| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reducing agent injection device capable of eliminating plugging of a reducing agent injection valve caused by the solidification of a urea water solution, thereby controlling the deterioration of exhaust emission control efficiency. <P>SOLUTION: The reducing agent injection device that supplies the urea water solution inside an exhaust pipe through the reducing agent injection valve fixed to the exhaust pipe, and collects the urea water solution inside the reducing agent injection valve into a storage tank when an internal combustion engine is suspended, includes a force feed pump that sends the urea water solution by pressure and a reducing agent supply passage connecting the force feed pump and reducing agent injection valve, determines that the plugging is being formed at the reducing injection valve caused by the solidification of the urea water solution, and generates pressure pulsation inside the reducing agent supply passage for a predetermined period of time (W1). <P>COPYRIGHT: (C)2012,JPO&INPIT |
