Bend-flexible electrical cable

Abstract

A flexible electrical cable is provided that extends in a longitudinal direction and contains a conductive core, with a reinforcing layer for limiting a bending radius mounted around the conductive core. The reinforcing layer is formed from at least one strand wound around the conductive core, which has winding sections with support surfaces. The support surfaces of adjacent winding sections are supported on each other to limit a bending radius.

Claims

1. A flexible electrical cable extending in a longitudinal direction, the flexible electrical cable comprising: a conductive core; and a reinforcing layer for limiting a bending radius of the cable and mounted around said conductive core, said reinforcing layer having a strand wound around said conductive core with winding sections that each have support surfaces, and said winding sections are capable of displacement relative to one another when the flexible electrical cable is bent in the longitudinal direction, until adjacent winding sections bear on one another to limit the bending radius of the cable.

2. The flexible electrical cable according to claim 1, wherein the flexible electrical cable is a charging cable for an electric motor-driven vehicle and for electrical currents greater than 50 amps.

3. The flexible electrical cable according to claim 1, wherein said winding sections are formed as profiles and overlap and abut each other in the longitudinal direction, so as to form a closed reinforcing layer.

4. The flexible electrical cable according to claim 1, wherein said winding sections each of the inner section and the outer section have an inner section and an outer section, and each have a support surface at both ends in the longitudinal direction.

5. The flexible electrical cable according to claim 4, wherein said inner section of a first winding section of said winding sections is slidably supported on said outer section of a subsequent winding section of said winding sections.

6. The flexible electrical cable according to claim 1, wherein said support surfaces are formed as flat surfaces oriented perpendicular to the longitudinal direction.

7. The flexible electrical cable according to claim 1, wherein said winding sections are each formed in a manner of a Z profile.

8. The flexible electrical cable according to claim 1, wherein said reinforcing layer contains a metal.

9. The flexible electrical cable according to claim 8, wherein said reinforcing layer has a ferromagnetic metal.

10. The flexible electrical cable according to claim 1, wherein said reinforcing layer is surrounded by an outer jacket.

11. The flexible electrical cable according to claim 1, wherein said conductive core contains a plurality of electrical conductive elements surrounded by an intermediate jacket.

12. The flexible electrical cable according to claim 1, wherein said strand is formed from a flat band by a forming process for shaping a desired profile of said winding sections.

13. The flexible electrical cable according to claim 1, wherein: only one strand is spirally wounded around said conductive core as a banding; said strand is a one-piece profile strand; said winding sections are formed with a Z profile as seen in a longitudinal-sectional view along said longitudinal direction; said winding sections each have an inner section and an outer section, such that in the case when the cable is bent said outer section slides over said inner section of an adjacent winding section until said support surfaces of adjacent winding sections contact and bear on one another.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) Exemplary embodiments of the invention will be explained in greater detail with reference to the drawings. Thee drawings show the following, in part by highly simplified representations:

(2) FIG. 1a a cross-sectional view of a flexible cable,

(3) FIG. 1b a longitudinal sectional view of a flexible cable, and

(4) FIG. 2 a roughly simplified representation of an electric motor-driven motor vehicle connected to a charging column for charging.

DESCRIPTION OF THE INVENTION

(5) In the drawings, parts having the same effect are represented by the same reference numerals.

(6) FIG. 1a shows a cross section through a flexible cable 2 for supplying two units that may be moved relative to one another. The cable 2 extends in a longitudinal direction 4 and has a conductive core 6. In the exemplary embodiment, the cable 2 is designed as a charging cable for electric motor-driven motor vehicles, in particular as a Mode 4 charging cable. For this purpose, the conductive core 6 has a plurality of electrically conductive elements 7; in the exemplary embodiment, these are five supply wires 8 and three control lines 10.

(7) Mode 4 generally denotes an operating mode for charging an electric motor-driven passenger car. Charging by the Mode 4 charging mode is effected by a direct current of up to 500 A, supplied to the car to be charged via the cable 2 by means of electrically conductive elements 7, and in particular by means of supply wires 10. In the exemplary embodiment, a three-wire configuration of a charging cable is shown. Three of the five supply wires 8 serve in this case as the (charging) current supply, one supply wire 8 serves as a neutral conductor and one supply wire 8 is designed as a grounding wire.

(8) The control lines 10 serve to transmit control signals, for example to start or end a charging process. Control lines 10 of this kind preferably have a cross section that is smaller by a factor of 10 to 12 than the cross section of the supply wires 8. In the exemplary embodiment, the supply wires 8 have a cross section in the range of 2 mm.sup.2 to 16 mm.sup.2. In the exemplary embodiment, the control lines 10 have a cross section in the range of 0.5 mm.sup.2 to 1 mm.sup.2. In the exemplary embodiment, the conductive elements 7 have a sheathing made of a plastic such as polyvinyl chloride (PVC).

(9) In the exemplary embodiment, the cable 2 also has an intermediate jacket 12, which is arranged peripherally around the conductive core 6 and likewise extends in the longitudinal direction 4.

(10) A reinforcing layer 14 is arranged peripherally around the intermediate jacket 12, which extends in the longitudinal direction 4 and is formed from a strand 16 wound around the conductive core 6 with winding sections 18 adjoining one another in the longitudinal direction 4 (see FIG. 1b). The reinforcing layer 14 is made of metal, in particular a ferromagnetic metal such as steel, in the exemplary embodiment. The strand 16 is a metal profile strand.

(11) The strand 16 is formed from a flat band in the exemplary embodiment, by a forming process for shaping the desired profile of the winding sections 18. The strand 16 is formed by shaping processes, for example pre-embossing or pressing to shape the desired profile.

(12) Furthermore, the cable 2 has an outer jacket 20 arranged peripherally around the reinforcing layer 18. The outer jacket 20 serves both to protect a user when handling the cable 2, for example when plugging the cable 2 into a car to be charged, and as a protective jacket for the cable against external influences, such as mechanical, thermal or other loads.

(13) In FIG. 1b, the cable 2 is shown in a simplified partial longitudinal sectional view. For reasons of simplification, the conductive elements 7 of the conductive core 6 are not shown separately.

(14) As already described, the reinforcing layer 14 arranged peripherally around the intermediate jacket 12 has a plurality of winding sections 18 that are displaceable relative to each other when the cable 2 is bent in the longitudinal direction 4. The winding sections 18 are preferably designed in one-piece form, in particular as one-piece and especially monolithic profiles; in the exemplary embodiment, they are each configured in the manner of a Z profile. Furthermore, the winding sections 18 are formed such that they overlap in the longitudinal direction 4 and abut each other to form a closed reinforcing layer 14. As a result, an electrical contact of the individual winding sections 18 with each other is achieved.

(15) In the exemplary embodiment, the winding sections 18 each have an inner section 22 and an outer section 24. Both the inner section 22 and the outer section 24, viewed in the longitudinal direction 4, have a support surface 26 at both ends.

(16) To form the reinforcing layer 18, the strand 16, which is preferably Z-shaped in cross section, is wound successively spirally around the conductive core 6, in the manner of a banding. Adjacent winding sections 18 of the strand 16 are arranged with overlap around the conductive core 6.

(17) The reinforcing layer 18, in particular the winding sections 18, serve to provide mechanical protection of the cable 2, in particular with respect to a bending fatigue strength.

(18) In other words: The reinforcing layer 14, and in particular in the exemplary embodiment, the winding sections 18 formed in the manner of a Z profile, are arranged around the conductive core 6 and thus inside the cable 2, so that they limit the bending movement of the cable 2 when the cable falls below a bending radius R, in particular a minimum bending radius.

(19) For this purpose, the winding sections 18 are displaced in the longitudinal direction when the cable 2 is bent, and the outer section 24 of a winding section 18 slides over the inner section 22 of an adjacent winding section 18. In other words, the Z profiles push into each other. As the bending radius R decreases, the winding sections 18 move further into one another until the support surfaces 26 of adjacent winding sections 18 contact and bear on one another. Overbending of the cable 2 is prevented due to the winding sections 18 bearing on one another, preventing a cable break, in particular a break of the control lines 10.

(20) Bending radius R in the exemplary embodiment refers to the radius of a circular path that at least partially describes the bent cable 2.

(21) Furthermore, the reinforcing layer 14 is due to being made in particular of a ferromagnetic metal, both as a shield against electromagnetic interference and also as protection from being driven over, for example, when a car drives over the cable 2, for example when maneuvering the car to a charging column prior to charging.

(22) To avoid lateral forces and/or displacement of the winding sections 18 perpendicular to the longitudinal direction, the support surfaces 26 have flat surfaces and are oriented perpendicular to the longitudinal direction 4. As a result, forces that may occur are distributed only in the longitudinal direction 4.

(23) FIG. 2 shows a roughly simplified representation of an electric motor-driven passenger vehicle 30 connected to a charging column 28 for charging. For this purpose, the vehicle 30 is electrically connected to the charging column by means of the cable 2. By electric motor-driven car here is generally meant a purely electric motor-driven passenger car or a passenger car that has both a motor that operates in the manner of an internal combustion engine and a motor that operates in the manner of a purely electrically operated motor. Among the latter are, for example, plug-in hybrid vehicles.

(24) In particular, in the case of a charging column 28 designed for charging in Mode 4 charging mode, the user at least connects the cable 2 irreversibly to the charging column 28. For connecting the cable 2 with the car to be charged, the cable 2 has, in the exemplary embodiment, a plug 32 at one end, and in particular has a type 2 or type 3 plug in the case of charging by the Mode 4 charging mode.

(25) Charging cables for electric or hybrid motor vehicles with electric traction motors typically have standardized charging plugs. Relevant standards on this point are currently IEC 62196-2 (type 2 and type 3 plugs), SAE J1772 or IEC 62196-2 (type 1 plug). The cable 2 designed as a charging cable is therefore provided, at least at one end, with a standardized charging plug, for example in accordance with the abovementioned or (future) comparable standards.