压电作动器驱动两级电液比例减压阀设计分析

针对以往采用压电作动器的减压阀必须采用压力传感器的不足，提出一种先导式比例减压阀.该阀采用压电作动器控制先导阀阀口开度，与先导供油器的固定节流孔形成分压作用，实现对先导压力的控制，进而控制主阀实现对主阀出口压力控制.对减压阀进行结构和原理分析，建立数学模型; 用Simulink仿真分析结构参数对静动态特性的影响.采用调零弹簧将最低可控压力向下扩展到0;设计三台肩式阀芯结构，通过流场分析验证了该结构有效地减小液动力; 根据仿真结果选择恰当的反馈阻尼孔尺寸，保证减压阀的动态特性.所设计的减压阀无须测量压力并闭环即可实现减压功能，具有良好的调压范围、调压精度，能实现快速稳定动态响应.
A new type two-stage proportional electro-hydraulic regulator valve using piezoelectric ceramics is promoted to cancel the requirement of pressure sensor. The piezoelectric ceramics controls the openness of pilot valve. The pressure drops across the fixed damping hole in the pilot supplier, and the throttling orifice of the pilot valve change accordingly. Thus the output pressure of pilot stage is controlled by the piezoelectric actuator and it serves as the command pressure to the main stage. The detailed structure and working principle have been given, and mathematical models and simulation models have been established. The influences of structural parameters over static and dynamic performances have been studied by Simulink simulation. A tuning spring has been employed to extend the lower bound of output pressure to 0. A three-land main spool has been employed to reduce the flow force and increase the precision, which is verified by flow field analysis. Proper feedback damping hole has been chosen according to dynamic simulation to ensure dynamic performance of pressure reducing valve. The new type valve proved to be able to work as a pressure reducing vavle without empoying a pressure sensor, and it has good output pressure range, pressure precision and fast and steady dynamic response.