A trailing edge flap system for helicopter blades based on piezoelectric materials

Abstract

The embodiment of the present invention discloses a trailing edge flap system for a helicopter blade based on piezoelectric materials, which relates to the technical field of rotorcraft and can change the deflection angle of the trailing edge flap. The present invention includes: a piezoelectric actuator is installed inside the blade, and when a driving voltage is applied to the piezoelectric actuator, the piezoelectric actuator undergoes an elongation or shortening deformation, directly or indirectly driving the trailing edge flap to deflect. When the applied voltage is removed, the piezoelectric actuator no longer deforms, and the trailing edge flap returns to a horizontal position, thereby achieving active deflection of the trailing edge flap within a certain range and improving the performance of the rotor. The blade equipped with the trailing edge flap can change the deflection angle of the trailing edge flap according to the flight conditions, thereby affecting the angle of attack and lift, and has the functions of improving the efficiency of the rotor, improving the flight conditions, and reducing the vibration and noise of the rotor.

Description

Technical Field

[0001] The invention relates to the technical field of rotorcraft, and in particular to a trailing edge flap system of a helicopter blade based on piezoelectric materials. Background Art

[0002] The application range of rotorcraft is very wide. Thanks to its vertical take-off and landing capability, as well as excellent low-altitude performance, it plays an irreplaceable role in many occasions from military to civilian use, such as military operations, disaster relief, material transportation and personnel transportation.

[0003] The main rotor plays a leading role in the rotorcraft, providing the helicopter with lift to overcome gravity, pulling force for horizontal flight, and lateral and longitudinal control torques to control the fuselage attitude. However, at the same time, the special working conditions of the rotor will also cause high vibration and noise to the helicopter. In response to this problem, a solution has been proposed to drive the active twisting of the blades through piezoelectric actuators, that is, to improve the flight conditions and flight performance by changing the twist angle of the blades.

[0004] However, how to change the deflection angle of the trailing edge flaps to further reduce the vibration and noise of the rotor has always been a design difficulty that needs to be studied and solved. Summary of the invention

[0005] An embodiment of the present invention provides a trailing edge flap system of a helicopter blade based on piezoelectric material, which can change the deflection angle of the trailing edge flap.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0007] Piezoelectric actuator A (5) and piezoelectric actuator B (6) are installed between the skin (1) and the filling material (3) of the blade; the front end of the piezoelectric actuator A (5) and the front end of the piezoelectric actuator B (6) are fixed between the skin (1) and the beam (2), and the end of the piezoelectric actuator A (5) and the end of the piezoelectric actuator B (6) are both floating; a groove is opened in the filling material (3), and the piezoelectric actuator A (5), the piezoelectric actuator B (6), the metal wire, the wire (11) and the gasket 7 (ix) are all installed in the groove, wherein the piezoelectric actuator A (5) and the piezoelectric actuator B ( 6) are connected to the trailing edge flap (4) through the metal wire; the head end of the metal wire is fixedly connected to the piezoelectric actuator A (5) and the piezoelectric actuator B (6) by glue, and the tail end of the metal wire is connected to the trailing edge flap (4) by a wire clamp; the trailing edge flap (4) is connected to the main body of the blade by two hinges (10), and the hinge (10) is installed between the front end of the trailing edge flap (4) and the blade skin (1); the two ends of the elastic skin A (8) are respectively connected to the skin (1) and the trailing edge flap (4), and the two ends of the elastic skin B (9) are also respectively connected to the skin (1) and the trailing edge flap (4).

[0008] The metal wire passes through the opening at the rear end of the skin (1); the front end of the trailing edge flap (4) and the rear end of the blade skin (1) are opened, and the hinge (10) is installed through interference fit.

[0009] The metal wire includes: metal wire A7(i) to metal wire D7(iv), and the wire clamp includes: wire clamp A7(v) to wire clamp D7(viii); the metal wire A7(i) to metal wire D7(iv) passes through the opening at the rear end of the skin (1); the head end of the metal wire A7(i) to metal wire D7(iv) is connected to the piezoelectric actuator A(5) and the piezoelectric actuator B(6), and the tail end is connected to the trailing edge flap (4) through the wire clamp A7(v) to wire clamp D7(viii).

[0010] Metal wire A7(i) and metal wire B7(ii) start from the rear end of piezoelectric actuator A(5), pass through the filling material (3) and the skin (1), and are finally connected to the trailing edge flap (4) through wire clamp A7(v) and wire clamp D7(vi) respectively; metal wire C7(iii) and metal wire D7(iv) start from the rear end of piezoelectric actuator B(6), pass through the filling material (3) and the skin (1), and are finally connected to the trailing edge flap (4) through wire clamp A7(vii) and wire clamp D7(viii) respectively. Gasket 7(ix) is placed between the filling material (3) and the metal wires.

[0011] The two ends of the hinge (10) are sharpened pins, which are respectively connected to the main body of the blade and the trailing edge flap (4) through interference fit.

[0012] The piezoelectric actuator B (6) is installed between the skin (1) and the filling material (3) of the blade. Except for the front end of the piezoelectric actuator B (6) fixedly installed at the connection between the skin (1) and the beam (2), the rest of the piezoelectric actuator B (6) is floating, so that the rear end of the piezoelectric actuator B (6) can generate telescopic displacement along the skin direction.

[0013] The rear end of the piezoelectric actuator B (6) is connected to the trailing edge flap (4) via a metal wire C7 (iii) and a metal wire D7 (iv); the trailing edge flap (4) is connected to the main body of the blade via a flexible hinge (12), wherein the flexible hinge (12) and the skin (1) are integrally formed during manufacture; and the two ends of the elastic skin B (9) are respectively connected to the skin (1) and the trailing edge flap (4) via glue.

[0014] The flexible hinge (12) is made of the same material as the skin (1), and the main body of the blade, the trailing edge flap (4) and the flexible hinge (12) are integrally formed during processing, so as to utilize the elasticity of the flexible hinge (12) to provide the trailing edge flap (4) with deflection freedom.

[0015] The trailing edge flap (4) is deflected upward or downward by the extension and retraction of the piezoelectric actuator.

[0016] The trailing edge flap system of a helicopter blade based on piezoelectric material provided by an embodiment of the present invention has a piezoelectric actuator installed inside the blade. When a driving voltage is applied to the piezoelectric actuator, the piezoelectric actuator undergoes an elongation or shortening deformation, directly or indirectly driving the trailing edge flap to deflect. When the applied voltage is removed, the piezoelectric actuator no longer deforms, and the trailing edge flap returns to a horizontal position, thereby achieving active deflection of the trailing edge flap within a certain range and improving the performance of the rotor. The blade equipped with the trailing edge flap can change the deflection angle of the trailing edge flap according to the flight conditions, thereby affecting the angle of attack and lift, and has the functions of improving the efficiency of the rotor, improving the flight conditions, and reducing the vibration and noise of the rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of the general assembly structure of a common hinged trailing edge flap system for a helicopter blade based on a first piezoelectric material provided by an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of a filling material structure with slots provided in an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of installation details of a transmission system provided in an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of the overall structure of a transmission system provided by an embodiment of the present invention;

[0022] Figure 5 A schematic diagram of a skin structure opening provided by an embodiment of the present invention;

[0023] Figure 6 A schematic diagram of a hinge structure provided by an embodiment of the present invention;

[0024] Figure 7 A schematic diagram of the wiring arrangement of a piezoelectric actuator provided in an embodiment of the present invention;

[0025] Figure 8 A schematic diagram of the installation of a flexible skin provided by an embodiment of the present invention;

[0026] Fig. 9 A schematic diagram of the flap deflection limit position provided in an embodiment of the present invention.

[0027] Fig.10 A schematic diagram of the general assembly structure of a second piezoelectric material-based helicopter blade flexible hinge trailing edge flap system provided by an embodiment of the present invention;

[0028] Fig.11 A schematic diagram of a flexible hinge connection structure provided by an embodiment of the present invention;

[0029] Fig.12 A schematic diagram of the flap deflection limit position provided by an embodiment of the present invention;

[0030] Fig.13 A schematic diagram of the overall assembly structure of a third piezoelectric material-based helicopter blade flexible hinge trailing edge flap system provided in an embodiment of the present invention;

[0031] Fig.14 A schematic diagram of the flap deflection limit position provided by an embodiment of the present invention;

[0032] Among them, the numbers in the accompanying drawings represent: skin-1, beam-2, filling material-3, trailing edge flap-4, piezoelectric actuator A-5, piezoelectric actuator B-6, transmission system-7, elastic skin A-8, elastic skin B-9, hinge-10, wire-11, flexible hinge-12, metal wire A-7(i), metal wire B-7(ii), metal wire C-7(iii), metal wire D-7(iv), wire clamp A-7(v), wire clamp B-7(vi), wire clamp C-7(vii), wire clamp D-7(viii), gasket-7(ix). DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. It can be understood by those skilled in the art that, unless specifically stated, the singular forms "one", "one", "said" and "the" used herein may also include plural forms. It should be further understood that the term "including" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used here may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as generally understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0034] It is found in the current research that if the main rotor blades are not equipped with trailing edge flaps, they cannot adapt to the needs of different aerodynamic environments, not only are they inefficient, but they also generate large vibrations and noise. In response to this problem, this embodiment provides a design idea and an improved design. Specifically, the active deflection of the trailing edge flap within a certain range is achieved directly or indirectly through the deformation of the piezoelectric actuator. The trailing edge flap has the characteristics of light weight, good driving effect, and fast response speed. Actively deflecting the trailing edge flap according to the flight conditions can improve the performance of the rotor while reducing vibration and noise. The design purpose of this embodiment is mainly to ultimately realize the design of changing the deflection angle of the trailing edge flap, and the general design idea can be implemented as at least three optional trailing edge flap systems for helicopter blades based on piezoelectric materials.

[0035] The first piezoelectric material-based helicopter blade trailing edge flap system provided by the embodiment of the present invention is as follows: Figure 1 As shown, including:

[0036] Piezoelectric actuator A (5) and piezoelectric actuator B (6) are installed between the skin (1) and the filling material (3) of the blade.

[0037] In the actual production process, a groove of suitable size can be opened in the filling material (in the finished product state after installation, the groove and the skin form a cavity), such as Figure 2 As shown, it is used to install piezoelectric actuators, transmission systems, hinges, wires and other components that need to be installed inside the blade. The specific design of the groove size and the usual method of opening the groove are common sense means that are very familiar to those skilled in the art, so they are not repeated in this embodiment. In current mainstream products, the filling material can be a filling material, such as a polystyrene filling material.

[0038] The front end of the piezoelectric actuator A (5) and the front end of the piezoelectric actuator B (6) are both fixed between the skin (1) and the beam (2), and the rear end of the piezoelectric actuator A (5) and the rear end of the piezoelectric actuator B (6) are both floating, so that the rear ends of the piezoelectric actuator A (5) and the piezoelectric actuator B (6) can generate telescopic displacement along the skin direction.

[0039] A groove is provided in the filling material (3), and the piezoelectric actuator A (5), the piezoelectric actuator B (6), the metal wire, the wire (11) and the gasket 7 (ix) are all installed in the groove, wherein the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are connected to the trailing edge flap (4) through the metal wire. The gasket 7 (ix) is placed between the filling material (3) and the metal wire to provide support and reduce wear. Specific details are as follows Figure 3 shown.

[0040] The metal wire passes through the opening at the rear end of the skin (1).

[0041] The head end of the metal wire is fixedly connected to the piezoelectric actuator A (5) and the piezoelectric actuator B (6) by glue, and the tail end of the metal wire is connected to the trailing edge flap (4) by a wire clamp. Figure 4 shown.

[0042] The trailing edge flap (4) is connected to the main body of the blade via two hinges (10). The front end of the trailing edge flap (4) and the rear end of the blade skin (1) are provided with holes for installing the hinges (10). The trailing edge flap (4) is deflected upward or downward by the extension and contraction of the piezoelectric actuator A (5) and the piezoelectric actuator B (6). The two ends of the hinge (10) are sharpened pins, which are respectively connected to the main body of the blade and the trailing edge flap (4) via interference fit. The blade skin opening structure is as follows: Figure 5 As shown, the structure of the hinge is as follows Figure 6 shown.

[0043] The connection method of the wire (11) required to drive the piezoelectric actuator is as follows Figure 7 shown.

[0044] The two ends of the elastic skin A (8) are connected to the skin (1) and the trailing edge flap (4), respectively. The two ends of the elastic skin B (9) are also connected to the skin (1) and the trailing edge flap (4), respectively. The connection points between the elastic skin A (8) and the elastic skin B (9) and the skin (1) and the trailing edge flap (4) are fixed by glue. The two ends of the elastic skin A (8) and the elastic skin B (9) are connected to the skin (1) and the trailing edge flap (4), respectively. Figure 8 As shown, the blade maintains its aerodynamic shape when the trailing edge flap (4) is deflected.

[0045] In this embodiment, the trailing edge flap is connected to the blade body through two hinges, and two floating piezoelectric actuators are symmetrically distributed in the blade and connected to the trailing edge flap through metal wires and wire clamps. When a driving voltage is applied to the piezoelectric material, the piezoelectric material deforms, and the trailing edge flap is deflected by pulling the metal wire. When the applied voltage is cancelled, the piezoelectric material returns to its original length, driving the trailing edge flap to reset. Fig. 9 The initial position of the trailing edge flap deflection and the two extreme positions of upward and downward deflection are shown.

[0046] In this embodiment, the metal wire includes: metal wire A7(i) to metal wire D7(iv), and the wire clamp includes: wire clamp A7(v) to wire clamp D7(viii); the metal wire A7(i) to metal wire D7(iv) pass through the opening at the rear end of the skin (1). The head end of the metal wire A7(i) to metal wire D7(iv) is connected to the piezoelectric actuator A(5) and the piezoelectric actuator B(6), and the tail end is connected to the trailing edge flap (4) through the wire clamp A7(v) to wire clamp D7(viii).

[0047] Among them, the corresponding relationship between the metal wire and the wire clamp can be as follows Figure 4 As shown, the tail end of the metal wire A7(i) is connected to the trailing edge flap (4) through the wire clamp A7(v), the tail end of the metal wire A7(ii) is connected to the trailing edge flap (4) through the wire clamp A7(vi), the tail end of the metal wire A7(iii) is connected to the trailing edge flap (4) through the wire clamp A7(vii), and the tail end of the metal wire A7(iv) is connected to the trailing edge flap (4) through the wire clamp A7(viii).

[0048] Specifically, the front ends of the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are fixed between the skin (1) and the beam (2), and a groove for accommodating the piezoelectric actuator A (5) and the piezoelectric actuator B (6) is opened on the filling material (3). When the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are installed in the filling material (3), the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are completely in the groove of the filling material (3) and have a movable margin. The piezoelectric actuator B (6) is installed between the skin (1) and the filling material (3) of the blade, and its front end is fixed between the skin (1) and the beam (2), and the rest of the part is floating. The rear end of the piezoelectric actuator B (6) can produce telescopic displacement along the skin direction. The rear end of the piezoelectric actuator B (6) is connected to the trailing edge flap (4) through the metal wire C7 (iii) and the metal wire D7 (iv). A groove is formed below the filling material (3) for placing the piezoelectric actuator B (6) and the metal wire C7 (iii), the metal wire D7 (iv), the electric wire (11) and the gasket 7 (ix). A hole is formed at the rear end of the skin (1) for passing the metal wire C7 (iii) and the metal wire D7 (iv). The trailing edge flap (4) is connected to the blade body through a flexible hinge (12), and the flexible hinge (12) and the skin (1) are integrally formed during the manufacturing process. The two ends of the elastic skin A (8) are connected to the skin (1) and the trailing edge flap (4) by glue.

[0049] Specifically, the metal wire A7(i) and the metal wire B7(ii) start from the rear end of the piezoelectric actuator A(5), pass through the filling material (3) and the skin (1), and are finally connected to the trailing edge flap (4) through the wire clamp A7(v) and the wire clamp D7(vi) respectively. The metal wire C7(iii) and the metal wire D7(iv) start from the rear end of the piezoelectric actuator B(6), pass through the filling material (3) and the skin (1), and are finally connected to the trailing edge flap (4) through the wire clamp A7(vii) and the wire clamp D7(viii) respectively. In the transmission system (7), the metal wire C7 (iii) and the metal wire D7 (iv) start from the rear end of the piezoelectric actuator B (6), pass through the filling material (3) and the skin (1), and are finally connected to the trailing edge flap (4) through the wire clamp C7 (vii) and the wire clamp D7 (viii). The gasket 7 (ix) is placed between the filling material (3) and the metal wire to provide support and reduce wear.

[0050] The second piezoelectric material-based helicopter blade trailing edge flap system provided in this embodiment is as follows: Fig.10 As shown, including:

[0051] The piezoelectric actuator B (6) is installed between the skin (1) and the filling material (3) of the blade, with its front end fixed between the skin (1) and the beam (2), and the remaining part floating, so that the rear end of the piezoelectric actuator B (6) can produce telescopic displacement along the skin direction.

[0052] A groove is provided in the filling material (3), and the piezoelectric actuator B (6), a metal wire, an electric wire (11) and a gasket 7 (ix) are all installed in the groove, wherein the piezoelectric actuator B (6) is connected to the trailing edge flap (4) through the metal wire. The gasket 7 (ix) is arranged between the filling material (3) and the metal wire to provide support and reduce wear.

[0053] The trailing edge flap (4) is connected to the main body of the blade via a flexible hinge (12), and the flexible hinge (12) and the skin (1) are integrally formed during production.

[0054] Among them, in the actual production process, the composite material layup process is usually used to arrange the layers reasonably and directly manufacture the integrated skin and flexible hinge, such as Fig.11 The involved layer laying process is a common sense means that is well known to those skilled in the art, and therefore will not be described in detail in this embodiment.

[0055] In this embodiment, except for the number of piezoelectric actuators, the number of metal wires, the number of elastic skins, the selection and installation of hinges, the rest are the same as the previous embodiment.

[0056] In this embodiment, the trailing edge flap (4) is deflected upward or downward by the extension and retraction of the piezoelectric actuator B (6). Fig.12 The initial position of the trailing edge flap deflection and the extreme positions of upward and downward deflection are shown.

[0057] In this embodiment, the trailing edge flap is connected to the blade body through a flexible hinge. A floating piezoelectric actuator is distributed at the bottom of the blade and connected to the trailing edge flap through a metal wire and a wire clamp. When a driving voltage is applied to the piezoelectric material, the piezoelectric material deforms, and the trailing edge flap is deflected by pulling the metal wire. At the same time, the flexible hinge stores elastic potential energy. When the applied voltage is cancelled, the piezoelectric material returns to its original length, and the elasticity of the flexible hinge resets the trailing edge flap.

[0058] The third piezoelectric material-based helicopter blade trailing edge flap system provided in this embodiment is as follows: Fig.13 As shown, including:

[0059] The trailing edge flap (4) is an extension of the blade structure and is a closed chamber structure.

[0060] Among them, in the actual production process, for composite materials, a closed-cell structure can be processed through reasonable layer setting. The layering process involved is a common sense means that technicians in this field are very familiar with, so it will not be repeated in this embodiment.

[0061] The piezoelectric actuator A (5) and the piezoelectric actuator B (6) are installed on the inner side of the skin (1) of the trailing edge flap (4), and are located between the skin (1) and the foam (3). The piezoelectric actuator A (5) and the piezoelectric actuator B (6) are tightly bonded to the skin (1) by glue, so that their deformation is transmitted to the skin (1).

[0062] In this embodiment, the skin is displaced by the extension and retraction of the piezoelectric actuator B (6), and the elasticity of the trailing edge flap (4) itself enables it to deflect upward and downward. Fig.14 The initial position of the trailing edge flap deflection and the extreme downward deflection position are shown.

[0063] In this embodiment, the trailing edge flap is an extension of the blade structure, and two piezoelectric actuators are glued to the upper and lower skins of the trailing edge flap. When a driving voltage is applied to the piezoelectric material, the piezoelectric material deforms, driving the blade to produce elastic deformation. When the applied voltage is canceled, the elasticity of the blade itself drives the trailing edge flap to reset. The present invention is applicable to the main blade of a rotorcraft.

[0064] The specific working principle of the embodiment can be understood as follows: conventional blades are not equipped with trailing edge flaps, and the airfoil is fixed, which cannot adapt to the needs of different aerodynamic environments. Not only is the efficiency low, but also large vibration and noise are generated. After the trailing edge flaps are installed, the rotor performance can be improved by the active deflection of the trailing edge flaps, while reducing vibration and noise. When the helicopter with a helicopter blade flap system of piezoelectric material flies forward, the controller sends a signal to control the deflection of the trailing edge flap according to the rotor working condition and the aerodynamic environment. When the deflection control is not performed, the piezoelectric actuator. No driving voltage is applied, no driving force is generated, and no deformation occurs. Since the trailing edge flap is not subjected to additional torque, it is in the initial position. When the controller sends a deflection signal, a voltage is applied to the piezoelectric actuator, so that the piezoelectric actuator is extended or shortened, directly or indirectly generating a torsional torque on the trailing edge flap, so that the trailing edge flap is deflected. When the driving voltage is not applied, the piezoelectric actuator restores the original length, and the trailing edge flap returns to the initial position again. The deflection process of the trailing edge flap affects the aerodynamic shape of the blade. The dynamic deflection of the trailing edge flap adapts to different aerodynamic environments, improves the efficiency of the rotor, and reduces vibration and noise. At the same time, the flap system based on piezoelectric materials is an active device that can be actively deflected as needed to adapt to different working conditions according to different purposes.

[0065] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A trailing edge flap system for helicopter blades based on piezoelectric materials, It is characterized in that include: The piezoelectric actuator A (5) and the piezoelectric actuator B (6) are installed between the skin (1) and the filling material (3) of the blade; The front end of the piezoelectric actuator A (5) and the front end of the piezoelectric actuator B (6) are both fixed between the skin (1) and the beam (2), and the end of the piezoelectric actuator A (5) and the end of the piezoelectric actuator B (6) are both floating; A groove is provided in the filling material (3), and the piezoelectric actuator A (5), the piezoelectric actuator B (6), the metal wire, the electric wire (11) and the gasket 7 (ix) are all installed in the groove, wherein the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are both connected to the trailing edge flap (4) through the metal wire; The head end of the metal wire is fixedly connected to the piezoelectric actuator A (5) and the piezoelectric actuator B (6) by glue, and the tail end of the metal wire is connected to the trailing edge flap (4) by a wire clamp; The trailing edge flap (4) is connected to the main body of the blade via two hinges (10), and a hinge (10) is installed between the front end of the trailing edge flap (4) and the blade skin (1); The two ends of the elastic skin A (8) are respectively connected to the skin (1) and the trailing edge flap (4), and the two ends of the elastic skin B (9) are also respectively connected to the skin (1) and the trailing edge flap (4); The metal wire includes: metal wire A7 (i) to metal wire D7 (iv), the wire clamp includes: wire clamp A7 (v) to wire clamp D7 (viii); Metal wires A7 (i) to D7 (iv) pass through the opening at the rear end of the skin (1); The head ends of the metal wires A7 (i) to D7 (iv) are connected to the piezoelectric actuator A (5) and the piezoelectric actuator B (6), and the tail ends are connected to the trailing edge flap (4) through the wire clamps A7 (v) to D7 (viii); The metal wire A7 (i) and the metal wire B7 (ii) start from the rear end of the piezoelectric actuator A (5), pass through the filling material (3) and the skin (1), and are finally connected to the trailing edge flap (4) through the wire clamp A7 (v) and the wire clamp D7 (vi) respectively; The metal wire C7 (iii) and the metal wire D7 (iv) start from the rear end of the piezoelectric actuator B (6), pass through the filling material (3) and the skin (1), and are finally connected to the trailing edge flap (4) through the wire clamp A7 (vii) and the wire clamp D7 (viii) respectively.

2. The trailing edge flap system of a helicopter blade according to claim 1, It is characterized in that The metal wire passes through the opening at the rear end of the skin (1); Holes are opened at the front end of the trailing edge flap (4) and the rear end of the blade skin (1), and hinges (10) are installed by interference fit.

3. The trailing edge flap system of a helicopter blade according to claim 1, It is characterized in that The spacer 7 (ix) is placed between the filling material (3) and the metal wire.

4. The trailing edge flap system of a helicopter blade according to claim 1, It is characterized in that Both ends of the hinge (10) are sharpened pins, which are respectively connected to the main body of the blade and the trailing edge flap (4) through interference fit.

5. The trailing edge flap system of a helicopter blade according to claim 1 or 3, It is characterized in that The piezoelectric actuator B (6) is installed between the skin (1) and the filling material (3) of the blade. Except for the front end of the piezoelectric actuator B (6) fixedly installed at the connection between the skin (1) and the beam (2), the rest of the piezoelectric actuator B (6) is floating, so that the rear end of the piezoelectric actuator B (6) can generate telescopic displacement along the skin direction.

6. The trailing edge flap system of a helicopter blade according to claim 5, It is characterized in that The rear end of the piezoelectric actuator B (6) is connected to the trailing edge flap (4) via a metal wire C7 (iii) and a metal wire D7 (iv); The trailing edge flap (4) is connected to the main body of the blade via a flexible hinge (12), wherein the flexible hinge (12) and the skin (1) are integrally formed during manufacture; The two ends of the elastic skin B (9) are respectively connected to the skin (1) and the trailing edge flap (4) by glue.

7. The trailing edge flap system of a helicopter blade according to claim 6, It is characterized in that The flexible hinge (12) is made of the same material as the skin (1); the main body of the blade, the trailing edge flap (4) and the flexible hinge (12) are integrally formed during processing, so as to utilize the elasticity of the flexible hinge (12) to provide the trailing edge flap (4) with a degree of freedom of deflection.

8. The trailing edge flap system of a helicopter blade according to claim 6, It is characterized in that The trailing edge flap (4) is deflected upward or downward by the extension and retraction of the piezoelectric actuator.

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