JP2013175673A - Non-contact power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power supply device capable of suppressing a harmonic component generated in a coil.SOLUTION: A non-contact power supply device (1) includes a pair of coils (11, 21) arranged via an air gap (30) and magnetic bodies (12, 22) provided on the rear surfaces of the coils respectively and supplies power between the pair of coils in a non-contact manner. At least one of the magnetic bodies has such a characteristic that an electrical conductivity in a plane direction orthogonal to an axial direction of the coil provided on the front surface of the magnetic body is higher than that in the axial direction.

Description

Translated fromJapanese

本発明は、非接触給電装置に関するものである。  The present invention relates to a non-contact power feeding device.

電磁誘導の相互誘導作用に基づき１次側から２次側に非接触で電力を供給する非接触給電装置において、１次側および２次側は、それぞれエアギャップ側から順に、コイル，磁心コア，ベースプレートを備え、コイルは渦巻き状に巻回されたフラット構造よりなり、磁心コア及びベースプレートはフラットな平板状をなし、磁心コアとベースプレートとの間に電気絶縁材が介装されている非接触給電装置が知られている（特許文献１）。  In a non-contact power feeding device that supplies electric power from the primary side to the secondary side in a non-contact manner based on the mutual induction action of electromagnetic induction, the primary side and the secondary side are respectively in order from the air gap side, a coil, a magnetic core, Non-contact power supply with a base plate, the coil has a flat structure wound in a spiral shape, the magnetic core and the base plate have a flat plate shape, and an electrical insulating material is interposed between the magnetic core and the base plate An apparatus is known (Patent Document 1).

特開２０１０−９３１８０号公報JP 2010-93180 A

上記従来技術では、１次側と２次側との間のギャップ変動や位置ずれによって結合係数が変化し、共振状態から外れた場合にはコイルに高調波成分が発生するが、従来技術の磁心コアは導電率の低いフェライトを使っているため、高調波成分のほとんどが送電されて放射ノイズとなり、これが車載機器に悪影響を与えるという問題がある。  In the above prior art, the coupling coefficient changes due to the gap fluctuation or misalignment between the primary side and the secondary side, and a harmonic component is generated in the coil when it is out of the resonance state. Since the core uses ferrite with low conductivity, there is a problem that most of the harmonic components are transmitted and become radiation noise, which adversely affects on-vehicle equipment.

本発明が解決しようとする課題は、コイルに発生する高調波成分を抑制できる非接触給電装置を提供することである。  The problem to be solved by the present invention is to provide a non-contact power feeding device that can suppress harmonic components generated in a coil.

本発明は、コイルの背面に配置する磁性体の軸方向の導電率に比べて軸方向に直交する面方向の導電率を高く設定することによって、上記課題を解決する。  This invention solves the said subject by setting the electrical conductivity of the surface direction orthogonal to an axial direction high compared with the electrical conductivity of the axial direction of the magnetic body arrange | positioned on the back surface of a coil.

本発明によれば、磁性体の軸方向に直交する面方向の導電率を軸方向の導電率よりも高くすることで、磁性体の主面方向に渦電流を発生させる。これにより当該渦電流が損失として消費され、その結果、高調波成分を抑制することができる。  According to the present invention, the eddy current is generated in the main surface direction of the magnetic body by making the conductivity in the plane direction orthogonal to the axial direction of the magnetic body higher than the conductivity in the axial direction. As a result, the eddy current is consumed as a loss, and as a result, harmonic components can be suppressed.

本発明の一実施の形態に係る非接触給電装置を示す断面図である。It is sectional drawing which shows the non-contact electric power feeder which concerns on one embodiment of this invention.図１の送電コイル（又は受電コイル）を示す斜視図である。It is a perspective view which shows the power transmission coil (or power receiving coil) of FIG.２０ｋＨｚの給電電流を基本成分として給電した場合に受電コイルに流れる電流波形（周波数成分）をシミュレーションしたグラフである。It is the graph which simulated the current waveform (frequency component) which flows into a receiving coil, when feeding with a 20kHz feeding current as a basic component.本発明の他の実施の形態に係る非接触給電装置の送電コイルを示す断面図である。It is sectional drawing which shows the power transmission coil of the non-contact electric power feeder which concerns on other embodiment of this invention.図４の送電コイルを示す平面図である。It is a top view which shows the power transmission coil of FIG.積層磁性コアと磁束遮蔽板との距離Ｚ_１を２０ｍｍと４０ｍｍにした場合の積層磁性コア２２の背面（コイル２１から５ｍｍの部分）の磁束密度の変化を観察したグラフである。It is a graph of observation of the change of the magnetic flux density of the back of the laminatedmagnetic cores 22 when the distance Z₁ to the laminated magnetic core and the magnetic flux shielding plate was 20mm and 40 mm (part of 5mm from the coil 21).磁性コアに入る磁束とこれにより発生する渦電流を示す斜視図である。It is a perspective view which shows the magnetic flux which enters a magnetic core, and the eddy current generated by this.本発明のさらに他の実施の形態に係る非接触給電装置の送電コイルを示す断面図である。It is sectional drawing which shows the power transmission coil of the non-contact electric power supply which concerns on other embodiment of this invention.図７Ａの７Ｂ部を拡大した断面図である。It is sectional drawing to which the 7B part of FIG. 7A was expanded.本発明のさらに他の実施の形態に係る非接触給電装置の送電コイルを示す断面図である。It is sectional drawing which shows the power transmission coil of the non-contact electric power supply which concerns on other embodiment of this invention.図８Ａの８Ｂ部を拡大した断面図である。It is sectional drawing to which the 8B part of FIG. 8A was expanded.本発明のさらに他の実施の形態に係る非接触給電装置の受電コイルと送電コイルを示す斜視図である。It is a perspective view which shows the receiving coil and power transmission coil of the non-contact electric power supply which concern on other embodiment of this invention.図９Ａの断面図及び一部拡大断面図である。It is sectional drawing of FIG. 9A, and a partially expanded sectional view.

図１は本発明の一実施の形態を適用した非接触給電装置１を示す断面図であり、
所定のエアギャップ３０を介して、受電コイル１０と送電コイル２０とが対面し、給電スタンドなどに設置される送電装置４０から、車両などに搭載されたバッテリ５０などの負荷に非接触で電力を供給し、充電するシステムなどに適用することができる。たとえば、給電スタンドの給電スペースの床面に送電コイル２０を設置し、車両の床裏に受電コイル１０を装着し、受電コイル１０が送電コイル２０に対面するように車両を給電スペースに駐車することで、給電装置４０→送電コイル２０→エアギャップ３０→受電コイル１０→バッテリ５０といった給電経路で充電することができる。FIG. 1 is a sectional view showing a non-contact power feeding device 1 to which an embodiment of the present invention is applied.
Thepower receiving coil 10 and thepower transmission coil 20 face each other through apredetermined air gap 30, and power is transmitted in a non-contact manner to a load such as abattery 50 mounted on a vehicle or the like from apower transmission device 40 installed in a power supply stand or the like. It can be applied to a system for supplying and charging. For example, thepower transmission coil 20 is installed on the floor surface of the power supply space of the power supply stand, thepower reception coil 10 is mounted on the floor behind the vehicle, and the vehicle is parked in the power supply space so that thepower reception coil 10 faces thepower transmission coil 20. Thus, charging can be performed through a power feeding path such as thepower feeding device 40 → thepower transmission coil 20 → theair gap 30 → thepower receiving coil 10 → thebattery 50.

図２は送電コイル２０を示す斜視図であり、本例では送電コイル２０とこれと対をなす受電コイル１０は同じ構造とされている。受電コイル１０及び送電コイル２０は、銅などの導体からなるコイル１１，２１をそれぞれ備える。本例のコイル１１，２１は、少なくともｘｙ平面上に巻回された偏平状コイルであり、図１に示すようにｘｙ平面上に１重（１段）で巻回されたもののほか、ｚ軸方向に複数重（複数段）巻回されたものも含まれる。また本例のコイル１１，２１は、図１に示すように平面視において渦巻状に巻回されたもののほか、平面視において楕円形状に巻回されたもの、正方形や長方形などの矩形状に巻回されたもの、或いは８の字形状に交差して巻回されたものも含まれる。本例のコイル１１，２１は、互いに短絡しないように導体の表面が絶縁被覆され、受電コイル１０にあってはその両端がそれぞれバッテリ５０の入力端子に接続され、送電コイル２０にあってはその両端がそれぞれ給電装置４０の入力端子に接続される。  FIG. 2 is a perspective view showing thepower transmission coil 20, and in this example, thepower transmission coil 20 and thepower reception coil 10 paired therewith have the same structure. Thepower receiving coil 10 and thepower transmitting coil 20 includecoils 11 and 21 made of a conductor such as copper, respectively. Thecoils 11 and 21 of this example are flat coils wound on at least the xy plane, and are wound in a single (one stage) on the xy plane as shown in FIG. Also included are those wound multiple times (multiple steps) in the direction. Thecoils 11 and 21 of the present example are wound in a spiral shape in a plan view as shown in FIG. 1, wound in an elliptical shape in a plan view, and wound in a rectangular shape such as a square or a rectangle. Also included are those that have been turned or wound so as to intersect the figure 8 shape. In thecoils 11 and 21 of this example, the surfaces of the conductors are insulated so as not to short-circuit each other, and both ends of thepower receiving coil 10 are connected to the input terminals of thebattery 50, respectively. Both ends are connected to input terminals of thepower feeding device 40, respectively.

受電コイル１０及び送電コイル２０の各コイル１１，２１の背面には、相手側の送電コイル２０又は受電コイル１０との間の磁界を調整する磁性コア１２，２２がコイル１１，２１の全面にわたって設けられている。さらに磁性コア１２，２２の背面には、それぞれ受電コイル１０および送電コイル２０からの磁界が受電コイル１０及び送電コイル２０の背面側に及ぶのを抑制する磁気遮蔽板１３，２３が設けられている。なお、受電コイル１０及び送電コイル２０の全体を保護するために、当該受電コイル１０及び送電コイル２０の全体を覆うカバー１４，２４がそれぞれ設けられている。  Magnetic cores 12 and 22 for adjusting a magnetic field between thereceiving coil 10 and thereceiving coil 10 on the other side are provided over the entire surfaces of thecoils 11 and 21 on the back surfaces of thecoils 11 and 21 of thereceiving coil 10 and the transmittingcoil 20. It has been. Further, on the back surfaces of themagnetic cores 12 and 22,magnetic shielding plates 13 and 23 are provided for suppressing the magnetic fields from thepower receiving coil 10 and thepower transmitting coil 20 from reaching the back surfaces of thepower receiving coil 10 and thepower transmitting coil 20, respectively. . In addition, in order to protect the whole receivingcoil 10 and thepower transmission coil 20, the covers 14 and 24 which cover the whole the said receivingcoil 10 and thepower transmission coil 20 are provided, respectively.

本例の磁性コア１２，２２自体は、磁気異方性を有する部材で構成され、コイル１１，２１の軸方向（図１に示すＺ方向）の電気導電率に比べて当該軸方向Ｚに直交する面方向（図１に示すＸ−Ｙ平面方向）の電気導電率が高く設定されている。ここで、コイルの軸方向Ｚの電気導電率とは、コイル１１，２１の軸方向に磁束が入った場合に当該磁束廻りに流れる渦電流の電気導電率をいい、軸方向Ｚに直行するＸ−Ｙ面方向の電気導電率とは、Ｘ−Ｙ面方向に磁束が入った場合に当該磁束廻りに流れる渦電流の電気導電率をいう。電気導電率σは、電流密度ベクトルｊ，電界ベクトルＥ，電気抵抗率ρとしたときに、σ（Ｓ／ｍ）＝ｊ／Ｅ＝１／ρの関係がある。  Themagnetic cores 12 and 22 themselves of this example are composed of members having magnetic anisotropy, and are orthogonal to the axial direction Z as compared with the electrical conductivity in the axial direction of thecoils 11 and 21 (Z direction shown in FIG. 1). The electric conductivity in the surface direction (XY plane direction shown in FIG. 1) is set high. Here, the electrical conductivity in the axial direction Z of the coil refers to the electrical conductivity of the eddy current that flows around the magnetic flux when the magnetic flux enters the axial direction of thecoils 11 and 21, and X that is orthogonal to the axial direction Z. The electrical conductivity in the −Y plane direction refers to the electrical conductivity of an eddy current that flows around the magnetic flux when a magnetic flux enters the XY plane. The electrical conductivity σ has a relationship of σ (S / m) = j / E = 1 / ρ, where current density vector j, electric field vector E, and electrical resistivity ρ.

ところで、送電コイル２０と受電コイル１０との間のエアギャップ３０が変動したり、これら送電コイル２０と受電コイル１０とが位置ズレしたりすることで結合係数が変化して共振状態から外れると、コイル１１，２１に高調波電流成分が発生する。また共振状態が維持されていても受電側の整流器等の影響により高調波電流成分が発生する。図３は、２０ｋＨｚの給電電流を基本成分として給電した場合に受電コイル１０に流れる電流波形（周波数成分）をシミュレーションしたグラフであり、基本周波数成分である２０ｋＨｚ以外にも３倍（６０ｋＨｚ）、５倍（１００ｋＨｚ）、７倍（１４０ｋＨｚ）といった奇数次の周波数成分が発生することが理解できる。  By the way, when theair gap 30 between thepower transmission coil 20 and thepower reception coil 10 fluctuates or thepower transmission coil 20 and thepower reception coil 10 are misaligned, the coupling coefficient changes and the resonance state is deviated. Harmonic current components are generated in thecoils 11 and 21. Even if the resonance state is maintained, a harmonic current component is generated due to the influence of the rectifier on the power receiving side. FIG. 3 is a graph simulating a current waveform (frequency component) flowing through thepower receiving coil 10 when a power supply current of 20 kHz is supplied as a basic component. In addition to the basic frequency component of 20 kHz, three times (60 kHz), 5 It can be understood that odd-order frequency components such as double (100 kHz) and seven times (140 kHz) are generated.

こうした高調波成分は空間ノイズを発生させ、車載電子機器等に対する放射ノイズとなる。この放射ノイズとなる高調波成分を抑制するために磁性コア１２，２２を電気導電率が高いアルミニウムなどで構成すると、磁性コア１２，２２の表面に渦電流が流れ、これが高調波成分の損失となって消費され、その結果放射ノイズを抑制することができる。しかしながら、磁性コア１２，２２を電気導電率が高い材料で構成すると、本来送電したい周波数成分の渦電流も流れてしまい、給電効率が低下するという問題がある。  Such harmonic components generate spatial noise and become radiation noise for an on-vehicle electronic device or the like. If themagnetic cores 12 and 22 are made of aluminum or the like having a high electrical conductivity in order to suppress the harmonic component that becomes the radiation noise, an eddy current flows on the surface of themagnetic cores 12 and 22, which causes a loss of the harmonic component. As a result, radiation noise can be suppressed. However, if themagnetic cores 12 and 22 are made of a material having a high electrical conductivity, an eddy current having a frequency component that is originally intended to be transmitted flows, which causes a problem that power supply efficiency is lowered.

これに対して、本例の磁性コア１２，２２は、コイル１１，２１の軸方向Ｚの電気導電率は低く、Ｘ−Ｙ平面方向の電気導電率は高い磁気異方性材にて構成しているので、コイル１１，２１の軸方向Ｚに対しては電気導電率が低い、すなわち軸方向Ｚに沿う磁束による渦電流は流れ難い一方で、コイル１１，２１のＸ−Ｙ面方向に対しては電気導電率が高い、すなわちＸ−Ｙ方向に沿う磁束による渦電流は流れ易い。その結果、本来送電したい周波数成分、すなわちコイル１１，２１の軸方向Ｚの磁束に影響を与えることなく（給電効率を低下させることなく）、放射ノイズの原因となる高調波成分、すなわちＸ−Ｙ面方向の磁束による渦電流を電流損失として消費することができる。  On the other hand, themagnetic cores 12 and 22 of this example are made of a magnetic anisotropic material having low electrical conductivity in the axial direction Z of thecoils 11 and 21 and high electrical conductivity in the XY plane direction. Therefore, the electrical conductivity is low with respect to the axial direction Z of thecoils 11 and 21, that is, eddy current due to the magnetic flux along the axial direction Z is difficult to flow, whereas with respect to the XY plane direction of thecoils 11 and 21. The electric conductivity is high, that is, an eddy current due to a magnetic flux along the XY direction tends to flow. As a result, the frequency component that is originally desired to be transmitted, that is, the harmonic component that causes radiation noise, that is, XY, without affecting the magnetic flux in the axial direction Z of thecoils 11 and 21 (without reducing the feeding efficiency). Eddy current due to the magnetic flux in the plane direction can be consumed as current loss.

本例の磁性コア１２，２２は、コイル１１，２１の軸方向Ｚの電気導電率に比べて当該軸方向Ｚに直交するＸ−Ｙ面方向の電気導電率が高く設定された磁気異方性を有する構造であれば、一つの部材が均一に磁気異方性を有するものであっても、あるいは複数の部材を組み合わせて部位ごとに磁気異方性を付加するようにしてもよい。  Themagnetic cores 12 and 22 of this example have a magnetic anisotropy in which the electrical conductivity in the XY plane direction orthogonal to the axial direction Z is set higher than the electrical conductivity in the axial direction Z of thecoils 11 and 21. If one structure has a uniform magnetic anisotropy, a plurality of members may be combined to add magnetic anisotropy to each part.

図４は、給電コイル２０の磁性コア２２を電気導電率が異なる複数の部材で構成した一例を示す断面図である。なお、受電コイル１０の磁性コア１２についても同様である。図示する磁性コア２２は、電気導電率が低いフェライトなどの材料で構成された低導電率部Ａと、電気導電率がフェライトより相対的に高い材料、たとえばアルミニウム、ファインメット（登録商標）などのナノ結晶軟磁性材料、パーマロイなどの材料で構成された高導電率部Ｂを有し、図４及び図５の平面図に示すように、コイル２１が巻回された真後ろに高導電率部Ｂがコイル２１の平面形状に沿ってドーナッツ状に配置され、それ以外は低導電率部Ａとされている。なお、電気導電率の大小は、フェライト＜パーマロイ＜ファインメット（登録商標）＜アルミニウムである。  FIG. 4 is a cross-sectional view showing an example in which themagnetic core 22 of thepower feeding coil 20 is composed of a plurality of members having different electrical conductivities. The same applies to themagnetic core 12 of thepower receiving coil 10. The illustratedmagnetic core 22 includes a low conductivity portion A made of a material such as ferrite having a low electrical conductivity, and a material having a relatively higher electrical conductivity than ferrite, such as aluminum and Finemet (registered trademark). As shown in the plan views of FIGS. 4 and 5, the high conductivity portion B is formed just behind thecoil 21 as shown in the plan views of FIGS. 4 and 5. Are arranged in a donut shape along the planar shape of thecoil 21, and the others are the low conductivity portions A. The electrical conductivity is: ferrite <permalloy <Finemet (registered trademark) <aluminum.

図４に点線で示すように、コイル２１による磁束は、コイル２１の中心領域と外周領域においてコイル２１の軸方向Ｚに沿って磁性コア２２に入ることになるので、このコイル２１の中心領域と外周領域に対面する磁性コアの領域Ａを電気導電率が相対的に低いフェライトで構成することで、本来送電したい周波数成分である軸方向Ｚの磁束に影響を与えることがなく、給電効率の低下が防止される。これに対して、コイル２１の真後ろに対面する磁性コア２２には、同図の点線で示すようにＸ−Ｙ面方向の磁束が入ることになるので、同図のＸ部の拡大断面図に示すように矢印で示す渦電流が流れ、放射ノイズの原因となる高調波成分であるＸ−Ｙ面方向の磁束による渦電流を電流損失として消費することができる。  As indicated by a dotted line in FIG. 4, the magnetic flux generated by thecoil 21 enters themagnetic core 22 along the axial direction Z of thecoil 21 in the central region and the outer peripheral region of thecoil 21. By configuring the magnetic core region A facing the outer peripheral region with ferrite having a relatively low electrical conductivity, it does not affect the magnetic flux in the axial direction Z, which is the frequency component to be originally transmitted, and the power supply efficiency is reduced. Is prevented. On the other hand, magnetic flux in the XY plane direction enters themagnetic core 22 facing just behind thecoil 21 as shown by the dotted line in the figure, and therefore, in the enlarged sectional view of the X part in the figure. As shown, eddy currents indicated by arrows flow, and eddy currents due to magnetic fluxes in the XY plane direction, which are harmonic components that cause radiation noise, can be consumed as current loss.

磁気コア２２のうち電気導電率が高い高導電率部Ｂは、電気導電率が低い低導電率部Ａのフェライトより電気導電率が高い、たとえばパーマロイ等の所定の電気導電率をもった磁性薄板材を複数積み重ねた積層磁性コア２２を用いることができる。積層磁性コア２２を構成する１枚の積層薄板材の厚さは、抑制目的とする高調波成分磁束のうち最低次数成分の表皮厚さ程度とすることができる。すなわち、抑制目的とする高調波成分磁束の角周波数域をω_１〜ω_２、積層磁性体の電気導電率をσ、透磁率をμとしたときに、積層磁性体を構成する１枚の磁性体の板厚δは、Of themagnetic core 22, the high conductivity part B having a high electrical conductivity has a higher electrical conductivity than the ferrite of the low conductivity part A having a low electrical conductivity, for example, a magnetic thin film having a predetermined electrical conductivity such as permalloy. A laminatedmagnetic core 22 in which a plurality of plate materials are stacked can be used. The thickness of one laminated thin plate material constituting the laminatedmagnetic core 22 can be set to the skin thickness of the lowest order component of the harmonic component magnetic flux to be suppressed. That is, when the angular frequency range of the harmonic component magnetic flux to be suppressed is ω₁ to ω₂ , the electrical conductivity of the laminated magnetic body is σ, and the magnetic permeability is μ, one piece of magnetism constituting the laminated magnetic body The body thickness δ is

［数１］
√（２／ω_１σμ）≦δ≦√（２／ω_２σμ）[Equation 1]
√ (2 / ω₁ σμ) ≦ δ ≦ √ (2 / ω₂ σμ)

で表すことができる。例えば、１００ｋＨｚ（＝ω／２π）の高調波成分を抑制目的とし、導電率が１５４Ｓ／ｍ，比透磁率（＝μ／１．２６×１０^−６）が３２０００であるパーマロイを積層材として用いる場合は、δ＝√｛（２／１０^５×２π×１５４×３２０００×１．２６×１０^−６）｝＝０．７１７ｍｍ程度とすることが望ましい。同様に、１ＭＨｚの高調波成分を抑制目的とし、上記パーマロイを積層材として用いる場合は、積層磁性体を構成する１枚の磁性体の板厚δは０．２２７ｍｍ程度とすることが望ましい。Can be expressed as For example, a permalloy having a conductivity of 154 S / m and a relative permeability (= μ / 1.26 × 10⁻⁶ ) of 32000 is used as a laminated material for the purpose of suppressing a harmonic component of 100 kHz (= ω / 2π). In this case, it is desirable to set δ = √ {(2/10⁵ × 2π × 154 × 32000 × 1.26 × 10⁻⁶ )} = 0.717 mm. Similarly, when the above-described permalloy is used as a laminated material for the purpose of suppressing a harmonic component of 1 MHz, the thickness δ of one magnetic body constituting the laminated magnetic body is desirably about 0.227 mm.

また、図４及び図５に示すように積層磁性コア２２の内径Ｒ_１及び外径Ｒ_２は、コイル２１の内径Ｒ_ｃｉ、コイル２１の外径Ｒ_ｃｏ、磁性コア２２と磁束遮蔽板２３との距離Ｚ_１、α，βを正の定数としたときに下記数式２で決まる所定量とすることができる。As shown in FIGS. 4 and 5, the inner diameter R₁ and the outer diameter R₂ of the laminatedmagnetic core 22 are the inner diameter R_{ci of} thecoil 21, the outer diameter R_co of thecoil 21, themagnetic core 22, the magneticflux shielding plate 23, and the like. When the distances Z₁ , α, and β are positive constants, the predetermined amount determined by the following formula 2 can be used.

［数２］
Ｒ_１＝Ｒ_ｃｉ＋αＺ_１
Ｒ_２＝Ｒ_ｃｏ−βＺ_１[Equation 2]
R₁ = R_ci + αZ₁
R₂ = R_co -βZ₁

図６Ａは、積層磁性コア２２と磁束遮蔽板２３との距離Ｚ_１を２０ｍｍと４０ｍｍにした場合の積層磁性コア２２の背面（コイル２１から５ｍｍの部分）の磁束密度の変化を観察したグラフである。この結果から、積層磁性コア２２と磁束遮蔽板２３との距離Ｚ_１が大きいほど、強い磁束が中心側に進入することが理解できる。そして、この磁束Ｚは積層磁性コア２２の面内に直交する成分を有するため、図６Ｂに示すように大きい渦電流を発生させようとする。Figure 6A is a graph of observing the change of the magnetic flux density of the back of the laminatedmagnetic cores 22 in the case where the distance_{Z 1} to the laminatedmagnetic core 22 and the magneticflux shielding plate 23 to 20mm and 40 mm (part of 5mm from the coil 21) is there. From this result, the larger the distance Z₁ to the laminatedmagnetic core 22 and the magneticflux shielding plate 23, it is understood that the strong magnetic flux enters the center side. And since this magnetic flux Z has a component orthogonal to the surface of the laminatedmagnetic core 22, it tries to generate a large eddy current as shown in FIG. 6B.

そのため本例では、この磁束Ｚを受ける部分には電気導電率が低いフェライトなどの磁性体を用い、積層磁性コア２２と磁束遮蔽板２３との距離Ｚ_１に応じて積層磁性コア２２の外径Ｒ_２を上記数２式のように設定することが望ましい。すなわち、積層磁性コア２２と磁束遮蔽板２３との距離Ｚ_１が大きいほど積層磁性コア２２の外径Ｒ_２を小さくして磁性コア２２の外周の低導電率部Ａの範囲を大きくし、積層磁性コア２２と磁束遮蔽板２３との距離Ｚ_１が小さいほど積層磁性コア２２の外径Ｒ_２を大きくして磁性コア２２の外周の低導電率部Ａの範囲を小さく設定することが望ましい。Therefore, in this example, a magnetic material such as ferrite having low electrical conductivity is used for the portion that receives the magnetic flux Z, and the outer diameter of the laminatedmagnetic core 22 is determined according to the distance Z₁ between the laminatedmagnetic core 22 and the magneticflux shielding plate 23. It is desirable to set R₂ as in Equation₂ above. That is, as the distance Z₁ between the laminatedmagnetic core 22 and the magneticflux shielding plate 23 is larger, the outer diameter R₂ of the laminatedmagnetic core 22 is reduced to increase the range of the low conductivity portion A on the outer periphery of themagnetic core 22. it is desirable to set a small range of low conductivity portion a of the outer periphery of the magnetic core 22 a distance by increasing the outer diameter R₂ of Z as₁ is smaller laminatedmagnetic core 22 of themagnetic core 22 and the magneticflux shielding plate 23.

磁性コア２２を上述した積層磁性コア２２で構成するに際し、電気導電率の異なる積層薄板材を積層させてもよい。図７Ａは、本発明のさらに他の実施の形態に係る送電コイル２０を示す断面図であり、受電コイル１０についても同様である。図７Ｂは図７Ａの７Ｂ部を拡大した断面図であり、本例では、積層磁性コア２２の積層方向に対して中心側に電気導電率が高いファインメット（登録商標）などの高導電率磁性材料が積層され、積層方向の上側に電気伝導率がファインメット（登録商標）より低いパーマロイなどの低導電率磁性材料が積層されている。これにより、積層磁性コア２２の表面に集中しがちな磁束を中心側にも分散させることができ、より渦電流の消費による高周波成分の除去が可能となる。  When themagnetic core 22 is composed of the laminatedmagnetic core 22 described above, laminated thin plate materials having different electrical conductivities may be laminated. FIG. 7A is a cross-sectional view showing apower transmission coil 20 according to still another embodiment of the present invention, and the same applies to thepower reception coil 10. FIG. 7B is an enlarged cross-sectional view of aportion 7B of FIG. 7A. In this example, high conductivity magnetism such as Finemet (registered trademark) having high electrical conductivity on the center side with respect to the lamination direction of the laminatedmagnetic core 22 is shown. The materials are stacked, and a low-conductivity magnetic material such as Permalloy having a lower electrical conductivity than Finemet (registered trademark) is stacked on the upper side in the stacking direction. As a result, the magnetic flux that tends to concentrate on the surface of the laminatedmagnetic core 22 can be dispersed to the center side, and it becomes possible to remove the high-frequency component due to the consumption of eddy current.

また、これに代えて或いはこれとともに、積層方向の上側にパーマロイなどの低導電率磁性材料を積層し、積層磁性コア２２のコイル２１から離れた側にパーマロイより電気導電率が高いファインメット（登録商標）などの高導電率磁性材料を積層してもよい。これにより、コイル２１からの漏れ磁束又は鎖交磁束の廻り込み磁束による損失が低減できることになる。  Alternatively, or together with this, a low-conductivity magnetic material such as permalloy is laminated on the upper side in the lamination direction, and finemet (registered) having higher electric conductivity than permalloy on the side away from thecoil 21 of the laminatedmagnetic core 22. A high conductivity magnetic material such as a trademark may be laminated. Thereby, the loss by the leakage magnetic flux from thecoil 21 or the wraparound magnetic flux of the interlinkage magnetic flux can be reduced.

磁性コア２２を上述した積層磁性コア２２で構成し、電気導電率の異なる積層薄板材を積層させるに際し、さらに改変してもよい。図８Ａは、本発明のさらに他の実施の形態に係る送電コイル２０を示す断面図であり、受電コイル１０についても同様である。図８Ｂは図８Ａの８Ｂ部を拡大した断面図であり、本例では、積層磁性コア２２の積層方向に対して上側及び下側に、中心側に対して電気導電率が低いフェライトなどの低導電率磁性材料が積層され、中心側にフェライトより電気導電率が高いファインメット（登録商標）やパーマロイなどの高導電率磁性材料が積層されている。  Themagnetic core 22 may be composed of the above-described laminatedmagnetic core 22 and further modified when the laminated thin plate materials having different electric conductivity are laminated. FIG. 8A is a cross-sectional view showing apower transmission coil 20 according to still another embodiment of the present invention, and the same applies to thepower reception coil 10. FIG. 8B is an enlarged cross-sectional view of aportion 8B of FIG. 8A. In this example, the laminatedmagnetic core 22 has a low electrical conductivity, such as a ferrite having a low electrical conductivity with respect to the central side, on the upper side and the lower side in the stacking direction. A conductive magnetic material is laminated, and a high-conductivity magnetic material such as Finemet (registered trademark) or permalloy having a higher electric conductivity than ferrite is laminated on the center side.

これにより、コイル２１からの漏れ磁束又は鎖交磁束の廻り込み磁束による損失が低減できることになる。なお、フェライトなどの低導電率磁性材料を積層するのは上側又は下側のいずれか一方でもよい。  Thereby, the loss by the leakage magnetic flux from thecoil 21 or the wraparound magnetic flux of the interlinkage magnetic flux can be reduced. Note that the low conductivity magnetic material such as ferrite may be laminated on either the upper side or the lower side.

以上の実施の形態では、図１及び２に示すように渦巻状コイルを有する受電コイル１０と給電コイル２０とを上下に縦置きするタイプの非接触給電装置について説明したが、本発明は図９Ａ及び９Ｂに示す横置きタイプの非接触給電装置にも適用することができる。本例の横置きタイプの非接触給電装置とは、直方体形状の磁性コア１２，２２のそれぞれに、図９Ａに示すようにコイル１１，２１を巻回することで受電コイル１０と給電コイル２０が構成されたものであり、給電時にはこれら受電コイル１０と給電コイル２０とを、図９Ｂに示すように磁束方向に対して互いに横に並べる。これにより給電コイルから受電コイルへ給電されるが、この種の横置きタイプの受電コイル１０及び給電コイル２０についても上述した各実施の形態を適用することができる。  In the above embodiment, as shown in FIGS. 1 and 2, the non-contact power feeding device of the type in which thepower receiving coil 10 having the spiral coil and thepower feeding coil 20 are vertically arranged has been described. And 9B can also be applied to the horizontal type non-contact power feeding device. In the horizontal type non-contact power feeding device of this example, thecoils 11 and 21 are wound around the rectangularmagnetic cores 12 and 22 as shown in FIG. Thepower receiving coil 10 and thepower feeding coil 20 are arranged next to each other with respect to the direction of magnetic flux as shown in FIG. 9B. As a result, power is supplied from the power supply coil to the power reception coil, but the above-described embodiments can be applied to this type of horizontally installedpower reception coil 10 andpower supply coil 20.

さらに、図示は省略するが、磁束は積層磁性コア１２，２２の表面に集中しがちであるため、上述したように表面側に電気導電率が相対的に低い低導電率磁性材料を採用することに代えて或いはこれとともに、積層磁性コア１２，２２の中央側ほど積層材の板厚を厚くするか、又はコイル１１，２１から離れるほど積層材の板厚を厚くしてもよい。  Furthermore, although illustration is omitted, since the magnetic flux tends to be concentrated on the surfaces of the laminatedmagnetic cores 12 and 22, a low-conductivity magnetic material having a relatively low electrical conductivity is employed on the surface side as described above. Instead of or together with this, the thickness of the laminated material may be increased toward the center of the laminatedmagnetic cores 12 and 22, or the thickness of the laminated material may be increased as the distance from thecoils 11 and 21 increases.

以上のように、本例の磁性コア１２，２２は、コイル１１，２１の軸方向Ｚの電気導電率は低く、Ｘ−Ｙ平面方向の電気導電率は高い磁気異方性材にて構成しているので、軸方向Ｚに沿う磁束による渦電流は流れ難い一方で、Ｘ−Ｙ方向に沿う磁束による渦電流は流れ易い。その結果、本来送電したい周波数成分、すなわちコイル１１，２１の軸方向Ｚの磁束に影響を与えることなく（給電効率を低下させることなく）、放射ノイズの原因となる高調波成分、すなわちＸ−Ｙ面方向の磁束による渦電流を電流損失として消費することができる。  As described above, themagnetic cores 12 and 22 of the present example are made of a magnetic anisotropic material having a low electrical conductivity in the axial direction Z of thecoils 11 and 21 and a high electrical conductivity in the XY plane direction. Therefore, while the eddy current due to the magnetic flux along the axial direction Z hardly flows, the eddy current due to the magnetic flux along the XY direction easily flows. As a result, the frequency component that is originally desired to be transmitted, that is, the harmonic component that causes radiation noise, that is, XY, without affecting the magnetic flux in the axial direction Z of thecoils 11 and 21 (without reducing the feeding efficiency). Eddy current due to the magnetic flux in the plane direction can be consumed as current loss.

また本例の非接触給電装置１では、各磁性コア１２，２２の背面に磁束遮蔽体１３，２３が設けられているので、受電コイル１０および送電コイル２０からの磁界が受電コイル１０及び送電コイル２０の背面側に及ぶのを抑制することができる。  Moreover, in the non-contact electric power feeder 1 of this example, since the magneticflux shielding bodies 13 and 23 are provided in the back surface of eachmagnetic core 12 and 22, the magnetic field from the receivingcoil 10 and thepower transmission coil 20 is received by the receivingcoil 10 and the power transmission coil. 20 can be suppressed from reaching the back side.

また本例の非接触給電装置１では、各磁性コア１２，２２は、コイル１１，２１の軸方向に複数の磁性体を積層した積層磁性コア１２，２２を含むので、各磁性体の厚さや電気導電率を設定することで、除去したい高周波成分を選択することができる。  Moreover, in the non-contact electric power feeder 1 of this example, since eachmagnetic core 12 and 22 includes the lamination | stackingmagnetic core 12 and 22 which laminated | stacked several magnetic bodies in the axial direction of thecoils 11 and 21, thickness of each magnetic body or By setting the electrical conductivity, it is possible to select a high frequency component to be removed.

また本例の非接触給電装置１では、積層磁性コア１２，２２は、コイル側に積層された磁性体の電気導電率に比べて、積層方向の中心側の磁性体の電気導電率の方が高い特性を有するので、積層磁性コア２２の表面に集中しがちな磁束を中心側にも分散させることができ、より渦電流の消費による高周波成分の除去が可能となる。  Moreover, in the non-contact electric power feeder 1 of this example, the laminatedmagnetic cores 12 and 22 have the electric conductivity of the magnetic body on the center side in the stacking direction compared to the electric conductivity of the magnetic body stacked on the coil side. Since it has high characteristics, it is possible to disperse the magnetic flux that tends to concentrate on the surface of the laminatedmagnetic core 22 to the center side, and it is possible to remove high-frequency components due to more eddy current consumption.

また本例の非接触給電装置１では、積層磁性コア１２，２２は、コイル側に積層された磁性体の板厚に比べて、積層方向の中心側の磁性体の板厚の方が厚いので、コイル２１からの漏れ磁束又は鎖交磁束の廻り込み磁束による損失が低減できることになる。  Moreover, in the non-contact electric power feeder 1 of this example, since the laminatedmagnetic cores 12 and 22 are thicker than the magnetic material laminated on the coil side, the magnetic material on the center side in the lamination direction is thicker. The loss due to the leakage magnetic flux from thecoil 21 or the flux wraparound magnetic flux can be reduced.

また本例の非接触給電装置１では、積層磁性コア１２，２２を構成する１枚の磁性体の板厚δは、抑制目的とする高調波成分磁束の角周波数域をω_１〜ω_２、前記積層磁性体の導電率をσ、透磁率をμとしたときに、
√（２／ω_１σμ）≦δ≦√（２／ω_２σμ）
であるので、除去目的とする高調波成分を効率よく除去することができる。Moreover, in the non-contact electric power feeder 1 of this example, plate | board thickness (delta) of the one magnetic body which comprises the lamination | stackingmagnetic cores 12 and 22 is the angular frequency range of the harmonic component magnetic flux for suppression, (omega)_1- (omega)₂ , When the conductivity of the laminated magnetic material is σ and the permeability is μ,
√ (2 / ω₁ σμ) ≦ δ ≦ √ (2 / ω₂ σμ)
Therefore, the harmonic component to be removed can be efficiently removed.

また本例の非接触給電装置１では、積層磁性コア１２，２２の外径Ｒ_２が、磁束遮蔽体１３，２３と積層磁性コア１２，２２との距離をＺ_１、α，βを正の定数としたときに、Ｒ_２＝Ｒ_ｃｏ−βＺ_１を満足するので、距離Ｚ_１に応じて高調波成分を効率よく除去することができる。In the non-contact power feeding device 1 of this example, the outer diameter R₂ of the laminatedmagnetic cores 12 and 22 is such that the distance between the magnetic flux shields 13 and 23 and the laminatedmagnetic cores 12 and 22 is Z₁ and α and β are positive. Since R₂ = R_co −βZ₁ is satisfied when the constant is set, harmonic components can be efficiently removed according to the distance Z₁ .

上記磁性コア１２，２２は本発明に係る磁性体に相当する。  Themagnetic cores 12 and 22 correspond to a magnetic body according to the present invention.

１…非接触給電装置
１０…受電コイル
１１…コイル
１２…磁性コア
１３…磁気遮蔽板
１４…カバー
２０…送電コイル
２１…コイル
２２…磁性コア
２３…磁気遮蔽板
２４…カバー
３０…エアギャップDESCRIPTION OF SYMBOLS 1 ... Non-contactelectric power feeder 10 ...Power receiving coil 11 ...Coil 12 ...Magnetic core 13 ... Magnetic shieldingboard 14 ...Cover 20 ...Power transmission coil 21 ...Coil 22 ...Magnetic core 23 ... Magnetic shieldingboard 24 ...Cover 30 ... Air gap

Claims (7)

Translated fromJapanese

エアギャップを介して配置される一対のコイルと、
前記各コイルの背面にそれぞれ設けられた磁性体と、を備え、
前記一対のコイル間を非接触で給電する非接触給電装置において、
前記磁性体の少なくとも一方は、当該磁性体の前面に設けられた前記コイルの軸方向の電気導電率に比べて当該軸方向に直交する面方向の電気導電率が高い特性を有する非接触給電装置。A pair of coils arranged through an air gap;
A magnetic body provided on the back of each coil,
In the non-contact power feeding device that feeds power between the pair of coils in a non-contact manner,
At least one of the magnetic bodies has a characteristic that the electrical conductivity in the plane direction perpendicular to the axial direction is higher than the electrical conductivity in the axial direction of the coil provided on the front surface of the magnetic body. . 前記各磁性体の背面に磁束遮蔽体が設けられている請求項１に記載の非接触給電装置。  The non-contact electric power feeder of Claim 1 with which the magnetic flux shielding body is provided in the back surface of each said magnetic body. 前記磁性体は、前記コイルの軸方向に複数の磁性体を積層した積層磁性体を含む請求項１又は２に記載の非接触給電装置。  The non-contact power feeding device according to claim 1, wherein the magnetic body includes a laminated magnetic body in which a plurality of magnetic bodies are laminated in an axial direction of the coil. 前記積層磁性体は、前記コイル側に積層された磁性体の電気導電率に比べて、積層方向の中心側の磁性体の電気導電率の方が高い特性を有する請求項３に記載の非接触給電装置。  4. The non-contact according to claim 3, wherein the laminated magnetic body has a characteristic that the electrical conductivity of the magnetic body on the center side in the laminating direction is higher than the electrical conductivity of the magnetic body laminated on the coil side. Power supply device. 前記積層磁性体は、前記コイル側に積層された磁性体の板厚に比べて、積層方向の中心側の磁性体の板厚の方が厚い請求項３に記載の非接触給電装置。  4. The non-contact power feeding device according to claim 3, wherein the laminated magnetic body has a thicker magnetic body on the center side in the laminating direction than a magnetic body laminated on the coil side. 前記積層磁性体を構成する１枚の磁性体の板厚δは、抑制目的とする高調波成分磁束の角周波数域をω_１〜ω_２、前記積層磁性体の導電率をσ、透磁率をμとしたときに、
√（２／ω_１σμ）≦δ≦√（２／ω_２σμ）
である請求項３〜５のいずれか一項に記載の非接触給電装置。The plate thickness δ of one magnetic body constituting the laminated magnetic body is ω₁ to ω₂ in the angular frequency range of the harmonic component magnetic flux to be suppressed, the conductivity of the laminated magnetic body is σ, and the magnetic permeability is When μ is
√ (2 / ω₁ σμ) ≦ δ ≦ √ (2 / ω₂ σμ)
The contactless power feeding device according to any one of claims 3 to 5. 前記コイルは、内径をＲ_ｃｉ、外径をＲ_ｃｏとする円環形に形成され、
前記積層磁性体は、内径をＲ_１、外径をＲ_２とする円環形に形成され、
前記磁束遮蔽体と前記積層磁性体との距離をＺ_１、α，βを正の定数としたときに、下記式が成立する請求項３〜６のいずれか一項に記載の非接触給電装置。
Ｒ_１＝Ｒ_ｃｉ＋αＺ_１
Ｒ_２＝Ｒ_ｃｏ−βＺ_１The coil is formed in an annular shape having an inner diameter R_ci and an outer diameter R_co ,
The laminated magnetic body is formed in an annular shape having an inner diameter R₁ and an outer diameter R₂ .
The magnetic flux shielding member and the laminated magnetic body and Z₁ a_distance, alpha, when a positive constant beta, non-contact power feeding device according to any one of claims 3-6 in which the following expression is established .
R₁ = R_ci + αZ₁
R₂ = R_co -βZ₁

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