JP2010287476A - Enameled wire and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an enameled wire capable of restraining expansion at the time of winding a coil and preventing exposure of a conductor, and a method of manufacturing the same. <P>SOLUTION: An insulating film 3 is formed on the periphery of the conductor 2, tension members 4 are prepared inside the insulating film 3. The enameled wire has high tensile strength due to the tension members 4, and hardly extends since the tension members 4 play a role of protection to external force. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an enameled wire capable of suppressing elongation during coil winding and preventing exposure of a conductor, and a method for manufacturing the same.

  When manufacturing a device having a coil such as a motor (hereinafter, generically referred to as a motor), when winding the coil, work is performed by applying tension to the enamel wire. In order to increase the space factor of the enamel wire with respect to the coil iron core, it is necessary to apply a high tension to the enamel wire.

  However, if an excessively high tension is applied to the enameled wire during coil winding, the enameled wire may extend excessively. If the enameled wire extends excessively, the conductor cross-sectional area becomes smaller and the electric resistance becomes higher, causing problems such as deterioration of motor characteristics and overheating. Therefore, there is a limit to the tension applied to the enameled wire when winding the coil.

  For further miniaturization and higher output of the motor, an enameled wire that is difficult to stretch even when a high tension is applied during coil winding is desired.

  As such an enameled wire, a tension member made of ceramic fibers is provided at the center, and a conductive layer and an insulating layer are sequentially provided around the tension member to increase the tensile strength and make the enameled wire difficult to stretch. 1 is disclosed.

Japanese Patent Laid-Open No. 4-179003

  On the other hand, in the manufacture of a conventional motor, in order to increase the space factor of the enamel wire with respect to the coil iron core, the enamel wire is inserted so that there is no gap inside the coil iron core. At this time, an external force (pressure, frictional force, impact force, etc.) that exposes the conductor (conductive layer) from the surface of the insulating layer is applied, and the insulating layer may be destroyed to expose the conductor.

  Therefore, it is necessary not only to suppress the elongation of the enameled wire during coil winding, but also to prevent the conductor from being exposed when an external force that exposes the conductor from the surface of the insulating layer is applied. Since the enameled wire disclosed in Patent Document 1 is provided with a conductive layer and an insulating layer around the tension member in order, protection against external force is insufficient.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an enameled wire and a method for manufacturing the same that can solve the above-described problems, can suppress elongation during coil winding, and can prevent exposure of a conductor.

  In order to achieve the above object, the enameled wire of the present invention has an insulating film formed around a conductor and has a tension member inside the insulating film.

  The insulating coating may include a plurality of layers, and the tension member may be provided inside an outermost layer of the plurality of layers.

  The tension member may be made of an aromatic polyamide resin.

  The enameled wire manufacturing method of the present invention includes a step of placing a tension member around the conductor in the longitudinal direction of the conductor, and applying the insulating paint by inserting both the conductor and the tension member through a coating die. And a step of baking the insulating paint in a coating furnace to form an insulating coating.

  According to the present invention, it is possible to suppress elongation during coil winding and to prevent exposure of the conductor.

It is a cross-sectional view of an enameled wire showing an embodiment of the present invention. It is a block diagram of the apparatus which manufactures the enameled wire of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, an enameled wire 1 according to the present invention has an insulating coating 3 formed around a conductor 2 and a tension member 4 inside the insulating coating 3.

  In the present embodiment, the insulating coating 3 is a highly adhesive lower enamel coating (first insulating coating) 5 formed on the outer periphery (surface) of the conductor 2 and an upper enamel formed on the outer periphery of the lower enamel coating 5. It consists of two layers of a coating (second insulating coating) 6. The number of layers forming the insulating coating 3 is not limited to 2, and may be 1 or 3 or more. Each layer of the insulating coating 3 is formed by applying and baking an insulating paint.

  The tension member 4 is composed of a single filament having a required strength or a strand obtained by concentrating a plurality of filaments. The tension member 4 extends along the longitudinal direction of the conductor 2 with respect to the conductor 2 and is parallel to the conductor 2.

  The tension member 4 may be provided inside the insulating coating 3 so as to be integrated with the insulating coating 3, and may be disposed so as to be in direct contact with the surface of the conductor 2, or in direct contact with the surface of the conductor 2. You may arrange so that it may not. In the present embodiment, the tension member 4 is disposed inside the upper enamel coating 6 that is the outermost layer of the two layers forming the insulating coating 3. The tension member 4 may be arranged in a plurality of layers of the insulating coating 3.

  In the present embodiment, the tension members 4 are installed at four locations around the conductor 2. The tension members 4 are arranged at 90 ° intervals in the circumferential direction. The number of tension members 4 is not limited to this, and may be 1 to 3, 5 or more, and are arranged at equal intervals or at desired intervals in the circumferential direction.

  Next, the effect of the enameled wire 1 of the present invention will be described.

  The enameled wire 1 of the present invention has a high tensile strength and is difficult to stretch because a tension member 4 parallel to the conductor 2 is inserted into an insulating coating 3 formed around the conductor 2. For this reason, the elongation at the time of coil winding can be suppressed.

  Furthermore, the enameled wire 1 of the present invention is provided with an external force that exposes the conductor 2 from the surface of the insulating coating 3 because the tension member 4 is provided in close contact with the insulating coating 3 inside the insulating coating 3. In addition, the tension member 4 serves to protect against external forces, and the conductor 2 can be prevented from being exposed.

  That is, the enameled wire 1 of the present invention can be said to be a tension-resistant high-strength enameled wire. As a result, in the manufacture of the motor, the enameled wire 1 can be wound with a high tension, so that the space factor of the enameled wire with respect to the coil core can be increased, and the motor can be reduced in size and increased in output. it can.

  In addition, the enameled wire 1 of the present invention has high durability against impact and friction from the outside of the enameled wire 1 because the tension member 4 is provided inside the insulating coating 3.

  Next, the material and structure of the tension member 4 will be examined.

  For the tension member 4, an aromatic polyamide resin, particularly an aramid fiber is suitable. Aramid fiber is excellent in heat resistance and chemical resistance. Among the aramid fibers, the para-aramid fibers have a tensile strength of 3000 MPa and an elongation at break of less than 4%. Therefore, para-aramid fiber is suitable for the tension member 4 of the present invention.

  The enameled wire 1 has a restriction on the outer dimension, but if the diameter of the tension member 4 is large, the outer dimension of the enameled wire 1 may be larger than the restriction. Further, if the diameter of the tension member 4 is large, the cross-sectional shape of the enameled wire 1 is not a smooth circle, and abnormal appearance such as grains tends to occur. In that respect, the aramid fiber is an extremely fine filament and has a high tensile strength. By using several strands in which 100 aramid filaments having a filament diameter of about 8 μm are bundled, the cross-sectional shape and dimensions of the enameled wire 1 can be obtained. A high-strength enameled wire 1 that maintains stability and smoothness of appearance can be obtained.

  In general, an enameled wire with a wire diameter of 0.8 mm has a tensile strength of 280 MPa and an elongation at break of 50%, so that it has about 1000 aramid filaments with a filament diameter of 8 μm and has the same strength as a general enameled wire. The elongation at break can be suppressed to about 4% while maintaining the above. Actually, the tension generated when the conventional coil is wound is 30% or less of the tensile strength, so 300 aramid filaments are enough to withstand this. If the tension at the time of coil winding is increased to 50% of the tensile strength and the elongation at break is reduced to about 4%, about 500 aramid filaments are sufficient. Therefore, by using 4 to 5 strands in which about 100 aramid filaments are bundled, the enameled wire 1 of the present invention can exhibit sufficient tensile strength and high strength.

  When applying the insulating paint to provide the tension member 4 inside the insulating coating 3, if air gets caught in the outer periphery of the tension member 4, when the insulating paint is baked, particles etc. Appearance abnormality occurs. Further, when the enameled wire 1 is bent and twisted, cracking of the insulating coating 3 and peeling of the tension member 4 occur due to the low adhesion between the insulating coating 3 and the tension member 4. In order to prevent this, the adhesion of the lower layer enamel coating 5 and the upper enamel coating 6 and the tension member 4 is increased by reducing the number of filaments converging in the tension member 4 or increasing the wettability of the tension member 4. In order to improve the wettability of the tension member 4, it is preferable to perform pretreatment such as UV irradiation treatment and silane coupling treatment.

  Next, the manufacturing method of the enameled wire 1 of the present invention will be described.

  As shown in FIG. 2, the manufacturing apparatus 21 for manufacturing the enameled wire 1 according to the present invention is configured such that the intermediate product 7 in which the lower enamel coating 5 is formed on the outer periphery of the conductor 2 runs vertically upward. The tension member guide pulley 22 for guiding the tension member 4 and the insulating paint 23 are accumulated in the middle of the travel route, and the paint tank 25 having the passage hole 24 of the intermediate product 7 on the bottom surface and the applied insulating paint 23 are squeezed. The painting dies 26 are arranged in order. The manufacturing apparatus 21 illustrated in FIG. 1 has tension member guide pulleys 22 at four locations around the intermediate product 7 in order to manufacture the enameled wire 1 having the tension members 4 according to the embodiment of FIG. Has been placed.

  First, an intermediate product 7 in which the lower enamel coating 5 is formed on the outer periphery of the conductor 2 is manufactured. However, since this step may be a known method, description thereof is omitted.

  Next, a process of placing the tension member 4 along the intermediate product 7 is performed. That is, the tension member guide pulley 22 causes the tension member 4 supplied from a supply source (not shown) to run along the intermediate product 7 in a state of being tensioned in parallel with the intermediate product 7 with respect to the lower enamel coating 5 of the intermediate product 7 to be traveled. .

  Next, a step of applying an insulating paint is performed. The intermediate product 7 along with the tension member 4 is passed through the passage hole 24 of the paint tank 25, immersed in the insulating paint 23 and pulled up. As a result, the insulating paint 23 is applied to the tension member 4 and the intermediate product 7, the insulating paint 23 is squeezed by being inserted through the coating die 26, and the insulating paint 23 to be the upper enamel coating 6 is applied. Become.

  Thereafter, drying and baking are performed in a coating furnace (not shown) to form an upper enamel coating 6 and obtain the enameled wire 1 of the present invention. In addition, after aligning the tension member 4, it can finish to a desired outer diameter size by repeating insulation coating application and baking of the upper enamel coating 6 a plurality of times.

  According to the present invention, a tensile strength high strength enameled wire for a coil winding tension of 70 N is manufactured. The conductor diameter is 0.8 mm, and the finished outer diameter is 0.92 mm. First, an intermediate product 7 is obtained by coating and forming an ester imide film having a thickness of 6 μm as a lower enamel coating 5 on the outer periphery of the conductor 2. Four strands obtained by converging 50 aramid filaments having a filament diameter of 8 μm are arranged along the outer periphery of the intermediate product 7 evenly. A polyesterimide film having a thickness of 12 μm is formed on the outer periphery as a first upper enamel coating 6. Further, four strands, each of which 50 aramid filaments having a filament diameter of 8 μm are bundled, are arranged along the outer periphery at four locations. A polyesterimide film having a thickness of 12 μm is formed on the outer periphery as a second upper layer enamel film 6. On the outer periphery, an amidoimide film having a thickness of 28 μm is formed as a third upper enamel film 6. Further, a high-lubricating layer is applied and formed to a thickness of 2 μm as the outermost layer.

1 Enamelled wire 2 Conductor 3 Insulating coating 4 Tension member 5 Lower enamel coating 6 Upper enamel coating

Claims (4)

  An enameled wire characterized in that an insulating coating is formed around a conductor and a tension member is provided inside the insulating coating.   The enameled wire according to claim 1, wherein the insulating coating includes a plurality of layers, and the tension member is provided in an outermost layer of the plurality of layers.   The enameled wire according to claim 1, wherein the tension member is made of an aromatic polyamide resin.   A step of extending a tension member around the conductor in the longitudinal direction of the conductor, a step of applying the insulating paint by inserting both the conductor and the tension member through a coating die, and baking the insulating paint in a coating furnace And a step of forming an insulating film.

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