The present invention relates to a gas intake pipe (2) for a cylinder of a thermal engine. The pipe comprises means for diverting the gas so as to generate a tumble type aerodynamic motion of the gas within the cylinder. The diversion means comprise at least a “ramp” shape (6) on the lower profile (12) of the pipe and a concave zone on the upper profile (10) of intake pipe (2).

The present invention relates to a gas intake pipe (2) for a cylinder of a thermal engine. The pipe comprises means for diverting the gas so as to generate a tumble type aerodynamic motion of the gas within the cylinder. The diversion means comprise at least a “ramp” shape (6) on the lower profile (12) of the pipe and a concave zone on the upper profile (10) of intake pipe (2).

The present invention relates to a gas intake device (1) for a cylinder of an internal-combustion engine. Gas intake device (1) comprises an intake pipe (2), an intake valve (3), a calibration part (4) for intake valve (3), and means for generating an aerodynamic motion of the gas in the cylinder about an axis substantially perpendicular to the axis of said cylinder. Furthermore, intersection (7) between intake pipe (2) and calibration part (4) occurs in a line nonparallel to the plane of fire face (FF).

A compression ignited combustion engine has at least one cylinder and first and second gas intake ports in a cylinder head restricting a combustion chamber. One gas intake passage leads to the two ports and is widened in a Y-shaped end influencing gas entering each port into a tangential flow in opposite direction with respect to the flow into the other port. The first intake port is designed to allow gas entering this port to continue said tangential flow so as to enter the combustion chamber in a swirl in a first rotation direction, whereas the second intake port is designed to guide gas entering this port to also enter the combustion chamber in a swirl in said first rotation direction.

A compression ignited combustion engine has at least one cylinder and first and second gas intake ports in a cylinder head restricting a combustion chamber. One gas intake passage leads to the two ports and is widened in a Y-shaped end influencing gas entering each port into a tangential flow in opposite direction with respect to the flow into the other port. The first intake port is designed to allow gas entering this port to continue said tangential flow so as to enter the combustion chamber in a swirl in a first rotation direction, whereas the second intake port is designed to guide gas entering this port to also enter the combustion chamber in a swirl in said first rotation direction.

The present invention relates to a gas intake device (1) for a cylinder of an internal-combustion engine. Gas intake device (1) comprises an intake pipe (2), an intake valve (3), a calibration part (4) for intake valve (3), and means for generating an aerodynamic motion of the gas in the cylinder about an axis substantially perpendicular to the axis of said cylinder. Furthermore, intersection (7) between intake pipe (2) and calibration part (4) occurs in a line nonparallel to the plane of fire face (FF).

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 retarded when an in-cylinder pressure specified by an in-cylinder pressure specification section is high than when the in-cylinder pressure is low.

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 retarded when an in-cylinder pressure specified by an in-cylinder pressure specification section is high than when the in-cylinder pressure is low.

An intake device of an internal combustion engine includes a partition, a control valve, and a third passage. The partition divides an interior of an intake pipe that couples with a combustion chamber into a first passage and a second passage. The control valve is capable of opening and closing the first passage. The third passage opens at or near a coupling site between the partition and the intake pipe on an inner face of the second passage. The third passage is configured to be capable of sucking in at least a part of a boundary layer produced at or near the coupling site by a vapor flowing through the second passage in a state in which the control valve is working in a direction of closing the first passage.

An intake device of an internal combustion engine includes a partition, a control valve, and a third passage. The partition divides an interior of an intake pipe that couples with a combustion chamber into a first passage and a second passage. The control valve is capable of opening and closing the first passage. The third passage opens at or near a coupling site between the partition and the intake pipe on an inner face of the second passage. The third passage is configured to be capable of sucking in at least a part of a boundary layer produced at or near the coupling site by a vapor flowing through the second passage in a state in which the control valve is working in a direction of closing the first passage.