| 摘要 |
PURPOSE:To vary a fuel injection quantity according to a bleed air quantity as well as to control an air-fuel ratio so simply and highly accurately, by turning an air valve, attached to the inside of an air passage, in an opening direction against a spring according to rotation of a cam formed in a rotary shaft. CONSTITUTION:When suction negative pressure in an engine is led into a mixing chamber 9 through a throttle valve 3, an air valve 10 opens slightly up to its opening being balanced with turning force of a spring 13, coming into a state of being idled. At this time, the throttlevalve 3 also comes to idle opening in consequence. And, when the air valve 10 opens up to the specified opening, a needle 16 moves upward as far as the specified extent by rotation of a cam 15 formed in one end of the rotary shaft 11 so that an area of an annular passage between the needle 16 and a seat part 19 narrows whereby a bleed air quantity to be measured decreases. Therefore, the suction negative pressure acting on an air passage 21 and a fuel passage 22 grows large where by a fuel quantity to be measured by a main jet 6 increases as much as a portion for that, thus an air-fuel ratio is controllable. |
