OPTIMIZATION OF VALVETRAIN MECHANISM FOR THREE CYLINDER TURBOCHARGED INTERCOOLED GASOLINE ENGINE

Present work descries the effect of in-cylinder pressure in turbocharged gasoline engine, on valvetrain analysis. Consideration of cylinder pressure gives corrected stresses and also it gives scope for reduction in moving masses in valvetrain. Reduction in moving mass and valve spring stiffness has significant impact in valvetrain kinematics & dynamics. These parameters are analysed in detail in this work. Initially, kinematic and dynamic analysis on the benchmark three cylinder naturally aspirated engine valve train is performed. The impacts of in cylinder pressure (P-?) on kinematic parameters are analysed. The boundary conditions are modified suitable to TCIC engine and the impact on valvetrain kinematic parameters such as valve lift, velocity, acceleration, contact stress between cam and follower at idle speed and high speed, inertia and spring force safety factor, dynamic valve lift and valve bouncing are analysed & tabulated. These analyses revealed that there is the scope to reduce the contact stresses by 5% at least. Further optimization of the valvetrain masses and stiffness to bring down the stress levels of turbocharged engine is performed. Valvetrain kinematic and dynamic analyses are being simulated in 1D analysis software AVL-EXCITE.