| Aviation hydraulic valves are important control components aviation hydraulic system. Their performance and work reliability directly relates to the flight safety of air planes. Oil contamination is one of the main factors that affect the performance and work reliability of hydraulic valves, so aviation hydraulic valve contamination sensitivity research is really meaningful to assure the flight safety of air planes.On the basis of the completed aviation hydraulic valve contamination sensitivity test stand, this paper firstly perfected the test stand, solved the singal interference problem of the test stand. Secondly, this paper completed part of the performance tests of aviation hydraulic reducing valve and safety valve in clean oil (GJB 420-87B 9/6) and contaminated oil (GJB 420-87B 20/17). The test result shows that oil contamination does not badly influence on the static characteristics of the tested reducing valve, such as pressure range, pressure shift and pressure reducing stability, but evidently makes the response time and recovery time of the tested reducing valve longer, makes the opening pressure ratio bigger and the closing pressure ratio smaller for the tested safety valve. Finally, combination with the structure of the two tested valves, this paper analyses the reasons of the performance change of the tested valves.The study and work of this paper make it possible to fully develop the study on aviation hydraulic valve contamination sensitivity and rationally set the target cleanliness of the aviation hydraulic system, possesses very strong practical value. |
