Patent ID: 7832197

Claim:
A method of controlling a diesel engine including a combustion chamber, the engine coupled to an aftertreatment device configured to treat emissions from the diesel engine, a cylinder of the engine having an intake valve for passing air into the combustion chamber, and an exhaust valve for passing exhaust gas out of the combustion chamber, comprising: performing at least one combustion in the combustion chamber at a first exhaust valve closing timing and a first intake valve opening timing; if temperature of the exhaust gas is equal to or below a preselected temperature threshold, performing at least one combustion in the combustion chamber at a second, advanced exhaust valve closing timing and a second, retarded intake valve opening timing to thereby increase an internal exhaust gas recirculation and the temperature of the exhaust gas emitted by the diesel engine; where an advancement amount of the second exhaust valve closing timing and a retard amount of the second intake valve opening timing are equal; and if an external exhaust gas recirculation rate is below a preselected value, performing at least one combustion in the combustion chamber at a third, advanced exhaust valve closing timing to thereby increase the internal exhaust gas recirculation.