An engine system is provided, including a controller which estimates a mass ratio (G/F) of intake air inside a cylinder (containing fresh air and burnt gas) to fuel, and controls devices of an engine at a given engine speed so that, while a demanded engine load is a first load, at least part of a mixture gas inside the cylinder combusts by flame-propagation when the estimated G/F is below a first G/F, and the entire mixture gas combusts by compression ignition when the estimated G/F is above the first G/F, whereas while the demanded load is a second load (>the first load), at least part of the mixture gas combusts by flame-propagation when the estimated G/F is below a second G/F (<the first G/F), and the entire mixture gas combusts by compression ignition when the estimated G/F is above the second G/F.

An internal combustion engine includes a fuel injection nozzle in which a nozzle hole that injects fuel is provided to be exposed to a combustion chamber from a cylinder head of the internal combustion engine, and a hollow duct in which an inlet and an outlet are exposed to the combustion chamber. The duct is provided to penetrate through an inside of the cylinder head so that fuel spray injected from the nozzle hole of the fuel injection nozzle passes from the inlet to the outlet. The duct is preferably configured so that a direction from the inlet to the outlet corresponds to a direction of the fuel spray injected from the nozzle hole.

An internal combustion engine system includes an engine housing having a combustion cylinder, and a piston movable within the combustion cylinder to increase a pressure therein to an autoignition threshold for injected fuel. The piston includes a piston crown having a combustion face forming a combustion bowl, and varied in profile to form jet-jet interaction limiters at locations offset from fuel spray jet paths from a fuel injector. The jet-jet interaction limiters include a bowl component and a step component protruding, respectively, within the combustion bowl and a step located transitioning between the combustion bowl and a circumferential rim of the piston. Limiting jet-jet interaction limits soot production in exhaust produced by the engine.

A piston for an internal combustion engine is provided. The piston includes a piston bowl defined by a floor surface and a rim wall extending from an outer periphery of the floor surface in a system vertical direction to circumferential surround the floor surface. The piston bowl includes a center portion that extends above the floor surface. A plurality of protrusions extend radially from the center portion and from the floor surface and are spaced apart such that a spray guide is formed between each of the spaced apart plurality of protrusions. Each of the plurality of protrusions and spray guides are tapered so to terminate prior to the rim wall such that a continuous radius portion is formed from a portion of the rim wall and a portion of the floor surface beyond a respective terminating portion of each of the plurality of protrusions and spray guides.

An engine is provided, which includes a combustion chamber defined by a cylinder head and a piston inside a cylinder of a cylinder block, a fuel injection nozzle provided to the cylinder head and formed in a tip-end part with a plurality of injection holes from which fuel is injected into the combustion chamber, the tip-end part being exposed to the combustion chamber, and a passage-forming member formed with a passage through which the injected fuel passes. The injection holes include first and second injection holes, and the passage-forming member is disposed around the tip-end part of the nozzle so as to cause a difference between a speed at which fuel injected from the first injection hole flows toward a circumferential part of the combustion chamber, and a speed at which fuel injected from the second injection hole flows toward the circumferential part.

The present invention discloses an apparatus for optimizing the fuel/air mixing process of an internal combustion engine. The bottom surface of the cylinder head is provided with a plurality of brackets; a ring is fixed to the brackets; and the ring may be an integrated ring body and may also be composed of a plurality of small segments. The ring is positioned opposite to a fuel injector and located in an area where fuel flows in the the combustion chamber. The ring can continuously guides the fuelduring the fuel injection process. The ring can be arranged in the liquid-phase region, the gas-liquid two-phase region or the gas-phase region. When the location of the ring interferes with the movement of valves of the internal combustion engine, the part of the ring body that interferes with the movement of the valves can be removed.

Embodiments of apparatus are disclosed for affecting working fluid flow in a system that delivers material between two locations by carrying the material in the working fluid. For example, embodiments of the disclosed apparatus may be used in an internal combustion engines to carry fuel droplets to a combustion area using air as the working fluid. The apparatus may include a passage including a funnel portion and tumble area that direct working fluid into a stratified stream. The stratified stream may include an outer boundary flow having a toroidal and/or helical flow characteristic and an inner flow carrying injected material that is bound by the outer flow.

Various methods and systems are provided for a fuel injector. In one example, a fuel injector includes a nozzle tip including a plurality of injection holes, a first needle biased against the nozzle tip via a first biasing member positioned within a first control volume, and a second needle surrounding a portion of the first needle and biased against the first needle and the nozzle tip via a second biasing member positioned within a second control volume. A needle actuator may be energized for different durations of time in order to move one or more of the first needle and the second needle relative to the nozzle tip.

A piston for use in a GDCI engine cooperates with the wall of a cylinder defined in the engine and with a cylinder head to define a combustion chamber. The surface of the piston that faces the cylinder head defines a bowl that is configured to receive fuel that is dispensed from a fuel injector that is located in the cylinder head substantially along the central axis of the cylinder. The bowl is configured such that substantially all of the injected fuel associated with a combustion event reaches a localized equivalence ratio greater than 0.0 and less than or equal to 1.2 at a time immediately preceding initiation of the combustion event.

A piston for use in a GDCI engine cooperates with the wall of a cylinder defined in the engine and with a cylinder head to define a combustion chamber. The surface of the piston that faces the cylinder head defines a bowl that is configured to receive fuel that is dispensed from a fuel injector that is located in the cylinder head substantially along the central axis of the cylinder. The bowl is configured such that substantially all of the injected fuel associated with a combustion event reaches a localized equivalence ratio greater than 0.0 and less than or equal to 1.2 at a time immediately preceding initiation of the combustion event.