| 摘要 |
PURPOSE:To enable to quickly control the number of cylinders in action at an appropriate time by a method wherein rocker arms are displaced in the direction of the axis of a rocker shaft by means of hydraulic actuators so as to change the engaging position with respect to cams in order to actuate and stop suction valves and exhaust valves. CONSTITUTION:The number of cylinders in action is controlled by putting suction valves and exhaust valves 1 and 2 into acutation and out of actuation in such a manner that rocker arms 23 and 24 are shifted in the direction of the axis of a rocker shaft 20 in order to bring into selective engagement with either one of a pair of cams 21 and 22, both of which are formed onto the rocker shaft 20 and have profiles different from each other. The rocker arms 23 and 24 are shifted by means of hydraulic actuators 29 and 30 in the above-mentioned device. The respective actuators 29 and 30 are connected through a directional control valve 40 to the delivery circuit and the tank circuit of an oil pump 33. The change-over action of said directional control valve 40 is controlled by a stopper 50 energized by a timing lifter 52. A hydraulic clutch 59, which is changed-over in accordance with the running conditions of an engine, is interposedly provided in a driving system between the stopper 50 and the lifter 52. |
