Simulace statických a dynamických charakteristik proporcionálního rozváděče

Abstract

This dissertation deals with the experimental analysis of the proportional directional valve as a whole and also its partial parts affecting its behaviour, for which a mathematical description is developed. The experimental analysis of the directional valve parameters will be used to verify the subparts of the model, which together form the overall model of the directional valve. An experimental hydraulic device is designed to perform the individual measurements. The simulated static and dynamic characteristics on the developed simulation model are compared with the results of the experimental analysis. Using the Fluent computer programme, the flow analysis is performed through the throttling cross sections of the directional valve. The hydrodynamic force acting on the spool is determined by a 3D numerical simulation and is also determined by the experimental method. In the area of the centre position of the spool, the largest leakage of fluid occurs due to leaks between the spool and the sleeve. The effect of the size of the axial clearances, due to manufacturing tolerances, on the size of the leakage through the directional valve was further analysed in Fluent. To verify the correct functioning of the developed proportional directional valve model and the possibility of its use also on other hydraulic circuits, this model was implemented in the assembled simulation model of a hydraulic circuit with a hydraulic cylinder and a mass load. To verify the results of the simulations performed using the developed hydraulic circuit model, a real hydraulic circuit corresponding to the simulation model was built.