Patent ID: 7310941
Filing Date: 2007-12-25
Classification: F01N,F02D,Y02T

Abstract:
1. An exhaust gas purification system of an internal combustion engine having a particulate filter located in an exhaust passage of the engine for collecting exhaust particulate matters, the exhaust gas purification system regenerating the particulate filter by eliminating the exhaust particulate matters collected by the particulate filter, the exhaust gas purification system comprising: a flowing state sensing device that senses a flowing state of exhaust gas at the particulate filter; a first accumulation quantity estimation device that estimates an accumulation quantity of the exhaust particulate matters in the particulate filter based on the flowing state of the exhaust gas; an operating state sensing device that senses an operating state of the engine; a second accumulation quantity estimation device that estimates the accumulation quantity of the exhaust particulate matters in the particulate filter based on the operating state of the engine; an employment condition determination device that determines whether employment conditions to employ the first accumulation quantity estimation device including a condition that a flow rate of the exhaust gas flowing through the exhaust passage is equal to or greater than a predetermined flow rate are satisfied; and a regeneration start accumulation quantity calculation device including an estimation error calculation device that calculates an estimation error representing a correction value of the first or second accumulation quantity estimation device with respect to a limit accumulation quantity of the exhaust particulate matters in the particulate filter, wherein the regeneration start accumulation quantity calculation device calculates a regeneration start accumulation quantity for starting the regeneration of the particulate filter by subtracting the estimation error of the first or second accumulation quantity estimation device from the limit accumulation quantity.