Closure for a refueling tank of a motor vehicle

The filler cap (11), for a vehicle fuel tank, fits into the opening of the filling pipe neck (12) with liquid/gas sealing. The upper part of the cap lies on the opening rim (22), with a ring sealing surface and a flat packing (21). The plug section (17), which projects axially from the cap, extends axially into the filling pipe. The insertion plug (17) has a laying unit (20), of equidistant hairpin springs (23), which is moved to and fro against a counter profile or an undercut at the filling pipe neck (12). The insertion plug (17) is a housing to take a push rod (28) with axial movement.