| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To accurately detect a volume of particulate deposition by calibrating both of a zero point and sensitivity of a sensor for detecting a differential pressure in an exhaust-emission control device provided with DPF, and attain a safe and positive regeneration. <P>SOLUTION: In the exhaust-emission control device, a muffler 3 is placed downstream of the DPF 2 placed in an exhaust pipe 5 of the internal combustion engine. A differential pressure between the fore and aft parts of the DPF 2 or the muffler 3 is detected by using the muffler 3 as a device for pressure calibration, and selecting a pressure-introduction path by a three-way valve 4. An ECU 8 conducts a zero calibration on the basis of an output of the differential sensor 1 at the time of exhaust flow-rate being zero. At the same time, the ECU 8 conducts calibration of sensitivity of the sensor on the basis of the differential pressure between the fore and aft of the muffler 3 under a predetermined operation condition. The differential pressure between the fore and aft parts of the DPF 2 is calibrated on the basis of the calculated sensitivity of the sensor, and conditions of particulate-trap is accurately detected. <P>COPYRIGHT: (C)2004,JPO</p> |
