Disclosed are an apparatus of injecting fuel for an engine and a method thereof.

The apparatus of injecting fuel for an engine includes: a main injector positioned adjacent to an exhaust valve and injecting the fuel into a combustion chamber of the engine; and an auxiliary injector positioned adjacent to an intake valve and injecting the fuel into the combustion chamber of the engine later than injection time of the main injector, wherein the fuel injected from the main injector and the fuel injected from the auxiliary injector are injected into the combustion chamber in a tumble direction.

Disclosed are an apparatus of injecting fuel for an engine and a method thereof.

The apparatus of injecting fuel for an engine includes: a main injector positioned adjacent to an exhaust valve and injecting the fuel into a combustion chamber of the engine; and an auxiliary injector positioned adjacent to an intake valve and injecting the fuel into the combustion chamber of the engine later than injection time of the main injector, wherein the fuel injected from the main injector and the fuel injected from the auxiliary injector are injected into the combustion chamber in a tumble direction.

To accurately evaluate combustion stability in consideration of the effect of the trend even at the time of the transient operation. The present invention is configured to have a combustion energy calculation unit that calculates a combustion energy W_t of one combustion cycle in an internal combustion engine, a trend calculation unit that calculates a trend Tr of change in the combustion energy W_t calculated by the combustion energy calculation unit in a plurality of the combustion cycles, and a combustion stability judgment unit that judges combustion stability based on the combustion energy W_t in the plurality of combustion cycles and the trend Tr of change calculated by the trend calculation unit.

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.

An internal combustion engine, comprising a super-charging, which is designed to compress the charge air into the charge air pipe, with overpressure up to 2.8 BAR, a throttle valve, which operation is to provide a sufficient amount of charge air into the main combustion chamber, while together throttling an overpressure of the charge air from the charge air pipe to achieve a pressure reduction and thus a temperature reduction of the charge air in the intake port up to −20° C. (−4° F.), a cylinder head, which is equipped with a swirl chamber, per main combustion chamber, the size of which is 8% to 15% of the compression volume, whereby the formation of the fuel/air mixture occurs only in this swirl chamber, whereby in combination with the subcooling of the charge air in the intake port, reduces fuel consumption.

An internal combustion engine, comprising a super-charging, which is designed to compress the charge air into the charge air pipe, with overpressure up to 2.8 BAR, a throttle valve, which operation is to provide a sufficient amount of charge air into the main combustion chamber, while together throttling an overpressure of the charge air from the charge air pipe to achieve a pressure reduction and thus a temperature reduction of the charge air in the intake port up to −20° C. (−4° F.), a cylinder head, which is equipped with a swirl chamber, per main combustion chamber, the size of which is 8% to 15% of the compression volume, whereby the formation of the fuel/air mixture occurs only in this swirl chamber, whereby in combination with the subcooling of the charge air in the intake port, reduces fuel consumption.

An engine system comprising an internal combustion engine and a turbocharger, where a diameter of the at least one intake valve is greater than a diameter of the at least one exhaust valve, the salient angle of the piston bowl is at least 10 degrees, the ratio between the piston bowl opening diameter and the piston bowl depth is approximately 0.5 to 2.0, the intake valve opens before top dead center on an exhaust stroke of the internal combustion engine and closes before bottom dead center of an intake stroke of the internal combustion engine, and the turbocharger has a combined efficiency of more than 50%.

A structure of a combustion chamber for an engine includes a crown surface of a piston, a combustion chamber ceiling surface, an injector and an ignition plug provided on the combustion chamber ceiling surface, and an intake opening and an exhaust opening opened in the combustion chamber ceiling surface. A side where the intake opening is opened is defined as an intake port side, and a side where the exhaust opening is opened is defined as an exhaust port side. An ignition portion of the ignition plug is disposed on the intake port side. The ignition plug is ignited at a timing after the piston passes a compression top dead center. The injector is disposed on the center portion, and is configured to inject fuel toward the exhaust port side. A cavity is provided on the crown surface. A reverse squish flow generation portion is provided in the combustion chamber.

A fuel injection control device for an engine is provided. A swirl generator generates a swirl flow inside a combustion chamber. A fuel injector with multiple nozzle holes injects fuel into the combustion chamber, and forms a lean mixture gas inside the combustion chamber. An spark plug ignites the lean mixture gas to cause a portion of the mixture gas to start combustion accompanied by flame propagation, and then combusts by self-ignition. The fuel injector has first and second nozzle holes, and a first atomized fuel spray injected from the first nozzle hole and a second atomized fuel spray injected from the second nozzle hole separate from each other by the swirl flow. The fuel injector sequentially performs a first injection and a second injection in an intake stroke. The controller makes an injection amount of the second injection greater than that of the first injection.

A structure of a combustion chamber for an engine includes a crown surface of a piston, a combustion chamber ceiling surface formed on a cylinder head, an injector and an ignition plug provided on the combustion chamber ceiling surface, and an intake opening and an exhaust opening opened in the combustion chamber ceiling surface. A side where the intake opening is opened is defined as an intake port side, and a side where the exhaust opening is opened is defined as an exhaust port side, with respect to a position, as a reference, where an ignition portion of the ignition plug is disposed in a plan view from one side in a cylinder axis direction, the injector is configured to inject fuel toward the exhaust port side, and a reverse squish flow generation portion, which draws an air-fuel mixture toward the intake port side, is provided in the combustion chamber.