part which is secured in fuelproof fashion in a fuel return opening in the housing and onto which the plug part is placed in fuelproof fashion application_number US 29615202 A description in fig1 a first exemplary embodiment of a fuel injection device is identified overall by reference numeral 10 the fuel injection device 10 shown is a common rail injector it serves in an internal combustion engine to inject the fuel directly into the combustion chamber of the engine neither the engine nor the combustion chamber is shown in fig1 the injector 10 includes a housing 12 which on its lower end not shown in fig1 is secured to the cylinder head of the engine on the end of the injector 10 projecting from the cylinder head of the engine that is the end that is visible in fig1 there is a high pressure fuel connection not visible an electrical connection 14 is also provided there by way of which the injector 10 can be connected to an engine control unit not shown laterally in the upper region of the housing 12 is a fuel return connection 16 which comprises a socket part 18 and a plug part 20 the socket part 18 is inserted into a return opening 22 in the housing 12 of the injector 10 the longitudinal axis of the return opening 22 in the present exemplary embodiment extends in the radial direction that is perpendicular to the longitudinal axis of the housing 12 of the injector 10 but in an exemplary embodiment not shown there can also be an offset between the longitudinal axis of the housing and the.