RU2282566C2 - Convertiplane - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: proposed convertiplane has fuselage 1 with cabin, wings 2 and two screws 3. Screws may change their position from vertical to horizontal. Convertiplane engines are mounted in fixed parts of elongated nacelles 4 which are mounted in center section of each wing 2. Mounted on movable part of each engine nacelles 4 are screws 3; nose horizontal fin 5 is located after screws 3. Fixed section of each engine nacelles 4 is provided with vertical tail unit 6 which is inclined inside relative to vertical longitudinal plane of fixed section of engine nacelle 4.

EFFECT: enhanced stability and reliability of flying vehicle.

3 cl, 5 dwg

Description

The invention relates to the field of engineering, and in particular to the structures of convertible aircraft of vertical take-off and landing, in particular, to tiltrotors.

Their feature is the ability to convert from one aircraft to another, namely from a helicopter to an airplane and vice versa. The utility model relates to convertible aircraft with propellers.

There are a large number of screw convertiplanes with a different arrangement of both lift and propeller screws (when the same screws are used in vertical and horizontal flight) and separately-combined screw systems (when different screws are used in vertical and horizontal flight).

A common drawback of the known constructions is the presence of sharply different flight modes, therefore, the process of transition from one to another is associated with the risk of loss of stability of the device and a breakdown in a tailspin.

Known tiltrotor containing two parallel fuselages with a common wing having a console and a central beam, as well as two engines kinematically connected with two propellers. At the same time, the beam is mounted with the possibility of rotation by 90 °, and thus, the propellers alternately work as marching and as lifting (analogue - RF patent No. 2028964, CL 64 C 27/22). A disadvantage of the known tiltrotor is the large weight due to the significant power of the engines associated with small diameter screws located between the fuselages, which is caused by their placement on the beam.

Known tiltrotor containing the fuselage, wings, at least two screws mounted with the possibility of changing the position from vertical to horizontal by means of a drive and connected by a corresponding transmission with the corresponding engine, motionlessly mounted in the nacelle (prototype - US patent No. 6276633, 64 D 27 / 00).

A disadvantage of the known solution is the complication and weighting of the control system for lifting and marching propellers (hereinafter abbreviated as PM propellers) in vertical flight modes due to the use of a monocyclic control scheme, which is the longest flight time in horizontal mode and is not a dead load. As well as reducing the resource of the screw due to an additional increase in its vibration level due to artificial aerodynamic asymmetry with a cyclical change in the angle of attack of the blades. What is necessary in vertical and transient modes to obtain control forces by displacing the thrust vector of PM screws relative to a swept disk.

The problem solved by the utility model is to increase the possibility of active control in all flight modes when using a simpler control system design, due to the most advantageous performance of the tiltrotor according to the “duck” scheme, which at the same time increases the operational safety of this aircraft.

To solve the problem in a tiltrotor containing the fuselage, wings with engine nacelles, at least two screws installed with the ability to change position from vertical to horizontal by means of a drive and connected by a corresponding transmission to the corresponding engine, which is fixedly mounted in the engine nacelle, in accordance with the invention of the engine nacelle are elongated and placed in the middle part of the wings, and on the front moving part of each nacelle behind the propeller there is a front horizontal tail, and a fixed rear part installed rear vertical tail.

The tail unit is made with an inclination inward relative to the vertical longitudinal plane of the fixed part of the nacelle.

The front horizontal tail of the engine nacelle is facing the opposite fuselage, and is located on the continuation of a straight line connecting the imaginary longitudinal axis with an imaginary point of circumference of the cross section of the body of the moving part of the nacelle.

The technical result from the use of the invention is that due to the implementation of the convertiplane according to the "duck" scheme, the engine nacelles are elongated, the screws are carried forward of the fuselage, which allows, if necessary, to have a larger diameter of the screws, and the placement on the front rotary part of each engine nacelle behind the screw - the front horizontal tail (PGO), leads to the controlled behavior of the tiltrotor during vertical and transient flight modes. At the same time, in all flight modes, the PGO is in the zone of inductive air flow from the propeller and, accordingly, in all flight modes, the same, simpler control system for tiltrotor is used by controlling the PGO.

The separation of the engine nacelles with the screws away from the fuselage, in the area of the middle part of the wings, allows you to stabilize the horizontal flight modes at critical angles of attack of the tiltrotor by additional blowing the wings with a stream (covering the entire wing) from the propellers, which moves the stall from the wings to large angles of attack of the device or completely eliminates it, up to the hang of the device in an upright position.

Comparison of the claimed technical solution with the prior art in scientific, technical and patent documentation on the priority date in the main and related sections shows that the set of essential features of the claimed solution was not known, therefore, it meets the patentability condition of “novelty”.

Analysis of the known technical solutions in the art showed that the proposed device has features that are not found in the known technical solutions, and using them in the claimed combination of features makes it possible to obtain a new technical effect, therefore, the proposed technical solution has an inventive step in comparison with the prior art .

The proposed technical solution can be manufactured industrially, efficiently, feasibly, reproducibly, therefore, meets the patentability condition "industrial applicability".

Figure 1 - tiltrotor in the vertical take-off mode as a helicopter, top view;

Figure 2 - convertiplane, the same side view;

Figure 3 - convertiplane, the same, front view;

Figure 4 - tiltrotor in horizontal take-off mode as an airplane, side view;

5 is a sequential diagram of a vertical take-off take-off in a mode like a helicopter, side view.

The tiltrotor contains the fuselage 1 (see Figure 1) with a cabin (for the pilot, for the passenger, for the load), wings 2, two screws 3. The screws have the ability to change position from vertical to horizontal by means of a servo connected via a synchronous shaft to rotary gears engine nacelles 4. The tiltrotor engines are installed in the fixed parts of the elongated engine nacelles 4. The engine nacelles 4 are installed in the middle of each wing 2. On the movable part of each of the engine nacelles 4 there are placed 3 screws, behind which the PGO is located (front horizontal plumage) 5. On the fixed part of each of the nacelles 4, tail empennage is made 6. The tail empennage 6 is made with an inclination inward relative to the vertical longitudinal plane of the fixed part of the nacelle 4. PGO 5 of the nacelle 4 is turned in the direction opposite to the fuselage, located on the extension of the straight line connecting an imaginary longitudinal axis with an imaginary circumference point of the cross section of the body of the movable part of the nacelle 4.

Tiltrotor takes off, flying and landing as follows.

- Engines start.

- To carry out vertical take-off (see Figure 5) rotate the lift-marching propellers 3 (PM propellers) to 90 ° relative to the horizontal plane, and the center of mass is slightly shifted back from the axis of rotation of the propellers (which is required by alignment for the apparatus to be controlled in vertical mode ), and the proximity of the steering planes of the front horizontal tail 5 to the specified screws leads to the fact that the aircraft is most sensitive to the angle of rotation of the steering planes. At the same time, the PGO 5 rudder control margin is sufficient to transfer the aircraft after vertical take-off to horizontal flight. In the vertical mode, pitch control is carried out using PGO 5, roll control is performed by differential changes in the total pitch of PM screws 3, heading control is controlled by the same PGO (differential deviation of its steering planes). The vertical tail 6 for directional control in vertical mode is not effective.

- The transition from the vertical mode to the horizontal flight mode occurs when the PM screws 3 rotate to their coaxial position with the fuselage 1. When the PM screws 3 rotate, the tilt plane’s overall center of gravity shifts forward (due to the forward centers of gravity of the rotary parts of the nacelles 4 moving forward turning them forward and down), which is exactly what is required by the centering condition for horizontal flight. In the transition mode, the pitch and partly course control is performed by the same PGO 5, since it is also effectively transiently blown by the flow from the screws during the transition mode, and the roll control due to the differential change in the total pitch of the PM screws and partly due to the ailerons on the main bearing planes wings 2. Vertical plumage 6 also gains efficiency in the directional control as the transition mode ends. Any flight path in transition mode is possible, both horizontal and with simultaneous climb.

- Having reached the required height, the tiltrotor enters a horizontal flight, where the pitch control is carried out by the same PGO 5, roll control due to ailerons on the main bearing planes of the wings 2, and heading control by vertical tail 6.

The use of an internal inclination on the tail vertical tail 6 (to the longitudinal axis of the vehicle) makes the aircraft stable in horizontal flight when heading, since an additional pair of forces appears, which contributes to the “correct” entry of the apparatus into a bend when it is rotated.

The location of lightly loaded (with a swept area of up to 100 kg / m ² ) PM screws 3 in the middle part of the wing ensures that the air flow from the screws is guaranteed to blow around the steering planes at the ends of the wings (ailerons), which contributes to active flight control.

- In the case of takeoff and landing on an airplane, PM screws 3 tiltrotor are installed not in the extreme position, but at a certain angle (see Fig. 2c, and Fig. 1, view A), which allows for ultra-short take-off (take-off with a run at a distance of 20 -60 m).

- The following operations are provided for the vertical landing of the tiltrotor:

the horizontal flight speed decreases and the PM screws 3 are rotated to a vertical position in compliance with the flight altitude or with a smooth decrease in the trajectory. Lifting and marching propellers 3 provide a large (k = 1.25) lifting thrust for hovering the tiltrotor over the landing site. By reducing the pitch of the blades (at constant revolutions) the PM 3 screws provide a smooth descent and landing, while the landing and pitch control is controlled by the control of the PGO 5 located under the incoming air flow from the screws. Thus, the PGO 5 convertiplane is active in all modes of its flight. Therefore, the control system on a tiltrotor according to the "duck" scheme will be more correctly called - APGO (control system with Active PGO).

In case of failure of the system of turning the screws to the vertical position or engine malfunctions, landing can be carried out in airplane mode. And if it is impossible to use the airplane landing mode, you can implement it using the rescue parachute system for the entire tiltrotor (located in the central fuselage). For example, such a parachute system in a helicopter cannot be used because of the rotor rotating above it.

The location of the front horizontal tail directly behind the propeller increases the effectiveness of steering control planes in all flight modes.

The advantage of the presented solution is that the tiltrotor is made according to the “duck” scheme. A feature of such a scheme is that the horizontal tail is located in the front part, in front of the wing (unlike a classical aircraft, where the horizontal tail is located at the tail of the aircraft). Unlike conventional schemes, the plumage of the “duck” has a positive lifting force all the time, which increases the overall aerodynamic quality of the aircraft. Thus, the bearing surfaces of a tiltrotor are not only wings, but also horizontal plumage.

It follows that, ceteris paribus, the possibility of active flight control in all modes of the proposed aircraft will be significantly higher than that of its counterparts, and this control scheme is simpler, more convenient and cheaper to operate, more reliable and safer. All this is due to the successful use of the aerodynamic scheme "duck" as a tiltrotor. Until now, the duck’s tiltrotor schemes have not considered the option of turning the APGO together with PM screws, which makes it possible to use the APGO rudders at all flight modes of the tiltrotor as a simpler and more reliable version of the control system. Until now, in the projects of the convertibles of “ducks”, the PGO was considered as a fixed element of the fuselage, the use of which occurred only in horizontal flight. And in vertical modes, additional units of the PM screw control system were used - more complex monocyclic control modules in design (i.e., helicopter-type swash plates), which are not needed during horizontal flight.

The proposed tiltrotor can be manufactured using well-known technologies and materials both in a single production and in small batches.

Claims (3)

1. A tiltrotor comprising a fuselage, wings with engine nacelles, at least two screws installed with the possibility of changing the position from vertical to horizontal by means of a drive and connected by a corresponding transmission to the corresponding engine, motionlessly installed in the engine nacelle, characterized in that the engine nacelles are elongated and installed in the middle part of the wings, and on the front moving part of each nacelle behind the propeller there is a front horizontal tail unit, and on a fixed rear part adnee vertical tail. 2. The tiltrot according to claim 1, characterized in that the tail is made with an inclination inward relative to the vertical longitudinal plane of the nacelle. 3. The tiltrot according to claim 1, characterized in that the front horizontal tail of the nacelle is facing the opposite side of the fuselage and is located on the extension of a straight line connecting the imaginary longitudinal axis with the imaginary point of the circumference of the cross section of the hull of the moving part of the nacelle.

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