Abstract
The traditional attitude so far adopted to formulate mathematical models for oil hydraulic valves was the one relying mainly upon the classical knowledge accumulated in hydraulics. The present authors previously found out, however, that the traditional ‘hydraulic’ model does not properly express the static characteristics of a poppet valve in a highly viscous oil flow. In the present paper attention is paid to modeling of the valve's dynamic performances. The primary concern lies in if the steady characteristics of a variable poppet constriction are available for simulating its unsteady ones. The proposed model was experimentally examined by the frequency response method, which becomes executable only with the help of the formerly developed technique to measure fast-varying differential pressure and fl ow rate. It turned out that the model properly predicts actual unsteady behaviors of the poppet valve, except when the frequency is larger than 400Hz.
