The Design And Research Of Pilot Type Zero Steady-state Error Of Water Hydraulic Pressure Reducing Valve

Hydraulic transmission, which has many outstanding advantages such as utilizing green energy, environment protection, safety&reliability and lower-cost&abundance etc, will become to a main developing direction in the field of fluid power transmission&controlling in future. The pressure value, as one of the key component in Hydraulic Transmission, is particularly important for researching of it’s higher performance. But the pressure value do have some negative features, for example, the static-state error, with the impact of high vapor pressure, the low viscosity and the small compressibility of water, the pressure value will easily come up with produce cavitation erosion and wire drawing because of the significantly increased fluid power and friction. Those appearances would seriously affect the performance of the pressure value and its life cycle. Therefore, to eliminate static-state error of the valve becomes one of the problems in improving the regulating accuracy of hydraulic pressure valve.This paper first introduced the hydraulic transmission and pressure valve of the development process, present situation and research at home and abroad, defines the static-state error, illustrates the generation mechanism and reveals its essence. By analysing of static-state error in the hydraulic control system it sums up the harm of the static-state error, followed with indicating the difficulties in eliminating of static error, and giving up the key technology against those difficulties which provides the theoretical guidance in the design of static water pressure reducing valve. Then, on the basis of experiences in designing of the hydraulic valve control, this paper designs a new type of static water pressure reducing valve with a special structure which can complete the internal dynamic pressure feedback of the valve. According to the design index, it designs&calculates the basic parameters of the valve structure. Further more, it selects based on the particularity of virous types of material which are utilized in water pressure control valve. The SolidWorks Flow Simulation model is also been used in simulation based analysis of the pilot no static water pressure reducing valve for flow field in order to validate the rationality of this structure.Finally, this paper establishes the pilot with no static and dynamic mathematical model of water pressure, and analyses the static and dynamic characteristics by using MATLAB simulation, which provides the static pressure characteristic curve, static pressure flow curve. It comes up with a result that this valve has good static pressure, and high precision pressure regulator. Based on static calculation formula, the valve static error remains lower than0.3%, which keep within the requirement of design indexes. The simulation results prove that the valve takes up a stable outlet pressure in the step response with a time interval of about2seconds, it gets the amplitude frequency, which is at4.8Hz.