| 摘要 |
<p>An engine cycle control system controls an engine so that it operates in a two-cycle mode when the rotational speed of the engine is lower than a predetermined speed and in a four-cycle mode when the rotational speed of the engine is higher than the predetermined speed. The engine controlled by the engine cycle control system (5) has intake ports (13) defined in a lower circumferential surface of a cylinder (1), an exhaust port defined in an upper portion of the cylinder and openable and closable at variable timing, and a fuel injection valve (22) for injecting fuel into the cylinder at variable timing and in a variable quantity. Depending on the rotational speed of the engine, the timing of operation of an exhaust valve is varied to select the two-cycle mode or the four-cycle mode. The engine is associated with a turbocharger (4) combined with an electric motor (43). In a large-load range in the two-cycle mode, the electric motor is energized to assist in turbocharging operation for thereby increasing the torque produced by the engine.</p> |
