| 摘要 |
An intake plenum arrangement for an air intake system of a multi-cylinder internal combustion engine, eg a V6 or V8 engine, comprises first and second plenums 16,17 interconnected by a plenum connecting pipe 24. A first set of inlet runners 18,19,20 delivers charge air from the first plenum 16 to a first plurality of combustion chambers 10,11,12 while a second set of inlet runners 21,22,23 delivers charge air from the second plenum 17 to a second set of combustion chambers 13,14,15. The plenum connecting pipe 24 is provided with a cross-section adjusting mechanism 25 which can adjust in size the cross-sectional flow area of the pipe 24 and also a length adjusting mechanism 30 which can adjust the flow length of the pipe 24. A control system 25 is provided which controls the cross-section adjusting mechanism 25 and the flow length adjusting mechanism 30 in accordance with changes in engine speed and/or load, eg the cross-section is varied for engine speeds only in the range 2500 to 4500 rpm. |
