| 摘要 |
PURPOSE:To improve the operation performance of an engine having at least three intake valves, by making it possible to sequentially put two intake valves out of operation depending on the change in the quantity of intake air. CONSTITUTION:Three intake valves 2 are installed at one side of the cylinder 1 of an engine. Two exhaust valves 3 are installed at the other side of the cylinder 1. In the rapid rotation of the engine, the three intake valves 2 are put in operation so that an output characteristic curve A is attained. When the quantity of intake air has become a predetermined value as a result of the deceleration of the engine, one of two stoppage means 4 is operated by a control signal to put one intake valve 2 out of operation and keep the other two in operation to attain an output characteristic curve B. When the quantity of intake air is reduced further, the other stoppage means 4 is also operated to keep only one intake valve 2 in operation to attain an output characteristic curve C. For that reason, the resultant output characteristic curve has three protrusions. The change in the output characteristic is thus made relatively small. |
