The effect of machined valve springs application on dynamic properties of electro-hydraulically driven valve train

Nowadays, the constant striving to reduce the emission and increase the overall efficiency over a wide range of speeds and loads of the internal combustion engine (CE) is observed. The different methods for improving the charge exchange in the engine, particularly ones based on the variable valve timing are sought. This variability can be achieved, among others by using the electrohydraulic valve drive. The goal of the present study is to compare the dynamic parameters of the engine valvetrain utilizing the unilateral electrohydraulic valve drive and various types of valve springs. The model of such a drive being developed by authors and experimentally verified was used for the analysis. Using the Finite Element Method, the models of springs made through the machining from single sleeves were developed. The effect of various geometrical parameters of the modernized springs on their stiffness and on the resulted valvetrain dynamics was examined.