JP2022171278A - Composite electric wire and method for manufacturing the same - Google Patents

Abstract

To obtain a composite electric wire rich in electric conductivity and large in plasticity.SOLUTION: A composite electric wire having an outer diameter of approximately 500 μm includes: a coated layer 3 provided to surround a central core wire 2; a conductive layer 4 arranged around the coated layer 3; and an insulating coating layer 5 provided around the conductive layer 4. The core wire 2 is formed by twisting four middle wires 2a-2d; each of the middle wires 2a-2d is formed by twisting a single wire consisting of, for example, 48 aramid fibers; the diameter of the single wire is, for example, 12 μm; the diameter of the core wire 2 is approximately 200 μm; 12 copper wires 4a having a diameter of 80 μm are spirally and closely wound around the core wire 2 as the conductive layer 4; the periphery of the copper wire 4a is shaped into a circle by tightening; and the periphery of the copper wire 4a is covered with a tin layer 4b formed of a low melting metal and having a thickness of several μm.SELECTED DRAWING: Figure 1

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite electric wire that can be suitably used for a small-diameter crimp connection terminal and a method for manufacturing the composite electric wire.

2. Description of the Related Art In recent years, there has been a strong demand for lighter and smaller parts used in, for example, various electrical devices. With regard to signal wiring, as many sensors and the like are used, the number of signal wiring also increases, and further miniaturization of the electric connector for connecting the wiring is required.

In order to reduce the size of the electrical connector, it is necessary to reduce the size of the connecting terminal used in the electrical connector and to reduce the diameter of the electric wire. Recently, connection terminals with a connection diameter of 1 mm or less have begun to be used, and electric wires with a diameter of about 0.5 mm are required.

For this reason, so-called fiber electric wires, which are less likely to be cut even if the diameter is reduced, are sometimes used instead of conventionally used copper wires. However, the fiber electric wire itself as a conductor is composed of a plurality of strands, has poor plasticity, and is easy to come apart, making it difficult to crimp to a crimp connection terminal.

Patent Document 1 discloses a metal-coated carbon fiber electric wire in which an underlying metal layer and a single-layer or multiple-layer metal layer are formed on an upper layer of conductive carbon fibers. This electric wire can also be reduced in diameter, but the manufacturing method and structure are complicated.

JP 2012-216526 A

From such a technical background, there is a demand for a small-diameter electric wire that has a simple structure, is rich in conductivity and plasticity, and can be suitably crimped to a crimp connection terminal.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide a composite electric wire and a composite electric wire having a predetermined function such as electric conductivity and plasticity, etc., by coating a conductive metal wire with a low-melting metal. An object of the present invention is to provide a method for manufacturing a composite electric wire.

A composite electric wire according to the present invention for achieving the above object is a composite electric wire comprising a core wire made of synthetic resin fiber, a synthetic resin coating layer surrounding the core wire, and a conductive layer provided around the coating layer. wherein the conductive layer is a low-melting-point metal having a melting point lower than that of the conductive metal wires, which adheres the plurality of conductive metal wires and adjacent wires of the conductive metal wires and covers the outer surfaces of the conductive metal wires. All the conductive metal lines are in close contact along the surface of the coating layer, and the conductive layer covers the periphery of the coating layer without gaps.

A method for manufacturing a composite electric wire according to the present invention is a method for manufacturing a composite electric wire in which a conductive layer is provided around a core wire made of synthetic resin fibers, in which a coating step of providing a coating layer made of a synthetic resin material around the core wire. a metal wire winding step of closely following all of the plurality of conductive metal wires on the surface of the coating layer; a metal wire cleaning step of cleaning the wound conductive metal wires; By dipping in a molten low-melting-point metal, the outer surface is plated with the low-melting-point metal, and a conductive layer in which adjacent wires of the conductive metal wires are bonded by the low-melting-point metal is formed around the coating layer. and a metal wire plating process to cover the with no gaps.

According to the composite electric wire and the manufacturing method of the composite electric wire according to the present invention, a synthetic resin coating layer is provided around a synthetic resin core wire, and adjacent wires made of conductive metal wires are attached to each other by a low-melting metal on the upper layer. By arranging a well-adhered conductive layer, it has high electrical conductivity, high plasticity, small diameter, good connection with a crimp connection terminal, and easy production.

1 is a cross-sectional view of a composite electric wire of an example; FIG. It is a schematic diagram of a manufacturing process of an example. It is sectional drawing of the state which made the copper wire run along the core wire at the film layer. FIG. 4 is a perspective view showing a state in which a copper wire is laid along a core wire on a coating layer. It is sectional drawing of the state which shaped the copper wire. FIG. 3 is a cross-sectional view of a copper wire covered with a plated layer; FIG. 4 is a cross-sectional view of a composite electric wire that does not undergo a metal wire shaping process;

The present invention will be described in detail based on the illustrated embodiments.
FIG. 1 is a cross-sectional view of a composite electric wire 1 according to an embodiment. In the composite electric wire 1, a coating layer 3 is provided around a core wire 2, a conductive layer 4 composed of a copper wire 4a and a tin layer 4b is arranged on the outside thereof, and an insulating coating layer 5 is further provided around the conductive layer 4. It is provided and has flexibility as a whole.

The core wire 2 is made by twisting four medium wires 2a to 2d, for example, and each of the medium wires 2a to 2d is made by twisting polymer filaments made of a synthetic resin material, for example, 48 aramid fibers. The diameter of these strands is, for example, 12 μm, and the diameter of the core wire 2 is approximately 200 μm. In addition, the above-mentioned aramid fiber has properties of being lightweight, having high strength, and having high flexibility, and having no electrical conductivity.

A coating layer 3 is provided around the core wire 2. The coating layer 3 is made of polyester resin, for example, and has a thickness of several μm.

The conductive layer 4 includes a conductive metal wire having a high melting point, such as a copper wire (Cu: melting point of 1085° C.) 4a, and adjacent wires of the copper wire 4a are adhered to each other and the outer surface of the copper wire 4a is covered. It is composed of a low melting point metal, such as a tin layer (Sn: melting point 232° C.) 4b.

The copper wires 4a have a diameter of 80 μm, for example all 12 copper wires 4a are tightly wound around the coating layer 3 in a helical manner. Tin, which is a low melting point metal, is melted and welded to the surface of the copper wire 4a, that is, the copper wire 4a is plated with tin, and adjacent wires of the copper wire 4a are bonded together as a tin layer 4b. Moreover, the surface of the copper wire 4a as a whole is shaped into a circle as necessary. In the examples, the low melting point is based on the temperature at which the low melting point metal melts in the plating tank to be described later.

The insulating coating layer 5 is formed of a soft synthetic resin material such as polyester having electrical insulation, covers the upper layer of the conductive layer 4, and has a thickness of, for example, 50 μm. is about 500 μm in diameter.

As shown in FIG. 2, the composite electric wire 1 is manufactured by a coating step A of applying a coating layer 3 around the core wire 2, a metal wire winding step B of further winding a copper wire 4a around it, A metal wire shaping process C for shaping the outer diameter of the wound copper wire 4a into a circular shape, a metal wire cleaning process D for cleaning the copper wire 4a, and a tin layer 4b is plated on the copper wire 4a to form a conductive layer 4. and a metal wire plating step E to cover the conductive layer 4 with an insulating coating layer 5 .

In the coating step A, the core wire 2 is submerged in a resin bath containing, for example, a melted polyester resin, and the coating layer 3 is applied around the core wire 2 . This coating layer 3 prevents a flux agent, which will be described later, from penetrating into the core wire 2 .

In the metal wire winding step B, as shown in FIGS. 3 and 4, for example, 12 copper wires 4a are spirally wound around the coating layer 3 by a winding machine. In the core wire 2, the middle wires 2a to 2d are loosely helically twisted, and the helix angle of the copper wire 4a is set larger than the angle of the middle wires 2a to 2d. The direction of the spiral of the copper wire 4a is different from the direction of the spiral of the middle wires 2a to 2d. Preferably, the directions of the helices are crossed. Although the copper wire 4a may be arranged along the longitudinal direction of the core wire 2, it is more robust if it is spirally wound.

In the next metal wire shaping step C, the surface of the copper wire 4a is shaped into a circular shape by tightening the surrounding copper wire 4a from the outside as shown in FIG. 5 using a shaping device such as a die.

Subsequently, in the metal wire cleaning process D, the copper wire 4a is passed through a cleaning bath containing a fluxing agent such as a strong acid solution, and the copper wire 4a is pickled with the fluxing agent so that the plating can easily adhere to the copper wire 4a in the next step. In this case, since the core wire 2 is covered with the coating layer 3 , the flux agent does not enter the core wire 2 .

Next, in a metal wire plating step E, the copper wire 4a is immersed in a plating bath in which tin (Sn), which is a low-melting-point metal, is molten. As shown in FIG. 6, the tin melted in the plating bath covers the surface of the copper wire 4a with a thickness of several μm and enters between the adjacent copper wires 4a to form a tin layer 4b on the outer surface of the copper wire 4a. Form. In this metal wire plating process E, since oil and the like have been removed from the copper wire 4a in the metal wire cleaning process D, a conductive layer 4 is obtained in which the copper wire 4a is well plated with the tin layer 4b. 4 covers the periphery of the core wire 2 without gaps. In this metal wire plating process E, since the melting point of tin in the plating bath is 232° C., the melting point of the coating layer 3 is about 250° C. when a polyester-based synthetic resin is used. will not be damaged.

In addition, as shown in FIG. 6, the composite electric wire 1 of the present invention can also be one in which the conductive layer 4 remains exposed on the surface.

Furthermore, in the insulation coating step F, the wire provided with the conductive layer 4 is passed through a coating molding machine, and the periphery of the conductive layer 4 is covered with an insulation coating layer 5 made of a synthetic resin material to form the composite wire shown in FIG. 1 is obtained.

Each of the above-described steps may be performed continuously on the same production line, or the next step may be performed after each step is once wound on a reel.

In the example, the composite electric wire 1 was manufactured through the metal wire shaping step C for the copper wire 4a. D, a metal wire plating step E, and an insulation coating step F may be performed. In this case, a composite electric wire 1 as shown in FIG. 7 is obtained.

As described above, the conductive layer 4 of the composite electric wire 1 manufactured in the example is composed of the tin layer 4b and the tin-bonded copper wire 4a. covered with Therefore, even if the insulating coating layer 5 is peeled off for crimping to the crimp connection terminal, the core wire 2 and the copper wire 4a are not separated. Moreover, since the copper wire 4a has good plasticity, it can be crimped by the crimping piece of the crimping connection terminal.

In the conductive layer 4, a conductive metal wire such as an aluminum wire can be used instead of the copper wire 4a. Also, instead of tin, which is a low-melting-point metal used to bond the copper wires 4a together, solder made of a similarly low-melting-point metal, such as a tin-zinc alloy (eg, a melting point of 180 to 220° C.) may be used.

1 Composite wire 2 Core wire 2a to 2d Middle wire 3 Coating layer 4 Conductive layer 4a Copper wire 4b Tin layer 5 Insulating coating layer A Coating process B Metal wire winding process C Metal wire shaping process D Metal wire washing process E Metal wire plating process F insulation coating process

Claims (10)

A composite electric wire comprising a core wire made of synthetic resin fiber, a synthetic resin coating layer surrounding the core wire, and a conductive layer provided around the coating layer,
The conductive layer comprises a plurality of conductive metal wires and a low-melting-point metal having a melting point lower than that of the conductive metal wires, which bonds adjacent wires of the conductive metal wires and covers the outer surfaces of the conductive metal wires,
A composite electric wire, wherein all of the conductive metal wires are in close contact along the surface of the coating layer, and the conductive layer covers the circumference of the coating layer without gaps. 2. The composite electric wire according to claim 1, wherein said conductive metal wire is spirally wound around said coating layer. 3. The composite electric wire according to claim 1, wherein the conductive layer has a circular outer periphery. 3. The composite electric wire according to claim 1, wherein said conductive metal wire is copper wire and said low-melting-point metal is tin. 3. The composite electric wire according to claim 1, wherein said conductive layer is covered with an insulating coating layer made of a synthetic resin material. 2. The composite electric wire according to claim 1, wherein the core wire is formed by twisting a plurality of synthetic resin fiber strands to form a medium wire, and further twisting the plurality of medium wires. In a method for manufacturing a composite electric wire in which a conductive layer is provided around a core wire made of synthetic resin fibers,
A coating step of providing a coating layer made of a synthetic resin material around the core wire;
a metal wire winding step of closely following all of the plurality of conductive metal wires on the surface of the coating layer;
a metal wire cleaning step of cleaning the wound conductive metal wire;
By immersing the conductive metal wire in a molten low-melting-point metal, the outer surface is plated with the low-melting-point metal, and the low-melting-point metal adheres adjacent wires of the conductive metal wire to form a conductive layer, A metal wire plating step for covering the periphery of the coating layer without gaps;
A method for manufacturing a composite electric wire, comprising: 8. The method of manufacturing a composite electric wire according to claim 7, wherein in the metal wire winding step, the conductive metal wire is spirally wound around the core wire. 8. The method of manufacturing a composite electric wire according to claim 7, wherein a metal wire shaping step of tightening the conductive metal wire and shaping it into a circular shape is provided after the metal wire winding step. 8. The method of manufacturing a composite electric wire according to claim 7, further comprising an insulating coating step of providing an insulating coating layer made of a synthetic resin material on the surface of the conductive layer after the metal wire plating step.

Images