WO2012098851A1

WO2012098851A1 - Resonance-coil holding device, resonance coil unit and non-contact type electric power transmission apparatus

Info

Publication number: WO2012098851A1
Application number: PCT/JP2012/000216
Authority: WO
Inventors: Makoto Hirayama
Original assignee: Yazaki Corporation
Priority date: 2011-01-18
Filing date: 2012-01-16
Publication date: 2012-07-26

Abstract

To provide a resonance-coil holding device, and a resonance coil unit, and a non-contact type electric power transmission apparatus, which can prevent surface discharge in low cost without increasing a size of a resonance coil, a coil bobbin of a resonance coil unit is provide with helical even surface portions fixing a plurality of single-turn wire portions of the resonance coil at intervals to each other, and a helical projecting ridge arranged between the helical even surface portions. The helical projecting portion is configured to have a surface distance between adjacent single-turn wire portions of a resonance coil fixed by the helical even surface portions with a length corresponding to voltage difference which is generated between each of the adjacent single-turn wire portions.

Description

RESONANCE-COIL HOLDING DEVICE, RESONANCE COIL UNIT AND NON-CONTACT TYPE ELECTRIC POWER TRANSMISSION APPARATUS

The present invention relates to a resonance-coil holding device holding a resonance coil, which transmits electric power to a mating coil and/or receives electric power from the mating coil by resonance phenomena, resonance coil unit including the resonance-coil holding device, and a non-contact type electric power transmission apparatus including the resonance coil unit.

At the present time, wireless (non-contact) electric power transmission technology, which requires no physical connection such as connector connection, is applied to make easy electric charging operation for charging a secondary battery (call simply battery) provided at an electric car.

As wireless electric power transmission technology, electromagnetic induction system by applying electromagnetic induction phenomena, electromagnetic wave transmission system by applying electromagnetic wave, and resonance transmission system by applying resonance phenomena are known. The resonance transmission system is a technology of transmitting electric power by supplying AC electric power to a transmit resonance coil, and making the transmit resonance coil and a receive resonance coil arranged correspondingly to the transmit resonance coil resonate through electromagnetic field, and can transmit large electric power of a few kW between points relatively spaced from each other.

When such wireless electric power transmission technology by resonance transmission system is applied for a system transmitting large electric power ranged from a few kW to several tens kW, for example a battery system of an electric car, high voltage is generated at an end or near end of a coil wire wound into cylindrical shape of the resonance coil at resonance condition as shown in Fig. 13. Thereby, dielectric breakdown between an earthed case for receiving the resonance coil and the coil may be occurred and electro-discharge spark is generated, and it is troublesome. Technology solving such problem is disclosed in Patent document 1.

A resonance coil 901 described in Patent document 1 includes a coil wire 910 and insulation resin 920 as shown Fig. 19. The coil wire 910 is wound in several turns into cylindrical shape. The insulation resin 920 is coated on the coil wire 910 so as to increase its thickness toward an end 910a of the coil wire 190a in a lengthwise direction of the coil wire 910. Thereby, dielectric strength at the end 910a of the coil wire 910 can be increased so as to prevent electro-discharge spark. The coil wire 910 of the resonance coil 901 is provided between single-turn wire portions of the coil wire 910 with a between-wire gap, so that electro-discharge spark between adjacent single-turn wire portions caused by dielectric breakdown can be prevented.

Such resonance coil 901 is wound spirally and held around an outer surface 940a of a coil bobbin 940 formed into a cylindrical shape with insulation resin so as to arrange a plurality of single-turn wire portions 915 at intervals to each other as shown in Fig. 20. The resonance coil 901 and the coil bobbin 940 are arranged together at the electric car or the charging apparatus.

Another resonance coil 901 is supported partially at several points along a circumference of a plurality of single-turn wire portions 915 by a plurality of ribs 950 formed into a band plate shape with insulation resin so as to arrange the plurality of single-turn wire portions at intervals to each other as shown in Fig. 21A. The resonance coil 901 and the ribs 950 are arranged together at the electric car or the charging apparatus. The rib 950 is formed by insulation resin into a dividable band plate to separate two parts in a widthwise direction thereof so as to have a plurality of fixing holes 953 with a diameter same as a diameter of the resonance coil 901, as shown in Fig. 21B. Each of the points along the circumference of the plurality of single-turn wire portions 915 is pressed fitted to each of corresponding fixing holes 953, so that the resonance coil 901 is held to keep the between-wire gaps between each single-turn wire portions.

Patent Document 1: Japan Patent Application Published No. 2010-73885

Objects to be solved

The resonance coil 901 is supported by the above coil bobbin 940 or the ribs 950 (that is resonance-coil holding device), so that an outer surface of a first single-turn wire portion is continued through on outer surface 940a of the coil bobbin 940 or the outer surface of the ribs 950 to an outer surface of another single-turn wire portion 915 adjacent to the first single-turn wire portion 915. Thereby, voltage generated between the single-turn wire portions may cause to generate surface discharge traveling over the outer surface of the 940a of the coil bobbin 940 or the surface of ribs 950. For preventing such surface discharge, a gap between single-turn wire portions 915 of the resonance coil 901 can be increased, so that the resonance coil 901 will be enlarged. For preventing the surface discharge, sealing by resin (that is resin mold), in which the resonance coil 901 is set in a mold frame and melted resin is poured therein, can be applied, so that manufacturing cost will be increased.

According to the above problems, an object of the present invention is to provide a resonance-coil holding device, and a resonance coil unit, and a non-contact type electric power transmission apparatus, which can prevent surface discharge in low cost without increasing a size of a resonance coil.

How to attain the object of the present invention

In order to overcome the above problems and attain the object, the present inventor studied a structure of a resonance-coil holding device which can prevent surface discharge while simultaneously a size and cost thereof can be decreased. As a result, it is found that surface discharge can be prevented by a way of providing a suitable surface distance corresponding to a voltage difference between each single-turn wire portions of the resonance coil, with a small size and low cost, and the present invention is completed.

In order to attain the object, a resonance-coil holding device according to claim 1 of the present invention is for holding a resonance coil, which transmits electric power to a mating coil or receives electric power transmitted from the mating coil by resonance phenomena, and is formed to have a plurality of single-turn wire portions; and includes a base member, coil fixing portions arranged at the base member so as to fix the plurality of single-turn wire portions of the resonance coil at intervals to each other, and surface distance extending portions arranged between the coil fixing portions arranged at the base member, wherein the surface distance extending portions are configured to have a shape selected among a projection shape, a recess shape, and combination shape of the projection shape and the recess shape, and to have a surface distance between respective adjacent single-turn wire portions corresponding to a voltage difference generated between the respective adjacent single-turn wire portions.

The resonance-coil holding device according to claim 2 of the present invention is characterized about the above invention claimed in claim 1 in that the surface distance extending portions are configured to have the surface distance between the adjacent single-turn wire portions corresponding to a maximum voltage difference among voltage differences respectively generated between each adjacent single-turn wire portions.

The resonance-coil holding device according to claim 3 of the present invention is characterized about the above invention claimed in claim 1 in that the surface distance extending portions are configured to have the surface distance at the center of the resonance coil longer than the surface distances at both ends of the resonance coil.

The resonance-coil holding device according to claim 4 of the present invention is characterized about the above invention claimed in

claim

1, 2 or 3 in that the resonance coil is formed into a cylindrical shape to have the plurality of single-turn wire portions, and the base member is formed into one of a cylindrical shape and a columnar shape, and the coil fixing portions are arranged helically at one of an outer surface of the base member and an inner surface of the base member, and the surface distance extending portions between the adjacent single-turn wire portions are arranged helically along the coil fixing portions at one of the outer surface of the base member and the inner surface of the base member.

The resonance-coil holding device according to claim 5 of the present invention is characterized about the above invention claimed in

claim

1, 2 or 3 in that the base member includes a plurality of base member pieces arranged at intervals to each other along a circumferential direction of the resonance coil, and the plurality of base member pieces includes respectively the coil fixing portions and the surface extending portions between the adjacent single-turn wire portions.

The resonance-coil holding device according to claim 6 of the present invention is characterized about the above invention claimed in

claim

1, 2 or 3 in that the resonance coil is formed spirally to have a plurality of turns; and the base member includes a first plate member and a second plate member, which are joined to each other; and the coil fixing portions include a first fixing portion arranged spirally at a joining surface of the first plate member and a second fixing portion arranged spirally corresponding to the first fixing portion at a joining surface of the second plate member so as to clamp each of the single-turn wire portions between the first fixing portion and the second fixing portion; and the surface distance extending portions between the adjacent single-turn wire portions include a first extending portion arranged spirally along the first fixing portion at the joining surface of the first plate member, and a second extending portion arranged spirally along the second fixing portion at the joining surface of the second plate member so as to be corresponding to the first extending portion and be engaged with the first extending portion with clearance.

In order to attain the object, a resonance coil unit according to claim 7 of the present invention includes a resonance coil, which is configured to have a plurality of single-turn wire portions so as to transmit electric power to a mating coil or receive electric power transmitted from the mating coil by resonance phenomena, and a resonance-coil holding device holding the resonance coil, and is characterized in that the resonance-coil holding device corresponds to the resonance-coil holding device according to one of claims 1-6.

In order to attain the object, a non-contact type electric power transmission apparatus according to claim 8 of the present invention includes a transmission resonance coil unit transmitting electric power by resonance phenomena and a reception resonance coil unit receiving electric power transmitted from the transmission resonance coil unit, and at least one of the transmission resonance coil unit and the reception resonance coil unit corresponds to the resonance coil unit according to claim 7.

Advantageous Effects of the Invention

According to the present invention claimed in claim 1, the base member is provided with the coil fixing portions so as to fix the plurality of single-turn wire portions of the resonance coil at intervals to each other, and surface distance extending portions arranged between the coil fixing portions, wherein the surface distance extending portions are configured to have a shape selected among a projection shape, a recess shape, and combination shape of the projection shape and the recess shape, and have the surface distance between respective adjacent single-turn wire portions corresponding to a voltage difference generated between the respective adjacent single-turn wire portions. Thereby, surface discharge can be prevented by the surface distance extending portions securing the surface distance between adjacent single-turn wire portions of the resonance coil, and the resonance coil can be miniaturized not to elongate a surface distance between adjacent single-turn wire portions. Thus, surface discharge can be prevented in low cost without resin mold and not to increase a size of the resonance coil.

According to the present invention claimed in claim 2, the surface distance extending portions are configured to have the surface distance between the adjacent single-turn wire portions of the resonance coil fixed by the coil fixing portions corresponding to a maximum voltage difference among voltage differences respectively generated between each adjacent single-turn wire portions. Thereby, surface discharge can be prevented by the surface distance extending portions securing the surface distance between adjacent single-turn wire portions of the resonance coil, and the resonance coil can be manufactured to have a same shape of the surface distance extending portions corresponding to the maximum voltage difference. Thus, surface discharge can be prevented not to increase a size of the resonance coil and in low cost without resin mold.

According to the present invention claimed in claim 3, the surface distance extending portions are configured to have the surface distance at the center of the resonance coil longer than the surface distances at both ends of the resonance coil. Thereby, in the resonance coil, which has a feature that a voltage difference generated between the adjacent single-turn wire portions at the center of the resonance coil is larger than that at both ends of the resonance coil, surface discharge can be prevented not to increase a size of the resonance coil and in low cost.

According to the present invention claimed in claim 4, the resonance coil is formed into a cylindrical shape to have the plurality of single-turn wire portions, and the base member is formed into one of a cylindrical shape and a columnar shape, and the coil fixing portions are arranged helically at one of the outer surface of the base member and the inner surface of the base member, and the surface distance extending portions between the adjacent single-turn wire portions are arranged helically along the coil fixing portions at one of the outer surface of the base member and the inner surface of the base member. Thereby, the resonance coil having the plurality of single-turn wire portions formed into a cylindrical shape can be held about a whole body thereof at one of the outer surface and the inner surface of the base member. Thus, the resonance coil can be securely held so as to maintain intervals between respective adjacent single-turn wire portions.

According to the present invention claimed in claim 5, the base member includes the plurality of base member pieces arranged at intervals to each other along the circumferential direction of the resonance coil, and the plurality of base member pieces includes respectively the coil fixing portions and the surface extending portions between the adjacent single-turn wire portions. Thereby, the resonance coil can be held partially at several points along the circumferences of the plurality of single-turn wire portions, so that amount of material for holding the resonance coil can be reduced not by holding the whole of the resonance coil. Thus, the resonance-coil holding device can be lightened about its weight and reduced about its cost.

According to the present invention claimed in claim 6, the base member includes the first plate member and the second plate member, which are joined to each other, and the coil fixing portions include the first fixing portion arranged spirally at the joining surface of the first plate member and the second fixing portion arranged spirally corresponding to the first fixing portion at the joining surface of the second plate member so as to clamp each of the single-turn wire portions between the first fixing portion and the second fixing portion, and the surface distance extending portions between the adjacent single-turn wire portions include the first extending portion arranged spirally along the first fixing portion at the joining surface of the first plate member, and the second extending portion arranged spirally along the second fixing portion at the joining surface of the second plate member so as to be corresponding to the first extending portion and be engaged with the first extending portion with clearance. Thereby, each of single-turn wire portions of the resonance coil having the plurality of spirally single-turn wire portions is fixed so as to be clamped between the first fixing portion and the second fixing portion, and partitioned by engaging the first extending portion and the second extending portion with each other. Thus, the resonance coil is clamped between the first plate member and the second plate member, which are previously formed, so that the resonance coil can be sealed simply in low cost so as to secure the surface distance. Therefore, electric shock by touching the resonance coil can be prevented.

According to the present invention claimed in claim 7, the resonance coil unit includes the resonance-coil holding device according to one of claims 1-6. The surface discharge can be prevented by securing the surface distance extending portion of the resonance-coil holding device in low cost without size increasing of the resonance coil.

According to the present invention claimed in claim 8, at least one of the transmission resonance coil unit and the reception resonance coil unit, which are included at the non-contact type electric power transmission apparatus, corresponds to the resonance coil unit according to claim 7. The surface discharge can be prevented by the surface distance between adjacent single-turn wire portions secured by the surface distance extending portion of the resonance-coil holding device of the resonance coil unit in low cost without size increasing of the resonance coil.

Fig. 1 is a perspective view of a resonance coil unit of a first embodiment according to the present invention; Fig. 2 is a cross-sectional view taken along an axial direction of the resonance coil unit shown in Fig. 1; Fig. 3A is an expanded cross-sectional view of helical projections (wedge shape) of the resonance coil unit shown in Fig. 1; Fig. 3B is an expanded cross-sectional view of a configuration (square shaped cross-section) of a first modification of the helical projections of the resonance coil unit shown in Fig. 3A; Fig. 3C is an expanded cross-sectional view of a configuration (half-round shape at a top end and rectangular shaped at a bottom end cross-section) of a second modification of the helical projections of the resonance coil unit shown in Fig. 3A; Fig. 3D is an expanded cross-sectional view of a helical groove replacing the helical projections of the resonance coil unit shown in Fig. 3A; Fig. 4 is a cross-sectional view taken along an axial direction of a modification of the resonance coil unit of the first embodiment; Fig. 5A is an expanded cross-sectional view of helical projections (wedge shape) of the resonance coil unit shown in Fig. 4; Fig. 5B is an expanded cross-sectional view of a configuration (rectangular shaped cross-section) of a first modification of the helical projections of the resonance coil unit shown in Fig. 5A; Fig. 5C is an expanded cross-sectional view of a configuration (half-round shape at a top end and rectangular shaped at a bottom end cross-section) of a second modification of the helical projections of the resonance coil unit shown in Fig. 5A; Fig. 5D is an expanded cross-sectional view of a helical groove replacing the helical projections of the resonance coil unit shown in Fig. 5A; Fig. 6 is a perspective view of a resonance coil unit of a second embodiment according to the present invention; Fig. 7A is a front view of a rib provided at the resonance coil unit shown in Fig. 6; Fig. 7B is a cross-sectional view taken along line II-II shown in Fig. 7A; Fig. 7C is a rear view of the rib shown in Fig. 7A; Fig. 7D is a side view of the rib shown in Fig. 7A; Fig. 8A is a front view of a rib provided at a modification of the resonance coil unit of the second embodiment; Fig. 8B is a cross-sectional view taken along line III-III shown in Fig. 8A; Fig. 8C is a rear view of the rib shown in Fig. 8A; Fig. 8D is a side view of the rib shown in Fig. 8A; Fig. 9 is a front view of a configuration (plate-shaped resonance coil) of a modification of the resonance coil unit shown in Fig. 6; Fig. 10 is a perspective view of a resonance coil unit of a third embodiment according to the present invention; Fig. 11A is a view of a first plate member viewed from a joining surface of the first plate member of the resonance coil unit shown in Fig. 10; Fig. 11B is a view of a second plate member viewed from a joining surface of the second plate member of the resonance coil unit shown in Fig. 10; Fig. 12A is an expanded cross-sectional view taken along line IV-IV shown in Fig. 10A; Fig. 12B is an expanded cross-sectional view of a configuration (combination shape of projection shapes and recess shapes) of a modification of a first extending portion and a second extending portion of the resonance coil unit shown in Fig. 9; Fig. 13 is a cross-sectional view of a modification of the resonance coil unit of the third embodiment according to the present invention; Fig. 14A is an expanded cross-sectional view of the resonance coil unit shown in Fig. 13; Fig. 14B is an expanded cross-sectional view of a configuration (combination shape of projection shapes and recess shapes) of a modification of a first extending portion and a second extending portion of the resonance coil unit shown in Fig. 14A; Fig. 15 is an illustration showing a structure of a wireless electric power transmission apparatus as an embodiment of a non-contact type electric power transmission apparatus according to the present invention; Fig. 16 is a block diagram of the wireless electric power transmission apparatus shown in Fig. 10; Fig. 17 is an illustration showing a basic theory of a resonance-type electric power transmission method; Fig. 18 is an illustration showing voltage distribution in resonant condition of a resonance coil; Fig. 19 is a partially expanded cross-sectional view of a resonance coil unit by prior art; Fig. 20 is a perspective view of an example of the resonance coil unit by prior art; Fig. 21A is a perspective view of other example of the resonance coil unit by prior art; and Fig. 21B is a view showing a rib of the resonance coil unit shown in Fig. 21A.

First Embodiment Of Resonance Coil Unit: A first embodiment of a resonance coil unit according to the present invention will be described with reference to drawings Figs. 1-5.

A resonance coil is utilized for transmitting electric power to a mating coil arranged corresponding to a coil, or receiving electric power transmitted from the mating coil. Such resonance coil is held by a resonance-coil holding device and mounted at an electric car or electric power charging apparatus.

The resonance coil unit 50 of the first embodiment according to the present invention includes a resonance coil 51 and a resonance-coil holding device 56 as shown in Figs. 1 and 2.

The resonance coil 51, for example, is a hollow helical coil having diameter D of 600mm and length L of 200mm by winding cupper wire of 5mm diameter a plurality of turns (n turns) cylindrically (solenoid). The resonance coil 51 is provided with a plurality of single-turn wire portions 55[1]-55[n] as a plurality of round portions (turns). Between one single-turn wire portion 55[k] of the resonance coil 51 and other single-turn wire portion 55[k+1] (k: from 1 to n-1) adjacent to the one single-turn wire portion (call simply "between single-turn wire portions 55"), a between-wires gap required to prevent dielectric breakdown (discharge in open air) between single-turn wire portions is provided. The same length of the between-wires gap is applied for each gap between single-turn wire portions 55. In this embodiment, a bare cupper wire is applied for the resonance coil 51. However, coated wire, on which insulation cover made of synthetic resin, such vinyl chloride resin or polyamide resin, is coated, can be applied.

Voltage distribution of the resonance coil 51 in resonant condition is shown in Fig. 18. Clearly shown in Fig. 18, a voltage difference per unit distance (that is incline in the graph) about the resonance coil 51 is larger at the center (that is the origin of graph) along a lengthwise of the resonance coil 51 and decreased toward the both ends along the lengthwise. Thus, voltage difference between single-turn wire portions of the resonance coil 51 wound helically into cylindrical shape is changed according to positions thereof, and physically, the voltage difference between single-turn wire portions 55 is increased toward the center in axial direction (that is direction along the length L) and decreased toward the both ends along the axial direction.

The resonance-coil holding device 56 includes a coil bobbin 57 as a base member, and a helical projecting ridge 58 as a surface distance extending portion between single-turn wire portions, and a helical even surface portion 59 as a coil fixing portion.

The coil bobbin 57 is formed by insulation synthetic resin into a cylindrical shape so as to make an outer diameter of the coil bobbin same as a diameter of the resonance coil 51. One end of the coil bobbin 57 is attached to a base plate K as a car body of the electric car or a flat plate of a case of the charge apparatus so as to extend vertically from the base plate K. The coil bobbin 57 may be formed into a columnar shape.

The helical projecting ridge 58 is arranged helically so as to surround an outer surface 57a of the coil bobbin 57. At the helical projecting ridge 58, a plurality of single-turn wire portions 58a (that is one single-turn wire portion corresponds to one turn) is arranged at even interval. The helical projecting ridge 58 is formed to have a same wedge-shaped cross-section over whole length thereof. Instead of this helical projecting ridge 58, a helical projecting ridge having a square-shaped cross-section 58A shown in Fig. 3B, or a helical projecting ridge having a half-round shape at a top end and square shaped at a bottom end cross-section 58B shown in Fig. 3C can be applied. The helical projecting ridge 58 can have a various shape within the object of the present invention.

According to this embodiment, the helical projecting ridge 58 is arranged. Instead of the helical projecting ridge 58, a helical groove 58D can be arranged helically so as to surround the outer surface 57a off the coil bobbin 57 as shown in Fig. 3D. The helical groove 58D is configured to have its width determined to secure a surface distance of a inner surface (for example, more than 1mm). The helical groove 58D can have a various cross-section within the object of the present invention as same as the helical projecting ridge 58. The surface distance described in this description is defined as a minimum distance between adjacent two conductive wires (adjacent single-turn wire portions) measured along a surface of insulation body.

The helical even surface portion 59 is a portion, which the outer surface 57a of the coil bobbin 57 is partitioned by the helical projecting ridge 58. The helical even surface portion 59 and the helical projecting ridge 58 are arranged helically along each other on the outer surface 57a of the coil bobbin 57. Thus, a helical portion 58a of the helical projecting ridge 58 and a helical portion 59a of the helical even surface portion 59 are arranged alternately along an axis direction (up-and-down direction in Fig. 2) of the coil bobbin 57. In other words, the helical projecting ridge 58 is provided between the helical even surface portion 59.

The helical even surface portion 59 is provided at a central portion in a direction of widthwise thereof over whole length thereof with a helical groove 59b which is formed into curved shape having arc cross-section so as to fit to a part of an outer surface of the resonance coil 51. A helical pitch between adjacent turns of the helical groove 59b is formed corresponding to a distance between adjacent single-turn wire portions of the resonance coil 51. The resonance coil 51 is wound along the helical groove 59b, so that the resonance coil 51 is fixed at the outer surface 57a of the coil bobbin 57. Thus, the helical even surface portion 59 fixes the plurality of single-turn wire portions 55 of the resonance coil 51 at intervals to each other.

A height from the outer surface 57a of the coil bobbin 57 and a vertex angle (that is shape) about the helical projecting ridge 58 are determined according to a maximum voltage difference among the voltage differences between each of adjacent single-turn wire portions 55, which value is calculated from the voltage distribution of the resonance coil 51 shown in Fig. 18. In other words, the helical projecting portion 58 is configured so as to have a surface distance between adjacent single-turn wire portions 55 corresponding to the length, which prevents surface discharge between each of the adjacent single-turn wire portions 55 when the maximum voltage difference is generated between the each of the adjacent single-turn wire portions 55, that is the length corresponding to the maximum voltage difference. For the surface distance, which surface discharge is not generated, a value determined under a predetermined safety standard (for example, IEC-International Electrotechnical Commission) is applied.

At the resonance-coil holding device 56, the resonance coil 51 is wound along the helical groove 59b of the helical even surface portion 59 arranged at the outer surface 57a of the coil bobbin 57. Thereby, each of single-turn wire portions 55 of the resonance coil 51 is fixed at intervals to each other on the outer surface 57a, and partitioned therebetween by the helical projecting ridge 58 so as to secure the surface distance between the adjacent single-turn wire portions 55.

According to the above embodiment, the coil bobbin 57 is provided with the helical even surface portion 59 fixing the plurality of single-turn wire portions 55 of the resonance coil 51 at intervals to each other, and the helical projecting ridge 58 arranged between the helical even surface portion 59. The helical projecting ridge 58 is configured to have the surface distance between each of the adjacent single-turn wire portions 55 which is determined according to a maximum voltage difference among the voltage differences generated between each of adjacent single-turn wire portions 55. Thereby, the surface discharge can be prevented by securing the surface distance between each of the adjacent single-turn wire portions 55 of the resonance coil 51. The helical projecting ridge 58 can be formed easily by the same wedge shape having the same cross-section over the whole length thereof as one reference (that is the maximum voltage difference). Therefore, surface discharge can be prevented in low cost by eliminating resin mold and without increase of the size of the resonance coil 51.

Furthermore, the helical even surface portion 59 and the helical projecting ridge 58 along the helical even surface portion 59 are arranged on the outer surface 57a of the coil bobbin 57 formed into cylindrical shape. Thereby, the resonance coil 51 formed into cylindrical shape by the plurality of single-turn wire portions can be held as a whole at the outer surface 57a of the coil bobbin 57 so as to secure the distance between each of the adjacent single-turn wire portions 55.

According to this embodiment, the resonance coil 51 is fixed on the outer surface 57a of the coil bobbin 57. The present invention is not limited in this, and the coil bobbin 57 can be provided at an inner surface 57b with similar members like the helical projecting ridge 58 and the helical even surface portion 59, and the resonance coil 51 may be fixed on the inner surface 57b. Thereby, the resonance coil 51 is not exposed and electric shock by touching the resonance coil 51 can be prevented. In the embodiment, the resonance coil unit is configured to wind the cylindrical-shaped resonance coil 51 on the cylindrical-shaped coil bobbin 57. The present invention is not limited in this, and the resonance coil unit can be configured to wind a square pipe-shaped resonance coil on a square pipe-shaped coil bobbin. The coil bobbin and the resonance coil can have a various shape within the object of the present invention.

As a modification of this embodiment, the helical projecting ridge 58 is arranged helically so as to surround an outer surface 57a of the coil bobbin 57. At the helical projecting ridge 58, a plurality of single-turn wire portions 58a (that is one single-turn wire portion corresponds to one turn) is arranged at even intervals. The voltage difference between the adjacent single-turn wire portions 55 of the resonance coil 51 is increased toward the center along the axial direction (that is the lengthwise L) of the resonance coil 51 and decreased toward the both ends along the lengthwise as shown in Fig. 18. Correspondingly, the helical projecting ridge 58 is configured to have the surface distance between each of the adjacent single-turn wire portions 55 according to the voltage difference generated between each of the adjacent single-turn wire portions 55.

Physically, the helical projecting ridge 58 is arranged helically so as to surround the outer surface 57a of the coil bobbin 57 along the outer surface thereof as shown in Fig. 4. The plurality of helical single-turn wire portions 58a (one single-turn wire portion is one turns) of the helical projecting ridge 58 is arranged at even intervals. The helical projecting ridge 58 is configured to have a wedge shape cross-section over the whole length thereof which is formed that a size (height) of the wedge shape is gradually smaller from the center of the coil bobbin along the axial direction (that is the center of the resonance coil 51 in the axial direction) toward the both ends thereof along the axial direction (that is the both ends of the resonance coil 51 in axial direction). In other words, the helical projecting ridge 58 is formed to have the surface distance between the adjacent single-turn wire portions 55 at the center along the axial direction of the resonance coil 51 longer than the surface distance between the adjacent single-turn wire portions 55 at the both ends along the axial direction (that is the both ends described in claims). Thus, the helical projecting ridge 58 is configured to increase gradually the surface distance between the adjacent single-turn wire portions 55 of the resonance coil 51 from the both ends along the axial direction toward the center along the axial direction.

The height from the outer surface 57a of the coil bobbin 57 and the vertex angle (that is shape) of the helical projecting ridge 58 is determined in accordance with the voltage difference generated between adjacent single-turn wire portions 55, which can be calculated from the voltage distribution of the resonance coil 51 shown in Fig. 18. In other words, the helical projecting ridge 58 is configured to have a surface distance between adjacent single-turn wire portions 55, which length is to prevent surface discharge between the adjacent single-turn wire portions 55, that is the length corresponds to the voltage difference, when the above voltage difference is generated between the adjacent single-turn wire portions. For the surface distance, which surface discharge is not generated, a value determined under a predetermined safety standard (for example, IEC-International Electrotechnical Commission) is applied.

In this embodiment, the helical projecting ridge 58 is configured to have the wedge cross-section shape over the whole length thereof as shown in Fig. 5A. Instead of such helical projecting ridge 58, a helical projecting ridge 58A having square cross-section shown in Fig. 5B or a helical projecting ridge 58B having a half-round shape at a top end and square shaped at a bottom end cross-section shown in Fig. 5C can be applied. The helical projecting ridge 58 can have a various cross-sectional shape within the object of the present invention. Furthermore, Instead of the helical projecting ridge 58, a helical groove 58D can be arranged helically on the outer surface 57a off the coil bobbin 57 so as to surround the outer surface 57a off the coil bobbin 57 as shown in Fig. 5D.

According to the embodiment, the coil bobbin 57 includes the helical even surface portions 59 fixing the plurality of single-turn wire portions 55 of the resonance coil 51 at intervals to each other, and the helical projecting ridge 58 between the helical even surface portions 59. The helical projecting ridge 58 is configured to have the surface distance between adjacent single-turn wire portions 55 of the resonance coil 51 fixed by the helical even surface portion 59 corresponding to voltage difference generated between each of adjacent single-turn wire portions 55. The surface discharge is prevented to secure the surface distance between each of the adjacent single-turn wire portions 55 of the resonance coil 51 by the helical projecting ridge 58. Thereby, and the resonance coil can be miniaturized not to elongate a surface distance between adjacent single-turn wire portions 55. Thus, surface discharge can be prevented in low cost without resin mold and not to increase a size of the resonance coil 51.

The helical projecting ridge 58 is configured to have the surface distance between the adjacent single-turn wire portions 55 of the resonance coil 51 at the center along the axial direction formed longer the surface distance between the adjacent single-turn wire portions at the both ends along the axial direction of the resonance coil 51. Thereby, surface discharge can be prevented in low cost without resin mold and not to increase a size of the resonance coil 51, which has a feature that the voltage difference generated between the adjacent single-turn wire portions at the center of the resonance coil 51 is larger than that at both ends of the resonance coil 51.

Second Embodiment Of Resonance Coil Unit: A second embodiment of a resonance coil unit according to the present invention will be described with reference to drawings Figs. 6-9.

A resonance coil unit 50B according to the second embodiment of the present invention shown in Figs. 6-9 includes the resonance coil 51 and a resonance-coil holding device 60. The resonance coil 51 is the same as that of the first embodiment, thereby, the same marking is putted and the description about it is omitted.

The resonance-coil holding device 60 includes a base unit 61 as the base member as shown in Fig. 6. The base unit 61 includes a board-shape base plate 62 to be mounted to the car body of the electric car or electric power charge apparatus, and a plurality of ribs 63 extending vertically from the base plate 62 at intervals along a circumferential direction of the single-turn wire portions 55 of the resonance coil 51 as a plurality of partial base member. In this embodiment, four ribs 63 are provided at even intervals. Any number of ribs, for example 2, 3, or 8, can be applied if force of fixing the resonance coil 51 can be secured.

The rib 63 includes a first rib member 64 and a second rib member 69, which are coupled with each other as shown in Figs. 7A-7D.

The first rib member 64 includes a first main body 65, and a plurality of flange portions 67 as a surface distance extending portion, and a plurality of fixing even surface portions 68.

The first main body 65 is made of insulation synthetic resin and formed into a band plate shape (that is bar shape), and one end along lengthwise direction thereof is mounted at a plate of the base plate 62 so as to extend vertically from the base plate 62.

The plurality of flange portions 67 is formed into wall-shape (projecting plate shape) over whole outer surface of the first main body 65, that is flange shape. The plurality of flange portions 67 is arranged at even intervals to each other. The plurality of flange portions 67 is formed into the same rectangular plate shape integrally with the first main body 65.

The plurality of flange portions 67 is designed to have its height from the outer surface of the first main body 65 and its thickness (that is size thereof) corresponding to the maximum value among the voltage differences generated between each of the adjacent single-turn wire portions which is led from the voltage distribution of the resonance coil 51 shown in Fig. 18. In other words, the plurality of flange portions 67 is configured to have a surface distance between adjacent single-turn wire portions 55 corresponding to a length, which prevent surface discharge between the adjacent single-turn wire portions 55 when the maximum voltage difference is generated between the adjacent single-turn wire portions, that is the length corresponds to the maximum voltage difference. For the surface distance, which surface discharge is not generated, a value determined under a predetermined safety standard (for example, IEC-International Electrotechnical Commission) is applied.

The flange portion 67 having such shape can secure suitably not only the surface distance passing one flat wall 65a of the first main body 65, but also the surface distances passing

side walls

65b, 65c facing to each other in a widthwise direction of the one flat wall 65a, and the surface distance passing the other flat wall 65d opposite to the one flat wall 65a.

The plurality of fixing even surface portions 68 is formed by that the plurality of flange portions 67 partitions the one flat wall 65a of the first main body 65. The plurality of fixing even surface portions 68 is arranged at intervals to each other along a lengthwise direction of the one flat wall 65a (up-and-down direction in Fig. 7A).

The plurality of fixing even surface portions 68 is provided with a groove portion 68a recessed curvedly with arc cross-section so as to contact a part of the outer surface of the resonance coil 51. Each interval between the groove portions 68a corresponds to the interval between single-turn wire portions of the resonance coil 51. To prevent the single-turn wire portions 55 from touching the flange portions 67 partitioning the fixing even surface portion 68 when the single-turn wire portions 55 are placed at the fixing even surface portions 68, the width of the fixing even surface portions 68 (that is distance between adjacent flange portions 67) is configured to be larger than a wire diameter of the resonance coil 51.

The second rib member 69 includes a second main body 70 made of insulation synthetic resin and formed into a band plate shape (that is bar shape) having the same length as the first main body 64 of the first rib member 64. The second main body 70 is provided at one flat wall 70a along a lengthwise direction thereof over whole length thereof with a plurality of square-pillar shape projecting portions 71 extending vertically oppositely to the plurality of fixing even surface portions 68. The plurality of projecting portion 71 has the same shape allowable to be inserted between the adjacent flange portions 67, and is formed integrally with the second main body 70. A groove 72 is formed between adjacent projecting portions 71 by the plurality of projecting portions 71.

When the first rib member 64 and the second rib member 69 are coupled, the plurality of projecting portions 71 is inserted between the plurality of flange portions 67, and the plurality of fixing even surface portions 68 and plurality of projecting portions 71 oppose to each other, so that the single-turn wire portions 55 of the resonance coil 51 are clamped (that is fixed) at intervals to each other between the groove portions 68a of the fixing even surface portions 68 and top ends 71a of the projecting portions 71. In other words, the plurality of fixing even surface portions 68 and plurality of projecting portions 71 structure coil fixing portions. The plurality of flange portions 67 and each couple of the plurality of fixing even surface portions 68 and the plurality of projecting portions 71 are arranged alternately. Thus, the plurality of flange portions 67 is arranged between each couple of the plurality of fixing even surface portions 68 and the plurality of projecting portions 71 (that is coil fixing portion).

The plurality of single-turn wire portions 55 of the resonance coil 51 is placed at the grooves 68a of the plurality of fixing even surface portions 68 of the first rib member 64, and thereafter, the first rib member 64 and the second rib member 69 are assembled so as to arrange the one flat wall 65a and the one flat wall 70a opposite to each other. These are joined by fixing members such not-shown screws or locking hooks, thereby the ribs 63 mentioned above are assembled.

At the time, the plurality of projecting portions 71 of the second rib member 69 is inserted between the plurality of flange portions 67 of the first rib member 64, and the single-turn wire portions 55 of the resonance coil 51 are clamped and fixed at intervals to each other between the plurality of fixing even surface portions 68 and the plurality of projecting portions 71. End edges of the plurality of flange portions 67 opposing to the one flat wall 70a are inserted between the groove 72 of the second rib member 69. Thus, the first rib member 64 and the second rib member 69 are arranged so as to be engaged with each other. To prevent the single-turn wire portions 55 from touching the flange portions 67 when the single-turn wire portions 55 are clamped between the plurality of the fixing even surface portions 68 and the plurality of projecting portions 71, the single-turn wire portions 55 of the resonance coil 51 are arranged. Therefore, the single-turn wire portions 55 of the resonance coil 51 is held partially at the outer surface thereof by the ribs 63, and the single-turn wire portions 55 are separated by the plurality of flange portions 67, so that the surface distance of each of the single-turn wire portions 55 can be secured.

The plurality of ribs 63 is arranged at even intervals along the circumference direction of the resonance coil 51 so as to hold the resonance coil 51 at partial circumference of the single-turn wire portions 55 of the resonance coil 51, so that the resonance coil 51 is fixed at the base plate 62.

According to this embodiment, the plurality of ribs 63 arranged at the base unit 61 includes the plurality of fixing even surface portions 68 and the plurality of projecting portions 71, between which the plurality of single-turn wire portions 55 of the resonance coil 51 is fixed at intervals to each other; and the plurality of flange portions 67, which is arranged respectively between each of the plurality of fixing even surface portions 68 and each of the plurality of projecting portions 71. The plurality of flange portions 67 is configured to have the surface distance between the adjacent single-turn wire portions 55 of the resonance coil 51 fixed between the plurality of fixing even surface portions 68 and the plurality of projecting portions 71 corresponding to the maximum voltage difference among voltage differences respectively generated between each adjacent single-turn wire portions 55. Thereby, securing the surface distance between adjacent single-turn wire portions 55 of the resonance coil 51 by the plurality of flange portions 67 can prevent the surface discharge, and each of the plurality of the flange portions 67 can be formed easily so as to have the same shape under the one reference (that is the maximum voltage difference). Therefore, the surface discharge can be prevented without increasing the size of the resonance coil 51 and in low cost without resin molding.

The base unit 61 includes the plurality of ribs 63 arranged at intervals to each other along the circumference direction of the resonance coil 51, and each of the plurality of ribs 63 includes the plurality of fixing even surface portion 68, the plurality of projecting portions 71, and the plurality of flange portions 67. Therefore, the plurality of single-turn wire portions 55 of the resonance coil 51 can be held partially at few points along the circumference thereof. Thereby, not by holding whole resonance coil 51, amount of material for usage can be decreased, so that the base unit 61 can be lightened reduce the cost.

The plurality of ribs 63 is not limited to be configured to have above structure. For example, the ribs 63 can be configured by that the first rib member 64 is formed into a same shape as the second rib member 69; and the projection of the first rib member 64 and the projecting portions 71 of the second rib member 69 are arranged to be opposite to each other; and each of the single-turn wire portions of the resonance coil 51 is clamped by the projection and the projecting portion, and the first rib member 64 and the second rib member 69 are joined by the fixing member. In this case, the projection of the first rib member 64 and the projecting portion of the second rib member 69 correspond to coil fixing portions in claims and each groove correspond to surface distance extending portions in claims.

As a modification of this embodiment, the plurality of flange portions 67 is formed over whole outer surface of the first main body 65 into a wall shape (projection), that is a flange. The plurality of flange portions 67 is arranged at even intervals to each other. The plurality of flange portions 67 is formed into a rectangular plate shape integrally with the first main body 65. In the resonance coil 51, the voltage difference between adjacent single-turn wire portions 55 increases toward the center thereof along the axial direction (that is direction along the length L) and decreases toward the both ends along the axial direction, clearly as shown in Fig. 18. Correspondingly, the plurality of flange portions 67 is configured to have the surface distance between the adjacent single-turn wire portions 55 in accordance with the voltage difference generated between the adjacent single-turn wire portions 55.

Physically, as shown in Figs. 8A-8D, the plurality of flange portions 67 is arranged over whole outer surface of the first main body 65 with a wall shape (projection), that is a flange, and at even intervals to each other. The plurality of flange portions 67 is formed to have the rectangular plate shape decreasing (making its area viewed from side thereof smaller) gradually from the center along the whole length (that is at the center along the axial direction of the resonance coil 51) toward the both ends along the lengthwise direction (that is the both ends of the resonance coil 51 along the axial direction. In other words, the plurality of flange portions 67 is configured to have the surface distance between adjacent single-turn wire portions 55 at the center along the axial direction (that is the center in claims) longer than the surface distance between adjacent single-turn wire portions 55 at the both ends along the axial direction, and the plurality of flange portions 67 is configured to have the surface distance between adjacent single-turn wire portions 55 of the resonance coil 51 increasing gradually from the both ends along the axial direction toward the center along the axial direction.

The height from the outer surface of the first main body 65 and the thickness (that is shape) of the plurality of flange portions 67 is determined in accordance with the voltage difference between adjacent single-turn wire portions 55 led from the voltage distribution of the resonance coil 51 shown in Fig. 18. In other words, the plurality of flange portions 67 is configured to have a surface distance between adjacent single-turn wire portions 55 corresponding to the length, which prevents surface discharge between each of the adjacent single-turn wire portions 55 when the voltage difference is generated between the each of the adjacent single-turn wire portions 55, that is corresponding to the length according to the voltage difference. For the surface distance, which surface discharge is not generated, a value determined under a predetermined safety standard (for example, IEC-International Electrotechnical Commission) is applied. The flange portion 67 having such shape can secure suitably not only the surface distance passing one flat wall 65a of the first main body 65, but also the surface distances passing

side walls

According to the embodiment mentioned above, the plurality of ribs 63 arranged at the base unit 61 includes the plurality of fixing even surface portions 68 and the plurality of projecting portions 71, between which the plurality of single-turn wire portions 55 of the resonance coil 51 is fixed at intervals to each other; and the plurality of flange portions 67, which is arranged respectively between each of the plurality of fixing even surface portions 68 and each of the plurality of projecting portions 71. The plurality of flange portions 67 is configured to have the surface distance between the adjacent single-turn wire portions 55 of the resonance coil 51 fixed between the plurality of fixing even surface portions 68 and the plurality of projecting portions 71 corresponding to each voltage difference respectively generated between each adjacent single-turn wire portions 55. Thereby, securing the surface distance between adjacent single-turn wire portions 55 of the resonance coil 51 by the plurality of flange portions 67 can prevent the surface discharge, and the size of the resonance coil unit can be decreased not to extend the surface distance between adjacent single-turn wire portions 55 over than required length. Therefore, the surface discharge can be prevented without increasing the size of the resonance coil 51 and in low cost without resin molding.

The plurality of flange portions 67 is configured to have the surface distance between adjacent single-turn wire portions 55 at the center along the axial direction of the resonance coil 51 longer than the surface distances between the adjacent single-turn wire portions 55 at the both ends of the resonance coil 51. Thereby, in the resonance coil 51, which has a feature that the voltage difference generated between the adjacent single-turn wire portions at the center along the axial direction of the resonance coil 51 is larger than that at both ends along the axial direction, surface discharge can be prevented not to increase the size of the resonance coil 51 and in low cost.

The plurality of ribs 63 is not limited to be configured to have above structure. For example, the rib 63 can be configured to maintain the height of each projecting portion 71 of the second rib member 69, and increase depth of each groove 72 gradually from the both ends along the lengthwise direction of the second rib member 69 toward the center along the lengthwise direction, and also to form the first rib member 64 as same as the second rib member 69, and face the projections of the first rib member 64 and the projecting portions 71 of the second rib member 69 to each other so as to clamp the each single-turn wire portion 55 between the projections and the projecting portions, and join the first rib member 64 and the second rib member 69 by a fixing member. The projections of the first rib member 64 and the projecting portions of the second rib member 69 correspond to the coil fixing portions in claims and each groove correspond to the surface distance extending portions in claims.

In this embodiment, the resonance coil unit includes the resonance coil 51, which has the plurality of single-turn wire portions formed into cylinder shape (helical shape). The present invention is not limited in this, and for example, the resonance coil unit may include a resonance coil 52, which has the plurality of single-turn wire portions formed into flat plate shape (spiral shape) as shown in Fig. 9. In the case, the plurality of ribs 63 mentioned above is arranged in parallel to a plane of the base plate 62 so as to hold the flat-plate shape resonance coil 52. In this structure, the plurality of fixing even surface portions 68, the plurality of projecting portions 71 and the plurality of flange portions 67 of the rib 63 may be configured to curve along an arc of the single-turn wire portions 55 of the resonance coil 52. Instead, the resonance coil unit can have a resonance coil having a plurality of single-turn wire portions formed into square pipe shape or square flat shape. The resonance coil can have a various shape within the object of the present invention. The word "spiral" means "flat-plate shape" corresponding to "helical" meaning "cylindrical".

Third Embodiment Of Resonance Coil Unit: The third embodiment of a resonance coil unit according to the present invention will be described with reference to drawings Figs. 10-12.

As the resonance coil unit, one of various resonance coils is configured to mold over whole resonance coil with insulation material. In the case, after assembling the resonance coil unit, the resonance coil cannot be reassembled, so that a length of the resonance coil cannot be changed to adjust for resonance frequency. For solving the problem, a structure by the insulation material enveloping the resonance coil is designed to be separable for removing the resonance coil easily after assembling. However, even if each of the insulation material is fitted to each other when the insulation material is separable, there may be trouble that surface discharge is generated through a separate surface of the insulation material. This embodiment is suitable solution for the problem.

The resonance coil unit 50D according to the third embodiment of the present invention shown in Figs. 10-12 includes the resonance coil 52 and a resonance-coil holding device 76.

The resonance coil 52 is configured to have a plurality of single-turn wire portions by winding cupper wire of 5mm diameter at plural turns (n turns) in flat plate shape (spiral shape) as an air-core coil with an inner diameter D1 of 450mm and an outer diameter D2 of 600mm. The resonance coil 52 includes a plurality of circle shape single-turn wire portions 55[1]-55[n]. Between one single-turn wire portion 55[k] and the other single-turn wire portion 55[k+1] (k: from 1 to n-1) adjacent to the one single-turn wire portion (hereafter, simply call between adjacent single-turn wire portions 55), a gap between conductive wires required to prevent dielectric breakdown between single-turn wire portions. The gap between conductive wires is formed to have the same length between each adjacent single-turn wire portions. In this embodiment, the resonance coil 52 is structured by a bare wire. A covered wire, which an outer surface of the bare wire is covered with an insulation cover made of vinyl chloride resin or polyamide resin, can be applied for the wire.

Voltage distribution of the resonance coil 52 in resonant condition is similar as the voltage distribution of the resonance coil 51 mentioned above as shown in Fig. 18. Clearly shown in Fig. 18, the voltage difference per unit distance (that is incline in the graph) about the resonance coil 52 is larger at the center (that is the origin of graph, a middle point between an inner edge and an outer edge of the resonance coil 52 ) and decreased toward the both ends along a radius direction (that is and of the graph; and the inner edge or the outer edge of the resonance coil 52). Thus, voltage difference between single-turn wire portions 55 of the resonance coil 52 wound spirally into flat plate shape is changed according to positions thereof, and physically, the voltage difference between single-turn wire portions 55 is increased toward the center in radius direction and decreased toward the both ends along the radius direction.

The resonance-coil holding device 76 includes a base member 77 structured by a first plate member 81 and a second plate member 91, which are joined to each other.

The first plate member 81 is formed by insulation resin into square shape in plan view so as to make one side of the square shape larger than the outer diameter of the resonance coil 52. In other words, the first plate member 81 is configured to include the resonance coil 52 within a joining surface 81a when the resonance coil 52 is mounted on the joining surface 81a of the first plate member 81. The joining surface 81a of the first plate member 81 is provided with a first extending portion 82 and a first fixing portion 85 as shown in Fig. 11A.

The first extending portion 82 is a projecting ridge arranged at the joining surface 81a so as to form spiral shape from a central portion of the joining surface 81a toward an outer edge thereof. A plurality of single-turn spiral portions 82a of the first extending portion 82 is arranged at even interval. The first extending portion 82 is formed over a whole length thereof so as to have the same cross-section of wedge shape as shown in Fig. 12A. Instead of such first extending portion 82, the first extending portion 82A, which have a combination shape of a projecting ridge with rectangular cross-section and a groove line with rectangular cross-section as shown in Fig. 12B, can be provided. The first extending portion 82 can have a various shape within the object of the present invention.

The first fixing portion 85 is a portion, which is formed by partitioning the joining surface 81a spirally by the first extending portion 82. The first fixing portion 85 and the first extending portion 82 are arranged spirally along each other at the joining surface 81a. In other words, single-turn spiral portions 82a of the first extending portion 82 and spiral portions 85a of the first fixing portion 85 are arranged alternately in a direction from the central portion of the joining surface 81a toward the outer edge thereof (that is radius direction). Thus, the first extending portion 82 is arranged between the spiral portions 85a of the first fixing portion 85.

The first fixing portion 85 is provided at a central portion in a widthwise direction thereof over whole length thereof with a spiral groove 85b by recessing partially into an arc cross-section so as to fit a part of an outer surface of the resonance coil 52. An interval between adjacent spiral portions of the spiral groove 85b corresponds to an interval between adjacent single-turn wire portions 55 of the resonance coil 52. The resonance coil 52 is arranged along the spiral groove 85b at the first fixing portion 85.

The second plate member 91 is formed by insulation resin into square shape in plan view so as to be the same as the first plate member 81. The first plate member 81 and the second plate member can be formed into a various shape other than the square shape in plan view. The second plate member 91 is provided at a joining surface 91a with a second extending portion 92 and a second fixing portion 95 as shown in Fig. 12B.

The second extending portion 92 is a groove line arranged at the joining surface 91a so as to form spiral shape from a central portion of the joining surface 91a toward an outer edge thereof corresponding to the first extending portion 82. A plurality of single-turn spiral portions 92a of the second extending portion 92 is arranged at even intervals. The second extending portion 92 is formed over a whole length thereof so as to have the same cross-section of wedge shape, which engages with the first extending portion 82, as shown in Fig. 12A. Instead of such second extending portion 92, the second extending portion 92A, which have a combination shape of a projecting ridge with rectangular cross-section and a groove line with rectangular cross-section formed to engage with the first extending portion 82A as shown in Fig. 12B, can be provided. The second extending portion 92 can have a various shape within the object of the present invention.

The second fixing portion 95 is a portion, which is formed by partitioning the joining surface 91a spirally by the second extending portion 92. The second fixing portion 95 and the second extending portion 92 are arranged spirally along each other at the joining surface 91a. In other words, single-turn spiral portions 92a of the second extending portion 92 and single-turn spiral portions 95a of the second fixing portion 95 are arranged alternately in a direction from the central portion of the joining surface 91a toward the outer edge thereof (that is radius direction). Thus, the second extending portion 92 is arranged between the adjacent single-turn spiral portions 95a of the second fixing portion 95.

The second fixing portion 95 is provided at a central portion in a widthwise direction thereof over whole length thereof with single-turn spiral portions (groove) 95b by recessing partially into an arc cross-section so as to fit a part of an outer surface of the resonance coil 52. An interval between adjacent single-turn spiral portions 95b corresponds to the interval between adjacent single-turn wire portions 55 of the resonance coil 52. The resonance coil 52 is arranged along the single-turn spiral portions 95b at the second fixing portion 95.

When the joining surface 81a of the first plate member 81 and the joining surface 91a of the second plate member 91 are joined to each other, the first fixing portion 85 and the second fixing portion 95 face to each other, and clamp (that is fix) the resonance coil 52 arranged between the single-turn spiral groove 85b of the first fixing portion 85 and the single-turn spiral portions 95b of the second fixing portion 95 so as to have a space between the first fixing portion 85 and the second fixing portion 95. In other words, the first fixing portion 85 and the second fixing portion 95 structure a coil fixing portion in claims. The first extending portion 82 (that is spiral projecting ridge) is inserted into the second extending portion 92 (that is spiral groove line) so as to engage with each other. Thereby, each of the single-turn wire portions 55 of the resonance coil 52 is partitioned, so that the surface distance can be secured. In other words, the first extending portions 82 and the second extending portions 95 structure surface distance extending portions in claims. In Figs. 11, 12, a gap between the joining surface 81a of the first plate member 81 and the joining surface 91a of the second plate member 91 is provided for explanation. Actually, the joining surface 81a and the joining surface 91a are contacted tightly. Or, as shown in Figs. 12A, 12B, a small gap between the joining surface 81a and the joining surface 91a can be provided.

A height from the joining surface 81a and a vertex angle (that is shape) of the first extending portion 82 are determined according to a maximum voltage difference among the voltage differences between each of adjacent single-turn wire portions 55, which value is calculated from the voltage distribution of the resonance coil 52 shown in Fig. 18. Similarly, a depth from the joining surface 91a and a vertex angle (that is shape) of the second extending portion 92 are determined according to a maximum voltage difference among the voltage differences between each of adjacent single-turn wire portions 55, which value is calculated from the voltage distribution of the resonance coil 52 shown in Fig. 18. In other words, the first extending portion 82 and the second extending portion 92 are configured so as to have a surface distance between adjacent single-turn wire portions 55 corresponding to the length, which prevents surface discharge between each of the adjacent single-turn wire portions 55 when the maximum voltage difference is generated between the each of the adjacent single-turn wire portions 55, that is the length corresponding to the maximum voltage difference. For the surface distance, which surface discharge is not generated, a value determined under a predetermined safety standard (for example, IEC-International Electrotechnical Commission) is applied.

The resonance coil 52 is placed at the spiral groove 85b of the first fixing portion 85 of the first plate member 81, and the first plate member 81 and the second plate member 91 are coupled so as to join the joining surface 81a and the joining surface 91a to each other, and which is joined together by fixing member such a screw S. Thus, the resonance-coil holding device 76 is assembled.

In such condition, the resonance coil 52 is arranged between the spiral groove 85b of the first plate member 81 and the spiral groove 95b of the second plate member 91, and the single-turn wire portions 55 are clamped at intervals to each other. Simultaneously, the first extending portion 82 of the first plate member 81 is inserted into the second extending portion 92 of the second plate member 91 so as to engage with each other. Thus, the single-turn wire portions 55 of the resonance coil 52 are held at intervals to each other by the first plate member 81 and the second plate member 91 so as to be partitioned by the first extending portion 82 and the second extending portion 92, so that the surface distance between each of the adjacent single-turn wire portions 55 can be secured.

As mentioned above, according to this embodiment, the first plate member 81 arranged at the base member 77 includes the first fixing portion 85 and the first extending portions 82 arranged between the first fixing portion 85, and the second plate member 91 includes the second fixing portion 95 fixing the plurality of single-turn wire portions 55 of the resonance coil 52 at intervals between the first fixing portion 85 and itself, and the second extending portions 92 arranged between the second fixing portion 95. The first extending portion 82 and the second extending portion 92 are configured to have the surface distance between adjacent single-turn wire portions 55 corresponding to the length, which prevents surface discharge between each of the adjacent single-turn wire portions 55 when the maximum voltage difference is generated between the each of the adjacent single-turn wire portions 55. Surface discharge can be prevented by securing the surface distance between each of the adjacent single-turn wire portions 55 of the resonance coil 52 by the first extending portions 82 and the second extending portions 92. Furthermore, the first extending portions 82 and the second extending portions 92 can be formed to have the same shape over the whole length thereof under one reference (that is the maximum voltage difference). Therefore, surface discharge can be prevented in low cost by eliminating resin mold and without increase of the size of the resonance coil 52.

The base member 77 also includes the first plate member 81 and the second plate member 91, which are joined to each other. The first plate member 81 includes the first fixing portion 85 arranged spirally at the joining surface 81a. The second plate member 91 includes the second fixing portion 95 arranged spirally corresponding to the first fixing portion 85 at the joining surface 91a. The first fixing portion 85 an d the second fixing portion 95 clamp the spiral resonance coil 52 therebetween. The first plate member 81 is provide at the joining surface 81a with the first extending portions 82 arranged spirally along the first fixing portions 85. The second plate member 91 is provide at the joining surface 91a with the second extending portions 92 arranged spirally along the second fixing portions 95 corresponding to the first extending portion 82 so as to engage with the first extending portion 82. Thereby, the single-turn wire portions 55 of the resonance coil 52, which are spirally wound in plural turns, are clamped and fixed between the first fixing portions 85 and the second fixing portions 95. The first extending portions 82 and the second extending portions 92, which engage with each other, partition the resonance coil 52. Thus, the resonance coil 52 is clamped between the first extending portions 81 and the second extending portions 91, which are preformed, so that the resonance coil 52 can be sealed simply in low cost so as to secure the surface distance. Therefore, electric shock by touching the resonance coil can be prevented.

As a modification of this embodiment, the extending portions 82 is a projecting ridge arranged spirally at the joining surface 81a from the central portion toward the outer edge of the joining surface 81a. The plurality of single-turn spiral portions 82a of the first extending portion 82 is arranged at even intervals. The first extending portion 82 is configured to have the wedge shape cross-section over the whole length thereof, as shown in Fig. 14A. The voltage difference between the adjacent single-turn wire portions 55 of the resonance coil 52 is increased toward the center along the radius direction of the resonance coil 52 and decreased toward the both ends along the radius direction as shown in Fig. 18. Correspondingly, the first extending portion 82 is configured to have the surface distance between each of the adjacent single-turn wire portions 55 according to the voltage difference generated between each of the adjacent single-turn wire portions 55.

Physically, the first extending portion 82 is the projecting ridge arranged spirally from the central portion of the joining surface 81a toward the outer edge thereof at the joining surface 81a as shown in Fig. 13. The plurality of single-turn spiral portions 82a of the first extending portion 82 is arranged at even intervals. The first extending portion 82 is formed to have wedge shape cross-section over the whole length thereof. The first extending portion 82 is configured to have a cross-section decreased (height becoming lower) gradually from the central portion along radius direction of the first extending portion 82 (that is the central portion along radius direction of the resonance coil 52) toward the both ends along the radius direction (that is the central portion along radius direction of the resonance coil 52). In other words, the surface distance between each adjacent single-turn wire at the central portion (that is center in claims) is formed longer than the surface distance between adjacent single-turn wire portions at the both ends along radius direction (both ends in claims). In other words, the first extending portion 82 is configured to have the surface distance between adjacent single-turn wire portions 55 of the resonance coil 52 increasing from the both ends along radius direction toward the central portion along radius direction.

A height from the joining surface 81a and a vertex angle (that is shape) of the first extending portion 82 is determined according to the voltage difference between each of adjacent single-turn wire portions 55, which is led from the voltage distribution of the resonance coil 52 shown in Fig. 18. In other words, the first extending portion 82 is configured to have the surface distance between adjacent single-turn wire portions 55 corresponding to the length, which prevents surface discharge between each of the adjacent single-turn wire portions 55 when the above voltage difference is generated between the each of the adjacent single-turn wire portions 55. For the surface distance, which surface discharge is not generated, a value determined under a predetermined safety standard (for example, IEC-International Electrotechnical Commission) is applied.

Instead of this first extending portion 82, a first extending portion 82A, which have a combination shape of a projecting ridge with rectangular cross-section and a groove line with rectangular cross-section as shown in Fig. 14B, can be provided. The first extending portion 82 can have a various shape within the object of the present invention.

The second plate member 91 is formed by insulation synthetic resin into a square plate shape in plan view as same as the first plate member 81. The joining surface 91a of the second plate member 91 is provided with the second extending portion 92 and the second fixing portion 95 as shown in Fig. 11B.

The second extending portion 92 is a groove line arranged at the joining surface 91a so as to form spiral shape from the central portion of the joining surface 91a toward an outer edge thereof corresponding to the first extending portion 82. The plurality of single turn spiral portions 92a of the second extending portion 92 is arranged at even intervals. The second extending portion 92 is configured to have the wedge shape cross-section over the whole length thereof, which engages with the first extending portion 82 to each other, as shown in Fig. 14A. The voltage difference between the adjacent single-turn wire portions 55 of the resonance coil 52 is increased toward the center along the radius direction of the resonance coil 52 and decreased toward the both ends along the radius direction, clearly as shown in Fig. 18. Correspondingly, the second extending portion 92 is configured to have the surface distance between each of the adjacent single-turn wire portions 55 according to the voltage difference generated between each of the adjacent single-turn wire portions 55.

Physically, the second extending portion 92 is the groove line arranged spirally from the central portion of the joining surface 91a toward the outer edge thereof corresponding to the first extending portion 82 at the joining surface 91a. The plurality of single-turn spiral portion 92a of the second extending portion 92 is arranged at even intervals. The second extending portion 92 is formed to have wedge shape cross-section over the whole length thereof. The second extending portion 92 is configured to have a cross-section decreased (height becoming lower) gradually from the central portion along radius direction of the second extending portion 92 (that is the central portion along radius direction of the resonance coil 52) toward the both ends along the radius direction (that is the central portion along radius direction of the resonance coil 52). In other words, the surface distance between each adjacent single-turn wire at the central portion (that is center in claims) is formed longer than the surface distance between adjacent single-turn wire portions at the both ends along radius direction (both ends in claims). In other words, the first extending portion 82 is configured to have the surface distance between adjacent single-turn wire portions 55 of the resonance coil 52 increasing from the both ends along radius direction toward the central portion along radius direction.

A height from the joining surface 91a and a vertex angle (that is shape) of the second extending portion 92 is determined according to the voltage difference between each of adjacent single-turn wire portions 55, which is led from the voltage distribution of the resonance coil 52 shown in Fig. 18. In other words, the second extending portion 92 is configured to have the surface distance between adjacent single-turn wire portions 55 corresponding to the length, which prevents surface discharge between each of the adjacent single-turn wire portions 55 when the above voltage difference is generated between the each of the adjacent single-turn wire portions 55. For the surface distance, which surface discharge is not generated, a value determined under a predetermined safety standard (for example, IEC-International Electrotechnical Commission) is applied.

Instead of such second extending portion 92, the second extending portion 92A, which have a combination shape of a projecting ridge with rectangular cross-section and a groove line with rectangular cross-section as shown in Fig. 14B, can be provided. The second extending portion 92 can have a various shape within the object of the present invention.

As mentioned above, according to this embodiment, the first plate member 81 arranged at the base member 77 includes the first fixing portion 85 and the first extending portions 82 arranged between the first fixing portion 85, and the second plate member 91 includes the second fixing portion 95 fixing the plurality of single-turn wire portions 55 of the resonance coil 52 at intervals between the first fixing portion 85 and itself, and the second extending portions 92 arranged between the second fixing portion 95. The first extending portion 82 and the second extending portion 92 are configured to have the surface distance between adjacent single-turn wire portions 55 corresponding to the length, which prevents surface discharge between each of the adjacent single-turn wire portions 55 when the voltage difference is generated between the each of the adjacent single-turn wire portions 55. Surface discharge can be prevented by securing the surface distance between each of the adjacent single-turn wire portions 55 of the resonance coil 52 by the first extending portions 82 and the second extending portions 92. Furthermore, the size of the resonance coil 52 can be decreased not to extend the surface distance between adjacent single-turn wire portions 55 over than required length. Therefore, surface discharge can be prevented in low cost by eliminating resin mold and without increase of the size of the resonance coil 52.

The first extending portion 82 and the second extending portion 92 are configured to have the surface distance between the adjacent single-turn wire portions 55 at the center along the radial direction of the resonance coil 52 formed longer the surface distance between the adjacent single-turn wire portions 55 at the both ends along the axial direction of the resonance coil 52. Thereby, surface discharge can be prevented in low cost and not to increase a size of the resonance coil 52, which has a feature that the voltage difference generated between the adjacent single-turn wire portions 55 at the center along the radius direction of the resonance coil 52 is larger than that at both ends along the radius direction of the resonance coil 52.

In this embodiment, the resonance coil 52 is formed into flat circular shape (round spiral shape) having a plurality of wound wire portions. The present invention is not limited in this, and the resonance coil can be formed into square flat shape (square spiral shape) having a plurality of wound wire portions. The resonance coil can have a various shape within the object of the present invention.

One embodiment of non-contact type electric power transmission apparatus: A wireless electric power transmission apparatus according to one embodiment of non-contact type electric power transmission apparatus having the above resonance coil of the present invention will be described with reference to Figs. 15-17.

Fig. 15 is an illustration showing a structure of a wireless electric power transmission apparatus as an embodiment according to the present invention. The wireless electric power transmission apparatus 10 according to the embodiment includes a power receiving unit 12 mounted at an electric car 5 and a power supply unit 11 supplying AC electric power toward the power receiving unit 12. AC electric power outputted from the power supply unit 11 is transmitted toward the power receiving unit 12 by a non-contact (wireless) method. The power supply unit 11 includes a transmission coil 24 for transmitting electric power. When AC electric power is supplied to the transmission coil 24, the AC electric power is transmitted to a transmission coil 31 for receiving electric power arranged at the power receiving unit 12.

The power receiving unit 12 mounted at the electric car 5 includes the transmission coil 31 for receiving electric power, which is arranged in the vicinity of the transmission coil 24 for transmitting electric power when the electric car 5 is placed at a predetermined position of the power supply unit 11 for electric power charging, and a rectifier 33. The power receiving unit 12 further includes a battery 35, in which DC power is charged, a DC/DC converter 42 dropping voltage value of the battery 35 and supplying it to a subbattery 41, an inverter 43 inverting output from the battery 35 to AC power, and a motor 44 driven by the AC power outputted from the inverter 43.

Fig. 16 is a block diagram of the wireless electric power transmission apparatus 10 of the embodiment according to the present invention. The power supply unit 11 and the power receiving unit 12 to be mounted at the electric car are shown.

The power supply unit 11 includes a carrier oscillator 21 outputting carrier signal for transmitting electric power, a power amplifier 23 amplifying the carrier signal (that is AC power) outputted from the carrier oscillator 21, and the transmission coil 24 outputting the AC power amplified by the power amplifier 23. The transmission coil 24 includes a power supply coil L1 (primary coil) and a transmit resonance coil X1, as described later. The above-mentioned resonance coil unit 50 (or the

resonance coil unit

50B, 50D) is applied for the transmit resonance coil X1.

The carrier oscillator 21 outputs AC power of frequency 0.1 MHz-100 MHz as the AC signal for power transmission.

The power amplifier 23 amplifies AC power outputted from the carrier oscillator 21, and outputs the amplified AC power to the transmission coil 24. The transmission coil 24 interacts with the transmission coil 31 arranged at the power receiving unit 12 so as to transmit the AC power to the transmission coil 31 by wireless resonance-type electric power transmission method. The resonance-type electric power transmission method will be described later.

The power receiving unit 12 further includes the transmission coil 31 for receiving AC power transmitted from the transmission coil 24 for transmitting electric power, the rectifier 33 rectifying AC power received by the transmission coil 31 so as to generate DC voltage. The power receiving unit 12 includes the battery 35 supplying electric power to the motor 44 (see Fig. 15) for driving car, and the battery 35 is charged by DC power outputted from the rectifier 33.

The transmission coil 31 is structured by a power receiving coil L2 (primary coil) and a receive resonance coil X2, as described later. The above-mentioned resonance coil unit 50 (or

resonance coil unit

50B, 50D) is applied for the receive resonance coil X2.

The resonance-type electric power transmission method will be described here. Fig. 17 is an illustration showing a basic theory of a resonance-type electric power transmission method. As shown in Fig. 17, the power supply unit 11 includes the power supply coil L1 and the transmit resonance coil X1 (that is resonance coil unit 50). The power supply coil L1 and the transmit resonance coil X2 provide the transmission coil 24 shown in Figs. 10 and 11. The power receiving unit 12 includes the power receiving coil L2 and the receive resonance coil X2 (that is resonance coil unit 50) arranged coaxially with the power receiving coil L2 in the vicinity of the power receiving coil L2. The power receiving coil L2 and the receive resonance coil X2 structure the transmission coil 31 shown in Figs. 15 and 16.

When primary current is flowed in the power supply coil L1, inductive current flows in the transmit resonance coil X1 by electromagnetic induction. Furthermore, the transmit resonance coil X1 resonates at a resonance frequency

by effect of inductance Ls and stray capacitance Cs of the transmit resonance coil X1. Thereby, the receive resonance coil X2 arranged in the vicinity of the transmit resonance coil X1 resonates at the resonance frequency

, and a secondary current flows in the receive resonance coil X2. Furthermore, secondary current flows in the power receiving coil L2 arranged in the vicinity of the receive resonance coil X2 by electromagnetic induction

Under the above actions, electric power can be transmitted by wireless from the power supply unit 11 to the power receiving unit 12.

Actions of the wireless electric power transmission apparatus according to the present invention shown in Figs. 15 and 16 will be described. When the electric car 5 is placed at the predetermined position of the power supply unit 11, and the transmission coil 24 arranged at the power supply unit 11 is arranged so as to correspond to the transmission coil 31 arranged at the power receiving unit 12 of the electric car 5 as shown in Fig. 15, the battery 35 can be charged.

When charging is started, AC power of frequency from 0.1 MHz to 100 MHz is outputted from the carrier oscillator 21 shown in Fig. 16.

The AC power outputted from the carrier oscillator 21 is amplified by the power amplifier 23. The amplified AC power is transmitted through the transmission coil 24 and the transmission coil 31 to the power receiving unit 12 under the above-mentioned resonance-type electric power transmission method.

The AC power transmitted to the power receiving unit 12 is outputted from the transmission coil 31 to the rectifier 33.

The rectifier 33 rectifies the AC power to DC power having a predetermined voltage, and supplies the DC power to the battery 35 so as to charge the battery 35. Thus, the battery 35 can be charged.

According to the present invention, the above-mentioned resonance coil unit 50 is applied for the transmit resonance coil X1 and the receive resonance coil X2. Thereby, the resonance coil holding device 56 of the resonance coil unit 50 includes the helical projecting ridge 58 as the surface distance extending portions, so that surface discharge can be prevented by securing the surface distance between each of adjacent single-turn wire portions of the resonance coil 51. Therefore, the surface discharge can be prevented without increasing the size of the resonance coil 51 in low cost.

According to the embodiment, the above-mentioned resonance coil unit 50 is applied for both of the transmit resonance coil X1 and the receive resonance coil X2. The present invention is not limited in this, the resonance coil unit 50 can be applied for at least one of the transmit resonance coil X1 and the receive resonance coil X2.

The present inventions are described based in the embodiments as mentioned above, but the present invention is not limited in above embodiments. Various change and modifications can be made with the scope of the present invention.

5 Electric car
10 Wireless (Non-contact) electric power transmission apparatus
50, 50B, 50D Resonance coil unit
51, 52 Resonance coil
55 Single-turn wire portion
56 Resonance coil holding device
57 Coil bobbin (base member)
58 Helical projecting ridge (surface distance extending portion)
59 Helical even surface portion (coil fixing portion)
60 Resonance-coil holding device
61 Base unit (base member)
63 Rib (partial base member)
67 Flange portion (surface distance extending portion)
68 Fixing even surface portion (coil fixing portion)
71 Projecting portion (coil fixing portion)
72 Groove
76 Resonance-coil holding device
77 Base member
81 First plate member
81a Joining surface
82 First extending portion (surface distance extending portion)
85 First fixing portion (coil fixing portion)
91 Second plate member
91a Joining surface
92 Second extending portion (surface distance extending portion)
95 Second fixing portion (coil fixing portion)
X1 Transmit resonance coil (resonance coil unit)
X2 Receive resonance coil (resonance coil unit)

Claims

A resonance-coil holding device for holding a resonance coil, which transmits electric power to a mating coil or receives electric power transmitted from the mating coil by resonance phenomena, and is formed to have a plurality of single-turn wire portions, the resonance-coil holding device comprising:
a base member;
coil fixing portions arranged at the base member so as to fix the plurality of single-turn wire portions of the resonance coil at intervals to each other; and
surface distance extending portions arranged between the coil fixing portions arranged at the base member, wherein the surface distance extending portions are configured to have a shape selected among a projection shape, a recess shape, and combination shape of the projection shape and the recess shape,
wherein the surface distance extending portion is configured to have a surface distance between respective adjacent single-turn wire portions corresponding to a voltage difference generated between the respective adjacent single-turn wire portions.
The resonance-coil holding device according to claim 1, wherein the surface distance extending portions are configured to have the surface distance between the adjacent single-turn wire portions corresponding to a maximum voltage difference among voltage differences respectively generated between each adjacent single-turn wire portions.
The resonance-coil holding device according to claim 1, wherein the surface distance extending portions are configured to have the surface distance at the center of the resonance coil longer than the surface distances at both ends of the resonance coil.
The resonance-coil holding device according to claim 1, 2 or 3,
wherein the resonance coil is formed into a cylindrical shape to have the plurality of single-turn wire portions, and the base member is formed into one of a cylindrical shape and a columnar shape, and the coil fixing portions are arranged helically at one of an outer surface of the base member and an inner surface of the base member,
wherein the surface distance extending portions between the adjacent single-turn wire portions are arranged helically along the coil fixing portions at one of the outer surface of the base member and the inner surface of the base member.
The resonance-coil holding device according to claim 1, 2 or 3, wherein the base member includes a plurality of base member pieces arranged at intervals to each other along a circumferential direction of the resonance coil, and the plurality of base member pieces includes respectively the coil fixing portions and the surface extending portions between the adjacent single-turn wire portions.
The resonance-coil holding device according to claim 1, 2 or 3, wherein the resonance coil is formed spirally to have a plurality of turns; wherein the base member includes a first plate member and a second plate member, which are joined to each other; and the coil fixing portions include a first fixing portion arranged spirally at a joining surface of the first plate member and a second fixing portion arranged spirally corresponding to the first fixing portion at a joining surface of the second plate member so as to clamp each of the single-turn wire portions between the first fixing portion and the second fixing portion; wherein the surface distance extending portions between the adjacent single-turn wire portions include a first extending portion arranged spirally along the first fixing portion at the joining surface of the first plate member, and a second extending portion arranged spirally along the second fixing portion at the joining surface of the second plate member so as to be corresponding to the first extending portion and be engaged with the first extending portion with clearance.
A resonance coil unit, comprising:
a resonance coil configured to have a plurality of single-turn wire portions so as to transmit electric power to a mating coil and receive electric power transmitted from the mating coil by resonance phenomena; and
a resonance-coil holding device holding the resonance coil,
wherein the resonance-coil holding device corresponds to the resonance-coil holding device according to one of claims 1-6.
A non-contact type electric power transmission apparatus, comprising:
a transmission resonance coil unit transmitting electric power by resonance phenomena; and
a reception resonance coil unit receiving electric power transmitted from the transmission resonance coil unit,
wherein at least one of the transmission resonance coil unit and the reception resonance coil unit corresponds to the resonance coil unit according to claim 7.