Method for producing a liquid container, liquid container for a motor vehicle, and structure for reducing sloshing sounds

Abstract

The invention relates to a method for producing a liquid container for a motor vehicle, having the method steps: providing a wall, which is provided in order to delimit an interior chamber of the liquid container for receiving a liquid; providing a structure, which is provided in order to be arranged in order to reduce sloshing noises in the interior chamber of the liquid container, wherein the structure comprises a random arrangement of threads cross-linked with each other and wherein a plurality of the threads of the structure are integrally joined, at least in sections, to at least one or more additional threads of the structure, such that a substantially monolithic structure is formed; connecting the structure to the wall.

Claims

1. A method for producing a liquid container (28) for a motor vehicle, the method steps comprising: providing a wall (14) configured to delimit an interior (26) of the liquid container (28) for receiving a liquid (34) and containing the liquid (34) therein, the wall (14) being formed of one shell or two half-shells; providing a structure (2) configured to be arranged in the interior (26) of the liquid container (28) in order to reduce sloshing sounds, wherein the structure (2) comprises a random arrangement of interlinked threads (4), and wherein a multiplicity of the threads (4) of the structure (2) are connected at least in portions by substance bonding to at least one or more further threads (4) of the structure (2) such that no threads (4) can be removed separately; and welding and/or gluing the structure (2) directly to the shell or at least one of the half-shells of the wall (14) so that a substance-bonded connection is formed between the structure (2) and the wall (14).

2. The method as claimed in claim 1, characterized in that the step of welding and/or gluing the structure (2) directly to the wall (14) further comprises producing an inseparable connection between the structure (2) and the wall (14) so that the wall (14) and the structure (2) are formed integrally.

3. The method as claimed in claim 1, characterized in that during connection to the structure (2), the wall (14) is in an at least partially plasticized state.

4. The method as claimed in claim 1, characterized in that the step of welding and/or gluing the structure (2) directly to the wall (14) further comprises pressing the structure (2) against the wall (14) so that a form-fit connection is formed between the structure (2) and the wall (14), wherein during connection to the structure (2), the wall (14) is in an at least partially plasticized state.

5. The method as claimed in claim 1, characterized in that the step of welding and/or gluing the structure (2) directly to the wall (14) further comprises one of the following method steps: producing a full-surface connection between structure (2) and the wall (14), so that a plurality of randomly arranged connecting points are formed between the structure (2) and the wall (14) and distributed over a connecting region (16); or producing separate or local connecting regions between the wall (14) and the structure (2).

6. The method as claimed in claim 1, characterized in that the structure (2) is deformed at least in portions for bearing against the wall (14).

7. The method as claimed in claim 1, characterized in that the step of providing the wall (14) comprises: extruding a preform (24) configured to be formed into a wall (14) of the liquid container (28) by blow molding; introducing the preform (24) into a blow-molding tool (22); and forming the wall (14) of the liquid container by pressurization of the preform inside the blow-molding tool (22); and that the step of welding and/or gluing the structure (2) directly to the wall (14) further comprises: introducing the structure (2) into the interior (26), wherein the wall (14) is arranged inside the blow-molding tool (22) during insertion of the structure (2).

8. The method as claimed in claim 1, characterized in that the step of welding and/or gluing the structure (2) directly to the wall (14) further comprises at least one of the following method steps: arranging the structure (2) on an actuator (30) configured for inserting the structure (2) into the interior (26) and pressing the structure (2) against the wall (14); and arranging the structure (2) on a joining frame configured in particular to be arranged between half shells of the wall (14) of the liquid container (28).

9. The method as claimed in claim 1, characterized in that the step of providing the structure (2) comprises at least one of the following method steps: providing a mat semifinished product; making the structure (2) from the mat semifinished product along at least one separating plane (12); and finishing the structure (2) in the region of the separating plane (12) and/or in the region of covering surfaces (18), in particular by hot caulking, rolling, sealing or welding.

10. The method as claimed in claim 1, characterized in that the step of providing the wall (14) comprises the following method step: extrusion of at least two mat preforms configured to be connected to the wall (14).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in more detail below with reference to some exemplary embodiments. The drawings indicate diagrammatically:

(2) FIG. 1A a structure according to the invention in a perspective view from above;

(3) FIG. 1B a further structure according to the invention in a perspective view from above;

(4) FIG. 2A the rolling of the structure;

(5) FIG. 2B the hot caulking of a structure;

(6) FIG. 3A an extract of a wall of a liquid container with a structure;

(7) FIG. 3B a further extract of a wall of the liquid container with a structure;

(8) FIG. 4A a device for producing a liquid container;

(9) FIG. 4B a liquid container according to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(10) FIG. 1A shows a structure 2 according to the invention for reducing sloshing sounds, which is intended to be arranged in a liquid container 28 (FIG. 4B) of a motor vehicle. The structure 2 has a random arrangement of interlinked threads 4. A multiplicity of threads 4 of the structure 2 are connected at least in portions by substance bonding to at least one or more further threads 4 of the structure 2 such that a substantially monolithic structure 2 is formed.

(11) The structure 2 contains a plurality of randomly arranged connecting points, in the present case local weld points of crossing threads 4. The substance-bonded connection between the threads 4 is formed in each case by local welding of the threads 4 in the region of their casing surfaces 6, as depicted in exemplary fashion in FIG. 1A. The threads 4 of the structure 2 are made of HDPE.

(12) FIG. 1B shows a further embodiment of a structure 2 according to the invention. In the case of the structure 2 shown in FIG. 1B, each of the threads 4 of the structure 2 is connected by substance bonding to at least one further thread 4 of the structure 2 so that a monolithic structure 2 is formed. The structure 2 consequently contains no threads 4 which could be detached from the structure 2 without destruction.

(13) As in the structure 2 shown in FIG. 1A, the structure 2 depicted in FIG. 1B has chaotically tangled, interlinked threads 4 which are locally welded together to form a thread mesh. The dotted lines in FIG. 1B indicate the substantially cuboid volume assumed by the structure 2. The structure 2 has a multiplicity of randomly arranged connecting points of crossing threads 4 which are distributed over its entire volume and in the present case are formed as local weld points of the threads 4.

(14) A structure 2 shown in FIG. 1A or 1B may be provided as an endless material in the form of a matting or plate-like product, and may be made up from this for use in a liquid container.

(15) The structure 2 may be compacted by rollers 8 as shown in FIG. 2A. The arrows in this depiction indicate the movement direction of the rollers and the rolled structure. In this way, the thread density required for the respective application may be set. The structure 2 is rolled in a heated state in which shaping is possible without destroying the substance-bonded connections between the threads 4. The structure 2 is adapted by thermoforming, by means of the rollers 8, to a wall shape of a liquid container 28 and/or is locally compacted in the edge regions assigned to the rollers.

(16) In order to compact or form the structure 2, or to weld individual thread ends to the structure after making up, a device 10 may be provided for hot caulking of the separating or covering surfaces 12 of the structure 2 using pressure and heat.

(17) FIG. 3A shows an extract of a wall 14 of a liquid container 28 (FIG. 4B) which is welded to a structure 2 in a connecting region 16. The structure 2 is inseparably connected by substance bonding to the wall 14 and therefore formed integrally with the wall 14. The structure 2 has been connected to the wall 14 in the forming heat of the wall 14. A substantially full-surface connection is provided between the structure 2 and the wall 14, so that a plurality of randomly arranged connecting points are formed between the structure 2 and the wall 14, distributed over the connecting region 16. The connecting region 16 may extend over an entire covering surface 18 of a cuboid structure 2 from FIG. 1B. Such a covering surface 18, which may comprise the connecting region 16, may be defined by rolling (FIG. 2A).

(18) FIG. 3B depicts a form-fit connection between the wall 14 and structure 2, which was also formed in the forming heat of the wall 14. Here, the thread ends and thread loops 20 of the threads 4 protrude into the wall 14 in the connecting region 16 and are at least partially surrounded by the material of the wall 14.

(19) FIG. 4A shows a blow-molding tool 22 for creating a wall 14 for a liquid container 28. Firstly, a preform 24 extruded in the manner of a hose is introduced into the two-piece blow-molding tool 22. The wall 14 is formed from the preform 24 by internal pressurization by means of a blowing mandrel (not shown). The wall defines an interior 26 of the liquid container 28 (FIG. 4B).

(20) By means of an actuator 30, the structure 2 is introduced into the blow-molding tool at the end and connected to the wall 14 in the forming heat of the wall 14. For this, the structure 2 is pressed against the wall 14. For superficial contact on the wall 14, the structure 2 is at least partially deformed. Individual structural elements 2 may be attached to both vertical and horizontal wall portions.

(21) FIG. 4B shows a fuel tank 28 in which a structure 2 has been arranged in the corner regions 32 in order to damp the sloshing sounds caused by wave movements of the liquid 34.

LIST OF REFERENCE SIGNS

(22) 2 Structure 4 Threads 6 Casing surfaces 8 Rollers 10 Hot-caulking device 12 Separating surfaces 14 Wall 16 Connecting region 18 Covering surfaces 20 Thread ends/thread loops 22 Blow-molding tool 24 Preform 26 Interior 28 Fuel tank/liquid container 30 Actuator 32 Corner regions 34 Liquid