| 摘要 |
<P>PROBLEM TO BE SOLVED: To satisfy a request of cost reduction while securing the exhaust gas purification rate in a range extender type electric vehicle equipped with the engine for power generation. <P>SOLUTION: The engine 10 for the power generation does not need so much responsiveness of the air-fuel ratio control in transient operation since normal driving can be carried out except when switching the operation modes responding to the request power generation amount etc. Taking this point into account, an exhaust gas sensor 39(e.g. oxygen sensor) is installed on the downstream side of catalyst 38, and the air-fuel ratio feedback control is executed based on the output of this exhaust gas sensor 39. Thereby, the decrease in the air-fuel ratio control accuracy can be suppressed by reducing the change (variation) in the output characteristic of the exhaust gas sensor 39 compared with the case when installing the exhaust gas sensor on the upstream side of the catalyst, and the exhaust gas purification rate of catalyst 38 can be secured. Moreover, the cost reduction can be achieved compared with the case when installing the exhaust gas sensor on both the upstream side and the downstream side of the catalyst. <P>COPYRIGHT: (C)2012,JPO&INPIT |
