Fuelling system for fuelling of a vehicle tank

A filling neck to feed fuel into a motor vehicle tank using a filling nozzle, exhibiting the following features: a slotted drive ring comprising an insertion portion conically tapering toward the vehicle fuel tank, the cross-sectional constriction being less than the filling nozzle's cross-section; the drive ring, facing the fuel tank comprises, on at least one side of said gap, a locking segment; the drive ring is configured in floating manner in a cup-shaped housing portion of the filling neck, the outside diameter of said ring being less than the inside diameter of the cup-shaped housing portion; a sealing element is associated with the distal end of the drive ring, blocking access to the tank in its closed position; the drive ring's locking segment engages and keeps the sealing element in the locked position, and moves into the open position when said drive ring is expanded by the filling nozzle.

RELATED APPLICATIONS

The present application is National Phase of International Application Number PCT/IB2009/053571, filed Aug. 12, 2009, and claims priority from, German Application Number 10 2008 039 311.8, filed Aug. 22, 2008.

The present invention relates to a filling neck, to feed fuel to a motor vehicle tank, as claimed in claim1.

The diameters of gasoline fuel nozzles are usually smaller than those of diesel fuel nozzles. However diesel engines still can be erroneously fed with gasoline for lack of special precautions. The German patent document DE 10 2004 001 994 B3 discloses a fuel filling neck configuring a floating drive ring in a housing portion of the filling nozzle. This drive ring is fitted with a gap running axially and its outside diameter, in said ring's relaxed state, is less than the inside diameter of the said housing portion which is cup-shaped. At its end facing the tank, hereafter the distal [flow] end, the drive ring comprises a sealing flap which is spring-biased to block access to the tank. Said sealing flap shall be unlocked when the drive ring is radially expanded due to the fuel nozzle being forced inward. The filling nozzle makes it possible to pry open the inner sealing flap against the spring force.

This known filling neck does prevent erroneous fuel filling because only fuel nozzles of a predetermined diameter shall expand the drive ring whereas fuel nozzles of lesser diameters may pass through it unhampered and thereby come to rest against the sealed flap. If the fuel nozzle is opened nevertheless, the flap inside it shall close once because the fuel flow shall be dammed up.

This known design is especially suitable for so-called capless filling systems. The filling pipe in such designs is no longer sealed by a cap. Sealing is solely implemented by the internal sealing flap at the filling pipe.

The objective of the present invention is to improve a filling neck of the cited kind in that it may selectively be operated with or without said drive ring.

This problem is solved by the features of claim1.

In the present invention, an affixation ring is detachable mounted on the drive ring's side opposite the sealing element in the filling neck. Said affixation ring affixes the drive ring oppositely the direction of insertion of the fuel nozzle.

Absent any further design features, the filling neck of the present invention allows inserting the drive ring from the outside into said neck. At its distal side, the said drive ring comes to rest against a stop and, at its opposite side, hereafter the proximal [flow] side, it shall be affixed by the affixation ring. Independently of such design features, the drive ring may be supported in more or less pronounced floating manner in the cup-shaped housing portion of the filling neck. The affixation ring is detached easily and thereby allows removing said drive ring from the filling neck for servicing. Accordingly the filling neck per se need not be disassembled. However, in very advantageous manner, the filling neck of the present invention also may be operated in the absence of a drive ring when the particular motor vehicle might be designed without protection against mis-fueling. In this latter case only the affixation ring is inserted and clamped because matching by its inside contour the desired inner contour of a filling neck that is configured for the particular fuel to be used.

The present invention also applies to cap-fitted tank filling necks.

A number of ways may be used to mount the affixation ring in simple manner within the filling neck. In an especially preferred embodiment mode of the present invention, the affixation ring is mounted by means of a bayonet lock on the filling neck. This feature eliminates the need for additional affixation ring elements. In some circumstances, said ring may even be inserted manually. To assure simple disengagement, one embodiment mode of the present invention the affixation ring is fitted at its end facing the insertion aperture with tool access means, if desired holes, allowing rotating said ring. In this manner the affixation ring may be disengaged from the bayonet lock by mere rotation.

In one embodiment mode of the present invention, the affixation ring is fitted at its outside with at least one radial boss to attain bayonet locking, said protrusion engaging a hook-like slot in the inside wall of the filling neck. Said slot may comprise an axial insertion segment and an adjoining circumferential element. Preferably this circumferential element is fitted near its end with a narrow cross-section requiring pressing the protrusion through it in order to move said boss as far as the end of the circumferential element. In this manner the affixation ring is held in its position and will not disengage by itself.

The drive ring also may be fitted in another embodiment mode of the present invention with means allowing removing it in simple manner from the filling neck for purposes of servicing. Also the drive ring may have to be removed when fuel nozzles of lesser diameters are used, as in several East European and Asian countries.

FIG. 1shows a casing10of a filling neck comprising an insertion end12.FIG. 3shows the configuration of the casing10in a fuel filling pipe14.FIG. 3shows the configuration of the casing10within a filling pipe14. The filling pipe14runs to an omitted motor vehicle tank and is kept in place in appropriate manner. At its free end said filling pipe is fitted with an inwardly pointing bead16operating in concert with resilient or spring tabs18on the outside of the plastic casing10to axially affix this casing. On its inside, the casing10is fitted with circumferentially spaced apart resilient or spring tabs20for a purpose elucidated below.

FIG. 1also shows a drive ring22comprising a circumferential series of segments24in an insertion portion, said segments tapering in the direction of insertion. This design subtends a circular, constricted cross-section26aof which the diameter is smaller than that of a fuel nozzle26that shall be admissible to feed fuel to the vehicle equipped with the filling neck. The drive ring22comprises a slot28running parallel to ring's center axis. A sealing flap30pivotably rests at the distal end. It is kept in the closed position by an omitted spring. In that closed position and as indicated at the bottom ofFIG. 4, this flap rests against the distal ends of the segments24. At its distal end, the drive ring is fitted on both sides of the slot22with hook elements36,38enclosing a radial extension40of the flap30for the purpose of locking this flap30in its closed position. This closed position is shown at the bottom ofFIG. 4wherein the flap30is locked by the hook elements36,38. The drive ring22is externally cylindrical and is externally fitted with a spring42radially biasing it in a manner that it shall assume the bottom position shown inFIG. 4. When, due to fuel nozzle insertion, the drive ring22is expanded, the hook elements36,38move apart as indicated at the top left ofFIG. 4. In this manner a fuel nozzle is able to open the flap30as shown at the top right ofFIG. 4. However such a drive ring is already known.

FIG. 3shows the configuration of the drive ring22within a cup-shaped housing portion46. The drive ring is secured in place relative to the tank by further, omitted stops. However, within limits, the drive ring22is able to move radially, such radial displacements being damped by the spring tabs20. The drive ring is secured in place relative to the filling aperture12by an affixation ring48which is also shown inFIG. 1. The contour of the inside of the affixation ring48is approximately oval, the cross-section being gradually constricting. Such a contour facilitates inserting the fuel nozzle26(FIG. 3). The affixation ring48is cross-sectionally circular and is fitted at its outside with two diametrically opposite small bosses50of which only one is visible inFIG. 1respectivelyFIG. 3. The small bosses50may cooperate with hook-shaped slots in the inside wall of the casing near the filling aperture as indicated at52inFIG. 5. The slots52comprises an insertion portion54running parallel to the casing's center axis and a circumferential segment56fitted with a constriction58near the end. The affixation ring is inserted through the filling aperture12into the filling neck10, the small bosses50being aligned with the insertion portions54. Next the said ring is rotated slightly, as a result of which the small bosses50enter the circumferential portions56. They overcome the constricted cross-section58and in this manner are affixed in the filling neck10in approximately secured manner.

Accordingly the drive ring22is fixed in position relative to the filling aperture12using the affixation ring48. A drive ring is simply omitted where unnecessary and only the affixation ring48is rotated into position during assembly. When exchanging the drive ring22is required respectively the filling neck must be serviced, the drive ring22is very easily removed merely by loosening the affixation ring48.

On its side facing the filling aperture12, the affixation ring is fitted with diametrically opposite holes60. A tool may thus be applied to loosen the affixation ring during assembly or dismantling. The drive ring22also may be fitted for instance with two holes to more easily assemble/dismantle it when the affixation ring48has been removed.

As already mentioned above,FIG. 3shows the fuel nozzle26inserted in the filling neck10. The filling nozzle's diameter being slightly larger than that of the narrower cross-section58of the drive ring22, latter expands radially thereby and allows unlocking the sealing flap30as discussed above in relation toFIG. 4. As a result the sealing flap pivots into the open position. By actuation the filling nozzle, the fuel can be freely fed into the filling pipe14. When the filling nozzle26is pulled out, the flap30automatically returns into its closed position where it is locked by the hooked portions36,38, as already elucidated in relation toFIG. 4.