Lutz Stiegler

Overview of Current Continuously Variable Valve Lift Systems for Four-Stroke Spark-Ignition Engines and the Criteria for their Design Ratings

This paper provides an up-to-date overview of variable valve control systems that permit valve lift and opening time to be continuously varied, and of the choice of the valve lift function needed for engine load control. In recent years in particular, following the introduction on a volume production scale of a system with continuously variable valve lift, development activity on valve control systems of this kind has been stepped up considerably. This overview refers to the principal systems known to be under development and to recent patent applications. It describes the design criteria and ratings needed for continuously variable valve lift systems, discusses the criteria that are of importance if such valve control systems are to be adopted on production vehicles and indicates the factors that have to be taken into account before the severe requirements imposed by series-production engines can be satisfied. Design details are described to indicate the potential that exists for these systems to be applied to high-volume production engines.

Single-cylinder engine as a tool for developing new combustion processes

In the race to perfect the combustion process of tomorrow engine developers are focusing on homogeneous spark-ignition and diesel systems with stratified spark-ignition combustion processes along with a variety of technologies. IAV is continually optimising its development processes so as to ensure the best possible preparation for the demands of customer projects. One example is IAV’s single-cylinder engine as a tool for developing new combustion methods. Studies into the capability of applying results to the multiple-cylinder engine as well as the adaptation of a universal control unit and special measuring techniques make the single-cylinder engine a valuable component in an efficient process chain.

Einzylindermotor als Werkzeug zur Entwicklung neuer Brennverfahren

Im Wettlauf um das motorische Brennverfahren der Zukunft stehen homogene Otto- und Dieselverfahren, geschichtete Ottobrennverfahren und unterschiedliche Technologien im Fokus der Motorentwickler. Die IAV treibt die Optimierung der Entwicklungsprozesse stetig voran, um in Kundenprojekten optimal auf die jeweiligen Anforderungen vorbereitet zu sein. Ein Beispiel ist der Einzylindermotor der IAV als Entwicklungswerkzeug fur neue Brennverfahren. Die Ubertragbarkeit der Resultate auf den Mehrzylindermotor sowie die Adaption von Universalsteuergerat und spezieller Messtechnik machen den Einzylindermotor zum wertvollen Bestandteil einer effizienten Prozesskette.