| 摘要 |
PURPOSE:To improve the accelerator pedal operating feeling, by selecting the diameter of a bore on the primary side at a particular value with respect to the displacement of an above-titled engine equipped with a two-barrel carburetor. CONSTITUTION:In case of operating an internal-combustion engine by producing a fairly lean air-fuel mixture in a two-barrel carburetor having a primary bore 10 and a secondary bore 12 provided with respective throttle valves 14, 16 while keeping the air-fuel ratio during normal operation of the engine at a value far greater than the theoretical air-fuel ratio, the diameter Dp of the primary bore 10 is selected as follows. That is, providing that the displacement of the engine is V(l), the diameter Dp is selected at a value greater than the value determined by an equation, Dp=26+4.5V. With such an arrangement, it is enabled to obtain a sufficient engine torque, in particular, in a low-load and a medium-load regions and therefore to improve the accelerator pedal operating feeling in the above load regions. |
