Selective resetting lost motion engine valve train components

Abstract

Systems and related methods include a rocker arm having integrated components, including a lost motion actuator piston and components for resetting the lost motion actuator piston to provide normal valve closing or late valve closing. Selective reset is facilitated by a reset piston and a blocking piston disposed in a hydraulic circuit including a reset passage. In a non-resetting mode of operation, the blocking piston may block oil flow within the reset passage, regardless of the position of the reset piston, which facilitates late valve closing. An alternative embodiment includes a blocking sleeve disposed concentrically relative to the reset piston.

Description

[0001] Related applications and priority claims [0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 792,507, filed January 15, 2019, entitled "LOST MOTION SELECTIVE RESETTING ROCKER ARM." The subject matter of this provisional application is hereby incorporated by reference in its entirety. technical field [0003] The present disclosure generally relates to systems and methods for actuating one or more engine valves in an internal combustion engine. More specifically, the present disclosure relates to methods for varying the operational relationship between a source of motion (e.g., a cam) and one or more engine valves to provide, for example, an intake valve for use in pushrod engines or space-constrained engines. A system and method of variable valve actuation (VVA) and, for example, providing a two-position intake valve lift, where the first position may be normal valve closing and the second position may be retarded valve closin...

AI Technical Summary

Problems solved by technology

Other systems that are turned off early as the default boost device may have a lower compression ratio at startup, making it difficult to cold start the engine

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