| 摘要 |
PURPOSE:To improve accelerating ability, by a method wherein a pulsating pressure in the crank chamber of a 2-cycle engine is introduced through a laterally- extending through-hole in a throttle valve shaft only during full opening of a throttle valve to actuate an accelerator pump made of a flexible film, and the fuel is forcibly injected through a high-speed fuel injection nozzle. CONSTITUTION:After a diaphragm type carburetter sucks the fuel through a fuel pump diaphragm 4 with the aid of a pulsating pressure fed from a crank chamber to a feed-in port 3, the fuel is fed under a pressure toward a flow-in valve 7. Opening of the flow-in valve 7 is controlled through a metering diaphragm 8, and a butterfly throttle valve is rotatably disposed around a throttle valve shaft 16 in a throttle valve hole 15 in a carburetter body 1. In which case, a crank chamber pulsating pressure passage 23 is adapted to be communicated with an outer peripheral air chamber 26 of a long bag type accelerator pump 25 through a laterally-extending through-hole 24, formed in a throttle valve shaft 16, during full opening of a throttle valve. The accelerator pump 25 is actuated by means of said pulsating pressure, and the inner fuel is forcibly injected through a high- speed fuel injection nozzle 20. |
