EXHAUST PURIFICATION APPARATUS FOR INTERNAL COMBUSTION ENGINE

摘要

Provided is an exhaust purification apparatus for an internal combustion engine with a DPF disposed in the exhaust system of the internal combustion engine, such that accumulation of ash in the DPF can be suppressed, and increases in pressure loss and PM regeneration temperature as well as a decrease in fuel efficiency can be suppressed over a long period. A surface of the DPF is coated with a solid acid with an acid strength greater than the acid strength of SO3 and smaller than the acid strength of SO4. Ash regeneration operation control for removing the ash accumulated in the DPF by making particles of ash finer through control for increasing the temperature of the DPF and air-fuel ratio control for the atmosphere within the DPF is performed on the basis of the amount of accumulated ash acquired by an ash accumulation amount acquisition means.