JP2021156536A

JP2021156536A - Water heater

Info

Publication number: JP2021156536A
Application number: JP2020059277A
Authority: JP
Inventors: 賢祐山口; Kensuke Yamaguchi
Original assignee: Paloma Co Ltd
Current assignee: Paloma Co Ltd
Priority date: 2020-03-30
Filing date: 2020-03-30
Publication date: 2021-10-07
Anticipated expiration: 2040-03-30
Also published as: JP7406797B2

Abstract

To provide a water heater capable of preventing back flow of hot water of a circulation heating circuit side, to a hot water supply circuit side.SOLUTION: A break-off valve unit 2 is disposed in a pipe conduit connecting a hot water supply circuit and a circulation heating circuit. Hot water flowing from a hot water supply circuit side is guided to a flow channel 95A. A hot water supply-side check valve 70 is disposed on the flow channel 95A. Flow channels 97-99 and a valve housing portion are communicated to the flow channel 95A. The valve housing portion is provided with a break-off valve 73. The break-off valve 73 is constantly energized in a valve opening direction by spring force of a spring 732, and energized in a valve closing direction against the spring force by receiving a back pressure from the hot water supply circuit. An upstream-side end portion of a flow channel 96 is communicated to the flow channel 97 at a lower position with respect to the flow channel 95A, and a downstream-side end portion is connected to the circulation heating circuit. The flow channel 96 is provided with a second circulation-side check valve 72. Even when the hot water flows back from the circulation heating circuit side, and passes over the second circulation-side check valve 72, the force is reduced during rising in the flow channel 97.SELECTED DRAWING: Figure 4

Description

本発明は、給湯器に関する。 The present invention relates to a water heater.

従来、給湯器には、給湯回路と循環加熱回路とを接続する管路に、縁切り弁ユニットが設けられる。縁切り弁ユニットは、循環加熱回路側から給湯回路側への湯水の逆流を防止する。縁切り弁ユニットの一例として、共用のボディに、開閉弁、二つの逆止弁及び大気開放弁を組み付けた制御弁ユニットが知られている（例えば、特許文献１参照）。この制御弁ユニットでは、開閉弁を開閉させることにより浴槽への湯水の供給が許容又は遮断される。開閉弁の下流側に二つの逆止弁が順次設けられ、浴槽側（二次側）から給湯装置側（一次側）への湯水の逆流を二重に防止する。断水や停電によって一次側の水圧が負圧になったとしても、大気開放弁がその一次側の圧力低下に応動して二つの逆止弁の間の空間を大気に開放する。そして、仮に浴槽側の水が下流側の逆止弁を越えたとしても、その開放された空間から外部に排出される。 Conventionally, in a water heater, an edge cut valve unit is provided in a pipeline connecting a hot water supply circuit and a circulation heating circuit. The edge cut valve unit prevents backflow of hot water from the circulation heating circuit side to the hot water supply circuit side. As an example of the edge cut valve unit, a control valve unit in which an on-off valve, two check valves, and an air release valve are assembled to a common body is known (see, for example, Patent Document 1). In this control valve unit, the supply of hot water to the bathtub is allowed or cut off by opening and closing the on-off valve. Two check valves are sequentially provided on the downstream side of the on-off valve to prevent double backflow of hot water from the bathtub side (secondary side) to the water heater side (primary side). Even if the water pressure on the primary side becomes negative due to a water outage or a power outage, the atmospheric release valve responds to the pressure drop on the primary side and opens the space between the two check valves to the atmosphere. Then, even if the water on the bathtub side exceeds the check valve on the downstream side, the water is discharged to the outside from the open space.

特開２０１８−９１３９６号公報Japanese Unexamined Patent Publication No. 2018-91396

しかしながら、特許文献１に記載の制御弁ユニットでは、二つの逆止弁間の流路が水平且つ直線的に形成されているため、二次側と一次側との圧力差が大きくなると、二次側を流れる湯水が下流側の逆止弁を勢いよく越えて制御弁ユニットに侵入し、大気開放弁に連通する箇所を越えて勢いを保ったまま上流側の逆止弁に到達し、一次側へ侵入する可能性があった。 However, in the control valve unit described in Patent Document 1, since the flow path between the two check valves is formed horizontally and linearly, when the pressure difference between the secondary side and the primary side becomes large, the secondary side is secondary. The hot water flowing on the side vigorously crosses the check valve on the downstream side and enters the control valve unit, and reaches the check valve on the upstream side while maintaining the momentum beyond the point where it communicates with the air release valve, and reaches the primary side. There was a possibility of invading.

本発明の目的は、循環加熱回路側の湯水が給湯回路側に逆流するのを防止できる給湯器を提供することである。 An object of the present invention is to provide a water heater capable of preventing hot water on the circulation heating circuit side from flowing back to the hot water supply circuit side.

請求項１の給湯器は、給湯回路と循環加熱回路を接続する管路に、前記循環加熱回路側から前記給湯回路側への湯水の逆流を防止する為の縁切り弁ユニットを設けた給湯器において、前記縁切り弁ユニットは、水平方向に沿って設けられ、前記給湯回路側から湯水が案内されると共に、前記循環加熱回路側からの湯水の逆流を防止する第１逆止弁が設けられる上流側経路部と、前記上流側経路部と連通すると共に、バネ力により常時開弁方向に付勢され、前記給湯回路からの背圧を受けて前記バネ力に抗して閉弁方向に付勢される縁切り弁が設けられる排出経路部と、水平方向に沿って設けられ、湯水が流れる方向の上流側の端部である上流側端部が、前記上流側経路部よりも下位位置で前記排出経路部と連通し、前記上流側端部とは反対側の下流側端部が前記循環加熱回路と接続し、前記上流側端部と前記下流側端部の間に、前記循環加熱回路側からの湯水の逆流を防止する第２逆止弁が設けられる下流側経路部とを備えたことを特徴とする。 The water heater according to claim 1 is a water heater in which a check valve unit for preventing backflow of hot water from the circulation heating circuit side to the hot water supply circuit side is provided in a pipeline connecting the hot water supply circuit and the circulation heating circuit. The edge cut valve unit is provided along the horizontal direction, and the hot water is guided from the hot water supply circuit side, and the upstream side where the first check valve for preventing the backflow of hot water from the circulation heating circuit side is provided. In addition to communicating with the path portion and the upstream path portion, it is constantly urged in the valve opening direction by a spring force, and is urged in the valve closing direction against the spring force by receiving the back pressure from the hot water supply circuit. The discharge path portion where the check valve is provided and the upstream end portion which is provided along the horizontal direction and is the end portion on the upstream side in the direction in which the hot water flows flows, are located at a position lower than the upstream side path portion. The downstream end on the opposite side of the upstream end is connected to the circulation heating circuit, and between the upstream end and the downstream end, from the circulation heating circuit side. It is characterized by having a downstream path portion provided with a second check valve for preventing the backflow of hot water.

請求項２の給湯器の前記排出経路部は、上下方向に沿って設けられていてもよい。 The discharge path portion of the water heater according to claim 2 may be provided along the vertical direction.

請求項３の給湯器の前記下流側経路部は、前記下流側経路部と並列に設けられ、湯水が流れる方向の上流側の端部である上流側端部が、前記上流側経路部と前記下流側経路部の間の高さ位置で、前記排出経路部と連通し、前記上流側端部とは反対側の下流側端部が連通路を介して前記下流側経路部の前記第２逆止弁と連通し、前記上流側端部と前記下流側端部の間に、前記循環加熱回路側からの湯水の逆流を防止する第三逆止弁が設けられる並列経路部を備えてもよい。 The downstream route portion of the water heater according to claim 3 is provided in parallel with the downstream route portion, and the upstream end portion, which is the upstream end portion in the direction in which hot water flows, is the upstream route portion and the upstream route portion. At a height position between the downstream path portions, the downstream end portion on the opposite side of the upstream end portion communicates with the discharge path portion, and the downstream end portion on the opposite side of the upstream end portion passes through the communication passage to the second reverse of the downstream route portion. A parallel path portion that communicates with the stop valve and is provided with a third check valve that prevents the backflow of hot water from the circulation heating circuit side may be provided between the upstream side end portion and the downstream side end portion. ..

請求項１の給湯器によれば、下流側経路部と上流側経路部との間に排出経路部の一部を介して高低差が形成される。よって、循環加熱回路側の圧力が高まり、仮に湯水が下流側経路部側の第２逆止弁を乗り越えたとしても、排出経路部内を上昇するまでの間にその勢いが減少される。それ故、下流側経路部の第２逆止弁を乗り越えた湯水は、上流側経路部に達することなく、排出経路部内を下方に落ちるか、仮に上流側経路部に達したとしても、上流側経路部の第１逆止弁を乗り越えることはなく、排出経路部内を下方に落ちる。従って、給湯器は、循環加熱回路側の湯水が給湯回路側に逆流するのを確実に防止できる。 According to the water heater of claim 1, a height difference is formed between the downstream route portion and the upstream route portion through a part of the discharge route portion. Therefore, even if the pressure on the circulation heating circuit side increases and the hot water gets over the second check valve on the downstream side path portion side, the momentum is reduced until it rises in the discharge path portion. Therefore, the hot water that has passed through the second check valve of the downstream path section falls downward in the discharge path section without reaching the upstream path section, or even if it reaches the upstream path section, it reaches the upstream side. It does not get over the first check valve of the path section and falls down in the discharge path section. Therefore, the water heater can surely prevent the hot water on the circulation heating circuit side from flowing back to the hot water supply circuit side.

請求項２の給湯器によれば、縁切り弁ユニットにおいて、排出経路部は上下方向に沿って設けられるので、排出経路部に流入した水を排出経路部に沿って落下させることができる。 According to the water heater of claim 2, since the discharge path portion is provided along the vertical direction in the edge cut valve unit, the water flowing into the discharge path portion can be dropped along the discharge path portion.

請求項３の給湯器によれば、縁切り弁ユニットにおいて、並列経路部を備えるので、循環加熱回路側に流れる湯水の通過面積を広く確保でき、湯水通過時の圧損を小さくできる。これにより、寒冷地での使用を考慮して、仮に第２逆止弁、第３逆止弁の閉弁する力を強く設定したとしても、給湯回路から循環加熱回路への供給水量が少なくなるのを防止できる。その結果、寒冷地用の給湯器を別個用意する必要が無くなるので、管理コストを低減できる。 According to the water heater of claim 3, since the edge cut valve unit is provided with a parallel path portion, a wide passage area of hot water flowing to the circulation heating circuit side can be secured, and pressure loss at the time of passing hot water can be reduced. As a result, even if the closing force of the second check valve and the third check valve is strongly set in consideration of use in cold regions, the amount of water supplied from the hot water supply circuit to the circulation heating circuit is reduced. Can be prevented. As a result, it is not necessary to separately prepare a water heater for cold regions, so that the management cost can be reduced.

給湯器１の斜視図である。It is a perspective view of the water heater 1. 給湯器１の内部構成図である。It is an internal block diagram of a water heater 1. 縁切り弁ユニット２の斜視図である。It is a perspective view of the edge cutting valve unit 2. 図３に示すＩ−Ｉ線矢視方向断面図である。FIG. 3 is a cross-sectional view taken along the line II in the direction of arrow shown in FIG. 図３に示すＩＩ−ＩＩ線矢視方向断面図である。FIG. 3 is a cross-sectional view taken along the line II-II shown in FIG. 不凍栓４００の構成を示す図である。It is a figure which shows the structure of the antifreeze plug 400.

以下、本発明の実施形態を説明する。以下に記載される装置の構造などは、特定的な記載がない限り、それのみに限定する趣旨ではなく、単なる説明例である。図面は、本発明が採用しうる技術的特徴を説明する為に用いられるものである。 Hereinafter, embodiments of the present invention will be described. Unless otherwise specified, the structure of the device described below is not intended to be limited thereto, but is merely an example of explanation. The drawings are used to illustrate the technical features that can be adopted by the present invention.

図１、図２を参照し、給湯器１の構成を簡単に説明する。図１に示すように、給湯器１は、筐体１Ａと蓋１Ｂを備える。筐体１Ａの底部には、図２に示す給水接続口３７、給湯接続口３６、ガス接続口３８、及び排水口３９が設けられる。筐体１Ａの前面から蓋１Ｂを取り外すと、筐体１Ａの内側が露出する。図２に示すように、筐体１Ａの内側には、給湯回路１１、循環加熱回路１２、湯水供給管２０６、及び縁切り弁ユニット２等が設けられる。なお、図２は、筐体１Ａ内の各構成の配置を分かり易く便宜的に図示したものであり、各配管の向きは、実際の配管の向きと一部異なる。 The configuration of the water heater 1 will be briefly described with reference to FIGS. 1 and 2. As shown in FIG. 1, the water heater 1 includes a housing 1A and a lid 1B. The bottom of the housing 1A is provided with a water supply connection port 37, a hot water supply connection port 36, a gas connection port 38, and a drainage port 39 shown in FIG. When the lid 1B is removed from the front surface of the housing 1A, the inside of the housing 1A is exposed. As shown in FIG. 2, a hot water supply circuit 11, a circulation heating circuit 12, a hot water supply pipe 206, an edge cut valve unit 2, and the like are provided inside the housing 1A. Note that FIG. 2 is an easy-to-understand illustration of the arrangement of each configuration in the housing 1A, and the orientation of each pipe is partially different from the actual orientation of the piping.

給湯回路１１は、流入管１０１、給湯バーナ１０２、一次熱交換器１０３、二次熱交換器１０４、出湯管１０５、及び分岐管１０６等を備える。給湯バーナ１０２、一次熱交換器１０３、及び二次熱交換器１０４は、燃焼室８内に設けられる。給水接続口３７から流入した水は流入管１０１を流れ、二次熱交換器１０４、一次熱交換器１０３の順に流れる。一次熱交換器１０３は、給湯バーナ１０２からの燃焼排気中の顕熱を回収し、二次熱交換器１０４は、給湯バーナ１０２からの燃焼排気中の潜熱を回収し、通水を加熱する。出湯管１０５は、一次熱交換器１０３の出口と、縁切り弁ユニット２の後述する接続口３５（図３参照）の間に接続される。一次熱交換器１０３と二次熱交換器１０４において加熱された湯水は出湯管１０５を流れ、縁切り弁ユニット２を介して給湯接続口３６から外部に供給される（図３に示す矢印Ｂ参照）。分岐管１０６は、流入管１０１の上流側において分岐し、縁切り弁ユニット２の後述する流入管６３３の接続口６７（図３参照）に接続される。 The hot water supply circuit 11 includes an inflow pipe 101, a hot water supply burner 102, a primary heat exchanger 103, a secondary heat exchanger 104, a hot water outlet pipe 105, a branch pipe 106, and the like. The hot water supply burner 102, the primary heat exchanger 103, and the secondary heat exchanger 104 are provided in the combustion chamber 8. The water flowing in from the water supply connection port 37 flows through the inflow pipe 101, and then flows in the order of the secondary heat exchanger 104 and the primary heat exchanger 103. The primary heat exchanger 103 recovers the sensible heat in the combustion exhaust from the hot water supply burner 102, and the secondary heat exchanger 104 recovers the latent heat in the combustion exhaust from the hot water supply burner 102 to heat the water flow. The hot water outlet pipe 105 is connected between the outlet of the primary heat exchanger 103 and the connection port 35 (see FIG. 3) of the edge cut valve unit 2, which will be described later. The hot water heated in the primary heat exchanger 103 and the secondary heat exchanger 104 flows through the hot water outlet pipe 105 and is supplied to the outside from the hot water supply connection port 36 via the edge cut valve unit 2 (see arrow B shown in FIG. 3). .. The branch pipe 106 branches on the upstream side of the inflow pipe 101 and is connected to the connection port 67 (see FIG. 3) of the inflow pipe 633 described later in the edge cut valve unit 2.

循環加熱回路１２は、風呂戻り管２０１、風呂往き管２０２、風呂バーナ２０３、風呂一次熱交換器２０４、風呂二次熱交換器２０５、湯水供給管２０６、及びポンプ２０７等を備える。風呂バーナ２０３、風呂一次熱交換器２０４、及び風呂二次熱交換器２０５は、燃焼室８内に設けられる。風呂戻り管２０１は、浴槽９と風呂二次熱交換器２０５の入口との間に接続される。ポンプ２０７は、風呂戻り管２０１の途中に設けられる。風呂一次熱交換器２０４は、風呂バーナ２０３からの燃焼排気中の主に顕熱を回収し、風呂二次熱交換器２０５は、風呂バーナ２０３からの燃焼排気中の主に潜熱を回収し、通水を加熱する。風呂往き管２０２は、風呂一次熱交換器２０４の出口と浴槽９の間に接続される。ポンプ２０７の駆動により、浴槽９内の湯水は、風呂戻り管２０１、風呂二次熱交換器２０５、風呂一次熱交換器２０４、風呂往き管２０２の順に流れ、浴槽９と循環加熱回路１２の間を循環する。 The circulation heating circuit 12 includes a bath return pipe 201, a bath going pipe 202, a bath burner 203, a bath primary heat exchanger 204, a bath secondary heat exchanger 205, a hot water supply pipe 206, a pump 207, and the like. The bath burner 203, the bath primary heat exchanger 204, and the bath secondary heat exchanger 205 are provided in the combustion chamber 8. The bath return pipe 201 is connected between the bathtub 9 and the inlet of the bath secondary heat exchanger 205. The pump 207 is provided in the middle of the bath return pipe 201. The bath primary heat exchanger 204 mainly recovers the sensible heat in the combustion exhaust from the bath burner 203, and the bath secondary heat exchanger 205 mainly recovers the latent heat in the combustion exhaust from the bath burner 203. Heat the water flow. The bath going pipe 202 is connected between the outlet of the bath primary heat exchanger 204 and the bathtub 9. By driving the pump 207, the hot water in the bathtub 9 flows in the order of the bath return pipe 201, the bath secondary heat exchanger 205, the bath primary heat exchanger 204, and the bath outbound pipe 202, and is between the bathtub 9 and the circulation heating circuit 12. To circulate.

湯水供給管２０６は、給湯回路１１と循環加熱回路１２の間に設けられ、給湯回路１１から循環加熱回路１２に向けて湯水を供給する。湯水供給管２０６の上流側端部は、縁切り弁ユニット２の後述する接続口５８に接続される。湯水供給管２０６の下流側端部は、風呂戻り管２０１のポンプ２０７よりも上流側に接続される。縁切り弁ユニット２は、湯水供給管２０６に設けられる。縁切り弁ユニット２は、循環加熱回路１２側から給湯回路１１側への湯水の逆流を防止する。 The hot water supply pipe 206 is provided between the hot water supply circuit 11 and the circulation heating circuit 12, and supplies hot water from the hot water supply circuit 11 to the circulation heating circuit 12. The upstream end of the hot water supply pipe 206 is connected to a connection port 58, which will be described later, of the edge cutting valve unit 2. The downstream end of the hot water supply pipe 206 is connected to the upstream side of the pump 207 of the bath return pipe 201. The edge cut valve unit 2 is provided in the hot water supply pipe 206. The edge cut valve unit 2 prevents the backflow of hot water from the circulation heating circuit 12 side to the hot water supply circuit 11 side.

ガスは、ガス接続口３８からガス管７に流入し、燃焼室８内の給湯バーナ１０２と風呂バーナ２０３に夫々供給される。排水口３９からは、オーバーフロー水とドレン水が排出される。オーバーフロー水は、循環加熱回路１２から湯水供給管２０６を介して縁切り弁ユニット２内に逆流した湯水であり、後述するオーバーフロー管１１０を流れ、排水口３９から外部に排出される。ドレン水は、二次熱交換器１０４と風呂二次熱交換器２０５で生成される。
The gas flows into the gas pipe 7 from the gas connection port 38 and is supplied to the hot water supply burner 102 and the bath burner 203 in the combustion chamber 8, respectively. Overflow water and drain water are discharged from the drain port 39. The overflow water is hot water that has flowed back into the edge cut valve unit 2 from the circulation heating circuit 12 via the hot water supply pipe 206, flows through the overflow pipe 110 described later, and is discharged to the outside from the drain port 39. The drain water is generated by the secondary heat exchanger 104 and the bath secondary heat exchanger 205.

図３〜図５を参照し、縁切り弁ユニット２の構造を説明する。縁切り弁ユニット２は、第１ケーシング３に接続される第２ケーシング４、第３ケーシング５、第４ケーシング６（以下纏めて呼ぶ場合は、ケーシング３〜６と呼ぶ）、給湯側逆止弁７０、第１循環側逆止弁７１、第２循環側逆止弁７２、及び縁切り弁７３を備える。ケーシング３〜６は樹脂製である。即ち、縁切り弁ユニット２は、第２ケーシング４、第３ケーシング５、及び第４ケーシング６で構成され、第２ケーシング４と接続される第１ケーシング３は、給湯回路１１の出湯管１０５の下流側の一部を構成する（図２参照）。 The structure of the edge cut valve unit 2 will be described with reference to FIGS. 3 to 5. The edge cut valve unit 2 includes a second casing 4, a third casing 5, a fourth casing 6 (hereinafter collectively referred to as casings 3 to 6) and a hot water supply side check valve 70 connected to the first casing 3. , A first circulation side check valve 71, a second circulation side check valve 72, and an edge cutting valve 73. Casings 3 to 6 are made of resin. That is, the edge cut valve unit 2 is composed of a second casing 4, a third casing 5, and a fourth casing 6, and the first casing 3 connected to the second casing 4 is downstream of the hot water outlet pipe 105 of the hot water supply circuit 11. It constitutes a part of the side (see FIG. 2).

第１ケーシング３は、右側面視略９０°時計回りに傾けた略Ｔ字状に形成され、横方向部３１（図３参照）と縦方向部３２を備える。横方向部３１は、前後方向に延びる略円筒状に形成され、後端部は閉塞される。横方向部３１の前端部には、接続口３５が設けられる。接続口３５は、前方に向かって開口する。横方向部３１の内側には、流路９１が設けられる。流路９１は、接続口３５から後方に向かって延びる。接続口３５には、出湯管１０５（図２参照）の下流側端部が接続される。 The first casing 3 is formed in a substantially T shape tilted clockwise by approximately 90 ° when viewed from the right side, and includes a lateral portion 31 (see FIG. 3) and a vertical portion 32. The lateral portion 31 is formed in a substantially cylindrical shape extending in the front-rear direction, and the rear end portion is closed. A connection port 35 is provided at the front end of the lateral portion 31. The connection port 35 opens toward the front. A flow path 91 is provided inside the lateral portion 31. The flow path 91 extends rearward from the connection port 35. The downstream end of the hot water pipe 105 (see FIG. 2) is connected to the connection port 35.

縦方向部３２は、上下方向に延びる略円筒状に形成される。縦方向部３２の上下方向の略中間部は、横方向部３１の左面の後部と接続する。縦方向部３２の下端部には、給湯接続口３６が設けられる。給湯接続口３６は、下方に向かって開口する。給湯接続口３６は、給湯器１の底部に設けられる。給湯接続口３６には、蛇口につながる配管（図示略）が接続される。縦方向部３２の内側には、流路９２（図４参照）が設けられる。流路９２は、給湯接続口３６から上方に向かって延びる。流路９２は、上下方向の略中間部において、横方向部３１の流路９１の後端部と連通する。 The vertical portion 32 is formed in a substantially cylindrical shape extending in the vertical direction. The substantially intermediate portion in the vertical direction of the vertical portion 32 is connected to the rear portion of the left surface of the lateral portion 31. A hot water supply connection port 36 is provided at the lower end of the vertical portion 32. The hot water supply connection port 36 opens downward. The hot water supply connection port 36 is provided at the bottom of the water heater 1. A pipe (not shown) connected to the faucet is connected to the hot water supply connection port 36. A flow path 92 (see FIG. 4) is provided inside the vertical portion 32. The flow path 92 extends upward from the hot water supply connection port 36. The flow path 92 communicates with the rear end portion of the flow path 91 of the lateral direction portion 31 at a substantially intermediate portion in the vertical direction.

第２ケーシング４は、右側面視略Ｔ字状に形成され、縦方向部４１と横方向部４２を備える。縦方向部４１は、上下方向に延びる略円筒状に形成される。縦方向部４１の下端部は、第１ケーシング３の縦方向部３２の上端部に２つのネジ３０１で固定される。縦方向部４１の内側には、流路９３（図４参照）が設けられる。流路９３は上下方向に延びる。流路９３の上端部には、金属製のフィルタ４４が設けられる。横方向部４２は、前後方向に延びる略円筒状に形成される。縦方向部４１の上端部は、横方向部４２の長手方向の略中間部の下部と接続する。横方向部４２の内側には、流路９４が設けられる。流路９４は前後方向に延びる。流路９４の後端部は、流路９３の上端部と連通する。横方向部４２の後端部には、電磁弁４５が設けられる。電磁弁４５は、電磁石４５１の励磁・非励磁で流路９４を開閉する。流路９４の前端側には、水量センサ４６が設けられる。水量センサ４６は、流路９４を流れる湯水の量を計測する。 The second casing 4 is formed in a substantially T-shape when viewed from the right side, and includes a vertical direction portion 41 and a horizontal direction portion 42. The vertical portion 41 is formed in a substantially cylindrical shape extending in the vertical direction. The lower end of the vertical portion 41 is fixed to the upper end of the vertical portion 32 of the first casing 3 with two screws 301. A flow path 93 (see FIG. 4) is provided inside the vertical portion 41. The flow path 93 extends in the vertical direction. A metal filter 44 is provided at the upper end of the flow path 93. The lateral portion 42 is formed in a substantially cylindrical shape extending in the front-rear direction. The upper end portion of the vertical portion 41 is connected to the lower portion of the substantially intermediate portion in the longitudinal direction of the lateral portion 42. A flow path 94 is provided inside the lateral portion 42. The flow path 94 extends in the front-rear direction. The rear end of the flow path 94 communicates with the upper end of the flow path 93. A solenoid valve 45 is provided at the rear end of the lateral portion 42. The solenoid valve 45 opens and closes the flow path 94 by exciting or not exciting the electromagnet 451. A water amount sensor 46 is provided on the front end side of the flow path 94. The water amount sensor 46 measures the amount of hot water flowing through the flow path 94.

第３ケーシング５は、上側横方向部５１、下側横方向部５２、縦方向部５３、及び連結部５４を備える。上側横方向部５１は、前後方向に延びる略円筒状であり、第２ケーシング４の横方向部４２と同軸上に設けられる。上側横方向部５１の内側には、流路９５（図４参照）が設けられる。流路９５は前後方向に延びる。流路９５は、給湯回路側から湯水が流れる方向の上流側から順に、流路９５Ａ、９５Ｂを備える。流路９５Ａは、流路９５における後述する分岐部９５１から後側部分である。流路９５Ｂは、流路９５における分岐部９５１よりも前側部分である。 The third casing 5 includes an upper lateral portion 51, a lower lateral portion 52, a vertical portion 53, and a connecting portion 54. The upper lateral portion 51 has a substantially cylindrical shape extending in the front-rear direction, and is provided coaxially with the lateral portion 42 of the second casing 4. A flow path 95 (see FIG. 4) is provided inside the upper lateral portion 51. The flow path 95 extends in the front-rear direction. The flow path 95 includes flow paths 95A and 95B in order from the upstream side in the direction in which hot water flows from the hot water supply circuit side. The flow path 95A is a portion rearward from the branch portion 951 described later in the flow path 95. The flow path 95B is a portion in front of the branch portion 951 in the flow path 95.

上側横方向部５１は、後方から前方に向かって順に、小径部５１１、中径部５１２、及び大径部５１３を備える。小径部５１１は、上側横方向部５１の後端部から長手方向の略中間部までの部分を形成する。流路９５Ａは、小径部５１１の内側に位置する。小径部５１１の内壁面の前端側下部には、分岐部９５１が設けられる。分岐部９５１は、流路９５Ａから後述する縦方向部５３の流路９７に分岐する。小径部５１１の後端部は、第２ケーシング４の横方向部４２の前端部に２つのネジ３０２で固定される。 The upper lateral portion 51 includes a small diameter portion 511, a medium diameter portion 512, and a large diameter portion 513 in this order from the rear to the front. The small diameter portion 511 forms a portion from the rear end portion of the upper lateral direction portion 51 to a substantially intermediate portion in the longitudinal direction. The flow path 95A is located inside the small diameter portion 511. A branch portion 951 is provided at the lower portion on the front end side of the inner wall surface of the small diameter portion 511. The branch portion 951 branches from the flow path 95A to the flow path 97 of the vertical direction portion 53, which will be described later. The rear end portion of the small diameter portion 511 is fixed to the front end portion of the lateral portion 42 of the second casing 4 with two screws 302.

大径部５１３は、上側横方向部５１の前端側部分を形成し、小径部５１１の径よりも大きい。大径部５１３の開口する前端部には、閉塞部５７が２つのネジ３０３で固定される。中径部５１２は、小径部５１１と大径部５１３の間の部分を形成する。中径部５１２は、小径部５１１よりも径が大きく、且つ大径部５１３よりも径が小さい。流路９５Ｂは、中径部５１２と大径部５１３の内側に位置する。中径部５１２の内壁面下部には、連通穴９５２が設けられる。流路９５Ｂは、連通穴９５２を介して、後述する連結部５４の連通路５４１の上端部と連通する。 The large diameter portion 513 forms a front end side portion of the upper lateral direction portion 51, and is larger than the diameter of the small diameter portion 511. A closing portion 57 is fixed to the opening front end portion of the large diameter portion 513 with two screws 303. The medium diameter portion 512 forms a portion between the small diameter portion 511 and the large diameter portion 513. The medium diameter portion 512 has a larger diameter than the small diameter portion 511 and has a smaller diameter than the large diameter portion 513. The flow path 95B is located inside the medium diameter portion 512 and the large diameter portion 513. A communication hole 952 is provided in the lower part of the inner wall surface of the medium diameter portion 512. The flow path 95B communicates with the upper end portion of the communication passage 541 of the connecting portion 54, which will be described later, via the communication hole 952.

下側横方向部５２は、上側横方向部５１の下方に配置される。下側横方向部５２は、上側横方向部５１と平行且つ前後方向に延びる略円筒状に形成される。下側横方向部５２の内側には、流路９６が設けられる。流路９６は前後方向に延びる。下側横方向部５２は、後方から前方に向かって順に、小径部５２１及び大径部５２２を備える。小径部５２１は、上側横方向部５１の中径部５１２の下方に配置され、中径部５１２と略同一形状である。大径部５２２は、上側横方向部５１の大径部５１３の下方に配置され、小径部５２１の径よりも大きい。大径部５２２の前端部には、接続口５８が設けられる。接続口５８は、前方に向かって開口する。接続口５８には、循環加熱回路１２側から延びる湯水供給管２０６（図２参照）の上流側端部が接続される。小径部５２１の内壁面上部には、連通穴９６１（図４参照）が設けられる。流路９６は、連通穴９６１を介して、後述する連結部５４の連通路５４１の下端部と連通する。 The lower lateral portion 52 is arranged below the upper lateral portion 51. The lower lateral portion 52 is formed in a substantially cylindrical shape extending parallel to the upper lateral portion 51 and in the front-rear direction. A flow path 96 is provided inside the lower lateral portion 52. The flow path 96 extends in the front-rear direction. The lower lateral portion 52 includes a small diameter portion 521 and a large diameter portion 522 in this order from the rear to the front. The small diameter portion 521 is arranged below the medium diameter portion 512 of the upper lateral direction portion 51 and has substantially the same shape as the medium diameter portion 512. The large-diameter portion 522 is arranged below the large-diameter portion 513 of the upper lateral portion 51, and is larger than the diameter of the small-diameter portion 521. A connection port 58 is provided at the front end of the large diameter portion 522. The connection port 58 opens toward the front. The upstream end of the hot water supply pipe 206 (see FIG. 2) extending from the circulation heating circuit 12 side is connected to the connection port 58. A communication hole 961 (see FIG. 4) is provided in the upper part of the inner wall surface of the small diameter portion 521. The flow path 96 communicates with the lower end of the communication passage 541 of the connecting portion 54, which will be described later, via the communication hole 961.

連結部５４は、上側横方向部５１と下側横方向部５２の間に設けられ、上側横方向部５１と下側横方向部５２を互いに連結する。連結部５４には、上下方向に延びる連通路５４１（図４参照）が設けられる。連通路５４１の上端部は、上側横方向部５１の中径部５１２の内壁部に設けられた連通穴９５２を介して、流路９５Ｂと連通する。連通路５４１の下端部は、下側横方向部５２の小径部５２１の内壁部に設けられた連通穴９６１を介して、流路９６と連通する。 The connecting portion 54 is provided between the upper lateral direction portion 51 and the lower lateral direction portion 52, and connects the upper lateral direction portion 51 and the lower lateral direction portion 52 to each other. The connecting portion 54 is provided with a communication passage 541 (see FIG. 4) extending in the vertical direction. The upper end portion of the communication passage 541 communicates with the flow path 95B through a communication hole 952 provided in the inner wall portion of the middle diameter portion 512 of the upper lateral direction portion 51. The lower end of the communication passage 541 communicates with the flow path 96 through the communication hole 961 provided in the inner wall portion of the small diameter portion 521 of the lower lateral portion 52.

縦方向部５３は、上側横方向部５１の小径部５１１の下部の前側部分から下方向に延び、略円筒状に形成される。縦方向部５３の内側には、流路９７が設けられる。流路９７は、上下方向に延びる。流路９７の上端部は、小径部５１１の内壁部に設けられた分岐部９５１を介して、流路９５Ａと連通する。縦方向部５３の内壁部であって、下側横方向部５２の後端部と相対する位置には、連通穴９７１が設けられる。流路９７は、連通穴９７１を介して、流路９６と連通する。 The vertical portion 53 extends downward from the lower front portion of the small diameter portion 511 of the upper lateral portion 51, and is formed in a substantially cylindrical shape. A flow path 97 is provided inside the vertical portion 53. The flow path 97 extends in the vertical direction. The upper end portion of the flow path 97 communicates with the flow path 95A via a branch portion 951 provided on the inner wall portion of the small diameter portion 511. A communication hole 971 is provided at a position of the inner wall portion of the vertical portion 53 and facing the rear end portion of the lower lateral portion 52. The flow path 97 communicates with the flow path 96 through the communication hole 971.

第４ケーシング６は、縦方向部６１、弁収納部６２、及び蓋部６３を備える。縦方向部６１は、上下方向に延びる略円筒状である。縦方向部６１の内側には、流路９８が設けられる。流路９８は上下方向に延びる。縦方向部６１の下端部には、流路９９が設けられる。流路９９は、流路９８の下端部から右方向に延びる。縦方向部６１の上端部は、第３ケーシング５の縦方向部５３の下端部、及び下側横方向部５２の下部に対して、２つのネジ３０４で固定される。流路９８は、第３ケーシング５の縦方向部５３の流路９７と連通する。 The fourth casing 6 includes a vertical portion 61, a valve accommodating portion 62, and a lid portion 63. The vertical portion 61 has a substantially cylindrical shape extending in the vertical direction. A flow path 98 is provided inside the vertical portion 61. The flow path 98 extends in the vertical direction. A flow path 99 is provided at the lower end of the vertical portion 61. The flow path 99 extends to the right from the lower end of the flow path 98. The upper end of the vertical portion 61 is fixed to the lower end of the vertical portion 53 of the third casing 5 and the lower portion of the lower lateral portion 52 with two screws 304. The flow path 98 communicates with the flow path 97 of the vertical portion 53 of the third casing 5.

弁収納部６２は、縦方向部６１の右側面の下部に一体して設けられる（図４参照）。弁収納部６２は、右側面視時計回りに傾けた略矩形状で且つ、右側面が開口する箱状に形成される。弁収納部６２の内側の左壁面には、連通穴６２１が設けられる。弁収納部６２の内側は、連通穴６２１を介して、流路９９の右端部と連通する。弁収納部６２の前側で且つ斜め下方に向けられた側面には、排水管６３２（図３参照）が前方に突出して設けられる。排水管６３２の内側は、弁収納部６２の内側と連通する。排水管６３２の前端部には、接続口６６が設けられる。接続口６６は前方に向かって開口する。接続口６６には、オーバーフロー管１１０（図２参照）の上流側端部が接続される。オーバーフロー管１１０の下流側端部は、筐体１Ａの底部の排水口３９（図２参照）に接続される。 The valve accommodating portion 62 is integrally provided at the lower part of the right side surface of the vertical portion 61 (see FIG. 4). The valve accommodating portion 62 is formed in a substantially rectangular shape tilted clockwise when viewed from the right side and in a box shape in which the right side is open. A communication hole 621 is provided on the left wall surface inside the valve accommodating portion 62. The inside of the valve accommodating portion 62 communicates with the right end portion of the flow path 99 through the communication hole 621. A drainage pipe 632 (see FIG. 3) is provided so as to project forward on the front side of the valve accommodating portion 62 and on the side surface facing diagonally downward. The inside of the drain pipe 632 communicates with the inside of the valve accommodating portion 62. A connection port 66 is provided at the front end of the drain pipe 632. The connection port 66 opens toward the front. The upstream end of the overflow pipe 110 (see FIG. 2) is connected to the connection port 66. The downstream end of the overflow pipe 110 is connected to a drain port 39 (see FIG. 2) at the bottom of the housing 1A.

蓋部６３は、右側面視略４５°時計回りに傾けた略矩形状に形成され、弁収納部６２の開口する右側面を閉塞するように、４つのネジ３０５で固定される。蓋部６３の略中央部には、円形状の窪み部６３１が設けられる。窪み部６３１は、蓋部６３の左面が右方に向かって窪んで形成される。蓋部６３の右面には、流入管６３３が前方に屈曲して設けられる。流入管６３３の内側は、窪み部６３１の内側と連通する。流入管６３３の前端部には、接続口６７が設けられる。接続口６７は前方に向かって開口する。接続口６７には、給湯回路１１から延びる分岐管１０６（図２参照）の下流側端部が接続する。 The lid portion 63 is formed in a substantially rectangular shape tilted clockwise by approximately 45 ° when viewed from the right side surface, and is fixed by four screws 305 so as to close the opening right side surface of the valve housing portion 62. A circular recess 631 is provided at a substantially central portion of the lid 63. The recessed portion 631 is formed by recessing the left surface of the lid portion 63 toward the right. An inflow pipe 633 is provided on the right surface of the lid portion 63 so as to be bent forward. The inside of the inflow pipe 633 communicates with the inside of the recess 631. A connection port 67 is provided at the front end of the inflow pipe 633. The connection port 67 opens toward the front. A downstream end of a branch pipe 106 (see FIG. 2) extending from the hot water supply circuit 11 is connected to the connection port 67.

給湯側逆止弁７０、第１循環側逆止弁７１、及び第２循環側逆止弁７２は、バネを内部に備える周知の逆止弁である。図３に示すように、給湯側逆止弁７０は、第３ケーシング５の小径部５１１の内側の流路９５Ａにおいて、分岐部９５１よりも後側に設けられる。給湯側逆止弁７０は、流路９５Ａを前方から後方に向かって逆流する湯水をバネ力で遮断する。第１循環側逆止弁７１は、中径部５１２の内側の流路９５Ｂにおいて、連通路５４１の直上に設けられる。第１循環側逆止弁７１は、連通路５４１から流路９５Ｂに向けて逆流する湯水をバネ力で遮断する。第２循環側逆止弁７２は、第３ケーシング５の下側横方向部５２の小径部５２１の内側の流路９６に設けられる。第２循環側逆止弁７２は、流路９６から縦方向部５３の流路９７に向けて逆流する湯水、及び流路９６から連通路５４１に向けて逆流する湯水をバネ力で夫々遮断する。 The hot water supply side check valve 70, the first circulation side check valve 71, and the second circulation side check valve 72 are well-known check valves having a spring inside. As shown in FIG. 3, the hot water supply side check valve 70 is provided behind the branch portion 951 in the flow path 95A inside the small diameter portion 511 of the third casing 5. The hot water supply side check valve 70 shuts off the hot water flowing back from the front to the rear of the flow path 95A by a spring force. The first circulation side check valve 71 is provided directly above the communication passage 541 in the flow path 95B inside the medium diameter portion 512. The first circulation side check valve 71 shuts off the hot water flowing back from the communication passage 541 toward the flow path 95B by a spring force. The second circulation side check valve 72 is provided in the flow path 96 inside the small diameter portion 521 of the lower lateral portion 52 of the third casing 5. The second circulation side check valve 72 uses a spring force to shut off the hot water flowing back from the flow path 96 toward the flow path 97 of the longitudinal portion 53 and the hot water flowing back from the flow path 96 toward the communication passage 541, respectively. ..

縁切り弁７３は、周知のダイヤフラム弁であり、ダイヤフラム膜７３１及びバネ７３２を備える。バネ７３２は、第４ケーシング６の縦方向部６１の下端部に設けられた流路９９の内側に配置される。ダイヤフラム膜７３１は、弁収納部６２の内側に収納され、蓋部６３の窪み部６３１の左面に向けて配置される。縁切り弁７３は、バネ７３２のバネ力により常時開弁方向に付勢される。給湯回路１１から延びる分岐管１０６から流入管６３３（図３参照）を介して、窪み部６３１の内側に水が流入すると（図３に示す矢印Ｄ参照）、ダイヤフラム膜７３１に対して背圧がかかる。ダイヤフラム膜７３１は水の背圧を受けてバネ７３２を押し下げる。故に縁切り弁７３は、バネ７３２のバネ力に抗して閉弁方向に付勢されて閉じる。 The edge cutting valve 73 is a well-known diaphragm valve, and includes a diaphragm film 731 and a spring 732. The spring 732 is arranged inside the flow path 99 provided at the lower end of the vertical portion 61 of the fourth casing 6. The diaphragm film 731 is housed inside the valve accommodating portion 62, and is arranged toward the left surface of the recessed portion 631 of the lid portion 63. The edge cutting valve 73 is always urged in the valve opening direction by the spring force of the spring 732. When water flows into the recess 631 from the branch pipe 106 extending from the hot water supply circuit 11 via the inflow pipe 633 (see FIG. 3) (see arrow D shown in FIG. 3), back pressure is applied to the diaphragm film 731. It takes. The diaphragm film 731 receives the back pressure of water and pushes down the spring 732. Therefore, the edge cutting valve 73 is urged and closed in the valve closing direction against the spring force of the spring 732.

図３〜図５を参照し、縁切り弁ユニット１０における湯水の流れを説明する。先ず、給湯回路１１から供給される湯水を循環加熱回路１２に供給する場合について説明する。給湯器１の制御部（図示略）は、第２ケーシング４の電磁石を励磁し、電磁弁４５を開放する。給湯回路１１から出湯管１０５を介して流れる湯水は、接続口３５から第１ケーシング３の流路９１に流入し（図３に示す矢印Ａ参照）、流路９２、９３に沿って流れる（図４に示す矢印Ｆ参照）。電磁弁４５は開いているので、湯水は、フィルタ４４を通過し、第２ケーシング４の流路９４に流入する。湯水は、流路９４を前方に流れ、第３ケーシング５の流路９５Ａに流入し、給湯側逆止弁７０を通過する。湯水は、流路９５Ａを前方に流れ、一部の湯水は、分岐部９５１において分岐し、縦方向部５３の流路９７を下方に流れる。残りの湯水は、流路９５Ａを前方に流れ、流路９５Ｂに流入する。流路９５Ｂを前方に流れる湯水は、第１循環側逆止弁７１を通過し、連通穴９５２を介して連結部５４の連通路５４１に流入する。湯水は、連通路５４１を下方に流れる。 The flow of hot water in the edge cut valve unit 10 will be described with reference to FIGS. 3 to 5. First, a case where hot water supplied from the hot water supply circuit 11 is supplied to the circulation heating circuit 12 will be described. The control unit (not shown) of the water heater 1 excites the electromagnet of the second casing 4 and opens the solenoid valve 45. The hot water flowing from the hot water supply circuit 11 through the hot water outlet pipe 105 flows into the flow path 91 of the first casing 3 from the connection port 35 (see arrow A shown in FIG. 3), and flows along the flow paths 92 and 93 (FIG. 3). See arrow F shown in 4). Since the solenoid valve 45 is open, hot water passes through the filter 44 and flows into the flow path 94 of the second casing 4. The hot water flows forward through the flow path 94, flows into the flow path 95A of the third casing 5, and passes through the hot water supply side check valve 70. The hot water flows forward in the flow path 95A, and a part of the hot water branches at the branch portion 951 and flows downward in the flow path 97 in the vertical direction portion 53. The remaining hot water flows forward in the flow path 95A and flows into the flow path 95B. The hot water flowing forward through the flow path 95B passes through the first circulation side check valve 71 and flows into the communication passage 541 of the connecting portion 54 through the communication hole 952. Hot water flows downward through the passage 541.

流路９７を下方に流れた湯水は、第４ケーシング６の縦方向部６１の流路９８、９９を流れ、弁収納部６２の内側に流入する。上記の通り、縁切り弁７３は、給湯回路１１からの水の背圧を受けてバネ力に抗して閉弁方向に付勢されているので、排水管６３２に向かう流路は、縁切り弁７３によって遮断される。よって、流路９７を下方に流れる湯水は、連通穴９７１を介して、下側横方向部５２の流路９６に流入する。湯水は流路９６を前方に流れ、第２循環側逆止弁７２を通過する（図３に示す矢印Ｃ参照）。このようにして、湯水は接続口５８から湯水供給管２０６（図２参照）を介して循環加熱回路１２側に供給される。 The hot water that has flowed downward through the flow path 97 flows through the flow paths 98 and 99 of the vertical portion 61 of the fourth casing 6 and flows into the inside of the valve accommodating portion 62. As described above, since the edge cut valve 73 receives the back pressure of water from the hot water supply circuit 11 and is urged in the valve closing direction against the spring force, the flow path toward the drain pipe 632 is the edge cut valve 73. Is blocked by. Therefore, the hot water flowing downward through the flow path 97 flows into the flow path 96 of the lower lateral portion 52 through the communication hole 971. Hot water flows forward through the flow path 96 and passes through the second circulation side check valve 72 (see arrow C shown in FIG. 3). In this way, hot water is supplied from the connection port 58 to the circulation heating circuit 12 side via the hot water supply pipe 206 (see FIG. 2).

次に、循環加熱回路１２側から給湯回路１１側に向けて湯水が逆流した場合について説明する。例えば、循環加熱回路１２側の圧力が、給湯回路１１側の圧力よりもある程度高まった場合、縁切り弁７３におけるバネ力が給湯回路側の背圧に打ち勝つ。故に、縁切り弁７３はバネ力により開放される。循環加熱回路１２側の圧力が高まった場合、循環加熱回路１２内の湯水が湯水供給管２０６を介して、接続口５８から流路９６に流れ込み、後方に向けて逆流する場合がある。流路９６には、第２循環側逆止弁７２が設けられているので、流路９６を逆流した湯水は、第２循環側逆止弁７２によって遮断される。 Next, a case where hot water flows backward from the circulation heating circuit 12 side toward the hot water supply circuit 11 side will be described. For example, when the pressure on the circulation heating circuit 12 side is higher than the pressure on the hot water supply circuit 11 side to some extent, the spring force in the edge cutting valve 73 overcomes the back pressure on the hot water supply circuit side. Therefore, the edge cut valve 73 is opened by the spring force. When the pressure on the circulation heating circuit 12 side increases, the hot water in the circulation heating circuit 12 may flow into the flow path 96 from the connection port 58 via the hot water supply pipe 206 and flow back toward the rear. Since the second circulation side check valve 72 is provided in the flow path 96, the hot water flowing back through the flow path 96 is shut off by the second circulation side check valve 72.

そして、仮に流路９６を逆流した湯水が第２循環側逆止弁７２を越えたとしても、第３ケーシング５の縦方向部５３の流路９７、及び第４ケーシング６の縦方向部６１の流路９８が共に上下方向に延びている。よって、縁切り弁ユニット２は、第２循環側逆止弁７２を越えた湯水を、流路９７、９８に沿って落下させることができる。流路９７、９８に沿って落下した湯水は、流路９９を右方に流れる。上記の通り、縁切り弁７３は開放されているので、流路９９を流れた湯水は、縁切り弁７３を通過し、排水管６３２からオーバーフロー水として排出される（図３に示す矢印Ｅ参照）。オーバーフロー水は、オーバーフロー管１１０（図２参照）を介して、排水口３９から外部に排出される。 Even if the hot water flowing back through the flow path 96 exceeds the second circulation side check valve 72, the flow path 97 of the vertical portion 53 of the third casing 5 and the vertical portion 61 of the fourth casing 6 Both flow paths 98 extend in the vertical direction. Therefore, the edge cut valve unit 2 can drop hot water that has passed through the second circulation side check valve 72 along the flow paths 97 and 98. Hot water that has fallen along the flow paths 97 and 98 flows to the right in the flow path 99. As described above, since the edge cut valve 73 is open, the hot water flowing through the flow path 99 passes through the edge cut valve 73 and is discharged as overflow water from the drain pipe 632 (see arrow E shown in FIG. 3). The overflow water is discharged to the outside from the drain port 39 via the overflow pipe 110 (see FIG. 2).

そして、循環加熱回路１２側と給湯回路１１側の圧力差がさらに大きくなると、流路９６を逆流した湯水が第２循環側逆止弁７２を勢いよく越えて、その勢いを保ったまま、流路９７、９８に侵入する可能性がある。そこで、縁切り弁ユニット２の第３ケーシング５において、流路９５と流路９６の間には、流路９７及び連通路５４１を介して高低差が形成されている。よって、循環加熱回路１２側の圧力が高まり、流路９６において湯水が第２循環側逆止弁７２を超えたとしても、流路９７及び連通路５４１を夫々上昇するまでの間に、その勢いが弱められる。第２循環側逆止弁７２を越えて流路９７に流入した湯水は、上側横方向部５１の流路９５Ａに達することなく、流路９７、９８に沿って落下する。他方、第２循環側逆止弁７２を越えて連通路５４１に流入した湯水は、流路９５Ｂに達したとしても、第１循環側逆止弁７１によって遮断される。よって、縁切り弁ユニット２は、循環加熱回路１２側から逆流した湯水が給湯回路１１側に侵入するのを確実に防止できる。 Then, when the pressure difference between the circulation heating circuit 12 side and the hot water supply circuit 11 side becomes larger, the hot water flowing back through the flow path 96 vigorously exceeds the second circulation side check valve 72 and flows while maintaining the momentum. There is a possibility of invading roads 97 and 98. Therefore, in the third casing 5 of the edge cut valve unit 2, a height difference is formed between the flow path 95 and the flow path 96 via the flow path 97 and the communication passage 541. Therefore, even if the pressure on the circulation heating circuit 12 side increases and the hot water exceeds the second circulation side check valve 72 in the flow path 96, the momentum is reached until the flow path 97 and the communication passage 541 are raised respectively. Is weakened. The hot water that has flowed into the flow path 97 through the second circulation side check valve 72 falls along the flow paths 97 and 98 without reaching the flow path 95A of the upper lateral portion 51. On the other hand, the hot water that has flowed into the communication passage 541 beyond the second circulation side check valve 72 is shut off by the first circulation side check valve 71 even if it reaches the flow path 95B. Therefore, the edge cut valve unit 2 can surely prevent the hot water flowing back from the circulation heating circuit 12 side from entering the hot water supply circuit 11 side.

図６を参照し、寒冷地において給湯器１を使用する場合に、屋外側の水道管の途中に設置する不凍栓２００の構成を説明する。不凍栓４００は、周知のものである。地中に埋められた水道管４０１の下流側端部には、排水弁４０５の止水側が接続される。排水弁４０５の水抜き側には、立ち上がり管４０２の上流側端部が接続される。排水弁４０５には、水抜きハンドル４０６が設けられる。立ち上がり管４０２は、地面から上方に立ち上がり、その上端部には、吸気弁４０４が設けられる。立ち上がり管４０２は、吸気弁４０４よりも下方の位置において分岐し、その下流側端部は、蛇口４０３に接続される。 With reference to FIG. 6, the configuration of the antifreeze plug 200 installed in the middle of the water pipe on the outdoor side when the water heater 1 is used in a cold region will be described. The antifreeze plug 400 is well known. The water stop side of the drain valve 405 is connected to the downstream end of the water pipe 401 buried in the ground. The upstream end of the rising pipe 402 is connected to the drain side of the drain valve 405. The drain valve 405 is provided with a drain handle 406. The riser pipe 402 rises upward from the ground, and an intake valve 404 is provided at the upper end thereof. The riser pipe 402 branches at a position below the intake valve 404, and its downstream end is connected to the faucet 403.

上記構成の不凍栓４００において、水道管４０１の凍結防止の為に水抜きを行う場合、ユーザは、排水弁４０５の水抜きハンドル４０６を開くと共に、吸気弁４０４を開放する。すると、空気が吸気弁４０４から立ち上がり管４０２に向けて吸引され、立ち上がり管４０２において地中の凍結深度よりも上方の部分における水が、排水弁４０５から地中に排出される。これにより、水道管４０１の破裂を防止できる。 In the antifreeze plug 400 having the above configuration, when draining water to prevent the water pipe 401 from freezing, the user opens the drain handle 406 of the drain valve 405 and also opens the intake valve 404. Then, air is sucked from the intake valve 404 toward the rising pipe 402, and water in the portion of the rising pipe 402 above the freezing depth in the ground is discharged from the drain valve 405 into the ground. As a result, the water pipe 401 can be prevented from bursting.

このような不凍栓４００の蛇口４０３に対して、配管１５０を介して、給湯器１の水入口（図示略）に接続して使用することを想定する。不凍栓２００において、上記のように水抜きを行った場合、給湯器１内の水が給水接続口３７（図２参照）から抜かれる。この場合、図４に示す縁切り弁ユニット２において、縁切り弁７３に対して給湯回路１１側からの背圧が無くなるので、第１循環側逆止弁７１及び第２循環側逆止弁７２の直ぐ上流側にまで空気が充満する。この状態で、循環加熱回路１２側のポンプ２０７が駆動すると、空気が第２循環側逆止弁７２を介して、循環加熱回路１２内に侵入し、エア噛みする可能性がある。これを避ける為、本実施形態の縁切り弁ユニット２においては、第１循環側逆止弁７１及び第２循環側逆止弁７２のバネ力を強くしている。これにより、循環加熱回路１２側のポンプ２０７が駆動しても、第１循環側逆止弁７１及び第２循環側逆止弁７２が開かないようになっている。 It is assumed that the faucet 403 of the antifreeze plug 400 is connected to the water inlet (not shown) of the water heater 1 via the pipe 150 for use. When the antifreeze stopper 200 is drained as described above, the water in the water heater 1 is drained from the water supply connection port 37 (see FIG. 2). In this case, in the edge cut valve unit 2 shown in FIG. 4, the back pressure from the hot water supply circuit 11 side is eliminated from the edge cut valve 73, so that the first circulation side check valve 71 and the second circulation side check valve 72 are immediately located. The air fills up to the upstream side. If the pump 207 on the circulation heating circuit 12 side is driven in this state, air may enter the circulation heating circuit 12 via the second circulation side check valve 72 and bite the air. In order to avoid this, in the edge cut valve unit 2 of the present embodiment, the spring force of the first circulation side check valve 71 and the second circulation side check valve 72 is increased. As a result, even if the pump 207 on the circulation heating circuit 12 side is driven, the first circulation side check valve 71 and the second circulation side check valve 72 are prevented from opening.

そして、上記の通り、縁切り弁ユニット２の第３ケーシング５は、第１循環側逆止弁７１を備える流路９５Ｂと、第２循環側逆止弁７２を備える流路９６とを、上下方向に並列に備えている。流路９５Ｂと流路９６の間には、連通路５４１が設けられる。連通路５４１は、第１循環側逆止弁７１と第２循環側逆止弁７２の間を連通させている。これにより、給湯回路１１側から循環加熱回路１２側に向けて湯水が通過する通過面積を広く確保できるので、湯水通過時の圧損を小さくできる。よって、第１循環側逆止弁７１及び第２循環側逆止弁７２の夫々のバネ力が強く設定されていても、循環加熱回路１２側への湯水の供給量が少なくなるのを防止できる。その結果、給湯器１は、寒冷地においても共通して使用できる。よって、本実施形態は、寒冷地用の給湯器１を別個用意する必要が無くなるので、管理コストを低減できる。 Then, as described above, the third casing 5 of the edge cut valve unit 2 vertically connects the flow path 95B provided with the first circulation side check valve 71 and the flow path 96 provided with the second circulation side check valve 72. It is prepared in parallel with. A communication passage 541 is provided between the flow path 95B and the flow path 96. The communication passage 541 communicates between the first circulation side check valve 71 and the second circulation side check valve 72. As a result, it is possible to secure a wide passage area through which the hot water passes from the hot water supply circuit 11 side toward the circulation heating circuit 12, so that the pressure loss when the hot water passes can be reduced. Therefore, even if the spring forces of the first circulation side check valve 71 and the second circulation side check valve 72 are set to be strong, it is possible to prevent the amount of hot water supplied to the circulation heating circuit 12 side from being reduced. .. As a result, the water heater 1 can be commonly used even in cold regions. Therefore, in the present embodiment, it is not necessary to separately prepare the water heater 1 for cold regions, so that the management cost can be reduced.

さらに、縁切り弁ユニット２では、上記の通り、循環加熱回路１２側と接続する流路９６が、流路９５Ａ、９５Ｂよりも下位位置（低い位置）に設けられる。これにより、循環加熱回路１２側の圧力が相対的に高まるので、仮に循環加熱回路１２内の湯水が第２循環側逆止弁７２を越えたとしても、流路９５Ａとの高低差により、湯水が流路９５Ａに向かうのを防止できる。これにより、縁切り弁ユニット２は、循環加熱回路１２側から給湯回路１１側に湯水が逆流するのを、より確実に防止できる。 Further, in the edge cut valve unit 2, as described above, the flow path 96 connected to the circulation heating circuit 12 side is provided at a lower position (lower position) than the flow paths 95A and 95B. As a result, the pressure on the circulation heating circuit 12 side is relatively increased. Therefore, even if the hot water in the circulation heating circuit 12 exceeds the second circulation side check valve 72, the hot water due to the height difference from the flow path 95A Can be prevented from heading toward the flow path 95A. As a result, the edge cut valve unit 2 can more reliably prevent the hot water from flowing back from the circulation heating circuit 12 side to the hot water supply circuit 11 side.

以上説明において、給湯側逆止弁７０は本発明の「第１逆止弁」の一例、第１循環側逆止弁７１は本発明の「第３逆止弁」の一例、第２循環側逆止弁７２は本発明の「第２逆止弁」の一例である。流路９５Ａは本発明の「上流側経路部」の一例、流路９７，９８，９９、及び弁収納部６２は本発明の「排出経路部」の一例、流路９６は本発明の「下流側経路部」の一例、流路９５Ｂは本発明の「並列経路部」の一例である。 In the above description, the hot water supply side check valve 70 is an example of the "first check valve" of the present invention, the first circulation side check valve 71 is an example of the "third check valve" of the present invention, and the second circulation side. The check valve 72 is an example of the "second check valve" of the present invention. The flow path 95A is an example of the "upstream path portion" of the present invention, the flow paths 97, 98, 99, and the valve accommodating portion 62 are examples of the "discharge path portion" of the present invention, and the flow path 96 is the "downstream" of the present invention. An example of the “side path portion” and the flow path 95B are examples of the “parallel path portion” of the present invention.

以上説明したように、上記実施形態の給湯器１は、縁切り弁ユニット２を備える。縁切り弁ユニット２は、給湯回路１１と循環加熱回路１２を接続する湯水供給管２０６に設けられる。縁切り弁ユニット２は、循環加熱回路１２側から給湯回路１１側への湯水の逆流を防止する。縁切り弁ユニット２は、流路９５Ａ、流路９７〜９９、弁収納部６２、及び流路９６を備える。流路９５Ａは、水平方向に沿って設けられ、給湯回路１１側から流れる湯水が案内される。流路９５Ａには、給湯側逆止弁７０が設けられる。給湯側逆止弁７０は、循環加熱回路１２側からの湯水の逆流を防止する。流路９７〜９９及び弁収納部６２は、流路９５Ａと連通する。弁収納部６２には、縁切り弁７３が設けられる。縁切り弁７３は、バネ７３２のバネ力により常時開弁方向に付勢され、給湯回路１１からの背圧を受けてバネ力に抗して閉弁方向に付勢される。流路９６は、水平方向に沿って設けられ、湯水が流れる方向の上流側の端部である上流側端部が、流路９５Ａよりも下位位置で流路９７と連通し、下流側端部が循環加熱回路１２と接続する。流路９６の上流側端部と下流側端部の間には、第２循環側逆止弁７２が設けられる。第２循環側逆止弁７２は、循環加熱回路１２側からの湯水の逆流を防止する。 As described above, the water heater 1 of the above embodiment includes the edge cut valve unit 2. The edge cut valve unit 2 is provided in the hot water supply pipe 206 that connects the hot water supply circuit 11 and the circulation heating circuit 12. The edge cut valve unit 2 prevents the backflow of hot water from the circulation heating circuit 12 side to the hot water supply circuit 11 side. The edge cutting valve unit 2 includes a flow path 95A, flow paths 97 to 99, a valve accommodating portion 62, and a flow path 96. The flow path 95A is provided along the horizontal direction, and the hot water flowing from the hot water supply circuit 11 side is guided. A check valve 70 on the hot water supply side is provided in the flow path 95A. The hot water supply side check valve 70 prevents the backflow of hot water from the circulation heating circuit 12 side. The flow paths 97 to 99 and the valve accommodating portion 62 communicate with the flow path 95A. The valve accommodating portion 62 is provided with an edge cutting valve 73. The edge cutting valve 73 is constantly urged in the valve opening direction by the spring force of the spring 732, and is urged in the valve closing direction against the spring force by receiving the back pressure from the hot water supply circuit 11. The flow path 96 is provided along the horizontal direction, and the upstream end, which is the upstream end in the direction in which hot water flows, communicates with the flow path 97 at a position lower than the flow path 95A, and the downstream end. Connects to the circulation heating circuit 12. A second circulation side check valve 72 is provided between the upstream end and the downstream end of the flow path 96. The second circulation side check valve 72 prevents the backflow of hot water from the circulation heating circuit 12 side.

上記構成によれば、流路９６と流路９５Ａとの間に流路９７を介して高低差が形成される。よって、循環加熱回路１２側の圧力が高まり、仮に湯水が流路９６側の第２循環側逆止弁７２を乗り越えたとしても、流路９７を上昇するまでの間にその勢いが減少される。それ故、湯水は流路９５Ａに達することなく、流路９７〜９９内を下方に落ちるか、仮に流路９５Ａに達したとしても、流路９５Ａの給湯側逆止弁７０を乗り越えることはなく、流路９７〜９９内を下方に落ちる。従って、給湯器１は、縁切り弁ユニット２によって、循環加熱回路１２側の湯水が給湯回路１１側に逆流するのを確実に防止できる。 According to the above configuration, a height difference is formed between the flow path 96 and the flow path 95A via the flow path 97. Therefore, even if the pressure on the circulation heating circuit 12 side increases and the hot water water gets over the second circulation side check valve 72 on the flow path 96 side, the momentum is reduced until the flow path 97 rises. .. Therefore, the hot water does not reach the flow path 95A and falls downward in the flow paths 97 to 99, or even if it reaches the flow path 95A, it does not get over the hot water supply side check valve 70 of the flow path 95A. , Fall down in the flow paths 97-99. Therefore, the water heater 1 can surely prevent the hot water on the circulation heating circuit 12 side from flowing back to the hot water supply circuit 11 side by the edge cut valve unit 2.

なお、本発明は上記実施形態に限定されるものではなく、種々の変更が可能である。例えば、縁切り弁ユニット２において、流路９５Ｂ、第１循環側逆止弁７１、及び連通路５４１は省略してもよい。 The present invention is not limited to the above embodiment, and various modifications can be made. For example, in the edge cut valve unit 2, the flow path 95B, the first circulation side check valve 71, and the communication passage 541 may be omitted.

縁切り弁ユニット２は、流路９５Ｂと流路９６を互いに上下方向に並列に設けているが、並列であればよく、例えば左右方向（水平方向）に並列に設けてもよい。また、流路９５Ｂの上流側端部は、流路９５Ａの下流側端部と同一高さ位置で接続しているが、例えば、流路９５Ｂの上流側端部は、流路９５Ａよりも低い位置で、且つ流路９６よりも高い位置で、流路９７と接続してもよい。 In the edge cutting valve unit 2, the flow path 95B and the flow path 96 are provided in parallel in the vertical direction with respect to each other, but they may be provided in parallel, for example, in parallel in the left-right direction (horizontal direction). Further, the upstream end of the flow path 95B is connected at the same height as the downstream end of the flow path 95A, but for example, the upstream end of the flow path 95B is lower than the flow path 95A. It may be connected to the flow path 97 at a position and at a position higher than the flow path 96.

縁切り弁ユニット２は、３つのケーシング４〜６を備え、互いにネジ３０２〜３０５で固定して構成されるが、ケーシングの数、及び固定方法については、自由に変更可能である。また、接続口３５、給湯接続口３６、接続口５８、排水管６３２、及び流入管６３３の夫々の開口する方向については、上記実施形態に限らず、自由に変更可能である。 The edge cut valve unit 2 includes three casings 4 to 6 and is configured to be fixed to each other with screws 302 to 305, but the number of casings and the fixing method can be freely changed. Further, the opening directions of the connection port 35, the hot water supply connection port 36, the connection port 58, the drain pipe 632, and the inflow pipe 633 are not limited to the above-described embodiment, and can be freely changed.

縁切り弁ユニット２の流路９７は上下方向に沿って設けられるが、下方に向かって延びていれば、全体的に又は部分的に斜めでもよく、折れ曲がっていてもよい。 The flow path 97 of the edge cut valve unit 2 is provided along the vertical direction, but as long as it extends downward, it may be slanted in whole or partially, or it may be bent.

１給湯器
２縁切り弁ユニット
１１給湯回路
１２循環加熱回路
６２弁収納部
７０給湯側逆止弁
７１第１循環側逆止弁
７２第２循環側逆止弁
７３縁切り弁
９５Ａ、９５Ｂ、９８、９９流路
２０６湯水供給管
５４１連通路 1 Water heater 2 Edge cut valve unit 11 Hot water supply circuit 12 Circulation heating circuit 62 Valve storage 70 Hot water supply side check valve 71 1st circulation side check valve 72 2nd circulation side check valve 73 Edge cut valve 95A, 95B, 98, 99 Flow path 206 Hot water supply pipe 541 consecutive passage

Claims

In a water heater provided with an edge-cutting valve unit for preventing backflow of hot water from the circulation heating circuit side to the hot water supply circuit side in a pipeline connecting the hot water supply circuit and the circulation heating circuit.
The edge cut valve unit is
An upstream path portion provided along the horizontal direction, in which hot water is guided from the hot water supply circuit side and a first check valve is provided to prevent backflow of hot water from the circulation heating circuit side.
An edge-cutting valve that communicates with the upstream path portion and is constantly urged in the valve opening direction by a spring force, and receives back pressure from the hot water supply circuit and is urged in the valve closing direction against the spring force. The discharge path section provided and
The upstream end, which is provided along the horizontal direction and is the upstream end in the direction in which hot water flows, communicates with the discharge path at a position lower than the upstream path, and communicates with the upstream end. A second check valve that connects the downstream end on the opposite side to the circulation heating circuit and prevents backflow of hot water from the circulation heating circuit side between the upstream end and the downstream end. A water heater characterized by being provided with a downstream path portion provided with a water heater.

The water heater according to claim 1, wherein the discharge path portion is provided along the vertical direction.

The upstream end, which is provided in parallel with the downstream path and is the upstream end in the direction in which hot water flows, is at a height position between the upstream path and the downstream path, and is discharged. Communicating with the path portion, the downstream end portion on the side opposite to the upstream side end portion communicates with the second check valve of the downstream side route portion via the communication passage, and the upstream side end portion and the downstream side end portion. The water heater according to claim 1 or 2, wherein a parallel path portion provided with a third check valve for preventing backflow of hot water from the circulation heating circuit side is provided between the side end portions.