JP2016046522A - Wiring material for coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring material for a coil, which enables the reduction in the conductor loss caused by an alternating magnetic field from outside.SOLUTION: A wiring material 10 for a coil comprises: a conductor 11 having at least one metal selected from copper, a copper alloy, aluminum and an aluminum alloy, of which the cross section is 0.4 mmor larger; and a magnetic material layer 12 having an iron-based material including Fe, and formed on the periphery of the conductor 11. The percentage of the cross section of the magnetic material layer 12 to the total cross section of the conductor 11 and the magnetic material layer 12 is 3-40%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coil wire. In particular, the present invention relates to a coil wire material that can reduce conductor loss caused by an alternating magnetic field from the outside.

  Coils are used in various electric devices. Examples of the electric device including the coil include a motor, a reactor, a transformer (transformer), an IH heater (induction heating device), and the like.

  Generally, a coil is formed by winding a coil wire (winding) having an electric conductor (conductive wire) in a spiral shape. For example, in Patent Document 1, a wire having a coating layer on the outer surface of a copper wire is used as a core, an adhesion layer is formed on the outer surface of the coating layer, and an insulating layer is further formed on the adhesion layer. An insulated wire is described. Patent Document 1 describes using, for example, a nickel-plated copper wire as a core material.

Japanese Patent Application Laid-Open No. 07-296643

  From the viewpoint of reducing AC loss of electrical equipment, it is desired to develop a coil wire that can reduce conductor loss due to an alternating magnetic field (fluctuating magnetic field) from the outside.

  In recent years, with the increase in performance and efficiency of various electrical devices (eg, motors), the increase in current has progressed. The diameter is increased (the cross-sectional area is increased). When an alternating current is applied to a coil, the magnetic flux of an alternating magnetic field (variable magnetic field) generated from one coil wire by the alternating current is linked to the other coil wire at a location where the coil wires are close to each other. As a result, an eddy current may be generated in the conductor of the other coil wire, resulting in an eddy current loss. In addition, eddy current loss may occur in the conductor of the coil wire due to leakage magnetic flux from the magnetic core on which the coil is disposed. When the alternating magnetic field generated with the increase in current increases, the eddy current loss generated in the conductor of the coil wire (coil) increases, and the increase in AC loss in the electrical equipment becomes significant.

  Therefore, one of the objects of the present invention is to provide a coil wire that can reduce the loss of a conductor generated by an alternating magnetic field from the outside.

The coil wire according to one embodiment of the present invention includes at least one metal selected from copper, a copper alloy, aluminum, and an aluminum alloy, a conductor having a cross-sectional area of 0.4 mm ² or more, and Fe. And a magnetic layer formed on an outer periphery of the conductor, wherein a ratio of a cross-sectional area of the magnetic layer to a cross-sectional area of the conductor and the magnetic layer is 3% or more 40% or less.

  The said coil wire can reduce the loss which generate | occur | produces in a conductor by the alternating magnetic field from the outside.

It is a schematic sectional drawing which shows an example of a structure of the wire material for coils which concerns on embodiment. It is a schematic sectional drawing which shows another example (form by which the insulating layer was formed in the outer periphery of a magnetic body layer) of the structure of the wire material for coils which concerns on embodiment. It is a schematic sectional drawing which shows another example (form by which the insulating layer was formed between the conductor and the magnetic body layer) of the structure of the wire material for coils which concerns on embodiment. It is a schematic sectional drawing which shows another example (The form by which the insulating layer was formed between the conductor and the magnetic body layer, and the outer periphery of the magnetic body layer) of the structure of the coil wire which concerns on embodiment. It is a schematic sectional drawing which shows another example (The form by which the magnetic body layer, the insulating layer, the magnetic body layer, and the insulating layer were formed in order on the outer periphery of the conductor) of the structure of the coil wire which concerns on embodiment. It is a schematic sectional drawing which shows another example (The form by which the insulating layer, the magnetic body layer, the insulating layer, and the magnetic body layer were formed in order on the outer periphery of the conductor) of the structure of the coil wire which concerns on embodiment. It is a schematic sectional drawing which shows another example of the structure of the coil wire which concerns on embodiment (form which the magnetic body layer, the insulating layer, the magnetic body layer, the insulating layer, and the magnetic body layer were formed in order on the outer periphery of the conductor). . It is a schematic block diagram which shows the measurement circuit used for the measurement of the loss of the wire material for coils. It is a figure which shows the graph which plotted the relationship between Bsx (t / w) and the loss in the wire for coils of Example 1. FIG.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described.

(1) A wire for a coil according to an aspect of the present invention includes a conductor having at least one metal selected from copper, a copper alloy, aluminum, and an aluminum alloy, and having a cross-sectional area of 0.4 mm ² or more. A magnetic material layer including an iron-based material including Fe and formed on an outer periphery of the conductor, wherein a ratio of a cross-sectional area of the magnetic material layer to a cross-sectional area of the conductor and the magnetic material layer is 3% or more and 40% or less.

  The coil wire includes a magnetic layer on the outer periphery of the conductor, so that the magnetic flux of an alternating magnetic field from the outside flows through the magnetic layer, thereby reducing the magnetic flux linked to the conductor. That is, the magnetic layer functions as a magnetic shield that shields an external magnetic field to the conductor. Therefore, the eddy current generated in the conductor by the alternating magnetic field from the outside can be suppressed, and the eddy current loss generated in the conductor can be reduced. In particular, since the magnetic layer has an iron-based material containing Fe, the magnetic layer has a high relative magnetic permeability and saturation magnetic flux density, and magnetic flux tends to flow in the magnetic layer, so that it is likely to link to the conductor. Can effectively shield the magnetic flux. In addition, since the ratio of the cross-sectional area of the magnetic layer to the total cross-sectional area of the conductor and the magnetic layer is 3% or more, the cross-sectional area (magnetic path cross-sectional area) through which the magnetic flux flows can be secured in the magnetic layer. The magnetic flux can be sufficiently passed through the magnetic layer, and the magnetic flux linked to the conductor can be sufficiently reduced. On the other hand, when the ratio of the cross-sectional area of the magnetic layer is 40% or less, a necessary cross-sectional area of the conductor can be secured while suppressing an increase in the diameter of the coil wire. Furthermore, when the ratio of the cross-sectional area of the magnetic layer is 40% or less, a decrease in the bending workability of the coil wire due to the magnetic layer becoming too thick can be suppressed, so that the bending workability can be easily maintained. Accordingly, the coil wire has a high magnetic shielding effect in the magnetic layer, and can reduce loss generated in the conductor due to an alternating magnetic field from the outside.

In the coil wire, the conductor has copper or copper alloy, aluminum or aluminum alloy, and the cross-sectional area is 0.4 mm ² or more, so that the conductivity of the conductor is high and the electrical resistance of the conductor is reduced. it can. Therefore, a large current (for example, 2 A or more) can flow with low loss, and a sufficient current capacity can be secured.

  (2) As one form of the coil wire, when the saturation magnetic flux density of the magnetic layer is Bs, the maximum width of the coil wire is w, and the thickness of the magnetic layer is t, Bs × ( t / w) ≧ 0.01T.

  When Bs × (t / w) satisfies 0.01 T or more, a sufficient magnetic shielding effect against an alternating magnetic field from the outside can be obtained, and the loss generated in the conductor can be further reduced. The larger the value, the higher the effect of suppressing the conductor loss.

  (3) As one form of the said coil wire, it is mentioned that the average crystal grain diameter of the said conductor is 200 micrometers or less.

  The average crystal grain size of copper or copper alloy, aluminum or aluminum alloy constituting the conductor is 200 μm or less, so that the strength (yield stress and 0.2% proof stress) and elongation are further improved, and more excellent mechanical properties. Is obtained.

  (4) As one form of the said wire material for coils, it is mentioned that a yield stress is 60 Mpa or more and breaking elongation is 5% or more.

  When the yield stress is 60 MPa or more and the elongation at break is 5% or more, sag resistance is high, workability is excellent, and excellent mechanical properties are obtained.

  (5) As one form of the said wire material for coils, it is mentioned that the said iron-type material contains 0.5 mass% or more of Si, or contains 40 mass% or more of Co.

  An iron-based material containing 0.5% by mass or more of Si (for example, silicon steel) or an iron-based material containing 40% by mass or more of Co (for example, permendur) has a relatively large specific resistance and is generated in the magnetic layer itself. Eddy current can be reduced. Therefore, this wire for coil can reduce the loss resulting from the alternating magnetic field from the outside not only in a conductor but in the whole wire.

  (6) As one form of the said coil wire, the saturation magnetic flux density of the said magnetic body layer is 1.5 T or more, and the specific resistance of the said magnetic body layer is 20 microhm * cm or more.

  Since the saturation magnetic flux density of the magnetic layer is as high as 1.5 T or more, even if the magnetic flux concentrates and flows in the magnetic layer, magnetic saturation is difficult, and the magnetic flux that can be linked to the conductor can be effectively reduced. When the specific resistance is as large as 20 μΩ · cm or more, eddy currents generated in the magnetic layer itself can be reduced. Therefore, this coil wire can reduce the loss caused not only by the conductor but also by the alternating magnetic field from the outside of the entire wire.

[Details of the embodiment of the present invention]
Specific examples of the coil wire according to the embodiment of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to the claim are included.

<Composition of coil wire material>
FIG. 1 shows a cross section obtained by cutting a coil wire in a direction perpendicular to the axial direction of the wire. The coil wire 10 includes a conductor 11 and a magnetic layer 12 formed on the outer periphery of the conductor 11 so as to cover the conductor 11.

<conductor>
The conductor 11 is a portion through which a current mainly flows in the coil wire 10.

(composition)
The conductor 11 has at least one metal selected from copper, copper alloy, aluminum, and aluminum alloy. When the conductor 11 has copper or a copper alloy, or aluminum or an aluminum alloy, the conductivity of the conductor 11 can be increased. Therefore, the electrical resistance of the conductor 11 can be reduced, and the current can flow with low loss. From the viewpoint of reducing the loss, copper or a copper alloy is preferable, and from the viewpoint of reducing the weight, aluminum or an aluminum alloy is preferable.
The term “copper” as used herein refers to pure copper containing 99.9% by mass or more of Cu. Specifically, tough pitch copper, deoxidized copper (eg, phosphorus deoxidized copper), oxygen-free copper (OFC) Is mentioned.
“Aluminum” is pure aluminum containing 99 mass% or more of Al.
The “copper alloy” is a copper-based alloy containing 50% by mass or more, preferably 90% by mass or more of Cu, and containing an additive element other than Cu. Examples of the additive element of the copper alloy include Sn, Zr, Fe, Zn, Ag, Cr, P, Si, Mn, Ti, Mg, and Ni.
The “aluminum alloy” is an aluminum-based alloy containing 50% by mass or more, preferably 90% by mass or more of Al and containing an additive element other than Al. Examples of the additive element of the aluminum alloy include Si, Cu, Mg, Zn, Fe, Mn, Ni, Ti, Cr, Ca, Zr, and Li.
The content of the additive element is preferably set as appropriate according to the type of the additive element as long as desired conductivity is obtained. The total content of additive elements is, for example, from 0.1% by mass to 30% by mass, and preferably from 0.1% by mass to 5.0% by mass. From the viewpoint of increasing the electrical conductivity, it is preferable that the content of the additive element is small, and it is desirable to set the content to a minimum within a range where the necessary electrical conductivity can be obtained. When the content of the additive element is large, the strength and the like are excellent.
The conductivity of the conductor 11 is, for example, 70% IACS or more, preferably 80% IACS or more, more preferably 90% IACS or more.
The conductor 11 is preferably made of copper (pure copper) from the viewpoint of ensuring higher conductivity.

  It is preferable that the oxygen content and the hydrogen content of copper or copper alloy, aluminum or aluminum alloy constituting the conductor 11 are small. When the magnetic layer 12 is formed immediately above the outer periphery of the conductor 11 and the conductor 11 and the magnetic layer 12 are in direct contact, if the conductor 11 contains a large amount of oxygen or hydrogen, Oxygen and hydrogen may diffuse and the ductility and magnetic properties of the magnetic layer 12 may be impaired. The oxygen content of the conductor 11 is preferably, for example, 50 ppm or less and 10 ppm or less by mass ratio. The hydrogen content of the conductor 11 is preferably, for example, 10 ppm or less and 5 ppm or less by mass ratio. For example, the oxygen content is measured by infrared spectroscopy. For example, the hydrogen content is measured by an inert gas melting method. In addition, an inert gas melting-infrared absorption method and the like can be mentioned.

  In view of the above viewpoint, the conductor 11 is preferably made of oxygen-free copper having the highest purity and containing almost no impurities such as oxygen and hydrogen among pure copper.

(Cross sectional area)
The cross-sectional area of the conductor 11 is 0.4 mm ² or more. The electrical resistance of the conductor 11 can be made small because the cross-sectional area of the conductor 11 in the cross section of the coil wire 10 is 0.4 mm ² or more. Therefore, since the conductor 11 has copper or a copper alloy, or aluminum or an aluminum alloy and has a cross-sectional area of 0.4 mm ² or more, a large current (for example, 2 A or more) flows with low loss. And a sufficient current capacity can be secured. A preferable cross-sectional area of the conductor 11 is, for example, 0.5 mm ² or more, more preferably 0.8 mm ² or more. The upper limit of the cross-sectional area of the conductor 11 is not particularly limited, but the cross-sectional area of the conductor 11 is preferably, for example, 50 mm ² or less from the viewpoint of avoiding an excessive increase in the diameter of the conductor 11 (coil wire 10).

(shape)
The shape of the conductor 11 is not particularly limited. As the cross-sectional shape of the conductor 11 in the cross-section of the coil wire 10, various shapes such as a circular shape, an elliptical shape, a race track shape, a polygonal shape such as a hexagonal shape, a triangular shape, and a rectangular shape can be adopted. Typically, the cross-sectional shape of the conductor 11 and the cross-sectional shape of the coil wire 10 are similar.

(Crystal grain size)
It is preferable that the conductor 11 has a fine crystal structure because of excellent mechanical characteristics. For example, the average crystal grain size of the conductor 11 is preferably 200 μm or less. When the average crystal grain size of copper or copper alloy, aluminum or aluminum alloy constituting the conductor 11 is 200 μm or less, the strength (yield stress and 0.2% proof stress) and elongation are further improved, and more excellent mechanical properties. Characteristics are obtained. The “average crystal grain size of the conductor 11” as used herein is an average crystal grain size measured in accordance with the cutting method described in “Test method for grain size of rolled copper products” defined in JIS H 0501 (1986). . The average crystal grain size is measured by observing the crystal structure of the cross section of the conductor 11 in the cross section of the coil wire 10 with a microscope. A more preferable average crystal grain size of the conductor 11 is, for example, 100 μm or less, and further 50 μm or less. The lower limit of the average crystal grain size of the conductor 11 is not particularly limited, but from the viewpoint of manufacturing, the average crystal grain size of the conductor 11 is, for example, 1 μm or more.

<Magnetic layer>
The magnetic layer 12 mainly functions as a magnetic shield that shields an external magnetic field to the conductor 11. Specifically, the magnetic layer 12 has an effect of reducing the magnetic flux linked to the conductor 11 by flowing a magnetic flux due to the alternating magnetic field when an alternating magnetic field is applied to the coil wire 10 from the outside.

(composition)
The magnetic layer 12 has an iron-based material containing Fe. When the magnetic layer 12 includes an iron-based material containing Fe, the relative permeability and saturation magnetic flux density of the magnetic layer 12 can be increased. As a result, the magnetic flux of the alternating magnetic field tends to concentrate on the magnetic layer 12 and flow, so that the magnetic flux to be linked to the conductor 11 can be effectively shielded. Some iron-based materials have a high specific resistance depending on the additive element and the like, and since the electric resistance of the magnetic layer 12 is high, eddy currents generated in the magnetic layer 12 itself can be reduced. As a result, since the eddy current loss of the magnetic layer 12 can be reduced, the loss of the entire coil wire 10 in addition to the conductor 11 can be reduced.
The “iron-based material containing Fe” here refers to a metal or a compound containing Fe, and specifically, at least one soft magnet selected from iron, an iron-based alloy, and an iron-based compound. Materials.
Here, what contains 99.8 mass% or more of Fe is called "iron." Specific examples of iron-based alloys include carbon steel (Fe-C alloy), permalloy (Fe-Ni alloy), silicon steel (Fe-Si alloy), permendur (Fe-Co alloy), and iron-based amorphous alloy. , Sendust (Fe-Si-Al alloy) and the like. Specific examples of the iron-based compound include iron oxide (iron oxide) such as ferrite (Fe ₂ O ₃ ), FeO, and Fe ₃ O ₄ .

  Examples of the iron-based material having a large specific resistance include those having a Si content of 0.5% by mass or more, specifically silicon steel, iron-based amorphous alloy, super tough steel, and the like. As the Si content increases, the specific resistance tends to increase. For example, 1.0 mass% or more, 1.5 mass% or more, or 2.0 mass% or more of an iron-based material can be obtained. The magnetic layer 12 composed of such an iron-based material can satisfy, for example, a specific resistance of 15 μΩ · cm or more, and further 20 μΩ · cm or more. If the Si content is too large, the workability is lowered, so that it is preferably 10% by mass or less, more preferably 8% by mass or less.

  Alternatively, examples of the iron-based material having a large specific resistance include those having a Co content of 40% by mass or more, specifically, permendur. Since the saturation magnetic flux density is maximized when the Co content is around 65% by mass, an iron-based material having a Co content of 45% by mass or more, more preferably 50% by mass or more, and 60% by mass or more can be obtained. The magnetic layer 12 made of such an iron-based material can satisfy, for example, a specific resistance of 20 μΩ · cm or more. If the Co content is too large, the saturation magnetic flux density is lowered, so that it is preferably less than 80% by mass, and more preferably 70% by mass or less.

  It is preferable that the oxygen content and the hydrogen content of the iron-based material constituting the magnetic layer 12 are also small. If the content of oxygen or hydrogen is too large, the ductility and magnetic characteristics of the magnetic layer 12 are impaired as described above, and a tape made of an iron-based material is used for forming the magnetic layer 12 as described later. This is because blow holes and other welding defects may occur when welding is performed using a material. The oxygen content of the iron-based material constituting the magnetic layer 12 is preferably, for example, 50 ppm or less and 10 ppm or less by mass ratio. The hydrogen content of the iron-based material constituting the magnetic layer 12 is preferably, for example, 10 ppm or less and 5 ppm or less by mass ratio. As a method for measuring the oxygen content and the hydrogen content, the method described for the conductor 11 can be used.

(Cross sectional area)
The ratio of the cross-sectional area of the magnetic layer 12 (total when there are a plurality of layers described later) to the total cross-sectional area of the conductor 11 and the magnetic layer 12 (hereinafter sometimes referred to as “area ratio”) is 3 % To 40%. The ratio of the area occupied by the magnetic layer 12 in the transverse cross section of the coil wire 10 is 3% or more and 40% or less, so that the large diameter of the coil wire 10 is ensured while ensuring the magnetic path cross-sectional area in the magnetic layer 12. Can be suppressed. Specifically, when the area ratio of the magnetic layer 12 is 3% or more, the magnetic saturation of the magnetic layer 12 can be suppressed by ensuring a sufficient magnetic path cross-sectional area. Therefore, the magnetic flux can be sufficiently passed through the magnetic layer 12, and the magnetic flux linked to the conductor 11 can be sufficiently reduced. On the other hand, when the area ratio of the magnetic layer 12 is 40% or less, an increase in the diameter of the coil wire 10 can be suppressed. Further, excessively thickening the magnetic layer 12 causes a decrease in bending workability and elongation of the coil wire 10, and an increase in loss due to eddy current loss generated in the magnetic layer 12. There is a risk of doing. By setting the area ratio of the magnetic layer 12 to 40% or less, it is easy to maintain the bending workability by suppressing the deterioration of the bending workability of the coil wire 10, and the eddy current loss generated in the magnetic layer 12. It can be expected to suppress an increase in loss due to. A preferable area ratio of the magnetic layer 12 is, for example, 5% or more, and more preferably 10% or more and 20% or less. The thickness of the magnetic layer 12 is, for example, more than 10 μm and not more than 300 μm, preferably not less than 30 μm and not more than 200 μm.

(Magnetic characteristics)
The saturation magnetic flux density of the magnetic layer 12 is preferably 0.5 T or more, for example. The higher the saturation magnetic flux density, the more easily the magnetic saturation of the magnetic layer 12 can be suppressed and the magnetic shielding effect of the magnetic layer 12 can be enhanced, so that the magnetic flux linked to the conductor 11 can be effectively reduced. Therefore, the saturation magnetic flux density of the magnetic layer 12 is preferably 1.0 T or more, more preferably 1.5 T or more, 1.8 T or more, and 2.0 T or more.

(Electrical characteristics)
It is preferable that the magnetic layer 12 has a higher electrical resistance because eddy currents are less likely to be generated in the magnetic layer 12 itself and eddy current loss can be reduced. In particular, if the specific resistance of the magnetic layer 12 is 20 μΩ · cm or more, generation of eddy currents in the magnetic layer 12 can be more effectively reduced. Since the eddy current in the magnetic layer 12 can be reduced as the specific resistance increases, it is preferably 25 μΩ · cm or more, more preferably 30 μΩ · cm or more, and 50 μΩ · cm or more.

  Considering the viewpoints of the magnetic shield effect and the loss reduction effect, the magnetic layer 12 preferably satisfies both the saturation magnetic flux density of 1.5 T or more and the specific resistance of 20 μΩ · cm or more.

(Construction)
The magnetic layer 12 may have a single layer structure or a multilayer structure of two or more layers. In the case of a multilayer structure, the material of each layer can be different. As an example of the magnetic layer 12 having a multilayer structure, for example, the radially inner (center side) region of the magnetic layer 12 is formed of iron, and the radially outer (front side) region of the magnetic layer 12 is iron. It is mentioned that it is formed with the oxide (iron oxide). Even when a plurality of magnetic layers 12 are provided via an insulating layer to be described later, the material of each layer can be made different.

<Effect of coil wire>
The coil wire 10 is provided with the magnetic layer 12 on the outer periphery of the conductor 11, whereby the magnetic flux of the alternating magnetic field from the outside flows through the magnetic layer 12, thereby reducing the magnetic flux linked to the conductor 11. The coil wire 10 has a magnetic layer 12 having a high magnetic shielding effect, and can sufficiently reduce the magnetic flux interlinking with the conductor 11. Therefore, an eddy current generated in the conductor 11 by an alternating magnetic field from the outside can be suppressed. Loss generated in the conductor 11 can be reduced. The coil wire 10 can be suitably used for a coil used in various electric devices such as a motor.

<Other configuration of coil wire>
(Bs x (t / w))
In the coil wire 10, when the saturation magnetic flux density of the magnetic layer 12 is Bs, the maximum width of the coil wire 10 is w, and the thickness of the magnetic layer 12 is t, Bs × (t / w) ≧ 0. It is preferable to satisfy 01T. As a result of intensive studies, the present inventors have found that the loss generated in the conductor 11 can be significantly reduced when Bs × (t / w) satisfies 0.01 T or more. If the maximum width w of the coil wire 10 is large, the maximum width of the conductor 11 also tends to be large, and the region where the magnetic flux can be linked in the conductor 11 tends to be large. However, since the magnetic saturation is difficult if the saturation magnetic flux density Bs is large to some extent, the magnetic flux that can be linked to the conductor 11 can be reduced even if the magnetic layer 12 can be made to sufficiently flow a magnetic flux and the thickness t is small to some extent. In this case, it is possible to reduce the diameter and thickness of the coil wire 10. Alternatively, if the thickness t is large to some extent, even if the saturation magnetic flux density Bs is small to some extent, the magnetic flux can sufficiently flow through the magnetic layer 12 and the magnetic flux that can be linked to the conductor 11 can be reduced. In this case, the freedom degree of selection of the iron-type material which comprises the magnetic body layer 12 can be raised. If both the saturation magnetic flux density Bs and the thickness t are large, the magnetic flux that can be linked to the conductor 11 can be further reduced, and the coil wire 10 with lower loss can be obtained. As the value of Bs × (t / w) is larger, the effect of suppressing the loss of the conductor 11 tends to be higher. For example, Bs × (t / w) is 0.02T or more, and further 0.05T or more. It is more preferable.
The “maximum width of the coil wire” is, for example, a diameter when the cross-sectional shape of the coil wire 10 is a circle (round wire), a long diameter when it is an ellipse, and a long side length when it is a rectangle (such as a flat wire). It is.
“The thickness of the magnetic layer” is an average value of the thicknesses measured over the entire circumference of the magnetic layer 12. Specifically, the thickness is an average value of at least 10 points measured at equal intervals in the circumferential direction of the magnetic layer 12. When the magnetic layer 12 has a multilayer structure, the total thickness is the total thickness of the layers. In this case, the saturation magnetic flux density Bs is the value of the layer having the minimum value. The maximum width of the coil wire 10 and the thickness of the magnetic layer 12 are measured from the cross section of the coil wire 10.

(Mechanical properties)
The coil wire 10 preferably has a yield stress of 60 MPa or more and a breaking elongation of 5% or more. When the yield stress is 60 MPa or more and the elongation at break is 5% or more, sag resistance is high, workability is excellent, and excellent mechanical properties are obtained. The yield stress is more preferably 70 MPa or more and 80 MPa or more, for example, and the elongation at break is more preferably 10% or more and 15% or more, for example.

(shape)
The shape of the coil wire 10 is not particularly limited. As the shape of the coil wire 10, for example, various shapes such as a circular shape, an elliptical shape, a race track shape, a hexagonal shape, a polygonal shape such as a triangular shape or a rectangular shape can be adopted. Typical shapes of the coil wire 10 include a round wire having a circular cross section and a rectangular wire having a rectangular cross section. The coil wire 10 shown in FIG. 1 is a round wire having a circular cross-sectional shape.

(Insulating layer)
The coil wire 10 may further include an insulating layer 13 (see FIGS. 2A to 2C and FIGS. 3A to 3C) in addition to the magnetic layer 12 on the outer periphery of the conductor 11. The insulating layer 13 is made of, for example, polyimide resin, polyamideimide resin, polyesterimide resin, polyurethane resin, polyester resin, polyolefin resin, polyamide resin, polyethersulfone resin, polyphenylene sulfide resin, polyetheretherketone resin, polytetrafluoroethylene resin, etc. However, the present invention is not limited to this. The insulating layer 13 may have a single layer structure or a multilayer structure of two or more layers. In the case of a multilayer structure, the material of each layer can be different. The thickness of the insulating layer 13 may be appropriately determined according to the magnitude of the current flowing through the conductor 11, and is, for example, 5 μm or more and 500 μm or less.

  As an arrangement form of the insulating layer 13, for example, as shown in FIGS. 2A to 2C, one or both of the outer periphery (radially outer side) of the magnetic layer 12 and between the conductor 11 and the magnetic layer 12. It is mentioned to arrange in. 2A is a form in which an insulating layer 13 is formed on the outer periphery of the magnetic layer 12, FIG. 2B is a form in which the insulating layer 13 is formed between the conductor 11 and the magnetic layer 12, and FIG. In this embodiment, an insulating layer 13A is formed between the magnetic layer 12 and the insulating layer 13B. In addition, for example, as shown in FIGS. 3A to 3C, when the magnetic layer 12 and the insulating layer 13 have a multilayer structure, the magnetic layers 12 and the insulating layers 13 may be alternately arranged. 3A shows a form in which a magnetic layer 12A, an insulating layer 13A, a magnetic layer 12B, and an insulating layer 13B are sequentially formed on the outer periphery of the conductor 11. FIG. 3B shows an insulating layer 13A and a magnetic layer 12A on the outer periphery of the conductor 11. In FIG. 3C, the magnetic layer 12A, the insulating layer 13A, the magnetic layer 12B, the insulating layer 13B, and the magnetic layer 12C are sequentially formed on the outer periphery of the conductor 11. The form which was made is shown.

(Other component layers)
The coil wire 10 may include a lubricating layer (not shown) in which an additive such as a lubricity improver is blended in the outermost layer. In addition, the coil wire 10 may include an adhesion layer (not shown) in which an additive such as an adhesion improver is blended between the conductor 11 or the magnetic layer 12 and the insulating layer 13. Or you may mix | blend additives, such as a lubricity improver, in the insulating layer located in the outermost layer of the wire 10 for coils among the insulating layers 13, and may improve lubricity. In addition, in the insulating layer 13, an adhesive such as an adhesion improver may be blended to improve the adhesion.

  Examples of the lubricity improver include paraffins such as liquid paraffin and solid paraffin, various waxes, and lubricants such as polyethylene resin, fluororesin, and silicone resin. Examples of the lubricating layer include those obtained by binding such a lubricant with a binder resin. For the binder resin, for example, the insulating resin described above, which is a material for forming the insulating layer 13, can be used. . Preferably, the lubricating layer may be formed of an amidoimide resin imparted with lubricity by adding paraffin or wax. Examples of the adhesion improver include acetylenes (such as 1-hexyne), alkynols (such as propargyl alcohol and 1-hexyn-3-ol), aldehydes (such as benzaldehyde and cinnamic aldehyde), and amines (laurylamine, N, N'-dimethylcetylamine, trimethylcetylammonium promide, etc.), mercaptans (cetyl mercaptan, 2-mercaptoimidazole, 5-amino-1,3,4-thiadiazole-2-thiol, etc.), thioureas ( Thiourea, phenylthiourea, etc.) and melamine. Among them, 2-mercaptoimidazole among the mercaptans has a great effect of improving adhesion.

<Method for producing coil wire material>
The coil wire 10 can be manufactured by forming a magnetic layer 12 by coating an iron-based material containing Fe on the outer periphery of a conductor 11 having copper or a copper alloy, or aluminum or an aluminum alloy. . The specific example of the manufacturing method of the coil wire is demonstrated below.

<Mating method>
As an example of the manufacturing method of the coil wire 10, the magnetic layer 12 is formed by covering the outer periphery of the conductor 11 having copper or copper alloy, aluminum or aluminum alloy with an iron-based material containing Fe by fitting. The method of doing is mentioned. The manufacturing method based on this fitting method is the first manufacturing method, and specific steps of the first manufacturing method are shown below.

(A1) An iron-based material containing Fe is disposed around a material wire of a conductor having at least one metal selected from copper, copper alloy, aluminum, and aluminum alloy, and the outer periphery of the material wire is made of iron-based material Arrangement process for preparing covered preparation material.
(A2) A fitting step in which a preparation material is tightened by wire drawing or rolling to produce a composite material in which a ferrous material is fitted to the outer periphery of the material wire.
(A3) A processing step of processing the composite material by drawing or rolling to a predetermined wire diameter to form a magnetic layer on the outer periphery of the conductor.

  In the placement process, as a method of placing the iron-based material on the outer periphery of the conductor material wire, for example, the material wire is inserted into a pipe of iron-based material, or a sheet or tape of iron-based material is placed around the material wire Or wire a ferrous material wire vertically around the material wire along the axial direction. After the iron-based material is disposed on the outer periphery of the material wire, the disposed iron-based material may be joined to the material wire by welding or brazing. The final thickness of the magnetic layer in the coil wire (area ratio of the magnetic layer) can be changed, for example, by changing the thickness of the iron-based material disposed on the outer periphery of the material wire in the preparation material. . In addition, the thickness of the magnetic layer (area ratio of the magnetic layer) also changes depending on the degree of processing (area reduction rate) in the processing step. Therefore, it is preferable to select the size of the prepared pipe, sheet, wire, etc. in consideration of the degree of processing so that a magnetic layer having a desired thickness can be obtained. The conductor material wire constitutes the conductor 11 through a processing step.

  In the fitting step, the conductor material wire and the iron material are fitted and integrated by tightening the iron material from the outside in the radial direction.

  In the processing step, the processing may be repeated until a predetermined wire diameter is obtained. When performing repetitive processing, an intermediate heat treatment step of performing heat treatment between the processing may be provided as necessary. The heat treatment can soften the material and facilitate processing. Moreover, you may further provide the final heat processing process of heat-processing after a process process. From the viewpoint of suppressing the coarsening of the crystal grain size of the conductor while improving workability by softening, the temperature of the heat treatment is, for example, 150 ° C. or more and 900 ° C. or less, and the heat treatment time is, for example, 1 second or more and 10 hours or less. To do. In consideration of the composition of the conductor 11 and the degree of processing, it may be selected from the above range. The same applies to a second manufacturing method using a plating method to be described later. In the case where the conductor 11 is a copper wire, the average crystal grain size is easily set to 200 μm or less when the temperature of the final heat treatment is 500 ° C. or less.

<Plating method>
As another example of the manufacturing method of the coil wire 10, the magnetic material layer 12 is formed by coating the outer periphery of the wire 11 of the conductor 11 having copper or copper alloy, aluminum or aluminum alloy with an iron-based material containing Fe by plating. The method of forming is mentioned. The manufacturing method based on this plating method is the second manufacturing method, and specific steps of the second manufacturing method are shown below.

(B1) A processing step of processing a conductor wire rod having at least one metal selected from copper, copper alloy, aluminum, and aluminum alloy until a predetermined wire diameter is obtained by drawing or rolling.
(B2) A plating step in which an iron-based material containing Fe is plated on the metal-containing wire, and a magnetic layer is formed on the outer periphery of the wire.

  In the second manufacturing method, the order of the processing step and the plating step is not limited. That is, after processing the conductor material wire to a predetermined wire diameter, the processed wire (conductor) may be plated with an iron-based material, or after plating the conductor material wire with an iron-based material, You may process the raw material wire of a conductor until it becomes a predetermined | prescribed wire diameter.

  In the processing step, when the processing is repeatedly performed until a predetermined wire diameter is obtained, an intermediate heat treatment step for performing heat treatment between the processing may be provided as necessary. Moreover, you may further provide the final heat processing process of heat-processing after a process process. The heat treatment temperature is, for example, 150 ° C. or more and 900 ° C. or less, and the heat treatment time is, for example, 1 second or more and 10 hours or less.

  In the plating step, an iron-based material is plated on the outer periphery of the plating target wire by immersing and electrodepositing a plating target wire such as a conductor or a material wire in a plating solution containing Fe. For example, the plating solution may be a plating solution containing ferrous sulfate when plating iron, and a plating solution containing ferrous sulfate and nickel sulfamate when plating permalloy. The thickness of the magnetic layer (area ratio of the magnetic layer) can be changed, for example, by changing the plating thickness of the iron-based material formed on the outer periphery of the wire to be plated by controlling the plating time or current density, or after plating. In the case of processing, it can be changed by further adjusting the processing degree. Prior to the plating step, as a pretreatment, the surface of the wire to be plated is preferably acid washed or degreased. The degreasing treatment is performed, for example, by immersing in an alkaline degreasing solution containing sodium hydroxide or sodium carbonate.

  The first and second manufacturing methods described above may further include an insulating layer forming step for forming an insulating layer. By the insulating layer forming step, a coil wire having an insulating layer on the outer periphery of the conductor as described above can be manufactured. The insulating layer is formed by, for example, baking after applying an insulating resin.

[Example 1]
A coil wire made of oxygen-free copper was prepared, and a coil wire sample No. 1 shown in Table 1 in which the outer peripheral surface of the copper wire was coated with an iron-based material by a fitting method or a plating method. 1-1 to 1-16 and 111,112 were produced.

(Mating method)
Sample No. In 1-1 to 1-7, 1-15, and 111, the surface of a copper wire made of oxygen-free copper was covered with a ferrous material of the material shown in Table 1 to form a magnetic layer. All of the prepared iron-based materials (the following pipes) have an oxygen content of 10 ppm or less and a hydrogen content of 5 ppm or less. For the measurement of each content, an inert gas melting-infrared absorption method is used (the same applies to the plating method described later and Example 2). Specifically, a coil wire was produced as follows. First, a copper wire having a diameter of 11.5 mm and a pipe made of an iron-based material having an inner diameter of 12 mm were prepared, and the copper wire was inserted into the pipe made of the iron-based material and arranged to prepare a preparation material. Next, this preparation material was clamped by drawing through a wire drawing die having a hole diameter of 11 mm to produce a composite material. Next, this composite material was processed by wire drawing or rolling until the shapes and dimensions shown in Table 1 were obtained. In the processing step, when the wire drawing or rolling is repeated until a predetermined shape / dimension is obtained, an intermediate heat treatment is performed after the wire drawing or rolling, and the processing and the heat treatment are repeated. And after processing into the coil wire of the round wire and the flat wire shown in Table 1, the final heat treatment is performed, and further, the insulating coating of polyamideimide resin is applied and baked on the surface of the wire, and the thickness is 50 μm on the outermost periphery. An insulating layer was formed. As described above, a coil wire having a magnetic layer made of an iron-based material on the outer peripheral surface of a conductor (copper wire) and an insulating layer on the outer periphery of the magnetic layer was produced. The silicon content of silicon steel shown in Table 1 is 6% by mass, and the content of Co in permendur is 49% by mass.

  In the coil wire of each sample, the thickness and area ratio of the magnetic layer were adjusted by varying the thickness of each iron-based material pipe to be prepared. The wall thickness of the pipe is about 0.07 mm to 1.0 mm. Table 1 shows the thickness of the pipes prepared for the production of the coil wire of each sample.

(Plating method)
Sample No. In 1-8 to 1-14, 1-16, and 112, the surface of a copper wire made of oxygen-free copper was coated with an iron-based material of the material shown in Table 1 to form a magnetic layer. Specifically, a coil wire was produced as follows. First, a copper wire having a diameter of φ8 mm was prepared, and this copper wire was processed by wire drawing or rolling until it had a predetermined shape and size. In the processing step, when the wire drawing or rolling is repeated until a predetermined shape / dimension is obtained, an intermediate heat treatment is performed after the wire drawing or rolling, and the processing and the heat treatment are repeated. After processing the copper wire into a round wire or a rectangular wire, degreasing treatment and acid cleaning are performed, and then the surface of the copper wire is plated with an iron-based material shown in Table 1 to form a magnetic layer. Coil wires having the shapes and dimensions shown in Table 1 were produced. All of the formed iron-based materials (plating layers) have an oxygen content of 10 ppm or less and a hydrogen content of 5 ppm or less. Furthermore, after applying the final heat treatment to the coil wires of the round wire and the flat wire shown in Table 1, an insulating paint of polyamideimide resin is applied and baked on the surface of the wire material, and an insulating layer having a thickness of 50 μm is formed on the outermost periphery. Formed. As described above, a coil wire having a magnetic layer made of an iron-based material on the outer peripheral surface of a conductor (copper wire) and an insulating layer on the outer periphery of the magnetic layer was produced.

  In the degreasing treatment, electrolytic degreasing was performed by immersing a copper wire in an alkaline degreasing solution containing sodium hydroxide and sodium carbonate and adding a surfactant, and applying current. A sulfuric acid aqueous solution was used for the acid cleaning. In the plating process, when plating iron, a plating solution in which ferrous sulfate is dissolved in a sulfuric acid aqueous solution is used. In the case of permalloy plating, a plating solution in which ferrous sulfate and nickel sulfamate are dissolved in a sulfuric acid aqueous solution is used. Using. In the coil wire of each sample, the thickness and area ratio of the magnetic layer were adjusted by changing the plating time.

  Sample No. In 1-15 and 1-16, the final heat treatment temperature was set to 600 ° C. or higher, and in the other samples, the final heat treatment temperature was set to 200 ° C. to 500 ° C. to adjust the average crystal grain size of the conductor.

  Sample No. The following evaluation was performed for 1-1 to 1-16 and 111,112.

(Measurement of shape)
The cross-section of the coil wire of each sample was observed with an optical microscope, and the dimensions of the coil wire (excluding the insulating layer) and the thickness t of the magnetic layer were measured from the photographed micrograph. The dimensions of the coil wire are expressed by a diameter φ for a round wire and a length (thickness) of a short side × a length (width) of a long side for a rectangular wire. And the cross-sectional area of the coil wire was calculated | required from the dimension of the coil wire. The thickness t of the magnetic layer was the average value of the thickness measured over the entire circumference of the magnetic layer. Here, the average value of thicknesses measured at 16 or more points at equal intervals in the circumferential direction of the magnetic layer was used. Further, the ratio (area ratio) of the cross-sectional area of the magnetic layer to the cross-sectional area of the coil wire (excluding the insulating layer) was determined. Table 1 shows the shape, dimensions, and cross-sectional area of the coil wire, and the material, thickness, and area ratio of the magnetic layer. The size of the conductor (copper wire) can be obtained by subtracting the thickness of the magnetic layer from the coil wire. The area ratio can be calculated by, for example, performing image processing on a micrograph, extracting the conductor and the magnetic layer based on the material, and determining the total cross-sectional area and the cross-sectional area of the magnetic layer, respectively. A commercially available processing apparatus can be used for image processing.

(Measurement of saturation magnetic flux density)
Using a vibrating sample magnetometer (BHV-5, manufactured by Riken Denshi Co., Ltd.), the magnetic flux density-magnetic field curve is measured, the saturation magnetic flux density of the coil wire of each sample is obtained, and the measured value is used for the magnetic layer. The saturation magnetic flux density is obtained. The saturation magnetic flux density is obtained by dividing the measured magnetization M by the volume of the magnetic layer. Then, Bs × (t / w) was obtained using the obtained saturation magnetic flux density Bs, the maximum width w of the coil wire, and the thickness t of the magnetic layer. The maximum width w of the coil wire is the diameter in the case of a round wire and the length (width) of a long side in the case of a flat wire. Table 1 shows the saturation magnetic flux density and Bs × (t / w).

(Measurement of loss)
The measurement circuit shown in FIG. 4 was configured, and the loss in the coil wire of each sample was examined using this measurement circuit. A measurement circuit 100 shown in FIG. 4 includes a C-shaped magnetic core 110 with a gap 111 formed therein, a primary coil 121 and a secondary coil 122 wound around the magnetic core 110, and a signal generator 131. -H analyzer 130 is provided. The loss of the coil wire was measured as follows. A measurement sample S obtained by cutting the coil wire material into a short length (in FIG. 4, a coil wire material having an elliptical cross section with a major axis: minor axis = 2: 1) is inserted into the gap 111 of the magnetic core 110. An excitation signal is generated from the signal generator 131 of the BH analyzer 130, an excitation current i ₁ is passed through the primary coil 121 via the amplifier 132, and an alternating magnetic field is generated in the gap 111. From the AC resistance component obtained by measuring the exciting current i ₁ flowing through the resistor 133 and the induced voltage V ₂ generated at both ends of the secondary coil 122 when the measurement frequency and magnetic flux density of the AC magnetic field are changed, Find the loss. Here, we prepared a comparative sample consisting only of copper wire that has the same material, shape, and size as the coil wire of each sample and does not have a magnetic layer, and similarly measured the loss of each comparative sample. Keep it. And the loss of the wire material for coils of each sample was evaluated by the relative value (%) with respect to 100 as the loss in the comparative sample. The results are shown in Table 1.

(Measurement of average crystal grain size)
The cross section of the coil wire of each sample was etched to expose the crystal structure of the conductor cross section, and the crystal structure was observed with an optical microscope. From the photographed micrograph (magnification: 25 to 200 times), the average grain size was measured based on the cutting method described in “Method for testing grain size of copper products” defined in JIS H 0501 (1986), This was defined as the average crystal grain size of the conductor. The results are shown in Table 1.

(Tensile test)
The coil wire of each sample was subjected to a tensile test using a tensile tester (manufactured by Shimadzu Corporation, AG-5000D) under the test conditions of a distance between chucks of 250 mm and a crosshead speed of 50 mm / min, and a stress-strain curve. Was measured to determine yield stress and elongation at break (elongation). However, the yield stress was the yield point stress for the samples where the yield was remarkable, and the yield strength was 0.2% for the samples that did not show a clear yield point. The results are shown in Table 1.

(Adhesion test)
About the coil wire of each sample, the 90 degree bending test was done and the adhesiveness of a conductor and a magnetic body layer was investigated. Specifically, the longitudinal section of the bent part (cross section passing through the center of the wire and cutting the bent part with a plane) was observed with an optical microscope, and the presence or absence of peeling at the boundary between the conductor and the magnetic layer was examined. . As for the bending test conditions, for the round wire, the bending curvature was 5 times the diameter. The flat wire is so-called edgewise bending that is bent in the width direction, and the bending curvature is five times the width (long side length). The case where peeling was not recognized was designated as “A”, and the case where peeling was observed was designated as “B”. The results are shown in Table 1.

  From the results shown in Table 1, sample No. 1 with an area ratio of the magnetic layer satisfying 3% or more is obtained. 1-1 to 1-16 have a loss of 80% or less, and it can be seen that the loss generated in the conductor by the external AC magnetic field can be greatly reduced. In particular, it is preferable that Bs × (t / w) ≧ 0.01T because the loss can be sufficiently reduced. On the other hand, Sample No. in which the area ratio of the magnetic layer and Bs × (t / w) do not satisfy the above requirements. 111 and 112 have a loss of more than 80%, and the loss generated in the conductor cannot be sufficiently reduced.

  FIG. 5 is based on the results shown in Table 1, with “Bs × (t / w) (T)” on the horizontal axis and “loss (%)” on the vertical axis, and Bs × (t / w) and loss. It is the graph which plotted the relationship of. From the graph shown in FIG. 5, it can be seen that the larger the value of Bs × (t / w), the higher the effect of suppressing the conductor loss.

  Furthermore, sample no. 1-1 to 1-14 and Sample No. From the comparison results with 1-15 and 1-16, a sample with an average crystal grain size of conductor of 200 μm or less has a yield stress of 70 MPa or more, a breaking elongation of 10% or more, and has superior mechanical properties. You can see that

  Sample No. From the result of the adhesion test of 111, depending on the material of the magnetic layer, when the thickness of the magnetic layer is thin (the area ratio of the magnetic layer is small), the adhesion of the magnetic layer is inferior and magnetic It is considered that the body layer is easily peeled off.

[Example 2]
In the same manner as in Example 1 described above, coil wires in which an iron-based material having various compositions are coated on a copper wire made of oxygen-free copper by a fitting method are prepared. Measurement of mechanical properties and the like were performed. The results are shown in Table 2.

  Here, carbon steel, silicon steel, permalloy, iron-based amorphous alloy, and permendule shown in Table 2 were used as the iron-based material. Table 2 shows the Si content for silicon steel and iron-based amorphous alloys, and the Co content for permendurous (both mass%). Neither carbon steel nor permalloy substantially contains Si and Co, and Si and Co are inevitable impurity levels. All of these iron-based materials (the following pipes) have an oxygen content of 10 ppm or less and a hydrogen content of 5 ppm or less.

  The outline of the sample preparation procedure is as follows. A composite material is drawn by drawing a prepared material made of a copper wire having a diameter of 11.5 mm and the above-described iron-based material and having an inner diameter of 12 mm and an appropriate thickness, and the composite material is drawn or rolled. Processing and appropriate intermediate heat treatment were performed to obtain wires having the shapes and sizes (major axis and minor axis) shown in Table 2. The wire having an ellipse shape was produced by performing wire drawing using an ellipse wire drawing die. After the final heat treatment was performed on the obtained wire, an insulating layer (thickness 50 μm) made of polyamideimide resin was formed. As described above, a coil wire having a magnetic layer made of an iron-based material on the outer peripheral surface of a conductor (copper wire) and an insulating layer on the outer periphery of the magnetic layer was produced.

About the obtained coil wire for each sample, in the same manner as in Example 1, the long side length (maximum width w, mm) and short side length (mm) of each wire, the average thickness of the magnetic layer The thickness t, saturation magnetic flux density Bs (T), loss (%), average crystal grain size (μm), yield stress (or 0.2% yield strength, MPa), and elongation at break (%) were measured. Further, using the measured values, the cross-sectional area of the coil wire (excluding the insulating layer), the ratio of the cross-sectional area of the magnetic layer to this cross-sectional area (area ratio,%), and Bs × (t × w) are obtained. It was. The length of the long side and the length of the short side shown in Table 1 are values excluding the insulating layer.
Here, in the measurement of the loss measurement, the arrangement state of the measurement sample S was different from that of Example 1 (the horizontally long arrangement shown in FIG. 4). Specifically, the measurement sample S was inserted into the gap 111 and measured so that the long side of the measurement sample S was arranged in a vertically long direction parallel to the direction of the magnetic flux flowing in the magnetic core 110 (the vertical direction in FIG. 4).

  Furthermore, the specific resistance (μΩ · cm) of the magnetic layer was measured for the obtained coil wire for each sample. The specific resistance was measured using the four probe method. As a test piece for measurement, a ribbon having a length of 150 mm cut out from a pipe made of the iron-based material described above was used. A test piece may be cut out from the magnetic layer of the coil wire.

  As shown in Table 2, sample no. It can be seen that 2-1 to 2-11, 31 to 31 to 42 have low loss when the area ratio of the magnetic layer satisfies 3% to 40%. Here, since any sample satisfies Bs × (t / w) ≧ 0.01T, the loss is low. Specifically, any of the above samples has a loss of about 50% or less, and many of the samples are about 25% or less, compared to a comparative sample having no magnetic layer. Each sample has a conductor average crystal grain size of 200 μm or less, a yield stress of 60 MPa or more (many samples are 70 MPa or more), a breaking elongation of 5% or more (many samples are 10% or more), It can be seen that the mechanical properties are also excellent.

  And, as shown in Table 2, the iron-based material constituting the magnetic material layer satisfies the condition that it contains a large amount of Si or a large amount of Co, so that it is lower than when both conditions are not satisfied. It turns out that it is a loss. Specifically, in the case of silicon steel in which the iron-based material contains 0.5% by mass or more of Si, the loss is 20% or less, and further about 15% or less, and the iron-based material is a permendule containing 40% by mass or more of Co. Then, the loss is 10% or less.

  Further, as shown in Table 2, it can be seen that the loss is lower than that in the case where at least one of the magnetic layers is high and the saturation magnetic flux density Bs is high, as compared with the case where at least one is low. Specifically, the sample No. 1 satisfies a specific resistance of the magnetic layer of 20 μΩ · cm or more and a saturation magnetic flux density Bs of 1.5 T or more. All of 2-2, 2-4 to 2-10, 2-32 to 2-36, and 2-42 have a loss of 20% or less. As the specific resistance is larger and the saturation magnetic flux density is higher, the loss is smaller, and there is a sample that satisfies 15% or less, further 10% or less.

  From this, it can be seen that the loss generated by the external AC magnetic field can be greatly reduced by adjusting the composition of the iron-based material and configuring the magnetic layer with a high specific resistance and high saturation magnetic flux density. The reason for this is that although magnetic flux flows in the magnetic layer in a concentrated manner, the saturation magnetic flux density is high, so that the magnetic saturation of the magnetic layer can be suppressed and the magnetic flux that can be linked to the conductor can be effectively shielded. This is considered to be because the loss of the magnetic material layer can be reduced, and since the magnetic layer has a high specific resistance, an eddy current can hardly be generated in the magnetic material layer itself, and the loss of the magnetic material layer can also be reduced.

  The coil wire of the present invention can be suitably used for coils of motors, reactors, transformers (transformers), IH heaters (induction heating devices), and the like.

DESCRIPTION OF SYMBOLS 10 Coil wire 11 Conductor 12, 12A, 12B, 12C Magnetic body layer 13, 13A, 13B Insulating layer 100 Measurement circuit S Measurement sample (Coil wire)
110 Magnetic Core 111 Gap 121 Primary Coil 122 Secondary Coil 130 BH Analyzer 131 Signal Generator 132 Amplifier 133 Resistance

Claims (6)

A conductor having at least one metal selected from copper, a copper alloy, aluminum and an aluminum alloy and having a cross-sectional area of 0.4 mm ² or more;
An iron-based material containing Fe, and a magnetic layer formed on an outer periphery of the conductor,
A coil wire in which a ratio of a cross-sectional area of the magnetic layer to a cross-sectional area of the conductor and the magnetic layer is 3% or more and 40% or less.   2. The saturation magnetic flux density of the magnetic layer is Bs, the maximum width of the coil wire is w, and the thickness of the magnetic layer is t, Bs × (t / w) ≧ 0.01T is satisfied. The coil wire described in 1.   The coil wire according to claim 1 or 2, wherein the conductor has an average crystal grain size of 200 µm or less.   The coil wire according to any one of claims 1 to 3, wherein the yield stress is 60 MPa or more and the elongation at break is 5% or more.   The coil material according to any one of claims 1 to 4, wherein the iron-based material includes 0.5 mass% or more of Si or 40 mass% or more of Co.   The coil wire according to any one of claims 1 to 5, wherein a saturation magnetic flux density of the magnetic layer is 1.5 T or more, and a specific resistance of the magnetic layer is 20 µΩ · cm or more.

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