| 摘要 |
PURPOSE:To provide excellent charging efficiency when an engine is running at a low or medium speed by cutting off the inflow of intake air after an intake valve is opened and then beginning its inflow before the above valve is closed. CONSTITUTION:An intake control valve 9 is kept on fully closed condition up to 140 deg. after passing a top dead center when an engine is running at a low speed, and intake air is not fed into a combustion chamber 5 when an intake stroke is begun and an intake valve 6 is opened. Positive pressure in a cylinder lowers and negative pressure there enlarges as a piston 3 goes down, and since a pressure difference between in an intake path 8 and in the combustion chamber 5 enlarges when the intake control valve 9 is fully opened, the great amount of the intake air flows straight at a high speed into the combustion chamber 5. In order to make the positive pressure generated in the combustion chamber 5 the highest, the fully opened time of the intake control valve 9 must be advanced as the number of revolutions of the engine increases. |
