| 摘要 |
PURPOSE:To control valve lift according to engine speeds, by providing a check ball in an oil communication hole defined between a reservoir and a pressure oil chamber of a hydraulic lifter, and controlling a spring disc with an orifice by means of the check ball to adjust an oil quantity. CONSTITUTION:A plunger body 6 and a lift plunger 2 are provided to form a reservoir and a pressure oil chamber. An oil communication hole 11 is defined between the reservoir and the pressure oil chamber, and a check ball 10 is provided to restrict the oil returned from the pressure oil chamber through the oil communication hole 11 to the reservoir. A spring disc 12 with an orifice 13 is provided on the lower side of the lift plunger 2, and is urged by the check ball 10. In high-speed operation of an engine, a load change is quick, and an quantity of oil returned from the pressure oil chamber to the reservoir is little. Then, an amount of movement of the plunger 2 is reduced to thereby obtain a large valve lift, and increase an output. In low-speed operation, the valve lift is reduced to improve fuel consumption. |
