一种脉宽调制式数字流量阀性能分析

数字阀有抗干扰、抗污染等优点，但直接控制的脉宽调制（PWM）式数字阀控制流量小、出口流量不连续等缺陷而限制了其应用。为此，设计出一种两级数字流量控制阀，其先导级采用基于PWM的高速开关阀，主级采用基于流量-位移反馈的插装阀，该数字阀具有结构简单、能量利用率高、先导数字控制、主阀连续输出流量等特点。阐述了该数字流量阀的工作原理，在SimulationX软件中建立了相应的数学模型，利用试验数据对主阀和先导阀模型进行了验证，通过仿真和理论推导得出主阀阀芯位移、总流量、放大倍数等参数与结构参数的关系，并对其性能进行了分析。结果表明：该数字阀工作原理是可行的，通过调整先导阀PWM控制信号占空比即可改变主阀出口流量。研究结果对该数字阀的进一步研发和改进有重要意义。

Analyses of Characteristics of a PWM Digital Flow Valve

Digital hydraulic valve had the advantages of reliability, low sensitivity to contamination, which was controlled by PWM and was limited in hydraulic system by the small and discontinuous flows. A two-stage digital flow valve was presented，where the pilot stage was as high-speed on/off valves and the main stage was as a cartridge valve based on flow-displacement feedback principles. There were features of simple structure, high energy efficiency, piloted digital control, continuous output flow. The working principles and a simplified mathematical model were presented. The performance of the valve was investigated by means of simulation. The results show that the digital valve working principles are feasible and the valve output flow can be continuously changed by adjusting the duty ratio of the PWM signals supplied to pilot valve. There are important significance to further research and improvement of the valve.