超声物料输送的微摩擦驱动力实验研究

Experimental Research on Micro-friction Driving Force of Ultrasonic Vibrating Feeding System

提出一种沿长度方向突变的变截面直梁压电振子结构,该振子能保证输送工作台面上各质点振幅均匀一致。由于振子具有结构对称性,可在空间上实现两个互相垂直的同阶弯曲模态（近似同频）,这两个模态的叠加使工作面上各质点做可更改运动参数的椭圆运动。应用悬臂梁结构研制了一个毫牛量级的微力测试装置,完成输送振子微小摩擦驱动力的测试。对微摩擦驱动力的主要影响因素进行了实验分析。实验结果表明,工作面质点椭圆运动轨迹的长轴在水平面上比在铅垂面上时更有利于物料的超声振动输送。振子振幅增大时,振子对试件的摩擦驱动力也相应增大;当振子两个方向振动的速度相位差从0°~90°增大时,摩擦驱动力呈增大趋势。

A straight beam piezoelectric vibrator structure which has abruptly changed in the longitudinal direction is presented,and this vibrator can insure that all particles on the working surface have the same amplitude.Because of the structure symmetry of vibrator,two same order（approximate same frequency） bending modes which are perpendicular to each other in space can be realized,and the superposition of these two modes can make the particles on the working surface keep elliptical motion whose parameters can be changed.By using the structure of cantilever beam,a micro force testing device whose precision reaches mN level is developed;and after a micro friction driving force test of feeding vibrator,the experimental analysis for the main influence factors of micro friction driving force is studied.The experiment results show that the long axis of the particle＇s elliptical motion in the horizontal plane is better for ultrasonic vibration feeding than in the vertical plane.The friction driving force from vibrator to specimen increases with increasing vibrator amplitude.With the two-direction vibration speed phase difference of vibrator increasing from 0° to 90°,the friction driving force tends to increase.