DE102020114941A1 - Method of manufacturing a wheel arch liner - Google Patents

Abstract

The invention relates to a method for producing a wheel arch shell (11) for a vehicle wheel house (7), which has a shell body (13) and a cover (15) formed thereon for widening the fender. The method has the following process steps: providing a flat nonwoven semifinished product (17) made of thermoplastic fibers (19, 23), and hot forming of the nonwoven semifinished product (17) into the wheel arch shell (11) in a thermoforming process.

Description

The invention relates to a method for producing a wheel arch liner for a vehicle wheel house of a two-lane vehicle according to the preamble of claim 1. In addition, the invention relates to a method for producing a fiber fleece component according to the preamble of claim 10.

The legislature requires that the tread of a vehicle wheel in the vertical direction of the vehicle is covered by the fender over an angular range towards the front of the vehicle and towards the rear of the vehicle. This can be achieved with a suitably wide fender or, alternatively, with a so-called flap or a cover to widen the fender. When installed, the cover protrudes beyond a fender edge delimiting the vehicle wheel arch in the transverse direction of the vehicle to the outside of the vehicle in order to comply with the upward coverage of the vehicle wheel running surface required by law.

A generic wheel arch liner has a shell body that surrounds the vehicle wheel at a distance and a flap (or a cover) formed thereon for widening the fender. Such a wheel housing liner is produced in the prior art using a plastic injection molding process. The panel molded onto the shell body of the wheel arch liner must meet corresponding design requirements as a visible part (hereinafter also generally referred to as the visible design area). In addition, the panel must have sufficient dimensional stability

In addition to such a wheel housing liner made by the plastic injection molding process, a wheel housing liner made from nonwoven material is also known. Compared to the injection-molded wheel arch liner, this can provide improved noise dampening during driving. Such wheel arch liners are from the DE 20 2005 015 164 U1 and from the DE 10 2018 110 246 A1 known. Such a fiber fleece wheel arch liner has, compared to the injection molded wheel arch liner, a reduced dimensional stability and a visually disadvantageous appearance. The fiber fleece wheel arch liner is therefore arranged completely hidden from view within the vehicle wheel house.

The object of the invention is to provide a method for producing a wheel arch liner for a vehicle wheel house which has increased functionality compared to the prior art.

The object is achieved by the features of claim 1, 10, 11 or 12. Preferred developments of the invention are disclosed in the subclaims.

The fiber fleece wheel arch liner according to the invention has, in a double function, both increased noise insulation compared to an injection-molded wheel arch liner and a cover (that is to say flap) formed thereon for widening the fender. According to the characterizing part of claim 1, the wheel arch liner with a cover (flap) formed thereon is produced using the following process steps: First, a flat nonwoven semi-finished product made of thermoplastic fibers is provided. The semi-finished fleece is formed into the wheel arch liner in a thermoforming process.

The wheel arch liner according to the invention therefore has, on the one hand, improved noise damping compared to an injection-molded wheel arch liner. On the other hand, the flap (or cover) for widening the fender is also molded onto the wheel arch liner made of fleece material.

The core idea of the invention relates to the production of a fiber fleece wheel arch liner. However, the invention is not limited to the production of such a fiber fleece wheel arch liner. Rather, the core idea can also generally be applied to a method for producing any fiber fleece component that can be installed in a vehicle. Such a method is claimed in the independent claim 10.

Aspects of the invention are described in detail below: With a view to a simpler understanding of the invention, the following aspects of the invention are specifically described with reference to a fiber fleece wheel arch liner. However, the invention is by no means restricted to such a fiber fleece wheel arch liner. It is therefore understood that the following aspects can also be generally applied to the production of a fiber fleece component. Such a fiber fleece component has - instead of the shell body - a functional area that is hidden from view and - instead of the flap - a design area on the visible side.

To produce a wheel arch liner (or fiber fleece component) according to the invention, the nonwoven semifinished product is divided into a nonwoven semifinished product base section and a nonwoven semifinished product panel section (or nonwoven semifinished product design section) adjoining it in one piece and made of the same material. In the thermoforming process, the nonwoven semi-finished product base section is formed into the shell body of the wheel arch liner (or into the functional area of the nonwoven component that is hidden from view). The semi-finished fleece cover section is formed in the thermoforming process into a wheel arch liner flap (or the design area of the fiber fleece component on the visible side).

In a preferred process management, the thermoplastic fibers in the nonwoven semifinished product base section can only partially be melted in the thermoforming process, namely with the formation of a noise-dampening pore structure in the shell body of the wheel arch shell. In contrast, in the thermoforming process, the thermoplastic fibers in the nonwoven semifinished panel section can essentially be completely melted. This results in a cover made of a fiber-free solid thermoplastic material and a smooth component surface. Such a cover is significantly more dimensionally stable compared to the shell body of the wheel arch liner. In addition, their smooth component surface meets design requirements for exterior components of the vehicle.

In a technical implementation, the nonwoven semifinished product can consist of a fiber mixture which has thermoplastic structural fibers with a high melting point and thermoplastic matrix fibers with a low melting point. In this case, the thermoforming process can be implemented with the following process control: The nonwoven semifinished product base section can be heat-treated at a first process temperature at which the thermoplastic matrix fibers melt to form a matrix in which the non-melted thermoplastic structural fibers are embedded.

In contrast, the nonwoven semifinished panel section can be heat-treated at a process temperature at which both the thermoplastic matrix fibers and the thermoplastic structural fibers are melted. In this way, the cover is made of a fiber-free solid thermoplastic material with a smooth component surface.

The hot forming can be done in a thermoforming press. If necessary, the semifinished nonwoven product can be heat-treated in a heating station upstream of the thermoforming press. In an insertion step, the as yet undeformed and optionally heat-treated nonwoven semifinished product is inserted into an open tool cavity of the thermoforming press. When the mold cavity is closed, the nonwoven semi-finished product is hot formed into the wheel arch shell. The thermoforming press can have a heating zone specially assigned to the nonwoven semifinished panel section. By means of the heating zone, the nonwoven semifinished panel section can be heat-treated in the thermoforming press at a correspondingly high process temperature in order to achieve complete melting of the thermoplastic fibers. In contrast, the process temperature in the nonwoven semifinished product base section can be reduced.

As a result of the complete melting of the nonwoven semifinished panel section in the thermoforming process, there is greater material shrinkage there than in the nonwoven semifinished product base section. The comparatively large material shrinkage can impair the dimensional stability of the panel. With regard to adequate dimensional stability, it is therefore advantageous if the nonwoven semifinished panel section has a material thickening in comparison to the material thickness of the nonwoven semifinished product base section. This can preferably be achieved by means of a multilayer structure in the nonwoven semifinished panel section which has at least two nonwoven semifinished layers laid one on top of the other. In a manner that is simple in terms of manufacturing technology, it is preferred if the multi-layer structure is implemented by turning the nonwoven semi-finished product around at least one fold axis.

An exemplary embodiment of the invention is described below with reference to the accompanying figures.

• 1 in einer perspektivischen Teilansicht ein heckseitiger Kotflügel eines zweispurigen Fahrzeugs;
• 2 eine im Fahrzeug-Radhaus einbaubare Radlaufschale in Alleinstellung;
• 3 in einer Schnittdarstellung die Radlaufschale im Einbauzustand; sowie
• 4 bis 7 Ansichten, anhand derer die Prozessschritte zur Herstellung der Radlaufschale veranschaulicht sind.

Show it:

• 1 in a perspective partial view of a rear fender of a two-lane vehicle;
• 2 a single wheel arch liner that can be installed in the vehicle wheel arch;
• 3 in a sectional view the wheel arch liner in the installed state; such as
• 4th until 7th Views showing the process steps for manufacturing the wheel arch liner.

In the 1 is a rear area of a vehicle with a fender 1 shown. A lower edge of the fender 3 delimits a laterally outer wheel arch recess for a wheel arch 7th in which a vehicle wheel 9 is arranged. In the wheelhouse 7th is a wheel arch liner 11th assembled. This is in the 2 from one the vehicle wheel 9 curved shell body 13th and a flap (or cover) 15 constructed to widen the fenders. The aperture 15th is of the same material and in one piece on the shell body 13th the wheel arch liner 11th molded. The flap 15th towers over according to the 1 the edge of the fender 3 in the transverse direction of the vehicle y to the outside of the vehicle.

In the 3 is the material structure of the wheel arch liner 11th indicated. Accordingly, the shell body 13th the wheel arch liner 11th a pore structure that absorbs noise when driving, in the thermoplastic structural fibers 19th in a thermoplastic matrix 21 are embedded. In contrast to this, the panel formed thereon has 15th a fiber-free solid thermoplastic material 14th (in the 3 and 7th indicated with cross hatching) with a smooth component surface. The aperture 15th thus fulfills both design requirements and requirements with regard to dimensional stability.

The following are based on the 4th until 7th Process steps for the production of the 2 shown wheel arch liner 11th described: According to the 4th initially a flat nonwoven semi-finished product 17th provided, which consists of a fiber mixture of thermoplastic structural fibers 19th with a high melting point and made of thermoplastic matrix fibers 23 with a low melting point. The non-woven semi-finished product 17th is divided into a nonwoven semi-finished product base section 25th and in a non-woven semifinished panel section adjoining it in one piece and made of the same material 27 . In the non-woven semi-finished panel section 27 is the semi-finished fleece 17th around a folding axis F. ( 4th ) turned over, resulting in a two-layer structure consisting of two layers of non-woven semi-finished products placed one on top of the other. In this way, material shrinkage occurring in a thermoforming process in the nonwoven semifinished product base section can be avoided 27 be balanced. The non-woven semi-finished product 17th is in a heating station 31 ( 5 ) transferred. This is where the semi-finished fleece is made 17th heat-treated to a first process temperature at which the thermoplastic matrix fibers 23 to the thermoplastic matrix 21 melt. The thermoplastic structural fibers that have not been melted are in this 19th embedded.

The heat-treated non-woven semi-finished product 17th is placed in an open mold cavity when it is hot 33 ( 6th ) a tool press 35 inserted. By closing the mold cavity 33 hot forming takes place ( 7th ), in which the wheel arch liner 11th is shaped. As from the 6th and 7th is shown in the upper die half of the thermoforming press 35 a heating zone 37 integrated, specifically the nonwoven semi-finished panel section 27 assigned. By means of the heating zone 37 an additional heat input takes place in the nonwoven semifinished panel section 27 . In this way, the nonwoven semifinished panel section 27 Heat-treated in the closed thermoforming press at a process temperature that is higher than the melting point of the thermoplastic structural fibers 19th is. This causes the thermoplastic fibers to melt 19th , 23 in the nonwoven semi-finished panel section 27 completely open, removing the aperture 15th with the fiber-free thermoplastic solid material 14th is realized.

List of reference symbols

1

fender

3

Fender edge

7th

Wheel house

9

Vehicle wheel

11th

Wheel arch liner or fiber fleece component

13th

Shell body or functional area protected from view

14th

Solid thermoplastic material

15th

Cover for widening the fender or design area on the visible side

17th

Nonwoven semi-finished products

19th

Thermoplastic structural fibers

21

Thermoplastic matrix

23

Thermoplastic matrix fibers

25th

Non-woven semi-finished product base section

27

Non-woven semi-finished panel section

31

Heating station

33

Mold cavity

35

Thermoforming press

37

Heating zone

F.

Folding axis

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 202005015164 U1 [0004]
• DE 102018110246 A1 [0004]

Claims (12)

A method for producing a wheel arch shell (11) for a vehicle wheel arch (7), which has a shell body (13) and a cover (15) formed thereon for widening the fenders, the shell body (13) forming a functional area protected from view in the wheel arch shell installation position and the cover (15) forms a design area on the visible side, characterized in that the method has the following process steps: - providing a flat nonwoven semi-finished product (17) made of thermoplastic fibers (19, 23), and - hot forming of the nonwoven semi-finished product (17) into the wheel arch shell (11) in a thermoforming process. Procedure according to Claim 1 , characterized in that the nonwoven semifinished product (17) is divided into a nonwoven semifinished product base section (25) and a nonwoven semifinished product diaphragm section (27) adjoining it in one piece and made of the same material, and that in Thermoforming process the nonwoven semifinished product base section (25) forms the shell body (13) and the nonwoven semifinished product panel section (27) forms the panel (15). Procedure according to Claim 1 , characterized in that in the thermoforming process the thermoplastic fibers (19, 23) in the nonwoven semi-finished product base section (25) are partially melted, with the formation of a noise-dampening pore structure in the shell body (13) of the wheel arch shell (11), and / or that in the thermoforming process the Thermoplastic fibers (19, 23) are essentially completely melted in the nonwoven semifinished panel section (27), to be precise with the formation of a fiber-free thermoplastic solid material (14) with a smooth component surface. Procedure according to Claim 1 or 2 , characterized in that the nonwoven semifinished product (17) consists of a fiber mixture of thermoplastic structural fibers (19) with a high melting point and thermoplastic matrix fibers (23) with a low melting point, and that in the thermoforming process of the nonwoven semifinished product base section (25) at a process temperature is heat-treated, in which the thermoplastic matrix fibers (23) melt to form a matrix (21) in which the non-melted thermoplastic structural fibers (19) are embedded. Procedure according to Claim 3 , characterized in that in the thermoforming process the non-woven semifinished panel section (27) is heat-treated at a process temperature at which both the thermoplastic matrix fibers (23) and the thermoplastic structural fibers (19) melt. Method according to one of the preceding claims, characterized in that the nonwoven semifinished panel section (27) has a material thickening compared to the material thickness of the nonwoven semifinished product base section (25). Procedure according to Claim 6 , characterized in that, in order to produce the material thickening, the nonwoven semifinished product panel section (27) has a multilayer structure with at least two nonwoven semifinished product layers placed one on top of the other. Procedure according to Claim 7 , characterized in that the multi-layer structure takes place by turning over the nonwoven semi-finished product (17). Method according to one of the preceding claims, characterized in that the hot forming takes place in a thermoforming press (35), and that the nonwoven semifinished product (17) is inserted in an inserting step into an open tool cavity (33) of the thermoforming press (35), and that with the Closing the tool cavity (33), the hot forming takes place, and that in particular the thermoforming press (35) has a heating zone (37) assigned to the nonwoven semifinished panel section (27), by means of which the nonwoven semifinished panel section (27) is heat-treated at a process temperature that is greater than than the process temperature in the nonwoven semi-finished product base section (25). Method for producing a fiber fleece component (11) for installation in a vehicle, wherein the fiber fleece component (11) is divided into a functional area (13) which is hidden from view in the installation position and a visible design area (15) formed thereon, characterized in that the method comprises the following process steps: - providing a flat nonwoven semifinished product (17) made of thermoplastic fibers (19, 23), and - hot forming of the nonwoven semifinished product (17) into the nonwoven component (11) in a thermoforming process. A fiber fleece component, in particular a wheel arch liner, produced with a method according to one of the preceding claims. Process arrangement for performing a method according to one of the Claims 1 until 10 .

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