| 摘要 |
<P>PROBLEM TO BE SOLVED: To attain high torque at by an a high compression ratio engine while efficiently suppressing knocking in the high load range in the lower/middle speed range of the engine in the high compression ratio engine. <P>SOLUTION: The geometrical compression ratio of the engine is set to be the high compression ratio exceeding 12. The branched exhaustion channels connected to the exhaustion ports of the respective cylinders are gathered by the first gathering part in the cylinders themselves where exhausting orders are adjacent, the middle exhaustion channel and in the downstream of the respective first gathering part has the exhaustion manifold gathered in the second gathering part, the exhaustion valve timing mechanism, the ignition timing controller, and the effective compression ratio controller. In the low/middle speed ranges in the high load range, the effective compression ratio is the value exceeding 10, the ignition timing is retarded, the valve opening timing of the exhaustion valve can be changed according to the rotation number of the engine such that the negative pressure wave due to the exhaustion pulsation reaches to the exhaustion port during a valve opening overlap period in a plurality of engine rotation number areas while maintaining the valve opening overlap period for a predetermined period. <P>COPYRIGHT: (C)2012,JPO&INPIT |
