JP2021000201A

JP2021000201A - Cooker

Info

Publication number: JP2021000201A
Application number: JP2019114569A
Authority: JP
Inventors: 晋平長谷川; Shinpei Hasegawa; 光起福島; Mitsuki Fukushima; 片岡　利充; Toshimitsu Kataoka; 利充片岡
Original assignee: Zojirushi Corp
Current assignee: Zojirushi Corp
Priority date: 2019-06-20
Filing date: 2019-06-20
Publication date: 2021-01-07
Anticipated expiration: 2039-06-20
Also published as: JP7246261B2; TW202103618A; CN212996072U

Abstract

To improve heating property of a pot.SOLUTION: A cooker (a rice cooker 10) includes a housing part 22 housing a pot 15 and a plurality of coils 25A, 25B. The coils 25A, 25B are annular respectively and have: first parts 26 which are curved by first curvature radius r1 so that they protrude toward an axis line A of the housing part 22, and extend along a bottom wall 24a so that they cross the bottom wall 24a; second parts 27 which are curved by second curvature radius r2 smaller than the first curvature radius r1 and extend along an outer peripheral wall 24b; arc third parts 28 continued to first ends 26a of the first parts 26 and first ends 27a of the second parts 27; and arc fourth parts 29 continued to second ends 26b of the first parts 26 and second ends 27b of the second parts 27.SELECTED DRAWING: Figure 3

Description

本発明は、調理器に関する。 The present invention relates to a cooker.

特許文献１には、有底筒状の炊飯鍋の底に周方向へ間隔をあけて３個のコイルを配置した炊飯器が開示されている。この炊飯器では、３個のコイルのうち、１個が通電されて残りが遮断されるように、定められた順番で通電状態を切り換えながら、コイルによって炊飯鍋を誘導加熱する。 Patent Document 1 discloses a rice cooker in which three coils are arranged at intervals in the circumferential direction on the bottom of a bottomed tubular rice cooker. In this rice cooker, the rice cooker is induced and heated by the coils while switching the energized state in a predetermined order so that one of the three coils is energized and the rest is cut off.

特開２０１８−６１５７３号公報JP-A-2018-61573

特許文献１の加熱機器には、コイルへの通電状態の切り換えによって炊飯鍋の局部を集中加熱することは記載されているが、コイルによる炊飯鍋の加熱性について改善の余地がある。 Although it is described in the heating device of Patent Document 1 that the local part of the rice cooking pot is centrally heated by switching the energization state of the coil, there is room for improvement in the heating property of the rice cooking pot by the coil.

本発明は、複数のコイルを備える調理器における鍋の加熱性の向上を課題とする。 An object of the present invention is to improve the heatability of a pan in a cooker provided with a plurality of coils.

本発明の一態様は、底壁と、この底壁の外周から立ち上がった筒状の外周壁とを有し、有底筒状の鍋を収容する収容部と、前記収容部の外面側に前記収容部の軸線を中心として周方向に並べて配置された複数のコイルとを備え、前記複数のコイルはそれぞれ環状であり、前記収容部の軸線が延びる方向から前記収容部を見て、前記収容部の軸線に向けて突出するように第１曲率半径で湾曲し、前記底壁を横切るように前記底壁に沿って延びる第１部分と、前記第１曲率半径よりも小さい第２曲率半径で湾曲し、前記外周壁に沿って延びる第２部分と、前記収容部の周方向における前記第１部分の第１端と前記第２部分の第１端とに連なる円弧状の第３部分と、前記収容部の周方向における前記第１部分の第２端と前記第２部分の第２端とに連なる円弧状の第４部分とを有する、調理器を提供する。 One aspect of the present invention has a bottom wall, a tubular outer peripheral wall rising from the outer periphery of the bottom wall, a storage portion for accommodating a bottomed tubular pot, and the accommodating portion on the outer surface side of the accommodating portion. A plurality of coils arranged side by side in the circumferential direction about the axis of the accommodating portion are provided, and the plurality of coils are each annular, and the accommodating portion is viewed from the direction in which the axis of the accommodating portion extends. Curved at the first radius of curvature so as to project toward the axis of, and curved at the first portion extending along the bottom wall so as to cross the bottom wall and at the second radius of curvature smaller than the first radius of curvature. A second portion extending along the outer peripheral wall, an arcuate third portion connected to the first end of the first portion and the first end of the second portion in the circumferential direction of the accommodating portion, and the above. Provided is a cooker having an arcuate fourth portion connected to a second end of the first portion and a second end of the second portion in the circumferential direction of the accommodating portion.

この調理器では、第１部分が鍋の底面部を局部的に加熱し、第２部分が鍋の側面部を局部的に加熱し、第３部分と第４部分が鍋の底面部から側面部にかけて局部的に加熱する。第１部分の第１曲率半径は第２部分の第２曲率半径よりも大きいため、鍋の底面部の加熱領域を広く確保できる。よって、加熱調理において重要な鍋の底面部側の加熱性を向上できる。 In this cooker, the first part heats the bottom of the pot locally, the second part heats the side of the pot locally, and the third and fourth parts from the bottom to the side of the pot. Heat locally. Since the first radius of curvature of the first portion is larger than the second radius of curvature of the second portion, a wide heating region on the bottom surface of the pan can be secured. Therefore, it is possible to improve the heatability of the bottom surface of the pot, which is important in cooking.

第１部分から第４部分は円弧状であり、コイルには直線部分が無い。コイルを製造する際、コイルに直線部分が存在する場合、直線部分では張力が過少になる一方、直線部分の両端では張力が過多になる。しかし、この態様では直線部分が無いため、定められた部位に所定の張力を加えて素線又はリッツ線を巻回できる。よって、定められた形状のコイルを確実に製造できるとともに、コイルの生産性を向上できる。 The first to fourth parts are arcuate, and the coil has no straight part. When manufacturing a coil, if the coil has a straight portion, the tension is low at the straight portion, while the tension is high at both ends of the straight portion. However, since there is no straight portion in this embodiment, a predetermined tension can be applied to a predetermined portion to wind the strand wire or the litz wire. Therefore, a coil having a predetermined shape can be reliably manufactured, and the productivity of the coil can be improved.

前記第２曲率半径に対する前記第１曲率半径の割合は、１００％以上１６０％以下である。この態様によれば、第１部分による鍋の底面部の加熱領域を効果的に確保できる。 The ratio of the first radius of curvature to the second radius of curvature is 100% or more and 160% or less. According to this aspect, the heating region of the bottom surface of the pot by the first portion can be effectively secured.

前記収容部の軸線が延びる方向において、前記第３部分の内周部の厚み及び前記第４部分の内周部の厚みはそれぞれ、前記第３部分の外周部の厚み及び前記第４部分の外周部の厚みよりも厚い。具体的には、前記第３部分の厚み及び前記第４部分の厚みはそれぞれ、前記内周部から前記外周部に向けて次第に薄くなっている。この態様によれば、鍋の底面部側では、単位面積当たりの素線数が側面部側の単位面積当たりの素線数よりも多くなるため、加熱量を確保できる。また、鍋の側面部側では、単位面積当たりの素線数は少なくなるが、コイルを配置可能な範囲を拡張できるため、加熱領域を確保できる。しかも、鍋の側面部側では、素線数の減少によってコイルの柔軟性が向上するため、底壁から外周壁までの外面形状に対するフィット性を向上できる。 In the direction in which the axis of the accommodating portion extends, the thickness of the inner peripheral portion of the third portion and the thickness of the inner peripheral portion of the fourth portion are the thickness of the outer peripheral portion of the third portion and the outer circumference of the fourth portion, respectively. Thicker than the thickness of the part. Specifically, the thickness of the third portion and the thickness of the fourth portion are gradually reduced from the inner peripheral portion to the outer peripheral portion, respectively. According to this aspect, on the bottom surface side of the pan, the number of strands per unit area is larger than the number of strands per unit area on the side surface side, so that the amount of heating can be secured. Further, on the side surface side of the pan, the number of strands per unit area is small, but the range in which the coil can be arranged can be expanded, so that a heating region can be secured. Moreover, on the side surface side of the pan, the flexibility of the coil is improved by reducing the number of wires, so that the fit to the outer surface shape from the bottom wall to the outer peripheral wall can be improved.

前記コイルを２個のみ備える。また、前記外周壁を貫通して前記鍋の温度を検出するセンサを備え、前記収容部の軸線が延びる方向から前記収容部を見て、前記２個のコイルは、前記底壁の中央及び前記センサを通る基準線に対して対称に配置されている。この態様によれば、２個のコイルによって鍋の底面部側を偏り無く加熱できる。また、１個のセンサによって２個のコイルによる鍋の加熱温度を偏りなく検出できる。 Only two of the coils are provided. Further, a sensor for detecting the temperature of the pot through the outer peripheral wall is provided, and the accommodating portion is viewed from the direction in which the axis of the accommodating portion extends, and the two coils are located at the center of the bottom wall and said. It is arranged symmetrically with respect to the reference line passing through the sensor. According to this aspect, the bottom surface side of the pan can be heated evenly by the two coils. In addition, the heating temperature of the pot by the two coils can be detected evenly by one sensor.

前記センサに最も近接した前記第３部分又は前記第４部分と前記センサとの間の隙間は、２０ｍｍ以下である。前述のように、第３部分及び第４部分の外周部の厚みを内周部の厚みよりも薄くすることで、側面部での加熱領域を拡張してセンサに近づけることができる。そして、第３部分又は第４部分とセンサの配置をこの態様のように構成すれば、コイルによって加熱した鍋の温度をセンサによって検出する際の応答性を向上できる。 The gap between the sensor and the third or fourth portion closest to the sensor is 20 mm or less. As described above, by making the thickness of the outer peripheral portion of the third portion and the fourth portion thinner than the thickness of the inner peripheral portion, the heating region on the side surface portion can be expanded and brought closer to the sensor. Then, if the arrangement of the third part or the fourth part and the sensor is configured as in this embodiment, the responsiveness when the temperature of the pot heated by the coil is detected by the sensor can be improved.

前記収容部の軸線が延びる方向における前記第１部分の厚み及び前記第２部分の厚みはそれぞれ、内周部から外周部にかけて一様であり、前記第１部分を構成する素線の密度は、前記第２部分を構成する素線の密度よりも高い。この態様によれば、鍋の底面部における単位面積当たりの加熱量を確保できるとともに、鍋の側面部にける加熱領域を確保できる。 The thickness of the first portion and the thickness of the second portion in the direction in which the axis of the accommodating portion extends are uniform from the inner peripheral portion to the outer peripheral portion, respectively, and the density of the strands constituting the first portion is It is higher than the density of the strands constituting the second part. According to this aspect, the heating amount per unit area on the bottom surface of the pan can be secured, and the heating region on the side surface of the pan can be secured.

本発明の調理器では、第１部分の第１曲率半径が第２部分の第２曲率半径よりも大きいため、複数のコイルによる鍋の底面部側の加熱性を向上できる。また、コイルには直線部分が無いため、コイルの生産性を向上できる。 In the cooker of the present invention, since the first radius of curvature of the first portion is larger than the second radius of curvature of the second portion, it is possible to improve the heatability of the bottom surface side of the pan by the plurality of coils. Further, since the coil does not have a straight portion, the productivity of the coil can be improved.

本発明の実施形態に係る調理器の断面図。Sectional drawing of the cooker which concerns on embodiment of this invention. 保護枠とコイルの分解斜視図。An exploded perspective view of the protective frame and coil. 保護枠とコイルの底面図。Bottom view of the protective frame and coil. １個のコイルの底面図。Bottom view of one coil. 図４のＶ−Ｖ線断面図。FIG. 4 is a sectional view taken along line VV of FIG. 図４のＶＩ−ＶＩ線端面図。VI-VI line end view of FIG. 図５の一部拡大図。A partially enlarged view of FIG. 図５の図７とは異なる部分の一部拡大図。A partially enlarged view of a portion different from FIG. 7 of FIG. 図６の拡大図。Enlarged view of FIG. コイルの第１部分の曲率を変えた場合の比較例を示す底面図。The bottom view which shows the comparative example when the curvature of the 1st part of a coil is changed.

以下、本発明の実施の形態を図面に従って説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

図１は、本発明の実施形態に係る調理器の一例である炊飯器１０を示す。この炊飯器１０は、炊飯鍋（鍋）１５が配置された炊飯器本体２０と、炊飯器本体２０に開閉可能に取り付けられた蓋体３５とを備え、炊飯器本体２０に複数（本実施形態では２個）のコイル２５Ａ，２５Ｂを配置したマルチコイル型である。本実施形態では、コイル２５Ａ，２５Ｂの形状を最適化することで、炊飯鍋１５の加熱性を向上する。 FIG. 1 shows a rice cooker 10 which is an example of a cooker according to an embodiment of the present invention. The rice cooker 10 includes a rice cooker main body 20 in which a rice cooker (pot) 15 is arranged, and a lid 35 attached to the rice cooker main body 20 so as to be openable and closable, and a plurality of rice cooker main bodies 20 (the present embodiment). This is a multi-coil type with two coils 25A and 25B arranged. In the present embodiment, the heatability of the rice cooking pot 15 is improved by optimizing the shapes of the coils 25A and 25B.

（炊飯器の概要）
図１に示すように、炊飯鍋１５は、磁性材料からなり、プレス加工又は鋳造によって形成した一体構造である。炊飯鍋１５は有底筒状であり、円板状の底面部１６と、底面部１６の外周から立ち上がった側面部１７とを備える。側面部１７は、底面部１６の中心を通る軸線を有する筒状である。 (Overview of rice cooker)
As shown in FIG. 1, the rice cooker 15 is made of a magnetic material and has an integral structure formed by press working or casting. The rice cooking pot 15 has a bottomed tubular shape, and includes a disk-shaped bottom surface portion 16 and a side surface portion 17 rising from the outer periphery of the bottom surface portion 16. The side surface portion 17 has a tubular shape having an axis passing through the center of the bottom surface portion 16.

炊飯器本体２０は、外装体２１内に炊飯鍋１５を着脱可能に収容する有底筒状の収容部２２を備える。収容部２２の内面側に炊飯鍋１５を収容することで、保護枠２４（収容部２２）の軸線Ａと炊飯鍋１５の軸線とが一致する。収容部２２は、外装体２１の上面に形成された開口の下部に設けられている。収容部２２は、側面部１７の上部と間隔をあけて位置する内胴２３と、底面部１６及び側面部１７の下部と間隔をあけて位置する保護枠２４とを備える。内胴２３は、金属製で、直径が一様な円筒状である。保護枠２４は、樹脂（非導電性材料）製で、内胴２３の下端に配置された受皿状である。 The rice cooker main body 20 includes a bottomed tubular accommodating portion 22 for detachably accommodating the rice cooker 15 inside the exterior body 21. By accommodating the rice cooking pot 15 on the inner surface side of the accommodating portion 22, the axis A of the protective frame 24 (accommodating portion 22) and the axis of the rice cooking pot 15 coincide with each other. The accommodating portion 22 is provided below the opening formed on the upper surface of the exterior body 21. The accommodating portion 22 includes an inner body 23 located at a distance from the upper portion of the side surface portion 17, and a protective frame 24 located at a distance from the lower surface portion 16 and the lower portion of the side surface portion 17. The inner body 23 is made of metal and has a cylindrical shape having a uniform diameter. The protective frame 24 is made of resin (non-conductive material) and has a saucer shape arranged at the lower end of the inner body 23.

図２及び図３を参照すると、保護枠２４の外面側には、保護枠２４の軸線Ａを中心として周方向に並べて２個のコイル２５Ａ，２５Ｂが配置されている。図１を参照すると、コイル２５Ａ，２５Ｂの外側にはそれぞれ、フェライトコア３０を保持するホルダ３１が配置されており、このホルダ３１と保護枠２４の間にコイル２５Ａ，２５Ｂが保持（固定）されている。コイル２５Ａ，２５Ｂは、高周波電流が通電されることで渦電流を発生させ、炊飯鍋１５を誘導加熱する。 Referring to FIGS. 2 and 3, two coils 25A and 25B are arranged on the outer surface side of the protective frame 24 so as to be arranged in the circumferential direction with the axis A of the protective frame 24 as the center. Referring to FIG. 1, holders 31 for holding the ferrite core 30 are arranged outside the coils 25A and 25B, respectively, and the coils 25A and 25B are held (fixed) between the holder 31 and the protective frame 24. ing. The coils 25A and 25B generate an eddy current when a high-frequency current is applied to induce and heat the rice cooker 15.

図１に示すように、蓋体３５は、図１において右側に位置する炊飯器本体２０の背部のヒンジ接続部３６に回転可能に取り付けられている。蓋体３５は、炊飯鍋１５を臨む内面側（図１において下側）に放熱板３７を備える。放熱板３７の下側には、炊飯鍋１５の上端開口を閉塞する内蓋３８が設けられている。蓋体３５に対して内蓋３８は、着脱可能な構成としてもよいし、取り外しが不可能な構成としてもよい。放熱板３７の上面には、放熱板３７を介して内蓋３８を加熱し、内蓋３８に付着した露を蒸発させる蓋ヒータ３９が配設されている。 As shown in FIG. 1, the lid 35 is rotatably attached to the hinge connecting portion 36 on the back of the rice cooker main body 20 located on the right side in FIG. The lid 35 is provided with a heat radiating plate 37 on the inner surface side (lower side in FIG. 1) facing the rice cooking pot 15. An inner lid 38 that closes the upper end opening of the rice cooking pot 15 is provided on the lower side of the heat radiating plate 37. The inner lid 38 may be detachable with respect to the lid 35, or may be non-removable. A lid heater 39 is provided on the upper surface of the heat radiating plate 37 to heat the inner lid 38 via the heat radiating plate 37 and evaporate the dew adhering to the inner lid 38.

引き続いて図１を参照すると、炊飯器１０には、炊飯鍋１５内の温度を検出する検出部として、２個のセンサ４１，４２が配置されている。第１のセンサ４１は炊飯器本体２０内に配置され、第２のセンサ４２は蓋体３５内に配置されている。センサ（サイドセンサ）４１は、保護枠２４を貫通して炊飯鍋１５の外面に接触するように配置され、炊飯鍋１５を介して内部の水を含む飯米温度又は米飯温度を検出する。センサ４２は、放熱板３７に接触するように配置され、放熱板３７を介して炊飯鍋１５内（放熱板３７と内蓋３８の間の空間）の温度を検出する。 Subsequently, referring to FIG. 1, two sensors 41 and 42 are arranged in the rice cooker 10 as a detection unit for detecting the temperature in the rice cooker 15. The first sensor 41 is arranged in the rice cooker main body 20, and the second sensor 42 is arranged in the lid 35. The sensor (side sensor) 41 is arranged so as to penetrate the protective frame 24 and come into contact with the outer surface of the rice cooking pot 15, and detects the cooked rice temperature or the cooked rice temperature containing water inside through the rice cooking pot 15. The sensor 42 is arranged so as to come into contact with the heat radiating plate 37, and detects the temperature inside the rice cooking pot 15 (the space between the heat radiating plate 37 and the inner lid 38) via the heat radiating plate 37.

炊飯器１０には、制御部（図示せず）を備える制御基板４４が配置されている。本実施形態の制御基板４４は、ホルダ４５を介して炊飯器本体２０の正面側に配置されているが、炊飯器本体２０の背面側に配置されてもよいし、蓋体３５内に配置されてもよい。制御部は、単一又は複数のマイクロコンピュータ、及びその他の電子デバイスにより構成されている。制御部は、センサ４１，４２の検出温度に基づいてコイル２５Ａ，２５Ｂ及び蓋ヒータ３９を制御し、予熱工程、中ぱっぱ（昇温）工程、沸騰維持工程、及びむらし工程を含む炊飯処理を実行する。 A control board 44 including a control unit (not shown) is arranged on the rice cooker 10. The control board 44 of the present embodiment is arranged on the front side of the rice cooker main body 20 via the holder 45, but may be arranged on the back side of the rice cooker main body 20 or is arranged in the lid 35. You may. The control unit is composed of a single microcomputer or a plurality of microcomputers, and other electronic devices. The control unit controls the coils 25A and 25B and the lid heater 39 based on the detected temperatures of the sensors 41 and 42, and performs a rice cooking process including a preheating step, a middle papa (heating) step, a boiling maintenance step, and an unevenness step. Execute.

炊飯処理の実行時、制御部は、２個のコイル２５Ａ，２５Ｂのうち、一方が通電されて他方の通電が遮断されるように、通電状態を交互に切り換える。つまり、コイル２５Ａを電気的に接続してコイル２５Ｂを遮断した第１通電状態と、コイル２５Ｂを電気的に接続してコイル２５Ａを遮断した第２通電状態とを、交互に繰り返す。これらの切換周期は、工程毎に異なっていてもよいし、全ての工程で同じであってもよい。但し、炊飯鍋１５内を急速に昇温させる中ぱっぱ工程では、炊飯鍋１５内を定められた温度に維持（温調）する中ぱっぱ工程以外よりも、切換周期を長くすることが好ましい。 When the rice cooking process is executed, the control unit alternately switches the energized state so that one of the two coils 25A and 25B is energized and the other is de-energized. That is, the first energized state in which the coil 25A is electrically connected and the coil 25B is cut off and the second energized state in which the coil 25B is electrically connected and the coil 25A is cut off are alternately repeated. These switching cycles may be different for each step, or may be the same for all steps. However, in the middle-papping step of rapidly raising the temperature inside the rice-cooking pot 15, it is preferable to lengthen the switching cycle as compared with the middle-papping step of maintaining (temperature adjusting) the inside of the rice-cooking pot 15 at a predetermined temperature.

一般的に、日本の家庭に設けられた配電盤は２０アンペアでコンセントが１５アンペアのものが多いため、この種の炊飯器１０を含む電気機器において、単位時間当たりに投入可能な定格電力は最大で１５００Ｗである。底面部１６全体を覆う１個のコイルを用いた炊飯器の場合、定格電力に応じた加熱量で炊飯鍋１５全体が誘導加熱される。これに対して本実施形態の炊飯器１０では、２個のコイル２５Ａ，２５Ｂのうちの一方に定格電力が最大で投入されるため、対応する炊飯鍋１５の１／２の加熱領域が、定格電力に応じた加熱量が最大で集中して誘導加熱される。よって、１個のコイルを用いた炊飯器と比較して、本実施形態の炊飯器１０では炊飯鍋１５の単位面積当たりの最大加熱量を大きくできる。その結果、本実施形態では、炊飯鍋１５の局部を大きな熱量で集中して加熱できる。 In general, most switchboards installed in Japanese homes have 20 amperes and outlets of 15 amperes, so the maximum rated power that can be input per unit time in electrical equipment including this type of rice cooker 10. It is 1500W. In the case of a rice cooker using one coil that covers the entire bottom surface 16, the entire rice cooker 15 is induced and heated by a heating amount corresponding to the rated power. On the other hand, in the rice cooker 10 of the present embodiment, since the rated power is input to one of the two coils 25A and 25B at the maximum, the heating region of 1/2 of the corresponding rice cooker 15 is rated. The amount of heating according to the electric power is concentrated at the maximum and induction heating is performed. Therefore, as compared with the rice cooker using one coil, the rice cooker 10 of the present embodiment can increase the maximum heating amount per unit area of the rice cooker 15. As a result, in the present embodiment, the local portion of the rice cooking pot 15 can be concentrated and heated with a large amount of heat.

炊飯鍋１５の加熱領域は、コイル２５Ａ，２５Ｂへの通電によって発生した磁界中に位置する部分であり、その形状はコイル２５Ａ，２５Ｂの形状に対応する。また、炊飯鍋１５の加熱量はコイル２５Ａ，２５Ｂによる磁束の量に対応し、その磁束量はコイル２５Ａ，２５Ｂを構成する素線２５ａ（図７から図９参照）の数に対応する。炊飯鍋１５において加熱領域以外の非加熱領域は、加熱領域の熱が伝わることで昇温する。この非加熱領域が多くなるに従って、コイル２５Ａ，２５Ｂによる炊飯鍋１５の加熱効率は低下する。つまり、炊飯鍋１５の加熱効率を向上するには、投入電力の他に、炊飯鍋１５の底面部１６側の加熱性の向上が重要である。そこで、本実施形態では、保護枠２４に配置するコイル２５Ａ，２５Ｂを以下のように構成している。 The heating region of the rice cooking pot 15 is a portion located in the magnetic field generated by energizing the coils 25A and 25B, and the shape corresponds to the shape of the coils 25A and 25B. The heating amount of the rice cooker 15 corresponds to the amount of magnetic flux generated by the coils 25A and 25B, and the amount of magnetic flux corresponds to the number of strands 25a (see FIGS. 7 to 9) constituting the coils 25A and 25B. In the rice cooking pot 15, the temperature of the non-heated region other than the heated region is raised by transferring the heat of the heated region. As the non-heated region increases, the heating efficiency of the rice cooking pot 15 by the coils 25A and 25B decreases. That is, in order to improve the heating efficiency of the rice cooking pot 15, it is important to improve the heating performance on the bottom surface 16 side of the rice cooking pot 15 in addition to the input power. Therefore, in the present embodiment, the coils 25A and 25B arranged in the protective frame 24 are configured as follows.

（保護枠とコイルの概要）
図１を参照すると、図２及び図３に示すように、複数のコイル２５Ａ，２５Ｂは同一構成であり、保護枠２４の定められた位置に配置されている。本実施形態のコイル２５Ａ，２５Ｂは２個であるため、保護枠２４の径方向に延びる基準線Ｌに対して対称に配置されている。保護枠２４は、炊飯鍋１５の下部の外面形状に対応する形状を有する。 (Outline of protective frame and coil)
Referring to FIG. 1, as shown in FIGS. 2 and 3, the plurality of coils 25A and 25B have the same configuration and are arranged at a predetermined position of the protective frame 24. Since there are two coils 25A and 25B in this embodiment, they are arranged symmetrically with respect to the reference line L extending in the radial direction of the protective frame 24. The protective frame 24 has a shape corresponding to the outer surface shape of the lower part of the rice cooking pot 15.

具体的には、図１に示すように、炊飯鍋１５は、前述のように底面部１６と側面部１７とを備える。そのうち、側面部１７は、大略、第１部分１７ａ、第２部分１７ｂ、及び第３部分１７ｃを備える。第１部分１７ａは、底面部１６の外周に連なり、下側から上側に向けて直径を次第に大きくした曲面状である。第２部分１７ｂは、第１部分１７ａの上端に連なり、下側から上側に向けて直径を次第に大きくした円錐筒状である。第３部分１７ｃは、第２部分１７ｂの上端に連なり、下側から上側に向けて直径を一様とした円筒状である。 Specifically, as shown in FIG. 1, the rice cooking pot 15 includes a bottom surface portion 16 and a side surface portion 17 as described above. Among them, the side surface portion 17 roughly includes a first portion 17a, a second portion 17b, and a third portion 17c. The first portion 17a has a curved surface shape that is continuous with the outer periphery of the bottom surface portion 16 and whose diameter is gradually increased from the lower side to the upper side. The second portion 17b has a conical cylinder shape that is continuous with the upper end of the first portion 17a and whose diameter is gradually increased from the lower side to the upper side. The third portion 17c has a cylindrical shape that is continuous with the upper end of the second portion 17b and has a uniform diameter from the lower side to the upper side.

図１から図３を参照すると、保護枠２４は、底面部１６と間隔をあけて位置する円形状の底壁２４ａと、側面部１７と間隔をあけて位置する外周壁２４ｂとを備える。そのうち、外周壁２４ｂは、底壁２４ａの外周から立ち上がる筒状であり、第１部分１７ａに対応する第１部分２４ｃと、第２部分１７ｂに対応する第２部分２４ｄとを備える。第１部分２４ｃは、底壁２４ａの外周に連なり、下側から上側に向けて直径を次第に大きくした曲面状である。第２部分２４ｄは、第１部分２４ｃの上端に連なり、下側から上側に向けて直径を次第に大きくした円錐筒状である。 Referring to FIGS. 1 to 3, the protective frame 24 includes a circular bottom wall 24a located at a distance from the bottom surface portion 16 and an outer peripheral wall 24b located at a distance from the side surface portion 17. Among them, the outer peripheral wall 24b has a tubular shape rising from the outer periphery of the bottom wall 24a, and includes a first portion 24c corresponding to the first portion 17a and a second portion 24d corresponding to the second portion 17b. The first portion 24c has a curved surface shape that is continuous with the outer periphery of the bottom wall 24a and whose diameter is gradually increased from the lower side to the upper side. The second portion 24d has a conical cylinder shape that is continuous with the upper end of the first portion 24c and gradually increases in diameter from the lower side to the upper side.

保護枠２４は、センサ４１を取り付ける取付部２４ｅを備える。取付部２４ｅは、外周壁２４ｂにおける第２部分２４ｄに設けられおり、円形状の貫通孔２４ｆと、貫通孔２４ｆの周囲から外向きに突出する筒状の突出部２４ｇとを備える。図３に最も明瞭に示すように、取付部２４ｅは、保護枠２４の軸線Ａが延びる方向から見て概ね平面視長方形状に形成された外装体２１において、４つの隅部のうちの１つに向けて突出している。この取付部２４ｅにセンサ４１を取り付けることで、保護枠２４を貫通した検出部が側面部１７の第２部分１７ｂに当接する。なお、センサ４１は、本実施形態では外装体２１の後側に配置されているが、外装体２１の前側に配置されてもよい。 The protective frame 24 includes a mounting portion 24e for mounting the sensor 41. The mounting portion 24e is provided in the second portion 24d of the outer peripheral wall 24b, and includes a circular through hole 24f and a tubular protruding portion 24g that projects outward from the periphery of the through hole 24f. As most clearly shown in FIG. 3, the mounting portion 24e is one of four corners of the exterior body 21 formed in a substantially rectangular shape in a plan view when viewed from the direction in which the axis A of the protective frame 24 extends. It protrudes toward. By attaching the sensor 41 to the attachment portion 24e, the detection portion penetrating the protective frame 24 comes into contact with the second portion 17b of the side surface portion 17. Although the sensor 41 is arranged on the rear side of the exterior body 21 in this embodiment, it may be arranged on the front side of the exterior body 21.

図２に最も明瞭に示すように、保護枠２４は、コイル２５Ａ，２５Ｂをそれぞれ位置決めするためのリブ２４ｈと、ホルダ３１を固定するためのボス２４ｉとを備える。コイル２５Ａ用のリブ２４ｈ及びボス２４ｉと、コイル２５Ｂ用のリブ２４ｈ及びボス２４ｉとは、底壁２４ａの中央（保護枠２４の軸線Ａ）及び取付部２４ｅ（センサ４１）を通る基準線Ｌに対して対称に設けられている。リブ２４ｈは、概ね楕円形状をなすコイル２５Ａ，２５Ｂの内周部２５ｂにおいて、短軸方向の両端のうちの一方（内側）に１個設けられて他方（外側）に２個設けられ、長軸方向の両端に１個ずつ設けられている。また、リブ２４ｈは、一対のコイル２５Ａ，２５Ｂの間にも２個設けられている。ボス２４ｉは、コイル２５Ａ，２５Ｂの内周部２５ｂにおいて、短軸方向の外側に２個設けられ、長軸方向の両端に１個ずつ設けられている。 As most clearly shown in FIG. 2, the protective frame 24 includes ribs 24h for positioning the coils 25A and 25B, respectively, and a boss 24i for fixing the holder 31. The ribs 24h and boss 24i for the coil 25A and the ribs 24h and boss 24i for the coil 25B are on the reference line L passing through the center of the bottom wall 24a (axis A of the protective frame 24) and the mounting portion 24e (sensor 41). On the other hand, it is provided symmetrically. One rib 24h is provided on one (inside) and two on the other (outside) of both ends in the minor axis direction in the inner peripheral portion 25b of the coils 25A and 25B having a substantially elliptical shape, and the major axis is provided. One is provided at each end of the direction. Further, two ribs 24h are also provided between the pair of coils 25A and 25B. Two bosses 24i are provided on the inner peripheral portions 25b of the coils 25A and 25B on the outer side in the minor axis direction, and one boss 24i is provided on both ends in the major axis direction.

図２から図４に示すように、個々のコイル２５Ａ，２５Ｂは、複数の素線２５ａ（図７から図９参照）を非対称な楕円環形状に巻回することで形成されている。コイル２５Ａ，２５Ｂは、概ね楕円形状の内周部２５ｂと、概ね半円形状の外周部２５ｃとを備える。内周部２５ｂには第１の接続線２５ｄが延設され、外周部２５ｃには第２の接続線２５ｅが延設されている。接続線２５ｄ，２５ｅは、絶縁性を有するチューブによってそれぞれ覆われ、隣接したコイル２５Ａ，２５Ｂ間を通して制御基板４４に電気的に接続される。 As shown in FIGS. 2 to 4, the individual coils 25A and 25B are formed by winding a plurality of strands 25a (see FIGS. 7 to 9) into an asymmetric elliptical ring shape. The coils 25A and 25B include an inner peripheral portion 25b having a substantially elliptical shape and an outer peripheral portion 25c having a substantially semicircular shape. A first connecting line 25d is extended to the inner peripheral portion 25b, and a second connecting line 25e is extended to the outer peripheral portion 25c. The connecting lines 25d and 25e are covered with insulating tubes, respectively, and are electrically connected to the control board 44 through the adjacent coils 25A and 25B.

コイル２５Ａ，２５Ｂはそれぞれ、炊飯鍋１５の底面部１６から側面部１７の第１部分１７ａにかけた領域を加熱するように、保護枠２４の底壁２４ａから外周壁２４ｂの第１部分２４ｃにかけた領域に配置されている。図３に最も明瞭に示すように、収容部２２の軸線Ａが延びる方向から収容部２２を見ると、２個のコイル２５Ａ，２５Ｂは、保護枠２４の軸線Ａを中心として周方向に並べて配置され、基準線Ｌに対して対称に配置されている。 The coils 25A and 25B were respectively applied from the bottom wall 24a of the protective frame 24 to the first portion 24c of the outer peripheral wall 24b so as to heat the region from the bottom surface 16 of the rice cooking pot 15 to the first portion 17a of the side surface 17. It is located in the area. As shown most clearly in FIG. 3, when the accommodating portion 22 is viewed from the direction in which the axis A of the accommodating portion 22 extends, the two coils 25A and 25B are arranged side by side in the circumferential direction with the axis A of the protective frame 24 as the center. And are arranged symmetrically with respect to the reference line L.

より具体的には、図３及び図４に示すように、個々のコイル２５Ａ，２５Ｂは、底壁２４ａに沿って延びる第１部分２６と、外周壁２４ｂに沿って延びる第２部分２７と、これらに連なる第３部分２８及び第４部分２９とを備える。図３及び図４には、これらの境界部分を一点鎖線（仮想線）で示している。これらはいずれも、所定曲率の円弧形状に形成されているが、厳密な円弧形状に限られず、一端から他端までが実質的に円弧状であればよい。 More specifically, as shown in FIGS. 3 and 4, the individual coils 25A and 25B have a first portion 26 extending along the bottom wall 24a and a second portion 27 extending along the outer peripheral wall 24b. A third portion 28 and a fourth portion 29 connected thereto are provided. In FIGS. 3 and 4, these boundary portions are shown by alternate long and short dash lines (virtual lines). All of these are formed in an arc shape having a predetermined curvature, but the shape is not limited to a strict arc shape, and it is sufficient that one end to the other end is substantially an arc shape.

第１部分２６は、収容部２２の軸線Ａが延びる方向から収容部２２を見て、収容部２２の軸線Ａに向けて内向き突出し、定められた曲率半径（第１曲率半径）ｒ１で湾曲している。第１部分２６は、底壁２４ａを横切るように基準線Ｌに沿って延びている。コイル２５Ａにおける第１部分２６の外周部２５ｃとコイル２５Ｂにおける第１部分２６の外周部２５ｃとは、定められた間隔（例えば１０ｍｍ）をあけて位置する。 The first portion 26 looks at the accommodating portion 22 from the direction in which the axis A of the accommodating portion 22 extends, projects inward toward the axis A of the accommodating portion 22, and curves at a predetermined radius of curvature (first radius of curvature) r1. doing. The first portion 26 extends along the reference line L so as to cross the bottom wall 24a. The outer peripheral portion 25c of the first portion 26 of the coil 25A and the outer peripheral portion 25c of the first portion 26 of the coil 25B are located at a predetermined interval (for example, 10 mm).

第２部分２７は、内周部２５ｂの短軸方向において第１部分２６の逆側に位置し、第１部分２６とは逆向き（外向き）に突出するように、曲率半径ｒ１よりも小さい曲率半径（第２曲率半径）ｒ２で湾曲している。第２部分２７は、保護枠２４の軸線Ａを中心として、外周壁２４ｂの第１部分２４ｃに沿って延びている。 The second portion 27 is located on the opposite side of the first portion 26 in the minor axis direction of the inner peripheral portion 25b, and is smaller than the radius of curvature r1 so as to project in the opposite direction (outward direction) to the first portion 26. It is curved with a radius of curvature (second radius of curvature) r2. The second portion 27 extends along the first portion 24c of the outer peripheral wall 24b with the axis A of the protective frame 24 as the center.

第３部分２８は、収容部２２の周方向における第１部分２６の第１端２６ａ及び第２部分２７の第１端２７ａに連なり、保護枠２４の径方向外向きに突出するように、曲率半径ｒ２よりも小さい曲率半径（第３曲率半径）ｒ３で湾曲している。第１部分２６の第１端２６ａ及び第２部分２７の第１端２７ａは、外装体２１の前後方向の同じ側に位置する部分である。 The third portion 28 is connected to the first end 26a of the first portion 26 and the first end 27a of the second portion 27 in the circumferential direction of the accommodating portion 22, and is curved so as to project outward in the radial direction of the protective frame 24. It is curved with a radius of curvature (third radius of curvature) r3 smaller than the radius r2. The first end 26a of the first portion 26 and the first end 27a of the second portion 27 are portions of the exterior body 21 located on the same side in the front-rear direction.

第４部分２９は、収容部２２の周方向における第１部分２６の第２端２６ｂと第２部分２７の第２端２７ｂとに連なり、保護枠２４の径方向外向きに突出するように、曲率半径ｒ２よりも小さい曲率半径（第４曲率半径）ｒ４で湾曲している。第１部分２６の第２端２６ｂ及び第２部分２７の第２端２７ｂは、外装体２１の前後方向において第１端２６ａ，２７ａとは逆側に位置する部分である。 The fourth portion 29 is connected to the second end 26b of the first portion 26 and the second end 27b of the second portion 27 in the circumferential direction of the accommodating portion 22, and projects outward in the radial direction of the protective frame 24. It is curved with a radius of curvature (fourth radius of curvature) r4 smaller than the radius of curvature r2. The second end 26b of the first portion 26 and the second end 27b of the second portion 27 are portions located on the opposite sides of the first ends 26a and 27a in the front-rear direction of the exterior body 21.

第２部分２７の曲率半径ｒ２に対する第１部分２６の曲率半径ｒ１の割合は、１００％以上１６０％以下に設定され、より好ましくは１４０％以上１５０％以下に設定されている。図１０に破線で示すように、曲率半径の割合を過度に小さくすると、第３部分２８及び第４部分２９が基準線Ｌから離れるため、コイル２５Ａ，２５Ｂによる加熱領域を確保できず、隣接したコイル２５Ａ，２５Ｂ間の非加熱領域が過度に広くなる。図１０に一点鎖線で示すように、曲率半径の割合を過度に大きくすると、第１部分２６が直線に近くなるため、後述するように、コイル２５Ａ，２５Ｂの製造時に定められた張力で素線２５ａを巻回できない。よって、第１部分２６による炊飯鍋１５の加熱領域を確保しつつ、コイル２５Ａ，２５Ｂの生産性を向上するために、曲率半径ｒ２に対する曲率半径ｒ１の割合は、上記範囲内に設定することが好ましい。 The ratio of the radius of curvature r1 of the first portion 26 to the radius of curvature r2 of the second portion 27 is set to 100% or more and 160% or less, and more preferably 140% or more and 150% or less. As shown by the broken line in FIG. 10, when the ratio of the radius of curvature is excessively small, the third portion 28 and the fourth portion 29 are separated from the reference line L, so that the heating region by the coils 25A and 25B cannot be secured and they are adjacent to each other. The unheated region between the coils 25A and 25B becomes excessively wide. As shown by the alternate long and short dash line in FIG. 10, if the ratio of the radius of curvature is excessively increased, the first portion 26 becomes close to a straight line. Therefore, as will be described later, the wires are drawn with the tension determined at the time of manufacturing the coils 25A and 25B. 25a cannot be wound. Therefore, in order to improve the productivity of the coils 25A and 25B while securing the heating region of the rice cooking pot 15 by the first portion 26, the ratio of the radius of curvature r1 to the radius of curvature r2 may be set within the above range. preferable.

第３部分２８の曲率半径ｒ３と第４部分２９の曲率半径ｒ４とは、同一に設定されている。これにより、コイル２５Ａ，２５Ｂはそれぞれ、内周部２５ｂの短軸方向に延びる中心線Ｃに対して線対称な形状を有する。よって、基準線Ｌに沿った方向における一端側と他端側とで、加熱領域が異なることを防止できるため、炊飯鍋１５を均等に加熱できる。 The radius of curvature r3 of the third portion 28 and the radius of curvature r4 of the fourth portion 29 are set to be the same. As a result, the coils 25A and 25B each have a shape that is line-symmetric with respect to the center line C extending in the minor axis direction of the inner peripheral portion 25b. Therefore, it is possible to prevent the heating region from being different between the one end side and the other end side in the direction along the reference line L, so that the rice cooking pot 15 can be heated evenly.

図３及び図５を参照すると、第１部分２６は、底壁２４ａに沿って延びる概ね平面状に形成されている。第２部分２７は、外周壁２４ｂの第１部分２４ｃに沿って保護枠２４の周方向に延びる曲面状に形成されている。保護枠２４の軸線Ａが延びる方向における第１部分２６の厚みＴａは、内周部２５ｂから外周部２５ｃにかけて一様である。保護枠２４の軸線Ａが延びる方向における第２部分２７の厚みＴｂも、内周部２５ｂから外周部２５ｃにかけて一様である。本実施形態の第１部分２６の厚みＴａと第２部分２７の厚みＴｂとは、同じである。 Referring to FIGS. 3 and 5, the first portion 26 is formed in a substantially flat shape extending along the bottom wall 24a. The second portion 27 is formed in a curved surface shape extending in the circumferential direction of the protective frame 24 along the first portion 24c of the outer peripheral wall 24b. The thickness Ta of the first portion 26 in the direction in which the axis A of the protective frame 24 extends is uniform from the inner peripheral portion 25b to the outer peripheral portion 25c. The thickness Tb of the second portion 27 in the direction in which the axis A of the protective frame 24 extends is also uniform from the inner peripheral portion 25b to the outer peripheral portion 25c. The thickness Ta of the first portion 26 and the thickness Tb of the second portion 27 of the present embodiment are the same.

内周部２５ｂから外周部２５ｃまでの第１部分２６の幅Ｗ１は、内周部２５ｂから外周部２５ｃまでの第２部分２７の幅（沿面距離）Ｗ２よりも小さい。図７を参照すると、第１部分２６を構成する多数の素線２５ａは、張力を加えることによって、密集して巻回されている。図８を参照すると、第２部分２７を構成する多数の素線２５ａは、第１部分２６の素線２５ａよりも弱い張力を加えることによって、第１部分２６よりも隙間を有するように巻回されている。つまり、第１部分２６を構成する素線２５ａの密度は、第２部分２７を構成する素線２５ａの密度よりも高い。これにより、同じ厚みＴａ，Ｔｂかつ同じ素線２５ａ数であっても、第１部分２６の幅Ｗ１と第２部分２７の幅Ｗ２とは異なっている。また、幅Ｗ１，Ｗ２の違いにより、単位面積当たりの第１部分２６の加熱量は、単位面積当たりの第２部分２７の加熱量よりも大きい。 The width W1 of the first portion 26 from the inner peripheral portion 25b to the outer peripheral portion 25c is smaller than the width (creeping distance) W2 of the second portion 27 from the inner peripheral portion 25b to the outer peripheral portion 25c. Referring to FIG. 7, a large number of strands 25a constituting the first portion 26 are densely wound by applying tension. Referring to FIG. 8, a large number of strands 25a constituting the second portion 27 are wound so as to have a gap more than that of the first portion 26 by applying a tension weaker than that of the strands 25a of the first portion 26. Has been done. That is, the density of the strands 25a constituting the first portion 26 is higher than the density of the strands 25a constituting the second portion 27. As a result, the width W1 of the first portion 26 and the width W2 of the second portion 27 are different even if the thicknesses Ta and Tb are the same and the number of strands is the same 25a. Further, due to the difference in widths W1 and W2, the heating amount of the first portion 26 per unit area is larger than the heating amount of the second portion 27 per unit area.

図４を参照すると、第３部分２８と第４部分２９とは、線対称な平面視形状に形成されている。図６を参照すると、これらは、外周壁２４ｂの第１部分２４ｃに沿って保護枠２４の径方向に延びる曲面状に形成されている。保護枠２４の軸線Ａが延びる方向において、第３部分２８の内周部２５ｂの厚みＴｃ１は、第３部分２８の外周部２５ｃの厚みＴｃ２よりも厚い。第３部分２８と同様に、第４部分２９の内周部２５ｂの厚みＴｃ１は、第４部分２９の外周部２５ｃの厚みＴｃ２よりも厚い。これらの厚みＴｃ１，Ｔｃ２はそれぞれ、内周部２５ｂから外周部２５ｃに向けて次第に薄くなっている。 Referring to FIG. 4, the third portion 28 and the fourth portion 29 are formed in a line-symmetrical plan view shape. Referring to FIG. 6, these are formed in a curved surface extending in the radial direction of the protective frame 24 along the first portion 24c of the outer peripheral wall 24b. In the direction in which the axis A of the protective frame 24 extends, the thickness Tc1 of the inner peripheral portion 25b of the third portion 28 is thicker than the thickness Tc2 of the outer peripheral portion 25c of the third portion 28. Similar to the third portion 28, the thickness Tc1 of the inner peripheral portion 25b of the fourth portion 29 is thicker than the thickness Tc2 of the outer peripheral portion 25c of the fourth portion 29. Each of these thicknesses Tc1 and Tc2 gradually becomes thinner from the inner peripheral portion 25b toward the outer peripheral portion 25c.

第３部分２８及び第４部分２９の内周部２５ｂの厚みＴｃ１は、第１部分２６の第１端２６ａと第２部分２７の第１端２７ａとの間の中央部分２８ａ，２９ａが最も薄い。つまり、第３部分２８及び第４部分２９の内周部２５ｂの厚みＴｃ１は、第１部分２６及び第２部分２７から離れるに従って次第に薄くなっている。第３部分２８及び第４部分２９の外周部２５ｃの厚みＴｃ２も同様に、第１部分２６及び第２部分２７から離れるに従って次第に薄くなっており、中央部分２８ａ，２９ａが最も薄い。図９を参照すると、第３部分２８及び第４部分２９を構成する多数の素線２５ａの密度は、第２部分２７を構成する素線２５ａの密度よりも高い。 The thickness Tc1 of the inner peripheral portion 25b of the third portion 28 and the fourth portion 29 is the thinnest in the central portions 28a and 29a between the first end 26a of the first portion 26 and the first end 27a of the second portion 27. .. That is, the thickness Tc1 of the inner peripheral portion 25b of the third portion 28 and the fourth portion 29 gradually becomes thinner as the distance from the first portion 26 and the second portion 27 increases. Similarly, the thickness Tc2 of the outer peripheral portion 25c of the third portion 28 and the fourth portion 29 gradually becomes thinner as the distance from the first portion 26 and the second portion 27 increases, and the central portions 28a and 29a are the thinnest. Referring to FIG. 9, the density of the large number of strands 25a constituting the third portion 28 and the fourth portion 29 is higher than the density of the strands 25a constituting the second portion 27.

このように、第３部分２８の厚み及び第４部分２９の厚みは、コイル２５Ａ，２５Ｂの周方向及び径方向の内側から外側に向かうに従って漸減されている。よって、素線２５ａの数が同じであっても、第１部分２６の表面積及び第２部分２７の表面積よりも、第３部分２８の表面積及び第４部分２９の表面積を拡張できる。その結果、第３部分２８の外周部２５ｃ及び第４部分２９の外周部２５ｃを、センサ４１に近づけることができる。言い換えれば、図３に示すように、第３部分２８の外周部２５ｃ及び第４部分２９の外周部２５ｃと取付部２４ｅ（センサ４１）との間の隙間Ｓを、センサ４１による検出応答性が良好な範囲に設定できる。 As described above, the thickness of the third portion 28 and the thickness of the fourth portion 29 are gradually reduced from the inside to the outside in the circumferential direction and the radial direction of the coils 25A and 25B. Therefore, even if the number of strands 25a is the same, the surface area of the third portion 28 and the surface area of the fourth portion 29 can be expanded more than the surface area of the first portion 26 and the surface area of the second portion 27. As a result, the outer peripheral portion 25c of the third portion 28 and the outer peripheral portion 25c of the fourth portion 29 can be brought closer to the sensor 41. In other words, as shown in FIG. 3, the detection responsiveness of the sensor 41 determines the gap S between the outer peripheral portion 25c of the third portion 28 and the outer peripheral portion 25c of the fourth portion 29 and the mounting portion 24e (sensor 41). Can be set in a good range.

具体的には、第３部分２８及び第４部分２９とセンサ４１との間の隙間Ｓは、２０ｍｍ以下で、可能な限り短い距離に設定することが好ましい。但し、保護枠２４に対するコイル２５Ａ，２５Ｂの組付性を考慮すると、８ｍｍ以上１７ｍｍ以下の範囲に設定することが好ましい。隙間Ｓを過度に小さくすると、コイル２５Ａ，２５Ｂの製造誤差によって、保護枠２４に対するコイル２５Ａ，２５Ｂの組立性が悪くなる虞がある。隙間Ｓを過度に大きくすると、センサ４１による検出応答性が悪くなる虞がある。これらの不都合を防止するために、隙間Ｓは、上記範囲内に設定することが好ましい。 Specifically, the gap S between the third portion 28 and the fourth portion 29 and the sensor 41 is preferably set to 20 mm or less and as short as possible. However, considering the assembling property of the coils 25A and 25B to the protective frame 24, it is preferable to set the coil in the range of 8 mm or more and 17 mm or less. If the gap S is made excessively small, the assembling property of the coils 25A and 25B with respect to the protective frame 24 may deteriorate due to a manufacturing error of the coils 25A and 25B. If the gap S is made excessively large, the detection responsiveness of the sensor 41 may deteriorate. In order to prevent these inconveniences, the gap S is preferably set within the above range.

次に、コイル２５Ａ，２５Ｂの製造方法の一例を説明する。但し、コイル２５Ａ，２５Ｂの製造方法はこれに限られない。 Next, an example of a method for manufacturing the coils 25A and 25B will be described. However, the manufacturing method of the coils 25A and 25B is not limited to this.

コイル２５Ａ，２５Ｂは、ボビンとフィーダとを備えるコイル製造機によって製造される。ボビンは、コイル２５Ａ，２５Ｂの内面形状に対応する形状の第１面を有する第１型と、コイル２５Ａ，２５Ｂの外面形状に対応する形状の第２面を有する第２型とを備える。フィーダは、複数本（例えば３２本）の素線２５ａ（図７から図９参照）を撚り合わせたリッツ線を送出する。 The coils 25A and 25B are manufactured by a coil making machine including a bobbin and a feeder. The bobbin includes a first type having a first surface having a shape corresponding to the inner surface shape of the coils 25A and 25B, and a second type having a second surface having a shape corresponding to the outer surface shape of the coils 25A and 25B. The feeder sends out a litz wire obtained by twisting a plurality of (for example, 32) strands 25a (see FIGS. 7 to 9).

上下方向に延びる回転軸を中心としてボビンを回転させ、フィーダによって所定の張力を加えながらリッツ線をボビンで巻き取る。これにより、第１型と第２型の間の空間に応じた厚み及び形状のコイル２５Ａ，２５Ｂが巻回される。ボビンから突出した巻き始めの部分が接続線２５ｄを構成し、ボビンから突出した巻き終わりの部分が接続線２５ｅを構成する。リッツ線を巻回し終わると、通電によって素線２５ａを昇温させる。これにより、素線２５ａの外周部分の融着層を融解し、隣接した素線２５ａ同士を融着する。その結果、ボビンの空間に応じた定められた形状のコイル２５Ａ，２５Ｂが形成される。 The bobbin is rotated around a rotation axis extending in the vertical direction, and the litz wire is wound by the bobbin while applying a predetermined tension by the feeder. As a result, the coils 25A and 25B having a thickness and shape corresponding to the space between the first mold and the second mold are wound. The winding start portion protruding from the bobbin constitutes the connecting wire 25d, and the winding end portion protruding from the bobbin constitutes the connecting wire 25e. When the litz wire has been wound, the wire 25a is heated by energization. As a result, the fusion layer on the outer peripheral portion of the strands 25a is melted, and the adjacent strands 25a are fused together. As a result, the coils 25A and 25B having a predetermined shape according to the bobbin space are formed.

ここで、保護枠２４の軸線Ａが延びる方向から見てコイルがＤ字形状の場合、つまり第１部分２６が直線状の場合、第１部分２６にリッツ線を巻き付ける際、第２部分２７に向けた張力をリッツ線に加えることができない。しかも、第１部分２６のリッツ線の巻回時、先に巻き付けた第３部分２８又は第４部分２９に過度の張力が加わる。つまり、定められた部位に定められた張力を加えることができないため、コイルの生産性が悪くなる。 Here, when the coil is D-shaped when viewed from the direction in which the axis A of the protective frame 24 extends, that is, when the first portion 26 is linear, when the litz wire is wound around the first portion 26, the second portion 27 is used. The directed tension cannot be applied to the litz wire. Moreover, when the litz wire of the first portion 26 is wound, excessive tension is applied to the third portion 28 or the fourth portion 29 wound earlier. That is, since the specified tension cannot be applied to the specified portion, the productivity of the coil deteriorates.

本実施形態では、第１部分２６から第４部分２９は全て円弧状であり、コイル２５Ａ，２５Ｂには直線部分が無い。よって、直線部分（第１部分２６）で張力が過少になったり、直線部分の両端（第３部分２８又は第４部分２９）で張力が過多になることはない。そのため、定められた部位に所定の張力を加えてリッツ線（素線２５ａ）を巻回できる。よって、定められた形状のコイル２５Ａ，２５Ｂを確実に製造できるとともに、コイル２５Ａ，２５Ｂの生産性を向上できる。 In the present embodiment, the first portion 26 to the fourth portion 29 are all arcuate, and the coils 25A and 25B do not have straight portions. Therefore, the tension does not become excessive at both ends of the straight portion (first portion 26) or excessive at both ends of the straight portion (third portion 28 or fourth portion 29). Therefore, the litz wire (wire 25a) can be wound by applying a predetermined tension to the predetermined portion. Therefore, the coils 25A and 25B having a predetermined shape can be reliably manufactured, and the productivity of the coils 25A and 25B can be improved.

以上のように構成した本発明の炊飯器１０は、以下の特徴を有する。 The rice cooker 10 of the present invention configured as described above has the following features.

第１部分２６が炊飯鍋１５の底面部１６を局部的に加熱し、第２部分２７が炊飯鍋１５の側面部１７を局部的に加熱し、第３部分２８と第４部分２９が炊飯鍋１５の底面部１６から側面部１７にかけて局部的に加熱する。第１部分２６の第１曲率半径ｒ１は第２部分２７の第２曲率半径ｒ２よりも大きいため、炊飯鍋１５の底面部１６の加熱領域を広く確保できる。よって、加熱調理において重要な炊飯鍋１５の底面部１６側の加熱性を向上できる。しかも、コイル２５Ａ，２５Ｂには直線部分が無いため、生産性を向上できる。 The first part 26 locally heats the bottom surface 16 of the rice cooker 15, the second part 27 locally heats the side surface 17 of the rice cooker 15, and the third part 28 and the fourth part 29 heat the rice cooker. Locally heats from the bottom surface portion 16 to the side surface portion 17 of 15. Since the first radius of curvature r1 of the first portion 26 is larger than the second radius of curvature r2 of the second portion 27, a wide heating region of the bottom surface portion 16 of the rice cooking pot 15 can be secured. Therefore, the heatability of the bottom surface 16 side of the rice cooking pot 15, which is important in cooking, can be improved. Moreover, since the coils 25A and 25B do not have a straight portion, productivity can be improved.

第３部分２８及び第４部分２９の内周部２５ｂの厚みＴｃ１はそれぞれ、第３部分２８及び第４部分２９の外周部２５ｃの厚みＴｃ２よりも厚い。また、第３部分２８及び第４部分２９の厚みはそれぞれ、内周部２５ｂから外周部２５ｃに向けて次第に薄くなっている。よって、炊飯鍋１５の底面部１６側では、単位面積当たりの素線２５ａの数が側面部１７側の単位面積当たりの素線２５ａの数よりも多くなるため、加熱量を確保できる。また、炊飯鍋１５の側面部１７側では、単位面積当たりの素線２５ａの数は少なくなるが、コイル２５Ａ，２５Ｂを配置可能な範囲を拡張できるため、加熱領域を確保できる。しかも、炊飯鍋１５の側面部１７側では、素線２５ａの数の減少によってコイル２５Ａ，２５Ｂの柔軟性が向上するため、底壁２４ａから外周壁２４ｂまでの外面形状に対するフィット性を向上できる。 The thickness Tc1 of the inner peripheral portion 25b of the third portion 28 and the fourth portion 29 is thicker than the thickness Tc2 of the outer peripheral portion 25c of the third portion 28 and the fourth portion 29, respectively. Further, the thicknesses of the third portion 28 and the fourth portion 29 are gradually reduced from the inner peripheral portion 25b toward the outer peripheral portion 25c, respectively. Therefore, on the bottom surface 16 side of the rice cooking pot 15, the number of strands 25a per unit area is larger than the number of strands 25a per unit area on the side surface 17, so that the amount of heating can be secured. Further, on the side surface 17 side of the rice cooker 15, the number of strands 25a per unit area is small, but the range in which the coils 25A and 25B can be arranged can be expanded, so that a heating region can be secured. Moreover, on the side surface 17 side of the rice cooker 15, the flexibility of the coils 25A and 25B is improved by reducing the number of strands 25a, so that the fit to the outer surface shape from the bottom wall 24a to the outer peripheral wall 24b can be improved.

２個のコイル２５Ａ，２５Ｂを備え、これらが底壁２４ａの中央及びセンサ４１を通る基準線Ｌに対して対称に配置されている。よって、２個のコイル２５Ａ，２５Ｂによって炊飯鍋１５の底面部１６側を偏り無く加熱できる。また、１個のセンサ４１によって２個のコイル２５Ａ，２５Ｂによる炊飯鍋１５の加熱温度を偏りなく検出できる。 Two coils 25A and 25B are provided, and these are arranged symmetrically with respect to the center of the bottom wall 24a and the reference line L passing through the sensor 41. Therefore, the bottom surface 16 side of the rice cooking pot 15 can be heated evenly by the two coils 25A and 25B. Further, the heating temperature of the rice cooking pot 15 by the two coils 25A and 25B can be detected evenly by one sensor 41.

センサ４１に最も近接した第３部分２８又は第４部分２９とセンサ４１との間の隙間Ｓは、２０ｍｍ以下である。よって、コイル２５Ａ，２５Ｂによって加熱した炊飯鍋１５の温度をセンサ４１によって検出する際の応答性を向上できる。 The gap S between the sensor 41 and the third portion 28 or the fourth portion 29 closest to the sensor 41 is 20 mm or less. Therefore, the responsiveness when the temperature of the rice cooking pot 15 heated by the coils 25A and 25B is detected by the sensor 41 can be improved.

第１部分２６及び第２部分２７の厚みＴａ，Ｔｂはそれぞれ、内周部２５ｂから外周部２５ｃにかけて一様であり、第１部分２６を構成する素線２５ａの密度は、第２部分２７を構成する素線２５ａの密度よりも高い。よって、炊飯鍋１５の底面部１６における単位面積当たりの加熱量を確保できるとともに、炊飯鍋１５の側面部１７にける加熱領域を確保できる。 The thicknesses Ta and Tb of the first portion 26 and the second portion 27 are uniform from the inner peripheral portion 25b to the outer peripheral portion 25c, respectively, and the density of the strands 25a constituting the first portion 26 is the same as that of the second portion 27. It is higher than the density of the constituent strands 25a. Therefore, the amount of heating per unit area on the bottom surface 16 of the rice cooking pot 15 can be secured, and the heating region on the side surface portion 17 of the rice cooking pot 15 can be secured.

なお、本発明の炊飯器（調理器）１０は、前記実施形態の構成に限定されず、種々の変更が可能である。 The rice cooker (cooker) 10 of the present invention is not limited to the configuration of the above embodiment, and various changes can be made.

例えば、第１部分２６の厚みＴａと第２部分２７の厚みＴｂとは、それぞれ異なっていてもよいし、内周部２５ｂと外周部２５ｃで異なっていてもよい。第３部分２８の厚みと第４部分２９の厚みとは、それぞれ異なっていてもよし、内周部２５ｂと外周部２５ｃは同じであってもよい。 For example, the thickness Ta of the first portion 26 and the thickness Tb of the second portion 27 may be different from each other, or may be different between the inner peripheral portion 25b and the outer peripheral portion 25c. The thickness of the third portion 28 and the thickness of the fourth portion 29 may be different from each other, and the inner peripheral portion 25b and the outer peripheral portion 25c may be the same.

第１部分２６から第４部分２９の曲率半径、及びこれらを構成する素線２５ａの密度は、必要に応じて変更が可能である。特に、第３部分２８の曲率半径と第４部分２９の曲率半径とは、異なっていてもよい。 The radius of curvature of the first portion 26 to the fourth portion 29 and the density of the strands 25a constituting them can be changed as needed. In particular, the radius of curvature of the third portion 28 and the radius of curvature of the fourth portion 29 may be different.

コイルは、２個に限られず、保護枠２４の軸線Ａを中心として周方向に並べて３個以上配置されてもよい。この場合、センサ４１は、保護枠２４の底壁２４ａの中央に配置することが好ましい。 The number of coils is not limited to two, and three or more may be arranged so as to be arranged in the circumferential direction about the axis A of the protective frame 24. In this case, the sensor 41 is preferably arranged at the center of the bottom wall 24a of the protective frame 24.

前記実施形態では炊飯器１０を例に挙げて説明したが、有底筒状の収容部と、収容部の外面側に配置された複数のコイルとを備える調理器であれば、いずれでも適用可能であり、同様の作用および効果を得ることができる。 In the above embodiment, the rice cooker 10 has been described as an example, but any cooker having a bottomed tubular accommodating portion and a plurality of coils arranged on the outer surface side of the accommodating portion can be applied. It is possible to obtain the same action and effect.

１０…炊飯器（調理器）
１５…炊飯鍋（鍋）
１６…底面部
１７…側面部
１７ａ…第１部分
１７ｂ…第２部分
１７ｃ…第３部分
２０…炊飯器本体
２１…外装体
２２…収容部
２３…内胴
２４…保護枠
２４ａ…底壁
２４ｂ…外周壁
２４ｃ…第１部分
２４ｄ…第２部分
２４ｅ…取付部
２４ｆ…貫通孔
２４ｇ…突出部
２４ｈ…リブ
２４ｉ…ボス
２５…コイル
２５ａ…素線
２５ｂ…内周部
２５ｃ…外周部
２５ｄ…接続線
２５ｅ…接続線
２６…第１部分
２６ａ…第１端
２６ｂ…第２端
２７…第２部分
２７ａ…第１端
２７ｂ…第２端
２８…第３部分
２８ａ…中央部分
２９…第４部分
２９ａ…中央部分
３０…フェライトコア
３１…ホルダ
３５…蓋体
３６…ヒンジ接続部
３７…放熱板
３８…内蓋
３９…蓋ヒータ
４１…センサ
４２…センサ
４４…制御基板
４５…ホルダ
Ａ保護枠（収容部）の軸線
Ｌ基準線
Ｓ隙間
ｒ１第１部分の曲率半径
ｒ２第２部分の曲率半径
ｒ３第３部分の曲率半径
ｒ４第４部分の曲率半径
Ｔａ第１部分の厚み
Ｔｂ第２部分の厚み
Ｔｃ１第３部分及び第４部分の内周部の厚み
Ｔｃ２第３部分及び第４部分の外周部の厚み 10 ... Rice cooker (cooker)
15 ... Rice cooking pot (pot)
16 ... Bottom part 17 ... Side part 17a ... First part 17b ... Second part 17c ... Third part 20 ... Rice cooker body 21 ... Exterior body 22 ... Storage part 23 ... Inner body 24 ... Protective frame 24a ... Bottom wall 24b ... Outer wall 24c ... First part 24d ... Second part 24e ... Mounting part 24f ... Through hole 24g ... Protruding part 24h ... Rib 24i ... Boss 25 ... Coil 25a ... Wire 25b ... Inner circumference 25c ... Outer part 25d ... Connection line 25e ... Connection line 26 ... 1st part 26a ... 1st end 26b ... 2nd end 27 ... 2nd part 27a ... 1st end 27b ... 2nd end 28 ... 3rd part 28a ... Central part 29 ... 4th part 29a ... Central part 30 ... Ferrite core 31 ... Holder 35 ... Lid 36 ... Hinge connection 37 ... Heat dissipation plate 38 ... Inner lid 39 ... Lid heater 41 ... Sensor 42 ... Sensor 44 ... Control board 45 ... Holder A Protective frame (accommodation) Axis L Reference line S Gap r1 Radius of curvature of the first part r2 Radius of curvature of the second part r3 Radius of curvature of the third part r4 Radius of curvature of the fourth part Ta Thickness of the first part Tb Thickness of the second part Tc1 Third Thickness of the inner circumference of the part and the fourth part Tc2 Thickness of the outer circumference of the third part and the fourth part

Claims

An accommodating portion having a bottom wall and a tubular outer peripheral wall rising from the outer periphery of the bottom wall and accommodating a bottomed tubular pot,
A plurality of coils arranged side by side in the circumferential direction around the axis of the accommodating portion are provided on the outer surface side of the accommodating portion.
Each of the plurality of coils is annular and
Looking at the accommodating portion from the direction in which the axis of the accommodating portion extends, it is curved with a first radius of curvature so as to project toward the axis of the accommodating portion, and extends along the bottom wall so as to cross the bottom wall. The first part and
A second portion that curves with a second radius of curvature smaller than the first radius of curvature and extends along the outer peripheral wall,
An arcuate third portion connected to the first end of the first portion and the first end of the second portion in the circumferential direction of the accommodating portion.
A cooker having an arcuate fourth portion connected to a second end of the first portion and a second end of the second portion in the circumferential direction of the accommodating portion.

The cooker according to claim 1, wherein the ratio of the first radius of curvature to the second radius of curvature is 100% or more and 160% or less.

In the direction in which the axis of the accommodating portion extends, the thickness of the inner peripheral portion of the third portion and the thickness of the inner peripheral portion of the fourth portion are the thickness of the outer peripheral portion of the third portion and the outer circumference of the fourth portion, respectively. The cooker according to claim 1 or 2, which is thicker than the thickness of the portion.

The cooker according to claim 3, wherein the thickness of the third portion and the thickness of the fourth portion are gradually reduced from the inner peripheral portion to the outer peripheral portion, respectively.

The cooker according to any one of claims 1 to 4, further comprising only two of the coils.

A sensor that penetrates the outer peripheral wall and detects the temperature of the pot is provided.
The fifth aspect of the present invention, wherein the two coils are arranged symmetrically with respect to the center of the bottom wall and the reference line passing through the sensor when the accommodating portion is viewed from the direction in which the axis of the accommodating portion extends. Cooker.

The cooker according to claim 6, wherein the gap between the sensor and the third portion or the fourth portion closest to the sensor is 20 mm or less.

The thickness of the first portion and the thickness of the second portion in the direction in which the axis of the accommodating portion extends are uniform from the inner peripheral portion to the outer peripheral portion, respectively.
The cooker according to any one of claims 1 to 7, wherein the density of the strands constituting the first portion is higher than the density of the strands constituting the second portion.