Mechanical oil transportation cut-off control valve for aircraft fuel system
By designing a mechanical fuel cut-off control valve that links a float valve and a piston, the problem of fuel spillage caused by jamming or wear failure of the float-type mechanical cut-off valve was solved, achieving emergency cut-off and improving the system's safety and ability to cope with abnormal operating conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN WOXIANG AVIATION TECH CO LTD
- Filing Date
- 2026-04-09
- Publication Date
- 2026-05-12
AI Technical Summary
Existing float-type mechanical shut-off valves operate under high dependence on the liquid level, and are prone to failure due to mechanical jamming or wear, leading to fuel spillage. Furthermore, they cannot cut off the fuel supply path in advance, posing a safety hazard.
A mechanical oil supply shut-off control valve was designed, comprising a float control component and an oil supply control component. The shut-off is achieved by the linkage between the float valve and the piston, utilizing the buoyancy of the liquid surface and the oil pressure. In the event of failure of the float mechanism, oil can be supplied through the oil supply pipe to lift the piston and achieve emergency shut-off.
This improves system safety, enabling timely disconnection of the fuel supply path in case of float mechanism failure, reducing the risk of fuel spillage, and enhancing the ability to cope with abnormal operating conditions.
Smart Images
Figure CN122014897A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aircraft fuel system technology, and specifically relates to a mechanical fuel supply cut-off control valve for aircraft fuel systems. Background Technology
[0002] In aircraft fuel systems, the pressure refueling subsystem is a key component for achieving rapid and efficient refueling operations. During the fuel transfer process, when the fuel level in the tank reaches a preset height, the fuel transfer valve must be shut off promptly to prevent fuel spillage or system overpressure.
[0003] Currently, fuel cut-off control mainly relies on float-type mechanical control. Existing float-type mechanical cut-off valves utilize the rise of the fuel level to cause the float to rise, and a mechanical linkage mechanism drives the float valve to close, thereby cutting off the fuel supply. This method is simple in structure and highly reliable, and is widely used in various aircraft fuel systems. However, its cut-off action is entirely dependent on the fuel level. If the float mechanism fails due to mechanical jamming, wear, or other reasons, it cannot close the fuel supply valve in time, which may lead to fuel spillage and pose a safety hazard. Furthermore, existing cut-off valves cannot perform emergency operations to cut off the fuel supply in advance. Summary of the Invention
[0004] To address the aforementioned problems in the prior art, this invention provides a mechanical fuel supply cut-off control valve for aircraft fuel systems. The technical problem to be solved by this invention is achieved through the following technical solution: The present invention provides a mechanical fuel supply cut-off control valve for an aircraft fuel system, including a housing and a float control component and a fuel supply control component installed in the housing. The housing is also provided with a valve seat, and the valve seat and the housing together form a fuel supply chamber. The valve seat is provided with a float oil passage and a piston oil passage, and both the float oil passage and the piston oil passage are connected to the fuel supply chamber. The float control assembly includes a float valve, a float support, and a float element. One side of the float support is rotatably connected to the valve seat, and the other side is fixedly connected to the float element. One end of the float valve extends into the float oil passage, and the other end extends through the float oil passage and is connected to the float support. The oil delivery control assembly includes a piston and an oil delivery pipe. One end of the piston extends into the piston oil passage, and the other end extends through the piston oil passage and is connected to the float support. The piston oil passage and the oil delivery pipe are connected.
[0005] In one embodiment of the present invention, the oil supply control assembly further includes an oil supply tank and a controller. One end of the oil supply pipe is connected to the piston oil passage, and the other end is connected to the oil supply tank. The controller is used to control the oil supply tank to supply oil to the piston oil passage through the oil supply pipe.
[0006] In one embodiment of the present invention, the float control assembly further includes a first plug, which extends into the float oil passage and is detachably connected to the valve seat. The upper end of the first plug is provided with a first limiting part for limiting and cooperating with the upper surface of the valve seat. The first plug is provided with a first through hole, and the float valve is inserted into the first through hole.
[0007] In one embodiment of the present invention, the upper end of the float valve is provided with a spring, a first baffle and a second baffle, both of which are sleeved on the float valve. The second baffle is located above the first baffle, and the spring is located between the first baffle and the second baffle. The second baffle and the float valve are fixedly connected, and the first baffle and the float valve are slidably engaged. The float valve is provided with a limiting step, and the bracket is located between the first baffle and the limiting step.
[0008] In one embodiment of the present invention, the lower end of the float valve is provided with an outer frame and an inner sealing head, the inner sealing head and the float valve are fixedly connected, the outer frame is sleeved outside the inner sealing head and the two are in a limiting fit, and the outer frame is in a limiting fit with the first through hole.
[0009] In one embodiment of the present invention, a first sealing ring is provided between the first plug and the first perforation.
[0010] In one embodiment of the present invention, the oil delivery control assembly further includes a second plug, which extends into the piston oil passage and is detachably connected to the valve seat. The upper end of the second plug is provided with a second limiting part for limiting and cooperating with the upper surface of the valve seat. The second plug is provided with a second through hole. The piston further includes a piston head and a piston rod, with the piston rod inserted into the second through hole. The piston head and the plug are in a limiting and cooperating relationship.
[0011] In one embodiment of the present invention, a second sealing ring is provided between the second plug and the second perforation.
[0012] In one embodiment of the present invention, the float support includes a top plate, a left side plate, a right side plate, and an extension plate. The left side plate and the right side plate are respectively connected to the two sides of the top plate. The valve seat includes a left positioning plate and a right positioning plate. The left side plate and the left positioning plate are rotatably connected, and the right side plate and the right positioning plate are rotatably connected. One end of the extension plate is connected to the top plate, and the other end is connected to the float element.
[0013] In one embodiment of the present invention, the lower end of the float oil passage is connected to a first connector, and the lower end of the piston oil passage is connected to a second connector.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: In the above-mentioned scheme of this application, the mechanical oil supply shut-off control valve includes a housing and a float control assembly and an oil supply control assembly installed in the housing. The housing is also provided with a valve seat, and the valve seat and the housing together form an oil supply chamber. The valve seat is provided with a float oil passage and a piston oil passage, both of which are connected to the oil supply chamber. The float control assembly includes a float valve, a float support, and a float element. One side of the float support is rotatably connected to the housing, and the other side is fixedly connected to the float element. One end of the float valve extends into the float oil passage, and the other end extends through the float oil passage and is connected to the float support. The oil supply control assembly includes a piston and an oil supply pipe. One end of the piston extends into the piston oil passage, and the other end extends through the piston oil passage and is connected to the float support. The piston oil passage is connected to the oil supply pipe. With this structure, as the fuel level in the tank rises, the float element floats, and the float element, through the float support, moves the float valve upwards. When the float element reaches a certain position, the float valve closes the float passage, preventing fuel from being output through the float passage and thus cutting off the fuel supply. If the float mechanism jams, or if an emergency operation requires prematurely cutting off the fuel supply, fuel can be introduced into the piston passage through the fuel supply pipe. The fuel lifts the piston, and as the piston moves, the float support moves the float valve upwards to close the float passage, thereby cutting off the fuel supply. The device described in this application offers higher safety and enables emergency operations that prematurely cut off the fuel supply.
[0015] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the oil supply cut-off control valve in an embodiment of the present invention; Figure 2 This is a three-dimensional view of the oil supply cut-off control valve in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the oil supply cut-off control valve in an embodiment of the present invention; Figure 4 This is a schematic diagram of the oil supply cut-off control valve in the open state in an embodiment of the present invention; Figure 5 This is a schematic diagram of the oil supply cut-off control valve in the closed state in an embodiment of the present invention.
[0017] Reference numerals: 1-Housing, 2-Float control assembly, 21-Float valve, 22-Float support, 23-Float element, 24-First plug, 3-Oil delivery control assembly, 31-Piston, 32-Second plug, 4-Valve seat, 5-Float oil passage, 6-Piston oil passage, 7-First connector, 8-Second connector. Detailed Implementation
[0018] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.
[0019] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 This invention provides a mechanical fuel supply cut-off control valve for an aircraft fuel system, comprising a housing 1 and a float control assembly 2 and a fuel supply control assembly 3 installed within the housing 1. The housing 1 also includes a valve seat 4, which, together with the housing 1, forms a fuel supply chamber. The valve seat 4 has a float oil passage 5 and a piston oil passage 6, both of which communicate with the fuel supply chamber. The float control assembly 2 includes a float valve 21, a float support 22, and a float element 23. One side of the float support 22 is rotatably connected to the valve seat 4, and the other side is fixedly connected to the float element 23. One end of the float valve 21 extends into the float oil passage 5, and the other end extends through the float oil passage 5 and is connected to the float support 22. The fuel supply control assembly 3 includes a piston 31 and a fuel supply pipe. One end of the piston 31 extends into the piston oil passage 6, and the other end extends through the piston oil passage 6 and is connected to the float support 22. The piston oil passage 6 is connected to the fuel supply pipe.
[0020] In some embodiments of this application, the housing 1 includes an upper housing and a bottom plate, and the valve seat 4 is mounted on the bottom plate.
[0021] In some embodiments of this application, the float valve 21 includes a long rod and a sealing head, the point where the float support 22 and the valve seat 4 are rotatably connected is the fulcrum, and the position where the float valve 21 is connected to the float is located between the fulcrum and the float element 23.
[0022] In some embodiments of this application, when the float element 23 rises with the liquid level, it can drive the float support 22 to rotate around the fulcrum. When the float support 22 rotates, it drives the float valve 21 to move upward and cut off the float oil passage 5. When the float support 22 rotates, it drives the piston 31 to move upward and cut off the piston oil passage 6. When the float element 23 falls, the float support 22 rotates around the fulcrum. When the float support 22 rotates, it drives the float valve 21 to move downward and open the float oil passage 5. When the float support 22 rotates, it drives the piston 31 to move downward and open the piston oil passage 6.
[0023] In some embodiments of this application, this embodiment includes two control methods. One is normal control, in which the float element 23 floats as the oil level in the tank rises. When the oil level reaches the level where the float valve 21 closes, pressure is built up inside the float valve 21, controlling the oil delivery valve to stop oil delivery. The other is emergency control, in which the oil level does not reach the level where the float valve 21 closes, pressure can be directly supplied to the control pipeline. The oil delivery pressure pushes the piston 31 to form a hard seal. Pressure is built up inside the piston 31 cavity, closing the oil delivery valve to stop oil delivery.
[0024] In some embodiments of this application, such as Figure 4 As shown, when the fuel level in the aircraft fuel tank is lower than the control valve float valve 21 (closed), the fuel supply valve starts supplying fuel, and fuel can flow out from the float valve 21.
[0025] In some embodiments of this application, such as Figure 5 As shown, when the fuel level in the aircraft fuel tank reaches the level where the control valve float valve 21 closes, the fuel delivery valve stops delivering fuel.
[0026] In the above-mentioned scheme of this application, the mechanical oil supply cut-off control valve includes a housing 1 and a float control assembly 2 and an oil supply control assembly 3 installed in the housing 1. The housing 1 is also provided with a valve seat 4, which together with the housing 1 forms an oil supply chamber. The valve seat 4 is provided with a float oil passage 5 and a piston oil passage 6, both of which are connected to the oil supply chamber. The float control assembly 2 includes a float valve 21, a float support 22, and a float element 23. One side of the float support 22 is rotatably connected to the housing 1, and the other side is fixedly connected to the float element 23. One end of the float valve 21 extends into the float oil passage 5, and the other end extends through the float oil passage 5 and is connected to the float support 22. The oil supply control assembly 3 includes a piston 31 and an oil supply pipe. One end of the piston 31 extends into the piston oil passage 6, and the other end extends through the piston oil passage 6 and is connected to the float support 22. The piston oil passage 6 is connected to the oil supply pipe. With this structure, as the fuel level in the tank rises, the float element 23 floats. The float element 23, via the float support 22, drives the float valve 21 upwards. When the float element 23 reaches a certain position, the float valve 21 closes the float oil passage 5, preventing fuel from being output through the float oil passage 5, thus cutting off the fuel supply channel. If the float mechanism jams, or if an emergency operation requires prematurely cutting off the fuel supply channel, fuel can be introduced into the piston oil passage 6 through the fuel supply pipe. The fuel lifts the piston 31, and as the piston 31 moves, it drives the float valve 21 upwards via the float support 22 to close the float oil passage 5, thereby cutting off the fuel supply channel. The device described in this application offers higher safety and enables emergency operations that prematurely cut off the fuel supply channel.
[0027] In some embodiments of this application, the fuel supply control assembly 3 further includes a fuel supply tank and a controller. One end of the fuel supply pipe is connected to the piston oil passage 6, and the other end is connected to the fuel supply tank. The controller is used to control the fuel supply tank to supply fuel to the piston oil passage 6 through the fuel supply pipe. With this structure, the fuel supply tank and controller are connected to the fuel supply pipe. When the float mechanism cannot work properly due to jamming or wear, the controller can start the fuel supply tank to supply fuel to the piston oil passage 6. The fuel pressure pushes the piston 31, which in turn drives the float valve 21 to close the float oil passage 5 through the float support 22, thus achieving fuel supply cut-off. This method does not rely on changes in liquid level and can provide an independent cut-off path in the event of float mechanism failure or the need to interrupt fuel supply in advance, which helps to reduce the risk of fuel spillage and improve the system's ability to cope with abnormal operating conditions.
[0028] In some embodiments of this application, such as Figure 1 , Figure 2 and Figure 3 As shown, the float control assembly 2 also includes a first plug 24, which extends into the float oil passage 5 and is detachably connected to the valve seat 4. The upper end of the first plug 24 has a first limiting part for limiting engagement with the upper surface of the valve seat 4. The first plug 24 has a first through hole, through which the float valve 21 is inserted. With this structure, the first plug 24 is detachably installed in the float oil passage 5 of the valve seat 4, facilitating the assembly or subsequent maintenance of the float valve 21 and related components. The first limiting part engages with the upper surface of the valve seat 4, positioning the plug and ensuring its stable installation depth and orientation within the oil passage. The float valve 21, inserted into the first through hole, guides the movement of the float valve 21, helping to maintain alignment during vertical movement and reducing the possibility of misalignment or jamming.
[0029] In some embodiments of this application, such as Figure 1 , Figure 2 and Figure 3As shown, the upper end of the float valve 21 is equipped with a spring, a first baffle, and a second baffle. Both the first and second baffles are fitted onto the float valve 21, with the second baffle positioned above the first baffle. The spring is located between the first and second baffles. The second baffle and the float valve 21 are fixedly connected, while the first baffle and the float valve 21 are in sliding contact. The float valve 21 has a limiting step, and a support is located between the first baffle and the limiting step. With this structure, the float support 22 is located between the first baffle and the limiting step, maintaining the relative position between the float valve 21 and the float support 22. The spring, located between the first and second baffles, provides a certain elastic force to the float valve 21, allowing it to maintain contact with the float support 22 through the first baffle during movement. When the float support 22 rotates with changes in the liquid level, it can drive the first baffle to slide along the float valve 21, transmitting the motion to the float valve 21. When the float valve 21 closes the float oil passage 5, if the float support 22 continues to move, the spring can be compressed to avoid rigid contact that could cause jamming or damage, while ensuring that the sealing force is maintained.
[0030] In some embodiments of this application, such as Figure 1 , Figure 2 and Figure 3 As shown, the lower end of the float valve 21 has an outer frame and an inner sealing head. The inner sealing head and the float valve 21 are fixedly connected. The outer frame is fitted over the inner sealing head and the two are in a limiting fit. The outer frame is also in a limiting fit with the first through hole. With this structure, the inner sealing head is fixedly connected to the float valve 21, the outer frame is fitted over the inner sealing head and the two are in a limiting fit, and the outer frame is also in a limiting fit with the first through hole. This allows the outer frame to move stably along the inner wall of the first through hole during movement, providing auxiliary guidance for the movement of the float valve 21. When the float valve 21 moves upward to the closed position, the inner sealing head contacts the sealing surface on the valve seat 4 to form a seal. The outer frame then supports and protects the sealing head, preventing it from shifting under stress and helping to maintain the reliability of the seal. Simultaneously, the limiting fit between the outer frame and the inner sealing head prevents relative rotation or detachment, ensuring the integrity of the structure.
[0031] In some embodiments of this application, such as Figure 3 As shown, a first sealing ring is provided between the first plug 24 and the first perforation. With this structure, the first sealing ring, installed between the first plug 24 and the first perforation, fills the gap between their mating surfaces, sealing the interior of the float oil passage 5 and preventing oil leakage from the connection between the plug and the valve seat 4. This helps maintain stable oil pressure within the float oil passage 5, ensuring the closed-loop flow of oil during normal operation of the float valve 21, while also reducing the possibility of external contaminants entering the oil passage.
[0032] In some embodiments of this application, such as Figure 3As shown, the oil supply control assembly 3 also includes a second plug 32, which extends into the piston oil passage 6 and is detachably connected to the valve seat 4. The upper end of the second plug 32 has a second limiting part for limiting engagement with the upper surface of the valve seat 4. The second plug 32 has a second through hole. The piston 31 also includes a piston head and a piston rod, with the piston rod inserted into the second through hole. The piston head and plug are in a limiting engagement. With this structure, the second plug 32 is detachably installed in the piston oil passage 6 of the valve seat 4, facilitating the disassembly, assembly, and maintenance of the piston 31 and related components. The second limiting part engages with the upper surface of the valve seat 4, positioning the plug and ensuring accurate installation depth within the oil passage. The piston rod is inserted into the second through hole, which guides the movement of the piston 31, helping to maintain the stability of the piston 31 during reciprocating movement. The piston head and the plug limit the piston 31 to its maximum extension position in the oil passage, preventing the piston 31 from leaving the working range, thereby ensuring a stable and reliable linkage between the piston 31 and the float support 22.
[0033] In some embodiments of this application, a second sealing ring is provided between the second plug 32 and the second perforation. With this structure, the second sealing ring, installed between the second plug 32 and the second perforation, seals the piston oil passage 6, preventing oil leakage from the connection between the plug and the valve seat 4. This helps maintain stable oil pressure within the piston oil passage 6, ensuring that the oil can effectively drive the piston 31 during emergency control or normal operation. Simultaneously, the sealing ring reduces the possibility of external contaminants entering the piston oil passage 6, thus helping to maintain a clean operating environment for the piston 31.
[0034] In some embodiments of this application, such as Figure 2 As shown, the float support 22 includes a top plate, a left side plate, a right side plate, and an extension plate. The left and right side plates are connected to the two sides of the top plate, respectively. The valve seat 4 includes a left positioning plate and a right positioning plate. The left and right side plates are rotatably connected, and the right and right side plates are rotatably connected. One end of the extension plate is connected to the top plate, and the other end is connected to the float element 23. With this structure, the left and right side plates are rotatably connected to the left and right positioning plates of the valve seat 4, respectively, allowing the float support 22 to rotate stably around the connection point. The top plate connects the left and right side plates, enhancing the overall rigidity of the support and keeping the rotational movements on both sides synchronized. One end of the extension plate is connected to the top plate, and the other end is connected to the float element 23, transmitting the buoyancy of the float element 23 to the support body. When the float element 23 rises and falls with the liquid level, the extension plate drives the support to rotate around the positioning plate, thereby driving the float valve 21 and piston 31 to move. This connection method allows the buoyancy of the float element 23 to be smoothly transmitted to the control components, helping to improve the reliability of the operation.
[0035] In some embodiments of this application, such as Figure 1and Figure 2 As shown, the lower end of the float oil passage 5 is connected to a first connector 7, and the lower end of the piston oil passage 6 is connected to a second connector 8. With this structure, the first connector 7 and the second connector 8 are respectively located at the lower ends of the float oil passage 5 and the piston oil passage 6, providing standard connection interfaces for external pipelines. This allows the control valve to be connected to other pipelines in the aircraft fuel system during installation, facilitating the flow of fuel from the float oil passage 5 and the piston oil passage 6. The connectors also improve the convenience and detachability of pipeline connections. During subsequent maintenance or component replacement, the internal structure of the valve body does not need to be disassembled; the control valve can be separated from the external pipeline simply by disassembling the connectors, helping to reduce maintenance difficulty.
[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," 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.
[0037] 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 technical features indicated. 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.
[0038] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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.
[0039] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.
Claims
1. A mechanical fuel supply cut-off control valve for an aircraft fuel system, characterized in that, The device includes a housing and a float control assembly and an oil delivery control assembly installed within the housing. The housing also contains a valve seat, which, together with the housing, forms an oil delivery chamber. The valve seat has a float oil passage and a piston oil passage, both of which are connected to the oil delivery chamber. The float control assembly includes a float valve, a float support, and a float element. One side of the float support is rotatably connected to the valve seat, and the other side is fixedly connected to the float element. One end of the float valve extends into the float oil passage, and the other end extends through the float oil passage and is connected to the float support. The oil delivery control assembly includes a piston and an oil delivery pipe. One end of the piston extends into the piston oil passage, and the other end extends through the piston oil passage and is connected to the float support. The piston oil passage and the oil delivery pipe are connected.
2. The mechanical fuel supply cut-off control valve for an aircraft fuel system according to claim 1, characterized in that, The oil supply control assembly also includes an oil supply tank and a controller. One end of the oil supply pipe is connected to the piston oil passage, and the other end is connected to the oil supply tank. The controller is used to control the oil supply tank to supply oil to the piston oil passage through the oil supply pipe.
3. The mechanical fuel supply cut-off control valve for an aircraft fuel system according to claim 1, characterized in that, The float control assembly further includes a first plug, which extends into the float oil passage and is detachably connected to the valve seat. The upper end of the first plug is provided with a first limiting part for limiting and cooperating with the upper surface of the valve seat. The first plug is provided with a first through hole, and the float valve is inserted into the first through hole.
4. The mechanical fuel supply cut-off control valve for an aircraft fuel system according to claim 3, characterized in that, The upper end of the float valve is provided with a spring, a first baffle, and a second baffle. The first baffle and the second baffle are both sleeved on the float valve, with the second baffle located above the first baffle. The spring is located between the first baffle and the second baffle. The second baffle and the float valve are fixedly connected. The first baffle and the float valve are slidably engaged. The float valve is provided with a limiting step, and the bracket is located between the first baffle and the limiting step.
5. The mechanical fuel supply cut-off control valve for an aircraft fuel system according to claim 3, characterized in that, The lower end of the float valve is provided with an outer frame and an inner sealing head. The inner sealing head and the float valve are fixedly connected. The outer frame is sleeved outside the inner sealing head and the two are in a limiting fit. The outer frame is in a limiting fit with the first through hole.
6. The mechanical fuel supply cut-off control valve for an aircraft fuel system according to claim 3, characterized in that, A first sealing ring is provided between the first plug and the first perforation.
7. The mechanical fuel supply cut-off control valve for an aircraft fuel system according to claim 1, characterized in that, The oil delivery control assembly also includes a second plug, which extends into the piston oil passage and is detachably connected to the valve seat. The upper end of the second plug is provided with a second limiting part for limiting cooperation with the upper surface of the valve seat. The second plug is provided with a second through hole. The piston also includes a piston head and a piston rod, with the piston rod inserted into the second through hole. The piston head and the plug are in limiting cooperation.
8. The mechanical fuel supply cut-off control valve for an aircraft fuel system according to claim 7, characterized in that, A second sealing ring is provided between the second plug and the second perforation.
9. The mechanical fuel supply cut-off control valve for an aircraft fuel system according to claim 1, characterized in that, The float support includes a top plate, a left side plate, a right side plate, and an extension plate. The left side plate and the right side plate are respectively connected to the two sides of the top plate. The valve seat includes a left positioning plate and a right positioning plate. The left side plate and the left positioning plate are rotatably connected, and the right side plate and the right positioning plate are rotatably connected. One end of the extension plate is connected to the top plate, and the other end is connected to the float element.
10. The mechanical fuel supply cut-off control valve for an aircraft fuel system according to claim 1, characterized in that, The lower end of the float oil passage is connected to a first connector, and the lower end of the piston oil passage is connected to a second connector.