| 摘要 |
PURPOSE:To prevent output, drivability and fuel consumption from being worsened, by making an increase of advance angle of the ignition timing as a quantity of EGR increases, with said increase raising a speed of combustion. CONSTITUTION:When a throttle valve is fully closed and in a slight degree of opening, an EGR valve 7, vacuum angle advancing device 16 and control valves 29, 36 are not operated with an operation of EGR not made, and an angle advancement of the ignition timing is also not operated. By an increase of the load, with the throttle valve made opening to above a prescribed degree of opening a negative pressure, working on a negative pressure chamber 10, goes lower with a quantity of EGR controlled to a small amount. On the other hand, though a degree of advanced angle is small, the most suitable degree of advanced angle is made for that condition because of a less quantity of EGR. Subsequently, when becoming a time of speed acceleration or high load operation, a negative pressure, working on the negative pressure chamber 10, goes higher with a big quantity of EGR operated. And with a negative pressure fed to a negative pressure chamber 18, a bigger degree of advanced angle of ignition is provided. |
