Open type ventilation series oil tank fuel system
By using an open-type ventilated series fuel tank system, which utilizes gravity fuel delivery and a one-way valve design, the problems of high cost, complex control, and poor maneuverability of small UAV fuel systems have been solved, achieving stable fuel supply and efficient fuel utilization, and adapting to complex flight attitudes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YITONG UAV SYST CO LTD
- Filing Date
- 2025-05-22
- Publication Date
- 2026-05-26
AI Technical Summary
Existing drone fueling systems suffer from problems such as high cost, complex control, easy fuel tank deformation, poor maneuverability, and incomplete fuel discharge in small drones, making them particularly unsuitable for high-maneuverability flight.
It adopts an open-type ventilated series fuel tank system, which is connected by ventilated pipelines between the fuel supply tank and the fuel transfer tank. It utilizes gravity fuel transfer and a one-way valve design, combined with a weighted fuel extractor and a grid plate, to ensure a stable fuel supply and maintain fuel suction function under negative overload. The fuel filling and discharging port design is optimized to adapt to complex flight attitudes.
It achieves stable fuel supply without pumps, reduces unusable fuel, improves fuel utilization and flight stability, meets the needs of high-maneuverability flight, and simplifies fuel management and refueling operations.
Smart Images
Figure CN224277566U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of unmanned aerial vehicle (UAV) fuel tank technology, and particularly relates to an open-type ventilated series fuel tank system. Background Technology
[0002] Because unmanned aerial vehicles (UAVs) often perform a series of large maneuvers (high-angle pitching, high-angle diving, high-angle rolling) during flight due to the nature of their missions, the design requirements for the fuel system are very high. The fuel system must reliably and continuously deliver fuel to the engine throughout the entire flight phase.
[0003] A conventional fuel system includes a fuel delivery system, a fuel supply system, a venting system, a measurement system, and a fuel filling and emptying system.
[0004] oil transportation system
[0005] Current fuel systems use a fuel pump to draw fuel from the transfer tank to the supply tank. This method is not suitable for small drones and those with flexible fuel tanks for the following reasons:
[0006] 1. Aviation fuel pumps are relatively expensive, making them a costly option for small drones.
[0007] 2. The large number of control cables and power cables increases the control logic and power requirements;
[0008] 3. A malfunctioning fuel pump can prevent fuel from being delivered to the fuel tank;
[0009] 4. During the oil transfer process, the pressure difference between the inside and outside of the oil tank can easily increase, causing the oil tank to deform.
[0010] fuel supply system
[0011] Current fuel systems use direct-suction fuel pumps, which prevents large maneuvers when fuel levels are low, thus reducing the aircraft's maneuverability.
[0012] Ventilation system
[0013] Current aircraft fuel systems typically use venting tanks, which are connected to the external environment via a vent pipe located outside the aircraft. This design is unsuitable for small unmanned aerial vehicles (UAVs) for the following reasons:
[0014] 1. The venting fuel tank occupies space and cannot be used;
[0015] 2. If fuel gets in, the fuel cannot be reused.
[0016] Fuel filling and draining system
[0017] Currently, aircraft fuel system drain devices are installed at the bottom of the fuel tank. However, since small drones require a small amount of fuel to refuel, this setup prevents the fuel tank from being completely emptied. As a result, the proportion of fuel remaining in the tank increases, affecting fuel quality. Utility Model Content
[0018] In view of the shortcomings of the prior art, the purpose of this utility model is to provide an open-type ventilated series fuel tank system.
[0019] To achieve the above objectives, the technical solution adopted is:
[0020] An open-type vented series fuel tank system includes a fuel supply tank and a fuel delivery tank. The fuel delivery tank has a filler port. A vent pipe connects the upper part of the fuel supply tank and the upper part of the fuel delivery tank. The fuel supply tank and / or the fuel delivery tank are connected to an air vent. The lower end of the fuel supply tank is connected to a fuel supply collection box, and the lower end of the fuel delivery tank is connected to a fuel delivery collection box. The size of the fuel supply collection box is smaller than that of the fuel supply tank, and the size of the fuel delivery collection box is smaller than that of the fuel delivery tank. The smaller size refers to a smaller cross-sectional area. The fuel supply collection box and the fuel delivery collection box are connected by a pipeline. A one-way valve is provided on the pipeline, so that fuel can only flow from the fuel delivery collection box to the fuel supply collection box. A fuel extractor is provided inside the fuel supply collection box. One end of the fuel extractor is connected to the fuel supply pipeline outside the fuel supply collection box, and the other end of the fuel supply pipeline is connected to the engine.
[0021] The beneficial effects of adopting the above technical solution are as follows: the small-sized oil collection box forms an "oil well effect", ensuring that the fuel tank can still collect the remaining fuel when the fuel level is low, significantly reducing the amount of unusable "dead fuel", so that the aircraft can still supply fuel smoothly when performing large maneuvers.
[0022] Based on the above technical solution, the present invention can be further improved as follows:
[0023] Preferably, the oil supply and collection box is provided with a sensor electrical interface, through which a sensor is connected.
[0024] The beneficial effects of adopting the above-mentioned preferred technical solution are as follows: the sensor includes a temperature sensor and a liquid level sensor. The temperature sensor is located in the fuel supply and collection box and is used to monitor the temperature in the fuel supply and collection box. The liquid level sensor is located in the fuel tank and is used to monitor the liquid level in the fuel tank. Real-time monitoring of fuel quantity (such as 20%~80% segments) simplifies UAV fuel quantity management and enables flight planning.
[0025] Preferably, the oil supply and collection box and the oil delivery and collection box are provided with an oil drain port at their bottom ends.
[0026] The advantages of adopting the above-mentioned preferred technical solution are: to maximize the drainage of old oil, reduce dead oil residue, and ensure fuel quality.
[0027] Preferably, the oil transfer collection box is higher than or flush with the oil supply collection box.
[0028] The advantages of adopting the above-mentioned preferred technical solution are: enhancing the efficiency of gravity oil transportation and avoiding fuel stagnation in the oil tank.
[0029] Preferably, two oil tanks are provided.
[0030] The advantages of adopting the above-mentioned preferred technical solutions are: increased fuel capacity and redundancy, adapting to the needs of long-endurance or high-fuel-consumption missions.
[0031] Preferably, the fuel supply line is equipped with a one-way valve, so that fuel can only flow from the fuel supply box to the engine.
[0032] The beneficial effects of adopting the above-mentioned preferred technical solution are: preventing fuel backflow when the engine stops, and ensuring the safety of restarting.
[0033] Preferably, the oil extractor includes a hose, one end of which is connected to the oil supply line, and the other end of which is an oil suction port, and the oil suction port is equipped with a counterweight.
[0034] The beneficial effect of adopting the above-mentioned preferred technical solution is that: under negative overload, the counterweight causes the oil suction port to move with the fuel, ensuring continuous oil intake (such as in a dive maneuver).
[0035] More preferably, the oil supply tank and / or oil transfer tank are provided with a grating plate.
[0036] The advantages of adopting the above-mentioned preferred technical solutions are: suppressing fuel sloshing, maintaining flight stability, and avoiding attitude loss of control.
[0037] Preferably, the top of the oil tank is provided with a groove, the oil filling port is located in the groove, the oil filling port is threadedly connected to an oil filling cap, the upper end of the oil filling cap is flush with the top of the oil tank; similarly, the bottom of the oil tank is provided with a groove, the oil drain port is located in the bottom groove, the oil drain port is threadedly connected to an oil drain cap, the lower end of the oil drain cap is flush with the bottom of the oil tank.
[0038] The advantages of adopting the above-mentioned preferred technical solution are: it facilitates rapid refueling and discharging in the field, reduces the risk of structural damage, and saves space.
[0039] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0040] This invention provides an open-type ventilated series fuel tank system. Through the connection of the upper ventilated pipes between the fuel supply tank and the fuel transfer tank, and the gravity-fed fuel collection box at the bottom, stable fuel supply without a pump is achieved. A one-way valve prevents fuel backflow, a grille suppresses fuel sloshing, and a weighted fuel extractor ensures continuous fuel supply during negative overload maneuvers. The ventilated design, combined with the under-fuselage vent, maintains fuel tank pressure balance, and the recessed refueling and drain ports optimize field refueling and draining efficiency. This system boasts advantages such as simple structure, high reliability, and adaptability to complex flight maneuvers, making it particularly suitable for highly maneuverable unmanned aerial vehicles (UAVs). While eliminating the fuel pump, it solves key technical problems such as fuel delivery, attitude stabilization, and fuel supply under extreme conditions through mechanical innovation.
[0041] 1. The fuel pump design for the fuel tank has been eliminated, and a gravity fuel delivery design has been adopted. During the gravity fuel delivery process, the fuel supply collection box is protected and will not be ruptured due to full fuel. The gravity fuel delivery function is mainly achieved through the fuel delivery pipeline. Both the fuel supply tank and the fuel tank are equipped with flap-type check valves. When the engine fuel pump draws fuel from the fuel supply collection box, the difference in liquid level between the fuel supply tank and the fuel tank (creating a gravity difference) will push the check valve to open, allowing fuel to flow to the fuel supply tank, thus realizing the fuel delivery function.
[0042] 2. By eliminating the need for a vented fuel tank and using a venting pipe for fuel tank ventilation, the space utilization of the fuel system is improved, which is beneficial for increasing the range of small UAVs. The venting pipes are interconnected from the top fuel tanks, and the design of the venting pipe ends fully considers fuel siphon and external fuel cross-contamination, which can effectively prevent fuel from flowing through the venting pipes under various flight attitudes. The vent can be connected to a hose to the windward side of the fuselage. With this design, the fuel tank can obtain a certain amount of ram pressure during high-speed flight, which is beneficial for improving fuel supply efficiency and maintaining the shape of the fuel tank.
[0043] 3. A one-way valve ensures that the fuel in the fuel tank can flow continuously into the fuel supply collection box. During negative overload operation, the fuel in the fuel supply collection box will not flow back to the fuel tank. The fuel inlet at the end of the fuel extractor is equipped with a counterweight. It is a rubber bellows with good flexibility. Its fuel inlet can move with the overload, thus ensuring that the fuel inlet is always submerged in fuel.
[0044] 4. The top of the fuel tank has a recessed design to provide space for the installation of the filler cap. It consists of two parts: a stopcock and a base. The base is glued to the fuel tank and can be unscrewed according to the direction indicator when in use. This design is beneficial for refueling in the field when there is no formal refueling equipment.
[0045] 5. Install measurement sensors in the fuel supply and collection box. The positions of the signal devices are set according to the fuel capacity percentages of 20%, 40%, 60%, and 80%. This helps the crew understand the remaining fuel and plan the flight range. Furthermore, it reduces the need for cumbersome measurement equipment on small UAVs. While achieving the required functionality, it greatly reduces the complexity of the system and achieves a low-cost design. Attached Figure Description
[0046] Figure 1 This is a three-dimensional structural diagram of the open-type ventilated series fuel tank system of this utility model;
[0047] Figure 2 This is a front view of the open-type ventilated series fuel tank system of this utility model;
[0048] Figure 3 for Figure 2 Enlarged view of point A in the middle;
[0049] Figure 4 This is a bottom view of the open-type ventilated series fuel tank system of this utility model;
[0050] The attached diagram is labeled as follows: 1. Oil supply tank; 2. Oil transfer tank; 3. Filling port; 4. Vent pipe; 5. Air vent; 6. Oil transfer check valve; 7. Oil extractor; 8. Oil supply pipe; 81. Oil supply check valve; 9. Sensor electrical interface; 10. Oil drain port; 11. Oil supply collection box; 21. Oil transfer collection box. Detailed Implementation
[0051] The present invention will be described below with reference to examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention.
[0052] In the description of this utility model, it should be noted that the terms "vertical", "up", "down", "horizontal", 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 utility model 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 utility model.
[0053] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0054] Reference Figures 1-3 An open-type vented series fuel tank system includes a fuel supply tank 1 and a fuel delivery tank 2. The fuel delivery tank 2 is equipped with a filler port 3. A vent pipe 4 connects the upper part of the fuel supply tank 1 and the upper part of the fuel delivery tank 2. The fuel supply tank 1 and / or the fuel delivery tank 2 are connected to an air vent 5. A fuel supply and collection box 11 is connected to the lower end of the fuel supply tank 1, and a fuel delivery and collection box 21 is connected to the lower end of the fuel delivery tank 2. The size of the fuel supply and collection box 11 is smaller than that of the fuel supply tank 1. The size of the fuel collection box 21 is smaller than that of the fuel tank 2. The fuel supply collection box 11 and the fuel collection box 21 are connected by a pipeline. The pipeline is equipped with a fuel supply check valve 6, which allows fuel to flow only from the fuel supply collection box 21 to the fuel supply collection box 11. The fuel supply collection box 11 is equipped with a fuel extractor 7. One end of the fuel extractor 7 is connected to the fuel supply pipeline 8 outside the fuel supply collection box 11. The other end of the fuel supply pipeline 8 is connected to the engine.
[0055] In this embodiment, the oil supply and collection box 11 is provided with a sensor electrical interface 9, through which a sensor is connected. The sensor includes a temperature sensor and a liquid level sensor. The temperature sensor is located inside the oil supply and collection box 11 and is used to monitor the temperature inside the oil supply and collection box 11. The liquid level sensor is located inside the oil supply tank 1 and is used to monitor the liquid level inside the oil supply tank 1.
[0056] In this embodiment, the bottom ends of the oil supply and collection box 11 and the oil delivery and collection box 21 are provided with oil outlets 10.
[0057] In this embodiment, two oil tanks 2 are provided, such as... Figure 1 As shown, the two oil tanks 2 are located on both sides of the oil supply tank 1.
[0058] In a preferred embodiment, the oil collection box 21 is higher than or flush with the oil supply collection box 11.
[0059] In a preferred embodiment, the fuel supply line 8 is provided with a fuel supply check valve 81, so that fuel can only flow from the fuel supply collection box 11 to the engine.
[0060] In a preferred embodiment, the oil extractor 7 includes a hose, one end of which is connected to the oil supply line 8, and the other end of which is an oil suction port, and the oil suction port is equipped with a counterweight.
[0061] In a preferred embodiment, the oil supply tank 1 and / or the oil transfer tank 2 are provided with vertically arranged grid plates.
[0062] In this embodiment, the top of the oil tank 2 is provided with a groove, the oil filling port 3 is located in the groove, and the oil filling port 3 is threadedly connected to an oil filling cap. The upper end of the oil filling cap is flush with the top of the oil tank 2. Similarly, the bottom of the oil tank 2 is provided with a groove, the oil drain port 10 is located in the bottom groove, and the oil drain port 10 is threadedly connected to an oil drain cap. The lower end of the oil drain cap is flush with the bottom of the oil tank 2.
[0063] During flight, fuel flows under gravity from the fuel collection box 21 at the bottom of fuel tank 2 to the fuel collection box 11 at the bottom of fuel tank 1 via a one-way valve, forming a stable gravity-driven fuel delivery system. When the engine is running, the fuel extractor 7 (a flexible hose with a counterweight) is always submerged in the fuel in the fuel collection box 11 to ensure continuous fuel supply. During negative overload maneuvers, the counterweight moves with the fuel position to keep the fuel intake submerged, while the one-way valve prevents fuel backflow. The vent pipe 4 connects the upper parts of fuel tank 1 and fuel tank 2, and introduces ram airflow through the vent 5 on the fuselage front to maintain pressure balance inside and outside the fuel tanks. The fuel level is monitored in real time by segmented sensors inside the collection box, while the recessed top refueling port 3 and bottom drain port 10 design facilitates rapid maintenance under field conditions. The entire system achieves pump-free stable fuel supply through mechanical structural innovation, effectively adapting to various flight attitudes of the UAV.
[0064] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. An open vent series fuel tank system comprising a supply tank and a delivery tank, the delivery tank having a filler neck, characterised in that, A vent pipe is connected between the upper part of the fuel supply tank and the upper part of the fuel transfer tank. The fuel supply tank and / or the fuel transfer tank are connected to an air vent. The lower end of the fuel supply tank is connected to a fuel supply collection box, and the lower end of the fuel transfer tank is connected to a fuel transfer collection box. The size of the fuel supply collection box is smaller than that of the fuel supply tank, and the size of the fuel transfer collection box is smaller than that of the fuel transfer tank. The fuel supply collection box and the fuel transfer collection box are connected by a pipeline. A one-way valve is provided on the pipeline so that fuel can only flow from the fuel transfer collection box to the fuel supply collection box. A fuel extractor is provided inside the fuel supply collection box. One end of the fuel extractor is connected to the fuel supply pipeline outside the fuel supply collection box, and the other end of the fuel supply pipeline is connected to the engine.
2. The open vent series tank fuel system of claim 1, wherein, The oil supply and collection box is connected to a sensor.
3. The open vent series tank fuel system of claim 1 wherein, The oil supply and collection box and the oil delivery and collection box are provided with an oil drain port at their bottom ends.
4. The open vent series tank fuel system of claim 1 wherein, The oil transfer collection box is higher than or flush with the oil supply collection box.
5. The open vent series tank fuel system of claim 1 wherein, The oil tank is configured as two.
6. The open vent series tank fuel system of claim 1 wherein, The fuel supply line is equipped with a one-way valve, which ensures that fuel can only flow from the fuel supply box to the engine.
7. The open vent series tank fuel system of claim 1 wherein, The oil extractor includes a hose, one end of which is connected to the oil supply line, and the other end of which is an oil suction port, and the oil suction port is equipped with a counterweight.
8. The open-type vented series fuel tank system according to claim 1, characterized in that, The oil supply tank and / or oil transfer tank are equipped with a grating plate.