| 摘要 |
PROBLEM TO BE SOLVED: To appropriately actuate a brake booster in an internal combustion engine increased in a mechanical compression ratio when the engine is operated under a low load. SOLUTION: This spark ignition type internal combustion engine includes a variable compression ratio mechanism A capable of changing the mechanical compression ratio, and a variable valve timing mechanism B capable of controlling the closing timing of an intake valve. When the engine is operated under the low load, the mechanical compression ratio is maximized so that an expansion ratio becomes 20 or higher. When negative pressure in an engine intake passage is smaller than required negative pressure, the opening of a throttle valve 17 is reduced, and the valve closing timing of the intake valve is controlled so that the quantity of intake air corresponding to the engine load is fed into a combustion chamber according to the opening of the throttle valve. COPYRIGHT: (C)2009,JPO&INPIT
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