Provided is an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Ignition timing of the preceding ignition is set to be more advanced when an in-cylinder temperature specified by an in-cylinder temperature specification section is high than when the in-cylinder temperature is low.

The invention is provided with an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Ignition timing of the preceding ignition is set to be more retarded when fuel concentration specified by a fuel concentration specification section is low than when the fuel concentration is high.

An engine control apparatus includes an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate the SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes the injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Energy of the preceding ignition is set to be higher when an engine speed is high than when the engine speed is low.

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 inclination angle of the exhaust-side inclined surface is smaller than an inclination angle of the intake-side inclined surface, and a difference in inclination angle between the intake-side inclined surface and the exhaust-side inclined surface is 4 degrees or larger.

An engine includes a cylinder head, an intake manifold, and a partition wall. The cylinder head includes an intake port communicating with a combustion chamber. The intake manifold is fixed to the cylinder head and includes an intake passage communicating with the intake port. The partition wall that separates at least part of the intake port into a first channel and a second channel. The partition wall includes a partition wall member extending from the intake port to the intake passage and fixed to an inner wall of the intake port and an inner wall of the intake passage.

An auxiliary chamber (51) having a spark plug (54) and an auxiliary fuel injector is formed at the central part of the top surface of the main combustion chamber (2). When making an air-fuel mixture in the auxiliary chamber (51) burn by the spark plug (54), an air-fuel mixture in the main combustion chamber (2) is made to burn by jet flames ejected from the communicating holes (52). The injection ports of the auxiliary fuel injector (53) are oriented toward a tumble flow inflow peripheral region (R) which is located on the peripheral part of the end portion of the auxiliary chamber (51) at a place located on a side where the tumble flow W flows in from the communicating holes (52). When the tumble flow (W) is made to be generated in the main combustion chamber (2) by the tumble flow control valve (48), auxiliary fuel (QF) is injected from the auxiliary fuel injector (53) toward the tumble flow inflow peripheral region (R) of the auxiliary chamber (51).

Provided is a thermally insulated insert member and an engine having the thermally insulated insert member. Thermally insulated insert member is disposed in an intake port of a cylinder head of the engine. The thermally insulated insert member includes a guide member that guides a flow of intake air flowing in t he intake port; and a thermally insulative support member with a shape that can be fitted within the intake port. The guide member is formed of a metal and is supported in the intake port via the thermally insulative support member.

Provided is a thermally insulated insert member and an engine having the thermally insulated insert member. Thermally insulated insert member is disposed in an intake port of a cylinder head of the engine. The thermally insulated insert member includes a guide member that guides a flow of intake air flowing in t he intake port; and a thermally insulative support member with a shape that can be fitted within the intake port. The guide member is formed of a metal and is supported in the intake port via the thermally insulative support member.

An intake device of an internal combustion engine includes a partition, a gap, and a projecting part. The partition divides an interior of an intake pipe into a first passage and a second passage. The gap exists at a boundary between an inner face of the intake pipe and the partition or in the partition, and couples the first passage and the second passage. The projecting part is disposed near the gap on a face of the partition or the inner face of the intake pipe that forms an inner face of the first passage, or on a face of the partition or the inner face of the intake pipe that forms an inner face of the second passage.

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.