EXHAUST CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To control an EGR amount not to exceed the upper limit during catalyst regeneration control and in a transitional state of an internal combustion engine when including an exhaust gas recirculation device for recirculating exhaust gas from the downstream part from a fuel adding valve provided to an exhaust passage. SOLUTION: An exhaust emission control device such as DPF and NOx storage/reduction catalysts is provided on an exhaust passage. A fuel adding valve is provided on the upstream side of the exhaust emission control device. The exhaust control device includes a high pressure loop EGR device for circulating exhaust gas from the upstream side of the exhaust emission control device to the intake side and a low pressure loop EGR device for circulating exhaust gas from the downstream side of the exhaust emission control device to the intake side. When an engine is brought into a transitional state due to acceleration request or the like in the course of regeneration control of the exhaust emission control device by fuel addition, changes in intake air amount, engine rotation speed or the like accompanying it lead to the increase in a CO2wraparound amount. When the engine is brought into a transitional state during regeneration control and an exhaust recirculation amount is determined to exceed the maximum value, the exhaust recirculation amount of the high pressure loop exhaust recirculation device quick in response is adjusted. COPYRIGHT: (C)2008,JPO&INPIT