Exhaust emission control device of internal combustion engine

An exhaust gas purification device of an internal combustion engine wherein an exhaust control valve is arranged a predetermined distance away from an outlet of an engine exhaust port inside an exhaust passage connected to the outlet of the exhaust port;

• when it is judged that the amount of unburned hydrocarbons exhausted into the atmosphere is to be reduced, the exhaust control valve is substantially fully closed and, in addition to burning the main fuel injected into the combustion chamber under excess air to generate engine output, auxiliary fuel is additionally injected into the combustion chamber at a predetermined timing in the expansion stroke or exhaust stroke where the auxiliary fuel can be burned so that the amount of unburned hydrocarbons produced in the combustion chamber is reduced and the oxidizing reaction of hydrocarbons in the exhaust port and the exhaust passage upstream of the exhaust control valve is promoted;
• and when the exhaust control valve is substantially fully closed, the amount of injection of main fuel is increased compared with the case where the exhaust control valve is fully opened under the same engine operating conditions.