JPH0285595A - Liquid inflow preventing plug for branch pipe - Google Patents

Abstract

PURPOSE:To prevent a liquid inflow preventing plug from being dropped from a branch pipe by providing a coupling member with a check valve liquid-tightly pressed into the branch pipe and a hooking member preventing the infiltration of the coupling member into the branch pipe in the liquid inflow preventing plug fitted into the branch pipe. CONSTITUTION:A liquid inflow preventing plug 1 is constituted of a coupling member 30 and the hooking plate 10 of a hooking member. The coupling member 30 is molded into a tube shape with an expandable material as rubber and liquid-tightly pressed into a branch pipe 3, and a check valve 20 feeding a liquid only to a main pipe 2 from the branch pipe is provided. The hooking plate 10 is fitted to the coupling member 30 and prevents its infiltration into the branch pipe 3. As a result, the liquid inflow preventing plug is fitted to the inner end of the branch pipe for use when lining is applied to a main pipe with a synthetic resin pipe, and sewage or the like flows into the main pipe but does not reversely flow into the branch pipe. A back-filling material filled between the synthetic resin pipe and the branch pipe is prevented from flowing into the branch pipe.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a method for lining a buried main pipe such as a sewer pipe with synthetic resin, by connecting a branch pipe branched from the main pipe to the main pipe. The present invention relates to a liquid inflow prevention plug that is attached to an end of the branch pipe and prevents liquid from flowing into the branch pipe.

(Conventional technology) For buried pipes used for water supply and sewerage.

Metal pipes and Huyum pipes have been used since ancient times.

Such buried pipes become obsolete through long-term use, and there is a risk that they may become damaged due to corrosion, cracks, etc., and leak water. For this reason, recently, a synthetic resin pipe is inserted into the aging buried pipe to line it.

In such a rainy leg construction method, for example, JP-A-61
Publication No. 38031 states that when lining a buried main pipe with a large number of branch pipes branched from one main pipe with synthetic i-fat pipes,
A method of shutting off each branch pipe to prevent sewage from flowing into the main pipe from each branch pipe is disclosed. In this publication, a rubber stopper is used as a water stopper, and by press-fitting the rubber stopper into the branch pipe, the water in the branch pipe is stopped.

(Problems to be Solved by the Invention) Even when lining an existing main pipe with synthetic resin pipes, normally, sewage such as domestic wastewater and spring water flow through each branch pipe connected to the main pipe. It will be done. For this reason, if a stop valve is attached to the end of the first branch pipe as in the above-mentioned publication, the sewage and the like flowing through the two branch pipes will be stopped and will not flow into the main pipe. However, as the amount of sewage water to be shut off increases, the pressure from the two-branch pipe toward the main pipe increases at the stop valve. Normally, the existing main pipe is buried underground at a depth of about 3 m from the ground, so the stopcock installed in the 2-branch pipe has a maximum weight of 0.3 kg1.
/cd of water pressure is applied. If a rubber stopper is simply press-fitted into the branch pipe as a water stop valve, as in the above-mentioned publication, there is a risk that the rubber stopper may come out of the branch pipe due to the pressure of the sewage or the like to which the water is stopped.

When lining an existing main pipe with a synthetic resin pipe or the like, a backfilling agent is filled between the main pipe and the synthetic resin pipe lining the main pipe. What is the backfilling agent?

Normally, a stopcock attached to the end of a bifurcated pipe is filled with a pressure of about 0.5 kg-f/d.

Opposite to the pressure of the sewage or the like to be shut off, a force pushing the backfilling agent into the branch pipe acts, and there is a risk that the water stop valve may be forced into the branch pipe. When the synthetic resin pipe is fixed in the main pipe with a backfilling agent, a through hole is opened through which the synthetic resin pipe, the backfilling agent, and the stopcock are inserted so that the synthetic resin pipe communicates with the branch pipe. 1 Sewage, etc. flowing through the branch pipe must be allowed to flow into the main pipe. To do this, it is necessary to drill a hole from within the first synthetic resin pipe, but once the stopcock is pushed into the branch pipe as described above.

The backfilling agent flows into the branch pipe, increasing the stroke for drilling. The inner diameter of synthetic resin pipes is relatively small, and when drilling from inside the synthetic resin pipe, it is very difficult to increase the stroke for drilling, so the stopcock is pushed into the branch pipe and back-filled. If the agent flows in, there is a risk that it will not be possible to open a through hole in the stop valve.

In order for the stopcock to withstand the pressure applied from both the sewage flowing through the first branch pipe and the backfilling agent filled in the main pipe, the outer circumferential surface of the stopcock and the inner circumferential surface of the branch pipe are It is possible to increase the contact pressure. For this purpose, for example,
If the diameter of the stopcock is increased, it becomes difficult to press fit the stopcock into the branch pipe. Furthermore, if the stopcock is made longer in the axial direction of the branch pipe, there is a risk that it will not be possible to form a through hole in the stopcock.

The present invention is intended to solve the above-mentioned conventional problems, and its purpose is to prevent the backfilling agent filled in one branch pipe from becoming separated from the branch pipe due to sewage flowing through the branch pipe, and to prevent the backfilling agent filled into one branch pipe from branching out. An object of the present invention is to provide a plug for preventing liquid from flowing into a branch pipe, which can reliably prevent liquid from flowing into the pipe.

(Means for Solving the Problems) A liquid inflow prevention stopper for a branch pipe of the present invention is attached to an end of a branch pipe branched from a main pipe that communicates with the main pipe, and prevents liquid from flowing into the branch pipe. A fitting member that is fitted into an end of the branch pipe to be fluid-tightly crimped to the inner circumferential surface of the end, and that allows liquid to flow through the inside of the stopper. , when the fitting member is fitted to the end of the branch pipe.

A check valve provided in the fitting member to allow liquid to flow through the fitting member only from the branch pipe to the main pipe, and when the fitting member is fitted to the end of the branch pipe. and a locking member attached to the fitting member to lock the inner peripheral surface of the two main pipes and prevent the fitting member from entering the branch pipe, thereby achieving the above object. achieved.

(Example) The present invention will be described below with reference to Examples.

The stopper for preventing liquid from flowing into a branch pipe according to the present invention can be used, for example, when lining a main pipe 2 of an old sewer pipe with a synthetic resin pipe, as shown in FIG.

It is used by being attached to the end of a branch pipe 3 that branches off from the main pipe 2 and communicates with the main pipe 2.

The liquid inflow prevention stopper 1 has a locking plate 10 which is a rectangular flat plate curved along the inner circumferential surface of the main pipe 2 . Each side of the locking plate 10 is longer than the inner diameter of the one branch pipe 3. A through hole 11 is provided in the center of the locking plate lO, and a cylindrical valve seat 21 of the check valve 2o is fitted into the through hole 11. The valve seat 21 in the check valve 20
is connected via a cylindrical base end 21a that is fitted into the through hole 11 of the locking plate 10 and a tapered part 21b that is tapered in diameter, and has a smaller diameter than the base end 21a. Body part 2
1c. Then, the tapered portion 21b of the valve seat 21
A valve body 22 is disposed therein. The valve body 22 includes a disc-shaped valve body 22a disposed perpendicularly to the axis of the tapered portion 21b, and a valve body 21c of the valve seat 21 along the diameter of the valve body 22a. The support portion 22b protrudes from the support portion 22b. The disc-shaped valve main body 22a is arranged on each side of the support part 22b so that each semicircular half divided by the support part 22b can rotate into the base end part 21a of the valve seat 21. The proximal end portion 21a side portion of the valve body 22a adjacent to the valve body 22a is cut out along the support portion 22b to become thin. The outer peripheral edge of the side surface of the valve body 22a facing the main body portion 21c of the valve seat 21 has a size that allows it to be pressed against the inner peripheral surface of the tapered portion 21b of the valve seat 21, and due to the pressure contact, both are in a liquid-tight state. becomes. Therefore, the check valve 20.

By the liquid flowing from the main body portion 21c side of the valve seat 21.

The valve body 22a of the valve body 22 is rotated to be in the open state.

The liquid may flow through the valve seat 21, but if the liquid flows in the opposite direction, the outer peripheral edge of the valve body 22a of the valve body 22 is pressed against the inner peripheral surface of the tapered portion 21b of the valve seat 21. The valve is in a liquid-tight closed state, and the liquid cannot flow through the valve seat 21.

An annular fitting member 30 is fitted onto the cylindrical valve seat 21 of the check valve 20 . The fitting member 30 is formed into a tube shape from a stretchable material such as rubber. The inner circumferential surface of the fitting member 30 is liquid-tightly bonded to the outer circumferential surface of the valve seat 21. The fitting member 30 has an air injection valve 31 for filling the inside thereof with gas. When the fitting member 30 is filled with gas, the fitting member 30 is inserted into the through hole 11 excluding the outer peripheral edge of the locking plate 10.
is crimped around the .

If the fitting member 30 is press-fitted into the branch pipe 3 in this state, its outer peripheral surface will be fluid-tightly pressed against the inner peripheral surface of the branch pipe 3.

The fitting member 30 may be expanded by injecting air from the air injection valve 31 while the locking plate IO is in contact with the peripheral edge of the branch pipe 3.

The liquid inflow prevention plug 1 for a branch pipe of the present invention having such a configuration is used in a lining method for rehabilitating an aging main sewer pipe 2 by lining it with a synthetic resin spiral pipe.

In this lining construction method, prior to the step of inserting a spiral pipe into one main pipe 2.

The liquid inflow prevention plug l of the branch pipe of the present invention is installed in the end of the branch pipe 3.

The liquid inflow prevention stopper 1 fills the fitting member 30 with gas, expands the fitting member 30, moves from the inside of the main pipe 2 into the branch pipe 3, and positions the locking plate 10 inside the main pipe 2. In this state, the fitting member 30 is press-fitted. Due to this.

The outer circumferential surface of the fitting member 30 is pressed against the inner circumferential surface of the end of the branch pipe 3, so that the outer circumferential surface of the fitting member 30 and the inner circumferential surface of the branch pipe 3 are in a liquid-tight state. At this time, the outer peripheral edge of the locking plate IO does not enter into the branch pipe 3, but is located inside the main pipe 2, and is locked to the inner peripheral surface of the main pipe 2. In this way, the liquid inflow prevention plug l
is installed in the branch pipe 3.

When attaching the liquid inflow prevention stopper 1 to the branch pipe 3, for example, if the inner diameter of the main pipe 2 is so small that one worker cannot fit therein, an appropriate stopper installation device is used. The stopper mounting device is constituted by two parts: an elevating part on which, for example, the liquid inflow prevention stopper 1 is placed and moved up and down, and a conveying part that transports the elevating part.

Sewage, etc., flows through the branch pipe 3 to which the liquid inflow prevention plug 1 is attached, but the sewage, etc. flowing through the branch pipe 3 is inside the fitting member 30 of the liquid inflow prevention plug 1. After flowing into the valve seat 21 of the fitted check valve 20 and staying in a predetermined amount,
The valve body 22 is rotated to allow the flow into the main pipe 2.

In this way, through the check valve 20 of the liquid inflow prevention plug 1,
A synthetic resin spiral pipe is inserted into the main pipe 2 while sewage or the like flows into the main pipe 2. The spiral pipe 1 is manufactured, for example, by a pipe making machine installed in a manhole to which one end of the main pipe 2 is connected.

Nine synthetic resin strips are sequentially introduced into the pipe making machine, and the pipe making machine winds the strips in a spiral to connect adjacent side edges of the wound strips. A helical tube is manufactured in a static state. Then, the spiral tube manufactured by the pipe making machine is directly inserted into the two main pipes 2.

In this way, the spiral tubes are sequentially inserted into the main tube 2. At this time, sewage, etc. is flowing into the two main pipes 2 through the check valve 20 of the liquid inflow prevention plug 1 attached to the two branch pipes 3, but when the spiral pipe is inserted into the main pipe 2, There is no problem. When the spiral tube is inserted into the main pipe 2.

Sewage and the like that have flowed into the main pipe 2 flow between the main pipe 2 and the spiral pipe.

Next, between the main pipe 2 and the spiral pipe, a backfilling agent is applied, for example.
It is filled at a pressure of about 0.5 kg-r/cd.

The backfilling agent is filled from one end of the two main pipes 2 into the gap between the main pipe 2 and the spiral pipe. As a result, the sewage and the like in the two main pipes 2 are sequentially pushed out from the other end of the main pipe 2 by the backfilling agent.

What is the backfilling agent filled between the main pipe 2 and the spiral pipe?

It attempts to flow into the branch pipe 3 connected to the main pipe 2.

However, since the liquid inflow prevention plug 1 of the present invention is attached to the end of the branch pipe 3, the backfilling agent does not flow into the valve seat 21 of the check valve 20 in the liquid inflow prevention plug 1. , the valve body 22 in the cough valve seat 21 is attached to the tapered portion 21b of the valve seat 21.
Crimp on the inner circumferential surface. As a result, the valve body 22 is closed, and the backfilling agent does not pass through the valve seat 21, so that the backfilling agent does not flow into the nine-branch pipe 3.

The liquid inflow prevention plug 1 is pressed into the branch pipe 3 by the backfilling agent, but at this time, the locking plate lO of the liquid inflow prevention plug 1 is locked to the inner peripheral surface of the two main pipes 2. Therefore, there is no risk that the liquid inflow prevention plug 1 will be pushed into the branch pipe 3.

Therefore, there is no possibility that the backfilling agent will flow into the end of the bifurcated pipe 3.

- When a backfilling agent is filled between the main pipe 2 and the spiral tube as in step 2, after the backfilling agent is hardened.

The spiral tube is connected so that the branch tube 3 and the spiral tube communicate with each other.

A through hole is opened through which the backfilling agent and the liquid inflow prevention stopper l are inserted. Since the through hole 9 is usually formed by drilling from inside the spiral tube, a marker is attached to the liquid inflow prevention stopper 1. and.

By detecting the marker from inside the spiral tube with a sensor, the position to be drilled is detected. As the marker,
A resonator or the like that oscillates a sound wave or the like by resonating with the sound wave or the like emitted from the sensor is used.

When the position to be drilled is detected from inside the spiral pipe.

A hole is drilled at that position to form a through hole that communicates the spiral pipe and the branch pipe 3. At this time, since no backfilling agent has flowed into the two-branch pipe 3, the drilling stroke depends on the thickness of the backfilling agent between the outer peripheral surface of the spiral tube and the locking plate IO, and the thickness of the locking plate IO. This is the thickness and the axial length of the fitting member 30. However, since the fitting member 30 is made of rubber or the like and is formed into a channel shape, if a hole or the like is made in a part of the fitting member 30, it will burst.

Therefore, the actual drilling stroke is between the helical tube and the locking plate 1.
The thickness of the backfilling agent between 0 and 0 and the thickness of the locking plate 10 are approximately equal. Therefore, a through hole that communicates the spiral pipe and the branch pipe 3 is easily formed.

3 and 4 show other embodiments of the liquid inflow prevention plug 1' for a branch pipe according to the present invention. It has a circular shape. Further, the locking plate 10° has a long plate shape, and each longitudinal end thereof is locked to the inner circumferential surface of the main pipe 2. Furthermore, the check valve 20° of this embodiment is disposed within a cylindrical body 40 fitted within the fitting member 30', and its lower end is fitted into the through hole 12 of the locking plate 10°. has been done. A thread groove is formed on the inner peripheral surface of the cylinder 40.

The check valve 20' has a cylindrical valve seat 2'3. A threaded groove is formed on the outer circumferential surface of the valve seat 23 and is threaded into a threaded groove formed on the outer circumferential surface of the cylindrical body 40. A flat support portion 23a extending in the axial direction is provided at a diametrical position of the valve seat 23, and below the support portion 23a.

The valve body 24 is attached with a butterfly bolt 23b that passes through the axial center of the support portion 23a. The valve body 24 has a disk shape, and the outer peripheral edge of its upper surface can come into contact with the tapered lower end surface of the valve seat 23. The lower part of the valve body 24 along the support portion 23a is thin, and each half of the valve body 24 can rotate downward around the thin part. The operation of the liquid inflow prevention plug 1° is the same as that of the liquid inflow prevention plug 1 of the previous embodiment.

FIG. 5 shows still another embodiment of the liquid inflow prevention stopper of the present invention. The liquid inflow prevention plug l'' of this example is as follows:
It has a locking plate 10'' which is a rectangular flat plate curved along the circumferential surface of the main pipe 2. A through hole 13 is formed in the center of the locking plate 10''. A short cylindrical fitting member 30'' having an inner diameter larger than the inner diameter of the through hole 13 is attached to the outer peripheral surface of the through hole 10'' concentrically with the through hole 13.

The fitting member 30'' is made of an elastic body such as rubber and has an outer diameter slightly larger than the inner diameter of the nine-branch pipe 3. The outer peripheral surface of the fitting member 30'' is provided with pleats. When the fitting member 30'' is press-fitted into the branch pipe 3, the outer circumferential surface of the fitting member 30'' and the inner circumferential surface of the branch pipe 3 are fluid-tightly pressed together.

A check valve 20'' is provided on the inner circumferential surface of the locking plate lO'' for regulating one side of the flow of liquid flowing through the through hole 13.

The check valve 20'' is made of an elastic material such as rubber and has a disc shape with an outer diameter slightly larger than the inner diameter of the through hole 13. A part of the outer peripheral edge is attached to the outer edge of the through hole 13 on the peripheral surface.

The check valve 20'' is pushed downward by sewage, etc. flowing through the two-branch pipe 3 and becomes open, allowing the sewage, etc. to flow into the main pipe 2.However, the two-branch pipe 2 and the spiral pipe The backfilling agent filled between the check valve 20'' and the outer edge of the through hole of the locking plate 10'' is caused by the repulsive action of the elastic body curved along the inner surface of the locking plate 10''. .

Since it is crimped and closed, it does not flow into the nine-branch pipe 3.

(Effects of the Invention) The liquid inflow prevention stopper of the branch pipe of the present invention has the following features: 9. In this way, sewage flowing through the branch pipe flows into the main pipe, and there is no risk of liquid flowing into the branch pipe. As a result, when rehabilitating a main pipe by lining it with a synthetic resin pipe, the backfilling agent filled between the synthetic resin pipe and the main pipe is reliably prevented from flowing into the branch pipe. Also, the liquid inflow prevention plug.

Since the locking member prevents intrusion into the branch pipe, the through hole formed to communicate the inside of the synthetic resin pipe and the branch pipe after being filled with the backfilling agent is long (there is no risk of it becoming 1 The liquid inflow prevention stopper of the present invention is suitably used in a method of rehabilitating nine main pipes by lining them with synthetic resin pipes.

Fig. 1 is a sectional view showing an example of the liquid inflow prevention plug of the branch pipe of the present invention, Fig. 2 is a plan view thereof, and Fig. 3 is a cross-sectional view showing an example of the liquid inflow prevention plug of the present invention. A sectional view showing an example.

FIG. 4 is a plan view thereof, and FIG. 5 is a sectional view showing another example of the liquid inflow prevention stopper of the present invention.

1.1', 1''...Liquid inflow prevention plug, 2...Main pipe.

3... Branch pipe, 10... Locking plate, 11.12.
13...Through hole, 20°20', 20"...Check valve,
21.23... Valve seat, 22.24... Valve body.

30.30', 30--fitting member.

that's all

Claims (1)

[Scope of Claims] 1. A liquid inflow prevention plug for a branch pipe that is attached to an end of a branch pipe that branches from a main pipe and communicates with the main pipe to prevent liquid from flowing into the branch pipe. , a fitting member that is fitted into the end of the branch pipe and is fluid-tightly pressed against the inner circumferential surface of the end, and through which liquid can flow; a check valve provided on the fitting member to allow liquid to flow through the fitting member only from the branch pipe to the main pipe when the fitting member is fitted to the end of the branch pipe; a locking member attached to the fitting member to lock onto the inner circumferential surface of the main pipe and prevent the fitting member from entering the branch pipe when the fitting member is fitted into the branch pipe; Plug to prevent liquid inflow into the pipe.