Research On Test System Of Aviation Hydraulic Valve's Contamination Sensitivity

Aviation hydraulic valve is the very important control component in aviation hydraulic system, it is related to the stable and safe flight of airplane. Solid particle contamination is one of the critical factors which influence aviation hydraulic valve's working performances and reliability. At the condition with mass particle contaminations inevitably exist in the hydraulic systems, after a period of working time, hydraulic valves are easily been weared, tightened, blocked, and even been failure. So it is really necessary to study the aviation hydraulic valve's contamination sensitivity.On basis of summing-up the three damage forms of solid particles to hydraulic components, combining the structural principle of relief valve, pressure reducing valve and directional valve, theory analysis of previous hydraulic valve's performance changed by solid particles was made. According to the actual requirements, the former researchers' study and previous theory analysis, parameters of previous hydraulic valve's contamination sensitivity were determined.On basis of previous study, a suit of aviation hydraulic valve's contamination sensitivity test stand was developed. The test stand can be used to do pressure reducing valve's contamination sensitivity test in flowrate of (2～12) L/min and pressure under 21MPa, relief valve and directional valve's contamination sensitivity tests in flowrate of (10～60) L/min and pressure under 27MPa.Several problems were solved in the test stand building, such as solid particles' uniform distribution in oil and confliction between automatic control and oil's high contamination. VB language-based software developed for the test system accomplished the following functions satisfactorily, such as the control of the test stand and parameters' acquisition, storage, processing, output and etc.This test stand's development effort provide reliable basis for establishing aviation hydraulic system's oil cleanliness. It makes the contamination control of aviation hydraulic system more scientific and effective.