Exhaust gas purification system of internal combustion engine

摘要

In a system for purifying exhaust gas of an internal combustion engine having a DPF installed in an exhaust system for capturing particulates in the exhaust gas in which DPF regeneration is permitted when a detected engine coolant temperature TW is equal to or greater than a first threshold value (S22, S24), the first threshold value is changed to a second threshold value that is set to be lower than the first threshold value, when an amount of particulates is equal to or greater than a predetermined value that indicates an excessive limit (S26); and the regeneration is permitted when the detected engine coolant temperature TW is equal to or greater than the second threshold value (S24).