| 摘要 |
<p>PURPOSE:To reduce the discharged quantity of unburn HC while maintaining high power by setting an overlapping angle between an exhaust valve and an intake valve far from the former larger than an overlapping angle between the exhaust valve and an intake valve adjacent to the former. CONSTITUTION:A multiple valve engine 1 is provided with, e.g. three intake valves 3-5 and two exhaust valves 6, 7 arranged along each circumferential direction at a cylinder head 2 for forming a combustion chamber. In this case, each overlapping angle alpha (theta3+theta4) between both sides intake valves 3, 5 and each of exhaust valves 6, 7 is set smaller than each overlapping angle beta (theta2+theta4) between a central intake valve 4 and each of exhaust valves 6, 7 during an exhaust - intake stroke, and also the intake valves 3, 5 are opened later than the central intake valve 4 by a fixed angle. Further, the valve closing timing of the intake valves 3, 5 is set later than the valve opening timing of the central intake valve 4 by a fixed angle (theta6-theta5).</p> |
