JP5067080B2 - Backflow prevention valve, backflow prevention device having the same, hot water supply device and hot water supply system - Google Patents

Backflow prevention valve, backflow prevention device having the same, hot water supply device and hot water supply system Download PDF

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JP5067080B2
JP5067080B2 JP2007224764A JP2007224764A JP5067080B2 JP 5067080 B2 JP5067080 B2 JP 5067080B2 JP 2007224764 A JP2007224764 A JP 2007224764A JP 2007224764 A JP2007224764 A JP 2007224764A JP 5067080 B2 JP5067080 B2 JP 5067080B2
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valve
water supply
hot water
pipe
backflow prevention
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JP2009058021A (en
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繁男 杉江
亮二 大内
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Noritz Corp
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Description

本発明は、給湯装置の温水を浴槽に通水する管路に設けられ、給湯装置に対する給水圧が低下しても浴槽の戻り水が給湯管に逆流するのを防止する逆流防止装置に好適に使用される逆流防止弁と、これを有する前記逆流防止装置、給湯装置及び給湯システムに関する。   The present invention is suitable for a backflow prevention device that is provided in a conduit for passing hot water of a hot water supply apparatus to the bathtub and prevents the return water of the bathtub from flowing back to the hot water supply pipe even when the supply water pressure to the hot water supply apparatus decreases. The present invention relates to a backflow prevention valve used, and the backflow prevention device, the hot water supply device and the hot water supply system having the same.

例えば、風呂の給湯システムは、給水管に給水された上水を給湯装置で加熱し、この加熱された湯を給湯管から風呂の浴槽に注湯するようになっている。この場合、集合住宅や給水圧が低い住宅では、ポンプで上水を汲み上げて各戸に給水するが、給水元の停電や断水のために給水側が負圧になると、その負圧で浴槽からの戻り水が吸引され、給湯装置の給湯管まで浴槽の戻り水が逆流することがある。   For example, in a hot water supply system for a bath, hot water supplied to a water supply pipe is heated by a hot water supply apparatus, and the heated hot water is poured into a bath tub from the hot water supply pipe. In this case, in apartment houses and houses with low water supply pressure, water is pumped up and supplied to each house, but if the water supply side becomes negative due to a power outage or water outage at the water supply source, the negative pressure returns from the bathtub. Water may be sucked in and the return water from the bathtub may flow back to the hot water supply pipe of the hot water supply device.

このような浴槽からの逆流を防止するために、給湯装置の給湯管と浴槽の間の管路に逆流防止装置が設けられている。
従来の逆流防止装置は、給湯管の温水を浴槽に通水する管路と、浴槽への通水のみを許容するように管路に直列に設けられた一対の逆止弁とを備えており、基本的には、この両逆止弁によって給湯管への逆止機能を確保している。 In order to prevent such a backflow from the bathtub, a backflow prevention device is provided in a pipe line between the hot water supply pipe of the hot water supply apparatus and the bathtub.
A conventional backflow prevention device includes a pipe for passing hot water from a hot water supply pipe to a bathtub and a pair of check valves provided in series in the pipe so as to allow only water to pass through the bathtub. Basically, the check function for the hot water supply pipe is secured by the both check valves.

しかし、上記逆止弁が異物の噛み込み等によって完全に閉じていないときは、逆流防止装置の上流側の一次圧（以下、給水圧ということがある。）が負圧になったり、逆流防止弁の上流側の一次圧が下流側の二次圧（以下、通水圧ということがある。）を下回ったりすると、浴槽の戻り水がその水頭圧によって逆止弁を通過し、給湯管に逆流してくることがある。
そこで、従来の逆流防止装置では、上記管路における両逆止弁間の通水部分に、給湯管への給水圧をパイロット圧として当該通水部分に対する大気開放と逆流水排水を行う逆流防止弁が設けられている。 However, when the check valve is not completely closed due to foreign matter or the like, the primary pressure upstream of the backflow prevention device (hereinafter sometimes referred to as feed water pressure) becomes negative or prevents backflow. When the primary pressure upstream of the valve falls below the downstream secondary pressure (hereinafter sometimes referred to as water flow pressure), the return water from the bathtub passes through the check valve due to the water head pressure and flows back into the hot water supply pipe. Sometimes
Therefore, in the conventional backflow prevention device, the backflow prevention valve that performs air release and backflow water drainage to the water flow portion using the feed water pressure to the hot water supply pipe as a pilot pressure in the water flow portion between the check valves in the pipe. Is provided.

この場合、給水圧が減少すると逆流防止弁が開弁し、これによって通水部分が大気開放されるとともに、その通水部分に引き込まれた逆流水が外部に排出されるので、浴槽からの戻り水が給湯管に逆流するのが防止される（特許文献１参照）。
このように、従来の逆流防止装置では、比較的高位置の浴槽に残り湯があり、かつ、逆止弁が十分に機能してない場合に、水道の断水や停電による汲み上げポンプの停止のために給水側が負圧状態になっても、逆止弁間の通水部分に設けた逆流防止弁が開き、浴槽からの戻り水を外部に排水できるようになっている。
特開２００３−２５４６０４号公報 In this case, when the water supply pressure decreases, the backflow prevention valve opens, thereby opening the water flow part to the atmosphere and discharging the backflow water drawn into the water flow part to the outside. Water is prevented from flowing back into the hot water supply pipe (see Patent Document 1).
As described above, in the conventional backflow prevention device, when there is remaining hot water in a relatively high tub and the check valve is not functioning sufficiently, the pumping pump is stopped due to water outage or power failure. Even when the water supply side is in a negative pressure state, the check valve provided in the water flow portion between the check valves is opened so that the return water from the bathtub can be drained to the outside.
JP 2003-254604 A

この種の逆流防止装置では、当該装置の上流側の一次圧が負圧になることで逆流防止弁が開き、この逆流防止弁の開放通路から空気を吸い込んで負圧を破壊するようになっているので、その空気の吸い込み時に外部に排出すべき逆流水も一緒に吸い込まれる可能性がある。
このように、上記逆流防止弁は、通水部分に対する大気開放（負圧破壊）機能と逆流水排水機能という、相反する機能を担っているので、従来の逆流防止装置では、逆流防止弁による排水量が不十分になり、給湯管に逆流が生じる可能性が残されている。 In this type of backflow prevention device, the backflow prevention valve opens when the primary pressure upstream of the device becomes negative, and the negative pressure is destroyed by sucking air from the open passage of this backflow prevention valve. Therefore, backflow water that should be discharged to the outside when the air is sucked may be sucked together.
As described above, the backflow prevention valve has the contradictory functions of opening the atmosphere (negative pressure destruction) to the water flow portion and the backflow water drainage function. Therefore, in the conventional backflow prevention device, the amount of drainage by the backflow prevention valve Is insufficient, and there is a possibility that a back flow will occur in the hot water supply pipe.

上記不都合を解消する方策として、逆流防止弁の口径をよりも大きくして、通水部分に対する大気開放と逆流水排水を行う逆流防止弁の開放通路をできるだけ大きく取ることが考えられる。
しかし、上記開放通路を大きくすると、弁座の口径やこれを開閉する弁体及びダイヤフラムのシール径も大きくなることから、背圧室に負荷される給水圧によって弁体のシール部に作用する荷重も大きくなって当該シール部が劣化しやすくなり、逆流防止弁の耐久性が低下するという新たな課題が生じる。 As a measure for solving the above inconvenience, it is conceivable that the diameter of the backflow prevention valve is made larger so that the open passage of the backflow prevention valve for opening the atmosphere to the water flow portion and backflow water drainage is made as large as possible.
However, if the opening passage is enlarged, the diameter of the valve seat and the seal diameter of the valve body and the diaphragm for opening and closing the valve seat also increase. Therefore, the load acting on the seal portion of the valve body due to the supply water pressure applied to the back pressure chamber Becomes larger and the seal portion is likely to deteriorate, resulting in a new problem that the durability of the check valve is lowered.

本発明は、このような実情に鑑み、弁体のシール部に作用する荷重を増大させずに開放通路の大口径化を図れるようにして、大気開放と逆流水排水をより確実に行える耐久性に優れた逆流防止弁を提供することを目的とする。   In view of such circumstances, the present invention is capable of increasing the diameter of the open passage without increasing the load acting on the seal portion of the valve body, and is capable of more reliably opening the atmosphere and backflow water drainage. An object of the present invention is to provide an excellent backflow prevention valve.

本発明の逆流防止弁は、内部に弁座を有する弁筒体と、前記弁座に接離自在に当接するように前記弁筒体内に収納された弁体と、この弁体を前記弁筒体の軸心方向に移動自在に支持するダイヤフラムとを備え、前記弁筒体の内部でかつ前記ダイヤフラムの背面側に形成された背圧室に給水圧が負荷される逆流防止弁において、前記背圧室の給水圧によって発生する前記弁体に対する前記弁座への押し付け力を軽減する荷重軽減手段が設けられていることを特徴とする（請求項１）。   The backflow prevention valve of the present invention includes a valve body having a valve seat therein, a valve body housed in the valve body so as to be in contact with and away from the valve seat, and the valve body as the valve cylinder. A backflow prevention valve in which supply water pressure is applied to a back pressure chamber formed inside the valve cylinder and on the back side of the diaphragm. A load reducing means for reducing a pressing force against the valve seat against the valve body generated by a water supply pressure of a pressure chamber is provided (Claim 1).

上記逆流防止弁によれば、荷重軽減手段が、背圧室の給水圧（一次圧）によって発生する弁体に対する弁座への押し付け力を軽減するので、弁体のシール部に作用する荷重を増大させないで逆流防止弁の開放通路を大口径化することができる。
このため、大口径化された開放通路によって大気開放と逆流水排水をより確実に行えるとともに、弁体のシール部に作用する荷重が増大しないので、弁体のシール部の劣化も発生し難く、逆流防止弁の耐久性も維持することができる。 According to the backflow prevention valve, the load reducing means reduces the pressing force on the valve seat against the valve body generated by the water supply pressure (primary pressure) of the back pressure chamber, so that the load acting on the seal portion of the valve body is reduced. The opening diameter of the check valve can be increased without increasing the diameter.
For this reason, the open passage with a large diameter can be more reliably opened to the atmosphere and backflow water drainage, and since the load acting on the seal portion of the valve body does not increase, it is difficult for the seal portion of the valve body to deteriorate, The durability of the backflow prevention valve can also be maintained.

本発明の逆流防止弁において、前記荷重軽減手段は、具体的には、前記弁体の背面側から突設された当該弁体よりも小径の第二の弁体と、この第二の弁体を前記弁筒体の軸心方向に移動自在に支持する第二のダイヤフラムと、この第二のダイヤフラムを前記第二の弁体に固定する受圧板とから構成することができる。
この場合、前記第二の弁体を、前記背圧室の背面壁に形成された貫通孔に貫通させ、前記第二のダイヤフラムを、前記貫通孔を密閉した状態で前記背圧室の背面壁に取り付けるようにすればよい（請求項１）。 In the backflow prevention valve of the present invention, the load reducing means specifically includes a second valve body having a smaller diameter than the valve body protruding from the back side of the valve body, and the second valve body. Can be configured by a second diaphragm that is movably supported in the axial direction of the valve cylinder, and a pressure receiving plate that fixes the second diaphragm to the second valve body.
In this case, the second valve body is passed through a through hole formed in the back wall of the back pressure chamber, and the back wall of the back pressure chamber is sealed with the second diaphragm sealed. (Claim 1 ).

上記構造の荷重軽減手段によれば、弁体の背面側に第二の弁体が突設されているので、当該第二の弁体を設けた分だけ第一の弁体に対し逆向きの受圧力が生じ、ダイヤフラムの背面側に形成された背圧室に給水圧（一次圧）が負荷された場合に、その給水圧（一次圧）によって発生する弁体に対する弁座への押し付け力が軽減される。   According to the load reducing means having the above structure, since the second valve body protrudes on the back side of the valve body, the amount of the second valve body provided is opposite to the first valve body. When receiving pressure is generated and a water supply pressure (primary pressure) is applied to the back pressure chamber formed on the back side of the diaphragm, the pressing force on the valve seat against the valve element generated by the water supply pressure (primary pressure) is reduced. It is reduced.

また、本発明の逆流防止弁において、前記弁体の開時に前記ダイヤフラムの正面側の大気開放を行う複数の開放口を、前記弁筒体に対して上下方向に離間して独立して形成することが好ましい（請求項２）。
この場合、背面室の給水圧（一次圧）が低下して弁体が開いた場合に、より上方の開放口が主として大気開放機能を担い、より下方の開放口が主として逆流水排水機能を担うことになり、大気開放と逆流水排水がそれぞれ複数の開放口に役割分担される。このため、大気開放と逆流水排水の各機能をより確実に達成でき、逆流防止弁の信頼性を高めることができる。なお、弁筒体に設ける開放口は少なくとも二つあればよいが、三つ以上設けるものにしてもよい。 Further, in the check valve according to the present invention, a plurality of open ports for releasing the atmosphere on the front side of the diaphragm when the valve body is opened are formed separately from each other in the vertical direction with respect to the valve body. (Claim 2 ).
In this case, when the water supply pressure (primary pressure) in the back chamber is lowered and the valve body is opened, the upper opening mainly serves the air opening function, and the lower opening mainly serves the backflow water drainage function. As a result, the air release and the backflow water drainage are each assigned to a plurality of openings. For this reason, each function of air release and backflow water drainage can be achieved more reliably, and the reliability of the backflow prevention valve can be enhanced. Note that at least two open ports may be provided in the valve cylinder, but three or more may be provided.

本発明の逆流防止装置は、給湯管の温水を浴槽に通水する管路と、前記浴槽への通水のみを許容するように前記管路に直列に設けられた一対の逆止弁と、前記管路における前記両逆止弁間の通水部分に設けられた上記逆流防止弁とを備えた逆流防止装置であって、前記逆流防止弁により前記給湯管への給水圧をパイロット圧として前記通水部分に対する大気開放と逆流水排水を行うことを特徴とする（請求項３）。 The backflow prevention device of the present invention includes a pipe for passing hot water of a hot water supply pipe to the bathtub, a pair of check valves provided in series in the pipe so as to allow only water to the bathtub, A backflow prevention device provided with a backflow prevention valve provided in a water flow portion between the check valves in the pipeline, wherein the backflow prevention valve uses the water supply pressure to the hot water supply pipe as a pilot pressure. The open air to the water flow part and the backflow water drainage are performed (Claim 3 ).

上記逆流防止装置によれば、管路における前逆止弁間の通水部分に対する大気開放と逆流水排水を行う逆流防止弁として、前記した本発明の逆流防止弁を採用しているので、大口径化された逆流防止弁の開放通路によって大気開放と逆流水排水をより確実に行えるとともに、弁体のシール部に作用する荷重が増大しないので、弁体のシール部の劣化も発生し難く、逆流防止弁の耐久性を維持することができる。
従って、大気開放と逆流水排水を確実に行え、かつ、耐久性に優れた逆流防止装置を得ることができる。 According to the backflow prevention device, the backflow prevention valve of the present invention described above is employed as a backflow prevention valve that performs atmospheric release and backflow water drainage on the water flow portion between the front check valves in the pipe. The open passage of the backflow prevention valve that has been calibrated allows air release and backflow water drainage to be performed more reliably, and the load acting on the seal portion of the valve body does not increase, so it is difficult for the seal portion of the valve body to deteriorate, The durability of the backflow prevention valve can be maintained.
Therefore, it is possible to obtain a backflow prevention device that can reliably release the atmosphere and drain the backflow water and is excellent in durability.

本発明の逆流防止装置において、前記通水部分は、その通水方向上流側が上方に位置する上下方向に長い縦向き管により構成されていることが好ましい（請求項４）。
この場合、管路における両逆止弁間の通水部分が、その通水方向上流側が上方に位置する上下方向に長い縦向き管よりなるので、一次側（給湯管側）の逆止弁が縦向き管の上側に位置し、かつ、二次側（浴槽側）の逆止弁が縦向き管の下側に位置することになる。 In backflow prevention device of the present invention, the water flow portion, it is preferred that water passing upstream side is composed of a long vertical tube vertically positioned above (claim 4).
In this case, since the water flow portion between the check valves in the pipe line is a vertically long pipe with the upstream side in the water flow direction positioned upward, the check valve on the primary side (the hot water supply pipe side) The check valve on the secondary side (tub side) is located on the upper side of the vertical pipe, and is located on the lower side of the vertical pipe.

このため、給水圧が低下して通水部分（縦向き管）が負圧になったり二次圧よりも低圧になったりした場合に、浴槽の戻り水が縦向き管の下部に位置する二次側の逆止弁を超えて引っ張られたとしても、一次側の逆止弁が当該縦向き管の上側に位置することから、その縦向き管に侵入した逆流水が一次側の逆止弁を超えて給水管側への逆流が進行する可能性が低くなり、逆流防止機能をより向上することができる。   For this reason, when the water supply pressure decreases and the water flow portion (vertical pipe) becomes negative pressure or lower than the secondary pressure, the return water of the bathtub is located at the lower part of the vertical pipe. Even if the primary side check valve is pulled beyond the secondary side check valve, the primary side check valve is located above the vertical pipe. Therefore, the possibility that the reverse flow to the water supply pipe side proceeds is reduced, and the reverse flow prevention function can be further improved.

本発明の給湯装置は、上水が給水される給水管と、この給水管に給水された上水を加熱する熱交換器と、この熱交換器で加熱された温水を外部に給湯する給湯管と、この給湯管と浴槽との間に介装された上記の逆流防止装置とを備えていることを特徴とする（請求項５）。
また、本発明の給湯システムは、上記給湯装置と、前記給湯管からの温水が前記逆流防止装置を介して給湯される浴槽とを備えていることを特徴とする（請求項６）。
上記給湯装置及び給湯システムによれば、前記給湯管と前記浴槽の間に上記逆流防止装置が介装されているので、給湯管に対する給水圧（一次圧）が低下したときに、通水部分に対する大気開放と逆流水排水が、本発明の大口径化された逆流防止弁によって行われる。このため、一対の逆止弁間の通水部分に対する大気開放と逆流水排水がより確実に達成され、給水システムにおける逆流防止機能の信頼性を高めることができる。 The hot water supply apparatus of the present invention includes a water supply pipe for supplying clean water, a heat exchanger for heating the clean water supplied to the water supply pipe, and a hot water supply pipe for supplying hot water heated by the heat exchanger to the outside. When, characterized in that it comprises a interposed the above backflow prevention device between the hot water supply pipe and tub (claim 5).
In addition, the hot water supply system of the present invention includes the hot water supply device and a bathtub in which hot water from the hot water supply pipe is supplied via the backflow prevention device (Claim 6 ).
According to the hot water supply device and the hot water supply system, since the backflow prevention device is interposed between the hot water supply pipe and the bathtub, when the water supply pressure (primary pressure) with respect to the hot water supply pipe decreases, Opening to the atmosphere and backflow water drainage are performed by the large-diameter backflow prevention valve of the present invention. For this reason, the open air to the water flow portion between the pair of check valves and the backflow water drainage are more reliably achieved, and the reliability of the backflow prevention function in the water supply system can be enhanced.

以上の通り、本発明によれば、弁体のシール部に作用する荷重を増大させずに開放通路の大口径化を図ることができるので、大気開放と逆流水排水をより確実に行える耐久性に優れた逆流防止弁を得ることができる。   As described above, according to the present invention, since it is possible to increase the diameter of the open passage without increasing the load acting on the seal portion of the valve body, it is possible to more reliably open the atmosphere and backflow water drainage. It is possible to obtain an excellent backflow prevention valve.

以下、図面を参照しつつ、本発明の実施形態を説明する。
図１〜図６は、本発明を採用した逆流防止装置の一例を示し、図７は、その逆流防止装置を適用した風呂の給湯システムを示している。
〔給湯システム〕
図７に示すように、本実施形態の給湯システム１は、ガス給湯器２よりなる給湯装置と、その給湯器２に給排水可能に接続された風呂の浴槽３とを備えている。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIGS. 1-6 shows an example of the backflow prevention apparatus which employ | adopted this invention, FIG. 7 has shown the hot water supply system of the bath to which the backflow prevention apparatus is applied.
[Hot water system]
As shown in FIG. 7, the hot water supply system 1 of the present embodiment includes a hot water supply device including a gas water heater 2 and a bath tub 3 connected to the hot water heater 2 so as to be able to supply and drain water.

ガス給湯器２は、給湯室等に設置可能な筐体５と、この筐体５内に設けられた熱交換器６とを備え、筐体５には、上水道の給水口７と、燃料ガスの吸気部８と、加熱湯をキッチンの蛇口等に供給する第一給湯口９と、浴槽２への給湯を行う第二給湯口１０と、浴槽２からの戻り湯を受け入れる戻り口１１とが設けられている。
上記吸気部８は筐体５内の吸気管１２に繋がっており、この吸気管１２は、元ガス電磁弁１３とガス比例弁１４を介して熱交換器６内の燃焼管１５に接続されている。 The gas water heater 2 includes a housing 5 that can be installed in a hot water supply room and the like, and a heat exchanger 6 provided in the housing 5, and the housing 5 includes a water supply inlet 7, a fuel gas, and the like. A first hot water supply port 9 for supplying hot water to a kitchen faucet, etc., a second hot water supply port 10 for supplying hot water to the bathtub 2, and a return port 11 for receiving return hot water from the bathtub 2. Is provided.
The intake section 8 is connected to an intake pipe 12 in the housing 5, and the intake pipe 12 is connected to a combustion pipe 15 in the heat exchanger 6 via an original gas electromagnetic valve 13 and a gas proportional valve 14. Yes.

前記給水口７は筐体２内の給水管１７に繋がっており、この給水管１７は、給水量センサ１８を介して熱交換器６内の給湯熱交換部１９に接続されている。給湯熱交換部１９の下流側と第一給湯口９の間は給湯管２０で繋がっており、この給湯管２０には、給湯水量調整弁２１が設けられている。
また、給湯管２０と給水管１７はバイパス管２２で繋がっており、このバイバス管２２にはバイパス水量調整弁２３が設けられている。 The water supply port 7 is connected to a water supply pipe 17 in the housing 2, and the water supply pipe 17 is connected to a hot water supply heat exchange unit 19 in the heat exchanger 6 through a water supply amount sensor 18. The downstream side of the hot water supply heat exchanging section 19 and the first hot water supply port 9 are connected by a hot water supply pipe 20, and a hot water supply amount adjustment valve 21 is provided in the hot water supply pipe 20.
The hot water supply pipe 20 and the water supply pipe 17 are connected by a bypass pipe 22, and the bypass pipe 22 is provided with a bypass water amount adjustment valve 23.

前記第二給湯口１０は風呂往き管２４に繋がっており、戻り口１１は風呂戻り管２５に繋がっている。この風呂の往き管２４と戻り管２５のうち、往き管２４は熱交換器６内の風呂熱交換部２６の出口側に繋がっており、この風呂熱交換部２６の入口側は吐出管２８に繋がっている。
この吐出管２８は、筐体５内に設けられた風呂ポンプ２９の吐出側に接続され、戻り管２５は当該風呂ポンプ２９の吸い込み側に接続されている。 The second hot water supply port 10 is connected to a bath outlet tube 24, and the return port 11 is connected to a bath return tube 25. Of the bath outlet pipe 24 and return pipe 25, the outlet pipe 24 is connected to the outlet side of the bath heat exchanging section 26 in the heat exchanger 6, and the inlet side of the bath heat exchanging section 26 is connected to the discharge pipe 28. It is connected.
The discharge pipe 28 is connected to the discharge side of a bath pump 29 provided in the housing 5, and the return pipe 25 is connected to the suction side of the bath pump 29.

ガス給湯器２の給湯管２０は、水量調整弁２１の下流側の部分に分岐管３０を備えており、この分岐管３０は、後述する逆流防止装置３１の入口側に接続されている。また、逆流防止装置３１の出口側には浴槽２への注湯管３２が接続され、この注湯管３２は、前記戻り管２５とともに風呂ポンプ２９の吸い込み側に通じている。
本実施形態の逆流防止装置３１は、その上流側（給湯管２０側：一次側ということがある。）から下流側（浴槽３側：二次側ということがある。）へ至る順序で、注湯水量センサ３４と、注湯電磁弁３５と、通水方向に直列に並ぶ一対の逆止弁３６，３７と、この両逆止弁３６，３７の間に配置された複数の逆流防止弁３８とを備えている。 The hot water supply pipe 20 of the gas water heater 2 includes a branch pipe 30 at a portion downstream of the water amount adjustment valve 21, and the branch pipe 30 is connected to an inlet side of a backflow prevention device 31 described later. A pouring pipe 32 to the bathtub 2 is connected to the outlet side of the backflow prevention device 31, and the pouring pipe 32 communicates with the return pipe 25 to the suction side of the bath pump 29.
The backflow prevention device 31 of the present embodiment is ordered in the order from the upstream side (hot water pipe 20 side: sometimes referred to as primary side) to the downstream side (sometimes referred to as bathtub 3 side: sometimes referred to as secondary side). A hot water amount sensor 34, a pouring electromagnetic valve 35, a pair of check valves 36 and 37 arranged in series in the direction of water flow, and a plurality of check valves 38 disposed between the check valves 36 and 37. And.

上記一対の逆止弁３６，３７は、一次側の第一逆止弁３６と、二次側の第二逆止弁３６とからなり、浴槽３の戻り管２５からの戻り水が給湯管２０に逆流するのを防止する逆止機能を有する。
しかし、これらの逆止弁３６，３７が、異物の噛み込み等が原因で完全に閉じていないときは、給水管２０への給水圧（上流側の一次圧）Ｐ１が負圧になったり、逆止弁３６，３７間の通水圧（下流側の二次圧）Ｐ２よりも低くなると、浴槽３の戻り水がその水頭圧により逆止弁３６，３７を通過し、給湯管２０に逆流してくることがある。 The pair of check valves 36 and 37 includes a primary check valve 36 on the primary side and a second check valve 36 on the secondary side, and the return water from the return pipe 25 of the bathtub 3 is supplied with the hot water supply pipe 20. It has a check function to prevent backflow.
However, when these check valves 36 and 37 are not completely closed due to foreign matter biting or the like, the feed water pressure (upstream primary pressure) P1 to the feed water pipe 20 becomes negative pressure, When the water flow pressure between the check valves 36 and 37 (secondary pressure on the downstream side) P2 becomes lower, the return water of the bathtub 3 passes through the check valves 36 and 37 due to the head pressure and flows back to the hot water supply pipe 20. May come.

そこで、本実施形態の逆流防止装置３１では、給湯管２０の温水を浴槽３に通水する管路における両逆止弁３６，３７間の通水部分に上記逆流防止弁３８が設けられ、この弁３８によって給湯管２０への逆流現象をより確実に防止するようにしている。
すなわち、この逆流防止弁３８は、給水管１７の給水圧Ｐ１をパイロット圧として、両逆止弁３６，３７間の通水部分に対する大気開放（負圧破壊）と逆流水排水を行うように作動するものであり、逆流防止弁３８の背圧側は前記給水管１７に接続され、かつ、逆流防止弁３８の出口側は大気開放された排水管３９に繋がっている。 Therefore, in the backflow prevention device 31 of the present embodiment, the backflow prevention valve 38 is provided in the water passage portion between the check valves 36 and 37 in the pipe for passing the hot water of the hot water supply pipe 20 to the bathtub 3. The valve 38 prevents the reverse flow phenomenon to the hot water supply pipe 20 more reliably.
In other words, the backflow prevention valve 38 operates so as to perform open air (negative pressure destruction) and backflow water drainage to the water flow portion between the check valves 36 and 37 using the feed water pressure P1 of the feed water pipe 17 as a pilot pressure. The back pressure side of the backflow prevention valve 38 is connected to the water supply pipe 17, and the outlet side of the backflow prevention valve 38 is connected to a drain pipe 39 opened to the atmosphere.

このため、給水管１７の給水圧Ｐ１が低下して負圧になったり、その給水圧Ｐ１が逆止弁３６，３７間の通水部分の通水圧Ｐ２（注湯管３２の管内圧と同じ圧力）よりも低くなったりすると、逆流防止弁３８が作動して、逆止弁３６，３７間の通水部分が大気開放され、当該通水部分の負圧状態が解かれる。
また、これと同時に、戻り管２５からの逆流水が通水部分に侵入してきても、その逆流水は逆流防止弁３８の出口（後述する開放口６９）から排出管３９に排出されるようになっている。 For this reason, the feed water pressure P1 of the feed water pipe 17 is reduced to a negative pressure, or the feed water pressure P1 is the same as the water pressure P2 in the water passage portion between the check valves 36 and 37 (the same pressure as the pipe inner pressure of the pouring pipe 32). If the pressure is lower than (pressure), the backflow prevention valve 38 is activated, the water passage portion between the check valves 36 and 37 is opened to the atmosphere, and the negative pressure state of the water passage portion is released.
At the same time, even if the backflow water from the return pipe 25 enters the water flow portion, the backflow water is discharged from the outlet of the backflow prevention valve 38 (an opening 69 described later) to the discharge pipe 39. It has become.

上記構成の給湯システム１において、給水管１７に給水された上流水は、給水量センサ１８を通り、その一部が給湯熱交換部１９で加熱されて湯になり、他の一部がバイパス管２２を通って給湯熱交換部１９から出てきた湯と混合される。
このさい、バイパス水量調整弁２３がバイパスする水流量を制御して湯水の混合比が変わり、出湯の温度制御が行われる。所望の温度に制御された湯は、給湯水量調整弁２１により給湯水量が制御され、第一給湯口９から外部に給湯される。 In the hot water supply system 1 configured as described above, the upstream water supplied to the water supply pipe 17 passes through the water supply amount sensor 18, a part of which is heated by the hot water supply heat exchanging unit 19 to become hot water, and the other part is a bypass pipe. 22 is mixed with hot water coming out of the hot water supply heat exchanging section 19 through 22.
At this time, the water flow rate bypassed by the bypass water amount adjusting valve 23 is controlled to change the mixing ratio of hot water and the temperature of the hot water is controlled. The amount of hot water controlled to a desired temperature is controlled by the hot water supply amount adjustment valve 21 and is supplied from the first hot water supply port 9 to the outside.

一方、浴槽３に湯張りを行う場合には、逆流防止装置３１の注湯電磁弁３５を開くことにより、分岐管３０の湯が注湯水量センサ３４と逆止弁３６，３７を介して浴槽３へ供給される。
このさい、逆流防止装置３１の逆流防止弁３８は、パイロット圧として上水道の給水圧Ｐ１を受けて閉弁方向に付勢されている。そして、逆流防止装置３１の下流側の注湯管３２の通水圧Ｐ２は上記給水圧Ｐ１よりも低いので、これらの差圧で逆流防止弁３８は閉状態になっている。 On the other hand, when filling the bathtub 3 with hot water, the hot water electromagnetic valve 35 of the backflow prevention device 31 is opened so that the hot water in the branch pipe 30 passes through the hot water sensor 34 and the check valves 36 and 37. 3 is supplied.
At this time, the backflow prevention valve 38 of the backflow prevention device 31 receives the water supply pressure P1 of the water supply as a pilot pressure and is urged in the valve closing direction. And since the water flow pressure P2 of the pouring pipe 32 on the downstream side of the backflow prevention device 31 is lower than the feed water pressure P1, the backflow prevention valve 38 is closed by these differential pressures.

他方、断水等によって給水管１７に負圧が発生すると、逆流防止弁３８が給水圧Ｐ１の低下に対応して開かれる。
これにより、一対の逆止弁３６，３７間の通水部分が大気開放され、給水管１７に生じた負圧がその通水部分で破壊されるとともに、その通水部分内の水が逆流防止弁３８の出口から排出管３９を通って外部に排出され、給湯管２０への逆流現象がより確実に防止される。 On the other hand, when negative pressure is generated in the water supply pipe 17 due to water breakage or the like, the backflow prevention valve 38 is opened in response to a decrease in the water supply pressure P1.
Thereby, the water flow portion between the pair of check valves 36 and 37 is opened to the atmosphere, the negative pressure generated in the water supply pipe 17 is destroyed at the water flow portion, and the water in the water flow portion is prevented from flowing back. The outlet of the valve 38 is discharged to the outside through the discharge pipe 39, and the backflow phenomenon to the hot water supply pipe 20 is more reliably prevented.

〔逆流防止装置及び逆流防止弁〕
次に、図１〜図６を参照しつつ、本実施形態の逆流防止装置３１の具体的構成について説明する。
図１〜図６に示すように、本実施形態の逆流防止装置３１は、前記一対の逆止弁３６，３７（図５及び図６参照）及び逆流防止弁３８を管路中に一体に組み込んだバルブユニットよりなり、給湯管２０から分岐する前記分岐管３０が接続される第一管路４１と、浴槽３側へ給湯するための前記注湯管３２が接続される第二管路４２とを備えている。 [Backflow prevention device and backflow prevention valve]
Next, a specific configuration of the backflow prevention device 31 of the present embodiment will be described with reference to FIGS.
As shown in FIGS. 1 to 6, the backflow prevention device 31 of the present embodiment incorporates the pair of check valves 36 and 37 (see FIGS. 5 and 6) and the backflow prevention valve 38 integrally in a pipeline. A first pipe line 41 connected to the branch pipe 30 branched from the hot water supply pipe 20, and a second pipe line connected to the pouring pipe 32 for supplying hot water to the bathtub 3 side. It has.

第一管路４１は、両端開放の水平管４３と、この水平管４３の中央部から下方に延びる縦向き管４４とを一体に備えたＴ字管よりなり、この縦向き管４４の下端部には分岐管３０との接続部４５が形成されている。
他方、第二管路４２は、第一管路４１の水平管４３の下流側端部（図５の右側端部）に接続された片側開放の水平管４６と、この水平管４６から下方に延びる縦向き管４７とを一体に備えており、この縦向き管４７の下端部には前記注湯管３２との接続部４８が形成されている。 The first pipe 41 is composed of a T-shaped pipe integrally provided with a horizontal pipe 43 having both ends open and a vertical pipe 44 extending downward from the central portion of the horizontal pipe 43, and a lower end portion of the vertical pipe 44. A connecting portion 45 for connection with the branch pipe 30 is formed.
On the other hand, the second pipe 42 is connected to the downstream end (the right end in FIG. 5) of the horizontal pipe 43 of the first pipe 41, and is open downward from the horizontal pipe 46. A vertically extending pipe 47 is integrally provided, and a connecting portion 48 to the pouring pipe 32 is formed at the lower end of the vertically oriented pipe 47.

第一管路４１の水平管４３と第二管路４２の水平管４６は、それらの縦向き管４４，４７の軸心方向が上下方向でかつ互いに平行状態となるように接続されている。
このため、第一管路４１の縦向き管４４に流入した温水は、この縦向き管４４を下から上に流れ、各水平管４３，４６を通って、第二管路４２の縦向き管４７を上から下に流れるようになっている。 The horizontal pipe 43 of the first pipe 41 and the horizontal pipe 46 of the second pipe 42 are connected so that the axial directions of the vertical pipes 44 and 47 are vertical and parallel to each other.
For this reason, the hot water that has flowed into the vertical pipe 44 of the first pipe 41 flows from the bottom to the top of the vertical pipe 44, passes through the horizontal pipes 43 and 46, and passes through the vertical pipe 44 of the second pipe 42. 47 flows from top to bottom.

図６に示すように、第一管路４１の縦向き管４４の内部には、前記注湯水量センサ３４が設けられている。
この注湯水量センサ３４は、通過する水に旋回流を与える整流器５０と、縦向き管４７の中心線回りに回転する着磁された羽根車５１と、この羽根車５１に近接して管路壁内に埋設された磁気センサ（図示せず）とからなり、羽根車５１の回転数をカウントすることで浴槽３への注湯量を計測するものである。 As shown in FIG. 6, the pouring water amount sensor 34 is provided inside the vertical pipe 44 of the first pipe line 41.
The pouring water amount sensor 34 includes a rectifier 50 that gives a swirling flow to the passing water, a magnetized impeller 51 that rotates around the center line of the vertical pipe 47, and a pipe line that is close to the impeller 51. It consists of a magnetic sensor (not shown) embedded in the wall, and measures the amount of pouring water into the bathtub 3 by counting the number of rotations of the impeller 51.

また、第一管路４１の水平管４３の上流側端部（図５の左側端部）には、前記注湯電磁弁３５が接続されている。
この注湯電磁弁３５は、水平管４３と一体形成された筒状の弁座５２と、ダイヤフラム５３によって支持された弁体５４と、この弁体５４の中央部に接続されたソレノイドのプランジャ５５と、このプランジャ５５を常時弁座５２側に付勢するコイルばね５６と含むパイロット弁よりなる。このため、プランジャ５５を磁力で開弁方向（図５の左側）に移動させて弁体５４を弁座５２から引き離すことにより、第一管路４１の縦向き管４４に至った温水が水平管４３に流入するようになっている。 In addition, the pouring electromagnetic valve 35 is connected to an upstream end portion (left end portion in FIG. 5) of the horizontal pipe 43 of the first conduit 41.
The pouring electromagnetic valve 35 includes a cylindrical valve seat 52 integrally formed with the horizontal pipe 43, a valve body 54 supported by a diaphragm 53, and a solenoid plunger 55 connected to the central portion of the valve body 54. And a pilot valve including a coil spring 56 that constantly urges the plunger 55 toward the valve seat 52. For this reason, the plunger 55 is moved magnetically in the valve opening direction (left side in FIG. 5) and the valve body 54 is pulled away from the valve seat 52, so that the hot water that has reached the vertical pipe 44 of the first pipeline 41 becomes horizontal pipe. 43 flows in.

前記一対の逆止弁３６，３７のうち、上流側に位置する第一逆止弁３６は、第一及び第二管路４１，４２の水平管４３，４６の接続部内に設けられ、下流側に位置する第二逆止弁３７は、第二管路４２の縦向き管４７の下端部内に設けられている。
このため、本実施形態の逆流防止装置３１では、第二管路４２における両逆止弁間３６，３７の通水部分が、通水方向上流側が上方に位置する、上下方向に長い当該第二管路４２の縦向き管４７により構成されている。 The first check valve 36 located on the upstream side of the pair of check valves 36 and 37 is provided in the connection portion of the horizontal pipes 43 and 46 of the first and second pipe lines 41 and 42, and is located downstream. The second check valve 37 located at is provided in the lower end portion of the vertical pipe 47 of the second pipe 42.
For this reason, in the backflow prevention device 31 of the present embodiment, the second water passage portion between the check valves 36 and 37 in the second pipe line 42 is long in the vertical direction with the upstream side in the water flow direction positioned upward. The pipe 42 is constituted by a vertical pipe 47.

図６に示すように、第一逆止弁３６は、第一管路４１の水平管４３の接続部内に収納された筒状の弁座５７と、この弁座５７に下流側（図６の右側）から当接して通水方向に進退自在に配置された弁体５８と、この弁体５８を弁座５７側に付勢するコイルばね５９とを有する。
また、第二逆止弁３７は、上記第一逆止弁３６と同一構造のものであり、第二管路４２の縦向き管４７の下端部内に収納された筒状の弁座５７と、この弁座５７に下流側（図６の下側）から当接して通水方向に進退自在に配置された弁体５８と、この弁体５８を弁座５７側に付勢するコイルばね５９とを有する。 As shown in FIG. 6, the first check valve 36 includes a cylindrical valve seat 57 housed in the connection portion of the horizontal pipe 43 of the first pipe 41 and a downstream side (see FIG. 6). The valve body 58 is disposed in contact with the right side) so as to be able to advance and retreat in the direction of water flow, and a coil spring 59 that urges the valve body 58 toward the valve seat 57 side.
The second check valve 37 has the same structure as the first check valve 36, and has a cylindrical valve seat 57 housed in the lower end portion of the vertical pipe 47 of the second conduit 42, A valve body 58 disposed in contact with the valve seat 57 from the downstream side (lower side in FIG. 6) so as to be able to advance and retreat in the direction of water flow, and a coil spring 59 for biasing the valve body 58 toward the valve seat 57 Have

本実施形態の逆流防止装置３１では、大口径化された逆流防止弁３８が第二管路４２の縦向き管４７の中途部に接続されている。
図５に示すように、この逆流防止弁３８は、内部に弁座６２を有する弁筒体６１と、弁座６２に接離自在に当接するように弁筒体６１内に収納された第一弁体６３と、この第一弁体６３を弁筒体６１の軸心方向に移動自在に支持するメインダイヤフラム６４と、第一弁体６３の背面側に突設された第二弁体６５と、この第二弁体６５を弁筒体６１の軸心方向に移動自在に支持するサブダイヤフラム６６とを備えている。 In the backflow prevention device 31 of this embodiment, the backflow prevention valve 38 having a large diameter is connected to the middle portion of the vertical pipe 47 of the second pipe 42.
As shown in FIG. 5, the backflow prevention valve 38 includes a valve cylinder 61 having a valve seat 62 therein, and a first cylinder accommodated in the valve cylinder 61 so as to come into contact with and separate from the valve seat 62. A valve body 63, a main diaphragm 64 that supports the first valve body 63 movably in the axial direction of the valve body 61, and a second valve body 65 that projects from the back side of the first valve body 63. And a sub-diaphragm 66 that supports the second valve body 65 movably in the axial direction of the valve cylinder 61.

上記弁筒体６１は、縦向き管４７から水平方向に一体に突設されかつその縦向き管４７よりも大径の外筒６７と、この外筒６７の開口部に接続されたケーシング６８と、このケーシング６８の外端面に接続された弁蓋体６９とからなる。
弁座６２は、弁筒体６１の外筒６７よりも短い筒状部材よりなり、この外筒６７と同軸心状となるように、縦向き管４７から水平方向に一体に突設されている。 The valve cylinder 61 protrudes integrally from the vertical pipe 47 in the horizontal direction and has a larger diameter outer cylinder 67 than the vertical pipe 47, and a casing 68 connected to the opening of the outer cylinder 67. And a valve lid 69 connected to the outer end surface of the casing 68.
The valve seat 62 is made of a cylindrical member shorter than the outer cylinder 67 of the valve cylinder 61, and is protruded integrally from the vertical pipe 47 in the horizontal direction so as to be coaxial with the outer cylinder 67. .

外筒６７の開口部には、外周が矩形状のフランジ部７０が形成されていて、このフランジ部７０に、同じく矩形状の前記ケーシング６８及び弁蓋体６９をその順に接合してねじ止めすることにより、フランジ部７０、ケーシング６８及び弁蓋体６９の三者が三層構造に一体化されている。
第一弁体６３は、外筒６７の内周面より小径でかつ弁座６２の外周面より大径の短円柱部材よりなり、先端面（図５の左側面）の中心部に取付突起７１を一体に備えている。 A flange portion 70 having a rectangular outer periphery is formed at the opening of the outer cylinder 67, and the casing 68 and the valve lid body 69, which are also rectangular, are joined to the flange portion 70 in that order and screwed. Thus, the three members of the flange portion 70, the casing 68, and the valve lid body 69 are integrated into a three-layer structure.
The first valve body 63 is made of a short cylindrical member having a smaller diameter than the inner peripheral surface of the outer cylinder 67 and a larger diameter than the outer peripheral surface of the valve seat 62, and a mounting protrusion 71 at the center of the distal end surface (left side surface in FIG. 5). Is integrated.

メインダイヤフラム６４の中央部には取付孔が形成され、この取付孔に第一弁体６３の取付突起７１を抜け止め状態で挿通することにより、メインダイヤフラム６４の円板部分が第一弁体６３の先端面に取り付けられている。
また、メインダイヤフラム６４の外周縁部は、フランジ部７０とケーシング６８との間に挟持されることにより、弁筒体６１の内周面に固定されている。 A mounting hole is formed at the center of the main diaphragm 64, and the mounting protrusion 71 of the first valve body 63 is inserted into the mounting hole in a state of preventing the main diaphragm 64 from being detached, so that the disc portion of the main diaphragm 64 is inserted into the first valve body 63. It is attached to the front end surface.
Further, the outer peripheral edge portion of the main diaphragm 64 is fixed to the inner peripheral surface of the valve body 61 by being sandwiched between the flange portion 70 and the casing 68.

弁筒体６１の内部空間のうち、メインダイヤフラム６４の背面側（弁座６２の反対側）のケーシング６８内の空間は、第一弁体６３を弁座６２に密着させるための背圧室７２とされ、この背圧室７２に給水管１７の給水圧Ｐ１を導入する導入口７３（図３参照）がケーシング６８に形成されている。
また、メインダイヤフラム６４の正面側（弁座６２側）にある、弁座６２の外周側の筒状の開放通路７４は、開弁時に吸気と排水が行われるスペースであって、この開放通路７４は、外筒６７に形成された上下一対の開放口７５，７５（図３及び図６参照）と連通している。これらの開放口７５，７５は、弁筒体６１の外筒６７に対して上下方向に離間して独立して形成されている。 Of the internal space of the valve cylinder 61, the space in the casing 68 on the back side of the main diaphragm 64 (opposite the valve seat 62) is a back pressure chamber 72 for bringing the first valve body 63 into close contact with the valve seat 62. An inlet 73 (see FIG. 3) for introducing the feed water pressure P1 of the feed water pipe 17 into the back pressure chamber 72 is formed in the casing 68.
A cylindrical open passage 74 on the outer peripheral side of the valve seat 62 on the front side (the valve seat 62 side) of the main diaphragm 64 is a space where intake and drainage are performed when the valve is opened. Is in communication with a pair of upper and lower open ports 75, 75 (see FIGS. 3 and 6) formed in the outer cylinder 67. These open ports 75 and 75 are formed separately from each other in the vertical direction with respect to the outer cylinder 67 of the valve cylinder 61.

そして、上記導入口７３には給水管１７から分岐するパイロット管が接続され、上下の各開放口７５，７５には排出管３９が接続されるようになっている。
図５を参照して、第二弁体６５は、第一弁体６３よりも小径の短円柱部材よりなり、第一弁体６３の背面中央部から同軸心状に突設されている。この第二弁体６５は、その外端面（図５の右側面）の中心部に取付ねじ部７６を一体に備えている。この取付ねじ部７６は、サブダイヤフラム６６とこの外面側に重なる受圧板８０の中心部を貫通している。受圧板８０の中心部は取付ねじ部７６に螺合するナット部になっており、当該受圧板８０を締め付け方向に回動することにより、サブダイヤフラム６６が第二弁体６５に一体化されている。
内部に背圧室７２を形成するケーシング６８の背面壁７７には、第二弁体６５よりも大径の貫通孔７８が形成され、この貫通孔７８に、第二弁体６５の突出端部が貫通状に挿通されている。 A pilot pipe branched from the water supply pipe 17 is connected to the introduction port 73, and a discharge pipe 39 is connected to the upper and lower open ports 75, 75.
Referring to FIG. 5, the second valve body 65 is made of a short cylindrical member having a smaller diameter than the first valve body 63, and protrudes coaxially from the center of the back surface of the first valve body 63. The second valve body 65 is integrally provided with a mounting screw portion 76 at the center of its outer end surface (right side surface in FIG. 5). The mounting screw portion 76 passes through the center portion of the pressure receiving plate 80 overlapping the sub diaphragm 66 and the outer surface side thereof. The central portion of the pressure receiving plate 80 is a nut portion that is screwed into the mounting screw portion 76. By rotating the pressure receiving plate 80 in the tightening direction, the sub diaphragm 66 is integrated with the second valve body 65. Yes.
A through-hole 78 having a diameter larger than that of the second valve body 65 is formed in the back wall 77 of the casing 68 that forms the back pressure chamber 72 therein, and the protruding end portion of the second valve body 65 is formed in the through-hole 78. Is inserted in a penetrating manner.

サブダイヤフラム６６の中央部には取付孔が形成され、この取付孔に第二弁体６５の取付突起７６を抜け止め状態で挿通することにより、サブダイヤフラム６６の円板部分が第二弁体６５の外端面に取り付けられている。
また、サブイヤフラム６６の外周縁部は、ケーシング６８の背面壁７７と弁蓋体６９の間に挟持させることによって当該背面壁７７に固定されており、このさい、サブダイヤフラム６６によって背面壁７７の貫通孔７８が密閉されるようになっている。 An attachment hole is formed in the center of the sub diaphragm 66, and the attachment protrusion 76 of the second valve element 65 is inserted into the attachment hole in a state of preventing the attachment, so that the disc portion of the sub diaphragm 66 is inserted into the second valve element 65. It is attached to the outer end face.
Further, the outer peripheral edge portion of the sub diaphragm 66 is fixed to the rear wall 77 by being sandwiched between the rear wall 77 of the casing 68 and the valve lid body 69. At this time, the sub diaphragm 66 penetrates the rear wall 77. The hole 78 is sealed.

上記構成に係る逆流防止装置３１において、注湯電磁弁３５が通電されていない時は、そのプランジャ５５が弁体５４を弁座５２に押し付けており、当該電磁弁３５が閉弁状態にある。従って、この場合には浴槽３への給湯は遮断されている。
このさい、逆流防止弁３８の背圧室７２には給水圧Ｐ１がかかっているため、その第一弁体６３は弁座６２に当接しており、逆流防止弁３８の開放通路７４はいずれも閉塞されている。 In the backflow prevention device 31 according to the above configuration, when the pouring electromagnetic valve 35 is not energized, the plunger 55 presses the valve body 54 against the valve seat 52, and the electromagnetic valve 35 is in a closed state. Therefore, in this case, the hot water supply to the bathtub 3 is blocked.
At this time, since the water supply pressure P1 is applied to the back pressure chamber 72 of the backflow prevention valve 38, the first valve body 63 is in contact with the valve seat 62, and any of the open passages 74 of the backflow prevention valve 38 is provided. It is blocked.

従って、注湯電磁弁３５が通電されると、そのプランジャ５５が磁力で吸引されて弁体５４が開き、分岐管３０から第一管路４１を経由して第二管路４２に温水が流入し、その温水が第一及び第二逆止弁３６，３７を通って浴槽３への給湯が開始される。
一方、給水管１７の断水等によって給水圧Ｐ１が低下した場合は、第一及び第二逆止弁３６，３７が閉じ、第二管路４２の縦向き管４７に設けられている逆流防止弁３８の背圧室７２の圧力が低下し、第一弁体６３が弁座６２から離れる。 Therefore, when the hot water solenoid valve 35 is energized, the plunger 55 is attracted by the magnetic force, the valve body 54 is opened, and hot water flows from the branch pipe 30 through the first pipe 41 into the second pipe 42. Then, the hot water passes through the first and second check valves 36 and 37 and hot water supply to the bathtub 3 is started.
On the other hand, when the water supply pressure P1 decreases due to water cut off of the water supply pipe 17 or the like, the first and second check valves 36 and 37 are closed, and the check valve provided in the vertical pipe 47 of the second pipe line 42 is closed. The pressure in the 38 back pressure chambers 72 decreases, and the first valve body 63 moves away from the valve seat 62.

これにより、逆流防止弁３８の開放通路７４が開放口７５と連通して大気開放され、第一及び第二逆止弁３６，３７の間の通水部分である縦向き管４７の負圧が破壊されるとともに、その縦向き管４７内に溜まっていた水が開放口７５を通って排出管３９から排出される。
このとき、第二逆止弁３７が完全に閉塞しないという事態が発生すると、浴槽３からの戻り水が第二逆止弁３７を通過して逆流が比較的大量に発生するが、その逆流水は、主として下側の開放口７５から排出されるため、給湯管２０まで逆流することがない。 As a result, the open passage 74 of the check valve 38 communicates with the open port 75 and is opened to the atmosphere, and the negative pressure of the vertical pipe 47 that is a water passage portion between the first and second check valves 36 and 37 is reduced. At the same time, the water accumulated in the vertical pipe 47 is discharged from the discharge pipe 39 through the opening 75.
At this time, if a situation occurs in which the second check valve 37 is not completely closed, the return water from the bathtub 3 passes through the second check valve 37 and a relatively large amount of backflow is generated. Is discharged mainly from the lower opening 75, and therefore does not flow back to the hot water supply pipe 20.

そして、本実施形態の逆流防止弁３８によれば、第一弁体６３の背面側に第二弁体６４が突設されているので、当該第二弁体６４を設けた分だけ第一弁体６３に対し逆向きの受圧力が生じ、メインダイヤフラム６４の背面側に形成された背圧室７２に給水圧Ｐ１が負荷された場合に、その給水圧Ｐ１によって発生する第一弁体６３に対する弁座６２への押し付け力が軽減される。   And according to the backflow prevention valve 38 of this embodiment, since the 2nd valve body 64 is protrudingly provided by the back side of the 1st valve body 63, it is the 1st valve by the part which provided the said 2nd valve body 64 When a receiving pressure in the opposite direction is generated with respect to the body 63 and the feed water pressure P1 is applied to the back pressure chamber 72 formed on the back side of the main diaphragm 64, the first valve body 63 generated by the feed water pressure P1 is applied. The pressing force to the valve seat 62 is reduced.

すなわち、第一弁体６３の背面側に突設された第二弁体６５と、これを移動自在に支持するサブダイヤフラム６６により、背圧室７２の給水圧Ｐ１によって発生する第一弁体６３に対する弁座６２への押し付け力を軽減する荷重軽減手段７９が構成されており、これにより、第一弁体６３のシール部（弁座６２に対する当接部分）に作用する荷重を増大させることなく、逆流防止弁３８の開放通路７４が大口径化されている。
このため、大口径化された開放通路７４によって大気開放と逆流水排水がより確実に行われるとともに、第一弁体６３のシール部に作用する荷重が増大しないので、第一弁体６３のシール部の劣化も発生し難く、逆流防止弁３８の耐久性が維持される。 That is, the first valve body 63 generated by the water supply pressure P1 in the back pressure chamber 72 is constituted by the second valve body 65 projecting from the back side of the first valve body 63 and the sub-diaphragm 66 that supports the second valve body movably. The load reducing means 79 is configured to reduce the pressing force against the valve seat 62 against the valve seat 62, thereby increasing the load acting on the seal portion of the first valve body 63 (the contact portion with respect to the valve seat 62). The open passage 74 of the backflow prevention valve 38 has a large diameter.
For this reason, the open passage 74 having a large diameter allows the air release and the backflow water drainage to be performed more reliably, and the load acting on the seal portion of the first valve body 63 does not increase. Deterioration of the part hardly occurs, and the durability of the backflow prevention valve 38 is maintained.

また、本実施形態の逆流防止装置３１によれば、荷重軽減手段７９が、本来の第一弁体６３の背面側にこれより小径の第二弁体６５を突設し、この第二弁体６５をサブダイヤフラム６６で移動自在に支持する構造になっているので、第二弁体６５及びダイヤフラム６６を設けたことによって逆流防止弁３８の口径が必要以上に肥大化することがなく、逆流防止弁３８をコンパクトに構成できるという利点もある。   Further, according to the backflow prevention device 31 of the present embodiment, the load reducing means 79 projects the second valve body 65 having a smaller diameter on the back side of the original first valve body 63, and this second valve body 65 is configured to be movably supported by the sub-diaphragm 66, so that the second valve body 65 and the diaphragm 66 are provided so that the diameter of the backflow prevention valve 38 is not enlarged more than necessary, thereby preventing backflow. There is also an advantage that the valve 38 can be configured compactly.

更に、本実施形態の逆流防止装置３１によれば、両逆止弁３６，３７間の通水部分（第二管路４２の縦向き管４７）が、その通水方向上流側が上方に位置する上下方向に長い縦向き管よりなるので、一次側（給湯管２０側）の第一逆止弁３６が縦向き管４７の上側に位置し、かつ、二次側（浴槽側）の第二逆止弁３７が当該縦向き管４７の下側に位置するようになっている。
このため、給水圧Ｐ１が低下して縦向き管４７の内部が負圧になったり二次側の通水圧Ｐ２よりも低圧になったりした場合に、浴槽３の戻り水が縦向き管４７の下部に位置する第二逆止弁３７を超えて引っ張られたとしても、第一逆止弁３６が当該縦向き管４７の上側に位置することから、その縦向き管４７に侵入した逆流水が第一逆止弁３６を超えて給水管２０側への逆流が進行する可能性が低くなる。 Furthermore, according to the backflow prevention device 31 of the present embodiment, the water flow portion (vertical pipe 47 of the second pipe line 42) between the check valves 36 and 37 is located on the upstream side in the water flow direction. Since it consists of a vertically long pipe in the vertical direction, the first check valve 36 on the primary side (hot water supply pipe 20 side) is positioned above the vertical pipe 47 and the second reverse on the secondary side (tub side). A stop valve 37 is positioned below the vertical pipe 47.
For this reason, when the feed water pressure P1 decreases and the inside of the vertical pipe 47 becomes negative pressure or lower than the water pressure P2 on the secondary side, the return water of the bathtub 3 flows into the vertical pipe 47. Even if the first check valve 36 is pulled over the second check valve 37 located at the lower part, the first check valve 36 is located above the vertical pipe 47, and therefore, the backflow water that has entered the vertical pipe 47 is prevented. The possibility that the reverse flow to the water supply pipe 20 side proceeds beyond the first check valve 36 is reduced.

また、本実施形態の逆流防止装置３１によれば、逆流防止弁３８の開放口７５，７５が弁筒体６１に対して上下方向に離間して独立して形成されているので、給水圧Ｐ１が低下して縦向き管４７の内部が負圧になったり二次側の通水圧Ｐ２よりも低圧になったりした場合に、上方の開放口７５が主として大気開放機能を担い、下方の開放口７５主として逆流水排水機能を担うことになる。
従って、大気開放と逆流水排水とをそれぞれ上下の開放口７５，７５に役割分担させることができ、縦向き管４７に対する大気開放と逆流水排水がより確実に達成される。 Further, according to the backflow prevention device 31 of the present embodiment, the opening 75, 75 of the backflow prevention valve 38 is formed separately from the valve cylinder 61 in the vertical direction and is thus independently formed. When the internal pressure of the vertical pipe 47 becomes negative or lower than the water pressure P2 on the secondary side, the upper open port 75 mainly serves the air release function, and the lower open port 75 Mainly responsible for the backflow water drainage function.
Therefore, the air release and the backflow water drainage can be assigned to the upper and lower open ports 75 and 75, respectively, and the air release and the backflow water drainage with respect to the vertical pipe 47 can be more reliably achieved.

本発明は上記実施形態に限定されるものではない。
例えば、上記実施形態では、縦向き管４７に逆流防止弁３８を配置しているが、この逆流防止弁３８を水平管に接続することにしてもよい。また、その縦向き管４７は、必ずしも図示の鉛直方向でなくてもよく、所定角度で傾斜した管路で構成してもよい。
更に、上記実施形態では、逆止弁３６，３７と逆流防止弁３８を管路中に一体に組み込んだバルブユニットよりなる逆流防止装置３１を例示したが、この装置３１は、ユニット化されていない複数の管路と弁装置で分割構成することもできる。 The present invention is not limited to the above embodiment.
For example, in the above embodiment, the backflow prevention valve 38 is disposed in the vertical pipe 47, but the backflow prevention valve 38 may be connected to a horizontal pipe. Further, the vertical pipe 47 does not necessarily have to be in the illustrated vertical direction, and may be configured by a pipe line inclined at a predetermined angle.
Furthermore, in the above-described embodiment, the backflow prevention device 31 including the valve unit in which the check valves 36 and 37 and the backflow prevention valve 38 are integrated in the pipe is illustrated, but the device 31 is not unitized. A plurality of pipes and valve devices can be divided.

本発明の逆流防止装置の一例を示す斜視図である。It is a perspective view which shows an example of the backflow prevention apparatus of this invention. 同逆流防止装置の正面図である。It is a front view of the backflow prevention device. 同逆流防止装置の左側面図である。It is a left view of the backflow prevention device. 同逆流防止装置の右側面図である。It is a right view of the backflow prevention device. 図２のＡ−Ａ線断面図である。It is the sectional view on the AA line of FIG. 図３のＢ−Ｂ線断面図である。FIG. 4 is a sectional view taken along line BB in FIG. 3. 本発明の逆流防止装置を用いた給湯システムの配管構成図である。It is a piping lineblock diagram of the hot-water supply system using the backflow prevention device of the present invention.

符号の説明Explanation of symbols

１ 給湯システム
２ ガス給湯器（給湯装置）
３ 浴槽
１７ 給水管
２０ 給湯管
３０ 分岐管
３１ 逆流防止装置
３２ 注湯管
３４ 注湯水量センサ
３５ 注湯電磁弁
３６ 第一逆止弁
３７ 第二逆止弁
３８ 逆流防止弁
３９ 排出管
４１ 第一管路
４２ 第二管路
４３ 水平管
４４ 縦向き管
４６ 水平管
４７ 縦向き管（通水部分）
６１ 弁筒体
６２ 弁座
６３ 第一弁体
６４ メインダイヤフラム
６５ 第二弁体
６６ サブダイヤフラム
７２ 背圧室
７３ 導入口
７４ 開放通路
７５ 開放口
７７ 背面壁
７８ 貫通孔
７９ 荷重軽減手段
８０ 受圧板 1 Hot-water supply system 2 Gas water heater (hot-water supply device)
3 Bath 17 Water supply pipe 20 Hot water supply pipe 30 Branch pipe 31 Backflow prevention device 32 Pouring pipe 34 Hot water quantity sensor 35 Pouring solenoid valve 36 First check valve 37 Second check valve 38 Backflow prevention valve 39 Drain pipe 41 One pipe 42 Second pipe 43 Horizontal pipe 44 Vertical pipe 46 Horizontal pipe 47 Vertical pipe (water flow portion)
61 Valve body 62 Valve seat 63 First valve body 64 Main diaphragm 65 Second valve body 66 Sub diaphragm 72 Back pressure chamber 73 Inlet port 74 Opening passage 75 Opening port 77 Back wall 78 Through hole 79 Load reducing means 80 Pressure receiving plate

Claims (6)

内部に弁座を有する弁筒体と、前記弁座に接離自在に当接するように前記弁筒体内に収納された弁体と、この弁体を前記弁筒体の軸心方向に移動自在に支持するダイヤフラムとを備え、前記弁筒体の内部でかつ前記ダイヤフラムの背面側に形成された背圧室に給水圧が負荷される逆流防止弁において、
前記背圧室の給水圧によって発生する前記弁体に対する前記弁座への押し付け力を軽減する荷重軽減手段が設けられ、
前記荷重軽減手段は、前記弁体の背面側から突設された当該弁体よりも小径の第二の弁体と、この第二の弁体を前記弁筒体の軸心方向に移動自在に支持する第二のダイヤフラムと、この第二のダイヤフラムを前記第二の弁体に固定する受圧板とから構成され、
前記第二の弁体は前記背圧室の背面壁に形成された貫通孔を貫通しており、前記第二のダイヤフラムは前記貫通孔を密閉した状態で前記背圧室の背面壁に取り付けられていることを特徴とする逆流防止弁。 A valve body having a valve seat therein, a valve body housed in the valve body so as to come into contact with and away from the valve seat, and the valve body movable in the axial direction of the valve body A backflow prevention valve in which a feed water pressure is applied to a back pressure chamber formed inside the valve cylinder and on the back side of the diaphragm.
A load reducing means for reducing a pressing force to the valve seat against the valve body generated by a water supply pressure of the back pressure chamber is provided;
The load reducing means includes a second valve body having a smaller diameter than the valve body protruding from the back side of the valve body, and the second valve body is movable in the axial direction of the valve body. A second diaphragm to support, and a pressure receiving plate for fixing the second diaphragm to the second valve body;
The second valve body passes through a through hole formed in the back wall of the back pressure chamber, and the second diaphragm is attached to the back wall of the back pressure chamber with the through hole sealed. A backflow prevention valve characterized by 前記弁体の開時に前記ダイヤフラムの正面側の大気開放を行う複数の開放口が、前記弁筒体に対して上下方向に離間して独立して形成されている請求項１に記載の逆流防止弁。 A plurality of open ports for performing the air release on the front side of the diaphragm to open during the valve body, the backflow prevention according to claim 1, which is formed independently spaced in the vertical direction with respect to the valve cylindrical body valve. 給湯管の温水を浴槽に通水する管路と、前記浴槽への通水のみを許容するように前記管路に直列に設けられた一対の逆止弁と、前記管路における前記両逆止弁間の通水部分に設けられた請求項１又は２に記載の逆流防止弁とを備えた逆流防止装置であって、
前記逆流防止弁により前記給湯管への給水圧をパイロット圧として前記通水部分に対する大気開放と逆流水排水を行うことを特徴とする、請求項１又は２に記載の逆流防止弁を用いた逆流防止装置。 A pipe for passing hot water of the hot water supply pipe to the bathtub, a pair of check valves provided in series in the pipe so as to allow only water to the bathtub, and the both check in the pipe A backflow prevention device comprising the backflow prevention valve according to claim 1 or 2 provided in a water flow portion between the valves,
The backflow using the backflow prevention valve according to claim 1 or 2 , wherein the backflow prevention valve performs air release and backflow water drainage with respect to the water flow portion by using a feed water pressure to the hot water supply pipe as a pilot pressure. Prevention device. 前記通水部分は、その通水方向上流側が上方に位置する上下方向に長い縦向き管により構成されている請求項３に記載の逆流防止装置。 The backflow prevention device according to claim 3 , wherein the water flow portion is configured by a vertical pipe that is long in an up-down direction with an upstream side in a water flow direction positioned upward. 上水が給水される給水管と、
この給水管に給水された上水を加熱する熱交換器と、
この熱交換器で加熱された温水を外部に給湯する給湯管と、
この給湯管と浴槽との間に介装された請求項３又は４に記載の逆流防止装置とを備えていることを特徴とする給湯装置。 A water supply pipe to which clean water is supplied;
A heat exchanger that heats the clean water supplied to the water supply pipe;
A hot water supply pipe for supplying hot water heated by the heat exchanger to the outside,
A hot water supply apparatus comprising the backflow prevention device according to claim 3 or 4 interposed between the hot water supply pipe and a bathtub. 請求項５に記載の給湯装置と、
前記給湯管からの温水が前記逆流防止装置を介して給湯される前記浴槽とを備えていることを特徴とする給湯システム。 A hot water supply apparatus according to claim 5 ;
A hot water supply system, comprising: the hot water supplied from the hot water supply pipe through the backflow prevention device.
JP2007224764A 2007-08-30 2007-08-30 Backflow prevention valve, backflow prevention device having the same, hot water supply device and hot water supply system Expired - Fee Related JP5067080B2 (en)

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