CH701871A1 - Electro-optical cable. - Google Patents

Abstract

An electro-optical cable (1) for data transmission and / or energy transmission, comprising a central loose tube (10), wherein in the central loose tube at least one optical waveguide (12a, 12b, 12c, 12d) is arranged and wherein the central loose tube (10) of at least a first tubular and electrically conductive braid (20) is surrounded in a coaxial arrangement, characterized in that the at least one optical waveguide (12a, 12b, 12c, 12d) loosely present in the central bundle core (10), wherein the central loose tube (10) has an outer diameter of at most 4 mm.

Description

Technical area

The invention relates to an electro-optical cable for data transmission and / or energy transfer, comprising a central loose tube, wherein in the central loose tube at least one optical waveguide is arranged and wherein the central loose tube surrounded by at least a first tubular and electrically conductive mesh in a coaxial arrangement is. Further, the invention relates to a use of an electro-optical cable.

State of the art

Electro-optical cables include at least one optical waveguide one or more electrical conductors. About the at least one optical waveguide can be z. B. in wired communication and control systems data and / or control signals transmitted optically. At the same time can be done via the electrical conductors, a power supply or electrical signals are transmitted independently of the optical signals. Since different transmission media are to be combined in a single cable, electro-optical communication and power cables are also referred to as hybrid cables.

WO 2007/006 167 A1 (Brugg Kabel AG) discloses, for example, an electro-optical communication and power cable, which in a central loose tube made of a smooth, flexible metal tube, at least one optical waveguide with a primary sheath, two coaxial layers extending to the buffer tube made of stranded metal wires, which also serve as a tensile and shear force relief, and an outer sheath comprises. In addition, the metal tube surrounding a loosely arranged fiber optic cores, z. As a gel, are present. If the metal tube is made of a highly conductive material, the metal wires of the inner layer can at most be omitted.

From US 5 557 698 (Beiden Wire & Cable Company) is known a cable with a fiber optic core which is surrounded by two coaxial electrical conductors. The cable is particularly suitable as a connection cable for video cameras or for fiber-based computer networks. Due to the combination of energy and data transmission in one cable, the weight and space requirements can be minimized, which is particularly advantageous in the areas of aircraft, military and aerospace. The fiber optic core consists z. Example, of a plurality of optical fibers, which in a common dielectric sheath, z. B. a polymeric material. In addition, in the sheath is a strain relief, z. As in the form of aramid yarn with glass fiber epoxy rods, as protection for the optical fibers. The optical core is surrounded by an inner and an outer braided electrical conductor. The braided ladder consist z. B. from a copper braid and by a dielectric, z. B. of a polymeric material such as PE, PP, PTFE, kept at a distance. The outer electrical conductor is also surrounded by a strain relief and an outer sheath. Preferably, the outer sheath and the sheath of the fiber optic core also contain a pull line.

The currently known electro-optical cable assets in practice, especially under harsh conditions in the military environment or in oil production, not completely satisfactory. Often, the known cables are prone to mechanical effects, or not sufficiently robust, the flexibility of the cable is severely limited or the cables have a very voluminous structure.

There is therefore still a need for an electro-optical cable, which does not have the disadvantages mentioned above.

Presentation of the invention

The object of the invention is to provide an electro-optical cable belonging to the aforementioned technical field for data transmission and / or energy transmission, which compared to known cables is more compact, robust and / or flexible and in particular has an optimized minimum bending radius.

The solution of the problem is defined by the features of claim 1. According to the invention, the at least one optical waveguide is loosely present in the central loose tube, the central loose tube having an outer diameter of at most 4 mm.

Under a mesh is understood in the present context, in particular an arrangement of several regularly interlaced strands or bundles of a flexible and electrically conductive material. The individual strands are in particular skewed, d. H. at an angle greater than 0 ° and less than 90 ° to each other, and may for example consist of one or more individual elements, e.g. Metal wires, insist.

The braid is in particular tubular, wherein a longitudinal central axis of the braid is coaxial with a longitudinal central axis of the central loose tube or the tubular braid. Thus, the central loose tube is evenly surrounded by the mesh. Advantageously, the first braid lies directly on the plastic tube of the central loose tube.

The at least one optical waveguide may e.g. in the form of a glass fiber made of a mineral glass or of a light-conducting plastic. Preference is given to bending-optimized glass fibers are used, the glass fibers also advantageously have a primary sheath made of plastic. An outer diameter of the glass fiber with the primary cladding measures, for example, 125 μm to 250 μm. However, in principle, other light-conducting elements can also be used as optical waveguides. Depending on the application, optical fibers with single-mode fibers or multimode fibers are used. However, it is also possible to use other glass fibers which are e.g. are not specifically bend optimized.

As has been shown, the combination of a central loose tube with a loosely arranged optical fiber and an outer diameter of at most 4 mm and a coaxially arranged around electrically conductive mesh allows a particularly compact and robust design. Particularly preferably, the central loose tube has a diameter of at most 2.5 mm and more preferably of at most 2.0 mm. Due to the loose arrangement of the at least one optical waveguide, this is mounted freely movable at least in the radial direction in the central loose tube. As a result, the at least one optical waveguide can move relative to it during a deformation of the central loose tube caused by an acting force, or assume a new relative position to the central loose tube. The force acting on the central buffer tube during the deformation during the deformation is thus not necessarily transmitted to the at least one optical waveguide. This is not the case with a fixed arrangement of the optical waveguides in the central loose tube. The central buffer tube therefore preferably does not contain any additional elements, e.g. tensile elements. In other words, the central loose tube advantageously only contains one or more optical waveguides. As a result, a sufficient relative movement of the at least one optical waveguide can be ensured.

The inventive cable have even with low cable diameter over unexpectedly high tensile, transverse pressure and impact resistance. Due to the tubular mesh, the sensitive central loose tube is also against punctual effects, such. Rodent bites or sharp-edged areas, well protected. At the same time, the cables according to the invention have a high bending flexibility and an extremely low minimum bending radius. The cables according to the invention have also proven suitable for repeated winding and unwinding and are therefore easy to reel, which is especially advantageous for mobile use.

The inventive structure also ensures a good assembly of the cable, since both the optical waveguide and the electrically conductive mesh are easily accessible and connectable to connectors.

Due to the high mechanical strength, the inventive cable can also be easily clamped with clamping wedges, without causing the risk of damage.

Preferably, the at least one optical waveguide is embedded in the central loose tube in a fluid vein filler. Preferably, the at least one optical waveguide is thus present loosely in the central loose tube filled with a fluid vein filler compound. Thus, the at least one optical waveguide in the fluid vein filler mass is mounted freely movably in the central buffered vein, at least in the radial direction. The fluid vein filler is preferably a gelatinous mass or a finely divided system of at least one solid and one liquid phase.

The fluid vein filler damps in combination with the central loose tube in particular short-term sudden effects on the inventive cable from effective, which optimally protects the at least one and sensitive optical fibers.

Advantageously, the central loose tube is completely filled with fluid vein filler. Apart from the at least one optical waveguide and the fluid core filling compound, there are advantageously no further elements in the central loose tube. In other words, the central buffer tube thus preferably contains exclusively at least one optical waveguide and the fluid core filling compound. Depending on the application and the requirements of the cable according to the invention, however, a fluid wire-filling compound can basically be dispensed with.

The central loose tube is preferably made of a plastic tube. Especially in combination with a fluid wire filling compound, short-term, sudden effects on the cable according to the invention can thereby be damped even more effectively, and at the same time a high flexibility of the cable is achieved. In a particularly preferred embodiment, the central loose tube is made of a plastic tube and preferably contains only the at least one optical waveguide and the fluid vein filler. This allows the cable to be further optimized in terms of flexibility and robustness.

For special applications, it may also be advantageous to use a loose tube made of a metal tube, for. As a steel pipe to provide and / or to manufacture the central loose tube of other materials than plastic or metal.

As has been shown, a ratio between an outer diameter of the first braid and an outer diameter of the plastic tube is advantageously in the range of 1.2-1.6, preferably 1.35 -1.45. Thus, the bending elasticity and mechanical strength of the inventive cable can be further optimized in a compact design.

In principle, however, other conditions between the outer diameters of the plastic pipe and the first braid are possible, if this z. B. is desirable for certain applications.

A ratio of an outer diameter of the central loose tube to an inner diameter of the central loose tube is advantageously at about 1.3 - 2.2, more preferably at about 1.6-1.7. More preferably, the central loose tube has an outer diameter of 1.3-1.7 mm and / or an inner diameter of 0.8-1.0 mm, the central loose tube preferably has a wall thickness of 0.2-0.4 mm. Preferably, the central loose tube consists of a plastic tube, in particular of polyamide, polypropylene, polybutylene terephthalate and / or polyethylene. Such trained central loose tubes are unusually small compared to known loose tubes. Surprisingly, it has been found that such dimensioned central loose tubes in combination with the first metal braid are particularly advantageous, since both an improved bending elasticity and an improved protective effect for the at least one optical waveguide of the central loose tube is achieved without additional reinforcing elements in the central loose tube should be provided. This applies in particular to central loose tubes made of a plastic tube and / or central loose tubes with a fluid vein filler.

In principle, however, differently sized central loose tubes can be used, which z. B. have a smaller outer diameter than 1.3 mm or a larger outer diameter than 1.7 mm. Also, it is not mandatory to comply with the above-mentioned relationships between outside and inside diameters.

In a further advantageous embodiment of the invention, a total of four optical fibers are arranged in the central buffer tube, which advantageously have an outer diameter of about 250 microns. In particular, in combination with a central loose tube made of a plastic tube and an outer diameter of 1.3- 1.7 mm and / or an inner diameter of 0.8-1.0 mm or a plastic tube with a wall thickness of 0.2 - 0.4 mm is in four fiber optic cables in the central loose tube available Standing space is used particularly effectively, while the optical fibers are still optimally protected against mechanical effects. Due to the individually usable optical waveguide, the cable according to the invention in this embodiment also offers a high degree of flexibility with regard to the possible applications.

However, it is in principle possible to provide more than four and in particular up to eight optical waveguides in the central loose tube.

It has also proved to be advantageous if the at least one optical waveguide has an excess length with respect to the central loose tube. Preferably, the excess length is in the range of 0.05-0.2%. The excess length refers in particular to a length of the central loose tube at room temperature, i. about 20 ° C. Such overlengths have proven to be suitable in particular in combination with central loose tubes made of plastic pipes with an outer diameter of 1.3-1.7 mm and / or an inner diameter of 0.8-1.0 mm or a wall thickness of 0.2-0.4 mm. The excess length of the at least one optical waveguide makes it possible to compensate for the different coefficients of thermal expansion of at least one glass fiber and of the central loose tube, in particular in the case of central loose plastic tubes. The inventive cable thus remains fully functional even at high temperature fluctuations and takes no damage. The inventive cable can be used at temperatures of -55 ° C up to + 85 ° C. A storage of the inventive cable is possible even in a temperature range of -70 ° C to + 85 ° C.

In principle, a smaller or a larger excess length of the optical waveguide can be provided. However, if the excess lengths are too small, the range of application of the cables according to the invention may be reduced. If too much excess length, strong bends of the at least one optical waveguide can also result in a cable running in a straight line, so that the optical waveguides are pressed from the inside to the central loose tube. This in turn can cause high attenuation in light transmission, which is of course undesirable.

The first electrically conductive braid is preferably made of metal wires, in particular of copper wires, which particularly preferably have a diameter of 0.05 - 0.2 mm. In other words, the first metal mesh is advantageously present as wire mesh or copper braid. In a further preferred embodiment, the copper wires are tinned copper wires. Braids of metal wires, and in particular copper wires, have proven to be particularly useful, since they both have good electrical conductivity, and also have particularly advantageous properties in terms of mechanical strength and flexibility. This applies in particular to metal wires with a diameter of 0.05-0.2 mm, whereby in the present context metal wires with a diameter of 0.13 - 0.17 mm have been found to be optimal.

In principle, however, the first braid can also consist of another conductive material. Thus, it is basically conceivable to use a mesh of conductive fibers, e.g. Carbon fibers to provide. Carbon fibers are characterized in particular by a high mechanical stability as well as a good electrical conductivity.

It is also conceivable to manufacture the first mesh of different materials, wherein electrically conductive materials can be combined with electrically non-conductive materials. For example, it is conceivable, the first braid of metal wires, in particular copper wires, and high-strength synthetic fibers, for. B. aramid fibers to manufacture. It is also possible to deviate from the specified wire diameters, which, however, may be at the expense of conductivity, flexibility and / or mechanical strength.

Particularly preferably, the first electrically conductive mesh consists of 8-36 braided bundles of 1-12 metal wires. Plaits made of 15-17 bundles with 2-4 wires each have proven to be particularly suitable. An outer diameter of the first mesh preferably measures approximately 2.0-2.2 mm. Such a structure of the braid in combination with the central bundle core according to the invention allows a particularly compact design and brings advantages in particular with regard to the bending flexibility and mechanical strength of the cable according to the invention. Preferably, the electrical resistance of the first mesh is 15-40 Ω / km, more preferably 20-28 Ω / km. This ensures good electrical conductivity in combination with sufficient mechanical strength of the first braid.

In principle, however, it is also possible to provide a differently designed braid, which consists for example of less than 8 bundles or more than 36 bundles. The number of metal wires per bundle can in principle be greater than 12 and the electrical resistance can be less than 15 Ω / km or greater than 40 Ω / km. However, under certain circumstances this eliminates the aforementioned advantages.

Advantageously, the first electrically conductive braid with respect to a longitudinal center axis of the braid or the central loose tube a braid angle of 45 - 80 °, preferably 60-75 °, on. In other words, the braid angle denotes the deviation of the wire path in the tubular braid from the longitudinal central axis of the braid or the longitudinal central axis of the central bundle core. As has been shown, the braid angle plays a decisive role in the specified range with regard to an optimal flexural flexibility and mechanical strength of the cable according to the invention.

In principle, however, larger or smaller braid angles can be provided. However, the above-mentioned advantages in such a choice of the braid angle may be omitted.

Advantageously, the first electrically conductive mesh has an area coverage of 80-99%, preferably 85-95%. The area coverage is defined in particular as the area fraction which is covered in a projection of the tubular braid on the enveloping lateral surface of the tubular braid. Since the area coverage is advantageously at most 99%, the mesh has gaps. These intermediate spaces increase bending flexibility, in particular in the event of bending of the cable according to the invention, since additional free space exists, in particular in compressed areas. It has proved particularly expedient to have an area coverage of 85-95%. In such area coverings on the one hand a high bending flexibility is achieved, on the other hand results in a high mechanical strength against tensile, transverse pressure and impact loads. This in particular in conjunction with a central loose tube, in particular a plastic tube, with an outer diameter of 1.3-1.7 mm and / or an inner diameter of 0.8 - 1.0 mm or a wall thickness of 0.2 - 0.4 mm.

Depending on the intended use of the cable according to the invention, it may however also be advantageous to provide smaller surface coverages than 80% or larger surface coverages than 99%. However, the possible uses of the cable according to the invention are generally limited.

In a particularly advantageous embodiment, the first electrically conductive mesh is surrounded by a coaxially arranged second tubular and electrically conductive mesh. The first electrically conductive braid is in particular electrically insulated from the second electrically conductive braid. By a second electrically conductive mesh, the possible applications of the inventive cable can be further increased because two independent electrical conductors are available. An electrical insulation of the first and the second electrically conductive braid, as explained in detail below, z. B. via an insulating layer, which is arranged between the two braids.

The first electrical braid may e.g. be provided as a phase conductor, while the second electrically conductive mesh acts as a neutral conductor or ground conductor. This has the advantage that damage to the outer areas of the cable, even at high voltages or currents, there is no immediate danger to persons who come into contact with the damaged areas. Prefabricated cables therefore preferably have reverse polarity protected connectors at the cable ends. Particularly preferably, the cable ends are equipped with hermaphroditic connectors. This ensures that the cable is not accidentally connected incorrectly.

It is understood that in addition to the two electrically conductive braids further electrical conductors, in particular further braids and / or electrical conductive wires, can be provided. In principle, it is also conceivable to dispense with the second electrically conductive mesh and instead provide a layer of stranded electrically conductive wires. But it can also be completely dispensed with the second braid.

The second electrically conductive braid is advantageously made of metal wires, in particular copper wires, which particularly preferably have a diameter of 0.05-0.2 mm. Particularly preferably, the first electrically conductive braid and the second electrically conductive braid consist of substantially identical metal wires. In other words, the first electrically conductive braid and the second electrically conductive braid advantageously consist of metal wires, which consist of the same material, in particular copper, and have the same cross-sectional areas and the same diameter. Such a configuration of the second braid allows both a particularly compact design and a high bending flexibility and mechanical strength of the inventive cable.

In principle, however, the second braid can also be designed differently, with conceivable embodiments have already been mentioned above in connection with the first braid. The variants described there are also conceivable in the second braid. It is also possible to form the first braid and the second braid differently.

Like the first electrically conductive braid, the second electrically conductive braid consists in particular of 8-36 braided bundles of 1-12 metal wires each. Braids made of 15-17 bundles with 2 to 4 wires each have proven to be particularly suitable. Particularly suitable are a number of the braided bundles of the first electrically conductive braid and a number of the braided bundles of the second electrically conductive braid same. Further, more preferably, a number of the metal wires of the braided bundles of the first electrically conductive metal braid are equal to a number of the metal wires of the braided bundles of the second electrically conductive metal braid. An outer diameter of the second mesh preferably measures between 3.2 - 3.4 mm. By such a configuration of the second braid, an even more compact design can be realized and the flexural flexibility and the mechanical strength can be further increased.

However, it is possible to form the first braid and the second braid differently and provide the second braid less than 8 or more than 36 bundles. In principle, the number of metal wires per bundle can also be greater than 12, if this is expedient. However, it may be necessary to omit the advantages mentioned above.

Advantageously, also has the second electrically conductive mesh with respect to a longitudinal central axis of the braid or the central loose tube over a braid angle of 45-80 °, preferably 60-75 °. Particularly advantageously, the first electrically conductive braid and the second electrically conductive braid essentially have an identical braid angle. In conjunction with the structure of the first braid and the central bundle core according to the invention, in particular the bending flexibility and mechanical strength of the cables according to the invention can be further improved.

In principle, the braid angle of the second braid can also be smaller than 45 ° or greater than 80 °. It is also possible to provide a different braid angle to the first braid in the second braid, if, for example, this is suitable for specific uses.

An area coverage of the second electrically conductive mesh is advantageously less than the area coverage of the first electrically conductive mesh. Particularly preferably, the area coverage of the first electrically conductive braid is greater by a factor of 1.3-1.5 than the area coverage of the second electrically conductive braid. As has been shown, the flexural flexibility and the mechanical strength of the cable according to the invention can thereby be improved overall with the lowest possible cable weight.

In principle, however, the surface coverages of the first electrically conductive braid and of the second electrically conductive braid may also be the same. It is also possible in principle to choose the area coverage of the second electrically conductive mesh greater than the area coverage of the first electrically conductive mesh. However, this has proved less practical.

Specifically, the area coverage of the second electrically conductive braid is advantageously 50-90%, preferably 60-70%.

However, in principle, even smaller area coverages than 50% or larger surface coverages than 90% are possible with the second braid. This may even be appropriate in a particular case.

Preferably, the electrical resistance of the second braid is 15-40 Ω / km, more preferably 20-28 Ω / km. Advantageously, a first electrical resistance of the first electrically conductive braid is substantially the same as a second electrical resistance of the second electrically conductive braid. This can be z. B. realize by a smaller area coverage of the second braid against the first braid. Overall, this simplifies the power line, since there are the same conditions regardless of the electrically conductive mesh.

But it is also possible to form the second braid with a different from the first braid electrical resistance. It is also possible to provide a second braid with an electrical resistance of less than 15 Ω / km or more than 40 Ω / km.

A ratio of an outer diameter of the second braid to an outer diameter of the first braid is advantageously in the range of 1.3-1.8, in particular in the range of 1.5-1.65. As a result, the flexural flexibility and the mechanical strength of the cable according to the invention can be further optimized.

But it is also possible to deviate from the specified ratio of the outer diameter of the two braids. This can be z. B. necessary for special applications.

More preferably, an insulating layer for electrical insulation is disposed between the first electrically conductive braid and the second electrically conductive braid. If additional electrically conductive braids are arranged, insulation layers are advantageously present between all the braids. In the present context, an insulating layer is to be understood as meaning, in particular, a layer of a material having a specific electrical resistance of more than 10 × 10 Ωm. Due to the insulating layer can be achieved in a simple manner an effective electrical insulation between the two electrically conductive braids. Due to the interaction of the insulating layer and the two braids, it is possible to use the inventive cable for currents of up to 15 A at AC voltages of up to 1000 V or DC voltage of up to 1500 V.

However, it is also conceivable to use the electrically conductive elements, e.g. Metal wires, at least one braid instead of or in addition to the insulating layer to be provided with an electrically insulating coating. As a result, an electrical insulation can also be achieved.

Preferably, the insulating layer of a plastic, preferably of thermoplastic materials, polyamide, ethylene-propylene rubber (EPR), polyethylene, and / or polyurethane. In particular, it may also be advantageous to provide a flame-retardant and non-corrosive plastic ("flame retardant non-corrosive", FRNC) as the insulating layer. The insulation layer further preferably has a thickness of 0.25-0.50 mm in a radial direction. It has been found that such insulating layers are particularly advantageous. In addition to an effective electrical insulation, these insulation layers in combination with the two electrically conductive braids also improve the mechanical strength of the cable according to the invention, without thereby impairing the bending flexibility.

Particularly preferably, the insulating layer is extruded onto the first mesh. This creates, in particular, a mechanically relatively stable bond between the first braid and the insulating layer. This is particularly true in the case of an insulating layer of polyamide, ethylene-propylene rubber (EPR), polyethylene, and / or polyurethane.

The second braid is preferably directly on the insulating layer. This has proven to be particularly advantageous in terms of a compact design.

In principle, however, the insulating layer can also be made of other materials. In question come z. B. non-conductive fiber materials. It is also possible to deviate from the stated thicknesses, but at lower thicknesses it must be ensured that there is sufficient electrical insulation. Greater thicknesses are particularly disadvantageous in terms of bending flexibility and a compact design.

In a further advantageous variant, a strain relief layer is also present in the cable according to the invention. The Zugentlastungslage consists in particular of synthetic fibers, which is particularly preferably aramid fibers.

Advantageously, the first and / or the second and / or an outermost electrically conductive mesh are surrounded by the strain relief layer. Thus, the strain relief layer is preferably outside the central loose tube and more preferably outside of the first electrically conductive braid and possibly existing further electrically conductive braids before.

If the cable according to the invention has exactly two electrically conductive braids, the second electrically conductive braid is advantageously surrounded by the strain relief layer, wherein the strain relief layer advantageously rests directly on the second electrically conductive braid.

Such a configuration and arrangement of the strain relief layer has proven to be particularly suitable. On the one hand, this maintains a high flexural flexibility of the cable according to the invention, on the other hand, the mechanical strength can be improved significantly with nevertheless extremely compact construction.

In principle, however, can be dispensed with a strain relief or it can be provided a differently designed strain relief, which limits the uses of the inventive cable. Instead of synthetic fibers, the strain relief elements may e.g. also in the form of solid wires made of high-strength metal or plastic. Furthermore, it is also conceivable to provide strain relief layers of synthetic fibers with further strain relief elements, e.g. made of metal, reinforce. At most, however, this reduces bending flexibility.

Further, the inventive cable preferably has an outer sheath, wherein the outer sheath, depending on the application in particular of a polyamide, ethylene-propylene rubber (EPR), polyethylene, polyurethane and / or thermoplastic elastomers. The outer sheath protects the inner areas of the cable against mechanical influences and the ingress of moisture or moisture. Polyamide has proved to be particularly useful, since this has a high abrasion resistance and at the same time a high flexibility. As a result, the cable according to the invention is optimally suitable for mobile use, with the cable frequently being unwound and unrolled. Advantageously, the outer jacket is also UV resistant. For this it is e.g. also possible to integrate soot particles in the outer jacket.

For special applications but can be dispensed with an outer sheath or the outer sheath can be made of a different material than polyamide.

A particularly preferred embodiment of the cable according to the invention has in addition to the inventive central loose tube on a first lying metallically conductive braid, an extruded on the first metallic braid insulation layer, applied to the insulating layer second metallically conductive braid, one on the second metallic braid resting strain relief and an applied on the strain relief layer outer sheath.

Such cables according to the invention are particularly compact, robust, readily bendable and at the same time flexibly usable. Furthermore, these cables are also characterized by a low weight of only 20-40 g / m and can be formed completely halogen-free with appropriate choice of materials.

The inventive cable can be used for a wide variety of applications. For example, as transmission lines under water, especially in open waters and sewers of settlements, commercial and industrial, and in the ground, especially along roads or rails, in piping and cable ducts or buildings. Likewise, the cable according to the invention can be laid as an overhead line. In particular, the inventive cable can be used under harsh conditions in the military environment or in oil production.

Due to the great robustness in combination with the high flexibility and a small minimum bending radius, the cables according to the invention are especially suitable for mobile use.

The inventive cable is z. B. suitable for the remote supply of a mobile electrical device and / or a mobile electrical power supply network. For this purpose, the cable can be used for example as a connecting line in an arrangement with two voltage transformers, which is in particular a hard-wired and a variable voltage converter.

The arrangement comprises, for example, a first voltage converter, e.g. a transformer, and a second voltage converter, for example, also a transformer, wherein the two voltage transformers are electrically conductively connected via a cable according to the invention. With the first voltage converter, for example, the electrical energy to be transmitted via the cable according to the invention is transformed in such a way that the highest possible voltage and low current result, which enables a loss-minimized transmission of the electrical energy. With the second voltage converter, a corresponding inverse transformation to lower voltages and higher currents can take place, as e.g. are suitable for operating a consumer and / or a mobile electrical power supply network.

From the following detailed description and the totality of the claims, there are further advantageous embodiments and feature combinations of the invention.

Brief description of the drawings

The drawings used to explain the embodiment show: <Tb> FIG. 1 <sep> A side view of an electro-optical cable according to the invention comprising a central loose tube with four optical waveguides, two electrically conductive braids spaced apart by an insulating layer and a strain relief layer arranged around it and an outer jacket, wherein the individual cable elements are exposed in layers; <Tb> FIG. 2 <sep> A cross-section through the cable of Fig. 1 along the line A-A; <Tb> FIG. 3 <sep> An arrangement with two connected via a cable of FIGS. 1 and 2 transformers for the remote supply of a mobile electrical network.

Basically, the same parts are provided with the same reference numerals in the figures.

Ways to carry out the invention

In Fig. 1, an inventive electro-optical cable 1 is shown in a schematic side view along its longitudinal central axis 14 in the region of the cable end. The individual cable elements are exposed in layers in the longitudinal direction to illustrate the cable structure. FIG. 2 accordingly shows a schematic cross section through the electro-optical cable 1 which is circular in cross-section along the line A-A in FIG. 1.

The electro-optical cable 1 has a central loose tube 10 made of a plastic raw r 11 with, for example, four arranged therein optical fibers 12a, 12b, 12c, 12d. All four optical waveguides 12a, 12b, 12c, 12d consist for example of bending-optimized glass fibers and are each surrounded by a primary cladding 13a, 13b, 13c, 13d. Depending on the application, optical fibers with single-mode fibers or multimode fibers are used. An outer diameter of each of the four optical waveguides 12a, 12b, 12c, 12d including the primary cladding 13a, 13b, 13c, 13d is z. B. 250 microns. The four optical waveguides 12a, 12b, 12c, 12d with their primary cladding 13a, 13b, 13c, 13d have in a longitudinal direction of the electro-optical cable 1 or in a direction parallel to the longitudinal central axis 14 of the electro-optical cable 1 at a temperature of about 20 ° C. Overlength compared to the plastic tube 11, for example, about 0.1%.

The plastic tube 11 of the central buffer tube 10 consists e.g. of polyamide, polypropylene, polybutylene terephthalate and / or polyethylene and has an inner diameter 11.1 of z. B. 0.8 - 1.0 mm and an outer diameter of 11.2, for example, 1.3-1.7 mm. A wall thickness 11.3 of the plastic pipe 11 measures approximately 0.2-0.4 mm. The plastic pipe 11 is completely filled with a fluid wire filling compound 15 in the form of a gel. The four optical waveguides 12a, 12b, 12c, 12d with their primary sheaths 13a, 13b, 13c, 13d are embedded in the radial cored mass 15 in the radial direction and, to a limited extent, also in the longitudinal direction.

The central loose tube 10 or the plastic tube 11 is surrounded by a first electrically conductive braid 20. The first braid 20 is tubular and lies directly on the lateral surface of the plastic tube 11. A longitudinal center axis of the first braid 20 is aligned coaxially to the longitudinal central axis 14 of the electro-optical cable. The first braid 20 consists, for example, of sixteen interwoven bundles and has an outer diameter 20.1 of approximately 2.0-2.2 mm. A bundle 21 is z. B. of three metal wires 22a, 22b, 22c, which is in particular tinned copper wires with a diameter of 0.13 to 0.17 mm. All sixteen bundles of the first braid 20 are substantially identical. A braid angle 23.1, which is measured as an angle between the longitudinal center axis 14 of the electro-optical cable 1 and a tangential direction 23 of the wire path of the metal wires 22a, 22b, 22c, is z. B. about 60 - 75 °. The area coverage of the first mesh is about 90%. The electrical resistance of the first braid 20 is z. B. about 22 Ω per 1 km cable length.

The first braid 20 is surrounded directly by an extruded insulating layer 30 made of polyamide, wherein a thickness 30.1 of the insulating layer 30, measured in the radial direction of the electro-optical cable 1, for example, about 0.25 - 0.50 mm.

The insulating layer 30 is surrounded by a second electrically conductive braid 40. Like the first braid 20, the second braid 30 is tubular and lies directly on the lateral surface of the insulating layer 30. A longitudinal central axis of the second braid 30 is also aligned coaxially with the longitudinal central axis 14 of the electro-optical cable. The second mesh 30, like the first mesh, for example, consists of sixteen interwoven bundles. An outer diameter 40.1 of the second braid 40 measures approximately 3.2-3.4 mm. A bundle 41 of the second braid is substantially identical to the bundle 21 of the first braid and accordingly has three metal wires 42a, 42b, 42c, which are in the form of tinned copper wires with a diameter of 0.13-0.17 mm. The metal wires of the first braid 20 and the second braid 40 are substantially identical. All sixteen bundles of the second braid 40 are substantially identical. A braid angle 43.1, which is measured as an angle between the longitudinal center axis 14 of the electro-optical cable 1 and a tangential direction 43 of the wire path of the metal wires 42a, 42b, 42c, is z. However, the area coverage of the second braid 40 at about 66%, however, is less than the area coverage of the first braid 20. The electrical resistance of the second Braid 40 is about 22 Ω per 1 km of cable length as in the first braid 20.

Around the second braid 40, a strain relief layer 50 is disposed. This preferably consists of a yarn of aramid fibers, in particular with a yarn count of 800-4000 dtex. The strain relief layer 50 includes longitudinal threads, which run parallel to the longitudinal central axis 14 of the electro-optical cable 1, as well as stranded threads, which rotate around the longitudinal central axis 14 helically.

An outer jacket 60 is applied around the strain relief layer 50. The outer jacket 60 is depending on the application z. Example of polyamide, ethylene-propylene rubber (EPR), polyethylene, polyurethane and / or thermoplastic elastomers, wherein optionally be added to improve the UV resistance soot particles. The outer diameter of the outer jacket 60 and the electro-optical cable 1 is about 4-6 mm. The plastic used for the outer jacket 60 is preferably softer than the plastic used for the insulating layer 30 and / or the plastic pipe 11.

Fig. 3 shows schematically an arrangement 100 for the remote supply of a mobile electrical power supply network. In this case, the arrangement 100 comprises a first voltage converter in the form of a first transformer 110 and a second voltage converter in the form of a second transformer 120, which are electrically connected to one another via the electro-optical cable 1 from FIGS. 1 and 2. The electro-optical cable 1 has its first end via a hermaphroditic connector 90a, which is electrically connected to a complementary socket 111 of the first transformer 110.

Likewise, the second end of the electro-optical cable 1 is equipped with a second hermaphroditic connector 90b, which is correspondingly electrically connected to a complementary socket 121 of the second transformer 120.

Via a first mains connection 115, the first transformer 110 is connected e.g. with a power supply network (not shown in Fig. 3), which z. B. at a voltage of 110 V or 230 V is connected. Via the first transformer 110, the fed-in voltage is transformed to a transmission voltage of up to 1000 V AC or 1500 V DC. Thereby can be transmitted via the electro-optical cable 1 electrical energy with minimal loss of conduction. About the second transformer 120, which z. B. is designed as a controllable transformer, the transmission voltage to the operating voltages required in the mobile electrical power grid, e.g. 110 V or 230 V, and are fed via a second network connection 125 in the mobile electrical power grid (not shown in Fig. 3).

In the arrangement 100, the first braid 20 of the electro-optical cable 1 functions as a phase conductor, while the second braid 40 is used as a neutral conductor. This minimizes the risk of danger to persons if the outer cable areas are damaged. The hermaphroditic connectors 90a, 90b effectively prevent inadvertent reverse polarity of the two braids 20, 40.

In parallel to the electrical energy, for example, data can be transmitted via the optical waveguides 12a, 12b, 12c, 12d arranged in the central loose tube 10.

The arrangement 100 is z. B. for military tactical use extremely advantageous because the electro-optical cable due to its flexural flexibility, the mechanical strength and robustness can also be installed directly on the earth's surface or as an overhead line.

Test experiments with the inventive cable 1 have shown that this has a very low minimum bending radius of 30 mm and withstand a radius of 50 mm up to 4000 alternating bends unscathed. The transverse pressure resistance is up to 400 N / cm, while a tensile strength of up to 1500 N is achieved.

The above embodiments are to be understood as illustrative examples only, which may be modified as desired within the scope of the invention.

Thus, e.g. possible to accommodate in the central buffer tube 10 less or more than four optical fibers 12a, 12b, 12c, 12d. Likewise, it is conceivable to design the four optical waveguides 12a, 12b, 12c, 12d differently. If this is expedient, the optical waveguide z. B. have different thicknesses. Likewise, instead of or in addition to the primary sheaths 13a, 13b, 13c, 13d, additional sheaths may be present.

Instead of a plastic tube 11 may also be a metal tube, for. B. stainless steel, are used for the central loose tube 10. It is also possible to dispense with the fluid wire filling compound 15.

In principle, it is also conceivable to provide an intermediate layer between the plastic tube 11 and the first braid 20, if this is considered expedient. If necessary, e.g. In order to increase the friction between the plastic tube 11 and the first braid 20, the plastic tube 11 can be structured, for example, in the region of its outer jacket.

The first braid 20 may, for example, also be provided with additionally braided high strength fibers, which need not necessarily be electrically conductive, e.g. made of aramid or carbon fibers, mechanically reinforced. This also applies accordingly to the second braid 40.

In addition to the insulating layer 30, further coatings and / or intermediate layers can be arranged between the first braid 20 and the insulating layer and / or between the second braid 40 and the insulating layer 30. As a result, if appropriate, the insulating effect between the two braids 20, 40 can be improved. It is also conceivable to provide an additional strain relief layer in the region of the insulation layer 30 between the two braids 20, 40. In addition, the insulating layer 30 can also be provided with mixed-in tensile fibers and / or integrated reinforcing elements, if deemed necessary.

It is also conceivable to omit the strain relief layer 50 and instead integrate, for example, reinforcing elements and / or tensile fibers in the outer shell.

Furthermore, it is for example possible to provide additional layers of stranded wires at a suitable location in the electro-optical cable 1. The additional layers can serve depending on the material as electrical conductors and / or tensile elements.

In principle, it is also conceivable to deviate from a circular cross-section and e.g. to provide an oval cross-sectional shape.

It is also possible to integrate additional metal foils and / or swelling tapes as shielding and / or moisture protection in the cable.

In addition to the two braids 20, 40, other braids and / or other electrical conductors can be arranged. It is also conceivable in principle to replace the second braid 40 by a layer of stranded wires, if this appears to be advantageous.

In particular, the dimensions given and, more particularly, the configurations of the braids 20, 40 are to be understood as illustrative only and may be modified according to the requirements, for example as mentioned in the general part of the specification.

It is also understood that the electro-optical cable 1 can also be used for applications other than the remote feeding of a mobile power network shown in Fig. 3d.

In summary, it should be noted that a novel electro-optical cable has been created, which is characterized in particular by an improved flexural flexibility and improved mechanical strength and robustness. As a result, the cable according to the invention is more flexible and enables safe and efficient energy and / or data transmission even under harsh conditions.

Claims (22)

1. An electro-optical cable (1) for data transmission and / or energy transmission, comprising a central loose tube (10), wherein in the central loose tube at least one optical waveguide (12a, 12b, 12c, 12d) is arranged and wherein the central loose tube (10) is surrounded by at least one first tubular and electrically conductive braid (20) in a coaxial arrangement, characterized in that the at least one optical waveguide (12a, 12b, 12c, 12d) loosely in the central bundle core (10), wherein the central loose tube ( 10) has an outer diameter of at most 4 mm. 2. Electro-optical cable (1) according to claim 1, characterized in that the central loose tube (10) consists of a plastic tube (11), wherein the plastic tube in particular consists of polyamide, polypropylene, polybutylene terephthalate and / or polyethylene. 3. Electro-optical cable (1) according to any one of claims 1 or 2, characterized in that the at least one optical waveguide (12a, 12b, 12c, 12d) loosely in the filled with a fluid wire filler compound (15) central bundle core (10). 4. Electro-optical cable (1) according to one of claims 1 to 3, characterized in that a ratio of an outer diameter (20.1) of the first braid (20) to an outer diameter (11.2) of the central loose tube (10) has a value of 1.2-1.6 , preferably 1.35-1.45. 5. Electro-optical cable (1) according to one of claims 1 to 4, characterized in that the at least one optical waveguide (12a, 12b, 12c, 12d) relative to the central loose tube (10) has an excess length, preferably in the range of 0.05 -0.2 %. 6. Electro-optical cable (1) according to any one of claims 1 to 5, characterized in that the first electrically conductive mesh (20) consists of metal wires (21a, 21b, 21c), in particular copper wires, which particularly preferably have a diameter of 0.05 -0.2 mm. 7. Electro-optical cable (1) according to claim 6, characterized in that the first electrically conductive braid (20) consists of 8-36 braided bundles (21) of 1-12 metal wires (21a, 21b, 21c). 8. Electro-optical cable (1) according to any one of claims 1 -7, characterized in that the first electrically conductive braid (20) with respect to a longitudinal central axis (14) of the electro-optical cable (1) has a braid angle (23.1) of 45-80 °, preferably 60-75 °. 9. Electro-optical cable (1) according to claim 1 to 8, characterized in that the first electrically conductive mesh (20) has an area coverage of 80 - 99%, preferably 85 - 95%. 10. Electro-optical cable (1) according to one of claims 1 to 9, characterized in that the first electrically conductive braid (20) by a coaxially arranged second tubular and electrically conductive braid (40) is surrounded, in particular the first electrically conductive braid (20) is electrically isolated from the second electrically conductive braid (40). 11. An electro-optical cable (1) according to claim 10, characterized in that the second electrically conductive braid (40) consists of metal wires (42a, 42b, 42c), in particular of copper wires, which particularly preferably have a diameter of 0.05 - 0.2 mm , wherein further preferably, the first electrically conductive braid (20) and the second electrically conductive braid (40) consist of substantially identical metal wires (22a, 42a). 12. Electro-optical cable (1) according to claim 11, characterized in that the second electrically conductive braid (40) consists of 8-36 braided bundles (41) of 1-12 metal wires (42a, 42b, 42c), in particular a Number of braided bundles of the first electrically conductive braid (20) and a number of the braided bundles of the second electrically conductive braid (40) are the same, and more preferably, a number of the metal wires (22a, 22b, 22c) of the braided bundles (21) of the first electrically conductive metal braid (20) is equal to a number of the metal wires (42a, 42b, 42c) of the braided bundles (41) of the second electrically conductive metal braid (40). 13. An electro-optical cable (1) according to any one of claims 10 to 12, characterized in that the second electrically conductive braid (40) with respect to the longitudinal central axis (14) of the electro-optical cable (1) has a braid angle (43.1) of 45-80 °, preferably 60-75 °, and in particular that the first electrically conductive braid (20) and the second electrically conductive braid (40) have substantially an identical braid angle (23.1, 43.1). 14. An electro-optical cable (1) according to any one of claims 10 to 13, characterized in that a surface coverage of the second electrically conductive braid (40) is less than the area coverage of the first electrically conductive braid (20), wherein preferably the area coverage of the first electrically conductive mesh (20) by a factor 1.3- 1.5 is greater than the area coverage of the second electrically conductive mesh (40). 15. Electro-optical cable (1) according to claim 14, characterized in that the area coverage of the second electrically conductive braid (40) is 50-90%, preferably 60-70%. 16. An electro-optical cable (1) according to any one of claims 10 to 15, characterized in that a first electrical resistance of the first electrically conductive braid (20) is substantially equal to a second electrical resistance of the second electrical braid (40). 17. Electro-optical cable (1) according to any one of claims 10-16, characterized in that between the first electrically conductive braid (20) and the second electrically conductive braid (40) an insulating layer (30) is arranged for electrical insulation. 18. Electro-optical cable (1) according to claim 17, characterized in that the insulating layer (30) consists of a plastic, preferably of polyamide, and / or that the insulating layer (30) in a radial direction of the electro-optical cable (1) has a thickness from 0.25 to 0.50 mm. 19. Electro-optical cable (1) according to one of claims 1 to 18, characterized in that an outermost electrically conductive braid (40) by a strain relief layer (50) is surrounded, in particular the strain relief layer (50) consists of synthetic fibers, wherein it is particularly preferably aramid fibers. 20. An electro-optical cable (1) according to any one of claims 1 to 19, characterized in that an outer jacket (60) is present, wherein the outer jacket (60) in particular of a polyamide, ethylene-propylene rubber (EPR), polyethylene, and / or polyurethane. 21. Arrangement (100) comprising a first transformer (110) and a second transformer (120), wherein the two transformers (110, 120) via an electro-optical cable (1) according to one of claims 1 to 18 are electrically connected. 22. Use of an electro-optical cable (1) according to one of claims 1 to 20 as an electrical connection line between two voltage transformers (110, 120), in particular between a hard-wired and a controllable transformer.