| 摘要 |
PURPOSE:To improve filling efficiency over the whole operating range of an engine by making two intake pipes of the engine having two intake valves for one cylinder different in length, providing a switching valve on the short pipe, and communicating both pipes downstream it via an intake control valve. CONSTITUTION:Two intake valves 6A, 6B are provided on one cylinder, and a long intake pipe 7A and a short intake pipe 7B are connected to the intake valve 6A and the intake valve 6B respectively. The first intake control valve 18 is provided on the intake pipe 7B, and both intake pipes 7A, 7B are communicated via a communicating hole 29 provided with the second intake control valve 30 downstream it. At a high rotating speed of an engine, both valves 18, 30 are opened by a control circuit 47, the inertial intake suitable for a high rotation speed particularly through the short pipe 7B is performed also to the other side via the communicating hole 29. At a medium load, only the valve 18 is closed, and the inertial intake through the long pipe 7A is performed also to the other side via the communicating hole 29. At a low load, the valve 30 is also closed, and the intake is performed only through the valve 6A side, and a reliable swirl is generated. |
