The Optimal Strategies for Improving Efficiency in Camless Engines

Abstract:

In this paper, an unthrottled camless engine model, which equipped electromagnetic valvetrain (EMV), has been built for performance simulation of engine dynamics. The combination of the techniques of cylinder deactivation (CDA) and variable valve timing (VVT) has been examined for different engine speeds and engine loads. The results concluded that the mode of two-cylinder deactivation considerably improves the fuel consumption at low engine load. Meanwhile, the one-cylinder deactivation mode is an optimal fuel economy mode for medium engine load. The normal engine mode fairly satisfies the driving torque and fuel economy in a vehicle, and thus it fits the optimal mode for the full loads. Additionally, the results also show that the optimal intake valve closing (IVC) timing for different engine speeds and loads. The IVC timing depends on engine speed linearly while the optimal IVC timing insignificantly changes at different engine loads when CDA is applied. By the determined CDA-VVT strategy, a camless unthrottled engine can maintain high efficiency operation for different speeds and loads.

• Periodical: Applied Mechanics and Materials (Volume 145)
• Pages: 83-87
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.145.83
• Online since: December 2011
• Authors: Yao Jung Shiao, Ly Vinh Dat
• Keywords: Camless Engine, Cylinder Deactivation (CDA), Electromagnetic Valve Train (EMV), Variable Valve Timing (VVT)

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