Dynamic characteristic of π bridge electro-hydraulic proportional relief valve

The new electro-hydraulic proportional relief valve with pilot π bridge hydraulic resistance network was developed. The mathematic model and simulation block of the valve were built and the simulation analysis was finished by Simulink software. The steady state pressure-flow performance and dynamic characteristic of the valve was investigated by experiments. The π bridge electro-hydraulic proportional relief valve with different load performances can be designed by changing the parameters of the pilot control valve. When the steady state override of the valve is larger than 0.5 MPa, the dynamic characteristic of the valve is good, if the steady state override is less than 0.5 MPa, the dynamic characteristic is still stability, but the value of the steady state time becomes larger. Furthermore, If the steady state override of the valve is less than 0.3 MPa, the valve may be not stability. The research shows that when the steady state override of the π bridge electro-hydraulic proportional relief valve is designed as 0.5 MPa. Both the load performance and dynamic characteristic of the valve are good.