CN107834896A - Pre- frictional force regulates and controls the apparatus and method of parasitic principle piezoelectric actuator output performance - Google Patents

Abstract

The invention relates to a device and method for regulating the output performance of a parasitic principle piezoelectric driver by a pre-friction force, belonging to the field of precision machinery. The device comprises a base, a driving unit, and a pre-friction control unit. The drive unit is connected to the base through a claw pad, and the pre-friction control unit is connected to the base through a friction pad. By adjusting the pre-tightening screw, the friction force during the movement of the mover is changed, so as to regulate the output performance of the piezoelectric actuator based on the parasitic principle, and realize the improvement of the self-locking of the piezoelectric actuator when the driving voltage is zero and the suppression of the retreat during the movement process. The double effect of the phenomenon. The advantages are: simple structure, convenient control, through the pre-friction force, the self-locking performance of the piezoelectric actuator can be enhanced when the driving voltage is zero, and the retreat phenomenon during the motion can be effectively suppressed, thereby improving the output performance of the piezoelectric actuator , to enhance its application in ultra-precision machining, assembly, precision measurement technology, precision optics, biomedical engineering and other fields.

Description

Device and method for adjusting output performance of parasitic principle piezoelectric actuator by pre-friction force

technical field

The invention relates to the field of precision machinery, in particular to a device and method for regulating the output performance of a parasitic principle piezoelectric driver by pre-friction force. By applying pre-friction force, the output performance of piezoelectric actuators widely used in precision positioning, precision machining, precision clamping, micromanipulation and other fields can be effectively regulated to reduce or even eliminate its retraction motion and enhance its self-efficacy. Locking to expand its application fields and applicable occasions.

Background technique

Due to the advantages of high positioning accuracy, fast frequency response, low energy consumption, light weight, and small size, piezoelectric actuators play an increasingly important role in the fields of precision machinery and nanotechnology, and are widely used in ultra-precision machining, assembly, Among many cutting-edge scientific fields such as precision measurement technology, precision optics, and biomedical engineering.

At present, several typical driving principles such as inchworm bionic drive, stick-slip drive, inertial drive, and parasitic motion drive have been applied to the development of piezoelectric actuators with large stroke output capabilities. Among them, stick-slip, inertial, and parasitic principle piezoelectric actuators have the advantages of simple structure, easy processing and assembly, simple control system, and fast stepping speed compared with inchworm piezoelectric actuators, so they have very broad application prospects, but Its displacement output curve often has problems such as nonlinearity, backlash, and poor self-locking when the driving voltage is zero, which affects its output performance and applicable occasions, and brings difficulties to its precise positioning and control. For example, the document "Design Analysis and Experimental Research of Stick-slip Inertial Piezoelectric Precision Actuator" proposed a new structure of stick-slip inertial piezoelectric actuator, designed a closed-loop control system, and verified through experiments that the drive can complete higher precision. Positioning, but it can be found from the displacement curve that there will be a relatively serious retraction movement during the driving process, and the driver does not have a special design in terms of self-locking, it is difficult to guarantee the movement when it is subjected to an external force during the driving process Stability, both aspects can negatively affect the use and control of such high-precision drives. The literature "Modeling of piezoelectric-driven stick–slip actuators" designed a linear actuator based on the stick-slip principle. This design can drive more accurately, but it lacks self-locking design, and it can also be seen from the experimental results that the stick-slip actuator The retraction movement of the piezoelectric actuator is also very pronounced. The document "A novel driving principle by means of the parasitic motion of the microgripper and its preliminary application in the design of the linear actuator" presents a novel parasitic motion principle piezoelectric actuator, which achieves a higher positioning resolution. However, from It can also be seen from the displacement output curve that the piezoelectric actuator based on the principle of parasitic motion also has significant back-off and nonlinear phenomena, and its self-locking property is poor. In summary, it can be seen that although stick-slip, inertial, parasitic motion and other driving methods have many advantages compared with the inchworm type, they have problems in self-locking, and the regression and nonlinear phenomena on the displacement output curve generally exist in the Various principles of piezoelectric actuators. Therefore, how to reduce or even eliminate the retreat phenomenon during the motion of the piezoelectric actuator and improve the self-locking performance of the piezoelectric actuator when the driving voltage is zero is still a difficult point and a problem that needs to be solved urgently.

Contents of the invention

The purpose of the present invention is to provide a device and method for adjusting the output performance of a parasitic principle piezoelectric actuator by pre-friction force, which solves the above-mentioned problems in the prior art, by applying a pre-friction force for precision positioning, precision machining, precision The output performance of piezoelectric actuators widely used in clamping, micromanipulation and other fields can be effectively regulated to reduce or even eliminate their retraction motion and enhance their self-locking properties, so as to expand the application range and fields of piezoelectric actuators.

Above-mentioned purpose of the present invention is achieved through the following technical solutions:

A device for adjusting the output performance of a piezoelectric driver based on the pre-friction force, including a base, a drive unit, and a pre-friction force control unit. It is connected with the base 1 through the friction pad 2.

The drive unit includes a flexible hinge gripper 7, a piezoelectric stack 8, a gripper pad 9, a guide rail 10, a slider 11, and a mover 12. The flexible hinge gripper 7 connects to the base through the gripper pad 9 The seat 1 is connected with each other, the gripper pad 9 is installed on the base 1 by screws, the piezoelectric stack 8 is installed in the groove of the flexible hinge gripper 7 in a tight fit, and the guide rail 10 is connected to the base by countersunk screws 1, the mover 12 is connected to the upper end of the slider 11 by screws, and moves in the x -axis direction on the guide rail 10 through the slider 11.

The pre-friction control unit is divided into two parts, left and right, and the two parts are identical in composition, including friction pads 2, flexible hinge pressure rods 3, positioning rods 4, pre-tightening screws 5, strain gauge groups 6, left Strain gauge signal conditioning module 13, right strain gauge signal conditioning module 14, data acquisition card 15, industrial computer and display 16, the flexible hinge pressure rod 3 and positioning rod 4 are installed on the friction pad 2 by screws and connected to the base 1 phase connection, the gap between the flexible hinge pressure rod 3 and the positioning rod 4 is 3mm; the pre-tightening screw 5 is installed on the positioning rod 4, and the tail is in contact with the flexible hinge pressure rod 3, and the flexible hinge pressure rod is changed by turning the pre-tightening screw 5 3 The pressure on the mover 12 of the drive unit, and then change the friction force when the mover 12 moves; the strain gauge group 6 is pasted on the weak link of the front groove of the flexible hinge pressure rod 3, and the data acquisition card 15 and the left strain gauge signal The conditioning module 13 and the right strain gauge signal conditioning module 14 are connected by wires, and the output analog signals are converted into digital signals and collected to the industrial computer and the display 16 .

Another object of the present invention is to provide a method for regulating the output performance of a parasitic principle piezoelectric actuator by pre-friction force, comprising the following steps:

a) The piezoelectric stack 8 is installed in the groove of the flexible hinge gripper 7 in a tight fit manner. After the flexible hinge gripper 7 and the collet of the mover 12 are well matched, the flexible hinge gripper 7 is installed on the The upper end of the claw pad 9 is connected with the data acquisition card 15, the left strain gauge signal conditioning module 13, the right strain gauge signal conditioning module 14, and the industrial computer and the display 16 through wires;

b) Adjust the pre-tightening screw 5, observe the display of the industrial computer and the display 16, so that the flexible hinge pressure rods 3 on the left and right sides exert pressure on the mover 12, so that when the flexible hinge gripper 7 pulls the mover 12 to move, the left and right A frictional force hindering the movement of the mover 12 will be generated between the flexible hinge pressure rods 3 on both sides and the mover 12;

c) Apply a driving voltage to the piezoelectric stack 8. Due to the inverse piezoelectric effect, the piezoelectric stack 8 elongates at this time, driving the flexible hinge gripper 7 to deform, so that the flexible hinge gripper 7 claws and the mover 12 Chuck contact, under the principle of parasitic motion, the mover 12 is pulled to move along the guide rail 10; during the pulling process, due to the existence of friction, the mover 12 is self-locked when the driving voltage of the piezoelectric stack 8 is zero The performance has been greatly enhanced, and the inherent retraction motion of the parasitic principle piezoelectric actuator has been greatly suppressed, so as to achieve the double effect of improving the self-locking and motion accuracy of the parasitic principle piezoelectric actuator;

d) By adjusting the pre-tightening screw 5, change the pressure exerted by the flexible hinge pressure rods 3 on the left and right sides on the mover 12, that is, change the friction force when the mover moves, so as to improve the output performance of the piezoelectric actuator based on the parasitic principle through the friction force To regulate.

The beneficial effects of the present invention are: simple structure, convenient control, through the pre-friction force loading and regulating device and method provided by the present invention, the self-locking property of the piezoelectric actuator can be enhanced when the driving voltage is zero, and the Eliminate the inherent retraction motion of the piezoelectric actuator based on the parasitic principle, and achieve the double effect of improving the self-locking and motion accuracy of the piezoelectric actuator, thereby expanding its application in ultra-precision machining, assembly, precision measurement technology, precision optics, biomedical engineering, and many other frontiers applications in the scientific field. The device and method provided by the invention can be expanded and applied to piezoelectric drivers of other principles, and have wide application range and strong practicability.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention, and constitute a part of the application. The schematic examples and descriptions of the present invention are used to explain the present invention, and do not constitute improper limitations to the present invention.

Fig. 1 is the device structure schematic diagram of the output performance of the piezoelectric driver of the pre-friction regulation and control parasitic principle of the present invention;

Fig. 2 is a top view schematic diagram of the flexible hinge gripper of the present invention;

Fig. 3 is a principle diagram of deformation of the flexible hinge gripper of the present invention;

Fig. 4 is the working principle diagram of the pre-friction regulating unit of the present invention;

Fig. 5 is a schematic diagram of data collection, processing and display in the present invention.

In the figure: 1. Base; 2. Friction pad; 3. Flexible hinge pressure rod; 4. Positioning rod; 5. Preload screw; 6. Strain gauge group; 7. Flexible hinge gripper; Stack; 9. Gripper block; 10. Guide rail; 11. Slider; 12. Mover; 13. Left strain gauge signal conditioning module; 14. Right strain gauge signal conditioning module; 15. Data acquisition card; 16. Industrial control machine and display.

Detailed ways

The detailed content of the present invention and its specific implementation will be further described below in conjunction with the accompanying drawings.

Referring to Fig. 1 to Fig. 5, the device and method for adjusting the output performance of the parasitic principle piezoelectric actuator by the pre-friction force of the present invention can solve the problems of the parasitic principle piezoelectric actuator in terms of retraction and self-locking through the pre-friction force, In order to improve its output performance and expand its application range and field. The structure is simple and the control is convenient. Through the pre-friction force, the self-locking property of the piezoelectric actuator can be enhanced when the driving voltage is zero, and the backlash phenomenon during the motion can be effectively suppressed, thereby improving the output performance of the piezoelectric actuator and enhancing its Applications in ultra-precision machining, assembly, precision measurement technology, precision optics, biomedical engineering and other fields. The device for regulating the output performance of the piezoelectric driver based on the parasitic principle of the pre-friction force includes a base, a drive unit, and a pre-friction force control unit. The control unit is connected with the base 1 through the friction pad 2 .

The drive unit mainly includes a flexible hinge gripper 7, a piezoelectric stack 8, a gripper pad 9, a guide rail 10, a slider 11, and a mover 12. The flexible hinge gripper 7 is connected to the gripper pad 9 and The base 1 is connected with each other, the grip pad 9 is installed on the base 1 through screws, the piezoelectric stack 8 is installed in the groove of the flexible hinge gripper 7 in a tight fit, and the guide rail 10 is connected to the base through countersunk screws. On the base 1, the mover 12 is connected to the upper end of the slider 11 by screws, and can move in the x -axis direction on the guide rail 10 through the slider 11.

The pre-friction control unit is divided into two parts, left and right, and the two parts are identical in composition, mainly including friction pads 2, flexible hinge pressure rods 3, positioning rods 4, pre-tightening screws 5, strain gauge groups 6, The left strain gauge signal conditioning module 13, the right strain gauge signal conditioning module 14, the data acquisition card 15, the industrial computer and the display 16, the flexible hinge pressure rod 3 and the positioning rod 4 are installed on the friction pad 2 by screws and connected to the base The seat 1 is connected, the gap between the flexible hinge pressure rod 3 and the positioning rod 4 is 3 mm, the pre-tightening screw 5 is installed on the positioning rod 4, and the tail part is in contact with the flexible hinge pressure rod 3, so that it can be changed by turning the pre-tightening screw 5 The pressure of the flexible hinge pressure rod 3 on the mover 12 changes the friction force of the mover 12 when it moves. The strain gauge group 6 is pasted on the weak link of the front groove of the flexible hinge pressure rod 3 by 502 glue. The data acquisition card 15 It is connected with the left strain gauge signal conditioning module 13 and the right strain gauge signal conditioning module 14 through wires, and the output analog signal is converted into a digital signal and collected to the industrial computer and the display 16 .

Referring to Fig. 3 to Fig. 5, the method for adjusting the output performance of the parasitic principle piezoelectric actuator by the pre-friction force of the present invention changes the pressure exerted by the left and right flexible hinge pressure rods on the mover by adjusting the pre-tightening screw, that is, changes the movement of the mover Therefore, the output performance of the parasitic principle piezoelectric actuator can be regulated through the friction force, and the double effect of improving the self-locking of the piezoelectric actuator when the driving voltage is zero and suppressing the retreat phenomenon during the movement is realized. Specific steps are as follows:

a) The piezoelectric stack 8 is installed in the groove of the flexible hinge gripper 7 in a tight fit manner. After the flexible hinge gripper 7 and the collet of the mover 12 are well matched, the flexible hinge gripper 7 is installed on the The upper end of the claw pad 9 is connected with the data acquisition card 15, the left strain gauge signal conditioning module 13, the right strain gauge signal conditioning module 14, and the industrial computer and the display 16 through wires;

b) Adjust the pre-tightening screw 5 so that the flexible hinge pressure rods 3 on the left and right sides are under the pressure F _LD , observe the display of the industrial computer and the display 16, and make the flexible hinge pressure rods 3 on the left and right sides exert an appropriate force on the mover 12 Pressure F _N (such as 2N), so that when the flexible hinge gripper 7 pulls the mover 12 to move, the friction force f _N that hinders the mover 12 will be generated between the flexible hinge pressure rod 3 on the left and right sides and the mover 12;

c) Apply a driving voltage to the piezoelectric stack 8. Due to the inverse piezoelectric effect, the piezoelectric stack 8 elongates and generates a displacement x _pzt , which drives the flexible hinge gripper 7 to deform. After two-stage structure amplification, the flexible hinge grasps The claw part A of the claw 7 produces a displacement x _a in the x direction and a displacement y _a in the y direction, so that the claw part of the flexible hinge claw 7 is in contact with the collet of the mover 12, and the mover 12 is pulled along the guide rail 10 under the principle of parasitic motion to move. During the pulling process, due to the existence of friction force, the self-locking property of the mover 12 is greatly enhanced when the driving voltage of the piezoelectric stack 8 is zero, and the inherent retraction motion of the piezoelectric actuator based on the parasitic principle is generated. Significant suppression, so as to achieve the double effect of improving the self-locking and motion accuracy of the piezoelectric actuator based on the parasitic principle.

d) By adjusting the pre-tightening screw 5, change the pressure exerted by the flexible hinge pressure rods 3 on the left and right sides on the mover 12, that is, change the friction force when the mover moves, so as to improve the output performance of the piezoelectric actuator based on the parasitic principle through the friction force To regulate.

The above descriptions are only preferred examples of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made to the present invention shall be included within the protection scope of the present invention.

Claims (4)

1. a kind of pre- frictional force regulates and controls the device of parasitic principle piezoelectric actuator output performance, it is characterised in that：Including pedestal, drive Moving cell, pre- frictional force regulation and control unit, the driver element pass through gripper cushion block（9）And screw and pedestal（1）Connection, pre- friction Power regulation and control unit passes through friction pad（2）With pedestal（1）Connection.

2. pre- frictional force according to claim 1 regulates and controls the device of parasitic principle piezoelectric actuator output performance, its feature It is：Described driver element includes flexible hinge gripper（7）, piezoelectric stack（8）, gripper cushion block（9）, guide rail（10）, sliding block （11）, mover（12）, the flexible hinge gripper（7）Pass through gripper cushion block（9）With pedestal（1）It is connected, gripper cushion block（9）It is logical Cross screw and be arranged on pedestal（1）On, piezoelectric stack（8）Flexible hinge gripper is arranged on using tight fit mode（7）Groove in, Guide rail（10）Pedestal is connected to by sunk screw（1）On, mover（12）It is connected by screw in sliding block（11）Upper end, pass through Sliding block（11）In guide rail（10）On doxThe movement of direction of principal axis.

3. pre- frictional force according to claim 1 regulates and controls the device of parasitic principle piezoelectric actuator output performance, its feature It is：Described pre- frictional force regulation and control unit is divided into left and right two parts composition, and two parts composition is identical, including friction pad Block（2）, flexible hinge depression bar（3）, locating rod（4）, pre-loading screw（5）, foil gauge group（6）, left foil gauge Signal-regulated kinase （13）, right foil gauge Signal-regulated kinase（14）, data collecting card（15）, industrial computer and display（16）, the flexible hinge Depression bar（3）, locating rod（4）Friction pad is arranged on by screw（2）Upper and and pedestal（1）It is connected, flexible hinge depression bar（3） With locating rod（4）Gap is 3mm；Pre-loading screw（5）Installed in locating rod（4）On, afterbody and flexible hinge depression bar（3）Connect Touch, by twisting pre-loading screw（5）Change flexible hinge depression bar（3）To the mover of driver element（12）Pressure, and then change Mover（12）Frictional force during motion；Foil gauge group（6）It is pasted onto flexible hinge depression bar（3）Front end groove weak link at, Data collecting card（15）With left foil gauge Signal-regulated kinase（13）With right foil gauge Signal-regulated kinase（14）Connected by wire Connect, the analog signal output it is converted into digital signal acquiring to industrial computer and display（16）.

4. a kind of method that pre- frictional force regulates and controls parasitic principle piezoelectric actuator output performance, it is characterised in that：Including following step Suddenly：

a）By piezoelectric stack（8）Flexible hinge gripper is arranged on using tight fit mode（7）Groove in, in flexible hinge gripper （7）With mover（12）After chuck is worked good, by flexible hinge gripper（7）Gripper cushion block is arranged on by screw（9）Upper end, By data collecting card（15）With left foil gauge Signal-regulated kinase（13）With right foil gauge Signal-regulated kinase（14）And industry control Machine and display（16）Connected by wire；

b）Adjust pre-loading screw（5）, observe industrial computer and display（16）Registration, make the left and right sides flexible hinge depression bar （3）To mover（12）Apply pressure, so as in flexible hinge gripper（7）Pull mover（12）During motion, the flexibility of the left and right sides Hinge depression bar（3）With mover（12）Between can produce obstruction mover（12）The frictional force of motion；

c）To piezoelectric stack（8）Apply driving voltage, due to inverse piezoelectric effect, now piezoelectric stack（8）Elongation, drive flexible hinge Chain gripper（7）It is deformed so that flexible hinge gripper（7）Claw and mover（12）Chuck contact, in parasitic motion principle Under, pull mover（12）Along guide rail（10）Move；In drawing process, due to the presence of frictional force, make mover（12） In piezoelectric stack（8）Self-locking performance when driving voltage is zero has great enhancing, and parasitic principle piezoelectric actuator is consolidated Some rollback motions, which produce, significantly to be suppressed, so as to realize the self-locking performance and kinematic accuracy that improve parasitic principle piezoelectric actuator Double effectses；

d）By adjusting pre-loading screw（5）, change the left and right sides flexible hinge depression bar（3）To mover（12）The pressure of application, Change frictional force during mover motion, so as to be adjusted by frictional force to parasitic principle piezoelectric actuator output performance Control.