| 摘要 |
<P>PROBLEM TO BE SOLVED: To stably actuate a rocker arm even when thrust force acts on the rocker arm from a three-dimensional cam. <P>SOLUTION: A slider 18 rotating together with a control shaft 14 and three-dimensional cam lobes 26A and 26B threadably engaged with the slider 18, are arranged on the outer peripheral side of a camshaft 10. The control shaft 14 is rotated by an actuator 16. The cam lobes 26A and 26B are displaced in the axial direction via the slider 18, to change valve opening characteristics of valves 1A and 1B. The cam profiles 28A and 28B are tilted in the opposite directions, and overturning preventive projections 42A and 42B are arranged in the rocker arms 34A and 34B. Thus, opposite thrust forces F1 and F2 are made to act on the rocker arms 34A and 34B, and the thrust forces can be canceled by the overturning preventive projections 42A and 42B. <P>COPYRIGHT: (C)2012,JPO&INPIT |
