Lost-motion variable valve actuation system with valve deactivation

摘要

Devices and related methods are disclosed that generally involve the selective deactivation of one or more engine valves. In one embodiment, a split-cycle internal combustion engine is provided in which a high-speed trigger valve is used to fill and drain a hydraulic tappet that forms part of a lost-motion system of an engine valve. A spool valve can be used to selectively disconnect the tappet from the trigger valve, thereby deactivating the associated engine valve (i.e., preventing the engine valve from opening). The devices and methods disclosed herein also have application in conventional internal combustion engines and can be used with inwardly-opening and/or outwardly-opening valves.

主权项

1. A valve actuation system, comprising:
a bearing element coupled to an adjustable hydraulic tappet; a cam configured to impart motion to the bearing element and thereby rotate a rocker arm when the bearing element is positioned between an eccentric portion of the cam and a rocker pad formed on the rocker arm; an engine valve coupled to the rocker arm such that rotation of the rocker arm in a first direction is effective to open the engine valve and rotation of the rocker arm in a second direction opposite from the first direction is effective to close the engine valve; a trigger valve having an open configuration in which fluid in the adjustable hydraulic tappet can flow through the trigger valve to a hydraulic accumulator and a closed configuration in which fluid is maintained in the adjustable hydraulic tappet, the trigger valve allowing the adjustable hydraulic tappet to be selectively drained of and filled with hydraulic fluid such that a position of the bearing element can be adjusted; a spool valve having a first configuration in which the adjustable hydraulic tappet is placed in fluid communication with the trigger valve such that the engine valve is activated and a second configuration in which the adjustable hydraulic tappet is hydraulically disconnected from the trigger valve and is instead placed in fluid communication with the hydraulic accumulator such that the engine valve is deactivated; and a solenoid configured to selectively place the spool valve in the first configuration or the second configuration.