JP3814390B2

JP3814390B2 - Water heater joint connection structure of water heater

Info

Publication number: JP3814390B2
Application number: JP31608797A
Authority: JP
Inventors: 辰夫栗山
Original assignee: パロマ工業株式会社
Priority date: 1997-10-30
Filing date: 1997-10-30
Publication date: 2006-08-30
Anticipated expiration: 2017-10-30
Also published as: JPH11132573A

Description

【０００１】
【発明の属する技術分野】
本発明は湯沸器の給水接手接続構造に関し、詳しくは給水配管を接続する金属製の給水接手を合成樹脂製の給水部接続口に接続する湯沸器の給水接手接続構造に関する。
【０００２】
【従来の技術】
従来より、湯沸器には、据え付けたり修理する際に、給水配管をそのまま容易に機器だけを脱着できるように、給水配管と湯沸器との間に、給水接手が設けられる。
また、湯沸器に給水配管を接続する際には、パイプレンチ等の工具を用いて大きなトルクがかかったり、配管後のひずみ力が働くことがあるため、湯沸器の給水部接続口は十分な強度を備えている。
湯沸器の給水配管接続構造は、例えば、図３に示すようなＯリング方式が用いられ、給水配管２７が給水接手２０を介して器具本体の給水部ボディ１の接続口９に接続される。
この給水接手２０は、中心部に貫通孔２８が設けられ、一端に給水配管２７を接続する配管用ねじ部８が設けられ、他端の先端に小径円筒部４と、この小径円筒部４に隣接して大径円筒部５とが設けられ、給水接手２０の中間部外周にはスパナ掛け部２９が設けられる。
また、後述するトガリ先ビス２５の先端が当接し、給水接手２０を位置決めする円錐穴２６が給水接手２０の大径円筒部５の外周面に設けられる。
そして、端部から円筒段部５間の円筒面４にＯリング３が装着され、給水部ボディ１に設けられる接続口９に挿入される。
この接続口９内面には、環状段部が形成され、図示しない給水部に通じる流路２１と、給水接手２の小径円筒部４端部をガイドする小径部２２と、Ｏリング３をシールする中径部と、給水接手２０の挿入方向と直角方向に接続口９の外周側からトガリ先ビス２５がねじ込まれる大径部２３とが設けられる。
そして、トガリ先ビス２５がねじ込まれると、先端が円錐穴２６に当接し、接続口９から給水接手２０が抜け止めされ、回転止めされる。
【０００３】
給水接手２０が接続される給水部ボディ１は、機械的強度をもった腐食しにくい黄銅材料で製作され十分な強度を備えている。
従って、配管接続時の応力によって器具本体の給水部ボディ１が破損することはない。
しかし、湯沸器の部品は、機器を安価に大量生産ができる合成樹脂材料を用いる比率が高まってきており、ことに、給水部ボディ１は、黄銅材料から、安価で、耐食性、軽量化に優れた合成樹脂材料化を図ることが望まれている。
【０００４】
【発明が解決しようとする課題】
しかしながら、器具本体の給水部ボディ１に合成樹脂材料を用いると、強度が劣ることとなって配管接続時に破損しまうおそれがあった。
特に、従来の構造のままで器具本体の給水部ボディ１を合成樹脂化した場合には、配管接続時の回転応力や曲げ応力が給水接手２０に働き、給水接手２０から接続口９の外周に設けたトガリ先ビス２５の取付部に応力が伝えられ、接続口９が破損するおそれがあった。
そこで、本発明の湯沸器の給水接手接続構造は上記課題を解決し、器具本体の給水部ボディを合成樹脂化しても、配管接続時に破損しないようにすることを目的とする。
【０００５】
【課題を解決するための手段】
上記課題を解決する本発明の請求項１記載の湯沸器の給水接手接続構造は、
湯沸器の樹脂製の給水部接続口に、金属製の給水接手を介して給水配管を接続する構造において、
上記給水接手は、水流路が軸方向に形成された管状体の一端に上記給水配管を接続するねじ部と、他端に上記給水部接続口に挿入される円筒管部と、上記円筒管部より中央側で断面外形が非円形の非円筒管部と、中間部にスパナ掛け部とを備えると共に、上記非円筒管部と上記スパナ掛け部との間に溝を有し、
上記給水部接続口は、シール材を介して上記円筒管部と、上記非円筒管部とが嵌入されて、上記円筒管部および非円筒管部と面接触する段状凹部を備え、
上記給水接手の上記円筒管部と上記非円筒管部とを上記段状凹部に嵌入し、上記溝に沿って押さえ板を挿入して、上記接続口の外側から上記非円筒管部の端部を上記給水接手の嵌入方向に押さえることを要旨とする。
【０００６】
また、上記課題を解決する本発明の請求項２記載の湯沸器の給水接手接続構造は、請求項１記載の湯沸器の給水接手接続構造において、
上記給水接手は、上記非円筒管部と上記スパナ掛け部とが同一断面外形を形成すると共に、上記ねじ部の直径より大きな平径を備え、上記同一断面外形を備えた棒材により製作されることを要旨とする。
【０００７】
上記構成を有する本発明の請求項１記載の湯沸器の給水接手接続構造は、給水接手に設けた非円形の非円筒管部が給水部接続口の段状凹部に嵌入し、溝に沿って押さえ板を挿入し、接続口の外側から非円筒管部の端部を給水接手の嵌入方向に押さえて給水接手を接続口に接続する。
つまり、給水接手は、非円筒管部が非円形であるため、給水部接続口の段状凹部に嵌合して回転方向に位置決めされる。また、押さえ板が非円筒管部の端部を給水接手の嵌入方向に押さえて抜け止めする。
従って、配管接続時に給水接手に働く回転応力は、非円筒管部が嵌合して受け、一点に集中せずに分散化すると共に、曲げ応力は、押さえ板で受けるため、給水部接続口が合成樹脂であっても破損しない。
その結果、湯沸器は、給水部接続口を樹脂化することができるため、製造コストを低減でき、耐食性を向上し、軽量化を図ることができる。
【０００８】
また、上記構成を有する本発明の請求項２記載の湯沸器の給水接手接続構造は、給水接手の非円筒管部とスパナ掛け部とが同一断面外形に形成されると共に、ねじ部の直径より大きな平径を備え、これらと同一断面外形を備えた棒材により製作される。
従って、給水接手のスパナ掛け部および非円筒管部は、切削加工されずに素材の外形形状のままで形成される。
その結果、給水接手は、加工面が少なくなって製造コストが低減する。
【０００９】
【発明の実施形態】
以上説明した本発明の構成・作用を一層明らかにするために、以下本発明の配管の接続部の好適な実施例について説明する。
図１は一実施例として、湯沸器における給水配管の接続部であり、組み込み状態の断面図を示している。
湯沸器は、給水配管設備に手を加えることなく容易に機器だけを交換したり、取り外して修理できるように、給水接手２を介して給水配管２７と接続される。給水接手２は、六角棒材を切削加工して作製され、中心部に給水路となる貫通孔２８が設けられ、先端から順に、外周面にＯリング３を装着する小径円筒部４と、給水接手２をガイドする中径円筒部５と、六角棒材の外形そのままの六角部６ａと、後述する押さえ板１０を装着する溝部７と、同様に六角棒材をそのままに素材外形を利用してスパナ掛けにする六角部６ｂと、給水配管２７を接続するねじ部８とを備える。
【００１０】
一方、湯沸器側の給水部ボディ１は、機械的強度の優れたＰＰＳ（ポリフェニレンサルファイト）等の合成樹脂材料が用いられて成形される。
給水接手２を接続する接続口９の内面には、奥から口元に向かって内径が異なる環状段部が形成され、図示しない給水部に通じる流路１１と、給水接手２を挿入方向にガイドする小径部１２と、Ｏリング３のシート面となる中径部１３とが設けられる。そして、口元には、給水接手２の六角部６ａを嵌合して位置決めする六角嵌合部１４が形成される（図２）。
また、中心部を略Ｕ字形状に切り欠き、左右にビスねじ孔を備えた板状の押さえ板１０が設けられ、接続口９の外周面には、この押さえ板１０を接続口９に固定するビス１５が設けられる。更に、押さえ板１０をケーシングに固定する止めビス１６が設けられる。
【００１１】
次に、器具本体に給水配管２７を接続する場合について説明する。
給水接手２は、小径円筒部４にＯリング３を装着し、六角部６ａが接続口９の六角嵌合部１４に合致するように給水部ボディ１の接続口９へ挿入される（図２）。
そして、給水接手２の溝部７に押さえ板１０がスライドしてはめ込まれ、押さえ板１０は、給水部ボディ１の接続口９へビス止めされると共に、湯沸器のケーシングに固定される。
【００１２】
器具本体に給水配管２７を接続する場合には、器具本体から給水接手２を取り外して給水配管２７と接続し、その後に給水接手２を器具本体に接続する方法と、器具本体に給水接手２を取り付けたまま給水配管２７と接続する方法とがある。
ここでは、器具本体へ配管接続時の応力が負荷され易い場合、即ち、器具本体に給水接手２を取り付けたまま給水配管２７と接続する場合について説明する。
【００１３】
給水配管２７を接続する場合には、給水接手２の六角部６ｂにスパナを掛けて給水接手２をバックアップしながら、給水配管２７を給水接手２のねじ部８にねじ込む。
この場合に、スパナでバックアップしない場合には、給水配管２７の回転応力がそのまま給水接手２を介して給水部ボディ１に伝達される。
しかし、給水接手２の六角部６ａは、接続口９の六角嵌合部１４に嵌合しており、六角部６ａの６面に当接して回転が阻止され、回転応力が周囲６面に分散する。
従って、集中的な応力を避けることができ、給水部ボディ１側が合成樹脂材料で製作されている場合であっても、接続口９の破損を防止することができる。
また、配管時に、給水接手２へ曲げ応力がかかる場合には、ケーシングに接続した押さえ板１０が曲げ応力を受け止めて接続口９の破損を防止することができる。
以上のことから、給水接手２に接続される湯沸器の給水部ボディ１を合成樹脂化しても、給水部ボディ１は破損または変形を起こさない。
【００１４】
以上本発明の実施例について説明したが、本発明はこうした実施例に何等限定されるものではなく、本発明の要旨を逸脱しない範囲において、種々なる態様で実施し得ることは勿論である。
例えば、回転止めとなる六角部６ａは、六角形状に限定されず、面接触して回転止めとなる形状であれば、三角形、四角形、五角形等、他の多角形や楕円、半丸であっても良い。
【００１５】
また、給水接手２の溝部７の底は、軸中心から所定半径をもった円筒面であるが、例えば、溝部７の底面に平切り面を形成し、押さえ板１０の中心孔形状を平切り面に嵌合して回転止めとなるように形成し、給水接手２の回転応力を押さえ板１０で受け止めるようにしても良い。
この場合には、六角部６ａに加えて押さえ板１０が回転止めとなり、回転応力が押さえ板１０にも分散される。
【００１６】
【発明の効果】
以上詳述したように、本発明の請求項１記載の湯沸器の給水接手接続構造によれば、給水接手が接続される給水部接続口が合成樹脂であっても、配管接続時の応力が分散化され、配管接続時に給水部接続口が破損しない。
従って、湯沸器は、給水部の樹脂化が容易となって、製造コストを低減でき、耐食性を向上し、軽量化を図ることができるという優れた効果を奏する。
【００１７】
また、請求項２記載の湯沸器の給水接手接続構造によれば、請求項１記載の効果に加えて、給水接手のスパナ掛け部および非円筒管部は、同一断面形状をもった棒材を用いて、素材の外形形状をそのまま利用でき、切削加工が不要となる。
従って、給水接手の切削加工面が少なくなって製造コストが低減する。
【図面の簡単な説明】
【図１】一実施例としての給水接手接続構造の概略構成図である。
【図２】六角部の嵌合を示す断面図である。
【図３】従来例としての給水接手接続構造の概略構成図である。
【符号の説明】
１給水部ボディ
２給水接手
３Ｏリング
６ａ六角部
８ねじ部
９接続口
１０押さえ板
１４六角嵌合部
１５ビス[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water supply joint connection structure for a water heater, and more particularly to a water supply joint connection structure for a water heater for connecting a metal water supply joint for connecting a water supply pipe to a water supply port connection port made of synthetic resin.
[0002]
[Prior art]
Conventionally, when a water heater is installed or repaired, a water supply joint is provided between the water supply pipe and the water heater so that only the equipment can be easily detached from the water supply pipe.
Also, when connecting the water supply pipe to the water heater, a large torque may be applied using a tool such as a pipe wrench, or the strain force after the pipe may work. It has sufficient strength.
For example, an O-ring system as shown in FIG. 3 is used for the water supply pipe connection structure of the water heater, and the water supply pipe 27 is connected to the connection port 9 of the water supply body 1 of the appliance body via the water supply joint 20. .
This water supply joint 20 is provided with a through hole 28 at the center, a pipe thread portion 8 for connecting a water supply pipe 27 at one end, a small diameter cylindrical portion 4 at the tip of the other end, and the small diameter cylindrical portion 4. A large-diameter cylindrical portion 5 is provided adjacently, and a spanner hanging portion 29 is provided on the outer periphery of the intermediate portion of the water supply joint 20.
In addition, a conical hole 26 for positioning the water supply joint 20 is provided on the outer peripheral surface of the large-diameter cylindrical portion 5 of the water supply joint 20.
Then, the O-ring 3 is mounted on the cylindrical surface 4 between the cylindrical stepped portion 5 from the end portion, and is inserted into the connection port 9 provided in the water supply body 1.
An annular step portion is formed on the inner surface of the connection port 9 to seal the flow path 21 leading to a water supply portion (not shown), the small diameter portion 22 that guides the end of the small diameter cylindrical portion 4 of the water supply joint 2, and the O-ring 3. A medium-diameter portion and a large-diameter portion 23 into which the screw tip screw 25 is screwed from the outer peripheral side of the connection port 9 are provided in a direction perpendicular to the insertion direction of the water supply joint 20.
Then, when the screw tip screw 25 is screwed in, the tip comes into contact with the conical hole 26, and the water supply joint 20 is prevented from coming off from the connection port 9 and is prevented from rotating.
[0003]
The water supply body 1 to which the water supply joint 20 is connected is manufactured from a brass material having mechanical strength and hardly corroded, and has sufficient strength.
Therefore, the water supply part body 1 of the instrument body is not damaged by the stress at the time of pipe connection.
However, the proportion of water heater parts that use synthetic resin materials that can be mass-produced at low cost has been increasing. In particular, the water supply body 1 is made of brass material at low cost, corrosion resistance, and weight reduction. It is desired to make an excellent synthetic resin material.
[0004]
[Problems to be solved by the invention]
However, when a synthetic resin material is used for the water supply unit body 1 of the instrument body, the strength is inferior, and there is a possibility that the pipe will be damaged at the time of pipe connection.
In particular, when the water supply body 1 of the appliance main body is made of a synthetic resin with the conventional structure, rotational stress and bending stress at the time of pipe connection work on the water supply joint 20 and from the water supply joint 20 to the outer periphery of the connection port 9. The stress is transmitted to the mounting portion of the provided tip screw 25, and the connection port 9 may be damaged.
Then, the water supply joint connection structure of the water heater of this invention aims at solving the said subject and preventing it at the time of piping connection, even if it uses synthetic resin for the water supply part body of an instrument main body.
[0005]
[Means for Solving the Problems]
The water supply joint connection structure of the water heater according to claim 1 of the present invention for solving the above-mentioned problem is as follows.
In the structure where the water supply pipe is connected to the resin water supply connection port of the water heater through a metal water supply joint,
The water supply joint includes a threaded portion that connects the water supply pipe to one end of a tubular body in which a water flow path is formed in the axial direction, a cylindrical tube portion that is inserted into the water supply port connection port at the other end, and the cylindrical tube portion A non-cylindrical tube portion having a non-circular cross-sectional profile at the center side, and a spanner hanging portion at the intermediate portion, and a groove between the non-cylindrical tube portion and the spanner hanging portion,
The water supply port is provided with a stepped recess in which the cylindrical tube portion and the non -cylindrical tube portion are fitted via a sealing material and in surface contact with the cylindrical tube portion and the non-cylindrical tube portion ,
The cylindrical tube portion and the non-cylindrical tube portion of the water supply joint are fitted into the stepped recess, a pressing plate is inserted along the groove, and the end portion of the non-cylindrical tube portion from the outside of the connection port The gist is to hold down in the insertion direction of the water supply joint.
[0006]
Moreover, the water supply joint connection structure of the water heater according to claim 2 of the present invention that solves the above problem is the water supply joint connection structure of the water heater according to claim 1,
In the water supply joint, the non-cylindrical tube portion and the spanner hanging portion have the same cross-sectional outer shape, and have a flat diameter larger than the diameter of the threaded portion, and are manufactured by a bar material having the same cross-sectional outer shape. This is the gist.
[0007]
In the water supply joint connection structure for a water heater according to claim 1 having the above-described configuration, a non-circular non-cylindrical tube part provided in the water supply joint is fitted into a stepped recess of the water supply part connection port, along the groove. Insert the holding plate and press the end of the non-cylindrical tube part from the outside of the connection port in the insertion direction of the water supply joint to connect the water supply joint to the connection port.
That is, since the non-cylindrical tube part is non-circular, the water supply joint is fitted in the stepped recess of the water supply part connection port and positioned in the rotational direction. Further, the pressing plate holds the end of the non-cylindrical tube portion in the direction of fitting the water supply joint to prevent it from coming off.
Therefore, the rotational stress acting on the water supply joint when connecting the pipe is received by the non-cylindrical pipe part, and it is dispersed without concentrating on one point, and the bending stress is received by the holding plate. Even a synthetic resin does not break.
As a result, since the water heater can be resinized at the water supply port, the manufacturing cost can be reduced, the corrosion resistance can be improved, and the weight can be reduced.
[0008]
In the water supply joint connection structure of the water heater according to claim 2 of the present invention having the above-described configuration, the non-cylindrical tube portion and the spanner hooking portion of the water supply joint are formed in the same cross-sectional outline, and the diameter of the thread portion Manufactured by a bar having a larger flat diameter and the same cross-sectional profile as these.
Therefore, the spanner hooking portion and the non-cylindrical tube portion of the water supply joint are formed without changing the cutting shape.
As a result, the water supply joint has a reduced processing surface and manufacturing costs.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the pipe connecting portion of the present invention will be described below.
FIG. 1 shows, as an example, a connection portion of a water supply pipe in a water heater, and shows a sectional view in an assembled state.
The water heater is connected to the water supply pipe 27 via the water supply joint 2 so that only the equipment can be easily replaced or removed and repaired without modifying the water supply pipe facility. The water supply joint 2 is manufactured by cutting a hexagonal bar, and a through-hole 28 serving as a water supply channel is provided at the center, and a small diameter cylindrical portion 4 in which an O-ring 3 is attached to the outer peripheral surface in order from the tip, and a water supply A medium-diameter cylindrical portion 5 that guides the joint 2, a hexagonal portion 6 a that is the outer shape of the hexagonal bar, a groove portion 7 that is mounted with a presser plate 10 that will be described later, and a material outer shape that uses the hexagonal bar as it is. A hexagonal portion 6b for spanner hooking and a screw portion 8 for connecting the water supply pipe 27 are provided.
[0010]
On the other hand, the water supply body 1 on the water heater side is molded using a synthetic resin material such as PPS (polyphenylene sulfite) having excellent mechanical strength.
On the inner surface of the connection port 9 for connecting the water supply joint 2, an annular step portion having a different inner diameter from the back toward the mouth is formed, and the channel 11 leading to the water supply unit (not shown) and the water supply joint 2 are guided in the insertion direction. A small-diameter portion 12 and a medium-diameter portion 13 that serves as a seat surface of the O-ring 3 are provided. And the hexagonal fitting part 14 which fits and positions the hexagonal part 6a of the water supply joint 2 is formed in a mouth (FIG. 2).
In addition, a plate-shaped pressing plate 10 having a central U-shaped notch and screw screw holes on the left and right sides is provided, and the pressing plate 10 is fixed to the connection port 9 on the outer peripheral surface of the connection port 9. A screw 15 is provided. Furthermore, a stop screw 16 for fixing the presser plate 10 to the casing is provided.
[0011]
Next, a case where the water supply pipe 27 is connected to the instrument body will be described.
The water supply joint 2 has the O-ring 3 attached to the small diameter cylindrical portion 4 and is inserted into the connection port 9 of the water supply unit body 1 so that the hexagonal portion 6a matches the hexagonal fitting portion 14 of the connection port 9 (FIG. 2). ).
The presser plate 10 is slid and fitted into the groove 7 of the water supply joint 2, and the presser plate 10 is screwed to the connection port 9 of the water supply unit body 1 and is fixed to the casing of the water heater.
[0012]
When the water supply pipe 27 is connected to the instrument body, the water supply joint 2 is removed from the instrument body and connected to the water supply pipe 27, and then the water supply joint 2 is connected to the instrument body, and the water supply joint 2 is connected to the instrument body. There is a method of connecting to the water supply pipe 27 while being attached.
Here, the case where the stress at the time of pipe connection to the instrument body is easily applied, that is, the case where the instrument body is connected to the water supply pipe 27 while the water supply joint 2 is attached will be described.
[0013]
When the water supply pipe 27 is connected, the water supply pipe 27 is screwed into the threaded portion 8 of the water supply joint 2 while a spanner is put on the hexagonal portion 6 b of the water supply joint 2 to back up the water supply joint 2.
In this case, when not backed up by a spanner, the rotational stress of the water supply pipe 27 is directly transmitted to the water supply body 1 through the water supply joint 2.
However, the hexagonal portion 6a of the water supply joint 2 is fitted to the hexagonal fitting portion 14 of the connection port 9, and is in contact with the six surfaces of the hexagonal portion 6a to prevent rotation, so that rotational stress is distributed to the six surrounding surfaces. To do.
Therefore, concentrated stress can be avoided, and even if the water supply body 1 side is made of a synthetic resin material, damage to the connection port 9 can be prevented.
Further, when bending stress is applied to the water supply joint 2 during piping, the holding plate 10 connected to the casing can receive the bending stress and prevent the connection port 9 from being damaged.
From the above, even when the water supply body 1 of the water heater connected to the water supply joint 2 is made of synthetic resin, the water supply body 1 is not damaged or deformed.
[0014]
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention.
For example, the hexagonal portion 6a serving as a rotation stopper is not limited to a hexagonal shape, and may be other polygons such as a triangle, a quadrangle, a pentagon, etc. Also good.
[0015]
In addition, the bottom of the groove portion 7 of the water supply joint 2 is a cylindrical surface having a predetermined radius from the axial center. For example, a flat surface is formed on the bottom surface of the groove portion 7 and the center hole shape of the holding plate 10 is flatly cut. It may be formed so that it is fitted to the surface to prevent rotation, and the rotational stress of the water supply joint 2 is received by the pressing plate 10.
In this case, in addition to the hexagonal portion 6 a, the pressing plate 10 is prevented from rotating, and the rotational stress is also distributed to the pressing plate 10.
[0016]
【The invention's effect】
As described above in detail, according to the water supply joint connection structure of the water heater according to claim 1 of the present invention, even when the water supply connection port to which the water supply joint is connected is a synthetic resin, the stress at the time of pipe connection Is distributed and the water supply connection port is not damaged when the pipe is connected.
Therefore, the water heater has an excellent effect that the water supply section can be easily made into a resin, the manufacturing cost can be reduced, the corrosion resistance can be improved, and the weight can be reduced.
[0017]
Further, according to the water supply joint connection structure of the water heater according to claim 2, in addition to the effect of claim 1, the spanner hanging portion and the non-cylindrical tube portion of the water supply joint have the same cross-sectional shape. With this, the outer shape of the material can be used as it is, and cutting is not necessary.
Therefore, the cutting surface of the water supply joint is reduced and the manufacturing cost is reduced.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a water supply joint connection structure as one embodiment.
FIG. 2 is a cross-sectional view showing fitting of a hexagonal portion.
FIG. 3 is a schematic configuration diagram of a water supply joint connection structure as a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Water supply part body 2 Water supply joint 3 O ring 6a Hexagon part 8 Screw part 9 Connection port 10 Holding plate 14 Hexagon fitting part 15 Screw

Claims

In the structure where the water supply pipe is connected to the resin water supply connection port of the water heater through a metal water supply joint,
The water supply joint includes a threaded portion that connects the water supply pipe to one end of a tubular body in which a water flow path is formed in the axial direction, a cylindrical tube portion that is inserted into the water supply port connection port at the other end, and the cylindrical tube portion A non-cylindrical tube portion having a non-circular cross-sectional profile at the center side, and a spanner hanging portion at the intermediate portion, and a groove between the non-cylindrical tube portion and the spanner hanging portion,
The water supply port is provided with a stepped recess in which the cylindrical tube portion and the non -cylindrical tube portion are fitted via a sealing material and in surface contact with the cylindrical tube portion and the non-cylindrical tube portion ,
The cylindrical tube portion and the non-cylindrical tube portion of the water supply joint are fitted into the stepped recess, a pressing plate is inserted along the groove, and the end portion of the non-cylindrical tube portion from the outside of the connection port A water supply joint connection structure for a water heater, wherein the water supply joint is pressed in the fitting direction.

In the water supply joint, the non-cylindrical tube portion and the spanner hanging portion have the same cross-sectional outer shape, and have a flat diameter larger than the diameter of the screw portion, and are manufactured by a bar material having the same cross-sectional outer shape. The water supply joint connection structure for a water heater according to claim 1.