JPS63252379A - Electric heating unit - Google Patents
Electric heating unitInfo
- Publication number
- JPS63252379A JPS63252379A JP8600287A JP8600287A JPS63252379A JP S63252379 A JPS63252379 A JP S63252379A JP 8600287 A JP8600287 A JP 8600287A JP 8600287 A JP8600287 A JP 8600287A JP S63252379 A JPS63252379 A JP S63252379A
- Authority
- JP
- Japan
- Prior art keywords
- heating wire
- heat insulating
- insulating base
- groove
- electric heating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005485 electric heating Methods 0.000 title claims description 18
- 238000010438 heat treatment Methods 0.000 claims description 59
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 10
- 239000000835 fiber Substances 0.000 claims description 8
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- 238000004804 winding Methods 0.000 claims description 7
- 239000011810 insulating material Substances 0.000 claims description 6
- 239000000853 adhesive Substances 0.000 description 9
- 230000001070 adhesive effect Effects 0.000 description 9
- 239000000919 ceramic Substances 0.000 description 6
- 238000009413 insulation Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 238000010411 cooking Methods 0.000 description 3
- 239000012774 insulation material Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000005524 ceramic coating Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000007666 vacuum forming Methods 0.000 description 1
Landscapes
- Resistance Heating (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、一般家庭において主に調理用に使用される電
熱ユニットに関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric heating unit used mainly for cooking in ordinary households.
従来の技術
従来より、一般家庭で使用される調理用の電熱ユニット
としては、陶器の上に、螺旋状に巻いた電熱線を配設し
た電気こんろや、シーズヒータを渦巻状に巻いてユニッ
ト化した電気レンジなどがある。Conventional technology Traditionally, electric heating units for cooking used in general households include electric stoves with spirally wound heating wires placed on ceramics, and units with sheathed heaters wound in a spiral pattern. There are modern electric ranges.
これら以外に、欧米では、螺旋状に巻いた電熱線を断熱
材に設けた溝に配設し、この上にセラミックガラス板を
置き、そしてこのセラミックガラス板を加熱面とするス
ムーズトップと呼ばれる電熱ユニットなどが広く使用さ
れている。In addition to these methods, in Europe and the United States, there is an electric heating system called smooth top, in which a spirally wound heating wire is placed in a groove in the insulation material, a ceramic glass plate is placed on top of the heating wire, and the ceramic glass plate is used as the heating surface. units are widely used.
しかしながら、日本においては、陶器を使用した電気こ
んろが価格的に安価であるとともに、スムーズトップな
どの電熱ユニットなどに比較して、熱効率が優れている
ため、いまだ根強い需要がある。However, in Japan, electric stoves made of ceramic are still in strong demand because they are inexpensive and have superior thermal efficiency compared to electric heating units such as smooth tops.
ところが、昔ながらの陶器を使用した電気こんろは、電
熱線が外部に直接露出しているため、危険であったり、
調理物の内容物が吹きこぼれて電熱線の断線寿命を著し
く短かくするなどいろいろな欠点があった。However, electric stoves that use traditional ceramics can be dangerous because the heating wires are directly exposed to the outside.
There were various drawbacks, such as the contents of the cooking material boiling over and significantly shortening the lifespan of the heating wire.
さらに、陶器の熱容量が大きいため、重量的に重いとと
もに、なかなか冷めにくく、したがって使用後、すぐに
移動させたり、あるいは収納することができず、使い勝
手の面においても欠点があった。Furthermore, since ceramics have a large heat capacity, they are heavy and difficult to cool down, so they cannot be moved or stored immediately after use, and are also disadvantageous in terms of usability.
このため、本発明者らは、すでに金属板からなる天板と
、螺旋状に巻かれた電熱線と、この電熱線を蛇行状に配
設する溝を有し、かつシリカまたはアルミナ繊維を主成
分とする断熱材からなる断熱基盤と、この断熱基盤を収
納する金属板製の収納ケースとを備え、前記天板の被加
熱物側に放射層を形成し、かつ電熱線側に絶縁層を形成
した電熱ユニットを提案している。For this reason, the present inventors have already provided a top plate made of a metal plate, a spirally wound heating wire, and a groove in which the heating wire is arranged in a meandering manner, and which is mainly made of silica or alumina fiber. A heat insulating base made of a heat insulating material as a component and a storage case made of a metal plate for storing the heat insulating base, a radiation layer is formed on the side of the object to be heated of the top plate, and an insulating layer is formed on the side of the heating wire. We are proposing an electric heating unit made of aluminum.
発明が解決しようとする問題点
一般に、従来の電熱ユニットでは、電熱線と断熱基盤と
は、シリカゾルを主たる結合材とする接着剤で固定され
ている。これは、比較的容易にできるからである。Problems to be Solved by the Invention Generally, in conventional electric heating units, the heating wire and the heat insulating base are fixed with an adhesive whose main binding material is silica sol. This is because it is relatively easy to do.
しかし女から、この方法では、使用する接着剤が湿気に
対して弱いため、接着強度が低下したり、まだ、湿気を
吸湿して、天板または収納ケースと電熱線との電気特性
が著しく低下するなどいろいろな問題があり、したがっ
て多湿雰囲気中に放置されでも安全性に優れた電熱線の
固定方法がＴ１れていた。However, a woman told me that with this method, the adhesive used is weak against moisture, so the adhesive strength may decrease, and the electrical properties between the top plate or storage case and the heating wire may deteriorate significantly due to the absorption of moisture. There are various problems such as the following: Therefore, there has been no method of fixing heating wires that is highly safe even when left in a humid atmosphere.
本発明はこのような問題点を解決するもので、多湿雰囲
気中に放置されても安全性に優れた電熱ユニットを提供
することを目的とするものである。The present invention solves these problems and aims to provide an electric heating unit that is highly safe even when left in a humid atmosphere.
問題点を解決するだめの手段
上記問題点を解決するために本発明は、金属板からなる
天板と、螺旋状に巻かれた電熱線と、この電熱線を渦巻
状に配設する溝を有し、かつシリカ−アルミナ繊維を主
成分とする断熱材からなる断熱基盤と、この断熱基盤を
収納する金属板製の収納ケースとを備え、前記断熱基盤
の溝幅を数カ所にわたって部分的に電熱線の巻径より小
さく成型し、この部分に電熱線を押し込むことにより電
熱線を固定したものである。Means for Solving the Problems In order to solve the above problems, the present invention includes a top plate made of a metal plate, a spirally wound heating wire, and a groove in which the heating wire is arranged in a spiral shape. and a heat insulating base made of a heat insulating material mainly composed of silica-alumina fibers, and a storage case made of a metal plate that houses the heat insulating base, and the groove width of the heat insulating base is partially electrically connected at several locations. The heating wire is fixed by molding it to a diameter smaller than the winding diameter of the heating wire and pushing the heating wire into this part.
作用
従来より、電熱線を固定する接着剤として、電熱線と高
温で反応しに≧いシリカゾルを主たる結合材とし、これ
に断熱材の主成分であるシリカ−アルミナ繊維を加えた
ものが使用されていた。しかし、この接着剤は、高温で
の電気特性は比較的優れているものの、多湿雰囲気中に
放置されると容易に湿気を吸い、電気特性を著しく低下
させるという問題があった。Function Traditionally, adhesives used to fix heating wires include silica sol, which does not react with heating wires at high temperatures, as the main binder, and silica-alumina fibers, which are the main component of insulation materials, added to this. was. However, although this adhesive has relatively excellent electrical properties at high temperatures, it has the problem that when left in a humid atmosphere, it easily absorbs moisture and significantly deteriorates its electrical properties.
これに対し、断熱基盤に形成した溝に、電熱線の巻径よ
り小さな溝幅を有する部分を設け、この部分に電熱線を
押し込むことにより電熱線を固定する本発明においては
、接着剤をまったく使用していないため、断熱基盤その
ものに耐湿特性を具備させておけば、多湿雰囲気中に放
置されても、電気特性が低下することはない。On the other hand, in the present invention, in which the heating wire is fixed by providing a groove formed in the heat insulating base with a part having a groove width smaller than the winding diameter of the heating wire and pushing the heating wire into this part, no adhesive is used. Since it is not in use, if the heat insulating base itself has moisture-resistant properties, its electrical properties will not deteriorate even if it is left in a humid atmosphere.
また本発明においては、上記効果以外に、高温での電熱
線と接着剤との反応も考慮する必要がないため、電熱線
の長寿命化においても効果がある。In addition to the above-mentioned effects, the present invention is also effective in extending the life of the heating wire, since there is no need to consider the reaction between the heating wire and the adhesive at high temperatures.
さらに、断熱基盤と電熱線との固定にかかる工数も削減
できるため、大幅なコストダウンが可能となる。Furthermore, the number of man-hours required for fixing the heat insulating base to the heating wire can be reduced, making it possible to significantly reduce costs.
なお、本発明において、電熱線を固定する目的だけでは
、溝全体にわたってその溝幅を電熱線の巻径より小さく
成型する方が強度は増すが、電熱ユニットの立ち上がり
が非常に遅くなる。そのため、電熱線を固定する部分は
、極力少なくした方がよい。また、断熱基盤そのものに
耐湿特性を具備させるためには、シリカ−アルミナ繊維
を主成分とする断熱材の結合材として、アルミナゾルを
使用したものを使用すればよい。In the present invention, for the sole purpose of fixing the heating wire, forming the groove width over the entire groove to be smaller than the winding diameter of the heating wire increases the strength, but the heating unit starts up very slowly. Therefore, it is better to minimize the area where the heating wire is fixed. Further, in order to provide moisture resistance to the heat insulating base itself, alumina sol may be used as a binding material for a heat insulating material mainly composed of silica-alumina fibers.
このように、断熱基盤の溝に、電熱線の巻径より小さな
溝幅を有する部分を設け、この部分に電熱線を押し込ん
で電熱線を固定することにより、多湿雰囲気中に放置さ
れても電気特性の低下や電熱線の固定強度の低下が生じ
るということはなく、安全性に優れた電熱ユニットを得
ることが可能となる。In this way, by providing a groove in the insulation board with a groove width smaller than the winding diameter of the heating wire and fixing the heating wire by pushing the heating wire into this portion, the heating wire can be fixed even if left in a humid atmosphere. There is no deterioration in the characteristics or the fixing strength of the heating wire, and it is possible to obtain an electric heating unit with excellent safety.
実施例
以下、本発明の具体的な実施例を第１図〜第２図にもと
づいて説明する。図において、１は５ｐｃｃからなる天
板で、この天板１の両面には、熱の吸収および放射に優
れたセラミックコーティングにより被覆処理が施されて
いる。２はシリカ−アルミナ繊維を主成分とし、主たる
結合材としてアルミナゾルを用い、真空成型された後、
８００℃で熱処理された断熱材からなる断熱基盤で、こ
の断熱基盤２には渦巻状の溝２ａが設けられている。ま
た、この溝２ａには、数カ所にわたって溝幅の狭い部分
２ｂが形成されている。３は螺旋状に巻かれた電熱線で
、この電熱線３は断熱基盤２に設けた溝２２Ｌに配設さ
れ、そして電熱線３の巻径より小さく成型された部分２
ｂに押し込むことにより断熱基盤２に固定されている。EXAMPLES Hereinafter, specific examples of the present invention will be described based on FIGS. 1 and 2. In the figure, reference numeral 1 denotes a top plate made of 5 pcc, and both sides of the top plate 1 are coated with a ceramic coating that is excellent in heat absorption and radiation. 2 has silica-alumina fiber as the main component, uses alumina sol as the main binding material, and after vacuum forming,
The heat insulating base 2 is made of a heat insulating material heat-treated at 800°C, and the heat insulating base 2 is provided with a spiral groove 2a. Furthermore, narrow groove portions 2b are formed in several locations in the groove 2a. 3 is a spirally wound heating wire, this heating wire 3 is disposed in a groove 22L provided in the heat insulating base 2, and a portion 2 formed smaller than the winding diameter of the heating wire 3 is provided.
It is fixed to the heat insulating base 2 by pushing it into b.
４は電熱線３を配設した断熱基盤２を収納するとともに
、ステンレス鋼（ＳＵＳ４３０）Ｋ、ｔＪ構成された収
納ケースで、この収納ケース４は、天板１の内径より小
さな外径を有し、かつ天板１の内側に位置させている。Reference numeral 4 denotes a storage case that houses the heat insulating base 2 on which the heating wire 3 is arranged and is made of stainless steel (SUS430) K, tJ, and this storage case 4 has an outer diameter smaller than the inner diameter of the top plate 1. , and is located inside the top plate 1.
また、天板１と断熱基盤２とは若干の空隙をもたせた状
態で一体化されている。６は絶縁碍子であり、また６は
電気取り出し端子であり、これらは収納ケース４の下側
に設けられている。Further, the top plate 1 and the heat insulating base 2 are integrated with a slight gap. 6 is an insulator, and 6 is an electrical outlet terminal, which are provided on the lower side of the storage case 4.
このような構成を有する本発明の電熱ユニットおよび電
熱線３が配設される断熱基盤２の溝２＆の幅を電熱線３
の巻径より大きくし、そしてシリカゾルを主たる結合材
とし、これに断熱材の主成分であるシリカ−アルミナ繊
維を加えた接着剤で電熱線３を断熱基盤２の溝２１Ｌに
部分的に固定した従来の電熱ユニットについて、耐湿特
性について評価するため、これらを４０’Ｃで相対湿度
９６係の多湿雰囲気中に１週間投入し、そしてこの後の
絶縁抵抗および耐電圧を測定してみた。The width of the groove 2& of the heat insulating base 2 on which the heating wire 3 and the heating wire 3 of the present invention having such a configuration are arranged is determined by the width of the heating wire 3.
The heating wire 3 was partially fixed in the groove 21L of the insulation base 2 using an adhesive made of silica sol as the main binding material and silica-alumina fibers, which are the main components of the insulation material, added thereto. In order to evaluate the moisture resistance properties of conventional electric heating units, they were placed in a humid atmosphere at 40'C and a relative humidity of 96% for one week, and the insulation resistance and withstand voltage were then measured.
なお、これらの電気特性は、収納ケース４と、電気取り
出し端子６との間で測定した。Note that these electrical characteristics were measured between the storage case 4 and the electrical outlet terminal 6.
これらの測定結果を次表に示した。The results of these measurements are shown in the table below.
表
表から明らかなように、接着剤により電熱線３を固定し
た従来の電熱ユニットでは、絶縁抵抗が０．５ ＭΩ、
耐電圧が１２００Ｖであるという具合に、実際の使用上
においては、問題があった。As is clear from the table, in the conventional electric heating unit in which the heating wire 3 is fixed with adhesive, the insulation resistance is 0.5 MΩ,
There were problems in actual use, such as a withstand voltage of 1200V.
これに対し、本発明の電熱ユニットでは、絶縁抵抗が１
２ＭΩ、耐電圧が２４００Ｖであるという具合に非常に
高いレベルを示した。In contrast, in the electric heating unit of the present invention, the insulation resistance is 1
It exhibited a very high level of resistance of 2MΩ and withstand voltage of 2400V.
このように、溝幅を数カ所にわたって部分的に電熱線３
の巻径より小さく成型し、この部分２ｂに電熱線３を押
し込んで固定することにより、多湿雰囲気中に投入され
ても電気特性に優れた電熱ユニットが得られる。In this way, the heating wire 3 is partially spread over several parts of the groove width.
By molding the heating wire 3 into a smaller diameter than the winding diameter of the heating wire 3 and pushing and fixing the heating wire 3 into this portion 2b, an electric heating unit having excellent electrical characteristics even when placed in a humid atmosphere can be obtained.
まだ、本発明の電熱ユニットを多湿雰囲気中に１週間投
入した後の電熱線３の固定度合を評価するため、落下試
験および振動試験を行なったところ、特に異常は見られ
なかった。However, in order to evaluate the degree of fixation of the heating wire 3 after the electric heating unit of the present invention was placed in a humid atmosphere for one week, a drop test and a vibration test were conducted, and no particular abnormality was observed.
発明の効果
以上の説明から明らかなように本発明によれば、金属板
からなる天板と、螺旋状に巻かれた電熱線と、この電熱
線を渦巻状に配設する溝を有し、かつシリカ−アルミナ
繊維を主成分とする断熱材からなる断熱基盤と、この断
熱基盤を収納する金属板製の収納ケースとを備え、前記
断熱基盤の溝幅を数カ所にわたって部分的に電熱線の巻
径より小さく成型し、この部分に電熱線を押し込むこと
により電熱線を固定するようにしているため、多湿雰囲
気中に放置されても安全性に優れた電熱ユニットを提供
することができるものである。Effects of the Invention As is clear from the above description, the present invention has a top plate made of a metal plate, a spirally wound heating wire, and a groove in which the heating wire is arranged in a spiral shape. and a heat insulating base made of a heat insulating material mainly composed of silica-alumina fibers, and a storage case made of a metal plate for storing the heat insulating base, and a heating wire is partially wound around the groove width of the heat insulating base at several places. Since the heating wire is molded smaller than the diameter and the heating wire is fixed by pushing it into this part, it is possible to provide an electric heating unit with excellent safety even when left in a humid atmosphere. .
第１図は本発明の一実施例を示す電熱ユニットの断面図
、第２図は同電熱ユニットにおける断熱基盤の上面図で
ある。
１・・・・・・天板、２・・・・・・断熱基盤、２＆・
旧・・溝、２ｂ・・・・・・溝幅の狭い部分、３・・・
・・・電熱線、４・・・・・・収納ケース。FIG. 1 is a sectional view of an electric heating unit showing an embodiment of the present invention, and FIG. 2 is a top view of a heat insulating base in the electric heating unit. 1...Top plate, 2...Insulation base, 2&...
Old...Groove, 2b...Narrow groove width, 3...
...Heating wire, 4...Storage case.
Claims (1)
の電熱線を渦巻状に配設する溝を有し、かつシリカ−ア
ルミナ繊維を主成分とする断熱材からなる断熱基盤と、
この断熱基盤を収納する金属板製の収納ケースとを備え
、前記断熱基盤の溝幅を数カ所にわたって部分的に電熱
線の巻径より小さく成型し、この部分に電熱線を押し込
むことにより電熱線を固定した電熱ユニット。A heat insulating base comprising a top plate made of a metal plate, a spirally wound heating wire, a groove for arranging the heating wire in a spiral shape, and a heat insulating material mainly composed of silica-alumina fibers. ,
A storage case made of a metal plate that stores the heat insulating base, the width of the groove in the heat insulating base is partially formed to be smaller than the winding diameter of the heating wire in several places, and the heating wire is heated by pushing the heating wire into these parts. Fixed electric heating unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8600287A JPS63252379A (en) | 1987-04-08 | 1987-04-08 | Electric heating unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8600287A JPS63252379A (en) | 1987-04-08 | 1987-04-08 | Electric heating unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63252379A true JPS63252379A (en) | 1988-10-19 |
Family
ID=13874461
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8600287A Pending JPS63252379A (en) | 1987-04-08 | 1987-04-08 | Electric heating unit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63252379A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5229454A (en) * | 1975-09-01 | 1977-03-05 | Asao Kotani | Method to manufacture doubled pipes |
| JPS5311645B2 (en) * | 1971-12-28 | 1978-04-24 | ||
| JPS5367577A (en) * | 1976-09-30 | 1978-06-16 | Micropore International Ltd | Electric heater unit |
| JPS5826485A (en) * | 1981-07-24 | 1983-02-16 | エ−・ゲ−・オ−・エレクトロ−ゲレ−テ・ブランク・ウント・フイツシエル | Electric heater for heating plate and method of producing same |
-
1987
- 1987-04-08 JP JP8600287A patent/JPS63252379A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5311645B2 (en) * | 1971-12-28 | 1978-04-24 | ||
| JPS5229454A (en) * | 1975-09-01 | 1977-03-05 | Asao Kotani | Method to manufacture doubled pipes |
| JPS5367577A (en) * | 1976-09-30 | 1978-06-16 | Micropore International Ltd | Electric heater unit |
| JPS5826485A (en) * | 1981-07-24 | 1983-02-16 | エ−・ゲ−・オ−・エレクトロ−ゲレ−テ・ブランク・ウント・フイツシエル | Electric heater for heating plate and method of producing same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1077118A (en) | Glass plate surface heating unit with sheathed heater | |
| US4243874A (en) | Radiant heating unit | |
| JPH05326121A (en) | Electric heating body, especially, radiation heating body | |
| JPS63252379A (en) | Electric heating unit | |
| JPS6059689A (en) | Heater | |
| JPS6376294A (en) | Electric heating unit | |
| JPS63121289A (en) | Electric heating unit | |
| JPS63178477A (en) | Electric heating unit | |
| JPS6369184A (en) | Electric heating unit | |
| JPS63133483A (en) | Electric heating unit | |
| JPH02239585A (en) | Electric heater unit | |
| JPS6369185A (en) | Electric heating unit | |
| JPS63178478A (en) | Electric heating unit | |
| JPS63121287A (en) | Electric heating unit | |
| JPS63121291A (en) | Electric heating unit | |
| JPS63143779A (en) | Electric heating unit | |
| JPH02139888A (en) | Electric heating unit | |
| JPS63228588A (en) | Electric heating unit | |
| JPS63121288A (en) | Manufacture of electric heating unit | |
| JPH0261980A (en) | Electric heating unit | |
| JPS63133482A (en) | Electric heating unit | |
| JPS63178479A (en) | Electric heating unit | |
| JPS6326986A (en) | Electric heating unit | |
| JPS6369188A (en) | Electric heating unit | |
| JPS63121290A (en) | Electric heating unit |