Abstract:
A system and method of actuating one or more engine valves is disclosed. In one embodiment, the system comprises: a valve train element; a rocker arm pivotally mounted on a shaft and adapted to rotate between a first position and a second position, the rocker arm selectively receiving motion from the valve train element; a valve bridge disposed above the one or more engine valves; and a lost motion system disposed in the valve bridge.
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:
Cams are formed on a camshaft that correspond to intake valves so that intake flow of an internal combustion engine may be improved. The cams each have a cam lobe and the lobes of different cams are formed in different shapes.
Abstract:
A diesel engine intake cam profile creates two intake valve events separated by a short dwell period each engine cycle. A relatively low valve lift during an engine exhaust event allows a portion of the exhaust gas to flow into an intake manifold and mix with intake air. The intake valve is then nearly closed for a dwell period until a normal intake valve opening occurs, drawing the mixture of air and exhaust gas back into the combustion chamber for compression and burning, upon closure of the intake valves.
Abstract:
An internal combustion cylinder assembly includes a cylinder having a combustion chamber and a piston. An intake valve provides a working fluid to the combustion chamber while the piston moves from a top dead center position to a bottom dead center position. A pre-combustion chamber is connected communicably to the combustion chamber via a Suder valve and conveys a portion of the working fluid to the pre-combustion chamber while the Suder valve is substantially open. The Suder valve may open substantially simultaneously with the intake valve, remain substantially open while the piston moves from the top dead center position to the bottom dead center position during an intake stroke, and close substantially while the piston is returning to the top dead center position during a compression stroke.
Abstract:
Devices for modifying engine valve lift during an engine valve event are disclosed. In one embodiment, the device comprises: a housing having a hydraulic fluid dump port formed therein; a sleeve slidably disposed in a bore formed in the housing, the sleeve having a cavity formed therein; a piston slidably disposed in the sleeve cavity; and a clip passage formed in the piston, the clip passage in selective communication with the dump port.
Abstract:
Valve mechanism in an internal combustion engine, includes a valve play-take up mechanism in the form of a piston in a cylinder chamber at one end of an exhaust rocker arm, and a hydraulic circuit with valve elements for supplying or draining off pressure fluid to and from the cylinder chamber. A second cylinder chamber with a piston acting in an opposite direction is arranged in the rocker arm and communicates with the first-mentioned cylinder chamber. A brake rocker arm is mounted on the same rocker arm shaft as the exhaust rocker arm and has an outer end, which acts against the piston in the second cylinder chamber. The brake rocker arm has its own cam element with brake cam lobes to one side of the exhaust rocker arm cam element.
Abstract:
A valve timing control system for an internal combustion engine, which is capable of accurately and delicately controlling an amount of intake air, and thereby maintaining excellent combustion state and reduced exhaust emissions. The valve timing control system variably controls the valve-closing timing of an intake valve with respect to valve-opening timing of the same as desired via a variable intake valve actuation assembly. The ECU of the engine determined a basic value of a target auxiliary intake cam phase according to the demanded drive torque of the engine. The ECU calculates a control input to the variable intake valve actuation assembly such that the cylinder intake air amount converges to a target intake air amount and at the same time the auxiliary intake cam phase is constrained to the basic value of the target auxiliary intake cam phase.
Abstract:
A variable valve actuation system for providing discrete exhaust and intake valve lift profiles for various operating modes of an internal combustion engine. The variable valve actuation system includes exhaust and intake rocker assemblies, exhaust and intake hydraulic extension devices operatively coupling corresponding rocker assemblies with respective engine valves and exhaust and intake control valves for selectively supplying the pressurized hydraulic fluid to the extension devices so as to independently switch them between a pressurized condition and a depressurized condition. The engine further includes an exhaust brake provided to initiate a small lift of the exhaust valve during the engine braking operation while the exhaust extension device maintains the exhaust valve open during a compression stroke for bleeder-compression release braking. The exhaust and intake valves can be adjusted independently to provide combinations of valve lift modes.
Abstract:
A method of variably actuating a valve of an engine includes selecting one of three valve lift profiles dependent at least in part upon engine operating conditions and parameters. The selected valve lift profile is phased relative to the angular position of the engine crankshaft dependent at least in part upon engine operating conditions and parameters. The valve is actuated according to the selected and phased valve lift profile.