Modelling and validation of a fast switching valve intended for combustion engine valve trains

Abstract

In recent years much research has been done in the area of variable-valve actuation in order to improve the efficiency of combustion engines. Currently, a number of different concepts for variable-valve actuation are under development or at a prototype stage. Hydraulic actuation has been an obvious candidate, but the lack of sufficiently fast switching valves with appropriate flowrates has been the major shortcoming. Design of such highly dynamic systems requires accurate models of the actual included components. In this paper a model of a fast 2/2 switching valve is presented, where both the magnetic path as well as the spool assembly are modelled. The model presented here is primarily aimed at system simulations; therefore it has to be kept simple with the number of parameters low. Some of the parameters are often hard to obtain, especially when it comes to magnetic material properties. In this study, an optimization strategy has been utilized in order to parameterize the model against measured data. However, even for major deviations from the operational point used for the model adaptation, the model predicts the valve response sufficiently accurately.