DE2308545B2 - Process for the production of electrical cables or lines in a bundle structure - Google Patents

Description

The invention relates to a multi-stage stranding process for electrical cables and lines in a bundle structure, as described in the preamble of the claim.

For stranding electrical cables, especially for stranding communication cables and lines, In recent times, methods and devices are used with which stranding elements in successive Longitudinal sections alternating with a left twist (S twist) and a right twist (Z twist) be stranded. All stranding of this type, known as "SZ stranding", has the advantage of that the stranding elements to be stranded can run off stationary drainage racks and that the further processing of the stranding units stranded from the stranding elements SZ in the same operation can be. For example, in the manufacture of communication cables, cores become star fours SZ-stranded and several such star quads stranded into a basic bundle in the same operation. The basic bundle stranding can also be done by an SZ stranding process however, a continuous stranding process can also be considered. In the further course of the production of the Cable core of the communication cable, several basic bundles become one main bundle! and if necessary several main bundles stranded to form a cable core. The stranding of the basic bundle to form the main bundle and the Stranding of several main bundles to form the cable core usually takes place in a continuous manner Stranding process, d. H. usually with the help of a continuously rotating take-up and take-up device.

SZ stranding processes are also common, in which SZ stranding units or SZ stranding groups come together with twisting that is different in sections or changing in sections. An SZ stranding process with different twisting in sections is for example in DE-AS 16 65831 described, while an SZ-Verseil proceed with constantly changing twist from DE-AS 17 65 452 is known.

to choose. For example, when stranding The following twists or lay lengths are common for communication cables in bundles:

For stranding cores in pairs or twists of star fours

d = 6- 20-2jr / m.

d. H. Lay lengths of 5-15 cm; for stranding pairs or star fours to form a basic bundle Drilling from

d = 2 2 n / m,

for the stranding of basic bundles to form the main bundle> ") a twist of

</ = 1 - l, 5-2jr / m

and a twist for stranding main bundles to form a cable core

^m d = 0.6-2jr / m.

When manufacturing electrical cables and wires in bundles through a multi-stage stranding process, whose first stranding stage is carried out by an SZ

i) treatment is marked, indicate the manufactured SZ-stranded stranding units for themselves and also in the finished cable core reversal points of the twisting direction on. In the area of these reversal points, the stranding elements are only inadequately stranded or not stranded at all.

The respective stranding element or the respective stranding unit therefore has unfavorable bending properties at these points, This can lead to wire breaks at an early stage in the case of frequently moving lines or cables. It is also possible that wire pairs are connected to these

4> unswisted or insufficiently stranded places at

Bending of the cable or pipe

and that thereby the electrical symmetry of the

Wire pair is deteriorated. The invention is therefore based on the object

^r ) <) to improve the flexibility in the area of the reversal points of the twisting direction resulting from SZ stranding through a further development of the method mentioned at the beginning.

This object is then achieved by a method as described in the characterizing part of the patent claim is described in detail.

In this stranding process, the intended choice of twists in the successive

M) Stranding ensures that by superimposing the twisting of the SZ stranding process (s) with the twisting (s) of the continuous (s) In the stranding process in the finished cable core, reversals of the twisting direction no longer occur.

The superimposition of the SZ twists and the continuous twists results in such twists The level shift of the still existing SZ twist takes place so that the reversal points of the twist

direction in change points of the twist constant twist direction. So for example with one from basic bundles established communication cable is the twist of the in of the first stranding stage for stranding cores to form star fours, SZ stranding is selected in such a way that that in the subsequent superimposition of a continuous twist by stranding the star quads to the basic bundle and through the further stranding of several basic bundles to form the cable core The sum of the continuous twists is greater than the SZ twist. So here it is It is necessary to deviate from the usual stranding scheme, in which the smaller the stranding level Drillings are provided. For the invention it is therefore important to use the SZ drill or as the Select the sum of the subsequent continuous twists. In this way, the The area of the originally existing reversal points in the direction of twisting has good bending properties manufactured electrical cable or wire.

Several exemplary embodiments of the invention are explained in more detail below

In the production of bundles made up of pairs in a two-stage stranding process in which the cores are SZ-stranded in parallel work stages and the pairs produced in this way directly are then continuously stranded into a bundle in the same operation, for example the following conditions exist:

The twist of the SZ stranded pairs is

d = ± 5-2 π / m.

Bundle of twists made by

eh = d _f + db = + 8-2 π / m
up to

dg = di + di = - 8 · 2 ίτ / ιη

rich, d. h, also in this case occur at intervals again reversals of the twisting direction and thus insufficient or non-stranded sections.

When using the method designed according to the invention, on the other hand, the following conditions arise:

Veins become pairs with twisting that changes direction in sections

dw or du = ± 2

The continuous twist when stranding the Jj core pairs to form a bundle is

d ₂ = + 2-2 π / m.

After going through this two-stage stranding process, the pairs of wires are superimposed on the in The twists obtained from the two twisting stages have the following final twists:

d \ = + 7 ■ 2 π / m,
b _t " 3-2 π / m.

There are therefore reversal points in the finished basic bundle the direction of twist, d. H. each pair of wires is not or only in a certain area at intervals insufficiently stranded.

Similar relationships occur if there is also an SZ stranding for -V5 in the second stranding stage Application comes. For example, there are five wire pairs with the SZ twists

d \ = + 5 ■ 2 π / m
and

di = - 5 * 2 π / m

SZ-stranded with the following twists to form a bundle:

dt = +32 π / m
and

di = -3-2 π / m.

In this case, the wire pairs have stranded in the SZ

SZ stranded. Each five pairs are then converted into continuous stranding a bundle is made, its twisting

, ₍₎ dn = + 6 * 2 π / m

Several such bundles are then followed by the twist

dn = + 2 ■ 2 π / m

> continuously stranded to the soul.

The sum of the continuous twists is then

c / i4 = dn + d \ i = + 8-2 π / m.

The following pair of drillunjo then lie in the Xabel soul gen before:

c / i5 = d \ a + t / 14 = + 10 2 π / m
and

</ i6 = du + d \ 4 = + 6 2 π / m.

Since in this case the sum of the continuous twists is greater than the SZ twists is, the pairs in the finished cable core always have a constant twisting direction. From the Originally existing reversals of the twisting direction are more continuous due to the superposition Twistings become twist change points.

Similar results can also be achieved if, in the manufacture of the cable core, initially two successive SZ stranding processes are provided. For example, if you have couples in the im previous example are SZ-stranded, to the bundle again SZ-stranded, namely with the drills

and

du = + 3 2 π / m
dia 2-2 π / m

and the bundles produced in this way then continuously with the twist

Ci ₁₉ = + 6 * 2 π / m

stranded to form the core, the final pair twists in the cable core lie between

and

c? 2o = + 11-2 π / m
d ₂ \ = + 2 ■ 2 π / m.

In the examples given, it was assumed in each case that the SZ stranding leads to stranding units b ^r > or stranding groups in which the twist is constant in sections.

Claims (1)

Claim: Method for producing electrical cables or lines in a bundle structure by stranding, in which the cable core is formed in at least two successive stranding processes, of which at least the first is a stranding process, the stranding units with sections alternating twisting direction (SZ stranding process), and of which at least one further stranding process to form a stranding group with always constant twisting direction (continuous stranding processX thereby characterized that the largest resulting twist of the SZ stranding process or the largest resulting twist of all SZ stranding processes smaller than the smallest twist of the continuous stranding process or smaller than the smallest resulting twist of all continuous ones Stranding processes is. When producing electrical cables and wires in a '*' multi-stage stranding process, it is customary to increase the lay length s of the respective stranding process from stranding stage to stranding stage, i.e. a smaller twist d from stranding stage to stranding stage