Fastening arrangement

Abstract

A fastening arrangement having a fastening element for elastically connecting a bolt-on part to a support part. The fastening element has a head section (7) that transitions into an element shank. An elastomer profile part with a retaining groove which is open radially to the outside, into which a retaining foot of the bolt-on part can engage, is arranged on the underside of the head section. The retaining groove is designed with a groove wall on the head side and a groove wall on the shank side. The elastomer profile part is constructed in at least two parts from an elastomer body arranged on the head section of the fastening element and from a disk element that has at least the shank-side groove wall of the retaining groove. The disk element is also composed of two components, namely the elastomer profile part and the hard component.

Claims

1. A fastening arrangement comprising: a fastening element to elastically connect a bolt-on part to a support part or a panel, the fastening element having a head section that transitions into an element shank; and an elastomer profile part with a retaining groove that is open radially to an outside, into which a retaining foot of the bolt-on part is adapted to engage, is arranged on an underside of the head section, wherein the retaining groove has a groove wall on the head side and a groove wall on a shank side with a groove bottom located therebetween, wherein the elastomer profile part is constructed in at least two parts from that include an elastomer body and a disk element, wherein the elastomer body is arranged on the head section of the fastening element and includes the head side groove wall and the groove bottom, the groove bottom protruding from a surface of the head side groove wall in a direction towards the shank side groove wall, and wherein the disk element includes the shank side groove wall.

2. The fastening arrangement according to claim 1, wherein in a final assembly position, the head section presses the elastomer profile part against the panel with elastic preloading so that the retaining foot of the bolt-on part is elastically preloaded.

3. The fastening arrangement according to claim 1, wherein the disk element is supported on the element shank so as to be axially movable through a motion clearance.

4. The fastening arrangement according to claim 3, wherein at least one axial rib projects axially from an inner perimeter of the disk element, the at least one axial rib being guided in an axial groove located in the groove bottom of the retaining groove so as to be axially movable but rotationally fixed, and wherein the axial groove is designed as a discontinuity in an elastomer material of the elastomer body.

5. The fastening arrangement according to claim 4, wherein the axial groove located in the groove bottom of the retaining groove terminates on the head side with an axial stop that limits an axial movement of the disk element toward the head section.

6. The fastening arrangement according to claim 5, wherein, in a final assembly position, the axial rib of the disk element is guided into pressure contact with the axial stop of the fastening element on which the disk element is supported, utilizing the motion clearance in order to press the support part against an upper side of a mounting boss of the element shank with a predefined clamping force, and wherein the motion clearance is greater than 0.

7. The fastening arrangement according to claim 1, wherein the disk element is secured on the fastening element by a retaining device, and wherein the retaining device includes a latching rib formed on an inner perimeter of the disk element and an axial groove formed on an outer perimeter of the element shank, wherein the latching rib projects into the axial groove.

8. The fastening arrangement according to claim 1, wherein the disk element is designed as a two-component part that includes the shank-side groove wall that is made of an elastomer material, and a second component that faces a shank tip and is supported on the support part in a final assembly position, wherein the second component is formed of a harder material than the shank-side groove wall.

9. The fastening arrangement according to claim 1, wherein the fastening element has, on the shank tip of the element shank, at least one mounting boss that projects radially outward from the element shank and engages with an opening of the support part, and wherein an edge region of the opening of the support part is clamped between the disk element and an upper side of the at least one mounting boss in a final assembly position by the axial preloading.

10. The fastening arrangement according to claim 1, wherein the head side groove wall and the groove bottom are formed as a single, monolithic element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIGS. 1 and 2 show different side views of a fastening element;

(3) FIG. 3 shows the fastening element in an exploded view with disk element removed;

(4) FIGS. 4 and 5 show different sectional representations of the fastening element; and

(5) FIGS. 6 to 11 show views aiding the visualization of a process sequence for the assembly of a bolt-on part with a panel.

DETAILED DESCRIPTION

(6) A fastening element 1 is shown in different views in FIGS. 1 to 3. With the aid of the fastening element 1, a bolt-on part 3 can be elastically connected to a body panel 5, as is indicated in FIG. 11. The fastening element 1, made of plastic, has an enlarged head section 7, which transitions into an element shank 9. Mounting bosses 11, 12, which project radially outward from the element shank 9, are formed in the region of an element shank tip. In addition, an elastomer profile part 13, with retaining groove 15 that is open radially to the outside, is arranged on the underside of the head section 7. A retaining foot 17 of the bolt-on part 3 can engage in the retaining groove 15. As is evident from FIG. 4 or 5, the retaining groove 15 is designed with a groove wall 19 on the head side, a groove wall 21 on the shank side, as well as a radially inner groove bottom 23.

(7) According to FIGS. 3-5, the elastomer profile part 13 is not made of a single material and as a single piece, but instead is constructed in two parts, namely with an elastomer body 25 arranged on the head section 7 of the fastening element 1, and with a disk element 27. The disk element 27 in FIGS. 4 and 5 is implemented as a two-component part, namely with the groove wall 21 made of elastomer material on the shank side, which constitutes the soft component, and a hard component 29 that faces the shank tip and is supported on the panel 5 in the final assembled state. In contrast, the groove wall 19 on the head side and the radially inner groove bottom 23 are formed in the elastomer body 25.

(8) The disk element 27 is supported on the element shank 9 by means of an axial guide so as to be axially movable through a motion clearance a (FIG. 4). In this way, the disk element 27 can be moved easily in the axial direction in order to set a groove width b (FIG. 4) between the two opposite groove walls 19, 21.

(9) In accordance with FIG. 3, the axial guide has the diametrically opposing axial ribs 33 formed on the inner perimeter of the disk element 27, which project axially by an axial rib height h (FIG. 4) from the inner perimeter of the disk element 27. It must be emphasized that each axial rib 33 is constructed in two parts, from the hard component 29 as well as from the elastomer material of the groove wall 21 on the shank side, as is evident from FIG. 4.

(10) According to FIG. 3, the elastomer body 25 is fixed in position between the underside of the head section 7 and a collar 35 (FIG. 3) formed on the element shank 9.

(11) Each of the axial ribs 33 of the disk element 27 is guided so as to be axially movable but rotationally fixed in an axial groove 37 (FIG. 3) located in the groove bottom 23 of the retaining groove 15. The respective axial groove 37 is designed in this case as a discontinuity in the elastomer material of the elastomer body 25. In addition, the axial groove 37 located in the groove bottom 29 of the retaining groove 15 has an axial stop 39 (FIG. 3) on the head side, which limits an axial movement of the disk element 27 toward the head section 7 in a final assembly process (described later), thereby limiting a pushing motion of the fastening element 1 in a mounting hole 41 of the panel 5 during the final assembly process.

(12) As is further evident from FIG. 4, the disk element 27 is guided so as to be axially movable on the element shank 9 of the fastening element 1 by means of a retaining device 43. According to FIG. 3, the retaining device 43 has an axial groove 45 on the outer perimeter of the element shank 9 as well as a preliminary latching rib 47 that is formed on the inner perimeter of the disk element 27 and projects into the axial groove 45.

(13) A preassembly process in which the fastening element 1 is preassembled on the retaining foot 17 of the bolt-on part 3 is described below on the basis of the attached FIGS. 6 to 8. Accordingly, as shown in FIGS. 6 and 7, the element shank 9 of the fastening element 1 is passed through a C-shaped mounting lug 49 of the retaining foot 17 of the bolt-on part 3 while the disk element 27 is still detached. After that, in accordance with FIG. 8, the disk element 27 is pushed onto the element shank 9 of the fastening element 1 until the preliminary latching rib 47 comes into loose latching engagement with the axial groove 45 located on the outer perimeter of the element shank 9, by which means the retaining device 43 is made ready. The preassembly process thus takes place without creating a stress.

(14) Subsequently, a final assembly process is carried out in accordance with FIGS. 9 to 11. The final assembly process is accomplished by means of a push/rotate actuation of the twist grip 51 formed on the head section 7. First, the element shank 9 of the fastening element 1 is passed through the mounting hole 41 of the panel 5 in a pushing direction, and then the fastening element 1 is rotated into the final assembly position in which the mounting bosses 11, 12 engage beneath an edge region of the opening of the mounting hole 41 of the panel 5. In the final assembly position, the head section 7 presses the two-piece elastomer profile part 13 against the panel 5, creating an elastic preloading, so that the retaining foot 17 of the bolt-on part is elastically preloaded in the axial direction. Moreover, the edge region of the opening of the mounting hole 41 of the panel 5 is clamped between the disk element 27 of the fastening element 1 and an upper side 53 of the mounting bosses 11, 12 with a predefined clamping force in the final assembly position. The component geometry of the bosses corresponds to the component geometry of the bosses disclosed in DE 10 2013 011 878 A1.

(15) Furthermore, in the final assembly position, the axial ribs 33 of the disk element 27 are guided into pressure contact with the axial stop 39 of the fastening element 1, using up the axial clearance of motion a. Consequently, the disk element 27 is supported by its axial ribs 33 on the axial stop 39 of the fastening element 1, by which means the disk element 27 presses the edge region of the opening of the panel 5 against the upper side 53 of the mounting bosses 11, 12 with a predefined clamping force.

(16) The fastening element 1 according to the invention can be provided for panels 5 of different panel thickness. For this purpose, different disk elements 27 can be provided whose axial rib height h is matched to the panel thickness in question. The following applies here: The greater the panel thickness of the panel 5 is, the smaller the axial rib height h is. Conversely: The smaller the panel thickness of the panel 5 is, the greater the axial rib height h is, in order to achieve the predefined clamping force by supporting the disk element axial ribs 33 on the axial stop 39 of the fastening element 1.

(17) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.