Patent ID: 8087236

Claim:
An exhaust gas purifying apparatus for an internal combustion engine including a first exhaust passage and a second exhaust passage into which a common exhaust passage provided upstream of the first and second passages is bifurcated, wherein a NOx absorbent is provided in each of the first exhaust passage and the second exhaust passage, the NOx absorbent storing NOx contained in exhaust gas when an air-fuel ratio of incoming exhaust gas becomes lean and releasing the NOx when the air-fuel ratio of incoming exhaust gas becomes rich, wherein: a fuel valve is provided in the common exhaust passage; when it is necessary to release NOx from the NOx absorbent provided in the first exhaust passage and from the NOx absorbent provided in the second exhaust passage, fuel is supplied from the fuel valve so as to make the air-fuel ratio of exhaust gas in both of the first exhaust passage and the second exhaust passage rich; and one of the first exhaust passage and the second exhaust passage is closed during a period during which the air-fuel ratio of exhaust gas in the one of the first exhaust passage and the second exhaust passage remains rich, after the fuel is supplied from the fuel valve.