Automatic drainage device and control method for automatic drainage device

Abstract

To provide an automatic drainage device and a control method therefor that can perform drainage in an underground space simply and reliably.SOLUTION: An automatic drainage device 1 comprises a drain pipe 3 extending from a water supply pipe 2 to a drainage system 7, a solenoid valve 8 provided in an underground space S where the drain pipe 3 is laid, the solenoid valve 8 switching between a water-passing state and a cut-off state for water flowing through the drain pipe 3, and a suction part 5 provided on the drain pipe 3 and having a suction port 17 opening into the underground space S, the suction part 5 sucking water accumulated in the underground space S and flowing it into the drain pipe 3, wherein the automatic drainage device is configured to suck the water accumulated in the underground space S through the suction port 17 by a suction force generated by a low-pressure section formed in the suction part 5, and the control method is configured such that, when at least one of the conditions that the cut-off state of the solenoid valve 8 continues for a predetermined duration, or the depth of water accumulated in the underground space S reaches a predetermined depth is met, a control unit 10 switches the solenoid valve 8 from the cut-off state to the water-passing state.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an automatic drainage device installed in a water supply pipe and its control method, and particularly to a device having a function of draining water accumulated in an underground space such as a manhole where the automatic drainage device is installed.

Background Art

[0002] In order to ensure the sanitary condition of the tap water flowing through the water supply pipe, it is obligatory to ensure that the free residual chlorine concentration at the end of the pipeline is 0.1 mg / L or more. However, when stagnation occurs at the end of the pipeline or the like, there is a problem that the free residual chlorine concentration decreases over time and the water quality deteriorates.

[0003] To solve this problem, it is conceivable to constantly drain the water at the end of the pipeline or for workers to manually perform drainage work regularly, but new problems of waste of tap water and increase in working costs arise. Therefore, for example, in Patent Documents 1 and 2 below, by using an automatic drainage device to periodically drain the stagnant water, while suppressing the waste of tap water and the increase in working costs associated with maintaining water quality, the free residual chlorine concentration is kept at an appropriate value.

[0004] This automatic drainage device is composed of a waste water pipe extending from the water supply pipe to a drainage system (such as a drainage ditch provided on the ground), a solenoid valve that switches between a water passing state and a shut-off state of the water flowing through the waste water pipe, a control unit, electrical components such as a battery, etc., and these are provided in an underground space such as a manhole or a water meter box.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In an underground space where an automatic drainage device is provided, groundwater and rainwater seeping out from the inner wall tend to accumulate inside and are difficult to drain, so there is a risk that this automatic drainage device (especially its electrical components) will be submerged and malfunction. Particularly in cold regions, in order to prevent freezing in winter, the automatic drainage device is often installed at a position deeper than the freezing depth (the depth from the ground surface where the ground temperature becomes 0°C). However, the groundwater level is likely to be constantly higher than the installation depth of the automatic drainage device, increasing the risk of submersion. It is also conceivable to install an electric drainage pump in the underground space to drain water or to enhance the watertightness of the underground space. However, costs for wiring for electrical equipment, installation of the drainage pump, and renovation work for enhancing watertightness will occur, and maintenance of the drainage pump and the like will be troublesome, so practical implementation is difficult.

[0007] Therefore, an object of the present invention is to provide an automatic drainage device and a control method thereof that can simply and surely drain water in an underground space.

Means for Solving the Problems

[0008] To solve the above problems, in the present invention, a waste water pipe extending from a water supply pipe to a drainage system, a solenoid valve provided in the underground space where the waste water pipe is laid, and configured to switch between a water passing state and a shut-off state of the water flowing through the waste water pipe, a suction part provided in the waste water pipe, having a suction port opening into the underground space, and configured to suck the water accumulated in the underground space and flow it into the waste water pipe, are provided, and an automatic drainage device is configured to suck the water accumulated in the underground space from the suction port by the suction force generated by a low-pressure part formed in the suction part.

[0009] By doing so, the water accumulated in the underground space can be easily and surely drained into the drainage system through the suction part and the drain pipe, so that it is possible to avoid trouble caused by the automatic drainage device being submerged in water.

[0010] In the automatic drainage device according to the above configuration, the suction part is an ejector having a body part, a nozzle provided in the body part for jetting water sent from the water supply pipe, and a diffuser part extending to the tip side of the nozzle, and it is preferable that a low-pressure part is formed in the body part along with the jetting of water from the nozzle. By doing so, the drainage work in the underground space can be carried out by the pressure of the water flowing through the water supply pipe, that is, without using an external power source for driving a drainage pump or the like, so that no external power source connection work is required and this automatic drainage device can be widely applied.

[0011] In the automatic drainage device according to all the above configurations, it further has a control part for controlling the electromagnetic valve, and the control part has a function of switching the electromagnetic valve from the shut-off state to the water-passing state based on the duration of the shut-off state of the electromagnetic valve and the depth of the water accumulated in the underground space. The water quality of the stagnant water in the water supply pipe is related to the duration (stagnation time) of the shut-off state of the electromagnetic valve, while the depth of the water accumulated in the underground space is related to the seepage rate of groundwater and the external precipitation situation, etc. If the electromagnetic valve is switched based on only one of them, there may be a problem in either water quality maintenance or flood prevention. Thus, by performing control to switch the electromagnetic valve based on both the duration of the shut-off state of the electromagnetic valve and the depth of the water accumulated in the underground space, it is possible to achieve both water quality maintenance and flood prevention.

[0012] In the configuration of switching the electromagnetic valve based on the depth of the water accumulated in the underground space, it is preferable that it further has a water level sensor for detecting the depth of the water accumulated in the underground space. By doing so, the change in the water level in the underground space can be surely detected.

[0013] In all of the above configurations, it is preferable that the suction part is provided in the waste water pipe on the drainage system side rather than the solenoid valve. By doing so, it becomes difficult for the water sucked by the suction part to flow back to the water supply pipe side, and it is possible to prevent troubles caused by foreign matters in the groundwater flowing into the solenoid valve.

[0014] In all of the above configurations, it is preferable that the suction port is provided at a position lower than the height of the lower end of the solenoid valve. By doing so, since the water accumulated in the underground space can be drained before reaching the height of the solenoid valve, it is possible to surely prevent the solenoid valve from being submerged in water.

[0015] Also, in order to solve the above problems, in this invention, A waste water pipe extending from a water supply pipe to a drainage system, a solenoid valve provided in an underground space where the waste water pipe is laid, for switching between a water passing state and a shut-off state of the water flowing through the waste water pipe, and provided in the waste water pipe, sucking water accumulated in the underground space and flowing it into the waste water pipe, In a control method of an automatic drainage device having a suction part having a suction port opening into the underground space and a control part for controlling the solenoid valve, When at least one of the conditions that the shut-off state of the solenoid valve continues for a predetermined continuous time or the depth of the water accumulated in the underground space reaches a predetermined depth is satisfied, the control part switches the solenoid valve from the shut-off state to the water passing state. A control method of an automatic drainage device is configured to perform control.

[0016] By doing so, the water accumulated in the underground space can be drained simply and surely to the drainage system through the suction part and the waste water pipe, so that it is possible to avoid failure troubles caused by the automatic drainage device being submerged in water.

[0017] In the control method of the automatic drainage device according to the above configuration, it is preferable to detect the depth of the water accumulated in the underground space with a water level sensor. By doing so, it is possible to surely detect the change in the water level in the underground space.

Advantages of the Invention

[0018] In this invention, in the automatic drainage device, water accumulated in the underground space is sucked by the suction part and flows into the drainage pipe, and in the control method of the automatic drainage device, control is performed to switch the electromagnetic valve from the shut-off state to the water-passing state corresponding to the duration of the shut-off state of the electromagnetic valve or the depth of the water accumulated in the underground space. Therefore, drainage in the underground space can be performed simply and reliably.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0020] An embodiment of the automatic drainage device 1 according to this invention will be described with reference to the drawings. This automatic drainage device 1 is installed in parallel with the water supply pipe 2 in order to prevent the stagnation of tap water at the end of the pipeline. As shown in Figs. 1 and 2, it has a drainage pipe 3, a device main body part 4, a suction part 5, and a check valve 6.

[0021] The drainage pipe 3 extends from the water supply pipe 2 to the drainage system 7. The water supply pipe 2 and the drainage pipe 3 are always in a communicating state. In this embodiment, the drainage system 7 is a drainage ditch provided on the ground.

[0022] As shown in an enlarged view in Fig. 2, the apparatus main body 4 includes a solenoid valve 8, a water level sensor 9, a control unit 10, a water meter 11, and a water sampling valve 12. The apparatus main body 4 is provided in the underground space S where the waste water pipe 3 is laid. The underground space S in this embodiment is the internal space of the manhole 13. Note that the apparatus main body 4 may be provided in the water meter box.

[0023] The solenoid valve 8 has a function of switching between a water passing state and a shut-off state of the water flowing through the waste water pipe 3. The water level sensor 9 has a function of detecting the depth of the water accumulated in the underground space S. The control unit 10 has a function of switching between the water passing state and the shut-off state of the solenoid valve 8 based on the duration of the shut-off state of the solenoid valve 8 measured by the timer function of the control unit 10 and the depth of the water accumulated in the underground space S detected by the water level sensor 9. The water meter 11 has a meter function for measuring the volume of the water flowing through the apparatus main body 4 (waste water pipe 3). The water sampling valve 12 has a function of taking out the tap water flowing through the water supply pipe 2 by opening the valve during regular water quality inspections.

[0024] The suction part 5 is provided in the middle of the waste water pipe 3 and has a function of sucking the water accumulated in the underground space S and flowing it to the downstream side of the waste water pipe 3. The suction part 5 according to this embodiment is an ejector having a body part 14, a nozzle 15, and a diffuser part 16 as shown in Fig. 3. The body part 14 is a cylindrical member, and a suction port 17 opening downward into the underground space S is formed at its lower part. A filter 18 for preventing the suction of turbidity contained in the groundwater is provided at the suction port 17. The suction port 17 is provided at a position lower than the height of the lower end of the solenoid valve 8. The nozzle 15 is provided inside the body part 14 and has a function of injecting the water sent from the water supply pipe 2 through the waste water pipe 3 toward the downstream side of the waste water pipe 3. The diffuser part 16 is a cylindrical member whose middle part is slightly reduced in diameter and extends to the tip side of the nozzle 15 (body part 14).

[0025] When tap water sent from the water supply pipe 2 (refer to arrow f1 in Fig. 3) is jetted from the nozzle 15 at high speed, a low-pressure area is formed inside the suction part 5 (near the outlet of the nozzle 15 in the body part 14) along with the jet. This low-pressure area generates a suction force, and the groundwater accumulated in the underground space S is sucked into the body part 14 through the suction port 17 formed therein (refer to arrow f2 in Fig. 3). The sucked groundwater is drained to the drainage system 7 through the diffuser part 16 and the drainage pipe 3 together with the tap water jetted from the nozzle 15 (refer to arrow f3 in Fig. 3). In addition, in order to enable drainage at a lower position, a suction pipe extending downward from the suction port 17 can also be attached.

[0026] The check valve 6 is provided in the drainage pipe 3 on the downstream side of the suction part 5. This check valve 6 has a function of preventing the water in the drainage pipe 3 or the drainage system 7 (downstream of the solenoid valve 8) from flowing backward and foreign matters from entering the solenoid valve 8 and the water supply pipe 2, and preventing stagnant water from accumulating in the underground space S when the solenoid valve 8 is in the cut-off state.

[0027] The control method of the above automatic drainage device 1 will be described. This control method is applied to an automatic drainage device 1 having a drainage pipe 3 extending from the water supply pipe 2 to the drainage system 7, a solenoid valve 8 provided in the underground space S where the drainage pipe 3 is laid and switching between a water passing state and a cut-off state of the water flowing through the drainage pipe 3, a suction part 5 provided in the drainage pipe 3 and having a suction port 17 opening into the underground space S for sucking the water accumulated in the underground space S and flowing it into the drainage pipe 3, and a control part 10 for controlling the solenoid valve 8.

[0028] In this control method, when at least one of the following conditions is satisfied by the timer function of the control unit 10: (a) when the closed state of the solenoid valve 8 continues for a predetermined duration, or (b) when the depth of the water accumulated in the underground space S detected by the water level sensor 9 reaches a predetermined depth, the control unit 10 is configured to perform control to switch the solenoid valve 8 from the closed state to the water passing state. That is, the solenoid valve 8 is controlled to operate independently corresponding to the respective timings of (a) and (b) above. The solenoid valve 8 switched to the water passing state is switched back to the closed state after a predetermined time corresponding to the time when the drainage of the stagnant water in the water supply pipe 2 or the drainage in the underground space S is completed.

[0029] The above automatic drainage device 1 has a suction part 5 that sucks the water accumulated in the underground space S and flows it into the drainage pipe 3, and the water accumulated in the underground space S can be drained to the drainage system 7 through the suction part 5 and the drainage pipe 3. Therefore, it is possible to avoid failure troubles caused by the automatic drainage device 1 being submerged in water.

[0030] Also, since the above automatic drainage device 1 uses the suction part 5 as an ejector, the drainage work in the underground space S can be performed by the pressure of the water flowing through the water supply pipe 2, that is, without using an external power source for driving a drainage pump or the like. Therefore, it is not necessary to perform work such as drawing in an external power source, and this automatic drainage device 1 can be widely applied. If the work of drawing in an external power source can be easily performed, other means such as an electric pump can also be used for the suction part 5.

[0031] Also, the above automatic drainage device 1 further has a control unit 10 that controls the solenoid valve 8, and the control unit 10 is configured to have a function of switching the solenoid valve 8 from the closed state to the water passing state based on the duration of the closed state of the solenoid valve 8 and the depth of the water accumulated in the underground space S. Therefore, by performing control to switch the solenoid valve 8 based on both the duration of the closed state of the solenoid valve 8 and the depth of the water accumulated in the underground space S, it is possible to achieve both water quality maintenance and prevention of submersion.

[0032] In addition, since the above-described automatic drainage device 1 further includes a water level sensor 9 for detecting the depth of water accumulated in the underground space S, it is possible to reliably detect changes in the water level in the underground space S.

[0033] In addition, since the above-described automatic drainage device 1 is configured such that the suction part 5 is provided in the drainage pipe 3 on the drainage system 7 side rather than the solenoid valve 8, the water sucked by the suction part 5 is less likely to flow back to the water supply pipe 2 side, and it is possible to prevent troubles caused by foreign matters in the groundwater flowing into the solenoid valve 8.

[0034] In addition, since the above-described automatic drainage device 1 is configured such that the suction port 17 is provided at a position lower than the height of the lower end of the solenoid valve 8, it is possible to drain the water accumulated in the underground space S before reaching the height of the solenoid valve 8, and it is possible to reliably prevent the solenoid valve 8 from being submerged.

[0035] The control method of the above-described automatic drainage device 1 is such that when at least one of the conditions is satisfied, that is, when the shut-off state of the solenoid valve 8 continues for a predetermined continuous time or when the depth of water accumulated in the underground space S reaches a predetermined depth, the control unit 10 performs control to switch the solenoid valve 8 from the shut-off state to the water-passing state, so that the water accumulated in the underground space S can be drained to the drainage system 7 through the suction part 5 and the drainage pipe 3. Therefore, it is possible to avoid failure troubles caused by the automatic drainage device 1 being submerged.

[0036] In addition, since the control method of the above-described automatic drainage device 1 is configured to detect the depth of water accumulated in the underground space S with the water level sensor 9, it is possible to reliably detect changes in the water level in the underground space S.

[0037] In the above description, the solenoid valve 8 is controlled by the control unit 10 to discharge the water accumulated in the underground space S. However, as shown as another example in Fig. 4, a waste water pipe 3 extending from the water supply pipe 2 to the drainage system 7, and a suction unit 5 provided in the waste water pipe 3, having a suction port 17 opening into the underground space S for sucking the water accumulated in the underground space S and flowing it into the waste water pipe 3. The automatic drainage device 1 can be configured to suck the water accumulated in the underground space S from the suction port 17 by the suction force generated by the low-pressure part formed in the suction unit 5.

[0038] Since the drainage function by the suction unit 5 of this automatic drainage device 1 is always exerted, it is possible to surely prevent water from accumulating in the underground space S. Since the configuration and operation of this suction unit 5 are common to those described above, the description thereof is omitted.

[0039] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. Therefore, the scope of the present invention is shown not by the above description but by the claims, and it is intended that the claims include the meaning equivalent to the claims and all modifications.

Explanation of Signs

[0040] 1 Automatic drainage device 2 Water supply pipe 3 Waste water pipe 4 Device main body part 5 Suction unit 6 Check valve 7 Drainage system 8 Solenoid valve 9 Water level sensor 10 Control unit 11 Water meter 12 Water sampling valve 13 Manhole 14 Body part 15 Nozzle 16 Diffuser part 17 Suction port 18 Filter S Underground space

Claims

1. A drainage pipe (3) extending from the water supply pipe (2) to a drainage system (7); a solenoid valve (8) provided in an underground space (S) in which the drainage pipe (3) is arranged, for switching between a water flow state and a cut-off state of the water flowing through the drainage pipe (3); a suction section (5) provided in the drainage pipe (3) and having a suction port (17) opening into the underground space (S) for sucking in water accumulated in the underground space (S) and discharging it into the drainage pipe (3); The automatic drainage device is configured to suck in water accumulated in the underground space (S) from the suction port (17) by the suction force generated by a low pressure section formed in the suction section (5).

2. The automatic drainage device according to claim 1, wherein the suction section (5) is an ejector having a body section (14), a nozzle (15) provided in the body section (14) for spraying water sent from the water supply pipe (2), and a diffuser section (16) extended from the tip side of the nozzle (15), and the low pressure section is formed within the body section (14) as water is sprayed from the nozzle (15).

3. An automatic drainage device as described in claim 1 or 2, further comprising a control unit (10) for controlling the solenoid valve (8), the control unit (10) having a function of switching the solenoid valve (8) from a shut-off state to a water-passing state based on the duration of the shut-off state of the solenoid valve (8) and the depth of water accumulated in the underground space (S).

4. 4. The automatic drainage system according to claim 3, further comprising a water level sensor (9) for detecting the depth of water accumulated in the underground space (S).

5. 3. The automatic drainage device according to claim 1, wherein the suction section (5) is provided on the drainage pipe (3) closer to the drainage system (7) than the solenoid valve (8).

6. 3. The automatic drainage device according to claim 1, wherein the suction port (17) is provided at a position lower than the height of a lower end of the solenoid valve (8).

7. A control method for an automatic drainage system including a wastewater pipe (3) extending from a water supply pipe (2) to a drainage system (7), an electromagnetic valve (8) provided in an underground space (S) to which the wastewater pipe (3) is provided and switching between a water flow state and a blocked state of water flowing through the wastewater pipe (3), a suction unit (5) provided in the wastewater pipe (3) and having a suction port (17) opening into the underground space (S) for sucking in water accumulated in the underground space (S) and discharging it into the wastewater pipe (3), and a control unit (10) for controlling the solenoid valve (8), A control method for an automatic drainage device, characterized in that the control unit (10) controls the solenoid valve (8) to switch from a shut-off state to a water-passing state when at least one of the following conditions is met: when the shut-off state of the solenoid valve (8) continues for a predetermined duration, or when the depth of water accumulated in the underground space (S) reaches a predetermined depth.

8. 8. The method for controlling an automatic drainage system according to claim 7, further comprising the step of detecting the depth of water accumulated in the underground space (S) by a water level sensor (9).

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