| Load-sensitive Multi-way Valve,as one of the hydraulic control components,is widely used in excavators,loaders and other mobile machines because of its independent flow distribution function,which enables each actuator to perform complex and coordinated actions,and is responsible for realizing the control function of the entire system.,In practical applications,due to the poor controllability of the pressure compensation valve to the pressure difference of the main valve in the small opening state of the Load-sensitive Multi-way Valve,the fine movements of the excavator often appear low-frequency jitter due to poor fretting characteristics,and the load mechanism is channeled.In addition,the Load-sensitive Multi-way Valve has a compact structure and has high requirements on the assembly accuracy of each component.During the highpressure operation,the multi-way valve will be partially deformed,and problems such as clamping and leakage often occur.Research on Load-sensitive Multi-way Valve.Paper analyzes its structure and the working principle of the pressure compensation valve in detail,deduces the flow distribution relationship between the main control valve and each actuator.The key components of the load-sensing multi-way valve are designed and calculated.Aiming at its poor fretting characteristics and multi-parameter coupling problems,the AMEsim simulation platform is used to create a simulation model of a Load-sensitive Multi-way Valve,and the function of Load-sensitive Multiway Valve in complex working conditions is verified.The influence of the key parameters of the pressure compensation valve on the fretting characteristics and the corresponding parameter optimization are studied fundamentally.The conclusion shows that when Load-sensitive Multi-way Valve works in a small opening state,the stability of the pressure difference between the inlet and outlet of the main valve is poor,and the output flow fluctuates obviously.Through the research on the influence of the key parameters of the pressure compensation valve on the fretting characteristics of the load-sensitive multi-way valve,with the goal of reducing the fluctuation of the pressure difference in the small opening of the main valve,the NLPQL optimization algorithm is used to determine the spring stiffness,preload,orifice diameter,and cavity.The parameters of the length are optimized,and the fluctuation of the small opening pressure difference before optimization is optimized from 0.41 MPa to 0.35 Mpa,and the fluctuation amplitude is reduced by 15%.Aiming at the influence of high pressure deformation on the multi-way valve,the one-way fluid-structure coupling method was used to study the influence of high pressure fluid on the deformation of the load-sensitive multi-way valve valve body and valve core during the working process of the multi-way valve,and the slippage caused by this deformation was studied.Changes in valve pair clearance and multi-way valve seizure and leakage are analyzed.The conclusion shows that during the reversing process of the load-sensitive multi-way valve,due to the action of high pressure fluid,the deformation of the valve body and spool at the oil inlet is the largest,the maximum deformation of the valve body is at the inlet position of the reversing valve cavity,and the spool is the largest.The amount of deformation moves from the oil inlet valve port to the oil outlet port;in the small opening state of the valve port,the fitting clearance of the multi-way valve slide valve pair is closest to the fitting clearance.As the opening of the valve port increases,the gap width of the spool valve pair changes rapidly,and the internal leakage also increases.When the valve port is fully opened,the matching clearance of the slide valve pair is the largest,and the internal leakage is also increased by 1.6 times. |
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