JPS63308806A - Light electric wire/cable - Google Patents

Abstract

PURPOSE:To obtain an electric wire/cable which is light and excellent in connection by providing a Ag layer round an Al cable. CONSTITUTION:An Ag layer is made, in the thickness of about 5-25% of the sectional area of the line material, round an Al cable. For example, an Ag pipe is provided round the Al cable and then the diameter is made thin by the lubricating extrusion method, etc, and controlled to pull out as occasion demands. Since Al and Ag generate intermetallic compound at about 200 deg. and the conductivity lowers, in case of heat resistance application, three-layer structure in which especially Cu unit is laid between will be effective to prevent reactive diffusion. If a conductor element wire in this constitution is used, the conductor connectability is excellent and a light electric wire/cable which has large lightening effect can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to lightweight electric wires and cables suitable for applications that require light weight, such as power cables for artificial satellites.

[Prior Art] Copper or copper alloy materials have been used as conductor materials for conventional power cables and the like. Although these materials have high conductivity and high strength, their specific gravity is as high as 8.9, making them unsuitable for applications that require light weight, such as artificial satellites, and even lighter materials are desired.

Aluminum has a low electrical conductivity of about 60% of copper, but its specific gravity is about 30% of copper, and to obtain the same DC electrical resistance as copper, it must weigh about 1/2 of copper, and its lightweight effect is extremely low. big.

[Problems to be Solved by the Invention] However, aluminum has problems in connection, especially when 0.
In the case of a conductor made by twisting strands of wires with a diameter of 1 to 0.2 mm, a special connection process is required, which poses problems in terms of stability and workability of the connection part.

The present invention has been made based on the above, and aims to provide lightweight electric wires and cables that have good conductor connectivity and are highly effective in reducing weight.

[Means for Solving the Problems] The lightweight electric wire/cable of the present invention is characterized in that the conductor element wire is a wire formed by providing a silver layer on the outer periphery of an aluminum wire.

By forming a silver layer on the outer periphery in this manner, solderability is greatly improved, and it is also possible to lower the resistance of the connection portion using the crimp terminal.

The thickness of the silver layer is not particularly limited, but is between 5 and 25% of the cross-sectional area of the wire.
It is preferable to set the thickness to about %.

As a method for manufacturing a wire having a silver layer on the outer periphery of an aluminum wire, for example, a composite billet is created by providing a silver pipe on the outer periphery of an aluminum rod, and the diameter of this is reduced by a method such as hydrostatic extrusion or lubricated extrusion. , and further perform a pulling operation as necessary, but the method is not limited thereto.

Note that aluminum and silver are highly reactive materials, and easily form intermetallic compounds at a temperature of around 200° C. at the bonding interface. When this intermetallic compound grows, electrical conductivity decreases and mechanical strength, especially elongation, decreases. Therefore, in heat-resistant applications, it is preferable to have a three-layer structure in which a metal layer is interposed between the aluminum wire and the silver layer to prevent their reaction and diffusion. Examples of metals that prevent reaction diffusion between aluminum and silver include transition metals such as copper, iron, nickel, and chromium, or their alloys.
Copper is most preferred in terms of workability and electrical properties.

In the present invention, aluminum, silver,
Of course, copper may be a single metal or an alloy.

[Examples of the Invention] Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples.

FIG. 1 is an explanatory cross-sectional view of one embodiment of the wire of the present invention, which is constructed by providing a silver layer 2 on the outer periphery of an aluminum wire 1 (Ag/At wire).

FIG. 2 is an explanatory cross-sectional view of another embodiment of the wire rod of the present invention, which is constructed by sequentially providing a copper layer 23 and a silver layer 22 on the outer periphery of an aluminum wire 21 (Ag/Cu/
Al line).

For the Ag/At wire, the outer diameter is 0.241 mmφ (the thickness of the silver layer 2 is 9 μm), and the outer diameter is 0.15 mmφ (the thickness of the silver layer 2 is 6 μm).
m), three types of wire rods with an outer diameter of 0.12 mmφ (thickness of the silver layer 22 5 μm) were manufactured, and for the Ag/Cu/A1 wire, the outer diameter was 0.241 mmφ (thickness of the silver layer 22 6.4 μm, Two types of wire rods were manufactured: one having a diameter of 0.15 mm (the thickness of the copper layer 22 was 4 μm and the thickness of the copper layer 23 was 2 μm).

Each of the above-mentioned wires is twisted into 19 conductor wires, and a laminate tape of polyimide and FEP (polyimide/FEP
EP tape) is wound in one layer to make an insulated core wire, and a conductor element wire with an outer diameter of 0.15 mmφ is braided around the outer circumference of the 4-core twisted insulated core wire, and two layers of polyimide/FEP tape are further wound around the outer circumference. By rotating, a lightweight power cable with an outer diameter of 4.5 mm was manufactured.

Table 1 shows various characteristics of the lightweight power cable manufactured as described above. For comparison, the characteristics of power cables manufactured using electrical aluminum and electrical copper as conductor strands are also listed.

From Table 1, the conductivity, specific gravity, and mechanical properties of Ag/A1 wire and Ag/Cu/Al wire are intermediate between those of Al wire and Cu wire, and when the DC electrical resistance is equivalent, Cu
It can be seen that the light weight effect is approximately 30% that of the wire. Furthermore, the connectivity was evaluated based on solderability and connection resistance using crimp terminals, and the A1 wire had poor workability and high connection resistance.

Figure 3 shows the Ag/A1 line and the Ag/Cu/
A Ag/Al interface and Cu/ when heating 1 wire
This figure shows the change in the thickness of the intermetallic compound layer formed at the Al interface depending on the heating temperature. Ag if below 200℃
The thickness of the alloy layer at the /Al interface is 1 μm or less, which is not a problem. In the case of Ag/Cu/A1 wire, 35
It is 1 μm or less even at 0° C., and is excellent in terms of heat resistance.

[Effects of the invention] As explained above, according to the present invention, it is possible to realize electric wires and cables that have good conductor connectivity and are expected to be 30% lighter than when using copper wires, and are It can be said to be extremely effective for power cables for satellites, aircraft, etc.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional explanatory diagram of one embodiment of the wire rod of the present invention, FIG. 2 is a cross-sectional explanatory diagram of another embodiment of the wire rod of the present invention, and FIG.
3 is a graph showing the relationship between the thickness of a compound layer generated at the g/Al interface and the Cu/'AI interface and the heating temperature. 1.21 Nialuminum wire 2.22: Silver layer 23: Copper layer Figure 1 Figure 2

Claims (3)

[Claims] (1) A lightweight electric wire/cable characterized in that the conductor element is a wire material made by providing a silver layer on the outer periphery of an aluminum wire. (2) The lightweight electric wire/cable according to claim 1, wherein the wire is an aluminum wire with a silver layer directly provided on its outer periphery. (3) The lightweight electric wire/cable according to claim 1, wherein the wire has a metal layer provided between the aluminum wire and the silver layer to prevent reaction and diffusion thereof.