Engine exhaust gas cleaning apparatus

摘要

An engine exhaust gas cleaning apparatus is provided to minimize torque shook as during regeneration of an exhaust gas cleaning device (11, 12 or 13). The engine exhaust gas cleaning apparatus comprises a fuel delivery device (3) for delivering fuel to an engine (1) at a lean excess air ratio » during normal operation of the engine; a NOx trapping catalytic converter (12) for adsorbing NOx from the exhaust gas during the lean operation; a regeneration control section for adjusting the excess air ratio X to a rich target value to regenerate the NOx trapping catalytic converter (12); a feedback control section that feedback-controls the fuel delivery quantity to hold the excess air ratio » at the target value during regeneration; a feedback control restricting section that restricts the feedback control during regeneration until the difference between the target value and the actual excess air ratio » is less than a prescribed value.