| abstract |
An exhaust gas purification system for an internal combustion engine, the system having a selective reduction type NOx catalyst and a particulate filter that are arranged in an exhaust path of the engine, wherein discharge of ammonia from the selective reduction type NOx catalyst is suppressed. When execution conditions for filter temperature raising control are established (S101), the exhaust gas purification system stops supply of urea to the selective reduction type NOx catalyst performed by urea supply means (S102), and when a predetermined time period has passed after a time point at which the supply of the urea to the selective reduction type NOx catalyst is stopped, the exhaust gas purification system executes the filter temperature raising control by using filter temperature raising means (S103, S104). |