JP6971062B2 - Manufacturing method of coil for non-contact power supply device and coil for non-contact power supply device - Google Patents

Description

The present invention relates to a coil for a non-contact power feeding device and a method for manufacturing a coil for a non-contact power feeding device.

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 includes 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) installed at the bottom of the electric vehicle. It is a technology to supply power to an electric vehicle by wirelessly transmitting electric power by facing each other at intervals of about cm.

Conventionally, a planar coil used for wireless power transmission is mainly formed by winding a litz wire (energized wire) formed by twisting a plurality of thin enamel wires in a plane spiral shape.

Since the generated power of this type of flat coil is proportional to the cross-sectional area of the current-carrying wire, the larger the wire diameter, the larger the power that can be obtained, but the bottom of the body of the electric vehicle or the road surface becomes the installation location. Therefore, there are cases where the accommodation thickness (diameter or height) of the coil is limited.

For this reason, in recent years, a coil has been proposed in which a plurality of thin current-carrying wires are arranged and wound in a plane so as to obtain a cross-sectional area equivalent to one thick current-carrying wire (for example, Patent Document). 1).

By the way, in the case of such a coil, in order to obtain the predetermined performance while taking measures to suppress the generation of Joule heat due to the induction of eddy current (heat generation measures), 5 to 6 places in one winding of a plurality of energized wires. It is necessary to carry out a twist (crossing the lines).

Japanese Unexamined Patent Publication No. 2008-87733

In the case of a conventional coil in which a plurality of energized wires are wound in a plane in this way, it is necessary to cross the wires at many points in the winding of the plurality of energized wires in one round in order to prevent heat generation. Occasionally, it is necessary to rotate the bobbin or untwist it, so the more points where the current-carrying wires intersect, the lower the workability.

The present invention has been made to solve the above problems, a non-contact power feeding device coil good workability thickness is thin and the coil produced in obtaining specified performance and the non-contact power feeding device coil The purpose is to provide a manufacturing method for the above.

In order to achieve the above object, the coil for a non-contact power feeding device according to one aspect of the present invention is formed by forming a plane of a pair of first and second litz wires parallel to each other with their ends connected to each other. It is a coil for a non-contact power feeding device formed by winding 7 or more turns in a spiral shape side by side, and among the energizing wires composed of the first and second litz wires that are wound side by side, the wires intersect with each other. The crossing portion is provided at one place in one winding, and the ratio of the portion where the crossing portion is provided to the total number of turns of the non-contact power feeding device coil is 43% or more and 57% or less, and the crossing portion is provided. The coil for the non-contact power feeding device is provided so as to be aligned in the radial direction from the winding center, and the intersection direction of the intersection is changed for each intersection .

In the method for manufacturing a coil for a non-contact power feeding device according to one aspect of the present invention, energizing wires composed of a pair of first and second litz wires connected to each other and having their ends connected to each other are arranged in a plane in a spiral shape. A method for manufacturing a coil for a non-contact power feeding device formed by winding 7 or more turns in a coil, wherein the current-carrying wires made of the first and second litz wires are wound side by side, and the first coil is wound side by side. Of the current-carrying wires composed of the first and second litz wires , an intersection where the wires intersect with each other is provided at one position in one winding, and the intersection is provided with respect to the total number of turns of the non-contact power feeding device coil. a step you percentage of sites having a 43% or more 57% or less, the intersection, a step of providing aligned radially from the winding center of the non-contact power feeding device coil, the cross direction of the intersection Is provided for each of the intersections .

According to the present invention, it is possible to provide a manufacturing method for the provision of small thickness in order to obtain the performance and good workability when producing the non-contact power feeding device coil and the non-contact power feeding device coil.

The plan view of the spiral coil (the outer shape is substantially square) of one Embodiment of this invention. The figure which enlarged the part P of the coil of FIG. An enlarged view of a part of the parallel winding as a comparative example. Frequency-AC resistance characteristic diagram of the coil of the present invention and the coil of the comparative example. The cross-sectional view which shows the structure of the non-contact power feeding apparatus of one Embodiment of this invention. It is a figure which shows Example 1 to 3 and Comparative Example 1 which confirmed the winding method and effect with the coil of 15 windings. The figure which shows Example 4-6 and the comparative example 2 which confirmed the winding method and the effect with 7 winding coils.

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

(Embodiment)
The non-contact power feeding device 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 transmission 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, in the coil 20 according to the present embodiment, the litz wires 22 and 23 as the first and second energizing wires whose ends are connected by a pair of crimp terminals 21 and 24, respectively, are planarized. It is manufactured (formed) by winding it side by side in a spiral shape. The ratio S2: S1 of the inner diameter S1 and the outer diameter S2 of the coil 20 is approximately 2: 1.

Of the litz wires 22 and 23 wound side by side, the coil 20 is provided with an intersection A (see FIG. 2) where the wires intersect each other at one position in every other winding (part P). reference). The coil 20 of this winding method is referred to as "parallel dislocation winding". Further, the intersection A may be referred to as a "dislocation site".

Since the coil 20 that is simply wound in a spiral shape in a plane will be disassembled during transportation, adhesive tape (not shown) or the like is wrapped around a plurality of places according to the winding width of the coil 20 and fixed by taping. Prevents the shape from collapsing.

That is, both ends of the litz wires 22 and 23 are connected by a pair of crimp terminals 21 and 24, respectively, and the litz wires 22 and 23 are arranged in a substantially flat manner and wound in a spiral shape.

The litz wires 22 and 23 are a group of wire rods formed by twisting a plurality of enamel wires into a bundle. In this example, the litz wires 22 and 23 are used, but as the energizing wires other than the litz wires 22 and 23, for example, a conductor without insulation coating (a wire made of copper or aluminum) or an outermost layer may be used. A self-bonding wire provided with a self-bonding layer may be used.

The crimp terminal 21 is electrically connected to one end of the litz wires 22 and 23, and is roughly composed of a crimp portion and a fixing portion provided with a hole for fixing. The crimping portion is composed of a tubular metal member, and the two wire rods are crimped and integrated by inserting and crimping the conductor portions of the litz wires 22 and 23. The crimp terminal 24 is electrically connected to the other ends of the litz wires 22 and 23, and is the same as the crimp terminal 21.

As shown in FIG. 2, the intersection A where the litz wires 22 and 23 intersect is provided in a part P of the coil 20 (see FIG. 1) so as to be aligned in the radial direction from the winding center of the coil 20. ing.

That is, this coil 20 is provided with eight intersections A as dislocation points in a pair of two litz wires 22 and 23 with 15 turns of turns. In this example, the number of turns of the entire coil is 15 in which a pair of litz wires 22 and 23 is wound, and intersections A are provided at eight locations, which is more than half of the total number of turns. The present invention is also applicable. In this example, the total number of turns is an odd number, but it may be an even number, and the number of turns itself may be increased or decreased.

In this example, the litz wires 22 and 23 are spirally wound so that the outer shape is polygonal (when the outer shape is almost square as in this example, the corners of the four corners are rounded), and the coil 20 is formed. Is forming. In addition, the outer shape may be substantially circular.

When two litz wires 22 and 23 are wound in a pair, the winding may be performed with a constant gap between each winding. A coil wound in this way with a certain gap between each winding is called "gap winding".

When specified by the winding width of the coil 20, the intersection A is provided in a range exceeding half the winding width (S2-S1) / 4 of the winding width (S2-S1) / 2 of the entire coil 20. ..

A plurality of intersections A in this example are provided by changing the intersection direction of the pair of litz wires 22 and 23 for each winding. That is, in this example, the intersection A is provided at the odd-numbered (N1, N3, N5 ... N15) of the one-roll skip, but the N1st litz wire 22, 23 and the N3rd litz wire 22, 23 are provided. The crossing directions are different, and the crossing directions of the N3rd litz wire 22 and 23 and the N5th litz wire 22 and 23 are different.

Subsequently, the coil 20 (parallel dislocation winding in FIG. 2) and the comparative example (parallel winding and gap winding) of this embodiment will be described in comparison with reference to FIGS. 3 and 4.
The gap winding is a standard coil as a sample with a gap at a predetermined interval for each litz wire, and it is desirable that the performance (characteristics) of the coil of this gap winding be set as close as possible to this.

Further, as shown in FIG. 3, the parallel winding created as the sample to be compared (comparative example) is a parallel winding of all 15 windings of the litz wires 22 and 23 which are paired with two wires. ..

As the test conditions, for each of the above three samples (parallel dislocation winding, parallel winding, gap winding), the AC resistance was measured by connecting both ends of the coil to an existing LCR meter and changing the frequency from 0 to 200 kHz. It is a thing. In FIG. 5, the value at the position where the frequency is 0 (about 100 mΩ) is the DC resistance.

With reference to FIG. 4 of the measurement results, it can be seen that the parallel dislocation winding of the present invention has characteristics similar to those of the gap winding in the practical range, for example, in the band of 85 kHz to 100 kHz. It can also be seen that the AC resistance of the parallel winding of the comparative example deviates from the value of the gap winding.

As shown in FIG. 5, the non-contact power feeding device using the coil 20 (parallel dislocation winding) of the above embodiment includes a substrate 1 such as an aluminum plate, a magnetic core core plate 2 arranged on the upper surface of the substrate 1, and a magnetic core plate 2. It includes a coil 20 arranged on the upper surface of the magnetic core plate 2. Thereby, for example, it can be a non-contact power transmission device on the primary side or a non-contact power receiving device on the secondary side. Further, in order to fix the position of the coil 20 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.

Hereinafter, a method for manufacturing the coil 20 will be described.
(1st process: winding process)
In this first step, the litz wires 22 and 23 are wound side by side.

(Second step: intersection forming step)
In this second step, among the litz wires 22 and 23 wound side by side, the intersection A where the lines intersect with each other is provided at one place in every other winding. At this time, it is preferable that the intersection A is provided so as to be aligned in the radial direction from the winding center of the coil 20.

(Example)
In the above embodiment, an example in which the crossing portion A is provided at one position in every other winding of the 15 winding coils 20 has been described, but the example of the winding method shown above is an example. Hereinafter, some examples of winding methods and their effects will be described with reference to FIGS. 6 and 7.

As shown in FIG. 6, for the coil 20 having a total number of turns of 15, in the first embodiment, intersections A are provided at a total of eight locations in the winding order N1, N3, N5, N7, N9, N11, N13, and N15. This is an example, in which one intersection A is provided in every other volume described in the above embodiment, and the ratio of the portion where the intersection A is provided to the total number of turns is 8/15 = 53. %, And the characteristic effect at this ratio was considered to be effective (yes) because the effect equal to or higher than that of the Gyapu winding was obtained.

The second embodiment is an example in which the intersections A are provided at a total of eight locations in the winding order N4 to N11, and the intersections A are collectively provided at the central portion in the winding width, and the intersections with respect to the total number of turns are provided. The ratio of the portion where the portion A was provided was 8/15 = 53%, and the effect on the characteristics at this ratio was equal to or higher than that of the Gyapu winding, so that it was considered to be effective (yes).

Example 3 is an example in which intersections A are provided at a total of 6 locations in the winding order N1, N3, N6, N9, N12, and N14, and one intersection A is provided in one volume approximately every two volumes. The ratio of the portion where the intersection A is provided to the total number of turns is 6/15 = 43%, and the characteristic effect at this ratio is also effective because the effect equal to or higher than that of the gap winding was obtained ( Yes).

Comparative Example 1 is an example in which intersections A are provided at a total of five locations in the winding order N2, N5, N8, N11, and N14, and intersections A are provided at five locations, one less than in Example 3. Yes, the ratio of the portion where the intersection A was provided to the total number of turns was 5/15 = 33%, and the effect on the characteristics at this ratio was lower than the characteristics of the gap winding, so that there was no effect (no effect).

Subsequently, an example of the coil 20 in which the total number of turns is about half of that of Examples 1 to 3 will be described.
As shown in FIG. 7, for a coil 20 having a total number of turns of 7, for example, the fourth embodiment is an example in which intersections A are provided at a total of four locations in the winding order N1, N3, N5, and N7. The intersection A is provided at one place in every other volume described in the embodiment, and the ratio of the portion where the intersection A is provided to the total number of turns is 4/7 = 57%. As for the effect on the characteristics of, it was considered to be effective (yes) because the effect equal to or higher than that of the Gyapu winding was obtained.

The fifth embodiment is an example in which the intersections A are provided at a total of three locations of the winding order N3 to N5, and the intersections A are collectively provided at the central portion in the winding width, and the intersections with respect to the total number of turns are provided. The ratio of the portion where the portion A was provided was 3/7 = 43%, and the effect on the characteristics at this ratio was equal to or higher than that of the Gyapu winding, so that it was considered to be effective (Yes).

Example 6 is an example in which intersections A are provided at a total of seven locations in all winding orders N1 to N7, one intersection A is provided in one volume, and the intersection A with respect to the total number of turns. The ratio of the parts provided with was 7/7 = 100%, and the effect on the characteristics at this ratio was equal to or higher than that of the Gyapu winding, so it was considered to be effective (Yes).

Comparative Example 2 is an example in which the intersection A is provided at a total of two locations, the winding order N1 at the beginning of winding and the winding order N7 at the end of winding, and the ratio of the portions provided with the intersection A to the total number of turns is 2/7. = 33%, and the effect on the characteristics at this ratio was lower than the characteristics of the gap winding, so no effect (no effect) was set.

From the results of Examples 1 to 6 and Comparative Examples 1 and 2 above, it was found that the effect was obtained in the range where the ratio of the portion provided with the intersection A to the total number of turns exceeded 40%. That is, it is preferable to provide the intersection A at a position of 40% or more of the total number of turns of the coil, which is a pair of litz wires 22 and 23.

As described above, according to the non-contact power feeding device of the present embodiment, when the pair of litz wires 22 and 23 connected at both ends are wound side by side, every other winding portion A where the litz wires 22 and 23 intersect is wound. By providing one place in one winding, it is possible to obtain the specified performance with the minimum number of dislocation points while reducing the thickness of the coil itself by using the thin litz wires 22 and 23.
That is, it is possible to provide a non-contact power feeding device, a coil, and a method for manufacturing a coil, which are thin in thickness and have good workability in coil manufacturing in order to obtain specified performance.

Further, in the present embodiment, the following effects can be obtained.
By providing a crossing portion A (dislocation location) at which the litz wires 22 and 23 are crossed (dislocated) in the middle of winding the coil 20, it is possible to suppress an increase in AC resistance at a low frequency.

For example, the flatness of the coil 20 can be easily maintained by providing the dislocation points every other turn so that the odd-numbered turns are dislocated and the even-numbered turns are not dislocated. Further, it is expected that the winding speed of the coil 20 can be increased at the time of manufacturing.

One dislocation location may be provided between one roll. It is desirable that the intersections A are not provided at different positions in one winding, but are in the same direction when viewed from the center of the flat coil 20. That is, if the unevenness due to dislocation is aligned in one direction, it is excellent in that the coil 20 can be easily accommodated in the accommodation space on the side where the coil 20 is installed.

The intersection A (dislocation point) may be twisted in the same direction, but the coil manufacturing equipment can untwist by changing the intersection direction each time the dislocation occurs, that is, by reversing the intersection direction. It is not necessary to do this, and it is possible to prevent twisting only on one of the litz wires 22 or the litz wire 23 of the parallel winding.

Although the embodiments of the present invention have been described above, the above embodiments are presented as examples and are not intended to limit the scope of the invention. The above-mentioned novel embodiment can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. The above-described embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Aluminum plate (board), 2 ... Magnetic core plate, 20 ... Coil, 21, 24 ... Crimping terminal, 22, 23 ... Litz wire.

Claims (6)

A coil for a non-contact power feeding device formed by spirally arranging a pair of energizing wires consisting of a pair of first and second litz wires parallel to each other and winding seven or more turns in a spiral shape. ,
Of the energizing wires consisting of the first and second litz wires that are wound side by side, one intersection is provided in one winding where the wires intersect with each other.
The ratio of the portion provided with the intersection to the total number of turns of the non-contact power feeding device coil is 43% or more and 57% or less.
The intersection is provided so as to be aligned in the radial direction from the winding center of the non-contact power feeding device coil.
A coil for a non-contact power feeding device, characterized in that the crossing direction of the crossing portion is changed for each crossing portion. The coil for a non-contact power supply device according to claim 1, wherein the ratio of the portion provided with the intersection to the total number of turns of the coil for the non-contact power supply device is 43% or more and 53% or less. The coil for a non-contact power feeding device according to claim 1 or 2 , wherein the intersection is provided every other winding. A method for manufacturing a coil for a non-contact power feeding device, which is formed by winding seven or more windings of a pair of first and second litz wires parallel to each other connected to each other in a plane and spirally. And,
The step of arranging and winding the energized wires made of the first and second litz wires side by side,
Of the energizing wires consisting of the first and second litz wires that are wound side by side, one intersection is provided in one winding where the wires intersect with each other, and the entire coil for the non-contact power feeding device is provided. a step shall be the following 57% 43% or more the ratio of the portion provided with the intersection for the number of turns of,
A step of providing the intersection in a radial direction from the winding center of the non-contact power feeding device coil.
The process of changing the crossing direction of the crossing part for each crossing part,
A method for manufacturing a coil for a non-contact power feeding device. In the step of providing one intersection in one winding, the ratio of the portion provided with the intersection to the total number of turns of the non-contact power feeding device coil is 43% or more and 53% or less.
The method for manufacturing a coil for a non-contact power feeding device according to claim 4. The method for manufacturing a coil for a non-contact power feeding device according to claim 4 , wherein the intersection is provided every other winding.

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