Abstract

Method and system embody a valve timing strategy to control the autoignition timing of a four stroke internal combustion engine (10) operated in an HCCI mode at different engine operating conditions such as different engine speed and torque. A particular valve timing strategy varies lift timing of the intake valve (20) relative to the exhaust valve (28), or vice versa, and relative to top dead center in response to a change in engine torque, for example, to vary amount of trapped residual burned gas in the combustion chamber (12) flowing to an intake or exhaust port (16,18) and back to the combustion chamber during which the residual gas is cooled. Control of the flow of residual gas between the combustion chamber and intake or exhaust port and thus its temperature by the valve timing strategy, in turn, is used to control the temperature of the fresh air/residual gas/fuel mixture in the combustion chamber (12) and thus autoignition timing in response to a change in engine torque.

Other References

• SAE 2000-01-1837; “Innovative Ultra-low NOx Controlled Auto-Ignition Combustin Process for Gasoline Engines: the 4-SPACE Project”; Jacques Lavy et al.
• SAE 2000-01-2870; “Demonstration of HCCI Using a Single Cylinder Four-Stroke SI Engine with Modified Valve Timing”, George Kontarakis et al.
• SAE 2002-01-0110; “Cycle to Cycle Variations: Their Influence on Cycle Resolved Gas Temperature and Unburned Hydrocarbons from a Camless Gasoline Compression Ignition Engine”; Lucien Koopmans et al.
• SAE 982483; “The Knocking Syndrome—Its Cure and Its Potential” Jurgen Willand et al.
• SAE 2001-01-3601; “A Four Stroke Camless Engine, Operated in Homogeneous Charge Compression Ignition Mode with Commercial Gasoline”; Lucien Koopmans et al.
• SAE 2000-01-0251; “Controlled Combustion in an IC-Engine with a Fully Variable Valve Train”; Don Law et al.
• SAE 2001-01-3608; “Research and Development of Controlled Auto-Ignition (CAI) Combustion in a 4-Stroke Multi-Cylinder Gasoline Engine”; Jian Li et al.
• SAE 2002-01-0420; “Performance and Analysis of a 4-Stroke Multi-Cylinder Gasoline Engine with CAI Combustion”; Hua Zhao et al.
• SAE 2002-01-0422; “Variable Valve Actuated Controlled Auto-Ignition: Speed Load Maps and Strategic Regimes of Operation”; Jeff Allen et al.