Search Results

Nowadays fully-flexible valve control is considered to be the most promising improvement measure for SI-engines besides or in combination with direct fuel injection. Engine producers investigate the readability of a huge variety of systems, but at present only simple systems are applied in production engines, which fulfil only a part of the requirements. Although hydraulic systems are very suitable for finding optimum valve control strategies, the advantages of mechanical systems for series requirements are obvious. Thus, after development of mechanical phase shifters and mechanical systems with up to three selectable valve lift curves, it seems to be logical to use the advantages and experiences with mechanical systems to realize a fully-flexible valve control as well. In this context a new mechanical valve gear called delta-st (delta-st = delta control) for continuous adjustment of valve lift, opening duration and phase angle was developed at the University of Karlsruhe, Germany.