| 摘要 |
A timing mechanism to control valves to provide variable valve timing (VVT), variable valve actuation (VVA) and variable valve duration (VVD) is disclosed. The VVT mechanism comprising care means 1, 2, a cam follower 4, 5 arranged to engage the cam means 1, 2 and a linkage 7 connected at one end to the cam follower through a pin/bearing 23, 24 which may slide in an arc about the care axis and at the other end to a rocker arm 6 to actuate a valve of the engine such that movement of the pin means along the arcuate locus advances or retards the valve timing. A VVA mechanism which comprises a further rocker arm(s) that is slidingly moveable on an arcuate locus that increase/decrease the amplitude of the actuation is also disclosed. Also disclosed is a VVD mechanism comprising of a double pair of cam followers engaging cam means of which one pair of cam followers is rotatable about the care linkage. Differential inputs in form of pinion gears meshed with racks along the cam follower linkage are used to adjust the pin position. |
