JP6785702B2 - Wires, coils and coil manufacturing methods - Google Patents

Description

The present invention relates to an electric wire for a coil used in a non-contact power feeding device or the like, a coil, and a method for manufacturing the coil.

In recent years, the power supply of electric vehicles has been changed from the contact type using a cable to the non-contact type using wireless power transmission technology.

The non-contact power supply technology consists of dozens of flat coils for power transmission (primary side) installed so as to be embedded in the road surface of the power supply station and flat coils for power reception (secondary side) provided at the bottom of the electric vehicle. This is a technology for supplying electric power to an electric vehicle by wirelessly transmitting electric power by facing each other at intervals of about cm.

Conventionally, a flat coil used for wireless power transmission is mainly formed by winding a litz wire formed by twisting a plurality of thin enamel wires in a planar spiral shape (see, for example, Patent Document 1).

In the case of this flat coil, it is necessary to leave a certain gap between the litz wires in order to suppress the eddy current (to prevent heating), and it is insulated for the purpose of interposing an insulating material between the litz wires. It is formed by winding an insulating thread as a material in parallel with a litz wire.

JP-A-2009-158598

In this way, in the conventional flat coil, an insulating thread is interposed between the litz wires to provide a gap, and a spacer member (insulating thread) for filling the width of the gap is required, resulting in high cost. There is a problem of becoming. Further, the conventional flat coil has low rigidity as a single coil, and there is a possibility that the coil shape may be deformed when the coil is handled.

Therefore, the present invention has been made to solve the above problems, and is a low-cost electric wire for a coil, a coil, and a low-cost coil wire, a coil, which can maintain a constant gap between wires without arranging a spacer member between the wires. An object of the present invention is to provide a method for manufacturing a coil.

In order to achieve the above object, the electric wire according to one aspect of the present invention is wound around an energized wire formed by twisting a plurality of metal wires and a direction intersecting the axis of the energized wire. It is provided with a fiber layer made of a heat-sealing filamentous member coated with the wire. The energizing wire is formed by twisting a plurality of metal wires. The fiber layer is formed by winding the heat-sealing filamentous member around the current-carrying wire in a direction intersecting the axis of the current-carrying wire.

The coil according to one aspect of the present invention is the above-mentioned electric wire spirally formed so as to leave a gap between the electric wires.

According to the present invention, it is possible to provide a low-cost electric wire for a coil, a coil, and a method for manufacturing a coil, which can maintain a constant gap between the wires without arranging a spacer member between the wires.

The cross-sectional view which shows the structure of the non-contact power feeding apparatus of one Embodiment of this invention. The plan view of the spiral coil (circular shape) of 1st Example. FIG. 2 is a cross-sectional view of an electric wire which is a main material of the coil of FIG. The figure which shows the fiber material used for forming the fiber layer of the electric wire surface of FIG. The figure which shows how the electric wire is put along the groove and weight is put, and the rattling of an electric wire is suppressed. The figure which shows the spiral coil (rectangle) of 2nd Example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
The non-contact power feeding device according to the present embodiment is configured by arranging a non-contact power transmitting device on the primary side and a non-contact power receiving device on the secondary side facing each other. In the non-contact power transmitting device on the primary side that supplies power and the non-contact power receiving device on the secondary side that receives power, the elements of the coil part are composed of almost the same elements, and here, one of them. The other side will be described, but it goes without saying that the same applies to the other side.

As shown in FIG. 1, for example, the non-contact power transmission device on the primary side is arranged on a substrate 1 such as an aluminum plate, a magnetic core plate 2 arranged on the upper surface of the substrate 1, and an upper surface of the magnetic core plate 2. The coil 10 is provided. Further, in order to fix the position of the coil 10 on the magnetic core plate 2, the upper surface of the magnetic core plate 2 may be coated with a mold resin or the like.

As shown in FIG. 2, an electric wire 11 such as a litz wire (metal wire) is used as the main material of the coil 10. The coil 10 is formed by winding an electric wire 11 in a circular spiral shape. The electric wires 11 are wound flat side by side with a gap at regular intervals.

As shown in FIG. 3, the electric wire 11 comprises a litz wire 13 (twisted wire group) formed by twisting a plurality of enamel wires 12 into a bundle, and a fiber layer 14 coated and formed around the litz wire 13. Have. The litz wire 13 (stranded wire group) has a substantially cylindrical shape in a bundled state. The enamel wire 12 is one of the insulating conductors in which the outer surface (periphery) of the copper wire (wire) 12a is insulated with the enamel layer 12b.

As shown in FIG. 4, the fiber layer 14, which is a coating covering the periphery of the litz wire 13 shown in FIG. 3, is a fiber material having a two-layer structure consisting of a sheath 32 portion of the outer cover and a core 33 portion inside the sheath 32. 34 is a bundle, and hereinafter, this bundle is referred to as a "heat-sealing thread 35" or a "filament-like member". The fiber layer 14 is formed by pressing the heat-sealing yarn 35 against the peripheral surface of the litz wire 13 to make it flat and winding it, or by heat-processing the fiber materials 34 to form the heat-sealing yarn 35. Is fixed.

That is, the fiber layer 14 is formed by winding a heat-sealing thread 35 around the litz wire 13 in the circumferential direction (direction intersecting the axis) of the litz wire 13, that is, the heat-sealing thread 35. Is wound flat around the litz wire 13. By winding the heat-sealing yarn 35 around the litz wire 13 while flatly overlapping the litz wire 13, the litz wire 13 does not come apart and the shape-maintaining force when bent can be enhanced.

The sheath 32 is made of a crystalline polyester resin having a melting point of, for example, 160 ° C. The core 33 is made of a high-viscosity polyester resin having a melting point of, for example, 250 ° C.

That is, each fiber material 34 constituting the heat-sealing thread 35 has a two-layer structure consisting of a resin core 33 and a resin sheath 32 formed around (outside) the core 33. The melting temperature of the sheath 32 is lower than that of the core 33.

The fiber material 34 having a two-layer structure of a sheath 32 and a core 33 having different melting points includes a combination of a high melting point polyester resin and a low melting point polyester resin, a combination of a polyethylene resin and a polypropylene resin, and a polyester resin and a polyethylene resin. A combination, further a combination of a polyester resin and a nylon resin (polyamide), etc. can be considered. That is, the fiber material 34 can be applied as long as the materials having different melting points are spun into a single fiber in the state of the core 33 and the sheath 32. Further, a mixed fiber yarn in which a plurality of fiber materials having different melting points are mixed may be used. By heating at a temperature at which the high melting point wire does not melt and the low melting point fiber material melts in a plurality of fiber materials having different melting points, the same as the fiber material 34 having a two-layer structure of the sheath 32 and the core 33 having different melting points. The effect can be obtained.

The electric wire 11 is wound by pressing the heat-sealing thread 35 from the circumferential direction (direction intersecting the axis) of the litz wire 13 against the outer peripheral portion of the litz wire 13 while applying tension to form a flat shape. Is.

The heat-sealing yarn 35 is wound flat, then heated at 160 ° C. or higher to melt the sheath 32 portion of the outer cover, and then solidified by cooling to form the flat fiber layer 14.

In the fiber layer 14, only the sheath 32 portion melts and adheres to each other when heated, and the core 33 portion in the sheath 32 portion does not melt, so that it becomes a tape shape (strip shape). Therefore, when the fiber layer 14 is peeled off, the thread 35 can be neatly peeled off in a tape shape in units of winding. Further, after the fiber layer 14 is peeled off, no residue of the fiber layer 14 remains on the litz wire 13 inside the fiber layer 14, so that the state of the litz wire 13 before processing is the same. As a result, for example, termination processing can be easily performed.

Hereinafter, a method for manufacturing the coil 10 will be described.
As the electric wire 11, for example, a litz wire 13 is used. Further, the electric wire 11 may be, for example, a conductor (a wire made of copper or aluminum) which is not insulated and coated, in addition to the litz wire 13.

(1st process: winding process)
In this first step, a bobbin winder is used. This device uses the conventional one. A bobbin wound with a heat-sealing thread 35 is set in the bobbin.

In this first step, the heat-sealing yarn 35 is pressed against the outer peripheral portion of the litz wire 13 while applying tension to form a flat shape and wound while overlapping. Thereby, one covered electric wire 11 can be created.

As the heat-sealing thread 35, for example, a commercially available thread-like member of Melset "280T48" or 250 denier (280 decitex) was used. Melset is a registered trademark.

In addition to this, by changing the bobbin winding conditions, a heat-sealing yarn 35 of 250 denier (280 decitex) or more and 3000 denier (3340 decitex) or less can be used.

(Second step: heating step)
In this second step, a heater (see FIG. 5) is used to process the electric wire 11 produced in the first step into a spiral shape to manufacture the coil 10.

That is, as shown in FIG. 5, the heater supplies electric power to the molds 61 and weights 62 that are vertically opposed to each other, the heaters 67 that heat the molds 61 and / or the weights 62, and the heaters 67. It is equipped with a power supply 68.

The mold 61 is provided with a spiral groove 63. The groove 63 is provided with a width and a depth into which the electric wire 11 can be fitted.

That is, the electric wire 11 is crawled into the spiral groove 63 and fitted, and the weight 62 is arranged to suppress the fine rattling of the spirally molded electric wire 11, and the heat-sealing thread is heated by a heater. A spiral coil in which a heat-sealing thread 35 forms a coating of a fiber layer 14 in which a heat-sealing thread 35 is fixed in a tape shape around an electric wire 11 by heating to the melting temperature of the sheath 32 of 35 to melt and then cooling. 10 (see FIG. 2) is manufactured. Further, when performing the heat processing, a pressurizing machine (not shown) may be used to positively pressurize. The thickness of the formed spiral coil can be reduced by applying pressure with a pressurizing machine during heat processing.

After that, the magnetic core plate 2 is arranged on the upper surface of the substrate 1 such as an aluminum plate, and the coil 10 is arranged on the upper surface of the magnetic core plate 2 to manufacture the non-contact power feeding device shown in FIG. be able to.

As described above, according to the non-contact power feeding device of the present embodiment, heat fusion is performed around the litz wire 13 formed by twisting a plurality of enamel wires 12 in the circumferential direction (direction intersecting the axis) of the litz wire 13. By winding and covering the sex thread 35, it becomes possible to flexibly route the electric wire 11, and the electric wire 11 is fitted into a spiral groove 63 having gaps between the wires at equal intervals to heat the electric wire 11. After that, by cooling, the coil 10 whose shape can be maintained can be manufactured without interposing a spacer such as an insulating resin. Therefore, a constant gap is formed between the wires without arranging a spacer member between the wires. It is possible to provide a method for manufacturing an electric wire, a coil, and a coil for a coil for low-cost non-contact power transmission or non-contact power reception that can be held.
In addition, in the spiral coil formed tightly without providing a gap between the wires, the shape can be further maintained.

Further, in the present embodiment, the following effects can be obtained.
By winding the heat-sealing thread 35 around the litz wire 13, it can be cheaper than using a self-bonding wire having a fusion film formed on the outer periphery of the enamel layer 12b. Further, in the self-bonding wire, the outer diameter of the litz wire 13 is increased by providing a fusion film, but in the present embodiment, the heat-sealing thread 35 is formed into a flat shape on the outer circumference of the litz wire 13. A spiral coil having a thickness thinner than that of the self-bonding wire can be produced by simply winding the coil.

Since the heat-sealing yarn 35 in the unheated state is not fixed as it is, the flexibility of the litz wire 13 is maintained, so that it is more flexible than, for example, winding a resin tape material made of a thermosetting resin. In addition to the properties, the moldability of the coil is improved.

Since the spool machine can use the existing equipment, the capital investment is minimal.

Even if the shape of the coil 10 is such that a gap is provided between the adjacent electric wires 11, the coil 10 can obtain rigidity by being heated and the fiber layer 14 covering the litz wire 13 is fixed, so that the coil 10 can be handled. It becomes easy to maintain the shape of the time.

Since the film of the litz wire 13 does not use a resin or the like that fuses the litz wire 13 itself, even after heating to fix the shape of the coil 10, the fixed fiber layer 14 is peeled off before processing. It can be easily returned to the litz wire 13 of the above, and termination processing can be easily performed.

In the above embodiment, the outer shape of the spiral coil 10 is circular, but in addition to this, by changing the arrangement and shape of the groove 63 of the mold 61, for example, as shown in FIG. 7, the outer shape is rectangular. A coil 20 or a spiral coil having an elliptical outer shape (not shown) can be easily manufactured.

Although the embodiments of the present invention have been described above, 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 embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Aluminum plate (board), 2 ... Magnetic core plate, 10, 20 ... Coil, 11 ... Electric wire, 12 ... Enamel wire, 13 ... Litz wire (energized wire), 14 ... Fiber layer, 32 ... Sheath, 33 ... Core , 34 ... Fiber material, 35 ... Bundle of fiber material (heat-sealing thread), 61 ... Mold, 62 ... Weight, 63 ... Groove, 67 ... Heater, 68 ... Power supply.

Claims (10)

An energizing wire formed by twisting multiple metal wires and
An electric wire characterized in that the current-carrying wire is provided with a heat-sealing thread wound in the circumferential direction thereof. Each fiber material constituting the heat-sealing yarn forms a two-layer structure of a resin core portion and a resin sheath portion formed on the outside of the core portion.
The electric wire according to claim 1, wherein the melting temperature of the sheath portion is lower than that of the core portion. The electric wire according to claim 1, wherein the heat-sealing yarn is formed by mixing two types of fiber materials having different melting points. The invention according to any one of claims 1 to 3, wherein the bundle of the fibrous material constituting the heat-sealing yarn is 250 denier (280 decitex) or more and 3000 denier (3340 decitex) or less. Electric wire. A coil obtained by forming the electric wire according to any one of claims 1 to 4 into a flat spiral shape. The coil according to claim 5, wherein a gap is provided between the wires. The coil according to claim 5 or 6, wherein the outer shape is circular or polygonal. With a metal substrate
The magnetic core plate arranged on the substrate and
A non-contact power feeding device including the coil according to any one of claims 5 to 7, which is arranged on the magnetic core plate. The electric wire according to any one of claims 1 to 4 is fitted into a spiral groove, heated to the melting temperature of the heat-sealing yarn, and then cooled to surround the energizing wire. A method for manufacturing a coil, which comprises forming a fixed fiber layer. The method for manufacturing a coil according to claim 9, wherein the electric wire is heated while being pressurized.

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