| 摘要 |
PURPOSE:To aim at improvement in both driving and fuel consumption characteristics, by controlling the ignition timing according to air-fuel ratio variations, in case of an ignition timing control method for super-lean combustion type internal-combustion engines. CONSTITUTION:Judging on whether it is at a high load or not on the basis of a throttle valve opening THR obtainable from a throttle position sensor 15, a fuel increment coefficient beta corresponding to the throttle opening is evaluated in time of high loading. In addition, an ignition timing compensation value alpha is evaluated from the fuel increment coefficient and an engine speed N as shown in illustration. When it is not at a high load, the fuel increment coefficient beta is regarded as 1 and the ignition timing compensation value is set down to 0. Likewise, an air-fuel ratio is sharply raised to be rich in accordance with a state of loading in time of high load while the ignition timing is delayed in control so that high torque in time of high load can be obtained. |
