CN104467526B - Inertia stick-slip cross-scale motion platform capable of achieving unidirectional movement - Google Patents

Abstract

The invention provides an inertial stick-slip cross-scale motion platform that realizes one-way motion. The balance weight, the piezoelectric ceramic actuator and the main mass are combined with each other. When the positive and negative electrodes of the piezoelectric ceramic actuator When a forward or reverse voltage is applied, it slightly elongates or shortens in the length direction and drives the counterweight and the main mass to move, thereby achieving millimeter-level travel and nanometer-level positioning accuracy. Compared with other motion platforms, it has the advantages of simple structure, fast and precise positioning with large strokes and easy multi-degree-of-freedom drive, and does not require special position holding devices.

Description

An inertial stick-slip cross-scale motion platform for unidirectional motion

technical field

The invention belongs to the technical field of precision motion, and in particular relates to an inertial stick-slip cross-scale motion platform for realizing one-way motion.

Background technique

With the rapid development of micro/nano technology, there is an urgent need for sub/micron, micro /Nanoscale ultra-precise drive mechanism.

Cross-scale precision motion technology with nanometer-level motion resolution and millimeter-level motion travel is the key technology in the field of micro-drives. Compared with other cross-scale motion driving methods, the inertial stick-slip drive has simple driving principle, convenience, and simple control, and has the advantages of large motion range, high resolution, simple structure, easy miniaturization, and precise positioning, so the inertial stick-slip Driving is a method that is widely used in the current cross-scale driving. The working principle of inertial stick-slip drive is mainly to use friction as the driving source, and use the stick-slip effect to realize the tiny movement of the driven body. The difference between the friction forces can ultimately achieve precise motion across scales.

Piezoelectric ceramic actuator is a new type of micro-displacement device developed in recent years. It has been widely used as a driving element in precision machinery for its advantages of small size, large driving force, high resolution, and easy control. Piezoelectric ceramics work by using the inverse piezoelectric effect of piezoelectric materials, and can be driven only by the magnitude of the applied electric field. Piezoelectric ceramics overcome the shortcomings of previous mechanical, hydraulic, pneumatic, electromagnetic actuators such as large inertia, slow response, complex structure, and poor reliability. They have small size, compact structure, no mechanical friction, no gap, and high resolution High, fast response, no heat, no magnetic field interference, and can be used in low temperature and vacuum environments, etc., are widely used in micro-positioning technology. This controllable precision micro-displacement actuator will surely be used in many technical fields in the future. play an inestimable role.

As mentioned above, although the piezoelectric ceramic actuator has the advantages of high-precision displacement output, its output displacement is quite small at the same time, which cannot meet the application occasions with large micro-displacement output requirements. The output displacement of the ceramic actuator is accumulated to meet the needs of large stroke and high precision positioning. At present, the precision driving devices based on piezoelectric ceramic structure can be mainly divided into direct drive type, lever amplification type, ellipse amplification type, rhombus amplification type and inchworm type precision positioning platform according to their working methods.

Among them, the direct drive precision positioning platform mainly uses piezoelectric ceramics to directly drive the double parallel plate flexible mechanism. Using this mechanism can eliminate the coupling displacement in principle and the displacement resolution is high, but the deformation of the piezoelectric body is very small, making the positioning mechanism The motion stroke is very limited, which is greatly restricted in practical application. In the prior art, the utility model patent with publication number 202695554U has announced related technologies.

The main purpose of the lever-amplified precision positioning platform is to enlarge the range of motion of piezoelectric ceramics. Through the principle of lever amplification and the flexible hinge mechanism with a rotating pair, the rotation along the fulcrum is realized. Through the lever mechanism, the magnification can reach 2-3 times. The movement range of the precision positioning platform driven by piezoelectric ceramics is effectively improved, but at the same time as the movement range is enlarged, there is also a small angle change due to the lever-type amplification, which will bring a small angle error to the final enlarged displacement . In the prior art, the utility model patent with publication number 2587600, the invention patent with publication number 103111990A, and EP0624912A1 and DE4315238A1 patents disclosed by the European Patent Office have announced related technologies.

The elliptical and rhombus-shaped precision positioning platforms use the principle of pressure bar instability to achieve motion amplification, and the motion amplification mechanism is designed based on the principle of pressure bar instability in material mechanics. When the piezoelectric ceramic is elongated, the two ends of the mechanism are pushed from the inside to the outside, the curvature of the arc-shaped thin-walled shell changes, and the highest point of the arc surface moves downward, and the downward displacement is greater than the elongation of the ceramic itself. The displacement is much larger, i.e. the displacement is amplified. However, the stress at the arc of this type of mechanism is relatively large, which is prone to stress concentration. In the prior art, the utility model patents whose publication numbers are 2628237 and 2726829 have announced related technologies.

The inchworm precision positioning platform is named after the movement principle of reptiles in the biological world. It converts the tiny vibration displacement of the piezoelectric body in a certain way to form a continuous or step-by-step precision displacement drive mechanism. The difference from the direct-acting mechanism is that the mechanism can achieve precise displacement with a large stroke through the use of the clamping device. FIG. 1 is a schematic diagram of the main structure of an inchworm precision positioning platform in the prior art. As shown in Figure 1, 1 and 3 are piezoelectric cylinders that can expand radially, leaving a small gap between them and the straight rod, and 2 is a circular tube that can expand axially. When the driving circuit is controlled, 1 shrinks and compresses on the straight rod, while 3 opens and 2 stretches, 3 moves one step to the right, then 3 shrinks and tightens, 1 expands, and 2 shortens, then 1 moves one step to the right . In this way, the whole moving part composed of 1, 2, and 3 has moved one step to the right, and it goes back and forth like this to form a continuous precision displacement. In the prior art, invention patents with application numbers 201110245339.4, 201310202368.1, 201210475674.8 and 201310491303.3 respectively have published related technologies.

The above four precision positioning platforms are all driven by piezoelectric ceramics to achieve nanoscale high-precision positioning. Although the first three are different in one-dimensional realization structure and displacement amplification method, the displacement of such platforms is limited to within a few hundred microns, which cannot achieve precise positioning across scales. The inchworm-type precision positioning platform is a precision positioning platform that accumulates tiny displacements to achieve nanometer-level precision and millimeter-level strokes through the principle of inchworms. However, due to the complex structure of the positioning platform, the processing and assembly accuracy of this platform is higher. , which ultimately affects the motion accuracy and consistency of the cross-scale precision motion platform. Therefore, these existing technologies have technical problems such as complex manufacturing process and high manufacturing cost in ensuring the consistency of mass production of the cross-scale precision motion platform.

In addition, the use of the inertial stick-slip driving principle is conducive to the formation of inertial impact force, which is a new way to construct the motion mechanism. In most cases, the inertial impact force is obtained by mechanical impact, which is relatively difficult to control and easily causes damage to the mechanism.

To sum up, the present invention provides an inertial stick-slip cross-scale motion platform that realizes unidirectional motion to solve the problems existing in the prior art.

Contents of the invention

The invention provides an inertial stick-slip cross-scale motion platform that realizes unidirectional motion, which includes a counterweight, a piezoelectric ceramic actuator, and a main mass. Both ends of the piezoelectric ceramic actuator are respectively connected to the distribution Heavy block and main mass block. The piezoelectric ceramic actuator is used to slightly elongate or shorten in the length direction when a forward or reverse voltage is applied between the positive and negative electrodes, and drive the counterweight and the main mass to move.

Preferably, the cross-scale motion platform further includes a bottom plate, the bottom plate is finely ground by a grinder, the surface roughness level is Ra0.4, and the processing direction is on the same straight line.

Preferably, the cross-scale motion platform further includes an inertial connection block, and the inertial connection block is connected to the counterweight by threads.

Preferably, the cross-scale motion platform further includes a front-end nut, and the front-end nut is connected to the moving part of the cross-scale motion platform through threads.

Preferably, the cross-scale motion platform further includes an optical axis, and the optical axis is connected to the front nut.

Preferably, the cross-scale motion platform further includes an upper pressing block and a supporting block, the upper pressing block and the supporting block are processed as a whole and obtained by cutting, and the upper pressing block is in line contact with the optical axis.

Preferably, the cross-scale motion platform further includes two pre-tightening jackscrews, which are used to lock the movement of the upper pressing block and the supporting block due to mechanical gaps during the movement.

Preferably, the cross-scale motion platform further includes M3 nuts, and the M3 nuts are used to fix the main mass and adjust the main mass.

Preferably, the cross-scale motion platform further includes a compression rod and a compression spring, and the compression rod and compression spring are used to adjust the friction generated by the cross-scale motion platform during movement by adjusting the positive pressure.

Preferably, the cross-scale motion platform further includes two M4 nuts and a spring pressing plate, the two M4 nuts are used to make the spring pressing plate compress the compression spring.

Through the inertial stick-slip cross-scale motion platform that realizes unidirectional motion provided by the present invention, the balance weight, piezoelectric ceramic actuator and main mass are combined with each other, when the positive and negative electrodes of the piezoelectric ceramic actuator When a forward or reverse voltage is applied, it slightly elongates or shortens in the length direction and drives the counterweight and the main mass to move, thereby achieving millimeter-level travel and nanometer-level positioning accuracy. Compared with other motion platforms, it has the advantages of simple structure, fast and precise positioning with large strokes and easy multi-degree-of-freedom driving, and does not require special position holding devices.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic diagram of the main structure of an inchworm type precision positioning platform in the prior art;

Fig. 2 is a schematic diagram of the motion process of an inertial stick-slip cross-scale motion platform that realizes unidirectional motion provided by a preferred embodiment of the present invention;

Fig. 3 is a schematic diagram of driving signals of an inertial stick-slip type cross-scale motion platform that realizes unidirectional motion provided by a preferred embodiment of the present invention;

Fig. 4 is a schematic diagram of the overall structure of an inertial stick-slip cross-scale motion platform that realizes unidirectional motion provided by a preferred embodiment of the present invention;

Fig. 5 is a schematic diagram of the structure of the main part of the inertial stick-slip type cross-scale motion platform that realizes one-way motion provided by a preferred embodiment of the present invention;

Fig. 6 is a schematic cross-sectional view of the pressure block and the support block on the inertial stick-slip type cross-scale motion platform provided by a preferred embodiment of the present invention.

detailed description

Hereinafter, the present invention will be described in detail with reference to the drawings and examples. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

Fig. 2 is a schematic diagram of the motion process of the inertial stick-slip cross-scale motion platform that realizes unidirectional motion provided by a preferred embodiment of the present invention. As shown in Figure 2, the inertial stick-slip cross-scale motion platform for unidirectional motion provided by the preferred embodiment of the present invention includes a main mass 4, a piezoelectric ceramic actuator 5 and a counterweight 6, and the piezoelectric Both ends of the ceramic actuator 5 are respectively connected to the main mass 4 and the counterweight 6 . The piezoelectric ceramic actuator 5 is used to slightly elongate or shorten in the length direction when a forward or reverse voltage is applied between the positive and negative electrodes, and to drive the main mass 4 and the counterweight 6 sports.

Fig. 3 is a schematic diagram of driving signals of an inertial stick-slip cross-scale motion platform for realizing unidirectional motion provided by a preferred embodiment of the present invention. As shown in Figure 3, combined with Figure 2, firstly a linear voltage rapidly increasing from a to b is applied to the piezoceramic actuator, the piezoceramic stretches rapidly, the counterweight moves to the right quickly, and the main mass Make small moves to the left. Then, from b to c, the control voltage decreases in a parabola, and the piezoelectric ceramics shrink gradually, so that the counterweight moves to the left and is continuously accelerated. When the voltage at point c is zero, the contraction of piezoelectric ceramics stops suddenly. According to the law of conservation of momentum, most of the momentum of the counterweight will be transferred to the main mass in the form of impact force, making the latter move a certain distance to the left. With the periodic change of the voltage, the main mass moves rapidly to the left with a small step size, so as to achieve the purpose of precise movement and positioning. Similarly, as long as the waveform or polarity of the voltage is changed, the main mass can be moved stepwise to the right. By controlling the frequency, waveform and amplitude of the excitation voltage, continuous motion with different step lengths can be realized.

Specifically, after the piezoelectric ceramic actuator stretches rapidly, it gradually contracts with a certain acceleration, and the counterweight will gain a certain momentum, impacting the main mass to make it move to the left by a small step overcoming the static friction force, periodically By driving the expansion and contraction of the piezoelectric ceramics, the inertial stick-slip motion platform can continuously make stepping motions to the left. Similarly, the piezoelectric ceramic actuator gradually stretches at a certain acceleration and then quickly contracts, and the counterweight will gain a certain momentum, impacting the main mass to overcome the static friction and move to the right by a small step, periodically driving The expansion and contraction of piezoelectric ceramics can make the inertial stick-slip motion platform continuously make stepping motions to the right. However, due to the difference between the rise and fall of the step signal generated by the driving power supply and the difference in the mechanical response time of the piezoelectric ceramic actuator when it is rapidly extended and contracted during the movement, the forward movement speed is greater than the reverse. direction movement speed. Due to the small expansion and contraction of piezoelectric ceramics, the minimum step size of several nanometers can be obtained for the inertial stick-slip motion platform, and the step size can be continuously adjusted with the driving voltage.

Figure 4 is a schematic diagram of the overall structure of the inertial stick-slip cross-scale motion platform that realizes one-way motion provided by a preferred embodiment of the present invention, and Figure 5 is a schematic diagram of the inertial stick-slip cross-scale motion platform that realizes one-way motion provided by a preferred embodiment of the present invention Schematic diagram of the main part of the motion platform. As shown in Figures 4 and 5, the inertial stick-slip cross-scale motion platform for realizing unidirectional motion provided by the preferred embodiment of the present invention includes a counterweight 4-2, a piezoelectric ceramic actuator 4-4, a main mass Blocks 4-6. Wherein, there are at least two counterweights, each of which is made of different materials and thicknesses, so as to achieve different inertial forces during driving by adjusting the mass of the counterweights. In this embodiment, there are two counterweights 4-2, which are made of brass and aluminum alloy respectively.

In addition, the inertial stick-slip cross-scale motion platform that realizes one-way motion provided by this embodiment also includes:

Bottom plate 4-1, the bottom plate 4-1 needs to be finely ground by a grinder, the surface roughness grade is Ra0.4 and the processing direction must be on the same straight line, and two rows of mounting holes perpendicular to each other need to be punched on the bottom plate 4-1, In order to facilitate the installation of the main structure in the direction of the minimum surface roughness of the bottom plate;

Inertia connection block 4-3, described inertia connection block 4-3 is connected with counterweight 4-2 by thread;

Front-end nut 4-5, the front-end nut 4-5 is connected with the moving part of the cross-scale motion platform through threads; here, the piezoelectric ceramic actuator 4-4 is connected to the inertial connection block and the front end through epoxy glue The nut is firmly connected, and after the bonding is completed, it needs to be pressurized and cured to achieve the best connection performance;

M3 nut 4-7, the M3 nut 4-7 is used to fix the main mass block 4-6 and adjust it; here, the main mass block 4-6 is clamped with the front end nut through the M3 nut, which can be up and down It can be adjusted to prevent it from being stuck during the movement, and it can play a supporting role to prevent the movement platform from "falling down" due to the unstable center of gravity during the movement;

Compression rod 4-8 and compression spring 4-9, described compression rod 4-8 and compression spring 4-9 are used for adjusting the frictional force that described cross-scale motion platform produces during motion by adjusting positive pressure;

The upper pressing block and the supporting block 4-12, the upper pressing block and the supporting block 4-12 are integrally processed and obtained by cutting, and the upper pressing block is in line contact with the optical axis. Fig. 6 is a schematic cross-sectional view of the pressure block and the support block on the inertial stick-slip type cross-scale motion platform provided by a preferred embodiment of the present invention. As shown in Figure 6, on the one hand, it can prevent jamming due to too many contact surfaces during the movement, and on the other hand, it can improve the consistency of the dynamic friction factors of the contact part;

The optical axis 4-10, the optical axis 4-10 is connected with the front nut 4-5, and contacts with the upper pressing block and the supporting block 4-12 to generate frictional force;

There are two pre-tightening jackscrews 4-11, which are used to lock the movement of the upper pressing block and the supporting block 4-12 due to the mechanical gap during the movement;

Two M4 nuts 4-13 and a spring pressing plate 4-14, the two M4 nuts 4-13 are used to make the spring pressing plate 4-14 compress the compression spring 4-9.

The inertial stick-slip cross-scale motion platform that realizes one-way motion provided by the present invention adopts the driving mechanism that the rapid deformation of the piezoelectric element generates inertial impact force, and through the design of the circuit system, an asymmetrical electrical signal is output, so that the piezoelectric element The motion form of rapid extension and slow retraction, or slow extension and rapid retraction can be generated, and under the action of alternating electrical signals, the driving mechanism generates macroscopic one-way motion. Under this premise, a quality adjustment mechanism, a positive pressure adjustment mechanism and piezoelectric ceramics that are easy to replace are designed to achieve the optimal output of the inertial stick-slip cross-scale precision motion platform by adjusting parameters. This platform is easy to process and assemble, effectively improves the output performance of the stick-slip drive cross-scale precision motion platform, can simply and effectively ensure the motion accuracy and consistency of the stick-slip drive cross-scale precision motion platform, is suitable for mass production, and is very suitable for applications such as Micro-nano operation, micro-robots, biological micro-manipulation, digital products, and precision drive systems are used in various fields that require structural miniaturization and large-scale precise positioning.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

1. a kind of across yardstick motion platform of inertia stick-slip formula realizing one-way movement is it is characterised in that include balancing weight, piezoelectricity pottery Porcelain actuator and parenchyma gauge block, described piezoelectric actuator two ends connect described balancing weight and parenchyma gauge block respectively,

Described piezoelectric actuator, for when positive and negative interpolar applies voltage forward or backwards, making small in length direction Elongate or shorten, and drive described balancing weight and the motion of parenchyma gauge block；

Also include front end nut, one end of front end nut is connected with piezoelectric actuator；

Also include upper holder block, support block and the optical axis being connected with the front end nut other end, described upper holder block and support block are integrated Cut after processing and obtain, and described upper holder block is linear contact lay with optical axis；Described optical axis is located between upper holder block and support block；

Also include compressor arm and compression spring, compressor arm and compression spring are positioned at the top of upper holder block；Described compressor arm and compression Spring is used for adjusting, by adjusting normal pressure, the frictional force that described across yardstick motion platform produces in motor process；

Also include two m4 nuts and spring bearer plate, spring bearer plate is located at the top of constrictor and compression spring, m4 nut is fixed On spring bearer plate；Described two m4 nuts, are used for making spring bearer plate compress described compression spring.

2. across yardstick motion platform according to claim 1 it is characterised in that also including base plate, make pottery by described pouring weight, piezoelectricity Porcelain actuator and parenchyma gauge block are respectively positioned on base plate；Described base plate is refined by grinding machine, and roughness grade is ra0.4, and plus Work direction is on same straight line.

3. it is characterised in that also including inertia contiguous block, inertia connects across yardstick motion platform according to claim 1 One end of block is connected with balancing weight, and the other end is connected with piezoelectric actuator；Described inertia contiguous block passes through spiral shell with balancing weight Stricture of vagina connects.

4. across yardstick motion platform according to claim 1 it is characterised in that described front end nut pass through screw thread with described Connect across the motion parts of yardstick motion platform.

5. across yardstick motion platform according to claim 1 is it is characterised in that also include pretension jackscrew, described pre- presses closer Silk is two, and pretension jackscrew is located at the two ends of upper holder block, for locked upper holder block and support block in motor process due to machinery Gap and the play that exists.

6. it is characterised in that also including m3 nut, m3 nut is located at master to across yardstick motion platform according to claim 1 The outside of mass；Described m3 nut is used for fixing parenchyma gauge block and adjusting described parenchyma gauge block.