EXHAUST GAS PURIFICATION DEVICE

摘要

An ECU performs correction so that the interval of fuel addition is reduced as the amount of variation in exhaust gas temperature increases, the correction being based on the amount of variation in current exhaust gas temperature relative to a basic exhaust gas temperature when a basic addition interval is set (Steps ST1-ST4). If exhaust gas temperature rises at high altitude, such correction as above of the interval of fuel addition reduces and corrects the interval of fuel addition according to the rise in the exhaust gas temperature, increasing and correcting the amount of fuel addition. As a result, rise in temperature of the tip of the fuel addition valve is suppressed, so that clogging of the ejection hole by deposit can be prevented.