| 摘要 |
PURPOSE:To purify exhaust gas by using a low-priced carburetor without using an expensive oxygen-concentration detector and an expensive electronic control unit for controlling air-fuel ratio. CONSTITUTION:A variable venturi type carburetor 2 is installed onto an intake manifold 1, and a catalyst converter 4 is installed on the downstream side of an exhaust manifold 3. A valve port 36 whose opening area is controlled by a linear solenoid valve 40 is installed in an air bleed passage 34. In the ordinary operation where the temperature of a carburetor housing 6 is low, a temperature sensing switch 56 is turned OFF, and the opening area of the valve port 36 is varied in proportion to the electric current which flows in a solenoid 43. When the temperature of the carburetor housing 6 rises, the mixed gas is condensed excessively, so the temperature sensing switch 56 is turned ON so that the opening area of the valve body 41 of the linear solenoid valve 40 is increased, and the valve body 41 of the linear solenoid valve 40 is kept at a constant opening degree. |
