JPH06103121B2 - Backflow prevention device for bath kettle with water heater - Google Patents

Description

TECHNICAL FIELD The present invention relates to a backflow prevention device for a bathtub with a water heater.

(Prior Art) As a backflow prevention device of this type, the applicant previously described in Japanese Patent Application No.
No. 187200 (JP-A-2-37226) was proposed. This is because a plurality of check valves are arranged in series in a water channel for supplying hot water from a water heater to a bath circulation circuit. When water pressure is applied between the check valves, the valves are closed, and when the water pressure is lost, the water channel is opened to the atmosphere. The atmosphere release valve is provided, and the air port of the atmosphere release valve is connected to the suction side of the pump of the bath circulation circuit via the float valve.

(Problems to be Solved by the Invention) However, with this, the operation of the float valve was unstable. Moreover, since the float requires a large volume, the backflow prevention device becomes large.
In addition, the number of valves is large, and a check valve must be provided in opposition to the float valve that is intended to correspond to the bathtub on the second floor, and the structure is complicated.

(Means for Solving the Problems) In order to solve the above problems, the present invention is characterized by the following configurations. That is, a water flow sensor is provided in a water passage for supplying water from the water heater to the bath circulation circuit, a water reservoir passage is branched from a water passage downstream of the water flow sensor, and a hopper connected to the atmosphere at an overflow port is connected to the water reservoir passage. A drain passage connected to the hot water supply passage is connected from the hopper, and a check valve is provided downstream of a connection point between the hot water supply passage and the drain passage.
An opening / closing valve that is opened / closed by a signal from a water flow sensor is provided in each of the water reservoir passage and the drainage passage.

(Example) Hereinafter, the present invention will be described based on an illustrated example. Reference numeral 1 is a water heater, and 2 is a hot water supply channel. 5 is a bathtub which is a part of the miscellaneous water circuit, and 4 is a bath circulation circuit for circulating bath water. A pump 6 and a bath water heater 7 are interposed in the bath circulation circuit 4. The hot water supply channel 2 is directly connected to the suction side of the pump 6 of the bath circulation circuit 4 via a three-way valve 8. Reference numeral 9 is a solenoid valve provided in the hot water supply channel, and 10 is a water flow sensor. Reference numeral 11 is a water reservoir passage branched from the hot water supply passage 2 downstream of the electromagnetic valve 9 and the water flow sensor 10, and is provided with an air charge valve (first opening / closing valve) 12. 13 is a water reservoir passage 11
A hopper connected to the above, communicating with the atmosphere at the overflow port 14. A drainage passage 15 is connected from the hopper 13 to the hot water supply passage 2, and a drainage valve (second opening / closing valve) 16 is provided. These on-off valves 12 and 16 are connected to the water flow sensor 10
Is controlled so that it closes when it detects water flow and opens when no water flow. Further, 17 is a check valve provided downstream of the connection point of the hot water supply passage 2 with the drain passage 15.

FIG. 2 is a detailed sectional view of the backflow prevention device 20 in which the portion surrounded by the broken line in FIG. 1 is integrally configured.
A solenoid valve 9 is arranged in the upper part of the casing 21, and a hot water supply channel 2 is connected to the side of the electromagnetic valve 9. The solenoid valve 9 is a pilot type solenoid valve, and the valve body 91 closes the valve port 92 upward. Below the valve port 92, a first partition wall 22 is formed in which the water reservoir passage 11 is opened. The air charge chamber 29 is located above the first partition wall 22. The water reservoir passage 11 serves as a valve opening 122 of the air charge valve 12, and the air charge valve body 121
Is closed from above against the spring 123. A second partition wall 23 is formed below the first partition wall 22, and a hopper chamber 24 that forms the hopper 13 is formed between the two partition walls. An overflow port 14 is opened on the side wall of the hopper chamber 24 to open to the atmosphere. A drain valve port 162 is opened in the second partition wall 23, and the drain valve body 161 is closed from above against the spring 163. The air charge valve body 121 and the drainage valve body 161 are opened and closed by the solenoid 28 with one valve shaft. A drainage chamber 25 forming a drainage passage 15 is provided between the second partition wall 23 and the lower casing, and the hopper chamber 24 is provided.
Hot water supply channel room 26 and communication port 27 formed on the side of the drainage room 25
It communicates with. A check valve 17 is provided below the hot water supply channel chamber 26.

Next, the operation of the above configuration will be described. When there is no water flow in the hot water supply channel 2, that is, when the solenoid valve 9 is closed, the solenoid 28 is not excited, and the air charge valve body 121 and the drainage valve body 161 are pushed by springs to open the valve ports. (Left half of the figure). Then, when the hot water is dropped into the bathtub 5, the solenoid valve 9 is opened. Then, a water flow is generated in the hot water supply channel 2, the solenoid 28 detected by the water flow sensor 10 is excited, and the air charge valve body 121 and the drain valve body 161 close the respective valve openings (right half of the figure). That is, the air charge valve 12
And the drain valve 16 is closed, so that the hot water does not flow into the hopper 13. Therefore, the hot water supplied from the water heater 1 passes through the hot water supply channel 2 and is dropped into the bath 5 from the bath circulation circuit 4 via the three-way valve 8. When the bathtub 5 is filled with hot water, the solenoid valve 9 is closed to complete the dropping. When the electromagnetic valve 9 is closed, the water flow disappears, and when the water flow sensor 10 detects this, the energization of the solenoid 28 is cut off, and the air charge valve body 121 and the drainage valve body 161 open the respective valve openings. That is, the air charge valve 12 and the drain valve 16 are opened. Then, the water reservoir passage 11
The hot water in the upper air charge chamber 29 flows into the hopper chamber 24, and instead, the air from the overflow port 14 fills the air charge chamber 29 through the air charge valve port 122 (here, the water reservoir passage 11). Therefore, the hot water supply channel 2 is in communication with the atmosphere via the air charge valve 12 and the hopper 13. The hot water accumulated in the hopper 13 is pumped at the time of reheating.
If the three-way valve 8 is connected to the hot water supply channel 2 side and the pump 6 for a certain period of time when operating the bath, the bath circulation circuit 4
Is sucked into.

Next, a case will be described in which the hot water supply channel 2 has a negative pressure due to some reason such as water interruption during dropping. If the hot water supply channel 2 becomes a negative pressure, the water flow will stop, so the air charge valve 12 and the drain valve
16 open. If the check valve 17 operates normally, backflow of sewage is prevented here, but if it does not work for some reason, sewage passes through the air charge valve 12 and the drain valve 16, and the hopper It is discharged from the overflow port 14 of 13 to the outside of the device. Therefore, there is no backflow to the water heater 1.

(Effect of the Invention) As described above, according to the present invention, the air charge valve and the drain valve are opened and closed by the signal of the water flow sensor, so that the reverse flow of the water channel can be prevented and the operation is stable. Moreover, there are three valves, an air charge valve, a drain valve, and a check valve. The check valve is located downstream of both on-off valves and can be used for a bathtub on the second floor. It becomes.

Further, if the air charge valve and the drain valve are opened and closed by one axis as in the present embodiment, only one solenoid can be used and the size can be further reduced, and even in the case of the bathtub on the second floor, the air charge valve and the drain valve can be used. Since water pressure is applied in the opposite direction, the driving force of the solenoid is small.

[Brief description of drawings]

FIG. 1 is a schematic view of a bathtub with a water heater using the backflow prevention device of the present invention, and FIG. 2 is a detailed sectional view of the backflow prevention device. 1 …… hot water supply device 2 …… hot water supply channel 4 …… bath circulation circuit 10 …… water flow sensor 11 …… water reservoir passageway 12 …… first on-off valve 13 …… hopper 14 …… overflow port 15 …… drainage passageway 16… … Second opening / closing valve 17 …… Check valve

Claims (1)

[Claims] 1. A water flow sensor is provided in a water passage for supplying hot water from a water heater to a bath circulation circuit, and a water reservoir is branched from a water passage downstream of the water flow sensor, and a hopper communicating with the atmosphere at an overflow port is provided in the water reservoir passage. A drain passage connected to the hot water supply water passage is connected from the hopper, and a check valve is provided downstream of a connection point of the hot water supply water passage with the drain passage, and a water flow sensor is provided in the water reservoir passage and the drain passage. A backflow prevention device for a bathtub with a water heater, which is provided with an on-off valve which is opened and closed by a signal of the above.