| 摘要 |
PURPOSE:To bring an inertial supercharging effect into full play even in medium and high speed zones as well to aim at a torque improvement, by installing each manifold to be connected to each suction port at both setting and nonsetting sides of a suction interrupting device, while selecting each of their interconnecting passages for opening or closing with a control valve. CONSTITUTION:In a low speed zone of an engine, an on-off valve 14 is closed, and suction air is fed to the inside of a combustion chamber from only first suction valves 11A by way of first suction ports 12a and each cylinder from a first manifold 15. And, with natural frequency of an air column depending on each passage form of branch parts 15 of the first manifold, such inertial supercharging as being matched to a low speed zone is favorably carried out. On the other hand, in both medium and high speed zones of the engine, the on-off valve 14 is opened, and air-charging is carried out even from second suction valves 11B by way of a second manifold 16 and second suction ports 12B. At this time, if a control valve 20 is closed, the interference of suction pulsation to be produced each at each of these manifolds 15 and 16 is preventable, thus such a torque characteristic as utilizing the inertial supercharging by branch parts 16 of the second manifold 16 is securable. |
