Patent ID: 8087234

Claim:
An exhaust gas purification controller for controlling bed temperature of an exhaust gas purification catalyst arranged in an exhaust system of an internal combustion engine at a target bed temperature by supplying fuel to the internal combustion engine, the exhaust gas purification controller comprising: a control unit which is programmed to learn a supply amount of fuel that allows for a correction of a difference between the catalyst bed temperature and the target bed temperature in the present state and is programmed to reflect a learned value obtained through the learning on the supply amount of when controlling the bed temperature of the exhaust gas purification catalyst: a transitional state detection unit which is programmed to detect a transitional state of an exhaust gas flow to the exhaust gas purification catalyst, wherein the control unit is programmed to restrict the learning when the transitional state of the exhaust gas flow is detected; and wherein based on a temperature and flow amount of exhaust gas to the exhaust gas purification catalyst, the transitional state detection unit is programmed to obtain an average exhaust gas energy, which is an average value of exhaust gas energy, momentary exhaust gas energy, which is a momentary value of exhaust gas energy, and a cumulative value of a deviation of the average exhaust gas energy and the momentary exhaust gas energy; and the transitional state detection unit is programmed to detect a transitional state of the exhaust gas flow when the cumulative value of the deviation becomes greater than or equal to a predetermined determination value.