| 摘要 |
PURPOSE:To aim at improvements in combustibility in time of low load with a simple structure, by forming at least one unit, among plural suction ports being opened to one combustion chamber, into a swirl port in type and setting up it in a specific position, while bending a suction passage to some extent. CONSTITUTION:Two suction ports 4a and 4b are formed respectively in each combustion chamber 3 in case of plural cylinders, while a suction valve 6 is set up in each of these suction ports 4a and 4b. In this case, one side suction port 4a is made to open toward the tangential direction of a cylinder and to be formed into a swirl port leading air into the tangential direction, while it is set up on an almost nearly extension line of the center axis of a suction passage 9. And, a suction manifold 8 is formed in bend so as to cause its curvature center to be situated at the opposite side to the other side suction port 4b looking from the suction port 4a. With this constitution, suction dynamic pressure is given to the swirl port 4a, and a suction swirl is formed up without installing a complex valve mechanism and a control system, thus combustibility in time of low load is well improved. |
