A control apparatus for a compression-ignition type engine is applied to an engine capable of carrying out partial compression ignition combustion in which an air-fuel mixture is subjected to CI combustion by self-ignition. The control apparatus creates a lean A/F environment where an air-fuel ratio as a ratio between air and fuel in a cylinder exceeds 20 and is lower than 35, or a lean G/F environment where a gas air-fuel ratio as a ratio between entire gas and the fuel in the cylinder exceeds 18 and is lower than 50 and the air-fuel ratio substantially matches a stoichiometric air-fuel ratio. Prior to planned timing of the CI combustion, in the lean A/F environment or the lean G/F environment, the control apparatus causes an ignition plug to generate a spark and to generate a high-temperature portion.

In a compression-ignition engine having a two-stage cavity, the distribution ratio between fuel for an upper cavity and fuel for a lower cavity is maintained even when the operational state of the engine changes. A piston of the compression-ignition engine includes a lower cavity, an upper cavity, and a lip portion between the lower cavity and the upper cavity. A controller causes a main injection and at least one pilot injection to be executed when the engine operates in a first state and a second state in which the speed is higher than the speed in the first state. The fuel spray is distributed to the lower cavity and the upper cavity. The controller increases an injection amount per pilot injection when the engine operates in the second state than when the engine operates in the first state.

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 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.

A neat-fuel direct-injected compression ignition engine having a thermal barrier coated combustion chamber, an injection port injects fuel that satisfies a stoichiometric condition with respect to the intake air, a mechanical exhaust regenerator transfers energy from exhaust gas to intake compression stages, an exhaust O.sub.2 sensor inputs to a feedback control to deliver quantified fuel, a variable valve actuation (VVA) controls valve positions, an exhaust gas temperature sensor controls exhaust feedback by closing the exhaust valve early according to the VVA, or recirculated to the chamber with an exhaust-gas-recirculation (EGR), heat exchanger, and flow path connecting an air intake, a load command input, and a computer operates the EGR from sensors to input exhaust gas according exhaust temperature signals and changes VVA timing, the load control is by chamber exhaust gas, the computer operates a fuel injector to deliver fuel independent of exhaust gas by the O.sub.2 signals.

A piston crown for a combustion system is disclosed. The piston crown includes a piston bowl having a circumferential recess and a plurality of first recesses arranged spaced apart from each other along a circumferential direction. The circumferential recess is disposed proximate to a circumference of the piston crown. Each recess of the plurality of the first recesses extends between a center of the piston crown and the circumferential recess, and a width and a depth of each recess of the plurality of first recesses are extended along a radial direction for an entire length of each recess of the plurality of first recesses.

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 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 an injection hole 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 fuel injected from the injection hole passes. An outer circumferential surface of the passage-forming member contacts a combustion-chamber ceiling surface of the cylinder head, and the passage of the passage-forming member includes an enlarged part gradually increasing in a cross-sectional area thereof from an upstream side to a downstream side of the passage.