| 摘要 |
PROBLEM TO BE SOLVED: To reduce HC discharge quantity by reducing fuel close to a cylinder wall surface of a combustion chamber in an internal combustion engine in which swirl combustion can be performed to achieve favorable fuel consumption. SOLUTION: A swirl control valve 6 which is closed in low load operation is provided on a first intake port 3, as in an ordinary internal combustion engine in which swirl combustion is performed, and a protrusion 13 to convert a direction of intake air to be introduced in the tangential direction relative to a cylinder wall surface 5a of a combistion chamber 5 is provided on a second intake port 4. The protrusion 13 has a through hole 16 to be directed to a spark plug 14, so part of fuel mist injected from a fuel injection valve 9 is directly introduced toward the spark plug 14 nearby. Otherwise, a step 17 may be formed to positively introduce intake air or fuel mist to an inlet of the through hole 16. Fuel around the spark plug 14 is thus increased, and ignition performance and combustion conditions are improved, thereby fuel around the cylinder wall surface 5a is reduced to decrease HC discharge quantity. |
