Abstract:
A method to select cylinder and valve operational modes in an internal combustion engine with valves that may be deactivated. A simplified method to select cylinder and valve modes is presented.
Abstract:
A system and method to control engine valve timing of an internal combustion engine. Electromechanical valves are controlled to improve engine fuel economy. Further, the method can adjust valve operation to provide air-fuel charge motion and increase combustion stability.
Abstract:
A method to control valves that may be deactivated during multi-stroke cylinder operation. Valves are controlled to improve drivability and reduce valve degradation.
Abstract:
A switching mechanism capable of switching between a two-stroke and a four-stroke operation of an engine as desired, wherein the switching mechanism is switchable between engagement with a first cam lobe for four-stroke operation and a second cam lobe for two-stroke operation, the four-stroke operation maximizing fuel and emissions efficiency and the two-stroke operation maximizing power.
Abstract:
Hydraulic engine valve actuation systems and methods for internal combustion engines. The systems utilize a proportional valve to regulate the flow of a working fluid to and from a hydraulic actuator controlling the engine valve position. The position of the proportional valve is controlled by one or more high speed valves to control various engine valve parameters, including engine valve takeoff and landing velocities. Returning all valves to a known starting position between engine valve events avoids accumulation of errors in proportional valve positioning. Embodiments using spool valves for the high speed valves and the proportional valve, and spring return and hydraulic return for the engine valve, are disclosed. A specially shaped spool in the proportional valve provides enhanced control over the engine valve operation. Various further alternate embodiments are disclosed.