EP3490074B1 - System for contacting a screen of a cable - Google Patents

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 screen connection with such an arrangement and a method for producing a screen connection.

background

High-voltage cables generally have an inner cable core and a screen which is separated from the cable core by an insulating layer and which is generally earthed. The shields are usually formed by an aluminum foil closed in a tubular shape around the cable core or by a large number of wires made of copper and increasingly of aluminum. In the following, cables are considered whose shields 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 the contacting of both the cable core and the screen.

The shield is conventionally connected by means of electric welding. This requires a considerable amount of know-how on the part of the assembly staff and a considerable outlay in terms of equipment technology in order to ensure a reliable current-carrying connection without undue stress on the shield and the insulation of the cable. In addition, there is always an increased risk of fire during welding work.

From the EP 2 874 236 A1 a contacting device for contacting a cable shield is known. The contacting device has two ring-shaped contact elements, one of which has a conical outer surface and the other has 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 in this way produce an electrically conductive contact with the cable shield

From the US 5151053 an arrangement for contacting an electrical screen according to the preamble of claim 1 is known.

Proceeding from this, a first object of the present invention is to create a further improved arrangement for contacting a screen or cable screen, as well as a corresponding screen connection and its production.

Summary of the invention

To achieve this object, the invention proposes, according to a first aspect, an arrangement for contacting an electrical shield of a cable according to claim 1.

This design has the advantage that relatively little installation space is required in relation to the conductor cross-section. In addition, it is possible to run the further cable parallel to the cable whose screen is contacted, which also has a favorable effect on the installation space required.

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

In one exemplary embodiment, the arrangement additionally has 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.

According to the invention, the receptacle is set up to produce an electrically conductive connection to the further cable. The receptacle enables the screen to be advantageously contacted with a further cable. In a modified embodiment, several receptacles for a plurality of further cables can be provided, which allow a comparatively concentric conductor routing, which also has a favorable effect on the required installation space, especially when a large conductor cross-section is required to ensure a high current-carrying capacity.

In an expedient development, the electrically conductive connection to the further cable is established by means of a screw contact. The electrically conductive connection between the screen and the further cable is therefore easy to establish and, in particular, does not require any special tools or special devices such as welding devices.

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

The receptacle is advantageously made by a bore in the first and / or second contact element and / or the protective tube. This type of recording is particularly easy to implement in terms of production technology.

In an alternative embodiment, the receptacle is produced by a flat area on the outer circumferential surface of the first and / or second contact element and / or the protective tube. It is expedient for threaded holes to be provided in the flat area so that electrical contact can be made with another cable by means of a screw connection. The availability of different receptacles gives the arrangement according to the invention additional flexibility with regard to the type of contact pieces with which further cables are contacted, whereby the arrangement can be adapted to different applications

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

According to a second aspect of the invention, a screen connection is proposed which comprises an arrangement according to one of the preceding claims and a cable which has a cable core which is surrounded by a screen over its entire length. The screen is included in the arrangement for making contact. Since an arrangement according to the first aspect of the present invention is used for the shield connection, all of 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, a method for producing a screen connection according to the second aspect of the invention is also proposed. The procedure consists of the following steps:

• Providing a cable which has a cable core which is surrounded by a screen over its entire length;
• Providing an arrangement according to the first aspect of the invention;
• Sliding the second contact element onto the cable;
• Creating a cavity under the screen at one end portion of the cable;
• Sliding 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 up to 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
• Bracing 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, the following step is also carried out before the cavity is produced under the screen:

• Cut open the smooth screen in at least two strips
• or conical expansion of the smooth screen.

Brief 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.

In the following, the invention is explained in more detail using an embodiment example with reference to the accompanying figures. All figures are purely schematic and not to scale. Show it:

Fig. 1

an embodiment of an arrangement according to the invention partially in cross section;

Figure 2A

another view of the arrangement Figure 1 in a perspective partially broken away representation;

Figure 2B

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

Fig. 3

another embodiment of an arrangement according to the invention partially in cross section;

Fig. 4

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

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

Embodiment

Figure 1 shows an exemplary embodiment of an arrangement according to the invention for making contact with a cable, which is designated as a whole by the reference symbol 100. The arrangement 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. A screen 104, which is made from a metal strip, lies on the insulating layer. The metal strip consists of aluminum or an aluminum alloy, although other metals, in particular copper, can also be used to produce the screen 104. An insulating jacket 106 surrounds the cable 101. The high-voltage cable 101 is preferably flexible as a whole, so that its components, ie the cable core 102, the insulating layer 103, the shield 104 and the outer insulating jacket 106 are also flexible.

In typical applications, the high-voltage cable 101 is connected to an electrical device (not shown) which, for. B. can be another high-voltage cable or an electrical set. It is generally necessary to make electrical contact with both the cable core 102 and the screen 104. In particular in the case of the smooth screens 104 described above, which are made from a metal strip, the contacting of the There are often difficulties with the shield, in particular when further lines have to be connected to the shield 104.

The arrangement 100 serves to make contact with the aluminum strip serving as a screen 104. The cable core 102 is supplemented by an in Figure 1 Cable set not shown connected or connected. A mounting direction M runs from one end of the cable 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 also 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 essentially cylindrical and have central passages 109 and 110, respectively. The contact elements 107 and 108 are connected to one another by means of threaded bolts 111, nuts 112 and washers 113, in particular braced to one another. For this purpose, the threaded bolts 111 are screwed into threaded holes 114 which are provided in a flange 116 which is molded onto the clamping sleeve 107. The threaded bolts 111 are guided through through bores 117 in the second contact element 108, so that the two contact elements 107 and 108 can be braced together by tightening the nuts 112. The first contact element 107 can 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 metal with good electrical conductivity, preferably an 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 area. The conical outer surface 119 tapers conically in the assembly direction M, 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 structure 121 which, for. B. by sandblasting, serration or corrugation, is formed to the effective surface and the roughness of the first contact area increase. It is advantageous if that contact element has the structuring 121 which also contains the receptacle 201 for the cables 202.

The aluminum strip 104 is advantageously designed as a closed aluminum foil within the high-voltage cable 101, 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 bent radially slightly outward, 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. The conical inner surface 123 of the second contact element or counter holder 108 is arranged above the longitudinal strip 127, so that the result is that the longitudinal strips 127 lie between the conical outer surface 119 of the clamping sleeve 107 and the conical inner surface 123 of the counter holder 108 and are clamped there as soon as the nuts 112 get dressed by. The structuring 121 or 123 penetrate an aluminum oxide layer which may be present on the longitudinal strip 127 and which can worsen or hinder the electrical contact. As an alternative to cutting the aluminum strip, it can also be widened conically, e.g. by means of a likewise conically shaped driving wedge, which is driven under the aluminum tube and thus widens the aluminum tube conically at a corresponding angle to the contact element. The drive wedge is divided into several segments in order to gradually drive the segments of the drive wedge under the aluminum tube with hammer blows on a large outer diameter. The drive wedge is also used when the screen is designed as a closed aluminum band.

Figure 2A FIG. 10 shows the arrangement 100 in a partially cut-away representation and illustrates further features that are shown in the representation in FIG Figure 1 are not visible. The cut is made through the counter holder 108 so that a receptacle 201 in the counter holder 108 is visible. The receptacle 201 is designed as an axial blind hole in the cylinder jacket 122 of the counter holder 108 and receives a cable core 202 of a further cable 203, which is stripped at one end. A radial threaded bore 204 opens perpendicularly into the receptacle 201. A clamping screw 206 is screwed into the threaded bore 204, which clamps the cable core 202 of the further cable 203 and electrically connects it to the counter holder 108. In Figure 2 the clamping screw 206 is shown as a screw with a tear-off head in order to limit the tightening torque with which the further cable 203 is clamped. In other exemplary embodiments, however, screws without a tear-off head can also be used, which are tightened with a torque wrench.

The diameter of the receptacle 201 can be varied as desired within the framework of what the material thickness of the cylinder jacket 122 allows, in order to electrically connect further cables of different diameters to the arrangement 100 or the screen 104. The thickness of the cylinder jacket 102 and the diameter of the receptacle 201 are matched to one another in such a way that a mechanically stable screw clamp 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, so many receptacles 201 must not be provided that the mechanical stability of the counter holder 108 is impaired.

Figure 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 bores (not visible) are provided in the area of the recesses 207 so that a cable lug of a further cable can be screwed tight there.

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

The arrangement 100 according to the invention makes it possible to contact the shield of a cable securely by means of simple screw connections and, in addition, to connect further cables to the shield 104 by means of screw connections.

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

By mounting the arrangement 100 on a cable 101, a shield connection is created which is produced in detail as follows. The manufacturing process is shown in a schematic flow diagram in FIG Figure 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 counter holder 108 is pushed onto one end of the cable 101, specifically in the position shown in FIG Figure 1 indicated mounting direction M. Then, in a step S4, the insulating jacket 106 is removed from the cable 101 in order to first expose the screen 104 and then expand it. If it is a smooth screen that is formed from a metal strip, before the screen 104 is expanded, the screen is previously divided into longitudinal strips 127 or the screen is widened conically. This creates a cavity under the umbrella. In a step S5 the clamping sleeve 107 is pushed onto the cable so that the expanded screen 104 comes to rest 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, the clamping sleeve 107 and the counter holder 108 are clamped together in order to establish electrical contact with the screen 104.

The invention has been described in connection with a screen 104 made of metal foil. However, the invention can also be applied to the screens made from wires or from a wire mesh. In these cases, instead of the longitudinal strips 127 of the screen 104, the wires or the wire mesh are placed between the conical outer surface 119 of the clamping sleeve 107 and the conical inner surface 123 of the counter holder 108 and contacted by tensioning the clamping sleeve with the counter holder.

In other exemplary embodiments, the cable core 102 and / or 202 is designed as a stranded wire which, if necessary, is provided with a crimp sleeve. Furthermore, it is not relevant for the present invention from which metal the cable cores 102 and 202 are made. Suitable metals are, for example, copper and aluminum or aluminum alloys.

In principle, it is also possible for the cable core 202 to be electrically connected to the counter holder 108 by welding or soldering. On the other hand, however, screw connections are advantageous in terms of the possibility of being able to connect different materials to one another and occupational safety.

List of reference symbols

100 arrangement 101 (High voltage) cables 201 admission 102 Vein 202 Cable core 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 (counter holder) 109 passage 301 Protection tube 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 jacket 119 conical outer surface 121 structuring 122 Cylinder jacket 123 conical inner surface 126 Area 127 Longitudinal stripes

Claims (11)

1. An arrangement (100) for making contact with an electrical shield (104) of a cable (101), which has an insulated conductor, which is designed as a cable core (102), which is surrounded over its entire length by the shield (104), wherein the arrangement comprises:

   - A first contact element (107), which has a central through-passage (109) for the cable (101) and a conical outer surface (119);

   - a second contact element (108), which has a central through-passage (110) for the cable (101) and a conical inner surface (123) in the opposite direction to the conical outer surface (119), which is adapted to the conical outer surface (119) of the first contact element (107) such that an end region (126) of the shield can be clamped and contacted between the conical outer surface (119) and the conical inner surface (123);

   - clamping means (111, 112, 123), in order to clamp the first and the second contact element (107, 108) with one another,

   and wherein
   a receptacle (201, 207) is provided in the first and/or second contact element (108) for at least one further cable (203), wherein the receptacle (201, 207) is configured in order to establish an electrically conductive connection to the further cable (203) and
   characterized in that
   the outer surface (119) of the first contact element (107) tapers conically in a mounting direction (M), wherein the mounting direction (M) extends along a cable longitudinal direction (A) in the direction from the cable end to the cable (101).
2. The arrangement according to claim 1, characterized in that the arrangement has a protective tube (301).
3. The arrangement according to claim 2, characterized in that the protective tube (301) has a receptacle (302) for a further cable.
4. The arrangement according to claim 3, characterized in that the electrically conductive connection to the further cable (203) is established by means of a screw contact.
5. The arrangement according to claim 4, characterized in that the screw contact comprises a clamping screw (206) with a tear-off head.
6. The arrangement according to any 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).
7. The arrangement according to any one of claims 1-5, characterized in that the receptacle (207) is produced by a flat region on an outer circumferential surface of the first and/or second contact element (107, 108) and/or of the protective tube.
8. The arrangement according to any 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).
9. A shield connection, which comprises an arrangement according to any one of the preceding claims and a cable (101), which has a cable core (102), which is surrounded over its entire length by a shield (104), wherein the shield (104) is accommodated in the arrangement (100) for the contacting.
10. A method for establishing a shield connection according to claim 9, wherein the method comprises:

    - Providing a cable (101), which has a cable core (102), which is surrounded over its entire length by a shield (104);

    - providing an arrangement (100) according to any one of claims 1-8;

    - sliding the second contact element (108) onto the cable (101);

    - creating a cavity under the shield (104) at an end section (126) of the cable (101);

    - sliding the first contact element (107) onto the cable (101), so that the conical outer surface (119) of the first contact element (107) comes to rest in the cavity;

    - pushing the second contact element (108) up to the first contact element (107), so that the shield comes to rest between the conical outer surface (119) of the first contact element (107) and the conical inner surface (123) of the second contact element (108); and

    - clamping the contact elements (107, 108) with one another.
11. The method according to claim 10, wherein, if the cable has a smooth shield (104), before creating the cavity under the shield, the following step is additionally carried out:

    - Cutting the smooth shield (104) into at least two strips (127) or widening the smooth shield.

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