DE2308545C3 - 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 unit made up of the stranding elements SZ, connected 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 carried out by means of an SZ stranding process, it comes 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 a main bundle and possibly 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-Verscilververfahren with different twisting in sections is for example in DE-AS 16 65 831 described, while an SZ stranding process 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 - 2 π / m,

d. H. Lay lengths of 5-15 cm; for stranding 2 »Pairs or star fours in a basic bundle Drilling from

d = 2 2 π / m,

for stranding basic bundles to form main bundle 2 "> a twist of

rf = 1 - 1.5 ■ 2 π / τη

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

^! " d = 0.6 ■ 2 π / m.

When manufacturing electrical cables and wires in bundles through a multi-stage stranding process, the first stranding stage of which is characterized by an SZ stranding is indicated by the SZ-stranded stranding units for themselves and also in the manufacture cable core reversals in the direction of twist on. In the area of these reversal points, the stranding elements are only inadequately stranded or not stranded at all.

4 (i At these points the respective stranding element or the respective stranding unit therefore has unfavorable bending properties, as a result of which cables are frequently moved or cables can break early. It is also possible that wire pairs are connected to these

• Γ) untwisted or insufficiently stranded places at Bending of the cable or line are basketed and that thereby the electrical symmetry of the Wire pair is deteriorated.

The invention is therefore based on the object

■ vi through a further development of the aforementioned Method with such electrical cables and plumbing the flexibility in the area of the SZ stranding resulting in reversals of the twisting direction.

3 ") This task is then solved by a process as it is described in detail in the characterizing part of the claim.

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

Wi stranding processes ensure that by overlaying the twisting of the SZ-Verseilvorgangsc with the twisting or twisting of the continuous In the stranding process in the finished cable core, reversals of the twisting direction no longer occur.

h, by superimposing the SZ drills and the continuous twists such a shift in level of the still existing ones SZ twist instead of the fact that the reversal points of the twisting

lungsrichiung in change points of the twist constant twist direction. For example, in the case of a communication cable made up of basic bundles, 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 twists. 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 Sum of the subsequent continuous twists to be selected. 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 in parallel working stages in pairs SZ-stranded and the pairs produced in this way immediately afterwards in the same operation continuously are stranded in a bundle, the following conditions exist, for example:

The twist of the SZ stranded pairs is

d = ± 5-2 .T / m.

The continuous twisting when stranding the \ of the pairs to the bundle

d ₂ = + 2 * 2 π / m.

After going through this two-stage versing process the pairs of wires show the following by superimposing the twists obtained in the two twisting stages final twists on:

c / i '= + 7 ■ 2 π / m, b \ "= - 3 · 2 π / m.

So in the finished basic bundle there are Uiukehrslellen 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 in the second stranding stage Application comes. For example, there are five wire pairs with the SZ twists

Bundle of twists made by

d _t = d \ + d _b =

■ 2 π / m

d, = + 5-2 .τ / m

up to

di = -5-2 π / m
SZ-stranded with the following twists to form a bundle:

d _h = + J ■ 2 .τ / m
and

d ₇ = - 3 ■ 2 π / m.

In this case, Hie Ademaare in SZ-stranded <h = d ₂ +

-8-2 π / m

rich, d. i.e., in this case, too, occur at intervals again reverse parts of the twisting direction and thus insufficient or not sunk 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

c / iob or c / n = ± 2 · 2; r / m

SZ stranded. A bundle is then made from five pairs in continuous stranding. its twisting

du = ■ + 6 · 2 π / m

amounts to. Several such bundles are then used with the twist

du = + 2-2 π / m

continuously stranded to the soul.

The sum of the continuous twists is then

c / i4 = d \ 2 + du = + 8-2 π / m.

The following twisted pairs are then located in the cable core before:

J ₁₅ = d \ a + du = + 10 2 π / m
and

dib = dw + du = + 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 twist direction have become twist change points through the superposition of continuous twists.

Similar results can also be achieved if, in the manufacture of the cable core, initially two successive SZ-Verseilvorgangsc 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

+ 3 x 2 π / m

d \ H = - 2 · 2 π / m

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

d \ s, - + 6 ■ 2 π / m

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

c / ₂₀ = +11 -2 π / m d ₂ \ = + 2 · 2 π / m.

In the examples given, it was assumed in each case that the SZ stranding results in rope units 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 process), 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. In the manufacture of electrical cables and wires in a multi-stage stranding process, it is common to let the lay length s of the respective stranding process increase from stranding stage to stranding stage, i.e. a smaller twist d from stranding stage to stranding stage