| 摘要 |
PURPOSE:To enable control of air/fuel ratio easily and at a high accuracy, by providing a diffusion hole at one of two partitions so as to communicate with a diffusion cavity formed between the two partitions. CONSTITUTION:A diffusion hole 14 is provided at one of partitions 12 and 13 to take in an exhaust gas into a diffusion cavity 11. Then, a driver 21 is connected to a variable resistor 18 and the operation of the unit 21 is controlled by a controller 22 on a detection signal from a voltmeter 15. The unit 22 control the turning ON/OFF of the operation of the unit 21 and the power source 17 on the basis of a map of a air/fuel. On the other hand, when the operating condition of a vehicle is in a theoretical air/fuel ratio area, the power source 17 is held nonenergized and a difference between the partial oxygen pressure in an exhaust gas and the partial oxygen pressure in the outside air is read out from the voltmeter 15. Then, it is judged whether the air/fuel ratio corre sponding to the electromotive force meet the target theoretical air/fuel ratio or not. When it does not, the air/fuel ratio is controlled to match the theoretical air/fuel ratio. Here, the use of an O2 sensor as measuring means enables a highly accurate control. |
