Abstract: An air-compressing, self-ignition or spark-ignition, four-stroke internal combustion engine having direct fuel injection, turbo-charging, and load-dependent exhaust gas recirculation which is effected, at least in certain operating ranges, by intervention in the gas change system. In order to prevent weakening of the air swirl energy (charge swirl energy) by exhaust gas recirculation at low load in such an internal combustion engine, on the one hand, and, on the other hand, to obtain assisted cylinder scavenging at higher loads, the intake valve is briefly opened during the exhaust stroke. The opening of the intake valve occurs no earlier than 30 degress crank angle after gas-change bottom dead center, and the highest lift is between 15 and 30% of the maximun intake valve lift; and, at the latest, when the exhaust valve closes (shortly before gas change top dead center).

Abstract: A direct-injection internal combustion engine has a rotationally symmetric combustion chamber which is located in the crown of a piston. Air for combustion is admitted into the combustion chamber in such a manner as to circulate about the axis of the latter. Fuel is injected into the combustion chamber through a discharge passage as a function of the engine load and speed. Within the upper range of engine load and speed, the fuel is injected as a concentrated jet and virtually all of the fuel is deposited upon the wall of the combustion chamber. The fuel evaporates from the wall and then mixes with the circulating air. In the lower range of engine load and speed, as well as during idling, the fuel is injected in the form of a finely atomized jet and mixes with the circulating air directly. The effective cross-sectional area of the fuel discharge passage in the lower range of engine load and speed is maintained between about 3 and 15% of the effective cross-sectional area at maximum output.

Abstract: An air-compressing, direct-injection internal combustion engine formed with a combustion chamber in the shape of a solid of revolution in the piston crown into which fuel is injected via only one jet through an injection nozzle arranged obliquely in the cylinder head, in the direction of the rotating air for combustion. The working of the internal combustion engine is proposed to be improved in such a way that fuel deflection liable to occur in all operating ranges, mainly at the start and at the end of injection due to the rotating air flow and, respectively, when the gas is flowing out of the combustion chamber after the top dead center position, is prevented from affecting the working of the engine and from producing erosion on the piston crown and/or cylinder head.

Abstract: An arrangement for air-compressing, direct-injection internal combustion engine having fuel ignition, at least one piston with a combustion chamber having a constricted throat and a pertaining cylinder having a pertaining cylinder head is disclosed. In this arrangement, the fuel injector and the combustion chamber of the piston are in communication with one another, the point of intersection of the longitudinal central axis of the fuel stream with the plane of the pertaining cylinder head which limits the upward movement of the piston is positioned within an imaginary circle having a diameter which is at most 1.1 times the greatest diameter of the combustion chamber, and the fuel injector is adapted to be located from the combustion chamber at a distance of up to about 30% of the greatest diameter of the combustion chamber.