| 摘要 |
PURPOSE:To smooth the return of air-fuel ratio to fuel cut by providing a path for connecting a suction chamber in a carbureter to the downstresm portion of a throttle valve in an intake pipe and interposing a valve unit opened during deceleration in said path. CONSTITUTION:In a carbureter, Venturi negative pressure produced in a Venturi portion 5 according to the opening of a throttle valve 6 is introduced into a suction chamber 11 through a hole 12 so that a suction piston 4 slides according to the size of the negative pressure and an annular gap between a needle 17 and a nozzle 7 is adjusted to control the discharge of fuel. In this case, the suction chamber 11 is connected through pipes 26, 27 to the downstream portion of the throttle valve 6 in an intake pipe 9, and a tow-step solenoid valve 28 is interposed between pipes 26, 27. This solenoid 28 is controlled to open first valve body and first and second valve bodies in deceleration from low speed and high one and reduce the Venturi negative pressure according to the running condition. |
