Patent ID: 8528320

Claim:
A system for exhaust gas purification, comprising, in the following order from an upstream side of an exhaust passage of an internal combustion engine: a device for direct injection into an exhaust pipe; an oxidation catalyst; at least one of a catalyst for NOx removal and a catalyzed diesel particulate filter, wherein a support of the oxidation catalyst is formed of a metallic material or a material having a specific heat not higher than that of a metallic material into a structure having a function of mixing exhaust gas; an exhaust gas purification control unit which performs: in-exhaust pipe direct injection in a predetermined first supply amount for raising a temperature of the oxidation catalyst when a first index temperature indicative of a temperature of the oxidation catalyst is above a first judgment temperature; in-exhaust pipe direct injection in a predetermined second supply amount for raising a temperature of the exhaust gas when the first index temperature is above a second judgment temperature; and in-exhaust pipe direct injection in a predetermined third supply amount for performing a corresponding one of regeneration by NOx removal and forced regeneration by particulate matter removal when a second index temperature indicative of a temperature of the at least one catalyst for NOx removal and the catalyzed diesel particulate filter reaches a third judgment temperature.