Shielded flat cable and methods for its manufacture

Abstract

Flat conductor (1) consisting of an outer electrical insulation (10) and at least one electrical conductor structure (20) incorporated within the insulation, wherein the conductor structure (20) consists of a stack of a plurality of thin metallic layers (21) packed one above the other, characterized in that the metallic layers (21) are incorporated into the insulation (10) as layers compacted in the thickness direction (D), wherein the flat conductor (1) has several conductor structures (20) electrically separated from one another by the insulation (10), in particular arranged side by side in the width direction (B) of the flat conductor, of which at least one, several or all, each consists of a stack of a plurality of thin metallic layers (21) packed one above the other.wherein a shielding braid (30) extending along the direction of extension is arranged around one or more conductor structures (20) and the respective insulations (10), and an outer sheath (40) is arranged around the shielding braid (30).

Description

[0001] The invention relates to a shielded flat cable in a compact design and a method for manufacturing such a shielded flat cable. Technical background

[0002] Electrical contact devices are known from the prior art, which in particular comprise a compacted section of an electrical connector, preferably an electrical conductor, for use in the medium- or high-current range or high-voltage range, as well as a method for manufacturing such an electrically conductive connection partner, e.g., for the supply and / or distribution of electrical energy. However, many of the known conductor systems have disadvantages, such as insufficient current-carrying capacity, lack of flexibility, or high manufacturing costs.

[0003] In the electrical field, particularly in the automotive sector for vehicle applications, a large number of electrical connectors or connection partners are known which serve to transmit electrical currents and voltages in the medium or high current and / or voltage range. High-voltage applications within the meaning of the present invention are defined here as voltages that, according to international standards, are no longer considered touch-safe.

[0004] In particular, such connecting cables, e.g., for the supply and / or distribution of electrical energy in warm, possibly hot, contaminated, humid, and / or chemically aggressive environments, must guarantee reliable transmission of electrical power in the short and / or long term and be able to be flexibly assembled by a cable manufacturer. Due to a wide range of applications, a large number of different connectors are known in the automotive and industrial sectors.

[0005] Such electrical cables or wiring harnesses are sometimes routed along complex geometries within the vehicle and therefore must be flexible, require little space, and withstand high mechanical and thermal stress. Flat cables offer a space-saving solution in this regard.

[0006] In the terminology of the cable and wire industry, a distinction is made between round cables and flat cables. Round cables have a substantially round or nearly round cross-section, while flat cables have a substantially flat, particularly rectangular, cross-section, where the width of the cable is significantly greater than its thickness. Flat cables within the meaning of the present invention are also those cables where the width of the cable is significantly greater than its thickness.

[0007] Another challenge is posed by the EMC requirements in automobiles. Additional shielding devices are necessary to meet the required EMC standards.

[0008] A special type of cable is the flat cable, which is known from the prior art. Various developments exist to achieve different properties and characteristics.

[0009] For example, JP 2003 - 223 817 A discloses a flat conductor which does not have rectangular conductors or conductors bounded by at least two parallel surfaces, but rather round conductors. The provided material protrusions are irregularly distributed with respect to the conductors. No thickening is formed between any two adjacent conductors. A similar design applies to the embodiment of a flat conductor according to JP H09 - 288 913 A.

[0010] From EP 1 263 000 A1, a further embodiment of a flat conductor is known, the sheath of which is extruded from special materials. A thickening formed between two flat conductors is considered an undesirable effect of the extrusion process and should be avoided if possible. Known plastics with appropriate insulating and strength properties are used for the sheath. It should be noted in general that flat conductors made of metal or appropriately selected alloys can also be present in the flat conductor with or without an additional sheath.

[0011] While established designs do contribute to the flexibility of flat cables to a certain extent, flat cables are sometimes subjected to stresses in their applications that exceed their inherent strength properties. This is particularly relevant for the section or area of ​​the flat cable where it is molded onto or attached to a connecting component. Flat cables are also used to establish contacts with moving components, such as the lighting units of copiers, or for supplying power to rotating components, for example, instruments or airbags attached to a vehicle's steering wheel, where the connected end of the flat cable must be able to move with the steering wheel's rotation.

[0012] Further prior art in the present technical field, which reflects the preamble of claim 1, is disclosed in documents WO 01 / 50 482 A1, US 3 897 187 A, DE 18 33 652 U, DE 10 2015 208 974 A1, DE 10 2004 056 866 A1 and WO 2006 / 127 723 A2.

[0013] Some braided metal flat cables are also available on the market, for example as battery or ground connections. However, these solutions are expensive to manufacture and have other disadvantages; furthermore, they are not available by the meter for cable assembly.

[0014] Furthermore, there are currently no ready-to-use solutions available, especially as cable stock (on a roll or cable drum), that are suitable for high power transmission, sufficiently flexible and bendable, cost-effective to manufacture, and meet current EMC requirements.

[0015] These tasks are solved by the combination of features according to claim 1.

[0016] According to the invention, a flat conductor with a special conceptual design is proposed, wherein the flat conductor consists of an outer electrical insulation and at least one electrical conductor structure inserted within the insulation, wherein the conductor structure consists of a stack of a plurality of thin metallic layers packed on top of each other.

[0017] In a particularly advantageous embodiment of the invention, the conductor structure is formed from at least five, preferably at least ten, layers. However, the number of layers is not limited to this. According to the invention, the at least five or at least ten layers can, of course, differ from this resulting number. In particular, it is provided that a specific orientation of the rolled, especially metallic, copper sheets is selected such that the properties of the sheets are used in a particularly suitable manner to optimize the flexibility of the flat conductor.

[0018] In a further advantageous embodiment of the invention, the respective metallic layers are designed as thin strips or bands of sheet metal extending along the entire length of the flat conductor. By using sheet metal strips and bands of the appropriate length, a flat conductor can therefore be produced in lengths of several meters, rather than simply producing short connecting elements.

[0019] In other words, this method allows for the production of semi-finished goods in the desired length, either by the meter or by the roll, so that a new type of cable, especially high-voltage cables for power transmission, is available to cable manufacturers as cut-to-length cable by the meter.

[0020] It is particularly advantageous if the individual metallic layers are made of the same material or, alternatively, of different materials. Specific properties of the flat conductor according to the invention can be achieved through suitable and clever material combinations, especially through clever packing of the stacked layers. For example, certain layers can be made of particularly conductive material, such as copper and copper alloys, while other layers are made of materials with other special specific properties, so that a large number of flat conductor variants can be produced by the selected material mix and, in particular, by the selected material thicknesses, i.e., strip thicknesses.

[0021] According to the invention, the metallic layers are incorporated into the insulation as compacted layers in the thickness direction of the flat conductor. Due to the compaction, and in particular the properties of a compacting device, specific packings and packing densities can be produced. The invention also provides that the flat conductor has several electrical conductor structures, separated from one another by the insulation and arranged side by side, particularly in the width direction of the flat conductor, of which at least one, several, or all consist of a stack of a plurality of thin metallic layers packed one above the other. In this way, a specific flat conductor can be produced.

[0022] It can be advantageously provided that the flat conductor has a greater thickness in the areas where a conductor structure is provided than in the intermediate sections between each pair of directly adjacent conductor structures made of such metallic layers, wherein the intermediate sections are in particular each designed as a flat web section. In this way, a particularly cost-effective flat conductor is obtained that is suitable for use in high-voltage applications.

[0023] According to the invention, a shielding braid extending along the direction of propagation is arranged around one or more conductor structures within the insulation. This makes it possible to create a shielded flat cable.

[0024] A further aspect of the present invention relates not only to the flat cable itself, but also to the method for manufacturing such a flat cable. The method is characterized by the following process steps: a) Manufacturing a conductor structure formed as a stack of multiple stacked thin metallic layers, in particular thin metal sheets or metal strips. b) Compacting the conductor structure before being introduced into an extruder and c) Encasing the compacted conductor structure with electrical insulation, preferably in an extruder.

[0025] In a particularly advantageous embodiment of the method according to the invention, it is provided that in step a) the metal strips are unwound from spools of a stacking unit and brought together to form a stack, in which several of the metal strips are stacked on top of each other and are positioned relative to each other by a lateral guide in order to obtain the desired conductor structure and, in particular, for the execution of step b) are then fed to a compacting unit in the stacked arrangement, whereby the compaction step is carried out.

[0026] In a particularly advantageous embodiment, the process steps take place, so to speak, in parallel in a plant technology in which the belts are guided along the production direction and the individual stations are arranged serially one after the other.

[0027] Other advantageous embodiments of the invention are characterized in the dependent claims or are described in more detail below together with the description of the preferred embodiment of the invention with reference to the figures.

[0028] They show Fig. 1 a first embodiment of the invention; Fig. 2 a second embodiment of the invention; Fig. 3 a third embodiment of the invention; Fig. 4 a fourth embodiment of the invention; Fig. 5 a fifth embodiment of the invention; Fig. 6 a sixth embodiment of the invention; Fig. 7 a seventh embodiment of the invention; Fig. 8 an eighth embodiment of the invention; Fig. 9 a ninth embodiment of the invention.

[0029] The invention will now be described in relation to the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8 to Fig. 9 explained in more detail, wherein identical reference numerals refer to identical structural and / or functional features of the invention.

[0030] In the Fig. 1, Fig. 2, Fig. 3 to Fig. Figure 4 shows different embodiments of flat cables 1, all of which have a substantially rectangular cross-section, an outer sheath 40, and electrical insulation 10 into which an electrical conductor structure 20 is inserted. A braided shield 30 is also inserted between the electrical insulation 10 and the outer sheath 40. The four embodiments differ essentially in the arrangement and shape of the geometric form and, in particular, the cross-sectional shape of the braided shield 30.

[0031] The electrical conductor structure 20 is shown as an example consisting of five layers 21, specifically of metallic layers 21 stacked on top of each other. However, any number of technically producible thin metallic layers can be packed into a stack to create the conductor structure 20.

[0032] In the exemplary embodiments according to the Fig. 5 and Fig. Figure 6 shows flat conductors 1 in which two electrical conductor structures 20 are arranged side by side in the width direction, each within an insulation 10. The electrical conductor structures 20 are similar to those in the embodiments shown in Figure 6. Fig. 1, Fig. 2, Fig. 3 to Fig. 4 from a stack of multiple thin metallic layers 21 packed one on top of the other. This configuration creates, in the lateral direction between the conductor structures 20 within the flat conductor, a so-called reinforced and double insulation formed by the insulation 10. A common braided shield 30 is arranged around the two conductor structures 20 and the respective insulations 10. The braided shield 30 is in turn surrounded by a common outer sheath 40.

[0033] In the design of the Fig. Figure 6 shows that indentations or recesses 41 are provided at the position between the two electrical conductor structures 20 surrounded by insulation along the outer sheath 40.

[0034] In the embodiment according to the Fig. 7 is a bridge cable according to the invention. This embodiment of the flat cable 1 is essentially made up of a combination of the Fig. 1, Fig. 2, Fig. 3 to Fig. 4 embodiments shown, which in turn are connected to each other via a bridge 11 as an intermediate section.

[0035] In the embodiments according to Fig. 8 and Fig. 9 The electrical conductor structures 20 are stacked one on top of the other in the thickness direction, but are electrically insulated from each other. In the embodiment according to Fig. 8 The two electrical conductor structures 20 have a common insulation 10. While in the embodiment according to Fig. As can be seen in Figure 9, each of the two conductor structures 20 forms its own insulation 10, which, however, lie flat against each other at their point of contact. A shielding braid 30 is formed within each of the two stacked electrical conductor structures 20, and an outer sheath 40 surrounds each shielding braid 30.

Claims

[1] Flat conductor (1) consisting of an outer electrical insulation (10) and at least one electrical conductor structure (20) placed inside the insulation, wherein the conductor structure (20) consists of a stack of a plurality of thin metallic layers (21) packed on top of each other, characterized by, that the metallic layers (21) are incorporated as layers compacted in the thickness direction (D) in the insulation (10), wherein the flat conductor (1) has several conductor structures (20) electrically separated from one another by the insulation (10), in particular arranged side by side in the width direction (B) of the flat conductor, of which at least one, several or all, each consists of a stack of a plurality of thin metallic layers (21) packed on top of each other, wherein a shield braid (30) formed along the extension direction is arranged around one or more conductor structures (20) and the respective insulations (10) and an outer sheath (40) around the shield braid (30). [2] Flat cable (1) according to claim 1, characterized by , that the conductor structure (20) is formed from a number of at least 5, preferably at least 10 layers (21). [3] Flat cable (1) according to claim 1 or 2, characterized by, that the respective metallic layers (21) are formed as thin strips of sheet metal extending along the direction of extension of the entire flat conductor. [4] Flat cable (1) according to any one of the preceding claims, characterized by , that the respective metallic layers (21) are formed from the same material or from different metallic materials. [5] Flat cable (1) according to any one of the preceding claims, characterized by , that the flat conductor (1) has a greater thickness in the areas where a conductor structure (20) is provided, as in the intermediate sections (11) between each two conductor structures (20) running directly next to each other, wherein the intermediate sections (11) are in particular each designed as a flat web section. [6] Method for manufacturing a flat cable (1) according to one of the preceding claims comprising the following process steps: - Forming a ladder structure (20) of a stack from a plurality of stacked thin metallic layers (21), in particular from thin metal sheets or metal strips; - Compacting the ladder structure (20) before insertion into an extruder; - Encasing the compacted conductor structure (20) with electrical insulation (10) in an extruder. [7] Method according to claim 6, characterized by , that in step a) metal strips are fed from spools of a stacking unit, in which several of the metal strips are stacked on top of each other and are positioned relative to each other by a lateral guide and in particular are fed in the stacked arrangement of a compacting unit for the performance of step b).

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