| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable valve timing mechanism which sufficiently secures the endurance of a tappet, a push rod, a rocker arm and a valve seat, in changing a valve timing by making cam profiles in a cam shaft direction of an inlet cam different from each other. SOLUTION: The first and second cam profiles differing from each other are both provided in the cam shaft direction. An inlet valve is operated to open and close based on the first and second cam profiles P, Q. In such a variable valve timing mechanism, configurations of nose tip parts and base circular parts of the first and second cam profiles are conformed to each other, while configurations between the nose tip parts and the base circular parts are made different from each other. Changes in the configuration between the nose tip part and the base circular part of the second cam profile are more gradual than changes in the configuration between the nose tip part and the base circular part of the first cam profile. COPYRIGHT: (C)2003,JPO
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