EP3490074A1 - System for contacting a screen of a cable - Google Patents

Abstract

An arrangement for contacting an electrical screen of a cable is proposed. The cable has a cable core which is surrounded by the screen. The assembly comprises a first contact element (107) having a conical outer surface (119). In addition, a second contact element (108) is provided which has a conical inner surface (123) which is adapted to the conical outer surface (119) of the first contact element (107), that an end portion of the screen (104) between the conical outer surface and the conical inner surface is clamped with clamping means. The two contact elements (107, 108) contact the screen (104). In the first and / or second contact element (108), a receptacle (201) for at least one further cable (203) is provided. Furthermore, a shield connection is proposed which comprises a cable with a wire and a screen and an arrangement for contacting the screen. Finally, a method for producing the shield connection is proposed.

Description

area

The invention relates to an arrangement for contacting a screen of a cable, in particular a high-voltage cable, as well as a shield connection with such an arrangement and a method for producing a shield connection.

background

High voltage cables generally have an inner cable core and a shield separated by an insulating layer from the cable core, which is usually grounded. The screens are usually formed by a tubular closed around the cable core aluminum foil or by a plurality of wires made of copper and increasingly of aluminum. In the following, cables are considered whose screens are formed in particular from a tubular aluminum foil closed around the cable core. The connection of such a high voltage cable to, for example, the housing of an electrical set or to another high voltage cable thus requires contacting both the cable core and the screen.

Conventionally, the connection of the screen takes place by means of electric welding. In this case, a considerable know-how of the assembly personnel and a considerable technical effort are required to ensure a reliable current-carrying connection without undue stress on the screen and the insulation of the cable. In addition, there is an increased risk of fire during welding work.

From the EP 2 874 236 A1 is a contacting device for contacting a cable shield known. The contacting device has two annular contact elements, one of which has a conical outer surface and the other an opposing conical inner surface, between which a cable shield of a cable, in particular a high-voltage cable is contactable. The contact elements are clamped together by clamping screws and make in this way an electrically conductive contact to the cable shield ago.

On this basis, a first object of the present invention to provide a further improved arrangement for contacting a screen or cable shield and a corresponding shield connection and their preparation.

Summary of the invention

To achieve this object, the invention proposes according to a first aspect of an arrangement for contacting an electrical screen of a cable having an insulated conductor, which is designed as a cable core (102) which is surrounded over its entire length by the screen. The assembly includes a first contact member having a central passage for the cable and a conical outer surface. Furthermore, the arrangement has a second contact element, which has a central passage for the cable and a conical inner surface opposite the conical outer surface, which is adapted to the conical outer surface of the first contact element such that an end region of the screen between the conical inner surface and the conical outer surface is braced and contactable. There are provided clamping means for clamping the first and the second contact element with each other. The arrangement according to the invention is characterized in that a receptacle for at least one further cable is provided in the first and / or the second contact element. This design has the advantage that relatively little space is required in relation to the introduced conductor cross-section. In addition, it is possible to run the other cable parallel to the cable, the screen is contacted, which also has a favorable effect on the required space.

In an expedient embodiment, the contact elements are cylindrical and each have a cylinder jacket.

In one embodiment, the assembly additionally comprises a protective tube which extends over the cable and in this way can protect against external damage.

In an expedient development, the protective tube has a receptacle for a further cable.

In a particularly advantageous embodiment, the receptacle is adapted to produce an electrically conductive connection to the other cable. The recording makes it possible that the screen can be contacted in an advantageous manner with another cable. In a modified embodiment, a plurality of receptacles for a plurality of other cables may be provided, which allow a relatively concentric conductor guide, which also has a favorable effect on the required installation space, especially if a large conductor cross-section is required to ensure high current carrying capacity.

In an expedient development, the electrically conductive connection to the further cable is produced by means of a screw contact. The electrically conductive connection between the screen and the other cable is thus easy to manufacture and in particular requires no special tools or special equipment such as welding equipment.

In order to ensure a uniform quality of the electrical connection, in one embodiment, the screw contact comprises a clamping screw with tear-off. This ensures that the tightening torque is always the same without a fitter must have a torque wrench available for this purpose.

Advantageously, the receptacle is produced by a bore in the first and / or second contact element and / or the protective tube. This type of recording is manufacturing technology particularly easy to implement.

In an alternative embodiment, the receptacle is made by a flat area on the outer peripheral surface of the first and / or second contact element and / or the protective tube. Conveniently, threaded holes are provided in the flat area, so that another cable can be electrically contacted by a screw connection. The availability of different recordings gives the arrangement according to the invention additional flexibility with respect to the type of contact pieces, with which more cables are contacted, whereby the arrangement is adaptable to different applications

Appropriately, can be provided as clamping means clamping screws which extend between the first and the second contact element.

According to a second aspect of the invention, there is proposed a shield connection comprising an assembly according to any one of the preceding claims and a cable having a cable core surrounded by a screen along its entire length. The screen is received in the arrangement for contacting. Since an arrangement according to the first aspect of the present invention is used for the shield connection, all the advantages mentioned in connection with the arrangement are also realized by the shield connection.

• Bereitstellen eines Kabels, das eine Kabelader aufweist, die auf ihrer ganzen Länge von einem Schirm umgeben ist;
• Bereitstellen einer Anordnung nach dem ersten Aspekt der Erfindung;
• Aufschieben des zweiten Kontaktelementes auf das Kabel;
• Herstellen eines Hohlraumes unter dem Schirm an einem Endabschnitt des Kabels;
• Aufschieben des ersten Kontaktelementes auf das Kabel, sodass der aufgeweitete Schirm auf der konischen Außenfläche des ersten Kontaktelementes zu liegen kommt;
• Heranschieben des zweiten Kontaktelementes an das erste Kontaktelement, sodass der aufgeweitete Schirm zwischen der konischen Außenfläche des ersten Kontaktelementes und der konischen Innenfläche des zweiten Kontaktelementes zu liegen kommt; und
• Verspannen der Kontaktelemente miteinander.

According to a third aspect, there is also proposed a method for producing a shield connection according to the second aspect of the invention. The method comprises the steps:

• Providing a cable having a cable core surrounded by a screen along its entire length;
• Providing an arrangement according to the first aspect of the invention;
• Pushing the second contact element onto the cable;
• Forming a cavity under the screen at an end portion of the cable;
• Pushing the first contact element onto the cable, so that the expanded screen comes to rest on the conical outer surface of the first contact element;
• Pushing the second contact element against the first contact element so that the expanded screen comes to rest between the conical outer surface of the first contact element and the conical inner surface of the second contact element; and
• Clamping the contact elements together.

• Aufschneiden des glatten Schirms in mindestens zwei Streifen
• oder konisches Aufweiten des glatten Schirms.

If the cable has a smooth screen, according to an advantageous development of the method prior to the production of the cavity under the screen, the following additional step is additionally performed:

• Slicing the slippery screen into at least two strips
• or conical widening of the smooth screen.

Short description of the drawing

Fig. 1

ein Ausführungsbeispiel einer erfindungsgemäßen Anordnung teilweise im Querschnitt;

Fig. 2A

eine andere Ansicht der Anordnung aus Figur 1 in einer perspektivischen teilweise aufgebrochenen Darstellung;

Fig. 2B

eine Draufsicht auf einen Gegenhalter der erfindungsgemäßen Anordnung;

Fig. 3

ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Anordnung teilweise im Querschnitt;

Fig. 4

ein schematisches Flussdiagramm für ein Verfahren zur Herstellung einer erfindungsgemäßen Schirmverbindung.

The invention will be explained in more detail by way of example with reference to an embodiment with reference to the accompanying figures. All figures are purely schematic and not to scale. Show it:

Fig. 1

an embodiment of an inventive arrangement partially in cross section;

Fig. 2A

another view of the arrangement FIG. 1 in a perspective partially broken view;

Fig. 2B

a plan view of a counter-holder of the arrangement according to the invention;

Fig. 3

a further embodiment of an inventive arrangement partially in cross section;

Fig. 4

a schematic flow diagram for a method for producing a shield connection according to the invention.

The same or similar elements are provided in the figures with the same or similar reference numerals.

embodiment

FIG. 1 shows an embodiment of an inventive arrangement for contacting a cable, which is designated as a whole by the reference numeral 100. The assembly 100 is mounted on a cable 101, for example a high voltage cable 101. The high voltage cable 101 has an inner cable core 102 which is surrounded by an insulating layer 103. On the insulating layer is a screen 104, which is made of a metal strip. The metal strip is made of aluminum or an aluminum alloy, although other metals, in particular copper for the production of the screen 104 come into question. An insulating jacket 106 encloses the cable 101. The high voltage cable 101 as a whole is preferably flexible, so that its components, ie the cable core 102, the insulating layer 103, the shield 104 and the outer insulating jacket 106 are flexible.

In typical applications, the high voltage cable 101 is connected to an electrical device (not shown), the z. B. may be another high voltage cable or an electrical set. It is usually necessary to electrically contact both the cable core 102 and the screen 104. In particular, in the above-described smooth umbrellas 104, which are made of a metal strip, prepares the contacting of Umbrella often difficulties, especially if more lines are to be connected to the screen 104.

The arrangement 100 serves for contacting the aluminum strip serving as screen 104. The cable core 102 is complemented by a in FIG. 1 Cable set not shown connected or connected. A mounting direction M extends from a cable end away in Fig. 1 left to right.

The arrangement 100 has a first contact element 107 and a second contact element 108. The contact element 107 is referred to below as a clamping sleeve and the second contact element 108 as a counter-holder. The two contact elements 107 and 108 are substantially cylindrical and have central passages 109 and 110, respectively. The contact elements 107 and 108 are connected to each other by means of threaded bolts 111, nuts 112 and washers 113, in particular clamped together. For this purpose, the threaded bolts 111 are screwed into threaded holes 114, which are provided in a flange 116, which is formed on the clamping sleeve 107. The threaded bolts 111 are guided through through holes 117 in the second contact element 108, so that the two contact elements 107 and 108 can be clamped together by tightening the nuts 112. The first contact element 107 may also be part of a housing of a further electrical device to which the cable 101 is connected. The contact elements 107,108 are made of a highly electrically conductive metal, preferably of aluminum alloy.

The passage 109 of the first cylindrical contact element 107 is delimited by a cylinder jacket 118 with a conical outer surface 119, which forms a first contact region. The conical outer surface 119 tapers in the mounting direction M conical, ie away from the cable end. Advantageously, the conical outer surface 119 of the first contact element 107 and / or the conical inner surface 123 of the second contact element 108 has a structuring 121, which, for. B. by sand blasting, toothing or corrugation, is formed to the effective surface and the roughness of the first contact area increase. It is advantageous if the contact element has the structuring 121, which also contains the receptacle 201 for the cables 202.

The aluminum strip 104 is advantageously formed inside the high-voltage cable 101 as a closed aluminum foil, which surrounds the cable core 102 in a tubular manner. In an area 126 in the direction of a cable longitudinal axis A, where the arrangement 100 contacts the screen 104, the insulation jacket 106 is removed from the screen 104 and the otherwise closed aluminum foil that forms the screen 104 is divided into longitudinal strips 127. The longitudinal strips 127 are radially bent slightly outwards, so that the conical outer surface 119 of the clamping sleeve 107 finds space under the longitudinal strips 127. In other words, the longitudinal strips 127 rest on the conical outer surface 119 of the contact element. As a result, the longitudinal strips 127 between the conical outer surface 119 of the clamping sleeve 107 and the conical inner surface 123 of the counter-holder 108 lie and are clamped there as soon as the nuts 112 be attracted. The structurings 121 or 123 in this case penetrate an aluminum oxide layer possibly present on the longitudinal strips 127, which may worsen or hinder the electrical contacting. As an alternative to cutting the aluminum strip, it may also be conically widened, e.g. by a likewise conically shaped drive wedge, which is driven under the aluminum tube and thus the aluminum tube widens conically with a corresponding angle to the contact element. The drive wedge is divided into several segments to gradually drive with hammer blows to a large outer diameter, the segments of the drive wedge under the aluminum tube. The drive wedge is also used when the screen is designed as a closed aluminum band.

FIG. 2A shows the arrangement 100 in a partially cutaway view and illustrates further features, which in the illustration in FIG. 1 are not visible. The cut is guided by the counter-holder 108 so that a receptacle 201 in the anvil 108 is visible. The receptacle 201 is formed as an axial blind hole in the cylinder jacket 122 of the counter-holder 108 and receives a cable core 202 of another cable 203, which is stripped at one end. A radial threaded bore 204 opens vertically in the receptacle 201. In the threaded bore 204, a clamping screw 206 is screwed, which clamps the cable core 202 of the other cable 203 and electrically connected to the anvil 108. In FIG. 2 the clamping screw 206 is shown as a screw with tear-off to limit the tightening torque with which the other cable 203 is clamped. In other embodiments, however, screws without tear-off can be used, which are tightened with a torque wrench.

The diameter of the receptacle 201 can be varied as desired within the scope of what the material thickness of the cylinder jacket 122 permits in order to electrically connect further cables of different diameters to the arrangement 100 or to the screen 104. In this case, the thickness of the cylinder jacket 102 and the diameter of the receptacle 201 are adjusted to one another in such a way that a mechanically stable screwed connection with the further cable 203 is always ensured. The same applies to the number of receptacles 201 which are provided in the counter-holder 108. In particular, not so many receptacles 201 may be provided that the mechanical stability of the counter-holder 108 is impaired.

FIG. 2B shows a further embodiment of a counter-holder 108 in a plan view, in which the receptacles are milled out of the counter-holder 108 as flat recesses 207. Radial threaded holes (not visible) are provided in the area of the recesses 207 so that a cable lug of a further cable can be screwed there.

In a further embodiment, not shown in the drawing of a counter-holder 108, the two types of receptacles 201, 207 for further cables 203 are combined, so that Depending on the application, the most suitable contact is always available.

The arrangement 100 according to the invention makes it possible to safely contact the screen of a cable by means of simple screw connections and, moreover, to connect further cables to the screen 104 by means of screw connections.

FIG. 3 shows a further embodiment of the inventive arrangement 100, which differs from the in FIG. 1 is distinguished by an additional protective tube 301 which extends over the cable 101 and protects the cable 101 from mechanical damage. On the protective tube 301, a receptacle 302 is provided, where another cable, for example a flat stranded wire 303 with a screw 304 can be fastened and makes an electrical contact to the protective tube 301. In the illustrated embodiment, the receptacle 302 is a flat radial projection with a threaded hole. In another embodiment, the receptacle 302 may also be just a threaded hole.

By mounting the assembly 100 on a cable 101 creates a shield connection which is made in detail as follows. The manufacturing process is shown in a schematic flow diagram in FIG FIG. 3 shown.

At the beginning, a cable is provided in a step S1 and an arrangement according to the invention is provided in a step S2. In a step S3, the retainer 108 is pushed onto one end of the cable 101, namely in the in FIG. 1 Then, in a step S4, the insulating jacket 106 is removed from the cable 101 to first expose the shield 104 and then widen it. If it is a smooth screen formed of a metal strip, before the screen 104 is expanded, the screen is previously divided into longitudinal strips 127 or the screen is flared. This creates a cavity under the screen. In a step S5 the clamping sleeve 107 is pushed onto the cable, so that the expanded screen 104 comes to lie on the conical outer surface 119 of the clamping sleeve 107. In a step S6, the counter-holder is pushed onto the clamping sleeve 107, so that the expanded screen 104 comes to lie between the conical outer surface 119 of the clamping sleeve 107 and the conical inner surface 123 of the counter-holder 108. Then, in a step S7, clamping sleeve 107 and anvil 108 are clamped together to make electrical contact with the screen 104.

The invention has been described in the context of a metal foil screen 104. However, the invention is also applicable to the screens of wires or of a wire mesh. In these cases, the wires or the wire mesh instead of the longitudinal strips 127 of the screen 104 between the conical outer surface 119 of the clamping sleeve 107 and the conical inner surface 123 of the counter-age 108 placed and contacted by bracing the clamping sleeve with the anvil.

In other embodiments, the cable core 102 and / or 202 is formed as strands which, when required, are provided with a crimping sleeve. Furthermore, it is not relevant for the present invention from which metal the cable core 102 or 202 are made. Suitable metals are, for example, copper and aluminum or aluminum alloys.

In principle, it is also possible that the cable core 202 is electrically connected by welding or soldering with the anvil 108. However, in contrast, screw connections with regard to the possibility of being able to connect different materials to one another and the safety of work are advantageous. <U> REFERENCE LIST </ u> 100 arrangement 101 (High voltage) cable 201 admission 102 Vein 202 cable wire 103 insulating layer 203 another cable 104 umbrella 204 threaded hole 106 insulation jacket 206 clamping screw 107 first contact element (clamping sleeve) 207 recess 108 second contact element (counterholder) 109 passage 301 thermowell 110 passage 302 admission 111 threaded bolt 303 Another cable 112 mother 304 screw 113 washer 114 threaded holes 116 flange 117 Through holes 118 cylinder surface 119 conical outer surface 121 structuring 122 cylinder surface 123 conical inner surface 126 Area 127 vertical stripes

Claims (12)

An assembly (100) for contacting an electrical shield (104) of a cable (101) having an insulated conductor formed as a cable core (102) which is surrounded by the shield (104) along its entire length, the assembly includes: - A first contact element (107) having a central passage (109) for the cable (101) and a conical outer surface (119); - A second contact element (108) having a central passage (110) for the cable (101) and an opposite to the conical outer surface (119) conical inner surface (123), which at the conical outer surface (119) of the first contact element (107) is adapted such that an end portion (126) of the screen is tensionable and contactable between the conical outer surface (119) and the conical inner surface (123); Tensioning means (111, 112, 123) for clamping the first and second contact elements (107, 108) together, characterized in that
in the first and / or second contact element (108) is provided a receptacle (201, 207) for at least one further cable (203). Arrangement according to claim 1, characterized in that the arrangement comprises a protective tube (301). Arrangement according to claim 1, characterized in that the protective tube (301) has a receptacle (302) for a further cable. Arrangement according to one of the preceding claims, characterized in that the receptacle (201, 207) is adapted to produce an electrically conductive connection to the further cable (203). Arrangement according to claim 4, characterized in that the electrically conductive connection to the further cable (203) is produced by means of a screw contact. Arrangement according to claim 5, characterized in that the screw contact comprises a clamping screw (206) with tear-off. Arrangement according to one of the preceding claims, characterized in that the receptacle (201) is produced by a bore in the first and / or second contact element (108). Arrangement according to one of the preceding claims, characterized in that the receptacle (207) is produced by a flat region on an outer peripheral surface of the first and / or second contact element (107, 108) and / or the protective tube. Arrangement according to one of the preceding claims, characterized in that the clamping means are clamping screws (111) which extend between the first and the second contact element (107, 108). A shield connection comprising an assembly as claimed in any one of the preceding claims and a cable (101) having a cable core (102) surrounded by a shield (104) along its entire length, said shield (104) being in the arrangement (Fig. 100) is received for contacting. A method of making a shield connection according to claim 10, said method comprising: - Providing a cable (101) having a cable core (102) which is surrounded over its entire length by a screen (104); - providing an arrangement (100) according to any one of claims 1-9; - Sliding the second contact element (108) on the cable (101); - Making a cavity under the screen (104) at an end portion (126) of the cable (101); - Sliding the first contact element (107) on the cable (101), so that the conical outer surface (119) of the first contact element (107) comes to lie in the cavity; - Pushing the second contact element (108) to the first contact element (107), so that the screen between the conical outer surface (119) of the first contact element (107) and the conical inner surface (123) of the second contact element (108) comes to rest; and - Spanning the contact elements (107, 108) with each other. A method according to claim 11, wherein, if the cable has a smooth screen (104), the following step is additionally performed before the cavity is made under the screen: - Cutting the smooth screen (104) in at least two strips (127) or widening of the smooth screen.

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