This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Application of a Variable Valve Event and Timing System to Automotive Engines
Technical Paper
2000-01-1224
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Event:
SAE 2000 World Congress
Language:
English
Abstract
This paper describes a new variable valve system that enables continuous control of valve events, i.e. time periods when the valve is open. In this system, valve events are controlled by varying the camshaft angular speed by means of an offset between the center of the camshaft and that of the medium member that transfers crankshaft torque to the camshaft. The medium member, a rotating disk, has a drive pin to enable the transfer of torque. The system has a mechanism that produces an offset between the center of the rotating disk and that of the camshaft as well as an actuator that drives the mechanism. This makes it possible to develop a compact system that can be installed in existing DOHC direct-acting valve train engines without making any major cylinder head modifications. Test results verified that valve events could be broadly controlled through the use of an electronically controlled hydraulic actuator, and that control could be achieved up to the low speed region with the use of engine oil pressure.
The system was applied to a 4-cylinder, 1.6L engine, and test results showed that torque improved from 10 to 15% and by 10% at maximum power. We also confirmed that both fuel economy and exhaust emissions at part-load were substantially improved when using the system.
Recommended Content
| Technical Paper | VAST: A New Variable Valve Timing System for Vehicle Engines |
| Journal Article | Design of an Electric Variable CAM Phaser Controller |
| Technical Paper | Intelligent Simplification-Ways Towards Improved Fuel Economy |
Authors
Citation
Hara, S., Hidaka, A., Tomisawa, N., Nakamura, M. et al., "Application of a Variable Valve Event and Timing System to Automotive Engines," SAE Technical Paper 2000-01-1224, 2000, https://doi.org/10.4271/2000-01-1224.Also In
References
- Ahmad T. Theobald M. A. “A Survey of Variable Valve Actuation Technology” SAE Paper 891674
- Maekawa K. Ohsawa N. Akasaka A. “Development of a Valve Timing Control System,” SAE Paper 890680
- Inoue K. Nagahiro K. Ajiki Y. Kishi N. “A High Power, Wide Torque Range, Efficient Engine with a Newly Developed Variable-Valve-Lift and -Timing Mechanism” SAE Paper 890675
- Hara S. Kumagai K. Matsumoto Y. “Application of a Valve Lift and Timing Control System to an Automotive Engine” SAE Paper 890681
- Pierik R. J. Gecim B. A. “A Low-Friction Variable-Valve-Actuation Device, Part 1:Mechanism Description and Friction Measurements” SAE Paper 970338
- Urata Y. Umiyama H. Shimizu K. Hujiyoshi Y. Sono H. Hukuo K. “A Study of Vehicle Equipped with Non-Throttling S.I. Engine with Early Intake Valve Closing Mechanism” SAE Paper 930820
- Schechter M. M. Levin M. B. “Camless Engine” SAE Paper 960581
- Kreuter P. Heuser P. Schebitz M. “Strategies to Improve SI-Engine Performance by Means of Variable Intake Lift, Timing and Duration” SAE Paper 920449
- Parker D. A. Kendrick M. “B-1-11-A Camshaft with Variable Lift-Rotation Characteristics: Theoretical Properties and Application to the Valve Gear of a Multicylinder Piston Engine” FISITA 1974
- “New MG: K-series Too Big for Its Boost? Try New Boots” AUTOCAR 8 March 1995
- Griffiths P. J. Mistry K. N. “Variable Valve Timing for Fuel Economy Improvement-The Mitchell System” SAE Paper 880392
- Lancefield T. M. Gayler R. J. Chattopadhay A. “The Practical Application and Effects of a Variable Event Valve Timing System” SAE Paper 930825
- Hannibal W. Bertsch A. “VAST:A New Variable Valve Timing System for Vehicle Engines” SAE Paper 980769