JPH06349361A - Manufacture of cv cable - Google Patents

Abstract

PURPOSE:To provide a manufacturing method of a CV cable, capable of increasing production efficiency and decreasing facility cost by shortening the length of the production line of the CV cable. CONSTITUTION:A silane crosslinked insulating layer 7a and a polyvinyl chloride layer 8a are formed on a cable conductor 1 by using an extrusion head in which a condcutor passing through hole 2a for passing a cable conductor 1, a resin flow path 2b for passing a silane crosslinked insulating resin 7 extruded from an extruder 5, and a resin flow path 2c for passing polyvinyl chloride extruded from an extruder 6 are coaxially arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a CV cable suitable for manufacturing a low voltage CV cable such as a single-core type CV cable or a triplex type CV cable.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing a single-core CV cable. This single-core CV cable has a cable conductor 11
Cross-linked polyethylene (XLPE: cross-linked p
An insulator layer 12 made of olyethylene) and a sheath 13 made of polyvinyl chloride (PVC) are coaxially arranged.

FIG. 4 is a sectional view showing a triplex type CV cable. The triplex type CV cable has an insulating layer 22 made of cross-linked polyethylene and a sheath 23 made of polyvinyl chloride around a cable conductor 21.
Is formed by twisting and integrating three cables that are coaxially arranged.

For example, in a low voltage CV cable of the 660V class, as shown in FIGS. 3 and 4, it is not necessary to provide a metal shielding layer between the insulating layers 12 and 22 and the sheaths 13 and 23. The step of winding the conductive tape and the semi-conductive tape on the tape is not required. Also, the insulator layer 1
If 2, 22 are formed by a silane cross-linking method (a method of cross-linking silane-grafted polyethylene with a water catalyst), a heat source for DCP (dicumyl peroxide) chemical cross-linking, which is necessary in the vapor cross-linking method and the gas cross-linking method, and Since the pressurization for preventing foaming is unnecessary, the manufacturing process can be simplified. As a method of manufacturing a CV cable in which the manufacturing process is simplified in this way, there is a method of manufacturing a tandem CV cable in which extrusion of a silane crosslinked insulator resin and extrusion of polyvinyl chloride are continuously performed.

FIG. 5 is a schematic view showing a method of manufacturing a CV cable by the tandem system. The cable conductor 31 delivered from the delivery device 36 has a silane crosslinked insulator layer formed around it by the silane crosslinked insulator resin extruded from the crosshead of the extruder 32 when passing through the extruder 32. This silane cross-linked insulator layer is cooled in a cooling water tank 33 arranged at the subsequent stage of the extruder 32. Thereafter, the cable in which the insulating layer is formed around the cable conductor 31 is polychlorinated around the insulating layer by polyvinyl chloride extruded from the crosshead of the extruder 34 when passing through the extruder 34. A vinyl layer (sheath) is formed to form a CV cable. The CV cable is cooled in the subsequent cooling water tank 35 and then wound up by the winder 37.
In this way, the CV cable is completed.

In order to coaxially form the insulating layer and the sheath around the cable conductor with one extrusion head, a plurality of resin flow paths are coaxially arranged around the conductor passage hole through which the cable conductor passes. In addition, an extrusion head has been proposed in which a release agent extrusion passage and a porous metal member are provided in the core nipple between the resin flow paths (Japanese Patent Publication No. 62-37489). According to this extrusion head, the release agent oozes out from the metal member between the resin to be the insulating layer and the resin to be the sheath, and the multilayer extrusion coating is performed while avoiding fusion between the insulating layer and the sheath. An electric wire having the same can be manufactured.

[0007]

However, in the above-mentioned tandem CV cable manufacturing method,
Since the two processes (that is, the insulating layer forming step and the sheath forming step) are connected in series, there is a drawback that the line length of the manufacturing line becomes long and a large space is required. In addition, it is necessary to dispose two sets of cooling water tanks and two crossheads, which has a drawback of high equipment cost. Further, since the line length is long, the workability is poor, and it is difficult to start the operation of two extruders at the same time, and the movement of the operator for the quality check is complicated. There is also the difficulty that the original purpose of line conversion, namely labor saving, cannot be achieved.

On the other hand, in the extrusion head disclosed in Japanese Patent Publication No. 62-37489, it is necessary to provide a release agent extruding passage in the core nipple and to dispose a porous metal member at the tip of the core nipple. Therefore, the structure of the head is complicated and the manufacturing cost of the head is high.

The present invention has been made in view of the above problems, and it is possible to shorten the line length of a CV cable manufacturing line, reduce the equipment cost, and save labor. It is intended to provide a manufacturing method.

[0010]

A method for manufacturing a CV cable according to the present invention is directed to a conductor passage hole through which a cable conductor passes and a plurality of resin streams coaxially arranged in the conductor passage hole and separated from each other by a partition wall. A silane cross-linked insulator resin and polyvinyl chloride are concentrically extruded around the cable conductor by an extrusion head provided with a path, and an insulator layer made of the silane cross-linked insulator resin around the cable conductor and the It is characterized in that a sheath made of polyvinyl chloride is formed coaxially.

[0011]

According to the present invention, there is provided an extrusion head (common head) having a conductor passage hole through which a cable conductor passes and a plurality of resin passages coaxially arranged in the conductor passage hole and separated from each other by partition walls. Using this extrusion head, a silane crosslinked insulating resin and polyvinyl chloride are extruded concentrically around the cable conductor by the extrusion head, and an insulating layer made of the silane crosslinked insulating resin and the polyvinyl chloride around the cable conductor. To form a sheath. In this case,
Since the crosslinking of the silane crosslinked insulator resin absorbs water and gradually progresses, the silane crosslinked insulator resin extruded from the extrusion head is in a state where the crosslinking is not completed. In the present invention, the cross-linking of the silane cross-linked insulator resin is not completed, the vinyl chloride resin has a low fusion property with respect to the silane cross-linked insulator resin, and partition walls are provided between the resin flow paths. Combined with this, it is possible to reliably avoid fusion of the silane crosslinked insulating resin and polyvinyl chloride extruded from the extrusion head. That is, according to the method of the present invention, one set of the extrusion head and the cooling water tank is sufficient, and the production line length can be halved as compared with the conventional tandem CV cable production method, and the equipment cost can be reduced. It is possible to obtain the effect that the workability can be improved while the workability can be reduced. Further, since it is not necessary to supply a release agent between the insulating layer and the sheath, there is an advantage that the structure of the extrusion head is relatively simple and the manufacturing cost of the extrusion head is low.

Conventionally, CCV (Catenary Continuou)
s Vulcanizer: Catenary type continuous crosslinking machine) and VCV
(Vertical Continuous Vulcanizer)
In some cases, a co-extrusion method in which a plurality of resins are simultaneously extruded by using an extrusion head having a plurality of resin flow paths is applied. However, these continuous cross-linking machines are for extruding an insulating layer and a semiconductive layer while adhering them to each other, and the extrusion molding temperature of the molten resin for forming the insulating layer and the semiconductive layer is It is almost the same. On the other hand, the present invention forms the insulator layer and the sheath of the CV cable, and it is necessary not to fuse the both. Therefore, in the present invention, the materials of the insulating layer and the sheath are limited to the silane cross-linked insulating resin and polyvinyl chloride, respectively. For example, the extrusion temperature of the silane cross-linked insulator resin is 160
If the extruding temperature of polyvinyl chloride is set lower than this (for example, 150 to 170 ° C.) to form the insulator layer and the sheath, fusion of both can be avoided. In addition, for example, a space may be provided in the partition wall, the space may be maintained in a negative pressure state, and heat conduction by the partition wall may be suppressed, so that the temperature difference at the time of extruding each resin is not reduced.

[0013]

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a schematic view showing a method of manufacturing a CV cable according to an embodiment of the present invention. The cable conductor 1 sent from the sending machine 4 passes through the inside of the extrusion head 2 and then through the cooling water tank 3 and is wound up by a winding machine (not shown). In the extrusion head 2, the silane cross-linked insulator extruder 5 and the PVC extruder 6 extrude the silane cross-linked insulator resin and polyvinyl chloride concentrically around the cable conductor 1, respectively.

FIG. 2 is a schematic sectional view showing the extrusion head 2. The extrusion head 2 has an inner resin flow path 2b through which the silane cross-linked insulating resin 7 that is an insulating layer material passes and a polyvinyl chloride 8 that is a sheath material that passes through the conductor passage hole 2a through which the cable conductor 1 passes. The outer resin flow passage 2c is provided coaxially, and the conductor passage hole 2a and the inner resin flow passage 2 are provided.
Partitions 9a and 9b separate the inner resin flow passage 2b and the outer resin flow passage 2c from each other. Also,
The inner resin flow channel 2b communicates with the silane crosslinked insulator extruder 5, and the outer resin flow channel 2c communicates with the PVC extruder 6.

Using the extrusion head configured as described above, the silane cross-linked insulating resin 7 is fed from the extruder 5 while passing the cable conductor 1 through the conductor passage hole 2a, for example, 160 to 2
Extruded at a temperature of 50 ° C., and extruded from the extruder 6 to polyvinyl chloride 8
Is extruded at a temperature of 150 to 170 ° C., for example. The silane cross-linked insulator resin 7 and the polyvinyl chloride 8 pass through the inner resin flow passage 2b and the outer resin flow passage 2c, respectively, and the cable conductor 1
A silane cross-linking insulation layer 7a and a polyvinyl chloride layer 8a are coaxially formed around the cable conductor 1 by being concentrically attached to the peripheral surface of the. The cable 10 in which the silane bridge insulation layer 7 a and the polyvinyl chloride layer 8 a are coaxially arranged around the cable conductor 1 then enters the cooling water tank 3. In this cooling water tank 3, the cable 10 is cooled and the silane cross-linked insulator resin is cross-linked. As a result, the CV cable in which the insulating layer and the sheath are coaxially arranged around the cable conductor 1 is completed.

In the extrusion head 2, the resin flow path 2b,
Since 2c is separated from each other by the partition wall 9b, fusion between the silane crosslinked insulator layer and the polyvinyl chloride layer can be reliably avoided.

In this embodiment, the extrusion head and the cooling water tank may each be one set, and the conventional tandem type CV is used.
Compared to the cable manufacturing method, the line length is about half,
The equipment cost can be reduced. In addition, the workability is good because the movement distance of the operator when starting the operation of the device and when performing quality check, etc.
Labor saving can be achieved.

Next, the CV is actually performed by the above-described embodiment method.
The result of manufacturing the cable and examining the presence / absence of fusion between the insulating layer and the sheath will be described.

Using an extrusion head of the construction shown in FIG.
600V single-core CV cable (cross-sectional area: 100mm
² ) manufactured. The temperature during extrusion of polyvinyl chloride was set to 150 to 170 ° C, and the temperature during extrusion of the silane crosslinked insulator resin was set to 160 to 250 ° C. The terminal lead-out performance of the electric wire of the CV cable manufactured in this manner was examined. As a result, C produced by the method of this example
The terminal output performance of the V cable was the same as that of the CV cable manufactured by the conventional tandem method and the method of separately forming the insulating layer and the sheath.

The silane cross-linking insulator extruder is classified into a one-shot type (press-in type of a silane liquid as a cross-linking agent) and a two-shot type (silane graftmer type), but the present invention can be applied to both. . When a separator is required between the insulating layer and the sheath, a common head having two resin flow paths and one separator guide is used, and a silane crosslinked insulating resin, a separator and polyvinyl chloride are used from this common head. May be extruded to coaxially form the insulator layer, the separator and the sheath.

[0022]

As described above, according to the present invention, the conductor passage hole through which the cable conductor passes and the plurality of resin passages coaxially arranged in the conductor passage hole and separated from each other by the partition wall are provided. Using an extrusion head, the extrusion head concentrically extrudes a silane bridge insulation resin and polyvinyl chloride around the cable conductor, and an insulation layer made of the silane bridge insulation resin around the cable conductor and Since the sheath made of polyvinyl chloride is formed, CV
The line length of the cable manufacturing line can be shortened, workability is significantly improved, and the facility cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a method for manufacturing a CV cable according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing an extrusion head used in an example method of the present invention.

FIG. 3 is a cross-sectional view showing a single-core CV cable.

FIG. 4 is a cross-sectional view showing a triplex CV cable.

FIG. 5 is a schematic view showing a method for manufacturing a CV cable by a conventional tandem system.

[Explanation of symbols]

 1, 11, 12, 31; cable conductor 2; extrusion head 2a; conductor passage holes 2b, 2c; resin flow paths 3, 33, 35; cooling water tanks 5, 6, 32, 34; extruder 7; silane bridge insulator Resin 8; Polyvinyl chloride 9a, 9b; Partition wall 12, 22; Insulator layer 13, 23; Sheath

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuhiro Uchiyama 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Ltd. (72) Inventor Toru Okawara 1-1-5, Kiba, Koto-ku, Tokyo Shares Company Fujikura (72) Inventor Nobutaka Sekine 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Stock Company (72) Inventor Koji Hosoya 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Stock Company (72) Inventor Takeshi Maeda 1-5-1, Kiba, Koto-ku, Tokyo, Fujikura Ltd. (72) Inventor Masahiro Ikegami 1-1-5, Kiba, Koto-ku, Tokyo, Fujikura Ltd.

Claims (1)

[Claims] 1. An extrusion head provided with a conductor passage hole through which a cable conductor passes and a plurality of resin flow passages coaxially arranged in the conductor passage hole and separated from each other by a partition wall, thereby providing a periphery of the cable conductor. A silane cross-linked insulator resin and polyvinyl chloride are extruded concentrically to form an insulating layer made of the silane cross-linked insulator resin and a sheath made of the polyvinyl chloride coaxially around the cable conductor. And a method of manufacturing a CV cable.