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 fuel injection valve capable of forming a homogeneous air-fuel mixture in homogeneous combustion at a low engine speed and a control device thereof are provided. According to the present invention, a fluid injection valve that is configured separately from a fuel injection valve and has a function of injecting a fluid is provided and a control device of the fuel injection valve includes a control unit that performs control such that fuel is injected from the fuel injection valve and then controls the fluid injection valve such that the fluid is injected from the fluid injection valve and the fuel injected from the fuel injection valve is stirred.

An engine includes a combustion chamber, a fuel injector, a spark plug, and a piston. The combustion chamber receives air from an intake valve, which receives air from an external environment of the engine. The fuel injector includes a fuel channel, a fuel port, an air port, a needle valve, and a premixing tube. The fuel channel receives fuel from a fuel supply. The needle valve initially covers the fuel port, and actuates to fluidly connect the fuel port to the fuel channel such that the fuel port receives the fuel. The air port draws air into the fuel injector, and the premixing tube mixes the air and fuel to create a mixture. The mixture is fed into the combustion chamber along a central axis of the premixing tube such that the mixture intersects the electrode of the spark plug, which ignites the mixture to actuate the piston.

A fuel injection valve is provided for a ceiling portion of a cylinder head. A tip of an ignition electrode is arranged in the vicinity of an injection tip of the fuel injection valve. A recess is provided for the ceiling portion. A center of a cavity is shifted with respect to a bore center of the cylinder. In a vertical cross-section of the inside of a combustion chamber taken along a plane passing through the injection tip of the fuel injection valve and the tip of the ignition electrode, a distance from the injection tip to a wall surface of the cavity at a side at which the ignition electrode is provided is longer than a distance from the injection tip to a wall surface of the cavity at an opposite side.

A fuel injection valve is shifted, with respect to the bore center of a cylinder, toward one end of an engine's output shaft. A top surface of a piston has inclined surfaces, and is raised by the inclined surfaces. A cavity is formed by hollowing out portions of the inclined surfaces, and faces the injection axis of the fuel injection valve. In a vertical cross section taken along the plane passing through a particular location in an intake other-side region of a combustion chamber and the location of the fuel injection valve, the distance from an injection tip of the fuel injection valve to the wall surface of the cavity at the particular location is longer than that from the injection tip to the wall surface at a diametrically opposed location to the particular location.

When it is determined that the combustion state during the catalyst warm-up control is unstable, an additional ignition is performed on the TDC side relative to the discharge period CP. In a first countermeasure example, an additional ignition period CP.sub.2 is provided on the TDC side relative to the ignition period CP.sub.1 at the normal time while performing normal ignition and injection. A second countermeasure example is carried out when it is determined that the combustion state is still unstable despite the first countermeasure example. In the second countermeasure example, an additional ignition period CP.sub.3 which is a longer period than the additional ignition period CP.sub.2 is provided instead of the additional ignition period CP.sub.2.

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: ignition plugs which ignite an air-fuel mixture in combustion chambers; a power transmission member which transfers rotary motion of a crankshaft to a valve operation control mechanism for air intake and exhaust valves; and a transmission member housing space having the power transmission member disposed therein. The ignition plugs include first and second ignition plugs for each of the combustion chambers. The first ignition plug is located on a cylinder axis, and the second plug is arranged offset relative to the first ignition plug so as to be away from the transmission member housing space in a widthwise direction of the engine along which the crankshaft extends.

The present disclosure relates to an internal combustion engine, comprising: at least one cylinder; two charge-exchange ports per cylinder, a first charge-exchange port being an inlet port, and a second charge-exchange port being an outlet port; and one spark plug and one prechamber spark plug per each cylinder.

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 in a period 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.