TWI674344B - Storage tank, siphon-style drainage system and outflow pipe connection member - Google Patents

Abstract

The storage tank is provided with: a storage tank body (32) for storing the liquid flowing into the interior from the upstream side; and a flow path narrowing section (36S) provided at the downstream side and the downstream side of the storage tank body (32). The cross-sectional area is smaller than the upstream side, and the inner bottom (36G) is lower than the inner bottom of the storage tank body (32); and the outflow port (OUT) is located downstream of the flow path reduction portion (36S), so that the liquid Flow out of the storage tank body (32). Use this storage tank to build a siphonic drainage system. The outflow pipe connection member (36) is provided with a flow path reducing portion (36S) and an outflow port (OUT), and is assembled to the storage tank body (32).

Description

Storage tank, siphonic drainage system and outflow pipe connecting member (2)

The invention relates to a storage tank, a siphon type drainage system and an outflow pipe connecting member.

The following Patent Document 1 discloses a siphon type drainage system. The siphon type drainage system is connected to the upstream side of the transverse guide pipe with a water appliance, and the downstream side of the transverse guide pipe maintains a drop relative to the upstream side and is connected to the upright pipe. Thereby, water is drained from the water appliance to the upright pipe by using the siphon force. The siphon type drainage system is provided with a rectangular storage tank (cavity) as a water storage mechanism on the upstream side of the lateral guide pipe. The storage tank temporarily stores the drainage in the case of a large amount of drainage from the water appliance at one time.

Prior art literature

Patent Document 1 Japanese Patent Laid-Open No. 2006-336322

In the above-mentioned siphon type drainage system, the drainage flowing into the storage tank will violently collide with the wall surface near the outflow, causing the outflow of the drainage from the outflow to be blocked. Therefore, the amount of outflow of drainage is reduced, and there is room for improvement.

The present invention has been made in consideration of the above-mentioned facts, and an object thereof is to obtain a storage tank, a siphon type drainage system, and an outflow pipe connection member which can easily flow out liquid from an outflow port and can increase the outflow amount of liquid.

A storage tank according to a first embodiment of the present invention includes a storage tank body capable of storing liquid flowing into the interior from an upstream side, and a flow path narrowing portion provided in the storage tank body. On the downstream side, the cross-sectional area of the downstream side is smaller than the upstream side, and the inner bottom is lower than the inner bottom of the storage tank body; and the outflow port is provided on the downstream side of the reduced portion of the flow path, so that the liquid is directed toward The outside of the storage tank body flows out.

According to the storage tank of the first embodiment, the storage tank body can store the liquid flowing from the upstream side into the interior. A flow path reducing section is provided on the downstream side of the storage tank body, and a flow outlet for allowing liquid to flow out of the storage tank body is provided on the downstream side of the flow channel reducing section.

Here, the inner bottom of the flow path narrowing portion is lower than the inner bottom of the storage tank body. Therefore, the liquid flowing from the upstream side to the downstream side of the storage tank body is changed in the direction of the flow path reduction portion to the downward direction, and it becomes difficult to touch the inner wall surface of the flow path reduction portion, and flows out from the outlet to the outside of the storage tank body . Therefore, the flow of the liquid from the upstream side toward the outflow port becomes difficult to be suppressed by the liquid that does not flow out of the outflow port.

The storage tank according to the second aspect of the present invention is a storage tank according to the first embodiment. The flow path reduction portion is configured with a first flow path reduction portion on the storage tank body side and the outflow port. The second flow path narrowing portion on the side; the outflow port is formed by a tubular outflow pipe connection portion extending from the second flow path narrowing portion to the downstream side.

According to the storage tank of the second embodiment, the flow path reducing portion includes a first flow path reducing portion on the storage tank body side and a second flow path reducing portion on the outflow port side. The outflow port is formed by a tubular outflow pipe connection portion extending from the second flow path narrowing portion to the downstream side. That is, the cross-sectional area of the flow path of the second flow-path reduced portion is larger than the cross-sectional area of the flow path of the outflow pipe connection portion. Therefore, the amount of liquid flowing into the second flow path reducing portion becomes larger, and the amount of liquid flowing from the outflow port can be increased. In addition, since the amount of liquid that does not flow out of the outflow port decreases, the flow of the liquid from the upstream side toward the outflow port is less likely to be suppressed by the liquid that does not flow out of the outflow port.

The storage tank according to the third embodiment of the present invention is a storage tank according to the second embodiment, and the second flow path reducing portion expands in the vertical direction as it goes upstream.

According to the storage tank of the third embodiment, since the second flow path reducing portion expands in the vertical direction as it goes upstream, the amount of liquid flowing into the second flow path reducing portion is changed to the downward direction, which increases the amount of liquid that can flow in and increases. The outflow of liquid from the outflow. In addition, since the amount of liquid that does not flow out of the outflow port decreases, the flow of the liquid from the upstream side toward the outflow port is less likely to be suppressed by the liquid that does not flow out of the outflow port.

The storage tank according to the fourth embodiment of the present invention is a storage tank according to the second embodiment, and a shunt wall surface bulging toward the storage tank body side is formed in the second flow path reduction portion.

In the storage tank according to the fourth embodiment, a shunt wall surface is formed in the second flow path reduction portion, and the shunt wall surface bulges toward the storage tank body side. Therefore, the flow direction of the liquid that touches the split wall surface does not change sharply, but changes gently toward the outlet. Therefore, the liquid that touches the split wall surface does not stay near the split wall surface and can flow out of the outlet. As a result, the flow of the liquid from the upstream side toward the outflow port becomes difficult to be suppressed by the liquid that does not flow out of the outflow port.

A storage tank according to a fifth embodiment of the present invention is a storage tank according to a second embodiment, and an inner wall surface bulging toward the outer side of the first channel reduction section is provided in the first channel reduction section.

According to the storage tank according to the fifth embodiment, since the inner wall surface bulging toward the outside of the first flow path reduction portion is provided in the first flow path reduction portion, the storage tank flows from the upstream side to the downstream side of the storage tank body and does not The liquid flowing out of the outflow port will be guided along the inner wall surface to the direction leaving the outflow port. Therefore, the flow of the liquid from the upstream side toward the outflow port becomes difficult to be suppressed by the liquid that does not flow out of the outflow port.

A storage tank according to a sixth embodiment of the present invention is located in the storage tank according to the first embodiment. The storage tank body is provided with an inflow port and an outflow port where the liquid flows into the interior.

According to the storage tank of the sixth embodiment, an inlet is provided on the upstream side of the storage tank body, and the fluid flows into the interior from the inlet. Since the inflow port and the outflow port are opposed to each other, the liquid system flowing from the inflow port flows straight toward the outflow port. Here, even if the liquid flows in a straight line, the flow of the liquid from the upstream side toward the outflow port is not easily suppressed by the liquid that does not flow out of the outflow port.

The storage tank according to the seventh embodiment of the present invention is a storage tank according to the first embodiment, and other storage tanks are connected on the upstream side of the storage tank body through a communication port. The liquid system flows to other storage tanks.

According to the storage tank of the seventh embodiment, when the storage capacity of the storage tank body is exceeded, the liquid can be made to flow to other storage tanks, so the storable flow can be filled by other storage tanks.

The siphon type drainage system of the eighth embodiment of the present invention includes: any storage tank of the first embodiment to the seventh embodiment; and the first piping is a water device and an upstream side of the storage tank. A connection; and a second pipe connected to the outflow port of the storage tank so that The liquid flows out of the standpipe lower than the outflow port.

An siphon type drainage system according to an eighth embodiment includes a storage tank, a first pipe, and a second pipe. The first pipe allows the liquid from the water appliance to flow into the storage tank. If there is more liquid inflow than liquid outflow from the outlet of the storage tank, the inflowing liquid will be stored in the storage tank. The stored liquid is discharged from the outlet of the storage tank through the second pipe. Here, in the storage tanks of the first to seventh embodiments, the liquid flow from the upstream side toward the outflow port is not easily suppressed by the liquid that does not flow out of the outflow port, and the outflow amount of the liquid can be increased. Therefore, the time required for the vertical pipe of the second pipe to be filled with water can be shortened, and the time required to start the siphon force can be shortened.

The outflow pipe connection member according to the ninth embodiment of the present invention can be assembled on the downstream side of the storage tank body that can store the liquid flowing from the upstream side into the interior; it has a flow path narrowing section and a downstream flow path The cross-sectional area is smaller than the upstream side, and the inner bottom is lower than the inner bottom of the storage tank body; and the outflow port is provided on the downstream side of the flow path reduction portion, so that the liquid flows out of the flow path reduction portion.

In the ninth embodiment, the outflow pipe connecting member includes a flow path reduction portion and an outlet. The inner bottom portion of the flow path reduction portion is lower than the inner bottom portion of the storage tank body. Here, the outflow pipe connection member may be assembled on the downstream side of the storage tank body. Therefore, by assembling the outflow pipe connection member to the storage tank body, a storage tank in which the flow of the liquid from the upstream side toward the outflow port is not easily suppressed by the liquid not flowing out of the outflow port can be easily manufactured.

The storage tank, the siphon type drainage system and the connection member of the outflow pipe of the present invention have the excellent effects that the liquid can be easily outflowed from the outflow port and the outflow of liquid can be increased.

10‧‧‧Siphonic drainage system

14‧‧‧ Water appliances

22‧‧‧The first piping

24‧‧‧ 2nd piping

28‧‧‧ Upright

30‧‧‧Storage tank

32‧‧‧Storage tank body

32C‧‧‧Internal

34‧‧‧Inlet pipe connection member

34B‧‧‧Inlet pipe connection

34D‧‧‧ Overflow pipe connection

36‧‧‧ Outlet pipe connection member

36S‧‧‧Flow Path Reduction Department

36A‧‧‧The first flow path reduction section

36B‧‧‧Second flow path reduction section

36D‧‧‧ Diverting wall surface

36E‧‧‧Inner wall surface

36G‧‧‧Inner bottom

36J‧‧‧Outflow pipe connection

40‧‧‧The first storage department

50‧‧‧Second storage section

60‧‧‧ Overflow tube

62‧‧‧ Snorkel

IN‧‧‧Inlet

OUT‧‧‧ Outlet

Fig. 1 is a schematic side view of a siphon type drainage system according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a storage tank of the siphonic drainage system shown in FIG. 1. FIG.

FIG. 3 is a side view of an inflow pipe connection member that can be assembled at the storage tank shown in FIG. 2.

FIG. 4 is a top view of the inflow pipe connection member shown in FIG. 3.

Fig. 5 is a cross-sectional view of the inflow pipe connection member shown in Figs. 3 and 4 (a cross-sectional view taken along line A-A in Fig. 4).

FIG. 6 is a side view of an outflow pipe connecting member that can be assembled at the storage tank shown in FIG. 2.

FIG. 7 is a top view of the outflow pipe connecting member shown in FIG. 6.

FIG. 8 is a cross-sectional view of a connection portion of an outflow pipe shown in FIGS. 6 and 7 (a cross-sectional view taken along line B-B in FIG. 7).

FIG. 9 is a sectional perspective view of the outflow pipe connection portion shown in FIG. 6 and FIG. 7.

Fig. 10 (A) is a schematic side view showing the liquid outflow state when the storage tank of the first embodiment is half full of water, and Fig. 10 (B) is a view showing the outflow state of the same flow of liquid in the storage tank of the first comparative example. FIG. 10 (C) is a schematic side view showing the outflow state of the same flow of liquid in the storage tank of the second comparative example.

FIG. 11 (A) is a schematic side view showing the liquid outflow state of the storage tank of the first embodiment when it is nearly full of water, and FIG. 11 (B) is a liquid outflow of the same flow rate of the storage tank of the first comparative example. A schematic side view of the state. FIG. 11 (C) is a schematic side view showing the outflow state of the liquid of the same flow rate in the storage tank of the second comparative example.

Fig. 12 (A) is a schematic perspective view of a storage tank and an outflow pipe connecting member according to a second embodiment of the present invention, and Figs. 12 (B) to (E) are storage tanks and outflow pipes of the first modification to the fourth modification. Schematic perspective view of the connecting member.

FIG. 13 (A) is a schematic cross-sectional view of an inner wall surface of a wall portion of an outflow pipe connecting member of a storage tank according to a third embodiment of the present invention, and FIG. 13 (B) is an inner wall surface of a fifth modification corresponding to ( A) is a schematic cross-sectional view, and FIG. 13 (C) is a schematic cross-sectional view of the inner wall surface of the sixth modification corresponding to (A).

[First Embodiment]

A storage tank, a siphon type drainage system, and an outflow pipe connection member according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 11. Here, the arrow X suitable for display in the figure indicates the flow path direction from the upstream side to the downstream side in the horizontal direction, and the arrow Y indicates the direction orthogonal to the flow path direction in the horizontal direction. In addition, the arrow Z indicates that it is vertically upward with respect to the flow path direction. In addition, the application directions of the storage tank, the siphon type drainage system, and the outflow pipe connection member of the first to third embodiments are not limited.

(Construction of Siphonic Drainage System 10)

As shown in FIG. 1, the siphon type drainage system 10 of this embodiment is provided with a water appliance 14, a first pipe 22, a storage tank 30, a second pipe 24, and an upright pipe 28 disposed on a building slab 12. As the main component.

The water appliance 14 in this embodiment is configured to include a bathtub 16, a bathing area 18, a drainage pipe 20A, and a drainage well 20B. The water appliance 14 is disposed upstream of the storage tank 30 in the liquid flow path (here, the drain flow path for draining water). The configuration of the water appliance 14 is not limited to this example. The first piping 22 is piping on the layer plate 12 in a slightly horizontal state. One end portion on the upstream side of the first pipe 22 is connected to the drainage well 20B of the water appliance 14, and the downstream side of the first pipe 22 is connected to the storage tank 30.

The second pipe 24 is piped to the storage tank 30 on the downstream side. One end portion 24A on the upstream side of the second piping 24 is connected to the storage tank 30, and the end portion 24A to the intermediate portion 24B of the second piping 24 is piped to the laminate 12 in a slightly horizontal state in the form of a lateral guide pipe. The other end portion 24C on the downstream side of the second piping 24 is piped in a downward direction along the upright pipe 28 extending from the middle portion 24B to the lower side in the vertical direction in the form of a riser, and is opposite to the storage tank 30 and one end The connection position where the portion 24A is at a lower position is connected to the upright pipe 28 with a drop H1. This connection uses a joint 26.

The siphon type drainage system 10 can discharge water from the water appliance 14 to the upright pipe 28 through the first pipe 22, the storage tank 30, the second pipe 24, and the junction joint 26. Drainage can utilize siphon force. In addition, when a large amount of water is discharged from the water appliance 14 at one time, the water can be temporarily stored in the storage tank 30.

(Structure of Storage Tank 30)

As shown in FIG. 2, the storage tank 30 includes a storage tank body 32, an inflow pipe connection member 34, and an outflow pipe connection member 36 as main components. In addition, the storage tank 30 is provided with a first storage unit 40 and a second storage unit 50 as viewed from the storage tank body 32 and provided with other storage tanks for temporarily storing drainage exceeding the storage capacity of the storage tank body 32. In this embodiment, the storage tank 30 is provided with two first storage sections 40 and second storage sections 50, and the number of other storage tanks can be adjusted according to the flow rate of the drainage flowing into the siphon drainage system 10 at a certain time. Increase or decrease. For example, when the drainage capacity is small, the first storage portion 40 is provided in the storage tank 30. When the drainage capacity is large, in addition to the first storage section 40 and the second storage section 50, a plurality of storage sections are provided in the storage tank 30.

(Structure of Storage Tank Body 32)

The storage tank body 32 is formed in a cylindrical tube shape from the upstream side to the downstream side in the direction of the tube axis C1 (see FIG. 5) as the long side direction. The storage tank body 32 is formed using a resin material such as vinyl chloride, a non-ferrous metal material, a metal material such as iron, and other elastic materials such as rubber. The storage tank body 32 has an enlarged diameter relative to the first piping 22 and the second piping 24, and can temporarily store the drain water flowing from the upstream side into the interior 32C of the storage tank body 32.

(Construction of the inflow pipe connection member 34)

The inflow pipe connection member 34 can be assembled on the upstream side of the storage tank body 32. As shown in FIG. 2 to FIG. 5, the inflow pipe connection member 34 includes a wall portion (upstream side wall portion) 34A, an inflow pipe connection portion 34B, a main body connection portion 34C, and a crossflow pipe connection portion 34D as main components. The wall portion 34A blocks the one end portion 32A on the upstream side of the storage tank body 32, and together with the storage tank body 32 and the outflow pipe connection member 36 (the flow path reducing portion 36A), the interior 32C becomes a closed space. The wall portion 34A is formed in a shape protruding toward the upstream side.

The inflow pipe connection portion 34B is disposed at a lower portion in the vertical direction of the wall portion 34A, and is extended from the downstream side to the upstream side in the direction of the pipe axis C2 to form a cylindrical pipe shape. The pipe axis C2 of the inflow pipe connection portion 34B is located at the lower part of the vertical direction with respect to the pipe axis C1 of the storage tank body 32, and is located at the vertical direction position P1 at the bottom of the pipe shaft C1 and one end 32A of the storage tank body 32 (see FIG. 5) The middle of both. One end portion (not shown) on the upstream side of the inflow pipe connection portion 34B is connected to the other end portion of the first pipe 20 shown in FIGS. 1 and 2. The other end portion (not shown) on the downstream side of the inflow pipe connection portion 34B is integrally formed with the wall portion 34A as shown in FIGS. 3 to 5. The upstream side of the inflow pipe connection portion 34B becomes the inflow port IN so that the drainage flows from the first pipe 22 through the inflow pipe connection portion 34B into the inside 32C of the storage tank body 32.

The upstream side of the main body connection portion 34C is integrally formed around the peripheral edge of the wall portion 34A, and is extended from the upstream side to the downstream side in the direction of the tube axis C1 of the storage tank body 32 to form a cylindrical tube. The body connecting portion 34C is set to have an inner diameter that is the same as or slightly larger than the outer diameter of the storage tank body 32, and one end portion 32A of the storage tank body 32 is inserted into the inside to make a connection. To the main body connection portion 34C and the wall portion 34A (either the inflow pipe connection portion 34B or the overflow pipe connection portion 34D) The boundary portion is provided with a stepped vertical wall 34F that is reduced in diameter compared to the inner diameter of the body connecting portion 34C. Inside the body connecting portion 34C, one end portion 32A of the storage tank body 32 can be inserted up to the stepped vertical wall 34F. The stepped vertical wall 34F is used for assembling the inflow pipe connection member 34 to the positioning of the storage tank body 32.

Here, as shown in FIG. 5, in a state (connected state) where one end portion 32A of the storage tank body 32 is assembled to the inflow pipe connection member 34, the vertical position P1 of the inner bottom portion of the one end portion 32A is connected to the inflow pipe connection portion. The vertical position P2 at the bottom of 34B is the same. That is, a stepped portion is not formed in the drainage flow path from the inflow pipe connection portion 34B to the storage tank body 32.

The overflow pipe connection portion 34D is disposed at the upper portion in the vertical direction of the wall portion 34A, and is extended to form a cylindrical pipe shape from the downstream side to the upstream side along the direction of the pipe axis C3. The tube axis C3 is located in the vertical upper part with respect to the tube axis C1 of the storage tank body 32, and the vertical position P6 (see FIG. 5) of the tube shaft C1 and the tube inner upper part of one end portion 32A of the storage tank body 32 The middle. One end (not shown) on the upstream side of the crossover connection portion 34D is connected to the first storage portion 40 and the second storage portion 50 shown in FIG. 2. The other end portion (not shown) on the downstream side of the crossover connection portion 34D is integrally formed with the wall portion 34A as shown in FIGS. 3 to 5. The downstream side of the overcoming pipe connection portion 34D is a communication port OF, and communicates with the first storage portion 40 and the second storage portion 50 that allow the drainage from the inside 32C of the storage tank body 32 to overflow.

Since the inflow pipe connection member 34 has a complicated structure including the inflow pipe connection portion 34B and the like, it is formed by, for example, injection molding using a resin material such as vinyl chloride.

(Construction of Outflow Pipe Connection Member 36)

The outflow pipe connection member 36 can be assembled on the downstream side of the storage tank body 32. As shown in FIGS. 2, 6 to 8, the outflow pipe connection member 36 mainly includes a flow path reducing portion (a reduced diameter portion in the case of a cylindrical shape) 36S. Compared with the upstream side, the downstream side flow path The cross-sectional area (the cross-sectional area of the drainage path) is small; and the body connection portion 36C. In addition, the main structure of the flow path reduction portion 36S includes a first flow path reduction portion 36A as a downstream side wall portion whose flow path cross-sectional area is reduced from the upstream side to a downstream side; and a second flow path reduction portion 36B, which The flow path cross-sectional area is smaller than the first flow path reducing portion 36A from the upstream side to the downstream side. The first flow path reducing portion 36A is connected to the other end portion 32B on the downstream side of the storage tank body 32, and is connected to the storage tank body 32 and the inflow pipe connection structure. The pieces 34 (the wall portion 34A) together make the interior 32C a closed space. The first flow path narrowing portion 36A is formed in a hemispherical shape protruding to the downstream side in a side view and a plan view in an outer shape. In addition, as shown in FIG. 8, at least a part of the inner wall surface 36E of the first flow path reduction portion 36A is a curved surface that bulges (recesses) outside the first flow path reduction portion 36A to the downstream side. To explain in detail, in this embodiment, the intersection position of the first flow path reducing portion 36A and the main body connection portion 36C and the intersection of the pipe axis C1 is taken as the center position Pc, and the half of the pipe diameter of the storage tank body 32 1 is the radius R1, the inner wall surface 36E system and the curve drawn on the downstream side are substantially the same.

The second flow path reduction portion 36B is disposed at a lower portion in the vertical direction of the first flow path reduction portion 36A, and is extended from the upstream side to the downstream side in the direction of the tube axis C4 to form a cylindrical tube. The tube axis C4 of the second flow path reduction portion 36B is located at a lower position in the vertical direction with respect to the tube axis C1 of the storage tank body 32, and in a vertical position P1 with respect to the tube axis C1 and the inner bottom of the other end portion 32B of the storage tank body 32 (See FIG. 8) The intermediate portion of the two is shifted toward the vertical position P1. One end portion (not shown) on the upstream side of the second flow path reduction portion 36B is integrally formed in the first flow path reduction portion 36A as shown in FIGS. 6 to 8. The downstream side of the second flow path reducing portion 36B and the tubular outflow pipe connecting portion 36J (extended from the upstream side to the downstream side, and the flow path cross-sectional area is constant) are integrally formed. The tube axis C4 and the second flow path reducing portion 36B coincide with the outflow pipe connection portion 36J. The second flow path narrowing portion 36B and the outflow pipe connection portion 36J allow the drain water from the inside 32C of the storage tank body 32 to flow out of the storage tank 30. The downstream side of the outflow pipe connection portion 36J is an outflow outlet OUT that allows drainage to flow out of the storage tank 30. The outflow port OUT is arranged opposite to the inflow port IN of the inflow pipe connection member 34 in this embodiment. The inflow port IN and the outflow port OUT are arranged vertically below the tube axis C1 of the storage tank body 32. The outflow outlet OUT of the outflow pipe connection portion 36J is connected to one end portion 24A of the second pipe 24 shown in FIGS. 1 and 2.

As shown in FIG. 8, the tube axis C4 of the second flow path reduction portion 36B (and the outflow pipe connection portion 36J) is offset from the tube axis C1 of the storage tank body 32 as described above. In addition, the position P5 on the upstream side end of the inner bottom portion 36G of the second flow path narrowing portion 36B extends to the upstream side from the position P4 on the upstream side end of the inner upper portion 36H. Further, the vertical position P3 of the inner bottom portion 36G of the second flow path reduction portion 36B is lower than the vertical position P1 of the bottom (inner bottom portion) of the inner portion 32C of the storage tank body 32. With this configuration, the second flow path narrowing section 36B The cross-sectional area of the upstream flow path is enlarged, and the second flow path reducing portion 36B can increase the amount of liquid flowing out to the outflow port OUT. To explain in detail, the position P4 is a position on the most downstream side of the inner wall surface 36E of the first flow path narrowing portion 36A. The inner bottom portion 36G of the second flow path reduction portion 36B extends from this position P4 to a position P5 on the upstream side by a size L. The position P5 is located on the upstream side with respect to the connection portion between the second flow path reduction portion 36B and the first flow path reduction portion 36A.

The flow path cross section of the second flow path reducing portion 36B expands toward the upstream side as shown in FIG. 8 in particular. To explain in detail, the second flow path reducing portion 36B extends from the junction with the outflow pipe connection portion 36J to the upstream opening portion (equivalent to the interface with the first flow path reducing portion 36A) so that the upper portion 36H is vertically upward. Side expansion. In this embodiment, the opening portion of the expanded portion on the upstream side of the second flow path reducing portion 36B is configured as a curved shunt wall surface 36D that bulges upstream. Taking the intersection of the extension line of the tube axis C1 of the storage tank body 32 and the vertical line passing through the boundary between the second flow path reducing portion 36B and the outflow pipe connection portion 36J as the center position Po, it will be smaller than the radius R1. When the dimension is set to the radius R2, the branch wall surface 36D and the curve drawn on the upstream side are substantially the same.

As shown in FIGS. 6 to 8, the downstream side of the main body connecting portion 36C is integrally formed on the periphery of the first flow path reducing portion 36A, and is extended from the upstream side to the downstream side in accordance with the tube axis C1 of the storage tank body 32. Formed into a cylindrical tube. Like the main body connection portion 34C of the inflow pipe connection member 34, the main body connection portion 36C sets the inner diameter to be the same as or relatively larger than the outer diameter of the storage tank body 32, and sets the other end portion of the storage tank body 32 The 32B is plugged in for connection. A stepped vertical wall 36F that is reduced in diameter with respect to the inner diameter of the main body connecting portion 36C is provided at the boundary portion of the main body connecting portion 36C and the first flow path reducing portion 36A. Inside the body connecting portion 36C, the other end portion 32B of the storage tank body 32 can be inserted into the step vertical wall 36F. The step vertical wall 36F is used to assemble the outflow pipe connection member 36 to the storage tank body 32 for positioning.

As shown in FIG. 8, in a state where the other end portion 32B of the storage tank body 32 is assembled to the outflow pipe connection member 36 (connected state), the vertical position P1 of the inner bottom portion of the other end portion 32B is part of the step vertical wall 36F. It coincides with the vertical position (the symbol is omitted) of the inner bottom portion of the second flow path reducing portion 36B. That is, it is comprised so that a drainage flow path may not generate a step part from the storage tank main body 32 to the flow-path reduction part 36S.

In addition, the outflow pipe connection member 36 may be made of the same material and formed as the inflow pipe connection member 34.

(Configuration of the first storage section 40 and the second storage section 50)

As shown in FIG. 2, the first storage section 40 and the second storage section 50 are arranged in parallel with each other in the horizontal direction with respect to the storage tank body 32. The first storage unit 40 mainly includes a storage tank body 42 having the same structure as the storage tank body 32, an inflow pipe connection member 44 having the same structure as the inflow pipe connection member 34, and an outflow pipe connection member 36 having the same structure. Of the outflow pipe connection member 46. In this embodiment, the inflow pipe connection portion (not shown) of the inflow pipe connection member 44 is connected to the first pipe 20 (not shown), and the overflow pipe connection portion 44D is connected via the overflow pipe (connecting pipe) 60. The inflow pipe connection portion 34D is connected to the inflow pipe connection member 34. The second pipe 24 is connected to the outflow pipe connection member 46.

The second storage unit 50 and the first storage unit 40 are mainly composed of a storage tank body 52 having the same structure as the storage tank body 32, an inflow pipe connection member 54 having the same structure as the inflow pipe connection member 34, and The outflow pipe connection member 36 is an outflow pipe connection member 56 of the same configuration. The inflow pipe connection portion (not shown) of the inflow pipe connection member 54 is connected to the first pipe 20 (not shown), and the overflow pipe connection portion 54D is connected to the overflow pipe connection portion 34D and the Vietnam via the overflow pipe 60. Flow tube connection 44D. The overflow pipe 60 has three connection parts on the downstream side which are connected to the separate parts of the overflow pipe connection parts 34D, 44D, and 54D, respectively. The upstream side is connected to the three connection parts (not shown), and an E-shaped pipe is used in plan view. Formed. A second pipe 24 is connected to the outflow pipe connection member 56. In addition, the crossover pipe 60 may not be provided, and the crossover pipe connection portions 34D, 44D, and 54D may be directly connected.

As shown in FIG. 2, one end portion (the symbol is omitted) of the upstream side of the vent tube 62 is connected to the overflow tube 60. In detail, one end portion of the vent pipe 62 is connected to the crossover pipe 60 at an intermediate portion between the crossover pipe connection portion 44D and the crossover pipe connection portion 54D. The other end portion on the downstream side of the overflow pipe 60 is connected to the second pipe 24 in this embodiment. In addition, the ventilation duct 62 may not be provided, and it may be comprised so that a storage tank may not escape the internal air.

In addition, as shown in FIG. 2, the height in the vertical direction on the upstream side of the storage tank 30 is set by a height H2 that is slightly higher than the height in the vertical direction on the downstream side. That is, the storage tank 30 is inclined from the upstream side toward the downstream side toward the lower side in the vertical direction. With this structure, the storage tank 30 can be increased The liquid level (water level) of the outflow outlet OUT shortens the time required for the standpipe (the other end portion 24C of the second piping 24) to be full of water, and can shorten the time required for the siphon force to start. Moreover, the liquid in the storage tank 30 can be prevented from remaining.

In addition, the storage tank 30 of the present embodiment includes three constituent parts: a storage tank body 32, an inflow pipe connection member 34, and an outflow pipe connection member 36. An inflow pipe connection member 34 is assembled on the upstream side of the storage tank body 32, an outflow pipe connection member 36 is assembled on the downstream side of the storage tank body 32, and the storage tank 30 is assembled. In addition, the storage tank body 32, the inflow pipe connection member 34, and the outflow pipe connection member 36 may be integrally formed.

(Action and effect of this embodiment)

As shown in FIG. 2, in the storage tank 30 of this embodiment, the storage tank body 32 can store the drainage flowing into the interior 32C from the upstream side. A flow path reducing portion 36S is provided on the downstream side of the storage tank body 32, and a flow outlet OUT (see FIG. 8) is provided at the flow path reducing portion 36S for draining water to the outside of the storage tank body 32.

Here, as shown in FIG. 8, a part of the flow path reducing portion 36S provided on the downstream side of the storage tank body 32 is provided with an inner wall surface that bulges (curved toward the downstream side) outside the flow channel reducing portion 36S. 36E. As shown in FIG. 9, a part of the lower part of the drain (liquid) F1 in the vertical direction flowing from the upstream side to the downstream side of the storage tank body 32 is passed through the flow path reducing portion 36S of the outflow pipe connection member 36 as the drain F2. The second pipe 24 (see FIGS. 1 and 2) flows out. The other part of the vertical upper part of the drainage F1 that does not flow out of the flow outlet OUT (see FIG. 8) of the flow path narrowing portion 36S touches the inner wall surface 36E (or the branch wall surface 36D) of the flow narrowing portion 36S as The drain water F3 flows along the inner wall surface 36E.

FIG. 10 (A) shows the state of the downstream side when the storage tank 30 of the embodiment is half full. In the figure, the arrows show the flow of the drainage finely. As described above, the other part of the drainage F1 is in contact with the inner wall surface 36E of the first flow path reduction portion 36A of the flow path reduction portion 36S, and the drainage F3 flows along the inner wall surface 36E. As shown in FIG. 11 (A), similar to when the water is almost full, the other part of the drainage F1 touches the inner wall surface 36E, and the drainage F3 flows along the inner wall surface 36E. In particular, as shown in FIG. 11 (A), the drainage F3 near the outflow port OUT (see FIG. 8) is guided along the inner wall surface 36E of the first flow path narrowing portion 36A from the outflow port OUT to a vertical separation direction upward. Therefore, the outflow port OUT from the upstream side to the downstream side of the storage tank 30 The flow of the drain F1 is not easily suppressed by the drains F3 and F4 that do not flow out of the outflow port OUT. Therefore, according to the storage tank 30 of this embodiment, the drainage F2 can be easily discharged from the outflow port OUT, and the outflow capacity of the drainage F2 can be improved.

On the other hand, in the storage tank 80 of the second comparative example shown in FIG. 10 (C) and FIG. 11 (C), the inner wall surface 86E of the first flow path reduction portion 86A of the outflow pipe connection member 86 has its upper portion inclined toward the upstream side. It is flat. The storage tank 80 is not provided with a portion corresponding to the second flow path reducing portion 36B of the present embodiment. In addition, the storage tank 80 is provided with an outflow pipe connection portion 86J corresponding to the outflow pipe connection portion 36J of the present embodiment. In the storage tank 80 of the second comparative example, whether it is half-full or near-full, the other part of the drainage F1 will collide with the inner wall surface 86E, and the drainage F5 will be retained due to turbulence and backflow. Affected by the drainage F5, the flow of a part of the drainage F1 is hindered, and the drainage F2 from the outflow pipe connection portion 86J to the outflow port is difficult to flow out, and the amount of drainage F2 is reduced.

In addition, in the storage tank 30 of this embodiment, as shown in FIG. 8, the inner bottom portion 36G of the second flow path reduction portion 36B of the flow path reduction portion 36S in the outflow pipe connection member 36 is lower than the inner bottom portion of the storage tank body 32. . In detail, the inner bottom 36G extends a distance L from the most downstream side position P4 of the inner wall surface 36E to the upstream side to reach the position P5, and the vertical position P3 of the inner bottom 36G is relatively vertical to the inner bottom of the storage tank body 32 The directional position P1 comes low.

As shown in FIGS. 9, 10 (A), and 11 (A), the drainage F1 flowing from the upstream side to the downstream side of the storage tank body 32 is changed to a downward flow at the flow path reducing portion 36S, which makes it difficult to touch. The inner wall surface 36E touches the second channel narrowing portion 36B (from the outflow port OUT) to the outside of the storage tank body 32 as the drainage F2 and flows out easily. Therefore, the flow of the drainage F1 from the upstream side toward the downstream outlet OUT of the storage tank 30 is difficult to be suppressed by the drainage F3 and the drainage F4 that do not flow out of the outlet OUT.

In addition, as shown in FIG. 5, the storage tank 30 of the present embodiment is provided with an inflow port IN on the upstream side (inflow pipe connection member 34) of the storage tank body 32, and flows into the interior 32C from the inflow port IN to drain water. The inflow port IN is opposed to the outflow port OUT on the downstream side (outflow pipe connection member 36) of the storage tank body 32. Therefore, the drainage F1 flowing from the inflow port IN flows straight toward the outflow port OUT. Here, even if the drainage F1 flows in a straight line, as shown in FIG. 8, the inner wall surface 36E of the flow path reducing portion 36S becomes a curved surface that bulges toward the downstream side, so as shown in FIG. 9 and FIG. 10 (A). And as shown in FIG. 11 (A), the flow of the drainage F2 is not easily suppressed. Furthermore, since the drainage F1 flows linearly from the inflow inlet IN to the outflow outlet OUT, the sound potential of the drainage F1 will not be attenuated, and the outflow of the drainage F2 can be increased.

In addition, as shown in FIG. 8, the storage tank 30 of this embodiment includes a first flow path reduction section 36A on the storage tank body 32 side and a second flow path reduction section 36B on the outflow port OUT side. . Here, the second flow path reducing portion 36B is formed into a tubular shape as it expands toward the upstream side. That is, the cross-sectional area of the flow path on the upstream side of the second flow-path reduction portion 36B is larger than the cross-sectional area of the flow path on the downstream side. Therefore, the amount of drain water F2 flowing into the second flow path reducing portion 36B is increased, and the outflow amount of the drain water F2 from the outflow port OUT can be increased. In addition, as shown in FIGS. 9, 10 (A), and 11 (A), since the outflow amount of the drainage F3 that does not flow out of the outflow port OUT is reduced, the flow of the drainage F1 from the upstream side to the outflow port OUT is difficult to cause. The drainage F3 and drainage F4 which have not flowed out of the outflow port OUT are suppressed.

Here, in the storage tank 70 of the first comparative example shown in FIG. 10 (B) and FIG. 11 (B), the outflow pipe connection member 76 includes a first flow path reducing portion 76A and an outflow pipe connection portion 76J, and an outflow pipe connection The cross section of the 76J flow path is constant. A portion corresponding to the second flow path reducing portion 36B of the present embodiment is not provided in the storage tank 70. The inner wall surface 76E of the first flow path reduction portion 76A and the inner wall surface 36E of the first flow path reduction portion 36A of this embodiment shown in Figs. 10 (A) and 11 (A) have the same curved surface. In the storage tank 70 of the first comparative example, the drain F1 flows to the inner wall surface 76E side in a large amount. Therefore, when the drain F1 touches the inner wall surface 76E, the drain F5 is liable to be trapped, whether it is half-full or near-full. Therefore, the flow of the drainage F1 from the upstream side to the outflow port OUT is easily suppressed by the influence of the drainage F5 that does not flow out of the outflow port OUT.

In addition, as shown in FIG. 8, the storage tank 30 of this embodiment has an opening on the upstream side of the second flow path reducing portion 36B forming a shunt wall surface 36D, and the shunt wall surface 36D bulges toward the storage tank body 32 side (becomes upstream Curved side projection). Therefore, the flow direction of the drain F2 that touches the shunt wall surface 36D will not change abruptly, but will gradually change toward the outflow port OUT. Therefore, the drain F2 that touches the shunt wall surface 36D will not stay near the shunt wall surface 36D and can move toward Outflow port OUT flows out. As a result, the flow of the drain water F1 from the upstream side to the outflow port is not easily suppressed by the influence of the drain water F3 and F4 that do not flow out of the outflow port OUT.

Here, the storage tank 70 of the first comparative example shown in FIG. 10 (B) and FIG. 11 (B) is not provided with the shunt wall surface 36D of this embodiment. In the storage tank 70 of the first comparative example, the drain F1 returns to the inlet IN side in the form of drain F5 and the flow rate increases. Therefore, the drain F1 from the upstream side to the outlet is in a half-full or near-full state. The flow is easily suppressed by the drainage F5 that does not flow out of the outflow port OUT.

In addition, as shown in FIG. 8, the storage tank 30 of this embodiment has a cross-sectional area of the flow path near the opening on the upstream side of the second flow path reduction portion 36B, which increases upward in the vertical direction. As a result, the speed of the component in the vertical direction increases, which can increase the outflow of the drainage F2 from the second flow path reducing portion 36B. Therefore, the outflow amount of the drainage F2 from the second flow path reduction portion 36B can be further increased, and the flow rate of the drainage F3 on the inner wall surface 36E side, which is a cause of turbulence or counterflow, can be reduced.

In addition, as shown in FIG. 2, when the storage tank 30 of this embodiment exceeds the storage capacity of the storage tank body 32, the drain water can flow to the first storage section 40 and the second storage section 50. Therefore, the first storage unit 40 and the second storage unit 50 can fill the storable water volume.

In addition, as shown in FIG. 1, the siphon type drainage system 10 according to this embodiment includes a storage tank 30, a first pipe 22, and a second pipe 24. The first pipe 22 allows the drain water from the water appliance 14 to flow into the inside of the storage tank 30 (the inside 32C of the storage tank body 32). If the inflow of the drainage F1 is larger than the outflow of the drainage F2 from the outflow outlet OUT of the storage tank 30, the inflowing drainage F1 will be stored in the storage tank 30. The stored drainage F1 is discharged from the outflow port OUT of the storage tank 30 through the second pipe 24. Here, in the storage tank 30, since the flow of the drainage F1 from the upstream side to the outflow port OUT is not easily suppressed by the drainage F3 and the drainage F4 that do not flow out of the outflow port OUT, the outflow of the drainage F2 can be increased. Therefore, the time required to fill up the vertical pipe (from the middle portion 24B to the other end portion 24C) of the second pipe 24 can be shortened, and the time required to start the siphon force can be shortened.

Furthermore, as shown in FIG. 8, the outflow pipe connection member 36 of the present embodiment is provided with a first flow path reduction portion 36A, and the first flow path reduction portion 36A includes a curved inner wall surface 36E that is recessed toward the downstream side. In addition, the first flow path reducing portion 36A is provided with an outflow port OUT for allowing the drain water F1 to flow out of the storage tank body 32. Here, the outflow pipe connection member 36 may be assembled on the downstream side of the storage tank body 32. Therefore, the outflow pipe connection member 36 is assembled to the storage tank body 32, The storage tank 30 in which the outflow of the drainage F2 from the outflow port OUT is not hindered by turbulence or backflow can be easily manufactured.

In addition, as shown in FIG. 8, the outflow pipe connection member 36 of the present embodiment includes a flow path reducing portion 36S, an outlet port OUT, and an inner wall surface 36E that bulges to the outside of the flow path reducing portion 36S. Here, the outflow pipe connection member 36 may be assembled on the downstream side of the storage tank body 32. Therefore, by assembling the outflow pipe connection member 36 to the storage tank body 32, it is possible to easily create a storage tank in which the flow of the drain F1 from the upstream side to the outflow port OUT is not easily suppressed by the drain F3 and the drain F4 that do not flow out of the outflow port OUT 30.

Furthermore, as shown in FIG. 8, the outflow pipe connection member 36 of this embodiment is provided with a flow path reducing portion 36S and an outlet OUT. The inner bottom portion 36G of the flow path reducing portion 36S is lower than the inner bottom portion of the storage tank body 32. . Here, the outflow pipe connection member 36 may be assembled on the downstream side of the storage tank body 32. Therefore, by assembling the outflow pipe connection member 36 to the storage tank body 32, it is possible to easily create a storage tank in which the flow of the drain F1 from the upstream side to the outflow port OUT is not easily suppressed by the drain F3 and the drain F4 that do not flow out of the outflow port OUT 30.

Therefore, the storage tank 30, the siphon type drainage system 10, and the outflow pipe connection member 36 of this embodiment can easily flow out the drainage F2 from the outflow port OUT, and the outflow amount of the drainage F2 can be increased.

[Second Embodiment]

The storage tank 30 according to the second embodiment of the present invention will be described with reference to FIG. 12. In the description of this embodiment and the third embodiment described later, the same reference numerals are given to the components having the same function as those of the storage tank 30 of the first embodiment, and redundant descriptions are omitted.

As shown in FIG. 12 (A), in the storage tank 30 and the outflow pipe connection member 36 of the present embodiment, the first flow path reduction portion 36A of the flow path reduction portion 36S bulges in a semi-cylindrical shape on the downstream side in plan view. . Although not shown in the figure, the inner wall surface of the first flow path reducing portion 36A has a curved shape recessed toward the downstream side. The second flow path reduction portion 36B is integrally formed at the lowermost side of the first flow path reduction portion 36A in the vertical lower portion. The storage tank body 32 has a rectangular tube shape in this embodiment.

As shown in FIG. 12 (B), in the storage tank 30 of the first modified example, in the outflow pipe connection member 36, the first flow path reduction portion 36A of the flow path reduction portion 36S is bulged to the downstream side in a side view. It is semi-cylindrical. Although not shown, the inner wall surface of the first flow path reducing portion 36A becomes Curved shape recessed to the downstream side. The second flow path reduction portion 36B is integrally formed at the middle portion in the vertical direction on the most downstream side of the first flow path reduction portion 36A.

As shown in FIG. 12 (C), in the storage tank 30 of the second modification example, the first flow path reduction portion 36A of the flow path reduction portion 36S in the outflow pipe connection member 36 is bulged to the downstream side in a plan view. Semi-cylindrical. Although not shown in the figure, the inner wall surface of the first flow path reducing portion 36A has a curved shape recessed toward the downstream side. The second flow path reduction portion 36B is integrally formed at a lower portion in the vertical direction at a position shifted laterally from the most downstream side of the first flow path reduction portion 36A.

As shown in FIG. 12 (D), in the storage tank 30 according to the third modification, the first flow path reduction portion 36A of the flow path reduction portion 36S in the outflow pipe connection member 36 is bulged to the downstream side in plan view. It is semi-cylindrical, and the upper part of the first flow path reducing portion 36A is inclined downward from the storage tank body 32 toward the second flow path reducing portion 36B in the vertical direction. Although not shown in the drawings, the inner wall surface of the first flow path reducing portion 36A is provided with a curved portion that is recessed toward the downstream side. The second flow path reduction portion 36B is connected to the lower portion in the vertical direction at the most downstream side of the first flow path reduction portion 36A.

As shown in FIG. 12 (E), in the storage tank 30 of the fourth modification, in the outflow pipe connection member 36, the first flow path reduction portion 36A of the flow path reduction portion 36S swells two semicircles to the downstream side in plan view. The tube portion is formed in an M shape. Although not shown in the drawings, the inner wall surface of the first flow path reducing portion 36A is provided with two curved portions that are recessed toward the downstream side. Although it is not explicitly shown in FIG. 12 (E), the 2nd flow-path reduction part 36B is provided between the 1st flow-path reduction part 36A and the outflow pipe connection part 36J. The second flow path reduction portion 36B is integrally formed between the semi-cylindrical portions at a lower portion of the first flow path reduction portion 36A in the vertical direction.

(Action and effect of this embodiment)

The storage tank 30 of this embodiment can obtain the same effect as that obtained by the storage tank 30 of the first embodiment. The same effect can be obtained with respect to the siphon type drainage system 10 and the outflow pipe connection member 36.

In addition, in the storage tank 30 of this embodiment and the first modification to the fourth modification, a composite surface formed by a combination of a flat surface and a curved surface may be used to form the first flow path reduction portion 36A of the outflow pipe connection member 36. Wall surface (36E). Therefore, the inner wall surface 36E (refer to FIG. 8) where the drainage F2 flows easily can be simply formed.

[Third Embodiment]

A storage tank 30 according to a third embodiment of the present invention will be described with reference to FIG. 13.

As shown in FIG. 13 (A), in the storage tank 30 of the present embodiment, in the outflow pipe connection member 36, the inner wall surface 36E of the first flow path reduction portion 36A of the flow path reduction portion 36S is used to change the angle of the complex plane FS The continuous multi-faceted surface is formed into a curved shape that is recessed toward the downstream side.

As shown in FIG. 13 (B), in the storage tank 30 of the fifth modification, the inner wall surface 36E of the flow path reducing portion 36S in the outflow pipe connection member 36 is a combination of a plane FS and a plurality of curved surfaces CS (multifaceted). The composite surface is formed into a curved shape that is recessed toward the downstream side. In the fifth modification, the most downstream side of the inner wall surface 36E is a plane FS.

As shown in FIG. 13 (C), in the storage tank 30 of the sixth modification, the inner wall surface 36E of the flow path reducing portion 36S in the outflow pipe connection member 36 is a combination of a curved surface CS and a complex plane FS (multifaceted). The composite surface is formed into a curved shape recessed toward the downstream side. In the sixth modification, the most downstream side of the inner wall surface 36E is a curved surface CS.

(Action and effect of this embodiment)

The storage tank 30 of the present embodiment can obtain the same effects as those obtained by the storage tank 30 of the first embodiment. The same effect can be obtained with respect to the siphon type drainage system 10 and the outflow pipe connection member 36.

In addition, as shown in FIGS. 13 (A) to 13 (C), the storage tank 30 of this embodiment, the fifth modification, and the sixth modification can use a multi-surface (complex plane FS), a plane FS, and a curved surface CS. The composite surfaces are combined to form the inner wall surface 36E of the first flow path reducing portion 36A of the outflow pipe connection member 36. Therefore, the inner wall surface 36E where the drainage F2 can easily flow out can be simply formed.

[Other forms]

The present invention is not limited to the above-mentioned embodiments, and various changes can be made within a range not departing from the gist thereof. For example, in the above-mentioned embodiment, although the first flow path reduction portion 36A, the second flow path reduction portion 36B, and the outflow tube connection portion 36J of the outflow pipe connection member 36 are respectively formed integrally, the present invention can also make these separate The parts are formed and assembled with each other to form the outflow pipe connection member 36. In addition, in the above-mentioned embodiment, the storage tank body 32 is formed into a cylindrical shape or a rectangular tube shape, but the present invention may be an oval tube shape, a trapezoidal tube shape, a polygonal tube shape, or the like. The cross-sectional shape of the storage tank body 32 is not limited. . Furthermore, the present invention is not limited to the siphon type drainage system 10 and can be widely applied to a storage tank for storing liquid.

Claims (8)

A storage tank is provided with: a storage tank body capable of storing liquid flowing from the upstream side into the interior; a flow path reducing portion provided on the downstream side of the storage tank body, and a cross-sectional area of the downstream side of the flow path being larger than that of the upstream Comes small, the inner bottom is lower than the inner bottom of the storage tank body; and the outflow port is provided downstream of the flow path reduction section so that the liquid flows out of the storage tank body; the flow path reduction section The structure includes a first flow path reduction portion on the storage tank body side and a second flow path reduction portion on the flow outlet side; the flow outlet is a tubular tube extending from the second flow path reduction portion to the downstream side. The vertical position of the inner bottom of the second flow path reducing portion is lower than the vertical position of the inner bottom of the storage tank body, and further, the inner bottom of the second flow path reducing portion is formed. It extends from the position on the most downstream side of the first flow path narrowing portion, and extends on the upstream side. For example, the storage tank of the first scope of the patent application, wherein the second flow path reducing portion expands in a vertical direction as it goes upstream. For example, in the storage tank of the second scope of the patent application, a shunt wall surface bulging toward the main body side of the storage tank is formed in the second flow path reducing portion. For example, the storage tank of the second scope of the patent application, wherein the first flow path reducing portion is provided with an inner wall surface bulging toward the outside of the first flow path reducing portion. For example, the storage tank according to any one of claims 1 to 4, wherein the storage tank body is provided with an inflow port and an outflow port for the liquid flowing into the interior of the storage tank. For example, the storage tank of any one of claims 1 to 4 of the scope of patent application, wherein the storage tank body is provided with other storage tanks on the upstream side of the storage tank through a communication port, and the liquid system flowing out of the storage tank body flows out. To the other storage tank. A siphon type drainage system comprising: the storage tank according to any one of claims 1 to 6 of the patent application scope; a first piping connecting a water appliance to an upstream side of the storage tank; and a second piping, Is connected to the outflow port of the storage tank, and has The riser coming out at a low position. An outflow pipe connection member can be assembled on the downstream side of a storage tank body that can store liquid flowing from the upstream side into the interior; it has a flow path reduction section, and the flow path cross-sectional area on the downstream side is smaller than that on the upstream side. The inner bottom is lower than the inner bottom of the storage tank body; and the outflow port is provided downstream of the flow path reduction portion so that the liquid flows out of the flow path reduction portion; the composition of the flow path reduction portion The storage channel includes a first flow path reduction portion on the storage tank body side and a second flow path reduction portion on the flow outlet side; the flow outlet is a tubular tube extending from the second flow path reduction portion to the downstream side. The vertical position of the inner bottom of the second flow path reducing portion is lower than the vertical position of the inner bottom of the storage tank body, and further, the inner bottom of the second flow path reducing portion is formed from The first flow path narrowing portion extends from the most downstream position to the upstream side.