| 摘要 |
PURPOSE:To improve combustion to reduce noise, by feeding air for weakening the strength of intake air swirl provided in an intake port upon acceleration of an engine. CONSTITUTION:There are formed an intake port 3 having a shape with which a high swirl is formed for an intake valve and an air passage 5 for supplying air in the direction in which the swirl is cancelled. A shut-off valve 6 is provided in the upstream section of the air passage 5, and pressure fluid from a pressure accumulating source 11 is fed into a fluid cylinder 10 upon opening of a valve 12 to close the valve 6. Upon abrupt acceleration of the engine a sensor 9 detects the changing rate of depressed angle of an accelerator pedal, and delivers a signal with which a shut-off device 14 opens the valve 12 so that the shut-off valve 6 is closed in association with the operation of the actuator 10 to reduce the swirl, thereby it is possible to enhance the combustion upon transient operation of the engine. |
