| 摘要 |
An internal combustion engine wherein an exhaust purification catalyst (13) and hydrocarbon feed valve (15) are arranged in an engine exhaust passage and wherein the NO x which is contained in the exhaust gas is removed by injection of hydrocarbons from the hydrocarbon feed valve (15) by a predetermined period. Hydrocarbons are injected from the hydrocarbon feed valve (15) toward the upstream side of the engine exhaust passage. When hydrocarbons are injected from the hydrocarbon feed valve (15) by a predetermined period, the injection pressure of the hydrocarbons is made to gradually fall from injection start to injection end in the injection time period of each injection. |
