| 摘要 |
Electro-hydraulic engine valve actuation system providing an actuator and an actuator control system. The actuator includes primary and secondary actuation chambers, defined by a piston, connected to the engine valve, and characterized by increasing and correspondingly decreasing chamber volumes, as the piston is urged away from neutral position. A fluid inlet is connected to a flow control valve. A control valve includes an actuator, and has flow states for controlling flow between two fluid inlets and a fluid outlet. The control valve includes first and second opposed, control chambers, each connected to the actuator. There is a spring in the second control chamber. The actuator of the flow control valve is controlled to a first and second state, and there is an electrically uncontrolled third flow state. There is a pair of temperature-compensated orifices which create internal feedback, with the control chambers, between the engine valve motion and the control valve position.
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