HYDRAULIC CONTROL DEVICE FOR A THRUST REVERSER

Abstract

Hydraulic control device (10) for a thrust reverser (12) of an aircraft propulsion unit nacelle, this device (10) comprising: - a hydraulic motor (26), - a first solenoid valve (28), called an isolation solenoid valve, comprising a fluid inlet (28a) capable of being connected to a fluid source (24) of an aircraft, - a fluid discharge line (34) which is equipped with a non-return valve (32), - a hydraulic circuit (36) for connecting the motor (26) to the isolation solenoid valve (28) and to the discharge line (34). Figure for the abstract: Figure 1

Description

Title of the invention: HYDRAULIC CONTROL DEVICE FOR A THRUST REVERSER Technical field of the invention

[0001] The present invention relates in particular to a hydraulic control device for a thrust reverser of an aircraft propulsion unit, as well as a propulsion unit comprising such a device. Technical background

[0002] An aircraft propulsion unit generally comprises a nacelle forming a generally circular outer envelope, comprising inside a turbomachine arranged along the axis of revolution of this nacelle.

[0003] The turbomachine receives fresh air from the upstream or front side, and rejects from the downstream or rear side the hot gases from the combustion of the fuel, which provide a certain thrust.

[0004] Double-flow turbomachines comprise fan blades which are arranged upstream of an engine or gas generator and inside the nacelle. These fan blades generate a significant secondary flow of cold air in an annular vein which extends between the engine and the nacelle, and which adds high thrust.

[0005] Certain nacelles include a thrust reversal system which at least partially closes the annular cold air stream, and rejects the secondary flow forward in order to generate braking thrust for the aircraft.

[0006] A known type of thrust reverser, presented in particular by document FR-A1-2 758 161, comprises rear movable cowls called "Trans-Cowl", sliding axially towards the rear under the effect of jacks by deploying flaps in the annular vein in order to close most of this vein. The flaps return the flow of cold air radially towards the outside by passing through grilles uncovered by the movable cowls during their sliding, comprising blades which direct this flow towards the front.

[0007] A thrust reverser is powered by a device of the TRAS type, which is the acronym for the English expression Thrust Reverser Actuation System.

[0008] Originally, grid thrust reversers were powered by a pneumatic motor using pressure supplied by the compressor stages of the turbomachine. In this technology, the pneumatic motor drives actuators via shafts, each comprising a mechanical cylinder using a ball screw-nut system, which makes it possible to synchronize all of these cylinders to obtain a translation of the cowls.

[0009] This type of engine is no longer produced because it poses several problems, in particular a significant size of the pneumatic motor, an available pressure which varies greatly depending on the speed of the turbojet, a compressibility of the air supplying the energy which does not provide sufficiently reactive control of the engine, and dependence on environmental conditions, such as frost.

[0010] Another known type of motorization comprises an electric motor which, as with the pneumatic motor, drives a kinematic chain driving the different actuators in a synchronized manner. This solution requires the supply of significant electrical power that not all aircraft are capable of providing.

[0011] Another known type of motorization comprises several linear hydraulic actuators powered by a source of pressurized fluid, having internal screws which allow synchronization of these different actuators. This solution is relatively heavy, complicated, and consumes a lot of hydraulic flow from the aircraft.

[0012] Another known type of motorization uses a single hydraulic machine that motorizes a kinematic chain synchronously driving the different actuators. However, for these hydraulic solutions, in order to obtain a high torque for starting the hydraulic motor and the start of the reverser movement, as well as for braking these elements at the end of the stroke, a relatively large displacement of the hydraulic motor is then required. In particular, a sudden end of stroke or interruption of stroke would cause impacts and the application of a significant force on the system and on the structure which must be avoided. The solution to this problem is a variable displacement hydraulic motor, as described in document FR-A1-3 016 928.

[0013] Another known type of motorization consists of using a hybrid motorization, for example hydraulic and electric, as described in document WO-Al-2011 / 004095.

[0014] The present invention relates to a hydraulic motorization.

[0015] The source of hydraulic energy for the operation of a hydraulic control device of a thrust reverser comes from the aircraft. A control device of this type is therefore highly dependent on the hydraulic energy available from the aircraft.

[0016] The pressure levels of hydraulic circuits in an aircraft are not always the same. On long-haul flights, aircraft manufacturers tend to favor relatively high aircraft hydraulic pressure levels, generally 345 bars (approximately 5000 psi). On the contrary, on short or medium-haul flights and on business jets, aircraft manufacturers tend to favor lower pressures, generally 207 bars (approximately 3000 psi).

[0017] In all cases, the aircraft manufacturer seeks to reduce the flow rate sampling hy hydraulics of the control device on the aircraft hydraulic network, so as to reduce the hydraulic footprint of the device (fluid volume, pipe size, etc.).

[0018] Among the hydraulic control devices, there are three main families of TRAS, the hydraulic devices in 207 bars (approximately 3000 psi) for door thrust reverser applications (business aircraft type), and the hydraulic devices in 207 bars (approximately 3000 psi), 276 bars (approximately 40000 psi), or 345 bars (approximately 5000 psi) for Trans-Cowl applications (commercial aircraft type).

[0019] The present invention aims to provide an improved hydraulic control device which can be used for any hydraulic application, and in particular for 206.84 bar (3000 psi) or 344.74 bar (5000 psi) applications, and for any type of thrust reverser architecture (Trans-Cowl type, with doors, with moving grids, etc.). Summary of the invention

[0020] According to a first aspect, the invention relates to a hydraulic control device for a thrust reverser of an aircraft propulsion unit nacelle, this device comprising:

[0021] - a hydraulic motor capable of operating as a motor and generator, this motor comprising an output shaft capable of driving a moving element of a thrust reverser, this engine further comprising a first fluid port and a second fluid port,

[0022] - a first solenoid valve, called an isolation solenoid valve, comprising an inlet of fluid capable of being connected to a fluid source of an aircraft, the isolation solenoid valve further comprising a first fluid port and a second fluid port, the solenoid valve being able to adopt a first position in which its first port is connected to its second port, and a second position in which its inlet is connected to the first port,

[0023] - a fluid discharge line which is equipped with a non-return valve and which is connected to the second port of the solenoid valve, and

[0024] - a hydraulic circuit connecting the engine to the isolation solenoid valve and to the line discharge, and more particularly from the ports of the hydraulic motor to the first port of the isolation solenoid valve and to the discharge line, this hydraulic circuit comprising a second solenoid valve comprising four ports connected respectively to the first port of the isolation solenoid valve, to the first and second ports of the motor, and to the discharge line, the second solenoid valve being capable of adopting at least three distinct positions:

[0025] - a first position in which its first port is isolated, and its second, third and fourth ports are connected together,

[0026] - a second position in which its first and second ports are connected together, and its third and fourth ports are connected together, and

[0027] - a third position in which its first and third ports are connected together, and its second and fourth ports are connected together,

[0028] characterized in that the device further comprises a control circuit for the second solenoid valve, called a proportional solenoid valve, this control circuit being connected to position sensors of the mobile element of the thrust reverser and being configured to control the second solenoid valve so as to control the distribution and the flow rate of fluid delivered to the engine as a function of the position of the mobile element of the thrust reverser.

[0029] The first aspect of the invention called "open loop" consists of controlling the second solenoid valve called proportional valve or solenoid valve as a function of the signals received from the position sensor(s) of the moving element of the thrust reverser. It is thus understood that the pressure and the flow rate of the fluid which will supply the engine is a direct function of the signals transmitted by the sensor(s).

[0030] The advantages of the “open loop” include: the simplicity of the order; flow regulation in order to maintain a speed in accordance with the setpoint via hydraulics alone without the intervention of a control loop on the control; etc.

[0031] The position of the thrust reverser position sensors is not limiting. They can be located on the engine or its rotation shaft, on the drive train with the downstream cylinders, on the thrust reverser directly, etc.

[0032] The device according to the invention may also have one or more of the following characteristics, taken alone or in combination with each other: the first port of the isolation solenoid valve is connected to the first port of the proportional solenoid valve by a pressure balance which has the function of providing a constant fluid flow rate to the proportional solenoid valve regardless of the fluid pressure delivered by the isolation solenoid valve; the second and third ports of the proportional solenoid valve are respectively connected to the first and second ports of the motor by two pipes, a bypass valve being connected to the pipes and being able to adopt a first position in which the pipes are isolated from each other, and a second position in which the pipes are connected together; the switching of the solenoid valve, from its first to its second position, allows for example to carry out maintenance tasks by putting the motor in hydraulic short-circuit; the bypass valve can be a solenoid valve or a hydraulically piloted valve;

[0033] — a pressure selector is connected to the pipes and has the function of comparing the pressures of two fluids and let the fluid with the highest pressure pass;

[0034] — the connecting line from the second port of the motor to the third port of the solenoid valve proportional includes a pressure balancing valve which has the function of regulating the fluid pressure; - the device further comprises a hydraulic system for braking the output shaft of the motor or of a reducer connected to this output shaft, this braking system being connected to the first port of the isolation solenoid valve;

[0035] — the braking system is further connected to said pressure balancing valve; - the engine is of the variable displacement type and is associated with a system for controlling its displacement which comprises a third solenoid valve, called the displacement solenoid valve, which comprises three ports connected respectively to the first port of the isolation solenoid valve, to the engine, and to the evacuation line, the displacement solenoid valve being able to adopt a first position in which the first and second ports are connected together so as to impose one displacement on the engine, and a second position in which the second and third ports are connected together so as to impose another displacement on the engine; the invention makes it possible in particular to have two distinct displacements responding to particular usage scenarios; first position: increase the displacement of the engine to its high value so as to maximize the available mechanical torque of the engine.This position is applied under the effect of a solenoid valve command in specific use cases and stroke positions so as to only use it when necessary for example; second position: reduce the engine displacement to its low value so as to minimize flow consumption. This position is that of rest of the valve (in the absence of command) thus allowing to have the lowest possible flow consumption when fast speeds are requested for example; the solution thus makes it possible to meet the right need while limiting the complexity of the system; . - the first port of the displacement solenoid valve is connected by a pressure reducer and nozzle system to an additional port of the engine, this system being capable of supplying the engine for the purpose of lubricating its internal components and purging it; - the displacement solenoid valve is controlled by said control circuit; - the engine further comprises a leak discharge port which is connected by a drainage line to the discharge line, said drainage line comprising for example a filter and a pressure relief valve; the leak discharge port can alternatively be connected directly to an aircraft interface; the interest is in particular to reduce the number of external hydraulic interfaces with the aircraft circuit; a first non-return valve is mounted between one of the pipes and the drainage line, and a second non-return valve is mounted between the other of the pipes and the drainage line, each of these valves authorizing the passage of fluid from the drainage line to the corresponding pipe, and not the reverse; this configuration is particularly advantageous when combined with the drainage line, but could alternatively be used independently;

[0036] — a first pressure relief valve is mounted between one of the pipes and the line drainage, and a second pressure relief valve is mounted between the other of the pipes and the drainage line, each of these pressure relief valves being capable of allowing fluid to pass from the corresponding pipe to the drainage line in the event of overpressure in this drainage line;

[0037] — the discharge line comprises a non-return valve and / or an accumulator;

[0038] — the proportional solenoid valve is controlled by a control circuit by im pulse width modulated or PWM type;

[0039] — the control circuit is integrated in a FADEC box, or in a computer dedicated analog or digital.

[0040] The present invention also relates to a propulsion assembly for an aircraft, comprising a device as described above.

[0041] The present invention also relates to a method for hydraulically controlling a thrust reverser of an aircraft propulsion unit nacelle, by means of a device as described above, the method comprising a step of controlling the proportionality solenoid valve as a function of signals emitted by the position sensors of the mobile element of the thrust reverser.

[0042] According to a second aspect, the invention relates to a hydraulic control device for a thrust reverser of an aircraft propulsion unit nacelle, this device comprising:

[0043] - a hydraulic motor capable of operating as a motor and generator, this motor comprising an output shaft capable of driving a moving element of a thrust reverser, this engine further comprising a first fluid port and a second fluid port,

[0044] - a first solenoid valve, called an isolation solenoid valve, comprising an inlet of fluid capable of being connected to a fluid source of an aircraft, the isolation solenoid valve further comprising a first fluid port and a second fluid port, the solenoid valve being able to adopt a first position in which its inlet is connected to the first port, and a second position in which its first port is connected to its second port,

[0045] - a fluid discharge line which is equipped with a non-return valve and which is connected to the second port of the solenoid valve, and

[0046] - a hydraulic circuit connecting the engine to the isolation solenoid valve and to the line discharge, and more particularly from the ports of the hydraulic motor to the first port of the isolation solenoid valve and to the discharge line, this hydraulic circuit comprising a second solenoid valve comprising four ports connected respectively to the first port of the isolation solenoid valve, to the first and second ports of the motor, and to the discharge line, the second solenoid valve being capable of adopting at least three distinct positions:

[0047] - a first position in which its first port is isolated, and its second, third and fourth ports are connected together,

[0048] - a second position in which its first and second ports are connected together, and its third and fourth ports are connected together, and

[0049] - a third position in which its first and third ports are connected together, and its second and fourth ports are connected together,

[0050] characterized in that the device further comprises:

[0051] - at least one motion or position sensor associated with the output shaft of the motor, and capable of emitting a signal enabling the rotation speed of this shaft to be determined, and

[0052] - a control circuit for the second solenoid valve, this control circuit being connected said at least one sensor and being configured to control the second solenoid valve, called servovalve, according to the signal emitted by said at least one sensor so as to control the distribution and the flow rate of fluid delivered to the motor by the second solenoid valve according to the rotation speed of the output shaft of the motor.

[0053] The second aspect of the invention called "closed loop" consists of controlling the second solenoid valve called servo valve as a function of the signals received from the position sensor(s). It is thus understood that the flow rate of the fluid which supplies the motor is directly a function of the signals transmitted by the sensor(s). The state of the system is estimated from the sensor(s) making it possible to regulate the control of the system so as to follow the expressed instruction. This control can be done in speed or in position (trajectory tracking).

[0054] The advantages of the “closed loop” include: - the robustness of the control via the servocontrol; - the modularity of the control adjustment compared to an open loop solution.

[0055] In the first aforementioned position of the solenoid valve, the connection of the ports to be put in place depends on the needs of covering and uncovering at zero of the solenoid valve to ensure the best performance of the circuit.

[0056] The device according to the invention may also have one or more of the following characteristics, taken alone or in combination with each other: - said at least one motion sensor is a position, speed or acceleration sensor; - the control circuit is integrated into a FADEC box, or into a dedicated analog or digital computer; - the control circuit is integrated into an independent electronic box, analog or digital;

[0057] - the engine is of the variable displacement type and is associated with a control system of its displacement which includes a third solenoid valve, called displacement solenoid valve, which includes three ports connected respectively to the first port of the isolation solenoid valve, to the engine, and to the evacuation line, the displacement solenoid valve being able to adopt a first position in which the first and second ports are connected together so as to impose a displacement on the engine, and a second position in which the second and third ports are connected together so as to impose another displacement on the engine;

[0058] — the first port of the displacement solenoid valve is connected by a relief valve pressure to an additional port of the engine, this pressure relief valve being capable of supplying the engine for the purpose of lubricating its internal components and purging it;

[0059] — the displacement solenoid valve is controlled by said control circuit; - the engine further comprises a leak discharge port which is connected by a drainage line to the discharge line, said drainage line comprising for example a filter and a pressure relief valve; - the second and third ports of the proportional solenoid valve are respectively connected to the first and second ports of the motor by two pipes, a bypass valve being connected to the pipes and being able to adopt a first position in which the pipes are isolated from each other, and a second position in which the pipes are connected together;

[0060] — a first non-return valve is mounted between one of the pipes and the line of drainage, and a second non-return valve is mounted between the other of the pipes and the drainage line, each of these valves allowing the passage of fluid from the drainage line to the corresponding pipe, and not the other way around;

[0061] — a first pressure relief valve is mounted between one of the pipes and the line drainage, and a second pressure relief valve is mounted between the other of the pipes and the drainage line, each of these pressure relief valves being capable of allowing fluid to pass from the corresponding pipe to the drainage line in the event of overpressure in this drainage line; - the discharge line includes a non-return valve and / or an accumulator; - the device further comprises a hydraulic shaft braking system output of the motor or a reducer connected to this output shaft, this braking system being connected to the first port of the isolation solenoid valve, or even to said pressure balancing valve; - said control circuit receives signals from at least some of the following elements: the isolation solenoid valve, the second solenoid valve, and sensors of the moving element of the thrust reverser.

[0062] The present invention also relates to a propulsion assembly for an aircraft, comprising a device as described above.

[0063] The present invention also relates to a method for hydraulically controlling a thrust reverser of an aircraft propulsion unit nacelle, by means of a device as described above, the method comprising a step of controlling the servo valve as a function of signals emitted by at least one movement or position sensor.

[0064] The characteristics of the first aspect can be combined with those of the second aspect, and vice versa. Brief description of the figures

[0065] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

[0066] [Fig-1] [Fig.l] is a very schematic view of a thrust reverser of a aircraft propulsion unit and a hydraulic control device for this thrust reverser;

[0067] [Fig.2] [Fig.l] is a very schematic view of a hydraulic control device for a thrust reverser, according to a first aspect of the invention;

[0068] [Fig.3] [Fig.3] is a very schematic view of a hydraulic control device for a thrust reverser, according to an alternative embodiment of the first aspect of the invention;

[0069] [Fig.4] [Fig.4] is a very schematic view of a hydraulic control device for a thrust reverser, according to a second aspect of the invention;

[0070] [Fig.5] [Fig.5] is a very schematic view of a hydraulic control device for a thrust reverser, according to an alternative embodiment of the second aspect of the invention;

[0071] [Fig.6] [Fig.6] is a very schematic view of a hydraulic control device for a thrust reverser, according to an alternative embodiment of the second aspect of the invention;

[0072] [Fig.7] [Fig.7] is a very schematic view of a hydraulic control device for a thrust reverser, according to an alternative embodiment of the second aspect of the invention;

[0073] [Fig.8] [Fig.8] is a very schematic view of a hydraulic control device for a thrust reverser, according to another alternative embodiment of the second aspect of the invention. Detailed description of the invention

[0074] [Fig. 1] shows a device 10 for hydraulic control of a thrust reverser 12 of the Trans-Cowl type.

[0075] The invention is applicable to different types of inverters, for example those with sliding grids, membrane or others. Furthermore, [Fig.l] should not be considered as limiting the invention to a particular configuration of Trans-Cowl and relates for example to Trans-Cowls not linked to 6 o'clock (6 o'clock by analogy with the dial of a clock).

[0076] The invention makes it possible to move a mobile element of a thrust reverser 12, in particular a cowl translating downstream (Trans-Cowl) or a pivoting door to close the vein and redirect the flow upstream. In summary, it is a mobile element of the thrust reverser 12 which is moved, the reverser 12 also comprising fixed elements. It is this mobile element which is illustrated in the figures.

[0077] In a known manner, the thrust reverser 12 comprises mechanical actuators 14 (the number of which is not limiting), of the ball screw type for example, which make it possible to obtain the translation of a threaded rod, from the rotation of this rod inside a fixed thread.

[0078] The actuators 14 are intended to slide the cover of a thrust reverser 12 which equips the nacelle of an aircraft propulsion unit.

[0079] The actuators 14 are spaced angularly in a regular manner at the periphery of the nacelle, so as to allow a balanced distribution of the actuating forces of the cowl of the thrust reverser 12.

[0080] These actuators 14 are connected to each other by flexible transmission shafts 16, commonly called “flexshafts”, allowing mutual driving of the rotating threaded rods of these actuators 14.

[0081] More specifically, as shown in [Fig.l], a first flexible transmission shaft 16a connects the first actuator 14a to the second actuator 14b, and a second flexible transmission shaft 16b connects the second actuator 14b to the third actuator 14c. This configuration is not, however, limiting.

[0082] A manual control device 18 makes it possible to drive the transmission shafts 16 directly by a control handle in order to maneuver the acc- 14 donors in the event of manual maintenance, for example, whether the engine is broken down or not. This ensures that intervention or maintenance can be carried out in all cases.

[0083] The thrust reverser 12 or its drive system may be equipped with several sensors, such as position sensors 20, and may be equipped with locks 22 for locking the actuators 14 in a certain position, etc.

[0084] The hydraulic control device 10 is simplified in [Fig.l].

[0085] This device 10 is said to be hydraulically generated, in the sense that it takes its source of hydraulic pressure 24 from the main hydraulic circuit of the aircraft.

[0086] The device 10 comprises a hydraulic motor 26 which is capable of operating as a motor to actuate the drive system of the thrust reverser 12, and as a generator by receiving mechanical power from the thrust reverser 12 in particular when braking its movement.

[0087] The device 10 receives the fluid from the hydraulic pressure source 24, passing through an isolation solenoid valve 28 which is open in an activated position to supply the hydraulic motor 26, and which is closed in the absence of a signal in order to ensure safety, by putting the motor 26 in communication with a reservoir 30 at the pressure of the aircraft reservoir.

[0088] The solenoid valve 28 thus comprises an inlet 28a connected to the source 24, a first port 28b connected to a port 26a of the engine 26, and a second port 28c connected to the tank 30.

[0089] The motor 26 comprises another port 26b which is connected with the port 28b to the container 30, for example via a non-return valve 32. More precisely, the port 26b of the motor 26 is connected with the port 28c of the solenoid valve 28 to a discharge line 34 comprising the non-return valve 32 and connected to the tank 30.

[0090] Depending on the operating mode of the motor 26, as a motor or generator, the ports 26a, 26b are respectively a fluid inlet and outlet, or the reverse.

[0091] The ports 26a, 26b of the motor 26 are connected to the solenoid valve 28 and to the container 30 or to the non-return valve 32 by a hydraulic circuit 36 ​​schematically represented by a rectangle. This hydraulic circuit 36 ​​connects the motor 26 to the isolation solenoid valve 28 and to the discharge line 34.

[0092] Circuit 36 ​​makes it possible to distribute the fluid admitted by the solenoid valve 28 to the motor 26 and from the motor 26 to the evacuation line 34.

[0093] Figures 2 and 3 illustrate a first aspect of the invention called "open loop", and Figures 4 to 8 illustrate a second aspect of the invention called "closed loop".

[0094] In these figures 2 to 8, the elements which have already been described in the above are designated by the same reference numbers.

[0095] In Figures 2 to 8, the motor 26 includes an output shaft 38 which drives the drive system of the thrust reverser 12 via a mechanical reducer 40. The output shaft 38 or the reducer 40, or any other mechanical element rotating downstream of the engine 26, can be associated with a hydraulically actuated braking system 42, which is connected to the control device 10.

[0096] This braking system 42 comprises, for example, stacked brake discs, arranged at the end of the line of flexible shafts 16, and can be controlled by a hydraulic cylinder comprising a load spring which constantly keeps the brake closed in the absence of hydraulic pressure. This braking system can be dry or wet.

[0097] In Figures 2 to 8, the hydraulic circuit 36 ​​includes a second solenoid valve 44 which has four ports 44a-44d.

[0098] The first port 44a is connected to the port 28b of the isolation solenoid valve 28.

[0099] The second and third ports 44b, 44c are connected to the first and second ports 26a, 26b of the motor 26.

[0100] The fourth port 44d is connected to the discharge line 34.

[0101] This second solenoid valve 44 is capable of adopting at least three distinct positions:

[0102] - a first position in which its port 44a is isolated, and its other ports 44b-44d are connected together,

[0103] - a second position in which its ports 44a, 44b are connected together, and its ports 44c, 44d are connected together, and

[0104] - a third position in which its ports 44a, 44c are connected together, and its ports 44b, 44d are connected together.

[0105] In the second position, port 26a of motor 26 is connected to pressure source 24, and port 26b of the motor is connected to discharge line 34. Motor 26 operates in motor mode.

[0106] In the first position, corresponding to a rest position, the motor 26 is powered so as to ensure the desired pressure balance during and the dynamic transitions to the other two positions. This is ensured by the definition of the laws of uncovering and covering of the ports of the valve 44.

[0107] In the third position, port 26b of motor 26 is connected to pressure source 24, and port 26a of the motor is connected to discharge line 34. Motor 26 operates in generator mode.

[0108] The solenoid valve 44 can take a set of positions depending on the control current. The three positions mentioned above are extreme positions: solenoid valve fully open in one direction or the other, neutral position. However, the opening of the valve, in one direction or the other, can be done between the neutral position and the extreme positions described.

[0109] The solenoid valves 28 and 44 are by definition electrically controlled valves or electronic, that is to say valves which are electrically controlled via a control circuit Cl. The solenoid valves 28, 44 can be controlled by a single control circuit Cl, by independent control circuits Cl, Cl', or by sub-modules Cl 1, C12 independent of the same control circuit Cl (see [Fig.2]).

[0110] The or each control circuit Cl is for example an electronic circuit or software integrated into an electronic box.

[0111] [Fig.2] illustrates a first embodiment of a hydraulic control device 10 and in particular of its hydraulic circuit 36.

[0112] The particularity of this device 10 is the fact that the solenoid valve 44 is a proportional solenoid valve and the fact that the control circuit C1 is connected to the aforementioned sensors 20 of the position of the thrust reverser.

[0113] This circuit C1 is configured to control the solenoid valve 44 so as to control the distribution and the flow rate of fluid delivered to the engine 26 as a function of the position of the thrust reverser.

[0114] According to the open loop principle, the device self-regulates hydraulically in order to maintain a rotation speed of the motor identical to the command. The proportional solenoid valve 44 has the function of distributing the flow to the ports of the motor. Depending on the current applied, it opens proportionally to allow fluid to pass upstream. Coupled with a pressure balance, it is capable of desensitizing the forces seen by the motor.

[0115] Advantageously, the solenoid valve 44 is controlled by the circuit C1 by pulses of modulated width, that is to say by a control of the PWM type (acronym for Pulse Width Modulation).

[0116] The circuit Cl can be integrated into a FADEC box or can be remote from the FADEC box.

[0117] In the example shown, the port 28b of the solenoid valve 28 is connected to the port 44a of the solenoid valve 44 by a pressure balance 46 which has the function of providing a constant fluid flow rate to the solenoid valve 44 regardless of the pressure of the fluid delivered by the solenoid valve 28.

[0118] Port 28b of solenoid valve 28 may also be connected to braking system 42.

[0119] The ports 44b, 44c of the solenoid valve 44 are respectively connected to the ports 28a, 28b of the motor by two pipes 48, 50.

[0120] A bypass valve 54 may be connected to these lines 48, 50 and is capable of adopting a first position in which the lines 48, 50 are isolated from each other, and a second position in which the lines are connected together. In normal operation and by default, the valve 54 is in the first position. The valve 54 is put in the second position to isolate the motor 26 during a maintenance for example.

[0121] A pressure selector 56 can be connected to the lines 50, 52 and has the function of comparing the pressures of two fluids and allowing the fluid with the highest pressure to pass.

[0122] The pipe 52 connecting the port 26b of the motor 26 to the port 44c of the solenoid valve 44 may comprise a pressure balancing valve 57 which has the function of regulating the pressure of the fluid, in particular during operating modes where the load downstream of the motor 26 causes the motor 26 to operate as a hydraulic generator (increase in pressure in the pipe 52).

[0123] The braking system 42 may include a fluid return line 42a which is connected to the balancing valve 57.

[0124] The balancing valve 57 is controlled by the pressure of the pipe 50 in order to automatically adapt a restriction of passage of the fluid on the pipe 52 when the engine operates as a generator, as a function of its output pressure as well as the pressure of the pipe which supplies it. This automatically produces braking of the engine 26 working as a generator, in order to dissipate braking power in the pressure return to the reservoir 30 by means of the pressure balances imposed in the circuit.

[0125] The function of this valve 57 is to make the device insensitive to driving by an external load by preventing the inversion of the pressure delta at the motor terminals.

[0126] According to the open loop principle, the device self-regulates hydraulically by means of the pressure balance 46, the pressure selector 56, and the balancing valve 57 in order to maintain a rotation speed of the motor identical to the command.

[0127] [Fig. 3] illustrates an alternative embodiment of a hydraulic control device 10 and in particular of its hydraulic circuit 36.

[0128] The solenoid valve 44 of this circuit 36 ​​is a proportional solenoid valve as described above.

[0129] The circuit 36 ​​of [Fig.3] is similar to that of [Fig.2] and differs essentially in that the motor 26 is of the variable displacement type. The motor 26 is thus associated with a system 58 for controlling its displacement which comprises a solenoid valve 60, called the displacement solenoid valve.

[0130] This solenoid valve 60 comprises three ports 60a-60c.

[0131] The first port 60a is connected to the port 28b of the solenoid valve 28.

[0132] The second port 60b is connected to the engine 26 for the purpose of modifying its displacement. The change in displacement of the engine 26 is therefore hydraulically controlled.

[0133] The third port 60c is connected to the evacuation line 34.

[0134] The solenoid valve 60 is capable of adopting a first position in which the ports 60a, 60b are connected together, and a second position in which ports 60b, 60c are connected together.

[0135] The displacement of the engine 26 is modified when the solenoid valve 60 is in its first position. When the solenoid valve 60 is in the second position, the displacement of the engine 26 remains fixed.

[0136] The displacement solenoid valve 60 is preferably controlled by the control circuit CL

[0137] The displacement of the engine 26 is intended to be adjusted according to the loads and the target speed, in order to limit the flow consumption and adjust the torque capacity to just what is necessary.

[0138] The cylinder capacity control law can be based on three separate pieces of information, namely the position of the thrust reverser 12, the engine speed of the aircraft making it possible to define the expected loading level (including maintenance aspects), and the direction of transit (opening / closing in order to choose the appropriate cylinder capacity setting. The surrounding temperature can constitute additional information that can be used for cylinder capacity control.

[0139] Monitoring the aircraft profile in relation to the cylinder capacity adjusted by the adjustment law to just what is necessary automatically makes it possible to limit the flow rate consumed.

[0140] The circuit Cl therefore commands at the start of the transit for cases of expected heavy loads (high aircraft engine speed) a switch to large displacement. The switch is made back to small displacement from the predefined transit position.

[0141] By this displacement adjustment feature, it is thus possible to limit the flow consumption by switching back to small displacement before the speed increases significantly.

[0142] The objective is also to limit the maximum torque to best accommodate the various potential failure cases in order to size the system and the structure of the inverter as needed.

[0143] The port 60a of the solenoid valve 60 can be connected by a pressure reducing device with nozzle 61 to an additional port 26c of the motor 26. The supply of the valve 61 can be done downstream of the solenoid valve 28 or at the level of other tappings. The desired function for the valve 61 is to be able to supply the motor with flow and pressure (reduced compared to the nominal) so as to lubricate the internal components of the motor and purge it in order to increase its service life and ensure its operation

[0144] The engine 26 may further comprise a leak vent port 26d which is connected by a drainage line 62 to the vent line 34.

[0145] This drainage line 62 may include a filter 64 and a pressure relief valve 66.

[0146] Alternatively, the leak evacuation port 26 can be connected directly to an aircraft interface (see [Fig.2]).

[0147] Check valves 68, 70 may be mounted between the lines 50, 52 and the drainage line 62. A first check valve 68 is mounted between the line 50 and the line 62 to allow only the passage of fluid from the line 62 to the line 50. A second check valve 70 is mounted between the line 52 and the line 62 to allow only the passage of fluid from the line 62 to the line 52.

[0148] The return of these elements (line 34) makes it possible to have a leak recycling circuit making it possible to take advantage of these unwanted volumes available to reinject them into the circuit when necessary via the valves 68, 70.

[0149] The non-return valves 68, 70 each comprise, for example, a calibrated setting spring and make it possible to avoid excess pressure in the drainage line 62 by discharging the fluid into one of the pipes 50, 52.

[0150] Pressure relief valves 72, 74 may be mounted between the lines 50, 52 and the drainage line 62. A first pressure relief valve 72 is mounted between the line 50 and the line 62, and a second pressure relief valve 74 is mounted between the line 52 and the line 62.

[0151] The discharge line 34 may comprise a non-return valve 32 and an accumulator 76 or compensator.

[0152] In the event of an abnormal decrease in pressure in one of the pipes 50, 52, the valve 68, 70 of the corresponding pipe discharges a volume of fluid to the drainage line 62. The leaks from the motor 26 constitute a part (or even all) of the restitution volume. If necessary, the accumulator 76 makes it possible to restore an additional volume when the available leaks are insufficient.

[0153] The role of the accumulator 76 is to store a volume of pressurized fluid available for restitution in extreme operating scenarios where the drainage mentioned above would not be sufficient.

[0154] In the event of an abnormal increase in pressure in one of the lines 50, 52, the pressure relief valve 72, 74 of the corresponding line allows a volume of fluid to be discharged towards the drainage line 62 (at low pressure). The pressure in the engine 26 is not increased by this sudden discharge.

[0155] [Fig.4] illustrates another embodiment of a hydraulic control device 10 and in particular of its hydraulic circuit 36.

[0156] The particularity of this device 10 is the fact that the solenoid valve 44 is a servovalve and the fact that the control circuit C1 is connected to at least one movement or position sensor 80 associated with the output shaft 38 of the motor 26.

[0157] This circuit Cl is configured to control the solenoid valve 44 so as to control the distribution and the flow rate of fluid delivered to the motor 26 as a function of the position of the thrust reverser.

[0158] As an example, the control of the solenoid valve 44 is constructed by comparing the speed measurement detected by the sensor 80 with the initial speed profile which depends on the position of the output shaft 38. As a variant, trajectory tracking with thresholds on the speeds could be carried out.

[0159] The movement or position sensor 80 is capable of emitting a signal depending on the rotation speed of the shaft 38. It may be a position, speed or acceleration sensor for example. The important thing is to have information making it possible to return to the rotation speed of the shaft 38 via mathematical operations if necessary.

[0160] The control circuit C1 is connected to the sensor 80 or to each sensor 80 and is configured to control the solenoid valve 44 as a function of the signal emitted by the or each sensor 80 so as to control the distribution and the flow rate of fluid delivered to the motor 26 by the solenoid valve 44 as a function of the rotation speed of the output shaft 38.

[0161] The control circuit C1 may be integrated into a FADEC housing. It may for example be an electronic card integrated into the FADEC. Alternatively, software is provided for this purpose in the FADEC and the control circuit of the FEDEC is considered as forming the control circuit CL

[0162] Alternatively, the control circuit C1 may be integrated into an independent electronic box, such as a dedicated analog or digital computer or any other computer available in the aircraft.

[0163] The control circuit Cl or the housing comprising it may have an analog or digital operation.

[0164] In the example shown, the port 28b of the solenoid valve 28 is connected directly to the port 44a of the solenoid valve 44, that is to say without pressure balance 46.

[0165] The port 28b of the solenoid valve 28 can also be connected to the braking system 42.

[0166] The ports 44b, 44c of the solenoid valve 44 are respectively connected to the ports 28a, 28b of the motor by two conduits 48, 50.

[0167] A bypass valve 54 may be connected to these lines 48, 50 and is capable of adopting a first position in which the lines 48, 50 are isolated from each other, and a second position in which the lines are connected together. In normal operation and by default, the valve 54 is in the first position. The valve 54 is put in the second position to isolate the motor 26 during a maintenance operation for example.

[0168] The pipes 50, 52 are not connected to each other by a pressure selector 56 and do not include a pressure balancing valve 57.

[0169] Advantageously, the speed of the output shaft 38 is controlled regardless of the downstream loads (resistive or assistive).

[0170] When the loads seen by the motor 26 are resistive, the motor works as a motor to generate an actuating force. When the loads seen by the motor 26 are assistive, the motor 26 can be driven by the actuating system of the inverter 12 (and operate as a pump) and at this time its speed must be able to be controlled.

[0171] Preferably, this must be combined with precise speeds to be controlled depending on the transit phases (for example low speed at the end of opening).

[0172] In the opening phase, when the loads are resistive, the servo valve is controlled in the opening direction to control a flow rate which causes the motor 26 to rotate at a defined speed: part of this flow rate compensates for the internal leaks in the circuit 36, the other drives the motor in rotation.

[0173] When the loads are assisting, the motor 26 is driven by the inverter 12, and must therefore be braked. This braking is done at the servo valve. However, even if the servo valve closes the circuit, the motor 26 under the effect of the assisting loads continues to rotate at an uncontrolled speed due to its internal leaks. Also, the servo valve can be controlled in the closing direction to counteract the leaks in the circuit for low speeds then in the opening direction for higher speeds, the load being retained by the passage section in the servo valve. This allows, in the extreme, to control a zero speed of the inverter 12 despite the application of assisting loads. The control of the servo valve is adjusted to follow the desired opening speed in a closed loop.

[0174] In the closing phase, when the loads are resistive, the servo valve is controlled in the closing direction to control a flow rate which causes the motor 26 to rotate at a defined speed and which compensates for the internal leaks of the circuit 36.

[0175] Within the framework of the closed loop, the position of the valve is entirely entrusted to the regulation implemented. For example, in order to ensure opening of the hood, the solenoid valve 44 can freely transit between the three extreme positions defined above. Thus, the solenoid valve 44 is authorized to find itself in a position supplying the hydraulic motor in the direction of closing the hood when this is deemed necessary by the regulation in order to ensure braking of the hood.

[0176] [Fig.5] illustrates an alternative embodiment of a hydraulic control device 10 and in particular of its hydraulic circuit 36.

[0177] The solenoid valve 44 of this circuit 36 ​​is a servovalve.

[0178] The circuit 36 ​​of [Fig.5] is similar to that of [Fig.4] and differs essentially in that a filter 78 is located between the pressure source 24 and the inlet 28a of the solenoid valve 28. Furthermore, the balancing valve 57 is here located on the pipe 50 and not the pipe 52.

[0179] The valve 57 is thus arranged at the inlet of the motor 26 to retain the load on this motor in the event of stopping, without requiring the braking system.

[0180] [Fig.6] illustrates an alternative embodiment of a hydraulic control device 10 and in particular of its hydraulic circuit 36.

[0181] The solenoid valve 44 of this circuit 36 ​​is a servovalve as described in what precedes.

[0182] The circuit 36 ​​of [Fig.6] is similar to that of [Fig.4] and differs essentially in that it does not include a by-pass valve 54.

[0183] [Fig.7] illustrates an alternative embodiment of a hydraulic control device 10 and in particular of its hydraulic circuit 36.

[0184] The solenoid valve 44 of this circuit 36 ​​is a servo valve as described in what precedes.

[0185] The circuit 36 ​​of [Fig.7] is similar to that of [Fig.6] and differs essentially in that the motor 26 is of the variable displacement type. The motor 26 is thus associated with a system 58 for controlling its displacement which comprises a solenoid valve 60, called the displacement solenoid valve.

[0186] This solenoid valve 60 comprises three ports 60a-60c.

[0187] The first port 60a is connected to the port 28b of the solenoid valve 28.

[0188] The second port 60b is connected to the engine 26 for the purpose of modifying its displacement.

[0189] The third port 60c is connected to the evacuation line 34.

[0190] The solenoid valve 60 is capable of adopting a first position in which the ports 60a, 60b are connected together, and a second position in which the ports 60b, 60c are connected together.

[0191] The displacement of the engine 26 is modified when the solenoid valve 60 is in its first position. When the solenoid valve 60 is in the second position, the displacement of the engine 26 remains fixed.

[0192] The displacement solenoid valve 60 is preferably controlled by the control circuit CL. This control of the solenoid valve 60 comes from the position of the inverter, making it possible to simply adapt the displacement of the engine 26 according to a pre-defined stroke profile.

[0193] The operation of the variable displacement is described in the above.

[0194] The port 60a of the solenoid valve 60 can be connected by a pressure reducing device with nozzle 61 to an additional port 26c of the motor 26.

[0195] The engine 26 may further comprise a leak vent port 26d which is connected by a drainage line 62 to the vent line 34.

[0196] This drainage line 62 may include a filter 64 and a pressure relief valve 66.

[0197] Check valves 68, 70 may be mounted between the pipes 50, 52 and the drainage line 62. A first check valve 68 is mounted between the pipe 50 and the line 62 and only allows the passage of fluid from the line 62 to the pipe 50. A second check valve 70 is mounted between line 52 and line 62 and only allows the passage of fluid from line 62 to line 52.

[0198] Pressure relief valves 72, 74 may be mounted between the lines 50, 52 and the drainage line 62. A first pressure relief valve 72 is mounted between the line 50 and the line 62, and a second pressure relief valve 74 is mounted between the line 52 and the line 62.

[0199] The pressure relief valves 72, 74 operate as described above.

[0200] The characteristics relating in particular to the drainage line 62 and to the pressure relief valves 72, 74 allow the recirculation of leaks in the circuit so as to redistribute flow, volume, pressure to the elements of the circuit which need it during operation (nominal and degraded).

[0201] The discharge line 34 may comprise a non-return valve 32 and / or an accumulator 76.

[0202] [Fig.8] illustrates an alternative embodiment of a hydraulic control device 10 and in particular of its hydraulic circuit 36.

[0203] The solenoid valve 44 of this circuit 36 ​​is a servo valve as described above.

[0204] The circuit 36 ​​of [Fig.8] is similar to that of [Fig.3] and differs essentially in that it does not include a by-pass valve 54.

Claims

Claims

1. Hydraulic control device (10) for a thrust reverser of an aircraft propulsion unit nacelle, this device (10) comprising: - a hydraulic motor (26) capable of operating as a motor and generator, this motor (26) comprising an output shaft (38) capable of driving a mobile element of a thrust reverser (12), this motor (26) further comprising a first fluid port (26a) and a second fluid port (26b), - a first solenoid valve (28), called an isolation solenoid valve, comprising a fluid inlet (28a) capable of being connected to a fluid source (24) of an aircraft, the isolation solenoid valve (28) further comprising a first fluid port (28b) and a second fluid port (28c), the solenoid valve (28) being able to adopt a first position in which its first port (28b) is connected to its second port (28c), and a second position in which its inlet (28a) is connected to the first port (28b), - a fluid discharge line (34) which is equipped with a non-return valve (32) and which is connected to the second port (28c) of the solenoid valve (28), and - a hydraulic circuit (36) for connecting the motor (26) to the isolation solenoid valve (28) and to the discharge line (34), and more particularly the ports (26a, 26b) of the hydraulic motor (26) to the first port (28b) of the isolation solenoid valve (28) and to the discharge line (34), this hydraulic circuit (36) comprising a second solenoid valve (44) comprising four ports (44a-44d) connected respectively to the first port (28a) of the isolation solenoid valve (28), to the first and second ports (26a, 26b) of the motor (26), and to the discharge line (34), the second solenoid valve (44) being capable of adopting at least three distinct positions: - a first position in which its first port (44a) is isolated, and its second, third and fourth ports (44b-44d) are connected together, - a second position in which its first and second ports (44a, 44b) are connected together, and its third and fourth ports (44c, 44d) are connected together, and - a third position in which its first and third ports (44a, 44c) are connected together, and its second and fourth ports (44b, 44d) are connected together, characterized in that the device (10) further comprises a circuit (Cl) for controlling the second solenoid valve (44), called proportional solenoid valve, this control circuit (Cl) being connected to sensors (20) of the position of the mobile element of the thrust reverser (12) and being configured to control the second solenoid valve (44) so as to control the distribution and the flow rate of fluid delivered to the engine (26) as a function of the position of the mobile element of the thrust reverser (12).

2. Device (10) according to claim 1, wherein the first port (28b) of the isolation solenoid valve (28) is connected to the first port (44a) of the proportional solenoid valve (44) by a pressure balance (46) which has the function of providing a constant fluid flow rate to the proportional solenoid valve (44) regardless of the fluid pressure delivered by the isolation solenoid valve (28).

3. Device (10) according to claim 1 or 2, wherein the second and third ports (44b, 44c) of the proportional solenoid valve (44) are respectively connected to the first and second ports (26a, 26b) of the motor (26) by two conduits (50, 52), a bypass valve (54) being connected to the conduits (50, 52) and being able to adopt a first position in which the conduits (50, 52) are isolated from each other, and a second position in which the conduits (50, 52) are connected together.

4. Device (10) according to one of the preceding claims, in which it further comprises a hydraulic system (42) for braking the output shaft (38) of the motor (26) or of a reducer (40) connected to this output shaft (38), this braking system (42) being connected to the first port (28b) of the isolation solenoid valve (28).

5. Device (10) according to one of the preceding claims, in which the motor (26) is of the variable displacement type and is associated with a system (58) for controlling its displacement which comprises a third solenoid valve (60), called the displacement solenoid valve, which comprises three ports (60a-60c) connected respectively to the first port (28b) of the isolation solenoid valve (28), to the motor (26), and to the evacuation line (34), the displacement solenoid valve (60) being able to adopt a first position in which the first and second ports (60a, 60b) are connected together so as to impose a displacement on the motor, and a second position in which the second and third ports (60b, 60c) are connected together so as to impose another displacement on the motor.

6. Device (10) according to claim 5, in which the first port (60a) of the displacement solenoid valve (60) is connected by a pressure reducer and nozzle system (61) to an additional port (26c) of the engine (26), this system (61) being capable of supplying the engine for the purpose of lubricating its internal components and purging it.

7. Device (10) according to claim 5 or 6, wherein the displacement solenoid valve (60) is controlled by said control circuit (Cl).

8. Device (10) according to one of the preceding claims, wherein the motor (26) further comprises a leak discharge port (26d) which is connected by a drainage line (62) to the discharge line (34), said drainage line (62) comprising for example a filter (64) and a pressure relief valve (66).

9. Device (10) according to claim 8, in which a first non-return valve (68) is mounted between one of the pipes (50) and the drainage line (62), and a second non-return valve (70) is mounted between the other of the pipes (52) and the drainage line (62), each of these valves (68, 70) allowing the passage of fluid from the drainage line (62) to the corresponding pipe (50, 52), and not the reverse.

10. Method for hydraulically controlling a thrust reverser of an aircraft propulsion unit nacelle, by means of a device according to one of the preceding claims, the method comprising a step of controlling the proportionality solenoid valve as a function of signals emitted by the position sensors (20) of the movable element of the thrust reverser (12).

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