The Hinged Piezoelectric Stick-slip Bidirectional Driving Mechanism And Experimental Research

Piezoelectric stick-slip drive technology is the main support technology in micro-nano processing,semiconductor manufacturing,precision optics and other fields.At present,the comprehensive control of the friction force in the driving process is seldom realized,which makes the characteristics of large stroke,high precision and high load are difficult to meet at the same time.The few actuators that can realize the comprehensive control of friction force also greatly limit the application range of piezoelectric actuators due to the structural limitations of bidirectional drive.In this paper,a kind of asymmetric flexure hinge mechanism with asymmetric thickness is designed.The axial stiffness of the stator is asymmetrical,and the lateral displacement is generated to drive,which improves the overall output performance of the prototype.On this basis,in order to realize the bidirectional motion of the actuator,the stator with asymmetrical axial stiffness in part but symmetrical structure in whole is designed,so that the actuator has bidirectional motion characteristics and has good bidirectional drive consistency.This paper illustrates the basic theory of piezoelectric stick-slip actuators,and introduces the classification of flexure hinge and the calculation method of excitation deformation of right circular flexible hinges.In this paper,the mathematical model of friction between the stator and the slider is established by using the method of dimensionality reduction(MDR),and the regulation of the frictional force of the asymmetric piezoelectric stick-slip drive is analyzed.Furthermore,this paper takes the maximum lateral displacement as the design goal,taking into account the structural strength and accuracy,and designs a reasonable thickness asymmetric hinge structure through the finite element simulation analysis method.Besides,the related parameters on the maximum lateral displacement and flexible hinge mechanism are also analysed.To illustrate the relationship between the structural strength and precision of asymmetric flexible hinge mechanism,the pseudo rigid-body method on mechanical characteristics analysis of asymmetric flexible hinge mechanism rotating and stretching stiffness mathematical model is adopted.Two prototypes of piezoelectric stick-slip actuators were developed respectively.Finally,the experimental research on output characteristics of the whole machine was carried out by setting up the test system.The experimental results show that the maximum output speed of one-way drive is 15.04 mm /s and the maximum efficiency is 3.66%.The experimental results show that the output performance of the piezoelectric actuator is improved effectively.The maximum output speed of the bidirectional actuator in the positive and negative direction of the x-axis is 10.14 mm /s and 9.99 mm /s,and the positive and negative output performance is very consistent.In addition,the simulation results are in good agreement with the experimental results,and the feasibility of applying MDR method to the stick-slip driver is verified.This paper proposed a design idea that the thicknesses of flexure hinge are asymmetric,and designed the thickness asymmetric type actuator and bidirectional actuator,which broaden the structure of the piezoelectric stick-slip actuator.As for asymmetric types of stick-slip actuator design,this research provides a certain guidance to improve the piezoelectric stick-slip driver output performance and application by the theoretical and experimental support.