JPH09392U - Backflow prevention device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a backflow preventive device having excellent check valve opening response when filling water from the water heater side to the bathtub. [Structure] A valve hole passage 24 for introducing hot water from the water heater side into the room is provided above the check valve accommodating chamber 16. An intake valve hole 41 is provided in the bottom wall of the check valve accommodating chamber 16, and an outlet passage 45 is provided at a side portion of the check valve accommodating chamber 16. A valve hole passage 24 is provided in the check valve accommodating chamber 16.
The check valve 26 for opening and closing and the atmosphere opening valve 42 for opening and closing the atmosphere valve hole 41 are housed. The check valve 26 and the atmosphere release valve 42 are connected,
The opening / closing operation of the check valve 26 and the closing / opening operation of the atmosphere opening valve 42 are linked. On the upper side of the valve body 28, a tapered cone-shaped cone 29 is formed.
The seal member 30 is attached to the base side of the cone portion 29. The cone portion 29 is configured to be inserted into the valve hole passage 24 in the state where the seal member 30 closes the check valve valve seat 31.
The passage 45 at the outlet is formed below the closing operation position of the atmosphere opening valve 42.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a backflow prevention device provided on a hot water supply passage for dropping hot water of a water heater into a bathtub to prevent backflow from the bathtub side to the water heater side.

[0002]

[Prior art]

 As is well known, a hot water supply system for a bath is constructed by branching a hot water supply pipe of a water heater and connecting one of the hot water supply pipes to a reheating circulation line of a bath kettle through the branch pipe and the reheating circulation pipe. It is used to fill the bath automatically by filling it in the bathtub. Normally, this hot water supply system is equipped with a backflow prevention device that prevents the water on the bath side from flowing back to the water heater side.

FIG. 4 shows a hot water supply system for a bath provided with a backflow prevention device. In the figure, the bathtub 1 is provided with a reheating circulation pipe line 4 that sucks hot and cold water in the bathtub 1 by a circulation pump 2 and returns it to the bathtub 1 through a reheating heat exchanger 3 and cold water is provided on the water heater side. A hot water supply pipe 7 is provided which heats the water supplied from the pipe 5 by the hot water supply heat exchanger 6 and sends the hot water obtained by this heating to a desired place. The hot water supply pipe 7 and the additional heating circulation pipe line 4 are connected via a solenoid valve 10, a hopper 11 as a backflow prevention means, and a check valve 12, and when the bathtub 1 is filled with hot water, the hot water supply pipe 7 Through the solenoid valve 10, the hopper 11, and the check valve 12 in this order, the hot water is dropped into the bathtub 1 from the reheating circulation line 4. The hopper 11 completely separates the hot water supply pipe 7 from the reheating circulation pipe line 4 and completely blocks the hot water from the bathtub 1 side from flowing back to the hot water supply pipe 7 side.

[0004]

[Problems to be solved by the device]

 However, since this former backflow prevention device is composed of the hopper 11, when supplying hot water from the water heater side to the reheating and circulating pipe line 4 side, the water pressure on the solenoid valve 10 side does not reverse. Since it was not directly added to the conduit on the valve 12 side, the filling speed slowed down and there was the inconvenience that it took a long time to complete the filling.

The present invention has been made in order to solve the above-mentioned conventional problems, and the purpose thereof is to make it possible to suitably perform hot water filling by using tap water pressure, and the hot water of the bathtub side to the hot water supply pipe side. It is an object of the present invention to provide a backflow prevention device that can reliably prevent backflow.

[0006]

[Means for Solving the Problems]

 The present invention is configured as follows to achieve the above object. That is, the first invention is a backflow prevention device with a built-in check valve for preventing backflow from the bathtub side to the water heater side, which is provided on the hot water supply passage for supplying hot water from the water heater side to the bathtub. The valve is arranged in the check valve storage chamber provided in the hot water supply passage, and the check valve storage chamber is provided with a valve hole passage for introducing hot water from the water heater side. A valve seat for a check valve is provided on the terminal end side, and the check valve consists of a seal provided on the valve body, and the tip side of the valve body has a tapered divergent cone shape. A cone portion is formed, and a seal member that abuts the check valve valve seat and closes the valve hole passage is disposed on the outer peripheral surface of the base portion of the cone portion in the vicinity of the seal member arrangement portion. An overhanging wall that extends from the base of the cone part of the check valve in the direction orthogonal to the valve hole passage is in the interior space of the check valve accommodating chamber. When the seal member is extended, and the seal member is in contact with the check valve valve seat, the cone portion on the tip side of the seal member is inserted into the valve hole passage to check the valve hole passage. The cross section of the passage is narrowed toward the valve containment chamber, and the seal member of the check valve is inserted between the check valve and the wall surface of the check valve accommodating chamber to the check valve valve seat of the valve hole passage. A spring for pressing and urging the spring is installed.This spring urges the check valve to close the valve hole passage, and when hot water is supplied to the bathtub, the check valve is pushed down by the hot water supply pressure. A means to solve the problem is to open the passage and send hot water from the outlet of the check valve storage chamber to the bathtub side.

In a second aspect of the invention, which has the structure of the first aspect of the invention, the valve hole passage is provided on the upper side of the check valve accommodating chamber, and on the bottom wall side of the check valve accommodating chamber. An intake valve hole communicating with the atmosphere is provided at a position facing the valve hole passage, and an atmosphere opening valve for opening and closing the intake valve hole is connected to the check valve below the check valve in the check valve housing chamber. The check valve is freely movable up and down, and the upward movement of the check valve causes the check valve to close the valve hole passage and the atmosphere release valve to open the intake valve hole. The problem is solved by having the structure in which the valve hole passage is opened by the check valve and the intake valve hole is closed by the atmosphere release valve by the downward movement of the valve.

Further, in a third aspect of the invention, which has the configuration of the second aspect of the invention, the passage connected to the outlet of the check valve storage chamber and sending hot water to the bathtub side is formed by the atmosphere release valve. The structure provided below the closed position of the intake valve hole is a means to solve the problem.

[0009]

[Action]

 In the present invention having the above-mentioned structure, when the hot water is dropped into the bathtub from the hot water supply side, the hot water from the hot water supply side enters the valve hole passage and receives the hot water supply pressure, and the check valve causes the check valve to urge the spring. As a result of pushing down the check valve against the heat, hot water from the water heater side enters the check valve housing chamber through the valve hole passage.

When the hot water enters, the conical portion of the valve body of the check valve inserted into the valve hole passage has a tapered diverging cone shape, so that the cross section of the valve hole passage accommodates the check valve. As a result of the narrowing toward the chamber, the water flow through the valve hole passage increases in velocity and increases in momentum toward the check valve accommodating chamber, and enters the gap between the check valve seat and the seal member. The check valve suddenly moves in the opening direction in the valve hole passage under the force of the water flow.

Then, the water flow entering the check valve accommodating chamber from the valve hole passage collides with the protruding wall of the check valve that is formed so as to protrude in a direction substantially orthogonal to the valve hole passage, and this collision force is generated. In response to this, the check valve is pushed down and moved in the opening direction of the valve hole passage, and the check valve works because the conical portion accelerates the water flow and the water flow collides with the overhanging wall. At the start of tensioning, the valve hole passage will be opened immediately in the rapid acceleration state, and the responsiveness of the opening operation of the check valve at the start of tensioning will be enhanced, and more suitable tap water pressure can be used to fill the hot water. It will be.

In addition, the intake valve hole is quickly closed by the atmosphere opening valve in conjunction with the opening operation of the valve hole passage for rapid acceleration of the check valve, so that the check valve is accommodated at the start of filling. The amount of water drained from the chamber through the intake valve hole can be reduced, and the waste of water due to drainage can be reduced.

When the filling operation is stopped, the check valve moves in the urging direction by the urging force of the spring, closes the valve hole passage, and the atmosphere opening valve operates as an intake valve in conjunction with the movement of the check valve. Since the hole is opened, air enters the check valve housing chamber through the intake valve hole, resulting in atmospheric pressure, which separates the water heater side from the bath side, and even if the check valve fails, the bath The backflow from the side to the water heater side is prevented.

[0014]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of this embodiment, the same parts as those in the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 shows an embodiment of a backflow prevention device according to the present invention together with the system configuration of an automatic bathtub, and FIG. 2 shows an enlarged detailed view of a valve mechanism portion of the backflow prevention device in the same embodiment. It is shown. In these figures, the check valve is formed in the check valve storage chamber 16, and the check valve storage chamber 16 is integrally connected to the main valve chamber 15, the drainage chamber 17, and the discharge valve chamber 18. Are formed into a unit. In this embodiment, the check valve housing chamber 16 also functions as an edging chamber that separates the water heater side and the bathtub side.

The inlet passage 20 of the main valve chamber 15 is connected to the hot water supply pipe 7 of the water heater 21 via the pipe 9 on the upstream side of the hot water supply passage. A cylindrical wall that functions as a valve seat 23 projects upward from the top wall (bottom wall of the main valve chamber 15) 22 of the check valve accommodating chamber 16, and the valve hole passage 24 is provided above the valve seat 23. A pilot solenoid valve 25 that functions as a main on-off valve that opens and closes the inlet side of the is installed.

The check valve accommodating chamber 16 is provided below the main valve chamber 15, and the check valve accommodating chamber 16 is provided with a first check valve 26 and an atmosphere opening valve 27. .

The first check valve 26 has a valve body 28 that can move up and down along the inner wall surface of the check valve accommodating chamber 16, and the tip end (upper side) of this valve body 28 is O-shaped. A seal member 30 such as a ring is attached, and the seal member 30 abuts on an inclined wall surface 31 provided on the outlet side (terminal side) of the valve hole passage 24, and the valve body 28 moves up and down to open the valve hole. It is designed to open and close the exit of passage 24. The inclined wall surface 31 functions as a check valve valve seat 31.

On the tip side (upper side) of the valve body 28, a tapered cone portion 29 having a divergent cone shape is formed, and the seal member 30 is attached to the outer peripheral surface of the cone portion 29 on the base side. As shown in FIG. 2, the tip side of the cone portion 29 is inserted into the valve hole passage 24 while the seal member 30 is in contact with the check valve valve seat 31, and A cross section of the passage 24 is narrowed toward the check valve accommodating chamber 16. A projecting wall 39 projecting in the direction orthogonal to the valve hole passage 24 from the root of the cone portion 29 near the lower portion of the mounting portion of the seal member 30 is formed in the inner space above the check valve accommodating chamber 16 by extension. Has been done.

At the center of the valve body 28, there is provided a body portion 32 protruding downward, and a cylinder member 34 having a collar 33 is loosely fitted in the body portion 32 so as to be vertically slidable. A pilot valve hole 36 is formed at the center of the bottom wall 35 of the tubular member 34. The pilot valve hole 36 faces the lower end surface of the body portion 32 of the valve body 28, and a valve 37 is provided on this lower end surface, and the valve 37 allows the pilot valve hole 36 to be opened and closed. ing. An engagement piece 40 is provided so as to project inward from the peripheral wall side of the valve body 28. The engagement piece 40 engages with the flange 33 when the valve body 28 moves upward, The tubular member 34 is configured to be pulled upward by interlocking with.

A valve that functions as an atmosphere opening valve that opens and closes a valve hole 41 that functions as an intake valve hole that connects the check valve accommodating chamber 16 and the drainage chamber 17 to the lower end surface side of the bottom wall 35 of the cylindrical member 34. 42 is provided, and the valve hole 41 is closed by the valve 42 by the downward movement of the valve body 28. At this time, as shown in FIG. 3, a gap 43 is provided between the engaging piece 40 and the collar 33. It is formed. A spring 44 is disposed between the engagement piece 40 and the bottom wall of the check valve accommodating chamber 16, and the valve body 28 is normally urged upward by the restoring force of the spring 44 and the valve hole passage 24 The check valve valve seat 31 on the outlet side is closed by the seal member 30, and the valve hole 41 is opened in this state.

The discharge valve chamber 18 has an upper chamber 46 and a lower chamber 47 and is arranged adjacent to the check valve accommodating chamber 16 by a passage 45 extending laterally from the outlet of the check valve accommodating chamber 16. Communication between the check valve storage chamber 16 and the upper chamber 46 is achieved. A valve hole 50 is formed in the partition wall 48 of the upper chamber 46 and the lower chamber 47, and a negative pressure stop valve 51 is provided on the inlet side of the valve hole 50. A compression spring 53 is provided between the top walls 52 of the chambers 46, and the valve hole 50 is closed by a negative pressure stop valve 51 under the biasing force of the spring 53. On the other hand, the lower chamber 47 is provided with a second check valve 54 that opens and closes the outlet side of the valve hole 50. Similarly, a compression valve is provided between the second check valve 54 and the bottom of the lower chamber 47. The spring 55 is interposed, and the outlet side of the valve hole 50 is closed by the second check valve 54 by the urging force of the spring 55. The lower chamber 47 is connected to the reheating circulation line 4 via a hot water filling pipe 56 that constitutes the downstream side of the hot water supply passage. As shown in FIG. 2, the passage 45 is provided below (low) below the closing position of the intake valve hole 41 by the atmosphere opening valve 42.

A guide shaft 57 is projected upward from the bottom side of the drainage chamber 17 communicating with the check valve housing chamber 16 through the valve hole 41, and a float 58 slides on the guide shaft 57. It is fitted freely. A magnet (not shown) is attached to the float 58, and a reed switch (not shown) is provided on the wall surface of the drainage chamber 17, so that the float 58 receives buoyancy and rises to a preset water level. At this time, the magnet on the side of the float 58 and the reed switch face each other, and the reed switch outputs an ON signal for starting the circulation pump 2. The magnet on the side of the float 58 and the reed switch described above are output. A water level switch is formed by the switch. Further, an overflow pipe 60 protruding upward from the bottom wall side of the drainage chamber 17 is provided, and when the water level in the drainage chamber 17 exceeds the upper end of the overflow pipe 60, the overflow water (hot water) overflows. It is designed to be discharged through a tube 60.

Further, the inlet side of the drainage pipe 61 is communicated with the bottom wall of the drainage chamber 17, and the outlet side of the drainage pipe 61 is the return pipe 59 of the reheating circulation line 4, that is, the suction of the circulation pump 2. Is connected to the side pipeline. The drain pipe 61 is provided with a third check valve 62 and a solenoid valve 63 that functions as a first control opening / closing valve. Further, an electric two-way valve 64 as a second control opening / closing valve is provided in the return pipe 59 closer to the bathtub 1 side than the connection portion on the outlet side of the drainage pipe 61. In the figure, 65 is a flow rate sensor, 66 is a water amount control valve, 67 is a water level sensor (pressure sensor) that detects the water level in the bathtub 1 by pressure, and 68 is an additional heating water switch that detects the flow of additional heating water. Shown respectively.

The present embodiment is configured as described above, and its operation will be described next. First, when the inlet side of the valve hole passage 24 is opened by the opening operation of the pilot solenoid valve 25, the hot water supplied from the hot water supply pipe 7 side enters the valve hole passage 24, and the water pressure thereof causes the valve body 28 to spring. The outlet side of the valve hole passage 24 is opened by pushing down against the biasing force of 44.

During the opening operation of the outlet of the valve hole passage 24 by the first check valve 13, the cone portion 29 of the valve body 28 inserted into the valve hole passage 24 becomes a tapered divergent cone shape. Since the passage cross section becomes narrower toward the check valve storage chamber 16, the water flow entering the check valve storage chamber 16 is accelerated by flowing along the conical portion 29, and the water flow The momentum is increased, and the force of the increased water flow acts on the cone portion 29, so that the valve body 28 starts to descend in a rapid acceleration state due to the acceleration action of the water flow. Then, the vigorous water flow passing through the gap between the seal member 30 and the check valve valve seat 31 collides with the overhanging wall 39 of the valve body 28, so that the valve body 28 receives this collision force and moves downward. To accelerate further. As described above, in the present embodiment, the synergistic effect of the acceleration effect of the diverging slope of the cone portion 29 and the collision effect on the overhanging wall 39 causes the valve body 28 to suddenly start filling as soon as it is started. In the accelerated state, it descends to open the outlet of the valve hole passage 24.

By the downward movement of the valve body 28, the valve 37 also integrally moves downward and the pilot valve hole 36 is closed, and similarly, the valve hole 41 is closed by the downward movement of the valve 42, and the check valve is closed. The communication between the valve storage chamber 16 and the drainage chamber 17 is cut off. Due to this disconnection of the communication, the hot water entering the check valve housing chamber 16 pushes up the negative pressure stop valve 51 by the water pressure to enter the valve hole 50, and further the second check valve 54 resists the urging force of the spring 55. As a result, the outlet side of the valve hole 50 is opened downward, and as a result, the hot water enters the lower chamber 47 through the valve hole 50 and further enters the reheating circulation pipe line 4 through the hot water filling pipe 56, and this reheating circulation pipe The water is dropped into the bathtub 1 from both sides of the forward pipe 69 and the return pipe 59 of the passage by the water pressure.

When the water level of the water filling the bathtub 1 reaches the set water level, the closing operation of the valve of the pilot solenoid valve 25 closes (closes) the inlet side of the valve hole passage 24, so that the valve body 28 is closed. The upward biasing force of the spring 44 overcomes the force pushing downward due to water pressure, and the valve body 28 starts to move upward. At this time, a gap 43 is formed between the flange 33 of the tubular member 34 in which the valve 42 is formed and the engagement piece 40 on the valve body 28 side, as shown in FIG. Moves upward until the engagement piece 40 is locked to the collar 33, and the upward movement of the valve body 28 causes the valve 37 to move upward in conjunction with the upward movement of the valve body 28, so that the pilot valve hole 36 is opened first.

Then, as a result of the atmosphere on the drain chamber 17 side entering the check valve storage chamber 16 through the pilot valve hole 36, the check valve storage chamber 16 becomes atmospheric pressure, and the water pressure in the check valve storage chamber 16 is reduced. The closing force for pressing the valve hole 41 by the used valve 42 is released. When the valve body 28 continues to rise further due to the restoring force of the spring 44, the engaging piece 40 engages with the flange 33 and the tubular member 34 moves upward together with the valve body 28, so that the valve 42 also integrates. The valve hole 41 is completely opened, and the outlet side of the valve hole passage 24 is closed by the seal member 30 of the first check valve 26. At this time, the hot water filled in the check valve accommodating chamber enters the drain chamber 17 side through the valve hole 41. At this time, when the float 58 receives buoyancy and rises to the set position, an on signal is output from the lead switch. Then, the solenoid valve 63 is opened, the electric two-way valve 64 is closed, and the circulation pump 2 is started. Therefore, the water accumulated in the drainage chamber 17 passes through the drainage pipe 61, and then the circulation pump 2 operates. It is forcibly discharged into the bathtub 1 from the outward pipe 69 side of the reheating circulation line 4.

Simultaneously with the closing operation of the pilot solenoid valve 25, the negative pressure stop valve 51 closes the inlet side of the valve hole 50 by the urging force of the spring 53, and the air on the drain chamber 17 side closes the check valve accommodating chamber 16. Prevents entry through valve hole 50. The second check valve 54 also closes the outlet side of the valve hole 50 by the urging force of the spring 55 at the same time as the closing operation of the pilot solenoid valve 25, so that the wastewater from the reheating circulation line 3 side passes through the valve hole 50 and reverses. Prevent it from entering the stop valve accommodating chamber 16 side.

In the above embodiment, when the check valve accommodating chamber 16 is opened to the atmosphere, first, the valve 37 is moved upward in conjunction with the upward movement of the valve body 28 to open the pilot valve hole 36, and the check valve is opened. Since the accommodation chamber 16 is brought to atmospheric pressure, the engagement piece 40 and the collar 33 are engaged to move the valve 42 upward to open the valve hole 41. It can be used to open the valve hole 41. If the pilot valve hole 36 and the valve 37 are not provided, when the valve 42 is opened, the check valve accommodating chamber 16 has a higher pressure than the drainage chamber 17, so this pressure difference causes The valve 42 is pushed downward to act to close the valve hole 41, and when opening the valve hole 41, a spring 44 having a strong restoring force that overcomes the pressure difference must be used. When opening 25 and performing hot water filling, there is a problem that the valve 42 cannot be pushed down by using the water pressure of the hot water that has entered the valve hole passage 24 and the valve hole 41 cannot be closed. Further, by providing the pilot valve hole 36 and the valve 37, first opening the pilot valve hole 36 to eliminate the pressure difference, and then opening the valve hole 41, it is possible to reduce the restoring force of the spring 44. Yes, the restoring force of the spring 44 is increased. It is possible to solve the problems caused by the Rukoto.

Further, in the present embodiment, the tip end side (upper side) of the valve body 28 is formed into a tapered cone-shaped divergent cone 29, and the cone 29 is closed at the outlet of the valve hole passage 24. In this state, it is configured to be inserted into the valve hole passage 24, and the projecting wall 39 in the direction orthogonal to the valve hole passage 24 is provided from the root of the cone portion 29 near the lower side of the seal member 30. Therefore, at the start of filling, the water flow flowing from the valve hole passage 24 along the conical portion 29 of the valve body 28 is accelerated and the check valve accommodating chamber 16 is accelerated from the valve hole passage 24. Since the valve body 28 descends in a state of rapid acceleration (rapid start) due to the collision action of the water flow on the overhanging wall 39, the valve body 28 can be swiftly and reliably operated even when the amount of water in the hot water filling is small. It becomes possible to suitably perform the filling by tap water pressure.

Further, as described above, at the start of the filling of water, the valve element 28 receives a large pushing force due to the accelerating action of the water flow and the colliding action with the overhanging wall 39 and descends in a rapid acceleration state. Since the atmosphere opening valve 42 descends and closes the intake valve hole 41 within a short time, the first check valve 13 opens the check valve valve seat 31 to open the check valve housing chamber 16. It is possible to reduce the amount of water discharged from the intake valve hole 41 until the intake valve hole 41 is closed by the atmosphere release valve 42, and the amount of waste water discharged into the drain chamber 17 is reduced. It is possible to reduce. Therefore, even if the drainage chamber 17 is omitted, the amount of water discharged from the intake valve hole 41 to the outside at the start of filling can be reduced, and the problem that a large amount of water is discharged to the floor surface can be prevented. .

Further, in the present embodiment, since the passage 45 that connects the check valve storage chamber 16 and the upper chamber 46 of the discharge valve chamber 18 is provided below the outlet side closing surface of the valve hole passage 24, When filling water, the first check valve 26 can be easily pushed down by tap water pressure. If this passage 45 is provided above the closing surface of the first check valve 26, a stagnation part is formed on the upper side of the passage 45, and the pressure in the passage 45 becomes high, and this pressure becomes the first check valve. Since the valve 26 is closed, when the pilot solenoid valve 25 is opened and the hot water on the water heater side enters the valve hole passage 24, the tap water pressure of the hot water causes the first check valve 26, That is, it is difficult to push the valve body 28 downward, but as in the present embodiment, the passage 45 is below the closing surface of the first check valve 26 and below the closing position of the atmosphere release valve 42. By arranging it at a low position, the stagnation portion does not occur in the passage 45, and therefore, the force in the direction of closing the first check valve 26 from the passage 45 side is not generated, so that when the water is filled, the pressure of the passage of the hot water causes The first check valve 26 can be pushed down easily, making the filling operation smoother. It can be carried out to become.

Further, since the negative pressure stop valve 51 is provided in the discharge valve chamber, when the pilot solenoid valve 25 is closed to stop the water flow for the water filling, the negative pressure stop valve 51 is closed to make the water filling. It is possible to prevent air from entering the pipe 56. Therefore, when the water level sensor 67 is provided in the water filling pipe 56, the water level sensor 67 causes the water to enter the bathtub by the air entering the water filling pipe 56. It is possible to prevent the problem that the malfunction of the water level detection occurs.

Further, even when the bathtub 1 is provided above the appliance (hot water supply device), for example, when the hot water supply device is provided on the first floor of the household at 5 and the bathtub 1 is provided on the second floor of the household, The second check valve 54 prevents the sewage on the bath tank 1 side from entering the check valve housing chamber 16 side, which is safe for hygiene. In this case, even if a failure occurs in the first check valve 26 and the second check valve 54, and sewage on the bathtub 1 side enters the check valve storage chamber 16 side, this sewage is stored on the check valve storage side. When the water enters the drainage chamber 17 from the chamber 16 and the float 58 rises to a predetermined water level, an ON signal is output from the lead switch to start the circulation pump 2, close the electric two-way valve 64, and open the solenoid valve 63. As a result of the operation being performed, the sewage collected in the drainage chamber 17 is forcibly reheated by the circulation pump 2 and returned to the bathtub 1 side through the forward pipe 69 of the circulation pipeline 4, and the sewage on the bathtub 1 side is supplied to the hot water. There is no backflow to the vessel side. Further, in this case, even when the circulation pump 2 cannot be started due to a power failure or the like, when the water level of the waste water accumulated in the drainage chamber 17 exceeds the upper end opening of the overflow pipe 60, it is discharged to the outside from the overflow pipe 60. Therefore, in any case, the sewage side and the clean water side are surely cut off in the check valve accommodating chamber 16, and the sewage on the bathtub 1 side flows back to the water heater side on the clean water side. Is completely prevented.

The present invention is not limited to the above-mentioned embodiment, and various embodiments can be adopted.

[0037]

[Effect of the invention]

 According to the present invention, a tapered divergent cone-shaped cone portion is formed on the tip side of the check valve valve body, and the check valve is provided on the base end side of the valve hole passage that enters the check valve housing chamber from the water heater side. Since the cone portion is configured to be inserted into the valve hole passage with the valve opening of the stop valve seat closed, the hot water supply from the water heater side to the bathtub is started, and When hot water for hot water enters the check valve storage chamber from the valve hole passage, the passage cross section becomes narrower toward the check valve storage chamber, accelerating the flow velocity and increasing the force of the water flow. Will act on the valve body of the check valve. Moreover, since a projecting wall that is substantially orthogonal to the valve hole passage is formed on the base side of the cone portion, the accelerated water flow collides with the projecting wall that functions as this pressure receiving surface, and the water flow A large force that pushes down the valve body (check valve) is obtained by the synergistic effect of the acceleration of the flow velocity when the water passes through the cone and the collision of the water flow on the overhanging wall. Occasionally, the check valve is pushed down in the state of rapid acceleration (sudden start) to open the valve hole passage securely, and the responsive check valve opening operation at the start of filling is suitable for filling with tap water. It will be possible to do so.

Further, as described above, there is a synergistic effect of the accelerating action of the flow velocity when the water flow passes through the conical portion and the colliding action of the water flow entering the check valve accommodating chamber from the valve hole passage against the projecting wall. Even if the amount of filling water is small, the check valve can be pushed down with high responsiveness to open the valve hole passage and smooth the filling operation even when the amount of filling water is small. In addition, there is an effect that it can be surely performed.

Further, the valve hole passage is formed on the upper side of the check valve storage chamber, the intake valve hole is formed on the bottom wall of the check valve storage chamber, and the atmosphere release valve for opening and closing the intake valve hole is provided for the check valve. In the case of a structure in which the check valve is connected to the lower side and the opening of the valve hole passage by the check valve and the closing of the intake valve hole by the atmosphere opening valve are interlocked with each other, as described above, in the present invention, The synergistic effect of the acceleration of the water flow through the cone and the impact of the accelerated water flow entering the check valve housing chamber from the valve hole passage against the overhanging wall increases the push-down force of the check valve, resulting in a check. As a result of the valve being pushed down in the rapid acceleration state, the intake valve hole can be immediately closed by the atmosphere opening valve that descends in conjunction with the check valve, so that the check valve opens the valve hole passage before opening the atmosphere. It takes an extremely short time for the intake valve hole to be closed by the open valve. As a result, the amount of hot water that enters the check valve housing chamber from the time the valve hole passage is opened to the time the intake valve hole is closed can be reduced, and as a result, the water filling It is possible to effectively reduce the waste of the amount of water discharged from the intake valve hole at the start.

Further, the passage of hot water supplied from the outlet of the check valve accommodating chamber to the bath side is provided below the closing position of the intake valve hole by the atmosphere opening valve, so that the filling of water starts. At the same time, the position head of the passage on the outlet side of the check valve storage chamber becomes lower than the position head of the pressure receiving surface of the overhanging wall of the check valve. Since it is possible to prevent the pressure from acting as a drag force that prevents the check valve from moving downward, the check valve can be operated as described above without being affected by the head pressure of accumulated water in the passage on the outlet side of the check valve housing chamber. It can be pushed down in the rapid acceleration state to open the valve hole passage, and even with a small amount of water filling water, the check valve can be pushed down reliably to perform hot water filling, and it is also linked to the push-down movement due to the sudden acceleration of the check valve. Then, the atmosphere release valve is quickly lowered and the intake valve hole It has an excellent effect that the effect of being able to immediately close the valve and preventing wasteful discharge of water from the intake valve hole can be promoted.

Further, in the present invention, since the valve hole passage is closed by the check valve while the filling of water is stopped, the sewage on the bathtub side is prevented from flowing back to the tap water side on the water heater side. it can. In this case, even if the check valve breaks down and the water supply on the water heater side runs out of water, causing a negative pressure on the water heater side, an intake valve hole communicating with the atmosphere is provided in the check valve housing chamber. Therefore, while the hot water supply is stopped, the intake valve hole is maintained in the open state, so that the water heater side and the bathtub side are reliably separated from each other, and the backflow of dirty water from the bathtub side to the water heater side is ensured. Even if sewage on the bathtub side flows back to the check valve storage chamber, it will be discharged from the intake valve hole to the outside of the check valve storage chamber. There is no backflow of sewage to the side, which is safe for hygiene.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a backflow prevention device according to the present invention together with an automatic bathtub system.

FIG. 2 is a detailed explanatory diagram of an internal configuration of a unit of the backflow prevention device in the embodiment.

FIG. 3 is an explanatory diagram showing one operating state of the backflow prevention device in the embodiment.

FIG. 4 is an explanatory view of a system of an automatic bath heater that includes a former backflow prevention device.

[Explanation of symbols]

 16 Check valve accommodating chamber 24 Valve hole passage 26 First check valve 28 Valve body 29 Cone 31 Check valve seat 39 Overhang wall 41 Intake valve hole 42 Atmosphere release valve

Claims (3)

[Utility model registration claims] 1. A check valve with a built-in check valve for preventing backflow from the bathtub side to the water heater side, the check valve being provided on the hot water supply passage for supplying hot water from the water heater side to the bathtub. The check valve accommodating chamber is provided in the hot water supply passage, and the check valve accommodating chamber is provided with a valve hole passage for introducing hot water from the water heater side. Is provided with a non-return valve seat, and the non-return valve comprises a valve member provided with a seal member. A seal member that is formed and closes the valve hole passage by contacting the check valve valve seat is provided on the outer peripheral surface of the cone portion at the base side. A projecting wall projecting from the root in a direction orthogonal to the valve hole passage is provided so as to extend in the indoor space of the check valve housing chamber. With the seal member in contact with the check valve valve seat, the cone portion at the tip end side of the seal member is inserted into the valve hole passage, and the valve hole passage passes toward the check valve accommodating chamber. The cross-section is narrowed, and a spring is provided between the check valve and the wall surface of the check valve accommodating chamber to urge the seal member of the check valve into pressure contact with the valve seat for the check valve in the valve hole passage. The check valve is biased by the biasing force of this spring to close the valve hole passage, and when hot water is supplied to the bathtub, the check valve is pushed down by the hot water supply pressure to open the valve hole passage and open the outlet of the check valve accommodating chamber. A backflow prevention device configured to send hot water from the bath to the bathtub. 2. The valve hole passage is provided on the upper side of the check valve accommodating chamber, and the intake valve hole communicating with the atmosphere is provided on the bottom wall side of the check valve accommodating chamber at a position facing the valve hole passage. An atmosphere opening valve for opening and closing the intake valve hole is connected to the check valve below the check valve in the check valve accommodating chamber, and is vertically movable in association with the check valve. The upward movement of the stop valve closes the valve hole passage by the check valve and the opening of the intake valve hole by the atmosphere opening valve, and the downward movement of the check valve opens the valve hole passage by the check valve and intake by the atmosphere opening valve. The backflow prevention device according to claim 1, wherein the valve hole is closed. 3. A passage, which is connected to the outlet of the check valve accommodating chamber and sends out hot water for supplying hot water to the bathtub side, is provided below the closing position of the intake valve hole by the atmosphere opening valve. Backflow prevention device.