Patent ID: 7231761

Claim:
An exhaust gas purification system of an internal combustion engine, the exhaust gas purification system comprising: a particulate filter disposed in an exhaust pipe of the engine; temperature increasing means for increasing temperature of the particulate filter; operating state sensing means for sensing an operating state of the engine; temperature sensing means for sensing the temperature of the particulate filter; deposition quantity estimating means for estimating a deposition quantity of particulate matters deposited on the particulate filter; and regeneration controlling means for operating the temperature increasing means to increase the temperature of the particulate filter to proximity of a predetermined target temperature when an output of the deposition quantity estimating means exceeds a predetermined value, whereby the particulate matters deposited on the particulate filter are combusted and eliminated, wherein the regeneration controlling means includes: basic operation amount calculating means for calculating a basic operation amount of the temperature increasing means; feedback gain calculating means for calculating a feedback gain corresponding to each degree of a delay in a change of exhaust gas temperature with respect to a change of the operation amount of the temperature increasing means based on an output of the operating state sensing means; and correction value calculating means for calculating a correction value of the operation amount of the temperature increasing means by multiplying a deviation between the output of the temperature sensing means and the target temperature by the feedback gain.