A piston crown for a piston of an internal combustion engine, the piston crown comprising an annular surface at a first end of the piston crown; and a recessed piston bowl. The piston bowl comprises: a raised floor in the center of the piston bowl; an arcuate surface located radially outward relative to the raised floor; and a lip chamfer surface extending from the arcuate surface to the annular surface. A radially inmost portion of the lip chamfer surface is radially inside the outermost portion of the arcuate surface. The radial distance between the center axis and the innermost edge of the annular surface is between 2.3 and 3.2 time the bowl height. The acute angle between a line extending in the radial direction and a line tangent to the arcuate surface closest to the first end of the piston crown is between 40 and 80 degrees.

An insert device includes a body having an upper body portion configured to couple with a cylinder head of an engine cylinder and a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder. The body includes an interior surface extending around a central volume positioned to receive liquid fuel from a fuel injector. The body includes gas inlet channels and fuel-and-gas mixture outlet channels. The gas inlet channels direct gas into the central volume where the gas mixes with the liquid fuel to form the fuel-and-gas mixture. The fuel-and-gas mixture outlet channels direct the mixture into the combustion chamber. The interior surface includes concave surface portions between the inlet channels and the outlet channels along a center axis of the body that are shaped to direct the gas into the central volume toward the liquid fuel in the central volume.

A diesel engine includes at least one cylinder (1) with a piston (2) having a piston bowl (3). A fuel injector (6) is configured to direct a fuel spray towards a target area (21) on an annular wall section (22) of the piston bowl so as to make a flame (20) formed by ignition of the fuel spray hit the target area. The target area borders, via a flow separation edge (23), on a lowered flow separation area (24) on the annular wall section so as to give this annular wall section a stepped configuration. The flow separation edge and flow separation area are configured to induce the formation of a vortex-filled wake between the flame and the flow separation area on the downstream side of the flow separation edge when the flame flows from the target area, across the flow separation edge and over the flow separation area.

A diesel engine includes at least one cylinder (1) with a piston (2) having a piston bowl (3). A fuel injector (6) is configured to direct a fuel spray towards a target area (21) on an annular wall section (22) of the piston bowl so as to make a flame (20) formed by ignition of the fuel spray hit the target area. The target area borders, via a flow separation edge (23), on a lowered flow separation area (24) on the annular wall section so as to give this annular wall section a stepped configuration. The flow separation edge and flow separation area are configured to induce the formation of a vortex-filled wake between the flame and the flow separation area on the downstream side of the flow separation edge when the flame flows from the target area, across the flow separation edge and over the flow separation area.

In an opposed-piston engine, a piston has a top land. The piston top land has a non-cylindrical shape which affords more clearance with a piston bore to thrust and anti-thrust sides than to front-facing and rear facing sides.

A piston for an internal combustion engine is disclosed. The piston comprises a number of fuel directing surfaces for directing a fuel spray sprayed onto the fuel directing surface. At least one of the fuel direction surfaces is/are inclined relative to a tangential direction of the piston. The present disclosure further relates to an engine comprising a piston and a vehicle comprising an internal combustion engine.

This piston for a diesel engine includes: a bottom portion that has a deepest combustion chamber bottom in the combustion chamber; a circumferential protrusion that is provided around an entire circumference of a circumferential wall between the bottom portion and a top surface of the piston and protrudes toward an intersection (P0) of a center line of the piston and the top surface in a cross-sectional view that includes the center line; an inclination portion that inclines closer to the top surface toward an outer side in a radial direction from the circumferential protrusion; and a rising portion that rises from the inclination portion toward the top surface.

An opposed-piston engine according to an embodiment is a first fuel injection device configured to inject fuel from a circumferential wall surface of at least one cylinder into the cylinder, and a second fuel injection device disposed to be displaced in a circumferential direction so as to be opposite to the first fuel injection device across an axial center of the cylinder. Each of the first fuel injection device and the second fuel injection device includes a plurality of injection holes having different injection directions, in a cross-section orthogonal to the axial direction. A direction directed by a first downstream injection hole is configured to pass through a second injection region, and a direction directed by a second downstream injection hole is configured to pass through a first injection region.

An alignment device for a ducted fuel injection system comprising a mounting block removably attachable to a duct of the ducted fuel injection system. The mounting block can include a passageway extending therethrough. The passageway can align with the duct when the mounting block is attached to the duct. The alignment device further comprises an imaging device configured to capture an image viewing through the duct toward an outlet of a fuel injector. A portion of the imaging device can extend in the passageway. The alignment device additionally comprises a centering structure configured to align a portion of the imaging device with a central axis of the duct. The image captured by the imaging device can be configured for use aligning a position of an outlet of a fuel injector with respect to a position of the duct.

A combustion system includes a cylinder having a main chamber and a fuel injector positioned to inject fuel into the main chamber. A cylinder head is disposed at a top of the cylinder and forms an upper end of the main chamber. A prechamber adapter has a prechamber volume and a nozzle with a plurality of orifices for communication between the prechamber volume and an external environment. The prechamber adapter is threaded into a bore in the cylinder head and positioned to expose the nozzle to the main chamber. A spark plug is positioned within the prechamber adapter with a spark emitting end exposed to the prechamber volume. A piston movably disposed within the cylinder has a piston head forming a lower end of the main chamber. The piston head has a dome shape and a bowl formed in a top center of the dome shape.