A multifunction breather valve for a helicopter fuel system

Abstract

The application provides a multifunctional breather valve for a helicopter fuel system, which comprises a spring 1, a valve assembly, a valve base 8, and a shell 11, wherein the valve assembly comprises a valve cavity shell 2, a float 3, a float cavity 4, a sealing ring 1 5, a valve cavity base 6, a sealing ring 2 7, a sealing ring 3 9, and a steel ball 10, and wherein the valve base 8 is a hollow cylindrical structure, the bottom end of the valve base 8 is a mounting flange structure, and the upper end of the valve base 8 is provided with an outwardly turned boss structure; the shell 11 is a hollow cylindrical structure, the boss of the upper end of the valve base 8 is assembled in the bottom end of the shell 11, and the top end of the shell 11 is the outlet of the multifunctional breather valve; the valve base 8 and the shell 11 constitute a breather valve shell, the internal cavities of the valve base 8 and the shell 11 are provided with the spring 1 and the valve assembly; one end of the spring 1 is fixed on the upper part of the shell 11, and the other end is fixed on the upper part of the valve cavity shell 2; and the valve assembly is pressed on the valve base 8 under the action of the spring 1.

Description

Technical Field

[0001] This invention relates to the field of helicopter fuel system design, and specifically to a multi-functional vent valve for helicopter fuel systems. Background Technology

[0002] During normal flight and refueling of the helicopter, the helicopter fuel system should ensure that the vent pipe between the fuel tank and the outside atmosphere is unobstructed. By exchanging with the outside atmosphere, the gas pressure in the fuel tank is regulated so that the difference between the gas pressure inside the fuel tank and the outside atmospheric pressure is within the pressure range of the fuel tank and the fuselage structure.

[0003] When a helicopter rolls or performs large-scale maneuvers that cause fuel in the fuel tank to enter the vent line, the helicopter fuel system needs to install a vent valve in the vent line to prevent fuel in the fuel tank from being discharged outside the aircraft through the vent line.

[0004] When a helicopter is pressurized for refueling, if refueling cannot be stopped in time after the fuel tank is full, a pressure relief valve and an overflow pipe are required to allow the excess fuel to be discharged outside the aircraft.

[0005] Existing vent valves cannot simultaneously perform three functions: normally open, closed when fuel enters the valve inlet, and open when the fuel pressure at the valve inlet reaches a specified pressure. This prevents the helicopter fuel system from using the vent line as a pressure refueling overflow line, requiring additional pressure relief valves and overflow lines, thus increasing system weight. Therefore, designing a vent valve that simultaneously possesses all three functions is of practical significance for optimizing system design and reducing system weight. Summary of the Invention

[0006] This application provides a multi-functional vent valve for helicopter fuel systems, which can simultaneously perform three functions: normally open in the normal state, closed when fuel enters the valve inlet, and open when the oil pressure at the valve inlet reaches a specified pressure. This can optimize system design and reduce system weight.

[0007] Technical solution: A multi-functional vent valve for a helicopter fuel system, comprising a spring 1, a valve assembly, a valve base 8, and a housing 11. The valve assembly comprises a valve cavity housing 2, a float 3, a float cavity 4, a first sealing ring 5, a valve cavity base 6, a second sealing ring 7, a third sealing ring 9, and a steel ball 10, wherein:

[0008] The valve base 8 is a hollow columnar structure with a mounting flange at its bottom and an outwardly flared boss at its top. The housing 11 is also a hollow columnar structure with the boss at the top of the valve base 8 fitted into the bottom of the housing 11. The top of the housing 11 is the outlet of the multi-functional vent valve. The valve base 8 and the housing 11 together form the vent valve housing. The internal cavities of the valve base 8 and the housing 11 contain a spring 1 and a valve assembly. One end of the spring 1 is fixed to the upper part of the housing 11, and the other end is fixed to the upper part of the valve cavity housing 2. The valve assembly is pressed against the valve base 8 by the action of the spring 1.

[0009] The top of the valve cavity housing 2, the bottom of the valve cavity base 6, and the bottom of the float cavity 4 are all provided with through holes; the float 3 and the steel ball 10 are located inside the float cavity 4; the upper part of the valve cavity base 6 is installed on the top of the valve base 8, the top of the valve cavity base 6 is a downwardly inclined conical surface with through holes, the lower part of the valve cavity housing 2 is installed on the upper part of the valve cavity base 6, the float cavity 4 is installed on the upper part of the valve cavity base 6 and inside the valve cavity housing 2, the bottom of the float cavity 4 is a downwardly inclined conical surface with through holes, the top of the float cavity 4 is open, the float 3 is installed inside the float cavity 4, and the bottom of the float 3 is pressed on the steel ball 10.

[0010] Specifically, the float cavity 4 is secured within the valve cavity housing 2 by N small support arms, thus fixing the float cavity 4 within the valve cavity housing 2. The float cavity 4 moves together with the valve cavity housing 2 and the valve cavity base 6.

[0011] Specifically, the valve cavity housing 2 and the valve cavity base 6 are connected by threads and sealed with a sealing ring 5.

[0012] Specifically, the range of N is 3-6.

[0013] Specifically, the gap between the float cavity 4 and the valve cavity housing 2 is 7-10 mm.

[0014] Specifically, the valve cavity base 6 and the valve base 8 are sealed by a sealing ring 9.

[0015] Specifically, a sealing ring 7 is used to seal the valve base 8 and the housing 11.

[0016] Specifically, the outer diameter of the boss structure at the upper end of the valve base 8 is... Inner diameter is Thickness is 3mm;

[0017] The dimensions of the bottom mounting flange structure of valve base 8, with an outer diameter of [missing information]. Inner diameter is The thickness is 3mm.

[0018] Specifically, the valve cavity base 6 has 4-8 through holes with a radius of 5-10 mm, and the float cavity 4 has 4-8 through holes with a radius of 5-10 mm.

[0019] In summary, this application provides a multi-functional vent valve for a helicopter fuel system, which has the following functions:

[0020] Under normal operating conditions, the valve passage remains open;

[0021] b. When fuel enters the valve inlet, the valve passage is closed;

[0022] c. When the fuel pressure at the valve inlet reaches the specified pressure, the valve passage reopens. Attached Figure Description

[0023] Figure 1 A schematic diagram of the structure of a multi-functional vent valve for a helicopter fuel system provided in this application;

[0024] Figure 2 This application provides a schematic diagram of the structure of a float cavity;

[0025] Figure 3 A schematic diagram of a multi-functional vent valve with its valve passage open in normal working condition, provided for this application;

[0026] Figure 4 A schematic diagram of a multi-functional vent valve provided in this application, which allows fuel to enter the valve and open the float valve passage;

[0027] Figure 5 A schematic diagram of a multi-functional vent valve provided in this application, in which a steel ball lifts the float valve channel to close under large posture conditions;

[0028] Figure 6 A schematic diagram of a multi-functional vent valve that opens when the fuel pressure reaches the valve opening pressure channel, as provided in this application.

[0029] Wherein: 1-Spring, 2-Valve cavity housing, 3-Float, 4-Float cavity, 5-Sealing ring one, 6-Valve cavity base, 7-Sealing ring two, 8-Valve base, 9-Sealing ring three, 10-Steel ball, 11-Housing. Detailed Implementation

[0030] like Figure 1 The diagram shown is a structural schematic of a multi-functional vent valve for a helicopter fuel system provided in this application. The multi-functional vent valve is a bidirectional normally open valve structure, and its function is achieved through the valve cavity housing 2 and the steel ball 10 and float 3 inside the valve cavity.

[0031] The multi-functional vent valve includes a spring 1, a valve assembly, a valve base 8, and a housing 11. The valve assembly includes a valve cavity housing 2, a float 3, a float cavity 4, a first sealing ring 5, a valve cavity base 6, a second sealing ring 7, a third sealing ring 9, and a steel ball 10.

[0032] The valve base 8 is a hollow columnar structure with a mounting flange at the bottom and an outwardly flared boss at the top. The housing 11 is also a hollow columnar structure with the boss at the top of the valve base 8 fitted into the bottom of the housing 11. The top of the housing 11 is the outlet of the multi-functional vent valve. The valve base 8 and the housing 11 together form the vent valve housing. The internal cavities of the valve base 8 and the housing 11 contain a spring 1 and a valve assembly. One end of the spring 1 is fixed to the upper part of the housing 11, and the other end is fixed to the upper part of the valve cavity housing 2. The valve assembly is pressed against the valve base 8 by the action of the spring 1.

[0033] The valve cavity housing 2 has passage holes at its top, the valve cavity base 6 at its bottom, and the float cavity 4 at its bottom. The float 3 and the steel ball 10 are located inside the float cavity 4. The upper part of the valve cavity base 6 is mounted on the top of the valve base 8. The top of the valve cavity base 6 is a downwardly sloping conical surface with passage holes. The lower part of the valve cavity housing 2 is mounted on the upper part of the valve cavity base 6. The float cavity 4 is mounted on the upper part of the valve cavity base 6 and inside the valve cavity housing 2. The bottom of the float cavity 4 is a downwardly sloping conical surface with passage holes. The top of the float cavity 4 is open. The float 3 is installed inside the float cavity 4, and the bottom of the float 3 rests on the steel ball 10.

[0034] Specifically, such as Figure 2 As shown, the float cavity 4 is secured inside the valve cavity housing 2 by N small support arms, thus fixing the float cavity 4 inside the valve cavity housing 2. The float cavity 4 moves together with the valve cavity housing 2 and the valve cavity base 6.

[0035] Specifically, the valve cavity housing 2 and the valve cavity base 6 are connected by threads and sealed with a sealing ring 5.

[0036] Specifically, the dimensions of the bottom flange structure of the valve base 8 are as follows: outer diameter is... Inner diameter is The thickness is 3mm.

[0037] The outer diameter of the boss structure at the upper end of the valve base 8 is [missing information]. Inner diameter is The thickness is 3mm.

[0038] Specifically, a sealing ring 7 is used to seal the valve base 8 and the housing 11.

[0039] Specifically, the valve cavity base 6 and the valve base 8 are sealed by a sealing ring 9.

[0040] Specifically, the gap between the float cavity 4 and the valve cavity housing 2 is 7-10 mm.

[0041] Specifically, the range of N is 3-6.

[0042] Specifically, the valve cavity base 6 has 4-8 through holes with a radius of 5-10 mm, and the float cavity 4 has 4-8 through holes with a radius of 5-10 mm.

[0043] The working principle of the multi-functional vent valve is as follows: Figure 3-6 As shown.

[0044] like Figure 3 As shown, in normal operation, the float 3 of the multi-functional vent valve rests on the steel ball 10 under gravity. There is a 5-10mm gap between the top of the float 3 and the top of the valve housing 2. At this time, the valve assembly inside the vent valve is normally open. When the air pressure at the valve inlet is greater than the air pressure at the valve outlet, air is discharged outwards through the valve inlet, the through hole of the valve housing base 6, the gap between the valve housing base 6 and the float cavity 4, the gap between the float cavity 4 and the valve housing 2, the spring 1, and the valve outlet. When the air pressure at the valve outlet is greater than the air pressure at the valve inlet, air enters inwards through the spring 1, the gap between the float cavity 4 and the valve housing 2, the gap between the valve housing base 6 and the float cavity 4, the through hole of the valve housing base 6, and the valve inlet.

[0045] like Figure 4 As shown, in the event of helicopter rollover or overload, fuel enters the valve through the inlet of the multi-function vent valve. When the fuel enters the valve and lifts the float, and the valve passage is closed, the fuel enters the float chamber 4 through the valve inlet, the through hole of the valve chamber base 6, and the through hole of the float chamber 4. As more fuel enters the float chamber 4, the float 3 rises under the action of the fuel and blocks the opening at the top of the valve chamber housing 2, thereby closing the valve chamber outlet and shutting off the valve outlet passage, preventing fuel from flowing out of the valve outlet.

[0046] like Figure 5 As shown, when the multi-functional vent valve reaches a certain tilt angle, the steel ball lifts the float, and the valve channel is closed. In the working state, as the tilt angle increases, the position of the steel ball 10 changes from the bottom of the cone surface of the float cavity 4 to the top of the cone surface of the float cavity 4. The float 3 will be lifted by the steel ball 10. The rising float 3 will block the opening of the valve cavity housing 2, thereby sealing the valve cavity outlet and closing the valve channel to prevent fuel from flowing out of the helicopter during large attitude maneuvers.

[0047] like Figure 6As shown, when the fuel pressure inside the multi-functional vent valve reaches the valve opening pressure and the valve channel is open, fuel first enters the float chamber 4 through the valve inlet, the through hole of the valve chamber base 6, and the through hole of the float chamber 4. As more fuel enters the float chamber 4, the float 3 rises under the action of the fuel, blocking the opening at the top of the valve chamber housing 2, preventing fuel from flowing out of the valve outlet. The valve chamber assembly is filled with fuel. As the fuel pressure inside the valve continues to increase, the pressure of the fuel acting on the valve chamber base 6 increases. When the fuel pressure at the valve inlet is greater than the sum of the pressure of the spring 1 acting on the valve assembly, the weight of the valve assembly, and the weight of the fuel inside the valve assembly, the entire valve assembly moves upward. The fuel is discharged from the multi-functional vent valve through the gap between the valve base 8 and the valve assembly, the gap between the housing 11 and the valve assembly, the spring 1, and the valve outlet.

Claims

1. A multi-functional vent valve for a helicopter fuel system, characterized in that, The multi-functional vent valve includes a spring (1), a valve assembly, a valve base (8), and a housing (11). The valve assembly includes a valve cavity housing (2), a float (3), a float cavity (4), a first sealing ring (5), a valve cavity base (6), a second sealing ring (7), a third sealing ring (9), and a steel ball (10). The valve base (8) is a hollow columnar structure. The bottom end of the valve base (8) is a mounting flange structure, and the upper end of the valve base (8) is provided with an outwardly folded boss structure. The housing (11) is a hollow columnar structure. The boss at the upper end of the valve base (8) is assembled inside the bottom end of the housing (11), and the top end of the housing (11) is the outlet of the multi-functional vent valve. The valve base (8) and the housing (11) form the outer shell of the vent valve. The internal cavity of the valve base (8) and the housing (11) is provided with a spring (1) and a valve assembly. One end of the spring (1) is fixed to the upper part of the housing (11), and the other end is fixed to the upper part of the valve cavity housing (2). The valve assembly is pressed against the valve base (8) under the action of the spring (1). The top of the valve cavity housing (2), the bottom of the valve cavity base (6), and the bottom of the float cavity (4) are all provided with through holes; the float (3) and the steel ball (10) are located inside the float cavity (4); the upper part of the valve cavity base (6) is installed on the top of the valve base (8), the top of the valve cavity base (6) is a downwardly inclined conical surface with through holes, the lower part of the valve cavity housing (2) is installed on the upper part of the valve cavity base (6), the float cavity (4) is installed on the upper part of the valve cavity base (6) and inside the valve cavity housing (2), the bottom of the float cavity (4) is a downwardly inclined conical surface with through holes, the top of the float cavity (4) is open, and the float... (3) Installed in the float cavity (4), the bottom of the float (3) is pressed on the steel ball (10); the float cavity (4) is clamped in the valve cavity housing (2) by N small arms, so that the float cavity (4) is fixed in the valve cavity housing (2), and the float cavity (4) moves together with the valve cavity housing (2) and the valve cavity base (6); the valve cavity housing (2) and the valve cavity base (6) are connected by threads and sealed with sealing ring one (5); the valve cavity base (6) and the valve base (8) are sealed by sealing ring three (9); the valve base (8) and the housing (11) are sealed by sealing ring two (7).

2. The multifunctional vent valve according to claim 1, characterized in that, The range of N is 3-6.

3. The multifunctional vent valve according to claim 1, characterized in that, The gap between the float cavity (4) and the valve cavity shell (2) is 7-10 mm.

4. The multifunctional vent valve according to claim 1, characterized in that, The dimensions of the boss structure at the upper end of the valve base (8) are: outer diameter Ø54 mm, inner diameter Ø32 mm, and thickness 3 mm; The dimensions of the bottom flange structure of the valve base (8) are: outer diameter Ø56 mm, inner diameter Ø32 mm, and thickness 3 mm.

5. The multifunctional vent valve according to claim 1, characterized in that, The valve cavity base (6) has 4-8 through holes with a radius of 5-10 mm. The float cavity (4) has 4-8 through holes with a radius of 5-10 mm.

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