Modeling of Dynamic Behaviors of a Poppet Valve

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.

Flow model and dynamic characteristics of a direct spring loaded poppet relief valve

“…where is the physical parameter of the control volume, v f is the velocity of surface element in the control volume, n is a unit normal vector on the control surface directed outwards, and A is the control surface. Substituting equation (11) into equation (12) and replacing by v r , equation (11) can be rewritten as Figure 8 shows the control volume for calculating poppet valve flow forces.…”

“…[6][7][8][9] Thus far, with regard to the poppet relief valve static and dynamic characteristics studies, many scholars have considered the poppet valve flow model, static characteristics, instability, cavitation, axial vibration, chaos, dynamic characteristics and control, and the research methods include analytical method, test method, and finite element method. 7,[10][11][12][13][14][15][16] As the results presented in the former related researches, it obviously indicated that the dynamic characteristics of the poppet valve, which attracted a lot of attentions in both academic and industrial area, were rather important.…”