EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To prevent excessive supply of a reducing agent to an NOX catalyst in the case where the memory content of a memory means is lost. SOLUTION: With an NOX catalyst 14 capable of reducing an NOX in an oxidized air containing a reducing agent provided in an engine exhaust path, a reducing agent is supplied from a reducing agent supplying device 17 to the NOX catalyst 14 for reducing the NOX The reducing agent adsorption amount of the NOX catalyst 14 is stored in a B-RAM 35 so that the reducing agent supply amount is calculated based on the reducing agent adsorption amount stored in the B-RAM 35. In the case the memory content of the B-RAM 35 is lost, the reducing agent is supplied to the NOX catalyst 14 by the amount calculated with the assumption that the reducing agent adsorption amount stored in the B-RAM 35 is the saturated adsorption amount of the NOX catalyst 14.