Patent ID: 8707680
Filing Date: 2014-04-29
Classification: B01D,F01N,Y02T

Abstract:
1. An exhaust purification system of an internal combustion engine in which an air-fuel ratio sensor for detecting an air-fuel ratio of exhaust gas is arranged in an engine exhaust passage and an exhaust purification control is performed based on an air-fuel ratio detected by the air-fuel ratio sensor, wherein the air-fuel ratio sensor is comprised of a type of sensor which has a solid electrolyte, electrodes respectively covering two side surfaces of the solid electrolyte, and a diffusion resistance layer covering one of electrodes and in which exhaust gas is guided on to the diffusion resistance layer, when the air-fuel ratio of the exhaust gas changes and the air-fuel ratio detected by the air-fuel ratio sensor changes, the change of the air-fuel ratio detected by the air-fuel ratio sensor is governed by an amount of deposition of sulfur ingredients at the air-fuel ratio sensor, at this time, the larger the amount of deposition of sulfur ingredients at the air-fuel ratio sensor becomes, the smaller an amount of change of the air-fuel ratio detected by the air-fuel ratio sensor and the longer a time period of change of the air-fuel ratio become, and an amount of sulfur poisoning of the air-fuel ratio sensor is detected from the change of the air-fuel ratio detected by the air-fuel ratio sensor at this time.