| 摘要 |
An ECU (30) performs PM removal control, in which the bed temperature of a DPF (22) is adjusted to a target bed temperature through addition of unburned fuel to exhaust gas. In the PM removal control, the ECU (30) learns a learned value of a fuel addition amount by which the difference between the bed temperature and the target bed temperature of the DPF (22) is corrected. When the determination in step S510 is positive, in other words, when it is determined that the flow of the exhaust gas to the DPF (22) is in a steady state, the ECU (30) stores a correction value K as a steady state learned value Ka in step S520. When the determination in step S510 is negative, in other words, when it is determined that the flow of the exhaust gas is in a transient state, the ECU (30) stores the correction value K as a transient state learned value Kb in step S530. In the PM removal control, the ECU (30) reflects the transient state learned value Kb in the fuel addition amount. NOx reduction control is carried out based only on the steady state learned value Ka. |
