Atmospheric release valve

Abstract

To promote draining of hot water in a hot water supply passage while an atmosphere open valve is opened together with draining a hot water supply device.SOLUTION: As a structure of an atmosphere open valve 37 connected to a hot water supply passage for introducing hot water to a bathtub from a hot water supply device, an opening chamber 52 formed by upwardly extending a connection passage 53 to the hot water supply passage, and a back pressure chamber 51, in which pressure of water supply to the hot water supply device is introduced via a pressure detection passage 18, are partitioned at upper and lower sections by a diaphragm 50. A valve body 55 housed in the opening chamber is supported by the diaphragm movably upward and downward, and energized toward a back pressure chamber side by an energization member 56. Also, one end of a discharge passage 58 is opened on a side face of the opening chamber. The valve body moves upward by the pressure of the supply water introduced to the back pressure chamber, into a contact a valve seat 54 surrounding an opening of the connection passage on a top face of the opening chamber to close a vale. The valve body is isolated from the valve seat together with reduction of the pressure of supply water, so as to open the valve. A step D is provided on an inner periphery of the connection passage by enlarging a diameter of an end on the opening chamber side.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to an atmospheric release valve that is connected to a hot water supply passage for guiding hot water from a hot water supply device to a bathtub, closes by receiving the pressure of the water supply to the hot water supply device, and opens when the pressure of the water supply decreases to discharge the hot water in the hot water supply passage.

Background Art

[0002] It has been proposed to prevent the backflow of hot water from the bathtub, such as during water cut-off, by connecting an atmospheric release valve to the hot water supply passage for guiding hot water from the hot water supply device to the bathtub (for example, Patent Document 1). The atmospheric release valve generally has a structure partitioned by a flexible diaphragm into an upper release chamber and a lower back pressure chamber. A connection passage extending upward from the release chamber is connected to the hot water supply passage, and the pressure of the water supply to the hot water supply device is introduced into the back pressure chamber via a pressure detection passage. Further, the valve body housed in the release chamber is supported by the diaphragm so as to be able to move up and down, and is biased toward the back pressure chamber side by a biasing member. Furthermore, one end of a discharge passage is open on the side surface of the release chamber, and the other end of the discharge passage is open to the atmosphere.

[0003] In such an atmospheric release valve, if the hot water supply device is being normally supplied with water, the diaphragm is pushed into the release chamber side by the pressure of the water supply introduced into the back pressure chamber, and the valve body abuts against the valve seat surrounding the opening of the connection passage on the upper surface of the release chamber against the biasing force of the biasing member to close the valve. On the other hand, when the pressure of the water supply decreases due to water cut-off or the like, the valve body separates from the valve seat by the biasing force of the biasing member and the atmospheric release valve opens, and the hot water in the hot water supply passage is discharged, thereby preventing the hot water from flowing back from the bathtub to the hot water supply device. Also, not only during water cut-off, but when the hot water supply device is drained, the atmospheric release valve opens, the hot water in the hot water supply passage is discharged and replaced with the inflowing air, making it possible to prevent damage due to freezing expansion in winter.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2009-270698 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, conventional atmospheric vent valves had a problem in that even when opened to drain the water from the hot water supply system, the hot water in the hot water passage sometimes did not discharge. This is because, as atmospheric vent valves become smaller, if the valve body separates from the valve seat and opens, a sufficient opening cannot be secured, and the discharge of hot water is hindered by surface tension. In particular, since surface tension increases as the temperature decreases, this problem of hot water not being discharged is more likely to occur in winter.

[0006] This invention addresses the aforementioned problems in the prior art and aims to provide a technology that can facilitate the discharge of hot water from the hot water supply passage when the atmospheric release valve is open in conjunction with the draining of water from the hot water supply system. [Means for solving the problem]

[0007] To solve the above-mentioned problems, the atmospheric release valve of the present invention employs the following configuration: An atmospheric release valve connected to a hot water supply passage that guides hot water from a hot water supply device to a bathtub, which closes when it receives the pressure of the water supply to the hot water supply device, and opens when the water supply pressure decreases to discharge the hot water from the hot water supply passage, An open room having an opening passage that extends upwards, connected to the aforementioned hot water supply passage, A back pressure chamber is provided below the open chamber, separated by a diaphragm, through which the water supply pressure is introduced via a pressure sensing passage. A valve body housed in the aforementioned open chamber and supported by the diaphragm so as to be able to move up and down, A biasing member that biases the valve body toward the back pressure chamber side, An exhaust passage is provided on the side of the aforementioned open chamber, with one end open and the other end open to the atmosphere. Equipped with, When the diaphragm is pushed towards the open chamber by the pressure of the water supply introduced into the back pressure chamber, the valve body contacts the valve seat surrounding the opening of the connecting passage on the upper surface of the open chamber against the biasing force of the biasing member, thereby closing the valve. As the pressure of the water supply decreases, the valve body separates from the valve seat due to the biasing force of the biasing member, thereby opening the valve. A step is provided on the inner circumferential surface of the connecting passage by widening the diameter at the end on the open chamber side. It is characterized by the following:

[0008] In the atmospheric release valve of the present invention, by widening the diameter of the end on the open chamber side of the connecting passage and creating a step on the inner circumferential surface, it is possible to secure a gap between the valve body and the valve seat when the valve body contact portion is separated from the valve seat in the open state, and to eliminate a narrowed portion that is narrower than the gap between the valve seat and the valve body contact portion. As a result, when the atmospheric release valve is open, surface tension is less likely to act on the hot water at the end on the open chamber side of the connecting passage, making it possible to promote the discharge of hot water from the hot water supply passage.

[0009] In the atmospheric release valve of the present invention described above, the following may also be applied. First, the valve body has a plurality of guide pieces erected upwards on the inside of the annular contact portion that contacts the valve seat, and in the open valve state where the contact portion of the valve body is separated from the valve seat, the tips of the plurality of guide pieces are inserted inside the narrow diameter portion that is on the hot water passage side of the step in the connecting passage. The plurality of guide pieces then slide along the inner circumferential surface of the narrow diameter portion to guide the vertical movement of the valve body.

[0010] In an atmospheric release valve with this configuration, instead of widening the inner diameter of the connecting passage as a whole, a step is created. This allows the narrower diameter section on the hot water passage side (upper side) of the step to retain its function of guiding the vertical movement of the valve body as a sliding surface for the guide piece, while the wider diameter section on the opening chamber side (lower side) of the step ensures a gap with the valve body when the valve is open, thereby promoting the discharge of hot and cold water.

[0011] Furthermore, the atmospheric release valve of the present invention described above may also be configured as follows. First, the valve body has a convex portion that is located inside the annular contact portion that contacts the valve seat and protrudes above the contact portion, and the outer diameter of the convex portion is larger than the inner diameter of the narrow portion on the hot water passage side of the step in the connecting passage. When the valve body is in a closed state with the contact portion in contact with the valve seat, the convex portion is housed in the inner space of the wide portion on the open chamber side of the step in the connecting passage.

[0012] In an atmospheric release valve with this configuration, as the valve body separates from the valve seat and the valve opens, the protrusion recedes from the inner space of the large-diameter section. As a result, the volume of wastewater removed by the protrusion in the inner space of the large-diameter section decreases, causing a drop in pressure. Consequently, air is drawn into the inner space of the large-diameter section from the discharge passage side, and hot water is drawn in from the hot water supply passage side. The resulting turbulence at the interface makes it difficult for surface tension to act on the hot water, thus promoting the discharge of hot water.

[0013] In the atmospheric release valve of the present invention, the following may also be used. First, the valve body comprises a contact base having an annular contact portion that abuts against the valve seat and an adhesive plate that is attached to the diaphragm, connected by a support column smaller in diameter than the contact base and the adhesive plate, with an annular space extending around the entire circumference of the support column between the contact base and the adhesive plate. When the valve is open, with the contact portion of the valve body separated from the valve seat, one end of the discharge passage opening to the side of the open chamber faces the annular space of the valve body.

[0014] In an atmospheric release valve with this configuration, the air flowing in through the discharge passage circulates around the annular space, allowing replacement air to be introduced into the connecting passage not only on the side where the discharge passage opens, but also around the entire circumference of the valve body. Furthermore, the hot water in the connecting passage can also flow out into the discharge passage via the annular space around the entire circumference of the valve body, not just on the side where the discharge passage opens, thus promoting the discharge of hot water from the hot water supply passage. [Brief explanation of the drawing]

[0015] [Figure 1]It is an explanatory diagram illustrating the overall configuration of the hot water supply system 1 in which the atmosphere release valve 37 of the present embodiment is used. [Figure 2] It is an explanatory diagram conceptually showing the configuration of the hot water supply control device 30 in which the atmosphere release valve 37 of the present embodiment is incorporated. [Figure 3] It is an explanatory diagram exemplifying a case where hot water in the hot water supply passage 20 remains even when the atmosphere release valve 37 opens as the hot water supply device 10 is drained. [Figure 4] It is a longitudinal sectional view showing the structure of the atmosphere release valve 37 of the present embodiment. [Figure 5] It is a perspective view showing an enlarged view of the valve body 55 of the present embodiment. [Figure 6] It is a longitudinal sectional view showing the state where the atmosphere release valve 37 of the present embodiment is open.

Mode for Carrying Out the Invention

[0016] FIG. 1 is an explanatory diagram illustrating the overall configuration of the hot water supply system 1 in which the atmosphere release valve 37 of the present embodiment is used. As shown in the figure, the hot water supply system 1 includes a hot water supply device 10 that generates hot water, a bathtub 2 that stores 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 hot water supply control device 30 provided in the middle of the hot water supply passage 20. The atmosphere release valve 37 of the present embodiment is incorporated in the hot water supply control device 30.

[0017] The hot water supply device 10 includes a burner 12 that burns the fuel gas supplied through the gas passage 11, a combustion fan 13 that sends combustion air to the burner 12, and a heat exchanger 14 for exchanging heat with the combustion exhaust generated by the combustion in the burner 12. The heat exchanger 14 is supplied with raw water through the water supply passage 15. The supplied raw water is heated by heat exchange with the combustion exhaust in the heat exchanger 14 and then flows out as hot water into the hot water supply passage 20. Further, the combustion exhaust that has passed through the heat exchanger 14 is discharged outside the device from the upper part of the hot water supply device 10.

[0018] In the water supply passage 15 connected to the upstream side of the heat exchanger 14, there are a stop valve 16 for stopping the supply of make-up water to the water heater 10, and a first drain valve 17 that is opened when draining the water heater 10 downstream of the stop valve 16. Further, a pressure detection passage 18 branched from downstream of the first drain valve 17 of the water supply passage 15 is provided, and this pressure detection passage 18 is connected to the hot water filling control device 30.

[0019] 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 is connected to the bathtub 2 via the hot water filling control device 30, and the other is connected to the faucet 21. A second drain valve 22 for draining water is provided in the middle of the faucet 21 side. Further, the hot water filling control device 30 is electrically connected to a controller 40 that controls the entire hot water filling system 1.

[0020] FIG. 2 is an explanatory diagram conceptually showing the configuration of the hot water filling control device 30 in which the atmosphere release valve 37 of the present embodiment is incorporated. As shown in the figure, the hot water filling control device 30 first includes a hot water filling solenoid valve 31, a flow sensor 32, a filter 33, and two check valves (a first check valve 34 and a second check valve 35) on the hot water supply passage 20.

[0021] 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. The hot water filling starts when the hot water filling solenoid valve 31 is opened, and the hot water filling stops when the hot water filling solenoid valve 31 is closed. A well-known pilot-operated solenoid valve is used for the hot water filling solenoid valve 31 of the present embodiment, but a direct-acting solenoid valve may also be used. Since a pilot-operated solenoid valve that utilizes differential pressure generally opens and closes with a smaller force compared to a direct-acting solenoid valve, it is possible to reduce the size of the actuator and suppress power consumption.

[0022] The flow sensor 32 is located upstream of the hot water supply solenoid valve 31 (on the hot water supply device 10 side) and measures the flow rate of hot water passing through the hot water supply passage 20. The flow sensor 32 in this embodiment has a built-in impeller that rotates due to the flow of hot water in the hot water supply passage 20, and measures the flow rate of hot water based on the rotation speed of the impeller and outputs it to the controller 40. Furthermore, a filter 33 is provided upstream of the flow sensor 32, and by removing foreign matter mixed in with the hot water from the hot water supply device 10 with the filter 33, it prevents the flow sensor 32 and the hot water supply solenoid valve 31 from malfunctioning due to foreign matter.

[0023] The first check valve 34 and the second check valve 35 are installed in series downstream of the hot water filling solenoid valve 31 (on the bathtub 2 side). As shown in the figure, the first check valve 34, located on the hot water filling solenoid valve 31 side, includes a valve body 34a that moves 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 hot water filling solenoid valve 31 opens and the pressure of the hot water supplied from the hot water supply device 10 rises and exceeds a predetermined opening pressure, the valve body 34a moves in the opening direction against the biasing force of the closing spring 34b, so the first check valve 34 becomes open. The second check valve 35, located on the bathtub 2 side, is also biased in the closing direction with basically the same configuration as the first check valve 34, and becomes open 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 first check valve 34. In this way, the first check valve 34 and the second check valve 35 open, allowing hot water to pass through, and thus the bathtub 2 is filled with hot water.

[0024] On the other hand, if the pressure of the hot water supplied from the hot water supply device 10 decreases due to a water outage or other reason while the bathtub is being filled, the biasing force of the valve closing spring 34b pushes the valve body 34a back in the closing direction, and the first check valve 34 closes. Similarly, the second check valve 35 also closes, preventing the backflow of hot water from the bathtub 2 to the hot water supply device 10. By installing the two check valves 34 and 35 in series in this way, the backflow of hot water can be prevented more reliably than when there is only one check valve.

[0025] Furthermore, an atmospheric release valve 37 is connected to the hot water supply passage 20 between the first check valve 34 and the second check valve 35. Details of the atmospheric release valve 37 will be described later using a separate diagram, but it is biased in the opening direction, and if tap water is supplied normally to the hot water supply device 10, it is closed against the biasing force by receiving the pressure of the tap water via the pressure sensing passage 18. On the other hand, if a water outage occurs and the pressure of the tap water drops, the atmospheric release valve 37 opens due to the biasing force, and the hot water in the hot water supply passage 20 between the first check valve 34 and the second check valve 35 is discharged. Therefore, even if the valve closing is incomplete due to a malfunction of the first check valve 34 or the second check valve 35, backflow of hot water from the bathtub 2 side to the hot water supply device 10 side can be prevented.

[0026] Furthermore, the atmospheric release valve 37 opens not only in the event of a water outage, but also when the water in the hot water supply system 10 is drained to prevent damage due to freezing and expansion in winter. However, with conventional atmospheric release valves 37, even when the valve opens in conjunction with the draining of the hot water supply system 10, the hot water in the hot water supply passage 20 between the first check valve 34 and the second check valve 35 may not be easily discharged and may remain. This point will be explained in detail below.

[0027] Figure 3 is an explanatory diagram illustrating a case in which hot water remains in the hot water supply passage 20 even after the atmospheric release valve 37 opens due to the draining of the hot water supply device 10. First, Figure 3(a) shows the state inside the hot water filling control device 30 before the draining of the hot water supply device 10, and the hatched parts in the figure represent the presence of hot water. It is assumed that before the draining of the hot water supply device 10, the hot water in the bathtub 2 is drained, and the hot water in the hot water supply passage 20 downstream of the second check valve 35 is discharged. Also, since hot water is not filled during the draining, the hot water filling solenoid valve 31 is in a closed state, and consequently the first check valve 34 and the second check valve 35 are also in a closed state. In addition, since the water pressure is applied to the pressure sensing passage 18, the atmospheric release valve 37 is in a closed state.

[0028] When draining the hot water supply system 10, 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 3(b), the hot water upstream of the hot water supply solenoid valve 31 in the hot water supply passage 20 (on the hot water supply system 10 side) is discharged from the second drain valve 22 (or the first drain valve 17). In addition, since the hot water supply solenoid valve 31, which employs a pilot-operated solenoid valve, opens as the hot water on the upstream side is discharged (the pressure of the hot water decreases), the hot water in the hot water supply passage 20 between the hot water supply solenoid valve 31 and the first check valve 34 is also discharged from the second drain valve 22. Note that even when the hot water supply solenoid valve 31 opens, the first check valve 34 and the second check valve 35 remain closed.

[0029] Furthermore, as mentioned above, the pressure-sensing passage 18 branches off downstream from the first drain valve 17 of the water supply passage 15, and when the first drain valve 17 is opened, the tap water in the pressure-sensing passage 18 is discharged from the first drain valve 17. As a result, there is no longer any tap water pressure in the pressure-sensing passage 18, and the atmospheric release valve 37 opens. However, even though the atmospheric release valve 37 opens due to the draining of the hot water supply device 10, there are cases where the hot water in the hot water supply passage 20 between the first check valve 34 and the second check valve 35 is not discharged and remains. This is thought to be due to the following reasons.

[0030] Firstly, with the miniaturization of the atmospheric release valve 37, even when the atmospheric release valve 37 is open, if the opening degree is not sufficiently secured, surface tension is easily exerted on the hot water in the constricted portion, and this surface tension supports the hot water, hindering its discharge. In particular, since this surface tension increases as the temperature decreases, the hot water may not be discharged easily in winter and may remain, potentially leading to damage due to freezing expansion.

[0031] Furthermore, although the discharge of hot water from the hot water supply passage 20 requires replacement by introducing air, both the first check valve 34 and the second check valve 35 remain closed, and the hot water supply passage 20 is a dead end between the first check valve 34 and the second check valve 35. Therefore, the only way to replace the water is to introduce air through the open atmospheric release valve 37. However, if the introduction of air from this atmospheric release valve 37 is obstructed, the hot water will remain without being discharged. Therefore, in this embodiment, the atmospheric release valve 37 is configured as follows to promote the discharge of hot water from the hot water supply passage 20 when it is opened in conjunction with the draining of the hot water supply device 10.

[0032] Figure 4 is a longitudinal cross-sectional view showing the structure of the atmospheric release valve 37 in this embodiment. The figure 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 flexible diaphragm 50 divides it into a lower back pressure chamber 51 and an upper open chamber 52. A pressure sensing passage 18, which branches off from the water supply passage 15, is connected to the back pressure chamber 51, and tap water is guided through the pressure sensing passage 18.

[0033] Above the open chamber 52, a connecting passage 53 is provided, which is connected to the hot water supply passage 20 between the first check valve 34 and the second check valve 35. A valve seat 54 is provided surrounding the opening of the connecting passage 53 on the upper surface of the open chamber 52. A valve body 55, supported by a diaphragm 50 so as to be able to move up and down, is housed inside the open chamber 52. Furthermore, one end of a discharge passage 58 is open on the side of the open chamber 52, and the other end of the discharge passage 58 is open to the atmosphere.

[0034] Figure 5 is an enlarged perspective view of the valve body 55 of this embodiment. In the figure, the valve body 55 is shown cut in a substantially vertical plane containing the central axis of the valve body 55 to reveal its cross-sectional shape. As shown in the figure, the valve body 55 of this embodiment has a structure in which a packing base 61 on which an annular packing 60 that abuts against the valve seat 54 is embedded in the upper surface, and an adhesive plate 62 that is attached to the diaphragm 50 are connected via a support column 63 that is smaller in diameter than the packing base 61 and the adhesive plate 62, and an annular space 64 is provided around the entire circumference of the support column 63 between the packing base 61 and the adhesive plate 62. In the valve body 55 of this embodiment, the annular space 64 is made wide by making the area ratio of the cross-sectional area of ​​the packing base 61 to the cross-sectional area of ​​the support column 63 cut in a plane perpendicular to the central axis to 5 times or more. The role of the annular space 64 will be explained in detail later. The packing base 61 of this embodiment corresponds to the "contact base" of the present invention.

[0035] Furthermore, an annular packing retainer 66 is installed above the packing base 61 to prevent the packing 60 from coming off. The central mating hole of the packing retainer 66 is mated with a protruding portion 65 that protrudes upward from the center of the upper surface of the packing base 61 and fixed in place. The outer diameter of the packing retainer 66 is smaller than the outer diameter of the packing 60 and larger than the inner diameter of the packing 60, so that the packing retainer 66 is located inside the contact portion of the packing 60 with the valve seat 54. In addition, the outer edge of the packing retainer 66 is sloped downward from the inside to the outside. Furthermore, multiple (three in this embodiment) guide pieces 67 are erected upward at equal intervals along the outer edge of the packing retainer 66.

[0036] As shown in Figure 4, the valve body 55 is housed in the open chamber 52 and is biased from above toward the back pressure chamber 51 by a biasing spring 56. The biasing spring 56 is supported at its upper end by a spring receiver 57 in the connecting passage 53 and at its lower end by contact with a packing retainer 66. The spring receiver 57 is a hollow cylindrical member, and its outer surface is connected to the inner surface of the connecting passage 53 by multiple (three in this embodiment) spokes, allowing hot and cold water to flow through. In addition, multiple guide pieces 67 are positioned inside the valve seat 54 (the contact portion of the packing 60) and inserted into the inside of the connecting passage 53. Each of the guide pieces 67 slides along the inner surface of the connecting passage 53, guiding the vertical movement of the valve body 55.

[0037] In Figure 4, the diaphragm 50 is pushed towards the open chamber 52 by the pressure of the water supplied to the back pressure chamber 51 via the pressure sensing passage 18. The packing 60 of the valve body 55 then contacts the valve seat 54 against the biasing force of the biasing spring 56, blocking the opening of the connecting passage 53, thus closing the atmospheric release valve 37. The biasing spring 56 in this embodiment corresponds to the "biasing member" of the present invention.

[0038] On the other hand, Figure 6 is a longitudinal cross-sectional view showing the state in which the atmospheric release valve 37 of this embodiment is open. When the water supply device 10 is drained, and the pressure of the tap water is no longer applied to the back pressure chamber 51 via the pressure sensing passage 18, as shown in Figure 6(a), the biasing force of the biasing spring 56 pushes the valve body 55 and diaphragm 50 back towards the back pressure chamber 51, and the packing 60 of the valve body 55 separates from the valve seat 54, opening the opening of the connecting passage 53, so that the atmospheric release valve 37 is open. Furthermore, on the inner circumferential surface of the connecting passage 53 of this embodiment, as shown in an enlarged view in Figure 6(b), a step D is provided between the lower larger diameter portion 53a and the upper smaller diameter portion 53b by widening the diameter of the end on the opening chamber 52 side.

[0039] As shown by the dashed line in Figure 6(b), if a step D (large diameter portion 53a) is not provided on the inner circumferential surface of the connecting passage 53, it becomes difficult to secure the gap with the valve body 55 (packing retainer 66), and a narrowed portion that is narrower than the gap between the valve seat 54 and the packing 60 is likely to form. As a result, surface tension acts on the hot and cold water in the narrowed portion, hindering the discharge of the hot and cold water. In contrast, in the atmospheric release valve 37 of this embodiment, by providing a step D (large diameter portion 53a) at the end of the inner circumferential surface of the connecting passage 53 on the open chamber 52 side, it is possible to secure the gap with the valve body 55 (packing retainer 66) and eliminate the narrowed portion. As a result, when the atmospheric release valve 37 is open, surface tension is less likely to act on the hot and cold water at the end of the connecting passage 53 on the open chamber 52 side, promoting the discharge of the hot and cold water. In addition, by widening the inner diameter at the end of the connecting passage 53 on the open chamber 52 side, even if the hot water is supported by surface tension within the connecting passage 53 (narrow diameter section 53b), the interface (surface) will widen as the hot water moves down from the narrow diameter section 53b to the wide diameter section 53a due to its weight. This makes it easier to break the surface tension compared to the case where the inner diameter of the connecting passage 53 does not change (remains the same diameter).

[0040] Furthermore, as shown in Figure 6(a), when the atmospheric release valve 37 is open, the tips of the multiple guide pieces 67 in the valve body 55 of this embodiment are inserted inside the narrow-diameter portion 53b, which is on the upper side (hot water supply passage 20 side) of the step D in the connecting passage 53, and each of the guide pieces 67 slides along the inner circumferential surface of the narrow-diameter portion 53b. In other words, by providing the step D rather than widening the inner diameter of the connecting passage 53 as a whole, the upper narrow-diameter portion 53b retains the function of guiding the vertical movement of the valve body 55 as the sliding surface of the guide pieces 67, while the lower wide-diameter portion 53a (opening chamber 52 side) secures the gap with the valve body 55 as described above, thereby promoting the discharge of hot water when the valve is open.

[0041] In addition, the packing retainer 66 of the valve body 55 in this embodiment is located inside the contact portion of the packing 60 with the valve seat 54, and the outer diameter of the packing retainer 66 is larger than the inner diameter of the narrow portion 53b of the connecting passage 53. Moreover, the upper surface of the packing retainer 66 protrudes above the contact portion of the packing 60, and when the atmospheric release valve 37 is closed, the packing retainer 66 is housed in the inner space of the wide portion 53a of the connecting passage 53 (see Figure 4). Then, as the atmospheric release valve 37 opens, the packing retainer 66 retracts from the inner space of the wide portion 53a (see Figure 6), and the volume excluded by the packing retainer 66 in the inner space of the wide portion 53a decreases, causing the pressure to drop. As a result, air is drawn into the inner space of the large-diameter portion 53a from the discharge passage 58 side, and hot water is drawn in from the hot water supply passage 20 side. Because the interface is disturbed, surface tension is less likely to act on the hot water, thus promoting the discharge of hot water. The packing retainer 66 in this embodiment corresponds to the "protrusion" of the present invention.

[0042] Furthermore, as mentioned above, the valve body 55 of this embodiment is provided with an annular space 64 between the packing base 61 and the adhesive plate 62 (see Figure 5). When the atmospheric release valve 37 is open, as shown in Figure 6(a), one end of the discharge passage 58 that opens on the side of the open chamber 52 faces the annular space 64 of the valve body 55. In this way, the air flowing in through the discharge passage 58 wraps around the annular space 64, making it possible to introduce replacement air into the connecting passage 53 not only on the side where the discharge passage 58 opens, but also around the entire circumference of the valve body 55. In addition, the hot water in the connecting passage 53 can also flow out to the discharge passage 58 via the annular space 64 around the entire circumference of the valve body 55, not just on the side where the discharge passage 58 opens, thus promoting the discharge of hot water from the hot water supply passage 20. Note that the annular space 64 of the valve body 55 does not need to face one end of the discharge passage 58 over its entire height; it is sufficient if it faces one end of the discharge passage 58 over at least a portion of its height.

[0043] Although the atmospheric release valve 37 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.

[0044] For example, in the embodiment described above, the atmospheric release valve 37 was installed such that the valve body 55 was movable in the vertical direction and the connecting passage 53 was also connected in the vertical direction (vertical orientation). However, the orientation of the atmospheric release valve 37 is not limited to vertical; the valve body 55 may be movable in the left-right direction and the connecting passage 53 may also be connected in the left-right direction (horizontal orientation). However, the problem of hot water not being discharged from the hot water supply passage 20 when the atmospheric release valve 37 is open is more likely to occur in the vertical orientation than in the horizontal orientation. Therefore, the present invention can be suitably applied when the atmospheric release valve 37 is installed in the vertical orientation. [Explanation of Symbols]

[0045] 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...Pressure testing 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...First check valve, 34a...Valve body, 34b...Closing spring 35...Second check valve, 37...Atmospheric release valve, 40...Controller 50...Diaphragm, 51...Back pressure chamber, 52...Open chamber, 53...connecting passage, 53a...large diameter section, 53b...small diameter section, 54... Valve seat, 55... Valve body, 56... Biasing spring 57...Spring support, 58...Discharge passage, 60...Packing, 61... Packing base, 62... Adhesive plate, 63... Support column, 64...Annular space, 65...Protruding part, 66...Packing retainer, 67... Guide piece, D... Step.

Claims

1. An atmospheric release valve connected to a hot water supply passage that guides hot water from a hot water supply device to a bathtub, which closes when it receives the pressure of the water supply to the hot water supply device, and opens when the water supply pressure decreases to discharge the hot water from the hot water supply passage, An open room having an opening passage that extends upwards, which is connected to the aforementioned hot water supply passage, A back pressure chamber is provided below the open chamber, separated by a diaphragm, through which the water supply pressure is introduced via a pressure sensing passage. A valve body housed in the aforementioned open chamber and supported by the diaphragm so as to be able to move up and down, A biasing member that biases the valve body toward the back pressure chamber side, An exhaust passage is provided on the side of the aforementioned open chamber, with one end open and the other end open to the atmosphere. Equipped with, When the diaphragm is pushed towards the open chamber by the pressure of the water supply introduced into the back pressure chamber, the valve body contacts the valve seat surrounding the opening of the connecting passage on the upper surface of the open chamber against the biasing force of the biasing member, thereby closing the valve. As the pressure of the water supply decreases, the valve body separates from the valve seat due to the biasing force of the biasing member, thereby opening the valve. A step is provided on the inner circumferential surface of the connecting passage by widening the diameter at the end on the open chamber side. An atmospheric release valve characterized by the following features.

2. In the atmospheric release valve according to claim 1, The valve body has a plurality of guide pieces erected upwards, located inside the annular contact portion that abuts against the valve seat, In the open valve state, where the contact portion of the valve body is separated from the valve seat, the tip ends of the plurality of guide pieces are inserted inside the narrow diameter portion of the step in the connecting passage that is on the hot water passage side. The plurality of guide pieces slide along the inner circumferential surface of the narrow diameter portion, thereby guiding the vertical movement of the valve body. An atmospheric release valve characterized by the following features.

3. In the atmospheric release valve according to claim 1, The valve body has a protrusion that is located inside the annular contact portion that contacts the valve seat, and that protrudes above the contact portion. The outer diameter of the protrusion is larger than the inner diameter of the narrow portion on the hot water supply passage side of the step in the connecting passage. In the closed valve state, where the contact portion of the valve body is in contact with the valve seat, the protrusion is housed in the inner space of the larger diameter portion on the open chamber side of the step in the connecting passage. An atmospheric release valve characterized by the following features.

4. In the atmospheric release valve according to any one of claims 1 to 3, The valve body comprises a contact base having an annular contact portion that abuts against the valve seat and an adhesive plate that is attached to the diaphragm, connected by a support column smaller in diameter than the contact base and the adhesive plate, with an annular space between the contact base and the adhesive plate extending around the entire circumference of the support column. In the open state, where the contact portion of the valve body is separated from the valve seat, one end of the discharge passage, which opens to the side of the open chamber, faces the annular space of the valve body. An atmospheric release valve characterized by the following features.

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