| 摘要 |
PURPOSE:To vary the opening and closing timing of suction and exhaust valves in a stepless manner and to improve suction efficiency, by a method wherein the swing center point of a locker arm is varied by means of the eccentric amount of an eccentric shaft part, and the lever ratio of the locker arm is changed in a stepless manner. CONSTITUTION:By rotating a locker shaft 1 through the medium of a lever 9 with the aid of an actuator 10, a center O2 of an eccentric shaft part 2, through which a locker arm 3 is pivotally supported to the locker shaft 1, is deviated by a distance ls. This causes the swing center of the locker arm 3, i.e., a lever ratio between the center O2 and the forward end of the locker arm 3 brought into contact with a valve shaft 4 to change in a stepless manner between a low lever ratio l1 and a high lever ratio l'1. Thus, since a valve lift is changed, it is canceled by a relative displacement amount GV occasioned by movement of a forward and backward shaft of a plunger 7, being pressed against the inside of the shaft of an adjust screw 6 through the force of a spring 8 to always hold a valve lift at a specified value. During low speed operation, the lever ratio is brought into the low lever ratio l1, and during high speed operation, it is brought unto the high lever ratio l'1. |
