JP2689848B2 - Backflow prevention device for water heaters, etc. - 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 preventive device for preventing backflow of miscellaneous water or the like from a downstream side in a water heater or the like.

[0002]

2. Description of the Related Art As a backflow prevention device of this type, for example, a device disclosed in Japanese Utility Model Laid-Open No. 4-74212 is provided. As shown in FIG. 3, this device is configured to inject water from the hot water supply passage 1 into the bathtub B via the hopper 2, and to allow the overflow chamber 3 adjacent to and communicating with the hopper 2 to flow.
When water is injected, the valve 5 is pushed by the water flowing from the pipe 4 branched from the hot water supply passage 1 to close the drain port 6.

[0003]

However, in the above-mentioned conventional backflow prevention device, only a part of the water flowing through the hot water supply passage 1 is pipe 4.
To flow into the overflow chamber 3 and press the valve 5
Therefore, the water pressure to be pressed tends to be weak, and therefore the valve 5 cannot reliably close the drain port 6 even during water injection, and there is a problem that water easily leaks from the overflow chamber 3 during water injection. Further described in Japanese Utility Model Laid-Open No. 4-74212.
In the conventional backflow prevention device described above, the valve 5 in the overflow chamber 3 is
In order to apply pressure to the hot water supply channel 1
There was also the problem of having to branch off from it and install it.

Therefore, according to the present invention, it is possible to solve the above-mentioned drawbacks of the conventional device and prevent the reverse amount of sewage water from the downstream water supply channel. Also in the above, it is an object of the present invention to provide a backflow prevention device in a water heater or the like, which can surely close the overflow port, and thus can reliably prevent leakage of injected water and mixing of air. In addition, the whole device is one
As a unit that is easy to install, special piping, etc.
Backflow prevention device for water heaters that does not require separate equipment
The purpose is to provide the device.

[0005]

In order to achieve the above object, a backflow prevention device in a water heater or the like according to the present invention temporarily supplies hot water or water from upstream water supply passages U1 and U2 through on-off valves V1 and V2. a receiving vessel 10 for receiving, a hopper-shaped darken outer cylindrical body 20 which is coupled in communication with the bottom center of darken opening 11 of the receiving purse vessel 10, and the outer cylinder 20 in the darken outer cylindrical body 20 The receiving container portion 10 is arranged in a double tubular shape with an appropriate gap S formed.
Inner cylinder 30 that allows most of the water from the drop-in port 11 to flow in and flow out of the device from the lower end opening, and an overflow port that is opened in the side wall of the drop-out outer cylinder 20.
21 , a normally-open spring-biased diaphragm valve 50 for opening and closing the overflow port 21 , and a normally-open spring-biased diaphragm valve 50 against the spring 51 to prevent the overflow port 21.
And a pressure chamber 60 for pressing to the side
A pressure introduction passage 61 to the receiving container portion 10 is provided.
By extending and providing the pressure introducing passage 61,
Container part 10, outer cylinder 20, inner cylinder 30, and normally open spring biasing device
One whole device consisting of earflame valve 50 and pressurizing chamber 60
It is characterized by being configured as a unit of .

[0006]

According to the above feature of the present invention, at the time of water injection, the water injection from the upstream water supply passages U1 and U2 is performed by opening and closing the open / close valves V1 and V2.
2 once enters the receiving container portion 10 and then passes through the drop opening 11 at the center of the bottom portion to the inner cylindrical body 30 inside the outer cylindrical body 20 .
Most of the water flows into the device and flows out of the device through the lower end opening. A part of the water injected into the receiving container 10 is a pressure introducing passage.
It enters into the pressurization chamber 60 through 61 , presses the normally open spring energizing diaphragm valve 50, and presses the normally open spring energizing diaphragm valve 50 to the overflow port 21 against the energizing spring 51 . On the other hand, since most of the water injection passes through the inside of the inner cylinder 30 inside the apparatus as a main passage, the gap S between the inner cylinder 30 and the outer cylinder 20 serves as a sub passage for water injection, and during water injection, Due to the ejector effect due to the outflow from the main passage, the inside of the sub passage is in a negative pressure state. As a result, the overflow port 21
Normally open spring-biased diaphragm valve that is pressed from outside
50 is also sucked from the inside by negative pressure, and as a result,
It tightly adheres to the overflow port 21 and seals. As described above, in the device of the present invention, the normally open spring-biased diaphragm valve 50 acts so as to be in close contact with the overflow port 21 not only by the pressing force using a part of the water injection but also by the negative pressure suction force during the water injection. As a result, the adhesion is strengthened, and the overflow port 21 is reliably closed. Therefore, the overflow port 21 can be reliably sealed even when the water injection flow rate decreases. Especially in the present invention, all water injection,
The receiving container part 10 for once receiving the pouring water is provided to
The pressure introducing passage 61 is connected to the pressurizing chamber 60 from the container case 10.
First, since it is configured to extend to the
Sufficient water pressure due to the total amount of water and hot water received in 10
Is added to the diaphragm valve 50 via the pressure introducing passage 61.
It is possible that. Second, of water and hot water coming from different pipes
Even if only one of them is selected and poured,
The pressure introducing passage 61 extends from the receiving container portion 10.
Therefore, even if you pour only one of water or hot water,
This surely pushes the diaphragm valve 50 to turn it on.
The overflow port 21 can be closed. Third, da
The pressure that provides the water pressure to push the earflam valve 50.
The introduction passage 61 extends from the receiving container portion 10
Since it is configured, the entire structure including the pressure introducing passage 61 is
Can be configured into one unit, mounting the device
There is no need to install a dedicated pipe separately
Can be

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a vertical cross-sectional view of a device for carrying out the present invention, showing a case where water is not poured. FIG. 2 is also a vertical cross-sectional view of the apparatus of the present invention, showing the time when hot water is being supplied as water.

Receiving container portion 10 provided at the top of the apparatus
Receives water and hot water from the upstream water supply passages U1 and U2 via electromagnetic on-off valves V1 and V2, respectively. An opening 11 is opened at the center of the bottom of the receiving container portion 10,
The drop-in outer cylinder body 20 is connected to the drop-in port 11 so as to communicate therewith. The drop-out outer cylinder body 20 has a hopper shape in which the lower portion is thin. Inside the drop-in outer cylinder body 20, an appropriate gap S is formed with the outer cylinder body 20, and the inner cylinder body 30 is arranged in a double-tube shape. This inner cylinder 30
The upper opening 31 is located directly below the drop port 11, and most of the water injected from the drop port 11 is in the inner cylindrical body 30.
Let it flow inside. That is, the inside of the inner cylinder 30 serves as a main passage for water injection. The inner cylindrical body 30 has a lower portion that is narrowed to form a double cylindrical tube concentric with the outer cylindrical body. A downstream side water supply passage L such as a hose 7 is connected to the double cylindrical pipe. The water that has flowed out of the device from the lower end opening of the inner cylindrical body 30 flows into the lower water supply passage L.

An overflow port 21 is provided on the side wall of the outer cylindrical body 20. An air charge chamber 40 is provided outside the overflow port 21, and a normally open spring-biased diaphragm valve 50 is arranged in the air charge chamber 40. The normally open spring-biased diaphragm valve 50 normally opens the overflow port 21 by a biasing spring 51. A pressure chamber 60 is provided behind the normally open spring-biased diaphragm valve 50, and the pressure chamber 60 is connected to a side portion of the receiving container 10 by a pressure introduction passage 61.

In the above structure, the backflow prevention device is
The whole is a single unit, and the acceptance capacity is
Connect the equipment part 10 to the upstream water supply passages U1 and U2, and connect the other
It is necessary to install other pipes etc. by connecting to the base 7.
Installation is complete. Since the on-off valves V1 and V2 are closed as shown in FIG. 1 when water is not injected,
Since water is not injected into the receiving container portion 10, therefore, a part of the water is not drawn into the pressurizing chamber 60 through the pressure introducing passage 61, and the pressurizing chamber 60 is not pressurized. The urging spring 51 keeps the overflow port 21 open. Therefore, in this state, when there is a backflow from the downstream side water supply passage L, the backwashed miscellaneous water is surely discharged from the overflow port 21, and the backflow to the upstream side water supply passages U1 and U2 above it. Do not reach

On the other hand, one of the on-off valves V1 and V2,
Alternatively, when both are opened (V2 on the hot water supply side is opened in FIG. 2) and water is injected, the water is poured into the receiving container part 10, and most of the water is dropped from the drop port 11 inside the outer cylinder 20. Then, most of it flows into the inner cylindrical body 30 which is the main passage, and flows out downward.
At this time, due to the momentum of the flow rate flowing out from the inner cylindrical body 30,
The gap S between the inner tubular body 30 and the outer tubular body 20 , which is the sub passage, is in a negative pressure state. Part of the water injection from the receiving vessel 10 is drawn into the pressure chamber 60 via the pressure introduction path 61, receiving
The water pressure in the container case 10 is also applied to the pressurizing chamber 60 and the die
Press the diaphragm valve 50 and set the diaphragm valve 50 to the spring 5.
Pushes in the direction of the overflow port 21 against 1 . The pressing force and the suction force due to the negative pressure state of the gap S act on the diaphragm valve 50, so that the diaphragm valve 50 surely closes the overflow port 21 and the overflow during water injection is reliably prevented. Further, the overflow port 21 can be reliably closed even when the amount of injected water is small. Therefore, leakage of water can be prevented and air can be mixed reliably from a large flow rate to a small flow rate.

[0012]

The present invention has the above-described structure and operation. According to the backflow prevention device for a water heater or the like according to claim 1, at the time of water injection, not only the pressing force using a part of the water injection but also the water injection Since the normally open spring-biased diaphragm valve 50 closes the overflow port 21 in combination with the suction force generated by the negative pressure generating action, the closing of the overflow port 21 is changed from a large flow rate injection to a small flow rate injection. It can be done reliably. It is possible to reliably prevent leakage and air inclusion during water injection. Of course, when water is not injected, the normally open spring-biased diaphragm valve 50 is reliably connected to the overflow port 2
Since 1 is opened, backflow to the upstream water supply passages U1 and U2 can be prevented. Especially in the present invention, all
Providing a receiving container part 10 that receives pouring water and pouring water
The pressure introducing passage 61 from the receiving container portion 10.
First, since it is configured to extend to the pressure chamber 60,
Depending on the total amount of water or hot water received in the container section 10,
A sufficient amount of water pressure is supplied to the diaphragm valve 5 via the pressure introducing passage 61.
Can be added to zero. Second, come from different pipes
A place where only one of water and hot water is selected and poured
Even if the pressure is increased, the pressure introducing passage 61 extends from the receiving container portion 10.
Since it has been prepared, you can pour only one of water or hot water.
Even if there is, it surely pushes the diaphragm valve 50.
Thus, the overflow port 21 can be closed. No.
3 provides water pressure to push the diaphragm valve 50
The pressure introducing passage 61 for receiving the
Since the structure is extended, the pressure introducing passage 61 is also included.
Can be configured as a single unit,
For installation, special piping must be installed separately.
And can be eliminated.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a device for carrying out the present invention, showing a state when water is not injected.

FIG. 2 is also a vertical cross-sectional view of the device of the present invention, showing the time when hot water is being supplied as water.

FIG. 3 is a cross-sectional configuration diagram of a conventional device.

[Explanation of symbols]

 10 receiving container part 11 drop port 20 drop outer cylinder 21 overflow port 30 inner cylinder 50 normally open spring energizing diaphragm valve 51 energizing spring 60 pressurizing chamber 61 pressure introducing passage S gap U1, U2 upstream water supply channel L downstream Side waterway

Claims (1)

(57) [Claims] And 1. A upstream side water supply path U1, receiving vessel 10 for receiving temporarily the hot water and water through the opening and closing valve V1, V2 from U2, communicates with the bottom center of darken opening 11 of the receiving purse vessel 10 A hopper-shaped drop-out outer cylinder body 20 to be joined, and the outer cylinder body 20 inside the drop-out outer cylinder body 20.
And an inner cylindrical body 30 that is arranged in a double-tube shape with an appropriate gap S formed therein and that allows most of the water from the drop-in port 11 of the receiving container section 10 to flow in and flow out of the apparatus from the lower end opening, An overflow port 21 opened in the side wall of the drop-out outer cylinder body 20 , a normally-open spring-biased diaphragm valve 50 for opening and closing the overflow port 21 , and a normally-open spring-biased diaphragm valve 50 provided with the spring 51. Pressure chamber 60 for pressing against overflow port 21 against
And has a pressure introducing passage 61 to the pressurizing chamber 60.
The pressure guide is provided by extending from the receiving container section 10.
The container portion 10 including the inlet passage 61, the outer cylindrical body 20, and the inner cylindrical body
30, normally open spring-biased diaphragm valve 50 and pressurizing chamber 60
A backflow prevention device for a water heater or the like, characterized in that the entire device is configured as a single unit .