EXHAUST SYSTEM FOR INTERNAL COMBUSTION ENGINE

摘要

An object of the present invention is to provide a technology that enables efficient utilization of the purification capability of an exhaust gas purification apparatus. To achieve the object, according to the present invention, in an exhaust system of an internal combustion engine provided with a reducing agent supply apparatus 6 that supplies a reducing agent to the exhaust gas before it flows into an exhaust gas purification apparatus 5, an extension chamber 3 is provided downstream of the position at which the reducing agent supply apparatus 6 supplies the reducing agent to the exhaust gas and upstream of the exhaust gas purification apparatus 5. The extension chamber 3 is provided with a back step flow creating portion 33 that creates a back step flow of the exhaust gas in the extension chamber 3 and a swirling flow creating portion 31 that creates a swirling flow. As the exhaust gas and the reducing agent flow into the extension chamber 3 as described above, the mixing of the exhaust gas and the reducing agent is promoted by a combined effect of the back step flow and the swirling flow, and partial localization of the distribution of the flow rate is eliminated.