473 results about "Engine cycle" patented technology

Methods and systems are provided for a boosted engine having a split intake system coupled to a split exhaust system. Aircharges of differing composition, pressure, and temperature may be delivered to the engine through the split intake system at different points of an engine cycle. In this way, boost and EGR benefits may be extended.

An engine control apparatus is disclosed for determining crankshaft position and engine phase of an internal combustion engine through monitoring intake air pressure fluctuations. The opening of the intake valve is mechanically linked to the crankshaft position of an engine. When the intake valve opens it creates air pressure fluctuations in the air induction system of the engine. The control apparatus is configured to determine intake air pressure fluctuations indicative of an intake air event and thus a particular crankshaft position, and their corresponding period of the engine cycle. The controller then uses this information to determine crankshaft speed and position for the purpose of fuel injection and ignition timing of the internal combustion engine. Engine phase is also determined on four-stroke engines. The engine may also include a crankshaft position sensor in combination with monitoring intake air pressure fluctuations to increase resolution in determination of crankshaft position. A circuit is provided for simultaneously measuring intake temperature using a single bridge type pressure sensor in order to calculate air mass flow rate.

A system and method to control engine valve timing so that an internal combustion engine may be quickly started. Electromechanical valves are controlled to allow an engine to start with reduced cranking time. The method controls intake and exhaust valves without an explicit four-stroke engine cycle during a start.

In one class of fuel injection systems, the individual fuel injectors cycle between high and low pressure during and between injection sequences in a given engine cycle. The fuel injectors may be hydraulically actuated, mechanically actuated, and possibly include common rail injectors equipped with an admission valve that enable the fuel injectors to cycle between high and low pressures. Many of these fuel injection systems also include a directly controlled nozzle valve that can apply or relieve pressure on a closing hydraulic surface associated with the nozzle valve. The nozzle valve is typically spring-biased and therefore has a pre-defined valve opening pressure that defines at what fuel pressure the nozzle valve will open when pressure is relieved on its closing hydraulic surface. While these fuel injection systems can produce a wide variety of rate shapes and injection sequences, generally, an injection sequence of particular interest is one that includes a relatively small volume pilot injection followed quickly in time by a relatively large volume main injection. In order to make the accuracy of the pilot injection more consistent, the nozzle valve is held closed while fuel pressure in the fuel injector builds and surpasses the valve opening pressure of the nozzle valve. This strategy helps to alleviate sensitivity of the pilot injection volume to inherent variability factors, such as geometrical tolerances, within and between fuel injectors.

Toroidal internal combustion engine comprising two concentric engine rings. Intake valves are assembled in two faces of one set of pistons and exhaust valves in two faces of the second set of pistons. The intake-valve pistons are fixedly attached to one of the engine rings and the exhaust-valve pistons to the other engine ring. The face of one intake-valve piston and the face of one adjacent exhaust-valve piston form boundaries of an engine chamber. Combustion forces on the piston faces force the two concentric engine rings to counter-rotate. The intake-valve piston and the adjacent exhaust-valve piston sweep the same chamber volume at different strokes of the engine cycle. The engine is constructed of CRC material and mounted on a central shaft, with the intake manifold and the exhaust manifold mounted on each side of the engine, providing a lightweight, self-lubricating, highly fuel efficient, and dynamically balanced engine.