| 摘要 |
PURPOSE:To prevent deposition of combustion residue such as carbon in exhaust gas onto a charging valve or the like and thereby prevent a reduction in performance such as fuel consumption, by providing in a cylinder head in opposed relationship to a combustion chamber a valve adapted to be driven by a charging cam for opening and closing an EGR passage. CONSTITUTION:An exhaust valve 15, a charging valve 32 and a third valve 31 are provided in a cylinder head 33 of a 4-cycle engine in opposed relationship to a combustion chamber 14. The exhaust valve 15 is opened and closed in association with rotation of a cam through an exhaust valve rocker arm 35 supported to a rocker shaft 37, while the charging valve 32 and the third valve 31 are opened and closed in association with rotation of a cam through a charging valve rocker arm 34 supported to the rocker shaft 37. The third valve 31 is so located as to open and close an EGR passage 62 communicated with an exhaust passage 61 in the cylinder head 33. The driving operation of the third valve 31 is controlled by a controlled oil pressure 38. Thus, a recirculated exhaust gas is directly supplied from the third valve 31 into the combustion chamber 14, thereby preventing that a sectional area of a charging passage will be reduced by deposition of combustion residue such as carbon in the exhaust gas.
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