TANK FOR STORAGE AND DELIVERY OF FLUIDS INCLUDING FUNCTIONAL COMPONENTS DISPOSED ON THE TANK WALL

Abstract

A tank for motor vehicle includes a tank wall, a fill opening, an outlet opening, a plurality of functional components, and a plurality of attachment formations. The tank wall forms an outermost casing of the tank. The fill opening passes through the tank wall for inlet of operating fluid into the tank. The outlet opening passes through the tank wall for outlet of the operating fluid. The plurality of functional components are designed for pumping and/or for cleaning and/or for detecting a property and/or for changing a property of the operating fluid. The plurality of attachment formations are designed as being integral with the tank wall for positioning of a plurality of functional components on the tank wall. The functional components are disposed on segments of the tank wall, which are arranged at an incline to each other.

Description

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims priority to German Application No. 10 2015 217 763.7, filed Sep. 16, 2015. The entirety of the disclosure of the above-referenced application is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a tank for motor vehicle operating fluid for receiving a fluid, in particular an aqueous urea solution, comprising:

• • A tank wall forming an outermost casing of the tank, with an inner side adjacent to the tank interior and an outer side adjacent to the external environment of the tank,
  • A fill opening passing through the tank wall for the filling of the operating fluid into the tank,
  • An outlet opening passing through the tank wall for outlet of the operating fluid from the tank,
  • A plurality of functional components, wherein the functional components are configured for pumping and/or for cleaning and/or for detection of a property and/or for changing a property of the operating fluid, and
  • A plurality of attachment formations formed integral with the tank wall for arranging a plurality of functional components on the tank wall.

DESCRIPTION OF THE RELATED ART

A tank of this type for motor vehicle operating fluid is known from EP 2 029 865 B1. An attachment plate or base plate which covers a tank opening at the bottom of the tank is disposed on the interior side of this tank. The base plate is a part of the outermost casing of the tank and thus forms a part of the tank wall. The base plate includes an outlet opening through which the operating fluid can flow. In addition, at least one functional component is disposed on the base plate. Furthermore, the base plate can include a cavity so that the wall segments of the base plate divide the tank interior into a plurality of partial volumes, wherein the at least one functional component can be disposed inside this cavity. According to the teaching of EP 2 029 865 B1, the number of assembly steps needed for attachment of functional components to the tank wall can be reduced by all functional components being disposed on the base plate. Consequently, the assembly of the functional components is completed in that the base plate plus all functional components disposed on the base plate are attached to the tank wall as a pre-mounted subassembly of functional components. However, the simplified assembly of a tank known from EP 2 029 865 B1 is accompanied by a loss of design flexibility.

SUMMARY OF THE INVENTION

Usually the base plates or pre-mounted subassemblies of functional components known from the prior art are attached to a pre-defined attachment formation of the tank. However, due to space constraints in the motor vehicle, it is not always possible to dispose the pre-mounted subassembly of functional components at the pre-defined attachment formation on the tank.

In addition, to perform their function of pumping and/or cleaning and/or detecting a property and/or changing a property of the operating fluid in a satisfactory manner, functional components of this kind (such as a capacitive fill level sensor or a capacitive quality sensor)—which require a differing orientation from each other due to their physical operating principle and usage—must be arranged on the base plate such that when the base plate is mounted to the tank, they will be disposed in a pre-defined orientation relative to the expected surface level of the operating fluid occurring in the tank interior. If the base plate is designed as a flat wall component, then the possibility to arrange the individual functional components in mutually different orientations is limited. This the situation can indeed be remedied in that the base plate is produced with mutually inclined assembly segments on which the individual functional components can be arranged in mutually different orientations. But then the complexity and consequently the cost of a base plate increases accordingly. In addition, these assembly segments are frequently located entirely inside the interior of the tank. Due to the limited surface area of the base plate, there can also be mutual interference among the individual functional components.

Moreover, in the event of a failure of one or more of the functional components of the pre-mounted subassembly of functional components, high repair costs must be expected, since the pre-mounted subassembly of functional components is located in the interior of the tank and consequently must be dismantled entirely.

This shows that the pre-mounted subassemblies of functional components in the prior art allow only a limited design flexibility in the arrangement of the functional components on the tank.

With this as background, it is the object of the present invention to design a tank for a motor vehicle operating fluid of the above-mentioned type, which does not have the disadvantages known from the prior art, and in particular which allows the designer more flexibility in the structural design of such a tank.

To achieve this object, the present invention proposes that the plurality of functional components of the tank be arranged on segments of the tank wall that are positioned at an incline with respect to each other. In this manner it is possible to eliminate a separate functional component group which is pre-mounted to the tank wall and forms a portion thereof. Thus it is possible to arrange the functional components in a simple manner according to their physical operating principles and usages, in differing orientations at mutually inclined tank wall segments and thus to ensure the satisfactory function of each individual functional component. Consequently, the individual functional components are not restricted to being arranged in the limited region of a pre-mounted group of functional components. Thus the functional components can be arranged at a greater distance from each other, so that mutual interference among the individual functional components is reduced or can even be eliminated. Accordingly, the individual functional components can be arranged at any particular location on the mutually inclined tank wall segments. A plurality of functional components will thus be arranged on the tank wall using the plurality of attachment formations. By the additional use of even those tank wall segments which are arranged at an incline to each other, the individual functional components can also be arranged at those points of the tank wall which are tailored to the installation space available in the motor vehicle and to the geometry of the tank. An individualized arrangement of the individual functional components allows a particularly efficient functioning of each of the individual functional components.

The functional components designed for pumping and/or for cleaning and/or for detecting a property and/or for changing a property of the operating fluid can be selected from a group which comprises: A pressure sensor to detect the pressure in the tank, a fill-level sensor to detect the fill level of operating fluid located in the tank, a temperature sensor to detect the temperature of the operating fluid and/or the temperature of the outside environment, a quality sensor to detect the quality of the operating fluid, a heating device for heating the operating fluid, a pumping device for pumping the operating fluid, a filter device for filtering the operating fluid, and a sensor for detecting cavities in the frozen operating fluid located in the interior of the tank.

For example, if a capacitive fill-level sensor and a capacitive quality sensor are provided on the tank wall, then the fill-level sensor will be positioned orthogonal to and the quality sensor parallel to the surface of the operating fluid in the tank. According to the present invention, the mutual interference between the capacitive fill-level sensor and the capacitive quality sensor can be easily eliminated in that the two sensors are arranged on mutually inclined, in particular mutually orthogonal segments of the tank wall.

Selection of a specific type of a particular functional component is subject to little or no restrictions, owing to the flexibility in positioning of the functional components on the tank wall.

The fill-level sensor, for example, can be a capacitive fill-level meter, a fill-level meter using ultrasound, or even another method of physical metering can be used to detect the fill level.

A property of the operating fluid means, for example, such factors as the temperature, the quality, represented, for example, by its chemical composition and/or by a fraction of a substance contained therein, or also the pressure and similar factors.

In the present invention, the concept of “tank wall” is understood to mean that the interior side of the tank wall is adjacent to the tank interior space, and the outer side of the tank wall is adjacent to the outside environment of the tank. Preferably both the interior and the exterior sides of the tank wall are designed as one solid wall structure, without any hollow space located there between.

Usually the tank wall of a tank comprises a top wall, a bottom wall positioned opposite to the top wall, and a side wall which connects the top wall to the bottom wall. The mutually inclined tank wall segments can then be formed by the top wall, the bottom wall and the side wall. The functional components thus can also be arranged at the side wall, and not exclusively at the top and/or bottom wall, so that the available surface area of the tank wall can be used more efficiently.

Preferably a pumping device for pumping operating fluid, in particular form the outlet opening of the tank, is disposed on the tank wall as a functional component. Preferably the pumping device is disposed at the outer side of the tank wall, so as not to reduce the volume of the tank available for the operating fluid present in the tank. The pumping device features a suction side for intake of operating fluid and a pressure side for outlet of operating fluid.

For example, the pumping device can be a gear-type pump, a membrane pump or a hose pump, wherein little or no restrictions are imposed with respect to the selection of the kind of pumping device, because it can be placed anywhere on the tank wall.

It is an additional advantage if a filter device is disposed as one functional component at the tank wall for filtering of operating fluid, in order to clean the operating fluid of impurities. Preferably the filtering device is arranged at the interior side of the tank wall, so that it is flushed by the fluid being filtered, which allows a particularly simple infeed of the operating fluid to the filter device.

According to one preferred embodiment, the infeed of operating fluid to the pumping device takes place such that the filter device is connected to the conveyor device using a first line extending into the interior of the tank for control of the operating fluid. The first line includes an inlet end nearer to the filter device, and an outlet end nearer to the pumping device, wherein the first line is connected by its outlet end to the suction side of the pumping device. In this way the pumping device receives cleaned operating fluid, so that the pumping device is protected against damage due to impurities in the operating fluid. The first line can lead out of the tank and can thus pass through the tank wall, for example, when the conveyance device or another functional component cooperating with the first line is disposed on the outer side of the tank wall.

Like a second line to be described below, the first line also includes a line wall which surrounds a line volume inside the tank interior and is separate from the remaining tank interior volume. The first and the second lines can be designed as multi-part or as a single piece. The first and the second lines can additionally include flexible segments, such as hoses, and/or rigid segments, such as connection tubes at the tank wall. In order to keep the assembly expense low, the connection tubes are preferably designed as integral with the tank wall.

The pumping of operating fluid from the pumping device to the outlet opening of the tank takes place preferably in that the pumping device is connected to the outlet opening of the tank by a second line leading from the tank for control of operating fluid. The second line features an inlet end nearer to the pumping device, and an outlet end nearer to the outlet opening of the tank, wherein at least the outlet end of the second line leads out of the tank—and thus passes through the tank wall, for instance—and its inlet end is connected to the pressure side of the pumping device. In this manner a flow path sealed against the tank interior is created for the pumping of cleaned operating fluid from the tank to the outlet opening, which prevents contamination of any already filtered operating fluid. A pressure sensor can be provided on the second line to detect the pressure of the operating fluid in the second line connected to the pressure side of the pumping device. Preferably this pressure sensor is disposed on the tank wall and thus is located at a segment of the second line leading from the tank.

If the pumping device is disposed at the outer side of the tank wall, then the second line can also lead out from the tank at its outlet end, thus passing through the tank wall. This can be an advantage when there is insufficient space available for placement of a line leading operating fluid away from the pumping device in a region of the outside perimeter of the tank. This method can also be an advantage when the suction side and the pressure side of the pumping device are located near each other, in particular when they are located on the same side of the pumping device. Consequently, with the pumping device located at the outer side of the tank wall, the first line and the second line together lead from the tank for an odd number of times, at least three times.

The outlet opening of the tank can be located at any place on the tank wall. Consequently it is possible to position the outlet opening not at the geodetically lowest point of the tank wall. But preferably the inlet end of the first line, and thus preferably the filter device are arranged at the geodetically lowest point of the tank wall, so that the inlet end of the first line and/or the filter device (when the tank is at least partly filled) is always supplied with operating fluid.

If the filter device has a labyrinthine structure, then anti-slosh baffles can reduce the sloshing noise of the operating fluid. In addition, the pressure of the operating fluid can be held constant due to the integrated labyrinth effect, even at low fill levels.

The tank wall is preferably produced by using an injection molding process. The injection molding process is a particularly versatile method which makes it possible to adapt the structure of the tank to different installation-space conditions in motor vehicles.

In the case of a tank produced by the injection molding method, the wall thickness of the tank wall can be produced thinner than for a tank produced by a blow mold method. Preferably the wall thickness of the tank wall is between 3 mm and 3.5 mm. In this way both material and weight, and thus also costs, can be saved.

The tank wall can be produced from at least two tank shells, preferably from exactly two tank shells, so that the assembly of functional components to be disposed on the tank wall will be simplified in comparison to a tank produced as a single part, due to improved accessibility. For reasons of improved maintenance of the tank, it is preferable to arrange the plurality of functional components on one single tank shell. Preferably the plurality of functional components is disposed on the lower (relative to the install position of the tank in a horizontally standing motor vehicle) tank shell.

In addition, due to the manufacture of the tank using an injection molding process it is possible to equip the tank with one or with a plurality of integral anti-slosh baffles protruding into the interior space of the tank, so that a subsequent assembly of slosh baffles can be omitted. Anti-slosh baffle walls are used to reduce the slosh movements of the operating fluid within the tank and to reduce any resultant sloshing noise.

Also, with regard to a tank produced by means of an injection molding method, by a suitable selection of material for the tank it is possible to produce a supporting component for the tank which is optimized with regard to material and weight, instead of a metal supporting component which is normally used for the tank in the prior art.

The plurality of attachment formations integrated with the tank wall can be produced preferably jointly and simultaneously with the tank wall by an injection molding process. The attachment formations designed integrally with the tank wall can be, for example, contact surfaces for individual functional components, elevations or depressions worked into the tank wall, sealing surfaces or such. The attachment formations designed integral with the tank wall can also include transit openings for individual functional components and/or their supply connectors for electrical power which are also provided in the tank wall. In addition, the attachment formations designed integral with the tank wall can be connector tubes which form segments of the first or of the second line, for example, to connect a flexible segment of the first or of the second line to a pumping device arranged at the outer side of the tank wall.

When equipped with a heating apparatus, the tank can also perform its function reliably even at low ambient temperatures, in particular at ambient temperatures at or below the freezing point of the operating fluid. It is possible that the heating apparatus will provide more heating power to defined locations of the tank wall than at other locations.

The heating apparatus is preferably a flexible heating element which at least partly covers the interior side of the bottom wall. The surface of the flexible heating element in contact with the operating fluid, however, is greater when the heating apparatus essentially completely covers the bottom wall. If a flexible heating element with heating paths disposed between two plastic foils is used, then more heating power can be generated at defined locations of the tank wall, so that the heating paths at the defined locations are placed more closely together than at other locations. Although a heating apparatus designed as flexible heating element is preferred, it is still quite possible that the heating apparatus can have a rigid design.

If the filter device and the heating apparatus overlap on the segment of the tank wall which supports them, then in the event that the ambient temperature falls to or below the freezing temperature of the operating fluid, then the filter device can be protected against damage by activation of the heating apparatus; such damage can be caused by partly or entirely frozen operating fluid present in the interior of the tank. Due to the application of heat from the heating apparatus in the region of the filter device, any frozen operating fluid present there can be melted, or the formation of ice in the region of the filter device can even be prevented. Thus the filter device can always supply a quantity of operating fluid to the conveyance device.

In comparison to a non-insulated tank, a thermal insulating device can reduce the heat loss to the environment, especially in the case when a heating apparatus is activated in the tank interior. Preferably at least one thermal insulating device is arranged at the underside (relative to the install position of the tank) which is most exposed to the outside environment, that is, at the outer side of the bottom wall of the tank. In order to further reduce the heat loss from the tank, an air gap can be provided, at least in sections, between the insulating device and the outer side of the bottom wall of the tank.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The present invention will be explained in greater detail below with reference to the attached drawings.

FIG. 1. shows a rough schematic, cross-sectional view of a motor vehicle tank for operating fluid according to the invention, with functional components arranged on the tank wall.

In FIG. 1, the motor vehicle tank for operating fluid according to the invention is depicted in a roughly schematic form and is designated by the general reference number 10. The tank 10 is depicted in a longitudinal cross section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The tank 10 comprises a tank wall 12 with an interior side 14 and an exterior side 16. The tank wall 12 comprises a tank interior space 18 and has a fill opening 20 for filling of operating fluid into the tank 10, and an outlet opening 22 for drainage of operating fluid from the tank 10. The tank wall 12 is formed from a top wall 24, a bottom wall 26 located opposite the top wall 24, and a side wall 28 which connects the top wall 24 with the bottom wall 26. The tank wall segments of the tank wall 12: Top wall 24, bottom wall 26 and side wall 28, form an outer casing of the tank 10. The interior side 14 of the tank wall 12 seals against the tank interior 18 and the outer side 16 of the tank wall seals against the outside environment 30 of the tank 10.

Furthermore, in the depicted exemplary embodiment, the tank wall 12 produced by an injection molding method features an upper tank shell 12b and a lower tank shell 12a, which are securely joined together when the tank 10 is in the mounted state. The terms “upper” and “lower” pertain to the install position of the final mounted tank 10 in a horizontally standing motor vehicle.

The functional components of the tank 10 on the interior side 14 of the bottom wall 26 are: a fill level sensor 32, a temperature sensor 34, a pressure sensor 44 and a filter device 38. The interior side 14 of the bottom wall 26 is covered essentially entirely by a flexible heating element 40. The flexible heating element 40 and the filter device 38 overlap on their supporting tank wall segment. In the illustrated exemplary embodiment the filter device 38 is attached by screws 42 to the bottom wall, and each of the screws 42 has a self-cutting thread and is screwed into a blind hole formed in the bottom wall 26 and used as attachment formation. The pressure sensor 44 for example, can be used to detect the fill level of the operating fluid in the tank, using a hydrostatic measurement of fill level. The pressure sensor 44 can also be set up to detect a pressure increase in the tank 10 as an indication of a possible plugging of any existing ventilation line, and thus as an indication of a pending loss of functionality.

As additional functional components of the tank 10, a quality sensor 36 and a pump 46 as pumping device are arranged on the side wall 28. The pumping device 46 is secured to the outer side 16 of the side wall 28 by means of a flange 48 and screws 50. Similar to the screws 42 of the filter device 38, each of the screws 50 has a self-cutting thread which is screwed into a blind hole formed in the side wall 28 and acting as attachment formations. The quality sensor 36 is arranged at the interior side 14 of the side wall 28.

Each of the functional components: Fill level sensor 32, temperature sensor 34, quality sensor 36, heating element 40, pressure sensor 44 and pumping device 46, is supplied with power via a connector 32′, 34′, 36′, 40′, 44′ and 46′. In addition, contact surfaces are provided on the tank wall 12 as attachment formations for the fill level sensor 32 and for the filter device 38. The heating element 40 is produced jointly and simultaneously with the tank wall 12 in an injection molding process and is attached to the tank wall 12 with clips. The contact surfaces formed with the tank wall 12 for the fill level sensor 32 and the filter device 38, and also the clips for the heating element 40, are not depicted in FIG. 1. From FIG. 1 it is evident that all functional components are arranged in the lower tank shell 12a. The upper tank shell 12b features anti-slosh baffle walls 52 protruding into the interior 18 of the tank; these baffles are produced simultaneously and jointly with the tank shell.

To insulate the tank 10 against the environment 30, the outer shell 16 of the bottom wall 26 is provided with an insulation element 54. An air gap (not depicted in FIG. 1) can be provided between the outer side 16 of the bottom wall 26 and the insulation element 54.

The pumping device 46 is connected via a first line 56 leading from the tank 10 to a filter device 38 in a fluid-mechanics method. The first line 56 features an inlet end 56a near the filter unit 38, and an outlet end 56b near the pumping device 46. At its outlet end 56b the first line 56 leads out from the tank 10. The outlet end 56b of the first line 56 is connected to the vacuum side of the pumping device 45.

Furthermore, the pumping device 46 is connected via a second line 58 to the outlet opening 22 in the tank wall 12 in a fluid-mechanics method. Similar to the first line 56, the second line 58 also leads out of the tank 10 and features an inlet end 58a near the conveyance device 38, and an outlet end 58b near the outlet opening 22. Both the inlet end 58a and also the outlet end 58b of the second line 58 lead out of the tank 10. The inlet end 58a of the second line 58 is connected to the pressure side of the conveyance device 46. A pressure sensor 45 to detect the pressure in the second line 58 is disposed at the outlet end 58b of the second line 58 at the interior side 14 of the tank wall 12.

Both the first line 56 and also the second line 58 divide the tank interior space 18 into a line volume and a residual tank volume. The first line 56 and the second line 58 comprise connection tubes 57b and 59a and 59b, respectively.

The flow path of the operating fluid is as follows: Operating fluid filtered in the filter device 38 flows into the inlet end 56a of the first line 56 connected to the filter unit 38, and from there to the outlet end 58b of the first line 56 connected to the suction side of the conveyance device 46. The operating fluid pulled in by the conveyance device 46 is then pumped from the suction side to the pressure side of the conveyance device 46 and flows into the inlet end 58a of the second line 58. The conveyance device 46 pumps the operating fluid to the outlet end 58b of the second line 58 connected to the outlet opening 22, and finally through the outlet opening 22 of the tank 10.

The invention provides a motor vehicle tank for operating fluid, with functional components arranged thereon, wherein the functional components can be arranged on the tank with considerable design flexibility, in that the functional components are arranged on segments of the tank wall which are disposed at an incline to each other.

Claims

1. Tank for motor vehicle operating fluid for accommodating of a fluid, comprising: wherein the plurality of functional components of the tank are disposed on segments of the tank wall which are disposed at an incline to each other.

a tank wall forming an outermost casing of the tank, the tank wall having an inner side bordering a tank interior, and having an outer side bordering the external environment of the tank,

a fill opening passing through the tank wall for inlet of the operating fluid into the tank,

an outlet opening passing through the tank wall for outlet of the operating fluid from the tank,

a plurality of functional components, wherein the functional components are designed for pumping and/or for cleaning and/or for detecting a property and/or for changing a property of the operating fluid, and

a plurality of attachment formations designed as being integral with the tank wall for the positioning of a plurality of functional components on the tank wall,

2. The tank according to claim 1, wherein the tank wall comprises a top wall, a bottom wall opposite to the top wall, and a side wall connecting the top wall to the bottom wall, wherein the top wall, the bottom wall and the side wall form tank wall segments arranged at an incline to each other.

3. The tank according to claim 1, wherein at the tank wall, preferably at the outer side of the tank wall, as one functional component a pumping device is arranged for pumping of operating fluid, wherein the pumping device features a suction side for the intake of operating fluid and a pressure side for the ejection of operating fluid.

4. The tank according to claim 1, wherein at the tank wall, as one functional component a filter device is arranged for filtering of operating fluid.

5. The tank according to claim 1,

wherein the filter device is connected to the pumping device by a first line extending into the interior of the tank for guiding the operating fluid, wherein the first line features an inlet end nearer to the filter device, and an outlet end nearer to the pumping device, wherein the first line with its outlet end is connected to the suction side of the pumping device.

6. The tank according to claim 5, wherein the pumping device is connected to the outlet opening of the tank by means of a second line for guiding operating fluid leading out of the tank, wherein the second line features an inlet end nearer to the pumping device nearer to the outlet opening of the tank, wherein the second line at least at its outlet end leads out of the tank and its inlet end is connected to the pressure side of the pumping device.

7. The tank according to claim 1, wherein the outlet opening of the tank is not arranged at the geodetically lowest point of the tank wall.

8. The tank according to claim 1,

wherein the filter device has a labyrinthine structure.

9. The tank according to claim 1, wherein the tank wall is produced by an injection molding process.

10. The tank according to claim 9,

wherein the tank wall is formed from at least two tank shells.

11. The tank according to claim 9,

wherein at least one anti-slosh baffle protruding into the tank interior are designed as being integrated with the tank wall.

12. The tank according to claim 9, wherein the plurality of attachment formations designed integrally with the tank wall are produced jointly and simultaneously with the tank wall in an injection molding process.

13. The tank according claim 1,

wherein at the tank wall, as a functional component a heating device is arranged as a flexible heating element, which covers the inner side of the bottom wall at least partially, and most preferably covers it essentially entirely.

14. The tank according to claim 13,

wherein the filter device and the heating device overlap at the segment of the tank wall supporting them.

15. The tank according to claim 1,

wherein an insulating unit is arranged at the outer side of at least one of the tank wall segments.

16. The tank according to claim 1, wherein the plurality of functional components is selected from a group which comprises:

a pressure sensor to detect the pressure in the tank,

a fill-level sensor to detect the fill level of operating fluid located in the tank

a temperature sensor to detect the temperature of operating fluid and/or the temperature of the outside environment,

a quality sensor to detect the quality of the operating fluid,

a heating device for heating of the operating fluid,

a pumping device for pumping of the operating fluid,

a filter device for filtering of the operating fluid, and

a sensor for detecting of cavities in frozen operating fluid located in the interior of the tank.

17. The tank according to claim 1, wherein at the inner side of the tank wall, as one functional component a filter device (38) is arranged for filtering of operating fluid.

18. The tank according to claim 6, wherein the second line also at its inlet end leads out of the tank when there is a pumping device arranged on the outer side of the tank wall.

19. The tank according to claim 7, wherein the inlet end of the first line and/or the filter device is arranged at the geodetically lowest point of the tank wall.

20. The tank according to claim 9, wherein preferably the tank wall has a thickness of 3 mm to 3.5 mm.

21. The tank according to claim 1, wherein the tank wall is formed from exactly two tank shells.

22. The tank according to claim 10, wherein the plurality of functional components is arranged on a single one of the tank shells.

23. The tank according claim 1, wherein at the tank wall, as a functional component a heating device is arranged as a flexible heating element, which covers essentially entirely the inner side of the bottom wall.

24. The tank according to claim 1, wherein an insulating unit is arranged at the outer side of at least one of the tank wall segments at least on the bottom wall.