Fuel tank filling inlet port device

A fuel filling inlet port device for a fuel tank in a motor vehicle, comprising a wall defining therein a first bore communicating with the outside atmosphere and having a cross sectional area larger than a first predetermined value, a second bore communicating with a fuel tank of a motor vehicle and having a cross sectional area smaller than said first predetermined value and larger than a second predetermined value, a third bore located between said first and second bores and tapered off from said first bore toward said second bore, and a recess communicating with said first, second and third bores and, when a nozzle, of a first fuel feeding gun, having a cross sectional area of said first predetermined value is inserted into said third bore through said first bore to feed fuel to said fuel tank, said recess forms a path of fluid flow from said nozzle to a hole in the side of said nozzle connected to a shut off mechanism of said fuel feeding gun, said recess having one end adjacent said second bore and the other end remoter from said fuel tank than said one end, fuel from said nozzle striking against said one end and being then diverted thereby toward said other end, said fuel diverted by said one end striking against said other end and being then diverted thereby to said hole in said nozzle.