JPH01117211A - Manufacture of self-supporting type cable - Google Patents

Abstract

PURPOSE:To manufacture a cable with no neck-bending phenomenon continuously by the automatic control, by suppressing the neck-bending phenomenon owing to the residual stress of a hanging wire by applying a twisting when the cable is supplied. CONSTITUTION:When the neck of a self-supporting type cable which is extruded by an extruding machine 13 and covered generates a neck bending, the rack 12b of a wire supply 12 is rotated around a rotary shaft 12c as the axis to give a twisting in the arrow direction 20 in the figure to a hanging wire 3. The twisting direction is selected to clockwise or counterclockwise depending on the neck bending direction. And the twisting amount, that is, the rotation numbers of the wire supply rack 12b around the rotary shaft 12c while the hanging wire 3 is fed at a specific length by the extruding machine 13, is selected responding to the neck bending amount of the neck of the self-supporting type cable 1.

Description

[Detailed description of the invention] (Technical field of invention) The present invention relates to an apparatus for manufacturing self-supporting cables.

(Technical background of the invention and its problems) Self-supporting cables are widely used as communication cables, power distribution cables, and the like. FIG. 3 shows a cross-sectional view of such a self-supporting cable.

This cable 1 has an insulated wire core 2 and a suspension wire 3, and has a structure in which the outer periphery of these wires is integrally covered with a common jacket 4. A neck portion 4c is formed to connect the cable main body portion 4a and the hanging wire portion 4b. Such a cable is manufactured by an extruder that feeds the insulated wire core 2 and the suspension wire 3 into a crosshead, and integrally extrudes and coats the outer periphery of these with a jacket.

By the way, when manufacturing such a cable, for example, as shown in FIG.
c is not in a straight line and the suspension line portion 4b is tilted to either the left or right,
So-called neck bending may occur. There are various possible causes for this phenomenon, and one of them is considered to be the rotational force of the suspension wire 3. This is because when a steel stranded wire is used as the suspension wire 3, due to residual stress during manufacture of the steel stranded wire, the steel stranded wire rotates as it is being pulled out toward the extruder during extrusion coating, causing the neck to bend. By letting it happen.

For example, in FIG. 4, when the suspension line 3 receives a force that causes it to rotate in the direction of the arrow 6, the suspension line portion 4
The center line of b is tilted to the left with respect to the neck portion 4c. Therefore, in order to suppress the neck bending phenomenon caused by such causes, it is sufficient to reduce the residual stress in the hanging wire 3 as much as possible. However, it is extremely difficult to completely eliminate residual stress.

Therefore, conventionally, as shown in FIG. 5, for example, a method has been adopted in which the cable 1 after extrusion coating is sandwiched between a pair of grooved rollers to forcibly correct the bending of the neck. However, even with such a method, it is difficult to completely prevent the occurrence of neck bending because residual stress exists in the hanging wire 3.

(Objective of the Invention) The present invention has been made with attention to the above points, and it effectively suppresses the neck bending phenomenon even if residual stress remains in the suspension wire.
It is an object of the present invention to provide a manufacturing device that can automatically manufacture a good self-supporting cable.

(Summary of the Invention) A self-supporting cable manufacturing apparatus of the present invention includes a cable supply supplying an insulated wire core, a wire supply supplying a suspension wire, the outer periphery of the insulated wire core, the outer periphery of the suspension wire, and a neck portion connecting these. and an extruder for coating the common jacket on the wire, and a neck bending detection section for inspecting the neck of the common jacket coated by the extruder and detecting the amount of bending of the neck, and the wire supply is configured to a twisting means for supplying a hanging wire so as to give a twist to the hanging wire; The feature is that the direction is selected.

(Embodiment of the Invention) FIG. 1 is a plan view showing an embodiment of the self-supporting cable manufacturing apparatus of the present invention.

In the figure, this device includes a cable supply 11 that supplies an insulated wire core 2 and a wire supply 1 that supplies a suspension wire 3.
2 are provided. Then, the insulated wire core 2 and the hanging wire 3
In the direction in which they are fed, an extruder 13 is provided which coats them with a common jacket. Further, behind the crosshead 13a of the extruder 13, there is an auxiliary water tank 15 for temporarily cooling the extruded common jacket, and for the self-supporting cable 1 after extrusion coating, the neck of the common jacket is inspected and the neck is bent. A neck bending detection unit 14 that detects the amount of bending and a cooling tank 16 that cools the common jacket to room temperature are provided.

Here, the wire supply 12 is a device for supplying the suspension wire 3 toward the extruder 13. This wire supply 12 is composed of a drum 12a around which the hanging wire 3 is wound, and a pedestal 12b that rotatably supports the drum 12a and has a rotation axis 12c orthogonal to the rotation axis of the drum 12a.

The device of the present invention rotates the mount 12b of the wire supply 12 about its rotation axis 12c when the neck of the self-supporting cable 1 extruded and coated by the extruder 13 has a neck bend, Arrow 20 in the diagram on suspension line 3
Try to give a twist in the direction. The twisting direction is selected as either clockwise or counterclockwise depending on the direction of neck bending. In addition, the amount of twisting, that is, the number of rotations of the wire supply 12b around the rotating shaft 12c while the suspension wire 3 is supplied to the extruder by a predetermined length, depends on the neck of the self-supporting cable 1. It is selected according to the amount of neck bending.

Note that, as shown in FIG. 4, for example, the neck bending detection unit 14 uses, for example, a pair of rods 21 circumscribing the self-supporting cable after it has been covered with the common jacket 4, and detects the angle between the two rods. The amount of neck bending is calculated by detecting α. The direction of neck bending can be detected by the relative angle between the crosshead and this rod 21.

Further, grooved rolls 7 as shown in Fig. 5 are provided, and when the cable l runs between them, the force that pushes the grooved rolls 7 apart is measured to detect the direction and amount of neck bending. You can. The direction and amount of neck bending can also be detected by using an optical or contact sensor, or by other various methods.

On the other hand, the wire supply 12 twists the hanging wire 3 so as to reduce such neck bending. The operation will be explained using FIG. 2.

First, it is assumed that the cable 1 has a bent neck as shown in FIG. 2(a). In this case, if the hanging wire 3 is pulled out from the wire supply and supplied as is in the conventional manner, it will rotate as shown by the arrow 6 and the neck will bend. In the device of the present invention, the neck bending detection section 14 (FIG. 1) detects the neck bending direction at this time,
The hanging wire 3 is twisted in the direction of arrow 20'. As a result, the direction in which the suspension wire 3 rotates to relieve stress and the direction in which the suspension wire 3 is twisted by the wire supply 12a (FIG. 1) cancel each other out, thereby preventing the neck bending phenomenon.

Further, as shown in FIG. 2(b), when the neck bending phenomenon occurs in the opposite direction to that shown in FIG. 2(a), the neck bending detection section 14 detects this and
a (FIG. 1) twists the hanging wire 3 in the direction of the arrow 20'. As a result, as explained in FIG. 2(a), the rotational force based on the residual stress of the suspension wire 3 is canceled out, and the neck bending phenomenon is prevented.

As described above, the neck bending detection unit 14 detects the extruder 13
The wire supply 12a applies a predetermined amount of twist to the suspension wire 3 in a predetermined direction each time while detecting the amount of neck bend of the self-supporting cable 1 which is extruded and coated at the crosshead 13a. This ensures that the self-supporting cable always has a minimum bend in its neck and is wound up with a common jacket.

(Effects of the Invention) According to the self-supporting cable manufacturing apparatus of the present invention described above, the neck bending phenomenon caused by the residual stress of the suspension wire 3 is suppressed by twisting the suspension wire 3 when it is supplied. Through so-called automatic control, it is possible to continuously manufacture self-supporting cables without neck bending phenomena.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a manufacturing device for a self-supporting cable showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation for reducing the amount of neck bending, and Fig. 3 is a plan view of a self-supporting cable manufacturing device showing an embodiment of the present invention. FIG. 4 is a cross-sectional view of a self-supporting cable in which a neck bending phenomenon has occurred, and FIG. 5 is a cross-sectional view of a case in which a grooved roller is used to correct the neck bending phenomenon. 1--11--Self-supporting cable, 2-1-
---------Insulated wire core, 3----1--Suspension wire, 4-----11--Common jacket, 4c-----M-Neck , 11--1--Cable supply, 12--
-7----Wire sublime, 13-1------
Extruder, 14-1--Neck bending detection section, 15--1-
--------Auxiliary water tank, 16----------Cooling water tank. 1----------m-Self-supporting cape) 2----
-1-----Rectangular brocade core 3--1--Suspension 4---1 Common outer covering 4c -1--------- Neck 11 −−1−−−−−−Keifun Renafari 12−
------1---- Wire supply ply 13 ----1---
--H1m 14 ------1--Kubiichikiri Darishiya Deai β15
-----------1 Hakusho 16--1-----Iriha Oqso Figure 1 Figure 2 (a) (b)

Claims (1)

[Claims] a cable supply for supplying an insulated wire core; a wire supply for supplying a suspension wire; an extruder for coating the outer periphery of the insulated wire core, the outer periphery of the suspension wire, and a neck portion connecting these with a common jacket; and a neck bending detection unit that inspects the neck of the common jacket and detects the amount of bending of the neck, and the wire supply has twisting means for supplying the hanging wire so as to give twist to the hanging wire. , this twisting means is
A manufacturing device for a self-supporting cable, characterized in that the twist amount and twist direction of the suspension wire are selected so as to reduce the neck bend amount detected by the neck bend detector.