JP7628410B2 - Check valve device for rehabilitating pipes - Google Patents

Description

The present invention relates to a check valve device that allows fluid to flow in one direction and prevents it from flowing in the opposite direction, and in particular to a check valve device that is installed in a rehabilitation pipe that is lined on the inner circumference of an aging buried pipe.

As a countermeasure against deterioration of buried pipes such as sewer pipes buried underground, a rehabilitation method is known in which the inside circumference of the deteriorated buried pipe is lined with a rehabilitation pipe. A backfill material such as mortar is injected into the annular gap between the buried pipe and the rehabilitation pipe. Furthermore, weep holes are sometimes provided in the pipe wall of the rehabilitation pipe to prepare for an increase in water pressure underground.

For example, Patent Documents 1 to 3 disclose a check valve device that can be used both for injecting backfill material and as a weep hole. The check valve device is installed so as to penetrate the pipe wall of a lined rehabilitated pipe. An injection hose is connected to the check valve device from inside the rehabilitated pipe. Backfill material is discharged from the injection hose. The check valve device is opened by the discharge pressure of the backfill material, and the backfill material is injected into the gap between the buried pipe and the rehabilitated pipe. When the injection is completed and the application of the discharge pressure is stopped, the check valve device is closed by the elastic force of the built-in elastic member. This prevents backflow of the backfill material during the curing period. Furthermore, the valve unit in the check valve device, which includes the valve seat member, valve body, and the elastic member, can be detached from the device housing and can be installed in the opposite direction. By installing it backwards, when underground water pressure rises, the check valve device opens due to the water pressure and functions as a weep hole, allowing underground water to escape into the rehabilitated pipe. On the other hand, when the internal pressure of the rehabilitated pipe increases, the check valve device closes. This prevents fluids such as sewage inside the rehabilitated pipe from flowing out to the outside of the pipe wall.

JP 2015-243507 A JP 2016-024972 A JP 2017-128318 A

This type of check valve device is designed to control the flow of liquids and gases such as water and air, and if the fluid to be controlled contains solid particles such as pebbles with a very small particle size (for example, a particle size of about 1 mm or less), the solid particles are likely to become trapped between the valve seat and the valve body, making it impossible to completely close the valve.
The present invention has been made in consideration of the above circumstances, and aims to provide a check valve device that can stably maintain the check valve function even if the fluid to be controlled contains solid particles with a small particle size.

In order to solve the above problems, the present invention provides a check valve device provided in a rehabilitation pipe lined on the inner circumference of an underground buried pipe,
a cylindrical body provided in an attachment hole penetrating a pipe wall of the rehabilitation pipe;
a valve seat member having an annular valve seat surface disposed within the body;
a valve body having an annular seating surface that is seated and released on the valve seat surface and engaged with the valve seat member via a connecting means;
an elastic member that biases the valve body in a seating direction,
The valve seat surface has a curvature along an inward/outward direction connecting its outer periphery and its inner periphery, and a curvature of the seating surface along an inward/outward direction connecting its outer periphery and its inner periphery is different from each other.

According to this check valve device, the curvature of the valve seat surface and the curvature of the seating surface are different from each other, so that when the valve is closed, the valve seat surface and the seating surface are in almost line contact. Therefore, even if the fluid to be controlled contains solid particles with a small particle size, the solid particles are less likely to become trapped between the valve seat surface and the seating surface compared to the case of surface contact. This prevents the check valve device from becoming unable to close, and allows the function as a check valve to be stably maintained.

Preferably, the valve seat surface is a concave curved surface recessed in a thickness direction of the valve seat member toward the inner periphery, and the seating surface is a convex curved surface having a smaller radius of curvature than the valve seat surface along the inward/outward direction, thereby allowing fluid to flow smoothly between the valve seat surface and the seating surface when the valve is open, thereby suppressing pressure loss.
More preferably, the valve seat surface is partially concave spherical, and the seating surface is annular and convex with a smaller radius of curvature than the valve seat surface along the inward and outward direction, so that even if the valve disc is slightly tilted or deformed, the seating surface can be in close contact with the valve seat surface over the entire circumference when seated, and the valve can be closed reliably.

the connecting means includes a connecting shaft member that is joined to the valve body and that penetrates the valve seat member to protrude toward an opposite side to the valve body, and a locking plate that is provided on a protruding end of the connecting shaft member,
the elastic member is formed in an annular shape and fitted around an outer periphery of at least a portion of the connecting shaft member between the locking plate and the valve seat member to apply an elastic force so as to separate the locking plate and the valve seat member,
It is preferable that the locking plate is made of rubber or resin which is harder than the elastic member.
By making the locking plate out of rubber or resin, corrosion of the locking plate can be suppressed and malfunctions due to corrosion can be prevented for a long period of time. By making the locking plate out of hard material, the elastic force of the elastic member can be reliably received.

The elastic member may cover the entire outer periphery of the connecting shaft member from the locking plate to the valve body. This allows the elastic member to function as a coating material to prevent corrosion of the connecting shaft member.

It is preferable that a notch recess is formed on the edge of the opening at the end of the body facing the outside of the rehabilitation pipe. This allows the notch recess to function as a fluid inlet and outlet in addition to the opening at the outer end of the body. Therefore, even if the fluid to be controlled is a highly viscous fluid such as concrete or mortar, it is possible to reduce flow resistance when entering and exiting the body, and improve flow.

It is preferable that a flange protruding radially outward from the body is formed at the end of the body facing the inside of the rehabilitating pipe, and that the flange is formed with a threaded hole through which a bolt for fixing to the rehabilitating pipe can be passed.
This allows the check valve device to be firmly fixed to the rehabilitation pipe with bolts, and therefore prevents the check valve device from shifting position, even if the fluid to be controlled is a fluid with a high specific gravity such as concrete or mortar, and allows the check valve to stably maintain its function.
Incidentally, if the check valve device is attached to the rehabilitated pipe simply by fitting or gluing it into a mounting hole in the pipe wall of the rehabilitated pipe, the check valve device is likely to become misaligned, especially if the specific gravity of the fluid to be controlled is high.

It is preferable that an elastic packing is interposed between the flange and the inner peripheral surface of the rehabilitation pipe.
As a result, even if the inner peripheral surface of the rehabilitating pipe is a cylindrical concave surface, while the back surface of the flange that comes into contact with the rehabilitating pipe is a flat surface, the elastic packing sandwiched between the flange and the rehabilitating pipe is elastically deformed, so that the space between the flange and the rehabilitating pipe can be completely filled with the elastic packing. Therefore, it is possible to prevent fluid from leaking between the flange and the rehabilitating pipe. For example, by preventing leakage of backfill material from the gap between the buried pipe and the rehabilitating pipe, it is possible to prevent the formation of a cavity in the gap between the pipes.
The elastic packing is preferably a porous elastic packing having closed cells.

It is preferable that a female thread is formed on an inner peripheral surface of the body, and a male thread is formed on an outer peripheral surface of the valve seat member to be screwed into the female thread.
This makes it possible to prevent the valve seat member from shifting from the body or falling off, and also makes it possible to attach and detach the valve seat member from the body.

a first surface of the valve seat member facing an outside of the rehabilitating pipe and a second surface of the valve seat member facing an inside of the rehabilitating pipe each constitute the valve seat surface,
It is preferable that the valve body be selectively disposable in either a first position facing the first surface or a second position facing the second surface.
By disposing the valve in the first position, it is possible to allow the flow of fluid from the inside to the outside of the rehabilitated pipe while preventing the flow of fluid from the outside to the inside of the rehabilitated pipe. Therefore, it is possible to inject a fluid such as a backfill material into the annular gap between the buried pipe and the rehabilitated pipe while preventing the backfill material from flowing back.
By placing the valve body in the second position, it is possible to allow the flow of fluid from the outside to the inside of the rehabilitated pipe, while preventing the flow of fluid from the inside to the outside of the rehabilitated pipe. Therefore, for example, when groundwater pressure rises after the rehabilitated pipe is put into service, groundwater can be released into the rehabilitated pipe, reducing the water pressure applied to the rehabilitated pipe. It is also possible to prevent fluids such as sewage flowing through the rehabilitated pipe from leaking out of the rehabilitated pipe. The orientation of the valve seat member can be left as it is, and only the orientation of the valve body can be changed.

The check valve device of the present invention can stably maintain its function as a check valve even if the fluid to be controlled contains fine solid particles.

FIG. 1 is a side cross-sectional view taken along line II in FIG. 2, showing a buried pipe rehabilitation method using a check valve device according to a first embodiment of the present invention, during the process of installing the check valve device in a rehabilitation pipe. FIG. 2 is a front cross-sectional view taken along line II-II in FIG. FIG. 3 is an exploded perspective view of a valve unit of the check valve device. FIG. 4 is an enlarged cross-sectional view of the circle IV in FIG. FIG. 5 is a side cross-sectional view showing the rehabilitation method in the backfilling material injection step. FIG. 6 is a cross-sectional view of the buried pipe during the injection process. FIG. 7 is a side cross-sectional view showing the rehabilitation method in a backfilling material curing step. FIG. 8 is a side cross-sectional view showing an example of a rehabilitated buried pipe in service. FIG. 9 is a side cross-sectional view showing a check valve device according to a second embodiment of the present invention, attached to a rehabilitation pipe. FIG. 10 is a side cross-sectional view showing a check valve device according to a third embodiment of the present invention, in a state where it is attached to a rehabilitation pipe. FIG. 11 is a side cross-sectional view showing the check valve device according to the second embodiment when the backfilling material is injected.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First embodiment (FIGS. 1 to 8)
Fig. 6 shows the process of rehabilitating an old buried pipe 1, such as an underground sewer pipe. The inner circumference of the buried pipe 1 is lined with a rehabilitation pipe 3. An annular inter-pipe gap 2 is formed between the buried pipe 1 and the rehabilitation pipe 3. The inter-pipe gap 2 is filled with a backfill material 4, such as mortar or concrete.
The buried pipe 1 is not limited to a sewer pipe, but may be a water supply pipe, an agricultural water pipe, a hydroelectric power generation water pipe, a gas pipe, a tunnel, or the like.

1 , a check valve device 5 is provided in a pipe wall 3w of a rehabilitation pipe 3. The check valve device 5 includes a cylindrical body 10 and a valve unit 19.
The body 10 is made of a hard resin such as polyvinyl chloride (PVC) etc. The body 10 includes a cylindrical portion 11 and a flange 12 at the base end of the cylindrical portion 11 .

The tubular portion 11 is formed in a cylindrical shape with both ends (base end and tip end) open. The axis of the tubular portion 11, and therefore the axis _L5 of the check valve device 5, are oriented so as to be perpendicular (intersect) with the pipe axis _L3 of the rehabilitating pipe 3. The base end (lower end in FIG. 1) of the tubular portion 11 is oriented toward the inside of the rehabilitating pipe 3, and the tip end (upper end in FIG. 1) is oriented toward the outside of the rehabilitating pipe 3. An opening 11b is formed at the base end of the tubular portion 11. An opening 11a is formed at the tip end of the tubular portion 11.

The outer peripheral surface of the tube portion 11 is tapered, with the diameter decreasing toward the tip. Moreover, between the axial middle portion of the tube portion 11, the outer peripheral surface on the base end side (lower side in FIG. 1) is a gently tapered portion 11d, and the outer peripheral surface on the tip end side (upper side in FIG. 1) is a steeply tapered portion 11e.

A partition convex portion 14 is formed in the axial middle portion of the inner peripheral surface of the cylindrical portion 11. The partition convex portion 14 protrudes radially inward from the cylindrical portion 11 and is formed in an annular shape along the circumferential direction of the cylindrical portion 11. The partition convex portion 14 divides the inside of the cylindrical portion 11 and the inside of the body 10 into a fluid inlet/outlet chamber 10a on the tip side of the partition convex portion 14 and a valve storage chamber 10b on the base end side of the partition convex portion 14. The inner peripheral surface of the fluid inlet/outlet chamber 10a is formed in a tapered shape that expands toward the tip end (the upper end in FIG. 1). The fluid inlet/outlet chamber 10a is connected to the opening 11a at the tip. A female thread 15 is formed on the inner peripheral surface of the valve storage chamber 10b. The valve storage chamber 10b is connected to the opening 11b at the base end (the end facing the inside of the rehabilitation pipe 3).

A number of notched recesses 13 are formed in the portion of the tubular portion 11 that is closer to the tip than the intermediate portion. The multiple notched recesses 13 are spaced apart in the circumferential direction of the tubular portion 11. Each notched recess 13 is recessed in a U-shape along the axis of the tubular portion 11 from the edge of the opening 11a at the tip of the tubular portion 11 (the end facing the outside of the rehabilitation pipe 3). It also penetrates from the outer peripheral surface to the inner peripheral surface of the tubular portion 11 and is connected to the fluid inlet/outlet chamber 10a.

A flange 12 is provided at the base end of the tubular portion 11 (the end facing the inside of the rehabilitation pipe 3). The flange 12 is formed in an annular plate shape and protrudes radially outward from the tubular portion 11. A plurality of screw holes 12b are formed in the flange 12. Each screw hole 12b penetrates the flange 12 in the thickness direction (axial direction of the body 10). The multiple screw holes 12b are arranged at intervals from one another in the circumferential direction of the flange 12.

The body 10 and therefore the check valve device 5 are installed in the rehabilitation pipe 3 as follows.
As shown in Fig. 1, a mounting hole 3h is formed so as to pass through a pipe wall 3w of the rehabilitating pipe 3. A tubular portion 11 is inserted into the mounting hole 3h. The tip of the tubular portion 11 protrudes outward from the pipe wall 3w and is positioned within the inter-pipe gap 2. A flange 12 is fitted to the inner peripheral surface of the rehabilitating pipe 3 around the mounting hole 3h.

1 and 2, an elastic packing 17 is interposed between the flange 12 and the inner circumferential surface of the rehabilitating pipe 3. The elastic packing 17 is preferably composed of a sponge-like (single-porous) elastic packing with closed cells. The elastic packing 17 is formed in a circular plate shape that matches the shape and dimensions of the flange 12. A plurality of screw holes 17b are formed in the elastic packing 17. The screw holes 12b of the flange 12 and the screw holes 17b of the elastic packing 17 overlap one-to-one. A bolt 18 is passed through the overlapping screw holes 12b, 17b. The check valve device 5 is fixed to the rehabilitating pipe 3 by screwing the bolt 18 into the rehabilitating pipe 3. As shown in FIG. 2, the elastic packing 17 is elastically deformed to completely fill the gap between the inner circumferential surface 3a, which is a cylindrical concave surface of the rehabilitating pipe 3, and the back surface 12d, which is a flat surface of the flange 12, depending on the difference in the surface shape between these surfaces 3a and 12d.

1, a valve unit 19 is accommodated in the valve accommodating chamber 10b of the body 10. The valve unit 19 includes a valve seat member 20, a valve body 30, and a connecting means 40.
The material of the valve seat member 20 is a hard resin such as PVC. The valve seat member 20 is formed in a generally disk shape whose axis coincides with that of the body 10. Moreover, the valve seat member 20 is inverted symmetrically in the axial direction.

More specifically, as shown in FIG. 3, the valve seat member 20 integrally comprises a valve seat portion 21, a pivotal support portion 22, and four (multiple) connecting arms 23. The valve seat portion 21 is formed in a circular ring shape concentric with the body 10, and a small cylindrical pivotal support portion 22 is disposed at the center. The connecting arms 23 extend radially to connect the pivotal support portion 22 and the valve seat portion 21. A valve passage 24 is formed between the valve seat portion 21 and the pivotal support portion 22. The valve passage 24 is divided into four (multiple) passages by the connecting arms 23.

As shown in Fig. 1, the first surface 21a of the valve seat portion 21 facing the outside of the rehabilitating pipe 3 and the second surface 21b facing the inside of the valve seat portion 21 each constitute a valve seat surface 25. These valve seat surfaces 25 are annular over the entire circumference of the valve seat member 20, and are formed as concave curved surfaces that are concave in the thickness direction (axial direction) of the valve seat portion 21 as they approach the inner periphery. As shown in Fig. 4, the valve seat surface 25 is preferably a partial concave spherical surface with a large radius of curvature R ₂₅ centered on the axis L ₅ .

1, a male thread 26 is formed on the outer circumferential surface of the valve seat member 20. The male thread 26 is screwed into the female thread 15 of the body 10. Since the valve seat member 20 is inversion symmetrical, it can also be attached to the body 10 by being inverted in the axial direction. In other words, the valve seat member 20 is reversible with respect to the body 10.
In this specification, even when the valve seat portion 21 is inverted, the surface facing the outside of the rehabilitating pipe 3 is referred to as a first surface 21a, and the surface facing the inside is referred to as a second surface 21b.

As shown in FIG. 1, the valve body 30 is engaged with the valve seat member 20 via a connecting means 40. As shown in FIG. 3, the valve body 30 is formed in a disk shape concentric with the valve seat member 20. The material of the valve body 30 is a hard resin such as PVC.

As shown in FIG. 1, the corner formed by the front surface (the surface facing the connecting arm 23) and the outer peripheral surface of the valve body 30 constitutes the seating surface 35. The seating surface 35 is annular over the entire circumference of the valve body 30, and is a convex curved surface with a partially circular cross section. In other words, the seating surface 35 is convex along the inward-outward direction connecting the inner and outer peripheries.

4, the curvature of the valve seat surface 25 in the inward/outward direction (radial direction) connecting the outer periphery and the inner periphery is different from the curvature of the seating surface 35 in the inward/outward direction (radial direction) connecting the outer periphery and the inner periphery. Preferably, the seating surface 35 is a convex curved surface having a smaller radius of curvature R ₃₅ (<R ₂₅ ) than the valve seat surface 25 in the inward/outward direction. Preferably, the ratio of the radius of curvature R ₂₅ of the valve seat surface 25 to the radius of curvature R ₃₅ of the seating surface 35 is R ₂₅ :R ₃₅ = 10:1 to 50:1.
As shown in FIGS. 1 and 5 , the seating surface 35 is seated on and separated from the valve seat surface 25 to open and close the check valve device 5 .

Due to the inversion symmetric structure of the valve seat member 20, the valve element 30 can be selectively disposed in either a first position ( FIG. 1 ) where it faces the valve seat surface 25 of the first surface 21 a of the valve seat member 20, or a second position ( FIG. 8 ) where it faces the valve seat surface 25 of the second surface 21 b of the valve seat member 20. In other words, the valve element 30 is reversible with respect to the valve seat member 20.
In the following description, unless otherwise specified, the valve body 30 is assumed to be in the first position (the same applies to other embodiments).

As shown in FIG. 3, the connecting means 40 between the valve seat member 20 and the valve body 30 includes a connecting shaft member 41 and a locking plate 42 as a washer. The connecting shaft member 41 is made of a bolt. As shown in FIG. 1, the tip of the connecting shaft member 41 is screwed into the female thread 34 in the center of the valve body 30, thereby joining the valve body 30. The connecting shaft member 41 penetrates the valve seat member 20 by being passed through the shaft support portion 22. The head 41a of the connecting shaft member 41 protrudes toward the base end side of the check valve device 5 (the opposite side to the valve body 30, the lower side in FIG. 1) beyond the valve seat member 20. The head 41a (protruding end) of the connecting shaft member 41 is provided with a locking plate 42. The locking plate 42 is made of rubber or resin that is harder than the elastic member 50 described later.

As shown in FIG. 1, an elastic member 50 is provided on the outer periphery of the connecting shaft member 41 between the locking plate 60 and the valve seat member 20. The elastic member 50 is made of rubber. The elastic member 50 has a central shaft hole 50a and is formed in a cylindrical (annular) shape. The connecting shaft member 41 is inserted into the central shaft hole 50a.

The base end (the lower end in FIG. 1) of the elastic member 50 abuts against the head 41a via the locking plate 42. The locking plate 42 is interposed between the elastic member 50 and the head 41a and functions as a washer. The tip end of the elastic member 50 abuts against the pivot support portion 22. This causes the elastic member 50 to apply an elastic force to separate the locking plate 60 and the valve seat member 20. As a result, the valve body 30 is biased in the seating direction. For this reason, the check valve device 5 is normally closed.
1, when the valve body 30 is in the first position, the check valve device 5 attached to the rehabilitating pipe 3 prevents the flow of fluid from the outside to the inside of the rehabilitating pipe 3. As shown in Fig. 5, when the fluid pressure from the inside of the rehabilitating pipe 3 exceeds the set pressure set by the elastic member 50, the valve body 30 is unseatable and opens, allowing the flow of fluid from the inside to the outside of the rehabilitating pipe 3.
8, when the valve body 30 is in the second position, the flow of fluid from the inside to the outside of the rehabilitating pipe 3 is prevented. When the fluid pressure from the outside of the rehabilitating pipe 3 exceeds the set pressure set by the elastic member 50, the valve body 30 is unseatable and opens, allowing the flow of fluid from the outside to the inside of the rehabilitating pipe 3.

Using the check valve device 5 having such a structure, the buried pipe 1 is rehabilitated as follows.
As shown in Figures 1 and 2, a rehabilitation pipe 3 is lined around the inner periphery of a buried pipe 1. An installation hole 3h is formed at a predetermined position in a pipe wall 3w of the rehabilitation pipe 3. Furthermore, a check valve device 5 is prepared. The valve body 30 is disposed on the first surface 21a side. The check valve device 5 is installed in the installation hole 3h.
1 , the cylindrical portion 11 is inserted into the mounting hole 3h from inside the rehabilitating pipe 3, and the flange 12 is placed against the inner circumferential surface of the rehabilitating pipe 3 around the mounting hole 3h. An elastic packing 17 is sandwiched between the inner circumferential surface of the rehabilitating pipe 3 and the flange 12. The flange 12 is then fixed to the pipe wall 3w of the rehabilitating pipe 3 with bolts 18.
5 and 6, an injection nozzle 6 is connected to the opening 11b of the cylindrical portion 11. The check valve device 5 serves as an injection saddle for connection of the injection nozzle 6.

6, backfilling material 4 such as mortar is discharged from injection nozzle 6. The discharge pressure causes valve body 30 to lift off against the elastic force of elastic member 50. This opens check valve device 5. Elastic member 50 is compressed and deformed.
The backfilling material 4 flows into the fluid inlet/outlet chamber 10a through the gap between the seating surface 35 of the unseated valve body 30 and the valve seating surface 25. The valve seating surface 25 is a concave curved surface, and the seating surface 35 is a convex curved surface with a smaller radius of curvature than the valve seating surface 25, so that the flow of the backfilling material 4 can be made smooth and pressure loss can be suppressed. The backfilling material 4 is injected into the inter-pipe gap 2 from the opening 11a and also from the side notched recess 13, and is widely diffused in the inter-pipe gap 2. Therefore, the injection resistance can be reduced, and a stable injection operation can be performed even with a highly viscous fluid such as mortar.
The diameter of the injection nozzle 6 and the check valve device 5 is preferably 25A, 50A, or 75A.

Since the check valve device 5 is firmly fixed to the rehabilitation pipe 3 by the bolts 18, the check valve device 5 can be prevented from shifting position even when injecting a fluid with a high specific gravity such as mortar, and the injection operation can be performed stably. Incidentally, if the check valve device 5 is attached only by fitting or gluing into the mounting hole 3h, the check valve device 5 is likely to shift position when pressure from a fluid with a high specific gravity such as mortar is applied.
Furthermore, since the body 10 and the valve seat member 20 are firmly joined by screw connection, it is possible to prevent the valve seat member 20 from shifting position relative to the body 10 or falling off, thereby making it possible to carry out the injection operation more stably.

When the backfilling material 4 has been filled into the gap 2 between the pipes, the injection operation is stopped and the injection nozzle 6 is removed from the check valve device 5.
When the injection pressure is released by stopping the injection operation, the valve body 30 is pulled back in the seating direction by the elastic biasing force of the elastic member 50, and the seating surface 35 is seated on the valve seat surface 25. This closes the check valve device 5. This prevents the backfill material 4 being cured in the pipe gap 2 from flowing back into the rehabilitating pipe 3.
By forming the locking plate 42 from a hard material, the elastic force of the elastic member 50 can be received reliably.

Because the curvature of the valve seat surface 25 and the curvature of the seating surface 35 are different from each other, when the valve is closed, the valve seat surface 25 and the seating surface 35 are in almost line contact over the entire circumference. Therefore, even if the backfill material 4 contains solid particles of minute particle size, the solid particles are less likely to be pinched between the valve seat surface 25 and the seating surface 35 compared to the case of surface contact. Furthermore, because the valve seat surface 25 is a partially concave spherical surface with a relatively large radius of curvature, and the seating surface 35 is a circular ring with a small radius of curvature and a convex curved surface, the seating surface 35 can be in close contact with the valve seat surface 25 over the entire circumference even if the valve body 30 is slightly tilted or deformed. Therefore, the check valve device 5 can be reliably closed, and the function as a check valve can be stably maintained.

As shown in FIG. 7, after the injection nozzle 6 is removed, the opening 11b is closed by the cap 16. The surface of the cap 16 is smooth so as not to disturb the flow inside the rehabilitation pipe 3. The back surface of the cap 16 is provided with a male thread 16b that screws into the female thread 15.

In this way, the buried pipe 1 is rehabilitated. After the rehabilitation work is completed and even after the rehabilitated pipe 3 is put into service, the check valve device 5 remains in place on the pipe wall 3w. In other words, there is no need to remove the check valve device 5. This eliminates the need to seal the mounting hole 3h when the injection saddle is removed, and to seal the bolt hole after the bolt 18 is removed.

2, even if the inner peripheral surface 3a of the rehabilitating pipe 3 is a cylindrical concave surface while the back surface 12d of the flange 12 is a flat surface, the elastic packing 17 is elastically deformed to reliably seal the gap between the rehabilitating pipe 3 and the flange 12. Therefore, it is possible to reliably prevent the backfilling material 4 in the inter-pipe gap 2 and underground groundwater from leaking into the inside of the rehabilitating pipe 3 from between the inner peripheral surface of the rehabilitating pipe 3 and the flange 12, and to prevent sewage in the rehabilitating pipe 3 from leaking out of the rehabilitating pipe 3 through between the inner peripheral surface of the rehabilitating pipe 3 and the flange 12. Therefore, by preventing leakage of the backfilling material 4 from the inter-pipe gap 2, it is possible to prevent a cavity from being formed in the inter-pipe gap 2.
By making the locking plate 42 out of rubber or resin, corrosion of the locking plate 42 can be suppressed, and malfunction due to corrosion can be prevented, so that the function as a check valve can be stably maintained for a long period of time.

As shown in FIG. 8, after the rehabilitation work, instead of closing the opening 11b with the cap 16, the valve body 30 may be repositioned to the second surface 21b. The valve seat member 20, the valve body 30, and the connecting shaft member 41 may be inverted as a whole, or the valve seat member 20 may be left in the same orientation and only the valve body 30 and the connecting shaft member 41 may be inverted. As a result, the check valve device 5 allows the flow of fluid from the outside to the inside of the rehabilitation pipe 3, while preventing the flow of fluid from the inside to the outside of the rehabilitation pipe 3. Therefore, for example, when groundwater pressure rises and the water pressure is applied to the check valve device 5 from the outside of the rehabilitation pipe 3, the check valve device 5 is opened to allow groundwater to escape into the rehabilitation pipe 3, thereby alleviating the water pressure applied to the rehabilitation pipe 3. In addition, the check valve device 5 is normally closed to prevent fluids such as sewage flowing through the rehabilitation pipe 3 from leaking out of the rehabilitation pipe 3. This allows the check valve device 5 to be used as a weep hole.

Next, another embodiment of the present invention will be described. In the following embodiment, the same components as those in the above-described embodiment will be denoted by the same reference numerals in the drawings and the description thereof will be omitted.
Second embodiment (FIG. 9)
As shown in Fig. 9, in the check valve device 5B of the second embodiment, the tip of the connecting shaft member 41 penetrates the valve body 30 and protrudes, and a nut 43 is screwed thereon. A locking plate 44 is interposed between the nut 43 and the valve body 30 as a washer. The locking plate 44, like the locking plate 42, is made of rubber or resin that is harder than the elastic member 50. This makes it possible to suppress corrosion of the locking plate 44 and prevent malfunction of the check valve device 5B due to corrosion. In addition, the elastic force of the elastic member 50 can be reliably received.

Third embodiment (FIGS. 10 and 11)
As shown in Fig. 10, in the check valve device 5C of the third embodiment, an elastic member 50C has a spring portion 51 and an extension portion 52 integrally formed therewith. The spring portion 51 is formed in a cylindrical shape with a relatively large outer diameter. The extension portion 52 extends to the tip side (upper side in Fig. 10) of the spring portion 51. The extension portion 52 is formed coaxially with the spring portion 51 and in a cylindrical shape with a relatively small outer diameter. A step 53 is formed between the outer peripheral surface of the spring portion 51 and the outer peripheral surface of the extension portion 52. The central shaft hole 50a of the elastic member 50C is formed to a constant hole diameter that matches the outer diameter of the connecting shaft member 41 from the spring portion 51 to the extension portion 52.

The connecting shaft member 41 is inserted into the central shaft hole 50a. The spring portion 51 is disposed between the valve seat member 20 and the locking plate 42, and is provided on the outer periphery of the portion of the connecting shaft member 41 that protrudes toward the base end side from the valve seat member 20. The base end of the spring portion 51 abuts against the locking plate 42. The step 53 abuts against the shaft support portion 22.

The extension 52 is provided on the outer periphery of the portion of the connecting shaft member 41 that extends from the inside of the shaft support 22 to the valve body 30. The portion of the extension 52 on the step 53 side is disposed within the shaft support 22. The tip of the extension 52 abuts against the valve body 30.

As shown in FIG. 10, when the check valve device 5 is closed, the spring portion 51 expands to bring the valve body 30 into close contact with the valve seat member 20, and mainly the tip portion of the extension portion 52 is compressed and deformed.
11, when the check valve device 5 is open, the spring portion 51 is compressed and deformed by the fluid pressure of mortar or the like, and the extension portion 52 is elongated by an amount corresponding to an increase in the length of the portion of the connecting shaft member 41 from the pivot portion 22 to the valve body 30 compared to when the valve is closed. In other words, the natural length of the extension portion 52 is preferably set to be equal to or greater than the distance _Lb from the base end portion (the lower end portion in FIG. 11) of the pivot portion 22 to the valve body 30 when the valve is open.

In the check valve device 5C, the elastic member 50C can be made to cover the outer periphery of the entire area of the portion of the connecting shaft member 41 from the locking plate 42 to the valve body 30, whether the valve is closed or open. This allows the elastic member 50C to also function as a coating material to prevent corrosion of the connecting shaft member 41. By preventing corrosion of the connecting shaft member 41, malfunctions of the check valve device 5 can be prevented, and the function as a check valve can be stably maintained for a long period of time.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention.
For example, the valve seat surface 25 may be a flat surface (with an infinite radius of curvature) and the seat surface 35 may be a convex curved surface.
The valve seat member 20 does not necessarily have to be reversible with respect to the body 10 .
The valve body 30 does not necessarily have to be reversible with respect to the valve seat member 20 .

The present invention can be applied, for example, to a method for rehabilitating aging sewer pipes.

1 Buried pipe 2 Pipe gap 3 Rehabilitation pipe 3w Pipe wall 3h Mounting hole 4 Backfilling material 5 Check valve device 5B, 5C Check valve device 10 Body 11a Opening 11b at tip end (end of body facing outside of rehabilitated pipe) Opening 12 at base end (end of body facing inside of rehabilitated pipe) Flange 17 Elastic packing 19 Valve unit 20 Valve seat member 21 Valve seat portion 21a First surface 21b Second surface 22 Shaft support portion 23 Connecting arm portion 24 Valve passage 25 Valve seat surface 30 Valve body 35 Seat surface 40 Connecting means 41 Connecting shaft member 42, 44 Locking plate 50, 50C Elastic member

Claims (10)

A check valve device provided in a rehabilitation pipe lined on the inner periphery of an underground buried pipe,
a cylindrical body provided in an attachment hole penetrating a pipe wall of the rehabilitation pipe;
a valve seat member having an annular valve seat surface disposed within the body;
a valve body having an annular seating surface that is seated and released on the valve seat surface and engaged with the valve seat member via a connecting means;
an elastic member that biases the valve body in a seating direction,
a curvature along an inward-outward direction connecting an outer periphery and an inner periphery of the valve seat surface is different from a curvature along an inward-outward direction connecting an outer periphery and an inner periphery of the seating surface,
A check valve device characterized in that a notched recess is formed on the edge of an opening at an end of the body facing outward from the rehabilitation pipe. A check valve device provided in a rehabilitation pipe lined on the inner periphery of an underground buried pipe,
a cylindrical body provided in an attachment hole penetrating a pipe wall of the rehabilitation pipe;
a valve seat member having an annular valve seat surface disposed within the body;
a valve body having an annular seating surface that is seated and released on the valve seat surface and engaged with the valve seat member via a connecting means;
an elastic member that biases the valve body in a seating direction,
a curvature along an inward-outward direction connecting an outer periphery and an inner periphery of the valve seat surface is different from a curvature along an inward-outward direction connecting an outer periphery and an inner periphery of the seating surface,
a first surface of the valve seat member facing an outside of the rehabilitating pipe and a second surface of the valve seat member facing an inside of the rehabilitating pipe each constitute the valve seat surface,
A check valve device, characterized in that the valve body is selectively displaceable in either a first position facing the first surface or a second position facing the second surface. 3. The check valve device according to claim 1, wherein the valve seat surface is a concave curved surface that is concave in a thickness direction of the valve seat member as it approaches the inner periphery, and the seating surface is a convex curved surface having a smaller radius of curvature than the valve seat surface along the inward / outward direction. A check valve device provided in a rehabilitation pipe lined on the inner periphery of an underground buried pipe,
a cylindrical body provided in an attachment hole penetrating a pipe wall of the rehabilitation pipe;
a valve seat member having an annular valve seat surface disposed within the body;
a valve body having an annular seating surface that is seated and released on the valve seat surface and engaged with the valve seat member via a connecting means;
an elastic member that biases the valve body in a seating direction,
a curvature along an inward-outward direction connecting an outer periphery and an inner periphery of the valve seat surface is different from a curvature along an inward-outward direction connecting an outer periphery and an inner periphery of the seating surface,
a check valve device characterized in that the valve seat surface is a concave curved surface that is concave in a thickness direction of the valve seat member toward the inner periphery, the seating surface is a convex curved surface with a smaller radius of curvature than the valve seat surface along the inward/outward direction, and a ratio of the radius of curvature (R ₂₅ ) of the valve seat surface to the radius of curvature (R ₃₅ ) of the seating surface is R ₂₅ :R ₃₅ = 10:1 to 50:1. 5. The check valve device according to claim 1, wherein the valve seat surface is a partially concave spherical surface, and the seating surface is annular and has a convex curved surface shape with a smaller radius of curvature than the valve seat surface along the inward and outward direction. the connecting means includes a connecting shaft member that is joined to the valve body and that penetrates the valve seat member to protrude toward an opposite side to the valve body, and a locking plate that is provided on a protruding end of the connecting shaft member,
the elastic member is formed in an annular shape and fitted around an outer periphery of at least a portion of the connecting shaft member between the locking plate and the valve seat member to apply an elastic force so as to separate the locking plate and the valve seat member,
6. The check valve device according to claim 1, wherein the engaging plate is made of rubber or resin harder than the elastic member. 7. The check valve device according to claim 6 , wherein the elastic member covers an outer periphery of the entire area of the portion of the connecting shaft member from the locking plate to the valve body. A check valve device as described in any one of claims 1 to 7, characterized in that a flange protruding radially outward from the body is formed on the end of the body facing the inside of the rehabilitated pipe, and a screw hole is formed in the flange to pass a bolt for fixing to the rehabilitated pipe. 9. The check valve device according to claim 8 , further comprising an elastic packing interposed between the flange and the inner peripheral surface of the rehabilitation pipe. The check valve device according to any one of claims 1 to 9, characterized in that a female thread is formed on an inner circumferential surface of the body, and a male thread is formed on an outer circumferential surface of the valve seat member to be screwed into the female thread.

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