JP2015196881A - Aluminum alloy strand, aluminum alloy strand wire and electric wire for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy strand, aluminum alloy strand wire, capable of achieving an electric wire for vehicle, in which a conductor is hardly broken even when tension force is applied to the electric wire for vehicle, during assembly of a wire harness and assembly of the wire harness to a vehicle, compared with a conventional one, and provide an electric wire for vehicle having the aluminum alloy strand and aluminum alloy strand wire.SOLUTION: An aluminum alloy strand 100 comprises a chemical composition including: 5 mass% or more and less than 7 mass% of Zn; 1.5 mass% or more and 3 mass% or less of Mg; and as balance, Al and inevitable impurities, and has tension force of 450 MPa or higher. An aluminum alloy strand wire 10 is formed by intertwining the plural aluminum alloy strands 100. An electric wire 1 for vehicle comprises a conductor formed of the aluminum alloy strand wire 10, and an insulator 3 coated on an outer periphery of the conductor.

Description

  The present invention relates to an aluminum alloy strand, an aluminum alloy twisted wire, and an automobile electric wire.

  Conventionally, in the field of automobiles, wire harnesses are used to connect various electric and electronic devices. The wire harness has a plurality of electric wires for automobiles and connector terminals attached to electric wire terminal portions of the electric wires for automobiles. Generally, an automobile electric wire applied to a wire harness has a conductor made of a copper alloy strand or a copper alloy twisted wire softened by heat treatment and an insulator coated on the outer periphery of the conductor. doing.

  In recent years, from the viewpoint of reducing the weight of automobiles, aluminum alloys that are lighter than copper alloys have been applied as conductors for automobile wires.

  For example, Patent Document 1 discloses an automobile electric wire having a conductor formed by subjecting an aluminum alloy to a heat treatment after drawing. The aluminum alloy contains 0.3 to 10.0% by weight of at least one element selected from Cu and Mg, 0.01 to 1.0% by weight of Zr, and / or 0.02 to 2% of Si. It is contained in a proportion of 0% by weight, and the balance consists of Al and inevitable impurities. Further, this document describes that the tensile strength of the conductor is adjusted to 260 to 340 MPa by heat treatment.

JP 2006-176832 A

However, the prior art has problems in the following points. That is, as a method for further reducing the weight of the wire harness, a method of reducing the diameter of a conductor made of an aluminum alloy is effective. However, conventional aluminum alloys have low strength. Therefore, when a tensile force is applied to the automobile electric wire when assembling the wire harness or assembling the wire harness to the automobile, the conductor may be disconnected. Therefore, it is difficult to apply aluminum alloy strands or aluminum alloy stranded wires as conductors for relatively small-diameter automotive wires, and copper alloy strands and copper alloy stranded wires are still widely used. It is. In particular, in the case of an automobile electric wire having a conductor cross-sectional area of 0.15 mm ² or less, the above problem is remarkable.

  The present invention has been made in view of the above background, and even when a tensile force is applied to an automobile electric wire when assembling a wire harness or assembling a wire harness to an automobile, the conductor is less likely to break than in the past. An object of the present invention is to provide an aluminum alloy strand, an aluminum alloy twisted wire, and an automotive electric wire having these, which can realize an automotive electric wire.

One aspect of the present invention is an aluminum alloy strand used for a conductor of an automobile electric wire,
Zn: 5% by mass or more and less than 7% by mass, Mg: 1.5% by mass or more and 3% by mass or less, and the balance has a chemical composition composed of Al and inevitable impurities,
An aluminum alloy strand characterized by a tensile strength of 450 MPa or more.

  Another aspect of the present invention is an aluminum alloy twisted wire characterized in that a plurality of the aluminum alloy strands are twisted together.

  Still another aspect of the present invention is an electric wire for an automobile having a conductor made of the aluminum alloy strand or the aluminum alloy twisted wire and an insulator coated on an outer periphery of the conductor.

  The aluminum alloy strand contains Zn: 5 mass% or more and less than 7 mass%, Mg: 1.5 mass% or more and 3 mass% or less, and the balance has a chemical composition composed of Al and inevitable impurities. The tensile strength is 450 MPa or more. Therefore, the said aluminum alloy strand can exhibit the intensity | strength which can endure the tensile force concerning the electric wire for motor vehicles at the time of the assembly of a wire harness, or the assembly | attachment of the wire harness to a motor vehicle. Therefore, the above aluminum alloy wire realizes an electric wire for automobiles whose conductors are less likely to break than before even when a tensile force is applied to the electric wires for automobiles when assembling the wire harness or assembling the wire harness to the automobile. It becomes possible to do.

  The aluminum alloy stranded wire is formed by twisting a plurality of the aluminum alloy strands. Therefore, the aluminum alloy stranded wire realizes an electric wire for an automobile in which the conductor is less likely to be disconnected than in the past even when a tensile force is applied to the electric wire for the automobile when the wire harness is assembled or the wire harness is assembled to the automobile. It becomes possible.

  The automobile electric wire has a conductor made of the aluminum alloy strand or the aluminum alloy stranded wire. For this reason, the electric wire for automobiles is less likely to break the conductor as compared with the conventional case even when a tensile force is applied when the wire harness is assembled or the wire harness is assembled to the automobile.

It is explanatory drawing which shows the structure of the aluminum alloy twisted wire in Example 2, and the electric wire for motor vehicles. It is explanatory drawing which shows the structure of the aluminum alloy twisted wire in Example 3, and the electric wire for motor vehicles.

  The reason for limiting the chemical composition of the aluminum alloy strand will be described.

Zn: 5 mass% or more and less than 7 mass% Zn is an element effective for improving the strength of the aluminum alloy wire. Zn is required to be contained in an amount of 5% by mass or more in order to develop a tensile strength of 450 MPa or more by precipitation hardening. The Zn content is preferably 5.2% by mass or more, more preferably 5.5% by mass or more, still more preferably 5.8% by mass or more, and still more preferably from the viewpoint of improvement in tensile strength or the like. It is good in it being 6 mass% or more. On the other hand, when Zn is contained excessively, wire drawing becomes difficult. Moreover, since Zn which exists in a solid solution state increases, electrical conductivity also falls. Therefore, the Zn content is restricted to less than 7% by mass from the viewpoint of ensuring workability, the balance between tensile strength and electrical conductivity, and the like. The Zn content is preferably not more than 6.8% by mass, more preferably not more than 6.5% by mass, and still more preferably not more than 6.% by mass, from the viewpoints of improving workability and ensuring high conductivity. It is good in it being 2 mass% or less.

Mg: 1.5 mass% or more and 3 mass% or less Mg is an element effective for improving the strength of the aluminum alloy wire. Mg needs to be contained in an amount of 1.5% by mass or more in order to develop a tensile strength of 450 MPa or more by precipitation hardening. The Mg content is preferably 1.5% by mass or more, more preferably 1.8% by mass or more, and further preferably 2% by mass or more, from the viewpoint of improving tensile strength. On the other hand, when Mg is excessively contained, Mg existing in a solid solution state increases, and thus the conductivity decreases. Therefore, the Mg content is restricted to 3% by mass or less from the viewpoint of the balance between tensile strength and electrical conductivity. The Mg content is preferably 2.8% by mass or less, more preferably 2.5% by mass or less, and even more preferably 2.3% by mass or less from the viewpoint of easily ensuring high electrical conductivity. There should be.

  The chemical component composition may further contain Cu: 1% by mass or more and 2% by mass or less.

  When Cu is used together with Zn and Mg, it can contribute to exhibiting a tensile strength of 450 MPa or more by precipitation hardening. In order to obtain the effect, Cu is preferably contained in an amount of 1% by mass or more. The Cu content is preferably 1.1% by mass or more, and more preferably 1.2% by mass or more, from the viewpoint of improving tensile strength. On the other hand, if Cu is excessively contained, the amount of Cu existing in a solid solution state increases, so that the electrical conductivity decreases. Therefore, the Cu content is preferably 2% by mass or less from the viewpoint of the balance between tensile strength and electrical conductivity. The Cu content is preferably 1.8% by mass or less, more preferably 1.7% by mass or less, and still more preferably 1.6% by mass or less from the viewpoint of easily ensuring high electrical conductivity. There should be.

  The aluminum alloy strand has a tensile strength of 450 MPa or more. Thereby, the said aluminum alloy strand can exhibit the intensity | strength which can endure the tensile force concerning the electric wire for motor vehicles at the time of the assembly of a wire harness, or the assembly | attachment of the wire harness to a motor vehicle. The tensile strength is more preferably 470 MPa or more, and further preferably 490 MPa or more. The tensile strength is preferably 600 MPa or less, more preferably 595 MPa or less, and still more preferably 590 MPa or less from the viewpoint of balance with workability.

  The said aluminum alloy strand is good in electrical conductivity being 20% IACS or more. Thereby, it becomes possible to use suitably the electric wire for motor vehicles using the said aluminum alloy strand as a signal wire. Note that the conductivity is preferably 22% IACS or more, more preferably 24% IACS or more, and still more preferably 26% IACS or more. The conductivity is preferably 35.5% IACS or less, more preferably 35% IACS or less, and further preferably 34.5% IACS or less from the viewpoint of balance with tensile strength. it can.

The aluminum alloy strand may have a strand diameter in the range of 0.15 to 0.45 mm. Thereby, it becomes easy to make the cross-sectional area of an aluminum alloy twisted wire 0.15 mm ² or less. Further, in this case, the above-described effects are sufficiently exhibited. In addition, the said cross-sectional area is a value in a cut surface perpendicular | vertical to an axial direction. Further, when the conductor of the automobile electric wire is composed of a single aluminum alloy wire, the wire diameter is specifically, for example, 0.25 to 0.45 mm, preferably 0.32 to 0.40 mm. Can be within range. Further, when the conductor of the automobile electric wire is composed of an aluminum alloy stranded wire, the wire diameter is specifically in the range of, for example, 0.15 to 0.25 mm, preferably 0.16 to 0.18 mm. Can be inside.

  The aluminum alloy wire is preferably subjected to aging heat treatment after the wire drawing. Since the aluminum alloy wire has the above chemical component, it is selected from the group consisting of Zn, Mg, and (when Cu is included, Zn, Mg, Cu) by performing an optimal aging heat treatment The compound containing at least one kind of element is easily precipitated. Therefore, in this case, the strength improvement by precipitation hardening is ensured. Further, the conductivity is easily improved by precipitation of the above elements.

  The aluminum alloy stranded wire may be obtained by twisting a plurality of aluminum alloy strands, or may be compressed in the radial direction of the strand after the plurality of aluminum alloy strands are twisted together. In the latter case, the twisted wire diameter can be further reduced.

  Specifically, the aluminum alloy stranded wire includes, for example, an aluminum alloy strand disposed at the center and a plurality of aluminum alloy strands twisted around the outer periphery of the aluminum alloy strand disposed at the center. It can be set as the structure which has.

The aluminum alloy stranded wire may have a cross-sectional area of 0.15 mm ² or less. In this case, the above-described effects are sufficiently exhibited. The above cross-sectional area, diameter reduction, from the viewpoint of weight reduction, preferably, 0.145 mm ² or less, more preferably, may be 0.14 mm ² or less. The cross-sectional area is preferably 0.05 mm ² or more, more preferably 0.08 mm ² or more, and still more preferably 0, from the viewpoint of securing the strength of the aluminum alloy twisted wire, the productivity of the aluminum alloy twisted wire, and the like. 1 mm ² or more.

  The said electric wire for motor vehicles has an insulator on the outer periphery of the conductor which consists of the said aluminum alloy strand or the said aluminum alloy twisted wire. An insulator can be comprised from the resin composition which has polymers, such as various resin and rubber | gum (including an elastomer), which have electrical insulation, as a main component. The above resins and rubbers can be used alone or in combination of two or more. Specific examples of the polymer include a vinyl chloride resin, a polyolefin resin, and a polysulfone resin. The insulator may be composed of one layer, or may be composed of two or more layers. The thickness of the insulator can be, for example, 0.1 mm or more and 0.4 mm or less. The insulator may contain one or two or more kinds of additives generally used for electric wires. Specific examples of the additive include fillers, flame retardants, antioxidants, anti-aging agents, lubricants, plasticizers, copper damage inhibitors, and pigments.

  The said aluminum alloy strand and the said aluminum alloy twisted wire can be suitably manufactured as follows, for example.

  First, a rod-shaped cast material having a predetermined chemical component composition is drawn so as to have a predetermined wire diameter. The wire drawing can be repeated once or twice or more. Further, before the wire drawing process, if necessary, the cast material may be subjected to plastic working such as rolling or extrusion to obtain an optimum shape for the wire drawing process. Next, the obtained wire is subjected to a heat treatment for precipitation hardening. Thereby, an aluminum alloy strand is obtained. As the heat treatment conditions, for example, the wire drawing material is heated at about 450 ° C. to 500 ° C. for about 0.5 hours to 3 hours, and then immediately cooled by water cooling or the like, and at about 100 ° C. to 150 ° C. for about 10 hours to 48 hours. Conditions such as heating to some extent can be exemplified.

  The aluminum alloy stranded wire can be formed by twisting a plurality of the aluminum alloy strands.

  In addition, each structure mentioned above can be arbitrarily combined as needed, in order to acquire each effect etc. which were mentioned above.

(Example 1)
By adding a predetermined amount of Zn, Mg, and if necessary, Cu to aluminum having a purity of 99.7%, the contents of Zn, Mg, and if necessary, Cu are contained as shown in Table 1, with the balance being Al. And each alloy molten metal which has a chemical component composition which consists of unavoidable impurities was produced. Each obtained molten alloy was cast into a rod shape of φ9.5 mm to obtain each cast material. Each drawing material was repeatedly subjected to wire drawing to obtain each wire drawing material having a wire diameter of 0.3 mm. However, Sample 6 could not be drawn because the force required for processing was excessive. Next, each obtained wire was heated at 480 ° C. for 1 hour, then immediately cooled with water (solution treatment), and heated at 120 ° C. for 24 hours, followed by aging heat treatment. Thereby, the aluminum alloy strands of Sample 1 to Sample 5 were obtained.

  About each obtained aluminum alloy strand, the tension test and the measurement of electrical conductivity were implemented. The tensile test conditions were as follows: distance between gauge points GL = 250 mm, tensile speed 50 mm / min. Moreover, the measurement of electrical conductivity (% IACS) was computed by measuring the electrical resistance between distances between gauge points GL = 1000 mm. The obtained results are summarized in Table 1.

  As shown in Table 1, the aluminum alloy strands of Sample 1 and Sample 2 have an Mg content of 5% by mass or less. Therefore, the tensile strength was less than 450 MPa. This is because precipitation hardening by aging heat treatment was insufficient. Therefore, in the case of an automobile electric wire using the aluminum alloy wires of Sample 1 and Sample 2 as conductors, there is a possibility that the conductor may be disconnected due to tensile force applied when the wire harness is assembled or when the wire harness is assembled to the automobile. I can say that.

  On the other hand, the aluminum alloy strands of Samples 3 to 5 contain Zn: 5% by mass to less than 7% by mass, Mg: 1.5% by mass to 3% by mass, and the balance is made of Al and inevitable impurities. The tensile strength is 450 MPa or more. Therefore, the said aluminum alloy strand can exhibit the intensity | strength which can endure the tensile force concerning the electric wire for motor vehicles at the time of the assembly of a wire harness, or the assembly | attachment of the wire harness to a motor vehicle. Therefore, the above aluminum alloy wire realizes an electric wire for automobiles whose conductors are less likely to break than before even when a tensile force is applied to the electric wires for automobiles when assembling the wire harness or assembling the wire harness to the automobile. I can say that. Moreover, it becomes easy to reduce the weight of the electric wire for automobiles.

  Moreover, when the sample 3 and the sample 4 were compared, when the said chemical component composition further contained Cu: 1 mass% or more and 2 mass% or less, it was also confirmed that tensile strength improves more.

(Example 2)
In the production of the aluminum alloy strands of Sample 3 to Sample 5 in Example 1, each of the seven aluminum alloy strands of Sample 7 to Sample 9 was performed in the same manner except that wire drawing was performed to a wire diameter of 0.16 mm. It was made one by one. In addition, the tensile strength of each aluminum alloy strand was 450 MPa or more. Next, as shown in FIG. 1, seven aluminum alloy strands 100 were twisted together. This obtained the aluminum alloy twisted wire 10 of the sample 7W-the sample 9W which has the cross-sectional shape shown by FIG. Each aluminum alloy stranded wire has a cross-sectional area of 0.14 mm ² . Moreover, each insulator (thickness 0.25 mm) was formed by coating the PVC resin composition on the outer periphery of the aluminum alloy stranded wires of Sample 7W to Sample 9W. Thereby, the automotive electric wire 1 of the sample 7A-the sample 9A which has the aluminum alloy twisted wire 10 which has the cross-sectional shape shown by FIG. 1, and the insulator 3 which coat | covers the outer periphery of the aluminum alloy twisted wire 10 was obtained.

  The aluminum alloy twisted wire is formed by twisting a plurality of aluminum alloy strands having a specific chemical composition and a tensile strength of 450 MPa or more. Therefore, the aluminum alloy stranded wire realizes an electric wire for an automobile in which the conductor is less likely to be disconnected than in the past even when a tensile force is applied to the electric wire for the automobile when the wire harness is assembled or the wire harness is assembled to the automobile. It can be said that it is possible.

  Moreover, the said electric wire for motor vehicles has the conductor which consists of the said aluminum alloy twisted wire. Therefore, it can be said that the electric wire for automobiles is less likely to break the conductor as compared with the conventional case even when a tensile force is applied when the wire harness is assembled or when the wire harness is assembled to the automobile.

(Example 3)
In Example 2, as shown in FIG. 2, a sample having the cross-sectional shape shown in FIG. 2 is obtained in the same manner except that seven aluminum alloy strands 200 are twisted and then circular compression processing is performed. The aluminum alloy twisted wires 20 of 7S to 9S were obtained. In addition, all the cross-sectional areas of each aluminum alloy twisted wire are 0.13 mm < ² >. In addition, each insulator (thickness 0.2 mm) was formed by coating the outer periphery of the aluminum alloy stranded wires of Sample 7S to Sample 9S with the PVC resin composition. Thereby, the automotive electric wire 2 of the sample 7B-the sample 9B which has the aluminum alloy twisted wire 20 which has the cross-sectional shape shown by FIG. 2, and the insulator 3 which coat | covers the outer periphery of the aluminum alloy twisted wire 20 was obtained. The said aluminum alloy twisted wire and the said electric wire for motor vehicles can show | play the effect similar to Example 2. FIG.

  As mentioned above, although the Example of this invention was described in detail, this invention is not limited to the said Example, A various change is possible within the range which does not impair the meaning of this invention.

1, 2 Automotive wire 10, 20 Aluminum alloy strand 100, 200 Aluminum alloy strand

Claims (8)

An aluminum alloy strand used for a conductor of an automobile wire,
Zn: 5% by mass or more and less than 7% by mass, Mg: 1.5% by mass or more and 3% by mass or less, and the balance has a chemical composition composed of Al and inevitable impurities,
An aluminum alloy strand characterized by a tensile strength of 450 MPa or more.   The said chemical component composition contains Cu: 1 mass% or more and 2 mass% or less further, The aluminum alloy strand characterized by the above-mentioned.   The aluminum alloy strand according to claim 1 or 2, wherein the conductivity is 20% IACS or more.   The aluminum alloy strand according to any one of claims 1 to 3, wherein the strand diameter is in a range of 0.15 to 0.45 mm.   The aluminum alloy strand according to any one of claims 1 to 4, wherein an aging heat treatment is performed after the wire drawing.   A plurality of aluminum alloy strands according to any one of claims 1 to 5, wherein a plurality of aluminum alloy strands are twisted together. The aluminum alloy stranded wire according to claim 6, wherein the cross-sectional area is 0.15 mm ² or less.   It has the conductor which consists of an aluminum alloy strand of any one of Claims 1-5, or the aluminum alloy twisted wire of Claim 6 or 7, and the insulator coat | covered on the outer periphery of this conductor. A featured electric wire for automobiles.

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