Patent ID: 8413425
Filing Date: 2013-04-09
Classification: B01D,F01N,Y02T

Abstract:
1. A control method for an internal combustion engine exhaust gas purification apparatus for injecting a reducing agent into an exhaust gas passage of an internal combustion engine at an upstream side of a reduction catalyst, disposed in the exhaust gas passage, for selectively reducing NOx in an exhaust gas emitted from the internal combustion engine, the control method comprising the steps of: predicting a transition of a temperature of the reduction catalyst and determining whether or not the temperature of the reduction catalyst continues to decrease for a predetermined time or longer; injecting the reducing agent according to a first target adsorption amount which is read based on a first target adsorption amount curve indicating a relationship between the temperature of the reduction catalyst and the first target adsorption amount that is a smaller value than a saturated adsorption amount of the reducing agent corresponding to the temperature of the reduction catalyst if it is determined that the temperature of the reduction catalyst does not continue to decrease for a predetermined time or longer; and injecting the reducing agent according to a second target adsorption amount which is read based on a second target adsorption amount curve indicating a relationship between the temperature of the reduction catalyst and the second target adsorption amount that is a value larger than the first target adsorption amount and smaller than a saturated adsorption amount if it is determined that the temperature of the reduction catalyst continues to decrease for a predetermined time or longer.