Cable lug for an electrical contact screw in a motor vehicle

Abstract

The invention relates to a cable lug (10) for an electrical contact screw connection (12) in a motor vehicle, with at least one cable receptacle (14) for receiving a cable (16) and with a contact lug (18) for contacting the cable lug (10) with an electrical contact (20), wherein the contact lug (18) has an opening (22) for receiving a screw element (24), and wherein a top surface (26) of the contact lug (18) faces a retaining element (28) of the screw element (24) in the arranged state, characterized in that a bottom surface (30) of the contact lug (18), which is opposite the top surface (26), has a planar structure (32), wherein the structure (32) faces the electrical contact (20) in the arranged state.

Description

[0001] The following invention relates to a cable lug for an electrical contact screw connection in a motor vehicle, with at least one cable receptacle for receiving a cable and with a contact lug for contacting the cable lug with an electrical contact, wherein the contact lug has an opening for receiving a screw element, and wherein a lug top side of the contact lug faces a holding element of the screw element in the arranged state.

[0002] Cable lugs designed to make contact with electrical contacts are already known from the prior art. In particular, such a cable lug can be used, for example, in the case of an electrical ground. The cable lug has a cable receptacle for making electrical contact with a cable. The cable can be crimped onto the cable receptacle. Furthermore, the cable lug then in turn has a corresponding, essentially flat contact lug, which can also be referred to as a contact tab. The contact tab in turn can have an opening, for example, and the contact tab is then designed to make electrical contact with the electrical contact. A screw connection can in turn be established between the cable lug itself and the electrical contact via the opening. An electrical connection can thus be established between the cable and the electrical contact via the cable lug.

[0003] Particularly with high-performance electrical connections, such as the electrical ground in a vehicle, it is important to prevent the electrical contact screw connection from being unscrewed. Tightening the screw connection can exert corresponding forces on the cable lug, thus preventing the initial possibility of twisting. However, twisting may still occur due to the cable's leverage on the cable lug.

[0004] It is therefore necessary to prevent the cable lug from twisting relative to the electrical contact.

[0005] DE 298 23667 U1 relates to a screw connection that can be secured against twisting on a structure provided with a bore and a screw bolt with an external polygonal head, in particular a hexagon head screw, and a locking plate with a centrally assigned hole.

[0006] The object of the present invention is to provide a cable lug by means of which twisting of the cable lug relative to an electrical contact can be prevented.

[0007] This object is achieved by a cable lug according to the independent patent claim. Advantageous embodiments are specified in the subclaims.

[0008] One aspect of the invention relates to a cable lug for an electrical contact screw connection in a motor vehicle, having at least one cable receptacle for receiving a cable and having a contact lug for contacting the cable lug with an electrical contact, wherein the contact lug has an opening for receiving a screw element, and wherein a lug top side of the contact lug faces a holding element of the screw element in the arranged state.

[0009] It is provided that a tab underside of the contact tab, which is opposite the tab top side, has a flat structure, wherein the structure faces the electrical contact in the arranged state.

[0010] In particular, an unintentional loosening of the electrical contact screw connection due to an unplanned force acting on the cable lug, for example during operating loads in the motor vehicle, can be made significantly more difficult or avoided by an increase in loosening forces due to the increase in the friction coefficient in the parting line / structure.

[0011] The flat microstructure, particularly the microstructure, on the contact surface, i.e., the underside of the lug, which can be applied to the cable lug using laser technology or stamping, increases the mechanical robustness for force absorption in the electrical screw connection. At the same time, the flat microstructure represents a suitably dimensioned electrical contact surface, so that the electrical function remains at a consistently low level with regard to the long-term stability of the connection resistance, under all aging aspects, such as temperature changes and corrosion stress, and is comparable to today's series release.

[0012] A correspondingly machined structure, such as the cable lug now features, increases the robustness of an electrical contact screw connection against accidental loosening by a factor of 2.5 to 3, for example, without the need for additional measures, such as increasing the preload force, while maintaining long-term stability of the connection resistance. A structured cable lug can be used universally and specifically for connections defined as critical. The application range extends from connections of an equipotential bonding line to a high-voltage component housing or to low-voltage ground bolts made of steel or aluminum.

[0013] According to an advantageous embodiment, the structure is applied to the underside of the flag using a laser process. In particular, the structure can thus be applied to the underside of the flag in a simple manner and using a corresponding laser process.

[0014] Another advantage is that the structure is applied to the underside of the flag using an embossing process. This allows the structure to be applied to the underside of the flag using, for example, an embossing die. This is a very simple process that can be carried out with minimal effort.

[0015] A further advantageous embodiment provides that the cable lug is designed for a ground contact in the motor vehicle. In particular, the ground contact is a safety-critical electrical contact that must be protected from loosening. This allows the friction coefficient of the ground wire to be increased, thus ensuring reliable operation of the motor vehicle.

[0016] It is also advantageous if the flat structure is designed as a point structure. In other words, the flat structure has a multitude of point elevations and / or depressions. This makes it possible, in particular, to increase the coefficient of friction accordingly.

[0017] It is also advantageous if the flat structure is designed as a linear structure. In particular, this allows corresponding lines with elevations and depressions to be provided. This also allows the increase in friction coefficient to be achieved in a simple manner.

[0018] A further advantageous embodiment provides for the planar structure to be designed as a pyramid structure. The pyramid structure, in particular, allows for interlocking of the planar structure with the surface of the electrical contact. This allows for an increase in the coefficient of friction.

[0019] It is also advantageous if the flat structure is designed as a waffle structure. The waffle structure also allows for the corresponding interlocking. The waffle structure is also easy to apply, allowing for a simple structure on the underside of the flag.

[0020] In a further advantageous embodiment, the planar structure can be designed as a noise structure. In particular, the planar structure can be designed as an embossed noise structure. In this case, corresponding elevations and depressions are distributed substantially unevenly. This allows for a simple yet reliable increase in the coefficient of friction.

[0021] A further advantageous embodiment provides for an additional flat structure to be formed on the upper side of the flag. This also protects the upper side of the flag, and in particular the corresponding retaining element, from twisting. However, it is important that the flat structure and the additional flat structure do not destabilize the electrical contact, but rather simply increase the coefficient of friction accordingly.

[0022] A further aspect of the invention relates to an electrical contact connection for a motor vehicle. Furthermore, the invention also relates to a motor vehicle with an electrical contact screw connection. The motor vehicle can be designed, for example, as an at least partially electrically powered motor vehicle or a fully electrically powered motor vehicle.

[0023] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0024] Showing: Fig. 1 is a schematic perspective view of an embodiment of a cable lug; Fig. 2 a schematic sectional view of an embodiment of an electrical contact screw connection with an embodiment of a cable lug; Fig. 3 is a schematic plan view of an underside of an embodiment of a cable lug; Fig. 4 is a further schematic plan view of a bottom side of a cable lug; and Fig. 5 a further schematic plan view of an underside of an embodiment of a cable lug.

[0025] In the figures, identical or functionally identical elements are provided with the same reference numerals.

[0026] Fig. 1 shows a schematic perspective view of an embodiment of a cable lug 10. The cable lug 10 is used to produce an electrical contact screw connection 12 ( Fig. 2) in a motor vehicle not shown. The cable lug 10 has at least one cable receptacle 14 for receiving a cable 16. Furthermore, a contact lug 18 is shown for contacting the cable lug 10 with an electrical contact 20 ( Fig. 2), wherein the contact lug 18 has an opening 22 for receiving a screw element 24 ( Fig. 2), and wherein a flag top 26 of the contact flag 18 is connected to a holding element 28 ( Fig. 2) of the screw element 24 in the arranged state.

[0027] It is intended that a flag underside 30 ( Fig. 2) the contact lug 18, which is opposite the lug top side 26, a flat structure 32 ( Fig. 2), wherein the planar structure 32 in the arranged state faces the electrical contact 20, in particular is in contact with the electrical contact and contacts it.

[0028] Fig. Figure 2 shows a schematic sectional view of an embodiment of the electrical contact screw connection 12. In the present exemplary embodiment, the cable lug 10 is screwed to the electrical contact 20 via the screw element 24. The retaining element 28 can be designed, for example, as the screw head of the screw 24. Alternatively, the retaining element 28 can also be screwed onto a screw body 34, for example, as a nut.

[0029] Fig. Figure 3 again shows a schematic plan view of the lug underside 30 of the cable lug 10. In this case, a view of the planar structure 32 is shown. In the following exemplary embodiment, the planar structure 32 is designed as a dot structure. It can be provided that the structure 32 is applied to the lug underside 30 using a laser process. Alternatively, the structure 32 can be applied to the lug underside 30 using an embossing process.

[0030] Fig. 4 shows a further alternative embodiment of the cable lug 10, wherein in particular the planar structure 32 is essentially designed as a linear structure.

[0031] Fig. Figure 5 shows a further schematic plan view of an embodiment of the cable lug 10. In the present exemplary embodiment, the planar structure 32 is designed, in particular, as a pyramid structure. Alternatively or additionally, the planar structure 32 can also be designed as a waffle structure.

[0032] Fig. 6 again shows a further embodiment of the cable lug 10, in particular on the underside 30 of the lug with the planar structure 32. In the following embodiment, the planar structure 32 is designed in particular as a noise structure.

[0033] Furthermore, it can also be provided that a further flat structure is additionally formed on the upper side 26 of the flag.

[0034] In particular, the Fig.1 - 6 that, for example, on the underside 30 of the flag, for example a ground connection, the planar structure 32 is attached, in particular in the form of a microstructure, or the underside 30 of the flag is produced with the microstructure, so that twisting of the elongated ground connection flag via the cable 16 and / or the flag itself is prevented or at least reduced.

[0035] The idea is based on the realization that despite high screwing forces due to the elongated shape of the connection, even slight transverse forces from the lever can cause the firmly screwed lug, in particular the cable lug 10, to twist. As the cable lug 10 rotates, the screw on it also rotates and can thus unscrew, which no longer ensures the secure ground connection. Therefore, the microstructure can prevent twisting between the contact lug 18 and the electrical contact 20 by increasing the friction coefficient. Depending on the material combination, the microstructure on the underside 30 of the contact lug 18 can dig or wedge into the usually soft material of, for example, the ground potential.

[0036] In the present embodiments, the ground connection, in particular, is structured directly on the underside 30 of the lug, since the screw itself can usually be tightened sufficiently and thus securely. The elongated shape and, above all, the cable 16 at the ground connection lead to a twisting of the cable lug 10, particularly relative to the ground potential connection, even with small transverse forces due to the leverage effect. As a result, the screw / nut located on it rotates with the tab and can unscrew. This must be prevented by increasing the coefficient of friction between the cable lug 10 and the ground potential / electrical contact 20 itself through the microstructure.Particular attention must be paid to ensuring that the electrical conductivity at this point between the cable lug 10 and the electrical contact 20 is maintained and not reduced, since otherwise not only mechanical problems but also electrical ones may occur due to the reduced ground contact. List of reference symbols 10 cable lugs 12 electrical contact screw connections 14 Cable holder 16 cables 18 Contact flag 20 electrical contact 22 Opening 24 screw element 26 Flag top 28 Holding element 30 Flag underside 32 Structure 34 screw bodies QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 298 23667 U1

[0005]

Claims

[1] Cable lug (10) for an electrical contact screw connection (12) in a motor vehicle, with at least one cable receptacle (14) for receiving a cable (16) and with a contact lug (18) for contacting the cable lug (10) with an electrical contact (20), wherein the contact lug (18) has an opening (22) for receiving a screw element (24), and wherein a lug top side (26) of the contact lug (18) faces a holding element (28) of the screw element (24) in the arranged state, characterized by that a flag underside (30) of the contact flag (18), which is opposite the flag upper side (26), has a flat structure (32), wherein the structure (32) faces the electrical contact (20) in the arranged state. [2] Cable lug (10) according to claim 1, characterized by that the structure (32) is applied to the underside (30) of the flag by means of a laser process. [3] Cable lug (10) according to claim 1, characterized bythat the structure (32) is applied to the underside (30) of the flag by means of an embossing process. [4] Cable lug (10) according to one of the preceding claims, characterized by that the cable lug (10) is designed for ground contact in the motor vehicle. [5] Cable lug (10) according to one of the preceding claims, characterized by that the planar structure (32) is designed as a point structure. [6] Cable lug (10) according to one of claims 1 to 4, characterized by that the planar structure (32) is designed as a linear structure. [7] Cable lug (10) according to one of claims 1 to 4, characterized by that the planar structure (32) is designed as a pyramid structure. [8] Cable lug (10) according to one of claims 1 to 4, characterized by that the flat structure (32) is designed as a waffle structure. [9] Cable lug (10) according to one of claims 1 to 4, characterized bythat the planar structure (32) is designed as a noise structure. [10] Cable lug (10) according to one of the preceding claims, characterized by that a further flat structure is additionally formed on the upper side (26) of the flag.

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