JPH0526362A - Reverse flow prevention device for water channel - Google Patents

Abstract

PURPOSE:To make up a pressure receiving plate of a water flow sensor and an impeller out of resin inexpensive and light in weight as well as to make sure of the operations of them, and thereby surely prevent water flow in a water channel from being reversed. CONSTITUTION:A hopper 11 is interposed between the upstream water channel 1a and the downstream water channel 1b of a water channel. A drainage 9 is admitted out of the hopper 11 through a first closing valve 15. A second closing valve 16 is interposed between the hopper 11 and the upstream water channel 1a. A water flow sensor 17 for detecting reverse flow is interposed in a space between both the closing valves 15 and 16 in the inside of the hopper 11. The first closing valve 15 is opened while the second closing valve 16 is concurrently closed upon detecting the reverse flow of the water channels 1a and 1b by means of the water flow sensor 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing backflow of water from a bathtub or the like to a waterworks or the like in a water passage from the waterworks or the like to a bathtub or the like.

[0002]

2. Description of the Related Art Conventionally, for example, in an apparatus for supplying hot water to a bathtub, a heat exchanger is provided in the middle of a water passage from the water supply to the bathtub, and water introduced from the water supply to the water passage is passed through the heat exchanger. It heats up and supplies it to the bathtub.

In this case, for example, when the bathtub is installed at a high place, if the water supply is cut off during hot water supply, water may flow backward from the bathtub to the water supply through the water passage.
Therefore, in this type of water passage, a check valve is provided to prevent backflow.

However, such a check valve alone cannot prevent backflow into the water supply when the check valve is damaged or malfunctions due to some cause.

Therefore, in this type of water passage, as disclosed in, for example, Japanese Utility Model Publication No. 3-11495, in addition to the check valve, a backflow prevention device is provided in the middle of the water passage, and It is known that a backflow is prevented in a water passage by a prevention device.

In this backflow prevention device, the upstream side (water supply side) of the water passage is connected to the upper hole of the hopper through a backflow prevention solenoid valve, and the downstream side of the water passage (tub side) is connected to the lower hole of the hopper. Further, the drainage path is led out from the side hole of the hopper through the drainage solenoid valve, and a water flow sensor for detecting a backflow in the water passage is provided upstream of the backflow prevention solenoid valve. .. In this case, the water passage upstream of the hopper and the check valve is connected to the water supply through the water solenoid valve and the heat exchanger in that order, and the water passage downstream of the hopper is provided with a check valve It is connected to the bathtub via a valve. The backflow solenoid valve is normally closed, and the drainage solenoid valve is normally open.

And in such a backflow prevention device,
During normal hot water supply to the bathtub, after opening the water solenoid valve to connect the water passage on the upstream side of the hopper to the water supply through the heat exchanger, open the backflow prevention solenoid valve and open the drainage solenoid valve. At this time, the hot water heated by the heat exchanger in the water passage is supplied from the water passage to the bathtub through the hopper.

In this backflow prevention device, water supply is cut off during hot water supply, and the check valve is damaged or malfunctions. Water in the bathtub flows back through the water passage to the water supply side through the hopper. In such a case, the backflow is detected by the water flow sensor, and the backflow prevention solenoid valve is closed and the drainage solenoid valve is opened in response to the detection. As a result, the backflow preventing solenoid valve prevents water from flowing back from the bathtub to the water supply side, while the water is drained from the hopper through the drainage solenoid valve and the drainage channel.

However, such a backflow prevention device has the following disadvantages.

That is, although the above-mentioned water flow sensor is generally composed of a water flow switch having a swingable pressure receiving plate, a flow rate sensor having a rotary impeller, and the like, the water flow sensor is as described above. If it is on the upstream side (water supply side) of the backflow prevention solenoid valve, for example, when the water solenoid valve is opened to supply hot water to the bathtub, the high water pressure of the water supply is applied to the pressure receiving plate and the impeller of the water flow sensor. It will be. Therefore, the pressure receiving plate and the impeller of the water flow sensor are required to have a high degree of pressure resistance, and therefore, these pressure receiving plates and the impeller are made of metal, for example.

However, if the pressure receiving plate and the impeller of the water flow sensor are made of metal as described above, the inertial weight becomes large, the sensitivity of the water flow sensor is lowered, and rust occurs due to contact with water. There was fear. And if rust-proofing is applied to prevent rusting, it must be expensive,
It is a cost disadvantage.

[0012] Usually, in this type of water passage,
In cold climates and the like, the water in the hopper is usually drained in order to prevent the water in the hopper from freezing when hot water is not supplied to the bathtub.

However, in the above-described backflow prevention device, since the water flow sensor is provided on the upstream side of the backflow prevention solenoid valve, water is not drained at the location of the water flow sensor, and therefore the location of the water flow sensor is not provided. If the water in the water freezes, so does the water flow sensor. When the water flow sensor freezes in this way, the water flow sensor is damaged,
Alternatively, the backflow prevention device may become inoperable, and the backflow prevention device may not function normally when water is next passed through the water passage.

[0014]

DISCLOSURE OF THE INVENTION The present invention solves the above inconvenience, and in a backflow prevention device that detects a backflow in a water passage by a water flow sensor and blocks the backflow in response to the detection, a pressure plate of the water flow sensor. To provide a backflow prevention device that can configure an impeller, an impeller, or the like with an inexpensive, lightweight resin or the like, can ensure its operation, and can reliably prevent backflow in a water passage. With the goal.

[0015]

In order to achieve such an object, the present invention provides a hopper provided in the middle of a water passage,
A drainage channel derived from the hopper via a first on-off valve, a second on-off valve provided on the upstream side of the hopper in the middle of the water passage, the first on-off valve and the second on-off valve. Provided inside the water passage or hopper at a point between the valves,
A water flow sensor for detecting a backflow in the water passage, and a control means for opening the first on-off valve and closing the second on-off valve when the water flow sensor detects a backflow. ..

[0016]

According to the present invention, normally, water is supplied from the upstream side of the water passage to the downstream side of the water passage through the second on-off valve and the hopper.

In this case, since the water flow sensor is on the downstream side of the second on-off valve, the pressure on the upstream side of the water passage can be applied to the water flow sensor by closing the second on-off valve when water is not flowing. It is not given directly. Therefore, the pressure receiving plate and the impeller of the water flow sensor can be made of a resin material having a relatively low pressure resistance.

When water or hot water in the water passage tries to flow back from the downstream side of the water passage to the upstream side of the water passage via the hopper, the back flow is detected by the water flow sensor. The control means closes the second on-off valve and opens the first on-off valve, whereby water or hot water on the downstream side of the water passage is transferred through the hopper and the first on-off valve. It will be discharged to the drainage channel.

Further, the water flow sensor includes a first opening / closing valve and a second opening / closing valve.
Since it is provided between the on-off valve and
If the water is discharged into the hopper through the drainage channel, the water at the location of the water flow sensor is also discharged.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the backflow prevention device of the present invention is shown in FIGS.
Follow the instructions below. FIG. 1 is an explanatory configuration diagram of a hot water supply system for a bathtub to which the backflow prevention device is applied, FIG.
(B) is an explanatory configuration diagram of a main part of the backflow prevention device.

In FIG. 1, reference numeral 1 is a water passage extending from the water supply 2 to the bathtub 3, and 4 is a backflow prevention device.
A heat exchanger 5, a water solenoid valve 6, a main body portion 7 (details of which will be described later) of the backflow prevention device 4, and a check valve 8 are provided in this order from the upstream side (the water supply 2 side) to the downstream side (the bath 3 side). Has been. Further, a drainage channel 9 is led out from the main body section 7.

In the following description, the water passage 1 on the upstream side of the main body portion 7 will be referred to as the upper circulation water passage 1a, and the water passage 1 on the downstream side of the main body portion 7 will be referred to as the lower circulation water passage 1b.

The backflow prevention device 4 controls the main body portion 7 provided in the middle of the water passage 1, an on-off valve described later provided in the main body portion 7, a heat exchanger 5, a water solenoid valve 6 and the like. The controller 10 as a control means is provided.

More specifically, as shown in FIGS. 2 (a) and 2 (b), the main portion of the main body portion 7 is composed of a hopper 11, and the main wall of the main portion 7 is a through hole provided in the upper wall portion of the hopper 11. The upper circulation water passage 1a is connected to the water hole 12, and the lower circulation water passage 1b is connected to the water passage hole 13 formed in the bottom wall of the hopper 11. Further, the drainage channel 9 is connected to the drainage hole 14 formed in the side wall of the hopper 11.

Further, the main body portion 7 is provided with a first opening / closing valve 15 for opening / closing the drain hole 14, and a second opening / closing valve 16 for opening / closing the water passage hole 12. In this case, these on-off valves 1
5, 16 by the controller 10 (see FIG. 1),
It is opened and closed via a solenoid (not shown). Then, as shown in FIG. 2B, at the normal time (when the hot water supply system is stopped, etc.), the opening / closing valve 15 is driven to the open position for opening the drainage hole 14, and the opening / closing valve 16 opens the water passage hole 12. It is driven to a closed position to close it.

Further, the main body portion 7 is provided with a water flow switch 17 which is a water flow sensor provided in an upper portion inside the hopper 11 so as to substantially face the water passage hole 12. In this case, the water flow switch 17 swings around the support shaft 18 due to the water pressure when water or hot water flows back from the lower flow channel 1b to the upper flow channel 1a via the hopper 11 as described later. The pressure receiving plate 19 is provided, and the backflow of water or hot water is detected by the swing of the pressure receiving plate 19 and the detection signal is output to the controller 10.

In this case, the pressure receiving plate 19 is made of a lightweight material such as a resin material.

Next, the operation of the hot water supply system will be described.

1 and 2 (a), when hot water is supplied to the bathtub 3, first, the controller 10 opens the solenoid valve 6 for water, and then the opening / closing valve 16 of the backflow prevention device 4 is opened and closed. The valve 15 is closed, the heat exchanger 5 is activated,
As a result, from the water supply 2 to the upper distribution water channel 1a and the hopper 1
Water is supplied to the bathtub 3 through the first and the lower circulation water passages 1b in this order, and the water is supplied to the bathtub 3 by being heated by the heat exchanger 5.

At this time, when the water solenoid valve 6 is opened, the high-pressure water pressure of the waterworks 2 acts on the upper distribution water passage 1a up to the position of the water passage hole 12 of the hopper 11, but the water passage hole 12 opens and closes. Since it is blocked by 16, high-pressure water pressure is not applied to the water flow switch 17 inside the hopper 11. Then, after the water solenoid valve 6 is opened, as shown in FIG. 2A, when the opening / closing valve 16 is opened, the inside of the hopper 11 is opened to the bathtub 2 via the lower circulation water passage 1b. Therefore, the water flowing from the upper flow channel 1a to the lower flow channel 1b via the hopper 11 has a relatively low pressure, and the water pressure acting on the water flow switch 17 also has a low pressure.

During the hot water supply, the on-off valve 15 is closed, so that the water or hot water in the hopper 11 does not flow into the drainage channel 9.

On the other hand, for example, when the bathtub 3 is installed at a high place, when the water supply 2 is cut off during the hot water supply, the upstream side of the water passage 1 (the water supply 2 side) becomes a low pressure. Therefore, the water or hot water in the bathtub 3 tries to flow back through the water passage 1.

In this case, normally, this backflow is blocked by the check valve 8 provided in the lower distribution water passage 1b, but when the check valve 8 malfunctions or malfunctions, the water in the bathtub 3 is drained. The hot water tries to flow backward from the lower flow channel 1b to the upper flow channel 1a side through the hopper 11.

At this time, however, such a backflow is detected by the controller 10 when the pressure receiving plate 19 of the water flow switch 17 inside the hopper 11 oscillates. As shown in b), the on-off valve 16 of the water passage hole 12 is closed and the on-off valve 15 of the drain hole 14 is opened.

Therefore, from the lower distribution water channel 1b to the hopper 1
The water or hot water flowing back into the inside of the hopper 1 is prevented from flowing back from the inside of the hopper 11 to the upper circulation water passage 1a by the on-off valve 15, while being discharged from the inside of the hopper 11 into the drainage passage 9 through the discharge hole 14, , Upper distribution channel 1a from inside the hopper 11
Also, there is no backflow to the water supply 2.

Then, for example, in such a state, when the water supply of the water supply 2 is released, the high-pressure water of the water supply abruptly flows into the upper distribution water channel 1a, but the opening / closing valve 16 causes the water to enter the hopper 11. Since the inflow is blocked, the high-pressure water pressure does not act on the water flow switch 17.

In the above-described backflow prevention operation, since the pressure receiving plate 19 of the water flow switch 17 is made of a lightweight material such as a resin material, the water flow switch 17 responds to the backflow with good sensitivity. Therefore, backflow to the upper distribution water pipe 1a and the water supply 2 is also promptly blocked. As described above, since the high-pressure water pressure does not act on the water flow switch 17, the water flow switch 17 does not have to operate as in this embodiment.
There is no problem even if the pressure receiving plate 19 is made of resin.

Further, in such a hot water supply system, the water flow switch 17 is provided with the open / close valve 16 which is normally closed.
Since it is installed inside the hopper 11 on the downstream side of
When this system is stopped, the hopper 11 is fed through the drainage channel 9.
Since water at the position of the water flow switch 17 is also removed by draining the water inside, the water flow switch 17 is prevented from freezing and being damaged or becoming inoperable in cold regions. To be done.

Next, another example of the backflow prevention device of the present invention will be described with reference to FIGS. FIG. 3 is an explanatory configuration diagram of a main part of the backflow prevention device.

In FIGS. 1 and 3, the backflow prevention device 20 is shown.
Is provided in place of the backflow prevention device 4 in the hot water supply system, and like the backflow prevention device 4, a portion between the water electromagnetic valve 6 and the check valve 8 in the water passage 1. It is composed of a main body portion 21 provided in the above and a controller 22 which is a control means.

In this case, as shown in FIGS. 3 (a) and 3 (b), the auxiliary water passage 2 communicating with the inside of the hopper 23 from the upper wall of the hopper 23 which constitutes the main part of the main body 21.
4 is led out, and the upper distribution water passage 1a is connected to the water passage hole 25 formed in the side wall of the upstream end portion of the auxiliary water passage 24. In addition, the water passage hole 2 formed in the bottom wall of the hopper 23.
The lower circulation water passage 1b is connected to the drainage passage 6, and the drainage passage 28 is connected to the discharge hole 27 formed in the side wall of the hopper 23.

A first opening / closing valve 29 and a second opening / closing valve 30 for opening and closing the drain hole 27 and the water passage hole 25 under the control of the controller 22 are provided at the positions. The on-off valve 29 and the on-off valve 30 are normally driven to the open position and the closed position, respectively, as in the backflow prevention device 4 described above.

A flow rate sensor 31, which is a water flow sensor, is provided at an intermediate portion of the auxiliary water passage 24 that is in constant communication with the inside of the hopper 23.

In this case, the flow rate sensor 31 has a rotatable impeller 32, and when a reverse flow occurs in the water passage 1, the impeller 32 is rotated in a predetermined direction by its water pressure, and The backflow is detected and the detection signal is output to the controller 22. The impeller 32 of the flow rate sensor 31 is made of a lightweight material such as a resin material.

Next, the operation of the hot water supply system including the backflow prevention device 20 will be described.

In FIGS. 1 and 3 (a), hot water is supplied to the bathtub 3 in exactly the same manner as in the above case.

That is, first, after the water solenoid valve 6 is opened, the opening / closing valve 30 of the backflow prevention device 20 is opened and the opening / closing valve 29 is closed, and further the heat exchanger 5 is operated, whereby the water supply 2 From upper distribution channel 1a, hopper 23
And hot water is supplied to the bathtub 3 through the lower distribution water passage 1b in order. Then, at this time, as in the case described above, since the flow rate sensor 31 is provided on the downstream side of the on-off valve 30, when the water solenoid valve 6 is opened, a high pressure water pressure acts on the flow rate sensor 31. There is no such thing.

On the other hand, when the water supply 2 is cut off during hot water supply, water or hot water in the bathtub 2 is lifted from the lower distribution water passage 1b through the hopper 23 due to malfunction of the check valve 8 or malfunction. When an attempt is made to backflow to the side of the distribution water channel 1a, the impeller 32 of the flow rate sensor 31 inside the auxiliary water channel 24 rotates in a predetermined direction, so that this backflow occurs.
Detected by. Then, in response to the detection, the controller 10 closes the opening / closing valve 30 of the water passage hole 25 and opens the opening / closing valve 29 of the drain hole 27 as shown in FIG. 3B.

Therefore, the lower circulating water can 1b to the hopper 2
3 and the water flowing back into the auxiliary water passage 24 are
The on-off valve 30 prevents the backflow from inside 4 to the upper distribution waterway 1a, while it is discharged from the inside of the hopper 23 to the drainage path 28 through the discharge hole 27, and thus flows back to the upper distribution waterway 1a and the waterworks 2. There is no such thing.

Then, for example, in such a state, when the water supply of the water supply 2 is released, the high-pressure water of the water supply abruptly flows into the upper distribution water passage 1a, but the opening / closing valve 30 causes the water to flow to the sub water passage 24. Since the inflow is blocked, the high pressure water pressure does not act on the flow rate sensor 31.

In the above-described backflow prevention operation, since the impeller 32 of the flow sensor 31 is made of a lightweight material such as a resin material, the flow sensor 31 responds to backflow with high sensitivity, Therefore, backflow to the upper distribution water pipe 1a and the water supply 2 is also promptly blocked. Further, as described above, since high-pressure water pressure does not act on the flow rate sensor 31, there is no problem even if the impeller 32 of the flow rate sensor 31 is made of resin.

Further, in such a hot water supply system, since the flow rate sensor 31 is provided in the hopper 23 at the downstream side of the opening / closing valve 30 which is normally closed, it is always provided with the auxiliary water passage 24. If the inside of the hopper 23 is drained through the drainage channel 28 when the system is stopped, the water in the position of the flow rate sensor 31, that is, the sub-water channel 24 is also removed, so that the flow rate is reduced in a cold region or the like. It is also prevented that the sensor 31 is frozen, damaged, or inoperable.

[0053]

As is apparent from the above description, according to the present invention, the drainage channel is led out from the hopper provided in the middle of the water channel via the first opening / closing valve, and the drainage channel is provided on the upstream side of the hopper. A second opening / closing valve is provided in the middle of the water passage, and a water flow sensor for detecting a backflow in the water passage is provided inside the water passage or the hopper between the two opening / closing valves, and the backflow is detected by the water flow sensor. When the first means by the control means
By opening the on-off valve and closing the second on-off valve, it is possible to prevent the high-pressure water pressure of the waterworks or the like from acting on the water flow sensor. The configuration can be made of inexpensive and lightweight resin or the like.

By thus constructing the pressure receiving plate and the impeller of the water flow sensor with a light resin,
The responsiveness can be good, and therefore the backflow in the water passage can be detected quickly and prevented.

Further, since the water flow sensor is provided at a position between the on-off valves, if water is drained through the hopper, the water at the position of the water flow sensor is also removed.
It is possible to prevent the water flow sensor from freezing in cold regions and the like, and thus to ensure the operation of the water flow sensor.

[Brief description of drawings]

FIG. 1 is an explanatory configuration diagram of a hot water supply system for a bathtub, which is provided with an example of a backflow prevention device of the present invention;

FIG. 2 is an explanatory configuration diagram of a main part of an example of a backflow prevention device of the present invention,

FIG. 3 is an explanatory configuration diagram of a main part of another example of the backflow prevention device of the present invention.

[Explanation of symbols]

1 ... Water passage, 4, 20 ... Backflow prevention device, 9, 28 ... Drainage path, 10, 22 ... Controller (control means) 11,
3 ... Hopper, 15, 29 ... First on-off valve, 16, 30
... second on-off valve, 17 ... water flow switch (water flow sensor),
31 ... Flow rate sensor (water flow sensor).

Claims (1)

Claims: 1. A hopper provided in the middle of a water passage, a drainage path led out from the hopper via a first opening / closing valve, and a middle of the water path upstream of the hopper. A second on-off valve provided in the, and provided inside the water passage or the hopper at a position between the first on-off valve and the second on-off valve,
A water flow sensor for detecting a backflow in the water passage, and a control means for opening the first on-off valve and closing the second on-off valve when the water flow sensor detects a backflow. Backflow prevention device for water passage.