DE102020123696A1 - METHOD OF STRIPPING A CABLE AND DEVICE FOR IT - Google Patents

Abstract

A method for stripping a cable (1), in particular a high-voltage cable, which cable (1) has an outer electrical insulating layer (3) which delimits the cable (1) outward in a radial direction (2) pointing from the inside to the outside, and a shielding film (5) which, viewed in the radial direction (2), is arranged in front of the outer electrical insulating layer (3). According to the invention it is provided that the method comprises the following steps: looping around the cable (1) with at least one cutting wire (9); - tensioning the at least one cutting wire (9) in order to cut into at least the outer electrical insulating layer (3); - generating a relative movement between the at least one tensioned cutting wire (9) and the cable (1) with at least one directional component parallel to an axial direction (14), along which the cable (1) runs at least in sections, around the outer electrical insulating layer (3) and pull off the shielding film (5).

Description

FIELD OF THE INVENTION

The present invention relates to a method for stripping a cable, in particular a high-voltage cable, which cable has an outer electrical insulating layer that limits the cable to the outside in a radial direction pointing from the inside to the outside, as well as a shielding film, which is seen in the radial direction in front of the outer electrical insulating layer is arranged.

The present invention also relates to a device for carrying out the method according to the invention.

STATE OF THE ART

When stripping a cable, in particular a high-voltage cable, the cable having an outer electrical insulating layer which delimits the cable outward in a radial direction pointing from the inside to the outside, as well as a shielding film which is arranged in front of the outer electrical insulating layer when viewed in the radial direction , the outer electrical insulating layer and the shielding film and, if necessary, all layers in between must be removed without damaging a layer immediately in front of the shielding film, viewed in the radial direction.

From the prior art it is known to cut an external electrical insulation of a cable with knives, cf. approximately DE 2426048 A1 . The external electrical insulation is then pulled off or stripped off in the axial direction by means of the knife.

Correspondingly, the outer electrical insulating layer can also be removed automatically in this way. In this case, however, the screen film underneath must be removed by hand in a complex, particularly time-consuming and costly manner.

OBJECT OF THE INVENTION

It is the object of the present invention to create an improved way of stripping the sheath which avoids the disadvantages outlined above.

DISCLOSURE OF THE INVENTION

• - Umschlingen des Kabels mit mindestens einem Schneiddraht;
• - Spannen des mindestens einen Schneiddrahts, um zumindest die äußere elektrische Isolierschicht einzuschneiden;
• - Erzeugen einer Relativbewegung zwischen dem mindestens einen gespannten Schneiddraht und dem Kabel mit zumindest einer

To solve the above-mentioned object, it is in a method for stripping a cable, in particular high-voltage cable, which cable has an outer electrical insulating layer that limits the cable in a radial direction pointing from the inside outwards, as well as a shielding film, which in is arranged in the radial direction in front of the outer electrical insulating layer, the invention provides that the method comprises the following steps:

• - Wrapping the cable with at least one cutting wire;
• Tensioning the at least one cutting wire in order to cut at least the outer electrical insulating layer;
• - Generating a relative movement between the at least one tensioned cutting wire and the cable with at least one

Directional component parallel to an axial direction, along which the cable runs at least in sections, in order to pull off the outer electrical insulating layer and the shielding film.

At least one round wire can be used as the at least one cutting wire.

The at least one cutting wire or several cutting wires can also be stranded or interwoven.

After looping, the at least one cutting wire surrounds the cable completely or over the entire 360 ° around an axis or a vector of the axial direction along which the cable extends at least in sections. Here, a cutting wire or several cutting wires can be wrapped around the cable at least once. If there are several cutting wires, it is also possible that not each of the cutting wires in itself completely surrounds the cable, but that individual cutting wires only extend along part of the circumference of the cable, but all of the cutting wires together completely surround the cable.

The cutting and subsequently the separation or peeling off of the outer electrical insulating layer and the shielding film can thus take place in one process step - without damaging the layers underneath the shielding foil, in particular a braided shield underneath the shielding foil. In the case of further layers between the outer electrical insulating layer and the shielding film, all these additional layers are separated or peeled off with the outer electrical insulating layer and the shielding film - without the layers lying under the shielding film, in particular a braided shield lying under the shielding film, get hurt.

The result is significant time and cost savings.

By using at least one cutting wire or at least one cutting wire rope instead of cutting blades, the cutting forces are distributed more evenly - especially in the case of deviations from the circular cable or conductor cross-section, as can be caused in particular by braids or braided shields in the cable. A type of self-centering between the at least one cutting wire and the cable, which is caused by the tensioning, contributes to this.

The relative movement is preferably linear.

The fact that the directional component of the relative movement is parallel to the axial direction includes a directional component that is anti-parallel to the axial direction. In other words, here and in the following, “parallel” always also includes “anti-parallel”.

The relative movement is preferably completely parallel to the axial direction.

The axial direction and the radial direction are normal to one another, with an infinite number of radial directions existing in a plane normal to the axial direction, which, starting from a center of the cable, point from the inside to the outside or to the outer electrical insulating layer.

The shielding film can in particular be cut by the frictional effect of the cutting wire.

In addition to the relative movement, the at least one cutting wire can also be rotated around the cable. I.e. the axis of rotation is parallel to the axial direction. This tangential movement in a tangential direction, which is normal both to the axial direction and to the radial direction, achieves an additional friction effect of the cutting wire, in particular on the electrical insulating layer or the shielding film. As a result of the additional frictional effect, the above-mentioned frictional effect for cutting can be increased and / or the force to be used, in particular the tensile force to be used for the relative movement for pulling off, can be reduced. Accordingly, in a preferred embodiment of the method according to the invention, it is provided that the relative movement has a directional component parallel to a tangential direction, the tangential direction being normal to the axial direction and to the radial direction.

In a particularly preferred embodiment of the method according to the invention, it is provided that the cutting wire is coiled up and / or unwound in order to generate the directional component parallel to the tangential direction. A structurally particularly simple implementation of the relative movement with a directional component parallel to the tangential direction can be implemented in this way. Typically, at least one reel is used for winding or unwinding, with at least one electric motor preferably being provided for driving the at least one reel.

In order to further reduce the pressure on the cut surface, the at least one cutting wire can be heated. Accordingly, it is provided in a preferred embodiment of the method according to the invention that the at least one cutting wire is heated and / or remains in order to melt and / or embrittle the outer electrical insulating layer during the incision.

Accordingly, the screen foil can also be torn off when the at least one cutting wire is / is heated and the plastic layer over the screen foil is melted or embrittled. This tearing off can take place alternatively or in combination with the above-mentioned cutting of the shielding film by means of friction.

Said plastic layer can also contain a shielding film coating in addition to the outer electrical insulating layer.

The outer electrical insulating layer and / or the shielding foil coating can e.g. be made of PVC or silicone or PETP, PVC or PETP being mainly melted by the heated cutting wire and silicone being mainly embrittled by the heated cutting wire.

The shielding film itself (apart from any coating) typically consists of metal, for example aluminum or an aluminum alloy.

In a particularly preferred embodiment of the method according to the invention, it is provided that the at least one cutting wire is heated by energizing it. On the one hand, the at least one cutting wire is usually electrically conductive with a certain ohmic resistance and can thus be used as a heating wire with little construction / manufacturing effort. On the other hand, it is relatively easy to set an adjustable temperature in a certain range for the entire cutting wire or for the entire section of the cutting wire that wraps around the cable.

In a preferred embodiment of the method according to the invention it is provided that to generate the relative movement, either the at least one cutting wire or the cable is moved. This further reduces the design / manufacturing effort. However, it is of course also possible for both the at least one cutting wire and the cable to be moved in order to generate the relative movement.

To carry out the method according to the invention, a device is provided according to the invention, the device comprising a cable carrier for a cable, in particular high-voltage cable, at least one cutting wire for looping around the cable, tensioning means for tensioning the cutting wire looping around the cable, drive means for generating a relative movement between the cable support and the at least one cutting wire, the device being designed to carry out the method according to the invention.

Suitable drive means as well as tensioning means are known per se and can e.g. at least one electric motor, preferably with a gear, and / or at least one linear drive and / or at least one electric, hydraulic or pneumatic cylinder.

As already mentioned, the relative movement generated is preferably linear.

Analogous to what has been said above, it is provided in a preferred embodiment of the device according to the invention that the drive means comprise at least one coil for winding and / or unwinding the cutting wire. Correspondingly, the direction component parallel to the tangential direction can easily be realized by winding or unwinding the cutting wire from the at least one or onto the at least one coil.

At least one electric motor is typically provided to drive the at least one coil.

Analogous to what has been said above, it is provided in a preferred embodiment of the device according to the invention that at least one heating means is provided for heating the at least one cutting wire. The heating means could for example be formed by a heat source which is brought into contact with the cutting wire, so that the entire cutting wire is heated / heated by conduction.

In a particularly preferred embodiment of the device according to the invention it is provided that the at least one heating means comprises at least one power source with which the at least one cutting wire can be energized. As described above, this enables a temperature in a certain range to be set in a certain range for the entire cutting wire or for the entire section of the cutting wire that wraps around the cable, with the at least one cutting wire usually having a certain ohmic resistance electrically, using inexpensive and structurally / manufacturing-technically simple means is made conductive.

• - mindestens einen elektrisch leitenden Draht, vorzugsweise aus Aluminium;
• - dahinter eine innere elektrische Isolierschicht, vorzugsweise aus Silikon;
• - dahinter ein Schirmgeflecht, vorzugsweise mit Schirmlitzen aus Aluminium;
• - dahinter eine Schirmfolie, vorzugsweise aus Aluminium;
• - dahinter eine elektrisch isolierende Schirmfolienbeschichtung, vorzugsweise aus Kunststoff;
• - dahinter eine äußere elektrische Isolierschicht, vorzugsweise aus Silikon.

Analogous to what has been said above, a system comprising the device according to the invention and the cable is provided according to the invention, the cable comprising the following structure viewed in the radial direction:

• - At least one electrically conductive wire, preferably made of aluminum;
• - behind an inner electrical insulating layer, preferably made of silicone;
• - behind a braided shield, preferably with aluminum braided shields;
• - Behind a screen foil, preferably made of aluminum;
• - behind an electrically insulating shield film coating, preferably made of plastic;
• - Behind it an outer electrical insulating layer, preferably made of silicone.

In the context of the present invention, “aluminum” is to be understood to include not only pure aluminum, but also aluminum alloys.

“Behind” is not necessarily to be understood as “immediately behind” - but of course also includes this case - but leaves open whether one or more other layers, for example made of plastic, come beforehand.

Such a cable structure occurs in particular with high-voltage cables. Accordingly, in a preferred embodiment of the system according to the invention, it is provided that the cable is a high-voltage cable.

Figure list

The invention will now be explained in more detail using an exemplary embodiment. The drawings are exemplary and are intended to explain the concept of the invention, but in no way restrict it or reproduce it conclusively.

• 1 eine schematische Darstellung einer erfindungsgemäßen Vorrichtung bzw. eines erfindungsgemäßen Systems zur Durchführung eines erfindungsgemäßen Verfahrens
• 2 eine weitere schematische Darstellung, in der u.a. Details einer Antriebs- und Spanneinheit erkennbar sind

It shows:

• 1 a schematic representation of a device according to the invention or a system according to the invention for carrying out a method according to the invention
• 2 Another schematic representation in which, among other things, details of a drive and tensioning unit can be seen

WAYS OF CARRYING OUT THE INVENTION

In 1 is a schematic of a system according to the invention comprising a device according to the invention and a cable 1 shown. The cable 1 has an outer electrical insulating layer 3 on that the cable 1 in an inside-out radial direction 2 limited to the outside, as well as a screen foil 5 in the radial direction 2 seen in front of the outer electrical insulating layer 3 is arranged.

In the illustrated embodiment, the cable 1 specifically the following structure, the sequence based on the radial direction 2 is indicated: in the center of the cable 1 there is an electrically conductive wire 8th made of aluminum, behind it an inner electrical insulating layer 7th made of silicone, behind a braided screen 6th with aluminum strands, behind a screen foil 5 made of aluminum, behind it an electrically insulating screen foil coating 4th made of plastic and, finally, an outer electrical insulating layer behind it 3 made of silicone.

The shield strands typically have a diameter of 0.16 mm to 0.31 mm.

In the exemplary embodiment shown, the device comprises a cutting wire 9 with which the cable 1 can be fully surrounded or embraced.

The cutting wire 9 is designed in the illustrated embodiment as a round wire, which typically has a diameter of 0.3 mm to 0.6 mm.

The cable 1 is on a cable carrier 10 clamped in a known manner, the operative connection between the cable carrier 10 and cables 1 in 1 is indicated by the dashed line. In 2 this operative connection is made clear or is the clamping effect of the cable carrier 10 on that between blocks of the cable tray 10 arranged cables 1 immediately visible there.

There is also one, preferably with at least one electric motor 13a (see. 2 ) working, drive and clamping unit 13 provided on the one hand for tensioning the cutting wire 9 serves and on the other hand to generate a relative movement between cables 1 or cable carrier 10 and cutting wire 9 . The operative connection between the cutting wire responsible for tensioning 9 and the drive and clamping unit 13 is in 1 indicated by the dash-dotted line. In 2 are details of the drive and clamping unit 13 and thus the mentioned operative connection recognizable: By means of the electric motor 13a becomes a coil 13b rotated on which the cutting wire 9 while being wound by another spool 13b unwound and so moved and tensioned. By means of a reel brake 13c can be done by braking the coil 13b from which the cutting wire 9 is unwound, the tension of the cutting wire 9 can be specifically increased, for example, to ensure a minimum tension of the cutting wire or to set a certain desired value of the tension.

In the exemplary embodiment shown, the relative movement is a linear movement parallel to an axial direction 14th (is in 1 and 2 each normal to the plane of the drawing) along which the cable 1 runs at least in sections by moving the cutting wire in a corresponding linear manner 9 parallel to the axial direction 14th generated. In the illustrated embodiment, this is for optimal positioning of the cutting wire 9 a cutting wire guide 11 intended. The latter can, for example, have at least sections of plate-shaped elements arranged parallel to one another, between which the cutting wire 9 is arranged so that the cutting wire 9 can only move in a gap or a plane between the plate-shaped elements, cf. 2 .

In addition, the winding and unwinding of the cutting wire 9 relative movement of the cutting wire 9 to the cable 1 or cable carrier 10 with a directional component parallel to a tangential direction 16 (see. 1 ), where the tangential direction 16 normal to the axial direction 14th and to the radial direction 2 is. This results in an additional frictional effect on the cutting wire 9 on the cable 1 to speed up the stripping process.

Furthermore, in the illustrated embodiment, power sources are used 12 provided to the cutting wire 9 by energizing via sliding contacts 15th to be able to heat, cf. 2 .

• - Umschlingen des Kabels 1 mit dem Schneiddraht 9 (1 zeigt den Zustand nach diesem Schritt);
• - Spannen des Schneiddrahts 9 mittels der Antriebs- und Spanneinheit 13, um zumindest die äußere elektrische Isolierschicht 3 einzuschneiden;
• - Bewegen des Schneiddrahts 9 mittels der Antriebs- und Spanneinheit 13 zum Erzeugen der Relativbewegung zwischen dem gespannten Schneiddraht 9 und dem Kabel 1, um die äußere elektrische Isolierschicht 3 sowie die Schirmfolie 5 samt Schirmfolienbeschichtung 4 abzuziehen.

For stripping the cable 1 the following sequence of steps is carried out according to the invention:

• - Wrap around the cable 1 with the cutting wire 9 ( 1 shows the state after this step);
• - Tensioning the cutting wire 9 by means of the drive and clamping unit 13 to at least the outer electrical insulating layer 3 to cut into;
• - moving the cutting wire 9 by means of the drive and clamping unit 13 to generate the relative movement between the tensioned cutting wire 9 and the cable 1 to the outer electrical insulating layer 3 as well as the screen foil 5 including shield film coating 4th deduct.

The cutting wire 9 is preferably set to a specific, adjustable temperature, for example in the range from 180 ° C. to 600 ° C., at least in the area of contact with the electrical insulating layer 3 heated to the electrical insulating layer 3 made of silicone to become brittle when cutting and thus to be able to keep the pressure on the cut surface or the tensioning force required as low as possible. The temperature is typically a function of the specific material of the electrical insulating layer 3 as well as the relative movement, in particular its speed.

List of reference symbols

1

electric wire

2

Radial direction

3

Outer electrical insulation layer

4th

Screen film coating

5

Screen foil

6th

Braided shield

7th

Inner electrical insulating layer

8th

wire

9

Cutting wire

10

Cable carrier

11

Cutting wire guide

12

Power source

13

Drive and tensioning unit for the cutting wire

13a

Electric motor

13b

Kitchen sink

13c

Spool brake

14th

Axial direction

15th

Sliding contact

16

Tangential direction

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 2426048 A1 [0004]

Claims (12)

A method for stripping a cable (1), in particular a high-voltage cable, which cable (1) has an outer electrical insulating layer (3) which delimits the cable (1) outward in a radial direction (2) pointing from the inside to the outside, and a shielding film (5) which, viewed in the radial direction (2), is arranged in front of the outer electrical insulating layer (3), characterized in that the method comprises the following steps: wrapping around the cable (1) with at least one cutting wire (9) ; - Tensioning the at least one cutting wire (9) in order to cut into at least the outer electrical insulating layer (3); - Generating a relative movement between the at least one tensioned cutting wire (9) and the cable (1) with at least one directional component parallel to an axial direction (14), along which the cable (1) runs at least in sections, around the outer electrical insulating layer (3 ) and pull off the shielding film (5). Procedure according to Claim 1 , characterized in that the relative movement has a directional component parallel to a tangential direction (16), the tangential direction (16) being normal to the axial direction (14) and to the radial direction (2). Procedure according to Claim 2 , characterized in that the cutting wire (9) is wound up and / or unwound in order to generate the directional component parallel to the tangential direction (16). Method according to one of the Claims 1 to 3 , characterized in that the at least one cutting wire (9) is heated and / or remains in order to melt and / or embrittle the outer electrical insulating layer (3) during cutting. Procedure according to Claim 4 , characterized in that the at least one cutting wire (9) is heated by energizing it. Method according to one of the Claims 1 to 5 , characterized in that either the at least one cutting wire (9) or the cable (1) is moved to generate the relative movement. Apparatus comprising a cable carrier (10) for a cable (1), in particular high-voltage cable, at least one cutting wire (9) for looping around the cable (1), tensioning means for tensioning the cutting wire (9) looping around the cable (1), drive means for generating a Relative movement between the cable carrier (10) and the at least one cutting wire (9), the device for carrying out a method according to one of the Claims 1 to 6th is designed. Device according to Claim 7 , characterized in that the drive means comprise at least one coil (13b) for winding and / or unwinding the cutting wire (9). Device according to one of the Claims 7 to 8th , characterized in that at least one heating means is provided for heating the at least one cutting wire (9). Device according to Claim 9 , characterized in that the at least one heating means comprises at least one power source (12) with which the at least one cutting wire (9) can be energized. A system comprising the device according to any one of Claims 7 to 10 and the cable (1), the cable (1) comprising the following structure, viewed in the radial direction (2): at least one electrically conductive wire (8), preferably made of aluminum; - Behind an inner electrical insulating layer (7), preferably made of silicone; - Behind a braided shield (6), preferably with aluminum braided shields; - Behind a screen foil (5), preferably made of aluminum; - behind an electrically insulating shield film coating (4), preferably made of plastic; - Behind an external electrical insulating layer (3), preferably made of silicone. System according to Claim 11 , characterized in that the cable (1) is a high-voltage cable.

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