| 摘要 |
PURPOSE: To improve operability during lean combustion operation by a method wherein even when the formation position of an intake port is deviated due to a manufacture tolerance, proper swirl ratio and tumble ratio are ensured. CONSTITUTION: When an intake passage 21 and an intake port 6 are interconnected in a reference position relation, a first side part 21A1 positioned on the notch part 22c side of the intake control valve 22 of the two side parts 21A1 and 21A2 in a lateral direction of a connection port 21A is set in such a manner to be positioned more outside in a lateral direction by a given sizeδthan an opening part 6C on the upper stream side and this way forms a stepped part 23. Thus, even when the formation position of the intake port 6 is deviated in the direction of either the notch part 22C side or the opposite side to the notch part 22C due to an error of manufacture by casting, a swirl ratio and a tumble ratio are hardly lowered and substantially proper swirl ratio and tumble ratio are ensured.
|
