Exhaust particle removing system for an internal combustion engine

摘要

A filter disposed in an engine exhaust passage traps particles suspended in exhaust gas. A burner serves to burn off the particles deposited on the filter. The pressures in the exhaust passage at points upstream and downstream of the filter are sensed. A determination is made as to whether or not the sensed upstream pressure is lower than a preset level. When the sensed upstream pressure is not lower than the preset level, the degree of clogging of the filter is deduced on the basis of the sensed upstream and downstream pressures. When the sensed upstream pressure is lower than the preset level, the degree of clogging of the filter is deduced on the basis of a time elapsed since the moment at which the sensed upstream pressure dropped below the preset level and on the basis of the sensed upstream and downstream pressures obtained immediately prior to that moment.