Analytical synthesis and computer-aided kinematic analysis of a continuously variable valve lift mechanism

This paper presents an original continuously variable intake valve lift mechanism designed for the automotive spark ignition engines. The paper first presents the analytical kinematic synthesis of the variable intake valve lift mechanism, which consists in finding out the required intake cam profile starting from an imposed intake valve lift law. Then, by using the obtained cam profile, a computer-aided kinematic analysis of the variable intake valve lift mechanism is performed using commercial CAD software. The accuracy of the motion conversion performed with CAD software is validated by checking the degree of correlation between the resulted intake valve lift law and the imposed law used when performing the analytical synthesis. The goals of the kinematic analysis are first to find the partial laws of the intake valve lift, corresponding to the engine part loads and second, to find the transfer functions of the elements used to command the mechanism, i.e. the dependency between these elements and the intake valve lift law. The designed variable intake valve lift mechanism is successfully operated on an engine prototype and proved its energetic improvement potential.

[1]  Shinichi Kiga,et al.  Development of Innovative Variable Valve Event and Lift (VVEL) System , 2008 .

[2]  Adrian Clenci,et al.  Some aspects concerning the combination of downsizing with turbocharging, variable compression ratio, and variable intake valve lift , 2007 .

[3]  Dojoong Kim,et al.  Kinematic design and analysis of a four-bar linkage-type continuously variable valve actuation mechanism , 2012 .

[4]  Nicolae-Doru Stănescu,et al.  Classical and Modern Approaches in the Theory of Mechanisms , 2017 .

[5]  Harold A. Rothbart,et al.  Cam design handbook , 2004 .

[6]  Rudolf Flierl,et al.  Improvements to a Four Cylinder Gasoline Engine Through the Fully Variable Valve Lift and Timing System UniValve , 2006 .

[7]  Morgan Heikal,et al.  Low intake valve lift in a port fuel-injected engine , 2009 .

[8]  Carmelina Abagnale,et al.  New mechanical variable valve actuation systems for motorcycle engines , 2015 .

[9]  F. Millo,et al.  Numerical and experimental investigation on combustion characteristics of a spark ignition engine with an early intake valve closing load control , 2014 .

[10]  Jie Guo,et al.  Investigation of dynamic characteristics of a valve train system , 2011 .

[11]  Adrian Clenci,et al.  A CFD (computational fluid dynamics) study on the effects of operating an engine with low intake valve lift at idle corresponding speed , 2014 .

[12]  Heinz Ulbrich,et al.  Dynamic Analysis of the Audi Valvelift System , 2010 .

[13]  Nakamura Makoto,et al.  A Study of a Multiple-link Continuously Variable Valve Event and Lift (VVEL) System , 2008 .

[14]  Rodica Niculescu,et al.  Idle Operation with Low Intake Valve Lift in a Port Fuel Injected Engine , 2013 .

[15]  Ferdinand Freudenstein,et al.  Kinematic Synthesis of Linkages , 1965 .

[16]  Fumihiko Ito,et al.  Development of a Custom Integrated Circuit for Continuously Variable Valve Lift Mechanism System Control , 2008 .