JP2004228068A

JP2004228068A - Electromagnetic induction heating device

Info

Publication number: JP2004228068A
Application number: JP2003202467A
Authority: JP
Inventors: Hideo Tomita; 英雄富田; Shuji Obata; 修二小畑; Sunao Hasegawa; 直長谷川; Kunihiko Suzuki; 邦彦鈴木
Original assignee: Tokyo Denki University
Current assignee: Tokyo Denki University
Priority date: 2002-11-26
Filing date: 2003-07-28
Publication date: 2004-08-12
Anticipated expiration: 2023-07-28
Also published as: JP4155884B2

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately set a generating region of an eddy current to match the shape of a surface to be heated and uniformly heat the whole of the surface to be heated in an electromagnetic induction heating device. <P>SOLUTION: An electromagnetic head portion 1 for generating alternating lines of magnetic force M to perform induction heating has a core 2 to be an orthogonal magnetic core and a heating coil 3 wound around its outer periphery. The core 2 has a facing portion 5 for facing a surface to be heated 4a of a conductive heating member 4 and an opposite portion 6 of its opposite side, the facing portion 5 formed in a shape in which the cross-sectional shape of the facing portion 5 is matched to the surface to be heated 4a. A line of magnetic force passing area Am and a path of the eddy current on the surface 4a are also matched to the heating shape of the surface 4a. Accordingly, it is possible to uniform the induction heating by applying the eddy current with less bias in the entire shape of the surface 4a and perform a variety of heating just as designed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、導電性発熱部材に対して誘導加熱を行う電磁誘導加熱装置に関する。
【０００２】
【従来の技術】
金属などの導電性物体を加熱する有効な方法の一つとして電磁誘導作用を利用した誘導加熱がある。これは交番する磁界中に導電性発熱部材が存在する場合、電磁誘導作用によって物体内に起電力が生じ、それにより物体内に誘導電流が流れてＩ^２Ｒのジュール熱を発生することを利用し導電性発熱部材を所定の温度にまで加熱するものである。
【０００３】
従来より、被加熱表面が平面となっている導電性発熱部材に対して誘導加熱を行う構成としては、同一平面上で渦巻き状に形成されたコイルを被加熱表面に対し平行かつ近接に配置させ、３０ｋＨｚ程度の高周波電流を供給することによりその被加熱表面に交番する磁力線を通過させて誘導加熱するものがある（たとえば、特許文献１参照）。
【０００４】
また他の構成として、磁性体材料で細長い円柱形状に形成した磁心の外周にコイルを巻き付けたものがあり、この一方の端部を被加熱表面に対向させてほぼ直交するよう配置し、その対向側の端部から被加熱表面へほぼ直交する方向に交番磁力線を通過させて誘導加熱するようになっている。
【０００５】
【特許文献１】
特開平８−７３８１８号公報
【０００６】
【発明が解決しようとする課題】
しかしながら、上記のようなコイルを平面渦巻き状に形成したものと円柱形状の磁心にコイルを巻き付けたもののどちらの構成も、磁力線を通過させる領域は円形に限られるものとなっていた。
【０００７】
磁力線の通過領域が被加熱表面の形状と一致しない場合には、磁力線の通過が不十分で渦電流が少なく十分に誘導加熱されない箇所が存在するか、または被加熱表面の縁部などに渦電流が集中して過剰に加熱させてしまい、その結果、被加熱表面全体での加熱状態が不均一となって目的の加熱形状が損なわれる問題がある。
【０００８】
本発明の目的は、被加熱表面の形状に合わせて渦電流の発生領域を適切に設定し、被加熱表面を目的の形状に加熱できる電磁誘導加熱装置を提供することにある。
【０００９】
【課題を解決するための手段】
本発明の電磁誘導加熱装置は、導電性発熱部材に交番磁力線を通過させて発生する渦電流のジュール熱により導電性発熱部材を誘導加熱するものであって、交流電流供給部と、導電性発熱部材の被加熱表面に対向して被加熱表面の形状に適合する断面形状の対向部を備える高透磁率の直交磁心と、直交磁心の外周に巻き付けられて交流電流供給部から交流電流が供給される加熱コイルとを有しており、加熱コイルの周囲に発生した交番磁力線を、直交磁心の対向部から被加熱表面に対してほぼ直交する方向で導電性発熱部材に加熱設計の必要量に対応して通過させることを特徴とする。
【００１０】
本発明の電磁誘導加熱装置は、導電性発熱部材に交番磁力線を通過させて発生する渦電流のジュール熱により導電性発熱部材を誘導加熱するものであって、交流電流供給部と、導電性発熱部材の被加熱表面に対向して設計された、すなわち加熱部の配置と面積と強度が調整された複数の高透磁率の直交磁心と、複数の直交磁心の少なくとも１つの外周に巻き付けられて交流電流供給部から交流電流が供給される加熱コイルとを有しており、加熱コイルの周囲に発生した交番磁力線を、直交磁心から被加熱表面に対してほぼ直交する方向で導電性発熱部材に通過させることを特徴とする。
【００１１】
本発明の電磁誘導加熱装置は、複数の直交磁心は被加熱表面の形状に合わせて配置されていることを特徴とする。
【００１２】
本発明にあっては、被加熱表面の形状に合わせて各直交磁心を配置できることにより、被加熱表面の形状全体に偏りなく渦電流を流して被加熱表面全体の均一加熱を図ることができる。
【００１３】
本発明の電磁誘導加熱装置は、加熱コイルは複数の直交磁心に対してどれも同じ方向廻りで巻き付けられていることを特徴とする。
【００１４】
本発明の電磁誘導加熱装置は、加熱コイルは複数の直交磁心の少なくとも一つに対して他のものと逆方向廻りで巻き付けられていることを特徴とする。
【００１５】
本発明の電磁誘導加熱装置は、導電性発熱部材に交番磁力線を通過させて発生する渦電流のジュール熱により導電性発熱部材を誘導加熱するものであって、交流電流供給部と、導電性発熱部材の被加熱表面に対向する対向部を備える高透磁率の直交磁心と、直交磁心の対向部の反対側に配置して前記交番磁力線を収束する磁力線収束磁心と、直交磁心の外周に巻き付けられて交流電流供給部から交流電流が供給される加熱コイルとを有しており、加熱コイルの周囲に発生した交番磁力線を、直交磁心の対向部から被加熱表面に対してほぼ直交する方向で導電性発熱部材に通過させた後、磁力線収束磁心を介して直交磁心に収束させることを特徴とする。
【００１６】
本発明にあっては、磁力線収束磁心が磁力線を収束することでその通過経路を被加熱表面の形状に対応した経路に整形できるため、渦電流の経路も形状に対応させて加熱の均一化を図ることができる。
【００１７】
本発明の電磁誘導加熱装置は、交番磁力線を捕捉して通過させる磁力線捕捉部材が直交磁心または磁力線収束磁心の周囲に配置されていることを特徴とする。
【００１８】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて詳細に説明する。
【００１９】
（実施の形態１）
図１は本発明の第１の実施の形態である電磁誘導加熱装置が備える電磁ヘッド部とそれにより誘導加熱されている状態の導電性発熱部材の斜視図であり、図２は電磁誘導加熱装置の電気回路を示すブロック図であり、図３はその導電性発熱部材に流れる渦電流の経路を図１における矢視Ｘから見た図である。本実施の形態の電磁誘導加熱装置は、図１に示すように誘導加熱を行うための交番磁力線Ｍを発生する電磁ヘッド部１を有しており、この電磁ヘッド部１は直交磁心であるコア２とその外周に巻き付けられる加熱コイル３を有している。
【００２０】
コア２は、強磁性材料であるフェライト、鉄、化合物などの高透磁率を持った材質とし、被加熱体である導電性発熱部材４の被加熱表面４ａに対して対向させる対向部５と、その反対側の反対部６を備えた直方体の形状に形成されている。図示してはいないが、通常この電磁ヘッド部１は、樹脂等のような非導電体かつ非磁性体の材質で形成したケース内に収容されて用いられることになる。
【００２１】
電磁誘導加熱装置７は、図２に示すように、電磁ヘッド部１および操作スイッチ８を備えるヘッド収容部９と、電源ユニット１０および高周波発生器１１および加熱時間設定器１２を備える本体部１３（交流電流供給部）とを有しており、ヘッド収容部９と本体部１３とは給電リッツ線１４を介して接続されている。
【００２２】
操作スイッチ８は電磁ヘッド部１と同じケースに設けられてヘッド収容部９を構成しており、操作者が作動開始の操作を入力できるようになっている。電源ユニット１０はＡＣコード１５を介して外部の交流電源１６に接続されており、供給された交流電力を直流電力に整流して以下の他の回路に供給するようになっている。高周波発生器１１は給電リッツ線１４を介して加熱コイル３に接続されており、たとえば２０〜３０ｋＨｚ程度の高周波の交流電流を発生して加熱コイル３に供給するようになっている。加熱時間設定器１２は１回の加熱操作に要する加熱コイル３への通電時間を設定するものであり、給電リッツ線１４を介して操作スイッチ８から通電操作の信号を受けてから設定された通電時間だけ高周波発生器１１に制御信号を出力するようになっている。高周波発生器１１はこの制御信号を受けている間、すなわち設定された通電時間だけ加熱コイル３に交流電流を供給する。加熱時間設定器１２は通電時間の設定を任意に調整できるようになっている。
【００２３】
以上の構成の電磁誘導加熱装置７の操作について説明する。操作者はヘッド収容部９を移動させて図１に示すようにコア２を被加熱表面４ａに向けて直交させつつ近接するよう配置し、この状態で操作スイッチ８をオン操作することにより導電性発熱部材４に対する誘導加熱を開始することになる。加熱時間設定器１２に設定された通電時間だけ加熱コイル３に交流電流が供給され、その間に図示するようにコア２を中心とした加熱コイル３の周囲に交番する磁力線Ｍが発生する。
【００２４】
コア２は磁力線Ｍの空間分布を制御する磁路、すなわち内部に磁力線Ｍを収束して通過させる磁束路として機能し、コア２の対向部５の対向面から被加熱表面４ａに対して磁力線Ｍを直交して通過させるようになっている。したがって対向部５の対向面の断面形状を変えることで磁力線通過領域Ａｍを任意に設定することができる。
【００２５】
図３に示すように、磁力線通過領域Ａｍに交番磁力線Ｍが通過することで、磁力線通過領域Ａｍを含むその周囲には電磁誘導効果により渦電流Ｉが生じることになる。この渦電流Ｉが流れることでジュール熱が発生し、それにより導電性発熱部材４に対する誘導加熱が行われることになる。
【００２６】
図１７は、比較例として、コアを備えずに平面渦巻き状に形成された加熱コイル１０３のみで構成する電磁ヘッド部１０１と、それに平行に配置されて誘導加熱されている状態の導電性発熱部材４の斜視図であり、図１８はその導電性発熱部材４に流れる渦電流Ｉの経路を示した図である。図１７において導電性発熱部材４の被加熱表面４ａは、長辺が加熱コイル１０３の直径よりも十分に長く、短辺が加熱コイル１０３の直径より少しだけ長い長方形に形成されている。
【００２７】
この構成の場合、加熱コイル１０３は十分な本数の磁力線Ｍを得るために何周にも廻して巻く必要があり、そのため加熱コイル１０３が被加熱表面４ａに対して磁力線Ｍを通過させる領域Ａｍは、図示するように広い面積を要するほぼ円形の形状とならざるを得ない。しかし実際の被加熱表面４ａは円形以外の多角形状である場合が多く、つまり被加熱表面４ａの形状と磁力線通過領域Ａｍの形状とが大きく相違してしまう場合が多い。
【００２８】
図１８に示すように磁力線通過領域Ａｍが被加熱表面４ａの形状と一致しない場合には、渦電流Ｉが局所的に流れずに十分に誘導加熱されない箇所４ｂが存在したり、また磁力線通過領域Ａｍに近接している縁部４ｃなどには渦電流Ｉが集中して過剰に加熱させてしまい、その結果加熱状態が不均一となって大きく温度ムラができてしまう問題がある。また特に図１７に示すようなコアを備えずに平面渦巻き状に形成された加熱コイル１０３のみで構成する電磁ヘッド部１０１の場合には、平面渦巻き状の中心位置において局所的に磁力線Ｍの通過量が少なくなってしまい、そのため図１８に示すように磁力線通過領域Ａｍは中心に穴のあいた円環形状となって加熱状態を不均一にしてしまう要因となっている。
【００２９】
これに対して図１に示す本実施の形態の電磁ヘッド部１の場合は、コア２の対向部５の断面形状が被加熱表面４ａの形状に適合していることから、図３に示すように被加熱表面４ａの形状全体に偏りなく渦電流Ｉを流すことができる。
【００３０】
（実施の形態２）
図４は本発明の第２の実施の形態である電磁誘導加熱装置の電磁ヘッド部とそれにより誘導加熱されている状態の導電性発熱部材の斜視図であり、図５は本実施の形態の電磁ヘッド部２１により導電性発熱部材４に流れる渦電流Ｉのある瞬間における経路を示した図である。本実施の形態の電磁誘導加熱装置において、図４に示すように電磁ヘッド部２１は相互に並列に配置された３本の直交心部（直交磁心）２２ａ〜２２ｃで構成するコア２２と、それらの外周に巻き付けられた加熱コイル２３とを有している。
【００３１】
各直交心部２２ａ〜２２ｃは、被加熱表面４ａに対して対向させる対向部２５と、その反対側の反対部２６を備えた直方体の形状に形成されたものであり、３本が被加熱表面４ａの形状に合わせて相互に均等な間隔を設けるよう配置されている。また各直交心部２２ａ〜２２ｃに対応する磁力線通過領域Ａｍと被加熱表面４ａの各縁部との間の間隔については、図示するように均等な間隔とする以外にも、縁部における渦電流Ｉの集中を避けるために少し大きめの間隔を設ける配置としてもよい。このようにして各直交心部２２ａ〜２２ｃは、被加熱表面４ａの形状に合わせて適合して配置された状態となっている。なお、図中に示す各直交心部２２ａ〜２２ｃは直方体形状となっているが、その他にも円柱形状や、他の多角形の角柱形状としてもよい。
【００３２】
加熱コイル２３は図中両端の直交心部２２ａ，２２ｃに対して同じ左廻り方向に、中央の直交心部２２ｂには逆の右回り方向に、それぞれ同じ回数だけ巻き付けられている。これらの直交心部２２ａ〜２２ｃと加熱コイル２３は、図示しないケース内に収容されることで、お互いの配置関係が維持されるようになっている。
【００３３】
上記の構成によれば、被加熱表面４ａの形状に合わせて各直交心部２２ａ〜２２ｃを適合して配置していることにより、被加熱表面４ａの形状全体に偏りなく渦電流Ｉを流すことができるといった上記第１の実施の形態と同様の効果が得られる。さらに本実施の形態においては、隣り合う直交心部どうしで逆方向に磁力線Ｍを通過させていることにより、以下に説明するように被加熱表面４ａ上の加熱領域に対して効果的な誘導加熱を行うことができる。
【００３４】
比較例として図１に示す上記第１の実施の形態のように、被加熱表面４ａの形状が長方形のように長い形状であってコア２の対向部５もまたそれと相似する長い形状である場合には、長手方向の渦電流が均一化され温度ムラが少なくなる。
【００３５】
図５、図６はコアの磁極の組み合わせで加熱形状を変化させる方法を示す。本実施の形態の電磁ヘッド部２１によれば、図４に示すように中央の直交心部２２ｂに常に他の両端２つの直交心部２２ａ，２２ｃと逆の方向に磁力線Ｍが通過するため、３本の直交心部２２ａ〜２２ｃと導電性発熱部材４とがほぼループ形状の磁路を２つ並列に形成することになり、外部への磁力線Ｍの漏出を抑制する効果が向上するようになる。そのため磁力線Ｍが広い範囲へ拡散するのを抑えて被加熱表面４ａに対し磁力線Ｍを集中通過させて加熱効率を向上できるとともに、図中の上方側すなわち操作者側へ向かう磁力線Ｍの漏出を抑制できるようになっている。
【００３６】
なお各直交心部２２ａ〜２２ｃにおける加熱コイル２３の巻き付け方向については、図４に示すように隣り合う直交心部どうしで逆方向廻りに巻き付ける構成に限定されるものではなく、たとえば全ての直交心部２２ａ〜２２ｃで同じ方向廻りに巻き付ける構成としてもよい。この場合には、図６に示すように、各直交心部２２ａ〜２２ｃに対応する磁力線通過領域Ａｍどうしの間の領域では、それぞれの渦電流Ｉが逆向きに重合して打ち消し合うことになり、その代わりに全ての磁力線通過領域Ａｍ全体を囲む外周にほとんどの渦電流Ｉが流れるようになる。
【００３７】
図１９に示す円柱形状の直交磁心（コア１１２）に加熱コイル１１３を巻き付けた構成の場合、磁力線Ｍが導電性発熱部材４を貫通して周囲の広い範囲へ拡散することになるため、後述するような磁力線収束磁心として設ける平行磁心は拡散した磁力線Ｍを回収する構成は特に有効となる。
【００３８】
なお、図７に示すように並列に配置した各直交心部２２ａ〜２２ｃの反対部２６に、直交連結して被加熱表面４ａに対しては平行な配置となる平行心部（平行磁心）２７を一体に設けてコア２８全体をＥ字形状に形成してもよく、隣り合う直交心部どうしで逆方向廻りに加熱コイル２３を巻き付けた場合には各磁路が完全なループ形状となるためより高い磁力線漏出抑制効果が得られる。このようなＥ字形状のコア２８を用いた場合で、図７に示すように被加熱表面４ａに対する平行方向の外側の直交心部すなわち両端位置の直交心部２２ａ，２２ｃよりも、内側の直交心部すなわち中央位置の直交心部２２ｂの方に加熱コイル２３をより多く巻き付けることにより、並置する２つのループ形状の磁路にそれぞれ通過させる磁力線Ｍの本数のバランスを取ることができ、より高い磁力線漏出抑制効果を得ることができるようになる。また図示しないが、中央位置の直交心部２２ｂにのみ加熱コイル２３を巻き付けるようにした場合には１つの加熱コイル２３に対してその周囲に２つのループ形状の磁路を設ける配置となるため、さらに高い磁力線漏出抑制効果が得られるようになる。
【００３９】
また以上の構成において、直交心部を４つ以上直列に配置し、全体的にＥ字形状を複数連設したコアの構成としてもよく、その場合でも各直交心部に対して上記のような加熱コイルの巻き数のバリエーションが適用できる。
【００４０】
逆に直交心部を設置する本数は２本としてもよく、さらに図８に示すように並列に配置させた２本の直交心部２２ａ，２２ｂの反対部２６に直交して連結する平行心部（平行磁心）２７を一体に設けてコア２９全体をＵ字形状に形成してもよい。その場合でも２本の直交心部２２ａ，２２ｂに互いに逆廻り方向に加熱コイル２３を巻き付けることにより、直交心部２２ａ，２２ｂと導電性発熱部材４とで１つのループ形状の磁路を形成させることができる。
【００４１】
次に第２の実施の形態の第１変形例であり、被加熱表面４ａの形状が正方形である場合の変形例について説明する。この場合の１例としては、図９に示すように２行２列で４本の直交心部３２ａ〜３２ｄを配置させ、またそれらの反対部３６に共通の平行平板部（平行磁心）３７を設けてコア３２を構成してもよい。このように直交心部３２ａ〜３２ｄを被加熱表面４ａに対する平行方向の任意の配置で設けることにより、被加熱表面４ａ上の加熱領域の形状を任意に設定することが可能である。また係わる磁気ヘッドは、個々のコア（磁心）の磁極を組み換えて全体の加熱加工の形状を自在に変更することが可能である。
【００４２】
図１０は上記のコア３２のうち隣り合う直交心部どうしで逆方向廻りに加熱コイルを巻き付けた場合の正方形の被加熱表面４ａに流れる渦電流Ｉのある瞬間における経路を示した図である。図１０に示すように、各磁力線通過領域Ａｍどうしの間には前述と同様に渦電流Ｉが重合した大電流Ｉ_Ｌによる高加熱部が発生することになり、これらが均等な配置となっているため被加熱表面４ａ全体の均一加熱を図ることができる。また正方形の被加熱表面４ａに対し、３行３列や４行４列などの配置としてより多くの直交心部を配置することでさらに均一かつ高い効率で加熱することも可能である。また隣り合う２つの直交心部と被加熱表面４ａと平行平板部３７とでループ形状の磁路を形成し、磁力線漏出抑制効果を得ることもできる。
【００４３】
図１１は上記のコア３２の全ての直交心部３２ａ〜３２ｄで同じ方向廻りに加熱コイルを巻き付けた場合の渦電流Ｉのある瞬間における経路を示した図である。図１１に示すように、各磁力線通過領域Ａｍどうしの間の領域ではそれぞれの渦電流Ｉが逆向きに重合して打ち消し合うことになり、その結果全ての磁力線通過領域Ａｍ全体を囲む外周にほとんどの渦電流Ｉが流れるようになる。導電性発熱部材４の縁部分を加熱させるのに適している。
【００４４】
また第２の実施の形態の第２変形例であり、被加熱表面４ａの形状が四角形などの多角形である場合に特に好適な変形例について説明する。図１７に示す比較例のように四角形の被加熱表面４ａに対して平面渦巻き状に形成された加熱コイル１０３のみにより誘導加熱される場合には、図１８に示すように四角形の四隅の角部分４ｂが十分に誘導加熱されずに加熱状態の不均一による温度ムラが生じてしまう。また特にコアを有しない場合に磁力線通過領域Ａｍの中心に生じる加熱不足もまた温度ムラの要因となっている。
【００４５】
これに対して図１２に示す本変形例のコア３８では、平面渦巻き状の加熱コイル１０３の中心位置と四角形被加熱表面４ａの各角部分位置にそれぞれ円柱形状の直交心部３８ａ，３８ｂを配置し、さらに中心位置の直交心部３８ａの反対部から他の直交心部３８ｂの反対部へそれぞれ掛け渡すように４つの円柱形状の平行心部３８ｃを配置した構成となっている。
【００４６】
これによれば、平面渦巻き状の加熱コイル１０３からその中心位置をも含めた円形の領域Ａｍで磁力線Ｍが被加熱表面４ａを通過し、そののちに各角部分位置に向かって分散してそれぞれの直交心部３８ｂに収束し、各平行心部３８ｃを介して中心位置の直交心部３８ａに収束する。そのため各角部分位置の領域Ａｍ_２を含む周囲にも磁力線Ｍの通過により渦電流Ｉが流れて誘導加熱されることになり、その結果、四角形被加熱表面４ａの全体における温度ムラが緩和されることになる。さらに各角部分の直交心部３８ｂと中心位置の直交心部３８ａとの間にはそれぞれループ形状となる磁路が形成されるため、高い磁力線漏出抑制効果も得ることができる。
【００４７】
なお、図示しないが、被加熱表面４ａの形状が四角形以外の多角形形状であっても各角部分位置にそれぞれ直交心部３８ｂを配置して中心位置の直交心部３８ａとの間に平行心部３８ｃを掛け渡すよう配置することで図１２に示す変形例と同様の効果を得ることができる。また各角部分位置の直交心部３８ｂの正確な配置については、各角部分の頂点位置はもちろん、それよりも被加熱表面４ａの内側や外側にも多少の許容度を持ってずれた配置であってもよい。
【００４８】
（実施の形態３）
図１３（Ａ）は本発明の第３の実施の形態である電磁誘導加熱装置の電磁ヘッド部とそれにより誘導加熱されている状態の導電性発熱部材の斜視図、図１３（Ｂ）は第３の実施の形態の変形例である電磁誘導加熱装置の電磁ヘッド部とそれにより誘導加熱されている状態の導電性発熱部材の斜視図である。本実施の形態およびその変形例の電磁誘導加熱装置において、図１３（Ａ）、図１３（Ｂ）に示すように電磁ヘッド部４１，５１はＴ字形状に形成されたコア４２，５２と、それに巻き付けられた加熱コイル４３，５３とを有している。
【００４９】
コア４２，５２は、被加熱表面４ａに対して直交する配置の直交磁心である直交平板部４４，５４と、この直交平板部４４，５４の反対部４６，５６に直交して被加熱表面４ａに対して平行となる配置の磁力線収束磁心である平行平板部４７，５７（平行磁心）とを一体に備えてＴ字形状となっている。被加熱表面４ａは長方形の形状となっており、平行平板部４７，５７は被加熱表面４ａの形状にほぼ相似する長方形の平板形状に形成されている。直交平板部４４，５４の対向部４５，５５はその両側に傾斜面４８，５８を有して尖った楔形状に形成されている。
【００５０】
図１３（Ａ）に示す直交平板部４４は被加熱表面４ａに直交する方向に長く形成されており、加熱コイル４３はこの対向部４５の傾斜面４８も含めた直交平板部４４の外周に長手方向にずらして巻き付けられている。図１３（Ｂ）に示す直交平板部５４は被加熱表面４ａに直交する方向に短く形成されており、加熱コイル５３はこの対向部５５の傾斜面５８の外周で同じ長手方向位置に重なるよう平面渦巻き状に巻き付けられている。図示してはいないが、通常この電磁ヘッド部４１，５１は、樹脂等のような非導電体かつ非磁性体の材質で形成したケース内に収容されて用いられることになる。
【００５１】
上記構成によれば、平行平板部４７，５７が磁力線Ｍを捕捉することによりその通過経路を整形することができるため、被加熱表面４ａの形状に対応する適切な経路で磁力線Ｍを通過させて被加熱表面４ａに対する加熱の均一化を図ることができる。また図１３（Ａ）に示す電磁ヘッド部４１によれば、非加熱表面４ａに対して細長形状の領域で加熱することができ、図１３（Ｂ）に示す電磁ヘッド部５１によれば、長形大面積の領域で加熱することができる。
【００５２】
また、本実施の形態の電磁ヘッド部４１，５１は、Ｔ字形状のコア４２，５２の図中下方側の対向部４５，５５がその両側に傾斜面４８，５８を有して尖った楔形状となっていることにより、以下に説明するように被加熱表面４ａに通過させる磁力線Ｍの密度を集中させることができる。
【００５３】
図１４（Ａ）は、比較例として対向部５が被加熱表面４ａに対して平行な平端面の形状に形成されている場合で、加熱操作の定常状態時にそこから放出される磁力線Ｍの様子を示している。平端面の中央箇所において渦電流発生のメカニズムにより、被加熱表面４ａ上の対応する範囲Ｙではほとんど誘導加熱が行われずに加熱状態が不均一となって大きく温度ムラができてしまう。
【００５４】
これに対して図１４（Ｂ）に示すように対向部４５が両側に傾斜面４８を有して尖った楔形状に形成されている場合には、磁力線Ｍは中央の尖端部から集中して放出されるようになるため、中央の非加熱範囲Ｙをなくすことができるとともに、両側方向に拡散していた分の磁力線Ｍも合わせて集中的に被加熱表面４ａへ通過させることが可能となる。したがって導電性発熱部材４に対する誘導加熱をより効果的に行うことができる。
【００５５】
またこの対向部４５の傾斜面４８は側面側の２方向だけでなく、図１５に示すようにその外周全体に渡って形成されてもよく、それによりたとえば対向部４５を全体的に角錐形状（または円錐形状）に形成することもできる。この場合磁力線Ｍが尖端点の１点に向かって集中するように放出されるため、最も局所的かつ効率的に誘導加熱を行うことができるようになる。
【００５６】
また以上の平行平板部４７，５７を設ける構成では、平行平板部４７，５７に対して直交平板部４４，５４が一体となって形成されているものに限られず、部材間で磁力線Ｍが通過可能であればそれぞれ別体で形成したものを組み合わせてＴ字形状とする構成としてもよい。
【００５７】
さらに、コア４２と同じ強磁性材料（フェライトなど）で構成され、図１６中に示すようにＴ字形状のコア４２の周囲に配置されるフレーム組立体４９をヘッド収容部に組み込んでもよい。これにより、フレーム組立体４９も磁路を形成する磁力線捕捉部材として機能し、コア４２の周囲の磁力線Ｍを捕捉してその通過経路を整形し、また磁力線Ｍが外部へ漏出するのをより効果的に抑制することができる。磁力線捕捉部材は強磁性材料を材質としていれば図１６に示すような形状のフレーム組立体４９に限られるものではなく、たとえばネット状の形態とするなど多様な構成が考えられる。
【００５８】
なお、コア４２，５２の平行平板部４７，５７および磁力線捕捉部材の形状と被加熱表面４ａの形状の間の相似関係については、縦方向と横方向の縮尺の差や、小さい切り欠き形状や突出形状といった局所的違いについては多少の許容を持たせることはもちろん可能である。
【００５９】
本発明は種々の誘導加熱に応用される。たとえば利用方法の１つとして、特開平８−７３８１８号公報などに記載されているオールオーバー工法の改良磁気ヘッドとして用いることができる。導電性発熱部材としての金属薄板の両面に熱可塑性接着剤を塗布し、２つの非導電性の板材の間に挟み込ませた状態で一方の板材の反対面から本発明の加熱装置により金属薄板を誘導加熱することで２つの板材を相互に接着させるといった接着剤の溶融装置としての利用方法が考えられる。さらに、この接着剤の溶融装置によれば、部材相互の接着箇所を再度加熱して、固化した接着剤を再び溶融させ、２つの部材を相互に分離することもできる。接着剤が炭化するまで加熱し続けた場合には、接着剤を部材から容易に除去することができるので、分離した部材を再利用することができる。
【００６０】
【発明の効果】
本発明によれば、磁心の対向部の断面形状が被加熱表面の形状と適合することにより、渦電流の経路を被加熱表面の形状とほぼ相似させることができ、熱伝導との融合効果により誘導加熱の均一化を図ることができる。
【００６１】
本発明によれば、被加熱表面の形状に合わせて渦電流の発生領域を適切に設定できる。特に被加熱表面の形状に合わせて複数の直交磁心を配置することにより、被加熱表面全体に偏りなく渦電流を流して被加熱表面全体の均一加熱を図ることができる。さらに異なる直交磁心どうしで逆方向に磁力線を発生させることにより、渦電流が重合した大電流加熱部を発生させて加熱形状を変形させることができる。またループ形状の磁路を形成して高い磁力線漏出抑制効果も得られる。
【００６２】
本発明によれば、磁力線収束磁心が磁力線を収束することによりその通過経路を被加熱表面の形状に対応した適切な経路に整形できるため、渦電流の経路も偏りをなくして加熱の均一化を図ることができる。また磁力線が広い範囲へ拡散するのを抑えて加熱効率を向上できるとともに、操作者側へ向かう漏出を抑制できる。
【図面の簡単な説明】
【図１】第１の実施の形態による電磁誘導加熱装置が備える電磁ヘッド部とそれにより誘導加熱されている状態の導電性発熱部材の斜視図である。
【図２】電磁誘導加熱装置の電気回路を示すブロック図である。
【図３】導電性発熱部材に流れる渦電流の経路を図１における矢視Ｘから見た図である。
【図４】第２の実施の形態である電磁誘導加熱装置の電磁ヘッド部とそれにより誘導加熱されている状態の導電性発熱部材の斜視図である。
【図５】図４に示す電磁ヘッド部により導電性発熱部材に流れる渦電流のある瞬間における経路を示した図である。
【図６】図４に示すコアのうち全ての直交心部で同じ方向廻りに加熱コイルを巻き付けた場合の導電性発熱部材に流れる渦電流のある瞬間における経路を示した図である。
【図７】Ｅ字形状に形成されたコアにおいて、両端位置の直交心部よりも中央位置の直交心部の方に加熱コイルをより多く巻き付けた場合の変形例の斜視図である。
【図８】Ｕ字形状に形成されたコアおよび加熱コイルを備えた電磁ヘッド部の変形例の斜視図である。
【図９】直交心部を２行２列で４本配置させ、それらの反対部に共通の平行平板部を設ける構成のコアの斜視図である。
【図１０】図９に示すコアのうち隣り合う直交心部どうしで逆方向廻りに加熱コイルを巻き付けた場合の導電性発熱部材に流れる渦電流のある瞬間における経路を示した図である。
【図１１】図９に示すコアのうち全ての直交心部で同じ方向廻りに加熱コイルを巻き付けた場合の導電性発熱部材に流れる渦電流のある瞬間における経路を示した図である。
【図１２】平面渦巻き状の加熱コイルの中心位置と四角形被加熱表面の各角部分位置に直交心部を配置し、さらに４つの平行心部を連結した構成のコアの斜視図である。
【図１３】（Ａ）は第３の実施の形態である電磁誘導加熱装置の電磁ヘッド部とそれにより誘導加熱されている状態の導電性発熱部材の斜視図、（Ｂ）は第３の実施の形態の変形例である電磁誘導加熱装置の電磁ヘッド部とそれにより誘導加熱されている状態の導電性発熱部材の斜視図である。
【図１４】（Ａ）は、被加熱表面に対して平行な平端面の形状に形成されている対向部から磁力線が定常状態で放出されている様子を示す断面図であり、（Ｂ）は尖った楔形状に形成されている対向部から磁力線が放出されている様子を示す断面図である。
【図１５】角錐形状に形成された対向部のみを示した斜視図である。
【図１６】Ｔ字形状コアの周囲に配置されるフレーム組立体を示す斜視図である。
【図１７】平面渦巻き状に形成された加熱コイルのみで構成する電磁ヘッド部と、それにより誘導加熱されている状態の導電性発熱部材の斜視図である。
【図１８】図１７に示す電磁ヘッド部により導電性発熱部材に流れる渦電流の経路を示した図である。
【図１９】円柱形状の磁心に加熱コイルを巻き付けた電磁ヘッド部と、それにより誘導加熱されている状態の導電性発熱部材の斜視図である。
【符号の説明】
１第１実施形態の電磁ヘッド部
２コア（直交磁心）
３加熱コイル
４導電性発熱部材
４ａ被加熱表面
４ｂ不足加熱の箇所
４ｃ過熱する縁部
５対向部
６反対部
７電磁誘導加熱装置
８操作スイッチ
９ヘッド収容部
１０電源ユニット
１１高周波発生器
１２加熱時間設定器
１３本体部（交流電流供給部）
１４給電リッツ線
１５ＡＣコード
１６交流電源
２１第２実施形態の電磁ヘッド部
２２コア
２２ａ〜２２ｃ直交心部（直交磁心）
２３加熱コイル
２５対向部
２６反対部
２７平行心部（平行磁心）
２８Ｅ字形状コア（直交磁心、平行磁心）
２９Ｕ字形状コア（直交磁心、平行磁心）
３２第２実施形態の第１変形例のコア
３２ａ〜３２ｄ直交心部（直交磁心）
３５対向部
３６反対部
３７平行平板部（平行磁心）
３８第２実施形態の第２変形例のコア
３８ａ中心位置直交心部（直交磁心）
３８ｂ角部分位置直交心部（直交磁心）
３８ｃ平行心部（平行磁心）
３９第２実施形態の第３変形例のコア
３９ａ平行平板部（平行磁心）
３９ｂ取り付けねじ孔
３９ｃ取り付けねじ
３９ｄ着脱型直交心部（直交磁心）
４１，５１第３実施形態の電磁ヘッド部
４２，５２Ｔ字形状コア
４３，５３加熱コイル
４４，５４直交平板部（直交磁心）
４５，５５対向部
４６，５６反対部
４７，５７平行平板部（磁力線収束磁心、平行磁心）
４８，５８傾斜面
４９フレーム組立体（磁力線捕捉部材）
１０３平面渦巻き状加熱コイル
Ｍ交番磁力線
Ａｍ、Ａｍ_２磁力線通過領域
Ｙ磁力線の無通過範囲
Ｉ渦電流
Ｉ_Ｌ重合大電流[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic induction heating device that performs induction heating on a conductive heat generating member.
[0002]
[Prior art]
As one of effective methods for heating a conductive object such as a metal, there is induction heating using electromagnetic induction. This is because when an electroconductive heating member is present in an alternating magnetic field, an electromotive force is generated in the object due to the electromagnetic induction action, whereby an induced current flows in the object and I ² The conductive heating member is heated to a predetermined temperature by utilizing the generation of Joule heat of R.
[0003]
Conventionally, as a configuration for performing induction heating on a conductive heating member having a flat surface to be heated, a coil formed in a spiral shape on the same plane is arranged in parallel and close to the surface to be heated. For example, there is a method in which a high-frequency current of about 30 kHz is supplied to cause induction heating by passing alternating lines of magnetic force on a surface to be heated (for example, see Patent Document 1).
[0004]
In another configuration, a coil is wound around the outer periphery of a magnetic core formed in a slender cylindrical shape with a magnetic material, and one end of the core is opposed to the surface to be heated and arranged substantially orthogonally. The alternating magnetic force lines pass in a direction substantially perpendicular to the surface to be heated from the end on the side, and induction heating is performed.
[0005]
[Patent Document 1]
JP-A-8-73818
[0006]
[Problems to be solved by the invention]
However, in both the configuration in which the coil is formed in a planar spiral shape and the configuration in which the coil is wound around a columnar magnetic core, the area through which the lines of magnetic force pass is limited to a circular shape.
[0007]
If the area through which the lines of magnetic force do not match the shape of the surface to be heated, there are places where the lines of magnetic force do not pass enough and the eddy currents are so small that induction heating is insufficient, or eddy currents are present at the edges of the heated surface. Is concentrated and excessively heated, and as a result, there is a problem that the heating state on the entire surface to be heated becomes non-uniform and the desired heating shape is impaired.
[0008]
An object of the present invention is to provide an electromagnetic induction heating apparatus that can appropriately set an eddy current generation region according to the shape of a surface to be heated and heat the surface to be heated to a desired shape.
[0009]
[Means for Solving the Problems]
The electromagnetic induction heating apparatus of the present invention is configured to inductively heat a conductive heating member by Joule heat of an eddy current generated by passing alternating magnetic force lines through the conductive heating member. A high-permeability orthogonal magnetic core having an opposed portion having a cross-sectional shape adapted to the shape of the surface to be heated opposite to the surface to be heated of the member, and an AC current supplied from an AC current supply unit wound around the outer periphery of the orthogonal core. The heating coil has a heating coil, and the alternating magnetic force lines generated around the heating coil are converted from the facing part of the orthogonal magnetic core to the conductive heating member in a direction almost orthogonal to the surface to be heated. And let it pass.
[0010]
The electromagnetic induction heating apparatus of the present invention is configured to inductively heat a conductive heating member by Joule heat of an eddy current generated by passing alternating magnetic force lines through the conductive heating member. A plurality of high-permeability orthogonal cores designed to face the surface to be heated of the member, that is, the arrangement, area, and strength of the heating section are adjusted, and an alternating current wound around at least one outer periphery of the plurality of orthogonal cores A heating coil to which an alternating current is supplied from the current supply unit, and passes alternating magnetic force lines generated around the heating coil from the orthogonal magnetic core to the conductive heating member in a direction substantially orthogonal to the surface to be heated. It is characterized by making it.
[0011]
The electromagnetic induction heating device of the present invention is characterized in that the plurality of orthogonal magnetic cores are arranged according to the shape of the surface to be heated.
[0012]
In the present invention, since the respective orthogonal magnetic cores can be arranged in accordance with the shape of the surface to be heated, an eddy current can flow evenly over the entire shape of the surface to be heated, and the entire surface to be heated can be uniformly heated.
[0013]
The electromagnetic induction heating apparatus according to the present invention is characterized in that the heating coil is wound around the same direction around a plurality of orthogonal magnetic cores.
[0014]
The electromagnetic induction heating apparatus according to the present invention is characterized in that the heating coil is wound around at least one of the plurality of orthogonal magnetic cores in a direction opposite to the other.
[0015]
The electromagnetic induction heating apparatus of the present invention is configured to inductively heat a conductive heating member by Joule heat of an eddy current generated by passing alternating magnetic force lines through the conductive heating member. A high magnetic permeability orthogonal core having an opposing portion facing the surface to be heated of the member, a magnetic flux converging core disposed on the opposite side of the opposing portion of the orthogonal magnetic core to converge the alternating magnetic flux, and wound around the outer periphery of the orthogonal magnetic core. And a heating coil to which an alternating current is supplied from an alternating current supply section, so that alternating magnetic force lines generated around the heating coil are conducted in a direction substantially orthogonal to a surface to be heated from a facing portion of the orthogonal magnetic core. After passing through the conductive heating member, the magnetic flux is converged on the orthogonal magnetic core via the magnetic field converging magnetic core.
[0016]
In the present invention, since the magnetic flux converging magnetic core converges the magnetic flux, the passing path can be shaped into a path corresponding to the shape of the surface to be heated. Can be planned.
[0017]
The electromagnetic induction heating apparatus according to the present invention is characterized in that the magnetic field line capturing member for capturing and passing the alternating magnetic field lines is arranged around the orthogonal magnetic core or the magnetic field converging magnetic core.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0019]
(Embodiment 1)
FIG. 1 is a perspective view of an electromagnetic head provided in an electromagnetic induction heating device according to a first embodiment of the present invention and a conductive heating member in a state of being induction-heated thereby, and FIG. FIG. 3 is a diagram showing a path of an eddy current flowing through the conductive heat generating member viewed from an arrow X in FIG. The electromagnetic induction heating apparatus according to the present embodiment has an electromagnetic head 1 that generates alternating magnetic lines of force M for performing induction heating as shown in FIG. 1, and the electromagnetic head 1 is a core having an orthogonal magnetic core. 2 and a heating coil 3 wound around the periphery thereof.
[0020]
The core 2 is made of a material having high magnetic permeability, such as ferrite, iron, or a compound that is a ferromagnetic material, and an opposing portion 5 that opposes a heated surface 4a of a conductive heating member 4 that is a heated object. It is formed in a rectangular parallelepiped shape having an opposite portion 6 on the opposite side. Although not shown, the electromagnetic head unit 1 is usually used by being housed in a case formed of a non-conductive and non-magnetic material such as resin.
[0021]
As shown in FIG. 2, the electromagnetic induction heating device 7 includes a head housing unit 9 including the electromagnetic head unit 1 and the operation switch 8, and a main body unit 13 including a power supply unit 10, a high-frequency generator 11, and a heating time setting unit 12 ( The head accommodating section 9 and the main body section 13 are connected via a power supply litz wire 14.
[0022]
The operation switch 8 is provided in the same case as the electromagnetic head unit 1 and constitutes a head storage unit 9 so that an operator can input an operation for starting operation. The power supply unit 10 is connected to an external AC power supply 16 via an AC cord 15 so that the supplied AC power is rectified into DC power and supplied to other circuits described below. The high-frequency generator 11 is connected to the heating coil 3 via a power supply litz wire 14, and is configured to generate a high-frequency alternating current of, for example, about 20 to 30 kHz and supply it to the heating coil 3. The heating time setting unit 12 sets the energization time to the heating coil 3 required for one heating operation, and the energization set after receiving the energization operation signal from the operation switch 8 via the power supply litz wire 14. The control signal is output to the high-frequency generator 11 only for the time. The high frequency generator 11 supplies an alternating current to the heating coil 3 while receiving the control signal, that is, for a set energizing time. The heating time setting device 12 can arbitrarily adjust the setting of the energizing time.
[0023]
The operation of the electromagnetic induction heating device 7 having the above configuration will be described. The operator moves the head accommodating portion 9 and arranges the core 2 so as to be orthogonal and close to the surface 4a to be heated as shown in FIG. Induction heating for the heating member 4 is started. An alternating current is supplied to the heating coil 3 for the current supply time set in the heating time setting unit 12, and an alternating magnetic field line M is generated around the heating coil 3 around the core 2 as shown in the drawing.
[0024]
The core 2 functions as a magnetic path for controlling the spatial distribution of the lines of magnetic force M, that is, a magnetic flux path for converging and passing the lines of magnetic force M inside, and the lines of magnetic force M from the facing surface of the facing portion 5 of the core 2 to the surface 4a to be heated. At right angles to each other. Therefore, by changing the cross-sectional shape of the facing surface of the facing portion 5, the magnetic field line passing region Am can be arbitrarily set.
[0025]
As shown in FIG. 3, when the alternating magnetic field lines M pass through the magnetic field line passing area Am, an eddy current I is generated around the magnetic field line passing area Am due to an electromagnetic induction effect. The flow of the eddy current I generates Joule heat, whereby the conductive heating member 4 is subjected to induction heating.
[0026]
FIG. 17 shows, as a comparative example, an electromagnetic head portion 101 composed of only a heating coil 103 formed in a planar spiral shape without a core, and a conductive heating member arranged in parallel with the heating portion and heated by induction heating. FIG. 18 is a diagram showing a path of an eddy current I flowing through the conductive heat generating member 4. In FIG. 17, the heated surface 4 a of the conductive heating member 4 is formed in a rectangular shape whose long side is sufficiently longer than the diameter of the heating coil 103 and whose short side is slightly longer than the diameter of the heating coil 103.
[0027]
In the case of this configuration, the heating coil 103 needs to be wound around the circumference in order to obtain a sufficient number of lines of magnetic force M. Therefore, the region Am where the heating coil 103 passes the lines of magnetic force M to the surface 4a to be heated is However, as shown in the drawing, it is inevitably formed into a substantially circular shape requiring a large area. However, the actual surface 4a to be heated is often a polygonal shape other than a circle, that is, the shape of the surface 4a to be heated and the shape of the magnetic field line passing area Am often differ greatly.
[0028]
As shown in FIG. 18, when the magnetic field passing area Am does not match the shape of the surface to be heated 4a, there is a portion 4b where the eddy current I does not locally flow and is not sufficiently induction-heated. The eddy current I concentrates and heats excessively on the edge portion 4c and the like close to Am, and as a result, there is a problem that the heating state becomes non-uniform and large temperature unevenness occurs. Further, in particular, in the case of the electromagnetic head portion 101 including only the heating coil 103 formed in a plane spiral without a core as shown in FIG. 17, the magnetic field lines M pass locally at the center position of the plane spiral. As a result, the magnetic flux passing area Am becomes an annular shape with a hole at the center as shown in FIG. 18, which causes a non-uniform heating state.
[0029]
On the other hand, in the case of the electromagnetic head portion 1 of the present embodiment shown in FIG. 1, since the cross-sectional shape of the facing portion 5 of the core 2 matches the shape of the surface 4a to be heated, as shown in FIG. The eddy current I can flow evenly over the entire shape of the surface 4a to be heated.
[0030]
(Embodiment 2)
FIG. 4 is a perspective view of an electromagnetic head portion of an electromagnetic induction heating device according to a second embodiment of the present invention and a conductive heating member in a state where it is induction-heated by the electromagnetic head portion. FIG. FIG. 3 is a diagram showing a path at a certain moment of an eddy current I flowing through a conductive heating member 4 by an electromagnetic head unit 21. In the electromagnetic induction heating apparatus according to the present embodiment, as shown in FIG. 4, an electromagnetic head 21 includes a core 22 including three orthogonal cores (orthogonal magnetic cores) 22 a to 22 c arranged in parallel with each other, and And a heating coil 23 wound around the outer periphery of the heating coil 23.
[0031]
Each of the orthogonal core portions 22a to 22c is formed in a rectangular parallelepiped shape having an opposing portion 25 opposing the surface to be heated 4a and an opposing portion 26 on the opposite side. They are arranged so as to provide a uniform interval according to the shape of 4a. The intervals between the magnetic flux passing areas Am corresponding to the respective orthogonal core portions 22a to 22c and the respective edges of the surface 4a to be heated are not only equal as shown in FIG. In order to avoid concentration of I, an arrangement may be made in which a slightly larger interval is provided. In this manner, the orthogonal core portions 22a to 22c are in a state of being arranged in conformity with the shape of the surface 4a to be heated. Although each of the orthogonal core portions 22a to 22c shown in the drawing has a rectangular parallelepiped shape, it may have a cylindrical shape or another polygonal prism shape.
[0032]
The heating coil 23 is wound the same number of times in the same counterclockwise direction with respect to the orthogonal core portions 22a and 22c at both ends in the figure, and in the opposite clockwise direction around the central orthogonal core portion 22b. The orthogonal core portions 22a to 22c and the heating coil 23 are housed in a case (not shown) so that the mutual positional relationship is maintained.
[0033]
According to the above configuration, by arranging the orthogonal core portions 22a to 22c in conformity with the shape of the surface 4a to be heated, the eddy current I can flow evenly over the entire shape of the surface 4a to be heated. The same effect as that of the first embodiment described above can be obtained. Further, in the present embodiment, since the magnetic field lines M pass in the opposite directions between the adjacent orthogonal core portions, as described below, effective induction heating is performed on the heating region on the surface 4a to be heated. It can be performed.
[0034]
As a comparative example, when the surface 4a to be heated has a long shape like a rectangle and the facing portion 5 of the core 2 also has a long shape similar to the first embodiment shown in FIG. In this case, the eddy current in the longitudinal direction is made uniform and the temperature unevenness is reduced.
[0035]
5 and 6 show a method of changing a heating shape by a combination of magnetic poles of a core. According to the electromagnetic head portion 21 of the present embodiment, as shown in FIG. 4, the magnetic force line M always passes through the central orthogonal core portion 22b in the direction opposite to the other two orthogonal core portions 22a and 22c. The three orthogonal core portions 22a to 22c and the conductive heat generating member 4 form two substantially loop-shaped magnetic paths in parallel, so that the effect of suppressing leakage of the magnetic field lines M to the outside is improved. Become. Therefore, the magnetic field lines M can be prevented from diffusing into a wide range, and the magnetic field lines M can be concentratedly passed through the surface 4a to be heated, thereby improving the heating efficiency. I can do it.
[0036]
Note that the winding direction of the heating coil 23 in each of the orthogonal core portions 22a to 22c is not limited to a configuration in which adjacent orthogonal core portions are wound around opposite directions as shown in FIG. The parts 22a to 22c may be wound around the same direction. In this case, as shown in FIG. 6, in the region between the magnetic flux passing regions Am corresponding to the orthogonal core portions 22a to 22c, the eddy currents I overlap in the opposite directions and cancel each other. Instead, most of the eddy current I flows on the outer periphery surrounding the entire magnetic field line passing region Am.
[0037]
In the case of the configuration in which the heating coil 113 is wound around the cylindrical orthogonal magnetic core (core 112) shown in FIG. 19, the lines of magnetic force M penetrate the conductive heat generating member 4 and diffuse to a wide area around the same. The configuration in which the parallel magnetic core provided as such a magnetic flux converging magnetic core collects the diffused magnetic flux M is particularly effective.
[0038]
As shown in FIG. 7, a parallel core portion (parallel magnetic core) 27 which is orthogonally connected to the opposite portion 26 of each of the orthogonal core portions 22a to 22c arranged in parallel so as to be arranged parallel to the surface 4a to be heated. May be formed integrally to form the entire core 28 into an E-shape. When the heating coil 23 is wound around the adjacent orthogonal cores in the opposite direction, each magnetic path has a complete loop shape. A higher magnetic line leakage suppression effect can be obtained. In the case where such an E-shaped core 28 is used, as shown in FIG. 7, the outer orthogonal cores in the parallel direction to the surface 4a to be heated, that is, the inner orthogonal cores 22a and 22c at the both end positions are orthogonal. By winding the heating coil 23 more around the core portion, that is, the orthogonal core portion 22b at the center position, the number of lines of magnetic force M passing through the two loop-shaped magnetic paths juxtaposed can be balanced, so that the higher The effect of suppressing magnetic field line leakage can be obtained. Although not shown, when the heating coil 23 is wound only around the orthogonal core portion 22b at the center position, the arrangement is such that two loop-shaped magnetic paths are provided around one heating coil 23, It is possible to obtain a higher magnetic line of force leakage suppression effect.
[0039]
Further, in the above configuration, four or more orthogonal cores may be arranged in series, and a core configuration in which a plurality of E-shapes are provided in a row as a whole may be adopted. Variations in the number of turns of the heating coil can be applied.
[0040]
Conversely, the number of orthogonal cores may be two, and furthermore, as shown in FIG. 8, a parallel core orthogonally connected to the opposite part 26 of the two orthogonal cores 22a and 22b arranged in parallel. (Parallel magnetic core) 27 may be provided integrally, and the entire core 29 may be formed in a U-shape. Even in such a case, the heating coil 23 is wound around the two orthogonal cores 22a and 22b in the opposite directions to each other, so that the orthogonal cores 22a and 22b and the conductive heating member 4 form one loop-shaped magnetic path. be able to.
[0041]
Next, a first modification of the second embodiment, in which the shape of the surface 4a to be heated is a square, will be described. As an example in this case, as shown in FIG. 9, four orthogonal core portions 32a to 32d are arranged in two rows and two columns, and a common parallel plate portion (parallel magnetic core) 37 is provided in the opposite portion 36 thereof. The core 32 may be provided. By providing the orthogonal cores 32a to 32d in an arbitrary arrangement in the direction parallel to the surface 4a to be heated, the shape of the heating area on the surface 4a to be heated can be arbitrarily set. In the related magnetic head, it is possible to freely change the shape of the entire heating process by changing the magnetic poles of the individual cores (magnetic cores).
[0042]
FIG. 10 is a diagram showing a path at a certain moment of the eddy current I flowing on the square heated surface 4a when the heating coil is wound around the adjacent orthogonal core portions of the core 32 in opposite directions. As shown in FIG. 10, a large current I in which the eddy current I overlaps between the respective magnetic flux passing areas Am in the same manner as described above. _L , High heating portions are generated, and since these are arranged uniformly, uniform heating of the entire heated surface 4a can be achieved. Further, by arranging a larger number of orthogonal cores in a three-row, three-column or four-row, four-column arrangement on the square heated surface 4a, it is possible to perform heating evenly and with high efficiency. Further, a loop-shaped magnetic path is formed by two adjacent orthogonal core portions, the surface to be heated 4a, and the parallel flat plate portion 37, so that the effect of suppressing leakage of lines of magnetic force can be obtained.
[0043]
FIG. 11 is a diagram showing a path at a certain moment of the eddy current I when the heating coil is wound around the same direction in all the orthogonal core portions 32a to 32d of the core 32. As shown in FIG. 11, in the region between the respective magnetic flux passing areas Am, the respective eddy currents I overlap in the opposite direction and cancel each other out, and as a result, almost all of the outer circumference surrounding the entire magnetic flux passing area Am is formed. Eddy current I flows. It is suitable for heating the edge portion of the conductive heat generating member 4.
[0044]
A description will be given of a second modification of the second embodiment, which is particularly preferable when the shape of the surface 4a to be heated is a polygon such as a quadrangle. In the case where induction heating is performed only on the heating coil 103 formed in a flat spiral shape with respect to the square heated surface 4a as in the comparative example shown in FIG. 17, as shown in FIG. 4b is not sufficiently induction-heated, resulting in temperature unevenness due to uneven heating. Insufficient heating at the center of the magnetic flux passing area Am especially when the core is not provided also causes temperature unevenness.
[0045]
On the other hand, in the core 38 of this modified example shown in FIG. 12, cylindrical orthogonal cores 38a and 38b are respectively arranged at the center position of the heating coil 103 having a planar spiral shape and at each corner of the square heated surface 4a. Further, four cylindrical parallel cores 38c are arranged so as to extend from the opposite part of the orthogonal core 38a at the center position to the opposite part of the other orthogonal core 38b.
[0046]
According to this, the lines of magnetic force M pass through the surface to be heated 4a in the circular region Am including the center position from the heating coil 103 having a planar spiral shape, and thereafter are dispersed toward the respective corner portion positions. And converges on the orthogonal core 38a at the central position via the parallel cores 38c. Therefore, the region Am at each corner position ₂ As a result, the eddy currents I flow through the surroundings including the magnetic field lines M, so that induction heating is performed. As a result, the unevenness in temperature of the entire surface 4a to be heated is reduced. Further, a loop-shaped magnetic path is formed between the orthogonal core 38b at each corner and the orthogonal core 38a at the center, so that a high line of magnetic force leakage suppression effect can be obtained.
[0047]
Although not shown, even if the shape of the surface 4a to be heated is a polygonal shape other than a quadrangle, the orthogonal cores 38b are arranged at the respective corners, and the parallel cores 38b are arranged between the central cores and the orthogonal cores 38a. The same effect as that of the modification shown in FIG. 12 can be obtained by arranging the portion 38c so as to span it. Regarding the exact arrangement of the orthogonal cores 38b at the positions of the corners, not only the positions of the vertices of the corners but also the inside and outside of the surface 4a to be heated are shifted with some tolerance. There may be.
[0048]
(Embodiment 3)
FIG. 13A is a perspective view of an electromagnetic head portion of an electromagnetic induction heating device according to a third embodiment of the present invention and a conductive heating member in a state where it is induction-heated by the electromagnetic head portion. FIG. It is a perspective view of the electromagnetic head part of the electromagnetic induction heating apparatus which is a modification of 3rd Embodiment, and the conductive heating member in the state where it was induction-heated by it. In the electromagnetic induction heating device according to the present embodiment and its modified example, as shown in FIGS. 13A and 13B, the electromagnetic head portions 41 and 51 include T-shaped cores 42 and 52, It has heating coils 43 and 53 wound therearound.
[0049]
The cores 42, 52 are orthogonal plate portions 44, 54 which are orthogonal magnetic cores arranged orthogonally to the surface 4a to be heated, and portions 46, 56 opposite to the plate portions 44, 54 orthogonal to the surface 4a. And parallel plate portions 47 and 57 (parallel magnetic cores), which are magnetic flux converging magnetic cores arranged in parallel with respect to. The surface 4a to be heated has a rectangular shape, and the parallel plate portions 47 and 57 are formed in a rectangular plate shape substantially similar to the shape of the surface 4a to be heated. Opposing portions 45, 55 of the orthogonal flat plate portions 44, 54 have inclined surfaces 48, 58 on both sides thereof and are formed in a sharp wedge shape.
[0050]
The orthogonal flat plate portion 44 shown in FIG. 13A is formed to be long in a direction orthogonal to the surface to be heated 4 a, and the heating coil 43 extends longitudinally on the outer periphery of the orthogonal flat plate portion 44 including the inclined surface 48 of the facing portion 45. Wrongly wound in the direction. The orthogonal flat plate portion 54 shown in FIG. 13B is formed to be short in a direction orthogonal to the surface to be heated 4 a, and the heating coil 53 is formed so as to overlap the same longitudinal position on the outer periphery of the inclined surface 58 of the facing portion 55. It is wound in a spiral. Although not shown, the electromagnetic heads 41 and 51 are usually used by being housed in a case made of a non-conductive and non-magnetic material such as resin.
[0051]
According to the above configuration, since the parallel flat plate portions 47 and 57 can shape the passage path of the magnetic field lines M by capturing the magnetic field lines M, the magnetic field lines M can be passed along an appropriate path corresponding to the shape of the surface 4a to be heated. Heating of the heated surface 4a can be made uniform. Further, according to the electromagnetic head portion 41 shown in FIG. 13A, it is possible to heat the non-heated surface 4a in an elongated region, and according to the electromagnetic head portion 51 shown in FIG. It can be heated in a large area area.
[0052]
Further, the electromagnetic head portions 41, 51 of the present embodiment have sharp wedges in which opposed portions 45, 55 on the lower side of the T-shaped cores 42, 52 have inclined surfaces 48, 58 on both sides thereof. Due to the shape, the density of the lines of magnetic force M passing through the surface to be heated 4a can be concentrated, as described below.
[0053]
FIG. 14A shows, as a comparative example, a case where the opposing portion 5 is formed in the shape of a flat end surface parallel to the surface 4a to be heated, and the state of the magnetic force lines M emitted therefrom during a steady state of the heating operation. Is shown. Due to the mechanism of eddy current generation at the center of the flat end surface, induction heating is hardly performed in the corresponding range Y on the surface 4a to be heated, and the heating state becomes non-uniform, resulting in large temperature unevenness.
[0054]
On the other hand, when the facing portion 45 is formed in a sharp wedge shape with the inclined surfaces 48 on both sides as shown in FIG. 14B, the magnetic force lines M are concentrated from the central point. Since the radiation is released, the central non-heating range Y can be eliminated, and the lines of magnetic force M that have been diffused in both side directions can be intensively passed to the heated surface 4a together. . Therefore, induction heating of the conductive heating member 4 can be performed more effectively.
[0055]
Further, the inclined surface 48 of the facing portion 45 may be formed not only in two directions on the side surface side but also over the entire outer periphery as shown in FIG. Or conical shape). In this case, since the magnetic force lines M are emitted so as to concentrate toward one point of the point, the induction heating can be performed most locally and efficiently.
[0056]
Further, in the configuration in which the parallel plate portions 47 and 57 are provided, the orthogonal plate portions 44 and 54 are not limited to being formed integrally with the parallel plate portions 47 and 57, and the magnetic force lines M pass between the members. If possible, a configuration may be adopted in which a T-shaped configuration is formed by combining components formed separately.
[0057]
Further, a frame assembly 49 made of the same ferromagnetic material (ferrite or the like) as the core 42 and arranged around the T-shaped core 42 as shown in FIG. 16 may be incorporated in the head housing portion. Accordingly, the frame assembly 49 also functions as a magnetic field line capturing member that forms a magnetic path, captures the magnetic field lines M around the core 42, shapes the passage therethrough, and more effectively prevents the magnetic field lines M from leaking outside. Can be suppressed. The magnetic field line capturing member is not limited to the frame assembly 49 having a shape as shown in FIG. 16 as long as it is made of a ferromagnetic material, and various configurations such as a net-like shape are conceivable.
[0058]
The similarity between the shapes of the parallel plate portions 47 and 57 and the magnetic flux trapping members of the cores 42 and 52 and the shape of the surface 4a to be heated is described in terms of the difference between the scales in the vertical and horizontal directions, the small notch shape, and the like. It is of course possible to allow some tolerance for local differences such as protruding shapes.
[0059]
The invention applies to various induction heatings. For example, as one of utilization methods, it can be used as an improved magnetic head of an all-over construction method described in Japanese Patent Application Laid-Open No. 8-73818. A thermoplastic adhesive is applied to both surfaces of a metal sheet as a conductive heating member, and the metal sheet is sandwiched between two non-conductive sheets by using the heating device of the present invention from the opposite side of one of the sheets. A method of using an adhesive as a melting device, such as bonding two plate materials to each other by induction heating, is considered. Further, according to the adhesive melting device, the bonding portion between the members can be heated again, the solidified adhesive can be melted again, and the two members can be separated from each other. When the heating is continued until the adhesive is carbonized, the adhesive can be easily removed from the member, and the separated member can be reused.
[0060]
【The invention's effect】
According to the present invention, since the cross-sectional shape of the opposed portion of the magnetic core matches the shape of the surface to be heated, the path of the eddy current can be made substantially similar to the shape of the surface to be heated, and the fusion effect with heat conduction can be obtained. The induction heating can be made uniform.
[0061]
According to the present invention, the eddy current generation region can be appropriately set according to the shape of the surface to be heated. In particular, by arranging a plurality of orthogonal magnetic cores according to the shape of the surface to be heated, an eddy current can flow evenly over the entire surface to be heated and uniform heating of the entire surface to be heated can be achieved. Further, by generating magnetic lines of force in opposite directions between different orthogonal magnetic cores, a large current heating portion in which eddy currents overlap can be generated to deform the heating shape. In addition, a loop-shaped magnetic path is formed, so that a high magnetic field line leakage suppressing effect can be obtained.
[0062]
According to the present invention, since the magnetic flux converging core converges the magnetic flux, the passing path can be shaped into an appropriate pathway corresponding to the shape of the surface to be heated. Can be planned. In addition, it is possible to improve the heating efficiency by suppressing the magnetic field lines from diffusing into a wide range, and to suppress leakage toward the operator.
[Brief description of the drawings]
FIG. 1 is a perspective view of an electromagnetic head provided in an electromagnetic induction heating device according to a first embodiment, and a conductive heating member in a state where induction heating is performed by the electromagnetic head.
FIG. 2 is a block diagram showing an electric circuit of the electromagnetic induction heating device.
FIG. 3 is a view of a path of an eddy current flowing through a conductive heat generating member viewed from an arrow X in FIG. 1;
FIG. 4 is a perspective view of an electromagnetic head of an electromagnetic induction heating device according to a second embodiment, and a conductive heating member in a state where it is induction-heated thereby.
5 is a diagram showing a path at an instant of an eddy current flowing through a conductive heating member by the electromagnetic head unit shown in FIG. 4;
6 is a diagram showing a path at a certain moment of an eddy current flowing through a conductive heating member when a heating coil is wound around the same direction in all orthogonal core portions of the core shown in FIG. 4;
FIG. 7 is a perspective view of a modified example in which a heating coil is wound more around the orthogonal core portion at the center position than the orthogonal core portions at both end positions in a core formed in an E-shape.
FIG. 8 is a perspective view of a modified example of an electromagnetic head unit including a U-shaped core and a heating coil.
FIG. 9 is a perspective view of a core having a configuration in which four orthogonal core portions are arranged in two rows and two columns, and a common parallel flat plate portion is provided at the opposite portion.
10 is a diagram showing a path at an instant of an eddy current flowing through a conductive heating member when a heating coil is wound around the orthogonal cores in the opposite direction in the core shown in FIG. 9;
11 is a diagram showing a path at a certain moment of an eddy current flowing through a conductive heating member when a heating coil is wound around the same direction in all orthogonal cores of the core shown in FIG. 9;
FIG. 12 is a perspective view of a core having a configuration in which an orthogonal core portion is arranged at the center position of a planar spiral heating coil and at each corner position of a quadrangular heated surface, and four parallel core portions are further connected.
FIG. 13A is a perspective view of an electromagnetic head of an electromagnetic induction heating device according to a third embodiment and a conductive heating member in a state of being induction-heated by the electromagnetic head, and FIG. 13B is a third embodiment. FIG. 15 is a perspective view of an electromagnetic head portion of an electromagnetic induction heating device according to a modification of the first embodiment, and a conductive heat generating member in a state where it is induction-heated by the electromagnetic head portion.
FIG. 14A is a cross-sectional view showing a state in which lines of magnetic force are emitted in a steady state from an opposing portion formed in the shape of a flat end surface parallel to the surface to be heated, and FIG. It is sectional drawing which shows a mode that the magnetic line of force is emitted from the opposing part formed in the shape of a sharp wedge.
FIG. 15 is a perspective view showing only an opposing portion formed in a pyramid shape.
FIG. 16 is a perspective view showing a frame assembly disposed around a T-shaped core.
FIG. 17 is a perspective view of an electromagnetic head portion composed of only a heating coil formed in a flat spiral shape, and a conductive heat generating member in a state where it is induction-heated by the electromagnetic head portion.
18 is a diagram showing a path of an eddy current flowing through the conductive heating member by the electromagnetic head unit shown in FIG.
FIG. 19 is a perspective view of an electromagnetic head in which a heating coil is wound around a columnar magnetic core, and a conductive heating member in a state where it is induction-heated thereby.
[Explanation of symbols]
1. Electromagnetic head section of first embodiment
2 cores (orthogonal core)
3 heating coil
4 Conductive heating members
4a Heated surface
4b Insufficient heating
4c Overheating edge
5 Opposite part
6 Opposite part
7 Electromagnetic induction heating device
8 Operation switch
9 Head storage
10 Power supply unit
11 High frequency generator
12 Heating time setting device
13 Main unit (AC current supply unit)
14. Power supply litz wire
15 AC code
16 AC power supply
21 Electromagnetic Head Unit of Second Embodiment
22 cores
22a-22c Orthogonal core (orthogonal magnetic core)
23 heating coil
25 Opposing part
26 Opposite part
27 Parallel core (parallel magnetic core)
28 E-shaped core (orthogonal core, parallel core)
29 U-shaped core (orthogonal core, parallel core)
32 Core of First Modification of Second Embodiment
32a to 32d Orthogonal core (orthogonal magnetic core)
35 Opposite part
36 Opposite part
37 Parallel plate (parallel magnetic core)
38 Core according to a second modification of the second embodiment
38a Center position orthogonal core (orthogonal magnetic core)
38b corner part position orthogonal core (orthogonal magnetic core)
38c Parallel core (parallel magnetic core)
39 Core of Third Modification of Second Embodiment
39a Parallel plate (parallel magnetic core)
39b Mounting screw hole
39c mounting screw
39d Removable orthogonal core (orthogonal magnetic core)
41, 51 Electromagnetic Head Unit of Third Embodiment
42,52 T-shaped core
43,53 heating coil
44,54 Orthogonal flat plate (orthogonal magnetic core)
45, 55 Opposing part
46,56 Opposite part
47,57 parallel flat plate (magnetic flux converging magnetic core, parallel magnetic core)
48,58 slope
49 Frame assembly (magnetic field line capturing member)
103 Planar spiral heating coil
M alternating magnetic field lines
Am, Am ₂ Magnetic field passage area
Y Non-passing range of magnetic field lines
I Eddy current
I _L Polymerization large current

Claims

An electromagnetic induction heating apparatus that generates an eddy current by passing alternating magnetic force lines through the conductive heating member, and inductively heats the conductive heating member with the Joule heat,
An alternating current supply unit for supplying an alternating current;
A high-permeability orthogonal core having an opposing portion having a cross-sectional shape conforming to the shape of the heated surface facing the heated surface of the conductive heating member;
A heating coil wound around the outer periphery of the orthogonal magnetic core and supplied with the AC current from the AC current supply unit,
An electromagnetic induction heating apparatus, wherein the alternating magnetic field lines generated around the heating coil are passed from the facing portion of the orthogonal magnetic core to the conductive heating member in a direction substantially orthogonal to the surface to be heated. .

An electromagnetic induction heating apparatus that generates an eddy current by passing alternating magnetic force lines through the conductive heating member, and inductively heats the conductive heating member with the Joule heat,
An alternating current supply unit for supplying an alternating current;
Designed to face the surface to be heated of the conductive heating member, that is, a plurality of high permeability orthogonal magnetic cores to adjust the arrangement and area and strength of the heating unit,
A heating coil wound around at least one outer periphery of the plurality of orthogonal magnetic cores and supplied with the AC current from the AC current supply unit;
The electromagnetic induction heating device, wherein the alternating magnetic field lines generated around the heating coil are passed through the conductive heat generating member according to a heating shape.

3. The electromagnetic induction heating apparatus according to claim 2, wherein the heating coil is wound around the plurality of orthogonal magnetic cores around the same direction.

3. The electromagnetic induction heating apparatus according to claim 2, wherein the heating coil is wound around at least one of the plurality of orthogonal magnetic cores in a direction opposite to the other.

An electromagnetic induction heating apparatus that generates an eddy current by passing alternating magnetic force lines through the conductive heating member, and inductively heats the conductive heating member with the Joule heat,
An alternating current supply unit for supplying an alternating current;
A high-permeability orthogonal core having an opposing portion opposing the surface to be heated of the conductive heating member,
A magnetic flux converging core arranged on the opposite side of the facing portion of the orthogonal magnetic core to converge the magnetic flux,
A heating coil wound around the outer periphery of the orthogonal magnetic core and supplied with the AC current from the AC current supply unit,
After passing the alternating magnetic force lines generated around the heating coil from the facing portion of the orthogonal magnetic core to the conductive heat generating member in a direction substantially orthogonal to the surface to be heated, the magnetic flux lines converge through the magnetic flux converging core. An electromagnetic induction heating device, wherein the magnetic flux is converged on the orthogonal magnetic core.

The electromagnetic induction heating device according to any one of claims 1 to 5, wherein a magnetic flux capturing member that captures and passes the alternating magnetic flux is disposed around the orthogonal magnetic core or the magnetic flux converging magnetic core. And an electromagnetic induction heating device.