压电式喷射点胶控制系统的电路设计

The Circuit Design of Piezoelectric Jetting Dispensing Control System

基于新型压电式点胶头采用的双压电陶瓷的推挽驱动作为胶体喷射的作用机制,设计并搭建了压电式喷射点胶控制系统,完成了硬件与软件模块的组装调试,实现对下压电陶瓷信号的频率、占空比、幅值、上压电陶瓷信号幅值的连续可调,具备人机交互、清洗、喷射点数可调等功能。经测试,系统各参数达到预定指标,频率显示误差:±1.2 Hz;占空比显示误差:±1%;幅值显示误差:±8 mV。在驱动方波电压200 V、频率65 Hz、占空比20%、喷嘴直径250μm、供料压力4 bar、喷射高度3.5 mm的条件下,得到平均直径为1.07 mm左右的喷射胶滴,一致性误差为±2%。

According to the working principle of newly piezoelectric dispensing head,which using the pushed driving of double piezoelectric ceramic for colloform jetting,we design and establish this piezoelectric jetting dispensing control system.Meanwhile,package the hardware and debug the software,achieve the goal that frequency,duty cycle and amplitude of the lower piezoelectric ceramic signal,amplitude of the upper piezoelectric ceramic signal can be continuously adjusted.The system has the function of man-machine interaction,cleaning,regulating injection points,and so on.After tested,all of the system parameters can meet the presupposed index,with the frequency display error： ±1.2 Hz,duty cycle display error： ±1%,amplitude display error： ±8 mV.Under the condition that voltage of the driving squarewave 200 V,frequency 65 Hz,duty cycle 20%,diameter of nozzle 250 μm,pressure 4 bar,height of jetting 3.5 mm,we get the jetting drops with an average diameter of 1.07 mm,and its conformity error ±2%.