JPH04124713U - insulated wire - Google Patents

Abstract

(57) [Summary] [Purpose] An insulated wire that does not cause a disconnection accident when extruded and coated with an insulating layer is provided. [Structure] An insulated wire consisting of a stranded conductor 2 formed by twisting a plurality of strands 1 and a foamed plastic insulation layer 4 extruded and coated on the outer periphery of the stranded conductor 2. Plastic fibers 3 having a melting point higher than the temperature at which the foamed plastic insulator is extruded and coated on the outer periphery
Insulated wires with . [Effect] Since the plastic fibers reinforce the stranded conductor, the stranded conductor will not break during extrusion coating.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to insulated wires, and more specifically, to prevent wire breakage during manufacturing. Stable production is possible, and the conductor does not come apart even if the insulating layer is removed during actual use. Concerning insulated wires that never get damaged.

0002

[Conventional technology]

High-speed transmission lines for general-purpose computers and wires for ultrasonic probes are usually used for signal transmission. A small-diameter multicore coaxial cable is used. These cables are generally made by twisting multiple strands of wire with a specified wire diameter to form a stranded conductor. Then, a foaming agent is applied to the outer periphery of this stranded wire conductor, such as plastic such as fluororesin. This is then extruded and coated to create a structure with a foamed plastic insulation layer. ing.

0003

[Problem that the idea aims to solve]

By the way, in the case of the above-mentioned cables, recent efforts have been made to reduce their diameter and increase their functional speed. Needs are increasing. For example, for signal transmission cables, 32AWG There is a demand for 36AWG class products, and there are also demands for ultrasonic printers. Lobe cables use ultra-thin diameter conductors of 7/0.03 to improve resolution. A request has been made to develop a multicore coaxial cable consisting of a multi-core coaxial cable.

0004 However, if the above-mentioned fluororesin containing a foaming agent is continuously applied to such a small-diameter conductor, If the extrusion coating is carried out using extrusion coating, conductor breakage may occur during the extrusion coating process, resulting in damage to long products. It becomes difficult to produce stably. In order to prevent such conductor disconnection accidents, Cu-Sn alloy, The breaking strength of conductors has been increased using alloy wires such as Cu-Cr alloys. It is.

[0005] However, all of these alloy wires have higher performance than pure annealed copper wire. Since the conductivity is approximately 10% lower, the amount of attenuation as a cable increases, making it difficult to use in practice. It is inconvenient for use. This invention solves these problems and provides continuous and stable operation without disconnection accidents. The purpose is to provide insulated wires that can be produced.

[0006]

[Means to solve the problem]

In order to achieve the above purpose, in this invention, multiple strands are twisted together. a stranded conductor wire, and a foamed plastic insulation coated on the outer periphery of the stranded conductor wire by extrusion. In the insulated wire consisting of an edge layer, the foamed plastic is applied to the outer periphery of the stranded conductor. Place plastic fibers with a melting point higher than the temperature at which the extruded insulation is coated. An insulated wire is provided.

[0007]

[Effect]

Plastic fibers placed along the outer circumference of the stranded conductor strengthen the stranded conductor. Therefore, the combined breaking strength of the stranded conductor and plastic fiber is It is stronger than a hanging or stranded conductor alone. Therefore, on these outer peripheries When extrusion coating foamed plastic, disconnection accidents of stranded wire conductors will no longer occur.

[0008] Also, when attaching this wire to the connector, the foam plastic insulator is removed. At the time of laser cutting, the plastic fibers are cut at the same time as this foamed plastic insulation layer. It can also be cut and easily removed.

[0009]

【Example】

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view showing an example of the insulated wire of the present invention. In the figure, multiple (seven in the figure) strands 1 are twisted together in the longitudinal direction to form one wire. A stranded conductor 2 is formed.

0010 A plurality of wires (in the figure, 6 The plastic fibers 3 of A foamed plastic insulator layer 4 is formed by extrusion coating the block. Here, the plastic constituting the plastic fiber 3 is a foamed plastic A plastic having a melting point higher than the molding temperature at the time of extrusion coating of the edge layer 4 is used. used.

[0011] Specifically, the foamed plastic insulation layer is coated with a fluororesin, such as tetrafluorocarbon resin. Made of polyethylene/perfluoroalkyl vinyl ether copolymer foam. In this case, the plastic fiber 3 is, for example, para-type wholly aromatic polyamide fiber ( It is preferable to use Kepler (trade name: Kepler). In this case, the wire diameter of the Keplerian fiber is , is preferably 1/2 or less of the wire diameter of the strand 1 used.

0012 For example, make a bundle of 7 silver-plated copper wires 1 with a wire diameter of 0.05 mm, and put a wire with a wire diameter of 0.05 mm on the outside. Arrange six 02mm Kepler fibers and twist them all together, and in this state, make a twisted wire conductor. is placed on the extrusion coating line, and the entire outer circumference is covered with tetrafluoroethylene perfluoroethylene. Foamed plastic with a thickness of 0.2 mm is extruded and coated with a lo-alkyl vinyl ether copolymer. Then, an insulator layer 4 was formed. Even with 5000m of continuous coverage, stranded conductors only break once. There were no accidents.

[0013] However, when similar extrusion coating was performed without Kepler fibers, several hundred to A wire breakage accident always occurred at least once during an extrusion length of 2000 mm. In addition, when the insulator layer of the obtained insulated wire of the present invention was removed by laser cutting, Kepler fibers were also removed smoothly, and no breakup occurred between the strands. Next, the effect will be explained.

[0014] The plastic fibers 3 are arranged along the outer periphery of the stranded conductor 2 in the longitudinal direction. Therefore, if you extrude and cover the outer periphery of these with foamed plastic that will become an insulating layer. Even if the stranded conductor 2 is bent, the plastic fibers exert a reinforcing effect and the disconnection accident of the stranded conductor 2 does not occur. It disappears. In addition, the insulating layer 4 is made of tetrafluoroethylene/perfluoroalkyl vinyl. -Tel copolymer foam, when the plastic fiber 3 is Kepler fiber When attaching the edge wire to the connector, if the insulator layer 4 is cut with a laser, Kepler The thermal decomposition temperature of the fiber is 430 to 450°C, which is approximately the same as that of the foam of the insulating layer. Therefore, it is possible to simultaneously cut the insulator layer 4 and the Keplerian fiber.

[0015] Furthermore, when cutting this insulator layer 4, the plastic disposed on its outer periphery is Since the fibers 3 and the insulating layer 4 have good slippage and the adhesion between them is low, the stranded wire conductor 2 is Rake will no longer occur.

[0016]

[Effect of the idea]

As is clear from the above explanation, the insulated wire of the present invention is made by twisting multiple wires together. a stranded conductor wire, and a foamed plastic insulation coated on the outer periphery of the stranded conductor wire by extrusion In the insulated wire consisting of a body layer, the foamed plastic Plastic fibers with a melting point higher than the temperature at which the insulation is extruded are placed. This feature makes it possible to reinforce stranded conductors when plastic fibers are extruded and coated. It functions as a material, prevents wire breakage accidents during extrusion coating, and enables stable production. Also Even when cutting the insulator layer with a laser, the stranded conductor does not come apart, and the terminal workability is extremely high. It is in good condition.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of the cross-sectional structure of an insulated wire according to the present invention.

[Explanation of symbols]

1 Element wire 2 Stranded conductor 3 Plastic fiber 4 Foamed plastic insulation layer

Claims (2)

[Scope of utility model registration request] 1. An insulated wire comprising a stranded conductor made by twisting a plurality of wires together, and a foamed plastic insulation layer extruded and coated on the outer periphery of the stranded conductor, wherein An insulated wire, characterized in that plastic fibers having a melting point higher than the temperature at which the foamed plastic insulator is extruded and coated are disposed therein. 2. The plastic fiber is a para-type wholly aromatic polyamide fiber having a diameter of 1/2 or less of the diameter of the wire, and the foamed plastic insulating layer is made of tetrafluoroethylene perfluoroalkyl vinyl ether. The insulated wire according to claim 1, which is a copolymer foam.