DE102008046603A1 - Lackschabmutter - Google Patents

Abstract

The present invention relates to a paint-lock nut (1) for fastening a ground cable to a ground bolt (4), with an internal thread (2) which is complementary to an external thread (3) of the bolt (4). Essential to the invention is that the internal thread (2) of Lackschabmutter (1) has a Gewindeanomalie (5) which is designed so that when screwing the Lackschabmutter (1) on the outer thread (3) of the ground bolt (4) this one covering Removes paint layer.

Description

The The present invention relates to a paint locknut for mounting a ground cable to a ground bolt according to the preamble of the claim 1. The invention also relates a ground contact arrangement with at least one paint damper nut and a method for producing such a paint-lock nut.

Around connect electrical loads in a motor vehicle with a mass to be able to are common So-called ground bolt with an external thread on the vehicle body arranged, in particular welded. A connection of an electrical return with the ground bolt takes place via a cable lug, which is fixed with a screwed onto the ground bolt nut. Usually is doing in the painting of the body shell of the ground bolt and the nut screwed on, with the ones from the mother hidden thread surface of the ground bolt during of the painting process should remain free of paint, so that in this Contact area made a good electrical contact to the body can be. After painting, the nut is unscrewed, around the protected Release contact area. In practice, however, shows that the paint protection by the mother partially failed, since the contact area while the paint is infiltrated by penetrating paint, which means that this later must be mechanically reworked to the electrical conductivity restore. Another possibility, a contact area between nut and ground bolt, it is the mother as a so-called paint Schabmutter form, which when screwing on the external thread of the mass bolt a covering this Removes paint layer and thereby produces a bare metallic contact.

The present invention employs dealing with the problem, for a paint bushing of the generic type an improved embodiment specify which, in particular, an improved paint clearing effect having.

This Problem is inventively the subject of the independent Claim 1 solved. Advantageous embodiments are Subject of the dependent Claims.

The The invention is based on the general idea of a thread anomaly provided, for example in the form of a deviation in the thread angle, in the thread pitch or in the thread crest height between internal thread and external thread nut and bolt, and thus a significantly improved paint removal when unscrewing the paint damper nut to achieve a ground bolt.

The Thread anomaly can be consistently on the correspondingly weak expression on the entire thread length be trained or stronger shaping be formed locally limited.

at localized thread anomalies, the anomaly is preferable in a second or a second thread following thread or to set threads, so that a problem-free unscrewing the paint damper nut on the Ground bolt through a faultless first or second thread continue to be guaranteed can.

By the invention provided thread anomaly on the one hand achieves a paint removal improving effect On the other hand, this effect with the simplest mechanical Means is to be achieved, so that the cost of a Lackschabmutter invention is not or only insignificantly from the manufacturing costs of previous Lackschabmuttern differ.

Is appropriate the thread anomaly in the manner of reduced or increased thread pitch and / or an elevated one Thread ridge height and / or a different thread angle. Already this list shows that in principle there are many possibilities, one such Thread anomaly to create, with all possibilities in common is that this with the simplest mechanical means and therefore very inexpensive too generate.

at a further advantageous embodiment of the solution according to the invention the thread anomaly in the area of a closed end of an in Axial direction of Lackschabmutter extending Sacknut provided. This offers a particularly simple possibility of such a thread anomaly, this means a thread defect, for example, by a punch tool introduced into the one-sided open Sacknut and against one on the closed End of the blind groove extending thread is pressed, so that this deformed accordingly. The paint Schabmutter invention, can thereby in a stamping tool simply with a corresponding press stamping pressure be applied, which presses the desired thread anomaly.

An improvement of the scraping effect of the mother can also be achieved in that the ground bolt with a thin organic layer such. B. Teflon is coated. As a result, the paint separation in the cathodic Tauchla hampering. The deposition of further lacquer layers is also impaired. The thin organic layer acts as a predetermined breaking point between the metallic surface of the bolt and the paint during scraping and displacement of the paint or paint residues by the Schabmutter. Due to the high surface pressures when tightening the Schabmutter the contact resistance between the Schabmutter and ground stud is not appreciably affected by the thin organic layer.

Also for softer bolt materials than steel, z. B. Al and Mg alloys This reduction in paint adhesion allows removal of the paint layer without the metallic surface of the Bolzens is injured.

One another advantage of reducing paint adhesion is that the thread anomaly reduces to improve the scraping effect can be. This will damage the metallic surface of the Bolts less likely and the corrosion resistance of the bolt is not affected.

Further important features and advantages of the invention will become apparent from the Dependent claims, from the drawings and from the associated description of the figures the drawings.

It it is understood that the above and the following yet to be explained features not only in the specified combination, but also in other combinations or alone, without to leave the scope of the present invention.

preferred embodiments The invention are illustrated in the drawings and in the following description explains where like reference numerals refer to the same or similar or functionally identical components relate.

there show, in each case schematically,

1 a view from below of a paint invention patent,

2a a sectional view through the Lackschabmutter along the cutting plane FF,

2 B a sectional view through the Lackschabmutter along the cutting plane AA,

3a , b show various views of a possible embodiment of a press ram for introducing a thread anomaly into the internal thread of the paint lock nut,

4a to 4c possible manufacturing steps for producing the thread anomaly in the internal thread of the paint lock nut with a press die,

5a a view of a further embodiment of the paint lock nut,

5b a sectional view through the paint damper nut after 5a in the section plane AA,

6 an oblique view of the paint damper nut after 5a ,

Corresponding 1 has a paint brush nut according to the invention 1 an internal thread 2 on, which is complementary to an external thread 3 a mass bolt 4 (see 2a ) is formed, so that the paint damper nut 1 on the ground bolt 4 can be screwed on. The paint damper nut 1 serves the attachment of a ground cable, not shown, for example in a motor vehicle, on the ground bolt 4 and thus enables an electrical return.

The ground bolt 4 is usually arranged on a vehicle body, in particular welded, wherein in a subsequent painting process the paint damper nut 1 already on the external thread 3 of the mass bolt 4 can be screwed to a through the paint Schabmutter 1 covered threaded area of the ground bolt 4 to protect against a paint layer. This has the particular purpose, a ground cable safely electrically conductive with the ground pin 4 to be able to connect. After painting, the paint damper nut is used in the further production 1 unscrewed and thereby the not covered by a layer of paint thread area of the external thread 3 of the mass bolt 4 exposed. In this thread region, which is not covered by the lacquer layer, the contacting of the ground cable with the ground bolt takes place later 4 ,

The paint brush nut according to the invention 1 now points in its internal thread 2 a localized thread anomaly 5 on, which is designed so that when unscrewing the Paint Schabmutter 1 on the external thread 3 of the mass bolt 4 the resist coating layer is removed, so that a reliable electrical contact between the Lackschabmutter 1 and a ground cable with the ground stud 4 can be guaranteed.

It is also conceivable that the ground bolt 4 initially painted together with the vehicle body, without the paint damper nut 1 on the ground bolt 4 is screwed on, leaving a first time unscrewing the paint damper nut 1 on the external thread 3 of the mass bolt 4 only after completion of painting done. In this case, the paint-scraping effect of the paint-lock nut 1 so large that a reliable contact can be guaranteed.

The thread anomaly 5 may be formed in the manner of a reduced or increased thread pitch and / or an elevated thread crest height and / or a different thread angle. Each of these thread errors prevents the lacquer layer on the external thread 3 of the mass bolt 4 gentle screwing movement. The improper meshing with the thread error or thread anomaly 5 equipped internal thread 2 on the external thread 3 of the mass bolt 4 leads to scratching, that is, erosion of the paint layer, resulting in completely on the ground bolt 4 screwed on paint damper nut 1 a bare metallic connection and thus a reliable electrical contact between the two components is given.

The thread anomaly 5 can according to the embodiments in the 1 to 3 in the region of a closed end of a in the axial direction of the Lackschabmutter 1 running blind groove 6 be arranged. This facilitates in particular the production of such a thread anomaly 5 , because for the production of the same only a press ram 7 axially into the paint lock nut 1 can be introduced and does not have to be introduced at an angle.

This thread anomaly is made 5 by an initial introduction of the in the axial direction of the paint Schabmutter 1 running blind groove 6 in the internal thread 2 , After the introduction of the blind groove 6 is by means of the in the blind groove 6 introduced press stamp 7 a to the closed end of the blind groove 6 subsequent thread 8th deformed so that this when unscrewing the Lackschabmutter 1 on the ground bolt 4 removes a coating layer covering this. The press stamp 7 along with the bag groove 6 causes the thread anomaly 5 not in a screw thread in the front thread of the internal thread 2 is arranged so that unscrewing the paint lock nut 1 on the external thread 3 of the mass bolt 4 not disabled in any way.

Parallel to the blind groove closed on one side 6 can Lackschabnuten 9 on the internal thread 2 the paint damper nut 1 be arranged, which in particular have the task, one by the paint-lock nut 1 removed paint removal. These Lackschabnuten 9 can, for example, in the circumferential direction uniformly on the internal thread 2 be distributed, as for example in 1 and 3b is shown.

Looking at the 2a , it stands out that the blind groove 6 until the third thread 8th enough, so that when pressing the press ram 7 in the bag groove 6 the third thread 8th deformed while the crucial thread anomaly 5 will be produced. Of course, the blind groove thereby also extend to a fifth or further thread, it being advantageous, the blind groove 6 to arrange already on a thread following the front threads, that when unscrewing the paint shoe nut 1 on the ground bolt 4 the largest possible paint removal can take place.

In the 3a and 3b is a possible embodiment of such a press ram 7 shown, which three extending in an axial direction longitudinal ribs 10 has, in the Lackschabnuten 9 the paint damper nut 1 intervention. Another longitudinal rib 10 ' creates the thread anomaly 5 when inserting the same in the blind groove 6 ,

In the 4a to 4c is the production of thread anomaly 5 shown. According to 4a is shown as the press stamp 7 into the paint damper nut 1 introduced and through the longitudinal ribs 10 is guided in the associated Lackschabnuten, wherein the longitudinal rib 10 ' like this in 4c is shown when pressed into the internal thread 2 the paint damper nut 1 the thread 8th deforms and thereby the lacquer-removing thread anomaly 5 generated.

Another possibility for producing a thread anomaly according to the invention 5 is in the 5 and 6 shown, in this solution, first in the Paint Schabmutter 1 an axially extending central passage opening 11 is stamped, which has a radially inwardly projecting and extending in the axial direction longitudinal nose 12 having. Subsequently, the internal thread 2 in the passage opening 11 incised, being in the region of the longitudinal nose 12 the incised internal thread 2 an at least slightly raised thread crest 13 which, when screwing the paint-on nut 1 on the ground bolt 4 ensures that a layer of varnish covering it is removed. It is conceivable that the longitudinal nose 12 has an edged contour, as in the detailed representation B for 5a is shown by a solid line or a rounded contour, as shown with broken line drawn. In his design should be the raised thread crest 13 However, do not significantly exceed the thread layer, as a result of a possible injury to the external thread 3 of the mass bolt 4 applied Corrosion protection layer could be given. In general, the abraded paint particles also intensify the further paint removal effect, as is the case with a paint seal nut 1 according to the 1 to 4 the case is.

It is particularly advantageous that the manufacturing process of this axially continuous, locally elevated thread crest 13 works without new process steps in cold extrusion and thread cutting. In addition, both solutions have in common that thread anomalies 5 can be produced with low clamping effect and at the same time large paint clearing effect. The improved paint removal leads to a favorable power transfer from the internal thread 2 on the previously painted external thread 3 of the mass bolt 4 , which is possible even with very small tightening torques. At the same time, a deterioration of the corrosion properties of internal thread 2 and external thread 3 unaffected.

1

Lackschabmutter

2

inner thread

3

external thread

4

earth stud

5

thread anomaly

6

blind groove

7

press die

8th

thread

9

Lackschabnut

10

longitudinal rib

11

Through opening

12

longitudinal nose

13

thread ridge

Claims (9)

Paint damper nut ( 1 ) for attaching a ground cable to a ground bolt ( 4 ), with an internal thread ( 2 ), which is complementary to an external thread ( 3 ) of the mass bolt ( 4 ), characterized in that the internal thread ( 2 ) of the paint locknut ( 1 ) a thread anomaly ( 5 ), which is designed so that when screwing the Lackschabmutter ( 1 ) on the external thread ( 3 ) of the mass bolt ( 4 ) removes a coating layer covering this. Painted damper according to claim 1, characterized that a thin one organic layer, e.g. As Teflon, the adhesion and the thickness of applied Paint layers on the bolt diminished, and thereby the scraping action is improved. Painted locknut according to claim 1, characterized in that the thread anomaly ( 5 ) is formed in the manner of a reduced or increased thread pitch and / or an increased thread crest height and / or a different thread angle. Paint seal nut according to claim 1 or 2, characterized that the thread anomaly throughout the thread length is trained. Paint stripping nut according to claim 1 or 2, characterized characterized in that the thread anomaly formed locally limited is. Painted damper according to claim 5, characterized in that the thread anomaly ( 5 ) in the region of a closed end of a in the axial direction of the paint Schabmutter ( 1 ) running blind groove ( 6 ) is arranged. Ground contact arrangement with at least one paint lock nut ( 1 ) according to one of claims 1 to 7. Method for the production of a paint locknut ( 1 ) according to claim 7, in which - a in the axial direction of the Lackschabmutter ( 1 ) running and closed on one side blind groove ( 6 ) in the internal thread ( 2 ) of the paint locknut ( 1 ) is introduced, - by means of a in the blind groove ( 6 ) introduced stamp ( 7 ) at the closed end of the blind groove ( 6 ) running thread ( 8th ) is deformed in such a way that this when screwing the Lackschabmutter ( 1 ) on the external thread ( 3 ) of the mass bolt ( 4 ) removes a coating layer covering this. Method for the production of a paint lock nut according to claim 1 or 2, in which - in the paint lock nut ( 1 ) an axially extending central passage opening ( 11 ) is punched, wherein the passage opening ( 11 ) a radially inwardly projecting and extending in the axial direction longitudinal nose ( 12 ), - an internal thread ( 2 ) in the passage opening ( 11 ) is cut, - in the region of the longitudinal nose ( 12 ) the incised internal thread ( 2 ) has an at least slightly increased thread crest height, which when screwing the paint-on nut ( 1 ) on the external thread ( 3 ) of the mass bolt ( 4 ) a coating layer covering this.