Data line as well as methods for producing the data line

Abstract

A data line that is designed as a coaxial cable and has a line core that extends in a line longitudinal direction. The line core has at least one conductor surrounded at least by insulation and is surrounded by a multi-layer shielding foil, which has a non-conductive layer and a conductive layer. In an overlap region, a free end edge overlaps a further partial region, wherein additionally a conductive connection of the conductive layer at the end edge to the further partial region is formed such that a transverse current flow perpendicular to the longitudinal direction within the conductive layer is enabled. The conductive connection is formed optionally as a conductive strip and/or by a beveled end edge. In particular, the data line is a data line shielded exclusively via the shielding foil. The data line is used in particular in a motor-vehicle electrical system.

Claims

1. A data line comprising: a line core extending in a longitudinal direction, the line core formed of at least one conductor and an insulation, the at least one conductor surrounded by the insulation; and a shielding foil that surrounds the insulation, wherein the shielding foil is formed of a non-conductive layer with a first conductive layer attached to an outer side of the non-conductive layer and a second conductive layer attached to an inner side of the non-conductive layer, the outer side of the non-conductive layer opposing the inner side of the non-conductive layer, wherein the shielding foil surrounds the insulation such that a first free end edge of the shielding foil overlaps a second free end edge of the shielding foil in an overlap region, wherein a region of the shielding foil directly adjacent the overlap region is an additional partial region, wherein a distal end face of a first free end edge of the first and second conductive layers is electrically conductively connected to an outer side of the first conductive layer provided in the additional partial region by an electrically conductive connection, the distal end face of the first conductive layer extending between the outer side and an inner side of the first conductive layer and the distal end face of the second conductive layer extending between an outer side and an inner side of the second conductive layer, wherein the electrically conductive connection is an additional conductive strip attached to the shielding foil so that the additional conductive strip is directly attached to the distal end face of the first and second conductive layers and to the additional partial region, so as to electrically connect the distal end face of the first and second conductive layers with the additional partial region, and wherein the additional conductive strip extends over and is directly attached to a portion of the outer side of the first conductive layer at the first free end edge, such that the additional conductive strip is substantially s-shaped in cross-section.

2. The data line according to claim 1, wherein the additional conductive strip is formed by applying a conductive material via an application method including spraying, printing, painting, or gluing.

3. The data line according to claim 1, wherein the shielding foil is formed as a longitudinally-folded foil, in which the first and second free end edges of the shielding foil run parallel to the longitudinal direction.

4. The data line according to claim 1, wherein the first and second conductive layers of the shielding foil each have a thickness in a range of 3 microns to 35 microns.

5. The data line according to claim 1, wherein the shielding foil is surface-bonded with the insulation by an adhesive layer or a hot adhesive layer, such that the adhesive layer or the hot adhesive layer is positioned between the shielding foil and the insulation.

6. The data line according to claim 1, wherein the non-conductive layer, the first conductive layer and the second conductive layer of the shielding foil are full-surface mounted on each other, and wherein despite the non-conductive layer, a completely circumferential connection is formed within the first and second conductive layers.

7. The data line according to claim 1, wherein the shielding foil, at first and second distal ends, is cohesively and electrically conductively connected with a contact element by gluing, soldering or welding.

8. The data line according to claim 1, wherein the insulation is made of a heat-resistant material that withstands a temperature of over 100 C. or over 150 C.

9. The data line according to claim 1, wherein the insulation comprises a cross-linked plastic.

10. The data line according to claim 1, wherein the data line is a coaxial cable and the shielding foil is a single shield element that forms an outer conductor, which is surrounded by an outer shell.

11. The data line according to claim 1, wherein the shielding foil is a single shield element such that no additional shielding elements are provided in the data line.

12. A data line comprising: a line core extending in a longitudinal direction, the line core formed of at least one conductor and an insulation, the at least one conductor surrounded by the insulation; and a shielding foil that surrounds the insulation, wherein the shielding foil is formed of a non-conductive layer with a first conductive layer attached to an outer side of the non-conductive layer and a second conductive layer attached to an inner side of the non-conductive layer, the outer side of the non-conductive layer opposing the inner side of the non-conductive layer, wherein the shielding foil surrounds the insulation such that a first free end edge of the shielding foil overlaps a second free end edge of the shielding foil in an overlap region, wherein a region of the shielding foil directly adjacent the overlap region is an additional partial region, and wherein a distal end face of a first free end edge of the first and second conductive layers is electrically conductively connected to an inner side of the second conductive layer provided in the additional partial region, the distal end face of the first conductive layer extending between an outer side and an inner side of the first conductive layer and the distal end face of the second conductive layer extending between an outer side and the inner side of the second conductive layer, wherein the distal end face of the first and second conductive layers is beveled, and wherein, at the beveled distal end face of the first and second conductive layers, a contact to the additional partial region is formed, such that the beveled distal end face of the first and second conductive layers is directly attached to the inner side of the second conductive layer in the additional partial region.

13. The data line according to claim 12, wherein the angle with respect to a surface normal of the shielding foil is greater than 30.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIG. 1 is a perspective view of a coaxial cable as a data line, each with partially exposed components for clarity,

(3) FIG. 2 is a partial cross-sectional view of a shielding foil with a line core in an overlap region with a conductive strip to form a conductive bridge between an end edge and a flat partial region of the shielding foil,

(4) FIG. 3 is a partial cross-sectional view of a shielding foil in the overlap region according to a second embodiment with a beveled end edge, and

(5) FIG. 4 is a simplified cross-sectional view in the end region of a data line with a contact element.

DETAILED DESCRIPTION

(6) The data line 2 shown in FIG. 1 is exemplified in the preferred embodiment of a coaxial cable. The data line 2 in this case comprises a central inner conductor 4, which is surrounded by an insulation 6 immediately and concentrically. The insulation 6 forms a dielectric. On the insulation 6, in turn a shielding foil 8 is directly and concentrically mounted, representing an outer conductor. The shielding foil is then in turn surrounded directly and concentrically by an outer shell 10.

(7) The shielding foil 8 is a longitudinally folded shielding foil 8, which is usually applied in the manufacturing process lengthwise, immediately prior to an extrusion of the outer shell 10. The shielding foil 8 thus forms an overlap region 12, which is oriented parallel to a longitudinal direction 14 of the data line 2.

(8) As shown particularly in FIGS. 2 and 3, the shielding foil 8 is a multi-layered shielding foil 8, in the embodiment, a three-layer shielding foil 8. Said shielding foil has as a carrier layer a nonconductive layer 16 and attached to both sides thereto, conductive layers 18a, 18b. Reference numeral 18a thereby designates the outwardly facing conductive layer and reference numeral 18b designates the inwardly facing conductive layer. The shielding foil 8 is in particular a laminated foil, wherein on the carrier layer 16 on both sides in particular metal layers for forming the conductive layers 18a, 18b are applied. The conductive layers 18a, 18b thereby extend over the total surface of the non-conductive layer 16. The shielding foil 8 has an overall thickness d, which is preferably <60. The two conductive layers 18a, 18b have, for example, a thickness ranging from 20 to 30 microns, and the remainder is attributed to the non-conductive layer 16 of the carrier layer.

(9) As can be seen in FIGS. 2 and 3, two longitudinal edge portions of the shielding foil 8 overlap in the overlap region 12, without either of the longitudinal edges of the shielding foil 8 being folded in that region. In the area of these longitudinal edges, the shielding foil 8 has in each case an end edge 20. In both embodiments, an electrically conductive connection of one of the two conductive layers 18a, 18b at the end edge 20 is thus formed with a flat, further partial region 22 of the same layer 18a, 18b in the overlap region 12.

(10) In the embodiment of FIG. 2, this is done by means of a conductive strip 24, which is attached to the end edge 20 and so to speak, surrounds the end edge 20 in the longitudinal direction 4 with conductive material. In this way, an electrically conductive connection and thus a conductive bridge is formed between the outer conductive layer 18a on the end edge 20 and the same conductive layer 18a in the further partial region 22. Therefore, the outer layer 18a is electrically closed, so that even in the circumferential direction, transverse currents can flow within the layer 18a.

(11) In the embodiment of FIG. 3, the end edge 20, in particular the end edge of the longitudinal edge of the shielding foil 8 lying below, is beveled in shape, so that a preferably acute angle is formed. The end edge 20 is oriented at an angle with respect to a surface normal 26, which is preferably >45 and in particular >60. By means of this measure, a region projecting beyond the central non-conductive layer 16 is formed on the lower conductive layer 18b, via which the electrically conductive connection subsequently takes place at the end edge 20 with the same lower layer 18b in the further partial region 22. In this further region 22, the shielding foil 8 thus conforms with its lower conductive layer 18b to the beveled end edge 20.

(12) In principle, the embodiments of FIGS. 2 and 3 can also be combined with one another, i.e., in addition to the conductive strip 24, the beveled end edge 20 is formed.

(13) In order to ensure a reliable, flat, permanently firm adhesion of the shielding foil 8 at the insulation 6, an adhesive layer 28 is furthermore formed which is disposed between the insulation 6 and the innermost layer 18b of the shielding foil 8. This is exemplarily illustrated in FIG. 2. The adhesive layer 28 is, for example, a hot-melt adhesive layer, which is applied on the lower conductive layer 18b of the shielding foil 8 immediately before attaching said foil. In addition to the connection with the isolation 6, an advantage is that the two longitudinal edges of the shielding foil 8 are fixed to each other in the overlap region 12 by means of the adhesive layer 28.

(14) Also, immediately subsequent to the attachment of the shielding foil 8, the outer shell 10 is applied by an extrusion method. For this purpose, a so-called shell extruder is used. Immediately in advance of the shell extrusion, the shielding foil 8 is supplied lengthwise to the shell extruder. At the same time, an application device, for example, a nozzle, etc. for the outer shell 10 is arranged in front of the extrusion head, by means of which the conductive strip 24 is applied in the region of the end edge 20.

(15) Through the heat introduced during the extrusion of the outer shell 10, the hot melt adhesive of the adhesive layer 28 is activated and the adhesive bond between the insulation 6 and the shielding foil 8 is formed.

(16) The beveled end edge 20 in the embodiment of FIG. 3 is preferably formed by means of a cutting operation. For this, a conventionally prepared shielding foil 8 is designed, for example, with the help of an inclined blade. Alternatively, a conventionally primed shielding foil 8 is beveled with perpendicular edges at the cut edges, for example by scraping.

(17) The contacting of the shielding foil 8 with a contact element 30 is exemplified in FIG. 4. The contact element 30 is preferably formed as a ring-shaped or cylindrical contact sleeve. The data line 2 is loaded with one end face freed from the outer shell 10 into the contact element 30.

(18) An annular strip of a solder paste 32 is attached on the shielding foil 8. The electric contact connection with the contact element 30 takes place via the solder paste 32. For this purpose, no pressing force is necessary. The contact connection is thus free of pressure and is cohesive.

(19) To form the electrical contact connection, in the manufacture thereof, an electric current in the area of the solder paste 32 is conveniently supplied by means of two electrodes 34, so that a short-term and local overheating occurs, so that the solder paste 32 is melted and the desired, permanently electrically conductive connection is formed. As an alternative to the solder paste 32, a conductive adhesive may be used.

(20) As an alternative to a contact sleeve, the contact element 30 is a crimp area of a conventional plug-in contact element. Such a crimping area usually forms a cage for receiving the line to be contacted. This is usually formed by crimping lugs, which project and are bent in a normal crimping process. When using such a conventional plug-in contact element with a crimp area, which are usually designed as bent sheet metal stamped parts, when using the present data line 2, crimping is omitted and only the integral connection described in regards to FIG. 4 is formed. The contact element 30 is generally a part of a plug-in contact.

(21) The data line 2 described herein is used in particular in a motor vehicle electrical system. With the measures described here, a particularly cost-effective manufacture is achieved with good shielding effect.

(22) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.