Fuel injection nozzle for self-igniting internal combustion engines

A fuel injection nozzle for self-igniting internal combustion engines, having a nozzle body (10) in which a conical valve seat face (14) is formed on the injection end of a bore (12), from which face the injection ports (20) extend, and having a valve needle (30), opening counter to a closing force counter to the flow direction of the fuel, which needle is guided displaceably in the entrance region of the bore (12) remote from the injection end and which on its side toward the valve seat face (14) has a closing cone (31), which cooperates with the valve seat face (14), characterized in that the injection port cross section, beginning at the valve seat face (14), decreases continuously as far as a smallest cross section (25), embodied at precisely one point, and from there on widens again continuously, so that a convergent part (21) of the injection port (20) and a divergent part (22) of the injection port (20) are separated from one another by the smallest cross section (25).