CN105932900B - A kind of biped driving off-resonance piezoelectric linear motor based on lever amplification - Google Patents

Abstract

The invention discloses a biped-driven non-resonant piezoelectric linear motor based on lever amplification, which comprises a stator assembly, a linear guide rail, a pre-tightening device, a stator fixing plate and a bottom plate; the stator assembly is fixedly connected to the stator fixing plate, and the stator The front end of the assembly is equipped with a mover guide rail, and the rear end is connected to a preload device; there is a preload spring in the preload device, and the front end of the stator assembly is kept in contact with the mover guide rail under the pressure generated by the deformation of the preload spring; the mover The guide rail, the pre-tensioning device and the pre-tensioning device are all installed on the base. The stator assembly is composed of a stator structure, laminated piezoelectric ceramics, pads, and pre-tightening screws. The structure of the motor is simple, the volume is small and exquisite, and it is easy to install. The linear motion of the piezoelectric motor can be realized by applying certain electrical signals to the four groups of laminated piezoelectric ceramics respectively.

Description

A Biped Driven Non-resonant Piezoelectric Linear Motor Based on Lever Amplification

technical field

The invention belongs to the technical field of piezoelectric precision braking applications, in particular to a biped-driven non-resonant piezoelectric linear motor based on lever amplification.

Background technique

Piezoelectric linear motor is a new type of linear actuator, which has developed rapidly in recent years and has attracted extensive attention from researchers at home and abroad. It uses the inverse piezoelectric effect of piezoelectric materials and generally has a specific structural form. Piezoelectric linear motors have a high thrust-to-weight ratio, are easy to miniaturize, can directly generate linear output, have simple structure, fast response, high position and speed control accuracy, and no electromagnetic interference, etc., which can meet the high-tech requirements for precision positioning technology . Currently, researchers have developed a wide variety of piezoelectric linear motors, some of which have been commercialized.

Piezoelectric linear motors can be divided into two types: resonant type and non-resonant type according to the different excitation methods of piezoelectric devices for driving feet. Deformation, and then driven by this deformation, there are mainly standing wave type, traveling wave type, surface acoustic wave type and modal composite type, etc. Most of the non-resonant piezoelectric linear motors use their own large deformation (up to micron level) The stacked piezoelectric element is used as the driving element, mainly including direct drive type, inchworm principle type, displacement amplification type and inertial impact type.

In the non-resonant piezoelectric linear motor, the direct drive motor is directly driven by the deformation of the piezoelectric element, with high position resolution and large output thrust, but the stroke is small; the inchworm principle motor uses the vibration between multiple piezoelectric elements. The alternating driving and clamping in a specific relationship realizes high-precision stepping and has a large stroke, but this type of motor requires high machining accuracy, and the output thrust is usually small.

Contents of the invention

The technical problem to be solved by the present invention is to provide a non-resonant piezoelectric linear motor driven by bipeds based on lever amplification, using laminated piezoelectric ceramics as the main driving element, and rationally arranging laminated piezoelectric ceramics on the stator assembly position, using the lever mechanism and the hinge mechanism to realize the displacement amplification output of the laminated piezoelectric ceramics, so that the piezoelectric linear motor can output a large linear speed and thrust, theoretically has equal bidirectional output performance, and can produce a large Travel, high precision, good stability. The problem of low motor output stability caused by machining errors due to small output displacement of laminated piezoelectric ceramics in the prior art is solved.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A biped-driven non-resonance piezoelectric linear motor based on lever amplification of the present invention includes a stator assembly, a linear guide rail, a pretensioning device, a stator fixing plate and a bottom plate; the stator assembly is fixedly connected to the stator fixing plate , the front end of the stator assembly is provided with a mover guide rail, and the rear end is connected to a preload device; there is a preload spring in the preload device, and the front end of the stator assembly is kept in contact with the mover guide rail under the pressure generated by the deformation of the preload spring. Contact; the mover guide rail, pre-tensioning device and stator fixing plate are all installed on the base

The stator assembly includes a stator structure, laminated piezoelectric ceramics, pads and pre-tightening screws; the stator assembly includes two driving feet, and the driving feet are arranged up and down.

The stator structure is divided into a stator main body and a stator mounting plate, and the stator main body and the stator mounting plate are connected by a parallelogram flexible hinge mechanism.

There are two groups of parallelogram flexible hinge mechanisms in the stator body, the two groups of parallelogram flexible hinge mechanisms are arranged in series and the generated displacements are perpendicular to each other.

There are holes on each side of the L-shaped periphery of the stator main body, and the screws pass through the holes and are connected with the threaded holes on the parallelogram flexible hinge mechanism.

The laminated piezoelectric ceramics need to be installed in cooperation with two semicircular pads, the flat part of the pads is in contact with the laminated piezoelectric ceramics, and the arc surface part of the pads is in contact with the main body of the stator.

The pre-tightening device includes a pre-tightening support block, a pre-tightening block, a pre-tightening spring, a pre-tightening top block and a locking screw; the pre-tightening support block is fixed on the bottom plate, and there are threaded holes on the pre-tightening support plate for Cooperate with the locking screw, push the pre-tightening block to compress the pre-tightening spring so that the pre-tightening block presses against the stator assembly, and tighten the locking screw to complete the application of the pre-tightening force.

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

The piezoelectric element in the biped-driven non-resonant piezoelectric linear motor adopts a piezoelectric stack, the output displacement and output force are large, and the positioning accuracy is high. The structure works in a non-resonant mode, which is not easily disturbed by environmental factors. Resonant motors using piezoelectric ceramics are more stable;

The structure of the stator assembly is small and exquisite, and the two driving feet distributed up and down can maintain a good contact state with the guide rail of the mover;

The components are simple in structure, less difficult to process and convenient to connect.

Description of drawings

Fig. 1 is the structure diagram of piezoelectric linear motor;

Fig. 2 is a structural exploded view of the stator assembly part of the piezoelectric linear motor;

Fig. 3 is an exploded view of the structure of the pretensioning device in the piezoelectric linear motor;

Fig. 4 is the excitation voltage signal diagram of the piezoelectric linear motor in the working mode;

Fig. 5 is a diagram of the motion mechanism of the piezoelectric linear motor in one cycle;

Among them, the marks in the figure are: 1-stator assembly; 2-sliding rail; 3-bottom plate; 4-stator fixing plate; 5-pretensioning device

11-Laminated piezoelectric ceramic group; 12-Stator mounting plate; 13-Screws; 14-Stator main body.

51-screw; 52-pretension block; 53-pretension spring; 54-pretension support plate; 55-pretension top block; 56-locking screw.

Detailed ways

The technical scheme of the present invention is described in detail below in conjunction with accompanying drawing:

As shown in FIG. 1 , the piezoelectric linear motor according to the present invention is composed of a stator assembly 1 , a slide rail 2 , a bottom plate 3 , a stator fixing plate 4 , and a preloading device 5 . The front end of the stator assembly 1 is in close contact with the wear-resistant ceramic strip on the slide rail 2 under the action of the pre-tensioning device 5, so that the motor has the function of self-locking when power is off; the stator assembly 1 is fixed on the stator fixing plate 4; Both the stator fixing plate 4 and the pretensioning device 5 are fixed on the bottom plate 3 .

As shown in the stator structure diagram of FIG. 2 , the stator assembly 1 includes a laminated piezoelectric ceramic group 11 , a stator mounting plate 12 , screws 13 , and a stator body 14 . There are two sets of parallelogram flexible hinge mechanisms in the stator main body 14, the two sets of mechanisms are arranged in series and the displacements generated are perpendicular to each other. The stator main body 14 is an L-shaped structure. The stator structure is divided into a stator main body 14 and a stator mounting plate 12, which are connected by a parallelogram flexible hinge mechanism to realize micro-displacement of the stator main body. The stator fixing plate 4 is fixed to the bottom plate 3 with screws, and the stator assembly 1 is fixed on the stator fixing plate 4 with screws.

Four stacked piezoelectric ceramic groups are installed between the L-shaped outer frame of the stator body and the parallelogram flexible hinge mechanism; there are holes on each side of the L-shaped periphery, and the screws pass through the holes and the parallelogram flexible hinge mechanism The threaded hole on the top is connected, and the pre-tightening screw can be tightened to apply a pre-tightening force to the laminated piezoelectric ceramic group; the parallelogram flexible hinge mechanism can reduce the rotation of the driving foot at the top of the stator.

As shown in Figure 3, the pre-tightening device 5 comprises screw 51, pre-tightening block 52, pre-tightening spring 53, pre-tightening support plate 54, pre-tightening top block 55, locking screw 56; There are threaded holes on the pre-tightening support plate, It is used to cooperate with the locking screw. The pre-tightening spring is set on the shaft of the pre-tightening block, and the pre-tightening block is pushed to compress the pre-tightening spring so that the pre-tightening block presses against the stator assembly. Tighten the locking screw to complete the application of pre-tightening force .

FIG. 4 shows the voltage signals applied to the four groups of laminated piezoelectric ceramics 11 , 12 , 21 , 22 by the piezoelectric motor in the working mode. Figure 5 shows the working mechanism diagram of the piezoelectric motor in one cycle, in which the two sets of driving units originally arranged up and down are placed left and right in the figure for convenience. Combining Figure 4 and Figure 5, where a (c2) represents the moment after t=0 (t=T), b1 represents the moment before t=T/2, b2 represents the moment after t=T/2, c1 represents the moment before t=T.

At time a, a square wave signal with a high level of A is added to the stacked piezoelectric ceramic group 12 of the left drive unit, which elongates in the positive direction of the y-axis, and the top end is pressed against the mover, and the ceramic group 21 of the right drive unit The voltage drops uniformly from A, and the top moves to the negative direction of the x-axis;

At time b1, the voltage of the stacked piezoelectric ceramic group 12 of the left drive unit is boosted to A, the slide rail moves a certain distance in the positive direction of the x-axis under the action of the driving foot, and the voltage drop of the stacked piezoelectric ceramic group 21 of the right drive unit is 0, the top returns to the initial position;

At moment b2, the voltage on the laminated piezoelectric ceramic group 12 becomes 0, the top of the left drive unit retracts, the voltage on the laminated piezoelectric ceramic group 22 of the right drive unit is A, and the top pushes against the mover;

At time c1, the voltage drop on the laminated piezoelectric ceramic group 11 is 0, the top of the left drive unit returns to the initial position, the voltage on the laminated piezoelectric ceramic group 21 of the right drive unit increases to A at a constant speed, and the slide rail is driving Move a certain distance in the positive direction of the x-axis under the action of the feet.

Based on the description of the preferred embodiments of the present invention, it should be clear that the present invention defined by the appended claims is not limited to the specific details set forth in the description above, and there are many aspects of the present invention that do not depart from the spirit or scope of the present invention. Obvious changes are also possible to achieve the object of the present invention.

Claims (3)

1. the biped driving off-resonance piezoelectric linear motor based on lever amplification, it is characterised in that：Including a stator assembly, Line slideway, pre-tightening apparatus, stator fixed plate and bottom plate；The stator assembly is fixedly connected in stator fixed plate, stator The front end of assembly is equipped with mover guide rail, rear end connection pre-tightening apparatus；There are preloading spring, stator assembly in the pre-tightening apparatus Under the pressure effect that preloading spring deformation produces, front end keeps contacting with mover guide rail；The mover guide rail, pre-tightening apparatus and Stator fixed plate is mounted on base；

The stator assembly includes stator structure body, stacked piezoelectric ceramics, cushion block and pre-loading screw；The stator assembly Comprising two driving foots, arrangement above and below the driving foot；

The stator structure body is divided into stator body and stator installing plate, passes through between stator body and the stator installing plate Parallelogram flexure hinge mechanism connects；

There are two groups of parallelogram flexure hinge mechanisms, two groups of parallelogram flexure hinge mechanisms in the stator body Arranged in series and caused displacement is orthogonal；

Each side Shang Douyou holes of the L-type periphery of the stator body, the spiral shell on Bolt through holes and parallelogram mechanism Pit connects.

2. the biped driving off-resonance piezoelectric linear motor based on lever amplification as claimed in claim 1, it is characterised in that：Institute State stacked piezoelectric ceramics and coordinate installation with two pieces of semicircular cushion blocks, the planar section and stacked piezoelectric ceramics of the cushion block connect Touch, the cambered surface part of the cushion block and stator body contact.

3. the biped driving off-resonance piezoelectric linear motor based on lever amplification as claimed in claim 1, it is characterised in that：Institute The pre-tightening apparatus stated includes pretension supporting block, pretension block, preloading spring, pretension jacking block and lock-screw；The pre- compact schemes Block is fixed on bottom plate, has threaded hole in pretension support plate, for the cooperation with lock-screw, promotes pretension jacking block compression pretension Spring causes pretension block to hold out against stator assembly, tightens the application that lock-screw completes pretightning force.