Manufacturing method for rectangular enamel copper wire

Abstract

To provide a manufacturing method for a rectangular enamel copper wire capable of suppressing occurrence of an appearance abnormal part.SOLUTION: In a manufacturing method for rectangular enamel copper wire, continuous cold wire drawing is performed on a rectangular copper wire using a rectangular drawing die to produce a rectangular copper drawn material. An enamel coating material is applied to a surface of the rectangular copper drawn material, and baking is performed. A copper powder removal process being the process of removing copper powder generated by the cold wire drawing at both an inlet side and an outlet side of the rectangular drawing die is performed. For example, the copper powder removal process is performed in a state where the rectangular drawing die is mounted on a manufacturing apparatus for the rectangular enamel copper wire.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] An enameled wire comprises a conductor and an enamel coating. The conductor is mainly made of copper. The enamel coating covers the surface of the conductor. Patent Document 1 describes a method for manufacturing an enameled wire. In this method, paint is applied to the surface of the conductor to form a coating film. The enamel coating is then formed by baking. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-249293 Summary of the Invention [Problem to be solved by the invention]

[0004] Enameled wire includes rectangular enameled copper wire. The conductor of rectangular enameled copper wire is rectangular drawn copper wire material. Rectangular drawn copper wire material is a conductor with a rectangular cross section. Rectangular drawn copper wire material is produced by continuously cold drawing rectangular copper wire using a rectangular wire drawing die.

[0005] Cold wire drawing generates and accumulates copper powder in the rectangular wire drawing die. Some of the accumulated copper powder is pressed onto the rectangular copper wire. The pressed copper powder is partially peeled off from the rectangular copper wire by the wire drawing die, capstan, etc. When paint is applied to the surface of the rectangular copper wire, bubbles form on the surface of the rectangular copper wire, originating from the areas where the copper powder has peeled off. The areas where bubbles have formed become areas with an abnormal appearance (hereinafter referred to as "visually abnormal areas"). This is one of several types of visually abnormal areas.

[0006] The technology described in Patent Document 1 attempts to remove copper powder by injecting a liquid lubricant near the entrance of a wire drawing die. However, with the technology described in Patent Document 1, it was difficult to sufficiently remove copper powder accumulated on the flat wire drawing die and prevent the occurrence of visual defects.

[0007] In one aspect of the present disclosure, it is preferable to provide a method for producing a rectangular enameled copper wire that can suppress the occurrence of visual defects. [Means for solving the problem]

[0008] One aspect of the present disclosure is a method for manufacturing a rectangular enameled copper wire, which comprises continuously cold drawing a rectangular copper wire using a rectangular wire drawing die to produce a rectangular copper wire material, applying an enamel paint to the surface of the rectangular copper wire material, and baking the paint; and further comprising a copper powder removal process, which removes copper powder generated by the cold wire drawing process at the inlet and outlet sides of the rectangular wire drawing die.

[0009] According to a method for producing a rectangular enameled copper wire that is one aspect of the present disclosure, it is possible to suppress the occurrence of visual defects in the rectangular enameled copper wire. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram showing the configuration of a manufacturing device for a rectangular enameled copper wire. [Figure 2] FIG. 2 is a cross-sectional view showing the cross-sectional shape of a rectangular copper wire. [Figure 3] FIG. 2 is a cross-sectional view showing the cross-sectional shape of a drawn rectangular copper wire. [Figure 4] FIG. 2 is a side view showing the configuration of a rectangular wire drawing machine. [Figure 5] Fig. 5A is a front view showing the configuration of a flat wire drawing die, and Fig. 5B is a side view showing the configuration of the flat wire drawing die. [Figure 6] Fig. 6A is an explanatory diagram showing an enamel particle existing alone, and Fig. 6B is an explanatory diagram showing an open cell. DETAILED DESCRIPTION OF THE INVENTION

[0011] Exemplary embodiments of the present disclosure will now be described with reference to the drawings. First Embodiment 1.Outline of manufacturing method for rectangular enamelled copper wire An outline of a method for manufacturing a rectangular enameled copper wire will be explained with reference to Figures 1 to 3. The method for manufacturing a rectangular enameled copper wire uses a manufacturing apparatus 1 for rectangular enameled copper wire shown in Figure 1. The manufacturing apparatus 1 for rectangular enameled copper wire includes a dance ring or bobbin 3, a round wire drawing machine 5, a rectangular rolling mill 7, an annealing furnace 9, a rectangular wire drawing machine 11, an annealing furnace 13, a paint applicator 15, a baking furnace 17, and a winder 19.

[0012] A linear conductor 23 is wound around the dance ring or bobbin 3. The conductor 23 is drawn out from the dance ring or bobbin 3, travels along a route that passes through the round wire drawing machine 5, the flat wire rolling mill 7, the annealing furnace 9, the flat wire drawing machine 11, the annealing furnace 13, the coating machine 15, and the baking furnace 17 in this order, and is wound onto the winder 19. However, the conductor 23 passes through the section that includes the coating machine 15 and the baking furnace 17 multiple times.

[0013] The conductor 23 is made of copper or a copper alloy. The cross-sectional shape of the conductor 23 is circular until it is subjected to flat-rolling, which will be described later. The cross-section of the conductor 23 is a cross section perpendicular to the longitudinal direction of the conductor 23.

[0014] The round wire drawing machine 5 draws the conductor 23 having a circular cross section. The flat wire rolling machine 7 performs flat rolling on the traveling conductor 23. The conductor 23 that has been flat-rolled is referred to as a flat copper wire 23A.

[0015] As shown in Figure 2, the cross-sectional shape of the flat copper wire 23A is a shape consisting of two parallel sides 24A, 24B and two arc-shaped end faces 26A, 26B. In the cross-section, the sides 24A, 24B are straight. In the cross-section, the lengths of the sides 24A, 24B are greater than the lengths of the end faces 26A, 26B. The annealing furnace 9 anneals the flat copper wire 23A.

[0016] The flat wire drawing machine 11 performs flat wire drawing on the running flat copper wire 23A. Flat wire drawing is a process in which the flat copper wire 23A is continuously cold-drawn using a flat wire drawing die 31, which will be described later. The conductor 23 that has undergone flat wire drawing is referred to as a flat copper wire material 23B. The configuration of the flat wire drawing machine 11 will be described later.

[0017] The cross-sectional shape of the drawn rectangular copper wire material 23B is a rounded rectangle, as shown in Fig. 3. The long sides of the rounded rectangle are sides 24A and 24B. The short sides 22A and 22B of the rounded rectangle are sides that originate from end faces 26A and 26B of the rectangular copper wire 23A.

[0018] As shown in Figure 1, in the rectangular wire drawing machine 11, the direction in which the conductor 23 travels is referred to as the traveling direction TR. The opposite direction to the traveling direction TR is referred to as the upstream direction US. The annealing furnace 13 anneals the rectangular copper wire material 23B. The paint applicator 15 applies enamel paint to the surface of the rectangular copper wire material 23B, thereby forming an enamel paint film of a predetermined thickness on the surface of the rectangular copper wire material 23B.

[0019] In the baking furnace 17, a coating of enamel paint of a predetermined thickness is formed on the traveling drawn rectangular copper wire material 23B by applying heat to bake it, thereby forming a coating. As shown in Figure 1, the application of enamel paint by the paint applicator 15 and the formation of the coating by the baking furnace 17 are repeated. As a result, a rectangular enameled copper wire 25 having a predetermined coating thickness is produced. The rectangular enameled copper wire 25 is taken up by the winder 19.

[0020] The coating is formed, for example, by the following method: An enamel coating is applied to the surface of the drawn rectangular copper wire 23B. The enamel coating is, for example, a coating containing a resin and a solvent. Next, the solvent in the enamel coating applied to the surface of the drawn rectangular copper wire 23B is evaporated, and the resin in the enamel coating is hardened. After the solvent has evaporated and the resin has hardened, the rectangular enameled copper wire 25 is formed.

[0021] 2. Configuration of the flat wire drawing machine 11 The configuration of the flat wire drawing machine 11 will be described with reference to Figures 4, 5A, and 5B. As shown in Figure 4, the flat wire drawing machine 11 includes a flat wire drawing die 31, a die holder 33, injection nozzles 35A, 35B, 35C, and 35D, and a die presser 37.

[0022] The flat wire drawing die 31 produces a flat copper wire material 23B by continuously performing cold wire drawing. As shown in Figures 4, 5A, and 5B, the flat wire drawing die 31 has a flat-shaped processing hole 39. The conductor 23 passes through the processing hole 39 while traveling in the traveling direction TR. Before passing through the processing hole 39, the conductor 23 is a flat copper wire 23A. After passing through the processing hole 39, the conductor 23 is a flat copper wire material 23B.

[0023] The die holder 33 holds the flat wire drawing die 31. The spray nozzles 35A and 35B are provided upstream of the flat wire drawing die 31 in the upstream direction US. The spray nozzles 35A and 35B spray a cleaning member 41 toward the entrance side 31A of the flat wire drawing die 31. The cleaning member 41 is, for example, air or a wire drawing lubricant. The entrance side 31A is the portion of the flat wire drawing die 31 on the upstream direction US side, surrounding the processing hole 39. The spray nozzle 35A sprays the cleaning member 41 toward the entrance side 31A from diagonally above. The spray nozzle 35B sprays the cleaning member 41 toward the entrance side 31A from diagonally below.

[0024] The spray nozzles 35C and 35D are located further in the running direction TR than the flat wire drawing die 31. The spray nozzles 35C and 35D spray a cleaning member 41 toward the outlet side 31B of the flat wire drawing die 31. The cleaning member 41 is, for example, air or a wire drawing lubricant. The outlet side 31B is the portion of the flat wire drawing die 31 on the running direction TR side, surrounding the processing hole 39. The spray nozzle 35C sprays the cleaning member 41 toward the outlet side 31B from an obliquely upward direction. The spray nozzle 35D sprays the cleaning member 41 toward the outlet side 31B from an obliquely downward direction. The die holder 37 holds the flat wire drawing die 31 to prevent it from coming off the die holder 33.

[0025] 3. Copper powder removal treatment The rectangular wire drawing machine 11 can perform a copper powder removal process. The copper powder removal process is a process for removing copper powder accumulated on the entrance side 31A and the exit side 31B. When the rectangular wire drawing die 31 continuously performs cold wire drawing, copper powder is generated and accumulates on the entrance side 31A and the exit side 31B.

[0026] The copper powder removal process is a process in which, for example, spray nozzles 35A, 35B, 35C, and 35D are used to spray cleaning material 41 onto inlet side 31A and outlet side 31B. By spraying cleaning material 41, copper powder accumulated on inlet side 31A and outlet side 31B can be removed. The cleaning material 41 is, for example, air or a wire drawing lubricant.

[0027] The copper powder removal process can be performed, for example, with a flat wire drawing die 31 attached to the flat enameled copper wire manufacturing apparatus 1. The state in which the flat wire drawing die 31 is attached to the flat enameled copper wire manufacturing apparatus 1 is a state in which the die holder 33 holds the flat wire drawing die 31, as shown in FIG.

[0028] When the copper powder removal process is performed with the flat wire drawing die 31 attached to the flat enameled copper wire manufacturing apparatus 1, the productivity of the flat enameled copper wire 25 is improved compared to when the copper powder removal process is performed with the flat wire drawing die 31 removed from the flat enameled copper wire manufacturing apparatus 1.

[0029] Furthermore, if the copper powder removal process is performed with the flat wire drawing die 31 removed from the flat enameled copper wire manufacturing apparatus 1, the following steps (a) to (g) are required, which reduces the productivity of the flat enameled copper wire 25.

[0030] (a) The state of the rectangular enameled copper wire manufacturing apparatus 1 is changed from high-temperature / high-speed operation to low-temperature / low-speed operation, and the supply of enamel paint is stopped. (b) The operation of the rectangular enameled copper wire manufacturing apparatus 1 is stopped.

[0031] (c) The rectangular wire drawing die 31 is removed and copper powder removal processing is carried out. (d) The flat wire drawing die 31 is attached and its position and orientation are adjusted. When adjusting the position and orientation of the flat wire drawing die 31, the orientation of the flat-shaped processing hole 39 must be accurately adjusted, so this takes more time than adjusting the position and orientation of the die of the round wire drawing machine 5.

[0032] (e) The state of the rectangular enameled copper wire manufacturing apparatus 1 is changed to low temperature and low speed operation, and the supply of enamel paint is resumed. (f) The state of the rectangular enameled copper wire manufacturing apparatus 1 is changed to high temperature / high speed operation, and the thickness of the enamel coating is adjusted. (g) Resume production of rectangular enameled copper wire 25.

[0033] The copper powder removal process can be performed, for example, with the flat wire drawing die 31 attached to the flat enameled copper wire manufacturing apparatus 1, and with the conductor 23 traveling in the traveling direction TR while passing through the processing hole 39 (i.e., with the cold wire drawing process being performed). Also, the copper powder removal process can be performed, for example, with the flat wire drawing die 31 attached to the flat enameled copper wire manufacturing apparatus 1, and with the conductor 23 stationary.

[0034] For example, the copper powder removal process can be performed when the degree of occurrence of visual defects in the manufactured rectangular enameled copper wire 25 exceeds a predetermined standard. For example, if the degree of occurrence of visual defects in the manufactured rectangular enameled copper wire 25 does not exceed a predetermined standard, the copper powder removal process can be omitted.

[0035] The occurrence of visually abnormal portions exceeds a predetermined standard when, for example, the number of visually abnormal portions present in a section of length L in rectangular enameled copper wire 25 exceeds a standard number. Length L is the length of rectangular enameled copper wire 25 in the longitudinal direction. Length L is, for example, 3200 mm. Length L is, for example, the length of rectangular enameled copper wire 25 wound around one bobbin. The standard number is, for example, a fixed value of 30.

[0036] The appearance abnormality is, for example, as shown in Figures 6A and 6B, a granular foreign substance (hereinafter referred to as enamel grains 51) that appears on the surface of rectangular enameled copper wire 25. Enamel grains 51 are generated when the surface of rectangular drawn copper wire 23B is painted with enamel paint, and bubbles form at the location where copper powder peels off on the surface of rectangular drawn copper wire 23B. This is one of several types of appearance abnormalities.

[0037] The number of visually abnormal portions can be counted, for example, as follows: As shown in Fig. 6A, if one enamel grain 51 is present sufficiently far from other enamel grains 51, it is determined that one visually abnormal portion exists. For example, if only one enamel grain 51 exists within the field of view of the camera image, it is determined that one visually abnormal portion exists.

[0038] As shown in Figure 6B, if multiple enamel particles 51 are aligned along one direction D and both of the following conditions J1 and J2 are satisfied, the multiple enamel particles 51 are determined to be one continuous cell 53.

[0039] (J1) The width W is 0.5 mm or more. (J2) The aspect ratio A is 4 or more. The width W is the overall width of the plurality of enamel grains 51 in a direction perpendicular to the direction D. The aspect ratio A is the value obtained by dividing the length P by the width W. The length P is the overall length of the plurality of enamel grains 51 in the direction D.

[0040] When one open cell 53 is present, it is determined that there are n appearance abnormalities represented by the following formula (1). Equation (1) n=f(P / P0) In equation (1), P / P0 is the value obtained by dividing P by P0. P0 is a fixed value, for example, 32 mm. P0 is, for example, the width of the field of view in an image obtained by capturing an image of the surface of rectangular enameled copper wire 25 with a camera. In equation (1), f(P / P0) is the smallest integer greater than P / P0. For example, if P / P0 is 0.5, f(P / P0) is 1. For example, if P / P0 is 1.5, f(P / P0) is 2.

[0041] As a method for detecting the appearance abnormality, for example, a method for capturing an image of the surface of rectangular enameled copper wire 25 with a camera and detecting the appearance abnormality in the image can be mentioned. Also, as a method for detecting the appearance abnormality, for example, a visual inspection method described in JP 2016-102724 A can be mentioned.

[0042] In the appearance inspection method described in JP 2016-102724 A, bright-field imaging light is irradiated onto the flat and corner surfaces of a rectangular enameled copper wire 25 moving in the longitudinal direction, and bright-field images of the flat and corner surfaces are captured. Dark-field imaging light is also irradiated along the longitudinal direction of the rectangular enameled copper wire 25, and dark-field images of the flat and corner surfaces are captured. Next, the presence or absence of visual anomalies on the flat and corner surfaces is determined in each of the bright-field and dark-field images. The size of the visual anomalies is also measured.

[0043] 4. Benefits of the manufacturing method for rectangular enamelled copper wire (1A) In the method for manufacturing a rectangular enameled copper wire according to the present disclosure, a copper powder removal process is performed. The copper powder removal process removes copper powder accumulated on the inlet side 31A and the outlet side 31B. By performing the copper powder removal process, copper powder accumulated on the inlet side 31A and the outlet side 31B can be removed. By removing the copper powder accumulated on the inlet side 31A, the copper powder is less likely to be pressed onto the rectangular copper drawn wire material 23B. Furthermore, by removing the copper powder accumulated on the outlet side 31B, the copper powder is less likely to flow to subsequent processes along with the rectangular copper drawn wire material 23B. As a result, the occurrence of visual defects in the rectangular enameled copper wire 25 can be suppressed.

[0044] (1B) In the method for manufacturing a rectangular enameled copper wire according to the present disclosure, for example, the copper powder removal process is performed with the rectangular wire drawing die 31 attached to the rectangular enameled copper wire manufacturing apparatus 1. In this case, the above-described steps (a) to (g) do not need to be performed, and therefore the productivity of the rectangular enameled copper wire 25 is improved.

[0045] (1C) In the method for producing a rectangular enameled copper wire according to the present disclosure, for example, if the degree of occurrence of visual defects in the produced rectangular enameled copper wire 25 exceeds a preset standard, copper powder removal treatment can be performed. In this case, the occurrence of visual defects in the rectangular enameled copper wire 25 can be further suppressed for the following reasons.

[0046] If the degree of appearance defects in the manufactured rectangular enameled copper wire 25 is below a predetermined standard, performing the copper powder removal process may actually increase the number of appearance defects. This is presumably because the copper powder removed from the rectangular wire drawing die 31 by the copper powder removal process adheres to the rectangular copper drawn wire material 23B.

[0047] If copper powder removal processing is performed when the degree of occurrence of visually abnormal parts in the manufactured rectangular enameled copper wire 25 exceeds a preset standard, such a situation can be prevented from occurring.

[0048] (1D) The copper powder removal process is, for example, a process of spraying air or a wire drawing lubricant onto the inlet side 31A and the outlet side 31B. In this case, the occurrence of visual defects in the rectangular enameled copper wire 25 can be further suppressed.

[0049] <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.

[0050] (1) The rectangular wire drawing machine 11 may not include some of the jet nozzles 35A, 35B, 35C, and 35D. For example, the rectangular wire drawing machine 11 may not include one of the jet nozzles 35A and 35B. Also, the rectangular wire drawing machine 11 may not include one of the jet nozzles 35C and 35D.

[0051] (2) The jet nozzles 35A and 35B may be aligned horizontally. The jet nozzles 35C and 35D may be aligned horizontally. (3) The number of injection nozzles 35A may be two or more. The same applies to the numbers of injection nozzles 35B, 35C, and 35D. For example, the number of injection nozzles 35A may be one and the number of injection nozzles 35B may be two. For example, the number of injection nozzles 35A may be two and the number of injection nozzles 35B may be one. For example, the number of injection nozzles 35C may be one and the number of injection nozzles 35D may be two. For example, the number of injection nozzles 35C may be two and the number of injection nozzles 35D may be one.

[0052] (4) The rectangular wire drawing machine 11 may further include horizontally aligned spray nozzles in addition to the spray nozzles 35A and 35B upstream in the direction US from the rectangular wire drawing die 31. The rectangular wire drawing machine 11 may further include horizontally aligned spray nozzles in addition to the spray nozzles 35C and 35D upstream in the direction TR from the rectangular wire drawing die 31.

[0053] (5) For example, the copper powder removal process may be performed every time a certain length of rectangular enameled copper wire 25 is manufactured. Also, the copper powder removal process may be performed every time a certain time period elapses. (6) The copper powder removal process may be a process different from the process of spraying air or wire drawing lubricant.

[0054] (7) The manufacturing apparatus 1 for flat enameled copper wire may include two or more flat wire drawing machines 11. In this case, the conductor 23 passes through the two or more flat wire drawing machines 11 in sequence. For example, the copper powder removal process may be performed in all of the two or more flat wire drawing machines 11. Alternatively, the copper powder removal process may be performed in some of the two or more flat wire drawing machines 11, while not in the other flat wire drawing machines 11. It is preferable to perform the copper powder removal process in the flat wire drawing machine 11 located most upstream in the US direction. Copper powder is particularly likely to accumulate in the flat wire drawing machine 11 located most upstream in the US direction. Therefore, performing the copper powder removal process in the flat wire drawing machine 11 located most upstream in the US direction is more effective in suppressing the occurrence of visual defects. (8) The cleaning member 41 may be a gas other than air. Examples of gas other than air include nitrogen gas. The cleaning member 41 may be a liquid other than the wire drawing lubricant.

[0055] (9) The function of one component in each of the above embodiments may be shared among 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. Furthermore, 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.

[0056] (10) In addition to the above-described method for manufacturing a rectangular enameled copper wire, the present disclosure can also be realized in various forms, such as a manufacturing apparatus for a rectangular enameled copper wire, a rectangular enameled copper wire, etc. (11) The flat enameled copper wire manufacturing apparatus 1 may use a vertical cassette roller die instead of the flat rolling mill 7 to produce the flat copper wire 23A. Furthermore, the flat copper wire 23A may be produced using a horizontal cassette roller die.

[0057] [Technical idea disclosed in this specification] [Item 1] Flat copper wire is continuously cold drawn using a flat wire drawing die to produce flat copper wire material. Applying enamel paint to the surface of the drawn rectangular copper wire material and baking it; A method for producing a rectangular enameled copper wire, comprising: copper powder removal treatment is performed to remove copper powder generated by the cold wire drawing process at the inlet and outlet sides of the flat wire drawing die. Manufacturing method for rectangular enameled copper wire. [Item 2] A method for producing the rectangular enameled copper wire according to item 1, The copper powder removal process is carried out with the flat wire drawing die attached to a flat enameled copper wire manufacturing device. Manufacturing method for rectangular enameled copper wire. [Item 3] Item 1 or 2. A method for producing a rectangular enameled copper wire, When the degree of occurrence of visual abnormalities in the produced rectangular enameled copper wire exceeds a predetermined standard, the copper powder removal treatment is carried out. Manufacturing method for rectangular enameled copper wire. [Item 4] A method for producing a rectangular enameled copper wire according to any one of items 1 to 3, The copper powder removal process is a process of injecting air or a wire drawing lubricant into the inlet and outlet sides of the flat wire drawing die. Manufacturing method for rectangular enameled copper wire. [Explanation of symbols]

[0058] 1...flat enameled copper wire manufacturing equipment, 3...dance ring or bobbin, 5...round wire drawing machine, 7...flat rolling mill, 9...annealing furnace, 11...flat wire drawing machine, 13...annealing furnace, 15...paint applicator, 17...baking furnace, 19...winder, 22A, 22B...short side, 23...conductor, 23A...flat copper wire, 23B...flat copper wire drawing material, 24A, 24B...side, 25...flat enameled copper wire, 26A, 26B...end face, 31...flat wire drawing die, 31A...inlet side, 31B...outlet side, 33...die holder, 35A, 35B, 35C, 35D...spray nozzle, 37...die presser, 39...processing hole, 41...cleaning member, 51...enamel granules, 53...open foam

Claims

1. Flat copper wire is continuously cold drawn using a flat wire drawing die to produce flat copper wire material. Applying enamel paint to the surface of the drawn rectangular copper wire material and baking it; A method for producing a rectangular enameled copper wire, comprising: copper powder removal treatment is performed to remove copper powder generated by the cold wire drawing process at the inlet and outlet sides of the flat wire drawing die. Manufacturing method for rectangular enameled copper wire.

2. A method for producing the rectangular enameled copper wire according to claim 1, The copper powder removal process is carried out with the flat wire drawing die attached to a flat enameled copper wire manufacturing device. Manufacturing method for rectangular enameled copper wire.

3. A method for producing a rectangular enameled copper wire according to claim 1 or 2, When the degree of occurrence of visual abnormalities in the produced rectangular enameled copper wire exceeds a predetermined standard, the copper powder removal treatment is carried out. Manufacturing method for rectangular enameled copper wire.

4. A method for producing a rectangular enameled copper wire according to claim 1 or 2, The copper powder removal process is a process of injecting air or a wire drawing lubricant into the inlet and outlet sides of the flat wire drawing die. Manufacturing method for rectangular enameled copper wire.

Images