Electrohydraulic Valve-trains for Direct Injection Compression Ignition Camless

摘要

Most existing variable-timing systems, which perform a camshaft phase shift or aswitch to another cam lobe profile, offer measurable improvements at some engine operating points. A microprocessor controlled careless valvetrain, which continuously adjusts the parameters of valve motion with changing operating conditions, offers much more flexibility and potential benefits as they allow more complete optimization of engine events over the entire operating speed range. However, such devices can be complex, bulky, and relatively expensive, so their applications tend to be limited. The goal of this project is to investigate the technical challenges, and develop the enabling valve design and control capability for the careless operation of small compression ignition direct injection (CIDI) engines. In this project the feasibility of such type of valvetrain has been investigated. The operation of the system to fire a single cylinder in a careless 2.0 liter 4 cylinder S1 engine has been demonstrated with wide opened throttle. Groundwork on analytical modeling and initial experimental testing has been conducted to address some of the known critical issues and discover new technical challenges for the electrohydraulic valvetrain. This report presents the results obtained from this Phase I investigation.