| 摘要 |
PURPOSE:To improve durability, and to economize electric power consumption, by mounting a by-catalyst convertor buidling in an electric heater to a by-path, and by actuating the convertor only for a time of starting. CONSTITUTION:When an ignition switch 11 is in ON and an engine is started, a by-path opening and closing valve 5 is opened by means of a control unit 10 while an electric heater 7 is energized, thus starting heating. One portion or the whole of exhaust from the engine are passed through a by-path 4 by the action of a bimetal working type throttle valve 12. In this case, exhaust is burnt by a by-catalyst convertor 6, and exhaust after treated by the convertor is discharged through a main catalyst convertor 3. Thus, when the warming-up of the by-catalyst convertor 6 is completed and detected by means of a temp sensor 9 said heater 7 is de-energized, and when the warming-up of the convertor 3 is finished the opening and closing valve 5 is closed. |
