| 摘要 |
PURPOSE:To control the air-fuel ratio with high accuracy, by correcting the volumetric efficiency by the product of the quantity of correction according to the negative pressure and that according to the engine speed in a fuel injection apparatus which is designed to supply fuel on the basis of the flow rate of intake air measured from the negative pressure in an intake pipe and the engine speed. CONSTITUTION:Representing the engine speed, negative pressure and volumetric efficiency of an engine respectively at the X-axis, Y-axis and Z-axis, the volumetric efficency is represented in a monotonous curved surface. In a high-output range (-100- 0mm.Hg), however, change of the volumetric efficiency is great as compared with that in an ordinary range of operation (-100--500mm.Hg). Here, if the volumetric efficiency is calculated from the product of a one-dimensional map of the negative pressure and that of the engine speed mapped over the entire operational range of engine, an approximation error greater than 5% is produced in a high-out-put range. In order to overcome this problem, the volumetric efficiency is approximated in the high-output range by making product of the one-dimensional mapped by a different engine speed and that of the negative pressure using the same value, whereby it is enabled to reduce the approximation error to about 2%. |
