Abgasreinigungsvorrichtung einer Brennkraftmaschine

摘要

An exhaust gas purifying device of the invention comprises an exhaust gas purifying catalyst (20) disposed in an exhaust system, a fuel adding device (28) for adding fuel to the exhaust gas purifying catalyst (20) as a reducing agent, a fuel supplying source (6) for supplying the fuel adding device (28) with fuel, an emergency shut-off valve (31) disposed in a fuel supplying passage (29) that connects the fuel supplying source (6) to the fuel adding device (28), and a shut-off valve position detecting means for detecting that the emergency shut-off valve (31) is closed. If an upstream fuel pressure applied to the emergency shut-off valve (31) becomes higher than a downstream fuel pressure applied to the emergency shut-off valve (31), the emergency shut-off valve (31) is controlled so as to be prevented from being opened. If the exhaust air-fuel ratio does not shift to the rich side despite the issuance of an instruction to add fuel at this moment, it is possible to detect that fuel leakage has occurred downstream of the emergency shut-off valve (31).