TECHNICAL FIELD

[0001]The invention relates to a fastening device for fastening attachment parts to structural parts, wherein the fastening device is provided for engagement through at least two axially spaced-apart pairs of through-openings.

BACKGROUND

[0002] It is known practice to provide fastening devices by which in particular plastic parts are arranged on motor vehicles. In particular, it is known practice to arrange aerodynamically acting coverings with fastening devices on metal parts of a vehicle, in particular of the body and/or of the chassis.

[0003] US 8,591,160 discloses a fastening device in which a spring-loaded pin with latching arms can be plugged through an opening wherein the spring then secures the latching.

[0004] DE 102017 125 722 A1 discloses a fastening device which, for fastening an object to a vehicle, has engage-behind means which are locked with a quarter-turn in an opening, wherein the locking is secured by spring arms.

[0005] DE 102005 032699 B4 also discloses a fastening device which operates with rotatable undercuts.

[0006] DE 102017 128 842 A1 discloses a fastening device in which a screw nut arranged in a cage is present which is axially movable in the cage by means of a screw and moreover can be rotated radially through 45° or 90°, wherein projections protruding radially on the nut can be rotated from a non-blocking plug-in position to a blocking and engaging-behind position and then tightened, and the fastening can thus be braced.

[0007] It is frequently the case in devices according to the prior art that these fastening elements either on the one hand cannot reliably avoid rattling or only one pair of openings is engaged through. On the other hand, demounting without destruction is not always possible.

[0008] Particularly the avoidance of noise, in particular rattling noise, is becoming ever more important with regard to electromobility applications and the quiet drives associated therewith.

[0009] Moreover, it is intended to be possible for aerodynamic coverings to be able to be removed, in particular in a repair situation or maintenance situation.

SUMMARY

[0010] It is therefore the object of the invention to provide an improved fastening device whereby in particular a noise-optimized, releasable and secure connection is possible.

[0011] The object is achieved by means of a fastening device having the features of claim 1. Preferred embodiments and advantageous developments of the invention are specified in the dependent claims.

[0012] According to the invention, a releasable fastening device is provided which fastens a first structural part to a second structural part in a rattle-free and releasable manner.

[0013] According to the invention, there is preferably provision that the fastening device can be brought into a locking/blocking position by means of a rotation after mounting and can also again be brought out of this position, possibly against a resistance, into an unlocked/unblocked position.

[0014] Moreover, there is provision according to the invention that the fastening device bears and fastens/blocks under tension, with the result that rattling or other noises is/are prevented on the one hand and unintentional release is prevented on the other hand.

[0015] Moreover, there is provision in the invention that the fastening device is of elongate, pin-like configuration and connects the structural part at two axially mutually aligned points on a device of a vehicle by means of engagement through corresponding aligned bores. [0016] The tension according to the invention can be produced for example by virtue of the fact that latching elements which engage behind a push-through opening for the fastening device are pressed with spring compression onto the material that surrounds the opening.

[0017] Moreover, it is possible for the elements which engage behind the push-through opening to be placed under tension by means of a screw.

[0018] Furthermore, it is possible to configure the engaging-behind in such a way that the engaging-behind elements themselves as a result of their shaping form a tensile stress which is elastically maintained by the material of the fastening device.

[0019] The invention relates in particular to a fastening device for fastening attachment parts to structural parts, wherein the fastening device is provided for engagement through at least two axially spaced-apart pairs of through-openings (or also sometimes referred to below as push-through openings) and is of elongate, pin-like configuration with a shaft, wherein the fastening device has at least one means for bearing axially on an attachment part and at least one means for engagement behind an opening (preferably one of the through-openings) on a structural part, wherein the means interact in order to secure the attachment part to the structural part and the fastening device moreover has a means for the centered securing of the further corresponding openings.

[0020] There is provision that the means for engagement behind a mounting opening are designed to be pivotable by rotation from a mounted position to a locking position. Here, a pivoting angle of 90° can be provided. Depending on the configuration, other pivoting angles, such as for example 45°, are also possible.

[0021] The means for centered securing of the further corresponding openings or of the second pair of through-openings is preferably a shaft region which, starting from the means for axial bearing, is situated beyond the means for engagement behind. This shaft region preferably has an outside diameter which is only slightly less than the inside diameter of the second pair of through-openings, with the result that the pair is coaxially centered and secured when this shaft region engages through the through-openings. By contrast with the bracing fastening devices mentioned at the outset, the fastening device according to the invention thus preferably has an additional, long shaft region between the distal end of the shaft and the means for engagement behind that is intended to be plugged into a second pair of through-openings.

[0022] In one embodiment, the means for engagement behind an opening are latching elements, which are radially movable out of and into a shaft, or a sliding block, which can be pivoted by way of a screw and tightened, or locking projections. Here, a pivoting angle of 45° can be provided. Depending on the configuration, other pivoting angles, such as for example 90°, are also possible.

[0023] An elastic compressive stress is preferably formed between the means for bearing axially on an attachment part and the at least one means for engagement behind an opening on a structural part, wherein the compressive stress is formed by a screw connection, a compression spring or a tension spring or elastic properties of the material forming the fastening device.

[0024] The compressive stress on the latching elements is preferably pressed, by spring compression, onto the material that surrounds the opening.

[0025] In one embodiment, the elements which engage behind a push-through opening are placed under tension or compression against the material by means of a screw.

[0026] In a further embodiment, the engaging-behind elements of the fastening device have ramp-like elements which point toward an opening and which increase the tension on the fastening element during locking.

[0027] In one embodiment, the fastening device is formed with an elongate, cylindrical shaft, wherein the elongate, cylindrical shaft has, at a first free end, a plate-like widening as a means for bearing axially on an attachment part, and it has a tip at an axial end opposite the free end in order to facilitate the pushing-through and locating of push-through openings, wherein two elongate slits are formed in the shaft between the free ends and are preferably designed to be radially opposite, wherein latching elements are mounted in the slits, engage through the slits and protrude outward with a preferably triangular region, wherein the latching projections are operatively connected to an actuation region which protrudes beyond a free end, wherein the actuation region is designed to be axially displaceable together with the latching projections in the shaft, wherein a compression spring, against which the element is preferably supported with a free end, is mounted in the shaft.

[0028] In a further embodiment, the fastening device is formed with a shaft, wherein the shaft has a region of square or rectangular cross section with flat side walls, wherein a circular disk-shaped widening for bearing axially on the attachment part is present at the axial end, wherein axial grooves are present in first planes and in particular extend axially and, in the region of one end of their extent, open into bearing grooves which are present in walls arranged orthogonally to the walls, wherein the axial grooves or slits and bearing grooves open from outside to inside in a bore for receiving a screw and a sliding block, wherein the sliding block has a cylindrical central body through which a threaded bore extends, and the engagement elements are formed on the central cylindrical body, wherein the engagement elements are formed in such a way that, when the sliding block is arranged in a groove, the engagement elements end flush with the corresponding wall, and, during rotation through preferably 45°, the engagement elements protrude from the slits.

[0029] In a further embodiment, the fastening device is formed with a shaft, wherein the shaft has a first end, formed with a drive, and an axial end lying opposite the first end, wherein radially protruding engagement-behind means are integrally formed on the shaft, lying diametrically opposite each other and protruding beyond a wall of the shaft, wherein the means are preferably box-shaped or cuboidal in form.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention will be explained by way of example with reference to a drawing, in which:

[0031] Figure 1 shows a chassis part as an exemplary part of a motor vehicle that is to be clad; [0032] Figure 2 shows an aerodynamic cladding part to be mounted on the chassis part;

[0033] Figure 3 shows a first embodiment of a fastening device according to the invention;

[0034] Figure 4 shows the fastening device according to the invention as per figure 3 on the cladding part;

[0035] Figure 5 shows a cross section, showing the fastening element according to the invention in a locked position, arranging the attachment part on the chassis part;

[0036] Figure 6 shows the arrangement as per figure 5 in a nonsectioned side view;

[0037] Figure 7 shows the arrangement as per figure 6 in a perspective view;

[0038] Figure 8 shows a further embodiment of the fastening device according to the invention;

[0039] Figure 9 shows the device as per figure 8 in a perspective view;

[0040] Figure 10 shows a screw for the fastening device as per figure 8;

[0041] Figure 11 shows a partial detail of the device as per figure 8, showing the interaction of sliding block and screw;

[0042] Figure 12 shows the device as per figure 10 in a locking position of the sliding block;

[0043] Figure 13 shows the sliding block for use in the device as per figure 8;

[0044]

[0045] Figure 14 shows the arrangement as per figure 8 in a partially sectioned view in a locked state on a chassis part;

[0046] Figure 15 shows the arrangement as per figure 14 in a side view; [0047] Figure 16 shows a cross-sectional enlargement showing the sliding block in a locked position;

[0048] Figure 17 shows a further embodiment of the device according to the invention;

[0049] Figure 18 shows the arrangement as per figure 17 in a partially sectioned view in a locked state on a chassis part;

[0050] Figure 19 shows the arrangement as per figure 17 in a perspective view in a locked position;

[0051] Figure 20 shows the arrangement as per figure 19 in an unlocked position;

[0052] Figure 21 shows a detail of the fastening device as per figure 17;

[0053] Figure 22 shows a detail of the fastening device as per figure 17;

[0054] Figure 23 shows a cladding part of the arrangement as per figure 17 in a perspective external view.

DETAILED DESCRIPTION

[0055] A chassis part 1 to be clad is shown in figure 1. This is for example a link for receiving a wheel arrangement, wherein the link 1 has two side walls 2, 3, wherein push- through openings 4, 5 are present in the side walls 2, 3 in order to push through fastening devices.

[0056] An aerodynamic cladding 6 (figure 2) to be arranged on the chassis part 1 has corresponding push-through openings 7, 8 which are arranged on the inner side of a side wall 9 of the cladding 6, with it being the case, however, that the push-through openings run through receiving posts 10, 11 which extend away from a side wall 9 on the inner side. Axially aligned with the push-through openings 7, 8 are centering opening means 12, 13 which are formed on centering lugs 14, 15, wherein the centering lugs 15, 14 extend from a bottom wall 16 parallel to the side wall 9. [0057] In a first embodiment of a fastening device 20, the fastening device 20 is formed with an elongate, cylindrical shaft 21, wherein the elongate, cylindrical shaft 21 has a plate like widening 23 at a first free end 22 and, at its axial end 24 diametrically opposite to this free end 22, has a tip 25 in order to facilitate the pushing through and locating of push- through openings 7, 8, 12, 13.

[0058] At least two elongate slits 26 are formed in the shaft 21 between the free ends 22, 25. The slits can preferably be formed radially oppositely.

[0059] In the slits 26 there are mounted latching elements 27 which engage through the slits 26 and protrude outward with a barb-shaped region.

[0060] The latching projections 27 are functionally connected to an actuation element 28. The actuation element 28 preferably protrudes beyond the free end 22. The actuation element 28 is for example of elongate cylindrical form and has an outside diameter which corresponds to or is somewhat smaller than the inside diameter of the shaft 21.

[0061] At its free end the portion 28 has a drive 29, for example for an internal hexagon wrench, internal Torx wrench or the like.

[0062] The region 28 engages through the shaft 21 as already stated, wherein the latching elements 27 are radially pivotable on the element 28 and are arranged on the or in the portion 28 so as to be possibly mutually supported via a spring (not shown). In addition, a compression spring 30 is mounted in the shaft 21, against which spring the element 28 is preferably supported by a free end 31 or is operatively connected in some other way. In embodiment alternatives, a tension spring can be provided instead of the compression spring 30, wherein the operative connection with the element 28 is then configured in a suitable manner.

[0063] To fasten a cladding 6 to a structural part 2, the cladding part is first of all arranged on the structural element 2 in a positionally correct manner such that the push-through openings 7, 8, 12, 13 on the one hand and the push-through openings 4, 5 on the other are aligned with one another. [0064] The fastening device 20 is then pushed through the holes 4, 7, 12 and 5 with the shaft 21 and in particular with the tip 25 leading until the plate-like widening 23 bears on a corresponding step 32 of the cladding part. The actuation region 28 is then pressed against the compression spring 30 until the latching elements 27 can engage behind the wall 2 and snap out. In this state (figure 5), the fastening device 20 is arranged locked both on the cladding element 6 and on the vehicle part 1.

[0065] In order to release the locking, the actuation element 28 is pressed further against the spring 30 into the shaft 21 in particular by means of a suitable tool corresponding with the drive, wherein a front edge 34 of the latching elements interacts with an axial edge 33 delimiting the slits, and the edges 33 slide along the edges 34 and thus press the latching elements 27 back again into the actuation element 28. After the actuation element 28 has been pressed into the shaft 21 as far as possible, a rotation through 90° is performed with the aid of the drive and a suitable tool, with the result that the latching elements 27 bear on the inner side of a shaft wall. In this unlocked state, the device 20 can be pulled out of the push-through holes again.

[0066] In a further advantageous embodiment of the fastening device, the fastening device 40 is likewise formed with a shaft 41, it being the case, however, that the shaft 41 is designed to be square or rectangular in cross section with flat side walls, wherein a circular disk-shaped widening 44 is formed at an axial end 43 and a tip 46 is formed at the opposite end 45. In the region of the end 45, the cross section of the fastening device can for example also be designed to be tapered in rounded fashion.

[0067] The shaft 41 has in its angular region 42 a first pair of opposite side walls 47 and, perpendicularly thereto, a second pair of parallel running flat side walls 48.

[0068] In the flat side walls 48 there are axial grooves 49 or slits 49 which extend in particular from the circular disk-shaped widening 44 in the direction toward the other end 45 and end still in the region 42 and open there into bearing grooves 50 which are incorporated in the side walls 47. The bearing grooves 50 extend from the axial grooves 49 approximately over a half of the side wall 47. [0069] The slits 49 and grooves 50 open radially inward into a bore 51 for receiving a screw and a sliding block.

[0070] The screw 52 has a drive end 53 with a screw drive 54 and a circular disk-shaped widening 55 which can also be formed as a separate washer 55.

[0071] With the drive-side end 53 the screw 52 widens in particular by way of a step, as is known in the case of such screws, in particular with internal drive.

[0072] At an opposite end 56, the screw has a thread 57. On the thread there is screwed a sliding block 58, wherein the sliding block 58 has a cylindrical central body 59 through which a threaded bore 60 extends, wherein the thread of the threaded bore 60 is tailored to the thread of the screw 52 such that rotation of the screw leads to the sliding block being pulled onto the thread or being unscrewed therefrom.

[0073] On the central cylindrical body 59 there are formed radially diametrically opposite engagement elements 61 which first of all extend radially away from the basic body 59 with an axially elongate square cross section and then transition into converging bevels 62 which meet a common radial edge 63. The radial edge 63 is formed in the manner of a ridge and extends axially corresponding to the longitudinal extent of the cylindrical basic body 59.

[0074] The distance between the ridge 63 and the central basic body 59 on the one hand and the positioning of the bevels 62 are dimensioned here in such a way that, with an arrangement of the sliding block 58 on the screw 52 in a basic position (figure 11), a bevel 62 is designed to terminate level with the side walls 47, 48. In this position, the fastening device 40 can accordingly be pushed through corresponding push-through openings corresponding to the cross section of the fastening device 40.

[0075] If the screw 52 is then screwed in, the sliding block 58 also rotates in the screwing direction, which leads to the sliding block passing into the slits 49 and being able to be correspondingly pulled along a bevel 50a out of the groove 50 and toward a screw drive- side end. The sliding block is preferably rotated through 45°. [0076] By virtue of the shaping of the sliding block (figure 12), the ridge 63 then protrudes, with parts of the corresponding end faces of the projections 61, beyond the walls 48. It is accordingly possible in this position for locking and fastening of an attachment part 6 to a vehicle part 1 to occur, wherein, in an analogous manner to the first embodiment, the fastening device 40 engages through the corresponding through-openings and, as a result of the screw being screwed in, the projections 61 are moved by the screw counter to the extent from the screw drive to the tip in such a way that the projections 61 bear on the wall 2 on the inner side and thus ensure locked fastening.

[0077] To release the connection, the screw is unscrewed in the counterclockwise direction in a manner corresponding to the corresponding thread pitch. In this way, particularly if the screw is here fixed axially in the shaft or an axial movement is not allowed during screwing, the sliding block is displaced along the grooves or slits 49 in the shaft tip direction again and rotates corresponding to the screwing direction of the screw, if this is possible, again into the regions 50 in which it has its walls 61 ending flush again with the corresponding walls of the shaft, and the fastening device can thus be removed.

[0078] In a further advantageous embodiment of the fastening device, the fastening device 70 is formed with a shaft 71, wherein the shaft 71 has a first end 72 formed with a drive 73 and has a diametrically or axially opposite plug-in-side end 74. As part of the means for engagement behind 75, the shaft has cross struts formed thereon which on both sides protrude diametrically oppositely beyond a wall 76 of the shaft 71.

[0079] Here, the cross struts are substantially box-shaped or cuboidal in form with a front edge or front surface extending transversely to the longitudinal extent of the shaft 71 and with a rear locking surface 76 protruding laterally in each case beyond the shaft. Here, the locking surfaces 76 each extend obliquely in the same direction with respect to the plug-in direction and end with a plateau 77. At a distance from the cross struts there are provided rotation locks 78 which protrude in the same direction and which prevent a situation in which the fastener can be already rotated before it is situated in the actual end position. [0080] As also in the case of the other embodiments, a circular disk-shaped widening 79 is present adjacent to an end 72 or the drive 73 arranged thereon.

[0081] Star-shaped guide or spacer strips 80 extend diametrically outward from the widening 79 along the shaft.

[0082] In the mounted state (figure 18), this embodiment of the fastening device 70 also engages with its shaft 71 through the corresponding mounting openings, wherein, in the mounted state, the cross struts engage behind the wall 2 by rotating the fastening device. The abutment elements 78 act on or bear on the opposite surface of the wall 2, with the result that a defined spacing corresponding to the thickness of the wall 2 is defined between the rotation locks 78 and the cross struts.

[0083] The strips 80 are arranged in a cylindrical additional widened bore 81 of the post 7.

[0084] The circular disk-shaped widening 79 bears on a corresponding step 82 of the post 7.

[0085] In this embodiment or for this embodiment, the push-through opening in the wall 2 takes the form of a slit or is formed in the manner of a keyhole, wherein the slit 83 in the wall 2 here corresponds in its dimensions to the cross strut, with the result that the device 70 can be plugged with the cross struts through the slit 83.

[0086] If the device 70 is then rotated through 90° (figure 19), the bevels 76 slide along the edges bounding the slit 83 and pull the device 70 against the stop of the step 82. This occurs until such time as the plateaus 77 bear on the inner side of the wall 2 and further rotation is thus possible.

[0087] The rotation locks 78 here bear on the wall 2 on the other side, wherein a cutout is preferably present in the post 7 adjacent to the bore situated therein and facing the wall 2 in such a way that the rotation of the device 70 is ended or is blocked when the cross struts are situated transversely with respect to the slit 83. [0088] On the underside of the widening 79 there are preferably provided rounded latching projections 84 (figure 22) which extend in the direction toward the plug-in direction or toward the shaft 71. Latching grooves 86 corresponding thereto and extending in a manner of a circular segment are preferably present in a receiving or bearing opening 85 (figure 23) of the post 7 on the step 82, wherein the latching grooves 86 have a plug-in-side end 87, in which the projections 84 initially bear when plugging through the device 70, and a latching end 88 into which the elements 84 snap after the end of the locking rotation. This locks the device 70 against inadvertent rotation.

[0089] In all of the graphically illustrated embodiments, the means for centered securing of the further corresponding openings or of the second pair of through-openings is a shaft region (for example 74) which, starting from the means 23, 44, 79 for axial bearing, is situated beyond the means for engagement behind 27, 58, 75.

[0090] It is advantageous in the invention that devices are provided by means of which the fastening of attachment parts and in particular aerodynamic attachment parts to vehicle parts succeeds in a reliable, permanent, rattle-free and rereleasable manner.