JPS6469765A - Rotary throttle valve type carburetor - Google Patents

Abstract

PURPOSE:To facilitate the adjustment of fuel in an intermediate speed region by forming a passage extended into a suction hole formed on a fuel nozzle and a fuel passage formed on a carburetor body at the boss part of a throttle valve in the passage in the radial direction which communicates with an intermediate opening degree of the throttle valve. CONSTITUTION:When a valve shaft 40 is turned by a throttle lever 2, a rotary throttle valve 14 is integrally turned through a pin 38, and the direction of a suction hole 35 for an intake inlet 13 is changed, and the intake quantity is controlled. Further, the valve shaft 40 is shifted leftward against a spring 7 by the action of a ball 41 engaged with a cam surface 42. When a fuel metering needle valve 10 shifts leftward integrally with the valve shaft 40, the opening area of the injection port 36 of a fuel nozzle 12 increases, and the fuel quantity is increased. In this case, when the opening degree of the rotary throttle valve 14 becomes an intermediate value, the passages 71 and 72 are allowed to communicate each other. Then, fuel is allowed to pass through an intermediate speed fuel adjusting member 76, passages 70-72, annular chamber 73, and a passage 74, and attracted into an air intake hole 35.