JP7398260B2 - drain pipe structure - Google Patents

Description

The present invention relates to a drain pipe structure.

A siphon drainage structure in which two plumbing devices (a kitchen sink and a dishwasher) are connected to one siphon drainage pipe is disclosed (see Patent Document 1). Specifically, a first wastewater inlet pipe through which wastewater from the kitchen sink flows is connected to a siphon drain pipe via a drain trap and a check valve, and a second wastewater inlet pipe through which wastewater from the dishwasher flows. is connected to a first drainage introduction pipe or a horizontal drain pipe (siphon drainage pipe) on the downstream side of the drainage trap. A check valve prevents wastewater from the dishwasher from flowing back into the kitchen sink.

Further, in a similar drainage structure, a technique has been disclosed in which a pressure relief device is used instead of a check valve to relieve pressure rise on the downstream side of a drainage trap (see Patent Document 2).

Japanese Patent Application Publication No. 2016-196744 JP 2018-105035 Publication

By the way, there are two types of dishwashers: models with low drainage pressure and models with high drainage pressure. If the drain pressure is high, the air inside the pipe will be pushed out toward the kitchen sink, and the increased pressure inside the drain pipe may break the water seal of the drain trap. By using the check valve described in Patent Document 1 mentioned above, such breakage of the seal can be suppressed, but the life span due to repeated opening and closing of the check valve becomes an issue. It is also possible to alleviate the pressure increase in the drain pipe by using the pressure relief device described in Patent Document 2 without using a check valve, but the pressure relief is caused by the drainage from the dishwasher flowing back into the kitchen sink. Once the air inlet to the device is reached and the inlet is blocked by backflowing waste water, it becomes difficult for the pressure relief device to alleviate the pressure buildup in the drain pipe.

In a drain pipe structure in which a plurality of plumbing devices are connected to one siphon drain pipe, the present invention is directed to preventing backflow to the upstream plumbing device when draining water from the plumbing device connected downstream. The purpose is to suppress the pressure rise on the water equipment side.

The drain pipe structure according to the first aspect includes: a first drainage system for discharging wastewater from a first plumbing device; a second drainage system for discharging wastewater from a second plumbing device; a drainage system is connected to the upstream side, and the second drainage system is provided to the siphon drainage pipe connected to the downstream side of the first drainage system, and the second drainage system, and the second drainage system is connected to the siphon drainage pipe connected to the downstream side of the first drainage system. and pressure reduction piping that reduces drainage pressure in the drainage system.

In this drain pipe structure, waste water from the first plumbing equipment flows into the siphon drain pipe through the first drainage system. Moreover, the waste water from the second plumbing equipment flows into the siphon drain pipe through the second drainage system. In either case, the inside of the siphon drain pipe becomes full and a siphon force is generated, so that the waste water is sucked downstream. The second drainage system is equipped with pressure reduction piping, so even if the drainage pressure of the second plumbing equipment is high and the flow rate of drainage is large, the pressure reduction piping reduces the drainage pressure and increases the drainage speed. can be lowered. Therefore, when draining water from the second plumbing device, backflow of the wastewater to the first plumbing device connected upstream from the second plumbing device is suppressed.

In a second aspect, in the drain pipe structure according to the first aspect, the pressure reduction pipe has a bent pipe line.

With this drain pipe structure, pressure loss can be caused in the waste water when the waste water passes through the bent pipe. Therefore, drainage pressure can be reduced.

In a third aspect, in the drain pipe structure according to the first aspect, the pressure reduction piping has a conduit whose inner diameter changes to a small diameter.

With this drain pipe structure, pressure loss can be caused in the waste water when the waste water passes through the pipe line whose inner diameter changes to a small diameter. Therefore, drainage pressure can be reduced.

In a fourth aspect, in the drain pipe structure according to the first aspect, the pressure reduction pipe has a branch pipe line that branches from a pipe line going from upstream to downstream and has a closed end.

In this drainage pipe structure, a part of the drainage water enters the branch pipe and obstructs the flow of the drainage pipe, thereby causing a pressure loss in the drainage water. Therefore, drainage pressure can be reduced.

In a fifth aspect, in the drain pipe structure according to any one of the first to fourth aspects, the drain pipe structure is provided in the second drainage system, and the inlet is provided at a higher position than the outlet, and the drain pipe structure according to any one of the first to fourth aspects is provided. The drainage system has a temporary storage part whose volume per unit length is partially expanded and is formed in a cylindrical shape with the axial direction in the vertical direction, and the inlet is formed into a cylindrical shape with the axial direction in the horizontal direction. The axial center of the inlet is eccentric with respect to the axial center of the temporary storage section, the outlet is formed in a cylindrical shape with the axial direction in the lateral direction, and the axial center of the outlet is eccentric to the axial center of the temporary storage section. , is not eccentric with respect to the axis of the temporary storage section.

In this drainage pipe structure, the inlet of the temporary storage section is formed in a cylindrical shape with the axis in the horizontal direction, and the axis of the inlet is eccentric with respect to the axis of the temporary storage section, so the air in the temporary storage section is This makes it easy for wastewater to be exchanged, allowing wastewater to flow smoothly into the temporary storage area. This suppresses the discharge of air from the temporary storage section. Moreover, this reduces the amount of air flowing into the first plumbing equipment, thereby suppressing the pressure rise on the first plumbing equipment.

In addition, the outlet of the temporary storage section is formed into a cylindrical shape with the axial direction in the horizontal direction, and the axis of the outlet is not eccentric with respect to the axis of the temporary storage section, so that the wastewater that has flowed into the temporary storage section is discharged from the outlet. It becomes easier to gather. Therefore, the drainage water flows smoothly from the outlet.

In a sixth aspect, in the drain pipe structure according to any one of the first to fifth aspects, a pipe line is temporarily disposed between the pressure reduction pipe and the siphon drain pipe in the second drainage system. There is a rising part that goes down and then goes up.

In this drainage pipe structure, the rising part between the pressure reduction pipe and the siphon drain pipe in the second drainage system is filled with waste water, so it is possible to maintain a state of little air in the pipe from the rising part to the siphon drain pipe. can. As a result, the amount of air flowing into the first plumbing device during the next draining from the second plumbing device can be reduced, and an increase in pressure on the first plumbing device can be suppressed.

In a seventh aspect, in the drain pipe structure according to any one of the first to sixth aspects, a first drainage trap is provided in the first drainage system, and the first drainage trap is configured to an inflow section through which the wastewater flows downward; a first downward curved pipe section provided below the inflow section and curved downward from the vertically upper side toward the horizontal direction; A first up-curving pipe section provided on the downstream side of the drainage and curving upward from the horizontal direction to the upper side in the vertical direction; a second up-curving pipe section that curves upward in the direction; and a second down-curving pipe section that is provided on the downstream side of the second up-curving pipe section in the drainage direction and curves downward from the horizontal direction toward the bottom in the vertical direction. It has a pipe part, and a pressure buffer device which is arranged above the second downwardly curved pipe part, communicates with the second downwardly curved pipe part, and buffers the pressure inside the pipe.

In this drain pipe structure, when waste water flows into the inflow section, the waste water flows downstream via the first downward curve pipe section, the first upward curve pipe section, the second upward curve pipe section, and the second downward curve pipe section. The waste water is discharged to the side and accumulates in the curved portion formed by the first downward curved pipe section and the first upward curved pipe section, and the accumulated waste water becomes a water seal.

As an example, if the pressure on the downstream side of the pipe trap momentarily increases above atmospheric pressure, in other words, the pressure momentarily becomes positive, the air on the downstream side of the pipe trap pushes the seal water from the downstream side, causing the seal water to flow in. Try to force the flow back to the side. However, the pressure of the air that pushes the seal water and causes it to flow back toward the inlet side is buffered by a pressure buffer device installed downstream in the drainage direction of the seal water, so the pressure acting on the seal water is Compared to the case without it, it is smaller and breakage of the seal is suppressed.

Here, in the second downwardly curved pipe section of the pipe trap, the waste water flows so as to fall from the upper side to the lower side. Since the pressure buffer device is disposed above the second downwardly curved pipe portion, when wastewater is flowed into the second downwardly curved pipe portion, the wastewater is difficult to flow into the pressure buffer device. Therefore, foreign matter such as dirt in the drainage water becomes difficult to enter the pressure buffer device.

In an eighth aspect, in the drain pipe structure according to the seventh aspect, a ventilation section that can take in air from the outside is provided on the pressure buffer device on the downstream side of the water sealing part of the first drain trap. It is provided.

In this drain pipe structure, the ventilation section is provided downstream of the water sealing part of the first drain trap, so when negative pressure is generated downstream of the first drain trap when siphon force is generated, Outside air can be taken in through the ventilation section. This makes it possible to prevent the seal from breaking in the first drain trap.

In a ninth aspect, in the drain pipe structure according to the seventh aspect or the eighth aspect, a tangent at an upstream end in the drainage direction of the axis of the first upward curved pipe section is with respect to the axis of the inflow section. It has an angle.

In this drainage pipe structure, since the tangent at the upstream end in the drainage direction of the axis of the first up-curving pipe section has an angle with the axis of the inflow section, there is no flow from the inflow section to the first up-curving pipe section. The direction of the flowing wastewater changes suddenly compared to a pipe where the tangent at the upstream end in the drainage direction of the axis in the first upward curved pipe part does not have an angle with the axis of the inflow part. As a result, the flow path resistance increases. This flow path resistance not only acts on the normal flow of wastewater, but also acts when the wastewater flows backward.

According to the present invention, in a drain pipe structure in which a plurality of plumbing devices are connected to one siphon drain pipe, backflow to the upstream plumbing device when water is drained from the plumbing device connected downstream This makes it possible to suppress the pressure rise on the water equipment side.

1 is a sectional view showing a part of a building to which a drain pipe structure according to an embodiment of the present invention is applied. FIG. 2 is a side view showing a pipe trap used in the drain pipe structure of the present invention. Figure 3 is a cross-sectional view along the axis of the tube trap shown in Figure 2; FIG. 3 is a cross-sectional view along the axis of the tube trap. FIG. 3 is a cross-sectional view showing a pressure relief device, a check valve, and a ventilation device. FIG. 2 is a partially cutaway perspective view of the pressure relief device. It is a sectional view showing an elastic expandable body of a pressure relief device. It is a sectional view showing a part of a check valve concerning a modification. It is a sectional view showing the pressure buffer member concerning a modification. It is a sectional view showing a temporary storage part, pressure reduction piping, and a rising part. It is a perspective view showing a temporary storage part. It is a front view showing a temporary storage part. It is a perspective view which shows the modification 1 of pressure reduction piping. It is a longitudinal cross-sectional view which shows the modification 1 of pressure reduction piping. It is a cross-sectional view showing modification example 1 of pressure reduction piping. It is a longitudinal sectional view showing modification example 2 of pressure reduction piping. It is a longitudinal cross-sectional view which shows the modification 3 of pressure reduction piping. FIG. 3 is a cross-sectional view schematically showing the action of the second drainage system in the drainage pipe structure. FIG. 3 is a cross-sectional view schematically showing the effects of a temporary storage section and a rising section. It is a sectional view showing a rectification member concerning a 2nd modification. It is a side view which shows the rectification member based on the 2nd modification. It is a bottom view showing the rectification member concerning the 2nd modification. It is a perspective view showing the pressure relief device concerning the 2nd modification. FIG. 7 is a cross-sectional view taken along an axis showing a pressure relief device according to a second modification. FIG. 3 is a perspective view of the pressure relief device with the cover removed. (A) is a perspective view showing the elastic expansion/contraction body, and (B) is a sectional view along the axis showing the elastic expansion/contraction body (sectional view taken along line 25(B)-25(B) in FIG. 25(B)). be. (A) is a plan view of the elastic expansion/contraction body seen from the axial direction, and (B) is a cross-sectional view perpendicular to the axis of the elastic expansion/contraction body (26(B)-26(B) in FIG. 26(B)). (C) is a sectional view perpendicular to the axis showing the elastic expansion/contraction body in a state where the inside is under negative pressure. FIG. 3 is a perspective view showing a cross section of an elastic expandable body to which a lower support member and an upper support member are attached. It is a perspective view which shows a 1st half member and a 2nd half member. (A) is a perspective view showing the valve body under normal conditions, and (B) is a perspective view showing the valve body floating due to backflowing drainage and blocking the opening of the valve seat.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on drawing. In FIG. 1, a drainage pipe structure 10 according to the present embodiment includes a first drainage system 1, a second drainage system 2, a siphon drainage pipe 30, a pipe trap 24 as a first drainage trap, and a second drainage system 2. It has a primary drainage trap 202 as a second drainage trap, a temporary storage section 204, a pressure reduction pipe 206, and a rising section 208.
The first drainage system 1 is a piping structure that drains waste water from a kitchen sink 16, which is an example of a first plumbing device. Further, the second drainage system 2 is a piping structure through which waste water from a dishwasher 18, which is an example of a second plumbing device, is drained.

As shown in FIG. 1, floor panels 14 are placed on the slab 12 of the dwelling unit at intervals, and on the floor panels 14 are a kitchen sink 16 as a first plumbing device, and a kitchen sink 16 as a first plumbing device. A dishwasher 18 as a second plumbing device is arranged.

A disposer 20 is attached to a drain port 16A of the kitchen sink 16. A pipe 22, a water-seal type pipe trap 24, and a pipe 26 are connected to the downstream side of the disposer 20 in the drainage direction.

A merging joint 28 and a siphon drain pipe 30 are arranged downstream of the pipe 26 in the drainage direction. The siphon drain pipe 30 includes a horizontal pipe 30A having the same inner diameter as the pipe 26, and a vertical pipe 30B.

A horizontal draw pipe 30A of a siphon drain pipe 30 is connected to the downstream end of the pipe 26 in the drainage direction via a merging joint 28. Further, a pipe 210 through which waste water from the dishwasher 18, which will be described later, is discharged is connected to the merging joint 28.

The horizontal pipe 30A is arranged on the slab 12, and the vertical pipe 30B of the siphon drain pipe 30 is a drainage vertical pipe that is suspended through a vertical hole 32 formed in the slab 12 and extends in the vertical direction of the dwelling unit. 34.

(pipe trap)
As shown in FIG. 2, the pipe trap 24 of this embodiment is a so-called water-seal type trap that has a substantially S-shape when viewed from the side. Note that a pressure regulating device 65, which will be described later, is connected to the pipe trap 24 of this embodiment.

As shown in FIG. 3A, the pipe trap 24 of this embodiment includes an inflow side pipe connection part 36 that connects the lower end portion of the pipe 22, a first bent pipe part 38 having a substantially U-shape, and a first bent pipe part 38. A vertical pipe section 40 formed on the downstream side in the drainage direction of the vertical pipe section 40, a second bent pipe section 42 formed on the downstream side in the drainage direction of the vertical pipe section 40 and shaped like an inverted U, and drainage of the second bent pipe section 42. A reduced diameter pipe section 44 is formed on the downstream side in the direction, and a discharge side pipe connection section 46 is formed on the downstream side of the reduced diameter pipe section 44 in the drainage direction and connects the upper end portion of the pipe 26.

The inflow side piping connection part 36 is formed in a cylindrical shape with an axis extending in the vertical direction. The inflow side piping connection part 36 has an inner diameter D1 into which the lower end portion of the piping 22 having a nominal diameter of 30A is inserted, as an example.

A male screw 36A is formed on the outer periphery of the upper end of the inflow side piping connection portion 36, and a female screw 48A of an annular nut 48 that fixes the piping 22 is screwed into this male screw 36A.

A stepped portion 36B is formed in the inflow side piping connection portion 36 at the end portion on the downstream side in the drainage direction. The lower end portion of the pipe 22 inserted into the inflow side pipe connection portion 36 abuts against this stepped portion 50 .

The inner diameter of the first bent pipe portion 38 gradually decreases toward the downstream side in the drainage direction, and the inner diameter D2 at the end on the drainage inflow side is the same as the inner diameter of the pipe 22 (for example, φ30 mm), The inner diameter D3 at the end on the drainage side is, for example, φ25 mm.

In addition, in the first bent pipe part 38, a part that curves downward from the upper direction to the horizontal direction on the upstream side in the drainage direction is a first downward curved pipe part 38A, and a part that curves downward from the horizontal direction to the upper direction on the downstream side in the drainage direction. The curved portion is a first upward curved pipe portion 38B.

Here, the tangent L1 at the upstream end in the drainage direction of the axis 38CL of the first bent pipe section 38 is the axis 36CL of the inflow side piping connection section 36 (the axis 22CL of the piping 22 inserted into the inflow side piping connection section 36). coaxial), and intersects at an angle θ1.
Therefore, compared to the case where the pipes do not intersect at the angle θ1, the drainage water flowing from the inflow side pipe connection portion 36 (piping 22) to the first bent pipe portion 38 is subjected to resistance.
In other words, even when the gas tries to flow from the first bent pipe section 38 to the inflow side piping connection section 36 (piping 22), the gas encounters resistance. Here, although it is explained that "drainage is subject to resistance," this explanation is based on a comparison with the case where they have an angle θ1 and do not intersect. It won't happen.

When the radius of curvature of the axis 38ACL of the first downwardly curved tube section 38A is R1, and the radius of curvature of the axis of the first upwardly curved tube section 38B is R2, R1>R2. The radius of curvature R1 and the radius of curvature R2 are each a single radius of curvature.
Further, the upstream end in the drainage direction (portion indicated by the inner diameter D2) of the first bent pipe portion 38 is located at a lower position than the downstream end in the drainage direction (portion indicated by the inner diameter D3).

A cylindrical cleaning port 52 is provided at the lower end of the first bent tube portion 38 . A male screw 52A is formed on the outer periphery of the cleaning port 52, and by screwing and tightening the female screw 54A of the cap 54 onto the male screw 52A, the cap 54 is attached to the cleaning port 52. is blocked. In the present embodiment, the cleaning port 52 is provided at the lower end of the first bent tube portion 38, but the cleaning port 52 may be provided as needed and may not be provided.

The vertical pipe section 40 disposed on the downstream side in the drainage direction of the first upward curved pipe section 38B has a cylindrical shape, and the axis 40CL is in the vertical direction. The inner diameter D4 of this vertical pipe portion 40 is the same inner diameter (φ25 mm) as the inner diameter D3 at the end of the first bent pipe portion 38 on the drainage side.

Note that the axis 40CL of the vertical pipe section 40 and the tangent L2 at the downstream end in the drainage direction of the axis 38CL of the first upward curved pipe section 38B coaxially match.

The second bent pipe part 42 disposed on the downstream side of the vertical pipe part 40 in the drainage direction has an inner diameter that gradually decreases toward the downstream side in the drainage direction.

In the second bent pipe section 42, a portion that curves upward from below to the horizontal direction on the upstream side in the drainage direction is a second upward curved pipe section 42A, and curves downward from the horizontal direction to the downward direction on the downstream side in the drainage direction. This portion is a second downwardly curved pipe portion 42B.

The inner diameter D5 of the end of the second bent pipe part 42 on the waste water inflow side (the connection part with the vertical pipe part 40) is the same as the inner diameter D4 of the vertical pipe part 40, and the end part of the second bent pipe part 42 on the waste water discharge side The inner diameter D6 of the end portion (the connection portion with the reduced diameter tube portion 44) is, for example, φ20 mm.

The radius of curvature of the axis 42CL of the second bent tube portion 42 is R3. The tangent L3 of the axis 42CL of the second bent pipe section 42 at the upstream end in the drainage direction and the axis 40CL of the vertical pipe section 40 coaxially coincide (overlap) without forming an angle.

A cylindrical pressure relief device attachment part 56 that extends vertically upward and opens upward is integrally formed in the middle part of the second downwardly curved pipe part 42B in the drainage direction. A male screw 56A is formed on the outer periphery of the pressure relief device mounting portion 56, and an annular screw 56A is formed on the outer periphery of the pressure relief device mounting portion 56. The female thread 57A of the nut 57 is screwed together.

A rectifying member 58 is inserted into the pressure relief device mounting portion 56 . The flow regulating member 58 includes a cylindrical portion 58A that is inserted into the pressure relief device attachment portion 56, and a fin 58B is integrally formed at the lower end of the cylindrical portion 58A. The fins 58B protrude into the second downwardly curved pipe section 42B and are inclined with respect to the vertical direction so as to guide the direction of drainage flowing from the upstream side toward the diameter-reduced pipe section 44 side. In other words, the fins 58B make it difficult for the waste water flowing from the upstream side to flow into the pressure relief device 66 side, which will be described later.

The reduced diameter pipe part 44 provided on the downstream side in the drainage direction of the second downward curved pipe part 42B has a cylindrical shape whose inner diameter gradually decreases toward the downstream side in the drainage direction, and the axis 44CL is aligned with the vertical direction. has been done. The inner diameter of the wastewater inflow side end of the reduced diameter pipe section 44 (the connection part with the second downwardly curved pipe section 42B) is the same inner diameter as the inner diameter D6 of the downstream end in the drainage direction of the second downwardly curved pipe section 42B. be. On the other hand, the inner diameter D7 of the waste water discharge side end of the reduced diameter pipe portion 44 is, for example, φ16 mm.

Note that the tangent L4 of the axis 42CL of the second bent tube section 42 at the downstream end in the drainage direction and the axis 44CL of the reduced diameter tube section 44 coaxially coincide (overlap) without forming an angle.

It is provided coaxially with the cylindrical diameter-reduced pipe part 44 on the downstream side of the diameter-reduced pipe part 44 in the drainage direction. In addition, the discharge side piping connection part 46 is formed with a stepped part 47 whose diameter is reduced toward the diameter-reduced pipe part 44 at the end portion on the upstream side in the drainage direction. The upper end portion of the pipe 26 inserted into the discharge side pipe connection portion 46 abuts against this stepped portion 47 .

A male screw 46A is formed on the outer periphery of the lower end side of the discharge side piping connection part 46, and a female screw 64A of an annular nut 64 that fixes the piping 26 is screwed into this male screw 46A. In addition, the discharge side piping connection part 46 of this embodiment has an inner diameter D8 into which the piping 26 with a nominal diameter of 20A can be inserted, as an example.

In this pipe trap 24, a part of the waste water discharged from the kitchen sink 16 is stored as sealed water in the inflow side pipe connection part 36, the first bent pipe part 38, the vertical pipe part 40, and the second bent pipe part 42. be done. Note that the two-dot chain line indicated by the symbol Ws in FIG. 3A represents the water surface of the normal water seal.

Note that the height of the liquid level Ws of the sealed water stored in the pipe trap 24 under normal conditions coincides with the height position of the uppermost end Pt of the inner channel wall surface on the inside of the bending radius in the second bending pipe section 42. ing. If the liquid level Ws of the wastewater rises above the top end Pt, the wastewater flows downstream in the drainage direction beyond the top end Pt, and eventually the liquid level Ws rises above the top end Pt. match the position.

In addition, as shown in FIG. 3B, in the pipe trap 24 of this embodiment, the sealing depth h is the maximum of the inner circumferential surface 38UF on the upper side of the pipe of the first bent pipe portion 38, which is approximately U-shaped. It refers to the dimension measured in the vertical direction from the lower end Pu to the uppermost end Pt of the internal channel wall surface on the inside of the bending radius in the second bent pipe section 42. Note that the water sealing depth h has a dimension (as an example, 50 mm or more) determined by a standard (as an example, technical standards for drainage equipment) in order to suppress breakage of the pipe trap 24.

In the pipe trap 24, the height position of the end on the drainage inflow side, that is, the upper end 36T on the upstream side in the drainage direction of the inflow side piping connection part 36, is the lowest end in the pipe inside the first bent pipe part 38. It is preferable to provide it between Pb and the uppermost end Pt of the second bent tube part 42. In this embodiment, the height position of the upper end part 36T of the inflow side pipe connection part 36 is at the same height as the height position of the uppermost end part Pt of the second bent pipe part 42.

(Pressure adjustment device)
The pressure regulator 65 of this embodiment includes a pressure relief device 66, a check valve 90, and a vent valve 110. As shown in FIGS. 4 and 5, the pressure relief device 66 attached to the pressure relief device attachment portion 56 includes a thin elastic expandable body 68 made of an elastic material such as rubber, and a lower end side of the elastic expandable body 68. The upper support member 72 supports the upper end of the elastic expansion/contraction body 68, and a cover 74.

The elastic expansion/contraction body 68 includes a cylindrical expansion/contraction portion 68A whose cross-sectional shape in a free state is approximately cross-shaped as shown in FIG. An annular base 68B extending radially outward is integrally formed at both axial ends of the expandable/contractable part 68A, and an elastic expandable body 68 is attached to a lower support member 70 and a lower support member 70 on the outer circumference of the base 68B. An annular attachment portion 68C for attachment to the upper support member 72 is integrally formed. Note that a thick rib 68D is formed at the end of the attachment portion 68C.

As shown in FIGS. 4 and 5, the lower mounting portion 68C of the elastic expansion/contraction body 68 is clamped and fixed between the lower support member 70 and the cover 74, and the rib 68D is connected to the lower support member 68. It is inserted into an annular groove 78 formed on the outer periphery of 70.

Further, the upper mounting portion 68C of the elastic expansion/contraction body 68 is sandwiched and fixed between the upper support member 72 and the cover 74, and the rib 68D is inserted into an annular groove 78 formed on the outer periphery of the upper support member 72. Ru.

A tapered through hole 80 is formed in the center of the lower support member 70, and an insertion tube portion 82 communicating with the through hole 80 projects downward at the center of the lower surface. As shown in FIG. 3A, this insertion tube portion 82 is inserted into the pressure relief device attachment portion 56 of the tube trap 24, and the pressure relief device 66 is attached to the tube trap 24.

As shown in FIG. 4, a tapered through hole 84 is formed in the center of the upper support member 72, and a cylindrical check valve mounting portion 86 that communicates with the through hole 84 is directed upward in the center of the upper surface. It stands out. A male screw 86A is formed on the outer periphery of the check valve mounting portion 86.

(non-return valve)
As shown in FIG. 4, a check valve 90 is attached to the check valve attachment portion 86 of the pressure relief device 66.
The check valve 90 includes a cylindrical main body 92, a spherical valve body 94, a cap 96, and the like. A female screw 92A is formed on the inner periphery of the lower part of the main body 92, and by screwing and tightening the male screw 86A of the check valve attachment part 86 of the pressure relief device attachment part 56 to this female screw 92A, a reverse A stop valve 90 is attached to pressure relief device 66 .

A partition wall 98 is formed inside the main body 92 to vertically divide the inside, and a dome-shaped valve support portion 100 that is convex upward is integrally formed in the center of the partition wall 98. The valve body support portion 100 prevents the valve body 94 from moving downward so that the valve body 94 does not fall into the pressure relief device 66 below.

A plurality of through holes 102 are formed in the partition wall 98 on the radially outer side of the valve body support portion 100 . The through hole 102 communicates the space above and below the partition wall 98, allowing drainage and air to pass therethrough.

The spherical valve body 94 has a specific gravity set so that it floats on the waste water when the waste water flows into the space above the partition wall 98 through the through hole 102 .

The cap 96 is formed with a female screw 96A into which a male screw 92B formed on the outer periphery of the upper part of the main body 92 is screwed. By screwing the female screw 96A into the male screw 92B and tightening, the cap 96 is tightened. It is attached to the main body 92.

A valve seat 104 is provided on the cap 96, and a valve hole 106 is formed in the center of the valve seat 104. This valve hole 106 is closed with a valve body 94 floating in the drainage water. Therefore, even if drainage water enters the inside of the pressure relief device 66, the drainage water is prevented from flowing out above the check valve 90. Note that the check valve 90 may be provided as needed, and may not be provided.

A vent valve 110 is attached to the upper part of the check valve 90. The vent valve 110 of this embodiment is attached to a drain trap or drain pipe and has a common structure, so a description regarding the structure will be omitted. Note that the vent valve 110 takes in outside air when the downstream side in the drainage direction becomes negative pressure, and breaks the seal of the pipe trap 24 (the accumulated sealed water is sucked downstream in the drainage direction and disappears due to the negative pressure). can be suppressed.
The vent valve 110 protects the water seal of the pipe trap 24 by sucking in the atmosphere during drainage, and closes during normal times to prevent leakage of bad odors. As the vent valve 110, a known one (for example, one described in Japanese Patent Application Laid-open No. 2009-299866) can be used.
Note that "negative pressure" means that the pressure is lower than the outside air in the environment in which the drain pipe structure 10 is placed.

(First modification of pressure relief device)
FIG. 7 shows a pressure relief device 120 having a different structure from the pressure relief device 66 shown in FIG. The pressure relief device 120 shown in FIG. 7 basically has the same configuration as the pressure relief device 66 shown in FIG. 4, but some shapes and parts are different. Note that even if the shapes are different, the same components are designated by the same reference numerals, and the explanation thereof will be omitted.

The elastic expansion/contraction body 68 of the pressure relief device 120 of this embodiment has a cylindrical shape in the free state shown by the two-dot chain line, and when the internal pressure increases, it elastically deforms outward in the radial direction as shown by the solid line. It can bulge and buffer pressure.

The attachment portion 68C of the elastic expansion/contraction body 68 is fixed by a ring 122 disposed on the outer circumferential side. Further, an upper support member 72 that supports the upper end of the elastic expandable body 68 and a lower support member 70 that supports the lower end of the elastic expandable body 68 are connected by a cylindrical support member 124. Note that the support member 124 is configured to be able to be divided into two in the radial direction, and is connected by a hinge (not shown) so that it can be opened and closed.

(First modification of check valve)
Note that in the check valve 90 shown in FIG. 4 and the check valve 90 shown in FIG. It may be a cylindrical valve body 112 having a small diameter portion 112B that enters the valve hole 106, and its shape is not limited. By adopting such a shape, water can be stopped at the upper surface of the large diameter portion 112A, and water is not stopped at a point like a sphere, so that the water stopping function is improved.

(Second drainage system)
In FIG. 1, the second drainage system 2 is a piping structure through which wastewater from a dishwasher 18, which is an example of a second plumbing device, flows. A pressure pump (not shown) is built into the drain section of the dishwasher 18, and the pressure pump is used to flush out waste water. The dishwasher 18 or the second drainage system 2 is provided with a primary drainage trap 202 as a second drainage trap. The second drainage system 2 is provided with, for example, a secondary drainage trap 203 as a third drainage trap, a temporary storage section 204, a pressure reduction pipe 206, and a rising section 208. In FIG. 1, a primary drain trap 202 is built into the dishwasher 18. Note that the primary drain trap 202 may be provided in the drain system 2 separately from the second dishwasher 18. In this case, the secondary drainage trap 203 may also serve as the primary drainage trap 202.

The second drainage system 2 is connected to the downstream side of the first drainage system 1 in the horizontal draw pipe 30A of the siphon drainage pipe 30. Specifically, a merging joint 28 is provided downstream of the first drainage system 1 in the horizontal pipe 30A, and the pipe 210 downstream of the rising portion 208 in the second drainage system is connected to the merging joint 28. It is connected to the.

The secondary drainage trap 203 is, for example, a U-shaped pipe trap that is curved convexly downward and is provided between the primary drainage trap 202 and the temporary storage section in the second drainage system 2 . A pipe 212 on the downstream side of the secondary drainage trap 203 extends upward and then laterally, and is connected to the inlet 204A of the temporary storage section 204.

(Temporary storage section)
In FIG. 9, the temporary storage section 204 is provided in the second drainage system 2, and the inlet 204A is provided at a higher position than the outlet 204B, so that the volume per unit length in the second drainage system 2 is partially It has been expanded. In other words, the temporary storage section 204 is a chamber that can temporarily store waste water. The temporary storage portion 204 is formed, for example, in a cylindrical shape (for example, a cylindrical shape or a rectangular cylindrical shape) with the vertical direction as the axial direction. Specifically, the temporary storage section 204 includes a cylindrical main body 214, an upper body 216, and a lower body 218. The upper body 216 has large diameter portions 216A and 216B at its upper end and lower end, respectively. The inner diameter of the main body portion 214 is set larger than the inner diameter of the pipe 212. For example, a lid member 220 is removably fitted into the large diameter portion 216A at the upper end. In FIG. 10, the lid member 220 (FIG. 9) has been removed. By removing the lid member 220 in this manner, an opening 216D is formed in the large diameter portion 216A. This opening can be used as a cleaning port. Note that the lid member 220 may not be provided and the upper end of the upper body 216 (temporary storage section 204) may be closed.

For example, the upper end of the main body portion 214 is fitted into the large diameter portion 216B at the lower end. A small diameter portion 216C is provided between the large diameter portions 216A and 216B. The entrance 204A of the temporary storage section 204 is provided in the small diameter section 216C. As shown in FIG. 11, the axial direction of the inlet 204A is the horizontal direction, and the axial center X1 of the inlet 204A is eccentric with respect to the axial center Z of the temporary storage section 204.

The upper end of the lower body 218 is provided with a large diameter portion 218A. For example, the lower end of the main body portion 214 is fitted into the large diameter portion 218A. The outlet 204B of the temporary storage section 204 is provided at the lower end of the lower body 218, and the horizontal direction is the axial direction. As shown in FIG. 11, the axis X2 of the outlet 204B is not eccentric with respect to the axis Z of the temporary storage section 204.

As shown in FIG. 9, in the temporary storage section 204, an inner surface 218B on the opposite side to the outlet 204B in the axial direction of the outlet 204B allows the drainage to flow toward the outlet 204B side when the wastewater is discharged from the temporary storage section 204. It's curved towards you. In other words, the lateral distance between the inner surface 218B and the outlet 204B decreases downward. As long as the inner surface 218B has a similar configuration, the inner surface 218B may be a slope, a combination of a slope and a curved surface, or the like.

(Pressure reduction piping)
In FIG. 9, a pressure reduction pipe 206 is provided between the temporary storage section 204 and the rising section 208 in the second drainage system 2. This pressure reduction pipe 206 is a pipe for reducing the drainage pressure in the second drainage system 2. In the example shown in FIG. 9, the pressure reduction piping 206 has a bent pipe line. This conduit is formed in a wave shape having an amplitude in the radial direction of the temporary storage section 204, and has, for example, two folded portions 206A and 206B. As a result, the flow direction of the drainage water is reversed in the folded portions 206A and 206B.

The configuration of the pressure reduction pipe 206 is not limited to this, and may be the configuration shown in FIGS. 12 to 16. In a modified example shown in FIGS. 12 to 14, an inlet 222 and an outlet 224 are provided in the vertical direction, and a spiral portion 226 is provided between the inlet 222 and the outlet 224. The inlet 222 opens at the center end of the spiral 226 , and the outlet 224 opens at the outer end of the spiral 226 . The flow direction of the waste water bends at a substantially right angle, for example, from the vertical direction to the lateral direction when it enters the vortex 226 from the inlet 222 (bending portion 226A in FIG. 13). Thereafter, it is reversed at the folding portion 226B while remaining in the horizontal direction, and bent at approximately right angles at the bending portions 226C and 226D. Then, at the point where it exits from the spiral portion 226 to the outlet 224, it bends from the lateral direction to the vertical direction at a substantially right angle (curved portion 226E in FIG. 14).

In Modification 2 shown in FIG. 15, the pressure reduction pipe 206 has a pipe line whose inner diameter changes to a small diameter, and whose inner diameter changes periodically. Specifically, the pressure reduction pipe 206 is formed into a cylindrical shape that extends linearly, for example. On the inner surface of the pressure reduction pipe 206, large diameter portions 228 and small diameter portions 230 are formed alternately in the axial direction. The boundary between the large diameter portion 228 and the small diameter portion 230 is, for example, a step orthogonal to the axial direction. Both ends of the pressure reduction pipe 206 are, for example, large diameter portions 228, one of which is an inlet 232 and the other is an outlet 234. In modification 3 shown in FIG. 16, the pressure reduction pipe 206 has a branch pipe line 236. The branch pipe line 236 branches from the pipe line going from upstream (inlet 238) to downstream (outlet 240), and is closed at the end. In this example, the conduit is bent at a substantially right angle toward the inlet 238 and the outlet 240, and a branch conduit 236 is provided on the extension from the inlet 238 at the bend. The length of the branch pipe line 236 is, for example, equal to or less than the inner diameter of the pipe line. Once the wastewater enters the branch pipe line 236 and obstructs the flow of the wastewater, a pressure loss occurs in the wastewater.
Although not shown, the pressure reduction piping may have a configuration in which the inner diameter of the pipe line gradually increases from the inlet to the outlet. Furthermore, although not shown in the drawings, the tube may include a plurality of locations where the inner diameter of the tube once expands and then decreases to return to the normal inner diameter. In other words, the inner wall of the conduit may be formed in a zigzag shape with respect to its axial direction. The range of the angle between the inner wall and the axial direction is, for example, 30 to 40 degrees, preferably 33 to 36 degrees.

Note that the configuration of the pressure reduction pipe 206 is not limited to these, and may be any configuration that causes a pressure loss in the waste water flowing through the pressure reduction pipe 206. For example, protrusions may be provided on the inner surface of the conduit to generate turbulent flow.

(rising part)
In FIG. 9, the rising portion 208 is a portion that is provided between the temporary storage portion 204 and the siphon drain pipe 30 (FIGS. 1, 17, and 18) in the second drainage system 2, and is once lowered and then raised. be. The rising portion 208 may have any structure as long as it can store sealed water, such as a U-shaped or S-shaped pipe trap. As an example, the rising portion 208 includes a descending portion 208A, a bottom portion 208B, a rising portion 208C, and a top portion 208D.

The descending portion 208A is connected to the downstream side of the temporary storage portion 204, and is a portion where the conduit proceeds downward. In this embodiment, the pressure reduction pipe 206 is connected to the downstream side of the temporary storage section 204, and the outlet 206C at the lower end of the pressure reduction pipe 206 is connected to the lowered part 208A. On the downstream side of the temporary storage section 204, the pressure reduction piping 206 also extends downward, so it can be considered that a part of the pressure reduction piping 206 also serves as the descending portion 208A. When the pressure reduction pipe 206 is omitted, a portion extending downward from the outlet 204B of the temporary storage portion 204 constitutes a descending portion 208A (FIGS. 17 and 18).

The lowest portion 208B is at the lowest position of the rising portions 208. The top portion 208D is, for example, a horizontal portion, but as shown in FIGS. 17 and 18, it may not be horizontal. The rising portion 208C is a portion that extends linearly, for example, obliquely upward from the downstream end of the lowermost portion 208B. The shape of the rising portion 208C is not limited to a linear shape, but may be curved. The uppermost portion 208D is a portion that extends, for example, in the horizontal direction from the upper end of the rising portion 208C, and is located at the highest position in the rising portion 208. The top portion 208D does not necessarily have to have a horizontal portion, and the top portion 208D may be directly connected to the pipe 210 by omitting the horizontal portion. The pipe 210 is the pipe 210 on the downstream side of the rising portion 208, and extends downward and is connected to the horizontal draw pipe 30A (siphon drain pipe 30) (FIGS. 1 and 17).

The top 208D of the rising portion 208 may be set at a position higher than the height of the outlet 204B of the temporary storage portion 204. Line L in FIG. 9 indicates the height position of the bottom of the outlet 204B of the temporary storage section 204. In this example, the height position of the inner ceiling portion 208E at the top 208D is set to a position equal to or higher than the height of the line L. The position above the height of the line L is a position at a height equal to the height of the line L, or a position at a height higher than the height of the line L.

Note that increasing the height of the top 208D increases the amount of wastewater 242 stored in the temporary storage section 204, and lowering the height of the top 208D increases the amount of wastewater 242 stored in the temporary storage 204. Quantity decreases. In the example shown in FIG. 17, the top 208D of the rising portion 208 is set at a lower position than the height of the outlet 204B of the temporary storage portion 204. If the height position of the top part 208D is too low, the waste water 242 in the temporary storage part 204 will flow out, so the height position of the top part 208D should be set within the limit where the waste water 242 can be stored in the temporary storage part 204. It can be changed arbitrarily.

(action, effect)
Next, the functions and effects of the drain pipe structure 10 of this embodiment will be explained.
When waste water is discharged from the kitchen sink 16 through use of the kitchen sink 16, the waste water passes through the disposer 20, the pipe 22, the pipe trap 24, and then reaches the pipe 26.

Thereafter, the waste water flows through the horizontal pipe 30A and the vertical pipe 30B of the siphon drain pipe 30, and when the waste water in the vertical pipe 30B falls due to gravity while a part of the vertical pipe 30B is filled with waste water, the water flows into the vertical pipe 30A and the vertical pipe 30B. A siphon force corresponding to the water head difference in the vertical pipe 30B is generated inside the pipe 30B.

The waste water in the horizontal draw pipe 30A is sucked toward the vertical pipe 30B by the siphon force, and the inside of the horizontal draw pipe 30A and the vertical pipe 30B are filled with waste water, resulting in a full flow, increasing the flow velocity and moving towards the horizontal draw pipe 30A. , and the vertical pipe 30B, and the waste water from the kitchen sink 16 is discharged to the drain pipe 34.

On the other hand, when waste water is discharged from the dishwasher 18, the waste water pushes the air inside the piping 210 downstream in the drainage direction, so the air inside the horizontal drawing pipe 30A and the piping are pushed, and the horizontal drawing pipe 30A At the same time that the inside of the pipe becomes positive pressure, the positive pressure also acts on the pipe trap 24 side via the pipe 26.
Note that "positive pressure" means that the pressure is higher than the outside air in the environment in which the drain pipe structure 10 is placed.

Here, when waste water is momentarily discharged from the dishwasher 18, a large positive pressure may temporarily act on the horizontal draw pipe 30A and the piping 26, and this causes the sealed water to flow to the kitchen sink 16 side. There is a risk that the pipe trap 24 may be sealed due to backflow. Furthermore, when a large amount of wastewater is momentarily discharged from the dishwasher 18, the wastewater discharged from the dishwasher 18 may flow back toward the pipe trap 24 and overflow the pipe trap 24. In this embodiment, it is possible to prevent the water seal of the pipe trap 24 from being broken and the drainage discharged from the dishwasher 18 from overflowing the pipe trap 24 in the following manner.

(1) When waste water is instantaneously discharged from the dishwasher 18 and the positive pressure inside the piping 26 increases instantaneously, the inside of the piping 26 becomes positive pressure, and the air inside the piping 26 flows back inside the pipe trap 24. However, the pressure relief device 66 provided on the upstream side in the drainage direction of the seal water buffers the positive pressure, thereby suppressing the breakage of the seal water (in this case, the breakage of the seal due to backflow of air). Ru.

(2) Next, a comparison will be made between the pipe trap 24 of this embodiment and a pipe trap of a conventional structure, and an explanation will be given of how it is difficult for the waste water that flows back from the dishwasher 18 to overflow through the pipe trap 24 of this embodiment.
As shown in FIG. 3B, in the conventional pipe trap, the side view shape of the portion corresponding to the first bent pipe portion 38 of the present embodiment is circular with a single radius of curvature; The pipe upper side inner circumferential surface corresponding to the pipe upper inner circumferential surface 38UF has an arc shape that is part of a virtual circle indicated by a two-dot chain line FC1. Note that the diameter of the virtual circle indicated by the two-dot chain line FC1 is the length of the straight line connecting P1 and P2.

For example, the water sealing depth h has a dimension determined by standards, etc., so the position of the water level on the downstream side of the sealing water in a conventional pipe trap is on the arc-shaped pipe shown by the two-dot chain line FC. It is located at a height h upward from the lowest end P'u of the side inner circumferential surface.

That is, the uppermost end P't of the conventional pipe trap, which corresponds to the uppermost end Pt of the pipe trap 24 of this embodiment, is at a position lower than the uppermost end Pt of the pipe trap 24 of this embodiment by α. .

Therefore, when the pipe trap 24 of this embodiment is installed at the same height as the conventional pipe trap, the water sealing water surface Ws is set at a position higher than the water sealing water surface of the conventional pipe trap by α. can be placed in

As a result, in the pipe trap 24 of the present embodiment, the drainage water discharged from the dishwasher 18 on the downstream side and rising, that is, the drainage water flowing backward, becomes difficult to reach the sealed water stored in the pipe trap 24, and the pipe trap 24 is suppressed from overflowing the water seal.

(3) If the downstream side of the pipe trap 24 in the water sealing direction becomes negative pressure, the second downwardly curved pipe section 42B of the pipe trap 24 is released via the vent valve 110 and the pressure relief device 66. Outside air is introduced into the seal, the negative pressure acting on the water seal is reduced, and breakage of the seal due to negative pressure can be suppressed.

(4) In the pipe trap 24 of this embodiment, since the horizontal distance Lb is set smaller than the horizontal distance La, compared to the case where the horizontal distance La and the horizontal distance Lb are the same, Drainage will flow more easily.

(5) Note that when waste water is discharged from the kitchen sink 16, the waste water flows through the disposer 20, the piping 22, and the pipe trap 24 in this order. When the waste water flows through the second bent pipe part 42 of the pipe trap 24, the waste water is guided toward the diameter-reduced pipe part 44 by the fins 58B protruding into the second downwardly curved pipe part 42B. The waste water discharged from the pressure relief device 66 is difficult to enter.

(6) When draining from the dishwasher 18, the waste water flows into the siphon drain pipe 30 through the primary drain trap 202, the temporary storage section 204, and the rising section 208. When the inside of the siphon drain pipe 30 becomes full and a siphon force is generated, waste water is sucked downstream. Since the second drainage system 2 is provided with a temporary storage section 204, even if the drainage pressure of the dishwasher 18 is high and the flow rate of the drainage water is large, the temporary storage section 204 receives the drainage water and reduces the drainage pressure. can be released. Therefore, when draining water from the dishwasher 18, backflow of the waste water to the first plumbing device connected upstream from the dishwasher 18 is suppressed.

Furthermore, since the inlet 204A of the temporary storage section 204 has the lateral direction as the axial direction, and the axis X1 of the inlet 204A is eccentric with respect to the axis Z of the temporary storage section 204 (FIG. 11), the inside of the temporary storage section 204 The exchange of air and waste water 242 is likely to occur. Specifically, the waste water 242 flows downward along the inner wall of the temporary storage section 204, so that the waste water 242 is less susceptible to air resistance when flowing in. Therefore, the waste water 242 smoothly flows into the temporary storage section 204. This suppresses the discharge of air from the temporary storage section 204. Moreover, this reduces the amount of air flowing into the first plumbing equipment, thereby suppressing the pressure rise on the first plumbing equipment.

Further, since the outlet 204B of the temporary storage section 204 has the horizontal direction as the axial direction, and the axis X2 of the outlet 204B is not eccentric with respect to the axis Z of the temporary storage section 204 (FIG. 11), the temporary storage section 204 The inflowing waste water 242 is more likely to collect at the outlet 204B. Further, in the temporary storage section 204, the inner surface of the outlet 204B on the opposite side to the outlet 204B in the axial direction is curved so that the waste water 242 is directed toward the outlet 204B when the waste water 242 is discharged from the temporary storage section 204. Therefore, the waste water 242 flowing down along the inner surface on the opposite side to the outlet 204B tends to collect at the outlet 204B. Therefore, the drainage water 242 flows out smoothly from the outlet 204B.

In FIGS. 17 and 18, when the generation of the siphon force is finished, air remains in the upstream part of the temporary storage section 204 from the primary drainage trap 202 in the second drainage system 2, and air remains inside the temporary storage section 204. The drainage water 242 remains from the downstream side to the rising portion 208. Specifically, a water seal having a water seal height H1 is formed in the rising portion 208 on the downstream side of the temporary storage portion 204. On the other hand, since the upstream side of the temporary storage section 204 in the second drainage system 2 is blocked by the primary drainage trap 202, the waste water 242 remaining in the temporary storage section 204 moves downstream (the water level decreases). Accordingly, the air remaining in the temporary storage section 204 from the primary drainage trap 202 expands. Therefore, the head pressure H2 of the waste water 242 remaining in the temporary storage section 204 (the force that causes the waste water to move toward the downstream side), and the negative pressure ( The water level in the temporary storage section 204 is lowered to a position where the force that prevents the movement of wastewater downstream) is balanced. In other words, the water level in the temporary storage section 204 will drop to a position where the waste water will no longer be able to get over the top 208D of the rising section 208 due to the negative pressure caused by the expansion of the air described above. In other words, the temporary storage section 204 stores the waste water 242 at that water level.

Further, since the secondary drainage trap 203 is provided separately from the primary drainage trap 202, a blockage state in the pipe upstream of the temporary storage section 204 is likely to occur. Thereby, negative pressure for storing wastewater in the temporary storage section 204 can be stably generated within the pipe.

As a result, the pipe line from a part of the temporary storage part 204 to the rising part 208 is filled with the waste water 242, so that a state in which there is little air can be maintained in the pipe line from the rising part 208 to the siphon drain pipe 30. Moreover, this reduces the amount of air that flows into the first plumbing device when draining water from the dishwasher 18 next time, thereby suppressing the pressure rise in the first plumbing device. Further, since the water level of the waste water 242 that collects in the temporary storage section 204 is kept constant and does not repeat wetting and drying, it is difficult for dirt to accumulate in the temporary storage section 204.

Further, since the temporary storage section 204 is a part of the second drainage system 2 in which the volume per unit length is partially expanded, the inside of the temporary storage section 204 will not become dense with the waste water 242. Therefore, the siphon force hardly affects the water seal of the primary drain trap 202 and the water seal of the secondary drain trap 203, which almost reaches the upstream side (dishwasher 18 side) of the temporary storage section 204.

Furthermore, since the top 208D of the rising section 208 is set at a position higher than the height of the outlet 204B of the temporary storage section 204, it becomes easier to fill the area from the temporary storage section 204 to the rising section 208 with waste water.

Furthermore, since the second drainage system 2 is provided with the pressure reduction piping 206, even if the drainage pressure of the dishwasher 18 is high and the flow rate of the drainage water 242 is large, the pressure reduction piping 206 reduces the drainage pressure. Drainage speed can be reduced. Therefore, when draining water from the dishwasher 18, backflow of the waste water 242 toward the first plumbing device connected upstream from the dishwasher 18 is suppressed.

In the pressure reduction piping 206 according to the first modification shown in FIGS. 9, 13, and 14, pressure loss can be caused in the waste water when the waste water passes through the bent pipe line. In the pressure reduction piping 206 according to Modification 2 in FIG. 15, pressure loss can be caused in the waste water 242 when the waste water 242 passes through the pipe line whose inner diameter changes to a small diameter. Therefore, drainage pressure can be reduced. In the pressure reduction piping 206 according to Modification 3 in FIG. 16, part of the drainage water enters the branch pipe line 236, thereby causing a pressure loss in the drainage water. Therefore, drainage pressure can be reduced. In this way, the various pressure reduction pipes 206 can reduce the drainage pressure.

As described above, according to the present embodiment, in a drain pipe structure in which a plurality of plumbing devices are connected to one siphon drain pipe 30, water on the upstream side is It is possible to suppress backflow to the surrounding equipment side and pressure rise on the water surrounding equipment side.

[Second modification example of rectifying member and second modification example of pressure relief device]
Next, a second modification of the pressure relief device 66 and a second modification of the rectifying member 58 described in the above embodiment will be described with reference to FIGS. 19 to 21.

(Second modification of rectifying member)
A flow regulating member 300 according to a second modification shown in FIGS. 19 to 21 is entirely formed of an elastic body such as rubber or synthetic resin, and is elastically deformable. The flow regulating member 300 includes a cylindrical portion 300A that is inserted into the pressure relief device attachment portion 56.

A flange 300C is formed at the upper end of the cylindrical portion 300A. The flange 300C is held between the lower end of the insertion tube section 82 of the pressure relief device 66 and the step formed on the inner peripheral surface of the pressure relief device attachment section 56, so that the flow rectifying member 300 is attached to the pressure relief device attachment section 56. is fixed.

As shown in FIGS. 19 and 20, an opening 302 that is inclined with respect to the axis of the cylindrical portion 300A is formed at the lower end of the cylindrical portion 300A. The opening 302 is inclined so that the upstream side in the drainage direction is higher than the downstream side in the drainage direction. Therefore, the opening 302 has a substantially elliptical shape (not shown) when viewed from the front.

One end of a fin 300B that serves as a valve body for opening and closing the opening 302 is integrally connected to the upper end side of the opening 302. A connecting portion 304 between one end portion of the fin 300B and the opening 302 serves as a hinge, and the fin 300B swings about this connecting portion 304 as a fulcrum (in the direction of arrow A in FIG. 19 and in the direction of arrow A). the opening 302 can be opened and closed in the opposite direction). Note that the fin 300B has a substantially elliptical shape similar to the opening 302 in order to close the opening 302.

As shown in FIG. 19, the fins 300B in a normal state (in a free state where drainage water is not flowing) protrude into the second downwardly curved pipe portion 42B. More specifically, when the imaginary line FL connected to the inner peripheral surface of the second downward curved pipe section 42B is set at the opening of the pressure relief device attachment section 56 provided in the second downward curved pipe section 42B, the fin 300B , protrudes inward of the second downwardly curved pipe portion 42B from the virtual line FL.
Note that in this embodiment, the fins 300B are made to protrude inward from the second downwardly curved pipe portion 42B rather than the virtual line FL, but the fins 300B may be made to protrude as necessary, and may not be made to protrude. good.

Normally, a slit S is provided as a gap between the opening 302 and the fin 300B, and the fin 300B is spaced apart from the opening 302 during normal times. Therefore, in the normal flow regulating member 300, air can be passed in the vertical direction via the cylindrical portion 300A.

The fins 300B are inclined with respect to the vertical direction so as to guide the direction of drainage flowing from the upstream kitchen sink 16 toward the reduced diameter pipe portion 44 side. In other words, the fins 300B serve to direct the direction of the flow of the waste water diagonally downward on the downstream side in the drainage direction so that the waste water flowing from the upstream side becomes difficult to flow into the pressure relief device 66 side. Note that the fins 300B are curved similarly to the second downwardly curved pipe section 42B, and the drainage water flows along the curved fins 300B, so that the normal flow of drainage water is not obstructed.

By the way, if a large amount of waste water is temporarily discharged from the kitchen sink 16 to the fin 300B protruding into the inside of the second downward curved pipe portion 42B (for example, if a large amount of water accumulated in the kitchen sink 16 is discharged at once) In the case of flushing (so-called sinking), the fins 300B are pushed by a large amount of drainage water and swing in the direction of arrow A, thereby closing the opening 302. Thereby, the waste water discharged from the kitchen sink 16 can be efficiently flowed to the downstream side while preventing it from flowing back to the pressure relief device 66 side.

When the fin 300B is pushed by a large amount of drainage and swings in the direction of arrow A, and contacts the opening 302 and closes the opening 302, in other words, when the opening 302 is closed, the two points in FIG. As shown by the chain line, the fins 300B are arranged so that the fins 300B do not enter the inside of the cylindrical part 300A through the opening 302, but protrude to the outside of the opening 302 (to the inside of the second downwardly curved pipe part 42B). The size (for example, the length in the major axis direction of the elliptical shape) is set larger than the opening 302.

If the size of the fin 300B is smaller than the opening 302 and the fin 300B pushed by the drainage enters the inside of the cylindrical part 300A through the opening 302, the fin 300B will be caught on the inner surface of the cylindrical part 300A, There is a concern that the fins 300B may not return to their original positions when the drainage water stops flowing.

In this embodiment, when the opening 302 is closed with the fin 300B, a part of the fin 300B protrudes to the outside of the opening 302, but when the fin 300B is pushed by drainage water, If the fins 300B do not enter inside the cylindrical portion 300A and the drainage water stops flowing, the fins 300B may return to their original positions.

For example, when the fins 300B are pushed by drainage and close the opening 302, the surface of the fins 300B may match the imaginary line FL that connects to the inner peripheral surface of the second downwardly curved pipe section 42B. .

When a large amount of wastewater flows and blocks the opening 302, if the surface of the fin 300B matches the imaginary line FL connected to the inner peripheral surface of the second downward curved pipe section 42B, the second downward curved pipe section 42B is closed. There is no step inside the portion 42B that would create resistance to the flow of waste water, allowing a large amount of waste water to flow more efficiently.

As shown in FIGS. 19 and 21, a plurality of ribs 306 are formed on the outer surface of the fin 300B, in other words, on the outer surface facing the inside of the second downwardly curved tube portion 42B. The rib 306 extends in the longitudinal direction of the second downwardly curved pipe portion 42B, in other words, along the flow of drainage.

If the outer surface of the fin 300B is a flat surface, garbage in the drainage water (for example, thin and sticky garbage such as onion skin) tends to stick to the outer surface of the fin 300B. When the ribs 306 are formed, the contact area between the fins 300B and dirt is reduced, so the dirt only touches the ribs 306, and the dirt is prevented from sticking to the fins 300B, in other words, from coming into close contact with the fins 300B. Ru. It should be noted that, as long as it is possible to suppress the sticking of garbage during drainage, instead of the ribs 306, protrusions having other shapes such as hemispherical shapes may be provided on the outer surface of the fins 300B.

(Second modification of pressure relief device)
Next, a pressure relief device 400 according to a second modification will be described with reference to FIGS. 22 to 29.
As shown in FIGS. 22 to 24, the pressure relief device 400 according to the second modification includes a thin elastic expansion/contraction body 468 made of an elastic material such as rubber, and a lower part that supports the lower end side of the elastic expansion/contraction body 468. It includes a side support member 470, an upper support member 472 that supports the upper end side of the elastic expansion/contraction body 468, a cover 474, and the like.

As shown in FIGS. 25 and 26, the elastic expansion/contraction body 468 is a cylindrical body having an outlet and an inlet. The elastic expansion/contraction body 468 includes a cross-shaped cylindrical expansion/contraction section 468A including four expansion/contraction pieces 488 extending radially (radially outward) from the axis when viewed from the axial direction. Therefore, a space S having a cross-shaped cross section and extending in the axial direction is provided inside the expansion/contraction section 468A.

A base portion 468B having a circular outer shape is integrally formed at both axial ends of the expansion/contraction portion 468A. An annular attachment portion 468C for attaching the elastic expansion/contraction body 468 to the lower support member 470 and the upper support member 472 is integrally formed on the outer peripheral portion of the base portion 468B. Further, a thick rib 468D is formed at the end of the attachment portion 468C.

As shown in FIG. 26(B), the expansion/contraction piece 488 includes a pair of wall portions 488A that are parallel to each other and spaced apart, and the pair of wall portions 488A are arranged at the radially outer end of each of the wall portions 488A. They are connected to each other via a connecting wall 488B.
In addition, one expansion/contraction piece 488 and the other expansion/contraction piece 488 that are adjacent to each other have mutually adjacent wall surfaces 488A connected to each other via an arcuate wall portion 488C having an arcuate cross section.

Here, as shown in FIG. 26(B), a pair of wall portions 488A of the expansion/contraction piece 488 are seen from the axial direction by cutting the axially intermediate portion of the elastic expansion/contraction body 468 in a direction crossing the axis. When the interval is A and the diameter of a virtual inscribed circle FC inscribed in the four arcuate walls 488C at the center of the elastic expansion/contraction body 468 is B, the interval A<diameter B.

As shown in FIG. 25, a corner portion 490 formed by a wall portion 488A of one expansion/contraction piece 488, a wall portion 488A of the other expansion/contraction piece 488, and a base portion 468B has a wall portion extending from the base portion 468B. A rising portion 492 is formed which has an arcuate cross-sectional shape (or may be an inclined surface inclined with respect to the base portion 468B) that rises smoothly toward the base portion 488A. As shown in FIG. 26(A), the rising portion 492 has a substantially triangular shape when viewed from the axial direction.

In the portion where this rising portion 492 is formed, the diameter B (see FIG. 26(B)) of the virtual inscribed circle FC described above gradually increases toward the outside in the axial direction.

When the pressure in the internal space S becomes higher than the external pressure (atmospheric pressure), the expanding/contracting portion 468A is configured such that when the pressure in the internal space S becomes higher than the external pressure (atmospheric pressure), the portion that is concave inward in the radial direction retracts outward in the radial direction (for example, in the direction of the arrow shown in FIG. 26(B)). ).

If the expanding/contracting part 468A has a cylindrical shape, in order to expand the expanding/contracting part 468A radially outward, the elastic member constituting the expanding/contracting part 468A must itself expand. In other words, when inflating the expanding/contracting part 468A, the internal pressure of the expanding/contracting part 468A must be considerably large.

On the other hand, as shown in FIG. 26(B), the expanding/contracting portion 468A of this embodiment has a cross-shaped cross section, so during the expansion process, the portion concave inward in the radial direction becomes radially inward due to internal pressure. Although the shape of the expanding/contracting portion 468A is deformed by being pushed outward in the direction, only a small amount of tension is applied to the elastic body itself, in contrast to when the expanding/contracting portion 468A is cylindrical.

Therefore, the expandable/contractable part 468A can easily expand its volume when air flows in, and can further suppress an increase in internal pressure compared to the case where the expandable/contractable part 468A has a cylindrical shape.

In addition, if the raised part 492 is formed in the corner part 490 of the elastic expansion/contraction body 468 as in this embodiment, if the raised part 492 is not formed in the corner part 490, in other words, one side of the corner part 490 Compared to the case where the wall portion 488A, the other wall portion 488A, and the base portion 468B are connected at right angles to each other, the expanding/contracting portion 468A is more likely to expand outward, making it easier to suppress an increase in internal pressure.

On the other hand, when the downstream side of the pipe trap 24 in the drainage direction becomes negative pressure and the pressure in the space S inside the expansion/contraction part 468A becomes lower than the external pressure (atmospheric pressure), the expansion/contraction piece One wall portion 488A and the other wall portion 488A of the 488 that face each other may come into close contact with each other. However, in the axial center portion of the expansion/contraction part 468A, there is a through space S1 (a part of the space S) surrounded by four arcuate walls 488C and passing through the outlet and inlet of the elastic expansion/contraction body 468 in a straight line. The shape, size (radius of curvature), etc. of the arcuate wall portion 488C are set so that a gap serving as an air passage remains.

That is, when the internal space S becomes negative pressure, the expansion/contraction portion 468A has its inner circumferential surfaces in close contact with each other, and the space S is prevented from completely disappearing. Therefore, in the elastic expansion/contraction body 468 of this embodiment, even if the internal space S becomes negative pressure, the through space S1 through which it is inserted in the axial direction is secured, so that ventilation in the axial direction is possible.

As shown in FIGS. 23, 24, and 27, a lower support member 470 is inserted into the lower attachment portion 468C of the elastic expansion/contraction body 468, and the attachment portion 468C includes the lower support member 470, It is fixed to the lower support member 470 by being sandwiched between a mounting ring 496 disposed on the outside of the mounting portion 468C. Note that the rib 468D of the attachment portion 468C is inserted into an annular groove 478 formed on the outer periphery of the lower support member 470 and is compressed.

Further, an upper support member 472 is inserted into the upper attachment portion 468C of the elastic expansion/contraction body 468, and the attachment portion 468C is between the upper support member 472 and the attachment ring 496 disposed on the outside of the attachment portion 468C. The upper support member 472 is fixed to the upper support member 472 by being held between the two. Note that the rib 468D of the attachment portion 468C is inserted into an annular groove 478 formed on the outer periphery of the upper support member 472 and is compressed.

As shown in FIGS. 22 and 28, the cylindrical cover 474 is composed of a first half member 474A on one side with the axis in between, and a second half member 474B on the other side. . The cover 474 of this embodiment is a synthetic resin molded product (for example, an injection molded product).

The first half-split member 474A includes an arcuate wall portion 474Aa formed by halving a cylinder, an arcuate flange 474Ab is formed at the upper end, and an arcuate flange 474Ac is formed at the lower end.
The second half-split member 474B includes an arc wall portion 474Ba that is a half of a cylinder, an arc-shaped flange 474Bb is formed at the upper end, and an arc-shaped flange 474Bc (see FIG. 23) is formed at the lower end.

The arc wall portion 474Ba of the second half member 474B protrudes toward the inner surface of the arc wall portion 474Ba of the second half member 474B at the inner end of the arc wall portion 474Aa of the first half member 474A. A plurality of claw members 474Ae are formed to be hooked into the engagement holes 474Bd formed in the .

Further, an end portion on the inner surface side of the arc wall portion 474Ba of the second half member 474B protrudes toward the inner surface side of the arc wall portion 474Aa of the first half member 474A. A plurality of claw members 474Be are formed to be hooked into engagement holes 474Ad formed in the portion 474Aa.

By facing the first half member 474A and the second half member 474B and hooking the claw member 474Be into the engagement hole 474Ad and hooking the claw member 474Ae into the engagement hole 474Bd, the first half member 474A and The second half member 474B is fixed to each other to form a cylindrical cover 474.

As shown in FIG. 28, grooves 474Af are formed adjacent to the flanges on both axial sides of the inner circumference of the first half member 474A, and grooves 474Af are formed on both axial sides of the inner circumference of the second half member 474B. A groove 474Bf is formed adjacent to the flange. As shown in FIG. 23, a mounting ring 496 to which the elastic expansion/contraction body 468 is fixed is inserted into the groove 474Af of the first half member 474A and the groove 474Bf of the second half member 474B.

As a result, the upper mounting ring 496 to which the elastic expansion/contraction body 468 is fixed is attached to the stepped portion formed at the widthwise end of the upper groove 474Af of the cover 474 and the stepped portion formed at the widthwise end of the groove 474Bf. A lower mounting ring 496 that is hooked on and fixes the elastic expansion/contraction body 468 is formed at a step formed at the widthwise end of the groove 474Af on the lower side of the cover 474 and at a widthwise end of the groove 474Bf. It gets caught on the step. As a result, the elastic expansion/contraction body 468 to which the lower support member 470 and the upper support member 472 are attached is fixed inside the cover 474.

Since the upper support member 472 and the lower support member 470 to which the elastic expandable body 468 is fixed in this way are fixed inside the cover 474, even if the elastic expandable body 468 is deformed due to a change in internal pressure, Movement of the elastic expandable body 468 in the axial direction is suppressed.

The elastic expansion/contraction body 468 supports the lower support member 470 and the upper support member 472 from the expansion/contraction direction of the elastic expansion/contraction body 468 (the direction that intersects with the axial direction of the elastic expansion/contraction body 468) and the axial direction that intersects with the expansion/contraction direction. It is covered with a cover 474 and is protected from contacting any member other than the cover 474.

Note that when the elastic expansion/contraction body 468 expands/contracts inside the cover 474 , a second hole is provided so that air can go back and forth between the space S2 between the cover 474 and the elastic expansion/contraction body 468 and the outside air outside the cover 474 . A slit 474g is formed on the lower side in the axial direction in the first half member 474A and the second half member 474B. Thereby, the elastic expandable/contractable body 468 can be easily expanded/contracted.

A tapered through hole 480 is formed in the center of the lower support member 470, and an insertion tube portion 482 communicating with the through hole 480 projects downward at the center of the lower surface. This insertion tube portion 482 is inserted into the pressure relief device attachment portion 56 of the tube trap 24, and the pressure relief device 400 is attached to the tube trap 24.

As shown in FIGS. 23 and 27, a cylindrical check valve mounting portion 486 projects upward from the center of the upper support member 472. A male screw 486A is formed on the outer periphery of the check valve attachment portion 486, and the vent valve 110 is attached to the check valve attachment portion 486 by this male screw 486A.

As shown in FIG. 27, a plurality of ribs 502 are formed on the inner circumferential surface of the check valve mounting portion 486, protruding inward in the radial direction and extending in the axial direction. As a result, as shown in FIG. 29(A), a gap S3 through which air flows in the axial direction is formed between the valve body 412, which will be described later, and the inner peripheral surface of the check valve mounting portion 86. There is.

As shown in FIGS. 27 and 29, a valve body support portion 504 is formed at the lower end of the check valve mounting portion 86 to prevent a valve body 412 (described later) from falling into a pressure relief device 466 below. Note that the valve body support portion 504 is formed with a plurality of holes 506 through which air passes.

As shown in FIGS. 23 and 29(A), the valve body 412 is disposed on the valve body support portion 504 inside the check valve mounting portion 486. The specific gravity of the valve body 412 is set so that it floats on the drainage water.

The valve body 412 is generally formed into a substantially truncated conical shape. The valve body 412 has an annular recess 412A having an arcuate cross section formed in its upper radially outer portion.

An annular valve seat 508 made of an elastic material such as rubber is attached to the upper part of the check valve attachment part 486.
As shown in FIG. 29(A), normally, the valve body 412 placed on the valve body support portion 504 is spaced apart from the valve seat 508, and there is a gap between the valve body 412 and the valve seat 508. Air flows vertically through S4.

On the other hand, when the drainage water flowing backward and rising from the pressure relief device 466 below reaches the valve body 412, the valve seat 412 floats on the drainage water (not shown) and touches the valve seat 508, as shown in FIG. 29(B). This contacts and closes the valve hole 508A formed in the center of the valve seat 508.
Therefore, even if drainage water intrudes into the inside of the pressure relief device 466, the drainage water that flows backward and rises from the pressure relief device 466 is prevented from flowing into the vent valve 110 disposed above.

As shown in FIG. 27, a plurality of protrusions 472A (only one is shown in FIG. 27) that protrude radially outward are formed on the outer circumference of the upper support member 472. This protrusion 472A is inserted into a fitting hole 510 formed in the first half member 474A and the second half member 474B. Thereby, the upper support member 472 and the cover 474 are made relatively unrotatable.

Note that since such a projection 472A is not formed on the outer circumference of the lower support member 474, the attachment ring 496 is inserted into the groove 474Af and the groove 474Bf of the cover 474 and the lower support member 474 is attached to the shaft. It is possible to rotate relative to the cover 474 while being prevented from moving in that direction.

(Assembling procedure of pressure relief device 400)
As an example, the pressure relief device 400 is assembled as follows.

(1) The upper support member 472 is attached to one side of the elastic expansion/contraction body 468 in the axial direction using the attachment ring 496, and the lower support member 474 is attached to the other side of the elastic expansion/contraction body 468 in the axial direction using the attachment ring 496.

(2) Arranging the above-mentioned elastic expansion/contraction body 468 to which the upper support member 472 and the lower support member 474 are attached between the first half member 474A and the second half member 474B facing each other, The first half member 474A and the second half member 474B are combined so that the projection 472A of the upper support member 472 is inserted into the fitting hole 510.

(3) Insert the valve body 412 into the check valve mounting part 486 and attach the valve seat 508 to the upper part of the check valve mounting part 486.

(4) Finally, the vent valve 110 is screwed into the check valve mounting portion 486 of the upper support member 472, and the vent valve 110 is fixed to the check valve mounting portion 486. At this time, the cover 474 of the pressure relief device 400 can be grasped and fixed with one hand, the vent valve 110 can be grasped with the other hand, and the vent valve 110 can be screwed into the check valve mounting portion 486. The upper support member 472 and the cover 474 are attached so that they cannot rotate relative to each other, so as long as the cover 474 is held and fixed by hand, it is easy to screw the vent valve 110 into the check valve mounting part 486. Upper support member 472 does not rotate.

(5) Insert the insertion tube portion 482 of the pressure relief device 466 to which the vent valve 110 is attached into the pressure relief device attachment portion 56 of the tube trap 24, and attach the pressure relief device 400 to the tube trap 24.

In addition, in the pressure relief device 400 of this embodiment, the lower support member 474 can rotate relative to the cover 474. However, if a protrusion 472A similar to that of the upper support member 472 is formed on the outer periphery of the lower support member 474, and the protrusion 472A is inserted into the fitting hole 510 of the cover 474, the lower support member 474 and the cover 474 are connected. If the pressure relief device 400 is made relatively unrotatable, care must be taken when assembling the pressure relief device 400 as described below.

Since the first half member 474A and the second half member 474B are molded products, the positions of the upper fitting hole 510 and the lower fitting hole 510 are fixed. That is, the positional relationship between the upper fitting hole 510 and the lower fitting hole 510 in the circumferential direction is determined.

Therefore, when attaching the lower support member 470 and the upper support member 472 to the elastic expandable body 468, the circumferential positional relationship between the protrusion 472A of the lower support member 470 and the protrusion 472A of the upper support member 472 ( circumferential direction angle) needs to be determined according to the positional relationship of the two fitting holes 510 formed in the first half member 474A and the second half member 474B.

Here, with respect to the circumferential positional relationship between the upper fitting hole 510 and the lower fitting hole 510 formed in the first half member 474A and the second half member 474B, If the circumferential positional relationship between the protrusion 472A of the lower support member 470 and the protrusion 472A of the upper support member 472 attached to the Each protrusion 472A must be inserted into each fitting hole 510 after twisting and adjusting the positional relationship.

By doing this, it is possible to attach the cover 474, but if the elastic expandable body 468 is fixed inside the cover 474 in a twisted state, unnecessary deformation (distortion) will occur in the elastic expandable body 468. This may cause problems such as the elastic expansion/contraction body 468 becoming difficult to expand/contract.

On the other hand, in the pressure relief device 400 of this embodiment, since the lower support member 474 does not have the protrusion 472A that is inserted into the fitting hole 510, the protrusion 472A of the upper support member 472 is connected to the first half member 474A, By simply combining the first half member 474A and the second half member 474B in accordance with the upper fitting hole 510 formed in the second half member 474B, the elastic expandable member 468 can be covered without twisting. 474. Thereby, the cover 474 can be easily attached, and the expansion/contraction performance of the elastic expansion/contraction body 468 can be ensured.

[Other embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it is of course possible to implement various modifications other than the above without departing from the spirit thereof. It is.

In the above embodiment, the kitchen sink 16 corresponds to the first plumbing device of the present invention, and the dishwasher 18 corresponds to the second plumbing device of the present invention, but the first plumbing device, The second plumbing device may be any device that drains water, and the type thereof is not particularly limited. Examples of the plumbing equipment include a sink, a washing machine, a bathtub, and a washing area, but other equipment may be used.

In the drain pipe structure 10 of the above embodiment, the kitchen sink 16 is provided with the disposer 20, but the disposer 20 may not be provided.

In the above embodiment, the vent valve 110 is used as an example of the vent part, but the present invention is not limited to this, and when the inside of the pipe on the downstream side of the pipe trap 24 becomes negative pressure, outside air can be introduced. Any other structure may be used instead of the vent valve as long as it can suppress the negative pressure. For example, instead of the vent valve 110, one end of the piping may be connected to the pressure relief device 66, and the other end of the piping may be connected to the drainage stack 34 or the like. In this case, the air inside the drain pipe 34 can be introduced into the pipe on the downstream side of the pipe trap 24 to suppress the negative pressure in the pipe.

The pressure relief device 66 and the vent valve 110 may be provided as necessary, and may not be provided if seal breakage can be suppressed.

Although the temporary storage portion 204 is formed in a cylindrical shape with the vertical direction as the axial direction, the shape is not limited to this, and may be any shape such as a rectangular parallelepiped. Further, although the axis X1 of the inlet 204A is eccentric with respect to the axis Z of the temporary storage section 204, it may be configured not to be eccentric. Although the axis X2 of the outlet 204B is not eccentric with respect to the axis Z of the temporary storage section 204, it may be eccentric.

Although the rising portion 208 is provided between the temporary storage portion 204 and the siphon drain pipe 30 in the second drainage system 2, the structure may be such that the rising portion 208 is not provided. Further, although the pressure reduction pipe 206 is provided between the temporary storage section 204 and the rising section 208 in the second drainage system 2, a configuration in which the pressure reduction pipe 206 is not provided may also be used. good.

1... First drainage system, 2... Second drainage system, 10... Drain pipe structure, 16... Kitchen sink (first plumbing equipment), 18... Dishwasher (second plumbing equipment), 24 ... Pipe trap (first drain trap), 30... Siphon drain pipe, 36... Inflow side pipe connection part (inflow part), 36CL... Axis of inflow part, 38A... First downward curved pipe part, 38B... First upstream Curved pipe section, 42A... Second upward curved pipe section, 42B... Second downward curved pipe section, 66... Pressure buffer device, 110... Ventilation valve (ventilation section), 202... Primary drainage trap (second drainage trap), 203...Secondary drain trap (third drain trap), 204...Temporary storage section, 204A...Inlet, 204B...Outlet, 206...Pressure reduction piping, 206C...Outlet, 208...Rising portion, 222...Inlet, 224...Outlet , 232... Inlet, 234... Outlet, 236... Branch pipe, 238... Inlet, 240... Outlet, 242... Drainage, L1... Tangent line, La... Horizontal distance, Lb... Horizontal distance, R1... Curvature radius, R2... Curvature radius

Claims (6)

a first drainage system for discharging wastewater from the first water equipment;
a second drainage system for discharging wastewater from the second plumbing equipment;
a siphon drainage pipe in which the first drainage system is connected to the upstream side and the second drainage system is connected to the downstream side of the first drainage system;
a pressure reduction pipe that is provided in the second drainage system and reduces drainage pressure in the second drainage system;
has
A cylinder provided in the second drainage system, with an inlet located at a higher position than the outlet, a volume per unit length of the second drainage system being partially expanded, and with the vertical direction as the axial direction. It has a temporary storage part formed in the shape of
The inlet is formed in a cylindrical shape with the axial direction in the horizontal direction,
The axial center of the inlet is eccentric with respect to the axial center of the temporary storage part,
The outlet is formed in a cylindrical shape with the axial direction in the horizontal direction,
A drainage pipe structure in which the axial center of the outlet is not eccentric with respect to the axial center of the temporary storage section . a first drainage system for discharging wastewater from the first water equipment;
a second drainage system for discharging wastewater from the second plumbing equipment;
a siphon drainage pipe in which the first drainage system is connected to the upstream side and the second drainage system is connected to the downstream side of the first drainage system;
a pressure reduction pipe that is provided in the second drainage system and reduces drainage pressure in the second drainage system;
has
A drainage pipe structure in which a rising part is provided between the pressure reduction pipe and the siphon drainage pipe in the second drainage system, and the pipe goes down once and then goes up. a first drainage system for discharging wastewater from the first water equipment;
a second drainage system for discharging wastewater from the second plumbing equipment;
a siphon drainage pipe in which the first drainage system is connected to the upstream side and the second drainage system is connected to the downstream side of the first drainage system;
a pressure reduction pipe that is provided in the second drainage system and reduces drainage pressure in the second drainage system;
has
a first drainage trap is provided in the first drainage system;
The first drainage trap is
an inflow section that directs the inflowing wastewater downward;
a first downwardly curved pipe section provided below the inflow section and curved downward from the upper side in the vertical direction toward the horizontal direction;
a first upward curved pipe section that is provided on the drainage downstream side of the first downward curved pipe section and curves upward from the horizontal direction to the upper side in the vertical direction;
a second up-curving pipe section provided on the downstream side of the first up-curving pipe section in the drainage direction and curving upward from the vertically lower side toward the horizontal direction;
a second downwardly curved pipe section that is provided downstream of the second upwardly curved pipe section in the drainage direction and curves downward from the horizontal direction toward the bottom in the vertical direction;
a pressure buffer device that is disposed above the second downwardly curved pipe section, communicates with the second downwardly curved pipe section, and buffers pressure within the pipe;
has
A drain pipe structure in which a ventilation section capable of taking in air from the outside is provided on the pressure buffer device on the downstream side of the water-sealed portion of the first drain trap. The drain pipe structure according to any one of claims 1 to 3, wherein the pressure reduction pipe has a bent pipe line. The drain pipe structure according to any one of claims 1 to 3, wherein the pressure reduction pipe has a pipe line whose inner diameter changes to a small diameter. The drain pipe structure according to any one of claims 1 to 3, wherein the pressure reduction pipe has a branch pipe branching from a pipe running from upstream to downstream and having a closed end.