EXHAUST-GAS PURIFYING SYSTEM FOR INTERNAL-COMBUSTION ENGINE

摘要

In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (15), an exhaust purification catalyst (13), and a particulate filter (14) are arranged. At the time of engine operation, the amplitude of change of the concentration of hydrocarbons which flow into the exhaust purification catalyst (13) is made to become within a predetermined range of amplitude by control of the injection amount of hydrocarbons from the hydrocarbon feed valve (15). When the temperature of the particulate filter (14) is to be raised to be regeneration temperature, the injection amount of hydrocarbons is increased and thereby the pass through amount of hydrocarbons which pass through the exhaust purification catalyst (13) is increased.