Automatic drainage system and thermo unit

Abstract

To provide an automatic drainage device capable of suppressing a rise in water temperature in a stagnation part of a water supply pipe.SOLUTION: An automatic drainage device (1) that is connected to a retention part piping (3e) in a water supply pipe and automatically discards water in the retention part piping, comprises: a drain pipe (11) that is connected directly or indirectly to the retention part piping; and a first thermo unit (30A) that is installed in the middle of the drain pipe and opens a flow channel as a temperature of the water in the retention part piping increases. The first thermo unit has a first pipe member that has a valve seat inside, and a first thermoelement that has a valve body engaging with the valve seat and an expandable part expanding and contracting depending on the temperature, and is assembled inside the first pipe member so that the valve body separates from the valve seat with expansion of the expandable part when the temperature of the water rises to or above a specified temperature.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an automatic drainage device that is connected to a stagnation pipe in a water supply pipe and automatically drains water from the stagnation pipe. [Background technology]

[0002] As a measure to deal with the decline in the concentration of residual chlorine in tap water, many utilities have installed waste water pipes from the end of the main water pipe or pipe network (retention pipes) to drainage systems such as drain ditches, and are constantly discharging water from the waste water pipes to the drainage system, or periodically discharging water by opening and closing drain valves installed on the waste water pipes. However, constant discharge poses problems such as an increase in non-revenue water and loss of water resources, and periodic discharge requires workers to go to the locations where the drain valves are installed to open and close them, which creates a labor burden for employees.

[0003] On the other hand, as disclosed in Patent Publication No. 2009-221762 (Patent Document 1), Patent Publication No. 2013-170376 (Patent Document 2), and Patent Publication No. 2021-130995 (Patent Document 3), a technology has been known in the past in which an automatic drainage device equipped with a drainage valve such as an electromagnetic valve and a controller that controls the opening and closing of the drainage valve using a timer or the like is installed in the middle of the drainage pipe, and water is automatically drained at any desired timing.

[0004] For example, the automatic drainage device 100 shown in Figure 14 is installed midway along a wastewater pipe 5 from the end of a main water pipe (tap water pipe) 3 to a drain ditch 4 as part of a drainage system. The automatic drainage device 100 of Patent Document 3 is equipped with a piping unit 101 that is a unit formed by pre-assembling at least the connecting pipes and solenoid valves that are to be interposed in the wastewater pipe 5. This makes it possible to make the automatic drainage device 100 smaller, so that the entire automatic drainage device 100, including the controller box 102, can be stored in the water meter box 2. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-221762 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-170376 [Patent Document 3] Patent Publication No. 2021-130995 Summary of the Invention [Problem to be solved by the invention]

[0006] There are various conditions that determine the deliciousness of water, one of which is water temperature, with colder water generally being perceived as tastier. The same can be said for tap water, and with users increasingly demanding better tasting water, efforts to combat rising water temperatures are becoming increasingly important.

[0007] In water pipes, rising water temperatures in stagnant areas are a particular issue. In recent years, the number of stagnant areas has been increasing due to a decrease in water demand caused by a declining population, the spread of water-saving devices, and lifestyle changes. In addition, abnormal weather often results in higher-than-average temperatures in the summer, raising concerns about an increase in areas where tap water temperatures are rising.

[0008] Although there are technologies such as those described in Patent Documents 1 to 3 that prevent a decrease in the concentration of residual chlorine by connecting an automatic drainage device including an electromagnetic valve to the stagnant section piping of a water pipe, there are no technologies that suppress the rise in water temperature in the stagnant section.

[0009] The present invention has been made to solve the above-mentioned problems, and its purpose is to provide an automatic drainage device that can suppress the rise in water temperature in the stagnant section of a water supply pipe during the summer.

[0010] Another object of the automatic drainage device of the present invention is to prevent the drainage pipes installed in the device from freezing in winter, and another object of the present invention is to provide a thermo unit suitable for such an automatic drainage device. [Means for solving the problem]

[0011] An automatic drainage device according to one aspect of the present invention is an automatic drainage device connected to a stagnation section piping in a water supply pipe to automatically drain the water in the stagnation section piping, and includes a drain pipe connected directly or indirectly to the stagnation section piping, and a first thermo-unit provided at a midpoint of the drain pipe and opening a flow path as the temperature of the water in the stagnation section piping rises. The first thermo-unit includes a first pipe member having a valve seat therein, a valve body that engages with the valve seat, and a first thermo-element that has an expansion / contraction section that expands and contracts in response to temperature, and is assembled inside the first pipe member so that the valve body moves away from the valve seat when the water temperature rises above a specified temperature and the expansion / contraction section expands.

[0012] Preferably, the automatic drainage device further includes a second thermo unit arranged in parallel with the first thermo unit and opening the flow path as the temperature of the water in the retention piping drops. The second thermo unit includes a second pipe member having a valve seat therein, a valve body that engages with the valve seat, and a second thermo element that has an expansion / contraction part that expands and contracts in response to temperature and is assembled inside the second pipe member so that when the water temperature is equal to or higher than a specified temperature and the expansion / contraction part is expanded, the valve body is pressed against the valve seat.

[0013] In the above case, it is desirable that the first thermo unit be disposed adjacent to the intersection between the first pipe line in which the first thermo unit is provided and the second pipe line in which the second thermo unit is provided.

[0014] Preferably, the first and second pipe members have the same shape and structure. In this case, the first and second pipe members are desirably configured with a central pipe section provided with a valve seat, a downstream pipe section located downstream of the central pipe section and provided with a support section that supports the tip of the expandable section, and an upstream pipe section located upstream of the central pipe section and provided with a support section that supports a spring that applies a negative force in the direction of contraction of the expandable section.

[0015] Preferably, the automatic drainage device further includes a solenoid valve that is arranged in parallel with the first thermo unit and opens and closes under timer control.

[0016] Preferably, the automatic drainage device further comprises a water meter arranged in series with the first thermo unit.

[0017] A thermo unit according to another aspect of the present invention is a thermo unit for an automatic drainage system connected to a stagnation piping in a water pipe, and includes a pipe member and first and second thermo-elements selectively attached to the inside of the pipe member and having expansion and contraction sections that expand and contract in response to temperature. The pipe member is composed of a central pipe section with a radially extending ring section provided therein, a downstream pipe section located downstream of the central pipe section, and an upstream pipe section located upstream of the central pipe section, and the ring sections integrally include a first valve seat whose diameter increases toward the upstream side and a second valve seat whose diameter increases toward the downstream side. The first thermo-element has a valve body that engages with the first valve seat, and the second thermo-element has a valve body that engages with the second valve seat. [Effects of the Invention]

[0018] The automatic drainage device of the present invention is equipped with a first thermo-unit, which can suppress the rise in water temperature in the stagnant part of the water supply pipe. Furthermore, if the automatic drainage device further includes a second thermo-unit, it can also prevent the drainage pipe from freezing in winter.

[0019] Furthermore, the structure of the thermo unit of the present invention allows a common pipe member to function as either the first thermo unit or the second thermo unit, thereby increasing the flexibility when applying it to an automatic drainage device, such as by switching thermo units depending on the season. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram showing a schematic configuration of an automatic drainage device according to an embodiment of the present invention; [Figure 2] 1A and 1B are perspective views showing the appearance of a summer thermo unit and a winter thermo unit, respectively, according to an embodiment of the present invention. [Figure 3] 1 is an exploded perspective view of a summer thermo unit according to an embodiment of the present invention; [Figure 4] 1 is an exploded cutaway view showing the internal structure of a summer thermostat unit according to an embodiment of the present invention. [Figure 5] 1 is an exploded perspective view of a winter thermo unit according to an embodiment of the present invention; [Figure 6] 1 is an exploded cutaway view showing the internal structure of a winter thermo unit according to an embodiment of the present invention. [Figure 7] FIG. 3 is a cross-sectional view of a central pipe portion (first component) of each thermo unit in the embodiment of the present invention. [Figure 8] FIG. 1(A) is a perspective view showing a thermoelement for summer use, and FIG. 1(B) is a perspective view showing a thermoelement for winter use. [Figure 9] 1 is a cross-sectional view schematically showing a state in which a summer thermo unit according to an embodiment of the present invention is used. [Figure 10] 1 is a cross-sectional view schematically showing a state in which a winter thermo unit according to an embodiment of the present invention is used. [Figure 11] 1 is a diagram showing an example of the overall configuration of an automatic drainage device equipped with a thermo unit (a summer thermo unit or a winter thermo unit) according to an embodiment of the present invention. [Figure 12] FIG. 2 is a diagram showing an example of the overall configuration of an automatic drainage device according to a first modified example of the present embodiment. [Figure 13] FIG. 10 is a diagram showing an example of the overall configuration of an automatic drainage device according to a second modified example of the present embodiment. [Figure 14] 1 is a diagram showing a known automatic drainage device connected to a stagnant piping in a water supply pipe. DETAILED DESCRIPTION OF THE INVENTION

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and description thereof will not be repeated.

[0022] <Automatic Drainage System Overview> First, an overview of an automatic drainage device 1 according to this embodiment will be described with reference to Fig. 1. The automatic drainage device 1 is installed in a stagnant section of a waterworks pipe. Specifically, similar to the known automatic drainage device 100 shown in Fig. 14, the automatic drainage device 1 is installed midway along a wastewater pipe 5 that runs from the end of a main water pipe 3 to a drainage ditch 4 as part of a drainage system. Arrow A1 in Fig. 1 indicates the direction of water flow.

[0023] The automatic drainage device 1 includes a drain pipe 11 connected directly or indirectly to a stagnation piping 3e, such as the end of a main water pipe 3, and a solenoid valve 20 and a thermo unit 30 provided in parallel to the drain pipe 11. The drain pipe 11 has, for example, a main path 11m and a sub-path 11s that bypasses the main path 11m, with the solenoid valve 20 provided in the main path 11m and the thermo unit 30 provided in the sub-path 11s. Note that, for ease of understanding, in Figure 1, the areas where water stagnates when the solenoid valve 20 and the thermo unit 30 are fully closed are indicated by hatching.

[0024] The solenoid valve 20 is normally kept fully closed, and a timer control, not shown, periodically opens the valve. This prevents a decrease in the concentration of residual chlorine in the retention pipe 3e. Periodic drainage also helps to prevent the water temperature in the main water pipe 3 from rising to some extent. However, because the water temperature in the main water pipe 3 fluctuates daily due to factors such as air temperature, raw water temperature, and water demand, there is a possibility that the water temperature situation may differ from the drainage operation, resulting in inadequate water temperature management. Furthermore, to ensure that the water temperature is lowered by drainage, the drainage time must be set to a safe level, which raises concerns about an increase in non-revenue water due to water disposal.

[0025] In contrast, the automatic drainage device 1 according to this embodiment is equipped with a thermo unit 30 in the sub-path 11s, enabling optimal water temperature management. The thermo unit 30 includes a thermo element that expands when the temperature rises, and is configured to mechanically open and close (stop or allow water to pass) the flow path depending on the water temperature. The thermo element contains, for example, paraffin wax, and expands and contracts due to changes in the volume of the paraffin wax. Therefore, according to this embodiment, water quality can be maintained using the solenoid valve 20, while water temperature can be easily managed at the same time.

[0026] Here, the automatic drainage device 1 according to this embodiment can selectively use a summer thermo unit 30A or a winter thermo unit 30B shown in Fig. 2 as the thermo unit 30. The summer thermo unit 30A is configured to open the flow path and drain the water from the retention pipe 3e when the water temperature rises, so that cold water that people find tasty can be supplied from the water main 3 to each water supply point. The winter thermo unit 30B is configured to open the flow path and drain the water from the retention pipe 3e when the water temperature drops, so that it can prevent the drain pipe 11 from freezing in winter and function as an antifreeze valve.

[0027] As shown in Figure 2, the summer thermo unit 30A and the winter thermo unit 30B have the same external shape and size, but the orientation of the valve body (flange portion) of the thermo element provided inside them is different. The differences in the internal structure between the summer thermo unit 30A and the winter thermo unit 30B will be described below.

[0028] <Structure of summer thermoelement> An example of the structure of the summer thermo unit 30A will be described with reference to Figures 3 and 4. Figure 3 is an exploded perspective view of the summer thermo unit 30A, and Figure 4 is an exploded cutaway view showing the internal structure of the summer thermo unit 30A.

[0029] The summer thermo unit 30A includes a pipe member 39 (FIG. 2) divided into three parts 31 to 33, and a thermo-element 34 and a spring 35 provided inside the pipe member 39. The three parts 31 to 33 are screwed together to form the pipe member 39. Note that in FIG. 4, the female and male threads are not shown to avoid cluttering the drawing.

[0030] The first component 31, located at the center of the pipe member 39, is a central pipe portion that integrally includes a cylindrical portion 311 that extends in the direction of flowing water and a ring portion 312 that is provided at the center inside the cylindrical portion 311. The ring portion 312 extends radially, perpendicular to (intersecting) the axis O of the cylindrical portion 311. The outer periphery of the ring portion 312 is connected to the inner circumferential surface of the cylindrical portion 311. The ring portion 312 functions as two valve seats, as will be described later, and the central hole of the ring portion 312 forms a flow path. The inner circumferential surface of the cylindrical portion 311 is female-threaded.

[0031] The second component 32, located upstream of the first component 31, is an upstream pipe section and integrally includes a cylindrical component 321 extending in the direction of flowing water and a plate-shaped support component 322 suspended across the center of the interior of the cylindrical component 321. A male thread is formed on the outer peripheral surface of the cylindrical component 321. The female thread on the cylindrical component 321 is threadedly engaged with the female thread on the inner peripheral surface of the cylindrical component 311 of the first component 31. This forms a first space 41 between the support component 322 and the ring component 312. A hexagonal bolt 323 may be provided in the axial center of the outer peripheral surface of the cylindrical component 321.

[0032] The third component 33, located downstream of the first component 32, is a downstream pipe section and, like the second component 32, integrally includes a cylindrical component 331 extending in the direction of flowing water and a plate-shaped support component 332 suspended across the center of the interior of the cylindrical component 331. A male thread is formed on the outer peripheral surface of the cylindrical component 331. The female thread on the cylindrical component 331 is threadedly engaged with the female thread on the inner peripheral surface of the cylindrical component 311 of the first component 31. This forms a second space 42 between the support component 332 and the ring component 312. In other words, the ring component 312 is located at the boundary between the first space 41 and the second space 42. A hexagonal bolt 333 may be provided at the axial center of the outer peripheral surface of the cylindrical component 331.

[0033] The thermo-element 34 includes, for example, a cylindrical sensor portion 341, a rod-shaped expandable portion 342 that extends linearly, and a ring-shaped flange portion 343 that is located between the sensor portion 341 and the rod-shaped expandable portion 342. The sensor portion 341 and the flange portion 343 are disposed in the first space 41, and the rod-shaped expandable portion 342 is disposed in the second space 42. The flange portion 343 functions as a valve body, and in the normal state engages with the inner periphery of the ring portion 312 (specifically, the summer valve seat B1 described below).

[0034] The spring 35 is located in the first space 41 and is attached to a recess 322a formed in the support portion 322 of the second component 32. The spring 35 is a compression spring that urges the sensor portion 341 of the thermo-element 34 toward the ring portion 312. The spring 35 applies a urging force in the direction in which the expandable portion 342 of the thermo-element 34 contracts. The tip of the rod-shaped expandable portion 342 of the thermo-element 34 is attached to and supported in a recess 332a formed in the support portion 332 of the third component 33.

[0035] <Winter thermoelement structure> A structural example of the winter thermo unit 30B will be described with reference to Figures 5 and 6. Figure 5 is an exploded perspective view of the winter thermo unit 30B, and Figure 6 is an exploded cutaway view showing the internal structure of the winter thermo unit 30B.

[0036] The winter thermo unit 30B includes the same tubular member 39 (components 31 to 33) and spring 35 as the summer thermo unit 30A. The only difference from the summer thermo unit 30A is that the winter thermo unit 30B includes a thermo element 36 instead of the thermo element 34.

[0037] Similar to the thermoelement 34, the thermoelement 36 includes a sensor portion 361, a rod-shaped expandable portion 362 extending linearly from the tip of the sensor portion 361, and a flange portion 363 provided in an annular shape at the tip of the sensor portion 361. However, only the sensor portion 361 is disposed in the first space 41, and the flange portion 363 and the rod-shaped expandable portion 362 are disposed in the second space 42. The flange portion 363 functions as a valve body, and in the normal state engages with the inner periphery of the ring portion 312 (specifically, the winter valve seat B2 described below).

[0038] In this way, both thermo-elements 34, 36 are attached so that the flange portions 343, 363 engage with the ring portion 312 of the first component 31, but the engaging directions (assembly directions) of the two with the ring portion 312 are different. This will be explained with reference to Figures 7 and 8.

[0039] <Thermoelement installation direction> Fig. 7 is a cross-sectional view of the first component 31. Fig. 8(A) is a perspective view showing a thermo-element 34 for summer use, and Fig. 8(B) is a perspective view showing a thermo-element 36 for winter use.

[0040] As shown in FIG. 7 , the inner circumferential surface of the ring portion 312 (the surface surrounding the central hole) includes a central cylindrical surface 312a that overlaps with the centerline C in the thickness direction (axial direction of the pipe member 39), a first tapered surface 312b located upstream of the central cylindrical surface 312a, and a second tapered surface 312c located downstream of the central cylindrical surface 312a. The first tapered surface 312b expands in diameter from its tip adjacent to the central cylindrical surface 312a toward the first space 41. The second tapered surface 312c expands in diameter from its tip adjacent to the central cylindrical surface 312a toward the second space 42. The upstream portion of the ring portion 312, including the first tapered surface 312b, functions as a summer valve seat B1, and the downstream portion, including the second tapered surface 312c, functions as a winter valve seat B2. The first tapered surface 312b and the second tapered surface 312c are typically formed symmetrically with respect to a virtual plane that overlaps with the center line C.

[0041] The flange portion 343 of the summer thermo-element 34 has a tapered shape on the telescopic portion 342 side that fits the first tapered surface 312b, and functions as a valve element that engages with the summer valve seat B1. Therefore, when assembling the thermo-element 34 to the pipe member 39, the rod-shaped telescopic portion 342 is inserted into the hole in the ring portion 312 from the upstream side (from the direction of arrow D1) (see Figures 3 and 4). A summer temperature-sensitive valve is composed of the summer valve seat B1 provided on the first component, the flange portion 343 of the thermo-element 34 that functions as the valve element, and the rod-shaped telescopic portion 342 of the thermo-element 34 that functions as the valve stem.

[0042] On the other hand, the flange portion 363 of the winter thermo-element 36 has a tapered shape on the sensor portion 361 side that fits the second tapered surface 312c, and functions as a valve element that engages with the winter valve seat B2. Therefore, when assembling the thermo-element 36 to the pipe member 39, the sensor portion 361 is inserted into the hole in the ring portion 312 from the downstream side (from the direction of arrow D2) (see Figures 5 and 6). A winter temperature-sensitive valve is composed of the winter valve seat B2 provided on the first component, the flange portion 363 of the thermo-element 36 that functions as a valve element, and the rod-shaped expandable portion 362 of the thermo-element 36 that functions as a valve stem.

[0043] <Summer thermo unit usage status> 9 is a cross-sectional view showing a typical usage state of the summer thermo unit 30A. (A) shows the thermo element 34 when the temperature of the water stored in the retention section piping 3e is below the specified temperature, and (B) shows the thermo element 34 when the temperature of the water stored in the retention section piping 3e exceeds the specified temperature. The specified temperature (operating temperature) can be freely set during the manufacture of the thermo element 34. The specified temperature of the winter thermo element 36 is similar.

[0044] Referring to FIG. 9(A), the first space 41 of the pipe member 39 is constantly in communication with the retention pipe 3e via the drain pipe 11, so water is constantly present in the first space 41. Therefore, the sensor portion 341 of the thermoelement 34 is constantly in contact with water. When the temperature of the water in the first space 41 is below a specified temperature, the rod-shaped expandable portion 342 is contracted, so the length of the rod-shaped expandable portion 342 is its initial length (typically its minimum length). At this time, the biasing force of the spring 35 presses the flange portion 343, which serves as the valve body of the thermoelement 34, against the first valve seat B1, so the temperature-sensitive valve is in a fully closed state (water-stopped state). In other words, the flow path from the first space 41 to the second space 42 (the center hole of the ring portion 312) is closed, and drainage to the wastewater pipe 5 is blocked.

[0045] On the other hand, referring to FIG. 9(B), when the temperature of the water in the first space 41 exceeds a predetermined temperature, the paraffin wax embedded in the thermoelement 34 thermally expands, causing the rod-shaped expandable portion 342 to extend. As the rod-shaped expandable portion 342 extends, the flange portion 343 serving as the valve element of the thermoelement 34 moves upstream against the biasing force of the spring 35, creating a gap between the flange portion 343 and the first valve seat B1, opening the temperature-sensitive valve. This opens the flow path (the central hole of the ring portion 312) from the first space 41 to the second space 42, allowing water to be drained through this flow path. In other words, the water that has become relatively hot due to being retained in the retention pipe 3e is drained toward the waste water pipe 5. As a result, new water from the water main pipe 3 flows into the retention pipe 3e, gradually lowering the temperature of the water in the first space 41, which is connected to the retention pipe 3e.

[0046] When the water temperature in the first space 41 falls below the specified temperature again by draining the water that has been stagnating in the stagnant portion piping 3e, the rod-shaped extensible portion 342 contracts, returning the water-passing state shown in Fig. 9(B) to the water-stopped state shown in Fig. 9(A). Therefore, according to this embodiment, it is possible to automatically maintain the water temperature below the specified temperature while reducing unnecessary drainage.

[0047] <Winter thermo unit usage status> 10 is a cross-sectional view showing a typical usage state of the winter thermo unit 30B. (A) shows the thermo element 36 when the temperature of the water stored in the retention section piping 3e is equal to or higher than the specified temperature, and (B) shows the thermo element 36 when the temperature of the water stored in the retention section piping 3e falls below the specified temperature. The specified temperature set for the winter thermo element 36 is sufficiently lower than the specified temperature set for the summer thermo element 34, and in the normal water-stopped state, the rod-shaped expandable portion 362 of the thermo element 36 is expanded.

[0048] 10(A), as described above, the first space 41 of the pipe member 39 is constantly in communication with the retention piping 3e via the drain pipe 11, so water is constantly present in the first space 41. Therefore, the sensor portion 361 of the thermoelement 36 is constantly in contact with water. When the temperature of the water in the first space 41 is equal to or higher than a specified temperature, the rod-shaped expandable portion 362 is extended, and the length of the rod-shaped expandable portion 362 is longer than its initial length (typically its minimum length). At this time, the flange portion 363 serving as the valve element of the thermoelement 36 moves upstream against the biasing force of the spring 35 and is pressed against the second valve seat B2. In other words, in the winter thermo unit 30B, when the water temperature is equal to or higher than a specified temperature, the temperature-sensitive valve is fully closed (stopped flow of water).

[0049] 10(B), when the temperature of the water in the first space 41 falls below a predetermined temperature, the rod-shaped expandable portion 362 contracts. As the rod-shaped expandable portion 362 contracts, the flange portion 363 serving as the valve element of the thermo-element 36 moves downstream due to the biasing force of the spring 35, creating a gap between the flange portion 363 and the second valve seat B2, and the temperature-sensitive valve opens. This opens the flow path (the central hole of the ring portion 312) from the first space 41 to the second space 42, allowing water to be drained through this flow path. In other words, water that has become relatively cold due to being retained in the retention pipe 3e in winter is drained toward the wastewater pipe 5. As a result, new water from the water main pipe 3 flows into the retention pipe 3e, gradually increasing the temperature of the water in the first space 41, which is connected to the retention pipe 3e.

[0050] When the water temperature in the first space 41 rises above the specified temperature again by draining the water that has been stagnating in the stagnant portion piping 3e, the rod-shaped extensible portion 362 expands, returning the water-passing state shown in FIG. 10(B) to the water-stopping state shown in FIG. 10(A). Therefore, according to this embodiment, it is possible to prevent the drain pipe 11 of the automatic drainage device 1 from freezing while reducing unnecessary drainage. As a result, it is possible to prevent damage to the drain pipe 11.

[0051] In order to appropriately prevent the entire drain pipe 11 from freezing, it is desirable that the intersection 11x between the main path 11m and the sub-path 11s be located immediately before the solenoid valve 20, as shown in Fig. 1. In other words, it is desirable that the solenoid valve 20 be provided in a position adjacent to the intersection 11x. This eliminates the problem of water continuing to stagnate in part of the main path 11m (the pipe from the intersection 11x to the solenoid valve 20) even when the thermo unit 30B is in a water-passing state, compared to when the intersection 11x and the solenoid valve 20 are located far apart.

[0052] <Overall configuration example of automatic drainage system> 11A and 11B are diagrams showing an example of the overall configuration of an automatic drainage device 1 equipped with a thermo unit 30 (summer thermo unit 30A or winter thermo unit 30B). Fig. 11A is a perspective view, and Fig. 11B is a side view.

[0053] The automatic drainage device 1 shown in Fig. 11 has a shape that can be housed in a water meter box 2 such as that shown in Fig. 14. The drainage pipe 11 of the automatic drainage device 1 is bent, for example, counterclockwise when viewed from above, and includes an upstream pipe 111, an intermediate pipe 112, and a downstream pipe 113 that are arranged parallel to one another. As an example, only the downstream pipe 113 is arranged at a higher position than the upstream pipe 111 and the intermediate pipe 112.

[0054] A stop valve 50 with a check valve and a water sampling valve 60 are provided in the upstream pipe 111. A water meter 70 is provided in the intermediate pipe 112. A solenoid valve 20 is provided in the downstream pipe 113. A flexible pipe 114 is connected to the downstream pipe 113 at one end upstream of the solenoid valve 20 and at the other end downstream of the solenoid valve 20. The portion of the downstream pipe 113 where the solenoid valve 20 is provided corresponds to the main path 11m, and the flexible pipe 114 corresponds to the sub-path 11s.

[0055] In this automatic drainage device 1, as an example, the thermo unit 30 is installed vertically at the downstream end of the flexible pipe 114. The thermo unit 30 is installed within the height range of the solenoid valve 20. This makes it possible to accommodate the thermo unit 30 as well as the automatic drainage device 1 equipped with various functions even in a narrow installation space such as the water meter box 2.

[0056] Furthermore, as described above, the summer thermo unit 30A and the winter thermo unit 30B share the same pipe member 39, so the summer thermo unit 30A and the winter thermo unit 30B can be easily swapped at the change of seasons. This prevents both a rise in water temperature in the summer and freezing in the winter. Note that the automatic drainage device 1 may use only the summer thermo unit 30A all year round.

[0057] <Variation 1> In this embodiment, it is assumed that the automatic drainage device 1 is equipped with both the solenoid valve 20 and the thermo unit 30, but the automatic drainage device does not have to be equipped with the solenoid valve 20. In other words, the automatic drainage device only needs to be equipped with at least the thermo unit 30 and have a water temperature management function.

[0058] Fig. 12 is a diagram showing an example of the overall configuration of an automatic drainage device 1A according to Modification 1 of the present embodiment, in which Fig. 12(A) is a top view and Fig. 12(B) is a side view.

[0059] The basic configuration of the drain pipe 11 of the automatic drainage device 1A is the same as that shown in Figure 11, and the drain pipe 11 includes an upstream pipe 111, an intermediate pipe 112, and a downstream pipe 113. The upstream pipe 111 is provided with a stop valve 50 with a check valve and a water sampling valve 60. The intermediate pipe 112 is provided with a water meter 70. On the other hand, the downstream pipe 113 is not provided with a solenoid valve 20. In this case, the thermo unit 30 can be attached directly to the downstream pipe 113, so the flexible pipe 114 shown in Figure 11 can be omitted.

[0060] As another modification example (not shown), the automatic drainage device may be a device that includes only the thermo unit 30 on the straight drainage pipe 11.

[0061] <Variation 2> In this embodiment, an example has been described in which the automatic drainage device 1 is equipped with one thermo unit 30, and only one of the summer thermo unit 30A and the winter thermo unit 30B is used, but both the summer thermo unit 30A and the winter thermo unit 30B may also be installed.

[0062] Fig. 13 is a diagram showing an example of the overall configuration of an automatic drainage device 1B according to Modification 2 of this embodiment. Fig. 13(A) is a perspective view, and Fig. 13(B) is a side view. Fig. 13 shows an example in which the solenoid valve 20 is not provided, as in Modification 1.

[0063] The basic configuration of the drain pipe 11 of the automatic drainage device 1B is the same as that shown in Figures 11 and 12, and the drain pipe 11 includes an upstream pipe 111, an intermediate pipe 112, and a downstream pipe 113. In addition, the upstream pipe 111 is provided with a stop valve 50 with a check valve and a water sampling valve 60. The intermediate pipe 112 is provided with a water meter 70.

[0064] The downstream piping 113 includes a main path 11n extending linearly and a detour path 11d, one end of which is connected to the main path 11n. A summer thermo unit 30A is provided in the main path 11n, and a winter thermo unit 30B is provided in the detour path 11d. The detour path 11d is disposed above the main path 11n so as to detour around it and has an inverted U shape. As shown in FIG. 13(A), the winter thermo unit 30B is provided, for example, in a linear portion of the detour path 11d that is parallel to the main path 11n. The summer thermo unit 30A is provided adjacent to an intersection 11c between the main path 11n and the upstream end of the detour path 11d. This prevents freezing due to water stagnation in the piping from the intersection 11c to the summer thermo unit 30A. In addition, one of the upstream and downstream portions of the detour 11d relative to the winter thermo unit 30B may be formed by a flexible pipe 114.

[0065] According to the automatic drainage device 1B of this modification, there is no need to switch between the summer thermo unit 30A and the winter thermo unit 30B at the change of seasons, so it can be used all year round.

[0066] <Other variations> Figures 11 to 13 show examples of the configuration of an automatic drainage device suitable for being housed in a water meter box 2, but by appropriately changing the piping configuration of the drainage pipe 11, the automatic drainage device can also be housed in other types of inspection manholes, such as manholes.

[0067] Furthermore, the location where the automatic drainage device is installed is not limited to the location shown in Figure 14, but it can also be installed in other stagnation areas, such as a branching point where multiple water pipes branch off from a looped water supply pipe.

[0068] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0069] 1, 1A, 1B automatic drainage device, 2 water meter box, 3e stagnation section piping, 11 drain pipe, 20 solenoid valve, 30 thermo unit, 30A summer thermo unit (first thermo unit), 30B winter thermo unit (second thermo unit), 31 first part (central pipe section), 32 second part (upstream pipe section), 33 third part (downstream pipe section), 34, 36 thermo element, 35 spring, 70 water meter, 311, 321, 331 cylindrical part, 312 ring part, 322, 332 support part, 341, 361 sensor part, 342, 362 rod-shaped expansion part, 343, 363 flange part (valve body), B1 summer valve seat (first valve seat), B2 winter valve seat (second valve seat).

Claims

1. An automatic drainage device that is connected to a stagnation section pipe in a water supply pipe and automatically drains water from the stagnation section pipe, A drain pipe connected directly or indirectly to the retention section piping; an electromagnetic valve provided at a midpoint of the drain pipe and normally kept in a fully closed state; a controller that periodically opens the solenoid valve in order to periodically drain the water from the retention section piping; The drain pipe includes a main path in which the solenoid valve is provided, and a sub-path that branches off from a portion of the main path upstream of the solenoid valve, bypasses the solenoid valve, and joins the main path at a portion downstream of the solenoid valve, The sub-path is provided with a thermo unit that closes the flow path of the sub-path when the temperature of the water in the stagnation section piping is equal to or lower than a specified temperature, and opens the flow path of the sub-path when the temperature of the water in the stagnation section piping exceeds the specified temperature, thereby automatically draining the water in the stagnation section piping, The thermo unit is an automatic drainage device that includes a pipe member having a valve seat therein, a valve body that engages with the valve seat, and a thermoelement that has an expansion / contraction section that expands and contracts in response to temperature, and is assembled inside the pipe member so that the valve body moves away from the valve seat in response to the expansion / contraction section expanding when the water temperature rises above a specified temperature.

2. The automatic drainage system of claim 1 further comprising a water meter disposed in series with the thermo unit.

3. The valve body is arranged upstream of the valve seat, and the expansion / contraction portion is arranged downstream of the valve seat, 3. The automatic drainage device according to claim 1, wherein the thermo unit is located upstream of the valve body and further includes a spring that applies a biasing force in a direction in which the expansion / contraction portion contracts, thereby pressing the valve body against the valve seat.

4. An automatic drainage device that is connected to a stagnation section piping in a water supply pipe and automatically drains water from the stagnation section piping, A drain pipe connected directly or indirectly to the retention section piping; a first thermo unit provided in the middle of the drain pipe and configured to open a flow path in response to a rise in the temperature of the water in the retention pipe; the first thermo unit includes a first pipe member having a valve seat therein, a valve body that engages with the valve seat, and a first thermoelement that has an expansion and contraction portion that expands and contracts in response to temperature, the first thermoelement being assembled inside the first pipe member so that the valve body moves away from the valve seat in response to the expansion and contraction portion expanding when the temperature of the water rises above a specified temperature, a second thermo unit arranged in parallel with the first thermo unit and opening a flow path in response to a decrease in the temperature of the water in the retention pipe; The second thermo unit includes a second pipe member having a valve seat therein, a valve body that engages with the valve seat, and a second thermo element that has an expansion / contraction section that expands and contracts depending on the temperature, and is assembled inside the second pipe member so that when the water temperature is above a specified temperature and the expansion / contraction section is expanded, the valve body is pressed against the valve seat.

5. 5. The automatic drainage device according to claim 4, wherein the first thermo unit is disposed adjacent to an intersection between a first pipe line in which the first thermo unit is provided and a second pipe line in which the second thermo unit is provided.

6. the first tubular member and the second tubular member have the same shape and structure; An automatic drainage device as described in claim 4 or 5, wherein the first pipe member and the second pipe member are composed of a central pipe section in which the valve seat is provided, a downstream pipe section located downstream of the central pipe section and provided with a support section that supports the tip of the expansion / contraction section, and an upstream pipe section located upstream of the central pipe section and provided with a support section that supports a spring that applies a negative force in the direction of contraction of the expansion / contraction section.

7. A thermo unit for an automatic drainage device connected to a stagnation piping in a water pipe, a pipe member including a central pipe portion having a radially extending ring portion provided therein, a downstream pipe portion located downstream of the central pipe portion, and an upstream pipe portion located upstream of the central pipe portion; a first thermo-element and a second thermo-element, each having an expansion and contraction portion that expands and contracts in response to temperature, which are selectively attached to the inside of the pipe member; the ring portion integrally includes a first valve seat whose diameter increases toward the upstream side and a second valve seat whose diameter increases toward the downstream side, A thermo unit, wherein the first thermo-element has a valve body that engages with the first valve seat, and the second thermo-element has a valve body that engages with the second valve seat.

Images