WO2008064848A1 - Method for producing a utility vehicle tank - Google Patents

Abstract

In a method for producing a utility vehicle tank (1) from plastic, it is provided to produce two closed containers from one plastic, which containers form end segments (2) of the tank and have in each case two base surfaces, which run transversely with respect to the tank longitudinal direction, and an encircling wall surface (4) which forms the tank wall. In each case one of the base surfaces forms a tank end wall. The other base surface is offset with respect to the end-side end of the associated wall surface, such that an encircling projecting length (5) is formed. One of the two end segments has an encircling projecting length with a reduced diameter, such that the projecting lengths can be inserted one into the other. Alternatively, it is possible for at least one further module (6) to be inserted between the end segments, which further module (6) is produced as a closed container from a plastic and has in each case two base surfaces, which run with respect to the tank longitudinal direction, and an encircling wall face which forms the tank wall. Here, the two base surfaces of the further module are offset with respect to the associated end-side end of the wall surface such that an encircling projecting length is formed which is suitable to be plugged together with an encircling projecting length of an adjoining end segment or of a further module. The contact surfaces, provided for connection, of two projecting lengths are simultaneously fused by means of a welding process.

Description

Method for producing a commercial vehicle tank

The invention relates to a method for producing a commercial vehicle tank made of plastic.

The invention also relates to a plastic tank for commercial vehicles produced by the method.

Plastic fuel tanks are already known from the general state of the art. These offer the advantage that plastic is a relatively lightweight material compared to conventional steel, which can also be easily, quickly and inexpensively machined. Another advantage of plastic is that it offers better design possibilities compared to metals.

With regard to the general structure of fuel tanks made of steel or aluminum, reference is made to DE 203 14 249.

From DE 44 42 780 C2, a fuel tank for aircraft is known, which is assembled from a plurality of identical or approximately identical pot-like elements. Each of these elements has a transverse to the tank longitudinal direction oriented bottom surface and a circumferential, immediately forming the tank wall wall surface. The bottom surfaces of the elements form the structurally stiffening bulkheads in the tank interior and the two tank end walls. The in-tank interior bottom surfaces of the elements are either provided with openings for the fuel flow or tight. The elements can be produced in plastic and / or metal construction. In one embodiment of the plastic elements is provided that the elements are glued together in the joint area. In an embodiment of metal is provided that the elements through Gluing, riveting, screwing, welding or combinations of these joining methods are connected.

In the field of passenger cars, in which tank volumes of 50 to 100 liters are common, an embodiment of the plastic tanks is known in many ways. In theory, as can be seen for example from DE 44 42 780 C2, considerations regarding the formation of large-volume fuel tanks made of plastic for aircraft can be found. Such considerations are also occasionally found in the manufacture of large capacity commercial vehicle tanks which generally contain from 300 to 1500 liters of fuel. However, in practice there are still no solutions as to how a large-volume commercial vehicle tank made of plastic could actually be mass-produced. Such a commercial vehicle tank would have to be easy and inexpensive to produce. On the other hand, such a commercial vehicle tank would have to meet high crash requirements and, in particular, be able to withstand the vibrations and resonances arising in the continuous operation of a commercial vehicle at the connection points. For commercial vehicles, especially for commercial vehicles that are in heavy terrain in use, a high stability of the commercial vehicle tank is required.

In the context of cost-effective production, it is also desirable to produce commercial vehicle tanks with different lengths as standardized as possible.

The present invention is therefore based on the object to provide a method for producing a commercial vehicle tank made of plastic, which allows the production of a commercial vehicle tank with a high stability and fatigue strength in a simple and cost-effective manner. This object is achieved by claim 1.

For the cost-effective and simple production of a stable commercial vehicle tank, it has proven to be advantageous if initially two closed containers are produced from a plastic, which are to form end segments of the tank. This can be done for example by a known Rotationsssinterverfahren. The closed containers to be produced should each have two transverse to the tank longitudinal direction extending bottom surfaces and a circumferential, the tank wall forming wall surface. In this case, one of the bottom surfaces should form a tank end wall and the other bottom surface should be offset from the front end of the associated wall surface, so that a projection is formed. This can be z. Example, take place in that the bottom surface is set back relative to the wall surface in the direction of the container interior, so that a part of the wall surface forms a circumferential projection. The production of such a closed container made of plastic presents no problems with the known prior art. In addition to rotational sintering, a blowing method or a rapid prototyping method could be used for this purpose.

From the general state of the art further methods for producing hollow plastic bodies are known.

According to the invention is provided according to feature 1.2.1, that one of the two end segments has a circumferential projection with a reduced diameter, so that the circumferential projections can be plugged into each other or. According to the invention, the contact surfaces of the two associated protrusions provided for connection should be melted simultaneously by means of a welding process. It is advantageous when the contact surfaces are melted before mating.

The fact that the containers are formed with supernatants, results in a particularly stable connection between the two containers. The two containers have anyway, since they are each formed as a closed container in one piece, a high stability. The stability of the commercial vehicle tank produced thereafter is further increased by the fact that the supernatants are inserted into each other, which can already result in a certain mechanical strength and also a large contact area is provided. A high strength of the compound results from the fact that a welding method is used in which the contact points are melted simultaneously.

The solution according to the invention not only offers high stability, but is also easy and inexpensive to produce, since both the production of closed containers, for example in the rotation sintering process, as well as the connection of the two containers on their supernatants by means of a welding process is simple and inexpensive feasible.

According to the invention, it is further provided that a commercial vehicle tank can also be created by using at least one further module between the end segments. The module can be made as a closed container made of a plastic and in each case have two transverse to the tank longitudinal direction bottom surfaces and a circumferential, the tank wall forming wall surface. It is provided that the two bottom surfaces are offset from the associated front end of the wall surface, so that a circumferential projection is formed. This can be z. B. be achieved by the Floor surface are set back relative to the wall surface in the direction of the container interior, so that a part of the wall surface forms a circumferential projection. Such a container can be easily and inexpensively manufactured by the methods already described. According to the invention, it should further be provided that the supernatant (for example by means of a taper) is suitable for being plugged together with a circumferential projection of an adjacent end segment or of a further module. The contact surfaces of two associated projections provided for the connection are melted at the same time, preferably before being plugged together, by means of a welding process.

This solution according to the invention makes it possible in a simple manner to produce commercial vehicle tanks of different lengths. For this purpose, only a correspondingly long module or optionally several modules must be used only between the two end segments, each forming a tank end wall. For example, a commercial vehicle tank with a length of 1,100 mm may have two end segments, each having a length of 300 mm, and a module having a length of 500 mm. A commercial vehicle tank with a total length of 1,300 mm can fall back on the same end segments, with the difference that the module to be interposed therebetween has a length of 700 mm. In a particularly small commercial vehicle tank, for example, should only have a length of 600 mm, can be completely dispensed with the additional module. In this case, the containers, as provided in accordance with feature 1.2.1, are connected directly in the manner described. Features 1.2.1 and 1.2.2 are alternatives to each other in order to produce a wide variety of commercial vehicle tanks. A particularly suitable commercial vehicle tank results from the method according to claim 24.

The connection between the containers and the modules is independent of their size in each case by the same connection technique, namely a welding method in which the contact surfaces of two supernatants are melted simultaneously. A heating-mirror welding process has proven to be particularly suitable for this purpose. For simultaneous welding of two contact surfaces, however, from the general state of the art also other welding processes, for. As ultrasonic welding and laser welding, known.

In a structural embodiment of the invention, an annular gap for receiving molten plastic can be provided between the front end of an externally plugged overhang of a module or end segment and the front end of the adjacent module or end segment. Such a gap can be formed, for example, by the fact that the supernatant to be placed on the outside is pushed onto the adjoining end segment or the adjacent module only so far that a small gap, for example of 1 to 3 mm, remains in the region in which the taper the supernatant of the other module or end segment is located.

An embodiment of such a gap has been found to be advantageous in order to avoid that melted plastic exits through the welding process uncontrolled.

A particularly good connection between the individual modules or end segments is obtained if the supernatants have a length in the tank longitudinal direction of 10 to 200 mm, preferably 30 to 50 mm. It is advantageous if the bottom surfaces are optionally provided with openings for the fuel flow. Alternatively or additionally, the floor surfaces can optionally also be completely removed. By completely removing the floor surfaces or providing the bottom surfaces with openings, it is possible to provide a commercial vehicle tank with a large and contiguous tank interior or filling space. Insofar as the bottom surfaces are not removed or no openings are introduced, it is achieved that the utility vehicle tank has two or more separate filling spaces. It is particularly advantageous if one of the filling spaces for receiving a fuel and not for receiving a fuel is formed. The fuel may preferably be a urea or a urea solution. Inasmuch as the commercial vehicle tank has two container interior spaces, it is advantageous if the smaller container interior is designed to accommodate the fuel solution or the urea or the urea solution. In a particularly simple manner, this can be achieved if one of the end segments remains as a closed container, ie that its bottom surface is not removed and is not provided with openings.

It can also be provided that the smaller filling space is designed to accommodate an alternative fuel.

Advantageous developments and refinements of the invention will become apparent from the other claims.

An exemplary embodiment of the invention is shown in principle below with reference to the drawing. It shows :

FIG. 1a shows a longitudinal section through a commercial vehicle tank produced according to the method according to the invention before the segments are assembled; FIG.

FIG. 1b shows a longitudinal section through a commercial vehicle tank produced by the method according to the invention, after assembly of the segments; FIG.

2 shows a cross section through a commercial vehicle tank produced by the method according to the invention;

3 shows a cross section through a commercial vehicle tank in an area in which two segments are plugged together, wherein the bottom surface separating the segments is provided with openings;

4 shows a longitudinal section through a commercial vehicle tank according to FIG. 1 with an extended intermediate segment in an embodiment for receiving a fuel and a fuel;

5 shows a basic procedure for producing a commercial vehicle tank;

Fig. 6 is a schematic representation of the melting of the segments; and

Fig. 7 is a side view of a commercial vehicle tank according to the invention. Commercial vehicle tanks and methods for producing commercial vehicle tanks are well known from the general state of the art, for which reason only the features essential to the invention will be described in more detail below.

The inventive method is particularly suitable for the production of large-volume commercial vehicle tanks made of plastic with a volume of 300 to 1,500 liters.

In a special way, the inventive method for producing a commercial vehicle tank with two separate filling chambers, which accommodate two different media. In this case, a filling space - preferably the larger - for receiving a fuel, such as diesel, and the other filling space for receiving a fuel, such as a urea or a urea solution may be formed. The smaller filling space can also serve to accommodate alternative fuels.

To improve the effectiveness of catalysts, it is advantageous to inject small amounts of urea or a urea solution. The solution according to the invention now enables easy transport of the urea.

Figures 1 to 3 show a commercial vehicle tank 1, which is produced by the method according to the invention. Here, it is initially provided that two closed containers are produced from a plastic, which form end segments 2 of the commercial vehicle tank 1. The closed containers or the end segments 2 each have two transverse to the tank longitudinal direction extending bottom surfaces 3 and a circumferential, the tank wall forming wall surface 4. In each case one of the bottom surfaces 3 of the end segments 2 forms a tank end wall 3a. The other Floor surface 3 is offset from the front end of the associated wall surface 4, so that a circumferential projection 5 is formed.

According to one of the embodiments of the invention can be provided that one of the two end segments 2 has a circumferential projection 5 with a reduced diameter or cross section, so that the circumferential projections 5 of the two end segments 2 can be inserted into one another. In the embodiment, this is not shown. Shown in the exemplary embodiment is the second possibility according to the invention, namely that at least one further module 6 is inserted between the end segments 2.

According to the exemplary embodiments illustrated in FIGS. 1 to 4, it is provided that two modules 6, 6a are used. The modules βa, βb are each made as a closed container made of a plastic. The modules 6a, 6b each have two transverse to the tank longitudinal direction extending bottom surfaces 3 and a circumferential, the tank wall forming wall surface 4. The bottom surfaces 3 are offset from the associated front ends of the wall surfaces 4, so that a supernatant 5 is formed, which is adapted to be mated with a circumferential projection 5 of an adjacent end segment 2 or other modules 6a, 6b.

The module 6a forms the main segment of the commercial vehicle tank 1, while the module 6b forms an intermediate segment.

In the exemplary embodiments, the circumferential projections 5 of the end segments 2 are formed by the associated bottom surface 3 being opposite the wall surface 4 in the direction of the inner surface. space of the end segment 2 is set back. As a result, part of the wall surface 4 forms the circumferential overhang 5.

The one end segment 2 facing supernatant 5 of the main segment 6a may, for. Example, be formed by the fact that the actual bottom surface 3 of the main segment 6a is set back in the direction of the interior of the main segment 6a, so that a part of the wall surface forms the supernatant 5. The supernatant 5 may have a taper relative to the tank wall or the wall surface 4, so that the supernatant 5 of the main segment 6a has a reduced diameter. The supernatant 5 can thereby be mated with the supernatant 5 of the associated end segment 2. Alternatively, the supernatant 5 of the main segment 6a can also be formed by the bottom surface 3 protruding in relation to the wall surface 4 in the direction of the end segment 2. However, the supernatant of the bottom surface 3 should not be over the entire surface, but so that a supernatant 5 of the end segment 2 can be plugged.

The main segment 6a may analogously have at its second bottom surface 3, a further supernatant 5, which is mating with a projection 5 of the intermediate segment 6b. Again analogously thereto, the intermediate segment 6b may be provided on its bottom surface 3 facing away from the main segment 6a with a suitable projection 5 which may be fitted together with a projection 5 of the second end segment 2.

In principle, it is possible that the commercial vehicle tank 1 also has more or fewer modules 6a, 6b.

FIG. 2 shows a cross section through the main segment 6 a of the utility vehicle tank 1. 3 shows a cross section through the utility vehicle tank 1 in a region in which the main segment 6a is fitted together with the intermediate segment 6b. The separating bottom surface is provided with openings 7, which allow a fuel flow. This creates a large common filling space of the main segment 6a and the intermediate segment 6b.

Fig. 4 shows a comparison with Fig. 1 extended commercial vehicle tank, the extension is based essentially on an extended configuration of the intermediate segment 6b. The end segments 2 and the main segment 6a may have a standardized length. This makes it possible that commercial vehicle tanks with different lengths can be produced in a particularly simple and cost-effective manner, since most segments 2, 6a are not affected by the change in length.

A simple change in length can also be realized by using several intermediate segments.

FIG. 4 shows yet another modification with respect to FIG. 1. According to FIG. 4, it is provided that an end segment 2 is designed to receive a fuel (or alternative fuels), namely a urea or a urea solution. The trained for receiving the fuel end segment is provided in Fig. 4 with the reference numeral 2a. The male fuel can, for. As a designated as AD-BLUE fuel. The utility vehicle tank 1 shown in Fig. 4 thus has two separate filling spaces. It is provided that the main filling space is formed by the main segment 6a, the intermediate segment 6b and the end segment 2. This main filling space is preferably provided for receiving fuel, in particular diesel. The smaller filling space is formed by the end segment 2a. The production of two Separate tank interior spaces or filling spaces can be achieved in a simple manner in that the bottom surface 3 of the end segment 2a and / or the facing bottom surface 3 of the intermediate segment 6b has neither openings 7, nor is removed. On the other hand, the bottom surfaces 3 which separate the end segment 2 from the main segment 6a and separate the main segment 6a from the intermediate segment 6b may be optionally provided with openings 7 or completely removed.

In the context of a particularly effective production of a commercial vehicle tank, it has proven to be suitable if all the required functional elements 8 are arranged in an end segment 2 or a module 6. In the exemplary embodiment, it is provided according to FIG. 1 that all functional elements 8 are cast into the main segment 6a. In this case, individual functional elements 8, z. B. filter systems before welding the segments 2, 6a, 6b are arranged inside each other in the segments. This is also provided according to FIG. 4, wherein the end segment 2a provided for receiving the operating substance is likewise provided with the necessary functional elements 8.

In the functional elements 8, it may be z. B. to filter, filler neck, level sensor, water separator or the like.

In the exemplary embodiment it is provided that the end segments 2 have a length of 200 to 500 mm, preferably 300 to 400 mm. In the exemplary embodiment, it is further provided that the main segment 6a has a length of 300 to 900 mm, preferably 500 to 700 mm. The intermediate segment 6b can have any suitable length, so that the commercial vehicle tank 1 has the desired overall length. The supernatants 5 may have a length in the tank longitudinal direction of 10 to 200 mm, preferably 30 to 50 mm.

5 shows a basic sequence of the method for producing a commercial vehicle tank 1. First, it is provided that, for example by rotational sintering, the individual segments 2, 6a, 6b are produced in the form of closed containers (FIG. 5a). The containers already have the supernatants 5. Subsequently, a post-processing, in particular a processing of the bottom surfaces 3 of the produced segments 2, 6a, 6b. It can be provided that the bottom surfaces 3 are cut, perforated or otherwise processed (Fig. 5b).

As the next method step, it is provided that the contact surfaces 9 of the projections 5 shown in more detail in FIG. 6 are warmed up, joined and welded (FIG. 5 c). This creates a finished plastic tank (Fig. 5d).

The contact surfaces 9 of two projections 5 are melted simultaneously by means of a welding process before the supernatants 5 are inserted into one another. It is particularly advantageous that, as shown in Fig. 6, not only the supernatants 5 are welded, but also that the frontally abutting ends of the wall surfaces 4 are welded accordingly. In Fig. 6, a heating element 10 for carrying out the welding process is shown in principle. In the exemplary embodiment, it is provided that the welding method is a heating-mirror welding method, which has been found to be particularly suitable for implementation.

The commercial vehicle tank shown in Fig. 7 has various variants, which can each be realized individually or in any combination with each other. The commercial vehicle tank shown in Fig. 7 substantially corresponds to the commercial vehicle tank according to Fig. 5d, but can also be made in other ways. The commercial vehicle tanks 1 shown in FIG. 7 have a module 6b, which is provided with treads 11 or ascent aids. It is provided that the module 6b is already formed in the manufacture of the plastic with treads 11. In a manner not shown may also be provided that another module, such as the module 6a or one of the end segments 2, is provided with treads.

According to the invention, it can further be provided that, in the case of at least one end segment 2 and / or at least one module 6, a partial material thickening 12 is produced and / or fastening elements 13 are integrated or sintered.

In the exemplary embodiment illustrated in FIG. 7, a plurality of material thickenings 12 or material thickenings are formed on the upper side of the commercial vehicle tank 1. At these material thickenings 12 attachments 14 14 can be attached directly or via fasteners. Alternatively or additionally, the fastening elements 13 can also be integrated or sintered directly during the production of the modules 6 or the end segments 2. This is represented in principle in FIG. 7 on the underside of the utility vehicle tank 1.

The attachments 14 may be formed differently. It is conceivable, for example, the training as catwalk, underrun protection or as side trim parts. In Fig. 7 it is provided that on the thickened material 12 and attached thereto fasteners 13, a catwalk 14a is mounted on the truck tank 1. Furthermore, at the terseite of the commercial vehicle tank 1 provided that using the sintered fastening elements 13, an underrun protection 14 b is attached. In a similar manner, sintered fastening elements 13 and / or material thickenings 12 can also be used to attach other attachment parts 14, for example side trim parts, to the outside of the utility vehicle tank 1.

In a manner not shown, the plastic used for the production of the commercial vehicle tank 1, in particular the modules 6 and / or the end segments 2, are provided with a fiber reinforcement. The fiber reinforcement may preferably be formed as a net or net-shaped. Further, the fiber reinforcement may preferably be formed with or comprise carbon fibers or plastic fibers. The carbon fibers may preferably be injected into the plastic.

Alternatively or additionally, it is also possible to form the fiber reinforcement in the form of a metal net and to introduce it into the tool for producing the end segments 2 or the modules 6 before the plastic is introduced.

In a manner not shown, the modules 6 and / or the end segments 2 can be produced with a contour-supporting or stiffening surface structure. A special surface structure for reinforcing the structure may have, for example, grooves and / or honeycombs and / or thickenings and / or recesses and / or beads or the like or be formed with these. Thus, a stiffening or reinforcement of the end segments 2 and / or the modules 6 and thus of the commercial vehicle tank 1 can be achieved in a simple manner. The elements shown in Fig. 7 can also be used individually or arbitrarily combined with each other in the other embodiments.

It is also advantageous in the case of the solution according to the invention that the individual segments, in particular the end segments 2, can have an almost arbitrary shape. Among other things, a non-rotationally symmetrical or non-linear shape may be advantageous, which may be adapted to the structural conditions of the commercial vehicle z. B. the frame or a narrowing due to a wheel well is adjusted. A non-linear shape is particularly suitable for the end segment 2a for receiving ureas.

Claims

claims 1. A method for producing a commercial vehicle tank made of plastic, according to which two closed containers are produced from a plastic, which form end segments (2) of the tank and two transverse to the tank longitudinal direction bottom surfaces (3) and a circumferential, the tank wall forming wall surface (4). exhibit, 1.1, according to which one of the bottom surfaces (3) forms a tank end wall (3a) and the other bottom surface (3) is offset relative to the front end of the associated wall surface (4), so that a circumferential projection (5) is formed; 1.2.1 according to which one of the two end segments (2) has a circumferential projection with a reduced diameter, so that the projections (5) can be inserted into one another; or 1.2.2 between the end segments (2) at least one further module (6) is used, which is made as a closed container made of a plastic and two transverse to the tank longitudinal direction bottom surfaces (3) and a circumferential, the tank wall forming wall surface (4) according to which the two bottom surfaces (3) are offset relative to the associated front end of the wall surface (4), so that a peripheral projection (5) is formed, which is suitable with a circumferential projection (5) of an adjacent end segment (2). or another module (6) to be put together; 1.3 whereafter the contact surface (9) of two projections (5) provided for the connection is simultaneously melted by means of a welding process. 2. The method according to claim 1, characterized in that the welding process is a heating mirror welding process. 3. The method according to claim 1 or 2, characterized in that the contact surfaces (9) are softened or melted before the respective supernatants (5) are pushed together. 4. The method of claim 1, 2 or 3, as you rchge ke nn zeic hn et, that between the front end of an externally plugged supernatant (5) of a module (6) or end segment (2) and the front end of the adjacent module ( 6) or Endsegments (2) a circumferential gap for receiving molten plastic is provided. 5. The method according to any one of claims 1 to 4, d a d u r c h e c e n e c e in that the supernatants (5) have a length in the tank longitudinal direction of 10 to 200 mm, preferably 30 to 50 mm. 6. Method according to one of claims 1 to 5, characterized in that the bottom surfaces (3) are optionally provided with openings (7) for the fuel flow. 7. Method according to one of claims 1 to 6, characterized in that the bottom surfaces (3) are optionally completely removed. 8. The method according to any one of claims 1 to 7, characterized in that at least two separate tank interior spaces are formed, wherein a tank interior for receiving a fuel, in particular a urea or a urea solution, is provided. 9. The method according to claim 8, characterized in that an end segment (2) is formed for receiving an operating substance, in particular a urea or a urea solution. 10. Method according to one of claims 1 to 8, characterized in that an end segment (2) or module (6) is provided with functional elements (8). 11. The method according to claim 10, wherein the functional elements (8) are poured into the end segment (2) or the module (6) in the form of filters, filler neck, level sensor, water separator or the like. 12. The method according to any one of claims 1 to 11, d a d u r c h e c e n e c e in that the end segments (2) in a length of 200 to 500 mm, preferably 300 to 400 mm, are formed. 13. Method according to claim 1, wherein the modules (6) are formed with a length of 300 to 900 mm, preferably 500 to 700 mm. 14. The method according to any one of claims 1 to 13, characterized in that the closed containers, from which the end segments (2) and / or modules (6) are formed, are produced by rotational sintering. 15. The method according to any one of claims 1 to 14, characterized in that two end segments (2) and at least two modules (6) are used, wherein a module as the main segment (6a) and a module as an intermediate segment (6b) is formed, after which the End segments (2) and the main segment (6a) have a standardized length and for the production of tanks of different lengths only the length of the intermediate segment or the number (6b) is varied. 16. Method according to one of claims 1 to 15, characterized in that an end segment (2) and / or a module (6) is provided with treads (11). 17. The method according to any one of claims 1 to 16, characterized in that at least one end segment (2) and / or at least one module (6) a partial material thickening (12) is generated and / or fasteners (13) integrated or sintered , 18. The method according to claim 17, characterized in that mounting parts (14) are attached to the partial material thickenings (12) and / or the fastening elements (13). 19. The method according to any one of claims 1 to 18, characterized in that the plastic or the end segments (2) and / or the modules (6) are provided with a fiber reinforcement. 20. Method according to claim 19, characterized in that the fiber reinforcement is formed as a net. 21. The method of claim 19 or 20, wherein a fiber reinforcement is formed with carbon fibers. 22. The method according to claim 1, wherein the modules and / or the end segments are produced with a contour-supporting surface structure. 23. The method according to claim 22, wherein a surface structure is formed with grooves and / or honeycombs and / or thickenings and / or recesses and / or beads. 24. Commercial vehicle tank, produced according to one of claims 1 to 23.