JPS6037611A - Apparatus for producing plastic double insulated wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Background and Objectives of the Invention] The present invention relates to an apparatus for manufacturing a plastic double-insulated core wire,
In particular, the present invention relates to an apparatus for manufacturing a plastic double insulated wire in which double insulation of a foam layer and a solid layer is applied on a conductor.

It is well known that the transmission characteristics of communication cables, such as plastic double-insulated wires, are generally improved by foaming the foam insulation, but foam insulation and foaming the edges improve mechanical and mechanical properties. Electrical characteristics deteriorate. For this reason, it is necessary to coat the foam layer made of this foamed insulator with solid tin, but if the solid layer has uneven thickness, there is a risk of dielectric breakdown from the thin part. It is desirable to coat a uniform layer 7.5 with no uneven thickness.

By the way, this type of plastic double-insulated core wire is manufactured using a cassette-type crosshead as shown in Figure 1, which forms a foam layer that is extruded by a first extruder (not shown). The foamed material enters from the foamed insulator inlet 1 and flows from the nipple 2 to the die 3. And 4!
The solid layer forming solid layer is extruded by an extruder (not shown) from the connecting pipe 4 through the cartridge) 5 and reaches the distributor 6, where pressure is applied to the die 3 and the artificial or foamed insulator. It flows back towards the foam insulation and joins with the foam insulation.
After merging, the foamed insulator and resin are extruded as one through the die 3, and a plastic layer 8 and a solid layer 9 are formed on the conductor 7 as shown in FIG. Double insulated core wire is pushed out.

The distributor 6 for distributing and merging the resin into the foamed insulator has a cylindrical shape as shown in FIG. Although part J1 is used, this annular gap 10 is
1) 5) (see Figure 1). By the way, since the shape of the outlet part 11 of the conventional distributor 6 is a chi-shaped shape instead of a straight one, the resin flow is uneven and the pressure becomes unbalanced with respect to the circumference. ,
Unbalanced thickness occurs in the solid layer 9 (see Figure 2), causing 'electrical and
The mechanical properties were reduced.

The present invention has been made in view of the above points, and it is an object of the present invention to provide an apparatus for manufacturing a plastic double-insulated core wire, which makes it possible to prevent uneven thickness of the glued layer.

[Summary of the invention]

That is, the present invention provides a solid layer that is extruded in a first extruder and is coated/formed on a conductor, which is a foam insulator, and is extruded in a second extruder and covered/formed on a foam layer. Manufacturing of a plastic double insulated electric wire, which is equipped with a distributor for distributing and merging the resins, the distributor having a cylindrical shape, and having an outlet section at its outer peripheral end forming an annular gap from which the resin is jetted out. The device is characterized in that the outlet portion is formed by a weir provided at the outer circumferential end of the distributor, and a semicircular ring-shaped groove is provided on the outer circumference of the distributor adjacent to the outlet. The groove collects the resin from the distributor, and the weir uniformly squirts the resin collected in the groove from an annular gap on its outer periphery.

[Actual price cut]

The present invention will be explained below based on the illustrated embodiments. 4 and 5 show one embodiment of the present invention. Note that the same parts as in the prior art have been given the same reference numerals as fd, so their explanation will be omitted. In this example, the outlet portion is formed by a weir 12 provided at the outer peripheral end of the distributor 6a, and a semicircular ring-shaped groove 13 is provided on the outer periphery of the distributor 6a adjacent to the weir 12. By doing this, the resin supplied to the distributor 6a can be uniformly ejected from the annular gap 10a on the outer periphery of the weir 12 via the groove 13 and the weir 12, and can be merged with the foamed insulator. , it is possible to obtain a manufacturing apparatus for plastic double insulation In which can prevent uneven thickness of the solid R layer.

In other words, the connecting tube is extruded by the second extruder, and the force is
(See FIG. 1) The resin □ is supplied to the supply section A of the distributor 6a. The resin supplied to the supply part A flows from the supply part A to the branch part mouth as shown by the arrow in the figure, is divided into two equal parts at 180° at the branch part mouth, and is divided into two equal parts at the branch part mouth. The resin flows back, is further branched at 90° at branching part C, and then branched at branching part 2. In other words, the resin supplied to the supply part A is branched in order at the branch part port, C, and 2, and then sent to the distributor 6.
It is divided evenly around the circumference of a. In this way, the distributor 6
Since the resin is distributed evenly around the circumference of the distributor 6a, it is made to flow into the semicircular ring-shaped groove 13, so that the resin that is evenly divided by the groove 13 is collected and distributed uniformly around the entire circumference of the distributor 6a. The resin becomes dispersed and becomes uniform all around the circumference, and is jetted out from the annular gap [Oa] on the outer circumference of the weir 12, so that the resin flows from the annular gap 10a with uniform pressure all the way around and increases the flow rate. It reaches the inlet section 14 and merges with the foam insulation. In this way, the resin supplied to the distributor 6a is ejected from the annular gap 10a at the outer peripheral end of the distributor 6a with uniform pressure all around the circumference and merges with the foamed insulator, so that the resin is formed of the foamed insulator. The resin formed on the foam layer can be made to have a uniform thickness without uneven thickness, and the electrical and mechanical properties of the plastic double-insulated core wire can be improved. .

〔Effect of the invention〕

As described above, the present invention enables the resin supplied to the distributor to be discharged from the annular gap on the outer peripheral end of the distributor with uniform pressure all around, thereby reducing the nozzle formed by the resin. It is now possible to make the P layer without uneven thickness, and it is possible to obtain an apparatus for manufacturing a plastic double insulated wire that can prevent uneven thickness of the soliso P layer.

[Brief explanation of the drawing]

Figure 1 is a longitudinal cross-sectional side view of a cassette-type crosshead of a plastic double insulated wire manufacturing device, Figure 2 is a sectional view of a plastic double insulated wire manufactured by a plastic double insulated wire manufacturing device, and Figure 3 is a conventional FIG. 4 is a vertical sectional side view of the distributor of the plastic double insulated wire manufacturing apparatus of the present invention, and FIG. 5 is the plastic double insulated wire of the present invention. FIG. 2 is a perspective view of a distributor of an electric wire manufacturing apparatus. 1. Foamed insulator artificial part, 3..-Dice, 4.. Connecting pipe, 5.) 1) Horn, 6a Distributor, 7..
・Conductor, 8 ・Foam 1*, 9 Norisode layer,] Oa
--11i-shaped gap, 12 weir, 13... semicircular ring-shaped farm.

Claims (1)

[Claims] 1. The foam insulator of the foam layer extruded by the first extruder and coated/formed on the conductor is extruded by the second extruder and covered/formed on the foam layer.
The plastic double layer is equipped with a distributor for distributing and merging the resins of the layers, the distributor having a cylindrical shape, and having an outlet part formed at the outer peripheral end thereof to form an annular gap through which the resin is jetted out. In the insulated wire manufacturing equipment, the outlet part is
It is formed by a weir provided at the outer peripheral end of the 1S distributor, and
An apparatus for manufacturing a plastic double insulated wire, characterized in that a semicircular ring-shaped groove is provided on the outer periphery of the distributor adjacent to the weir.