EP2954537B2 - Hybrid cable, method for producing same, and use of such a hybrid cable - Google Patents

Description

The invention relates to an electrical cable, also referred to as a hybrid cable, having the features of the preamble of claim 1. Furthermore, the invention relates to the use of such an electrical cable.

Such a line is, for example, in the US 2013/0277087 A1 described.

Cables and electrical lines are often exposed to mechanical stress. This results in relatively high demands on the durability and reliability of the cable for safety-critical applications, such as those in motor vehicles. Axle wiring in particular, such as signal lines for wheel speed sensors or power lines for supplying power to brakes, is usually subject to repeated bending, compression, and crushing loads. Further stresses often arise from changing environmental conditions, particularly when a cable is exposed to different temperature ranges. In addition to the requirements during operation, certain requirements also arise during the installation of the cable in the vehicle. The cable is often provided with connecting elements, in particular connectors, during assembly, or the cable is additionally prepared.

In the US 2013/0277087 A1 For example, a complex cable harness is described in which an ABS sensor cable and a brake cable are covered by a common outer sheath. By integrating two cables with different functions into a common cable harness, the installation space required is reduced. The ABS sensor cable also comprises two wires that are covered by a common inner sheath. In one development, the outer and inner sheaths are each made of a thermoplastic urethane. To prevent the two sheaths from sticking together when the outer sheath is applied, the inner sheath material is additionally cross-linked in one development; in another development, however, cross-linking is omitted and the inner sheath is surrounded by a separating layer. In one variant, both cables of the cable harness are jointly surrounded by a circular shield, which can also be designed as a separating layer, with the gussets formed by the cables being filled with additional filler material.

The EP 1 589 541 A1 describes a flexible electrical power and control cable comprising two signal wires and two supply wires surrounded by an inner shield, with the entire assembly being surrounded by an additional, outer shield. This achieves particularly good electrical transmission properties. The shields are each made of a metallized plastic fleece, which is particularly slightly stretchable so that the inner shield is pressed by the supply wires into the gussets formed by the signal wires. The outer shield is essentially round, which makes it possible to arrange drain wires in the remaining spaces to further improve the shielding effect.

Another flexible electrical cable shows the EP 2 019 394 A1 , the cable here comprising a core having a compressible sheath with a sliding layer applied thereto.

The DE 102 42 254 A1 describes an electrical cable for connecting movable electrical consumers, in which several wires are each connected by a

Insulation is provided which has an inner and an outer layer, the inner layer being softer than the outer layer. The cores are in turn surrounded by a common inner sheath. A separating layer made of powder is arranged between the cores and the inner sheath, whereby the inner sheath also fills the gaps formed by the cores. The separating layer ensures, in particular, relative mobility between the cores and the inner sheath. Similar to insulation, the inner sheath consists of an inner layer facing the cores and an outer layer, the inner layer being softer than the outer layer. The structure of the inner sheath allows, in particular, the cable to be assembled in such a way that only the outer layer is severed and the inner layer is then torn off.

The invention is based on the object of specifying a cable and its use, wherein the cable is suitable for safety-critical applications and, in particular, meets high requirements regarding its durability, robustness, and reliability. In particular, in addition to these operational requirements, the cable should also be as easy to install as possible, meaning, in particular, it should be as simple as possible to assemble and be as easy to handle during installation as possible.

The object is achieved according to the invention by an electrical cable according to claim 1 and by a use of the cable according to claim 13. Advantageous embodiments, further developments, and variants are the subject of the subclaims. The embodiments and advantages mentioned in connection with the cable also apply mutatis mutandis to the use, and vice versa.

The electrical cable comprises at least three wires, each with a conductor surrounded by a wire sheath, two of the wires being designed as signal wires and another of the wires being designed as a power wire. The signal wires form a first One sub-cable, in particular a signal cable, and the power cable form a second sub-cable, in particular a power cable. The two sub-cables each fulfill different functions during operation, which is why the electrical cable is also referred to as a hybrid cable.

The wires, in particular all the wires of the cable, are further enclosed by a separating sheath, which in turn is enclosed by the common sheath of the electrical cable. In other words, the two sub-wires are combined by the separating sheath and the common sheath applied to it, thus forming the electrical cable.

The advantages achieved with the invention are, in particular, that the cable has particularly good bending strength and a long service life, especially under repeated loads. The cable and in particular the signal cable itself are therefore particularly robust, for example with regard to bending, tensile, compressive or compressive loads. The robustness of the signal cable is particularly relevant with regard to its transmission properties. The signal wires are advantageously held immobile relative to one another or relative movement of the signal wires to one another is at least greatly reduced, thereby ensuring, in particular, error-free or at least error-reduced signal transmission. In particular, when the signal cable is used in combination with a wheel speed sensor, a more precise and robust transmission of a wheel speed signal is ensured, which in turn improves the speed determination carried out with it.

The signal wires are surrounded by a common partial cable sheath, which in a preferred embodiment has an inner and an outer sheath section, wherein the outer sheath section is harder than the inner sheath section, i.e. is made of a harder material than the inner sheath section. This special material selection with regard to the different hardnesses of the sheath sections of the partial cable sheath improves the robustness of the signal cable. A particular further advantage of this material selection results in the overall cable assembly in that the outer, i.e. harder, sheath section, on the one hand, protects the internal signal wires, in particular from the other elements of the cable, and on the other hand, is sufficiently hard to displace the power wires routed adjacent to the signal line in the overall assembly, in particular in such a way that any localized pressure load on the signal wires from the power wires is prevented.

Here and in the following, "harder" means in particular that the Shore hardness of the harder material is higher than that of the relatively softer material, i.e. the harder material is harder by a certain number of Shore hardness degrees. The Shore hardness is suitably determined by a penetration test on the respective material using a spring-loaded pin. For example, the test is carried out according to the standards known for determining the hardness degrees for elastomers and plastics, in particular by means of a so-called Shore D test to determine the Shore D hardness. The outer shell section is then preferably at least two Shore D hardness degrees harder than the inner shell section.

The signal cable itself is also particularly robust, especially after cable assembly—that is, after removing the common sheath and exposing a certain length of the signal cable. Due to the harder outer sheath section, the exposed signal cable is particularly protected, for example, against impacts, and, thanks to the softer inner sheath section, is also particularly flexible.

The signal line is used in particular to transmit an electrical signal, for example a sensor signal, whereas the power line is used to transmit electrical power and supply an electrical consumer. Therefore, the power line typically has a larger conductor cross-section than the signal lines. Depending on how the consumer is connected to ground, a second power line may be present; the power line then comprises two lines. However, particularly in the automotive sector, it is common practice to use the body of a motor vehicle as a common ground; in this case, only one power line is required. Therefore, without loss of generality, the following will initially assume only one power line. In the case of a second power line, both power lines are then designed in particular to be identical.

Each of the cores comprises a conductor, which is preferably a stranded conductor made from a plurality of wires. Such stranded conductors are significantly more flexible than single-piece conductors with a similar cross-section and therefore advantageously contribute to the bending flexibility of the hybrid cable. The conductor consists, for example, of copper, a copper alloy, or aluminum and is surrounded by a core sheath, which preferably consists of only one material, i.e., is applied in a single layer. Such cores are particularly easy to manufacture and are provided, for example, as pre-assembled cores during the manufacturing process of the hybrid cable.

The signal wires are surrounded by a partial cable sheath, particularly for their protection, thus forming the first partial cable. In the radial direction, the partial cable sheath is divided into two sheath sections: an inner and an outer sheath section. These are made of different materials such that the inner sheath section is softer than the outer one. The inner sheath section extends The sheath section preferably extends approximately halfway up to the total radius of the first sub-cable, and the outer sheath section extends correspondingly over the remaining total radius. This allows for improved balancing between compression and compression zones, particularly when bending the signal cable. Within the context of the entire hybrid cable, the signal cores are also advantageously protected against external mechanical stresses, for example, against compressive stress from the typically more massive power cores.

For production, the two sheath sections are suitably applied in a two-layer process, for example, by extrusion. First, the inner sheath section is applied to the two signal wires, particularly filling the gaps between the signal wires. The inner sheath section is also preferably applied with a circular outer contour. The outer sheath section is then applied to the inner sheath section. This outer sheath section preferably also has a circular outer contour and is then formed as a ring.

The partial cable sheath, and in particular the appropriate selection of the overall radius during the manufacture of the first partial cable, also allows the distance between the signal cable and the power cable in the hybrid cable to be advantageously adjusted with regard to the electrical properties. During operation, the appropriately selected distance prevents or at least reduces potential crosstalk between the signal and power wires; the partial cable sheath then acts as a spacer. This function is particularly useful in applications where the signal and power cables may be operated simultaneously.

As a suitable alternative or in addition, it is possible to provide the entire cable, one or both sub-cables, or the individual wires with separate shielding, thus improving the electrical transmission properties. However, if simultaneous transmission via the signal and power cables is not required during operation, such additional shielding is preferably omitted, making the hybrid cable easier and more cost-effective to manufacture.

In the overall electrical cable assembly, the specially constructed partial cable sheath therefore fulfills several functions: firstly, it protects the signal wires both in the overall assembly and when the signal cable is laid separately; secondly, it ensures particularly high bending flexibility of the signal wires; and thirdly, it makes it possible to advantageously adjust the electrical properties of the overall assembly.

The two partial cables are combined by the common sheath, also referred to as the outer sheath. This has, in particular, a circular outer contour, which simultaneously also serves as the outer contour of the entire hybrid cable. In other words, the outer surface of the common sheath also forms the outer surface of the electrical cable. The outer sheath is preferably extruded and single-layered, i.e., made of only one material. To improve the bending flexibility of the hybrid cable, the outer sheath is expediently softer than the outer sheath section of the partial sheath. This then enables, in particular, displacement of the softer outer sheath material by the harder material of the outer sheath section. In a suitable embodiment, the entire sheath is at least ten Shore D hardness levels softer than the outer sheath section.

The partial cable sheath of the first partial cable and/or the common sheath of the electrical cable is/are preferably made of a thermoplastic polyurethane elastomer, also referred to as TPE-U. This material is particularly robust and easy to process and is often used to manufacture housings for functional elements such as connectors. Forming a respective sheath from this material then advantageously enables a particularly durable molding of a housing onto the hybrid cable or the signal cable, i.e., it enables particularly simple overmolding of the respective sheath. In particular, the material is not cross-linked and is therefore particularly suitable for being melted or partially melted and overmolding in a subsequent process step.

The connection between the housing and the sheath is also particularly tight, as the housing is bonded to the sheath during molding, particularly with a material fit and/or a precise fit. During operation, this advantageously prevents dirt and moisture from penetrating the hybrid cable and/or the signal line. In a particularly suitable embodiment of the electrical cable, a functional element is connected to the first sub-cable, with a housing made of a material that can be chemically and/or physically bonded to the material of the outer sheath section. The housing is, for example, an overmolded part, a connector housing, or a grommet.

Chemically bondable is understood in particular to mean a material connection between the two materials. A particularly preferred embodiment is one in which the housing and the corresponding casing are made of the same material. Physically bondable, on the other hand, is understood in particular to mean a precisely fitting attachment of the housing, wherein the housing is held to the respective casing in particular by static friction. For example, the housing is provided as a finished part, expanded using compressed air, and placed on the line or one of the sub-lines. After the compressed air is switched off, the housing lies positively around the corresponding cable and is held particularly firmly together by the additional static friction of the two physically connectable materials. In the case of the signal cable in particular, the particularly circular design of the partial cable sheath due to the two-layer process used contributes to the physical connection, as this achieves a particularly precise fit between the housing and the sheath. The first partial cable is therefore particularly suitable for the tight and secure attachment of a housing for a shaped element. The concepts described here are not limited to the first partial cable, however; rather, a chemical and/or physical bonding of a housing, in particular with the entire sheath of the hybrid cable or with a sheath of the second partial cable, is also advantageously possible.
In the case of thermoplastic polyurethane elastomers, the degree of hardness can also be easily adjusted by selecting the material composition and is therefore particularly suitable for forming the partial cable sheath with sheath sections of varying hardness. The partial cable sheath then consists of several materials, in particular just two, which, although they have different hardnesses, are both thermoplastic polyurethane elastomers and are bonded to one another in a particularly strong, i.e., materially bonded manner during the production of the partial cable sheath. In this way, a partial cable sheath is provided which, although it has a varying hardness in the radial direction, can be removed in one piece during the assembly of the first partial cable, i.e., in particular, during stripping. The described material selection therefore offers advantages both in the operation of the hybrid cable and in its handling during installation, particularly during assembly.

In an advantageous embodiment, the sheath of the power wire is softer than the outer sheath section. Similar to the softer common sheath described above, this results in the advantage that the sheath of the power line yields when the signal line is subjected to mechanical stress, which in turn protects the signal wires. Advantageously, the signal wires are also each similarly enclosed with a sheath that is softer than the outer sheath section, with the same material being used for all sheaths.

At least one core sheath, and expediently all core sheaths, are preferably made of polyethylene, in particular of cross-linked polyethylene. The latter is also referred to as XLPE. This material is easy to process, has an advantageous sliding effect, and is also available in particular with a hardness that preferably lies between the respective hardness of the inner and outer sheath sections. Thus, the core sheaths of the signal cores are relatively hard with respect to the surrounding inner sheath section, and the core sheath of the power core is relatively soft with respect to the adjacent outer sheath section. This makes it possible, in particular, to use the same material for all core sheaths and at the same time ensure correspondingly improved bending flexibility.

In order to enable residue-free stripping of at least one of the wires, preferably all of the wires, the respective wire is designed such that a wire separation layer in the form of a heat-sealing layer is arranged between its conductor and its wire sheath. The heat-sealing layer, which is applied in particular without gaps, separates the wire sheath from the conductor and advantageously has improved sliding properties compared to the conductor material, so that stripping is particularly easy and possible with reduced force. During wire production, the heat-sealing layer is first applied to the conductor, in particular as a film. The sheath is then extruded on, whereby the heat-sealing layer bonds with the sheath material in such a way that it is advantageously removed without leaving any residue during stripping.

The sub-cables form a sub-cable bundle surrounded by the separating sleeve, which is adapted to the outer contour of the sub-cable bundle. "Adapted" specifically means that the separating film follows the contour formed by the sub-cable bundle in the cross-section of the hybrid cable and is accordingly inserted into the interstices of the sub-cable bundle. This advantageously eliminates the need for additional filling material, thus avoiding a corresponding additional process step, particularly during manufacturing.

In a suitable embodiment, the separating sleeve is a plastic fleece or a plastic film, i.e., in particular, a separating film made of a plastic. In contrast to a separating sleeve made of powder, a separating film can be removed particularly easily without leaving any residue when stripping the insulation, thus simplifying the assembly of the cable. Residue-free removal is also particularly important for the subsequent molding of functional elements. With a powder separating layer, the respective cable would first have to be cleaned of any remaining powder before being overmolded. In a preferred embodiment, the partial cables are therefore designed without a separating agent, i.e., their outer surfaces are not provided with a separating agent, in particular not with a powdered or pasty separating agent. This eliminates the need for additional cleaning. Rather, when using a separating film, it can be peeled off, in particular together with the common sheath, and can advantageously be removed without leaving any residue. In general, any continuous film or layer material is suitable as a separating sleeve, for example, a nonwoven material, a paper material, a textile material, or a combination thereof. However, a plastic material is particularly preferred, which in particular is metallized, as this has particularly suitable tear-off behavior as well as good stability and bending flexibility.

In a suitable development, the separating sleeve, in particular a separating film, is applied longitudinally to the two partial cables. Such a longitudinally applied separating film exhibits particularly favorable tear-off behavior, which in turn simplifies the assembly of the hybrid cable. Since longitudinal application is significantly faster than, for example, taping, such a hybrid cable can be manufactured particularly quickly, meaning it can also be produced in correspondingly higher quantities per time.

To apply the separating sleeve, it is preferably placed as a band with a specific longitudinal seam overlap and a suitable width around the partial cable bundle. The longitudinal inlet is preferably spiralized. The separating sleeve is applied particularly while the partial cables are twisted together and is also applied with a twist such that the longitudinal seam follows the twisted course of the partial cables in a spiral shape. This means in particular that the longitudinal seam extends lengthwise along the partial cables, in contrast to banding, which is usually carried out separately and is therefore more complex in terms of processing. In a suitable alternative, the separating sleeve is only applied after the partial cables have been bundled, before or during the application of the common jacket of the hybrid cable. In this case, the longitudinal seam extends straight in the longitudinal direction of the hybrid cable. The common jacket is then applied, preferably by extrusion. The insertion of the separating film into the gussets is then preferably achieved by the contact pressure during the application of the common jacket. The longitudinal seam overlap is then selected in particular in such a way that the longitudinal seam overlap remaining after the application of the common jacket is as small as possible.

The conductors of the signal cores, i.e. in particular their wires, are preferably made of a copper alloy, which has improved sliding properties compared to pure copper and thus contributes to the bending flexibility of the signal line. However, since significantly more conductor material is required to manufacture the power core due to its larger cross-section compared to the signal cores, the conductor is preferably made of copper and is therefore at least cheaper than a copper alloy. To still achieve improved sliding properties for the power core, its wires are expediently stranded together using a special process to form a leg strand: For this purpose, the wires of the core are first combined into several bundles, and each of the bundles is twisted together in a leg lay direction to form a leg. These legs are then twisted together to form a leg strand. One of the legs is a central leg, the leg lay direction of which is opposite to the leg lay direction of the surrounding other legs, and around which these other legs are stranded in the opposite direction to their leg lay direction.

For example, the conductor comprises seven legs in a 1 + 6 stranding. Here, the wires of the inner leg, i.e. the central leg, are twisted in the opposite direction to the wires of the respective outer bundles. In the contact area between the outer legs and the central leg, the wires then advantageously run crosswise, which prevents them from slipping into each other when the core is bent. The outer legs are stranded in the opposite lay to the leg lay direction of these bundles, which improves the bending flexibility of the core, particularly because the individual wires run straighter than in a design with giro lay. Overall, a core formed as a leg strand using the above process therefore exhibits improved mechanical behavior and improved positional compensation of the wires under combined loads.

By combining this special stranding with copper as the conductor material, it is then possible, particularly in the case of power wires, to produce a wire with particularly good sliding and bending behavior from copper, which is more cost-effective than a copper alloy. This special stranding is also suitable in principle for signal wires, which, however, are preferably made from a copper alloy as described above due to a balance between manufacturing effort and material costs and are then stranded in a conventional manner. The signal wires preferably each have a conductor designed as a strand, with the conductors being formed with a common strand lay direction. The signal wires are then preferably twisted in a common lay with respect to this strand lay direction, resulting in particularly advantageous electrical transmission properties.

To further improve the mechanical properties of each core, the wires of this core are suitably twisted with a pitch of at least 60 mm and at most 150 mm, preferably approximately 100 mm. The diameter of each wire is approximately between 0.05 mm and 0.11 mm. The diameter of each partial conductor is then, in particular, approximately between 3 mm and 11 mm.

In order to achieve a tension-free stranding of the wires of each leg, the legs are twisted together with a reverse twist. The corresponding unwinding spools are not held in place during stranding, but rather rotated against the direction of rotation of the stranding cage, which advantageously reduces the torsion of the individual legs and, in particular, their wires.

According to a preferred embodiment, in the overall electrical cable assembly, the wires of the first sub-cable are twisted together and then twisted with the power wire of the second sub-cable. In particular, in the case of multiple power wires, these are first twisted together and then the first sub-cable is twisted with the second sub-cable.

After applying the common sheath, which is particularly the outermost sheath of the cable, the cable preferably has an outer diameter of 7 mm to 11 mm. This makes the cable particularly suitable for use in the automotive sector. The first sub-cable expediently serves as a signal cable and is connected to a wheel speed sensor in the motor vehicle, and the second sub-cable serves as a power cable and is connected to an electric brake actuator, in particular a parking brake of the motor vehicle.

The twisted and triple-stranded wires described above advantageously ensure interference immunity such that a signal can be transmitted via the signal line and electrical power to supply an actuator can be transmitted via the power line. This makes it possible to use the electric parking brake as an emergency brake. In other words, the power line is not only used to transmit power in a resting state, for example, when the vehicle is stationary or parked, but also advantageously when needed in a dynamic driving state.

Instead of prefabricating and molding functional elements during the electrical cable assembly, it is also possible to manufacture the cable completely with the functional elements attached. In a particularly suitable embodiment, a functional element, in particular a speed sensor, is connected to one end of the first partial cable with a housing that is integrally bonded to the outer jacket section. In a suitable refinement, the other end of the first partial cable and/or the ends of the second partial cable are each provided with a connector.

Fig. 1

eine elektrische Leitung im Querschnitt,

Fig. 2

ausschnittsweise die Leitung gemäß Fig. 1 in einer Seitenansicht, und

Fig. 3

eine als Schenkellitze ausgebildete Ader der Leitung gemäß Fig. 1.

An embodiment of the invention is explained in more detail below with reference to a drawing. The drawings schematically show:

Fig. 1

an electrical cable in cross-section,

Fig. 2

section of the line according to Fig. 1 in a side view, and

Fig. 3

a stranded wire of the cable in accordance with Fig. 1 .

In the Fig. 1 , a cross-section of an electrical cable 2 is shown, which is designed as a hybrid cable and for this purpose comprises two partial cables 4, 6. The first partial cable 4 here is a signal cable, which has two signal wires 8, which are surrounded by a common partial cable sheath 10. The second partial cable 6, on the other hand, is designed here as a power cable and for this purpose comprises two power wires 12 with a larger cross-section than the signal wires 8 and without a common partial cable sheath. The wires 8, 12 each comprise a conductor 8a, 12a and a wire sheath 8b, 12b surrounding this conductor. In order to facilitate the separation of the respective wire sheath 8b, 12b, in particular, a wire separation layer 13 is arranged between this conductor and the associated conductor 8a, 12a, which is designed here as a heat-sealing layer and is integrally connected to the respective wire sheath 8b, 12b.

The partial cable sheath 10 of the first partial cable 4 is formed in two layers, with an inner sheath section 10a initially surrounding the two signal wires 8 and also filling the gaps formed between the signal wires 8. This inner sheath section 10a also has a circular outer contour. Adjoining the inner sheath section 10a in the radial direction is an outer sheath section 10b, which is particularly annular in this case. The outer sheath section 10b is made of a harder material than the inner sheath section 10a and is integrally bonded to it.

In the embodiment shown here, both jacket sections 10a, 10b are made of a thermoplastic polyurethane elastomer, with the material composition being varied such that the outer jacket section 10b is harder. The transition from the inner to the outer jacket section 10a or 10b is in Fig. 1 indicated by a dashed line. It is clear that the outer sheath section 10b extends approximately over half the total radius R of the signal line 4 and, at the same time, serves in particular as a spacer between the signal wires 8 and the power wires 12.

The two partial lines 4, 6 are surrounded by a common separating sheath 14, which is inserted into the Fig. 1 and 2 is shown as a reinforced line. This separating sleeve 14 is a separating film made of plastic, which runs lengthwise around the partial cables 4, 6 and lies in the gaps formed by the two partial cables 4, 6. Additional filling elements between the partial cables 4, 6 and the separating sleeve 14 have been omitted. Both partial cables 4, 6 are finally combined by a common sheath 16, which is applied to the common separating sleeve 14. The separating sleeve 14 makes it possible in particular for the common sheath 16 and the partial cable sheath 10 to be made of the same material and yet to be easily separated from one another during assembly. The common sheath 16 also has a circular outer contour, with a diameter of approximately 10 mm here, which also corresponds to the outer diameter D of the electrical cable 2. The common sheath 16 is therefore also an outermost sheath of the cable 2.

In the Fig. 2 is a section of line 2 according to Fig.1 shown in a side view. The two signal wires 8 with the surrounding partial cable sheath 10 as well as the two power wires 12 are clearly visible. In addition, a dashed line indicates a housing 18 of a functional element, e.g., a speed sensor. The power wires 12, on the other hand, are provided with a suitable connector and connected to a brake actuator (not shown in detail here). The housing 18 is made of the same material as the signal line 4, in the variant shown, in particular, of a thermoplastic polyurethane polymer, and is also integrally formed onto the partial cable sheath 10, making the connection particularly tight and robust. The common sheath 16 has been stripped to such an extent that the two partial cables 4, 6 partially protrude and can be laid and connected as separate cables at different locations. The harder sheath section 10b, in particular, ensures particularly good stability of the separately routed signal line 4.

It is clearly visible in Fig. 2 Also shown is the separating sleeve 14, which was removed without leaving any residue when stripping the common sheath 16. Since no residue remains on the partial cable sheath 10, the molding of the housing 18 onto the partial cable 4 is particularly simplified.

In the embodiment shown here, the conductors 8a of the signal wires 8 are each made of a plurality of wires, each made of a copper alloy. In contrast, the conductors 12a of the power cable 6 are made of copper and formed as leg strands using a special stranding process.

To clarify the structure of the conductors 12a of the power wires 12, an embodiment of one of the conductors 12a is shown in Fig. 3 This is shown as a leg strand with seven legs 20, 22 in an exemplary 1 + 6 stranding. The centrally arranged leg 20 represents a central leg, around which the remaining legs 22 are stranded.

Each of the legs 20, 22 comprises a plurality of wires 24 which are twisted together in a respective leg lay direction S1, S2. The leg lay direction S1 of the central leg 20 corresponds to the opposite direction of the leg lay direction S2 of the outer legs 22. The stranding of these outer legs 22 around the central leg 20 also takes place in the opposite direction to their leg lay direction S2 and thus in the direction of the leg lay direction S1 of the central leg 20. This results in a crossing course of the respective wires 24 in the intermediate region Z, in which a respective leg 22 rests against the central leg 20. Furthermore, the counter-lay of the outer legs 22 with respect to their respective leg lay direction S2 results in a largely straight course of the corresponding wires 24. The power core 12 formed in this way then has a particularly high bending flexibility.

List of reference symbols

2

electrical cable, hybrid cable

4

first sub-line (signal line)

6

second sub-line (power line)

8

Wire (signal wire)

8a

Director

8b

vein sheath

10

Partial cable sheath

10a

inner shell section

10b

outer shell section

12

Wire (power wire)

12a

Director

12b

vein sheath

13

Wire separation layer

14

Divider sleeve

16

common coat

18

Housing (of a functional element)

20

central limb

22

leg

24

wire

D

Outer diameter

R

Total radius of the first sub-line

S1, S2

Thigh strike direction

Z

Intermediate area

Claims (13)

1. Electrical line (2), comprising at least three cores (8, 12) each having a conductor (8a, 12a) surrounded by a core coating (8b, 12b), wherein

   - two of the cores (8) are formed as signal cores and form a first partial line (4), in particular signal line, with a mutual partial line coating (10) surrounding these,

   - a further one of the cores (12) is formed as a power core and forms a second partial line (6), in particular power line, characterised in that

   - the two partial lines (4, 6) are surrounded by a mutual separating shell (14) which is in turn surrounded by a mutual coating (16) of the electrical line (2),

   - the partial lines (4, 6) form a partial line bundle which is surrounded by the separating shell (14), wherein this is adapted to the outer contour of the partial line bundle.
2. Line according to the preceding claim,
   characterised in that
   the partial line coating (10) has an inner coating section (10a) as well as an outer coating section (10b) and the outer coating section (10b) is harder than the inner coating section (10a).
3. Line (2) according to one of the preceding claims,
   characterised in that
   the mutual coating (16) is softer than the outer coating section (10b).
4. Line (2) according to one of the preceding claims,
   characterised in that
   a functional element is connected to the first partial line (4), having a housing (16) which is produced from a material which is able to be connected chemically and/or physically to the material of the outer coating section (10b).
5. Line (2) according to one of the preceding claims,
   characterised in that
   the core coating (12b) of the core (12) formed as a power core is softer than the outer coating section (10b).
6. Line (2) according to one of the preceding claims,
   characterised in that
   at least one core coating (8b, 12) is formed from polyethylene, in particular from a cross-linked polyethylene.
7. Line (2) according to one of the preceding claims,
   characterised in that
   at least one of the cores (8, 12) is formed in such a way that a core separating layer (13) formed as a heat seal layer is arranged between the conductor (8a, 12a) thereof and the core coating (8b, 12b) thereof.
8. Line (2) according to one of the preceding claims,
   characterised in that
   the separating shell (14) is a plastic fleece or a plastic film.
9. Line (2) according to one of the preceding claims,
   characterised in that
   the two partial lines (4, 6) are designed to be free of separating means.
10. Line (2) according to one of the preceding claims,
    characterised in that
    the separating shell (14) is applied to the two partial lines (4, 6) to shrink longitudinally, in particular in a spiral.
11. Line (2) according to one of the preceding claims,
    characterised in that
    the cores (12) of the second partial line (6) each comprise several wires (24), the wires (24) of a respective core (12) are firstly combined into several bundles, each bundle is twisted in a limb lay direction (S1, S2) into a limb (20, 22) and the limbs (20, 22) are twisted into a limb braid, wherein one of the limbs (20, 22) is a centrally guided limb (20), the limb lay direction (S1) of which is opposed to the limb lay direction (S2) of the remaining limbs (22) surrounding this, and around which these remaining limbs (22) are twisted in the opposite direction to the limb lay direction (S2) thereof.
12. Line (2) according the preceding claim,
    characterised in that
    the limbs (20, 22) are twisted with respect to each other using reverse twisting.
13. Use of a line (2) according to one of the preceding claims,
    characterised in that
    the first partial line (4) is connected to a wheel speed sensor in a motor vehicle as a signal line, and the second partial line (6) is connected to an electrical brake actuator, in particular an electrical parking brake of the motor vehicle, as a power line.

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