Attachment part for connecting to a structural part

Abstract

An attachment part for connecting to a structural part. The attachment part has an attachment part longitudinal axis, and a weld portion to be welded to the structural part by torsional ultrasonic welding. The weld portion has a contact surface for contact with a torsion sonotrode, and a weld surface for connecting to the structural part. The weld portion is delimited, at least portionally, by an inner vibration decoupling zone. The inner vibration decoupling zone, at least portionally, surrounds an inner portion of the attachment part.

Claims

1. An attachment part for connecting to a structural part, wherein the attachment part has an attachment part longitudinal axis, and a weld portion to be welded to the structural part by torsional ultrasonic welding, the weld portion has a contact surface for contact with a torsion sonotrode, and a weld surface for connecting to the structural part, and the weld portion is delimited, at least portionally, by an inner vibration decoupling zone, and the inner vibration decoupling zone, at least portionally, surrounds an inner portion of the attachment part.

2. The attachment part as claimed in claim 1, wherein the inner vibration decoupling zone is inclined, at least portionally, in relation to the attachment part longitudinal axis or is parallel thereto.

3. The attachment part as claimed in claim 1, wherein the inner vibration decoupling zone is realized substantially in a form of a conical surface.

4. The attachment part as claimed in claim 1, wherein the inner vibration decoupling zone extends at an angle, in relation to the attachment part longitudinal axis, and the angle is in the range from 3° to 35°.

5. The attachment part as claimed in claim 1, wherein the inner attachment part portion has a through-hole arranged concentrically in relation to the attachment part longitudinal axis.

6. The attachment part as claimed claim 1, wherein the inner attachment part portion has a plurality of fastening portions, arranged concentrically with respect to the attachment part longitudinal axis, for fastening a functional part realized to correspond to the fastening portions.

7. The attachment part as claimed in claim 1, wherein the weld portion is surrounded, at least portionally, by an outer vibration decoupling zone.

8. The attachment part as claimed in claim 1, wherein the inner vibration decoupling zone and/or the outer vibration decoupling zone are/is formed by a multiplicity of decoupling openings and/or by one or more thinned regions of material.

9. The attachment part as claimed in claim 1, wherein the weld surface is formed by at least one rib extending from the weld portion.

10. The attachment part as claimed in claim 1, wherein the attachment part comprises a plastic.

11. A method for connecting an attachment part, as claimed in claim 1, to a structural part, the method comprising the following steps: a) bringing the weld surface of the attachment part into contact with a weld region of the structural part, b) exerting a force upon the contact surface by a torsion sonotrode, such that the weld surface is pressed against the weld region, and c) introducing a torsional ultrasonic vibration into the weld portion by the torsion sonotrode such that the weld surface becomes welded to the weld region.

12. The method as claimed in claim 11, wherein, before step b), at least a part of the structural part is deformed, by action of the torsion sonotrode, in such a manner that the torsion sonotrode can be brought into contact with the contact surface.

13. The method as claimed in claim 11, wherein the torsion sonotrode has a cavity for at least partially receiving the attachment part during step c), and the cavity is circumferentially delimited by a wall, the outer side of which widens, at least portionally, in a direction of a sonotrode longitudinal axis and away from a work surface of the torsion sonotrode.

14. The method as claimed in claim 11, wherein the torsion sonotrode has a sonotrode longitudinal axis and, before step c), the sonotrode longitudinal axis is arranged, at least temporarily, at an angle in relation to the attachment part longitudinal axis.

15. The method as claimed in claim 11, wherein the structural part is an external or internal facing part of a motor vehicle.

16. A composite part including the attachment part, as claimed in claim 1 and a structural part, wherein the weld surface is welded to a weld region of the structural part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in greater detail in the following of exemplary embodiments and drawings. Shown therein

(2) FIG. 1: a perspective view of an attachment part according to the invention;

(3) FIG. 2: a side view of the attachment part;

(4) FIG. 3: a top view of the attachment part;

(5) FIG. 4: a bottom view of the attachment part;

(6) FIG. 5: a method according to the invention for connecting the attachment part to a bumper, at a first time-point;

(7) FIG. 6: a method according to the invention, at a subsequent, second time-point.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(8) The attachment part 10 represented in FIGS. 1 to 4, which is composed, for example, of a plastic, and which may be produced by an injection molding process, includes a weld portion 11 for contact with a torsion sonotrode 70 (for which see FIGS. 5 and 6). The weld portion 11 is oriented perpendicularly in relation to an attachment part longitudinal axis A, and has a contact surface 12, realized substantially in the form of a ring, for contact with the torsion sonotrode 70. Opposite the contact surface 12 there is a weld surface for connection to a structural part (for which see also FIGS. 5 and 6). The weld surface is formed by a rib 13 extending from the weld portion 11.

(9) The weld portion 11 is delimited inwardly by an inner vibration decoupling zone 14, and surrounded outwardly, in portions, by an outer vibration decoupling zone 18, which in turn is surrounded portionally by an outer attachment part portion 21. The weld portion 11 and the outer attachment part portion 21 form an, in particular flat, common flat plate. The inner vibration decoupling zone 14 is inclined in relation to the attachment part longitudinal axis A. More precisely, it is realized substantially in the form of a conical surface, and extends at an angle α in relation to the attachment part longitudinal axis A, which angle may be in the range of from 3° to 35°. This inclination has the advantage that, for a predefined inner diameter of the inner vibration decoupling zone 14, a smaller outer diameter of the inner vibration decoupling zone 14 can be achieved. Conversely, for a predefined outer diameter of the inner vibration decoupling zone 14, the selected inner diameter of the inner vibration decoupling zone 14 can be larger.

(10) The inner vibration decoupling zone 14 surrounds an inner attachment part portion 15, which has a through-hole 16 arranged concentrically in relation to the attachment part longitudinal axis Al. The inner attachment part portion 15 has a plurality of fastening portions in the form of holding and latching lugs 17, arranged concentrically with respect to the attachment part longitudinal axis A, for fastening a functional part, for example a distance sensor, realized to correspond to the holding and latching lugs 17.

(11) The inner vibration decoupling zone 14 and the outer vibration decoupling zone 18 are formed by a multiplicity of adjacently arranged, oval vibration decoupling zone 19 and 20, respectively. The through holes 20 each form segment-shaped zones, concentrically with respect to the attachment part longitudinal axis A.

(12) In the direction of the attachment part longitudinal axis A, the attachment part 10 has a height h=25 mm, and perpendicularly in relation to the attachment part longitudinal axis A has an extent a=35 mm. The weld portion 11 has a thickness d=1.0 mm. The attachment part 10 is comparatively small and light, and not very stiff, thereby making it possible to prevent unwanted distortions on a bumper 30.

(13) FIG. 5 shows a part of a method according to the invention for producing an ultrasonic weld connection of the attachment part 10, as claimed in FIGS. 1 to 4, to a bumper 30, at a first time-point.

(14) A torsion sonotrode 70 used for welding includes a sonotrode longitudinal axis S that coincides with the torsion axis of the torsional vibrations effected by it. It additionally includes a work surface 71, which is flat and realized in the form of a ring, and which is perpendicular to the sonotrode longitudinal axis S. Furthermore, it includes a cavity 72. The cavity 72 is delimited circumferentially by a wall 73, the outer side 74 of which widens in the direction of the sonotrode longitudinal axis S and away from the work surface 71, in portions.

(15) To produce the ultrasonic weld connection, in a step a) the attachment part 10 is placed onto the bumper 30 in such a manner that the weld surface of the attachment part 10 is in contact with a weld region 31 of the bumper 30.

(16) Then, in a step b), a part of the bumper 30 is deformed by action of the torsion sonotrode 70 in such a manner that the torsion sonotrode 70 can be brought into contact with the contact surface 12 (see FIG. 5). The sonotrode longitudinal axis S in this case is arranged at an angle β in relation to the attachment part longitudinal axis A, which angle is preferably less than 20°. By means of the torsion sonotrode 70, a force is then exerted upon the contact surface 12, such that the weld surface is pressed fully against the weld region 31.

(17) Subsequently, in a step c) represented in FIG. 6, a torsional ultrasonic vibration is introduced into the weld portion 11 by means of the torsion sonotrode 70, as a result of which the weld surface becomes welded to the weld region 31. In this case, the attachment part longitudinal axis A and the sonotrode longitudinal axis S coincide, the attachment part 10 is partially accommodated in the cavity 72, and the outer attachment part portion 21 lies on an inner surface 33 of the bumper 30.

(18) Obtained by this method is a composite part 90 according to the invention that is composed of the bumper 30 and the attachment part 10 connected thereto. A distance sensor can be fastened to the attachment part 10, and thus indirectly to the bumper 30, by means of the holding and latching lugs 17.