Double-connecting-rod tilting system for electric tilting rotorcraft and control method

Abstract

The invention discloses a double-connecting-rod tilting system for an electric tilting rotorcraft and a control method. The tilting system is composed of a tilting rotorcraft nacelle structure with wings, a tilting mechanism and a rotor system. The whole tilting mechanism is driven to move by driving the main connecting rod to move, the process that the plane of a propeller disc is changed from the horizontal state to the vertical state is achieved, the tilting mechanism based on the connecting rod structure is connected with a cross beam in a nacelle, loads are reasonably distributed, the purpose of reducing the fatigue load of a force bearing component is achieved, and the service life of the whole system is prolonged. The motor of the tilting mechanism rotates by 0-180 degrees to realize the tilting of 90-0 degree of the rotor (the helicopter mode is changed into the fixed wing mode), the motor continuously rotates by 180-360 degrees in the same direction to realize the reverse tilting of 0-90 degrees of the rotor (the fixed wing mode is changed into the helicopter mode), and the tilting mechanism self-locking of the rotor at the angles of 0 degree and 90 degrees is met. The tilting rotorcraft is of great significance to development and research of the tilting rotorcraft.

Description

Technical Field

[0001] The present invention relates to the cross-field of mechanical design and automation and tilt-rotor aircraft technology, and in particular to a double-link tilt system for an electric tilt-rotor aircraft. Background Art

[0002] Tilt-rotor aircraft have the characteristics of vertical take-off and landing and high-speed cruising, taking into account the advantages of helicopters and fixed-wing aircraft. Due to its good performance, it has become one of the main configurations of low-altitude industrial light aircraft. The tilt mechanism is the actuator for the engine nacelle to switch between aircraft mode and helicopter mode. Its good working performance is of great significance to the conversion of flight modes and the control of the transition stage. At present, the tilt mechanisms developed in the world include embedded tilt mechanisms, which embed propellers into the fuselage. The structure is unique and novel, but the embedded tilt mechanism has a great impact on the aerodynamics of the aircraft and there are relatively large safety hazards when flying forward at high speed; although the servo gear transmission tilt mechanism has a large output torque, it has certain requirements for assembly accuracy and rotor speed; the turbine screw tilt mechanism can reduce the load of the tilt arm, but the response speed is limited. Summary of the invention

[0003] In view of the shortcomings of the above-mentioned tiltrotor technology, the purpose of the present invention is to provide a double-link tilt system and control method for an electric tiltrotor. The tilt mechanism only needs to control the movement of one main link to meet the requirements of the electric tiltrotor for switching flight modes, and has a fast response speed and adjustable travel. Through design optimization, the self-locking requirements in high-speed cruise mode can be met, thereby providing a stable driving effect.

[0004] This application achieves the above effects through the following technical solutions: A double-link tilt system for an electric tiltrotor aircraft, the tilt system comprising a tiltrotor aircraft nacelle structure with wings, a tilt mechanism, and a rotor system; wherein the rotor system is fixed on a hub plane of the tilt mechanism; and the tilt mechanism is connected to the nacelle structure via two upper and lower cross beams and fixings inside the nacelle structure.

[0005] Furthermore, the nacelle structure of the tilt-rotor aircraft with wings includes a wing and a nacelle structure; wherein the wing is a straight wing for a fixed-wing aircraft, the middle section of the wing is connected to two nacelle structures, and the two nacelle structures are symmetrically distributed; the nacelle structure is an olive-shaped thin-walled structure with an open front end, two upper and lower cross beams on the front side of the interior, and a pair of fixed supports at the lower rear side.

[0006] Furthermore, the tilt mechanism is formed by connecting two identical connecting rod structures, each of which includes a main connecting rod, a lower arm, a lower arm, a fixed pull rod, an upper arm, an upper arm, a front fixing piece of a hub plane, a rear fixing piece of a hub plane, a hub plane and a plurality of bolts; One side of the main connecting rod is hinged to the fixed support at the lower rear side of the nacelle structure by bolts, and the other side is hinged to the lower boom by bolts. The main connecting rod is positioned and its motion trajectory is an arc of fixed axis rotation around the fixed support at the lower rear side of the nacelle structure. One side of the lower arm is hinged to the main connecting rod by bolts, and the other side is hinged to the fixed pull rod and the lower arm by bolts. The lower arm is positioned and its motion trajectory is an arc of fixed axis rotation around the bolt connecting the main connecting rod and the lower arm. One side of the lower arm is hinged to the lower arm by bolts, and the other side is hinged to the upper arm and the rear fixing piece of the hub plane by bolts. The lower arm is positioned and its motion trajectory is an arc of fixed-axis rotation around the bolts connecting the lower arm, the fixing rod and the lower arm. One side of the fixed tie rod is hinged to the lower cross beam on the front side of the nacelle structure through bolts, and the other side is hinged to the lower arm and the lower forearm through bolts. The fixed tie rod is positioned and its motion trajectory is an arc rotating around the fixed axis of the lower cross beam on the front side of the nacelle structure. The upper boom is hinged to the upper cross beam on the front side of the nacelle structure on one side by bolts, hinged to the upper small arm on the other side by bolts, and hinged to the lower small arm and the rear fixing piece of the hub plane in the middle by bolts. The upper boom is positioned and its motion trajectory is an arc of fixed axis rotation around the upper cross beam on the front side of the nacelle structure; One side of the upper forearm is hinged to the upper large arm by bolts, and the other side is hinged to the front fixing piece of the hub plane by bolts. The upper forearm is positioned and its motion trajectory is an arc of fixed axis rotation around the bolt connecting the upper large arm and the upper forearm; One side of the propeller hub plane front fixing piece is hinged to the upper arm by bolts, and the other side is fixed to the propeller hub plane. The propeller hub plane front fixing piece is positioned and its motion trajectory is an arc of fixed axis rotation around the bolt connecting the propeller hub plane front fixing piece and the upper arm. One side of the rear fixing piece of the hub plane is hinged with the upper arm and the lower arm by bolts, and the other side is fixed with the hub plane. The rear fixing piece of the hub plane is positioned and its motion trajectory is an arc of fixed-axis rotation around the bolts connecting the rear fixing piece of the hub plane, the lower arm and the upper arm. The hub plane is fixed to the hub plane front fixing piece and the hub plane rear fixing piece.

[0007] Furthermore, the connecting rod structure is connected to another identical connecting rod structure via bolts other than those connected to the nacelle structure.

[0008] Furthermore, the rotor system includes four blades and a fairing; wherein the fairing is installed on the outside, and the four blades are fixed on the internal hub (the present invention does not include a hub) with a circumferential angle of 90° around the center of the fairing.

[0009] Based on the above-mentioned double-link tilting system of the electric tilt-rotor aircraft, the present application provides an attitude control method, which is achieved by the movement of the main link.

[0010] Furthermore, the posture control method includes two modes: When the electric tilt-rotor aircraft switches between the vertical take-off and landing mode and the horizontal forward flight mode, the rotation of the main connecting rod drives the movement of the entire tilt mechanism. At this time, the main connecting rod begins to rotate upward around the fixed support at the lower rear side of the nacelle structure, driving the lower arm to move upward and rotate around the bolt connecting the main connecting rod and the lower arm; at this time, the bolt connecting the lower arm, the lower small arm, and the fixed rod moves upward, driving the fixed rod to rotate upward around the lower cross beam at the front side of the nacelle structure, and driving the lower arm to rotate upward. The forearm rotates downward; at this time, the bolts connecting the lower forearm, the upper arm, and the rear fixing of the hub plane move downward, driving the upper arm to rotate downward around the upper cross beam on the front side of the nacelle structure, and at the same time driving the upper forearm to move downward and rotate around the bolts connecting the upper arm and the upper forearm. This process continues until the main connecting rod rotates 180° upward, and the hub plane changes from horizontal to vertical, thereby causing the tilt-rotor aircraft to enter a horizontal forward flight state. At the same time, the main connecting rod and the lower arm remain horizontal at this time and are in a self-locking state. Thereafter, the motor rotates in the same direction to drive the main connecting rod from 180° to 360°, and the hub plane changes from vertical to horizontal in the reverse direction, thereby causing the tilt-rotor aircraft to enter a hovering state. At the same time, the main connecting rod and the lower arm remain horizontal at this time and are in a self-locking state.

[0011] Compared with the prior art, the present invention has the following advantages: 1. The present invention discloses a double-link tilting system and control method for an electric tilt-rotor aircraft, wherein the tilting mechanism realizes the tilting movement by means of a connecting rod mechanism, and can reasonably distribute the pulling force brought by the rotor to each component, thus effectively alleviating the fatigue problem of the components under complex alternating aerodynamic forces.

[0012] 2. The double-link tilt system and control method for an electric tiltrotor aircraft described in the present invention, with the help of the self-locking characteristics of the tilt mechanism, can ensure stable pulling force when the tiltrotor aircraft enters the vertical take-off and landing mode and the horizontal forward flight mode, and the tilt response speed is fast, which gives flexibility in adjusting the tilt angle.

[0013] 3. The tilt mechanism described in the present invention provides a new tilt strategy and a new idea for the tilt solutions of future small and medium-sized tilt-rotor aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the overall appearance of the tilting system (vertical take-off and landing mode); Figure 2 This is a schematic diagram of the overall appearance of the tilting system (horizontal forward flight mode); Figure 3 It is a general schematic diagram of the nacelle structure of a tilt-rotor aircraft with wings; Figure 4 It is the overall schematic diagram of the tilt mechanism and rotor system; Figure 5 This is a schematic diagram of the tilt mechanism entering the horizontal forward flight mode; Figure 6 This is a schematic diagram of the tilt mechanism fully entering the horizontal forward flight mode.

[0015] In the figure, 1. wing, 2. nacelle structure, 3. upper crossbeam on the front side inside the nacelle structure, 4. lower crossbeam on the front side inside the nacelle structure, 5. fixed support at the lower rear side of the nacelle structure, 6. main connecting rod, 7. lower big arm, 8. lower small arm, 9. fixed tie rod, 10. upper big arm, 11. upper small arm, 12. front fixing piece of the hub plane, 13. rear fixing piece of the hub plane, 14. hub plane, 15. blade, 16. fairing DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings in the examples of the present invention. Figure 1 , 2 As shown, the present application adopts a double-link tilt system and control method for an electric tilt rotor aircraft, adopts a new tilt mechanism and a control method for an electric tilt rotor aircraft, as shown in the attached Figure 4 , 5 As shown in Figures 6, the present application uses a new tilting mechanism based on a connecting rod structure to achieve a fast response speed in the tilting process, a tilting strategy with reasonable force on each component, and a self-locking function in each mode.

[0017] A double-link tilt system for an electric tiltrotor aircraft, the tilt system comprising a tiltrotor aircraft nacelle structure with wings, a tilt mechanism, and a rotor system; wherein the rotor system is fixed on a hub plane of the tilt mechanism; and the tilt mechanism is connected to the nacelle structure via two upper and lower cross beams and fixings inside the nacelle structure.

[0018] Furthermore, the nacelle structure of the semi-span tilt-rotor aircraft with wings includes a wing and a nacelle structure; wherein the wing is a straight wing for a fixed-wing aircraft, the middle section of the wing is connected to two nacelle structures, and the two nacelle structures are symmetrically distributed; the nacelle structure is an olive-shaped thin-walled structure with an open front end, two upper and lower cross beams on the front side of the interior, and a pair of fixed supports at the lower rear side.

[0019] Furthermore, the tilt mechanism is formed by connecting two identical connecting rod structures, each of which includes a main connecting rod, a lower arm, a lower arm, a fixed pull rod, an upper arm, an upper arm, a front fixing piece of a hub plane, a rear fixing piece of a hub plane, a hub plane and a plurality of bolts; One side of the main connecting rod is hinged to the fixed support at the lower rear side of the nacelle structure by bolts, and the other side is hinged to the lower boom by bolts. The main connecting rod is positioned and its motion trajectory is an arc of fixed axis rotation around the fixed support at the lower rear side of the nacelle structure. One side of the lower arm is hinged to the main connecting rod by bolts, and the other side is hinged to the fixed pull rod and the lower arm by bolts. The lower arm is positioned and its motion trajectory is an arc of fixed axis rotation around the bolt connecting the main connecting rod and the lower arm. One side of the lower arm is hinged to the lower arm by bolts, and the other side is hinged to the upper arm and the rear fixing piece of the hub plane by bolts. The lower arm is positioned and its motion trajectory is an arc of fixed-axis rotation around the bolts connecting the lower arm, the fixing rod and the lower arm. One side of the fixed tie rod is hinged to the lower cross beam on the front side of the nacelle structure through bolts, and the other side is hinged to the lower arm and the lower forearm through bolts. The fixed tie rod is positioned and its motion trajectory is an arc rotating around the fixed axis of the lower cross beam on the front side of the nacelle structure. The upper boom is hinged to the upper cross beam on the front side of the nacelle structure on one side by bolts, hinged to the upper small arm on the other side by bolts, and hinged to the lower small arm and the rear fixing piece of the hub plane in the middle by bolts. The upper boom is positioned and its motion trajectory is an arc of fixed axis rotation around the upper cross beam on the front side of the nacelle structure; One side of the upper forearm is hinged to the upper large arm by bolts, and the other side is hinged to the front fixing piece of the hub plane by bolts. The upper forearm is positioned and its motion trajectory is an arc of fixed axis rotation around the bolt connecting the upper large arm and the upper forearm; One side of the propeller hub plane front fixing piece is hinged to the upper arm by bolts, and the other side is fixed to the propeller hub plane. The propeller hub plane front fixing piece is positioned and its motion trajectory is an arc of fixed axis rotation around the bolt connecting the propeller hub plane front fixing piece and the upper arm. One side of the rear fixing piece of the hub plane is hinged with the upper arm and the lower arm by bolts, and the other side is fixed with the hub plane. The rear fixing piece of the hub plane is positioned and its motion trajectory is an arc of fixed-axis rotation around the bolts connecting the rear fixing piece of the hub plane, the lower arm and the upper arm. The hub plane is fixed to the hub plane front fixing piece and the hub plane rear fixing piece.

[0020] Furthermore, the connecting rod structure is connected to another identical connecting rod structure via bolts other than those connected to the nacelle structure.

[0021] Furthermore, the rotor system includes four blades and a fairing; wherein the fairing is installed on the outside, and the four blades are fixed on the internal hub (the present invention does not include a hub) with a circumferential angle of 90° around the center of the fairing.

[0022] Based on the above-mentioned double-link tilting system of the electric tilt-rotor aircraft, the present application provides an attitude control method, which is achieved by the movement of the main link.

[0023] Furthermore, the posture control method includes two modes: When the electric tilt-rotor aircraft switches between the vertical take-off and landing mode and the horizontal forward flight mode, the initial state is Figure 1 In the vertical take-off and landing mode shown, the linkage is arranged as follows Figure 4 The rotation of the main connecting rod 6 drives the movement of the entire tilting mechanism. At this time, the main connecting rod 6 starts to rotate upward around the fixed support 5 at the lower rear side of the nacelle structure, driving the lower arm 7 to move upward and rotate around the bolts connecting the main connecting rod 6 and the lower arm 7; at this time, the bolts connecting the lower arm 7, the lower small arm 8, and the fixed tie rod 9 move upward, driving the fixed tie rod 9 to rotate upward around the lower cross beam 4 at the front side of the nacelle structure, and driving the lower small arm 8 to rotate downward; at this time, the bolts connecting the lower small arm 8 and the lower large arm 7 move upward, driving the fixed tie rod 9 to rotate upward around the lower cross beam 4 at the front side of the nacelle structure, and driving the lower small arm 8 to rotate downward. The bolts of the arm 8, the upper arm 10, and the rear fixing piece 13 of the hub plane move downward, driving the upper arm 10 to rotate downward around the upper cross beam 3 on the front side of the nacelle structure, and at the same time driving the upper small arm 11 to move downward and rotate around the bolts connecting the upper arm 10 and the upper small arm 11. This process continues until the main connecting rod 6 rotates 180° upward. At this time, the hub plane 14 changes from horizontal to vertical, and the main connecting rod 6 and the lower arm 7 remain horizontal and are in a self-locking state, thereby finally allowing the tilt-rotor aircraft to enter the state as shown in the figure. Figure 2The horizontal forward flight state, at this time the connecting rod arrangement is as follows Figure 6 The main connecting rod 6 continues to rotate from 180° to 360°. At this time, the hub plane 14 changes from vertical to horizontal, and the main connecting rod 6 and the lower arm 7 remain horizontal and are in a self-locking state, thereby changing the tiltrotor aircraft from a forward flight state to a vertical state. Figure 1 The hover state.

Claims

1. A double-link tilting system and control method for an electric tilt-rotor aircraft, characterized in that: The tilt-rotor system includes a tilt-rotor aircraft nacelle structure with wings, a tilt-rotor mechanism, and a rotor system; wherein the rotor system is fixed on the hub plane of the tilt-rotor mechanism; and the tilt-rotor mechanism is connected to the nacelle structure through two upper and lower beams and fixings inside the nacelle structure.

2. A double-link tilting system and control method for an electric tilt-rotor aircraft according to claim 1, characterized in that: The nacelle structure of the tilt-rotor aircraft with wings comprises a wing and a nacelle structure; wherein the wing is a straight wing for a fixed-wing aircraft, the middle section of the wing is connected to two nacelle structures, and the two nacelle structures are symmetrically distributed; the nacelle structure is an olive-shaped thin-walled structure with an open front end, two upper and lower cross beams on the front side of the interior, and a pair of fixed supports at the lower rear side.

3. The double-link tilting system and control method for an electric tilt-rotor aircraft according to claim 1, characterized in that: The tilt mechanism is formed by connecting two identical connecting rod structures, each of which includes a main connecting rod, a lower arm, a lower arm, a fixed pull rod, an upper arm, an upper arm, a front fixing piece of a propeller hub plane, a rear fixing piece of a propeller hub plane, a propeller hub plane and a plurality of bolts; One side of the main connecting rod is hinged to the fixed support at the lower rear side of the nacelle structure by bolts, and the other side is hinged to the lower boom by bolts. The main connecting rod is positioned and its motion trajectory is an arc of fixed axis rotation around the fixed support at the lower rear side of the nacelle structure. One side of the lower arm is hinged to the main connecting rod by bolts, and the other side is hinged to the fixed pull rod and the lower arm by bolts. The lower arm is positioned and its motion trajectory is an arc of fixed axis rotation around the bolt connecting the main connecting rod and the lower arm. One side of the lower arm is hinged to the lower arm by bolts, and the other side is hinged to the upper arm and the rear fixing piece of the hub plane by bolts. The lower arm is positioned and its motion trajectory is an arc of fixed-axis rotation around the bolts connecting the lower arm, the fixing rod and the lower arm. One side of the fixed tie rod is hinged to the lower cross beam on the front side of the nacelle structure through bolts, and the other side is hinged to the lower arm and the lower forearm through bolts. The fixed tie rod is positioned and its motion trajectory is an arc rotating around the fixed axis of the lower cross beam on the front side of the nacelle structure. The upper boom is hinged to the upper cross beam on the front side of the nacelle structure on one side by bolts, hinged to the upper small arm on the other side by bolts, and hinged to the lower small arm and the rear fixing piece of the hub plane in the middle by bolts. The upper boom is positioned and its motion trajectory is an arc of fixed axis rotation around the upper cross beam on the front side of the nacelle structure; One side of the upper forearm is hinged to the upper large arm by bolts, and the other side is hinged to the front fixing piece of the hub plane by bolts. The upper forearm is positioned and its motion trajectory is an arc of fixed axis rotation around the bolt connecting the upper large arm and the upper forearm; One side of the propeller hub plane front fixing piece is hinged to the upper arm by bolts, and the other side is fixed to the propeller hub plane. The propeller hub plane front fixing piece is positioned and its motion trajectory is an arc of fixed axis rotation around the bolt connecting the propeller hub plane front fixing piece and the upper arm. One side of the rear fixing piece of the hub plane is hinged with the upper arm and the lower arm by bolts, and the other side is fixed with the hub plane. The rear fixing piece of the hub plane is positioned and its motion trajectory is an arc of fixed-axis rotation around the bolts connecting the rear fixing piece of the hub plane, the lower arm and the upper arm. The hub plane is fixed to the hub plane front fixing piece and the hub plane rear fixing piece.

4. The double-link tilting system and control method for an electric tilt-rotor aircraft according to claim 3, characterized in that: The connecting rod structure is connected to another identical connecting rod structure by bolts other than those connected to the nacelle structure.

5. The double-link tilting system and control method for an electric tilt-rotor aircraft according to claim 1, characterized in that: The rotor system includes four blades and a fairing; wherein the fairing is installed on the outside, and the four blades are fixed on the internal hub (the present invention does not include a hub) with a circumferential angle of 90° around the center of the fairing.

6. A control method for a double-link tilt system for an electric tilt rotor aircraft, the control method being used to control the double-link tilt system for an electric tilt rotor aircraft according to claim 1, characterized in that: The posture control method includes two modes: When the electric tilt-rotor aircraft switches between the vertical take-off and landing mode and the horizontal forward flight mode, the rotation of the main connecting rod drives the movement of the entire tilt mechanism. At this time, the main connecting rod starts to rotate upward around the fixed support at the lower rear side of the nacelle structure, driving the lower boom to move upward and rotate around the bolt connecting the main connecting rod and the lower boom; At this time, the bolts connecting the lower boom, the lower arm and the fixed tie rod move upward, driving the fixed tie rod to rotate upward around the lower cross beam on the front side of the nacelle structure, and driving the lower arm to rotate downward at the same time; At this time, the bolts connecting the lower arm, the upper arm, and the rear fixings of the hub plane move downward, driving the upper arm to rotate downward around the upper cross beam on the front side of the nacelle structure, and at the same time driving the upper arm to move downward and rotate around the bolts connecting the upper arm and the upper arm. This process continues until the main connecting rod rotates 180° upward, and the hub plane changes from horizontal to vertical, thereby causing the tilt-rotor aircraft to enter a horizontal forward flight state. At the same time, the main connecting rod and the lower arm remain horizontal at this time and are in a self-locking state. After that, the motor rotates in the same direction to drive the main connecting rod from 180° to 360°, and the hub plane changes from vertical to horizontal in the reverse direction, thereby causing the tilt-rotor aircraft to enter a hovering state. At the same time, the main connecting rod and the lower arm remain horizontal at this time and are in a self-locking state.

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