JP6688107B2 - Coil and method of manufacturing coil - Google Patents

Description

  Embodiments of the present invention relate to a coil and a method for manufacturing the coil.

  The Litz wire used for the coil is a multi-conductor magnet wire (conductor for winding) formed by twisting a plurality of enameled wires (thin wires). Litz wire has come to be widely used as a magnet wire for a coil of a high frequency electric device. When the frequency of the applied current becomes high, the AC effect increases due to the skin effect and the loss becomes large. The reason why litz wire is used for the coil of high-frequency electric equipment is to subdivide the skin current by dividing the conductor into a large number using an enameled wire having an insulating film, and thereby reducing the increase in AC resistance. . In general, a round litz wire with a circular cross section is used, but a rectangular litz wire with a rectangular cross section is also used in order to increase the coil space factor when winding an electric device coil.

JP-A-2000-90747

  An embodiment of the present invention aims to provide a coil having excellent insulation and a method for manufacturing the coil.

The coil according to the embodiment is a winding conductor in which conductive thin wires are bundled and is molded with a resin, and a tape having a property of not permeating a liquid resin is provided around the winding conductor. The tape is wound while being provided, and the periphery of the tape and the periphery of the winding conductor are covered with a non-woven fabric cured by the resin, and the resin is filled between the thin wires without a gap. The winding conductor is used.

The figure which shows the schematic structural example of the coil which concerns on embodiment. Diagram showing the cross-sectional structure of the coil The figure which shows the state of the intermediate process of the manufacturing process of a coil The figure which shows the state of the intermediate process of the manufacturing process of a coil The figure which shows the state of the intermediate process of the manufacturing process of a coil The figure which shows the state of the intermediate process of the manufacturing process of a coil The figure which shows the state of the intermediate process of the manufacturing process of a coil Sectional drawing which shows the state of the intermediate process of the manufacturing process of a coil The figure which shows the state of the intermediate process of the manufacturing process of a coil

An embodiment will be described below with reference to the drawings. In the description of the embodiments, substantially the same components are designated by the same reference numerals, and the description thereof will be omitted.
FIG. 1 is a perspective view showing a schematic configuration example of a coil 10 shown as an example of the embodiment. FIG. 2 is a cross-sectional view showing the structure of the coil 10 shown in FIG. The coil 10 is composed of a litz wire 12 which is a winding conductor formed by twisting and bundling thin wires made of copper, for example, element wires. The coil 10 is configured such that the litz wire 12 has a hollow at the center and has a concentric shape, for example, an ellipse, and is closely wound in a spiral shape, and is wholly solidified with a resin. A portion A in FIG. 1 corresponds to a basic unit of the litz wire 12, and FIG. 2 shows a basic configuration of the litz wire 12 that constitutes the coil 10. The litz wire 12 used in the coil 10 is a multi-conductor magnet wire (winding) formed by twisting and bundling a plurality of electrically conductive wires 14 (thin wires) insulated from each other, for example, a plurality of enamel wires having an insulating coating. Conductor).

  As shown in FIG. 2, the litz wire 12 includes a first unit litz wire 16 formed by twisting a plurality of element wires 14. Furthermore, a plurality of first unit litz wires 16 are twisted together to form a second unit litz wire 18. The litz wire 12 is formed by covering the periphery of the second unit litz wire 18 with a binding band 22 and a surrounding band 24.

  As the binding band 22, for example, a tough aramid fiber tape is used. The lashing band 22 has a paper tape shape, and by winding around the second unit litz wire 18, the first unit litz wire 16 or the strand 14 forming the second unit litz wire 18 is unwound. Used to tie up so that there is no. The fastening band 22 is wound around the second unit litz wire 18 so that the gap G is formed between the fastening bands 22 to be wound, as shown in FIG.

  The surrounding band 24 winds around the second unit litz wire 18 secured by the securing band 22 and covers it. The wrapping band 24 is formed by impregnating a nonwoven fabric tape 32, which will be described later, with a resin liquid 38, which will be described later, and curing the resin solution 38. In this case, the non-woven fabric tape 32 can be mentioned as an example of a material that can penetrate and permeate the resin liquid 38 described later in the manufacturing process of the coil 10 described later and can be wound around the second unit litz wire 18. It is a thing. The material forming the wrapping band 24 is not limited to the non-woven tape 32 as long as it has such characteristics.

  In the second unit litz wire 18, an insulating cured resin 20 (resin) exists between the plurality of element wires 14 or between the plurality of first unit litz wires 16 without any gap. Further, the cured resin 20 is present between the wire 14 and the lashing band 22 and the surrounding band 24, and also between the first unit litz wire 16 and the lashing band 22 and the surrounding band 24 without any gap. That is, the second unit litz wire 18 is a plurality of element wires 14 or a plurality of first unit litz wires 16 that are cured by a resin solution 38 described later and integrally hardened, and are solidified by the cured resin 20. It is integrated and fixed to. Further, in the litz wire 12, the strand 14, the first unit litz wire 16, the second unit litz wire 18, the fastening band 22, and the surrounding band 24 are hardened by the hardening resin 20 without a gap. That is, the coil 10 and the litz wire 12 constituting the coil 10 have a structure in which the spaces between and around the wires 14 are filled with the cured resin 20 without any gaps and molded.

  As the curing resin 20, that is, the resin liquid 38 described later, a resin having high thermal conductivity, that is, heat dissipation may be adopted. As the resin having a high thermal conductivity, for example, an epoxy resin to which a micro-sized highly thermal conductive filler such as alumina or boron nitride is added as an additive exhibiting high thermal conductivity is used. When a resin having a high thermal conductivity is adopted, the coil 10 and the litz wire 12 constituting the coil 10 are connected between the wires 14 and between the first unit litz wires 16 and between the wires 14 and the fastening band. 22 and the surrounding band 24, and further, between the first unit litz wire 16 and the fastening band 22 and the surrounding band 24, a cured resin 20 having a high thermal conductivity, that is, a high heat dissipation property is filled without any gap. There is. Therefore, the coil 10 to be formed and the litz wire 12 constituting the coil 10 are filled with the hardened resin 20 having high thermal conductivity, that is, high heat dissipation, without any gaps, and the outer periphery thereof is also made of the hardened resin 20 having high heat dissipation. Since the coil 10 is covered with the hardened wrapping band 24, the entire coil 10 has high thermal conductivity, that is, heat dissipation.

  Next, a method for manufacturing the coil 10 will be described. 3 to 9 are views for explaining the manufacturing method of the coil 10, and are views showing states in respective intermediate steps of the manufacturing process. 3A and 3B are views showing a state of an intermediate step in the manufacturing process of the litz wire 12 which constitutes the coil 10. FIG. 3A is a perspective view and FIG. 3B is a sectional view. 43 is a view showing a state of an intermediate step in the manufacturing process of the litz wire 12 constituting the coil 10, FIG. 4 (a) is a perspective view, and FIG. 4 (b) is a sectional view. FIG. 5 is a diagram showing a state in the middle of the manufacturing process of the litz wire 12 constituting the coil 10. FIG. 5 (a) is a perspective view, and FIGS. 5 (b) and 5 (c) are sectional views. .

  First, as shown in FIGS. 3A and 3B, a twisted litz wire 30a (litz wire) is prepared. The twisted litz wire 30a is created by twisting the element wires 14 to create a first unit litz wire 16 and then twisting the first unit litz wire 16 together. The twisted litz wire 30a is hardened with the curing resin 20 and corresponds to the second unit litz wire 18.

  Next, as shown in FIGS. 4 (a) and 4 (b), the twisted litz wire 30a is wrapped around a binding band 22 to bind the litz wire 30a to form a binding litz wire 30b (litz wire). To do. The binding band 22 is wound around the twisted litz wire 30a so as to form a gap. In this state, the twisted litz wire 30a is exposed from the gap between the wound fastening bands 22. Here, since the binding band 22 is, for example, an aramid paper tape, it cannot pass through a resin solution described later.

  Next, as shown in FIGS. 5A and 5B, the bandage litz wire 30c (litz wire) is formed by winding the binding litz wire 30b around the non-woven tape 32. In this case, the nonwoven fabric tape 32 is wound around the securing litz wire 30b so that no gap is generated between the unwound nonwoven fabric tapes 32. The non-woven tape 32 can penetrate and permeate the resin liquid 38 described later.

  Here, the nonwoven fabric tape 32 contains a curing accelerator for the resin liquid 38 described later. Examples of the curing accelerator include amines, imidazoles, phosphines, DBU (1,8-diazabicyclo (5.4.0) undecene-7) and organic acid salts thereof, ammonium or phosphonium compounds, and the like.

  The non-woven tape 32 has sufficient strength to secure the twisted litz wire 30a, that is, to prevent the strand 14 and the first unit litz wire 16 from unraveling. In this case, the binding of the twisted litz wire 30a by the binding band 22 can be omitted. That is, as shown in FIGS. 3 (a) and 3 (b), the wound litz wire 30a is wound around the twisted litz wire 30a without a gap, so that the bandage litz wire 30d shown in FIG. Lines) can be formed. In this case, since the fastening by the fastening band 22 can be omitted, the process can be simplified and the manufacturing cost can be reduced. In addition, in the coil 10 and the litz wire 12 constituting the coil 10 in this case, the circumference of the second unit litz wire 18 is covered with the surrounding band 24, and the second unit litz wire 18 and the surrounding band 24 are secured with each other. The belt 22 does not exist. Other configurations are the same.

  Next, as shown in FIG. 6, the bandage litz wire 30c is wound around the wound core material 34 to form the bandage litz wire 30c in a coil shape. The wound core material 34 is made of, for example, wood. The wound litz wire 30c is wound around the wound core material 34 and is formed into a coil shape to form a coil 10b as shown in FIG.

  Next, after removing the coil 10b from the wound core material 34, as shown in FIG. 7, the coil 10b is immersed in a resin container 36 filled with a resin solution 38. By placing the resin container 36 in a space having a pressure lower than the atmospheric pressure, the filling of the resin liquid 38 into the coil 10b is promoted. Here, as described above, the nonwoven fabric tape 32 can allow the resin liquid 38 to pass therethrough. Further, the binding band 22 is wound around the twisted litz wire 30a so that a gap G is formed therebetween as shown in FIG. Therefore, the resin liquid 38 permeates the non-woven tape 32 and enters the inside of the bandage litz wire 30 c, and further passes through the gap G of the wound lashing band 22 to form the first unit litz wire 16 and the wire 14. Infiltrate in between. As a result, between the first unit litz wire 16 or the wire 14 inside the second unit litz wire 18, and further between the binding band 22, the non-woven tape 32 and these wire 14, the second unit litz wire 18, etc. The space is filled with the resin liquid 38 without any gap.

  Here, as described above, the nonwoven fabric tape 32 contains the curing accelerator for the resin liquid 38. The coil 10b is dipped in the resin solution 38 with this curing accelerator, and after the resin solution 38 has sufficiently penetrated into the nonwoven fabric tape 32 and the bandage litz wire 30c, the resin solution 38 in the nonwoven fabric tape 32 reacts with the curing accelerator. Harden. As a result, the wrapping band 24 cured by the resin is formed as shown in FIG. 8 described later. Here, since the curing accelerator is contained only in the non-woven tape 32, only the resin liquid 38 in the non-woven tape 32 part is cured, and the resin liquid 38 inside the non-woven tape 32 is not cured and remains uncured. Will remain. That is, the inner region between the first unit litz wire 16, the strand 14 and the lashing band 22 inside the second unit litz wire 18 and covered with the non-woven fabric tape 32 is the resin solution before curing. 38 or uncured resin 40. The coil in this state is referred to as a coil 10d, and the litz wire forming the coil is referred to as a bandage litz wire 30e. As shown in FIG. 8, the bandage litz wire 30e that constitutes the coil 10d is filled with the uncured resin 40 between the wires 14 inside it and between the first unit litz wires 16 and the outer periphery of the resin. It is in a state of being covered with the non-woven tape 32 cured by the liquid 38, that is, the wrapping band 24.

  Next, FIG. 9 shows the coil 10d in this state taken out from the resin container 36. The structure of the bandage litz wire 30e constituting the coil 10d is shown in FIG. 8 as described above. FIG. 8 shows a sectional structure of a portion B in FIG. At this time, the bandage litz wire 30e that constitutes the coil 10d is covered with the bandage 24 that is hardened with the resin liquid 38, as described above. Therefore, even when the coil 10d is taken out from the resin container 36, the resin liquid 38 inside the coil 10d, that is, the uncured resin 40, can be prevented from leaking to the outside, and the inside covered with the wrapping band 24 has no gap. The retained state is secured.

  Next, as shown in FIG. 9, the coil 10d is put into the thermal drying furnace 42. The entire coil 10d is thermally dried by the heat drying oven 42, whereby the uncured resin 40 of the coil 10d is cured. At the same time, the hardening of the wrapping band 24 is promoted. The coil 10 shown in FIG. 1 can be manufactured through the above steps.

  In the step shown in FIG. 7, the reason why the curing accelerator is included only in the 32 parts of the non-woven tape and the resin liquid 38 in only this part is cured is as follows. It is assumed that the non-woven fabric tape 32 portion does not contain a curing accelerator for the resin liquid 38. In this case, even if the coil 10b is dipped in the resin liquid 38 in the resin container 36, the resin liquid 38 in the portion of the non-woven tape 32 does not cure. When the coil 10 is taken out of the resin container 36 in this state, the non-woven tape 32 allows the resin liquid 38 to pass therethrough, so that the uncured resin 40 in the coil 10 passes through the non-woven tape 32 and leaks to the outside. Therefore, when the resin liquid 38 is cured in the heat drying furnace 42 in this state, the cured resin 20 is lost in the inside of the litz wire 12 that constitutes the coil 10, and the wire 14, the first unit litz wire 16, and the second A gap is formed between the unit litz wire 18, the fastening band 22, the surrounding band 24, and the like. If such a gap exists, the insulation of the coil 10 will deteriorate.

  On the other hand, in order to cure the resin liquid 38 when the non-woven tape 32 does not contain a curing accelerator, the resin liquid 38 is cured by heating the resin container 36 with the coil 10 placed therein. . However, in this case, the resin liquid 38 is hardened together with the resin container 36 having the coil 10 therein, and these are integrated together with the resin container 36, so that the coil 10 cannot be taken out. Further, the hollow resin in the center of the coil 10 is filled with the hardened resin, and the hollow is filled with the hardened resin. For the above reasons, the non-woven tape 32 is made to contain a curing accelerator so that the resin liquid 38 is cured only at this portion. That is, the non-woven fabric tape 32 becomes the wrapping band 24 cured by the resin by including the curing accelerator therein, the coil 10b is immersed in the resin container 36 filled with the resin liquid 38, and the resin liquid 38 is filled inside. When impregnated, it has a function of maintaining a state in which the resin liquid 38 is filled in the coil 10b without any gap. As a result, there is no gap between the wire 14, the first unit litz wire 16, the second unit litz wire 18, the fastening band 22 and the surrounding band 24 inside the coil 10, and the coil 10 having improved insulation can be obtained. it can.

The coil 10 according to the above-described embodiment has the following effects.
The coil 10 of the embodiment and the litz wire 12 constituting the coil 10 have a structure in which the spaces between and around the wires 14 are filled with the cured resin 20 without any gaps and molded. As a result, the insulating property of the coil 10 is improved, and even when the coil 10 is used in a high frequency electric device, excellent insulating property is achieved.

  Further, in the coil 10 and the litz wire 12 constituting the coil 10, the strands 14, the first unit litz wire 16, the second unit litz wire 18, the lashing band 22, and the surrounding band 24 are integrally formed by the curing resin 20 and have a clearance. It is hardened without a solid and has a three-dimensionally fixed structure. That is, the coil 10 and the litz wire 12 constituting the coil 10 have a configuration in which the spaces between the wires 14 and their peripheries are filled with the cured resin 20 without gaps and then hardened and molded. As a result, in the coil 10, generation of gaps and peeling voids is suppressed, and excellent insulation is achieved.

  The coil 10 of the embodiment and the litz wire 12 constituting the coil 10 are covered with a surrounding band 24 made of a non-woven fabric tape 32 cured with a resin. Thereby, the insulation between the litz wires 12 is improved and the mechanical strength of the coil 10 is improved.

  In the coil 10 of the embodiment and the litz wire 12 constituting the coil 10, a resin having a high thermal conductivity, that is, a heat dissipation property may be adopted as the curing resin 20, that is, the resin liquid 38 used for the coil 10. In this case, since the coil 10 has excellent heat dissipation, damage to the coil 10 and the like can be suppressed even if abnormal heat is generated in the coil 10.

  According to the method for manufacturing the coil 10 of the embodiment, the nonwoven fabric tape 32 contains the curing accelerator for the resin liquid 38. With this curing accelerator, the coil 10b in the process of manufacturing is dipped in the resin liquid 38, and after the resin liquid 38 has sufficiently penetrated into the bandage litz wire 30c, the resin liquid 38 in the non-woven fabric tape 32 reacts with the curing accelerator and is cured. To do. As a result, the inner region of the coil 10 is filled with the uncured resin liquid 38, that is, the uncured resin 40, and the outer periphery thereof is covered with the nonwoven fabric tape 32 cured with the resin liquid 38, that is, the wrapping band 24. Become. That is, the outer periphery of the uncured resin 40 in the inner region of the coil 10 is covered with the wrapping band 24 that is hardened by the resin, and a state in which the uncured resin 40 is confined inside can be created. Accordingly, even if the coil 10 being manufactured is taken out from the resin container 36, the uncured resin 40 in the inner region of the coil 10 can be prevented from leaking out. This makes it possible to obtain the coil 10 and the litz wire 12 constituting the coil 10 having a configuration in which the spaces between and around the wire 14 are filled with the cured resin 20 without gaps and molded. From the above, for example, even when this is used in a high frequency electric device, the coil 10 having excellent insulation can be manufactured.

In the above description, an example in which a rectangular litz wire is used as the litz wire 12 according to the embodiment has been described as an example, but the invention is not limited to this. For example, a round litz wire may be used.
Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are also included in the invention described in the claims and the scope equivalent thereto.

  In the drawing, 10, 10b, 10c, 10d are coils, 12, 30a, 30b, 30c, 30d and 30e are Litz wires, 14 are strand wires, 20 is a cured resin (resin), 22 is a binding band, and 24 is an enclosure. A belt, 32 is a non-woven tape, 36 is a resin container, 38 is a resin solution (resin), 40 is an uncured resin (resin), and 42 is a heat drying oven.

Claims (6)

A bundle of conductive thin wires is a winding conductor molded with resin,
A non-woven fabric in which a tape having a property of not permeating a liquid resin is wound around the winding conductor with a space provided between the winding conductor and the winding conductor, and the circumference of the winding conductor is hardened by the resin. A coil made of the winding conductor , which is covered with the resin and is filled with the resin without gaps between the thin wires. The coil according to claim 1 , wherein a circumference of the winding conductor is wound with a tape having a property of not transmitting the resin before being hardened. The resin coil according to any one of the high thermal conductivity according to claim 1 or 2. The coil according to any one of claims 1 to 3 , wherein an additive exhibiting high thermal conductivity is added to the resin. A step of preparing a winding conductor in which conductive thin wires are bundled,
A step of winding the periphery of the winding conductor with a non-woven fabric containing a resin curing accelerator,
A step of spirally winding the winding conductor wound with the non-woven fabric into a coil shape;
A step of immersing the coil-shaped winding conductor in a liquid resin to impregnate the liquid resin;
Comprising a step of curing the resin by treating the winding conductor impregnated with the liquid resin in a heat drying oven ,
Manufacturing of a coil, which comprises a step of winding a winding around the conductor for winding with a tape having a property of not permeating a liquid resin at a predetermined interval before the step of winding the non-woven fabric containing a resin hardening accelerator. Method. The method for manufacturing a coil according to claim 5 , wherein an additive exhibiting high thermal conductivity is added to the resin.

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