Patent ID: 7669578
Filing Date: 2010-03-02
Classification: F02B,F02D,F02M,Y02T

Abstract:
1. A method of operating an internal combustion engine having a combustion chamber with a piston and a spark plug, comprising: during a first mode, bringing the temperature of the combustion chamber to auto-ignition temperature by adjusting engine operating conditions and producing auto-ignition in said combustion chamber without requiring spark from said spark plug; and during a second mode, bringing the temperature of the combustion chamber close to auto-ignition temperature by adjusting engine operating conditions, forming a small cloud of stratified air-fuel mixture near said spark plug, igniting said small cloud of stratified air-fuel mixture by a spark from said spark plug, and then causing cylinder pressure to rise, thereby producing auto-ignition at other sites in said combustion chamber; wherein said first mode is implemented in a first operating range and said second mode is implemented only in a second operating range where at least one of engine speed and load is lower than a respective one of engine speed and load in said first operating range, the method further comprising producing substantially homogenous air-fuel mixture at said other sites in said combustion chamber by providing fuel into said combustion chamber in at least an intake stroke of said piston, and wherein said small cloud of stratified air-fuel mixture is formed by providing fuel into said combustion chamber in at least a compression stroke of said piston, wherein said providing fuel into said combustion chamber in at least a compression stroke includes providing a specific amount of fuel into said combustion chamber during said compression stroke, which is independent from said engine load.