JP2018056102A - Wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire excellent in conductivity between a conductor with a large area and a connection member such as terminals even with light weight.SOLUTION: There is provided a wire having a conductor and an insulation coating for coating outer periphery of the conductor, a cross section area of the conductor is over 20 mm, the conductor is a twisted wire aggregate obtained by twisting a plurality of twisted wires, each of which is obtained by twisting a plurality of single wires constituted by aluminum or an aluminum alloy, and has at least one center twisted wire and an outer periphery twisted wire arranged in a layer shape, which is twisted in outer periphery of the center twisted wire, and contains at least one of a set of inner and outer layers having different twist pitches of neighboring layers, and a set of inner and outer layers having different cross angles to an axis of the conductor in the single wire constituting each neighboring layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric wire.

As the wire, such as power distribution applications typically consist annealed copper, which is a cross-sectional area comprises a conductor which is 2mm ² ~325mm ² is utilized. As this conductor, there is a twisted wire assembly in which a plurality of twisted wires formed by twisting a plurality of tin-plated annealed copper wires are twisted (for example, JIS C 3315 (2000)). Patent Document 1 discloses a stranded conductor formed by concentrically twisting seven stranded wires obtained by twisting 42 tin-plated annealed copper wires having an outer diameter of 0.18 mm.

JP 2005-251608 A

Weight reduction is desired for electric wires for power distribution applications.
An electric wire including the above-described copper conductor is heavy. In particular, an electric wire including a conductor having a large area with a cross-sectional area exceeding 20 mm ² is heavier. For this reason, the burden on the operator is large when the operator transports the electric wire to the installation site, installs it, or lifts the end of the electric wire to attach the connection member such as a terminal at the installation site. It is desired to reduce the weight of the electric wire.

  The inventors of the present invention have studied to configure a conductor with aluminum or an aluminum alloy (hereinafter sometimes referred to collectively as Al) that is lighter than copper. However, the present inventors have obtained knowledge that, when a connecting member such as a terminal is attached to a conductor made of Al or the like by crimping or the like, the electrical resistance of the connecting portion of the connecting member in the conductor may vary. . Therefore, even if the connecting member is crimped to the conductor at an arbitrary position of the electric wire, the electric resistance of the connecting portion does not vary, and a stable value can be obtained, that is, an electric wire excellent in conductivity between the conductor and the connecting member. Is desired.

  Accordingly, an object of the present invention is to provide an electric wire that is lightweight and has excellent conductivity between a large-area conductor and a connection member such as a terminal.

An electric wire according to an aspect of the present disclosure is
An electric wire comprising a conductor and an insulating coating covering the outer periphery of the conductor,
The cross-sectional area of the conductor is greater than 20 mm ² ;
The conductor is
A twisted wire assembly in which a plurality of strands made of aluminum or an aluminum alloy are twisted together, and a plurality of twisted wires are twisted together. At least one center twisted wire and the outer periphery of the center twisted wire are twisted and layered It is provided with a peripheral stranded wire to be arranged,
It includes at least one of a set of inner and outer layers in which the twist pitch of each adjacent layer is different, and a set of inner and outer layers in which the crossing angle with respect to the axis of the conductor in the element wire constituting each adjacent layer is different.

  While the above-mentioned electric wire is light, it has excellent conductivity between a large-area conductor and a connection member such as a terminal.

3 is a schematic cross-sectional view showing the electric wire according to Embodiment 1. FIG. 1 is a schematic perspective view showing an electric wire according to Embodiment 1. FIG. It is explanatory drawing explaining the crossing angle with respect to the axis | shaft of the conductor in a strand.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described.
(1) An electric wire according to an aspect of the present invention is
An electric wire comprising a conductor and an insulating coating covering the outer periphery of the conductor,
The cross-sectional area of the conductor is greater than 20 mm ² ;
The conductor is
A twisted wire assembly in which a plurality of strands made of aluminum or an aluminum alloy are twisted together, and a plurality of twisted wires are twisted together. At least one center twisted wire and the outer periphery of the center twisted wire are twisted and layered It is provided with a peripheral stranded wire to be arranged,
It includes at least one of a set of inner and outer layers in which the twist pitch of each adjacent layer is different, and a set of inner and outer layers in which the crossing angle with respect to the axis of the conductor in the element wire constituting each adjacent layer is different.

When a set of inner and outer layers having different twist pitches is provided, the twist pitch of each layer is as follows.
When one outer peripheral layer is provided on the outer periphery of the central stranded wire, and the inner layer in the inner / outer layer set is composed of one central stranded wire (hereinafter sometimes referred to as a single-core configuration), The "pitch" is the twist pitch of the central twisted wire if it is a collective twist, the twisted pitch of the outermost layer constituting the central twisted wire if it is a concentric twist, and the twisted pitch of the outer layer is the twisted pitch of the outer peripheral layer .
When the inner layer in the set of inner and outer layers is formed by twisting a plurality of central twisted wires (hereinafter sometimes referred to as a multi-core configuration), the “twist pitch” of the inner layer means the plurality of center twists. The pitch is a twisted line.
When the outer periphery of the central stranded wire is provided with a plurality of outer peripheral layers, and the set of the inner and outer layers is two layers selected from these outer peripheral layers (hereinafter, sometimes referred to as a multilayer outer peripheral form), the selected two layers Let the twist pitch be the twist pitch of the inner layer and the twist pitch of the outer layer, respectively.

When a set of inner and outer layers having different crossing angles is provided, the crossing angle of each layer is as follows.
In the case of the above-described single-core configuration, the “intersection angle of the strands” in the inner layer means that if the central twisted wire is a collective twist, this central twisted wire is provided with a single outer peripheral layer around the central twisted wire. The angle that intersects the axis of the conductor in the strand of wire, and the angle that intersects the axis of the conductor in the strand constituting the outermost layer of the central stranded wire if concentric twisting. In the case of the above-described multi-core configuration, the “intersection angle of the strands” in the inner layer is an angle that intersects the axis of the conductor in the strand located on the outermost side of the multi-core stranded wires.
In the case of the above-described multi-layer outer peripheral form, and the set of the inner and outer layers is two layers selected from these outer peripheral layers, the angle is set to intersect the axis of the conductor in the wire constituting each of the selected two layers.

Although the electric wire includes a conductor having a large area with a cross-sectional area exceeding 20 mm ² , the conductor is made of aluminum or an aluminum alloy (Al or the like), and thus is lighter than the case where the above-described copper conductor is provided. In addition, since this conductor is a stranded wire assembly in which a plurality of stranded wires are twisted together, it is easy to handle even if the number of strands is large, and because of the large number of strands, it is excellent in flexibility, bending, etc. Easy to do. Therefore, the above-mentioned electric wire can reduce the burden on the operator when laying, and is excellent in laying workability.

  And while the above-mentioned electric wire has a simple configuration in which the twisting pitch of each layer adjacent to the inside and outside of the twisted wire assembly and the crossing angle of the strands are different, the end of the conductor When a connection member such as a terminal is pressure-bonded to the contact member, it has excellent conductivity with the connection member (details will be described later). For this reason, the electric wire is less likely to vary in the electric resistance of the connection portion of the conductor with the connection member, and easily takes a stable value. Further, if the above-described electric wires are used, even if the number of wires is large, it is not necessary to remove a natural oxide film (described later) of each wire with a brush or the like, and the connecting member can be attached. Also from this point, the above-mentioned electric wire is excellent in laying workability.

The above electric wires are based on the following knowledge.
The inventors of the present invention have studied to configure the conductor with Al or the like in order to reduce the weight of the electric wire. Here, Al or the like has a lower conductivity than copper, and the conductor size needs to be made larger in order to pass a current equivalent to that of the copper conductor through a conductor such as Al. Further, it is desired that even a conductor with a large area can be bent well. Therefore, the use of a stranded wire having a cross-sectional area exceeding 20 mm ² for the conductor was examined. However, when the insulating coating is removed, the end of the conductor is exposed, and a connection member such as a terminal is crimped, the electrical resistance of the connection portion of the connection member in the conductor may vary as described above. The reason is considered as follows. The larger the cross-sectional area of the conductor, the greater the number of strands and the number of layers. Then, the ratio of the strand which does not contact the said connection member directly among the strands which comprise a twisted wire increases. On the other hand, when the insulating coating is removed and the conductor is exposed to the atmosphere, a natural oxide film, which is an electrical insulating material, is formed on the surface of each strand made of Al or the like. Therefore, adjacent strands are in contact with each other via both natural oxide films (a natural oxide film having a thickness twice that of the natural oxide film provided on one strand). It is conceivable that due to the presence of both natural oxide films, electrical conduction between the wires that do not directly contact the connecting member cannot be sufficiently obtained, and the above-described electrical resistance varies.

  On the other hand, when a stranded wire assembly is formed by twisting a plurality of stranded wires, and the twisting pitch of each layer adjacent inside and outside and the crossing angle of the strands are different in the constituent layers of the stranded wire assembly, the continuity between the strands It was found that the above-mentioned electrical resistance was difficult to vary. The reason is considered as follows. The stranded wires (or strands) constituting the layers adjacent to each other inside and outside are arranged in an intersecting state in accordance with the pitch and the deviation of the intersecting angle of the strands. Therefore, it can be said that the arbitrary stranded wires constituting the stranded wire assembly include a lot of point-contacting locations when the relationship between the stranded wires adjacent to at least one of the inner and outer sides is observed. When such a twisted wire assembly is used as a conductor, and the connection member is attached as described above, the point contact portions described above are pressed against each other at the connection portion of the conductor with the connection member, and natural oxidation is interposed between the strands. This is thought to be because the film is broken and it becomes easier to conduct the wires.

(2) As an example of the above wire,
When the connection member is attached by crimping or compressing the conductor, a form in which the electrical resistance of the connection portion of the connection member in the conductor is equal to or lower than the electrical resistance of the conductor can be mentioned.

  Even if the cross-sectional area of the conductor is larger or the number of strands or the number of laminated layers is larger, the above-mentioned form is applied to the conductor when the connection member is crimped to the conductor at an arbitrary position as described above. The electrical resistance at the connection location of the connection member is equal to or lower than the electrical resistance of the single conductor and is low. Therefore, the said form is lightweight while being excellent in the electroconductivity of a conductor and a connection member.

(3) As an example of the above wire,
The said strand wire aggregate | assembly is a form provided with the outer periphery twisted wire of two or more layers.

  In the above configuration, the outer peripheral layer formed by the outer peripheral stranded wire is a multilayer, and although it can be said that the cross-sectional area of the conductor is larger or the number of strands is larger, the twist pitch and the intersection angle of the strands are different as described above. Since the inner and outer layers are provided, the electrical conductivity between the conductor and the connection member is excellent, and the weight is light.

(4) As an example of the electric wire of (3) above, the outer peripheral layer formed by the outer peripheral stranded wire is a multilayer.
The form which contains the group of the inner and outer layer from which the twist direction of each adjacent layer differs in the outer peripheral layer which the said outer periphery twisted wire makes is mentioned.

  Although the said form has a multilayer outer peripheral layer, since it includes the group of the inner and outer layers by which a twisted wire is arrange | positioned by a different twist direction, it is easy to have a point contact point. Therefore, when the above-mentioned connection member is crimped | bonded to a conductor in arbitrary positions as mentioned above, the said form is lightweight while being excellent in the electroconductivity of a conductor and a connection member.

(5) As an example of the above wire,
It includes a set of inner and outer layers having different crossing angles, and the value of the larger absolute value of the crossing angle in the inner and outer layers is 1.5 times or more and 4 times or less of the value of the smaller absolute value of the crossing angle. One form is mentioned.

  Since the said form includes the group of the inner and outer layers where the crossing angle of the strands satisfies the above specific condition, for example, even when the twist pitches of the inner and outer layers are the same, it is easy to have a large number of the above point contact locations. Therefore, when the above-mentioned connection member is crimped | bonded to a conductor in arbitrary positions as mentioned above, the said form is lightweight while being excellent in the electroconductivity of a conductor and a connection member.

(6) As an example of the above electric wire,
Sectional area of the wires can be cited embodiment is 0.02 mm ² or more 0.5 mm ² or less.

  The above configuration is easy to obtain an appropriate number of strands, and when the connecting member is crimped to a conductor at an arbitrary position as described above, between the strands due to the destruction of the natural oxide film at the point contact location described above, etc. Can be conducted. Therefore, the said form is lightweight while being excellent in the electroconductivity of a conductor and a connection member. Moreover, since the said form is equipped with the strand assembly of suitable number of strands, it is easy to perform a bending etc.

(7) As an example of the above wire,
Among the plurality of strands, at least one strand includes Fe in an amount of 0.005% by mass to 2.2% by mass, and the balance is made of an aluminum alloy that is Al and inevitable impurities. .

  The above-mentioned form is excellent in mechanical properties such as strength such as tensile strength and toughness such as elongation at break by containing Fe in a specific range, and also reduces the decrease in conductivity due to Fe content and has high conductivity. Can have. In particular, when adjusting the elongation at break by applying a softening process in the manufacturing process, when a connecting member such as a terminal is crimped to the end portion of the conductor, the strand is easily deformed, and the contact area with the connecting member In addition, the degree of improvement in strength due to work hardening of the conductor is large. Therefore, the above-mentioned form is lightweight and excellent in electrical conductivity between the conductor and the connecting member, and also excellent in mechanical properties, electrical conductivity, and adhesion between the conductor and the connecting member.

(8) As an example of the electric wire of (7) containing Fe in a specific range,
The aluminum alloy further includes one or more elements selected from Mg, Si, Cu, Zn, Ni, Mn, Ag, Cr, Zr, and Y in total of 0.005% by mass to 1.0% by mass. The form to contain below is mentioned.

  In the above-mentioned form, in addition to Fe, by including the listed elements in a specific range, at least one of strength and toughness can be further increased, and reduction in conductivity due to the inclusion of these elements can be reduced. Therefore, the said form is lightweight, and is excellent in electrical conductivity with a conductor and a connection member, and is excellent in mechanical characteristics, electroconductivity, and the adhesiveness of a conductor and a connection member.

[Details of the embodiment of the present invention]
Hereinafter, a specific example of an electric wire according to an embodiment of the present invention will be described with reference to the drawings.
[Embodiment 1]
With reference to FIG. 1, the electric wire 1 of Embodiment 1 is demonstrated. FIG. 1 is a cross-sectional view of the electric wire 1 cut along a plane orthogonal to the longitudinal direction thereof, and FIG. 2 shows the conductor 2 by partially removing the insulating coating 3 of the electric wire 1 to expose the conductor 2. It is a perspective view which shows the state which peeled off the conductor 2 stepwise so that the lamination | stacking state of the twisted wire 20 to make it easy to understand. 1 and 2, each stranded wire 20 constituting the conductor 2 is simplified and shown as one circle, and one stranded wire 20 is illustrated in a one-dot chain line circle.

The electric wire 1 according to the first embodiment includes a conductor 2 and an insulating coating 3 that covers the outer periphery of the conductor 2. The conductor 2 has a relatively large cross-sectional area, and the conductor 2 is made of a specific material and has a specific structure. Have Specifically, the conductor 2 has a cross-sectional area exceeding 20 mm ² , and a stranded wire in which a plurality of stranded wires 20 in which a plurality of strands 200 made of aluminum or an aluminum alloy (Al or the like) are stranded are stranded. It is an aggregate. The stranded wire assembly includes at least one central stranded wire 2c and an outer peripheral stranded wire 2o that is twisted around the outer periphery of the central stranded wire 2c and arranged in a layered manner. And in the electric wire 1 of Embodiment 1, the axis | shaft L of the conductor 2 in the strand 200 which comprises the group of the inner / outer layer from which the twist pitch of each adjacent layer differs, and each adjacent layer as a structural layer of a twisted wire assembly (FIG. It includes at least one of a set of inner and outer layers having different intersection angles θi and θo with respect to 3).
Details will be described below.

(Electrical wire)
The electric wire 1 includes a conductor 2 and an insulating coating 3 and is typically a round wire having a circular cross section. In addition, the electric wire 1 can be a flat cable or the like provided with a plurality of conductors 2 and an insulating coating that integrally covers the conductors 2 in a state where the conductors 2 are arranged side by side.

-Conductor The conductor 2 is a twisted wire assembly obtained by further twisting a twisted wire 20 in which a plurality of strands 200 are twisted, and each strand 200 is made of Al or the like, and its total cross-sectional area exceeds 20 mm ² . is there.

-Composition In Al etc. which comprise each strand 200, "aluminum" is what is called pure aluminum, and means what consists of Al and an unavoidable impurity. “Aluminum alloy (hereinafter sometimes referred to as Al alloy)” means an element containing an additive element and the balance being Al and inevitable impurities.

  When at least one of the plurality of strands 200 is made of pure aluminum, it is easy to have high conductivity, soft and easy to bend, elongation at break, etc., compared to the case of being made of Al alloy. It has advantages such as excellent toughness. When a connecting member such as a terminal is crimped to the conductor 2 from the point of being soft or the like, the element wire 200 is plastically deformed, so that the natural oxide film is destroyed or the new surfaces are exposed and the new surfaces are easily brought into contact with each other. Expected.

  When at least one of the plurality of strands 200 is made of an Al alloy, it has advantages such as excellent strength and rigidity and being difficult to break compared to a case of being made of pure aluminum. From the viewpoint of high strength and the like, when a connecting member such as a terminal is pressure-bonded to the conductor 2, it is expected that the natural oxide film is easily broken by pressing between the strands 200 and 200.

  The conductor 2 is configured to include a strand 200 having a different composition, specifically a configuration including a pure aluminum wire and an Al alloy wire as the strand 200, a configuration including an Al alloy wire having a plurality of types of compositions, and the like. Can do. For example, as the strand 200 of the stranded wire 20 positioned on the outer peripheral side of the conductor 2, the strand 200 includes a wire having a composition excellent in toughness such as elongation at break, and as the strand 200 of the stranded wire 20 positioned on the inner peripheral side of the conductor 2, When a wire having a composition excellent in strength and the like is included, the conductor 2 is excellent in strength and toughness, and is easy to bend and can be made to have a high toughness. When all the strands 200 constituting the conductor 2 are wires having the same composition, since the mechanical characteristics of the strand 200 are uniform, local weak points are not easily generated in the conductor 2 and the twisting condition is not generated. Etc. are easy to adjust, and it is excellent in manufacturability.

  The composition of the Al alloy constituting the element wire 200 can be selected as appropriate. As an example, an Al alloy containing Fe in a specific range described later, an Al alloy including one or more elements selected from a specific element group described below in addition to Fe, an element having a crystal fine effect described later, and the like. Can be mentioned. Hereinafter, the additive elements will be described. The element content is set to a mass ratio (mass%) with the Al alloy as 100 mass%.

<Fe: 0.005% to 2.2%>
Fe can improve the strength of the Al alloy without causing much decrease in the conductivity of the Al alloy. Inclusion of 0.005% or more of Fe contributes to increasing the strength of the Al alloy, and the greater the amount of Fe, the easier it is to obtain a strength improvement effect. By including Fe in the range of 2.2% or less, there is little decrease in toughness and electrical conductivity, and it is easy to have high breaking elongation and high electrical conductivity, and it is easy to reduce disconnection at the time of wire drawing. Also excellent. Since the strength can be increased, it is easy to have a high strength even when subjected to a softening treatment. When a connecting member such as a terminal is pressure-bonded to the conductor 2, the Al alloy wire is easily deformed by softening, and the contact area with the connecting member is easily increased, and the degree of improvement in strength due to work hardening of the conductor 2 is increased. It is large and excellent in adhesion between the conductor 2 and the connecting member. When Fe is contained in an amount of 0.2% or more, further 0.5% or more, 0.9% or more, 1.0% or more, or 1.05% or more, the strength is easily increased. When Fe is contained in the range of 2.0% or less, and further 1.8% or less, it tends to have high elongation at break and high electrical conductivity.

<Element group: One or more selected from Mg, Si, Cu, Zn, Ni, Mn, Ag, Cr, Zr, and Y in total 0.005% to 1.0%>
By including one element selected from the above element group, or two or more elements, it is possible to further improve the strength and toughness of the Al alloy, and improve the adhesion between the conductor 2 and the connecting member. I can expect. Although Mg has a large decrease in conductivity, the effect of improving strength is high. In particular, when Mg and Si are contained at the same time, the strength is easily increased. Although Mn, Ni, Zr, and Cr have a large decrease in electrical conductivity, the effect of improving the strength is high. Ag and Zn have a small decrease in conductivity and a certain degree of strength improvement effect. Cu has little decrease in conductivity and has an effect of improving strength. As described above, Si is contained at the same time as Mg, so that the effect of improving strength is high. Y has the effect of improving the strength while making the crystal grains fine. Examples of the content of each element include the following.
Mg: 0.05% to 0.5%, 0.05% to 0.4%, 0.1% to 0.4% Mn, Ni, Zr, Zn, Cr and Ag: 0 in total 0.005% to 0.2%, and in total 0.005% to 0.15% Cu: 0.05% to 0.5%, and 0.05% to 0.4% Si: 0 .05% to 0.3%, Si: 0.05% to 0.2% Y: 0.01% to 0.5%, further 0.01% to 0.3% Mg, Cu When Zn, Ni, Mn, Ag, Cr, and Zr are contained in the above range, the strength is excellent, and the toughness and conductivity are reduced by reducing the toughness and conductivity, and disconnection is hardly caused. When Si is contained in the above range, the strength is excellent, and also the toughness and conductivity are reduced by reducing the decrease in toughness and conductivity. When Y is contained in the above range, the strength and toughness are excellent.

<Crystal refinement element: at least one of Ti of 0.01% or more and 0.05% or less and B of 0.001% or more and 0.005% or less>
When at least one of Ti of 100 ppm to 500 ppm and B of 10 ppm to 50 ppm are contained by mass ratio, it is easy to make Al alloy crystals fine at the time of casting. An Al alloy having a fine crystal structure tends to have high strength. Moreover, when at least one of Ti and B is contained in said range, the fall of electrical conductivity will be reduced and it will be excellent also in electroconductivity.

Specific examples of the composition of the Al alloy containing the above-described additive element include the following.
(1) Fe is contained in an amount of 0.005% to 2.2%, and the balance is Al and inevitable impurities. (2) Fe is 0.005% to 2.2%, Mg, Si, Cu, Zn , Ni, Mn, Ag, Cr, Zr, and Y containing a total of one or more elements selected from 0.005% to 1.0%, with the balance being Al and inevitable impurities (3) The above (1) or (2) further contains at least one of 0.01% to 0.05% Ti and 0.001% to 0.005% B.

Specific examples of the composition (2) include the following.
(2-1) Fe from 0.9% to 1.2%, Mg from 0.1% to 0.25% (2-2) Fe from 1.0% to 2.2%, Mg 0.05% or more and 0.5% or less, and one or more elements selected from Si, Mn, Ni, Zr, Zn, Cr, and Ag in total 0.005% or more and 0.2% or less (2- 3) Fe is 0.05% or more and 2.2% or less (further 0.1% or more, 0.5% or more, 1.0% or more), Cu is 0.01% or more and 0.5% or less (further 0 0.02% or more, 0.05% or more) (2-4) Fe is 1.0% or more and 2.2% or less, Cu is 0.05% or more and 0.5% or less, and Mg is 0.1% or more and 0% or less. .5% or less and at least one kind of Si (0.05% to 0.3%) (2-5) Fe from 0.005% to 0.6%, Mg from 0.2% to 0.5% Hereinafter, Si is set to 0. % Or more 0.35% or less, Cu of 0.05% to 0.1% or less, Mn 0.005% to 0.1% or less, Y and 0.5% 0.01%

Sectional area of ... sectional area conductor 2 and 20 mm ² or more, application can be appropriately changed in accordance with the standards. For example, the cross-sectional area of the conductor 2 can be 22 mm ² or more.

.. Structure The conductor 2 is a twisted wire including one or a plurality of central stranded wires 2c arranged at the center of the conductor 2 and an outer peripheral stranded wire 2o arranged in one or more layers on the outer periphery of the central stranded wire 2c. It is a line assembly. Typically, as shown in FIG. 1 and FIG. 2, the twisted wire 20 is a collective twist, and the twisted wire assembly is a concentric twist. Collective twisting is a twisting method in which a plurality of strands are gathered and twisted in the same direction. Concentric twisting is a method in which a plurality of outer peripheral materials (here, twisted wires 20) are twisted together in one layer or multiple layers on the outer periphery of one or a plurality of central materials (here, stranded wires 20), and the outer periphery of the central material is made annular. This is a twisting method in which the surrounding outer peripheral layer is formed in order so that the center of the ring is concentric with the center of the central member. By making each stranded wire 20 a collective twist, it is excellent in manufacturability. At least one stranded wire 20 constituting the stranded wire assembly may be concentric stranded. 1 and 2 exemplify a case where the central stranded wire 2c constituting the first layer of the stranded wire assembly is a single stranded wire and is a concentric strand having a plurality of outer peripheral layers. When the central stranded wire 2c is single, the gap between the adjacent stranded wires 20 and 20 can be easily reduced, and a reduction in the diameter of the conductor 2 and thus the electric wire 1 can be expected. The first layer of the stranded wire assembly may be a twist of a plurality of stranded wires 20. 1 and 2, the number of strands of the stranded wire 20 and the number of stranded wires constituting the stranded wire assembly are examples.

≪Section area and number of strands of strands≫
The cross-sectional area of each strand 200 constituting each stranded wire 20 and the number of strands are the cross-sectional area of the conductor 2, the number of stranded wires, the composition of each strand 200, the twist pitch, the twist direction, and the twist angle of the strand 20. In consideration of adjustment items such as required characteristics (eg, bending) of the conductor 2, it can be selected as appropriate. The sum of the cross-sectional areas of the strands 200 constituting each stranded wire 20 (when the cross-sectional area of each strand 200 is substantially equal, the product of the cross-sectional area and the number of strands) is the cross-sectional area of each stranded wire 20 Become.

An example of the cross-sectional area of each strand 200 is 0.02 mm ² or more and 0.5 mm ² or less. If the cross-sectional area of the strand 200 is 0.02 mm ² or more, it is easy to obtain an appropriate number of strands by preventing the number of strands from becoming excessive to satisfy the cross-sectional area exceeding 20 mm ² . When the number of strands is an appropriate amount, the amount of the natural oxide film increases due to the excess of the number of strands. As a result, failure of the natural oxide film at the point contact point described above, and finally the connection member in the conductor 2 It is possible to prevent the occurrence of variations in electrical resistance at the connection points. Further, it is possible to prevent the workability of the twisting work from being lowered, and consequently the productivity from being lowered. If the cross-sectional area of the strand 200 is 0.5 mm ² or less, the strand 200 includes a certain number of strands within a range where the cross-sectional area exceeds 20 mm ^2. , 200 are likely to contain many points where the points contact each other. Since there are many point contact locations, it is expected that when the connecting member is crimped to the conductor 2 as described above, it is easy to conduct the wires 200 and 200. In addition, it is difficult to invite bending due to an insufficient number of strands.

  As shown in this example, the cross-sectional areas of the strands 200 constituting one stranded wire 20 may be substantially equal. In this form, each of the strands 200 is typically substantially the same shape, and can be said to be a wire having a substantially uniform outer diameter. The manufacturability of the strand 200 itself is also excellent. Or the conductor 2 can also be provided with the strand 20 containing the strand 200 from which cross-sectional area differs. For example, when the cross-sectional areas of the strands 200 and 200 of the layers adjacent to each other inside and outside are different, there is a possibility that many locations where the strands 200 and 200 are in point contact with each other are included. If there are many point contact locations, when the connecting member is crimped to the conductor 2 as described above, it is expected that the wires 200 and 200 can easily conduct each other.

  Although the number of strands constituting each stranded wire 20 depends on the above-described adjustment items, for example, about 10 or more and 100 or less can be mentioned. The larger the number of strands, the easier it is to perform bending and the like, and there is a possibility that more portions where the strands 200, 200 are in point contact are included. If there are many point contact locations, when the connecting member is crimped to the conductor 2 as described above, it is expected that the wires 200 and 200 can easily conduct each other. The smaller the number of strands, the easier it is to reduce the amount of natural oxide film that can be formed on the entire conductor 2, but if it is too small, there is a risk of forming a twisted wire assembly that is difficult to bend. As shown in this example, the number of strands constituting each stranded wire 20 may be substantially equal. Or the conductor 2 can also be provided with the twisted wire 20 from which the number of strands differs.

≪Strand pitch and twist angle of twisted wire≫
The twist pitch and twist angle in the stranded wire 20 of the collective twist can be selected as appropriate. The twist pitch and twist angle of each layer in the concentric twisted stranded wire 20 having a multilayer outer peripheral layer can be selected as appropriate. The twist angle of the stranded wire 20 refers to an angle intersecting the axis of the stranded wire 20 in the strand 200 constituting the stranded wire 20.

≪Twist direction of stranded wire≫
The twist direction in the stranded wire 20 of the collective twist can be selected as appropriate. In the concentric stranded wire 20 in which the outer peripheral layer is a multilayer, the twisting directions of the respective layers can be made equal or different.

<Stranded wire assembly>
The stranded wire assembly includes a central stranded wire 2c formed of the above-described stranded wire 20 and one or more outer peripheral stranded wires 2o, and is typically concentric stranded as in this example. Since the twisted wire assembly in which the twisted wires 20 are further twisted is provided as the conductor 2, the electric wire 1 is a large-area conductor 2, and is easy to handle and bend even if the number of strands is large.

≪Cross sectional area and number of stranded wires≫
The cross-sectional area of each strand 20 and the number of stranded wires can be changed by changing the cross-sectional area of each strand 200, the number of strands, etc. in consideration of the adjustment items described in the above section <Stranded Wire>. Can be appropriately selected.

Although the cross-sectional area of each stranded wire 20 depends on the above-described adjustment items, for example, it is about 1 mm ² or more and 10 mm ² or less. For example, when the cross-sectional area of the strand is relatively small within the above range, the cross-sectional area of the stranded wire 20 can be about 7 mm ² or less, 5.5 mm ² or less, or about 4 mm ² or less. When the cross-sectional area of the stranded wire 20 satisfies the above range, an excessive number of stranded wires, in other words, an excessive number of strands, is prevented as described in the above section <Stranded Wire>. It is easy to prevent problems caused by excessive and insufficient number of strands. As a result, when the connection member is crimped to the conductor 2 as described above, it is expected that the wires 200 and 200 are easily connected to each other.

  As shown in this example, the cross-sectional area of each stranded wire 20 has a substantially equal form. In this form, typically, each stranded wire 20 has substantially the same shape, and can be said to be a member having a substantially uniform outer diameter, and it is easy to have mechanical characteristics and the like uniformly. The manufacturability of the stranded wire 20 itself is also excellent. Alternatively, the conductor 2 can include stranded wires 20 having different cross-sectional areas. For example, when the cross-sectional areas of the stranded wires 20 and 20 of the layers adjacent to each other inside and outside are different, there is a possibility that many portions where the stranded wires 20 and 20 are in point contact with each other are included. If there are many point contact locations, when the connecting member is crimped to the conductor 2 as described above, it is expected that the wires 200 and 200 can easily conduct each other.

  The number of stranded wires constituting the stranded wire assembly is, for example, about 7 to 91, although it depends on the adjustment items described above. In the concentric twisted wire assembly, for example, the strands 1/6/12/18/24 /... Are arranged in order from the center side, and 7 strands, 19 strands, 37 strands, 61 strands are arranged. , ... and so on. The conductor 2 shown in FIGS. 1 and 2 is a concentric twist of 37 stranded wires 20. The number of stranded wires listed above is an example, and the number of stranded wires constituting each layer can be changed as appropriate. The greater the number of stranded wires, the easier it is to perform bending and the like, and there may be more locations where the stranded wires 20, 20 are in point contact. If there are many point contact locations, when the connecting member is crimped to the conductor 2 as described above, it is expected that the wires 200 and 200 can easily conduct each other. If the number of stranded wires is too small, there is a risk of forming a stranded wire assembly that is difficult to bend.

In addition, the number of outer peripheral layers provided in the stranded wire assembly can be appropriately selected in consideration of the above-described adjustment items. For example, when the cross-sectional area of the conductor 2 is small or the cross-sectional area of each stranded wire 20 is large, the stranded wire assembly can include only one outer peripheral layer. Or, for example, when the cross-sectional area of the conductor 2 is large, when the cross-sectional area of each stranded wire 20 is small, or when the number of strands is large, the stranded wire assembly is provided with two or more outer peripheral layers, that is, a central twisted wire. Two or more outer peripheral stranded wires 2o can be provided on the outer periphery of the wire 2c. 1 and 2, in order from the inside, a first outer peripheral layer composed of the outer peripheral twisted wire 21, a second outer peripheral layer composed of the outer peripheral twisted wire 22, and a third outer peripheral layer composed of the outer peripheral twisted wire 23. Although the case where a total of three outer peripheral layers are provided is illustrated, it may be four or more. The greater the number of layers, the greater the number of stranded wires, which facilitates bending and the like, and may include many points where the stranded wires 20 and 20 are in point contact. In the electric wire 1 of Embodiment 1, since the twist pitch of each adjacent layer and the crossing angle (theta) i, (theta) o of the strand 200 differ, the point contact location of the above-mentioned twisted wires 20 and 20 is included more. Including certainly. If there are many point contact locations, when the connecting member is crimped to the conductor 2 as described above, it is expected that the wires 200 and 200 can easily conduct each other. From these points, the inner and outer layers of the electric wire 1 according to the first embodiment are different from each other in that at least one of the twisting pitches of adjacent layers and the intersecting angles θi and θo of the strands 200 in the twisted wire assembly constituting the conductor 2 is different. The configuration “including a set” is considered to be a configuration that is suitable when the number of constituent layers of the twisted wire assembly is larger, typically when the cross-sectional area of the conductor 2 is larger (particularly 22 mm ² or more).

≪Twisted pitch≫
As an example of the twisted wire assembly, one having at least one set of an inner layer and an outer layer in which the twist pitches of adjacent layers are different can be mentioned. When the outer peripheral layer is only one layer, the stranded wire 20 constituting the inner layer is the central stranded wire 2c, and the stranded wire 20 constituting the outer layer is the outer peripheral stranded wire 2o (here, the outer peripheral stranded wire 21). . In the single-core form, if the central stranded wire 2c is a collective twist, its twist pitch, or if it is concentric stranded, the outermost twist pitch, or in the multi-core form, a multi-core twist obtained by twisting a plurality of central twisted wires 2c. The twist pitch of the wire is different from the twist pitch of the outer layer formed by the outer peripheral twisted wire 21 (this form is called α). When two or more outer peripheral layers are provided, at least one of the form α and the following form β is satisfied. Form β is a form in which at least one pair of inner and outer layers has a different twist pitch (for example, a twist pitch of an inner layer formed by outer peripheral twisted wire 21) among “a set of two layers adjacent to each other” selected from the outer peripheral layer. This is a mode in which the twist pitch of the outer layer formed by the outer peripheral twisted wire 22 is different. When the twist pitches of the adjacent layers are different, the stranded wire 20 constituting the inner layer and the stranded wire 20 constituting the outer layer are arranged in an intersecting state and include many points that are in point contact with each other. Therefore, when a connecting member such as a terminal is pressure-bonded to the conductor 2 at an arbitrary position of the electric wire 1, the natural oxide film on the surface of the element wire 200 is destroyed by pressing each other at the point contact point, and the element It is easy to ensure conduction between the lines 200 and 200.

  All the twist pitches of the constituent layers of the stranded wire assembly may be different. Or when the above-mentioned connection member is attached, it is also possible to provide a constituent layer having substantially the same twist pitch within a range in which the electrical resistance of the connection portion of the connection member in the conductor 2 does not become excessive. In the case where at least one set of inner and outer layers in which the twisting directions of adjacent layers to be described later are different is provided, the twisting directions are different so that the twisted wires 20 and 20 constituting each layer are arranged in a crossed state and are in point contact with each other. You can have a place to do. Therefore, for example, even if the constituent layers having the same twist pitch are included, it is expected that the electric resistance is not likely to be excessive.

  The twist pitch of each adjacent layer can be appropriately selected in consideration of the adjustment items described above. For example, in each adjacent layer, when the value with the larger absolute value of the twist pitch is more than 1 times the value with the smaller absolute value of the twist pitch, the twisted wires 20 and 20 constituting each layer intersect. It is easy to arrange in a state and to have more points that are in point contact with each other. If there are many point contact locations, when the connecting member is crimped to the conductor 2 as described above, it is expected that the wires 200 and 200 can easily conduct each other. Although the ratio of the above-mentioned twist pitch can be selected as appropriate, it can be, for example, 4.5 times or less, preferably 4 times or less, and further 3 times or less.

≪Element crossing angle≫
As another example of the twisted wire assembly, one having at least one set of the inner layer and the outer layer in which the intersecting angles θi and θo with respect to the axis L of the conductor 2 in the strands 200i and 200o constituting the adjacent layers is different is given. It is done. Hereinafter, the crossing angles θi and θo will be described with reference to FIG. In FIG. 3, for convenience of explanation, the axis of the stranded wire 20i constituting the inner layer is arranged in parallel to the axis L of the conductor 2, and the stranded wire 20o constituting the outer layer is formed on the stranded wire 20i. The superimposed state is shown schematically.

  Each strand 200i constituting the stranded wire 20i included in the inner layer is twisted at a predetermined twist angle, and arranged in an intersecting state with the axis L of the conductor 2. The intersection angle θi is an angle that intersects the axis L of the conductor 2 in the strand 200i. The outer layer provided on the outer periphery of the inner layer is a twisted wire at a predetermined twist angle (in the twisted wire 20 constituting the outer layer, an angle intersecting with the axis of the twisted wire group located inside the outer layer). 20o is twisted together. Each strand 200o constituting this outer stranded wire 20o is arranged in an intersecting state with the axis L of the conductor 2. The intersection angle θo is an angle that intersects the axis L of the conductor 2 in the strand 200o. In FIG. 3, a straight line (L) parallel to the axis L is shown for easy understanding.

  In the case of only one outer peripheral layer and a single-core configuration, if the central stranded wire 2c that is the inner layer is a collective twist, the crossing angle θi of the strands 200 constituting the central stranded wire 2c, or the outermost layer if concentric stranded The crossing angle θi in the constituting strand 200, or the crossing angle θi in the strand 200 positioned on the outermost side of the multi-core stranded wire formed by twisting a plurality of central stranded wires 2c in a multi-core configuration with only one outer peripheral layer. And the crossing angle θo of the strands 200 constituting the outer layer formed by the outer peripheral stranded wire 21 is different (this form is called γ). When two or more outer peripheral layers are provided, at least one of the form γ and the following form δ is satisfied. Form δ is defined by the crossing angle θi of the strands 200i in the stranded wire 20i constituting the inner layer and the outer side in at least one inner / outer layer of “a set of two layers adjacent to each other” selected from the outer peripheral layer The crossing angle θo of the strand 200o in the stranded wire 20o constituting the layer is different (for example, the crossing angle θi in the inner layer formed by the outer peripheral stranded wire 21 and the crossing angle θo in the outer layer formed by the outer peripheral stranded wire 22 are different. Form). When the intersecting angles θi and θo are different, the strands 200i and 200o constituting the adjacent inner and outer layers are arranged in an intersecting state as described above, and include many points that are in point contact with each other. Therefore, when a connecting member such as a terminal is pressure-bonded to the conductor 2 at an arbitrary position of the electric wire 1, the natural oxide film on the surface of the element wire 200 is destroyed by pressing each other at the point contact point, and the element It is easy to ensure conduction between the lines 200 and 200.

  All the crossing angles in the constituent layers of the stranded wire assembly may be different. Or when the above-mentioned connection member is attached, the crossing angle can also be provided with the substantially same structural layer in the range in which the electrical resistance of the connection location of the connection member in the conductor 2 does not become excessive.

  The crossing angles θi and θo between adjacent layers can be selected as appropriate in consideration of the adjustment items described above. It is preferable to adjust the twist angle / twist direction of the stranded wire 20 constituting each layer, the twist angle / twist direction of each layer, etc. so that the desired crossing angles θi, θo are obtained. In particular, when a set of inner and outer layers having different intersection angles θi and θo is included, the larger absolute value of the intersection angles θi and θo in the inner and outer layers is 1.5, which is the smaller absolute value of the intersection angle. It is preferable that it is twice or more. This is because the strands 200i and 200o constituting the inner and outer layers are easily arranged in an intersecting state and more points are in point contact with each other. Since there are many point contact locations, it is expected that when the connecting member is crimped to the conductor 2 as described above, it is easy to conduct the wires 200 and 200. The larger the ratio of the above-mentioned intersection angles, the easier it is to increase the number of point contact locations. Manufacture is easy when the ratio of the above-mentioned crossing angles is 4 times or less.

  As yet another example of the twisted wire assembly, the twisted wire assembly includes at least one set of the inner layer and the outer layer in which the twist pitch is different and the crossing angles θi and θo with respect to the axis L of the conductor 2 in the strand 200 are different. Can be mentioned. In this form, when the stranded wires 20 and the strands 200 constituting the adjacent inner and outer layers are easily arranged in an intersecting state, it is easier to have more point contact points, and when the connecting member is crimped to the conductor 2, It is expected that the lines 200 and 200 are more easily connected.

≪Twist direction≫
Since the twisted wire assembly includes a set of inner and outer layers having different twist pitches and crossing angles θi and θo as described above, for example, the twist directions of all the constituent layers can be made equal. Alternatively, the stranded wire assembly can include at least one set of inner and outer layers in which the twist directions of adjacent layers are different. Since the twisting directions are different, the twisted wires 20 and 20 constituting each layer are arranged in an intersecting state and easily have a point contact with each other. For example, in the case where a twisted wire assembly is composed of twisted wires 20 having substantially the same twist pitch, twist direction, twist angle, etc., if the twist directions of adjacent inner and outer layers are different, the twisted wires 20 and the strands 200 are mutually connected. It is possible to reliably have a point contact point. When the inner and outer layers having different twist directions are also the inner and outer layers having different twist pitches, it is expected that the above-described point contact locations are more surely and more likely to be provided. In these forms, when a connection member such as a terminal is crimped to the conductor 2 at an arbitrary position of the electric wire 1, the natural oxide film on the surface of the element wire 200 is destroyed by pressing each other at the point contact point. Thus, it is easy to ensure conduction between the strands 200 and 200.

  Forms in which the twisted wire assemblies have different twist directions for each layer (for example, S twist, Z twist, S twist, Z twist,... In order from the inside) Example, S twisted, S twisted, Z twisted, Z twisted, S twisted, S twisted, etc., in order from the inside, with only one set of inner and outer layers with different twisting directions (eg, S twisted, Z twisted In addition to the two-layer structure, there are multiple layers of S-twisted layers in order from the inside, and one or more layers of Z-twisted layers thereon. It is preferable that the set of inner and outer layers having the same twist direction have different twist pitches. Alternatively, it is preferable that the sets of inner and outer layers having the same twist direction have different intersection angles θi and θo by adjusting the twist angle of each twisted wire 20 or the like. In the constituent layers of the stranded wire assembly, it is considered that it is preferable that at least one of the twist pitch, the crossing angles θi and θo, and the twist direction is different between the layers adjacent to each other inside and outside.

・ Characteristics ・ ・ Electrical resistance The electric wire 1 is cut at an arbitrary position to remove the insulating coating 3 to expose the conductor 2, and the end of the conductor 2 is crimped or compressed to be a terminal or branch connection member When a connection member (not shown) such as is attached, it is preferable that the electrical resistance of the connection portion of the connection member in the conductor 2 is low. Specifically, the electrical resistance is preferably equal to or less than the electrical resistance of the conductor 2.

.. Mechanical properties, etc. At least one of the tensile strength of the strands 200 constituting each stranded wire 20 is 70 MPa or more and 350 MPa or less, preferably 80 MPa or more and 320 MPa or less, and the elongation at break is 3% or more, preferably 5% or more. The form to fill is mentioned. When the tensile strength satisfies the above range, the strength is high. When the elongation at break satisfies the above range, bending or the like is easily performed. When both the tensile strength and the elongation at break satisfy the above ranges, they have high strength and high toughness, and are easy to bend and are not easily broken. Further, when a connection member such as a terminal is attached by pressure bonding or the like, the degree of strength increase due to work hardening is large, and the adhesion between the conductor 2 and the connection member is excellent. It is advisable to adjust the type and amount of additive elements of the Al alloy and the production conditions (drawing degree, softening conditions, etc.) so that the tensile strength and elongation at break satisfy the above ranges (this point is the conductivity described later, 0 The same applies to 2% proof stress).

  The higher the tensile strength of the strand 200 constituting each stranded wire 20 is in the above range, the better the strength is, and the more difficult it is to break, and the lower the range is, the easier it is to increase the elongation at break and conductivity. If the strand 200 is an aluminum wire, for example, the tensile strength is high when it is a hard material (typically a tempered H material). If the strand 200 is an aluminum alloy wire, it is easier to increase the tensile strength than the aluminum wire. The tensile strength can be 110 MPa or more and 200 MPa or less, 115 MPa or more and 180 MPa or less, and 115 MPa or more and 160 MPa or less.

  The higher the breaking elongation of the strand 200 constituting each stranded wire 20 is in the above range, the better the flexibility and toughness, the easier it is to bend, and the more difficult it is to break, and the lower the range, the higher the tensile strength. easy. If the strand 200 is an aluminum wire, for example, a soft material (typically a tempered O material) is excellent in elongation. If the strand 200 is an aluminum alloy wire, the elongation can be increased by the softening treatment or the like as described above. The elongation at break can be 5% or more, further 10% or more, 15% or more, 20% or more, or 25% or more.

  The strands 200 constituting each stranded wire 20 preferably have a high 0.2% proof stress. This is because, when the tensile strength is the same, the higher the 0.2% proof stress, the better the adhesive strength with a connection member such as a terminal. The specific 0.2% proof stress is preferably 40 MPa or more, and can be 50 MPa or more, and more preferably 60 MPa or more.

  It is preferable that the conductivity of the strand 200 constituting each stranded wire 20 and the conductor 2 composed of the strand 200 is higher, and 55% IACS or more, more preferably 58% IACS or more, 59% IACS or more, 60% IACS or more is preferable. .

-Shape The cross-sectional shape of the conductor 2 can be selected as appropriate. 1 and 2 show the shape as twisted together, but a compressed twisted wire assembly formed by compression molding can be used. Examples of the cross section of the compressed stranded wire assembly include a curved surface shape such as a circular shape and an elliptical shape, and a polygonal shape such as a rectangular shape and a hexagonal shape.

Insulating coating The insulating coating 3 is made of a resin having insulating properties, flexibility, heat resistance, water resistance, etc., typically polyvinyl chloride (PVC), polyethylene, cross-linked polyethylene (PE), or the like. The thickness of the insulating coating 3 can be appropriately selected according to the cross-sectional area of the conductor 2 and the like.

[Wire production method]
The electric wire 1 can be typically manufactured by forming the insulating coating 3 on the outer periphery of the conductor 2 by extrusion or the like. As a basic manufacturing method of the electric wire 1, a known manufacturing method can be used.

  The pure aluminum wire or the Al alloy wire constituting the element wire 200 can be typically manufactured through processes of casting, rolling, wire drawing, and appropriate softening treatment (may be during wire drawing). If the softening treatment is performed to make it easy to stretch to some extent, it is easy to reduce disconnection during wire drawing or to twist in the next twisting step. The twisted wire 20 can be manufactured by preparing a predetermined number of strands 200 and twisting them according to a predetermined twist pitch, twist direction, twist angle, and the like. A twisted wire assembly can be manufactured by preparing a predetermined number of twisted wires 20 and twisting them according to a predetermined twist pitch, twist direction, twist angle, and the like. The stranded wire 20 or the stranded wire assembly can be appropriately softened. As a basic manufacturing method of the strand 200, the stranded wire, and the stranded wire assembly, a known wire manufacturing method, stranded wire manufacturing method, stranded wire assembly manufacturing method, and the like can be used.

  The conditions for the softening treatment described above may be adjusted within a range in which the finally obtained stranded wire assembly has a predetermined tensile strength, elongation at break, electrical conductivity, and the like. As the softening treatment, either batch treatment or continuous treatment can be used. Examples of the batch processing conditions include a heating temperature of about 250 ° C. to 500 ° C. and a holding time of about 0.5 hours to 6 hours. When the atmosphere of the softening treatment is an atmosphere having a low oxygen content such as an air atmosphere or a non-oxidizing atmosphere, oxidation of pure aluminum wire or Al alloy wire can be reduced. Examples of the non-oxidizing atmosphere include a reduced pressure atmosphere, an inert gas atmosphere, a reducing gas atmosphere containing hydrogen, carbon dioxide gas, and the like and an inert gas. In the Al alloy wire having a specific composition containing Fe, the Al alloy wire is easily deformed when the connecting member is crimped to the conductor 2 by performing a softening process. In addition to being easy to increase, the degree of improvement in strength due to work hardening of the conductor 2 is likely to increase, and the fixing force between the conductor 2 and the connecting member can be easily increased.

[effect]
Although the electric wire 1 of Embodiment 1 is provided with the conductor 2 of a large area, since the conductor 2 is comprised by Al etc., it is lighter than the case where a copper conductor is provided. Therefore, when using the electric wire 1 for indoor wiring, for example, the burden on the operator at the time of laying can be reduced. And, the wire 1 of the first embodiment, since the conductor 2 is as large as 20 mm ^2, greater than many strands number constituting the conductor 2 and the connection member, such as a terminal to the conductor 2 at any position is crimped and the like, There may be many strands 200 that cannot directly contact the connecting member. However, the electric wire 1 of Embodiment 1 is a twisted wire assembly in which a plurality of twisted wires 20 are twisted together, and the strands 200 and 200 between the strands 200 and 200 as described above with a twist angle and a crossing angle with the conductor 2 as a specific range. It is easy to take continuity. Therefore, even when the connection member is attached to the conductor 2 at an arbitrary position, the electric wire 1 of the first embodiment is less likely to vary in the electrical resistance of the connection portion of the connection member in the conductor 2, and can easily take a stable value. 2 and the connection member are also excellent in conductivity. These effects will be specifically described in the following test examples.

[Test Example 1]
For wires that have a conductor made of a twisted wire assembly made of pure aluminum made of Al wire and a wire made of an Al alloy wire made of aluminum alloy, the mass and the crimp terminal The electrical resistance in the mounted state was examined.

Compositions (1) to (7) of the Al alloy wire used in this test are shown below (the balance is Al and inevitable impurities). The unit of content of each element is mass%.
(composition)
(1) 2.0% Fe
(2) 1.0% Fe, 0.2% Mg, 0.02% Ti, 0.004% B
(3) 1.0% Fe, 0.2% Mg, 0.04% Si, 0.03% Ti, 0.005% B
(4) 0.1% Fe, 0.05% Cu, 0.02% Ti, 0.004% B
(5) Fe 0.8%, Cu 0.02%
(6) 0.001% Fe, 0.02% Ti, 0.004% B
(7) Fe 0.6%, Mg 0.3%, Si 0.2%, Cu 0.05%, Mn 0.005%, Y 0.03%, Ti 0.01 %
(8) Pure aluminum

  The melts of the above compositions (1) to (8) are prepared, and an Al wire and an Al alloy wire having a wire diameter of 0.45 mmφ are prepared through the steps of casting, rolling, wire drawing, and appropriate softening treatment in order. Regarding the Fe—Mg—Al alloy wire having the composition (2) and the Al wire having the composition (8), those subjected to the softening treatment and those not subjected to the softening treatment are prepared.

  The tensile strength (MPa), 0.2% proof stress (MPa), elongation at break (%), and electrical conductivity (% IACS) of the produced Al wire and Al alloy wire are measured as follows. The tensile strength, 0.2% proof stress, and elongation at break are measured using a general-purpose tensile tester in accordance with JIS Z 2241 (Metal material tensile test method, 1998). The conductivity is measured by a bridge method or the like. As a result, the Al wire and the Al alloy wire of each sample have a tensile strength of 70 MPa to 350 MPa, a breaking elongation of 3% or more, a 0.2% proof stress of 40 MPa or more, and a conductivity of 55% IACS or more. . The characteristics for each composition are extracted and shown in Table 1.

Using the Al wire and Al alloy wire of each prepared sample as a strand, a collective twisted stranded wire is prepared. A plurality of stranded wires of each sample are prepared and twisted concentrically to produce a stranded wire assembly having a cross-sectional area (mm ² ) shown in Table 2. Tables 2 to 4 show the structure of the stranded wire structure and the twisting conditions. Here, a stranded wire structure including one central stranded wire and one or more outer peripheral layers is used. Here, the twist direction of each layer is S-twist.

Table 2 shows the cross-sectional area (mm ² ), the composition of the strand used for each stranded wire, the strand diameter (mmφ), the number of strands (pieces), the number of stranded wires in each layer, for the strand assembly of each sample. (Book). In Table 2, for example, “center 1, outer 17 and outer 2 12” indicate the position of the constituent layers and the number of twisted wires, the number of twisted wires of the center twisted wire is 1, and the first layer of the outer peripheral layer is twisted. This means that the number of wires is 7, and the number of stranded wires in the second layer of the outer peripheral layer is 12.

  Table 3 shows the twist angle (°), the twist pitch (mm), the twist angle (°) of each layer of the outer peripheral layer, the twist in the outer peripheral twist wire constituting the central twisted wire and the outer peripheral layer. The pitch (mm) is shown.

  Table 4 shows the crossing angle (°) with respect to the axis of the strand assembly (conductor) in the strands constituting each layer for the strand assembly of each sample. In Table 4, “center” means a central stranded wire, and “outside 1”, “outside 2”, and “outside 3” mean the first, second, and third layers of the outer peripheral layer in this order. Further, for the stranded wire assembly of each sample, at the crossing angle of each layer adjacent to the inside and outside, the magnification (large crossing angle / small crossing angle) of the large crossing angle (absolute value) with respect to the small crossing angle (absolute value) is obtained, Table 4 shows the “angle ratio”. The magnification of the maximum crossing angle with respect to the minimum crossing angle in the constituent layer of the stranded wire assembly of each sample is shown in Table 4 as “maximum”.

  An electric wire is manufactured by forming an insulation coating on the outer periphery of the stranded wire assembly of each sample as a conductor. Cut each wire at an arbitrary position, remove the insulation coating on the end of the wire, expose the end of the conductor, and crimp and attach a crimping terminal to this conductor. Measure electrical resistance. In this test, a known tin-plated copper product is used as the crimp terminal. The electrical resistance is measured according to JIS C 2805 (2010), 7.8 electrical resistance test, and the following ratio is obtained. This ratio (%) is the difference between the electrical resistance of the conductor and the electrical resistance of the conductor, and the difference between the electrical resistance of the conductor and twice the electrical resistance of the crimped terminal in the above-mentioned conductor { Electrical resistance) / electrical resistance of the conductor} × 100. The ratio (%) is shown in Table 4. Table 4 shows a case where a wire (soft material) subjected to softening treatment is used for the composition (2), and a wire (hard material) not subjected to softening treatment is used for the composition (8).

Although all of the twisted wire assemblies using the strands of the above compositions (1) to (8) have a cross-sectional area of more than 20 mm ^2, they are made of an aluminum alloy and therefore compared to a case of being made of annealed copper. Thus, the weight can be reduced by about 50% or more.

  Moreover, as shown in Table 4, all the electric wires of each sample using the above-described twisted wire assembly as a conductor have the above-mentioned ratio of 100% or less, and the electric resistance of the connection portion of the crimp terminal in the conductor is the conductor itself. The electrical resistance is equal to or less than the electrical resistance. One of the reasons why such a result was obtained is considered as follows. In the electric wire of each sample, in the stranded wire assembly constituting the conductor, the stranded wires constituting the inner and outer layers having different twist pitches and crossing angles can be arranged in a crossed state, and the number of points in contact can be increased. It is considered that at these point contact locations, the strands are easily pressed together, the natural oxide film formed on the strand surface is broken, and the conduction between the strands is excellent.

Moreover, the following can be understood from the results shown in Tables 1 to 4.
(1) Even when the cross-sectional area is larger than 30 mm ² , 50 mm ² or larger, 100 mm ² or larger and the number of strands is larger, good conduction between the strands can be obtained.
(2) Even if the inner and outer layers have the same twisting direction and the same twisting pitch, the electrical resistance at the above-mentioned connection points can be reduced if the crossing angle with the conductor in the strands constituting each layer is different (No. 1 -1 to No. 1-8, etc.).
(3) By providing the set of inner and outer layers in which the angle ratio of the crossing angles in the adjacent inner and outer layers satisfies 1.5 times or more and 4 times or less, the electrical resistance at the above-mentioned connection location can be lowered. This is the case with, for example, sample no. 1-11 (1.5 times, 93%) and No.1. 1-12 (1.2 times ≦ 1.5 times, 96%) is confirmed by comparison and reference. Moreover, in the above-mentioned range, the larger the angle ratio, the lower the electrical resistance of the above-mentioned connection location (for example, see Sample No. 1-8 to No. 1-11, No. 1-13, 1-14 for comparison) ). From this, it can be said that the larger the angle ratio in the above range, the more the points where the stranded wires constituting the inner and outer layers are arranged in a crossing state and are in point contact.

  From the above description, when a large-area conductor is made of a twisted wire assembly such as Al, when a connecting member such as a terminal is crimped to the conductor by changing the twist pitch or crossing angle of each adjacent layer It was shown that the electrical conductivity between the conductor and the connecting member is excellent.

  The present invention is not limited to these exemplifications, but is defined by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. For example, for the electric wires shown in Embodiment 1 and Test Example 1, the cross-sectional area of the conductor, the cross-sectional area of the strands constituting each stranded wire, the number of strands, the twist direction, and the stranded wire constituting the stranded wire assembly The cross-sectional area, the number of stranded wires, the twisting direction, the thickness of the insulating coating, the constituent material of the insulating coating, and the like can be changed.

DESCRIPTION OF SYMBOLS 1 Electric wire 2 Conductor 20, 20i, 20o Stranded wire 200, 200i, 200o Strand 2c Center twisted wire 2o, 21, 22, 23 Outer periphery twisted wire 3 Insulation coating

Claims (8)

An electric wire comprising a conductor and an insulating coating covering the outer periphery of the conductor,
The cross-sectional area of the conductor is greater than 20 mm ² ;
The conductor is
A twisted wire assembly in which a plurality of strands made of aluminum or an aluminum alloy are twisted together, and a plurality of twisted wires are twisted together. At least one center twisted wire and the outer periphery of the center twisted wire are twisted and layered It is provided with a peripheral stranded wire to be arranged,
An electric wire including at least one of a set of inner and outer layers having different twist pitches of adjacent layers, and a set of inner and outer layers having different intersection angles with respect to the axis of the conductor in the strands constituting the adjacent layers.   The electric wire according to claim 1, wherein when the connection member is attached by crimping or compressing the conductor, the electrical resistance of the connection portion of the connection member in the conductor is equal to or less than the electrical resistance of the conductor.   The electric wire according to claim 1, wherein the stranded wire assembly includes two or more outer peripheral stranded wires.   The electric wire according to claim 3, wherein the outer peripheral layer formed by the outer peripheral twisted wire includes a set of inner and outer layers having different twisting directions of adjacent layers.   It includes a set of inner and outer layers having different crossing angles, and the value of the larger absolute value of the crossing angle in the inner and outer layers is 1.5 times or more and 4 times or less of the value of the smaller absolute value of the crossing angle. The electric wire according to any one of claims 1 to 4. The electric wire according to any one of claims 1 to 5, wherein a cross-sectional area of each strand is 0.02 mm ² or more and 0.5 mm ² or less.   At least one strand of the plurality of strands contains Fe in an amount of 0.005 mass% to 2.2 mass%, and the balance is made of an aluminum alloy that is Al and inevitable impurities. The electric wire according to claim 6.   The aluminum alloy further includes one or more elements selected from Mg, Si, Cu, Zn, Ni, Mn, Ag, Cr, Zr, and Y in total of 0.005% by mass to 1.0% by mass. The electric wire according to claim 7, which is contained below.

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