JP2781007B2 - Manufacturing method of grooved rod - Google Patents

Description

The present invention relates to a method for manufacturing a grooved rod.

[Conventional technology]

First, a grooved rod to be manufactured by the method of the present invention will be described with reference to FIG. That is, as shown in FIG. 2, the grooved rod is formed by extruding an inner layer 2 made of a synthetic resin such as polyethylene around a tension member 1 which is a steel single wire or a steel stranded wire, and forming an outer layer 3 around the inner layer 2. A plurality of, in the example shown, four optical fiber storage grooves 31 are formed in the outer peripheral portion of the outer layer 3 in a spiral shape. Although not shown, an optical fiber is arranged in the optical fiber storage groove 31.

Numeral 32 indicates a colored marker line also formed by extrusion.

A conventional method for producing such a grooved rod will be described with reference to an apparatus shown in FIG.

The steel single-wire or steel-stranded tension member 1 continuously fed from the delivery device 4 is sent to a preheating device 101 by a caterpillar-type feeding device 5 for suppressing pulsation, where the tension member 1 is preheated. The inner layer 2 made of a synthetic resin such as polyethylene is formed on the periphery by being sent to 102.

The tension member 1 around which the inner circumference 2 is formed is cooled by the cooling water tank 103 and then sent to the outer layer extruder 7 where the outer layer 3 is formed around the inner layer 2. At this time, a die (not shown) is extruded while being rotated, thereby forming a spiral optical fiber storage groove 31. Subsequent to the outer layer extruder 7, a small extruder 8 is provided, which is a grooved rod optical fiber storage groove.
This is for extruding a colored marker line in the middle of 31.

The grooved rod manufactured as described above is measured by the measuring device 9 for the width, depth, pitch, and the like of the optical fiber storage groove 31, and is then taken by the take-off track device 10 and passed through the dancer roller device 11 to take up the device. It is wound on 12.

[Problems to be solved by the invention]

In the conventional method, since the inner layer 2 formed around the tension member 1 is formed by extruding a synthetic resin, the outer diameter varies relatively greatly. As a result, when the outer diameter dimension increases, the outer layer extruder 7 There is a possibility that inconvenience such as the nipple 71 may be used.

[Means for solving the problem]

The present invention has been made to solve the above-mentioned problem, and has an inner layer formed around a tension member, and a plurality of spiral light beams is formed around the inner layer while rotating an extrusion die around the inner layer. In a method for manufacturing a grooved rod in which an outer layer provided with a fiber housing groove is formed by extrusion, an inner layer material having a controlled outer diameter is formed by electrostatically applying an inner layer material around the tension member. The manufacturing method of the grooved rod described above.

[Action]

Since the inner layer is formed by electrostatically applying the inner layer material on the tension member, the outer diameter of the inner layer can be uniform, and the outer diameter can be accurately controlled. Is eliminated.

〔Example〕

The method of the present invention will be described with reference to FIG. 1 showing an example of an apparatus for carrying out the method of the present invention. In FIG. 1, the same reference numerals are used for the same devices as those in FIG. 3 showing an example of a conventional device, and the description thereof will be omitted.

A feature of the present invention is that the inner layer 2 formed around the tension member 1 is formed by an electrostatic coating method.

That is, reference numeral 6 in FIG. 1 shows an example of an electrostatic coating device for this purpose. The tension member 1 as an object to be coated is provided with a positive dust collecting electrode via an electrode roller 61 which guides the traveling thereof. A grid 62 as a negative discharge electrode is provided so as to surround the running line of the tension member 1.
By spraying the molten liquid of the inner layer material resin derived from 63, the molten resin adheres uniformly to the outer peripheral surface of the tension member 1 and the inner layer 2 is formed.

Alternatively, fine powder of the inner layer material may be adhered to the outer periphery of the tension member 1 instead of spraying the melt.

If the thickness of the inner layer 2, that is, the outer diameter dimension after the electrostatic coating, is determined experimentally once based on the applied voltage, the size of the grid, etc., relatively accurate management becomes possible thereafter.

After the inner layer 2 is formed in this way, the process proceeds to the outer layer extruder 7, and the same steps as in the conventional method are performed.

〔The invention's effect〕

According to the present invention, since the inner layer provided around the tension member is formed by an electrostatic coating method using a melt of the inner layer material resin, the dimensions are accurately formed with a uniform thickness on the outer periphery of the inner layer tension member. Therefore, there is no inconvenience such as being used for the nipple of the outer layer extruder in the next step, and the outer diameter of the grooved rod as a product is accurately finished, and the production efficiency is greatly improved.

[Brief description of the drawings]

FIG. 1 is a simplified diagram showing an example of an apparatus for carrying out the method of the present invention, FIG. 2 is a perspective view showing a grooved rod, and FIG. 3 is a simplified diagram for explaining a conventional method. 1 ... tension member, 2 ... inner layer, 3 ... outer layer, 4 ... sending device, 6 ... electrostatic coating device, 7 ... outer layer extruder.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02B 6/44 391

Claims (1)

(57) [Claims] 1. An inner layer (2) around a tension member (1).
And a grooved rod for extruding an outer layer (3) provided with a plurality of spiral optical fiber storage grooves (31) on the outer periphery thereof while rotating an extrusion die around the inner layer (2). In the manufacturing method, the tension member (1)
A method for manufacturing a grooved rod, comprising forming an inner layer (2) having a finished outer diameter controlled by electrostatically applying an inner layer material around the groove.