Patent ID: 8171725

Claim:
A control method of an exhaust gas purification system provided with an exhaust gas purifier having an oxidation catalyst to purify components in an exhaust gas and a regeneration controller performing a regeneration control accompanied by a post injection in an in-cylinder fuel injection control to recover a purification ability of the exhaust gas purifier in an exhaust gas passage of an internal combustion engine, wherein in an exhaust gas temperature raising control at the regeneration control, performing a first exhaust gas temperature raising control using a multiple-stage delayed iniection, an air-intake throttling and an exhaust gas throttling without performing a post injection, when a temperature of the exhaust gas flowing into the exhaust gas purifier is lower than a predetermined value corresponding to an activation temperature of the oxidation catalyst, and performing a second exhaust gas temperature raising control using the post injection, the air-intake throttling, and the exhaust gas throttling in addition to the multiple-stage delayed injection, when the temperature of the exhaust gas flowing into the exhaust gas purifier is equal to or more than the predetermined value, so that an air-intake throttle amount for the first exhaust gas temperature raising control becomes larger than an air-intake throttle amount for the second exhaust gas temperature raising control.