JP4182850B2 - Automotive wire - Google Patents

Description

  The present invention relates to an automobile electric wire, and more particularly to an automobile electric wire having a sufficient tensile strength and reduced in thickness and weight.

In an automobile, a wire harness in which a number of electric wires are bundled is used for electrical connection to an electrical component or the like. The conductor of the electric wire used for the wire harness requires a tensile strength of the conductor of about 80 N or more from the workability to the wire harness, and when using one electric wire, the cross-sectional area of 0.35 mm ² or more (hereinafter referred to as the conductor) Also referred to as size).

  Moreover, some electric wires used for the wire harness have a conductor having a twisted wire structure in which a plurality of strands are twisted together. An example of such a conductor is shown in FIG. In FIG. 1, reference numeral 1 denotes a conductor, which has a twisted wire structure in which six peripheral strands 3 are arranged around a central strand 2 and twisted together. Conventionally, copper has generally been used for the central strand 2 and the peripheral strand 3 constituting such a conductor having a stranded wire structure.

On the other hand, in recent automobiles, thinning of the electric wires used (for example, conductor size of 0.22 mm ² or less) and weight reduction have been required. However, in the case where copper is used for the conductor (center strand, peripheral strand), if such thinning and weight reduction are performed, the required tensile strength cannot be obtained.

  In view of this, a proposal has been made to reduce the thickness and weight by using a composite conductor using copper and stainless steel as the element wires (Japanese Utility Model Laid-Open No. 6-13014 (Patent Document 1)). ). The conductor in this automobile electric wire has a composite twisted wire structure in which stainless steel is used as a central strand, and a plurality of peripheral strands made of annealed copper are arranged around it. Stainless steel has a lower specific gravity than copper, and stainless steel has a higher tensile strength, so that it is possible to reduce the thickness and weight.

In such a structure, the elongation rate of the strand made of stainless steel is, for example, about 40% in the annealed material of SUS304, whereas the elongation rate of the strand made of copper is, for example, in a general annealed copper material The actual condition is that the elongation of the stainless steel wire is about 15% larger than that of the copper wire. In the present specification, the “elongation rate” refers to an increase in the length of the test piece immediately before breakage in the tensile test, expressed as a percentage of the original length.
However, in the case of an electric wire with such a structure, the elongation rate of the strands of stainless steel is larger than that of copper. Therefore, when a large tensile force is applied, the copper strands are cut before the stainless steel strands. In particular, only the stainless steel wire remains. If only the stainless steel wire remains, the conductor resistance is large and there is a possibility of heat generation when energized.

Japanese Utility Model Publication No. 6-13014

  The present invention eliminates such problems of the prior art, provides the required tensile strength, achieves thinning and weight reduction, and is highly reliable with no occurrence of heat or the like even if it is disconnected. The object is to provide an electric wire for automobiles.

According to the present invention, the above problem is solved by the following technical means.
(1) A plurality of peripheral strands made of copper or copper alloy and peripheral strands made of stainless steel are alternately arranged around the central strand made of stainless steel so as to surround the central strand. An automobile electric wire characterized in that an elongation rate of a strand made of stainless steel is smaller than an elongation rate of a strand made of copper or a copper alloy.
(2) The automobile electric wire according to (1), wherein the elongation rate of the strand made of stainless steel is 10 to 50% smaller than the elongation rate of the strand made of copper or a copper alloy.
(3) The automobile electric wire according to (1) or (2), wherein a cross-sectional area of the central strand and a cross-sectional area of the peripheral strand are the same.
(4) The automobile electric wire according to (1) or (2), wherein the cross-sectional area of the central strand is 70 to 95% of the cross-sectional area of the peripheral strand.
(5) A conductor in which a plurality of peripheral strands made of copper or copper alloy and peripheral strands made of stainless steel are alternately arranged around a central strand made of stainless steel so as to surround the central strand. The wire for automobiles according to any one of the above (1) to (4), characterized in that has a stranded wire structure.

  According to the present invention, since the above-described configuration is adopted, it is possible to provide a highly reliable automotive electric wire that can be thinned and reduced in weight without reducing tensile strength and that does not generate heat due to disconnection. It becomes.

  The preferred embodiments of the present invention will be described below.

That by the present invention automobiles for electric wire, made of stainless steel (SUS) ing of copper or a copper alloy so as to surround the said center strands around a center strand consisting of peripheral Henmotosen and stainless steel A plurality of peripheral strands are alternately arranged, and the elongation rate of the strands made of stainless steel is smaller than the elongation rate of the strands made of copper or a copper alloy.

In FIG. 2 , the state of the conductor in the structural example of the electric wire for motor vehicles by this invention is shown with sectional drawing. In the figure, 21 is an assembly of conductors, and a peripheral strand 23 made of copper or a copper alloy and a peripheral strand 24 made of stainless steel are alternately arranged and twisted around a central strand 22 made of stainless steel. It has a stranded wire structure. Further, the strand diameter of the central strand 22 and the strand diameters of the peripheral strands 23 and 24 are equal. An insulating coating is provided directly around the conductor assembly or through a shield layer to obtain an automobile electric wire. In the present invention, as described above, the elongation rate of the strand made of stainless steel is set smaller than the elongation rate of the strand made of copper or a copper alloy. The elongation of the stainless steel wire is preferably 10 to 50% smaller than the elongation of the copper or copper alloy wire. In this specification, “elongation rate” is based on JIS C 3002.

The stainless steel used for the center strand 22 of this configuration example needs to satisfy the above conditions. As a method for adjusting the elongation of the stainless steel, (1) Increase the C component. (For example, in SUS304, it is changed from about 0.03 wt% to about 0.07 wt%), (2) Ni component is reduced (for example, in SUS304, from about 10.0 wt% to about 8.0 wt%) ), (3) The final solution treatment temperature is slightly lowered in the strand manufacturing process (for example, the current 1000 to 1200 ° C. is changed to about 800 to 1000 ° C. in SUS304), and (4) The final solution treatment is performed in the strand manufacturing process. Reduce the processing time (for example, the current 5 seconds in SUS304 is set to about 80% of 4 seconds) (5) Final solution treatment in the wire manufacturing process A method can be used in which the previous cold working degree is increased to the working limit (about 95% with respect to the working limit). These methods may be used alone or in combination.
Although the strand diameter of the center strand 22 is suitably set according to a use, it is usually preferable to set it as about 0.1-0.2 mm.
The strand diameters of the central strand 22 and the peripheral strand 24 are appropriately set according to the use, but are usually about 0.1 to 0.2 mm.

Further, copper or copper alloy is used for peripheral strands 23, it can be used any of various types used for normal wire, conductive, tensile strength, pure copper in terms such as elongation, Cu-Ag alloy Cu-Ni-Si alloy or the like is preferably used. Although the strand diameter of the peripheral strand 23 is suitably set according to a use, it is about 0.1-0.2 mm normally.

As the insulating coating, various resin materials such as polyvinyl chloride (PVC), polyethylene (including foamed materials), halogen-free materials, and tetrafluoroethylene, which are conventionally used , can be used. The thickness of the insulating coating is appropriately set according to the outer diameter of the conductor assembly.
When providing a shield layer, various materials having a conventionally known shielding effect can be used.

According to the above configuration, since the elongation of the strand made of stainless steel is set to be smaller than the elongation of the wire made of copper or a copper alloy, added a large deal of tension, ten thousand Even if one strand breaks, since the stainless strand breaks before the copper or copper alloy strand, a situation such as heat generation does not occur. In addition, sufficient tensile strength can be ensured as a whole, and further thinning and weight reduction are possible.

Automotive electrical wire according to the present invention is not limited to the illustrated configuration example, various modifications and changes can be made.
For example, in the above description, a 7-strand type is used in which the periphery of one central strand is surrounded by 6 peripheral strands, but a 19-strand type in which the periphery is surrounded by 12 peripheral strands. It is good also as a thing.
Moreover, although it was set as the twisted-wire structure in the above, it does not need to be set as a twisted wire.
In the above, the strand diameter of the central strand is the same as the strand diameter of the peripheral strand. However, if the required tensile strength is obtained, the strand diameter of the central strand is changed to the strand of the peripheral strand. For example, when the cross-sectional area is smaller than the diameter, it may be about 70 to 95%. In this case, there is an advantage that the wire can be made thinner.

Here, an example of manufacturing an automobile electric wire according to the present invention will be described. Stainless steel element wire diameter: 0.18 mm, stainless steel element wire elongation: 10%, pure copper element wire diameter: 0.18 mm, pure copper element wire elongation: 15%, outside conductor assembly Diameter: 0.54 mmφ, tensile strength: 120 N. According to automotive wires This was subjected to rupture test, a stainless steel wire has been confirmed that expires before the pure copper wires. Moreover, it was confirmed that thinning and weight reduction can be achieved and high tensile strength can be obtained.

It is sectional drawing of the electric wire conductor for motor vehicles of the conventional twisted wire structure. That by the present invention is a cross-sectional view of an example of the configuration of the automotive electric wire conductor.

Explanation of symbols

21 Assembly of conductors 22 Central wire 23 Peripheral wire 24 Peripheral wire

Claims (5)

  A plurality of peripheral strands made of copper or copper alloy and peripheral strands made of stainless steel are alternately arranged around the central strand made of stainless steel so as to surround the central strand. An automobile electric wire characterized in that an elongation rate of the resulting wire is smaller than an elongation rate of the wire made of copper or a copper alloy. 2. The electric wire for automobile according to claim 1, wherein the elongation rate of the strand made of stainless steel is 10 to 50% smaller than the elongation rate of the strand made of copper or a copper alloy. The electric wire for automobiles according to claim 1 or 2 , wherein a cross-sectional area of the central strand and a cross-sectional area of the peripheral strand are the same. The electric wire for automobiles according to claim 1 or 2 , wherein a cross-sectional area of the central strand is 70 to 95% of a cross-sectional area of the peripheral strand. A conductor in which a plurality of peripheral strands made of copper or copper alloy and peripheral strands made of stainless steel are alternately arranged around a central strand made of stainless steel so as to surround the central strand It is a structure, The electric wire for motor vehicles in any one of Claims 1-4 characterized by the above-mentioned.

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