| 摘要 |
PURPOSE:To control the amount of mixed air and the air-fuel ratio and to lower the exhaust gas temperature by providing a valve disk upstream the venturi section of a carburetor and by outputting a signal for reducing the aperture of the valve disc from a valve aperture control unit when the detected temperature of an exhaust gas temperature sensor reaches a predetermined temperature or above. CONSTITUTION:When the temperature of an exhaust gas purifier reaches a certain value and above, a valve aperture control unit 11 compares for decision the detected temperature signal fed from a temperature sensor 8 with a reference signal, and processes by calculation the signal fed from a throttle sensor 9, then feeds an electromagnetic solneoid 12 a signal with a voltage level that will make the aperture of a choke valve 4 less than that of a throttle valve 5. The solneoid 12 absorbs a plunger 22 toward the X1 direction with a suction force corresponding to the signal so that a lever 21 is rotated toward the X2 direction and a choke lever 15 is rotated, thus closing the choke valve 4 up to the position that the spring force of a coil spring 14 is balanced with the suction force of the solenoid 12. Therefore, the aperture of the choke valve 4 is made smaller than that of the throttle valve 5. |
