Patent ID: 7254940
Filing Date: 2007-08-14
Classification: F01N,Y02T

Abstract:
1. An exhaust gas purification system of an internal combustion engine including a particulate filter in an exhaust passage of the engine for collecting exhaust particulate matters contained in exhaust gas, the exhaust gas purification system being provided so that regeneration of the particulate filter for combusting and reducing the exhaust particulate matters deposited on the particulate filter is performed by spontaneous regeneration, in which the deposited exhaust particulate matters are spontaneously combusted and reduced in the particulate filter by an increase of a temperature of the exhaust gas without control for increasing the exhaust gas temperature, and is performed by compulsory regeneration for compulsorily combusting and reducing the deposited exhaust particulate matters when a present deposition quantity of the deposited exhaust particulate matters, which is calculated based on operating states of the engine, exceeds a predetermined upper limit value, the exhaust gas purification system comprising: determining circuitry for determining whether the spontaneous regeneration occurs or not based on the operating states of the engine; controlling circuitry for completely performing the compulsory regeneration to eliminate the deposited exhaust particulate matters if the determining circuitry determines that the spontaneous regeneration stops after a start of the spontaneous regeneration and if the deposition quantity becomes equal to or less than a predetermined reset value; and temperature measuring circuitry for measuring the temperature in the particulate filter, wherein the determining circuitry determines that the spontaneous regeneration occurs if the sensed temperature exceeds a predetermined reference temperature.