Study On Characteristics Of The π Bridge Electrohydraulic Proportional Relief Valve

This paper usesπbridge hydraulic resistance network instead of B half bridge hydraulic resistance as the pilot control loop in the electro-hydraulic proportional relief valve. And the new valve is called theπbridge electro-hydraulic proportional relief valve.Focuses of this paper are on the structural design, the structural parameters calculation, the dynamic characteristics and the static characteristics analysis, experimental study. (1) Characteristics of the G-πbridge hydraulic resistance network are analyzed, and a new type electro-hydraulic proportional relief valve is designed, which is based on the G-πbridge hydraulic resistance network. Theπbridge electro-hydraulic proportional relief valve's pilot valve structural design is a key part of the design. Structural parameters design including the pilot and main valve spool design, valve set and main valve spring design, pilot control piston design. Finally the whole process valve drawings are carried out. (2) Load characteristics of theπbridge electro-hydraulic proportional relief valve are analyzed. The mathematical models of theπbridge electro-hydraulic proportional relief valve and the ordinary electro-hydraulic proportional relief valve are linearized in order to get the expressions of the deviation. And we can see the deviation of theπbridge electro-hydraulic proportional relief valve is 5.52% of the ordinary electro-hydraulic proportional relief valve.This paper sets up the ordinary electro-hydraulic proportional relief valve and theπbridge electro-hydraulic proportional relief valve's mathematical models, respectively. And we can get the characteristics of theπbridge electro-hydraulic proportional relief valve. (3) Dynamic characteristics simulation of the two valves is carried out. This paper sets up the dynamica simulation models by the dynamic mathematical model of theπbridge electro-hydraulic proportional relief valve, the model has seven sub-models, and every sub-model reflects a dynamic parameter or the input model. The simulation model is based on input signal that is the electro step signal, and the output signal that is the output pressure signal, which is the setting pressure. Transfer function block diagrams and MATLAB/simulink simulation models are established, and we get the dynamic characteristic is better than the valve without transmission power spring by the simulation and analysis. (4) The static and dynamic characteristics are studied by experimental test. The experimental test is reconstructed in order to test the electro-hydraulic proportional relief valve. Static characteristics are tested from pressure control characteristics and load characteristics. Dynamic characteristics are tested from inputting step electro signals and the step load flow signals. The simulation results and the test results are comparatively analyzed in order to receive that the simulation methods and simulation models are accurate, and they could be used for this type study. And the same we can get theπbridge electro-hydraulic proportional relief valve is a new valve with superior allround performance.