| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of positively decomposing urea water into ammonia to obtain an excellent NOx reducing effect from an exhaust temperature lower than the conventional one even in a vehicle of such an operating form that an operating state at a low exhaust temperature continues for a long time. <P>SOLUTION: An injection port 14 of urea water 13 is arranged toward the lower reaches inside a chamber 12 upstream of a selective reduction type catalyst 10, and a heater 15 serving as a heating device 16 is disposed downstream thereof. An exhaust temperature detector 22 detecting the temperature of exhaust gas 7, and a heating device temperature detector 23 detecting the temperature of the heater 15 are provided, and a control device 24 outputs a control signal 16a for applying a current to the heater 15 to generate heat so that the actual heating device temperature based on a detection signal 23a from the heating device temperature detector 23 is an appropriate temperature under the condition that the actual exhaust temperature based on a detection signal 22a from the exhaust temperature detector 22 is about 200°C or less. <P>COPYRIGHT: (C)2007,JPO&INPIT |
