The Stability Analysis And Improvement Of Relief Valve In Proportional Directional Spool Valve Based On The Load-Sensing Principle

The multi-way directional valve are widely used in the hydraulic system of centralized control of multiple actuators, due to the piping compact and reasonable structure, small pressure loss, fast response, easy installation etc., and so the research on the multi-way directional valve is increasingly being taken seriously by domestic and foreign scholars. This paper mainly selects the PSL proportional directional spool valve based on the Load-sensing principle as the research subject. The valve requires high stability in the system, so this research puts focus on the working characteristics and stability of the PSL multi-way valve. Through surveying the problems of the valve, aimed at the flow stability problem of the secondary pressure limiting valve in small flow, simulating the multi-way valve system, analyzing its characteristics and proposing some improvements.Firstly, using CAD and PRO-E software to build the model for PSL multi-way valve based on the load-sensing principle, specifically analyzing its working principle and internal structure of the composition, putting emphasis up on analyzing the working principle of Three-way flow control valve and Two-way pressure compensation valve. While this paper also deduces the calculation formula of valve orifice flow area of the two-way pressure compensation valve provides the basis for the later system modeling.In order to study the working characteristics of PSL multi-way valve, according to the specific structure of multi-way valve, this paper uses the AMESim software to establish a system model. Simulating the system by setting different valve opening and different loads, PSL multi-way valve has adaptive characteristics with flow, that is to say:The flow into the load changes with a corresponding proportion of the valve opening, independent of load variations.Secondary pressure limiting valve in multi-way valve is simulated in a small flow condition. Analyzing its flow fluctuations, setting the different parameters in diameter of the orifice at the different positions respectively to analyze the influence on the stability of valve; raising a new combination proposal to effectively reduce the magnitude of the flow fluctuations and improved the stability. Concluded that: matching combination of orifice diameter can get better program with their own advantages; the final plan can be determined in the light of the actual requirements.