DE10357000A1 - Production process for a long watertight cable for electrical current and signals and optical signals uses heating to contact neighboring cable cores and enclose in plastic - Google Patents

Abstract

The invention relates to a longitudinally watertight cable (1) and to a method for producing a longitudinally watertight cable (1) for transmitting electrical currents and / or signals and / or optical signals having at least two conductor strands (2) each having an outer lateral surface and an inner circumferential surface having outer sheath (3), wherein a conductor strand has a wire sheath (4) with at least one core (5). For production, the conductor strands (2) are inserted into the outer jacket (3), the conductor strands (2) and the outer jacket (3) are heated by a heat source until the conductor strands (2) engage with adjacent conductor strands (2) in a first contact region ( 6) thermally connect to a conductor bundle (7) via the respective outer jacket surface in such a way that it has a self-contained, gas-, vapor- and liquid-tight plastic composite, and with a second contact region (8) fixed to the inner jacket surface of the outer jacket ( 3) abut.

Description

The The invention relates to a method for producing a longitudinally watertight Cable for transmission electric currents and / or signals and / or optical signals with at least two each having an outer circumferential surface conductor strands and an inner shell surface having outer jacket, wherein a conductor strand is a Veinummantelung with at least one Core has. The invention also relates to a after this Process manufactured cable.

In order for cables to have longitudinal water tightness, the cavities between the individual, generally circular conductor strands are filled with a filling material in the prior art. That's how it describes DE 36 40 843 A1 a cable, are provided in the elongated, partitioned by chambers, gas-filled hollow body, which fill the cavities and thus prevent penetration of water in the cable longitudinal direction. However, these hollow bodies must be prefabricated consuming. Furthermore, they can not guarantee complete longitudinal watertightness, since they can not penetrate into cavities that fall below a certain size due to their limited elasticity.

The cavities between the individual conductor strands or between the conductor strands and the inside of the outer mantle can also be filled up by at least partially swelling substances in the presence of water, as in US Pat DE 35 43 552 A1 disclosed. In this case, a carrier tape is arranged under a cable sheath, are incorporated in the recesses in water swellable materials. However, here too the carrier tape and the swellable substance must first be made available and the cable must be wrapped by the carrier tape. It would be desirable to avoid this increased expense in terms of materials and manufacture and the resulting costs.

Further These cables have the disadvantage that they after production without Loss of their longitudinal water-tight Properties can not be changed further can. In certain technical areas, such as sensor technology, But it is necessary, the cable individually to the particular application adapt. For example, sensors can be retrofitted with cables whose outer sheath therefor but cut open and their veins separated and stripped Need to become, whereby a longitudinal water tightness no longer guaranteed is. Furthermore In this case, a cable often only measures a few centimeters Length up. Therefore, it is desirable already existing, not longitudinally watertight Cable, after being customized for have been adapted to a specific application, subsequently so to be able to shape that they have a longitudinal water tightness exhibit. This should be possible only in a short section of the cable if necessary.

task It is therefore an object of the invention to provide a method place with which a longitudinally watertight Cable can be created, which even with simple production and when using the simplest means has a reliable longitudinal water tightness. It is also an object of the invention to produce a longitudinally watertight Cable allow and a longitudinally watertight Cable as such available to steep, its longitudinal water-tightness even with or after an adaptation to individual task, for example, after a sensor cabling, can be guaranteed. Furthermore, should also the sealing of only a short section of the cable are made possible.

These Task is a method for producing a longitudinal water-tight Cable of the above-mentioned Type according to the invention by the features of claim 1 and of a longitudinally watertight Cable solved with the features of claim 11.

To Inserting the conductor strands in the outer jacket become the outer jacket and the conductor strands heated. By heating the conductor strands and soften form a first contact area with adjacent conductor strands, in for example, they are flat abut each other. The thermal connection between the conductor strands comes in particular by gluing or welding the outer lateral surfaces of the adjacent conductor strands conditions. In this case, at least one outer layer of a conductor strand melted. A resulting conductor bundle, which consists of several conductor strands welded together, is heated until it is a self-contained, gas vapor and liquid-tight Plastic composite has. The parts of the outer surface of the Conductor strands, the not with adjacent conductor strands are thermally connected, forming a second contact area, the usually by heating the inner surface of the outer shell adapts and is firmly attached to this.

By contrast with the cited prior art, this method makes it possible, for example, to individually wire a sensor element via individual conductor strands or to assemble a cable of any length required for a specific individual application from existing commercially available cables. First, the conductor strands are inserted into the outer jacket. By heating, such a loose cable composite of individual conductor strands then at any point and over a be to be sealed. It should be mentioned that the conductor strands soften by the action of heat so that they are plastically deformable, so that they create a flat against each other. For example, located between individual conductor strands air is displaced by the plastic deformation of the conductor strands. In order to ensure a thermal connection between the conductor strands, they are usually heated so that the core sheath melts.

A Another embodiment of the invention provides that the entire Part of the outer surface of the Conductor strands, not over the first contact area connected to adjacent conductor strands is, forms the second contact area. This particular has the Advantage that between the outer surface of the conductor strands and the inner surface of the outer jacket no air pockets more are available. By the heat effect when heated, the individual conductor strands soften, become plastically deformable, adapt to each other in shape and thermally connect together. At the same time, this fits in thermally connecting conductor strands existing conductor bundles the inner lateral surface of the outer jacket and lies with its outer surface so preferably completely and firmly on this.

Around ensure this solid concern safely to be able to can be provided in particular that the outer jacket at least partially from a pre-stretched shrink tubing section made of a plastic, in particular from the thermoelastic plastic PTFE or Plastic PVDF is formed, and shrunk by heating on the conductor strands becomes. This guarantees, on the one hand, that the inner circumferential surface of the outer shell the conductor bundle tightly encloses, which thus firmly abuts against the inner circumferential surface of the outer shell.

To the others are due to the radial contraction of the outer shell due to the heating, the individual conductor strands pressed together. hereby the emergence of the thermal connection between the conductor strands becomes clear favored. The one of contraction of the outer shell caused radial pressure on the conductor strands also ensures for this, that the conductor strands after softening by heating deform, join each other adjust and lie flat against each other in the first contact area. simultaneously Adjusts the resulting conductor bundles with its outer shape to the inner lateral surface of the outer jacket at. Air that may be between the individual conductor strands, is displaced. One Another advantage of using a heat-shrinkable tube is that by applying an exclusively radial and uniform pressure no powers act on the wires, which the veins of the conductor strands within of the resulting conductor bundle could shift what else might happen a short circuit single veins would result.

The Use of a shrink tubing section has in particular one Advantage if a cable over a bigger distance with the method according to the invention to be sealed. For example, if a heat source moves relative to the cable or vice versa, then the outer shell pulls itself radially together, the air becomes in intermediate spaces displaced by the softening and pressed together by the heating conductor strands. In front the area in which the loose composite of conductor strands and outer sheath according to the method of the invention begins to form a self-contained plastic composite is the air is so effectively driven.

At this point should be mentioned that meant by a shrink tube section here only is that a hose-like outer sheath are used should, which has the property to contract radially when heated and thus the conductor strands to press each other can. It does not matter if such an outer jacket is referred to in the trade as a shrink tube.

In a preferred embodiment of the method according to the invention this is the outer surface of the Conductor strand-forming material made of a thermoplastic material, in particular of TPE or the fluorine-containing plastics PFA, MFA or FEP made. These materials have favorable thermoplastic properties and are suitable in a particularly advantageous manner for the process desired thermal connection.

It can be provided in particular that the outer surface of the Ladder strand is formed by the Aderummantelung. In such a Case, the material of the core sheath so also forms the outer surface of the Conductor lane. So can also simply isolated, commercial Cable can be easily used as a conductor strand.

In the context of the method according to the invention can also be provided that the outer sheath and / or the Aderummantelung is made multi-layered. A multi-layered outer sheath may be due to the fact that it has an inner layer of a material which is particularly suitable for entering into a thermal connection with the conductor strands or the conductor bundle, while an outer layer of a shrink tubing gebil det and ensures the aforementioned procedural advantages. Similarly, the core sheath may also have an outer layer, which is particularly suitable for the thermal bonding with the inner circumferential surface of the outer shell.

For the presence a multi-layeredness of the outer shell is alone crucial that the cable after performing the method according to the invention has an outer jacket, which can be regarded as multi-layered. Also as multi-layered viewed from the outer mantle and thus belonging to the invention claimed when the individual layers of the outer shell before use the method according to the invention are not interconnected. So before heating For example, means such as a separate sealant in the form of a tubular Mantels, a powder, a paste or granules and / or a steel mesh is placed around the conductor strands for shielding purposes be, which in turn from an outer layer of the outer shell be enclosed. Such a sealant is then like the outer surface of the Ladder strand-forming material preferably made of a thermoplastic Plastic, in particular of TPE or of one of the fluorine-containing Thermoplastics PFA, MFA or FEP, manufactured.

A alternative variant of the method according to the invention provides that the inner lateral surface of the outer jacket and the outer surface of the conductor strands upon heating in the second contact region thermally with each other connect, so that the self-contained, gas, vapor and liquid-tight Plastic composite extends to the outer jacket. For special Requirements for the tightness properties of the cable is so guarantees that the self-contained plastic composite of the conductor bundle over the second contact region also extends to the outer jacket, so that the possibility the occurrence of unwanted leaks between conductor bundles and outer sheath is further reduced.

at the method according to the invention is also desirable that the softening temperature of the thermoplastic, the outer surface of the Conductor strand is lower than the softening temperature the plastic of the shrink tube section. This can be reliably secured be that the desired thermal connection between adjacent conductor strands in the first contact area or - if desired - the thermal Connection between the inner surface of the outer shell and the outer surface of the conductor strands in the second contact area comes about without the material the outer coat over his Melting point beyond the temperature at which the plastic is thermally stable is, needs to be heated. The ladder coats can therefore melt and connect, with the outer jacket the melt is safely wrapped, without the risk that it melts itself. In special cases can for the heating of the loose cable assembly also be provided that that the conductor strands forming material melts only in one edge area. hereby There can be a risk of individual veins forming inside the vein Move ladder line, be further reduced.

Further can be provided in a further advantageous embodiment, that between the wire sheathing and the wire surrounding a vein Film, in particular a polyimide film, is arranged. The polyimide film As such, it has the task of a good flexibility of the cable to ensure, in which it shifts between the vein sheath and the vein shifts allows, how they can arise through the different bending radii. at Plastics, which also bond with metals, thus becomes, for example avoided that forces from the self-contained plastic composite on the wire, the For example, made of a copper alloy is transmitted can be.

The inventive method can over it characterized in that the heat source is a hot air source, a radiation source or a contact heater. Depending on requirements To the procedure, a certain heat source is to be preferred. So would become during manual execution about a hot air blower due to offer easy handling and universal usability.

Further Features and advantages of the invention will become apparent from the dependent claims and from the following description of preferred embodiments based on the drawings.

In the drawings shows:

1 a schematic representation of a cable according to the invention,

2a two conductor strands, each having a conductor sheath with two cores, within an outer sheath before carrying out the intended method (section AA),

2 B a cross-section of the cable according to 2a after carrying out the process according to the invention (section BB),

3a three conductor strands, each having a core sheath with a core inside half of a multilayer outer shell having a sealant on the inside, before carrying out the method according to the invention (section AA), and

3b a cross-section of the cable according to 3a after carrying out the process according to the invention (section BB).

1 shows a sketchy representation of a cable according to the invention 1 , The cable 1 has two conductor strands 2 on, which in this case of one veinummantelung 4 with a vein 5 are formed. The conductor strands 2 are inside an outer shell 3 arranged. The outer jacket 3 is formed by a shrink tube. The method according to the invention is here purely exemplary in a middle region of the cable 1 been applied. Of course, this can also be done over the entire length or at different points of the cable 1 be performed.

The 2a and 3a each show a possible cross section of a cable 1 on average AA. The cut is exemplary here in 1 hinted without the 2a or 3a actually in 1 illustrated cable 1 correspond. The same applies to the 2 B and 3b in terms of in 1 indicated section BB.

2a respectively. 2 B show a possible embodiment of the cable according to the invention before or after application of the method according to the invention. In 2a shows the cable 1 two conductor strands 2 on, each of a veinmantel 4 and two wires 5 are formed. The from the outer jacket 3 surrounded conductor strands 2 do not lie flat against each other. The outer jacket 3 and the conductor strands 2 form a loose cable composite. By heating, the consisting of a shrink tubing outer sheath pulls 3 together. At the same time, the entire cable assembly and the outer jacket heats up 3 and the conductor strands 2 soften or melt. Corresponding 2 B are caused by the contracting outer shell 3 applied radial force the adjacent conductor strands 2 in a first contact area 6 pressed against each other and thermally connect with each other due to the softened material to a conductor bundle 7 , which has a self-contained gas, vapor and liquid-tight area. With a second contact area 8th lie the ladder length 2 firmly on an inner circumferential surface of the outer shell 3 at. In the in 2 B illustrated case is the outer jacket 3 single-layered. Depending on the combination of materials, the conductor strands can 2 over the inner circumferential surface of the outer shell 3 connect thermally with this, so that the self-contained plastic composite on the conductor bundle 7 out on the outer jacket 3 extends. On the need for such a connection between outer jacket 3 and conductor bundles 7 decides the particular application.

The 3a and 3b show according to the scheme of 2a and 2 B another variant of the invention. Here are three conductor strands 2 inside the outer jacket 3 arranged, each one veinummantelung 4 with one vein each 5 exhibit. The outer jacket 3 is here, however, executed in multiple layers. Its inner circumferential surface is of a sealant 9 educated. By heating, the multilayer outer sheath shrinks here 3 , whose outer layer is formed by a shrink tube, on the conductor strands 2 on. The conductor strands 2 , be in the first contact area 6 pressed together and thermally bond together, making them a conductor bundle 7 form, which has a self-contained plastic composite. With the second contact area 8th lie the conductor strands 2 firmly on the inner circumferential surface of the outer shell 3 at. Unlike the 2 B and the single-layer outer jacket 3 joins in 3b but the inner surface of the outer shell 3 with the conductor strands over the sealant 9 ,

A sealant 9 can also be advantageous if the conductor bundle 7 about to be surrounded by a steel mesh for shielding. With standard cables, this can lead to liquids in the spaces between the outer sheath 3 and the conductor bundle 7 for example, can pass through capillary action. A sealant 9 however, that melts during heating and preferably can also bond with metal, the steel braid will securely enclose and in the outer jacket 3 embed.

In 3a respectively. 3b is also a difference of the method according to the invention over a simple encapsulation of the conductor strands 2 clear with a thermoplastic. While in an encapsulation, one with the sealant 9 comparable thermoplastic around the outer shape of the conductor strands 2 sets and adapts to this, the conductor strands deform in the inventive method 2 in the first contact area and connect with each other.

1

Longitudinally watertight electric wire

2

conductor lane

3

outer sheath

4

wire insulation

5

Vein

6

first contact area

7

conductor bundle

8th

second contact area

9

sealant

Claims (19)

Method for producing a longitudinally watertight cable ( 1 ) for transmitting electrical currents and / or signals and / or optical signals having at least two conductor strands each having an outer lateral surface ( 2 ) and an inner shell surface having an outer shell ( 3 ), wherein a conductor strand is a core coating ( 4 ) with at least one core ( 5 ), characterized by the steps of: • inserting the conductor strands ( 2 ) in the outer jacket ( 3 ), • heating the conductor strands ( 2 ) and the outer jacket ( 3 ) by a heat source until the conductor strands ( 2 ) with adjacent conductor strands ( 2 ) in a first contact area ( 6 ) over the respective outer lateral surface thermally to a conductor bundle ( 7 ) such that it has a self-contained, gas, vapor and liquid-tight plastic composite, and with a second contact area ( 8th ) fixed to the inner circumferential surface of the outer shell ( 3 ) issue. A method according to claim 1, characterized in that the entire part of the outer circumferential surface of the conductor strands ( 2 ) that does not have the first contact area ( 6 ) with adjacent conductor strands ( 2 ), the second contact area ( 8th ). Method according to claim 1 or 2, characterized in that the outer jacket ( 3 ) is formed at least partially by a pre-stretched heat-shrinkable tube section of a plastic, in particular of the thermoelast PTFE or of PVDF, and by the heating on the conductor strands ( 2 ) is shrunk. Method according to one of claims 1 to 3, characterized in that the outer surface of the conductor strands ( 2 ) is made of a thermoplastic material, in particular made of TPE or the fluorine-containing plastics PFA, MFA or FEP. Method according to one of the preceding claims, characterized in that the core sheathing ( 4 ) is multi-layered. Method according to one of the preceding claims, characterized in that the outer jacket ( 3 ) is multi-layered. Method according to one of the preceding claims, characterized in that the inner circumferential surface of the outer jacket ( 3 ) and the outer surface of the conductor strands ( 2 ) when heated in the second contact area ( 8th ) thermally bond together so that the self-contained, gas, vapor and liquid-tight plastic composite on the outer shell ( 3 ). Method according to one of the preceding claims, characterized in that the softening temperature of the thermoplastic material, the outer surface of the conductor strands ( 2 ) is lower than the softening temperature of the plastic of the outer shell ( 3 ). Method according to one of the preceding claims, characterized in that between the wire sheath ( 4 ) and the wire ( 5 ) one the vein ( 5 ) surrounding film, in particular a polyimide film, is arranged. Method according to one of the preceding claims, characterized characterized in that the heat source a hot air source, a radiation source or a contact heater. Longitudinally watertight cable ( 1 ) for transmitting electrical currents and / or signals and / or optical signals having at least two conductor strands each having an outer lateral surface ( 2 ) and an inner shell surface having an outer shell ( 3 ), wherein a conductor strand ( 2 ) a core coating ( 4 ) with at least one core ( 5 ), characterized in that the conductor strands ( 2 ) with adjacent conductor strands ( 2 ) in a first contact area ( 6 ) over the respective outer lateral surface thermally to a conductor bundle ( 7 ) so that it forms a self-contained, gas, vapor and liquid-tight plastic composite, and with a second contact area ( 8th ) fixed to the inner circumferential surface of the outer shell ( 3 ) issue. Cable according to claim 11, characterized in that the entire part of the outer surface of the conductor strands ( 2 ) that does not have the first contact area ( 6 ) with adjacent conductor strands ( 2 ), the second contact area ( 8th ). Cable according to claim 11 or 12, characterized in that the outer jacket ( 3 ) at least partially from a pre-stretched and one on the conductor strands ( 2 ) is formed by shrinking heat shrinkable tube section made of a plastic, in particular from the thermal load PTFE or PVDF. Cable according to one of claims 11 to 13, characterized in that the outer surface of the conductor strands ( 2 ) forming material from a thermoplastic material, in particular TPE or the fluorine-containing plastics PFA, MFA, or FEP is made. Cable according to one of claims 11 to 14, characterized in that the core sheathing ( 4 ) is multi-layered. Cable according to one of claims 11 to 15, characterized in that the outer jacket ( 3 ) is multi-layered. Cable according to one of claims 11 to 16, characterized in that the inner circumferential surface of the outer jacket ( 3 ) and the outer surface of the conductor strands ( 2 ) are thermally connected to one another by heating in the second contact region ($) and the self-contained, gas-, vapor- and liquid-tight plastic composite adheres to the outer jacket ( 3 ). Cable according to one of claims 11 to 17, characterized in that the softening temperature of the thermoplastic material, the outer surface of the conductor strands ( 2 ), is lower than the softening temperature of the thermoelastic plastic of the outer shell ( 3 ). Cable according to one of claims 11 to 18, characterized in that between the wire sheath ( 4 ) and the wire ( 5 ) one the vein ( 5 ) surrounding film, in particular a polyimide film, is arranged.