JP7847036B2 - Manholes, drainage piping systems, and manhole switching members - Google Patents

Description

This invention relates to manholes, drainage piping systems, and manhole switching members.

For example, Patent Document 1 discloses a drainage piping system that allows for the installation of temporary toilets during disasters such as earthquakes. The drainage piping system comprises a first drainage pipe connected to a water storage tank at its upstream end, a second drainage pipe connected to a main sewer line at its downstream end, a third drainage pipe connected to a wastewater storage tank at its downstream end, and a drainage manhole capable of switching the drainage flow path. A manhole to which a temporary toilet can be connected is provided in the middle of the first drainage pipe. The drainage manhole capable of switching the drainage flow path includes an inlet connected to the downstream end of the first drainage pipe, a first outlet connected to the upstream end of the second drainage pipe, and a second outlet connected to the upstream end of the third drainage pipe.

In the drainage piping system disclosed in Patent Document 1, a temporary toilet is connected to a manhole provided in the first drainage pipe during a disaster. When the main sewer line is usable, the second outlet of the drainage manhole is closed. This allows wastewater, including sewage discharged from the temporary toilet, to flow through the first drainage pipe along with the water flowing from the storage tank. The wastewater then flows from the inlet to the first outlet in the drainage manhole and is discharged into the main sewer line through the second drainage pipe. Conversely, when the main sewer line is unusable, the first outlet of the drainage manhole is closed. This allows wastewater discharged from the temporary toilet to flow from the inlet to the second outlet in the drainage manhole and is discharged into the storage tank through the third drainage pipe.

Japanese Patent Publication No. 2014-40723

Incidentally, in a drainage manhole where the drainage flow path can be switched as described above, it is possible to use the inlet and outlet in reverse. In this case, the drainage manhole has, for example, a first inlet, a second inlet, and an outlet. The drainage piping system in this case includes, for example, an inlet pipeline to which a drainage facility is connected, a flushing water pipeline to which a water supply tank is connected, and an outlet pipeline located downstream of the inlet pipeline and flushing water pipeline, to which the main sewer line is connected. The flushing water pipeline is configured to allow the installation of a temporary toilet. The downstream end of the inlet pipeline, the downstream end of the flushing water pipeline, and the upstream end of the outlet pipeline are connected to the drainage manhole. In this case, the inlet pipeline to which the drainage facility is connected is connected to the first inlet of the drainage manhole, and the flushing water pipeline to which the water supply tank is connected is connected to the second inlet. The outlet of the drainage manhole is connected to the outlet pipeline.

In this drainage piping system, under normal circumstances, for example, the second inlet of the drain manhole is closed and the first inlet is open. Therefore, under normal circumstances, wastewater discharged from the drainage facility can flow from the inlet pipeline through the first inlet of the drain manhole to the outlet pipeline. On the other hand, in the event of a disaster, for example, a temporary toilet is installed in the flushing water pipeline. Then, in the drain manhole, the first inlet is closed and the second inlet is opened. Therefore, in the event of a disaster, wastewater containing excrement discharged from the temporary toilet can flow from the flushing water pipeline through the second inlet to the outlet pipeline, along with water flowing from the water supply tank.

In a drainage piping system like this, wastewater could not flow into the manhole from either the closed first or second inlet. For example, during a disaster, the first inlet, to which the inflow pipeline carrying wastewater from the drainage system is connected, is closed. Therefore, during a disaster, the wastewater discharged from the drainage system is blocked at the closed first inlet and cannot be discharged into the outflow pipeline, rendering the drainage system unusable.

Here, it is preferable that the drainage system can be used even during a disaster, and that the wastewater discharged from the drainage system can be discharged into the outflow pipeline. However, it is undesirable for the wastewater flowing through the manhole to flow back into the inflow pipeline during a disaster. Furthermore, in the above drainage piping system, it is preferable that, even during normal times, water can be flowed through the flushing water pipeline for purposes such as cleaning, and discharged into the outflow pipeline. However, it is undesirable for the wastewater flowing through the manhole to flow back into the flushing water pipeline during normal times.

The above is merely one example, and a manhole with the following configuration may be desirable. Specifically, in a manhole with a switchable flow path, a configuration is desirable that, for example, when the first inlet is closed, prevents water from flowing back into the first inlet while allowing water to flow into the manhole body from the first inlet. Furthermore, in a manhole, a configuration is desirable that, for example, when the second inlet is closed, prevents water from flowing back into the second inlet while allowing water to flow into the manhole body from the second inlet.

The present invention has been made in view of the above points, and its object is to provide a manhole, a drainage piping system, and a manhole switching member, comprising a manhole body having a first inlet, a second inlet, and an outlet formed therein, and a switching member that can be selectively attached to the first inlet and the second inlet, wherein water can flow into the manhole body from the inlet to which the switching member is attached, while preventing water from flowing back into the inlet to which the switching member is attached.

The manhole according to the present invention comprises a manhole body, a switching member, and a passage permitting means. The manhole body has a bottomed cylindrical body section with a first inlet, a second inlet, and an outlet formed therein, and an inspection cylinder section connected to one end of the cylindrical body section, with an inspection port formed therein. The switching member is detachably attached to the inside of the cylindrical body section and can be repositioned between a first switching position, which is attached to the first inlet while opening the second inlet, and a second switching position, which is attached to the second inlet while opening the first inlet. The passage permitting means is provided on the switching member and allows water flowing in one direction to pass through, and blocks water flowing in the opposite direction. When the switching member is positioned at the first switching position, the passage permitting means is configured to allow water to flow from the first inlet into the manhole body and to block water flowing from inside the manhole body toward the first inlet. Furthermore, the passage permitting means is configured such that, when the switching member is positioned at the second switching position, water can flow from the second inlet into the manhole body, and water flowing from the manhole body towards the second inlet is blocked.

According to the aforementioned manhole, when the switching member is positioned at the first switching position and attached to the first inlet, water can flow from the second inlet to the outlet. At this time, the passage permitting means prevents water from flowing back into the first inlet while allowing water to flow into the manhole body from the first inlet. Furthermore, when the switching member is positioned at the second switching position and attached to the second inlet, water can flow from the first inlet to the outlet. At this time, the passage permitting means prevents water from flowing back into the second inlet while allowing water to flow into the manhole body from the second inlet. Thus, by providing a passage permitting means on the switching member, it is possible to allow water to flow into the manhole body from the inlet to which the switching member is attached, while preventing water from flowing back into the inlet to which the switching member is attached.

According to a preferred embodiment of the present invention, the switching member has a switching body having a communication port formed therein that communicates with the first inlet when in the first switching position and with the second inlet when in the second switching position. The passage permitting means has a valve body that can open and close the communication port from the outside of the switching member and can contact the switching body.

According to the above embodiment, when the valve is in the first switching position, the valve body closes the communication port that communicates with the first inlet, thereby preventing water from flowing back from the manhole body to the first inlet. When the valve is in the first switching position, the valve body opens the communication port, allowing water to flow from the first inlet into the manhole body. Similarly, when the valve is in the second switching position, the valve body closes the communication port that communicates with the second inlet, preventing water from flowing back from the manhole body to the second inlet. When the valve is in the second switching position, the valve body opens the communication port, allowing water to flow from the second inlet into the manhole body.

According to another preferred embodiment of the present invention, the first and second inlets are formed on the sides of the main body cylindrical portion. The manhole body has a bottom surface positioned below the lower end of the first inlet and spaced further apart from the lower end of the second inlet.

According to the above embodiment, when the switching member is positioned in the first switching position, water flowing into the manhole body from the second inlet falls to the bottom surface of the manhole body. Since the bottom surface of the manhole body is spaced lower than the lower end of the first inlet, water on the bottom surface is less likely to flow back into the first inlet. Furthermore, when the switching member is positioned in the second switching position, water flowing into the manhole body from the first inlet falls to the bottom surface of the manhole body. Since the bottom surface of the manhole body is spaced lower than the lower end of the second inlet, water on the bottom surface is less likely to flow back into the second inlet.

According to another preferred embodiment of the present invention, in a plan view, the angle formed by the central axis of the first inlet and the central axis of the outlet, and the angle formed by the central axis of the second inlet and the central axis of the outlet, are obtuse angles.

According to the above embodiment, water flowing into the manhole body from the first or second inlet can reach the outlet while maintaining its momentum. Therefore, the water flowing into the manhole body from the first or second inlet can be easily discharged to the outside through the outlet.

The drainage piping system according to the present invention comprises any of the above-described manholes, a drainage facility for discharging wastewater, a first inlet pipe connected to the first inlet of the manhole, a water storage means for storing water, a second inlet pipe connected to the water storage means and the second inlet of the manhole, and an outlet pipe connected to the outlet of the manhole. A temporary toilet is configured to be attachable to either the second inlet pipe or the outlet pipe.

According to the drainage piping system described above, when draining wastewater discharged from the drainage facility into the outflow pipeline, the manhole switching member is positioned at the second switching position and attached to the second inlet. This opens the first inlet, allowing the wastewater discharged from the drainage facility to be discharged from the first inlet through the first inlet into the outflow pipeline. Here, since the switching member is provided with a passage permission means, when the switching member is positioned at the second switching position, the passage permission means prevents the wastewater that has flowed into the manhole body from the first inlet from flowing back into the second inlet, while, for example, when water flows through the second inlet pipeline, the water flowing through the second inlet pipeline can be allowed to flow into the manhole body from the second inlet. Furthermore, for example, when a temporary toilet is installed, the manhole switching member is positioned at the first switching position and attached to the first inlet. This opens the second inlet, allowing the wastewater discharged from the temporary toilet to be discharged into the outflow pipeline together with the water stored in the water storage means. Here, since the switching member is equipped with a passage permission mechanism, when the switching member is positioned in the first switching position, the passage permission mechanism prevents wastewater discharged from the temporary toilet from flowing back into the first inlet. Furthermore, even when the switching member is positioned in the first switching position, wastewater discharged from the drainage system can be allowed to flow into the manhole body from the first inflow pipe through the first inlet.

The switching member for a manhole according to the present invention is a switching member for a manhole that is detachably attached to the inside of the main cylindrical portion of the manhole body, in a manhole body having a bottomed cylindrical main body portion with a first inlet, a second inlet, and an outlet formed thereon, and an inspection cylindrical portion connected to one end of the main cylindrical body portion with an inspection port formed thereon. The switching member is configured to be repositionable between a first switching position in which it is attached to the first inlet while the second inlet is open, and a second switching position in which it is attached to the second inlet while the first inlet is open. The switching member is provided with a passage permitting means that allows water flowing in one direction to pass through and blocks water flowing in the opposite direction. When the switching member is positioned in the first switching position, the passage permitting means is configured to allow water to flow from the first inlet into the manhole body and to block water flowing from inside the manhole body toward the first inlet. The passage permitting means is configured such that, when the switching member is positioned at the second switching position, water can flow from the second inlet into the manhole body, and water flowing from the manhole body towards the second inlet is blocked.

According to the switching member, when the switching member is positioned at the first switching position and attached to the first inlet of the manhole, water can flow from the second inlet to the outlet in the manhole. At this time, the passage permitting means of the switching member prevents water from flowing back into the first inlet while allowing water to flow into the manhole body from the first inlet. Furthermore, when the switching member is positioned at the second switching position and attached to the second inlet of the manhole, water can flow from the first inlet to the outlet in the manhole. At this time, the passage permitting means of the switching member prevents water from flowing back into the second inlet while allowing water to flow into the manhole body from the second inlet. In this way, the passage permitting means of the switching member allows water to flow into the manhole body from the inlet to which the switching member is attached, while preventing water from flowing back into the inlet to which the switching member is attached.

According to the present invention, a manhole, a drainage piping system, and a manhole switching member are provided, comprising a manhole body having a first inlet, a second inlet, and an outlet, and a switching member that can be selectively attached to the first and second inlets, wherein water can flow into the manhole body from the inlet to which the switching member is attached, while preventing water from flowing back into the inlet to which the switching member is attached.

This is a schematic plan view showing the drainage piping system according to the embodiment. This is a schematic front view showing the drainage piping system according to the embodiment. This is a schematic front view showing the drainage piping system according to the embodiment. This is a schematic side view showing the drainage piping system according to the embodiment. This is a front view of a manhole according to an embodiment. This is a plan view of a manhole according to an embodiment, showing the state in which the switching member is positioned at the first switching position. This is a plan view of a manhole according to an embodiment, showing the state in which the switching member is positioned at the second switching position. This is a cross-sectional view of the box at the VIII-VIII section in Figure 6. This is a cross-sectional view of the manhole in the IX-IX section shown in Figure 7. This is a cross-sectional view of the trough at the X-X section in Figure 7. This is a perspective view of the switching component. This is a perspective view of the switching member, showing the valve body in the open position. This diagram shows the switching member as viewed from the valve body side. This is a diagram showing the switching member as viewed from the opposite side of the valve body. Figure 13 is a cross-sectional view of the switching member in the XV-XV section. This is a diagram corresponding to Figure 8, showing the valve body of the passage permission mechanism in the state where the communication port is open. This is a diagram corresponding to Figure 9, showing the valve body of the passage permission mechanism in the state where the communication port is open. This diagram shows the switching body side of the valve body of the passage permission mechanism. This is a schematic plan view showing a drainage piping system according to another embodiment. This is a schematic front view showing a drainage piping system according to another embodiment. This is a schematic plan view showing a drainage piping system according to another embodiment. This is a schematic plan view showing a bathtub according to another embodiment.

The following describes embodiments of a drainage piping system with a manhole according to the present invention, with reference to the drawings. However, the embodiments described below are merely one embodiment of the present invention and are not intended to limit the invention. Furthermore, the same reference numerals are used for components and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate.

<Implementation>
Figure 1 is a schematic plan view showing the drainage piping system 1 according to this embodiment. Figures 2 and 3 are schematic front views showing the drainage piping system 1 according to this embodiment. Figure 3 shows the drainage piping system 1 with a temporary toilet 4 attached. Figure 4 is a schematic side view showing the drainage piping system 1 according to this embodiment.

In this embodiment, the manhole 50 is capable of switching the water flow path. In this embodiment, the manhole 50 is capable of switching the drainage flow path. The manhole 50 is provided in the drainage piping system 1 and is capable of switching the drainage flow path of the drainage piping system 1. As shown in Figure 1, under normal circumstances, the drainage piping system 1 discharges wastewater from the drainage equipment 6 within the building 5 towards the main sewer pipe 8. On the other hand, in the event of a disaster such as an earthquake, the drainage piping system 1 is used as a system with a temporary toilet 4 installed, as shown in Figure 3, and discharges wastewater containing excrement from the temporary toilet 4 to the main sewer pipe 8, etc.

Here, wastewater includes sewage discharged from daily life, such as from toilets, kitchen sinks, and baths, as well as rainwater. Drainage equipment 6 is equipment that discharges wastewater, such as toilets, baths, and kitchen sinks. In this embodiment, as shown in Figure 1, drainage equipment 6 is located inside building 5, but it may also be located outdoors (for example, in a park).

As shown in Figure 1, the drainage piping system 1 comprises a first inlet pipe 10, a second inlet pipe 20, an outlet pipe 30, and a manhole 50.

In the following explanation, water and wastewater flow from upstream to downstream. The upstream side refers to the drainage facility 6 side or the water supply tank 26 side (see Figure 1). The downstream side refers to the main sewer pipe 8 side.

The first inlet pipeline 10, the second inlet pipeline 20, and the outlet pipeline 30 are buried underground. As shown in Figure 1, the first inlet pipeline 10 is a pipeline that carries wastewater discharged from the drainage facility 6 to the outlet pipeline 30. The downstream end of the first inlet pipeline 10 is connected to the manhole 50. Multiple drainage facilities 6 are connected to a portion of the first inlet pipeline 10.

In this embodiment, a connecting manhole 12 is provided in the middle of the first inflow pipeline 10. The connecting manhole 12 connects the portion of the first inflow pipeline 10 upstream of the manhole 12 to the portion of the first inflow pipeline 10 downstream of the manhole 12. Furthermore, a branch pipeline 14 is connected to the connecting manhole 12, and the drainage facility 6 is connected via the branch pipeline 14. That is, the upstream end of the branch pipeline 14 is connected to the drainage facility 6, and the downstream end of the branch pipeline 14 is connected to the connecting manhole 12. Here, the first inflow pipeline 10 and the drainage facility 6 are in communication via the connecting manhole 12 and the branch pipeline 14.

As shown in Figure 2, a vertically extending riser pipe 15 is connected to the upper end of the connection manhole 12 (for example, an inspection opening (not shown) that opens upwards in the connection manhole 12). A cover 16 is attached to the riser pipe 15. In this embodiment, a temporary toilet 4 (see Figure 3) is not attached to the connection manhole 12 during a disaster; however, a temporary toilet 4 may be attached to the connection manhole 12 (more specifically, the riser pipe 15 connected to the inspection opening of the connection manhole 12).

As shown in Figure 1, in this embodiment, the number of drainage facilities 6 connected to the first inflow pipeline 10 is five, but this is not particularly limited. Here, one connection manhole 12 is connected to one drainage facility 6, and one branch pipeline 14 is connected to each drainage facility 6 and each connection manhole 12. However, multiple drainage facilities 6 may be connected to one connection manhole 12, and multiple connection manholes 12 may be connected to one drainage facility 6. Furthermore, multiple branch pipelines 14 may be connected to one connection manhole 12, and multiple branch pipelines 14 may be connected to one drainage facility 6.

As shown in Figure 3, the second inlet pipe 20 is a pipe to which a temporary toilet 4 can be attached. The second inlet pipe 20 is a pipe that carries wastewater containing excrement discharged from the temporary toilet 4 to the outlet pipe 30. In this embodiment, as shown in Figure 1, a toilet connection manhole 22 is provided in the middle of the second inlet pipe 20. As shown in Figure 3, a temporary toilet 4 can be connected to the toilet connection manhole 22. Here, the number of toilet connection manholes 22 is three, but is not particularly limited. The number of toilet connection manholes 22 is determined according to the number of temporary toilets 4 to be installed in the drainage piping system 1. The multiple toilet connection manholes 22 are arranged at equal intervals, but the spacing between adjacent toilet connection manholes 22 may differ.

In this embodiment, the toilet connection manhole 22 is a bottomed cylindrical shape. As shown in Figure 2, the toilet connection manhole 22 has an upwardly opening mounting opening 24. A lid 25 (see Figure 2) and the toilet bowl 4a of the temporary toilet 4 (see Figure 3) can be selectively attached to this mounting opening 24. Here, a vertically extending riser pipe 24a is connected to the mounting opening 24, and the lid 25 and the toilet bowl 4a of the temporary toilet 4 can be selectively attached via the riser pipe 24a. Here, being attached to the mounting opening 24 means being attached to the riser pipe 24a connected to the mounting opening 24. For example, under normal circumstances, as shown in Figure 2, the lid 25 is attached to the mounting opening 24, and the mounting opening 24 is closed by the lid 25. As shown in Figure 3, when using the temporary toilet 4, the lid 25 is removed from the mounting opening 24, and the toilet bowl 4a of the temporary toilet 4 is attached to the mounting opening 24. The wastewater discharged from the temporary toilet 4 is discharged into the second inflow pipe 20 through the toilet connection manhole 22.

In this embodiment, a water supply tank 26 is connected to the second inflow pipeline 20. More specifically, a water supply gate 28 is connected to the upstream end of the second inflow pipeline 20, and the water supply tank 26 is connected via the water supply gate 28. A manhole 50 is connected to the downstream end of the second inflow pipeline 20. The water supply tank 26 is a tank that stores water to be flowed into the second inflow pipeline 20, and is an example of a water storage means. The water supply tank 26 is connected to the upstream end of the second inflow pipeline 20 and supplies water into the second inflow pipeline 20 from the upstream end of the second inflow pipeline 20. For example, rainwater is stored in the water supply tank 26. However, the water supply tank 26 only needs to store water, and it may be relatively clean water that does not contain foreign matter, for example. The water supply tank 26 is different from the drainage equipment 6 and does not store sewage. The water supply tank 26 has a water inlet 27 through which the water inside is discharged. The water supply tank 26 may be buried underground or placed above ground.

The water supply gate 28 is configured to open and close the upstream end of the second inlet pipeline 20. When the upstream end of the second inlet pipeline 20 is closed by the water supply gate 28, water in the water supply tank 26 is prevented from flowing into the second inlet pipeline 20. On the other hand, when the upstream end of the second inlet pipeline 20 is opened by the water supply gate 28, water in the water supply tank 26 can flow into the second inlet pipeline 20. The specific configuration of the water supply gate 28 is not particularly limited, and a configuration of a conventional water supply gate can be used. The water supply gate 28 may be opened and closed manually by an operator, or it may be opened and closed automatically by electrical control. In this embodiment, when the water supply gate 28 is opened, water in the water supply tank 26 flows into the second inlet pipeline 20. Due to the water flow velocity at this time, the wastewater discharged from the temporary toilet 4 in the second inflow pipe 20 flows together with the water towards the outflow pipe 30.

As shown in Figure 1, the outflow pipeline 30 is a pipeline that carries wastewater discharged from the drainage facility 6, which flows from the first inflow pipeline 10, and sewage discharged from the temporary toilet 4, which flows from the second inflow pipeline 20, to the main sewer line 8, etc. In this embodiment, the upstream end of the outflow pipeline 30 is connected to the manhole 50. The downstream end of the outflow pipeline 30 is connected to the main sewer line 8.

In this embodiment, a storage tank 32 is connected to a portion of the outflow pipeline 30. The storage tank 32 is a tank for storing wastewater, such as sewage discharged from a temporary toilet 4. Here, when the main sewer pipe 8 is damaged and wastewater cannot flow into the main sewer pipe 8, the wastewater is discharged into the storage tank 32. The storage tank 32 has a sealed space inside. Because the storage tank 32 is sealed, it is difficult for foul odors generated from the wastewater inside the storage tank 32 to leak to the outside. In this embodiment, the storage tank 32 is buried underground, but it may also be located above ground.

In this embodiment, as shown in Figure 4, a switching valve 35 is provided in the middle of the outflow pipeline 30. A storage tank 32 is connected to this switching valve 35. The switching valve 35 switches the flow path of the wastewater. The switching valve 35 is a bottomed cylindrical shape. The switching valve 35 has a switching inlet 36 to which the portion of the outflow pipeline 30 upstream of the switching valve 35 is connected, a first switching outlet 37a to which the portion of the outflow pipeline 30 downstream of the switching valve 35 is connected, and a second switching outlet 37b connected to the storage tank 32. For example, the switching inlet 36 and the first switching outlet 37a are formed on the side of the switching valve 35 and open to the side. The second switching outlet 37b is formed at the bottom of the switching valve 35 and opens downward. The storage tank 32 is connected to the second switching outlet 37b via a connecting pipeline 38. Here, the second switching outlet 37b is connected to the upstream end of the connecting pipeline 38, and the storage tank 32 is connected to the downstream end of the connecting pipeline 38.

Although not shown in the diagram, the switching valve 35 is equipped with a switching closure member capable of closing the second switching outlet 37b. Here, when the second switching outlet 37b is closed by the switching closure member, the first switching outlet 37a remains open. Therefore, when the switching closure member closes the second switching outlet 37b, wastewater flowing into the outflow pipeline 30 is discharged to the main sewer pipe 8 through the first switching outlet 37a. On the other hand, when the switching closure member opens the second switching outlet 37b, wastewater flowing into the outflow pipeline 30 flows towards the second switching outlet 37b before reaching the first switching outlet 37a, and is discharged to the storage tank 32 through the second switching outlet 37b.

In this embodiment, a downstream backflow prevention valve 40 and a public manhole 42 are provided in the middle section of the outflow pipeline 30. The downstream backflow prevention valve 40 prevents wastewater discharged into the main sewer pipe 8 from flowing back upstream of the outflow pipeline 30. Here, the downstream backflow prevention valve 40 is installed in the portion of the outflow pipeline 30 downstream of the switching manhole 35. The public manhole 42 is installed in the portion of the outflow pipeline 30 downstream of the downstream backflow prevention valve 40. The downstream backflow prevention valve 40 is constructed using a conventionally known backflow prevention valve mechanism. Similarly, the public manhole 42 is constructed using a conventionally known public manhole mechanism. Therefore, a detailed explanation of the downstream backflow prevention valve 40 and the public manhole 42 is omitted.

Next, the manhole 50 will be described in detail. The manhole 50 is a switching manhole that switches the drainage flow path. In this embodiment, as shown in Figure 1, the manhole 50 is positioned between the first inlet pipe 10 and the outlet pipe 30, and between the second inlet pipe 20 and the outlet pipe 30. The manhole 50 is connected to the downstream end of the first inlet pipe 10, the downstream end of the second inlet pipe 20, and the upstream end of the outlet pipe 30.

Figure 5 is a front view of the manhole 50. Figures 6 and 7 are plan views of the manhole 50. Figure 8 is a cross-sectional view of the manhole 50 in the section VIII-VIII of Figure 6. Figure 9 is a cross-sectional view of the manhole 50 in the section IX-IX of Figure 7. Figure 10 is a cross-sectional view of the manhole 50 in the section X-X of Figure 7. As shown in Figure 6, the manhole 50 comprises a manhole body 51, a switching member 70, and a passage permission means 80.

As shown in Figure 8, the manhole body 51 is formed from a member having an internal space. The specific configuration of the manhole body 51 is not particularly limited. In this embodiment, the manhole body 51 includes a main body cylindrical section 52, an inspection cylindrical section 53, a first inlet cylindrical section 54, a second inlet cylindrical section 55, and an outlet cylindrical section 56 (see Figure 6). In the following description, the side of the manhole body 51 closer to the center C1 (see Figure 6) is referred to as the inside, and the side further away from the center C1 is referred to as the outside.

As shown in Figure 8, the main body cylindrical portion 52 is a bottomed cylindrical shape extending vertically. In this embodiment, the main body cylindrical portion 52 has a bottom wall portion 58 with a bottom surface 57 and side wall portions 59 that rise from the bottom wall portion 58. The bottom surface 57 constitutes the upper surface of the bottom wall portion 58 and is initially located inside the main body 51. The bottom surface 57 has a shape that is concave downwards toward the center C1 (see Figure 6). Here, the bottom surface 57 is a downwardly concave curved surface. The side wall portions 59 extend upwards and downwards from the ends of the bottom wall portion 58. The side wall portions 59 have a cylindrical shape.

In this embodiment, as shown in Figure 8, the cylindrical body portion 52 of the manhole body 51 has a first inlet 61, a second inlet 62, and an outlet 63 (see Figure 10). The first inlet 61 and the second inlet 62 are the parts through which water (in this case, drainage) flows into the manhole body 51, and as shown in Figure 10, the outlet 63 is the part through which water (in this case, drainage) flows out of the manhole body 51. Here, drainage from outside the manhole 60 flows into the manhole body 51 through the first inlet 61 or the second inlet 62. Drainage from inside the manhole body 51 flows out to the outside of the manhole 60 through the outlet 63.

The formation positions of the first inlet 61, second inlet 62, and outlet 63 relative to the main cylindrical portion 52 are not particularly limited. Here, as shown in Figure 8, the first inlet 61 and second inlet 62 are formed on the side of the main cylindrical portion 52. More specifically, the first inlet 61 and second inlet 62 are formed on the side wall portion 59 of the main cylindrical portion 52 and open laterally. As shown in Figure 6, the first inlet 61 and second inlet 62 face each other, and in a plan view, they face each other with the center C1 of the main body 51 in between. For example, in a plan view, the first inlet 61 and second inlet 62 are positioned such that the central axis L1 of the first inlet 61 coincides with the central axis L2 of the second inlet 62. That is, the angle between the central axes L1 and L2 is 180 degrees.

However, the first inlet 61 and the second inlet 62 do not necessarily have to face each other. The central axis L1 of the first inlet 61 and the central axis L2 of the second inlet 62 may not coincide in a plan view, but may intersect.

In this embodiment, the first inlet 61 and the second inlet 62 are the same size, have the same area, and have the same shape. However, the first inlet 61 and the second inlet 62 may be of different sizes. Here, the first inlet 61 and the second inlet 62 are circular (for example, perfectly circular), but the shape of the first inlet 61 and the second inlet 62 is not particularly limited. As shown in Figure 8, the first inlet 61 and the second inlet 62 are at the same height, but may be of different heights. Here, the first inlet 61 and the second inlet 62 are formed at positions spaced apart from the bottom surface 57. The bottom surface 57 is positioned below the lower end of the first inlet 61 and below the lower end of the second inlet 62.

In this embodiment, as shown in Figure 10, the outlet 63 is formed on the side of the main cylindrical portion 52. More specifically, the outlet 63 is formed in the side wall portion 59 of the main cylindrical portion 52 and opens laterally. Here, the outlet 63 is positioned lower than the first inlet 61 and the second inlet 62. The lower end of the outlet 63 is configured to be flush with a part of the bottom surface 57 of the bottom wall portion 58 of the main cylindrical portion 52 (in this case, the lowest part of the bottom surface 57). However, the outlet 63 may also be formed in the bottom wall portion 58 of the main cylindrical portion 52 and open downwards.

In this embodiment, the outlet 63 is the same size and area as the first inlet 61 and the second inlet 62. However, the outlet 63 may be smaller and have a smaller area than the first inlet 61 and the second inlet 62, or it may be larger and have a larger area than the first inlet 61 and the second inlet 62. The outlet 63 is circular (for example, a perfect circle), but its shape is not particularly limited. In this embodiment, as shown in Figure 6, the central axis L3 of the outlet 63 intersects the central axis L1 of the first inlet 61 and the central axis L2 of the second inlet 62 in a plan view. Here, the angles formed by the central axis L3 and the central axis L1, and the angles formed by the central axis L3 and the central axis L2 are 90 degrees, but these angles are not particularly limited.

As shown in Figure 8, the inspection tube section 53 is cylindrical and extends vertically above the main body tube section 52. The inspection tube section 53 is connected to one end (in this case, the upper end) of the main body tube section 52. More specifically, the inspection tube section 53 is connected to the upper end of the side wall section 59 of the main body tube section 52 and extends upward from the side wall section 59. An inspection opening 64 is formed in the inspection tube section 53, opening upwards. As shown in Figure 2, for example, a vertically extending riser 66 is connected to the inspection opening 64, and a lid 67 is attached to the riser 66. In this embodiment, as shown in Figure 8, the inspection tube section 53 is a single component with the main body tube section 52; however, it may be a separate component from the main body tube section 52 and assembled to it.

As shown in Figure 6, the first inlet pipe section 54 and the second inlet pipe section 55 each extend laterally. As shown in Figure 8, the first inlet pipe section 54 extends outward from the outer circumferential surface of the side wall section 59 of the main pipe section 52 and is connected to the first inlet 61. The first inlet pipeline 10 is connected to the first inlet pipe section 54. Here, the first inlet 61 is connected to the downstream end of the first inlet pipeline 10 via the first inlet pipe section 54. The second inlet pipe section 55 extends outward from the outer circumferential surface of the side wall section 59 of the main pipe section 52 and is connected to the second inlet 62. The second inlet pipeline 20 is connected to the second inlet pipe section 55. Here, the second inlet 62 is connected to the downstream end of the second inlet pipeline 20 via the second inlet pipe section 55. In this embodiment, as shown in Figure 6, the first inlet pipe 54 and the second inlet pipe 55 face each other in a plan view, with the center C1 of the manhole body 51 in between.

The outlet pipe section 56 extends laterally, extending outward from the outer circumferential surface of the side wall section 59. As shown in Figure 10, the outlet pipe section 56 is connected to the outlet 63. The outlet pipeline 30 is connected to the outlet pipe section 56. Here, the outlet 63 is connected to the upstream end of the outlet pipeline 30 via the outlet pipe section 56. As shown in Figure 5, the outlet pipe section 56 is positioned lower than the first inlet pipe section 54 and the second inlet pipe section 55.

In this embodiment, as shown in Figure 8, the first inlet pipe section 54 and the second inlet pipe section 55 are separate from the main pipe section 52 and are assembled to the main pipe section 52. However, the first inlet pipe section 54 and the second inlet pipe section 55 may be a single component with respect to the main pipe section 52. In this embodiment, as shown in Figure 10, the outlet pipe section 56 is a single component with respect to the main pipe section 52. However, the outlet pipe section 56 may be separate from the main pipe section 52 and be assembled to the main pipe section 52.

In this embodiment, as shown in Figure 6, the manhole body 51 has a first slide groove 66 and a second slide groove 67. The first slide groove 66 is provided on the inner circumferential surface of the main body cylindrical portion 52. As shown in Figure 10, the first slide groove 66 extends vertically. Here, a pair of first slide grooves 66 are provided so as to sandwich the first inlet 61. More specifically, as shown in Figure 7, a first inner circumferential surface portion 68 is provided on the inner circumferential surface of the main body cylindrical portion 52 around the first inlet 61. The first inner circumferential surface portion 68 has a cylindrical first fitting cylindrical portion 68a (see Figure 9) that is fitted into the first inlet 61, and a first flange surface portion 68b (see Figure 7) that extends outward from the end of the first fitting cylindrical portion 68a on the side of the center C1 of the manhole body 51. As shown in Figure 7, the first flange surface 68b has a curved shape that follows the inner circumferential surface of the main body cylindrical portion 52 (in this case, the inner circumferential surface of the side wall portion 59 (see Figure 8)). The first slide groove 66 is formed on the inner surfaces of both ends of the first flange surface 68b in a plan view.

As shown in Figure 6, the second slide groove 67 is provided on the inner circumferential surface of the main body cylindrical portion 52. As shown in Figure 8, the second slide groove 67 extends vertically, similar to the first slide groove 66. Here, as shown in Figure 6, a pair of second slide grooves 67 are provided so as to sandwich the second inlet 62. In this embodiment, a second inner circumferential surface portion 69 is provided on the inner circumferential surface of the main body cylindrical portion 52 around the second inlet 62. The second inner circumferential surface portion 69 has the same configuration as the first inner circumferential surface portion 68 described above. That is, the second inner circumferential surface portion 69 has a cylindrical second fitting cylindrical portion 69a (see Figure 8) that is fitted into the second inlet 62, and a second flange surface portion 69b (see Figure 6) that extends outward from the end of the second fitting cylindrical portion 69a on the side of the center C1 of the manhole body 51. As shown in Figure 6, the second flange surface portion 69b has a curved shape that follows the inner circumferential surface of the main body cylindrical portion 52. Second slide grooves 67 are formed on the inner surfaces of both ends of the second flange surface portion 69b in a plan view.

Next, the switching member 70 according to this embodiment will be described. The switching member 70 is a member that switches the drainage flow path within the manhole body 51. Here, the switching member 70 is a member for switching the main flow path when drainage flows into the manhole body 51. As shown in Figures 6 and 7, the switching member 70 is configured to be detachably attached to the inside of the manhole body 51. The switching member 70 can be positioned between a first switching position P1 and a second switching position P2 within the manhole body 51. Figures 6 and 8 show the state in which the switching member 70 is positioned at the first switching position P1. Figures 7 and 9 show the state in which the switching member 70 is positioned at the second switching position P2.

Here, the switching member 70 is configured to be selectively attached to the first inlet 61 and the second inlet 62. Attaching the switching member 70 to the first inlet 61 means positioning the switching member 70 so that the wastewater from the manhole body 51 does not flow back into the first inlet 61. Attaching the switching member 70 to the second inlet 62 means positioning the switching member 70 so that the wastewater from the manhole body 51 does not flow back into the second inlet 62.

As shown in Figure 8, the first switching position P1 is the position of the switching member 70 relative to the manhole body 51 when it is attached to the first inlet 61. When the switching member 70 is in the first switching position P1, the second inlet 62 is opened, and wastewater flows actively into the manhole body 51 from the second inlet 62. Also, when in the first switching position P1, as will be described in more detail later, the passage permission means 80 blocks the flow of wastewater from the manhole body 51 towards the first inlet 61, while allowing wastewater to flow into the manhole body 51 from the first inlet 61.

As shown in Figure 9, the second switching position P2 is the position of the switching member 70 relative to the manhole body 51 when it is attached to the second inlet 62. When the switching member 70 is in the second switching position P2, the first inlet 61 is opened, and wastewater flows actively into the manhole body 51 from the first inlet 61. Also, when in the second switching position P2, as will be described in more detail later, the passage permission means 80 blocks the wastewater flowing from the manhole body 51 towards the second inlet 62, while allowing wastewater to flow from the second inlet 62 into the manhole body 51.

Figures 11 and 12 are perspective views of the switching member 70. Figure 13 shows the switching member 70 as seen from the valve body 81 side. Figure 14 shows the switching member 70 as seen from the opposite side of the valve body 81. Figure 15 is a cross-sectional view of the switching member 70 at the XV-XV section in Figure 13.

In this embodiment, as shown in Figure 11, the switching member 70 has a switching body 71. The switching body 71 is cylindrical. As shown in Figure 12, a communication port 75 is formed in the switching body 71. As shown in Figure 8, when the switching member 70 is mounted on the main body cylindrical portion 52 of the manhole body 51, the communication port 75 opens to the side. The communication port 75 communicates with the first inlet 61 when the switching member 70 is positioned at the first switching position P1. Also, as shown in Figure 9, the communication port 75 communicates with the second inlet 62 when the switching member 70 is positioned at the second switching position P2.

In this embodiment, the switching member 70 can be positioned at a first switching position P1 or a second switching position P2 by sliding up and down relative to the manhole body 51. As shown in Figure 11, the switching member 70 has a sliding projection 72. The sliding projection 72 is used when the switching member 70 slides relative to the manhole body 51. The sliding projection 72 extends vertically. Here, as shown in Figure 6, the sliding projection 72 engages with a first sliding groove 66 of the manhole body 51 and is slidable relative to the first sliding groove 66. For example, when attempting to position the switching member 70 at the first switching position P1, the sliding projection 72 slides relative to the first sliding groove 66, thereby attaching the switching member 70 to the first inlet 61 and positioning it at the first switching position P1. As shown in Figure 7, the sliding projection 72 engages with a second sliding groove 67 of the manhole body 51 and is slidable relative to the second sliding groove 67. When attempting to position the switching member 70 at the second switching position P2, the sliding projection 72 slides relative to the second sliding groove 67, thereby attaching the switching member 70 to the second inlet 62 and positioning it at the second switching position P2.

The number of slide protrusions 72 is not particularly limited, but here it is two, the same as the number of first slide grooves 66 or the number of second slide grooves 67. The slide protrusions 72 are provided in pairs so as to sandwich the switching body 71. In this embodiment, the switching member 70 has a slide surface portion 73. The slide surface portion 73 slides along the inner circumferential surface of the main body cylindrical portion 52 of the main body 51 when the switching member 70 slides up and down relative to the main body 51. Here, as shown in Figure 6, when attempting to position the switching member 70 at the first switching position P1, the slide surface portion 73 slides while contacting the first flange surface portion 68b of the first inner circumferential surface portion 68 where the first slide groove 66 is formed. As shown in Figure 7, when attempting to position the switching member 70 at the second switching position P2, the slide surface portion 73 slides while contacting the second flange surface portion 69b of the second inner circumferential surface portion 69 where the second slide groove 67 is formed.

The sliding surface portion 73 is provided at the inner circumferential end of the main body cylindrical portion 52 of the cylindrical switching body 71, and extends outward from the outer circumferential surface of the switching body 71. The sliding surface portion 73 has a curved shape corresponding to the inner circumferential surface of the main body cylindrical portion 52 (in other words, the first flange surface portion 68b of the first inner circumferential surface portion 68, and the second flange surface portion 69b of the second inner circumferential surface portion 69). In this embodiment, the sliding projection 72 is provided on the inner circumferential surface of the main body cylindrical portion 52 at both ends of the sliding surface portion 73 in a plan view (here, both ends in the horizontal direction).

In this embodiment, as shown in Figure 14, the switching member 70 has a sealing member 76. As shown in Figure 8, the sealing member 76 prevents wastewater from leaking between the manhole body 51 and the switching member 70. The sealing member 76 is positioned between the inner circumferential surface of the main cylindrical portion 52 of the manhole body 51 and the switching member 70 (for example, the switching body 71). Here, as shown in Figure 14, the sealing member 76 is provided on the inner circumferential surface side of the main cylindrical portion 52 on the sliding surface portion 73, surrounding the communication opening 75. However, the sealing member 76 may also be provided on the inner circumferential surface of the main cylindrical portion 52 of the manhole body 51. The sealing member 76 is annular. The material forming the sealing member 76 is not particularly limited, but for example, the sealing member 76 is formed of an elastic material, such as rubber.

In this embodiment, the switching member 70 has a handle 77. The handle 77 is grasped by the operator's hand. By grasping the handle 77 and moving the switching member 70, the operator can position the switching member 70 at the first switching position P1 or the second switching position P2. Here, the handle 77 is provided at the upper end of the sliding surface 73 and extends upward from the sliding surface 73. The shape of the handle 77 is not particularly limited, but here it is formed in a U-shape that is convex upwards.

Next, the passage permitting means 80 according to this embodiment will be described. As shown in Figure 11, the passage permitting means 80 is provided on the switching member 70. As shown in Figures 8 and 9, the passage permitting means 80 allows wastewater flowing in one direction to pass through, and blocks wastewater flowing in the opposite direction. In this embodiment, one direction refers to the direction from the first inlet 61 or the second inlet 62 towards the manhole body 51. The other direction refers to the direction from inside the manhole body 51 towards the first inlet 61 or the second inlet 62. Here, the passage permitting means 80 blocks wastewater flowing from inside the manhole body 51 towards the first inlet 61 or the second inlet 62, depending on the position of the switching member 70.

Figures 16 and 17 are corresponding diagrams to Figure 8 and Figure 9, respectively, showing the state in which the valve body 81 of the passage permitting means 80 is opening the communication port 75. In this embodiment, as shown in Figure 8, the passage permitting means 80 is configured to block drainage from inside the manhole body 51 toward the first inlet 61 when the switching member 70 is in the first switching position P1, and to allow drainage to flow from the first inlet 61 into the manhole body 51, as shown in Figure 16. Furthermore, as shown in Figure 9, the passage permitting means 80 is configured to block drainage from inside the manhole body 51 toward the second inlet 62 when the switching member 70 is in the second switching position P2, and to allow drainage to flow from the second inlet 62 into the manhole body 51, as shown in Figure 17.

Figure 18 shows the side of the valve body 81 of the passage permitting means 80 facing the switching body 71. In this embodiment, as shown in Figure 11, the passage permitting means 80 has a valve body 81, a rotating shaft 82, and a backflow prevention sealing member 83 (see Figure 18). As shown in Figures 11 and 12, the valve body 81 is configured to open and close the communication port 75 of the switching member 70. As shown in Figure 6, the valve body 81 can open and close the communication port 75 from the outside of the switching member 70 (here, the side facing the center C1 of the manhole body 51) and can contact the switching body 71 (more specifically, the end portion 71a of the switching body 71 on the side facing the center C1 of the manhole body 51). The valve body 81 has a larger shape than the communication port 75. Therefore, when the valve body 81 contacts the end portion 71a of the switching body 71, the communication port 75 is closed. In this embodiment, the valve body 81 is configured to close the communication port 75 when no drainage is flowing into the drainage piping system 1.

As shown in Figure 15, the valve body 81 has a recess 85. The recess 85 is formed in the valve body 81 and is recessed towards the communication port 75. The shape of the recess 85 is not particularly limited, but here it is a frustoconical shape. In the frustoconical recess 85, of the two opposing planes, the smaller plane is eccentrically positioned downwards relative to the larger plane.

In this embodiment, as shown in Figures 11 and 12, the valve body 81 can open and close the communication port 75 by rotating relative to the switching member 70. Here, the valve body 81 is configured to rotate around a rotation axis 82. The rotation axis 82 is provided on the portion of the switching body 71 located around the communication port 75. Specifically, the rotation axis 82 is provided at the end 71a of the switching body 71, more precisely at the upper part of the end 71a, above the communication port 75. As shown in Figure 13, the rotation axis 82 extends horizontally. The rotation axis 82 is connected to the upper end of the valve body 81. Therefore, as shown in Figure 12, the valve body 81 rotates around its upper end as an axis. Here, the valve body 81 opens the communication port 75 by rotating upward.

As shown in Figure 15, the backflow prevention sealing member 83 prevents wastewater leakage from between the switching member 70 (specifically the switching body 71) and the valve body 81 when the valve body 81 is closing the communication port 75 of the switching member 70. The backflow prevention sealing member 83 is positioned between the switching body 71 (here, the end portion 71a of the switching body 71) located around the communication port 75 and the valve body 81. Here, the backflow prevention sealing member 83 is provided on the surface of the valve body 81 facing the switching member 70, surrounding the communication port 75 when the valve body 81 is closing it. However, the backflow prevention sealing member 83 may also be provided on the switching body 71. As shown in Figure 18, the backflow prevention sealing member 83 is annular. The material forming the backflow prevention sealing member 83 is not particularly limited. Here, the backflow prevention sealing member 83, like the sealing member 76, is formed from an elastic material, such as rubber.

In this embodiment, as shown in Figure 15, a flange 86 is provided on the side of the valve body 81 facing the switching member 70, projecting toward the switching member 70. The flange 86 is cylindrical and is inserted into the communication port 75 when the valve body 81 is closing the port. Therefore, the outer diameter of the cylindrical flange 86 is slightly smaller than the diameter of the communication port 75. As shown in Figure 18, the backflow prevention seal member 83 is positioned to surround the flange 86 from the outside.

In this embodiment, the material forming the manhole 50 is not particularly limited. Here, the material forming the manhole 50 refers to the material for the components constituting the manhole body 51, the switching member 70, and the passage permitting means 80, and refers to the material forming components other than those formed from elastic materials (e.g., rubber) as described above (e.g., the sealing member 76, the backflow prevention sealing member 83, etc.). In this embodiment, the material forming the manhole 50 is a resin material. Examples of resin materials include polyvinyl chloride resin or polypropylene resin. Among polyvinyl chloride resins, rigid polyvinyl chloride resin can be suitably used as the material forming the manhole 50.

The configuration of the drainage piping system 1 according to this embodiment has been described above. Next, the method of using the drainage piping system 1 will be described. The method of using the drainage piping system 1 differs between normal use and during disasters such as earthquakes. Under normal circumstances, as shown in Figure 1, the drainage piping system 1 is configured to primarily drain wastewater discharged from the drainage equipment 6 into the main sewer pipe 8. During a disaster, the drainage piping system 1 is configured to selectively drain wastewater containing excrement discharged from the temporary toilet 4 (see Figure 3) into the main sewer pipe 8 or the storage tank 32.

First, let's explain how the drainage piping system 1 is used under normal conditions. Under normal conditions, the drainage equipment 6 is used, and the water supply tank 26 is generally not used. That is, under normal conditions, the first inflow pipeline 10 is mainly used, and the second inflow pipeline 20 is generally not used. Therefore, under normal conditions, as shown in Figure 7, the switching member 70 is attached to the second inlet 62 in the manhole 50 and positioned at the second switching position P2. As a result, as shown in Figure 9, the communication port 75 of the switching member 70 is closed by the valve body 81 of the passage permitting means 80, thus closing the second inlet 62.

Under normal conditions, the second switching outlet 37b (see Figure 4) of the switching manhole 35 (see Figure 4), located in the middle of the outflow pipeline 30, is closed by a switching closing member. Therefore, under normal conditions, wastewater is not discharged into the storage tank 32 connected to the second switching outlet 37b. Furthermore, under normal conditions, as shown in Figure 2, the temporary toilet 4 is not attached to the mounting opening 24 of the toilet connection manhole 22, and a cover 25 is attached to the mounting opening 24.

As shown in Figure 1, under normal circumstances, wastewater discharged from the drainage facility 6 is discharged to the first inflow pipeline 10 through the branch pipeline 14. As shown in Figure 7, the wastewater discharged to the first inflow pipeline 10 flows into the manhole body 51 from the first inlet 61 of the manhole 50. In the manhole 50, a switching member 70 is attached to the second inlet 62, and the wastewater in the manhole body 51 presses the valve body 81 of the passage permitting means 80 against the communication port 75 of the switching member 70. Therefore, as shown in Figure 9, the second inlet 62 is closed by the valve body 81, and the wastewater in the manhole body 51 does not flow into the second inlet 62 but flows to the outlet 63 and out into the outflow pipeline 30 shown in Figure 1. After that, as shown in Figure 4, the wastewater flows from the switching inlet 36 towards the first switching outlet 37a in the switching manhole 35. At the switching manhole 35, wastewater discharged from the first switching outlet 37a is discharged into the main sewer pipe 8 through the public manhole 42.

In this embodiment, the second inlet pipe 20 is not normally used, but water (for example, water stored in the water supply tank 26) may be flowed through the second inlet pipe 20 when inspecting or cleaning it. In this embodiment, under normal circumstances, as shown in Figure 7, the switching member 70 is positioned at the second switching position P2 in the basin 50 and attached to the second inlet 62. In this state, when water flows through the second inlet pipe 20, the water flow velocity pushes the valve body 81 that closes the communication port 75 of the switching member 70, as shown in Figure 17. At this time, the valve body 81 rotates upward around the rotation axis 82, opening the communication port 75. As a result, the water in the second inlet pipe 20 flows through the second inlet 62 and the open communication port 75 to the manhole body 51, and is discharged to the main sewer pipe 8 (see Figure 1) through the outlet 63 and the outlet pipe 30. Thus, in this embodiment, even when water flows through the second inlet pipe 20 under normal conditions, the water is less likely to remain in the second inlet pipe 20 and can flow towards the main sewer pipe 8.

Next, the method of using the drainage piping system 1 during a disaster will be explained. During a disaster, a temporary toilet 4 (see Figure 3) will be used. Therefore, as shown in Figure 3, the cover 25 (see Figure 2) will be removed from the mounting opening 24 of the toilet connection manhole 22, and the toilet bowl 4a of the temporary toilet 4 will be attached to the mounting opening 24. During a disaster, the water in the water supply tank 26 will be used as needed, and when the water in the water supply tank 26 flows into the second inflow pipeline 20, the water supply opening/closing gate 28 will open the upstream end of the second inflow pipeline 20.

During a disaster, the second inflow pipeline 20 is primarily used, while the first inflow pipeline 10 is used only as needed. Here, during a disaster, as shown in Figure 6, the switching member 70 is attached to the first inlet 61 in the manhole 50 and positioned at the first switching position P1. As a result, as shown in Figure 8, the communication port 75 of the switching member 70 is closed by the valve body 81 of the passage permitting means 80, thereby closing the first inlet 61.

As shown in Figure 3, when the temporary toilet 4 is installed during a disaster, the upstream end of the second inflow pipeline 20 is closed by the water supply gate 28. Therefore, wastewater discharged from the temporary toilet 4 is discharged into the second inflow pipeline 20, and at least a portion of the discharged wastewater, such as feces and other excrement contained in the wastewater, remains within the second inflow pipeline 20.

When discharging wastewater remaining in the second inlet pipe 20 to the outlet pipe 30, the upstream end of the second inlet pipe 20 is opened by the water supply gate 28, allowing water to flow from the water supply tank 26 into the second inlet pipe 20. As a result, the wastewater accumulated in the second inlet pipe 20 flows, along with the water from the water supply tank 26, into the manhole body 51 through the second inlet 62 of the manhole 50, as shown in Figure 6. Here, in the manhole 50, a switching member 70 is attached to the first inlet 61, causing the wastewater in the manhole body 51 to press the valve body 81 of the passage permitting means 80 against the communication port 75 of the switching member 70. Therefore, as shown in Figure 8, the first inlet 61 is closed by the valve body 81, and the wastewater in the manhole body 51 does not flow into the first inlet 61, but instead flows to the outlet 63 and out into the outlet pipe 30.

As shown in Figure 1, in the event of a disaster, wastewater flowing into the outflow pipeline 30 may be discharged into the main sewer line 8 or into the storage tank 32. For example, if the main sewer line 8 is not damaged during a disaster, the wastewater discharged from the temporary toilet 4 will be discharged into the main sewer line 8. In this case, the second switching outlet 37b (see Figure 4) of the switching manhole 35, which is located in the middle of the outflow pipeline 30, is closed by a switching closing member. Therefore, the wastewater discharged from the temporary toilet 4 is discharged into the main sewer line 8 through the first switching outlet 37a of the switching manhole 35.

On the other hand, if the main sewer pipe 8 is damaged during a disaster, the wastewater discharged from the temporary toilet 4 is discharged into the storage tank 32. At this time, in the switching manhole 35 located in the middle of the outflow pipeline 30, the switching closing member is removed from the second switching outlet 37b, opening the second switching outlet 37b. As a result, the wastewater discharged from the temporary toilet 4 is discharged into the storage tank 32 through the second switching outlet 37b of the switching manhole 35.

In this embodiment, the first inflow pipeline 10 can be used during a disaster. That is, the drainage facility 6 can be used during a disaster, and the wastewater discharged from the drainage facility 6 can be flowed into the outflow pipeline 30. In this embodiment, during a disaster, as shown in Figure 8, the switching member 70 is positioned at the first switching position P1 in the manhole 50 and attached to the first inlet 61. In this state, when wastewater is discharged from the drainage facility 6 into the first inflow pipeline 10, the flow velocity of the wastewater pushes the valve body 81 that is closing the communication port 75 of the switching member 70 attached to the first inlet 61. At this time, as shown in Figure 16, the valve body 81 rotates upward around the rotation axis 82, thereby opening the communication port 75. As a result, the wastewater in the first inflow pipeline 10 flows into the manhole body 51 through the first inlet 61 and the opened communication port 75. Subsequently, the wastewater flows through the outlet 63 into the outflow pipeline 30 and is discharged into the main sewer pipe 8 or the storage tank 32. Thus, in this embodiment, the drainage system 6 can be used during a disaster.

In this embodiment, as shown in Figure 6, the manhole 50 comprises a manhole body 51, a switching member 70, and a passage permission means 80. As shown in Figures 8 and 10, the manhole body 51 has a bottomed cylindrical body section 52 in which a first inlet 61, a second inlet 62, and an outlet 63 are formed, and an inspection section 53 connected to one end (here, the upper end) of the body section 52, in which an inspection opening 64 is formed. The switching member 70 is detachably attached to the inside of the body section 52. As shown in Figure 8, the switching member 70 can be repositioned to a first switching position P1 in which it is attached to the first inlet 61 while the second inlet 62 is open, and as shown in Figure 9, to a second switching position P2 in which it is attached to the second inlet 62 while the first inlet 61 is open. The passage permission means 80 is provided on the switching member 70. As shown in Figure 16, the passage permitting means 80 is configured to allow water (in this case, drainage) to flow from the first inlet 61 into the manhole body 51 when the switching member 70 is positioned at the first switching position P1, and to block drainage from the manhole body 51 toward the first inlet 61, as shown in Figure 8. Furthermore, as shown in Figure 17, the passage permitting means 80 is configured to allow water (in this case, drainage) to flow from the second inlet 62 into the manhole body 51 when the switching member 70 is positioned at the second switching position P2, and to block drainage from the manhole body 51 toward the second inlet 62, as shown in Figure 9.

As a result, as shown in Figure 8, when the switching member 70 is positioned at the first switching position P1 and attached to the first inlet 61, wastewater can be flowed from the second inlet 62 to the outlet 63. At this time, the passage permitting means 80 prevents wastewater in the manhole body 51 from flowing back into the first inlet 61, while allowing wastewater to flow into the manhole body 51 from the first inlet 61, as shown in Figure 16. Also, as shown in Figure 9, when the switching member 70 is positioned at the second switching position P2 and attached to the second inlet 62, wastewater can be flowed from the first inlet 61 to the outlet 63. At this time, the passage permitting means 80 prevents wastewater in the manhole body 51 from flowing back into the second inlet 62, while allowing water to flow into the manhole body 51 from the second inlet 62, as shown in Figure 17. In this way, by providing the passage permission means 80 on the switching member 70, it is possible for wastewater to flow into the manhole body 51 from the inlets 61 and 62 to which the switching member 70 is attached, while preventing wastewater from flowing back into the inlets 61 and 62 to which the switching member 70 is attached.

As shown in Figure 1, the drainage piping system 1 according to this embodiment comprises a manhole 50, a first inlet pipe 10, a water supply tank 26 (an example of a water storage means), a second inlet pipe 20, and an outlet pipe 30. The first inlet pipe 10 is connected to a drainage facility 6 for discharging wastewater and to the first inlet 61 of the manhole 50. The second inlet pipe 20 is connected to the water supply tank 26 and to the second inlet 62 of the manhole 50. The outlet pipe 30 is connected to the outlet 63 of the manhole 50. Here, as shown in Figure 3, a temporary toilet 4 is configured to be attachable to the second inlet pipe 20.

Therefore, under normal circumstances, when draining wastewater from the drainage facility 6 into the outflow pipeline 30, the switching member 70 of the manhole 50 is positioned at the second switching position P2 and attached to the second inlet 62, as shown in Figure 9. This opens the first inlet 61, allowing wastewater from the drainage facility 6 to be discharged from the first inflow pipeline 10 through the first inlet 61 into the outflow pipeline 30. Here, the switching member 70 is provided with a passage permission means 80. Therefore, when the switching member 70 is positioned at the second switching position P2, the passage permission means 80 prevents wastewater flowing from the first inlet 61 into the manhole body 51 from flowing back into the second inlet 62. Furthermore, when water flows through the second inflow pipeline 20, for example, to clean the second inflow pipeline 20, the water flowing through the second inflow pipeline 20 can be allowed to flow into the manhole body 51 from the second inlet 62, as shown in Figure 17.

Furthermore, in the event of a disaster, if the temporary toilet 4 is installed in the second inflow pipeline 20 as shown in Figure 3, the switching member 70 of the manhole 50 is positioned at the first switching position P1 and attached to the first inlet 61, as shown in Figure 8. This opens the second inlet 62, allowing the wastewater discharged from the temporary toilet 4, along with the water stored in the water supply tank 26, to be discharged into the outflow pipeline 30. Here, since the switching member 70 is equipped with a passage permission means 80, when the switching member 70 is positioned at the first switching position P1, the passage permission means 80 prevents the wastewater discharged from the temporary toilet 4 from flowing back into the first inlet 61. Moreover, as shown in Figure 16, even when the switching member 70 is positioned at the first switching position P1, the wastewater discharged from the drainage facility 6 can flow from the first inflow pipeline 10 through the first inlet 61 into the manhole body 51.

In this embodiment, as shown in Figures 8 and 9, the switching member 70 has a switching body 71 with a communication port 75 formed therein that communicates with the first inlet 61 when at the first switching position P1 and with the second inlet 62 when at the second switching position P2. The passage permitting means 80 has a valve body 81 that can open and close the communication port 75 from the outside of the switching member 70 and can abut against the switching body 71. As a result, as shown in Figure 8, when at the first switching position P1, the valve body 81 closes the communication port 75 that communicates with the first inlet 61, thereby preventing wastewater from flowing back from the manhole body 51 to the first inlet 61. As shown in Figure 16, when at the first switching position P1, the valve body 81 opens the communication port 75, allowing wastewater to flow from the first inlet 61 into the manhole body 51. Similarly, as shown in Figure 9, when the valve is in the second switching position P2, the valve body 81 closes the communication port 75 that communicates with the second inlet 62, preventing wastewater from flowing back from the manhole body 51 to the second inlet 62. As shown in Figure 17, when the valve is in the second switching position P2, the valve body 81 opens the communication port 75, allowing wastewater to flow from the second inlet 62 into the manhole body 51.

In this embodiment, as shown in Figure 12, the passage permission means 80 has a rotating shaft 82 provided on the portion of the switching body 71 located around the communication opening 75. The valve body 81 is mounted on the rotating shaft 82 and is configured to rotate around the rotating shaft 82. This allows the valve body 81 to easily open and close the communication opening 75 with a simple configuration of rotation around the rotating shaft 82.

In this embodiment, as shown in Figure 15, the valve body 81 has a recess 85 that is recessed toward the communication opening 75. This allows the valve body 81 to be pressed toward the communication opening 75 by the flow of drainage within the manhole body 51, thereby closing the communication opening 75. Here, the recess 85 in the valve body 81 increases the contact area between the valve body 81 and the drainage within the manhole body 51. Therefore, the valve body 81 is easily pressed toward the communication opening 75 by the flow of water within the manhole body 51, allowing the valve body 81 to easily close the communication opening 75.

In this embodiment, as shown in Figure 15, the passage permitting means 80 has a backflow prevention sealing member 83 positioned between the switching body 71 and the valve body 81 when the valve body 81 is closing the communication port 75. Such a backflow prevention sealing member 83 can prevent wastewater from leaking from between the switching body 71 and the valve body 81.

In this embodiment, as shown in Figure 8, the switching member 70 has a sealing member 76 positioned between the inner circumferential surface of the main body cylindrical portion 52 of the manhole body 51 and the switching body 71. This sealing member 76 prevents wastewater from leaking from between the inner circumferential surface of the main body cylindrical portion 52 and the switching body 71.

In this embodiment, the manhole body 51, as shown in Figure 9, has a first slide groove 66 extending vertically on the inner circumferential surface of the main body cylindrical portion 52, and a second slide groove 67 extending vertically, as shown in Figure 8. As shown in Figure 6, the switching member 70 has a slide projection 72 that is slidable relative to the first slide groove 66 when positioned at the first switching position P1, and slideable relative to the second slide groove 67 when positioned at the second switching position P2, as shown in Figure 7. Therefore, as shown in Figure 6, by sliding the slide projection 72 relative to the first slide groove 66, the switching member 70 can be slid vertically relative to the manhole body 51 to position the switching member 70 at the first switching position P1. Furthermore, as shown in Figure 7, by sliding the slide projection 72 relative to the second slide groove 67, the switching member 70 can be slid vertically relative to the manhole body 51 to position the switching member 70 at the second switching position P2.

In this embodiment, the switching member 70 has a sliding surface portion 73 that is shaped to conform to the inner circumferential surface of the cylindrical portion 52 of the manhole body 51. This makes it easier to move the sliding surface portion 73 along the inner circumferential surface of the cylindrical portion 52 when sliding the switching member 70 up and down relative to the manhole body 51. Therefore, since the switching member 70 can be slid up and down while being guided by the sliding surface portion 73, the switching member 70 can be easily slid.

In this embodiment, as shown in Figure 8, the first inlet 61 and the second inlet 62 are formed on the side of the main body cylindrical portion 52. The manhole body 51 has a bottom surface 57 positioned below the lower end of the first inlet 61 and below the lower end of the second inlet 62. As a result, when the switching member 70 is positioned at the first switching position P1, the wastewater flowing into the manhole body 51 from the second inlet 62 falls onto the bottom surface 57 of the manhole body 51. Since the bottom surface 57 of the manhole body 51 is positioned below the lower end of the first inlet 61, it is possible to make it difficult for the wastewater on the bottom surface 57 to flow back into the first inlet 61. Also, as shown in Figure 9, when the switching member 70 is positioned at the second switching position P2, the wastewater flowing into the manhole body 51 from the first inlet 61 falls onto the bottom surface 57 of the manhole body 51. Since the bottom surface 57 of the main body 51 is spaced lower than the lower end of the second inlet 62, it is possible to prevent drainage from the bottom surface 57 from flowing back into the second inlet 62.

<Other Embodiments>
In the above embodiment, the temporary toilet 4 could be attached to the second inflow pipeline 20 to which the water supply tank 26 was connected. However, as shown in the drainage piping system 1A in Figures 19 and 20, the temporary toilet 4 may also be attached to the outflow pipeline 30.

In this case, the toilet connection manhole 22 is preferably installed in the middle of the outflow pipeline 30 upstream of the switching manhole 35. Then, in the event of a disaster, the toilet bowl 4a of the temporary toilet 4 is preferably attached to the mounting port 24 of the toilet connection manhole 22 installed in the middle of the outflow pipeline 30. In this embodiment, in the event of a disaster, the wastewater discharged from the temporary toilet 4 is discharged into the outflow pipeline 30, and at least a portion of the wastewater accumulates in the outflow pipeline 30. When the wastewater accumulated in the outflow pipeline 30 is to be discharged downstream, as shown in Figure 3, the upstream end of the second inflow pipeline 20 is opened by the water supply gate 28, and water from the water supply tank 26 is discharged from the second inflow pipeline 20 through the manhole 50 into the outflow pipeline 30. This allows the wastewater accumulated in the outflow pipeline 30 to be discharged into the main sewer line 8 or the storage tank 32 together with the water flowing from the water supply tank 26.

Furthermore, the temporary toilet 4 can be installed in both the second inflow pipe 20 and the outflow pipe 30. In this case, the toilet connection manhole 22 should preferably be installed in the middle of the second inflow pipe 20 and in the middle of the outflow pipe 30 upstream of the switching manhole 35. Additionally, the temporary toilet 4 can also be installed in the inspection port 64 of the manhole 50.

Figure 21 is a schematic plan view showing a drainage piping system 1B according to another embodiment. Figure 22 is a schematic plan view showing a manhole 50B according to another embodiment. Note that in Figure 22, only the outer casing of the manhole 50B is shown; the internal structure of the manhole 50B is not illustrated.

As shown in Figure 21, in the drainage piping system 1B, a toilet connection manhole 22 is provided in the middle of the second inflow pipe 20 to which the water storage tank 26 is connected, and a temporary toilet 4 (see Figure 3) can be attached to the second inflow pipe 20. The drainage piping system 1B is equipped with a manhole 50B. In this embodiment, the first inflow pipe 10 and the second inflow pipe 20 are arranged on one side of the manhole 50B (here, the left side of the manhole 50B in Figure 21), and the outflow pipe 30 is arranged on the other side of the manhole 50B (here, the right side of the manhole 50B in Figure 21).

As shown in Figure 22, in the manhole 50B, the line passing through the center C1 of the manhole body 51 in a plan view is defined as the dividing line L10. In Figure 22, the area to the left of the dividing line L10 of the manhole body 51 is considered one side, and the area to the right of the dividing line L10 of the manhole body 51 is considered the other side. In this embodiment of the manhole 50B, the first inlet 61 and the second inlet 62 are formed in the cylindrical portion 52 located on one side of the manhole body 51. The outlet 63 is formed in the cylindrical portion 52 located on the other side of the manhole body 51.

In a plan view, the angle R1 formed by the central axis L1 of the first inlet 61 and the central axis L3 of the outlet 63 is obtuse, greater than 90 degrees and less than or equal to 180 degrees. Similarly, in a plan view, the angle R2 formed by the central axis L2 of the second inlet 62 and the central axis L3 of the outlet 63 is obtuse, greater than 90 degrees and less than or equal to 180 degrees. In this embodiment, angles R1 and R2 are different. Here, angle R1 may be greater than but less than angle R2. Also, angles R1 and R2 may be the same.

In this embodiment, in a plan view, the angle R1 formed by the central axis L1 of the first inlet 61 and the central axis L3 of the outlet 63 is obtuse. Therefore, the wastewater discharged from the drainage facility 6 flows vigorously into the manhole body 51 from the first inlet 61 of the manhole 50B. Within the manhole body 51, the wastewater flowing in from the first inlet 61 flows easily toward the outlet 63, allowing it to be discharged into the outflow pipeline 30 through the outlet 63 while maintaining its momentum.

Similarly, in a plan view, the angle R2 formed by the central axis L2 of the second inlet 62 and the central axis L3 of the outlet 63 is obtuse. Therefore, the wastewater discharged from the temporary toilet 4 flows forcefully into the manhole body 51 from the second inlet 62 of the manhole 50B. Within the manhole body 51, the wastewater flowing in from the second inlet 62 flows easily towards the outlet 63, maintaining its momentum as it is discharged into the outflow pipeline 30 through the outlet 63. The wastewater discharged from the temporary toilet 4 contains feces and other waste. Here, because the wastewater flows easily into the outflow pipeline 30 while maintaining its momentum, the waste contained in the wastewater is less likely to remain in the manhole body 51 or the outflow pipeline 30.

In the above embodiments, the switching member 70 was provided in the manholes 50 and 50B and was intended to be sold as a set with the manhole body 51, etc. However, the switching member 70 can be sold separately. In this case, the switching member 70 is a switching member 70 for manhole 50, which is detachably attached to the inside of the main cylindrical portion 52 of the manhole body 51 in manholes 50 and 50B, which have a manhole body 51 having a bottomed cylindrical main cylindrical portion 52 in which a first inlet 61, a second inlet 62 and an outlet 63 are formed, and an inspection cylindrical portion 53 connected to one end of the main cylindrical portion 52 and in which an inspection port 64 is formed. The switching member 70 is configured to be able to change position between a first switching position P1 in which it is attached to the first inlet 61 while the second inlet 62 is open, and a second switching position P2 in which it is attached to the second inlet 62 while the first inlet 61 is open. In this case, the switching member 70 is equipped with a passage permitting means 80 that allows water flowing in one direction (in this case, drainage) to pass through, and blocks water flowing in the opposite direction. The passage permitting means 80 is configured such that when the switching member 70 is positioned at the first switching position P1, water can flow from the first inlet 61 into the manhole body 51, and water flowing from the manhole body 51 towards the first inlet 61 is blocked. Furthermore, when the switching member 70 is positioned at the second switching position P2, the passage permitting means 80 is configured to allow water to flow from the second inlet 62 into the manhole body 51, and water flowing from the manhole body 51 towards the second inlet 62 is blocked. Thus, even when the switching member 70 is sold as a standalone unit, the same effects as in the above embodiments can be obtained.

In each of the above embodiments, when no drainage is flowing through the drainage piping systems 1 and 1A, the communication port 75 of the switching member 70 of the manhole 50 is closed by the valve body 81. However, when no drainage is flowing through the drainage piping systems 1 and 1A, the communication port 75 of the switching member 70 of the manhole 50 may be open by the valve body 81. In this case, for example, the manhole 50 may be positioned so that the communication port 75 of the switching member 70 opens diagonally downward, and the valve body 81 may be configured to open and close the communication port 75 from diagonally downward. In this case, the valve body 81 will be in an upright position due to its own weight, and the communication port 75 will be open.

In the embodiments described above, the manhole 50 was installed in the drainage piping systems 1 and 1A through which wastewater flows. However, the manhole 50 may be installed in a piping system through which rainwater flows, and rainwater may flow through the manhole body 51 of the manhole 50. Furthermore, the manhole 50 may be installed in a piping system through which relatively clean water flows, rather than wastewater, and relatively clean water may flow through the manhole body 51 of the manhole 50.

1. 1A Drainage piping system 4 Temporary toilet 6 Drainage equipment 10 First inflow pipeline 20 Second inflow pipeline 26 Water supply tank (water storage means)
30 Outlet pipeline 50 Manhole 51 Manhole body 52 Main body cylindrical section 53 Inspection cylindrical section 57 Bottom surface 61 First inlet 62 Second inlet 63 Outlet 64 Inspection port 66 First slide groove 67 Second slide groove 70 Switching member 71 Switching body 72 Slide projection 73 Slide surface 75 Communication port 76 Seal member 80 Passage permitting means 81 Valve body 82 Rotating shaft 83 Backflow prevention seal member 85 Recess P1 First switching position P2 Second switching position

Claims (6)

The main body comprises a bottomed cylindrical body section having a first inlet, a second inlet, and an outlet, and an inspection cylinder section connected to one end of the main body section, having an inspection port.
A switching member is detachably attached to the inside of the main body cylinder and is capable of being repositioned between a first switching position, which is attached to the first inlet while the second inlet is open, and a second switching position, which is attached to the second inlet while the first inlet is open.
The switching member is provided with a passage permitting means that allows water flowing in one direction to pass through and blocks water flowing in the opposite direction,
Equipped with,
The aforementioned means of granting passage is,
When the switching member is positioned in the first switching position, it is possible to allow water to flow from the first inlet into the manhole body, and it is configured to block water flowing from the manhole body toward the first inlet.
The manhole is configured such that when the switching member is positioned in the second switching position, water can flow from the second inlet into the manhole body, and water flowing from the manhole body toward the second inlet is blocked. The switching member has a switching body having a communication port formed therein that communicates with the first inlet when in the first switching position and with the second inlet when in the second switching position.
The passage permitting means is capable of opening and closing the communication port from the center side of the manhole body and has a valve body that can contact the switching body, as described in claim 1. The first inlet and the second inlet are formed on the side of the main body cylindrical portion,
The manhole body according to claim 1 has a bottom surface positioned at a distance below the lower end of the first inlet and the lower end of the second inlet. In a plan view, the angle formed by the central axis of the first inlet and the central axis of the outlet, and the angle formed by the central axis of the second inlet and the central axis of the outlet, are obtuse angles, as described in claim 1. As described in any one of claims 1 to 4,
A drainage facility for discharging wastewater, and a first inlet pipeline connected to the first inlet of the manhole,
A water storage means in which water is stored,
The water storage means and the second inflow pipe connected to the second inlet of the manhole,
An outflow pipeline connected to the outlet of the aforementioned manhole,
Equipped with,
A drainage piping system configured such that a temporary toilet can be attached to the second inlet pipe or the outlet pipe. A manhole comprising a manhole body having a bottomed cylindrical main body section formed with a first inlet, a second inlet, and an outlet, and an inspection cylinder section connected to one end of the main body section and having an inspection opening, wherein a manhole switching member is detachably attached to the inside of the main body section of the manhole body,
It is configured to be able to change position between a first switching position, which is attached to the first inlet while the second inlet is open, and a second switching position, which is attached to the second inlet while the first inlet is open.
It is equipped with a passage-permitting means that allows water flowing in one direction to pass through, and blocks water flowing in the opposite direction to the aforementioned one direction,
The aforementioned means of granting passage is,
When the switching member is positioned in the first switching position, it is possible to allow water to flow from the first inlet into the manhole body, and it is configured to block water flowing from the manhole body toward the first inlet.
A switching member for a manhole, configured such that when the switching member is positioned in the second switching position, it is possible to allow water to flow from the second inlet into the manhole body, and to block water flowing from the manhole body toward the second inlet.