Study On The Life Of The Water Hydraulic Control Valves And Malfunction Analysis

Water hydraulics technology is one of the top research aspects in fluid power transmission and control. Water hydraulic control valves are important and the key base components in water hydraulic system. Three kinds of water hydraulic control valves, which consist of relief valve, directional valve and throttle valve, are designed by the state key laboratory of fluid power transmission and control in Zhejiang University. The experiment results of these valves show us that, the performances of these water hydraulic control valves achieve the level of traditional oil control valves. But the lives of these are unknown, and we must find the answer. This is the key step of bringing the valves into market. In this dissertation, the static and dynamic performances are carried out, and design a control circuit of life experiment, and also carried out the life experiments with all of the water hydraulic valves. Last, the malfunction analysis and improvement are accomplished. The main contents of this dissertation are listed as follows:Chapterl presents the introduction, which includes the key technology, the development status of water hydraulic control valves and the technical solutions faced to resolve of water hydraulics. The research significance of the paper and the main research contents are expatiated.Chapter2 introduces the improvements on water hydraulic control valves performance test rig. The original test rig appears some faults, such as leakage, some valves of the system adjusting invalidation, and so on. Through the analysis with the test rig principle, all of the components and all of the pipelines in the system are diagnosed. Then the improvement methods are given, and solve the problems of the test rig completely.Chapter3 introduces the performance test of water hydraulic control valves. All of the water hydraulic relief valves, directional valves and throttle valves are experimented in performance test. The main contents of the relief valve include extension of pressure adjusting test, open and close performance test, unload pressure test, pressure lose test, pressure—flow performance test, flow impulse pressure response performance test and unload—load performance test; the main contents of the directional valve include pressure lose test, work scope test and dynamic response performance test; the main contents of the throttle valve include extent—flow performance test, pressure difference—flow performance test and dynamic response performance test. The experiment results prove that, the performances of these water...