Abstract: The present disclosure is intended to provide an internal combustion engine that can inhibit fuel from adhering to a piston and can reduce generation of soot. An internal combustion engine includes a piston, a cylinder accommodating the piston, and an injector including a nozzle that has a plurality of nozzle holes configured to inject fuel into the cylinder from above the cylinder. Among the plurality of nozzle holes, a sixth nozzle hole an axial direction of which is the most deflected toward the piston has a nozzle hole diameter larger than nozzle hole diameters of the other nozzle holes, and the nozzle hole diameter of the sixth nozzle hole corresponds to at least 20% of the total of the nozzle hole diameters of the other nozzle holes.

Abstract: An internal combustion engine includes: a piston guided by a cylinder to reciprocate along a cylinder axis and forming a combustion chamber with a crown surface facing a cylinder head; and a fuel injection valve having an injection port facing the combustion chamber and injecting fuel to a forward tumble flow in the combustion chamber. A ridge formed on the crown surface rises toward a ceiling surface side relative to a reference plane, orthogonal to the cylinder axis and including an outer peripheral edge of the crown surface, and has a ridge line formed by a curved surface to surround a recessed part. The recessed part is recessed toward a center of the crown surface in a direction orthogonal to a virtual plane including the cylinder axis and parallel to a rotation axis of a crankshaft, and is recessed toward the center in an axial direction of the crankshaft.

Abstract: The present disclosure is intended to provide an internal combustion engine that can inhibit fuel from adhering to a piston and can reduce generation of soot. An internal combustion engine includes a piston, a cylinder accommodating the piston, and an injector including a nozzle that has a plurality of nozzle holes configured to inject fuel into the cylinder from above the cylinder. Among the plurality of nozzle holes, a sixth nozzle hole an axial direction of which is the most deflected toward the piston has a nozzle hole diameter larger than nozzle hole diameters of the other nozzle holes, and the nozzle hole diameter of the sixth nozzle hole corresponds to at least 20% of the total of the nozzle hole diameters of the other nozzle holes.

Abstract: An internal combustion engine includes: a piston guided by a cylinder to reciprocate along a cylinder axis and forming a combustion chamber with a crown surface facing a cylinder head; and a fuel injection valve having an injection port facing the combustion chamber and injecting fuel to a forward tumble flow in the combustion chamber. A ridge formed on the crown surface rises toward a ceiling surface side relative to a reference plane, orthogonal to the cylinder axis and including an outer peripheral edge of the crown surface, and has a ridge line formed by a curved surface to surround a recessed part. The recessed part is recessed toward a center of the crown surface in a direction orthogonal to a virtual plane including the cylinder axis and parallel to a rotation axis of a crankshaft, and is recessed toward the center in an axial direction of the crankshaft.