JPS58194290A - High frequency heater - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【発明の詳細な説明】 本［１１Ｎは高周波エネルギーによって食品などの被加
熱物を加熱処理する高周波加熱装置に係り。DETAILED DESCRIPTION OF THE INVENTION This [11N] relates to a high-frequency heating device that heats objects to be heated, such as foods, using high-frequency energy.

特に電波漏洩防止用の周期構造体付きのドアの改Ｐ 良に関するものである。Especially for doors with periodic structures to prevent radio wave leakage. It is about good.

従来、ドア周縁に設けたチョ〜り溝の電波漏洩防止効果
を増すため、チョーク溝の内部に周期構造体を取付けた
り、チョーク溝の周壁自体を多数の金属片から成る周期
構造体で形成したものが多数提案されているが、実用化
されたものは少ない。Conventionally, in order to increase the effect of preventing radio wave leakage in the choke groove provided around the door periphery, a periodic structure was attached inside the choke groove, or the circumferential wall of the choke groove itself was formed with a periodic structure made of a large number of metal pieces. Many things have been proposed, but few have been put into practical use.

実用化されたものは、加熱周波ａ２．４５０　ＭＨｚで
、その自由空間波長λ０（１２２ｍ）の約τの深さの基
本波用チョーク溝を加熱室の開口部周縁（前面フランジ
面）に対して直角方向に設けているため、ドアが厚く、
電波シールに要するスペースが大形きなり。The one that has been put into practical use has a heating frequency of 2.450 MHz, and a choke groove for the fundamental wave with a depth of approximately τ of the free space wavelength λ0 (122 m) is placed around the periphery of the opening of the heating chamber (front flange surface). Because it is installed at right angles, the door is thicker.
The space required for radio wave stickers is large.

装置全体も大形となっていた。基本波に対する電波シー
ルのみ行っているので、高周波に対するシール用に電波
吸収材を追加しているものも見られる。さらに１周期構
造体付近に電磁界を集中させるため、空焼時におけるド
アと加熱室開口部周縁との接触部での異常加熱やスノ（
−りの発生を助長し易いなどの欠点を有してｔｎた。The entire device was also large. Since radio wave sealing is performed only for fundamental waves, some products add radio wave absorbing material to seal against high frequencies. Furthermore, in order to concentrate the electromagnetic field near the one-period structure, abnormal heating and sagging at the contact area between the door and the periphery of the opening of the heating chamber during dry firing can be
However, it has disadvantages such as the tendency to promote the occurrence of corrosion.

そこで９本発明は上記の点に鑑み、外形寸法が小さくで
き、かつ、上記異常加熱やス）Ｚ−りが発３　Ｐ 生しにぐい周期構造体付きのドアを備えた高周波加熱装
置を提供することを目的とする。Therefore, in view of the above points, the present invention provides a high-frequency heating device that has a door with a periodic structure that can reduce the external dimensions and prevents the above-mentioned abnormal heating and scratches. The purpose is to

次に本発明の一実施例を図面とともに説明する。Next, one embodiment of the present invention will be described with reference to the drawings.

、１第１図は本発明の高周波加熱装置の一実施例を示す
要部斜視図である。１は高周波エネルギーを発生する高
周波発振器、２は高周波発振器１と加熱室３とを連結す
る導波管である。４は加熱室３開口部前面如設けたフラ
ンジで、このフランジ４にはドア５に設けたラッチ５ａ
、５ｂが貫通するラッチ挿入口４ａ、４ｂがおいている
。ランチ５ａ、５ｂは高周波発振器１のオン・オフを制
御すると共にドア５の密閉状態を保持する。５ｃはドア
５を閉じたときにフランジ４に平面接触するドア後板で
、金属板から成る。５ｄは透明板と金網あるいは穴あき
金属板から成る響き窓である。５ｅは、第２図のように
ドア５周縁部に設けた電波減衰空胴６の入ロアや周期構
造体８をカバーする誘電体カバーである。, 1 FIG. 1 is a perspective view of essential parts showing an embodiment of the high-frequency heating device of the present invention. 1 is a high frequency oscillator that generates high frequency energy; 2 is a waveguide that connects the high frequency oscillator 1 and the heating chamber 3; 4 is a flange provided on the front side of the opening of the heating chamber 3, and this flange 4 has a latch 5a provided on the door 5.
, 5b are provided with latch insertion openings 4a and 4b. The launches 5a and 5b control the on/off of the high frequency oscillator 1 and keep the door 5 in a sealed state. Reference numeral 5c denotes a door rear plate that makes plane contact with the flange 4 when the door 5 is closed, and is made of a metal plate. 5d is a sounding window made of a transparent plate and a wire mesh or perforated metal plate. Reference numeral 5e denotes a dielectric cover that covers the lower entrance of the radio wave attenuation cavity 6 and the periodic structure 8 provided at the peripheral edge of the door 5 as shown in FIG.

第２図は第１図におけるドア５とフランジ４との平面接
触部の断面拡大図である。ドア５周縁において基本波用
チョーク溝９と第２高調波用チョ一り溝１０とを対向さ
せ一つの入ロアを持つ一つの電波減衰空胴６を構成して
いる。基本波用チョーク溝９では入ロアから短絡面まで
の矢印で示し六電波伝搬経路９ａを加熱周波数の自由空
間波長λｏＫ対λ０ して約τとしている。基本波用チョーク溝９を加熱室３
に近い側に配置すると共忙、この溝９の一壁面であるド
ア後板５ｃをフランジ４と平面接触（第２図ではわかり
やすくするため故意に隙間を開ばて図示している。）さ
せている。第２高調波用チヨーク溝１０では入ロアから
短絡面までの矢印で示しに電波伝搬経路ｆＱａを約智と
している。第２高調波用チヨーク溝１０の７ランジ４と
対向する一壁面自体を根本８ａの幅が先端８ｂの幅より
も大きい台形状とする複数の金属片から成る波板８（周
期構造体）に分割している（第３図参照）。この波板８
は、加熱室３から７ランジ４とドア後板５Ｃとの隙間を
通過した電波が点線上矢印１１のようにそのまま外部に
漏洩するのを防ぎ、電波減衰空胴６の基本波用チョーク
溝９あるいは第２高調波用チヨーク溝１０内へ能率よく
導かれる整合素子とじて　Ｐ 作用させるもので、根本８ａから先端８ｂまでの長さは
実験によると釣部がよい。波板８の先端８ｂには電波減
衰空胴６の内部に向かって折り曲げた突出面１２を設け
、この突出面１２とほぼ平行にドア後板５Ｃの端部にも
突出面１３を設け１両突出面１２゜１６の間の間隙を７
ランジ４に直角な電波伝搬経路とすることにより、基本
波用チョーク溝９および第２高調波用チヨーク溝１０を
共にフランジ４尾対して直角な方向と平行な方向から成
る電波伝搬経路９ａ、　１０ａとしている。前述のよう
に両チョーク溝９．１０の電波伝搬経路９ａ、　１０ａ
をそれぞれ約層約贅としており、かつフランジ４に対し
て直角な方向と平行な方向とに屈曲させている。したが
って、フランジ４と直角方向のドア５の厚みに対応する
Ａ寸法、８寸法および電波減衰空胴６の７ランジ４と平
行な方向の寸法Ｃを小さくすることができる。FIG. 2 is an enlarged cross-sectional view of the planar contact portion between the door 5 and the flange 4 in FIG. 1. At the periphery of the door 5, a fundamental wave choke groove 9 and a second harmonic wave choke groove 10 are opposed to form one radio wave attenuation cavity 6 having one input lower. In the fundamental wave choke groove 9, the six radio wave propagation paths 9a shown by arrows from the input lower to the short-circuit surface are approximately τ, which is the free space wavelength λoK of the heating frequency versus λ0. The fundamental wave choke groove 9 is connected to the heating chamber 3.
When placed on the side closer to the groove 9, the door rear plate 5c, which is one wall surface of the groove 9, is brought into plane contact with the flange 4 (in Fig. 2, a gap is intentionally left open for clarity). ing. In the second harmonic cheese yoke groove 10, the radio wave propagation path fQa is approximately defined by the arrow from the input lower part to the short-circuit surface. A corrugated plate 8 (periodic structure) consisting of a plurality of metal pieces is formed such that one wall surface of the second harmonic chiyoke groove 10 facing the 7 flange 4 has a trapezoidal shape in which the width of the base 8a is larger than the width of the tip 8b. It is divided (see Figure 3). This corrugated plate 8
prevents the radio waves passing through the gap between the heating chamber 3 to 7 langes 4 and the door rear plate 5C from leaking to the outside as indicated by the arrow 11 above the dotted line, and the fundamental wave choke groove 9 of the radio wave attenuation cavity 6 Alternatively, P is applied as a matching element that is efficiently guided into the second harmonic chiyoke groove 10, and experiments have shown that the length from the root 8a to the tip 8b is preferably a fishing part. A protruding surface 12 bent toward the inside of the radio wave attenuation cavity 6 is provided at the tip 8b of the corrugated plate 8, and a protruding surface 13 is also provided at the end of the door rear plate 5C approximately parallel to this protruding surface 12. The gap between the protruding surfaces 12° and 16 is 7
By making the radio wave propagation path perpendicular to the flange 4, the fundamental wave choke groove 9 and the second harmonic choke groove 10 both form radio wave propagation paths 9a and 10a that are perpendicular to and parallel to the flange 4. It is said that As mentioned above, the radio wave propagation paths 9a and 10a of both choke grooves 9 and 10
, and are bent in a direction perpendicular to the flange 4 and in a direction parallel to the flange 4. Therefore, dimensions A and 8 corresponding to the thickness of the door 5 in the direction perpendicular to the flange 4 and dimension C of the radio wave attenuation cavity 6 in the direction parallel to the flange 4 can be reduced.

例えば、加熱周波数２．４５０ＭＨ２（波長λ６　＝　
１２２＋ｏ＋）の高周波加熱装置において９本実施例の
構成のト。For example, heating frequency 2.450MH2 (wavelength λ6 =
122+o+) high frequency heating device with the configuration of this embodiment.

アではＡが１３ｔｍ＊　Ｂが１６ｗｍ、Ｃが４０電程度
で十分実　Ｐ 用に供せられることが実験で確認されており、電波漏洩
防止に要するドア５周縁部の空胴体積を極めて小さく抑
えることができる。Experiments have confirmed that 13tm for A, 16wm for B, and 40 tm for C are sufficient for practical use, and the void volume around the door 5 required to prevent radio wave leakage can be kept extremely small. be able to.

そのｋめ１本実施例では、ドア５の外形寸法を小形化、
薄形化することができ、装置全体の外形寸法に対する加
熱室３の体積比率（スペースファクター）の良好な高周
波加熱装置が提供できる。In this first embodiment, the outer dimensions of the door 5 are made smaller.
It is possible to provide a high-frequency heating device that can be made thin and has a good volume ratio (space factor) of the heating chamber 3 to the external dimensions of the entire device.

これは、ビルトイン式、その他置き場所が狭い場合に都
合がよく、電子化された薄形のコントロールパネル等に
も適応しており、デザイン的にも有利である。もちろん
材料が少なくて済むので、コスト的にも有利である。第
３図に示すように、波板８の先端８ｂを折り曲げて突出
面１２を設け、この突出面１２とドア後板５Ｃの端部の
突出面１３とをほぼ平行にして平面どうしを向かい合わ
せている。This is convenient for built-in types and other cases where space is limited, and it is also suitable for thin electronic control panels, which is advantageous in terms of design. Of course, since less material is required, it is also advantageous in terms of cost. As shown in FIG. 3, a protruding surface 12 is provided by bending the tip 8b of the corrugated plate 8, and the protruding surface 12 and the protruding surface 13 at the end of the door rear plate 5C are made almost parallel and the planes face each other. ing.

このため１両平面１２．１３間の電界は局部的に強くな
ら々い。したがって１本実施例の周期構造体付きのドア
５は、ドア後板５Ｃとフランジ４との接触部、特釦突出
面１５の湾曲部付近において空焼時に生じ易い高周波電
磁界による異常加熱やス・（−り７　Ｐ 等の不都合を低減する作用がある。Therefore, the electric field between the two planes 12 and 13 becomes locally strong. Therefore, the door 5 with the periodic structure according to the present embodiment prevents abnormal heating due to the high-frequency electromagnetic field that is likely to occur during dry firing in the contact area between the door rear plate 5C and the flange 4, and in the vicinity of the curved area of the special button protruding surface 15.・(-ri7P) It has the effect of reducing inconveniences such as.

また、波板８は根本８ａの幅を先端８ｂの幅よりも大き
い台形状としているため、波板８の強度が強く、変形に
よる電波漏洩防止効果の低下も防げる。Further, since the corrugated plate 8 has a trapezoidal shape in which the width of the base 8a is larger than the width of the tip 8b, the strength of the corrugated plate 8 is strong, and the deterioration of the radio wave leakage prevention effect due to deformation can be prevented.

さらに、第３図のようにラッチ５ａ、　５ｂおよびその
関連部品（囲路）を収納する断面Ｕ字状の金属板からな
るう°ツチ収納部品１４を電波減衰空胴６の外側に設け
、このラッチ収納部１４の入口１４ａをフランジ４と対
向させると共に第２高調波用チヨーク溝１０の一壁面と
している波板８と同形状の波板８１で覆っている。波板
８１は波板８とは反対向きで、根本８１ａが先端８１ｂ
よりも大きい台形状で。Further, as shown in FIG. 3, a hollow housing part 14 made of a metal plate with a U-shaped cross section is provided outside the radio wave attenuation cavity 6 to house the latches 5a, 5b and their related parts (enclosure). The entrance 14a of the latch storage portion 14 is opposed to the flange 4 and is covered with a corrugated plate 81 having the same shape as the corrugated plate 8 which forms one wall surface of the second harmonic chuck groove 10. The corrugated plate 81 is oriented in the opposite direction to the corrugated plate 8, with the root 81a being the tip 81b.
With a trapezoid shape larger than .

先端８１ｂ　Ｋはラッチ収納部１４の内部に向かって折
し曲げた突出面１２１が設けてあり、この突出面１２１
はラッチ収納部１４の側壁１４ｂと＃１ぼ平行になって
いる。波板８１はラッチ５ａ、　５ｂの突出部のみ除去
している。波板８のみドア５周綴金周に設けた場合の電
波漏洩量に対する波板８１をラッチ収納部１４の入口１
４＆に追加した場合の電波漏洩量の比率特開昭５８−１
９４２９０（３） は第４図のようになり、ドア後板５ｃと７ランジ４との
間隙が大きくなっても、波板８１を追加すると。The tip 81b K is provided with a protruding surface 121 that is bent toward the inside of the latch storage section 14.
#1 is approximately parallel to the side wall 14b of the latch storage portion 14. From the corrugated plate 81, only the protruding parts of the latches 5a and 5b are removed. The corrugated plate 81 is installed at the entrance 1 of the latch storage section 14 for the amount of radio wave leakage when only the corrugated plate 8 is provided around the door 5.
Ratio of radio wave leakage when added to 4 & JP-A-58-1
94290(3) is as shown in Fig. 4, even if the gap between the door rear plate 5c and the 7-lunge 4 becomes large, if the corrugated plate 81 is added.

電波漏洩量を小さく抑えられることが確認された。It has been confirmed that the amount of radio wave leakage can be kept small.

しながって、ドア５とフランジ４との接触面の平面度が
悪く、接触面に不規則な隙間があいた場合でも、波板８
１をラッチ収納部１４の入口１４ａに追加することによ
り電波漏洩量を小さく抑えることができる。このように
波板８１を追加しても、波板８１を追加しない場合とド
アの外形寸法は変らず。Therefore, even if the flatness of the contact surface between the door 5 and the flange 4 is poor and there is an irregular gap in the contact surface, the corrugated plate 8
1 at the entrance 14a of the latch storage section 14, the amount of radio wave leakage can be suppressed to a small level. Even if the corrugated plate 81 is added in this way, the external dimensions of the door remain the same as when the corrugated plate 81 is not added.

前述のスペースファクターの良好な高周波加熱装置を提
供できる等の効果も保持する。また、波板８１の先端８
１ｂはドア５の最外周壁（ラッチ収納部１４の側壁１４
ｂ）と平面どうしで対向しており、かつ電波減衰空胴６
を通過した微少電波しか到達しないので、高周波電磁界
によるスパークや異常加熱は発生しない。The above-mentioned effects such as being able to provide a high-frequency heating device with a good space factor are also maintained. In addition, the tip 8 of the corrugated plate 81
1b is the outermost peripheral wall of the door 5 (the side wall 14 of the latch storage section 14).
b) and the radio wave attenuating cavity 6 which faces each other with their planes facing each other.
Since only minute radio waves that have passed through reach the sensor, sparks and abnormal heating caused by high-frequency electromagnetic fields do not occur.

以トのように１本発明によると、簡単な構成により、外
形寸法が小さく、異常加熱やスパークが発生しに〈＜、
かつドアと加熱室開口部前面のフランジとの接触部の平
面度が悪い場合でも使用に　Ｐ 耐える周期構造体付きのドアを備えた高周波加熱装置を
提供することができる。As described above, according to the present invention, due to the simple structure, the external dimensions are small, and abnormal heating and sparks do not occur.
Moreover, it is possible to provide a high-frequency heating device including a door with a periodic structure that can withstand use even when the flatness of the contact portion between the door and the flange on the front surface of the heating chamber opening is poor.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の高周波加熱装置の一実施例を示す要部
斜視図、第２図は第１図におけるドア５と７ランジ４と
の平面接触部の断面拡大図、第６図は同誘電体カバー５
６を除去してドア３の内側を上方斜めから見た斜視図、
第４図は同ラッチ収納部１４の入口１４ａに波板８１を
追加した場合の電波漏洩防止効果を示すグラフである。 １・・・高周波発振器、３・・・加熱室、４・・・７ラ
ンジ。 ５・・・ドア、５ａ、５ｂ・・・ラッチ、６・・・電波
減衰空胴。 ７・・・電波減衰空胴６の入口、　８．８１・・・波板
。 ９・・・基本波用チョーク溝、１０・・・第２高調波用
チヨーク。 １４・・・ラッチ収納部、１４ａ・・・ラッチ収納部１
４の入口。 出願人　　日立熱器具株式会社 第１図　　　　。 第２図FIG. 1 is a perspective view of essential parts showing one embodiment of the high-frequency heating device of the present invention, FIG. 2 is an enlarged cross-sectional view of the planar contact portion between door 5 and 7 flange 4 in FIG. 1, and FIG. 6 is the same. Dielectric cover 5
A perspective view of the inside of the door 3 viewed diagonally from above with 6 removed;
FIG. 4 is a graph showing the effect of preventing radio wave leakage when a corrugated plate 81 is added to the entrance 14a of the latch storage section 14. 1...High frequency oscillator, 3...Heating chamber, 4...7 lunge. 5... Door, 5a, 5b... Latch, 6... Radio wave attenuation cavity. 7... Entrance of radio wave attenuation cavity 6, 8.81... Corrugated plate. 9... Choke groove for fundamental wave, 10... Choke groove for second harmonic. 14... Latch storage section, 14a... Latch storage section 1
4 entrance. Applicant: Hitachi Thermal Appliances Co., Ltd. Figure 1. Figure 2

Claims (1)

【特許請求の範囲】[Claims] 加熱室開口部を封止するドア周縁部に基本波用チョーク
溝と第２高調波用チヨーク溝とを互いに向かい合わせて
一つの入口を持つ一つの電波減衰空胴を構成し、かつ上
記第２高調波用チヨーク溝の加熱室開口部のフランジと
対向する壁面を複数の先端を折シ曲げた台形状金属片か
ら成る波板（８）で形成し、高周波発振器オン・オフを
制御するためとドアの密閉状態を保持するためのラッチ
を収納する断面Ｕ字状の金属板から成るラッチ収納部α
→を上記電波減衰空胴の外側に設け、このラッチ収納部
α荀の入口（１４ａ’）を加熱室開口部の７ランジと対
向させると共に、上記波板（８）と同形状の波板（８１
）で覆ったことを特徴とする高周波加熱装置。A choke groove for a fundamental wave and a choke groove for a second harmonic are faced to each other on a peripheral edge of a door that seals an opening of the heating chamber to form one radio wave attenuation cavity having one entrance, and the second The wall surface facing the flange of the heating chamber opening of the harmonic chiyoke groove is formed with a corrugated plate (8) consisting of a trapezoidal metal piece with multiple bent ends, and is used to control the on/off of the high frequency oscillator. Latch storage part α consisting of a metal plate with a U-shaped cross section that stores the latch for keeping the door sealed.
→ is provided on the outside of the radio wave attenuation cavity, and the entrance (14a') of this latch storage part α-1 is opposed to the 7 langes of the heating chamber opening, and a corrugated plate (8) having the same shape as the corrugated plate (8) 81
) A high-frequency heating device characterized by being covered with.