A fuel injection control device for an engine is provided. A swirl generator generates a swirl flow inside a combustion chamber. A fuel injector with multiple nozzle holes injects fuel into the combustion chamber, and forms a lean mixture gas inside the combustion chamber. An spark plug ignites the lean mixture gas to cause the mixture gas to start combustion accompanied by flame propagation, and then combust by self-ignition. A first atomized fuel spray injected from a first nozzle hole and a second atomized fuel spray injected from a second nozzle hole separate from each other by the swirl flow. The fuel injector sequentially performs first and second injections in an intake stroke. A ratio of an injection amount of the second injection to the entire amount of fuel required per cycle is increased as an engine load increases.

A fuel injection control device for an engine is provided. A fuel injector with multiple nozzle holes forms a lean mixture gas inside a combustion chamber, a spark plug ignites to cause the mixture gas to start combustion accompanied by flame propagation, then combust by self-ignition. A first atomized fuel spray injected from a first nozzle hole and a second atomized fuel spray injected from a second nozzle hole separate from each other by a swirl flow, and a third atomized fuel spray injected from a third nozzle hole and a fourth atomized fuel spray from a fourth nozzle hole approach each other by the swirl flow so that a first area and a second area where mixture gas is richer are formed inside the combustion chamber. The fuel injector sequentially performs first, second, and third injections with an injection interval therebetween in an intake stroke.

The present invention relates to an internal-combustion engine comprising a combustion chamber provided with a single intake valve (2), a single exhaust valve (3), two plugs (4a, 4b) and a fuel injector (5). Furthermore, the combustion chamber comprises means for forming an aerodynamic swirling motion structure of the intake gas in the combustion chamber. Besides, fuel injector (5) is oriented so as to inject the fuel into the central area of the combustion chamber in the direction of the aerodynamic swirling motion structure.

A structure of a combustion chamber for an engine includes: a crown surface of a piston; a combustion chamber ceiling surface formed on a cylinder head; and an ignition plug mounted on the combustion chamber ceiling surface, and including an ignition portion disposed in such a way as to face the combustion chamber. The crown surface of the piston includes a cavity which is recessed in a cylinder axis direction in a region including a position below the ignition portion of the ignition plug in a plan view from the cylinder axis direction. A rim portion of the cavity includes a guide portion, raised in the cylinder axis direction with respect to an inner region of the rim portion, interposing the ignition portion when the piston is at a compression top dead center, and configured to guide an air-fuel mixture within the combustion chamber to the ignition portion.

A combustion chamber structure for an engine includes a combustion chamber where SI combustion by spark ignition and CI combustion by self-ignition are conducted. A crown surface includes a cavity recessed to have a bowl-shape, and a pair of raised portions. The cavity includes a bottom portion which is a lower region of the recessed part, the bottom portion having an outer circumferential edge which is circular in a top view. With a height of the raised portion relative to a height position of a deepest portion of the cavity being represented as H1 and a diameter of an outer circumferential edge of the bottom portion of the cavity being represented as D, H1/D as a ratio of the height H1 of the raised portion to the diameter D of the cavity is set to be in a range of 0.05 or more and 0.36 or less.

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.

An in-cylinder injection engine includes: a cylinder head that includes a gasket surface stacked on a seating face of a cylinder block and defines a combustion chamber between a piston and a ceiling surface gradually receding from an imaginary plane including the gasket surface in going toward a center of the cylinder head; two intake ports disposed side by side and opened in the ceiling surface of the cylinder head; and a fuel injection valve mounted to the cylinder head and having an injection port facing the combustion chamber at a position between an opening of the intake port and the gasket surface. The intake port is formed to have a shape of introducing an airflow laterally into the combustion chamber along the imaginary plane. Accordingly, the in-cylinder injection engine can reduce attachment of injected fuel to a wall surface of a cylinder bore.

The present invention relates to a combustion chamber of a combustion engine. The combustion chamber comprises a single intake valve (2), a single exhaust valve (3), a fuel injector (5) and two plugs (4). According to the invention, the combustion chamber is substantially elliptical (6) and the components of the combustion chamber are arranged as follows: valves (2, 3) are located at the ends of the major axis (8) of ellipse (6), plugs (4) are located close to the minor axis (9) of ellipse (6), fuel injector (5) is located on the periphery of ellipse (6) between intake valve (2) and a plug (4).

An internal combustion engine includes an ignition plug and an electronic control unit. The electronic control unit is configured to: (i) execute a lean-burn operation in a first operation region, (ii) execute an operation in a second operation region at an air-fuel ratio lower than an air-fuel ratio during the lean-burn operation, and (iii) control a gas flow in a cylinder so that a ratio of a change in a gas flow speed around the ignition plug during ignition to a change in an engine rotation speed in a first engine rotation speed region within the first operation region is smaller than the ratio in a second engine rotation speed region within the second operation region.

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.