Exhaust gas heating system for in-cylinder injection internal combustion engine

摘要

An exhaust gas heating system for an in-cylinder injection internal combustion engine is disclosed. The system includes a fuel injection device for injecting fuel directly into a combustion chamber of the engine, a spark plug for subjecting fuel, which has been injected as primary fuel from the injection device, to spark ignition such that the primary fuel undergoes primary combustion, an exhaust gas purification device arranged in an exhaust passage of the engine, a purification device temperature computing unit for determining a temperature of the purification device by detecting or estimating the temperature of the purification device, and an additional fuel injection control unit for controlling the injection device when the purification device is found to require activation from the temperature determined by the computing unit, such that an injection of fuel as additional fuel is performed during a flame lasting duration that a flame of the primary combustion remains. The control unit includes an injection timing setting unit for setting an injection start time of the additional fuel on a basis of a parameter which affects the flame lasting duration.