Hot water filling control device

Abstract

To avoid hot water which should be discharged through an atmosphere release passage during water cut-off or the like flowing back to a water heater side while facilitating water drainage by a bathtub cut-off control device.SOLUTION: An electromagnetic valve 31 is arranged in a hot water passage 20 which directs hot water from a water heater to a bathtub, and a filter 33 is arranged on the water heater side relative to the electromagnetic valve, with two check valves 34, 35 being serially arranged on the bathtub side relative to the electromagnetic valve. An atmosphere release valve 37 is also arranged in an atmosphere release passage 36 branched from between the two check valves. The atmosphere release valve is closed against an energization force of a valve-opening spring by receiving the pressure of tap water via a tap water pressure passage 18 branched from a water supply passage which directs tap water to the water heater. A communication passage 38 is connected so that air flowing in from a drain tap which is opened at the time of drainage of the water supply passage and the tap water pressure passage can be introduced between the upstream-side check valve 34 and the filter, and an air flow-in valve 39 which can open and close the communication passage is provided. The air flow-in valve is energized in a valve-opening direction and is closed by receiving the pressure of tap water in a tap-closed state of the drain tap.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a hot water filling control device provided in a hot water supply passage that guides hot water from a water heater to a bathtub and controls the hot water filling of the bathtub. Specifically, it relates to a technique for draining water from the hot water filling control device as the water heater is drained.

Background Art

[0002] In a system for filling a bathtub with hot water generated by a water heater, a hot water filling control device for controlling the hot water filling is provided in a hot water supply passage that guides hot water from the water heater to the bathtub. This hot water filling control device includes a solenoid valve, a filter, a check valve, etc. The solenoid valve can open and close the hot water supply passage. The hot water filling starts when the solenoid valve opens, and the hot water filling stops when the solenoid valve closes. The filter is provided upstream of the solenoid valve (on the water heater side) to remove foreign substances mixed in the hot water from the water heater and prevent foreign substances from getting stuck in the solenoid valve. The check valve is provided downstream of the solenoid valve (on the bathtub side) and is biased in the valve closing direction to close the hot water supply passage. When the pressure of the hot water supplied from the water heater exceeds a predetermined valve opening pressure due to the opening of the solenoid valve, the check valve opens to allow the hot water to pass through. On the other hand, when the pressure of the city water decreases due to reasons such as water cut-off during hot water filling, the pressure of the hot water supplied from the water heater decreases, causing the check valve to close, so that the backflow of hot water from the bathtub side to the water heater side through the hot water supply passage can be prevented. And by installing two check valves in series, it is possible to more reliably prevent the backflow of hot water than in the case of one check valve.

[0003] Furthermore, in such bathtub filling control devices, there is a known design in which an atmospheric release valve is installed in an atmospheric release passage that branches off from between two check valves in the hot water supply passage. The atmospheric release valve is biased in the opening direction by an opening spring, and is connected to a water supply pressure passage that branches off from the water supply passage that supplies tap water to the hot water supply device. The pressure from the tap water through the water supply pressure passage causes it to remain closed against the biasing force of the opening spring. When the water pressure drops due to a water outage or other reason, the biasing force of the opening spring opens the atmospheric release valve, and the hot water between the two check valves is discharged and replaced by air flowing in from the atmospheric release valve. Therefore, even if the check valves are not completely closed, backflow of hot water from the bathtub to the hot water supply device can be prevented. In addition, the atmospheric release valve also opens when the water supply to the hot water supply device is stopped by closing the shut-off valve in the water supply passage, so it can be used to drain the bathtub filling control device.

[0004] However, when draining the water from the hot water supply control device, the water between the filter and the upstream (solenoid valve side) check valve may be difficult to drain and remain for the following reasons. First, when draining the water, even if the solenoid valve is opened, the check valve remains closed, and air flowing in from the atmospheric release valve does not pass through the upstream check valve to the solenoid valve side (atmospheric pressure does not act). On the other hand, when the water is drained from the upstream side of the filter (hot water supply device side) along with the water supply system, atmospheric pressure acts on the water downstream from the upstream side of the filter. Also, the fine mesh of the filter creates surface tension in the water, making it difficult for air to enter from the upstream side. Therefore, between the filter and the upstream check valve, even if the water tries to flow out from the filter side, there is no inflow of air to replace it, and the weight of the water is supported by the surface tension of the water in the filter and the atmospheric pressure acting from the upstream side of the filter. As a result, the water between the filter and the upstream check valve remains trapped.

[0005] Therefore, it has been proposed to connect a communication passage between the filter of the hot water supply passage and the upstream check valve, which connects to an atmospheric vent passage, and to install an air inlet valve in this communication passage (Patent Document 1). Although the air inlet valve is biased in the opening direction, if hot water is supplied from the hot water supply device, it is closed due to the pressure of the hot water from the hot water supply passage side. When draining the water, the air inlet valve opens as the pressure of the hot water from the hot water supply device decreases, and the hot water between the filter and the upstream check valve can be replaced by air introduced from the atmospheric vent valve through the communication passage. This breaks the surface tension of the water in the filter, causing the hot water to flow out and enabling draining of the hot water supply control device. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-046990 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in a hot water supply control device with the above-described configuration, there was a problem in that when the check valve was not completely closed and hot water flowing back from the bathtub side was discharged from the atmospheric release valve through the atmospheric release passage, the air inlet valve was open, which meant that hot water could flow from the atmospheric release passage through the communication passage between the filter and the upstream check valve and backflow to the hot water supply device side.

[0008] This invention addresses the aforementioned problems in the prior art and aims to provide a technology that facilitates the draining of water from a hot water supply control device while preventing hot water, which should be discharged through an atmospheric vent passage in the event of a water outage, from flowing back into the hot water supply device. [Means for solving the problem]

[0009] To solve the above-mentioned problems, the hot water filling control device of the present invention employs the following configuration. That is, In a hot water supply passage that guides hot water from a hot water supply device to a bathtub, and in a hot water filling control device that controls the filling of the bathtub, A solenoid valve for opening and closing the hot water supply passage, A filter is provided on the hot water supply side of the solenoid valve to remove foreign matter from the hot water supply device, Two check valves are provided in series on the bathtub side of the solenoid valve, biased in the closing direction to close the hot water supply passage, and open when the pressure of the hot water supplied from the hot water supply device exceeds a predetermined opening pressure. An atmospheric release valve is provided that can be opened and closed, which branches off from between the two check valves in the hot water supply passage, and which, when it receives the pressure of tap water via a tap water pressure passage branched off from the water supply passage that leads tap water to the hot water supply device, closes against the biasing force of the valve opening spring, and when the tap water pressure decreases, opens due to the biasing force of the valve opening spring to discharge the hot water between the two check valves. Air flowing in from the drain valve, which is opened when the water supply passage and the water pressure passage are drained, is introduced through a communication passage connected between the upstream check valve on the solenoid valve side of the two check valves and the filter. The aforementioned communication passage is provided so as to be openable and closable, and is biased in the opening direction, and the air inlet valve closes when it receives the pressure of the water supply when the drain valve is closed. It is characterized by having the following features.

[0010] In the bath filling control device of the present invention, if tap water is supplied to the hot water supply device, the pressure of the tap water causes the atmospheric release valve and the air inlet valve to close, so that hot water from the hot water supply device does not flow through the atmospheric release passage or the communication passage, and the bathtub can be filled with hot water by opening the solenoid valve. When draining the water from the hot water supply device, opening the drain valve discharges the water from the water supply passage and the tap water pressure passage, and as air flows in from the drain valve, the air inlet valve opens, and air is introduced between the upstream check valve and the filter through the communication passage (atmospheric pressure acts on it). As a result, the surface tension of the water in the filter is no longer sufficient to support the weight of the hot water between the upstream check valve and the filter, so the surface tension is broken and the hot water flows out, making it possible to easily drain the water. Furthermore, if the check valve is not fully closed during a water outage or other incident, and hot water flows back from the bathtub side, the hot water will be discharged from the atmospheric vent valve through the atmospheric vent passage. However, since the atmospheric vent passage and the communication passage are completely independent, it is possible to prevent the hot water that should be discharged through the atmospheric vent passage from flowing back to the hot water supply system.

[0011] In the hot water supply control device of the present invention described above, the following may also be used. First, the atmospheric release valve is divided into a primary chamber and a secondary chamber by a diaphragm, with the water supply pressure passage connected to the primary chamber and the atmospheric release passage connected to the secondary chamber. Furthermore, the diaphragm is biased toward the primary chamber by an opening spring, and when water pressure is applied to the primary chamber via the water supply pressure passage, the diaphragm is pushed into the secondary chamber, thereby closing the valve. The communication passage has one end connected between the upstream check valve and filter of the hot water supply passage, and the other end connected to the primary chamber of the atmospheric release valve.

[0012] In this way, when the water in the water supply passage and the water pressure passage are discharged by opening the drain valve, the air inlet valve opens, and air flowing in from the drain valve is introduced between the upstream check valve and the filter through the water pressure passage, primary chamber, and communication passage, making it possible to easily drain water between the upstream check valve and the filter of the hot water filling control device. Furthermore, it becomes possible to unitize the hot water filling control device as an integrated unit, including the filter, solenoid valve, two check valves, and the atmospheric release valve of the atmospheric release passage, as well as the air inlet valve of the communication passage. [Brief explanation of the drawing]

[0013] [Figure 1] This is an explanatory diagram showing the overall configuration of the hot water filling system 1 equipped with the hot water filling control device 30 of this embodiment. [Figure 2] This is an explanatory diagram conceptually showing the configuration of the hot water filling control device 30 in this embodiment. [Figure 3] This is a cross-sectional view showing the detailed structure of the atmospheric release valve 37 in this embodiment. [Figure 4] This is an explanatory diagram showing the detailed structure of the air inlet valve 39 in this embodiment. [Figure 5] This is an explanatory diagram showing how to drain water from a conventional hot water filling control device 30 that does not have a communication passage 38 or an air inlet valve 39. [Figure 6] This is an explanatory diagram showing how water is drained from the hot water filling control device 30 in this embodiment. [Figure 7] This is an explanatory diagram conceptually showing the configuration of the comparative example's hot water filling control device 30. [Modes for carrying out the invention]

[0014] Figure 1 is an explanatory diagram showing the overall configuration of the bath filling system 1 equipped with the bath filling control device 30 of this embodiment. As shown in the figure, the bath filling system 1 comprises a hot water supply device 10 that generates hot water, a bathtub 2 for storing hot water, a hot water supply passage 20 for guiding hot water from the hot water supply device 10 to the bathtub 2, and a bath filling control device 30 provided in the middle of the hot water supply passage 20.

[0015] The hot water supply device 10 includes a burner 12 that burns fuel gas supplied through a gas passage 11, a combustion fan 13 that sends combustion air to the burner 12, and a heat exchanger 14 that exchanges heat with the combustion exhaust generated by the combustion of the burner 12. Water is supplied to the heat exchanger 14 through a water supply passage 15. The supplied water is heated by heat exchange with the combustion exhaust in the heat exchanger 14 and then flows out as hot water into a hot water supply passage 20. The water supply passage 15 connected to the upstream side of the heat exchanger 14 is provided with a stop valve 16 for stopping the supply of water to the hot water supply device 10 and a first drain valve 17 that is opened when draining the hot water supply device 10 downstream of the stop valve 16. Note that the first drain valve 17 in this embodiment corresponds to the "drain valve" of the present invention.

[0016] <{ The hot water supply passage 20 connected to the downstream side of the heat exchanger 14 branches into two before the hot water filling control device 30. One branch is connected to the bathtub 2 (hot water filling control device 30), and the other branch is connected to the faucet 21. A second drain valve 22 is provided in the middle of the faucet 21 side. The hot water filling control device 30 is connected to a water supply pressure passage 18 that branches from downstream of the first drain valve 17 in the water supply passage 15. Further, the hot water filling control device 30 is electrically connected to a controller 40 that controls the hot water filling system 1.

[0017] FIG. 2 is an explanatory diagram conceptually showing the configuration of the hot water filling control device 30 of this embodiment. As shown in the figure, the hot water filling control device 30 of this embodiment includes a hot water filling solenoid valve 31, a flow sensor 32, a filter 33, and two check valves (an upstream check valve 34 and a downstream check valve 35) on the hot water supply passage 20.

[0018] The hot water filling solenoid valve 31 can open and close the hot water supply passage 20, and its opening and closing operation is controlled by the controller 40. A well-known pilot-operated solenoid valve is used for the hot water filling solenoid valve 31 in this embodiment, but a direct-acting solenoid valve may also be used. Pilot-operated solenoid valves that utilize differential pressure generally open and close with a smaller force compared to direct-acting solenoid valves. Therefore, it is possible to reduce the size of the solenoid and suppress power consumption. Note that the hot water filling solenoid valve 31 in this embodiment corresponds to the "solenoid valve" of the present invention.

[0019] The flow rate sensor 32 is provided on the upstream side (hot water supply device 10 side) of the hot water expansion solenoid valve 31, and measures the flow rate of the hot water passing through the hot water supply passage 20. The flow rate sensor 32 of the present embodiment incorporates an impeller that rotates by the flow of the hot water in the hot water supply passage 20, measures the flow rate of the hot water based on the rotation speed of the impeller, and outputs it to the controller 40. Also, a fine filter 33 is provided on the upstream side of the flow rate sensor 32 to remove foreign matter mixed in the hot water from the hot water supply device 10. Therefore, it is possible to prevent a situation where the flow rate sensor 32 and the hot water expansion solenoid valve 31 do not operate properly due to foreign matter.

[0020] The upstream check valve 34 and the downstream check valve 35 are provided in series on the downstream side (bathtub 2 side) of the hot water expansion solenoid valve 31. The upstream check valve 34 located on the hot water expansion solenoid valve 31 side among the two check valves includes a valve body 34a that can move to open and close the hot water supply passage 20, and a closing spring 34b that biases the valve body 34a in the closing direction to close the hot water supply passage 20. When the pressure of the hot water supplied from the hot water supply device 10 rises due to the opening of the hot water expansion solenoid valve 31 and exceeds a predetermined opening pressure, the valve body 34a moves in the opening direction against the biasing force of the closing spring 34b, and the upstream check valve 34 is in an open state. Also, the downstream check valve 35 on the bathtub 2 side among the two check valves is basically configured in the same manner as the upstream check valve 34 and is biased in the closing direction, and when the pressure of the hot water supplied from the hot water supply device 10 exceeds a predetermined opening pressure due to the opening of the upstream check valve 34, it is in an open state. Thus, when the upstream check valve 34 and the downstream check valve 35 are in an open state and the hot water is allowed to pass through, the bathtub 2 is filled with hot water.

[0021] On the other hand, when the pressure of the hot water supplied from the hot water supply device 10 decreases due to reasons such as water cutoff during hot water filling, the valve body 34a is pushed back in the closing direction by the biasing force of the closing spring 34b, and the upstream check valve 34 is in a closed state. Also, the downstream check valve 35 is similarly in a closed state, thereby preventing the backflow of the hot water from the bathtub 2 side to the hot water supply device 10 side. By installing the two check valves (upstream check valve 34 and downstream check valve 35) in series in this way, it is possible to more reliably prevent the backflow of the hot water than in the case of one check valve.

[0022] Furthermore, an atmospheric release passage 36 is provided, branching off from the hot water supply passage 20 between the upstream check valve 34 and the downstream check valve 35, and an atmospheric release valve 37 is installed to open and close this atmospheric release passage 36. Details of the atmospheric release valve 37 will be described later using a separate diagram, but it is biased in the opening direction and is closed against the biasing force by receiving water pressure through the water pressure passage 18. When the water pressure drops due to a water outage or the like, the atmospheric release valve 37 opens and the hot water between the upstream check valve 34 and the downstream check valve 35 is discharged, so even if the valves are not completely closed due to a malfunction of the upstream check valve 34 or the downstream check valve 35, backflow of hot water from the bathtub 2 to the hot water supply device 10 can be prevented.

[0023] Furthermore, a communication passage 38 is connected to the atmospheric release valve 37, which connects it to the flow sensor 32 and filter 33 of the hot water supply passage 20. An air inlet valve 39 is installed to open and close this communication passage 38. Details of the air inlet valve 39 will be described later using a separate diagram, but it is biased in the opening direction and is closed against the biasing force by receiving water pressure from the atmospheric release valve 37 side. Then, as the water pressure decreases, the atmospheric release valve 37 opens, and the air inlet valve 39 also opens. The roles of the communication passage 38 and the air inlet valve 39 will be explained in detail later.

[0024] Figure 3 is a cross-sectional view showing the detailed structure of the atmospheric release valve 37 in this embodiment. First, Figure 3(a) shows the atmospheric release valve 37 in a closed state. As shown in the figure, the atmospheric release valve 37 has a structure in which a diaphragm 50 divides it into a primary chamber 51 and a secondary chamber 52. A water supply pressure passage 18, which branches off from the water supply passage 15, is connected to the primary chamber 51, and water is guided through the water supply pressure passage 18. In addition, the aforementioned communication passage 38 is connected to the primary chamber 51, and the pressure of the water acts on the air inlet valve 39 via the primary chamber 51.

[0025] On the other hand, the secondary chamber 52 includes a valve seat 54 with a valve hole 53 that communicates with the atmospheric opening passage 36, a valve body 55 supported by a diaphragm 50, and an opening spring 56 that biases the valve body 55 and the diaphragm 50 toward the primary chamber 51. The secondary chamber 52 is also connected to an exhaust passage 57 that is open to the atmosphere.

[0026] If tap water is supplied to the hot water supply device 10, the pressure of the tap water supplied to the primary chamber 51 via the tap water pressure passage 18 pushes the diaphragm 50 towards the secondary chamber 52, and the valve body 55 is pressed against the valve seat 54 against the biasing force of the valve opening spring 56, thereby blocking the valve hole 53, and the atmospheric release valve 37 is in a closed state.

[0027] Furthermore, when the bathtub 2 is filled with hot water, the solenoid valve 31 opens, allowing hot water to flow from the upstream check valve 34 and the downstream check valve 35 through the atmospheric release passage 36 to the atmospheric release valve 37. However, generally, the pressure of the tap water supplied through the tap water pressure passage 18 is higher than the pressure of the hot water supplied through the atmospheric release passage 36 via the hot water supply device 10, so the atmospheric release valve 37 remains closed.

[0028] Then, if a water outage occurs and the pressure of the tap water supplied to the primary chamber 51 through the tap water pressure passage 18 decreases, as shown in Figure 3(b), the biasing force of the valve opening spring 56 pushes the valve body 55 and diaphragm 50 back towards the primary chamber 51, causing the valve body 55 to separate from the valve seat 54, and the atmospheric release valve 37 opens. As a result, the hot water between the upstream check valve 34 and the downstream check valve 35 can pass through the atmospheric release passage 36 to the valve hole 53 and is discharged from the discharge passage 57. In addition, as the hot water is discharged, air is drawn in instead, and the space between the upstream check valve 34 and the downstream check valve 35 is replaced with air.

[0029] In this way, when the water supply is cut off, the atmospheric release valve 37 opens, preventing backflow of hot water from the bathtub 2 to the hot water supply device 10 even if the upstream check valve 34 and downstream check valve 35 are not completely closed. Furthermore, when the hot water supply device 10 is drained, the atmospheric release valve 37 also opens when the shut-off valve 16 of the water supply passage 15 is closed and the supply of tap water is stopped, allowing the hot water between the upstream check valve 34 and the downstream check valve 35 to be discharged, thus making it useful for draining the hot water filling control device 30. In addition, when the first drain valve 17 is opened following the closing of the shut-off valve 16, as the water in the water supply passage 15 and the tap water pressure passage 18 is discharged, air flowing in from the first drain valve 17 is introduced into the primary chamber 51 through the tap water pressure passage 18.

[0030] Figure 4 is an explanatory diagram showing the detailed structure of the air inlet valve 39 in this embodiment. As mentioned above, the communication passage 38 in which the air inlet valve 39 is installed has one end connected between the flow sensor 32 and the filter 33 of the hot water supply passage 20, and the other end connected to the primary chamber 51 of the atmospheric release valve 37. First, Figure 4(a) shows a cross-sectional view of the air inlet valve 39 in a closed state. As shown in the figure, the air inlet valve 39 has a valve seat 62 with a valve hole 61 that communicates with the hot water supply passage 20 at one end (right side in the figure) of the cylindrical valve chamber 60, and an inlet hole 63 that communicates with the primary chamber 51 of the atmospheric release valve 37 opens at the other end (left side in the figure) of the valve chamber 60.

[0031] Furthermore, the valve chamber 60 houses a valve body 64, and an annular sealing material 65 made of an elastic material such as rubber is attached to the end of the valve body 64 on the valve seat 62 side, and a biasing spring 66 is provided that biases the valve body 64 in a direction away from the valve seat 62. Then, the pressure of the tap water supplied through the primary chamber 51 of the atmospheric release valve 37 acts on the valve body 64 from the inlet hole 63 side, and the valve body 64 (sealing material 65) is pressed against the valve seat 62 against the biasing force of the biasing spring 66, thereby blocking the valve hole 61, and the air inlet valve 39 is in a closed state.

[0032] Although hot water supplied from the hot water supply device 10 is guided to the air inlet valve 39 through the communication passage 38 from between the flow sensor 32 and the filter 33 of the hot water supply passage 20, the pressure of the tap water supplied from the primary chamber 51 side of the atmospheric release valve 37 via the tap water pressure passage 18 is generally higher than the pressure of the hot water supplied from the hot water supply passage 20 side via the hot water supply device 10, so the air inlet valve 39 remains closed.

[0033] Figure 4(b) shows an enlarged perspective view of the valve body 64 of this embodiment. As shown, the valve body 64 has a circular large-diameter portion 64b that slides along the inner circumferential surface of the valve chamber 60, located approximately in the center of the valve stem 64a which is positioned in the passage direction of the communication passage 38. In addition, the aforementioned sealing material 65 is attached to the end of the valve stem 64a on the valve seat 62 side, and a circular flange portion 64c smaller in diameter than the large-diameter portion 64b is provided at the end of the valve stem 64a on the inlet hole 63 side. Furthermore, a flow passage 64d is formed inside the valve body 64, one end of the flow passage 64d opens to the end face of the valve stem 64a on the inlet hole 63 side, and the other end of the flow passage 64d branches into multiple (two in the illustrated example) and opens to the outer circumferential surface of the valve body 64 on the valve seat 62 side of the large-diameter portion 64b.

[0034] Then, when the water supply to the hot water heater 10 is stopped by closing the shut-off valve 16 of the water supply passage 15, the water pressure acting from the inlet hole 63 side via the primary chamber 51 of the atmospheric release valve 37 decreases. As a result, as shown in Figure 4(c), the biasing force of the biasing spring 66 pushes the valve body 64 back towards the inlet hole 63, and the flange portion 64c comes into contact with the area around the inlet hole 63. In this way, the valve body 64 (sealing material 65) separates from the valve seat 62, and the air inlet valve 39 becomes open.

[0035] Furthermore, when the first drain valve 17 is opened after the stopcock 16 is closed, water is discharged from the water supply passage 15 and the water pressure passage 18 (see Figure 1). As a result, air flowing in from the first drain valve 17 is guided through the water pressure passage 18 and the primary chamber 51 of the atmospheric release valve 37 to the communication passage 38. The air thus guided to the inlet hole 63 of the air inlet valve 39 passes through the flow passage 64d inside the valve body 64, even when the flange portion 64c of the valve body 64 is in contact with the area around the inlet hole 63, and proceeds towards the valve seat 62 side beyond the large diameter portion 64b. The air then flows out from the valve hole 61 through the gap between the seal material 65 and the valve seat 62 and is guided between the flow sensor 32 and the filter 33 of the hot water passage 20. In this embodiment, the air inlet valve 39 allows the large-diameter portion 64b of the valve body 64 to slide along the inner circumferential surface of the valve chamber 60, thereby suppressing the movement of the valve body 64 within the valve chamber 60 and improving the accuracy of valve closing, while ensuring the flow of air when the valve is open through the flow passage 64d formed within the valve body 64.

[0036] In this embodiment, the hot water filling control device 30, with the configuration described above, is equipped with a communication passage 38 and an air inlet valve 39, which allows for easy draining of the hot water filling control device 30 when the hot water supply device 10 is drained. This point will be explained below, but for comparison, the draining of a conventional hot water filling control device 30 that is not equipped with a communication passage 38 or an air inlet valve 39 will be explained first.

[0037] Figure 5 is an explanatory diagram showing the process of draining water from a conventional hot water filling control device 30 that does not have a communication passage 38 or an air inlet valve 39. First, Figure 5(a) shows the state before draining the water, and the hatched area in the figure indicates that it is filled with hot water. It is assumed that the hot water in the bathtub 2 has been drained before draining, and the hot water in the hot water supply passage 20 downstream of the downstream check valve 35 that communicates with the bathtub 2 has also been drained. In addition, since hot water is not filled during draining, the hot water filling solenoid valve 31 is in a closed state, and consequently the upstream check valve 34 and the downstream check valve 35 are also in a closed state. Furthermore, because the pressure of the tap water introduced through the tap water pressure passage 18 is applied to the primary chamber 51 of the atmospheric release valve 37, the atmospheric release valve 37 is in a closed state. Therefore, the hot water supply passage 20 and the atmospheric release passage 36 upstream of the downstream check valve 35 are filled with hot water.

[0038] When draining the water, the worker closes the shut-off valve 16 of the water supply passage 15 to stop the supply of tap water, and then opens the first drain valve 17 and the second drain valve 22 (see Figure 1). Then, as shown in Figure 5(b), the hot water upstream of the filter 33 of the hot water passage 20 (on the hot water supply device 10 side) is discharged from the second drain valve 22 (or the first drain valve 17). Note that it is also possible to discharge the hot water by opening the faucet 21 instead of the second drain valve 22. In addition, as the water in the tap water pressure passage 18 is discharged from the first drain valve 17, the tap water pressure is removed from the primary chamber 51 of the atmospheric release valve 37, causing the atmospheric release valve 37 to open. As a result, the hot water between the upstream check valve 34 and the downstream check valve 35 is discharged from the atmospheric release valve 37.

[0039] However, between the filter 33 and the upstream check valve 34, even if the hot water supply solenoid valve 31 is opened, the upstream check valve 34 remains closed, and air flowing in from the atmospheric release valve 37 does not pass through the upstream check valve 34 to the hot water supply solenoid valve 31 side (atmospheric pressure does not act). On the other hand, upstream of the filter 33, the hot water has drained from the hot water supply passage 20, so atmospheric pressure acts on the hot water downstream from the upstream side of the filter 33. In addition, the fine mesh of the filter 33 creates surface tension in the water, making it difficult for air to enter from the upstream side. Therefore, between the filter 33 and the upstream check valve 34, even if the hot water tries to flow out from the filter 33 side, there is no inflow of air to replace it, and the weight of the hot water is supported by the surface tension of the water in the filter 33 and the atmospheric pressure acting from the upstream side of the filter 33. As a result, the hot water between the filter 33 and the upstream check valve 34 remains trapped.

[0040] In contrast, Figure 6 is an explanatory diagram showing the process of draining water from the hot water supply control device 30 of this embodiment. First, Figure 6(a) shows the state before draining the water, and the hatched area in the figure indicates that it is filled with hot water. Similar to the conventional hot water supply control device 30 in Figure 5(a) described above, in the hot water supply control device 30 of this embodiment, the hot water supply solenoid valve 31 is closed before draining the water, and consequently the upstream check valve 34 and the downstream check valve 35 are also closed. In addition, the pressure of the tap water supplied through the tap water pressure passage 18 is applied to the primary chamber 51 of the atmospheric release valve 37, and the atmospheric release valve 37 is in a closed state. As a result, the hot water supply passage 20 and the atmospheric release passage 36 upstream of the downstream check valve 35 are filled with hot water.

[0041] Furthermore, the water pressure from the tap water acts on the air inlet valve 39 in the communication passage 38 via the primary chamber 51, causing the air inlet valve 39 to remain closed. As long as tap water is supplied, the air inlet valve 39 remains closed, preventing hot water from the hot water supply device 10 from flowing through the air inlet valve 39 in the communication passage 38 to the atmospheric release valve 37. This allows the bathtub 2 to be filled with hot water by opening the hot water filling solenoid valve 31.

[0042] Next, Figure 6(b) shows the state after the stopcock 16 of the water supply passage 15 has been closed during draining, and the first drain valve 17 and the second drain valve 22 have been opened. Similar to the conventional hot water supply control device 30 shown in Figure 5(b) above, the hot water upstream of the filter 33 of the hot water supply passage 20 (on the hot water supply device 10 side) is discharged from the second drain valve 22 (or the first drain valve 17). Also, the water in the water supply passage 15 and the water supply pressure passage 18 is discharged from the first drain valve 17, and the water supply pressure is no longer applied to the primary chamber 51 of the atmospheric release valve 37, causing the atmospheric release valve 37 to open, and the hot water between the upstream check valve 34 and the downstream check valve 35 is discharged from the atmospheric release valve 37.

[0043] Then, the water pressure no longer acts on the air inlet valve 39 in the communication passage 38 connected to the primary chamber 51 of the atmospheric release valve 37, causing the air inlet valve 39 to open. As a result, air flowing in from the first drain valve 17 along with the drainage of the water supply passage 15 and the water pressure passage 18 passes sequentially through the water pressure passage 18, the primary chamber 51 of the atmospheric release valve 37, and the communication passage 38 (air inlet valve 39) and is introduced between the flow sensor 32 and the filter 33 of the hot water supply passage 20 (atmospheric pressure acts on it). Consequently, the surface tension of the water in the filter 33 can no longer support the weight of the trapped hot water between the filter 33 and the upstream check valve 34, so the surface tension is broken and the hot water flows out from the filter 33 side and is discharged from the second drain valve 22. The hot water solenoid valve 31 should be kept open when draining the water.

[0044] As described above, in the hot water supply control device 30 of this embodiment, a communication passage 38 is connected between the flow sensor 32 and the filter 33 of the hot water supply passage 20, and this communication passage 38 is connected to the primary chamber 51 of the atmospheric release valve 37. An air inlet valve 39 is provided in this communication passage 38. If tap water is supplied to the hot water supply device 10, the air inlet valve 39 will be in a closed state, so hot water from the hot water supply device 10 will not flow through the communication passage 38. Furthermore, when draining the water from the hot water supply device 10, closing the shut-off valve 16 of the water supply passage 15 and opening the first drain valve 17 causes the water from the water supply passage 15 and the water pressure passage 18 to be discharged, and as air flows in from the first drain valve 17, the air inlet valve 39 opens, and replacement air is introduced between the flow sensor 32 and the filter 33 of the hot water supply passage 20 through the water pressure passage 18, the primary chamber 51, and the communication passage 38. Therefore, if the hot water filling solenoid valve 31 is kept open, it becomes possible to easily drain the water from the filter 33 of the hot water filling control device 30 to the upstream check valve 34.

[0045] Here, unlike the hot water filling control device 30 of this embodiment shown in Figure 2, a comparative example hot water filling control device 30 is briefly described, in which a communication passage 70 connecting to an atmospheric vent passage 36 is connected between the flow sensor 32 and the filter 33 of the hot water supply passage 20, as shown in Figure 7(a), and an air inlet valve 71 is provided in this communication passage 70. In the description of the comparative example, the same reference numerals are used for components similar to those in this embodiment, and their explanation is omitted.

[0046] Although the air inlet valve 71 in the comparative example is biased in the opening direction, if hot water is supplied from the hot water supply device 10, it is subjected to the pressure of the hot water from the hot water supply passage 20 side, which resists the biasing force and keeps it in a closed state. As a result, the hot water from the hot water supply device 10 does not flow through the communication passage 70 (air inlet valve 71) to the atmospheric opening passage 36, and the bathtub 2 can be filled with hot water by opening the hot water filling solenoid valve 31.

[0047] When the water supply is stopped by closing the stopcock 16 of the water supply passage 15 during draining, the water pressure in the water pressure passage 18 decreases, causing the atmospheric release valve 37 to open. As a result, the hot water between the upstream check valve 34 and the downstream check valve 35 is discharged, and air flows in through the atmospheric release valve 37. Additionally, the decrease in the water pressure from the hot water supply device 10 causes the air inlet valve 71 to open, and the air that flowed in through the atmospheric release valve 37 is introduced between the flow sensor 32 and the filter 33 of the hot water supply passage 20 through the communication passage 70. Consequently, similar to the hot water supply control device 30 of this embodiment described above, the hot water between the filter 33 and the upstream check valve 34 flows out by breaking the surface tension of the water in the filter 33, thus enabling draining.

[0048] However, as shown in Figure 7(b), if a water outage occurs while filling the bathtub, and the upstream check valve 34 and downstream check valve 35 malfunction and remain open (incompletely closed), there is a risk that the hot water flowing back from the bathtub 2 side will pass through the atmospheric release passage 36 and be discharged from the atmospheric release valve 37. In this case, the air inlet valve 71 is open, and the hot water may flow back from the atmospheric release passage 36 through the communication passage 70 between the flow sensor 32 and the filter 33 of the hot water supply passage 20, potentially flowing back to the hot water supply device 10 side.

[0049] In contrast, in the bath filling control device 30 of this embodiment, if hot water flows back from the bathtub 2 side when the upstream check valve 34 and downstream check valve 35 are not fully closed due to a water outage, etc., the hot water will be discharged from the atmospheric release valve 37 through the atmospheric release passage 36, similar to the previous example (see Figure 2). However, since the atmospheric release passage 36 and the communication passage 38 are completely independent, the hot water in the atmospheric release passage 36 will not flow back to the hot water supply device 10 side through the communication passage 38. Therefore, it is possible to facilitate the draining of the bath filling control device 30 when draining the hot water supply device 10, while avoiding the backflow of hot water that should be discharged through the atmospheric release passage 36 to the hot water supply device 10 side due to a water outage, etc.

[0050] Although the hot water filling control device 30 of this embodiment has been described above, the present invention is not limited to the above embodiment and can be implemented in various forms without departing from the spirit of the invention.

[0051] For example, in the embodiment described above, the communication passage 38 was connected between the flow sensor 32 and the filter 33 of the hot water supply passage 20. However, the connection point of the communication passage 38 to the hot water supply passage 20 is not limited to this, and it can be anywhere between the filter 33, where hot water tends to remain trapped when the water is drained, and the upstream check valve 34.

[0052] Furthermore, in the embodiment described above, the communication passage 38 was connected to the primary chamber 51 of the atmospheric release valve 37. However, the connection point of the communication passage 38 is not limited to the primary chamber 51, as long as it is possible to introduce air flowing in from the opened first drain valve 17 between the filter 33 of the hot water supply passage 20 and the upstream check valve 34. For example, the communication passage 38 may be connected to the water supply pressure passage 18, or it may be connected downstream of the stopcock 16 of the water supply passage 15. However, if the communication passage 38 is connected to the primary chamber 51 of the atmospheric release valve 37 as described above, it becomes possible to unitize the hot water supply control device 30 as an integrated unit, including the filter 33, flow sensor 32, hot water filling solenoid valve 31, the two check valves 34 and 35, and the atmospheric release valve 37 of the atmospheric release passage 36, as well as the air inlet valve 39 of the communication passage 38. [Explanation of symbols]

[0053] 1...Water filling system, 2...Bathtub, 10...Hot water supply system, 11...Gas passage, 12...Burner, 13...Combustion fan, 14…Heat exchanger, 15…Water supply passage, 16…Shut-off valve, 17...First drain valve, 18...Water supply pressure passage, 20...Hot water supply passage, 21...Faucet, 22...Second drain valve, 30...Hot water filling control device, 31...Solenoid valve for hot water supply, 32...Flow sensor, 33...Filter, 34... Upstream check valve, 34a... Valve body, 34b... Closing spring 35…Downstream check valve, 36…Atmospheric release passage, 37…Atmospheric release valve, 38...Communication passage, 39...Air inlet valve, 40...Controller, 50...Diaphragm, 51...Primary chamber, 52...Secondary chamber, 53... valve opening, 54... valve seat, 55... valve body 56... Valve opening spring, 57... Discharge passage, 60... Valve chamber, 61... Valve opening, 62... Valve seat, 63... Inlet opening, 64...valve body, 64a...valve stem, 64b...large diameter section 64c...Flange, 64d...Distribution channel, 65...Sealing material 66... ​​Biasing spring, 70... Communicating passage, 71... Air inlet valve.

Claims

1. In a hot water supply passage that guides hot water from a hot water supply device to a bathtub, and in a hot water filling control device that controls the filling of the bathtub, A solenoid valve for opening and closing the hot water supply passage, A filter is provided on the hot water supply side of the solenoid valve to remove foreign matter from the hot water supply device, Two check valves are provided in series on the bathtub side of the solenoid valve, biased in the closing direction to close the hot water supply passage, and open when the pressure of the hot water supplied from the hot water supply device exceeds a predetermined opening pressure. An atmospheric release valve is provided that can be opened and closed, which is located between the two check valves of the hot water supply passage. The atmospheric release valve receives the pressure of tap water via a tap water pressure passage that branches off from the water supply passage that leads tap water to the hot water supply device, thereby closing against the biasing force of the valve opening spring. When the tap water pressure decreases, the valve opens due to the biasing force of the valve opening spring, and discharges the hot water between the two check valves. Air flowing in from the drain valve, which is opened when the water supply passage and the water pressure passage are drained, is introduced through a communication passage connected between the upstream check valve on the solenoid valve side of the two check valves and the filter. The aforementioned communication passage is provided so as to be openable and closable, and is biased in the opening direction, and the air inlet valve closes when it receives the pressure of the water supply when the drain valve is closed. A hot water filling control device characterized by comprising the following features.

2. In the hot water filling control device according to claim 1, The aforementioned atmospheric release valve has a primary chamber to which the water pressure passage is connected and a secondary chamber to which the atmospheric release passage is connected, separated by a diaphragm, and the diaphragm is biased toward the primary chamber by the valve opening spring, and when water pressure is applied to the primary chamber via the water pressure passage, the diaphragm is pushed toward the secondary chamber, thereby closing the valve. The aforementioned communication passage has one end connected between the upstream check valve and the filter of the hot water supply passage, and the other end connected to the primary chamber of the atmospheric release valve. A hot water filling control device characterized by the following features.

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