EXHAUST GAS PURIFICATION APPARATUS FOR AN INTERNAL COMBUSTION ENGINE

摘要

An object of the present invention is to improve preferable promotion of the modification of reducing agent in a precatalyst in the case where the reducing agent is added through a reducing agent addition valve in order to supply the reducing agent to an exhaust gas purification catalyst. According to the present invention, one end of an exhaust passage in which an exhaust gas purification catalyst is provided is connected to an exhaust manifold, and a precatalyst and a reducing agent addition valve are provided in the exhaust manifold. The precatalyst is configured in such a way that the exhaust gas flows through the gap between the outer circumferential surface thereof and the inner wall surface of the exhaust manifold. The precatalyst and the reducing agent addition valve are arranged in such a way that the most part of the reducing agent added through the reducing agent addition valve flows into the precatalyst.