| 摘要 |
PURPOSE:To facilitate the production and to ensure the high charging efficiency during a high speed operation by providing a bulkhead protruding downward with a triangular horizontal cross section on the upper wall of a helical type suction port. CONSTITUTION:During the low speed and low load operation of an engine when the intake air volume is small, a rotary valve 20 cuts off a branch path 19, and a part of the air-fuel mixture fed into an inlet passage A proceeds along an upper wall face 8 and the other air-fuel mixture collides with an inclined side wall face 9b, then being applied with a downward force, it flows into a cylindrical outlet section 14 with no rotation. The passage of the air-fuel mixture flowing along the upper wall face 8 is gradually narrowed and it is accelerated. The air-fuel mixture stream is pushed toward the side wall face 10 of a volute section B, in which a strong eddy current is generated, then flowing into a combustion chamber 4. During the high speed and high load operation of the engine when the intake air volume is large, the valve 20 is opened, and a part of the air-fuel mixture fed into the inlet passage section A flows through it then is fed into the volute section B through a branch path 19 with a low resistance, thus the high charging efficiency can be ensured. |
