Combustion chamber structure for a motor and internal combustion engine

It is given a combustion chamber structure for an engine. The combustion chamber structure includes a piston which is formed in a central part of its upper surface with a gedellten downward recess, and a fuel injector which is arranged above the piston and in an extension line of a longitudinal axis of the Kolbe, wherein the fuel injector includes an injection timing of the fuel in changing a compression stroke corresponding to an operating state of the engine. A fuel injection angle of the fuel injection device is designed so that it satisfies a condition according to which the fuel is injected into the cavity, and a condition in which a fuel jet Auftreffdistanz that of a fuel injection position of the fuel injector to a point of the recess, on the fuel impinges, is defined, is longer than a Aufbrechstrecke, which is defined from the fuel injection position of the fuel injector to a position at which enters the first break-up of the fuel.