JP2004335361A

JP2004335361A - High frequency heating arrangement and its control method

Info

Publication number: JP2004335361A
Application number: JP2003131804A
Authority: JP
Inventors: Makoto Mihara; 誠三原; Kazuho Sakamoto; 和穂坂本; Tomotaka Nobue; 等隆信江; Takeshi Takizaki; 健瀧▲崎▼
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2003-05-09
Filing date: 2003-05-09
Publication date: 2004-11-25

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high frequency heating arrangement capable of speedily treating even a thick object to be heated by heating by restraining uneven heating from being generated, and its control method. <P>SOLUTION: In this high frequency heating arrangement 100, a high frequency is supplied to a heating chamber 11 for storing an object M to be heated from a high frequency generating part, the high frequency generating part is provided with a first high frequency generating part 13 to generate a high frequency with a frequency of 2.45 GHz, and a second high frequency generating part 15 to generate a high frequency with a frequency of 5.8 GHz. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、被加熱物を収容する加熱室に高周波を供給して被加熱物を加熱する高周波加熱装置及びその制御方法に関し、特に５．８ＧＨｚの周波数成分を含む高周波を使用する技術に関する。
【０００２】
【従来の技術】
従前より、被加熱物を収容する加熱室に高周波を供給して被加熱物を加熱調理する高周波加熱装置が、食材の加熱調理用として広く利用されている。この種の高周波加熱装置は、周波数が２．４５ＧＨｚの高周波を発生するマグネトロンを搭載し、発生させた高周波を加熱室内に供給している。加熱室内では、高周波の供給により定在波が形成され、この発生する定在波の波長は約１２ｃｍとなり、その１／２の約６ｃｍの間隔で電界の強い実質的な加熱スポットが発生することになる。しかし、この加熱スポットの間隔は、加熱調理する食材の大きさと比較すると長いため、食材中に存在し得る加熱スポットの分布密度が低くなり、食材が部分的に加熱されて加熱ムラが生じやすくなる傾向があった
そこで、使用する高周波の周波数を２．４５ＧＨｚから５．８ＧＨｚに変更して前記加熱スポットの間隔を狭め、これにより加熱スポットの分布密度を高めて被加熱物の加熱ムラを低減させようとする技術が提案されている（例えば特許文献１参照）。
【０００３】
【特許文献１】
特開平３−２０３１９１号公報
【０００４】
【発明が解決しようとする課題】
しかしながら、５．８ＧＨｚの高周波は、２．４５ＧＨｚの高周波と比較すると加熱スポットの分布密度が高くなる反面、被加熱物への吸収深さが浅くなるため、被加熱物が厚肉である場合には、被加熱物の表面が主に加熱され、被加熱物の内部が加熱不足になるといった加熱ムラが生じやすくなる。
従って、加熱分布が密となる５．８ＧＨｚの高周波では、被加熱物が薄肉である場合は良好な均一加熱効果が期待できるが、厚肉の被加熱物に対しては深さ方向に加熱ムラが大きくなり、結局は均一加熱が困難になる。なお、厚肉の場合でも被加熱物の表面から熱伝導により内部が加熱されるが、内部に熱が伝わるまでには時間がかかり、高周波加熱の最大の利点である急速加熱効果が奏されないことになる。
【０００５】
本発明は、上記事情を考慮してなされたもので、加熱ムラの発生を抑制し、厚肉の被加熱物であっても迅速に均一加熱処理が可能な高周波加熱装置及びその制御方法を提供することを目的としている。
【０００６】
【課題を解決するための手段】
上記目的は下記構成により達成される。
（１）被加熱物を収容する加熱室に高周波発生部から高周波を供給し、被加熱物を加熱処理する高周波加熱装置であって、前記高周波発生部が、周波数が２．４５ＧＨｚの高周波を発生する第１高周波発生部と、周波数が５．８ＧＨｚの高周波を発生する第２高周波発生部とを備えた高周波加熱装置。
【０００７】
この高周波加熱装置によれば、加熱効果の高い周波数が２．４５ＧＨｚの高周波と、加熱分布が均一な周波数が５．８ＧＨｚの高周波との２種類の高周波を加熱室に供給することができ、加熱ムラの発生を抑制して、厚肉の被加熱物であっても迅速に均一加熱処理が可能となる。
【０００８】
（２）前記第１高周波発生部へ駆動電力を供給する第１インバータ回路と、前記第２高周波発生部へ駆動電力を供給する第２インバータ回路と、これらインバータ回路により前記第１高周波発生部と前記第２高周波発生部とを同時に又は交互に駆動する駆動制御部とを備えた（１）記載の高周波加熱装置。
【０００９】
この高周波加熱装置によれば、第１高周波発生部と第２高周波発生部への駆動電力をそれぞれ別個のインバータ回路で供給するので、各高周波発生部から同時に又は交互に高周波を出力させることができ、また、出力強度も可変にできるため、複雑な加熱パターンであっても簡単に制御が行える。
【００１０】
（３）前記第１高周波発生部及び第２高周波発生部へ駆動電力を供給する単一のインバータ回路と、前記第１高周波発生部と前記第２高周波発生部への給電を交互に切り替えて駆動する駆動制御部とを備えた（１）記載の高周波加熱装置。
【００１１】
この高周波加熱装置によれば、単一のインバータ回路により第１高周波発生部と第２高周波発生部への給電を制御できるため、駆動制御部の回路構成が簡略化され、設置に必要とするスペースが小さく済み、装置の小型軽量化に寄与することができる。
【００１２】
（４）前記加熱室の上面に設けられ高周波を前記加熱室内に導入する上側給電口と、前記加熱室の下面に設けられ高周波を前記加熱室内に導入する下側給電口とを備え、該上側給電口と下側給電口のそれぞれから前記第１高周波発生部又は前記第２高周波発生部からの高周波を個別に導入する（１）〜（３）のいずれか１項記載の高周波加熱装置。
【００１３】
この高周波加熱装置によれば、上側給電口と下側給電口とのそれぞれから第１高周波発生部又は第２高周波発生部からの高周波を個別に加熱室へ導入するので、高周波の加熱特性に応じた最適な位置から各高周波を照射可能になる。
【００１４】
（５）前記加熱室の空間を上下に分割する仕切板を設けた（４）記載の高周波加熱装置。
【００１５】
この高周波加熱装置によれば、加熱室の空間を上下に分割することにより、上側空間に一方の高周波を供給し、下側空間に他方の高周波を供給することができ、各高周波を個別の空間に供給して加熱することができる。
【００１６】
（６）前記仕切板が高周波発熱体を備え、高周波の照射により発熱する（５）記載の高周波加熱装置。
【００１７】
この高周波加熱装置によれば、仕切板の高周波発熱体が高周波の照射により発熱するので、この仕切板に載置された被加熱物を輻射熱や伝導熱により加熱して、被加熱物に焦げ目を付けることができる。また、加熱室を暖めて予熱効果を持たせることもできる。
【００１８】
（７）前記加熱室の上側給電口から前記第２高周波発生部からの高周波を前記加熱室内に導入する（４）〜（６）のいずれか１項記載の高周波加熱装置。
【００１９】
この高周波加熱装置によれば、第２高周波発生部からの５．８ＧＨｚの高周波が上側給電口から供給されるので、加熱室内の被加熱物を均一に加熱することができる。
【００２０】
（８）前記加熱室が、開口部を有する加熱室本体と、該開口部を開閉自在に覆う開閉扉とを有し、前記加熱室本体と前記開閉扉とが対向する部分の少なくとも一方に、電波洩れ防止用のチョークが形成され、該チョークが前記第１高周波発生部と前記第２高周波発生部からの各高周波を遮蔽するものである（１）〜（７）のいずれか１項記載の高周波加熱装置。
【００２１】
この高周波加熱装置によれば、小型のチョークでありながら、開閉扉が閉じられたときに、加熱室内部に供給される２種類の異なる周波数の高周波が洩れ出すことがない。
【００２２】
（９）被加熱物を収容する加熱室に高周波発生部から高周波を供給し、被加熱物を加熱処理する高周波加熱装置の制御方法であって、前記高周波発生部から、周波数が２．４５ＧＨｚの高周波と周波数が５．８ＧＨｚの高周波とを同時に又は交互に前記加熱室に供給する高周波加熱装置の制御方法。
【００２３】
この高周波加熱装置の制御方法によれば、周波数が２．４５ＧＨｚの高周波と周波数が５．８ＧＨｚの高周波とを同時に又は交互に前記加熱室に供給することにより、加熱効果の高い２．４５ＧＨｚの高周波と、均一加熱効果の高い５．８ＧＨｚの高周波とが選択的に供給可能となるので、被加熱物の形状や加熱目的に応じた適切な高周波を供給して効率の良い加熱処理を行うことができる。
【００２４】
（１０）前記各周波数のうち、いずれか一方の高周波を加熱初期に出力し、加熱開始から所定時間経過後又は所定温度到達後にいずれか他方の高周波の出力を開始する（９）記載の高周波加熱装置の制御方法。
【００２５】
この高周波加熱装置の制御方法によれば、加熱効果の高い周波数が２．４５ＧＨｚの高周波を加熱初期に供給し、被加熱物を一気に昇温させ、また、所定時間経過後或いは所定温度到達後に周波数が５．８ＧＨｚの高周波を供給することで、加熱温度の均一化を図り、被加熱物を温度分布の少ない均一加熱状態にすることができる。また、これとは逆に先に５．８ＧＨｚの高周波を供給して、２．４５ＧＨｚの高周波を後から供給する場合には、加熱後半に強く加熱する調理等に好適な加熱パターンとなる。
【００２６】
（１１）前記各周波数を同時に出力する場合に、各高周波の出力を、高周波出力のための駆動電力の合計が高周波加熱装置の定格電力を超えないように少なくともいずれか一方の出力を制限する（９）又は（１０）記載の高周波加熱装置の制御方法。
【００２７】
この高周波加熱装置の制御方法によれば、各高周波の出力が定格電力を超えるような場合には、いずれか一方の高周波の出力を制限して、高周波出力のための駆動電力の合計が高周波加熱装置の定格電力を超えないようにできる。
【００２８】
【発明の実施の形態】
以下、本発明に係る高周波加熱装置及びその制御方法の好適な実施の形態について、図面を参照して詳細に説明する。
図１は本発明に係る高周波加熱装置の概念的な構成図、図２は高周波加熱装置の高周波駆動部の構成図である。
【００２９】
図１に示すように、この高周波加熱装置１００は、被加熱物Ｍを収容する加熱室１１に高周波を供給して被加熱物Ｍを加熱処理するものであって、高周波発生部として、周波数が２．４５ＧＨｚの高周波を発生する第１高周波発生部１３と、周波数が５．８ＧＨｚの高周波を発生する第２高周波発生部１５を備えている。また、高周波加熱装置１００には、これらを発振駆動する高周波駆動部１７、制御部１９とが設けられ、この制御部１９には、加熱開始を指示するスタートスイッチや、加熱内容を設定するメニュースイッチ等の入力操作部２１と、各種情報を表示する表示部２３が接続されている。制御部１９は、入力操作部２１からの入力内容に基づいて高周波発生部を駆動制御して、載置台２０上の被加熱物Ｍを所望の条件で加熱する。
【００３０】
第１高周波発生部１３は、周波数が２．４５ＧＨｚの高周波を発振するマグネトロン２５と、マグネトロン２５のアンテナ２５ａから出力された高周波を加熱室１１の底面側に設けた下側給電口２７へ導く下側導波管２９とを有している。また同様に、第２高周波発生部１５は、周波数が５．８ＧＨｚの高周波を発振するマグネトロン３１と、マグネトロン３１のアンテナ３１ａから出力された高周波を加熱室１１の上面側に設けた上側給電口３３へ導く上側導波管３５とを有している。
【００３１】
高周波駆動部１７は、図２に一例を示すように、各マグネトロン２５，３１を個別に駆動するインバータ回路を備えている。マグネトロン２５を駆動する第１インバータ回路３７には、商用電源４９からの電力がダイオードブリッジ等の整流回路５１によって全波整流されて供給され、これを高周波電圧に変換した後に昇圧トランス５３の一次巻線５５に印加する。すると、昇圧トランス５３の二次巻線５７に数ｋＶの高周波の高電圧が発生する。そして、この高周波高電圧は、コンデンサ５８やダイオード５９からなる倍電圧整流回路６１によって整流されて、マグネトロン２５に高電圧が印加される。また、昇圧トランス５３のヒータ巻線６３は、マグネトロン２５のフィラメント６５に接続され、フィラメント６５を加熱する。そして、マグネトロン２５は、フィラメント６５の加熱と高電圧の印加により高周波を発振する。
【００３２】
上記のマグネトロン２５を駆動する第１インバータ回路３７、昇圧トランス５３、及び倍電圧整流回路６１の各構成は、マグネトロン３１を駆動する第２インバータ回路６７、昇圧トランス６９、及び倍電圧整流回路７１の構成と同様であるので、同一の機能を有する部分については同一の符号を付与することでその説明は省略するものとする。
【００３３】
そして、第１インバータ回路３７と第２インバータ回路６７には駆動制御部７３が接続されており、駆動制御部７３が双方の回路の駆動タイミングや給電配分等を制御部１９からの制御信号を受けて制御する。
【００３４】
ここで、加熱室１１に供給する２種類の周波数の高周波に対する電波洩れ防止用のチョークについて説明する。
図３に高周波加熱装置１００の外観斜視図を示した。箱形の加熱室１１は、高周波加熱装置１００の一側面となる前面側に開閉自在に取り付けられた開閉扉７５により開口し、この開口部から加熱室１１内への被加熱物の出し入れを可能とする構成になっている。つまり、加熱室１１は、開口部を有する加熱室本体７７が、開閉扉７５により開閉自在になるため、開閉扉７５からの電波洩れを防止するためのチョーク７９が、加熱室本体７７と対向する開閉扉７５の部分に形成されている。このチョーク７９は加熱室本体７７側の開閉扉７５と対向する部分に形成してもよい。
【００３５】
ここで、図４に図３のＡ−Ａ断面（ａ）とＢ−Ｂ断面（ｂ）、及び図５にチョークの斜視図を示した。このチョーク７９の形状に関しては、特許第１５０４２０１号に記載のチョークと周波数は異なるものの略同様の構成となっている。即ち、図４（ａ）に示すように、開閉扉７５を形成する金属板８３の端部で、折り曲げ加工により溝８５を形成することで基端側壁面８７を形成し、さらに金属板８３の先端をＵ字状に折り曲げて、溝幅がｂ１の開孔部側溝８５ａと、溝幅がｂ２の短絡側溝８５ｂの壁面を形成している。そして、図５に示すように、開孔部側溝８５ａの側で、導線幅をａ１，ａ３、短絡側溝８５ｂの側で導線幅をａ２，ａ４として複数の導体片８１ａを形成している。
また、図４（ｂ）のＢ−Ｂ断面においては、開孔部側溝８５ａの側で溝幅をｂ３、短絡側溝８５ｂの側でｂ４として、前記導体片８１ａと同様の形状の導体片８１ｂを複数形成している。
【００３６】
これら導体片８１ａ，８１ｂは溝８５内に互い違いに収容され、溝８５の開孔端は溝カバー８９によって覆われており、また、開閉扉７５の外側はドアカバー９１で覆われている。上記構成のチョーク７９では、断面Ａ−Ａで示す溝における特性インピーダンスの比Ｋ_１は、（１）式で表される。
【００３７】
【数１】

【００３８】
また、断面Ｂ−Ｂで示す溝における特性インピーダンスの比Ｋ_２は、（２）式で表される。
【００３９】
【数２】

【００４０】
上記Ｋ_１、Ｋ_２の各値は、溝の深さ（Ｌ_１＋Ｌ_２）と（Ｌ_３＋Ｌ_４）が同一になるようにそれぞれ設定している。なお、ε_ｅｆｆ１、ε_ｅｆｆ２はそれぞれの溝部の実効誘電率である。
【００４１】
ここで、溝開孔部側溝の特性インピーダンス、長さ、位相定数をＺ_Ｏ１、Ｌ_１，β_１とし、溝短絡部側溝の特性インピーダンス、長さ、位相定数をＺ_Ｏ２、Ｌ_２，β_２とする。そして、溝の開孔端から短絡端までの距離（溝の深さ）をＬ（ｔｏｔａｌ）とするとＬ（ｔｏｔａｌ）＝Ｌ_１＋Ｌ_２となる。上記条件で溝の開孔端のインピーダンスＺは（３）式で表せる。
【００４２】
【数３】

但し、Ｋ＝Ｚ_Ｏ２／Ｚ_Ｏ１
【００４３】
本実施形態では、特性インピーダンスがＺ_Ｏ２ ≠Ｚ_Ｏ１であるから、（３）式において特性インピーダンスの比Ｋの値は、Ｋ≠１となる。溝の開孔端のインピーダンスＺを無限大にするためには、（３）式の分母がゼロになればよいので、１＝Ｋｔａｎβ_１Ｌ_１・ｔａｎβ_２Ｌ_２を満たせばよい。そのため、前記Ｋ_１，Ｋ_２の値は、ａ_１，ａ_２，ａ_３，ａ_４及び、ｂ_１，ｂ_２，ｂ_３，ｂ_４を調整することで任意に設定できるので、これらＫ_１、Ｋ_２を適切に設定することにより、１つの溝で２．４５ＧＨｚと５．８ＧＨｚとの２種類の周波数に対してシール効果を持たせることができる。
【００４４】
即ち、５．８ＧＨｚの高周波に対する溝の深さ（Ｌ_３＋Ｌ_４）と２．４５ＧＨｚの溝の深さ（Ｌ_１＋Ｌ_２）とが同一になるように特性インピーダンス比Ｋの値を決定する。例えば、２．４５ＧＨｚに対する特性インピーダンス比Ｋ_１に基づき、溝の深さ（Ｌ_１＋Ｌ_２）を決定し、それに合致するように、５．８ＧＨｚに対する特性インピーダンス比Ｋ_２の値を決定する。例えば開閉扉の厚みを２０ｍｍ程度とする場合、Ｋ_１＞１、Ｋ_２＜１の組み合わせとすることで、２．４５ＧＨｚと５．８ＧＨｚとの２種類の高周波に対して有効に作用する電波洩れ防止用溝を構成することができる。
【００４５】
上述したように、本実施形態のチョークの構成では、加熱室本体７７と開閉扉７５とが対向する部分の少なくとも一方に１つ以上の溝を設け、この溝の少なくとも一つの壁面は、溝の長手方向に間隔をおいて連続的に並べ、かつ、溝の壁面に平行な導体片群により構成され、導体片を溝幅が周期的に変化するように配置して導線路を構成し、溝内で誘電率、導線路幅、溝幅のうち少なくともいずれか１つを変化させて溝の開口部の特性インピーダンスと、溝の短絡端部の特性インピーダンスの比を周期的に変えることにより、異なる２つの周波数の高周波を同時に遮蔽することが可能となる。
【００４６】
以上説明した高周波加熱装置の構成においては、図６に高周波加熱装置の一部概略断面を示すように、必要に応じて電波撹拌用のスタラー羽根９３を導波管２９の下側給電口２７近傍に設け、スタラー羽根９３の回転駆動により加熱室１１へ供給する電波を強制的に撹拌して、より均一な加熱が図れるようにしてもよい。
【００４７】
また、図７に高周波加熱装置の概略断面図を示すように、加熱室１１の底面に回転自在に軸支されたターンテーブル９５を設け、均一加熱を図る構成としてもよい。この場合には、第１高周波発生部１３を第２高周波発生部１５と共に加熱室１１の上側に配置して、第２高周波発生部１５の上側給電口３３の近傍から高周波を加熱室１１内に供給する構成としてもよく（図７（ａ）参照）、また、第１高周波発生部１３を加熱室１１の側面に設け、側面から高周波を加熱室１１内に供給する構成としてもよい（図７（ｂ）参照）。
【００４８】
次に、本発明に係る高周波加熱装置１００の作用を説明する。
本発明の高周波加熱装置１００を用いて、被加熱物Ｍを加熱処理する際、加熱室１１には、第１高周波発生部１３からの２．４５ＧＨｚの高周波、及び第２高周波発生部１５からの５．８ＧＨｚの高周波の少なくともいずれか一方が個別に或いは同時に供給される。
図８に加熱室１１に現れるある瞬間の定在波の状態を一例として示した。（ａ）は２．４５ＧＨｚの高周波、（ｂ）は５．８ＧＨｚの高周波、（ｃ）は２．４５ＧＨｚと５．４５ＧＨｚの高周波の合波として示している。
【００４９】
図８（ａ）に示す２．４５ＧＨｚの高周波では、加熱量が多くなる電界の波腹の部分の間隔（加熱スポットの間隔）が約６ｃｍとなり、例えば３０ｃｍの長さの被加熱物Ｍに対しては、直線上に定在波の波腹の部分が僅か５点程度しか含み得ない。従って、被加熱物Ｍには加熱スポット位置とそれ以外の位置とでは昇温特性に大きく差が生じて加熱ムラが生じやすくなる。
一方、図８（ｂ）に示す５．８ＧＨｚの高周波では、加熱スポットの間隔が約２．６ｃｍとなり、上記長さでは直線上で１０点以上の加熱スポットが被加熱物Ｍに含み得る。このため、被加熱物Ｍが均等に加熱されて被加熱物Ｍの場所による加熱ムラが生じにくくなる。
【００５０】
しかし、５．８ＧＨｚの高周波では、被加熱物Ｍに対する吸収深さが浅くなる傾向があり、２．４５ＧＨｚの高周波が被加熱物Ｍの表面から約５〜７ｃｍであるのに対し、５．８ＧＨｚの高周波では表面から約２〜３ｃｍと浅くなる。従って、５．８ＧＨｚの高周波のみ用いて被加熱物Ｍを加熱する場合には、被加熱物Ｍが薄肉のものであればよいが、厚肉の場合は、被加熱物Ｍの内部と表面との間で温度差が大きくなり、加熱ムラが生じやすくなる。
【００５１】
そこで、図８（ｃ）に示すように、２．４５ＧＨｚの高周波と５．８ＧＨｚの高周波とを同時に供給することで、被加熱物Ｍが厚肉の場合でも加熱ムラを小さく抑えて均一加熱を実現することが可能となる。即ち、２．４５ＧＨｚの高周波と５．８ＧＨｚの高周波が重なり合うと、加熱量が小さくなる定在波の谷の部分でもバイアスが上がることで加熱効果が得られ、これにより高周波の加熱効果の均等化が図れ、被加熱物Ｍの場所や厚みによらない均一加熱が実現できる。
【００５２】
上記各高周波の特性とこれによる加熱効果の違いを纏めて表１に示した。
【表１】

【００５３】
被加熱物Ｍの加熱分布特性に関しては、５．８ＧＨｚの高周波が表面積の大きいピザや肉スライス品等の加熱に好適に利用でき、加熱ムラの発生を抑えることができる反面、２．４５ＧＨｚの高周波は前述した加熱ポイントが少ないために加熱ムラが生じやすくなる。しかし、５．８ＧＨｚの高周波と組み合わせることで薄肉品であっても均一加熱が実現できる。また、厚肉の被加熱物に対しては２．４５ＧＨｚの高周波の方が有利となり、５．８ＧＨｚの高周波では、被加熱物の内部にまで熱が通らずに、表面からの熱伝導による加熱となって加熱時間が長くかかる傾向があるが、２．４５ＧＨｚの高周波との組み合わせにより、被加熱物内部まで迅速な加熱が可能となる。
なお、２．４５ＧＨｚの高周波と５．８ＧＨｚの高周波を交互に切り替えて供給する場合でも、実質的に上記同様の効果を得ることができる。
以上のように、異なる周波数の高周波を用い、また、各々の電力配分を調整することにより、種々の形態の定在波分布を形成でき、ムラの少ない加熱、さらには局部的な加熱処理が実現できる。
【００５４】
次に、本発明に係る高周波加熱装置の第２実施形態を説明する。
図９に本実施形態の高周波加熱装置の概念的な断面構成図を示した。なお、前述した第１実施形態の構成と同一の機能を有する部材に対しては同一の符号を付与することでその説明は省略するものとする。
本実施形態の高周波加熱装置２００は、図９に示すように、加熱室１１の下側から第１高周波発生部１３からの２．４５ＧＨｚの高周波を供給し、加熱室１１の上側から第２高周波発生部１５からの５．８ＧＨｚの高周波を供給する構成であって、加熱室１１の全高Ｈに対して、加熱室１１上面から距離ｈの位置に加熱室１１の空間を上下に分割する仕切板９７を設けている。
仕切板９７は、加熱室１１に対して複数の高さ位置に容易に脱着自在とされており、加熱室１１の壁面に形成した係止部９９に支持されて取り付けられる。この仕切板９７は、図１０に仕切板の断面図を示すように、被加熱物の載置面となる金属板１０１と、金属板１０１に対峙してあるいは接触して配置される高周波発熱体１０３と、高周波発熱体１０３を金属板１０１に固定すると共に加熱室１１側の係止部９９と係合する固定部材１０５とを有する。
【００５５】
金属板１０１は、アルミメッキ鋼板からなり、金属板１０１自体を波形として凹凸を形成したり、金属板上１０１に凸部を形成したりすることで表面に波状の凹凸を設けている。なお、アルミメッキ鋼板の表側面には防汚効果の高いフッ素塗装を施し、裏側面には吸熱効果の高い黒色耐熱塗装を施している。
高周波発熱体１０３は、金属板１０１側とは反対側の面に、高周波を吸収して発熱する窒化物及び硼化物からなる高周波発熱膜１０３ａを基体１０３ｂに密着させて形成している。基体１０３ｂは、セラミック材又は耐熱樹脂材からなり、蓄熱効果の高い材料が好適に用いられる。
固定部材１０５は、仕切板９７の加熱室１１への挿入方向に沿って両脇側に設けられた絶縁体からなり、加熱室１１との間に隙間を形成することで、高周波加熱時におけるスパークの発生を防止している。
【００５６】
また、金属板１０１を波形にすることで、高周波吸収膜１０３ａと金属板１０１のとの距離が遠くなり、これにより、高周波吸収膜１０３ａ上における電界強度が高くなり、高周波吸収膜１０３ａ上での発熱量が増加する効果も得られる。なお、高周波発熱体１０３として、裏面に高周波発熱膜１０３ａを設けた構成以外にも、高周波発熱体自身を高周波で発熱するセラミックで形成してもよい。
【００５７】
金属板１０１として、金属製のアルミメッキ鋼板を用いたが、表面で高周波を反射するものであれば、セラミック質の基材に金属メッキや金属蒸着等で高周波の反射層を設けたもの等も利用でき、さらには、ステンレス、アルミニウム及びアルミニウム合金、亜鉛メッキ鋼板、アルミ亜鉛合金メッキ鋼板や銅メッキ鋼板などの各種メッキ鋼板、冷間圧延鋼板、クラッド材等も用いることができる。また、高周波吸収膜８１として窒化物や硼化物を用いたが、酸化スズ、酸化インジウム等の金属酸化物、及び複合酸化物等も用いることができる。
【００５８】
上記構成の高周波加熱装置２００によれば、加熱室１１が上側空間と下側空間と２つの空間に分割され、それぞれの空間で所望の加熱処理が実施できる。
即ち、この高周波加熱装置２００では、加熱室１１の上側空間１１ａに第２高周波発生部１５からの５．８ＧＨｚの高周波が供給され、また、加熱室１１の下側空間１１ｂに第１高周波発生部１３からの２．４５ＧＨｚの高周波が供給される。上側空間１１ａの仕切板９７上に載置された被加熱物Ｍは、上側から供給される５．８ＧＨｚの高周波により加熱され、また、下側から供給される２．４５ＧＨｚの高周波による高周波発熱体１０３の発熱によっても加熱される。この場合、上側空間１１ａでは、所謂グリル調理が行われる。一方、下側空間１１ｂでは、被加熱物Ｍを加熱室１１の底面に載置することで、２．４５ＧＨｚの高周波加熱がなされることとなる。
【００５９】
なお、上記の仕切板９７に高周波発熱体１０３を設けない構成としてもよい。その場合には、上側空間においては、下側からの高周波による加熱を制限して上側からの高周波加熱を主体に被加熱物Ｍを加熱処理することができる。
【００６０】
また、上側から供給する高周波を５．８ＧＨｚ、下側から供給する高周波を２．４５ＧＨｚとしても構わない。
【００６１】
上記構成によれば、前述した各周波数の高周波を共通の加熱室１１に供給する以外にも、それぞれ個別の加熱空間１１ａ，１１ｂを形成して、それぞれの空間１１ａ，１１ｂで個別に各周波数の高周波による加熱が実施できる。これにより、被加熱物Ｍの大きさに対して必要以上の空間を用意して必要以上の加熱エネルギを供給することがなく、任意の大きさに空間を設定することで、無駄の少ない高効率な加熱が可能となる。
【００６２】
なお、脱着自在な仕切板９７に代えて固定型の仕切構造とし、各周波数の高周波による個別の加熱空間を形成する構成としてもよい。この場合には、仕切板９７の脱着動作が不要となり、加熱操作が単純化できる。
【００６３】
ここで、高周波加熱装置１００の高周波駆動部１７の構成を単純化した構成例を説明する。
図２に示すように、高周波駆動部１７には各マグネトロン２５，３１を個別に駆動するインバータ回路をそれぞれ備えていたが、図１１に示す高周波駆動部の他の構成例を示すように、単一のインバータ回路で駆動する構成としてもよい。つまり、インバータ回路１０７に接続され、且つ駆動するマグネトロンを切り替えるための切り替えスイッチ１０９を切り替え制御する駆動制御部１１１を備え、切り替えスイッチ１０９を制御部１９（図１参照）からの信号に基づいて適宜なタイミングで切り替え制御することで、２．８ＧＨｚの高周波と２．４５ＧＨｚの高周波を交互に出力可能にした構成となっている。
【００６４】
上記構成の高周波駆動部１８によれば、２つの異なる種類のマグネトロン２５，３１を単一のインバータ回路で駆動することができるので、高周波駆動部１８の回路構成を大幅に簡略化でき、必要とする設置スペースが小さく済み、装置の小型軽量化に寄与することができる。
【００６５】
次に、第１高周波発生部１３と第２高周波発生部１５の駆動制御について説明する。
制御部１９（図１参照）は、電源からの電力を第１高周波発生部１３である２．４５ＧＨｚ用のマグネトロン２５と第２高周波発生部１５である５．８ＧＨｚ用のマグネトロン３１とに分配する信号を駆動制御部７３（図２参照）に出力し、駆動制御部７３は、この分配信号を受けて第１インバータ回路３７と第２インバータ回路６７とに給電配分する。
【００６６】
このときの、第１高周波発生部１３、第２高周波発生部１５への給電パターンについて、図１２〜図１５を用いて説明する。
図１２は５．８ＧＨｚと２．４５ＧＨｚの高周波を交互に出力するパターンである。この給電パターンによれば、交互に出力が行われ、双方の高周波を同時に出力することがないので、各高周波の出力を高周波加熱装置の定格電力まで印加して出力させることができる。従って、各高周波発生部を最大の出力にして被加熱物を効率良く加熱することができる。
【００６７】
図１３は５．８ＧＨｚと２．４５ＧＨｚの高周波を同時に出力するパターンである。このときの出力は、双方の高周波の合計電力が高周波加熱装置の定格電力を超えないように制御される。図中には、定格電力をＰとしたときに例えば双方の高周波の電力をそれぞれＰ／２に設定する状態を示した。電力分配の割合は、これ以外にも任意の割合に設定でき、また、例えば所定時間経過後に電力分配の割合を変更することも可能である。
【００６８】
図１４は２．４５ＧＨｚの高周波を先に出力して５．８ＧＨｚの高周波を後から出力するパターンである。このパターンによれば、被加熱物の温度が低い加熱初期に、加熱効果が比較的高い２．４５ＧＨｚの高周波を供給して被加熱物を一気に昇温させ、また、所定時間経過後或いは所定温度到達後に５．８ＧＨｚの高周波を供給することで、加熱温度の均一化を図り、温度分布の少ない均一加熱状態にすることができる。また、これとは逆に先に５．８ＧＨｚの高周波を出力して２．４５ＧＨｚの高周波を後から出力するパターンとしてもよい。この場合には、加熱後半に強く加熱する調理等に好適となる。なお、加熱後半の各高周波を同時に出力する際に、各高周波を図１２に示すような交互に出力するパターンにしてもよい。その場合には、各出力を最大出力まで印加することができる。
【００６９】
図１５は５．８ＧＨｚの高周波のみ出力するパターンである。このパターンでは特に薄肉の被加熱物の加熱に好適となり、温度分布の少ない状態に仕上げることができる。また、２．４５ＧＨｚの高周波のみ出力するパターンとしてもよい。この場合には、従前同様の高周波加熱が行える。
【００７０】
【発明の効果】
以上詳細に説明したように、本発明に係る高周波加熱装置によれば、被加熱物を収容する加熱室に高周波発生部から高周波を供給し、被加熱物を加熱処理する高周波加熱装置であって、高周波発生部が、周波数が２．４５ＧＨｚの高周波を発生する第１高周波発生部と、周波数が５．８ＧＨｚの高周波を発生する第２高周波発生部とを備えることにより、加熱効果の高い周波数が２．４５ＧＨｚの高周波と、加熱分布が均一な周波数が５．８ＧＨｚの高周波との２種類の高周波を加熱室に供給することができ、加熱ムラの発生を抑制して、厚肉の被加熱物であっても迅速に均一加熱処理が可能となる。
また、本発明に係る高周波加熱装置の制御方法によれば、周波数が２．４５ＧＨｚの高周波と周波数が５．８ＧＨｚの高周波とを同時に又は交互に前記加熱室に供給することにより、加熱効果の高い２．４５ＧＨｚの高周波と、均一加熱効果の高い５．８ＧＨｚの高周波とが選択的に供給可能となるので、被加熱物の形状や加熱目的に応じた適切な高周波を供給して効率の良い加熱処理を行うことができる。
【図面の簡単な説明】
【図１】本発明に係る高周波加熱装置の概念的な構成図である。
【図２】高周波加熱装置の高周波駆動部の構成図である。
【図３】電波洩れ防止用のチョークを説明するための高周波加熱装置の外観斜視図である。
【図４】図３のＡ−Ａ断面（ａ）とＢ−Ｂ断面（ｂ）を示す断面図である。
【図５】チョークの斜視図である。
【図６】スタラー羽根を説明するための高周波加熱装置の一部概略断面である。
【図７】高周波加熱装置の概略断面図であって、（ａ）は２．４５ＧＨｚの高周波の上方給電、（ｂ）は側方給電を示す説明図である。
【図８】加熱室に現れるある瞬間の定在波の状態で（ａ）は２．４５ＧＨｚの高周波、（ｂ）は５．８ＧＨｚの高周波、（ｃ）は２．４５ＧＨｚと５．４５ＧＨｚの高周波の合波を示す説明図である。
【図９】仕切板により加熱室を上下に分割した周波加熱装置の概念的な断面構成図である。
【図１０】仕切板の断面図である。
【図１１】高周波駆動部の他の構成例を示す構成図である。
【図１２】第１高周波発生部、第２高周波発生部への給電パターンであって、５．８ＧＨｚと２．４５ＧＨｚの高周波を交互に出力するパターンを示す説明図である。
【図１３】第１高周波発生部、第２高周波発生部への給電パターンであって、５．８ＧＨｚと２．４５ＧＨｚの高周波を同時に出力するパターンを示す説明図である。
【図１４】第１高周波発生部、第２高周波発生部への給電パターンであって、２．４５ＧＨｚの高周波を先に出力して５．８ＧＨｚの高周波を後から出力するパターンを示す説明図である。
【図１５】第１高周波発生部、第２高周波発生部への給電パターンであって、５．８ＧＨｚの高周波のみ出力するパターンを示す説明図である。
【符号の説明】
１１加熱室
１３第１高周波発生部
１５第２高周波発生部
１７高周波駆動部
１９制御部
２５マグネトロン（２．４５ＧＨｚ用）
２７下側給電口
２９下側導波管
３１マグネトロン（５．８ＧＨｚ用）
３３上側給電口
３５上側導波管
３７第１インバータ回路
６７第２インバータ回路
７３駆動制御部
７５開閉扉
７７加熱室本体
７９チョーク
８１導体片
８３金属板
８５溝
９７仕切板
１００，２００高周波加熱装置
１０９切り替えスイッチ
１１１駆動制御部
Ｍ被加熱物[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency heating apparatus that supplies a high frequency to a heating chamber that accommodates the object to be heated and heats the object to be heated, and a control method thereof, and more particularly to a technique that uses a high frequency including a frequency component of 5.8 GHz.
[0002]
[Prior art]
Conventionally, a high-frequency heating apparatus that heats and cooks a heated object by supplying a high frequency to a heating chamber that houses the object to be heated has been widely used for cooking food. This type of high-frequency heating apparatus is equipped with a magnetron that generates a high frequency of 2.45 GHz, and supplies the generated high frequency into the heating chamber. In the heating chamber, a standing wave is formed by supplying a high frequency, the wavelength of the generated standing wave is about 12 cm, and a substantial heating spot with a strong electric field is generated at an interval of about 6 cm, which is 1/2 of the standing wave. become. However, since the interval between the heating spots is longer than the size of the food to be cooked, the distribution density of the heating spots that may be present in the food is reduced, and the food is partially heated, which tends to cause uneven heating. There was a trend
Therefore, a technique for reducing the heating unevenness of the object to be heated by changing the frequency of the high frequency to be used from 2.45 GHz to 5.8 GHz to narrow the interval between the heating spots, thereby increasing the distribution density of the heating spots. Has been proposed (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
JP-A-3-203191
[0004]
[Problems to be solved by the invention]
However, the high frequency of 5.8 GHz increases the distribution density of the heating spot as compared to the high frequency of 2.45 GHz, but the absorption depth to the heated object is shallow, so that the heated object is thick. The surface of the object to be heated is mainly heated, and uneven heating tends to occur such that the inside of the object to be heated becomes insufficiently heated.
Therefore, at a high frequency of 5.8 GHz where the heating distribution is dense, a good uniform heating effect can be expected if the object to be heated is thin, but for thick objects to be heated, uneven heating in the depth direction is expected. As a result, uniform heating becomes difficult. Even in the case of a thick wall, the inside is heated by heat conduction from the surface of the object to be heated, but it takes time until the heat is transmitted to the inside, and the rapid heating effect that is the greatest advantage of high-frequency heating is not achieved become.
[0005]
The present invention has been made in view of the above circumstances, and provides a high-frequency heating apparatus and a control method thereof that suppress the occurrence of heating unevenness and can quickly and uniformly heat even a thick object to be heated. The purpose is to do.
[0006]
[Means for Solving the Problems]
The above object is achieved by the following configuration.
(1) A high-frequency heating device that supplies a high frequency from a high-frequency generator to a heating chamber that accommodates an object to be heated, and heats the object to be heated. The high-frequency generator generates a high frequency with a frequency of 2.45 GHz. A high-frequency heating device comprising: a first high-frequency generator that generates a high frequency of 5.8 GHz.
[0007]
According to this high-frequency heating device, two types of high frequency, that is, a high frequency with a high heating effect of 2.45 GHz and a high frequency with a uniform heating distribution of 5.8 GHz can be supplied to the heating chamber. Occurrence of unevenness can be suppressed, and even a thick object to be heated can be quickly and uniformly heated.
[0008]
(2) a first inverter circuit that supplies driving power to the first high-frequency generator, a second inverter circuit that supplies driving power to the second high-frequency generator, and the first high-frequency generator by these inverter circuits The high-frequency heating device according to (1), further comprising a drive control unit that drives the second high-frequency generation unit simultaneously or alternately.
[0009]
According to this high-frequency heating device, since the driving power to the first high-frequency generator and the second high-frequency generator is supplied by separate inverter circuits, it is possible to output high frequencies simultaneously or alternately from each high-frequency generator. In addition, since the output intensity can be made variable, even a complicated heating pattern can be easily controlled.
[0010]
(3) A single inverter circuit that supplies driving power to the first high-frequency generator and the second high-frequency generator, and driving by alternately switching power supply to the first high-frequency generator and the second high-frequency generator The high-frequency heating device according to (1), further comprising: a drive control unit that performs the operation.
[0011]
According to this high-frequency heating device, since the power supply to the first high-frequency generator and the second high-frequency generator can be controlled by a single inverter circuit, the circuit configuration of the drive controller is simplified, and the space required for installation Can be reduced, and can contribute to reduction in size and weight of the apparatus.
[0012]
(4) An upper power supply port provided on the upper surface of the heating chamber for introducing a high frequency into the heating chamber, and a lower power supply port provided on a lower surface of the heating chamber for introducing a high frequency into the heating chamber. The high frequency heating apparatus according to any one of (1) to (3), wherein a high frequency from the first high frequency generation unit or the second high frequency generation unit is individually introduced from each of a power supply port and a lower power supply port.
[0013]
According to this high-frequency heating device, the high frequency from the first high-frequency generator or the second high-frequency generator is individually introduced into the heating chamber from each of the upper power supply port and the lower power supply port. Each high frequency can be irradiated from the optimum position.
[0014]
(5) The high-frequency heating device according to (4), wherein a partition plate that divides the space of the heating chamber vertically is provided.
[0015]
According to this high-frequency heating device, by dividing the space of the heating chamber vertically, one high frequency can be supplied to the upper space and the other high frequency can be supplied to the lower space. It can be supplied to and heated.
[0016]
(6) The high frequency heating apparatus according to (5), wherein the partition plate includes a high frequency heating element, and generates heat when irradiated with high frequency.
[0017]
According to this high-frequency heating device, the high-frequency heating element of the partition plate generates heat by high-frequency irradiation, so the object to be heated placed on the partition plate is heated by radiant heat or conduction heat, and the object to be heated is burnt. Can be attached. Also, the heating chamber can be warmed to have a preheating effect.
[0018]
(7) The high frequency heating apparatus according to any one of (4) to (6), wherein a high frequency from the second high frequency generator is introduced into the heating chamber from an upper power supply port of the heating chamber.
[0019]
According to this high frequency heating device, the high frequency of 5.8 GHz from the second high frequency generator is supplied from the upper power supply port, so that the object to be heated in the heating chamber can be heated uniformly.
[0020]
(8) The heating chamber includes a heating chamber main body having an opening and an opening / closing door that covers the opening so as to be freely opened and closed, and at least one of the portions where the heating chamber main body and the opening / closing door face each other, The choke for preventing radio wave leakage is formed, and the choke shields each high frequency from the first high frequency generator and the second high frequency generator. (1) to (7) High frequency heating device.
[0021]
According to this high-frequency heating device, although it is a small choke, when the open / close door is closed, two types of high-frequency waves supplied to the inside of the heating chamber do not leak out.
[0022]
(9) A method of controlling a high-frequency heating apparatus that supplies a high frequency from a high-frequency generator to a heating chamber that accommodates an object to be heated and heat-treats the object to be heated, the frequency being 2.45 GHz from the high-frequency generator A control method for a high-frequency heating device that supplies a high frequency and a high frequency of 5.8 GHz to the heating chamber simultaneously or alternately.
[0023]
According to this high frequency heating apparatus control method, a high frequency of 2.45 GHz having a high heating effect is obtained by supplying a high frequency of 2.45 GHz and a high frequency of 5.8 GHz to the heating chamber simultaneously or alternately. And a high frequency of 5.8 GHz, which has a high uniform heating effect, can be selectively supplied. Therefore, an efficient heat treatment can be performed by supplying an appropriate high frequency according to the shape of the object to be heated and the heating purpose. it can.
[0024]
(10) The high-frequency heating according to (9), wherein any one of the frequencies is output at an early stage of heating, and the output of the other high-frequency is started after a predetermined time has elapsed or a predetermined temperature has been reached since the start of heating. Control method of the device.
[0025]
According to this high frequency heating apparatus control method, a high frequency with a high heating effect is supplied at a high frequency of 2.45 GHz at the initial stage of heating, the temperature of the object to be heated is increased all at once, and the frequency is reached after a predetermined time has passed or a predetermined temperature has been reached. However, by supplying a high frequency of 5.8 GHz, the heating temperature can be made uniform, and the object to be heated can be brought into a uniform heating state with a small temperature distribution. On the other hand, when a high frequency of 5.8 GHz is supplied first and a high frequency of 2.45 GHz is supplied later, the heating pattern is suitable for cooking that heats strongly in the second half of heating.
[0026]
(11) When simultaneously outputting the respective frequencies, at least one of the outputs of each high frequency is limited so that the sum of driving power for the high frequency output does not exceed the rated power of the high frequency heating device ( The control method of the high-frequency heating device according to 9) or (10).
[0027]
According to this high frequency heating device control method, when the output of each high frequency exceeds the rated power, the output of either one of the high frequencies is limited, and the total driving power for the high frequency output is high frequency heating. The rated power of the device can not be exceeded.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a high-frequency heating device and a control method thereof according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a conceptual configuration diagram of a high-frequency heating device according to the present invention, and FIG. 2 is a configuration diagram of a high-frequency driving unit of the high-frequency heating device.
[0029]
As shown in FIG. 1, the high-frequency heating apparatus 100 supplies a high frequency to a heating chamber 11 that accommodates an object to be heated M, and heats the object to be heated M. A first high frequency generator 13 that generates a high frequency of 2.45 GHz and a second high frequency generator 15 that generates a high frequency of 5.8 GHz are provided. Further, the high-frequency heating device 100 is provided with a high-frequency drive unit 17 and a control unit 19 for oscillating and driving them. The control unit 19 includes a start switch for instructing the start of heating and a menu switch for setting the heating content. Are connected to a display unit 23 for displaying various types of information. The control unit 19 drives and controls the high-frequency generation unit based on the input content from the input operation unit 21 to heat the article to be heated M on the mounting table 20 under a desired condition.
[0030]
The first high frequency generator 13 has a magnetron 25 that oscillates a high frequency of 2.45 GHz and a high frequency output from an antenna 25a of the magnetron 25 to a lower power supply port 27 provided on the bottom surface side of the heating chamber 11. And a side waveguide 29. Similarly, the second high frequency generator 15 includes a magnetron 31 that oscillates a high frequency of 5.8 GHz, and an upper power supply port 33 provided with a high frequency output from the antenna 31 a of the magnetron 31 on the upper surface side of the heating chamber 11. And an upper waveguide 35 leading to
[0031]
The high frequency drive part 17 is provided with the inverter circuit which drives each

magnetron

25 and 31 separately so that an example may be shown in FIG. The first inverter circuit 37 that drives the magnetron 25 is supplied with the electric power from the commercial power supply 49 after being full-wave rectified by a rectifier circuit 51 such as a diode bridge, converted into a high-frequency voltage, and then the primary winding of the step-up transformer 53. Apply to line 55. Then, a high-frequency high voltage of several kV is generated in the secondary winding 57 of the step-up transformer 53. The high frequency high voltage is rectified by a voltage doubler rectifier circuit 61 including a capacitor 58 and a diode 59, and a high voltage is applied to the magnetron 25. The heater winding 63 of the step-up transformer 53 is connected to the filament 65 of the magnetron 25 and heats the filament 65. The magnetron 25 oscillates a high frequency by heating the filament 65 and applying a high voltage.
[0032]
The configurations of the first inverter circuit 37, the step-up transformer 53, and the voltage doubler rectifier circuit 61 that drive the magnetron 25 are the same as those of the second inverter circuit 67, the step-up transformer 69, and the voltage doubler rectifier circuit 71 that drive the magnetron 31, respectively. Since it is the same as that of a structure, about the part which has the same function, the description shall be abbreviate | omitted by providing the same code | symbol.
[0033]
A drive control unit 73 is connected to the first inverter circuit 37 and the second inverter circuit 67, and the drive control unit 73 receives control signals from the control unit 19 for the drive timing and power distribution of both circuits. Control.
[0034]
Here, a description will be given of a choke for preventing radio wave leakage with respect to high frequencies of two types of frequencies supplied to the heating chamber 11.
FIG. 3 shows an external perspective view of the high-frequency heating device 100. The box-shaped heating chamber 11 is opened by an open / close door 75 attached to the front side, which is one side surface of the high-frequency heating device 100, so that an object to be heated can be taken into and out of the heating chamber 11 from the opening. It is the composition that. That is, in the heating chamber 11, the heating chamber main body 77 having an opening can be opened and closed by the opening / closing door 75, so that the choke 79 for preventing radio wave leakage from the opening / closing door 75 faces the heating chamber main body 77. An opening / closing door 75 is formed. The chalk 79 may be formed in a portion facing the opening / closing door 75 on the heating chamber body 77 side.
[0035]
Here, FIG. 4 shows an AA cross section (a) and a BB cross section (b) of FIG. 3, and FIG. 5 shows a perspective view of the choke. The shape of the choke 79 is substantially the same as that of the choke described in Japanese Patent No. 1504201, although the frequency is different. That is, as shown in FIG. 4A, a base end side wall surface 87 is formed by forming a groove 85 by bending at an end portion of the metal plate 83 forming the open / close door 75, and further, The front end is bent in a U-shape to form wall surfaces of the opening side groove 85a having a groove width b1 and the short-circuit side groove 85b having a groove width b2. As shown in FIG. 5, a plurality of conductor pieces 81a are formed on the opening portion side groove 85a side with the conductor wire widths a1 and a3 and on the short side groove 85b side with the conductor wire widths a2 and a4.
4B, a conductor piece 81b having the same shape as the conductor piece 81a is formed with the groove width b3 on the opening side groove 85a side and b4 on the short side groove 85b side. A plurality are formed.
[0036]
The

conductor pieces

81 a and 81 b are alternately accommodated in the groove 85, the opening end of the groove 85 is covered with the groove cover 89, and the outside of the opening / closing door 75 is covered with the door cover 91. In the choke 79 having the above configuration, the characteristic impedance ratio K in the groove indicated by the section AA is shown.₁Is represented by equation (1).
[0037]
[Expression 1]

[0038]
Further, the characteristic impedance ratio K in the groove shown by the cross section BB₂Is represented by equation (2).
[0039]
[Expression 2]

[0040]
K above₁, K₂Each value of is the groove depth (L₁+ L₂) And (L₃+ L₄) Are set to be the same. Ε_eff1, Ε_eff2Is the effective dielectric constant of each groove.
[0041]
Here, the characteristic impedance, length, and phase constant of the groove side groove are expressed as Z_O1, L₁, Β₁And the characteristic impedance, length, and phase constant of the groove short-circuit side groove are Z_O2, L₂, Β₂And When the distance from the open end of the groove to the short-circuit end (groove depth) is L (total), L (total) = L₁+ L₂ It becomes. Under the above conditions, the impedance Z of the open end of the groove can be expressed by the following equation (3).
[0042]
[Equation 3]

However, K = Z_O2/ Z_O1
[0043]
In this embodiment, the characteristic impedance is Z_O2 ≠ Z_O1 Therefore, in the equation (3), the value of the characteristic impedance ratio K is K ≠ 1. In order to make the impedance Z at the opening end of the groove infinite, the denominator of the equation (3) only needs to be zero, so 1 = K tan β₁L₁・ Tanβ₂L₂ Should be satisfied. Therefore, K₁, K₂The value of a is₁, A₂, A₃, A₄ And b₁, B₂, B₃, B₄These can be set arbitrarily by adjusting₁, K₂By setting appropriately, it is possible to give a sealing effect to two types of frequencies of 2.45 GHz and 5.8 GHz with one groove.
[0044]
That is, the groove depth (L₃+ L₄) And 2.45 GHz groove depth (L₁+ L₂And the characteristic impedance ratio K are determined so as to be the same. For example, the characteristic impedance ratio K for 2.45 GHz₁The groove depth (L₁+ L₂) And the characteristic impedance ratio K to 5.8 GHz so as to match₂Determine the value of. For example, if the thickness of the door is about 20 mm, K₁> 1, K₂By using the combination <1, it is possible to configure a radio wave leakage prevention groove that effectively acts on two types of high frequencies of 2.45 GHz and 5.8 GHz.
[0045]
As described above, in the configuration of the choke according to the present embodiment, one or more grooves are provided in at least one of the portions where the heating chamber main body 77 and the open / close door 75 face each other, and at least one wall surface of the groove It is composed of a group of conductor pieces that are arranged continuously at intervals in the longitudinal direction and parallel to the wall surface of the groove, and the conductor pieces are arranged so that the groove width periodically changes to form a conductive line, and the groove By changing at least one of the dielectric constant, the conductive line width, and the groove width and periodically changing the ratio of the characteristic impedance of the groove opening and the characteristic impedance of the short-circuited end of the groove. It becomes possible to simultaneously shield the two high frequencies.
[0046]
In the configuration of the high-frequency heating device described above, as shown in FIG. The electromagnetic wave supplied to the heating chamber 11 by forcibly driving the stirrer blade 93 may be forcibly stirred so that more uniform heating can be achieved.
[0047]
In addition, as shown in a schematic cross-sectional view of the high-frequency heating device in FIG. 7, a turntable 95 rotatably supported on the bottom surface of the heating chamber 11 may be provided to achieve uniform heating. In this case, the first high-frequency generator 13 is disposed on the upper side of the heating chamber 11 together with the second high-frequency generator 15, and a high frequency is introduced into the heating chamber 11 from the vicinity of the upper feeding port 33 of the second high-frequency generator 15. It is good also as a structure to supply (refer Fig.7 (a)), and it is good also as a structure which provides the 1st high frequency generation part 13 in the side surface of the heating chamber 11, and supplies a high frequency into the heating chamber 11 from a side surface (FIG. 7). (See (b)).
[0048]
Next, the operation of the high-frequency heating device 100 according to the present invention will be described.
When the object to be heated M is heat-treated using the high-frequency heating device 100 of the present invention, the heating chamber 11 has a high frequency of 2.45 GHz from the first high frequency generator 13 and a high frequency from the second high frequency generator 15. At least one of the high frequency of 5.8 GHz is supplied individually or simultaneously.
FIG. 8 shows an example of a standing wave state that appears in the heating chamber 11 as an example. (A) is a high frequency of 2.45 GHz, (b) is a high frequency of 5.8 GHz, and (c) is a combined high frequency of 2.45 GHz and 5.45 GHz.
[0049]
At a high frequency of 2.45 GHz shown in FIG. 8A, the distance between the antinodes of the electric field where the amount of heating increases (distance between the heating spots) is about 6 cm. For example, for an object to be heated M having a length of 30 cm. As a result, the antinodes of the standing wave can include only about 5 points on the straight line. Therefore, in the object to be heated M, there is a large difference in temperature rise characteristics between the heating spot position and other positions, and heating unevenness is likely to occur.
On the other hand, at a high frequency of 5.8 GHz shown in FIG. 8B, the interval between the heating spots is about 2.6 cm, and the heating object M can include 10 or more heating spots on a straight line with the above length. For this reason, the to-be-heated object M is heated uniformly, and the heating nonuniformity by the place of the to-be-heated object M becomes difficult to arise.
[0050]
However, at a high frequency of 5.8 GHz, the absorption depth with respect to the object to be heated M tends to be shallow, and the high frequency of 2.45 GHz is about 5 to 7 cm from the surface of the object to be heated M, whereas 5.8 GHz. At a high frequency, the depth becomes as shallow as about 2 to 3 cm from the surface. Accordingly, when heating the object to be heated M using only a high frequency of 5.8 GHz, the object to be heated M may be thin, but in the case of being thick, the inside and surface of the object to be heated M The temperature difference between the two becomes large, and uneven heating tends to occur.
[0051]
Therefore, as shown in FIG. 8C, by supplying a high frequency of 2.45 GHz and a high frequency of 5.8 GHz at the same time, even when the object to be heated M is thick, heating unevenness is reduced and uniform heating is performed. It can be realized. That is, when the high frequency of 2.45 GHz and the high frequency of 5.8 GHz overlap, the heating effect is obtained by increasing the bias even in the standing wave valley where the heating amount is small, thereby equalizing the high-frequency heating effect. Therefore, uniform heating independent of the location and thickness of the object to be heated M can be realized.
[0052]
Table 1 summarizes the differences between the characteristics of each of the above high frequencies and the heating effect.
[Table 1]

[0053]
Regarding the heating distribution characteristics of the object to be heated M, a high frequency of 5.8 GHz can be suitably used for heating a pizza or meat sliced product having a large surface area, and the occurrence of uneven heating can be suppressed, but a high frequency of 2.45 GHz. Is less likely to cause uneven heating due to the small number of heating points described above. However, by combining with a high frequency of 5.8 GHz, uniform heating can be realized even for thin products. Further, a high frequency of 2.45 GHz is more advantageous for a thick object to be heated, and at a high frequency of 5.8 GHz, heat does not pass to the inside of the object to be heated, and heating by heat conduction from the surface is performed. The heating time tends to take a long time, but by combining with the high frequency of 2.45 GHz, the inside of the object to be heated can be quickly heated.
Even when the high frequency of 2.45 GHz and the high frequency of 5.8 GHz are alternately switched and supplied, substantially the same effect as described above can be obtained.
As described above, various types of standing wave distribution can be formed by using high frequencies of different frequencies and adjusting the power distribution of each, realizing even less heating and even local heat treatment. it can.
[0054]
Next, a second embodiment of the high-frequency heating device according to the present invention will be described.
FIG. 9 shows a conceptual cross-sectional configuration diagram of the high-frequency heating device of the present embodiment. In addition, the description which abbreviate | omits the description is abbreviate | omitted by providing the same code | symbol with respect to the member which has the same function as the structure of 1st Embodiment mentioned above.
As shown in FIG. 9, the high-frequency heating device 200 of the present embodiment supplies a high frequency of 2.45 GHz from the first high frequency generator 13 from the lower side of the heating chamber 11, and the second high frequency from the upper side of the heating chamber 11. A partition plate configured to supply a high frequency of 5.8 GHz from the generation unit 15 and to divide the space of the heating chamber 11 up and down at a distance h from the upper surface of the heating chamber 11 with respect to the total height H of the heating chamber 11. 97 is provided.
The partition plate 97 can be easily attached to and detached from the heating chamber 11 at a plurality of height positions, and is supported and attached to a locking portion 99 formed on the wall surface of the heating chamber 11. As shown in the cross-sectional view of the partition plate in FIG. 10, the partition plate 97 includes a metal plate 101 that serves as a placement surface for an object to be heated, and a high-frequency heating element that is disposed opposite to or in contact with the metal plate 101. 103 and a fixing member 105 that fixes the high-frequency heating element 103 to the metal plate 101 and engages with the locking portion 99 on the heating chamber 11 side.
[0055]
The metal plate 101 is made of an aluminum-plated steel plate, and the surface of the metal plate 101 is provided with wavy irregularities by forming irregularities using the metal plate 101 itself as a waveform, or by forming convex portions on the metal plate 101. In addition, the front side surface of the aluminized steel sheet is subjected to fluorine coating with high antifouling effect, and the back side surface is subjected to black heat resistant coating with high heat absorption effect.
The high-frequency heating element 103 is formed on the surface opposite to the metal plate 101 side by adhering a high-frequency heating film 103a made of nitride and boride that generates heat by absorbing high frequency to the base 103b. The substrate 103b is made of a ceramic material or a heat-resistant resin material, and a material having a high heat storage effect is preferably used.
The fixing member 105 is made of an insulator provided on both sides along the direction in which the partition plate 97 is inserted into the heating chamber 11, and forms a gap between the fixing chamber 105 and the heating chamber 11, thereby sparking during high-frequency heating. Is prevented.
[0056]
Further, by making the metal plate 101 corrugated, the distance between the high-frequency absorption film 103a and the metal plate 101 is increased, thereby increasing the electric field strength on the high-frequency absorption film 103a, and the high-frequency absorption film 103a. An effect of increasing the calorific value is also obtained. In addition to the configuration in which the high-frequency heating film 103a is provided on the back surface, the high-frequency heating element 103 may be formed of a ceramic that generates heat at a high frequency.
[0057]
As the metal plate 101, a metal aluminized steel plate is used. However, if the surface reflects high frequency, a ceramic base material provided with a high frequency reflection layer by metal plating, metal deposition, or the like is also available. Furthermore, stainless steel, aluminum and aluminum alloys, galvanized steel sheets, various plated steel sheets such as aluminum zinc alloy plated steel sheets and copper plated steel sheets, cold rolled steel sheets, clad materials and the like can also be used. Further, although nitride or boride is used as the high-frequency absorption film 81, metal oxides such as tin oxide and indium oxide, composite oxides, and the like can also be used.
[0058]
According to the high-frequency heating device 200 configured as described above, the heating chamber 11 is divided into an upper space and a lower space, and a desired heat treatment can be performed in each space.
That is, in the high-frequency heating device 200, a high frequency of 5.8 GHz is supplied from the second high frequency generator 15 to the upper space 11 a of the heating chamber 11, and the first high frequency generator is supplied to the lower space 11 b of the heating chamber 11. A high frequency of 2.45 GHz from 13 is supplied. The object to be heated M placed on the partition plate 97 in the upper space 11a is heated by the high frequency of 5.8 GHz supplied from the upper side, and the high frequency heating element by the high frequency of 2.45 GHz supplied from the lower side. It is also heated by the heat generated by 103. In this case, so-called grill cooking is performed in the upper space 11a. On the other hand, in the lower space 11 b, the object to be heated M is placed on the bottom surface of the heating chamber 11, so that high-frequency heating of 2.45 GHz is performed.
[0059]
In addition, it is good also as a structure which does not provide the high frequency heat generating body 103 in said partition plate 97. FIG. In that case, in the upper space, heating by the high frequency from the lower side can be limited, and the object to be heated M can be heat treated mainly by the high frequency heating from the upper side.
[0060]
Further, the high frequency supplied from the upper side may be set to 5.8 GHz, and the high frequency supplied from the lower side may be set to 2.45 GHz.
[0061]
According to the above configuration, in addition to supplying the high frequency of each frequency described above to the common heating chamber 11, the individual heating spaces 11 a and 11 b are formed, and each frequency 11 a and 11 b individually has each frequency. High-frequency heating can be performed. As a result, a space more than necessary with respect to the size of the object to be heated M is prepared, and the heating energy is not supplied more than necessary. Heating is possible.
[0062]
In addition, it is good also as a structure which replaces with the removable partition plate 97 and uses a fixed partition structure, and forms the separate heating space by the high frequency of each frequency. In this case, the attaching / detaching operation of the partition plate 97 becomes unnecessary, and the heating operation can be simplified.
[0063]
Here, a configuration example in which the configuration of the high-frequency drive unit 17 of the high-frequency heating device 100 is simplified will be described.
As shown in FIG. 2, the high-frequency drive unit 17 was provided with an inverter circuit for individually driving the

magnetrons

25 and 31. However, as shown in another configuration example of the high-frequency drive unit shown in FIG. It is good also as a structure driven by one inverter circuit. That is, a drive control unit 111 that is connected to the inverter circuit 107 and controls the changeover switch 109 for switching the magnetron to be driven is provided, and the changeover switch 109 is appropriately set based on a signal from the control unit 19 (see FIG. 1). By performing switching control at an appropriate timing, a high frequency of 2.8 GHz and a high frequency of 2.45 GHz can be output alternately.
[0064]
According to the high frequency drive unit 18 configured as described above, two different types of

magnetrons

25 and 31 can be driven by a single inverter circuit, so that the circuit configuration of the high frequency drive unit 18 can be greatly simplified, The installation space to be used is small, which can contribute to the reduction in size and weight of the apparatus.
[0065]
Next, drive control of the first high frequency generator 13 and the second high frequency generator 15 will be described.
The control unit 19 (see FIG. 1) distributes the power from the power source to the 2.45 GHz magnetron 25 which is the first high frequency generation unit 13 and the 5.8 GHz magnetron 31 which is the second high frequency generation unit 15. The signal is output to the drive control unit 73 (see FIG. 2), and the drive control unit 73 receives this distribution signal and distributes power to the first inverter circuit 37 and the second inverter circuit 67.
[0066]
The power supply pattern to the 1st high frequency generation part 13 and the 2nd high frequency generation part 15 at this time is demonstrated using FIGS. 12-15.
FIG. 12 shows a pattern for alternately outputting high frequencies of 5.8 GHz and 2.45 GHz. According to this power feeding pattern, output is performed alternately and both high frequencies are not output at the same time. Therefore, each high frequency output can be applied up to the rated power of the high frequency heating device and output. Therefore, it is possible to efficiently heat the object to be heated with each high-frequency generator being set to the maximum output.
[0067]
FIG. 13 shows a pattern for simultaneously outputting high frequencies of 5.8 GHz and 2.45 GHz. The output at this time is controlled so that the total power of both high frequencies does not exceed the rated power of the high frequency heating device. In the figure, when the rated power is P, for example, both high-frequency powers are set to P / 2. The power distribution ratio can be set to an arbitrary ratio other than this, and for example, the power distribution ratio can be changed after a predetermined time has elapsed.
[0068]
FIG. 14 shows a pattern in which a high frequency of 2.45 GHz is output first and a high frequency of 5.8 GHz is output later. According to this pattern, at the initial stage of heating when the temperature of the object to be heated is low, a high frequency of 2.45 GHz, which has a relatively high heating effect, is supplied to raise the temperature of the object to be heated at a stretch, By supplying a high frequency of 5.8 GHz after reaching, the heating temperature can be made uniform and a uniform heating state with a small temperature distribution can be achieved. On the contrary, a pattern in which a high frequency of 5.8 GHz is output first and a high frequency of 2.45 GHz is output later may be used. In this case, it is suitable for cooking that heats strongly in the second half of heating. In addition, when outputting each high frequency of the latter half of heating simultaneously, you may make it the pattern which outputs each high frequency alternately as shown in FIG. In that case, each output can be applied up to the maximum output.
[0069]
FIG. 15 shows a pattern for outputting only a high frequency of 5.8 GHz. This pattern is particularly suitable for heating a thin object to be heated, and can be finished in a state where the temperature distribution is small. Moreover, it is good also as a pattern which outputs only the high frequency of 2.45 GHz. In this case, the same high frequency heating as before can be performed.
[0070]
【The invention's effect】
As described above in detail, the high-frequency heating device according to the present invention is a high-frequency heating device that supplies a high frequency from a high-frequency generating unit to a heating chamber that houses a heated object, and heats the heated object. The high frequency generator includes a first high frequency generator that generates a high frequency of 2.45 GHz, and a second high frequency generator that generates a high frequency of 5.8 GHz, so that a high heating effect frequency can be obtained. Two types of high frequency, a high frequency of 2.45 GHz and a high frequency with a uniform heating distribution of 5.8 GHz, can be supplied to the heating chamber, and the occurrence of heating unevenness can be suppressed, and a thick object to be heated Even so, uniform heat treatment can be performed quickly.
Moreover, according to the control method of the high-frequency heating device according to the present invention, a high heating effect is achieved by supplying a high frequency of 2.45 GHz and a high frequency of 5.8 GHz to the heating chamber simultaneously or alternately. Since a high frequency of 2.45 GHz and a high frequency of 5.8 GHz having a high uniform heating effect can be selectively supplied, efficient heating is performed by supplying an appropriate high frequency according to the shape of the object to be heated and the heating purpose. Processing can be performed.
[Brief description of the drawings]
FIG. 1 is a conceptual configuration diagram of a high-frequency heating device according to the present invention.
FIG. 2 is a configuration diagram of a high-frequency driving unit of the high-frequency heating device.
FIG. 3 is an external perspective view of a high-frequency heating device for explaining a choke for preventing radio wave leakage.
4 is a cross-sectional view showing an AA cross section (a) and a BB cross section (b) in FIG. 3;
FIG. 5 is a perspective view of a choke.
FIG. 6 is a partial schematic cross-sectional view of a high-frequency heating device for explaining a stirrer blade.
FIGS. 7A and 7B are schematic cross-sectional views of a high-frequency heating device, in which FIG. 7A is an explanatory diagram showing high-frequency upper power feeding of 2.45 GHz, and FIG.
8A is a high frequency of 2.45 GHz, FIG. 8B is a high frequency of 5.8 GHz, and FIG. 8C is a high frequency of 2.45 GHz and 5.45 GHz in a standing wave state appearing in the heating chamber. It is explanatory drawing which shows this multiplexing.
FIG. 9 is a conceptual cross-sectional configuration diagram of a frequency heating apparatus in which a heating chamber is divided into upper and lower portions by a partition plate.
FIG. 10 is a cross-sectional view of a partition plate.
FIG. 11 is a configuration diagram illustrating another configuration example of the high-frequency drive unit.
FIG. 12 is an explanatory diagram showing a pattern of feeding power to the first high frequency generator and the second high frequency generator and alternately outputting high frequencies of 5.8 GHz and 2.45 GHz.
FIG. 13 is an explanatory diagram showing a power feeding pattern to the first high frequency generating unit and the second high frequency generating unit and a pattern for simultaneously outputting high frequencies of 5.8 GHz and 2.45 GHz.
FIG. 14 is an explanatory diagram showing a pattern of feeding power to the first high-frequency generator and the second high-frequency generator, in which a high frequency of 2.45 GHz is output first and a high frequency of 5.8 GHz is output later. is there.
FIG. 15 is an explanatory diagram showing a power feeding pattern to the first high frequency generator and the second high frequency generator and outputting only a high frequency of 5.8 GHz.
[Explanation of symbols]
11 Heating chamber
13 First high frequency generator
15 Second high frequency generator
17 High frequency drive
19 Control unit
25 Magnetron (for 2.45 GHz)
27 Lower power inlet
29 Lower waveguide
31 Magnetron (for 5.8 GHz)
33 Upper power supply port
35 Upper waveguide
37 First inverter circuit
67 Second inverter circuit
73 Drive control unit
75 Opening door
77 Heating chamber body
79 chalk
81 Conductor piece
83 Metal plate
85 groove
97 divider
100, 200 high frequency heating device
109 changeover switch
111 Drive controller
M Object to be heated

Claims

被加熱物を収容する加熱室に高周波発生部から高周波を供給し、被加熱物を加熱処理する高周波加熱装置であって、
前記高周波発生部が、周波数が２．４５ＧＨｚの高周波を発生する第１高周波発生部と、周波数が５．８ＧＨｚの高周波を発生する第２高周波発生部とを備えた高周波加熱装置。A high frequency heating apparatus that supplies a high frequency from a high frequency generator to a heating chamber that houses an object to be heated, and heats the object to be heated,
A high-frequency heating apparatus, wherein the high-frequency generator includes a first high-frequency generator that generates a high frequency of 2.45 GHz and a second high-frequency generator that generates a high frequency of 5.8 GHz.

前記第１高周波発生部へ駆動電力を供給する第１インバータ回路と、
前記第２高周波発生部へ駆動電力を供給する第２インバータ回路と、
これらインバータ回路により前記第１高周波発生部と前記第２高周波発生部とを同時に又は交互に駆動する駆動制御部とを備えた請求項１記載の高周波加熱装置。A first inverter circuit for supplying driving power to the first high frequency generator;
A second inverter circuit for supplying driving power to the second high frequency generator;
The high frequency heating apparatus according to claim 1, further comprising: a drive control unit that drives the first high frequency generator and the second high frequency generator simultaneously or alternately by the inverter circuit.

前記第１高周波発生部及び第２高周波発生部へ駆動電力を供給する単一のインバータ回路と、
前記第１高周波発生部と前記第２高周波発生部への給電を交互に切り替えて駆動する駆動制御部とを備えた請求項１記載の高周波加熱装置。A single inverter circuit for supplying driving power to the first high frequency generator and the second high frequency generator;
The high-frequency heating device according to claim 1, further comprising a drive control unit that is driven by alternately switching power feeding to the first high-frequency generation unit and the second high-frequency generation unit.

前記加熱室の上面に設けられ高周波を前記加熱室内に導入する上側給電口と、前記加熱室の下面に設けられ高周波を前記加熱室内に導入する下側給電口とを備え、該上側給電口と下側給電口のそれぞれから前記第１高周波発生部又は前記第２高周波発生部からの高周波を個別に導入する請求項１〜請求項３のいずれか１項記載の高周波加熱装置。An upper power supply port provided on the upper surface of the heating chamber for introducing a high frequency into the heating chamber; and a lower power supply port provided on a lower surface of the heating chamber for introducing a high frequency into the heating chamber; The high frequency heating device according to any one of claims 1 to 3, wherein a high frequency from the first high frequency generation unit or the second high frequency generation unit is individually introduced from each of the lower power supply ports.

前記加熱室の空間を上下に分割する仕切板を設けた請求項４記載の高周波加熱装置。The high frequency heating apparatus according to claim 4, further comprising a partition plate that divides the space of the heating chamber into upper and lower portions.

前記仕切板が高周波発熱体を備え、高周波の照射により発熱する請求項５記載の高周波加熱装置。The high frequency heating apparatus according to claim 5, wherein the partition plate includes a high frequency heating element, and generates heat when irradiated with high frequency.

前記加熱室の上側給電口から前記第２高周波発生部からの高周波を前記加熱室内に導入する請求項４〜請求項６のいずれか１項記載の高周波加熱装置。The high frequency heating apparatus according to any one of claims 4 to 6, wherein a high frequency from the second high frequency generator is introduced into the heating chamber from an upper power feeding port of the heating chamber.

前記加熱室が、開口部を有する加熱室本体と、該開口部を開閉自在に覆う開閉扉とを有し、前記加熱室本体と前記開閉扉とが対向する部分の少なくとも一方に、電波洩れ防止用のチョークが形成され、
該チョークが前記第１高周波発生部と前記第２高周波発生部からの各高周波を遮蔽するものである請求項１〜請求項７のいずれか１項記載の高周波加熱装置。The heating chamber has a heating chamber body having an opening and an opening / closing door that covers the opening so as to be openable / closable, and at least one of the portions where the heating chamber body and the opening / closing door face each other prevents radio wave leakage. A choke is formed,
The high-frequency heating device according to any one of claims 1 to 7, wherein the choke shields each high-frequency from the first high-frequency generator and the second high-frequency generator.

被加熱物を収容する加熱室に高周波発生部から高周波を供給し、被加熱物を加熱処理する高周波加熱装置の制御方法であって、
前記高周波発生部から、周波数が２．４５ＧＨｚの高周波と周波数が５．８ＧＨｚの高周波とを同時に又は交互に前記加熱室に供給する高周波加熱装置の制御方法。A method of controlling a high-frequency heating apparatus that supplies a high frequency from a high-frequency generator to a heating chamber that houses a heated object, and heats the heated object,
A control method for a high-frequency heating device that supplies a high-frequency with a frequency of 2.45 GHz and a high-frequency with a frequency of 5.8 GHz simultaneously or alternately from the high-frequency generator to the heating chamber.

前記各周波数のうち、いずれか一方の高周波を加熱初期に出力し、加熱開始から所定時間経過後又は所定温度到達後にいずれか他方の高周波の出力を開始する請求項９記載の高周波加熱装置の制御方法。The control of the high frequency heating apparatus according to claim 9, wherein one of the frequencies is output at the initial stage of heating, and the output of the other high frequency is started after a predetermined time has elapsed or a predetermined temperature has been reached since the start of heating. Method.

前記各周波数を同時に出力する場合に、各高周波の出力を、高周波出力のための駆動電力の合計が高周波加熱装置の定格電力を超えないように少なくともいずれか一方の出力を制限する請求項９又は請求項１０記載の高周波加熱装置の制御方法。10. When outputting each frequency simultaneously, at least one of the outputs of each high frequency is limited so that the total driving power for the high frequency output does not exceed the rated power of the high frequency heating device. The control method of the high frequency heating apparatus of Claim 10.