This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Variable Valve Timing Mechanism with Control Ramp
Annotation ability available
Sector:
Language:
English
Abstract
A new fully mechanical valve timing mechanism for continuous control of valve lift, duration and phase angle has been developed. Any valve lift and duration between zero and the maximum value may be obtained by rotating an adjustable control shaft and ramp. Total valve deactivation is possible and intake valve throttling may be used.
The operation principle and several applications of the mechanism are presented. The kinematics and dynamics of the mechanism have been studied and the critical forces and stresses have been calculated. Also the tribology of the mechanism is dealt with to check possible lubrication problems. Simulation has been used to find the dynamic properties and loads of the mechanism.
The mechanism has been tested in two single cylinder intake valve prototypes using the two-lever rocker and drag lever principles. The mechanism has been functioning in the expected way but the performed durability tests indicate that certain redesign and further testing of the mechanism is necessary.
Recommended Content
Authors
Topic
Citation
Järvi, I., "Variable Valve Timing Mechanism with Control Ramp," SAE Technical Paper 980768, 1998, https://doi.org/10.4271/980768.Also In
References
- Altman, Werner 1976
- Stidworthy, Frederick Michael 1988
- Berg, Mario Kachel, Gerhardt Kuhn, Peter Mechanical Fully-Flexible Valve Control with delta-st SAE Paper 970251 1997
- Allen, Jeffrey 1995
- Cukovich, Mark S. 1995
- Hamrock, Bernard J. Fundamentals of Fluid Film Lubrication 1994 McGraw-Hill, Inc.