Research On Key Technology Of Automatic Compensation In Smaller Load Of Load Sensing Multiwayvalve With Branch Circuit Ratio

Load sensing multiwayvalve with branch circuit ratio is one of the load sensing multiwayvalves which is used in fuel-efficient hydraulic system of engineering machinery and other machines with actuators,it can greatly improve the speed coordination of the actuators.When the requiring flow rate is greater than the maximum flow rate of sysem,every actuator is provided the flow rate to be proportianal to the stoke of operating lever,so the actuators can keep the coordination.This subject will make an study of the automatic compensation in smaller load of load sensing multiwayvalve with branch circuit ratio.This paper is mainly made up of four parts:1. Principle research. On the basis of analysing the principle of the classical load sensing multiwayvalves with branch circuit ratio,we find out the defect when the maximum load pressure approaches the output maximum pressure of system. This subject will make an study of the automatic compensation in smaller load of load sensing multiwayvalve with branch circuit ratio,and demonstrates it not only has the all characteristics of classical ones but also it has the attribute of automatic compensation in smaller load from the standpoint of the priciple deduction.2. Structure design. On the basis of analysing the structual drawings of many classical multiwayvalves and draw out the structual drawing of automatic compensation in smaller load of load sensing multiwayvalve with branch circuit ratio.lt includes filling valve,three load valves and the valve choosing load sensing signal. Then design the key parameters of fit clearance,leakage,shape and dimensions of orifice,curve of orifice area,spring rate and compression of spring.3. Modeling and Simulation. Firstly,the system of load sensing multiwayvalve with branch circuit ratio is modelled, it includes the models of a pilot valve,load sensing multiwayvalve with branch circuit ratio and a variable capacity pump with load sensing. Secondly, analyse the characteristics of pressure drop equality, flow distribution,anti-saturation and pressure drop compensating automatically of smaller load; analyse the leakage between spool and valve body; analyse the braking,closing the orifice suddenly and the suddenly change of the maximum load pressure in the moving of the main spools; analyse the response speed of the main spools and two position three-way valves.4. Optimum design. Optimize the parameters of spring rate and compression of spring of the main spools,sequence valve and two position three-way valves.