Patent ID: 7730721

Claim:
An exhaust gas purification device of internal combustion engine comprising: an exhaust passage for guiding an exhaust gas discharged from the engine to outside; a catalyst provided in said exhaust passage; an injection path having a proximal end portion that extends outward from a part of said exhaust passage, which is located in an upstream of said catalyst; an additive injection valve installed in said injection path and supplying an additive to said catalyst through the injection path; an inflow path for allowing a part of the exhaust gas flowing in said exhaust passage to enter said injection path, said inflow path being formed by expanding only a wall surface of the exhaust passage of a crotch portion between the proximal end portion of the injection path and a part of the exhaust passage, which is located in the immediate upstream of the proximal end portion; and a scavenging-flow forming means for forming the exhaust gas entering said injection path through said inflow path, into a scavenging flow for cleaning the inside of the injection path.