JP3852537B2

JP3852537B2 - Heat insulation box

Info

Publication number: JP3852537B2
Application number: JP10761199A
Authority: JP
Inventors: 芳夫西本; 威則足達
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1999-04-15
Filing date: 1999-04-15
Publication date: 2006-11-29
Anticipated expiration: 2019-04-15
Also published as: JP2000304428A

Description

【０００１】
【発明の属する技術分野】
本発明は冷蔵庫などに使用される断熱箱体に関するものであり、さらに詳しくは断熱箱体を構成する壁内に備える真空断熱部材の配設に関するものである。
【０００２】
【従来の技術】
従来、冷蔵庫などに用いる断熱箱体の壁面は、外郭を鉄板などの金属製薄板で覆い内面部分を樹脂成形品で形成して、その間隙に発泡ウレタンを注入発泡して充填させたものが用いられてきた。断熱材である発泡ウレタンの発泡剤には、ハイドロクロロフルオロカーボン類である１,１−ジクロロ−１−フルオロエタン(HCFC141b)が用いられてきたが、近年、オゾン層破壊の原因となる塩素を分子中に含まないハイドロフルオロカーボン類やハイドロカーボン類を用いている。
【０００３】
例えば、特開平２−２３５９８２号公報では１,１,１,３,３−ペンタフルオロプロパン(HFC245fa)や１,１,１,４,４,４−ヘキサフルオロブタン(HFC356mffm)のようなハイドロフルオロカーボン類を、特開平３−１５２１６０号公報ではシクロペンタンなどのハイドロカーボンを、発泡剤に適用した発泡ウレタンの製造方法が開示されている。しかしながら、これら発泡ウレタンの断熱性は１９〜２０mw/MKであり、オゾン層破壊物質の仕様規制前に用いていたクロロフルオロカーボン類を用いた場合の１６mw/MKの断熱性に比較すれば明らかに劣る。
【０００４】
このため、従来の多孔体である発泡ウレタンの２倍以上の断熱性能である５〜８mw/mKが得られる真空断熱部材を応用する技術が提案されている。真空断熱部材が有する伝熱の構成要素としては、多孔体が有する伝熱の構成要素のうち、気孔内のガスを排除したことによって、ガスを伝わる熱が削除されたことによって優れた断熱性能が発現されるものである。
【０００５】
つまり、多くの気孔を備える多孔質物質は樹脂などを発泡させることによって形成されたり、多くの粒子間に空隙を形成して構成されたりする。このため、多孔体物質の熱伝達を模式的に示すと、下記の式（１）に示すような４成分の総和として表現できる。つまり、多孔体を構成する固体部分を伝わる固体伝熱成分（λｓ）、同様にガス成分を伝わるガス伝熱成分（λｇ）、電磁波である熱線放射による輻射伝熱成分（λｒ）と、気孔内のガスの対流運動によって伝わる対流成分（λｃ）である。このうち、対流成分（λｃ）は、多孔質物質が、大気圧を受けても経時的に変形を来さない強度を得るために発泡樹脂の樹脂の量比を高くしたり、粒子を密に充填するなどの措置を施した結果、気孔の中にあるガスが対流運動を来さないような大きさの気孔が一般に用いられて成るのでλｃを無視しても良く、その結果、残りの３成分（λｓ、λｇ、λｒ）によって実質的に構成される。
【０００６】
λ＝λｓ＋λｇ＋λｒ＋λｃ（１）
【０００７】
ところが、真空断熱部材では、その内部にある多孔体の気孔内にあったガスを無くして真空状態としたので、上述の如く、発泡樹脂と同様の連続した気孔を含む多孔体の伝熱成分の一つであるガスによる熱伝達成分（λｇ）をも無くすることができたので、発泡樹脂の如き断熱材と比較して、際だって優れた断熱性能を発現することができる。
【０００８】
このような真空断熱部材１は図６に示す構造を成しており、包装材２によって外部からのガスの侵入を抑制して真空を保持された内部に、形状を維持する役割を備える芯材３として、多孔質物質が挿入されている。つまり、断熱材である発泡ウレタンなどの発泡樹脂と同様の多孔質物質であるが、気孔内のガスを無くして真空状態を確保すると共に、経時的に侵入する外部のガスを吸収するゲッター剤４を備えたことに伴って高度な真空状態を維持して成るので、ガスによる熱伝達成分が排除され、優れた断熱性能が発現するものである。ここで、更なる断熱性能の向上を達成するためには、構成する材料に熱が伝達し難い物質を用いるとともに材料間の接触面積を少なくすることによって物質内を伝達する熱量を抑制していること、更に小さな空隙を備えることによって輻射伝熱を抑制することが有効となる。
【０００９】
次に、真空断熱部材１の製造方法について、図７に示す工程図を用いて説明すると、三方向が予め熱シールされた包装材２を形成（Ｓ−１）し、この袋の内に連通気泡を有する発泡ウレタンなどで構成された芯材３を挿入する（Ｓ−２）。これを、図８に示すような真空包装機５のチャンバー内に固定し、チャンバー内を１×１０^-1〜１×１０^-3Torr程度の真空雰囲気を確保する真空引きを行った（Ｓ−３）後、挿入口６である残りの端辺を加圧機７とヒータを内蔵した加熱機８を用いて融着する（Ｓ−４）ことによって封止をする。最後に、芯材３の挿入口をシールして内層に用いている熱可塑性樹脂の融点以下にまで冷却後、真空包装機５内部の真空を解除して常圧に戻れば、真空断熱部材１を取り出す（Ｓ−５）。
【００１０】
ここで用いる真空断熱部材１の包装材２に用いるシート材は、図９に示す如くの構造を備える。つまり、端辺のシールに供する内層には熱溶着が可能なポリエチレンやポリプロピレンなどの熱可塑性樹脂から成る熱融着層９、最外層には傷つきなどに耐性のあるナイロンやポリエステルなどの樹脂からなる表面層１０、その間にある中間層には外気の侵入を完全に遮断するためのアルミなどの金属箔を用いて成るガス遮蔽層１１がポリエチレンテレフタレートなどの強度の高いフィルムである基材１２上に固定された状態を備えて構成されたものであって、シート状を成す各層を構成する材料を接着剤や溶着などによって積層、一体化することによって得られた多層シート１３は発泡剤や大気中のガスが透過し難くい。
【００１１】
しかし、包装材である多層シート内に系外からのガスの侵入を遮蔽する目的で配設されるガス遮蔽層１１には、包装材２の取り扱いや加工性を考慮して、延展性を含む柔軟性に優れたアルミニュームを蒸着や箔の配設によって薄膜状態で設ける。しかし、ガス遮蔽層１１として一般に用いるアルミ箔などの薄膜には、他の構成材である樹脂シートに比較して約１０³倍もの高熱伝導性を有することから、それが有する熱伝導率を一般の樹脂に代替すれば、数ミリから数十ミリの厚さに相当し、特に、その影響として、真空状態の断熱材によって伝熱が遮蔽される厚さ方向よりも、むしろ物質単体の伝熱によって醸し出される面方向の伝熱の影響が無視できない量におよぶ。
【００１２】
つまり、包装材２が芯材３を包み込んで配設された真空断熱部材１において、例えば図１０に示す冷蔵庫における伝熱経路の場合、外気の熱が外壁材である外箱１５から当接する真空断熱部材１の包装材２表面（受熱面）を経た後、真空断熱部材１面の中央部では厚さ方向に貫通熱が支配的あるのに対し、両端部では真空断熱部材１の端辺部分１６およびさらにそこを伝わって対向する断熱壁内部に埋設されている包装材２面を経た後、もう一つの断熱材であって多孔質断熱材である発泡ウレタン１７から内壁材である内箱１８を経て庫内に拡散する。このような伝熱経路である熱架橋の影響が支配的であり、従って、これを排除することが真空断熱部材の特性を生かした断熱構造体を得るうえで重要な要素である。
【００１３】
このような問題に対処するため、特開昭５９−１４６９９３号公報では、包装材２の内層に配するアルミ箔の厚さを２０ミクロン以下とすることによって、伝熱量を抑制することを提案している。
【００１４】
また、特開平５−３０２６９６号公報では図１１に示す如く、受熱面と放熱面を接合する部分である熱融着部１９には、熱融着層９と表面層１０の間隙にガス遮蔽層１１であるアルミ箔２０を配しない包装材２を何れかの面の多層シートに用いることによって、アルミ箔２０を配したもう一方の多層シートとの間で重なることがないようにすることにより、伝熱が円滑に行えないようにして熱架橋の影響が抑制できる構造を提案している。
【００１５】
しかしながら、上述した特開昭５９−１４６９９３号公報の方法では、アルミ箔を展延させて薄膜にする過程で発生するピンホールなどの欠陥のため、ガス遮蔽性能が低下することのないようにすることが必要であり、当該公報では下限の膜厚を７ミクロンとしている。しかし、たとえ、この下限膜厚を備えたとしても、これを熱伝導率の関係から包装材に用いる樹脂に置き換えれば１０mmにも達し、熱架橋として及ぼす影響として無視することはできない。
【００１６】
また、特開平５−３０２６９６号公報の方法では包装材製造における２枚の多層シートの接合加工に極めて高い精度を必要とし、実用性に課題を有する。つまり、２枚の多層シートを接合する際に位置ずれを来たせば、包装材の一方の面にアルミ箔が存在せずにガス透過係数の大きい樹脂の層しか存在しない部分が広く開くことになる。従って、ガスの遮蔽性能が大きく劣る当該部分からは大気中のガスが容易に侵入し、包装材内部の真空度を短期間に大きく低下させるので、断熱性能が短期に劣化するという問題を発生させる。
【００１７】
このような問題に対処するため、実開昭６３−２０８０号公報には、真空断熱部材を多孔質断熱材等を用いた複数の固定具を介して外殻面に固定し、真空断熱部材、固定具及び外壁材間に形成される空隙に発泡ウレタンを充填することによって、上述した熱架橋を来す伝熱量を抑制する手段を示している。つまり、発泡ウレタンで空隙を充填したので、真空断熱部材が外箱に直接的な接触のない断熱箱体を形成し、真空断熱部材への伝熱が円滑に来されなくなり、その結果、伝熱量を抑制できるものである。
【００１８】
【発明が解決しようとする課題】
従来の断熱箱体は以上のように構成されており、受熱面側にある外箱と真空断熱部材の間に充填する発泡ウレタンの圧力に耐えて配設した位置を保持するためには、外壁材と真空断熱部材に対する固定具の接着面積を大きくする必要があり、その結果、発泡ウレタンが流動した後方に相当する部位では、流れに乱れを生じて空気を残留させて空隙を発生させて、断熱性能が低下することがあった。また、固定具と充填した発泡ウレタンの収縮率の違いは、局部的な変形を生み、外箱表面に凹凸を形成して外観意匠性を損なうこともあった。
【００１９】
本発明は上記課題を解決するために成されたものであり、真空断熱部材への伝熱量を抑制して断熱効率に優れた断熱箱体を得るとともに、外観の変形の小さい断熱箱体を得ることを目的とする。
【００２０】
【課題を解決するための手段】
外箱の構成要素である外壁部材と、内箱の構成要素である内壁部材と、外壁部材の内壁側に配設され、連通気泡を備える発泡樹脂からなる板状部材と、内壁部材の外壁側に向き合う板状部材の面に設けられた真空断熱部材と、外壁部材と内壁部材との間を充填する断熱部材とを備える。
【００２１】
外箱の構成要素である外壁部材と、内箱の構成要素である内壁部材と、内壁部材の外壁側に配設され、連通気泡を備える発泡樹脂からなる板状部材と、外壁部材の内壁側に向き合う板状部材の面に設けられた真空断熱部材と、外壁部材と内壁部材との間を充填する断熱部材とを備える。
【００２１】
外箱の構成要素である外壁部材と、内箱の構成要素であり、外壁部材の内壁側と平行でない外壁側を有する内壁部材と、外壁部材の内壁側に配設され、内側部材に向き合う面に真空断熱部材が設けられ、真空断熱部材の内壁部材の外壁側と向き合う面が内壁部材の外壁側と平行になるように設けられる断熱材からなる板状部材と、外壁部材と内壁部材との間を充填する断熱部材とを備える。
【００２２】
また、板状部材は、連通気泡を備える発泡樹脂からなる。
【００２３】
また、断熱部材が、発泡樹脂である。
【００２４】
また、真空断熱部材の外側端部が壁部材に当接することを防止するように配設したものである。
【００２５】
【発明の実施の形態】
この発明の実施の形態を図について説明する。
図において従来のものと同一または相当のものは同じ符号を付して説明を省略する。図１は、本発明の実施の形態による断熱箱体を示す概略斜視図である。また、図２は、本発明の実施の形態による断熱箱体を含む冷蔵庫等の製品の製造工程を示す工程図である。
実施の形態１．
図３は本発明の実施の形態１による断熱箱体の断面構造を示す要部断面図である。１は真空断熱部材で、１５は薄板鋼板等の曲げ加工品などで構成された外箱（外壁部材）であり、１７は外箱１５、内箱１８、板状部材２２及び真空断熱部材１の間で構成される空間に充填された発泡ウレタン（断熱部材）で、１８はＡＢＳ樹脂シートを真空成形するなどして得た成型品である内箱（内壁部材）、また２２は連通気泡を備える発泡ウレタンを裁断した板状の加工品であって、外箱内面に固定する真空断熱部材１と外箱１５内面との間隙に配設する板状部材である。
【００２６】
ここで用いた真空断熱部材１は、例えば５００ｍｍ×６００ｍｍの板状に形成されており、外箱内面に任意の間隔を有して設けた両面テープによって、連通気泡を備える発泡ウレタンを裁断した板状の加工品である板状部材を介して固定している。
【００２７】
次に、断熱箱体の製造方法について詳述すると、まず、上述した図７に示す従来の断熱箱体の製作工程図と同様の手段、つまり、包装材を形成（Ｓ−１）し、この内に芯材を挿入した（Ｓ−２）後、真空引き（Ｓ−３）および端辺の熱シール（Ｓ−４）を行って、最後に真空断熱部材の取り出し（Ｓ−５）、の工程を経て真空断熱部材を得た。
【００２８】
上記真空引き工程では、真空包装機に芯材３を挿入した包装材２を固定して真空雰囲気を形成し、芯材３の気孔内に残存する空気などのガスを排気する。真空度は１ｔｏｒｒ以下、好ましくは５×１０^-2torrを確保する。気孔内にあるガスの排気には包装材２と芯材３の間に隙間が形成されているので、挿入口端部のみならず、芯材３の表面からも排気が出来るので、目標の真空度への到達が容易に行われる。
【００２９】
また、ここで用いる包装材２には端辺のシールに供する内層に熱融着が可能な高密度ポリエチレンを用いた多層シートを用いて３方の端辺を線状に熱融着させて袋状に成形したもの、芯材３には連通気泡を備えた発泡ウレタンを板状に裁断加工したものを各々用いた。
【００３０】
ここで用いた真空断熱部材１は、例えば５００ｍｍ×６００ｍｍの板状に形成されており、外箱１５内面に任意の間隔を有して設けた両面テープによって、連通気泡を備える発泡ウレタンを裁断した板状部材２２を介して固定している。なお、上述した真空断熱部材１の芯材３に用いる連通気泡を備える発泡樹脂と板状部材２２に用いる連通気泡を備える発泡樹脂とは、同一のものであっても、異なったものであってもよい。
【００３１】
また、芯材３である連通気泡を備えた発泡ウレタンの板状成型品について説明すると、まず、発泡ウレタンの原料液には、ポリオールを中心に触媒、整泡剤、破泡剤、発泡剤などの助剤が混合されて成るプレミックス液と、イソシアネートが主成分であるイソシアネート液の２液を混合して発泡させる。この２液の規定量をインペラー形のミキサーなどを用いて混合したものを、数秒後に開始される発泡に間に合うように、３０℃〜６０℃、好ましくは４０℃〜５０℃に保温した任意の大きさ、本実施の形態では一辺が６００mmで深さが４５mmのアルミ製の金型内に投入後、密閉した状態で硬化が完了するまで、５分以上の放置をした後にボード状の成型品を得た。この連通気泡を有する発泡ウレタン成形品のバルクから板状の芯材３と成すためには、独立した気泡が多く残存する表層部分を排除するために、任意の厚さの外周と表層部分を切断して、４５０mm×４５０mm×１５mmの裁断加工品を得た。
【００３２】
真空断熱部材１の芯材３には、ここで用いた発泡ウレタンの他に、気泡径の小さい発泡ポリスチレンを用いてもよい。この連通気泡を有する発泡ポリスチレンの製造方法については、国際特許ＷＯ９６／０７９４２（特表平８−５０３７２０号公報、特願平６−５０９０６２号公報）および国際特許ＷＯ９６／１６８７６（特表平８−５０５８９５号公報、特願平６−５１７００１号公報）に記載されているように、まず、平均分子量が２×１０⁵のポリスチレンに主発泡剤である炭酸ガスと、例えばＨＦＣ−１３４ａ(1,1,1,2-tetrafluoroetane)やＨＦＣ−１５２ａ(1,1-difluoroetane)などの補助発泡剤を好適に用いて、押出し混合、発泡、フォームの急冷、によって連通気泡の含有率が１００％に近く、しかも気泡径の小さな発泡ポリスチレンを得ることができる。
【００３３】
次に、本発明に係り、図３に示す如くの断面構造を有し、図１に示す真空断熱部材１を用いた断熱箱体２１の製造方法として、図２に示した工程図に基づいて説明する。まず、外箱１５の任意の位置に連通気泡の発泡ウレタンから成る板状部材２２を配設した上に真空断熱部材１を載置（Ｓ−１１）し、これを別途、真空成形法などによって成形した内箱１８と勘合させて外殻を完成させる（Ｓ−１２）とともに、冷媒回路部品や固定用アンカーなどの部材を装着して断熱箱体２１の外殻を組み立てる（Ｓ−１３）。
【００３４】
この外殻を、背面を上にした状態で発泡ウレタン１７の発泡圧による変形防止を目的に治具に固定された断熱箱体２１において、上になった背面板上にあって両側壁上に位置する注入口から開口部の両側壁面であるフランジ部分に向かって発泡ウレタン１７の原料液を落下させて注入する。発泡ウレタン１７は数秒後に発泡を開始して泡状でこの間隙内を流動して充填するので、樹脂の硬化が完了したならば、治具から取り出すことによって発泡ウレタン１７の断熱部材を形成した断熱箱体２１が得られる（Ｓ−１４）。得られた断熱箱体２１には、内装部品と冷媒回路部品を用いて製品組立を行い（Ｓ−１５）、製品検査を完了すれば（Ｓ−１６）、製品である冷蔵庫として完成する（Ｓ−１７）。
【００３５】
発泡ウレタン１７などの発泡樹脂を外殻内の真空断熱部材１を配設した残りの薄い間隙内を発泡しながら流動させることによって完全に充填させるには困難を伴い、充填量を増すなどの方法によって発泡に寄与するガスが膨張するときの高い圧力条件を確保して発泡する。このため、真空断熱部材１は、それを保持した外箱１５および内箱１８で構成される外殻面に押し付けられた状態となるので、真空断熱部材１および外殻に変形を来して意匠性を損なうことがないよう、棚受けなどの凹凸を有する内箱１８に配設するよりも、平面形状で構成された外箱１５の内面に配設する方が好適であり、本実施の形態では、外殻である外箱１５面と真空断熱部材１の間隙に発泡断熱材である板状部材２２を配設して一層の安定して保持できる面を確保し、各々の当接面を両面テープで固定した形態を備えて断熱箱体２１を構成している。
【００３６】
また、内箱１８および真空断熱部材１を配設した外箱１５から成る空隙内に発泡ウレタン１７が真空断熱部材１を乗り越えて真空断熱部材１の後方部分を充填するとき、発泡液の流れに乱れを生じ、巻き込んだ空気を排出することが出来ずにボイドを形成して残留させることがある。しかしながら、本実施の形態では、当該部分には連通気泡を含んで成る発泡ウレタンを用いて成る板状部材２２を真空断熱部材１と外箱１５との間隙に備えたことにより、巻き込んだ空気を発泡圧によって、板状部材２２が有する連通気泡内に押し込むようにして排除できるので、ボイドのない発泡ウレタン１７を形成できる。
【００３７】
実施の形態２．
本実施の形態は、真空断熱部材１の配設位置に係るものである。図４は本発明の実施の形態２による断熱箱体の断面構造を示す要部断面図である。
【００３８】
図４において、断熱壁１４を構成する内箱１８には棚受けなどの凹凸部分があるものの、外箱１５との間で構成される間隙が発泡方向に広いテーパ状を成しているが、外箱１５と真空断熱部材１の間に厚さを調整してテーパ形状にした板状部材２３を配設し、外箱１５に配設された真空断熱部材１と内箱１８との間隙が一定である平行な状態を確保している。
【００３９】
また、真空断熱部材１の配設位置は、その端辺部分１６が板状部材からはみ出すことのない位置にある。従って、板状部材２３は真空断熱部材１よりも広い投影面を備えている。
【００４０】
断熱箱体２１の形成方法は実施の形態１と同様であって、図２に示した工程図に基づいて述べれば、まず、真空断熱部材１を外箱１５の任意の位置に配設した板状部材２３上に載置（Ｓ−１１）し、これを内箱１８と勘合させて外殻を完成させる（Ｓ−１２）とともに、必要な関連部材を装着して組み立てる（Ｓ−１３）。この外殻内に発泡ウレタン１７の原料混合液を上方位置の注入口から断熱壁の間隙に落下させて注入する。発泡ウレタン１７が泡状でこの間隙内充填して樹脂の硬化完了後に取り出す（Ｓ−１４）ことにより断熱箱体２１を得る。その後、関連部品を用いて製品組立を行い（Ｓ−１５）、製品検査を行った（Ｓ−１６）後に製品が完成する（Ｓ−１７）。
【００４１】
上記工程によって得た断熱箱体２１は、図４に示すようなテーパ形状を成す板状部材２３を用いて構成されており、その効果について以下に詳述すると、まず、ここで用いた断熱箱体２１は内容積が１２０Ｌの冷蔵庫用であり、図５の外箱の展開図に示す位置である断熱壁の中央位置に配設し、残りの空隙に発泡ウレタン１７を充填したものである。得られた断熱箱体２１には、従来の断熱箱体に用いられている既存の扉を設置して庫内を密封して不要な熱の漏洩を防止した。
【００４２】
ここで用いる真空断熱部材１は実施の形態１と同様手段によって得たものであり、大きさが４００×４００mm、厚さが１５mmである。また、外箱１５面と真空断熱部材１の間隙に配設する板状部材２３は、厚さが５mmの連通気泡を備える発泡樹脂である発泡ウレタンから成る。
【００４３】
本実施の形態において得られた断熱箱体２１の効果を検証するため以下のように試料を試作した。まず、第１の試料は、図４に示した如くの厚さをテーパ形状にした板状部材２３を配設して外箱１５との間で構成される間隙を調整して、外箱１５に配設された真空断熱部材１と内箱１８との間隙が平行な状態を確保したうえ、真空断熱部材１よりも広い投影面を備えて真空断熱部材１の端辺１６が板状部材２３からはみ出さない大きさのものである。また、第２の試料は、第１の試料に対して、板状部材の対向する面が平行になったものを用い、従って、外箱１５に配設された真空断熱部材１と内箱１８との間隙が断熱箱体２１の奥部方向になるほど広いテーパ状態となる。また、第３の試料は、第１の試料と異なるのは、図４に併記したように真空断熱部材の端辺１６ａが外箱面に接触して配設されている。
【００４４】
また、比較試料には、上記実施試料と同じ大きさの断熱箱体を用いて板状部材を介することの無い従来の真空断熱部材の配設形態であって、図５に示した位置の外箱面に直接、両面テープを用いて固定し、これに発泡ウレタンを充填したものを用いた。
【００４５】
以上の試作によって得られた断熱箱体の断熱性能を評価するため、熱漏洩量を測定した。熱漏洩量の測定は、庫内に発熱量Ｑが既知のヒータを内部に投入して断熱箱体内部の空気温度Tinと断熱箱体外部の空気温度Toutを測定し、式（２）を用いて単位温度差当たりの熱漏洩量すなわち熱コンダクタンスＫを求めた。なお、この断熱箱体に用いる扉は、関わる断熱箱体に用いたものを再利用して熱漏洩に生じる過度な差異を排除して、不要な誤差が発生しないようにした。
【００４６】
Ｋ＝Ｑ／（Tin−Tout）（２）
【００４７】
表１に、本発明の配設方法により真空断熱部材を配設した断熱箱体である実施例、および従来の配設方法による比較例である断熱箱体の各々について、その断熱性能として示す熱漏洩量の測定結果を記した。
【００４８】
【表１】

【００４９】
上記結果のように、外箱１５に板状部材２３を介して真空断熱部材１を固定した本実施の形態による何れの断熱箱体２１における熱漏洩量とも、外箱１５に真空断熱部材１を直接固定した従来の断熱箱体よりも少ない熱漏洩量であって、断熱性能に優れていることを確認した。
【００５０】
外箱１５に真空断熱部材１を配した従来の断熱箱体の場合、外箱１５から真空断熱部材１に伝熱が直接的に行われた後、真空断熱部材１の包装材内のアルミ箔を伝熱し、さらに端辺部分にある包装材の溶着部分および対面の真空断熱部材表面を経て、もう一つの断熱材である発泡ウレタン１７部分を貫通して庫内側に流入するので、断熱箱体の見掛けの断熱性能が低下を来すことになる。このうち、包装材内にあるアルミ箔は非常に高い熱伝導率を有するので、端辺部分を通過する伝熱量が殆ど減衰しない状態で、相対的に薄い断熱厚さである発泡ウレタン１７との当接面に到達する。
【００５１】
これに対し、本実施の形態に基づく真空断熱部材１は、外箱１５から真空断熱部材１への伝熱が、断熱機能を備えた板状部材２３を介して行われるので、真空断熱部材１への伝熱量が大幅に抑制した。この結果、たとえ伝熱量が殆ど減衰しない端辺部分にあっても、真空断熱部材１の包装材に達する伝熱量が少ないので、もう一つの断熱材である発泡ウレタン１７に達する熱量は、上述した従来例と比較して大幅に減少した。
【００５２】
また、厚さが奥行き方向に同じで平行である面を備える板状部材を設けた試料２に対して、断熱箱体の開口部側が薄く、反開口部側が厚いテーパ形状の断面形状を備える板状部材２３を設けた試料１は、ほぼ同じ熱漏洩量であった。各試料とも断熱箱体の角部にある真空断熱部材と板状部材の端部にはボイドの発生が無いものの、充填に供した発泡ウレタン１７内部に流動の乱れを示す渦状のボイドがわずかにあり、それによれば、試料２が発泡ウレタンの流動の乱れを示す渦状のものが多いのに対して、試料１では流れの方向を示す曲折のみの形状であった。
【００５３】
これは、発泡ウレタン１７の流れが薄い空隙部分から厚い空隙部分へ移行する際、発熱によって生じた熱が放散し難くなって、内部温度が上昇し、これに伴う樹脂化の促進に起因して流動性が低下したと考える。このようにして発泡ウレタン１７が流動の乱れを有する場合、当該部分に内部歪みが残存し易くなって収縮を来して外観変形を招くことがあるので、発泡ウレタン１７が充填する空隙を均一にするような形状を備えた試料１の板状試料のほうが、試料２の板状試料の形状に比較して好適である。
【００５４】
また、第３の試料では、真空断熱部材の端辺部分にある包装材の溶着部分が外箱面に当接することになるので、熱漏洩量が実施試料の中で大きいのは溶着部分を経由して受熱して真空断熱部材の受熱量が増加したことに起因する。
【００５５】
以上のように、発泡ウレタン１７などで構成される断熱部材の厚さに極度の薄い部分を作ることの無いように、外箱１５と真空断熱部材１の間隙に配する板状部材２３の厚さを調整したものを使用すること、および、真空断熱部材１の包装材の溶着部分が外箱に当接することの無いようにすること、が熱漏洩量の低減に一層、有効であることが確認できた。
【００５６】
また、本実施の形態では、受熱面である外箱面に真空断熱部材を配設して成る態様を示したが、これにこだわることなしに、内箱面などの放熱面に相当する部位に板状部材を介して配設しても、同様の効果を得る。
【００５７】
また、本実施の形態では、発泡ウレタンを用いたが、連通気泡を含んだ発泡樹脂、例えば発泡スチレンを用いても良く、これらの連通気泡を含む多孔体の使用によって、端部にボイドなどの空隙の発生を防止できる。
【００５８】
以上に述べた本発明の実施の形態において示したような冷蔵庫用などの断熱構造体に限定されるものではなく、例えば車載用小型冷蔵庫やプレハブ式簡易冷蔵庫、保冷車やパイプや建築物の保温材など、保温および保冷用製品の断熱用部品への応用も可能である。
【００５９】
【発明の効果】
以上のように、この発明によれば外箱の構成要素である外壁部材と、内箱の構成要素である内壁部材と、外壁部材の内壁側に配設され、連通気泡を備える発泡樹脂からなる板状部材と、内壁部材の外壁側に向き合う板状部材の面に設けられた真空断熱部材と、外壁部材と内壁部材との間を充填する断熱部材とを備えるので、真空断熱部材が外壁部材からの受熱を直接的に行うことを防止できるので、優れた断熱性能を得るとともにボイドなどの空隙の発生を抑制できる効果がある。
【００６０】
また、外箱の構成要素である外壁部材と、内箱の構成要素である内壁部材と、内壁部材の外壁側に配設され、連通気泡を備える発泡樹脂からなる板状部材と、外壁部材の内壁側に向き合う板状部材の面に設けられた真空断熱部材と、外壁部材と内壁部材との間を充填する断熱部材とを備えるので、真空断熱部材が外壁部材からの受熱を直接的に行うことを防止できるので、優れた断熱性能を得るとともにボイドなどの空隙の発生を抑制できる効果がある。
【００６０】
外箱の構成要素である外壁部材と、内箱の構成要素であり、外壁部材の内壁側と平行でない外壁側を有する内壁部材と、外壁部材の内壁側に配設され、内側部材に向き合う面に真空断熱部材が設けられ、真空断熱部材の内壁部材の外壁側と向き合う面が内壁部材の外壁側と平行になるように設けられる断熱材からなる板状部材と、外壁部材と内壁部材との間を充填する断熱部材とを備えるので、断熱部材が充填される空隙を均一にすることができ、当該部分に内部歪みが残存して外観変形を招くことがなくなる。
【００６１】
また、板状の断熱部材が、連通気泡を備えて成る発泡樹脂であることにより、断熱部材が発泡しながら流動して空隙内を充填するときに真空断熱部材端部で発生する流動の乱れによって巻き込まれた空気を吸収することが出来るので、ボイドなどの空隙の発生を抑制できる。
【００６２】
また、空間を充填する断熱部材が、発泡樹脂であることにより、断熱部材が外壁部材、内壁部材、板状部材及び真空断熱部材の間で構成される空間に充填されるとき、その充填作業が効率よく、安定して行うことができる。
【００６３】
また、真空断熱部材の外側端部が壁部材に当接することを防止するように配設したことにより、真空断熱部材の外側端部が受熱面を通じ、厚さ方向に貫通する熱を抑制して断熱性能を向上することができる。
【図面の簡単な説明】
【図１】本発明の実施の形態による断熱箱体を示す概略斜視図である。
【図２】本発明の実施の形態による断熱箱体を含む冷蔵庫等の製品の製造工程を示す工程図である。
【図３】本発明の実施の形態１による断熱箱体の断面構造を示す要部断面図である。
【図４】本発明の実施の形態２による断熱箱体の断面構造を示す要部断面図である。
【図５】断熱箱体における真空断熱部材の配設位置を示す外壁部材の展開図である。
【図６】真空断熱部材の内部構造を示す断面図である。
【図７】真空断熱部材の製造方法を示す工程図である。
【図８】真空包装機の内部構造を示す説明図である。
【図９】真空断熱部材の包装材に用いるシート材の構造を示す断面図である。
【図１０】断熱箱体における伝熱の経路を示す説明図である。
【図１１】従来の断熱箱体に使用される真空断熱部材の包装材の端部の構造を示す説明図である。
【符号の説明】
１真空断熱部材、１４断熱壁、１５外箱、１６端辺部分、
１７発泡ウレタン、１８内箱、２１断熱箱体、
２２、２３板状部材。[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a heat insulating box used for a refrigerator or the like, and more particularly to arrangement of a vacuum heat insulating member provided in a wall constituting the heat insulating box.
[0002]
[Prior art]
  Conventionally, the wall surface of a heat insulating box used for a refrigerator or the like is formed by covering the outer wall with a thin metal plate such as an iron plate, forming the inner surface part with a resin molded product, and injecting and filling urethane foam into the gap. Has been. Hydrochlorofluorocarbons 1,1-dichloro-1-fluoroethane (HCFC141b) has been used as a foaming agent for urethane foam, which is a heat insulating material. Hydrofluorocarbons and hydrocarbons that are not contained are used.
[0003]
  For example, JP-A-2-235882 discloses hydrofluorocarbons such as 1,1,1,3,3-pentafluoropropane (HFC245fa) and 1,1,1,4,4,4-hexafluorobutane (HFC356mffm). For example, Japanese Patent Laid-Open No. 3-152160 discloses a method for producing foamed urethane in which a hydrocarbon such as cyclopentane is applied as a foaming agent. However, the heat insulating properties of these urethane foams are 19 to 20 mw / MK, which is clearly inferior to the heat insulating properties of 16 mw / MK when using chlorofluorocarbons used before the regulation of ozone-depleting substances. .
[0004]
  For this reason, the technique which applies the vacuum heat insulation member which can obtain 5-8 mw / mK which is a heat insulation performance 2 times or more of the foaming urethane which is the conventional porous body is proposed. As the heat transfer component of the vacuum heat insulating member, the heat transfer component of the porous body has excellent heat insulation performance due to the elimination of the gas in the pores and the elimination of the heat transmitted through the gas. To be expressed.
[0005]
  That is, a porous material having many pores is formed by foaming a resin or the like, or is formed by forming voids between many particles. For this reason, when the heat transfer of the porous material is schematically shown, it can be expressed as a sum of four components as shown in the following formula (1). That is, the solid heat transfer component (λs) transmitted through the solid portion constituting the porous body, the gas heat transfer component (λg) similarly transmitted through the gas component, the radiant heat transfer component (λr) generated by heat ray radiation as electromagnetic waves, and the pores The convection component (λc) transmitted by the convection motion of the gas. Among these, the convection component (λc) is used to increase the amount ratio of the resin of the foamed resin in order to obtain the strength that the porous material does not deform over time even under atmospheric pressure. As a result of taking measures such as filling, λc may be ignored because the pores are sized so that the gas in the pores does not cause convective motion, and as a result, the remaining 3 It is substantially constituted by components (λs, λg, λr).
[0006]
    λ = λs + λg + λr + λc (1)
[0007]
  However, in the vacuum heat insulating member, since the gas in the pores of the porous body inside the vacuum heat insulating member is eliminated to make a vacuum state, as described above, the heat transfer component of the porous body including the continuous pores similar to the foamed resin is used. Since the heat transfer component (λg) due to one gas could be eliminated, it is possible to express an excellent heat insulating performance as compared with a heat insulating material such as a foamed resin.
[0008]
  Such a vacuum heat insulating member 1 has a structure shown in FIG. 6 and is a core material having a role of maintaining a shape inside a vacuum maintained by suppressing the invasion of gas from the outside by the packaging material 2. As 3, a porous material is inserted. That is, the getter agent 4 is a porous material similar to a foamed resin such as foamed urethane which is a heat insulating material, but eliminates the gas in the pores to ensure a vacuum state and absorbs an external gas that invades over time. As a result of maintaining a high vacuum state, the heat transfer component due to the gas is eliminated, and excellent heat insulation performance is exhibited. Here, in order to achieve further improvement in heat insulation performance, the amount of heat transmitted through the substance is suppressed by using a substance that does not easily transfer heat to the constituent material and reducing the contact area between the materials. In addition, it is effective to suppress radiant heat transfer by providing a smaller gap.
[0009]
  Next, the manufacturing method of the vacuum heat insulating member 1 will be described with reference to the process diagram shown in FIG. 7. The packaging material 2 is heat-sealed in three directions in advance (S-1) and communicated within the bag. The core material 3 composed of foamed urethane having bubbles is inserted (S-2). This is fixed in the chamber of the vacuum packaging machine 5 as shown in FIG.^-1~ 1x10^-3After evacuation to ensure a vacuum atmosphere of about Torr (S-3), the remaining end which is the insertion port 6 is fused using a pressurizer 7 and a heater 8 incorporating a heater (S-). 4) Seal by. Finally, after sealing the insertion port of the core material 3 and cooling it to below the melting point of the thermoplastic resin used for the inner layer, if the vacuum inside the vacuum packaging machine 5 is released and returned to normal pressure, the vacuum heat insulating member 1 Is taken out (S-5).
[0010]
  The sheet material used for the packaging material 2 of the vacuum heat insulating member 1 used here has a structure as shown in FIG. That is, the inner layer used for sealing the edge is a heat-sealing layer 9 made of a thermoplastic resin such as polyethylene or polypropylene that can be thermally welded, and the outermost layer is made of a resin such as nylon or polyester that is resistant to scratches. A gas shielding layer 11 made of a metal foil such as aluminum for completely blocking the intrusion of outside air is formed on the substrate 12 which is a high strength film such as polyethylene terephthalate. A multilayer sheet 13 that is configured to have a fixed state and is obtained by laminating and integrating materials constituting each layer of the sheet shape by an adhesive or welding, is a foaming agent or in the air Gas is difficult to permeate.
[0011]
  However, the gas shielding layer 11 disposed for the purpose of shielding gas from outside the system in the multilayer sheet as a packaging material includes extensibility in consideration of handling and workability of the packaging material 2. Aluminum with excellent flexibility is provided in a thin film state by vapor deposition or foil arrangement. However, a thin film such as an aluminum foil generally used as the gas shielding layer 11 has a thickness of about 10 as compared with a resin sheet which is another constituent material.^ThreeSince it has twice as high thermal conductivity, it can be equivalent to a thickness of several millimeters to several tens of millimeters by replacing the thermal conductivity with a general resin. Rather than the thickness direction in which the heat transfer is shielded, the influence of the heat transfer in the surface direction caused by the heat transfer of the substance alone is a non-negligible amount.
[0012]
  That is, in the vacuum heat insulating member 1 in which the packaging material 2 wraps around the core material 3, for example, in the case of the heat transfer path in the refrigerator shown in FIG. 10, the vacuum in which the heat of the outside air abuts from the outer box 15 that is the outer wall material. After passing through the surface of the packaging material 2 (heat receiving surface) of the heat insulating member 1, penetration heat is dominant in the thickness direction at the center of the surface of the vacuum heat insulating member 1, whereas the edge portions of the vacuum heat insulating member 1 are at both ends. 16 and further passing through the surface of the packaging material 2 which is embedded inside the opposing heat insulating wall, another foamed urethane 17 which is a porous heat insulating material, which is another heat insulating material, and an inner box 18 which is an inner wall material. It spreads in the warehouse via. The influence of thermal crosslinking, which is such a heat transfer path, is dominant, and therefore eliminating this is an important factor in obtaining a heat insulating structure that takes advantage of the characteristics of the vacuum heat insulating member.
[0013]
  In order to deal with such problems, Japanese Patent Application Laid-Open No. 59-146993 proposes that the amount of heat transfer be suppressed by setting the thickness of the aluminum foil disposed on the inner layer of the packaging material 2 to 20 microns or less. ing.
[0014]
  In Japanese Patent Laid-Open No. 5-302696, as shown in FIG. 11, a gas-shielding layer is provided in the gap between the heat-sealing layer 9 and the surface layer 10 in the heat-sealing portion 19 which is a portion where the heat receiving surface and the heat radiating surface are joined. By using the packaging material 2 that does not arrange the aluminum foil 20 that is 11 in the multilayer sheet on either side, by avoiding overlapping with the other multilayer sheet on which the aluminum foil 20 is arranged, We have proposed a structure that can suppress the effects of thermal crosslinking by preventing heat transfer smoothly.
[0015]
  However, in the method disclosed in Japanese Patent Laid-Open No. 59-146993, the gas shielding performance is prevented from deteriorating due to defects such as pinholes generated in the process of spreading the aluminum foil into a thin film. In this publication, the lower limit film thickness is 7 microns. However, even if this lower limit film thickness is provided, if it is replaced with a resin used for a packaging material from the relationship of thermal conductivity, it reaches 10 mm, and cannot be ignored as an effect of thermal crosslinking.
[0016]
  Further, the method disclosed in JP-A-5-302696 requires extremely high accuracy for joining two multilayer sheets in the production of packaging materials, and has a problem in practicality. In other words, if a misalignment occurs when joining the two multilayer sheets, the portion where only the resin layer having a large gas permeability coefficient is present on one side of the packaging material without the aluminum foil will open widely. Become. Therefore, gas in the atmosphere easily enters from the part where the gas shielding performance is greatly inferior, and the vacuum inside the packaging material is greatly reduced in a short period of time, so that the heat insulation performance deteriorates in a short period of time. .
[0017]
  In order to cope with such a problem, Japanese Utility Model Laid-Open No. 63-2080 discloses a vacuum heat insulating member fixed to an outer shell surface through a plurality of fixtures using a porous heat insulating material, etc. It shows a means for suppressing the amount of heat transfer that causes the above-mentioned thermal crosslinking by filling urethane foam into a gap formed between the fixture and the outer wall material. In other words, since the voids are filled with urethane foam, the vacuum heat insulating member forms a heat insulating box body that is not in direct contact with the outer box, and heat transfer to the vacuum heat insulating member is not smoothly performed. Can be suppressed.
[0018]
[Problems to be solved by the invention]
  The conventional heat insulation box is configured as described above, and in order to maintain the position where it is disposed to withstand the pressure of urethane foam filled between the outer box on the heat receiving surface side and the vacuum heat insulation member, the outer wall It is necessary to increase the adhesion area of the fixture to the material and the vacuum heat insulating member, and as a result, in the portion corresponding to the rear where the urethane foam flows, the flow is disturbed to leave air and generate a gap, Insulation performance may be reduced. In addition, the difference in shrinkage between the fixture and the foamed urethane may cause local deformation, and may form irregularities on the surface of the outer box and impair the appearance design.
[0019]
  The present invention has been made to solve the above-described problems, and obtains a heat insulation box body with excellent heat insulation efficiency by suppressing the amount of heat transfer to the vacuum heat insulation member, and obtains a heat insulation box body with small external deformation. For the purpose.
[0020]
[Means for Solving the Problems]
  It is a component of the outer boxAn outer wall member;It is a component of the inner boxAn inner wall member;A plate-like member made of foamed resin provided with communicating bubbles, disposed on the inner wall side of the outer wall member, a vacuum heat insulating member provided on the surface of the plate-like member facing the outer wall side of the inner wall member, an outer wall member and an inner wall member; And a heat insulating member filling the space.
[0021]
  It is a component of the outer boxAn outer wall member;It is a component of the inner boxAn inner wall member;A plate-like member made of a foamed resin provided with communicating bubbles, disposed on the outer wall side of the inner wall member, a vacuum heat insulating member provided on the surface of the plate-like member facing the inner wall side of the outer wall member, and the outer wall member and the inner wall member; And a heat insulating member filling the space.
[0021]
  An outer wall member that is a component of the outer box, an inner wall member that is a component of the inner box and has an outer wall side that is not parallel to the inner wall side of the outer wall member, and a surface that is disposed on the inner wall side of the outer wall member and faces the inner member A plate-shaped member made of a heat insulating material provided such that a surface facing the outer wall side of the inner wall member of the vacuum heat insulating member is parallel to the outer wall side of the inner wall member, and the outer wall member and the inner wall member A heat insulating member filling the gap.
[0022]
  Also, plate-like membersIs made of foamed resin with open cells.
[0023]
  Also,The heat insulating member is a foamed resin.
[0024]
  Moreover, it arrange | positions so that the outer side edge part of a vacuum heat insulation member may contact | abut on a wall member.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
  An embodiment of the present invention will be described with reference to the drawings.
  In the figure, the same or equivalent parts as those in the prior art are designated by the same reference numerals and the description thereof is omitted. FIG. 1 is a schematic perspective view showing a heat insulation box according to an embodiment of the present invention. Moreover, FIG. 2 is process drawing which shows the manufacturing process of products, such as a refrigerator containing the heat insulation box by embodiment of this invention.
Embodiment 1 FIG.
  FIG. 3 is a cross-sectional view of the main part showing the cross-sectional structure of the heat insulation box according to Embodiment 1 of the present invention. Reference numeral 1 denotes a vacuum heat insulating member, 15 denotes an outer box (outer wall member) made of a bent product such as a thin steel plate, and 17 denotes an outer box 15, an inner box 18, a plate-like member 22, and a vacuum heat insulating member 1. A foamed urethane (heat insulating member) filled in a space formed between them, 18 is an inner box (inner wall member) which is a molded product obtained by vacuum forming an ABS resin sheet, and 22 has open cells. It is a plate-like processed product obtained by cutting urethane foam, and is a plate-like member disposed in the gap between the vacuum heat insulating member 1 fixed to the inner surface of the outer box and the inner surface of the outer box 15.
[0026]
  The vacuum heat insulating member 1 used here is formed in a plate shape of, for example, 500 mm × 600 mm, and is a plate obtained by cutting urethane foam having open cells by a double-sided tape provided at an arbitrary interval on the inner surface of the outer box. It is fixed via a plate-like member that is a processed product.
[0027]
  Next, the manufacturing method of the heat insulation box will be described in detail. First, the same means as the manufacturing process diagram of the conventional heat insulation box shown in FIG. 7, that is, a packaging material is formed (S-1). After inserting the core material into the core (S-2), vacuuming (S-3) and heat sealing of the end side (S-4) are performed, and finally the vacuum heat insulating member is taken out (S-5), A vacuum heat insulating member was obtained through the process.
[0028]
  In the vacuuming step, the packaging material 2 with the core material 3 inserted into the vacuum packaging machine is fixed to form a vacuum atmosphere, and gases such as air remaining in the pores of the core material 3 are exhausted. The degree of vacuum is 1 torr or less, preferably 5 × 10^-2Secure torr. Since a gap is formed between the packaging material 2 and the core material 3 for exhausting the gas in the pores, not only the end of the insertion port but also the surface of the core material 3 can be exhausted, so the target vacuum Reaching the degree is easily done.
[0029]
  In addition, the packaging material 2 used here is a bag in which three sides are linearly heat-sealed using a multi-layer sheet using high-density polyethylene capable of heat-sealing as an inner layer used for sealing the edges. Each of the core material 3 and the core material 3 were obtained by cutting foamed urethane having open cells into a plate shape.
[0030]
  The vacuum heat insulating member 1 used here is formed in a plate shape of, for example, 500 mm × 600 mm, and urethane foam having open air bubbles is cut by a double-sided tape provided at an arbitrary interval on the inner surface of the outer box 15. It is fixed via a plate-like member 22. In addition, even if the foamed resin provided with the open cell used for the core material 3 of the vacuum heat insulating member 1 and the open resin provided with the open cell used for the plate-like member 22 are the same, they are different. Also good.
[0031]
  Further, the foamed urethane plate-shaped molded article having open cells as the core material 3 will be described. First, in the foamed urethane raw material liquid, mainly a polyol, a catalyst, a foam stabilizer, a foam breaker, a foaming agent, etc. Two liquids, a premix liquid obtained by mixing the auxiliary agent and an isocyanate liquid mainly composed of isocyanate, are mixed and foamed. Any size obtained by mixing the specified amount of these two liquids using an impeller-type mixer or the like, and keeping the temperature at 30 ° C. to 60 ° C., preferably 40 ° C. to 50 ° C., in time for foaming started after several seconds. In this embodiment, after being put into an aluminum mold having a side of 600 mm and a depth of 45 mm, the board-shaped molded product is left to stand for 5 minutes or more until the curing is completed in a sealed state. Obtained. In order to form a plate-like core material 3 from the bulk of a foamed urethane molded product having open cells, the outer periphery and the surface layer portion of an arbitrary thickness are cut in order to eliminate the surface layer portion where many independent bubbles remain. As a result, a 450 mm × 450 mm × 15 mm cut product was obtained.
[0032]
  For the core material 3 of the vacuum heat insulating member 1, foamed polystyrene having a small cell diameter may be used in addition to the urethane foam used here. Regarding the method for producing the expanded polystyrene having open cells, International Patent WO96 / 077942 (Japanese Patent Publication No. 8-503720, Japanese Patent Application No. 6-509062) and International Patent WO96 / 168776 (Japanese Patent Application Laid-Open No. 8-505895). First, the average molecular weight is 2 × 10 6 as described in Japanese Patent Application No. 6-517001.^FiveOf carbon dioxide, the main foaming agent, and an auxiliary foaming agent such as HFC-134a (1,1,1,2-tetrafluoroetane) or HFC-152a (1,1-difluoroetane) By mixing, foaming, and rapid cooling of the foam, it is possible to obtain a foamed polystyrene having an open cell content of nearly 100% and a small cell diameter.
[0033]
  Next, according to the present invention, the manufacturing method of the heat insulating box 21 having the cross-sectional structure as shown in FIG. 3 and using the vacuum heat insulating member 1 shown in FIG. 1 is based on the process diagram shown in FIG. explain. First, the vacuum heat insulating member 1 is placed (S-11) on a plate-like member 22 made of open-cell foamed urethane at an arbitrary position of the outer box 15, and this is separately separated by a vacuum forming method or the like. The outer shell is completed by fitting with the molded inner box 18 (S-12), and the outer shell of the heat insulating box 21 is assembled by attaching members such as refrigerant circuit parts and fixing anchors (S-13).
[0034]
In the heat insulation box 21 fixed to a jig for preventing deformation due to the foaming pressure of the urethane foam 17 with the back face up, the outer shell is on the back plate on the upper side and on both side walls. The raw material liquid of the urethane foam 17 is dropped and injected from the injection port located toward the flange portions which are both side walls of the opening. Since the foamed urethane 17 starts to foam after a few seconds and flows into the gap in the form of foam, it fills in the gap. Therefore, when the resin has been cured, it is removed from the jig to form a heat insulating member for the foamed urethane 17. A box 21 is obtained (S-14). The obtained heat insulation box 21 is assembled using the interior parts and the refrigerant circuit parts (S-15), and if the product inspection is completed (S-16), the product as a refrigerator is completed (S16). -17).
[0035]
  It is difficult to completely fill a foamed resin such as urethane foam 17 by foaming and flowing in the remaining thin gap in which the vacuum heat insulating member 1 in the outer shell is disposed. Thus, foaming is ensured at a high pressure condition when the gas contributing to foaming expands. For this reason, since the vacuum heat insulating member 1 is pressed against the outer shell surface composed of the outer box 15 and the inner box 18 that hold the vacuum heat insulating member 1, the vacuum heat insulating member 1 and the outer shell are deformed to bring about a design. In this embodiment, it is preferable to dispose on the inner surface of the outer box 15 having a planar shape, rather than disposing on the inner box 18 having unevenness such as a shelf holder so as not to impair the performance. Then, a plate-like member 22 that is a foam heat insulating material is disposed in the gap between the outer shell 15 surface that is the outer shell and the vacuum heat insulating member 1 to secure a surface that can be held more stably, and each contact surface is The heat insulation box 21 is configured with a form fixed with a double-sided tape.
[0036]
  Further, when the foamed urethane 17 gets over the vacuum heat insulating member 1 and fills the rear portion of the vacuum heat insulating member 1 into the gap formed by the inner box 18 and the outer box 15 in which the vacuum heat insulating member 1 is disposed, Disturbance may occur, and the entrained air may not be discharged and voids may be formed and remain. However, in the present embodiment, the plate-like member 22 made of foamed urethane containing communication bubbles is provided in the gap in the gap between the vacuum heat insulating member 1 and the outer box 15, so that the entrained air is removed. Since the foaming pressure can be eliminated by pushing into the communicating bubbles of the plate-like member 22, the urethane foam 17 without voids can be formed.
[0037]
Embodiment 2. FIG.
  The present embodiment relates to the arrangement position of the vacuum heat insulating member 1. FIG. 4 is a cross-sectional view of the main part showing the cross-sectional structure of the heat insulation box according to Embodiment 2 of the present invention.
[0038]
  In FIG. 4, although the inner box 18 constituting the heat insulating wall 14 has an uneven portion such as a shelf holder, the gap formed between the outer box 15 and the outer box 15 forms a wide taper in the foaming direction. A plate-like member 23 having a taper shape with a thickness adjusted between the outer box 15 and the vacuum heat insulating member 1 is disposed, and a gap between the vacuum heat insulating member 1 and the inner box 18 disposed in the outer box 15 is provided. A constant parallel state is ensured.
[0039]
  Moreover, the arrangement | positioning position of the vacuum heat insulation member 1 exists in the position where the edge part 16 does not protrude from a plate-shaped member. Therefore, the plate-like member 23 has a wider projection surface than the vacuum heat insulating member 1.
[0040]
  The method for forming the heat insulation box 21 is the same as that of the first embodiment. If the process is shown in the process diagram shown in FIG. 2, first, the plate in which the vacuum heat insulation member 1 is disposed at an arbitrary position of the outer box 15. It is placed on the shaped member 23 (S-11), and this is fitted with the inner box 18 to complete the outer shell (S-12), and necessary related members are mounted and assembled (S-13). A raw material mixture of urethane foam 17 is dropped into the gap between the heat insulating walls from the upper injection port and injected into the outer shell. The urethane foam 17 is foamed and filled in the gap, and is taken out after the resin is cured (S-14) to obtain the heat insulation box 21. Thereafter, product assembly is performed using related parts (S-15), and product inspection is performed (S-16), and then the product is completed (S-17).
[0041]
  The heat insulation box 21 obtained by the above process is configured by using a plate-like member 23 having a taper shape as shown in FIG. 4. The effect will be described in detail below. First, the heat insulation box used here. The body 21 is for a refrigerator having an internal volume of 120 L, and is disposed at the center position of the heat insulating wall, which is the position shown in the developed view of the outer box in FIG. 5, and the remaining gap is filled with urethane foam 17. The obtained heat insulation box 21 was provided with an existing door used in a conventional heat insulation box, and the inside of the cabinet was sealed to prevent unnecessary heat leakage.
[0042]
  The vacuum heat insulating member 1 used here is obtained by the same means as in the first embodiment, and has a size of 400 × 400 mm and a thickness of 15 mm. Further, the plate-like member 23 disposed in the gap between the outer box 15 surface and the vacuum heat insulating member 1 is made of urethane foam, which is a foamed resin having open air bubbles with a thickness of 5 mm.
[0043]
  In order to verify the effect of the heat insulating box 21 obtained in the present embodiment, a sample was made as a prototype as follows. First, in the first sample, a plate-like member 23 having a taper shape as shown in FIG. 4 is arranged to adjust the gap formed between the outer case 15 and the outer case 15. In addition, a state in which the gap between the vacuum heat insulating member 1 and the inner box 18 disposed in parallel is ensured, and a projection surface wider than the vacuum heat insulating member 1 is provided, and the end 16 of the vacuum heat insulating member 1 is a plate-like member 23. It is of a size that does not protrude. Further, the second sample is a plate in which the opposing surfaces of the plate member are parallel to the first sample. Therefore, the vacuum heat insulating member 1 and the inner box 18 disposed in the outer box 15 are used. The larger the gap is, the deeper the taper is. The third sample is different from the first sample in that the end 16a of the vacuum heat insulating member is in contact with the outer box surface as shown in FIG.
[0044]
  In addition, the comparative sample is a conventional vacuum heat insulating member arrangement form using a heat insulating box having the same size as the above-described sample and without a plate-like member, and is outside the position shown in FIG. It fixed to the box surface directly using the double-sided tape, and what filled this with urethane foam was used.
[0045]
  In order to evaluate the heat insulation performance of the heat insulation box obtained by the above trial production, the amount of heat leakage was measured. The amount of heat leakage is measured by putting a heater with a known calorific value Q inside the chamber, measuring the air temperature Tin inside the heat insulation box and the air temperature Tout outside the heat insulation box, and using equation (2) The amount of heat leakage per unit temperature difference, that is, the thermal conductance K was obtained. In addition, the door used for this heat insulation box was made to reuse the thing used for the heat insulation box concerned, and the excessive difference which arises in a heat leak was eliminated, and the unnecessary error did not generate | occur | produce.
[0046]
    K = Q / (Tin-Tout) (2)
[0047]
  Table 1 shows the heat shown as the heat insulation performance of each of the heat insulation box that is a heat insulation box provided with a vacuum heat insulation member according to the arrangement method of the present invention and the comparative example according to the conventional arrangement method. The measurement result of the amount of leakage was described.
[0048]
[Table 1]

[0049]
  As in the above results, the heat insulation amount in any heat insulation box body 21 according to this embodiment in which the vacuum heat insulation member 1 is fixed to the outer box 15 via the plate-like member 23, the vacuum heat insulation member 1 is attached to the outer box 15. The amount of heat leakage was smaller than that of a conventional heat insulation box that was directly fixed, and it was confirmed that the heat insulation performance was excellent.
[0050]
  In the case of a conventional heat insulating box body in which the vacuum heat insulating member 1 is arranged in the outer box 15, after heat transfer is directly performed from the outer box 15 to the vacuum heat insulating member 1, the aluminum foil in the packaging material of the vacuum heat insulating member 1 The heat insulating box body passes through the welded portion of the packaging material on the end portion and the surface of the vacuum heat insulating member on the opposite side, passes through the urethane foam 17 portion, which is another heat insulating material, and flows into the inside of the cabinet. The apparent thermal insulation performance will be reduced. Among these, since the aluminum foil in the packaging material has a very high thermal conductivity, the amount of heat transfer passing through the end portion is hardly attenuated, and the foamed urethane 17 having a relatively thin heat insulation thickness is used. Reach the contact surface.
[0051]
  On the other hand, in the vacuum heat insulating member 1 based on this Embodiment, since the heat transfer from the outer box 15 to the vacuum heat insulating member 1 is performed via the plate-shaped member 23 provided with the heat insulating function, the vacuum heat insulating member 1 The amount of heat transfer to was greatly suppressed. As a result, even if the heat transfer amount is at the end portion where the heat transfer amount hardly attenuates, the heat transfer amount reaching the packaging material of the vacuum heat insulating member 1 is small. Compared with the conventional example, it was significantly reduced.
[0052]
  A plate having a taper-shaped cross-sectional shape in which the opening side of the heat insulation box is thin and the non-opening side is thick with respect to the sample 2 provided with the plate-like member having the same and parallel thickness in the depth direction. Sample 1 provided with the shaped member 23 had almost the same amount of heat leakage. In each sample, there is no generation of voids at the ends of the vacuum heat insulating member and the plate member at the corners of the heat insulating box, but there is a slight amount of vortex voids that show turbulence in the foamed urethane 17 used for filling. Yes, according to the sample 2, the sample 2 has a vortex shape which shows the disturbance of the flow of the urethane foam, whereas the sample 1 has only a bent shape indicating the flow direction.
[0053]
  This is because when the flow of the foamed urethane 17 shifts from the thin gap portion to the thick gap portion, the heat generated by the heat generation becomes difficult to dissipate, the internal temperature rises, and the accompanying resinization is accelerated. I think the liquidity has declined. In this way, when the foamed urethane 17 has flow disturbance, internal distortion tends to remain in the part and the shrinkage may be caused and the appearance may be deformed. Therefore, the void filled with the foamed urethane 17 is made uniform. The plate-like sample of the sample 1 having such a shape is more suitable than the shape of the plate-like sample of the sample 2.
[0054]
  Further, in the third sample, the welded portion of the packaging material at the end portion of the vacuum heat insulating member comes into contact with the outer box surface, so that the amount of heat leakage is large among the working samples via the welded portion. This is due to the fact that the amount of heat received by the vacuum heat insulating member is increased.
[0055]
  As described above, the thickness of the plate-like member 23 disposed in the gap between the outer box 15 and the vacuum heat insulating member 1 so as not to make an extremely thin portion in the thickness of the heat insulating member made of urethane foam 17 or the like. It is more effective in reducing the amount of heat leakage to use the one with adjusted thickness and to prevent the welded portion of the packaging material of the vacuum heat insulating member 1 from coming into contact with the outer box. It could be confirmed.
[0056]
    Further, in the present embodiment, a mode in which the vacuum heat insulating member is disposed on the outer box surface which is the heat receiving surface is shown, but without being particular about this, the portion corresponding to the heat radiating surface such as the inner box surface is provided. Even if it is arranged via a plate-like member, the same effect is obtained.
[0057]
  In the present embodiment, urethane foam is used. However, a foamed resin containing open cells, such as foamed styrene, may be used. By using a porous body containing open cells, a void or the like is formed at the end. Generation of voids can be prevented.
[0058]
  It is not limited to a heat insulating structure for a refrigerator or the like as shown in the embodiment of the present invention described above, for example, a small vehicle-mounted refrigerator, a prefabricated simple refrigerator, a cold car, a pipe or a building and the heat insulation. It is also possible to apply heat insulation and cold insulation products such as wood to heat insulation parts.
[0059]
【The invention's effect】
  As described above, according to the present invention,It is a component of the outer boxAn outer wall member;It is a component of the inner boxAn inner wall member;A plate-like member made of foamed resin provided with communicating bubbles, disposed on the inner wall side of the outer wall member, a vacuum heat insulating member provided on the surface of the plate-like member facing the outer wall side of the inner wall member, an outer wall member and an inner wall member; With a heat insulating member that fills the space betweenSince the vacuum heat insulating member can be prevented from directly receiving heat from the outer wall member, excellent heat insulating performance is obtained.In addition, the generation of voids and other voids can be suppressed.effective.
[0060]
  It is also a component of the outer boxAn outer wall member;It is a component of the inner boxAn inner wall member;A plate-like member made of a foamed resin provided with communicating bubbles, disposed on the outer wall side of the inner wall member, a vacuum heat insulating member provided on the surface of the plate-like member facing the inner wall side of the outer wall member, and the outer wall member and the inner wall member; Since the vacuum heat insulating member can be prevented from directly receiving heat from the outer wall member, it has an effect of obtaining excellent heat insulating performance and suppressing generation of voids such as voids. is there.
[0060]
  An outer wall member that is a component of the outer box, an inner wall member that is a component of the inner box and has an outer wall side that is not parallel to the inner wall side of the outer wall member, and a surface that is disposed on the inner wall side of the outer wall member and faces the inner member A plate-shaped member made of a heat insulating material provided such that a surface facing the outer wall side of the inner wall member of the vacuum heat insulating member is parallel to the outer wall side of the inner wall member, and the outer wall member and the inner wall member Since the space is provided with a heat insulating member that fills the space, the gap filled with the heat insulating member can be made uniform, so that internal distortion does not remain in the portion and appearance deformation does not occur.
[0061]
  Also plate-likeHeat insulationWhen the member is a foamed resin with open air bubbles, it absorbs the air trapped by the turbulence of the flow generated at the end of the vacuum heat insulating member when the heat insulating member flows while foaming and fills the gap. Therefore, generation of voids such as voids can be suppressed.
[0062]
  Also,Filling the spaceWhen the heat insulating member is a foamed resin, when the heat insulating member is filled in the space constituted by the outer wall member, the inner wall member, the plate-like member and the vacuum heat insulating member, the filling operation is efficiently and stably performed. It can be carried out.
[0063]
  In addition, by arranging so as to prevent the outer end of the vacuum heat insulating member from coming into contact with the wall member, the outer end of the vacuum heat insulating member can be suppressed from passing through the heat receiving surface in the thickness direction. Thermal insulation performance can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a heat insulation box according to an embodiment of the present invention.
FIG. 2 is a process diagram illustrating a manufacturing process of a product such as a refrigerator including a heat insulating box according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view of a main part showing a cross-sectional structure of a heat insulating box according to Embodiment 1 of the present invention.
FIG. 4 is a cross-sectional view of a main part showing a cross-sectional structure of a heat insulating box according to a second embodiment of the present invention.
FIG. 5 is a development view of the outer wall member showing the position of the vacuum heat insulating member in the heat insulating box.
FIG. 6 is a cross-sectional view showing the internal structure of the vacuum heat insulating member.
FIG. 7 is a process diagram showing a method for manufacturing a vacuum heat insulating member.
FIG. 8 is an explanatory view showing the internal structure of the vacuum packaging machine.
FIG. 9 is a cross-sectional view showing the structure of a sheet material used for a packaging material for a vacuum heat insulating member.
FIG. 10 is an explanatory diagram showing a heat transfer path in the heat insulating box.
FIG. 11 is an explanatory view showing a structure of an end portion of a packaging material of a vacuum heat insulating member used in a conventional heat insulating box.
[Explanation of symbols]
    1 vacuum heat insulating member, 14 heat insulating wall, 15 outer box, 16 edge part,
    17 urethane foam, 18 inner box, 21 heat insulation box,
    22, 23 Plate-like members.

Claims

An outer wall member which is a component of the outer box ;
An inner wall member that is a component of the inner box ;
A plate-like member that is disposed on the inner wall side of the outer wall member and is made of a foamed resin having open cells;
A vacuum heat insulating member provided on the surface of the plate member facing the outer wall side of the inner wall member;
A heat insulation box comprising a heat insulation member filling a space between the outer wall member and the inner wall member .

An outer wall member which is a component of the outer box ;
An inner wall member that is a component of the inner box ;
A plate-like member that is disposed on the outer wall side of the inner wall member and is made of a foamed resin having communicating bubbles; and
A vacuum heat insulating member provided on the surface of the plate-like member facing the inner wall side of the outer wall member;
A heat insulation box comprising a heat insulation member filling a space between the outer wall member and the inner wall member .

An outer wall member which is a component of the outer box;
An inner wall member that is a component of the inner box and has an outer wall side that is not parallel to the inner wall side of the outer wall member;
A vacuum heat insulating member is provided on the inner wall side of the outer wall member and faces the inner member, and a surface of the vacuum heat insulating member facing the outer wall side of the inner wall member is parallel to the outer wall side of the inner wall member. A plate-like member made of a heat insulating material,
A heat insulation box comprising a heat insulation member filling a space between the outer wall member and the inner wall member .

The heat insulating box according to claim 3, wherein the plate-like member is made of a foamed resin having open cells .

The heat insulation box according to any one of claims 1 to 4, wherein the heat insulation member is a foamed resin .

6. The heat insulation box according to claim 1 , wherein the heat insulation box is disposed so as to prevent the outer end of the vacuum heat insulation member from coming into contact with the wall member.