Characteristic Research Of The Pilot Relief Valves With Conical Press-Adjusting Spring

Pressure relief valve is a very important pressure controller in hydraulic and pneumatic transmission system,almost all pneumatic & liquid transmission and control systems include the relief valve.Pressure relief valve has many functions,It's mainly used to limit the system's pressure to a constant value or prevent hydraulic system overloading.The the relief valve has a great influence on the performance quality and reliability of entire hydraulic system,therefore,in order to improve the performance of the valve and improve the stability of the system,the relief valve should be further studied.But at the present stage,there are still some problems such as low pressure regulating precisionthe,serious vibration and noise and higer pressure overshoot.The method of improving its performance is the most important part of the relief valve research at the present stage.This paper creates a new method for improving the performance of the relief valve,by changing the structure of the regulating spring to find ways to improve the performance of the valve,this method provides a new research direction for improving the performance of relief valve,and opens a new pattern for the design and research of relief valve.This paper introduces the basic situation of the relief valve,including functions,performance index,research status at home and abroad,and by making the YF-L20 H type relief valve as an object,to study the characteristics of the relief valve with conical pressure regulating spiral spring in this paper.This paper includes five parts:(1)Introduce the YF-L20 H type relief valve,describe the composition of the relief valve and it's working principle,and study the characteristics of the relief valve.(2)According to the requirements of the project,a new constant pitch conical spiral compression spring is designed to replace the pilot valve cylindrical pressure regulating spring.(3)According to the deformation formula of single coil conical spiral spring,the program of spiral compression spring characteristics is builded by MATLAB,and the characteristics of conical spiral compression spring are studied,and variation of spring stiffness is obtained.(4)UsingMATLAB software programming method to analyze the static characteristics of pressure relief valve;using Simulink simulation software to design modeling of pressure relief valve and study the dynamic characteristics of valve.In the last of the part,it is compared the simulation results with the original performance of the relief valve.(5)In the MATLAB/Simulink simulation environment,by changing the structural parameters of conical pressure regulating spring and valve body,the change situation of new type relief valve of the static and dynamic characteristics is analyzed.The results show that the dynamic response characteristic of the regulating spring determines dynamic response characteristics overshoot and the degree of fluctuation of inlet pressure;the conical spring 1,increasing in the process of the pilot valve opening the stiffness of the regulating spring can reduce spring response overshoot,but the pressure overshoot and the transition time of the inlet pressure response of is increased,so by increasing the stiffness of the regulating spring to improve the dynamic characteristic is infeasible;the dynamic and static characteristics of the relief valve designed by the conical spring 2 are the same as that of the original relief valve,it can also increase the range of regulating voltage,reduce noise,prevent resonance,and improve the stability of the valve;increasing the big and small end of the radius of the conical spring or increasing the pitch,the stiffness of the conical spring decreases,the stability time and overshoot of the inlet pressure of the relief valve have no obvious difference,and the inlet stability pressure will decrease obviously.