EXHAUST GAS PURIFYING APPARATUS FOR INTERNAL COMBUSTION ENGINE

摘要

An exhaust gas purifying apparatus for an internal combustion engine (1) is provided. The apparatus includes a recoverable type exhaust gas purifying device (10) provided in an exhaust passage (4), a reducing agent addition device (8) upstream of the exhaust gas purifying device, an operation control device (20) for controlling operation of the reducing agent addition device, a pressure obtaining device (23) downstream from the reducing agent addition device and upstream from the exhaust gas purifying device; and a diagnosing device for diagnosing the reducing agent addition device based on the pressure obtained by the pressure obtaining device at an estimate arrival-time when the reducing agent added from the reducing agent addition device is estimated to arrive at the exhaust gas purifying device in a case the operation of the reducing agent addition device is controlled by the operation control device such that the reducing agent is added into the exhaust passage.