The invention relates to a device for securing a structural element provided with a hole to a panel-like component, said panel-like component being fitted with a stay-bolt onto which can be pressed on the side opposite the component a hollow cylindrical part with a flange, said hollow cylindrical part being able to be received by the hole and having a latching portion, the flange having a diameter greater than the diameter of the hole.
Such a device containing the aforementioned design is published in DE 196 30 249 C2. The known device is a device for securing an insulation panel to a component. The device has a hollow cylindrical portion which can be pressed axially onto a threaded stay-bolt and which has a flange on one side and radially extendable arms on its other side, with the result that an insulation panel which is to be secured in position is surrounded on its one side by the flange and on its other side by the extendable arms. The hollow cylindrical portion is fixed to the stay-bolt by means of a latching portion which engages the thread of the stay-bolt, thus establishing the connection between the hollow cylindrical portion and, through the stay-bolt, with the panel-like component. In this device, the fixing of the insulation panel in the direction away from the panel-like component is effected exclusively by the flange, the stability of which is therefore of particular importance in this connection. Furthermore, the extendable arms are of relatively complex construction, this making the device especially elaborate as a whole.
The object of the invention is to provide a device for securing a structural element provided with a hole to a panel-like component, said device being of simpler design and being more secure, particularly with regard to the holding forces, the completed, secure attachment of the respective structural element being clearly visible.
The object of the invention is achieved in that a metal part, forming the latching portion and having a plurality of latching lugs, is inserted into the hollow cylindrical part, wherein the hollow cylindrical part has a spring portion which yields to axial pressure and the structural element is provided on its side facing the component with an inwardly directed collar on which rests the hollow cylindrical part with its end opposite the flange when the hollow cylindrical part is in the secured position with the spring portion pressed in.
The design of the latching portion in the form of a metal part provided with a plurality of latching lugs makes it possible for the device to be used in connection with stay-bolts which are provided with threads or just with grooves or, alternatively, with stay-bolts which have a smooth cylindrical surface, because metal parts provided with latching lugs have proved in this connection to be especially resistant to pull-off forces. This is also true in the case of stay-bolts which are provided with thick-layered corrosion-protection coatings which are easily penetrated by the metal latching lugs. The inwardly directed collar on the structural element and the end, facing said collar, of the hollow cylindrical part, which, through the metal part with its latching lugs, is connected especially securely to the stay-bolt, result in a fixing of the structural element which, through the adjoining contact of collar and the respective side of the structural element, guarantees a connection with high pull-off forces, without the flange on the hollow cylindrical part being burdened with a special securing function. However, thanks to its spring portion, which yields to axial pressure, the hollow cylindrical part provides the observer with a visual signal as to whether the hollow cylindrical part has reached its end position, i.e. whether, on the one hand, the stay-bolt is securely seated on the component or whether, on the other hand, the structural element is securely attached to the stay-bolt, because, namely, with hollow cylindrical part and structural element in the secured position, the flange is tightly pressed against the hollow cylindrical part, thus indicating the secure attachment of the structural element to the likewise securely seated stay-bolt.
The metal part may be fixedly embedded in the hollow cylindrical part, this being of advantage particularly if the hollow cylindrical part is of injection-moulded plastic, the metal part being embedded during injection-moulding.
It is also possible for the hollow cylindrical part to be provided with a radial slit into which the metal part is inserted.
The flange on the hollow cylindrical part with its spring portion which resiliently yields to axial pressure ensures that, if using a welding stud as the stay-bolt, the spring force of the spring portion will pull back the welding stud from the panel-like component if the welding stud is inadequately secured, with the result that the flange is able to return to its original curved position, thereby indicating that the secure attachment of the welding stud to the panel-like component has not taken place, i.e. the welded connection is inadequate, this being indicated by the coming-away of the inadequately welded-on welding stud and therefore the yielding of the spring portion on the flange.
In order, during the securing of the structural element, to compensate for a possibly existing tilted position of the welding stud as a result of a manufacturing defect, the slit in the hollow cylindrical part is advantageously of such design that the slit is of such an oversize in relation to the thickness of the metal part that the metal part is able to assume a tilted position which compensates for an oblique position of the welding stud. The oversize of the slit makes it possible for the metal part, if necessary, to assume an oblique position in the region of the over-size of the slit.
Advantageously, the metal part has an anti-rotation means in the slit which accepts the metal part, this ensuring that, particularly in the case of vibrations during the use of the device, the metal part is unable to rotate in relation to the stay-bolt, which might result in the course of time in a certain loosening of the metal part in relation to the stay-bolt.
The latching lugs are advantageously of such design that they are of different lengths. This ensures that the latching lugs clawingly engage the stay-bolt axially in different positions, which is shown by experience to improve the security of the connection between the metal part and the stay-bolt. This is especially true if the stay-bolt is a threaded bolt.
The device also makes it possible to compensate for tolerances to a considerable extent, this allowing the structural element to be attached to the panel-like component with considerable tolerance in the plane of the panel-like component. This is advantageously accomplished in that both the hollow cylindrical part and also the stay-bolt are surrounded with clearance by the hole in the structural element. Thus, the hollow cylindrical part accepting the stay-bolt is situated opposite a considerable clearance in the hole of the structural element, i.e. the structural element is able correspondingly to move in relation to the hollow cylindrical part in the plane of the panel-like component.
In order to seal the region of attachment of the stay-bolt to the panel-like component, the structural element is advantageously provided on its side facing the component with a sealing lip. When the hollow cylindrical part is placed in position and thus the structural element is pressed against the panel-like component, the sealing lip is pressed against the structural element, this resulting in the desired sealing effect.
For the attachment of the device to the stay-bolt, it may be advantageous for the hollow cylindrical part to be provided with a receiving means for a screwing-in tool. This is especially true if the stay-bolt is threaded. However, also if using a stay-bolt with a smooth cylindrical surface, it is especially easy to attach the hollow cylindrical part with the metal part consisting of a plurality of latching lugs when the metal part is screwed onto the stay-bolt. In the case of the use of the device according to the invention, particularly in automobile construction, it is advantageous for both the structural element and also the hollow cylindrical part to be provided with acoustic insulation.
As already mentioned, the stay-bolt may be a bolt with a smooth, cylindrical surface or a bolt with circumferential grooves, wherein the circumferential grooves may be formed by closed circles or, alternatively, by a thread.
For the purpose of the pre-assembly of hollow cylindrical part and structural element, the hollow cylindrical part may be secured to the structural element by a latching means, this guaranteeing the captive securing of the hollow cylindrical part in the structural element.
Advantageously, the spring portion may be in the form of a resiliently yielding bulge of the flange. The pressed-in bulge indicates to the observer that the hollow cylindrical part is in tight contact with the structural element.
Another design of the spring portion consists in that the hollow cylindrical part is provided on its side opposite the flange with one or more spring elements which force the hollow cylindrical part away from the structural element. If the spring elements remain elongated, the distance between the flange and the structural element indicates to the observer that the hollow cylindrical part is not in secure contact with the structural element. The flange may be of either curved or flat design.
Illustrative embodiments of the invention are presented in the drawings, in which:
a, b and c show an embodiment with metal part injection-moulded into the hollow cylindrical part and with a threaded stay-bolt,
a and b show the device according to
a, b, c show an embodiment with flat flange and spring elements on the hollow cylindrical part on the side thereof opposite the flange,
a presents the device according to the invention, consisting of hollow cylindrical part 1, structural element 2 and stay-bolt 3, with the hollow cylindrical part 1 in its position prior to being pressed onto the stay-bolt 3. For accepting the hollow cylindrical part 1, the structural element 2 has the hole 4, which is oversized to allow the hollow cylindrical part 1 to be accepted. The stay-bolt 3 is in this case a welding stud which is connected via the weld 5 to the panel-like component 6. The panel-like component 6 may be any structural element of, for example, a motor vehicle.
The hollow cylindrical part 1 has on its side opposite the component 6 the flange 7, which is curved and which, because of its material, resiliently yields when pressure is applied to the edge 8 of the flange 7; this will be discussed in fuller detail below. Plastic is preferably used as the material for the hollow cylindrical part 1. The metal part 10 is injection-moulded into the hollow cylindrical part 1 and is therefore fixedly embedded in the plastic hollow cylindrical part 1. The latching lugs 11 project obliquely out of the metal part towards the flange 7. The hollow cylindrical part 1 is also provided in the region of its flange 7 with the receiving means 12 for a screwdriver, said receiving means 12 here being in the form of a slit. It is, of course, also possible for the respective location to be provided with a recess for a different screwing-in tool, e.g. a hexagon key.
For receiving the stay-bolt 3 in the hollow cylindrical part 1, the hollow cylindrical part 1 is provided with the blind hole 27, into which the stay-bolt projects when the hollow cylindrical part 1 has been fully pressed onto the stay-bolt (see
In order to connect the structural element 2 to the component 6, the hollow cylindrical part 1 is pressed onto the stay-bolt 3,
c shows the same arrangement in its final position, the hollow cylindrical part 1 having been pressed fully onto the stay-bolt 3. The hollow cylindrical part 1 pushes with its end 14 opposite the flange 7 onto the inwardly projecting collar 15 of the structural element 2, this completing the pressing-in movement of the hollow cylindrical part 1. In this position, the collar 15 and therefore the structural element 2 are firmly pressed against the component 6, the latching lugs 11 preventing the hollow cylindrical part 1 and the structural element 2 from sliding back. Consequently, the structural element 2 is securely attached to the component 6 with the aid of the hollow cylindrical part 1 and the stay-bolt 3.
With the hollow cylindrical part 1 in the position shown in
Owing to the material-induced spring tension of the flange 7 in the position shown in
A different manner of introducing the metal part 10 into the hollow cylindrical part 1 consists in inserting the metal part 10 into a radial slit 9 in the hollow cylindrical part 1. Such a design is presented in
When welding studs are being welded on, experience shows that it is repeatedly the case that said welding studs are welded on at a slightly oblique angle with respect to their subsurface (see
a presents a further variation on the device shown in
b presents the arrangement from
The embodiment of the device according to the invention as presented in
a shows the device in a position in which the hollow cylindrical part 1 is positioned prior to being pressed onto the stay-bolt 3. As for the rest, reference is made in this regard to the explanatory remarks given with respect to
In
c shows the device in a position in which the hollow cylindrical part 1 is fully pressed in, the spring elements 31 and 32 being tightly in contact with the respective edge of the hollow cylindrical part 1, the flange 30 at the same time being in contact with the surface 13 of the structural element and therefore indicating that the hollow cylindrical part 1 has been fully pressed into the structural element 2.
Number | Date | Country | Kind |
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103 57 450.6 | Dec 2003 | DE | national |
103 27 579.7 | Jun 2003 | DE | national |