| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable valve system capable of realizing sufficiently low friction, achieving low fuel consumption, and improving performance of an internal combustion engine in all the rotation ranges in spite of use of direct strike type valve lifters. SOLUTION: Change-over mechanisms 16, 26, 36, etc., for connecting and disconnecting valve lifters 10 and 20 for low speed and a valve lifter 30 for high speed to/from each other are provided in such a way that valves 7 and 8 are opened based on pressure on the valve lifters 10 and 20 for low speed by cams 1 and 2 for low speed in a low speed range, and that the valves 7 and 8 are opened based on pressure on the valve lifter 30 for high pressure by a cam 3 for high speed in a high speed range. On at least either of the valve lifters 10 and 20 for low speed and the valve lifter 30 for high speed, rollers 15, 25, and 35 with which the cams 1 and 2 for low speed or the cam 3 for high speed slide to get in contact are pivotally mounted to be rotatable.
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