CN114671017A - Trailing edge flap system of helicopter blade based on piezoelectric material - Google Patents

Abstract

The embodiment of the invention discloses a trailing edge flap system of a helicopter blade based on a piezoelectric material, relates to the technical field of rotary wing aircrafts, and can change the deflection angle of a trailing edge flap. The invention includes: the piezoelectric actuator is arranged in the blade, and when driving voltage is applied to the piezoelectric actuator, the piezoelectric actuator is stretched or shortened to deform, and the trailing edge flap is directly or indirectly driven to deflect. When the applied voltage is removed, the piezoelectric actuator does not deform any more, and the trailing edge flap returns to the horizontal position, so that the active deflection of the trailing edge flap within a certain range is realized, and the performance of the rotor wing is improved. The paddle carrying the trailing edge flap can change the deflection angle of the trailing edge flap according to the flight working condition, further influences the attack angle and the lift force, and has the functions of improving the efficiency of the rotor wing, improving the flight working condition and reducing the vibration and the noise of the rotor wing.

Description

Trailing edge flap system of helicopter blade based on piezoelectric material

Technical Field

The invention relates to the technical field of rotary wing aircrafts, in particular to a trailing edge flap system of a helicopter blade based on a piezoelectric material.

Background

The rotorcraft has a very wide application range, benefits from the vertical take-off and landing capability and the excellent low-altitude performance, is used for civil use from military use, and has irreplaceable effects on many occasions such as military operations, emergency rescue and relief work, material transportation and personnel carrying.

The main rotor plays a leading role in the rotor craft, and provides the helicopter with lift force for overcoming gravity, pulling force for horizontal flight and transverse and longitudinal control moments for controlling the attitude of the helicopter body. But at the same time, the special working condition of the rotor wing can bring higher vibration, noise and the like to the helicopter. In order to solve the problem, a scheme that the piezoelectric actuator drives the blade to actively twist is provided at present, namely, the twisting angle of the blade is changed to improve the flight condition and improve the flight performance.

However, how to change the deflection angle of the trailing edge flap to further reduce the vibration and noise of the rotor wing is a design difficulty, and needs to be researched and solved.

Disclosure of Invention

Embodiments of the present invention provide a trailing edge flap system for a helicopter blade based on piezoelectric material that is capable of varying the deflection angle of the trailing edge flap.

In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:

the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are arranged between the skin (1) and the filling material (3) of the paddle; 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 crossbeam (2), and the tail end of the piezoelectric actuator A (5) and the tail end of the piezoelectric actuator B (6) are both floating; a groove is formed 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 arranged 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 with the piezoelectric actuator A (5) and the piezoelectric actuator B (6) through glue, and the tail end of the metal wire is connected with the trailing edge flap (4) through a wire clamp; the trailing edge flap (4) is connected with the main body of the blade through two hinges (10), and the hinge (10) is arranged between the front end of the trailing edge flap (4) and the blade skin (1); two ends of the elastic skin A (8) are respectively connected to the skin (1) and the trailing edge flap (4), and 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 penetrates through an opening at the rear end of the skin (1); holes are formed in the front end of the trailing edge flap (4) and the rear end of the blade skin (1), and a hinge (10) is installed in an interference fit mode.

The metal line includes: wire A7(i) to wire D7(iv), the clip comprising: clip a7(v) to clip D7 (viii); wires a7(i) to D7(iv) pass through apertures in the rear end of the skin (1); the head ends of the 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), penetrate through the filling material (3) and the skin (1), and are finally connected to the trailing edge flap (4) respectively through a wire clamp A7(v) and a wire clamp D7 (vi); wire C7(iii) and wire D7(iv) emanate from the rear end of the piezoelectric actuator B (6), pass through the filler material (3) and the skin (1), and finally are each connected to the trailing edge flap (4) by a clip a7(vii) and a clip D7(viii), respectively. A spacer 7(ix) is disposed between the filler material (3) and the metal line.

The two ends of the hinge (10) are tapered pins which are respectively connected with the main body of the blade and the trailing edge flap (4) through interference fit.

The piezoelectric actuator B (6) is arranged between the skin (1) and the filling material (3) of the paddle, except that the front end of the piezoelectric actuator B (6) is fixedly arranged at the joint between the skin (1) and the crossbeam (2), the rest parts of the piezoelectric actuator B (6) are floated, so that the rear end of the piezoelectric actuator B (6) generates telescopic displacement along the skin direction.

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

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 provide the deflection freedom degree for the trailing edge flap (4) by utilizing the elasticity of the flexible hinge (12).

The trailing edge flap (4) is deflected upwards or downwards by the stretching of the piezoelectric actuator.

According to the trailing edge flap system of the helicopter blade based on the piezoelectric material, provided by the embodiment of the invention, the piezoelectric actuator is arranged in the blade, and when a driving voltage is applied to the piezoelectric actuator, the piezoelectric actuator is extended or shortened to deform, so that the trailing edge flap is directly or indirectly driven to deflect. When the applied voltage is removed, the piezoelectric actuator does not deform any more, and the trailing edge flap returns to the horizontal position, so that active deflection of the trailing edge flap within a certain range is realized, and the performance of the rotor wing is improved. The paddle carrying the trailing edge flap can change the deflection angle of the trailing edge flap according to the flight working condition, further influences the attack angle and the lift force, and has the functions of improving the efficiency of the rotor wing, improving the flight working condition and reducing the vibration and the noise of the rotor wing.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of a general assembly structure of a common hinge trailing edge flap system of a helicopter blade based on piezoelectric materials, which is provided by an embodiment of the invention;

FIG. 2 is a schematic structural diagram of a grooved filler material according to an embodiment of the present invention;

FIG. 3 is a schematic illustration of drive train installation details provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of an overall structure of a transmission system according to an embodiment of the present invention;

FIG. 5 is a schematic view of an opening of a skin structure provided by an embodiment of the invention;

FIG. 6 is a schematic view of a hinge structure provided in an embodiment of the present invention;

FIG. 7 is a schematic diagram of a piezoelectric actuator wire arrangement according to an embodiment of the present invention;

FIG. 8 is a schematic view of a flexible skin installation provided by an embodiment of the invention;

FIG. 9 is a schematic view of the extreme positions of flap deflection provided by an embodiment of the present invention.

FIG. 10 is a schematic view of a second piezoelectric material-based helicopter blade flexural hinge trailing edge flap system assembly configuration provided by an embodiment of the invention;

FIG. 11 is a schematic view of a flexible hinge connection structure provided by an embodiment of the present invention;

FIG. 12 is a schematic view of a flap deflection limit position provided by an embodiment of the present invention;

FIG. 13 is a schematic diagram of a third piezoelectric material-based helicopter blade flexural hinge trailing edge flap system general assembly configuration provided by an embodiment of the present invention;

FIG. 14 is a schematic view of a flap deflection limit position provided by an embodiment of the present invention;

wherein the reference numerals in the drawings denote: skin-1, girder-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, electric 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) and gasket-7 (ix).

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention. As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In the current research, it is found that if the main rotor blade does not carry the trailing edge flap, the main rotor blade cannot adapt to the requirements of different aerodynamic environments, not only is the efficiency low, but also great vibration and noise are generated. In response to this problem, the present embodiment provides a design concept and improves the design. In particular, a certain range of active deflection of the trailing edge flap is achieved directly or indirectly by deformation of the piezoelectric actuator. The trailing edge flap has the characteristics of light weight, good driving effect and high response speed. According to the flight condition, the trailing edge flap is actively deflected, so that the performance of the rotor wing can be improved, and vibration and noise are reduced. The design objective of this embodiment is primarily to achieve a design that changes the deflection angle of the trailing edge flap, while the general design idea can be implemented to the ground as at least three alternative trailing edge flap systems for helicopter blades based on piezoelectric materials.

A first trailing edge flap system of a helicopter blade based on piezoelectric material, as shown in fig. 1, includes:

the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are arranged between the skin (1) and the filling material (3) of the blade.

In the actual production process, a groove with a suitable size (in the finished product state after installation, the groove and the skin form a cavity) can be formed in the filling material, as shown in fig. 2, and used for installing components such as the piezoelectric actuator, the transmission system, the hinge, the electric wire and the like which need to be installed inside the blade. The design of the specific size of the groove and the general method for forming the groove belong to the common knowledge means familiar to those skilled in the art, and therefore, the detailed description thereof is omitted here. In the mainstream products at present, the filling material can be a filling material, such as a polystyrene filling material.

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 crossbeam (2), and the tail end of the piezoelectric actuator A (5) and the tail end of the piezoelectric actuator B (6) are both floated, 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.

A groove is formed in the filling material (3), and a piezoelectric actuator A (5), a 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 A (5) and the piezoelectric actuator B (6) are connected to the trailing edge flap (4) through the metal wire. A shim 7(ix) is disposed between the filler material (3) and the metal wire for providing support and reducing wear. The details are shown in fig. 3.

The metal wire penetrates through an opening at the rear end of the skin (1).

The head end of metal wire passes through glue and piezoelectric actuator A (5) and piezoelectric actuator B (6) fixed connection, the tail end of metal wire passes through the fastener and links to each other with trailing edge flap (4), as shown in fig. 4.

Trailing edge flap (4) with the main part of paddle is connected through two hinges (10), and trailing edge flap (4) front end and paddle covering (1) rear end trompil for installation hinge (10), trailing edge flap (4) upwards or deflect downwards through the flexible of piezoelectric actuator A (5) and piezoelectric actuator B (6). The two ends of the hinge (10) are tapered pins and are respectively connected with the main body of the paddle and the trailing edge flap (4) through interference fit. The blade skin opening structure is shown in fig. 5, and the hinge structure is shown in fig. 6.

The connection of the wires (11) required to drive the piezoelectric actuator is shown in fig. 7.

Two ends of the elastic skin A (8) are respectively connected to the skin (1) and the trailing edge flap (4), and two ends of the elastic skin B (9) are also respectively connected to the skin (1) and the trailing edge flap (4). And the connection points of 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 elastic skin a (8) and the elastic skin B (9) are connected at both ends to the skin (1) and the trailing edge flap (4), respectively, as shown in fig. 8, so that the blade maintains an aerodynamic profile when the trailing edge flap (4) is deflected.

In this embodiment, the trailing edge flap is connected with the paddle main body through two hinges, and two floated piezoelectric actuators are symmetrically distributed in the paddle and are connected to the trailing edge flap through a metal wire and a wire clamp, and when applying a driving voltage to a piezoelectric material, the piezoelectric material is deformed, and the trailing edge flap is pulled to deflect through the metal wire, and when the voltage is not applied, the piezoelectric material recovers the original length, and the trailing edge flap is driven to reset. Fig. 9 shows the initial position of the trailing edge flap deflection and the two extreme positions of the upward and downward deflection.

In this embodiment, the metal line includes: wire A7(i) to wire D7(iv), the clip comprising: clip a7(v) to clip D7 (viii); wires a7(i) to D7(iv) pass through apertures in the rear end of the skin (1). The head ends of the 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).

As shown in fig. 4, the tail end of the wire a7(i) is connected to the trailing edge flap (4) through a wire clamp a7(v), the tail end of the wire a7(ii) is connected to the trailing edge flap (4) through a wire clamp a7(vi), the tail end of the wire a7(iii) is connected to the trailing edge flap (4) through a wire clamp a7(vii), and the tail end of the wire a7(iv) is connected to the trailing edge flap (4) through a wire clamp a7 (viii).

Specifically, the front ends of the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are fixed between the skin (1) and the crossbeam (2), and grooves for accommodating the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are formed in the filling material (3). When installing in packing material (3) piezoelectric actuator A (5) and piezoelectric actuator B (6), piezoelectric actuator A (5) and piezoelectric actuator B (6) are in the recess of packing material (3) completely to there is the allowance for movement. The piezoelectric actuator B (6) is arranged between the skin (1) and the filling material (3) of the paddle, the front end of the piezoelectric actuator B is fixed between the skin (1) and the crossbeam (2), the rest part of the piezoelectric actuator B is floating, and the rear end of the piezoelectric actuator B (6) can generate telescopic displacement along the skin direction. The rear end of the piezoelectric actuator B (6) is connected to the trailing edge flap (4) through a wire C7(iii) and a wire D7 (iv). The lower part of the filling material (3) is provided with a groove for placing the piezoelectric actuator B (6), the metal wire C7(iii), the metal wire D7(iv), the electric wire (11) and the gasket 7(ix), and the rear end of the skin (1) is provided with an opening for passing through the metal wire C7(iii) and the metal wire D7 (iv). The trailing edge flap (4) is connected with the main body of the blade through a flexible hinge (12), and the flexible hinge (12) and the skin (1) are integrally formed during manufacturing. Two ends of the elastic skin A (8) are connected with the skin (1) and the trailing edge flap (4) through glue.

Specifically, the wire a7(i) and the 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) by the clip a7(v) and the clip D7(vi), respectively. Wire C7(iii) and wire D7(iv) emanate from the rear end of the piezoelectric actuator B (6), pass through the filler material (3) and the skin (1), and finally are each connected to the trailing edge flap (4) by clip a7(vii) and clip D7(viii), respectively. Wherein, in the transmission system (7), a metal wire C7(iii) and a metal wire D7(iv) are sent out 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 rear edge flap (4) through a wire clamp C7(vii) and a wire clamp D7(viii), and a gasket 7(ix) is arranged between the filling material (3) and the metal wire for providing support and reducing abrasion.

A second piezoelectric material-based trailing edge flap system for a helicopter blade provided in the present embodiment, as shown in fig. 10, includes:

and the piezoelectric actuator B (6) is arranged between the skin (1) and the filling material (3) of the blade, the front end of the piezoelectric actuator B (6) is fixed between the skin (1) and the crossbeam (2), and the rest part of the piezoelectric actuator B (6) is floated, so that the rear end of the piezoelectric actuator B (6) can generate telescopic displacement along the skin direction.

A groove is provided in the filling material (3), in which groove the piezoelectric actuator B (6), the metal wire, the electric wire (11) and the shim 7(ix) are mounted, wherein the piezoelectric actuator B (6) is connected to the trailing edge flap (4) by means of the metal wire. A shim 7(ix) is disposed between the filler material (3) and the metal wire for providing support and reducing wear.

The trailing edge flap (4) is connected with the main body of the blade through a flexible hinge (12), and the flexible hinge (12) and the skin (1) are integrally formed during manufacturing.

In the actual production process, the composite material laying process is usually adopted, the laying is reasonably arranged, and the integral skin and the flexible hinge are directly manufactured, as shown in fig. 11. The layering process involved is a common knowledge means well known to those skilled in the art and therefore will not be described in detail in this embodiment.

In this embodiment, the remaining portions are the same as those in the previous embodiment except for the number of piezoelectric actuators, the number of wires, the number of elastic skins, and the hinge selection and installation.

In the embodiment, the trailing edge flap (4) is deflected upwards or downwards by stretching and contracting the piezoelectric actuator B (6). Fig. 12 shows the initial position of the trailing edge flap deflection and the extreme positions of the upward and downward deflection.

In this embodiment, the trailing edge flap is connected with the paddle main body through the flexible hinge, and a slice of floated piezoelectric actuator distributes in the paddle bottom, is connected to the trailing edge flap through metal wire and fastener, and when applying drive voltage to piezoelectric material, piezoelectric material takes place to deform, through the deflection of metal wire pulling trailing edge flap, and flexible hinge stores elastic potential energy simultaneously, and when cancelling to apply voltage, piezoelectric material resumes former length, and the elasticity of flexible hinge makes the trailing edge flap reset.

The third trailing edge flap system of a helicopter blade based on piezoelectric material provided in the present embodiment, as shown in fig. 13, includes:

the trailing edge flap (4) is an extension of the blade structure and is of a closed-cell structure.

In the actual production process, the closed cell structure can be processed through reasonable layering, and the related layering process belongs to a common knowledge means familiar to a person skilled in the art, so that details are not described in the embodiment.

The piezoelectric actuator A (5) and the piezoelectric actuator B (6) are arranged on the inner side of the skin (1) of the trailing edge flap (4) and are integrally positioned between the skin (1) and the foam (3). The piezoelectric actuator A (5) and the piezoelectric actuator B (6) are tightly bonded with the skin (1) through glue, so that the deformation of the piezoelectric actuator A and the piezoelectric actuator B is transferred to the skin (1).

In the embodiment, the skin is displaced by the extension and contraction of the piezoelectric actuator B (6), and the elasticity of the trailing edge flap (4) enables the trailing edge flap to deflect upwards and downwards. Fig. 14 shows the initial position of the trailing edge flap deflection and the extreme position of the downward deflection.

In this embodiment, the trailing edge flap is the extension of paddle structure, and two piezoelectric actuator pass through glue and glue in the upper and lower covering department of trailing edge flap, and when applying drive voltage to piezoelectric material, piezoelectric material takes place to deform, drives the paddle and produces elastic deformation, and when cancelling the applied voltage, the elasticity of paddle self orders about the reset of trailing edge flap. The invention is suitable for the main blade of the rotor craft.

The specific working principle of the embodiment can be understood as follows: conventional paddle does not install the trailing edge flap, and the wing section is fixed, can't adapt to different aerodynamic environment's demand, and is not only inefficient, still produces great vibrations and noise, and can promote the rotor performance through the initiative deflection of trailing edge flap behind the installation trailing edge flap, reduces vibrations and noise simultaneously. When a helicopter with the helicopter blade flap system made of piezoelectric materials flies forwards, a controller sends out signals for controlling the deflection of the trailing edge flap according to the working condition of a rotor wing and the aerodynamic environment. When the deflection control is not performed, the piezoelectric actuator is operated. No driving voltage is applied, no driving force is generated, no deformation occurs, and the trailing edge flap is in an initial position because the trailing edge flap is not subjected to additional torque. When the controller sends a deflection signal, voltage is applied to the piezoelectric actuator, so that the piezoelectric actuator is extended or shortened, and torsion moment is directly or indirectly generated on the trailing edge flap to deflect the trailing edge flap. When no driving voltage is applied, the piezoelectric actuator restores the original length, and the trailing edge flap returns to the original position again. The deflection process of the trailing edge flap influences the aerodynamic shape of the blade, and the dynamic deflection of the trailing edge flap adapts to different aerodynamic environments, so that the efficiency of the rotor wing is improved, and the vibration and the noise are reduced. Meanwhile, the flap system based on the piezoelectric material is an active device, and can be actively deflected according to the requirement so as to adapt to different working conditions according to different purposes.

All the embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, the apparatus embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the description of the method embodiments for relevant points. The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (10)

1. A piezoelectric material based trailing edge flap system for a helicopter blade, comprising:

the piezoelectric actuator A (5) and the piezoelectric actuator B (6) are arranged 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 crossbeam (2), and the tail end of the piezoelectric actuator A (5) and the tail end of the piezoelectric actuator B (6) are both floating;

A groove is formed 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 arranged 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 with the piezoelectric actuator A (5) and the piezoelectric actuator B (6) through glue, and the tail end of the metal wire is connected with the trailing edge flap (4) through a wire clamp;

the trailing edge flap (4) is connected with the main body of the blade through two hinges (10), and the hinge (10) is arranged between the front end of the trailing edge flap (4) and the blade skin (1);

two ends of the elastic skin A (8) are respectively connected to the skin (1) and the trailing edge flap (4), and two ends of the elastic skin B (9) are also respectively connected to the skin (1) and the trailing edge flap (4).

2. The trailing edge flap system of a helicopter blade according to claim 1 wherein the wire passes through an aperture in the aft end of the skin (1);

holes are formed in the front end of the trailing edge flap (4) and the rear end of the blade skin (1), and a hinge (10) is installed in an interference fit mode.

3. A trailing edge flap system for a helicopter blade according to claim 1 wherein said wire comprises: wire A7(i) to wire D7(iv), the clip comprising: clip a7(v) to clip D7 (viii);

Wires a7(i) to D7(iv) pass through the opening at the rear end of the skin (1);

the head ends of the 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).

4. The trailing edge flap system of a helicopter blade according to claim 3 wherein wire A7(i) and wire B7(ii) run from the rear end of the piezoelectric actuator A (5), through the filler material (3) and the skin (1), and finally are each connected to the trailing edge flap (4) by means of a clip A7(v) and a clip D7(vi), respectively;

wire C7(iii) and wire D7(iv) emanate from the rear end of the piezoelectric actuator B (6), pass through the filler material (3) and the skin (1), and finally are each connected to the trailing edge flap (4) by clip a7(vii) and clip D7(viii), respectively.

5. The trailing edge flap system of a helicopter blade according to claim 1 wherein a shim 7(ix) is disposed between the filler material (3) and the wire.

6. A trailing edge flap system for a helicopter blade according to claim 1 wherein the hinge (10) has tapered pins at each end which are connected by interference fit to the body of the blade and to the trailing edge flap (4) respectively.

7. The trailing edge flap system of a helicopter blade according to claim 1 or 3 wherein the piezoelectric actuator B (6) is mounted between the skin (1) and the filler material (3) of the blade, the remaining part of the piezoelectric actuator B (6) being floating, except for the front end of the piezoelectric actuator B (6) being fixedly mounted at the connection between the skin (1) and the girder (2), so that the rear end of the piezoelectric actuator B (6) is telescopically displaced in the direction of the skin.

8. The trailing edge flap system of a helicopter blade according to claim 7 wherein the rear end of the piezoelectric actuator B (6) is connected to the trailing edge flap (4) by wire C7(iii) and wire D7 (iv);

the trailing edge flap (4) is connected with the main body of the blade through a flexible hinge (12), wherein the flexible hinge (12) and the skin (1) are integrally formed when being manufactured;

two ends of the elastic skin B (9) are respectively connected with the skin (1) and the trailing edge flap (4) through glue.

9. Trailing edge flap system of a helicopter blade according to claim 8 characterized in that the flexible hinge (12) is made of the same material as the skin (1), and the body of the blade, the trailing edge flap (4) and the flexible hinge (12) are integrally formed during processing in order to provide the trailing edge flap (4) with freedom of deflection by the elasticity of the flexible hinge (12).

10. The trailing edge flap system of a helicopter blade according to claim 8 wherein the trailing edge flap (4) is deflected upwards or downwards by the extension and retraction of a piezoelectric actuator.

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