INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To restrain deterioration of a combustion condition caused by ununiformity of exhaust in an internal combustion engine wherein a exhaust valve is opened temporarily during an intake stroke to mix the exhaust into intake air in a combustion chamber. SOLUTION: A main lift part for opening the exhaust valve 18 during an exhaust stroke, and a sub-lift part for opening temporarily the valve 18 during the intake stroke are formed in a cam for opening and closing the exhaust valve 18. Plural fins 19 are provided on a reverse face positioned in an exhaust port 16 side in a shade part 18b of the exhaust valve 18 to change a flowing direction of the exhaust flowing into the combustion chamber 14 to the prescribed direction so as to impart turning force to the exhaust.