Patent ID: 7281368

Claim:
An NO x discharge quantity estimation method for an internal combustion engine equipped with an EGR apparatus for circulating to an intake passage of the engine a portion of exhaust gas flowing through an exhaust passage of the engine, characterized by comprising the steps of: estimating a combustion region, the combustion region being a region of the combustion chamber in which combustion occurs; estimating, as a combustion-generated NO x quantity, a quantity of NO x generated within the combustion region as a result of combustion, and an NO x quantity in a non-combustion region, the non-combustion region being the remaining region of the combustion chamber; and estimating, on the basis of the combustion-generated NO x quantity and the NO x quantity in the non-combustion region, a quantity of NO x contained in exhaust gas discharged from the exhaust passage to the outside.