| 摘要 |
<P>PROBLEM TO BE SOLVED: To concurrently secure both strong swirl and high charging efficiency. <P>SOLUTION: The upper wall surface 14 of an intake port 4 at the intake air inflow passage 8 is formed of a first upper wall surface 14a and a second upper wall surface 14b lower than the first upper wall surface 14a. A lower layer flow passage X and an upper layer flow passage Y are formed on both sides of the top part of the second upper wall surface 14b. A lower layer flow flowing in the lower layer flow passage X produces swirl by flowing in the circumferential direction of a combustion chamber 3 after passing through an intake valve opening area Z when an intake valve 6 is opened. An upper layer flow flowing in the upper layer flow passage Y flows into the combustion chamber 3 after passing through a spiral part 7. <P>COPYRIGHT: (C)2007,JPO&INPIT |
