No abstract

A spool-type, hydraulic, directional-control valve is considered. The valve has four ports; it is actuated by a solenoid, and its spool overlaps the ports. The valve is looked upon as a system consisting of electrical, mechanical and hydraulic sub-systems. The sub-systems are represented as networks, which are then interconnected to form the network of the complete valve system. Hence a set of independent equations are derived which describe the dynamic behaviour of the valve between no flow and full flow states of the spool. The equations are simulated on an analogue computer to provide comparison with experimental results.