| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an failure detection device and an failure detection method which accurately detect the clogging of a reducing agent injection valve, and to provide an internal combustion engine exhaust emission control device. <P>SOLUTION: A reducing agent injection device includes a storage tank that houses a reducing agent, a pump that pressure-feeds the reducing agent, a reducing agent injection valve that injects the reducing agent pressure-fed by the pump into the exhaust pipe of an internal combustion engine, a supply path that interconnects the pump and the reducing agent injection valve, and a pressure sensor disposed in the supply path. The reducing agent injection device is configured such that it can suck, into the inside of the supply path, a gas inside the exhaust pipe via an injection hole in the reducing agent injection valve by subjecting the inside of the supply path to depressurization processing. A failaure detection device and the like detect the clogging of the reducing agent injection valve in the reducing agent injection device and include a clogging determination component. The clogging determination component uses a pressure value detected by the pressure sensor after the start of the depressurization processing to determine whether or not clogging is caused in the reducing agent injection valve. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
