| 摘要 |
PURPOSE: Valve lifter mounting structure of a vehicle is provided to improve performance of an engine and to reduce noxious exhaust gas by making position of a valve lifter adjustable in accordance with the rpm of an engine. CONSTITUTION: A conical cam(4) is formed in a camshaft(2), and a valve lifter(6) is mounted on the cam while being formed slant to be in contact with the slant face of the cam. Recessed upper end of the valve lifter is in contact with a push rod(8). A position control unit(12) adjusting position of the valve lifter is mounted on the valve lifter to adjust opening degree of a valve(10) according to engine rpm. Upon rotation of the camshaft, a slant portion(14) of the valve lifter contacts with the slant face of the cam by friction and moves up and down. According to up and down movement of the valve lifter and the push rod, the valve is opened and shut off. At a low engine rpm, a hydraulic pump(24) of the position control unit is stopped and a mobile member(22) cannot move. Then, the slant portion of the valve lifter is placed at a right upper portion of the slant face of the cam. At high engine rpm, the hydraulic pump is operated to supply hydraulic pressure to a hydraulic cylinder(20). A piston(30) of the mobile member is pushed, and a rod(32) and an operating plate(34) are pushed to compress an elastic member(28). Then, a long side portion(16) of the valve lifter is pushed. The slant portion is lifted up along the slant face of the cam. Thereby, friction loss is reduced while cam driving power is controlled.
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