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Kinematic Analysis of a Continuously Variable Valve Actuation Mechanism with Movable Second Cam Center  

Kim, Do-Joong (Department of Mechanical and Automotive Engineering, University of Ulsan)
Kim, Yong-Hyun (Institute of e-Vehicle Technology, University of Ulsan)
Publication Information
Transactions of the Korean Society of Automotive Engineers / v.17, no.5, 2009 , pp. 7-15 More about this Journal
Abstract
This paper introduces a new variable valve actuation mechanism with movable second cam center. Valve lift and open duration can be continuously varied according to engine speed and load conditions. A new method to analyze the kinematic relations between the first and second cam profiles and valve motion are also introduced. Because of rocker motion of the second cam, conventional motion conversion program could not be used in this problem. An example shows continuous variations of valve motion and adequate ramp incorporation throughout all valve lift modes. Valve acceleration profile at the high lift mode is similar to that of conventional valvetrains. Contact geometry analysis of the mechanism gives basic information on the load conditions between the components.
Keywords
Engine valve train; Variable valve actuation; Continuously variable valve lift; Kinematics of valve train; Second cam design;
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