In-flight refueling receptacle for an aircraft

Abstract

The invention relates to a refueling receptacle (50) for an aircraft (10) suitable for being refueled in flight, the receptacle being configured to be fluidically connected to a pipe (54) of the aircraft which is intended to receive a fluid from another aircraft, referred to as a tanker aircraft (12), the receptacle (50) comprising a connection device (60) configured to connect the pipe (54) of the aircraft to a boom (18) of the tanker aircraft (12), the connection device comprising a mechanical coupling system (62) configured to couple the pipe (54) of the aircraft to the boom (18), the receptacle being characterized in that the connection device comprises a pressure regulator (66) arranged downstream of the mechanical coupling system (62) and configured to keep the pressure of the fluid from the tanker aircraft lower than a maximum value.

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION: IN-FLIGHT REFUELING RECEPTACLE FOR AN AIRCRAFT

[0003] TECHNICAL FIELD

[0004] The present invention relates to the general field of aeronautics. More particularly, it relates to an in-flight refueling device for an aircraft, and in particular a refueling receptacle as well as an aircraft comprising such an in-flight refueling receptacle.

[0005] PREVIOUS TECHNIQUE

[0006] The technical background includes, in particular, documents US 4 282 909 Al, FR 3 096 665 Al, US 2012 / 0 049004 Al, US 7458 543 B2 and US 2008 / 0 173 762 Al.

[0007] During a flight, it is known to refuel an aircraft in order to transfer at least one fluid, such as fuel.

[0008] This is the case, for example, of an aircraft that cannot or should not land in an area it is flying over, such as an ocean. The aircraft must then be refueled in flight. This is particularly the case when the volume of fuel it carries reaches a lower threshold.

[0009] During such a refueling operation, a first aircraft, also called the tanker, is equipped with an in-flight refueling system to which a second aircraft, also called the receiver or aircraft to be refueled, connects. The tanker aircraft is usually an airplane, while the aircraft being refueled can be an airplane or a helicopter.

[0010] In-flight refueling involves transferring a fluid, such as fuel, from the refueling aircraft to the aircraft being refueled. Two refueling techniques exist.

[0011] The first method is also known as "probe-and-drogue" in common English. In this case, the in-flight refueling system consists of a hose, designed for fluid transfer and therefore connected to a fluid tank on the tanker aircraft. This hose is unrolled from the first aircraft to the second aircraft, which is located downstream of the first aircraft along a given flight path and is to be refueled. The flexible hose is stabilized by a basket that creates aerodynamic drag, and the receiving aircraft locks a refueling probe onto it. The hose can be unrolled or deployed from a downstream end of the fuselage or wing of the refueling aircraft. Alternatively, the hose can be deployed from a pod, also called a pod, mounted on the ventral side of an aircraft, particularly a fighter jet, or from a pod mounted under the wing of an aircraft, particularly a tanker or fighter jet.

[0012] The second refueling technique is also known as a "flying boom" or "boom system." In this case, the in-flight refueling system consists of a rigid, telescopic boom that the refueling aircraft extends to hook into a receptacle on the receiving aircraft, usually mounted on the receiver's tail. This receptacle is designed to receive the boom's tip during refueling. The boom floats below the tail of the refueling aircraft thanks to ailerons equipped with control surfaces that allow it to be steered. The receptacle has locking mechanisms to keep the boom connected to a conduit that transfers the fluid, such as fuel, from the refueling aircraft to a tank on the refueled aircraft, which is connected to the same conduit.

[0013] Thus, during in-flight refueling, the receptacle mechanically locks the connection between the boom and the fuel tank of the aircraft being refueled, and also opens the refueling line, particularly for fuel, to the aircraft being refueled. It should be noted that the event of "overpressure generation in the refueled aircraft" is considered by aircraft manufacturers to be a catastrophic event.

[0014] Currently, protection against fluid overpressure, particularly fuel overpressure, is provided by the rigid boom itself on the tanker side or by the fuel system of the tanker aircraft.

[0015] No overpressure protection system for fluids, particularly fuel, is integrated into the refueled aircraft. Therefore, refueled aircraft are entirely dependent on the proper functioning of the refueling aircraft's system, which ensures their safety by preventing the downstream fluid pressure, particularly fuel pressure, from exceeding 55 PSI.

[0016] During in-flight refueling, several phenomena can cause fuel overpressure in the refueling line, such as a failure of the tanker's fuel pump, a failure of the tanker's pressure regulation system, a pressure surge when the tanker's pump starts, or a pressure surge when the aircraft is fully refueled (a phenomenon due to increased fuel backpressure in the refueling circuit). Furthermore, the fuel pressure regulation system consists of components that wear out over time, such as springs or an inflated diaphragm housed in the boom to dampen overpressure. Therefore, to ensure long-term reliability and safety, periodic checks of the tanker aircraft's pressure regulation system are necessary.

[0017] The objective of the present invention is therefore to overcome at least some of these drawbacks. Its aim is to provide a solution to at least some of the problems of the prior art, which is simple, effective and economical, in particular, by proposing a receptacle capable of regulating the pressure level of the fluid, in particular fuel, delivered by the refueling aircraft.

[0018] SUMMARY OF THE INVENTION

[0019] To this end, the invention relates to a refueling receptacle for an aircraft adapted to be refueled in flight, the receptacle being configured to be fluidically connected to a line of the aircraft intended to receive a fluid from another aircraft called the refueling aircraft, the receptacle comprising a connection device configured to connect the aircraft line with a boom of the refueling aircraft, the connection device comprising a mechanical coupling system configured to couple the aircraft line with the boom.

[0020] According to the invention, the connection device includes a pressure regulator arranged downstream of the mechanical coupling system and configured to limit the pressure of the fluid coming from the refueling aircraft below a maximum value.

[0021] The invention thus proposes a refueling receptacle capable of overcoming the aforementioned drawbacks.

[0022] To this end, the invention provides a receptacle capable of regulating the pressure level of the fluid, particularly fuel, delivered by the refueling aircraft, for example to a pressure below 55 PSI. The refueling receptacle according to the invention thus directly incorporates a pressure regulation function.

[0023] The invention thus makes it possible to increase the level of safety of in-flight refueling and to reduce maintenance intervals on aircraft, particularly on airplanes.

[0024] The solution proposed by the invention thus makes it possible to implement redundancy in both the refueling aircraft and the refueled aircraft, thereby guaranteeing an optimal level of safety for the refueled aircraft. By redundantly controlling the fuel system, maintenance intervals are extended and also performed more easily on the refueled aircraft. The refueling receptacle, according to the invention, may comprise one or more of the following features, taken individually or in combination with each other in any technically feasible configuration:

[0025] - the mechanical coupling device includes a mechanical locking system configured to hold the refueling aircraft boom in a fixed position relative to the pipeline;

[0026] - the connection device includes a valve arranged between the mechanical coupling system and the pressure regulator and configured to allow the passage of fluid from the boom of the refueling aircraft to the pipeline when the boom is connected to the pipeline and held in the fixed position relative to the pipeline;

[0027] - the receptacle includes a housing containing at least the mechanical coupling system and the pressure regulator;

[0028] - the valve is housed in the casing;

[0029] - the maximum value is equal to 55 PSI;

[0030] - the receptacle includes a pressure sensor configured to measure the pressure of the fluid coming from the refueling aircraft upstream of the pressure regulator and a first controller connected to the pressure sensor and the pressure regulator, the pressure regulator being digitally controlled by the first controller according to the pressure measured by the pressure sensor;

[0031] - the pressure regulator is a mechanical pressure regulator configured to mechanically limit the fluid pressure in order to maintain the fluid pressure below the maximum value;

[0032] - the receptacle includes a monitoring system configured to generate an alarm signal in the event of an anomaly during an in-flight refueling of the aircraft, the monitoring system comprising at least a first pressure sensor configured to measure the fluid pressure upstream of the pressure regulator, a second pressure sensor configured to measure the fluid pressure downstream of the pressure regulator, and a second controller connected to the first and second pressure sensors, the second controller being configured to generate the alarm signal if the fluid pressure measured downstream of the pressure regulator is greater than the maximum value;

[0033] - the monitoring system includes at least one first position sensor configured to measure the position of the mechanical locking system integrated into the mechanical coupling system, the first sensor being connected to the second controller, the second controller being configured to generate the alarm signal in the event of an anomaly in the locking system;

[0034] - the monitoring system includes at least one second position sensor configured to measure the position of the valve, the second sensor being connected to the second controller, the second controller being configured to generate the alarm signal in case of valve blockage;

[0035] - the monitoring system includes at least one flow meter configured to measure the flow of fluid in the line downstream of the pressure regulator, the flow meter being connected to the second controller, the second controller being configured to generate the alarm signal if the measured flow of fluid is greater than a reference value.

[0036] The invention also relates to an aircraft adapted for in-flight refueling comprising at least:

[0037] - a tank configured to receive and store fluid from another aircraft, called a refueling aircraft,

[0038] - a pipe fluidly connected to the reservoir, and

[0039] - a refueling receptacle according to the invention and as described above.

[0040] BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be better understood and other details, features, and advantages of the present invention will become more apparent upon reading the following description of a non-limiting example, with reference to the accompanying drawings in which:

[0042] - Figure 1 represents a schematic view of an aircraft to be refueled equipped with an in-flight refueling receptacle according to the invention during in-flight refueling by a refueling aircraft;

[0043] - Figure 2 is a schematic cross-sectional view of a refueling receptacle according to a first embodiment of the invention equipping the aircraft to be refueled of Figure 1 and suitable for receiving the end of the refueling aircraft's boom;

[0044] - Figure 3 is a schematic view of a second embodiment of a refueling receptacle according to the invention;

[0045] - Figure 4 represents a schematic view of a third embodiment of a refueling receptacle according to the invention;

[0046] Figure 5 is a schematic view of a fourth embodiment of a refueling receptacle according to the invention. Elements having the same functions in the different embodiments have the same reference numerals in the figures.

[0047] In the figures, the scales and proportions are not strictly respected for the purposes of illustration and clarity.

[0048] In the description, and unless otherwise stated, the terms "internal" and "external" are used as non-limiting references to the radial distance from the longitudinal axis around which the lubrication chamber extends, the term "internal" defining an area radially closer to the longitudinal axis of the reducer, as opposed to the term "external".

[0049] DESCRIPTION OF IMPLEMENTATION METHODS

[0050] Figure 1 schematically illustrates a refueling aircraft 10 coupled to a refueling aircraft 12 for in-flight refueling with fluids, particularly fuel. In the example shown, the refueling aircraft 12 and the receiving aircraft 10 are airplanes. Alternatively, the receiving aircraft 10 could be a helicopter or any other aircraft suitable for in-flight refueling. Similarly, the refueling aircraft 12 could be a helicopter or any other aircraft suitable for in-flight refueling.

[0051] For this purpose, the refueling aircraft 12 includes an in-flight refueling system 14 consisting of an element 16, also known by the common English name "boom", extended by a telescopic boom 18. It extends under the rear part of the fuselage of the refueling aircraft 12.

[0052] Element 16 is fixed to the lower rear part of the fuselage of tanker aircraft 12 by a semi-rigid link allowing it some freedom of movement.

[0053] Element 16 is fixed or retractable. It is rigid and orientable relative to the longitudinal axis of the tanker aircraft 12, while remaining generally oriented rearward and downwards. Relative to the longitudinal axis of the tanker aircraft 12, element 16 can tilt downwards, for example in an angular sector extending from 20° to 40°, and laterally from 0° to 10° or 15° on either side of the axis.

[0054] Element 16 has a length between 5 m and 10 m, for example. It is extended by the telescopic pole 18, which can extend over a length of several meters. For example, the total length of element 16 and pole 18 can vary between 15 m and 20 m.

[0055] The attachment of element 16 to the rear of aircraft 12 is a semi-rigid attachment using a ball joint. The orientation of element 16 relative to the axis is achieved by means of movable ailerons 20 controlled by servomotors. The servomotors are controlled from the tanker aircraft 12.

[0056] In the illustrated example, element 16 is guided by fins 20 arranged in a V, but another arrangement of these fins is conceivable, in a T for example.

[0057] The telescopic extension of boom 18 is also controlled from tanker aircraft 12 and can optionally be measured by a rangefinder integrated into telescopic boom 18.

[0058] Thus, during in-flight refueling, the entire assembly of element 16 and boom 18 floats beneath the tail of the tanker aircraft 12 thanks to the ailerons 20 equipped with control surfaces that allow it to be steered. The pilot of the refueled aircraft 10 must approach his aircraft under the tail of the tanker 12, close to the boom 18 which extends behind it, and maintain his speed exactly equal to that of the tanker 12 until the end of the refueling operation.

[0059] It is this inclination, coupled with a choice of telescopic extension of the pole 18, which allows the end of the pole 18 to be positioned exactly in relation to a receptacle 50 provided on the refueled aircraft 10, while the refueled aircraft 10 follows the refueler 12 very closely at the same speed as the latter.

[0060] As is known, the boom 18 has a free distal end 22, also called the glans or nozzle of the boom 18 and commonly known as the "boom nozzle", configured to be inserted into the receptacle 50 of the refueled aircraft 10 so as to form a fluid-tight connection, including a connection to fuel, with the refueling system of the receiving aircraft 10.

[0061] Advantageously, an internal pipe or conduit (not shown) extends through element 16 and boom 18 to the acorn 22 and is configured to provide a fluid supply from the fuselage of the tanker aircraft 12 to the acorn 22. The internal pipe is thus suitable for fluid transfer and includes a first end connected to a fluid source 24 or reservoir of the tanker aircraft 12 and comprising, for example, a tank and a pump, and a second end opposite the first end in the acorn and comprising a fluid connection with the receptacle 50 of the receiving aircraft 10. Such a type of connection is well known to those skilled in the art.

[0062] As is known, the in-flight refueling system 14 of the tanker aircraft 12 generally includes a pressure regulation system 26 arranged downstream of the acorn 22 and configured to avoid fluid overpressures, particularly of fuel, during the in-flight refueling phase by limiting the fluid pressure downstream of the acorn to a threshold value.

[0063] For example, the fluid fitting may include a pressure limiting device. For this purpose, the fitting may include a valve to set the outlet pressure of the fluid fitting to the limit applicable in the environment, for example, 55 PSI.

[0064] The receptacle 50 of the refueled aircraft 10, the subject of the invention, will now be detailed with reference to figures 2 to 5.

[0065] In relation to figure 2 which schematically represents a cross-sectional view of such a receptacle 50 called a refueling receptacle, the receptacle 50 is arranged on the back of the receiving aircraft 10. In the illustrated example, the receptacle is for example arranged flush with the sheets 52 of the fuselage of the aircraft 10.

[0066] The receptacle 50 is configured to be fluidically connected to a line 54 of the receiving aircraft 10 intended to receive fluid from the refueling aircraft 12. Alternatively, the line 54 can be integrated into the receptacle 50 of the receiving aircraft 10.

[0067] Pipe 54 is suitable for transferring fluids, particularly fuel. It comprises a first end 54A connected to a tank 56 of the receiving aircraft 10 and a second end 54B, opposite the first end 54A, and including a fluid connection. The fluid connection of pipe 54 is configured to provide a fluid connection with a fitting on the receiving aircraft, which can cooperate by complementarity.

[0068] The receptacle 50 includes a connection device 60 configured to smoothly connect the aircraft line 54 with the boom 18 of the refueling aircraft 12.

[0069] The receptacle 50 preferably includes an entry housing, with walls 59 generally conical or pyramidal in shape narrowing inwards, so that the end 22 of the pole 18 is naturally guided, when it enters the housing, towards a housing bottom in which the connection device 60 is located.

[0070] The connection device 60 allows the pole 18 to be held in place during the fluid transfer operation.

[0071] For this purpose, the connection device 60 includes a mechanical coupling system 62 known to those skilled in the art and configured to couple the aircraft line 54 with the boom 18. Such a mechanical coupling system 62 includes a mechanical locking system configured to hold the boom 18 of the tanker aircraft 12 in a fixed position relative to the line 54. Such a mechanical coupling and boom locking system is well known to those skilled in the art and will not be described here.

[0072] In addition, the connection device 60 includes a valve 64 arranged downstream of the mechanical coupling system 62. The valve 64 is configured to permit the passage of fluid from the boom 18 of the refueling aircraft 12 to the line 54 of the receiving aircraft 10 when the boom 18 is connected to the line 54 by the mechanical coupling system 62 and held in the fixed position relative to the line by the mechanical locking system.

[0073] According to the invention, the connection device 60 further comprises a pressure regulator 66 arranged downstream of the mechanical coupling system and configured to limit the pressure of the fluid from the refueling aircraft 12 in the line 54 below a maximum value. The maximum value is preferably equal to 55 PSI.

[0074] The valve 64 is arranged between the mechanical coupling system 62 and the pressure regulator 66.

[0075] The receptacle 50 includes a housing 68 containing the mechanical coupling system 62, the valve 64 and the pressure regulator 66.

[0076] Figure 3 schematically represents a receptacle according to a second embodiment of the invention.

[0077] According to this second embodiment, the pressure regulator 66 of the receptacle 50 is of the proportional pressure regulator type 662.

[0078] The receptacle 50 includes a pressure sensor 70 configured to measure the pressure of the fluid coming from the refueling aircraft 12 upstream of the pressure regulator 66.

[0079] Preferably, the pressure sensor 70 is configured to measure the fluid pressure upstream of the pressure regulator 66 and downstream of the valve 64.

[0080] The receptacle also includes a first controller 72 connected to the pressure sensor 70 and the pressure regulator 66. The pressure regulator 662 is digitally controlled by the first controller 72 according to the pressure measured by the pressure sensor 70.

[0081] Figure 4 schematically represents a receptacle according to a third embodiment of the invention.

[0082] According to this third embodiment, the pressure regulator 66 of the receptacle 50 is a mechanical pressure regulator 664 configured to mechanically limit the fluid pressure so as to maintain the fluid pressure below the maximum value Pmax.

[0083] For example, such a pressure regulator 66 may include a diaphragm to provide the acceptable pressure threshold value. This type of pressure regulator advantageously replaces the spring-type mechanical components currently used to regulate pressure in refueling aircraft.

[0084] Figure 5 schematically represents a receptacle according to a fourth embodiment of the invention.

[0085] According to this fourth embodiment, the pressure regulator 66 of the receptacle 50 is a mechanical pressure regulator 664 configured to mechanically limit the fluid pressure so as to maintain the fluid pressure below the maximum value Pmax, as in the third embodiment. Alternatively, the pressure regulator 66 of the receptacle 50 can be of the proportional pressure regulator type 662, like the pressure regulator of the second embodiment illustrated in Figure 3.

[0086] The receptacle 50 also advantageously includes a monitoring system 80 configured to generate an alarm signal S in the event of an anomaly during an in-flight refueling of the aircraft.

[0087] The 80 monitoring system includes at least:

[0088] - a first pressure sensor 82 configured to measure the pressure P1 of the fluid upstream of the pressure regulator 66, and preferably downstream of the valve 64.

[0089] - a second pressure sensor 84 configured to measure the pressure P2 of the fluid downstream of the pressure regulator 66, and

[0090] - a second controller 86 connected to the first and second pressure sensors 82, 84.

[0091] The second controller 86 is configured to generate the alarm signal S if the pressure P1 of the fluid measured downstream of the pressure regulator is greater than the maximum value.

[0092] Advantageously, the 80 surveillance system may also include at least one of the following elements:

[0093] - a first position sensor 88 configured to measure the position or state of the mechanical locking system integrated into the mechanical coupling system 62. The first sensor 88 is connected to the second controller 86. The second controller 86 is configured to generate the alarm signal S in the event of an anomaly in the locking system, for example if it no longer responds or is blocked, in particular in a locked or unlocked position.

[0094] - a second position sensor 89 configured to measure the position of the valve 64, the second sensor 89 being connected to the second controller 86. The second controller 86 is configured to generate the alarm signal S if the valve 64 is blocked, in particular in the open or closed position.

[0095] - a flow meter 90 configured to measure the flow of the fluid in the pipe 54 downstream of the pressure regulator 66, the flow meter 90 is connected to the second controller 86. The second controller 86 is configured to generate the alarm signal S if the measured flow of the fluid is greater than a reference value.

[0096] Advantageously, the combination of the second pressure sensor 84 and the flow meter 90 allows for a more precise diagnosis of possible blockage positions of the valve 64.

[0097] Such a monitoring system 80 integrated into the receptacle advantageously allows for monitoring the various components of the receptacle and thus refines the need for periodic maintenance checks. The intervals for checking the pressure regulation devices on the side of the refueled aircraft 10 and the refueling aircraft 12 can therefore be reduced.

[0098] Naturally, the invention described above is by way of example. It is understood that a person skilled in the art is capable of carrying out different embodiments of the invention without departing from its scope.

[0099] It is emphasized that all features, as they are apparent to a person skilled in the art from the present description, drawings and attached claims, even if in practice they have only been described in relation to other specific features, both individually and in any combinations, may be combined with other features or groups of features disclosed herein, provided that this has not been expressly excluded or that technical circumstances render such combinations impossible or meaningless.

Claims

DEMANDS 1. Refueling receptacle (50) for an aircraft (10) adapted for in-flight refueling, the receptacle being configured to be fluidically connected to a line (54) of the aircraft intended to receive fluid from another aircraft referred to as the refueling aircraft (12), the receptacle (50) comprising a connection device (60) configured to connect the line (54) of the aircraft with a boom (18) of the refueling aircraft (12), the connection device comprising a mechanical coupling system (62) configured to couple the line (54) of the aircraft with the boom (18), the receptacle being characterized in that the connection device includes a pressure regulator (66) arranged downstream of the mechanical coupling system (62) and configured to limit the pressure of the fluid from the refueling aircraft below a maximum value.

2. Refueling receptacle according to claim 1, wherein the mechanical coupling device (62) includes a mechanical locking system configured to hold the boom (18) of the refueling aircraft (12) in a fixed position relative to the pipe (54).

3. Refueling receptacle according to claim 2, wherein the connection device (60) includes a valve (64) arranged between the mechanical coupling system (62) and the pressure regulator (66) and configured to permit the passage of fluid from the refueling aircraft boom to the pipeline when the boom is connected to the pipeline and held in the fixed position relative to the pipeline.

4. Refueling receptacle according to any one of the preceding claims, comprising a housing (68) housing at least the mechanical coupling system (62) and the pressure regulator (66).

5. Refueling receptacle according to claim 4 when it depends on claim 3, in which the valve (64) is housed in the casing (68).

6. Refueling receptacle according to any one of the preceding claims, wherein the receptacle comprises: - a pressure sensor (70) configured to measure the pressure of the fluid coming from the refueling aircraft (12) upstream of the pressure regulator (66), - a first controller (72) connected to the pressure sensor and the pressure regulator, the pressure regulator (66) being digitally controlled by the first controller according to the pressure measured by the pressure sensor.

7. Refueling receptacle according to any one of claims 1 to 5, wherein the pressure regulator (66) is a mechanical pressure regulator (664) configured to mechanically limit the fluid pressure so as to maintain the fluid pressure below the maximum value.

8. Refueling receptacle according to claim 6 or 7, wherein the receptacle comprises a monitoring system (80) configured to generate an alarm signal (S) in the event of an anomaly during in-flight refueling of the aircraft, the monitoring system comprising at least: - a first pressure sensor (82) configured to measure the fluid pressure upstream of the pressure regulator, - a second pressure sensor (84) configured to measure the fluid pressure downstream of the pressure regulator, - a second controller (86) connected to the first and second pressure sensors, the second controller being configured to generate the alarm signal if the fluid pressure measured downstream of the pressure regulator is greater than the maximum value.

9. Refueling receptacle according to claim 8 when it depends on claim 3, wherein the monitoring system comprises at least one element from: - a first position sensor (88) configured to measure the position of the mechanical locking system integrated into the mechanical coupling system (62), the first sensor being connected to the second controller, the second controller being configured to generate the alarm signal in case of an anomaly in the locking system; - a second position sensor (89) configured to measure the position of the valve (64), the second sensor being connected to the second controller, the second controller being configured to generate the alarm signal in case of valve blockage; - a flowmeter (90) configured to measure the flow of fluid in the line downstream of the pressure regulator, the flowmeter being connected to the second controller, the second controller being configured to generate the alarm signal if the measured flow of fluid is greater than a reference value.

10. Aircraft (10) adapted for in-flight refueling comprising at least: - a tank (56) configured to receive and store a fluid from another said refueling aircraft (12), - a conduit (54) fluidly connected to the reservoir (56), and - a refueling receptacle (50) according to any one of the preceding claims.

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