Filler neck for the fuel tank of a motor vehicle with selective opening

A filler neck for the fuel tank of a motor vehicle has a funnel insert having a lockable flap with a lock, which is held by two elements which can each be pivoted about a pin. The flap is released only when both elements are pivoted to one side simultaneously by the filler tube of a gas pump nozzle. In order to open the flap with minimal actuating forces, the first element can be pivoted about a first pin and holds the hinge pin for the flap on its end far from the first pin, and the second element can be pivoted about a second pin and forms a locking hook. The two pins have a spatial distance from one another in the transverse direction and the two elements are loaded with respect to one another by at least one spring.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.SC. §119 to German Patent Application No. 10 2011 011 518.8 (filed on Feb. 17, 2011), which are each hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to a filler neck for the fuel tank of a motor vehicle with a funnel insert and adjoining it at an inward direction a flap with a lock. The flap is held in a rotatable manner about a hinge pin that can be displaced in space and by two elements which can each be pivoted about a pin. The flap is released only when both elements are pivoted to one side simultaneously by the filler tube of a gas pump nozzle.

It is thereby achieved in the case of tanks for diesel fuel that the flap is unlocked and can be opened only upon insertion of the filler tube of a gas pump nozzle with sufficiently large diameter. A filler tube for gasoline has a smaller diameter so that both elements cannot be pivoted simultaneously. Because fuelling with incorrect fuel generally leads to the destruction of the engine, this must be prevented at all cost.

BACKGROUND OF THE INVENTION

A generic filler neck is known from WO 2006/007618 A1. Because the hinge pin of the flap and the lock thereof are not fixed in space, the flap and the elements holding it can orient themselves in space in accordance with an oblique positioning of a filler tube with small diameter. It is thus no longer possible to circumvent the locking means.

Upon the insertion of a filler tube with the “correct” diameter, this rides on two cams facing towards one another of the elements, and the two elements are simultaneously forced outwards. However, it has been shown that the elements pivoted about a common pins are kinematically unfavorable, because the force in the longitudinal direction necessary to open the lock and the wear of the cams is very great.

SUMMARY OF THE INVENTION

The problem on which the invention is based is therefore to further develop a generic filler neck such that the opening of the flap requires minimal activating forces and a further enhanced reliability of the function is achieved with the lowest possible production costs.

In accordance with the invention, this is essentially achieved in that the two elements can be pivoted about pins spaced apart from one another in the transverse direction, and that they are loaded with respect to one another by the force of the spring acting between them. The axes spaced apart from one another lie approximately over the contact point of the filler tube of the gas pump nozzle and the normal on the contact point is very far removed from the pin of the element. The favorable kinematic and force ratios achieved thereby result—with the “correct” filler tube—in an easy opening of the flap and low wear. Because the spring force acts between the elements (and not between them and the filling funnel or the filler neck), its effect on both elements is fully retained even if a filler tube of the gas pump nozzle is inserted obliquely. It, therefore, cannot be circumvented, even with great skill.

In an embodiment that is favorable in every respect, the bearing for the elements is arranged on both sides of the funnel insert and respectively one bearing part is in one piece with the funnel insert and the second bearing part is in one piece with the element. This means that a low number of components and, due to the bearings of respectively one element spaced far apart from one another, a stable bearing of the elements is achieved. To this end, the elements are advantageously embodied such that they respectively form a bracket surrounding the funnel insert from one bearing to the other and merge towards the interior of the tank into the hinge or into the locking hooks.

In an advantageous embodiment, the bearing for the first and for the second elements is respectively composed of hollow cylinders with an opening on the funnel insert or on the element and of flattened journal pins on the element or on the funnel insert. The openings and the flat spots are arranged such that during assembly—before the installation into the filler neck—the journal pins can be inserted into the hollow cylinders and then are pivoted downwards into their operating position. In this position, the journal pins can no longer leave the hollow cylinders. In a preferred embodiment, the hollow cylinders are shaped with the opening on the funnel insert, but they can also be attached to the elements.

In an alternative embodiment, the bearing of the first and second element is respectively composed of cylindrical journals without flat spots and of closed hollow cylinders, such that the elements are elastically flexible so that they can be bent up during assembly. Preferably, the journals are respectively arranged on the funnel insert.

In a further particularly advantageous embodiment, the bearing of the first and second element is respectively composed of cylindrical journals and of closed hollow cylinders, such that the elements are produced by way of injection into a mold in which the funnel insert is inserted. This production method is also referred to as coating, such that the parts of the funnel insert exposed in the mold are provided with a release layer usually applied in a liquid manner. Here, too, preferably the journal is respectively embodied on the funnel insert and the hollow cylinder on the element.

An advantageous detail lies in that the elements are loaded with respect to one another by means of at least one (or two) helical tension springs acting thereon below the bearing. This produces a large spring force in all angular positions of the elements and increases security.

DETAILED DESCRIPTION OF EMBODIMENTS

As illustrated inFIG. 1the filler neck1belonging to a fuel tank1(not shown) is indicated by a dashed line, because the shape thereof and optionally further installations are irrelevant for the invention. The funnel insert2with a flap4on its lower end is essential. The funnel insert2is attached, for example, by way of parts11in the filler neck1, but can be attached in any other desired manner. The flap4can be pivoted inwards by a hinge pin5. The filler tube of a gas pump nozzle10is merely indicated and the center line of the filler neck1is marked by3. A first element6is hinged in a pivoted manner about a first pin8and a second element7about a second pin9on the funnel insert2. The pins8,9are arranged at the same height at a distance12from one another, which distance is approximately as large as (here it is somewhat smaller than) the width of the flap4.

The first element6is swivel-mounted near to its upper end on both sides of the funnel insert2and has on its lower end the hinge pin5for the flap4and a side spring28loading it in the closing direction. The second element7is also swivel mounted on both sides of the funnel insert2and forms on its lower end a locking hook24, which holds the flap4in the closed position until the filler tube10with the correct (larger) diameter simultaneously presses both ramps25,26outwards. The ramps25,26are embodied on the two elements6,7and indicated by dashed lines inFIG. 1. They can be seen better inFIG. 4.

As illustrated inFIG. 2, which is a view rotated by 90 degrees fromFIG. 1, it can be seen that the second element7(as well as the first element6) is supported on both sides of the funnel insert2by way of respectively one bearing13,14. The two bearings have a distance15from one another and can be embodied differently in accordance with the invention, as can be seen in the following figures.

As illustrated inFIGS. 3 and 4, the subject matter of the invention is provided in a three-dimensional manner. Firstly, it is discernible that the two elements6,7are the brackets21,22connecting the bearings13,14lying far apart from one another and surrounding the funnel insert2on the outside, which brackets merge downwards into a locking hook24or into a hinge part23. The hinge part23is wound about by the side spring28and contains a pin27riveted at its ends as hinge pin for the flap4. In their center the brackets form ramps25,26, which project through windows20(FIG. 4) into the interior of the funnel insert2. Between the two elements6,7under the pins8,9a helical tension spring29is attached, which draws the elements6,7towards one another, and thus, holds the flap4locked. Up to this point the description applies to all embodiments and variants.

As illustrated inFIG. 5, the bearings13,14, which are respectively identical for both elements6,7, are provided in a first embodiment. The bearings13,14are formed by two bearing parts, respectively, one on the funnel insert2and one on the elements6,7. The bearing parts are hollow cylinders32shaped on the funnel insert2with respectively one opening33. The opening33is approximately facing towards the wall of the filler neck1. Journal pins34with planar flat spots on both sides are shaped on the elements6,7. The flat spots35are aligned such that they can be inserted through the openings33(arrow36) only when the element is in the approximately horizontal position (seeFIG. 5a)). This position is possible only before the funnel insert2thus assembled is inserted into the filler neck1. But not in the installed position pivoted downwards (seeFIG. 5B. Likewise as a variant, however, the hollow cylinders with opening could also be shaped on the elements6,7and the journals with flat spot on the funnel insert.

The embodiment ofFIG. 6differs from that just described in that a hollow cylinder42closed all around and a cylindrical journal40without flat spots replace the parts32,34of the first embodiment. For the production or assembly, there are two possibilities. Either the brackets21,22of the elements6,7are bent elastically apart so that on both sides only the short journals40can snap into the hollow cylinders42. Or the production of the elements6,7is carried out “in situ” in accordance with a recently possible method: the funnel insert2is placed into a mold such that only the surfaces then coming into contact with the elements6,7are exposed. These surfaces are provided with a coating that prevents a connection by adhesive force of the plastic (with lower melting point) injected subsequently into the correspondingly designed mold to form the elements.