JP2018207060A - Non-contact power feeding device, coil and manufacturing method for coil - Google Patents

Abstract

To provide a non-contact power feeding device, coil and manufacturing method for coil, capable of achieving thickness reduction and coil manufacture with high workability for specified performance.SOLUTION: The coil is formed by arranging, in plane, a pair of first and second conduction wires whose ends are connected with each other and which are parallel to each other and winding the wires in a spiral shape, and includes a crossing part formed by crossing mutual wires, of the first and the second conduction wires wound side by side, at one position in one turn.SELECTED DRAWING: Figure 1

Description

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

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

  The non-contact power supply technology has several tens of power transmission (primary side) planar coils provided so as to be embedded in the road surface of the power supply station and power reception (secondary side) planar coils 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 planar coil used for wireless power transmission is mainly formed by winding a litz wire (conducting wire) formed by twisting a plurality of thin enamel wires into a spiral shape.

  Since the power generated by this type of planar coil is proportional to the cross-sectional area of the conducting wire, the larger the wire diameter, the greater the power that can be obtained, but the relationship between the electric vehicle body bottom and road surface is the installation location. In some cases, the housing thickness (diameter or height) of the coil is limited.

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

  By the way, in the case of such a coil, in order to obtain a predetermined performance while taking measures for suppressing the generation of Joule heat due to induction of eddy currents (heat generation measures), 5 to 6 locations in one winding of a plurality of conducting wires. It is necessary to perform twisting (crossing lines).

JP 2008-87733 A

  In the case of a conventional coil in which a plurality of conductive wires are wound in a planar manner as described above, it is necessary to cross the wires at a large number of locations where the plurality of conductive wires are wound once to prevent heat generation. Since work such as rotating the bobbin or untwisting is sometimes required, the workability decreases as the number of places where the conductive wires intersect is increased.

  Accordingly, the present invention has been made to solve the above-described problems, and provides a non-contact power feeding apparatus, a coil, and a method for manufacturing the coil that are thin and have good workability in coil manufacture in order to obtain specified performance. With the goal.

  In order to achieve the above object, a coil according to an aspect of the present invention includes a pair of parallel first and second conductive wires whose ends are connected to each other and arranged in a plane so as to be spirally wound. The formed coil is characterized in that, among the first and second conducting wires wound side by side, one intersection portion where the wires intersect each other is provided in one winding.

  A non-contact power feeding device according to an aspect of the present invention includes a metal substrate, a magnetic core plate disposed on the substrate, and the coil disposed on the magnetic core plate.

  The coil manufacturing method according to one aspect of the present invention is a coil manufacturing method in which a pair of parallel first and second conducting wires whose ends are connected to each other are arranged in a plane and wound into a spiral shape. In the method, the step of winding the first and second conductive wires side by side and the intersecting portion where the lines intersect among the first and second conductive wires wound side by side are 1 And a step of providing one place in the winding.

  According to the present invention, it is possible to provide a non-contact power feeding device, a coil, and a method for manufacturing a coil that are thin and have good workability in obtaining specified performance.

The top view of the spiral coil (outside shape is substantially square shape) of one embodiment of this invention. The figure which expanded the part P of the coil of FIG. The figure which expanded a part of parallel winding as a comparative example. The frequency-AC resistance characteristic figure of the coil of this invention and the coil of a comparative example. Sectional drawing which shows the structure of the non-contact electric power feeder of one embodiment of this invention. The figure which shows Examples 1-3 and the comparative example 1 which confirmed the winding method and the effect with 15 coils. The figure which shows Examples 4-6 and the comparative example 2 which confirmed the winding method and the effect with 7 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 disposing a primary-side non-contact power transmitting device and a secondary-side non-contact power receiving device so as to face each other. The primary-side non-contact power transmission device that supplies power and the secondary-side non-contact power reception device that receives power include substantially the same elements in the coil portion. Although the other side will be described, it goes without saying that the other side is the same.

  As shown in FIG. 1, the coil 20 according to the present embodiment has a plan view of litz wires 22 and 23 as first and second energization wires connected at both ends by a pair of crimp terminals 21 and 24 in a plan view. They are manufactured (formed) by winding them side by side in a spiral. The ratio S2: S1 between the inner diameter S1 and the outer diameter S2 of the coil 20 is approximately 2: 1.

  This coil 20 is provided with one crossing portion A (see FIG. 2) where the wires intersect each other among the litz wires 22 and 23 wound side by side (part P). reference). This winding coil 20 is referred to as “parallel dislocation winding”. The intersection A may be referred to as a “dislocation location”.

  Since the coil 20 that is only spirally wound in a plane is scattered during transportation, the tape 20 is taped and fixed by winding an adhesive tape (not shown) around a plurality of locations according to the winding width of the coil 20, Prevents shape collapse.

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

  The litz wires 22 and 23 are a wire group formed by twisting a plurality of enamel wires into a bundle. In this example, the litz wires 22 and 23 are used. However, as the conductive wires other than the litz wires 22 and 23, for example, a conductor that is not covered with insulation (a wire made of copper or aluminum) or the outermost layer. A self-bonding line 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 generally composed of a crimp part and a fixing part provided with a fixing hole. The crimping part is constituted by a cylindrical metal member, and the two wire members are crimped and integrated by inserting and crimping the conductor parts 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, a part P of the coil 20 (see FIG. 1) is provided with an intersection A where the litz wires 22 and 23 intersect in a radial direction from the winding center of the coil 20. ing.

  That is, this coil 20 is provided with 8 intersections A as dislocations in 15 turns of the litz wires 22 and 23 paired in two. In addition, in this example, the intersection A is provided at eight places, more than half of the number of turns 15 of the entire coil, which is a pair of Litz wires 22 and 23, but other turns and winding methods. Also, the present invention is 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 may be increased or decreased.

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

  When the litz wires 22 and 23 are paired as one volume, the litz wires 22 and 23 may be wound with a certain gap therebetween. A coil that is wound with a certain gap between each turn is called “gap winding”.

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

  In this example, a plurality of crossing portions A are provided by changing the crossing 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 number (N1, N3, N5... N15) of skipping one turn, of which the N1 litz wires 22 and 23 and the N3 litz wires 22 and 23 The crossing directions are made different so that the crossing directions of the N3rd litz wires 22 and 23 and the N5th litz wires 22 and 23 are made different.

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

  Moreover, the parallel winding produced as a sample for comparison (comparative example) is a parallel winding of the total number of windings 15 of the litz wires 22 and 23 paired with two as shown in FIG. .

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

  Referring to FIG. 4 showing the measurement results, it can be seen that the parallel dislocation winding of the present invention has characteristics approximating that of the gap winding in a practical range of, for example, 85 kHz to 100 kHz. It can also be seen that the parallel winding of the comparative example has an AC resistance that 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, and a magnetic core plate 2 disposed on the upper surface of the substrate 1. And a coil 20 disposed on the upper surface of the magnetic core plate 2. Thereby, it can be set as the primary non-contact power transmission apparatus or the secondary non-contact power receiving apparatus, for example. Furthermore, in order to fix the position of the coil 20 in 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.
(First step: winding step)
In this first step, the litz wires 22 and 23 are wound side by side.

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

(Example)
In the above embodiment, the example in which the intersecting portion A is provided in one place every other turn in the 15 turns of the coil 20 is described, but the example of the winding method described above is an example, Hereinafter, several examples of winding methods and effects thereof will be described with reference to FIGS. 6 and 7.

  As shown in FIG. 6, with respect to the coil 20 having a total number of turns of 15, the first embodiment has intersections A at a total of 8 locations in the winding order N1, N3, N5, N7, N9, N11, N13, and N15. This is an example in which one crossing portion A is provided in every other winding described in the above embodiment, and the ratio of the portion where the crossing portion A is provided with respect to the total number of turns is 8/15 = 53. Since the effect on the characteristics at this ratio was equal to or better than that of the gap winding, it was considered effective (present).

  Example 2 is an example in which intersecting portions A are provided at a total of eight places in the winding order N4 to N11, and the intersecting portions A are collectively provided in the central portion in the winding width, and intersect with the entire number of turns. The ratio of the portion where the part A was provided was 8/15 = 53%, and the effect on the characteristic at this ratio was also equal to or better than that of the gap winding.

  Example 3 is an example in which intersections A are provided at a total of six places in the winding order N1, N3, N6, N9, N12, and N14, and one intersection A is provided in one turn almost every two turns. The ratio of the portion provided with the crossing portion A to the total number of turns is 6/15 = 43%, and the effect on the characteristics at this ratio is also effective because the effect equivalent to or better than the gap winding is 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 that are one less than Example 3. Yes, the ratio of the portion where the crossing portion A was provided with respect 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 the effect was not (no).

Next, an example of the coil 20 in which the total number of turns is about half that of the first to third embodiments will be described.
As shown in FIG. 7, for a coil 20 having a total number of turns of, for example, 7 turns, Example 4 is an example in which intersections A are provided at a total of 4 places in the winding order N1, N3, N5, N7. The crossing part A is provided in every other volume described in the form, and the ratio of the part where the crossing part A is provided with respect to the total number of turns is 4/7 = 57%. The effect on the characteristics of (2) was determined to be effective (existing) because an effect equivalent to or higher than that of the gap winding was obtained.

  Example 5 is an example in which intersecting portions A are provided at a total of three places in the winding order N3 to N5, and the intersecting portions A are collectively provided in the central portion in the winding width, and intersect with the entire number of turns. The ratio of the portion where the portion A was provided was 3/7 = 43%, and the effect on the characteristic at this ratio was also effective (present) because the same or better effect than the gap winding was obtained.

  Example 6 is an example in which crossing portions A are provided at a total of seven places in all winding orders N1 to N7. One crossing portion A is provided in one volume, and the crossing portion A with respect to the total number of turns. The ratio of the portion provided with 7 is 7/7 = 100%, and the effect on the characteristic at this ratio was also considered to be effective (present) because the effect equivalent to or better than the gap winding was obtained.

  Comparative Example 2 is an example in which crossing portions A are provided at a total of two locations of the winding order N1 at the beginning of winding and the winding order N7 at the end of winding, and the ratio of the portion where the crossing portion A is provided to the total number of turns is 2/7. = 33%, and the effect on the characteristics at this ratio was lower than that of the gap winding.

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

As described above, according to the non-contact power feeding device of the present embodiment, when winding a pair of litz wires 22 and 23 connected at both ends side by side, every other crossing portion A where the litz wires 22 and 23 intersect each other is wound. By providing one location in one roll, the specified performance can be obtained with the minimum number of dislocation locations while thinning the thickness of the coil itself 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 the coil that are thin in thickness and have good workability in coil manufacture in order to obtain specified performance.

In the present embodiment, the following effects can be obtained.
By providing the intersection A (dislocation location) that intersects (displaces) the Litz wires 22 and 23 during the winding of the coil 20, an increase in AC resistance at a low frequency can be suppressed.

  For example, it is easy to maintain the flatness of the coil 20 by providing dislocation locations every other turn so that the odd turns are dislocated and the even turns are not. Moreover, the effect that the winding speed of the coil 20 can be raised at the time of manufacture can be expected.

  One dislocation may be provided between one roll. It is desirable that the crossing portions A are not provided at different positions in one winding, but are in the same direction when viewed from the center of the planar 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.

  As a method of twisting the intersection A (dislocation location), the twist may be twisted in the same direction. However, by changing the intersection direction each time the dislocation is performed, that is, by reversing the intersection direction, the coil manufacturing apparatus side performs twisting back. It is not necessary to perform this, and it is possible to prevent only one of the litz wires 22 or the litz wires 23 of the parallel winding from being twisted.

  Although the embodiment of the present invention has been described above, the above embodiment is presented as an example, and is not intended to limit the scope of the invention. The above novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. The above-described embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Aluminum plate (board | substrate), 2 ... Magnetic core board, 20 ... Coil, 21, 24 ... Crimp terminal, 22, 23 ... Litz wire.

Claims (11)

A coil formed by winding a pair of first and second conductive wires parallel to each other whose ends are connected to each other, arranged in a plane and spirally wound,
Of the first and second conductive wires wound side by side, one coil is provided with an intersecting portion where the wires intersect each other.   The coil according to claim 1, wherein the intersecting portion is provided in the radial direction from the winding center of the coil.   3. The coil according to claim 1, wherein the intersecting portion is provided at a location that is 40% or more of the total number of turns of the coil in which the first and second energizing wires are paired as one turn. 4. .   The coil according to any one of claims 1 to 3, wherein a crossing direction of the crossing portion is changed for each crossing portion.   The coil according to any one of claims 1 to 4, wherein the intersection is provided every other turn. A metal substrate;
A magnetic core plate disposed on the substrate;
The non-contact electric power feeder which comprises the said coil of any one of the Claims 1 thru | or 5 arrange | positioned on the said magnetic core board. A manufacturing method of a coil formed by winding a pair of first and second conductive wires parallel to each other whose ends are connected to each other in a plane and wound in a spiral shape,
Winding the first and second conductive wires side by side;
A method of manufacturing a coil, comprising: providing a crossing portion where one of the first and second conducting wires wound side by side intersects each other in one winding.   The method for manufacturing a coil according to claim 7, wherein the intersecting portion is provided in a radial direction from a winding center of the coil.   9. The coil according to claim 7, wherein the crossing portion is provided at a location that is 40% or more of the total number of turns of the coil in which the first and second current-carrying wire pairs make one turn. Production method.   The coil manufacturing method according to claim 7, wherein a crossing direction of the crossing portion is changed for each crossing portion.   The method of manufacturing a coil according to any one of claims 7 to 10, wherein the intersection is provided every other turn.

Images