JP3575414B2

JP3575414B2 - Electric water heater

Info

Publication number: JP3575414B2
Application number: JP2000290385A
Authority: JP
Inventors: 和範武智
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2000-09-25
Filing date: 2000-09-25
Publication date: 2004-10-13
Anticipated expiration: 2020-09-25
Also published as: JP2002095590A

Description

【０００１】
【発明の属する技術分野】
本発明は充電部を備えた水を収容する容器を本体の裏板側から固定する電気湯沸かし器の電気的絶縁に関するものである。
【０００２】
【従来の技術】
近年、この種の電気湯沸かし器などで裏板が導電性の材料で形成されたものは、充電部を備えた容器と裏板とを電気的に切り離すため特願平０９−２８０１２８号公報に示されているような構造が一般的になってきた。図９および図１０にその構造を示す。すなわち、１は上方を開口した水を入れる容器で、容器１の底にはヒーター２が密着して取り付けられている。３は容器１の下部を覆う樹脂製の本体の下枠で、下枠３の底面には電気部品取付用の開口部４が設けられ、開口部４は通常は金属製の裏板５で覆われている。下枠３には中央に貫通孔６を備えた凹部７が設けられ、容器１は凹部７側から貫通孔６を通したねじ８を容器１に取り付けられた容器支持板１１に締め付けることによって下枠３に固定される。容器支持板１１は金属などの導電性の材料で形成され容器１と電気的につながっている。ねじ８の頭は、電気湯沸かし器に通電して容器１や下枠３の温度が上がった時に座屈しにくいように大きくしてある。９は裏板５を下枠３に固定する裏板固定ねじで、裏板５は容器１と電気的に切り離されて取り付けられている。１０はヒーター２と電源とを接続する本体内の配線である。
【０００３】
次に、前記従来例の電気湯沸かし器における電気的な絶縁について説明する。容器１を固定しているねじ８は凹部７内に沈み込ませ裏板５で覆っているため、容器１内のヒーター２の電気絶縁が破壊されても電気的につながったねじ８に触れることはない。さらに裏板５は単独で樹脂製の下枠３に固定してあるため、容器１と絶縁されている。
【０００４】
【発明が解決しようとする課題】
しかしながら、前記従来の構成の電気湯沸かし器を、ＩＥＣ規格などを採用している国に輸出する場合には配線１０が金属製の裏板５に触れないようにしなければならず、絶縁構成や部品を日本国内向けとは変える必要があった。また、配線１０が裏板５に触れる場合には裏板５はアース接続する必要があり、下枠３を日本国内向けと輸出向けとで使い分けなければならないといった課題も有していた。
【０００５】
本発明はこのような従来の課題を解決するものであり、簡単な変更で日本国内向けと輸出向けの両方に対応できるようにすることを目的としている。
【０００６】
【課題を解決するための手段】
前記従来課題を解決するために本発明は、導電性の裏板と絶縁性の下枠に設けた孔を貫通して前記裏板と水を収容する充電部を備えた容器を固定する導電性のねじとを備え、前記下枠のねじが貫通する部分には裏板側から見て凹部を形成し、この凹部の深さとほぼ同じ高さのスペーサを端面が前記凹部の底と裏板の裏面に当接するように凹部に挿入して前記スペーサを介して前記裏板を固定したものある。
【０００７】
これにより、電気湯沸かし器をたとえば輸出向けとする場合には導電性のねじを裏板と下枠を貫通させて容器に締め付ければ、ねじを介して裏板と容器を電気的に接続することができる。この時、凹部に凹部の深さとほぼ同じ高さのスペーサを挿入してあるので、ねじを締め付けても裏板が変形してしまうことがない。
【０００８】
また、電気湯沸かし器を日本向けとする場合には従来と同様にスペーサを使用せずに容器と下枠を固定するねじと、裏板と下枠を固定するねじを別にすればよい。
【０００９】
【発明の実施の形態】
本発明の請求項１記載の発明は、底面を開口した電気絶縁性の電気湯沸かし器本体の下枠と、前記下枠の下面の開口部を覆う導電性の裏板と、充電部を備えた水を収容する容器と、前記裏板と前記下枠に設けた孔を貫通して前記裏板と前記容器を固定するねじとを備え、前記下枠はねじが貫通する部分には前記裏板側から見て凹部を設け、前記凹部内に前記凹部の深さとほぼ同じ高さのスペーサを前記凹部の底と前記裏板の裏面に当接するように挿入して前記スペーサを介して前記裏板を固定したものである。電気湯沸かし器を輸出向けとする場合には導電性のねじを裏板と下枠を貫通させて容器に締め付ければ、ねじを介して裏板と容器を電気的に接続することができる。この時、凹部に凹部の深さとほぼ同じ高さのスペーサを挿入してあるので、ねじを締め付けても裏板が変形してしまうことがない。
【００１０】
さらに、凹部は円形ないし正形でスペーサは筒状とし、前記スペーサの内径に前記スペーサの片側の板厚を加えた寸法を凹部の半径または一辺の２分の１と裏板の取付孔の半径を加えた寸法以上にしたもので、ねじを裏板側から締め付ける時にスペーサが凹部の中で片側に寄っても前記スペーサ端面が裏板の孔を塞いでしまうことがなく、組み立てが容易となる。
【００１１】
本発明の請求項２記載の発明は、底面を開口した電気絶縁性の電気湯沸かし器本体の下枠と、前記下枠の下面の開口部を覆う導電性の裏板と、充電部を備えた水を収容する容器と、前記裏板と前記下枠に設けた孔を貫通して前記裏板と前記容器を固定するねじとを備え、前記下枠はねじが貫通する部分には前記裏板側から見て凹部を設け、前記凹部内に前記凹部の深さとほぼ同じ高さのスペーサを前記凹部の底と前記裏板の裏面に当接するように挿入して前記スペーサを介して前記裏板を固定したものである。電気湯沸かし器を輸出向けとする場合には導電性のねじを裏板と下枠を貫通させて容器に締め付ければ、ねじを介して裏板と容器を電気的に接続することができる。この時、凹部に凹部の深さとほぼ同じ高さのスペーサを挿入してあるので、ねじを締め付けても裏板が変形してしまうことがない。さらに、凹部は円形ないし正方形でスペーサは筒状とし、前記スペーサの内径に前記スペーサの片側の板厚を加えた寸法を前記凹部の半径または一辺の２分の１と裏板を取り付けるねじ頭の半径を加えた寸法以下にしたもので、スペーサが凹部の中で片側に寄ってもスペーサ端面がねじの頭平面部の下に必ずかかり、ねじを締め付けた時に裏板が変形するのを確実に防ぐことができる。
【００１２】
【実施例】
以下本発明の実施例について図面を参照して説明する。
【００１３】
（実施例１）
図１は実施例１の電気湯沸かし器の下部の要部断面を示す図、図２は同電気湯沸かし器の要部拡大断面を示す図、図３は同電気湯沸かし器の下面を示す図である。図１から図３において、２１は上方を開口した水を入れる容器で、容器２１の底にはヒーター２２が密着して取り付けられている。２３は容器２１の下部を覆う樹脂製の本体下枠で、下枠２３の底面には開口部２４が設けられ、開口部２４は金属製の裏板２５で覆われている。下枠２３には図３に示すように中央上下に貫通孔２６を備えた凹部２７が設けられ、凹部２７には凹部２７の深さとほぼ同じ高さのスペーサ２８が挿入されている。筒状のスペーサ２８の内径はねじ３０の頭（寸法ｄ）にかかるように設定してある。容器２１は裏板２５の孔２９、スペーサ２８、凹部２７の貫通孔２６を通した金属製のねじ３０を容器２１に取り付けられた容器支持板３３に締め付けることによって下枠２３に固定される。容器支持板３３は金属などの導電性の材料で形成され容器２１と電気的につながっている。３１はヒーター２２と電源とを接続する本体内の配線、３２は容器２１に接続されたアース線である。
【００１４】
次に、前述した電気湯沸かし器の作用について説明する。容器２１を固定する時に、金属製のねじ３０を裏板２５の孔２９、スペーサ２８、凹部２７の貫通孔２６を通して容器支持板３３に締め付けているため、裏板２５は電気的に容器２１と接続されたことになる。すると、容器２１にはアース線３２が接続されているため、金属で電気的につながった裏板２５もアースされたことになり、配線３１が裏板２５に触れても問題なく、ＩＥＣ規格などを採用している国にも輸出することができる。
【００１５】
また、凹部２７には凹部２７の深さとほぼ同じ高さのスペーサ２８を挿入してあるので、ねじ３０を締め付けても裏板２５が支えられ変形してしまうことがない。
【００１６】
さらに、電気湯沸かし器を日本向けとする場合には従来と同様に容器２１と下枠２３を固定するねじと、裏板２５と下枠２３を固定するねじを別にすればよく、スペーサ２８とねじの使い分けで輸出向けと日本向けとを組み立てることができる。
【００１７】
なお、図ではスペーサ２８を筒状としているが、スペーサ２８は凹部の深さとほぼ同じ高さで、ねじ３０を通すことができるものであればよい。
【００１８】
（実施例２）
図４は実施例２を示す電気湯沸かし器の下枠の凹部平面とスペーサ断面を示す図である。図４では、スペーサ２８の内径にスペーサ２８の片側の板厚を加えた寸法ａを凹部２７の半径ｂと裏板２５の孔２６の半径ｃを加えた寸法以上にしたもので、ねじ３０を裏板２５側から締め付ける時にスペーサ２８が凹部２７の中で端に寄ってもスペーサ２８の内径が裏板２５の孔２９を越えているため、スペーサ２８の端面が裏板２５の孔２９を塞いでしまうことがない。
【００１９】
従って、スペーサ２８を凹部２７に入れても組み立てに支障をきたすことがなく、組み立てが容易となる。
【００２０】
（実施例３）
図５は実施例３の電気湯沸かし器の要部断面を示す図である。図５では、スペーサ２８の内径にスペーサ２８の片側の板厚を加えた寸法ａを凹部２７の半径ｂとねじ３０の頭の半径ｄを加えた寸法以下にしたもので、スペーサ２８が凹部２７の中で片側に寄ってもスペーサ２８端面がねじ３０の頭の平面の下に必ずあり、ねじ３０を締め付けた時に裏板２５が変形するのを確実に防ぐことができる。
【００２１】
（参考例１）
図６は参考例１の電気湯沸かし器の要部断面を示す図である。図６では、スペーサ２８の外径を凹部２７の深さよりも大きくしたもので、組み立てる時にスペーサ２８が凹部２７の中で横向きに倒れると、スペーサ２８が凹部２７から飛び出す。すると、裏板２５がスペーサ２８に乗り上げて浮き上がり、スペーサ２８の倒れていることが容易にわかる。
【００２２】
（参考例２）
図７は参考例２の電気湯沸かし器の下枠凹部とスペーサの断面を示す図である。図７では、凹部２７の直径をスペーサ２８が横向きに挿入された時に入らない寸法としたもので、組み立てる時に誤ってスペーサ２８を横向きに凹部２７に落としても凹部２７に入らないためすぐに取り出すことができ、便利である。
【００２３】
（参考例３）
図８は参考例３の電気湯沸かし器の下枠凹部の要部平面を示す図である。図８では、スペーサ端面２８ａと凹部２７の底が圧接される力を、下枠２３を形成する材料の使用温度における熱変形応力を越えないようスペーサ端面２８ａの面積を大きくしてある。また、スペーサ２８は金属などの耐熱性材料で形成してあり、電気湯沸かし器に通電して容器２１や下枠２３の温度が上がった時にスペーサ２８が下枠２３にくい込んだりスペーサ２８自体が熱で変形したりすることがない。スペーサ２８の板厚が薄い場合にはフランジを設けるなどしてスペーサ端面２８ａの面積を大きくしてもよい。
【００２４】
【発明の効果】
以上のように、本発明によれば、裏板と下枠に設けた孔を貫通して裏板と容器を固定する導電性のねじとを備え、下枠のねじが貫通する部分を裏板側から見て凹部を設け、この凹部の深さとほぼ同じ高さのスペーサをスペーサ端面が凹部の底と裏板に当接するようにして凹部に挿入したもので、金属製の裏板のアース接続を要求される場合には導電性のねじを裏板と下枠を貫通させて容器支持板に締め付ければ、ねじを介して裏板と容器を電気的に接続することができる。この時、凹部に凹部の深さとほぼ同じ高さのスペーサを挿入してあるので、ねじを締め付けても裏板が変形してしまうことがない。
【図面の簡単な説明】
【図１】本発明の実施例１を示す電気湯沸かし器の下部の要部断面図
【図２】同電気湯沸かし器の要部拡大断面図
【図３】同電気湯沸かし器の下面図
【図４】本発明の実施例２を示す電気湯沸かし器の下部の凹部平面とスペーサの断面図
【図５】本発明の実施例３を示す電気湯沸かし器の要部断面図
【図６】本発明の参考例１を示す電気湯沸かし器の要部断面図
【図７】本発明の参考例２を示す電気湯沸かし器の下部の凹部とスペーサの断面図
【図８】本発明の参考例３を示す電気湯沸かし器の下部の凹部平面図
【図９】従来例を示す電気湯沸かし器の要部断面図
【図１０】同電気湯沸かし器の要部拡大断面図
【符号の説明】
２１容器
２３下枠
２４開口部
２５裏板
２６貫通孔
２７凹部
２８スペーサ
２８ａスペーサ端面
２９孔
３０ねじ[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to electrical insulation of an electric water heater for fixing a water-containing container provided with a charging section from a back plate side of a main body.
[0002]
[Prior art]
In recent years, an electric water heater of this type, whose back plate is formed of a conductive material, is disclosed in Japanese Patent Application No. 09-280128 for electrically separating a back plate with a container provided with a charging section. Such a structure has become common. 9 and 10 show the structure. That is, reference numeral 1 denotes a container for holding water having an open top, and a heater 2 is attached to the bottom of the container 1 in close contact therewith. Reference numeral 3 denotes a lower frame of a resin main body which covers a lower portion of the container 1. An opening 4 for mounting an electric component is provided on a bottom surface of the lower frame 3, and the opening 4 is usually covered with a metal back plate 5. Has been done. The lower frame 3 is provided with a concave portion 7 having a through hole 6 at the center, and the container 1 is lowered by tightening a screw 8 passing through the through hole 6 from the concave portion 7 side to a container support plate 11 attached to the container 1. It is fixed to the frame 3. The container support plate 11 is formed of a conductive material such as a metal and is electrically connected to the container 1. The head of the screw 8 is made large so that it does not easily buckle when the temperature of the container 1 or the lower frame 3 rises by energizing the electric water heater. Reference numeral 9 denotes a back plate fixing screw for fixing the back plate 5 to the lower frame 3, and the back plate 5 is electrically separated from the container 1 and attached thereto. Reference numeral 10 denotes a wiring in the main body for connecting the heater 2 and the power supply.
[0003]
Next, electrical insulation in the conventional electric kettle will be described. Since the screw 8 fixing the container 1 is submerged in the concave portion 7 and covered with the back plate 5, even if the electric insulation of the heater 2 in the container 1 is broken, the screw 8 which is electrically connected can be touched. There is no. Further, since the back plate 5 is independently fixed to the resin lower frame 3, it is insulated from the container 1.
[0004]
[Problems to be solved by the invention]
However, when exporting the above-described electric water heater to a country that adopts the IEC standard or the like, it is necessary to prevent the wiring 10 from touching the metal back plate 5, so that the insulating structure and parts are not used. It had to be changed from Japan. In addition, when the wiring 10 touches the back plate 5, the back plate 5 needs to be grounded, and there is a problem that the lower frame 3 must be properly used for domestic use and for export.
[0005]
The present invention has been made to solve such a conventional problem, and an object of the present invention is to make it possible to respond to both domestic and export-oriented products with simple modifications.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned conventional problems, the present invention provides a conductive back plate and a conductive member for fixing a container provided with a charging portion for storing water through a hole provided in an insulating lower frame. The lower frame has a recess formed in the portion where the screw of the lower frame penetrates when viewed from the back plate side, and a spacer having a height substantially equal to the depth of the recess is formed on the end face of the bottom of the recess and the back plate. There is a device in which the back plate is fixed to the back plate via the spacer by being inserted into a concave portion so as to be in contact with the back surface.
[0007]
Thereby, for example, when the electric water heater is intended for export, if a conductive screw is passed through the back plate and the lower frame and fastened to the container, the back plate and the container can be electrically connected via the screw. it can. At this time, since the spacer having the same height as the depth of the concave portion is inserted into the concave portion, the back plate is not deformed even if the screw is tightened.
[0008]
Further, when the electric water heater is destined for Japan, a screw for fixing the container and the lower frame and a screw for fixing the back plate and the lower frame may be separated without using a spacer as in the conventional case.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
According to a first aspect of the present invention, there is provided a water supply device comprising: a lower frame of an electrically insulating electric water heater main body having an open bottom surface; a conductive back plate for covering an opening on a lower surface of the lower frame; And a screw that penetrates through the holes provided in the back plate and the lower frame to fix the back plate and the container. And a spacer having substantially the same height as the depth of the concave portion is inserted into the concave portion so as to contact the bottom of the concave portion and the back surface of the back plate, and the back plate is inserted through the spacer. It is fixed. When the electric water heater is intended for export, a conductive screw can be passed through the back plate and the lower frame and fastened to the container, so that the back plate and the container can be electrically connected via the screw. At this time, since the spacer having the same height as the depth of the concave portion is inserted into the concave portion, the back plate is not deformed even if the screw is tightened.
[0010]
Further, the concave portion is circular or regular, and the spacer is cylindrical. The dimension obtained by adding the thickness of one side of the spacer to the inner diameter of the spacer is the radius of the concave portion or one half of one side and the radius of the mounting hole of the back plate. When the screws are tightened from the back plate side, the spacer end face does not block the hole in the back plate even if the spacer is shifted to one side in the recess, making assembly easier. .
[0011]
According to a second aspect of the present invention, there is provided a water supply device comprising: a lower frame of an electrically insulating electric water heater main body having an open bottom surface; a conductive back plate for covering an opening on a lower surface of the lower frame; And a screw that penetrates through the holes provided in the back plate and the lower frame to fix the back plate and the container. And a spacer having substantially the same height as the depth of the concave portion is inserted into the concave portion so as to contact the bottom of the concave portion and the back surface of the back plate, and the back plate is inserted through the spacer. It is fixed. When the electric water heater is intended for export, a conductive screw can be passed through the back plate and the lower frame and fastened to the container, so that the back plate and the container can be electrically connected via the screw. At this time, since the spacer having the same height as the depth of the concave portion is inserted into the concave portion, the back plate is not deformed even if the screw is tightened. Further, the concave portion is circular or square and the spacer is cylindrical, and the dimension obtained by adding the thickness of one side of the spacer to the inner diameter of the spacer is the radius of the concave portion or one half of one side and the screw head for attaching the back plate. Even if the spacer is shifted to one side in the recess, the spacer end face must be under the screw head flat part, making sure that the back plate is deformed when the screw is tightened. Can be prevented .
[0012]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
(Example 1)
1 is a diagram showing a cross section of a main part of a lower portion of the electric water heater of the first embodiment, FIG. 2 is a diagram showing an enlarged cross section of a main part of the electric water heater, and FIG. 3 is a diagram showing a lower surface of the electric water heater. In FIG. 1 to FIG. 3, reference numeral 21 denotes a container for holding water, which is open at the top, and a heater 22 is attached to the bottom of the container 21 in close contact therewith. Reference numeral 23 denotes a resin lower frame that covers a lower portion of the container 21. An opening 24 is provided on the bottom surface of the lower frame 23, and the opening 24 is covered with a metal back plate 25. As shown in FIG. 3, the lower frame 23 is provided with a concave portion 27 having through holes 26 in the upper and lower portions of the center, and a spacer 28 having substantially the same height as the depth of the concave portion 27 is inserted into the concave portion 27. The inner diameter of the cylindrical spacer 28 is set so as to cover the head (dimension d) of the screw 30. The container 21 is fixed to the lower frame 23 by tightening a metal screw 30 passing through the hole 29 of the back plate 25, the spacer 28, and the through hole 26 of the concave portion 27 to a container support plate 33 attached to the container 21. The container support plate 33 is formed of a conductive material such as a metal, and is electrically connected to the container 21. 31 is a wiring in the main body for connecting the heater 22 and the power supply, and 32 is a ground wire connected to the container 21.
[0014]
Next, the operation of the above-described electric kettle will be described. When fixing the container 21, the metal screw 30 is fastened to the container support plate 33 through the hole 29 of the back plate 25, the spacer 28, and the through hole 26 of the recess 27, so that the back plate 25 is electrically connected to the container 21. You are now connected. Then, since the ground wire 32 is connected to the container 21, the back plate 25 electrically connected to the metal is also grounded, and there is no problem even if the wiring 31 touches the back plate 25, such as IEC standard. Can also be exported to countries that have adopted.
[0015]
Further, since the spacer 28 having the same height as the depth of the concave portion 27 is inserted into the concave portion 27, even if the screw 30 is tightened, the back plate 25 is supported and does not deform.
[0016]
Further, when the electric water heater is destined for Japan, a screw for fixing the container 21 and the lower frame 23 and a screw for fixing the back plate 25 and the lower frame 23 may be separated as in the conventional case. You can assemble one for export and one for Japan.
[0017]
Although the spacer 28 has a cylindrical shape in the drawing, the spacer 28 may be any as long as it has a height substantially equal to the depth of the concave portion and through which the screw 30 can pass.
[0018]
(Example 2)
FIG. 4 is a diagram showing a concave section plane and a spacer cross section of a lower frame of an electric water heater showing a second embodiment. In FIG. 4, the dimension a, which is obtained by adding the thickness of one side of the spacer 28 to the inner diameter of the spacer 28, is larger than the dimension obtained by adding the radius b of the concave portion 27 and the radius c of the hole 26 of the back plate 25. When the spacer 28 is tightened from the back plate 25 side, even if the spacer 28 approaches the end in the recess 27, the inner diameter of the spacer 28 exceeds the hole 29 of the back plate 25, so the end face of the spacer 28 closes the hole 29 of the back plate 25. It does not end up.
[0019]
Therefore, even if the spacer 28 is inserted into the concave portion 27, the assembly is not hindered, and the assembly is facilitated.
[0020]
(Example 3)
FIG. 5 is a diagram showing a cross section of a main part of an electric water heater of a third embodiment. In FIG. 5, the dimension a obtained by adding the plate thickness of one side of the spacer 28 to the inner diameter of the spacer 28 is made smaller than the dimension obtained by adding the radius b of the recess 27 and the radius d of the head of the screw 30. The end face of the spacer 28 is always below the plane of the head of the screw 30 even if it is shifted to one side, and it is possible to reliably prevent the back plate 25 from being deformed when the screw 30 is tightened.
[0021]
( Reference Example 1 )
FIG. 6 is a diagram showing a cross section of a main part of the electric water heater of Reference Example 1 . In FIG. 6, the outer diameter of the spacer 28 is larger than the depth of the recess 27. If the spacer 28 falls sideways in the recess 27 during assembly, the spacer 28 jumps out of the recess 27. Then, the back plate 25 rides on the spacer 28 and rises, and it is easily understood that the spacer 28 has fallen.
[0022]
( Reference Example 2 )
FIG. 7 is a diagram showing a cross section of the lower frame concave portion and the spacer of the electric water heater of Reference Example 2 . In FIG. 7, the diameter of the recess 27 is set so as not to be inserted when the spacer 28 is inserted in the horizontal direction. Even if the spacer 28 is accidentally dropped in the recess 27 in the horizontal direction when assembling, the spacer 27 does not enter the recess 27 and is immediately taken out. Can be convenient.
[0023]
( Reference example 3 )
FIG. 8 is a diagram showing a main part plane of a lower frame concave portion of the electric water heater of Reference Example 3 . In FIG. 8, the area of the spacer end face 28a is increased so that the force of pressing the spacer end face 28a and the bottom of the recess 27 does not exceed the thermal deformation stress at the operating temperature of the material forming the lower frame 23. The spacer 28 is formed of a heat-resistant material such as a metal. When the temperature of the container 21 or the lower frame 23 rises by energizing the electric water heater, the spacer 28 gets into the lower frame 23 or the spacer 28 itself is heated. There is no deformation. When the thickness of the spacer 28 is small, the area of the spacer end face 28a may be increased by providing a flange or the like.
[0024]
【The invention's effect】
As described above, according to the present invention, the back plate and the conductive screw for fixing the back plate and the container through the hole provided in the lower frame are provided. A concave portion is provided when viewed from the side, and a spacer having a height substantially equal to the depth of the concave portion is inserted into the concave portion such that the spacer end surface is in contact with the bottom of the concave portion and the back plate. Is required, a conductive screw can be passed through the back plate and the lower frame and fastened to the container support plate to electrically connect the back plate and the container via the screw. At this time, since the spacer having the same height as the depth of the concave portion is inserted into the concave portion, the back plate is not deformed even if the screw is tightened.
[Brief description of the drawings]
1 is a cross-sectional view of a main part of a lower portion of an electric water heater showing a first embodiment of the present invention. [FIG. 2] An enlarged cross-sectional view of a main part of the electric water heater. [FIG. 3] A bottom view of the electric water heater. electrical illustrating a reference example 1 of the main-portion cross-sectional view of an electric water heater showing a third embodiment of a cross-sectional view of the concave plane and the spacer in the lower [5] the present invention of an electric water heater showing embodiment 2 [6] the present invention cross sectional view of a water heater 7 recesses plan view of the lower portion of the electric kettle showing a reference example 3 of a cross-sectional view of the bottom of the recess and the spacer of the electric water heater 8 the invention showing a reference example 2 of the present invention FIG. 9 is a cross-sectional view of a main part of an electric water heater showing a conventional example. FIG. 10 is an enlarged cross-sectional view of a main part of the electric water heater.
21 Container 23 Lower Frame 24 Opening 25 Back Plate 26 Through Hole 27 Depression 28 Spacer 28a Spacer End Face 29 Hole 30 Screw

Claims

A lower frame of an electrically insulating electric water heater main body having an open bottom surface, a conductive back plate covering an opening on a lower surface of the lower frame, a container for storing water with a charging unit, the back plate, and the back plate; The back frame is provided with a conductive screw for fixing the container through the hole provided in the lower frame, and the lower frame is provided with a concave portion as viewed from the back plate side in a portion where the screw penetrates, wherein by inserting a spacer of approximately the same height as the depth of the recess so as to contact the back surface of the back plate and the bottom of the recess to fix the back plate through the spacer into the recess, the recess to no circular The size of the spacer is a square, the spacer is cylindrical, and the dimension obtained by adding the thickness of the spacer to the inner diameter of the spacer is equal to or larger than the dimension obtained by adding the radius of the recess or one half of one side and the radius of the mounting hole of the back plate. Water heater.

A lower frame of an electrically insulating electric water heater main body having an open bottom surface, a conductive back plate covering an opening on a lower surface of the lower frame, a container for storing water with a charging unit, the back plate, and the back plate; The back frame is provided with a conductive screw for fixing the container through the hole provided in the lower frame, and the lower frame is provided with a concave portion as viewed from the back plate side in a portion where the screw penetrates, A spacer having substantially the same height as the depth of the concave portion is inserted into the concave portion so as to abut on the bottom of the concave portion and the back surface of the back plate, and the back plate is fixed via the spacer. The spacer is a square, and the spacer is cylindrical, and the dimension obtained by adding the thickness of the spacer to the inner diameter of the spacer is set to be equal to or less than the dimension obtained by adding the radius of the recess or the half of one side and the radius of the screw head for attaching the back plate. Electric water heater.