An object of the invention is to reduce the amount of smoke generated and to improve the stability of diesel combustion in cases where an EGR apparatus is used in an internal combustion engine that performs diesel combustion using fuel having a relatively high self-ignition temperature. A control apparatus performs first injection at a first injection time during the compression stroke, causes spray guide combustion to occur, and starts to perform second injection at such a second injection time that causes combustion of injected fuel to be started by flame generated by the spray guide combustion, thereby causing self-ignition and diffusion combustion of fuel to occur. The apparatus changes the ratio of the first injected fuel quantity to the total fuel injection quantity and the ratio of the second injected fuel quantity to the total fuel injection quantity for the same total fuel injection quantity in one combustion cycle, based on the EGR rate in the intake air.

An engine includes: a piston including a cavity; a cylinder head configured so as to form a combustion chamber having a pent roof shape; a fuel injection valve configured to inject fuel from a second half of a compression stroke until a first half of an expansion stroke; and a spark plug arranged at a position corresponding to an upper side of the cavity. Injection openings which are arranged in a circumferential direction surrounding a longitudinal axis of the valve and through each of which the fuel is injected in a direction inclined relative to the longitudinal axis by a predetermined angle is formed such that when a height of a ceiling of the combustion chamber at a position corresponding to an edge end portion of the cavity in an injection direction of the injection opening is large, the injection angle of the injection opening is large.

When it is determined that the initial combustion is unstable, the engine speed is forcibly increased. When the engine speed is forcibly increased, fluidity in the cylinder increases. When the fluidity in the cylinder rises, homogeneity of the homogeneous air-fuel mixture is improved. Therefore, it is possible to enlarge the flame kernel. When the flame kernel is enlarged, the initial flame resulting from the flame kernel is also enlarged. Then, the initial flame becomes easy to involve the closest fuel spray thereby the initial combustion can be stabilized.

An engine includes: a piston including a cavity; a cylinder head configured to form a combustion chamber having a pent roof shape; a fuel injection valve configured to inject fuel from a second half of a compression stroke until a first half of an expansion stroke; and a spark plug arranged at a position corresponding to an upper side of the cavity. Injection openings are arranged in a circumferential direction surrounding a longitudinal axis of the valve. The combustion chamber at a compression top dead center is divided into a plurality of fuel injection regions, located in respective injection directions of the injection openings, by vertical surfaces extending radially from the longitudinal axis through a middle between adjacent injection openings. When a volume of the fuel injection region located in the injection direction of the injection opening is large, an opening area of the injection opening is large.

A combustion control device for a compression autoignition engine includes an engine, a state quantity setting device, a spark plug, a controller, and a sensor. The spark plug receives a control signal from the controller and ignites air-fuel mixture at predetermined ignition timing such that the ignited air-fuel mixture is combusted by flame propagation and then unburned air-fuel mixture in a combustion chamber is combusted by autoignition. The controller outputs a control signal to an injector such that, in a compression stroke, fuel is injected at specific timing at which a line obtained by extending an axis of each hole of the injector overlaps with a specific portion including an opening edge of a cavity in an upper surface of a piston.

A control device for an engine is provided, which includes a fuel injector attached to the engine, a spark plug disposed to be oriented into a combustion chamber, a swirl control valve provided in an intake passage, and a controller connected to the fuel injector, the spark plug, and the swirl control valve and configured to control the fuel injector, the spark plug, and the swirl control valve. The swirl control valve closes in a given operating state of the engine. The fuel injector injects fuel after the swirl control valve is closed, between intake stroke and an intermediate stage of compression stroke. The fuel injector injects the fuel after the first fuel injection. The spark plug performs the ignition after the second fuel injection so that the mixture gas starts combustion by flame propagation and then unburned mixture gas self-ignites.

A control device of an engine including a cylinder, a piston, a cylinder head, and a combustion chamber, is provided. The device includes intake and exhaust ports, a swirl control valve, a fuel injection valve attached to the cylinder head to be oriented into the combustion chamber and having first and second nozzle ports, and a control unit. The control unit includes a processor configured to execute a swirl opening controlling module to control the swirl control valve to have a given opening at which a swirl ratio inside the combustion chamber becomes 2 or above, and a fuel injection timing controlling module to control the fuel injection valve to inject fuel at a given timing at which the swirl ratio becomes 2 or above and a swirl flow from a lower portion to a higher portion of the combustion chamber in a side view occurs.

In order to achieve stable combustion in an internal combustion engine, the engine includes a fuel injection valve having a first nozzle hole and a second nozzle hole, and an spark plug disposed at a position through which the swirling flow flows, and which is at the downstream side of the flow of the swirling flow from an extension line of the first nozzle hole and at the upstream side of the flow of the swirling flow from an extension line of the second nozzle hole, for igniting a spray of fuel injected from the fuel injection valve, wherein the first nozzle hole and the second nozzle hole are formed in such a manner that the shortest distance from the extension line of the first nozzle hole to the spark plug becomes longer than the shortest distance from the extension line of the second nozzle hole to the spark plug.

An object of the present invention is to provide a fuel injection device in which fuel sprays hardly adhere to an intake valve, a wall surface in an engine cylinder, or a piston.

In a fuel injection device including a valve body 114 and a seat surface 601 to perform injection and sealing of fuel cooperatively and a plurality of injection holes 501 and 502 of which inlet opening surfaces are formed on the seat surface 601, a first injection hole 501 and a second injection hole 501 and 502 arranged closest to the first injection hole 501, which configure the plurality of injection holes 501 and 502, are configured such that the first injection hole 501 is larger than the second injection hole 502 in an injection hole angle to be an angle formed by a normal direction 601a of the seat surface 601 and a center axis 119a of the injection hole (1>2) and the second injection hole 502 is larger than the first injection hole 501 in an area of a cross-section perpendicular to the center axis 119a of the injection hole (injection hole diameter Da2>injection hole diameter Da1).

This invention discloses a combustion method, which is for an internal combustion engine, which utilizes variable spray patterns matched with a combustion chamber composing of multiple connected spaces based on injection timings and engine loads. This invention provides means to control propagation paths of combustion reaction radicals and control pressure rise rate, and also provides means to promote stratification of premixed charges. An internal combustion engine utilizing the disclosed combustion methods is also disclosed.