Abstract: In an internal combustion engine with direct fuel injection having a cylinder, a piston and a cylinderhead defining together a combustion chamber, a fuel injector with a fuel injection nozzle is mounted in the cylinder head for delivering fuel from the fuel injection nozzle into the combustion chamber so as to form a mixture cone. A spark plug is mounted in a spark plug sleeve disposed in the cylinder head and projects into the combustion chamber beyond the spark plug electrodes and into the mixture cone so as to form at its front end adjacent the spark plug electrodes an open ignition chamber in which part of the rich fuel mixture of the fuel mixture cone is collected for ignition by the spark plug.

Abstract: In an internal combustion engine with direct fuel injection, which comprises a number of operating elements each including a combustion chamber delineated by an internal wall of a cylinderhead and a piston movably disposed in a cylinder, an injector mounted in the cylinderhead has a fuel injection nozzle which injects fuel into the combustion chamber in a cone-like pattern wherein an ignitable fuel/air mixture is formed and a spark plug is mounted on the cylinderhead within a spark plug sleeve which extends into the combustion chamber and forms, adjacent the spark plug electrodes, an ignition chamber which is in communication with the interior of the cone-like fuel spray pattern so as to receive therefrom an easily ignitable relatively rich fuel mixture which, upon ignition by the spark plug, generates a flame beam igniting the fuel mixture within the cone-like spray pattern.

Abstract: A four-cycle reciprocating-piston internal combustion engine having a main combustion chamber connected by a spill port with an unflushed ignition chamber. A fuel injection nozzle and a spark plug are arranged at the ignition chamber at angles with respect to one another. Fuel supply means are also provided at the main combustion chamber for supplying a substantial majority of the fuel consumed by the engine during operation. In order to maximize the effectiveness of the ignition chamber, while minimizing the high peak pressures, the ignition chamber and spill port are constructed so as to have an extensive homogenization of the fuel proportion injected into the ignition chamber. In preferred embodiments, the ratio of the volume of the ignition chamber to the total compression volume of the engine is in the range of 0.10 to 0.30 and the ratio of the volume of the spill port to the total compression volume is in the range of 0.01 to 0.25.