等温容器放气法测定气动电磁阀流量特性的研究

对一种新的测试气动元件流量特性的方法进行了研究,即利用等温容器的放气曲线来测量气动电磁阀的音速流导C和临界压力比b。首先介绍了测试原理与测试方法;随后对4种等温容器进行了实验研究,结果表明:容器中填充丝的密度越大,等温性能越好,同时流阻越大;接着用这4种容器来测试同一电磁阀的流量特性,测量得到的数据表明:用等温容器可以成功实现电磁阀的流量特性测试,但并不是等温性能越好误差就越小。经分析可知容器的温度特性和流阻特性对测量元件流量特性时的误差有着不同的影响,温度偏差引起流量测量的正偏差,而流阻则引起流量测量的负偏差,存在一个最佳填充密度。采用等温容器这种新的流量特性测试方法比ISO6358省时省气,该研究进一步推动了等温容器的实用化进程。

Study on Measuring Flow Rate Characteristics of Pneumatic Solenoid Valves by Isothermal Chamber Discharge

This paper studies, a new method for measuring flow rate characteristics of pneumatic solenoid valves, namely measuring sonic conductance C and critical pressure ratio b of pneumatic solenoid valves using discharge pressure curve of isothermal chambers. First, the principle and method of measurement are introduced. Second, four kinds of isothermal chambers are experimentally studied, and the experimental results indicate that the more copper threads stuffed, the better isothermal characteristics and the larger flow resistance. Finally, the isothermal chambers are used to measure the flow rate characteristics of same solenoid valves, and the measurement results indicate that the isothermal chambers can successfully test the flow rate characteristics, but they do not indicate that the better isothermal characteristics the smaller errors. By analysis, we know that isothermal characteristics and flow resistance diversely affect the errors, which isothermal characteristics lead to positive errors while flow resistance leads to negative errors. Measuring flow rate characteristics with isothermal chambers saves time and consumes less energy than ISO 6358 procedure,and the study promotes the practicality course of isothermal chambers.