| 摘要 |
PURPOSE:In an internal combustion engine wherein a bypass passage is running aside, a throttle valve is disposed, in order to improve fuel consumption in a light load range, by providing a flow control valve controlled by a intake negative pressure, in the bypass passage. CONSTITUTION:A mixture flowing through an intake passage P1 into a combustion chamber R of an engine 10 is stirred by air running through a bypass passage P2 into the vicinity of an intake valve 13, so that it may be mixed more evenly. The mixture is swirled in the combustion chamber R, for expediting its combustion. A flow control valve 40 intervenes in the bypass passage P2 in the so-constituted internal combustion engine. The flow control valve 40 includes a spool 42 which is pulled against a spring 43 under an effect of intake negative pressure, to slide downstream inside a small-bore hole 41c downstream a valve housing 41. A wedge- shaped cavity 42c is shaped in the spool 42 at the downstream end, gradually expanded toward the downstream, thereby reducing the bypassed air amount in a light load range. |
