| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To detect minimal leak of reducing agent or addition amount slippage of reducing agent. <P>SOLUTION: A reducing agent supply system 4 includes an addition valve 5 for adding a reducing agent to an exhaust passage 2 of an internal combustion engine 1; a tank 6 having a main tank 7 and a sub-tank 8; a feed pump 11 for supplying reducing agent from the sub-tank 8 to the addition valve 5; a suction pump 13 for sucking reducing agent to be recovered into the tank 6; and an on-off valve 14 for opening and closing a communication part between the main tank 7 and the sub-tank 8; a residual quantity detection means 15 which detects a reducing agent residual quantity in the sub-tank 8; and a control means 100. The control means 100 closes the on-off valve 14 in execution of failure diagnosis. Since only the residual quantity in the sub-tank 8 with small capacity is detected by the high-accuracy residual quantity detection means 15, the minimal leak of reducing agent and addition amount slippage of reducing agent can be detected. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
