| 摘要 |
The present invention provides, an internal combustion engine comprising at least one piston (19) reciprocating with a cylinder (20) and having an exhaust port (23) allowing communication of the cylinder (20) with an exhaust passage. Movable shutter means (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) is provided to vary the effective area of the exhaust port (23). Sensor means generate signals corresponding to operation characteristics the engine and the signals are processed by a control unit (11) which controls the shutter means (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) accordingly. In a preferred embodiment as shown the shutter means (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) varies the effective area of the exhaust port (23) in timed relationship to reciprocal motion of the piston (19). |
