Tank system for a reducing agent

Abstract

A tank system for a reducing agent includes: a vessel configured to store the reducing agent, the vessel having: an upper vessel wall, lateral vessel walls, and a lower vessel wall; and a conveying device, the conveying device being configured to provide the reducing agent under pressure by way of an outlet to an exhaust gas. One or more openings are arranged in the lower vessel wall the one or more openings forming a connection to a further volume (V) filled with reducing agent. At least one opening of the one or more openings has radially inwardly directed elements arranged on a circumference of the at least one opening.

Claims

1. A tank system for a reducing agent, comprising a vessel for the reducing agent, having an upper vessel wall, lateral vessel walls and a lower vessel wall, comprising a conveying device in order for the reducing agent to be provided so as to be suppliable under pressure via an outlet to an exhaust gas, characterized in that at least one opening (6, 6) is arranged in the lower vessel wall (4), in that the at least one opening (6, 6) forms a connection to a further volume (V) filled with reducing agent, and in that at least one opening (6) has radially inwardly directed elements (13) arranged on the circumference (16).

2. The tank system as claimed in claim 1, characterized in that the at least one opening (6) is an opening (6) arranged relatively close to the center of the vessel (1).

3. The tank system as claimed in claim 1 or 2, characterized in that the elements (13) are formed in one piece with the vessel wall (4).

4. The tank system as claimed in at least one of the preceding claims, characterized in that the elements (13) have the same thickness as the vessel wall (4).

5. The tank system as claimed in at least one of the preceding claims 1 to 3, characterized in that the elements (13) have a smaller thickness than the vessel wall (4).

6. The tank system as claimed in at least one of the preceding claims, characterized in that the elements (13) have, along the diameter of the opening (6), a length of 0.2 to 0.9, preferably 0.4 to 0.7, times the diameter.

7. The tank system as claimed in at least one of the preceding claims, characterized in that the elements (13) are arranged with a spacing to one another.

8. The tank system as claimed in claim 7, characterized in that the width of the spacing between two elements (13) amounts to between 1.0 and 0.05 times the width of an element (13).

9. The tank system as claimed in claim 7 or 8, characterized in that the spacing between two elements (13) in the region (15) of the circumference (16) of the opening (6) is greater than the directly adjoining region (17) of the spacing.

10. The tank system as claimed in at least one of the preceding claims, characterized in that one to ten elements (13) are arranged on the at least one opening (6).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The invention will be discussed in more detail on the basis of multiple exemplary embodiments. In the figures:

[0021] FIG. 1: is a schematic illustration of the tank system according to the invention;

[0022] FIGS. 2-8: show different openings in the vessel; and

[0023] FIG. 9-10B show further embodiments of the tank system.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0024] FIG. 1 shows a tank system having a vessel 1 which in the installed position has an upper vessel wall 2, a filling portion (not illustrated) for the reducing agent, lateral vessel walls 3, and a lower vessel wall 4. The lower vessel wall 4 forms the base of the vessel 1. The vessel 1 is composed of plastics. Openings 6 are arranged in a planar base region 5 of the lower vessel wall 4. A conveying device 7 is situated outside the vessel 1. The conveying device 7 has a flange 8, which surrounds said conveying device and which is welded to the outer side 9 of the vessel 1. The conveying device 7 together with the outer side 9 of the vessel 1 encloses a chamber, such that the conveying device 7 and the outer side 9 form a volume V. The vessel 1 is thus not penetrated by the conveying device 7. The volume V is connected to the interior of the vessel 1 by the openings 6 in the lower vessel wall 4. In this way, urea solution stored in the interior of the vessel can flow through the vessel wall 4 to the outside into the volume V. The conveying device 7 has a housing 10, in or on which there can be arranged various components (not illustrated in any more detail), for example a pump, pressure regulators, heating devices, filters, fill level and quality sensors. The housing 10 furthermore comprises a lid 11, which closes the housing 10. By the pump, the urea solution situated in the volume V can be suctioned and supplied under pressure via an outlet 12 into a conveying line of an exhaust line, in which conveying line the urea solution is admixed to the exhaust gas. Owing to the exposed position of the conveying device 7 on the outer side of the vessel 1, the volume V is relatively sensitive to temperature influences. In particular in the presence of low temperatures, the volume V freezes before the adjacent volume in the interior of the vessel 1. The associated volume enlargement in the volume V has the effect that, owing to the two outer openings 6, the volume V can expand in the direction of the vessel 1, whereby critical stresses in the volume V and thus in the conveying device are avoided. In relation to the volume V, the urea solution freezes last in the region of the central opening 6, which is arranged relatively close to the center of the vessel 1, and the urea solution would press against the outer side 9 of the vessel wall 4 in the base region 5. The construction of the opening 6 according to the invention prevents this. The form of the opening 6 will be described with reference to the following figures.

[0025] FIG. 2 shows an opening 6 with an element 13 that has a length of 0.8 times the diameter of the opening 6. FIG. 3 shows an opening 6 with two elastically deformable elements 13. FIG. 4 illustrates three elastic elements 13. The trapezoidal elements 13 are arranged spaced apart from one another, wherein the spacings are formed as slots 14 that have boundaries running parallel. In FIG. 5, four elements 13 are arranged in an opening 6. The spacing between two elements 13 in the region 15 of the circumference 16 of the opening 6 is greater than the directly adjoining region 17.

[0026] FIGS. 6 to 8 show further refinements of the elements 13.

[0027] The vessel in FIG. 9 is of a construction similar to that in FIG. 1. The base region 5 is configured as an inwardly protruding portion 18 that is directed into the interior of the vessel 1. Owing to this inwardly protruding portion 18, the volume of the vessel 1 is smaller than in the case of a planar design of the base region 5 as in FIG. 1. The conveying device 7 is arranged on the outer side 9 of the vessel 1 in the base region 5, the flange 8 of the conveying device being welded to the outer side 9 such that the conveying device 7 and the outer side 9 of the vessel 1 form the volume V. The connection to the interior of the vessel is realized via openings 6, which are arranged so as to be distributed over the inwardly protruding portion 18. Owing to this distribution, the openings 6, 6 are arranged with different spacings to the lower vessel wall 4. The housing 10 with the components arranged therein extends in the direction of the vessel 1 and thus projects into the region excluded by the inwardly protruding portion 13. The tank system thus requires less installation space toward the bottom. Here, the conveying device 7 is still, as in FIG. 1, arranged entirely outside the vessel 1. For simpler production of the vessel 1 as a result of improved demolding capability, the inwardly protruding portion 13 is of conical form. Here, the opening 6 is arranged centrally in the inwardly protruding portion 18. The elements 18 as per FIG. 4 are illustrated in the elastically deformed state.

[0028] FIGS. 10A, 10B show a further embodiment with a much larger opening 6, wherein FIG. 10A shows a section in accordance with FIG. 9 and FIG. 10B shown a plan view of FIG. 10A. It can be seen here that the slots 14 extend from the upper, planar region into the region of conical form of the inwardly protruding portion 18.

[0029] Thus, while there have been shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention.

[0030] Moreover, it should toe recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.