JP2018056139A - Method of manufacturing enamel wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an enamel wire capable of forming a coated film good in appearance even when a solvent in an enamel wire coating is vaporized in short time and the enamel wire coating is dried.SOLUTION: There is provided a method of manufacturing an enamel wire having a process for irradiating a light having a wavelength which matches a peak wavelength of less than 4 μm in wavelengths absorbed by a solvent in an enamel wire coating applied to a conductor and vaporizing the solvent so that a curing reaction of a resin in the enamel wire coating is prevented.SELECTED DRAWING: Figure 3A

Description

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

  Enamelled wire is usually manufactured through a process of evaporating the solvent in the enameled wire paint applied to the conductor to dry the enameled wire paint and a step of curing the resin in the enameled wire paint and baking the film on the conductor. Is done. Conventionally, these steps have been performed in one apparatus.

  As a method of evaporating the solvent in the enamel wire paint and drying the enamel wire paint, a method of heating with hot air, induction heating, infrared rays or the like is known (for example, see Patent Document 1).

JP2012-252868 (paragraph [0052])

  However, according to the conventional method, when a film is formed on the outer periphery of the conductor in a short time, a waveform is generated on the surface of the dried enamel wire paint, or only the surface of the enamel wire paint is dried (so-called skin coating). ) And the solvent remains without evaporating, and foaming due to the remaining solvent occurs in the film. Therefore, in order to form a film having a good appearance on the outer periphery of the conductor, it is necessary to take time to evaporate the solvent in the enamel wire paint and dry it.

  Accordingly, an object of the present invention is to provide an enameled wire manufacturing method and apparatus capable of forming a film having a good appearance even when the solvent in the enameled wire paint is evaporated in a short time and the enameled wire paint is dried. There is to do.

  In order to achieve the above object, the present invention provides the following enameled wire manufacturing method.

[1] The solvent so as not to cure the resin in the enamel wire paint by applying light having a wavelength that matches a peak wavelength of less than 4 μm among wavelengths absorbed by the solvent in the enamel wire paint applied to the conductor. The manufacturing method of an enameled wire which has the process of evaporating.

  ADVANTAGE OF THE INVENTION According to this invention, even if the solvent in an enamel wire paint is evaporated in a short time and an enamel wire paint is dried, the manufacturing method of the enamel wire which can form a favorable external appearance can be provided.

It is the schematic which shows an example of the manufacturing apparatus of the enamel wire which concerns on embodiment of this invention. It is a top view which shows the principal part of the manufacturing apparatus of FIG. It is the schematic (sectional drawing perpendicular | vertical to a conductor advancing direction) which shows one Embodiment of the evaporation furnace of FIG. It is the schematic (side view parallel to a conductor advancing direction) which shows the evaporation furnace (part) of FIG. 3A. It is the schematic (sectional drawing perpendicular | vertical to a conductor advancing direction) which shows another one Embodiment of the evaporation furnace of FIG. It is the schematic (sectional drawing parallel to a conductor advancing direction) which shows the evaporation furnace of FIG. 4A.

[Method for producing enameled wire]
In the enameled wire manufacturing method according to the embodiment of the present invention, the solvent in the enameled wire coating applied to the conductor is irradiated with light having a wavelength that matches a peak wavelength of less than 4 μm among wavelengths absorbed by the solvent. It has the process of evaporating by.

  FIG. 1 is a schematic view showing an example of an enameled wire manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a top view showing a main part of the manufacturing apparatus of FIG.

  As shown in FIG. 1, the conductor 1 is supplied to an annealing furnace 12 through a pulley 11 and annealing is performed. Annealing can be omitted if not necessary. Thereafter, the conductor 1 travels to the paint application unit 14 via the turn pulley 13 and the enamel wire paint is applied to the outer periphery of the conductor 1.

  The conductor 1 to which the enamel wire paint is applied travels in the evaporation furnace 15 and the curing furnace 16 constituting the baking furnace 10, and evaporates the solvent in the enamel wire paint (that is, the enamel wire paint is dried) and in the enamel wire paint. The resin is cured (that is, the film is baked).

  As shown in FIG. 2, the enamel wire 2 returns to the upstream turn pulley 13 via the downstream turn pulley 13, the application of the enamel wire paint, the evaporation of the solvent in the enamel wire paint, and the resin in the enamel wire paint. Is repeated until the desired film thickness is obtained.

  The method for curing the resin in the enamel wire paint is not particularly limited, and can be performed by heating with hot air or the like.

  On the other hand, the evaporation of the solvent in the enamel wire paint matches the peak wavelength of less than 4 μm out of the wavelengths absorbed by the solvent in the enamel wire paint applied to the conductor 1 in the evaporation furnace 15 as described above. It is performed by evaporating by applying light having a wavelength to be applied.

  The peak wavelength is preferably in the range of 2.0 to 3.2 μm, more preferably in the range of 2.2 to 3.1 μm, and in the range of 2.3 to 3.0 μm. More preferably.

  The light applied to the conductor 1 coated with the enamel wire paint is preferably light having a peak wavelength that matches the peak wavelength, and more preferably light having no other peak wavelength. Resin that is a solute has no absorption, and by applying light that is absorbed only to the solvent that is the solvent, the surface of the enamel wire paint is suppressed and the workability is improved. The surface of the enamel wire paint applied to the conductor is partly due to the curing reaction such as the crosslinking reaction of the resin, but by irradiating light of a wavelength that only the solvent absorbs so as not to heat the resin, Resin curing reaction can be suppressed, and skinning can be suppressed. Moreover, a solvent can be efficiently dried at low temperature by irradiating the light of the wavelength which only a solvent absorbs. For this reason, unlike the conventional case, when drying in a short time, there is no need to increase the drying temperature, and foaming caused by boiling and bumping of the solvent can be suppressed (the risk of foaming is reduced). The appearance of the film formed on the outer periphery of the film becomes good.

  For example, when N, N-dimethylacetamide (DMAc) is used as a solvent in an enameled wire paint (for example, polyimide paint), N, N-dimethylacetamide (DMAc) has wavelengths of 2.3 μm and 3.0 μm at less than 4 μm. It is preferable to irradiate light having a peak wavelength around 2.3 μm (2.3 ± 0.2 μm) or around 3.0 μm (3.0 ± 0.2 μm). It is more preferable to irradiate light having a peak wavelength at 2.3 μm or 3.0 μm, and it is more preferable to irradiate light having no other peak wavelength. At this time, since the polyamic acid dissolved in the paint (which becomes a polyimide after curing) has an absorption of only 3.3 μm or more, the ring closure reaction of the polyamic acid can be suppressed by selecting light having the above peak wavelength. Therefore, it is possible to make the surface of the enamel wire paint difficult to skin.

  Hereinafter, a specific example will be described.

  3A is a schematic diagram (cross-sectional view perpendicular to the conductor traveling direction) showing one embodiment of the evaporation furnace of FIG. 1, and FIG. 3B is a schematic diagram (partial) of the evaporation furnace (part) of FIG. 3A. Side view parallel to the direction).

  A near-infrared heater 151 and a light collector 152 are installed in an evaporation furnace 150 that is one embodiment of the evaporation furnace, and a near-infrared heater is provided to the conductor 1 or the enamel wire 2 that runs through the furnace opening 153 of the evaporation furnace 150. The near-infrared light from 151 can be condensed by the light collector 152 and irradiated with the irradiation light 151A.

  4A is a schematic diagram showing another embodiment of the evaporation furnace of FIG. 1 (cross-sectional view perpendicular to the conductor traveling direction), and FIG. 4B is a schematic diagram showing the evaporation furnace of FIG. 4A (conductor progressing). It is sectional drawing parallel to a direction).

  A laser irradiation unit 251 is installed in an evaporation furnace 250, which is another embodiment of the evaporation furnace, and the laser irradiation unit 251 is connected to the conductor 1 or the enamel wire 2 that runs through the furnace opening 252 of the evaporation furnace 250. The laser beam (irradiation light 251A) can be applied.

  The light source for irradiating the wavelength that matches the peak wavelength of less than 4 μm out of the wavelengths absorbed by the solvent in the enamel wire paint is not limited to the near infrared heater and the semiconductor laser light. For example, it may be an LED (light emitting diode), a high-intensity discharge lamp, or an EL (electroluminescence) light.

  Near-infrared rays are irradiated not only with the near-infrared heater 151 but also with a wavelength control heater that generates infrared rays with a quartz tube and a tungsten filament, and can irradiate only near-infrared rays by cutting the far-infrared region by cooling. You can also.

  As the laser irradiation unit 251, for example, a semiconductor laser irradiation unit is suitable.

  A plurality of (for example, twelve) near infrared heaters 151 and laser irradiation units 251 are arranged in a direction perpendicular to the traveling direction of the conductor. Further, the near infrared heater 151 is 50 to 800 cm at a position facing each other so as to sandwich the traveling conductor in a direction parallel to the conductor traveling direction (up and down of the traveling conductor in FIGS. 3A and 3B). The laser irradiation unit 251 is provided at a position facing each other so as to sandwich the traveling conductor in a direction parallel to the traveling direction of the conductor (in FIG. 4A and FIG. 4B, ) Are arranged in plural (for example, two). The length and the number of installed near infrared heaters 151 and the number of installed laser irradiation units 251 may be set as appropriate, and are not limited thereto.

  The enameled wire 2 that has been baked is wound around the winder 17.

  The material of the conductor 1 used in the present embodiment can be used without any particular limitation, such as copper or copper alloy. In addition, examples of the shape of the conductor 1 include a round wire, a rectangular conductor, and the like. In the case of a rectangular conductor, there is an advantage over the conventional method.

  When applied to a flat enameled wire, the conventional method has a slow drying speed and cannot be dried in a short time, so that the coating film (enameled wire paint applied to the flat conductor) flows before drying. Since the enameled wire paint applied to the corners of the flat conductor flows to the periphery of the corners, the coating of the coating becomes worse. That is, the thickness of the film was not uniform. On the other hand, according to the method according to the embodiment of the present invention, since it can be dried in a short time (and at a low temperature in a preferred embodiment), it can be dried in a state where the coating film is prevented from flowing. For this reason, it can suppress that the surroundings of a film worsen. Thus, in the embodiment of the present invention, since the drying speed can be increased, the coating film is less likely to sag, and a thick line or a rectangular line having a good coating state can be manufactured.

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

[Enamel wire manufacturing equipment]
An enameled wire manufacturing apparatus according to an embodiment of the present invention includes a baking furnace provided with an irradiation device for irradiating a traveling conductor coated with an enameled wire paint with light having a peak wavelength of less than 4 μm. To do.

  A specific configuration example of the enameled wire manufacturing apparatus is as shown in FIGS. 1 to 4, and is the same as the baking furnace 10 and the winder 17 described above.

  In the present embodiment, the baking furnace 10 including the separate evaporation furnace 15 and the curing furnace 16 is provided, and the irradiation apparatus is provided in the evaporation furnace 15. However, as the baking furnace in which the evaporation furnace 15 and the curing furnace 16 are integrated. Alternatively, the irradiation device may be provided on the upstream side (conductor inlet side) of the baking furnace. In terms of making it difficult to be affected by the curing process (hot air or the like) in the curing furnace 16, it is preferable to separate the evaporation furnace 15 and the curing furnace 16 as in the present embodiment. Thereby, a film with a better appearance can be formed.

  In the present embodiment, the baking furnace is a horizontal furnace, but it may be a vertical furnace as disclosed in Patent Document 1 described above.

[Effect of the embodiment of the present invention]
According to an embodiment of the present invention, an enameled wire manufacturing method and a manufacturing apparatus capable of forming a film having a good appearance even when the solvent in the enameled wire paint is evaporated in a short time to dry the enameled wire paint Can be provided. That is, the enameled wire paint can be dried by evaporating the solvent in a short time compared with the case of drying the enameled wire paint using hot air or the like, so that the production speed of the enameled wire can be increased and the production cost can be reduced. . In addition, since the baking furnace can be shortened, it is possible to save the space for installing the manufacturing apparatus. In addition, the solvent is volatilized by vibrating the solvent molecules, allowing the solvent to evaporate uniformly and drying the enamel wire paint, thereby suppressing foaming and skinning compared to when heat is used. it can.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible. For example, hot air (preferably low temperature and low wind speed) can be used in combination in the evaporation furnace 15 as long as the effects of the present invention are exhibited.

DESCRIPTION OF SYMBOLS 1: Conductor, 2: Enamel wire 10: Baking furnace, 11: Pulley, 12: Annealing furnace, 13: Turn pulley 14: Paint application part, 15: Evaporating furnace, 16: Curing furnace, 17: Winding machine 150: Evaporating furnace , 151: near infrared heater, 151A: irradiation light 152: light collector, 153: furnace opening 250: evaporating furnace, 251: laser irradiation unit, 251A: irradiation light 252: furnace opening

Claims (1)

  The solvent is evaporated so that the resin in the enamel wire paint does not undergo a curing reaction by applying light having a wavelength that matches a peak wavelength of less than 4 μm among wavelengths absorbed by the solvent in the enamel wire paint applied to the conductor. The manufacturing method of an enameled wire which has a process.