| 摘要 |
PURPOSE:To enable to obtain a proper fuel-air ratio for both of gasoline and alcohol in an internal combustion engine of the type in which fuel is switched to alcohol when the engine is warmed up, by employing such an arrangement that the back pressure of exhaust gas is applied to a carburetor chamber by operating a changeover valve simultaneously with the switching of fuel from gasoline to alcohol. CONSTITUTION:When the engine temperature is low, a fuel switching valve 4 is connected to a gasoline tank 2, so that gasoline is supplied to a carburetor chamber 5. In this state, a changeover valve 10 is opened to the atmosphere, so that the atmospheric pressure is introduced into the chamber 5 for obtaining a proper air-fuel ratio for gasoline. Although the engine is started by use of gasoline, a temperature sensor 6 is operated as the engine is warmed up, and the fuel switching valve 4 is switched to communicate to an alcohol tank 3 by means of a solenoid 7, so that alcohol is supplied to the chamber 5. At the same time, the changeover valve 10 is switched by a solenoid 11 to communicate to an exhaust pipe 8, so that the back pressure of exhaust gas is applied to the chamber 5. Thus, since alcohol is supplied under pressure to the carburetor, it is enabled to obtain a proper air-fuel ratio suited for alcohol. |
