JPH0440812B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides the following advantages when twisting insulator-coated wires:
The present invention relates to a method of manufacturing an inclusion-interposed stranded wire cable having an inclusion therebetween.

(Prior Art) Conventionally, as a part of the power cable, for example, the second
As shown in the cross-sectional view in the figure, there are multiple
Insulator-covered wires (hereinafter simply referred to as insulated wires) 3, each of which is made by covering the outer periphery of a wire 1 made of a plastic material or the like with an insulator 2, are twisted together, with an inclusion 4 interposed between the twists. An interposed twisted wire cable (hereinafter simply referred to as an interposed cable) is known, which is constructed by covering the above with a sheath 5.

However, the conventional manufacturing method for such interposed cables is to first manufacture continuous rod-shaped inclusions made of flexible plastic material with a circular or triangular cross section using an ordinary plastic extruder or the like, and then insert them into a winding drum. It is manufactured by winding it up, twisting it together with insulating wires 3 twisted using various twisting machines, and then covering it with a sheath 5 using a sheath extruder.

(Problems to be Solved by the Invention) However, in such conventional manufacturing methods, the manufacturing of inclusions and the manufacturing of insulated strands are performed in separate processes, making the manufacturing process complicated, increasing equipment costs, In addition to increasing power costs and other costs, it is extremely difficult to accurately position the inclusions in the gaps between the insulated wires and twist them together, resulting in misalignment of the inclusions, making it difficult to create a cable with a good cross-sectional shape. However, there are also disadvantages such as insufficient protection of the insulated wires, which reduces the commercial value of the cable.

The present invention has been made by focusing on the conventional drawbacks in manufacturing interposed cables, and it can be done in one step from insulated strands, and there is no displacement of the position of the interposed cable.
It is an object of the present invention to provide a manufacturing method capable of manufacturing an intervening cable with high commercial value at low cost using simple equipment.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a process of extruding an inclusion from each of a plurality of molding dies arranged in a circle around a central axis of a rotating body. and inserting a plurality of insulator-coated strands that rotate parallel to the axial direction of the rotary body and in synchronization with the rotary body into a hollow shaft formed in the rotary body, so that the wires rotate at approximately the same speed as the inclusion. and a step of twisting the inclusions and the insulator-coated strands together.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below along with its operation based on the accompanying drawings showing embodiments.

FIG. 1 shows a half sectional view of a rotary head A for extruding inclusions used in the present invention.

In the figure, reference numeral 6 denotes a rotary body constituting the rotary head A, and a hollow portion 7 having a relatively wide cross section in the direction of the central axis is provided through the rotary body. Further, an annular groove 8 is provided along the outer periphery of the rotating body 6, and a pocket 9 is provided inside the annular groove 8 in communication with the bottom of the groove. Further, on one end surface of the rotating body 6, a required number of forming dies 10 communicating with the pocket 9 are arranged in a circle around the central axis. The nozzle shape of this molding die 10 is formed in a shape corresponding to the cross-sectional shape of the inclusion 4 to be extruded.

Further, 11 is a housing, 12 is a fixed shoe member fitted into the annular groove 8, and a part thereof has a supply path (not shown) for the inclusion material communicating with the pocket 9. Further, 13 is a sprocket for rotationally driving the rotating body 6, and 14 is a bearing.

In order to manufacture an intervening cable using the rotating head A having such a configuration, the rotating body 6 is rotated at a predetermined rotational speed via the sprocket 13, and a plurality of cables to be twisted are placed in the hollow part 7 of the rotating body 6. The insulated wire 3 is fed out while being rotated parallel to the axial direction. Although any appropriate means can be used to feed out the insulated wire 3, it is extremely easy to deliver the insulated wire 3 in one step by using a method that coats the wire extruded by a rotary extrusion machine with an insulator in a rotating state. can be done. That is, FIG. 4 is a sectional view of a main part of a rotary extrusion molding machine, the details of which are shown in Japanese Patent Publication No. 59-36716. This extrusion molding machine is arranged to the left of the rotary head A for extruding inclusions shown in FIG. 1, and the rotating body 7 in FIG. 1 and the rotating body 15 in FIG. We are doing so.

That is, in FIGS. 4(a) and 4(b), 15 is a rotating body rotated by a drive mechanism (not shown). An annular groove 16 having a pocket 17 at the bottom of the groove is formed in the outer periphery of the rotating body 15, and an annular fixed shoe member 18 is engaged with the groove 16. The fixed shoe member 14 has a wire passage a for supplying material (rough drawing wire), and a guide roll 35 for feeding the rough drawing wire is provided at the entrance thereof. The amount of protrusion into the groove 16 gradually increases in the direction of rotation of the body 15 (in the direction of arrow symbol b),
The cross-sectional area of the pocket 17 formed by the groove 16, the groove bottom, and the inner circumferential wall of the fixed shoe gradually decreases. Further, a plurality of dice 20 are arranged in a circle on the rotating body 15 and are fitted into a die holder 19 facing the pocket 17.

In the apparatus constructed as described above, first, the rough wire as a material is supplied into the pocket 17 from the wire passage a of the fixed shoe member 18 along the guide roll 35. As the rotating body 15 rotates, the wire rod supplied into the pocket 17 advances to fill the interior of the pocket 17 due to its frictional force. Since the pocket 17 has a structure in which the cross-sectional area gradually decreases, the material progresses while being compressed, and when a predetermined compressive stress is reached,
The die 20 continuously extrudes the wire into a wire having a desired wire diameter. The strands extruded in this way are rotating together with the rotating body.

FIG. 5 shows an insulator coating device for coating the plurality of wires 1 thus extruded with an insulator while imparting rotation to them, and is shown in a half-sectional view. This insulator coating device is inserted between the extrusion molding machine shown in FIG. 4 and the rotary head for extruding inclusions shown in FIG. 1, and the rotating body 21 of the insulator coating device in FIG. , are arranged so that their central axes substantially coincide with the rotating bodies 7 and 15. In the figure, 21 is a rotating body that is rotated in synchronization with the rotating body 15 of the extrusion molding machine through a sprocket 22 attached to one end, 23 is an annular groove provided on the outer periphery of the rotating body 21, and 24 is an annular groove. A pocket 23 communicates with the groove bottom, 25 a fixed shoe member partially fitted into the annular groove 23, 26 a housing, and 27 a bearing. Further, 28 is an insulator coating means, which is composed of a metal core 29 and a base 31 connected to the metal core 29 via a slit 30. This insulator covering means 2
8 are provided in the same number and in the same phase corresponding to the dies 20 provided on the rotating body 15 of the extrusion molding machine.

The plurality of wires 1 sent out from the die 20 of the extrusion molding machine are each synchronously rotated with the core bar 2 of the insulator coating means 28 of the insulator coating device.
9 and is coated with an insulating material in a heated fluid state supplied via the pocket 24 and the slit 30 from a known plastic extruder, not shown, via a supply path, also not shown. The wire 3 coated with an insulator is passed from the base 31 to the rotating body 2.
It is extruded parallel to the axial direction of 1 and while being rotated. Next, the extruded plurality of insulating strands 3 are rotated and transferred through the rotary body hollow part 7 of the rotary head A for extruding inclusions without contacting the inner wall surface.

On the other hand, the rotary body 6 of the rotary head A is rotated via the sprocket 13 in synchronization with the rotary body 15 of the extrusion molding machine and the rotary body 21 of the insulation coating device, respectively, and is also rotated by an inclusion material extruder (not shown). The heated and fluidized inclusion material flows into the pocket 9 from a supply path (not shown) provided in a part of the fixed shoe member 12.

The inclusion material then passes from the pocket 9 to the branch channel 9.
a, and is sent to a plurality of forming dies, where it is extruded at the same speed as the insulating wire 3 as an inclusion 4 having a predetermined cross-sectional shape. The extruded inclusions 4 and the insulating wires 3 are rotated parallel to each other, and are cooled by passing through a cooling water tank (not shown) arranged in series with the rotating head A, and then passing through a cooling water tank (not shown) arranged in series with the rotating head A. The rotational force causes the fibers to be twisted together.

The insulated wires 3 twisted together with the inclusions 4 are
The sheath 5 is then coated using a known sheath extruder to produce an interposed cable as shown in FIG.

In the above manufacturing process, it is desirable that the cross-sectional shape of the inclusion 4 extruded from the rotary head A is formed so as to be correctly aligned with the gap formed by the insulating wire 3 and the sheath 5. When formed by twisting three insulating wires as shown in the figure, the cross-sectional shape of the inclusion 4 is as shown in Figure 3.
As shown in (a), it is approximately fan-shaped. but,
In order to more completely match the curvature of the outer peripheral surface of the inclusion 4 with the curvature of the inner surface of the sheath 5 and the outer surface of the insulated wire 3, a slit is formed on the outer peripheral surface of the inclusion 4 as shown in FIG. 3(b). By forming 4a in the longitudinal direction, the inclusion itself becomes a structurally elastic body and can flexibly respond to slight changes in curvature. Furthermore, if foamable plastic or the like is used as the inclusion material, not only can the above-mentioned consistency be further improved, but also the weight of the cable can be reduced.

(Effects of the Invention) The method for manufacturing an interposed cable according to the present invention is as described above in detail, and the inclusion includes a plurality of insulated wires that are fed out from within the hollow shaft of the rotating body while rotating in parallel with the axial direction. Since the insulated wires are twisted together in synchronization with the rotation of the insulated wires and always maintain a constant positional relationship with each other, they are aligned correctly in the gap formed by the insulated wires and the sheath, and the wire diameters of the multiple insulated wires are twisted. Even if there is some variation, a cable with a uniform cross section and high commercial value can be obtained. In addition, since the formation of the insulated strand and the inclusion of inclusions can be performed in one step, the manufacturing process is extremely simplified, and the strand formation using an extrusion molding machine and the insulating strand formation using an insulator coating device can be used in combination. This has the remarkable advantage that an unlimited number of intervening cables can be manufactured continuously in one step from a rough drawn wire.

[Brief explanation of drawings]

Fig. 1 is a half-sectional view of a rotary head for extruding inclusions used in the present invention, Fig. 2 is a sectional view of a stranded cable with inclusions, and Fig. 3 shows a and b used in the present invention. FIG. 4 is a diagram showing details of the extrusion molding machine, where (a) is a partially broken side view, b is a cross-sectional view taken along line aC-C, and FIG. ,
FIG. 3 is a half-sectional view of the insulator coating device.

Claims (1)

[Scope of Claims] 1. A step of extruding an inclusion from each of a plurality of molding dies arranged in a circle around a central axis of a rotating body; A step of inserting a plurality of synchronously rotating insulator-coated strands into a hollow shaft formed in a rotating body and passing them at substantially the same speed as the inclusion, and the inclusion and the insulator-covered strand. A method for producing a stranded cable with inclusions, the method comprising the steps of: