| 摘要 |
PROBLEM TO BE SOLVED: To secure charging efficiencyηv necessary for securing compression self ignition and torque, and appropriate internal EGR ratio m while reducing pumping loss according to change of an operation condition of an engine by expanding variation range of charging efficiencyηv. SOLUTION: An exhaust valve drive means 62 opening an exhaust valve 60 in a middle of intake stroke at a time of valve re-open action and closing the exhaust valve 60 during a period from a vicinity of top dead center over initial stage of compression stroke is provided. An intake valve drive means 43 opening an intake valve 40 in a vicinity of top dead center in an operation zone where at least valve re-opening action of the exhaust valve 60 is performed and closing the same before bottom dead center and enabling to change valve open quantity of the intake valve 40 is provided. Valve re-open action of the exhaust valve 60 is performed with selecting a first valve open period in which valve opening period during intake stroke is long in light load operation zone in operation zone where valve re-open action of the exhaust valve 60 is performed, and a second valve open period in which valve open period during intake stroke is shorter than the first valve open period in heavy load operation zone. COPYRIGHT: (C)2006,JPO&NCIPI
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