Development of a Timing Chain Drive Model for a High Speed Gasoline Engine 2011-01-0401
Engine efficiency and optimization are key aspects for automotive manufacturers. Lamborghini has particularly focus attention for reduction of time to market building up a synergic approach for new component's development using simulation, Know-how experiences, engine engineering expertise and experimental validation. In particular to reach the best results in the shortest time it is used, in the preliminary stage of development, a massive support of simulation analysis.
In the Lamborghini approach analysis and simulation has become key aspects during concept and development of timing drives. This type of activity is used to support the development of better chain timing drives focusing on improving durability, lower friction, less noise and reduced cost in less time than conventional trial and processes.
Even during the concept design phase it is useful to use a mathematical model to calculate dynamic forces and motions of a chain drive. These models are used to assess in detail the choice of drive layout, to check that component load limits are not exceeded and to make a first choice of the tensioner settings. Later, when the first prototype engines are available, measurements of timing drive sprocket motion, tensioner motion and tensioner force are typically taken. At this stage the model can be correlated to the measured data and then the correlated model can then be used to explore the potential for improvements to the timing drive during later phases of engine development.
This paper describes the correlation of a mathematical model of a complex timing chain drive for a Lamborghini V12 gasoline engine to measurements made on a prototype engine. The depth of model required and the choice of stiffness and damping values needed to give excellent agreement between calculations and measured data are discussed.