Patent ID: 7168396
Filing Date: 2007-01-30
Classification: F01L,F02D,Y02T

Abstract:
1. A method of operating a compression ignition engine that powers a motor vehicle and has a processor-based engine control system controlling both a fueling system for fueling the engine and a variable valve actuation mechanism that varies operation of intake valves that open and close an intake system to individual engine cylinders, the method comprising: processing engine speed and engine load data using one or more maps that correlate various combinations of engine speed and engine load with corresponding fueling data to develop fueling data for fueling the engine and processing the developed fueling data and engine speed data using one or more maps that correlate various combinations of engine speed and fueling with corresponding intake valve operation data to develop intake valve operation data for controlling intake valve operation for a cylinder during an engine cycle to endow the cylinder with an effective compression ratio (ECR) appropriate to current engine operation for causing auto-ignition to occur near or at top dead center in the engine cycle; during a compression upstroke, fueling the cylinder according to the developed fueling data and controlling intake valve operation for the cylinder according to the developed intake valve operation data to cause fuel in the cylinder to mix with charge air that has entered the cylinder from the intake system during an immediately preceding intake downstroke and early portion of the compression upstroke; and then increasingly compressing the mixture to the point of auto-ignition near or at top dead center.