Liquid container for a motor vehicle and method for producing a liquid container

Abstract

A liquid container for a motor vehicle, comprising a storage volume for storing a liquid and comprising at least one shell, which at least partially delimits the storage volume, wherein the shell has been produced at least partially in an injection molding process, the shell has a barrier film, the shell has a reinforcing element, which is formed at least partially or completely of a thermoplastic fiber-reinforced composite material, the shell has a single-part or multi-part support structure, which is formed at least partially or completely of an injection-molded material, the barrier film is integrally bonded to the reinforcing element, and the barrier film and the reinforcing element are each integrally bonded to the support structure.

Claims

1. A method for producing a liquid container, comprising: providing a barrier film; providing a reinforcing element, which is formed at least partially or completely of a thermoplastic fiber-reinforced composite material; integrally and directly bonding the barrier film to the reinforcing element; injection-molding a support structure, the support structure being integrally and directly bonded to the reinforcing element and the support structure being integrally and directly bonded to the barrier film, the barrier film, the reinforcing element and the support structure being distinct components of the liquid container, and the support structure at least partially covers a face of the reinforcing element which faces away from the barrier film.

2. The method according to claim 1, wherein providing the barrier film comprises the following steps: thermoforming the barrier film; positioning and fixing the barrier film in an injection-molding tool; and the barrier film being thermoformed before the barrier film is positioned in the injection-molding tool and/or after the barrier film is positioned in the injection-molding tool.

3. The method according to claim 2, wherein: the barrier film is positioned in the injection-molding tool using a roll-to-roll feed-in; and/or the barrier film is fixed to the injection-molding tool using a holding frame; and/or the barrier film is fixed and thermoformed by generating a negative pressure in the injection-molding tool.

4. The method according to claim 1, wherein integrally and directly bonding the barrier film to the reinforcing element comprises the following steps: heating the reinforcing element to a temperature greater than or equal to a melting point of a plastics material matrix of the reinforcing element; the reinforcing element being heated before and/or during the provision of the barrier film; moving the reinforcing element into a region between a first tool half that receives the barrier film and a second tool half, the reinforcing element being moved between the tool halves during or after the heating; and integrally and directly bonding the reinforcing element to the barrier film by pressing the heated reinforcing element against a face of the barrier film remote from the first tool half.

5. The method according to claim 4, wherein: when the heated reinforcing element is pressed on, the barrier film has a residual heat from preceding thermoforming of the barrier film; and/or the barrier film is heated by a heating device before the heated reinforcing element is pressed on.

6. The method according to claim 4, wherein: the second tool half is a nozzle-side tool half.

7. The method according to claim 4, wherein: the support structure completely covers the face of the reinforcing element which faces away from the barrier film.

8. A liquid container for a motor vehicle, comprising: a storage volume for storing a liquid; and at least one shell, which at least partially delimits the storage volume, wherein the shell has been produced at least partially in an injection molding process, the shell has a barrier film, the shell has a reinforcing element, which is formed at least partially or completely of a thermoplastic fiber-reinforced composite material, the shell has a single-part or multi-part support structure, which is formed at least partially or completely of an injection-molded material, the barrier film, the reinforcing element and the support structure being distinct components of the shell, the barrier film is integrally and directly bonded to the reinforcing element, the barrier film and the reinforcing element are each integrally and directly bonded to the support structure, and the support structure at least partially covers a face of the reinforcing element which faces away from the barrier film.

9. The liquid container according to claim 8, wherein: the reinforcing element is arranged, at least in portions or completely, between the barrier film and the support structure; and/or the barrier film partially or completely covers a face of the reinforcing element.

10. The liquid container according to claim 8, wherein: the shell is a first half-shell, which together with a second half-shell delimits the storage volume; and the second half-shell has a wall construction comprising a barrier film, a reinforcing element and a support structure.

11. The liquid container according to claim 8, wherein: the reinforcing element has reinforcing fibers, which are embedded in a thermoplastic plastics material matrix, the reinforcing fibers comprising glass fibers and/or aramid fibers and/or carbon fibers; and/or the reinforcing element has reinforcing fibers that are embedded in a thermoplastic plastics material matrix, the plastics material matrix comprising polyamide, polyolefin, polyurethane, polyphenylene sulfide; and/or the reinforcing element comprises a fiber-reinforced composite plastics material reinforced with long fibers; and/or with the support structure comprising high density polyethylene (HDPE) or a polyamide modified to be shock-resistant; and/or the reinforcing element comprises an organic sheet; and/or the reinforcing element comprises a unidirectionally reinforced strip.

12. The liquid container according to claim 8, wherein: the support structure comprises the material nylon 6 (PA6), the reinforcing element comprises glass-fiber-reinforced PA6, and the barrier film has cover layers that comprise PA6, and the cover layers of the barrier film enclose a central layer of the barrier film, the central layer of the barrier film comprising ethylene vinyl alcohol (EVOH); or the support structure comprises material HDPE, the reinforcing element comprises glass-fiber-reinforced HDPE, and the barrier film has cover layers that comprise HDPE, the cover layers of the barrier film enclosing a central layer of the barrier film, the central layer comprising EVOH, and an adhesion promotor layer of the barrier film being arranged between the central layer and an associated cover layer in each case, the adhesion promotor layers each comprising linear low density polyethylene (LLDPE); or the support structure comprises the material HDPE, the reinforcing element comprises glass-fiber-reinforced PA6, and the barrier film has cover layers that comprise HDPE, the cover layers of the barrier film enclosing a central layer of the barrier film, the central layer comprising EVOH, and an adhesion promotor layer of the barrier film being arranged between the central layer and an associated cover layer in each case, the adhesion promotor layers each comprising LLDPE, and an adhesion promotor layer being provided between the reinforcing element and the barrier film and/or the reinforcing element and the support structure, the adhesion promotor layer comprising low density polyethylene (LDPE) or LLDPE.

13. The liquid container according to claim 8, wherein: the reinforcing element is a substantially planar plate, which is part of a base-side or cover-side wall delimiting the storage volume; the support structure forming a transition, curved at least in portions, from the base-side or cover-side wall to a side wall delimiting the storage volume; or the reinforcing element is curved in one, two or three directions in space, in the manner of a free-form surface, and is part of a base-side or cover-side wall delimiting the storage volume.

14. The liquid container according to claim 8, wherein: the support structure completely covers the face of the reinforcing element which faces away from the barrier film.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, the invention is described in greater detail by way of drawings, which illustrate an embodiment and in which, in each case schematically:

(2) FIG. 1 is a cross section of a liquid container according to the invention;

(3) FIG. 2 is a cross section of a further liquid container according to the invention;

(4) FIG. 3 shows a method step of the method according to the invention;

(5) FIG. 4 shows a further method step of the method according to the invention;

(6) FIG. 5 shows a further method step of the method according to the invention;

(7) FIG. 6 shows a further method step of the method according to the invention.

DETAILED DESCRIPTION

(8) FIG. 1 shows a liquid container 2 for a motor vehicle. In the present case, the liquid container 2 is a plastics material fuel container 2. The liquid container 2 has a storage volume 4 for storing a liquid 6. In the present case, the liquid 6 is fuel 6 for a motor driven by combustion engine.

(9) The liquid container 2 has a first half-shell 8 and a second half-shell 10, which delimit the storage volume 4. The half-shells 8, 10 have each been produced by injection molding. In the following, the structural wall construction of the half-shells 8, 10 is described for the half-shell 8 by way of example.

(10) The half-shell 8 has a barrier film 12, which is set up as a permeation barrier to minimize the permeation of hydrocarbons from the storage volume 4 into an environment U.

(11) The half-shell 8 has a reinforcing element 14, which is formed of a thermoplastic fiber-reinforced material.

(12) The half-shell 8 further has a support structure 16, which is formed of an injection-molded material.

(13) In the present case, the half-shell 8 has been produced by injection molding, in that the barrier film 12 and the reinforcing element 14 have been positioned in an injection-molding tool as an inlay and molded using the injection-molded material of the support structure 16.

(14) The barrier film 12 is integrally connected to the reinforcing element 14. For this purpose, the barrier film 12 and the reinforcing element 14 have been heated and welded together.

(15) The barrier film 12 is integrally connected to the support structure 16. The barrier film 12 has been welded to the support structure 16 by the injection molding.

(16) The reinforcing element 14 is integrally connected to the support structure 16. The reinforcing element 14 has been welded to the support structure 16 by the injection molding.

(17) The welding of each of the barrier film 12 and the reinforcing element 14 to the support structure 16 has been achieved by molding the injection-molded material of the support structure 16 onto the reinforcing element 14 and the barrier film 12 within an injection-molding tool.

(18) The welding between the barrier film 12 and the reinforcing element 14 has been produced before molding the support structure 16. As can be seen from the detail Z, the reinforcing element 14 is arranged, at least in portions, between the barrier film 12 and the support structure 16.

(19) It will be appreciated that in further embodiments of the invention a shell may have a plurality of reinforcing elements, which may overlap one another or be arranged spaced apart from one another. It will further be appreciated that in further embodiments of the invention the support structure may be formed multi-part and may for example have separate segments, spaced apart from one another, of local moldings of injection-molded material on the barrier film and/or the reinforcing element.

(20) In the present case, the reinforcing element 14 has reinforcing fibers 18 that are embedded in a thermoplastic plastics material matrix 20. In the present case, glass fibers 18 are provided as reinforcing fibers 18. In alternative embodiments of the invention, alternatively or in addition, aramid fibers and/or carbon fibers may be used as reinforcing fibers.

(21) In the present case, the thermoplastic plastics material matrix 20 of the reinforcing element 14 consists of a polyamide (PA). In the present case, the reinforcing element 14 is reinforced with long fibers. In the present case, the support structure 16 likewise consists of a polyamide (PA).

(22) Specifically, in the present case, the support structure 16 consists of the material PA6, the reinforcing element 14 consisting of glass-fiber-reinforced PA6. The barrier film 12 has cover layers 22, 24, which consist of PA6 and enclose a central layer 26 of the barrier film 12, the central layer 26 consisting of EVOH.

(23) The reinforcing element 14 is a substantially planar plate 14. The reinforcing element 14 of the half-shell 8 is thus part of a base-side wall, delimiting the storage volume 4, of the half-shell 8.

(24) The support structure 16 forms a curved transition 28 from the base-side wall to a side wall 30, delimiting the storage volume 4, of the liquid container 2.

(25) The half-shell 10 likewise has a wall construction consisting of a barrier film 32, a reinforcing element 34 and a support structure 36.

(26) It will be appreciated that the liquid container 2 may, in a known manner, have functional units arranged in the storage volume, such as pumps, lever encoders, valves or the like, which for improved clarity are not shown here.

(27) FIG. 2 is a cross section of a further configuration of a liquid container 38 according to the invention. For the avoidance of repetition, in relation to FIG. 2 merely the differences from the above-described embodiment of FIG. 1 are discussed, like reference numerals being assigned to like features.

(28) In the variant of FIG. 2, the barrier films 12, 32 of the half-shells 8, 10 extend into a connection region 40 formed between the half-shells 8, 10, the half-shells 8, 10 having been welded together along a peripherally encircling collar 42.

(29) The barrier films 12, 32 are likewise integrally interconnected in the connection region 40, in such a way that the barrier films 12, 32 form a substantially closed barrier bladder. In this context, the wording “substantially closed” takes account of the fact that the shown liquid container 38, which is a plastics material fuel container 38, has the obligatory inlet and outlet openings for filling, ventilating and liquid withdrawal, in the region of which a barrier layer is interrupted or cleared in each case so as to make fluid transfer possible. Furthermore, openings or wall clearances for passing electrical lines through or for an encoder module may be provided.

(30) As can be seen from FIG. 2, a first face 44 of the reinforcing element 14 may be covered completely by the barrier film 12. Further, a face 46 of the reinforcing element 14 remote from the first face 44 is completely covered by the support structure 16.

(31) In the variant of FIG. 2, the reinforcing element 14 is accordingly completely embedded between the barrier film 12 and the support structure 16 and thus protected from environmental influences. This equally applies to the reinforcing element 34 of the half-shell 10, which is likewise completely enclosed by the support structure 36 and the barrier film 32.

(32) In the following, the method according to the invention is described with reference to FIGS. 3, 4, 5 and 6.

(33) FIG. 3 shows a device 48 for producing a liquid container 2 or 38 according to the invention, as shown for example in FIGS. 1 and 2.

(34) The device 48 has a first heating device 50 and a second heating device 52. The device 48 additionally has an injection-molding device 54 comprising an injection mold or injection-molding tool 55, which has a first mold half 56 and a second mold half 58, which may also synonymously be referred to as tool halves 56, 58.

(35) The device 48 further has a roll-to-roll film feed-in 60. The film feed-in 60 has a first roll 62 and a second roll 64, which are each arranged laterally with respect to the injection-molding tool 55 or laterally with respect to the first mold half 56 of the injection-molding tool 55.

(36) During the production of a liquid container 2, 38 according to the invention, a barrier film 12, 32 and a reinforcing element 14, 34 for producing a first half-shell 8 or a second half-shell 10 are initially provided. The barrier film 12, 32 and the reinforcing element 14, 34 may be provided simultaneously or in temporal succession.

(37) When the barrier film 12, 34 is provided, the barrier film 12 is initially positioned and fixed in the injection-molding tool 55 formed from the mold halves 56, 58 using the roll-to-roll film feed-in 60. The barrier film 12, 32 can be fixed with respect to the first mold half 56 using sealing elements 66.

(38) The barrier film 12, 32 is heated using the heating device 52. The heating device 52 is a contactless heating device in the form of an infrared radiator 52.

(39) Simultaneously, the reinforcing element 14, 34 is heated using the heating device 50, which likewise has infrared radiators 51.

(40) In the next method step, the barrier film 12, 32 is thermoformed against a tool surface 68 of the first mold half 56, in such a way that the barrier film 12, 32 is brought into the provided shape by thermoforming. The heated reinforcing element 14, 34 is moved between the mold halves 56, 58 using a holding device 70.

(41) The barrier film 12, 32 is thermoformed by producing a vacuum in the region of the tool surface 68, this being made possible in that the mold half 56 is formed at least partially from a porous, air-permeable material. In this context, the barrier film 12, 32 positioned against the mold half 56 is sealed from the environment U against the tool surface 68 using the sealing elements 66, making reliable, vacuum-based thermoforming of the barrier film 12, 32 possible.

(42) The reinforcing element 14, 34 positioned between the mold halves 56, 58 is in the heated state and is pressed against the barrier film 12, 32, which is likewise heated from the preceding thermoforming, so as to weld and thus integrally connect the reinforcing element 14, 34 to the barrier film 12, 32. The reinforcing element 14, 34 is pressed onto the barrier film 12, 32 using a pressing device 69 (FIG. 5).

(43) After the mold halves 56, 58 are closed, the support structure 16 or 36 is molded onto the reinforcing element 14, 34 and the barrier film 12, 32 via an opening 72. After the injection molding process, the half-shell 8, 10 produced in this manner can be removed from the injection-molding tool 55 and welded to a further, analogously produced mold half 8, 10 to form a plastics material fuel container 2, 38 according to the invention.

REFERENCE NUMERALS

(44) 2 Liquid container/plastics material fuel container 4 Storage volume 6 Liquid/fuel 8 First half-shell 10 Second half-shell 12 Barrier film U Environment 14 Reinforcing element 16 Support structure Z Detail 18 Reinforcing fibers/glass fibers 20 Plastics material matrix 22 Cover layer 24 Cover layer 26 Central layer 28 Curved transition 30 Side wall 32 Barrier film 34 Reinforcing element 36 Support structure 38 Liquid container/plastics material fuel container 40 Connection region 42 Encircling collar 44 First face 46 Remote face 48 Device 50 First heating device 51 Infrared radiator 52 Second heating device 54 Injection-molding device 55 Injection-molding tool 56 First mold half/first tool half 58 Second mold half/second tool half 60 Film feed-in 62 First roll 64 Second roll 66 Sealing element/holding frame 68 Tool surface 69 Pressing device 70 Holding device 72 Opening