Plastic fuel tank with support element

Abstract

The present invention relates to a plastic fuel tank (10) for a vehicle, the plastic fuel tank (10) comprising: a lower portion (14) and an upper portion (12); at least one sidewall (16) extending between the lower portion (14) and the upper portion (12); at least one support element (18), the at least one support element (18) having an elongated shape, a longitudinal axis, a first end and a second end at opposite axial ends thereof, the at least one support element (18) having a flange (24) at the first end or the second end, the flange (24) having a flange width and being disposed between the lower portion (14) and the upper portion (12); The upper portion (12) or the lower portion (14) constitutes an integrated receiving structure for receiving the flange (24) of the support element (18), and the receiving structure is formed by the upper portion (12) or the lower portion (14) to form a stepped cavity consisting of a first cavity (28) and a second cavity.

Description

[Technical Field]

[0001] The present invention relates to a plastic fuel tank for a vehicle, an electric vehicle including the fuel tank, and a method for manufacturing the fuel tank. [Background technology]

[0002] Various types of fuel tanks are generally known from the prior art. Fuel tanks are usually made of plastic material or metal. In particular, if the fuel tank is made of plastic material, the mechanical rigidity of the tank may be quite low due to the material properties and the relatively small thickness of the tank body. In order to increase the rigidity of plastic fuel tanks, support elements (also called stiffening elements or reinforcing elements) may be provided that can absorb mechanical forces acting on the fuel tank. These support elements may have an elongated shape and be made of plastic material.

[0003] With typical plastic fuel tanks, the support elements are often made of a thermoplastic material and are welded to the lower and upper portions of the fuel tank. Typically, the support elements are made of the same material as the fuel tank, so they have the same melting temperature, simplifying the welding process. Summary of the Invention [Problem to be solved by the invention]

[0004] Although the aforementioned fuel tanks including support elements connected to the fuel tank body via welded joints have several advantages, fuel tanks of this type also have several disadvantages, such as the manufacturing process is typically difficult and time-consuming because the connection of the support elements to the tank body is sensitive to movement of the support elements during the welding process.

[0005] In view of the above, one object of the present invention is to provide a plastic fuel tank that can be manufactured easily and efficiently. Another object of the present invention is to provide a plastic fuel tank that can be manufactured at low manufacturing costs. A further object of the present invention is to provide a plastic fuel tank with improved mechanical rigidity. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a plastic fuel tank for a vehicle, the plastic fuel tank for a vehicle comprising: A lower portion, an upper portion, at least one sidewall extending between the lower portion and the upper portion, the lower portion, the upper portion, and the at least one sidewall defining an interior volume of the plastic fuel tank, the interior volume configured to contain fuel; at least one support element, the at least one support element comprising: It has an elongated shape and an axis in the longitudinal direction, a first end and a second end at opposite axial ends; a flange at the first end or the second end, the flange having a flange width; It is disposed between the lower and upper parts, The upper or lower portion comprises an integrated receiving structure for receiving a flange of the support element, the receiving structure comprising: formed by an upper portion or a lower portion, a stepped cavity consisting of a first cavity and a second cavity is formed; The first cavity is defined by an outer portion of the upper portion or the lower portion forming a first cavity outer wall and at least one first cavity side wall extending from the first cavity outer wall, wherein the first cavity is disposed adjacent to the second cavity; the second cavity is defined by at least a second cavity sidewall, the second cavity being disposed between the first cavity and an interior volume of the plastic fuel tank; the first cavity has a first cavity width, the second cavity has a second cavity width, the first cavity width being greater than the second cavity width; The flange width is greater than the second cavity width and less than or equal to the first cavity width; It has the following configuration.

[0007] The plastic fuel tank according to the present invention allows a stable attachment of the support element to the plastic fuel tank. Furthermore, the present invention simplifies the manufacturing process because it is not necessary to weld the outer surface of the support element to the upper and lower parts of the fuel tank. This reduces manufacturing costs and increases manufacturing speed.

[0008] At least one side wall can be designed as a ring-shaped wall that surrounds the interior space of the fuel tank. According to some embodiments, the fuel tank can be configured with multiple side walls, for example, four side walls arranged in a rectangular configuration relative to one another that form the interior space of the fuel tank. It is also possible for the fuel tank to be configured with more than four side walls that adjoin one another to form the interior space of the fuel tank. The present invention can be implemented regardless of the number of side walls.

[0009] The support elements are configured to support the fuel tank in the event of overpressure and / or underpressure, thereby preventing or at least reducing the likelihood of the fuel tank collapsing or breaking. The support elements further reduce the likelihood of cracks forming in the upper and lower portions of the fuel tank. The support elements therefore contribute to increasing the rigidity and, therefore, the lifespan of the fuel tank. According to the present invention, multiple support elements can be provided depending on the size and specific design of the fuel tank, and the present invention can be implemented regardless of the specific number of support elements.

[0010] The flanges of the support element may be designed as an integral part of the support element or as a separate part connected to the body of the support element. In the latter case, the flanges may be welded or mechanically connected to the body of the support element. According to the invention, the flanges are provided on the side of the first end and / or the side of the second end of the support element and constitute a width greater than that of the adjacent parts of the support element. According to some embodiments, one flange may be provided to be received in a receiving structure at the upper or lower part. In a preferred embodiment of the invention, the support element has one flange at each of its ends, one flange received in a first receiving structure formed in the upper part of the fuel tank and one flange received in a second receiving structure formed in the bottom part of the fuel tank.

[0011] According to some embodiments of the present invention, the support element and the flange may have a rotationally symmetric shape, where the flange may preferably be configured in a disk shape. In the latter case, the first cavity and the second cavity may have a cylindrical shape, where the diameter of the first cavity is larger than the diameter of the second cavity. According to some embodiments, the stepped cavity may include a second cavity having a uniformly reduced width compared to the first cavity. For example, the first cavity and the second cavity each have a cylindrical shape, where the diameter of the second cavity is reduced by 10%, 20%, 30%, or 50% compared to the first cavity. According to some embodiments, the second cavity may not have a rotationally cylindrical shape, where the width of the second cavity is reduced compared to the first cavity along at least one cross section of the stepped cavity. By providing a receiving structure consisting of a stepped cavity having a first cavity and a second cavity (having a smaller width compared to the first cavity), the flange is locked into the receiving structure in a mechanically stable manner and secured thereto.

[0012] The outer portion of the upper or lower portion refers to a portion of the upper or lower portion that is farther from the interior space of the tank than the first and second cavity side walls. In particular, the outer portion may refer to a portion of the upper or lower portion that is farthest from the interior space of the fuel tank.

[0013] Preferably, the side wall, the lower portion, and the upper portion are integrally designed. Furthermore, the first cavity side wall, the second cavity side wall, and the outer portions of the upper portion and the lower portion may be integrally designed. Therefore, the design of the fuel tank can be simplified, and as a result, the manufacturing cost can be further reduced.

[0014] According to a preferred embodiment of the present invention, the flange has an outer surface oriented away from the axial center of the support element, and the outer surface of the flange is welded to the outer surface of the upper or lower part. This can provide a more stable fixation of the support element in the receiving structure. Furthermore, according to this embodiment, the receiving structure can significantly assist the welding process by positioning the flange in a desired position and maintaining the flange in the desired position during the welding process. This significantly improves the alignment of the support element during the welding process.

[0015] According to some embodiments of the present invention, the height of the first cavity is less than or equal to the height of the flange. Therefore, the flange is axially retained within the first cavity, thereby significantly improving the mechanical stability of the fixation. According to some embodiments, the height of the first cavity is equal to the height of the flange. However, the height of the first cavity can also be selected to be slightly less than the height of the flange. In the latter case, the clamping force induced by the receiving structure increases. It should be noted that the upper part is typically made of a fairly thin plastic structure. Therefore, the receiving structure typically has a certain degree of flexibility and can receive the flange in the first cavity even if the flange height is somewhat greater than the height of the first cavity. Furthermore, if the flange is further welded to the upper or lower part of the fuel tank to create a first cavity with a height slightly less than the height of the flange, the receiving structure applies an axial clamping force to the flange during the welding process, pressing the flange and the lower and upper parts of the fuel tank together. The resulting clamping force improves the welding process. This improves the welding process and provides a more stable attachment between the support element and the upper and / or lower part of the fuel tank.

[0016] According to some embodiments of the present invention, the width of the first cavity may be greater than the width of the flange. According to some preferred embodiments of the present invention, the width of the first cavity may be equal to the width of the flange. As a result of the width of the first cavity being equal to the width of the flange, the flange is radially fixed within the first cavity of the receiving structure. This allows the flange to be radially stably fixed within the first cavity of the receiving structure. Furthermore, when the outer surface of the flange is welded to the outer surface of the upper or lower part, the radial fixation of the support element can simplify the welding process because the flange of the support element is held in a radially stable position during the welding process.

[0017] According to some further preferred embodiments of the present invention, the first cavity has a tapered shape, and the width of the first cavity decreases in a direction from the outer wall of the first cavity toward the second cavity, so that the flange is radially centered within the first cavity when received within the first cavity.

[0018] Furthermore, the flange can be tapered, with the width of the flange decreasing from its outer surface toward the axial center of the support element. The taper angle can be selected according to the taper angle of the first cavity. In other words, the taper angles can be selected to be the same or at least similar. This can improve the radial centering of the flange within the first cavity.

[0019] According to some preferred embodiments of the present invention, the support element has a rotationally symmetrical shape. Furthermore, the first cavity, the second cavity, and the flange may have a rotationally symmetrical shape.

[0020] Preferably, the support element has a tapered shape, with the width of the support element decreasing from its axial ends towards its axial centre, so that the support element can be intentionally broken at a predetermined point if a large force acts on the fuel tank, for example in the event of an accident.

[0021] According to some preferred embodiments of the present invention, the support element has at least one break point configured to break when an axial force exceeding a predetermined threshold is applied to the support element. The break point can be ensured by providing a notch at a specific location in the support element. The depth of the notch can be adjusted depending on the selected force threshold.

[0022] According to a further preferred embodiment of the present invention, the side wall, lower portion, and upper portion of the fuel tank are integrally formed, thereby simplifying the structure of the fuel tank and reducing manufacturing costs.

[0023] According to a further embodiment of the invention, the side walls, the lower portion and the upper portion are at least partially made of a thermoplastic material. Furthermore, the support element and the receiving structure may be made of a thermoplastic material.

[0024] According to some preferred embodiments of the invention, at least part of the side walls, lower part and upper part are made of one of the following materials: polyethylene (PE), high density polyethylene (HDPE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polymethyl methacrylate (PMMA), polyoxymethylene (POM), polyphenylene sulfide (PPS), polyphthalamide (PPA), polyetheretherketone (PEEK), polyamideimide (PAI) or polyaryletherketone (PAEK). According to further embodiments of the invention, the support element and / or the receiving structure can be at least partly made of one of the aforementioned materials.

[0025] According to some embodiments of the invention, the fuel tank is designed as a single tank or as a saddle tank. According to the invention, a motor vehicle is proposed, which comprises a fuel tank according to one of the above-mentioned embodiments.

[0026] According to the invention, a method for manufacturing a fuel tank according to one of the above-mentioned embodiments is proposed, which method uses a blow molding process and which method comprises the following steps: a process for providing a parison made of a plastic material in an interior space of a mold, the parison defining the interior space, wherein the mold is comprised of two halves and is designed to form a desired shape of a fuel tank, the mold having a first opening and a second opening, the first opening being disposed on a first side of the mold and the second opening being disposed on a second side of the mold, the second side being opposite the first side, the first opening being configured to insert the parison into the mold, and the second opening being configured to insert a support element into the interior space of the parison; Inserting a support element into the internal space of the parison; Compressed air is blown into the parison to expand it. The two halves of the mold are brought close together to form an expanded parison that conforms to the shape of the mold. The interior space of the mold is cooled, and the formed fuel tank is solidified.

[0027] The method according to the invention allows for an efficient and cost-effective process for manufacturing plastic fuel tanks. The proposed method does not require welding the outer surface of the support element to the fuel tank components. However, in some embodiments of the method according to the invention, the outer surface of the flange can be welded to the upper or lower part of the fuel tank to increase the strength of the attachment between the support element and the upper / lower part of the fuel tank. [Brief explanation of the drawings]

[0028] The invention will now be further described in relation to the accompanying drawings, which are shown as follows:

[0029] [Figure 1] 1 is a prior art fuel tank. [Figure 2] 1 is an embodiment of a fuel tank according to the present invention. [Figure 3] FIG. 3 is an enlarged view of one embodiment of the present invention shown in FIG. 2. [Figure 4]FIG. 10 is an enlarged view of a further embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] 1 shows a schematic representation of a typical fuel tank 10 known from the prior art. The fuel tank 10 is comprised of an upper portion 12, a lower portion 14, and a side wall 16. The side wall 16 may be designed as a ring-shaped wall surrounding an interior space 22 of the fuel tank 10. A support element 18 is provided within the interior space 22. The support element 18 is arranged between the upper portion 12 and the lower portion 14 of the fuel tank 10. The support element 18 has an outer surface 20 and is typically welded to the upper portion 12 and the lower portion 14 during the manufacturing process of the fuel tank 10.

[0031] FIG. 2 schematically illustrates one embodiment of a fuel tank 10 according to the present invention. Similar to the fuel tank illustrated in FIG. 1, the fuel tank 10 illustrated in FIG. 2 also comprises an upper portion 12, a lower portion 14, and a sidewall 16, which together define an interior space 22 of the fuel tank 10. The fuel tank 10 further comprises a support element 18 at its outer end, which comprises a flange 24. Furthermore, the fuel tank 10 comprises receiving structures integrated into the interior of the upper portion 12 and the lower portion 14. Each of the receiving structures comprises a first cavity 28 and a second cavity 30, where the width of the first cavity 28 is greater than the width of the second cavity 30, and the width of the flange 24 is greater than the width of the second cavity 30 but smaller than the width of the first cavity 28. The receiving structures are thus configured to receive the flange 24 within the first cavity 28. Therefore, the support element 18 can be stably attached to the fuel tank 10 in a simplified and effective manner.

[0032] FIG. 3 shows an enlarged view of the embodiment shown in FIG. 2. As can be seen from FIG. 3, the receiving structure comprises a first cavity 28 and a second cavity 30, with the width of the second cavity 30 being smaller than the width of the first cavity 28. Thus, the receiving structure formed in the upper portion 12 of the fuel tank 10 is configured to receive the flange 24 of the support element 18. As further shown in FIG. 3, the first cavity 28 is defined by an outer portion 26 of the upper portion 12, which forms the first cavity outer wall, and a first cavity sidewall 32. The first cavity sidewall 32 extends from the outer portion 26 and defines the height of the first cavity 28. The second cavity 30 is defined by a second cavity sidewall 34, which defines the height and width of the second cavity 30. 3, the width of the flange 24 is greater than the width of the second cavity 30 and slightly less than the width of the first cavity 28. Thus, the flange 24 of the support element 18 is stably fixed within the receiving structure.

[0033] An enlarged view of a further embodiment of the present invention is shown in Figure 4. As shown in Figure 4, the first cavity has a tapered structure, with the diameter of the cavity decreasing in a direction from the outer portion 26 of the upper part 12 of the fuel tank 10 toward the second cavity 30. At the same time, the flange 24 has a tapered structure, with the diameter of the flange decreasing from the outer surface of the flange 24 facing the outer portion 26 toward the axis of the support element 18. As further shown in Figure 4, the taper angles of the first cavity 28 and the flange 24 are selected to be the same. Thus, the flange 24 is radially centered within the first cavity 28. [Explanation of symbols]

[0034] 10: Fuel tank 20: Upper part 14: Lower part 16: Side wall 18: Support element 20: Outer surface of support element 22: Interior space 24: Flange 26: Outer part of upper / lower part 28: First cavity 30: Second cavity 32: First cavity sidewall 34: Second cavity sidewall

Claims

1. a lower portion (14) and an upper portion (12); the plastic fuel tank has at least one sidewall between the lower portion and the upper portion, the lower portion, the upper portion, and the sidewall defining an interior space for containing fuel; At least one support element (18), said at least one support element (18) comprising: It has an elongated shape and an axis in the longitudinal direction, an axial end portion having a first end portion and a second end portion; a flange (24) at the first end or the second end, the flange (24) having a flange width; disposed between the upper portion and the lower portion, The upper part (12) or the lower part (14) comprises an integrated receiving structure for receiving a flange (24) of a support element (18), the receiving structure comprising: formed by the upper part (12) or the lower part (14), forming a stepped cavity consisting of a first cavity (28) and a second cavity (30); The first cavity (28) is defined by an outer portion (26) of the upper portion or the lower portion forming a first cavity outer wall and at least one first cavity side wall (32) extending from the first cavity outer wall, and the first cavity (28) is disposed adjacent to the second cavity (30); the second cavity (30) is defined by at least a second cavity sidewall (34), and the second cavity (30) is disposed between the first cavity (28) and the interior space (22) of the plastic fuel tank; the first cavity (28) has a first cavity width and the second cavity (30) has a second cavity width, the first cavity width being greater than the second cavity width; the flange width is greater than the second cavity width and less than or equal to the first cavity width; The first cavity (28) has a tapered shape, and the width of the first cavity (28) decreases in a direction from the outer wall of the first cavity toward the second cavity (30); the flange (24) has an outer surface directed away from the axial center of the support element (18), and the outer surface of the flange (24) is welded to the outer portion (26) of the upper or lower part; A plastic fuel tank (10) for a vehicle, comprising:

2. 2. The fuel tank (10) of claim 1, wherein the height of the first cavity (28) is less than or equal to the height of the flange (24).

3. 2. The fuel tank (10) of claim 1, wherein the width of the first cavity (28) is equal to the width of the flange (24).

4. 2. The fuel tank (10) according to claim 1, wherein the support element (18) is of a rotationally symmetrical shape.

5. 2. The fuel tank (10) of claim 1, wherein the support element (18) has a tapered shape, and the width of the support element (18) decreases from both axial ends toward the axial center.

6. 2. The fuel tank (10) of claim 1, wherein the support element (18) has at least one break point configured to break when an axial force exceeding a predetermined force threshold is applied to the support element (18).

7. 2. The fuel tank (10) of claim 1, wherein said sidewall (16), said lower portion (14), and said upper portion (12) are integrally formed.

8. 2. The fuel tank (10) of claim 1, wherein the sidewall (16), the lower portion (14), and the upper portion (12) are at least partially made of a thermoplastic material.

9. 2. The fuel tank (10) of claim 1, wherein the side wall (16), the lower portion (14), and the upper portion (12) are at least partially formed from any one of polyethylene (PE), high density polyethylene (HDPE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polymethyl methacrylate (PMMA), polyoxymethylene (POM), polyphenylene sulfide (PPS), polyphenylamide (PPA), polyetheretherketone (PEEK), polyamideimide (PAI), or polyaryletherketone (PAEK).

10. 2. The fuel tank (10) according to claim 1, characterized in that the fuel tank (10) is designed as a single tank or a saddle tank.

11. A motor vehicle comprising a fuel tank (10) according to any one of claims 1 to 10.

12. 11. A method for manufacturing a fuel tank (10) according to any one of claims 1 to 10 by a blow moulding process, said method comprising the steps of: a parison made of a plastic material is provided in an interior space of a mold, wherein the parison defines the interior space; the mold is comprised of two halves and is designed to form a desired shape of the fuel tank; the mold has a first opening and a second opening, the first opening being located on a first side of the mold and the second opening being located on a second side of the mold, the second side facing the first side; the first opening being configured to insert the parison into the mold; and the second opening being configured to insert a support element into the interior space of the parison; Inserting the support element into the interior space of the parison; Compressed air is blown into the parison to expand the parison; Bringing the two halves of the mold closer together to form the parison expanded to fit the shape of the mold; cooling the interior space of the mold to solidify the formed fuel tank; A method for manufacturing a fuel tank, comprising:

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