| 摘要 |
PURPOSE:To shift the operation state smoothly to idling state by a mechanism wherein air is supplied from the region, revolution thereof is void of fear for engine failure under fully closed state of shutter valve in the air suction device equipped with shutter valve system. CONSTITUTION:When the throttle valves 5, 6 are closed to the opening extent of idling during an idling operation, the throttle switch SW1 turns the contact SW1b of the switch SW2 for the first number of rotation on, and the electromagnetic valves 25, 31 are turned on. Thus the negative pressure suction air taken from the negative pressure air passage 21b is introduced into the negative pressure chamber 19a of the diaphragm unit 19 through the passages 27, 21, and the shutter valve 7 is full closed. In the range of set value or less, in which the number of rotation of engine is greater than that of idling a little, the valve 15 of air feed passage 16 is opened to supply air from the feed port 9. When accelerated from this state, the air feed is stopped due to the number of rotation less than said set value. |
