DE102008031785A1 - Fastening system i.e. mass pin, for fastening e.g. cable lug to body part, has radial enlargement and recess penetrating via isolating layer of threaded bolt in region of bolt base and produce electrical contact between bolt and component - Google Patents

Abstract

The system (10) has a radial enlargement and a radial recess cooperatively arranged at a bolt shank (12) in a region of a bolt base (13) having a nut (14), and/or provided at an electrically conducting component e.g. cable lug (50). The radial enlargement and the recess penetrate through an electrically isolating layer of a threaded bolt (11) in the region of the bolt base and produce an electrical contact between the threaded bolt and the electrically conducting component. An inner diameter of the radial recess at a surface region is smaller than an outer diameter of the radial enlargement.

Description

The The present invention relates to a fastening system for attachment an electrically conductive component, with one with an electrical provided insulating layer, a Bolzenfuß and a bolt shank having, the component receiving threaded bolt.

The The present invention addresses the problem of by means of a threaded bolt an electrically conductive connection between an electrically conductive component and another workpiece, at which the threaded bolt is arranged to be electrically conductive, manufacture. This problem occurs especially in the automotive industry on, where it is the workpieces to body parts which is provided with the threaded bolt and then painted be, where after painting the electrically conductive connection For example, must be made to a cable lug.

The German utility model G 93 12 678 U1 discloses a method that is common in the automotive industry. Bolts bolted with bolts are supplied, which are welded to the body parts and painted together with them. Then the cap nut is unscrewed, the respective cable lug attached and screwed the cap nut again, the cable lug is attached. The cap nut prevents during the painting that the bolt shaft is covered with an electrically insulating paint layer, which would prevent the electrically conductive contact between the body part and cable lug. However, such a method is time-consuming and expensive and therefore expensive.

Further are known as "paint scratch nuts" Nuts cause when screwed onto a painted stud shaft the lacquer layer scraped off again from the bolt shaft and on this Way the electrical contact is made. However, it is difficult to Screw the nut onto the bolt shank because the paint coating penetrates into the bolt thread and thus hinder the screwing. In particular, the mobility of the screw connection is unsatisfactory and As a result, the electrical contact is not guaranteed to be safe.

The "paint scratch nut" acts like a tap in this process, what the other problem poses that the bolt thread over its entire length, So from the tip to the Bolzenfuß, scraped off. Thus, the corrosion protection goes to the exposed tip and lost the exposed threads of the bolt shaft, so it must be covered with a cap or cap nut. This leads to a higher weight and rising Costs.

The Object of the present invention is therefore a generic Fortification system such that a reliable and permanent electrical contact with the lowest possible Effort can be achieved.

The Solution consists in a fastening system with the features of patent claim 1. According to the invention, in that the fastening system has means which are on the bolt shank in the area of the bolt foot cooperating with a nut are arranged and / or provided on the component, and that the or the means the threaded bolt electrically insulating layer exclusively penetrate in the area of the bolt foot and an electric Contact between the threaded bolt and the component cause.

Of the The inventive idea is therefore that on a Workpiece electrically conductively fastened bolt shank together is painted with the workpiece and that means are provided Make sure that the bolt shank only in the area of the bolt foot is scraped to the paint layer in this area again remove and the electrically conductive connection between workpiece and manufacture components reliably and permanently.

This inventive principle can basically about realizes two different, equally effective solutions become. The first solution is that a mother is provided with a in the area of the bolt foot arranged on the bolt shank means cooperates in this Area to remove the paint layer. The second solution is that the component itself has means the part of the fastening system according to the invention and remove the paint layer in the area of the bolt foot. A mother does not necessarily exist.

The inventive fastening system thus exists Made of components that require little effort and therefore cost can be manufactured and assembled. The complicated unscrewing and re-screwing a cap nut after the painting process deleted. The with the fastening system according to the invention manufacturable electrical connection is reliable and permanent. The paint layer on the top, after installation in the Usually exposed area of stud shaft remains undamaged, so that it acts as an insulating and corrosion protection layer and the Stud shank no longer as in the prior art with a cap or cap nut must be covered.

Advantageous developments emerge from the dependent claims.

Of the first approach of the present invention, in which a Nut is provided with one in the area of the bolt foot On the bolt shaft arranged means cooperates, for example be realized that the means arranged on the bolt shank as radial widening is formed, which with a radial recess cooperates in the mother whose inner diameter is at least a surface area is smaller than the outer diameter radial broadening. The bolt shank is thus in the range of the bolt foot widens. The nut is with a corresponding radial Recess provided which the radial broadening during assembly embraces. Due to the undersize is thereby the paint layer scraped off the widened area and the electrical contact area exposed. As neither at the widened area of the bolt shank yet in the recess of the nut is provided a thread, are both mother as well as bolts particularly easy and inexpensive to manufacture.

The radial recess in the nut can be defined by at least one vertical Groove be interrupted so that the vertical edges of the groove as Cocking elements against the radial broadening act and thus expose the electrical contact surface. Especially suitable are two or more, especially evenly around the circumference of the radial recess distributed grooves. With this Training can reduce in particular the scraping torque or the desired Preload can be reliably achieved.

The Radial broadening on the bolt shank can be manifold Be designed to achieve the effect described above, for example, out-of-round, knurled, polygonal or round. A Particularly easy to manufacture embodiment of the radial Broadening is training as a rotating alliance. In comparable Way can also achieve the radial recess in the nut to achieve the described effect is formed in different ways, for example, out of round, toothed or cylindrical.

In Particularly advantageous is the diameter of the internal thread the nut larger than the diameter of the external thread of the bolt shaft. This ensures particularly reliable, that regardless of the thickness of the paint layer in an individual case this at Screw the nut into the threaded area of the nut Bolt shank remains intact and a reliable Forms corrosion protection.

to Simplifying the assembly can make the component rotatable and captive be connected with the mother. The component may, for example, have an opening, on the inside at least two axially extending retaining tabs are formed, which in a circumferential undercut in the mother intervene. Conversely, the component but can Also have at least two holding elements, which one at the Mother provided, encircling or encircling in an at the Mother intended to engage circumferential recess. After all the component can also have a circumferential bead, which encompasses the encircling collar or in the circumferential recess intervenes.

Of the second approach of the present invention, wherein the Component itself has means that are part of inventive fastening system and are can remove the paint layer in the area of the bolt foot For example, be realized by that provided on the component Means as arranged on the inside of an opening, at least two claws are formed radially in the opening protrude, and that the open space between the free ends the claws are at least as large as the diameter of the bolt shaft in the area of the bolt foot. It follows that during assembly of the component, the claws in the area of the bolt foot Scrape along the thread of the bolt shank. Since the component before Assembled with its opening from the bolt shank is and essentially rests on the bolt foot remains the lacquer layer on the bolt shank undamaged in its upper area. The assembly can be done with any suitable tool, eg. Assembly wrench, wrench, etc. Since the claws are wedged with the thread after the assembly process are, it is not mandatory, an additional Provide nut for attachment of the component to the threaded bolt, there the component automatically held on the bolt reliable is. The use of a nut, for example. As an assembly tool is at the discretion of the user. Further, modifications are made in terms of the claw shape, the material combination of component, claws and bolt shank and the strength of the materials used in each case conceivable so that this embodiment of the invention Mounting system a particularly wide range of variation regarding their physical properties.

The free ends of the claws are preferably above the component in FIG Direction of the bolt shaft aligned. This will help you Fastening process particularly far down and pressed inside and thus particularly firmly pressed into the thread of the bolt shaft.

The shape of the claws can be chosen freely and is at the discretion of the person skilled in the art. For example. The claws in cross section in about one S-shape or Z-shape. But they can also be formed straight, which allows a particularly simple production.

In In another embodiment, the bolt shank a Have radial broadening, which is used to produce the electrical Contact between the threaded bolt and the component with the claws interacts. The radial widening can be with or without thread be educated. In an advantageous alternative training can be provided in the radial broadening recesses be to assist the wedging of the claws and so a particularly strong connection between the bolt shaft and to get the component, which is an additional fuse For example, by a mother dispensable. Again, for convenience the production of the radial broadening formed as a circumferential collar be.

at the embodiment of the second approach of the present Invention in which the component itself has means the part of the fastening system according to the invention and remove the paint layer in the area of the bolt foot, The component can also rotatable and captive with a nut be connected, if desired. Therefor the component may have at least two retaining elements, which embrace a provided on the mother, circumferential collar or engage in a provided on the mother, circumferential recess.

The Component may in particular a fork-shaped, Have the bolt shank encompassing contact surface, the easy to manufacture and particularly unproblematic with the bolt shank to connect.

The Component is preferred as a cable lug, in particular for use in the automotive industry.

One Embodiment of the present invention is in Below with reference to the accompanying drawings closer described. Here are the same components with the same reference numerals Mistake. Shown schematically, not to scale:

1 an embodiment of an inventive fastening system in the assembled state;

2 a first embodiment of the fastening system according to the invention in section;

3 a second embodiment of the fastening system according to the invention in section;

4 a third embodiment of the fastening system according to the invention in section;

5 a fourth embodiment of the fastening system according to the invention in section;

6 a fifth embodiment of the fastening system according to the invention in section;

7 an embodiment of a suitably designed for the fastening system according to the invention component in the form of a cable lug in plan view;

8th a further embodiment of a nut for the fastening system according to the invention.

1 shows an embodiment of a fastening system according to the invention 10 , which is also referred to as "ground pin" and here serves a cable lug 50 in electrical contact with a workpiece 40 to bring, for example, to a body part. The fastening system 10 has in the embodiment a threaded bolt 11 on, the one bolt shaft 12 and a bolt foot 13 having. The threaded bolt 11 is with his stud foot 13 electrically conductive with the workpiece 40 connected, for example. Welded. Bolt on the thread 11 is as another component of the fastening system 10 A mother 14 screwed. The mother 14 serves to the cable lug 50 to hold on the bolt foot.

For example. in automotive engineering, the threaded bolt 11 without the mother 14 on the body part 40 attached. Subsequently, the body together with the threaded bolt 11 painted. Then the cable lug 50 mounted and by screwing the nut 14 held. The electrical contact between the cable lug 50 and the body part 40 must therefore from the cable lug 50 about the mother 14 from the nut thread to the bolt thread and over the bolt foot 13 run into the body part. For this purpose has to be from bolt shaft 12 the paint layer are at least partially removed again. The fastening system according to the invention 10 is characterized by the fact that the end of the bolt shaft 12 is exposed, ie not covered with a cap or cap nut. In this exposed area, the paint layer is on the bolt shank 12 undamaged, although the mother 14 already screwed on, so that the lacquer layer as corrosion protection for the bolt shank 12 acts. How this result can be achieved, the 2 to 6 ,

2 shows a first solution principle for the construction of Befestigungssys invention tems 10 , In this solution principle, the threaded bolt act 11 and the mother 14 together so that on the bolt shank 12 the paint layer only in the area of the bolt foot 13 Will get removed. This is the bolt shank 12 in the area of the bolt foot 13 , ie in the embodiment above the bolt foot 13 , with a radial broadening 15 provided, which is formed in the embodiment as a circumferential collar. Other forms of radial broadening 15 are of course also conceivable, for example, a polygonal, non-round, knurled or multi-round shape. The mother 14 is with such a shaped radial recess 16 provided that the purpose described is achieved, for example. Cylindrical, out of round or serrated. The inner diameter of the radial recess 16 is smaller than the outer diameter of the radial broadening on at least one surface area 15 , The radial recess 16 works with the radial broadening 15 thus in such a way that their inner surface 17 with respect to the outer surface of the radial widening 15 How a scraper works, leaving only a selected area of the bolt shaft 12 namely, near the bolt foot 13 , the lacquer layer is at least partially removed again and over a contact surface 18 an electrically conductive contact between the bolt shank 12 and the mother 14 will be produced. For this purpose, a small undersize of the radial broadening is sufficient 15 , The paint layer on the remaining area of the bolt shaft 12 remains undamaged, especially in the area of the bolt thread, in particular at the exposed end of the bolt shaft 12 , In this context, the radial recess 16 with at least one, preferably two or more vertical grooves 25 be provided, whose vertical edges 26 as scraping edges against the surface of the radial broadening 15 Act. Furthermore, it is advantageous if the diameter of the internal thread of the nut 14 greater than the diameter of the external thread of the bolt shaft 12 , This allows the dimensions of the fastening system according to the invention 10 chosen independently of the thickness of the paint layer in each case and both the accessibility of the screw and the integrity of the protective lacquer layer in the upper region of the threaded bolt 12 be ensured particularly easy.

3 shows a fastening system 10 which is also the one above in 2 realized first solution principle realized. In this variant is to simplify the installation of the fastening system 10 the component 50 , In the embodiment of the cable lug, rotatable and captive on the mother 14 held. For this purpose are on the inside of the opening 51 of the cable lug 50 at least two axially extending retaining tabs 52 educated. Accordingly, the mother is 14 with a circumferential undercut 19 equipped, in which the retaining tabs 52 intervention.

4 shows a second solution principle for the construction of the fastening system according to the invention 10 , In this solution principle, the component acts 50 , In the embodiment of the cable lug, so with the threaded bolt 11 together, that at the bolt shaft 12 the paint layer only in the area of the bolt foot 13 Will get removed. This is the cable lug 50 , which in the assembled state in the area of the bolt foot 13 , ie in the embodiment above the bolt foot 13 , is held on the inside of its opening 51 with at least two arbitrarily shaped, in the embodiment in cross-section rectilinear, claws 21 provided, which protrude radially into the opening. The clear width between the free ends of the claws 21 is sized so that when assembling the cable lug 50 , ie when screwing the nut 14 , the claws 21 such with the bolt shank 12 interact only in the selected area of the bolt shaft 12 namely, near the bolt foot 13 , the lacquer layer is at least partially removed again and via contact surfaces 22 an electrically conductive contact between the bolt shank 12 and the component 50 will be produced. The paint layer on the remaining area of the bolt shaft 12 remains undamaged, especially in the area of the bolt thread, in particular at the exposed end of the bolt shaft 12 ,

In the in 4 illustrated embodiment, the claws 21 angled out of the plane of the opening 51 towards the mother 14 bent, leaving their free ends above the opening 51 of the cable lug 50 lie. In this embodiment, it is sufficient if the clear width between the free ends of the claws 21 is at least as large as the diameter of the bolt shaft 12 in the area of the bolt foot. During assembly, ie screwing the nut 14 , the claws become 21 in the direction of the bolt foot 13 depressed and wedged in the threads of the bolt thread. This allows the cable lug 50 so firmly on the bolt shank 12 be held and connected with him, that the mother 14 for secure attachment of the cable lug 50 is dispensable.

Instead, for mounting the cable lug 50 on the threaded bolt 11 also a tool 30 (in 4 dash-dotted lines shown), which on the bolt shank 12 is screwed, while the claws 21 as described reign in the threads of the bolt shaft 12 pressed and then unscrewed again. Another variant is that a sleeve-shaped, the bolt encompassing tool is used, with the claws 21 be depressed as described schabend in the threads of the bolt nomic 12 press.

5 shows a fastening system 10 which is also the one above in 4 realized second solution principle realized. In this variant, the bolt shaft 12 with a radial broadening 15 as they already are in terms of 2 has been described. The clear width of the claws 21 is dimensioned so that when mounting with the radial widening 15 cooperate such that the described contact surfaces 22 be formed. 5 shows a particularly preferred embodiment of the radial broadening 15 , the recesses 23 , For example, recesses, in the exemplary embodiment, a circumferential groove, in which the claws 21 can wedge during assembly. The recesses 23 So act similar to the threads of the bolt shaft 12 and therefore may be arbitrarily shaped as long as they have this property.

6 shows a fastening system 10 which is also the one above in 4 realized second solution principle realized. In this variant is to simplify the installation of the fastening system 10 the component 50 , In the embodiment of the cable lug, rotatable and captive on the mother 14 held. For this purpose are on the cable lug 50 at least two axially extending retaining elements 53 trained, which the mother 14 embrace in the manner of a bead. This is the mother 14 in the exemplary embodiment with a circumferential collar 20 Mistake. Instead, the mother can 14 also be provided a circumferential recess, in which the holding elements 53 engage (not shown). Finally, instead of the holding elements 53 also be provided in a conventional manner, a circumferential bead, the on the mother 14 trained bunch 20 embraces or in the mother 14 trained circumferential recess engages (not shown).

This type of attachment of the component 50 at the mother 14 can also in fastening systems according to the invention, which realize the first solution principle (see. 2 and 3 ) are used. Then you are on the component 50 instead of the in 3 shown holding tabs 52 the described holding elements 53 or a circumferential bead and on the mother 14 the circumferential collar or the circumferential recess provided while the undercut 19 eliminated.

7 shows an embodiment of a component 50 for use with the fastening system according to the invention. The component 50 , In the embodiment, a cable lug, characterized by a fork-shaped contact surface 54 on, which is suitable and be true, the bolt shank 12 to embrace. Such a component can be mounted particularly easily. In the exemplary embodiment, the contact surface 54 with claws 21 provided according to the in 4 shown second solution principle of the present invention.

8th shows a further embodiment of a nut 14 for an inventive fastening system, which realizes the first solution principle (see. 2 ). The mother 14 is with the described radial recess 16 Mistake. The radial recess 16 has in the exemplary embodiment four vertical grooves 25 on, their vertical edges 26 as scraping edges against the surface of the radial broadening 15 Act.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 9312678 U1 [0003]

Claims (25)

Fastening system ( 10 ) for fixing an electrically conductive component ( 50 ), with a provided with an electrically insulating layer, a bolt foot ( 13 ) and a bolt shank ( 12 ), the component ( 50 ) receiving threaded bolts ( 11 ), characterized in that the fastening system ( 10 ) Medium ( 15 . 16 ; 21 ), which on the bolt shank ( 12 ) in the area of the bolt foot ( 13 ) with a mother ( 14 ) are arranged cooperatively and / or on the component ( 50 ) and that the means (s) ( 15 . 16 ; 21 ) the electrically insulating layer of the threaded bolt ( 11 ) exclusively in the area of the bolt foot ( 13 ) and make electrical contact between the threaded bolt ( 11 ) and the component ( 50 ) cause. Fastening system according to claim 1, characterized in that the bolt shaft ( 12 ) arranged as radial broadening ( 15 ) is formed, which with a radial recess ( 16 ) in the mother ( 14 ), wherein the inner diameter of the radial recess ( 16 ) at at least one area is smaller than the outer diameter of the radial broadening ( 15 ). Fastening system according to claim 2, characterized in that the radial recess ( 16 ) in the mother ( 14 ) at least one vertical groove ( 24 ) having. Fastening system according to claim 3, characterized in that two or more, preferably uniformly around the circumference of the radial recess ( 16 ) are provided distributed grooves. Fastening system according to one of claims 2 to 4, characterized in that the radial broadening ( 15 ) is designed as a circumferential collar. Fastening system according to one of claims 2 to 5, characterized in that the diameter of the internal thread of the nut ( 14 ) is greater than the diameter of the external thread of the bolt shaft ( 12 ). Fastening system according to one of claims 2 to 6, characterized in that the component ( 50 ) rotatable and captive with the nut ( 14 ) connected is. Fastening system according to claim 7, characterized in that the component ( 50 ) an opening ( 51 ), on whose inside at least two axially extending retaining tabs ( 52 ) are formed, which in a circumferential undercut ( 19 ) in the mother ( 14 ) intervene. Fastening system according to claim 7, characterized in that the component ( 50 ) at least two retaining elements ( 53 ), which one on the mother ( 14 ), circumferential collar ( 20 ) embrace. Fastening system according to claim 7, characterized in that the component ( 50 ) at least two retaining elements ( 53 ), which in one at the mother ( 14 ) provided, engage circumferential recess. Fastening system according to claim 7, characterized in that the component ( 50 ) has a circumferential flange, which in one of the nut ( 14 ) engages provided, circumferential recess or one on the mother ( 14 ) provided by the circumferential collar ( 20 ) surrounds. Fastening system according to claim 1, characterized in that on the component ( 50 ) ( 21 ) than on the inside of an opening ( 51 ), at least two claws are formed which radially into the opening ( 51 protrude), and that the clear width between the free ends of the claws ( 21 ) is at least as large as the diameter of the bolt shaft ( 12 ) in the area of the bolt foot ( 13 ). Fastening system according to claim 12, characterized in that the free ends of the claws ( 21 ) above the component ( 50 ) in the direction of the bolt shaft ( 12 ) are aligned. Fastening system according to claim 12 or 13, characterized in that the claws ( 21 ) in cross-section in approximately an S-shape or Z-shape or formed in a straight line. Fastening system according to one of claims 12 to 14, characterized in that the bolt shank ( 12 ) a radial broadening ( 15 ) used to make the electrical contact between the threaded bolt ( 11 ) and the component ( 50 ) with the claws ( 21 ) cooperates. Fastening system according to claim 15, characterized in that the radial broadening ( 15 ) is designed as a circumferential collar. Fastening system according to claim 15 or 16, characterized in that in the radial broadening ( 15 ) Recesses ( 23 ) are provided, in which the claws ( 21 ) intervene during assembly. Fastening system according to one of claims 12 to 17, characterized in that for securing the component ( 50 ) A mother ( 14 ) is provided. Fastening system according to claim 18, characterized in that the diameter of the internal thread of the nut ( 14 ) is greater than the diameter of the external thread of the bolt shaft ( 12 ). Fastening system according to claim 18 or 19, characterized in that the component ( 50 ) rotatable and captive with the nut ( 14 ) connected is. Fastening system according to claim 20, characterized in that the component ( 50 ) at least two retaining elements ( 53 ), which one on the mother ( 14 ), encompass encompassing federal government. Fastening system according to claim 20, characterized in that the component ( 50 ) at least two retaining elements ( 53 ), which in one at the mother ( 14 ) provided, engage circumferential recess. Fastening system according to claim 20, characterized in that the component ( 50 ) has a circumferential flange, which in one of the nut ( 14 ) engages provided, circumferential recess or one on the mother ( 14 ) provided by the circumferential collar ( 20 ) surrounds. Fastening system according to one of the preceding claims, characterized in that the component ( 50 ) a fork-shaped contact surface ( 54 ) having. Fastening system according to one of the preceding claims, characterized in that the component ( 50 ) is designed as a cable lug.