Vehicle fuel tank and method for manufacturing a vehicle fuel tank

Abstract

Vehicle fuel tank (10), comprising a fuel reservoir (12) made of sheet metal and at least one retaining element (14) attached to the fuel reservoir (12) and manufactured separately from the fuel reservoir (12) for attaching the vehicle fuel tank (10) to the vehicle, wherein the retaining element (14) is attached to the fuel reservoir (12) in such a way that it can only be detached from it by destroying it, and wherein the retaining element (14) has a flange (16) to which it is attached to the fuel reservoir (12), and wherein the retaining element (14) has at least a first section (20) which is made of a plastic material.

Description

[0001] The invention relates to a vehicle fuel tank for a motor vehicle.

[0002] A vehicle fuel tank comprises a fuel reservoir that can hold fuel for the internal combustion engine of a motor vehicle. The fuel reservoir is typically attached to the vehicle body by several mounting elements, which are also part of the vehicle fuel tank.

[0003] The mounting elements are subject to special requirements regarding their vibration and oscillation behavior, as they must dampen any vibrations that occur. Furthermore, the mounting elements are designed to decouple the vibrations of the vehicle body from the fuel tank, ensuring that the tank is attached to the vehicle body with minimal vibration. To meet these requirements, the mounting elements are complexly designed.

[0004] Various types of vehicle fuel tanks are known from the prior art. For example, there are prior art fuel tanks that have a fuel reservoir made of sheet metal and a mounting element welded to it, also made of sheet metal. However, these fuel tanks have disadvantages with regard to vibration decoupling, as the production of the mounting elements is very complex and expensive in order to achieve the desired decoupling and damping properties. In addition, fuel tanks manufactured in this way are subject to larger manufacturing tolerances, which is why the adjustment, especially with regard to long-term load-bearing capacity, is very time-consuming.

[0005] Furthermore, vehicle fuel tanks are known from the prior art that have a fuel reservoir made of plastic. These plastic fuel reservoirs are so-called blow-molded tanks, in which the retaining elements are also made of plastic. The retaining elements are manufactured cost-effectively using an injection molding process and then used as inserts during the blow-molding process of the fuel reservoir to connect it to the fuel reservoir. The connection of the retaining elements therefore takes place during the manufacturing of the fuel reservoir.

[0006] However, vehicle fuel tanks with a plastic fuel reservoir have disadvantages regarding impact behavior in an accident. Furthermore, the production of plastic fuel reservoirs presents problems with HC emissions, i.e., the emission of volatile hydrocarbons.

[0007] DE 10 2012 022 959 A1 relates to a fastening device for a tank on a motor vehicle, comprising a console for receiving the tank, wherein the console is made of a fiber composite plastic.

[0008] DE 10 2007 001 898 A1 relates to a profile base for a console for attaching a container, in particular a fuel tank, to a load-bearing component of a truck.

[0009] The object of the invention is to provide a vehicle fuel tank with which the disadvantages known from the prior art can be overcome.

[0010] The object is solved according to the invention by a vehicle fuel tank, comprising a fuel container made of a sheet metal and a retaining element attached to the fuel container, which is manufactured separately from the fuel container, for attaching the vehicle fuel tank to the vehicle, wherein the retaining element has a flange to which it is attached to the fuel container, and wherein the retaining element has at least a first section which is made of a plastic material.

[0011] The basic idea of ​​the invention is to create a vehicle fuel tank that has at least one retaining element which can be manufactured simply and cost-effectively and is suitable for connection to a sheet metal fuel tank. Manufacturing is simplified and cost-effective because the retaining element is formed, at least partially, from a plastic material, making it easier to realize more complex geometries than with known sheet metal parts. Furthermore, it is possible to reduce emissions during the manufacture of the vehicle fuel tank and improve its durability, since a sheet metal fuel tank is used.

[0012] One aspect stipulates that at least the first section is designed for connecting components or decoupling vibrations and / or shocks. Body parts, a seat, locks, or various other components can be attached to this first section, which is made of a plastic material. Due to its material, this first section serves, for example, to decouple vibrations and absorb impacts. Furthermore, a receptacle for vibration decoupling elements can be easily and cost-effectively integrated into the mounting element.

[0013] The flange can also be made entirely or partially from plastic, either in contact with the fuel tank. Vibration decoupling and shock absorption can be improved, as the entire mounting element can serve this purpose.

[0014] According to one embodiment, the retaining element consists of at least two different materials. Accordingly, the vehicle fuel tank has at least one retaining element designed as a hybrid component, which can be manufactured simply and cost-effectively and combines the advantages of different designs known from the prior art. This allows for a combination of connection types, in particular the connection to the fuel tank and the connection to the vehicle body.

[0015] For example, the retaining element can have at least one second section made of sheet metal, which can therefore be manufactured in a simpler and even more cost-effective way.

[0016] Furthermore, it is conceivable to weld the retaining element to the fuel tank.

[0017] The first section, for example, has a more complex geometry compared to the second section. This further simplifies the manufacturing process of the retaining element, as the complex geometry is achieved through the plastic part, which is particularly easy to produce using injection molding. The simple geometry of the second section, on the other hand, can be provided cost-effectively by a section made of a different material, such as sheet metal. This allows the injection molding process to be applied only to the part of the retaining element that would be very difficult to produce using sheet metal.

[0018] Furthermore, it can be provided that the retaining element is essentially made entirely of the plastic material. In this case, the plastic material provides the connection areas of the retaining element, i.e., the attachment section to the vehicle body and the flange for attachment to the fuel tank.

[0019] If the sheet metal forms a core, it is at least partially embedded in the plastic material. The sheet metal can contribute to the rigidity of the retaining element. Alternatively, the sheet metal can be embedded only in sections of the plastic material to create a retaining element with a first connection section, for example, for attaching the retaining element to the vehicle, and a second connection section, the flange, for attaching the retaining element to the fuel tank. The embedded section of the sheet metal has, for example, at least one opening through which plastic flows to ensure secure anchoring of the sheet metal within the plastic.

[0020] The retaining element is attached to the fuel tank in such a way that it can only be removed by destroying it.

[0021] Another aspect is that the retaining element can be riveted to the fuel tank with its flange, particularly using self-piercing rivets. This ensures that no deformation of the retaining element or the fuel tank occurs, as can happen with welding due to the heat input. Welding distortion is thus avoided.

[0022] The object is further achieved according to the invention by a method for manufacturing a vehicle fuel tank, comprising a fuel container made of a sheet metal and a retaining element for attaching the vehicle fuel tank to the vehicle, comprising the following steps: a) Provide a sheet of metal, b) at least partially overmolding the sheet metal with a plastic material to form the retaining element, and c) Attaching the retaining element to the fuel tank, in particular by riveting.

[0023] The inventive method makes it possible to provide a vehicle fuel tank that combines the advantages of the types known from the prior art, ensuring high impact resistance of the vehicle fuel tank while simultaneously decoupling vibrations.

[0024] Furthermore, the sheet metal can be formed before step b), in particular, a maximum of one forming step can be performed. This ensures a particularly simple manufacturing process, as the sheet metal forms a very simply shaped part of the retaining element, thus saving time-consuming forming processes of the sheet metal. The sheet metal can be formed multiple times in this single forming step. The sheet metal can therefore undergo the maximum number of possible forming or conversions that can be achieved in a single forming step.

[0025] Further advantages and features of the invention will become apparent from the following description and the drawings, to which reference is made. The drawings show: - Fig. 1 a schematic perspective view of a vehicle fuel tank according to a first embodiment according to the invention, - Fig. 2 a sectional view along line AA of the Fig. 1, - Fig. 3 a sectional view of a vehicle fuel tank according to a second embodiment according to the invention, - Fig. 4 a sectional view of a vehicle fuel tank according to a third embodiment of the invention, and - Fig. 5 a sectional view of a vehicle fuel tank according to a fourth embodiment according to the invention.

[0026] In the Fig. Figure 1 shows a vehicle fuel tank 10 which has a fuel reservoir 12 made of a sheet metal.

[0027] The vehicle fuel tank 10 further comprises at least one retaining element 14, which is designed separately from the fuel tank 12, but is permanently attached to the fuel tank 12.

[0028] The retaining element 14 has a flange 16 with which the retaining element 14 is attached to the fuel tank 12, and a fastening section 18 which is provided for connecting the retaining element 14 to a vehicle body not shown here.

[0029] In the embodiment shown, the retaining element 14 is designed as a hybrid component comprising a first section 20 made of a plastic material and a second section 22 made of a sheet metal.

[0030] In the embodiment shown, the first section 20 comprises the fastening section 18 and a connection area 24, with which the first section 20 is coupled to the second section 22 made from the sheet metal.

[0031] The fastening section 18 is formed, for example, by two projections 26 that extend from the connection area 24 and have a material thickness D of 10 mm to 18 mm. This material thickness ensures that the retaining element 14 acts as a vibration decoupling device when attached to the vehicle body.

[0032] For attaching the retaining element 14 or the vehicle fuel tank 10 to a vehicle body, the fastening section 18 has an opening 28 on each of the projections 26 through which a fastening element can extend. The fastening element can be a screw, a bolt, or a rivet.

[0033] The second section 22, which is made of a sheet metal, includes, as already mentioned, the flange 16, which is formed by a support plate 30, which is welded to the fuel tank 12, for example, which is not to be understood as restrictive.

[0034] Furthermore, the second section 22 comprises a support core 32, which is also welded to the flange 16 consisting of the support plate 30. The corresponding weld 34 is shown in Fig. 1 shown.

[0035] The support core 32 is also connected to the connection area 24 of the first section 20, so that the connection area 24 and the support core 32 form the transition from the plastic material of the first section 20 to the sheet metal of the second section 22. For this purpose, the support core 32 is at least partially embedded in the plastic material of the connection area 24. This was achieved during the manufacture of the retaining element 14, which was produced separately from the fuel tank 12, by overmolding the sheet metal of the support core 32 at least partially with the plastic material of the first section 20.

[0036] This is particularly true in the Fig. 2 shown, in which the vehicle fuel tank 10 of the Fig. Figure 1 shows a sectional view along line AA. The sectional view clearly shows that the sheet metal of the support core 32 is partially embedded in the plastic material of the connection area 24.

[0037] Furthermore, it is evident from the Fig. 2 shows that the connection area 24 and the fastening section 18 or the projections 26 are formed in one piece.

[0038] Accordingly, a vehicle fuel tank 10 is designed with a retaining element 14 that is manufactured separately from the fuel tank 12 and is also made of at least two different materials. Due to the different materials, such a retaining element 14 is therefore a hybrid component.

[0039] The first section 20, which is made of a plastic material and therefore serves for vibration decoupling, has a more complex geometry compared to the second section 22. This allows the retaining element 14 to be manufactured in a particularly simple and cost-effective manner, since the sheet metal of the second section 22 does not require complex forming to achieve its vibration-damping properties.

[0040] In the embodiment shown, the sheet metal of the second section 22 has been reshaped at its edges before it has been overmolded with the first section 20.

[0041] The flange 16 can alternatively be connected to the fuel tank 12 by means of punch rivets instead of the welded connection shown.

[0042] Furthermore, the second section 22 can be made of a material other than a sheet of metal.

[0043] In the Fig. Figure 3 shows a vehicle fuel tank 10 according to a second embodiment, which differs from the first embodiment in that the second section 22 is formed from a single sheet, i.e. without a support sheet 30.

[0044] The flange 16 and the support core 32 are thus formed in one piece and are not connected to each other by a weld. The sheet metal of the second section 22 has been formed once to create the flange 16, with which the retaining element 14 can be attached to the fuel tank 12.

[0045] In this embodiment, the sheet metal of the second section 22 may have been formed before or after overmolding with the first section 20 to form the flange 16.

[0046] In the illustrated embodiment, the fastening of the retaining element 14 to the fuel tank 12 via the second section 22 is effected by means of punch rivets 36. This ensures that no heat is introduced into the fuel tank 12 or the second section 22 that would lead to weld distortion.

[0047] The force distribution and transmission can be adjusted accordingly by changing the number of punch rivets (36).

[0048] Alternatively, the connection can also be made here as in the first embodiment according to the Fig. 1. by a welding process.

[0049] In the Fig. Figure 4 shows a third embodiment of the vehicle fuel tank 10 according to the invention, in which the entire retaining element 14 is made of a plastic material.

[0050] In this embodiment, both the first section 20 and the second section 22 are therefore made of a plastic material, with the retaining element 14 being connected to the plastic container 12 via its second section 22 by means of punch rivets 36. Accordingly, the entire retaining element 14 is formed in one piece, as shown in the Fig. 4 emerges.

[0051] Due to the different materials in the contact area of ​​the fuel tank 12 with the retaining element 14, a mechanical connection is preferred over a welded connection.

[0052] In a fourth embodiment, which is described in Fig. As shown in Figure 5, the retaining element 14 is designed as a hybrid component comprising two materials. In this embodiment, the support core 32, which is made of sheet metal, is completely embedded in a plastic material.

[0053] In the embodiment shown, the support core 32 extends into the first section 20, which has the more complex geometry provided for shock absorption and vibration decoupling.

[0054] Accordingly, the support core 32 contributes to increasing the stiffness of the retaining element 14, particularly in the transition area from the first section 20, which is intended for vibration decoupling, to the flange 16.

Claims

[1] Vehicle fuel tank (10), comprising a fuel reservoir (12) made of sheet metal and at least one retaining element (14) attached to the fuel reservoir (12) and manufactured separately from the fuel reservoir (12) for attaching the vehicle fuel tank (10) to the vehicle, wherein the retaining element (14) is attached to the fuel reservoir (12) in such a way that it can only be detached from it by destroying it, and wherein the retaining element (14) has a flange (16) to which it is attached to the fuel reservoir (12), and wherein the retaining element (14) has at least a first section (20) which is made of a plastic material. [2] Vehicle fuel tank (10) according to claim 1, characterized by , that at least the first section (20) is designed for connecting components or for decoupling vibrations and / or shocks. [3] Vehicle fuel tank (10) according to claim 2, characterized bythat the flange (16) is made entirely or in the contact area with the fuel tank (12) of plastic. [4] Vehicle fuel tank (10) according to any of the preceding claims, characterized by , that the retaining element (14) consists of at least two different materials. [5] Vehicle fuel tank (10) according to claim 4, characterized by , that the retaining element (14) has at least a second section (22) which is formed from a sheet metal part. [6] Vehicle fuel tank (10) according to claim 4 or 5, characterized by , that the first section (20) has a more complex geometry compared to the second section (22). [7] Vehicle fuel tank (10) according to one of claims 1 to 4 or 6, characterized by , that the retaining element (14) is formed entirely from the plastic material. [8] Vehicle fuel tank (10) according to any one of claims 1 to 6, characterized by, that the sheet metal forms a support core (32) which is at least partially embedded in the plastic material. [9] Vehicle fuel tank (10) according to any of the preceding claims, characterized by , that the retaining element (14) with its flange (16) is riveted to the fuel tank (12), in particular by means of punch rivets (36). [10] Method for manufacturing a vehicle fuel tank (10) with a fuel container (12) made of a sheet metal and a retaining element (14) for attaching the vehicle fuel tank (10) to the vehicle, comprising the following steps: a) Providing a sheet of metal, b) At least partially overmolding the sheet metal with a plastic material to form the retaining element (14), and c) Attaching the retaining element (14) to the fuel tank (12) in such a way that it can only be detached from it by destroying it. [11] Method according to claim 10, characterized by, that the sheet metal is formed before step b), in particular that a maximum of one forming step is carried out.

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