200417714 玖、發明說明： 【發明戶斤屬之技術領域3 發明領域 本發明係有關於一種去除附著於封入有可燃性冷媒之 5 冷凍循環之冷卻器之霜的除霜加熱器及該加熱器之製造方 法，該冷卻器係用於冰箱等冷卻裝置。 發明背景 習知用以去除附著於冰箱之冷凍循環之冷卻器的霜之 10 除霜加熱器係揭示於曰本專利公開公報特開平8 —54172 號。 第8圖係内藏習知之除霜加熱器15之冰箱1主要部份之 截面圖。冰箱1具有冷凍室2、冷藏室3、冷凍室之門4、冷 藏室之門5、將冷凍室2與冷藏室3分隔之分隔壁6、吸入冷 15 凍室2内之空氣之吸入口 7、吸入冷藏室3内之空氣之吸入口 8、吹出冷氣之吹出口9、蒸發器10、使冷氣循環之風扇11 及將蒸發器1 〇與冷凍室2分隔之分隔壁12。並於蒸發器10之 下方設置以玻璃管包覆呈螺旋狀之鎳鉻耐熱合金線之除霜 加熱器15、用以防止因除霜而產生之水直接滴下而接觸除 20 霜加熱器15時發出之蒸發音之頂板16及金屬製底板17。以 桶13收集之水經由排水口 14而排出。 接著，說明上述除霜加熱器15之動作。蒸發器10為流 經其中之冷媒所冷卻，而將冷；東室2及冷藏室3冷卻。風扇 11將在冷凍室2及冷藏室3升溫之空氣從吸入口 7及吸入口 8 5 200417714 ，至冷卻室(圖中未示)。該空氣 被冷卻，並藉風扇u從吹出口 9送至冷凌室2内。 、!:從冷，東室2連通至冷藏室3之口 (圖中未示)送至:: 至J 0 …在蒸發器U)進行熱交換之空氣為藉冷;東室2之門4與冷 藏至3之門5的開閉而流入之高溫外部空氣或藉存在於保存 在冷康室2及冷藏室3之食品所蒸發之水分而呈高濕度之空 氣。因此，於較該空氣低溫之蒸發器1〇中’空氣中之水分 便結霜而附著，且隨著結霜量增加’而阻礙蒸發器10與空 氣之傳…、進而’附著之霜成為通風阻礙，而使通過蒸發 器10之工氣里減少’導致熱之通過率下降，而發生冷卻不 足0 因此，在發生冷卻不足前，將除霜加熱器15之鎳鉻耐 熱合金線通電。當鎳鉻耐熱合金線一開始通電，便從鎳鉻 15耐熱合金線放射出熱射線至蒸發器及其周圍零件。此時， 放射至底板17之熱射線之一部份從底板17反射至鎳鉻耐熱 合金線，其他之部份則朝向蒸發器1〇及其周圍零件反射。 朝向蒸發器10反射之熱使附著在蒸發器1〇、桶13及排水口 14附近之霜融化成水。 20 如此產生之水一部份直接落入桶13，其他則藉頂板16 避開除霜加熱器15而落入桶13後，從排水口 14排出。 在上述習知之除霜加熱器中不僅是鎳鉻财熱合金線， 用以包含鎳鉻耐熱合金線之玻璃管表面之溫度亦是非常 高。由於底板17位在除霜加熱器15附近，且將從除霜加熱 6 200417714 器15放射出之熱射線之一部份反射至除霜加熱器15，故玻 璃管之溫度又更上升。 又，冷媒有從蒸發器10或設置於與冰箱連通之部份之 配管漏出之可能性。若冷媒為可燃性時，除霜加熱器15之 5 玻璃管之溫度須不超過冷媒之起火溫度。 【發明内容3 發明概要 一種除霜加熱器，係將附著於冷凍循環之蒸發器之霜 加熱後，將之去除者，其包含有：第1玻璃管，係於一端具 10 有開口者；加熱線，係收納於前述第1玻璃管内者；栓體， 係用以覆蓋前述第1玻璃管之前述開口，並形成有連通前述 第1玻璃管之内部與外部之第1孔者；導線，係通過前述栓 體之前述第1孔，而連接於前述加熱線者；及閥體，係設置 於前述栓體，以使前述第1玻璃管之前述内部之氣體流出至 15 外部者。 在該除霜加熱器中，玻璃管之溫度不易上升。 圖式簡單說明 第1圖係本發明實施形態之除霜加熱器之主要部份截 面圖。 20 第2圖係顯示使用實施形態之除霜加熱器之冰箱之冷 凍系統。 第3圖係實施形態之除霜加熱器之分解圖。 第4圖係顯示另一實施形態之除霜加熱器。 第5圖係顯示又另一實施形態之除霜加熱器。 7 200417714 第6圖係第5圖所示之除霜加熱器之主要部份截面圖。 第7圖係顯示再另一實施形態之除霜加熱器。 第8圖係具有習知除霜加熱器之冰箱之截面圖。 I：實施方式】 5 較佳實施例之詳細說明 第1圖係本發明第1實施形態之除霜加熱器20之主要部 份截面圖。除霜加熱器20内藏電阻線形成螺旋狀之加熱線 21。加熱線21兩端附近具有直線狀之連接端2ia。包覆加熱 線21之玻璃管23呈外徑約10.5mm且兩端開口之圓筒狀。包 10 覆玻璃管23之玻璃管24呈外徑約20mm且兩端開口之圓筒 狀。導線26以導電性襯套28為中介連接於加熱線21。矽膠 製栓體22封住玻璃管23與玻璃管24之開口端。導線26穿過 设置於栓體22之孔22a而連接於加熱線21。於栓體22設置孔 22b ’該孔22b從玻璃管23之内部空間23a或由玻璃管23與玻 15璃管24圍出之空間24a連通栓體22外部。孔22b之最小截面 積在7_1平方毫米以下。橡膠製閥體25安裝於筒27，俾將有 底之筒27之開口部27A堵塞於孔22b。閥體25係作為在預定 之壓力差下僅於一方向開閥之逆止閥。 藉於栓體22以閥體25堵塞預定之孔221^簡單構造，使栓 2〇 體22之形狀不複雜，而可降低成本。 第2圖顯示使用實施形態之除霜加熱器2〇之冰箱之冷 凍系統。於由壓縮機60、冷凝器61、減壓機構62及蒸發^ 10構成之冷凍循環封入可燃性冷媒，並使之於壓縮機、 冷凝器61、減壓機構62及蒸發器10循環。冷凍循環係用以 8 冷卻冷卻裝置，諸如設置於冰箱，以冷卻冰箱之冷卻室。 接著’說明如上構成之除霜加熱器20之動作。以藉壓 縮機60之運轉傳送之冷媒冷卻蒸發器1〇。並藉與壓縮機6〇 同時作動之風扇11，使冰箱内之空氣通過業經冷卻之蒸發 器10 ’再將與蒸發器1〇進行熱交換後之冷氣吹入冰箱内。 壓縮機60在經過預定之運轉時間後即停止。在停止之同 時，經由導線26，將加熱線21通電，而使除霜加熱器2〇發 熱。 藉加熱線21之發熱，熱射線之一部份直接透射至外 部，而其他之部份則傳至玻璃管23、玻璃管24，以使玻璃 管24之表面溫度上升至未達可燃性冷媒之起火溫度後，散 熱至外部，以安全地進行蒸發器周圍零件之除霜。 此時，玻璃管23之内部空間23a及由玻璃管23與玻璃管 24圍出之空間24a因溫度之上升而使其内之氣體膨脹。然 而’由於閥體25因膨脹之空氣而變形，且膨脹之空氣經由 孔22b從閥體25排出至外部，故空間23a與24a之壓力不致上 升，而使玻璃管23與24不致破損，且栓體22不致脫落。 之後’當停止對加熱線21之通電，再度開始冷卻時， 玻璃管23與24内部因溫度之降低而減壓。由於在除霜加熱 器20之内部保持減壓之狀態，故閥體25可阻止外部空氣流 入。因此’即使可燃性冷媒存在於除霜加熱器2〇周圍，可 燃性冷媒亦難以流入除霜加熱器20内部，因而冷媒著火之 可能性極低。 縱使可燃性冷媒流入玻璃管内部，而因加熱線21而著 200417714 火，閥體25於玻璃管内部達預定壓力以上時，便稍微開啟， 以防止壓力過度上升，但閥體25仍可阻擋火，防止火向外 部蔓延。 又，孑L22b之最小截面積為7.1平方毫米，故非常細， 5 因而火無法從其中通過。縱使閥體25脫落，由於火無法通 過孔22b，故火無法蔓延至外部。 閥體25以有底之筒27為中介安裝於栓體22。閥體25為 橡膠製，因而當直接安裝於橡膠製之栓體22時，有閥體25 之位置難以定位，而產生閥體25開啟之壓力之偏差的情 10 形。且閥體25難以直接固定於栓體22。因此，藉閥體25安 裝於以較橡膠硬之材料構成之筒27，可使開閥之壓力穩 定，且筒27可輕易地直接固定於栓體22。由於藉改變筒27 之安裝閥體25之部份的尺寸，可改變開啟閥體25之壓力， 故可依除霜加熱器22之發熱量或玻璃管23、24之内部容積 15 等設定最適合之壓力。 第3圖為除霜加熱器20之分解圖。栓體22之孔22a之直 徑D1小於導線26之直徑D2。因而，栓體22保持在繫緊導線 26之狀態，而使外部空氣或冷媒不致經由孔22a流入除霜加 熱器20内部。 20 導線26具有矽膠等柔軟之被覆層26A，因而不易與孔 22a相通。於導線26之前端安裝襯套28，然後藉使襯套28通 過孔22a，可輕易將導線26插入孔22a。 第4圖係顯示另一實施形態之除霜加熱器120。在第1 圖所示之除霜加熱器20中，玻璃管24之表面外側為外露， 10 200417714 而如第4圖所示，亦可以金屬製管50包覆玻璃管24外側。金 屬製管50成為玻璃管24之外圍而可防止水直接流入玻璃管 24 0 於第5圖顯示另一實施形態之除霜加熱器220。第1圖所 5 示之除霜加熱器20具有由玻璃管23、24構成之雙層構造， 而除霜加熱器220不具有玻璃管24，而玻璃管23則外露。因 而’只要表面溫度較可燃性冷媒之起火點低，即使只有玻 璃管23，亦可獲得同樣之效果。 第6圖為第5圖所示之除霜加熱器220之主要部份截面 10 圖。矽膠製之栓體122封住玻璃管23之開口端。導線26穿過 設置於栓體122之孔122a而連接於加熱線21。於栓體122設 置孔122b，該孔122b係由玻璃管23之内部空間23a連通栓體 122之外部。孔122b之最小截面積在7·1平方毫米以下。橡 膠製閥體25安裝於筒27,俾將有底之筒27之開口部27Α堵塞 15 住孔122b。閥體25係作為在預定之壓力差下僅於一方向開 閥之逆止閥。 第7圖顯示又另一實施形態之除霜加熱器32〇。在第6 圖所示之除霜加熱器220中，玻璃管23之表面外側為外露， 而如第7圖所示，亦可以金屬製管50包覆玻璃管23外側。金 2〇 屬製管50成為玻璃管23之外圍而可防止水直接流入玻璃管 23。 又，在第4圖及第7圖中，若將金屬製管5〇之表面塗上 黑色’來自金屬管50之輻射熱便增加，而可提高除霜加熱 器120、320之除霜性能。進而，由於可抑制除霜加熱器12〇、 11 200417714 320之表面溫度上升，故金屬製50管有助於使表面溫度在可 燃性冷媒之起火溫度以下。 又，在實施形態中，以冰箱作為使用除霜加熱器20之 機器作說明，此機器同樣地亦可使用除霜加熱器120、220、 5 320。又，此機器不限於冰箱，亦廣泛地適用於具有蒸發器 之冷卻貯藏庫，具有封入如可燃性冷媒之冷凍循環之或自 動販賣機等。 除霜加熱器係將附著於冷凍循環之蒸發器之霜加熱 後，將之去除。本發明之除霜加熱器具有收納加熱線之玻 10 璃管，且玻璃管之溫度不易上升。因而，即使冷凍循環中 之冷媒為可燃性，玻璃管不致高於冷媒之起火溫度，而無 須考慮抑制溫度之上升。 【圖式簡單說明】 第1圖係本發明實施形態之除霜加熱器之主要部份截 15 面圖。 第2圖係顯示使用實施形態之除霜加熱器之冰箱之冷 床系統。 第3圖係實施形態之除霜加熱器之分解圖。 第4圖係顯示另一實施形態之除霜加熱器。 20 第5圖係顯示又另一實施形態之除霜加熱器。 第6圖係第5圖所示之除霜加熱器之主要部份截面圖。 第7圖係顯示再另一實施形態之除霜加熱器。 第8圖係具有習知除霜加熱器之冰箱之截面圖。 12 200417714 【囷式之主要元件代表符號表】 1.. .冰箱 2.. .冷凍室 3.. .冷藏室 4…冷凍室之門 5.. .冷藏室之門 6.. .分隔壁 7"_吸入口 8.··吸入口 9.. .吹出口 10…蒸發器 11.. .風扇 12.. .分隔壁 13…桶 14.. .排水口 15.. .除霜加熱器 16.. .頂板 17…底板 20…除霜加熱器 21…加熱線 21a...連接端 22.. .栓體 22a·.·孔 22b···孔 23…玻璃管 23a...内部空間 24.. .玻璃管 24a...空間 25…閥體 26.. .導線 27·.·筒 27Α.·_開口部 28.. .襯套 50.. .金屬製管 60.. .壓縮機 61.. .冷凝器 62.. .減壓機構 120.. .除霜加熱器 122.. .栓體 122a···孔 122b·.·孔 220.. .除霜加熱器 320.. .除霜加熱器 13Nine 200417714, invention is described: [Field of the art user belongs 3 pounds invention invention invention relates to a system removing frost adhering to the enclosed coolers 5 of flammable refrigerant of the refrigeration cycle of the defrosting heater and a heater of the present a method of manufacturing, the coolant based refrigerators for cooling means. BACKGROUND OF THE INVENTION conventional cream defrosting heater 10 for removing the line attached to the cooler of the refrigeration cycle of the refrigerator is disclosed in said Patent Publication Laid-Open Publication No. 8 -54172. Fig. 8 is a sectional view of a main part of a refrigerator 1 incorporating a conventional defrosting heater 15; The refrigerator 1 has a freezing compartment 2, a refrigerating compartment 3, a door 4 of the freezing compartment, a door 5 of the refrigerating compartment 5, a partition wall 6 separating the freezing compartment 2 from the refrigerating compartment 3, and an inlet 7 for taking in the air in the cold 15 , the air within the refrigerating compartment 3 the suction inlet port 8, the cool air is blown out of the air outlet 9, the evaporator 10, the cold air circulating fan 11 and the evaporator 2 freezing chamber 1 and the square of the partition wall 12 partitioning. Below the evaporator 10, a defrosting heater 15 covered with a spiral-shaped nickel-chromium heat-resistant alloy wire with a glass tube is arranged to prevent the water generated by the defrosting from dripping directly to contact the defrosting heater 15 the sound was evaporated issued top plate 16 and bottom plate 17 made of a metal. 13 collected water to the tub through the water outlet 14 is discharged. Next, the operation of the defrosting heater 15. The evaporator 10 is cooled by the refrigerant flowing therethrough, and is cooled; the east room 2 and the refrigerating room 3 are cooled. The fan 11 from the air intake 2 and the refrigerating compartment the freezing compartment 3 and the temperature rise of the air inlet port 7 85200417714, to the cooling chamber (not shown). The air is cooled and fed by the cooling fan u Ling from the outlet chamber 92. ,:! From the cold, to the communication port 3 of the refrigerating chamber 2 East (not shown) supplied to the J 0 ... :: evaporator U) of the air heat exchanger by cooling; Mendong chamber 2 of 4 outside air temperature to the door 3 of the refrigerator with the opening and closing of 5 flows into or stored by the moisture present in the chamber 2 and the refrigerating chamber cold health food of the 3 was evaporated and the high humidity of the air. Thus, the relatively low temperature in the evaporator air 1〇 'moisture in the air will be attached frost, and the frost quantity increases as the' hinder the evaporator 10 and the air mass of ..., and thus' be attached to the ventilation Cream obstruction, reduced by the working gas in the evaporator 10 'pass rate results in decrease of heat, and insufficient cooling occurs 0 Thus, insufficient cooling occurs before the defrosting heater nichrome wire 15 of the power. When a nichrome wire start of energization, heat begins nickel-chromium alloy wire 15 to the evaporator heat ray emitted and its surrounding parts. In this case, the heat radiation to the bottom plate portion 17 of one of the rays reflected from the bottom plate 17 to the nichrome wire, the other part of the evaporator towards its surrounding parts 1〇 reflection. 10 reflecting the heat toward the evaporator melts into water adhering 1〇 evaporator, the tub 13 and the discharge port 14 near the cream. The thus produced water 20 falls directly into the tub part 13, others by the top plate 16 to avoid defrosting heater 15 falls into the tub 13, is discharged from the drain outlet 14. In the conventional defrost heater is not only the nickel-chromium alloy wire Choi heat to a temperature of the glass surface comprising the nichrome wire is also very high. Since the bottom plate 17 near the defrosting heater 15, and the defrost heater 6200417714 from the heat of the emitted radiation 15 is reflected to one part of the defrosting heater 15, so that the devitrification temperature of the glass tube rises still more. In addition, there is a possibility that the refrigerant may leak from the evaporator 10 or a pipe provided at a portion communicating with the refrigerator. If the flammable refrigerant, the temperature of the glass tube 15 of the defrosting heater 5 must not exceed the ignition temperature of the refrigerant. SUMMARY OF THE INVENTION SUMMARY OF THE INVENTION A defrosting heater 3, based adhered to the evaporator of the refrigeration cycle of cream after heating, the removal of the person, which comprises: a first glass tube, having one end tied to an opening 10 persons; heating Wire, which is stored in the first glass tube; plug body, which covers the opening of the first glass tube, and forms a first hole that communicates the inside and the outside of the first glass tube; Those connected to the heating wire through the first hole of the plug body; and the valve body is provided in the plug body so that the gas inside the first glass tube flows out to the outside. In the defrosting heater, the temperature of the glass does not easily rise. Brief Description of the drawings Fig 1 system main portion cross-sectional view of the embodiment of the present invention defrost heater. FIG 20 the second embodiment of the refrigerator display system using the defrost heater of the refrigerating system. 3 an exploded view of FIG lines form the defrost heater of the embodiment. FIG 4 shows another embodiment of the system of the defrosting heater. FIG 5 show yet another embodiment of the system of the defrosting heater. 7200417714 FIG. 6 lines shown in FIG. 5 a sectional view of the main portion of the defrost heater. FIG 7 show yet another embodiment of the system of the defrosting heater. Figure 8 a conventional system having a cross-sectional view of the refrigerator of the defrost heater. I: Embodiment 5 of the detailed description of the first line in FIG. 1 a first embodiment of the present invention defrost heater main portion sectional view of parts of the preferred embodiment 20. The defrosting heater 20 has a resistance wire formed therein to form a spiral heating wire 21. The connector has a linear heating wire near the terminal ends 21 2ia. The glass tube 23 covering the heating wire 21 has a cylindrical shape having an outer diameter of about 10.5 mm and openings at both ends. Package 10 of cover glass 23 of the glass tube 24 is about 20mm and the ends of the outer diameter of the cylindrical opening. Conductive liner conductors 26 to 28 is connected to the heating wire 21 intermediary. The silicone plug body 22 seals the open ends of the glass tube 23 and the glass tube 24. The lead wire 26 is connected to the heating wire 21 through a hole 22a provided in the plug body 22. 22 is provided in the plug hole 22b 'of the outer hole 22b from the inner space of the glass tube 23 of the plug body 23a or 24a communicate with the space 23 by the glass of the glass tube 15 encloses a glass tube of 24 22. The minimum cross-sectional area of the hole 22b is 7_1 mm2 or less. The rubber valve body 25 is attached to the cylinder 27, and the opening 27A of the bottomed cylinder 27 is closed in the hole 22b. The valve body 25 is a check valve that opens in only one direction at a predetermined pressure difference. The simple structure of the plug body 22 by blocking the predetermined hole 221 with the valve body 25 makes the shape of the plug body 20 not complicated, and the cost can be reduced. Fig. 2 shows a refrigeration system of a refrigerator using the defrosting heater 20 of the embodiment. Consisting of a compressor 60, a condenser 61, an evaporator 62 and the pressure-reducing mechanism 10 ^ 10 cycles of the refrigeration cycle constituting the flammable refrigerant is sealed, and the compressor, a condenser 61, an evaporator 62, and a pressure-reducing mechanism. The refrigeration cycle system for cooling a cooling device 8, such as is provided in the refrigerator, the refrigerator to cool the cooling chamber. Next 'the operation of the defrosting heater 20 composed of the above. The evaporator 10 is cooled by the refrigerant conveyed by the operation of the compressor 60. And by the simultaneous operation of the compressor 6〇 fan 11, the air already cooled by the refrigerator within the evaporator 10 'and then the air is cooled after the heat exchange with the evaporator 1〇 blown into the refrigerator. The compressor 60 is stopped after a predetermined time after the operation. When stopping the same, via lead 26, the heater wire 21 is energized, the defrosting heater 2〇 fever. By heating of the heater wire 21, one part of the heat ray directly transmitted to the outside, while the other part is transmitted to the glass 23, the glass tube 24, so that the surface temperature of the glass rises to less than 24 of the flammable refrigerant after ignition temperature, heat dissipation to the outside, in order to safely perform the defrosting of the evaporator surrounding parts. At this time, the internal space 23a of the glass tube 23 and the space 24a surrounded by the glass tube 23 and the glass tube 24 expand the gas therein due to the temperature rise. However, 'the valve body 25 due to the expansion of air due deformed, and the expansion of the air discharged from the valve body 25 through the hole 22b to the outside, so that the spaces 23a and 24a and the pressure will not rise, so that the glass tube 23 and 24 will not be damaged, and the pin 22 will not fall off. After that, when the energization of the heating wire 21 is stopped and cooling is started again, the inside of the glass tubes 23 and 24 is decompressed due to the decrease in temperature. Since the holding state of reduced pressure in the interior of the defrost heater 20, so that the valve body 25 can prevent the inflow of outside air. Thus', even if flammable refrigerant is present around the defrosting heater 2〇, it would be difficult flammable refrigerant flows into the defrost heater 20, the refrigerant is extremely low and therefore the possibility of fire. Even when the flammable refrigerant flows into the interior of the glass tube, the heating wire 21 by the fire 200 417 714, the valve body 25 inside the glass tube more than a predetermined pressure, slightly open, to prevent an excessive increase in pressure, the valve body 25 but can still fire barrier to prevent the fire from spreading to the outside. Further, larvae L22b the minimum cross-sectional area of 7.1 mm2, so very fine, 5 and thus the fire can not pass therethrough. Even if the valve body 25 falls off, since the fire cannot pass through the hole 22b, the fire cannot spread to the outside. In the valve body 25 of a bottomed cylinder 27 is attached to the intermediary plug 22. The valve body 25 is made of rubber, so that when the case 10 is directly attached to the shaped rubber plug 22 of, the position of the valve element 25 difficult to locate, to generate a pressure variation of the opening 25 of the valve body. And the valve element 25 is difficult to directly fixed to the plug 22. Thus, by the valve body 25 in a cylinder 27 mounted on the relatively hard rubber material, the valve opening pressure of the make stable, and cylinder 27 can be easily fixed directly to the plug body 22. Since by varying the size of the barrel 25 of the mounting portion 27 of the valve body, the valve body 25 may vary the opening pressure of, so to follow the defrosting heaters 22 heat the interior of the glass tube 23 or the like to set the most appropriate volume of 15 of pressure. The picture shows an exploded third defrost heater 20 of FIG. The diameter D1 of the hole 22a of the plug body 22 is smaller than the diameter D2 of the wire 26. Thus, plug 22 remains in the state of securing wire 26, the outside air or the refrigerant will not flow into the defroster heater 20 via the inner hole 22a. 20 and other soft silicone lead wire 26 having the coating layer 26A, and thus difficult to communicate with the hole 22a. The tip of the guidewire 26 is mounted on the bush 28 and the liner 28 by through-hole 22a, the wire 26 can be easily inserted into the hole 22a. FIG 4 shows another embodiment of the system of the defrosting heater 120. Shown in FIG. 1 of the defrost heater 20, the outer surface 24 of the glass tube is exposed, and 10200417714 as FIG. 4, 24 can also be coated with metal outer glass tube 50 shown in FIG. 50 is a metal pipe 24 of the periphery of the glass tube can be prevented from flowing directly into the glass tube 240 shows another embodiment of a defrost heater 220 in FIG. 5. The defrosting heater of FIG. 5 shows the first 120 has a double structure composed of the glass tube 23, and the defrosting heater 220 does not have a glass tube 24, and the glass tube 23 is exposed. Because of the 'fire as long as the surface temperature of the flammable refrigerant than low, even if only the glass tube 23, the same effect can be obtained. 10 main portion cross-sectional diagram showing a defrosting graph shown in FIG. 6 of the heater 220 5th. Made of silicone plug 122 is sealed open end 23 of the glass tube. The lead wire 26 is connected to the heating wire 21 through a hole 122a provided in the plug body 122. 122 provided in the plug hole 122b, the hole 122b of the inner space of the glass tube 23 by a line 23a of the outer plug 122 of the communication. The minimum cross-sectional area of the hole 122b in the 7.1 mm 2 or smaller. Rubber off to allow the valve body 25 is attached to the cylinder 27, to serve the opening of a bottomed cylindrical portion 27 of the stay 15 27Α plugging hole 122b. The valve body 25 is a check valve that opens in only one direction at a predetermined pressure difference. FIG. 7 shows yet another embodiment of the first aspect of the defrost heater 32〇. In the defrosting heater 220 shown in FIG. 6, the outer surface 23 of the glass tube is exposed, and as shown in FIG. 7, the metal pipe 50 may also cover the outside glass tube 23. Metal 2〇 metal pipe 50 becomes the periphery of the glass tube 23 is prevented from flowing directly into the glass tube 23. Further, in FIG.4 and FIG. 7, when the surface of the metal tube 5〇 black painted 'from the metal pipe 50 of the heat radiation will be increased, but it may improve the performance of defrosting the defrost heater 120,320. Further, since the defrosting heater 12〇 suppressed, 11200417714320 temperature rise of the surface, it contributes to the metal 50 surface temperature of the combustible refrigerant ignition temperature. Further, in the embodiment, in order to use the machine as a refrigerator defrost heater 20 the description is omitted, the machine can also be used similarly to the defrosting heaters 120, 220, 5320. Furthermore, this machine is not limited to the refrigerator, but also widely applicable to a cooling storage of the evaporator, the refrigeration cycle is filled with a flammable refrigerant of the automatic vending machine or the like. The defrost heater removes frost attached to the evaporator of the refrigeration cycle after heating. The present invention has a defrost heater receiving hot glass Naga the glass tube 10, and the temperature of the glass does not easily rise. Accordingly, even if the refrigeration cycle is a flammable refrigerant, higher than the glass without the ignition temperature of the refrigerant, without the need to consider suppression of the temperature rise. Brief Description of the drawings] [FIG 1 based major part of the embodiment of the present invention defrost heater sectional surface 15 in FIG. Fig. 2 shows a cooling bed system of a refrigerator using the defrosting heater of the embodiment. 3 an exploded view of FIG lines form the defrost heater of the embodiment. FIG 4 shows another embodiment of the system of the defrosting heater. 20 Fig. 5 shows a defrost heater according to still another embodiment. FIG 6 system shown in FIG. 5, a sectional view of the main portion of the defrost heater. FIG 7 show yet another embodiment of the system of the defrosting heater. Figure 8 a conventional system having a cross-sectional view of the refrigerator of the defrost heater. 12200417714 [granary symbol representing the main elements of the formula in Table 1 ..]. 2 refrigerator ... .. 3 freezing chamber door of the freezing compartment the refrigerating compartment 4 ... 5 ... .. refrigerating compartment door 6 partition wall 7 " _ · suction port 8. The intake port 9 ... .. outlet 10 of the evaporator fan 12 .. 11 .. 13 ... partition wall 14 .. tub drain defrost heater 15 .. 16...... . The top plate 17 ... bottom plate 20 ... 21 ... defrost heater heating wire connection end 21a ... 22 .. The pin body 22a ·. · hole 22b ··· hole 23a of the glass tube 23 ... 24 ... inner space. . glass body 24a ... space 25 ... 26 .. The wires 27 · · cartridge 27Α. · _ .. opening portion 28 bushing 50 ... .. the metal pipe 60 compressor 61. Condenser 62 .. Decompression mechanism 120 .. Defrost heater 122 .. Plug body 122a ... Hole 122b ... Hole 220 ... Defrost heater 320 ... Defrost heater Device 13