阅读说明：本技术 一种抑制粘滑式压电驱动器回退运动的力控装置与方法 (Force control device and method for inhibiting rollback motion of stick-slip piezoelectric actuator ) 是由 黄虎 吴昊 项非凡 冯艺扬 狄琳森 于 2020-06-19 设计创作，主要内容包括：本发明涉及一种抑制粘滑式压电驱动器回退运动的力控装置与方法,属于精密机械领域。装置包括驱动单元、预紧力调整单元和基座。装置的驱动单元和预紧力调控单元分别通过螺钉与基座连接。通过旋转预紧力调整单元中水平微动调整机构的旋钮,可以调整圆弧形铰链与导轨之间的预紧力。通过旋转驱动单元中水平微动调整机构的旋钮,可以调整杆形铰链与导轨之间的初始间隙。在特定的预紧力作用下,当驱动单元中压电叠堆的驱动电压快速下降时,预紧力调整单元中圆弧形铰链由于预紧力作用产生的摩擦力平衡了驱动单元引起回退运动的摩擦力,从而抑制压电驱动器的回退运动,提高粘滑式压电驱动器步进运动的平稳性。(The invention relates to a force control device and method for inhibiting rollback motion of a stick-slip piezoelectric actuator, and belongs to the field of precision machinery. The device comprises a driving unit, a pretightening force adjusting unit and a base. The driving unit and the pretightening force regulating and controlling unit of the device are respectively connected with the base through screws. The pre-tightening force between the circular arc hinge and the guide rail can be adjusted by rotating a knob of a horizontal micro-motion adjusting mechanism in the pre-tightening force adjusting unit. By rotating the knob of the horizontal fine adjustment mechanism in the drive unit, the initial gap between the rod-shaped hinge and the guide rail can be adjusted. Under the action of a specific pretightening force, when the driving voltage of the piezoelectric stack in the driving unit is rapidly reduced, the friction force generated by the arc-shaped hinge in the pretightening force adjusting unit due to the action of the pretightening force balances the friction force of the driving unit for causing the backspacing motion, so that the backspacing motion of the piezoelectric driver is inhibited, and the stability of the stepping motion of the stick-slip piezoelectric driver is improved.)

1. A force control device for restraining the backspacing motion of a stick-slip piezoelectric actuator is characterized in that: the device comprises a base (1), a driving unit and a pretightening force adjusting unit, wherein the driving unit and the pretightening force adjusting unit are respectively connected with the base (1) through screws; the driving unit comprises a guide rail sliding block fixed end (2), a sliding block (3), a guide rail (4), a piezoelectric stack (5), a wedge-shaped block (6), a rod-shaped hinge (7) and a horizontal micro-motion adjusting mechanism (8), wherein the piezoelectric stack (5) is arranged in a groove of the rod-shaped hinge (7) in an interference fit mode by adjusting the wedge-shaped block (6), the rod-shaped hinge (7) is connected with the upper end face of the horizontal micro-motion adjusting mechanism (8) through a screw, an initial gap between the rod-shaped hinge (7) and the guide rail (4) in the driving unit is adjusted by rotating a knob of the horizontal micro-motion adjusting mechanism (8), the sliding block (3) is connected with the guide rail sliding block fixed end (2) through the screw, and the guide rail (4) can move horizontally along the direction of the sliding;

the pretightening force adjusting unit mainly comprises an arc-shaped hinge (9) and a horizontal micro-motion adjusting mechanism (10), the arc-shaped hinge (9) is connected with the upper end face of the horizontal micro-motion adjusting mechanism (10) through a screw, the horizontal micro-motion adjusting mechanism (10) is connected with the upper end face of the base (1) through a screw, and pretightening force between the arc-shaped hinge (9) and the guide rail (4) is adjusted by rotating a knob of the horizontal micro-motion adjusting mechanism (10).

2. A force control method for realizing the back motion suppression of a stick-slip piezoelectric actuator by using the device of claim 1, wherein the force control method comprises the following steps: based on the inverse piezoelectric effect, the piezoelectric stack (5) can drive the rod-shaped hinge (7) to stretch and retract under the driving voltage so as to drive the guide rail (4) to move; in the driver, the pretightening force and the initial gap can be adjusted by the specific structures of the pretightening force adjusting unit and the driving unit, so that the backspacing motion of the stick-slip piezoelectric driver is effectively inhibited; before driving, the pre-tightening force between the circular arc-shaped hinge (9) and the guide rail (4) can be adjusted by rotating a knob of a horizontal micro-motion adjusting mechanism (10) in the pre-tightening force adjusting unit, and the initial gap between the rod-shaped hinge (7) and the guide rail (4) can be adjusted by rotating a knob of a horizontal micro-motion adjusting mechanism (8) in the driving unit; during the driving process, the friction force F between the circular arc-shaped hinge (9) and the guide rail (4)_pLess than the friction force F between the rod-shaped hinge (7) and the guide rail (4)_f(ii) a When the driving voltage is rapidly reduced, a reverse frictional force occurs between the rod-shaped hinge (7) and the guide rail (4)The guide rail (4) is pushed to move backwards, and meanwhile, the circular arc hinge (9) and the guide rail (4) have relative movement tendency, and forward friction force F 'is generated'_p(ii) a When the friction is reversedFriction with the forward directionF′_pWhen the phase is balanced, the backspacing motion of the driver can be effectively inhibited.

3. The force control method according to claim 2, wherein the preload adjustment unit adjusts the frictional force F 'by adjusting the preload'_pAnd the back movement of the stick-slip piezoelectric actuator is inhibited.

Technical Field

The invention relates to the field of precision machinery, in particular to a force control device and a method for inhibiting rollback motion of a stick-slip piezoelectric actuator.

Background

The piezoelectric driver is a mechanical device manufactured by utilizing a piezoelectric driving technology, and the basic principle of the piezoelectric driver is to control mechanical deformation to generate rotation or linear motion based on the inverse piezoelectric effect of a piezoelectric ceramic material. The piezoelectric actuator has the advantages of high response speed, large output force, simple structure and small volume, and is widely applied to the advanced scientific fields of precision/ultra-precision machining, micromachines, biomedical engineering and the like.

The drivers reported so far all have different degrees of defects. Although the inchworm bionic piezoelectric actuator has the advantages of large output force, high resolution, small rollback motion and the like, the inchworm bionic piezoelectric actuator is complex in structure, difficult in component assembly and relatively complex in control process. Although the parasitic motion type piezoelectric driver, the inertial type piezoelectric driver and the stick-slip type piezoelectric driver have simple structures, easy assembly and convenient control, the parasitic motion type piezoelectric driver, the inertial type piezoelectric driver and the stick-slip type piezoelectric driver have low bearing capacity, poor self-locking performance and relatively serious rollback phenomenon, and are difficult to ensure the stability of motion. Therefore, how to solve the problem of rollback in the piezoelectric actuator, thereby improving the output performance and expanding the application prospect of the piezoelectric actuator is a problem which needs to be solved urgently.

From the mechanical angle, the pre-tightening force is applied to the guide rail through the pre-tightening force regulating unit, so that the output performance of the stick-slip piezoelectric driver is regulated, the backspacing motion of the stick-slip piezoelectric driver is eliminated, and the self-locking performance of the stick-slip piezoelectric driver is enhanced. The invention eliminates the backspacing movement, improves the output performance, inherits the advantages of simple structure, easy assembly and convenient control of the stick-slip piezoelectric driver, enhances the application prospect of the stick-slip piezoelectric driver in the fields of precision machinery, equipment and the like, and has important practical value.

Disclosure of Invention

The invention aims to provide a force control device and a method for restraining the rollback motion of a stick-slip piezoelectric actuator, which can effectively restrain the rollback motion of the stick-slip piezoelectric actuator. The pre-tightening force between the circular arc hinge and the guide rail can be adjusted by rotating a knob of a horizontal micro-motion adjusting mechanism in the pre-tightening force adjusting unit. By rotating the knob of the horizontal fine adjustment mechanism in the drive unit, the initial gap between the rod-shaped hinge and the guide rail can be adjusted. Under the action of a specific pretightening force, when the driving voltage of the piezoelectric stack in the driving unit is rapidly reduced, the friction force generated by the arc-shaped hinge in the pretightening force adjusting unit due to the action of the pretightening force balances the friction force of the driving unit for causing the rollback movement, so that the rollback movement of the piezoelectric driver is remarkably inhibited, and the stability of the step movement of the stick-slip piezoelectric driver is improved. The invention provides a novel device and a novel method for inhibiting the backspacing motion of the stick-slip piezoelectric driver, can be expanded and applied to the piezoelectric drivers with other principles, and has wide application range and strong practicability.

The above object of the present invention is achieved by the following technical solutions:

the force control device for inhibiting the rollback motion of the stick-slip piezoelectric actuator comprises a driving unit, a pretightening force adjusting unit and a base (1), wherein the driving unit and the pretightening force adjusting unit are respectively connected with the base (1) through screws. Drive unit constitute by guide rail slider stiff end (2), slider (3), guide rail (4), piezoelectric stack (5), wedge (6), pole shape hinge (7) and horizontal fine motion guiding mechanism (8), piezoelectric stack (5) adopt interference fit's mode to install in the recess of pole shape hinge (7) through adjustment wedge (6), pole shape hinge (7) are connected with the up end of horizontal fine motion guiding mechanism (8) through the screw, adjust the initial clearance between pole shape hinge (7) and guide rail (4) in to drive unit through the knob of rotatory horizontal fine motion guiding mechanism (8), slider (3) are connected with guide rail slider stiff end (2) through the screw, horizontal migration can be carried out along the direction of slider in guide rail (4).

The pretightening force adjusting unit mainly comprises an arc-shaped hinge (9) and a horizontal micro-motion adjusting mechanism (10), the arc-shaped hinge (9) is connected with the upper end face of the horizontal micro-motion adjusting mechanism (10) through a screw, the horizontal micro-motion adjusting mechanism (10) is connected with the upper end face of the base (1) through a screw, and pretightening force between the arc-shaped hinge (9) and the guide rail (4) is adjusted by rotating a knob of the horizontal micro-motion adjusting mechanism (10).

The invention provides a stick-slip inhibiting piezoelectric driverThe force control method of the device retraction movement is based on the inverse piezoelectric effect, and the piezoelectric stack (5) can drive the rod-shaped hinge (7) to stretch and contract under the driving voltage so as to drive the guide rail (4) to move. The specific structures of the pretightening force adjusting unit and the driving unit in the actuator can effectively inhibit the backspacing motion of the stick-slip piezoelectric actuator through the adjustment of the pretightening force and the initial clearance. Before driving, the pre-tightening force between the circular arc-shaped hinge (9) and the guide rail (4) can be adjusted by rotating a knob of a horizontal micro-motion adjusting mechanism (10) in the pre-tightening force adjusting unit, and the initial gap between the rod-shaped hinge (7) and the guide rail (4) can be adjusted by rotating a knob of a horizontal micro-motion adjusting mechanism (8) in the driving unit. During the driving process, the friction force F between the circular arc-shaped hinge (9) and the guide rail (4)_pLess than the friction force F between the rod-shaped hinge (7) and the guide rail (4)_f(ii) a When the driving voltage is reduced rapidly, a reverse friction force occurs between the rod-shaped hinge (7) and the guide rail (4)

The trend of pushing the guide rail (4) to move backwards is generated; at the same time, the circular arc hinge (9) and the guide rail (4) tend to move relatively to each other, and a forward friction force F 'is generated'_p(ii) a When the friction is reversedWith forward frictional force F'_pWhen the phase is balanced, the backspacing motion of the driver can be effectively inhibited.

The pre-tightening force adjusting unit adjusts and controls the friction force F 'by adjusting pre-tightening force'_pAnd the back movement of the stick-slip piezoelectric actuator is inhibited.

The invention has the advantages that: friction force F 'is regulated and controlled by applying pretightening force through pretightening force adjusting unit'_pThe device and the method are simple, and the operation process is flexible and convenient. In addition, the invention can be expanded to be applied to piezoelectric drivers with other principles, and has wide application range and strong practicability.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention.

Fig. 1 is a schematic structural diagram of a force control device for suppressing a rollback motion of a stick-slip piezoelectric actuator according to the present invention.

FIG. 2 is a top view of the rod-shaped hinge of the present invention.

Fig. 3 is a top view of the circular arc hinge of the present invention.

Fig. 4 is a force diagram of the rod-shaped hinge of the present invention before driving.

Fig. 5 is a force principle diagram of the guide rail of the invention in the whole driving process.

In the figure: 1. a base; 2. a fixed end of the guide rail sliding block; 3. a slider; 4. a guide rail; 5. a piezoelectric stack; 6. a wedge block; 7. a rod-shaped hinge; 8. a horizontal micro-motion adjusting mechanism; 9. a circular arc shaped hinge; 10. horizontal fine motion adjustment mechanism.

Detailed Description

The details and embodiments of the present invention are further described below with reference to the accompanying drawings.

Referring to fig. 1, the force control device for inhibiting the rollback motion of the stick-slip piezoelectric actuator of the invention comprises a driving unit, a pretightening force adjusting unit and a base (1), wherein the driving unit and the pretightening force adjusting unit are respectively connected with the base (1) through screws. Drive unit constitute by guide rail slider stiff end (2), slider (3), guide rail (4), piezoelectric stack (5), wedge (6), pole shape hinge (7) and horizontal fine motion guiding mechanism (8), piezoelectric stack (5) adopt interference fit's mode to install in the recess of pole shape hinge (7) through adjustment wedge (6), pole shape hinge (7) are connected with the up end of horizontal fine motion guiding mechanism (8) through the screw, the knob of rotatory horizontal fine motion guiding mechanism (8), adjust the initial clearance between pole shape hinge (7) and guide rail (4) in the drive unit, slider (3) are connected with guide rail slider stiff end (2) through the screw, horizontal migration can be carried out along the direction of slider in guide rail (4).

The pretightening force adjusting unit mainly comprises an arc-shaped hinge (9) and a horizontal micro-motion adjusting mechanism (10), the arc-shaped hinge (9) is connected with the upper end face of the horizontal micro-motion adjusting mechanism (10) through a screw, the horizontal micro-motion adjusting mechanism (10) is connected with the upper end face of the base (1) through a screw, and the pretightening force between the arc-shaped hinge (9) and the guide rail (4) is adjusted by rotating a knob of the horizontal micro-motion adjusting mechanism (10).

Referring to fig. 2 to 3, the stick-slip piezoelectric actuator of the present invention has the advantages of large stroke and no electromagnetic interference, but has a significant rollback phenomenon when the driving power supply drops rapidly. Therefore, the invention restrains the back-off movement of the stick-slip piezoelectric driver during working through the pretightening force adjusting unit, and improves the overall output performance of the driver.

The pre-tightening force adjusting unit inhibits the back-off motion of the stick-slip piezoelectric driver through the adjustment of the pre-tightening force, and improves the stability of the stepping motion of the stick-slip piezoelectric driver.

Referring to fig. 4 to 5, the stress diagram of the whole process of the driver operation in the present invention is shown. The complete movement process is summarized as follows, and mainly comprises three stages:

stage 1: referring to a part a in fig. 4 to 5, before the driver is driven, the pretightening force between the circular arc-shaped hinge (9) and the guide rail (4) can be adjusted by rotating a knob of a horizontal micro-motion adjusting mechanism (10) in the pretightening force adjusting unit; by rotating the knob of the horizontal fine adjustment mechanism (8) in the drive unit, the initial clearance between the rod-shaped hinge (7) and the guide rail (4) can be adjusted. The process ensures that the guide rail can still normally work after the pretightening force is applied, namely the friction force F between the circular arc hinge (9) and the guide rail (4)_pLess than the friction force F between the rod-shaped hinge (7) and the guide rail (4)_f。

And (2) stage: referring to the part b in fig. 5, the friction force F between the circular arc-shaped hinge (9) and the guide rail (4) is still satisfied during the driving process of the driver_pLess than the friction force F between the rod-shaped hinge (7) and the guide rail (4)_fThe friction force at this time is no longer the product of the positive pressure and the static friction factor, but becomes the product of the positive pressure and the dynamic friction factor; at this time, at the driverThe guide rail is displaced forward in the horizontal direction by S.

And (3) stage: referring to portions c and d in fig. 5, when the driving power is rapidly lowered, a reverse frictional force occurs between the bar-shaped hinge (7) and the guide rail (4)

Has the tendency of pushing the guide rail (4) to move backwards, and generates a displacement S backwards in the horizontal direction₀(ii) a Meanwhile, the pretightening force between the circular arc hinge (9) and the guide rail (4) is subjected to a backward movement trend to generate a forward friction force F'_pThereby pushing the guide rail (4) to move forwards; when the friction is reversedWith forward frictional force F'_pWhen the phase is balanced, the total forward horizontal displacement is generated, and is Delta S-S₀The rollback phenomenon of the driver is effectively suppressed.

The above description is only a preferred example of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like of the present invention shall be included in the protection scope of the present invention.