Method for manufacturing enamel wire

Abstract

To provide a method for manufacturing an enamel wire in which a defect of an enamel wire can be suppressed.SOLUTION: A method for manufacturing an enamel wire includes a flat square rolling step, a flat square wire drawing step, and a coating film forming step. Processing for detecting a defect of a conductor on a stage between the flat square wire drawing step and the coating film forming step is performed, and whether a degree of a defect of the conductor exceeds a first reference is determined. For example, in the case where a degree of a defect of the conductor exceeds the first reference, processing for reducing a defect of the conductor is performed to a device used in the flat square rolling step or the flat square wire drawing step.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing an enameled wire. [Background technology]

[0002] Patent Document 1 discloses a method for producing an enameled wire. The method for producing an enameled wire includes a flat wire rolling process, a flat wire drawing process, and a coating formation process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-122974 A Summary of the Invention [Problem to be solved by the invention]

[0004] When an enameled wire is manufactured, defects may occur in the enameled wire for various reasons. In one aspect of the present disclosure, it is preferable to provide a method for manufacturing an enameled wire that can suppress defects in the enameled wire. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for producing an enameled wire including a flat wire rolling step, a flat wire drawing step, and a coating step. In the method for producing an enameled wire, a process for detecting defects in a conductor between the flat wire drawing step and the coating step is performed, and it is determined whether the degree of the defect in the conductor exceeds a first criterion. According to the method for producing an enameled wire that is one aspect of the present disclosure, defects in the enameled wire can be suppressed. [Brief description of the drawings]

[0006] [Figure 1] FIG. 2 is an explanatory diagram showing the configuration of an enameled wire manufacturing apparatus. [Diagram 2] 4 is a flowchart showing a defect handling process in a manufacturing method of an enameled wire. [Diagram 3] 1A and 1B are explanatory diagrams illustrating why recesses are generated on the surface of a conductor. [Figure 4] 10A and 10B are explanatory diagrams showing another reason why recesses are generated on the surface of a conductor. [Diagram 5] FIG. 2 is an explanatory diagram showing why protrusions are generated on the surface of an enameled wire. [Figure 6] FIG. 2 is an explanatory diagram showing why defects occur on the surface of an enameled wire. [Figure 7] FIG. 2 is an explanatory diagram showing why defects occur on the surface of an enameled wire. [Figure 8] Fig. 8A is a plan view showing a constriction of a conductor, and Fig. 8B is a plan view showing a conductor in which a narrow portion has occurred. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Exemplary embodiments of the present disclosure will now be described with reference to the drawings. First Embodiment 1. Basic steps in the production of enameled wire The basic steps in the method for producing an enameled wire will be described with reference to Fig. 1. In the method for producing an enameled wire, a manufacturing apparatus 10 shown in Fig. 1 is used.

[0008] The manufacturing apparatus 10 includes a bobbin 100, a rectangular rolling machine 12, a rectangular wire drawing machine 13, a cleaning machine 14, a paint applicator 15, a baking furnace 16, and a winder 17. A conductor 1 is wound around the bobbin 100. The material of the conductor 1 is, for example, copper or a copper alloy. The cross section of the conductor 1 is, for example, circular.

[0009] The rectangular rolling machine 12 rolls the conductor 1, which has a circular cross section, into a rectangular shape. The rectangular rolling machine 12 rolls the conductor 1 from above and below and from left to right so that the thickness and width of the conductor 1 become predetermined dimensions, and processes the cross section of the conductor 1 into a rectangular shape. The rectangular rolling machine 12 includes, for example, a cassette roller die (CRD).

[0010] The rectangular wire drawing machine 13 draws the rectangular conductor 1. The rectangular wire drawing machine 13 processes the conductor 1 into a desired dimension. The desired dimension is, for example, a dimension related to the product specifications. The rectangular wire drawing machine 13 includes, for example, a wire drawing die.

[0011] The cleaning device 14 cleans the conductor 1 that has been drawn into a rectangular shape. The cleaning device 14 is provided with a cleaning liquid for cleaning the conductor 1 after drawing. For example, water such as pure water can be used as the cleaning liquid. For example, RO water can be used as the pure water.

[0012] The paint applicator 15 applies enamel wire paint to the cleaned conductor 1. The paint applicator 15 includes, for example, a paint tank that stores enamel wire paint, a paint applicator roll that draws up the enamel wire paint from the paint tank and applies it to the outer peripheral surface of the conductor 1, and a paint die 29 that adjusts the thickness of the enamel wire paint to be uniform. The enamel wire paint is, for example, paint containing a resin and a solvent.

[0013] The baking furnace 16 evaporates the solvent in the enamel wire paint applied to the conductor 1 and hardens the resin in the enamel wire paint. After the solvent evaporates and the resin hardens, the enameled wire 2 is formed. The baking furnace 16 may also be equipped with a drying furnace. The drying furnace only evaporates the solvent in the enamel wire paint. The drying furnace does not harden the resin in the enamel wire paint.

[0014] The basic steps in the production of enameled wire are as follows: (Rectangular rolling process) The conductor 1 wound around the bobbin 100 is introduced into the flat rolling mill 12. The flat rolling mill 12 performs flat rolling on the conductor 1 having a circular cross section. The flat rolling may be performed not only once, but also multiple times in stages using, for example, a multi-stage rolling mill.

[0015] (Flat wire drawing process) Next, the rectangular wire drawing machine 13 performs rectangular wire drawing on the rectangular conductor 1. In this process, in order to smoothly pass the conductor 1 through the wire drawing die, for example, a lubricant containing an emulsion can be used. The area reduction rate in the rectangular wire drawing is, for example, about 20% to 25%. In the rectangular wire drawing process, for example, felt is used. As the felt, for example, a wiping cloth using ultra-fine fibers made of polyester, nylon, etc. can be mentioned. The rectangular conductor 1 is sandwiched between felt from above and below or from the left and right, thereby removing copper powder and foreign matter attached to the surface of the rectangular conductor 1. At this time, it is preferable to use a plate-shaped member having a predetermined thickness wrapped around and covered with felt to sandwich the rectangular conductor 1 from above and below or from the left and right. This makes it easier to remove copper powder attached to the conductor 1 and foreign matter formed by solidifying the lubricant.

[0016] (Cleaning process) Next, the washing device 14 washes the drawn rectangular conductor 1. Washing can remove lubricating oil, moisture, and the like that have adhered to the conductor 1 during the rectangular wiredrawing process. Washing can also remove copper powder (e.g., copper powder that could not be completely removed by felt) that has adhered to the surface of the conductor 1 that has been drawn into a rectangular shape. In other words, the washing process has the function of removing adhesions such as lubricating oil and copper powder that have adhered to the surface of the rectangular conductor 1. (Film formation process) Next, a paint applicator 15 paints the cleaned conductor 1. Specifically, an enamel wire paint is applied to the outer circumference of the conductor 1. Next, a baking furnace 16 dries and hardens the applied enamel wire paint to form an enameled wire 2. The formed enameled wire 2 includes a conductor 1 having a rectangular cross section and a coating 25 that coats the conductor 1. The coating formation process may be repeated until the coating 25 of the enameled wire 2 reaches a desired thickness.

[0017] The enamel wire paint is not particularly limited as long as it can be used for the enamel wire 2. Examples of the solvent in the enamel wire paint include N-methyl-2-pyrrolidone (NMP), cresol, N,N-dimethylacetamide (DMAc), cyclohexanone, etc. Examples of the resin in the enamel wire paint include polyamideimide, polyimide, polyesterimide, etc.

[0018] (winding process) Next, the enameled wire 2 after the coating process is completed is wound by a winder 17. The above-mentioned processes may be performed on the same production line or on separate production lines. For example, the production line may be divided between the cleaning process and the painting process, and the rectangular wire rolling process, rectangular wire drawing process, and cleaning process may be performed on a first production line, and the coating process and winding process may be performed on a second production line.

[0019] The conductor 1 before the flat rolling process may be, for example, a round wire having a circular cross section, a wire having an elliptical cross section, or the like. 2. Treatment of defects in enameled wire manufacturing process In the method for producing an enameled wire, in addition to the basic processes described above, a defect treatment process described below is repeatedly performed at predetermined intervals. The defect treatment process will be described with reference to FIG.

[0020] In step 1 of Fig. 2, a conductor image is acquired from a conductor 1 at a stage between a rectangular wire drawing process and a film forming process. In other words, the conductor 1 from which the conductor image is to be acquired has already been through the rectangular wire drawing process but has not yet been through the film forming process.

[0021] The conductor image is an image that represents the surface of the conductor 1. To obtain the conductor image, for example, a line scanner (for example, an ultra-high definition in-line profile measuring instrument manufactured by Keyence Corporation) can be used. The conductor image is a three-dimensional image including information on the depth of the conductor 1. The resolution in the depth direction (the direction from the surface of the conductor 1 toward the inside of the conductor 1, for example, in FIG. 3, the direction from the surface of the conductor 1 toward the inside of the conductor 1 along the thickness direction of the conductor 1) in the conductor image is, for example, 0.1 μm. The resolution in the width direction in the conductor image is, for example, 2.5 μm. The resolution in the longitudinal direction L in the conductor image is, for example, 58.3 μm. Note that the width direction is the width direction of the conductor 1 (the direction perpendicular to the longitudinal direction L of the conductor 1 in FIG. 8 and parallel to the paper surface of FIG. 8). The longitudinal direction L is the longitudinal direction of the conductor 1. The shooting range of the conductor image is the range in which the entire width direction of the conductor 1 can be shot.

[0022] In step 2, an enameled wire image is obtained from the manufactured enameled wire 2. The enameled wire image is an image showing the surface of the enameled wire 2. The enameled wire image is composed of, for example, a bright-field image and a dark-field image. The bright-field image is an image obtained by irradiating the flat and corner surfaces of the enameled wire 2 with bright-field imaging light and imaging the flat and corner surfaces of the enameled wire 2. The dark-field image is an image obtained by irradiating the flat and corner surfaces of the enameled wire 2 with dark-field imaging light along the longitudinal direction L of the enameled wire 2. To obtain the bright-field image and the dark-field image, for example, an appearance inspection device described in JP 2016-102727 A can be used.

[0023] In step 3, the coating 25 of the produced enameled wire 2 is removed to expose the surface of the conductor 1. Next, an image showing the exposed surface of the conductor 1 (hereinafter referred to as a removal image) is obtained. An optical microscope or a scanning electron microscope (SEM) is used to obtain the removal image. By obtaining the removal image, it is possible to analyze in detail whether the defects present on the surface of the conductor 1 are recesses 23, protrusions, etc. Note that step 3 is preferably performed particularly on an enameled wire that satisfies condition J2, which will be described later. This makes it possible to analyze the cause of the defects on the surface of the enameled wire that satisfies condition J2. Then, in step 6, which will be described later, the results of the analysis of the cause may be used to determine what kind of processing should be performed to reduce the defects.

[0024] In step 4, a defect detection process is performed. The defect detection process includes the following first to third defect detection processes.

[0025] (First defect detection process) Defects in the conductor 1 are detected from the conductor image acquired in step 1. Examples of defects in the conductor 1 include concave portions 23 and convex portions present on the surface of the conductor 1. Another example of a defect in the conductor 1 is a constriction 24 shown in FIG. 8A. The constriction 24 is a portion that occurs locally in the longitudinal direction L of the conductor 1 and is narrower than other portions. Another example of a defect in the conductor 1 is when the width W of the conductor 1 becomes smaller than the normal width W0 as shown in FIG. 8B.

[0026] The constriction 24 and the reduction in width W of the conductor 1 occur for the following reasons. In the flat wire drawing process, if friction between the wire drawing die and the conductor 1 increases within the wire drawing die, or if the conductor 1 gets caught in the wire drawing die within the wire drawing die, the tension applied to the conductor 1 temporarily increases. As a result, in a part of the conductor 1 in the longitudinal direction L, the width W becomes narrower than the normal width W0, resulting in a constriction 24, or the width W of the conductor 1 becomes smaller than the normal width W0 as shown in FIG. 8B.

[0027] The reason why the recesses 23 occur on the surface of the conductor 1 is presumed to be as follows. P1 in Fig. 3 represents the conductor 1 after the first wiredrawing. In the example shown in Fig. 3, the wiredrawing process is performed twice in the rectangular wiredrawing process. The first wiredrawing process is referred to as the first wiredrawing. The second wiredrawing process is referred to as the second wiredrawing. At the stage of P1, no copper powder 21 adheres to the conductor 1. P2 represents the conductor 1 being transported by a pulley provided in the rectangular wiredrawing machine 13 after the first wiredrawing. The copper powder 21 accumulated on the pulley is transferred to the surface of the conductor 1.

[0028] P3 is the conductor 1 during the second drawing. At P3, the copper powder 21 is embedded in the conductor 1. P4 is the conductor 1 after the second drawing and before the cleaning process. The copper powder 21 falls out of the conductor 1. A recess 23 is formed in the conductor 1 where the copper powder 21 was previously present.

[0029] Another reason why the recesses 23 occur on the surface of the conductor 1 is presumed to be as follows. P11 in Fig. 4 is the conductor 1 at a stage after the rectangular rolling process. At the stage of P11, the conductor 1 has no copper powder 21 attached thereto. P12 is the conductor 1 at a stage after the flat rolling process and immediately before the first wire drawing. At P12, copper powder 21 accumulated on the pulley that transports the conductor 1 is transferred to a position on the end side of the conductor 1.

[0030] P13 is the conductor 1 during wire drawing 1. In P13, copper powder 21 is embedded in the conductor 1. P14 is the conductor 1 at a stage between the first and second wiredrawings. At P14, the copper powder 21 falls off from the conductor 1. At P14, a recess 23 is formed in the conductor 1 where the copper powder 21 was previously present. The recess 23 is located at the end side of the conductor 1.

[0031] P15 is the conductor 1 at the stage after the second drawing. The recess 23 moves toward the center of the conductor 1 due to the material being concentrated by the second drawing.

[0032] In P12 to P15, it has been described that the recesses 23 are formed when the copper powder 21 adheres, but the present invention is not limited to this. For example, if a crack due to flat rolling occurs in the same portion where the copper powder 21 adheres in P12, the crack moves to the same position as the recesses 23 in P15. This crack becomes a defect on the surface of the conductor 1.

[0033] (Second defect detection process) From the enameled wire image acquired in step 2, defects on the surface of the enameled wire 2 are detected. Specifically, defects on the flat and corner surfaces of the enameled wire 2 are detected from the bright field image and the dark field image. As a method for detecting defects, for example, the defect detection method described in JP 2016-102727 A can be used. Examples of defects on the surface of the enameled wire 2 include recesses, protrusions, etc. present on the surface of the enameled wire 2.

[0034] The reason why defects occur on the surface of the enameled wire 2 is presumed to be as follows. P21 in Fig. 5 is the conductor 1 at a stage immediately before the coating formation process. A recess 23 exists on the surface of the conductor 1. P22 in Fig. 5 shows enameled wire 2 formed by the coating film forming step. Enameled wire 2 includes conductor 1 and coating 25. Coating 25 covers the surface of conductor 1. When the coating film forming step is performed, the enamel wire paint does not penetrate into recesses 23, and air is trapped in recesses 23. The trapped air foams, causing protrusions 27 to form on the surface of enameled wire 2.

[0035] Another reason why defects occur on the surface of enameled wire 2 is presumed to be as follows. As shown in Figure 6, a coating die 29 is used in the coating process. If conductor 1 is tilted with respect to coating die 29, part of conductor 1 comes into contact with coating die 29, causing scratches on conductor 1. The scratches on conductor 1 cause defects to occur on the surface of enameled wire 2.

[0036] Another reason why defects occur on the surface of the enameled wire 2 is presumed to be as follows. As shown in FIG. 7, a coating die 29 is used in the coating formation process. Foreign matter 31 may adhere to the inner surface of the coating die 29. Examples of foreign matter 31 include copper powder 21 and solidified paint. The foreign matter 31 damages the conductor 1 or the coating 25. As a result, defects occur on the surface of the enameled wire 2.

[0037] (Third defect detection process) Defects on the surface of the conductor 1 are detected from the removal image acquired in step 3. Specifically, an optical microscope or a scanning electron microscope (SEM) is used to detect defects on the surface of the conductor 1 after the coating 25 is removed from the enameled wire 2. Examples of defects in the conductor 1 include recesses 23, protrusions, etc. present on the surface of the conductor 1.

[0038] In step 5, first, the degree of the defect detected in the first to third defect detection processes is calculated. For example, if the defect is a concave portion, the degree of the defect is the depth of the concave portion. For example, if the defect is a convex portion, the degree of the defect is the height of the convex portion. For example, if the defect is a constriction 24, the degree of the defect is the difference between the width W of the conductor 1 at the constriction 24 and the normal width W0. For example, if the defect is that the width W of the conductor 1 is small as shown in FIG. 8B, the degree of the defect is the difference between the width W of the conductor 1 and the normal width W0.

[0039] Next, it is determined whether each of the following conditions J1 to J3 is satisfied. (Condition J1) The degree of the defect detected in the first defect detection process exceeds a preset first standard.

[0040] (Condition J2) The degree of the defect detected in the second defect detection process exceeds a second preset standard. (Condition J3) The degree of the defect detected in the third defect detection process exceeds a third preset standard.

[0041] For example, suppose the defect detected in the first defect detection process is a recess 23, and the depth of the recess 23 is 8 μm. Also, suppose the first standard is 5 μm. In this case, condition J1 is satisfied. On the other hand, if the depth of the recess 23 detected in the first defect detection process is 3 μm, condition J1 is not satisfied. Moreover, if no defect is detected in the first defect detection process, condition J1 is also not satisfied. Similarly, it is determined whether conditions J2 and J3 are satisfied or not.

[0042] If any one of the conditions J1 to J3 is satisfied, proceed to step 6. If none of the conditions J1 to J3 is satisfied, end this process. Note that the process of step 5 may be performed by a human being or automatically by a computer.

[0043] In step 6, a process is performed to reduce defects in the conductor 1 or the enameled wire 2. If the condition J1 is satisfied, a process is performed to reduce defects in the conductor 1 for the equipment used in the flat wire rolling process or the flat wire drawing process. An example of a process for reducing defects in the conductor 1 is a process for suppressing the generation of copper powder 21 shown in Figures 3 and 4. An example of a process for suppressing the generation of copper powder 21 shown in Figures 3 and 4 is a process for replacing the felt or lubricating oil in the rectangular wire drawing machine 13.

[0044] By replacing the felt or the lubricating oil, it is possible to reduce the occurrence of defects such as the recesses 23 shown in FIG. 3 and FIG. 4 on the surface of the conductor 1. In addition, as a process for reducing the occurrence of defects such as the recesses 23 shown in FIG. 3 and FIG. 4, a process for cleaning the surface of the pulley provided in the manufacturing apparatus 10 can be mentioned. By cleaning the surface of the pulley and removing the copper powder 21 accumulated on the surface of the pulley, it is possible to reduce the occurrence of defects such as the recesses 23 shown in FIG. 3 and FIG. 4. For example, when the felt is replaced, it becomes easier to remove or reduce the copper powder 21 attached to the surface of the conductor 1. By removing or reducing the copper powder 21 attached to the surface of the conductor 1, it is possible to prevent the copper powder 21 from clogging the wire drawing die. If the clogging of the copper powder can be prevented, it is possible to prevent the occurrence of new copper powder 21 in the wire drawing die. As a result, defects such as the recesses 23 are less likely to occur on the surface of the conductor 1. In addition, when the lubricating oil is replaced, it is possible to maintain the lubricity inside the wire drawing die, so that it is possible to reduce the resistance (friction, etc.) generated between the wire drawing die and the conductor 1. As a result, it is possible to suppress the generation of new copper powder 21 in the wire drawing die, which makes it difficult for defects such as recesses 23 to occur on the surface of the conductor 1.

[0045] In addition to the recess 23, defects on the surface of the conductor 1 include, for example, a constriction 24 shown in Fig. 8A or a decrease in the width W of the conductor 1 shown in Fig. 8B. These defects are detected in the first defect detection process. Examples of processes for suppressing these defects include a process for adjusting the wiredrawing die so that friction between the wiredrawing die and the conductor 1 does not increase or so that the conductor 1 does not get caught on the wiredrawing die inside the wiredrawing die.

[0046] If condition J2 is satisfied, a process is performed on the equipment used in the flat wire rolling process, the flat wire drawing process, or the coating process to reduce defects on the surface of the enameled wire 2. An example of the process for reducing defects on the surface of the enameled wire 2 is a process for suppressing the generation of copper powder 21 shown in Figs. 3 and 4. An example of the process for suppressing the generation of copper powder 21 shown in Figs. 3 and 4 is a process for replacing the felt or lubricating oil in the flat wire drawing machine 13. Another example of the process for suppressing the generation of copper powder 21 shown in Figs. 3 and 4 is a process for cleaning the surface of a pulley provided in the manufacturing apparatus 10.

[0047] Examples of treatments for reducing defects on the surface of the enameled wire 2 include a treatment for suppressing the inclination of the conductor 1 with respect to the painting die 29 shown in FIG. 6, and a treatment for removing foreign matter 31 shown in FIG. When condition J3 is satisfied, a process for reducing defects on the surface of the conductor 1 is performed on the equipment used in the flat wire rolling process or the flat wire drawing process. An example of the process for reducing defects on the surface of the conductor 1 is a process for suppressing the generation of copper powder 21 shown in Figs. 3 and 4. An example of the process for suppressing the generation of copper powder 21 shown in Figs. 3 and 4 is a process for replacing the felt or lubricating oil in the flat wire drawing machine 13. An example of the process for suppressing the generation of copper powder 21 shown in Figs. 3 and 4 is a process for cleaning the surface of the pulley provided in the manufacturing equipment 10.

[0048] The type of defect reduction process may be fixed, or may be selected from a plurality of processes according to the type and degree of the detected defect. The selection of the defect reduction process may be performed by a human or automatically by a computer.

[0049] 3. Benefits of enameled wire manufacturing method (1A) In the method for producing an enameled wire disclosed herein, a process for detecting defects in a conductor 1 between a rectangular wire drawing process and a coating formation process is performed to determine whether the degree of the defect in the conductor 1 exceeds a first standard. If the degree of the defect in the conductor 1 exceeds the first standard, a process for reducing the defect in the conductor 1 can be performed on the equipment used in the rectangular wire rolling process or the rectangular wire drawing process. This makes it possible to suppress defects in the enameled wire 2.

[0050] In addition, since defects are detected in the conductor 1 before the coating 25 is formed, the reason for the defect is mainly due to the flat wire rolling process or the flat wire drawing process. Therefore, it is easier to identify the reason for the defect compared to detecting defects in the enameled wire 2.

[0051] (1B) In the method for producing an enameled wire according to the present disclosure, a process for detecting defects on the surface of the produced enameled wire 2 is performed. Then, it is determined whether the degree of the defects on the surface of the enameled wire 2 exceeds a second criterion. If the degree of the defects on the surface of the enameled wire 2 exceeds the second criterion, a process for reducing the defects on the surface of the enameled wire 2 is performed on the devices used in the flat wire rolling process, the flat wire drawing process, or the coating formation process. This makes it possible to further reduce the defects in the enameled wire 2. In addition, by detecting both the defects on the surface of the conductor 1 and the defects on the surface of the produced enameled wire 2, it is possible to determine whether the defects on the surface of the enameled wire 2 are caused by the defects on the surface of the conductor 1. This makes it easier to determine whether to perform a process for reducing the defects in the conductor 1.

[0052] (1C) In the method of producing an enameled wire disclosed herein, coating 25 is removed from produced enameled wire 2, and a process is performed to detect defects on the surface of conductor 1. Then, it is determined whether the degree of the defects on the surface of conductor 1 exceeds a third criterion. If the degree of the defects on the surface of conductor 1 exceeds the third criterion, a process is performed to reduce the defects on the surface of conductor 1 for the equipment used in the flat wire rolling process or the flat wire drawing process. This makes it possible to further suppress defects in enameled wire 2.

[0053] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0054] (1) In the first embodiment, the first to third defect detection processes were performed, but one or both of the second and third defect detection processes may not be performed. If the second defect detection process is not performed, it may not be necessary to determine whether or not the condition J2 is satisfied. If the third defect detection process is not performed, it may not be necessary to determine whether or not the condition J3 is satisfied.

[0055] (2) The results of the first to third defect detection processes may be combined to determine the type of process to be executed in step 6. The type of process to be executed in step 6 may be determined by a human being or automatically by a computer. (3) The device for acquiring the conductor image may be a device other than a line scanner. The enamel wire image may be an image other than one consisting of a bright-field image and a dark-field image. The device for acquiring the removal image may be a device other than either an optical microscope or a scanning electron microscope.

[0056] (4) The function of one component in each of the above embodiments may be shared by multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Also, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0057] (5) In addition to the above-described method for producing an enameled wire, the present disclosure can be realized in various forms, such as an apparatus for producing an enameled wire.

[0058] [Technical idea disclosed in this specification] [Item 1] A method for producing an enameled wire, comprising a flat wire rolling step, a flat wire drawing step, and a coating forming step, A process for detecting defects in the conductor in a stage between the flat wire drawing process and the coating forming process is performed; determining whether the degree of the defect in the conductor exceeds a first criterion; Manufacturing method of enameled wire. [Item 2] A method for producing an enameled wire according to item 1, comprising the steps of: If the degree of the defect in the conductor exceeds the first standard, a process for reducing the defect in the conductor is performed on an apparatus used in the flat wire rolling process or the flat wire drawing process. Manufacturing method of enameled wire. [Item 3] A method for producing an enameled wire according to item 1 or 2, comprising the steps of: A process for detecting defects on the surface of the manufactured enameled wire is carried out; determining whether the degree of the defect on the surface of the enameled wire exceeds a second criterion; If the degree of defects on the surface of the enameled wire exceeds the second standard, a process for reducing defects on the surface of the enameled wire is performed on a device used in the flat wire rolling process, the flat wire drawing process, or the coating forming process. Manufacturing method of enameled wire. [Item 4] A method for producing an enameled wire according to any one of items 1 to 3, removing the coating of the produced enameled wire and carrying out a process to detect defects on the surface of the conductor; determining whether the degree of defects on the surface of the conductor exceeds a third criterion; If the degree of defects on the surface of the conductor exceeds the third standard, a process for reducing defects on the surface of the conductor is performed on an apparatus used in the flat wire rolling process or the flat wire drawing process. Manufacturing method of enameled wire. [Explanation of symbols]

[0059] Reference Signs List 1...conductor, 2...enamel wire, 10...manufacturing equipment, 12...rectangular wire rolling machine, 13...rectangular wire drawing machine, 14...cleaning equipment, 15...paint applicator, 16...baking furnace, 17...winder, 21...copper powder, 23...depression, 24...neck, 25...coating, 27...protrusion, 29...painting die, 31...foreign matter, 100...bobbin

Claims

1. A method for producing an enameled wire, comprising a flat wire rolling step, a flat wire drawing step, and a coating forming step, A process for detecting defects in the conductor in a stage between the flat wire drawing process and the coating forming process is performed; determining whether the degree of the defect in the conductor exceeds a first criterion; Manufacturing method of enameled wire.

2. 2. A method for producing an enameled wire according to claim 1, comprising the steps of: If the degree of the defect in the conductor exceeds the first standard, a process for reducing the defect in the conductor is performed on an apparatus used in the flat wire rolling process or the flat wire drawing process. Manufacturing method of enameled wire.

3. 3. A method for producing an enameled wire according to claim 1, further comprising the steps of: A process for detecting defects on the surface of the manufactured enameled wire is carried out; determining whether the degree of the defect on the surface of the enameled wire exceeds a second standard; If the degree of defects on the surface of the enameled wire exceeds the second standard, a process for reducing defects on the surface of the enameled wire is performed on an apparatus used in the flat wire rolling process, the flat wire drawing process, or the coating forming process. Manufacturing method of enameled wire.

4. 3. A method for producing an enameled wire according to claim 1, further comprising the steps of: removing the coating of the produced enameled wire and carrying out a process to detect defects on the surface of the conductor; determining whether the degree of defects on the surface of the conductor exceeds a third criterion; If the degree of defects on the surface of the conductor exceeds the third standard, a process for reducing defects on the surface of the conductor is performed on an apparatus used in the flat wire rolling process or the flat wire drawing process. Manufacturing method of enameled wire.

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