| 摘要 |
PURPOSE:To accurately perform knocking control by using a pressure valve which operates on pressure varied according to engine load, so as to make changeover of a pressure control system which has an effect on a vacuum advancer and controlling the negative pressure in said an anchor according to knocking. CONSTITUTION:An ignition timing controller is provided with a solenoid valve 4 whose output port is connected via an orifice 6 to a negative pressure source 5 or connected to the atmospheric pressure. The output port thereof is connected to a vacuum advancer 71 via a pressure valve 8 which changes over the pressure propagation passages according to the negative pressure in a vacuum advance port (advance port) 121. The solenoid valve 4 is changed over under control of a knock controller 3 which detects any occurrance of knocking based on the output of a knock sensor 2. When the negative pressure in the advance port 121 is in both the light load range under 100mm.Hg and the high load range over -100mm.Hg, the pressure valve 8 control to send the atmospheric pressure to the advancer 71 and send a pressure signal, fed via the solenoid valve 4, to the advancer 71, respectively. |
