JPH0674854B2 - Backflow prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to tap water such as a bath apparatus in which a hot water supply path and an additional heating path that are in communication with water supply without an air release tank are integrated. The present invention relates to a backflow prevention device for preventing water other than clean water from flowing back to the clean water route side in a device in which the route (1) and a route other than clean water are connected.

(Prior art) For example, as a backflow device for preventing hot water in a bathtub installed at a high place from flowing backward to a clean water side route in a bath device configured by integrating hot water supply and reheating route Are disclosed in JP-A No. 1-169009.

As shown in FIG. 3, this backflow device is provided with a water inlet b at one end of the valve chamber a, a drain port c at the other end, and a water outlet d on the lateral side, and pressure contact with the water inlet b and the water outlet d, respectively. The first and second valve elements e and f, which are configured to be movable as described above, are urged by springs g and h in the pressure contact direction thereof, and the first valve element e is connected to the drain port c. The third valve body i is movably supported so as to be in pressure contact, and is urged by a spring j in the pressure contact direction. In this device, when water pressure is applied to the water inlet b in the state shown in FIG. 3 (a), the first valve body e firstly resists the bias of the spring g and the third valve body i Along with this, the valve moves downward in the figure to open the valve, and when the first valve element e moves a predetermined distance, the third valve element i comes into pressure contact with the drain port c, and the valve is closed. As described above, the first valve body e is opened and water pressure is also applied to the second valve body f, so that the second valve body f is also opened.

Further, in the state of FIG. 3 (b), when the water pressure on the water inlet side decreases due to water cutoff or other reasons, the first valve body e is closed as shown in FIG. 3 (a). When the second valve disc f on the side of the water outlet d fails because the third valve disc i moves in conjunction with the first valve disc e and moves to the open state. Also, the backflow from the water outlet d side toward the water inlet b is prevented.

(Problems to be Solved by the Invention) As described above, in the above-described device, when water pressure is applied to the water inlet b, the first valve body e is first in the open state, and after moving for a predetermined distance. The third valve body i operates to be closed. Even in such an operation, when the water flow rate is large, there is a short time from the opening of the first valve body e to the closing of the third valve body i, which causes inconvenience. Absent. However, when the amount of water flow is small, the movement distance of the first valve body e may be small and the third valve body j may not be closed. In such a case, since the first and third valve bodies e, i are simultaneously opened, the water introduced from the water inlet b continues to be wastefully discharged from the drain port c. Occurs.

The present invention is intended to solve the above problems.

(Means for Solving the Problems) The means for solving the above problems will be described with reference to the drawings corresponding to the embodiments.
A first valve body having a water inlet 2 in the upper part of the valve chamber 1, a drain port 3 in the lower part, a water outlet 4 in the lateral side, and a communication port 5 in the center side in the valve chamber 1. 6 is movably supported corresponding to the water inlet 2, and is urged by a spring 8 in the direction of the water inlet 2 to seal the periphery of the communication port 5 on the upper side of the first valve body 6. In addition, a pressure plate 10 provided with a bellows 9 that operates as a spring is provided, and a second valve body 13 corresponding to the drain port 3 is attached to a support rod 11 projecting from the pressure plate 10 through the communication port 5. The spring constant of the spring 8 is set larger than that of the bellows 9, and the bellows 9 holds the second valve when the first valve body 6 is in pressure contact with the water inlet 2. The body 13 is supported at a position separated from the drain port 3.

In the above structure, the valve chamber 1 is provided with the drain chamber 14 communicating with the drain port 3, the atmosphere communicating port 15 is provided in the upper part of the drain chamber 14, and the drain discharge port 16 is provided in the lower part. be able to. Further, a third valve element 18 biased toward the water outlet 4 by a spring 17 can be provided outside the water outlet 4 of the valve chamber 1.

(Operation) In the above structure, when water pressure is applied to the water inlet 2 side, this pressure is applied to both the first valve body 6 and the pressure plate 10, but the first valve body 6 is supported. Since the spring constant of the spring 8 is larger than the spring constant of the bellows 9 supporting the pressure plate 10, first, as shown in FIG.
10, the second valve body 13 descends with it and comes into pressure contact with the drain port 3 to close the valve. Next, the first valve body 6 also descends due to the water pressure, separates from the water inlet 2 as shown in FIG. 1 (c), becomes the valve open state, and water flow starts.

As described above, at the time when the first valve body 6 is opened and water communication is started, the second valve body 13 is already closed, so that the water inlet 2 and the drain port 3 are in communication. Therefore, regardless of the amount, the water that has flowed in from the water inlet 2 does not flow out from the drain port 3 and can all flow out from the water outlet 4. The inconvenience of continuously discharging wastefully does not occur.

(Example) Next, the Example of this invention is described about a figure.

FIG. 1 is a vertical cross-sectional view showing an embodiment of a backflow prevention device of the present invention. Reference numeral 1 represents a valve chamber, in which the water inlet 2 is at one end and the drain is at the other end. The mouth 3 is provided and the water outlet 4 is provided on the lateral side.

In the valve chamber 1, a first valve body 6 having a communication port 5 on the center side is movably supported corresponding to the water inlet 2, and is biased by a spring 8 in the direction of the water inlet 2. . Reference numeral 7 is a valve seat portion of the water inlet 2. On the upper side of the first valve body 6, there is provided a pressure plate 10 which seals the periphery of the communication port 5 and is provided with a bellows 9 which operates as a spring. Support rod 11 protruding through 5
In addition, a second valve body 13 corresponding to the drain port 3 is supported. Reference numeral 12 is a valve seat portion of the drain port 3. In such a configuration, the spring constant of the spring 8 is the bellows 9
And the bellows 9 is larger than the spring constant of
Has a structure in which the second valve body 13 is supported at a position separated from the drain port 3 when the first valve body 6 is in pressure contact with the water inlet 2. In the embodiment, the moving range of the first valve body 6 is wider than the moving range of the second valve body 13.

A drain chamber 14 is provided adjacent to the valve chamber 1 and communicates with the drain port 3 through the drain port 3.
An atmosphere communication port 15 is provided in the upper part of the above, and a drain discharge port 16 is provided in the lower part. Further, outside the water outlet 4 of the valve chamber 1, there is provided a third valve body 18 which is biased by a spring 17 toward the water outlet 4.

Next, FIG. 2 shows an example of a usage state of the backflow prevention device of the present invention. This is to connect the backflow prevention device to the water supply without passing through an atmosphere release tank or the like to form a hot water supply route and an additional heating route. It shows an example of a state in which it is used in a bath apparatus configured by integrating the above.

In this figure, reference numeral 19 is a water heater connected to the water supply, and a water inlet 2 of a backflow prevention device 22 of the present invention is connected to a hot water supply passage 20 passing through the water heater 19 via a hot water supply solenoid valve 21. is doing. Further, the water outlet 4 is connected to a first port 24a of a three-way valve 23 for hot water supply and additional heating via a check valve, and a common port 24c of the three-way valve 23 is fed to a bath 25. It is connected to the hot water path 26. In this embodiment, the check valve is the third valve body 18 which is integrally formed with the valve chamber 1. And
The return hot water route 27 from the bath tub 25 is connected to the second port 24b of the three-way valve 23 via the circulation pump 28 to provide the hot water feeding route 2
Together with 6, it constitutes the burning route. In addition, the hot water supply route 2
6 is equipped with a heat exchanger 29 for additional heating. Further, the drain discharge port 16 of the backflow prevention device 22 has a discharge solenoid valve 30 and a check valve 31.
The circulation pump of the return hot water passage 27 through the discharge pipe 32 provided with
Connected to the upstream side of 28.

In the above configuration, the hot water supply solenoid valve 21 is closed, and when the water flow is stopped as shown in FIG.
Is pressed against the water inlet 2 by the biasing force of the spring 8 and is in a closed state, and the second valve body 13 is separated from the drain port 3 by the bellows 9 via the support rod 11. It is supported by and is open.

In this state, the common port 24c with the first port 24a
When the three-way valve 23 is operated so as to communicate with each other and the hot water supply solenoid valve 21 is opened, the water pressure of the water supply connected to the water heater 19 is applied to the water inlet 2 side of the backflow prevention device 22. When water pressure is applied to the water inlet 2 side in this way, this pressure is applied to both the first valve body 6 and the pressure plate 10. At this time, the spring constant of the spring 8 supporting the first valve body 6 is larger than the spring constant of the bellows 9 supporting the pressurizing plate 10, so that when the above-mentioned water pressure is applied, it is changed as shown in FIG. ), First, the pressure plate 10 descends, and along with this, the second valve body 13 descends and the drain port 3
It is pressed against the valve seat portion 12 and the valve is closed. Next, the first valve body 6 also descends due to the water pressure, separates from the valve seat portion 7 of the water inlet 2, enters the valve open state, and water flow starts. In the embodiment, since the moving range of the first valve body 6 is configured to be wider than the moving range of the second valve body 13, when the first valve body 6 descends as described above, The pressurizing plate 10 is urged downward via the bellows 9 to act to maintain the valve closed state.

Thus, as shown in FIG. 1 (c), the first valve body 6
Since the second valve body 13 is already closed when the valve is opened, the water inlet 2 and the drain port 3 do not become in communication with each other, and therefore the water flowing from the water inlet 2 Irrespective of the amount, the water can be completely discharged from the water outlet 4 without being wastefully discharged from the drain port 3. In this way, the water flowing from the water inlet 2 into the valve chamber 1 moves due to the water pressure of the third valve body 18 as a check valve against the bias of the spring 17 to open the valve. It flows out from the water outlet 4, flows through the hot water supply path 20, flows into the hot water supply path 26 via the three-way valve 23, and is supplied into the bath 25. At this time, the hot water in the water heater 19 can be heated by operating the additional heating heat exchanger 29 as necessary.

When the pressure on the water outlet 4 side becomes higher than the pressure on the water inlet 2 side due to water cutoff or other reasons in such a water-flowing state, first the first valve body 6 rises and the water inlet 2 The valve seat 7 is pressed into a closed state, and the bellows 9 urges the second valve body 13 through the pressure plate 10 and the support rod 11.
Rises and moves away from the valve seat portion 12 of the drain port 3 to open the valve. Therefore, even if the third valve body 13 or a check valve that is appropriately provided in the other case malfunctions and flows back into the valve chamber 1 from the water outlet 4 side, the backflowed water does not completely flow back to the water inlet 2 side. Instead, it can be discharged together with opening to the atmosphere through the drain port 3 in the open state. The above operation is the same when the water flow state is changed to the water flow stop state. After the water inlet 2 is closed, the drain port 3 is opened and the inside of the valve chamber 1 is closed. The remaining water is discharged into the drain chamber 14 through the drain port 3.

The residual water discharged into the drain chamber 14 in this way is
When the discharge solenoid valve 30 is opened in the additional heating operation in which the second port 24b of the three-way valve 23 and the common port 24c are in communication with each other, the drain discharge port 16 is generated by the suction force of the circulation pump 28.
Can be introduced into the return hot water route 27 through the discharge pipe 32, and it is not necessary to install the discharge pipe 32 to other drainage points. However, if a drainage point exists near the backflow prevention device 22 of the present invention, the discharge pipe 32 connected to the drain discharge port 16 may be brought to this drainage point and discharged.

(Effects of the Invention) As described above, the present invention provides a tap water path and tap water such as a bath device in which a hot water supply path communicating with the tap water and an additional heating path are integrated without passing through an atmosphere release tank or the like. It is possible to reliably prevent water other than tap water from flowing back to the tap water route side by using it in a device that is connected to a water route other than The inlet and the drain port do not become in communication with each other. Therefore, regardless of the amount of the water, the water flowing in from the water inlet does not wastefully flow out from the drain port, and all can flow out from the water outlet. There is an effect.

[Brief description of drawings]

1 (a), (b), and (c) are explanatory vertical cross-sectional views showing the configuration and operation of an embodiment of the present invention, and FIG. 2 is an example of the configuration of a bath device using the device of the present invention. 3A and 3B are explanatory vertical cross-sectional views showing the configuration and operation of an example of a conventional backflow prevention device. Reference numeral 1 ... valve chamber, 2 ... water inlet, 3 ... drain inlet, 4
... water outlet, 5 ... communication port, 6 ... first valve body, 7,12 ...
… Valve seat, 8,17 …… Spring, 9 …… Bellows, 10 …… Pressurizing plate, 11 …… Support rod, 13 …… Second valve body, 14 …… Drain chamber, 15 …… Atmosphere communication port , 16 …… Drain outlet, 18 ……
Third valve body, 19 ... Water heater, 20 ... Hot water supply path, 21 ... Hot water supply solenoid valve, 22 ... Backflow prevention device, 23 ... Three-way valve, 24a
...... First port, 24b ...... Second port, 24c ...... Common port, 25 ...... Bath, 26 ...... Hot water supply route, 27 ...... Return hot water route, 28 ...... Circulation pump, 29 ...... Heat exchanger for reheating, 30 ……
Discharge solenoid valve, 31 …… Check valve, 32 …… Discharge pipe.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F24D 17/00 F24H 1/00 302 Z 9251-3L

Claims (3)

[Claims] 1. A water inlet is provided at an upper portion of the valve chamber, a drain port is provided at a lower portion thereof, and a water outlet is provided at a lateral side of the valve chamber.
While supporting the first valve body provided with a communication port on the center side so as to be movable in correspondence with the water inlet, and biased by a spring in the direction of the water inlet, on the upper side of the first valve body, A pressure plate provided with a bellows that closes the periphery of the communication port and acts as a spring is provided, and a second valve body corresponding to the drain port is provided on a support rod projecting from the pressure plate through the communication port. The spring constant of the spring is configured to be larger than the spring constant of the bellows, and the bellows allows the second valve body to come out of the drain port while the first valve body is in pressure contact with the water inlet. Backflow prevention device characterized in that it is configured to be supported at a separated position 2. A drain chamber is provided adjacent to the valve chamber of claim 1 so as to communicate with each other via a drain port, an atmosphere communication port is provided at an upper portion of the drain chamber, and a drain discharge port is provided at a lower portion. Backflow prevention device characterized by 3. A backflow prevention device, characterized in that a third valve element is provided outside the water outlet of the valve chamber according to claim 1, and the third valve element is biased by a spring toward the water outlet.