| 摘要 |
The purpose of the present invention is, in an exhaust purification device for an internal combustion engine provided with an oxidation catalyst and a selective reduction catalyst in the exhaust passage, to increase the NOx purification rate of the exhaust purification device as a whole. A control unit for controlling the amount of fuel supplied to the oxidation catalyst: executes a first control for controlling the amount of fuel supplied so that reduction of NOx by the oxidation catalyst is performed when the temperature of the oxidation catalyst is in a specified temperature range at or above the active temperature thereof and the selective reduction catalyst is in an inactive state; and executes a second control for controlling the amount of fuel supplied so as to raise the temperature of the exhaust flowing into the selective reduction catalyst using the oxidation of the fuel by the oxidation catalyst regardless of the NOx purification rate by the selective reduction catalyst when the temperature of the oxidation catalyst exceeds a specified temperature range and the selective reduction catalyst is in an inactive state. |
