JP2003034940A - Precast manhole with a joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost precast manhole with a joint by which a joint pipe can easily be fixed to the manhole without disturbing but smoothing sewage flow. SOLUTION: In this precast manhole with a joint, a thru connection hole 12 is a stepped type consisting of a small diameter part 16 located at an inner position on the diameter of manhole body 8 and a large diameter part 17 located at an outer position on it; an insertion part 14 of a joint tube 14 made of a flexible tubular member connected within the connection hole 12 is forcibly fitted in the large diameter part 17 of this connection hole 12; and the inner diameter D1 of the small diameter part 16 of connection hole 12 and the inner diameter D2 of the insertion part 14 of joint tube 13 are made equal to the inner diameter D3 of sewage pipe 22 fitted in the reception opening 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast manhole with a joint in which a joint pipe to which a sewer pipe can be connected is previously fixed to a side wall.

[0002]

2. Description of the Related Art Generally, a method of connecting a sewer pipe to a manhole is to insert a sewer pipe into a connection hole formed in a side wall of the manhole, and then make a gap between the sewer pipe and the connection hole with a sealer and a mortar. A wet method of filling and sealing is used. However, this wet method has the drawbacks that the mortar application is troublesome and that water leakage easily occurs due to cracks in the mortar. Therefore, a precast manhole with a joint in which a joint pipe to which a sewer pipe can be connected is previously fixed to a side wall is already on the market, and FIG. 5 shows a conventional example of such a precast manhole.

That is, as shown in FIG. 5, a conventional precast manhole 31 with a joint has a precast manhole body 34 having a through hole 32 formed in a side wall 33 and a coaxial center with respect to the connection hole 32. And a joint pipe 35 made of a tubular member fixed to the outer peripheral surface of the manhole body 34 so as to form a shape. The joint pipe 35 is a flange portion fastened to the outer peripheral surface of the manhole body 34 with a bolt 36. 37 and this flange part 3
7 and a receiving port portion 38 extending outward from the diameter of the manhole body 34.

Therefore, this precast manhole 31
According to this, after the manhole main body 34 is installed at the construction site, the sewer pipe 39 is attached to the outer periphery of the receiving portion 38 of the joint pipe 35.
By fitting the sewer pipe 39 into the manhole main body 3
4 can be connected by dry method without using mortar.

[0005]

In the conventional precast manhole 31, the joint pipe 35 is fixed to the manhole body 34 by fastening the flange portion 37 to the outer peripheral surface of the manhole body 34 with a plurality of bolts 36. Therefore, the joint pipe 35 is connected to the connection hole 32.
It is necessary to fasten the plurality of bolts 36 while positioning them coaxially with each other, which results in a large number of man-hours in the factory and a high manufacturing cost.

On the other hand, in order to solve the above-mentioned drawbacks of the prior art, the joint pipe 35 without the flange 37 is connected to the connection hole 3.
2 may be forcibly fitted into the inside of the joint 2. However, when the joint pipe 35 is fitted into the connection hole 32 formed of a simple round hole, the pipe end of the joint pipe 35 is located inside the connection hole 32, and a step is formed. Therefore, it becomes difficult for the sewage to flow smoothly due to the step formed by the pipe end, and a new inconvenience occurs that foreign substances are likely to accumulate inside the manhole body 34. In view of such a situation, the present invention makes it possible to easily fix the joint pipe to the manhole main body without obstructing the flow of sewage, and to provide a precast manhole with a smooth joint at a low cost. To aim.

[0007]

In order to achieve the above object, the present invention takes the following technical means. That is, the present invention comprises a precast manhole main body having a through-hole-shaped connection hole punched in the side wall, and a joint pipe made of a flexible tubular member connected in the connection hole, The joint pipe is forcibly fitted into the connection hole, and a receiving port is provided coaxially with the insertion portion so as to extend from the insertion portion to the radially outer side of the manhole body. In a precast manhole with a joint composed of a portion, the connection hole comprises a stepped hole having a small diameter portion located inside the manhole body and a large diameter portion located outside the manhole body. The insertion portion of the joint pipe is forcibly fitted into the large diameter portion of the connection hole, and the inner diameter of the small diameter portion of the connection hole and the inner diameter of the insertion portion of the joint pipe are set to the receiving portion. Characterized in that it is set to be the same dimension as the inner diameter of the sewer pipe to be fitted in the mouth portion.

According to the present invention described above, the connection hole is a stepped hole having a small diameter portion on the inner side of the manhole diameter and a large diameter portion on the outer side of the same diameter, and the insertion portion of the joint pipe is inserted into the large diameter portion of the connection hole. Since it is forcibly fitted, the joint pipe can be easily fixed to the manhole body without requiring the positioning work for the connection hole and the bolt fastening work for the manhole body unlike the conventional case, and the precast manhole The manufacturing cost can be reduced. Further, according to the present invention, the inner diameter of the small diameter portion of the connection hole,
Since the inner diameter of the insertion part of the joint pipe and the inner diameter of the sewer pipe fitted in the receiving part are all set to the same size, all the inner peripheral surfaces from the small diameter part of the connection hole to the inside of the sewer pipe should be flush. Therefore, the flow of sewage is not obstructed by the pipe ends of the joint pipe and the sewage pipe, and a smooth flow of sewage is ensured.

In the above-mentioned present invention, a diameter-expanding ring having a function of pressing the insertion portion radially outwardly by enlarging the circumferential length by fitting it into the circumferential groove portion formed on the inner peripheral surface of the insertion portion may be fitted. For example, the fixing force of the joint pipe to the manhole body can be increased, and the sealing performance at the insertion portion of the joint pipe can be improved. In this case, if the inner diameter of the expanding ring is set to be the same as the inner diameter of the small diameter portion of the connection hole when the expanding ring is provided, the joint will be provided together with the expanding ring. It is possible to prevent unevenness on the inner surface of the pipe and ensure a smooth flow of sewage.

On the other hand, if the diameter-expanding ring having a U-shaped cross-section whose inner peripheral side is open is adopted,
The rigidity of the expanding ring can be increased, and the fixing force of the joint pipe can be further improved. In this case, if the spacer ring having flexibility is filled in the cross section of the expanding ring, the inner surface of the joint pipe is accompanied by the adoption of the expanding ring having the U-shaped cross section. It is possible to prevent unevenness on the surface and ensure a smooth flow of sewage.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention, in which FIG. 3 shows a construction example (longitudinal sectional view) of a sewer pipe structure using the precast manhole 1 of the present invention. As shown in FIG. 3, the sewage piping structure of the present embodiment has a precast manhole 1 installed on a support layer composed of quarry stones 2 and discarded concrete 3.
And a manhole cover frame 6 made of cast iron fixed to the upper end of the manhole 1 via anchor bolts 4 and adjusting mortar 5.

The precast manhole 1 is constructed by vertically stacking a plurality of concrete manhole bodies 8 and 10 formed by a dry cast method or the like. Of the plurality of manhole bodies 8 and 10, the invert cylinder body 8 located at the bottom has a hemispherical invert surface 9 on the bottom surface, and the intermediate cylinder body 10 stacked on top of the invert cylinder body 8 is It is formed in a bottomless tubular shape having the same diameter as the invert tubular body 8 and penetrating in the vertical direction. Of the manhole main bodies 8 and 10, the side wall 11 of the invert cylinder 8 has the side wall 11
A connection hole 12 penetrating the manhole in the radial direction,
A joint pipe 13 made of a flexible tubular member such as hard rubber is fixed in the connection hole 12 in a state where the joint pipe 13 is fitted in advance in a factory or the like.

As shown in FIG. 1, this joint pipe 13
Is an insertion portion 14 that is forcibly fitted into a large diameter portion 17 of the connection hole 12 which will be described later, and is coaxial with the insertion portion 14 so as to extend from the insertion portion 14 to the radially outer side of the invert cylinder 8. It is configured by a receiving portion 15 extending in a heart shape.
In the illustrated example, only the invert cylinder 8 has the joint pipe 1
Although 3 is fixed, the joint pipe 13 may be fixed to the other manhole body, that is, the intermediate cylinder 10. The connection hole 12 formed in the side wall 11 of the invert cylinder 8 has a small diameter portion 16 located on the radially inner side of the invert cylinder 8 and a large diameter portion 17 located on the radially outer side of the same. It is composed of three stepped holes having a maximum diameter part that is further expanded than the diameter part 17. On the contrary,
In the joint pipe 13, the outer diameter of the receiving portion 15 is the insertion portion 14
Is formed in a stepped cylindrical shape having a larger diameter than the outer diameter, and the axial length of the insertion portion 14 is set to be substantially the same as the axial length of the large diameter portion 17 of the connection hole 12. .

For this reason, when the insertion portion 14 is forcibly fitted into the large diameter portion 17 of the connection hole 12 and the joint pipe 13 is inserted into the inside, the pipe end of the joint pipe 13 has a small diameter portion 1.
6 is abutted on the step 19 between the large diameter portion 17 and the outer peripheral step of the joint pipe 13 is abutted on the step 20 between the large diameter portion 17 and the maximum diameter portion, the fitting is restricted. The insertion depth of the joint pipe 13 is regulated by. A storage recess 21 is formed on the inner peripheral side of the receiving portion 15 of the joint pipe 13, and the storage recess 21 is formed.
By forcibly fitting the sewer pipe 22 inside,
The sewer pipe 22 can be connected to the invert cylinder 8 by a dry method only by fitting. On the other hand, a peripheral groove portion 23 is formed on the inner peripheral surface of the insertion portion 14 of the joint tube 13, and has a function of pressing the insertion portion 14 radially outward by enlarging the peripheral length in the peripheral groove 23. The expanded ring 24 is fitted.

As shown in FIG. 2, the diameter-expanding ring 24 of this embodiment is formed by winding a metal strip having a U-shaped cross section in an endless circular shape, and a part of the ring in the circumferential direction. , A fold-in portion 25 that is folded in a V shape on the inner side of the diameter. Therefore, the expanded ring 24 is inserted into the insertion portion 14
After being fitted into the circumferential groove portion 23 of the, the fold-in portion 25 is pushed outward by the jack to radially expand the ring 2.
4 is enlarged and the insertion part 14 is pressed against the side wall 11, thereby increasing the fixing force of the joint pipe 13 to the invert cylinder 8 and improving the sealing performance of the insertion part 14 of the joint pipe 13. I have to.

The work of tightening the expanded ring 24 is performed in the factory together with the work of fitting the joint pipe 13. Further, the expanding ring 24 may employ a band member having a simple plate-shaped cross section, but the expanding ring 24 of the present embodiment is formed in a U-shaped cross section having an opening on the inner peripheral side. Therefore, the rigidity is higher than that of the band member having a simple plate-shaped cross section, and the fixing force of the joint pipe 13 can be further improved. As shown in FIG. 1, in the present embodiment, the inner diameter D of the small diameter portion 16 of the connection hole 12 is
1. The inner diameter D2 of the insertion portion 14 of the joint pipe 13 is set to be substantially the same as the inner diameter D3 of the sewage pipe 22 fitted in the receiving portion 16. In addition, the insertion portion 14
The inner diameter D4 of the expanded ring 24 fitted in the circumferential groove portion 23 of the expanded ring 24 is set to be substantially the same as the inner diameter of the small diameter portion 16 of the connection hole 12.
A rubber spacer ring 2 having flexibility in the cross section of
6 is filled.

Therefore, the invert cylinder 8 of this embodiment is
According to this, in the state where the sewer pipe 22 is fitted into the joint pipe 13, the sewer pipe 22 is inserted from the small diameter portion 16 of the connection hole 12.
All the inner peripheral surfaces reaching the inside of the sewage will be flush with each other, and the smooth flow of sewage will be ensured without the flow of sewage being blocked by the ends of the joint pipe 13 and the sewage pipe 22. Has become. FIG. 4 shows a second embodiment of the present invention. The difference of this embodiment from the first embodiment is that the outer peripheral shape of the joint pipe 13 is formed in a cylindrical shape without steps, and accordingly, the connection hole 12 is formed.
The maximum diameter part is omitted. Since the other configurations and operations are the same as those in the first embodiment, the same reference numerals as those in the first embodiment are attached to FIG.
Detailed description thereof will be omitted.

The present invention is not limited to the above-described embodiments. For example, the joint pipe 13 may be connected only to the outflow side of the side wall 11 and the joint pipe 13 having a different structure may be adopted to the inflow side. it can. Further, in the above embodiment, the precast manhole 1 is divided into the invert cylinder 8 and the intermediate cylinder 10, but the joint pipe 13 is connected to the integrated precast manhole 1 which is not vertically divided. You can also

[0019]

As described above, according to the present invention,
Since the joint pipe can be easily fixed to the manhole body without obstructing the flow of sewage, a precast manhole with a joint having a smooth flow of sewage can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a plan cross-sectional view of a sewer pipe connecting portion of a manhole according to a first embodiment.

FIG. 2 is a front view of a diameter expansion ring.

FIG. 3 is a vertical sectional view showing an example of construction of a sewer piping structure.

FIG. 4 is a plan cross-sectional view of a sewer connection part of a manhole according to a second embodiment.

FIG. 5 is a cross-sectional plan view of a conventional sewer connection part of a manhole.

[Explanation of symbols]

1 precast manhole 8 Invert cylinder (manhole body) 10 Intermediate cylinder (manhole body) 11 Side wall 12 connection holes 13 joint pipe 14 insertion part 15 Receiving part 16 Small diameter part 17 Large diameter part 22 Sewer pipe 23 Circumferential groove 24 Expanding ring 25 Folding part 26 Spacer ring

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahiro Tsukamoto             6-14 Nakatsu, Nakatsu, Kita-ku, Osaka-shi, Osaka Stocks             Company Itoyokyo (72) Inventor Hiroaki Miyama             6-14 Nakatsu, Nakatsu, Kita-ku, Osaka-shi, Osaka Stocks             Company Itoyokyo F-term (reference) 2D047 BA27

Claims (3)

[Claims] 1. The side wall (11) has a through-hole connection hole (12).
Precast manhole body (8)
And a joint pipe (13) made of a flexible tubular member connected to the inside of the connection hole (12), and the joint pipe (13) is connected to the connection hole (12).
The insertion portion (14) that is forcibly fitted inside, and extends coaxially with respect to the insertion portion (14) so as to extend from the insertion portion (14) to the radially outer side of the manhole body (8). In a precast manhole with a joint, which is composed of a receiving portion (15) provided, the connection hole (12) and the manhole body (8) are the same as the small diameter portion (16) located inside the manhole body (8). )
And a large-diameter portion (17) located on the outer diameter side of the connecting hole (12).
The insertion portion (14) of the joint pipe (13) is forcibly fitted into the inside of (7), and the inner diameter (D1) of the small diameter portion (16) of the connection hole (12) and the joint pipe (13). Precast with joint, characterized in that the inner diameter (D2) of the insertion portion (14) is set to be the same as the inner diameter (D3) of the sewer pipe (22) fitted in the receiving portion (15). manhole. 2. A diameter-expanding ring (24) having a function of pressing the insertion portion (14) radially outward by enlarging the circumferential length of a circumferential groove portion (23) formed on the inner peripheral surface of the insertion portion (14). ) Is fitted, and the inner diameter (D4) of the expanded ring (24) when expanded is set to be approximately the same as the inner diameter (D1) of the small diameter portion (16) of the connection hole (12). The precast manhole with a joint according to claim 1. 3. The expanding ring (24) has a U-shaped cross section whose inner peripheral side is open.
The precast manhole with a joint according to claim 2, wherein a flexible spacer ring (26) is filled in a cross section of the precast manhole.