Enameled copper wire manufacturing device and enameled copper wire manufacturing method

Abstract

The invention provides a manufacturing device of an enameled copper wire and a manufacturing method of the enameled copper wire, which can restrain generation of abnormal appearance parts. A device for manufacturing an enameled copper wire is provided with a coating material application unit configured so as to apply a coating material to the surface of a moving conductor, and a sintering unit configured so as to sinter the conductor to which the coating material is applied. The manufacturing device for the enameled copper wire is further provided with a dehumidification unit which is configured so that the absolute humidity of the space in which the manufacturing device is provided is 18 g / m < 3 > or less.

Description

Technical Field

[0001] This disclosure relates to an apparatus for manufacturing enameled copper wire and a method for manufacturing enameled copper wire. Background Technology

[0002] Enameled copper wire comprises a conductor and an enameled coating. The conductor is primarily composed of copper. The enameled coating covers the surface of the conductor. Patent Document 1 describes a method for manufacturing enameled copper wire. In this method, an enameled coating is applied to the surface of the conductor to form a coating film. Then, the enameled coating is formed by sintering.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-3913 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Sometimes, the manufactured enameled copper wires exhibit appearance defects. In one aspect of this disclosure, an apparatus and a method for manufacturing enameled copper wires are preferably provided that can suppress the generation of appearance defects.

[0008] Methods for solving problems

[0009] One aspect of this disclosure is an apparatus for manufacturing enameled copper wire, comprising a coating section and a sintering section. The coating section is configured to apply a coating to the surface of a traveling conductor, and the sintering section is configured to sinter the conductor coated with the coating. The apparatus further comprises a dehumidification section configured to maintain an absolute humidity of 18 g / m³ in the space where the apparatus is located. 3 The following is an aspect of the apparatus for manufacturing enameled copper wire that can suppress the occurrence of appearance abnormalities in the manufactured enameled copper wire.

[0010] Another aspect of this disclosure is a method for manufacturing enameled copper wire, which involves coating the surface of a traveling conductor with a coating and sintering the conductor coated with the coating, wherein the absolute humidity of the space in which the method for manufacturing enameled copper wire is carried out is 18 g / m². 3 The following is another aspect of the manufacturing method for enameled copper wire disclosed herein, which can suppress the occurrence of appearance abnormalities in the manufactured enameled copper wire. Attached Figure Description

[0011] Figure 1 This is an explanatory diagram showing the structure of a manufacturing apparatus for flat enameled copper wire.

[0012] Figure 2It is a cross-sectional view showing the cross-sectional shape of a flat copper wire.

[0013] Figure 3 It is a cross-sectional view showing the cross-sectional shape of flat copper wire.

[0014] Figure 4 This is a schematic diagram illustrating the mechanism by which abnormal appearances are generated.

[0015] Figure 5 It is a chart showing the relationship between the temperature and relative humidity of a space and the ease with which abnormalities occur in the appearance of the space.

[0016] In Figure 6, Figure 6A This is an explanatory diagram showing a single, isolated abnormality in appearance. Figure 6B This is an explanatory diagram representing a continuous abnormal region.

[0017] Figure 7 It is a chart showing the relationship between the absolute humidity of the space and the proportion of non-inhibitory products in the appearance abnormalities.

[0018] Explanation of reference numerals in the attached figures

[0019] 1… Manufacturing apparatus for flat enameled copper wire, 3… Flywheel or winding assembly, 5… Circular wire drawing machine, 7… Flat rolling mill, 9… Annealing furnace, 11… Flat wire drawing machine, 13… Annealing furnace, 15… Coating machine, 17… Sintering furnace, 19… Winding machine, 20… Dehumidifier, 22A, 22B… Short side, 23… Conductor, 23A… Flat copper wire, 23B… Flat copper wire drawing material, 24A, 24B… Edge, 25… Flat enameled copper wire, 26A, 26B… End face, 31… Space, 33… Enameled coating, 35… Coating film, 39… High viscosity layer, 51… Appearance abnormality section, 53… Continuous abnormality section. Detailed Implementation

[0020] The exemplary embodiments of this disclosure will be described with reference to the accompanying drawings.

[0021] <First Implementation Method>

[0022] 1. Composition of the manufacturing apparatus and method for flat enameled copper wire

[0023] based on Figures 1-3 The manufacturing method of flat enameled copper wire is described. In the manufacturing method of flat enameled copper wire, the following steps are used: Figure 1The apparatus 1 shown is for manufacturing flat enameled copper wire. The apparatus 1 includes a flywheel or winding assembly 3, a circular wire drawing machine 5, a flat rolling mill 7, an annealing furnace 9, a flat wire drawing machine 11, an annealing furnace 13, a coating machine 15, a sintering furnace 17, a winding machine 19, and a dehumidifier 20. The dehumidifier 20 corresponds to the dehumidification section. The coating machine 15 corresponds to the coating section. The sintering furnace 17 corresponds to the sintering section. The flat enameled copper wire manufacturing apparatus 1 is a horizontal production line extending in the horizontal direction.

[0024] A wire conductor 23 is wound on a flywheel or winding assembly 3. The conductor 23 is pulled out from the flywheel or winding assembly 3 and travels along a path that passes sequentially through a circular wire drawing machine 5, a flat rolling mill 7, an annealing furnace 9, a flat wire drawing machine 11, an annealing furnace 13, a coating machine 15, and a sintering furnace 17, and is wound on a winding machine 19. The flat copper wire 23B, which is the processed conductor 23, passes through the area including the coating machine 15 and the sintering furnace 17 multiple times.

[0025] The conductor 23 is made of copper or a copper alloy. The cross-sectional shape of the conductor 23 is circular before the flat rolling process described later. It should be noted that the cross-section of the conductor 23 refers to the section orthogonal to the length direction of the conductor 23.

[0026] The circular wire drawing machine 5 draws the conductor 23, which has a circular cross-sectional shape, into wires. The flat rolling machine 7 flattens the traveling conductor 23. The flattened conductor 23 is designated as flat copper wire 23A. Figure 2 As shown, the cross-sectional shape of the flat copper wire 23A is formed by two parallel sides 24A and 24B and two arc-shaped end faces 26A and 26B. In the cross-section, sides 24A and 24B are straight lines. The lengths of sides 24A and 24B in the cross-section are greater than the lengths of end faces 26A and 26B. The flat copper wire 23A is annealed in the annealing furnace 9.

[0027] The flat wire drawing machine 11 performs flat wire drawing on the moving flat copper wire 23A. Flat wire drawing is a process of continuously cold drawing flat copper wire 23A using a flat wire drawing die. The conductor 23 that has undergone flat wire drawing is used as flat copper wire material 23B.

[0028] The cross-sectional shape of flat copper wire 23B is as follows: Figure 3 As shown, this is a rounded rectangle. The longer sides of the rounded rectangle are sides 24A and 24B. The shorter sides 22A and 22B of the rounded rectangle are derived from the end faces 26A and 26B in the flat copper wire 23A.

[0029] like Figure 1As shown, in the flat wire drawing machine 11, the direction of travel of the conductor 23 is designated as the travel direction TR. The opposite direction of the travel direction TR is designated as the upstream direction US. The annealing furnace 13 anneals the flat copper wire 23B. The coating machine 15 forms a coating film of predetermined thickness on the surface of the flat copper wire 23B by applying an enameled coating to the surface of the flat copper wire 23B. The linear speed of the flat copper wire 23B when the coating machine 15 applies the enameled coating is preferably 14 m / min or more, and more preferably 20 m / min or more.

[0030] The sintering furnace 17 heats the traveling flat copper wire 23B, on which a coating of a predetermined thickness has been formed using a coating machine 15, to sinter and form the enameled film. Figure 1 As shown, the process of applying enameled coating using a coating machine 15 and forming an enameled film using a sintering furnace 17 is repeated. For example, the coating and sintering process is repeated 40 times. As a result, a flat enameled copper wire 25 with a predetermined film thickness is produced. The flat enameled copper wire 25 is wound on a winding machine 19.

[0031] The method for forming the enameled coating is described below. An enameled coating is applied to the surface of the flat copper wire 23B. The enameled coating is, for example, a coating containing resin and solvent. Next, the solvent in the enameled coating applied to the surface of the flat copper wire 23B is evaporated, and the resin in the enameled coating is cured. After solvent evaporation and resin curing, a flat enameled copper wire 25 is formed. The flat enameled copper wire 25 corresponds to the enameled copper wire.

[0032] The dehumidifier 20 dehumidifies the space 31 where the manufacturing apparatus 1 is located, reducing the absolute humidity in the space 31. Space 31 is the space where the manufacturing of flat enameled copper wires 25 is carried out. The dehumidifier 20 maintains the absolute humidity of space 31 at 18 g / m³. 3 For example, a control unit (not shown) or operator controls the dehumidifier 20 based on the measured absolute humidity in space 31 to make the absolute humidity of space 31 18 g / m³. 3 The higher the absolute humidity of space 31, the stronger the dehumidification capacity of dehumidifier 20.

[0033] 2. The effect of the manufacturing apparatus 1 and manufacturing method for flat enameled copper wire

[0034] The manufacturing apparatus 1 and manufacturing method for flat enameled copper wire can suppress the generation of appearance abnormalities 51 in the flat enameled copper wire 25. The reason for this is speculated as follows. Figure 4S1 indicates a state where an enameled film 33 is formed on the flat copper wire drawing 23B, and a coating film 35 is formed thereon. The enameled film 33 is a film formed by applying an enameled coating and sintering it. The coating film 35 is a film formed by applying an enameled coating. The coating film 35 is a film containing a large amount of solvent and has not yet cured. During the period when the enameled coating remains in the tank of the coating machine 15, the enameled coating absorbs moisture from its surface. When the absolute humidity increases, there are localized areas 37 with high moisture content in the coating film 35.

[0035] S2 is the state after S1 where the coating film 35 is heated. When the absolute humidity of the space is high, a high-viscosity layer 39 is formed on the surface of the coating film 35. The high-viscosity layer 39 is the part of the coating film 35 that absorbs moisture from the space 31 and becomes more viscous. The water and solvent contained in the part 37 with more moisture cannot evaporate due to the presence of the high-viscosity layer 39. As a result, foaming occurs in the part 37 with more moisture, creating an appearance defect 51. S3 is the state after S2 where the coating film 35 with the appearance defect 51 becomes an enameled film 33, and an enameled film 33 is further laminated on top of it.

[0036] The apparatus and method for manufacturing flat enameled copper wires set the absolute humidity of space 31 to 18 g / m³. 3 Therefore, it is not easy to form a high-viscosity layer 39. Consequently, the moisture in the high-moisture portion 37 evaporates easily, making foaming difficult. As a result, it is difficult to produce the appearance abnormality portion 51.

[0037] <Example 1>

[0038] While varying the temperature and relative humidity of the space 31, flat enameled copper wire 25 is manufactured using the manufacturing apparatus 1. The manufacturing conditions are kept constant except for the temperature and relative humidity of the space 31. An appearance abnormality 51 is detected in the manufactured flat enameled copper wire 25. Figure 5 This indicates the relationship between the temperature and relative humidity of space 31 and the ease with which appearance abnormalities occur in part 51.

[0039] Figure 5 The horizontal axis represents temperature. Figure 5 The vertical axis represents relative humidity. Figure 5 On the boundary line L shown, the absolute humidity of space 31 is 18 g / m³. 3 . Figure 5 The area X shown is space 31 with an absolute humidity of 18 g / m³. 3 The following areas. Figure 5 The area Y shown is where the absolute humidity of space 31 exceeds 18 g / m³. 3In region X, the flat enameled copper wire 25 is less likely to produce appearance defects 51. In region Y, the flat enameled copper wire 25 is more likely to produce appearance defects 51. Based on this result, it can be confirmed that if the absolute humidity of space 31 is 18 g / m³, the appearance defects 51 are more likely to occur. 3 The following flat enameled copper wire 25 is less likely to produce appearance abnormalities 51.

[0040] <Example 2>

[0041] 1. Manufacturing of flat enameled copper wire 25

[0042] While varying the absolute humidity of space 31, flat enameled copper wire 25 was manufactured using manufacturing apparatus 1. The manufacturing conditions were kept constant except for the absolute humidity of space 31. The manufacturing conditions are as follows.

[0043] The cross-sectional dimensions of flat copper wire 23B are as follows: the lengths of edges 24A and 24B are 3mm. The lengths of edges 22A and 22B are 2mm.

[0044] The composition of enameled coatings: Coatings composed of imide-based polymers and solvents. Examples of imide-based polymers include polyimides, polyamic acids, polyamide-imides, and polyesterimides. Examples of solvents include N-methyl-2-pyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide, but are not limited to these. Furthermore, other solvents and additives may also be mixed in.

[0045] The linear speed of the flat copper wire 23B when applying enameled coating on the coating machine 15 is 20 m / min.

[0046] The coating thickness of the enameled coating in a single coating pass is 4 μm.

[0047] The sintering temperature in sintering furnace 17 is 700–750℃.

[0048] Number of times the enameled coating is applied: 40 times

[0049] Total film thickness of enameled coating: 160μm

[0050] 2: Evaluation of Flat Enameled Copper Wire 25

[0051] In the manufactured flat enameled copper wire 25, the number of appearance defects 51 is counted. The method for counting the number of appearance defects 51 is as follows. First, the surface of the flat enameled copper wire 25 is photographed with a camera. In the image from the camera, as shown... Figure 6AAs shown, if one appearance abnormality 51 exists sufficiently far away from other appearance abnormalities 51, it is determined that one appearance abnormality 51 exists. For example, if only one appearance abnormality 51 exists within the field of view of the camera image, it is determined that one appearance abnormality 51 exists.

[0052] like Figure 6B As shown, when multiple appearance abnormalities 51 are arranged along one direction D and satisfy both of the following conditions J1 and J2, it is determined that the multiple appearance abnormalities 51 are a continuous abnormality 53.

[0053] (J1) Width W is 0.5mm or more.

[0054] (J2) The aspect ratio A is 4 or higher.

[0055] It should be noted that the width W refers to the overall width of the plurality of appearance anomalies 51 in a direction orthogonal to 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 appearance anomalies 51 in direction D.

[0056] If there is one continuous abnormal part 53, it is determined that there are n appearance abnormal parts 51 as shown in the following formula (1).

[0057] Equation (1) n=f(P / P0)

[0058] 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 photographing the surface of the flat enameled copper wire 25 with a camera. In equation (1), f(P / P0) is the smallest integer greater than P / P0. For example, when P / P0 is 0.5, f(P / P0) is 1. For example, when P / P0 is 1.5, f(P / P0) is 2.

[0059] Based on the number of appearance defects 51, the manufactured flat enameled copper wires 25 are classified into appearance defect-suppressed products and appearance defect-non-suppressed products. Appearance defect-suppressed products are flat enameled copper wires 25 with fewer than 30 appearance defects 51 per 3200m. Appearance defect-non-suppressed products are flat enameled copper wires 25 with 30 or more appearance defects 51 per 3200m.

[0060] Next, for each absolute humidity value in space 31, the proportion of non-suppressed products with appearance abnormalities was calculated. The results are shown below. Figure 7 . Figure 7 The horizontal axis represents absolute humidity. The vertical axis represents the proportion of non-inhibited products with abnormal appearance. It should be noted that the absolute humidity of space 31 was measured separately in the flywheel or winding assembly 3 and the coating machine 15. Figure 7 The absolute humidity of the two locations is shown in the figure.

[0061] like Figure 7 As shown, the absolute humidity in space 31 is 18 g / m². 3 In the following cases, with a concentration exceeding 18g / m 3 Compared to the previous situation, the proportion of non-inhibitory products in areas with abnormal appearance was significantly lower.

[0062] <Other Implementation Methods>

[0063] The embodiments of this disclosure have been described above, but this disclosure is not limited to the above embodiments and can be implemented in various ways.

[0064] (1) The enameled copper wire manufacturing apparatus 1 can manufacture enameled copper wires other than flat enameled copper wires, for example, it can manufacture round enameled copper wires.

[0065] (2) Alternatively, multiple constituent elements may share the functions of one constituent element in each of the above embodiments, or one constituent element may perform the functions of multiple constituent elements. Furthermore, a portion of the configuration in each of the above embodiments may be omitted. Additionally, at least a portion of the configuration in each of the above embodiments may be added to, substituted for, or otherwise modified relative to the configurations of other embodiments.

[0066] (3) In addition to the above-mentioned flat enameled copper wire manufacturing apparatus 1, this disclosure can also be implemented in various ways, such as a system equipped with flat enameled copper wire manufacturing apparatus 1 and a method for controlling absolute humidity.

Claims

1. An apparatus for manufacturing an enameled copper wire, comprising: a coating material applying section configured to apply a coating material to a surface of a conductor that is advancing; and a sintering section configured to sinter the conductor to which the coating material is applied; wherein a wire speed of the conductor at the time when the coating material applying section applies the coating material is 14 m / min or more.

3. A method for manufacturing an enameled copper wire, comprising: applying a coating material to a surface of a conductor that is advancing; and sintering the conductor to which the coating material is applied; wherein a wire speed of the conductor at the time when the coating material is applied is 14 m / min or more. ​ The manufacturing device of the enameled copper wire further has a dehumidification section configured to set the absolute humidity of a space in which the manufacturing device is provided to 18 g / m 3 The following.

2. The apparatus for manufacturing the enameled copper wire according to claim 1, wherein ​ ​ wherein The absolute humidity of the space in which the enameled copper wire manufacturing method is implemented is set to 18 g / m 3 The following.

4. The enameled copper wire manufacturing method according to claim 3, wherein ​

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