DE102014200874B4 - Method and system for the production of a pre-assembled cable of a predetermined length - Google Patents

Abstract

A method for producing a prefabricated cable (1) of a predetermined length with at least one electrically conductive conductor which is sheathed by an insulating material (5) and carries a contact component (3) at at least one end, the contact component (3) being attached to an uninsulated endless conductor ( 2) is attached to a predetermined point and then subsequently the insulation material (5) is continuously applied to the endless conductor (2) and the contact component (3) and, after the insulation material (5) has been applied, the cable (1) is attached to the contact component (3) is cut to length.

Description

The invention relates to a method for producing a prefabricated cable of a predetermined length, which consists of an electrically conductive conductor, at the ends of which a contact component is attached and wherein the prefabricated cable is sheathed by an insulating material. The invention also relates to a system for producing such a cable.

Today it is customary to manufacture assembled electrical cables by making the electrically conductive conductor as an endless cable mostly from copper, more rarely from aluminum, then sheathing it with an insulation material and then winding it on so-called cable reels.

The sheathing with an insulation material is produced either by extrusion of the insulation material or by a dipping process. Mainly thermoplastic materials such as PVC, polyethylene, polypropylene or polyurethane or cross-linking materials based on silicone are used as insulation materials.

The electrical conductor of such lines is usually not a solid material, but is made up of individual fine strands. These strands are made from a raw material, the so-called coils, using two cold drawing processes. This manufacturing process changes the crystalline structure of the individual strands, so that it has to be normalized again through a thermal process. The surfaces of the individual strands also oxidize, which is a major problem with aluminum.

The cable reels produced in this way are then delivered to a second manufacturer, the assembly company, who cuts the cables to the desired length of the customer and then applies the required contact components to the two free ends after the insulation layer has been removed beforehand.

The contact components for lines in the automotive industry are attached either by crimping, by soldering or welding, the latter method usually being used for cables which are designed for high currents and / or voltages. As a seal against environmental influences, a shrink tube is then often applied to the transition area from the insulation material to the contact component.

In this case, it is not ensured that the connection point between the conductor and the contact component is completely freed from the insulation material on the one hand and completely sealed off from environmental influences on the other. If corrosion occurs here during later operation, the contact resistance changes, which can lead to incorrect control of the connected electrical consumer and / or to undesirably strong heating of the contact point.

In addition, heat is reintroduced into the line material during soldering or welding, which changes its crystalline structure and thus its electrical resistance.

Due to the above-mentioned oxidation, safe crimping is no longer possible with aluminum conductors. If soldering or welding is used to fasten the contact components, the oxidation layer must first be broken up.

The document US 6 176 716 B1 According to an interchangeable electrical connector includes a connector body and an adapter body. The connector body contains electrical contact means, such as a banana plug tip, for snapping into an electrical connection. The connector body includes a conical portion and a threaded portion that is coaxial with the conical portion. The adapter body includes a tapered portion that is shaped for cooperative engagement with the tapered portion of the connector body and a threaded portion that is coaxial with the tapered portion of the adapter body. The threaded portion of the adapter body is adapted for cooperative engagement with the threaded portion of the connector body such that cooperative rotation of the connector body relative to the adapter body pulls the tapered portion of the connector body into engagement with the tapered portion of the adapter body. Due to the wedge effect of the two conical sections, the connector body is brought into frictional engagement with the adapter body.

From the document WO 81/00 329 A1 there is known a pair of terminals which have the same shape or different shapes and different dimensions, are arranged opposite to each other and are connected to each other at their tops to form a terminal coupling, and a plurality of such terminal couplings are arranged in the order of their use. In this way, the connecting wires are automatically coupled and arranged in the order in which they were manufactured, without the terminals and coupling terminals being selected using specially made couplers. In wiring, therefore, each connecting wire required one after the other can be provided in the order of use when the connecting wire is drawn from a take-up drum or the like on which the Connection wires are wound up. The coupling part between the terminals is then cut off. The connections are suitable for wire clamps that are necessary for such connecting wires that are intended for a sequential connection between devices on a switchboard or the like.

The document DE 19 63 307 A relates to an automatic machine for processing connecting wires. The machine combines a storage unit, an unwinding unit, a marking unit, a length measuring, cutting and stripping unit, a transfer and feeding unit, a positioning device and guiding, holding and ejecting elements. The unwinding speed of the unwinding unit can be regulated by means of an electrical element, which can be adjusted as a function of the tensile force of the wire on a balancing arm, which arm interacts with the electrical element. The marking unit has pressure elements which are controlled in such a way that each length of wire is provided with a marking at least once. The length measuring, cutting and stripping unit has a length measuring element with means which start the cutting and stripping cycle and the marking cycle after a predetermined length of wire has been measured. The transfer and feed unit has a conveyor belt with a constant, adjustable speed. The installation device has means for adjustable braking of the wire as a function of the speed of the conveyor belt and the mass of the wire. The guiding, holding and ejecting elements cooperate through a position control device according to a predetermined cycle. The control device also directly or indirectly makes the measuring-cutting-stripping unit and the next following insertion unit effective, each unit being provided with means for locking the machine in the event of a malfunction.

The object of the present invention is to improve a method and a system for producing electrical cables, in particular for use in electrical drives in motor vehicles.

According to the invention, this object is achieved by the features of the first, third and fifth claims. The subclaims describe advantageous developments of the invention.

The invention is based on the knowledge that the contact components are first applied to the line and only then the insulation layer and only then the cable is cut to length. This ensures that the connection point between the contact components and the line is protected against environmental influences, in particular moisture or water. Furthermore, the above-mentioned impurities due to insulation material that has not been completely removed at the connection point are avoided.

This has the advantage that the contact resistance and also the heating at the connection point are prevented.

If the contact components are attached by soldering or welding, the thermal process to normalize the structure of the strands can only take place after the contact components have been attached, so that the soldering or welding of the contact components does not have a negative impact on the structure of the strands.

A particularly simple production of the cable according to the invention results from the development according to claim 2.

Complex cleaning of the jacketed contact components is avoided by the development according to claim 4. Here, the protective cover can be designed in such a way that it can simply be cut open or torn open.

A contact component in the context of the invention does not have to be understood to mean a contact component that is ready for connection. Rather, it can also be a metallic intermediate piece to which the actual contact component, for example a cable lug or a cable eyelet, is fastened after the part of the contact component fastened to the line has been cut to length and exposed.

Claim 5 describes a system suitable for carrying out the method.

The development according to claim 6 describes an advantageous arrangement of the contact components in the system. This considerably simplifies the later cutting of the cable.

The connection of mutually facing contact components, as proposed in claim 7, facilitates the continuous passage of the cable during the application of the insulation material, be it by extrusion or by immersion baths.

The development of the invention according to claim 8 simplifies the subsequent exposure of the contact components. Here, the protective cover can be applied as a type of shrink tube and fixed by the action of heat, or it is applied by extrusion.

As a result of the production method according to the invention, known contact components which are actually only suitable for rigid conductors can also be used in flexible conductors.

The invention is explained in more detail below using a preferred exemplary embodiment.

• 1: eine schematisierte Ansicht des Kabels mit Kontaktbauteilen nach der Erfindung;
• 2a, b zwei Ausführungsbeispiele der Kontaktbauteile;
• 3 ein Kontaktbauteil mit einem Formgegenstück;
• 4 eine schematisierte Anordnung einer erfindungsgemäßen Anlage;
• 5 ein schematisierter Aufbau eines Magazins für Kontaktbauteile;
• 6 eine schematisierte Anordnung zum Aufbringen der Isolations schicht mittels Extrusion.

It represent

• 1 : a schematic view of the cable with contact components according to the invention;
• 2a, b two embodiments of the contact components;
• 3 a contact component with a shaped counterpart;
• 4th a schematic arrangement of a system according to the invention;
• 5 a schematic structure of a magazine for contact components;
• 6th a schematic arrangement for applying the insulation layer by means of extrusion.

In 1 Figure 3 is a schematic view of a completed cable 1 shown. It consists of an electrical conductor that can be solid or made of stranded wires. There is a contact component at each of its two ends 3 appropriate. Areas 4th the contact components 3 as well as that between the contact components 3 Horizontal conductors are covered with an insulation layer 5 encased.

Two preferred versions of particularly advantageous contact components 3 show the 2a and 2 B .

In both embodiments, the contact components are 3 Sleeve-shaped with a central through opening 6th . This allows the ladder to be an endless ladder 2 through the individual contact components 3 be pushed through, as will be explained below.

The contact components 3 consist of a contact zone 7th and a sealing zone 8th .

In 2a is the contact zone 7th unprofiled and can serve, for example, to accommodate a contact socket, not shown in detail. However, it can also be introduced directly into a plug-in coupling or into a housing in order to then be inserted into a receptacle. Several such cables can also be attached next to one another in a housing.

The sealing zone 8th is conical and has an annular groove 9 on. It is used to seal the insulation layer tightly 5 that up to this ring groove 9 the area 4th the sealing zone 8th encloses.

In 2 B is the contact zone 7th designed directly as a contact to a plug, component or a plug-in coupling.

In 3 becomes the contact zone 7th out 2 B used, but here is a connector 10 attached, which is used to connect a further contact part. A known cable lug or a cable eyelet, such as are generally used in automobile construction, can serve as the contact part. This configuration has the advantage that only one contact component has to be used, regardless of the type of contact desired later. Against this, when using the execution after 2a already when equipping the conductor 2 it is clear what the final contact should look like.

The embodiment according to 4th until 6th shows the possible structure of a system for producing the cable according to the invention 1 .

The production plant essentially consists of two or more cable drums 10 , 10 ' made with an endless electrically conductive conductor 2 are equipped.

The endless conductor is made from a cable drum 2 pulled off and put to a magazine 11 guided. In the magazine 11 there are contact components 3 , how to 5 will be explained in more detail.

According to the magazine 11 becomes the one with the contact components 3 equipped endless ladder 2 to a splice station 12th guided. This serves the end of the endless ladder 2 from the cable drum 10 with the beginning of one of the cable drum 10 ' withdrawn new endless conductor 2 to connect when the cable drum 10 is settled.

It can make sense to use every cable drum 10 , 10 ' its own magazine 11 , 11 ' assign and cable drum 10 , 10 ' with associated magazine 11 , 11 ' changeable in front of the splicing station 12th to arrange.

After the splice station 12th becomes the endless ladder 2 to a fastening station 13th , here in the example a crimping station, in which the previously only loosely attached contact components 3 on the perimeter of the endless ladder 2 be attached at predefined locations. Instead of the crimping station, a soldering or welding station can also be provided if the contact components 3 on the endless ladder 2 to be soldered or welded on.

Then the endless conductor equipped with the contact components becomes 2 over a compensation section 14th to a coating station 15th out, in which it is completely covered with insulation material. The compensation stretch 14th guarantees a continuous passage of the endless ladder 2 through the coating station 15th , even if cyclical operation should be necessary in the previous stations. The coating station 15th consists in this example of an extruder.

After leaving the coating station 15th the insulated endless conductor runs 2 through a cooling and heating section 16 to solidify the insulation.

In 4th no longer shown, there is then a separating station in which the endless conductor 2 between two contact components 3 is cut to length so that the finished cable is created. In addition, the insulating material must then be on the contact zone 7th of the contact component 3 removed.

In 5 is the magazine 11 shown in detail. The contact components are in it 3 with their free ends arranged alternately opposite one another, ie a contact zone 7th a first contact component 3 is the contact zone 7th of the second contact component 3 across from. At the free sealing zone 8th of the second contact component 3 the sealing zone closes 8th of the third contact component 3 to etc.

The contact components 3 are constructed in the shape of a sleeve so that they can be placed on the endless ladder 2 can be threaded. The individual contact components 3 , between which the finished cable is later separated, be connected to one another by connecting webs (not shown). These connecting webs are then used later when the endless conductor is cut to length 2 also removed.

Furthermore, the contact zones 7th of the individual contact components 3 be covered with a protective cover to protect it in the subsequent manufacturing process. This protective cover must then be removed from the finished cable later.

After the contact components 3 in the magazine 11 on the endless ladder 2 have been threaded, they are in the crimping station 13th at their predefined location on the perimeter of the endless ladder 2 attached.

In 6th is the application of the insulation in the coating station 15th explained in more detail with the help of an extruder.

Because due to the already existing contact components 3 the extruder head 15 ' If the insulation material cannot apply continuously, it must be ensured that no insulation material can escape from the areas that are not to be coated at the necessary extrusion pressures.

At low extrusion pressures, the inlet of the endless conductor 2 in the coating station 15th from above and the outlet downwards. The pulling movement and the force of gravity can then allow the insulation material to exit on the inlet side of the coating station 15th prevent.

As a rule, however, such low extrusion pressures with thicker endless ladders 2 is not sufficient, a pressure equalization and / or a seal between the injection point must be 17th of the extrusion head 15 ' and the inlet of the endless ladder 2 in the coating station 15th respectively.

The coating station 15th a feed line 18th on whose inner diameter to the outer diameter of the contact components 3 is matched. This also determines the thickness of the insulation layer.

To prevent insulation material from moving against the conveying direction 19th of the endless ladder 2 from the extrusion head 15 ' exits, at least one pressure compensation system is provided, which consists of a pressure vessel / pressure generator 20th , the pressure distribution line 21 and the connecting lines 21a , 21b , 21c consists. The connecting lines 21a and 21b open into the cavity 22nd coming from the supply line 18th and the not yet overmolded conductor section is formed, which is located immediately in front of the extrusion head 15 ' is located. The connecting line 21c opens directly in front of the injection point 17th of the extrusion head 15 ' . So there is the same pressure everywhere in this area. A pressure control (not shown) ensures the desired pressure level.

Since the length of the finished cable can be different, the distance between the connecting lines must be 21a and 21b be set to the smallest cable length or made adjustable.

If this pressure equalization is not sufficient, a system of at least two-shell sealing sleeves can also be used 23 can be provided, as additionally in 6th is shown. A two-part conveyor system is used for this purpose 24 , 25th provided with the individual shell halves of the sealing sleeves 23 is filled.

The shell halves are controlled at the beginning of the cavity 22nd , where also the connection line 21a flows out. Here the two shell halves become a sealing sleeve 23 composed

The sealing sleeves are pulled off and divided 23 in front of the extrusion head 15 ' . After the withdrawal, the shell halves are conveyed back in a circle.

Alternatively, directly in front of the extrusion head 15 ' a lamella construction, similar to a shutter of a photo camera, with a circular opening can be provided, which is when passing the contact components 3 opens and then back to the diameter of the endless conductor 2 closes.

Claims (8)

A method for producing a prefabricated cable (1) of a predetermined length with at least one electrically conductive conductor which is sheathed by an insulating material (5) and carries a contact component (3) at at least one end, the contact component (3) being attached to an uninsulated endless conductor ( 2) is attached to a predetermined point and then subsequently the insulation material (5) is continuously applied to the endless conductor (2) and the contact component (3) and, after the insulation material (5) has been applied, the cable (1) is attached to the contact component (3) is cut to length. Procedure according to Claim 1 , characterized in that the uninsulated endless conductor (2) is guided through sleeve-shaped contact components (3), which in pairs with their free contact zones (7) are opposite one another, that the contact components (3) are then attached to the predetermined points on the endless conductor (2) and then the endless conductor (2) equipped in this way is continuously coated with the insulation material (5) and then cut to length between two opposing contact components (3). A method for producing a prefabricated cable (1) of a predetermined length with at least one electrically conductive conductor which is sheathed by an insulating material (5) and is equipped at at least one end with a contact component (3), an uninsulated endless conductor (2) in front of the Attaching the contact component (3) is cut to the desired length, characterized in that facing contact zones (7) of two contact components (3) are connected to one another in pairs and then the cut-to-length endless conductors (2) together with the contact components (3) attached to them. continuously coated with the insulation material (5) and then severed at the connection point of the contact components (3). Method according to one of the preceding claims, characterized in that the two mutually facing contact zones (7) of the contact components (3) are protected by a protective cover before being sheathed with the insulating material (5). System for carrying out the method according to one of the preceding claims, consisting of a storage drum (10, 10 ') with uninsulated endless conductor (2), a coating station (15) for applying an insulating material (5) and a fastening station (15) arranged in front of the coating station (15). 13) for the contact components (3) on the endless conductor (2), characterized in that the coating station (15) is followed by a separating station at which the endless conductor (2) so equipped and continuously coated with the insulation material between two opposing contact components (3) is cut to length. Plant after Claim 5 , characterized in that there is a magazine (11) in front of the fastening station (13) in which the individual contact components (3) are kept ready, alternately with their contact zone (7) and their sealing zone (8, 9) opposite one another . Plant after Claim 5 or 6th , characterized in that two mutually facing contact components (3) are connected to one another via their contact zones (7). Plant according to one of the Claims 5 until 7th , characterized in that a station for attaching protective covers is present before the coating station (15) and after the fastening station (13).

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