| 摘要 |
PROBLEM TO BE SOLVED: To reduce a torque variation by restraining a variation in the air-fuel ratio of a spitting air-fuel mixture to an intake passage, and to improve fuel economy performance by reduction in a pumping loss, by devising a valve operation characteristic of an intake valve for spitting the air-fuel mixture to the intake passage, in an internal combustion engine. SOLUTION: A valve characteristic variable mechanism Aa of a valve gear V of the internal combustion engine, selects a low speed cam 21i and a decompression cam 24 as a specific cam from a plurality of cams 21i-23i and 24 for constituting a cam group 20i when an engine speed is a specific operation state of an idling engine speed or more. The low speed cam 21i controls a first intake valve 10a so as to become a valve opening state in the vicinity of the exhaust top dead center, and the decompression cam 24 controls a second intake valve 10b so as to open by a maximum lift quantity smaller than a maximum lift quantity of the first intake valve 10a, and to open over a compression stroke from the latter half of an intake stroke. COPYRIGHT: (C)2011,JPO&INPIT
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