| 摘要 |
PURPOSE:To reduce vibration due to variation in torque at the time of operation with reduced number of cylinders by setting the timing of closing the intake valve of a normally operating cylinder later in an engine which is operated with the number of cylinders reduce at the time of low loading. CONSTITUTION:An intake pipe negative pressure signal S1 and an engine speed signal S2 are inputted in a cylinder number controlling device 15, and shutter valves 11, 12 are closed at a low-load operating area, to stop the operation of the second cylinder 1B and the third cylinder 1C. The timing of intake valves for the first cylinder 1A and the fourth cylinder 1D, which operate continuously is set later than the timing of intake valves for the cylinders 1B, 1C whose operations are stopped. Due to the delayed timing of closing the intake valves, a slight blow-back of intake air occurs, charging efficiency is lowered, and the maximum combustion pressure is reduced. Thereby, variation in torque becomes less, reducing vibration. |
