低温环境中热冲击载荷对电液伺服比例阀动态性能影响测试

Testing the Effect of Thermal Shock Load on Dynamic Performance of Electro-hydraulic Servo Proportional Valve in Low Temperature Environment

低温环境中液压元件动态特性对系统整体性能与功能的影响至关重要。为研究电液伺服比例阀在低温环境中受到高温油液热冲击载荷时动态性能的变化,在设计的低温液压综合试验系统中对某型电液伺服比例阀进行了不同温度下的冷启动与热冲击阶跃响应特性和频率响应特性试验。对比分析测试结果表明,无论是冷启动还是热冲击工况下,随着环境温度降低,油液黏度增加,被试阀的响应时间都会逐渐变长。热冲击工况下的响应时间比冷启动工况下短,但相较于常温启动要长。当环境温度越接近于油液工作的极限低温,其对阀动态性能的影响越显著。

The dynamic characteristics of hydraulic components in low temperature environment could significantly affect the overall performance and function of the whole system.In order to study the dynamic performance of electro-hydraulic servo proportional valve under the thermal shock load in low temperature environment,an electro-hydraulic servo proportional valve was tested in the designed comprehensive low temperature hydraulic test system in different temperatures,including the step response characteristics and the frequency response characteristics of the tested valve in the cold start and thermal shock modes.The results showed that the response time of the tested valve would be longer with the decrease of ambient temperature and the increase of oil viscosity.The response time in the thermal shock mode is shorter than that in the cold start mode,but longer than that in normal temperature mode.When the ambient temperature is closer to the lower limit working temperature of oil,its influence on the dynamic performance of the valve is more obvious.