JP2014173097A - Aluminum alloy wire, aluminum alloy stranded wire, insulation wire and wire harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy wire having high strength, such aluminum alloy stranded wire, an insulation wire and a wire harness.SOLUTION: There is provided an aluminum alloy wire containing Cu of 2.0 mass% to 6.0 mass% and the balance Al with inevitable impurities and having a tension strength of 220 MPa or more and conductivity of 30%IACS or more. There is also provided an aluminum alloy stranded wire using the aluminum alloy wire, an insulation wire and a wire harness.

Description

  The present invention relates to an aluminum alloy wire, an aluminum alloy twisted wire, an insulated wire, and a wire harness, and more particularly to an aluminum alloy wire having high strength, an aluminum alloy twisted wire using the same, an insulated wire, and a wire harness.

  Conventionally, in the electric power field such as an overhead power transmission line, an aluminum electric wire having a conductor made of an aluminum-based material has been used for the purpose of reducing the weight of the electric wire. In the automotive field, conventionally, copper wires having conductors made of copper-based materials with excellent electrical conductivity have been widely used as signal lines and power lines. However, in recent years, high performance and high functionality of vehicles have rapidly increased. With the progress made, attempts have been made to use an aluminum electric wire having a conductor made of an aluminum-based material in the automobile field in order to reduce the weight of the electric wire.

  Since an aluminum electric wire has a lower strength than a conventionally used copper electric wire, an aluminum alloy electric wire is being applied as an automobile electric wire for the purpose of improving the strength. For this purpose, for example, an alloy based on an Al—Fe alloy as described in Patent Documents 1 to 3 is used.

International Publication No. 2011/004814 International Publication No. 2009/054457 JP 2010-163677 A

  An electric wire made of an Al—Fe alloy has a higher strength than an Al electric wire, but has a lower strength in comparison with a conventionally used copper electric wire, and places where it can be mounted in an automobile are limited. In particular, in places where bending and vibration are always applied, fatigue fracture due to insufficient strength tends to occur, and it cannot be applied.

  The problem to be solved by the present invention is to provide an aluminum alloy wire having high strength and to provide such an aluminum alloy stranded wire, an insulated wire, and a wire harness.

  In order to solve the above problems, the aluminum alloy wire according to the present invention contains Cu in an amount of 2.0% by mass or more and 6.0% by mass or less, the balance is made of Al and inevitable impurities, and the tensile strength is 220 MPa or more. The gist is that the conductivity is 30% IACS or more.

  Here, the aluminum alloy wire may further contain a refining agent for refining the crystal structure of Cu in the aluminum alloy.

  In this case, the micronizing agent is at least one selected from 0.01% by mass to 0.05% by mass Ti and 0.001% by mass to 0.005% by mass B. Is preferred.

  The alloy further contains one or more additive elements selected from Mn, Mg, Si, and Zn in a total amount of 0.005% by mass to 3.2% by mass. Good.

  And it is preferable that a strand diameter is 0.15 mm or more and 0.45 mm or less.

  The gist of the aluminum alloy stranded wire according to the present invention is that a plurality of the above aluminum alloy wires are twisted together.

  Here, the twist pitch is preferably 60 times or less the layer core diameter.

  The gist of the insulated coated electric wire according to the present invention is that the outer circumference of the aluminum alloy stranded wire or a compression wire obtained by compression molding the aluminum alloy stranded wire is covered with an insulating coating layer.

  The wire harness concerning this invention makes it a summary to have said insulation coating electric wire.

  The aluminum alloy wire according to the present invention contains 2.0% by mass or more of Cu, has high strength, and can achieve a tensile strength of 220 MPa or more through appropriate heat treatment. Thereby, even if bending or vibration is applied, the aluminum alloy wire is hardly broken. In addition, the Cu content is 6.0% by mass or less, and the conductivity is 30% IACS or more, so that even if Cu is contained, it is a signal line for automobiles in terms of conductivity. A practical aluminum alloy wire can be obtained.

  Here, when the aluminum alloy wire further contains a refining agent for refining the crystal structure of Cu in the aluminum alloy, Cu is dispersed as a fine crystal structure in the aluminum alloy, The occurrence of defects such as cracks during casting and rolling is suppressed.

  In this case, the refiner is at least one selected from 0.01% by mass to 0.05% by mass Ti and 0.001% by mass to 0.005% by mass B. Therefore, it is possible to effectively realize the refinement of the Cu crystal structure.

  The alloy further contains one or more additive elements selected from Mn, Mg, Si, and Zn in a total amount of 0.005% by mass to 3.2% by mass. And the intensity | strength of an aluminum alloy is further improved easily and electrical conductivity is also improved.

  When the element wire diameter is 0.15 mm or more and 0.45 mm or less, an aluminum alloy wire can be manufactured with high workability, and the influence of strain applied during bending can be suppressed.

  Since the aluminum alloy stranded wire according to the present invention is formed by twisting a plurality of the above aluminum alloy wires, it has high tensile strength and electrical conductivity. Here, when the twist pitch is 60 times or less the layer core diameter, the twist of the aluminum alloy wire is difficult to be eliminated even when subjected to vibration or bending.

  Since the insulation-coated electric wire and the wire harness according to the present invention have the above-described aluminum alloy stranded wire, they have high tensile strength and electrical conductivity, and can be suitably used for locations that receive vibration and bending in an automobile.

(A) shows the aluminum alloy strand wire concerning one Embodiment of this invention, (b) shows the compression wire which compression-molded it, (c) shows the insulated wire which has the aluminum alloy strand wire of (a). Show.

Next, an embodiment of the present invention will be described in detail. In the present specification, the contents of the component elements are all expressed in units of mass%.

  The aluminum alloy wire according to the embodiment of the present invention contains 2.0 to 6.0% of Cu, and the balance is composed of Al and inevitable impurities. And it has a tensile strength of 220 MPa or more and a conductivity of 30% IACS (Universal Soft Copper Standard) or more.

  Cu contributes to improving the strength of the aluminum alloy wire. In order to obtain the effect, the Cu content is set to 2.0% or more. If the Cu content is less than 2.0%, the aluminum alloy wire does not have sufficient strength. The Cu content is preferably 2.5% or more.

  On the other hand, when the Cu content is 6.0% or less, the aluminum alloy wire has a sufficiently high conductivity. If the Cu content exceeds 6.0%, the conductivity of the aluminum alloy wire becomes too low, making it difficult to use it as an automobile wire. The Cu content is preferably 5.5% or less, more preferably 4.5% or less.

  As described above, when the Cu content in the aluminum alloy wire is 2.0% or more, high strength can be obtained, but even with an aluminum alloy having the same composition, solution treatment, aging treatment, etc. If the manufacturing conditions including the heat treatment are not appropriately selected, there may be a case where sufficient strength as an automobile electric wire cannot be achieved. Therefore, the aluminum alloy wire of the present invention is prescribed to have the above composition and a tensile strength of 220 MPa or more. The tensile strength of 220 MPa or more is equal to or higher than the tensile strength of a copper wire for automobiles, and is sufficient for use as a wire for automobiles. The tensile strength of the electric wire is a good index for strength against bending motion and vibration motion, and when it has a tensile strength of 220 MPa or more, occurrence of fatigue fracture of the electric wire due to bending or vibration is suppressed. More preferably, the aluminum alloy wire has a tensile strength of 250 MPa or more.

  In addition, as described above, when the Cu content in the aluminum alloy wire is 6.0% or less, it is possible to obtain a high conductivity. However, the conductivity is the same as that of the tensile strength. It depends on the manufacturing conditions. Therefore, the aluminum alloy wire of the present invention is specified to have the above composition and a conductivity of 30% IACS or higher. By having a conductivity of 30% IACS or higher, an aluminum alloy wire can be suitably used as a signal wire for an automobile. The aluminum alloy wire preferably has a conductivity of 35% IACS or more, more preferably 40% IACS or more.

  This aluminum alloy wire may contain a finer in addition to Cu. The micronizing agent is to refine the crystal structure of Cu in the aluminum alloy. By miniaturizing the crystal structure of Cu, the occurrence of defects such as cracks is suppressed in processes such as casting and rolling, and the productivity of the aluminum alloy wire is improved. Thereby, productivity of an aluminum alloy wire is improved.

  Examples of the finer include Ti and B. These may contain only 1 type and may be contained together. The Ti content is preferably 0.01 to 0.05%. The B content is preferably 0.001 to 0.005%. When the Ti content is less than 0.01% and when the B content is less than 0.001%, it is difficult to obtain the effect of refining the crystal structure. On the other hand, when the Ti content exceeds 0.05% and the B content exceeds 0.005%, the effect of the addition is saturated and the conductivity of the aluminum alloy wire is easily lowered. More preferably, the Ti content is 0.01 to 0.03%, and the B content is 0.001 to 0.003%.

  This aluminum alloy wire may further contain one or more additive elements selected from Mn, Mg, Si, and Zn. These elements contribute to improving the strength of the aluminum alloy wire. In order to obtain the effect, the total content of these elements is preferably 0.005 to 3.2%. When the total content is less than 0.005%, the strength improvement effect is small. On the other hand, if the total content exceeds 3.2%, the electrical conductivity of the aluminum alloy wire tends to be lowered. Of the above four elements, Mn, Mg, and Si are more preferable in terms of excellent strength improvement effect. Further, the total content of the four elements is more preferably 0.1 to 3.2%.

  The aluminum alloy wire preferably has a wire diameter of 0.15 to 0.45 mm. When the wire diameter is less than 0.15 mm, the workability when processing the aluminum alloy into a wire shape is lowered. On the other hand, when the wire diameter exceeds 0.45 mm, it is easily affected by distortion when it is bent and used.

  Although the said aluminum alloy wire may be manufactured how, the following manufacturing methods can be illustrated.

  First, an aluminum alloy having the above alloy composition is cast. In this casting process, first, a molten aluminum alloy having a desired alloy composition is formed. In order to form a molten aluminum alloy, pure aluminum as a base is melted in a melting furnace, and Cu and necessary additive elements are introduced into the melted pure aluminum so as to have a desired concentration. The aluminum alloy molten metal whose components are adjusted may be appropriately subjected to a hydrogen gas removal treatment or a foreign matter removal treatment. Then, the molten aluminum alloy is rapidly solidified.

  Next, the obtained aluminum alloy is plastically processed to form an aluminum alloy wire. Specifically, first, an aluminum alloy obtained by casting is rolled to produce a wire rod, and then drawn by wire drawing until a desired strand diameter is obtained. The wire drawing may be performed by cold working.

  The aluminum alloy wire thus obtained may be appropriately heat treated. The tensile strength and electrical conductivity of the aluminum alloy wire depend not only on the component composition but also on the heat treatment conditions. Specific heat treatment includes solution treatment and subsequent aging treatment.

  The solution treatment is preferably performed at 480 to 550 ° C. This is because if the solution temperature is less than 480 ° C., the amount of solid solution is insufficient and the final strength is lowered, and if it exceeds 550 ° C., the melting point is exceeded, making it difficult to manufacture.

  The aging treatment is preferably performed at a temperature from room temperature to 200 ° C. More preferably, the temperature may be from room temperature to 170 ° C. When the temperature of the aging treatment is higher than 200 ° C., it is difficult to improve the tensile strength of the aluminum alloy. The time for aging treatment may be set as appropriate according to the treatment temperature and desired tensile strength, but it may be configured to be 100 hours or more at room temperature and 10 hours or more at 170 ° C.

  An aluminum alloy stranded wire 10 according to an embodiment of the present invention is formed by twisting a plurality of aluminum alloy wires 1 according to the embodiment of the present invention as a strand, as shown in a sectional view in FIG. The number of aluminum alloy wires 1 to be twisted may be appropriately selected in consideration of the strength and conductivity desired for the aluminum alloy twisted wire 10.

  The aluminum alloy stranded wire 10 may have a twist pitch of 60 times or less the layer core diameter. In this case, twisting between the aluminum alloy wires 1 is difficult to be eliminated even when subjected to bending or vibration.

  The aluminum alloy stranded wire 10 may be compression-molded into a circular shape to form a compressed wire 10a as shown in FIG. The entire wire diameter can be reduced by compression molding.

  The covered electric wire 20 according to the embodiment of the present invention is formed by covering the outer periphery of the aluminum alloy stranded wire 10 or the compressed wire 10a with the insulating coating 2, as shown in FIG. Although the insulating material which comprises the insulation coating 2 is not specifically limited, For example, what is necessary is just insulating resin materials, such as polyvinyl chloride (PVC) and a non-halogen resin. In particular, a material having excellent flame retardancy is preferably used. The thickness to be coated is not particularly limited.

  The wire harness according to the embodiment of the present invention has the covered electric wire 20. The plurality of covered electric wires constituting the wire harness may be all the covered electric wires 20, or only a part thereof may be the covered electric wires 20.

  Hereinafter, the present invention will be described more specifically with reference to examples.

(Preparation of aluminum alloy wire)
A molten aluminum alloy was prepared so as to have the alloy composition shown in Table 1, and a φ9.5 mm wire rod was produced by casting. The obtained wire rod was cold-drawn to produce an aluminum alloy strand having a diameter of 0.3 mm. Furthermore, after performing a solution treatment at 500 ° C. for 3 hours, an aging treatment was performed under the conditions shown in Table 1. Thereby, the aluminum alloy wire concerning Examples 1-15 and Comparative Examples 1-6 was obtained.

(Evaluation of tensile strength)
In accordance with JIS Z 2241 (metal material tensile test method), the tensile strength of each aluminum alloy wire was measured with a general-purpose tensile tester. A case where the tensile strength was 220 MPa or more was evaluated as acceptable “◯”, and a case where the tensile strength was less than 220 MPa was determined as unacceptable “x”.

(Evaluation of conductivity)
The electrical conductivity of each aluminum alloy wire was measured by a bridge method. A case where the electrical conductivity was 30% IACS or higher was evaluated as “good”, and a case where the electrical conductivity was lower than 30% IACS was determined as “failed”.

(Productivity evaluation)
In order to investigate the influence of the addition of a finer agent on the manufacturability, the manufacturability of each aluminum alloy wire was evaluated. In other words, in the manufacturing process of aluminum alloy wire, those that did not have defects or cracks were particularly good in productivity, and those that were capable of being manufactured but had defects or cracks were manufactured. Good “O”. Moreover, what produced many defects and a crack and was very difficult to manufacture was made into "x" with bad manufacturability.

(Results and discussion)
Table 1 shows the component composition and aging treatment conditions of each aluminum alloy wire, and Table 2 shows the evaluation results of tensile strength and electrical conductivity. The column of aging treatment in Table 1 is displayed in the format of “temperature × time”, and RT indicates room temperature. “RT × 100 hr” indicates that an aging treatment is performed for 100 hours at room temperature.

  The aluminum alloy wire according to each example contains Cu in the range of 2.0 to 6.0%, and has a tensile strength of 220 MPa or more and a conductivity of 30% IACS or more.

  The aluminum alloy wires according to Examples 1 to 4 contain only Ti and B other than Cu as additive elements, and their contents are the same as each other, but when these are compared, the Cu content is 2.0. There is a tendency that the tensile strength increases as the content increases in the range of ˜6.0%. Moreover, the tendency for electrical conductivity to become high is seen, so that there is little content of Cu within the range of 2.0 to 6.0%. On the other hand, the aluminum alloy wires according to Comparative Examples 2 and 5 also contain the same amounts of Ti and B as in Examples 1 to 4, but in Comparative Example 2, the Cu content is too high at 6.5%. , The conductivity is too low, less than 30% IACS. In Comparative Example 5, the Cu content is too low at 1.80%, so that the tensile strength is too small and is less than 220 MPa.

  Aluminum according to Examples 6 to 8 and Examples 10 and 11 containing one or more additive elements selected from Mg, Mn, Si and Zn in a total range of 0.005 to 3.2% When the alloy wires are compared with the aluminum alloy wires according to Example 3 and Example 4 in which the contents of Cu are close to or coincide with each other and do not contain these additive elements, It can be seen that the tensile strength is further improved. On the other hand, in the aluminum alloy wire according to Comparative Example 6, although the content of Cu is in the range of 2.0 to 6.0%, Mg, Mn, and Si total more than 3.2% and a large amount Contained. Due to this, the conductivity is less than 30% IACS. In Comparative Example 1, since the Cu content is too small, sufficient tensile strength is not achieved even if these additive elements are added.

  The aluminum alloy wire according to Example 15 does not contain Ti and B which are finer agents. When this is compared with the aluminum alloy wires according to Example 1 and Example 13 having the same Cu content and containing a micronizing agent, the same tensile strength and conductivity are obtained regardless of the presence or absence of the micronizing agent. Although the rate is achieved, the productivity is slightly inferior when no finer is contained. That is, Ti and B as the finer have an effect of improving the productivity of the aluminum alloy wire.

  In Comparative Example 4, the component composition is the same as that in Examples 6 and 7, but the tensile strength is less than 220 MPa due to the high aging temperature of 345 ° C. The mutual comparison of the tensile strength and conductivity of Examples 6 and 7 and Comparative Example 4 having the same component composition and different aging conditions shows that the tensile strength and conductivity of the aluminum alloy wire are not only in the component composition but also in the heat treatment conditions. It shows that it depends.

  As described above, an aluminum alloy wire having a tensile strength of 220 MPa or more and a conductivity of 30% IACS or more is obtained by setting the Cu content in the range of 2.0 to 6.0% and performing an appropriate heat treatment. be able to. Furthermore, the tensile strength can be further improved by adding one or more additive elements selected from Mg, Mn, Si, and Zn in the range of 0.005 to 3.2%. Moreover, the productivity of an aluminum alloy wire is improved by adding it as Ti and B refining agents.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

1, 1a Aluminum alloy wire 2 Insulation coating 10 Aluminum alloy stranded wire 10a Compressed wire 20 Coated electric wire

Claims (9)

  Cu is contained 2.0% by mass or more and 6.0% by mass or less, the balance is made of Al and inevitable impurities, the tensile strength is 220 MPa or more, and the conductivity is 30% IACS or more. Aluminum alloy wire.   The aluminum alloy wire according to claim 1, further comprising a refining agent for refining the crystal structure of Cu in the aluminum alloy.   The micronizing agent is at least one selected from 0.01% by mass to 0.05% by mass Ti and 0.001% by mass to 0.005% by mass B. The aluminum alloy wire according to claim 2.   Furthermore, it contains 0.005 mass% or more and 3.2 mass% or less in total of 1 type, or 2 or more types of additional elements selected from Mn, Mg, Si, and Zn. 4. The aluminum alloy wire according to any one of 3 above.   The aluminum alloy wire according to any one of claims 1 to 4, wherein a strand diameter is 0.15 mm or more and 0.45 mm or less.   A plurality of aluminum alloy wires according to any one of claims 1 to 5, wherein the aluminum alloy wires are twisted together.   The aluminum alloy twisted wire according to claim 6, wherein the twist pitch is 60 times or less the layer core diameter.   An insulation-coated electric wire, wherein an outer periphery of the aluminum alloy stranded wire according to claim 6 or 7 or a compressed wire obtained by compression-molding the aluminum alloy stranded wire is covered with an insulation coating layer.   A wire harness comprising the insulated coated electric wire according to claim 8.

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