| 摘要 |
An object of this invention is to accurately estimate an amount of sulfur deposition on a NOx catalyst while avoiding the emission of sulfur and a deterioration in the fuel consumption efficiency. A main catalyst 30 constituted by a NOx catalyst or an S trap catalyst is provided in an exhaust passage 22 of an internal combustion engine 10. A sub-catalyst 32 having a SOx storage agent is provided at a position on the upstream side of the main catalyst 30 in the exhaust passage 22. An ECU 50 detects a temperature increase amount of the sub-catalyst 32 during execution of S-regeneration control, and estimates an amount of sulfur deposition on the main catalyst 30 based on the temperature increase amount. Thus, the amount of sulfur deposition can be estimated using the sub-catalyst 32 before performing S-regeneration control for the main catalyst 30, and control for avoiding the emission of sulfur and a deterioration in the fuel consumption efficiency can be executed based on the estimation result. |
