| 摘要 |
PROBLEM TO BE SOLVED: To simply and accurately determine the amount of collection in a particulate filter. SOLUTION: This particulate filter(DPF) 43 and a specific component concentration sensor 59 for detecting a specific component such as HC and NOx in exhaust are interposed in an exhaust passage 3 for an engine 1, and and EGR valve 23 for controlling the quantity of EGR gas is interposed in an EGR passage 33 for the engine. An electronic control unit(ECU) 30 for the engine provides feedback control on the opening of the EGR valve so that the intake air quantity that an airflow meter 25 detects becomes a target intake air quantity set according to the engine operating state. The ECU determines the amount of collection in the DPF by comparing the specific component concentration in exhaust that the sensor 59 detects during the EGR valve opening feedback control with a specific component concentration (reference concentration) obtained in a reference state wherein the amount of particulates collected in the DPF is a known value. |
