| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect a decline in efficiency in order to prevent a decline in efficiency caused by degradation of a catalyst of an internal combustion engine in its long-term operation, and control an engine so that high efficiency can be maintained. <P>SOLUTION: A catalyst 3 is arranged at an exhaust pipe 2 of an engine 1 of the device. Sensors 7, 8 for detecting exhaust condition are arranged at the front and the rear of the catalyst 3. The sensors 7, 8 can be, for example, oxygen sensors of which output changes in step at λ= 1, or a sensor of which output changes in proportion to an air-fuel ratio. The values detected by both of the sensors are taken into a control unit 9. Then purification efficiency and a degree of degradation of the catalyst are estimated by the compared results, and the engine is controlled so that efficiency can be optimized. Thus, since a decline in efficiency of the catalyst caused by its long-term operation is accurately detected, and the engine is controlled so that the decline in efficiency can be avoided, high exhaust-purifying properties can be maintained. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
