| 摘要 |
<p>PURPOSE:To improve the fuel efficiency of an engine, by providing a communication hole in a partition wall which divides the interior of an intake or exhaust pipe into two longitudinal sections and by providing a valve in the partition wall to open or close the communication hole depending on the load on the engine. CONSTITUTION:The interior of an intake pipe 3 is provided by a partition wall 5 in the longitudinal direction. A hole 6 is provided in the partition wall 5 and fitted with a vale 7. When the valve 7 is open, the total length l2 of the partition wall 5 from the position of an intake valve 8 to the end of the partition wall opposed to an air cleaner 4 has a smaller value l1. In the slow revolution of the engine under heavy load, the valve 7 is closed to heighten the intake efficiency by th effect of inertia. When the valve 7 is opened in the slow revolution of the engine under light load, the time of pulsation of inertial supercharging in the intake pipe 3 and that of closing of the intake valve 8 differ from each other so that the quantity of incoming air to the cylinder decreases. As a result, the pumping loss is eliminated to improve the fuel efficiency.</p> |
