EXHAUST PURIFICATION SYSTEM FOR INTERNAL COMBUSTION ENGINE

摘要

It is intended to provide an exhaust gas purification system for an internal combustion engine, which is capable of suppressing HC emission increase and raising the temperature of an exhaust gas purifier at an early stage while maintaining stable combustion during the warm-up operation such as immediately after the engine starting. The system is provided with: an air flow control unit 50 for reducing a flow rate of air supplied to the engine 1 to raise a temperature of the exhaust gas exhausted from the engine 1; and an activation timing control unit 52 for controlling a timing of activating the air flow control unit 50, and the activation timing control unit is configured to control the timing of activating the air flow control unit 50 so that a combustion state in the engine 1 does not become unstable when the air flow control unit 50 is activated and the air to be supplied to the engine 1 is reduced.