| 摘要 |
PURPOSE:To prevent air-fuel mixture from becoming excessively dense during deceleration, by a method wherein, in a suction device comprising plural intake air passages and an on-off valve which is partially opened and closed, intake air is guided to the down stream side of a throttle valve during deceleration, and the on-off valve is opened to a given size. CONSTITUTION:During deceleration in which a throttle valve 12 is rapidly closed, a high negative pressure in generated in a main intake air passage 11 down a line from the throttle valve 12, a rod 25 of a diaphragm device 26, which the normally depressed through the force of a spring, is pulled up, and an on-off valve 18 is controlled in a closing direction. Simultaneously, a control valve 35, which is opened at higher than a given negative pressure, is opened, and thereby a negative pressure is guided to a diaphragm device 34 through a passage 36 to open the throttle valve 12 to a given opening, and intake air is increased. Opening of the valve 35 results in opening of the valve 33 by means of a negative pressure guided to a diaphragm valve 33, and the open air is guided to a passage 32 communicated with a pressure chamber 31 in the diaphragm device 26, and this causes the on-off valve 18 to be opened to a given size. |
