JP2004242998A

JP2004242998A - Rice cooker

Info

Publication number: JP2004242998A
Application number: JP2003037876A
Authority: JP
Inventors: Norio Ikeda; 典生池田; Keiji Ishikawa; 啓治石川; Akihiro Shinabe; 晃宏品部; Atsushi Koma; 敦高麗; Yumiko Hirata; 由美子平田; Kuniyuki Nakanishi; 邦行中西; Yasuyuki Mimura; 泰幸三村
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2003-02-17
Filing date: 2003-02-17
Publication date: 2004-09-02
Anticipated expiration: 2023-02-17
Also published as: JP3757945B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rice cooker for cooking delicious rice by maintaining a high temperature in the pot after boiling process of rice without temporarily lowering temperature in the pot, so as to promote gelatinization. <P>SOLUTION: A steam pathway temperature detection means 11 controls temperature in a steam pathway 8 at a predetermined temperature, by heating the steam pathway 8. After a pot temperature detection means 5 detects that temperature has reached a predetermined level and the rice boiling process has completed, steam is generated through a steam generation section 38. In this way, after the rice boiling process is completed, steam generated in the steam generation section passes through the steam pathway where the temperature is over 100 °C. Therefore, a rice temperature can be raised without the lowering of temperature of steam and without the temporary lowering of rice temperature. Gelatinization of starch is promoted, and rice can be cooked deliciously. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、炊飯性能を向上させるために、水の沸点以上の蒸気を利用する炊飯器に関するものである。
【０００２】
【従来の技術】
一般的な家庭用の炊飯器においては、鍋内の米と水を加熱するために鍋底部に配置した鍋加熱手段が主であり、蓋内の加熱手段は鍋内の米、水の上方の空間を介するため、結果的に、補助的な加熱となる。よって、鍋内上層の米は加熱量が不足し、鍋内の米、水を均一な加熱をすることができなかった。
【０００３】
さらに、本来炊飯においては、水がほぼ無くなり米の流動性がなくなる、炊飯の最終工程である、蒸らし工程で、それまでの加熱を継続し、米澱粉の糊化を完成させることが、美味なる飯を炊くために必須であるが、この工程で、加熱を継続すると鍋底付近の米飯が焦げてしまうため加熱を弱めることが多かった。
【０００４】
加熱を弱めることに伴う糊化不足を防止し、炊飯性能を向上させるための手段としては、蓋体に高熱源である誘導加熱コイルを設けて鍋開口部の上方から米を加熱するようなものがあった（例えば、特許文献１、特許文献２参照）。
【０００５】
図６に、特許文献１の構成を示す。図６において、１０１は本体ケースで下面には支持脚１０２を有する底板１０３が固着されている。１０４は耐熱性を有するプラスチックスによって構成された保護枠で、上部周縁部に設けられたつば部１０５が本体ケース１の上面に固着されている。１０６は保護枠１０４の下底部に装着された底面加熱用誘導コイル、１０７は保護枠１０４の下方側部に設置された側面加熱用誘導コイルで、保護枠１０４に収容された磁性金属層をもった鍋１０８を前記底面加熱用誘導コイル１０６とによって加熱し、鍋１０８内の米と水との内容物を加熱調理するものである。１０９は保護枠４の底面の中心に設けられた貫通孔に装着された温度センサ、１１０はつまみ１１１を有する蓋体で、保護枠１０４の上端部のつば部１０５上に着脱自在に載置されており、耐熱性を有するプラスチックスによって構成された内カバー１１２を断熱材１１３を介して固着している。１１４は内カバー１１２にピン１２０によって着脱自在に装着された内蓋で、その周縁部は鍋１０８のつば部に載置し、鍋１０８を覆蓋するものである。１１５は保護枠１０４のつば部５の内面に設置された本体側上部誘導コイルで本体ケース１０１内の電源部（図示しない）に接続されている。
【０００６】
１１６は本体側上部誘導コイル１１５によって励磁される蓋体側誘導コイルで蓋体１１０内の本体側誘導コイル１１５に対向する部分に装着されており、この蓋体側誘導コイル１１６に励起された電流が誘導コイル１１９に流れ、誘導コイル１１９の磁束により磁性金属板で形成された加熱板１１７が誘導加熱され、鍋１０８内の上部よりの炊飯加熱または保温加熱ができるものである。
【０００７】
特許文献２についてもその基本構成は特許文献１と同様であるのでここでは詳細は省略する。
【０００８】
【特許文献１】
特許第２９８８０５０号公報
【特許文献２】
特開平６−６２９５６号公報
【０００９】
【発明が解決しようとする課題】
しかしながら、上記の従来の構成の炊飯器では、鍋内上層の米が直接、誘導加熱コイルの熱放射により加熱されることになるため、蒸らし工程においては、ごはんの水分が蒸発して乾燥するという現象が生じている。従って、鍋内の米飯全体が十分な炊飯性能を確保できる温度まで鍋上方から誘導加熱コイルで加熱すると、鍋上層では乾燥して逆に食味が落ちてしまうため、結局、十分な加熱が行えず、鍋内全体にわたっては食味は完全なものではなかった。
【００１０】
さらに、炊飯量が多いほど、加熱量を多くしなければならないにも拘わらず、炊飯量が多くなるほど、上層のごはんは誘導加熱コイルに接近するので乾燥しやすくなるため、加熱を弱めなければならないという矛盾を生じていた。
【００１１】
この第１の課題は、蒸気発生部と、蒸気発生部から鍋への蒸気経路とを設けて蒸気を鍋内に供給する炊飯器とすることにより解決することができる。
【００１２】
すなわち、大気圧下の水の沸点（１００℃）以上の過熱蒸気を鍋開口部上方から米に供給することにより、まず、蒸気が供給されるがゆえに飯の乾燥を伴わない、しかも、１００℃以下の蒸気供給では米粒表面に水が付着するに留まるが、１００℃以上の蒸気であるので、米の糊化を進行させるのに必要なエネルギーをもち、糊化を促進し、炊飯性能を向上させることができるものである。
【００１３】
さらに、炊飯量に拘わらず、最適な加熱量を設定できるものである。
【００１４】
しかしながら、上記の構成にした場合、新たに、第２の課題が生じる。
【００１５】
炊飯の最終工程である、蒸らし工程で、それまでの加熱を途絶えることなく、継続することが、糊化を促進させて、甘みのある美味しいごはんに仕上げる条件であるが、蒸気経路の温度が低いままで、蒸気発生部において蒸気を発生させると、蒸気経路部を蒸気が通過する間に、蒸気温度が下がって、鍋内に温度の低い蒸気を供給してしまい、ごはんの温度を下げてしまうことになり、蒸らし工程で、それまでの加熱の継続が途絶えてしまい、糊化の促進を妨げ、美味なるごはんを炊くことができないという課題がある。さらに、蒸気経路が結露し、結露水が蒸気経路に溜まり、腐敗し、鍋内に混入することもあり、不衛生であるという課題を生じていた。
【００１６】
本発明は、上記第２の課題をも解決するもので、上層のごはんを乾燥させることなく、鍋内に温度の高い蒸気を炊き上げ終了後すぐに供給して糊化を促進させて美味なるごはんを炊く炊飯器を提供することを目的とするものである。
【００１７】
【課題を解決するための手段】
前記目的を達成するために、鍋と、前記鍋を加熱する鍋加熱手段と、前記鍋の温度を検知する鍋温度検知手段と、蒸気を発生する蒸気発生部と、一端が前記蒸気発生部に連通接続され他端が鍋に開放される蒸気経路と、前記蒸気を加熱する蒸気加熱手段と、前記蒸気経路の温度を検知する蒸気経路温度検知手段とを備え、前記蒸気経路温度検知手段が所定温度を検知し、かつ、前記鍋温度検知手段が所定温度を検知した後直ちに、前記蒸気経路から前記鍋に蒸気を供給するものである。
【００１８】
これにより、上層のごはんを乾燥させることなく、また炊き上げ工程終了後鍋内の温度を下げずに、直ちに鍋内に温度の高い蒸気を供給することによって、鍋内温度を高温に維持し糊化を促進させて美味なるごはんを炊くことができる炊飯器となるものである。
【００１９】
【発明の実施の形態】
請求項１に記載の発明は、鍋と、前記鍋を加熱する鍋加熱手段と、前記鍋の温度を検知する鍋温度検知手段と、蒸気を発生する蒸気発生部と、一端が前記蒸気発生部に連通接続され他端が鍋に開放される蒸気経路と、前記蒸気を加熱する蒸気加熱手段と、前記蒸気経路の温度を検知する蒸気経路温度検知手段とを備え、前記蒸気経路温度検知手段が所定温度を検知し、かつ、前記鍋温度検知手段が所定温度を検知した後直ちに、前記蒸気経路から前記鍋に蒸気を供給する炊飯器とすることにより、炊き上げ工程終了後、蒸気発生部で発生した蒸気は１００℃以上の蒸気経路を通過することになるので、蒸気は温度下降せずに、すみやかに１００℃以上に上昇して鍋内に供給されるので、ご飯温度を一旦下げることなく、ごはんの温度を上昇させることができるので、でんぷんの糊化が促進され美味なるごはんを炊くことができる。
【００２０】
請求項２に記載の発明は、鍋と、前記鍋を加熱する鍋加熱手段と、前記鍋の温度を検知する鍋温度検知手段と、蒸気を発生する蒸気発生部と、一端が前記蒸気発生部に連通接続され他端が鍋に開放される蒸気経路と、前記鍋の開口部を覆う加熱板と、前記加熱板を加熱する鍋開口部加熱手段と、前記加熱板の温度を検知する加熱板温度検知手段とを備え、前記加熱板温度検知手段が所定温度を検知し、かつ、前記鍋温度検知手段が所定温度を検知した後直ちに、前記蒸気経路から前記鍋に蒸気を供給する炊飯器とすることにより、炊き上げ工程終了後、蒸気発生部で発生し蒸気経路を経て鍋内に供給された蒸気は、１００℃以上に加熱された加熱板によって加熱されるので、蒸気はすみやかに１００℃以上に上昇して、ご飯温度を一旦下げることなく、ごはんの温度を上昇させることができるので、でんぷんの糊化が促進され美味なるごはんを炊くことができる。
【００２１】
請求項３に記載の発明は、特に請求項１記載の発明において、鍋の開口部を覆う加熱板と、前記加熱板を加熱する鍋開口部加熱手段と、前記加熱板の温度を制御する加熱板温度検知手段とを備え、蒸気経路温度検知手段及び加熱板温度検知手段が所定温度を検知し、かつ、前記鍋温度検知手段が所定温度を検知した後直ちに、前記蒸気経路から前記鍋に蒸気を供給する炊飯器とすることにより、炊き上げ工程終了後、蒸気発生部で発生した蒸気は１００℃以上の蒸気経路を通過することになるので、蒸気はすみやかに１００℃以上に上昇して鍋内に供給され、１００℃以上に加熱された加熱板によって加熱されるので、蒸気温度はさらに上昇して、鍋内温度を下げることなく、ごはんの温度を上昇させることができるので、糊化の促進が一層強められさらに美味なるごはんを炊くことができる。
【００２２】
請求項４に記載の発明は、特に請求項１〜３のいずれか１項に記載の発明において、蒸気経路の鍋側先端に蒸気経路から鍋側にのみ蒸気を通す逆止弁を備えたもので、炊き上げ時、鍋内から発生する蒸気やおねばが蒸気経路に侵入して、蒸気経路内を汚すことはない。また、蒸気経路内への水分の侵入を防止できるので、蒸気経路内への水分滞留がないので、蒸気発生部で発生した蒸気が蒸気経路を通過するとき、蒸気の水分による温度下降を防止できる。
【００２３】
請求項５に記載の発明は、特に請求項４に記載の発明において、蒸気経路の鍋側先端開口部に設けた弁と、前記弁を前記蒸気経路を閉塞する方向に付勢するバイアスばねと、所定温度以上で前記弁を開口する方向に前記バイアスばねより大なる力で付勢する形状記憶合金検知ばねを前記蒸気経路内に備えたことにより、炊き上げ時は、鍋内から発生する蒸気は、蒸気経路の鍋側先端開口部に設けた弁がバイアスばねによって蒸気経路を閉塞する方向に付勢されて開口部を閉じているため、鍋内から発生する蒸気やおねばが蒸気経路に侵入して、蒸気経路内を汚すことはない。また、蒸気経路内への水分の侵入を防止できるので、蒸気経路内への水分滞留がないので、蒸気発生部で発生した蒸気が蒸気経路を通過するとき、蒸気の水分による温度下降を防止できる。さらに、蒸気発生部で発生した蒸気によって、形状記憶合金検知ばねの温度が上昇して、弁を開けるので、蒸気は蒸気経路を抵抗なくスムーズに通って鍋内に供給される。
【００２４】
【実施例】
以下、本発明の実施例について、図面を参照しながら説明する。
【００２５】
（実施例１）
図１は本発明の第１の実施例における炊飯器を示すものである。
図１において、１は炊飯器の本体を示し、着脱自在の鍋２を内装する。さらに鍋２の上面を覆う蓋３が開閉自在に設置されている。また鍋２を加熱する鍋加熱手段４と鍋２の温度を検知する鍋温度検知手段５を本体１内部に配置する。本体１内部には水タンク６を内装しており、水タンク６には水タンク加熱手段７を有し、水タンク６と水タンク加熱手段７により蒸気発生手段３８を構成する。さらに蒸気経路８により蒸気発生手段３８と鍋２の上面の一部が接続され、鍋２上面の開口部を蒸気孔９とする。
【００２６】
１０は蒸気経路を加熱する蒸気加熱手段であり、蒸気経路８の温度を制御する蒸気経路温度検知手段１１が蒸気経路８に当接して設けられている。
【００２７】
蒸気孔９には蒸気経路８の鍋側先端に蒸気経路８から鍋側にのみ蒸気を通すシリコーンゴム製の逆止弁１５を備えている。
【００２８】
以上のように構成された炊飯器について、以下その動作、作用を説明する。炊飯を行う米とその米量に対応する水を鍋２入れ、本体１の所定の状態に内装する。さらに本体１に設けられた水タンク６内に所定量の水を入れ、炊飯開始スイッチ（図示せず。）を使用者が操作すると、炊飯工程が実施される。炊飯工程は浸水、炊き上げ、蒸らしの各工程に大分されている。浸水工程においては、鍋温度検知手段５で鍋２の温度を米が吸水に適した温度（約６０℃）になるように鍋加熱手段４を制御する。所定の時間を経て米に水が吸水した後、浸水工程から炊き上げ工程に移行する。炊き上げ工程では、鍋加熱手段４によって、鍋２内の米と水の温度を急激に上昇させて、沸騰状態にする。
【００２９】
このとき蒸気孔９には蒸気経路８の鍋側先端に蒸気経路８から鍋側にのみ蒸気を通すシリコーンゴム製の逆止弁１５を備えているので、鍋２内で発生した蒸気やおねばが蒸気経路８に侵入しないので蒸気経路内は汚れない。
【００３０】
鍋温度検知手段５の温度が第１の所定の温度に到達したのち、蒸気経路８を蒸気加熱手段１０によって加熱する。蒸気経路８に当接して設けられている蒸気経路温度検知手段１１が蒸気経路８の温度を所定の温度（約１３０℃）で制御する。
【００３１】
鍋２底の水分がなくなって、鍋温度検知手段５の温度が１００℃を超えた第２の所定の温度になったことを検知すると、鍋加熱手段４による鍋２の加熱を止めて、炊き上げ工程を終えて、蒸らし工程になる。蒸らし工程になると、直ちに水タンク加熱手段７により水タンク６を加熱する。加熱された水タンク６内の水は沸騰し、発生した蒸気はすでに約１３０℃まで加熱された蒸気経路８を通って１３０℃付近まで温度上昇し、鍋２内に供給される。よって鍋内温度を下げることなく、ごはんの温度を上昇させることができるので、澱粉の糊化が促進され美味なるごはんを炊くことができる。
【００３２】
また、ごはんは１００℃以上の雰囲気にありながら蒸気が鍋２内に満ちているので、ごはんが乾燥することはない。
【００３３】
（実施例２）
図２は本発明の第２の実施例における炊飯器を示すものである。基本は実施例１と同じであるので同一部分には同一符号を付して説明を省略し、相違点についてのみ説明する。
【００３４】
この実施例は、実施例１より、蒸気経路８を加熱する蒸気加熱手段１０と蒸気経路８の温度を制御する蒸気経路温度検知手段１１をなくして、加熱板１２を加熱する鍋開口部加熱手段１３と加熱板１２の温度を制御する加熱板温度検知手段１４を加熱板１２に当接して設けたものである。
【００３５】
以上のように構成された炊飯器について、以下その動作、作用を説明する。炊飯を行う米とその米量に対応する水を鍋２入れ、本体１の所定の状態に内装する。さらに本体１に設けられた水タンク６内に所定量の水を入れ、炊飯開始スイッチ（図示せず。）を使用者が操作し、浸水工程が行われるのは実施例１と同じである。炊き上げ工程では、鍋加熱手段４によって、鍋２内の米と水の温度を急激に上昇させて、沸騰状態にする。
【００３６】
鍋温度検知手段５の温度が第１の所定の温度に到達したのち、加熱板１２を鍋開口部加熱手段１３によって加熱する。加熱板１２当接して設けられている加熱板温度検知手段１４が加熱板１２の温度を所定の温度（約１３０℃）で制御する。
【００３７】
鍋２底の水分がなくなって、鍋温度検知手段５の温度が１００℃を超えた第２の所定の温度になったことを検知すると、鍋加熱手段４による鍋２の加熱を止めて、炊き上げ工程を終えて、蒸らし工程になる。蒸らし工程になると、直ちに水タンク加熱手段７により水タンク６を加熱する。加熱された水タンク６内の水は沸騰し、発生した蒸気は蒸気経路８を通って鍋２内に供給される。鍋２内に供給された蒸気はすでに約１３０℃まで加熱された加熱板１２によって、１３０℃付近まで温度上昇しているので、鍋内は温度下降することなく、鍋２内のごはんはこの高温の蒸気で温度上昇し、澱粉の糊化が促進されて美味なるごはんになる。
【００３８】
なお、鍋温度検知手段５の温度が第１の所定の温度（１００℃）に到達してから鍋２底の水分がなくなって、鍋温度検知手段５の温度が１００℃を超えた第２の所定の温度になるまでの時間は炊飯量によってほぼ一定であり、かつ加熱板１２の温度を１００℃以上の所定の温度（約１３０℃）に上昇させる時間もほぼ一定であるので、加熱板１２の温度が１００℃以上の所定の温度（約１３０℃）に到達するすぐ後に鍋温度検知手段５の温度が１００℃を超えた第２の所定の温度になるように時間設定することによって、加熱板１２の温度が高いまま蒸気が供給されない時間を最小にできごはんの乾燥を防止できる。
【００３９】
なお、蒸らし工程の後半で、水タンク加熱手段７による水タンク６の加熱を止めて蒸気発生を終え、加熱板温度検知手段１４によって加熱板１２の温度を所定の温度（約１２０℃）に制御して、ごはん表面の余分な水分を飛ばすことにより、さらに美味なるごはんにすることができる。
【００４０】
（実施例３）
図３は本発明の第３の実施例における炊飯器を示すものである。基本は実施例１、実施例２と同じであるので同一部分には同一符号を付して説明を省略し、相違点についてのみ説明する。
【００４１】
この実施例は、実施例１に加えて、加熱板１２を加熱する鍋開口部加熱手段１３と加熱板１２の温度を制御する加熱板温度検知手段１４を加熱板１２に当接して設けたものである。
【００４２】
以上のように構成された炊飯器について、以下その動作、作用を説明する。炊飯を行う米とその米量に対応する水を鍋２入れ、本体１の所定の状態に内装する。さらに本体１に設けられた水タンク６内に所定量の水を入れ、炊飯開始スイッチ（図示せず。）を使用者が操作し、浸水工程が行われるのは実施例１と同じである。炊き上げ工程では、鍋加熱手段４によって、鍋２内の米と水の温度を急激に上昇させて、沸騰状態にする。
【００４３】
鍋温度検知手段５の温度が第１の所定の温度に到達したのち、蒸気経路８を蒸気加熱手段１０によって、加熱板１２を鍋開口部加熱手段１３によって加熱する。蒸気経路８に当接して設けられている蒸気経路温度検知手段１１が蒸気経路８の温度を１００℃以上の所定の温度（約１３０℃）で制御するとともに、加熱板１２当接して設けられている加熱板温度検知手段１４が加熱板１２の温度を１００℃以上の所定の温度（約１３０℃）で制御する。
【００４４】
鍋２底の水分がなくなって、鍋温度検知手段５の温度が１００℃を超えた第２の所定の温度になったことを検知すると、鍋加熱手段４による鍋２の加熱を止めて、炊き上げ工程を終えて、蒸らし工程になる。蒸らし工程になると、直ちに水タンク加熱手段７により水タンク６を加熱する。加熱された水タンク６内の水は沸騰し、発生した蒸気はすでに約１３０℃まで加熱された蒸気経路８を通って１３０℃付近まで温度上昇し、鍋２内に供給される。鍋２内に供給された蒸気はすでに約１３０℃まで加熱された加熱板１２によって、１３０℃までさらに温度上昇して、澱粉の糊化が一層促進されて美味なるごはんになる。
【００４５】
（実施例４）
図４、図５は本発明の第４の実施例における炊飯器の部分構成を示したものである。基本は実施例１〜３と同じであるので、同一部分は図を省略し、一部の同一部分には同一符号を付して説明を省略し、相違点についてのみ説明する。
【００４６】
この実施例は、蒸気経路８の鍋２側先端に弁１６が設けられ、この弁１６はバイアスばね１８で付勢されて蒸気経路８の先端の開口部１７を閉塞している。蒸気経路８内に備えられた形状記憶合金検知ばね１９は所定の温度（約９０℃）以上で形状記憶合金検知ばねより大なる力で弁１６をバイアスばね１８が弁１６を付勢する方向とは逆方向に付勢するものである。２０は例えばシリコーンゴム製のシールパッキンで、開口部１７の弁１６によるシールを補うものである。
【００４７】
以上のように構成された炊飯器について、以下その動作、作用を説明する。炊飯を行う米とその米量に対応する水を鍋２入れ、本体１の所定の状態に内装する。さらに本体１に設けられた水タンク６内に所定量の水を入れ、炊飯開始スイッチ（図示せず。）を使用者が操作し、浸水工程が行われるのは実施例１と同じである。炊き上げ工程では、鍋加熱手段４によって、鍋２内の米と水の温度を上昇させて、沸騰状態にする。このとき、水タンク６はまだ加熱されていないので、蒸気経路８には蒸気が来ないので、形状記憶合金検知ばね１９の温度は所定の温度（約９０℃）以下なので、バイアスばね１８の力が形状記憶合金検知ばね１９の力より大なので、弁１６は蒸気経路８の先端の開口部１７を閉塞している（図４）。
【００４８】
鍋内から発生する蒸気やおねばの蒸気経路内への侵入を防止するので、蒸気経路内がおねばで汚れることはない。また、蒸気経路内への水分の侵入を防止するるので、蒸気経路内への水分滞留がなく、蒸気発生部で発生した蒸気が蒸気経路を通過するとき、蒸気の水分による温度下降を防止できるので、鍋２内に高温の蒸気を供給でき、美味なるごはんを炊き上げることができる。
【００４９】
次に蒸らし工程になると、水タンク加熱手段７により水タンク６を加熱され水タンク６内の水は沸騰し、発生した蒸気は蒸気経路８を通る。このとき、蒸気は１００℃であるので、蒸気経路８内の形状記憶合金検知ばね１９の温度は所定の温度（９０℃）以上になり、バイアスばね１８の力より大になって、弁１６を開口して、蒸気は蒸気経路９の開口部１７から鍋２内に供給される（図５）。
【００５０】
蒸気は蒸気経路をゴム製の逆止弁のようにある圧力がかからないと開口しないものと異なり、蒸気による形状記憶合金検知ばね１９の温度上昇のみで弁１６が開口するので、抵抗なくスムーズに蒸気経路８を通って鍋内に供給される。
【００５１】
【発明の効果】
以上のように、本発明の炊飯器は、炊飯の蒸らし工程において、蒸気発生部で発生させた蒸気の温度をすみやかに高温にするので、鍋内温度を下げることなく、ごはんの温度を上昇させることができ、澱粉の糊化が促進され美味なるごはんを炊くことができる。
【図面の簡単な説明】
【図１】本発明の実施例１における炊飯器の断面図
【図２】本発明の実施例２における炊飯器の断面図
【図３】本発明の実施例３における炊飯器の断面図
【図４】本発明の実施例４における弁が閉塞時の炊飯器の部分断面図
【図５】本発明の実施例４における弁が開口時の炊飯器の部分断面図
【図６】従来の炊飯の断面図
【符号の説明】
２鍋
４鍋加熱手段
５鍋温度検知手段
８蒸気経路
１０蒸気加熱手段
１１蒸気経路温度検知手段
１２加熱板
１３鍋開口部加熱手段
１４加熱板温度検知手段
１５逆止弁
１６弁
１８バイアスばね
１９形状記憶合金検知ばね
３８蒸気発生手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rice cooker that utilizes steam having a boiling point higher than that of water to improve rice cooking performance.
[0002]
[Prior art]
In a general household rice cooker, the pot heating means arranged at the bottom of the pot to heat the rice and water in the pot is mainly used, and the heating means in the lid is for the rice in the pot, above the water. As a result of passing through the space, auxiliary heating results. Therefore, the heating amount of rice in the upper layer in the pot was insufficient, and the rice and water in the pot could not be heated uniformly.
[0003]
Furthermore, in rice cooking, water is almost completely lost and the fluidity of rice is lost. In the steaming step, which is the final step of rice cooking, heating up to that point is continued to complete the gelatinization of rice starch. Indispensable for cooking rice, if heating is continued in this step, the rice cooked near the bottom of the pot will burn, so heating is often weakened.
[0004]
Means to prevent insufficient gelatinization due to weakening of heating and improve rice cooking performance include heating the rice from above the pot opening by providing an induction heating coil, which is a high heat source, on the lid. (For example, see Patent Documents 1 and 2).
[0005]
FIG. 6 shows the configuration of Patent Document 1. In FIG. 6, reference numeral 101 denotes a main body case to which a bottom plate 103 having a support leg 102 is fixed on the lower surface. Reference numeral 104 denotes a protection frame made of heat-resistant plastics, and a flange 105 provided on an upper peripheral portion is fixed to an upper surface of the main body case 1. 106 is a bottom surface heating induction coil mounted on the lower bottom of the protection frame 104, 107 is a side surface heating induction coil installed on the lower side of the protection frame 104, and has a magnetic metal layer housed in the protection frame 104. The pot 108 is heated by the bottom-surface heating induction coil 106 to cook the contents of rice and water in the pot 108. Reference numeral 109 denotes a temperature sensor mounted in a through hole provided at the center of the bottom surface of the protection frame 4. Reference numeral 110 denotes a lid having a knob 111, which is removably mounted on the flange 105 at the upper end of the protection frame 104. An inner cover 112 made of heat-resistant plastic is fixed via a heat insulating material 113. Reference numeral 114 denotes an inner lid detachably mounted on the inner cover 112 by means of pins 120. The peripheral edge of the inner lid is placed on the flange of the pot 108 to cover the pot 108. Reference numeral 115 denotes a main body side upper induction coil installed on the inner surface of the flange portion 5 of the protection frame 104, which is connected to a power supply unit (not shown) in the main body case 101.
[0006]
Reference numeral 116 denotes a lid-side induction coil that is excited by the main-body-side upper induction coil 115 and is mounted on a portion of the lid 110 that faces the main-body-side induction coil 115, and a current excited by the lid-side induction coil 116 is induced. The heating plate 117, which flows through the coil 119 and is formed of a magnetic metal plate by the magnetic flux of the induction coil 119, is induction-heated, so that rice cooking or heat-retaining heating from above in the pot 108 can be performed.
[0007]
The basic configuration of Patent Literature 2 is the same as that of Patent Literature 1, and the details are omitted here.
[0008]
[Patent Document 1]
Japanese Patent No. 2988050 [Patent Document 2]
JP-A-6-62956
[Problems to be solved by the invention]
However, in the rice cooker having the above-mentioned conventional configuration, the rice in the upper layer in the pot is directly heated by the heat radiation of the induction heating coil, so that in the steaming step, the water in the rice is evaporated and dried. A phenomenon has occurred. Therefore, if the whole cooked rice in the pot is heated by the induction heating coil from the top of the pot to a temperature at which sufficient rice cooking performance can be ensured, the upper layer of the pot will dry and conversely lose its taste. The taste was not perfect throughout the pot.
[0010]
In addition, the higher the amount of cooked rice, the higher the amount of cooked rice, because the higher the amount of cooked rice, the closer the rice to the induction heating coil is, and the easier it is to dry, so the heating must be reduced. Was inconsistent.
[0011]
This first problem can be solved by providing a steam cooker that supplies steam into the pot by providing a steam generator and a steam path from the steam generator to the pot.
[0012]
That is, by supplying superheated steam having a boiling point (100 ° C.) or higher of water under atmospheric pressure to the rice from above the opening of the pot, firstly, the steam is supplied, so that the rice is not dried. In the following steam supply, water only adheres to the rice grain surface, but since it is steam of 100 ° C or more, it has the energy necessary to advance the gelatinization of rice, promotes gelatinization, and improves rice cooking performance That can be done.
[0013]
Furthermore, the optimum heating amount can be set regardless of the amount of cooked rice.
[0014]
However, in the case of the above configuration, a second problem newly occurs.
[0015]
In the steaming step, which is the final step of rice cooking, continuing heating without interruption is a condition for promoting gelatinization and finishing sweet and delicious rice, but the temperature of the steam path is low. Until now, when steam was generated in the steam generator, the steam temperature dropped while the steam passed through the steam path, and low-temperature steam was supplied into the pot, lowering the temperature of the rice. That is, in the steaming step, the continuation of the heating up to that point is interrupted, which hinders the promotion of gelatinization and has a problem that delicious rice cannot be cooked. Furthermore, dew condensation occurs in the steam path, and condensed water accumulates in the steam path, rots, and may be mixed into the pot, causing a problem of unsanitation.
[0016]
The present invention also solves the above second problem, and without drying the rice in the upper layer, the high temperature steam is cooked in the pan and supplied immediately after the completion of the cooking to promote the gelatinization to enhance the taste. It is intended to provide a rice cooker for cooking rice.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, a pot, a pot heating means for heating the pot, a pot temperature detecting means for detecting the temperature of the pot, a steam generating section for generating steam, and one end of the steam generating section A steam path communicating and connected to the other end of the pot, steam heating means for heating the steam, and steam path temperature detecting means for detecting a temperature of the steam path; Immediately after the temperature is detected and the pan temperature detecting means detects the predetermined temperature, steam is supplied from the steam path to the pan.
[0018]
As a result, high-temperature steam is immediately supplied into the pot without drying the rice in the upper layer and without lowering the temperature in the pot after the cooking process, so that the temperature in the pot is maintained at a high temperature and the glue is maintained. It is a rice cooker that can cook delicious rice by promoting the conversion.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 is a pan, a pan heating unit that heats the pan, a pan temperature detection unit that detects the temperature of the pan, a steam generation unit that generates steam, and one end of the steam generation unit. A steam path that is connected to the other end and is open to the pan, a steam heating means for heating the steam, and a steam path temperature detecting means for detecting a temperature of the steam path, wherein the steam path temperature detecting means is provided. A predetermined temperature is detected, and immediately after the pan temperature detecting means detects the predetermined temperature, by using a rice cooker that supplies steam to the pan from the steam path, after the cooking step, the steam generating unit Since the generated steam passes through the steam path of 100 ° C or higher, the steam does not decrease in temperature, but immediately rises to 100 ° C or higher and is supplied into the pot, so that the temperature of the rice is not lowered once. Raise the temperature of the rice Since it is Rukoto, it is possible to cook a delicious Naru rice is promoted gelatinized starch.
[0020]
The invention according to claim 2 is a pan, a pan heating unit that heats the pan, a pan temperature detection unit that detects the temperature of the pan, a steam generation unit that generates steam, and one end of the steam generation unit. A heating path that is connected to the other end and is open to the pan, a heating plate that covers the opening of the pan, a pan opening heating unit that heats the heating plate, and a heating plate that detects the temperature of the heating plate. A rice cooker comprising a temperature detection unit, wherein the heating plate temperature detection unit detects a predetermined temperature, and immediately after the pan temperature detection unit detects the predetermined temperature, a rice cooker that supplies steam to the pan from the steam path. After the cooking process, the steam generated in the steam generating section and supplied to the pot through the steam path after the cooking process is heated by a heating plate heated to 100 ° C. or more, so that the steam is quickly heated to 100 ° C. Rise above and lower the rice temperature once And no, it is possible to raise the temperature of the rice, it is possible to cook delicious Naru rice is promoted gelatinization of starch.
[0021]
According to a third aspect of the present invention, in particular, in the first aspect of the present invention, a heating plate for covering the opening of the pan, a pan opening heating means for heating the heating plate, and heating for controlling the temperature of the heating plate. Plate temperature detecting means, wherein the steam path temperature detecting means and the heating plate temperature detecting means detect a predetermined temperature, and immediately after the pan temperature detecting means detects the predetermined temperature, steam flows from the steam path to the pan. After the cooking process, the steam generated in the steam generator passes through a steam path of 100 ° C. or more, so that the steam quickly rises to 100 ° C. or more and the pot The steam is heated by a heating plate heated to 100 ° C. or more, so that the steam temperature further rises and the temperature of the rice can be increased without lowering the temperature in the pan, so that the gelatinization Further promotion It is possible to cook the order is Naru further delicious rice.
[0022]
According to a fourth aspect of the present invention, in particular, in any one of the first to third aspects of the present invention, a check valve that allows steam to pass only from the steam path to the pot side is provided at the tip of the steam path on the pot side. At the time of cooking, there is no possibility that steam or rice generated from the pot enters the steam path and contaminates the steam path. In addition, since the invasion of moisture into the steam path can be prevented, there is no water retention in the steam path, so that when the steam generated in the steam generating section passes through the steam path, the temperature drop due to the moisture of the steam can be prevented. .
[0023]
According to a fifth aspect of the present invention, in particular, in the invention of the fourth aspect, a valve provided at a pot-side end opening of the steam path, and a bias spring for urging the valve in a direction to close the steam path. By providing a shape memory alloy detecting spring in the steam path that urges the valve at a predetermined temperature or higher with a force larger than the bias spring in a direction to open the valve, the steam generated from the pot during cooking is provided. Because the valve provided at the pot-side tip opening of the steam path is urged in the direction to close the steam path by the bias spring and closes the opening, the steam and sardine generated from inside the pot pass through the steam path. It does not penetrate and contaminate the steam path. In addition, since the invasion of moisture into the steam path can be prevented, there is no water retention in the steam path, so that when the steam generated in the steam generating section passes through the steam path, the temperature drop due to the moisture of the steam can be prevented. . Further, the temperature of the shape memory alloy detection spring rises due to the steam generated in the steam generating section, and the valve is opened, so that the steam is smoothly passed through the steam path without resistance to be supplied into the pot.
[0024]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0025]
(Example 1)
FIG. 1 shows a rice cooker according to a first embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a rice cooker main body, in which a detachable pot 2 is provided. Further, a lid 3 that covers the upper surface of the pan 2 is installed to be freely opened and closed. A pot heating means 4 for heating the pot 2 and a pot temperature detecting means 5 for detecting the temperature of the pot 2 are arranged inside the main body 1. A water tank 6 is provided inside the main body 1. The water tank 6 has a water tank heating means 7, and the water tank 6 and the water tank heating means 7 constitute a steam generating means 38. Further, the steam path 8 connects the steam generating means 38 to a part of the upper surface of the pan 2, and the opening on the upper surface of the pan 2 is used as a steam hole 9.
[0026]
Reference numeral 10 denotes steam heating means for heating the steam path, and a steam path temperature detecting means 11 for controlling the temperature of the steam path 8 is provided in contact with the steam path 8.
[0027]
The steam hole 9 is provided with a check valve 15 made of silicone rubber that allows steam to pass only from the steam path 8 to the pot side at the pot-side end of the steam path 8.
[0028]
The operation and operation of the rice cooker configured as described above will be described below. Rice to be cooked and water corresponding to the amount of the rice are placed in the pot 2 and the main body 1 is housed in a predetermined state. Further, when a predetermined amount of water is put into a water tank 6 provided in the main body 1 and a user operates a rice cook start switch (not shown), a rice cook process is performed. The rice cooking process is largely divided into submersion, cooking and steaming. In the water immersion step, the pot heating means 4 is controlled by the pot temperature detecting means 5 so that the temperature of the pot 2 becomes a temperature (about 60 ° C.) suitable for water absorption of rice. After water is absorbed into the rice after a predetermined time, the process shifts from the flooding process to the cooking process. In the cooking step, the temperature of the rice and water in the pan 2 is rapidly increased by the pan heating means 4 to bring the rice and water into a boiling state.
[0029]
At this time, since the steam hole 9 is provided with a check valve 15 made of silicone rubber which allows steam to pass only from the steam path 8 to the pot side at the tip of the steam path 8 on the pot side, the steam generated in the pot 2 Does not enter the steam path 8, so that the inside of the steam path is not contaminated.
[0030]
After the temperature of the pot temperature detecting means 5 reaches the first predetermined temperature, the steam path 8 is heated by the steam heating means 10. The steam path temperature detecting means 11 provided in contact with the steam path 8 controls the temperature of the steam path 8 at a predetermined temperature (about 130 ° C.).
[0031]
When it is detected that the bottom of the pan 2 has run out of water and the temperature of the pan temperature detecting means 5 has reached a second predetermined temperature exceeding 100 ° C., the heating of the pan 2 by the pan heating means 4 is stopped, and cooking is completed. After the raising process, a steaming process is performed. In the steaming step, the water tank 6 is immediately heated by the water tank heating means 7. The water in the heated water tank 6 boils, and the generated steam rises to near 130 ° C. through the steam path 8 already heated to about 130 ° C., and is supplied into the pot 2. Therefore, the temperature of the rice can be increased without lowering the temperature in the pot, so that the gelatinization of the starch is promoted and the delicious rice can be cooked.
[0032]
Moreover, the steam is filled in the pot 2 while the rice is in an atmosphere of 100 ° C. or higher, so that the rice does not dry.
[0033]
(Example 2)
FIG. 2 shows a rice cooker according to a second embodiment of the present invention. Since the basics are the same as those of the first embodiment, the same portions are denoted by the same reference numerals, and description thereof will be omitted. Only different points will be described.
[0034]
This embodiment is different from the first embodiment in that there is no steam heating means 10 for heating the steam path 8 and a steam path temperature detecting means 11 for controlling the temperature of the steam path 8, and a pan opening heating means for heating the heating plate 12. A heating plate temperature detecting means 14 for controlling the temperatures of the heating plate 13 and the heating plate 12 is provided in contact with the heating plate 12.
[0035]
The operation and operation of the rice cooker configured as described above will be described below. Rice to be cooked and water corresponding to the amount of the rice are placed in the pot 2 and the main body 1 is housed in a predetermined state. Further, the same operation as in the first embodiment is performed in which a predetermined amount of water is put into a water tank 6 provided in the main body 1 and a rice cook start switch (not shown) is operated by a user to perform a water immersion step. In the cooking step, the temperature of the rice and water in the pan 2 is rapidly increased by the pan heating means 4 to bring the rice and water into a boiling state.
[0036]
After the temperature of the pot temperature detecting means 5 reaches the first predetermined temperature, the heating plate 12 is heated by the pot opening heating means 13. The heating plate temperature detecting means 14 provided in contact with the heating plate 12 controls the temperature of the heating plate 12 at a predetermined temperature (about 130 ° C.).
[0037]
When it is detected that the bottom of the pan 2 has run out of water and the temperature of the pan temperature detecting means 5 has reached a second predetermined temperature exceeding 100 ° C., the heating of the pan 2 by the pan heating means 4 is stopped, and cooking is completed. After the raising process, a steaming process is performed. In the steaming step, the water tank 6 is immediately heated by the water tank heating means 7. The water in the heated water tank 6 boils, and the generated steam is supplied into the pot 2 through the steam path 8. The temperature of the steam supplied into the pan 2 is raised to about 130 ° C. by the heating plate 12 already heated to about 130 ° C. The temperature rises due to the steam, and the gelatinization of the starch is promoted, resulting in delicious rice.
[0038]
After the temperature of the pot temperature detecting means 5 reaches the first predetermined temperature (100 ° C.), the bottom of the pot 2 is depleted of moisture, and the temperature of the pot temperature detecting means 5 exceeds 100 ° C. The time required to reach the predetermined temperature is substantially constant depending on the amount of cooked rice, and the time required to raise the temperature of the heating plate 12 to a predetermined temperature of 100 ° C. or higher (about 130 ° C.) is also substantially constant. By setting the time so that the temperature of the pan temperature detecting means 5 becomes the second predetermined temperature exceeding 100 ° C. immediately after the temperature of the pan reaches a predetermined temperature (about 130 ° C.) of 100 ° C. or higher, Drying of rice can be prevented by minimizing the time during which steam is not supplied while the temperature of the plate 12 is high.
[0039]
In the latter half of the steaming step, the heating of the water tank 6 by the water tank heating means 7 is stopped to terminate the steam generation, and the temperature of the heating plate 12 is controlled to a predetermined temperature (about 120 ° C.) by the heating plate temperature detecting means 14. Then, by removing excess water on the rice surface, the rice can be made more delicious.
[0040]
(Example 3)
FIG. 3 shows a rice cooker according to a third embodiment of the present invention. Since the basics are the same as those of the first and second embodiments, the same portions are denoted by the same reference numerals, and description thereof will be omitted. Only different points will be described.
[0041]
In this embodiment, in addition to the first embodiment, a pan opening heating means 13 for heating the heating plate 12 and a heating plate temperature detecting means 14 for controlling the temperature of the heating plate 12 are provided in contact with the heating plate 12. It is.
[0042]
The operation and operation of the rice cooker configured as described above will be described below. Rice to be cooked and water corresponding to the amount of the rice are placed in the pot 2 and the main body 1 is housed in a predetermined state. Further, the same operation as in the first embodiment is performed in which a predetermined amount of water is put into a water tank 6 provided in the main body 1 and a rice cook start switch (not shown) is operated by a user to perform a water immersion step. In the cooking step, the temperature of the rice and water in the pan 2 is rapidly increased by the pan heating means 4 to bring the rice and water into a boiling state.
[0043]
After the temperature of the pot temperature detecting means 5 reaches the first predetermined temperature, the steam path 8 is heated by the steam heating means 10 and the heating plate 12 is heated by the pot opening heating means 13. The steam path temperature detecting means 11 provided in contact with the steam path 8 controls the temperature of the steam path 8 at a predetermined temperature of 100 ° C. or more (about 130 ° C.), and is provided in contact with the heating plate 12. The heating plate temperature detecting means 14 controls the temperature of the heating plate 12 at a predetermined temperature of 100 ° C. or more (about 130 ° C.).
[0044]
When it is detected that the bottom of the pan 2 has run out of water and the temperature of the pan temperature detecting means 5 has reached a second predetermined temperature exceeding 100 ° C., the heating of the pan 2 by the pan heating means 4 is stopped, and cooking is completed. After the raising process, a steaming process is performed. In the steaming step, the water tank 6 is immediately heated by the water tank heating means 7. The water in the heated water tank 6 boils, and the generated steam rises to near 130 ° C. through the steam path 8 already heated to about 130 ° C., and is supplied into the pot 2. The temperature of the steam supplied into the pot 2 is further increased to 130 ° C. by the heating plate 12 already heated to about 130 ° C., and the gelatinization of the starch is further promoted, resulting in a delicious rice.
[0045]
(Example 4)
FIGS. 4 and 5 show a partial configuration of a rice cooker according to a fourth embodiment of the present invention. Since the basics are the same as those of the first to third embodiments, the same parts are omitted in the drawings, the same parts are denoted by the same reference numerals, and the description thereof is omitted.
[0046]
In this embodiment, a valve 16 is provided at the tip of the steam path 8 on the pot 2 side, and the valve 16 is biased by a bias spring 18 to close the opening 17 at the tip of the steam path 8. The shape memory alloy detecting spring 19 provided in the steam path 8 operates the valve 16 with a force greater than the shape memory alloy detecting spring at a predetermined temperature (about 90 ° C.) or higher and the direction in which the bias spring 18 urges the valve 16. Urges in the opposite direction. Reference numeral 20 denotes a seal packing made of, for example, silicone rubber, which supplements the sealing of the opening 17 by the valve 16.
[0047]
The operation and operation of the rice cooker configured as described above will be described below. Rice to be cooked and water corresponding to the amount of the rice are placed in the pot 2 and the main body 1 is housed in a predetermined state. Further, the same operation as in the first embodiment is performed in which a predetermined amount of water is put into a water tank 6 provided in the main body 1 and a rice cook start switch (not shown) is operated by a user to perform a water immersion step. In the cooking step, the temperature of the rice and water in the pan 2 is raised by the pan heating means 4 to bring the rice and the water into a boiling state. At this time, since the water tank 6 has not been heated yet, no steam comes to the steam path 8, and the temperature of the shape memory alloy detecting spring 19 is lower than a predetermined temperature (about 90 ° C.). Is greater than the force of the shape memory alloy detection spring 19, the valve 16 closes the opening 17 at the tip of the steam path 8 (FIG. 4).
[0048]
Since the steam generated from the pot and the rice cake are prevented from entering the steam channel, the steam channel is not contaminated with the rice cake. In addition, since moisture is prevented from entering the steam path, there is no water retention in the steam path, and when the steam generated in the steam generating section passes through the steam path, a decrease in temperature due to the moisture of the steam can be prevented. Therefore, high-temperature steam can be supplied into the pan 2, and delicious rice can be cooked.
[0049]
Next, in the steaming step, the water tank 6 is heated by the water tank heating means 7, the water in the water tank 6 boils, and the generated steam passes through the steam path 8. At this time, since the temperature of the steam is 100 ° C., the temperature of the shape memory alloy detecting spring 19 in the steam path 8 becomes equal to or higher than a predetermined temperature (90 ° C.), becomes larger than the force of the bias spring 18, and the valve 16 is opened. Upon opening, steam is supplied into the pot 2 from the opening 17 of the steam path 9 (FIG. 5).
[0050]
Unlike a rubber check valve which does not open the steam path unless a certain pressure is applied to the steam path, the valve 16 opens only by the temperature rise of the shape memory alloy detection spring 19 due to the steam, so that the steam flows smoothly without resistance. It is fed into the pot through path 8.
[0051]
【The invention's effect】
As described above, the rice cooker of the present invention raises the temperature of rice without lowering the temperature in the pot because the temperature of the steam generated in the steam generating section is quickly raised in the steaming step of the cooked rice. This promotes the gelatinization of starch and makes it possible to cook delicious rice.
[Brief description of the drawings]
1 is a sectional view of a rice cooker according to a first embodiment of the present invention; FIG. 2 is a sectional view of a rice cooker according to a second embodiment of the present invention; FIG. 3 is a sectional view of a rice cooker according to a third embodiment of the present invention; 4 is a partial cross-sectional view of the rice cooker when the valve is closed according to the fourth embodiment of the present invention. FIG. 5 is a partial cross-sectional view of the rice cooker when the valve is open according to the fourth embodiment of the present invention. Cross-sectional view [Description of symbols]
2 Pot 4 Pot heating means 5 Pot temperature detecting means 8 Steam path 10 Steam heating means 11 Steam path temperature detecting means 12 Heating plate 13 Pot opening heating means 14 Heating plate temperature detecting means 15 Check valve 16 Valve 18 Bias spring 19 Shape Memory alloy detection spring 38 Steam generation means

Claims

A pan, a pan heating means for heating the pan, a pan temperature detecting means for detecting the temperature of the pan, a steam generator for generating steam, and one end connected to the steam generator and the other end connected to the pan. A steam path to be opened, a steam heating means for heating the steam, and a steam path temperature detecting means for detecting a temperature of the steam path, wherein the steam path temperature detecting means detects a predetermined temperature, and A rice cooker for supplying steam to the pot from the steam path immediately after the pot temperature detecting means detects a predetermined temperature.

A pan, a pan heating means for heating the pan, a pan temperature detecting means for detecting the temperature of the pan, a steam generator for generating steam, and one end connected to the steam generator and the other end connected to the pan. A heating plate that covers the opening of the pot, a heating unit that heats the heating plate, a heating unit that heats the heating plate, and a heating plate temperature detection unit that detects the temperature of the heating plate. A rice cooker for supplying steam from the steam path to the pot immediately after the plate temperature detecting means detects the predetermined temperature and the pan temperature detecting means detects the predetermined temperature.

A heating plate for covering the opening of the pot, a heating means for heating the heating plate, and a heating plate temperature detecting means for controlling the temperature of the heating plate; a steam path temperature detecting means and a heating plate temperature detecting means; 2. The rice cooker according to claim 1, wherein the means detects a predetermined temperature, and immediately after the pan temperature detecting means detects the predetermined temperature, steam is supplied to the pan from the steam path.

The rice cooker according to any one of claims 1 to 3, further comprising a check valve at the tip of the steam path on the pot side, the check valve passing steam only from the steam path to the pot.

A valve provided at the pot-side end opening of the steam path, a bias spring for urging the valve in a direction to close the steam path, and a force greater than the bias spring in a direction to open the valve at a predetermined temperature or higher. The rice cooker according to claim 4, further comprising a shape memory alloy detection spring biased in the steam path in the steam path.