| 摘要 |
PURPOSE:To improve an output and fuel consumption, by a method wherein a bearing, to which a locker shaft is pivotally secured, is constituted so as to be movable according to an operating condition, position, where a locker arm is supported by the locker shaft, is spaced away from the one end of the locker arm during low speed operation, and conversely, the position is spaced close thereto during high speed operation. CONSTITUTION:A locker arm 2 is supported at its middle part by a locker shaft 3, a suction nd exhaust valve 4 makes contact with the one end of the locker arm, and a cam 5 contacts the other end thereof. Further, the locker shaft 3 is supported by a bearing 6. In which case, a hydraulic servo mechanism 7 is mounted to the bearing 6, and is adapted to axially move a piston 10, the bearing 6, the locker shaft 3, and the locker arm 2 according to the presence of an oil pressure in a pressure chamber 13. A switch valve 18, which is actuated through the working of a controller 17 in response to a signal for the number of revolutions of an engine from a rotary sensor 16, is installed on an oil passage 15 through which a pressure chamber 13 and an oil pump 14 are interconnected. This varies a valve lift according to an operating condition, and causes optimum control of a time area yielded when over-lap occurs during running at a low speed and a high speed. |
