EXHAUST PURIFICATION DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an exhaust purification device of an internal combustion engine that includes a constitution improving purification performance by electric discharge in purifying NOx, and in which input electric power and electric discharge period length are properly controlled.SOLUTION: Electrodes 62, 63 are arranged in a NOx occlusion agent carrier 5 included in an exhaust pipe 3 of an engine 2, and executes electric discharge in reducing NOx. In electric discharge, a NOx decomposition amount in the rear end of the carrier 5 is estimated from the light emission intensity (a numerical value reflecting the amount of re-connected NO) of a wavelength of 247 nm received by light reception lenses 71, 72. When the NOx decomposition amount in the rear end of the carrier 5 is larger than a threshold (for example, 0), input electric power increases, and when it is smaller than the threshold, input electric power decreases.