EXHAUST PURIFICATION SYSTEM OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an exhaust purification system of an internal combustion engine which effectively prevents abnormal combustion in a DPF.SOLUTION: An exhaust purification system of an internal combustion engine includes a DOC 21 provided in an exhaust system of an engine 10; a DPF22 which is provided in a downstream side of the DOC 21 and collects PM in exhaust gas; an electrode 27 which detects the electrostatic capacitance of the DPF 22; a DPF internal temperature calculation unit which calculates an internal temperature of the DPF 22 on the basis of the electrostatic capacitance input from the electrode 27; a forcible regeneration control unit which, when a PM accumulation amount in the DPF 22 reaches to a prescribed amount, carries out forcible regeneration in which fuel is injected into the DOC 21 to combust and remove particulate matters; and an abnormal combustion prevention control unit which suppresses the combustion of PM within the DPF 22 when the DPF internal temperature input in the forcible regeneration from the DPF internal temperature calculation unit exceeds a prescribed upper threshold.