A compression ignition internal combustion engine includes: a cylinder block and a cylinder head; a piston including a cavity that defines a combustion chamber in cooperation with the cylinder block and the cylinder head; and a nozzle for injecting fuel into the combustion chamber.

An anti-polishing ring includes a ring body defining an axis of revolution, and a radial direction that is perpendicular to the axis of revolution, and a circumferential direction about the axis of revolution. The ring body includes an outer circumferential surface, a bottom surface, a top surface, and an inner circumferential surface. The inner circumferential surface defines an inner diameter, the ring body defines a radial thickness measured from the inner circumferential surface to the outer circumferential surface, and a ratio of the radial thickness to the inner diameter ranges from 0.015 to 0.020.

The present disclosure relates to a combustion chamber of a diesel engine, which has a recessed combustion bowl to mix fuel injected from an injector with air, the combustion chamber including: a cylinder head which has the injector mounted thereto and is positioned at an upper side of the combustion bowl; a cylinder block which is positioned at a lower side of the cylinder head; and a piston which moves upward and downward in the cylinder block and faces the cylinder head, in which a plurality of radial inducers is provided on a bottom surface of the cylinder head around the injector.

An engine system capable of controlling an intake air flow includes a combustion chamber, an ignition plug, an intake air flow control valve, and a controller. The controller performs, in at least a part of an operating range, SPCCI combustion in which after jump-spark ignition combustion of a portion of a mixture gas inside the combustion chamber by a jump-spark ignition of the ignition plug, compression ignition combustion of the remaining mixture gas is carried out by a self-ignition. The controller strengthens, at least in a part of the operating range of SPCCI combustion, the intake air flow inside the combustion chamber by controlling the intake air flow control valve. The controller controls, in a middle-load range of the operating range where SPCCI combustion is performed, the intake air flow control valve so that the intake air flow becomes weaker than in a high-load range and a low-load range.

A galleryless piston having a reduced weight and a reduced operating temperature is provided. The piston includes an undercrown surface exposed from an underside of the piston, a ring belt, pin bosses each presenting a pin bore, and skirt panels depending from the ring belt and coupled to the pin bosses by strut. The piston further includes an inner undercrown region extending along the undercrown surface and surrounded by the skirt panels, the struts, and the pin bosses. The piston also includes outer pockets each extending along the undercrown surface and each surrounded by a portion of the ring belt, one of the pin bosses, and the struts coupling the one pin boss to the skirt panels. Cutouts are located in the pin bosses above the pin bores to increase the area of the undercrown surface and thus allow cooling oil to remove more heat from the undercrown surface.

A piston for an internal combustion engine includes a plurality of valve pockets formed in a piston rim, the valve pockets forming fluid flow paths through the piston rim. Each of the valve pockets includes a central step standing proud of a pocket floor to limit a fluid flow area through the pocket and slow combustion gas flow from a combustion bowl toward a cylinder liner and thereby reduce displacement of an engine oil film thereon.

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 combustion chamber. The ring can continuously guides the fuel during 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.

The present disclosure relates to a piston for an internal combustion engine. The piston comprises a cover which at least partially covers a piston basehead of the piston. A heat-isolating air gap is formed between the cover and the piston basehead, which is fluidically connected to a combustion chamber and/or an upper side of the cover facing away from the heat-isolating air gap. The fluidic connection permits a fluid exchange to take place between the heat-isolating air gap and the combustion chamber. In this way, a pressure gradient can be reduced between the combustion chamber and the heat-isolating air gap. As a result, the cover is/can be kept thin without being deformed during combustion.

Operating a gaseous fuel engine includes spark-igniting gaseous hydrogen fuel and air, and propagating combustion gases of the spark-ignited mixture outwardly from a spark gap. The propagating combustion gases are impinged upon a cone surface of a piston so as to limit a flame area of the propagating combustion gases. Additional gaseous hydrogen fuel and air is ignited in the combustion cylinder by way of the propagating combustion gases to urge a piston toward a bottom-dead-center position.

The piston has a contoured combustion bowl with a radially inner shelf portion that is spaced axially away from the radially outer lip portion a first axial distance, and a swirl pocket that extends radially from the radially inner shelf portion and defines a lower axial extremity that is spaced axially away from the radially outer lip portion a second axial distance that is greater than the first axial distance. The swirl pocket defines a tangent extending in the radially outer direction, forming an acute angle with the radially outer lip portion ranging from 70 degrees to 80 degrees.