WO2011144663A1

WO2011144663A1 - Method for producing a steering wheel for a motor vehicle

Info

Publication number: WO2011144663A1
Application number: PCT/EP2011/058054
Authority: WO
Inventors: Claus Rudolf; Norbert Müller; Martin Sauer; Jürgen KOLB; Bernhard Kempf; Andreas Hans; Achim Hartlaub
Original assignee: Takata-Petri Ag
Priority date: 2010-05-20
Filing date: 2011-05-18
Publication date: 2011-11-24
Also published as: DE102010029188A1

Abstract

The invention relates to a method for producing a steering wheel for a motor vehicle, with the following steps: - providing a steering wheel skeleton (1); - covering at least one section of the steering wheel skeleton (1) with a steering wheel cover (2) which forms an outer layer of the steering wheel in the finished steering wheel; and - filling the steering wheel cover (2) with a cladding material (4) such that the cladding material at least partially surrounds the steering wheel skeleton (1).

Description

Method for producing a steering wheel for a motor vehicle

description

The invention relates to a method for producing a steering wheel for a motor vehicle according to claim 1. Steering wheels for motor vehicles are known from the prior art, which have a steering wheel skeleton in the form of a metal structure, which is surrounded by a jacket material, which defines in particular the shape of the steering wheel. The jacket material is, for example, a foam, in particular a polyurethane foam (PU foam), wherein the foam can in turn be coated with a coating, in particular a leather covering, which forms an outer, visible layer of the steering wheel. However, coating the foam with such a coating is difficult and must be done largely by hand.

The problem underlying the invention of the invention is to provide a method which enables the simplest possible and cost-effective production of a steering wheel for a vehicle.

This problem is solved by the method with the features according to claim 1. Further developments of the invention are specified in the dependent claims.

Thereafter, a method of manufacturing a steering wheel for a motor vehicle (or other vehicle) is provided, comprising the steps of:

- Providing a steering wheel skeleton;

Wrapping at least a portion of the steering wheel skeleton with a steering wheel cover which forms an outer layer of the steering wheel in the finished steering wheel; and - Filling the steering wheel cover with a jacket material, so that the jacket material surrounds the steering wheel skeleton, at least in sections.

According to the invention, therefore, not as in the conventional production of a steering wheel, the steering wheel skeleton initially surrounded with the jacket material and then covered with a steering wheel cover (cover), but it is initially arranged the steering wheel cover, which is then filled with the jacket material. The steering wheel cover thus serves as a kind of shape for the jacket material, wherein the wrapping of the steering wheel skeleton with the steering wheel trim is done so that it does not lie close to the steering wheel skeleton, but forms an inner volume that extends around the steering wheel skeleton.

In particular, the jacket material comprises a foam or is formed from a foam, so that the step of filling the steering wheel cover comprises foaming the steering wheel cover with the foam. In particular, the foam is a polyurethane foam. It can be used as sheath material, of course, another foam material or a non-foam plastic or synthetic resin, which is suitable to realize the desired (especially geometric and haptic) properties of the steering wheel.

In particular, the steering wheel cover is made from a blank of a flexible and / or flexible material, i. a flat, flexible piece of material, in particular made of leather. A design of the steering wheel cover leather is not mandatory, but it is also possible that a sheet of plastic material or other material is selected as the material for the steering wheel cover.

After wrapping the steering wheel skeleton (in particular a steering wheel rim of the steering wheel skeleton) with the steering wheel trim, for example, sections (in particular edge sections) of the steering wheel trim are connected to one another in order to close the steering wheel trim wrapped around the steering wheel skeleton. The connection of the sections of the steering wheel trim is effected for example via a zipper, a Velcro closure or by tacking, gluing and / or sewing. In particular, a steering wheel cover in the form of a one-piece material blank is wrapped around the steering wheel skeleton and sections of the material blank are joined together, in particular edge sections extending along at least a portion of an edge of the Blank extend. Of course, it is also possible that the steering wheel cover consists of a plurality of pieces of material (blanks), which are connected to each other so that the steering wheel cover the steering wheel skeleton envelops and can be filled with the jacket material.

By "closing" the steering wheel cowling, at least a portion of a steering wheel rim defined by the steering wheel skeleton, which extends around the steering axis in the mounted state of the steering wheel, is completely surrounded by the steering wheel fairing In other words, the steering wheel rim is at least in a partial section of its around the steering axis extending circumferentially (which lies in the main plane of extension of the steering wheel) completely enveloped, ie in this section, the steering wheel trim extends along the entire circumference of a cross section of the steering wheel rim, which is oriented perpendicular to the running around the steering axis circumference (parallel to the steering axis).

According to the invention, the closure of the steering wheel cover, i. connecting the portions of the steering wheel trim, prior to surrounding the steering wheel skeleton with the jacket material (i.e., in particular, prior to foaming the steering wheel skeleton). This has e.g. the advantage that the closing of the steering wheel cover can be predominantly or exclusively by machine and does not need to be carried out predominantly by hand, as for example no complex positioning of the steering wheel cover (the material blank) on an existing jacket material (in particular a foam) is necessary. Thus, e.g. Errors when connecting the material sections are avoided and a uniform quality of the connection can be achieved. Furthermore, it is also not necessary to stick the steering wheel cover by means of an additional adhesive on the jacket material, since the jacket material (in particular, if this has a PU foam) during filling of the steering wheel cover has a sufficiently high adhesiveness. Due to the possible omission of an additional, solvent-based adhesive, for example, the emergence of health-damaging vapors due to solvents of the adhesive can be avoided.

The steering wheel skeleton comprises (as known in principle from the prior art) in particular a centrally arranged steering wheel hub, which is connected via a plurality of steering wheel spokes with a steering wheel rim over which the steering wheel is to be actuated. The The steering wheel cover can encase the complete steering wheel skeleton, ie the steering wheel hub, spokes and steering wheel rim. However, it is also conceivable that the steering wheel cover encloses only a part of the steering wheel skeleton, eg only the steering wheel rim or sections of the steering wheel rim, and thus the jacket material also extends only over this part of the steering wheel skeleton. However, it is of course conceivable that in this case, the steering wheel cover and thus the jacket material extends completely around the steering wheel skeleton, ie viewed in cross-section, completely surrounds the steering wheel skeleton.

For example, the steering wheel skeleton enveloped with the steering wheel trim is inserted into a filling mold before filling with the jacket material and the filling of the steering wheel trim with the wrapped steering wheel skeleton inserted into the mold is carried out. In particular, the filling has a corresponding recess for the steering wheel skeleton with the steering wheel cover. In particular, it is conceivable that the steering wheel cover is formed from a material blank, wherein edge portions (in particular along the extending around the steering axis circumference of the steering wheel rim of the steering wheel skeleton) of the material blank are joined together before inserting the steering wheel skeleton in the Befüllform to close the steering wheel cover as explained above. For example, the Befüllform comprises two half-shells, each having corresponding recesses for receiving the wrapped steering wheel skeleton, wherein the steering wheel skeleton is inserted into the recess of a half-shell and covered with the other half-shell. For filling the enveloped steering wheel skeleton inserted in the filling mold, the filling mold has e.g. a filling channel through which the jacket material is directed into the steering wheel cover. In particular, the steering wheel cover has an opening through which the jacket material can be brought into the interior of the steering wheel cover, wherein the filling channel opens in particular in this opening of the steering wheel cover or at least has an outlet opening which is aligned with the opening of the steering wheel cover.

It is possible that the filling channel extends from an outer side of the filling mold to the recess in which the coated steering wheel skeleton is to be arranged, ie the filling channel has in its one end an outer opening of the filling mold formed in the outer opening and in the other End of a formed in a side wall of the recess outlet opening. For example, the filling channel extends, if the Filling mold is formed by two adjoining half shells, only in one of the two half-shells.

In particular, the opening of the steering wheel cover, via which the jacket material can be filled in the steering wheel cover, formed in the region of a spoke of the steering wheel, so that, for example, a sprue of the jacket material, which arises when filling the steering wheel cover outside of the steering wheel cover, an integral part of the steering wheel spoke can form. In particular, the opening of the steering wheel cover is here arranged so that it overlaps with the portion of the steering wheel skeleton which forms the spoke of the steering wheel.

In addition, the opening for filling the steering wheel cover in a range of interconnected portions of the steering wheel trim wrapped around the steering wheel skeleton (which, as mentioned, may consist of one or more pieces of material) may be formed. For example, the opening is formed as an interruption of the connection between the portions of the steering wheel trim, in particular as an interruption (for example, 1-10 mm, especially about 5 mm wide) of a seam or seam by which the portions of the steering wheel trim are connected together. The steering wheel trim can also tightly wrap the steering wheel skeleton, i. In particular, the connection of portions of the steering wheel cover can be made so tight that when filling the steering wheel cover with the jacket material substantially no jacket material can escape through the connecting region between the sections of the steering wheel trim through to the outside.

The invention will be explained in more detail below with reference to an embodiment with reference to the figures. The figure shows schematically a section through a steering wheel rim during the manufacture of a steering wheel according to an embodiment of the method according to the invention.

Thereafter, a steering wheel skeleton 1, which has an at least approximately U- or V-shaped cross section, at least in the region of the steering wheel rim with a steering wheel cover wrapped in the form of a leather suit 2. After the steering wheel garment 2 has been wrapped around the steering wheel skeleton 1, two edge sections 21, 22 of the leather garment 2 have been connected to each other (glued or sewn, for example) in order to close the steering wheel garment 2. According to the figure, the arrangement of the steering wheel skeleton 1 and the steering wheel garment 2 is arranged in a recess 31 1 of a first half shell 31 of a filling mold 3, wherein the recess 31 1 is designed in the shape of the steering wheel skeleton 1 approximately half-torus-shaped. The first half-shell 31 1 is covered with a second half-shell 32 of the filling mold 3, which has a corresponding recess 312. The second half-shell 32 also has a filling channel 322 which forms an outwardly funnel-shaped widening filler opening 323 in an outer side of the half-shell 32 and extends through the second half-shell 32 as far as an opening 23 of the leather covering 2. The opening 23 in the leather garment 2 is realized in particular as an interruption of an adhesive seam or sewing seam between the edge sections 21, 22 of the leather garment 2 (designed in the form of a material blank).

Via the filling channel 322, the interior of the leather garment 2 is foamed with a jacket material 4 such that the jacket material surrounds the steering wheel skeleton 1, whereby in particular the desired shape (for example the desired diameter) of the steering wheel is created. The sheath material 4 spreads during opening of the steering wheel garment 2 from the opening 23 around the steering wheel skeleton 1 (indicated by arrows) until it completely surrounds the steering wheel skeleton, viewed in cross-section (ie in the plane of the figure). In particular, the adhesive force of the jacket material 4 filled in the leather garment 2 is sufficient to connect the jacket material 4 to the leather garment 2, so that a firm arrangement consisting of the steering wheel skeleton 1, the jacket material 4 and the leather garment (leather cover) 2 is produced without an additional adhesive is required. In the example of the figure, the filling channel 322 opens immediately in front of the opening 23 of the leather garment 2, so that an outlet opening of the filling channel is aligned with the opening 23. However, it is also conceivable that the filling channel is indeed formed in the form of a passage through one of the two half-shells 31, 32, but has a small projection, which through the opening 23 of the leather garment 2 through a piece in the Inside the leather dress 2 protrudes to achieve the most efficient filling of the leather dress 2.

It is also conceivable that a separate filling means (for example a hose or a cannula) is introduced through the filling channel 322, which pushed through the filling channel 322 to the opening 23 or through the opening 23 into the interior of the leather garment 2 becomes.

After the leather garment 2 has been filled, ie when the inner volume of the leather garment 2 surrounding the steering wheel skeleton 1 has been completely filled, the two half shells 31, 32 are removed and, if appropriate, a remainder of the jacket material (eg foam residue) formed in the region of the filling channel 322 is removed ,

LIST OF REFERENCE NUMBERS

1 steering wheel skeleton

2 leather dress

3 filling form

4 sheath material 21,22 edge portion 23 opening

31.32 half shell

311 first recess 321 second recess

Claims

claims

1 . Method for producing a steering wheel for a motor vehicle, comprising the steps:

- Providing a steering wheel skeleton (1);

- Encasing at least a portion of the steering wheel skeleton (1) with a steering wheel cover (2), which forms an externa ßere layer of the steering wheel in the finished manufactured steering wheel; and

- Filling the steering wheel cover (2) with a jacket material (4), so that the jacket material surrounds the steering wheel skeleton (1) at least in sections.

2. The method according to claim 1, characterized in that the steering wheel cover (2) is formed of leather.

3. The method according to claim 1 or 2, characterized in that the Lenkradver- clothing (2) is formed from a blank of a flexurally soft and / or flexible material.

4. The method according to any one of the preceding claims, characterized in that portions (21, 22) of the steering wheel cover (2) after wrapping the steering wheel skeleton (1) are interconnected.

5. The method according to claim 4, characterized in that the joining of the sections (21, 22) by means of a zipper, a hook and loop fastener, by tacking, gluing and / or sewing takes place.

6. The method according to any one of the preceding claims, characterized in that the jacket material (4) is a foam and the filling of the steering wheel cover (2) comprises a foaming of the steering wheel cover (2) with the foam.

7. The method according to any one of the preceding claims, characterized in that with the steering wheel cover (2) wrapped steering wheel skeleton (1) inserted into a Befüllform (3) and the filling of the steering wheel cover (2) with the in the filling (3) inserted steering wheel skeleton (1) is performed.

8. The method according to claim 7, characterized in that the filling mold (3) has a filling channel (322) through which the jacket material (4) in an inner volume of the steering wheel cover (4) is passed.

9. The method according to any one of the preceding claims, characterized in that the filling of the steering wheel cover (2) with the jacket material (4) via an opening (23) in the steering wheel sheathing (2).

10. The method according to claim 9, characterized in that the opening (23) in the region of a spoke of the steering wheel skeleton (1) is arranged.

1 1. A method according to claim 4 and 9, characterized in that the opening (23) between the interconnected portions of the steering wheel cover (2) is formed.

12. The method according to any one of the preceding claims, characterized in that the steering wheel cover (2) is formed so that it tightly surrounds the steering wheel skeleton (1).

13. The method according to any one of the preceding claims, characterized in that the steering wheel cover (2) is filled with the jacket material (4) that it completely surrounds the steering wheel skeleton (1) viewed in cross section.

14. The method according to any one of the preceding claims, characterized in that the steering wheel cover (2) is wrapped around the steering wheel skeleton (2) and before filling the steering wheel cover (2) with the jacket material (4) edge portions (21, 22) of the steering wheel cover ( 2) are joined together to close the steering wheel cover (2).