JPH0874495A - Pipe end water leak preventing structure - Google Patents

Abstract

PURPOSE: To prevent the leak of a fluid from a pipe end. CONSTITUTION: A plug with a collar 11 is screwed with a pipe end, and an elastic ring 14 is interposed between the pipe end and the collar 11. In such pipe end water leak preventing structure, the plug 1 is provided with a peripheral groove 13 opened at the edge of the collar 11, and the elastic ring 14 is fitted in such a way that the cross section center-of-gravity of the ring 14 is positioned inside the thread ridge outer diameter of the plug 1 in the non-acting state of compressive load. With the plug 1 screwed with the pipe end, the elastic ring 14 is pressed to the pipe end face and the internal thread so as to be compression-deformed. A space between the peripheral groove 14 and a thread groove 21 at the inner surface of the pipe end is thereby filled with the wall of the elastic ring 14, and part of the wall of the elastic ring 14 bulges into a gap between the pipe end face and the plug 11, over the whole periphery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water leakage preventing structure for a pipe end used for piping of a fluid substance, and particularly to a mortar injection pipe arranged in a tunnel segment in a tunnel construction by a shield construction method. The present invention relates to a water leakage prevention structure for preventing leakage of groundwater, mortar, etc.

[0002]

2. Description of the Related Art Conventionally, to prevent water leakage from the mortar injection pipe, as shown in FIG. 6, a plug (1) in which an elastic ring (14) is fitted on a screw surface along a collar (11) is used. It is screwed to the pipe end of the and the elastic ring is formed between the pipe end face (20) and the collar (11).
(14) is compressed and deformed to prevent water leakage.

[0003]

In the above water leakage prevention structure, the elastic ring (14) is fitted from above the threaded surface of the plug (1), and when the plug (1) is screwed into the pipe end. , Pipe end face (2
The elastic ring (14) is elastically deformed so that its cross section becomes a flat body by being pinched between the (0) and the collar (11).

As the amount of tightening of the plug (1) increases, the flatness of the elastic ring (14) increases, and the elastic ring (14) increases.
(14) and the pipe end face (20) and the elastic ring (14) and the collar (11) have a large contact area, and the elastic ring (14) is partially covered by the pipe end face (2).
It sticks out from between 0) and tsuba (11). That is, plug
Even if (1) is fully tightened, the elastic ring (14) and pipe end face
The surface pressure between the elastic ring (14) and the collar (11) (20) does not become so high.

In the above water leakage structure, the fluid pressure in the pipe (2) is 1
Water leakage could be prevented up to about 2 atm, but if it is a high-pressure fluid higher than that, between the elastic ring (14) and the pipe end surface (20) or between the elastic ring (14) and the collar (11), From the weakly crimped part (the end of the pipe or the inner surface of the collar where the finish is poor),
High-pressure fluid leaks in a state where water is jetted from a water gun. In order to cope with high-pressure spring water during subsea tunnel construction, it is required to prevent leakage of high-pressure fluid more than before, and in order to respond to this, conventionally, the sealing tape was wrapped around the threaded part of the plug (1) before the plug (1 ) Was fastened to the pipe end, which was troublesome and resulted in a poor work performance ratio.

[0006] Therefore, the applicant does not crush the elastic ring (14) between the pipe end surface (20) and the collar (11) to prevent water leakage, but does not surround the plug (1) around the collar (11). Opening the groove (13), the peripheral groove
The elastic ring (14) is fitted to (13) and the inner surface of the pipe (2) and the peripheral groove (1
Experiments were repeated considering the prevention of water leakage by crimping the elastic ring (14) between 3).

As a result, the elastic ring (1) fitted with the circumferential groove (13) is
If the center of gravity of the cross section before compression of 4) is located outside the screw thread outer diameter of the plug (1), even if the plug (1) is tightened to the limit, leakage prevention against high pressure fluid of 12 atm or more can be prevented. It turns out that no effect is obtained.

This is because when the elastic ring (1) is shallowly fitted in the circumferential groove (13), when the plug (1) is tightened in the pipe (2).
Even if the meat of the elastic ring (1) escapes between the pipe end face (20) and the collar (11) and the plug (1) is tightened to the limit, the circumferential groove (13)
Elastic ring enclosed between the groove on the inner surface of the pipe and the thread groove (21)
The compression pressure against (14) should not be so high,
As the amount of tightening of the plug (1) is increased, the flatness of the elastic ring (14) between the pipe end face (20) and the collar (11) becomes large, and as described above, the pipe end face (20) This is because the surface pressure of the elastic ring (14) against the collar (11) and the collar (11) is not so high.

As a result of earnest efforts based on the above experimental results, the present invention has realized the prevention of water leakage of a fluid substance having a high pressure of 12 atm or more. The structure will be clarified below.

[0010]

In order to solve the above problems, the water leakage prevention structure of the present invention has a plug with a collar (11) at the pipe end.
(1) is screwed and the elastic ring (14) is inserted between the pipe end and the collar (11).
In the structure for preventing water leakage at the pipe end, the plug (1) opens the circumferential groove (13) at the time of the collar (11), and the elastic ring (14) of the ring when the compression load is not applied. The center of gravity of the cross section is the plug
It is fitted so that it is located inside the outer diameter of the thread of (1), and the elastic ring (14) is pressed against the tube end surface (20) and the tube inner surface by tightening the plug (1) to the tube end. Elastically deforms and plugs
The elastic ring (14) fills in a compressed state between the circumferential groove (13) of (1) and the thread groove (21) of the inner surface of the pipe, and a part of the elastic ring (14) has a full circumference. The gap between the pipe end face (20) and the plug (1)
It is found in (5).

[0011]

[Operation and effect] The elastic ring (14) fitted in the circumferential groove (13) of the plug (1) has a sectional center of gravity located inside the outer diameter of the thread of the plug (1). When tightening 1) into the pipe (2), the inner edge of the pipe end face (20) presses the elastic ring (14) inward, that is, presses the elastic ring (14) against the circumferential groove (13). While pressing, it approaches the flange (11) of the groove plug (1). The flesh of the elastic ring (14) is elastically deformed by receiving a large inward compressive pressure, filling the space between the circumferential groove (13) and the thread groove (21) of the pipe (2) in a compressed state, and further elastically. Part of the ring (14)
Over the entire circumference, it protrudes into the gap between the pipe end and the collar (14).

In this way, when the flesh of the elastic ring (14) is filled in the compressed state between the circumferential groove (13) and the thread groove (21) of the pipe under the condition that a large compression pressure is applied, the elastic ring is The surface pressure between the thread groove (21) on the inner surface of the pipe (2) and the elastic ring (14) and the peripheral groove (13) of the plug (1) increases, and a high water leakage effect can be obtained by this alone. In addition, in the present invention, a part of the elastic ring (14) protrudes between the pipe end and the collar (11) over the entire circumference,
At the time of protruding (14a) of this protruding portion, the contact pressure is particularly increased by being pressed by the inner edge corner portion of the pipe end, and a strong water leakage effect is exhibited.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In the tunnel construction by the shield method,
As shown in FIG. 4, a pressure resistant cylinder (33) is formed by combining a plurality of segments (4) in a tubular shape into a lateral hole (31) excavated in the ground (32) by a tunnel excavator, The void (34) generated between the segment (31) and the segment (4) is filled with mortar M to stabilize the ground (32).

The filling procedure of the mortar M is as follows:
The pipe (2) for mortar injection is fitted into the hole (42) opened in the tube, and the check valve (22) is screwed into the pipe (2) for injection and left. Connect the mortar injection hose (24) to the injection tube (2),
The mortar M is made to flow in from the hose (24) and the mortar M is filled in the surrounding void (34) through the check valve (22).

After injecting the mortar, insert the hose (24) into an injection tube.
Remove from (2) and screw the plug (1) into the injection pipe (2) to prevent the mortar M and groundwater from flowing out.

The segment (4) is a plate surface (41) which is made of steel or concrete having a thickness of 200 to 700 mm and is curved in an arc shape. A fixing hole (not shown) is opened. A hole (42) is opened in the plate surface (41),
The mortar injection pipe (2) is fitted into the hole (42). The mortar injection pipe (2) is welded to the segment (4) when the segment (4) is made of steel, and the mortar injection pipe (2) when the segment (4) is made of concrete. After deploying, the concrete is poured and cured.

As shown in FIGS. 1 and 3, the mortar injection pipe (2) is a cylinder and is fitted in a hole (42) formed in the plate surface (41) of the segment (4). For the mortar injection tube (2),
The thread groove (21) is cut, and the thread groove (21) has a segment
A known check valve (2) having a valve plate (23) that opens only to the outside of (4)
Screw 2). After the mortar M has been injected, the plug (1) is screwed onto the inner end of the mortar injection tube (2).

As shown in FIGS. 1 to 3, the plug (1) is formed by injection molding of a casting or a hard synthetic resin, and has an external thread.
The shank (10) has a flange (11) at one end of the shank (10), and the shank (10) makes a round groove around the shank (10) at the time of the flange (11). 13) has been formed.

An elastic ring (14) formed of an elastic member such as synthetic rubber is fitted in the circumferential groove (13) of the plug (1). The elastic ring (14) has a circular cross section, the circumferential groove (13) is a round bottom groove corresponding to the cross section of the ring (14), and the circumferential groove (13) on the surface passing through the axis of the plug (1). ) The center of curvature P of the bottom surface of
It is located inside the outer diameter of the thread of the plug (1). Therefore, the center of gravity of the cross section of the elastic ring (14) matches the radius of curvature P of the circumferential groove (13) and is located inside the outer diameter of the thread.

A tool engaging hole (17) for engaging a rotary tool is formed on the flange-side end surface of the plug (1), and a hole (19) for reducing weight is formed at the center of the other end. The collar (11) is formed with a non-slip protrusion (18).

After injecting the mortar M from the mortar injecting pipe (2), the plug (1) is manually turned and temporarily tightened, and a rotary tool such as a wrench is engaged with the tool engaging hole (17) and rotated. By tightening,

An elastic ring fitted in the circumferential groove (13)
Since the center of gravity of the cross section of (14) is located inside the outer diameter of the screw thread, when the plug (1) is tightened into the pipe (2), the pipe end face (2
The inner edge of (0) approaches the flange (11) of the plug (1) while pressing the elastic ring (14) inward, that is, compressing the elastic ring (14) against the circumferential groove (13).

The flesh of the elastic ring (14) is elastically deformed by receiving a large inward compressive pressure, and the peripheral groove (13) and the thread groove (2) of the pipe (2).
1) Compressed between screws and elastic ring (14)
A part of the bulge protrudes into the gap between the pipe end and the collar (14) over the entire circumference.

As described above, when the flesh of the elastic ring (14) is filled in a compressed state between the circumferential groove (13) and the thread groove (21) of the pipe under the condition that a large compression pressure is applied, the elastic ring is The surface pressure between the thread groove (21) on the inner surface of the pipe (2) and the elastic ring (14) and the peripheral groove (13) of the plug (1) increases, and a high water leakage effect can be obtained by this alone. In addition, in the present invention, a part of the elastic ring (14) protrudes between the pipe end and the collar (11) over the entire circumference,
At the time of protruding (14a) of this protruding portion, the contact pressure is particularly increased by being pressed by the inner edge corner portion of the pipe end, and a strong water leakage effect is exhibited. In the experiment, it was confirmed that even if a high pressure fluid of 35 atm was poured into the pipe, water leakage could be prevented from the pipe end.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or limiting the scope. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

For example, the cross-sectional outer shape of the elastic ring (14) is not limited to a circular shape, and the center of gravity of the cross-section of the elastic ring (14) before compression deformation is located inside the outer diameter of the thread of the plug (1). If it has, it may be a quadrangle with one side as shown in FIG. Further, the water leakage prevention structure of the present invention can be implemented not only for liquids other than water but also for fluid leakage such as mortar, and it is needless to say that such a leakage prevention structure is included.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a water leakage prevention structure at a pipe end.

FIG. 2 is a sectional view of a plug.

FIG. 3 is a cross-sectional view of a segment mortar injection tube.

FIG. 4 is a sectional view of a tunnel.

FIG. 5 is a cross-sectional view of another embodiment.

FIG. 6 is a sectional view of a conventional example.

[Explanation of symbols]

 (1) Plug (11) Tsuba (13) Circumferential groove (14) Elastic ring (2) Pipe (20) Pipe end face (4) Segment

Claims (1)

[Claims] 1. A plug (1) with a collar (11) is screwed onto a pipe end,
In the water leakage prevention structure of the pipe end, in which the elastic ring (14) is interposed between the pipe end and the flange (11), the plug (1) has a circumferential groove at the time of the flange (11).
(13) is opened, and the elastic ring (14) is fitted so that the center of gravity of the cross section of the ring is located inside the outer diameter of the thread of the plug (1) in the state where no compressive load is applied. Plug to the end
By the tightening of (1), the elastic ring (14) is pressed against the pipe end surface (20) and the inner surface of the pipe and elastically deforms, and the circumferential groove (13) of the plug (1).
And the thread groove (21) on the inner surface of the pipe fills the flesh of the elastic ring (14) in a compressed state, and part of the flesh of the elastic ring (14) forms a pipe end face (20) along the entire circumference. A structure for preventing water leakage at the pipe end protruding into the gap (5) with the plug (1).