RU2786894C1 - Aircraft wing - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: invention relates to the field of aviation, in particular to structures of wings of rotary-wing aircrafts. Wing (3, 3’) has caisson (20) forming first profile (28) of the wing with front edge (29), rear edge (30), upper surface (31), and lower surface (32), first element (21, 21’) pivotally fixed on caisson (20) of the wing and forming second profile (35) of the wing, containing end wall (41) and second rear edge (43), second upper surface (45), and second lower surface (47). First element (21, 21’) is made with the possibility of movement between the first position, in which first and second profiles (35, 28) of the wing are located adjacently to each other, and the second position, in which second lower surface (47) and second upper surface (45) are respectively separated from first lower surface and first upper surface (32, 31). Caisson (20) of the wing contains first spar (26a) having a curvilinear cross-section in a plane perpendicular to corresponding first axis (E). End wall (41) is curvilinear and is located so that it is adjacent to first spar (26a) along second upper surface (31) and second lower surface (32), when first movable element (21, 21’) is in the first position.

EFFECT: minimum impact on bevel of a flow, created during operation of propellers, when a convertible aircraft is in a “helicopter” configuration.

15 cl, 9 dwg

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the priority of European Patent Application No. 18248246.3, filed December 28, 2018, the full disclosure of which is incorporated herein by reference.

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The present invention relates to an aircraft wing.

In particular, the present invention relates to a wing for an aircraft capable of hovering, such as a tiltrotor or rotary wing.

BACKGROUND OF THE INVENTION

In the aviation industry, aircraft are commonly used to achieve high cruising speeds, in particular over 150 knots, and high altitudes, such as over 30,000 feet. To achieve high cruising speed and high altitude gain, aircraft use fixed wings to generate the lift needed to keep the aircraft in the air. Sufficient lift can only be achieved by accelerating the aircraft on a fairly long runway. Such runways are also necessary for aircraft to land.

In contrast, helicopters generate the necessary lift by rotating the rotor blades. Consequently, helicopters are able to take off / land without the need to develop horizontal speed and in fairly small areas. In addition, helicopters are able to hover and fly at a relatively low altitude and speed, which simplifies control and allows complex maneuvers, for example, during rescue operations in the mountains or at sea.

However, helicopters have inherent limitations with a maximum operating altitude of around 20,000 feet and a maximum operating speed that cannot exceed 150 knots.

In this regard, convertiplanes and rotorcraft are known in the art to meet the demand for aircraft that have the same maneuverability and ease of use as a helicopter, while overcoming the inherent limitations described above,

In particular, convertiplanes of known types essentially comprise:

a fuselage extending along the first longitudinal axis;

a pair of cantilever wings projecting from opposite sides of the fuselage and having respective free ends opposite the fuselage and aligned along a second transverse axis substantially perpendicular to the first longitudinal axis;

a pair of nacelles holding respective engines and fixed with respect to respective wings; and

a pair of propellers rotatable about respective third axes and operatively connected to respective motors.

In such an embodiment, for example in the BELL V-280 model aircraft, the propellers are tiltable with respect to the respective engines and nacelles and the respective wing about a respective fourth axis parallel to the second axis.

Each propeller is known to comprise a drive shaft rotatable about a respective third axis and a group of blades hinged to the drive shaft, in particular distributed circumferentially around the free end of the drive shaft which protrudes relative to the respective nacelle.

The screws are connected to each other by a connecting shaft, which guarantees the operation of both screws in the event of failure of one of the engines. In known solutions, the connecting shaft extends outside the tiltrotor and is therefore exposed to the weather.

Convertiplanes can also selectively accept:

an airplane configuration in which the propellers are arranged such that the respective third axes are substantially parallel to the first axis of the tiltrotor; or

a helicopter configuration in which the propellers are arranged such that the respective third axles are substantially vertical and transverse to the first tiltrotor axle.

Due to the possibility of tilting the propellers, convertiplanes can take off and land like a helicopter, i.e. in a direction substantially perpendicular to the first longitudinal axis of the tiltrotor without the need for a runway.

In addition, convertiplanes can also take off and land on uneven terrain and without creating noise levels that are incompatible with urban areas.

In addition, convertoplanes can hover when in helicopter configuration.

Tiltrotors can also reach and maintain a cruising speed of approximately 250-300 knots and an altitude of approximately 30,000 feet when in aircraft configuration.

This cruising speed far exceeds the approximately 150 knots that determine the maximum cruising speed of helicopters.

Likewise, the above altitude is much higher than that of helicopters and allows convertiplanes in aircraft configuration to avoid the clouds and atmospheric disturbances present at low altitudes.

In addition to components commonly found on known helicopters, such as a vertical axis main rotor, for example, rotorcraft, such as the EUROCOPTER X-3 model aircraft, comprise a pair of cantilever wings protruding from respective sides of the rotorcraft fuselage along a transverse axis substantially perpendicular to the longitudinal axis of the aircraft and the axis of rotation of the main rotor.

In particular, each of the wings supports a respective propeller which, as is known, comprises a drive shaft driven by a respective engine and a set of blades hinged to the drive shaft.

In particular, each drive shaft is rotatable about a respective axis substantially parallel to the longitudinal axis of the rotorcraft, i. e. horizontal axis.

Thus, the rotorcraft can fly in the same way as a tiltrotor, i.e. take off and land in the vertical direction due to the main rotor and move in the forward direction due to the propellers and the above wings.

During forward motion, the main rotor rotates freewheeling while the thrust is generated by the propellers.

Regardless of whether it is a tiltrotor or a rotorcraft, each wing of an aircraft contains a wing box fixedly connected to the fuselage and movable elements.

The movable elements are hinged to the main body to form the respective trailing edges of the respective wings.

Examples of moving elements are ailerons and flaps.

The ailerons are designed to control the roll of the aircraft, i.e. tilt of the aircraft around the longitudinal axis of the fuselage.

To do this, the ailerons are tilted in mutually opposite directions relative to the fuselage to increase the lift of one wing and reduce the lift of the other wing.

In contrast, both flaps tilt in the same direction to increase or decrease the total lift generated by the wings.

In order to reduce overall dimensions, it is also known to combine the aileron and flap into one movable element, known in the aviation industry as a flaperon.

Flaperons function similarly to flaps, i.e. reduce or increase the lift generated by the wings during the takeoff or landing phase of the aircraft.

Flaperons function similarly to ailerons, i.e. reduce the lift of one wing and increase the lift of the other wing, if necessary, roll the aircraft.

To increase the aerodynamic efficiency of the wings when the tiltrotor is in the aircraft configuration, it is necessary to minimize the interruption of the air flow at the boundary between the wings and the corresponding moving elements.

In other words, it is necessary to make sure that the air flow flows with a minimum of disturbance at the interface between the wings and the corresponding movable elements.

In particular, each gap between the trailing edge of the wings and the movable elements causes a significant increase in the overall drag generated by the wings of the aircraft, which adversely affects the carrying capacity and efficiency of the aircraft.

To reduce these negative effects, US 5,094,412 describes a tiltrotor equipped with flaperons. Each flaperon contains a corresponding leading edge hinged to the trailing edge of the respective wing.

For each wing, the tiltrotor also includes a sealing element disposed between the respective wing and the respective flaperon to close the gap between them when the respective flaperon is actuated.

In particular, the tiltrotor includes a connecting structure for each wing, configured to place the respective sealing element in a position to close the said slot, for predetermined angular positions of the flaperon when the flaperon is actuated.

Each wing also contains an end spar located on the side of the corresponding trailing edge and having a flat section in a plane perpendicular to the direction of the wing extension.

The above solutions leave room for improvement.

In particular, the sealing elements form additional elements that require a certain amount of space and special connection structures.

There is a need in the industry to optimize the aerodynamic characteristics of the boundary between each wing box and the corresponding movable element for different angles of inclination of the movable elements while limiting the dimensions of the wing as much as possible and simplifying manufacturing.

There is also a need in the industry for stacked movables that, in addition to being able to control the tiltrotor in airplane configuration, have minimal impact on the skew created by the propellers when the tiltrotor is in helicopter configuration.

This need is exacerbated in the embodiment described above, in which the nacelles are fixed relative to the wings and the propellers are tiltable relative to the respective nacelles.

In fact, in this solution, the surface of the nacelles exposed to the skew of the propeller flow is particularly significant, which reduces the efficiency of the propellers in the helicopter configuration and leads to the need for larger propellers with obvious dimensional problems.

There is also a need in the industry to increase the available space inside the wings for fuel and/or increase the torsional rigidity of the wings.

There is also a need in the industry to protect the connecting shaft of the screws.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an embodiment of an aircraft wing that satisfies at least one of the above needs in a simple and cost effective manner.

In accordance with the invention, this problem is solved by a wing for an aircraft according to paragraph 1 of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, two non-limiting preferred embodiments are described below, given by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is a plan view of a tiltrotor, containing a pair of wings, made in accordance with the ideas of the first embodiment of the present invention, in the configuration of "helicopter";

Figure 2 is a plan view of the tiltrotor shown in Figure 1 in airplane configuration;

Figure 3 is a front view of the tiltrotor shown in Figures 1 and 2 illustrating the left wing in helicopter configuration and the right wing in airplane configuration;

Figure 4 is a sectional view along the line IV-IV shown in Figure 1 of the wing shown in Figures 1-3 in the first working configuration;

Figure 5 is a sectional view along the line V-V shown in Figure 2 of the wing shown in Figures 1-4 in a second operating configuration;

Figure 6 is an exploded side view of the wing shown in Figures 1-5 in a second operational configuration;

Figure 7 is a perspective view of the wing shown in Figures 1-6, the details of which have been removed for clarity;

Figure 8 is a further perspective view of the wing shown in Figures 1-7 from a different viewing angle, the details of which have been removed for clarity; and

Figure 9 is a plan view of a tiltrotor comprising a pair of wings made in accordance with a further embodiment of the present invention in a helicopter configuration.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to Figures 1-8, reference numeral 1 denotes an aircraft, in particular a tiltrotor.

Convertiplane 1 essentially contains:

fuselage 2 having a longitudinal axis A;

a pair of cantilever wings 3 extending from respective mutually opposite sides of the fuselage 2 and transverse to axis A;

a pair of nacelles 4 accommodating respective engines, which are not illustrated, and fixed with respect to respective wings 3; and

a pair of screws 5, functionally connected to the respective engines.

The fuselage 2 also includes a forward section 12 and a tail section 13 opposite each other along axis A.

The free edges 9 of the respective wings 3, opposite to the fuselage 2, are aligned along the axis E, perpendicular to the axis A.

It should be noted that the expressions "front", "tail", "longitudinal", "lateral", "above", "below", etc., used in this description, refer to the normal direction of flight of the tiltrotor 1 shown in the Figures. 1-3.

In particular, each screw 5 essentially contains:

a drive shaft rotatable about axis B;

bushing 7 driven by a drive shaft; and

a group of blades 8, hinged on the sleeve 7.

The screws 5 are made with the possibility of inclination around the axis C relative to the respective wings 3 and the respective nacelles 4.

Axis C is transverse to axis A and axes B.

The C axis is also parallel to the E axis.

Tiltrotor 1 can be selectively located:

in a helicopter configuration (shown in Figure 1), in which the B-axes of the screws 5 are perpendicular to the A-axis and the C-axis; and

in an airplane configuration (shown in Figure 2) in which the axes B of the screws 5 are parallel to axis A and perpendicular to axis C.

Since the screws 5 are identical, one screw 5 will be described below.

The blades 8 continue along the respective axes and contain the respective free ends 11.

During rotation, the free tips 11 of the blades 8 of the propeller 5 describe an imaginary circle, hereinafter referred to as the propeller disc 10.

Since the wings 3 are identical, for the sake of brevity, one wing 3 of the tiltrotor 1 will be described below.

In particular, wing 3 contains:

caisson 20 of the wing; and

a pair of movable elements 21 and 22, independently hinged on the wing box 20, in particular, hinged on the wing box 20 about the axis E.

In addition, the screw 5 is located on the edge 9 of the wing 3.

In particular, the movable elements 21 and 22 are located one behind the other along the axis E in the direction from the fuselage 2 to the propeller 5.

With specific reference to the "helicopter" configuration shown in Figure 1, the movable members 21 and 22 are located under the propeller 5.

In other words, the movable elements 21 and 22 are located inside an ideal cylinder obtained by pulling the screw disk 10 parallel to the axis B.

In particular, the movable element 21 is located under the disk 10 of the screw, i.e. in the area in which the blades 8 have a maximum tangential speed, and in which the effect of the bevel of the flow created by the propeller 5 is greater.

The caisson 20 of the wing contains (Figure 7):

a group of ribs 25a and 25b lying in respective planes perpendicular to axis E and extending parallel to axis A;

a group of spars 26a, 26b and 26c extending parallel to axis E, perpendicular to ribs 25a and 25b and spaced apart along axis A; and

a skin 27 designed to give the wing box 20 the shape of the wing profile 28 of the required aerodynamic shape.

In turn, the skin 27 forms:

a leading edge 29 facing forward 12 and extending parallel to axis E;

a trailing edge 30 facing tail 13, extending parallel to axis E and opposite leading edge 29 with respect to axis A;

a first aerodynamically shaped surface, hereinafter referred to as top surface 31, extending between leading edge 29 and trailing edge 30; and

a second aerodynamically shaped surface, hereinafter referred to as the bottom surface 32, extending between the leading edge 29 and the trailing edge 30 on the side opposite the top surface 31.

Spars 26a, 26b and 26c are arranged in series from the trailing edge 30 to the leading edge 29.

Elements 21 and 22 are located on the side of the trailing edge 30 of the box 20 of the wing.

Each element 21, 22 forms a corresponding profile 35, 36 of the wing and, in turn, contains:

the corresponding end wall 41 or 42, hinged on the caisson 20 of the wing;

a corresponding trailing edge 43 or 44 opposite wall 41 or 42;

a respective aerodynamically shaped surface, hereinafter referred to as top surface 45 or 46, extending between the respective wall 41 or 42 and the respective trailing edge 43 or 44; and

a respective aerodynamically shaped surface, hereinafter referred to as bottom surface 47 or 48, extending between the respective wall 41 or 42 and the respective trailing edge 43 or 44 on the side opposite the respective top surface 45 or 46.

Element 22 is hinged on wing box 20 parallel to axis E.

When tiltrotor 1 is in airplane configuration (FIG. 2), element 22 is controlled as a flaperon.

In particular, element 22 is typically located in the neutral position shown in Figure 2, in which upper surface 46 and lower surface 48 form respective extensions of upper surface 31 and lower surface 32 of wing box 20.

In addition, the element 22 is selectively movable from a neutral position to a first raised operating position and to a second lowered operating position.

In particular, by installing one of the elements 22 in the first raised position, and the other element 22 in the second lowered working position, it is possible to create a roll moment around axis A on the aircraft 1.

In contrast, when both elements 22 are placed in their respective first raised operating positions or second lowered operating positions, the total lift generated by the wings 3 decreases or increases respectively.

Preferably, the elements 22 can be selectively placed in respective third raised operating positions between the respective neutral positions and the first raised operating positions when the tiltrotor 1 exceeds a certain cruising speed to provide air brakes.

In the illustrated case, the angle between the neutral position and the first raised operating position is 30 degrees. The angle between the neutral position and the second lowered operating position is 30 degrees. The angle between the neutral position and the third raised operating position is approximately 5 degrees.

When tiltrotor 1 is in helicopter configuration (FIG. 1), element 22 is placed in the fourth lowered position.

Preferably, the angle α of movement of the element 22 between the fourth lowered position and the neutral position is configured to change depending on the speed of the tiltrotor 1 in the "helicopter" configuration.

The maximum angle α of the above movement exceeds the angle formed by the element 22 between the second lowered working position and the neutral position, and in the illustrated case is equal to 70 degrees.

The movement of the element 22 from the neutral position to the fourth lowered position occurs due to the transition of the tiltrotor 1 from the "airplane" configuration to the "helicopter" configuration and vice versa.

Alternatively, this movement occurs when the tiltrotor 1 travel speed falls below a threshold value.

Element 21 is configured to move relative to the wing box 20 between:

the first neutral position (Figure 5), in which the profiles 35 and 28 of the wing are located adjacent to each other, and the sections of the upper surface 45 and the lower surface 47, adjacent to the trailing edge 43, form the corresponding continuation of the upper surface 31 and the lower surface 32 of the box 20 of the wing ; and

the second lowered operating position (Figure 4), in which the profiles 35 and 28 of the wing are separated from each other, and the upper surface 45 and lower surface 47, respectively, are separated from the upper surface 31 and lower surface 32 of the wing box 20.

Preferably, the spar 26a is curved in a plane perpendicular to the axis E, and the wall 41 of the element 21 lies along the entire length of the spar 26a when the element 21 is in the first neutral position.

In particular, in the first neutral position (Figure 6) the profiles 35 and 28 of the wing are located adjacent to each other, and the sections of the upper surface 45 and lower surface 47, adjacent to the trailing edge 43, form the corresponding continuation of the upper surface 31 and lower surface 32 of the caisson 20 wing.

In the second lowered working position (Figure 4), the wing profiles 35 and 28 are separated from each other, and the upper surface 45 and lower surface 47, respectively, are separated from the upper surface 31 and lower surface 32 of the wing box 20.

The upper surface 45 of the element 21 forms a continuation of the spar 26a when the element 21 is in the second lowered position.

The wing box 20 defines an opening 50 open on the side opposite the leading edge 29 and delimited by two mutually successive ribs 25b and a section 53 of a spar 26a extending between the ribs 25b (Figure 7).

The trailing edge 30 of the wing box 20 is interrupted at this hole 50.

The element 21 is at least partially placed in the hole 50 when it is in the first neutral position (Figure 5).

In particular, the wall 41 and portions of the upper surface 45 and the lower surface 47 adjacent to the wall 41 are placed in the opening 50 when the element 21 is in the first neutral position.

The wall 41 also has a curvature facing the trailing edge 43 in the direction from the top surface 45 to the bottom surface 47 in a section taken in a plane perpendicular to the axis E.

When tiltrotor 1 is in the airplane configuration (FIG. 2), element 21 is placed in the first neutral position.

In the first neutral position, the air flow along the wing box 20 and the element 21 is not interrupted, which effectively optimizes the performance of the wing 3 when the tiltrotor 1 is in aircraft configuration.

In contrast, when the tiltrotor 1 is in the helicopter configuration, the element 21 is placed in the second lowered operating position.

In the second lowered operating position, the flow bevel created by the propeller 5 runs along the spar 26a and through the opening 50. As a result, the element 21 essentially has a limited effect on the flow bevel produced by the propeller 5, which optimizes the performance of the wing 3 when the tiltrotor 1 is in the "helicopter" configuration. ".

Let us consider the “aircraft” configuration of a tiltrotor 1, the trailing edge of the wing 3 is formed by the trailing edge 30 of the wing box 20, as well as the trailing edge 44 of the element 22 between the ribs 25a and 25b and the trailing edge 43 of the element 21 between the ribs 25b.

In addition, the wing box 20 forms:

a compartment 51 defined by spars 26a and 26b and portions of the top surface 31 and bottom surface 32 between these spars 26a and 26b; and

a compartment 52 defined by spars 26b and 26c and portions of the top surface 31 and bottom surface 32 between these spars 26b and 26c.

Compartment 51 forms a portion of the fuel tank.

The compartment 52 accommodates the connecting shaft 55 which connects the screws 5 to each other.

In particular, the spar 26a has a C-section, and the spars 26b and 26c have an I-section in a plane perpendicular to the axis E.

In addition, the spar 26a has a curvature facing the trailing edge 30 in a plane perpendicular to the axis E in the direction from the upper surface 31 to the lower surface 32 of the wing box 20.

Tiltrotor 1 additionally contains:

a control unit 70 (only shown schematically in Figure 6);

a group, in the illustrated case three, of actuators (not described in detail as they are not part of the present invention) operatively connected to the control unit 70 to move the element 22 between the respective neutral and operating positions; and

a pair of actuators 75 (Figures 4-7) operatively connected to the control unit 70 to move the element 21 between the respective first neutral positions and second operating positions.

In particular, the actuators 75 are located on respective mutually opposite sides of the element 21, as shown in Figures 6 and 8.

Each actuator 75 contains:

a lever 80 hinged on the wing box 20 about an axis F formed by the lower surface 32 at a position between the spars 26a and 26b, and hinged on the wall 41 of the element 21 about the axis G; and

telescopic drive 81 of variable length under the control of the control unit 70, hinged relative to the axis H, placed on the lower surface 32 of the caisson 20 of the wing in the position between the spar 26a and the trailing edge 30, and hinged on the lever 80 around the axis I in an intermediate position between the axes F and G.

In particular, the actuator 81 includes a sleeve 93 and a piston 94 sliding relative to the sleeve 93.

In the illustrated case, the F, G, H, and I axes are parallel to each other and parallel to the E axis.

In addition, the H and F axes of each actuator 75 are located on respective brackets 77 and 76 attached to a respective rib 25b.

Each actuator 75 further comprises:

shoulder 82, mounted on the element 21 and equipped with a roller 83; and

a groove 84 having a C-section in a plane perpendicular to axis E and formed by the wing box 20 at a position between the spar 26a and the trailing edge 30.

The roller 83 slides within the groove 84 following the movement of the element 21 from the second lowered position to the first neutral position.

The wing box 20 further comprises a pair of locking elements 85 forming respective seating sockets 86 interacting with respective protrusions 87 formed on the respective arms 82 when the element 21 is in the first position.

In particular, each projection 87 extends from the roller 83 in a direction transverse to the corresponding shoulder 82.

Each actuator 75 further comprises:

a connecting rod 90 hinged on the wing box 20 about the H axis, on which the corresponding drive 81 is hinged about the J axis; and

a pair of rods 91 hinged on the corresponding connecting rod 90 around the corresponding axis I, as well as on the wing box 20 and the lever 80 around the axis F.

The J axes are parallel to the corresponding F, G, H, and I axes.

The levers 80 of the actuators 75 are connected to each other by a rod 92 (shown in Figure 8) to ensure proper movement of the element 21 in the event of failure of one of the actuators 75.

As shown in Figure 8, the actuator 81 and lever 80 of each actuator 75 lie in respective planes perpendicular to the axis E, parallel to each other and spaced apart from each other.

The articulation between the drive 81 and the lever 80 around the axis I of each actuator 75 is achieved by means of a respective pin 89 (Figure 8) extending along the respective axis I and connected to the respective drive 81 and the arm 80.

The slot 84 of each actuator 75 is located between the respective actuator 81 and the lever 80 along the respective axis E.

The slot 84 of each actuator 75 is open on the side of the respective arm 82 and is formed by the respective rib 25b.

Each groove 84 extends from a respective seat 86 formed by the top surface 31 of the wing box 20 to a free end 88 located under the bottom surface 32 of the wing box 20.

In particular, each slot 84 has a curvature facing the trailing edge 30 in a plane perpendicular to axis E in the direction from the respective seat 86 to the respective end 88.

The drive 81 of each actuator 75 is located between the respective rods 91 along the respective axis E.

When the element 21 is in the neutral position (Figure 5), the drive 81, the lever 80, the rods 91 and the axis G of each actuator 75 are in the space of the corresponding groove 84 in a plane perpendicular to the axis E.

Preferably, the extension axes of the actuator 81, lever 80, and rods 91 of each actuator 75 are substantially parallel to each other.

In contrast, when the elements 21 are in the lowered operating position (Figure 4), the G axes are located downward in a plane perpendicular to the E axis at the free ends 88 opposite the locking elements 85 of the respective slots 84.

In this state, the G axis and arms 82 are preferably located under the ends 88 in a plane perpendicular to the E axis.

The wing 3 also includes a fairing 95 (only shown schematically in Figures 4 and 5) accommodating the actuator 75 when the element 21 is in the first neutral position to limit its influence on the aerodynamic characteristics of the tiltrotor 1.

Preferably fairing 95 allows the element 21 to be lowered and the actuators 75 to be moved as the element 21 moves between the first neutral position and the second lowered operating position.

The operation of the tiltrotor 1 is described in detail below, starting from the "aircraft" configuration of the tiltrotor 1 shown in Figure 1 (Figure 2) and with reference to one wing 3.

In this state, the axis B of the screw 5 is parallel to the axis A and perpendicular to the axis C.

In the airplane configuration, element 21 is in the first neutral position and element 22 is controlled as a flaperon.

In the first neutral position, the wall 41 of the element 21 is adjacent to the spar 26a, and the front portion of the element 21 is in the hole 50.

In other words, the element 21 forms a continuation of the wing box 20. In addition, the actuator 75 is located inside the fairing 95.

Therefore, the air flow along the wing box 20 and the element 21 is not interrupted, which effectively optimizes the performance of the wing 3 when the tiltrotor 1 is in an airplane configuration.

In particular, element 22 is typically located in the neutral position shown in Figure 2 and is selectively moved to a first raised operating position or a second lowered operating position.

In particular, if it is necessary to respectively reduce or increase the lift generated by the wings 3, both elements 22 are placed in the respective first raised operating positions or second lowered operating positions. Under such conditions, the elements 22 function as flaps. In contrast, if it is necessary to generate a roll moment about axis A on the tiltrotor 1, one of the elements 22 is placed in the first raised position and the other element 22 is placed in the second lowered position. Under such conditions, the elements 22 function as conventional ailerons.

Under specific operating conditions of flight, elements 21 and 22 are selectively placed in their respective third raised operating positions, in which they form air brakes.

In the case when it is necessary to use the tiltrotor 1 in the "helicopter" configuration, the screws 5 are rotated 90 degrees in the direction of the tail section 13 of the fuselage 2 around the C axis. At the end of this rotation, the B axes are perpendicular to the A axis and the C axis (Figure 1).

In this state, the flow bevel generated by the propeller 5 hits the wing section 3 forming the elements 21 and 22. The flow bevel generates the lift required for tiltrotor 1 to take off when flying in a helicopter configuration.

In addition, the hole 50 of the wing box 20 is located under the propeller disk 10, i. e. in the area where the flow bevel created by screw 5 is more intense.

In the helicopter configuration, element 21 is in the second lowered operating position and element 22 is in the fourth lowered position.

Since the element 21 is in the lowered position (FIG. 4), the bevel of the flow created by the screw 5 passes through the hole 50 formed by the element 21. In addition, the air flow passes essentially continuously along the spar 26a and the upper surface 45 of the element 21, which effectively forms elongation.

The air flow also passes through the opening defined by the wing 3 and formed by the element 22 in the fourth lowered position.

The control unit 70 moves the element 21 between the first neutral position and the second lowered operating position by means of the actuator 75. Similarly, the control unit 70 moves the element 22 between the neutral position, the first raised operating position, the second lowered operating position, the third raised position and the fourth lowered position. by means of an actuator which is not shown and is not part of the present invention.

In particular, if the pilot or an autopilot system, which is not illustrated, initiates the transition of the tiltrotor 1 from the "airplane" configuration to the "helicopter" configuration, the control unit 70 moves the element 21 from the first neutral position (Figure 5) to the second lowered operating position (Figure 4 ), and element 22 to the fourth lowered operating position.

In particular, in the first neutral position of the element 21, the protrusion 87 of each actuator 75 is in the seat 86, and the lever 80 is located essentially parallel to the actuator 81 and the connecting rod 90.

Starting from this configuration shown in Figure 5, the control unit 70 controls the extension of the piston 94 of each actuator 81 relative to the corresponding sleeve 93. This causes the levers 80 to rotate about the axis F in the counterclockwise direction, as shown in Figure 4, and the subsequent rotation of the wall 41 and element 21 around the movable axis G in a counterclockwise direction.

This causes the rollers 83 to move in a counter-clockwise direction in the slots 84 until they reach the ends 88.

In exactly the same way, in the case where the element 21 needs to be moved from the second lowered working position to the first neutral position, starting from the state shown in Figure 4, the control unit 70 controls the sliding of the pistons 94 inside the sleeve 93 of the corresponding drive 81. This causes the levers 80 to rotate around axis F in the clockwise direction, as shown in Figure 4, and the subsequent rotation of the wall 41 and the element 21 around the movable axis G in the clockwise direction.

Therefore, the rollers 83 move in a clockwise direction in the respective slots 84 until they reach the respective locking elements 85. In this situation, the element 21 is in the first neutral position, as shown in Figure 5.

The pin 92 ensures proper movement of the levers 80 in the event of failure of one of the actuators 81.

In addition, the element 21 passes through the gap between adjacent fairings 95 when installed in the second lowered operating position.

Referring to Figure 9, the reference position 3' denotes a wing in accordance with the second embodiment of the present invention.

Wing 3' is similar to wing 3 and will only be described with respect to their differences; where possible, the same or equivalent parts of the wings 3 and 3' are designated by the same reference numerals.

In particular, the wing 3' differs from the wing 3 in that the element 21' extends to the nacelle 4 and in that the element 22' is located within the element 21' in a position close to the nacelle 4.

When considering the characteristics of the wing 3 and 3', made in accordance with the present invention, the advantages that can be achieved are obvious.

In particular, the spar 26a has a curved shape in a section perpendicular to the axis E and rests along the entire length against the wall 41 when the element 21 is in the corresponding first neutral position (FIG. 5).

Due to this, the air flow passing through the wing box 20 and the element 21, located in the first neutral position, is not actually interrupted, which optimizes the efficiency of the wing 3 and 3' when the tiltrotor 1 is in the "airplane" configuration.

In contrast to the known solutions discussed at the beginning of this description, the increase in efficiency is achieved without the use of additional sealing elements. Consequently, the overall overall dimensions of the 3 and 3' wing are smaller, and the overall design is simpler.

The improvement in the efficiency of the wing 3 and 3' is further enhanced since the element 21 is partially housed in the opening 50 formed by the wing box 20. An additional increase in the efficiency of the wing 3 and 3' occurs due to the placement of actuators 75 inside the fairing 95 when the wing 3 and 3' are in the first neutral position, which limits the drag of the wing profile 3 and 3'.

As shown in Figure 4, the top surface 45 of the element 21 forms an extension of the spar 26a when the element 21 is in the second lowered operating position and the tiltrotor 1 is in the helicopter configuration.

Thus, the flow bevel created by the screw 5 passes through the hole 50 and along the spar 26a and the top surface 45 of the element 21, which actually forms a continuation of the spar 26a. Thus, the element 21 has a very limited effect on the oblique flow created by the propeller 5, which optimizes the performance of the wing 3 even when the tiltrotor 1 is in the "helicopter" configuration.

This effect is particularly enhanced, since the element 21 is located under the disk 10 of the screw, where the bevel of the flow from the screw 5 reaches its maximum intensity.

In addition, this effect makes it possible to reduce the required diameter of the propeller 5 and increase the chord of the wing 3 in comparison with the known solutions, in which the size of the wing 3 along the axis A is limited so as not to exert an excessive influence on the flow bevel created by the propeller 5, when the tiltrotor 1 is in helicopter configuration.

It has been found that the above advantages are particularly advantageous in view of the fact that the nacelles 4 of the tiltrotor 1 are fixed relative to the wing 3 and therefore interfere with the aforementioned airflow. In other words, the negative effect of collision with the nacelles 4 is offset by the positive effect of the elements 21, which essentially do not interfere with the bevel of the flow created by the propeller 5.

The wing box 20 further defines a compartment 51 bounded by the spars 26a and 26b and portions of the top surface 31 and bottom surface 32 between these spars 26a and 26b, and forming part of the fuel tank.

Due to the curved section of the spar 26a, the compartment 51 is particularly spacious, which improves the overall operational capabilities of the tiltrotor 1.

The wing box 20 additionally defines a compartment 52 bounded by the spars 26b and 26c, as well as portions of the upper surface 31 and the lower surface 32 between these spars 26b and 26c, and containing the connecting shaft 55, which connects the screws 5 to each other.

In this way, it is possible to protect the connecting shaft 55 from atmospheric agents, with an obvious increase in the marginal safety of the tiltrotor 1.

Obviously, with regard to the wing 3 and 3' described in this document, modifications and changes can be made without deviating from the scope defined in the claims.

In particular, the wall 41 may bear against the spar 26a for a limited length, for example only on the upper surface 31 and the lower surface 32.

In addition, tiltrotor 1 be an aircraft. In this case, the aircraft will receive all the advantages of tiltrotor 1 in the "aircraft" configuration. In particular, the elements 21 will act as flaperons to control the maneuverability of the aircraft.

The tiltrotor 1 can also be a rotorcraft.

Finally, elements 21 can be selectively placed in respective third raised operating positions (not shown) when tiltrotor 1 is in aircraft configuration to provide air brakes.

Each first neutral position of the elements 21 is located between a respective second lowered operating position and a respective third raised operating position in the angular direction.

Claims (47)

1. Wing (3, 3’) for an aircraft (1), containing: wing box (20) forming a first wing profile (28) with a first leading edge (29), a first trailing edge (30) opposite said first leading edge (29), a first upper surface (31) and a first lower surface (32) , opposite to each other and continuing between the specified first leading edge and the first trailing edge (30); wherein said first leading edge (29) and first trailing edge (30) have a longitudinal extent along respective first axes (E) spaced apart from each other; the first movable element (21, 21'), hinged on the specified wing box (20) and forming the second wing profile (35), in turn, containing the end wall (41) and the second rear edge (43), opposite to each other, a second top surface (45) and a second bottom surface (47) opposite each other and extending between said end wall (41) and said second trailing edge (43); wherein the said first movable element (21, 21') is configured to move relative to the said wing box (20) between: the first position, in which the specified first and second profiles (35, 28) of the wing are located adjacent to each other, and at least part of the specified second lower surface (47) and the second upper surface (45) forms the corresponding continuations of the specified first lower surface and the first upper surface (32, 31); and a second position in which said second bottom surface (47) and second top surface (45) are respectively separated from said first bottom surface and first top surface (32, 31); characterized in that the specified wing box (20) contains the first spar (26a), having a curved section in a plane perpendicular to the corresponding first axis (E); wherein said end wall (41) is curved and located so that it is adjacent to said first spar (26a) at least along said second upper surface (31) and said second lower surface (32), when said first movable element ( 21, 21') is in said first position. 2. Wing according to claim 1, characterized in that said end wall (41) is adjacent to said first spar (26a) along its entire length. 3. Wing according to claim 1 or 2, characterized in that said second upper surface (45) of said first element (21, 21') forms a continuation of said first spar (26a) when said first element (21, 21') is in the specified second position. 4. Wing according to any one of the preceding paragraphs, characterized in that said wing box (20) contains a group of ribs (25a, 25b) extending transversely to said first spar (26a) and forming a hole (50) open on the side opposite to said first leading edge (29) and limited by a pair of serial ribs (25b) and a section (53) of said first spar (26a) between said ribs (25b) along said first axis (E); wherein said first trailing edge (30) is interrupted at said opening (50); wherein the specified hole (50) when used contains at least a portion of the specified first movable element (21, 21'), forming the specified end wall (41), when the specified first movable element (21, 21') is in the specified first position. 5. Wing according to any of the previous paragraphs, characterized in that it contains at least one actuator (75) made with the possibility of selective control to move the specified first element (21, 21') between the specified first position and the second position; while said actuator (75) contains: the first lever (80) hinged on the specified wing box (20) around the second axis (F) and hinged on the specified first movable element (21, 21') around the third axis (G); and telescopic element (81) of variable length, hinged on the specified wing box (20) around the fourth axis (H) and hinged on the specified first lever (80) around the fifth axis (I); while changing the length of the specified telescopic element (81) causes the rotation of the specified first lever (80) around the specified second axis (F) and the movement of the specified first movable element (21, 21') between the specified first and second positions. 6. Wing according to claim 5, characterized in that said third axis (G) is located on said end wall (41) of said first movable element (21, 21'). 7. Wing according to any one of paragraphs. 4-6, characterized in that it contains a guide (84) having a curvilinear shape in a plane perpendicular to the specified first axis (E), and that the specified first movable element (21, 21') contains a sliding element (83), sliding inside the specified guide (84) following the movement of the specified first movable element (21, 21') between the specified first and second positions. 8. Wing according to claim 7, characterized in that: one (20) of said sliding element (83) and said wing box (20) forms a seat (86) for the end stop; a the other (83) of the specified sliding element (83) and the specified wing box (20) forms a protrusion (87); wherein said protrusion (87) enters said seat (86) when said first movable element (21, 21') is placed in said first position. 9. Wing according to claim. 7 or 8, characterized in that the specified guide (84) continues partly inside the hole (50) and partly outside the specified caisson (20) of the wing; and/or characterized in that said guide (84) comprises an end (88) opposite said seat (86) and lying in a plane perpendicular to said first axis (E); wherein the specified actuator (75) is located completely between the specified end (88) and the specified seat (86) in the section perpendicular to the specified first axis (E), when the specified first element (21, 21') is placed in the specified first position. 10. Wing according to any one of paragraphs. 4-9, characterized in that it contains a pair of said actuators (75) having respective said first levers (80) connected by a rod (92). 11. Wing according to any one of paragraphs. 5-10, characterized in that it contains a fairing (95), protruding relative to the specified first bottom surface (32) and designed to accommodate the specified actuator (75), when the specified first element (21, 21') is placed in the specified first position . 12. Wing according to any one of the preceding claims, characterized in that said first spar (26a) has a curvature in the direction of said first trailing edge (30) from said first upper surface (31) to said first lower surface (32); wherein said wing box (20) contains a first compartment (51) bounded by said first spar (26a), located on the opposite side of said hole (50) relative to said first spar (26a) and at least partially forming a fuel tank. 13. Aircraft, characterized in that it contains: fuselage (2) continuing along the sixth axis (A); a pair of wings (3, 3') according to any of the previous paragraphs, cantilevered relative to the specified fuselage (2); and a pair of screws (5) associated with said wings (3, 3') and connected by a connecting shaft (55); wherein said caisson (20) of each said wing (3, 3') contains a second compartment (52) at least partially accommodating said connecting shaft (55). 14. Tiltrotor, characterized in that it contains: fuselage (2) continuing along the fifth axis (A); a pair of wings (3, 3') according to any of the previous paragraphs; a pair of nacelles (4) containing the corresponding engines and fixed relative to the specified wings (3, 3'); and a pair of propellers (5) connected to said wings (3, 3') driven by said respective engines, rotatable about respective seventh axes (B) and tiltable about an eighth axis (C) parallel to said first axis (E), between: a third position in which said seventh axis (B) is parallel to said sixth axis (A), which is achieved when said tiltrotor (1) is in aircraft configuration; and a fourth position in which said seventh axles (B) are perpendicular to said first axle (E) and said sixth axle (A), which is achieved when said tiltrotor (1) is in helicopter configuration; wherein said first movable element (21, 21') in use is placed in said first position when said tiltrotor (1) is in said aircraft configuration, and in use is placed in said second position when said tiltrotor (1) is in said helicopter configuration. 15. Tiltrotor according to claim 14, characterized in that each said wing (3, 3') contains a second movable element (22) located along said first axis (E) between said first movable element (21, 21') and said screw (5); wherein each specified screw (5) contains a sleeve (7) and a group of blades (8) hinged on the specified sleeve (7); while these blades (8) contain the corresponding tips (11), forming an imaginary disk (10) of the screw; wherein each said imaginary propeller disk (10) is located above said first movable element (21, 21') when said tiltrotor (1) is in said helicopter configuration.

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