PWM间歇喷雾变量喷施系统压力脉动及液压冲击综合测试

AComprehensive Study on Pressure Pulsation and Hydraulic Impact in PWM- based Intermittent Spraying Variable Rate Application System

在PWM间歇喷雾式变量喷施系统中,隔膜泵间歇性吸排液等特点会在管路中形成压力脉动,且电磁阀快速启闭会在管路中形成液压冲击,二者综合作用致使各喷头的实际喷雾压力发生波动,导致其喷施流量和雾化特性出现畸变。因此,为了揭示其管路压力脉动的变化特性和液压冲击特性,构建了一套PWM间歇喷雾式变量喷施系统,并在不同隔膜泵转速、不同PWM控制信号频率和占空比下进行了压力脉动和液压冲击的综合测试研究。结果表明:随着隔膜泵转速的增加,压力脉动周期逐渐变小,幅值逐渐变大;随着PWM信号频率的增加,液压冲击和压力波动趋于压力脉动的形式,周期逐渐变小,幅值逐渐变大;而PWM信号占空比对液压冲击和压力波动的影响不明显。

In PWM intermittent variable spraying system, the intermittent imbibing and draining of diaphragm pump lead-ing to pressure pulsation, and the rapidly start/stop of solenoid valves leading to hydraulic impact, all these working to-gether generates the fluctuation of spraying pressure in every sprayer. And the pressure fluctuation leads to the distortion of the spraying quantity and atomization character. In order to study the characters of pressure pulsation and hydraulic im- pact, a PWM interval atomizing variable spraying system was constructed and comprehensive test and study of pressure pulsation and hydraulic impact in different diaphragm different duty ratios was conducted. It turned out that, tion period gradually decreased, and the amplitude of pump rotate speed, different rates of PWM controlling signals and when diaphragm pump rotate speed increased, the pressure pulsa- fluctuation gradually increased; when the rate of PWM controlling signals increased, hydraulic impact and pressure fluctuation tend to the form of pressure pulsation, period decreased and amplitude increased gradually; while PWM duty ratio affect hydraulic impact and pressure fluctuation less.