| 摘要 |
PROBLEM TO BE SOLVED: To improve intake inertia and volume efficiency by the falling of part of an inward intake air stream from the lower edge of a section wall to the lower side, to reduce the quantity of an inverse swirl stream and to improve a swirl ratio by enlarging the cross-sectional area of a passage in an intake swirl keeping air gap around the downstream side of a port, to increase the power of intake swirl stream at the downstream side of the port during closing of an intake valve. SOLUTION: A lower edge portion at the front end closer to a valve port axial center 9 of a valve port 6, out of a lower edge 25 of a section wall 10, is located closer to the valve port 6, while the lower edge portion at the base end farther from the valve port axial center 9 is displaced to a side farther from the valve port 6. The lower edge 25 of the section wall 10 is formed in one continuous oblique line. The lower edge 25 of the section wall 10 is formed in line almost parallel in a side view with respect to the lower face of a port midstream portion 4 out of a port lower face 17 of a swirl type inlet port 1.
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