Abstract
During the past years advances in fuel efficiency of car engines did not result in the expectable reduction of the overall fuel consumption of new car generations. One reason is the increasing vehicle weight. In an overall-weight analysis of an auto-mobile the engine and as part of it, the crankcase represents a single component with a high weight reduction potential. The application of lightweight materials for new crankcase concepts implies comprehensive design considerations to achieve weight reductions as close as possible to the potential of the selected material. This paper discusses weight reduction strategies using lightweight materials and modern design approaches.
Different design concepts were investigated to ensure a stiff overall crankcase structure. FE analysis was conducted on deep-skirt concepts with standard bearing caps and alternatively with cast-in reinforcements and on bed-plate concepts with thick main bearing shells and optionally with reinforcing cast-in structures. The analysis takes static, dynamic and thermal loads into account and results in the peak firing pressure limits of each concept. The limits in combination with other relevant parameters are used to define the best-suited lightweight design concept for the specific structural requirements of each engine type.
The results show, that AVLs new lightweight design strategies allow a significant reduction of engine mass compared to conventional concepts and represent an important contribution to reduce the overall vehicle weight.