamping nozzle structure and fuel rail mixing chamber design, fully premixed compressed air and fuel are achieved, forming a uniform combustible mixture, significantly improving combustion efficiency and reducing emissions. Combining multi-stage fuel supply and constant temperature control ensures fuel atomization and supply stability, improving engine power output and economy. 4. Reliable adaptability to both water and air environments: The sealed intake and exhaust system, through intelligent control of the first and second solenoid valves, enables reliable switching between water and air environments for the drone. The coordinated operation of the intake channel and pressure relief valve ensures stable air intake and pressure management under different media, effectively preventing water intrusion and guaranteeing the safety and reliability of the system during cross-media operations. 5. High integration and comprehensive performance enhancement: The integrated design of the inflatable folding structure, hybrid powertrain, and sealed intake and exhaust system combines portability, long endurance, environmental adaptability, and multi-functionality. The modular architecture supports expanded applications, and the intelligent control system ensures simple and safe operation, enabling efficient and stable drone operation in complex environments. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of an amphibious unmanned aerial vehicle in its deployed state according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a folded underwater drone according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the internal structure of an amphibious unmanned aerial vehicle in its deployed state, as described in an embodiment of the present invention. Figure 4This is a partial structural schematic diagram of an amphibious unmanned aerial vehicle (UAV) according to an embodiment of the present invention; Figure 5 This is a cross-sectional view of a piston engine of an amphibious unmanned aerial vehicle (UAV) according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the component connections of a piston engine for an amphibious unmanned aerial vehicle (UAV) according to an embodiment of the present invention. Figure 7 This is a side sectional view of an amphibious unmanned aerial vehicle (UAV) according to an embodiment of the present invention.

[0022] Figure label: 1-Hull; 101-First Sealed Enclosure; 102-Second Sealed Enclosure; 2-Foldable Arm; 3-Power Unit; 31-Propeller; 32-Drive Motor; 4-Outer Airbag; 5-Air Pump; 6-Pressure Control Unit; 61-Pressure Valve; 62-Pressure Sensor; 7-Controller; 8-Piston Engine; 81-Combustion Chamber; 811-Piston; 812-Cylinder; 813-Cylinder Head; 82-Fuel Supply System; 821-Fuel Injector; 822-Mechanical Pump; 823-Fuel Filter; 824-First Stage Fuel Pump; 8241-Thermostatic Heater; 824 2-Electric pump core; 8243-Temperature sensor; 825-Secondary fuel pump; 83-Air supply system; 831-Air injector; 832-Air pump assembly; 84-Fuel rail; 841-Fuel return port; 85-Air chuck nozzle; 86-Spark plug; 87-Glow plug; 9-Generator; 11-Power battery; 12-Air filter muffler; 13-Sealed intake and exhaust system; 131-Intake port; 132-Intake passage; 133-First solenoid valve; 134-Pressure relief valve; 135-Second solenoid valve; 136-Exhaust port; 14-Floor bracket; 15-GPS. Detailed Implementation

[0023] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0024] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0026] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] Traditional drones are primarily designed for aerial flight. Their fixed airframe structure occupies a significant amount of space during transport and storage, making them unsuitable for carrying and deploying in confined spaces. This is especially true in space-constrained environments such as shipboard or vehicle-mounted applications, where the fixed size of traditional drones severely limits their application scope.

[0029] To address the size issue, some foldable drone designs have emerged in the current technology, using mechanical structures such as hinges and sliding rails to fold the arms. However, these foldable designs have several drawbacks: First, exposed moving parts are easily damaged by impacts during transportation or operation, affecting their lifespan; second, in high-speed flight or windy conditions, the folding joints of the arms are prone to vibration or deformation, leading to drone instability and affecting flight accuracy and safety; furthermore, existing folding mechanisms often require complex locking devices and manual intervention, making rapid automatic unfolding and folding impossible, reducing ease of use. This is especially true for amphibious drones, whose operating environments are more complex and variable, facing both high-altitude strong winds and humid water surfaces, where traditional folding mechanisms struggle to meet reliability requirements under these special conditions.

[0030] To solve the above problems, such as Figure 1 , Figure 2 and Figure 3 As shown, this embodiment of the invention provides an amphibious unmanned aerial vehicle (UAV), including a hull 1, a foldable arm 2, a power unit 3, an external airbag 4, an air pump 5, a pressure control unit 6, and a controller 7. The first end of the foldable arm 2 is rotatably connected to the hull 1. The power unit 3 includes a propeller 31 and a drive motor 32. The drive motor 32 is fixedly mounted on the second end of the foldable arm 2, and the propeller 31 is drive-connected to the drive motor 32. The external airbag 4 partially covers the lower part of the foldable arm 2, and the external airbag 4 is fixed relative to the second end of the foldable arm 2. The air pump 5 is connected to the external airbag 4 and is used to fill the external airbag 4 with gas. The pressure control unit 6 includes a pressure valve 61 mounted on the external airbag 4 and a pressure sensor 62 inside the external airbag 4. The pressure valve 61 is used for overpressure protection. The controller 7 is located inside the hull 1 and is signal-connected to the pressure sensor 62 and the air pump 5.

[0031] When the amphibious drone is required to operate, the controller 7 activates the air pump 5, allowing gas to enter the outer airbag 4. Since the outer airbag 4 is fixed to the second end of the foldable arm 2, the expansion of the outer airbag 4 generates a linear tension, causing the foldable arm 2 to unfold to its working position. The controller 7 controls the inflation speed and operation of the air pump 5 based on feedback signals from the pressure sensor 62, ensuring the pressure inside the outer airbag 4 reaches a preset range. The pressure sensor 62 monitors the airbag pressure in real time. When the pressure exceeds the preset upper limit, the controller 7 shuts off the air pump 5, and the pressure valve 61 releases excess gas; when the pressure falls below the lower limit, the air pump 5 is restarted to replenish the air. This closed-loop control maintains the stability of the outer airbag 4, preventing structural damage from overpressure or positioning deviations from underpressure. When retracting, the outer airbag 4 is deflated, and during its contraction, it applies a counterforce to the foldable arm 2, causing it to fold to its retracted position.

[0032] Compared with existing technologies, the airbag 4 of the amphibious drone provided in this application embodiment allows for the folding and unfolding of the foldable arm 2 during inflation and deflation, thereby reducing the storage volume. Furthermore, the airbag 4, acting as a flexible protective layer, covers a portion of the foldable arm 2, effectively absorbing external impact energy through its cushioning properties, reducing the risk of damage to the joints of the foldable arm 2 upon impact, and simultaneously mitigating the risk of arm vibration and deformation. Combined with the closed-loop control of the pressure sensor 62 and the air pump 5, the internal pressure of the airbag is dynamically adjusted, and the pressure valve 61 provides overpressure protection. By balancing the pressure, the airbag maintains the designed shape and rigidity at any altitude, ensuring that the drone's aerodynamic characteristics and flight stability are unaffected by altitude changes, guaranteeing a smooth and reliable unfolding process without manual intervention, and significantly improving the reliability and environmental adaptability of the folding mechanism. In summary, the amphibious drone provided in this application embodiment has the advantages of reduced storage volume, improved environmental adaptability, and enhanced reliability of the folding mechanism.

[0033] For example, the pressure inside the outer airbag 4 can reach a preset range of 0.3-0.5 bar. Of course, in other embodiments of this application, the pressure inside the outer airbag 4 can also reach other values, which can be adjusted according to parameters such as the size of the drone and the material of the outer airbag 4. This application does not impose specific limitations.

[0034] For example, in the aforementioned amphibious UAV, the outer airbag 4 is relatively fixed to the hull 1 via a snap-fit ​​structure. One end of the snap-fit ​​structure is fixed to the outer airbag 4, and the other end can be inserted into a slot provided on the hull 1. The snap-fit ​​structure provides a reliable and secure connection. The engagement of the snap-fit ​​and the slot is a mechanical interlock, which effectively and rigidly fixes the flexible outer airbag 4 to the hull 1, preventing relative displacement or detachment of the airbag from the hull 1 during inflation or flight, thus ensuring the stability of the amphibious UAV. It also facilitates quick disassembly, maintenance, and replacement of the outer airbag 4, which is crucial for rapid deployment in the field, post-battle recovery, and airbag replacement, cleaning, or repair, greatly improving the maintainability and serviceability of the equipment.

[0035] For example, pressure valve 61 is an automatic pressure valve 61, used to automatically release gas from the outer airbag 4 to balance the internal and external pressures when the external air pressure decreases during the drone's ascent. When the drone is flying at high altitude, the external atmospheric pressure drops significantly. If the pressure inside the airbag remains constant, the pressure difference between the inside and outside will increase, posing a risk of overpressure expansion or even rupture. Automatic pressure valve 61 can passively respond to changes in external pressure, promptly releasing excess gas and always keeping the airbag operating within a safe pressure difference range, without requiring intervention from controller 7, thus ensuring high reliability.

[0036] Specifically, the outer airbag 4 can be made of polyester fiber or polyester fiber composite material. Polyester fiber and polyester fiber composite material have high tensile strength and tear resistance, and can withstand inflation pressure and flight load with extremely light weight, realizing the pursuit of weight reduction for amphibious UAVs, and ensuring the service life of the outer airbag 4.

[0037] For example, there are four foldable arms 2 and four power units 3, symmetrically arranged on both sides of the hull 1. The foldable arms 2 can be folded inwards. The symmetrical four-arm layout (which can be "X" or "+") provides uniform and symmetrical lift and torque, ensuring the inherent stability of the aircraft in various attitudes and providing good handling performance. Folding inwards maximizes space utilization, making the overall envelope volume after folding close to the size of the hull 1 itself, achieving extreme compactness and facilitating packing and carrying.

[0038] Furthermore, such as Figure 4 As shown, the hull 1 has a first sealed compartment 101 and a second sealed compartment 102. The amphibious unmanned aerial vehicle also includes a piston engine 8, a generator 9, and a power battery 11. The piston engine 8 is located in the first sealed compartment 101; the generator 9 is located in the first sealed compartment 101 and is connected to the crankshaft assembly of the piston engine 8; the power battery 11 is located in the second sealed compartment 102. The power output terminals of both the power battery 11 and the generator 9 are electrically connected to the drive motor 32, allowing the piston engine 8 and the power battery 11 to provide power to the drive motor 32 independently or jointly. The power output terminal of the generator 9 is also electrically connected to the power input terminal of the power battery 11, enabling the piston engine 8 to charge the power battery 11 via the generator 9 during operation. The first sealed compartment 101 is an independent, sealed space for accommodating the piston engine 8 and the generator 9. Specifically, it can be constructed using materials such as aluminum alloy or carbon fiber composites, combined with sealing elements such as rubber sealing rings and waterproof breathable membranes. This structure can isolate the power system from external moisture and impurities. The second sealed compartment 102 refers to an independent sealed space for storing the power battery 11. Specifically, it can be achieved by using a carbon fiber composite shell in conjunction with sealing elements such as a waterproof and breathable membrane. This design ensures the battery's heat dissipation requirements while preventing liquid from seeping in.

[0039] When the UAV performs long-endurance missions, the piston engine 8 drives the generator 9 to generate electricity, which directly supplies the drive motor 32 and simultaneously charges the power battery 11. When a high-power output is required, the power battery 11 and the generator 9 can jointly supply power to the drive motor 32. When the piston engine 8 stops running, the power battery 11 supplies power to the drive motor 32 alone. This dual-energy system, through a physically isolated compartment design, avoids mutual interference between the fuel system and the electrical system. At the same time, the charging circuit established between the generator 9 and the power battery 11 forms an energy closed loop, allowing the excess energy of the piston engine 8 to be converted into electrical energy for storage.

[0040] Compared to existing technologies, traditional UAVs mostly use a single power source, such as pure battery power or direct-drive internal combustion engine, which suffers from limited range or sluggish power response. Existing hybrid power solutions typically connect the generator 9 in parallel with the battery, but do not consider the physical isolation requirements of different energy systems, which can easily lead to electromagnetic interference and thermal management failures. This solution achieves physical isolation of the energy system through a double-sealed chamber structure, while establishing an intelligent energy distribution mechanism to ensure the stability of power output and improve energy utilization efficiency. Through the above technical solution, this application achieves power redundancy guarantee for the UAV in complex environments. When one power source fails, the other energy source can immediately take over the driving mission. The dual-energy collaborative working mode allows the UAV to automatically switch the optimal power combination according to mission requirements. For example, battery power is used to reduce noise during take-off and landing on the water surface, and internal combustion engine is used to increase range during long-distance cruise. Underwater, the power battery 11 can be used to supply power, preventing water from entering the piston engine 8. The energy closed-loop system effectively recovers excess engine power, reducing energy waste by about 30% compared to traditional hybrid power systems. The sealed chamber structure gives the power system a high degree of waterproof protection, enabling it to adapt to harsh environmental conditions such as high humidity and salt spray.

[0041] Furthermore, the aforementioned amphibious drone also includes a water immersion sensor, which detects whether the drone is in a water environment. When the sensor indicates that the drone has left the water and the battery level 11 is below a preset threshold, the controller 7 controls the solenoid valve to open and starts the piston engine 8. The biggest risk of power switching in traditional amphibious equipment lies in misjudging the environment. If the intake valve is mistakenly opened and the piston engine 8 is started while the drone is still partially or completely underwater, water will be instantly sucked into the engine intake, causing severe engine damage (liquid slugging), stalling, or even complete failure. The water immersion sensor provides direct and reliable environmental awareness. It ensures that the controller 7 will only perform the high-risk operation of opening the intake valve and starting the piston engine 8 after physically confirming that the drone has completely left the water (e.g., it has surfaced), thus eliminating the possibility of water entering the engine.

[0042] Furthermore, such as Figure 4 , Figure 5 and Figure 6 As shown, the piston engine 8 is a two-stroke direct injection engine, including a combustion chamber 81, a fuel supply system 82, an air supply system 83, and a fuel rail 84. The combustion chamber 81 is composed of the piston 811, cylinder 812, and cylinder head 813 of the piston engine 8. The fuel supply system 82 supplies and injects fuel; the air supply system 83 supplies compressed air; the fuel rail 84 is connected to the fuel supply system 82 and the air supply system 83. The compressed air supplied by the air supply system 83 and the fuel supplied by the fuel supply system 82 are pre-mixed in the fuel rail 84 before being injected into the combustion chamber 81. Pre-mixing within the fuel rail 84 and the use of a two-stroke structure reduce engine size and improve combustion stability through precise control of the mixing ratio. In existing technologies, fuel atomization relies on high-pressure injection or complex atomizers; this solution utilizes the synergistic effect of compressed air and fuel to achieve natural atomization, reducing energy loss. This solves the problems of insufficient fuel atomization and large fluctuations in combustion efficiency in traditional UAVs under complex environments. The premixing process of fuel and air within the fuel rail 84 ensures fuel homogeneity, maintaining a stable combustion state even during high-speed flight or underwater operations. The two-stroke structure, combined with air-fuel injection technology, achieves high efficiency and reliability of power output within a limited space, avoiding the risk of power loss or flameout due to uneven mixing.

[0043] Furthermore, such as Figure 6As shown, the fuel supply system 82 includes a fuel injector 821 connected to the fuel inlet; the air supply system 83 includes an air injector 831 and an air pump assembly 832. The air injector 831 is connected to the fuel rail 84, and the air pump assembly 832 is driven by the crankshaft assembly of the piston engine 8 to generate compressed air; the piston engine 8 also includes a clamp nozzle 85, through which compressed air and fuel are mixed in the fuel rail 84 and then injected into the combustion chamber 81. The fuel rail 84 can be a tubular structure integrating fuel and air mixing channels, providing a premixing space for fuel and compressed air. The clamp nozzle 85 is an injection device with an atomizing structure that promotes fuel atomization through airflow shearing. The air injector 831 stably delivers the compressed air generated by the air pump assembly 832 to the fuel rail 84. The air pump assembly 832 utilizes engine kinetic energy to form a continuous supply of compressed air. Fuel is injected into the fuel rail 84 through the injector 821, while the air pump assembly 832, driven by the crankshaft assembly, generates compressed air, which is then delivered to the fuel rail 84 via the air injector 831. The two media create a turbulent flow within the mixing chamber, with the compressed air breaking the fuel into fine particles, forming a two-phase gas-liquid flow. The air-jet nozzle 85 accelerates the injection of the mixture, further refining the fuel particles. After entering the combustion chamber 81, the premixed air-jet fuel exhibits improved atomization, resulting in a more uniform combustion reaction upon ignition.

[0044] Compared to existing technologies, traditional engines use sequential injection, where fuel and air mix within the combustion chamber 81, resulting in short mixing time and insufficient atomization. This solution extends the fuel-air mixing time by pre-mixing within the fuel rail 84, and combined with the secondary atomization effect of the air-fuel nozzle 85, effectively improves the mixing quality. In existing technologies, the compressed air system is independent of the fuel supply system 82. This solution uses the crankshaft assembly to drive the air pump assembly 832, achieving energy reuse in the power system, avoiding additional energy consumption, and improving energy efficiency.

[0045] Furthermore, the fuel supply system 82 also includes a mechanical pump 822, a fuel filter 823, a primary fuel pump 824, and a secondary fuel pump 825. The mechanical pump 822 draws fuel from the fuel tank; the fuel filter 823 is connected to the outlet of the mechanical pump 822; the inlet of the primary fuel pump 824 is connected to the fuel filter 823; the inlet of the secondary fuel pump 825 is connected to the outlet of the primary fuel pump 824, and its outlet is connected to the fuel inlet of the fuel rail 84; the fuel rail 84 also has a return port 841, which is connected to the return port 841 of the primary fuel pump 824 via a pipeline, forming a fuel circuit. After being drawn from the fuel tank by the mechanical pump 822, the fuel passes through the fuel filter 823 to remove impurities and enters the primary fuel pump 824 for initial pressurization. The fuel output from the primary fuel pump 824 enters the secondary fuel pump 825 for secondary pressurization, and is finally delivered to the fuel rail 84 in a high-pressure state. When the pressure in the fuel rail 84 exceeds a set threshold, some fuel returns to the inlet of the first-stage fuel pump 824 through the return port 841, forming a dynamic pressure balance. This closed-loop circuit ensures continuous fuel circulation, preventing vapor lock in the fuel system. The two-stage turbocharging structure reduces the load fluctuation of the single-stage pump through pressure gradient distribution, while achieving precise control of the fuel rail 84 pressure through return fuel regulation. By connecting two pumps in series to achieve graded pressure boosting, the workload of the single-stage pump is reduced, and pressure self-balancing is achieved through the circuit design. Simultaneously, the return fuel is guided to the inlet of the first-stage pump to form a local circulation, maintaining system pressure stability and improving fuel efficiency.

[0046] Furthermore, the primary fuel pump 824 includes a thermostatic heater 8241, an electric pump core 8242, and a temperature sensor 8243. The thermostatic heater 8241 is used to heat the fuel in the pump chamber; the electric pump core 8242 is used for primary fuel pressurization; and the temperature sensor 8243 is used to monitor the fuel temperature. Both the thermostatic heater 8241 and the temperature sensor 8243 are electrically connected to the controller 7. The thermostatic heater 8241 starts in low-temperature environments, using an electric heating element to gradually heat the fuel in the pump chamber, reducing the fuel viscosity to a preset range. The temperature sensor 8243 collects fuel temperature data in real time and feeds it back to the controller 7. When the detected temperature is below a set threshold, the controller 7 activates the thermostatic heater 8241; when the temperature reaches the upper threshold, the controller 7 shuts off the heating and maintains thermal inertia balance. This solves the problems of decreased fuel pumping efficiency and system stability in low-temperature environments, prevents wax buildup in the pump chamber and insufficient fuel supply pressure, and avoids the risk of fuel vaporization caused by high temperatures.

[0047] Furthermore, the amphibious unmanned aerial vehicle also includes an air filter silencer 12, which is connected to the air inlet 131 of the air pump assembly 832. The air filter silencer 12 can prevent impurities from accumulating inside the air pump assembly 832 and reduce airflow noise generated during the air intake process.

[0048] Furthermore, the piston engine 8 also includes a spark plug 86 and a glow plug 87. The spark plug 86 is mounted on the cylinder head 813; the glow plug 87 is mounted on the cylinder head 813; and the glow plug 87 is electrically connected to the controller 7. The addition of the glow plug 87, combined with the automatic adjustment by the controller 7, enables the engine to maintain stable combustion even in extreme environments. This solves the problem of starting difficulties caused by poor fuel atomization in low-temperature or high-humidity environments for UAV engines. By combining active heating with intelligent control, combustion efficiency is improved, enabling the engine to start quickly and maintain stable operation under different environmental conditions.

[0049] Furthermore, such as Figure 7 As shown, the amphibious unmanned aerial vehicle (UAV) also includes a sealed air intake and exhaust system 13, which includes an air intake 131, an air intake passage 132, and a first solenoid valve 133. The air intake 131 is located on the outer wall of the hull 1. One end of the air intake passage 132 is connected to the air intake 131, and the other end is connected to the air supply system 83. The first solenoid valve 133 is located on the air intake passage 132 and is electrically connected to the controller 7. When the UAV is in air or surface mode, the controller 7 controls the solenoid valve to open; when the UAV is in underwater mode, the controller 7 controls the solenoid valve to close. When the UAV is in air or surface operation mode, the controller 7 sends an opening command to the first solenoid valve 133, creating a smooth path in the air intake passage 132, allowing external air to enter the air supply system 83 through the air intake 131 to meet the oxygen supply required for engine combustion. When switching to underwater navigation mode, controller 7 sends a shutdown command, and the first solenoid valve 133 blocks the air intake passage 132, forming a physical isolation barrier to prevent water from flowing back into the engine system through the air intake 131. This control method, based on automatic switching of operating modes, achieves dynamic adjustment of the sealing performance of the intake and exhaust systems by monitoring the UAV's status in real time and coordinating with the actuators. This improves the reliability of UAV operation and enables the UAV to safely switch operating modes in different media environments, such as water and air.

[0050] Furthermore, the sealed intake and exhaust system 13 also includes a pressure relief valve 134, a second solenoid valve 135, and an exhaust port 136. The pressure relief valve 134 is located between the intake passage 132 and the first sealed chamber 101, and is electrically connected to the controller 7. The second solenoid valve 135 is located at the exhaust port 136 and is electrically connected to the controller 7. The exhaust port 136 is located on the outer wall of the hull 1. When the intake pressure reaches a certain threshold, the controller 7 controls the pressure relief valve 134 to open, allowing gas in the intake passage 132 to enter the first sealed chamber 101. The controller 7 also controls the second solenoid valve 135 to open, and the gas cools the piston engine 8 before being discharged from the exhaust port 136. When the UAV is in aerial or surface mode, the pressure sensor 62 in the intake passage 132 monitors the pressure value in real time. When the pressure exceeds a preset threshold, the controller 7 sends an opening signal to the pressure relief valve 134, allowing some high-pressure gas to enter the first sealed chamber 101 through the pressure relief valve 134. Simultaneously, controller 7 triggers the second solenoid valve 135 to open, guiding the remaining gas to flow over the surface of piston engine 8 for cooling before being discharged from exhaust port 136. When the UAV switches to underwater mode, controller 7 closes the second solenoid valve 135 and keeps the pressure relief valve 134 closed. At this time, the air intake passage 132 and exhaust port 136 form a double sealing barrier to prevent water from seeping into the engine compartment and to avoid structural damage caused by excessive air intake pressure.

[0051] For example, when the drone is flying at low altitude, if the pressure in the air intake passage 132 is greater than 105 kPa, the controller 7 controls the pressure relief valve 134 to open. Of course, in other embodiments of this application, the opening pressure of the pressure relief valve 134 can also be other values, which can be adjusted according to the size of the drone, the parameters of the air intake passage 132, the parameters of the piston engine 8, etc., and this application does not impose specific limitations.

[0052] Furthermore, a first sealing gasket is provided at the first solenoid valve 133 to ensure the seal between the air intake 131 and the piston engine 8. A second sealing gasket is provided at the second solenoid valve 135 to ensure the seal between the exhaust port 136 and the piston engine 8. For example, both the first and second sealing gaskets can be made of oil-resistant nitrile rubber; if operation in harsh underwater environments is required, polyurethane can be used as the material for both the first and second sealing gaskets, as polyurethane can withstand greater pressure.

[0053] Furthermore, when the drone floats on the water and the power battery 11 is below a preset value (for example, the preset value can be 30%, or if the flight safety requirements are higher, the preset value can be 35% or 40%), the controller 7 controls the first solenoid valve 133 to open and controls the piston engine 8 to start working.

[0054] Furthermore, the bow of hull 1 adopts a streamlined design, which can reduce the wind resistance of the drone.

[0055] Furthermore, such as Figure 3 As shown, the amphibious drone also includes a landing support 14, which is used to support the drone when it lands.

[0056] Furthermore, such as Figure 7 As shown, the amphibious drone also includes GPS15, which is used to detect the drone's location in real time.

[0057] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A dual-purpose (water and air) unmanned aerial vehicle, characterized in that, include: hull; A foldable arm, the first end of which is rotatably connected to the hull; The power unit includes a propeller and a drive motor. The drive motor is fixedly mounted on the second end of the foldable arm, and the propeller is connected to the drive motor in a transmission manner. An external airbag is provided around the hull and partially covers the lower part of the foldable arm. The external airbag is fixed relative to the second end of the foldable arm. An air pump, connected to the outer airbag, is used to inflate the outer airbag with gas. A pressure control unit, comprising a pressure valve disposed on the outer airbag and a pressure sensor inside the outer airbag, wherein the pressure valve is used for overpressure protection; A controller is located inside the hull and is connected to the pressure sensor and the air pump. When the air pump is started, gas enters the outer air bag. After the outer air bag expands, it drives the foldable arm to unfold to the working state. The controller controls the inflation speed and start / stop of the air pump according to the feedback signal of the pressure sensor. After the outer air bag deflates, it contracts and drives the foldable arm to fold.

2. The amphibious unmanned aerial vehicle as described in claim 1, characterized in that, The hull has a first sealed compartment and a second sealed compartment, and the amphibious unmanned aerial vehicle also includes: The piston engine is located within the first sealed enclosure. A generator is installed inside the first sealed enclosure, and the generator is connected to the crankshaft assembly of the piston engine. The power battery is located inside the second sealed enclosure; The power battery and the generator are both electrically connected to the drive motor, and the piston engine and the power battery can provide power to the drive motor independently or jointly. The power output terminal of the generator is also electrically connected to the power input terminal of the power battery, so that the piston engine can charge the power battery through the generator when it is running.

3. The amphibious unmanned aerial vehicle as described in claim 2, characterized in that, The piston engine is a two-stroke direct injection engine, comprising: The combustion chamber is composed of the piston, cylinder, and cylinder head of the piston engine; Fuel supply system, used to supply and inject fuel; An air supply system is used to supply compressed air; A fuel rail is connected to the fuel supply system and the air supply system; The compressed air supplied by the air supply system and the fuel supplied by the fuel supply system are pre-mixed in the fuel rail and then injected into the combustion chamber.

4. The amphibious unmanned aerial vehicle as described in claim 3, characterized in that, The fuel supply system includes fuel injectors, which are connected to the fuel rail; The air supply system includes an air injector and an air pump assembly. The air injector is connected to the fuel rail, and the air pump assembly is driven by the crankshaft assembly of the piston engine to generate the compressed air. The piston engine also includes a chuck nozzle, through which compressed air and fuel are mixed in the fuel rail and then injected into the combustion chamber.

5. The amphibious unmanned aerial vehicle as described in claim 4, characterized in that, The fuel supply system also includes: Mechanical pumps are used to draw fuel from fuel tanks; A fuel filter is connected to the outlet of the mechanical pump; A primary fuel pump, the inlet of which is connected to the fuel filter; A secondary fuel pump, wherein the inlet of the secondary fuel pump is connected to the outlet of the primary fuel pump, and its outlet is connected to the fuel inlet of the fuel rail. The fuel rail is also equipped with a return port, which is connected to the return port of the first-stage fuel pump through a pipeline to form a fuel circuit.

6. The amphibious unmanned aerial vehicle as described in claim 5, characterized in that, The primary fuel pump includes: A thermostatic heater is used to heat the fuel in the pump chamber; Electric pump core, used for primary fuel boosting; Temperature sensor used to monitor fuel temperature; The constant temperature heater and the temperature sensor are both electrically connected to the controller.

7. The amphibious unmanned aerial vehicle as described in claim 4, characterized in that, The amphibious unmanned aerial vehicle also includes an air filter silencer, which is connected to the air inlet of the air pump assembly.

8. The amphibious unmanned aerial vehicle as described in claim 3, characterized in that, Also includes: Spark plugs are installed on the cylinder head; A glow plug is installed on the cylinder head; The preheating plug is electrically connected to the controller.

9. The amphibious unmanned aerial vehicle as described in claim 3, characterized in that, The amphibious unmanned aerial vehicle also includes a sealed air intake and exhaust system, which comprises: The air intake is located on the outer wall of the hull. An air intake channel, one end of which is connected to the air intake port, and the other end of which is connected to the air supply system; A first solenoid valve is disposed on the air intake channel, and the first solenoid valve is electrically connected to the controller; Specifically, when the drone is in air or water mode, the controller controls the first solenoid valve to open; when the drone is in underwater mode, the controller controls the first solenoid valve to close.

10. The amphibious unmanned aerial vehicle as described in claim 9, characterized in that, The sealed intake and exhaust system also includes: A pressure relief valve is disposed between the air intake channel and the first sealed enclosure, and the pressure relief valve is electrically connected to the controller; A second solenoid valve is located at the exhaust port and is electrically connected to the controller. The exhaust port is located on the outer wall of the hull. When the intake manifold pressure reaches a certain threshold, the controller controls the pressure relief valve to open, allowing the gas in the intake manifold to enter the first sealed chamber. The controller also controls the second solenoid valve to open, and the gas cools the piston engine before being discharged from the exhaust port.

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