CN103281005B - A kind of macro and micro servo type linear piezoelectric motor and driving method thereof - Google Patents

Abstract

The invention discloses a macro-micro-driven linear piezoelectric motor and a driving method thereof, and relates to the field of ultrasonic motors and micro-drives. The motor includes a frame, a drive vibrator, a mover and a pretension mechanism. The driving vibrator includes a metal elastic body, a micro-displacement amplifying elastic body and a piezoelectric element. Two symmetrical convex teeth inside the micro-displacement amplifying elastic body are in frictional contact with the mover, and the piezoelectric element is polarized along the thickness direction. The motor macro drive method is that the vibrator excites two near-frequency, same-shaped, and 90-degree longitudinal standing waves with a phase difference of 90 degrees under the action of an alternating current with a phase difference of 90 degrees. After synthesis, an elliptical motion trajectory is formed at the convex tooth. Under the action of pretightening force, the mover can produce macro linear motion. The micro-drive method is to apply a DC high voltage to the piezoelectric element to cause static deformation of the vibrator, and to amplify the micro-displacement by two symmetrical convex teeth inside the elastic body to clamp the mover to produce a micro-linear motion. The invention can simultaneously realize macro and micro drives on one motor, and has the characteristics of simple structure, reliable operation and the like.

Description

A macro-micro-driven linear piezoelectric motor and its driving method

technical field

The invention relates to the field of motor research, in particular to a macro-micro-driven linear piezoelectric motor and a driving method thereof.

Background technique

With the rapid progress of the IC manufacturing process and the urgent demand for tiny chips in the market, the chip integration level is increasing day by day, the I/O density is getting higher and higher, the chip size, chip lead spacing and pad diameter continue to decrease, and the chip packaging industry The rapid development puts forward extremely high requirements on the positioning accuracy, motion speed and acceleration of packaging equipment. However, the improvement of positioning accuracy and movement speed is contradictory. The increase of movement speed and acceleration will increase the inertial force of the mechanism, and the frequency of inertial force changes will also increase. The system is prone to elastic deformation and vibration, which will damage the mechanism. The accuracy of motion increases the establishment time of mechanical stability, affects the fatigue strength of components, and aggravates the wear and tear in the kinematic pair. High-precision positioning requires smooth movement of the mechanism, while high productivity requires high-speed reciprocating motion and high-speed start and stop of the system, that is, large stroke and high precision are contradictory. How to better resolve these contradictions and realize the precise positioning of large-stroke and high-speed mechanical motion systems has become an urgent problem in the current chip packaging industry.

Due to its small size, high displacement resolution, fast response speed, large output force, and high energy conversion efficiency, the piezoelectric ceramic drive has become an ideal drive element for precise positioning, but its stroke is only tens of microns, so its application range restricted.

At present, there is a concept of macro-micro drive in the prior art, that is, a single motor can realize large-stroke high-speed movement and high-resolution precision movement at the same time, but this concept cannot be accurately realized in practical applications.

Contents of the invention

The main purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and provide a macro-micro-driven linear piezoelectric motor, which is simple in structure, compact and reliable in operation. Ultrasonic drive in vibration mode of the vibrator can be realized under the difference, and micro-drive (creep) of static deformation can also be realized through the micro-displacement amplification mechanism. On the same motor, large-stroke high-speed movement and high-resolution low-speed movement can be realized, which is the so-called macro and micro drivers.

Another object of the present invention is to provide a driving method based on the above-mentioned macro-micro-driven linear piezoelectric motor.

The purpose of the present invention is achieved through the following technical solutions: a macro-micro-driven linear piezoelectric motor, including a frame, a driving vibrator, a mover, and a device for locking the frame, driving the vibrator, and the mover, and adjusting the pretightening force Pre-tightening mechanism, bearings are provided at both ends of the frame, and the mover passes through the two bearings and the driving vibrator; the driving vibrator includes piezoelectric elements, two metal elastic bodies with holes in the middle and a micro-displacement with holes in the middle Enlarging the elastic body, two metal elastic bodies are respectively connected with the two ends of the micro-displacement amplifying elastic body, and the inner middle of the hole of the micro-displacement amplifying elastic body is provided with a convex tooth, and the convex tooth is connected with the mover in friction contact during the driving process, and the micro-displacement is enlarged Both ends of the elastic body are provided with grooves for placing piezoelectric elements, and 2M piezoelectric ceramic discs are placed at each end, M≥1, each piezoelectric ceramic disc is polarized along the thickness direction, and every two piezoelectric ceramic discs are polarized They are opposite in nature and attached to each other into a group, and the groups are placed symmetrically in the grooves on both ends of the micro-displacement amplifying elastic body. Both sides of each piezoelectric ceramic disc are provided with metal sheets as terminals. The piezoelectric ceramic discs of each group are The ceramic contact surface, that is, the common contact area within the group is the power signal input terminal, and the non-common contact area of piezoelectric ceramics in each group is the power signal input ground terminal. The core component of the piezoelectric motor of the present invention is a composite driving vibrator, which is composed of two metal elastic bodies connected in series through micro-displacement amplifying elastic bodies. Excite two near-frequency, same-type standing waves of longitudinal vibration with a phase difference of 90 degrees. After the two standing waves are synthesized, an elliptical motion trajectory is formed at the convex tooth. By adjusting the pre-tightening force between the drive vibrator and the mover , and then the mover can generate the required linear motion by means of friction transmission under the action of the pre-tightening force. In this way, the mover can move at a high speed with a large stroke, and at the same time, under the action of the piezoelectric element, it can also realize a precise movement with a small stroke, which is the so-called macro-micro drive.

Preferably, the piezoelectric ceramic disc is a piezoelectric ceramic disc or a regular polygonal piezoelectric ceramic disc.

Preferably, the protruding teeth provided in the inner middle of the micro-displacement amplifying elastic body hole are vertically symmetrical V-shaped protruding teeth, or parabolic protruding teeth, or arc-shaped protruding teeth.

As a preferred solution, both the metal elastic body and the micro-displacement amplifying elastic body are provided with bosses, in order to prevent the vibration of the micro-displacement amplifying elastic body from causing radial displacement between the micro-displacement amplifying elastic body and the connecting terminal through friction, the bosses There are holes inside, and the metal elastic body and the micro-displacement amplifying elastic body are connected by fastening bolts. During assembly, the metal elastic body and the micro-displacement amplifying elastic body can be tightly connected together by adjusting the fastening bolts, and this structure is suitable for bearing higher excitation voltage.

As another preferred solution, the outer surface of the metal elastic body is a prism structure, and at the same time, an external thread is provided on the outer surface, and an internal thread is provided on the micro-displacement amplifying elastic body. The notch of the body, the metal elastic body and the micro-displacement amplifying elastic body are connected by screw fit. This structure is suitable for small thrust applications. In practical applications, hexagonal, pentagonal, and quadrangular prisms can be selected for the outer surface of the metal elastomer, or even only two planes can be cut on the surface, which can be used as wrench positions, which is convenient for the wrench to adjust the tightness.

As another preferred solution, the outer surface of the metal elastic body is a prism structure, and the inner surface is provided with internal threads, and the micro-displacement amplifying elastic body is provided with external threads, and the two are connected by thread fit. Holes for leading wires to be drawn out are provided at the positions. This structure not only facilitates the staff to adjust the tightness between the micro-displacement amplifying elastic body and the metal elastic body, but also improves the performance of the piezoelectric motor.

Furthermore, in the above three types of fixing structures, the micro-displacement amplifying elastic body is hollow, a combination of special-shaped cylinders and cylinders or a combination of cones and cylinders or a combination of pyramids and prisms.

As a preference, when the micro-displacement amplifying elastic body and the metal elastic body are connected by thread fit, in order to facilitate the assembly of the driving vibrator and compress the piezoelectric element, the micro-displacement amplifying elastic body in the driving vibrator is symmetrically cut out along the axial direction The two planes parallel to the axis are the wrench positions.

Preferably, a rubber gasket is further arranged between the metal elastic body and the micro-displacement amplifying elastic body. Through the elastic deformation of the rubber washer, it not only plays the role of adjusting the pre-tightening force, but also plays the role of vibration isolation.

Preferably, the mover is a cylindrical guide rod or a prismatic guide rod.

Preferably, the material of the metal sheet serving as the connection terminal is red copper.

Preferably, the bearings provided at both ends of the frame are rolling linear ball bearings or sliding bearings. The use of these two types of bearings can limit the radial displacement of the mover and make the mover move in a straight line in the axial direction.

A driving method based on the above-mentioned macro-micro-driven linear piezoelectric motor, the motor includes a mover and a driving vibrator, the driving method includes macro-driving and micro-driving, macro-driving refers to: according to the position of the piezoelectric element in the driving vibrator, Under the action of alternating current with a phase difference of 90 degrees, the driving vibrator respectively excites two near-frequency, identical-type standing waves of longitudinal vibration with a phase difference of 90 degrees. After the two standing waves are combined, an elliptical micron is formed at the convex tooth Under the action of the pre-tightening force generated by the pre-tightening mechanism, the convex teeth rely on the friction with the mover to make the mover perform a high-speed linear motion with a large stroke; micro-drive refers to: applying DC high voltage excitation to the piezoelectric element , so that the vibrator produces static deformation along the axis of the cylinder, and then the two upper and lower convex teeth on the inner side of the elastic body are used to clamp the mover to produce a precise linear motion with a small stroke through micro-displacement amplification.

The working principle of the macro-drive of the present invention is as follows: the driving vibrator of the present invention is excited by ultrasonic waves, and the symmetrical vibration mode and the anti-symmetrical vibration mode of the two longitudinal vibrations are selected. When the left and right piezoelectric ceramic discs are fed with the same phase voltage excitation signal at the same time, the left and right vibrators are stretched and compressed at the same time, providing a radial tension force for the contact area between the convex teeth and the mover, so that the vibrator has a radial displacement. , the symmetrical longitudinal vibration form is called the symmetrical vibration mode; when the left and right piezoelectric ceramics are simultaneously fed with opposite voltage excitation signals, the left and right vibrators stretch while compressing, providing intermittent vibration for the contact area between the convex teeth and the mover. The force in the axial direction that can change the direction can cause the vibrator to displace in the axial direction, and the axial displacement direction can be changed by changing the voltage signal. This asymmetric longitudinal vibration form is called antisymmetric vibration mode. The displacement in two directions forms an elliptical trajectory in the contact area between the convex teeth and the mover, thereby driving the mover to move in a straight line. Through the finite element simulation calculation and design of the size of each part of the driving vibrator, the resonant frequencies of the above two vibration modes tend to be consistent, so that the two modes can be excited with the same frequency.

The working principle of the micro-drive of the present invention is as follows: when the piezoelectric element driving the vibrator of the present invention is excited by a DC high voltage, it will produce nano-scale micro-deformation along the axial direction. The protruding teeth in the drive vibrator transmit the deformation to the mover through friction. The direction of the micro-deformation of the driving vibrator can be changed by different wiring. Through theoretical calculation, it can be known that the deformation amount has a linear relationship with the voltage.

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

1. The present invention proposes to add a driving vibrator on the basis of the linear piezoelectric motor. The driving vibrator is composed of a piezoelectric element, two metal elastic bodies and a micro-displacement amplifying elastic body. By applying direct current to the piezoelectric element High voltage can drive the mover to do high-resolution and low-speed movement, and the motor itself can move at a high speed with a large stroke, so macro and micro drives are realized.

2. The piezoelectric element in the present invention only needs to be polarized along the axial direction, without in-plane partitioning, which greatly simplifies the processing technology of the piezoelectric element.

3. The structure of the motor stator of the present invention is simple and compact. The piezoelectric element and the metal elastic body do not need to be bonded, and the metal elastic body and the micro-displacement amplifying elastic body can be fastened. The processing is simple, easy for industrial production, and low in cost.

4. The present invention provides three kinds of fastening methods for the metal elastic body and the micro-displacement amplifying elastic body. In practical applications, different fastening methods can be used for piezoelectric ceramic discs according to different applications to obtain an appropriate pre-tightening pressure , a wide range of applications.

5. The method of the present invention is to excite the vibrator respectively under the action of an alternating current with a phase difference of 90 degrees, two near-frequency, same-type standing waves of longitudinal vibration with a phase difference of 90 degrees, wherein two vibration modes are involved, Changing the size and length of the metal elastic body and micro-displacement amplifying the elastic body makes the two resonance frequencies coordinate, which brings great convenience to the design and debugging of the motor.

Description of drawings

Fig. 1 is the main sectional view of the device of embodiment 1 of the present invention;

Fig. 2 is a main sectional view of the driving vibrator in Embodiment 1 of the present invention;

Fig. 3 is A-A sectional view in Fig. 2;

Fig. 4 is a top view of the driving vibrator in Embodiment 1 of the present invention;

5 is a schematic diagram of the working principle state of the driving vibrator in Embodiment 1 of the present invention;

Fig. 6 is a main sectional view of the driving vibrator in Embodiment 2 of the present invention;

Fig. 7 is a sectional view of section A-A in Fig. 6;

Fig. 8 is a top view of the driving vibrator in Embodiment 2 of the present invention;

Fig. 9 is a main sectional view of the driving vibrator in Embodiment 3 of the present invention;

Fig. 10 is a cross-sectional view of A-A in Fig. 9;

Fig. 11 is a top view of the driving vibrator in Embodiment 3 of the present invention.

Among them: 1—mover; 2—fastening bolt; 3—retaining ring; 4—rolling linear ball bearing; 5—metal elastic body; 6—piezoelectric element; 7—micro displacement amplifying elastic body; 8—terminal ; 9—rubber washer; 10—frame cover; 11—frame plate; 12—convex tooth; 13—flat washer; 14—cylindrical spring; 15—fastening nut.

detailed description

The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example 1

As shown in Figure 1, a macro-micro-driven linear piezoelectric motor includes a frame, a driving vibrator, a mover 1, and a pretension mechanism for locking the frame, driving the vibrator, and the mover 1 and adjusting the preload , In this embodiment, the frame includes a frame plate 11, a frame cover 10, and the pre-tightening mechanism includes a fastening bolt 2, a rubber washer 9, a flat washer 13, a cylindrical spring 14 and a fastening nut 15, etc. The pre-tightening mechanism gives a certain pre-tightening force to the motor stator by changing the feeding depth of the fastening bolt 2 and the elastic deformation of the rubber washer 9 . Rolling linear ball bearings 4 are provided at both ends of the frame, and a circlip 3 is provided between the bearing 4 and the frame cover 10. The mover 1 is a constant-radius cylindrical guide rod, and the mover 1 passes through the two bearings and the drive vibrator. The hole in the middle is guided by rolling linear ball bearings on both sides to make the mover 1 move axially and linearly. At the same time, the frame plate 11 and the frame cover 10 surround the two cylindrical conjoined vibrators, so as to prevent the performance of the motor from being affected by dust and water vapor in the air and damp.

The drive vibrator in this embodiment is shown in Figures 2, 3, and 4. The drive vibrator includes a piezoelectric element 6, two metal elastic bodies 5 with holes in the middle, and a micro-displacement amplifying elastic body 7 with holes in the middle. The middle part of the inner side of the displacement amplification elastic body 7 is provided with a convex tooth 12, and the convex tooth 12 is in frictional contact with the mover 1 during the driving process, and the contact area between the two is the driving area. Grooves for electrical components. The piezoelectric element 6 in this embodiment is a piezoelectric ceramic disk. When in use, each piezoelectric ceramic disk is polarized along the thickness direction, and every two piezoelectric ceramic disks have opposite polarities and are attached to each other to form a group, which is symmetrical Placed in the grooves on both ends of the micro-displacement amplifying elastic body, the number of groups of piezoelectric ceramic discs at both ends is equal, and each piezoelectric ceramic disc is provided with a metal sheet 8 as a terminal on both sides, and the metal sheet adopts Copper material. The piezoelectric ceramic contact surface of each group, that is, the common contact area within the group is the power signal input end, and the piezoelectric ceramic non-common contact area of each group is the power signal input ground end.

In practical applications, the protruding teeth 12 provided in the inner middle of the micro-displacement amplifying elastic body hole 7 can be vertically symmetrical V-shaped protruding teeth, or parabolic protruding teeth, or arc-shaped protruding teeth. In this embodiment, What adopted is arc-shaped convex tooth. The two sides of the micro-displacement amplifying elastic inner hole are hollow cylinders with variable diameters. At the same time, in order to facilitate the assembly of the drive vibrator, the micro-displacement amplifying elastic body is cut along the axis direction, and two planes parallel to the axis are symmetrically cut out as wrench positions. In the application, the metal elastomer can also be cut according to the need.

It can be seen from Figures 2 and 4 that the inner surface of the metal elastic body in the driving vibrator is provided with internal threads, and the micro-displacement amplifying elastic body is provided with external threads. A hole for the lead wire to exit.

The installation process of the motor described in this embodiment is as follows: first install the drive vibrator, firstly clamp the terminal 8 and the piezoelectric ceramic disc 6 in the groove of the micro-displacement amplifying elastic body 7, and connect the wiring leads from the metal elastic body 5 The internal and external threads are fastened after being drawn out from the lead wire hole, and the micro-displacement amplifying elastic body 7 and the metal elastic body 5 are fastened. After installation, pass the mover 1 through the middle of the drive vibrator, check whether it is installed correctly, prevent the radial deviation of the parts, confirm that there is no interference with the mover 1, take out the mover 1 after it is correct, and the installation of the vibrator is completed.

Carry out complete machine installation then, first rolling linear ball bearing 4 is packed in the frame cover 10, then motor end cover and frame cover 10 are connected together with fastening bolt 2, prevent bearing axially from slipping out. Install the frame cover 10, rubber washer 9, and drive vibrator sequentially from left to right, the rubber washer 9, frame plate 11 from the four sides, and then the right frame cover, fasten bolts 2 to connect the left and right frame covers, move Child 1 passes through the middle of bearing 4, and the whole machine is installed. Apply a certain preload and the external power supply is ready to work.

The driving method of this embodiment based on the above-mentioned macro-micro drive linear piezoelectric motor is: the drive vibrator respectively excites two near-frequency, same-type longitudinal vibrations with a phase difference of 90 degrees under the action of an alternating current with a phase difference of 90 degrees. Standing wave, after the two standing waves are synthesized, an elliptical motion trajectory is formed at the convex tooth. Under the action of the pre-tightening force generated by the pre-tightening mechanism, the convex tooth drives the mover to move in a straight line by the friction with the mover.

In specific practical applications, the number and thickness of piezoelectric ceramic discs can be determined according to requirements. For example, as shown in Fig. Two pieces form a group, each on the left and right. A thin copper sheet is added between the piezoelectric ceramic discs as the ultrasonic excitation signal terminal. Between discs ③ and ④ are terminals for connecting Ucosωt excitation signals, and the rest are grounding terminals.

The working process of eight piezoelectric elements and the states of the piezoelectric elements in each process will be described in detail below through Fig. 5 .

Since the upper driving point (shown in Fig. 5(m)) and the lower driving point (shown in Fig. 5(n)) are symmetrical, the above driving point m is used as the description object of the following principle. Figure (A) is the displacement of the symmetric mode, Usinωt is applied to the left and right branches of the driving oscillator, Figure (B) is the displacement of the asymmetric mode, the left branch of the driving oscillator is applied to -Ucosωt, and the right branch is applied to Ucosωt, Figure ( C) The total displacement when Usinωt is applied to the left branch of the driving vibrator and Ucosωt is applied to the right branch. L ₄ =L _y ~0, L ₈ =0 ~ -2L _x and L _y represent the maximum displacement in the transverse direction and the longitudinal direction, respectively.

(1) When ωt=0～π/2, L ₁ =0～-L _y , L ₅ =-L _x ～0, the displacement change of the driving vibrator is shown in Figure 5 (a-1), (a-2) , (a-3) shown. The stator gradually changes from the maximum compression position of the left branch in the asymmetric mode and the maximum elongation displacement of the right branch to the maximum longitudinal compression position in the symmetric mode (shown in (a-1) in Figure 5). The driving end face of the stator rotates counterclockwise from the leftmost end of the anti-symmetric mode to the bottom end of the symmetrical mode (shown in (a-3) in Figure 5). Under the action of the preload, the driving mover moves to the right a distance of L _x .

(2) When ωt=π/2～π, L ₂ =-L _y ～0, L ₆ =0～L _x , the displacement of the driving vibrator changes as shown in (b-1) and (b-2) in Figure 5 ( b-3). The stator gradually changes from the maximum compression position of the symmetric mode to the maximum elongation of the left branch and the maximum compression position of the right branch of the anti-symmetric mode (shown in (b-2) in Figure 5). The driving end face of the stator rotates counterclockwise from the bottom end of the symmetric mode to the right end of the anti-symmetry (shown in (b-3) in Figure 5). Under the action of prestress, the driving mover moves to the right by a distance of L _x .

(3) When ωt=π～3π/2, L ₃ =0～L _y , L ₇ =L _x ～0, the displacement changes of the driving vibrator are shown in Figure 5 (c-1), (c-2), ( c-3). The stator gradually changes from the maximum elongation of the left branch and the maximum compression of the right branch in the antisymmetric mode to the maximum elongation position of the symmetric mode (shown in (c-1) in Figure 5). The driving end face of the stator rotates counterclockwise from the antisymmetric rightmost end to the symmetrical uppermost end (shown in (c-3) in Figure 5). Since the driving end face is separated from the mover at this time, there is no driving effect on the mover.

(4) When ωt=3π/2～2π, L ₄ =L _y ～0, L ₈ =0～-L _x , the displacement changes of the driving vibrator are shown in Figure 5 (d-1), (d-2), (d-3) shown. The stator gradually changes from the maximum elongation position of the symmetric mode to the maximum compression position of the left branch and the maximum elongation position of the right branch of the anti-symmetric mode (shown in (d-2) in Figure 5). The driving end face of the stator rotates counterclockwise from the symmetrical uppermost end to the asymmetrical leftmost end (shown in (d-3) in Figure 5). Since the driving end face is separated from the mover at this time, there is no driving effect on the mover.

To sum up, the upper driving end surface of the motor completes a circle counterclockwise along an elliptical trajectory in one cycle. Similarly, the lower driving end surface completes a circle clockwise along an elliptical trajectory in one cycle, and the upper and lower driving end surfaces Simultaneously, the mover is driven to move the displacement of 2Lx to the right in total, and the mover moves far to the right when it goes round and round like this. If the voltage signal is switched on the two branches of the driving vibrator, the rotation direction of the elliptical motion track of the motor driving end surface will be correspondingly reversed, which is manifested as the reverse of the mover.

Example 2

This embodiment has the same structure as Embodiment 1 except for the following features: the drive vibrator of this embodiment is shown in Figures 6, 7, and 8, and the metal elastic body 25 at each end of the drive vibrator is divided into two parts, which are close to the frame cover The outer surface of one end is a hexagonal prism structure, which can be used as a wrench position when fixing. The outer surface of the end connected with the micro-displacement amplifying elastic body is a cylinder, and the outer surface is provided with external threads, and the micro-displacement amplifies the elasticity. The body 27 is provided with an internal thread, and the internal thread is provided with a notch for leading the lead wire to amplify the micro-displacement of the elastic body, and the connecting terminal 28 is drawn out from this notch. The piezoelectric ceramic disc 26, the metal elastic body 25 and the micro-displacement amplifying elastic body 27 are fastened together by internal and external threads. This structure is suitable for small thrust applications. A protruding tooth 212 is provided in the inner middle of the micro-displacement amplifying elastic body hole 27, and the protruding tooth 212 is in frictional contact with the mover during the driving process, and the contact area between the two is the driving area.

The installation process of the driving vibrator in this embodiment is as follows: the connecting terminal 28 and the piezoelectric ceramic disc 26 are stuck in the groove of the micro-displacement amplifying elastic body 27 in sequence, and the lead wire of the connecting terminal 28 is set aside from the reserved position of the micro-displacement amplifying elastic body 27. lead out in the gap, and then the metal elastic body 25 is screwed into the internal thread of the micro-displacement amplifying elastic body 27, and the metal elastic body 25 is tightened with a wrench. After installation, pass the mover through the middle of the drive vibrator, check whether it is installed correctly, prevent the radial deviation of the parts, confirm that there is no interference with the mover, take out the mover after it is correct, and the installation of the vibrator is completed.

Example 3

The structure of this embodiment is the same as that of Embodiment 2 except for the following features: the driving vibrator of this embodiment is shown in Figures 9, 10, and 11. The outer surface of the metal elastic body 35 in the driving vibrator is a cylinder, and the metal elastic body 35 Bosses are arranged on the outer side of the micro-displacement amplifying elastic body 37, and the two are connected by fastening bolts 33 and fastening nuts 34. In practical applications, in order to facilitate the connection of bolts, the micro-displacement amplifying elastic body and the metal elastic body can be designed as variable-diameter cylinders as required. A convex tooth 312 is provided in the inner middle of the micro-displacement amplifying elastic body hole 37, and the convex tooth 312 is in frictional contact with the mover during the driving process, and the contact area between the two is the driving area.

The installation process of the driving vibrator in this embodiment is as follows: firstly, the connecting terminal 38 and the piezoelectric ceramic disk 36 are stuck in the groove of the micro-displacement amplifying elastic body 37 in sequence, and then the metal elastic body 35 is placed on the micro-displacement amplifying elastic body On both sides of 37, the fastening bolt 33 is passed through the bolt hole of the micro-displacement amplifying elastic body, and the micro-displacement amplifying elastic body and the metal elastic body are fastened. After installation, pass the mover through the middle of the drive vibrator, check whether it is installed correctly, prevent the radial deviation of the parts, confirm that there is no interference with the mover, take out the mover after it is correct, and the installation of the vibrator is completed.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (10)

1. A macro-micro-driven linear piezoelectric motor is characterized in that it comprises a frame, a drive vibrator, a mover, and a preloading mechanism for locking the frame, driving a vibrator, a mover and adjusting a preload, so Bearings are provided at both ends of the frame, and the mover passes through the two bearings and the driving vibrator; the driving vibrator includes a piezoelectric element, two metal elastic bodies with holes in the middle, and a micro-displacement amplifying elastic body with holes in the middle. Two metal elastic bodies are respectively connected with the two ends of the micro-displacement amplifying elastic body. The inner middle of the hole of the micro-displacement amplifying elastic body is provided with protruding teeth. There are grooves for placing piezoelectric elements, 2M piezoelectric ceramic discs are placed at each end, M≥1, each piezoelectric ceramic disc is polarized along the thickness direction, and every two piezoelectric ceramic discs have opposite polarities and are attached to each other to form a One group is symmetrically placed in the grooves on the two ends of the micro-displacement amplifying elastic body. Both sides of each piezoelectric ceramic disc are provided with metal sheets as terminals. The contact surface of each group of piezoelectric ceramics is the group The inner common contact area is the power signal input end, and the non-common contact area of piezoelectric ceramics in each group is the power signal input ground end. 2. The macro-micro driven linear piezoelectric motor according to claim 1, characterized in that bosses are provided on the outside of the metal elastic body and the micro-displacement amplifying elastic body, holes are arranged in the boss, and the metal elastic body Connect with micro-displacement amplifying elastic body by fastening bolts. 3. The macro-micro-driven linear piezoelectric motor according to claim 1, wherein the outer surface of the metal elastic body is a prism structure, and an external thread is arranged on the outer surface, and an inner thread is arranged on the micro-displacement amplifying elastic body. The internal thread is provided with a notch for leading the lead wire out of the micro-displacement amplifying elastic body, and the metal elastic body and the micro-displacement amplifying elastic body are connected through thread fit. 4. The macro-micro-driven linear piezoelectric motor according to claim 1, characterized in that, the outer surface of the metal elastic body is a prism structure, and the inner surface is provided with internal threads, and the micro-displacement amplifying elastic body is provided with external threads. The thread, the two are connected by thread fitting, and a hole for leading the lead wire is provided at the non-threaded position of the metal elastic body. 5. The macro-micro-driven linear piezoelectric motor according to any one of claims 3 and 4, characterized in that, the micro-displacement amplifying elastic body in the driving vibrator symmetrically cuts out two planes parallel to the axis along the axis direction for the wrench. 6. The macro-micro-driven linear piezoelectric motor according to claim 1, characterized in that: The micro-displacement amplifying elastic body is hollow, a combination of special-shaped cylinders and cylinders or a combination of cones and cylinders or a combination of pyramids and prisms; The piezoelectric ceramic disc is a piezoelectric ceramic disc or a regular polygonal piezoelectric ceramic disc. 7. The macro-micro-driven linear piezoelectric motor according to claim 1, characterized in that: the convex teeth provided in the middle of the micro-displacement amplifying elastic body hole are vertically symmetrical V-shaped convex teeth, or parabolic convex teeth. teeth, or arc-shaped convex teeth. 8. The macro-micro-driven linear piezoelectric motor according to claim 1, characterized in that: a rubber gasket is also arranged between the metal elastic body and the micro-displacement amplifying elastic body. 9. The macro-micro-driven linear piezoelectric motor according to claim 1, characterized in that: The mover is a cylindrical guide rod or a prismatic guide rod; The bearings arranged at both ends of the frame are rolling linear ball bearings or sliding bearings. 10. A driving method based on the macro-micro-driven linear piezoelectric motor according to claim 1, wherein the motor includes a mover and a driving vibrator, and the driving method includes macro-drive and micro-drive, Macro drive refers to: According to the position of the piezoelectric element in the driving vibrator, the driving vibrator respectively excites two near-frequency, same-type, standing waves of longitudinal vibration with a phase difference of 90 degrees under the action of an alternating current with a phase difference of 90 degrees. , after the two standing waves are synthesized, an elliptical micron-scale motion trajectory is formed at the convex tooth. Under the action of the pre-tightening force generated by the pre-tightening mechanism, the convex tooth relies on the friction with the mover to make the mover perform a high-speed linear motion with a large stroke. ; Micro-drive refers to: apply DC high-voltage excitation to the piezoelectric element, so that the vibrator produces static deformation along the axis of the cylinder, and then enlarges the upper and lower convex teeth inside the elastic body through micro-displacement to clamp the mover to produce a precise straight line with a small stroke. sports.