JPH0794924B2 - 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 water pressure is lost, the water channel is opened to the atmosphere. The atmosphere opening valve is provided, and the air port of the atmosphere opening 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, since the number of valves is large and it is necessary to provide a check valve in opposition to the float valve in order to deal with the bathtub on the second floor, 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 and a solenoid valve that closes when there is no water flow are provided in the water passage from the water heater to the bath circulation circuit, the water passage is branched from the water passage downstream of the solenoid valve and the water flow sensor, and an overflow port is provided in the water passage. At this point, a hopper connected to the atmosphere is connected, a drain passage connected to the hot water supply water passage is connected from the hopper, and a check valve is provided downstream from a connection point of the hot water supply water passage with the drain passage, The passage and the drain passage are each provided with an on-off valve that opens and closes opposite to the solenoid valve.

(Example) Hereinafter, description will be given based on an illustrated example of the present invention. 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 passage 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 passage
A hopper connected to 11, communicating with the atmosphere at an overflow port 14. A drainage first passage 15 is connected to the hot water supply passage 2 from the hopper 13, 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 has a valve body 91 that closes a valve port 92 from above. 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 for the air charge valve 12, and the air charge valve body 121 is closed from below against the spring 123. Below the first partition wall 22 is a second
A partition wall 23 is formed, and a space between both the partition walls is a hopper chamber 24 that forms the hopper 13. An overflow port 14 is opened on the side wall of the hopper chamber 24 to open to the atmosphere. A drain port 162 is opened in the second partition wall 23 so that the drain valve body 161 is closed from below against the spring 163. The valve body 91, the air charge valve body 121, and the drainage valve body 161 of the solenoid valve 9 are one valve shaft and are opened and closed by the solenoid of the solenoid valve 9. 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.
And a hot water supply channel room 26 formed at the side of the drainage room 25 and a communication port 27
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 air charge valve body 121 and the drainage valve body 161 open their valve openings against the springs (left half of the figure). Then, when the hot water is dropped into the bathtub 5, the solenoid valve 9 is opened. Then hot water supply channel 2
At the same time that a water flow occurs, the air charge valve body 121 and the drainage 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 are closed, and 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 passage 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 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 hot water in the air charge chamber 29 above the water reservoir passage 11 flows into the hopper chamber 24, and the air from the overflow port 14 is replaced by the air charge valve port 122 (here, the water reservoir passage 11).
The air charge chamber 29 is filled with the air. Therefore, the hot water supply channel 2 is in communication with the atmosphere via the air charge valve 12 and the hopper 13. If the hot water accumulated in the hopper 13 is operated during the reheating, the three-way valve 8 is allowed to communicate with the hot water supply channel 2 side and the pump 6 for a certain period of time.
It is sucked into the bath circulation circuit 4.

Next, a case will be described in which the hot water supply water passage 2 has a negative pressure due to some reason such as water interruption during dropping. When the hot water supply channel 2 has a negative pressure, the water flow stops, and the water flow sensor 10 detects this and closes the solenoid valve 9. At the same time, air charge valve 12 and 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, since the air charge valve and the drain valve that operate in the opposite direction to the electromagnetic valve are provided, the reverse flow of the water channel can be prevented and the operation is stable. Moreover, in addition to the solenoid valve, there are four 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 the bathtub on the second floor. Compared with this, the structure is simple and compact.

When the air charge valve and the drain valve of the solenoid valve are opened and closed by one axis as in the present embodiment, only one solenoid is required, and the size can be further reduced. Since water pressure is applied to the drain valve in the opposite direction, the driving force of the solenoid can be 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 heater 2 …… Hot water supply channel 4 …… Bath circulation circuit 9 …… Solenoid valve 10 …… Water flow sensor 11 …… Water reservoir 12 …… First opening / closing valve 13 …… Hopper 14 …… Overflow port 15… … Drainage passage 16 …… Second opening / closing valve 17 …… Check valve

Continuation of the front page (56) Reference JP-A-2-37226 (JP, A)

Claims (1)

[Claims] 1. A water flow sensor and a solenoid valve that closes when the water flow is stopped are 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 solenoid valve and the water flow sensor, a hopper connected to the atmosphere at an overflow port is connected to the water reservoir passage, and a drain passage connected to the hot water supply passage is connected from the hopper. However, a check valve is provided downstream of a connection point of the hot water supply passage with the drain passage, and an opening / closing valve for performing an opening / closing operation opposite to the solenoid valve is provided in each of the water reservoir passage and the drain passage. Backflow prevention device for bath kettle with water heater.