CN118264149B - A planar three-degree-of-freedom inertial stepping piezoelectric actuator - Google Patents

Abstract

The invention discloses a planar three-degree-of-freedom inertial stepping piezoelectric actuator, which belongs to the field of piezoelectric drive technology and comprises a base, a slider, a guide rail A, a guide rail B, a driving mechanism and a movable rotor; the lower surface of the slider is symmetrically and integrally processed with the guide rail B, the lower surface of the slider is frictionally connected to the upper surface of the base, and the inner side surface of the guide rail B is frictionally connected to the outer side surface of the base along the X-axis direction; the guide rail A is symmetrically fixed on the lower surface of the driving mechanism, the guide rail A and the lower surface of the driving mechanism form a second slide groove, and the upper part of the slider is assembled in the second slide groove; the driving mechanism comprises a fixed frame, a piezoelectric chip, a driving ring and a connecting hinge; the fixed frame is fixedly connected to the guide rail A; the bending deformation of the piezoelectric chip in the driving mechanism driven by different excitation signals is utilized to realize linear displacement or rotational angular displacement output in different directions, thereby realizing linear displacement along the X-axis direction and the Y-axis direction in the actuator plane and rotational angular displacement output around the Z-axis.

Description

A planar three-degree-of-freedom inertial stepping piezoelectric actuator

Technical Field

The invention belongs to the technical field of piezoelectric drive, and in particular relates to a planar three-degree-of-freedom inertial stepping piezoelectric actuator.

Background technique

Piezoelectric drive technology is a key technology for modern high/cutting-edge equipment. In recent years, with the rapid development of many fields such as biomedicine, optical engineering, aerospace, and robotics, there is an urgent need for multi-degree-of-freedom actuators. Multi-degree-of-freedom precision actuators based on piezoelectric drive technology have significant advantages such as simple structure, large stroke, high resolution, and no electromagnetic interference. They have broad application prospects in many fields such as precision drive and positioning. For this reason, many scholars at home and abroad have conducted extensive research on multi-degree-of-freedom piezoelectric actuators.

Existing multi-DOF piezoelectric actuators mostly use multiple single-DOF piezoelectric actuators driven by piezoelectric stacks in series or in parallel to meet the requirements of multiple DOF. This type of multi-DOF piezoelectric actuator requires multiple parts to work together to meet the use conditions of multiple DOF, which can easily make the structure complicated, the degree of integration low, and the space occupied larger, thereby increasing the overall control difficulty. In addition, the piezoelectric stack is large in size and cannot withstand negative voltage. The power requirements for the excitation power supply are relatively strict and the cost is high, which is not conducive to the application of piezoelectric actuators in a wider range. Therefore, the development of a planar three-DOF inertial stepping piezoelectric actuator with a compact structure, reliable and easy excitation method, and high positioning accuracy can solve the shortcomings of existing multi-DOF piezoelectric actuators to a certain extent and broaden the application range of piezoelectric actuators.

Summary of the invention

The present invention aims to solve the problems that traditional multi-degree-of-freedom piezoelectric actuators require multiple parts to cooperate with each other, realize power output through complex mechanical structures, have low integration and complex control. A planar three-degree-of-freedom inertial stepping piezoelectric actuator is proposed. The present invention is based on the inertial stepping principle and adopts a piezoelectric chip as a driving unit. It has a compact structure, a reliable and easy excitation method, high positioning accuracy and can realize three-degree-of-freedom precision stepping motion with nanometer-level resolution and millimeter-level working stroke of one rotation and two straight lines in a plane without motion interference.

A planar three-degree-of-freedom inertial stepping piezoelectric actuator comprises a base, a slider, a guide rail A, a guide rail B, a driving mechanism and a moving-rotor;

There is a circular hole in the center of the base;

The lower surface of the slider is symmetrically integrally processed with a guide rail B, the guide rail B and the lower surface of the slider form a first slide groove, the lower surface of the slider is frictionally connected with the upper surface of the base, and the inner side surface of the guide rail B is frictionally connected with the outer side surface of the base along the X-axis direction;

There are two guide rails A, which are symmetrically fixed on the lower surface of the driving mechanism. The guide rails A and the lower surface of the driving mechanism form a second slide groove, and the upper part of the slider is assembled in the second slide groove;

The driving mechanism includes a fixed frame, a piezoelectric chip, a driving ring and a connecting hinge; the fixed frame is fixedly connected to the guide rail A; the piezoelectric chip includes a piezoelectric chip A, a piezoelectric chip B, a piezoelectric chip C and a piezoelectric chip D; the piezoelectric chip A and the piezoelectric chip D are connected to the fixed frame through a connecting hinge; the piezoelectric chip B is connected to the piezoelectric chip A and the driving ring through a connecting hinge; the piezoelectric chip C is connected to the piezoelectric chip D and the driving ring through a connecting hinge; the piezoelectric chip A and the piezoelectric chip B are perpendicular to each other, and the piezoelectric chip C and the piezoelectric chip D are perpendicular to each other; the driving ring is coaxially fixedly connected to the moving-rotor;

The bending deformation of the piezoelectric chip in the driving mechanism under different excitation signals is used to achieve linear displacement or angular displacement output in different directions, thereby realizing precise stepping motion output with three degrees of freedom in the actuator plane, including linear displacement along the X-axis and Y-axis directions and angular displacement around the Z-axis.

Preferably, four threaded holes are arranged around the base, and the threaded holes are used to fix the base to the workbench through connecting pieces.

Preferably, three threaded holes are processed on the outer side surfaces on both sides of the guide rail B. The threaded holes are used to adjust the first adjusting bolt of the preload force between the base and the guide rail B. The friction force between the base and the guide rail B is controlled by adjusting the position of the first adjusting bolt, thereby adjusting the stepping accuracy of the actuator along the linear displacement of the X-axis.

Preferably, the slider and the guide rail B are processed from a whole piece of quenched 65Mn spring steel.

Preferably, three second adjusting bolts are installed on the outer side of guide rail A, and guide rail A and the second adjusting bolts work together. The friction between the slider and guide rail A is controlled by adjusting the position of the second adjusting bolts, thereby adjusting the stepping accuracy of the actuator's linear displacement along the Y-axis.

Preferably, the piezoelectric chip A and the piezoelectric chip D are composed of an elastic sheet and a piezoelectric ceramic sheet connected to the outside of the elastic sheet, and the piezoelectric chip B and the piezoelectric chip C are composed of an elastic sheet and a piezoelectric ceramic sheet connected to both sides of the elastic sheet.

Preferably, a center hole is provided in the middle portion of the driving ring, and the center hole cooperates with the rotor-rotor connecting shaft to realize the action output of the actuator.

Preferably, the fixing frame, the elastic sheet in the piezoelectric chip, the connecting hinge, and the driving ring are processed from a whole piece of quenched 65Mn spring steel.

Preferably, the movable rotor is a disc-shaped structure, and the lower surface of the movable rotor is connected to a connecting shaft with an internal thread, and the connecting shaft is connected to the third adjusting bolt through the center hole of the middle part of the driving ring, the elastic ring, and the gasket in sequence, wherein the diameter of the connecting shaft is smaller than the diameter of the center hole of the middle part of the driving ring, and the connecting shaft and the center hole of the middle part of the driving ring are transitionally matched to ensure that the outer surface of the connecting shaft is in frictional contact with the center hole of the middle part of the driving ring, and the purpose of adjusting the pre-tightening friction between the movable rotor and the driving ring is achieved by controlling the tightening degree of the third adjusting bolt.

Compared with the prior art, the present invention has the following beneficial effects:

The present invention utilizes the bending deformation of the piezoelectric chip under the excitation of the sawtooth wave driving voltage, and finally realizes the precise stepping motion with nanometer-level resolution and millimeter-level working stroke with three degrees of freedom, including linear displacement in the X-axis direction and the Y-axis direction and rotational angular displacement around the Z-axis in the plane, under the mutual cooperation of the base, the slider, the driving mechanism, the guide rail A, the guide rail B and the movable rotor;

The present invention has flexible conversion of each degree of freedom, and can convert between the three degrees of freedom by controlling the input form of the piezoelectric chip signal, without structural interference problems, rapid response and flexible conversion;

The present invention has a simple and compact structure, a small size, a high degree of integration, a fast response, is not subject to electromagnetic interference, has flexible conversion of various degrees of freedom and is easy to control. It has good application prospects in technical fields such as aerospace, integrated circuits, optical equipment, and micro-electromechanical systems, provides a new design idea for planar three-degree-of-freedom piezoelectric actuators, and broadens the application scope of piezoelectric actuators.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a three-dimensional structure of the present invention;

Fig. 2 is a front view of the present invention;

Fig. 3 is a side view of the present invention;

FIG4 is a top view of the present invention;

FIG5 is a bottom view of the present invention;

FIG6 is an exploded view of the pre-tightening bolt, gasket, and elastic ring of the present invention;

FIG7 is a driving signal waveform diagram of the present invention; wherein (a) is an in-phase sawtooth waveform diagram, and (b) is an out-of-phase sawtooth waveform diagram;

FIG8 is a schematic diagram of the working principle of the present invention for outputting precise stepping linear motion along the positive direction of the X-axis;

FIG9 is a schematic diagram of the working principle of the present invention for outputting precise stepping linear motion along the positive direction of the Y axis;

FIG. 10 is a schematic diagram showing the working principle of the present invention for outputting precise stepping rotational motion clockwise around the Z axis.

In the figure: 1-1, fixed frame; 1-2, driving ring; 1-3, piezoelectric chip A; 1-4, piezoelectric chip B; 1-5, connecting hinge; 1-6, piezoelectric chip C; 1-7, piezoelectric chip D;

2. Moving - rotor; 3. Base;

4. Slider; 4-1. Guide rail B;

5. Guide rail A; 6. First adjusting bolt; 7. Second adjusting bolt; 8. Connecting bolt;

9-1, third adjusting bolt; 9-2, gasket; 9-3, elastic ring.

Detailed ways

Referring to FIG. 1 to FIG. 6 , a planar three-degree-of-freedom inertial stepping piezoelectric actuator includes a base 3, a slider 4, a guide rail A5, a guide rail B4-1, a driving mechanism and a moving-rotor 2;

A circular hole is opened in the center of the base 3, and four threaded holes are arranged around it. The threaded holes can be used to fix the base 3 to the workbench through connecting pieces;

The lower surface of the slider 4 is symmetrically integrally processed with a guide rail B4-1, the guide rail B4-1 and the lower surface of the slider 4 form a first slide groove, the lower surface of the slider 4 is frictionally connected to the upper surface of the base 3, and the inner side surface of the guide rail B4-1 is frictionally connected to the outer side surface of the base 3 along the X-axis direction;

The outer side surfaces of both sides of the guide rail B4-1 are respectively processed with three threaded holes, and the threaded holes are used to adjust the first adjustment bolt 6 of the preload between the base 3 and the guide rail B4-1. The friction between the base 3 and the guide rail B4-1 can be controlled by adjusting the position of the first adjustment bolt 6, thereby playing a role in adjusting the stepping accuracy of the actuator along the X-axis linear displacement; In addition, the slider 4 and the guide rail B4-1 are integrally processed from a whole piece of elastic metal material, and the elastic metal material is 65Mn spring steel that has been quenched;

There are two guide rails A5, which are symmetrically fixed to the lower surface of the driving mechanism by four connecting bolts 8. The guide rails A5 and the lower surface of the driving mechanism constitute a second slide groove, and the upper part of the slider 4 is assembled in the second slide groove. Under the action of the guide rails A5, the actuator as a whole can output precise stepping linear displacement along the extension direction of the slider 4 (i.e., the Y axis). Three second adjusting bolts 7 are installed on the outer side of the guide rails A5. The guide rails A5 and the second adjusting bolts 7 work together, and the friction between the slider 4 and the guide rails A5 can be controlled by adjusting the position of the second adjusting bolts 7, thereby playing a role in adjusting the stepping accuracy of the actuator along the Y axis linear displacement;

The driving mechanism includes a fixed frame 1-1, a piezoelectric chip, a driving ring 1-2 and a connecting hinge 1-5; the fixed frame 1-1 is processed with 4 threaded holes around it, and the connecting bolts 8 fix the fixed frame 1-1 to the guide rail A5 through the threaded holes; the piezoelectric chip includes a piezoelectric chip A1-3, a piezoelectric chip B1-4, a piezoelectric chip C1-6, and a piezoelectric chip D1-7, wherein the piezoelectric chip A1-3 and the piezoelectric chip D1-7 are composed of a piezoelectric ceramic chip connected to an elastic sheet and the outside of the elastic sheet, and the piezoelectric chip B1-4 and the piezoelectric chip C1-6 are composed of a piezoelectric ceramic chip connected to the two sides of the elastic sheet; wherein the piezoelectric ceramic chips in the four piezoelectric chips are all glued to the elastic sheet by epoxy resin; the piezoelectric chip A1-3 and the piezoelectric chip D1-7 are connected to the fixed frame 1-1 through the connecting hinge 1-5 The piezoelectric chip B1-4 is connected to the piezoelectric chip A1-3 and the driving ring 1-2 through the connecting hinge 1-5; the piezoelectric chip C1-6 is connected to the piezoelectric chip D1-7 and the driving ring 1-2 through the connecting hinge 1-5; the piezoelectric chip A1-3 and the piezoelectric chip B1-4 are perpendicular to each other, and the piezoelectric chip C1-6 and the piezoelectric chip D1-7 are perpendicular to each other; a center hole is provided in the middle part of the driving ring 1-2, and the center hole cooperates with the movable-rotor 2 connecting shaft to realize the action output of the actuator; in order to ensure that the fixing frame 1-1, the elastic sheet in the piezoelectric chip, the connecting hinge 1-5, and the driving ring 1-2 have good deformation accuracy, the entire driving mechanism (except the piezoelectric ceramic sheet) is integrally processed from a whole piece of elastic metal material, and the elastic metal material is 65Mn spring steel that has been quenched;

The movable-rotor 2 is a disc-shaped structure. The lower surface of the movable-rotor 2 is connected to a connecting shaft with an internal thread. The upper surface of the movable-rotor 2 is processed with a threaded hole for fixing the external load. The connecting shaft is connected to the third adjusting bolt 9-1 through the center hole of the middle part of the driving ring 1-2, the elastic ring 9-3, the gasket 9-2 in sequence, wherein the diameter of the connecting shaft is slightly smaller than the diameter of the center hole of the middle part of the driving ring 1-2. The connecting shaft and the center hole of the middle part of the driving ring 1-2 are transitionally matched to ensure that the outer surface of the connecting shaft is in friction contact with the center hole of the middle part of the driving ring 1-2. The pre-tightening friction between the movable-rotor 2 and the driving ring 1-2 can be adjusted by controlling the tightening degree of the third adjusting bolt 9-1. The elastic ring 9-3 can avoid the actuator failure problem caused by the loosening of the third adjusting bolt 9-1 during the periodic operation of the actuator, provide continuous pre-tension for the connection between the movable rotor 2 and the driving ring 1-2, and further improve the reliability of the actuator operation; the external load can be fixedly mounted on the upper surface of the movable rotor 2 through the connecting piece, and the bending deformation of the piezoelectric chip in the driving mechanism under the drive of different excitation signals can be used to achieve linear displacement or rotational angular displacement output in different directions, thereby achieving linear displacement along the X-axis and Y-axis directions and rotational angular displacement around the Z-axis in the actuator plane, a total of three degrees of freedom, nanometer-level resolution and millimeter-level working stroke precision stepping motion output.

A planar three-degree-of-freedom inertial stepping piezoelectric actuator of the present invention utilizes the bending deformation of the piezoelectric chip in the driving mechanism under the excitation of the in-phase/out-of-phase sawtooth wave driving voltage, and finally realizes the precise stepping motion output with nanometer-level resolution and millimeter-level working stroke, including linear displacement in the X-axis direction and the Y-axis direction and rotational angular displacement around the Z-axis in the actuator plane, under the mutual cooperation of the base 3, the slider 4, the driving mechanism, the guide rail A5, the guide rail B4-1 and the movable-rotor 2; and each degree of freedom can be flexibly converted, and can be mutually converted between the three degrees of freedom by controlling the input form of the piezoelectric chip signal, without the problem of structural interference, and with rapid response and flexible conversion; in short, the planar three-degree-of-freedom inertial stepping piezoelectric actuator proposed by the present invention is simple, compact, small in size, highly integrated, fast in response, not subject to electromagnetic interference, flexible in conversion of each degree of freedom and convenient in control, and has good application prospects in technical fields such as aerospace, integrated circuits, optical equipment, and micro-electromechanical systems, provides a new design idea for planar three-degree-of-freedom piezoelectric actuators, and broadens the application scope of piezoelectric actuators.

The following is a detailed introduction to the working principle of a planar three-degree-of-freedom inertial stepping piezoelectric actuator that outputs precise stepping linear motion along the X-axis and Y-axis and precise stepping rotational motion around the Z-axis, in conjunction with Figures 1 to 10;

Referring to Figures 1 to 8, taking the output of precision stepping linear motion along the positive direction of the X-axis as an example, the working principle of the actuator outputting linear motion along the X-axis is introduced;

In stage (0), when the same-direction sawtooth wave signals as shown in FIG7 (a) are applied to the piezoelectric chip B1-4 and the piezoelectric chip C1-6 at the same time, the voltage applied to the piezoelectric chip B1-4 and the piezoelectric chip C1-6 in the initial state is 0, and they are in the original length state. At this time, the actuator has no motion output;

In stage (1), as the driving voltage of the piezoelectric chip B1-4 and the piezoelectric chip C1-6 is slowly increased to U, due to the inverse piezoelectric effect of the piezoelectric material, the piezoelectric chip B1-4 and the piezoelectric chip C1-6 are slowly deformed by the same magnitude along the negative direction of the X-axis. Since the driving ring 1-2 is fixedly connected to the piezoelectric chip B1-4 and the piezoelectric chip C1-6 through the connecting hinge 1-5, when the piezoelectric chip B1-4 and the piezoelectric chip C1-6 are slowly deformed by the same magnitude along the negative direction of the X-axis, the driving ring 1-2 and the movable-rotor 2 frictionally connected thereto move along the positive direction of the X-axis under the action of the force generated by the bending deformation of the piezoelectric chip B1-4 and the piezoelectric chip C1-6. Under the joint action of the piezoelectric chip B1-4 and the piezoelectric chip C1-6, the driving ring 1-2, the movable-rotor 2 and the load produce a linear displacement along the positive direction of the X-axis. During this process, due to the static friction force, the slider 4 remains stationary;

In stage (2), when the voltage signals of piezoelectric chip B1-4 and piezoelectric chip C1-6 are quickly restored to 0, piezoelectric chip B1-4 and piezoelectric chip C1-6 are quickly restored to their original lengths. Due to the effect of inertia, the dynamic-rotor 2 and the load have a tendency to maintain the "slow movement" in the positive direction of the X-axis in stage (1). However, under the action of piezoelectric chip B1-4 and piezoelectric chip C1-6, the dynamic-rotor 2 and the load move a distance of （ ＞ ), at this time, the slider 4 is driven by the piezoelectric chip B1-4 and the piezoelectric chip C1-6 to output a straight line distance of - , that is, the output accuracy of the actuator along the X-axis linear displacement is - ;

If the above process is repeated continuously, the actuator can achieve a large-stroke step linear displacement output along the positive direction of the X-axis; by applying a reverse sawtooth wave drive signal to the piezoelectric chip B1-4 and the piezoelectric chip C1-6, the actuator can achieve a large-stroke step linear displacement output along the negative direction of the X-axis.

Referring to Figures 1 to 7 and 9, taking the output of precision stepping linear motion along the positive direction of the Y-axis as an example, the working principle of the actuator outputting linear motion along the Y-axis is introduced;

In stage (0), when the piezoelectric chip A1-3 and the piezoelectric chip D1-7 are simultaneously applied with the anti-directional sawtooth wave signals shown in FIG7( b ), the voltage applied to the piezoelectric chip A1-3 and the piezoelectric chip D1-7 in the initial state is 0, and they are in the original length state, and the actuator has no motion output;

In stage (1), as the driving voltage of piezoelectric chip A1-3 slowly decreases from 0 to -U, the driving voltage of piezoelectric chip D1-7 slowly increases from 0 to U. Due to the inverse piezoelectric effect of the piezoelectric material, both piezoelectric chip A1-3 and piezoelectric chip D1-7 slowly undergo bending deformation of the same magnitude along the positive direction of the Y axis. Since the driving ring 1-2 is fixedly connected to the piezoelectric chip B1-4 and the piezoelectric chip C1-6 through the connecting hinge 1-5, and the piezoelectric chip B1-4 is connected to the piezoelectric chip A1-3 through the connecting hinge 1-5, The piezoelectric chip C1-6 is connected to the piezoelectric chip D1-7 through the connecting hinge 1-5; therefore, while the piezoelectric chip A1-3 and the piezoelectric chip D1-7 slowly undergo bending deformation of the same magnitude along the positive direction of the Y axis, the drive ring 1-2 and the movable-rotor 2 connected thereto by friction move along the positive direction of the Y axis under the action of the force generated by the bending deformation of the piezoelectric chip A1-3 and the piezoelectric chip D1-7. Under the joint action of the piezoelectric chip A1-3 and the piezoelectric chip D1-7, the drive ring 1-2 and the movable-rotor 2 produce a linear displacement in the positive direction of the Y axis. During this process, due to the static friction force, the fixed frame 1-1 in the driving mechanism and the guide rail A5 connected below the driving mechanism remain stationary;

In stage (2), when the voltage signals of piezoelectric chip A1-3 and piezoelectric chip D1-7 are quickly restored to 0, piezoelectric chip A1-3 and piezoelectric chip D1-7 are quickly restored to their original lengths. Due to the effect of inertia, the moving-rotor 2 and the load maintain the tendency of "slow movement" along the positive direction of the Y axis in stage (1). However, under the action of piezoelectric chip A1-3 and piezoelectric chip D1-7, the moving-rotor 2 and the load move a distance of （ ＞ ), at this time, driven by the piezoelectric chip A1-3 and the piezoelectric chip D1-7, the driving mechanism and the guide rail A5 connected below move as a whole along the positive direction of the Y axis by a distance of - , that is, the output accuracy of the actuator along the Y-axis linear displacement is - ;

If this process is repeated continuously, the actuator can achieve a large-stroke step linear displacement output along the positive direction of the Y-axis; by applying a reverse sawtooth wave drive signal to the piezoelectric chip A1-3 and the piezoelectric chip D1-7, the actuator can achieve a large-stroke step linear displacement output along the negative direction of the Y-axis.

Referring to FIG. 1 to FIG. 7 and FIG. 10 , taking the clockwise output precision step rotation motion around the Z axis as an example, the working principle of the actuator outputting precision step rotation motion around the Z axis is introduced;

In stage (0), when the out-of-phase sawtooth wave signals shown in FIG7 (b) are applied to the piezoelectric chips B1-4 and C1-6 at the same time, the voltage applied to the piezoelectric chips B1-4 and C1-6 in the initial state is 0, and they are in the original length state. At this time, the actuator has no motion output;

In stage (1), as the driving voltage of the piezoelectric chip B1-4 slowly increases from 0 to U, the driving voltage of the piezoelectric chip C1-6 slowly decreases from 0 to -U. Due to the inverse piezoelectric effect of the piezoelectric material, the piezoelectric chip B1-4 slowly bends and deforms along the negative direction of the X-axis, and the piezoelectric chip C1-6 slowly bends and deforms along the positive direction of the X-axis to the same extent as the piezoelectric chip B1-4. Since one end of the piezoelectric chip B1-4 and the piezoelectric chip C1-6 are connected to the driving ring 1-2 through the connecting hinge 1-5, the driving ring 1-2 rotates clockwise around the Z axis due to the torque of the connecting hinges 1-5 on both sides. Under the action of static friction, the moving rotor 2 rotates clockwise around the Z axis along with the driving ring 1-2. ;

In stage (2), when the driving voltage of the piezoelectric chip B1-4 drops rapidly from U to 0 and the driving voltage of the piezoelectric chip C1-6 rises rapidly from -U to 0, the piezoelectric chip B1-4 and the piezoelectric chip C1-6 quickly return to their initial state, thereby driving the connected connecting hinge 1-5 and the driving ring 1-2 to quickly return to their initial positions. The moving-rotor 2 and the load rotate counterclockwise by an angle under the combined action of inertia and the friction force of the inner wall of the center hole in the middle part of the driving ring 1-2. （ ＞ ), driven by a sawtooth waveform electrical signal, the moving-rotor 2 and the load produce a clockwise angular displacement relative to the driving ring 1-2 - , that is, the output accuracy of the actuator's angular displacement around the Z axis is - ;

If this process is repeated continuously, the actuator can achieve a large-stroke step rotation displacement output clockwise around the Z axis; by applying a reverse sawtooth wave drive signal to the piezoelectric chip B1-4 and the piezoelectric chip C1-6, the actuator can achieve a large-stroke step rotation displacement output counterclockwise around the Z axis.

The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims (7)

1. A plane three-degree-of-freedom inertial stepping piezoelectric actuator is characterized in that: comprises a base (3), a sliding block (4), a guide rail A (5), a guide rail B (4-1), a driving mechanism and a moving-rotor (2);

A round hole is formed in the center of the base (3);

The lower surface of the sliding block (4) is symmetrically and integrally provided with a guide rail B (4-1), the guide rail B (4-1) and the lower surface of the sliding block (4) form a first chute, the lower surface of the sliding block (4) is in friction connection with the upper surface of the base (3), and the inner side surface of the guide rail B (4-1) is in friction connection with the outer side surface of the base (3) along the X-axis direction;

the number of the guide rails A (5) is two, the guide rails A (5) are symmetrically fixed on the lower surface of the driving mechanism, the guide rails A (5) and the lower surface of the driving mechanism form a second chute, and the upper part of the sliding block (4) is assembled in the second chute;

The driving mechanism comprises a fixed frame (1-1), a piezoelectric wafer, a driving ring (1-2) and a connecting hinge (1-5); the fixed frame (1-1) is fixedly connected with the guide rail A (5); the piezoelectric wafer comprises a piezoelectric wafer A (1-3), a piezoelectric wafer B (1-4), a piezoelectric wafer C (1-6) and a piezoelectric wafer D (1-7), wherein the piezoelectric wafer A (1-3) and the piezoelectric wafer D (1-7) are connected with the fixed frame (1-1) through a connecting hinge (1-5), and the piezoelectric wafer B (1-4) is connected with the piezoelectric wafer A (1-3) and the driving ring (1-2) through the connecting hinge (1-5); the piezoelectric wafer C (1-6) is connected with the piezoelectric wafer D (1-7) and the driving ring (1-2) through the connecting hinge (1-5); the piezoelectric wafer A (1-3) is perpendicular to the piezoelectric wafer B (1-4), and the piezoelectric wafer C (1-6) is perpendicular to the piezoelectric wafer D (1-7); the driving ring (1-2) is coaxially and fixedly connected with the moving-rotor (2);

The bending deformation of the piezoelectric wafer in the driving mechanism driven by different excitation signals is utilized to realize the linear displacement or rotation angular displacement output in different directions, so as to realize the precise stepping motion output of three degrees of freedom in total of the linear displacement in the X-axis direction and the Y-axis direction and the rotation angular displacement around the Z-axis in the plane of the actuator;

The movable rotor (2) is of a disc-shaped structure, the lower surface of the movable rotor (2) is connected with a connecting shaft with internal threads, the connecting shaft is connected with a third adjusting bolt (9-1) sequentially through a central hole of the middle part of the driving ring (1-2), an elastic ring (9-3) and a gasket (9-2), the diameter of the connecting shaft is smaller than that of the central hole of the middle part of the driving ring (1-2), the connecting shaft is in transition fit with the central hole of the middle part of the driving ring (1-2), friction contact between the outer surface of the connecting shaft and the central hole of the middle part of the driving ring (1-2) is guaranteed, and the aim of adjusting the pretightening friction force between the movable rotor (2) and the driving ring (1-2) is achieved by controlling the screwing degree of the third adjusting bolt (9-1).

2. A planar three degree of freedom inertial stepper piezoelectric actuator according to claim 1, wherein: 4 threaded holes are further formed in the periphery of the base (3), and the base (3) is fixedly connected with the workbench through the connecting piece.

3. A planar three degree of freedom inertial stepper piezoelectric actuator according to claim 1, wherein: the outer side surfaces of the two sides of the guide rail B (4-1) are respectively provided with 3 threaded holes, the threaded holes are used for controlling friction force between the base (3) and the guide rail B (4-1) by adjusting a first adjusting bolt (6) for pre-tightening force between the base (3) and the guide rail B (4-1) and further playing a role in adjusting stepping precision of linear displacement of the actuator along the X axis.

4. A planar three degree of freedom inertial stepper piezoelectric actuator according to claim 3, wherein: the sliding block (4) and the guide rail B (4-1) are processed by a whole piece of quenched 65Mn spring steel.

5. A planar three degree of freedom inertial stepper piezoelectric actuator according to claim 1, wherein: 3 second adjusting bolts (7) are respectively installed on the outer side face of the guide rail A (5), the guide rail A (5) and the second adjusting bolts (7) are matched to work, the friction force between the sliding block (4) and the guide rail A (5) is controlled by adjusting the position of the second adjusting bolts (7), and then the function of adjusting the linear displacement stepping precision of the actuator along the Y axis is achieved.

6. A planar three degree of freedom inertial stepper piezoelectric actuator according to claim 1, wherein: the piezoelectric wafers A (1-3) and D (1-7) are composed of elastic sheets and piezoelectric ceramic sheets connected with the outer sides of the elastic sheets, and the piezoelectric wafers B (1-4) and C (1-6) are composed of elastic sheets and piezoelectric ceramic sheets connected with the two sides of the elastic sheets.

7. A planar three degree of freedom inertial stepper piezoelectric actuator according to claim 1, wherein: the fixed frame (1-1), the elastic sheet in the piezoelectric wafer, the connecting hinge (1-5) and the driving ring (1-2) are processed by a whole piece of quenched 65Mn spring steel.