JPH0756416B2 - Backflow prevention device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backflow prevention device provided between a clean water circuit and a miscellaneous water circuit to prevent backflow of miscellaneous water.

[0002]

2. Description of the Related Art FIG. 8 is a sectional view of a conventional backflow prevention device F. An air charge chamber 102 is formed in the center of the casing 101, and an overflow chamber 103 is provided below the air charge chamber 102. Between the air charge chamber 102 and the overflow chamber 103,
The remaining hot water in the air charge chamber 102 is overflow chamber 10
A drain hole 104 is formed for draining to the 3 side. In the air charge chamber 102, an integrated first check valve 1
05 and the air charge valve 106 are delivered, the first check valve 105 is elastically urged in the closing direction of the inlet 108 by the spring 107, and the air charge formed on the lower surface of the first check valve 105. The valve 106 faces the drain hole 104. An outlet pipe 110 is connected to an outlet 109 provided on the side wall of the air charge chamber 102, and the outlet pipe 110 is provided with a second check valve 111.

An atmosphere communication port 112 is opened at the center of the side surface of the overflow chamber 103.
The water drain hole 104 provided on the top surface of No. 3 is the atmosphere communication port 11
It is located above 2. Also, overflow chamber 1
The drain port 113 is opened on the bottom of 03, and the drain port 113
Is connected to the outflow pipe 110 by a branch pipe 114, and a drain opening / closing valve 115 is attached to the branch pipe 114.

However, when the drop-in on-off valve 116 provided on the inlet 108 side of the air charge chamber 102 is opened, the first check valve 105 causes the spring 10 to move by the water pressure.
It is pushed down against 7 and the entrance 108 of the air charge chamber 102 is opened. At the same time, the air charge valve 106 is also pushed down (the state at this time is changed to the first check valve 105 in FIG. 8).
And the right half of the air charge valve 106. ), The drain hole 104 is closed by the air charge valve 106. Therefore, the water flowing into the air charge chamber 102 fills the air charge chamber 102 and is further discharged from the outflow pipe 110.

On the contrary, when the drop opening / closing valve 116 is closed, no water pressure is applied to the first check valve 105, so that the first check valve 105 rises and the air charge chamber 1
02 Inlet 108 is closed and air charge valve 1
06 rises to open the water drain hole 104, and the inside of the air charge chamber 102 is immediately replaced with air (the state at this time is
The first check valve 105 and the air charge valve 106 are shown in the left half), and the air charge chamber 102 is trimmed on the inlet 108 side and the outlet 109 side. At the time of replacement with air, air is supplied to the air charge chamber 102 through the path of the atmosphere communication port 112 → overflow chamber 103 → drainage hole 104.

Further, the drainage on-off valve 115 is normally closed, and the water dropped from the air charge chamber 102 into the overflow chamber 103 is temporarily stored in the overflow chamber 103. The water in the overflow chamber is normally discharged from the branch pipe 114 to the outflow pipe 1 by opening the drainage on-off valve 115.
However, when the amount of water in the overflow chamber unexpectedly overflows due to a failure of the air charge valve 106 or the like, the air is discharged from the atmosphere communication port 112 to the outside.

[0007]

In the conventional backflow prevention device, since the water accumulated in the overflow chamber is discharged from the branch water passage to the outflow pipe, a branch pipe and a drainage on-off valve are required, and the backflow is prevented. The structure of the preventive device is complicated, and the cost of the backflow preventive device is high. Further, since a branch pipe and an on-off valve for drainage are required, there is a drawback that the backflow prevention device becomes large.

Further, since the first check valve and the air charge valve operate at the water pressure, the water pressure is low when the air charge valve is closed and water is being supplied to the air charge chamber.
If the backflow prevention device is installed above the bathtub of the water supply destination and there is a drop, the air charge chamber will not be sufficiently high and the air charge valve will not close properly, and water will leak from the drain hole to the overflow chamber. There has been a problem that the water accumulated in the overflow chamber overflows from the atmosphere communication port to the outside and wets the inside of the device incorporating the backflow prevention device.

The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and an object thereof is to simplify the structure to reduce the size and weight of the backflow prevention device and reduce the cost. Further, it is to prevent water from overflowing in the overflow chamber due to water leakage from the air charge valve.

[0010]

A backflow prevention device of the present invention is provided in an air charge chamber provided in a connection circuit between a clean water circuit and a miscellaneous water circuit, and in a clean water circuit side of the air charge chamber. A valve means for opening and closing the circuit and a water drain hole communicating with the air charge chamber are opened at the lower end, and the atmosphere communication port is arranged at a position higher than the opening position of the water drain hole to store water in the air charge chamber. An overflow chamber that can be opened to the atmosphere, an air charge valve that opens and closes a water drain hole between the overflow chamber and the air charge chamber, opening of the valve means and closing of the air charge valve, and closing of the valve means And a valve driver for interlocking the opening of the air charge valve.

[0011]

According to the present invention, since the water drain hole communicating with the air charge chamber is opened at the lower end of the overflow chamber and the atmosphere communication port is arranged at a position higher than the opening position of the water drain hole, The vent hole is sealed with water accumulated in the overflow chamber. Therefore, after the water flow is stopped, the water accumulated in the overflow chamber can be drained to the miscellaneous water circuit by sucking with the pump provided in the miscellaneous water circuit.

Therefore, unlike the conventional backflow prevention device, a branch pipe and a drainage on-off valve are not required, the structure of the backflow prevention device can be simplified, and the backflow prevention device can be made compact and low in cost.

Further, since the air charge valve is opened and closed by the valve driver, the air charge valve can be opened even when the water pressure is low or the backflow prevention device is installed above the water supply destination such as a bathtub or the like. It can be securely closed, and the improved sealing prevents water from leaking to the overflow chamber, preventing overflow of the overflow chamber and spilling of water from the atmosphere communication port to the outside. Therefore, the backflow prevention device is less likely to be restricted by the installation location.

[0014]

1 is a schematic view of a bathtub equipped with a backflow prevention device A according to an embodiment of the present invention. The bath adapter 2 of the bathtub 1 is connected to a circulation circuit 3 for reheating, and the circulation circuit 3 is provided with a bath heat exchanger 4, a three-way valve 5, and a circulation pump 6. The hot water supply circuit 8 connected to the hot water supply device 7 is directly connected to the three-way valve 5 of the circulation circuit 3. The hot water supply circuit 8 is provided with a water amount sensor 9, a drop opening / closing valve 10 and first and second check valves 11 and 12, and an air charge chamber 13 is formed between the check valves 11 and 12. There is. Both check valves 11 and 12 are arranged in a direction to prevent backflow from the circulation circuit 3 side to the water heater 7 side. The air charge chamber 13 has a structure capable of holding hot water or air therein, and the air charge chamber 13 communicates with an overflow chamber 15 through a water drain hole 14.
In the overflow chamber 15, the drain hole 14 opens at the lower end of the overflow chamber 15, and the atmosphere communication port 16 for opening the overflow chamber 15 to the atmosphere is located above the opening position of the drain hole 14. The volume of the space below the atmosphere communication port 16 of the overflow chamber 15 is larger than the volume of the air charge chamber 13.
An air charge valve 17 for opening and closing the water drain hole 14 is provided between the air charge chamber 13 and the overflow chamber 15. The second check valve 12 is pushed open by the water pressure, but the first check valve 11 and the air charge valve 17 are electrically opened / closed by the solenoid 18. That is, the air charge valve 17 is closed at the same time when the first check valve 11 is opened, and conversely, the air charge valve 17 is opened at the same time when the first check valve 11 is closed.

FIG. 2 is a plan view of a backflow preventive device A in which the portion surrounded by the one-dot chain line in FIG. 1 is integrally formed, and FIG.
4 and FIG. 4 are cross-sectional views at the XX position and the YY position. As shown in FIG. 4, an inlet pipe connection port 20 is opened in the upper side surface of the casing 19, and a hot water supply inlet pipe 22 that constitutes a hot water supply circuit 8 is connected to the inlet pipe connection port 20 for housing a filter 21. The hot water supply inlet pipe 22 is provided with a water amount sensor 9 so that the hot water heated by the water heater 7 is fed into the casing 19 through the inlet pipe connection port 20. An air charge chamber 13 is formed in the center of the casing 19, and the air charge chamber 13 is formed.
An overflow chamber 15 is provided on the side of the, as shown in FIG. Air charge chamber 13 and overflow chamber 1
5 is communicated with the remaining hot water in the air charge chamber 13 through a drain hole 14 for draining the remaining hot water into the overflow chamber 15 and sending replacement air from the overflow chamber 15 to the air charge chamber 13. As shown in FIG. 3, the overflow chamber 1
In FIG. 5, a water drain hole 14 is opened on the side surface of the lower end portion, and an atmosphere communication port 1 communicating with the atmosphere is formed on the side surface of the upper end portion.
6 is opened, and the volume of the overflow chamber 15 below the atmosphere communication port 16 is slightly larger than the volume of the air charge chamber 13. A second check valve 12 is provided at the outlet of the air charge chamber 13, and below the second check valve 12, there is a hot water supply pipe 23 that constitutes a hot water supply circuit 8 and is connected to the three-way valve 5. It is press-fitted. Then, in the casing 19 of the backflow prevention device A, the inlet connection port 20 →
The hot water supply circuit 8 is configured by a route of the air charge chamber 13 → the second check valve 12 → the hot water supply outlet pipe 23.

Further, the inlet pipe connection port 20 communicates with an inlet 24 of the air charge chamber 13, and a drop opening / closing valve 10 is provided in a water passage connecting the inlet pipe connection port 20 and the inlet 23 of the air charge chamber 13. . Drop open / close valve 1
Reference numeral 0 denotes a solenoid type solenoid valve, in which a diaphragm valve 26 is arranged so as to face a valve seat 25 formed in the casing 19, the outer peripheral portion of the diaphragm valve 26 is fixed to the casing 19, and a plunger of the solenoid 27 is provided. The tip of 28 is connected to the center of the diaphragm valve 26. Therefore, when the plunger 28 is projected, the diaphragm valve 26 is brought into pressure contact with the valve seat 25, and the hot water supply circuit 8 is closed on the inlet 24 side of the air charge chamber 13.

The first check valve 11 is arranged in the air charge chamber 13 so as to face the inlet 24, and the inlet 24
A rubber packing 29 is provided so as to surround the.
The air charge valve 17 is arranged in the air charge chamber 13 so as to face the outlet 30 to the water drain hole 14, and a rubber packing 31 is provided so as to surround the outlet 30. The outer diameter of the first check valve 11 is larger than the outer diameter of the air charge valve 17, and the first check valve 11 and the air charge valve 17 are integrally attached to the plunger 32 of the solenoid 18. , Solenoid 18 is interlocked. That is, the plunger 32 of the solenoid 18
When the valve is projected, the first check valve 11 is closed and at the same time, the air charge 17 valve is opened, and the plunger 32 of the solenoid 18 is opened.
When is retracted, the first check valve 11 is opened and at the same time the air charge valve 17 is closed.

When the hot water is not supplied, the diaphragm valve 26 is closed, the first check valve 11 is closed, and the air charge valve 17 is opened. The overflow chamber 15 is filled with air.

On the other hand, when hot water supply is started, the solenoid 18 is driven to open the first check valve 11 and the air charge valve 17 is closed (the state at this time is changed to the first check valve 11 in FIG. 4).
And the upper half of the air charge valve 17) and then the diaphragm valve 26. In this case, the drain hole 14 communicating with the overflow chamber 15 is closed by the air charge valve 17. Therefore, the hot water flowing into the air charge chamber 13 fills the air charge chamber 13 without leaking from the water drain hole 14 to the overflow chamber 15 side, and further pushes the second check valve 12 open by water pressure, and the circulation circuit 3 Hot water is supplied to the side. At this time, the air charge valve 17 has the solenoid 18
Since it is forcibly closed by, the hot water does not leak into the overflow chamber 15, and there is no fear that a large amount of hot water will be accumulated in the overflow chamber 15.

On the contrary, when the hot water supply is finished, if the diaphragm valve 26 is closed, the water pressure is not applied to the second check valve 12, so the second check valve 12 is closed and the reverse flow of miscellaneous water is caused. Is prevented. Then, the solenoid 18 closes the first check valve 11 and opens the air charge valve 17 (the state at this time is shown by the lower half of the first check valve 11 and the air charge valve 17 in FIG. 4). Hot water in the air charge chamber 13 flows into the overflow chamber 15, and the air charge chamber 13 is replaced with air. Therefore, the first check valve 11 is closed to prevent backflow of miscellaneous water, and the inside of the air charge chamber 13 is replaced with air, so that the water heater 7 side and the circulation circuit 3 side are cut off. After that, the circulation pump 6 is operated,
When the inside of the air charge chamber 13 is set to a negative pressure, the drain hole 14 is water-sealed in the overflow chamber 15, so that the hot water in the overflow chamber 15 is drawn to the air charge chamber 13 and the second check valve 12 is opened. After passing through, it is drained to the circulation circuit 3, and the inside of the overflow chamber 15 becomes empty again.

Even if miscellaneous water flows backward and passes through the second check valve 12, the diameter of the first check valve 11 is larger than the diameter of the air charge valve 17, so the first check valve 11 Has a large back pressure,
The first check valve 11 is closed by water pressure and the air charge valve 17
The reverse flow water overflows in the overflow chamber 15 and does not flow back to the diaphragm valve 26 side. Moreover, since the upper end of the valve seat 25 with which the diaphragm valve 26 contacts is located higher than the height of the atmosphere communication port 16 of the overflow chamber 15, even if the overflow chamber 15 overflows due to a large amount of backflow water,
The miscellaneous water does not flow back over the diaphragm valve 26 and is discharged to the outside from the atmosphere communication port 16 of the overflow chamber 15.

FIG. 5 is a schematic view of a bathtub equipped with a backflow prevention device B according to another embodiment of the present invention. The hot water supply circuit 8 is provided with a water amount sensor 9, a drop opening / closing valve 10 and a second check valve 12, and an air charge chamber 13 is formed between the drop opening / closing valve 10 and the second check valve 12. There is. The air charge chamber 13 communicates with the overflow chamber 15 through the water drain hole 14. In the overflow chamber 15, the water drain hole 14 is opened at the lower end of the overflow chamber 15, and the atmosphere communication port 16 is opened above the opening position of the water drain hole 14. Air charge room 1
An air charge valve 17 for opening and closing the water drain hole 14 is provided between the valve 3 and the overflow chamber 15. The diaphragm valve 26 and the air charge valve 17 of the drop opening / closing valve 10 are electrically opened / closed by a solenoid 27 of the drop opening / closing valve 10. That is, the air charge valve 17 is closed at the same time as the diaphragm valve 26 is opened, and conversely, the air charge valve 17 is opened at the same time as the diaphragm valve 26 is closed.

FIG. 6 is a sectional view of a backflow preventive device B in which the portion surrounded by the one-dot chain line in FIG. 5 is integrally constructed. In this embodiment, the air charge chamber 13 is formed between the diaphragm valve 26 of the drop solenoid valve 10 and the second check valve 12, and the overflow chamber is formed adjacent to the air charge chamber 13. 15 and air charge room 1
3 and 3 are communicated with each other by a drain hole 14. The opening of the water drain hole 14 is located at the lower end of the overflow chamber 15, and the atmosphere communication port 16 is located at the upper end of the overflow chamber 15. The inlet side of the air charge chamber 13 is opened and closed by a diaphragm valve 26, and a leak hole 41 is provided at the edge of the diaphragm valve 26. Further, the plunger 28 of the drop-in solenoid valve 10 penetrates the outlet 30 to the water drain hole 14 and extends long, and the air charge valve 17 is slidably mounted in the water drain hole 14, A spring 43 is inserted between the flange 17 and a flange 42 fixed to the plunger 28. Then, the solenoid 27 causes the plunger 28 to
Is made to project, the inlet of the air charge chamber 13 is closed by the diaphragm valve 26 and the air charge valve 17 is opened, and conversely, the plunger 27 is opened by the solenoid 27.
When 8 is retracted, the diaphragm valve 26 is opened and the air charge valve 17 is closed.

When the hot water is not supplied, the diaphragm valve 26 is closed and the air charge valve 17 is opened. The overflow chamber 15 is filled with air.

On the other hand, when hot water supply is started, the solenoid 27 is driven to open the diaphragm valve 26 and close the air charge valve 17. In this case, since the water drain hole 14 communicating with the overflow chamber 15 is blocked by the air charge valve 17, the hot water flowing into the air charge chamber 13 does not leak from the water drain hole 14 and does not leak. Then, the second check valve 12 is pushed open by water pressure, and hot water is supplied to the circulation circuit 3 side.

On the contrary, when the hot water supply is finished, the diaphragm valve 26 is closed and the air charge valve 17 is opened. At this time, since the hot water enters the upper surface of the diaphragm valve 26 through the leak hole 41, water pressure is applied to the upper surface side of the diaphragm valve 26, and the diaphragm valve 26 is pressed against the valve seat 25 by the water pressure. Further, since the water pressure is not applied to the second check valve 12, the second check valve 12 is closed, and the backflow of miscellaneous water is prevented. Further, when the air charge valve 17 opens, the hot water in the air charge chamber 13 overflows into the overflow chamber 15.
The air charge chamber 13 is replaced with air by flowing into the air charge chamber 13 and the inside of the air charge chamber 13 is replaced with air, so that the water heater 7 side and the circulation circuit 3 side are cut off. After that, when the circulation pump 6 is operated and the inside of the air charge chamber 13 is made to have a negative pressure, the hot water in the overflow chamber 15 is removed.
Is discharged to the circulation circuit 3 through the second check valve 12, and the inside of the overflow chamber 15 is emptied again.

Moreover, in this embodiment, since only one solenoid 27 is used, the backflow prevention device can be made smaller and lighter and cheaper.

FIG. 7 shows still another embodiment of the present invention.
This is a modification of the structure of the embodiment of FIG. 6 so that the drop solenoid valve can be opened and closed smoothly. Therefore, it has the same structure as that of FIG. 6 except the part shown in FIG. In this embodiment, the upper end of the valve shaft 52 is slidably held in the recess 51 provided in the lower end surface of the plunger 28. The valve shaft 52 is a hollow body, and the upper end opening 5 of the vent hole 53 formed inside is formed.
4 is opened in the recess 51, and the lower end opening 55 is opened in the air charge chamber 13. Also, the valve shaft 52
The diaphragm valve 26 fixedly provided with a leak valve 56 is vertically penetrated. Further, another valve shaft 57 equipped with the air charge valve 17 is screwed onto the lower end of the valve shaft 52, and the lower end of the valve shaft 57 is slidably held by a holder 58 and is connected to the casing 19. It is urged upward by a spring 59 which is interposed therebetween.

When the plunger 28 is lowered by the solenoid 27, the upper end opening 54 of the vent hole 53 in the valve shaft 52 is closed, and the space 60 from the leak hole 56 of the diaphragm valve 26 to the upper surface side of the diaphragm valve 26. The hot water flows in, and the diaphragm valve 26 is moved to the valve seat 25 by the water pressure.
Is pressed against. On the other hand, when the plunger 28 rises, the air charge valve 17 is closed, a gap is created between the plunger 28 and the upper end of the valve shaft 52, the upper end opening 54 of the vent hole 53 is opened, and the air charge is passed through the vent hole 53. Room 1
Air enters the space 60 on the upper surface side of the diaphragm valve 26 from 3, the water pressure applied to the lower surface of the peripheral portion of the diaphragm valve 26 becomes larger than the air pressure applied to the upper surface, and the diaphragm valve 26 is quickly opened.

[0030]

According to the present invention, since the water drain hole communicating with the air charge chamber is opened at the lower end of the overflow chamber, and the atmosphere communication port is arranged at a position higher than the opening position of the water drain hole. After the water flow is stopped, the water accumulated in the overflow chamber can be drained to the miscellaneous water circuit by sucking with a pump provided in the miscellaneous water circuit.

Therefore, unlike the conventional backflow prevention device, the branch pipe and the drainage on-off valve are not required, the structure of the backflow prevention device can be simplified, and the backflow prevention device can be made compact and low in cost.

Since the air charge valve is opened and closed by the valve driver, the air charge valve can be opened even if the water pressure is low or the backflow preventive device is installed above the water supply destination such as a bathtub or the like. It can be securely closed, and the improved sealing prevents water from leaking to the overflow chamber, preventing overflow of the overflow chamber and spilling of water from the atmosphere communication port to the outside. Therefore, there is no restriction on the installation location of the backflow prevention device.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a bathtub with a water heater using a backflow prevention device according to an embodiment of the present invention.

FIG. 2 is a partially cutaway plan view showing the above-described backflow prevention device.

3 is a cross-sectional view taken along line XX of FIG.

FIG. 4 is an enlarged cross-sectional view taken along line YY of FIG.

FIG. 5 is a schematic configuration diagram showing a bathtub with a water heater using a backflow prevention device according to another embodiment of the present invention.

FIG. 6 is a sectional view showing the above-mentioned backflow prevention device.

FIG. 7 is a sectional view showing a part of still another embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a conventional backflow prevention device.

[Explanation of symbols]

 11 First Check Valve 13 Air Charge Chamber 14 Drain Hole 15 Overflow Chamber 16 Atmosphere Communication Port 17 Air Charge Valve 18 Solenoid 26 Diaphragm Valve 27 Solenoid

Claims (1)

[Claims] 1. An air charge chamber provided in a connection circuit between a tap water circuit and a miscellaneous water circuit, a valve means for opening and closing a circuit provided on the tap water circuit side of the air charge chamber, and an air charge chamber. An overflow chamber that is open to the atmosphere and that can hold water in the air charge chamber that has a drain hole that opens at the lower end and that has an atmosphere communication port that is higher than the opening position of the drain hole. And an air charge valve for opening and closing a water draining hole between the air charge chamber and the air charge chamber, the opening of the valve means and the closing of the air charge valve, and the closing of the valve means and the opening of the air charge valve, respectively. A backflow prevention device consisting of a valve driver that performs.