Rudder surface deflection mechanism and method based on adjustable pre-compression force piezoelectric bimorph

Abstract

The present invention discloses a rudder deflection mechanism based on an adjustable pre-compression force piezoelectric dual-chip and a method thereof. The rudder deflection mechanism mainly comprises a rudder wing shell, a piezoelectric composite dual-chip, and a polymer spiral winding type actuator. The rudder wing shell can rotate around a fixed axis, the root of the piezoelectric composite dual-chip is inserted into the fixed axis, and a voltage with opposite phase is applied to the piezoelectric composite dual-chip to make it bend, and its free end roller can roll or slide in the groove of the trailing edge of the rudder wing shell, thereby generating a normal pressure on the trailing edge of the rudder wing shell to deflect it. When the rudder deflection is required, the polymer spiral winding type actuator is heated to shrink it, and then an axial compression force is applied to the dual-chip, which helps to increase the deflection amount of the rudder. When the rudder deflection is not required, the polymer spiral winding type actuator is not heated, so that it does not generate axial tensile stress, thereby avoiding permanent deformation of the dual-chip under the action of axial pressure for a long time, and improving the life of the piezoelectric composite dual-chip.

Description

Technical Field

[0001] The present invention relates to the field of flight control of micro-unmanned aerial vehicles, and in particular to a control surface deflection mechanism based on a piezoelectric bimorph with adjustable pre-compression force and a method thereof. Background Art

[0002] Piezoelectric bimorphs have a small size and a large bandwidth, and are very suitable for the deflection drive control of the wing and rudder surfaces of micro-aircraft. However, they have the disadvantage of small output displacement, so it is necessary to increase their output displacement by applying axial preload.

[0003] However, due to the initial asymmetry of the structural material of the piezoelectric bimorph, the initial bending will further increase under the action of axial force for a long time, and eventually the bimorph will break. The currently commonly used methods such as putting on a pre-stretched elastic band or spring are uncontrollable methods of applying axial force, and shape memory alloys and shape memory polymers usually have relatively stable characteristics only in the two states before and after the phase change, and it is difficult to accurately control the intermediate phase change state. Therefore, it is impossible to accurately control the pre-compression force, and the cost of traditional shape memory materials is also relatively high. For this reason, it is necessary to develop a continuously controllable axial force application method, that is, the axial force can be removed when not working, and a controllable axial pressure loading method can be accurately applied when working, so as to improve the reliability and service life of the pre-compression piezoelectric bimorph actuator. Summary of the invention

[0004] In order to achieve continuous and controllable adjustment of the pre-compression force of the piezoelectric dual chip and apply it to the control of the rudder deflection of a micro-aircraft, the purpose of the present invention is to provide a design scheme and a control method of the rudder deflection mechanism of a piezoelectric dual chip with adjustable pre-compression force.

[0005] In order to achieve the above-mentioned purpose, the present invention has designed a method of using a power supply to adjust the axial tension of the polymer spiral winding actuator, so as to ensure the precise application of axial pre-pressure to the piezoelectric fiber composite material dual-chip; based on this, opposite-phase voltages are applied to the cantilevered piezoelectric fiber composite material dual-chip to cause it to deflect significantly, and its moving end rolls or slides in the U-shaped groove at the tail of the rudder wing shell, thereby driving the rudder wing shell to rotate around the fixed axis, thereby realizing the deflection of the rudder.

[0006] The present invention specifically adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a rudder deflection mechanism based on an adjustable pre-compression force piezoelectric dual-chip, which includes a rudder wing shell, a fixed shaft, a polymer spiral winding actuator, a piezoelectric fiber composite dual-chip and a sliding shaft; fixed shaft sleeves with prefabricated slots are respectively arranged on both sides of the front end of the rudder wing shell, and U-shaped grooves are respectively arranged on both sides of the tail end, and the opening direction of the U-shaped groove is toward the fixed shaft sleeve; the fixed shaft and the piezoelectric fiber composite dual-chip serve as the supporting structure of the rudder wing shell, and the piezoelectric fiber composite dual-chip also serves as the rudder wing shell deflection drive structure, wherein one end of the piezoelectric fiber composite dual-chip is inserted into the through groove of the fixed shaft and is fixedly connected to the fixed shaft through a first fixing member, and the other end is inserted into the through groove of the sliding shaft and is fixedly connected to the sliding shaft through a second fixing member; first miniature bearings are respectively sleeved on the shaft necks at both ends of the fixed shaft, and the outer rings of the first miniature bearings at both ends are respectively fixedly connected to the fixed shaft sleeves on both sides of the rudder wing shell, so that the rudder wing shell can The rudder wing shell is provided with a plurality of fixed shaft sleeves and a plurality of prefabricated slot bearing sleeves, and the plurality of second micro bearings are provided with a plurality of prefabricated slot bearing sleeves. The rudder wing shell is provided with a plurality of fixed shaft sleeves and a plurality of prefabricated slot bearing sleeves. The rudder wing shell is provided with a plurality of fixed shaft sleeves and a plurality of prefabricated slot bearing sleeves. The plurality of polymer spiral winding actuators are provided with a plurality of heating elements inside. When the polymer spiral winding actuators are heated by the internal heating elements, the plurality of polymer spiral winding actuators can shrink axially as a whole, thereby applying a pre-compression force to the piezoelectric fiber composite material dual crystal chips. The piezoelectric fiber composite material dual crystal chips are bent under the control of an external voltage. When the piezoelectric fiber composite material dual crystal chips are bent, the prefabricated slot bearing sleeves and the U-shaped slot at the tail of the rudder wing shell form a sliding pair, and drive the rudder wing shell to deflect around the fixed axis to output displacement externally.

[0008] Preferably, the two fixed sleeves are respectively arranged on both sides of the thickest chord-wise position of the airfoil of the rudder wing shell, and the prefabricated slot is an annular groove opened in the middle position of the outer peripheral surface of each fixed sleeve; the length of the U-shaped groove is the same as the width of the rudder wing shell; the rudder wing shell is preferably processed by three-dimensional printing.

[0009] Preferably, the front and rear ends of the middle aluminum plate of the piezoelectric fiber composite bimorph both have protruding sections relative to the upper and lower layers of piezoelectric fiber composite materials, and mounting holes for inserting bolts are respectively provided on the protruding sections.

[0010] Preferably, the diameter of the fixed shaft is larger than the diameter of the sliding shaft.

[0011] Preferably, the shaft necks at both ends of the fixed shaft have an interference fit with the inner ring of the first miniature bearing, and the fixed shaft sleeve on the rudder wing shell has an interference fit with the outer ring of the first miniature bearing; the shaft necks at both ends of the sliding shaft have an interference fit with the inner ring of the second miniature bearing, and the prefabricated slot bearing sleeve has an interference fit with the outer ring of the second miniature bearing.

[0012] Preferably, the groove cross-section of the prefabricated groove bearing sleeve is larger than the wire diameter of the polymer spiral winding actuator; and the diameter of the prefabricated groove bearing sleeve is slightly smaller than the groove width of the U-shaped groove.

[0013] Preferably, the polymer spiral winding actuator continuously twists the polymer fiber material and the heat-conducting metal wire into a curled spiral shape while maintaining tension, thereby forming a twisted geometric structure; and a certain length of unspirally wound polymer fiber material and heat-conducting metal wire are retained at both ends of the polymer spiral winding actuator, and the retained polymer fiber material is used as a connecting section to connect the prefabricated slot and the prefabricated slot bearing sleeve, and the retained heat-conducting metal wire is used to connect an external power supply; preferably, a thermistor is embedded in the polymer spiral winding actuator.

[0014] Furthermore, the polymer spiral winding actuator is connected to the prefabricated slot and the prefabricated slot bearing sleeve as follows: the polymer fiber materials that are not spirally wound at both ends are respectively passed through the holes of a wire clamping aluminum sleeve, then bypass the corresponding slot and pass through another hole of the wire clamping aluminum sleeve again, and the protruding length of the polymer fiber material is adjusted so that it is tightly fitted on the corresponding slot, and finally the wire clamping aluminum sleeves at both ends are clamped flat to form two rope loops that are respectively connected to the fixed shaft and the sliding shaft.

[0015] Preferably, the first fixing member and the second fixing member both use matching bolts and nuts.

[0016] In a second aspect, the present invention provides an actuation method for a rudder deflection mechanism using a piezoelectric dual-chip based on an adjustable pre-compression force as described above, the steps of which are as follows: at the beginning of operation, a power supply circuit is first connected to apply a certain power to the heat-conducting metal wire in the polymer spiral winding actuator, so that the temperature of the polymer fiber material increases, resulting in radial thermal expansion of the polymer fiber material, and the highly twisted geometric structure converts the thermal expansion into a torsional torque, causing the polymer spiral winding actuator to shrink as a whole, thereby applying pre-pressure to the piezoelectric fiber composite material dual-chip, measuring the temperature of the polymer fiber material through a thermistor and feedback-adjusting the output power of the power supply circuit, and controlling the temperature at a set value to thereby achieve control of the pre-compression force. system; then, a voltage signal with the same amplitude but a phase difference of 180 degrees is applied to the upper and lower layers of piezoelectric fiber composite materials attached to the surface of the middle layer aluminum plate of the piezoelectric fiber composite dual chip, so that the cantilever beam piezoelectric fiber composite dual chip is bent and deformed, and the bending deformation drives the prefabricated slot bearing sleeve on the sliding shaft to slide or roll in the U-shaped groove at the tail of the rudder wing shell, and exerts pressure on the tail of the rudder wing shell, so as to drive the rudder wing shell to deflect around the fixed axis and output the displacement to the outside; at the end of the work, the piezoelectric fiber composite dual chip is first returned to the initial position by controlling the voltage, and then the power supply circuit is disconnected to stop the heating of the polymer spiral winding actuator, and finally the application of voltage to the piezoelectric fiber composite dual chip is stopped.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The polymer spiral winding actuator proposed in the present invention can realize continuous control of the pre-compression force applied to the piezoelectric fiber composite material bimorph by adjusting the temperature, and the cost is relatively low compared to the shape memory material polymer spiral winding actuator; the output displacement of the piezoelectric fiber composite material bimorph is increased by applying the controllable pre-compression force; the design of the rudder wing shell with a fixed sleeve and a tail U-shaped groove can make the free end of the piezoelectric fiber composite material bimorph slide in the U-shaped groove, thereby driving the rudder to deflect around the fixed axis. The design scheme has a compact structure and can make the piezoelectric fiber composite material bimorph have more stable performance and a longer service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an axonometric diagram of the rudder surface deflection mechanism based on the piezoelectric bimorph with adjustable pre-compression force of the present invention;

[0020] Figure 2 It is an exploded view of the parts of the rudder surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph of the present invention;

[0021] Figure 3 It is an exploded view of the parts of the piezoelectric fiber composite bimorph;

[0022] Figure 4 is a schematic diagram of the structure of a polymer spiral winding actuator;

[0023] Figure 5 It is a schematic diagram of the operation of the rudder deflection mechanism based on the piezoelectric bimorph with adjustable pre-compression force;

[0024] In the figure, the rudder wing shell 1, the fixed sleeve 1-1, the fixed sleeve prefabricated slot 1-2, the U-shaped slot 1-3, the first bolt 2, the fixed shaft 3, the first micro bearing 4, the polymer spiral winding actuator 5, the polymer fiber material 5-1, the thermistor 5-2, the thermal conductive wire 5-3, the wire clamping aluminum sleeve 5-4, the piezoelectric fiber composite dual crystal 6, the first piezoelectric composite material 6-1, the middle layer aluminum plate 6-2, the first piezoelectric composite material 6-3, the sliding shaft 7, the nut 8, the second bolt 9, the second micro bearing 10, the prefabricated slot bearing sleeve 11, and the power supply circuit 12. DETAILED DESCRIPTION

[0025] The present invention will be specifically described below in conjunction with the accompanying drawings:

[0026] like Figure 1 and Figure 2 As shown, in a preferred embodiment of the present invention, a rudder deflection mechanism based on an adjustable pre-compression force piezoelectric bimorph is provided, which mainly includes a rudder wing shell 1, a fixed shaft 3, a polymer spiral winding actuator 5, a piezoelectric fiber composite bimorph 6 and a sliding shaft 7. Among them, a fixed sleeve 1-1 with a prefabricated groove 1-2 is respectively arranged on both sides of the front end of the rudder wing shell 1, and a U-shaped groove 1-3 is respectively arranged on both sides of the tail end, and the opening direction of the U-shaped groove 1-3 faces the fixed sleeve 1-1. The specific setting positions of the fixed sleeve 1-1 and the U-shaped groove 1-3 on the rudder wing shell 1 can be optimized and adjusted according to actual conditions. In this embodiment, the two fixed sleeves 1-1 are respectively arranged on both sides of the thickest chord position of the airfoil of the rudder wing shell 1, and the length of the U-shaped groove 1-3 is the same as the width of the rudder wing shell 1, that is, the U-shaped groove 1-3 integrally passes through the rudder wing shell 1 horizontally. The prefabricated groove 1-2 on the fixed sleeve 1-1 is an annular groove opened in the middle position of the outer peripheral surface of each fixed sleeve 1-1. The control surface wing shell 1 in this embodiment is preferably processed by three-dimensional printing to form a desired shape structure.

[0027] See also Figure 3As shown, the piezoelectric fiber composite material dual chip 6 in this embodiment adopts a three-layer structure, and the middle layer aluminum plate 6-2 is located in the middle. The upper surface of the middle layer aluminum plate 6-2 is pasted with an upper layer of piezoelectric fiber composite material 6-1, and the lower surface is pasted with a lower layer of piezoelectric fiber composite material 6-3. Both upper and lower layers of piezoelectric fiber composite materials can be symmetrically pasted on both sides of the middle layer aluminum plate 6-2 by glue, and the glue can be epoxy resin glue. The two ends of the middle layer 6-2 should be slightly longer than the upper and lower layers of piezoelectric fiber composite materials. The front end and the rear end of the middle layer aluminum plate 6-2 need to have protruding sections relative to the upper and lower layers of piezoelectric fiber composite materials 6-1, and mounting holes 6-2-1 for inserting bolts are respectively opened on the protruding sections at both ends. The piezoelectric fiber composite material dual chip 6 can be controlled by applying voltage to the two layers of piezoelectric fiber composite materials under the control of an external piezoelectric controller. Its principle belongs to the existing technology and will not be repeated.

[0028] The fixed shaft 3 and the piezoelectric fiber composite material bimorph 6 are both located in the rudder wing shell 1, serving as the main supporting structure of the rudder wing shell 1, and the piezoelectric fiber composite material bimorph 6 is also the deflection drive structure of the rudder. Among them, the fixed shaft 3 is used to be fixed to the external aircraft main structure or the main wing structure, so that the entire rudder deflection mechanism is installed on the external aircraft main structure or the main wing structure. One end of the piezoelectric fiber composite material bimorph 6 is inserted into the through groove of the fixed shaft 3, and is fixed to the fixed shaft 3 by the first fixing member, and the other end is inserted into the through groove of the sliding shaft 7, and is fixed to the sliding shaft 7 by the second fixing member. The first fixing member and the second fixing member can adopt any structure that can realize the fixed connection between the piezoelectric fiber composite material bimorph 6 and the shaft. In this embodiment, the first fixing member is two sets of first bolts 2 and nuts 8, and the second fixing member is two sets of second bolts 9 and nuts 8. The first bolt 2 and the second bolt 9 can be inserted into the through holes on the fixed shaft 3 and the sliding shaft 7, and then pass through the mounting hole 6-2-1 on the middle layer aluminum plate 6-2 and then pass out from the bottom of the shaft. The nut 8 can be screwed into the corresponding bolt to achieve fixation. In order to ensure the rigidity of the fixed shaft 3, the fixed shaft 3 can be designed to be thicker. In order to make the piezoelectric fiber composite bimorph 6 inside the rudder as long as possible, the sliding shaft 7 can be designed to be thinner. Therefore, the shaft diameter of the fixed shaft 3 should be larger than the shaft diameter of the sliding shaft 7.

[0029] In addition, first micro bearings 4 are respectively sleeved on the journals at both ends of the fixed shaft 3, and the outer rings of the first micro bearings 4 at both ends are respectively fixedly connected with the fixed shaft sleeves 1-1 at both sides of the rudder wing shell 1, so that the rudder wing shell 1 can rotate as a whole around the fixed shaft 3. The sliding shaft 7 is located in the U-shaped groove 1-3 and the sliding shaft 7 is arranged along the extension direction of the groove body. Second micro bearings 10 are respectively sleeved on the journals at both ends of the sliding shaft 7, and the outer sides of the second micro bearings 10 at both ends are respectively sleeved with prefabricated slot bearing sleeves 11. When installing this structure, the first micro bearings 4 can be sleeved on both ends of the fixed shaft 3, the second micro bearings 10 can be sleeved on both ends of the sliding shaft 7, and the prefabricated slot bearing sleeves 11 can be sleeved on the outer rings of the second micro bearings 10, and then the above-mentioned assembled structure can be installed in the rudder wing shell 1, wherein the outer ring of the first micro bearing 4 is fixed to the fixed shaft sleeve 1-1 in the rudder wing shell, and the prefabricated slot bearing sleeve 11 is placed in the U-shaped groove 1-3 at the tail of the rudder wing shell. This design enables the prefabricated slot bearing sleeve 11 on the sliding shaft 7 of the piezoelectric fiber composite material bimorph 6 to generate normal pressure on the groove wall of the U-shaped groove 1-3 when it bends relative to the fixed shaft 3, thereby driving the rudder wing shell 1 to deflect at a certain angle around the fixed shaft 3. Specifically, the piezoelectric fiber composite material bimorph 6 is bent after the external piezoelectric controller applies voltage. When the piezoelectric fiber composite material bimorph 6 is bent, the prefabricated slot bearing sleeve 11 and the U-shaped groove 1-3 at the tail of the rudder wing shell 1 form a sliding pair that can have a certain relative displacement freedom. At the same time, the driving force generated by the bending of the piezoelectric fiber composite material bimorph 6 can also drive the rudder wing shell 1 to deflect around the fixed shaft 3 and output displacement to the outside.

[0030] In addition, there are two polymer spiral winding actuators 5, one polymer spiral winding actuator 5 is respectively arranged on a set of fixed shaft sleeves 1-1 and prefabricated slot bearing sleeves 11 on each side of the rudder wing shell 1. One end of the polymer spiral winding actuator 5 is sleeved in the prefabricated slot 1-2 on the fixed shaft sleeve 1-1, and the other end is sleeved on the prefabricated slot bearing sleeve 11. A heating element is arranged inside the polymer spiral winding actuators 5 on both sides. When the polymer spiral winding actuators 5 are heated by the internal heating element, they can shrink axially as a whole, thereby applying axial pre-compression force to the piezoelectric fiber composite material bimorph 6. When the rudder surface needs to be deflected, the polymer spiral winding actuator 5 is heated to shrink it, and then axial compression force is applied to the piezoelectric fiber composite material bimorph, which helps to increase the deflection amount of the rudder surface. When the rudder surface is not needed to be deflected, the polymer spiral winding actuator 5 is not heated, so that it does not generate axial tensile stress, thereby avoiding permanent deformation of the piezoelectric fiber composite material bimorph under the action of axial pressure for a long time, and improving the life of the piezoelectric fiber composite material bimorph.

[0031] Generally speaking, the slot cross-section of the prefabricated slot bearing sleeve 11 is larger than the wire diameter of the polymer spiral winding actuator 5, so as to ensure that the fiber rope sleeve does not contact the U-shaped slot 1-3, thereby hindering the sliding of the prefabricated slot bearing sleeve 11 in the U-shaped slot 1-3. At the same time, the diameter of the prefabricated slot bearing sleeve 11 should be slightly smaller than the slot width of the U-shaped slot 1-3, so as to make the prefabricated slot bearing sleeve 11 slide freely in the U-shaped slot 1-3 but also to apply normal pressure to the U-shaped slot 1-3 in time.

[0032] In the above-mentioned rudder deflection mechanism based on adjustable pre-compression force piezoelectric dual chips, in order to ensure stable and reliable connection between the various components, the shaft necks at both ends of the fixed shaft 3 should have an interference fit with the inner ring of the first miniature bearing 4, and the fixed shaft sleeve 1-1 on the rudder wing shell 1 should have an interference fit with the outer ring of the first miniature bearing 4; the shaft necks at both ends of the sliding shaft 7 should have an interference fit with the inner ring of the second miniature bearing 10, and the prefabricated slot bearing sleeve 11 should have an interference fit with the outer ring of the second miniature bearing 10.

[0033] like Figure 4As shown, the polymer spiral winding actuator 5 is an actuator designed based on the characteristics of the polymer fiber material after being heated. It is an artificial muscle that can produce stretch at high temperature by continuously twisting the polymer fiber under a certain tension to a curled spiral shape. In this embodiment, the manufacturing method of the polymer spiral winding actuator 5 is: the polymer fiber material 5-1 (generally nylon 6,6) and the heat-conducting metal wire 5-3 (generally enameled nickel-chromium wire) are continuously twisted to a curled spiral shape while maintaining a specific tension, forming a highly twisted geometric structure. In addition, in order to facilitate the connection of the two ends with the outside, a certain length of the polymer fiber material 5-1 and the heat-conducting metal wire 5-3 that are not spirally wound must be retained at both ends of the polymer spiral winding actuator 5 during the manufacturing process. The retained polymer fiber material 5-1 is used as a connecting section to connect the prefabricated slot 1-2 and the prefabricated slot bearing sleeve 11. In this way, the polymer spiral winding actuator 5 is connected to the prefabricated slot 1-2 and the prefabricated slot bearing sleeve 11 in the following manner: the polymer fiber material 5-1 that is not spirally wound at both ends is passed through the hole of a wire clamping aluminum sleeve 5-4, and then passes through the corresponding slot and then passes through another hole of the wire clamping aluminum sleeve 5-4 again, and the extended length of the polymer fiber material 5-1 is adjusted so that it is tightly sleeved on the corresponding slot, and finally the wire clamping aluminum sleeves 5-4 at both ends are clamped flat to form two rope loops that are respectively sleeved with the fixed shaft 3 and the sliding shaft 7, thereby connecting the piezoelectric fiber composite material bimorph. In addition, the length of the heat-conducting wire 5-3 retained at both ends of the polymer spiral winding actuator 5 can be used to connect to a power source, so as to heat the polymer fiber material. A position on the polymer spiral winding actuator 5 can be selected to embed a thermistor 5-2, and in order to insulate the heat-conducting wire 5-3, it can be fixed with an insulating heat-conducting glue. The temperature information on the polymer spiral winding actuator 5 is obtained through the thermistor 5 - 2 , thereby ensuring that the polymer spiral winding actuator 5 is not damaged by overheating or that the piezoelectric fiber composite bimorph 6 is not damaged by excessive output force.

[0034] like Figure 5As shown, it is an actuation schematic diagram of the above-mentioned rudder deflection mechanism. In one case, when the rudder deflection mechanism is not working, the power supply circuit 12 that provides heating power to the polymer spiral winding actuator 5 is disconnected, so that the polymer spiral winding actuator 5 is not heated, and then the axial pre-compression force is not applied to the piezoelectric fiber composite material bimorph 6, and no voltage is applied to the upper piezoelectric composite material 6-1 and the lower piezoelectric composite material 6-3, so the rudder wing shell 1 does not deflect and is in the initial middle position; when the rudder deflection mechanism is working, the power supply circuit 12 is connected, the polymer spiral winding actuator 5 is heated, and then the axial pre-compression force is applied to the piezoelectric fiber composite material bimorph 6, and the real-time temperature information provided by the thermistor 5-2 is compared with the design temperature, and the temperature on the polymer spiral winding actuator 5 is controlled by controlling the output power of the power supply circuit 12. At the same time, 1500V and -500V voltages are applied to the upper piezoelectric composite material 6-1 and the lower piezoelectric composite material 6-3, respectively, so that the upper piezoelectric composite material 6-1 is stretched and the lower piezoelectric composite material 6-3 is shortened, resulting in a large downward displacement bending of the piezoelectric fiber composite bimorph 6, causing the rudder wing shell 1 to deflect downward around the fixed axis. When a voltage with a phase opposite to the above voltage is applied to the upper piezoelectric composite material 6-1 and the lower piezoelectric composite material 6-3, the rudder wing shell 1 deflects upward around the fixed axis.

[0035] Therefore, by using the above-mentioned rudder deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph, the present invention also provides an actuation method for outputting displacement externally, and the steps are as follows:

[0036] At the beginning of the operation, the power supply circuit 12 is first connected to apply a certain power to the heat-conducting metal wire 5-3 in the polymer spiral winding actuator 5, so that the temperature of the polymer fiber material 5-1 increases, resulting in radial thermal expansion of the polymer fiber material. The highly twisted geometric structure converts the thermal expansion into a torsional moment, causing the polymer spiral winding actuator 5 to shrink as a whole, thereby applying pre-pressure to the piezoelectric fiber composite material dual crystal 6. The temperature of the polymer fiber material 5-1 is measured by the thermistor 5-2, and the output power of the power supply circuit 12 is adjusted by feedback. The pre-compression force is controlled by controlling the temperature at a set value. Then, the middle layer aluminum plate 6-2 of the piezoelectric fiber composite material dual crystal 6 is The upper and lower layers of piezoelectric fiber composite materials attached to the surface apply voltage signals with the same amplitude but a phase difference of 180 degrees, causing the cantilever beam piezoelectric fiber composite dual-chip 6 to bend and deform, and the bending deformation drives the prefabricated slot bearing sleeve 11 on the sliding shaft 7 to slide or roll in the U-shaped groove 1-3 at the tail of the rudder wing shell 1, and exerts pressure on the tail of the rudder wing shell 1, thereby driving the rudder wing shell 1 to deflect around the fixed axis 3 and outputting the displacement to the outside; when the work is completed, the piezoelectric fiber composite dual-chip 6 is first returned to the initial middle position by controlling the voltage, and then the power supply circuit 12 is disconnected to stop the heating of the polymer spiral winding actuator 5, and finally the application of voltage to the piezoelectric fiber composite dual-chip 6 is stopped.

[0037] In summary, the rudder deflection mechanism of the piezoelectric bimorph with adjustable pre-compression force designed by the present invention utilizes the polymer spiral winding actuator 5 with thermistor 5-2, realizes the adjustable and controllable axial pre-compression force of the piezoelectric bimorph, and can improve the working reliability and life of the piezoelectric bimorph actuator. The designed rudder wing shell tail U-shaped groove 1-3 and sliding shaft 7 and prefabricated slot bearing sleeve 11 assembly can better solve the connection problem between the deflection rudder driven by the cantilever piezoelectric bimorph and the wing shell at its free end.

[0038] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A rudder deflection mechanism based on a piezoelectric bimorph with adjustable pre-compression force, It is characterized in that The invention comprises a rudder wing shell (1), a fixed shaft (3), a polymer spiral winding actuator (5), a piezoelectric fiber composite material bimorph (6) and a sliding shaft (7); fixed shaft sleeves (1-1) with prefabricated slots (1-2) are respectively arranged on both sides of the front end of the rudder wing shell (1), and U-shaped grooves (1-3) are respectively arranged on both sides of the rear end, and the opening direction of the U-shaped grooves (1-3) faces the fixed shaft sleeve (1-1); the fixed shaft (3) and the piezoelectric fiber composite material bimorph (6) serve as the support structure of the rudder wing shell (1), and the piezoelectric fiber composite material bimorph (6) also serves as the deflection driving structure of the rudder wing shell (1), wherein one end of the piezoelectric fiber composite material bimorph (6) is inserted into the through groove of the fixed shaft (3) and is fixedly connected to the fixed shaft (3) through a first fixing member, and the other end of the piezoelectric fiber composite material bimorph (6) is inserted into the through groove of the sliding shaft (7) and is fixedly connected to the sliding shaft (7) through a second fixing member; first micro bearings (4) are respectively sleeved on the shaft necks at both ends of the fixed shaft (3), and the first micro bearings at both ends (4) The outer ring is respectively connected to the fixed shaft sleeves (1-1) on both sides of the rudder wing shell (1), and the rudder wing shell (1) can rotate as a whole around the fixed shaft (3); the sliding shaft (7) is located in the U-shaped groove (1-3), and the shaft necks at both ends of the sliding shaft (7) are respectively sleeved with second micro bearings (10), and the second micro bearings (10) at both ends are respectively sleeved with prefabricated slot bearing sleeves (11); a set of fixed shaft sleeves (1-1) and prefabricated slot bearing sleeves (11) on each side of the rudder wing shell (1) ) are respectively provided with a polymer spiral winding actuator (5), one end of the polymer spiral winding actuator (5) is sleeved in a prefabricated groove (1-2) on the fixed shaft sleeve (1-1), and the other end is sleeved on the prefabricated groove bearing sleeve (11); heating elements are provided inside the polymer spiral winding actuators (5) on both sides, and when the polymer spiral winding actuators (5) are heated by the internal heating elements, they can shrink in the axial direction as a whole, thereby applying a pre-compression force to the piezoelectric fiber composite material dual chip (6); The piezoelectric fiber composite material bimorph (6) performs bending actuation under the control of an external voltage. When the piezoelectric fiber composite material bimorph (6) bends, the prefabricated slot bearing sleeve (11) and the U-shaped slot (1-3) at the tail of the rudder wing shell (1) form a sliding pair, and drive the rudder wing shell (1) to deflect around the fixed axis (3) to output displacement externally.

2. The control surface deflection mechanism based on the piezoelectric bimorph with adjustable pre-compression force as claimed in claim 1, Features: The two fixed shaft sleeves (1-1) are respectively arranged on both sides of the thickest chord-wise position of the airfoil of the rudder wing shell (1); the prefabricated groove (1-2) is an annular groove opened in the middle position of the outer peripheral surface of each fixed shaft sleeve (1-1); and the length of the U-shaped groove (1-3) is the same as the width of the rudder wing shell (1).

3. The control surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph as claimed in claim 2, Features: The rudder wing shell (1) is processed by three-dimensional printing.

4. The control surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph as claimed in claim 1, Features: The front and rear ends of the middle layer aluminum plate (6-2) of the piezoelectric fiber composite material dual chip (6) both have protruding sections relative to the upper and lower layers of piezoelectric fiber composite materials, and mounting holes (6-2-1) for inserting bolts are respectively provided on the protruding sections.

5. The control surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph as claimed in claim 1, Features: The shaft diameter of the fixed shaft (3) is greater than the shaft diameter of the sliding shaft (7).

6. The control surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph as claimed in claim 1, Features: The shaft journals at both ends of the fixed shaft (3) are interference fit with the inner ring of the first micro bearing (4), and the fixed shaft sleeve (1-1) on the rudder wing shell (1) is interference fit with the outer ring of the first micro bearing (4); the shaft journals at both ends of the sliding shaft (7) are interference fit with the inner ring of the second micro bearing (10), and the prefabricated groove bearing sleeve (11) is interference fit with the outer ring of the second micro bearing (10).

7. The control surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph as claimed in claim 1, Features: The groove cross-section of the prefabricated groove bearing sleeve (11) is larger than the wire diameter of the polymer spiral winding actuator (5); and the diameter of the prefabricated groove bearing sleeve (11) is slightly smaller than the groove width of the U-shaped groove (1-3).

8. The control surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph as claimed in claim 1, Features: The polymer spiral winding actuator (5) is a device that continuously twists a polymer fiber material (5-1) and a heat-conducting metal wire (5-3) into a curled spiral shape while maintaining tension, thereby forming a twisted geometric structure; and a certain length of polymer fiber material (5-1) and heat-conducting metal wire (5-3) that are not spirally wound are respectively retained at both ends of the polymer spiral winding actuator (5), the retained polymer fiber material (5-1) is used as a connecting section to connect the prefabricated slot (1-2) and the prefabricated slot bearing sleeve (11), and the retained heat-conducting metal wire (5-3) is used to connect an external power source.

9. The control surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph as claimed in claim 7, Features: The polymer spirally wound actuator (5) is embedded with a thermistor (5-2).

10. The control surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph as claimed in claim 8, Features: The polymer spiral winding actuator (5) is connected to the prefabricated slot (1-2) and the prefabricated slot bearing sleeve (11) in the following manner: the polymer fiber material (5-1) which is not spirally wound at both ends is passed through the hole of a wire clamping aluminum sleeve (5-4), then bypasses the corresponding slot and passes through another hole of the wire clamping aluminum sleeve (5-4), the extended length of the polymer fiber material (5-1) is adjusted so that it is tightly sleeved on the corresponding slot, and finally the wire clamping aluminum sleeves (5-4) at both ends are clamped and flattened to form two rope loops which are respectively sleeved on the fixed shaft (3) and the sliding shaft (7).

11. The control surface deflection mechanism based on the adjustable pre-compression force piezoelectric bimorph as claimed in claim 1, Features: The first fixing member and the second fixing member both use matching bolts and nuts.

12. An actuation method of a control surface deflection mechanism using the piezoelectric bimorph with adjustable pre-compression force as claimed in claim 8, It is characterized in that The steps are as follows: at the beginning of operation, the power supply circuit (12) is first connected to apply a certain power to the heat-conducting metal wire (5-3) in the polymer spiral winding actuator (5), so that the temperature of the polymer fiber material (5-1) increases, resulting in radial thermal expansion of the polymer fiber material. The highly twisted geometric structure converts the thermal expansion into a torsional torque, causing the polymer spiral winding actuator (5) to shrink as a whole, thereby applying pre-pressure to the piezoelectric fiber composite material dual chip (6), and the temperature of the polymer fiber material (5-1) is measured by the thermistor (5-2) and the output power of the power supply circuit (12) is feedback-regulated, and the pre-compression force is controlled by controlling the temperature at a set value; then, the middle layer aluminum plate (6) of the piezoelectric fiber composite material dual chip (6) is pressed. -2) applying voltage signals with the same amplitude but a phase difference of 180 degrees to the upper and lower layers of piezoelectric fiber composite materials attached to the surface, so that the cantilever beam type piezoelectric fiber composite dual chip (6) is bent and deformed, and the bending deformation drives the prefabricated slot bearing sleeve (11) on the sliding shaft (7) to slide or roll in the U-shaped groove (1-3) at the tail of the rudder wing shell (1), and applies pressure to the tail of the rudder wing shell (1), so as to drive the rudder wing shell (1) to deflect around the fixed axis (3) and output displacement to the outside; when the work is completed, the piezoelectric fiber composite dual chip (6) is first returned to the initial position by controlling the voltage, and then the power supply circuit (12) is disconnected to stop heating the polymer spiral winding actuator (5), and finally the application of voltage to the piezoelectric fiber composite dual chip (6) is stopped.

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