A pressure refueling cut-off system capable of pre-inspection

Abstract

The present application provides a pressure refueling cut-off system capable of pre-inspection. The pressure refueling cut-off system includes an electrical switch 1, an electromagnetic relay 3, a control wire system 7, a float 18, a plunger rod 32, a control pipe assembly I 19, a control pipe assembly II 20, and a cut-off valve assembly 9, wherein: The electrical switch 1 and the electromagnetic relay 3 are connected by an electrical cable. The electromagnetic relay 3 and the float 18 are connected through the control wire system 7 and a lever assembly 4. The float 18 and the plunger rod 32 are connected by a float support rod 6. The control pipe assembly I 19 and the control pipe assembly II 20 are respectively connected to the inlet end of the plunger rod 32. One end of the cut-off valve assembly 9 is a fuel inlet end, and the other end is a fuel outlet end.

Description

Technical Field

[0001] The present invention relates to the field of helicopter fuel system design, and particularly to a pressure refueling cut-off system that can perform pre-inspection. Background Art

[0002] Basically, contemporary large and medium-sized aircraft and helicopters are equipped with a pressure refueling system, and correspondingly, a pressure refueling cut-off system is also provided. Some aircraft pressure refueling systems are also equipped with a pre-inspection function. The pressure refueling cut-off systems adopted by different types of aircraft and different aircraft manufacturers are different. Some use an electric cut-off valve to cut off the pressure refueling, and some use a mechanical float + elastic diaphragm to cut off the pressure refueling.

[0003] In terms of the pre-inspection function of pressure refueling, on some aircraft, an electric cut-off valve is used for pre-inspecting the pressure refueling cut-off, and on some, an electromagnetic relay is set on the mechanical float inside the fuel tank to perform the pre-inspection of the pressure refueling cut-off.

[0004] However, there is a risk of fire caused by the contact between electrical components and fuel in the existing pressure refueling cut-off system in terms of the pre-inspection function. Summary of the Invention

[0005] This patent designs a pressure refueling cut-off system that can perform pre-inspection, which is a new type of pressure refueling cut-off system that uses a mechanical float + double-spring valve to cut off the pressure refueling.

[0006] Technical Solution: A pressure refueling cut-off system that can perform pre-inspection, the pressure refueling cut-off system includes an electrical switch 1, an electromagnetic relay 3, a control wire system 7, a float 18, a plunger rod 32, a control pipe assembly I 19 and a control pipe assembly II 20, and a cut-off valve assembly 9, wherein:

[0007] The electrical switch 1 and the electromagnetic relay 3 are connected by an electrical cable. The electromagnetic relay 3 and the float 18 are connected through the control wire system 7 and a lever assembly 4. The float 18 and the plunger rod 32 are connected by a float support rod 6. The control pipe assembly I 19 and the control pipe assembly II 20 are respectively connected to the inlet end of the plunger rod 32;

[0008] One end of the cut-off valve assembly 9 is the fuel inlet end, and the other end is the fuel outlet end. The fuel inlet end of the cut-off valve assembly is connected to the pressure fueling port of the fuel tank in the form of a flange by the cut-off valve housing. The cut-off valve housing is a hollow tubular structure, and a pair of symmetrically installed hollow cylindrical sealing valves, namely the left sealing valve assembly 11 and the right sealing valve assembly 17, are arranged along the central axis of the tube body inside it. The left sealing valve assembly 11 and the right sealing valve assembly 17 are respectively composed of a sealing valve housing 33 and a sealing valve 34. The sealing valve 34 is nested inside the sealing valve housing 33. A dynamic sealing groove is arranged outside the sealing valve, and a dynamic sealing ring 26 is installed, which can realize the dynamic sealing between the sealing valve and the sealing valve housing.

[0009] Specifically, the left sealing valve assembly 11 is sealed with the housing at the inlet end of the cut-off valve assembly by the left sealing valve gasket 22, and the right sealing valve assembly 17 is sealed with the housing at the outlet end of the cut-off valve assembly by the right sealing valve gasket 16. Inside the left sealing valve assembly 11 and the right sealing valve assembly 17, along the central axis of the tube body, a cylindrical support conduit 30 is arranged. The outside of the support conduit 30 is sleeved with a left sealing valve inner spring 27 and a right sealing valve inner spring 29. Among them, the left sealing valve inner spring 27 is located in the inner cavity of the left sealing valve, and the right sealing valve inner spring 29 is located in the inner cavity of the right sealing valve. The sealing valve 34 can move back and forth telescopically along the support conduit 30 in the sealing valve housing under the action of the inner spring and fuel pressure.

[0010] Specifically, between the left sealing valve assembly 11 and the cut-off valve housing, a diversion tube inlet end I 12 and a diversion tube inlet end II 23 are arranged.

[0011] Specifically, at the outlet end of the cut-off valve assembly, there are a cut-off valve outlet, an inlet end 15 of the control tube assembly I, and an inlet end 28 of the control tube assembly II. Among them, the fuel for pressure fueling directly enters the fuel tank 18 from the cut-off valve outlet. The inlet end 15 of the control tube assembly I is connected to the control tube assembly I 19, and the inlet end 28 of the control tube assembly II is connected to the control tube assembly II 20.

[0012] Specifically, a diversion tube I 13 is arranged between the diversion tube inlet end I 12 and the inlet end 15 of the control tube assembly I, and a diversion tube II 24 is arranged between the diversion tube inlet end II 23 and the inlet end 28 of the control tube assembly II. Diversion holes I 14 and diversion holes II 25 are respectively opened in the middle parts of the diversion tube 13 and the diversion tube 24. Among them, the diversion hole I 14 is communicated with the inner cavity of the left sealing valve, and the diversion hole II 25 is communicated with the inner cavity of the right sealing valve.

[0013] Specifically, the outlet ends of the control tube assembly I 19 and the control tube assembly II 20 are respectively connected to the inlet ends of two plunger rods 32 installed in the upper space of the fuel tank, and the outlet end of each plunger rod 32 is respectively connected to the float 18 by a float support rod 6.

[0014] Specifically, the float 18, the plunger rod 32, and the float support rod 6 are all located inside the float end cap 8. The float end cap 8 is a cylindrical cup structure with an opening facing downwards. The outer shell of the plunger rod 32 is connected to the inner side of the float end cap 8.

[0015] Specifically, a connection end 5 of the control wire system 7 is provided on the upper part of each float 18. One end of the control wire system 7 is connected to this connection end, and the other end is connected to a lever assembly outside the fuel tank. The other end of the lever assembly is connected to the electromagnetic relay 3 by the control wire system 7.

[0016] In summary, this patent proposes a pressure refueling cut-off system that can perform pre-inspection. It can adopt a combination of remote electronic control outside the fuel tank and short-range wire system operation inside the fuel tank to achieve the function of pre-inspecting pressure refueling. It can not only achieve pre-inspection of pressure refueling through remote electronic control, but also avoid the contact between electrical components in the fuel tank and fuel, improving the safety of the fuel tank. This patent can provide a feasible reference solution for the pressure refueling cut-off systems of various aircraft. Brief Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of a pressure refueling cut-off system that can perform pre-inspection provided by this application.

[0018] Wherein: 1 - electrical switch, 2 - electrical cable, 3 - electromagnetic relay, 4 - lever assembly, 5 - connection end, 6 - float support rod, 7 - control wire system, 8 - float end cap, 8 - cut-off valve housing, 9 - cut-off valve assembly, 10 - cut-off valve housing, 11 - left sealing valve assembly, 12 - inlet end Ⅰ of the diversion pipe, 13 - diversion pipe Ⅰ, 14 - diversion hole Ⅰ, 15 - inlet end of the control pipe assembly Ⅰ, 16 - right sealing valve gasket, 17 - right sealing valve assembly, 18 - float, 19 - control pipe assembly Ⅰ, 20 - control pipe assembly Ⅱ, 21 - weak link of the cut-off valve, 22 - left sealing valve gasket, 23 - inlet end Ⅱ of the diversion pipe, 24 - diversion pipe Ⅱ, 25 - diversion hole Ⅱ, 26 - dynamic sealing ring, 27 - inner spring of the left sealing valve, 28 - inlet end of the control pipe assembly Ⅱ, 29 - inner spring of the right sealing valve, 30 - support conduit, 31 - fuel tank, 32 - plunger rod, 33 - sealing valve housing, 34 - sealing valve. Detailed Embodiment

[0019] As Figure 1 shown, this application provides a pressure refueling cut-off system that can perform pre-inspection, including an electrical switch 1, an electromagnetic relay 3, a control wire system 7, a float 18, a plunger rod 32, a control pipe assembly Ⅰ 19, a control pipe assembly Ⅱ 20, and a cut-off valve assembly 9, wherein:

[0020] The electrical switch 1 and the electromagnetic relay 3 are connected by an electrical cable. The electromagnetic relay 3 and the float 18 are connected by a control wire system 7 and a lever assembly 4. The float 18 and the plunger rod 32 are connected by a float support rod 6. The control pipe assembly I 19 and the control pipe assembly II 20 are respectively connected to the inlet end of the plunger rod 32;

[0021] One end of the cut-off valve assembly 9 is the fuel inlet end, and the other end is the fuel outlet end. The fuel inlet end of the cut-off valve assembly is connected to the pressure fuel filling port of the fuel tank in the form of a flange by the cut-off valve housing. The cut-off valve housing is a hollow tubular structure, and a pair of symmetrically installed hollow cylindrical sealing valves, namely the left sealing valve assembly 11 and the right sealing valve assembly 17, are arranged on the central axis of the pipe body inside it. The left sealing valve assembly 11 and the right sealing valve assembly 17 are respectively composed of a sealing valve housing 33 and a sealing valve 34. The sealing valve 34 is nested inside the sealing valve housing 33. A dynamic sealing groove is arranged outside the sealing valve, and a dynamic sealing ring 26 is installed to achieve dynamic sealing between the sealing valve and the sealing valve housing.

[0022] The left sealing valve assembly 11 is sealed with the housing at the inlet end of the cut-off valve assembly by the left sealing valve gasket 22, and the right sealing valve assembly 17 is sealed with the housing at the outlet end of the cut-off valve assembly by the right sealing valve gasket 16. Inside the left sealing valve assembly 11 and the right sealing valve assembly 17, along the central axis of the pipe body, a cylindrical support conduit 30 is arranged. The left sealing valve inner spring 27 and the right sealing valve inner spring 29 are sleeved outside the support conduit 30. Among them, the left sealing valve inner spring 27 is located in the inner cavity of the left sealing valve, and the right sealing valve inner spring 29 is located in the inner cavity of the right sealing valve. The sealing valve 34 can make reciprocating telescopic movement along the support conduit 30 in the sealing valve housing under the action of the inner spring and the fuel pressure.

[0023] Between the left sealing valve assembly 11 and the cut-off valve housing, a guide pipe inlet end I 12 and a guide pipe inlet end II 23 are arranged.

[0024] At the outlet end of the cut-off valve assembly, a cut-off valve outlet, a control pipe assembly I inlet end 15 and a control pipe assembly II inlet end 28 are arranged. Among them, the fuel for pressure fuel filling directly enters the fuel tank 18 from the cut-off valve outlet. The control pipe assembly I inlet end 15 is connected to the control pipe assembly I 19, and the control pipe assembly II inlet end 28 is connected to the control pipe assembly II 20.

[0025] A guide pipe I 13 is arranged between the guide pipe inlet end I 12 and the control pipe assembly I inlet end 15, and a guide pipe II 24 is arranged between the guide pipe inlet end II 23 and the control pipe assembly II inlet end 28. Guide holes I 14 and guide holes II 25 are respectively opened in the middle parts of the guide pipe 13 and the guide pipe 24. Among them, the guide hole I 14 is communicated with the inner cavity of the left sealing valve, and the guide hole II 25 is communicated with the inner cavity of the right sealing valve.

[0026] The outlet ends of the control pipe assembly I 19 and the control pipe assembly II 20 are respectively connected to the inlet ends of two plunger rods 32 installed in the upper space of the fuel tank, and the outlet end of each plunger rod 32 is respectively connected to a float support rod 6 and a float 18. The float 18, the plunger rod 32, and the float support rod 6 are all located inside the float end cover 8. The float end cover 8 is a cylindrical cup structure with an opening facing downwards, and the outer shell of the plunger rod 32 is connected to the inner side of the float end cover 8.

[0027] A connection end 5 of a control wire system 7 is arranged on the upper part of each float 18. One end of the control wire system 7 is connected to this connection end, and the other end is connected to a lever assembly outside the fuel tank. The other end of the lever assembly is connected to the electromagnetic relay 3 by the control wire system 7. The electromagnetic relay is controlled to be energized and act by an electrical switch.

[0028] When a pressure refueling vehicle or a pressure refueling station outside the aircraft conducts pressure refueling on the aircraft fuel tank (31), the fuel will flow into the cut-off valve assembly 9 from the inlet of the cut-off valve, and overcome the spring force of the left sealing valve spring (27) inside the left sealing valve assembly (9), causing the spring (27) to be compressed and contract, driving the left sealing valve to move inwards, thereby opening the left sealing valve. After the pressurized fuel flows into the left fuel passage, it continues to flow forward to the right sealing valve assembly (17). The originally closed right sealing valve will be reversely pressured (subjected to the fuel pressure towards the left) due to the gradually increasing fuel pressure on its outer side. When the reverse pressure is greater than the elastic force of the spring (29) inside the right sealing valve, the spring contracts and drives the right sealing valve to move inwards and to the left, thereby opening the right sealing valve, and the fuel will flow into the fuel tank from the outlet of the cut-off valve.

[0029] Under normal circumstances, after the left sealing valve is opened, the fuel flowing into the cut-off valve will also respectively pass through the inlet end (12) of the guide pipe I and the inlet end (23) of the guide pipe II, flow along the control pipe assembly I (19) and the control pipe assembly II (20), towards the plunger rod (32) located in the upper space of the fuel tank, and finally flow into the fuel tank along the peripheral channel of the plunger rod.

[0030] When the fuel level in the fuel tank reaches the position of the float (18), that is, when the fuel reaches the high level, the float (18) floats upward under the buoyancy of the fuel, driving the float support rod and the plunger rod to move upward, so that the plunger rod blocks the fuel passage around it, causing the fuel not to flow out along the control pipe assemblies I and II. When the float corresponding to the control pipe assembly I floats, the fuel that could originally flow into the control pipe assembly I will turn and flow into the inner cavity of the left sealing valve along the diversion hole I (14) because the outlet passage of the control pipe assembly I is blocked. As the fuel pressure in the inner cavity of the left sealing valve increases and the pressure difference with the outside of the left sealing valve decreases to a certain value, the left sealing valve will move leftward under the restoring force of the spring (27) inside the left sealing valve and finally block the inlet of the cut-off valve, and the external fuel can no longer enter the fuel tank. Similarly, when the float corresponding to the control pipe assembly II floats, the right sealing valve will move rightward under the restoring force of the spring (29) inside the right sealing valve and finally block the outlet of the cut-off valve, and the external fuel can also no longer enter the fuel tank.

[0031] When pressure refueling the fuel tank, in order to pre-check the cut-off function of the cut-off valve before the fuel reaches the high level, the electrical switch (1) can be turned on to energize the electromagnetic relay (3) to contract, driving the operating wire system outside the fuel tank to contract in the direction of the electromagnetic relay. Under the direction conversion of the lever assembly, the operating wire system inside the fuel tank will be pulled upward, and then the float (18) will be pulled upward, simulating the float floating under the buoyancy of the fuel, so that the plunger rod can close the outlets of the control pipe assembly I and the control pipe assembly II, so as to check whether the cut-off valve can cut off the fuel flow normally.

[0032] When the fuel tank undergoes a crash, when the tangential force borne by the cut-off valve housing during the crash reaches a certain value, the weak point (21) of the cut-off valve housing will break, preventing the fuel tank wall from being pierced or torn and causing a large amount of fuel leakage.

[0033] This patent has the following characteristics:

[0034] 1. This pressure refueling cut-off system has two independent sub-cut-off systems. Each sub-cut-off system includes 1 float, 1 sealing valve and 1 control pipe assembly. Any one of the sub-cut-off systems can achieve the function of pressure refueling cut-off, which can improve the reliability of the pressure refueling cut-off function;

[0035] 2. This pressure refueling cut-off system has a pre-check function, which can pre-check the functions of the two independent sub-cut-off systems;

[0036] 3. This pressure refueling cut-off system is designed with a relay, a control wire system, and a lever assembly installed outside the fuel tank. The control wire system is connected to the float inside the fuel tank. There are no electrical components inside the fuel tank, and no electrical components come into contact with the fuel, thus enhancing the safety of the fuel tank.

[0037] 4. The pre-inspection function of this pressure refueling cut-off system adopts a dual-redundancy design, improving the reliability of pre-inspection.

[0038] 5. The cut-off valve housing is provided with weak links, which can meet the performance requirements of the fuel tank for anti-drop collision.

[0039] 6. The connections between the components of this pressure refueling cut-off system are simple, easy to disassemble and assemble, and have good maintainability.

[0040] In summary, this patent proposes a pressure refueling cut-off system with pre-inspection function. The pre-inspection function of pressure refueling can be realized by combining remote electronic control outside the fuel tank and short-range wire system operation inside the fuel tank. It can not only achieve pre-inspection of pressure refueling through remote electronic control, but also avoid the contact between electrical components in the fuel tank and the fuel, enhancing the safety of the fuel tank. This patent can provide a feasible reference solution for the pressure refueling cut-off systems of various aircraft.

Claims

1. A pressure refueling cut-off system capable of pre-inspection, characterized in that, the pressure refueling cut-off system includes an electrical switch (1), an electromagnetic relay (3), a control wire system (7), a float (18), a plunger rod (32), a control pipe assembly I (19) and a control pipe assembly II (20), and a cut-off valve assembly (9), wherein: the electrical switch (1) and the electromagnetic relay (3) are connected by an electrical cable, the electromagnetic relay (3) and the float (18) are connected by the control wire system (7) and a lever assembly (4), the float (18) and the plunger rod (32) are connected by a float support rod (6), and the control pipe assembly I (19) and the control pipe assembly II (20) are respectively connected to the inlet end of the plunger rod (32); one end of the cut-off valve assembly (9) is the fuel inlet end, and the other end is the fuel outlet end; the fuel inlet end of the cut-off valve assembly is connected to the pressure refueling port of the fuel tank in the form of a flange by the cut-off valve housing; the cut-off valve housing is a hollow tubular structure, and a pair of symmetrically installed hollow cylindrical sealing valves, namely a left sealing valve assembly (11) and a right sealing valve assembly (17), are arranged on the central axis of the pipe body inside it; the left sealing valve assembly (11) and the right sealing valve assembly (17) are respectively composed of a sealing valve housing (33) and a sealing valve (34), the sealing valve (34) is nested inside the sealing valve housing (33), a dynamic sealing groove is arranged outside the sealing valve, and a dynamic sealing ring (26) is installed to realize the dynamic sealing between the sealing valve and the sealing valve housing; between the left sealing valve assembly (11) and the cut-off valve housing, a diversion pipe inlet end I (12) and a diversion pipe inlet end II (23) are arranged; a diversion pipe I (13) is arranged between the diversion pipe inlet end I (12) and the inlet end (15) of the control pipe assembly I, and a diversion pipe II (24) is arranged between the diversion pipe inlet end II (23) and the inlet end (28) of the control pipe assembly II; diversion holes I (14) and II (25) are respectively opened in the middle parts of the diversion pipes (13) and (24), wherein the diversion hole I (14) communicates with the inner cavity of the left sealing valve, and the diversion hole II (25) communicates with the inner cavity of the right sealing valve; a connection end (5) of a control wire system (7) is arranged on the upper part of each float (18), one end of the control wire system (7) is connected to this connection end, and the other end is connected to a lever assembly outside the fuel tank; the other end of the lever assembly is connected to the electromagnetic relay (3) by the control wire system (7).

2. The pressure refueling cut-off system according to claim 1, characterized in that, The left sealing valve assembly (11) is sealed with the housing at the inlet end of the shut-off valve assembly by the left sealing valve gasket (22), and the right sealing valve assembly (17) is sealed with the housing at the outlet end of the shut-off valve assembly by the right sealing valve gasket (16); inside the left sealing valve assembly (11) and the right sealing valve assembly (17), along the central axis of the pipe body, a cylindrical support conduit (30) is provided. The outer part of the support conduit (30) is sleeved with a left sealing valve inner spring (27) and a right sealing valve inner spring (29), wherein the left sealing valve inner spring (27) is located in the inner cavity of the left sealing valve, and the right sealing valve inner spring (29) is located in the inner cavity of the right sealing valve; the sealing valve (34) can make reciprocating telescopic movement along the support conduit (30) in the sealing valve housing under the action of the inner spring and the fuel pressure.

3. The pressure refueling cut-off system according to claim 1, characterized in that, at the outlet end of the shut-off valve assembly, there are provided a shut-off valve outlet, an inlet end (15) of the control pipe assembly I and an inlet end (28) of the control pipe assembly II. Among them, the fuel for pressure refueling directly enters the fuel tank (18) from the shut-off valve outlet. The inlet end (15) of the control pipe assembly I is connected to the control pipe assembly I (19), and the inlet end (28) of the control pipe assembly II is connected to the control pipe assembly II (20).

4. The pressure refueling cut-off system according to claim 1, characterized in that, the outlet ends of the control pipe assembly I (19) and the control pipe assembly II (20) are respectively connected to the inlet ends of two plunger rods (32) installed in the upper space of the fuel tank, and the outlet end of each plunger rod (32) is respectively connected to a float (18) by a float support rod (6).

5. The pressure refueling cut-off system according to claim 1, characterized in that, the float (18), the plunger rod (32) and the float support rod (6) are all located inside the float end cover (8). The float end cover (8) is a cylindrical cup structure with an opening facing downwards, and the outer shell of the plunger rod (32) is connected to the inner side of the float end cover (8).

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