| 摘要 |
PURPOSE:To obtain excellent combustibility under any circumstances, by employing such an arrangement that correction can be made to strengthen the swirl of intake air when the compression ratio becomes lower than a prescribed value in an apparatus for lowering the compression ratio by increasing the volume of a combustion chamber when knocking of an engine is detected. CONSTITUTION:When knocking of an engine is detected by a knocking detector 22 including a vibration sensor for detecting engine vibration, etc. and a knocking signal S1 is applied from the detector 22 to a control circuit 21, a reference voltage is impressed on an output signal corresponding to the compression ratio measured from a throttle-opening signal and an engine-speed signal. An actuator 20 is controlled by the added signal and operation of a cylinder 10 is controlled by a changeover valve 14 to increase the volume of a variable chamber 8 and to thereby decrease the compression ratio. At the same time, the opening of a subsidiary throttle valve 106 disposed in a secondary intake passage 105b is reduced by a swirl correcting circuit to increase the flow rate of air passed through a primary intake passage 105a and to thereby strengthen the swirl of intake air. |
