JP2010277988A - Manufacturing method of insulated wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an insulated wire wherein uneven thickness of a formed insulating layer is prevented, there is no need for complex replacement work, in order to replace a coating dice to one different in a diameter of an opening section, loss of insulating coating due to cleaning of a liquid tank for changing the insulating coating is prevented, and the manufacturing cost of the insulated wire is reduced. <P>SOLUTION: In the insulated wire which has a conductor and an insulating layer to cover the conductor, after the liquid insulating coating is made into fine droplets and sprayed and adhered to the conductor directly or via other layers, the insulating layer is formed by carrying out baking of the insulating coating. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an insulated wire. More specifically, the present invention relates to a method of manufacturing an insulated wire that eliminates the use of a liquid tank and a coating die for attaching an insulating paint to a conductor when the insulated wire is manufactured.

  As a method for producing an insulated wire, a method for producing an insulated wire by immersing the conductor in a liquid tank filled with an insulating paint to adhere the insulating paint to the surface of the conductor and then baking it has been proposed (for example, , See Patent Document 1). More specifically, in this method, as shown in FIG. 2, the conductor 12 is run in the direction of arrow A in the liquid tank 11 filled with the insulating paint 13, and the conductor 12 is immersed in the insulating paint 13 by immersion. The conductor 12 to which the insulating paint 13 is attached is inserted through the opening of the coating die 14 to remove the excess insulating paint 13 attached to the outer periphery of the conductor 12 and then baked in a baking furnace 15 to insulate the insulated wire. It is a method of manufacturing.

JP 2008-123759 A

  However, since the method shown in FIG. 2 requires a coating die 14, when the conductor 12 inserted through the opening of the coating die 14 is caused to travel, the conductor 12 may be deflected to cause an insulating layer to be formed. May cause meat. Further, in this method, when the conductor 12 to which the insulating paint 13 is attached is changed to a conductor 12 having a diameter different from that, or when the thickness of the insulating layer formed on the conductor surface is changed, the coating die 14 is applied. Must be replaced with one having a different diameter of the opening, which makes the replacement work complicated and causes loss of the insulating paint.

  The present invention has been made in view of the above-described prior art, and requires a complicated replacement work for preventing uneven thickness of the insulating layer to be formed and replacing the coating die with one having a different opening diameter. However, it is an object of the present invention to provide a method of manufacturing an insulated wire that prevents the loss of the insulating paint due to washing of the liquid tank for changing the insulating paint and reduces the manufacturing cost of the insulated wire.

  The method for producing an insulated wire according to the present invention is a method for producing an insulated wire having a conductor and an insulating layer covering the conductor, and the liquid insulating paint is atomized and sprayed to directly or other layers on the conductor. Then, the insulating paint is baked to form an insulating layer.

  Since the insulated wire manufacturing method of the present invention does not require a coating die as in the prior art, when the conductor inserted through the opening of the coating die is caused to travel, the conductor is deflected and the insulating layer formed is biased. The production of meat can be avoided. Furthermore, since the manufacturing method of the insulated wire of the present invention does not require a coating die, the insulating layer formed on the conductor surface when the conductor to which the insulating paint is attached is changed to a conductor having a diameter different from that of the conductor. When the thickness of the coating is changed, a complicated replacement work of replacing the coating die with one having a different diameter of the opening as in the prior art becomes unnecessary. Moreover, in the method for manufacturing an insulated wire according to the present invention, when another type of insulated wire is manufactured, work for cleaning the liquid tank and changing the die for changing the insulating paint is not required.

  In the method for producing an insulated wire of the present invention, when the insulating paint is sprayed on the surface of the conductor using an ink jet head, the insulating paint can be sprayed within a narrow range, so that the scattering of the insulating paint is prevented, Insulating paint can be appropriately applied to a predetermined position of the conductor by spraying at a high uniform and high speed.

  In the method for manufacturing an insulated wire according to the present invention, when a two-component insulating paint is used as an insulating paint, the storage stability of the insulating paint can be improved, and the two liquids are mixed immediately before spraying the insulating paint. And after making it adhere to the surface of a conductor by spraying an insulating paint, the baking time when baking an insulating paint can be aimed at. As the two-component insulating coating, for example, a resin and its curing agent can be used.

  In the method for manufacturing an insulated wire according to the present invention, when a plurality of spray nozzles are disposed around a conductor and the insulating paint is sprayed from the spray nozzle and adhered to the surface of the conductor, the insulating paint is sprayed. It can be uniformly attached to the conductor.

  In the method for manufacturing an insulated wire according to the present invention, when the operation consisting of spraying the insulating paint to adhere to the surface of the conductor, baking the insulating paint, and forming the insulating layer is repeated. As a result, the insulating paint can be more uniformly adhered to the conductor, the generation of pinholes can be suppressed, and an insulating layer having excellent withstand voltage characteristics can be formed.

  In the method for producing an insulated wire of the present invention, when the insulating coating is diluted with a supercritical fluid, the supercritical fluid is used, and therefore it is necessary to use a flammable or toxic organic solvent. Therefore, the influence on the environment can be reduced.

  In the method for producing an insulated wire according to the present invention, when the supercritical fluid is supercritical carbon dioxide, the supercritical carbon dioxide vaporizes and scatters at a temperature below the critical point, and therefore easily comprises an insulating paint. An insulating layer can be formed.

  According to the method for manufacturing an insulated wire of the present invention, the insulating layer to be formed is prevented from being unevenly thickened, and it is not necessary to perform a complicated replacement work for replacing the coating die with one having a different opening diameter. Loss of the insulating paint due to washing of the liquid tank for changing the paint can be prevented, and the manufacturing cost of the insulated wire can be reduced.

It is a schematic explanatory drawing which shows one embodiment of the manufacturing method of the insulated wire of this invention. It is a schematic explanatory drawing which shows one embodiment of the manufacturing method of the conventional insulated wire.

  As described above, the method for producing an insulated wire according to the present invention is a method for producing an insulated wire having a conductor and an insulating layer covering the conductor, in which a liquid insulating paint is atomized and sprayed directly on the conductor. Or after making it adhere through another layer, baking of an insulating paint is performed and an insulating layer is formed.

  There is no limitation in particular as a conductor, For example, a copper wire etc. are mentioned. The diameter of the conductor (conductor diameter) is preferably 0.02 mm or more from the viewpoint of securing the strength of the insulated wire. The upper limit value of the diameter of the conductor (conductor diameter) is not particularly limited, and may be appropriately determined according to the use of the insulated wire, but is about 4 mm for a general insulated wire. Further, the shape of the conductor is not particularly limited, and examples thereof include a round wire, a flat wire, and a polygonal line.

  Examples of the insulating paint include an insulating paint obtained by dissolving an insulating resin in a solvent, an insulating paint obtained by heating and melting an insulating resin, and a two-component insulating paint made of a resin and its curing agent. Can be mentioned. Among these insulating coatings, a two-pack type insulating coating composed of a resin and its curing agent is prepared by mixing the resin and its curing agent immediately before spraying the insulating coating and spraying the obtained insulating coating. Thus, when the insulating paint is baked after being attached to the surface of the conductor, the baking temperature can be lowered and the baking time can be shortened.

  Examples of the resin include polyurethane, polyesterimide, polyamideimide, polyimide, polyvinyl chloride, polyethylene, polyamide, and polyester.

  Polyurethane includes polyester-based polyurethane and polyether-based polyurethane. The polyester-based polyurethane can be obtained, for example, by polyaddition reaction of adipate obtained by polycondensation of adipic acid and polyhydric alcohol and diisocyanate. The polyether-based polyurethane can be obtained, for example, by reacting a difunctional polyether such as poly (oxypropylene) glycol (PPG) or poly (oxytetramethylene) glycol (PTMG) with a diisocyanate.

  When using polyurethane as the resin having insulating properties, from the viewpoint of lowering the baking temperature and shortening the baking time, a bifunctional polyether and diisocyanate are mixed and mixed immediately before spraying the insulating coating onto the conductor. It is preferable to spray the conductor while preparing the insulating coating by reacting the obtained mixture.

  Polyesterimide can be obtained, for example, by reacting imidodicarboxylic acid, which is a reaction product of tricarboxylic acid anhydride and diamine, with polyhydric alcohol.

  Examples of the solvent used in the insulating paint in which an insulating resin is dissolved in a solvent include a supercritical fluid and an organic solvent.

  A supercritical fluid means a substance at a temperature and pressure above the critical temperature, and has gas diffusivity and liquid solubility properties. The supercritical fluid has an advantage that the influence on the environment can be reduced since it is not necessary to use a flammable or toxic organic solvent. Examples of the supercritical fluid include supercritical carbon dioxide, supercritical water, supercritical methane, supercritical ethane, supercritical propane, supercritical methanol, supercritical ethanol, and supercritical acetone. It is not limited only to such illustration. Among these supercritical fluids, supercritical carbon dioxide vaporizes and scatters at a temperature below the critical point, and thus has an advantage that an insulating layer made of an insulating coating can be easily formed. The amount of supercritical fluid is preferably adjusted so that the insulating coating has a desired viscosity when it is deposited on the surface of the conductor. The scattered supercritical fluid can be recovered and reused.

  Examples of the organic solvent include polar organic solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, hexaethylphosphate triamide, and γ-butyrolactone. , Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; esters such as methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate; diethyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, ethylene glycol mono Ethers such as butyl ether (butyl cellosolve), diethylene glycol dimethyl ether, tetrahydrofuran; hexane, heptane, benzene, toluene, xylene, etc. Halogenated hydrocarbon compounds such as dichloromethane and chlorobenzene; phenols such as cresol and chlorophenol; tertiary amines such as pyridine, etc., but the present invention is limited to such examples only is not. These organic solvents may be used alone or in combination of two or more. The amount of the organic solvent is preferably adjusted so that the insulating coating has a desired viscosity when being attached to the surface of the conductor.

  The viscosity of the insulating paint is not particularly limited as long as the insulating paint can be uniformly attached to the conductor. Since the viscosity of insulating paint usually varies depending on the type of spray nozzle that sprays the insulating paint and the type of resin used in the insulating paint, it cannot be determined unconditionally. It is preferable to determine appropriately according to the kind of resin used. The viscosity of the insulating paint may be adjusted, for example, by adjusting the solid content or solvent amount of the insulating paint, or by adjusting the temperature of the insulating paint when the insulating paint is attached to the conductor. Also good.

  By immersing the conductor in a conventional liquid tank filled with insulating paint, the insulating paint is attached to the conductor, and the conductor with the insulating paint attached is inserted into the opening of the coating die, so that the excess insulation attached to the outer periphery of the conductor. In the method of baking in a baking furnace (hereinafter referred to as the conventional method) after removing the paint, the insulating paint needs to have a low viscosity in order to form a uniform insulating film with a coating die. On the other hand, in this invention, since the means of making it adhere to the surface of a conductor by spraying insulating coating is taken, what has high viscosity can be used for insulating coating.

  Also, according to the conventional method, an insulating coating prepared by dissolving an insulating resin in an organic solvent is usually used. On the other hand, in the present invention, as an insulating paint, not only an insulating paint prepared by dissolving an insulating resin in an organic solvent, but also an insulating paint obtained by heating and melting an insulating resin, or a resin And a two-component type insulating paint comprising the curing agent thereof.

  In the case of using an insulating paint in which an insulating resin is heated and melted or a two-pack type insulating paint composed of a resin and its curing agent, it is not always necessary to use an organic solvent, and an organic solvent is used. Even if it is a case, the usage-amount can be reduced. Therefore, when these insulating paints are used, there is an advantage that air pollution due to the organic solvent volatilizing in the atmosphere can be suppressed.

  The temperature of the insulating paint when attaching the insulating paint to the conductor varies depending on the equipment to be used, but it is usually preferable that the temperature is from room temperature to 50 ° C.

  When adhering to the surface of the conductor by spraying the insulating paint, for example, as shown in FIG. 1, a discharge head 1 having a spray nozzle such as an inkjet head can be used. When the discharge head 1 having the spray nozzle is disposed in the vicinity of the conductor 2, the temperature of the spray nozzle can be easily controlled. Therefore, even if the insulating paint has a high viscosity, the insulating paint can be reduced in viscosity by controlling the heating temperature of the insulating paint with the spray nozzle, so that the insulating paint can be easily sprayed from the spray nozzle. Can do. Insulating paint is introduced into the discharge head 1 from an insulating paint container 4 filled with insulating paint via a conduit 3. The container for insulating paint 4 does not necessarily have a container shape. For example, when a two-pack type insulating paint is used, a two-liquid mixer may be used.

  The hole diameter of the spray nozzle can be appropriately determined according to the viscosity of the insulating paint used and the spraying form of the insulating paint sprayed from the nozzle.

  When the insulating paint is sprayed from the spray nozzle, it is preferable to spray the insulating paint on the surface of the conductor using an inkjet head as a discharge head. When an ink jet head is used, the insulating paint can be sprayed within a narrow range, so that the insulating paint can be prevented from scattering, and the paint can be appropriately attached to the predetermined position of the conductor by spraying at a high uniformity and high speed. .

  When an inkjet head is used, a piezoelectric element is disposed in a room containing the insulating paint, and the insulating paint is sprayed to the inkjet head by instantaneously increasing the pressure of the insulating paint using the vibration of the piezoelectric element. A heat generating element is disposed in the room containing the insulating paint or the insulating paint is heated by the heat generating element to generate bubbles, and the bubbles burst from the spray nozzle of the inkjet head. Can be sprayed. These are called on-demand systems, and have the advantage that the insulating paint can be quickly sprayed onto the conductor without wasteful use of the insulating paint.

  The spray amount per time of the insulating paint cannot be determined unconditionally because it varies depending on the type and viscosity of the insulating paint. For example, when an inkjet is used, the insulating paint can be sprayed on the conductor in an amount of 10 to 1000 pl (picoliter) per time.

  From the viewpoint of evenly attaching the insulating paint to the surface of the conductor by spraying the insulating paint, it is possible to spray the insulating paint on the surface of the conductor from not only one direction but also from multiple directions to form a uniform insulating layer on the conductor. preferable. In this case, an insulating layer having a uniform film thickness is provided by arranging a plurality of spray nozzles around the conductor, spraying the insulating paint from the spray nozzle, and uniformly attaching the insulating paint to the entire surface of the conductor. Can be formed.

  The number of spray nozzles disposed around the conductor is not particularly limited as long as a uniform insulating layer can be formed on the entire surface of the conductor. The number of spray nozzles disposed around the conductor is preferably selected so as to be optimal for each conductor.

  The insulating paint may be attached directly to the surface of the conductor, or may be attached via another layer. After the insulating paint is attached to the conductor, baking is performed. Although the baking temperature at the time of baking varies depending on the type of insulating paint, it cannot be determined unconditionally. However, from the viewpoint of improving the withstand voltage characteristics, it is usually preferably 300 to 450 ° C.

  In the present invention, after the insulating paint is applied to the surface of the conductor by spraying, the insulating paint is baked and the operation of forming the insulating layer is repeatedly performed. It is preferable from the viewpoint of being able to adhere and suppressing the generation of pinholes. The number of repetitions of the operation (hereinafter referred to as the number of sprays) varies depending on the film thickness of the insulating layer formed on the surface of the conductor, but is usually about 7 to 30 times.

  The film thickness of the formed insulating layer varies depending on the use of the insulated wire of the present invention and cannot be determined unconditionally. However, usually, from the viewpoint of protecting the conductor, it is preferably 3 μm or more, more preferably 5 μm. From the viewpoint of reducing the size of the coil manufactured using the insulated wire, it is preferably 40 μm or less.

  When using the manufacturing method of the present invention, it is possible to partially attach an insulating coating to a conductor, so that an insulated wire provided with a portion that does not have an insulating layer partially or an insulation that is partially thinned. An electric wire can be manufactured.

  Moreover, it becomes possible to attach different types of insulating paints simultaneously using a plurality of nozzles. In the conventional method, it was possible to stack different types of insulating paints in layers by repeating the number of coatings, but in the manufacturing method of the present invention, an insulated wire having a plurality of different insulating paints in one insulating layer Can also be manufactured. For example, an insulated wire having a vertical stripe pattern or a horizontal stripe pattern can be exemplified.

  In addition, in the case of an insulated wire used for a coil for terminal treatment, a resin having low heat resistance is attached to a portion where the terminal treatment (insulation film is removed by soldering, etc.) and heat resistant is applied to other portions. By attaching a high resin, an insulated wire that can achieve both heat resistance and solderability can be obtained.

  In other words, manufactures insulated wires covered with different resins on the circumference of a certain radius from the conductor center in the cross section perpendicular to the axis, insulated wires covered with different resins in the axial direction, and patterned insulated wires can do.

  Thus, the insulated wire obtained by the method for producing an insulated wire of the present invention can be used for, for example, a motor or the like, and can also be used as a wire for an ignition coil of an automobile.

  The embodiment disclosed above should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Discharge head 2 Conductor 3 Conduit 4 Insulating paint container

Claims (7)

  A method of manufacturing an insulated wire having a conductor and an insulating layer covering the conductor, the liquid insulating paint being atomized and sprayed, and attached to the conductor directly or via another layer, and then the insulating paint A method of manufacturing an insulated wire, comprising forming an insulating layer by baking.   The manufacturing method of the insulated wire of Claim 1 which sprays an insulating coating material on the surface of a conductor using an inkjet head.   The method of manufacturing an insulated wire according to claim 1 or 2, wherein a two-component insulating paint is used as the insulating paint, and the two liquids are mixed immediately before spraying the insulating paint.   The manufacturing method of the insulated wire in any one of Claims 1-3 which arrange | position a some spray nozzle around a conductor, and make it adhere to the surface of a conductor by spraying an insulating coating material from the said spray nozzle.   The method of manufacturing an insulated wire according to any one of claims 1 to 4, wherein the operation comprising spraying an insulating paint to adhere to the surface of the conductor, baking the insulating paint, and forming an insulating layer is repeated. .   The method for producing an insulated wire according to claim 1, wherein the insulating coating is diluted with a supercritical fluid. The method for manufacturing an insulated wire according to claim 6, wherein the supercritical fluid is supercritical carbon dioxide.

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