In the pursuit of design and development of efficient, reliable and durable system and components for modern engines, there is a need to understand complications involved in building mathematical models for simulation. Valve train and timing drive systems are having higher rankings for addressing these attributes. Hence, a new comprehensive multi body dynamics model is built and equations are solved by state-variable approach.
Model developed is validated and in order to probe into details of Hydraulic Lash Adjuster (HLA) behavior and coupled analysis of timing chain drive systems for valve train system, simulation is carried out to freeze design options. Engine timing drives used in engines are one of the most critical systems. Timing chains are preferred widely in modern high speed engines as compared to timing belts and gear drives. In spite of advantages of chain drive systems, their complex dynamic behavior is not well researched. The major objective of the current work is to design & develop timing chain drive and valve train system for a high speed three cylinder diesel engine and investigate about its durability.
In this research work, dynamic model of type-2 valve train with HLA and chain drive with hydraulically operated tensioners is built in GT valve train software. The final goal is to optimize the valve train and timing system performance by simulation. The results related to timing chain analysis are expressed in terms of parameters such as contact forces, normal forces between different components and link tension etc.
The effectiveness of this model calibration technique was confirmed through comparison of unit dynamic characteristics in an excitation test and a calibrated simulation. The proposed simulation process is validated experimentally and has shown considerable reduction in development time with improved robustness.