METHOD FOR DETECTING PRESSURE DIFFERENCE ACROSS DPF AND DEVICE FOR DETECTING PRESSURE DIFFERENCE ACROSS DPF

摘要

A method for detecting the pressure difference across a DPF and a device for detecting the pressure difference across the DPF accurately determine the timing of the regeneration on the basis of the amount of accumulation of PM.When the vehicle is in a state in which there is no fuel supply to the internal combustion engine (10), the exhaust pipe (2) is closed at a position upstream of a DPF (3), the exhaust gas is bypassed to a position downstream of the DPF (3) from a position upstream of the position at which the exhaust pipe (2) is closed, air is caused to flow from a positive pressure pump (6) to a position between the DPF (3) and the position at which the exhaust pipe (2) is closed, and the pressure difference across the DPF (3) is detected.