JPH01225006A - Compressed conductor for wire harness - Google Patents

Abstract

PURPOSE:To make it possible to obtain a conductor high in circularity and superior in mechanical strength by making the hardness of a core elementary wire over that of the surrounding elementary wires and by compressing the assembly to become a circle in its profile. CONSTITUTION:A core elementary wire 1 consists of a single strand or twisted strands having a higher hardness and mechanical strength, and the surrounding elementary wires 2 twisted around it consists of a single strand or twisted strands having a less hardness than that of the core elementary wire 1, and when these twisted strands are compressed by restriction of a die, only the surrounding strands 2 undergo deformation, and the core elementary wire 1 with a higher hardness preserves its complete circularity in its profile. As a material for the core elementary wire with a higher hardness, stainless steel, copper alloy, etc., are desirable, a metal having a higher hardness is desirable, even if it has a more or less lower tolerance for current passage, and as a material for the surrounding elementary wires for example annealed copper for electric use, hardened copper for electrical use, or copper alloys should be used. As regards the shape of the elementary wires, both a single and twisted strands can be applied with profit. With this procedure it is possible to obtain a conductor high in circularity and thus to produce a strong wire harness owing to prominent strength of the core elementary wire.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a compressed conductor passing through the center of wire A7 of a wire harness for an automobile, for example.

(Prior Art) An automobile wiring harness is used to wire all of the automobile's electrical systems, and as automobiles become more sophisticated, the number of wiring harnesses is increasing and becoming more complex.

On the other hand, the eaves of the entire automobile are required to be made wider, the wire harnesses are also made thinner, and improvements in conductive f/I performance are expected.

In order to meet this demand, it has been known to circularly compress a conductor passing through the center of a wire harness (Japanese Unexamined Patent Publication No. 60-91573.Q).

FIG. 4 is a sectional view showing a conventional compressed conductor for a wire harness.

In Fig. 4, 1 is the center strand, 2 is the outer strand,
For all of these, single wires or stranded wires made of electrical soft copper or hard copper of the same quality are used. Initially, these strands have a circular cross section, and the outer strands 2 are twisted concentrically around the center strand 1, but when this is compressed into a circular shape by squeezing with a die, the space between each strand increases. The space 3- between the wire 3 and the insulating sheath is considerably smaller, making the wire thinner.

(Problem to be solved by the invention) As mentioned above, conventional compressed conductors are compressed and made smaller in diameter by narrowing the die, but since each strand uses a metal wire of the same quality, each strand can be It becomes deformed and deformed.

As a result, the following inconveniences occurred.

(1) Spaces 3, 3- are scattered between the strands and between the sheath and the strands due to deformation of the strands.

(2) Certain strands become extremely thin depending on the location, reducing electrical conductivity and strength.

(3) As the strands become irregularly shaped, the roundness of the entire conductor decreases.

(4) Electrical conductors have low strength and there is a limit to how thin they can be made.

Therefore, in the conductor of such a wire harness,
The challenge was how to create a material with high roundness, small space, and great strength even with a small diameter, and as a result, a thin insulating sheath.

(Means for Solving the Problems) In order to solve the above problems, the present invention takes the following measures.

That is, the compressed conductor for Wire A7 harness of the present invention uses a high hardness, high strength single wire or stranded wire as the center wire, and surrounds it in a concentric circle with an outer wire made of a solid wire or stranded wire with a lower hardness than the center wire. It is characterized by being twisted together in a circular shape and compressed into a circular shape.

The material of the high hardness, high strength central strand used in the present invention is preferably stainless steel, copper alloy, etc., and is preferably hard and strong even if the allowable current is reduced to some extent. In addition, the shape of the wire may be either a medium wire or a stranded wire.

The outer wire must be made of a material with lower hardness than the center wire, such as electrical mild steel, electrical hard copper, or copper alloy, but if copper alloy is used, the center wire must be harder than this. For example, use stainless steel. The shape of the outer wire can be either a single wire or a twisted wire.

(Function) Since the center strand in the present invention has higher hardness than the outer strand, when it is circularly compressed, only the outer strand deforms, literally overriding the action of the stationary center strand.

Furthermore, although the allowable current is slightly lowered by this central strand, since it is strong, it acts as a reinforcing wire that maintains its strength against external forces.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and is a sectional view of a compressed conductor for a wire-V harness.

The center strand 1 is a single wire with high hardness and high strength, and the outer periphery strand 2 twisted around it is a single wire with lower hardness than the center strand 1. Although this stranded wire is compressed by squeezing with a die, only the peripheral outer strands 2 are deformed, and the highly hard central strand 1 maintains a perfect circle in cross section. As a result, the space 3.3' becomes extremely small, and the cross section as a whole forms a perfect circle.

Example 1 Compressed conductors of various conductor external shapes were made using a stainless steel wire as the central strand, and the relationship between the conductor diameter and breaking load was investigated, and the results are shown in FIG. For comparison, data are also shown for those without compression and those with annealed copper wire as the center strand.

In FIG. 2, the symbol [] indicates the following sample.

a... 1 stainless steel wire 6 circular compressed copper alloy wires b... 1 stainless steel wire 6 circular compressed electrical annealed copper wires C... 1 electrical annealed copper wire Circular work 1゛! 6 compressed electrical annealed copper wires d... 1 electrical annealed copper wire 6 uncompressed electrical annealed copper wires A... Minimum breaking load line of conductors for low-voltage wires In Fig. 2, inventive product a and conventional Comparing product C, it takes about 0.71 for conventional product C to secure the minimum breaking load of 10 kof.
Although the conductor outer diameter was required to be 11 m, it can be seen that in the product a of the present invention, the outer diameter of the conductor is only about 0.5 mm.

In other words, it can be seen that the diameter can be reduced by 29% in diameter reduction rate and about 50% in cross-sectional area ratio.

Example 2 An experiment was conducted to determine the change in allowable current by using a stainless steel wire as the central strand, and the results are shown in FIG.

The rimple symbols in FIG. 3 are the same as in the first embodiment.

Note that B is an allowable current value (Δ) for guaranteeing the automobile W/H signal circuit.

Further, the allowable current calculation conditions are as follows.

Maximum operating temperature of conductor: 80℃ Ambient temperature: 60℃ Wire structure: Insulation sheath is made of polyvinyl chloride, insulation sheath thickness is 0.25mm As shown in Figure 3, the allowable current of the invention product a is lower than the conventional product C. However, the difference is not that great, for example, the outer diameter of the conductor is 0.5
It can be seen that even +nm ones can be used for automobile W/H signal circuits.

Furthermore, when classifying signal circuits by current, it has been found that the overwhelming majority of signal circuits are 1A or less.

[Effect of the invention] The compressed conductor of the present invention has the following effects.

(1) Since a conductor with high roundness can be obtained, the thickness of the insulating sheath can be reduced and the diameter can be reduced.

(2) A conductor with high surface smoothness f[ can be obtained.

(3) Because the central wire is strongly damaged, the wire is strong.
You can make harnesses, and you can also make thin wire harnesses.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the compressed conductor for wire A7 harness of the present invention, Fig. 2 is a graph showing the relationship between the outer diameter of the conductor and breaking load, Fig. 3 is a J graph showing the outer diameter of the conductor and allowable current, and Fig. 4 is a graph showing the relationship between the outer diameter of the conductor and the breaking load. The figure is a sectional view of a conventional compressed conductor for Wire A7 harness. 1...Central strand 2...Peripheral strand 3.3'''...Space a, b...Invented product c, d...Comparative amount Agent Patent attorney Yasuo Miyoshi No. 4 figure

Claims (1)

[Claims] Using high hardness, high strength single wire or stranded wire as the center wire,
A compressed conductor for wire harnesses, which is surrounded by outer strands made of single or stranded wires with a lower hardness than the center strand, twisted concentrically and compressed into a circular shape.