| 摘要 |
PURPOSE:To increase a negative pressure in a mixing chamber and to improve response of fuel feed to ON-OFF of an electromagnetic valve for fuel cut, by a method wherein a slow air passage, which joins a slow fuel passage in the mixing chamber, is closed simultaneously when fuel is cut. CONSTITUTION:A mixing chamber 26 is formed in a carburetter body 21 in the shape of an approximately cylinder extending along a horizontal direction, and the upper end of a slow air-fuel mixture passage 27, communicated with an idle port 31 and a bypass port 32, is connected to the under surface of the mixing chamber 26. A slow fuel passage 24 is connected to the one end of the mixing chamber 26, and a slow air passage 29 on the downstream of a slow air bleed 28 is connected to the other end thereof through a communicating hole 30, and first and second valve seat parts 33 and 34, which are simultaneously opened by a staged plunger 36 of an electromagnetic valve 35, are mounted to both ends of the mixing chamber 26. If the electromagnetic valve 35 is brought into an OFF-state when the supply of fuel is disconnected, the valve seat parts 33 and 34 are respectively closed by the plunger 36 to increase a negative pressure introduced in the mixing chamber 26 and the slow air-fuel mixture passage 27. |
