JPS5926087B2 - Communication cable manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a communication cable, and more specifically, to manufacturing a SZ stranded wire such as a cut stranded wire or a twisted pair wire by SZ twisting the bare wires of a communication cable by a rotation change method. , these SZ twisted wires are combined into S by the accumulation inversion method.
The present invention relates to a method for manufacturing communication cables by Z-combined twisting.

Conventionally, when manufacturing communication cables, four (or two) bare wires of the communication cable are VSZ-twisted using the accumulation inversion method to produce cut stranded wires (or twisted pair wires), and these twisted wires are A widely used method is to twist a plurality of wires (usually five wires in the case of cut twisted wires) in a VSZ manner using the accumulation and inversion method. As is well known, in the storage inversion method, a plurality of wires gathered together using a twisting die are guided into a storage cradle that can rotate around the direction in which the wires travel as an axis, and the wires are placed immediately downstream of the storage cradle. This is a twisting technique in which SZ strands are produced by pulling out the wire through a twisting fixing point and reversing the storage cradle in the forward and reverse directions at intervals of the time that the wire passes through its storage length. When using this accumulation reversal method, a boundary between S twist and Z twist will appear in the SZ twisted wire of the product for each accumulation length of the accumulation cradle, but in the case of collective twist, the twist pitch is generally long.
In other words, since the rotational speed of the storage cradle is low, the loss of energy due to the reversal of the storage cradle and the existence of a parallel part with no twist at the boundary between the s-twist and the z-twist D are hardly a problem. When used to manufacture SZ stranded wires such as twisted wires, the twisting pitch is generally short, that is, the rotation speed of the storage cradle is high, so the loss of energy due to the reversal of the storage cradle is large, and The untwisted parallel portion that appears at the boundary between the Z and Z twists is also a problemD, and if the storage length of the storage cradle is increased in order to reduce such twist reversals, its mass will also increase. As a result, the rotational moment also increases, resulting in the disadvantage that the reversal of the storage cradle becomes even more unfavorable from the viewpoint of mechanical motion, including the loss of energy. The present invention has been made to eliminate such conventional drawbacks, and it solves the problem of SZ twisting of cut stranded wires or twisted wire pairs by the rotational change method, which was problematic in the prior art due to the accumulation and reversal method. The present invention provides a method for manufacturing a new communication cable characterized by the following features. First, the rotation variation method used in the method of this invention will be explained with reference to FIGS. 1 to 3.

In Figure 1, the filament ω to be twisted is at a constant linear velocity V. , a first fixed point F1, a first rotation point R1 located a short distance 11 downstream from this, and a second rotation point R2 located downstream by a distance l from the first rotation point R1, a short distance 12 from this. This diagram schematically depicts the state in which the vehicle passes through the second point F2, which is located downstream by a distance. Here, the fixed point is a part that allows the filament w to run freely but prevents rotation of the central axis 9, such as the part where one wrap around the pulley is wrapped. Similarly, is a part that engages with the striatum so as to allow the striatum w to run but prevent rotation of its central axis; By being rotationally driven, the filament is twisted. The process of the rotation variation method is to rotate the first rotation point R1 and the second rotation point R2 simultaneously and in the same direction in FIG.
, n2 with a constant period T.

The values are alternately changed. When the focused part of the striatum w passes through the first fixed point F1, this part of the striatum w passes through the upstream twisting section between the first fixed point F1 and the first rotation point R1. The degree of twist received (number of pitches per unit time and unit length), T1 is the first rotation point R1
If the rotation of is n(t) (a function of t), this same part of the striatum w travels a distance of 11+l and reaches the second rotation point R2.
The degree of twisting T2 that the part receives when it passes through is VO if the time in equation (1) is shifted by l + 21 and the direction of twisting is opposite, so from the superimposition of the twist, It can be seen that the degree of twist that this striatal portion ultimately acquires is represented by T1+T2.

Let's try implementing the above addition using a graph to make it easier to understand.

FIG. 2 shows this, and in the figure, the function n(t) has a period T. n1=1.5n0) and N2(
= 0.5n0), and it is assumed to be VO-1.
The above T1 is represented by a dashed line in the graph, T2 is also represented by a broken line, and their sum function T1+T2 is represented by a thick solid line. As we will see, the striatum w undergoes SZ twisting where the degree of twist 9 is equal to n1-N2,
As is clear from the graph, a parallel portion with zero twist occurs as indicated by P at the boundary between S twist and Z twist 9. -L for 11+l to eliminate this zero twist part
-1T.

In other words, the time required for the filament body 70w to travel from the first fixed point F1 to the second rotation point R2 is the rotation point Rl.
, R2 is required, and the graph in this case is shown by the thick solid line in FIG.

As can be seen from the above, the rotation change method does not reverse the rotation point, but only increases or decelerates it, so there is less energy loss during conversion, and therefore a relatively high rotation is required to drive the rotation point. numbers can be used.

Next, cut twist V (or pair twist 9) using the rotation change method described above.
The method of the present invention used for this purpose will be explained with reference to FIG.

FIG. 4 schematically shows the apparatus used to carry out the method of this invention. In the figure, w denotes a wire of a communication cable, and 1 denotes a twisting die, which corresponds to the first fixing point indicated by F1 in Figure 1. 2 is a first rotation point formed by a combination of rollers, 3 is a similar second rotation point provided downstream of the first rotation point 2, and 4 is a second fixed point similarly formed by a combination of rollers. The portion may also serve as the direction changing roller portion. The elements up to this point are used in the rotation variation method, and up to this point, an SZ twist cut or an SZ pair twisted wire is formed. It has already been described how SZ strands are formed by the rotation variation method. Therefore, a plurality of these SZ stranded wires, usually five in the case of cutting, are gathered together by the collection cap 5. 6 is a tape winding device, 7 is an introduction guide roller to the storage cradle 8, and 9 is a lead-out guide roller, where the twisting of the communication cable C made up of multiple SZ stranded wires is prevented and the storage cradle is connected to the storage cradle. The forward and reverse rotation of 8 gives the communication cable C an S twist or a Z twist.

This is the so-called accumulation reversal method for SZ twist9, and as is well known, the process is to reverse the rotation direction of the storage cradle for each accumulation length L of the accumulation cradle. Since it is well known to those skilled in the art whether this can be achieved, no explanation will be given here. The storage cradle has a large number of sieve groups, and the length of the striatum, which is passed back and forth over the sieves many times, and the length of the sieve storage are extremely long.

Therefore, since the mass of the storage cradle is large and its rotational efficiency is also large, the energy required to reverse its direction of rotation is quite large. However, in this invention, the SZ twist by reversing the storage cradle is used for the set twist 9, and since the pitch of this set twist is generally extremely long compared to that of the cut twist 9, etc., the rotational speed of the storage cradle is considerably higher than the linear speed. This means that the above-mentioned energy loss and wear in the rotational support portion do not pose any problems. According to this invention, (1
) Since the rotation change method is used for cutting and twisting (or twisting pairs 9) of communication cable bare wires, relatively high-speed twist v rotation can be used.

(Ii) The parallel part of the conversion boundary between S twist and z twist v does not appear until passing the second rotation point on the downstream side (R2 in Fig. 1), and after that, each SZ twist line of each cut etc. Since the twisting of the SZ strands itself is prevented, there is no need for an adhesive to prevent twisting. It is suitable for long pitches, and has the advantage of almost eliminating problems associated with reversing the storage cradle.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram for explaining the rotation variation method, Fig. 2 is a graph for explaining twist addition, Fig. 3 is a graph showing SZ twist obtained by the rotation variation method, Figure 4 is a schematic diagram of the apparatus used in the method of this invention. F1
...First fixed point, F2... Second fixed point, R1...
First rotation point, R2... Second rotation point, 5... Collection cap, 8... Accumulation cradle, 9... Twisting prevention fixing point.

Claims (1)

[Claims] 1 (a) A first fixed point F_1 that collects multiple communication cables and allows them to pass through but prevents them from twisting;
A similar first rotation point R located downstream and adjacent to this
_1, a similar second rotation point R_2 located downstream of this, and a similar second fixed point F_2 located downstream and adjacent to this
(b) driving the first fixed point R_1 and the second fixed point R_2 at two different rotational speeds n_1 and n_2 in the same direction at the same time and in the same direction; A step of rotating the wires alternately at intervals determined by the distance from the rotation point R_2 and the running speed of the strands, and (c) a plurality of SZ stranded wires formed by steps A and B above. (d) rotating the storage cradle in forward and reverse directions with a reversal period determined by its storage length; A method for manufacturing a communication cable, comprising the step of twisting the plurality of SZ twisted wires in SZ clusters.