JP3799655B2

JP3799655B2 - Vending machine cooling system

Info

Publication number: JP3799655B2
Application number: JP10376996A
Authority: JP
Inventors: 晃菅原
Original assignee: Fuji Electric Retail Systems Co Ltd
Current assignee: Fuji Electric Retail Systems Co Ltd
Priority date: 1996-03-29
Filing date: 1996-03-29
Publication date: 2006-07-19
Anticipated expiration: 2016-03-29
Also published as: JPH09270063A; TW338789B; KR970067001A; KR100199329B1

Description

【０００１】
【発明の属する技術分野】
本発明は、缶入飲料等の商品を販売する自動販売機の冷却装置に関する。
【０００２】
【従来の技術】
従来、缶入飲料等の商品を販売する自動販売機の冷却装置としては、本出願人による特願平７−４１５６（以下、先願１という）が提案されている。この先願１においては、図８に示すような圧縮機１０１、凝縮器１０２、電子膨張弁１０３、ディストリビュータ１０４、電磁弁１０５ａ〜１０５ｃ、蒸発器１０６ａ〜１０６ｃ、アキュームレータ１０７等を冷媒配管１０８により閉回路状に連結して冷凍回路を構成する冷却装置１００が示されている。
【０００３】
各蒸発器１０６ａ〜１０６ｃは断熱隔壁で区画された３基の商品収納庫（不図示）内に設けられており、蒸発器１０６ａ，１０６ｂが設けられた２基の商品収納庫は冷却専用に割り当てられ、蒸発器１０６ｃが設けられた１基の商品収納庫は冷却／加熱両用に割り当てられている。また各蒸発器１０６ａ〜１０６ｃには各蒸発器１０６ａ〜１０６ｃ内の温度ＴＥａ〜ＴＥｃを検出する温度センサ１０９ａ〜１０９ｃが設けられており、この温度センサ１０９ａ〜１０９ｃからの出力信号がコントローラ１１０に入力される。また、コントローラ１１０からの制御信号により電磁弁１０５ａ〜１０５ｃと電子膨張弁１０３とがその開閉を制御される。冷媒配管１０８中にはフレオン等の冷媒が封入されており、冷凍回路内を循環している。
【０００４】
この冷却装置１００では、加熱用に当てられて不使用だった蒸発器１０６ｃの運転を再会する場合に、冷媒が他の蒸発器１０６ａ，１０６ｂ側に多く流れて蒸発器１０６ｃの冷却が進まない状態が発生する。これを解消するために、コントローラ１１０は、各蒸発器１０６ａ〜１０６ｃ内の温度ＴＥａ〜ＴＥｃを温度センサ１０９ａ〜１０９ｃで検出して、各蒸発器間の温度差△Ｔｉｊが、所定値△Ｔｏよりも大きいか否かを判定する。この判定がＹＥＳのときはコントローラ１１０は一番冷却されている（最低温度の）蒸発器１０６を決定して、この蒸発器１０６への冷媒供給を停止するべく、その対応する電磁弁１０５を所定時間、閉状態にする。そして、所定時間経過後に各蒸発器間の温度差△Ｔｉｊをチェックして、通常の制御か上記の最低温度の蒸発器１０６への冷媒供給を停止する制御を行う。
【０００５】
また、別の自動販売機の冷却装置としては、本出願人による特願平７−２２１９９（以下、先願２という）が提案されている。この先願２においては、図８の構成において温度センサを蒸発器内ではなく蒸発器が設けられた３基の商品収納庫内に設けて、この商品収納庫内の温度ＴＲを検出する。
【０００６】
そして、冷却運転時にコントローラ１１０は、まず電磁弁１０５の開いている数をチェックして、電磁弁１０５が２基以上開いていときは電子膨張弁１０３の開度を１６０パルス数分に、開いている電磁弁１０５が１基以下のときは電子膨張弁１０３の開度を８０パルス数分に制御する。また、全電磁弁１０５が開いているときには上記商品収納庫内の温度ＴＲをチェックして一番高い庫内温度（最高庫内温度）を検出してＲＯＭテーブルを参照し、この値に応じて電子膨張弁１０３の開度をさらに補正する制御を行っている。
【０００７】
さらに、別の自動販売機の冷却装置としては、本出願人による特願平７−２２２０１（以下、先願３という）が提案されている。この先願３においては、図８の圧縮機１０１吸い込み側の冷媒配管１０８ａ〜１０８ｄの配管構成を変えることにより配管抵抗や圧損を変化させたり、または各蒸発器１０６自体の容量を変えて各蒸発器１０６の冷却能力に差を生じさせている。これにより、容量が異なる複数の商品収納庫を備える自動販売機において、各蒸発器１０６が全て運転しているときに均一に冷却効果が得られるように構成されている。
【０００８】
【発明が解決しようとする課題】
しかしながら上記先願３の技術においては、配管系の配管抵抗や圧損を変えたり蒸発器自体の容量を変えて、容量が異なる、言い換えれば冷却負荷が異なる複数の商品収納庫を均一に冷却できるようにしているが、自動販売機内において使用される配管系の取り回しの変更には限界があり、また配管の径サイズの変更も自由度が低い。すなわち、配管はあまり太くはできず、逆に細くなり過ぎると圧損や冷媒のつまりを生じる。同様に、蒸発器自体の容量を変える方法もコストやサイズ上の限界がある。このため、サイズ変更以外の方法で、冷却負荷が異なる複数の商品収納庫を均一に冷却できる自動販売機が望まれている。
【０００９】
この問題を解決するために冷却負荷が異なる複数の商品収納庫を備えた自動販売機に上記先願１の技術を応用した場合、先願１の技術は複数の商品収納庫の容量が異なる場合について考慮していないので、例えば電源投入時において急速冷却した後に最低温度の蒸発器への冷媒供給を停止した場合、運転中の他の蒸発器に冷媒が流れ込み過ぎてしまうことがある。このため、冷媒が流れ込み過ぎた蒸発器においては、冷媒がうまく気化しないために蒸発器の蒸発温度が高くなり、結果として商品収納庫の冷却が進まなくなるという問題点が生じる。
【００１０】
これを解消するには、上記先願１の技術に先願２の技術を組み合わせて最低温度の蒸発器への冷媒供給を停止したとき運転中の他の蒸発器に冷媒が流れ込み過ぎないようにすることが考えられる。しかし、先願２は開状態の電磁弁数に応じて電子膨張弁の開度を決定した後、全電磁弁が開状態になったときにさらに電子膨張弁を開くように補正するものなので、電源投入時のように急速冷却したいときには電子膨張弁の補正量が適切ではなく、冷却速度が遅くなってしまうという問題点があった。
【００１１】
本発明は上記課題を解決するためになされたもので、容量が異なる複数の商品収納庫を備える自動販売機においても、各蒸発器が全て運転しているとき例えば電源投入直後の運転時に、蒸発器の蒸発温度が高くなったり冷却速度が遅くなったりすることなく、効率的かつ均一に冷却効果が得られる自動販売機の冷却装置を提供することを目的とする。
【００１２】
【課題を解決するための手段】
請求項１の発明は、複数の商品収納庫の各々に冷凍回路の一部を構成する蒸発器を配置し、蒸発器に冷媒を送り蒸発器内で冷媒を蒸発させることにより複数の商品収納庫を独立して冷却するように構成された自動販売機の冷却装置において、各蒸発器の入口側冷媒配管に開閉可能に設けられた蒸発器用弁と、蒸発器用弁の上流側に開度調整可能に設けられた電子膨張弁と、各商品収納庫内及びこれに対応する蒸発器内の少なくとも一方の温度を検出する温度センサと、各温度センサの検出温度に基づき各蒸発器用弁の開閉を決定し、この決定した各蒸発器用弁の開閉に応じて電子膨張弁の開度を決定する制御手段とを備え、この制御手段は、各蒸発器用弁が全て開状態のときに、検出温度における最低温度と最高温度の差の絶対値が、所定値以上か否かを判定する判定手段と、判定の結果が前記所定値未満の場合は、最高温度に基づき先に決定した電子膨張弁の開度に第１補正量を加えて補正する第１開度補正手段と、判定の結果が所定値以上の場合は、最低温度に対応する蒸発器用弁を閉じて、最高温度に基づき先に決定した電子膨張弁の開度に第１補正量より小さい第２補正量を加えて補正する第２開度補正手段とを備えている。
【００１３】
このように各蒸発器用弁が全て開状態のときに、検出温度の最低温度と最高温度の差の絶対値が所定値以上か否かを判定して、判定の結果が所定値未満の場合は、最高温度に基づき先に決定した電子膨張弁の開度に第１補正量を加えて補正するので、特定の商品収納庫のみが冷却されたりすることがなく全商品収納庫を均一かつ急速に冷却できる。さらに、判定の結果が所定値以上の場合は、最低温度に対応する蒸発器用弁を閉じて最高温度に基づき、先に決定した電子膨張弁の開度に第１補正量より小さい第２補正量を加えて補正するので、残りの蒸発器に冷媒が多く流れ過ぎず、全商品収納庫を均一かつ急速に冷却できる。従って、この自動販売機によれば蒸発器が全て運転しているとき例えば電源投入直後の運転時にも効率的かつ均一に商品を冷却できる。
【００１４】
また、上記構成において制御手段は、判定結果が所定値以上の場合には最低温度の蒸発器用弁の閉状態を第１所定時間維持し、第１所定時間経過後に最低温度部位の蒸発器用弁を開くと共に、第２所定時間が経過するまで前記判定手段の判定を実行しないことがより好ましい。
【００１５】
このようにすれば、最低温度を示す蒸発器用弁が第１所定時間、確実に閉状態を維持されるので補正冷却が確実に実行される。また、判定が第２所定時間行われないので、判定が頻繁に行われることによる蒸発器用弁のチャタリングを防止できる。
【００１６】
さらに、上記構成において複数の蒸発器は３基であり、第２補正量は第１補正量の半分であることがより好ましい。
【００１７】
このようにすれば、最低温度と最高温度の差の絶対値があまり大きくないときは３基の蒸発器に冷媒が多量に流れるので各収納庫を急速に冷却でき、また、絶対値差が大きいときは１基の蒸発器の運転を停止して残りの２基の蒸発器に流れる冷媒量を３基のときの半分としたので冷媒が流れ込み過ぎることもなく急速に冷却できる。従って、効率的かつ均一に商品を冷却できる。
【００１８】
加えて、上記構成において複数の商品収納庫の容量が各々異なることがより好ましい。
【００１９】
このようにすれば、容量の異なる複数の商品収納庫を備えた自動販売機においても、各蒸発器が全て運転しているとき例えば電源投入直後の運転時にも効率的かつ均一に商品を冷却できる。
【００２０】
【発明の実施の形態】
以下、添付図面を参照しながら、本発明の一実施形態に係る自動販売機の冷却装置について説明する。図１乃至図３に示すように、後述する冷却装置１を内蔵した自動販売機２は、販売機本体３と販売機本体３の前面に開閉自在に取り付けたメインドア４とで構成されている。販売機本体３の内部には、前面に断熱ドア５を有する商品収納庫６が広く設けられており、商品収納庫６は２枚の断熱隔壁７，７により、３部屋６ａ〜６ｃに仕切られている。
【００２１】
この場合、左側（または右側）の部屋６ａは冷却および加温兼用として使用され、他の２つの部屋６ｂ，６ｃは冷却専用として使用される。左側の部屋６ａおよび右側の部屋６ｃには、２列かつ４連、計８基の商品コラム８が収容され、中央の部屋６ｂには、１列かつ４連、計４基の商品コラム８が収容されている。この場合、各商品コラム８は、サーペンタイン形式の商品コラム８として上側から投入された商品Ｓを下側から払い出す（販売する）ようになっている。
【００２２】
商品収納庫６の各部屋６ａ〜６ｃには、下部に位置して前下がりの商品シュート９がそれぞれ配設されている。図２に示すように、各商品シュート９の下側空間には、本発明の冷却装置１の一部を構成する冷媒配管１０と、冷媒配管１０が接続された蒸発器（エバポレータ）１１と、庫内のエアーを循環させる庫内循環ファン１２とが設けられている。蒸発器１１は、図３に示すように各部屋６ａ〜６ｃ毎にそれぞれ設けられ、その商品収容量に応じて異なる冷却能力の蒸発器１１ａ〜１１ｃで構成されている。本実施例では、蒸発器１１ａと蒸発器１１ｂの冷却能力が等しく、この２基に比べて蒸発器１１ｃが低い冷却能力のものとなっている。
【００２３】
また、商品収納庫５の下側、すなわち販売機本体２の下部には、冷却装置１の一部を構成する上記冷媒配管１０が接続された凝縮機（コンデンサ）１３、排気ファン１４、圧縮機（コンプレッサ）１５、マフラー１６などが設けられている。なお、図示しないが、冷温兼用の部屋５ａには、商品を加温するための熱源となるヒータ（熱交換部）が組み込まれている。
【００２４】
上記冷却装置１の構成について図４を参照しながら説明すると、冷却装置１は、圧縮機１５、凝縮器１３、電子膨張弁１７、ディストリビュータ１８、電磁弁（蒸発器用弁）１９ａ〜１９ｃ、蒸発器１１ａ〜１１ｃおよびアキュームレータ２０を冷媒配管１０で直列に閉回路状に接続することにより、冷凍回路を構成している。この冷媒配管１０の中には、フレオン等の冷媒が封入されており、冷凍回路内を循環している。
【００２５】
上記の冷凍回路においては、圧縮機１５で圧縮され高温高圧になった冷媒は凝縮器１３に送られ、前述した排気ファン１４で冷却される。この冷却により凝縮化され液化された冷媒は、電子膨張弁１７に送られる。電子膨張弁１７は、後述するコントローラ２２からの入力パルス数に比例して開度θが変化する比例弁であり、入力パルス数がゼロのときは全閉となるよう構成されている。
【００２６】
次に、電子膨張弁１７を通過した冷媒は、ディストリビュータ１８で３方向に分岐されて電磁弁１９ａ〜１９ｃを通過する。この電磁弁１９は、コントローラ２２からの入力に応じて全閉、全開のいずれかの状態を取り、入力がオフのときは全閉となる常閉弁として構成されている。電磁弁１９を通過した冷媒は蒸発器１１ａ〜１１ｃに到達して気化する。この蒸発器１１ａ〜１１ｃにおける冷媒気化時の蒸発潜熱により、前述した商品収納庫６の各部屋６ａ〜６ｃが冷却される。
【００２７】
一方、蒸発器１１ａ〜１１ｃには、蒸発器の内部温度ＴＥを検出する温度センサ２１ａ〜２１ｃが設けられている。この温度センサ２１は、例えばサーミスタ等からなるセンサであり、その出力はコントローラ（制御手段、判定手段、第１開度補正手段、第２開度補正手段）２２へ入力される。コントローラ２２は、図示しないＣＰＵ、ＲＡＭ、ＲＯＭ等からなるマイクロコンピュータで構成されており、後述するように温度センサ２１から入力される検出温度に応じて、電磁弁１９ａ〜１９ｃの開閉や、電子膨張弁１７の開度θをＲＯＭ内の開度決定テーブル（表１、表２）を参照して制御する。
【００２８】
さらに、蒸発器１１ａ〜１１ｃを通過した冷媒は、アキュームレータ２０で合流して圧縮機１５に送られる。この後、運転時には上述したように冷凍回路内を再度循環して商品収納庫５の冷却が実施される。
【００２９】
以上のような構成された冷却装置１の動作について、図５のフローチャートを参照しながら説明する。まず、ステップＳ１でコントローラ２２は、温度センサ２１の検出温度ＴＥのうち少なくとも１つが所定温度ＴＥ０（例えば６〜７℃）以上か否かを判定する。
【００３０】
この判定結果が「ＮＯ」のとき、すなわち蒸発器１１ａ〜１１ｃ内の温度ＴＥが全て所定温度Ｔ０未満のときは、運転を停止する（ステップＳ１０）。一方、この判定結果が「ＹＥＳ」のときは、ステップＳ２で所定温度Ｔ０以上の蒸発器１１に対応する電磁弁１９のみを開き、その他の電磁弁１９は閉じたままにして電磁弁１９の開閉状態を決定する。そして、コントローラ２２は、予めＲＯＭ（不図示）に記憶されている下記の表１に示す「電子膨張弁の開度θ」決定テーブルを参照して、決定された電磁弁１９の開閉状態に基づき、電子膨張弁１７の開度θを決定する。
【００３１】
【表１】

【００３２】
この「電子膨張弁の開度θ」決定テーブルによれば、電磁弁１９が２基以上開いているとき、電子膨張弁１７の開度θは、θ＝１６０（パルス分）の開度に決定され、電磁弁１９が１基しか開いていないときはθ＝８０（パルス分）に決定されることが判る。
【００３３】
上記「電子膨張弁の開度θ」決定テーブルにより、電子膨張弁１７の開度θを決定したら、次にステップＳ３で全電磁弁１９が開いているか否かを判定する。この判定結果が「ＮＯ」のとき、すなわち１基か２基の電磁弁１９が開いている場合は、ステップＳ８に進み、上記ステップＳ２で決定した開度θで電子膨張弁１７を開いて、冷凍回路を運転する（ステップＳ９）。
【００３４】
一方、ステップＳ３の判定結果が「ＹＥＳ」のとき、すなわち全電磁弁１９が開いているときには、ステップＳ４で、温度センサ２１が検出した温度のうちで、一番高い温度（最高温度）が所定温度ＴＥ１（例えば、１１℃）以下か否かを判定する。この判定結果が「ＹＥＳ」のとき、すなわち検出最高温度が所定温度ＴＥ１以下の場合は、ステップＳ８に進み、上記ステップＳ２で決定した開度θで電子膨張弁１７を開いて冷凍回路を運転する（ステップＳ９）。これは、蒸発器１１が十分に冷えているので、後述するステップＳ７またはステップＳ１３の電子膨張弁１７の開度補正を行う必要がないからである。
【００３５】
また、ステップＳ４の判定結果が「ＮＯ」のとき、すなわち検出した最高温度が所定温度ＴＥ１より大きい場合は、ステップＳ５で、後述するステップＳ１７の最低温度弁閉運転の終了後に、最低温度弁が開かれてから第２所定時間ｔ２（例えば１０分間）が経過したか否かを判定する。
【００３６】
ステップＳ５の判定結果が「ＮＯ」のとき、すなわち最低温度弁が開かれてから第２所定時間ｔ２を経過していないときは、次のステップ６の判定をしないで、ステップＳ８以下に進む。これは、次のステップＳ６の判定が頻繁に行われた場合には、最低温度の電磁弁１９が頻繁に開閉される、いわゆるチャタリングを起こすおそれがあり、これを防止するためである。
【００３７】
ステップＳ５の判定結果が「ＹＥＳ」のときは、ステップＳ６で温度センサ２１により検出された、蒸発器１１ａ〜１１ｃ内の温度ＴＥａ〜ＴＥｃの差の絶対値△ＴＥを、｜ＴＥａ−ＴＥｂ｜、｜ＴＥａ−ＴＥｃ｜、｜ＴＥｂ−ＴＥｃ｜の計３通り演算する。そして、これらの差の絶対値△ＴＥにおける最大値のもの、すなわち最高温度と最低温度の差の絶対値△ＴＥが所定値△ＴＥＰ以上か否かを判定する。この判定結果が「ＮＯ」のとき、すなわち演算された温度ＴＥａ〜ＴＥｃの差の絶対値△ＴＥが、全て所定値△ＴＥＰ未満（△ＴＥ＜△ＴＥＰ）のときは、ステップＳ７で蒸発器内の温度ＴＥａ〜ＴＥｃのうちで最高温度のものに基づき、下記の表２に示す「第１補正開度θ１、第２補正開度θ２」決定テーブルを参照して、第１補正開度（第１補正量）θ１を決定して、これを先にステップＳ２で決定した開度θに加算して最終的な電子膨張弁１７の開度θｆとする。
【００３８】
【表２】

【００３９】
例えば、現在の蒸発器内温度ＴＥの最高温度が１６℃の場合、最終的な電子膨張弁１７の開度θｆは、θｆ＝θ＋θ１＝１６０＋１２０＝２８０（パルス分）となる。この電子膨張弁１７の開度θｆで運転する（ステップＳ８，Ｓ９）ことにより、蒸発器内の温度ＴＥの差の絶対値△ＴＥが全て所定値△ＴＥＰ未満のときは、大きい電子膨張弁１７の開度θｆで運転されるので、蒸発器１１ａ〜１１ｃが急速に冷却される。
【００４０】
一方、ステップＳ６の判定結果が「ＹＥＳ」のとき、すなわち演算された温度ＴＥａ〜ＴＥｃの差の絶対値△ＴＥにおける最大値のもの、すなわち最高温度と最低温度の差の絶対値△ＴＥが、所定値△ＴＥＰ以上（△ＴＥ≧△ＴＥＰ）のときは、ステップＳ１１〜ステップＳ１７の最低温度弁閉運転を実施する。
【００４１】
まず、ステップＳ１１で検出温度ＴＥから最低温度の蒸発器１１を決定して、対応する電磁弁（以下、最低温度弁という）１９を閉じる。次に、検出温度ＴＥから最高温度を決定する（ステップＳ１２）。これに基づき、上記表２の「第１補正開度θ１、第２補正開度θ２」決定テーブルを参照して、第２補正開度（第２補正量）θ２を決定する。そして、先にステップＳ２で決定した開度θに、この第２補正開度θ２を加算して最終的な電子膨張弁１７の開度θｆとする（ステップＳ１３）。
【００４２】
例えば、現在の蒸発器内温度ＴＥの最高温度が１６℃の場合、最終的な電子膨張弁１７の開度θｆは、θｆ＝θ＋θ２＝１６０＋６０＝（２２０パルス分）となる。これは、前述したステップＳ７の第１補正開度θ１を加算したものよりも小さい。しかも、開いている電磁弁１９が２基であるので、蒸発器１１に流れる冷媒量は、第１補正開度θ１を加算した開度θｆのときの１．５倍となり、商品収納庫６が速く冷却される。
【００４３】
この電子膨張弁１７の開度θｆで、最低温度弁を閉じたまま、第１所定時間ｔ１（例えば５分間）が経過するまで冷却装置を運転する（ステップＳ１５、Ｓ１６）。第１所定時間ｔ１経過後は最低温度弁を開き（ステップＳ１７）、ステップＳ１以降の運転に戻る。ただし、前述したように第２所定時間ｔ２が経過するまでは、ステップＳ６の判定を行わないので、この最低温度弁閉運転には入らない。
【００４４】
以上詳述したように、本実施例の自動販売機の冷却装置においては、検出された蒸発器内温度ＴＥａ〜ＴＥｃにおける最高温度と最低温度の差の絶対値が所定値未満（△ＴＥ＜△ＴＥＰ）のときは、大きい第１補正開度θ１を加算した最終開度θｆで冷却運転するようにしたので、均一かつ急速に各蒸発器が冷却される。また、絶対値が所定値以上（△ＴＥ≧△ＴＥＰ）ときは、最低温度弁を閉じて、第１補正開度θ１より小さい第２補正開度θ２を加算した最終開度θｆで冷却運転するようにしたので、残りの２基の蒸発器に過剰に冷媒が流れることがなく、効率的かつ均一に各蒸発器が冷却される。
【００４５】
なお、上記実施例においては、商品収納庫６の３部屋６ａ〜６ｃにそれぞれ、商品コラム８が２列−１列−２列と配置されていたが、これに限らず図６、図７に示すように、商品収納庫６の３部屋６ａ〜６ｃに商品コラム８が３列−１列−２列と配置されたものにも適用可能である。この場合、両図に示すように蒸発器１１ａ〜１１ｃは、３部屋６ａ〜６ｃ内の商品コラム８の数に応じて、異なる冷却能力（例えばその冷却能力比が、１１ａ：１１ｂ：１１ｃ＝３：１：２）を備えていることがより好ましい。また、商品収納庫の数も３基に限らず、もっと数の多いものでも良いし、各商品収納庫の容量が同一の自動販売機にも適用可能である。
【００４６】
なお、上記実施例においては、温度センサ２１が蒸発器１１内の温度を検出する構成としたが、温度センサ２１を商品収納庫６内に設け、商品収納庫６内の温度を検出して、この検出温度に基づきコントローラ２２が上記制御を行うようにしても良い。
【００４７】
【発明の効果】
以上詳述したように、本発明の自動販売機の冷却装置においては、検出された最低温度と最高温度の差の絶対値が所定値未満と判定されたときは、第１補正量を加算した電子膨張弁の開度で蒸発器に冷媒を送るようにしたので、均一かつ急速に各商品収納庫が冷却される。また、絶対値が所定値以上と判定されたときは、最低温度弁を閉じて、第１補正量より小さい第２補正量を加算した電子膨張弁の開度で蒸発器に冷媒を送るようにしたので、残りの蒸発器に過剰に冷媒が流れることがなく、効率的かつ均一に各商品収納庫が冷却される。
【図面の簡単な説明】
【図１】本発明の第１実施例に係る自動販売機の冷却装置を搭載した自動販売機の開扉状態の正面図である。
【図２】第１実施例に係る冷却装置を搭載した自動販売機の縦断面図である。
【図３】第１実施例に係る冷却装置を搭載した自動販売機の横断面図である。
【図４】第１実施例に係る冷却装置の構成を示すブロック図である。
【図５】第１実施例に係る冷却装置の動作を示すフローチャートである。
【図６】第２実施例に係る冷却装置を搭載した自動販売機の縦断面図である。
【図７】第２実施例に係る冷却装置を搭載した自動販売機の横断面図である。
【図８】従来の自動販売機の冷却装置の構成を示すブロック図である。
【符号の説明】
１冷却装置
２自動販売機
６商品収納庫
１１蒸発器
１７電子膨張弁
１９蒸発器用弁（電磁弁）
２１温度センサ
２２制御手段、判定手段、第１開度補正手段、第２開度補正手段
（コントローラ）
θ 電子膨張弁の開度
θ１第１補正量（第１補正開度）
θ２第２補正量（第２補正開度）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling device for a vending machine that sells products such as canned beverages.
[0002]
[Prior art]
Conventionally, Japanese Patent Application No. 7-4156 (hereinafter, referred to as prior application 1) by the present applicant has been proposed as a cooling device for a vending machine that sells products such as canned beverages. In the prior application 1, a compressor 101, a condenser 102, an electronic expansion valve 103, a distributor 104, electromagnetic valves 105a to 105c, evaporators 106a to 106c, an accumulator 107, and the like as shown in FIG. The cooling device 100 which comprises a refrigerating circuit connected in the shape is shown.
[0003]
Each of the evaporators 106a to 106c is provided in three product storage units (not shown) partitioned by a heat insulating partition, and the two product storage units provided with the

evaporators

106a and 106b are allocated exclusively for cooling. One commodity storage provided with the evaporator 106c is assigned for both cooling and heating. The evaporators 106a to 106c are provided with temperature sensors 109a to 109c for detecting the temperatures TEa to TEc in the evaporators 106a to 106c, and output signals from the temperature sensors 109a to 109c are input to the controller 110. Is done. The electromagnetic valves 105 a to 105 c and the electronic expansion valve 103 are controlled to open and close by a control signal from the controller 110. A refrigerant such as Freon is sealed in the refrigerant pipe 108 and circulates in the refrigeration circuit.
[0004]
In this cooling device 100, when the operation of the evaporator 106c that has been used for heating and is not used is reunited, a large amount of refrigerant flows toward the

other evaporators

106a and 106b, and the cooling of the evaporator 106c does not proceed. Will occur. In order to eliminate this, the controller 110 detects the temperatures TEa to TEc in the respective evaporators 106a to 106c by the temperature sensors 109a to 109c, and the temperature difference ΔTij between the evaporators is determined from the predetermined value ΔTo. It is determined whether or not it is larger. When this determination is YES, the controller 110 determines the evaporator 106 that is cooled most (lowest temperature), and sets the corresponding electromagnetic valve 105 in order to stop supplying the refrigerant to the evaporator 106. Close for hours. Then, after a predetermined time has elapsed, the temperature difference ΔTij between the evaporators is checked, and normal control or control for stopping the supply of the refrigerant to the evaporator 106 having the lowest temperature is performed.
[0005]
As another cooling device for a vending machine, Japanese Patent Application No. 7-22199 (hereinafter referred to as the prior application 2) by the present applicant has been proposed. In the prior application 2, in the configuration of FIG. 8 , the temperature sensor is provided not in the evaporator but in the three commodity storages provided with the evaporator, and the temperature TR in the commodity storage is detected.
[0006]
During the cooling operation, the controller 110 first checks the number of open solenoid valves 105, and when two or more solenoid valves 105 are open, opens the opening of the electronic expansion valve 103 by 160 pulses. When the number of solenoid valves 105 is one or less, the opening degree of the electronic expansion valve 103 is controlled to the number of 80 pulses. When all the solenoid valves 105 are open, the temperature TR in the product storage is checked to detect the highest internal temperature (maximum internal temperature) and refer to the ROM table, and according to this value. Control for further correcting the opening degree of the electronic expansion valve 103 is performed.
[0007]
Further, as another cooling device for a vending machine, Japanese Patent Application No. 7-22201 (hereinafter referred to as prior application 3) by the present applicant has been proposed. In this prior application 3, the piping resistance and pressure loss are changed by changing the piping configuration of the refrigerant piping 108a to 108d on the compressor 101 suction side in FIG. 8 , or the capacity of each evaporator 106 itself is changed to change each evaporator. A difference is caused in the cooling capacity of 106. Thereby, in a vending machine provided with a plurality of commodity storages with different capacities, a uniform cooling effect is obtained when all the evaporators 106 are operating.
[0008]
[Problems to be solved by the invention]
However, in the technique of the prior application 3, it is possible to uniformly cool a plurality of product storage boxes having different capacities, in other words, different cooling loads, by changing the pipe resistance or pressure loss of the pipe system or changing the capacity of the evaporator itself. However, there is a limit to the change of the piping system used in the vending machine, and there is a low degree of freedom in changing the diameter of the pipe. That is, the pipe cannot be made too thick, and conversely, if it becomes too thin, pressure loss and clogging of the refrigerant occur. Similarly, the method of changing the capacity of the evaporator itself has its cost and size limitations. For this reason, there is a demand for a vending machine that can uniformly cool a plurality of product storage boxes having different cooling loads by a method other than the size change.
[0009]
In order to solve this problem, when the technology of the prior application 1 is applied to a vending machine provided with a plurality of product storage units having different cooling loads, the technology of the prior application 1 uses a plurality of product storage units having different capacities. For example, when the supply of refrigerant to the evaporator having the lowest temperature is stopped after rapid cooling when the power is turned on, the refrigerant may flow excessively into the other evaporators in operation. For this reason, in the evaporator in which the refrigerant has flowed in excessively, since the refrigerant is not vaporized well, the evaporation temperature of the evaporator becomes high, and as a result, there is a problem that the cooling of the commodity storage is not promoted.
[0010]
In order to solve this, when the refrigerant supply to the evaporator having the lowest temperature is stopped by combining the technique of the previous application 1 with the technique of the previous application 1, the refrigerant does not flow too much into the other evaporators in operation. It is possible to do. However, since the prior application 2 determines the opening degree of the electronic expansion valve according to the number of open electromagnetic valves, and then corrects the electronic expansion valve to be opened further when all the electromagnetic valves are opened, When rapid cooling is desired as when the power is turned on, there is a problem that the correction amount of the electronic expansion valve is not appropriate and the cooling rate becomes slow.
[0011]
The present invention has been made in order to solve the above-described problem. Even in a vending machine including a plurality of product storage units having different capacities, when all the evaporators are in operation, for example, during operation immediately after turning on the power, It is an object of the present invention to provide a cooling device for a vending machine capable of obtaining a cooling effect efficiently and uniformly without increasing the evaporation temperature of the container or slowing down the cooling rate.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, an evaporator constituting a part of the refrigeration circuit is disposed in each of the plurality of commodity storages, and the refrigerant is sent to the evaporator to evaporate the refrigerant in the evaporator. In the vending machine cooling device configured to cool the evaporator independently, the opening degree of the evaporator valve provided on the inlet side refrigerant pipe of each evaporator can be adjusted and the opening degree can be adjusted upstream of the evaporator valve. An electronic expansion valve installed in the product, a temperature sensor for detecting the temperature of each product storage and the corresponding evaporator, and opening / closing of each evaporator valve based on the detected temperature of each temperature sensor And a control means for determining the opening degree of the electronic expansion valve in accordance with the opening / closing of each determined evaporator valve, and the control means has a minimum at the detected temperature when all the evaporator valves are open. The absolute value of the difference between the temperature and the maximum temperature is the predetermined value. And a first opening that corrects by adding a first correction amount to the opening degree of the electronic expansion valve previously determined based on the maximum temperature when the determination result is less than the predetermined value. When the degree correction means and the determination result are equal to or greater than a predetermined value, the evaporator valve corresponding to the lowest temperature is closed, and the opening of the electronic expansion valve previously determined based on the highest temperature is smaller than the first correction amount. And a second opening degree correcting means for correcting by adding two correction amounts.
[0013]
As described above, when all the evaporator valves are open, it is determined whether or not the absolute value of the difference between the lowest temperature and the highest temperature is greater than or equal to a predetermined value. Since the first correction amount is added to the previously determined opening of the electronic expansion valve based on the maximum temperature for correction, only the specific product storage is not cooled, and all the product storage is uniformly and rapidly performed. Can be cooled. Further, if the determination result is equal to or greater than a predetermined value, the evaporator correction valve corresponding to the lowest temperature is closed, and based on the highest temperature, the opening degree of the electronic expansion valve determined previously is a second correction amount smaller than the first correction amount. As a result, the amount of refrigerant does not flow too much in the remaining evaporators, and the entire product storage can be cooled uniformly and rapidly. Therefore, according to this vending machine, when all the evaporators are in operation, for example, the product can be efficiently and uniformly cooled even during operation immediately after the power is turned on.
[0014]
In the above configuration, the control means maintains the lowest temperature evaporator valve closed for a first predetermined time when the determination result is equal to or greater than a predetermined value, and sets the evaporator valve at the lowest temperature portion after the first predetermined time has elapsed. More preferably, the determination means does not execute the determination until the second predetermined time has elapsed.
[0015]
In this way, the evaporator valve showing the minimum temperature is reliably kept closed for the first predetermined time, so that the corrective cooling is reliably performed. Moreover, since the determination is not performed for the second predetermined time, chattering of the evaporator valve due to frequent determination can be prevented.
[0016]
Further, in the above configuration, the number of the plurality of evaporators is three, and the second correction amount is more preferably half of the first correction amount.
[0017]
In this way, when the absolute value of the difference between the lowest temperature and the highest temperature is not so large, a large amount of refrigerant flows through the three evaporators, so that each storage can be rapidly cooled, and the absolute value difference is large. In some cases, the operation of one evaporator is stopped and the amount of refrigerant flowing to the remaining two evaporators is halved compared to the case of three, so that the refrigerant can be rapidly cooled without flowing too much. Therefore, the product can be efficiently and uniformly cooled.
[0018]
In addition, in the above configuration, it is more preferable that the capacities of the plurality of commodity storages are different.
[0019]
In this way, even in a vending machine having a plurality of product storage units with different capacities, the product can be efficiently and uniformly cooled when all the evaporators are operating, for example, immediately after the power is turned on. .
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a cooling device for a vending machine according to an embodiment of the present invention will be described with reference to the accompanying drawings. As shown in FIGS. 1 to 3, a vending machine 2 including a cooling device 1 to be described later includes a vending machine main body 3 and a main door 4 attached to the front surface of the vending machine main body 3 so as to be freely opened and closed. . Inside the vending machine body 3, a product storage 6 having a heat insulating door 5 on the front is widely provided. The product storage 6 is divided into three rooms 6a to 6c by two heat insulating

partition walls

7 and 7. ing.
[0021]
In this case, the left (or right) room 6a is used for both cooling and heating, and the other two

rooms

6b and 6c are used only for cooling. In the left room 6a and the right room 6c, two rows and four columns, a total of eight product columns 8 are accommodated, and in the central room 6b, one column and four columns, a total of four product columns 8 are stored. Contained. In this case, each product column 8 pays out (sells) from the lower side the product S introduced from the upper side as the product column 8 in the serpentine format.
[0022]
In each of the rooms 6a to 6c of the product storage case 6, a product chute 9 which is located at the lower part and is lowered downward is arranged. As shown in FIG. 2, in the lower space of each product chute 9, a refrigerant pipe 10 constituting a part of the cooling device 1 of the present invention, an evaporator (evaporator) 11 to which the refrigerant pipe 10 is connected, An internal circulation fan 12 that circulates the air in the internal space is provided. As shown in FIG. 3, the evaporator 11 is provided for each of the rooms 6 a to 6 c, and is composed of evaporators 11 a to 11 c having different cooling capacities depending on the product capacity. In this embodiment, the evaporator 11a and the evaporator 11b have the same cooling capacity, and the evaporator 11c has a lower cooling capacity than the two units.
[0023]
Further, a condenser (condenser) 13, an exhaust fan 14, and a compressor to which the refrigerant pipe 10 constituting a part of the cooling device 1 is connected below the commodity storage 5, that is, at the lower part of the vending machine main body 2. A (compressor) 15 and a muffler 16 are provided. In addition, although not shown in figure, the heater (heat exchanging part) used as the heat source for heating goods is incorporated in the room 5a for cold / hot use.
[0024]
The configuration of the cooling device 1 will be described with reference to FIG. 4. The cooling device 1 includes a compressor 15, a condenser 13, an electronic expansion valve 17, a distributor 18, electromagnetic valves (evaporator valves) 19a to 19c, and an evaporator. By connecting 11a to 11c and the accumulator 20 in series in a closed circuit configuration with the refrigerant pipe 10, a refrigeration circuit is configured. A refrigerant such as Freon is enclosed in the refrigerant pipe 10 and circulates in the refrigeration circuit.
[0025]
In the above-described refrigeration circuit, the refrigerant that has been compressed by the compressor 15 to become high temperature and pressure is sent to the condenser 13 and cooled by the exhaust fan 14 described above. The refrigerant condensed and liquefied by this cooling is sent to the electronic expansion valve 17. The electronic expansion valve 17 is a proportional valve in which the opening degree θ changes in proportion to the number of input pulses from the controller 22, which will be described later, and is configured to be fully closed when the number of input pulses is zero.
[0026]
Next, the refrigerant that has passed through the electronic expansion valve 17 is branched in three directions by the distributor 18 and passes through the electromagnetic valves 19a to 19c. The electromagnetic valve 19 is configured as a normally closed valve that takes either a fully closed state or a fully opened state in response to an input from the controller 22 and is fully closed when the input is off. The refrigerant that has passed through the electromagnetic valve 19 reaches the evaporators 11a to 11c and is vaporized. The rooms 6a to 6c of the commodity storage 6 described above are cooled by the latent heat of vaporization when the refrigerant is vaporized in the evaporators 11a to 11c.
[0027]
On the other hand, the evaporators 11a to 11c are provided with temperature sensors 21a to 21c for detecting the internal temperature TE of the evaporator. The temperature sensor 21 is a sensor made of, for example, a thermistor, and its output is input to a controller (control means, determination means, first opening correction means, second opening correction means) 22. The controller 22 is composed of a microcomputer including a CPU, RAM, ROM, etc. (not shown), and opens and closes the electromagnetic valves 19a to 19c and electronically expands according to a detected temperature input from the temperature sensor 21 as will be described later. The opening degree θ of the valve 17 is controlled with reference to the opening degree determination tables (Tables 1 and 2) in the ROM.
[0028]
Further, the refrigerant that has passed through the evaporators 11 a to 11 c merges in the accumulator 20 and is sent to the compressor 15. Thereafter, during operation, the product storage 5 is cooled by circulating again in the refrigeration circuit as described above.
[0029]
The operation of the cooling device 1 configured as described above will be described with reference to the flowchart of FIG. First, in step S1, the controller 22 determines whether or not at least one of the detected temperatures TE of the temperature sensor 21 is equal to or higher than a predetermined temperature TE0 (for example, 6 to 7 ° C.).
[0030]
When the determination result is “NO”, that is, when all the temperatures TE in the evaporators 11a to 11c are lower than the predetermined temperature T0, the operation is stopped (step S10). On the other hand, when the determination result is “YES”, only the solenoid valve 19 corresponding to the evaporator 11 having the predetermined temperature T0 or higher is opened in step S2, and the other solenoid valves 19 are kept closed to open / close the solenoid valve 19. Determine the state. Then, the controller 22 refers to an “opening degree θ of the electronic expansion valve” determination table shown in the following Table 1 stored in advance in a ROM (not shown), and based on the determined open / close state of the electromagnetic valve 19. The opening degree θ of the electronic expansion valve 17 is determined.
[0031]
[Table 1]

[0032]
According to this “opening degree θ of the electronic expansion valve” determination table, when two or more solenoid valves 19 are opened, the opening degree θ of the electronic expansion valve 17 is determined to be an opening degree of θ = 160 (pulses). It can be seen that when only one solenoid valve 19 is open, θ is determined to be 80 (pulses).
[0033]
If the opening degree θ of the electronic expansion valve 17 is determined by the above-described “opening degree θ of electronic expansion valve” determination table, it is next determined in step S3 whether all the solenoid valves 19 are open. When the determination result is “NO”, that is, when one or two solenoid valves 19 are open, the process proceeds to step S8, the electronic expansion valve 17 is opened at the opening θ determined in step S2, and The refrigeration circuit is operated (step S9).
[0034]
On the other hand, when the determination result in step S3 is “YES”, that is, when all the solenoid valves 19 are open, the highest temperature (maximum temperature) among the temperatures detected by the temperature sensor 21 in step S4 is predetermined. It is determined whether or not the temperature is TE1 (for example, 11 ° C.) or lower. When the determination result is “YES”, that is, when the detected maximum temperature is equal to or lower than the predetermined temperature TE1 , the process proceeds to step S8, and the refrigeration circuit is operated by opening the electronic expansion valve 17 at the opening degree θ determined in step S2. (Step S9). This is because the evaporator 11 is sufficiently cooled, and it is not necessary to correct the opening of the electronic expansion valve 17 in step S7 or step S13 described later.
[0035]
On the other hand, when the determination result in step S4 is “NO”, that is, when the detected maximum temperature is higher than the predetermined temperature TE1, in step S5, after completion of the minimum temperature valve closing operation in step S17 described later, the minimum temperature valve is It is determined whether or not a second predetermined time t2 (for example, 10 minutes) has elapsed since the opening.
[0036]
If the determination result in step S5 is “NO” , that is, if the second predetermined time t2 has not elapsed since the lowest temperature valve was opened, the process proceeds to step S8 and subsequent steps without determining in next step 6. This is to prevent the so-called chattering that the electromagnetic valve 19 having the lowest temperature is frequently opened and closed when the determination in the next step S6 is frequently performed.
[0037]
When the determination result in step S5 is “YES” , the absolute value ΔTE of the difference between the temperatures TEa to TEc in the evaporators 11a to 11c detected by the temperature sensor 21 in step S6 is expressed as | TEa−TEb | | TEa−TEc | and | TEb−TEc | Then, it is determined whether the absolute value ΔTE of the difference between these absolute values ΔTE, that is, the absolute value ΔTE of the difference between the highest temperature and the lowest temperature is equal to or greater than a predetermined value ΔTEP. When the determination result is “NO”, that is, when the absolute value ΔTE of the difference between the calculated temperatures TEa to TEc is less than the predetermined value ΔTEP (ΔTE <ΔTEP), in step S7 Based on the highest temperature among the temperatures TEa to TEc, with reference to the “first correction opening θ1, second correction opening θ2” determination table shown in Table 2 below, the first correction opening (first 1 correction amount) [theta] 1 is determined and added to the opening [theta] previously determined in step S2 to obtain the final opening [theta] f of the electronic expansion valve 17.
[0038]
[Table 2]

[0039]
For example, when the current maximum temperature in the evaporator TE is 16 ° C., the final opening degree θf of the electronic expansion valve 17 is θf = θ + θ1 = 160 + 120 = 280 (for pulses). By operating at the opening degree θf of the electronic expansion valve 17 (steps S8 and S9), when the absolute values ΔTE of the differences in temperature TE in the evaporator are all less than the predetermined value ΔTEP, the large electronic expansion valve 17 Therefore, the evaporators 11a to 11c are rapidly cooled.
[0040]
On the other hand, when the determination result of step S6 is “YES”, that is, the absolute value ΔTE of the difference between the calculated temperatures TEa to TEc, that is, the absolute value ΔTE of the difference between the maximum temperature and the minimum temperature is When the value is equal to or greater than a predetermined value ΔTEP (ΔTE ≧ ΔTEP), the minimum temperature valve closing operation in steps S11 to S17 is performed.
[0041]
First, in step S11, the evaporator 11 having the lowest temperature is determined from the detected temperature TE, and the corresponding electromagnetic valve (hereinafter referred to as the lowest temperature valve) 19 is closed. Next, the maximum temperature is determined from the detected temperature TE (step S12). Based on this, the second correction opening (second correction amount) θ2 is determined with reference to the “first correction opening θ1, second correction opening θ2” determination table in Table 2 above. Then, the second corrected opening θ2 is added to the opening θ previously determined in step S2 to obtain the final opening θf of the electronic expansion valve 17 (step S13).
[0042]
For example, when the current maximum temperature TE of the evaporator TE is 16 ° C., the final opening degree θf of the electronic expansion valve 17 is θf = θ + θ2 = 160 + 60 = (220 pulses). This is smaller than the sum of the first correction opening θ1 in step S7 described above. Moreover, since there are two open solenoid valves 19, the amount of refrigerant flowing through the evaporator 11 is 1.5 times the opening θf obtained by adding the first correction opening θ1, and the commodity storage 6 Cools quickly.
[0043]
With the opening degree θf of the electronic expansion valve 17, the cooling device is operated until a first predetermined time t1 (for example, 5 minutes) elapses with the minimum temperature valve closed (steps S15 and S16). After the first predetermined time t1 has elapsed, the minimum temperature valve is opened (step S17), and the operation returns to the operation after step S1. However, since the determination in step S6 is not performed until the second predetermined time t2 elapses as described above, the minimum temperature valve closing operation is not entered.
[0044]
As described above in detail, in the cooling device for the vending machine of the present embodiment, the absolute value of the difference between the highest temperature and the lowest temperature in the detected evaporator temperatures TEa to TEc is less than a predetermined value (ΔTE <Δ In the case of TEP), since the cooling operation is performed at the final opening θf obtained by adding the large first correction opening θ1, each evaporator is cooled uniformly and rapidly. When the absolute value is equal to or greater than a predetermined value (ΔTE ≧ ΔTEP), the lowest temperature valve is closed and the cooling operation is performed at the final opening θf obtained by adding the second correction opening θ2 smaller than the first correction opening θ1. As a result, the refrigerant does not flow excessively to the remaining two evaporators, and each evaporator is cooled efficiently and uniformly.
[0045]
In the above-described embodiment, the product columns 8 are arranged in 2 rows, 1 row, and 2 rows in the three rooms 6a to 6c of the product storage 6, respectively, but not limited to this, FIGS. As shown, the present invention can also be applied to a case in which the product columns 8 are arranged in 3 rows, 1 row, and 2 rows in the three rooms 6 a to 6 c of the product storage 6. In this case, as shown in both figures, the evaporators 11a to 11c have different cooling capacities (for example, the cooling capacity ratio is 11a: 11b: 11c = 3) according to the number of the product columns 8 in the three rooms 6a to 6c. 1: 2) is more preferable. Further, the number of merchandise storage boxes is not limited to three, but may be a larger number, and can be applied to vending machines having the same capacity for each merchandise storage box.
[0046]
In the above embodiment, the temperature sensor 21 detects the temperature in the evaporator 11, but the temperature sensor 21 is provided in the product storage 6 to detect the temperature in the product storage 6, The controller 22 may perform the above control based on the detected temperature.
[0047]
【The invention's effect】
As described in detail above, in the vending machine cooling device of the present invention, when the absolute value of the difference between the detected minimum temperature and the maximum temperature is determined to be less than the predetermined value, the first correction amount is added. Since the refrigerant is sent to the evaporator at the opening degree of the electronic expansion valve, each commodity storage is cooled uniformly and rapidly. When it is determined that the absolute value is equal to or greater than the predetermined value, the minimum temperature valve is closed, and the refrigerant is sent to the evaporator at the opening of the electronic expansion valve obtained by adding a second correction amount smaller than the first correction amount. As a result, the refrigerant does not flow excessively to the remaining evaporators, and each commodity storage is cooled efficiently and uniformly.
[Brief description of the drawings]
FIG. 1 is a front view of a vending machine equipped with a vending machine cooling device according to a first embodiment of the present invention when the door is open.
FIG. 2 is a longitudinal sectional view of a vending machine equipped with a cooling device according to the first embodiment.
FIG. 3 is a cross-sectional view of a vending machine equipped with the cooling device according to the first embodiment.
FIG. 4 is a block diagram showing the configuration of the cooling device according to the first embodiment.
FIG. 5 is a flowchart showing the operation of the cooling device according to the first embodiment.
FIG. 6 is a longitudinal sectional view of a vending machine equipped with a cooling device according to a second embodiment.
FIG. 7 is a cross-sectional view of a vending machine equipped with a cooling device according to a second embodiment.
FIG. 8 is a block diagram showing a configuration of a cooling device of a conventional vending machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cooling device 2 Vending machine 6 Goods storage 11 Evaporator 17 Electronic expansion valve 19 Evaporator valve (solenoid valve)
21 Temperature sensor 22 Control means, determination means, first opening correction means, second opening correction means (controller)
θ Electronic expansion valve opening θ1 First correction amount (first correction opening)
θ2 Second correction amount (second correction opening)

Claims

An evaporator constituting a part of a refrigeration circuit is disposed in each of the plurality of product storages, and the plurality of product storages are made independent by sending a refrigerant to the evaporator and evaporating the refrigerant in the evaporator. In a vending machine cooling device configured to cool
An evaporator valve provided on the inlet side refrigerant pipe of each of the evaporators so as to be openable and closable;
An electronic expansion valve provided on the upstream side of the evaporator valve so that the opening degree can be adjusted;
A temperature sensor for detecting the temperature of at least one of the inside of each commodity storage and the corresponding evaporator.
Control means for determining the opening and closing of each evaporator valve based on the temperature detected by each temperature sensor, and determining the opening of the electronic expansion valve according to the determined opening and closing of each evaporator valve;
The control means, when all the evaporator valves are open, determination means for determining whether or not the absolute value of the difference between the lowest temperature and the highest temperature at the detected temperature is a predetermined value or more,
When the determination result is less than the predetermined value, first opening correction means for correcting the opening of the electronic expansion valve previously determined based on the maximum temperature by adding a first correction amount;
If the determination result is equal to or greater than the predetermined value, the evaporator valve corresponding to the minimum temperature is closed, and the opening of the electronic expansion valve previously determined based on the maximum temperature is greater than the first correction amount. A vending machine cooling device, comprising: a second opening correction means for correcting by adding a small second correction amount.

The control means maintains the closed state of the evaporator valve at the lowest temperature portion for a first predetermined time when the determination result is equal to or greater than the predetermined value, and after the first predetermined time has elapsed, 2. The cooling device for a vending machine according to claim 1, wherein the evaporator valve is opened and the determination by the determination means is not executed until a second predetermined time has elapsed.

3. The cooling device for a vending machine according to claim 1, wherein the plurality of evaporators are three, and the second correction amount is half of the first correction amount.

4. The cooling device for a vending machine according to claim 1, wherein capacities of the plurality of commodity storages are different from each other.