JP2013206783A - Method of producing rectangular insulated wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a compact rectangular insulated wire with high formation accuracy.SOLUTION: On the surface of a rectangular conductor 101, an insulation coat 102 is formed by electrodeposition coating (first step), a non-electrodeposition paint 23' adhering to the insulation coat 102 is removed (second step), and while abutting a water-repellent body 104 against both ends at least in the width direction of one pair of facing surfaces 101a of the rectangular conductor 101, the rectangular conductor 101 is moved relatively to the water-repellent body 104 and the one pair of facing surfaces 101a are flattened (third step), and thereafter the insulation coat 102 is hardened, thus forming a rectangular insulated wire 1 (fourth step).

Description

  The present invention relates to a method for producing a low voltage flat insulated wire.

  Coreless flat coils are often used in small motors for low voltage such as flat brushless motors incorporated in various small and lightweight electric devices such as video tape recorders and portable tape recorders. As the copper wire used as the winding in the coreless flat coil, a rectangular insulated wire in which an insulating coating such as varnish is formed on a rectangular conductor may be used. As a method for forming the insulating coating, there is a method disclosed in Patent Document 1.

Japanese Patent No. 2649979

  A flat insulated wire used for a coreless flat coil is usually formed by rolling a round conductor into a flat conductor and providing an insulating coating on the surface of the flat conductor. Is usually formed by dip coating, which is used for coating wire. Immersion coating is a coating method in which the object to be coated is dipped in a paint (such as varnish) and then pulled up, and then the paint is dried. The coating is repeated until a predetermined insulating film thickness is obtained.

  However, in the dip coating, it is difficult for the paint to adhere particularly to the corners of the flat rectangular conductor, resulting in uneven insulation coating. When an extremely fine flat conductor wire with an insulating coating formed by such dip coating is wound as a coil for a low-voltage motor, particularly thin corners of the insulating coating tend to cause poor insulation.

  In order to solve the problems of the dip coating, electrodeposition coating may be employed. Electrodeposition coating is a coating method in which an electrode is inserted into a water-based paint, DC current is applied, and paint particles having a negative charge are moved toward the anode to deposit it on the anode. In electrodeposition coating, in general, the object to be coated is energized as an anode, and a container containing paint is applied as a cathode (if the container is an insulator, a metal such as copper or platinum is inserted into the paint as a cathode). Then, after depositing the paint on the surface of the object to be coated of the anode, it is taken out and the baking finish is completed.

  However, in the electrodeposition coating, electric field concentration occurs at the corners of the flat rectangular conductor, so that the insulating coating at the corners becomes thick as shown in FIG. 7, and as a result, the wire thickness h1 at the corners becomes the center in the wire width direction. It becomes thicker than the wire thickness h2 of the part (h1> h2). When such electric wires are overwrapped, a gap α is formed between the insulating coatings 201 and 201 of the rectangular insulated wires 200 adjacent to each other in the vertical direction, that is, the upper and lower rectangular insulated wires 200 and 200, and the coil conductor The space factor (space factor: total conductor volume / total coil volume) decreases. In general, the larger the space factor of the rectangular insulated wire 200 is, the better, and the unevenness of the electrodeposition coating is not preferable.

Therefore, for example, in Patent Document 1,
(1) Primary rolling a round conductor to form a flat conductor.
(2) An insulating coating is formed on the surface of the flat conductor by electrodeposition coating, and the insulating coating is semi-cured to form a quasi-flat rectangular wire.
(3) Secondary rolling the quasi-flat wire into a flat wire,
(4) A rectangular insulation wire is cured by curing the insulation film of the rectangular wire.
This improves the space factor.

  However, as the demand for miniaturization progresses, the dimensions (width and thickness) of the rectangular conductor wire, which is the electrodeposited material, are reduced, and the thickness of the insulating coating formed by electrodeposition is accordingly reduced. Therefore, it is difficult to obtain a semi-cured state of the insulating coating, which is a feature of the manufacturing method in Patent Document 1. For this reason, when the quasi-flat wire is secondarily rolled into a flat wire, the insulating coating adheres to the rolling roll and is peeled off from the quasi-flat wire.

  Accordingly, an object of the present invention is to provide a novel method for producing a rectangular insulated wire that overcomes the problems found in the above-described immersion coating and electrodeposition coating.

In order to solve the above problems, the method for producing a rectangular insulated wire of the present invention has the following characteristics. That is, the present invention
A first step of forming an insulating coating on the surface of a rectangular conductor having a rectangular cross-sectional shape and serving as a wire core of a rectangular insulating wire by an electrodeposition coating process;
A second step of removing the non-electrodeposition paint adhering to the insulating coating;
In a state where the water repellent body is in contact with at least both ends in the width direction of the one opposing surface pair of the flat rectangular conductor, the rectangular conductor is moved relative to the water repellent body, thereby the one opposing surface pair. A third step of flattening;
A fourth step of curing the insulating coating to form the rectangular insulated wire;
Is included.

  According to the said structure, the insulating film formed in the surface of a flat conductor by an electrodeposition coating process has water solubility. On the other hand, the water-repellent body has a property of repelling moisture and having extremely low adhesion to a water-soluble insulating film. Therefore, even if the flat rectangular conductor (insulating coating) is flattened by moving the flat rectangular conductor relative to the water repellent body, the insulating coating does not stick to the water repellent body and peel off from the flat rectangular conductor. From the above, when the method of the present invention is carried out, the insulation coating of the rectangular insulated wire finally obtained is coupled with the ability to easily apply uniform coating, which is a general characteristic of electrodeposition coating. One opposing surface pair has a uniform thickness with high accuracy. As described above, in the present invention, it is possible to perform the flattening process with high accuracy, and the conventional problems are solved. In addition, in this invention, although the cross-sectional shape of the flat insulated wire is made into the rectangular shape, the rectangular shape here is a rectangular shape in general, and the other opposing surface pair is a curved surface. A track shape is also included. In addition, if the present invention is implemented in an electric wire configuration in which one opposing surface pair has a longer rectangular shape or elliptical shape than the other opposing surface pair, the effect becomes even more remarkable.

  In addition, in the third step, the rectangular conductor from which the non-electrodeposition paint has been removed in a state where the water-repellent body is opposed to each other with a separation interval set according to the wire thickness of the rectangular insulating wire. It is preferable that the one opposing surface pair is flattened by passing between the water repellent bodies along the conductor longitudinal direction so that the one opposing surface pair faces the water repellent body. Then, a flattened rectangular insulated wire having a desired thickness can be produced with high accuracy.

  Furthermore, in the third step, it is preferable to use, as the water repellent body, a water repellent roller having an axis that is parallel to the width direction of the rectangular conductor and having at least a surface made of a water repellent material. By doing so, the water repellent body becomes a rotating body and rolls relative to the flat conductor, so that the peelability of the water repellent body with respect to the insulating coating is improved, and the insulating coating is more difficult to peel off from the flat conductor.

  Furthermore, in the third step, the rectangular conductor from which the non-electrodeposition paint has been removed while rotating the water-repellent roller in a direction along the conveying direction of the flat conductor from which the non-electrodeposition paint has been removed is driven. It is preferable that the rotation speed of the water-repellent roller is made equal to the conveyance speed of the rectangular conductor from which the non-electrodeposition coating material has been removed. The peelability of the water body is further improved, and the insulating coating is more difficult to peel off from the flat conductor.

  Since the manufacturing method of the flat insulated wire of this invention is comprised as demonstrated above, there exists an effect described below.

  It is possible to improve the adhesion failure of the insulating film to the flat rectangular conductor (particularly the corner) seen in the dip coating, and a uniform insulating film can be formed on the surface of the flat rectangular conductor.

  In addition, since a semi-curing step as in the prior art is no longer required, productivity is improved and a flat rectangular conductor (width and thickness is small) that is difficult to produce a semi-cured state. Or a thin insulating film), a uniform insulating film can be formed. Therefore, it has become possible to produce a flat rectangular insulated wire with high formation accuracy without any dimensional constraints.

  Furthermore, since one pair of opposing surfaces of the insulating coating is flattened using a water repellent body before the insulating coating is cured, a rectangular insulated wire with high outer diameter dimensional accuracy can be obtained without causing peeling or damage to the insulating coating. Can be manufactured.

  Therefore, when the rectangular insulated wire obtained by the manufacturing method of the present invention is wound, the space factor of the coil conductor becomes good, and the coil can be miniaturized.

(A) is a figure which shows process (1) of the manufacturing method of the flat insulated wire of one Embodiment of this invention, (b), (c) is sectional drawing which shows the electric wire shape in the middle of the process, (B) is the sectional view on the AA line of (a), (c) is the sectional view on the BB line of (a). (A) is a figure which shows the process (2) of the manufacturing method of the flat insulated wire of one Embodiment of this invention, (b), (c) is sectional drawing which shows the electric wire shape in the middle of the process, (B) is the CC sectional view taken on the line of (a), (c) is the DD sectional view taken on the line of (a). (A) is a figure which shows process (3) of the manufacturing method of the flat insulated wire of one Embodiment of this invention, (b), (c) is sectional drawing which shows the electric wire shape in the middle of the process, (B) is the EE sectional view taken on the line of (a), (c) is the FF sectional view taken on the line of (a). (A) is a figure which shows the process (4) of the manufacturing method of the flat insulated wire of one Embodiment of this invention, (b), (c) is sectional drawing which shows the electric wire shape in the middle of the process, (B) is the GG sectional view taken on the line of (a), (c) is the HH sectional view taken on the line (a). (A) is a figure which shows process (5) of the manufacturing method of the flat insulated wire of one Embodiment of this invention, (b), (c) is sectional drawing which shows the electric wire shape in the middle of the process, (B) is the II sectional view taken on the line of (a), (c) is the JJ sectional view taken on the line (a). It is a figure which shows the modification of the manufacturing method of the flat insulated wire of this invention. It is sectional drawing with which it uses for description of the subject of a prior art example.

  Next, each process of the manufacturing method of this invention is explained in full detail in order based on FIGS. Before explaining the manufacturing method, the rectangular insulated wire 1 manufactured by the manufacturing method of the present invention will be described. The rectangular insulated wire 1 is used by being wound around a coil for a low voltage motor or the like. Accordingly, in the present invention, the rectangular insulated wire 1 has a thickness of 20 to 500 μm, The width is about 100 to 4000 μm, and the thickness / width ratio is about 1: 3 to 1:50. As shown in FIG. 5C, the flat rectangular insulated wire 1 has a shape in which the surface of a flat rectangular conductor 101 is covered with an insulating coating 102. The rectangular conductor 101 has a rectangular cross-sectional shape in which one opposing surface pair 101a is longer than the other opposing surface pair 101b, and the insulating coating 102 is formed on the surface of the rectangular conductor 101 by an electrodeposition coating process. ing. One opposing surface pair 101a and the other opposing surface pair 101b may have the same length, and the present invention can be similarly implemented in such a wire structure.

  Hereinafter, the detail of the manufacturing method of the flat insulated wire 1 is demonstrated. This manufacturing method includes the following steps (1) to (5).

  Step (1): As shown in FIGS. 1A to 1C, a round conductor 100 having a diameter of about 50 to 1500 μm made of copper, aluminum, copper clad aluminum, or the like is rolled by conventional means such as a rolling roll 21. Thus, the rectangular conductor 101 having a thickness of about 10 to 500 μm and a width of about 100 to 4000 μm and a thickness / width ratio of about 1: 3 to 1:50 is roughly finished.

  Step (2): The flat rectangular conductor 101 obtained in the step (1) is dipped in the electrodeposition coating tank 22 and pulled up to perform electrodeposition coating, and the flat rectangular conductor 101 has a thickness of about 1 to 30 μm. 102 is formed. Step (2) is an example of the first step of the present invention.

  Specifically, as shown in FIGS. 2A to 2C, the rectangular conductor 101 has a predetermined traveling speed upward from an unillustrated feeding roller installed below the electrodeposition coating tank 22. Is sent out along the conductor longitudinal direction. The rectangular conductor 101 has a lower end connected to a positive electrode (not shown) of the power source so as to be a positive pole. The rectangular conductor 101 is inserted into the electrodeposition coating tank 22 through the introduction hole 24 provided in the bottom wall portion of the electrodeposition coating tank 22 in which the electrodeposition liquid 23 is stored, and then the interior of the tank 22 is lowered. Is continuously transported upward and drawn out from the electrodeposition coating tank 22.

  In the electrodeposition coating tank 22, negative electrodes 25 and 25 connected to a negative electrode (not shown) of a power source are inserted. The electrodeposition liquid 23 in the electrodeposition coating tank 22 has resin fine particles (not shown) during migration as a solute. As the insulating coating (electrodeposition liquid 23) used for electrodeposition coating, a known one (water-dispersible epoxy / acrylic paint, etc.) may be applied. Specifically, water-dispersible polyurethane, epoxy / acrylic, Examples include polyesterimide and water-soluble polyimide. However, the insulating paint (electrodeposition liquid 23) is not limited to these.

  During electrodeposition, the resin fine particles in the electrodeposition liquid 23 are negatively charged by the negative electrodes 25 and 25 described above, and therefore are attracted to the flat rectangular conductor 101 which is a positive pole by an electric force. The resin fine particles adhere to the outer surface of the rectangular conductor 101 and form an insulating coating 102 covering the outer surface of the rectangular conductor 101 as electrodeposited resin fine particles. Here, in the electrodeposition coating, since electric field concentration occurs at the corners of the flat rectangular conductor 101, the four corners 102a of the insulating coating 102 tend to be thick. As a result, the thickness at both ends in the width direction is the center in the width direction. The non-flat shape becomes thicker than the portion. Hereinafter, such a non-flat shape is referred to as a dogbone shape. The rectangular conductor 101 having the dog-bone-shaped insulating coating 102 ′ is hereinafter referred to as a rectangular insulating electric wire 1 </ b> A. In the flat rectangular insulated wire 1A, the non-electrodeposition paint (unattached electrodeposition liquid 23 ') remains.

  Step (3): By spraying gas onto the rectangular insulated wire 1A pulled up from the electrodeposition coating tank 22, the non-electrodeposition paint (unattached electrodeposition liquid 23 ') adhering to the insulating coating 102' is applied. Remove. Step (3) is an example of the second step of the present invention.

  Specifically, as shown in FIGS. 3A to 3C, gas is sprayed from the spray nozzle 103 to the flat insulated wire 1 </ b> A pulled up from the electrodeposition coating tank 22 from obliquely above. The gas is air, inert gas, or the like. Nitrogen gas is preferred as the inert gas. As a result, the undeposited electrodeposition liquid 23 ′ adhering to the surface of the insulating coating 102 ′ drops downward along the flat rectangular insulated wire 1 </ b> A, thereby making the adhesion of the insulating coating 102 to the flat rectangular conductor 101 uniform. . The temperature of the blowing gas is, for example, 5 to 35 ° C. The gas spray amount is, for example, 10 to 80 L / min. Even after the step (3), the thickness of the corner portion 102a of the insulating coating 102 'remains thick, and thus the rectangular insulated wire 1A remains in a dogbone shape. Hereinafter, the rectangular insulated wire 1A from which the undeposited electrodeposition liquid 23 'has been removed will be referred to as a rectangular insulated wire 1B. The step (3) may be configured to wipe off the unattached electrodeposition liquid 23 ′ from the flat rectangular insulated wire 1 </ b> A by bringing the electrodeposition liquid removing roller into contact with the flat rectangular insulated wire 1 </ b> A in addition to gas spraying. .

  Step (4): As shown in FIGS. 4A to 4C, the insulating coating 102 of the flat insulated wire 1B from which the electrodeposition liquid 23 ′ that has not been deposited in the step (3) is removed is formed by the water repellent body 104. Flatten. Hereinafter, the rectangular insulated wire 1B having a predetermined shape by flattening the insulating coating 102 is referred to as a rectangular insulated wire 1C. Step (4) is an example of the third step of the present invention.

  A pair of water repellent bodies 104 is provided. The pair of water-repellent bodies 104 are opposed to each other with a separation interval set according to the wire thickness of the flat rectangular insulated wire 1 that is a finished product. Each of the water-repellent bodies 104 is composed of a water-repellent roller having a short axial length that is rotatable about the shaft center 104a. ) In parallel with. The axial length of the water repellent body 104 is set to be equal to or slightly longer than the width dimension of the rectangular insulated wire 1B (the width direction dimension of the one opposed surface pair 101a). The water repellent body 104 is linked to the drive motor 105 and is driven to rotate by the drive motor 105. The water repellent body 104 on the left side in the figure is driven to rotate counterclockwise by the drive motor 105, and the water repellent body 104 on the right side in the figure is driven to rotate clockwise by the drive motor 105. When the step (4) is performed, the rectangular insulated wire 1B is conveyed along the longitudinal direction of the wire from the bottom to the top in the figure by a conveyance mechanism (not shown). As described above, the rotation direction of the water bodies 104 and 104 is set to follow the conveyance of the flat rectangular insulated wire 1B. Furthermore, the rotation speed r of the water repellent bodies 104 and 104 is set to the rectangular insulated wire 1B. Is set equal to the transport speed v. Here, the equivalent to the conveyance speed v of the rectangular insulated wire 1B is a speed range (0.9 v ≦ r ≦ v) including a speed slightly lower than the conveyance speed v1 of the rectangular insulated wire 1B. Although the water repellent body 104 is preferably driven to rotate, it may be rotated without being driven following the conveyance of the rectangular insulated wire 1B.

  It is important that the water repellent body 104 does not peel off the insulating coating 102 formed on the flat rectangular conductor 101 from the flat rectangular conductor 101. For this reason, the water repellent body 104 is made of a fluororesin such as polytetrafluoroethylene (PTFE) having high water repellency. The However, any material having high water repellency may be used. The entire water-repellent body 104 may be composed of a water-repellent material, but at least only the peripheral surface portion may be composed of a water-repellent material.

  In the step (4), the rectangular insulated wire 1B that has undergone the step (3) is oriented so that one of the opposed surface pairs (long sides) 101a faces the water-repellent body 104, and in this state, the rectangular insulated wire 1B is repelled. By passing between the water bodies 104, the surface of the insulating coating 102 on the one opposing surface pair 101 a side is flattened with a thickness according to the thickness of the flat insulated wire 1. Thereby, the thick part of the corner | angular part 102a of the insulating film 102 is leveled, and is planarized by the thickness equivalent to the center part of the width direction.

  As described above, the rectangular insulated wire 1B is passed between the water-repellent bodies 104 along the longitudinal direction of the wire while the water-repellent body 104 is fixedly arranged in a rotatable manner, and the rectangular insulated wire 1B is fixedly arranged. In addition, the rectangular insulated wire 1 ′ may be sandwiched by the rotatable water repellent body 104, and the water repellent body 104 may be moved along the longitudinal direction of the rectangular insulated wire 1 B in this state.

  In the flattening process described above, the peripheral surface of the water repellent body 104 is made of a water repellent material, so that the insulating coating 102 is difficult to adhere to the water repellent body 104. Furthermore, the water-repellent body 104 has a rotatable cylindrical shape and rolls on the surface of the insulating coating 102, so that the insulating coating 102 is more difficult to adhere to the water-repellent body 104. Furthermore, since the water-repellent body 104 itself is driven to rotate at a speed equivalent to the conveying speed of the flat insulated wire 1B, the insulating coating 102 is more difficult to adhere to the water-repellent body 104. From the above, the insulating coating 102 hardly peels from the flat conductor 101 during the planarization treatment of the insulating coating 102. In addition, the water repellent body 104 may be arranged with an offset (step difference) in addition to the opposed arrangement with the rectangular insulated wire 1B interposed therebetween.

  In the flattening process (step (4)) described above, the water repellent body 104 that is in contact with the insulating film 102 formed on the one opposing surface pair 101a of the flat conductor 101 is newly provided. The surface of a transport roller (not shown) used for transporting the insulated wire 1B may be made of a water-repellent material, and the transport roller may be disposed to face the water-repellent body.

  Further, it is the corner portion 102a of the insulating coating 102 whose thickness is thicker than that of the other portion that needs to be planarized. For this reason, the water repellent body 104 may be provided only in a portion that contacts the corner portion 102 a of the insulating coating 102.

  Step (5): As shown in FIGS. 5 (a) to 5 (c), the flat rectangular insulated wire 1C having been subjected to the flattening process is heated in a curing furnace 26 at a temperature of about 150 to 500 ° C. (preferably 180 to 450 ° C. And is cured at 350 ° C. optimally to obtain a rectangular insulated wire 1. Then, the produced flat insulated wire 1 is wound up. Step (5) is an example of the fourth step of the present invention.

  The temperature range of the firing furnace 26 is set so that the temperature gradually increases, for example, 50 ° C. → 100 ° C. → 150 ° C. → 200 ° C. → 250 ° C. → 300 ° C. → 350 ° C. It is preferable, and by doing so, it is possible to obtain a dense and uniform insulating film 102 by suppressing foaming of the insulating film 102 due to a rapid temperature rise.

  As described above, the insulation coating 2 of the rectangular insulated wire 1C is completely cured by performing a heat curing process of finally passing through a curing furnace having a temperature of 350 ° C. As a result, the rectangular insulated wire 1 comprising the rectangular conductor 101 and the insulating coating 2 having a uniform thickness is provided as a product.

  Even if the rectangular insulated wire 1 obtained in this way is wound around a coil, no gap is generated between the adjacent wires in the vertical direction, and the space factor of the rectangular conductor 101 in the coil increases.

  In the above-described step (4), the drive motor 105 that rotationally drives the water-repellent body 104 including the water-repellent roller is provided, but the drive motor 105 may be omitted. Furthermore, as shown in FIG. 6, the water-repellent body 104 'may be constituted by a spatula-like water-repellent squeegee that does not rotate. In FIG. 6, the water repellent body 104 ′ is illustrated in a state slightly separated from the flat rectangular insulated wire 1 C, but actually the water repellent body 104 ′ is in contact with the flat rectangular insulated wire 1 C. Not too long.

1 Flat insulated wire 1A to 1C Flat insulated wire (during manufacturing)
21 Roll 22 Electrodeposition tank 23 Electrodeposition liquid 23 'non-deposition electrodeposition liquid (non-electrodeposition paint)
24 Introducing hole 25 Negative electrode 26 Curing furnace 100 Round conductor 101 Flat conductor 101a One opposing surface pair 101b The other opposing surface pair 102 Insulating coating 102a Corner portion 103 Spray nozzle 104 Water repellent body 104a Axle 105 Drive motor

Claims (4)

A first step of forming an insulating coating on the surface of a rectangular conductor having a rectangular cross-sectional shape and serving as a wire core of a rectangular insulating wire by an electrodeposition coating process;
A second step of removing the non-electrodeposition paint adhering to the insulating coating;
In a state where the water repellent body is in contact with at least both ends in the width direction of the one opposing surface pair of the flat rectangular conductor, the rectangular conductor is moved relative to the water repellent body, thereby the one opposing surface pair. A third step of flattening;
A fourth step of curing the insulating coating to form the rectangular insulated wire;
including,
A method for producing a rectangular insulated wire, characterized in that: In the third step, in the state where the water-repellent body is disposed oppositely with a spacing interval set according to the thickness of the flat insulated wire, the rectangular conductor from which the non-electrodeposition paint has been removed, The one opposing surface pair is flattened by passing between the water repellent bodies along the conductor longitudinal direction in a direction in which the one opposing surface pair faces the water repellent body,
The manufacturing method of the flat insulated insulated wire of Claim 1 characterized by the above-mentioned. In the third step, as the water repellent body, a water repellent roller having an axial center parallel to the width direction of the rectangular conductor and having at least a surface made of a water repellent material is used.
The manufacturing method of the flat insulated insulated wire of Claim 1 or 2 characterized by the above-mentioned. In the third step, the water-repellent roller is driven to rotate in a direction along the conveying direction of the non-electrodeposited paint-removed flat conductor, while the non-electrodeposit-painted flat conductor is removed. Pass between water bodies, and the rotational speed of the water repellent roller is equal to the conveying speed of the rectangular conductor from which the non-electrodeposition paint has been removed,
The manufacturing method of the rectangular insulated wire of Claim 3.

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