Aluminum electric wire and method for manufacturing the same

Abstract

To provide an aluminum wire which has similar conductivity to that of an insulated wire having a copper conductor and prevents an increase in a wire outer diameter.SOLUTION: In aluminum wires 1 and 1A in which aluminum conductors 10 and 10A composed of 37 or 19 aluminum core wires 20 and 20A containing 99 mass% or more of aluminum are covered with an insulating resin film 30, the aluminum conductors 10 and 10A are configured by stranding the aluminum core wires 20 and 20A in a non-compression state, cross-sectional areas of the aluminum conductors 10 and 10A are 2.5 mm2 or more and less than 17 mm2, and the insulating resin coating has a thickness that is 10% or more and 20% or less of a conductor outer diameter of the aluminum conductors 10 and 10A.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an aluminum electric wire formed by coating an aluminum-based conductor with an insulating resin coating, and a method for manufacturing the aluminum electric wire.

Background Art

[0002] For example, a large number of insulated electric wires are routed in automobiles, and there is a demand for lightweight insulated electric wires in response to the requirement for weight reduction of automobiles. A general insulated electric wire is composed of a conductor formed by bundling conductive core wires (strands) and an insulating resin coating that coats the conductor. Conventionally, a conductor composed of a copper or copper alloy core wire with excellent conductivity (hereinafter referred to as a copper conductor) has generally been used.

[0003] On the other hand, in response to the above-mentioned weight reduction requirement, Patent Document 1 proposes an aluminum electric wire using a conductor formed by bundling aluminum or aluminum alloy core wires (hereinafter referred to as aluminum-based core wires) (hereinafter referred to as an aluminum conductor), and such an aluminum electric wire is described as being lighter than an insulated electric wire using a copper conductor of the same diameter.

[0004] However, an aluminum conductor has lower conductivity than a copper conductor (about 60%), and in order to ensure the same level of conductivity as an insulated electric wire composed of a copper conductor, it is necessary to set the cross-sectional area of the aluminum conductor to be equal to or larger than the cross-sectional area of the copper conductor.

[0005] Thus, an aluminum electric wire having an aluminum conductor that ensures the same level of conductivity as a copper conductor has a larger cross-sectional area of the aluminum conductor than that of a copper conductor, that is, a larger cross-sectional diameter, so the outer diameter of the aluminum electric wire also becomes larger. Specifically, by making the thickness of the aluminum conductor about 1.5 to 1.7 times the thickness of the copper conductor, the current capacity can be made the same, and a wire having the same level of conductivity can be obtained.

[0006] When the outer diameter of the electric wire increases, the connection portion between the terminal and the electric wire, such as the crimping portion in the crimp terminal to which the insulated electric wire is connected, also increases, and there is a possibility that the terminal cannot be inserted into the cavity (terminal insertion hole) in the connector housing of the connector configured by mounting the terminal.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] In view of the above problems, an object of the present invention is to provide an aluminum electric wire having the same conductivity as an insulated electric wire having a copper conductor and whose outer diameter does not increase.

Means for Solving the Problems

[0009] The present invention is an aluminum electric wire in which a conductor composed of a plurality of aluminum-based core wires containing 99% by mass or more of aluminum is coated with an insulating resin coating, and 19 or 37 of the aluminum-based core wires are concentrically twisted in a non-compressed state and at the same pitch to form the conductor. When the conductor is composed of 19 of the aluminum-based core wires, the outer diameter of the aluminum-based core wire is 0.56 mm or more and 1.06 mm or less. When the conductor is composed of 37 of the aluminum-based core wires, the outer diameter of the aluminum-based core wire is 0.40 mm or more and 0.76 mm or less, and the cross-sectional area of the conductor is 5 mm 2 or more and 17 mm 2 less, The eccentricity of the insulating resin coating is 70% or more, and the insulating resin coating has a thickness of 10% or more and 20% or less of the outer diameter of the conductor. characterized by the above.

[0010] According to the present invention, it is possible to configure an aluminum electric wire having the same conductivity as an insulated electric wire having a copper conductor and whose outer diameter does not increase. Specifically, in an aluminum electric wire in which a conductor composed of a plurality of aluminum-based core wires with 99% by mass or more of aluminum is coated with an insulating resin coating, by concentrically twisting the aluminum-based core wires in a non-compressed state and at the same pitch to form the conductor, the flexibility of the aluminum-based core wires is high, so the conductor has excellent flexibility, and the aluminum-based core wires do not come apart even when coated with the insulating resin, and a conductor in an orderly aligned state in cross-section can be formed.

[0011] On the other hand, although the outer diameter of the electric wire does not increase because the conductor is coated with an insulating resin coating with a small thickness relative to the outer diameter of the conductor, for example, in the case of a stranded conductor in which the core wires are stranded in a stranding method such as bunch stranding or rope stranding (composite stranding), the separated core wires may bite into the insulating resin coating, or the insulating resin coating may be eccentric, resulting in a locally thinner insulating resin coating, and there is a risk that the performance (required performance) required for the insulating resin coating, such as insulation and strength, cannot be ensured.

[0012] In contrast, as described above, a conductor formed by concentrically twisting aluminum-based core wires at the same pitch has the aluminum-based core wires orderly aligned with each other in its cross-section, so even a thin insulating resin coating can surely ensure the required thickness.

[0013] In addition, by forming the conductor with 19 or 37 of the concentrically twisted aluminum-based core wires, an aluminum electric wire provided with a conductor configured in a stranding method according to a desired cross-sectional area can be formed.

[0014] Furthermore, since the eccentricity, which is the ratio of the thin part (hereinafter referred to as the minimum insulator thickness) to the thick part (hereinafter referred to as the maximum insulator thickness) of the conductor and the insulating resin coating in a cross-section orthogonal to the longitudinal direction, is 70% or more, the conductor will be arranged near the center in cross-section. As a result, the difference between the minimum insulator thickness and the maximum insulator thickness can be reduced. That is, the insulating resin coating coated so that the minimum insulator thickness becomes a predetermined thickness can reduce the thickness at the location of the maximum insulator thickness. Therefore, the outer diameter of the aluminum electric wire can be reduced.

[0015] When the thickness of the insulating resin coating is less than 10%, there is a risk that the required performance of the insulating resin coating, such as insulation and strength, cannot be satisfied. Conversely, when the thickness of the insulating resin coating is greater than 20% of the outer diameter of the conductor, there is a risk that the outer diameter of the wire will be larger than that of a copper wire with the same conductivity. In contrast, since the insulating resin coating has a thickness of 10% or more and 20% or less of the outer diameter of the conductor, it is possible to form an aluminum wire that has a desired conductivity and does not have a large outer diameter of the wire.

[0016] Furthermore, a conductor composed of a plurality of aluminum-based core wires has a larger outer diameter of the conductor than a conductor composed of copper-based core wires having the same conductivity, and there is a concern about a decrease in flexibility. However, since the aluminum-based core wire is composed of a flexible aluminum-based material having 99% by mass or more of aluminum, that is, a low hardness, the aluminum-based core wire itself has appropriate flexibility, and it is possible to form an aluminum wire having appropriate flexibility.

[0017] Also, when the aluminum wire is crimp-connected, for example, at the crimping portion of a crimp terminal, it can be properly crimped and connected without damaging the crimping portion. Specifically, when a conductor is formed by twisting aluminum-based core wires having less than 99% by mass of aluminum, the hardness of the aluminum-based core wires increases. Therefore, when the conductor composed of the aluminum-based core wires is crimped at a predetermined crimping rate, the crimping portion of the crimp terminal may be damaged. However, by using a conductor composed of aluminum-based core wires containing 99% by mass or more of aluminum having a low hardness, the conductor can be properly crimped and connected without damaging the crimping portion to be crimped.

[0018] In addition, the aluminum-based core wires constituting the conductor can be more orderly aligned in cross-section, and the cross-sectional shape of the conductor can be stabilized in the longitudinal direction. Therefore, the thickness of the insulating resin coating can be made substantially the same on average, and even a thin insulating resin coating can surely secure the required thickness.

[0019] As another aspect of the present invention, the core wire diameters of the 19 or 37 aluminum-based core wires constituting the conductor may be the same. According to the present invention, since a conductor can be formed with one type of aluminum-based core wire, the error in the outer diameter of the conductor can be reduced. Furthermore, since it is not necessary to manufacture a plurality of types of aluminum-based core wires, the manufacturing process can be simplified and the manufacturing cost can be reduced.

[0020] Furthermore, when the aluminum-based core wires constituting the conductor are arranged in a regular hexagonal cross-section, the aluminum-based core wires arranged in the outer layer can be fitted between the aluminum-based core wires arranged in the inner layer, so that the core wires of the same diameter can be arranged more stably. That is, the core wires can be arranged more orderly.

[0021] As an aspect of the present invention, the cross-sectional area of the conductor may be 2.5 mm 2 or more and less than 17 mm 2 According to the present invention, since the cross-sectional area of the conductor is 2.5 mm 2 or more and less than 17 mm 2 it is possible to configure an aluminum electric wire having a desired conductivity and not increasing the outer diameter of the electric wire.

[0022] Specifically, since the conductivity of the aluminum-based core wire is lower than that of the copper-based core wire of the same diameter, when the cross-sectional area of the conductor composed of a plurality of aluminum-based core wires is less than 2.5 mm 2 it becomes difficult to configure an aluminum core wire having the same conductivity as the corresponding copper electric wire. Conversely, when the cross-sectional area of the conductor composed of a plurality of aluminum-based core wires is 17 mm 2 or more, although the same conductivity as that of the copper electric wire can be ensured, the flexibility may be impaired due to the increased rigidity of the conductor, and the bending performance of the electric wire may be reduced.

[0023] However, when the cross-sectional area of the conductor is 2.5 mm 2 or more and less than 17 mm 2 ​By being configured to be less than that, an aluminum wire having substantially the same outer diameter and current capacity as a copper electric wire can be obtained, and furthermore, desired bending performance can be maintained. That is, since the thickness of the insulating coating that coats the conductor can be made thin within a range where the conductor can be protected, it can have the same outer diameter as a copper electric wire having the same current capacity, and can have desired bending performance.

[0024] As an aspect of this invention, the insulating resin coating can be made to have a thickness of 7% or more and less than 14% of the outer diameter of the electric wire. According to this invention, an aluminum electric wire capable of ensuring the minimum wall thickness of the insulating resin coating can be configured.

[0025] Also, as an aspect of this invention, the insulating resin coating can have a tensile strength of 14 MPa or more, a heat distortion rate of 25% or less, a cold resistance of -15°C or less, and a volume resistivity of 1×10 12 Ω·cm or more at a temperature of 23°C. According to this invention, an aluminum electric wire can be configured in which the outer diameter of the electric wire does not increase, and the required performance of the insulating resin coating is satisfied without a decrease in the mechanical strength as the insulating resin coating.

[0026] Note that the above-mentioned "tensile strength", "heat distortion rate", "cold resistance", and "volume resistivity" are defined based on Japanese Industrial Standard JIS K 6723-2006 "Plasticized polyvinyl chloride compounds". Also, the temperatures serving as the standards for "tensile strength" and "volume resistivity" allow an error of ±0.5°C (the same shall apply hereinafter).

[0027] Also, as an aspect of this invention, the cross-sectional area of the conductor can be 5 mm 2 or more, and the insulating resin coating can have a thickness of 15% or less of the outer diameter of the conductor. According to the present invention, even with a thin insulating resin coating, the required thickness can be surely ensured, and an aluminum wire having the same conductivity as an insulated wire having a copper conductor and not increasing the outer diameter of the wire can be configured.

Advantages of the Invention

[0028] According to the present invention, an aluminum wire having the same conductivity as an insulated wire having a copper conductor and not increasing the outer diameter of the wire can be provided.

Brief Description of the Drawings

[0029]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0030] Figure 1 shows a schematic perspective view of the aluminum electric wire 1, and Figure 2 shows an explanatory view of the aluminum electric wires 1 and 1A. Specifically, Figure 2(a) shows a cross-sectional view of the aluminum electric wire 1, and Figure 2(b) shows a cross-sectional view of the aluminum electric wire 1A. In Figure 1, the aluminum conductor 10 inside the insulating resin coating 30 is illustrated by a dashed line. Figure 3 shows an explanatory view regarding the thickness of the insulating resin coating 30 in the aluminum electric wire 1, and Figure 4 shows a cross-sectional view of the copper electric wire 100.

[0031] The aluminum electric wire 1 shown in Figures 1 and 2(a) is configured by coating an aluminum conductor 10 formed by concentrically twisting 37 aluminum-based core wires 20 containing 99 mass% or more of aluminum in a non-compressed state with an insulating resin coating 30.

[0032] The so-called 5 sq (a wire with a conductor cross-sectional area of approximately 5 mm 2 , where "sq" means "mm 2 ". The same applies hereinafter.) The aluminum electric wire 1 having the same conductivity as the copper electric wire 100 (see Figure 4) is a wire of a size called so-called 8 sq. Specifically, 37 aluminum-based core wires 20 with a diameter of 0.52 mm are concentrically twisted to form an aluminum conductor 10 with an outer conductor diameter Φa of 3.64 mm, and the aluminum conductor 10 is coated with an insulating resin coating 30 with a wall thickness of 0.4 mm to form an aluminum electric wire 1 with a finished outer diameter of 4.4 mm.

[0033] Here, the outer conductor diameter Φ is measured by the measurement method described in 'JASO-D-618' and refers to the diameter of the circumscribed circle Fc of the substantially regular hexagon formed by the cross-section of the aluminum conductor 10 that constitutes the aluminum electric wire 1 (see Figure 3). Also, the wall thickness refers to the average value of the wall thickness of the insulating resin coating 30 that coats the aluminum conductor 10. Specifically, it refers to the average value of the value obtained by multiplying by 1 / 2 the difference between the outer diameter of the wire (finished outer diameter R) and the outer conductor diameter Φ at any plurality of points.

[0034] Also, as shown in Fig. 3, among the thick portions of the insulating resin coating 30 that coats the aluminum conductor 10 in the aluminum electric wire 1, the minimum thickness lc of the thinnest portion is defined as the minimum insulator thickness. On the other hand, among the straight lines connecting the minimum insulator thickness lc and the center of the aluminum conductor 10, the thickness of the coating on the side opposite to the side indicating the minimum insulator thickness, that is, the thickness lb of the thick portion on the above straight line is defined as the maximum insulator thickness.

[0035] Also, the ratio of the minimum insulator thickness (thickness lc) to the maximum insulator thickness (thickness lb) is taken as (lc / lb) (see Fig. 3). At positions that are not an integer multiple of the twist pitch in the longitudinal direction and where the length between the two farthest points is longer than the twist pitch, the minimum value of the data taken at three or more points (four points in the following example) is defined as the eccentricity. The eccentricity of the aluminum electric wire 1 in this embodiment is 78%.

[0036] Specifically, for the eccentricity, five aluminum electric wires 1 of a predetermined length are made. On a cross-section selected to satisfy the above conditions with respect to the longitudinal direction, a straight line (measurement line L) connecting the opposing vertices of the hexagon formed by the aluminum conductor 10 is extended to the outer circumference of the aluminum electric wire 1. The lengths of the thicknesses (thickness lb, thickness lc) of the insulating resin coating 30 between the aluminum conductor 10 and the aluminum electric wire 1 on this measurement line L are measured, and the ratio (lc / lb) of the thickness lc to the thickness lb is calculated as a percentage.

[0037] Here, since the aluminum conductor 10 is hexagonal, three measurement lines L can be drawn. The smallest value among the eccentricities calculated from these three measurement lines (L1 to L3) is defined as the eccentricity of the aluminum electric wire 1.

[0038] Note that the eccentricity is calculated in the same manner for the aluminum electric wire 1A described below.

[0039] As shown in Fig. 3(a), when the aluminum electric wire 1 is configured with 37 aluminum-based core wires 20 to form the aluminum conductor 10, one core wire (center core 11) is placed in the center, and 6 core wires (second layer 12), 12 core wires (third layer 13), and 18 core wires (fourth layer 14) are arranged in order from the center. The aluminum conductor 10 is formed by concentric stranding with the same stranding pitch Pa for the second layer 12, the third layer 13, and the fourth layer 14.

[0040] Also, the aluminum-based core wire 20 is made of aluminum with 99.7 mass% or more, has a conductivity of 61.2% IACS or more, a tensile strength of 70 to 120 MPa, and a tensile elongation of 16% or more. It is made of a so-called pure aluminum-based material (an aluminum-based material with a composition corresponding to the 1070 series of JIS H4000). However, it may also be made of an aluminum alloy material with Si of 0.10 mass% or less, Fe of 0.2 to 0.23 mass%, Cu of 0.16 to 0.23 mass%, Mn of 0.005 mass% or less, Mg of 0.12 to 0.15 mass%, Ti + V of 0.05 mass% or less, and the balance being 99 mass% or more of aluminum, having a conductivity of 58% IACS or more, a tensile strength of 90 MPa or more, and a tensile elongation of 8% or more. That is, as long as it is an aluminum alloy material with a purity of 99% or more and a conductivity of about 60%, the detailed configuration is not limited, and an aluminum conductor 10 having sufficient flexibility and desired conductivity can be manufactured as the material of the aluminum-based core wire 20 of the present invention.

[0041] The insulating resin coating 30 is an insulating resin coating made of polyvinyl chloride (hereinafter, PVC) having a tensile strength at 23°C of 19.6 MPa or more, a heat distortion rate of 25% or less, a cold resistance of -20°C or less, and a volume resistivity at 30°C of 3×10 12 Ω·cm or more.

[0042] In the aluminum electric wire 1 configured as described above, the total cross-sectional area of the aluminum conductor 10 with an outer diameter of 3.64 mm formed by concentric stranding of 37 aluminum-based core wires 20 with a diameter of 0.52 mm is 7.85 mm 2 and becomes. Further, the insulating resin coating 30 with a thickness of 0.4 mm has a thickness of 11%, which is 10% or more and 15% or less with respect to the aluminum conductor 10 having an outer diameter of 3.64 mm, and is configured with a thickness of 9%, which is 7% or more and less than 14% with respect to the aluminum wire 1 having a finished outer diameter of 4.4 mm.

[0043] On the other hand, as shown in Fig. 2(b), the aluminum wire 1A having the aluminum conductor 10A formed by concentrically stranding 19 aluminum-based core wires 20A is a wire of a size so-called 8 sq, which is about the same as the above-mentioned aluminum wire 1. The aluminum-based core wire 20A with a diameter of 0.73 mm is concentrically stranded 19 times to form the aluminum conductor 10A with an outer diameter Φb of 3.65 mm. The aluminum conductor 10A is coated with the insulating resin coating 30 with a thickness of 0.4 mm to form a finished outer diameter of 4.4 mm. Note that the eccentricity of the aluminum wire 1A is 80%.

[0044] When the aluminum conductor 10A is composed of 19 aluminum-based core wires 20A, one core wire (the center core 11A), six core wires (the second layer 12A), and 12 core wires (the third layer 13A) are arranged in order from the center, and the twisting pitch between the second layer 12 and the third layer 13 is the same and concentrically stranded to form the aluminum conductor 10A.

[0045] In the aluminum wire 1A configured as described above, the total cross-sectional area of the aluminum conductor 10 with an outer diameter Φb of 3.65 mm formed by concentrically stranding 19 aluminum-based core wires 20 with a diameter of 0.73 mm is 7.95 mm 2 becomes. Further, the insulating resin coating 30 with a thickness of 0.4 mm has a thickness of 11%, which is 10% or more and 15% or less with respect to the aluminum conductor 10A having an outer diameter of 3.65 mm, and is configured with a thickness of 9%, which is 7% or more and less than 14% with respect to the aluminum wire 1A having a finished outer diameter of 4.4 mm.

[0046] The copper wire 100 having the same conductivity as the aluminum wires 1 and 1A having the aluminum conductors 10 and 10A composed of these aluminum core wires 20 is, for example, as shown in FIG. 4, a wire of a size called so-called 5 sq, and 65 copper core wires 120 having a diameter of 0.32 mm are collectively stranded to form a copper conductor 110 having an outer conductor diameter of 3.0 mm, and the copper conductor 110 is coated with an insulating resin coating 30 having a thickness of 0.7 mm to form an outer diameter of 4.4 mm (see Table 3).

[0047] Thus, the total cross-sectional area of the copper conductor 110 composed of the copper core wires 120 having higher conductivity than the aluminum core wires 20 is 5.22 mm 2 which is smaller than the total cross-sectional area of 7.95 mm of the aluminum conductors 10 and 10A in the above-mentioned aluminum wires 1 and 1A, 2 but the copper conductor 110 and the aluminum conductors 10 and 10A have the same level of conductivity.

[0048] In other words, although the cross-sectional area of the aluminum conductors 10 and 10A in the aluminum wires 1 and 1A is larger than that of the copper conductor 110, the aluminum wires 1 and 1A can have substantially the same outer diameter as the copper wire 100 and have the same level of conductivity, that is, the allowable current.

[0049] Also, since the aluminum core wires 20 and 20A constituting the aluminum wires 1 and 1A are significantly lighter in specific gravity than the copper core wires 120 constituting the copper conductor 110 (about 1 / 3), the mass of the aluminum wires 1 and 1A can be reduced even if the total cross-sectional area of the aluminum conductors 10 and 10A constituted by the aluminum core wires 20 and 20A is large.

[0050] Furthermore, generally in a coated wire, the thickness of the insulating resin coating is designed so that the minimum thickness of the insulator can ensure a predetermined thickness. Since the eccentricity of the aluminum wires 1 and 1A is 70% or more, the difference between the minimum thickness of the insulator (thickness lc) and the maximum thickness of the insulator (thickness lb) can be reduced. As a result, the thickness of the insulating resin coating 30 at the position of the maximum thickness of the insulator (thickness lb) can be made thinner. Therefore, even for the aluminum wires 1 and 1A having a desired outer diameter, the aluminum conductors 10 and 10A can be surely protected by the insulating resin coating 30, and the cross-sectional outer diameter of the aluminum wires 1 and 1A can be reduced.

[0051] Also, the insulating resin coating 30 is a PVC insulating resin coating having a tensile strength of 16.2 MPa or more, a heat distortion rate of 40% or less, a cold resistance of -17 °C or less, and a volume resistivity of 1 × 10 11 Ωcm or more at a temperature of 30 °C.

[0052] In this way, the aluminum conductors 10, 10A having an outer diameter larger than that of the copper conductor 110 with an outer diameter of 3.0 mm are coated with the insulating resin coating 30 having higher performance from the properties. More specifically, by coating the aluminum conductor 10 with the insulating resin coating 30 having a wall thickness of 0.4 mm, which is thinner than the wall thickness of 0.7 mm of the insulating resin coating 30, an aluminum wire 1, 1A having the same size as the copper wire 100 can be formed in terms of the outer diameter of the wire.

[0053] Hereinafter, the manufacturing apparatus and manufacturing method of the above-mentioned aluminum wire 1, 1A will be described. First, the manufacturing apparatus and manufacturing apparatus of the aluminum wire 1A will be described with reference to FIGS. 5 to 9.

[0054] Here, FIG. 5 shows a perspective view of the bobbin 3a with the aluminum-based core wire 20A wound around it, FIG. 6 shows a schematic view of the stranding machine 4a, FIG. 7 shows an enlarged perspective view of the second-layer twisting unit 5, FIG. 8 shows an explanatory view of the insulator resin coating machine 300 for coating the insulating resin coating 30 on the aluminum conductor 10A, and FIG. 9 shows a flowchart for explaining the manufacturing method of the aluminum conductor 10A in the first embodiment. FIG. 6 is a schematic view of the stranding machine 4a simplified so that it can be easily understood that the numbers of the second bobbin mounting portion 522 and the third bobbin mounting portion 612 for mounting the bobbin 3a are different. Regarding FIG. 8 in detail, FIG. 8(a) shows a schematic exploded perspective view of the insulator resin coating machine 300, FIG. 8(b) shows a schematic perspective view showing a cross section orthogonal to the traveling direction X so as to pass through the center of the insulator resin coating machine 300, FIG. 8(c) shows an enlarged view of the α portion of FIG. 8(b), and FIG. 8(d) shows a front cross-sectional view of the tip portion of the nipple 320 in FIG. 8(b) viewed from the traveling direction X. Note that in FIGS. 8(a) and 8(b), a part is represented by a dashed line so that the internal structure can be understood. A partial cross-sectional view is shown.

[0055] The aluminum conductor 10A configured as described above is manufactured using a bobbin 3a around which an aluminum-based core wire 20A, which is a soft core wire that has been pre-softened, is wound, a stranding machine 4a for stranding the aluminum-based core wires 20A, and a bobbin 3b for winding up the aluminum conductor 10A. Below, the configurations of these bobbins 3a, 3b and the stranding machine 4a will be described.

[0056] First, as shown in FIG. 5, the bobbin 3a integrally includes a shaft core (not shown) around which the aluminum-based core wire 20A is wound, and annular flanges 31, 31 provided at both ends of the shaft core.

[0057] The shaft core is formed in a cylindrical shape having a through hole 32 that penetrates in the axial direction. The flanges 31, 31 have their inner circumferences fixed to the outer circumference at the ends of the shaft core. Since the bobbin 3b has the same configuration as the bobbin 3a, the description thereof will be omitted.

[0058] Next, as shown in FIG. 6, the stranding machine 4a is configured by arranging, in this order, a second-layer stranding unit 5 for stranding the second layer 12, a third-layer stranding unit 6 for stranding the third layer 13, and a conductor winding unit 7 for winding up the aluminum conductor 10A.

[0059] Note that the direction in which the second-layer stranding unit 5, the third-layer stranding unit 6, and the conductor winding unit 7 are arranged, that is, the direction from the left side to the right side in FIGS. 6 and 7, is defined as the traveling direction X in which the aluminum-based core wire 20A travels.

[0060] As shown in FIG. 7, the second-layer twisting unit 5 includes a first bobbin mounting portion 51 for mounting a bobbin 3a around which an aluminum core wire 20A constituting the core 11 is wound, a second-layer twisting member 52 for mounting a bobbin 3a around which an aluminum core wire 20A constituting the second layer 12 is wound, and a second-layer gathering chuck 53 for gathering the second layer 12 on the core 11, which are arranged in this order in the advancing direction X.

[0061] The first bobbin mounting portion 51 includes a rotating shaft that is inserted through a through hole 32 of the bobbin 3a and rotatably mounts the bobbin 3a, and a rotation control portion that controls the rotation speed of the rotating shaft (not shown). The rotation control portion of the first bobbin mounting portion 51 can control the rotation speed of the rotating shaft to which the bobbin 3a is attached according to the rotation speed of the bobbin 3b that rotates by the rotation control portion of the conductor winding portion 7 described later, and can apply a desired tension to the unwound aluminum core wire 20A.

[0062] The second-layer twisting member 52 is integrally formed with a cylindrical shaft core 52a extending in the advancing direction X, a disk-shaped first flange 52b provided on the first bobbin mounting portion 51 side of the shaft core 52a, and a disk-shaped second flange 52c provided on the opposite side of the first bobbin mounting portion 51, and is provided with a rotation mechanism (not shown).

[0063] The shaft core 52a has a through hole 521 penetrating therethrough along the advancing direction X inside. This shaft core 52a supports the first flange 52b and the second flange 52c at a predetermined interval.

[0064] The first flange 52b is formed in a disk shape having a hole with a diameter equal to the outer diameter of the shaft core 52a at the center. The inner circumference of this first flange 52b is fixed to the outer circumference at the end of the shaft core 52a, and is provided with six second bobbin mounting portions 522 having the same configuration as the first bobbin mounting portion 51.

[0065] The six second bobbin mounting portions 522 are arranged at equal intervals on a concentric circle, and are arranged on the surface of the first flange 52b on the side of the second flange 52c so as to form a substantially regular hexagon when viewed from the advancing direction X.

[0066] Similar to the first flange 52b, the second flange 52c is formed in a disc shape having a hole with a diameter equal to the outer diameter of the shaft core 52a at the center. This second flange 52c is fixed to the outer periphery at the end of the shaft core 52a, and six insertion holes 523 through which the aluminum-based core wire 20A unwound from the bobbin 3a attached to the second bobbin mounting portion 522 is inserted are formed.

[0067] The six insertion holes 523 are each formed in a circular shape slightly larger than the diameter of the aluminum-based core wire 20A, and are arranged at equal intervals on a concentric circle, that is, at positions facing the second bobbin mounting portion 522 so as to form a substantially regular hexagon when viewed from the advancing direction X.

[0068] As described above, the number of the second bobbin mounting portions 522 coincides with the number of bobbins 3a attached to the second layer twisting member 52, and the number of insertion holes 523 coincides with the number of aluminum-based core wires 20A constituting the second layer 12. That is, the number of the second bobbin mounting portions 522, the insertion holes 523, the aluminum-based core wires 20A constituting the second layer, and the bobbins 3a around which the aluminum-based core wires 20A are wound coincide.

[0069] The rotation mechanism provided in the second layer twisting member 52 is a mechanism for rotating the second layer twisting member 52 around the central axis of the cylindrical shaft core 52a extending in the advancing direction X (for example, the arrow direction in FIG. 7), and is provided on the shaft core 52a. Note that the rotation mechanism is not limited to being provided on the shaft core 52a as long as it can rotate the second layer twisting member 52, and may be provided on the first flange 52b or the second flange 52c.

[0070] The second-layer collective chuck 53 is formed in a cylindrical shape having an outer diameter of the second layer 12, that is, an inner diameter equivalent to the diameter of the core 11 and the second layer 12, and collects the six aluminum-based core wires 20A that have passed through the insertion hole 523 around the core 11 that has passed through the through hole 521.

[0071] The third-layer twisting unit 6 is composed of a third-layer twisting member 61 and a third-layer collective chuck 62. Note that since the third-layer twisting member 61 and the third-layer collective chuck 62 have the same configuration as the second-layer twisting member 52 and the second-layer collective chuck 53 of the second-layer twisting unit 5, illustration thereof is omitted and a brief description will be given below.

[0072] The third-layer twisting member 61 integrally forms a shaft core 61a, a first flange 61b, and a second flange 61c, and is provided with a rotation mechanism (not shown). The shaft core 61a is formed in a cylindrical shape having a through hole penetrating therethrough along the traveling direction X inside (not shown).

[0073] The first flange 61b is provided with 12 third bobbin attachment portions 612, and the second flange 61c is formed with 12 insertion holes 613. These third bobbin attachment portions 612 and insertion holes 613 are arranged at positions facing each other so as to form a substantially regular hexagon when viewed from the traveling direction X, and between the third bobbin attachment portions 612 and insertion holes 613 provided at each vertex, the third bobbin attachment portions 612 and insertion holes 613 are provided at equal intervals one by one.

[0074] The rotation mechanism provided in the third-layer twisting member 61 has the same configuration as the rotation mechanism provided in the second-layer twisting member 52 described above, and is provided on the shaft core 61a. Note that the rotation mechanism is not limited to being provided only on the shaft core 61a, similar to the rotation mechanism provided in the second-layer twisting member 52.

[0075] The third-layer assembly chuck 62 is formed in a cylindrical shape having an inner diameter equal to the outer diameter of the third layer 13, that is, the outer conductor diameter Φb, and assembles the 12 aluminum-based core wires 20A that have passed through the insertion holes 613 around the second layer 12 that has passed through the through holes.

[0076] Similar to the first bobbin mounting portion 51, the conductor winding portion 7 includes a rotating shaft that is inserted into the through hole 32 of the bobbin 3b to rotatably mount the bobbin 3b, and a rotation control portion that rotates the rotating shaft (not shown in the figure). That is, the conductor winding portion 7 can wind the aluminum conductor 10A around the bobbin 3b attached to the rotating shaft by the rotation mechanism rotating the rotating shaft.

[0077] In the following description, for the sake of convenience, the rotation of the first bobbin mounting portion 51, the second bobbin mounting portion 522, the third bobbin mounting portion 612, and the conductor winding portion 7 is referred to as self-rotation, and the rotation of the second layer twisting member 52 and the third layer twisting member 61 is referred to as revolution.

[0078] The stranding machine 4a configured as described above forms the second layer 12 by twisting the second layer 12 outside the core 11 with the second layer twisting member 52 and the second layer assembly chuck 53, and forms the third layer 13 outside the second layer 12 with the third layer twisting member 61 and the third layer assembly chuck 62 to form the aluminum conductor 10A.

[0079] By controlling the rotation speed and the timing of the start of rotation of the second layer twisting unit 5 and the third layer twisting unit 6, and the conductor winding portion 7, etc., the aluminum-based core wires 20A can be twisted at a predetermined twisting pitch Pa, or a predetermined tension can be applied to the aluminum-based core wires 20A.

[0080] By coating the thus configured aluminum conductor 10A with an insulating resin (PVC) that becomes the insulating resin coating 30, the aluminum electric wire 1A can be manufactured. Hereinafter, an insulator resin coating machine 300 that coats an aluminum conductor 10A with an insulating resin coating 30 will be described with reference to FIG. 8. Note that FIG. 8 shows a cross-sectional view along the traveling direction X at the central position of the insulator resin coating machine 300.

[0081] As shown in FIG. 8, the insulator resin coating machine 300 is arranged along the traveling direction X, and includes a bottomed cylindrical main body portion 310 that is the main body portion of the insulator resin coating machine 300, a nipple 320 attached to the proximal end side of the central portion of the main body portion 310, and a die 330 attached to the end portion on the traveling direction side of the main body portion 310.

[0082] The main body portion 310 includes a cylindrical exterior body 311 that forms the outside of the insulator resin coating machine 300, and a cross head 312 attached to a through hole 311a provided in the central portion of the exterior body 311. In the exterior body 311, a resin reservoir portion 313 for storing a liquid PVC resin 30A that is the material of the insulating resin coating 30, and an insertion passage 314 that passes through the resin reservoir portion 313 and sends the liquid PVC resin 30A to the inside are formed.

[0083] The cross head 312 is a cylindrical cylinder fitted to the proximal end side in the traveling direction X of a through hole 311a formed in the central portion of the exterior body 311, and a conductor through hole 315 that is a through hole larger than the aluminum conductor 10A is formed in the central portion of the bottom surface.

[0084] The nipple 320 is a columnar body formed along the traveling direction X, and is configured in a frustum shape with a tapered tip as it goes in the traveling direction X. Note that a nipple side through hole 321 that is slightly smaller in diameter than the conductor through hole 315 and larger than the outer diameter of the aluminum conductor 10A is formed along the traveling direction X in the central portion of the nipple 320.

[0085] The die 330 is a cylindrical body having a circle with a diameter larger than the diameter of the cylindrical portion of the nipple 320 as the bottom surface, and a conical recess is formed on the proximal end side in the advancing direction X. A through-hole (resin molding hole 331) having a cross-sectional area twice as large as the outer diameter of the aluminum conductor 10A is formed in the central portion of the die 330.

[0086] As shown in FIG. 8, the insulator resin coating machine 300 having such a configuration has the crosshead 312, the nipple 320, and the die 330 arranged side by side along the advancing direction X. A passage 301 for the liquid PVC resin 30A to pass through is formed between the nipple 320 and the die 330, and an insulator resin reservoir 302 capable of storing the liquid PVC resin 30A is formed at the tip portion of the nipple 320.

[0087] A method for manufacturing the aluminum conductor 10A using the bobbins 3a and 3b and the stranding machine 4a configured as described above, and then coating the aluminum conductor 10A with the insulating resin coating 30 by the insulator resin coating machine 300 to manufacture the aluminum wire 1A will be described below. The following example is an example of manufacturing the aluminum wire 1A with the size of the aluminum conductor 10A being 8 sq.

[0088] As shown in FIG. 9, the aluminum conductor 10A is manufactured by performing a softening treatment step (step S1) for forming the aluminum-based core wire 20A subjected to the softening treatment, and then performing a stranding step (step S2) of stranding 19 aluminum-based core wires 20A. The aluminum wire 1A is manufactured through a coating step (step S3) of coating the aluminum conductor 10A with the insulating resin coating 30.

[0089] In the softening treatment step (step S1), the unsoftened core wire that has not been softened is wound around the bobbin 3a and left at a high temperature of about 350 degrees for about 5 hours to be softened, thereby forming the aluminum-based core wire 20A subjected to the softening treatment.

[0090] Note that the temperature and time in the softening treatment process can be set as appropriate as long as they can form the aluminum core wire 20A with the desired softness, not limited to the above settings. Furthermore, when using an aluminum core wire with the desired softness or a pre-softened aluminum core wire, the softening treatment process can be omitted.

[0091] In the stranding process (step S2), six aluminum core wires 20A that form the second layer 12 and twelve aluminum core wires 20A that form the third layer 13 are arranged outside the core 11, and the aluminum core wires 20A are sequentially stranded to manufacture the aluminum conductor 10A.

[0092] Specifically, in the stranding process (step S2), first, bobbins 3a around which the softened aluminum core wires 20A are wound are respectively attached to the first bobbin mounting part 51, the second bobbin mounting part 522, and the third bobbin mounting part 612.

[0093] The tips of the aluminum core wires 20A unwound from the bobbins 3a attached to each bobbin mounting part are passed through predetermined positions, bundled, and fixed to a bobbin 3b attached to the conductor winding part 7. When the fixing of the aluminum core wires 20A to the bobbin 3b is completed, while revolving the second layer stranding member 52 and the third layer stranding member 61 in the same direction, the first bobbin mounting part 51, the second bobbin mounting part 522, the third bobbin mounting part 612, and the conductor winding part 7 are rotated.

[0094] At this time, according to the rotation speed of the conductor winding part 7, the rotation speeds of the first bobbin mounting part 51, the second bobbin mounting part 522, and the third bobbin mounting part 612 are controlled to apply a tension of 10.6 N to each of the aluminum core wires 20A to be stranded. Note that the tension applied to the aluminum core wire 20A is not limited to 10.6 N, and can be set as appropriate within the range of 5.3 N or more and 23.85 N or less (the tension per unit cross-sectional area is 12.5 N / mm 2 or more and 56.3 N / mm 2 or less).

[0095] Further, in accordance with the rotation speed of the conductor winding portion 7, the revolution speeds of the second layer twisting member 52 and the third layer twisting member 61 are controlled to twist the aluminum core wire 20A at a twisting pitch Pa of 44.2 mm, which is about 12.1 times the outer diameter Φb of the conductor. In the present embodiment, by setting the revolution speeds of the second layer twisting member 52 and the third layer twisting member 61 to the same speed, the twisting pitch of the second layer 12 and the third layer 13 is set to 44.2 mm. The above-described twisting process (step S2) is performed until the aluminum conductor 10A reaches a desired length.

[0096] Next, the aluminum conductor 10A manufactured in the twisting process (step S2) is inserted into the conductor through-hole 315 provided in the central portion of the above-described insulator resin coating machine 300, and the aluminum conductor 10A is extruded along the traveling direction X from the proximal end side in the traveling direction X. As a result, the aluminum conductor 10A passes through the insulator resin reservoir portion 302 in which the liquefied PCV 30A is stored, and the insulating resin coating 30 is coated on the outer peripheral surface of the aluminum conductor 10A. Finally, by inserting the aluminum conductor 10A coated with the insulating resin coating 30 into the resin molding hole 331, the insulating resin film is molded to have a desired thickness, and the aluminum electric wire 1A can be manufactured (step S3).

[0097] Here, the inner diameter of the nipple-side through-hole 321 is slightly larger than the outer diameter Φa of the conductor of the aluminum conductor 10A manufactured by twisting the aluminum core wire 20A, but it can be appropriately changed according to the size of the target aluminum electric wire 1A.

[0098] For example, in the above-described embodiment, that is, when the size of the aluminum electric wire 1A is 8 sq, the clearance K between the outer diameter Φb of the conductor of the aluminum conductor 10A and the nipple-side through-hole 321 is set to 0.35 mm (see FIGS. 8(b), (c), and (d)). That is, the ratio of the clearance K to the outer diameter Φb of the conductor of the aluminum conductor 10A is set to 9.6%. Thus, by reducing the clearance K, when the aluminum conductor 10A is passed through the insulator resin coating machine 300, the aluminum conductor 10A can be disposed near the center of the aluminum electric wire 1A.

[0099] In addition, when the size of the aluminum wire 1A is 5 sq, the clearance K provided between the nipple-side through hole 321 and the aluminum conductor 10A is 0.4 mm, and the ratio of the clearance K to the outer diameter Φb of the conductor of the aluminum conductor 10A is set to be 14.3%. When the size of the aluminum wire 1A is 2.5 sq, the ratio of the clearance K to the outer diameter Φb of the conductor of the aluminum conductor 10A is set to be 14.3%.

[0100] Thus, by setting the clearance K between the aluminum conductors 10, 10A and the nipple-side through hole 321 to be 5% or more and 15% or less with respect to the outer diameters Φa, Φb of the aluminum conductors 10, 10A, the aluminum wires 1, 1A can be manufactured such that the aluminum conductors 10, 10A are arranged at the central portions of the aluminum wires 1, 1A.

[0101] Specifically, when the clearance K is less than 5% with respect to the outer diameters Φa, Φb of the conductors, the aluminum conductors 10, 10A may interfere with the nipple-side through hole 321, resulting in damage to the aluminum conductors 10, 10A or the possibility that the insulating resin coating 30 is not partially coated. Conversely, when the clearance K is greater than 15% with respect to the outer diameters Φa, Φb of the conductors, it becomes difficult to arrange the aluminum conductors 10, 10A at the center when inserted into the conductor through hole 315 provided in the central portion of the insulator resin coating machine 300, so there is a possibility that the aluminum conductors 10, 10A are arranged unevenly.

[0102] On the other hand, when the clearance K is 5% or more and 15% or less with respect to the outer diameters Φa, Φb of the conductors, the aluminum conductors 10, 10A can be arranged at the central portions of the aluminum wires 1, 1A without interfering with the nipple-side through hole 321.

[0103] Similarly, the inner diameter of the resin molding hole 331 can also be appropriately changed according to the thickness of the insulating resin coating 30, and the thickness of the insulating resin coating 30 can be appropriately changed to a desired thickness. Thereby, the aluminum electric wire 1A provided with the insulating resin coating 30 having a desired wall thickness can be manufactured. Note that the wall thickness of the insulating resin coating 30 is preferably 10% or more and 20% or less of the outer diameter Φb of the conductor.

[0104] Also, in manufacturing the 8 sq aluminum electric wire 1A, in the twisting step (step S2), a tension of 10.6 N which is 5.3 N or more and 23.85 N or less (the tension per unit cross-sectional area is 12.5 N / mm 2 or more and 56.3 N / mm 2 or less) is applied to the aluminum-based core wire 20A, whereby the aluminum conductor 10A twisted at a predetermined twist pitch Pa can be manufactured without slack.

[0105] Specifically, when a tension smaller than 5.3 N is applied to the aluminum-based core wire 20A or when the aluminum-based core wire 20A is twisted without applying tension, there is a possibility that the aluminum-based core wire 20A to be twisted becomes slack or the aluminum conductor 10A formed by twisting becomes slack. On the other hand, when a tension larger than 23.85 N is applied to the aluminum-based core wire 20A and twisted, the aluminum-based core wire 20A to be twisted may elongate or break.

[0106] In contrast, by applying a tension of 10.6 N which is 5.3 N or more and 23.85 N or less, preferably 7.95 or more and 13.25 N or less (the tension per unit cross-sectional area is 12.5 N / mm 2 or more and 56.3 N / mm 2 or less, preferably 18.8 N / mm 2 or more and 31.3 N / mm 2 or less) to the aluminum-based core wire 20A, it is possible to prevent the aluminum-based core wire 20A to be twisted and the twisted aluminum conductor 10A from becoming slack, and it is also possible to prevent the aluminum-based core wire 20A from elongating or breaking.

[0107] Note that the load applied to the aluminum core wire 20 such as the aluminum core wire 20A due to the tension is proportional to the cross-sectional area of the aluminum core wire. That is, the tension per unit cross-sectional area is 12.5 N / mm 2 or more and 56.3 N / mm 2 or less. It is preferable to apply tension to the aluminum core wire 20A so that the following conditions are met.

[0108] As a result, the aluminum core wire 20A can be twisted tightly at a twist pitch Pa of about 12.1 times, which is 8.6 times or more and 22.0 times or less of the outer diameter Φb of the conductor. Therefore, it is possible to manufacture the desired aluminum conductor 10A that prevents problems such as twisting disorder of the aluminum core wire 20A and the aluminum core wire 20A protruding to the outside. Specifically, when the twist pitch Pa is smaller than 8.6 times the outer diameter Φa of the conductor, the angle of the aluminum core wire 20A twisted with respect to the central axis of the aluminum conductor 10A becomes large, and there is a risk of twisting disorder in the aluminum core wire 20A.

[0109] On the other hand, when the twist pitch Pa is larger than 22.0 times the outer diameter Φa of the conductor, the twist length per pitch of the aluminum conductor 10A becomes long, and the twist load of the aluminum conductor 10A is dispersed. As the central axis of the aluminum core wire 20A and the aluminum conductor 10A approaches a parallel state, the aluminum core wire 20A constituting the aluminum conductor 10A may protrude to the outside of the aluminum conductor 10A.

[0110] In contrast, by setting the twist pitch Pa to about 12.1 times, which is 8.6 times or more and 22.0 times or less of the outer diameter Φa of the conductor, the aluminum core wire 20A can be twisted at a desired angle with respect to the central axis of the aluminum conductor 10A, and the twist load of the aluminum core wire 20A acting on the aluminum conductor 10A can be set to a desired twist load. Therefore, it is possible to suppress the occurrence of twisting disorder in the aluminum core wire 20A and the aluminum core wire 20A constituting the aluminum conductor 10A protruding to the outside of the aluminum conductor 10A.

[0111] As a result, a desired aluminum conductor 10A can be formed. Therefore, for example, when covering the outer circumference of the aluminum conductor 10A with an insulating coating, it is possible to prevent the insulating coating from being partially thinned due to the protrusion of the aluminum-based core wire 20A to the outside, and to have desired insulating performance.

[0112] Note that since the twisting pitch Pa of the aluminum conductor 10A is 12.1 times or more and 20.7 times or less the outer diameter Φa of the conductor, it is possible to form a desired aluminum conductor 10A that surely prevents problems such as twisting disorder of the aluminum-based core wire 20A and protrusion of the aluminum-based core wire 20A.

[0113] In the above example, the aluminum-based core wire 20A is an example in which a softening treatment is performed in advance, but it is not necessarily required to perform a softening treatment in advance, and an aluminum-based core wire without a softening treatment can also be used (see FIG. 10).

[0114] As shown in FIG. 10, the manufacturing method of the aluminum electric wire when using an aluminum-based core wire without a softening treatment is a twisting step (step T1) corresponding to step S2 with the aluminum-based core wire 20A that has been softened in advance, and then a softening treatment step (step T2) corresponding to step S1 with the aluminum-based core wire 20A that has been softened in advance is performed, and a coating step (step S3) of coating the softened (step T2) aluminum conductor with an insulating resin coating 30 is performed.

[0115] In this case, it is necessary to apply a tension of 26.5 N to 37.1 N (the tension per unit cross-sectional area is 62.5 N / mm 2 or more and 87.5 N / mm 2 or less) to the aluminum-based core wire. Also in this case, the aluminum-based core wire is not limited to being configured such that the twisting pitch is about 12.1 times the outer diameter of the conductor, and the twisting pitch may be 6.4 times or more and 16.9 times or less the outer diameter Φb of the conductor, and more preferably, 9.6 times or more and 15.4 times or less.

[0116] In this way, by using aluminum-based core wires without softening treatment and setting the twisting pitch to about 12.1 times, which is 6.4 times or more and 16.9 times or less of the outer diameter Φb of the conductor, it is possible to form a desired aluminum conductor that suppresses problems such as twisting disorder of the aluminum-based core wires and protrusion of the aluminum-based core wires to the outside.

[0117] Also, before coating the aluminum conductor formed by the aluminum-based core wires without softening treatment with the insulating resin coating 30, it is necessary to perform a softening treatment step (step T2) of leaving the bobbin around which the aluminum conductor is wound at a high temperature of 350 degrees for 5 hours to soften it. Note that the softening treatment step is not limited to after twisting aluminum-based core wires without softening treatment as in this example, and can also be performed after twisting aluminum-based core wires that have been softened.

[0118] In the above example, the manufacturing of the aluminum electric wire 1A with a size of 8 sq is described. However, for example, for the aluminum electric wire 1A with a size of 2.5 sq or more and 16 sq or less, by appropriately adjusting the tension applied to the aluminum-based core wires during manufacturing within the range of 12.5 N / mm 2 to 87.5 N / mm 2 per unit cross-sectional area, it is possible to manufacture the aluminum electric wire 1A corresponding to each size.

[0119] Next, the manufacturing apparatus for the four-layer aluminum electric wire 1 and the manufacturing apparatus will be described based on FIGS. 11 and 12.

[0120] As described above, the aluminum conductor 10 is composed of 37 aluminum-based core wires obtained by subjecting a pure aluminum-based material having a composition corresponding to 1070 of JISH4000 to softening treatment, arranged concentrically as shown in FIGS. 1 and 2(a), and has a four-layer structure with the center core 11 as the first layer, and is composed of an inner layer portion 111 formed by the center core 11, the second layer 12, and the third layer 13, and a fourth layer 14 which is the outermost layer outside the inner layer portion 111. As a result, the outer diameter Φa of the conductor becomes 3.64 mm, and the total cross-sectional area of the twisted aluminum-based core wires 20 is about 8.0 mm 2 (8 sq).

[0121] Further, the aluminum conductor 10 is composed of a core 11 (corresponding to the first layer), a second layer 12, a third layer 13, and a fourth layer 14 composed of 18 aluminum-based core wires 20 arranged outside the third layer 13. The core 11 to the third layer 13 form an inner layer portion 111, and the fourth layer 14 forms the outermost layer.

[0122] Furthermore, the aluminum conductor 10 is configured such that the twisting pitch is 31.7 mm, which is approximately 8.7 times the outer diameter Φa of the conductor. Note that the aluminum conductor 10 is not limited to being configured such that the twisting pitch is approximately 8.7 times the outer diameter Φa of the conductor. As long as the twisting pitch is 6.2 times or more and 15.7 times or less, more preferably 8.7 times or more and 14.8 times or less of the outer diameter Φa of the conductor, it is acceptable.

[0123] As shown in FIG. 11, the stranding machine 4b for stranding the aluminum conductor 10 is configured by arranging a second-layer stranding unit 5, a third-layer stranding unit 6, a fourth-layer stranding unit 8 for stranding the fourth layer 14, and a conductor winding unit 7 in this order in the advancing direction X.

[0124] The fourth-layer stranding unit 8 is composed of a fourth-layer stranding member 81 and a fourth-layer gathering chuck 82. Since the fourth-layer stranding member 81 and the fourth-layer gathering chuck 82 have the same configuration as the second-layer stranding member 52 and the second-layer gathering chuck 53 of the second-layer stranding unit 5, they are not shown in the figure and will be briefly described below.

[0125] The fourth-layer stranding member 81 integrally forms a shaft core 81a, a first flange 81b, and a second flange 81c, and is provided with a rotation mechanism (not shown). The shaft core 81a is formed in a cylindrical shape having a through hole penetrating along the advancing direction X inside.

[0126] The first flange 81b is provided with 18 fourth-bobbin mounting portions 812, and the second flange 81c is formed with 18 insertion holes 813. These fourth bobbin mounting portions 812 and insertion holes 813 are arranged at positions facing each other so as to be substantially regular hexagons when viewed from the advancing direction X, and two fourth bobbin mounting portions 812 and insertion holes 813 are provided at equal intervals between the respective vertices.

[0127] The rotation mechanism provided in the fourth layer twisting member 81 has the same configuration as the rotation mechanism provided in the second layer twisting member 52 described above, and is provided on the axis 81a. Note that the rotation mechanism is not limited to being provided only on the axis 81a, similar to the rotation mechanism provided in the second layer twisting member 52.

[0128] The fourth layer gathering chuck 82 is formed in a cylindrical shape having an inner diameter equivalent to the outer diameter of the fourth layer 14, that is, the diameter of the aluminum conductor 10, and gathers the 18 aluminum-based core wires 20 that have passed through the insertion holes 813 around the inner layer portion 111 that has passed through the through holes.

[0129] A method for manufacturing the aluminum conductor 10 using the stranding machine 4c configured as described above will be described below. As shown in FIG. 12, the aluminum conductor 10 is manufactured by performing a softening treatment step (step U1) and then a twisting step (step U2).

[0130] The softening treatment step (step U1) in the method for manufacturing the aluminum conductor 10 is the same as the softening treatment step (step S1) in the method for manufacturing the aluminum conductor 10A described above, and thus the description thereof is omitted.

[0131] In the twisting step (step U2), first, bobbins 3a around which the softened aluminum-based core wires 20 are wound are respectively attached to the first bobbin mounting portion 51, the second bobbin mounting portion 522, the third bobbin mounting portion 612, and the fourth bobbin mounting portion 812.

[0132] The tips of the aluminum-based core wires 20 unwound from the bobbins 3a attached to the respective bobbin mounting portions are fixed to the bobbin 3b attached to the conductor winding portion 7 in a bundled state after passing through a predetermined location. When the fixing of the aluminum core wire 20 to the bobbin 3b is completed, while revolving the second layer twisting member 52, the third layer twisting member 61, and the fourth layer twisting member 81 in the same direction, the first bobbin mounting portion 51, the second bobbin mounting portion 522, the third bobbin mounting portion 612, the fourth bobbin mounting portion 812, and the conductor winding portion 7 are rotated.

[0133] At this time, according to the rotation speed of the conductor winding portion 7, the rotation speeds of the first bobbin mounting portion 51, the second bobbin mounting portion 522, the third bobbin mounting portion 612, and the fourth bobbin mounting portion 812 are controlled so that a tension of 10.6 N acts on each of the aluminum core wires 20 to be twisted. Note that the tension applied to the aluminum core wire 20 is not limited to 10.6 N only, and can be appropriately set within the range of 5.3 N or more and 23.85 N or less, preferably 7.95 or more and 13.25 N or less (the tension per unit cross-sectional area is 12.5 N / mm 2 or more and 56.3 N / mm 2 or less, preferably 18.8 N / mm 2 or more and 31.3 N / mm 2 or less).

[0134] Furthermore, according to the rotation speed of the conductor winding portion 7, the revolution speeds of the second layer twisting member 52, the third layer twisting member 61, and the fourth layer twisting member 81 are controlled so that the aluminum core wire 20 is twisted at a twisting pitch of 31.7 mm, which is about 8.7 times the outer diameter Φa of the conductor. In this embodiment, by making the revolution speeds of the second layer twisting member 52, the third layer twisting member 61, and the fourth layer twisting member 81 the same, the twisting pitches of the second to fourth layers can be made the same twisting pitch.

[0135] The twisting process (step U2) as described above is performed until the aluminum conductor 10 reaches the desired length. Finally, a coating step (step S3) is performed to coat the outer periphery of the aluminum conductor 10 manufactured in the twisting step (step U2) with the insulating resin coating 30, thereby manufacturing the aluminum electric wire 1. Note that since the coating step (step S3) is the same as the coating step (step S3) in the manufacturing method of the aluminum conductor 10A described above, the description thereof is omitted.

[0136] As described above, one aluminum-based core wire 20 made of an aluminum-based material of the core 11 and 6, 12, and 18 aluminum-based core wires 20 are concentrically arranged and twisted in order from the core 11, and are composed of the softened aluminum-based core wires 20. By setting the twisting pitch to about 8.7 times which is 6.2 times or more and 15.7 times or less of the outer diameter Φa of the conductor, it is possible to configure a desired aluminum conductor 10 that suppresses problems such as twisting disorder of the aluminum-based core wires 20 and protrusion of the aluminum-based core wires 20 to the outside.

[0137] Note that since the twisting pitch of the aluminum conductor 10 is 8.7 times or more and 14.8 times or less of the outer diameter Φa of the conductor, it is possible to configure a desired aluminum conductor 10 that surely prevents problems such as twisting disorder of the aluminum-based core wires 20 and protrusion of the aluminum-based core wires 20.

[0138] In the above embodiment, the fourth layer 14 is continuously twisted with respect to the inner layer portion 111. However, for example, after twisting the inner layer portion 111 once, the fourth layer 14 may be twisted with respect to the inner layer portion 111.

[0139] In this case, the tension per unit cross-sectional area that applies tension to the inner layer portion 111 is 250.0 N / mm 2 or more and 1875.0 N / mm 2 or less.

[0140] In the twisting step, the tension applied to the aluminum-based core wire 20 is 5.3 N or more and 23.85 N or less, preferably 7.95 N or more and 13.25 N or less (the tension per unit cross-sectional area is 12.5 N / mm 2 or more and 56.3 N / mm 2、By applying a tension of 10.6 N, which is preferably 18.8 N or more and 31.3 N or less, the aluminum core wires 20 can be twisted together without slack at a predetermined twisting pitch, thereby preventing problems such as twisting disorder of the aluminum core wires 20 and protrusion of the aluminum core wires 20 to the outside, and manufacturing a desired aluminum conductor 10.

[0141] Thereby, in addition to the above effects, the tension applied to the inner layer portion 111 is such that the tension per unit cross-sectional area is 250.0 N / mm 2 or more and 1875.0 N / mm 2 or less. Even when the fourth layer 14 is twisted with 18 aluminum core wires 20 outside the inner layer portion 111 composed of 19 aluminum core wires 20, the aluminum core wires 20 constituting the fourth layer 14 can be twisted together without slack at a predetermined twisting pitch, thereby preventing problems such as twisting disorder of the aluminum core wires 20 and protrusion of the aluminum core wires 20 to the outside, and constructing a desired aluminum conductor 10.

[0142] Specifically, if a tension smaller than 250 N / mm 2 is applied to the inner layer portion 111 or the inner layer portion 111 is twisted without applying tension, there is a risk of slack occurring in the inner layer portion 111. On the other hand, if a tension larger than 1875.0 N / mm 2 is applied to the inner layer portion 111 for twisting, the aluminum core wires 20 constituting the inner layer portion 111 may stretch or break.

[0143] In the above example, the manufacturing of the aluminum electric wire 1 with a size of 8 sq is described. However, for example, for the aluminum electric wire 1 with a size of 2.5 sq or more and 16 sq or less, by appropriately adjusting the tension applied per unit cross-sectional area during manufacturing within the range of 12.5 N / mm 2 or more and 56.3 N / mm 2 or less per unit cross-sectional area, an aluminum electric wire 1A corresponding to each size can be manufactured.

[0144] In addition, when the aluminum core wires 20 and 20A are twisted together using the twisting machines 4b and 4a as described above to manufacture the aluminum conductors 10 and 10A, it is not necessary to perform the twisting process twice as in the conventional rope twisting method. This can simplify the equipment and the manufacturing process, improve the quality, and reduce the manufacturing cost.

[0145] In the above method, the tension is appropriately changed, and the composition of the aluminum wire 1 manufactured including the above-mentioned sizes is shown in Table 1.

[0146]

Table 1

[0147]

Table 2

[0148]

Table 3

[0149]

Table 4

[0150] First, the aluminum wires 1 and 1A (see Table 1 and Table 2) are compared with the conventionally used collectively twisted aluminum wire (see Table 4). For example, the aluminum wire 1 with a cross-sectional area of 5 sq and the stranded aluminum wire have the same outer conductor diameter of 2.80 mm. However, the eccentricity of the aluminum wires 1 and 1A is 76% and 75% respectively, while the eccentricity of the stranded aluminum wire is 45%.

[0151] In the case of the 5 sq stranded aluminum wire, since the eccentricity is smaller compared to the aluminum wire 1, it is necessary to increase the thickness of the insulating resin coating 30 to sufficiently protect the aluminum conductor (wall thickness 0.80 mm). Therefore, the finished outer diameter of the 5 sq stranded aluminum wire is 4.40 mm, which is larger than the finished outer diameter (3.60 mm) of the aluminum wire 1.

[0152] On the other hand, since the aluminum wire 1 can have a larger eccentricity, the thickness of the insulating resin coating 30 can be reduced. As a result, an aluminum wire with a smaller finished outer diameter compared to the conventional stranded aluminum wire can be manufactured.

[0153] Also, compare the aluminum wire 1 with a size of 5 sq (see Table 1) and the copper wire with a size of 3 sq (see Table 3). Both the 5 sq aluminum wire 1 and the 3 sq conductor are configured to have the same finished outer diameter of 3.60 mm. Moreover, the electrical resistance value of the 5 sq aluminum wire 1 is 6.76 mΩ / m, while the electrical resistance value of the 3 sq copper wire is 5.59 mΩ / m.

[0154] In addition, when comparing the aluminum wire 1 with a size of 16 sq (see Table 1) and the copper wire with a size of 10 sq (see Table 3), the finished outer diameters of the 16 sq aluminum wire 1 and the 10 sq copper wire are approximately 6.5 mm, and the electrical resistance values are 1.91 mΩ / m and 1.84 mΩ / m respectively.

[0155] In this way, the aluminum wire 1 can be manufactured to have the same finished outer diameter as the copper wire, and the difference between the electrical resistance value of the aluminum wire 1 and the electrical resistance value of the corresponding copper wire can be made within about 20%. Therefore, the above-mentioned aluminum wire 1 can be practically used instead of the copper wire.

[0156] In addition, the aluminum electric wire 1, 1A with a size of 8 sq has a mass per unit of approximately 30 g / m, while the corresponding copper wire of 5 sq has a mass of 58.2 g / m. Therefore, by using an aluminum electric wire, weight reduction can be achieved.

[0157] As described above, the aluminum electric wires 1, 1A shown in Table 1 and Table 2 are formed by coating an aluminum conductor 10, 10A composed of 37 or 19 aluminum-based core wires 20, 20A with 99% by mass or more of aluminum with an insulating resin coating 30. The aluminum-based core wires 20, 20A are concentrically twisted at the same pitch in a non-compressed state to form the aluminum conductor 10, 10A. Since the eccentricity of the insulating resin coating 30 is 70% or more, it is possible to form an aluminum electric wire 1, 1A that has the same conductivity as a copper electric wire 100 having a copper conductor 110 made of copper and does not have a large outer diameter of the electric wire.

[0158] Specifically, in the aluminum electric wire 1, 1A in which the aluminum conductor 10, 10A composed of 37 or 19 aluminum-based core wires 20, 20A is coated with an insulating resin coating 30, by concentrically twisting the aluminum-based core wires 20, 20A at the same pitch in a non-compressed state to form the aluminum conductor 10, 10A, it is possible to form an aluminum conductor 10, 10A in which the aluminum-based core wires 20, 20A, which are excellent in flexibility and lightweight, are arranged in an orderly manner in the cross-section without being scattered.

[0159] Specifically, although the outer diameter of the electric wire does not increase because the aluminum conductor 10, 10A is coated with an insulating resin coating 30 that is thin in thickness with respect to the outer diameter of the conductor of the aluminum conductor 10, 10A, for example, as in the case of a stranded conductor in which the core wires are stranded in a stranding method such as bunch stranding or rope stranding, there is a risk that the scattered core wires may bite into the insulating resin coating, or the insulating resin coating may be eccentric, resulting in a locally thin insulating resin coating, and the required performance of the insulating resin coating 30 such as insulation and strength may not be ensured.

[0160] On the other hand, as described above, since the aluminum conductors 10 and 10A, which are formed by concentrically twisting the aluminum core wires 20 and 20A in a non-compressed state and at the same pitch, are orderly arranged in cross-section, even a thin insulating resin coating 30 can surely ensure the required thickness.

[0161] Also, by configuring the aluminum conductors 10 and 10A with 19 or 37 concentrically twisted aluminum core wires 20 and 20A, aluminum electric wires 1 and 1A provided with conductors configured in a twisting manner according to a desired cross-sectional area can be formed. Further, since the 19 or 37 aluminum core wires constituting the aluminum conductors 10 and 10A are concentrically twisted, the conductivity between the aluminum core wires can also be ensured.

[0162] Note that by setting the aluminum core wires 20 and 20A in a non-compressed state, the bending performance of the aluminum conductors 10 and 10A can be ensured. Specifically, when the aluminum core wires 20 and 20A are compressed, the rigidity of the aluminum conductors 10 and 10A increases and the desired bending performance cannot be obtained, but by setting the aluminum core wires 20 and 20A in a non-compressed state, the bending performance can be ensured.

[0163] Furthermore, by configuring the aluminum conductors 10 and 10A with the aluminum core wires 20 and 20A, the mass of the aluminum electric wires 1 and 1A can be reduced. Specifically, since the aluminum core wires 20 constituting the aluminum electric wires 1 and 1A have a lower specific gravity than the copper core wires 120 constituting the copper conductor 110, even if the total cross-sectional area of the aluminum core wires 20 and 20A is large, the mass of the aluminum electric wires 1 and 1A can be reduced (see Table 1, Table 2, and Table 3).

[0164] Furthermore, since the aluminum electric wires 1 and 1A have an eccentricity of 70% or more, that is, since the aluminum electric wires 1 and 1A have no variation in the thickness of the insulating resin coating 30, even for aluminum electric wires 1 and 1A having a desired outer diameter, the aluminum conductors 10 and 10A can surely be protected by the insulating resin coating 30, and the cross-sectional shape of the aluminum electric wires 1 and 1A can be made close to a perfect circle.

[0165] Further, by arranging the aluminum-based core wires 20, 20A that constitute the aluminum conductors 10, 10A in a regular hexagonal cross-sectional shape, the aluminum-based core wires 20, 20A that constitute the aluminum conductors 10, 10A can be arranged in an orderly manner in the cross-section, and the cross-sectional shape of the aluminum conductors 10, 10A can be stabilized over the longitudinal direction. Therefore, the thickness of the insulating resin coating 30 can be made substantially the same on average, and even if the insulating resin coating 30 is thin, the required thickness can be surely ensured.

[0166] As another aspect of the present invention, by making the core wire diameters of the 19 or 37 aluminum-based core wires 20, 20A that constitute the aluminum conductors 10, 10A the same diameter, the aluminum conductors 10, 10A can be formed by one aluminum-based core wire 20, 20A. Therefore, the error in the inner diameter of the aluminum conductors 10, 10A can be reduced. Furthermore, since it is not necessary to manufacture a plurality of types of aluminum-based core wires 20, 20A, the manufacturing process can be simplified and the manufacturing cost can be reduced.

[0167] Furthermore, since the aluminum-based core wires 20, 20A that constitute the aluminum-based core wires are arranged in a regular hexagonal cross-sectional shape, the aluminum-based core wires 20, 20A arranged in the outer layer can be fitted between the aluminum-based core wires 20, 20A arranged in the inner layer. Therefore, they can be arranged more stably. That is, the aluminum conductors 10, 10A can be arranged more orderly. Furthermore, by performing concentric stranding at the same pitch, the aluminum-based core wires 20, 20A can be prevented from coming apart.

[0168] As an aspect of the present invention, when the cross-sectional area of the aluminum conductors 10, 10A is made 2.5 mm 2 or more and less than 17 mm 2 an aluminum electric wire 1, 1A having a desired conductivity and not increasing the outer diameter of the electric wire can be constituted.

[0169] Specifically, since the aluminum-based core wires 20, 20A have lower conductivity than copper-based core wires of the same diameter, the cross-sectional area of the aluminum conductors 10, 10A composed of 37 or 19 aluminum-based core wires 20, 20A is 2.5 mm2 When it is less than that, when the outer diameter is made the same as that of a copper wire composed of a copper core wire, it becomes difficult to ensure the same level of conductivity.

[0170] Conversely, when the cross-sectional area of the aluminum conductors 10, 10A composed of 37 or 19 aluminum core wires 20, 20A is 17 mm 2 When it is 17 mm² or more, although the same level of conductivity as that of a copper wire can be ensured, the rigidity of the aluminum conductors 10, 10A increases, resulting in a loss of flexibility. For example, the bending performance of the wire evaluated in a flexibility test or the like may decrease.

[0171] Also, by making the insulating resin coating 30 have a thickness of 10% or more and 20% or less of the outer diameters Φa, Φb of the conductors, an aluminum wire 1, 1A with a large wire outer diameter can be configured. For example, when the thickness of the insulating resin coating 30 is less than 10%, there is a possibility that the required performance required for the insulating resin coating 30 such as insulation and strength cannot be satisfied.

[0172] Conversely, when the thickness of the insulating resin coating 30 is greater than 20% with respect to the outer diameter of the conductor, there is a possibility that the wire outer diameter becomes larger than that of a copper wire having the same level of conductivity. On the other hand, since the insulating resin coating 30 has a thickness of 10% or more and 20% or less of the outer diameter of the conductor, an aluminum wire 1, 1A having a desired conductivity and not having a large wire outer diameter can be configured.

[0173] Furthermore, the aluminum conductors 10, 10A composed of 37 or 19 aluminum core wires 20, 20A have a larger outer diameter of the conductor of the aluminum conductors 10, 10A than that of the copper conductor 110 composed of a copper core wire 120 having the same level of conductivity. However, since the aluminum core wires 20, 20A are made of a flexible aluminum-based material containing 99% by mass or more of aluminum, the aluminum core wires themselves have appropriate flexibility, and an aluminum wire 1, 1A having appropriate flexibility can be configured.

[0174] Also, when the aluminum electric wires 1 and 1A are crimp-connected, for example, at the crimping portion of the crimp terminal, they can be properly crimped and connected at a crimping rate of, for example, about 40 to 80% (more preferably 40 to 70%) without damaging the crimping portion. Specifically, when the aluminum conductors 10 and 10A are formed by twisting aluminum-based core wires with less than 99% by mass of aluminum, since the hardness of the aluminum-based core wires increases, if the aluminum conductors formed of the aluminum-based core wires are crimped at a predetermined crimping rate, the crimping portion of the crimp terminal may be damaged. However, by using the aluminum conductors 10 and 10A formed of the aluminum-based core wires 20 and 20A with 99% by mass or more of aluminum having low hardness, the crimping portion of the crimp terminal can be properly crimped and connected without being damaged.

[0175] Also, by setting the thickness of the insulating resin coating 30 to be 7% or more and less than 14% of the outer diameter of the electric wire, an aluminum electric wire 1 or 1A can be configured that can ensure the minimum wall thickness of the insulating resin coating 30. Also, since the insulating resin coating 30 has a tensile strength of 19 MPa or more, a heat distortion rate of 25% or less, a cold resistance of -20°C or less, and a volume resistivity of 3×10 12 Ω·cm or more at a temperature of 23°C, an aluminum electric wire 1 or 1A can be configured that has a desired conductivity, does not increase the outer diameter of the electric wire, and satisfies the required performance of the insulating resin coating 30 without reducing the mechanical strength as the insulating resin coating 30.

[0176] Also, by setting the cross-sectional area of the aluminum conductors 10 and 10A to be 5 mm 2 or more and setting the thickness of the insulating resin coating 30 to be 15% or less of the outer diameter of the conductor of the aluminum conductors 10 and 10A, an aluminum electric wire 1 or 1A can be configured that has the same conductivity as a copper electric wire 100 having a copper conductor 110 made of copper by the aluminum conductors 10 and 10A formed of concentrically twisted aluminum-based core wires 20 and 20A, can surely ensure the required thickness even with a thin insulating resin coating 30, has the same conductivity as the copper electric wire 100 having the copper conductor 110 made of copper, and does not increase the outer diameter of the electric wire.

[0177] Also, an aluminum conductor 10 is formed by concentrically twisting 37 aluminum-based core wires 20, or an aluminum conductor 10A is formed by 19 aluminum-based core wires 20A, thereby forming aluminum electric wires 1 and 1A provided with aluminum conductors 10 and 10A configured in a twisting manner according to a desired cross-sectional area.

[0178] In the correspondence between the configuration of this invention and the above-described embodiment, the conductor of this invention corresponds to the aluminum conductors 10 and 10A. However, this invention is not limited only to the configuration of the above-described embodiment, and many embodiments can be obtained.

Explanation of Reference Numerals

[0179] 1, 1A... Aluminum electric wire 10, 10A... Aluminum conductor 20, 20A... Aluminum-based core wire 30... Insulating resin coating

Claims

1. An aluminum electric wire in which a conductor composed of a plurality of aluminum-based core wires with 99% by mass or more of aluminum is coated with an insulating resin coating, The conductor is formed by concentrically twisting 19 or 37 of the aluminum-based core wires in a non-compressed state and at the same pitch, When the conductor is composed of 19 of the aluminum-based core wires, the outer diameter of the aluminum-based core wire is 0.56 mm or more and 1.06 mm or less, When the conductor is composed of 37 of the aluminum-based core wires, the outer diameter of the aluminum-based core wire is 0.40 mm or more and 0.76 mm or less, The cross-sectional area of the conductor is 5 mm ２ or more and 17 mm ２ less than, The eccentricity of the insulating resin coating is 70% or more, The insulating resin coating has a thickness of 10% or more and 20% or less of the outer diameter of the conductor Aluminum electric wire.

2. The core wire diameters of the 19 or 37 aluminum-based core wires constituting the conductor are the same The aluminum electric wire according to claim 1.

3. The insulating resin coating is a vinyl chloride resin The aluminum electric wire according to claim 1 or claim 2.

4. A method for manufacturing an aluminum electric wire in which a conductor formed by twisting together one aluminum-based core wire with 99% by mass or more of aluminum disposed at the center and 6, 12, and 18 of the aluminum-based core wires disposed concentrically from the center is coated with an insulating resin coating, The outer diameter of the aluminum-based core wire is 0.40 mm or more and 0.76 mm or less, The aluminum-based core wires are disposed concentrically from the center to form the conductor, and the tension per unit cross-sectional area is 12.5 N / mm ２ or more and 56.3 N / mm ２Applying the following tension to the aluminum-based core wire to twist the aluminum-based core wire to form the conductor in a twisting step, and a coating step of coating the formed conductor with the insulating resin coating in this order, wherein the cross-sectional area of the conductor is 5 mm ２ or more and 17 mm ２ less than, and the insulating resin coating has a thickness of 10% or more and 20% or less of the outer diameter of the conductor A method for manufacturing an aluminum electric wire.

5. Before the twisting step, A softening treatment step of performing a softening treatment on the aluminum-based core wire is performed The method for manufacturing an aluminum electric wire according to claim 4.

6. A method for manufacturing an aluminum electric wire in which a conductor formed by twisting one aluminum-based core wire having 99% by mass or more of aluminum disposed at the center and a predetermined number of the aluminum-based core wires disposed concentrically from the center is coated with an insulating resin coating, the outer diameter of the aluminum-based core wire is 0.56 mm or more and 1.06 mm or less, a twisting step of twisting six and twelve of the aluminum-based core wires disposed concentrically from the center to form the conductor, and a coating step of coating the formed conductor with the insulating resin coating in this order, In the twisting step, a tension of 12.5 N / mm per unit cross-sectional area is applied to the aluminum-based core wire ２ or more and 87.5 N / mm ２ or less, the cross-sectional area of the conductor is 5 mm ２ or more and 17 mm ２ less than, and the insulating resin coating has a thickness of 10% or more and 20% or less of the outer diameter of the conductor A method for manufacturing an aluminum electric wire.

7. In the twisting step, Apply a tension of 62.5 N / mm or more and 87.5 N / mm or less per unit cross-sectional area to the aluminum-based core wire, ２ and ２ perform a softening treatment step of subjecting the conductor to a softening treatment after the twisting step and before the coating step. The method for manufacturing an aluminum electric wire according to claim 6.

8. Before the twisting step, perform a softening treatment step of subjecting the aluminum-based core wire to a softening treatment, and in the twisting step, apply a tension of 12.5 N / mm or more and 56.3 N / mm or less per unit cross-sectional area to the aluminum-based core wire. ２ and ２ The method for manufacturing an aluminum electric wire according to claim 6.

9. A method for manufacturing an aluminum electric wire in which a conductor formed by twisting one aluminum-based core wire having 99% by mass or more of aluminum disposed at the center and a predetermined number of the aluminum-based core wires disposed concentrically from the center is coated with an insulating resin coating, wherein the outer diameter of the aluminum-based core wire is 0.40 mm or more and 0.76 mm or less, an inner layer twisting step of twisting six and twelve of the aluminum-based core wires disposed concentrically from the center to form an inner layer portion, and an outer layer twisting step of twisting an outermost layer with eighteen of the aluminum-based core wires disposed concentrically outside the inner layer portion to form the conductor, are performed in this order, a coating step of coating the formed conductor with the insulating resin coating is performed in this order, in the inner layer twisting step, apply a tension of 12.5 N / mm or more and 87.5 N / mm or less per unit cross-sectional area to the aluminum-based core wire, and ２ in the outer layer twisting step, ２ apply a tension of 12.5 N / mm or more and 87.5 N / mm or less per unit cross-sectional area to the aluminum-based core wire. and Set the outer layer twisting pitch for twisting the outermost layer to be the same pitch as the twisting pitch of the inner layer part. Apply a tension of 12.5 N / mm or more and 56.3 N / mm or less per unit cross-sectional area to the aluminum-based core wire, and apply a tension of 250.0 N / mm or more and 1875.0 N / mm or less per unit cross-sectional area to the inner layer part. ２ 56.3 N / mm ２ Apply a tension of 12.5 N / mm or more and 56.3 N / mm or less per unit cross-sectional area to the aluminum-based core wire, and apply a tension of 250.0 N / mm or more and 1875.0 N / mm or less per unit cross-sectional area to the inner layer part. ２ 1875.0 N / mm ２ Apply a tension of 250.0 N / mm or more and 1875.0 N / mm or less per unit cross-sectional area to the inner layer part. The cross-sectional area of the conductor is 5 mm or more and less than 17 mm. ２ 17 mm ２ The cross-sectional area of the conductor is 5 mm or more and less than 17 mm. The insulating resin coating has a thickness of 10% or more and 20% or less of the outer diameter of the conductor. A method for manufacturing an aluminum electric wire.

10. Before the coating process and after the twisting process, perform a softening treatment process for subjecting the conductor to a softening treatment. A method for manufacturing an aluminum electric wire according to any one of Claims 4, 5, 8, and 9.

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