Oil level control device based on double-floater design and aircraft fuel system

Abstract

The invention discloses an oil level control device based on double-floater design and an aircraft fuel system, and relates to the technical field of fluid sealing and control. The upper floater cavity is provided with a first oil inlet communicated with the oil inlet cavity; the upper floater is arranged in the upper floater cavity; the upper floater valve is arranged at the first oil inlet and connected with the upper floater; the flat plate valve abuts against the bottom end of the upper floater cavity and communicates with an oil outlet of the oil tank, and the flat plate valve communicates with the oil inlet cavity and moves up and down under the oil pressure of the oil inlet cavity; the lower floater cavity is lower than the upper floater cavity and communicated with the oil tank, and the lower floater cavity is provided with a second oil inlet communicated with the oil inlet cavity; the lower floater is arranged in the lower floater cavity; and the lower floater valve is arranged at the second oil inlet and is connected with the lower floater. Under the condition that the movement stroke of a single floater is not changed, the single-time oil conveying amount of the oil conveying system can be increased, so that more stable oil conveying is achieved, and the phenomenon that the oil conveying system is impacted due to frequent oil conveying is avoided.

Description

Technical Field

[0001] The present invention relates to the field of fluid sealing and control technology, and more specifically to an oil level control device based on a double-float design and an aircraft fuel system. Background Art

[0002] As an important part of the aircraft, the fuel system of medium and large aircraft has a significant impact on flight safety and flight control. As the mission requirements for the long flight time of the aircraft gradually increase, the proportion of the aircraft's fuel load to the total weight of the aircraft gradually increases. Therefore, during the flight, in order to avoid the phenomenon of imbalance of the aircraft's center of gravity due to fuel consumption, it is usually necessary to ensure that the aircraft's fuel load meets the requirements.

[0003] At present, a single-float oil level control device is usually used to control the amount of fuel delivered by the oil delivery system to the fuel tank. Specifically, after the single float drops to a first position along with the oil level, the oil delivery valve opens and the oil delivery system starts to deliver oil. After the single float rises to a second position along with the oil level, the oil delivery valve closes and the oil delivery system stops delivering oil. That is, the movement stroke of the single float is positively correlated with the single oil delivery volume of the oil delivery system.

[0004] The movement stroke of a single float is a fixed value affected by the structure. The single oil delivery volume of the oil delivery system is limited. If the aircraft consumes a lot of fuel, the oil delivery valve needs to be opened frequently to ensure that the amount of fuel in the tank meets the requirements. The frequent opening and closing of the oil delivery valve will cause an impact on the oil delivery system, causing the oil delivery system to easily fail and have a short service life. In addition, the existing improvement plan is to simply increase the movement stroke of the single float, which requires high processing accuracy of the float, and the float is prone to jamming due to unbalanced force during long-distance floating, which is unstable and unreliable.

[0005] In summary, how to increase the single oil delivery volume of the oil delivery system while ensuring that the movement stroke of a single float remains unchanged is a problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide an oil level control device based on a double-float design. The device adopts a double-float design, which can increase the single oil delivery of the oil delivery system while keeping the movement stroke of a single float unchanged, so as to achieve smoother oil delivery and avoid the phenomenon that frequent oil delivery causes impact on the oil delivery system.

[0007] Another object of the present invention is to provide an aircraft fuel system including the above-mentioned oil level control device based on the double-float design.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] An oil level control device based on a double float design comprises:

[0010] The oil inlet cavity is used to connect with the oil delivery system;

[0011] The upper float chamber is provided with a first oil inlet port communicating with the oil inlet chamber;

[0012] An upper float is disposed in the upper float chamber and floats with the oil level in the upper float chamber to have a first position and a second position;

[0013] an upper float valve, disposed at the first oil inlet and connected to the upper float, wherein when the upper float is located at the first position, the upper float valve is opened, and when the upper float is located at the second position, the upper float valve is closed;

[0014] A flat valve is abutted against the oil outlet at the bottom end of the upper float chamber, and the flat valve is connected to the oil inlet chamber and moves up and down under the oil pressure of the oil inlet chamber, and is used to control the connection and disconnection between the oil outlet and the oil tank;

[0015] A lower float chamber is arranged lower than the upper float chamber and is connected to the oil tank, and the lower float chamber is provided with a second oil inlet connected to the oil inlet chamber;

[0016] A lower float is disposed in the lower float chamber and floats along with the oil level in the lower float chamber to have a third position and a fourth position;

[0017] A lower float valve is arranged at the second oil inlet and connected to the lower float. When the lower float is located at the third position, the lower float valve is opened. When the lower float is located at the fourth position, the lower float valve is closed.

[0018] Preferably, the oil inlet chamber is located below the upper float chamber, the first oil inlet port is located at the bottom end of the upper float chamber, and the oil inlet chamber is connected to the first oil inlet port through a vertical first flow channel.

[0019] Preferably, the lower float chamber is located on a side of the upper float chamber away from the oil inlet chamber, the second oil inlet is located at the bottom end of the lower float chamber, and the oil inlet chamber is connected to the second oil inlet through a horizontal third flow channel.

[0020] Preferably, the third flow channel branches out into a vertical second flow channel connected to the flat valve.

[0021] Preferably, the upper float valve comprises an upper valve seat and an upper piston rod assembly, the upper valve seat is arranged at the inner bottom end of the upper float cavity and its valve cavity is connected to the first oil inlet, and the bottom of the upper piston rod assembly can be moved up and down and inserted into the valve cavity of the upper valve seat.

[0022] Preferably, the upper float includes an upper float body and an upper float rod, the upper float body is sleeved on one end of the upper float rod, the other end of the upper float rod is connected to the top of the upper piston rod assembly and extends to be hinged to an upper hinge seat, and the upper hinge seat is arranged on the side of the upper valve seat away from the upper float body.

[0023] Preferably, the flat valve includes a middle valve seat, a flat plate and a spring. The middle valve seat is arranged directly below the oil outlet and is adjacent to the oil inlet chamber in the vertical direction. The bottom end of the flat plate moves up and down and is inserted in the valve chamber of the middle valve seat, and the top end is connected to the oil outlet through the spring.

[0024] Preferably, the bottom end of the lower float chamber is an open end for communicating with the oil tank, and the second oil inlet is located at the open end;

[0025] The lower float valve includes a lower valve seat and a lower piston rod assembly. The lower valve seat is located at the opening end and is integrally connected to the middle valve seat. The valve cavity of the lower valve seat is connected to the second oil inlet. The bottom of the lower piston rod assembly can be moved up and down and inserted into the valve cavity of the lower valve seat.

[0026] Preferably, the lower float includes a lower float body and a lower float rod, the lower float body is sleeved on one end of the lower float rod, the other end of the lower float rod is connected to the top of the lower piston rod assembly and extends to be hinged to a lower hinge seat, and the lower hinge seat is arranged on the side of the lower valve seat away from the lower float body.

[0027] An aircraft fuel system comprises any one of the above-mentioned oil level control devices based on a double-float design, an oil delivery system and a fuel tank.

[0028] The oil level control device based on the double float design provided by the present invention is used to control the fuel loading amount of the fuel tank in the aircraft fuel system to meet the requirements. The specific use process is as follows:

[0029] When the oil level in the fuel tank is lower than the lower float, the upper float has sunk to the first position, and the lower float will also sink to the third position. Both are in a falling state. Therefore, the upper float valve and the lower float valve are both in an open state, and the oil delivery system supplies oil to the oil inlet chamber, and the fuel flows to the upper float chamber and the lower float chamber through the oil inlet chamber. At this time, the oil inlet chamber is in a low-pressure state, and the flat valve is not pressurized and remains open, and the upper and lower float chambers simultaneously deliver oil to the fuel tank.

[0030] When the oil level in the fuel tank rises and contacts the lower float, the lower float rises to the fourth position along with the oil level, the lower float valve closes, the upper float valve and the flat valve remain in the open state, and the oil delivery system delivers oil to the upper float chamber through the oil inlet chamber, and the fuel then flows into the fuel tank through the oil outlet of the upper float chamber.

[0031] When the oil level in the fuel tank continues to rise and contacts the upper float, the upper float floats to the second position with the oil level, and the upper float valve closes. At this time, the fuel in the oil inlet chamber cannot flow into the upper and lower float chambers, and the oil inlet chamber is in a high-pressure state. The flat valve is pressed up and presses against the oil outlet of the upper float chamber, so that the fuel cannot flow into the fuel tank, the oil level in the fuel tank no longer rises, the fuel loading capacity in the fuel tank reaches the requirement, and the oil delivery system stops working.

[0032] As the engine consumes fuel, the oil level in the fuel tank gradually drops below the flat valve. During this process, since the upper float chamber has been disconnected from the fuel tank through the flat valve during the previous oil transfer process, the fuel in the upper float chamber cannot flow into the fuel tank. The oil level in the upper float chamber does not drop as the oil level in the fuel tank drops. The upper float is always in a floating state, and the upper float valve is always in a closed state, thereby maintaining the high pressure in the fuel inlet chamber and keeping the flat valve closed under pressure. Therefore, the oil level in the upper float chamber is decoupled from the oil level in the fuel tank, that is, the lowering process of the upper float is decoupled from the oil level in the fuel tank.

[0033] As the engine continues to consume fuel, the oil level in the fuel tank gradually drops below the lower float, and the lower float sinks to the third position along with the oil level. The lower float valve opens, the oil inlet chamber is depressurized, and the fuel in the oil inlet chamber flows into the lower float chamber, and the fuel then flows into the fuel tank through the lower float chamber. As a result, the flat valve is not pressurized and remains open, so that the fuel in the upper float chamber flows from the oil outlet to the fuel tank, and the upper float sinks to the second position along with the oil level in the upper float chamber, and the upper float valve opens. Then, since the oil inlet chamber is in a low-pressure state, the oil delivery system starts working again to supply oil to the fuel tank.

[0034] Such cycle can realize the fuel tank fuel loading control.

[0035] In summary, the oil level control device based on the double float design provided by the present invention has the following beneficial effects:

[0036] (1) The upper float descending process is decoupled from the oil level in the oil tank, so that the upper float is used to control the end of oil delivery, and the lower float is used to control the start of oil delivery. This increases the distance between the start and end oil delivery levels, thereby increasing the single oil delivery volume of the oil delivery system and avoiding the impact of frequent oil delivery on the oil delivery system.

[0037] (2) The double float design can avoid the phenomenon of easy jamming caused by increasing the movement stroke of a single float, which is beneficial to improving the stability and reliability of the device in controlling the oil transfer process.

[0038] (3) Increasing the single oil delivery volume of the oil delivery system will make the single oil delivery time of the oil delivery system suitable for multi-tank oil delivery control, so that the total oil delivery volume of the oil delivery system is basically not affected by the difference in oil delivery start-up speed of different tanks, so as to meet the oil delivery volume requirements of different tanks.

[0039] In summary, the oil level control device based on the double-float design provided by the present invention can increase the single oil delivery volume of the oil delivery system while keeping the movement stroke of a single float unchanged, so as to achieve smoother oil delivery and avoid the impact of frequent oil delivery on the oil delivery system, thereby improving the oil delivery stability, reliability and service life of the oil delivery system, thereby ensuring the safety and reliability of the aircraft fuel system when the aircraft is flying. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0041] Figure 1 This is a cross-sectional view of an oil level control device based on a double-float design provided by the present invention.

[0042] Reference numerals:

[0043] 1- oil inlet chamber; 2- upper float chamber; 3- upper float; 4- upper float valve; 5- flat valve; 6- lower float chamber; 7- lower float; 8- lower float valve;

[0044] 31-upper float body; 32-upper float rod;

[0045] 41-upper valve seat; 42-upper piston rod assembly; 43-upper hinge seat;

[0046] 51-middle valve seat; 52-plate; 53-spring;

[0047] 71-lower float body; 72-lower float rod;

[0048] 81-lower valve seat; 82-lower piston rod assembly; 83-lower hinge seat;

[0049] I-first flow channel; II-second flow channel; III-third flow channel. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] The core of the present invention is to provide an oil level control device based on a double-float design. The device adopts a double-float design, which can increase the single oil delivery volume of the oil delivery system while keeping the movement stroke of a single float unchanged, so as to achieve smoother oil delivery and avoid the phenomenon that frequent oil delivery causes impact on the oil delivery system.

[0052] Another core of the present invention is to provide an aircraft fuel system including the above-mentioned oil level control device based on the double float design.

[0053] It should be noted that in this embodiment, the directions or positional relationships indicated by "upper", "lower", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present application. In addition, "first", "second", "third", and "fourth" are only used to describe the effect, and cannot be understood as indicating or implying relative importance.

[0054] Please refer to Figure 1 The present invention provides an oil level control device based on a double float design, comprising an oil inlet chamber 1, an upper float chamber 2, an upper float 3, an upper float valve 4, a flat valve 5, a lower float chamber 6, a lower float 7 and a lower float valve 8.

[0055] The oil inlet chamber 1 is used to connect to the oil delivery system.

[0056] Specifically, the oil delivery system delivers oil to the upper float chamber 2 and the lower float chamber 6 through the oil inlet chamber 1 to supply oil to the oil tank.

[0057] Regarding the start and stop control of the oil delivery system, optionally, a liquid level sensor for detecting the oil level in the oil tank is provided in the oil tank, and a pressure sensor for detecting the pressure of the oil inlet chamber 1 is provided in the liquid inlet chamber, and the liquid level sensor, the pressure sensor, and the oil delivery system are all connected to the controller by signals. In this way, when the oil level in the oil tank reaches the preset oil level, it means that the oil tank loading volume meets the requirements at this time, and the liquid level sensor sends a full load signal to the controller, and the controller shuts down the oil delivery system; when the pressure in the oil inlet chamber 1 is lower than the preset pressure value, it means that the oil inlet chamber 1 is in a pressure relief state, and the pressure sensor sends an oil delivery signal to the controller, and the controller starts the oil delivery system, thereby accurately controlling the start and stop of the oil delivery system. In addition, the single working time of the oil delivery system can also be set according to the height distance between the upper float 3 and the lower float 7, that is, according to the single oil delivery volume.

[0058] The upper float chamber 2 is provided with a first oil inlet port connected to the oil inlet chamber 1 .

[0059] Specifically, the first oil inlet can be connected to the oil inlet chamber 1 through the first flow channel I, so that the oil delivery system delivers fuel to the oil inlet chamber 1, and the fuel then flows through the first flow channel I and the first oil inlet into the upper float chamber 2.

[0060] The upper float 3 is disposed in the upper float chamber 2 and floats along with the oil level in the upper float chamber 2 to have a first position and a second position.

[0061] Specifically, the upper float 3 is generally composed of an upper float body 31 and an upper float rod 32. The upper float body 31 will float up as the oil level in the upper float chamber 2 rises, and drive the upper float rod 32 down. Similarly, it will sink as the oil level in the upper float chamber 2 drops, and drive the upper float rod 32 up. The specific structures of the upper float body 31 and the upper float rod 32 can refer to the prior art, which is not the focus of the present invention and will not be described in detail herein.

[0062] The upper float valve 4 is arranged at the first oil inlet and connected to the upper float 3. When the upper float 3 is located at the first position, the upper float valve 4 is opened. When the upper float 3 is located at the second position, the upper float valve 4 is closed.

[0063] Specifically, the upper float valve 4 is a valve body structure that controls the on-off of the first oil inlet, and the valve core of the upper float valve 4 is connected to the upper float body 31 through the upper float rod 32. In this way, the upper float body 31 sinks to the first position, and the valve core of the upper float valve 4 is pulled up by the upper float rod 32, and the upper float valve 4 is opened. The upper float body 31 floats to the second position, and the valve core of the upper float valve 4 is pressed down by the upper float rod 32 to move down, and the upper float valve 4 is closed.

[0064] Therefore, it is not difficult to understand that the upper float 3 floats up as the oil level in the upper float chamber 2 rises, which will press the valve core of the upper float valve 4 downward until the upper float valve 4 is closed; the upper float 3 also sinks as the oil level in the upper float chamber 2 drops, which will pull the valve core of the upper float valve 4 upward until the upper float valve 4 is opened.

[0065] The flat valve 5 abuts against the oil outlet at the bottom end of the upper float chamber 2, and the flat valve 5 is connected to the oil inlet chamber 1 and moves up and down under the oil pressure of the oil inlet chamber 1 to control the connection and disconnection of the oil outlet and the oil tank.

[0066] Specifically, the flat valve 5 is a flat 52 valve body structure. The upper float chamber 2 is connected to the oil tank through the oil outlet at its bottom. The flat valve 5 is set at the oil outlet, which can control the connection and disconnection between the oil outlet and the oil tank, that is, control whether the upper float chamber 2 is connected to the oil tank. In addition, it should be noted that the flat valve 5 is connected to the oil inlet chamber 1 through the second flow channel II, and the fuel in the oil inlet chamber 1 can flow to the flat valve 5 through the second flow channel II. When the oil inlet chamber 1 is in a high-pressure state, it means that the fuel in the oil inlet chamber 1 cannot flow into the upper float chamber 2 and the lower float chamber 6. The flat valve 5 is pressed and moves up to block the oil outlet of the upper float chamber 2 to disconnect the upper float chamber 2 from the oil tank; when the oil inlet chamber 1 is in a low-pressure state, it means that the fuel in the oil inlet chamber 1 can flow into the upper float chamber 2 or the lower float chamber 6. The flat valve 5 is not pressed and moves down to open the oil outlet of the upper float chamber 2 to connect the upper float chamber 2 with the oil tank.

[0067] The lower float chamber 6 is arranged lower than the upper float chamber 2 and is connected to the oil tank, and the lower float chamber 6 is provided with a second oil inlet connected to the oil inlet chamber 1 .

[0068] Specifically, the upper float chamber 2 is set lower than the upper float chamber 2, so that the upper float 3 and the lower float 7 form a height difference to achieve oil level control in the fuel tank. The lower float chamber 6 is connected to the fuel tank. According to the principle of liquid static balance, the oil level in the lower float chamber 6 is the oil level in the fuel tank. In addition, the lower float chamber 6 can be connected to the oil inlet chamber 1 through the third flow channel III. In this way, the oil delivery system delivers fuel to the oil inlet chamber 1, and the fuel then flows into the lower float chamber 6 through the third flow channel III and the second oil inlet, that is, into the fuel tank.

[0069] Preferably, the upper float chamber 2 and the lower float chamber 6 are sequentially placed in the oil tank from top to bottom. In this way, the upper float chamber 2 is connected and disconnected with the oil tank through the flat valve 5, and the bottom end of the lower float chamber 6 is connected with the oil tank, so as to avoid the height difference between the upper and lower float chambers 6 and the oil tank, which affects the oil supply efficiency of the oil tank and generates a large impact force on the oil tank.

[0070] The lower float 7 is disposed in the lower float chamber 6 and floats along with the oil level in the lower float chamber 6 to have a third position and a fourth position.

[0071] Specifically, the lower float 7 is generally composed of a lower float body 71 and a lower float rod 72. The lower float body 71 will float up as the oil level in the lower float chamber 6 rises, and drive the lower float rod 72 down. Similarly, it will sink as the oil level in the lower float chamber 6 drops, and drive the lower float rod 72 up. The specific structures of the lower float body 71 and the lower float rod 72 can refer to the prior art, which is not the focus of the present invention and will not be described in detail herein.

[0072] The lower float valve 8 is arranged at the second oil inlet and connected to the lower float 7. When the lower float 7 is located at the third position, the lower float valve 8 is opened. When the lower float 7 is located at the fourth position, the lower float valve 8 is closed.

[0073] It should be noted that the specific matching and connecting manner of the lower float valve 8 and the lower float 7 can refer to the specific matching and connecting manner of the upper float valve 4 and the upper float 3, which will not be repeated. Therefore, it is not difficult to understand that the lower float 7 floats up with the rise of the oil level in the lower float chamber 6, which will press down the valve core of the lower float valve 8 to move downward until the lower float valve 8 is closed; the lower float 7 also sinks with the drop of the oil level in the lower float chamber 6, which will pull the valve core of the lower float valve 8 to move upward until the lower float valve 8 is opened.

[0074] Based on the above examples, please refer to Figure 1 The oil inlet chamber 1 is located below the upper float chamber 2, the first oil inlet port is located at the bottom end of the upper float chamber 2, and the oil inlet chamber 1 is connected to the first oil inlet port through a vertical first flow channel I.

[0075] It can be understood that the first oil inlet is arranged at the bottom end of the upper float chamber 2, so that the fuel is injected from the bottom of the upper float chamber 2, and the upper float chamber 2 can be filled more evenly to avoid the fuel from forming vortices or bubbles in the upper float chamber 2, and the fuel can flow into the fuel tank more conveniently through the oil outlet, which is conducive to improving the oil delivery efficiency. Furthermore, the use of a vertical first flow channel I to connect the oil inlet chamber 1 and the upper float chamber 2 can reduce the fuel delivery stroke and further improve the oil delivery efficiency.

[0076] Based on the above examples, please refer to Figure 1 The lower float chamber 6 is located on the side of the upper float chamber 2 away from the oil inlet chamber 1, the second oil inlet is located at the bottom end of the lower float chamber 6, and the oil inlet chamber 1 is connected to the second oil inlet through a horizontal third flow channel III.

[0077] It can be understood that the lower float chamber 6 is located beside the upper float chamber 2, making the device structure more compact. The lower float chamber 6 is arranged away from the oil inlet chamber 1, and the flat valve 5 can be arranged horizontally between the oil inlet chamber 1 and the lower float chamber 6, thereby facilitating the oil inlet chamber 1 to transport oil to the lower float valve 8 and the flat valve 5. In addition, the second oil inlet is arranged at the bottom end of the lower float chamber 6 and connected to the oil inlet chamber 1 through the vertical third flow channel III, which can also prevent the fuel from forming vortices or bubbles in the lower float chamber 6 and improve the oil transportation efficiency.

[0078] Based on the above examples, please refer to Figure 1 The third flow channel III branches out into a vertical second flow channel II which is connected to the flat valve 5.

[0079] It can be understood that the oil inlet chamber 1 is connected to the second oil inlet port through the third flow channel III, and the third flow channel III branches out a vertical second flow channel II corresponding to the position of the flat valve 5 to connect to the flat valve 5. In this way, the oil inlet chamber 1 can simultaneously transport oil to the lower float valve 8 and the flat valve 5 through the integrally formed flow channel, which can not only improve the oil transport efficiency, but also save the layout space of the second and third flow channels.

[0080] Based on the above examples, please refer to Figure 1 The upper float valve 4 includes an upper valve seat 41 and an upper piston rod assembly 42. The upper valve seat 41 is arranged at the inner bottom end of the upper float chamber 2 and its valve chamber is connected to the first oil inlet. The bottom of the upper piston rod assembly 42 can be moved up and down and inserted into the valve chamber of the upper valve seat 41.

[0081] Specifically, the upper valve seat 41 is arranged on the bottom plate inside the upper float chamber 2, and the upper piston rod assembly 42 is generally composed of an upper guide rod and an upper piston connected to each other, which are arranged from top to bottom. The upper piston is inserted into the valve chamber of the upper valve seat 41, and the valve chamber is connected to the first oil inlet. The upper guide rod is connected to the upper float rod 32 in the upper float 3. In this way, the upper float 3 floats up, and the upper guide rod pushes the upper piston down until the first oil inlet is blocked, so that the upper float valve 4 is closed; the upper float 3 sinks, and the upper guide rod is pulled up, and the upper guide rod pulls the upper piston up until the first oil inlet is opened, so that the upper float valve 4 is opened.

[0082] Based on the above examples, please refer to Figure 1 The upper float 3 includes an upper float body 31 and an upper float rod 32. The upper float body 31 is sleeved on one end of the upper float rod 32. The other end of the upper float rod 32 is connected to the top of the upper piston rod assembly 42 and extends to be hinged to the upper hinge seat 43. The upper hinge seat 43 is arranged on the side of the upper valve seat 41 away from the upper float body 31. Therefore, the upper float 3 adopts a single rocker arm float structure, and the upper float rod 32 is hinged to the upper valve seat 41, so that the upper float rod 32 rotates around the upper valve seat 41, so that the upper float body 31 moves smoothly, thereby ensuring that the upper float 3 floats up and down smoothly with the oil level in the upper float chamber 2.

[0083] Based on the above examples, please refer to Figure 1 The flat valve 5 includes a middle valve seat 51, a flat plate 52 and a spring 53. The middle valve seat 51 is arranged directly below the oil outlet and adjacent to the oil inlet chamber 1 in the vertical direction. The bottom end of the flat plate 52 moves up and down and is inserted in the valve chamber of the middle valve seat 51, and the top end is connected to the oil outlet through the spring 53.

[0084] It is understandable that the middle valve seat 51 is arranged directly below the oil outlet to ensure that the flat plate 52 moves upward along the valve cavity of the middle valve seat 51 to block the oil outlet. The middle valve seat 51 is adjacent to the oil inlet cavity 1 in the vertical direction (i.e., in the height direction), which can reduce the flow stroke of the fuel in the second flow channel II, so as to quickly press the flat plate 52 to block the oil outlet, thereby quickly stopping the oil supply to the fuel tank, thereby avoiding the situation where the oil outlet is blocked slowly and the fuel tank is overloaded.

[0085] For further information, please refer to Figure 1 A spring 53 is arranged between the flat plate 52 and the oil outlet. Thus, when the oil inlet chamber 1 is in a high pressure state, the fuel in the oil inlet chamber 1 presses the flat plate 52, and the flat plate 52 moves upward to compress the spring 53. When the oil inlet chamber 1 is in a low pressure state, the flat plate 52 is not compressed, and the elastic restoring force of the spring 53 is utilized to make the flat plate 52 move downward quickly to open the oil outlet, thereby realizing the rapid oil delivery from the upper float chamber 2 to the oil tank, further improving the oil delivery efficiency.

[0086] Based on the above examples, please refer to Figure 1 The bottom end of the lower float chamber 6 is an open end for connecting to the oil tank, and the second oil inlet is located at the open end; the lower float valve 8 includes a lower valve seat 81 and a lower piston rod assembly 82, the lower valve seat 81 is located at the open end and is connected to the middle valve seat 51 as a whole, and the valve chamber of the lower valve seat 81 is connected to the second oil inlet, and the bottom of the lower piston rod assembly 82 can be moved up and down and inserted into the valve chamber of the lower valve seat 81.

[0087] Specifically, the bottom end of the lower float chamber 6 is set as an open end, which greatly improves the oil delivery efficiency of the lower float chamber 6 to the oil tank. The lower valve seat 81 and the middle valve seat 51 are both arranged on the same mounting seat, so that the lower valve seat 81 and the middle valve seat 51 are connected as a whole, which is not only convenient for installation and arrangement, but also improves the structural stability of the middle and lower valve seats 81. In addition, the lower piston rod assembly 82 is generally composed of a lower guide rod and a lower piston that are connected to each other. The two are arranged from top to bottom. The lower piston is inserted into the valve cavity of the lower valve seat 81, and this valve cavity is connected to the second oil inlet. The lower guide rod is connected to the lower float rod 72 in the lower float 7. In this way, the lower float 7 floats up, and the lower guide rod can be pressed down, and the lower guide rod pushes the lower piston down until the second oil inlet is blocked, so that the lower float valve 8 is closed; the lower float 7 sinks, and the lower guide rod can be pulled up, and the lower guide rod pulls the lower piston up until the second oil inlet is opened, so that the lower float valve 8 is opened.

[0088] Based on the above examples, please refer to Figure 1The lower float 7 includes a lower float body 71 and a lower float rod 72. The lower float body 71 is sleeved on one end of the lower float rod 72. The other end of the lower float rod 72 is connected to the top of the lower piston rod assembly 82 and extends to be hinged to the lower hinge seat 83. The lower hinge seat 83 is arranged on the side of the lower valve seat 81 away from the lower float body 71. Therefore, the lower float 7 adopts a single rocker arm float structure, and the lower float rod 72 is hinged to the lower valve seat 81, so that the lower float rod 72 rotates around the lower valve seat 81, so that the lower float body 71 moves smoothly, thereby ensuring that the lower float 7 floats up and down smoothly with the oil level in the lower float chamber 6.

[0089] In summary, the oil level control device based on the double-float design provided by the present invention has the following advantages compared with the existing single-float oil level control device:

[0090] First, the double-float design increases the distance between the start and end of oil delivery, thereby increasing the single oil delivery volume of the oil delivery system and avoiding the impact of frequent oil delivery on the oil delivery system.

[0091] Second, it can avoid the phenomenon of easy jamming caused by increasing the movement stroke of a single float, which is beneficial to improving the stability and reliability of the device controlling the oil delivery process and achieving smoother oil delivery of the oil delivery system.

[0092] Third, increasing the single oil delivery volume of the oil delivery system will increase the single oil delivery time of the oil delivery system, which has obvious advantages for simultaneous oil delivery in multiple tanks, so that the total oil delivery volume of the oil delivery system is basically not affected by the difference in oil delivery start-up speed of different tanks, so as to meet the oil delivery volume requirements of different tanks.

[0093] Fourth, the single rocker arm float structure is adopted. Compared with the jet type oil level control device, it is not only reliable and simple in structure, but also can avoid the situation where the jet pipe mouth is blocked and the oil delivery failure occurs, thereby improving the stability and reliability of the device in controlling the oil delivery process.

[0094] The present invention also provides an aircraft fuel system, including the oil level control device based on the double float design disclosed in the above embodiment, the oil transfer system and the fuel tank. For the structures of other parts of the aircraft fuel system, please refer to the prior art and will not be described in detail herein.

[0095] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.

[0096] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0097] The above is a detailed introduction to an oil level control device and an aircraft fuel system based on a double float design provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An oil level control device based on a double float design, characterized in that: include: An oil inlet chamber (1) for connecting to an oil delivery system; The upper float chamber (2) is provided with a first oil inlet port connected to the oil inlet chamber (1); An upper float (3) is arranged in the upper float chamber (2) and floats along with the oil surface in the upper float chamber (2) to have a first position and a second position; an upper float valve (4) disposed at the first oil inlet and connected to the upper float (3); when the upper float (3) is located at the first position, the upper float valve (4) is opened; and when the upper float (3) is located at the second position, the upper float valve (4) is closed; A flat valve (5) is abutted against the oil outlet at the bottom end of the upper float chamber (2), and the flat valve (5) is connected to the oil inlet chamber (1) and moves up and down under the oil pressure of the oil inlet chamber (1), and is used to control the connection and disconnection between the oil outlet and the oil tank; A lower float chamber (6) is arranged lower than the upper float chamber (2) and is connected to the oil tank, and the lower float chamber (6) is provided with a second oil inlet port connected to the oil inlet chamber (1); A lower float (7) is disposed in the lower float chamber (6) and floats along with the oil level in the lower float chamber (6) to have a third position and a fourth position; A lower float valve (8) is arranged at the second oil inlet and connected to the lower float (7); when the lower float (7) is located at the third position, the lower float valve (8) is opened; when the lower float (7) is located at the fourth position, the lower float valve (8) is closed.

2. The oil level control device based on double float design according to claim 1 is characterized in that: The oil inlet chamber (1) is located below the upper float chamber (2), the first oil inlet port is located at the bottom end of the upper float chamber (2), and the oil inlet chamber (1) is connected to the first oil inlet port via a vertical first flow channel (I).

3. The oil level control device based on double float design according to claim 2 is characterized in that: The lower float chamber (6) is located on a side of the upper float chamber (2) away from the oil inlet chamber (1); the second oil inlet port is located at the bottom end of the lower float chamber (6); and the oil inlet chamber (1) is connected to the second oil inlet port via a horizontal third flow channel (III).

4. The oil level control device based on double float design according to claim 3 is characterized in that: The third flow channel (III) branches into a vertical second flow channel (II) which is connected to the flat valve (5).

5. The oil level control device based on double float design according to any one of claims 1 to 4, characterized in that: The upper float valve (4) comprises an upper valve seat (41) and an upper piston rod assembly (42); the upper valve seat (41) is arranged at the inner bottom end of the upper float chamber (2) and its valve chamber is connected to the first oil inlet; the bottom of the upper piston rod assembly (42) is inserted into the valve chamber of the upper valve seat (41) so as to be movable up and down.

6. The oil level control device based on double float design according to claim 5 is characterized in that: The upper float (3) comprises an upper float body (31) and an upper float rod (32); the upper float body (31) is sleeved on one end of the upper float rod (32); the other end of the upper float rod (32) is connected to the top of the upper piston rod assembly (42) and extends to be hinged to an upper hinge seat (43); the upper hinge seat (43) is arranged on a side of the upper valve seat (41) away from the upper float body (31).

7. The oil level control device based on double float design according to any one of claims 1 to 4, characterized in that: The flat valve (5) comprises a middle valve seat (51), a flat plate (52) and a spring (53); the middle valve seat (51) is arranged directly below the oil outlet and adjacent to the oil inlet chamber (1) in the vertical direction; the bottom end of the flat plate (52) is inserted into the valve chamber of the middle valve seat (51) so as to move up and down, and the top end is connected to the oil outlet via the spring (53).

8. The oil level control device based on double float design according to claim 7 is characterized in that: The bottom end of the lower float chamber (6) is an open end for communicating with the oil tank, and the second oil inlet is located at the open end; The lower float valve (8) comprises a lower valve seat (81) and a lower piston rod assembly (82); the lower valve seat (81) is located at the opening end and is integrally connected to the middle valve seat (51); the valve cavity of the lower valve seat (81) is connected to the second oil inlet; the bottom of the lower piston rod assembly (82) is inserted into the valve cavity of the lower valve seat (81) so as to be movable up and down.

9. The oil level control device based on double float design according to claim 8, characterized in that: The lower float (7) comprises a lower float body (71) and a lower float rod (72); the lower float body (71) is sleeved on one end of the lower float rod (72); the other end of the lower float rod (72) is connected to the top of the lower piston rod assembly (82) and extends to be hinged to a lower hinge seat (83); the lower hinge seat (83) is arranged on a side of the lower valve seat (81) away from the lower float body (71).

10. An aircraft fuel system, characterized in that: It comprises an oil level control device based on a double float design, an oil delivery system and an oil tank as described in any one of claims 1 to 9 above.

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