TANK FOR AN OPERATING LIQUID FOR A MOTOR VEHICLE

Abstract

Tank for an operating liquid for a motor vehicle. Tank (1) for an operating liquid for a motor vehicle (2) with a tank wall (3) made of plastic, having an opening (4) and an insert (5), made of metal, arranged at the opening (4), and a flexible sealing element (6) for interconnecting, in a liquid-tight manner, the tank wall (3) and the insert (5), wherein, on account of thermal expansion of the tank wall (3) and of the insert (5), relative displacements (7) arise between the tank wall (3) and the insert (5) and the flexible sealing element (6) is configured such that sealing faces (8, 16) are formed both on the insert (5) and on the tank wall (3), against which faces the sealing element (6) bears independently of the relative displacements (7).

Claims

1. A tank for an operating liquid of a motor vehicle, comprising: a tank wall having an opening, the tank wall being made of plastic; an insert arranged such that the insert partially extends into the opening, the insert being made of metal; a flexible sealing element providing a liquid-tight connection between the tank wall and the insert; and a plurality of sealing surfaces being part of the flexible sealing element, at least one of the plurality of sealing surfaces being in contact with the tank wall, and another of the plurality of sealing surfaces being in contact with the insert; wherein relative displacements between the tank wall and the insert occur at least in sections due to thermal expansions of the tank wall and of the insert, and the sealing element bears against the insert and the tank wall along the plurality of sealing surfaces independently of the relative displacements between the tank wall and the insert.

2. The tank of claim 1, the insert further comprising a housing for accommodating a delivery unit for the delivery of operating liquid out of the tank.

3. The tank of claim 1, wherein the opening has a diameter of greater than 100 millimeters.

4. The tank of claim 1, the flexible sealing element further comprising: a sealing ring; a first abutment surface being part of the sealing ring, the first abutment surface being in contact with the tank wall; a second abutment surface being part of the sealing ring, the second abutment surface in contact with the insert; wherein the first abutment surface and the second abutment surface are larger than a maximum relative displacement between the tank wall and the insert which occurs due to thermal expansion.

5. The tank of claim 1, further comprising: a first sealing surface being part of the tank wall; and a second sealing surface being part of the insert; wherein the flexible sealing element rolls on the first sealing surface on the tank wall and on a second sealing surface on the insert as the tank wall and the insert move relative to one another due to thermal expansion.

6. The tank of claim 1, the flexible sealing element further comprising a tube-type sealing ring.

7. The tank of claim 1, the flexible sealing element further comprising: a diaphragm; a first section being part of the diaphragm, the first section of the diaphragm being connected cohesively to the tank wall; a second section being part of the diaphragm, the second section of the diaphragm being connected cohesively to the metallic insert; a flexibility zone located between the first section and the second section, the flexibility zone being part of the diaphragm; wherein the flexibility zone compensates for relative displacement between the tank wall and the insert due to thermal expansion.

8. The tank of claim 1, the motor vehicle further comprising: an internal combustion engine; an exhaust-gas treatment device operable with the internal combustion engine for purifying exhaust gas; and an SCR catalytic converter being part of the exhaust-gas treatment device; wherein the tank stores and supplies liquid additive for exhaust-gas purification performed by the exhaust-gas treatment device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0036] FIG. 1: shows a first embodiment of a described tank,

[0037] FIG. 2: shows a second embodiment of a described tank,

[0038] FIG. 3: shows a third embodiment of a described tank,

[0039] FIG. 4: shows a fourth embodiment of a described tank,

[0040] FIG. 5: shows a schematic diagram of displacements occurring in a described tank, and

[0041] FIG. 6: shows a motor vehicle having a described tank.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0043] FIGS. 1, 2, 3 and 4 show in each case four different design variants of a described tank 1 with a tank wall 3. In the tank wall 3 there is provided an opening 4 into which there is inserted an insert 5 which is sealed off against the tank by way of a sealing element 6. In all of the design variants illustrated in FIGS. 1-4, the insert 5 is a housing 9 which is suitable for accommodating a delivery unit 10 for supplying liquid additive for exhaust-gas purification from the tank to an exhaust-gas treatment device. FIG. 4 illustrates the delivery unit in slightly more detail by way of an example, wherein the structure of a delivery unit 10 explained in FIG. 4 is also highly simplified. The delivery unit 10 has a pump 30 and extracts operating liquid from the tank 1 at a suction point 29 and supplies the operating liquid at the supply port 31. The supply port 31 serves for example for the attachment of a line (not illustrated in any more detail here) which leads to an injector for the dispensing of the operating liquid into an exhaust-gas treatment device.

[0044] In the design variants in FIGS. 1 to 3, the insert 5 is fastened to the tank wall 3 in each case by way of a separate mounting means 33. The separate mounting means 33 includes a flange 34 on the tank wall 3 and a cover 28 which is fitted onto the flange 34 (for example by being screwed on or plugged on). The insert 5 is braced between the cover 28 and the tank wall 3. Thus, firstly, displacements of the insert 5 perpendicular to the tank wall 3 are prevented. Secondly, the mounting means 33 composed of flange 34 and cover 28 permits relative displacements between insert 5 and tank wall 3 parallel to the tank wall 3.

[0045] In the design variant in FIG. 1, the sealing element 6 is a sealing ring 12. The sealing ring bears against the insert by way of a second abutment surface 14 and against the tank wall 3 by way of a first abutment surface 13, and thus seals off the tank wall 3 and the insert 5 with respect to one another.

[0046] In the design variant in FIG. 2, the sealing element 6 is a diaphragm 17 which has a first section 18 which is fastened to the tank wall 3 and a second section 19 which is fastened to the insert 5, wherein, between the first section 18 and the second section 19, there is arranged a flexibility zone 20 which permits relative displacements between the insert 5 and the tank wall 3.

[0047] FIG. 3 shows a design variant of the sealing element 6 which is a tube-type sealing ring 15. A tube-type sealing ring 15 is particularly suitable for forming a rolling sealing element 6, because, in a tube-type sealing ring 15, less internal shear forces, which adversely affect the tube-type sealing ring 15, arise during a rolling movement.

[0048] The tank 1 is illustrated merely schematically in FIG. 4. Here, the insert 5 is inserted into a section of the tank wall 3 which forms an intermediate component 26. The intermediate component is connected to the further tank wall 3 by way of a welded connection 27. The intermediate component 26 forms a type of intermediate flange which serves for secure fluid-tight attachment of the metallic insert 5 to the plastics tank wall and which thereby permits the mounting of the insert 5 in the tank wall 3. In FIG. 4, the concept as per FIG. 2 is realized as the sealing concept for the insert 5 in the tank wall 3. The intermediate component 26 may however also be combined with the other sealing concepts described here (as per FIG. 1 or FIG. 3).

[0049] FIG. 5 describes the relative displacements 7 that may occur as a result of thermal expansions of the tank wall 3 and of the insert 5. FIG. 5a shows a situation in which the insert 5 and the tank wall 3 have been pulled apart to a particularly great extent. FIG. 5b shows a situation in which the insert 5 and the tank wall 3 bear particularly closely against one another. For example, the situation as per FIG. 5b exists in the case of particularly low (minimum) temperatures, whereas the situation as per FIG. 5a exists in the case of particularly high (maximum) temperatures. The assignment of minimum temperatures and maximum temperatures to figure parts a) and b) in this case is however merely exemplary. It is in fact also possible here (depending on tank geometry and coefficients of thermal expansion of tank wall and insert) for the exactly reversed situation to exist, such that FIG. 5b corresponds to maximum temperatures and FIG. 5a corresponds to minimum temperatures. It is possible to see in each case a first sealing surface 8 between the sealing element 6 and the tank wall 3 and a second sealing surface 16 between the insert and the sealing element 6, which sealing surfaces are in each case covered by the sealing element 6 independently of the position of the insert 5 and of the tank wall 3 relative to one another. It is to be pointed out that A for example indicates an arrow in which the maximum possible temperatures admissible for the tank prevail, whereas arrow B shows a situation in which the minimum temperatures possible for the tank prevail. Also indicated in FIG. 5 is a maximum rolling angle 32 through which the sealing element 6 rolls on the tank wall 3 and on the insert 5.

[0050] FIG. 6 shows a motor vehicle 2 having an internal combustion engine 22 and having an exhaust-gas treatment device 23, in which there is situated an SCR catalytic converter 24 for the purification of the exhaust gases of the internal combustion engine 22. The SCR catalytic converter 24 is fed with liquid additive for exhaust-gas purification by an injector 25, which liquid additive is supplied to the injector 25 from a tank 1 via a line 21 by a delivery unit 10.

[0051] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.