Float valve for aircraft fuel tank

Abstract

The utility model discloses a kind of float valve for aircraft fuel tank, it is related to aircraft fuel system technical field, to solve the problem of existing float valve trigger reliability low, lack of emergency mechanism and inconvenient maintenance, the technical scheme that it uses is, shell is internally hollow structure, and upper and lower two ends are connected with installation cover and end cover respectively;Shell inside is equipped with float and emergency float, and still install with the first dry spring subassembly and the second dry spring subassembly corresponding to the position of float and emergency float;Magnetic steel is equipped in float and emergency float, when float and emergency float and the first dry spring subassembly and the second dry spring subassembly position correspond, trigger fuel tank full oil signal;Through float to drive valve component to move and close inlet, simultaneously trigger the first dry spring subassembly, output normal full oil signal, when mechanical valve fails, emergency float can trigger the second dry spring tube subassembly, send emergency full oil signal, through electric control to close oil delivery passage, provide double insurance for the closure of pressure refueling.

Description

Technical Field

[0001] This utility model relates to the field of aircraft fuel system technology, specifically to a float valve for aircraft fuel tanks. Background Technology

[0002] Aircraft fuel tanks use float valves installed inside the fuel tanks to control the opening and closing of the fuel filling line, or refueling control valve, during pressurized refueling. Aircraft fuel tanks are highly hazardous; if the pressurized refueling process goes awry, it can lead to fuel leakage and potentially cause a fire. As a crucial control component of the pressurized refueling control system, the float valve requires extremely high reliability. Traditional float valves utilize the buoyancy of a float to overcome the incoming pressure in the fuel line. Once the fuel level reaches a specified height, the float valve controls the refueling line to shut off. Failure of the float valve can result in significant damage to the aircraft. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the existing defects and provide a float valve for aircraft fuel tanks, which can effectively solve the problems in the background art.

[0004] To achieve the above objectives, this utility model discloses a float valve for an aircraft fuel tank. The technical solution includes a mounting cover, a housing, and an end cover. The housing has an internal hollow structure, and the mounting cover and the end cover are respectively connected to the upper and lower ends. The end cap is provided with an oil inlet that communicates with the interior of the housing, and the side wall of the housing is provided with an oil outlet. The housing is equipped with a float and an emergency float, and also has a first reed assembly and a second reed assembly corresponding to the positions of the float and the emergency float. Both the float and the emergency float are equipped with magnets. When the float and the emergency float are positioned corresponding to the first reed assembly and the second reed assembly, they trigger the oil tank full signal and the emergency full signal. The float moves the valve assembly to close the oil inlet, and at the same time triggers the first reed assembly to output a normal full oil signal. When the mechanical valve fails, the emergency float can trigger the second reed assembly to send an emergency full oil signal and at the same time, shut off the oil supply passage through electronic control, providing double insurance for the shutdown of pressure refueling.

[0005] As a preferred technical solution of this utility model, the float is rotatably connected to the housing by a fixing pin. The fixing pin is a T-shaped pin, including a neck and a head. The float is installed on the neck of the fixing pin, and the end of the neck of the fixing pin is also provided with a second washer and a second cotter pin to limit the position of the float. Each component is fixed by standard parts such as washer and cotter pin, which makes disassembly and assembly convenient.

[0006] As a preferred embodiment of this utility model, the top of the oil inlet is provided with a sealing structure to close it, and the bottom is connected to the control valve of the oil tank through an oil pipe.

[0007] As a preferred embodiment of this utility model, the sealing structure includes a valve assembly and a sealing seat. The sealing seat is installed on the top of the oil inlet. The top of the valve assembly passes through the sealing seat and is connected to the float. The bottom of the valve assembly is located at the bottom of the sealing seat. When the float rises, it can drive the valve assembly to move upward and cooperate with the sealing seat to block the oil inlet.

[0008] As a preferred embodiment of the present invention, the top of the valve assembly protrudes from the float and is provided with a first washer and a first cotter pin, and a spring is also provided between the first washer and the float.

[0009] As a preferred embodiment of this utility model, the first reed assembly is installed inside the housing via a guide rod, and the end cap is provided with screws that limit the position of the guide rod.

[0010] As a preferred technical solution of this utility model, the housing is further provided with an installation tube, the second reed assembly is disposed in the installation tube, and the emergency float is slidably connected to the outer wall of the installation tube; the float and the emergency float are respectively installed by a fixing pin and the installation tube, which allows for smooth rotation and sliding, reliable positioning, and strong long-term stability.

[0011] As a preferred embodiment of this utility model, an electrical connector is also installed on the end cover. The electrical connector is connected to an external control circuit and provides power to the first reed assembly and the second reed assembly.

[0012] As a preferred technical solution of this utility model, a pre-inspection connector is also installed on the end cap, and a plug is also provided at the bottom of the pre-inspection connector; The pre-inspection connector is used to test the emergency full-oil function of the pressure refueling system. The pre-inspection connector is connected to a dedicated test oil circuit. After oil is supplied, the emergency function is tested to see if it is normal. When using this device normally, the plug seals the pre-inspection connector, and the pre-inspection connector does not participate in the operation. The electrical connector adopts a standardized interface, which is highly versatile and easy to adapt to the control circuits of different models.

[0013] Compared with the prior art, the beneficial effects of this utility model are: This utility model uses a float to drive the valve assembly to move and shut off the oil inlet, while simultaneously triggering the first reed assembly to output a normal full oil signal. When the mechanical valve fails, the emergency float can trigger the second reed assembly to issue an emergency full oil signal and simultaneously shut off the oil supply path through electronic control, providing double insurance for the shut-off of pressure refueling.

[0014] The float and emergency float are installed by fixing pins and mounting tubes respectively, which are smooth to rotate and slide, reliable to limit, and have strong long-term stability; each component is fixed by standard parts such as gaskets and cotter pins, which are convenient to disassemble and assemble. The pre-inspection connector is used to test the emergency full-oil function of the pressure refueling system. The pre-inspection connector is connected to a dedicated test oil circuit. After oil is supplied, the emergency function is tested to see if it is normal. When using this device normally, the plug seals the pre-inspection connector, and the pre-inspection connector does not participate in the operation. The electrical connector adopts a standardized interface, which is highly versatile and easy to adapt to the control circuits of different models. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a top view of the structure of this utility model; Figure 3 This is a cross-sectional view of the present invention (AA). Figure 4 This is a cross-sectional view of the present invention. Figure 5 This is a CC cross-sectional view of the present invention.

[0016] In the diagram: 1. Mounting cover; 2. Magnet; 3. Guide rod; 4. First reed assembly; 5. Housing; 6. End cap; 7. Screw; 8. Oil outlet; 9. Float; 10. Valve assembly; 11. Oil inlet; 12. Sealing seat; 13. Fixing pin; 14. Spring; 15. First gasket; 16. First cotter pin; 17. Electrical connector; 18. Plug; 19. Pre-inspection connector; 20. Emergency float; 21. Second reed assembly; 22. Mounting tube; 23. Second gasket; 24. Second cotter pin. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example 1

[0018] like Figures 1 to 5 As shown, this utility model discloses a float valve for aircraft fuel tanks, and the technical solution adopted is as follows: It includes a mounting cover 1, a housing 5, and an end cover 6. The housing 5 has an internal hollow structure, and its upper and lower ends are fixedly connected to the mounting cover 1 and the end cover 6, respectively, to form a closed mounting cavity.

[0019] The end cap 6 has an oil inlet 11 that communicates with the inside of the housing 5. The top of the oil inlet 11 has a sealing structure, and the bottom is connected to the control valve of the fuel tank through an oil pipe. The side wall of the housing 5 has an oil outlet 8 for guiding the fuel entering the housing 5 into the fuel tank.

[0020] The housing 5 is equipped with a float 9 and an emergency float 20, and a first reed assembly 4 and a second reed assembly 21 are installed at the corresponding positions. Both the float 9 and the emergency float 20 have built-in magnets 2. When the float 9 or the emergency float 20 rises with the oil level to the preset position, the magnet 2 and the corresponding reed assembly generate magnetic coupling, triggering the oil tank full signal.

[0021] The float 9 is rotatably connected to the housing 5 by a T-shaped fixing pin 13. The float 9 is installed at the neck of the fixing pin 13. The end of the neck is axially limited by the second washer 23 and the second cotter pin 24 to ensure that the float 9 rotates smoothly and does not fall off.

[0022] The sealing structure includes a valve assembly 10 and a sealing seat 12. The sealing seat 12 is fixedly installed on the top of the oil inlet 11. The top of the valve assembly 10 passes through the sealing seat 12 and is connected to the float 9, while the bottom is located below the sealing seat 12. The part of the valve assembly 10 that protrudes from the float 9 is sequentially equipped with a first cotter pin 16, a first gasket 15, and a spring 14. The spring 14 provides preload to ensure the initial fit between the valve assembly 10 and the sealing seat 12. When the float 9 rises, it drives the valve assembly 10 to move upward and fit tightly against the sealing seat 12, thereby achieving reliable sealing of the oil inlet 11.

[0023] The first reed assembly 4 is fixedly installed inside the housing 5 via the guide rod 3. The end cover 6 is provided with screws 7, which are used to limit and fix the installation position of the guide rod 3 to prevent it from moving axially.

[0024] The housing 5 is provided with an installation tube 22, the second reed assembly 21 is built into the installation tube 22, and the emergency float 20 is slidably sleeved on the outer wall of the installation tube 22. The emergency float 20 can rise and fall along the axial direction of the installation tube 22 with the oil level.

[0025] The end cap 6 is also equipped with an electrical connector 17 and a pre-inspection connector 19. The electrical connector 17 is connected to an external control circuit to provide working power to the first reed assembly 4 and the second reed assembly 21, and to transmit a full oil signal. The pre-inspection connector 19 has a plug 18 at the bottom. Opening the plug 18 allows for a pre-inspection of the device's trigger sensitivity and sealing performance.

[0026] The working principle of this utility model: During refueling, fuel enters the interior of the casing 5 through the fuel inlet 11 and then flows into the aircraft fuel tank through the fuel outlet 8, causing the fuel level to gradually rise.

[0027] When the oil level in the tank is not at the normal full level, the float 9 falls freely under the action of gravity, the valve assembly 10 and the sealing seat 12 are in the open state, the first reed assembly 4 does not sense the magnet 2 inside the float 9, and the float 9 does not emit any signal.

[0028] As the oil level rises and reaches the normal full oil level, the float 9 rotates upward around the fixed pin 13. When the oil tank is close to full, the float 9 rises under the action of buoyancy, which drives the valve assembly 10 to rise. The magnet 2 inside the float 9 aligns with the first reed assembly 4, generating magnetic coupling that causes the first reed assembly 4 to actuate and send a full oil signal to the external control circuit. At the same time, the float 9 drives the valve assembly 10 to move upward and fit tightly against the sealing seat 12, blocking the oil inlet 11 and stopping the refueling.

[0029] If the normal shut-off fails, i.e., the float 9 or the valve assembly 10 malfunctions, the oil level continues to rise. When the oil level reaches the emergency full oil level, the emergency float 20 rises under the action of buoyancy. The emergency float 20 slides upward along the mounting pipe 22. When it rises to the preset emergency position, the magnet 2 inside the emergency float 20 generates magnetic coupling with the second reed assembly 21, triggering the emergency full oil signal. The system controls the refueling control valve solenoid valve to be energized, the refueling control valve closes, and refueling stops.

[0030] The pre-inspection connector is used to test the emergency full-oil function of the pressure refueling system. The pre-inspection connector is connected to a dedicated test oil circuit. After oil is supplied, the emergency function is tested to see if it is normal. When using this device normally, the plug will seal the pre-inspection connector, and the pre-inspection connector will not participate in the operation.

[0031] The first reed assembly 4 and the second reed assembly 21 used in this technical solution were purchased from Shaanxi Qunli Chuangda Electronic Technology Co., Ltd., and are products that can be purchased on the market, belonging to the prior art.

[0032] The circuits and mechanical connections involved in this utility model are common practices used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments. They are common knowledge.

[0033] Components not described in detail in this article are existing technologies.

[0034] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A float valve for an aircraft fuel tank, characterized in that: It includes a mounting cover (1), a housing (5) and an end cap (6). The housing (5) has an internal hollow structure and the mounting cover (1) and the end cap (6) are respectively connected to the upper and lower ends. The end cap (6) is provided with an oil inlet (11) that communicates with the inside of the housing (5), and the side wall of the housing (5) is provided with an oil outlet (8). The housing (5) is provided with a float (9) and an emergency float (20) inside, and is also equipped with a first reed assembly (4) and a second reed assembly (21) corresponding to the positions of the float (9) and the emergency float (20). Both the float (9) and the emergency float (20) are equipped with magnets (2). When the float (9) and the emergency float (20) correspond to the positions of the first reed assembly (4) and the second reed assembly (21), they trigger the oil tank full signal and the emergency full signal.

2. The float valve for an aircraft fuel tank according to claim 1, characterized in that: The float (9) is rotatably connected to the housing (5) by a fixing pin (13). The fixing pin (13) is a T-shaped pin, including a neck and a head. The float (9) is installed on the neck of the fixing pin (13), and the end of the neck of the fixing pin (13) is also provided with a second washer (23) and a second cotter pin (24) for limiting the float (9).

3. A float valve for an aircraft fuel tank according to claim 1, characterized in that: The top of the oil inlet (11) is provided with a sealing structure to close it, and the bottom is connected to the control valve of the oil tank through an oil pipe.

4. A float valve for an aircraft fuel tank according to claim 3, characterized in that: The sealing structure includes a valve assembly (10) and a sealing seat (12). The sealing seat (12) is installed on the top of the oil inlet (11). The top of the valve assembly (10) passes through the sealing seat (12) and is connected to the float (9). The bottom of the valve assembly (10) is located at the bottom of the sealing seat (12). When the float (9) floats up, it can drive the valve assembly (10) to move upward and cooperate with the sealing seat (12) to block the oil inlet (11).

5. A float valve for an aircraft fuel tank according to claim 4, characterized in that: The top of the valve assembly (10) protrudes from the float (9) and is provided with a first gasket (15) and a first cotter pin (16), and a spring (14) is also provided between the first gasket (15) and the float (9).

6. A float valve for an aircraft fuel tank according to claim 1, characterized in that: The first reed assembly (4) is installed in the housing (5) via a guide rod (3), and the end cap (6) is provided with a screw (7) that limits the guide rod (3).

7. A float valve for an aircraft fuel tank according to claim 1, characterized in that: The housing (5) is also provided with an installation tube (22), the second reed assembly (21) is located inside the installation tube (22), and the emergency float (20) is slidably connected to the outer wall of the installation tube (22).

8. A float valve for an aircraft fuel tank according to claim 1, characterized in that: An electrical connector (17) is also installed on the end cap (6). The electrical connector (17) is connected to an external control circuit and provides power to the first reed assembly (4) and the second reed assembly (21).

9. A float valve for an aircraft fuel tank according to claim 1, characterized in that: The end cap (6) is also equipped with a pre-inspection connector (19), and the bottom of the pre-inspection connector (19) is also provided with a plug (18).

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