Patent ID: 8201397
Filing Date: 2012-06-19
Classification: F01N,Y02T

Abstract:
1. An exhaust gas purification device of an internal combustion engine applied to an exhaust gas purification system that has a NOx catalyst provided in an exhaust passage of the internal combustion engine for adsorbing a reducing agent and for selectively purifying NOx in exhaust gas with the reducing agent and that adds the reducing agent with a reducing agent adding unit upstream of the NOx catalyst with respect to a flow direction of the exhaust gas, the exhaust gas purification device comprising: an adsorption quantity calculating unit configured to calculate a reducing agent adsorption quantity in the NOx catalyst based on time-series data of a balance between supply of the reducing agent to the NOx catalyst accompanying the addition of the reducing agent by the reducing agent adding unit and consumption of the reducing agent due to a reduction reaction in the NOx catalyst; a NOx quantity calculating unit configured to calculate a NOx quantity introduced into the NOx catalyst or a parameter correlated with the NOx quantity; and an initialization performing unit configured to perform initialization of the reducing agent adsorption quantity at timing decided based on a calculation result of the NOx quantity calculating unit; wherein the NOx quantity calculating unit calculates a NOx quantity integration value by sequentially integrating the NOx quantity introduced into the NOx catalyst, and the initialization performing unit performs the initialization at timing when the NOx quantity integration value reaches a predetermined value.