Research On Valve Port Characteristics And Hydraulic Force Of Load Sensitive Multi-way Valve

Hydraulic valves are widely used in construction machinery,hoisting and transporting machinery and walking machinery that require multiple actuator movements.They are important control components in hydraulic working systems.Among the factors affecting the control characteristics of the hydraulic valve,the influence of the hydraulic power is the most prominent and difficult to calculate.Excessive hydraulic power causes the spool to become stuck,which affects the reliability and safety of the actuator.By properly arranging the shape of the notch,different throttling areas can be obtained,so that multi-stage throttling control can be performed on the flow.It can meet the requirements of the movement speed of the actuator under different loads,so that the hydraulic actuator can start and stop smoothly.Therefore,the analysis of the flow characteristics of the throttle groove and the reduction of the hydraulic power of the spool are critical to the design of high-quality multi-way valves and the improvement of the operating performance of construction machinery.This paper takes DCV95 load-sensing multi-way valve as the main research object.According to the multi-way valve model and parameters provided by the company,the over-flow area of the main valve orifice chute is deduced,and the general calculation program of the valve port over-flow area is prepared.The valve over-current area and hydraulic diameter calculated by software replace the over-flow area value in AMESim,which improves the simulation accuracy.Using AMEsim and Fluent joint simulation method,the influence of the shape and size parameters of the throttle notch on the performance of the valve is explored.The simulation model of the multi-way valve is constructed by the hydraulic component library(HCD library),and the simulation results of the flow characteristics during the opening and resetting of the multi-way valve under different loads are obtained.The results show that during the process of opening and reversing the spool,the pressure of the load is independent of the flow rate of the valve port.The change of the valve flow curve is only related to the opening of the valve port.The internal flow field of the multi-way valve was modeled in three dimensions,and the ICEM software was used for mesh division.Flow field simulation analysis of the built model was performed using FLuent software.A more precise study of the internal flow of the main valve port.By analyzing the pressure distribution cloud map and the velocity distribution cloud map distribution in the flow field of the spool valve,the causes of excessive pressure and eddy current in the valve cavity are obtained.The results show that when the valve opening is changed,the oil flow rate and pressure distribution in the multi-way valve change greatly.At the same time,as the valve port increases,the eddy current phenomenon at the wall surface becomes more and more obvious,and the pressure on the wall surface becomes larger.For the problems of the multi-way valve,the pressure compensation valve throttle groove structure and the valve body flow passage size are modified.Through simulation experiments,the results show that the two reforming methods can improve the control performance of the multi-way valve.The research in this paper provides a numerical basis for improving the flow control range of the multi-way valve and reducing the hydraulic power of the spool.It is instructive to improve the control performance of the valve and improve the design of the valve port structure.