1. Technical Field of the Invention

The invention relates to a regulating device of a propeller of a turboprop. The invention particularly relates to a control device of a propeller with variable pitch blades, that is to say, a propeller whose blades can be rotated about their axis.

2. BACKGROUND

A turboprop engine is a means of propulsion, in particular used on some aircraft, and comprising a gas turbine and a propeller. The propellers of most turboprops today are including propellers variable pitch blades. There is also talk of pitch propellers. A propeller blade pitch (or not) variable is equipped with a mechanism for adjusting the pitch angle of the blades, that is to say the angle between the reference string of a blade and its plane of rotation. The setting of the blade pitch angle can adjust the characteristics of the propeller in order to optimize the performance turboprop in a wide range of flight. For example, for takeoff and climb of the aircraft, are generally designed an important step to maintain a reasonable propeller speed under high power. In cruise flight phases, it is generally aimed lower not to maintain a reasonable propeller speed with lower engine power during landing, it is generally not a negative aims to slow the aircraft and reduce the braking distance. It is therefore necessary to have a control device for changing during the flight the pitch of the blades of a propeller.

Typically, the propellers with variable pitch blades are controlled in two modes of operation depending on the flight phase of the aircraft. At low engine speeds, it directly controls the pitch of the helix. This mode is referred to throughout the text as the "beta mode". For larger engine speeds, it regulates the fan speed on the optimal operating point. This mode is referred to throughout the text as the "fashion

speed. "

It is therefore necessary to have both a control system for the beta mode which enslaves not to a set of steps, and a control system for speed mode which controls the fan speed to speed setpoint. These instructions pitch and speed are either fixed or externally provided by means of mechanical cables or electrical signals.

Currently, there are three main control system of a propeller families: electrical control, electro-hydraulic servo valve and control by hydromechanical regulation.

The electric servo valve and regulations are in practice not be used for all applications, or because the total weight of the system (as is the case of regulation by servo valve), the generated costs (this is especially the if the electric control or regulation by servo valve) or an insufficient level of maturity (which is the case of electrical control).

The principle of the hydromechanical control is to apply an oil pressure on a piston integral with a mechanism driving the blades to rotate about their axis. The piston is for example housed in a cylinder in the propeller hub, and defines one or two pressure chambers. One speaks of impeller double action when the pressure can be exerted on each side of the piston. There is talk of simple action propeller when the pressure can be exerted on one side of the piston. In this case, the return of the piston is effected by means of a spring and rollers arranged on the foot of each blade.

A device for regulating a variable propeller pitch blades comprises in known manner a first hydromechanical servo equipment of the pitch of the propeller blades to a desired pitch, and a second servo equipment hydromechanical speed rotation of the propeller at a speed setpoint.

The first hydromechanical equipment not generally servo puts out a drawer actuated by the propeller on the one hand (which provides a copy of the blade angle) and a mechanical linkage actuated by the driver for provide not set.

The second control of the speed hydromechanical equipment implements a speed control based on rotating weights.

Thus, speed mode, the rotating system flyweight, rotated by the motor from the gear at a speed proportional to that of the helix, which causes a drawer driver directly or via a hydraulic booster, the piston of the propeller and so its not. The calibration of the weights return spring defining the set speed. The speed setpoint can be modified, for example by adjusting the calibration of the spring via a mechanical cable or électroclapet all-or-nothing. Beta mode, hydraulic drawers mechanically related to not set and copying not possible to enslave not referred to the setpoint. Not set is mechanically transmitted to the slide by mechanical linkages controlled from the cockpit.

This solution has two drawbacks. On the one hand, the control action the speed setpoint of the restoring spring is either binary (two selectable speeds) is achieved by a mechanical linkage not permitting the steering by an electronic device such as an engine control computer. On the other hand, the steering set is not achieved by a mechanical linkage connected with cockpit controls, and does not allow direct control of the pitch via an electronic control computer.

The inventors have therefore sought to improve the control principle of a hydromechanical propeller variable pitch blades.

3. Objectives of the invention

The invention aims to alleviate at least some of the drawbacks of control devices of a propeller with variable pitch blades known.

In particular, the invention also aims to provide, in at least one embodiment of the invention, a control device of a propeller with variable pitch blades which no longer requires mechanical linkage connected to the cockpit to steer the propeller in beta mode.

The invention also aims to provide, in at least one embodiment of the invention, a device which allows an electric interfacing with an electronic control computer.

The invention also aims to provide, in at least one embodiment of the invention, a device that has a mass and a lower cost to the regulation devices of the prior art.

4. Summary of the Invention

To do this, the invention relates to a regulating device of a propeller with variable-pitch blades of an aircraft engine - for example a turboprop or open rotor - comprising a first servo hydromechanical equipment of the pitch of the blades of the helix at a set pitch and a second hydromechanical equipment control of the speed of rotation of the propeller at a speed setpoint.

The regulation of a propeller device according to the invention is characterized in that it further comprises a single electromechanical actuator comprising a body of mobile actuator mechanically connected to both said first hydromechanical equipment servo step to driving the set of steps and said second hydromechanical equipment servo speed so as to control the speed setpoint.

A regulating device according to the invention therefore comprises a single electromechanical actuator which is used to control both the speed setpoint and the setpoint step. This control is done by means of an organ of mobile actuator that is mechanically connected to both the first and second hydromechanical equipment hydromechanical equipment. Using a single actuator is possible because the inventors have realized that speed modes and beta are not used in the same phases of flight. It is therefore possible with a single electromechanical actuator to control either the speed reference in the corresponding phases of flight, or the set not in the corresponding phases of flight. An electromechanical actuator is further configured to receive electrical controls and actuating a member of movable actuating accordingly. Thus, a control device according to the invention allows to use a single electrical control for controlling the pitch point and the speed setpoint. In other words, a device according to the invention eliminates the need for mechanical cables in the cockpit for the beta and speed mode are directly controlled by an electrical command supplied to the electromechanical actuator. It is also possible with the invention to have only a single interface for controlling the two modes of operation of the propeller.

Advantageously and according to the invention, the movable actuating member of said electromechanical actuator is configured to be movable in at least a first range of positions in which it actuates said first hydromechanical equipment in order to determine a desired step, and in the least a second range of positions in which it actuates said second hydromechanical equipment in order to determine a speed reference.

According to a first variant of the invention, these two position ranges are distinct from each other so that in the first range of positions, the movable actuating member determines the pitch setpoint and maintains constant the set of speed ; in the second range of positions, the movable actuating member determines the speed setpoint and maintains constant the set of steps.

In other words, according to this embodiment, the movable actuating member is configured to maintain a constant speed instruction on said second device when in said first range of positions, and in order to maintain a target not constant on said first device when in said second position range.

According to another variant, the two ranges of positions are nested so that the movable actuating member acts, regardless of its position, both on the speed setpoint and the set of steps.

Advantageously and according to the invention, the movable actuating member is configured to be movable in at least a third range of positions, said neutral range, wherein it has no significant effect on any of the two hydraulic equipment.

According to this variant, the movable actuating member can be moved

in a neutral range in which it has no significant impact on the speed setpoints and not.

Advantageously and according to the invention, the hydromechanical device comprises a second hydraulic valve configured to hydraulically control the helical pitch connected to the weights configured to be driven mechanically at a speed proportional to that of the helix, and a spring recall said flyweights, and the movable member of the actuating electromechanical actuator is configured to act on a constraint of the weights return spring. This action on the constraint of the weights return spring makes it possible to modulate the speed setpoint.

Advantageously and according to the invention, the first hydromechanical device comprises at least one hydraulic slide valve configured to hydraulically control the helical pitch and driven mechanically by a linkage connected to a copying of the pitch of the helix, and said actuator moving said electromechanical actuator is configured to act on the said hydraulic slide valve in order to modulate the desired pitch of the helix.

Advantageously and according to the invention, the movable actuating member mechanically connected to said first and second hydromechanical equipment comprises at least one cam having a profile which determines an actuating law of the first and second hydromechanical equipment according to an angular position of each cam.

Advantageously and according to the invention, said electromechanical actuator is selected from the group consisting of a step-by-step motor, a DC motor or a torque motor, single path or redundant.

The invention also relates to a motor turboprop aircraft or open rotor or, more generally equipped with variable-pitch blades, equipped with a regulating device according to the invention.

The invention also relates to a regulating device and an aircraft engine equipped with such a control device, characterized in combination by all or some of the features mentioned above or below.

5. List of Figures

Other objects, features and advantages of the invention will appear on reading the following description given by way of non-limiting and which refers to the appended figures in which:

- Figure 1 is a schematic view of the operating principle of a regulating device according to the invention,

- Figure 2 is a schematic view of a control device according to an embodiment of the invention implementing a linear electromechanical actuator,

- Figure 3 is a schematic view of the curves of variation of the instructions based on the moving position of the actuating member of a control device according to an embodiment of the invention,

- Figures 4a, 4b, 4c are schematic views of a control device according to another embodiment of the invention implementing a rotary electromechanical actuator, according to different operating modes,

- Figure 5 is a schematic view of a control device according to another embodiment implementing a rotary electromechanical actuator comprising two separate cams.

6. Description of an embodiment of the invention In the figures, scales and proportions are not strictly complied with, for purposes of illustration and clarity. Throughout the following detailed description with reference to figures, identical elements, similar or analogous are designated by the same references.

According to the invention, a regulation of a propeller with variable pitch bladed device of a turboprop comprises a first servo hydromechanical equipment of the pitch of propeller blades, hereinafter referred to by the terms of first equipment and referenced 10 in FIGS. The regulating device also comprises a second hydromechanical equipment control of the speed of rotation of the helix, designated hereinafter by the terms of the second equipment and referenced 20 in the figures.

The first and second devices are not described in detail since the invention resides essentially in the control means of the equipment and not in the equipment as such which are also known to the skilled person. Moreover, these first and second devices can implement common means such as drawers, pistons, weights, etc., even if they are represented as two separate facilities in the figures for purposes of illustration and clarity.

The first device 10 and second device 20 are configured to be able to act on hydromechanically propeller pitch, and acting indirectly on the speed of the propeller.

A device according to the invention further comprises an electromechanical actuator 30 comprising a member 31 of movable actuator mechanically connected to both the first device 10 and second device 20.

According to the embodiment shown in Figures 1 and 2, actuator 30 is a linear actuator.

According to the embodiment of Figure 1, the member 31 for moving actuating rod is mobile. The movable rod can be moved to actuate either the first device 10, for example by means of a piston 11 housed in a cylinder 12 and forced by a spring 13, the second gear 20, for example by means of a piston 21 housed in a cylinder 22 and constrained by a spring 23. According to a particular embodiment, the piston 11 and 21, the cylinder 12 and 22 and the spring 13 and 23 may be housed in the equipment 10 and 20.

According to another embodiment as shown in FIG 2, the member 31 of movable actuator is formed of a first rod 32 actuated directly by an electrical command received by actuator and two rods 33, 34 connected respectively to the pistons 11, 21 via connecting rods 14, 24 each mounted pivotally about respective pivots 15, 25. Thus, the displacement of the movable rod 32 causes, according to the direction of movement of this rod, or the set point adjustment of not, the setting of the target speed through the connecting rods 14, 24, rods 33, 34 and pivots 15, 25. for example, if the rod 32 is moved to the left in Figure 2, link 14 pivots about the pivot 15 so that its upper end comes into mechanical contact with the end 33a of the rod 33 and thus causes the piston 11 integral with the rod 33, on the road, which allows the desired adjustment to not. However, if the rod 32 is moved to the right in Figure 2, the link 24 pivots about the pivot 25 so that its lower end comes into mechanical contact with the end 34a of the rod 34 and thus causes the piston 21 , integral with the rod 34, on the road, which allows the desired speed setting.

The configurations of Figures 1 and 2 make it possible to form a first range A of positions wherein the member 31 of movable actuator actuates the first hydromechanical equipment 10 in order to determine a pitch set point and a second range B of positions in which the member 31 of movable actuator activates the second unit 20 hydromechanical.

In Figure 1, the body 31 of actuator is in a position of the range A of positions. Indeed, it is found that the member 31 for actuating is in contact with the piston 11 and acts directly on the piston such that it acts on the control of the pitch of the helix. If the member 31 for actuating is actuated toward the piston 21, then the body will be in a position of the second range B of positions in which it actuates said second hydromechanical equipment 20 in order to determine a speed setpoint.

It is also noted that the configuration of Figure 1 enables to form a positional C range in which the member 31 of actuation acts on either of the pistons 11 or 21 so that in this neutral zone, or not nor speed is controlled.

Figure 3 is a schematic view in which the different ranges A, B and C thus defined have been shown in relation to the distance D of the body of mobile actuator 31 and the speed points V and P not associated. The speed setpoints V and P not evolve respectively between values

extreme Vmax and Vmin, and Pmax and Pmin, by the distance D of the movable actuating member.

According to another embodiment as shown in Figures 4a, 4b and 4c, the movable actuating member comprises a cam 36 having a profile which determines an actuating law of the first and second hydromechanical equipment according to a angular position of the cam 36. This cam 36 is pivotally mounted about an axis 37. the cam 36 also has a profile divided into three main areas including an area 41 in a circular arc, said constant area, an area 43 not circular, said gear sector and a non-circular area 42, said no sector. Sectors 42, 43 form the control sectors. In addition, the two pistons 11, 21 of the first and second devices are arranged to be in contact with the cam 36. Based on the angular position of the cam, each piston can be moved by one or the other of the cam sectors.

When the cam is rotated about the axis 37 to move the bow area 41 of circle in abutment against a piston of the first or second equipment, the equipment is maintained in a constant position. Indeed, as the cam 41 maintains the sector in contact with the piston, the distance between the axis 37 of the end of the profile facing the piston, remains constant. The compression of the piston facing the cam remains constant. In other words, as the piston remains in contact with this area in an arc, its position does not change. It is therefore well a constant area for control. This sector may have an angular range greater than the angle formed by the two pistons (here 90 °) so as to generate an angular range in which the displacement of the actuator has no effect on either the position instruction, or on the not set. This is the aforementioned neutral zone.

In contrast, when the cam is rotated about the axis 37 for causing a sector 42, 43 control facing and in contact with a piston, any rotation of the cam causes a displacement in translation of this piston facing. Indeed, the distance between the axis 37 of the end of the profile facing a piston changes since the profile is no longer circular.

In Figure 4a, the cam 36 is oriented such that each piston is in contact with the sector 41. This is the neutral zone of the actuator, which is neither the speed nor the no the propeller.

In Figure 4b, the cam 36 is oriented such that the sector gear 43 is in contact with the piston 21 of the second gear 20. Thus, throughout this range of positions, the cam 36 determines a speed setpoint. When the sector 43 is facing the piston 21 of the equipment 20, the constant area 41 is opposite the piston 11 of the equipment 10 so that no reference is not affected by the rotation of the cam throughout the sector.

In Figure 4c, the cam 36 is oriented such that the sector gear 42 is in contact with the piston 11 of the first gear 10. Thus, throughout this range of positions, the cam 36 determines a step setpoint. When the sector 42 is facing the piston 11 of the equipment 10, the constant area 41 is opposite the piston 21 of the equipment 20 such that the speed reference is not affected by the rotation of the cam throughout the sector.

According to an advantageous variant of this embodiment, the electromechanical actuator causes two distinct cams, each cam being configured to act on a reference only.

For example, and as shown in Figure 5, the actuator includes a first cam 36a configured to be able to act on a set of steps, and a second cam 36b configured to be able to act on a speed setpoint. In Figure 5, the cams are represented aside for purposes of illustration and clarity. Each cam comprises a profile which determine the control law of the set that it can operate.

The invention is not limited to the embodiments described. In particular, according to the embodiment of Figures 4a, 4b and 4c, the sectors 42 and 43 have identical profiles. However, according to other embodiments, each gear sector and may not present a clean profile to determine a specific control law. Thus, it is possible to adapt the control laws, according to the specific needs related to the type of propeller when the control device is intended.

CLAIMS

1. A device for regulating a variable pitch propeller blades of an aircraft engine comprising a first device (10) hydromechanical servo of the pitch of the propeller blades to a step setpoint and a second equipment ( 20) hydromechanical servo of the speed of rotation of the propeller at a speed setpoint,

characterized in that it comprises an actuator (30) comprising a single electromechanical actuator (31, 36) movable mechanically connected to both said first equipment (10) hydromechanical pitch servo to control the setpoint not, and said second unit (20) hydromechanical servo speed, to control the speed setpoint.

2. Device according to claim 1 characterized in that said actuator (31, 36) moving said electromechanical actuator is configured to be movable in at least a first range of positions in which it actuates said first equipment (10) hydromechanical in order to determine a desired step, and in at least a second range of positions in which it actuates said second equipment (20) hydromechanical order to determine a speed setpoint.

3. Device according to claim 2, characterized in that said actuator (31, 36) mobile is configured to maintain a constant speed instruction on said second device (20) when in said first range of positions and in order to maintain a constant step setpoint on said first device (10) when in said second position range.

4. Device according to one of claims 2 or 3, characterized in that said actuator (31, 36) mobile is configured to be movable in at least a third range of positions, said neutral range, wherein it has no significant effect on either of the hydromechanical equipment.

5. Device according to one of claims 1 to 4, characterized in that said second equipment (20) comprises a hydraulic slide hydromechanical configured to hydraulically control the helical pitch, and connected to the weights configured to be driven mechanically at a speed proportional to that of the helix, and a return spring of said flyweights, and in that said actuator (31, 36) moving said electromechanical actuator is configured to act on a constraint of said return spring of the flyweights .

6. Device according to one of claims 1 to 5, characterized in that said first device (10) hydromechanical comprises at least one hydraulic slide valve hydraulically controlling the propeller pitch, driven mechanically by a linkage connected to a copying step of the propeller, and in that said actuating member (31, 36) moving said electromechanical actuator is configured to act on the said hydraulic slide valve.

7. Device according to one of claims 1 to 6, characterized in that said movable actuating member mechanically connected to said first and second hydromechanical equipment comprises at least one cam (36) having a profile which determines an actuating law first and second hydromechanical equipment according to an angular position of each cam (36).

8. Device according to one of claims 1 to 7, characterized in that said actuator (30) is electromechanically selected from the group consisting of a step-by-step motor, a DC motor or a torque motor, single track or redundant.

9. Engine turboprop aircraft or open rotor or, more generally equipped with variable-pitch blades, equipped with a device according to claims 1 to 8.