JP2024021379A - Enamelled wire and its manufacturing method - Google Patents

Abstract

The present invention provides an enameled wire having an enamel coating on the outer periphery of a conductor, which can prevent the enamel coating from blistering, and a method for manufacturing the same. [Solution] A conductor 2 made of pure copper or a copper alloy, an enamel coating 4 provided to cover the periphery of the conductor 2, and an enamel coating 4 made of pure copper provided between the conductor 2 and the enamel coating 4. An enameled wire 1 is used, which has a peeling suppressing layer 3 that suppresses peeling of the wire. [Selection diagram] Figure 1

Description

The present invention relates to an enameled wire and a method for manufacturing the same.

Winding wires used in motor coils, such as enameled wires (enamel-coated copper wires), are required to have even higher reliability as motors have increased in capacity and become smaller in recent years.

The method for manufacturing enamelled wire is to wire-draw a conductor (hereinafter also referred to as a copper conductor or conductor material) made of copper wire manufactured using a continuous casting and rolling machine, etc., and then coat the outer periphery of a conductor with a resin such as polyimide. It is known to cover with an enamel film as an insulating film consisting of.

Patent Document 1 (Japanese Unexamined Patent Publication No. 2020-191249) describes that a conductive wire is composed of an inner core wire and an outer layer thereof, both of which are made of copper.

Patent Document 2 (Japanese Unexamined Patent Publication No. 1-167906) discloses that when a zirconium copper alloy wire has a plating film on the surface itself, in order to prevent cracks from occurring in the plating film, the periphery of the core material is coated with oxygen-free copper. It is described that it is covered with a covering material consisting of.

Japanese Patent Application Publication No. 2020-191249 Japanese Patent Application Publication No. 1-167906

The enamel coating on the surface of an enameled wire may swell due to the surface properties of the copper conductor, such as cracks or scratches on the copper conductor. If there is a bulge on the surface of the enamelled wire, poor insulation may occur, leading to a decrease in motor reliability.

An object of the present invention is to provide an enameled wire that can prevent blistering of the enamel coating and a method for manufacturing the same.

A brief overview of typical embodiments disclosed in this application will be as follows.

An enameled wire according to one embodiment includes a conductor made of pure copper or a copper alloy, an enamel coating provided to cover the periphery of the conductor, and pure copper, provided between the conductor and the enamel coating, It has a peeling prevention layer that suppresses peeling of the enamel coating.

A method for manufacturing an enameled wire according to an embodiment includes (a) a step of preparing an extending rough wire, (b) a step of forming a peeling suppressing layer covering the outer periphery of the rough wire by a thermal spraying method, and (c) a step of forming a peeling prevention layer covering the outer periphery of the rough wire. A step of forming a drawn wire material by drawing the drawing wire and the peeling suppressing layer, (d) After the (c) step, a step of applying paint to the outer periphery of the peeling suppressing layer, (e) After the (d) step , a step of forming an enamel film around the outer periphery of the anti-peeling layer by baking the paint.

According to one embodiment disclosed in this application, it is possible to provide an enameled wire that can prevent blistering of an enamel coating and a method for manufacturing the same.

FIG. 1 is a cross-sectional view showing an enameled wire according to an embodiment. 1 is a flowchart showing a method for manufacturing an enameled wire according to an embodiment. 1 is a schematic diagram of a copper wire manufacturing apparatus that manufactures copper wire in an enamelled wire manufacturing process according to an embodiment. It is a sectional view of the copper wire manufactured in the manufacturing process of the enamelled wire which is an embodiment. 5 is a schematic diagram showing a manufacturing process following FIG. 4. FIG. FIG. 5 is a cross-sectional view of a copper wire on which a peeling suppressing layer has been formed in a manufacturing process following FIG. 4; FIG. 7 is a cross-sectional view of the wire drawn material after being wire drawn in the manufacturing process following FIG. 6 . FIG. 8 is a cross-sectional view of an enameled wire on which an enamel coating has been formed in a manufacturing process following FIG. 7; It is a sectional view showing an enamelled wire which is a modification of the embodiment. FIG. 3 is a cross-sectional view showing an enameled wire as a comparative example.

Hereinafter, embodiments will be described in detail based on the drawings. In addition, in all the drawings for explaining the embodiment, members having the same function are given the same reference numerals, and repeated explanation thereof will be omitted. Furthermore, in the following embodiments, descriptions of the same or similar parts will not be repeated in principle unless particularly necessary.

In this embodiment, in an enameled wire, an enamel coating is formed on the outer periphery of the conductor at the center of the conductor through a peeling prevention layer for suppressing peeling of the enamel coating from the conductor. Even if there are defects in the enamel coating, the peeling suppressing layer suppresses the inner surface of the enamel coating from peeling off from the conductor side and prevents the enamel coating from swelling. Enamelled wire is used, for example, as a winding wire for motor coils.

<Structure of enameled wire>
The structure of the enameled wire of this embodiment will be explained below using FIG. 1. FIG. 1 is a sectional view showing the enameled wire of this embodiment.

The enameled wire 1 shown in FIG. 1 extends in the depth direction of FIG. 1, and has a circular cross section along the width direction (direction perpendicular to the extending direction). The enameled wire 1 has a conductor 2 which is a single core wire, and a peeling suppressing layer (first coating) 3 is formed on the outer periphery of the conductor 2, and an enamel coating (first coating) is formed on the outer periphery of the peeling suppressing layer. 2 coating) 4 is formed. That is, the enameled wire 1 is composed of a conductor 2, a peeling prevention layer 3, and an enamel coating 4. It is preferable that the peeling suppressing layer 3 is a thermally sprayed coating formed on the outer periphery of the conductor 2 by a thermal spraying method described below.

The conductor 2 is made of pure copper (copper (Cu) with a purity of 99.9 mass% or more) such as oxygen-free copper or tough pitch copper, or a copper alloy. This copper alloy is, for example, made by adding elements other than copper, such as tin (Sn), indium (In), silver (Ag), and magnesium (Mg) to the above-mentioned pure copper. The diameter of the conductor 2 is, for example, 0.1 mm or more and 1.0 mm or less. The peeling suppressing layer 3 is made of pure copper (copper with a purity of 99.9 mass% or more). The thickness of the peeling suppressing layer 3 is 1% or more and 10% or less of the diameter of the conductor 2, preferably 1% or more and 5% or less. The diameter here is the maximum outer diameter in the cross section of the conductor 2. Although not shown, at the interface between the conductor 2 and the peel-off suppressing layer 3, there is a portion where copper crystal grains exist from the conductor 2 to the peel-off suppressing layer 3. The enamel coating 4 is an insulating coating made of an insulating thermosetting resin selected from, for example, polyamideimide, polyimide, or polyesterimide. From the viewpoint of increasing heat resistance, the enamel coating 4 is preferably composed of a thermosetting resin made of polyamideimide or polyimide. Further, the enamel coating 4 has a thickness of, for example, 20 μm or more and 100 μm or less. The thickness of the enamel coating 4 can be adjusted as appropriate depending on changes in characteristics such as withstand voltage. Further, the enamel coating 4 may have a plurality of pores.

The peeling suppressing layer 3 covers all or part of the outer periphery of the conductor 2 . The term "all or part" here refers to a portion in the extending direction of the enameled wire 1, and in the area where the conductor 2 is covered with the peeling suppressing layer 3, the outer periphery of the conductor 2 in the cross section along the radial direction of the enameled wire 1. The peeling suppressing layer 3 continuously covers everything.

The manufacturing method of this embodiment will be described in detail later, but the enameled wire 1 is produced by forming a peeling suppressing layer 3 by thermal spraying or the like on the outer periphery of a rough drawn wire or drawn wire made of copper, which is produced by a continuous casting and rolling machine. , further coated with an enamel coating 4. If the peel-off suppressing layer 3 does not exist and there are defects on the surface of the conductor 2, the gas between the conductor 2 and the enamel coating 4 expands, causing the enamel coating 4 to swell, causing the enamel coating 4 to become attached to the conductor 2. There is a risk of peeling off from the surface (see Fig. 10). In this embodiment, even if the surface of the conductor 2 has the above-described defect, the peeling suppressing layer 3 covers the defect, so that the peeling suppressing layer 3 prevents the inner surface of the enamel coating 4 from peeling off from the conductor 2 side. This can prevent the enamel coating 4 from swelling due to the presence of defects.

<Manufacturing method of enameled wire>
The method for manufacturing an enameled wire according to this embodiment will be described below with reference to FIGS. 2 to 8. FIG. 2 is a flowchart showing a method for manufacturing an enamelled wire according to the present embodiment, and the steps will be explained here with reference to the flow and FIGS. 3 to 8.

Here, first, using the copper wire manufacturing apparatus 100 shown in FIG. 3, a copper wire (copper rough wire) 2A is manufactured (step S1 in FIG. 2). The copper wire manufacturing apparatus 100 according to the present embodiment is a so-called continuous casting and rolling apparatus for continuous casting and rolling of copper wire (copper rough drawn wire). Specifically, the copper wire manufacturing apparatus 100 includes a melting furnace 210, an upper gutter 220, a holding furnace 230, an additive supply section 240, a lower gutter 260, a tundish 300, a pouring nozzle 320, It has a continuous casting machine 500, a hot rolling device 620, and a winding machine (coiler) 640.

The melting furnace 210 heats and melts a copper raw material to produce molten copper 110, and includes, for example, a furnace body and a burner provided at the lower part of the furnace body. Copper raw material is introduced into the furnace body and heated by a burner, so that molten copper 110 is continuously generated. As the copper material, for example, oxygen-free copper or tough pitch copper can be used.

The upper gutter 220 is provided on the downstream side of the melting furnace 210, connects the melting furnace 210 and the holding furnace 230, and transfers the molten copper 110 generated in the melting furnace 210 to the holding furnace 230 on the downstream side. It is.

The holding furnace 230 is provided on the downstream side of the upper gutter 220, and heats the molten copper 110 transferred from the upper gutter 220 at a predetermined temperature and temporarily stores it. Further, the holding furnace 230 transfers a predetermined amount of molten copper 110 to the lower gutter 260 while maintaining the molten copper 110 at a predetermined temperature. An additive supply section 240 for supplying (adding) additives made of alloying elements to the molten copper 110 is connected to the holding furnace 230 . When adding an additive to the conductor 2 shown in FIG. 1, a predetermined alloying element is continuously supplied from the additive supply section 240 to the molten copper 110 in the holding furnace 230. Examples of alloying elements added to the molten copper 110 include magnesium (Mg), aluminum (Al), titanium (Ti), beryllium (Be), zirconium (Zr), cerium (Ce), manganese (Mn), and silicon. (Si) or yttrium (Y). That is, preferably, an alloying element consisting of at least one of these is added to the molten copper 110.

The lower gutter 260 is provided on the downstream side of the holding furnace 230, and is used to transfer the molten copper 110 transferred from the holding furnace 230 to the tundish 300 on the downstream side. Note that the additive supply section 240 is not limited to the mode in which it is connected to the holding furnace 230, but may be connected to the lower gutter 260 or the tundish 300, for example.

The tundish 300 is provided on the downstream side of the lower gutter 260, temporarily stores the molten copper 110 transferred from the lower gutter 260, and continuously supplies a predetermined amount of molten copper 110 to the continuous casting machine 500. It is something to do. In this way, molten copper 110 to be supplied to continuous casting machine 500 is prepared.

A pouring nozzle 320 for flowing out the stored molten copper 110 is connected to the downstream side of the tundish 300. The pouring nozzle 320 is made of, for example, a refractory material such as silicon oxide, silicon carbide, or silicon nitride. Molten copper 110 accumulated in tundish 300 is supplied to continuous casting machine 500 via pouring nozzle 320.

The continuous casting machine 500 is a device that performs so-called belt-wheel continuous casting, and includes, for example, a ring mold 20 and a belt 30. The cylindrical ring mold 20 has a groove on its outer periphery. The ring mold 20 rotates during the copper wire manufacturing process, and its axis of rotation is along a horizontal plane. A cylindrical holding part 50 that holds the ring mold 20 is arranged inside the cylindrical ring mold 20 . The ring mold 20 is fixed to the holding part 50 and rotates together with the holding part 50. Note that the ring mold 20 may be cylindrical or disc-shaped.

Further, the belt 30 is configured to move around while contacting a part of the outer peripheral surface of the ring mold 20. Molten copper 110 flowing out from the tundish 300 is poured into the space between the groove of the ring mold 20 and the belt 30. That is, the tundish 300 and the pouring nozzle 320 are a supply section 330 that supplies the molten copper 110 into the groove of the ring mold 20. Further, the ring mold 20 and the belt 30 are cooled by, for example, cooling water. As a result, the molten copper 110 is cooled and solidified (solidified), and rod-shaped casting bars (casting material) 120 are continuously cast.

The hot rolling device 620 is provided on the downstream side (cast bar discharge side) of the continuous casting machine 500 and continuously rolls the cast bar 120 transferred from the continuous casting machine 500. That is, the hot rolling device 620 is used to pull out the casting bar 120 from the groove of the ring mold 20 and transfer it to the outside of the continuous casting machine 500. The rolled material formed by rolling the cast bar 120 by the hot rolling device 620 is surface-cleaned between the hot rolling device 620 and the winding machine 640, thereby producing copper wire (rough copper wire) 2A. is molded. The diameter of the copper wire 2A here is, for example, about 10 mm.

A winding machine (coiler) 640 is provided on the downstream side (copper alloy material discharge side) of the hot rolling device 620, and is used to collect copper wire (rough wire) transferred from the hot rolling device 620 through a surface cleaning treatment device. It winds up 2A. Through the above steps, it is possible to manufacture the copper wire 2A, which is a rough wire shown in FIG. Here, the surface of the copper wire 2A has no defects over almost the entire surface, but as shown in FIG. 4, defects 5 may be formed near a part of the surface. The defect 5 is a crack or a scratch on the surface of the copper wire 2A.

Next, as shown in FIGS. 5 and 6, a peeling suppressing layer 3 is formed around the outer periphery of the copper wire 2A (step S2 in FIG. 2). The peeling suppressing layer 3 is formed to cover the entire or part of the surface of the copper wire 2A in the extending direction. As a method for forming the peeling suppressing layer 3, for example, as shown in FIG. 5, a thermal spraying method may be used. Specifically, a cold spray method, which is a type of thermal spraying method, can be used, but other thermal spraying methods may also be used. In this case, while running the copper wire 2A in the direction of the arrow shown in FIG. The spray device 6 sprays from the direction. In FIG. 5, four injection devices 6 are used to spray molten copper from four directions, but the number of injection devices 6 may be greater or less than four.

Further, as a method for forming the peeling suppressing layer 3 that is different from the above-mentioned thermal spraying method, a hot-dip plating method or an electrolytic plating method may be used. The hot-dip plating method is a method of passing the copper wire 2A through molten copper to form a peeling suppressing layer 3, which is a copper coating, around the copper wire 2A. The electrolytic plating method is a method in which the copper wire 2A is immersed in an electrolytic solution and electricity is passed through the copper wire 2A to deposit metal around the copper wire 2A, thereby forming the peeling suppressing layer 3. Among these, it is preferable to use the thermal spraying method from the viewpoint of easily forming the peeling suppressing layer 3 made of pure copper around the long copper wire 2A.

By these methods, as shown in FIG. 6, the outer periphery of the copper wire 2A is covered with the peeling suppressing layer 3. At this time, if a defect 5 exists, the entire defect 5 is also covered by the peeling suppressing layer 3. Here, we have explained that the process of forming the peeling suppressing layer 3 is performed on the copper wire 2A, which is a rough drawn wire that has not been subjected to wire drawing, but it is a drawn copper wire that has been subjected to wire drawing on a rough drawn wire. A step of forming the peeling suppressing layer 3 may be performed on the conductive material.

Next, as shown in FIG. 7, the copper wire 2A covered with the peeling suppressing layer 3 is subjected to a wire drawing process to form a drawn wire material in which the outer periphery of the conductor material 2B is covered with the peeling suppressing layer 3. (Step S3 in FIG. 2). The wire drawing process is performed by, for example, preparing a plate with a hole called a die that has a diameter smaller than the copper wire 2A, passing the copper wire 2A through the hole, and thereby reducing the diameter of the copper wire 2A. . Due to the wire drawing process, the diameter of the conductor material 2B and the thickness of the peeling suppressing layer 3 are each made smaller than that of the copper wire 2A. Further, the length of the conductive material 2B and the peeling suppressing layer 3 covering it in the extending direction is longer than that of the copper wire 2A. By performing the wire drawing process, the conductive material 2B and the peeling suppressing layer 3 are brought into close contact with each other at the interface between them, and are connected to each other by metallic bonding. The diameter of the conductor material 2B after wire drawing is, for example, 0.1 mm or more and 1.0 mm or less. This wire drawing process is performed in order to process the conductor material 2B and the peel suppressing layer 3 to the final dimensions even if the peel suppressing layer 3 is formed on the wire drawing material instead of the rough drawn wire in step S2 of FIG. .

Next, heat treatment is performed on the conductor material 2B and the peeling suppressing layer 3 (step S4 in FIG. 2). When the wire is drawn in the wire drawing process (step S3 in FIG. 2), the copper constituting the conductive material 2B and the peeling suppressing layer 3 is hardened. An enameled wire formed using such a hardened conductor material 2B and peeling suppressing layer 3 has low ductility and is therefore unsuitable for winding around a coil. Therefore, by performing the heat treatment, the conductive material 2B and the peeling suppressing layer 3 are softened.

Next, the conductive material 2B and the peeling suppressing layer 3 are cooled (step S5 in FIG. 2). That is, the conductive material 2B and the peeling suppressing layer 3, which have become high in temperature due to the heat treatment (step S4 in FIG. 2), are immersed in cooling water to be cooled. Here, even if a defect 5 occurs on the surface of the conductor material 2B, water will not infiltrate into the defect 5 because the conductor material 2B is protected by the peeling suppressing layer 3.

Next, paint is applied to the outer periphery of the peeling suppressing layer 3 using a coating device (step S6 in FIG. 2). Examples of the material for the paint to be applied here include a paint containing a component that becomes an insulating resin selected from polyamideimide, polyimide, and polyesterimide. Note that the paint may contain a pore-forming agent for forming pores in the enamel coating. Examples of the pore forming agent include high boiling point solvents and thermally decomposable polymers.

Next, while running the conductive material 2B covered with the paint and peeling suppressing layer 3, heat treatment (baking) is performed by heating it in a furnace at 350°C to 500°C for several seconds to several minutes (see Fig. 2). Step S7). Thereby, the paint is cured and an enamel coating 4 is formed. In practice, the above-described painting process (step S6 in FIG. 2) and baking process (step S7 in FIG. 2) are repeatedly performed to form the enamel coating 4 having a laminated structure consisting of a plurality of insulating layers. As described above, the enameled wire 1 having the conductor 2 made of the conductor material 2B, the peeling suppressing layer 3, and the enamel coating 4 shown in FIG. 8 is manufactured.

<Effects of this embodiment>
As a comparative example, the structure of the enameled wire may be one in which the outer periphery of the conductive material 2B is directly covered with the enamel film 4. However, as shown as a comparative example in FIG. 10, when the surface of the conductive material 2B having defects 5 on its surface is covered with the enamel film 4, the enamel film 4 may swell due to the presence of the defects.

The enameled wire 11 of the comparative example is manufactured by performing steps S1, S3 to S7 excluding step S2 among the steps shown in FIG. When there is a defect 5 such as a crack or a scratch caused in the copper wire manufacturing process or the wire drawing process, gas may enter the defect 5. Further, in the cooling process performed after the wire drawing process through heat treatment, cooling water may enter the defects 5 and remain. When the conductor material 2B is covered with the enamel film 4 in this state and heat treated for baking, the gas or water expands between the conductor material 2B and the enamel film 4 due to the heat. As a result, the enamel coating 4 may peel off from the surface of the conductive material 2B and swell.

If peeling occurs in the enamel coating 4 due to such bulging (deformation), for example, when the enameled wire 11 is being wound around a coil, the enamel coating 4 in the area where the bulge has occurred will be torn, and the insulation of the enameled wire 11 will be damaged. Sexuality is impaired. That is, the reliability of the enamelled wire decreases.

A possible method for preventing such blistering of the enamel coating 4 is to perform a peeling process to remove defects on the surface of the copper wire 2A after manufacturing the copper wire 2A. That is, there is a method in which a part of the surface of the copper wire 2A is scraped off. However, in this case, the number of steps increases and copper scraps are generated, resulting in a lower yield. Furthermore, manufacturing costs increase whether the copper scraps are reused or discarded.

On the other hand, in this embodiment, a peeling suppressing layer 3 made of pure copper is formed between the conductor 2 and the enamel coating 4 (see FIG. 1). Therefore, even if a defect 5 occurs on the surface of the conductor 2 (conductor material 2B), peeling of the inner surface of the enamel coating 4 due to the defect 5 can be suppressed, and therefore blistering of the enamel coating 4 can be prevented. That is, even if gas exists inside the defect 5, the expansion of the gas can be suppressed due to the presence of the peeling suppressing layer 3 made of pure copper, which is harder than the enamel film 4. Further, by covering the defect 5 with the peeling suppressing layer 3, the defect 5 is prevented from being exposed. Therefore, the peeling suppressing layer suppresses peeling of the enamel coating 4 from the conductor 2 due to expansion of the gas present inside the defect 5, and the gas expands between the peeling suppressing layer 3 and the enamel coating 4. You can prevent that from happening.

Furthermore, in the cooling process described in step S5 of FIG. 2, since the defect 5 is covered with the peeling suppressing layer 3, water can be prevented from entering the defect 5. Therefore, it is possible to prevent the water from expanding in step S7 of FIG.

Here, when the thickness of the peeling suppressing layer 3 is 1% or more of the diameter of the conductor 2, it is possible to prevent the defects 5 existing on the surface of the conductor 2 from being exposed by the wire drawing process (step S3 in FIG. 2). In addition, when the thickness of the peeling suppressing layer 3 is 10% or less of the diameter, it is easier to form the peeling suppressing layer 3 than when the thickness is larger than 10% of the diameter, and It is possible to improve the workability when forming the wire 1 into a coil shape.

As a result of the above, it is possible to prevent gas or water from expanding between the enamel coating 4 and the conductor 2, so that the enamel coating 4 can be prevented from blistering, and the insulation of the enameled wire 1 can be maintained. That is, it is possible to provide the enameled wire 1 with excellent surface quality and to obtain the highly reliable enameled wire 1.

Furthermore, since there is no need to perform a peeling process to remove the defect 5, no copper scraps are generated. This leads to a reduction in material costs and manufacturing costs when manufacturing the enameled wire 1, so the enameled wire 1 can be provided at low cost. Therefore, it is possible to prevent a decrease in yield and an increase in manufacturing costs due to the increase in process steps and the generation of copper scraps.

<Modified example>
As shown in FIG. 9, the enameled wire 10 may be a rectangular wire. In other words, the conductor 2 of this modification has a rectangular shape in a cross section along the transverse direction (direction perpendicular to the extending direction), and the outer periphery of the conductor 2 is covered with the enamel coating 4 via the peeling suppressing layer 3. There is. That is, the enameled wire 10 and the conductor 2 have two sets of mutually parallel sides in the cross section.

In its cross section, the conductor 2 has a long side length (width) of 1.0 mm or more and 20 mm or less, and a short side length (thickness) of 0.5 mm or more and 5.0 mm or less. The thickness of the peeling suppressing layer 3 is 1% or more and 10% or less of the long side, preferably 1% or more and 5% or less. The length of the long side here is the maximum outer diameter in the cross section of the conductor 2.

As above, the invention made by the present inventors has been specifically explained based on the embodiments, but the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the gist thereof. Needless to say.

1, 10, 11 Enameled wire 2 Conductor 2A Copper wire 2B Conductor material 3 Peeling suppression layer 4 Enamel coating 5 Defect 6 Injection device 20 Ring mold 30 Belt 50 Holding section 100 Copper wire manufacturing device 110 Molten copper 120 Casting bar 210 Melting furnace 220 Upper gutter 230 Holding furnace 240 Additive supply section 260 Lower gutter 300 Tundish 320 Pouring nozzle 330 Supply section 500 Continuous casting machine 620 Hot rolling device 640 Winding machine

Claims (7)

A conductor made of pure copper or copper alloy,
an enamel coating provided to cover the periphery of the conductor;
a peeling suppressing layer made of pure copper, provided between the conductor and the enamel coating, and suppressing peeling of the enamel coating;
Enamelled wire. The enameled wire according to claim 1,
The shape of the conductor in a cross section along the radial direction of the conductor is circular,
The thickness of the peeling suppressing layer is 1% or more and 10% or less of the diameter of the conductor in the cross section. The enameled wire according to claim 1,
The shape of the conductor in a cross section along the short direction of the conductor is rectangular,
The thickness of the peeling suppressing layer is 1% or more and 10% or less of the long side of the conductor in the cross section. (a) The process of preparing rough lines,
(b) forming a peeling suppressing layer covering the outer periphery of the rough drawing line by thermal spraying;
(c) forming a drawn wire material by drawing the rough drawn wire and the peeling suppressing layer;
(d) after the step (c), applying a paint to the outer periphery of the peeling-inhibiting layer;
(e) After the step (d), baking the paint to form an enamel coating around the outer periphery of the peel-inhibiting layer;
A method for manufacturing an enameled wire, comprising: In the method for manufacturing an enameled wire according to claim 4,
(c1) After the step (c), heat-treating the drawn wire material;
(c2) After the step (c1) and before the step (d), cooling the drawn wire material;
A method for producing an enameled wire, further comprising: In the method for manufacturing an enameled wire according to claim 4 or 5,
The enameled wire has a conductor made of pure copper or a copper alloy, the peeling suppressing layer made of pure copper covering the outer periphery of the conductor, and an enamel film,
The shape of the conductor in a cross section along the radial direction of the conductor is circular,
The method for manufacturing an enameled wire, wherein the thickness of the peeling suppressing layer is 1% or more and 10% or less of the diameter of the conductor in the cross section. In the method for manufacturing an enameled wire according to claim 4 or 5,
The enameled wire has a conductor made of pure copper or a copper alloy, the peeling suppressing layer made of pure copper covering the outer periphery of the conductor, and an enamel film,
The shape of the conductor in a cross section along the short direction of the conductor is rectangular,
The method for manufacturing an enameled wire, wherein the thickness of the peeling suppressing layer is 1% or more and 10% or less of the long side of the conductor in the cross section.

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