Research on improving dynamic characteristics of counter balance valve

Counter balance valve is an important control element used in hydraulic balance circuits. This paper introduces the working principle, mathematic model and computer simulation results of a hydraulic balance circuit. From the theoretic analysis and simulation, it can be seen that under the condition of big flow or after 2/3 spool stroke, the system would be unstable. The authors suggest that a construction of flow section area with changeable gain and a spring with gradually reducing rigidity should be used to resolve the contradiction between fast response and stability.