| 摘要 |
PURPOSE:To provide high charging efficiency by shutting off a branch passage at a low-speed and low-load run of an engine to have an ample flow of mixture fed along the upper wall face of a helical part, generating an intense swirl in a combustion chamber, while opening the branch passage at a high-speed and high-load run thereof to supply a great amount of mixture. CONSTITUTION:At a high-speed and high-load run of an engine, a rotary valve 25 is opened so that mixture fed into an inlet passage A is divided into three flows. The first flow flows in between the first side wall face 14a of a wall 12 and the side wall face 17 of the inlet passage A and then flows along the upper wall face 20 of a helical part A in the swirled form, the second flow is led by a branch passage 24 into a helical part B, and the third flow flows along the bottom wall face 21 of the inlet passage A into the helical part B. Because the bottom wall face 22 of said separation wall 12 is a descendent wall, the third mixture flow is guided by the inclined face and swerved to form a downward stream, thereby providing high charging efficiency. |
