| 摘要 |
A combustion engine comprises a cylinder 10, one or more intake flow paths 12, 14 with one or more intake valves, two exhaust flow paths 16,18 with one or more exhaust valves and means to delay the closing time of at least one exhaust valve into the induction stroke to induce internal EGR, i.e. allow exhaust gas to flow back into the cylinder 10. The inlet paths 12, 14 are configured to create swirl of the inlet charge. Obstruction means 24 is provided in one exhaust path to prevent exhaust gases flowing back along it into the combustion chamber while the second path is configured to permit reverse flow of the exhaust gases and to enhance the swirling motion of the charge in the cylinder 10. The engine may be operated using fixed or variable valve timing. |
