[0009] 以下，參照圖式說明相關於本發明的實施型態之冰箱1A,1B,1C。又，在以下的說明，以圖1所示的「上下」、「左右」、「前後」方向為基準來進行說明。此外，在以下舉6門冰箱為例進行說明，但不限定於6門冰箱。此外，於各實施型態，針對同一構成賦予同一符號而省略重複之說明。
[0010]
(第1實施型態)
圖1係相關於第1實施型態的冰箱的外觀立體圖。
[0011] 如圖1所示，冰箱1A，例如由上側起，配置冷藏室2、製冰室3、上段冷凍室4、下段冷凍室5以及蔬菜室6而構成的。又，製冰室3與上段冷凍室4，係左右排列設置的。冷藏室2，具備分割為左右的左右對開式的冷藏室門2a,2b。
[0012] 此外，冰箱1A，其箱外與箱內是藉由在內部填充發泡絕熱材構成的絕熱箱體10而隔開的。此絕熱箱體10，除了發泡絕熱材以外具備真空絕熱材50(圖3)，藉由此真空絕熱材50提高絕熱性。絕熱箱體10，具有構成外輪廓的外箱11、以及構成冷藏室2、製冰室3、上段冷凍室4、下段冷凍室5、蔬菜室6等貯藏食品等的各貯藏室之內箱12。
[0013] 此外，冰箱1A，具備包含壓縮機(空壓機)、冷凝器(condenser，未圖示)、毛細管(減壓手段，未圖示)以及冷卻器(蒸發器(evaporator))之習知的冷凍循環。
[0014] 此外，冰箱1A，於冷藏室2之庫內，具備操作面板20(單元構件)。此操作面板20，設於庫內的左側面。又，操作面板20的位置，不限定於左側面，設於右側之側面亦可。
[0015] 此外，操作面板20，具有呈現矩形狀的表面構件21，於表面構件21設有複數個(在本實施型態為6個)按壓式的操作按鈕22。此外，操作面板20，比設在冷藏室2的隔棚2c位於更為前側。
[0016] 圖2係顯示冰箱的內部之正面圖。又，圖2係取下門2a,2b以及內部的隔棚2c等的狀態。
[0017] 如圖2所示，絕熱箱體10的外箱11，為薄板厚度之鋼板製的，構成冰箱本體(絕熱箱體10)的筐體。此外，外箱11，從鋼帶起使用成形輥等，使左右兩側的側面板11a,11b及頂面板11c成形為一體，而以螺絲固定等方式安裝底面板(未圖示)及背面板11d(參照圖3)。
[0018] 絕熱箱體10的內箱12，係採用把一枚樹脂薄板加熱同使抵在鼓風器進行延伸，將彼放入金屬模具成形為容器狀之真空成形法來成形。此外，內箱12，係把左側的側面壁12a、右側的側面壁12b、背面壁12c、頂面壁12d(參照圖1)、底面壁12e(參照圖1)成形為一體者。
[0019] 圖3為圖2之A-A線剖面圖。
[0020] 如圖3所示，絕熱箱體10，於水平方向之剖面視角是被形成為ㄈ字形。外箱11的側面板11a,11b，於前後方向平行地延伸。
[0021] 內箱12的側面壁12a，具有由背面側(後側)朝向正面側(前側)以接近於外箱11的側面板11a(外側面)的方式和緩地傾斜的傾斜面12a1。此傾斜面12a1，是為了確保脫離金屬模具之脫模性，被稱為所謂的拔模角(draft angle) 。在被形成此傾斜面12a1(拔模角)之面(側面壁12a)設有操作面板20。又，針對側面壁12b，也與側面壁12a左右對稱而設傾斜面。
[0022] 此外，絕熱箱體10的內側(壁之內部)，設有真空絕熱材50。此真空絕熱材50，被貼附於外箱11的側面板11a(外板)的內面。此外，真空絕熱材50，其前端位於比操作面板20更靠正面側(近側,前側)，其後端延伸配置至側面板11a之約略後端。
[0023] 此外，真空絕熱材50，以內袋材料(未圖示)內包構成被配置於中央部的芯材的無機纖維集合體之玻璃絨層、吸著劑等，以鋁箔等具有氣體障壁性的外包材真空包裝。
[0024] 內袋材料(未圖示)，使用聚乙烯膜，或者聚丙烯膜、聚乙烯對苯二甲酸酯膜、聚丁烯對苯二甲酸酯膜等。總之，內袋材料，使用吸濕性低可以熱融接，外洩氣體(氣體洩漏)少者。
[0025] 於吸著劑，使用細孔且捕捉水分或氣體分子的物理吸附式之合成沸石等。又，吸著劑亦可不是合成沸石，只要可以吸附水分或氣體者即可，也可以使用矽凝膠或氧化鈣、氯化鈣、氧化鍶等以化學反應吸附水分或氣體之化學反應型吸著劑。
[0026] 關於外包材，作為表面層設吸濕性低的聚丙烯膜，作為防濕層在聚乙烯對苯二甲酸酯膜上設鋁蒸鍍層。接著，氣體障壁層，在乙烯-乙烯醇共聚物共聚合物膜上設鋁蒸鍍層，以與防濕層的鋁蒸鍍層面對面的方式貼合。
[0027] 在本實施型態，使面板狀(平板狀)的真空絕熱材50貼附於側面板11a(外板)的內壁面，在被形成於側面板11a(外板)與側面壁12a(內板)之間的空間被填充硬質胺甲酸乙酯泡沫等之發泡絕熱材。
[0028] 圖4為圖3之重要部位擴大圖。
[0029] 如圖4所示，操作面板20，被構成為具備：被設置操作按鈕22(參照圖1)的表面構件21、設於表面構件21的背面側的控制基板31(電路基板)、收容控制基板31同時固定表面構件21的基板收容部41。又，操作按鈕22(參照圖1)，例如為按壓操作方式者，是在變更冷藏室2、製冰室3、上段冷凍室4、下段冷凍室5、蔬菜室6等的庫內溫度時操作的。
[0030] 表面構件21，具有被設置操作按鈕22(參照圖1)的面板部21a、與從此面板部21a的背面的外周緣部朝向外箱的側面板11a延伸的肋片21b。此外，表面構件21，是藉著在貫通側面壁12a(傾斜面12a1)而形成的矩形狀的安裝孔12f插入肋片21b而固定於基板收容部41。此外，面板部21a，呈現比安裝孔12f的開口面積更大的矩形狀，以面板部21a的外周緣部21r的全體抵接於安裝孔12f的開口緣部12g的全體的方式構成。藉此，藉由表面構件21封閉安裝孔12f之全體，使安裝孔12f無法由外部(庫內)看到。
[0031] 此外，表面構件21，考慮到拔模角(draft angle)，以正面側(前側)比背面側(後側)更由側面壁12a的表面往庫內側(朝向庫內的寬幅方向的中央)突出的方式構成。此外，表面構件21(面板部21a)的表面21a1，被構成為與真空絕熱材50約略平行(或是平行)。又，約略平行，包含了平行，同時是比以表面21a1與傾斜面12a1構成的傾斜更接近於平行的方向。
[0032] 控制基板31，以被實裝各種電氣零件或電子零件的四角板狀的電路基板(可適度略稱為「基板」)構成，位於表面構件21的肋片21b的內側。換句話說，以控制基板31藉由肋片21b包圍的方式構成。隨著操作面板20的操作選單增加(多機能化)基板也大型化。以來自控制基板31的訊號，被送至設於絕熱箱體10的頂面的主基板，由主基板控制庫內溫度的方式構成。
[0033] 基板收容部41，被配置於側面壁12a的背側(絕熱箱體10的內側)，被構成為具有收容控制基板31的凹部42，與由此凹部42的開口緣部沿著側面壁12a的背面延伸的鍔部43。
[0034] 凹部42，具有與控制基板31平行配置的底面部42a，與由此底面部42a的周緣部朝向側面壁12a立起延伸的側面部42b，以朝向安裝孔12f開口的方式構成。此外，凹部42，被構成為從正面側(前側)的開口起算的深度H1比從背面側(後側)的開口起算的深度H2更淺(H2＞H1)。
[0035] 此外，凹部42的底面部42a，以外箱11側的背面42c，與真空絕熱材50成約略平行(或平行)的方式構成。藉此，底面部42a的背面42c與真空絕熱材50之間的間隙S，由背面側到正面側變得均一。又，所謂約略平行，包含了平行，同時是比以背面42c與傾斜面12a1構成的傾斜更接近於平行的方向。
[0036] 此外，凹部42的底面部42a，以外箱11側的背面42c與外箱11(側面板11a)成約略平行(或平行)的方式構成。藉此，在側面板11a的背面安裝真空絕熱材50的場合，可以使底面部42a的背面42c與真空絕熱材50之間的間隙S，由背面側到正面側變得均一。
[0037] 圖5為圖2之B-B線剖面圖。
[0038] 如圖5所示，表面構件21的肋片21b，被形成控制基板31的外周緣部抵接之抵接部21d。藉此，可以使由表面構件21的背面起算的高度位置總是一定。
[0039] 基板收容部41的凹部42，被形成由底面部42a朝向表面構件21突出的補強部41s。補強部41s，被形成為圓筒狀，形成為由底面部42a的中央突出。此外，補強部41s的先端41s1，突出至與側面壁12a成為同一平面的位置。
[0040] 然而，被收容於基板收容部41的收容物很小的話，可以縮小基板收容部41，即使在基板收容部41的背面填充胺甲酸乙酯(發泡絕熱材)，施加於基板收容部41的發泡壓力也很小。但是，操作面板增加而基板大型化的話，會有隨著胺甲酸乙酯的發泡壓力而使基板變形的可能性。在此，填充胺甲酸乙酯時，必須把供防止基板收容部變形之用的治具由側面壁的表面側抵接。藉由如此在基板收容部41設補強部41s，可以抑制發泡壓力導致的變形。又，補強部41s的先端41s1，只要延伸到碰到治具的位置即可。
[0041] 此外，在基板收容部41被形成補強部41s的緣故，於控制基板31的中央，被形成可插通補強部41s的貫通孔31a。藉此，即使補強部41s由底面部42a突出到與側面壁12a同平面之面，也可以把控制基板31收容於基板收容部41。
[0042] 圖6為由背側所見之從操作面板留下控制基板而取下基板收容部的狀態之平面圖。
[0043] 如圖6所示，控制基板31，於平面俯視呈矩形狀，被配置在形成於表面構件21的背面之肋片21b的內側。控制基板31的外周緣部，位於肋片21b的附近。
[0044] 此外，控制基板31，藉由形成在表面構件21的背面之爪部21c,21c,21d,21d卡住控制基板31的邊緣。藉此，使控制基板31確實保持於表面構件21。
[0045] 爪部21c,21c，被形成於控制基板31的上部，與肋片21b一體形成，相互於前後方向上隔開配置。此外，爪部21c，被形成於肋片21b的控制基板31側的壁面。爪部21d,21d，由表面構件21的背面突出形成，相互於前後方向上隔開配置。
[0046] 肋片21b，具有沿著控制基板31的上邊部31b形成的上部肋片21e，與沿著控制基板31的前後兩側的側邊部31c,31c形成的側部肋片21f,21g，以及沿著控制基板31的下邊部31d形成的下部肋片21h,21i，平面俯視被構成為約略ㄈ字形(約略C字形)。下部肋片21h,21i，由側部肋片21f,21g的下端朝向相互對向的前後方向較短地形成。於下部肋片21h,21i的先端下面，有延伸於表面構件21的厚度方向(與圖6的紙面正交的方向)之突起部21h1,21i1突出形成。
[0047] 於表面構件21的背面，與下端部被形成延伸於上下方向的排水溝21j,21j,21k,21k。排水溝21j,21j位於前後方向的後側。排水溝21k,21k位於前後方向的前側。此外，排水溝21j,21k，於表面構件21的背面，被構成為導水管狀(約略半圓狀)的缺口。此外，排水溝21j,21j，被形成於與下部肋片21h在上下方向不重疊的位置。排水溝21k,21k，被形成於於與下部肋片21h在上下方向不重疊的位置。
[0048] 此外，上部肋片21e，具有由前後方向的中央(正面平視寬幅方向的中央)朝向前方(寬幅方向的一方)下降的方式傾斜的傾斜路徑21e1，與朝向後方(寬幅方向的另一方)下降的方式傾斜的傾斜路徑21e2。
[0049] 圖7為操作面板之縱剖面圖。
[0050] 如圖7所示，上部肋片21e，具有由表面構件21的背面側朝向表面側下降的傾斜面部21e3。藉此，即使水(結露水)等由操作面板20與側壁面12a之間隙，流入到上部肋片21e，也不會流到基板收容部41的底面部42a側，所以可保護控制基板31。
[0051] 然而，冷藏室2內(庫內)為低溫環境，暖空氣會隨著門2a,2b的開閉而進入冷藏室2，有結露之虞，有比要防止(保護)控制基板31不受結露影響。在此，藉著使肋片21e的形狀成為圖6及圖7所說明的形狀，可以保護控制基板31不受結露影響。亦即，如圖6以虛線箭頭所表示的，在庫內發生結露而結露水由表面構件21的上部浸入表面構件21的背面側的場合，可以首先使結露水以上部肋片21e承接。此時，上部肋片21e具有傾斜路徑21e1,21e2，所以藉由傾斜路徑21e1,21e2使結露水流往前後方向(圖示之左右方向)。此外，此時，上部肋片21e具有傾斜面部21e3(參照圖7)，所以結露水不會流動低落到控制基板31側。
[0052] 接著，流動至上部肋片21e的前後方向的端部的結露水，藉由表面張力接觸於側部肋片21f,21g的外面同時往下方流動滴落。接著，流動至側部肋片21f,21g的下端的結露水，藉由表面張力接觸於下部肋片21h,21i的下面同時朝向內側方流動。接著，流到下部肋片21h,21i的先端的結露水，碰到被形成於下部肋片21h,21i的先端下面的突起部21h1,21i1，朝向下方滴落。接著，滴落的結露水，通過排水溝21j,21j,21k,21k，流出到表面構件21的外側。如此，藉著形成結露水流通的流道，可以保護控制基板31不受結露影響。
[0053] 其次，參照第1實施型態與比較例同時說明發明之作用效果。圖8為顯示操作面板與絕熱箱體之位置關係的概略圖，(a)為第1實施型態，(b)為比較例。
[0054] 圖8(b)所示之比較例，是使基板收容部141之背面142c仿效傾斜面12a1形成，同時使表面構件121的表面121a仿效傾斜面12a1形成之絕熱箱體100的場合。於如此構成的比較例，被形成於基板收容部141的背面142c與真空絕熱材50(表面50s)之間的間隙S100，係正面側的間隙比背面側的間隙變得更窄，正面側的間隙之發泡絕熱材的流動性惡化。此外，真空絕熱材50被基板收容部41推擠，發生真空絕熱材50的洩漏等問題。
[0055] 在此，在第1實施型態，如圖8(a)所示，使基板收容部41的背面42c與真空絕熱材50平行(約略平行)。亦即，針對由內箱12之側面壁12a往背側突出的部分(跳出量)，係使正面側的突出量(尺寸)a1比背面側的突出量(尺寸)b1還要少(小)。藉此，基板收容部41的背面42c與真空絕熱材50(表面50s)之間的間隙S，由背面側到正面側變得均一。結果，可以縮短真空絕熱材50與基板收容部41的背面42c(操作面板20的背面)之尺寸。此外，可以增大真空絕熱材50的厚度尺寸，可提高冰箱1A的絕熱性。此外，在第1實施型態，可以縮小基板收容部41與真空絕熱材50之間隙，所以可使冰箱1A的壁厚變薄(可縮短側面板11a與側面壁12a之距離)。藉著可使冰箱1A的壁厚變薄，可增加冷藏室2的庫內容量。
[0056] 此外，在第1實施型態，如圖8(a)所示，使基板收容部41的背面42c與側面板11a(外箱11)平行(約略平行)。藉此，可得到與使基板收容部41的背面42c與真空絕熱材50平行(約略平行)的場合同樣的效果。
[0057] 此外，於圖8(b)之比較例，使基板收容部141的背面142朝向以單點虛線L100所示的方向，使背面142c與真空絕熱材50約略平行的話，變得無法確保控制基板31的收容空間。
[0058] 在此，在第1實施型態，如圖8(a)所示，使表面構件21，形成為正面側比背面側更由側面壁12a(側面)往庫內側突出。亦即，針對由內箱12之側面壁12a往表側的突出，係使正面側的突出量(尺寸)a2比背面側的突出量(尺寸)b2還要多(大)。藉此，可以確保控制基板31的收容空間，使得基板收容部41的背面42c與真空絕熱材50構成為約略平行(或者平行)成為可能。結果，可以縮小真空絕熱材50與基板收容部41的背面42c(操作面板20的背面)之尺寸。此外，可以增大真空絕熱材50的厚度尺寸，可提高冰箱1A的絕熱性。此外，在第1實施型態，可以縮小基板收容部41與真空絕熱材50之間隙，所以可使冰箱1A的壁厚變小(可縮短側面板11a與側面壁12a之距離)。藉著可使冰箱1A的壁厚變薄，可增加冷藏室2的庫內容量。又，於基板收容部41的背面，不設往真空絕熱材50側延伸的肋片。藉此，可防止由於肋片接觸真空絕熱材50而使真空絕熱材50洩漏，此外沒有必要為了防止洩漏而使真空絕熱材50與基板收容部41的距離超過必要程度。在操作按鈕22不是觸碰式而是按壓式的場合特別有效。
[0059] 此外，在第1實施型態，於表面構件21被突出形成之側(正面側)之面的背面被形成凹部21t(參照圖6)(被雕入到邊緣部)。藉此，藉由形成凹部21t，表面構件21的背面緣部被形成鍔部，所以可提高表面構件21的強度。此外，可以有效利用操作面板20的內側的空間。
[0060] 此外，在第1實施型態，於表面構件21的背面，由控制基板31的上邊部31b通過側邊部31c延伸至下方的肋片(上部肋片21e及側部肋片21f,21g)被突出形成，上部肋片21e的上面具有由表面構件21的背面側朝向表面側下降的傾斜面部21e3(參照圖7)。藉此，可以防止結露水流入控制基板31，可以保護控制基板31，提高操作面板20的可信賴性。
[0061] 此外，在第1實施型態，上部肋片21e的上面，具有於正面俯視由寬幅方向中央朝向兩側下降的方式傾斜之傾斜路徑21e1,21e2。藉此，由操作面板20的上方浸入的水(液滴)，不會累積於上部肋片21e，可以導引至側部肋片21f,21g，可以保護控制基板31。
[0062] 此外，在第1實施型態，於表面構件21的背面，於上下方向的下端被形成排水溝21j,21k。藉此，萬一有水進入基板收容部41內，也可以由排水溝21j,21k排水，可以提高操作面板的可信賴性。
[0063] 此外，在第1實施型態，肋片21b未被形成於與排水溝21j,21k重疊於上下方向的位置。藉此，可以藉由肋片21b把水誘導至排水溝21j,21k。
[0064] 此外，在第1實施型態，被形成由基板收容部41的底面朝向表面構件21之側延伸的補強部41s。藉此，在填充發泡絕熱材時，可以防止基板收容部41的變形。
[0065] 然而，側面壁12a的傾斜面12a1，亦有些微成為R形狀(往庫內側成為凸起)的場合。這樣的場合，作為間隙對策，以使基板收容部41也同樣具有R形狀為佳。在此，在以下所示的第2實施型態及第3實施型態，藉著使側面壁12a之收容部61,81的安裝處所為平面，不需要使基板收容部61,81具有R形狀。
[0066]
(第2實施型態)
圖9為顯示第2實施型態之操作面板與絕熱箱體之位置關係的概略圖。
[0067] 如圖9所示，第2實施型態之冰箱1B，於側面壁12a之傾斜面12a1形成凹形狀的階差部12m。此階差部12m，具有由側面壁12a之開口部朝向側面板11a延伸的四角形狀的筒體12m1，與由此筒體12m1的先端朝向內方延伸的環狀部12m2。環狀部12m2，被形成為與真空絕熱材50約略平行。換句話說，環狀部12m2，被形成為與側面板11a約略平行。此外，階差部12m，於由側面壁12a之往背面側的突出量，係使正面側的突出量(尺寸)比背面側的突出量(尺寸)還要少(小)。
[0068] 表面構件51，具有朝向背面側突出的肋片52，肋片52的先端抵接於鍔部12m2的表面。
[0069] 基板收容部61，被構成為具有收容控制基板31的凹部62，與被形成於此凹部62的開口緣部的鍔部63。凹部62，被形成為背面62c與真空絕熱材50約略平行。鍔部63，抵接於環狀部12m2。
[0070] 在第2實施型態，可以使基板收容部61的背面62c與真空絕熱材50約略平行，所以可以使背面62c與真空絕熱材50之間的間隙S1均一。此外，在第2實施型態的表面構件51，形成為正面側比側面側更由側面壁12a的傾斜面12a1往庫內側突出。藉此，可以縮小真空絕熱材50與基板收容部61的背面62c(操作面板20的背面)之間隙。藉著如此使間隙縮小，可以增大真空絕熱材50的厚度尺寸，可提高冰箱1A的絕熱性。此外，在第2實施型態，可以縮小基板收容部61與真空絕熱材50之間隙，所以可使冰箱1A的壁厚變小(可縮短側面板11a與側面壁12a之距離)。藉著可使冰箱1A的壁厚變薄，可增加冷藏室2的庫內容量。
[0071]
(第3實施型態)
圖10為顯示第3實施型態之操作面板與絕熱箱體之位置關係的概略圖。
[0072] 如圖10所示，第3實施型態之冰箱1C，於側面壁12a之傾斜面12a1形成凸形狀的階差部12p。此階差部12p，具有由側面壁12a之開口部朝向庫內延伸的四角形狀的筒體12p1，與由此筒體12p1的先端朝向內方延伸的環狀部12p2。環狀部12p2，被形成為與真空絕熱材50約略平行。換句話說，環狀部12p2，被形成為與側面板11a約略平行。此外，階差部12p，於由側面壁12a之往表面側的突出量，係使正面側的突出量(尺寸)比背面側的突出量(尺寸)還要多(大)。
[0073] 表面構件71，具有朝向背面側突出的肋片72，肋片72的先端抵接於環狀部12p2的表面。
[0074] 基板收容部81，被構成為具有收容控制基板31的凹部82，與被形成於此凹部82的開口緣部的鍔部83。凹部82，被形成為背面82c與真空絕熱材50約略平行。鍔部83，抵接於環狀部12p2。
[0075] 在第3實施型態，可以使基板收容部81的背面82c與真空絕熱材50約略平行，所以可以使背面82c與真空絕熱材50之間的間隙S2均一。此外，在第2實施型態，表面構件71，被形成為正面側比側面側更由側面壁12a往庫內側突出。藉此，可以得到與第2實施型態同樣的效果。
[0076] 又，在第2實施型態舉以使側面壁12a為凹形狀的場合，在第3實施型態舉以使側面壁12a為凸形狀的場合為例進行說明，但不使其為凹形狀或凸形狀，單純使安裝處所構成為平面亦可。
[0077] 然而，使基板收容部41(以下稱為外殼)，與外板(側面板11a)之間的間隙縮小的話，於外殼與真空絕熱材50之間的間隙，也設想在該間隙的周圍放入胺甲酸乙酯(發泡絕熱材)而在中央附近不放入胺甲酸乙酯的狀態。此外，因操作面板20多機能化而使控制基板31大型化，收容控制基板31的外殼也大型化，變得容易受到胺甲酸乙酯填充時的發泡壓力的影響。發泡壓力與胺甲酸乙酯密度的關係，變得如圖11(a)所示。亦即，縮小間隙的話胺甲酸乙酯密度會上升，所以隨著胺甲酸乙酯密度的上升而發泡壓力變高。因此，會產生外殼等零件的損傷或變形等瑕疵。在此，為了避免這樣的瑕疵，胺甲酸乙酯密度(ρ)，滿足以下的關係式1，做成使用了滿足此式的密度的胺甲酸乙酯之冰箱。
[0078]
ρ：胺甲酸乙酯密度(kg/mm3
)
K：外殼剛性(N/mm)
A：進入外殼背面的胺甲酸乙酯與外殼之設置面積(mm2
)
又，外殼剛性K，如圖11(b)所示，在支撐了外殼外周及外殼內部的突起部之全部的狀態下，對其提供荷重F，為藉由(荷重F：N)/(變形量R：mm)所求出的數值。
[0079] 在如本實施型態這樣的構造，由於外殼使絕熱部變薄，減少胺甲酸乙酯的厚度，有胺甲酸乙酯密度上升的傾向。在此，在本實施型態，設想使胺甲酸乙酯密度成為45kg/m3
以上的場合。
[0080] 接著，說明式1的根據，由密度(ρ：kg/mm3
)與發泡壓力(P：MPa)的關係，發泡導致的變形量可以用下列(式2)的左邊來表示。接著，胺甲酸乙酯密度與發泡壓力的關係，根據發明人等進行的實驗結果，顯示如圖11(a)那樣的傾向。此外，為了防止由胺甲酸乙酯發泡壓力導致外殼等零件的損傷有必要滿足(式2)的關係。
[0081]
[發泡壓力]×[面積]/[外殼剛性]≦[容許值]･･････(式2)
接著，設想外殼與真空絕熱材的間隙為1.0mm程度的話，胺甲酸乙酯密度一般為500×10^9kg/mm3
程度。從以圖11(a)得到的關係式算出此場合之發泡壓力(MPa)，藉由CAE解析求出外殼剛性K，決定相當於(式2)的右邊的容許值。又，隨著今後的操作面板的多機能化，設想大小會變成2倍，或者藉著材料變更等，而預期外殼剛性K會變成1/4，容許值必須要有8倍程度。從而安全率為8。
藉由以上說明的以圖11(a)得到的關係式(式2)、考慮到安全率之容許值，導出(式1)，成為對應於外殼損傷或變形之胺甲酸乙酯密度的條件式。
[0082] 使絕熱箱體10的壁厚度變薄的場合，外殼與真空絕熱材之間隙必然變窄。例如，使間隙未滿10mm的話，胺甲酸乙酯密度很高，發泡壓力變高，變得容易變形。在此，藉著提供在收容基板(控制基板31)的外殼(基板收容部41)，與外板(或真空絕熱材50)之間至少在中央附近沒有胺甲酸乙酯(發泡絕熱材)中介的冰箱，可以抑制發泡壓力導致的變形，可節約為了寬裕度所要具有的空間。
[0083] 此外，如圖12所示，在外殼(基板收容部41)與真空絕熱材50之間設有中介構件90亦可。中介構件90，是為了抑制或防止發泡絕熱材的浸入之構件，可以適用軟質胺甲酸乙酯等海綿狀者，或是泡沫聚苯乙烯等。此外，把外殼與真空絕熱材50之間的距離設定為較窄的6mm以下的話，發泡絕熱材變得難以進入外殼與真空絕熱材50之間。
[0084] 此外，藉著設中介構件90，外殼與真空絕熱材50不直接接觸，所以可防止真空絕熱材50的洩漏。此外，中介構件90，亦可為塞住外殼與真空絕熱材50之間的間隙的壓縮性構件(把比原本的間隙尺寸更大者壓潰使其中介者)。又，作為壓縮性構件，可以適用泡沫聚苯乙烯、聚乙烯泡沫。此外，中介構件90，以發泡絕熱材不浸入者為佳。
[0085] 又，本發明不限定於前述之實施型態，也包含種種變形例。例如，在本實施型態，針對使操作面板20設於庫內的側面壁12a的傾斜面12a1的場合進行說明，但對於被設置庫內燈的頂面壁12d也可適用。或者是亦可適用於被搭載冰箱的上面的主基板的場所。或者是亦可適用於搭載IOT(Internet of Things)基板的場所。[0009] Hereinafter, the refrigerators 1A, 1B, and 1C related to the embodiment of the present invention will be described with reference to the drawings. In addition, in the following description, the "up and down", "left and right", and "front and rear" directions shown in FIG. 1 will be used as the reference. In addition, a 6-door refrigerator is taken as an example for description below, but it is not limited to a 6-door refrigerator. In addition, in each embodiment, the same symbol is assigned to the same configuration, and repeated description is omitted. [0010] (First Embodiment) FIG. 1 is a perspective view of the appearance of a refrigerator related to the first embodiment. [0011] As shown in FIG. 1, the refrigerator 1A is configured by arranging a refrigerating compartment 2, an ice making compartment 3, an upper freezing compartment 4, a lower freezing compartment 5, and a vegetable compartment 6 from the upper side, for example. In addition, the ice making compartment 3 and the upper freezing compartment 4 are arranged side by side. The refrigerator compartment 2 is provided with the left and right side-opening type refrigerator compartment doors 2a, 2b divided into left and right. [0012] In addition, in the refrigerator 1A, the outside of the box and the inside of the box are separated by a heat-insulating box 10 made of a foamed heat-insulating material filled inside. This heat-insulating box 10 is provided with a vacuum heat-insulating material 50 (FIG. 3) in addition to the foam heat-insulating material, and the vacuum heat-insulating material 50 improves heat insulation by this. The heat-insulating box body 10 has an outer box 11 constituting an outer contour, and an inner box 12 constituting each storage room such as the refrigerator compartment 2, the ice making compartment 3, the upper freezer compartment 4, the lower freezer compartment 5, and the vegetable compartment 6 for storing food and the like . [0013] In addition, the refrigerator 1A is equipped with the custom of including a compressor (air compressor), a condenser (condenser, not shown), a capillary tube (decompression means, not shown), and a cooler (evaporator). Known refrigeration cycle. [0014] In addition, the refrigerator 1A is provided with an operation panel 20 (unit member) in the storage of the refrigerating compartment 2. The operation panel 20 is arranged on the left side of the library. In addition, the position of the operation panel 20 is not limited to the left side, but may be provided on the right side. [0015] In addition, the operation panel 20 has a rectangular surface member 21, and a plurality of (6 in this embodiment) push-type operation buttons 22 are provided on the surface member 21. In addition, the operation panel 20 is located on the front side of the partition 2c provided in the refrigerator compartment 2. [0016] FIG. 2 is a front view showing the interior of the refrigerator. In addition, FIG. 2 is a state in which the doors 2a, 2b, and the internal partition 2c, etc., are removed. [0017] As shown in FIG. 2, the outer box 11 of the insulated box 10 is made of a thin-thick steel plate, and constitutes the cabinet of the refrigerator body (the insulated box 10). In addition, the outer box 11 uses forming rolls from a steel belt to form the side panels 11a, 11b and the top panel 11c on the left and right sides into one body, and the bottom panel (not shown) and the back panel are fixed by screws or the like. 11d (refer to Figure 3). [0018] The inner box 12 of the insulated box body 10 is formed by a vacuum forming method in which a resin sheet is heated and stretched against a blower, and then placed into a metal mold to form a container shape. In addition, the inner box 12 is formed by integrally molding the left side wall 12a, the right side wall 12b, the back wall 12c, the top wall 12d (refer to FIG. 1), and the bottom wall 12e (refer to FIG. 1). [0019] FIG. 3 is a cross-sectional view taken along line AA of FIG. 2. [0020] As shown in FIG. 3, the cross-sectional view of the insulated box 10 in the horizontal direction is formed into a U-shaped. The side panels 11a, 11b of the outer box 11 extend in parallel in the front-rear direction. [0021] The side wall 12a of the inner box 12 has an inclined surface 12a1 that is gently inclined from the back side (rear side) to the front side (front side) so as to be close to the side panel 11a (outer side) of the outer box 11. This inclined surface 12a1 is to ensure the releasability from the metal mold, and is called a so-called draft angle. The operation panel 20 is provided on the surface (side wall 12a) where this inclined surface 12a1 (draft angle) is formed. In addition, with respect to the side wall 12b, an inclined surface is provided bilaterally symmetrically with the side wall 12a. [0022] In addition, a vacuum insulation material 50 is provided on the inner side (inside of the wall) of the heat-insulating box body 10. This vacuum insulation material 50 is attached to the inner surface of the side panel 11a (outer panel) of the outer box 11. In addition, the front end of the vacuum insulation material 50 is located closer to the front side (near side, front side) than the operation panel 20, and the rear end thereof extends to the approximate rear end of the side panel 11a. [0023] In addition, the vacuum insulation material 50 includes an inner bag material (not shown) that encloses the glass wool layer, sorbent, etc., of the inorganic fiber aggregate constituting the core material arranged in the center portion, and has a gas barrier with aluminum foil or the like. Vacuum packaging with flexible packaging materials. [0024] The inner bag material (not shown) uses polyethylene film, or polypropylene film, polyethylene terephthalate film, polybutylene terephthalate film, or the like. In short, the inner bag material has low hygroscopicity, can be thermally welded, and has less leakage of gas (gas leakage). [0025] As the sorbent, a physical adsorption type synthetic zeolite that uses fine pores and captures moisture or gas molecules, etc. In addition, the sorbent may not be a synthetic zeolite, as long as it can adsorb water or gas. It is also possible to use silica gel, calcium oxide, calcium chloride, strontium oxide, and other chemical reaction type adsorbents that adsorb water or gas by chemical reaction.着剂. [0026] Regarding the outer covering material, a polypropylene film with low hygroscopicity is provided as a surface layer, and an aluminum vapor deposition layer is provided on a polyethylene terephthalate film as a moisture-proof layer. Next, the gas barrier layer is provided with an aluminum vapor deposition layer on the ethylene-vinyl alcohol copolymer copolymer film, and is bonded to the aluminum vapor deposition layer of the moisture-proof layer opposite to it. [0027] In this embodiment, a panel-shaped (flat plate-shaped) vacuum insulation material 50 is attached to the inner wall surface of the side panel 11a (outer panel), and is formed on the side panel 11a (outer panel) and the side wall 12a. The space between the (inner panels) is filled with foamed insulation such as rigid urethane foam. [0028] FIG. 4 is an enlarged view of the important parts of FIG. 3. [0029] As shown in FIG. 4, the operation panel 20 is configured to include: a surface member 21 provided with operation buttons 22 (refer to FIG. 1), a control board 31 (circuit board) provided on the back side of the surface member 21, The control board 31 is accommodated and the board accommodating portion 41 of the surface member 21 is fixed. In addition, the operation button 22 (refer to FIG. 1), for example, is a pressing operation mode, and is operated when changing the internal temperature of the refrigerating compartment 2, ice making compartment 3, upper freezing compartment 4, lower freezing compartment 5, vegetable compartment 6, etc. of. [0030] The surface member 21 has a panel portion 21a provided with operation buttons 22 (see FIG. 1), and ribs 21b extending from the outer peripheral edge portion of the back surface of the panel portion 21a toward the side panel 11a of the outer box. In addition, the surface member 21 is fixed to the substrate accommodating portion 41 by inserting the rib 21b into a rectangular mounting hole 12f formed through the side wall 12a (inclined surface 12a1). In addition, the panel portion 21a has a rectangular shape larger than the opening area of the mounting hole 12f, and is configured such that the entire outer peripheral edge portion 21r of the panel portion 21a abuts the entire opening edge portion 12g of the mounting hole 12f. Thereby, the entire mounting hole 12f is closed by the surface member 21, so that the mounting hole 12f cannot be seen from the outside (inside the library). [0031] In addition, in consideration of the draft angle of the surface member 21, the front side (front side) is greater than the back side (rear side) from the surface of the side wall 12a to the inside of the library (toward the width direction of the inside of the library). In the center). In addition, the surface 21a1 of the surface member 21 (panel portion 21a) is configured to be approximately parallel (or parallel) to the vacuum insulation material 50. In addition, it is approximately parallel, including parallel, and is a direction closer to parallel than the inclination formed by the surface 21a1 and the inclined surface 12a1. [0032] The control board 31 is composed of a quadrangular plate-shaped circuit board (which may be abbreviated as a “substrate” as appropriate) on which various electric parts or electronic parts are mounted, and is located inside the fins 21b of the surface member 21. In other words, it is configured such that the control board 31 is surrounded by the ribs 21b. As the operation menu of the operation panel 20 increases (multi-functionalization), the substrate is also enlarged. The signal from the control board 31 is sent to the main board provided on the top surface of the heat-insulating box 10, and the main board is configured to control the temperature in the compartment. [0033] The substrate accommodating portion 41 is arranged on the back side of the side wall 12a (inside the thermal insulation box 10), and is configured to have a recess 42 for accommodating the control board 31, and the opening edge of the recess 42 is along the side surface. The flange portion 43 extends from the back of the wall 12a. [0034] The recess 42 has a bottom surface 42a arranged in parallel with the control board 31, and a side surface 42b extending from the peripheral edge of the bottom surface 42a toward the side wall 12a, and is configured to open toward the mounting hole 12f. In addition, the recess 42 is configured such that the depth H1 from the opening on the front side (front side) is shallower than the depth H2 from the opening on the back side (rear side) (H2>H1). [0035] In addition, the bottom surface 42a of the recess 42 and the back surface 42c on the outer box 11 side are configured to be approximately parallel (or parallel) with the vacuum insulation material 50. Thereby, the gap S between the back surface 42c of the bottom surface part 42a and the vacuum insulation material 50 becomes uniform from the back side to the front side. In addition, the term "approximately parallel" includes parallel, and is a direction closer to parallel than the inclination formed by the back surface 42c and the inclined surface 12a1. [0036] In addition, the bottom surface 42a of the recess 42 is configured such that the back surface 42c on the outer box 11 side and the outer box 11 (side panel 11a) are approximately parallel (or parallel). With this, when the vacuum insulation material 50 is attached to the back surface of the side panel 11a, the gap S between the back surface 42c of the bottom surface 42a and the vacuum insulation material 50 can be made uniform from the back side to the front side. [0037] FIG. 5 is a cross-sectional view taken along line BB of FIG. 2. [0038] As shown in FIG. 5, the ribs 21b of the surface member 21 are formed as abutting portions 21d to which the outer peripheral edge portion of the control board 31 abuts. Thereby, the height position calculated from the back surface of the surface member 21 can always be constant. [0039] The recess 42 of the substrate accommodating portion 41 is formed with a reinforcing portion 41s protruding from the bottom surface portion 42a toward the surface member 21. The reinforcement part 41s is formed in a cylindrical shape, and is formed so that it may protrude from the center of the bottom surface part 42a. In addition, the tip 41s1 of the reinforcing portion 41s protrudes to a position that becomes the same plane as the side wall 12a. [0040] However, if the contents accommodated in the substrate accommodating portion 41 are small, the substrate accommodating portion 41 can be reduced even if urethane (foamed heat insulating material) is filled on the back of the substrate accommodating portion 41 and applied to the substrate accommodating The foaming pressure of the part 41 is also very small. However, if the number of operation panels increases and the size of the substrate increases, the substrate may be deformed due to the foaming pressure of the urethane. Here, when filling the urethane, it is necessary to abut the jig for preventing the deformation of the substrate accommodating portion from the surface side of the side wall. By providing the reinforcing portion 41s in the substrate accommodating portion 41 in this way, deformation due to foaming pressure can be suppressed. In addition, the tip 41s1 of the reinforcing portion 41s only needs to extend to the position where it hits the jig. [0041] In addition, because the reinforcing portion 41s is formed in the substrate accommodating portion 41, a through hole 31a through which the reinforcing portion 41s can be inserted is formed in the center of the control board 31. Thereby, even if the reinforcing portion 41s protrudes from the bottom surface portion 42a to the same plane as the side wall 12a, the control board 31 can be accommodated in the board accommodating portion 41. [0042] FIG. 6 is a plan view of a state where the control board is left from the operation panel and the board accommodating portion is removed as seen from the back side. [0043] As shown in FIG. 6, the control board 31 has a rectangular shape in a plan view, and is arranged inside the rib 21b formed on the back surface of the surface member 21. The outer peripheral edge of the control board 31 is located in the vicinity of the rib 21b. [0044] In addition, the control board 31 is clamped to the edge of the control board 31 by the claw portions 21c, 21c, 21d, 21d formed on the back surface of the surface member 21. Thereby, the control board 31 is surely held by the surface member 21. [0045] The claws 21c and 21c are formed on the upper part of the control board 31, are formed integrally with the rib 21b, and are arranged spaced apart from each other in the front-rear direction. In addition, the claw portion 21c is formed on the wall surface of the rib 21b on the control board 31 side. The claw portions 21d and 21d are formed by protruding from the back surface of the surface member 21, and are arranged to be spaced apart from each other in the front-rear direction. [0046] The rib 21b has an upper rib 21e formed along the upper edge portion 31b of the control board 31, and side rib pieces 21f, 21g formed along the side edges 31c, 31c of the front and rear sides of the control board 31 , And the lower ribs 21h, 21i formed along the lower side portion 31d of the control board 31 are formed in a roughly U-shape (approximately C-shape) in plan view. The lower fins 21h, 21i are formed by the lower ends of the side fins 21f, 21g short in the front and rear directions facing each other. Protruding portions 21h1,21i1 extending in the thickness direction of the surface member 21 (direction orthogonal to the paper surface of FIG. 6) are formed under the tips of the lower ribs 21h and 21i. [0047] On the back surface of the surface member 21, drainage grooves 21j, 21j, 21k, 21k extending in the vertical direction are formed with the lower end portion. The drains 21j, 21j are located on the back side in the front-rear direction. The drains 21k, 21k are located on the front side in the front-rear direction. In addition, the drainage grooves 21j and 21k are formed as water-conducting (approximately semicircular) notches on the back surface of the surface member 21. In addition, the drain grooves 21j and 21j are formed at positions that do not overlap with the lower fin 21h in the vertical direction. The drain grooves 21k and 21k are formed at positions that do not overlap with the lower rib 21h in the vertical direction. [0048] In addition, the upper rib 21e has an inclined path 21e1 that is inclined to descend from the center in the front-rear direction (the center in the front-view wide direction) toward the front (one side in the wide direction), and the inclined path 21e1 toward the rear (wide The other side of the direction) is an inclined path 21e2 that is inclined in a descending manner. [0049] FIG. 7 is a longitudinal sectional view of the operation panel. [0050] As shown in FIG. 7, the upper rib 21e has an inclined surface portion 21e3 that descends from the back side of the surface member 21 toward the front side. Thereby, even if water (condensed water) flows into the upper rib 21e from the gap between the operation panel 20 and the side wall surface 12a, it does not flow to the bottom surface 42a side of the substrate accommodating portion 41, so the control substrate 31 can be protected. [0051] However, the refrigerating compartment 2 (inside the storage) is in a low-temperature environment, and warm air enters the refrigerating compartment 2 with the opening and closing of the doors 2a and 2b. There is a risk of condensation. Affected by condensation. Here, by making the shape of the rib 21e into the shape described in FIGS. 6 and 7, the control board 31 can be protected from condensation. That is, as shown by the dotted arrow in FIG. 6, when condensation occurs in the tank and the condensation water enters the back side of the surface member 21 from the upper part of the surface member 21, the condensation water may first be received by the upper fin 21e. At this time, the upper fin 21e has an inclined path 21e1,21e2, so the dew condensation water flows in the front-rear direction (the left-right direction in the figure) by the inclined path 21e1,21e2. In addition, at this time, since the upper fin 21e has an inclined surface part 21e3 (refer to FIG. 7), the dew condensation water does not flow down to the control board 31 side. [0052] Next, the condensed water that has flowed to the end of the upper fin 21e in the front-rear direction contacts the outer surfaces of the side fins 21f and 21g by surface tension while flowing downward and dripping. Next, the dew condensation water flowing to the lower ends of the side fins 21f and 21g flows inwardly while contacting the lower surfaces of the lower fins 21h and 21i by surface tension. Next, the dew condensation water flowing to the tips of the lower fins 21h, 21i hits the protrusions 21h1,21i1 formed under the tips of the lower fins 21h, 21i, and drops downward. Then, the dripped dew condensation water flows out to the outside of the surface member 21 through the drain grooves 21j, 21j, 21k, and 21k. In this way, by forming a flow path through which condensation water flows, the control board 31 can be protected from condensation. [0053] Next, the effects of the invention will be described with reference to the first embodiment and a comparative example. Fig. 8 is a schematic diagram showing the positional relationship between the operation panel and the thermal insulation box, (a) is the first embodiment, and (b) is a comparative example. [0054] The comparative example shown in FIG. 8(b) is a case where the back surface 142c of the substrate accommodating portion 141 is formed to imitate the inclined surface 12a1, and the surface 121a of the surface member 121 is formed to imitate the heat-insulating box 100 formed by the inclined surface 12a1. In the comparative example constructed in this way, the gap S100 formed between the back surface 142c of the substrate accommodating portion 141 and the vacuum insulation material 50 (surface 50s) is that the gap on the front side becomes narrower than the gap on the back side. The fluidity of the foam insulation material in the gap deteriorates. In addition, the vacuum insulation material 50 is pushed by the substrate accommodating portion 41, and problems such as leakage of the vacuum insulation material 50 occur. [0055] Here, in the first embodiment, as shown in FIG. 8(a), the back surface 42c of the substrate accommodating portion 41 and the vacuum insulation material 50 are made parallel (approximately parallel). That is, with regard to the portion protruding from the side wall 12a of the inner box 12 to the back side (the amount of jump out), the protruding amount (dimension) a1 on the front side is smaller (smaller) than the protruding amount (dimension) b1 on the back side. . Thereby, the gap S between the back surface 42c of the substrate accommodating portion 41 and the vacuum insulation material 50 (front surface 50s) becomes uniform from the back side to the front side. As a result, the dimensions of the vacuum insulation material 50 and the back surface 42c of the substrate housing portion 41 (the back surface of the operation panel 20) can be shortened. In addition, the thickness dimension of the vacuum insulation material 50 can be increased, and the insulation of the refrigerator 1A can be improved. In addition, in the first embodiment, the gap between the substrate accommodating portion 41 and the vacuum insulation material 50 can be reduced, so the thickness of the refrigerator 1A can be reduced (the distance between the side panel 11a and the side wall 12a can be shortened). By making the wall thickness of the refrigerator 1A thinner, the storage volume of the refrigerator compartment 2 can be increased. [0056] In addition, in the first embodiment, as shown in FIG. 8(a), the back surface 42c of the substrate accommodating portion 41 and the side panel 11a (outer box 11) are made parallel (approximately parallel). Thereby, the same effect as when the back surface 42c of the board|substrate housing part 41 and the vacuum heat insulating material 50 are made parallel (approximately parallel) can be acquired. [0057] In addition, in the comparative example of FIG. 8(b), if the back surface 142 of the substrate accommodating portion 141 faces the direction indicated by the dotted line L100 and the back surface 142c is approximately parallel to the vacuum insulation material 50, it becomes impossible to ensure The storage space of the control board 31. [0058] Here, in the first embodiment, as shown in FIG. 8(a), the surface member 21 is formed so that the front side protrudes from the side wall 12a (side surface) toward the inside of the library more than the back side. That is, for the protrusion from the side wall 12a of the inner box 12 to the front side, the protrusion amount (size) a2 on the front side is made larger (larger) than the protrusion amount (size) b2 on the back side. Thereby, the storage space of the control board 31 can be ensured, and it is possible to configure the back surface 42c of the board storage portion 41 and the vacuum insulation material 50 to be approximately parallel (or parallel). As a result, it is possible to reduce the size of the vacuum insulation material 50 and the back surface 42c of the substrate accommodating portion 41 (the back surface of the operation panel 20). In addition, the thickness dimension of the vacuum insulation material 50 can be increased, and the insulation of the refrigerator 1A can be improved. In addition, in the first embodiment, the gap between the substrate accommodating portion 41 and the vacuum insulation material 50 can be reduced, so the wall thickness of the refrigerator 1A can be reduced (the distance between the side panel 11a and the side wall 12a can be shortened). By making the wall thickness of the refrigerator 1A thinner, the storage volume of the refrigerator compartment 2 can be increased. In addition, on the back surface of the substrate accommodating portion 41, fins extending toward the vacuum insulation material 50 side are not provided. This can prevent the vacuum insulating material 50 from leaking due to the fin contacting the vacuum insulating material 50, and it is not necessary to make the distance between the vacuum insulating material 50 and the substrate accommodating portion 41 more than necessary in order to prevent leakage. It is particularly effective when the operation button 22 is not a touch type but a push type. [0059] In addition, in the first embodiment, a recess 21t (refer to FIG. 6) (engraved into the edge portion) is formed on the back surface of the side (front side) where the surface member 21 is protrudingly formed. Thereby, by forming the recess 21t, the edge of the back surface of the surface member 21 is formed with a flange, so the strength of the surface member 21 can be improved. In addition, the space inside the operation panel 20 can be effectively used. [0060] In addition, in the first embodiment, on the back surface of the surface member 21, the upper side portion 31b of the control board 31 extends through the side portion 31c to the lower fins (the upper fin 21e and the side fin 21f, 21g) is formed by protruding, and the upper surface of the upper rib 21e has an inclined surface portion 21e3 that descends from the back side of the surface member 21 toward the front side (refer to FIG. 7). Thereby, it is possible to prevent condensation water from flowing into the control board 31, to protect the control board 31, and to improve the reliability of the operation panel 20. [0061] In addition, in the first embodiment, the upper surface of the upper fin 21e has inclined paths 21e1,21e2 that are inclined so as to descend from the center in the width direction toward both sides in a front plan view. Thereby, water (liquid droplets) immersed from above the operation panel 20 can be guided to the side ribs 21f and 21g without accumulating on the upper fins 21e, and the control board 31 can be protected. [0062] In addition, in the first embodiment, on the back surface of the surface member 21, drainage grooves 21j, 21k are formed at the lower ends in the vertical direction. In this way, if water enters the substrate accommodating portion 41, it can be drained from the drain grooves 21j, 21k, and the reliability of the operation panel can be improved. [0063] In addition, in the first embodiment, the rib 21b is not formed at a position overlapping the drain grooves 21j, 21k in the vertical direction. Thereby, the water can be induced to the drainage ditch 21j, 21k by the rib 21b. [0064] In addition, in the first embodiment, a reinforcing portion 41s extending from the bottom surface of the substrate accommodating portion 41 toward the side of the surface member 21 is formed. Thereby, when the foamed heat insulating material is filled, the deformation of the substrate accommodating portion 41 can be prevented. [0065] However, the inclined surface 12a1 of the side wall 12a may be slightly R-shaped (convex toward the inner side of the library) in some cases. In such a case, as a countermeasure for the gap, it is preferable that the substrate housing portion 41 also has an R shape. Here, in the second embodiment and the third embodiment shown below, by making the mounting locations of the receiving portions 61, 81 of the side wall 12a flat, it is not necessary to make the substrate receiving portions 61, 81 have an R shape . [0066] (Second Embodiment) FIG. 9 is a schematic diagram showing the positional relationship between the operation panel and the thermal insulation box of the second embodiment. [0067] As shown in FIG. 9, in the refrigerator 1B of the second embodiment, a concave-shaped step portion 12m is formed on the inclined surface 12a1 of the side wall 12a. This stepped portion 12m has a quadrangular cylindrical body 12m1 extending from the opening of the side wall 12a toward the side panel 11a, and an annular portion 12m2 extending inward from the tip of the cylindrical body 12m1. The annular portion 12 m 2 is formed approximately parallel to the vacuum insulation material 50. In other words, the annular portion 12m2 is formed approximately parallel to the side panel 11a. In addition, the amount of protrusion of the stepped portion 12m from the side wall 12a to the back side is such that the amount of protrusion (size) on the front side is smaller (smaller) than the amount of protrusion (size) on the back side. [0068] The surface member 51 has a fin 52 protruding toward the back side, and the tip of the fin 52 abuts on the surface of the flange portion 12m2. [0069] The substrate accommodating portion 61 is configured to have a concave portion 62 for accommodating the control board 31, and a flange portion 63 formed on the edge of the opening of the concave portion 62. The recess 62 is formed so that the back surface 62c and the vacuum insulation material 50 are approximately parallel to each other. The flange portion 63 abuts on the ring portion 12m2. [0070] In the second embodiment, the back surface 62c of the substrate accommodating portion 61 can be approximately parallel to the vacuum insulation material 50, so the gap S1 between the back surface 62c and the vacuum insulation material 50 can be made uniform. In addition, in the surface member 51 of the second embodiment, the front side is formed to protrude from the inclined surface 12a1 of the side wall 12a to the inner side of the library more than the side surface side. Thereby, the gap between the vacuum insulation material 50 and the back surface 62c of the substrate housing portion 61 (the back surface of the operation panel 20) can be reduced. By reducing the gap in this way, the thickness dimension of the vacuum insulation material 50 can be increased, and the insulation of the refrigerator 1A can be improved. In addition, in the second embodiment, the gap between the substrate accommodating portion 61 and the vacuum insulation material 50 can be reduced, so the wall thickness of the refrigerator 1A can be reduced (the distance between the side panel 11a and the side wall 12a can be shortened). By making the wall thickness of the refrigerator 1A thinner, the storage volume of the refrigerator compartment 2 can be increased. [0071] (Third Embodiment) FIG. 10 is a schematic diagram showing the positional relationship between the operation panel and the thermal insulation box of the third embodiment. [0072] As shown in FIG. 10, in the refrigerator 1C of the third embodiment, a convex-shaped step portion 12p is formed on the inclined surface 12a1 of the side wall 12a. This stepped portion 12p has a quadrangular cylindrical body 12p1 extending from the opening of the side wall 12a toward the interior, and an annular portion 12p2 extending inward from the tip of the cylindrical body 12p1. The annular portion 12p2 is formed approximately parallel to the vacuum insulation material 50. In other words, the annular portion 12p2 is formed approximately parallel to the side panel 11a. In addition, the amount of protrusion of the stepped portion 12p from the side wall 12a to the front side is such that the amount of protrusion (size) on the front side is larger (larger) than the amount of protrusion (size) on the back side. [0073] The surface member 71 has a fin 72 protruding toward the back side, and the tip of the fin 72 abuts on the surface of the annular portion 12p2. [0074] The board accommodating portion 81 is configured to have a recess 82 for accommodating the control board 31, and a flange portion 83 formed on the edge of the opening of the recess 82. The recess 82 is formed so that the back surface 82c and the vacuum insulation material 50 are approximately parallel to each other. The flange portion 83 is in contact with the ring portion 12p2. [0075] In the third embodiment, the back surface 82c of the substrate accommodating portion 81 can be approximately parallel to the vacuum insulation material 50, so the gap S2 between the back surface 82c and the vacuum insulation material 50 can be made uniform. In addition, in the second embodiment, the surface member 71 is formed so that the front side protrudes from the side wall 12a toward the inside of the library more than the side surface side. Thereby, the same effect as the second embodiment can be obtained. [0076] Furthermore, in the second embodiment, the case where the side wall 12a has a concave shape is described, and in the third embodiment, the case where the side wall 12a has a convex shape is taken as an example for description, but it is not The concave shape or the convex shape can simply make the installation place a flat surface. [0077] However, if the gap between the substrate accommodating portion 41 (hereinafter referred to as the housing) and the outer plate (side panel 11a) is reduced, the gap between the housing and the vacuum insulation material 50 is also assumed to be in the gap. A state where urethane (foamed heat insulating material) is placed around and urethane is not placed near the center. In addition, the control board 31 is increased in size due to the multifunctional operation of the operation panel 20, and the housing for accommodating the control board 31 is also increased in size, and it becomes easy to be affected by the foaming pressure during urethane filling. The relationship between the foaming pressure and the density of the urethane becomes as shown in Fig. 11(a). That is, the density of urethane increases when the gap is reduced, so the foaming pressure becomes higher as the density of urethane increases. Therefore, defects such as damage or deformation of parts such as the case may occur. Here, in order to avoid such defects, the urethane density (ρ) satisfies the following relational formula 1, and is made into a refrigerator using urethane that satisfies the density of this formula. [0078] ρ: urethane density (kg/mm 3 ) K: shell rigidity (N/mm) A: urethane entering the back of the shell and the installation area of the shell (mm 2 ) In addition, the shell rigidity K, as shown in Figure 11 As shown in (b), in the state where all the protrusions on the outer periphery of the case and the case inside are supported, a load F is applied to it, which is obtained by (load F: N)/(deformation R: mm) Numerical value. [0079] In a structure like this embodiment, since the outer shell makes the heat insulating portion thinner, the thickness of the urethane is reduced, and the density of the urethane tends to increase. Here, in this embodiment, it is assumed that the density of urethane is 45 kg/m 3 or more. [0080] Next, the basis for formula 1 will be explained. From the relationship between density (ρ: kg/mm 3 ) and foaming pressure (P: MPa), the amount of deformation caused by foaming can be represented by the left side of the following (Formula 2) . Next, the relationship between the urethane density and the foaming pressure shows a tendency as shown in FIG. 11(a) based on the results of experiments conducted by the inventors. In addition, in order to prevent damage to parts such as the housing caused by the urethane foaming pressure, it is necessary to satisfy the relationship of (Equation 2). [0081] [Foam pressure]×[Area]/[Shell rigidity]≦[Allowable value]･･････(Equation 2) The density of ethyl ester is generally about 500×10^9kg/mm 3 . The foaming pressure (MPa) in this case is calculated from the relational expression obtained in Fig. 11(a), and the shell rigidity K is obtained by CAE analysis, and the allowable value corresponding to the right side of (Equation 2) is determined. In addition, with the diversification of operation panels in the future, the assumed size will be doubled, or due to material changes, etc., the housing rigidity K will be expected to become 1/4, and the allowable value must be about 8 times. Thus the safety rate is 8. Based on the above-explained relational expression (Equation 2) obtained in Figure 11(a), considering the allowable value of the safety rate, (Equation 1) is derived, and it becomes the conditional expression of the urethane density corresponding to the damage or deformation of the shell . [0082] When the wall thickness of the heat-insulating box 10 is made thinner, the gap between the housing and the vacuum heat-insulating material is inevitably narrowed. For example, if the gap is less than 10 mm, the urethane density is high, the foaming pressure becomes high, and it becomes easy to deform. Here, there is no urethane (foamed heat insulating material) between the outer panel (or the vacuum heat insulating material 50) and the outer panel (or the vacuum heat insulating material 50) at least in the vicinity of the center by providing the housing (the circuit board housing portion 41) accommodating the substrate (control board 31) The intermediate refrigerator can suppress the deformation caused by the foaming pressure, and can save the space required for the margin. [0083] In addition, as shown in FIG. 12, an intermediate member 90 may be provided between the housing (the substrate housing portion 41) and the vacuum insulation material 50. The intermediate member 90 is a member for suppressing or preventing the intrusion of the foamed heat insulating material, and a sponge-like material such as soft urethane or foamed polystyrene can be used. In addition, if the distance between the casing and the vacuum insulation material 50 is set to a narrow 6 mm or less, it becomes difficult for the foam insulation material to enter between the casing and the vacuum insulation material 50. [0084] In addition, by providing the intermediate member 90, the housing and the vacuum insulation material 50 are not in direct contact, so leakage of the vacuum insulation material 50 can be prevented. In addition, the intermediary member 90 may also be a compressive member that closes the gap between the casing and the vacuum insulation material 50 (the intermediary is crushed by crushing a gap larger than the original size). In addition, as the compressive member, foamed polystyrene and polyethylene foam can be applied. In addition, the intermediate member 90 is preferably one that is not immersed in the foamed heat insulating material. [0085] In addition, the present invention is not limited to the foregoing embodiments, and includes various modifications. For example, in this embodiment, the case where the operation panel 20 is provided on the inclined surface 12a1 of the side wall 12a in the library will be described, but it can also be applied to the top surface wall 12d where the lamp in the library is installed. Or it can also be applied to a place where the main board on the upper surface of the refrigerator is mounted. Or it can also be applied to places where IOT (Internet of Things) boards are mounted.