Receptacle for a towing means and method of manufacture

Abstract

An arrangement is proposed of a receptacle consisting of multiple components for a towing means, especially a towing lug, on a support piece (1) attachable to the body of a motor vehicle, wherein the support piece is insertable into a receptacle on a cross member of the vehicle, and the support piece is to be joined with the cross member via friction-stir welds.

Claims

1. An arrangement of a towing receptacle for a vehicle body comprising: a cross member defining an interior cavity and having an inner front surface and an inner rear surface; a support piece disposed in the interior cavity and attached to the cross member by friction-stir welding; the support piece including a front support surface disposed flush with the inner front surface of the cross member and a rear support surface disposed flush with the inner rear surface of the cross member; a first borehole extending through both of the cross member and the support piece from the respective front to rear surfaces; and a towing sleeve disposed in the first borehole.

2. An arrangement according to claim 1, wherein the support piece extends along an axis A-A between a first support end and a second support end, and each support end defining at least one of catches or hook-shaped projections.

3. An arrangement according to claim 2, wherein the support piece defines at least one second borehole extending through the support piece transverse to the axis A-A for the attachment of a crash box to the cross member.

4. An arrangement according to claim 3, wherein the at least one second borehole is disposed between the towing sleeve and a respective support end of the support piece.

5. An arrangement according to claim 1, wherein the support piece has an extruded profile.

6. An arrangement according to claim 5, wherein the support piece is comprised of aluminum.

7. An arrangement according to claim 5, wherein the support piece is comprised of magnesium.

8. A method for manufacture of a towing arrangement for a vehicle body, the method comprising: inserting a support piece into an interior cavity of a cross member of the vehicle body; caulking the support piece into the cross member; attaching the inserted support piece to the cross member by friction-stir welding; drilling a first borehole through the cross member and the support piece; and inserting a towing sleeve into the first borehole.

9. A method according to claim 8, further comprising: bending the cross member into a bent end form before or after the support piece is welded to the cross member.

10. A method according to claim 8, wherein said attaching step includes attaching the inserted support piece to the cross member with at least two friction-stir weld points.

11. A method according to claim 8, further comprising: equipping the support piece with at least one second borehole extending perpendicular to the first borehole for the attachment of a crash box to the cross member.

12. A method according to claim 8, wherein the support piece extends along an axis A-A between a first support end and a second support end each defining at least one of catches or hook-shaped projections, and wherein the step of inserting the support piece includes sliding the support piece into the cross member using the catches or hook-shaped projections.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in what follows in exemplary fashion, with reference to the appended drawing.

(2) FIG. 1 is a schematic depiction of the exemplary embodiment form at the installation location.

(3) FIG. 2 shows a cross section along the axis A-A.

(4) FIG. 3 shows a cross section along the axis B-B.

DETAILED DESCRIPTION OF THE DRAWINGS

(5) FIG. 1 shows a cutout from a cross member 2, which is already bent in bowed fashion in this depiction.

(6) As is shown in FIG. 1 the cross member exhibits at least one interior cavity 10. A support piece 1 is inserted into this cavity 10. The support piece is designed as an extruded profile. In this process, at no expense, details may be integrated such as a T-groove or projecting flanks for reducing rigidity discontinuities. In the chosen embodiment example, a catch 6 and hooklike arrangements 7 are perceptible on the support piece, especially in FIG. 2.

(7) Also shown in FIG. 1 is a towing sleeve 3 in the already completely assembled support piece 1. The reference symbols 5 designate friction-stir weld points, which are to be placed to the left and right of the towing sleeve 3 to produce a connection with the cross member 2.

(8) Friction-stir welding is a known process for the joining of materials. The rotating pin and sleeve tools are placed at the point of connection. The heat thereby produced converts the material into a plastifiable, non-fusible state. The rotating sleeve penetrates into the doughy material. Simultaneously the inner pin is withdrawn from the tool; a cavity is produced. This resulting cavity admits the displaced volume. The stamp lies flat on the material surface; material is prevented from escaping in uncontrolled fashion. The sleeve penetrates through the upper sheet and reaches the lower layer.

(9) During the retrograde movement, the sleeve is withdrawn from the joint zone.

(10) At the same time the pin compresses the plastic material back into the joining area; the cavity is again filled. By a brief resetting of the tools, the material becomes fixed. A material-locking, point-shaped and flat-configured connection is achieved.

(11) FIG. 2 shows a cross section along the section line A-A. The support piece 1 sits flush in a receptacle in a cavity 10 of cross member 2. Via the friction-stir weld points 5, the two components are connected to each other. A borehole 8 generates a through-running opening through both of the components, to admit a towing sleeve 3.

(12) FIG. 3 shows a cross section through the line B-B. As shown in FIG. 3 a borehole 9 is provided for admitting a crash box. The crash box is not depicted in this drawing and would be located beneath the cross member 2. That the support piece is not screw-connected with the cross member, but rather via weld locations to be positioned as desired, poses no problem for placement of the boreholes 9 for a crash box potentially to be attached. The material of support piece 1 offers a spacer 4 for the through-running borehole.

(13) The optimized manufacturing process for the cross member with the arrangement for a towing lug derives from extruded profiles. The cross member, and also the support piece itself, is manufactured from such an extruded profile.

(14) The support pieces are produced from aluminum or magnesium extruded profiles. Alternatively, the support piece can also be made using a casting process.

(15) In the manufacturing process, the two components are fitted together, and the support piece is caulked into the cross member. The next manufacturing step then is either joining of the components by welding and connection of the component combination into the desired form. The two final manufacturing steps can also be done in reverse: the component combination is then first bent, and only then is the support piece welded to the cross member.

(16) Only after the welding and after the bending, are boreholes and apertures mechanically milled, and the requisite threadings cut. The additional steps in assembly of a cross member then proceed as already described in the prior art.

LIST OF REFERENCE SYMBOLS

(17) 1 Support piece 2 Cross member 3 Towing sleeve 4 Spacer piece 5 Friction stir point 6 Catch 7 Hooklike arrangement 8 Borehole for towing lug 9 Borehole for crash box 10 Internal cavity