Examples are directed to a fuel injection device positioned in a cylinder liner. In one example, a cylinder includes a combustion chamber which is jointly formed by a piston crown of a piston, by a cylinder barrel which laterally delimits the combustion chamber, and by a cylinder head. The cylinder includes an injection device positioned in the cylinder barrel for direct introduction of fuel into the combustion chamber, which injection device has at least one opening which, during a course of an injection process, is configured to be activated to introduce fuel into the combustion chamber, the injection device terminating flush, at a combustion chamber side, with the cylinder barrel.

A fuel injector for an internal combustion engine. The fuel injector has a needle and a nozzle that inter-relate with each other in assembly. Relative movement between the needle and nozzle bring the fuel injector between a closed state of operation and an open state of operation amid use of the fuel injector. The nozzle has one or more passages therein through which fuel is discharged.

In a spark-ignition internal combustion engine in which a protrusion including an intake-side inclined surface and an exhaust-side inclined surface is formed on a top surface of a piston, and a cavity is formed in the protrusion at a position associated with a spark plug, the intake-side inclined surface and the exhaust-side inclined surface are formed in such a way that an angle defined by an orthogonal plane orthogonal to a center axis of a cylinder and the exhaust-side inclined surface) is smaller than an angle defined by the orthogonal plane and a valve head bottom surface of an exhaust valve, and an inclination angle difference between the exhaust-side inclined surface and the valve head bottom surface of the exhaust valve is larger than an inclination angle difference between the intake-side inclined surface and a valve head bottom surface of an intake valve by 3 degrees or larger.

Embodiments disclosed herein relate to internal combustion engines, combustion systems that include such internal combustion engines, and controls for controlling operation of the combustion engine. The internal combustion engine may include one or more mechanisms for injecting fuel, air, fuel-air mixture, or combinations thereof directly into one or more cylinders, and controls may operate or direct operation of such mechanisms.

Combustion cylinder (10) of an internal combustion engine, having a combustion chamber wall (20), which surrounds a combustion chamber (30), and a combustion chamber cover (40), which closes off the combustion chamber (30) on the upper side, wherein at least one inlet valve (50) for letting in a fluid is arranged on an inlet side (42) in the combustion chamber cover (40), and at least one outlet valve (60) for letting out a fluid is arranged on an outlet side (44) in the combustion chamber cover (40), wherein, furthermore, a prechamber spark plug (70) is arranged between the at least one inlet valve (50) and the at least one outlet valve (60) in the combustion chamber cover (40), which prechamber spark plug is arranged between the at least one inlet valve (50) and an injector (80) for injecting combustion fluid.

Among all combinations of two injection holes, in a combination in which when the injection holes are offset such that their central axes are coincident with each other in inlet openings, an inter-injection hole angle formed by the central axes is minimized, the inter-injection hole angle between the two injection holes is represented as yamin[deg], taper angles, which are formed by the respective contours of the injection hole inner walls in the cross sections along the virtual planes including the central axes of the two injection holes that allow the inter-injection hole angle to be minimized, are represented as a1 and a2[deg], and when fuel is injected from the injection holes, average pressure of the fuel in the fuel passage is represented as P[Mpa], and the injection holes are formed so as to satisfy a relationship: amina1+a2+0.5P.sup.0.6.

An engine controller controls a direct fuel-injection, spark ignition engine including a fuel injection valve configured to directly inject a fuel into a cylinder, and an ignition plug that spark-ignites a mixture in the cylinder. The engine controller is provided with an acceleration request sensor configured to detect an acceleration request of a driver, and when the acceleration request occurs and a top surface temperature of a piston in the cylinder is lower than a predetermined temperature, the engine controller retards an ignition timing so that a period of time until a flame after the ignition reaches the piston top surface is extended.

Embodiments disclosed herein relate to internal combustion engines, combustion systems that include such internal combustion engines, and controls for controlling operation of the combustion engine. The internal combustion engine may include one or more mechanisms for injecting fuel, air, fuel-air mixture, or combinations thereof directly into one or more cylinders, and controls may operate or direct operation of such mechanisms.

Among all combinations of two injection holes, in a combination in which when the injection holes are offset such that their central axes are coincident with each other in inlet openings, an inter-injection hole angle formed by the central axes is minimized, the inter-injection hole angle between the two injection holes is represented as a min[deg], taper angles, which are formed by the respective contours of the injection hole inner walls in the cross sections along the virtual planes including the central axes of the two injection holes that allow the inter-injection hole angle to be minimized, are represented as a1 and a2[deg], and when fuel is injected from the injection holes, average pressure of the fuel in the fuel passage is represented as P[Mpa], and the injection holes are formed so as to satisfy a relationship: a mina1+a2+0.5P.sup.0.6.

In an upstream portion from a valve connecting surface that is formed in an opening of an intake port to a combustion chamber, an upper wall surface of the intake port continues from an upstream side end of the valve connecting surface and extends substantially straight and diagonally with respect to a ceiling surface on the intake port side. In addition, a cross-sectional shape of the portion in the intake port in a direction perpendicular to an axial direction of the intake port is a flat shape with an axis in a transverse direction being a long axis.