Analysis of Dynamic Interactions in Valve Train Systems of IC- Engines by Using a Simulation Model 930616

In order to evaluate the dynamic behavior of IC-engines simulation models are being applied at an ever increasing rate. The simulation models used of until now, were calculation models for an individual valve train. These models were not capable of analysing the interactions of bending and torsional vibrations between individual valve trains of a complete camshaft. For this reason a calculation model has been developed which comprises the entire valve train from the drive gear of the camshaft to the last valve. The camshaft is represented by a combined bending and torsional vibration model with elastic bearings. Combining this model with a camshaft-drive-system simulation model, it is possible to record interactions between the individual valve trains of a complete cylinder head. Bending and torsional effects in the camshaft and effects resulting from the chain or belt forces are taken into consideration.

One goal of this paper is the description of the advanced simulation model for the complete valve train. The capabilities of calculation will be discussed and the accuracy of the model will be demonstrated by comparisons with measured signals. The second goal is to give some special answers concerning incorrectly operating valve trains. Characteristic influences of angular or bending vibrations of the camshaft on the dynamic behaviour of the individual valve train will be demonstrated and analysed by calculations.