JP2653211B2 - Apparatus and method for manufacturing self-supporting communication cable - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for manufacturing a self-supporting communication cable and a manufacturing method using the same, and more particularly, to a steel wire having a metal plating layer such as galvanized as a support wire. The present invention relates to a novel manufacturing apparatus and a new manufacturing method capable of always performing stable and stable extrusion coating of a common sheath.

[Prior Art] A self-supporting communication cable 10 is shown in FIG.
Because the cross-sectional shape resembles gourd,
Utan Type cable ( Is also a registered trademark of the applicant)
Specifically, the sectional view of FIG.
As shown in FIG.
A and the support wire 12 are integrally covered with the common sheath 13.
Then, the cable core 11 side and the support wire 12 side are
Are integrally connected.

By being integrated with the common sheath 13 in this way, the support wire 12 and the cable core 11 can be laid at the same time, so that the construction cost can be greatly reduced and the support wire is exposed. It also has the advantage of being less susceptible to corrosion.

In order to lay the self-supporting communication cable having the above configuration on a utility pole or the like, a wire is drawn while the sheath surface of the support wire is gripped by a gripper, and tension is applied.

At this time, if the support wire and the sheath are not evenly adhered in the longitudinal direction, the support wire and the sheath may be rubbed, the sheath may be damaged at the grip portion, and the internal support wire may be exposed. It is easy to occur. For this reason, it is required that the support wire and the sheath be in close contact with each other appropriately. Conventionally, a support wire that has no lubricating oil or the like adhered to the surface during wire drawing has been used. .

[Problems to be Solved by the Invention] As the support wire 12, a metal-plated steel wire such as a galvanized steel wire is generally used.

When manufacturing a self-supporting communication cable, an apparatus as shown in FIG. 1 is used, for example, the galvanized steel wire is used as a support wire 12, supplied to a crosshead together with a cable core 11, and the coating material is extrusion-coated. .

That is, the mandrel 1 and the base 4 are provided on the crosshead of the extruder.
The tip of the mandrel 1 provided inside the base 4 is branched into a mandrel 2 for the cable core and a mandrel 3 for the supporting wire (however, the conventional device does not support the mandrel). The wire mandrel 3 does not have the through hole 5). As shown in the figure, the cable core 11 and the support wire 12 are guided and positioned, respectively, and sent out to the forming die 4a of the base 4, and are shown in the forming die 4a. The coating material 13A melt-pressed by a screw is extrusion-coated to form the common sheath 13 by extrusion.

In this case, since the lubricant does not adhere to the galvanized steel wire serving as the support wire 12 as described above, a part of the plating film is peeled off every time the surface contacts the inner wall of the support wire core 3. However, this gradually accumulates and goes to cause clogging, and eventually, the support wire cannot be pulled out, and there has been a problem that extrusion coating becomes impossible.

An object of the present invention is to solve the above-mentioned problems of the prior art, and there is a possibility that clogging may occur in a support wire mandrel even when extrusion coated with a metal-plated steel wire having no lubricant as a support wire. In addition, it is an object of the present invention to provide a new device capable of always producing a self-supporting communication cable smoothly and stably, and a new production method using the same.

Means for Solving the Problems In the present invention, first, in a device for simultaneously extruding and coating a common sheath on a support wire and a cable core, a part of the coating material is supported before the distal end opening of the support wire mandrel. A plurality of through-holes that can flow into the wire are formed in a staggered arrangement. Second, a device having a support wire mandrel of such a configuration is used, and the support wire has a tip of the support wire mandrel. Before reaching the opening, a part of the coating material flows into the outer periphery of the support wire from the plurality of through holes formed in a staggered arrangement on the support wire mandrel, and the coating of the inflow material is applied to the surface of the support wire. Let it form
In this state, the core is passed through the inside of the mandrel to extrude the original coating layer.

[Operation] If the coating material is configured to be able to flow onto the support wire in the support wire mandrel, and a coating of the coating material is formed on the surface of the support wire in the mandrel with a part of the melt-pressed coating material. The coating acts as a kind of lubricant, and there is no possibility that the metal plating layer of the support wire is peeled off by the inner wall of the mandrel,
The conventional clogging is completely eliminated. In addition, since the coating acting as a lubricant is made of the same material as the coating material forming the coating layer, the adhesion between the support wire and the coating layer is sufficiently maintained as in the past, and trouble occurs during installation. There is no risk of cause.

[Example] Hereinafter, the present invention will be described with reference to examples.

FIG. 2 is an explanatory sketch showing an embodiment of the support wire mandrel 3 attached to the manufacturing apparatus according to the present invention.

The support wire mandrel 3 according to the present invention is formed with a plurality of through holes 5, 5 penetrating to the inside where the support wire runs, on the outer periphery at a position in front of the distal end opening 3a as shown in the figure.

FIG. 1 is a cross-sectional view showing a state in which a self-supporting communication cable 10 is manufactured by the method according to the present invention using the manufacturing apparatus according to the present invention equipped with the support wire core 3 according to the present invention. It is.

As explained earlier, the crosshead of the extruder
A base 4 and a mandrel 1 are provided on the inside thereof, and the distal end side of the mandrel 1 is branched into a mandrel 2 for a cable core and a mandrel 3 for a support wire, and a cable core 11 and a support wire 12 are respectively guided and positioned. Is done.

As the support wire 12, a metal-plated steel wire obtained by twisting seven metal-plated steel wires plated with zinc plating, aluminum plating or zinc-aluminum alloy plating is usually used. Generally, a wire in which a plurality of insulated core wires are twisted, and an outer periphery thereof is provided with a pressing tape is generally used.

In the device according to the present invention, through holes 5 are provided on the outer periphery of the support wire mandrel 3. Specifically, for example, the mandrel 3
Four through-holes 5, 5 each having a diameter of 4 mm are provided at a position 7 mm from the tip opening 3 a at equal intervals in the circumferential direction of the mandrel 3.
Four through-holes 5, 5 are also provided at a position 15 mm from the front end opening 3a so as to be staggered with respect to the above position.

The resin which is melt-pressed by the screw and becomes the coating material 13A has a part of the core metal 3 through the respective through holes 5,5.
Before reaching the tip opening 3a of the mandrel 3, a thin coating made of the coating material 13A is formed on the surface of the support wire 12. This coating acts as a kind of lubricant.

This coating prevents the plating layer from peeling even at the contact portion at the tip opening 3a where the inner diameter of the core metal 3 is the thinnest, and completely eliminates the problem of non-extrusion due to clogging.

In the forming die portion 4a, a coating material 13A of the same material as the coating material is formed on the coating by extrusion extrusion coating as a common sheath 13, and a self-supporting communication cable 10 can be obtained. The adhesion of the common sheath 13 is not different from that in the conventional case, and there is no possibility that the problem of sheath peeling at the time of laying occurs.

Although the above description relates to the production of a self-supporting communication cable, the technical idea of the present invention is not limited to such production, but can be applied to all techniques for extrusion coating a metal-plated steel wire with a plastic resin. You can do it.

[Effects of the Invention] As described above, according to the apparatus and the manufacturing method according to the present invention, in the production of a self-supporting communication cable using a metal-plated steel wire as a support wire, the metal plating is peeled off and the mandrel caused by the metal plating is removed. Is completely eliminated, and smooth and stable continuous extrusion makes it possible to mass-produce high-quality products at high speed.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing a state in which a self-supporting communication cable is manufactured by a method according to the present invention using an apparatus according to the present invention, and FIG. 2 is a specific example of a support wire mandrel according to the present invention. FIG. 3 (a) is a sectional view of a self-supporting communication cable, and FIG. 3 (b) is an explanatory front view of a state in which the cable is stripped. 1: Mandrel, 2: Cable core mandrel, 3: Support wire mandrel 3a: Tip opening, 4: Cap, 4a: Molding die, 5: Through hole, 10: Self-supporting communication cable, 11: Cable core , 12: support wire, 13: common sheath, 13A: covering material.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Akira Shoji, Inventor 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture Inside Hidaka Works, Hitachi Cable Co., Ltd. (72) Mitsuo Yashiro Hidaka-cho, Hitachi City, Ibaraki Prefecture 5-1-1, Hidaka Electric Cable Co., Ltd. Hidaka Factory

Claims (2)

(57) [Claims] 1. A support wire guide and a position setting are performed by a support wire mandrel installed in a cross head of an extruder, and a cable core is guided and set by a cable core mandrel. In a device configured to be guided to a forming die portion of a base and to be capable of extruding and covering a common sheath on the outer periphery of the support wire and the cable core, a part of the coating material is placed on the support wire before the front end opening of the support wire mandrel. An apparatus for manufacturing a self-supporting communication cable, wherein a plurality of through-holes that can flow into a communication cable are formed in a staggered arrangement. 2. A plurality of through holes formed in a staggered arrangement in the support wire mandrel before the support wire reaches the tip opening of the support wire mandrel using the apparatus according to claim 1. A self-supporting type in which a part of the coating material flows into the outer periphery of the support wire and a coating of the inflow material is formed on the surface of the support wire, and in this state, the original coating layer is extruded by passing through the tip opening of the mandrel. Manufacturing method of communication cable.