VARIABLE LOST MOTION VALVE ACTUATOR AND METHOD

摘要

Lost motion engine valve actuation systems and methods of actuating engine valves are disclosed. Exemplary systems may include a valve train element, a first lost motion piston, an accumulator, and a hydraulic circuit, among other components. Variation of the first lost motion piston position may be carried out by placing the first lost motion piston in hydraulic communication with a trigger valve and one or more accumulators. Actuation of the trigger valve releases hydraulic fluid allowing for adjustment of the first lost motion piston position.

主权项

1. A hydraulic lost motion system for controlling the operation of at least one engine intake valve for an internal combustion engine, the system comprising:
a) a first piston slidably disposed in a first piston chamber in a housing of the hydraulic lost motion system, the first piston being moveable in response to rotation of an engine cam shaft, and being configured to interact with at least one engine intake valve for movement of the engine intake valve in response at least in part to the position of the first piston; b) an accumulator including an accumulator piston slidably disposed in an accumulator piston chamber defined at least in part in the housing, the accumulator piston being biased toward an end of the accumulator piston chamber by a spring; c) a trigger valve in hydraulic communication with the first piston chamber, the trigger valve including:
i) an electromagnetic solenoid coil defining a longitudinal central axis;ii) an armature mounted for movement relative to the electromagnetic solenoid coil in a direction generally along the longitudinal central axis of the coil and movable between a retracted and an extended position when the electromagnetic solenoid coil is electrically actuated;iii) a solenoid pin connected to the armature for movement along with the armature in a direction generally along the longitudinal central axis of the coil;iv) a trigger valve piston being configured to selectively block fluid flow along a fluid path connecting the first piston chamber and an associated accumulator piston chamber the trigger valve piston including a first end adjacent to and engageable by a first end of the solenoid pin, a second end opposing the first end, and a side wall between the first end and the second end for enabling blockage of fluid flow along the fluid path;v) the trigger valve piston being movable from a first position enabling fluid flow along the fluid path to a second position blocking fluid flow along the fluid path when the electromagnetic solenoid coil is energized urging the first end of the solenoid pin against the trigger valve piston to cause the trigger valve piston to move from its first position to its second position;vi) wherein when the trigger valve piston is in its second position, the side wall of the trigger valve piston extends across at least a portion of the fluid path to block fluid flow along the fluid path, with the side wall of the trigger valve piston being the only portion of the trigger valve piston that is exposed to hydraulic fluid pressurized by the first piston when the first piston is advanced into the first piston chamber by the engine cam shaft; and e) a micro-processor controller operatively associated with the engine and configured to generate an electrical signal for actuating the electromagnetic solenoid coil to move the trigger valve piston to its second position to block fluid flow along the fluid path between the first piston chamber and the associated accumulator piston chamber for controlling the movement and the timing operation of the at least one engine intake valve.