Design evaluation of a follower cam with variable valve lift mechanism

Abstract

PurposeThe purpose of this paper is to present a methodology for design, analysis and evaluation of cam‐follower systems used for the control of valve movement in internal combustion engines. The strategy begins with the inverse engineering of existing motor parts, designing them with the CATIA CAD Software and consequentially the created assembly is simulated using real time conditions in SimDesigner software, with the Adams Solver.Design/methodology/approachThe cam profile is generated and the kinematic and dynamic analysis of the variable valve mechanism is presented. The whole mechanism is verified in a dynamics analysis to check the validity of the criteria for the follower‐cam system design. Comparisons with standard profiles of motion were made, while it is also evaluated in an experimental device, where the actual valve displacement was measured.FindingsThe variable valve lift mechanism is designed to have maximum lifts greater than the lift of the conventional mechanism, with the geometrical constraints, profile of forces, velocities and accelerations to be better, in terms of stresses and work required, than the design of conventional mechanisms.Originality/valueThe novelty of the paper is consisted in presenting an integrated simulation methodology in order to precisely model, in component and assembly basis, the follower cam mechanisms with variable valve lift, and using the available software to perform the kinematic and dynamic analysis. The proposed simulation methodology can be easily adapted by a design engineer to model and to analyzed kinematically and dynamically moving components and assemblies found in internal combustion engines and not only.