EXHAUST PURIFICATION DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

An exhaust purification system of an internal combustion engine is provided with a hydrocarbon feed valve which is arranged in an engine exhaust passage and an exhaust purification catalyst for causing NO x which is contained in exhaust gas and reformed hydrocarbons to react. The exhaust purification catalyst has the property of reducing the NO x if making a concentration of inflowing hydrocarbons vibrate by within a predetermined range of amplitude and by within a predetermined range of period and has the property of the amount of storage of NO x increasing if making the vibration period of the concentration of hydrocarbons longer than a predetermined range. During the time period when hydrocarbons are being fed from the hydrocarbon feed valve within the predetermined range of amplitude and the predetermined range of period, if the amount of adsorption of hydrocarbons in the exhaust purification catalyst exceeds a predetermined judgment value of the adsorption amount, at least one control of control which reduces the amount of feed of hydrocarbons and control which lengthens the feed interval of hydrocarbons is performed.