EXHAUST GAS PURIFICATION DEVICE FOR ENGINE

摘要

An exhaust gas purification device for an engine, comprising a reducing catalyst for reducing nitrogen oxide by reducing agent, a reducing agent supply device for supplying the reducing agent at a flow rate depending on operating conditions of the engine, a residual quantity detection device for detecting the residual quantity of the reducing agent, an alarm for issuing a human-perceptible alarm, and a control unit receiving the residual quantity of the reducing agent detected by the residual quantity detector and controlling operation of the alarm. A control program stored in the control unit is executed to calculate a consumption rate of the reduction agent, the consumption rate being indicative of a distance that is travelable by a unit volume of the reducing agent while reductive purification effect for nitride oxide by the reducing agent is exhibited, and at the same time to estimate and calculate a distance travelable by the residual quantity of the reducing agent based on the residual quantity and the consumption rate. The alarm is activated when the travelable distance is equal to a predetermined value or less.