JPH1161864A - Joint structure for manhole and connecting pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the damage of a connecting pipe by watertightly fixing a joint pipe having the diameter larger than the outer diameter of the connecting pipe to the outer peripheral wall of a manhole, and freely inserting the base end section of the connecting pipe into the joint tube with a seal member inserted into a gap. SOLUTION: A guide tube section 3b provided at the base end section of the small-diameter section 3a of a joint tube 3 is freely inserted into a fitting hole 2 to a position nearly matching with the inner peripheral face of a manhole 1. An O-ring 4 is inserted and sealed into a gap formed between them. A fitting plate 5 is provided on the outer peripheral face of the small-diameter section 3a, and a bolt 7 is screwed into an anchor 6 buried on the outer peripheral wall to fix the fitting plate 5 to the manhole 1. The base end section of a connecting pipe 8 is freely inserted into a large-diameter section 3c. Sealing material 10 is inserted into a circular groove 9 to keep watertightness. When a bending load is applied to the connecting pipe 8, it is warped by the gap in the large-diameter section 3c. A bending space can be formed in the joint pipe 3, and the flexibility of the connecting pipe 8 can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for connecting a connecting pipe to a side wall of a manhole, and more particularly to a connecting section having great flexibility without damaging the connecting pipe. It relates to a joint structure.

[0002]

2. Description of the Related Art A conventional joint structure of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 8-41920.

As shown in FIG. 4, a rigid socket b having an inner diameter sufficiently larger than an outer diameter of a mounting pipe (connection pipe) a is fixed around a mounting hole d in a side wall of a manhole c, as shown in FIG. A base portion of a tapered flexible cylindrical body e having an inner diameter of a tip portion substantially equal to an outer diameter of the mounting tube a is fixed to the socket b, and a mounting hole d of the manhole c, a rigid socket b, and a flexible cylindrical body e. Then, by inserting the mounting pipe a, the mounting pipe a is configured to be supported at the distal end portion of the flexible cylindrical body e.

[0004]

In the above-mentioned conventional joint structure, the base end of the mounting pipe a is inserted into the mounting hole d of the manhole c so as to be substantially aligned with the inner peripheral surface. When a large bending load acts on the mounting pipe a due to an earthquake or the like, the base pipe outer peripheral edge of the mounting pipe a comes into contact with the inner peripheral surface of the mounting hole d, or an invert (headrace) inserted into the manhole c. f.

[0005] In this case, not only is the base end of the mounting pipe a damaged, but also sufficient flexibility cannot be obtained.

In order to solve this problem, it is conceivable to increase the inner diameter of the mounting hole d to provide a large gap g between the mounting hole a and the outer peripheral surface. However, this is expected to affect the strength of the manhole c and increase the amount of impurities contained in the fluid that accumulate in the gap g, which impairs flexibility.

In the conventional joint structure described above, the mounting hole d and the gap g between the rigid socket b and the mounting pipe a may be filled with mortar or the like. Is fixed in the manhole c,
Its seismic resistance and flexibility are almost lost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a high flexibility and a manhole and a connecting pipe which can prevent the connecting pipe from being damaged by contacting the manhole or the like. The purpose of the present invention is to provide a joint structure.

[0009]

In order to achieve the above object, a joint structure according to the present invention connects a connection pipe through which a fluid in a manhole flows to an attachment hole formed in a side wall of the manhole. And a joint pipe having a required length larger than the outer diameter of the connection pipe is fixed to the outer peripheral wall of the manhole around the mounting hole while maintaining watertightness. In this joint pipe, the base end of the connecting pipe is loosely inserted over a predetermined length with a seal member inserted between the gaps.

[0010] It is preferable that a guide tube portion that can be inserted into a mounting hole of a manhole be provided at a base end of the joint pipe.

It is preferable that at least the opening end near the bottom of the pipe, which is formed between the outer peripheral surface of the connecting pipe and the inner peripheral surface of the joint pipe, is closed by a telescopic or flexible closing member. .

According to the present invention, on the outer peripheral wall of the manhole,
A joint pipe with a diameter larger than the outer diameter of the connecting pipe is fixed, and the connecting pipe is loosely inserted into this fitting pipe. By appropriately designing the pipe diameter of the fitting pipe, a large bending space is formed in the fitting pipe. And the flexibility of the connection pipe can be increased.

Further, since the connecting pipe is not inserted into the manhole unlike the related art, the connecting pipe is not damaged by contacting the manhole or the like.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a first embodiment of the present invention.
A mounting hole 2 is provided.

In the mounting hole 2, a guide tube portion 3b connected to the base end of the small-diameter portion 3a of the iron-made joint pipe 3 is loosely inserted to a position substantially aligned with the inner peripheral surface of the manhole 1. The gap formed between the inner surface of the mounting hole 2 and the outer peripheral surface of the guide cylinder 3b is sealed by inserting an O-ring 4.

A circular and curved mounting plate 5 is continuously provided on the outer peripheral surface of the small diameter portion 3a.
Are fixed to the manhole 1 by inserting bolts 7 into a plurality of female screw anchors 6 embedded in the outer peripheral wall of the manhole 1. Note that the inside diameter of the small diameter portion 3a is slightly smaller than the outside diameter of the connection tube 8 described later so that the connection tube 8 is not inserted into the small diameter portion 3a.

In the large-diameter portion 3c of the joint pipe 3, the base end of the connection pipe 8 formed by covering the inner and outer peripheral surfaces of the concrete pipe with fiber reinforced plastic (FRP) is substantially the same as the large-diameter portion 3c. It is loosely inserted over half the length. The pipe diameter of the large diameter portion 3c is sufficiently larger than the outer diameter of the connection pipe 8, and an inward annular piece whose inner peripheral edge is close to the outer peripheral surface of the connection pipe 8 is provided at the open end of the large diameter portion 3c. 3b are provided continuously.

A rubber seal ring 10 is fitted into an annular groove 9 formed on the inner peripheral surface of the open end of the large diameter portion 3 c, and the inner peripheral surface thereof is pressed against the outer peripheral surface of the connection pipe 8. By doing so, watertightness is maintained.

In the first embodiment, when a bending load acts on the connecting pipe 8 due to an earthquake or the like, the connecting pipe 8
In c, it is possible to bend by those gaps. The amount of bending at this time is as follows:
Is not inserted into the mounting hole 2, the size can be increased irrespective of the diameter of the mounting hole 2.

That is, since the design of the diameter of the large-diameter portion 3c can be freely changed according to the outer diameter of the connecting pipe 8, a large bending space can be formed in the large-diameter portion 3c.
Therefore, unlike the conventional one, there is no danger that the base end of the connection pipe 8 will be damaged by contacting the mounting hole 2 of the manhole 1 or the invert 11 inserted into the manhole 1.

Further, the size of the mounting hole 2 of the manhole 1 may be a minimum hole diameter for securing a required flow rate, and does not affect the strength of the manhole 1.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, the distance between the inner peripheral surface of the large diameter portion 3c of the joint pipe 3 and the outer peripheral surface of the base end of the connecting pipe 8 is shown. The gap S is closed by inserting an elastic filler 12 such as urethane sponge.

In this way, it is possible to prevent impurities contained in the fluid from entering and accumulating in the gap S, thereby preventing the flexibility of the connection pipe 8 from being hindered.

FIG. 3 shows a third embodiment of the present invention. In this embodiment, a bellows-like sealing member 13 extending toward the manhole 1 is provided on the outer peripheral surface of the base end of the connecting pipe 8. The small diameter portion 3a and the large diameter portion 3 of the joint pipe 3 are fixed.
The opening of the gap S is closed by being pressed against the step with c.

In this embodiment as well, it is possible to prevent foreign substances from accumulating in the gap S, so that the flexibility of the connection pipe 8 is not hindered. In addition, since the contaminants contained in the fluid easily accumulate near the bottom of the tube, the above-described closing member such as the filler 12 or the sealing member 13 may be provided only near the bottom of the tube. .

The present invention is not limited to the above embodiment.

For example, the guide tube portion 3b of the joint pipe 3 is omitted so as not to be inserted into the mounting hole 2 of the manhole 1, and the mounting plate 5 is directly mounted on the peripheral wall of the manhole 1 while maintaining watertightness. Is also good.

In some cases, the small-diameter portion 3a is not formed, and only the large-diameter portion 3c having a larger diameter than the connecting pipe 8 is provided.

The seal ring 10 for the joint pipe 3
The fixing method of is not limited to the above embodiment,
A structure in which the seal ring 10 is interposed between the flange 3e and the retaining ring 14 as shown in FIG. In particular, according to this configuration, the connection between the two pipes is facilitated by tightening the bolt 15 after inserting the connection pipe 8 into the joint pipe 3.

[0031]

According to the present invention, since the connecting pipe is inserted into the joint pipe without inserting it into the manhole, a large bending space can be formed in the joint pipe.
The flexibility of the connecting tube can be increased.

Further, since the connecting pipe is not inserted into the manhole, even if the connecting pipe is bent, it is not damaged.

According to the second aspect of the present invention, the joint pipe can be easily positioned and fixed around the mounting hole of the manhole, thereby improving workability.

According to the third aspect of the present invention, foreign matters are prevented from entering and accumulating in the gap between the connection pipe and the joint pipe, so that the flexibility of the connection pipe is not obstructed.

[0035]

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view showing a first embodiment of the present invention.

FIG. 2 is a partially cutaway plan view showing the second embodiment.

FIG. 3 is a partially cutaway plan view showing a third embodiment.

FIG. 4 is a local sectional view showing another embodiment of a connection portion between a joint pipe and a connection pipe.

FIG. 5 is a partially cutaway plan view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Manhole 2 Mounting hole 3 Joint pipe 3a Small diameter part 3b Guide cylinder part 3c Large diameter part 3d Inward annular piece 3e Flange 4 O ring 5 Mounting plate 6 Female screw anchor 7 Bolt 8 Connection pipe 9 Ring groove 10 Seal ring 11 Invert 12 Filling material (Closing member) 13 Seal member (Closing member) 14 Retaining ring 15 Bolt S Clearance

Claims (3)

[Claims] 1. A joint structure for connecting a connection pipe through which a fluid in a manhole flows to an attachment hole formed in a side wall of the manhole so as to be able to communicate with the connection pipe, wherein an outer peripheral wall of the manhole around the attachment hole. A joint pipe of a required length having a diameter larger than the outer diameter of the connection pipe is fixed while maintaining watertightness, and the base end of the connection pipe is inserted into the joint pipe in a gap between each other. A joint structure between a manhole and a connecting pipe, wherein a sealing member is inserted and loosely inserted over a predetermined length. 2. The joint structure between a manhole and a connecting pipe according to claim 1, wherein a guide tube portion insertable into a mounting hole of the manhole is provided at a base end of the joint pipe. 3. An opening end at least near the bottom of the pipe, which is formed between the outer peripheral surface of the connecting pipe and the inner peripheral surface of the joint pipe,
The joint structure between a manhole and a connection pipe according to claim 1 or 2, wherein the joint structure is closed by a closing member having elasticity or flexibility.