EXHAUST EMISSION CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To prevent a particulate filter from being thermally deteriorated by combustion heat of particulates deposited on the surface of the particulate filter. SOLUTION: The particulates in exhaust emission are oxidized and removed on the particulate filter 22. When the temperature of the particulate filter becomes higher than a preset temperature, the quantity of exhaust emission flowing into the particulate filter is made larger than a first threshold, or smaller than a second threshold smaller than the first threshold.