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Optimizing the Opening Period and the Timing of Intake and Exhaust Valves to Improve Engine Performance in a Supermilage Vehicle
ISSN: 0148-7191, e-ISSN: 2688-3627
Published November 17, 2015 by Society of Automotive Engineers of Japan in Japan
Annotation ability available
To improve engine torque and specific fuel consumption in a supermilage vehicle, we experimentally adjusted the valve lift and opening period in rocker arms, testing various follower configurations and adjust screws. Using the follower configuration in a commercially-available rocker arm, we compared 4 different levels of valve lift and opening period in the intake, and 4 different levels in the exhaust, making 16 combinations. Then, utilizing 5 kinds of modified follower configurations of the rocker arms in the intake, and 3 in the exhaust, we also compared 24 combinations (including the commercially-available follower configurations). We tested our experimental supermilage engine under full-load at 2000 to 4500rpm, simulating powering a supermilage vehicle. Results indicated that (1) with a commercially-available follower configuration of the rocker arm, specific fuel consumption decreased when setting both the open timing in the intake valve, and the close timing in the exhaust valve, at or near the top dead center (TDC), while decreasing overlap period of intake and exhaust valves. (2) With the modified follower configurations of the rocker arms, engine torque increased while specific fuel consumption decreased, when setting both the open timing in the intake valve and the close timing in the exhaust valve at or near the TDC, and the close timing in the intake valve at or near the bottom dead center (BDC), and the open timing in the exhaust valve at or near BDC, or the early opening timing in the exhaust valve.
CitationGoto, K., Noda, S., Nakashima, K., and Murakami, Y., "Optimizing the Opening Period and the Timing of Intake and Exhaust Valves to Improve Engine Performance in a Supermilage Vehicle," SAE Technical Paper 2015-32-0742, 2015, https://doi.org/10.4271/2015-32-0742.
- Takahashi , M. , Kano , T. , Yamada , T. , Ueura , H. , Kawasaki , T. and Hosokawa , F. Development of New 2.0-Liter Gasoline Engine with Valvematic System Toyota Technical Review 56 1 12 19 2008
- Seko , K. , Hayashi , A. and Nakajima , M. Achievement of Enhanced Fuel Economy via i-VTEC Intake Valve Closure Delay Mechanism Honda R&D Technical Review 18 1 88 93 2006
- Hara , S. , Nakajima , Y. and Nagumo , S. Effect of Intake-Valve Closing Timing on Spark-Ignition Engine Combustion SAE Technical Paper 850074 1985 10.4271/850074
- Nagumo , S. and Hara , S. Study of Fuel Economy Improvement through Control of Intake Valve Closing Timing -Cause of Combustion Deterioration and Improvement Combustion- Transactions of Society of Automotive Engineers of Japan 26 4 17 23 1995
- Umiyama , H. , Shimizu , K. , Kubodera , M. and Sono , H. A Study of Non-Throttling Engine with Early Intake Valve Closing Mechanism Transactions of Society of Automotive Engineers of Japan 24 4 23 28 1993
- Kumano , K. , Yamauchi , S. , Sukegawa , Y. and Kihara , Y. Analysis of In-Cylinder Phenomena under Low Valve Lift Operation in DI Gasoline Engines Transactions of Society of Automotive Engineers of Japan 41 2 277 282 2010
- Ibara , T. , Iida , M. and Foster , D. E. Basic Characteristics of Gasoline Fueled HCCI Using Negative Valve Overlap about intake valve timing and combustion Yamaha Motor Technical Review 43 1 11 2007
- Ma , T. H. Effect of Variable Engine Valve Timing on Fuel Economy SAE Technical Paper 880390 1988 10.4271/880390
- David , J. W. , Wei , Y. and Covey , J. A. Optimal Rocker Arm Design in High Speed Internal Combustion Engines SAE Technical Paper 942501 1994 10.4271/942501