Fully Variable Valve Control: A Geometric Approach

Variable valve timing (VVT) and variable valve lift (VVL) are used to improve the performance, fuel economy and to reduce emissions of a combustion engine. Recently these issues have assumed increasing importance. Here we will combine VVT and VVL in a unified concept of variable valve control (VVC). We present a mechanical solution to fully variable valve control. The cam consists of two symmetric parts that slide on the camshaft; this way the system can provide a continuum of cam characteristics to meet a wide range of engine requirements.