FUEL TANK

Abstract

The invention relates to a fuel tank for a motor vehicle, comprising a tank body made from thermoplastic with a tank wall which defines a tank volume which can be closed in a substantially fluid-tight manner, with at least one filler opening and with one or more functional insert components which are arranged within the tank volume, at least one blind opening with a single use closure being provided in the tank wall.

Claims

1-10. (canceled)

11. A fuel tank for a motor vehicle, comprising a tank body made from thermoplastic with a tank wall which defines a tank volume which can be closed in a substantially fluid-tight manner, with at least one filler opening and with one or more functional insert components which are arranged within the tank volume and which are selected from a group comprising a fuel delivery unit which comprises at least one baffle container and a fuel delivery pump, one or more suction jet pumps, one or more filling level sensors, one or more venting valves and one or more rollover safety valves, at least one blind opening with a single use closure being provided in the tank wall, the blind opening being covered and sealed outside the tank volume by way of a closure cap, and the closure cap being connected releasably to the tank wall, characterized in that the blind opening has a surround with an internal thread, and in that the surround is configured as a circumferential bulge which has a greater thickness than the tank wall outside the surround.

12. The fuel tank as claimed in claim 11, wherein the blind opening is configured as an integral shaped-out formation of the tank wall.

13. The fuel tank as claimed in claim 11, wherein the blind opening has a predetermined break line in the tank wall, which predetermined break line defines a disk-shaped cap which can be detached from the tank wall as a single use closure.

14. The fuel tank as claimed in claim 13, wherein the closure cap is configured as a screw cap and has a thread which is of complementary configuration with respect to the thread of the surround.

15. The fuel tank as claimed in claim 13, wherein the cap is provided with a grip tab.

16. The fuel tank as claimed in claim 15, wherein the grip tab extends parallel to and partially at a spacing from the cap and is arranged eccentrically on the cap, with the result that lever forces can be introduced via the grip tab into the predetermined break line which delimits the cap.

17. The fuel tank as claimed in claim 11, wherein the tank wall has at least one bead which runs around the surround.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In the following text, the invention will be described using one exemplary embodiment which is shown in the drawing, in which:

[0036] FIG. 1 shows a section through a part of the tank wall of a fuel tank according to the invention in accordance with a first exemplary embodiment in the region of the closed blind opening;

[0037] FIG. 2 shows a section which corresponds to FIG. 1 through the tank wall of a fuel tank in the region of the blind opening in accordance with a second exemplary embodiment of the invention;

[0038] FIG. 3 shows a section through a part of the tank wall of a fuel tank according to the invention in accordance with a third exemplary embodiment in the region of the closed blind opening; and

[0039] FIG. 4 shows a section which corresponds to FIG. 3 through the tank wall of a fuel tank in accordance with a further exemplary embodiment of the invention.

DETAILED DESCRIPTION

[0040] The fuel tank 1 according to the invention is not shown completely in the figures. It comprises a tank body with a tank wall 2 made from thermoplastic.

[0041] The tank wall 2 consists of a multiple layer extrudate made from thermoplastics on the basis of polyethylene. Only two layers of the tank wall 2 are shown in outlines in the drawings, but the invention is to be understood in such a way that the tank wall 2 can certainly have a plurality of layers, for example said tank wall 2 can be configured overall with six layers and can comprise two structuring layers and at least one barrier layer which is arranged in between.

[0042] FIG. 1 shows a section through the tank wall 2 in the region of a blind opening 3 which is configured as an integral shaped-out formation of the tank wall. The tank wall 2 encloses a tank volume 4 which is faced by the inner side of the tank wall 2. On the side which faces away from the tank volume 4, the blind opening 3 is configured as a depression of the tank wall 2. The blind opening 3 therefore forms a blind bore in the outer side of the tank wall 2. On the outer side of the tank wall 2, the blind opening 3 is closed tightly by means of a screw cap 5. The blind opening 3 is delimited by way of a surround 6 which is provided with a thread 7 which interacts with a corresponding thread 7 of the screw cap 5.

[0043] According to the invention, the blind opening 3 is configured as a single use closure of the fuel tank 1, the single use closure being formed by way of a disk-shaped cap 8 which is defined by way of a completely circumferential predetermined break line 9 in the tank wall 2.

[0044] The blind opening 3, the surround 6, the thread 7 of the surround and the screw cap 5 are rotationally symmetrical and circular in the plan view. A grip tab 10 is fastened to the cap 8 on that side of the cap 8 which faces away from the tank volume 4. The grip tab 10 comprises a first end 11 which forms the root region of the grip tab 10 and a second end 12 which is configured as a grip end and projects from the outer face of the cap 8, with the result that it can be reached under there by way of a finger of the hand of an operator. The grip tab 10 is arranged eccentrically on the cap 8 in such a way that the first end 11 of the grip tab 10 adjoins the predetermined break line 9, with the result that, if the second end 12 of the grip tab is reached under, as shown in outlines in FIG. 2, lever forces are introduced into the predetermined break line 9 in such a way that first of all the cap 8 can be pressed in downward in the direction of the tank volume 4, with the result that the predetermined break line 9 tears. The cap 8 can then be separated completely from the tank wall 2 by way of pulling on the grip tab 10.

[0045] As has already been mentioned at the outset, the fuel tank is commissioned with the closed blind opening 3. In this state, the tank volume 4 in the region of the blind opening 3 is closed. The cap 8 is connected fixedly to the tank wall 2, and the depression which is formed by way of the blind opening 3 in the tank wall 2 is covered by way of the screw cap 5. The screw cap 5 is sealed against a circumferential sealing face of the surround 6 via a circumferential elastomer seal 13. In this state, as shown in FIG. 1, for example, the screw cap 5 is substantially without a function.

[0046] In a service case which is not to be assumed, the screw cap 5 would have to be opened. The cap 8 would have to be released from the tank wall 2 via the grip tab 10, with the result that an inspection opening which is accessible from the outside is then formed in the tank wall 2.

[0047] After the maintenance has been carried out, the screw cap 5 would have to be inserted again into the opening which is produced in this way, the screw cap 5 then actually being given the function of the sealing of the tank volume 4.

[0048] FIG. 2 shows a second exemplary embodiment of the invention, in which identical components are provided with identical designations. FIG. 2 at the same time shows the partially open state of the cap 8 with destruction of the tank wall 2 in the region of the predetermined break line 9. The screw cap 5 which is also provided in this exemplary embodiment of the invention is not shown in FIG. 2 also for reasons of simplification.

[0049] The exemplary embodiment according to FIG. 2 differs from that in FIG. 1 in that two circumferential beads 14 which are arranged at a spacing from one another are provided in the tank wall 2, which beads 14 enclose the surround 6 completely. FIG. 2 shows only one side of the tank wall with the beads 14. The beads are arranged in each case in a circular completely circumferential manner at a spacing from the surround 6 and act as springs which absorb deformation forces which are possibly introduced laterally into the tank wall 2, and therefore prevent the predetermined break line 9 from being loaded.

[0050] The exemplary embodiment according to FIG. 3 corresponds approximately to that according to FIG. 1, with the difference that an annular space which is provided in the region of the surround 6 in the tank wall 2 on the side which faces the tank volume 4 is filled by a supporting ring 15. The supporting ring 15 forms a mechanical stabilization of the surround 6 in such a way that the blind opening 3 or the predetermined break line 9 is kept free from any impact-induced lateral forces. The supporting ring 15 can be configured as a metallic supporting ring. As an alternative, the supporting ring 15 can also be configured from a comparatively strong thermoplastic. In this context, a strong thermoplastic can be understood to mean, for example, a glass fiber reinforced polyolefin. Otherwise, identical components are provided with identical designations in the exemplary embodiment according to FIG. 3 as in the remaining exemplary embodiments.

[0051] The exemplary embodiment according to FIG. 4 differs from that in FIG. 1 to the extent that the surround 6 is formed by way of a fold of the tank wall 2, that is to say the tank wall 2 is configured to be twice as thick in the region of the surround 6 as in the remaining region of the tank wall 2, and forms a bulge-like thickened portion there. Otherwise, the exemplary embodiment according to FIG. 4 corresponds to that in FIG. 1. Identical components are provided with identical designations.

LIST OF DESIGNATIONS

[0052] 1 Fuel tank [0053] 2 Tank wall [0054] 3 Blind opening [0055] 4 Tank volume [0056] 5 Screw cap [0057] 6 Surround [0058] 7 Thread of the surround [0059] 7 Thread of the screw cap [0060] 8 Cap [0061] 9 Predetermined break line [0062] 10 Grip tab [0063] 11 First end of the grip tab [0064] 12 Second end of the grip tab [0065] 13 Elastomer seal [0066] 14 Beads [0067] 15 Supporting ring