Filler Neck for a Vehicle with Improved Diffusion Resistance

Abstract

A tank filler neck for a motor vehicle including a tube having an outer tube portion and an inner tube portion, a barrier layer embedded between the outer tube portion and an inner tube portion, the barrier layer having a thickness at a first region thereof that is greater than a thickness than remaining regions thereof, and a seal arranged to directly contact the barrier layer at the first region. In that way, the barrier layer is to inhibit diffusion of hydrocarbons through the tube at a first region more than the remaining portion(s) the plastic tube.

Claims

1. A tank filler neck for a motor vehicle, comprising: a tube having a barrier layer which inhibits diffusion of hydrocarbons through the tube at a first region thereof greater than in remaining regions thereof; a filler head surrounding the tube at an end thereof; and a seal composed of an elastomer arranged between the plastic tube and the filler head, and which directly contacts the barrier layer.

2. The tank filler neck of claim 1, wherein the seal directly contacts the barrier layer at the first region.

3. The tank filler neck of claim 1, wherein barrier layer has a thickness that is greater in the first region than in remaining portions thereof.

4. The tank filler neck of claim 1, wherein the barrier layer is embedded into the tube.

5. The tank filler neck of claim 1, wherein the barrier layer is composed of ethylene vinyl alcohol copolymer.

6. The tank filler neck of claim 1, wherein the seal is arranged radially to the outside of the barrier layer.

7. The tank filler neck of claim 1, wherein the seal is arranged axially to the outside of the barrier layer.

8. The tank filler neck of claim 1, wherein the barrier layer comprises a groove, and the seal is arranged in the groove.

9. A tank filler neck for a motor vehicle, comprising: a tube having an outer tube portion and an inner tube portion; a barrier layer embedded between the outer tube portion and an inner tube portion, the barrier layer having a thickness at a first region thereof that is greater than a thickness than remaining regions thereof; and a seal arranged to directly contact the barrier layer at the first region.

10. The tank filler neck of claim 9, wherein the barrier layer is composed of ethylene vinyl alcohol copolymer.

11. The tank filler neck of claim 9, wherein the seal is arranged radially to the outside of the barrier layer.

12. The tank filler neck of claim 9, wherein the seal is arranged axially to the outside of the barrier layer.

13. The tank filler neck of claim 9, wherein the barrier layer comprises a groove, and the seal is arranged in the groove.

14. A motor vehicle, comprising: a tank filler neck including: a tube having an outer tube portion and an inner tube portion; a barrier layer embedded between the outer tube portion and an inner tube portion, the barrier layer having a thickness at a first region thereof that is greater than a thickness than remaining regions thereof; and a seal arranged to directly contact the barrier layer at the first region.

15. The motor vehicle of claim 14, wherein the barrier layer is composed of ethylene vinyl alcohol copolymer.

16. The motor vehicle of claim 14, wherein the seal is arranged radially to the outside of the barrier layer.

17. The motor vehicle of claim 14, wherein the seal is arranged axially to the outside of the barrier layer.

18. The motor vehicle of claim 14, wherein the barrier layer comprises a groove, and the seal is arranged in the groove.

Description

DRAWINGS

[0024] Embodiments will be illustrated by way of example in the drawings and explained in the description below.

[0025] FIG. 1 illustrates a related art tank filler neck.

[0026] FIG. 2 illustrates a detail view of the tank filler neck of FIG. 1.

[0027] FIG. 3 illustrates a tank filler neck with a seal seated radially on the barrier layer, in accordance with embodiments.

[0028] FIG. 4 illustrates a tank filler neck with a seal seated axially on the barrier layer, in accordance with embodiments.

DESCRIPTION

[0029] FIG. 3 illustrates a tank filler neck 1a for a motor vehicle, said filler neck comprising a tube 2 composed, for example, of a plastic material. The tube 2 has a tubular barrier layer 3 positioned intermediate to outer and inner layers of the tube 2. The barrier layer 4 is to inhibit diffusion of hydrocarbons more than remaining portion(s) the plastic tube 2. The barrier layer 3 can be composed, for example, of ethylene vinyl alcohol copolymer (EVOH).

[0030] A filler head 4 composed, for example, of metal surrounds the tube 2 at an end thereof.

[0031] A seal 5 composed, for example, of an elastomeric material is spatially arranged between the plastic tube 2 and the filler head 4. In particular, the seal 5 can be produced from a rubber and/or can be designed as an O-ring. The seal 5 can be, for example, manufactured from acrylonitrile butadiene rubber (NBR), fluororubber (FPM/FKM) or fluorosilicone (FVMQ).

[0032] In accordance with embodiments, the seal 5 directly contacts at least a portion of the barrier layer 3. Due to this arrangement, diffusion of hydrocarbons to the outside while bypassing the barrier layer 3 and the seal 5 is prevented. The leaktightness of the system is thereby significantly improved.

[0033] As illustrated in FIG. 3, the barrier layer 3 is advantageously embedded into the tube 2. As a result, the barrier layer 3, which is often just a few tenths of a millimeter thick for reasons of cost, is well protected. When seen in cross-section, the barrier layer 3 can therefore be seen as circular, the diameter of which is greater than an inside diameter of the tube 2, and less than an outside diameter of the tube 2.

[0034] In accordance with embodiments, the tube 2, for example, can be embodied as a multilayer plastic blowmolding with (in particular) a plurality of layers (such as, e.g., seven layers), in which an impermeable EVOH barrier layer 3, which is bonded to the HDPE layers by adhesion promoters, is situated in the centre between different layers of high-density polyethylene (HDPE). Modified low-density polyethylene (LDPE), for example, can be used as an adhesion promoter.

[0035] The barrier layer 3 may not necessarily provide 100% prevention of diffusion. The barrier layer 3, however, is to at least inhibit diffusion, i.e., the permeability of the barrier layer 3 is less than the permeability of the remaining portion(s) the tube 2.

[0036] In the example illustrated in FIG. 3, the seal 5 is arranged radially to the outside of the barrier layer 3. To be specific, the seal 5 is arranged in a groove, and the base of the groove is formed by the barrier layer 3. For example, the groove can be produced by milling or sawing. The groove can also be produced directly during the extrusion of the plastic tube 2 for example, e.g., by briefly switching off an external HDPE extruder, which is provided for a layer lying outside the barrier layer 3.

[0037] In general, it is advantageous if the barrier layer 3 is made thicker in the region of the seal 5 that contacts the barrier layer 3 than in the remaining portion(s) the plastic tube 2, as illustrated in FIG. 3. In this way, tolerances in respect of the position of the barrier layer 3, the seal 5 and the groove can be compensated more effectively. In particular, this applies to the embodiments in which the groove is produced by machining.

[0038] FIG. 4 then illustrates an embodiment of a tank filler neck 1b which is very similar to the tank filler neck 1a illustrated in FIG. 3. In contrast thereto, however, the seal 5 is not arranged radially to the outside of the barrier layer 3 but is arranged axially to the outside of the barrier layer 3. Here too, it is advantageous if the barrier layer 3 is made thicker in the region of the seal 5 that contacts the barrier layer 3 than in the remaining portion(s) the plastic tube 2, as illustrated in FIG. 4. In this way, the tank filler neck 1b remains leaktight even if the seal 5 is not resting exactly centrally on the barrier layer 3. The barrier layer 3, for example, can be exposed by sawing or face milling.

[0039] In conclusion, it is noted that the components in the figure may not be illustrated to scale. Position indications such as right, left, top, bottom and the like refer to the illustrated position of the respective component and must be notionally revised accordingly when said position changes. It is furthermore noted that the tank filler neck 1a, 1b illustrated can, of course, have more or fewer components than illustrated without thereby departing from the basic concept of embodiments.

[0040] The term coupled or connected may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms first, second, etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.

[0041] This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of embodiments is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. Aspects from the various embodiments described, as well as other known equivalents for each such aspects, may be mixed and matched by one of ordinary skill in the art to construct additional embodiments and techniques in accordance with principles of this application.