Design and Development of Variable Valve Actuation (VVA) Mechanism Concept for Multi-Cylinder Engine
The desire for higher fuel economy, improved performance and driveability expectations of customers from engines are gradually increasing along with stringent emission regulations set by the government. Many original engine manufacturing companies are prompted to consider the application of higher function variable valve actuation mechanisms in their next generation vehicles as a solution. The VVA is a generalized term used to describe any mechanism or method that can alter the shape or timing of a valve lift event within an internal combustion engine. The VVA allows lift, duration or timing (in various combinations) of the intake and/or exhaust valves to be changed while the engine is in operation. Engine designers are prompted to consider Variable Valve Actuation (VVA) system because of the inherent compromises with fixed valve events. The major goal of a VVA engine is to control the amount of air inducted into the engine which is a direct measure of torque.