Model of hydraulic double-acting drive for valves of internal combustion engine

The article presents the idea and the model of electrohydraulic double-acting valve drive for internal combustion engine. In this solution to control the position of the engine valve used Rexroth's servovalve and the double-acting actuator. This drive should give free control of valve lift, valve open andvalve close time. In the article the principles of the operation and the mathematical model of the drive are described. Submitted model gives bases to the initial value definition of the main parameters of the hydraulic drive. It lets execute the analysis of the features of such drive and point necessary modifications for the correct realization of the process of the gas exchange in internal combustion engine. The first results from the simulation showed that proposed solution allows obtaining desirable run of lift of valve in the wide range of engine speed. Comparisons of valve lift proceedings driven hydraulically and mechanically by the use of harmonic cam, for two engine speeds, obtained from simulations are presented in the article. These comparisons show that at greatest engine speeds it is indispensable the use of pressures of the working liquid exceeding 10 MPa to obtain nearing results to the classical mechanical timing gear. Preliminary simulation test results indicate that it may ensure desired run of lift of valve in the wide range of engine speed