CN204481717U - A kind of inertia stick-slip formula realizing bidirectional-movement is across yardstick precision movement platform - Google Patents

Abstract

The utility model discloses an inertial stick-slip cross-scale precision motion platform for realizing two-way motion. The platform includes a base plate, a support module located on the base plate, and two motion modules symmetrically installed on both sides of the support module. The motion module includes a counterweight, a piezoelectric ceramic actuator and a main mass, the piezoelectric ceramic actuator includes a positive pole and a negative pole, and the positive pole and negative pole of the piezoelectric ceramic actuator are used to be connected with a driving signal, and the piezoelectric ceramic actuator is connected with a driving signal. The driving signal is a combination of a linear voltage and a nonlinear voltage, wherein the rate of change of the nonlinear voltage gradually increases. The inertial stick-slip cross-scale precision motion platform of the utility model has a simple structure, can realize fast and large stroke precision positioning, can easily realize multi-degree-of-freedom driving, and does not need a special position holding device.

Description

An inertial stick-slip cross-scale precision motion platform for bidirectional motion

technical field

The utility model relates to the technical field of precision motion, in particular to an inertial stick-slip cross-scale precision motion platform for realizing bidirectional 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.

The utility model adopts the piezoelectric ceramic actuator as the driving device of the precision positioning workbench. The piezoelectric ceramic actuator is a new type of micro-displacement device developed in recent years. It has small volume, large driving force, high resolution, The advantages of easy control and other advantages have been widely used as driving components in precision machinery. 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. Although it has the advantage 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. In practical applications, it is often necessary to accumulate the output displacement of piezoelectric ceramic actuators. To meet the needs of large travel and high precision positioning. Therefore, this patent adopts the inertial stick-slip principle to solve the problem of small output displacement of the piezoelectric ceramic actuator. 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.

For example, the Chinese patent with the patent number CN202695554U, 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 very high, but the piezoelectric body is deformed. It is very small, so that the movement stroke of the positioning mechanism is very limited, which is greatly restricted in practical application.

For example, the Chinese patent with the patent No. CN2587600 and CN103111990A, the European patent with the patent No. EP0624912A1, and the German patent with the patent No. DE4315238A1. The principle, and the flexible hinge mechanism with the rotating pair realizes the rotation along the fulcrum, and the magnification can reach 2-3 times through the lever mechanism. 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 .

For example, the Chinese patents with patent numbers CN2628237 and CN2726829, elliptical and diamond-shaped zoom-in 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.

For example, the Chinese patent applications with application numbers CN201110245339.4, CN201310202368.1, CN201210475674.8 and CN201310491303.3, the inchworm-type precision positioning platform is named after imitating 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. Figure 1 is a schematic diagram of the structure of the inchworm-type precision positioning platform, in which 1 and 3 are piezoelectric cylinders that can expand radially, with 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.

Although the above four precision positioning platforms are all driven by piezoelectric ceramics, they can achieve nanometer-level 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 uses the principle of the inchworm to accumulate tiny displacements to achieve a precision positioning platform with nanometer-level precision and millimeter-level travel. However, due to the complex structure, the processing and assembly precision requirements of this platform are relatively high, which ultimately affects the motion accuracy and consistency of the cross-scale precision motion platform. Therefore, these existing technologies play an important role in ensuring the mass production of the cross-scale precision motion platform. In terms of consistency, there are technical problems such as complex manufacturing process and high manufacturing cost.

Therefore, in view of the above technical problems, it is necessary to provide an inertial stick-slip cross-scale precision motion platform that realizes bidirectional motion.

Utility model content

In view of this, in order to solve the problems in the prior art, the utility model provides an inertial stick-slip cross-scale precision motion platform that realizes bidirectional motion, so as to realize millimeter-level travel, nanometer-level positioning accuracy, and forward and reverse rotation. The movement speed is consistent. Adopting the principle of inertial stick-slip drive, which is conducive to the formation of inertial impact force, drive is a new way to construct motion mechanisms. In most cases, inertial impact force is obtained by mechanical impact, which is relatively difficult to control and easy to cause damage to the mechanism. Because piezoelectric ceramic actuators have the advantages of fast response speed, high energy conversion efficiency, simple structure, and easy miniaturization, piezoelectric elements are one of the ideal power elements for constructing inertial stick-slip cross-scale precision motion platforms.

In order to achieve the above object, the technical solutions provided by the embodiments of the present invention are as follows:

An inertial stick-slip cross-scale precision motion platform that realizes two-way motion. The platform includes a base plate, a support module located on the base plate, and two motion modules symmetrically installed on both sides of the support module. Each of the motion modules includes a matching A weight, a piezoelectric ceramic actuator and a main mass block, the piezoelectric ceramic actuator includes a positive pole and a negative pole, the positive pole and the negative pole of the piezoelectric ceramic actuator are used to connect with a driving signal, and the driving signal is a linear voltage A combination of a nonlinear voltage and a nonlinear voltage in which the rate of change of the nonlinear voltage increases gradually.

As a further improvement of the present invention, the counterweight at least includes a first counterweight and a second counterweight, and the first counterweight and the second counterweight are of different materials and thicknesses.

As a further improvement of the utility model, an inertia connection block is installed between the counterweight and the piezoelectric ceramic actuator, and a first nut is installed between the main mass and the piezoelectric ceramic actuator.

As a further improvement of the utility model, the support module includes a lower pressing block fixedly installed on the bottom plate, an upper pressing block located above the lower pressing block, and a pressing device located above the upper pressing block, the upper pressing block and Grooves are correspondingly arranged on the lower pressing block.

As a further improvement of the utility model, the pressing device includes a spring pressing plate arranged above the upper pressing block, a compression spring and a pressing rod between the spring pressing plate and the upper pressing block, and a spring for fixing the pressing rod and the spring. The second nut of the pressure plate.

As a further improvement of the utility model, the movement modules are connected by an optical axis, the optical axis section is circular, and the optical axis is installed in the groove between the upper pressing block and the lower pressing block, and the optical axis It is in line contact with the upper pressing block and the lower pressing block.

As a further improvement of the present invention, a third nut is provided outside the main mass in the motion module, and the motion module is fixedly installed with the optical axis through the third nut.

As a further improvement of the utility model, the two ends of the upper pressing block are correspondingly installed with pre-tightening jackscrews.

As a further improvement of the present invention, the non-linear voltage decreases parabolically.

The utility model has the following beneficial effects:

The inertial stick-slip cross-scale precision motion platform of the utility model has a simple structure, can realize fast and large stroke precision positioning, can easily realize multi-degree-of-freedom driving, and does not need a special position holding device. The utility model is used in the fields of micro-electromechanical systems, modern cell biological engineering, ultra-precision machining, STM and AFM microscope scanning platforms, micro-nano operations, micro-miniature robots, and biological micro-operations because of its compact structure, no electromagnetic interference, and cross-scale precision. Positioning has broad application prospects.

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 accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments recorded in the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creative work.

Fig. 1 is the structural representation of the inchworm type precise positioning platform in the prior art;

Fig. 2 is a schematic structural diagram of the motion module in the inertial stick-slip cross-scale precision motion platform of the present invention;

Fig. 3 is a schematic structural diagram of the motion module in the inertial stick-slip cross-scale precision motion platform of the present invention that realizes two-way motion;

Fig. 4 is a schematic diagram of driving signals in a specific embodiment of the present invention;

Fig. 5 is a three-dimensional structural schematic diagram of an inertial stick-slip cross-scale precision motion platform in a specific embodiment of the present invention;

6 is a schematic diagram of the three-dimensional structure of the motion module in the inertial stick-slip cross-scale precision motion platform in a specific embodiment of the present invention;

Fig. 7 is a schematic diagram of the structure of the upper pressing block and the lower pressing block of the inertial stick-slip cross-scale precision motion platform in a specific embodiment of the present invention.

Detailed ways

The utility model will be described in detail below in conjunction with the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present utility model, and the structural, method, or functional changes made by those skilled in the art according to these embodiments are all included in the protection scope of the present utility model.

The utility model discloses an inertial stick-slip cross-scale precision motion platform for realizing two-way motion. The platform includes a base plate, a support module located on the base plate, and two motion modules symmetrically installed on both sides of the support module. Each motion module It includes a counterweight, a piezoelectric ceramic actuator and a main mass. The piezoelectric ceramic actuator includes a positive pole and a negative pole. The positive pole and negative pole of the piezoelectric ceramic actuator are used to connect with the driving signal, and the driving signal is a linear voltage. A combination of a nonlinear voltage and a nonlinear voltage in which the rate of change of the nonlinear voltage increases gradually.

This kind of mechanism is composed of main mass, counterweight and piezoelectric ceramics. When a sudden change of electrical signal is applied to it, the impact force composed of piezoelectric elements and inertial blocks can produce a reverse inertial impact force on the main body of the mechanism, and when the reverse impact force is greater than the friction force of the mechanism itself, the mechanism can produce sports.

As shown in FIG. 2 , the motion module in the present invention is composed of a laminated piezoelectric ceramic actuator connected to a main mass and a counterweight at both ends. A forward or reverse voltage is applied between the positive and negative electrodes of the piezoelectric ceramic to make it slightly elongate or shorten in the length direction.

As shown in Figure 4, a linear voltage that increases rapidly from a to b is first applied, the piezoelectric ceramics elongates rapidly, the counterweight moves quickly to the right, and the main mass moves slightly to the left. Then, from b to c, the control voltage decreases in a parabola, and the piezoelectric ceramics gradually shrink, so that the counterweight moves to the left and is continuously accelerated. At point c the voltage is zero, and 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, causing the latter to 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. Obviously, as long as the frequency, waveform and amplitude of the excitation voltage are controlled, continuous motion with different step lengths can be realized.

In order to achieve the same forward and reverse speed, under the premise of the above working principle, it consists of a main body, two symmetrically arranged piezoelectric ceramics and two counterweights as shown in Figure 3 .

When it is necessary to realize the movement to the right, the piezoelectric ceramic 1 is connected to the driving signal as shown in FIG. 4 . Firstly, a rapidly increasing linear voltage is applied from a to b, the piezoelectric ceramic 1 stretches rapidly, the counterweight 1 moves quickly to the left, and the main mass moves slightly to the right at the same time. Then, from b to c, the control voltage decreases parabolically, and the piezoelectric ceramic 1 gradually shrinks, so that the counterweight moves to the right and is continuously accelerated. At point c the voltage is zero, and 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, causing the latter to move a certain distance to the right. With the periodic change of the voltage, the main mass moves rapidly to the right with a small step size, so as to achieve the purpose of precise movement and positioning.

When it is necessary to realize the leftward movement, the piezoelectric ceramic 2 is connected with the driving signal as shown in FIG. 4 . As mentioned above, the driving principle makes the main mass move rapidly to the left with a small step size, so as to achieve the purpose of precise movement and positioning. Since the left and right movements of the module are respectively driven by two piezoelectric ceramics, when driving, the two piezoelectric ceramics stretch rapidly and then shrink slowly, so the forward and reverse speeds can be consistent. Compared with other driving methods, the piezoelectric inertia stick-slip driving mechanism has the advantages of simple structure, fast and precise positioning with large strokes, easy realization of multi-degree-of-freedom driving, and no need for special position holding devices.

Referring to Fig. 5, Fig. 6 and Fig. 7, in a specific embodiment of the present invention, the inertial stick-slip cross-scale precision motion platform includes:

Bottom plate 4-1. The bottom plate needs to be finely ground by a grinder. The surface roughness level should be guaranteed to be Ra0.4 and the processing direction should be on the same straight line. Two rows of mounting holes perpendicular to each other should be punched on the bottom plate to facilitate the installation of the main structure on the The direction of the minimum surface roughness of the bottom plate;

Counterweight 4-2, in the present embodiment, counterweight comprises first counterweight (Cu) and second counterweight (Al), and two counterweights are different materials (brass and aluminum alloy), Different thicknesses to achieve different inertial forces when driving by adjusting the mass of the counterweight;

Inertia connection block 4-3, the inertia connection block can be threadedly connected with the counterweight;

Front-end nut 4-5 (the first nut), the front-end nut can be connected with the moving part through thread;

Piezoelectric ceramic actuator 4-4. The piezoelectric ceramic actuator is fixedly connected to the inertial connection block and the front nut through epoxy resin glue. After the bonding is completed, it needs to be pressurized and cured to achieve the best connection performance;

The main mass is 4-6, the main mass is clamped with the front nut (the first nut) by the M3 nut (the third nut), which can be adjusted up and down to prevent it from being stuck during the movement, and can play a supporting role to prevent movement The platform "falls over" due to the unstable center of gravity during the movement;

M3 nut 4-7 (the third nut), the M3 nut plays the role of fixing the main mass block and facilitating the adjustment of the main mass block;

The compression rod 4-8 and the compression spring 4-9, the compression rod and the compression spring can adjust the frictional force of the mechanism during the movement by adjusting the positive pressure;

Optical axis 4-10, the optical axis is connected with the front nut, and the upper and lower pressing blocks are in contact with each other to generate friction;

Pre-tightened top wire 4-11, there are two pre-tightened top wires to prevent the movement of the upper and lower pressing blocks due to mechanical gaps during the movement and achieve the purpose of locking;

The upper pressing block and the lower pressing block 4-12, the upper pressing block and the lower pressing block are processed as a whole and finally cut, and the middle is a square structure as shown in Figure 6, which is in line contact with the optical axis. On the one hand, it can prevent movement In the process, it is stuck due to too many contact surfaces. On the other hand, it can improve the consistency of the dynamic friction factors of the contact parts;

The M4 nut 4-13 (the second nut) and the spring pressing plate 4-14 make the spring pressing plate compress the compression spring through the two M4 nuts.

In this embodiment, the counterweight 4-2, the inertial connection block 4-3, the piezoelectric ceramic actuator 4-4, the front nut 4-5, the main mass 4-6, the M3 nut 4-7 and the optical axis 4 -10 together form a symmetrical motion module, wherein each counterweight is composed of two different first counterweights and second counterweights, in other embodiments, the number of counterweights can also be set to other Quantity; compression rod 4-8, compression spring 4-9, pre-tightening jackscrew 4-11, upper pressing block and lower pressing block 4-12, M4 nut 4-13 constitute supporting device together, in other embodiments Other configurations are also possible.

The working principle of the utility model is shown in Figure 3. It consists of a main mass (equivalent to the combination of two main masses and optical axes of the two motion modules in this embodiment), two piezoelectric ceramic actuators and two The heavy block consists of three parts.

When it is necessary to realize the movement to the right, the piezoelectric ceramic 1 is connected to the driving signal as shown in FIG. 4 . Firstly, a linear voltage that increases rapidly from a to b is applied, the piezoelectric ceramic 1 stretches rapidly, the counterweight 1 moves quickly to the left, and the main mass moves slightly to the right at the same time. Then, from b to c, the control voltage decreases parabolically, and the piezoelectric ceramic 1 gradually shrinks, so that the counterweight moves to the right and is continuously accelerated. At point c the voltage is zero, and 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, causing the latter to move a certain distance to the right. With the periodic change of the voltage, the main mass moves rapidly to the right with a small step size, so as to achieve the purpose of precise movement and positioning.

When it is necessary to realize the leftward movement, the piezoelectric ceramic 2 is connected with the driving signal as shown in FIG. 4 . As mentioned above, the driving principle makes the main mass move rapidly to the left with a small step size, so as to achieve the purpose of precise movement and positioning. Since the leftward and rightward movements of the mechanism are respectively driven by two piezoelectric ceramics, when driven, the two piezoelectric ceramics first stretch rapidly and then shrink slowly. Therefore, it can overcome the difference of the step signal generated by the drive power supply when it rises and falls and the difference in the mechanical response time of the piezoelectric ceramic actuator when it is rapidly extended and contracted. direction movement speed. Due to the small expansion and contraction of piezoelectric ceramics, the minimum step size of a few nanometers can be obtained for the inertial stick-slip motion platform, and the step size is continuously adjustable with the driving voltage.

Further, referring to FIG. 4 , the drive signal in this embodiment is a linear voltage from a to b, and a nonlinear voltage from b to c, and the nonlinear voltage decreases parabolically. In other embodiments, the nonlinear voltage does not necessarily have a parabolic shape, but may be other curves with gradually increasing rates of change, such as decreasing in a circular arc shape.

It can be seen from the above technical solutions that the inertial stick-slip cross-scale precision motion platform provided by the utility model has the following beneficial effects:

Since piezoelectric ceramics have the characteristics of good response characteristics, no electromagnetic interference, high control precision, and the same speed of forward and reverse motion, a driving mechanism that uses the rapid deformation of piezoelectric elements to generate inertial impact force is designed. Through the design of the circuit system, the output The asymmetric electrical signal enables the piezoelectric element to produce a motion form of rapid extension and slow retraction, or slow extension and rapid retraction. Under the action of alternating electrical signals, the driving mechanism produces macroscopic two-way motion. On the premise of this motion principle, the quality adjustment mechanism and positive pressure adjustment mechanism are designed, and the piezoelectric ceramics can be easily replaced, so as to adjust the parameters to achieve the optimal output of the inertial stick-slip cross-scale precision motion platform;

The platform of the utility model is convenient for processing and assembly, thereby effectively improving the output performance of the stick-slip drive cross-scale precision motion platform, which can simply and effectively ensure the motion accuracy and consistency of the stick-slip drive cross-scale precision motion platform, and is suitable for mass production. It is very suitable for applications in various fields that require structure miniaturization and large-scale precise positioning, such as micro-nano manipulation, micro-miniature robots, biological micro-manipulation, digital products, and precision drive systems.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from all points of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, so it is intended to fall within the scope of the claims All changes within the meaning and range of equivalents of the required elements are included in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (8)

1. An inertial stick-slip cross-scale precision motion platform that realizes two-way motion is characterized in that the platform includes a base plate, a support module positioned on the base plate, and two motion modules symmetrically installed on both sides of the support module, each The motion module includes a counterweight, a piezoelectric ceramic actuator and a main mass, the piezoelectric ceramic actuator includes a positive pole and a negative pole, and the positive pole and negative pole of the piezoelectric ceramic actuator are used to be connected with a driving signal, so The driving signal is a combination of a linear voltage and a nonlinear voltage, wherein the rate of change of the nonlinear voltage gradually increases. 2. The cross-scale precision motion platform according to claim 1, wherein the counterweight comprises at least a first counterweight and a second counterweight, and the first counterweight and the second counterweight Blocks are of different materials and thicknesses. 3. The cross-scale precision motion platform according to claim 1, wherein an inertial connection block is installed between the counterweight and the piezoelectric ceramic actuator, and the main mass and the piezoelectric ceramic actuator A first nut is installed between the devices. 4. The cross-scale precision motion platform according to claim 1, wherein the support module includes a lower pressing block fixedly mounted on the base plate, an upper pressing block positioned above the lower pressing block, and a lower pressing block positioned above the upper pressing block The pressing device, the upper pressing block and the lower pressing block are correspondingly provided with grooves. 5. The cross-scale precision motion platform according to claim 4, characterized in that, the pressing device comprises a spring pressing plate arranged above the upper pressing block, a compression spring and a pressing spring between the spring pressing plate and the upper pressing block Rod, and the second nut that is used to fix pressing rod and spring pressure plate. 6. The cross-scale precision motion platform according to claim 4, wherein the motion modules are connected by an optical axis, the cross-section of the optical axis is circular, and the optical axis is installed on the upper pressing block and the lower pressing block In the groove between, the optical axis is in line contact with the upper pressing block and the lower pressing block. 7. The cross-scale precision motion platform according to claim 6, wherein a third nut is arranged outside the main mass in the motion module, and the motion module is fixedly installed with the optical axis through the third nut. 8. The cross-scale precision motion platform according to claim 4, characterized in that, the two ends of the upper pressing block are correspondingly installed with pre-tightening jackscrews.