JP2016102297A - Shock absorber, expansion body and drainage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock absorber for rapidly and stably easing pressure fluctuation in a drain pipe.SOLUTION: An shock absorber 100 includes an expansion body 120 capable of varying its capacity in accordance with increase and decrease of an internal pressure in a drain pipe. The expansion body 120 includes a hollow cylinder wall having one end opened and the other end closed, a plurality of outer grooves 124 cut along a circumferential direction of the cylinder wall from an outer surface, and a plurality of inner grooves 125 cut along the circumferential direction of the cylinder wall from an inner surface. The outer groove 124 and the inner groove 125 are alternately formed along an axial direction of the cylinder wall, and a groove width of the outer grooves 124 and a groove width of the inner grooves 125 are varied, and the expansion body expands or contracts in the axial direction.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a shock absorber, a telescopic body, and a drainage system that are attached to a drainage pipe and relieve fluctuations in the internal pressure of the drainage pipe.

  In a structure such as a building, when draining through a drain pipe, negative pressure and positive pressure are generated in the drain pipe as the drainage flows through the drain pipe. When negative pressure is generated in the drain pipe, abnormal noise may be generated in the drain pipe, or trap water containing a bad odor in the drain pipe may flow out and the sealed water may be broken. On the other hand, when an excessive positive pressure is generated in the drain pipe, trapped water or odor may spout out. Conventionally, various devices have been used to reduce such fluctuations in the internal pressure of the drain pipe.

  For example, Patent Literature 1 discloses a siphon drainage system that relieves positive pressure generated in a drain pipe when flowing down drainage and suppresses stagnation of drainage near a drain port of a watering device. The siphon drainage system (10) includes a drainage introduction pipe (18) that extends downward from the watering device (12) and allows the wastewater from the watering device (12) to flow downward, and the drainage introduction pipe (18). A lateral pulling pipe (24) that communicates and extends in the lateral direction and flows the drainage from the drainage introduction pipe (18) laterally, and communicates with the lateral pulling pipe (24) and extends downward, and the lateral pulling pipe The drainage pipe (26) that generates siphon force by flowing down the drainage from (24) and the drainage introduction pipe (18) communicated with the drainage introduction pipe (18) and pressed by the drainage from the watering device (12) ( 18) It is provided with a sealed air chamber (28) in which the air inside can be introduced and the interior of the chamber can be expanded and contracted. The air chamber (28) is defined by a bag member (34) or a bellows-like member (37) whose volume can be varied. The bellows-like member (37) has an upper end closed, the other end opened, and the open end communicated. The bellows-like member (37) has a bellows-like side wall (37A) that can be expanded and contracted, and when the side wall (37A) is extended, the air chamber (28) is expanded and the side wall (37A) is contracted. The air chamber (28) is reduced. In addition, the code | symbol of patent document 1 was shown in ().

JP 2011-12536 A

  In the siphon drainage system of Patent Document 1, the bag member expands like a balloon in order to relieve the positive pressure in the drainage pipe, and expands its internal space. Therefore, when the positive pressure of the drain pipe exceeds the allowable range of the bag member, there is a problem that the peripheral wall of the bag member becomes thin and easily bursts. On the other hand, the bellows-like member of the siphon drainage system of Patent Document 1 is advantageous in terms of operation stability and durability because there is no risk of bursting compared to the bag member because the expansion and contraction movement of the internal space is determined by the bellows structure. is there. A general bellows-like member such as Patent Document 1 is formed in an initial molded shape by injection molding or blow molding. That is, the bellows-like member elastically deforms and expands and contracts from the initial molded shape (original shape) where no pressure is applied according to the positive pressure or negative pressure in the drain pipe, and when the positive pressure or negative pressure in the drain pipe is eliminated, It operates to return to its original shape by elastic return force. However, in order to elastically deform the bellows-like member from its original shape, a momentary large force is required for the initial movement of the expansion and contraction. For this reason, the elastic deformation of the bellows-like member requires a correspondingly large pressure, and there has been a problem that the response to the pressure fluctuation in the drain pipe is delayed or it is difficult to operate at a weak pressure.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a shock absorber, a telescopic body, and a drainage system that can quickly and stably relieve pressure fluctuations in the drain pipe.

The shock absorber according to claim 1 is a shock absorber that is attached to a drain pipe and relieves fluctuations in the internal pressure of the drain pipe,
Equipped with a stretchable body whose volume can be changed according to the increase or decrease of the internal pressure of the drainage pipe,
The stretchable body has a hollow cylindrical wall portion that is open at one end and closed at the other end, a plurality of outer groove portions cut from the outer surface along the circumferential direction of the cylindrical wall portion, and the circumferential direction of the cylindrical wall portion A plurality of inner grooves cut from the inner surface along the outer wall, and the outer grooves and the inner grooves are alternately formed in the axial direction of the cylindrical wall portion, the groove width of each outer groove and the groove width of each inner groove. And the elastic body expands and contracts in the axial direction.

  The shock absorber according to claim 2 is the shock absorber according to claim 1, wherein the stretchable body is disposed inside the body of the shock absorber and / or inside the drain pipe, and the inside of the stretch body is inside the drain pipe. It is open to the external environment without communication, and the stretchable body contracts when the inside of the drain pipe becomes positive pressure.

  The shock absorber according to claim 3 is the shock absorber according to claim 1 or 2, wherein the stretchable body hangs down by its own weight so that the other end of the cylindrical wall portion is positioned vertically downward in a natural state, and the expansion allowance is increased. It is characterized in that it is extended by a predetermined length in the state that it is left.

  The shock absorber according to claim 4 is the shock absorber according to any one of claims 1 to 3, wherein the expansion and contraction body closes the other end of the cylindrical wall portion and receives an air flow from the drain pipe. A cup-shaped receiving part opened on the end side is provided.

  The shock absorber according to claim 5 is the shock absorber according to claim 1, wherein the stretchable body is disposed in an external environment of the drain pipe, and the inside of the stretch body communicates with the inside of the drain pipe. The stretchable body is extended when a positive pressure is reached.

The stretchable body according to claim 6 is a stretchable body attached to a drain pipe and capable of changing in volume according to fluctuations in the internal pressure of the drain pipe,
A hollow cylindrical wall having one end open and the other end closed;
A plurality of outer grooves cut from the outer surface along the circumferential direction of the cylindrical wall,
A plurality of inner grooves cut from the inner surface along the circumferential direction of the cylindrical wall, and
The outer groove portion and the inner groove portion are alternately formed in the longitudinal direction of the cylindrical wall portion, and the groove width of the outer groove portion and the groove width of the inner groove portion vary to expand and contract in the axial direction.

A drainage system according to claim 7, wherein a drainage main pipe for flowing wastewater, and a drainage pipe comprising a branch pipe connected to the drainage main pipe,
The shock absorber according to any one of claims 1 to 5 attached to the branch pipe.

  According to the shock absorber of the first aspect, the expansion and contraction body extends or contracts in the axial direction so that the groove widths of the outer groove portion and the inner groove portion fluctuate in order to alleviate the pressure fluctuation inside the drain pipe. In particular, the plurality of outer groove portions are cut from the outer surface along the circumferential direction of the cylindrical wall portion, and the plurality of inner groove portions are cut from the inner surface along the circumferential direction of the cylindrical wall portion. That is, since the groove portion is formed of a cut line, the form in which the cylindrical wall portion is completely contracted so that the groove width is substantially zero is maintained as the original shape. And the volume of the said expansion-contraction body increases because a cylinder wall part is expand | deployed to an expansion | extension direction from this contraction form. That is, since the expansion body of the shock absorber of the present invention expands and contracts when the cylindrical wall portion is expanded or folded in the axial direction via the groove portion, compared to a conventional elastically deformable bellows molded product, It can be easily deformed with weaker force. Therefore, the shock absorber of the present invention can alleviate pressure fluctuation in the drain pipe quickly and stably.

  According to the shock absorber of claim 2, in addition to the effect of the invention of claim 1, the telescopic body is the main body of the shock absorber so that the inside of the telescopic body is opened to the external environment without communicating with the inside of the drain pipe. It is arranged inside and / or inside the drain pipe. That is, when the inside of the drain pipe becomes a positive pressure, the air inside the expansion / contraction body is discharged to the external environment, and at the same time, the groove width is narrowed and the expansion / contraction body contracts. On the other hand, when the inside of the drain pipe becomes a negative pressure, outside air is introduced into the expansion / contraction body, and at the same time, the groove width widens, and the expansion / contraction body expands. As described above, since the stretchable body is disposed so as not to be exposed to the external environment, the stretchable body can be protected from the external environment, and the outer shape or appearance of the shock absorber can be kept compact regardless of the expansion / contraction of the stretchable body.

  According to the shock absorber of claim 3, in addition to the effect of the invention of claim 1 or 2, in a natural state where the drain pipe interior is not positive pressure or negative pressure, the stretchable body hangs down by its own weight, and is given a predetermined amount by gravity. Elongates and deforms to the groove width. In this natural state, the stretchable body is in a state of being balanced by gravity, so that it can be stretched and deformed quickly in response to fluctuations in the internal pressure of the drain pipe.

  According to the shock absorber of claim 4, in addition to the effect of the invention of any one of claims 1 to 3, the receiving portion opens in the same direction as the expansion / contraction direction of the expansion / contraction body. Effectively receives the airflow accompanying the pressure fluctuation at the receiving part, and assists the expansion and contraction movement.

  According to the shock absorber described in claim 5, in addition to the effect of the invention of claim 1, the stretchable body is disposed in the external environment of the drainage pipe so that the inside of the stretchable body communicates with the inside of the drainage pipe. That is, the negative pressure inside the drain pipe causes the air inside the expansion body to be discharged into the drain pipe, and at the same time, the groove width is narrowed and the expansion body contracts. On the other hand, when the inside of the drain pipe becomes positive pressure, the air is introduced into the stretchable body, and at the same time, the groove width is widened, and the stretchable body is extended.

  According to the stretchable body of the sixth aspect, the stretchable body expands or contracts in the axial direction so that the groove widths of the outer groove portion and the inner groove portion vary. In particular, the plurality of outer groove portions are cut from the outer surface along the circumferential direction of the cylindrical wall portion, and the plurality of inner groove portions are cut from the inner surface along the circumferential direction of the cylindrical wall portion. That is, since the groove portion is formed of a cut line, the form in which the cylindrical wall portion is completely contracted so that the groove width is substantially zero is maintained as the original shape. And the volume of the said expansion-contraction body increases because a cylinder wall part is expand | deployed to an expansion | extension direction from this contraction form. That is, the stretchable body of the present invention expands and contracts when the cylindrical wall portion is expanded or folded in the axial direction via the groove portion, and therefore has a weaker force than a conventional elastically deformable bellows molded product. It can be easily deformed. Therefore, the stretchable body of the present invention can operate in response to pressure fluctuation in the drain pipe quickly and stably.

  According to the drainage system of the seventh aspect, the effect of the shock absorber according to any one of the first to fifth aspects can be exhibited as the entire drainage system. Therefore, the drainage system of the present invention can quickly and stably relieve pressure fluctuations in the drainage pipe by the shock absorber.

1 is a schematic perspective view of a shock absorber according to an embodiment (Embodiment 1) according to the present invention. The (a) top view and (b) side view of the buffering device of FIG. The AA longitudinal cross-sectional view of the buffering device of FIG.2 (b). BB sectional drawing of the shock absorber of FIG. 1 shows a stretchable body of the shock absorber of FIG. 1, (a) is a longitudinal sectional view of the contracted form of the stretched body, (b) is a CC sectional view thereof, and (c) is an expanded form of the stretched body. It is a longitudinal cross-sectional view, (d) is the DD cross-sectional view. The disassembled perspective view of the shock absorber of FIG. The exploded perspective view of the drainage system of one embodiment. . It is a fragmentary sectional view of the drainage system of Drawing 7, (a) shows the natural state of a drain pipe, (b) shows the positive pressure state of a drain pipe, and (c) shows the negative pressure state of a drain pipe. In the drainage system of one embodiment of the present invention, the pressure fluctuation buffer structure which added the additional buffer device to the buffer device. Sectional drawing of the pressure fluctuation | variation buffer structure of FIG. Sectional drawing of the shock absorber of another embodiment (Embodiment 2) which concerns on this invention. Sectional drawing of the shock absorber of another embodiment (Embodiment 3) which concerns on this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the shape of each figure referred in the following description is a conceptual diagram or a schematic diagram for explaining a suitable shape dimension, and a dimension ratio etc. do not necessarily correspond with an actual dimension ratio. That is, the present invention is not limited to the dimensional ratio in the drawings.

[Embodiment 1]
In general, the drain pipe P includes a main pipe P1 through which drainage flows and a branch pipe P2 that branches from the main pipe P1 and opens upward. And when drainage flows into the main pipe P1 of the drain pipe P, the internal pressure of the drain pipe P fluctuates to a positive pressure or a negative pressure compared to the external pressure. In order to cope with such pressure fluctuations, pressure fluctuation mitigation measures are taken on the branch pipe P2 of the drain pipe P. That is, the shock absorber 100 according to the embodiment of the present invention is attached to the drain pipe P including the main pipe P1 and the branch pipe P1, and is configured to reduce fluctuations in the internal pressure of the drain pipe P. And the drainage system 10 of this embodiment is provided with the drainage pipe P and the buffering device 100 with which this drainage pipe P was mounted | worn. Hereinafter, with reference to FIG. 1 thru | or FIG. 6, the structure of the buffer device 100 of this embodiment is demonstrated in detail.

  FIG. 1 is a perspective view of a shock absorber 100 according to an embodiment of the present invention. 2A and 2B are a plan view and a front view of the shock absorber 100 (a shielding part is omitted for convenience of explanation). 3 and 4 are a longitudinal sectional view and a transverse sectional view of the shock absorber 100, respectively. FIG. 5 is a cross-sectional view of the stretchable body 120 constituting the shock absorber 100. FIG. 6 is an exploded perspective view of the shock absorber 100.

  As shown in FIGS. 1 to 4, the shock absorber 100 of the present embodiment has a connection portion 113 connected to the drain pipe P, and defines an internal space 118 that communicates with the inside of the drain pipe P and is isolated from the external environment. A hollow main body 110 and a hollow elastic body (volume varying body) 120 that is held by the main body 110 and whose volume varies according to the variation of the internal pressure of the drainage pipe P are provided. The internal space 118 is a pressure fluctuation space in which the pressure fluctuates with the inside of the drain pipe P. The volume of the internal space 118 is determined as the total volume inside the main body 111 minus the volume of the outer shape of the telescopic body 120. And the volume of the expansion-contraction body 120 increases / decreases according to the fluctuation | variation of the internal pressure of the drain pipe P, The sum total of the volume inside the interior space 118 and the drain pipe P fluctuates, and the pressure fluctuation inside the drain pipe P is relieved. The

  The main body 110 includes a peripheral wall 111 that is an exterior portion of the shock absorber 110, an upper wall 112 that partially closes the upper side of the peripheral wall 111, and a connection portion 113 that opens at the lower end of the peripheral wall 111. The peripheral wall 111 has a hollow cylindrical shape, and the lower portion has a reduced diameter compared to the upper portion. The upper wall 112 has a disk shape in plan view. A connecting portion 113 connected to the branch pipe P <b> 2 of the drain pipe P is provided at the lower end of the peripheral wall 111. The connecting portion 113 optionally includes a joint portion 113a that can be adapted to the diameter of the branch pipe P2. The peripheral wall 111, the upper wall 112, and the outer surface of the telescopic body 120 define an internal space 118 that communicates with the inside of the drain pipe P without communicating with the external environment (with the main body 110 connected to the branch pipe P2).

  Further, the main body 110 is provided with a support portion 114 for suspending the stretchable body 120 from the upper wall 112. The support portion 114 protrudes from the inner periphery of the peripheral wall 111, and defines a circular opening at the inner periphery. The diameter of the opening corresponds to the diameter of the opening end 122 at the upper end of the stretchable body 120. The support 114 and the upper wall 112 hold the open end 122 of the stretchable body 120 in a sealed state, thereby holding the stretchable body 120 at substantially the center in the radial direction of the peripheral wall 111.

  Further, a ventilation portion 115 is provided on the upper wall 112 of the main body 110 (the lower portion of FIG. 2A). The ventilation portion 115 functions to ventilate the supporting elastic body 120 and the external environment. As shown in FIG. 4, the ventilation portion 115 has a through-hole 115 a having a substantially arc shape in a plan view that is formed in the approximate center of the upper wall 112. The through hole 115 a is located inside the inner peripheral edge of the support portion 114. That is, the through hole 115a of the ventilation portion 115 allows the inside of the expansion / contraction body 120 to communicate with the external environment. And the fence-like part 115b is formed in the upper end of the surrounding wall 111 so that the upper direction of this through-hole 115a may be covered. The fence-like portion 115b prevents insects, dust, and the like from entering the inside of the expansion / contraction body 120 through the through hole 115a without hindering the ventilation into the expansion / contraction body 120. In the present shock absorber 100, the ventilation portion 115 communicates with the inside of the elastic body 120, but is isolated from the inside of the drain pipe P.

  An extension 116 is provided on the upper wall 112 of the main body 110 (upper portion in FIG. 2A) adjacent to the ventilation portion 115. The expansion unit 116 is closed by a lid-shaped blocking unit 117 when not in use, but an additional buffer (with the same configuration as the buffer device 100) is used to expand the pressure fluctuation buffering performance of the buffer device 100 as necessary. It functions to connect the device 100 ′ (see FIG. 9). In addition, although the interruption | blocking part 117 of this embodiment is a lid | cover material for obstruction | occlusion, a ventilation valve may be sufficient. The vent valve closes the expansion part 116 when the drain pipe P is in a natural state and at a positive pressure to prevent leakage of odors, etc., and sucks outside air when the drain pipe P is at a negative pressure to effectively eliminate the negative pressure. To work.

  As shown in FIG. 4, the extended portion 116 includes a crescent-shaped through hole 116 a formed in the vicinity of the outer peripheral edge of the upper wall 112, a fence-like portion 116 b provided at the inner edge of the through hole 116 a, And a cylindrical portion 116c erected substantially vertically from the upper wall 112 so as to communicate with the through hole 116a. The extended portion 116 (center of the cylindrical portion 116c) is eccentric from the center of the peripheral wall 111 in plan view. The through-hole 116 a is formed outside the inner peripheral edge of the support portion 114, and is positioned on the radially outer side of the opening end 122 of the stretchable body 120. Further, the ventilation portion 115 and the expansion portion 116 are isolated from each other by a partition wall portion 112 a erected from the upper wall 112. More specifically, the partition wall 112a is integrally formed on the inner wall of the cylindrical portion 116c, and the through hole 115a and the through hole 116a (inside the cylindrical portion 116c) are formed by bordering the periphery of the through hole 115a and covering the upper surface of the through hole 115a. It is isolated. That is, the through-hole 116a is arranged so as not to communicate with the inside of the expansion / contraction body 120 but communicate with the inside of the drain pipe P. As will be described later, when the additional shock absorber 100 ′ is added to the shock absorber 100, the air flow from the drain pipe P passes through the gas flow path 119 defined between the inner wall of the main body 110 and the expansion and contraction body 120, and extends the expansion portion 116. pass.

  In addition, although the main body 110 of the shock absorber 100 of the present embodiment is formed of a synthetic resin, the present invention is not limited to this, and various materials can be selected.

  Next, with reference to FIG.3 and FIG.5, the expansion-contraction body 120 of this embodiment is demonstrated. 5A and 5B are a longitudinal sectional view and a transverse sectional view in a state where the cylindrical wall 121 is contracted (or in a folded state). 5C and 5D are a longitudinal sectional view and a transverse sectional view in a state where the cylindrical wall portion 121 is extended (or in a developed state).

  The stretchable body 120 has a hollow bellows shape, and is configured such that the volume can be changed according to the increase or decrease of the internal pressure of the drain pipe P. The stretchable body 120 is disposed inside the main body 110 and / or the drainage pipe P, and the interior of the stretchable body 120 is not communicated with the inside of the drainage pipe P and is open to the external environment. In the stretchable body 120, the open end 122 at the upper end (one end) is a fixed end, and the closed end at the other end (lower end) is a free end.

  As shown in FIG. 3, the stretchable body 120 includes a hollow cylindrical wall part 121 having an open end 122 at the upper end, a plurality of outer groove parts 124 formed on the outer peripheral wall of the cylindrical wall part 121, and the cylindrical wall part 121. A plurality of inner groove portions 125 formed on the inner peripheral wall of the first and second receiving portions 126 for closing the other end of the cylindrical wall portion 121 in a sealed state. The expansion / contraction body 120 increases or decreases its volume by extending or contracting the cylindrical wall portion 121 in the axial direction so that the groove widths of the outer groove portion 124 and the inner groove portion 125 respectively change. The outer groove portion 124 and the inner groove portion 125 are narrow grooves, and are closed so that the meat portion substantially abuts or contacts (sticks) when the groove width is narrowed. Further, when the distal ends of the outer groove portion 124 and the inner groove portion 125 open (separate) with the base end as an axis, the groove width changes. A hollow portion 121 a that communicates with the external environment (venting portion 115) but is isolated from the internal space 118 (inside the drainage pipe P) is defined inside the cylindrical wall portion 121.

  As shown in FIG. 5A, the outer groove portion 124 is formed by cutting a cylindrical body having a thick peripheral wall (corresponding to a completely folded cylindrical wall portion 121) into a linear shape from the outer surface along the circumferential direction. Was formed. On the other hand, the inner groove portion 125 was formed by cutting a cylindrical body having a thick peripheral wall into a linear shape from the inner surface along the circumferential direction. More specifically, in the stretchable body 120, the outer groove portion 124 is cut from the outer surface leaving the inner peripheral edge portion of the cylindrical wall portion 121, and the inner groove portion 125 is the inner surface leaving the outer peripheral edge portion of the cylindrical wall portion 121. Has been cut from. The plurality of outer groove portions 124 and the plurality of inner groove portions 125 are alternately formed in the axial direction of the cylindrical wall portion 121. That is, the outer groove portion 124 and the inner groove portion 125 are alternately formed as linear cuts extending in the circumferential direction (perpendicular to the axial direction). And in an original form (contraction form), the outer diameter of the cylinder wall part 121 is uniform in the axial direction in the expansion-contraction part.

  An annular plate 127 is defined between the outer groove portion 124 and the inner groove portion 125 as shown in FIG. A plurality of annular plate bodies 127 are continuously provided in the axial direction via peripheral edges that are alternately inside and outside. That is, each annular plate body 127 is connected to the annular plate body 127 adjacent to the upper side (downward) at the inner peripheral edge thereof and connected to the annular plate body 127 adjacent to the lower side (upper side) at the outer peripheral edge thereof. That is, since the cylindrical wall 121 has a linear cut (each groove 124, 125) formed in a thick cylindrical body, the annular plate 127 is in contact (the groove width of each groove 124, 125). Is maintained as the original shape. In other words, as shown in FIG. 5A, in the form in which the annular plate bodies 127 are overlapped and the cylindrical wall 121 is completely contracted (folded), no elastic restoring force is generated. In the form of FIG. 5A, the volume of the stretchable body 120 is minimized.

  Then, each annular plate 127 tilts in the axial direction with the inner peripheral edge and the outer peripheral edge as fulcrums from the contracted state of FIG. 5A, so that the groove widths of the outer groove 124 and the inner groove 125 are expanded. As a result, the entire cylindrical wall 121 extends. That is, the cylindrical wall portion 121 is deformed so that each annular plate 127 is deployed vertically in the initial movement. In this unfolding deformation, the influence of the elastic restoring force can be almost ignored. Strictly speaking, the annular plate 127 is refracted elastically when tilted, but the elastic restoring force is sufficiently small compared to the influence of gravity (except when the cylindrical wall 121 extends excessively). And the cylinder wall part 121 is expanded-contracted in an axial direction by the groove width of the some outer groove part 124 and the inner groove part 125 changing. As shown in FIG. 5C, the outer wall portions 124 and the inner groove portions 125 spread with substantially equal groove widths, so that the cylindrical wall portion 121 extends in the axial direction. At this time, while the annular plate 127 is refracted and inclined in the axial direction, the joint 127a maintains the original shape (horizontal annular plate) as shown in FIG. 5 (d). The outer diameter of the outer edge side joint 127 a indicates the maximum outer diameter of the cylindrical wall portion 121, and the inner diameter of the inner edge side joint 127 a indicates the minimum inner diameter of the cylindrical wall portion 121. Since the outer diameter of the contracted form of the cylindrical wall 121 is substantially equal to (or slightly larger than) the outer diameter of the extended form of the cylindrical wall 121, the gas flow path 119 to the expansion part 116 due to expansion and contraction of the cylindrical wall part 121 is blocked. Will never be done.

  The stretchable body 120 is supported by the support portion 114 so that one end thereof is opened. More specifically, an annular connecting piece 122a is provided at the opening end 122 of the stretchable body 120, and the connecting piece 122a is pressed between the upper surface of the support 114 and the lower surface of the upper wall 112 in a sealed state. That is, the hollow portion 121a communicates with the external environment through the opening end portion 122 and the ventilation portion 115.

  On the other hand, a cup-shaped receiving portion 126 that closes the other end of the cylindrical wall 121 and opens to the other end is attached to the other end of the stretchable body 120. The receiving part 126 has a predetermined weight, and constitutes a part of its own weight of the expansion / contraction body 120. The receiving portion 126 includes a bottom portion 126a that seals the other end of the cylindrical wall portion 121, a standing portion 126b that is erected on the other end side from the bottom portion 126a, and an opening that is edged at a leading edge of the standing portion 126c. 126c. That is, ventilation between the hollow part 121a and the internal space 118 (inside the drain pipe P) is blocked by the cylindrical wall part 121 and the bottom part 126a of the receiving part 126. Further, the receiving part 126 is opened in the same direction as the expansion / contraction direction of the expansion / contraction body 120, thereby effectively receiving the air flow accompanying the pressure fluctuation in the drain pipe P and assisting the expansion / contraction movement. More specifically, the standing portion 126b of the receiving portion 126 collects the upward air flow from the vertically lower side of the drain pipe P through the opening 126c, and the bottom portion 126a is substantially vertically upward on the surface thereof. Receive. That is, since the direction of the ascending air current and the expansion / contraction direction of the cylindrical wall portion 121 are parallel, the receiving portion 126 can effectively receive the force.

  In addition, the cylindrical wall part 121 of the expansion-contraction body 120 of this embodiment is formed from the material which can maintain an original form and has a softness | flexibility of the grade which can be expand | deployed by dead weight. For example, the cylindrical wall portion 121 of the stretchable body 120 can be formed by introducing a cut line with a blade or the like into a thick cylindrical body of rubber material. However, the stretchable body of the present invention is not limited to this, and various materials such as synthetic resins can be employed.

  FIG. 6 is an exploded perspective view of the shock absorber 100. As shown in FIG. 6, in the main body 110, a first member 110A including a peripheral wall 111, a second member 110B including an upper wall 112, and a third member 110C including a fence-like portion 116b are screws (not shown). It is fixed. And the buffering device 100 is assembled by the connection piece 122a of the opening edge part 122 of the expansion-contraction body 120 being narrow-pressed between 110 A of 1st members, and the 2nd member 110B.

  Subsequently, the drainage system 10 in which the shock absorber 100 of the present embodiment is attached to the drainage pipe P will be described with reference to FIGS. 7 and 8. FIG. 7 is an exploded perspective view of the drainage system 10 in which the shock absorber 100 of this embodiment is attached to the branch pipe P2 of the drainage pipe P. FIG. 8A is a cross-sectional view of the drainage system 10 in which the inside of the drainage pipe P is in a natural state. FIG. 8B is a cross-sectional view of the drainage system 10 in which the inside of the drainage pipe P is in a positive pressure state. FIG. 8C is a cross-sectional view of the drainage system 10 in which the inside of the drainage pipe P is in a negative pressure state. The “natural state” means a normal state in which neither significant positive pressure nor negative pressure is generated in the drain pipe P.

  As shown in FIG. 7, in the drainage system 10, the drainage pipe P is attached to the branch pipe P <b> 2 through the joint 113 a of the connection part 113 so that the internal space 118 of the main body 110 communicates with the drainage pipe P. Yes. The joint portion 113a is arbitrarily attached to the opening of the branch pipe P2 so that the diameter of the connection portion 113 is adapted to the diameter of the branch pipe P2. However, if the diameter of the connecting portion 113 corresponds to the diameter of the branch pipe P2, the joint portion 113a can be omitted. Since the inside of the main body 110 and the inside of the joint portion 113a communicate with each other, these are interpreted as an integrated internal space 118. Alternatively, the joint 113a may be regarded as a part of the drain pipe P, and the inside of the joint 113a may be interpreted as the drain pipe P.

  As shown in FIGS. 8A to 8C, in the drainage system 10, the internal space 118 that communicates with the inside of the drainage pipe P is isolated from the external environment. And the expansion-contraction body 120 is arrange | positioned inside the main body 110 so that the inside of the expansion-contraction body 120 (hollow part 121a) may be open | released by the external environment, without communicating with the inside of the drain pipe P. In the present embodiment, the stretchable body 120 is arranged to be stretchable within the range of the internal space 118 of the main body 110. The volume of the internal space 118 of the main body 110 varies according to the expansion / contraction of the expansion / contraction body 120 which is a volume variation body. However, the stretchable body 120 may be disposed so as to extend beyond the joint portion 113a of the main body 110 to the inside of the drain pipe P. In that case, according to the pressure fluctuation inside the drainage pipe P, the volume of the internal space 118 itself of the expansion-contraction body 120 hardly fluctuates, and the volume inside the drainage pipe P fluctuates.

  FIG. 8A shows a state of the shock absorber 100 in which the expansion and contraction body 120 hangs vertically downward by its own weight and is expanded and deformed to a predetermined groove width by gravity. This “self-weight” is the weight of the entire stretchable body 120, and in this embodiment, is the total weight of the cylindrical wall portion 121 and the receiving portion 126. In other words, the receiving portion 126 also functions as a weight, and the initial length due to the weight of the cylindrical wall portion 121 can be adjusted by adjusting the weight. In the natural state of FIG. 8A, the cylinder wall 121 is developed vertically downward so that the outer groove 124 and the inner groove 125 are expanded, and the cylinder wall 121 extends to a predetermined length in the axial direction. This predetermined length is the natural length of the pressure fluctuation buffer device 10 in the natural state, and the cylinder wall 121 is slightly elastically deformed by its own weight, and the elastic force and the own weight of the cylinder wall 121 are balanced. In other words, the stretchable body 120 has an intermediate groove width in a natural state (between a state where the expansion and contraction is widened and a state where the expansion and contraction is completely narrowed), and leaves an extension allowance without completely expanding the groove width. In this way, in the natural state, the stretchable body 120 is in a state of being balanced by gravity with the length, so that it can be easily stretched and deformed quickly in response to fluctuations in the internal pressure of the drain pipe P. That is, the expansion and contraction body 120 operates so as to contract when the inside of the drain pipe P becomes positive pressure and to expand when it becomes negative pressure in order to alleviate the pressure fluctuation inside the drain pipe P.

  In FIG. 8B, the inside of the drain pipe P becomes a positive pressure, the air flow from the drain pipe P is received by the receiving portion 126, and the cylindrical wall portion 121 is contracted in the axial direction from the natural length. That is, when the inside of the drain pipe P becomes a positive pressure, the air inside the expansion / contraction body 120 is discharged to the external environment through the ventilation portion 115, and at the same time, the groove widths 124 and 125 are narrowed, and the expansion / contraction body 120 contracts. Yes. Thus, by reducing the volume of the expansion / contraction body 120, the sum total of the volumes inside the internal space 118 and the drain pipe P is increased, and the pressure rise inside the drain pipe P is alleviated. In the contraction motion of the shock absorber 100, the cylindrical wall 121 is folded against gravity, and no elastic force (elastic force) is generated during contraction. Therefore, unlike the conventional elastically deformable bellows-like member, the expansion / contraction body 120 does not require a force for the initial movement of the elastic deformation and quickly contracts and deforms in response to the generation of positive pressure inside the drain pipe P. Is possible. Then, after the positive pressure inside the drain pipe P is eliminated, the natural length of FIG. 8A is restored by gravity instead of the elastic restoring force from the contracted form of FIG. 8B.

  In FIG.8 (c), the drain pipe P inside becomes a negative pressure, the airflow to the drain pipe P generate | occur | produces, and the cylinder wall part 121 is extended in the axial direction from natural length. That is, when the inside of the drain pipe P becomes a negative pressure, outside air is introduced into the expansion / contraction body 120 through the ventilation portion 115, and at the same time, the groove widths 124 and 125 are expanded, and the expansion / contraction body 120 is expanded. Thus, when the volume of the expansion-contraction body 120 increases, the sum total of the volume inside the interior space 118 and the drain pipe P decreases, and the pressure drop inside the drain pipe P is alleviated. And in the expansion | extension exercise | movement of this buffer device 100, the expansion-contraction body 120 expand | extends below against elastic return force. At this time, since the cylindrical wall portion 121 is elastically deformed and balanced by its own weight in a natural state, it can be expanded with a slight force, and is expanded and deformed in quick response to the generation of negative pressure inside the drain pipe P. It is possible. Then, after the negative pressure inside the drain pipe P is eliminated, the natural length of FIG. 8A is restored by the elastic restoring force from the extended form of FIG. 8C.

  In the shock absorber 100 of this embodiment, an additional shock absorber 100 ′ having the same configuration can be continuously provided via the expansion portion 116 in order to expand the pressure fluctuation buffer performance. FIG. 9 is a schematic view showing a pressure fluctuation buffer structure 11 in which an additional buffer device 100 ′ is connected to the buffer device 100 of the present embodiment to expand the pressure fluctuation buffer performance. FIG. 10 is a partially enlarged view of the pressure fluctuation buffer structure 11.

  As shown in FIGS. 9 and 10, in the pressure fluctuation buffer structure 11, the expansion portion 116 of the shock absorber 100 is connected so that the internal space 118 of the shock absorber 100 communicates with the internal space 118 ′ of the additional shock absorber 100 ′. The connecting portion 113 ′ (joint portion 113a ′) of the additional shock absorber 100 ′ is connected in series. Then, the extension part 116 ′ of the additional shock absorber 100 ′ is closed by the blocking part 117. That is, the two telescopic bodies 120 and 120 ′ can be expanded and contracted in the internal spaces 118 and 118 ′ communicating with the inside of the drain pipe P, and the variable volume in the entire space communicating with the inside of the drain pipe P is doubled. Thereby, the pressure fluctuation buffer structure 11 has higher pressure fluctuation buffer performance. In addition, in the pressure fluctuation buffer structure 11 of this embodiment, only one additional shock absorber 100 ′ is added. However, if higher pressure fluctuation buffer performance is required, a plurality of additional shock absorbers 100 ′ are added. May be. In this case, the expansion part 116 ′ of the end additional shock absorber 100 ′ is blocked by the blocking part 117.

  Further, the shock absorber 100 is further provided with a reduced-diameter joint 130 that is attached to the expansion portion 116 and that can connect the connecting portion 113 ′ of the additional shock absorber 100 ′. The different diameter joint 130 has a first connecting port 131 having a small diameter connected to the expansion portion 116 and a second connecting port 132 having a large diameter connected to the connecting portion 113 ′ (joint portion 113 a ′). The first connection port 131 and the second connection port 132 are misaligned and are not arranged concentrically. Specifically, the center of the first connection port 131 matches the center of the cylindrical portion 116 c of the expansion portion 116, and the center of the second connection port 132 matches the center of the connection portion 113. Thereby, like the pressure fluctuation buffer structure 11 shown in FIG. 9, the telescopic body 120 of the buffer device 100 and the telescopic body 120 'of the additional buffer device 100' are linearly aligned in the vertical direction. That is, the pressure fluctuation buffer structure 11 maintains a vertically long and compact form that does not spread laterally. This is the same when a plurality of additional shock absorbers 100 'are added.

  Furthermore, as shown in FIG. 10, a gas flow path 119 that continues from the connection portion 113 to the expansion portion 116 is provided between the inner surface of the peripheral wall 111 of the main body 110 and the outer surface of the stretchable body 120. Through the gas flow path 119, the internal space 118 of the shock absorber 100 and the internal space 118 'of the additional shock absorber 100' communicate with each other. The minimum width of the gas flow path 119 is a distance between the inner surface of the peripheral wall 111 and the outer periphery of the receiving portion 126. Further, at the time of expansion and contraction of the cylindrical wall portion 121, at least the minimum width of the gas flow path 119 is ensured without the gas flow path 119 being closed. That is, even when at least one additional shock absorber 100 ′ is added to the shock absorber 100, the inside of the additional shock absorber 100 ′ is not affected by the volume increase of the telescopic body 120 from the internal space 118 of the shock absorber 100. It is possible to maintain a constant air flow into the space 118 ′ and exhibit stable pressure fluctuation buffering performance. Even if the receiving portion 126 is omitted, the outer diameter of the contracted tubular wall 121 is substantially equal to the outer diameter of the expanded tubular wall 121, so that the gas flow path 119 is blocked when the telescopic body 120 is expanded and contracted. Without being substantially constant.

  Hereinafter, the effect in the buffer device 100 (the expansion-contraction body 120, the drainage system 10) of one Embodiment which concerns on this invention is demonstrated.

  According to the shock absorber 100 of the present embodiment, the cylindrical wall portion 121 is axially arranged so that the groove widths of the outer groove portion 124 and the inner groove portion 125 of the expansion / contraction body 120 are changed to alleviate the pressure fluctuation inside the drain pipe P. Elongates or contracts. In particular, in the stretchable body 120, the outer groove portion 124 is cut from the outer surface leaving the inner peripheral edge portion of the cylindrical wall portion 121, and the inner groove portion 125 is cut from the inner surface leaving the outer peripheral edge portion of the cylindrical wall portion 121. It is included. That is, since the groove portions 124 and 125 are formed of cuts, the original shape is maintained in a form in which the cylindrical wall portion 121 is completely contracted so that the groove width is substantially zero. And the volume of the said expansion-contraction body 121 increases by the cylinder wall part 121 being expand | deployed to an expansion | extension direction from this contraction form. That is, the expansion / contraction body 120 can be expanded and contracted with a slight force. Furthermore, in the present embodiment, in a natural state where the inside of the drain pipe P is not positive pressure or negative pressure, the stretchable body 120 hangs down by its own weight, and is stretched and deformed to a predetermined groove width by gravity. In this natural state, since the expansion / contraction body 120 is in a state of being balanced by gravity, the expansion / contraction deformation is freely possible by quickly responding to fluctuations in the internal pressure of the drain pipe P. Therefore, the shock absorber 100 of the present embodiment can quickly and stably respond to the positive pressure and / or negative pressure inside the drain pipe P, and can reduce pressure fluctuation.

  Further, in the conventional bellows-like member (bellows molded product), in the initial form, adjacent bellows ridges are separated from each other, and the groove width is relatively large. Then, after the bellows-like member is elastically deformed from the initial form, the elastic restoring force increases as the variation in the groove width increases. Therefore, a corresponding pressure is required to sufficiently change the groove width. That is, in the bellows-shaped member, when the pressure fluctuation in the conventional drainage pipe P changes, the elastic restoring force increases as the groove width fluctuation amount increases. The pressure could not be relaxed sufficiently. On the other hand, this expansion-contraction body 120 expands and contracts when the cylindrical wall 121 is expanded or folded in the axial direction via the groove. In other words, unlike the conventional elastically deformable bellows molded product, the present stretchable body 120 uses not only elastic deformation but deployment deformation as the main principle of expansion and contraction. Therefore, the range (movable range) that can be expanded and contracted with a small pressure is relatively large. That is, the shock absorber 100 and the expansion / contraction body 120 of the present embodiment can sufficiently expand and contract with respect to the pressure fluctuation inside the drain pipe P, and can more reliably reduce the pressure fluctuation.

  According to the shock absorber 100 of the present embodiment, the stretchable body 120 is disposed inside the main body 110 so that the interior of the stretchable body 120 is not communicated with the interior of the drain pipe P and is opened to the external environment. Since the expansion body 120 is arranged so as not to be exposed to the external environment as described above, the expansion body 120 is protected from the external environment, and the outer shape or appearance of the shock absorber 100 is kept compact regardless of the expansion / contraction of the expansion body 120. Can do.

  The present invention is not limited to the above-described embodiment, and can take various embodiments. Hereinafter, another embodiment of the present invention will be described. In the description of each example, the description of the components common to the first embodiment is omitted, but members having the same two-digit code among the elements indicated by three digits are generally the same or similar. Means a member.

[Embodiment 2]
FIG. 11 is a schematic diagram of the shock absorber 200 according to the second embodiment. As shown in FIG. 11, in the shock absorber 200, the stretchable body 220 is supported by the main body 210 so as to hang down under its own weight in the external environment of the drain pipe P. The structure of the cylindrical wall portion 221, the outer groove portion 224 and the inner groove portion 225 of the stretchable body 220 is the same as that of the stretchable body 120.

  In the shock absorber 200 of the second embodiment, in contrast to the shock absorber 100 of the first embodiment, the inside of the stretchable body 220 communicates with the internal space 218 of the main body 210 and the inside of the drain pipe P, and is isolated from the external environment. Has been. Therefore, the stretchable body 220 is extended when the inside of the drain pipe P becomes positive pressure. That is, when the inside of the drain pipe P becomes negative pressure, the air inside the expansion body 220 is discharged into the drain pipe P, and at the same time, the groove width is narrowed and the expansion body 220 contracts. On the other hand, when the inside of the drain pipe P becomes a positive pressure, the air is introduced into the stretchable body 220 and, at the same time, the groove width widens, and the stretchable body 220 extends.

  That is, in the buffer device 200 of the present embodiment, the volume of the space communicating with the inside of the drain pipe P varies according to the fluctuation of the internal pressure of the drain pipe P, and the positive pressure and the negative pressure of the drain pipe P are alleviated. Moreover, in the said buffering device 200, since the expansion-contraction body 220 can expand-contract when it expand | deploys and superimposes, the pressure fluctuation in the drain pipe P can be relieved rapidly and stably (similar to the buffering device 100). it can.

[Embodiment 3]
FIG. 12 is a schematic diagram of the shock absorber 300 according to the third embodiment. The structure of the cylindrical wall part 321, the outer groove part 324, and the inner groove part 325 of the elastic body 320 of the shock absorber 300 in FIG. 12 is the same as that of the elastic body 120. In the natural state, the free end (closed end) of the expansion / contraction body 320 is located above, and the fixed end (open end 322) is located below. The stretchable body 320 is completely folded and contracted by gravity in a natural state. As shown by the phantom line in FIG. 12, when the inside of the drain pipe P becomes positive pressure, the cylindrical wall portion 321 is expanded upward and extended against gravity.

  That is, in the shock absorber 300 of the present embodiment, the volume of the space communicating with the drain pipe P increases as the internal pressure of the drain pipe P increases, and the positive pressure of the drain pipe P is relaxed. Moreover, in the said buffering device 300, since the expansion-contraction body 320 can expand-contract by expansion | deployment and superimposing deformation, it can reduce the pressure fluctuation in the drain pipe P quickly and stably (similar to the buffering device 100). it can.

  The present invention is not limited to the above-described embodiments and modifications, and can be implemented in various modes as long as they belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Drainage system 11 Pressure fluctuation buffer structure 100 Shock absorber 110 Main body 111 Perimeter wall 112 Upper wall 113 Connection part 114 Support part 115 Ventilation part 116 Expansion part 117 Blocking part 118 Internal space 119 Gas flow path 120 Stretch body 121 Cylindrical wall part 122 Open end Portion 124 Outer groove portion 125 Inner groove portion 126 Receiving portion 127 Annular plate 130 Reducing joint 100 'Additional shock absorber P Drain pipe P1 Drain main pipe P2 Branch pipe

Claims (7)

A shock absorber attached to a drain pipe to alleviate fluctuations in the internal pressure of the drain pipe,
A stretchable body having a variable volume according to an increase or decrease in the internal pressure of the drain pipe,
The stretchable body includes a hollow cylindrical wall portion having one end opened and the other end closed, a plurality of outer groove portions cut from an outer surface along a circumferential direction of the cylindrical wall portion, and the cylindrical wall portion. A plurality of inner grooves cut from the inner surface along the circumferential direction of the outer wall, the outer grooves and the inner grooves are alternately formed in the axial direction of the cylindrical wall portion, and the groove width of each outer groove And the buffer width characterized by the groove width of each said inner groove part changing, and the said expansion-contraction body expands-contracts to an axial direction.   The telescopic body is disposed inside the shock absorber main body and / or the drain pipe, and the telescopic body interior is open to the outside environment without communicating with the drain pipe interior, The shock absorber according to claim 1, wherein the stretchable body contracts when a positive pressure is reached.   2. The stretchable body according to claim 1, wherein the stretchable body hangs down by its own weight so that the other end of the cylindrical wall portion is positioned vertically downward in a natural state, and extends with a predetermined length while leaving a margin for extension. 2. The shock absorber according to 2.   The said expansion-contraction body is equipped with the cup-shaped receiving part opened to the other end side so that the other end of the said cylinder wall part might be obstruct | occluded and to receive the airflow from the said drain pipe. The shock absorber according to any one of the above.   The stretchable body is disposed in an external environment of the drainage pipe, and the inside of the stretchable body communicates with the inside of the drainage pipe, and the stretchable body extends when the inside of the drainage pipe becomes positive pressure. The shock absorber according to claim 1. A telescopic body attached to a drain pipe, the volume of which can vary according to fluctuations in the internal pressure of the drain pipe,
A hollow cylindrical wall having one end open and the other end closed;
A plurality of outer grooves cut from the outer surface along the circumferential direction of the cylindrical wall,
A plurality of inner grooves cut from the inner surface along the circumferential direction of the cylindrical wall portion,
The outer groove portion and the inner groove portion are alternately formed in the longitudinal direction of the cylindrical wall portion, and the groove width of the outer groove portion and the groove width of the inner groove portion vary to expand and contract in the axial direction. body. A drainage pipe comprising a drainage main pipe for flowing wastewater, and a branch pipe connected to the drainage main pipe;
A drainage system comprising: the shock absorber according to any one of claims 1 to 5 attached to the branch pipe.

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