JP2854554B2 - Flexible concrete pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible concrete pipe buried underground, which can cope with a large displacement due to an earthquake, ground deformation, etc., and also reduces the flexing of the flexible joint to the inner peripheral side. It is made possible.

[0002]

2. Description of the Related Art Concrete pipes, such as fume pipes, buried and constructed by the propulsion method or the open-cutting method, may have a difference in settlement amount due to ground deformation or leakage from the joint due to external force due to earth pressure such as an earthquake. In some cases, breakage of the concrete pipe may occur.

For this reason, a flexible concrete pipe in which a flexible joint is previously provided integrally in the middle of a concrete pipe has been proposed, and by using the pipe at predetermined intervals, the flexibility of the flexible joint is reduced. Elastic deformation and shape deformation) allow for differences in external forces and settlements due to earthquakes, ground changes, and the like.

[0004] As such a flexible concrete pipe, for example, a pipe disclosed in Japanese Utility Model Publication No. Hei 4-10468, as shown in FIG.
A flexible cylindrical body 4 having an anchor 4a made of a rubber-like substance is provided so as to sandwich a joint cushioning material 3 made of rubber or the like between the end faces 2b and to surround and connect the outer periphery of the end. An annular body 5 having a large number of punched holes 5a is provided, and these are integrated with concrete in a mold using centrifugal force.

[0005] In this flexible concrete pipe 1, the external force such as earth pressure reaches a predetermined value, the external force is received by the ring 5 made of thin steel plate, and when the external force exceeds the predetermined value, the ring 5 Plastic deformation or breakage is generated at the punched hole 5 a formed in the hole 5, and displacement or the like is absorbed by utilizing the flexibility of the flexible tubular body 4.

Further, as shown in FIG. 12, a flexible concrete pipe 6 disclosed in Japanese Utility Model Publication No. 4-12150 has step portions formed on the outer periphery of the ends of two fume pipe members 7a and 7b. A metal flanged cylinder 8 is attached to the stepped portion and the end face by an anchor bolt 8a, and a rubber flexible portion 9 is vulcanized and bonded so as to extend between the flanges of the flanged cylinder 8 and the outer periphery of the cylinder. Has been

The flexible concrete pipe 6 absorbs external force and displacement such as earth pressure by utilizing the flexibility of the rubber flexible portion 9.

[0008]

However, in the flexible concrete pipe 1 which is made of a thin steel plate and has the ring body 5 formed with the punched hole 5a and the flexible tubular body 4, the external force such as earth pressure is limited to a predetermined value. If the value exceeds the value, the ring 5 is cut from the punched hole 5a, so that after the cut, the external force and displacement must be received only by the flexible cylinder 4, and the large displacement is absorbed. Can not do it.

Further, in the flexible concrete pipe 6 in which the rubber flexible portion 9 is bonded to the flanged cylinder 8, the rubber flexible portion 9 is expanded and contracted in response to an external force such as earth pressure to absorb the displacement.
There is a limit to the deformation allowance of the rubber flexible portion 9, and a large displacement cannot be absorbed.

On the other hand, in order to cope with a large displacement in response to an external force such as earth pressure, if the joint cushioning material 3 and the rubber flexible portion 9 are enlarged in the axial direction to increase the deformation allowance, When this external force is applied, this portion is largely bent to the inner peripheral side, and particularly at the bottom portion, problems such as accumulation of sewage dirt and rot due to stagnant water flow occur.

The present invention has been made in view of such problems of the prior art, and can absorb a large amount of displacement in response to a large displacement due to an earthquake, ground deformation, and the like, and can prevent bending. It is an object of the present invention to provide a flexible concrete pipe capable of preventing the accumulation of sewage waste and the like.

[0012]

According to a first aspect of the present invention, there is provided a flexible concrete pipe having a flexible joint provided with a front and rear pipe member made of concrete. An annular frame body which is abutted on the rear end face of the front pipe member and the front end face of the rear pipe member and has a smaller diameter than the front and rear pipe members, and a pair of parallel frame members provided between the two frame bodies. An annular holding plate, an annular mounting portion at both ends sandwiched between the frame body and the holding plate, and an inner circumferential surface of the front and rear pipe members by connecting these annular mounting portions on the inner circumferential side. And a tubular flexible telescopic member having an annular reinforcing rib integrally formed by projecting toward the intermediate outer peripheral side of the annular connecting portion, The annular housing of the frame and the elastic member embedded in the front and rear pipe members. A plurality of mounting bolts which are screwed into the holding plate through the portion and tighten the annular mounting portion of the elastic member, and an annular protective cover provided between the front and rear pipe members and along the outer peripheral surface of these front and rear pipe members And characterized in that:

According to this flexible concrete pipe, an annular frame body is applied to the facing end faces of the concrete front pipe member and the rear pipe member, and a pair of pressing plates are arranged in parallel between the two frames.
A frame body and a holding plate are provided by mounting bolts embedded in the holding plate at both ends of a cylindrical elastic member that protrudes to the outer peripheral side of the intermediate annular connecting portion and is reinforced by a rib formed integrally. The fixing bolts are fixed in place, the mounting bolts are penetrated through the frame, embedded in concrete, and the outside of the frame is covered with a protective cover. At the same time, a large amount of displacement can be absorbed by the annular connecting portion of the member, and at the same time, the bending to the inner peripheral side is prevented by the annular reinforcing rib.

A flexible concrete pipe according to a second aspect of the present invention is a flexible concrete pipe provided with a flexible joint between the front and rear pipe members made of concrete.
An annular pressing plate abutting on the rear end surface of the front pipe member and the front end surface of the rear pipe member, and an annular frame body provided in parallel between the two pressing plates and having a smaller diameter than the front and rear pipe members;
An annular mounting portion at both ends sandwiched between the holding plate and the frame, and an annular portion at an intermediate portion along the inner peripheral surface of the front and rear pipe members by connecting these annular mounting portions on the inner peripheral side. A cylindrical flexible extensible member having a connecting portion and having an annular reinforcing rib integrally formed by protruding toward an intermediate outer peripheral side of the annular connecting portion; the frame body; and the extensible member A plurality of attachments that penetrate the annular attachment portion and the holding plate and tighten the annular attachment portion of the elastic member with the holding plate and the frame, and the tip of the penetration portion is embedded in the front and rear pipe members. It is characterized by comprising a bolt and an annular protective cover provided between the front and rear pipe members and along the outer peripheral surface of these front and rear pipe members.

According to this flexible concrete pipe, an annular pressing plate is applied to the opposed end faces of the front and rear pipe members made of concrete, and a pair of frames are arranged in parallel between the two.
The both ends of the tubular elastic member reinforced by the ribs integrally formed on the outer peripheral side of the intermediate annular connecting portion are sandwiched between the holding plate and the frame, and the mounting bolt is passed through from the outside of the frame. In addition to tightening the elastic member and fixing it, the penetrated tip of this mounting bolt is embedded in concrete to serve as an anchor, and the outside of the frame is covered with a protective cover. While protecting, it is possible to absorb a large amount of displacement with the connecting part of the expansion and contraction member, and at the same time, it is necessary to prevent bending to the inner peripheral side with annular reinforcing ribs, and to form screws on the holding plate and frame body To make it easy to assemble.

Further, the flexible concrete pipe according to a third aspect of the present invention is a flexible concrete pipe having a flexible joint between the front and rear pipe members made of concrete, wherein the front pipe is provided. An annular frame body abutting on the rear end surface of the member and the front end surface of the rear pipe member, a pair of parallel holding plates provided between the two frame bodies in parallel with each other, and having a smaller diameter than the front and rear pipe members; An annular convex portion at both ends covering the pressing plate from the outer peripheral side, and an annular connecting portion connecting these annular convex portions along the inner peripheral surface of the front and rear pipe members, and an intermediate portion between the annular connecting portions. A cylindrical flexible telescopic member having an annular reinforcing rib protruding to the outer peripheral side and integrally formed therewith, and the frame abutting the frame and the telescopic member embedded in the front and rear pipe members; Screwed into the holding plate A plurality of mounting bolts for tightening the mounting portion of the contraction member, provided between the front and rear tube member is characterized in that made in the protective cover of the annular along the outer peripheral surfaces of the front and rear tube member.

According to this flexible concrete pipe, an annular frame is applied to the opposed end faces of the front and rear pipe members made of concrete, and a pair of pressing plates are disposed in parallel between the annular frame bodies.
The frame is covered with mounting bolts embedded in the holding plate so as to cover from outside with the annular convex portions at both ends of the tubular elastic member reinforced by ribs integrally formed on the outer peripheral side of the intermediate annular connecting portion. The fixing member is tightened and fixed in between, and the mounting bolt is penetrated through the frame, embedded in concrete, and the outside of the frame is covered with a protective cover. A large amount of displacement can be absorbed by the annular convex portion of the elastic member and the annular connecting portion while protecting, and at the same time, the bending to the inner peripheral side is prevented by the annular reinforcing rib.

Further, the flexible concrete pipe according to a fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects, further comprises an annular reinforcing member formed on the flexible elastic member. Characterized by a plurality of ribs.

According to this flexible concrete pipe, a plurality of reinforcing ribs are formed integrally with the elastic member so that the rigidity of the connecting portion can be further increased. The flexure between ribs and the like is reduced to reduce the overall flexure amount.

According to a fifth aspect of the present invention, in addition to the configuration described in any of the first to fourth aspects, the flexible reinforcing pipe of the elastic member has an annular reinforcing rib. An annular ring is attached.

According to this flexible concrete pipe, an annular ring is attached to the reinforcing rib of the elastic member,
The ring is made of metal or synthetic resin so that the rigidity of the flexible rib can be increased, and the bending of the connecting portion can be further reduced. To be able to.

According to a sixth aspect of the present invention, there is provided a flexible concrete pipe according to any one of the first to fifth aspects, wherein the protective cover has a slit parallel to an axial direction of the front and rear pipe members. Are formed in plurality.

According to this flexible concrete pipe, a plurality of slits are formed in the protective cover in the axial direction, so that the protective cover can be smoothly deformed against external force such as earth pressure without being cut without expanding and contracting. The members can be protected.

According to a seventh aspect of the present invention, there is provided a flexible concrete pipe according to any one of the first to sixth aspects, further comprising a joint between the protective cover and the pair of frames. One is intermittent welding and the other is spot welding.

According to this flexible concrete pipe, one of the joints between the protective cover and the frame is intermittently welded and the other is spot welded, and a large axial force is applied to the protective cover. In this case, the spot welds are broken to make them correspond, and the state in which the elastic member is covered with the protective cover can be maintained.

Further, the flexible concrete pipe according to claim 8 of the present invention, in addition to the configuration according to any one of claims 1 to 7, further includes an outer peripheral side of an annular connecting portion of the elastic member and the protective cover. Is filled with a joint material.

According to this flexible concrete pipe, the space between the outer peripheral side of the annular connecting portion of the elastic member and the protective cover is filled with the joint material, and the joint material is further cooperated with the protective cover. It is possible to reliably prevent earth and sand from entering the outer peripheral side of the annular connecting portion of the elastic member, and to more reliably support bending of the waterproof rubber due to external water pressure passing through the protective cover.

A flexible concrete pipe according to a ninth aspect of the present invention is characterized in that, in addition to the configuration according to the eighth aspect, the joint material is constituted by a plurality of joint materials having different characteristics. It is.

According to this flexible concrete pipe, the joint material is constituted by a plurality of joint materials having different characteristics. For example, the Young's modulus of compression is preferably higher from the viewpoint of reinforcement against external water pressure. The lower the better, so as not to hinder the contraction displacement of the elastic member, the higher the Young's modulus of the joint material on the outer side where the external water pressure acts directly, the inner joint material affecting the contraction displacement To lower the Young's modulus.

Further, the flexible concrete pipe according to claim 10 of the present invention, in addition to the structure according to any one of claims 1 to 9, further comprises an abutting portion between the frame and the end faces of the front and rear pipe members. And a ring-shaped water-stop member is provided.

According to this flexible concrete pipe, a water-stopping member is provided between the frame body and the end face of the concrete pipe member. Try to prevent.

The large displacement means that the displacement is increased as compared with the conventional product.
0mm, shrinkage 0mm, settlement shear 30mm
More than that, for example, each of the above values is set to 50 mm or more.

[0033]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 relate to an embodiment of the flexible concrete pipe of the present invention,
FIG. 1 is an enlarged sectional view of the flexible joint, and FIG. 2 is a longitudinal sectional view of only the upper half thereof.

The flexible concrete pipe 10 is provided with a front pipe member 11 and a rear pipe member 12 formed by centrifugal reinforced concrete pipes (fume pipes), respectively, and is provided between the front and rear pipe members 11 and 12. And a flexible joint portion 13 for connecting these components, and these components are integrated in a mold for centrifugal molding.

The flexible joint portion 13 of the flexible concrete pipe 10 is brought into contact with an annular front frame 14 made of a metal plate and a front end face of the rear pipe member 12 which is brought into contact with the rear end face of the front pipe member 11. There are provided two frames composed of an annular rear frame 15, and the two front and rear frames 14, 15 are arranged at an interval. The front frame 1 which is these two annular frames
The outer diameter of the front and rear frame members 4 and 15 is slightly smaller than the outer diameter of the front and rear pipe members 11 and 12 (corresponding to the thickness of the protective cover described later), and the inner diameter is substantially the same as the inner diameter of the front and rear pipe members 11 and 12. A plurality of through holes 16 for fixing are formed in the middle part at equal intervals in the circumferential direction.

An annular front holding plate 17 and a rear holding plate 18 are disposed between the two front and rear frames 14 and 15 in parallel with the front and rear frames 14 and 15. , 18 constitute a pair of holding plates. These one
The pair of holding plates 17 and 18 are made of a metal plate, the outer diameter is set to the size of the middle part between the inner and outer diameters of the front and rear pipe members 11 and 12, and the inner diameter is larger than the inner diameter of the front and rear pipe members 11 and 12 (to be described later). ) Is formed smaller by the thickness of ()). The front and rear holding plates 17 and 18 are the same as the through holes 16 of the front and rear frames 14 and 15 in a state where the female screw portions 17a and 18a are bottomed from the front and rear frames 14 and 15 side to the middle part of the plate thickness, respectively. A plurality are formed on the circumference with the above arrangement.

Between the front and rear frame members 14 and 15 and the front and rear holding plates 17 and 18, a flexible tubular elastic member 1 is provided.
Nine annular mounting portions 20 and 21 at both ends are sandwiched.

The cylindrical elastic member 19 has disk-shaped (annular) attachment portions 20 and 21 formed at both ends (front and rear portions).
A cylindrical connecting portion 22 is integrally formed such that the inner peripheral sides of the front and rear annular mounting portions 20 and 21 are connected to form a concave cross section. The outer diameters of the annular front and rear mounting portions 20 and 21 of the tubular elastic member 19 are adjusted to the front and rear holding plates 17 and 1.
8, the inner diameter of the front and rear mounting portions 20, 21 of the elastic member 19 and the connecting portion 2.
2 is formed so that the inner diameter is substantially the same as the inner diameter of the front and rear pipe members 11 and 12.

An annular reinforcing rib 23 is formed on the intermediate outer peripheral side of the connecting portion 22 of the expansion / contraction member 19 so as to protrude toward the outer peripheral side and is integrally formed.

The annular reinforcing rib 23 reinforces that the annular connecting portion 22 of the elastic member 19 is deformed and bent inward by an external pressure or the like. Are thin in the axial direction, and have a vertically long rectangular cross-sectional shape with a high radial height.

Further, by making the reinforcing ribs 23 have such a longitudinal cross section, a margin for shrinkage when the front and rear pipe members 11, 12 are deformed so as to shrink is ensured. In order to prevent the reinforcing ribs 23 from being crushed, it is preferable that the ribs 23 be hard (having a high Young's modulus), have a wide shape (thickness in the axial direction), and have a high height (height in the radial direction). The higher the hardness, the better. However, since the hardness is determined by the material of the elastic member 19 because it is formed integrally with the elastic member 19, it cannot be made too hard.
/ Cm2 (the hardness is 50 to 65 Hs).

As the elastic member 19, for example, chloroprene rubber (CR) having excellent weather resistance and the like, EPDM and the like are used.

Further, a plurality of through holes for mounting are formed on the circumference of the annular mounting portions 20, 21 of the elastic member 19 in the same arrangement as the through holes 16 of the front and rear frames 14, 15.

In such an elastic member 19, the elastic member 1
The annular front and rear pressing plates 17 and 18 are mounted inside the annular front and rear mounting portions 20 and 21 by utilizing its flexibility.

Next, the through hole 1 for fixing the front frame 14
6. The through hole of the mounting portion 20 of the elastic member 19 and the front holding plate 17
And the stud bolts 25 as mounting bolts are inserted from the front frame body 14 side so that the front holding plate 1
7 and screwed into the female screw portion 17a, and the nut 26 screwed into the stud bolt 25 in advance, between the front frame 14 and the front holding plate 17, the mounting portion 20 of the elastic member 19
And fix it by tightening.

The fastening of the elastic member 19 on the front side is completed by tightening the stud bolt 25 and the nut 26 at a plurality of locations on the circumference in this manner.

Similarly, on the rear side of the elastic member 19, the nut 26 screwed into the stud bolt 25 beforehand is used to mount the elastic member 19 between the rear frame 15 and the rear holding plate 18.
Tighten and fix by sandwiching 1.

In the state where the front and rear mounting portions 20 and 21 of the elastic member 19 are fixed between the front frame 14 and the front pressing plate 17 and between the rear frame 15 and the rear pressing plate 18, A stud bolt 25, which is a bolt, protrudes forward or rearward, and this portion serves as an anchor portion 25a for concrete.

A metal cylindrical protective cover 27 is attached so as to close the outer peripheral sides of the front and rear frames 14 and 15 connected via the elastic member 19.

The protective cover 27 is provided between the front and rear pipe members 11, 1
2 and the front and rear pipe members 1
The length of the front and rear frame members 14,
15 corresponds to a portion where the outer diameter is slightly smaller than the outer diameters of the front and rear pipe members 11 and 12.

The protective cover 27 and the front corner of the front frame member 14 are connected by a spot welded portion 28 by spot welding, and the protective cover 27 and the rear corner of the rear frame member 15 are intermittent. They are connected at the welded intermittent welding portion 29 and are welded so that there is a difference in welding strength, and which of the spot welding and the intermittent welding may be appropriately selected.

The protective cover 27 and the front and rear frame members 14,
The intermittent welding used for connection with any one of the above 15 is welding that performs welding of a predetermined length at predetermined intervals in the circumferential direction,
For example, the welding length is set to about 30 mm at intervals of about 100 mm.

The spot welding used for connecting one of the protective cover 27 and the front and rear frame members 14 and 15 is as follows.
A weld whose welding length is shorter than intermittent welding.
Make the welding length about 5 mm at intervals of about mm. Thus, the assembly of the flexible joint 13 is completed.

The flexible joint 13 assembled in this way is installed in a centrifugal molding form together with a reinforcing bar 30 for reinforcing the front and rear pipe members 11 and 12, and is made of concrete in the same manner as a normal fume pipe. Front and rear pipe members 11 and 12
Is manufactured, and the flexible joint 13 is integrated with the intermediate portion between the front and rear pipe members 11 and 12.

Further, in this flexible concrete pipe 10, as shown in FIG.
1,12 axial directions (axial directions connected linearly)
A plurality of slits 31 are formed in parallel with. Each of the slits 31 has a length extending between the front and rear frames 14 and 15 and includes round holes at both ends and cuts connecting these holes.

In the flexible concrete pipe 10, the outer peripheral portion of the connecting portion 22 of the elastic member 19 and the protective cover 2
An annular joint material 41 is mounted in an annular space surrounded by 7. The joint material 41 serves to prevent the intrusion of earth and sand and water from the outside and also to reinforce the elastic member 19. The joint material 41 is made of, for example, sponge rubber with closed cells and small bubbles. Can be Further, an adhesive 42 is bonded between the joint material 41 and the outer periphery of the connecting portion 22 of the elastic member 19 and between the joint material 41 and the contact surfaces with the front and rear pressing plates 17 and 18.

The joint material 41 is a closed cell, and it is better that the Young's modulus of compression is high in terms of reinforcement against external water pressure, but it is better that the Young's modulus is low in order not to hinder the contraction deformation of the elastic member 19. , The Young's modulus of the initial compression is about 5-20 kg /
cm ² is appropriate.

The characteristics of the flexible joint portion 13 of the flexible concrete pipe 10 are determined by the shape and Young's modulus of the reinforcing rib 23 and the joint material 41 of the elastic member 19 described above. When the nominal diameter of the fume pipe is 300 mm or less, the external water pressure is 0.1 kg / cm ² (1
If the nominal diameter is 350 mm or more, the outer water pressure should be 0.15 kg / cm ² (1.5 m) or more.

That is, the buckling strength (crushing pressure) is represented by Pk
(Kg / cm ² ) can be obtained by the following equation.

Pk = k · (3 · E · I) / (R ³ ) Here, R is a radius, and E is a Young's modulus, for example, 50 kg / cm ² for rubber, and 7.5 kg / cm for sponge rubber. and cm ^2. Further, I is a second moment of area, and k is a constant determined by an experiment. For example, here, k = 3.2.

The shapes and dimensions of the elastic member 19 and the joint material 41 may be determined so as to satisfy the buckling strength Pk thus obtained.

Further, in the flexible concrete pipe 10, a water-stopping member 51 is attached in an annular shape to portions of the front and rear frames 14, 15 which are in contact with the concrete, so as to prevent water from entering from outside and sewage from inside. It is designed to prevent water leakage. As the water stopping member 51, a member made of, for example, water expanded rubber or non-vulcanized butyl rubber is used.

The flexible concrete pipe 10 constructed as described above is interposed at regular intervals of a normal concrete pipe, is buried underground, and is used as a pipe or the like.

By using the flexible concrete pipe 10, the bending of the connecting portion 22 of the expansion and contraction member 19 when an external pressure such as earth pressure is applied between the front and rear pipe members 11 and 12 is reduced by the reinforcing rib 23. As much as possible,
The flexible joint 13 can be displaced and absorbed by displacements such as extension and contraction.

As a result, it is possible to prevent sewage filth from accumulating on the bottom of the flexible concrete pipe 10 or causing water rot due to a stagnant flow.

Next, as shown in FIG. 4 showing a case where a large displacement occurs due to extension between the front and rear pipe members 11 and 12,
The connecting portions 22 are deformed so that the connecting portions 22 are stretched while the mounting portions 20 and 21 at both ends of the fixing member 9 are firmly fixed by being sandwiched between the front and rear frame members 14 and 15 and the front and rear pressing plates 17 and 18, to prevent external flooding and the like. Prevent water leakage from inside.

Further, against an external force such as earth pressure, the weaker point welded portion 28 of the joint between the protective cover 27 and the front and rear frame members 14 and 15 is broken, thereby protecting the joint. The cover 27 is received by the protective cover 27 in a state of covering the outer periphery of the flexible joint 13 without breaking.

Further, as shown in FIG. 5 showing a case where a large displacement due to shrinkage occurs between the front and rear pipe members 11 and 12, the annular mounting portions 20 and 21 at both ends of the expansion and contraction member 19 are attached to the front and rear frame members 1 and 12.
The connecting portion 22 and the joint material 41 of the inner portion are pressed and deformed by the front and rear holding plates 17, 18 while being firmly fixed and sandwiched by the front and rear holding plates 17, 18, and are deformed by external forces. Prevent inundation and leakage from inside. Even with this shrinkage, since the reinforcing rib 23 has a vertically long cross section that is thin in the axial direction and thick in the radial direction, the connecting portion 22 can be deformed without any trouble.

Then, the protective cover 27 and the front and rear frame members 14 and 15 are protected against external pressure such as earth pressure in the same manner as in the case of elongation.
The weaker point welded portion 28 which has been spot-welded at one of the joint portions is broken and received by the protective cover 27 in a state of covering the outer periphery of the flexible joint portion 13.

Further, not only the displacement due to settlement between the front and rear pipe members 11 and 12 but also the displacement due to torsion (rotation around the axial direction) between the front and rear pipe members 11 and 12 may occur. Since the slits 31 are formed in 27, as shown in FIG.
It is possible to maintain a state capable of receiving earth pressure or the like.

When a stronger torsional change occurs, one of the joints between the protective cover 27 and the front and rear frames 14, 15 is welded to the weaker spot welded portion 28, which is slid and rotated. Thus, a state capable of receiving earth pressure or the like can be maintained.

As described above, according to the flexible concrete pipe 10, even if an external force is applied to the connecting portion 22 of the expansion and contraction member 19, the deformation (bending) of the connecting portion 22 toward the inner peripheral side is prevented by the reinforcing rib. 23 minimizes the accumulation of sewage sewage on the bottom of the flexible concrete pipe 10 and the occurrence of water rot due to the stagnant flow. Even if a large displacement occurs due to contraction or the like, the displacement can be tolerated by the displacement of the elastic member 19.

Also, since the stud bolt 25 and the nut 26 are used for mounting the expansion and contraction member 19, the mounting bolt can be tightened without penetrating to the outside of the holding plates 17 and 18. Water from the threaded portion of the stud bolt 25 can be completely prevented.

Further, the front and rear pressing plates 17 and 18 for fixing the elastic member 19 do not come into contact with fluid such as sewage flowing in the pipe, and there is no problem such as corrosion.

Further, the protective cover 27 can prevent the expansion and contraction member 19 from being damaged due to earth pressure, earth and sand, etc.
A falling gradient of 1, 12 can be secured.

Further, the front and rear frames 14, 15 of the front and rear pipe members 11, 12 and the flexible joint 13 and the front and rear pressing plates 17, 1
8, since the elastic member 19, the annular reinforcing rib 23, the stud bolt 25, the nut 26, and the protective cover 27 are pre-assembled integrally, construction on site is easy,
In particular, damage to the elastic member 19 can be prevented.

Further, since the slit 31 is formed in the protective cover 27, the flexible joint 13 can be smoothly deformed by the displacement of the front and rear pipe members 11, 12. An external load slightly exceeding its own weight can hardly be deformed, and a large displacement can be obtained during uneven settlement or an earthquake.

Next, another embodiment of the present invention will be described in detail with reference to the drawings. FIG. 7 is an enlarged sectional view of a flexible joint according to another embodiment of the flexible concrete pipe of the present invention. FIG. 7 (a) shows an assembled state, and FIG. 7 (b) shows an external pressure. 3 shows the bending state due to

This flexible concrete pipe 60 is suitable for a pipe having a relatively small pipe diameter and a thin concrete portion, and is mainly used for the flexible joint portion 13 of the flexible concrete pipe 10 already described. Since the mounting structure of the elastic member 19 is changed, a different configuration will be described, and the flexible concrete pipe 1 already described.
The same portions as 0 are denoted by the same reference numerals and description thereof will be omitted.

In this flexible concrete pipe 60, the expansion and contraction member 19 constituting the flexible joint 13 is attached to the frame 6.
1. Pressing plates 63 and 64 are placed on the outer sides (concrete side) of the first and second members 62 and 62, and are fixed by tightening with bolts 65 and nuts 66 penetrated from the frame 61 side (the flexible joint 13 side). I have to do it.

Therefore, the arrangement of the frames 61 and 62 and the holding plates 63 and 64 is reversed from that of the flexible concrete pipe 10, and the holding plates 63 and 64 are attached to the front and rear pipe members 11 and 12.
64 comes into contact with the end face and is buried in the concrete.

Each of the holding plates 63 and 64 is formed in an annular shape having an inner and outer diameter that is between the concrete thicknesses of the flexible concrete pipe 60, and through holes for bolts 65 are formed at equal intervals around the circumference. The frames 61 and 62 disposed inside the holding plates 63 and 64 (on the side of the flexible joint 13) are made of a metal plate, and have an outer diameter smaller than that of the front and rear pipe members 11 and 12 in the protection cover 2.
7, the inner diameter of the front and rear pipe members 11, 1
2 is formed to be smaller than the inner diameter by the thickness of the elastic member 61. The protective cover 27 that covers the outer circumferences of the frames 61 and 62 and one frame 61 are spot-welded, and the other frame 62 is intermittently welded.

In such a flexible concrete pipe 60, the front and rear frames 61 and 62 are attached to the protective cover 27 by spot welding and intermittent welding, respectively. , 21, and pressing plates 63, 64 on the outside, and a through hole for fixing the front frame 61, and the front mounting portion 2 of the telescopic member 19.
No. 0 and the through-hole of the front holding plate 63 are aligned with each other, a mounting bolt 65 is inserted from the flexible joint 13 side of the front frame body 61, and tightened with a nut 66 from the concrete side of the front holding plate 62. Between the frame 61 and the front holding plate 63, the elastic member 19
And fix it by tightening the mounting part 20 of FIG.

By tightening the bolt 65 and the nut 66 at a plurality of circumferential positions in this manner, the elastic member 1
9 is completed on the front side.

Similarly, the rear side of the elastic member 19 is fixed by tightening the mounting portion 20 of the elastic member 19 between the rear frame body 62 and the rear holding plate 64 by the nut 66 previously screwed into the bolt 65. .

The tip of the bolt 65 tightened by the bolt 65 is buried in concrete and functions as an anchor.

Further, in the flexible concrete pipe 60, the annular water stopping member 6 is provided in the annular space with the protective cover 27 formed on the outer periphery of the mounting portions 20, 21 of the elastic member 61.
7 is filled in a compressed state.

The thus-assembled flexible joint 13 is set on a centrifugal molding form and integrated with concrete.

The other structure is the same as that of the flexible concrete pipe 10 already described, and the description is omitted.

The flexible concrete pipe 60 thus configured is interposed at regular intervals of a normal concrete pipe, buried underground, and used as a pipe or the like.

By using the flexible concrete pipe 60, when an external pressure such as earth pressure is applied between the front and rear pipe members 11 and 12, as shown in FIG.
9 can be prevented as much as possible by the ribs 23 for reinforcement, and the flexible joint 13 can be displaced and absorbed also by displacements such as elongation and contraction.

Thus, it is possible to prevent sewage waste from accumulating on the bottom portion of the flexible concrete pipe 60 or causing water rot due to a stagnant flow.

In this flexible concrete tube 60, the bolt 65 is passed through and the nut 66 is used to extend and contract the elastic member 19.
Is tightened, so that it is not necessary to perform a screwing process only by drilling a through hole for the bolt 65 in the frame bodies 61, 62 and the holding plates 63, 64. Assembly is also simpler than when stud bolts are used.

Next, still another embodiment of the present invention will be described in detail with reference to the drawings. FIG. 8 is an enlarged sectional view of a flexible joint portion according to still another embodiment of the flexible concrete pipe of the present invention, wherein FIG. 8A shows an assembled state, and FIG. Each shows a state of bending due to pressure.

The flexible concrete pipe 70 is obtained by changing the shape of the elastic member 19 constituting the flexible joint 13 of the flexible concrete pipe 10 described above. While increasing the displacement of
The amount of bending of the elastic member 71 with respect to the external pressure is minimized.

Therefore, here, only the configuration different from the already described flexible concrete pipe 10 will be described, and the same portions will be denoted by the same reference numerals and description thereof will be omitted.

In the flexible concrete pipe 70, the connecting portion 74 connecting the mounting portions 72 and 73 is elongated so that the length of the elastic member 71 constituting the flexible joint portion 13 in the axial direction is increased. In the connecting portion 74, two annular reinforcing ribs 75 and 76 are formed integrally at substantially equal intervals at an intermediate portion.

The other structure such as the fixing of the elastic member 71 having the two reinforcing ribs 75 and 76 at the intermediate portion of the connecting portion 74 is the same as that of the flexible concrete pipe 10 already described.

For example, the flexible concrete pipe 70
When an external pressure such as earth pressure is applied from the outer periphery of the protective cover 27, as shown in FIG. 8B, an external force is received by the rigidity of the protective cover 27 provided on the outer periphery of the flexible joint 13. However, when a large external pressure is applied, the protective cover 27 bends inward, and accordingly, an external pressure is also applied to the connecting portion 74 of the elastic member 71 via the joint material 41. Since the annular reinforcing ribs 75 and 76 are formed on the connecting portion 74, deformation (bending) of the connecting portion 74 toward the inner peripheral side is caused between the mounting portion 72 and the rib 75, and the ribs 75 and 76
Between the ribs 76 and the mounting portions 73, and the amount of bending can be reduced even if the connecting portions 74 are lengthened,
A large displacement can be absorbed and, at the same time, bending can be suppressed.

Therefore, this flexible concrete pipe 7
Even with 0, it is possible to prevent the accumulation of water contaminants on the bottom portion due to bending and the water rot due to the stagnant flow.

Next, another embodiment of the present invention will be described in detail with reference to the drawings. FIG. 9 is an enlarged sectional view of a flexible joint according to another embodiment of the flexible concrete pipe of the present invention. FIG. 9 (a) shows an assembled state, and FIG. 9 (b) shows an external pressure. 3 shows the bending state due to

The flexible concrete pipe 80 is modified so that the reinforcement by the reinforcing ribs 23 of the elastic member 19 constituting the flexible joint 13 of the flexible concrete pipe 60 described above is further increased. It was done.

Therefore, here, only the configuration different from the already described flexible concrete pipe 60 will be described, and the same parts as those of the flexible concrete pipes 10 and 60 will be denoted by the same reference numerals and description thereof will be omitted.

In the flexible concrete pipe 80, one annular reinforcing rib 85 is provided at the connecting portion 84 connecting the mounting portions 82 and 83 at both ends of the elastic member 81 constituting the flexible joint portion 13. An annular recess 86 which is formed integrally and has an outer peripheral side opened at the center is formed.

A ring 87 of a metal or synthetic resin for improving the rigidity is fitted into the annular concave portion 86 of the reinforcing rib 85 and is bonded with an adhesive or a plurality of circumferential rings are provided by screws 88. Installed in places.

The other mounting portions 8 of the elastic member 81
2 and 83 are fixed by the flexible concrete pipe 6 already described.
0, and the other configuration is the same as the flexible concrete pipe 10.

For example, the flexible concrete pipe 80
When an external pressure such as earth pressure is applied from the outer periphery of the protective cover 27, an external force is received by the rigidity of the protective cover 27 provided on the outer periphery of the flexible joint 13 as shown in FIG. However, when a large external pressure is applied, the protective cover 27 bends inward, and accordingly, an external pressure is also applied to the connecting portion 84 of the elastic member 81 via the joint material 41. An annular reinforcing rib 85 is formed on the ring 85, and a ring 87 is attached to the annular concave portion 86. Therefore, the deformation (bending) of the connecting portion 84 toward the inner peripheral side improves the rigidity of the rib 85 and the ring 87. Is suppressed by.

Therefore, this flexible concrete pipe 8
Even with 0, it is possible to prevent the accumulation of water contaminants on the bottom portion due to bending and the water rot due to the stagnant flow.

Further, since the ring 87 is separately attached, the rigidity of the reinforcing rib 85 can be adjusted by the ring 87, and the rigidity is secured only by the rib 85 formed integrally with the elastic member 81 using the same material. The degree of freedom of design for absorbing the displacement amount of the elastic member 81 is increased as compared with the case of performing the operation.

Next, another embodiment of the present invention will be described in detail with reference to the drawings. FIG. 10 is an enlarged sectional view of a flexible joint according to another embodiment of the flexible concrete pipe of the present invention. FIG. 10 (a) shows an assembled state, and FIG. 10 (b) shows an external pressure. FIG. 3C shows a flexed state due to the bending.

The flexible concrete pipe 90 is mainly formed by changing the shape of the elastic member 19 constituting the flexible joint portion 13 of the flexible concrete pipe 10 already described, and is compressed and filled around the outer periphery of the elastic member 19. Are different from each other in that the joint material 41 is divided into two parts. Therefore, these different parts will be described, and the same parts as those of the flexible concrete pipe 10 described above will be denoted by the same reference numerals and described. Is omitted.

In the flexible concrete tube 90, the size of the front and rear holding plates 92 and 93 is changed as the shape of the expansion and contraction member 91 constituting the flexible joint 13 is changed.

A pair of front and rear holding plates 92 and 93 disposed between the front and rear frames 14 and 15 are made of a metal plate, and have an outer diameter which is the size of an intermediate portion between the inner and outer diameters of the front and rear pipe members 11 and 12. The inner diameter is formed substantially the same as the inner diameter of the front and rear pipe members 11 and 12.
The other configuration of the front and rear holding plates 92 and 93 is as follows.
Same as 18.

The flexible tubular expansion and contraction member 91 in which the mounting portions 94 and 95 at both ends are sandwiched between the front and rear pressing plates 92 and 93 and the front and rear frames 14 and 15 is constructed as follows. Have been.

The cylindrical elastic member 91 has front and rear annular convex portions 96 and 97 which are annular convex portions having a U-shaped cross section and open on the inner peripheral side at both end portions (front and rear portions). Are formed as mounting portions 94 and 95, and a cylindrical connecting portion 98 is integrally formed so as to connect the inner portions of the front and rear annular convex portions 96 and 97 so as to be concave on the inner peripheral side. The outer diameter of the front and rear annular convex portions 96 and 97 of the tubular elastic member 91 is set to the size obtained by adding the thickness of the elastic member 91 to the outer diameter of the front and rear holding plates 92 and 93. Inner peripheral ends of convex portions 96 and 97 and connecting portion 9
8 is formed so that the inner diameter of the front and rear pipe members 11 and 12 is substantially the same.

Further, a plurality of through holes for mounting are formed in the mounting portions 94 and 95 at both ends of the elastic member 91 in the same arrangement as the through holes 16 of the front and rear frames 14 and 15 in a circumferential shape.

An annular reinforcing rib 99 is formed on the middle outer peripheral side of the connecting portion 98 of the elastic member 91 so as to protrude integrally with the outer peripheral side.

The annular reinforcing rib 99 has a vertically long cross-sectional shape which is narrow in the axial direction of the flexible concrete pipe 90 and high in the radial direction, as described above. The outer periphery of the part 98 is prevented from bending against external pressure.

When assembling the flexible joint portion 13, the front annular convex portion 96 of the elastic member 91 is attached so as to cover the annular front pressing plate 92 from the outer peripheral side by utilizing its flexibility. The rear annular convex portion 97 is also attached so as to cover the annular rear pressing plate 93 from the outer peripheral side by utilizing its flexibility.

Then, the through hole 1 for fixing the front frame body 14 is formed.
6. The through hole of the mounting portion 94 on the front side of the elastic member 91 is aligned with the female screw portion 17a of the front holding plate 92, and the stud bolt 25, which is a mounting bolt, is inserted from the front frame 14 side. After being screwed into the female screw portion 17a and fixed, the nut 26 previously screwed into the stud bolt 25 is used.
The mounting portion 94 of the elastic member 91 is clamped between the front frame body 14 and the front pressing plate 92 to be fixed.

The fastening of the elastic member 91 on the front side is completed by tightening the plurality of circumferential portions with the stud bolts 25 and the nuts 26 in this manner.

Similarly, on the rear side of the elastic member 91, the nut 26 screwed into the stud bolt 25 in advance is used to mount the mounting portion 9 of the elastic member 91 between the rear frame 15 and the rear holding plate 93.
5 and fix it by tightening.

Further, in the flexible concrete pipe 90, two annular concave joint materials 43 and an outer peripheral joint are provided in an annular space between the elastic member 91 and the protective cover 27 formed on the outer peripheral portion of the connecting portion 98. The material 44 is filled in a compressed state.

The joint material 43 for concave portions arranged on the inner peripheral side is
The outer peripheries of the annular convex portions 96, 97 at both ends of the elastic member 91 which are filled so as to be substantially flush with the outer peripheral sides of the annular convex portions 96, 97 at both ends of the elastic member 91. Outer peripheral joint material 44 is provided on the outer peripheral side of the side and concave joint material 43.
Are compressed and filled, so that the annular space surrounded by the elastic member 91 and the protective cover 27 is filled with the joint material 43 for the concave portion and the joint material 44 for the outer periphery. Similar to the joint material 41, the joint material 43 for the concave portion and the joint material 44 for the outer periphery are made of, for example, sponge rubber having closed cells and small bubbles.

The joint members 43 and 44 serve to prevent earth and sand and water from entering from the outside and also to reinforce the elastic member 91. The joint members 43 and 44 are provided between the outer periphery of the connecting portion 98 of the elastic member 91 and the front and rear pressing plate 92. , 93 are attached by bonding with an adhesive 42, and the like is the same as the joint material 41 described above.

The other structure is the same as that of the flexible concrete pipe 10 already described.

The flexible concrete pipe 90 thus constructed is interposed at regular intervals of a normal concrete pipe, buried underground, and used as a pipe or the like.

By using the flexible concrete pipe 90, the bending of the connecting portion 98 of the expansion and contraction member 91 when an external force such as earth pressure is applied between the front and rear pipe members 11 and 12 is reduced by the reinforcing rib 99. While it can be prevented as much as possible,
The flexible joint 13 can also be displaced and absorbed by displacement such as shrinkage.

For example, when an external pressure such as earth pressure is applied from the outer periphery of the protective cover 27, the rigidity of the protective cover 27 provided on the outer periphery of the flexible joint 13 as shown in FIG. External pressure is received, but the protective cover 27 bends inward against a large external pressure, and accordingly the external pressure is also applied to the connecting portion 98 of the elastic member 91 via the joint members 43 and 44.

Even if such an external pressure is applied to the connecting portion 98 of the elastic member 91, an annular reinforcing rib 99 is formed integrally on the outer peripheral side of the connecting portion 98 and has a longitudinally long cross-sectional shape. The ribs 99 can minimize the deformation (bending) of the portion 98 toward the inner peripheral side.

As a result, it is possible to prevent sewage waste from accumulating on the bottom portion of the flexible concrete pipe 90 or causing water rot due to a stagnant flow.

On the other hand, in the case of FIG. 10C showing a case where a large displacement occurs due to elongation between the front and rear pipe members 11 and 12,
The outer mounting portions 94 and 95 of the annular convex portions 96 and 97 at both ends of the elastic member 91 are sandwiched between the front and rear frames 14, 15 and the front and rear pressing plates 92 and 93, and are firmly fixed. The annular convex portions 96 and 97 separate from the front and rear holding plates 92 and 93 to shrink the joint material 43, and also deform the connecting portion 98 so as to extend, thereby preventing water from entering from outside and water leakage from inside.

Further, for an external pressure such as an earth pressure, depending on the magnitude of the external pressure, one of the joints between the protective cover 27 and the front and rear frames 14, 15 is spot-welded to the weaker one.
8 is broken and received by the protective cover 27 in a state of covering the outer periphery of the flexible joint portion 13.

Further, when a large displacement occurs due to shrinkage between the front and rear pipe members 11 and 12, although not shown, the joint members 43 and 44 are shrunk and the connecting portion 98 is also deformed so as to shrink. Prevent inundation and leakage from inside.

In the flexible concrete pipe 90, since the joint material is constituted by the joint material 43 for the concave portion and the joint material 44 for the outer periphery, the properties thereof can be changed. The Young's modulus is preferably high from the viewpoint of reinforcement against external water pressure, and low is preferable in order not to hinder the contraction displacement of the flexible joint portion 13. Therefore, the outer peripheral joint where the external water pressure directly acts on the outer peripheral side. It is possible to increase the Young's modulus of the member 44 and reduce the Young's modulus of the joint material 43 for concave portions, which affects the shrinkage displacement.

As described above, according to the flexible concrete pipe 90, the flexible concrete pipe 10 described above is used.
In addition to providing the same effect as described above, even if a large displacement due to elongation occurs between the front and rear pipe members 11 and 12, the annular convex portions 96 and 97 of the elastic member 91 are deformed so as to separate from the front and rear pressing plates 92 and 93. The displacement amount can be increased, and the allowable range of the elongation displacement that can be absorbed can be increased.

The front and rear frames, the front and rear holding plates, and the protective cover are not limited to being made of metal, but may be made of a synthetic resin such as FRP. The material may be selected according to the required strength. Good. For continuous joining, intermittent joining, and point joining between the front and rear frames and the protective cover, welding, an adhesive, or another joining method may be applied.

The front and rear frames, front and rear holding plates, protective covers and the like made of metal are subjected to a coating process before being attached to the formwork, for example, a tar epoxy resin coating. The contact surface can be unpainted.

Furthermore, each of these embodiments can be applied independently to a flexible concrete pipe, and can be combined to form a flexible concrete pipe.

[0140]

【Example】

(Example 1) A flexible concrete pipe similar to that described with reference to FIG. 1 is manufactured as described below, and a large displacement is absorbed without causing any damage by performing a bending test, a bending test, and the like of the elastic member against external pressure. And it was confirmed that the bending of the elastic member could be suppressed as much as possible.

The front and rear frames were arranged at an interval of 140 mm in the middle of a fume tube having a nominal diameter of 1000 mm (inner diameter of 1000 mm), and the front and rear holding plates were arranged at an interval of 90 mm. Then, a chloroprene rubber having a height of 62 mm at both ends and a thickness of 10 mm with an interval of the connecting portion of about 110 mm and a thickness of 10 mm is made as an elastic member. The ribs were formed with the same dimensions as the mounting portions at both ends. Then, the mounting portion of this elastic member is attached to one side 20.
The stud bolts were used to secure the anchor portion, and the length of the anchor portion was set to 50 mm. Further, a joint material of foamed rubber was placed on the outer periphery of the elastic member, covered with a protective cover having a length of 540 mm in the axial direction, and joined to the front and rear frames by intermittent welding and spot welding.

In such a flexible concrete pipe, there is no problem such as damage to a displacement amount of 100 mm, an elongation amount of 50 mm, and a contraction amount of 50 mm. Almost no bending to the circumferential side occurred. (Example 2) A flexible concrete pipe similar to that described with reference to FIG. 7 is manufactured as described below, and a bending test or a bending test of the elastic member against external pressure is performed. It has been confirmed that the elastic member can be absorbed without any deformation and the bending of the elastic member can be suppressed as much as possible.

The front and rear holding plates were arranged at an interval of 140 mm in the middle of a fume tube having a nominal diameter of 400 mm (inner diameter of 400 mm), and the front and rear frames were arranged at an interval of 114 mm. Then, a chloroprene rubber having a height of 30 mm at both ends and an interval of about 130 mm and a thickness of 5 mm as a telescopic member is made as an elastic member. The rib was formed with a thickness of 7 mm and a height of 30 mm.

[0144] The mounting portion of the elastic member was fastened and fixed with eight bolts on one side, and the length of the anchor portion was about 50 mm. Furthermore, while compressively filling the outer periphery of the elastic member and the front and back holding plate with the joint material of the foamed rubber, the water stopping member is put on the outer periphery of the elastic member and the front and rear holding plate,
It was covered with a protective cover having an axial length of 340 mm, and joined to the front and rear frames by intermittent welding and spot welding.

In such a flexible concrete pipe, there is no trouble such as damage to a displacement amount of 100 mm, an elongation amount of 50 mm, and a shrinkage amount of 50 mm. Almost no bending to the circumferential side occurred.

[0146]

As described above in detail with the embodiments, according to the flexible concrete pipe of the first aspect of the present invention, opposing end faces of the front and rear pipe members made of concrete. A pair of holding plates are disposed in parallel between the frame members, and both ends of a cylindrical elastic member reinforced with integrally formed ribs protruding to the outer peripheral side of the intermediate annular connecting portion. The mounting part of the ring is fastened and fixed between the frame and the holding plate with mounting bolts embedded in the holding plate, and this mounting bolt is penetrated through the frame and embedded in concrete. Is covered with a protective cover, so that a large amount of displacement can be absorbed by the annular connecting portion of the elastic member while protecting the elastic member with the protective cover, and at the same time, the external pressure of the elastic member is enhanced by the annular reinforcing rib. To the inner circumference side It is possible to prevent the body.

Thus, it is possible to prevent sewage waste from accumulating on the bottom portion of the flexible concrete pipe or causing water rot due to a stagnant flow.

Further, according to the flexible concrete pipe according to the second aspect of the present invention, an annular pressing plate is applied to the opposed end faces of the front and rear pipe members made of concrete, and a pair of parallel pressing plates are arranged therebetween. A frame body is arranged, and both ends of a tubular elastic member reinforced by ribs integrally formed on the outer peripheral side of the intermediate annular connecting portion are sandwiched between the holding plate and the frame body,
Attach the mounting bolts from the outside of the frame body to tighten and fix the telescopic member, bury the tip of the mounting bolts in concrete as an anchor, and cover the outside of the frame body with a protective cover. Therefore, while protecting the elastic member with the protective cover, it is possible to absorb a large amount of displacement at the connecting portion of the elastic member, and at the same time, to prevent the elastic member from bending toward the inner peripheral side by the annular reinforcing rib. It is possible to easily assemble without the need to form screws on the holding plate and the frame.

Thus, it is possible to prevent sewage waste from accumulating on the bottom portion of the flexible concrete pipe or causing water rot due to stagnant flow.

Further, according to the flexible concrete pipe of the third aspect of the present invention, an annular frame is applied to the end faces of the concrete front pipe member and the rear pipe member which face each other, and a pair of parallel frame members are provided therebetween. A holding plate is arranged, and is covered from outside with annular convex portions at both ends of a tubular elastic member reinforced by ribs integrally formed on the outer peripheral side of an intermediate annular connecting portion, and embedded in the holding plate. As the expansion and contraction member was tightened and fixed between the frame with the mounting bolts, the mounting bolt was penetrated through the frame, embedded in concrete, and the outside of the frame was covered with a protective cover, While protecting the elastic member with the protective cover, the annular convex portion of the elastic member and the annular connecting portion can absorb a large amount of displacement, and at the same time, the elastic member is bent inward by the annular reinforcing rib. To prevent It can be.

Thus, the flexible concrete pipe can absorb a large displacement, and at the same time, can prevent the accumulation of sewage dirt on the bottom portion and the occurrence of water rot due to the stagnant flow.

Further, according to the flexible concrete pipe according to the fourth aspect of the present invention, since a plurality of reinforcing ribs are formed integrally with the elastic member, the rigidity of the connecting portion is further increased. It is possible to reduce the amount of bending between the ribs and between the mounting portion and the ribs, thereby reducing the amount of bending of the entire elastic member.

According to the flexible concrete pipe according to the fifth aspect of the present invention, the annular ring is applied to the reinforcing ribs of the expansion and contraction member, or the intermediate member is attached between the annular ribs. By making the ring made of metal or made of synthetic resin, the rigidity of the flexible rib can be increased, the bending of the connecting portion can be further reduced, and compared with the case of reinforcing only with the rib. The degree of freedom of design such as selection of materials and characteristics of the elastic member is increased.

Further, according to the flexible concrete pipe according to the sixth aspect of the present invention, since a plurality of axial slits are formed in the protective cover, it is possible to prevent the protective cover from being cut off due to earth pressure or the like without cutting the protective cover. The elastic member can be smoothly deformed against pressure to protect the elastic member.

According to the flexible concrete pipe of the present invention, one of the joints between the protective cover and the frame is intermittently welded and the other is spot welded. When a large axial force is applied to the wire, the spot weld is broken to mitigate the effect, and even when the weld is broken, the state where the elastic member is covered with the protective cover can be maintained.

Further, according to the flexible concrete pipe according to the eighth aspect of the present invention, the joint material is filled in the space between the outer peripheral side of the annular connecting portion of the elastic member and the protective cover. In cooperation with the protective cover, it is possible to more reliably prevent intrusion of earth and sand into the outer peripheral side of the annular connecting portion of the elastic member, and to further reduce the bending of the waterproof rubber due to the external water pressure passing through the protective cover. It can be reliably supported.

According to the flexible concrete pipe of the ninth aspect of the present invention, since the joint material is constituted by a plurality of joint materials having different characteristics, for example, the Young's modulus of compression is enhanced with respect to the external water pressure. From the point of view, the higher is better, and the lower is better so as not to hinder the contraction displacement of the elastic member, so the Young's modulus of the joint material in the part where the external water pressure directly acts on the outer peripheral side is increased, and It is possible to easily lower the Young's modulus of the joint material on the inner peripheral side, which has an influence.

Further, according to the flexible concrete pipe according to the tenth aspect of the present invention, since the water blocking member is provided between the frame and the end face of the concrete pipe member,
It is possible to improve the sealing property of this portion, and it is possible to more reliably prevent water leakage from the inside and water entry from the outside.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a flexible joint according to an embodiment of a flexible concrete pipe of the present invention.

FIG. 2 is a longitudinal sectional view of the flexible concrete pipe according to one embodiment of the present invention, in which only the upper half is cut.

FIG. 3 is an enlarged sectional view showing a state in which an external pressure such as an external water pressure is applied according to an embodiment of the flexible concrete pipe of the present invention.

FIG. 4 is an enlarged sectional view showing a state in which a large displacement due to elongation has occurred according to an embodiment of the flexible concrete pipe of the present invention.

FIG. 5 is an enlarged cross-sectional view showing a state in which a large displacement due to shrinkage has occurred according to an embodiment of the flexible concrete pipe of the present invention.

FIG. 6 is a perspective view showing a state in which a large displacement due to torsion has occurred according to the embodiment of the flexible concrete pipe of the present invention.

FIG. 7 is an enlarged sectional view of a flexible joint according to another embodiment of the flexible concrete pipe of the present invention, wherein FIG. 7 (a) shows an assembled state and FIG. Each shows a state of bending due to pressure.

FIG. 8 is an enlarged sectional view of a flexible joint portion according to still another embodiment of the flexible concrete pipe of the present invention, wherein FIG. 8 (a) shows an assembled state, and FIG. Each shows a state of bending due to external pressure.

FIG. 9 is an enlarged sectional view of a flexible joint according to another embodiment of the flexible concrete pipe of the present invention, wherein FIG. 9 (a) shows an assembled state, and FIG. Each shows a state of bending due to pressure.

FIG. 10 is an enlarged sectional view of a flexible joint according to another embodiment of the flexible concrete pipe of the present invention, wherein FIG. 10A shows an assembled state, and FIG. FIG. 3C shows a state of bending due to pressure, and FIG.

FIG. 11 is a vertical cross-sectional view of only the upper half of a conventional flexible concrete pipe.

FIG. 12 is a vertical cross-sectional view of only the upper half of another conventional flexible concrete pipe.

[Explanation of symbols]

 10, 60, 70, 80, 90 Flexible concrete pipe 11 Front pipe member 12 Rear pipe member 13 Flexible joint part 14, 61 Front frame 15, 62 Rear frame 17, 63, 92 Front pressing plate 18, 64,93 Back holding plate 19,71,81 Elastic member 20,72,82,94 Front mounting part 21,73,83,95 Rear mounting part 22,74,84,98 Connecting part 23,75,76,85, 99 Reinforcing Rib 25 Stud Bolt 26 Nut 27 Protective Cover 28 Intermittent Welding Part 29 Point Welding Part 31 Slit 41 Jointing Material 42 Adhesive 43 Jointing Material for Depression 44 Exterior Jointing Material 51 Waterproof Member 65 Bolt 66 Nut 86 Recessed 87 Ring 88 Screw 96 Front annular convex part 97 Rear annular convex part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-86238 (JP, A) JP 2-57176 (JP, B2) JP-B 62-23134 (JP, B2) JP-B 48-48 40124 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16L 9/19 F16L 27/10

Claims (10)

(57) [Claims] 1. A flexible concrete pipe provided with a flexible joint portion between a front and rear pipe member made of concrete, wherein the flexible concrete pipe hits a rear end face of the front pipe member and a front end face of the rear pipe member. An annular frame smaller in diameter than the front and rear pipe members, a pair of annular pressing plates provided in parallel between the two frames, and annular ends at both ends sandwiched between the frame and the pressing plate And an annular connecting portion at an intermediate portion along the inner peripheral surface of the front and rear pipe members by connecting the attaching portion and the annular attaching portion on the inner peripheral side, and protruding toward the intermediate outer peripheral side of the annular connecting portion. A tubular flexible elastic member provided with an annular reinforcing rib integrally formed, and a tubular member buried in the front and rear pipe members, penetrating through the annular mounting portion of the frame and the elastic member. A plurality of screws that are screwed into the holding plate to tighten the annular mounting portion of the elastic member And with the bolt, the flexible concrete pipe, wherein an annular protective cover along the outer peripheral surfaces of the front and rear tube member, to become in a provided between the front and rear tube member. 2. A flexible concrete pipe having a flexible joint between a front and a rear pipe member made of concrete, and abutting on a rear end face of the front pipe member and a front end face of the rear pipe member. An annular holding plate, a pair of annular frames provided in parallel between the two holding plates and having a diameter smaller than the front and rear pipe members, and annular attachments at both ends sandwiched between the holding plate and the frame. And an annular connecting portion of an intermediate portion along the inner peripheral surface of the front and rear pipe members by connecting the portion and the annular mounting portion on the inner peripheral side, and protruding toward the intermediate outer peripheral side of the annular connecting portion to be integrally formed. A tubular flexible extensible member having a formed annular reinforcing rib; the frame, the annular mounting portion of the extensible member and the presser plate; and the presser plate and the frame. With the body, tighten the annular mounting portion of the elastic member, and A plurality of mounting bolts having ends buried in the front and rear pipe members, and an annular protective cover provided between the front and rear pipe members and along the outer peripheral surface of the front and rear pipe members. Concrete pipe. 3. A flexible concrete pipe provided with a flexible joint portion between a front and rear pipe member made of concrete, and abutting on a rear end face of the front pipe member and a front end face of the rear pipe member. An annular frame, a pair of annular pressing plates provided in parallel between the two frames, and smaller in diameter than the front and rear pipe members, and annular convex portions at both end portions respectively covering the pair of pressing plates from the outer peripheral side. And an annular connecting portion that connects these annular convex portions along the inner peripheral surface of the front and rear pipe members, and is formed integrally with the annular connecting portion by protruding toward an intermediate outer peripheral side of the annular connecting portion. A tubular flexible telescopic member having ribs; and the telescopic member embedded in the front and rear pipe members, threaded through the frame body and the frame contact portion of the telescopic member, and screwed into the holding plate. Multiple mounting bolts to tighten the mounting part of Flexible concrete pipe, wherein the protective cover annular along the outer surfaces of the front and rear tube member, to become in provided between the front and rear tube member. 4. A plurality of annular reinforcing ribs formed on said flexible telescopic member.
4. The flexible concrete pipe according to any one of claims 1 to 3. 5. The flexible concrete pipe according to claim 1, wherein an annular ring for improving rigidity is attached to an annular reinforcing rib of the elastic member. 6. The flexible concrete pipe according to claim 1, wherein a plurality of slits are formed in the protective cover in parallel with the axial direction of the front and rear pipe members. 7. A joint portion between the protective cover and the pair of frame bodies is formed by intermittent welding with one of them and spot welding with one of the other.
7. The flexible concrete pipe according to any one of 6. 8. A flexible material according to claim 1, wherein a space between an outer peripheral side of an annular connecting portion of said elastic member and said protective cover is filled with a joint material. Concrete pipe. 9. The flexible concrete pipe according to claim 8, wherein said joint material is made of a plurality of joint materials having different characteristics. 10. The flexible concrete according to claim 1, wherein an annular water-stopping member is provided at a contact portion between the frame and the end faces of the front and rear pipe members. tube.