大流量压电式高速开关阀设计与仿真测试

Design, Simulation and Test of High-flow High-speed on/off Valve Driven by Piezoelectric

针对目前高速开关阀快速性的不足及大流量的需求,利用压电晶体响应快速的特点,设计一种压电直动式高速开关阀,采用压电执行器直接驱动锥阀式阀芯结构,控制开关阀开启和关闭。设计桥式位移放大结构,放大压电执行器的输出位移,提高开关阀的控制流量。为补偿锥阀式阀芯结构开启、关闭过程中的液动力波动,提出锥阀+滑阀的组合式阀芯结构,建立其液动力模型,分析开关阀启闭过程中的负载力变化。建立压电直动式高速开关阀的数学模型,结合AMESim仿真软件分析、优化影响其性能的设计参数。搭建压电高速开关阀静态流量及动态启闭特性的试验测试平台,测试开关阀流量特性、启闭时间等性能指标,分析PWM控制载波频率及占空比与开关阀静态、动态流量之间的关系。基于设计参数仿真和实物样机试验测试结果表明,设计的压电式开关阀在压力10MPa下,输出流量17.4L/min,开启时间1.05ms,关闭时间0.85ms,实现大流量与快速性的要求。研究工作可为高速开关阀精确流量控制提供理论基础,对于拓展数字液压技术的应用具有重要意义。

A piezoelectric(PZT)direct-acting high-speed switching valve is designed in order to improve the lack of rapidity and large flow.In view of the fast response of PZT crystal,the PZT actuator is used to drive the conical valve core structu re directly,which open and close the on/off valve.A bridge-type displacement amplification structure is designed to amplify the displacement output of PZT actuator,which increases the control flow of the switching valve.A combined structure of cone valve and slide valve is proposed to compensate the hydrodynamic fluctuation during the opening and closing process of PZT switching valve.The hydrodynamic model is established to analyze the change of fluid load force.The mathematical model of PZT high-speed on/off valve is established,and the design parameters affectin g its performance are analyzed and optimized by AMESim simulation software.The test platform for static flow rate and dynamic open-close characteristics of PZT high-speed on/off valve is built.The PWM driving and control methods are studied based on the performance indexes such as flow characteristics,opening and closing time.The relationship between carrier frequency,duty cycle and static,dynamic flow of on-off valve is analyzed.The simulation and experimental results based on the prototype and desi gn parameters show that the designed PZT on/off valve has a flow rate of 17.4 L/min,an opening time of 1.05 ms and a closing time of 0.85 ms at the pressure of 10 MPa.The requirement of high speed and large flow is realized.The research work provides a theoretical basis for the accurate flow control of high speed on/off valve and is of great significance for the application of digital hydrauli c technology.