JPH0245593Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention mainly relates to a pipe packing material used to stop water at the connection part of underground pipes such as sewage pipes.

Conventionally, rubber rings have been used to shut off water at the joints of underground pipes, and the joints at the joints are closed by the rebound elasticity when the joints are compressed.
However, with this method of stopping water simply by using rebound resilience, the external load from the road surface becomes severe due to the increase in traffic on the road surface, and the problem occurs when the pipe is buried under poor conditions. Water leakage accidents often occur at connections due to external force loads or strain external forces caused by ground movements during earthquakes. Also, when concrete products such as Huyume pipes are used for piping, the unique surface of concrete There was a problem that water leakage easily occurred due to the roughness.

The present invention was devised to solve the above-mentioned problems.In other words, the purpose of the present invention is to maintain a constant connection even under poor installation conditions, harsh buried environments, and regardless of the type of pipe material. To provide a packing material for pipes which can reliably watertight a part.

As a means to achieve this purpose, the pipe packing material of the present invention is designed to
In the annular or band-shaped packing material 1 fitted between the inner circumferential surface and the outer circumferential surface of the connection part of the other pipe 4, the outer circumferential surface and the inner circumferential surface are made of a non-water-swellable rubber material made of rubber. A main body part 6 in which grooves 6e and 6d are formed, and a water-swellable rubber material made of synthetic rubber and super absorbent resin that is filled and fixed in the inner and outer grooves 6d and 6e of the main body part 6, respectively. inner and outer surface coatings 7, 8;
It is characterized in that it is fixed by integral vulcanization with the main body part 6 while embedded in the parts d and 6e.

Hereinafter, the present invention will be explained based on an illustrated embodiment.

As shown in FIGS. 1 to 3, the packing material 1 of the embodiment is used to attach sockets 3 of one pipe 2 of underground pipes made of concrete pipes connected to each other.
The packing material 1 has a band shape that is fitted in a ring shape between the inner circumferential surface and the outer circumferential surface of the spigot 5 of the other pipe 4. , molded from non-water-swellable rubber material.

Therefore, the cross-sectional shape of the packing material 1 has a flat inner circumferential surface and an uneven outer circumferential surface with overhangs and cutouts formed on both sides, that is, one end of the outer circumferential surface closer to the piping 2. The part forms a cut-off slope 6a, and the end near the other pipe 4 has a bulging fin-like protrusion 6b, and the flesh part near the slope 6a has a compression allowance of the packing material 1. A hollow annular hole 6c is bored for increasing the size. Note that the cut-off slope 6a may be formed into a convex curved surface as the case may be.

Further, in the intermediate portions of the inner and outer circumferential surfaces of the packing material 1 in the axial direction, the main body portion 6 is formed thinly, and inner and outer grooves 6d and 6e are formed on both circumferential surfaces, and the respective grooves 6d , 6e are embedded with an inner surface covering layer 7 and an outer surface covering layer 8 molded from water-expandable rubber made of synthetic rubber and super absorbent resin, and are firmly bonded to the main body portion 6 by integral molding and vulcanization. is glued to.

The synthetic rubber constituting the main body portion 6 may be chloroprene rubber, styrene-butadiene (or isoprene)-styrene copolymer, etc.
Contains ~50% crystalline or glassy regions
1.3 Diene rubber is preferable in terms of water absorption, and as the highly water-absorbent resin, a resin that absorbs 20 to 1000 times its own weight of water, which is a crosslinked and insolubilized water-soluble resin, is preferable.

Packing material 1 of the embodiment configured in this way
If one and the other piping 2, 4 are connected by interposing a
The joint is sealed by the water absorption and expansion phenomenon described in No. 8, and at that time, the following direct and indirect effects are obtained.

(a) Since the joint closing action is performed synergistically by the repulsive elasticity of the main body portion 6 and the expansion force of both covering layers 7 and 8, changes in the joint gap due to ground movement etc. can be effectively followed. It maintains sealing performance, and also follows the roughness of the surface of the pipe body to ensure sealing performance.

(b) Since the main body portion 6 and the covering layers 7, 8 are integrally vulcanized, the expansion of the covering layers 7, 8 in the axial direction is strongly suppressed, increasing watertightness, and also preventing immersion in water. There is no risk that the coatings 7 and 8 will peel off when the coating is removed.

(c) Since the covering layers 7 and 8 are in surface contact with the circumferential surfaces of the socket 3 and the spigot 5, watertightness is good.

(d) When connecting both pipes 2 and 4, use spigot 5.
The pipe 4 on the other side is pulled into the pipe 2 on the socket 3 side, and the connection workability is good as described below.

(a) In order to maintain good watertightness due to the water-swellability of the covering layers 7 and 8, the compressibility and axial length of the packing material 1 can be kept to the minimum necessary for centering and initial water stoppage. As a result, pull-in joining is easy and there is no risk of socket cracking.

(b) Since the compression margin is increased by the protrusion 6b and the annular hole 6c of the main body portion 6, the compression repulsion force required for initial water stoppage and centering is reduced, and as a result, the same advantages as in the previous section are obtained.

(c) Since the protrusion 6b that performs the initial water stop function is a single thread, lubricant can be easily applied to its surface, resulting in high lubrication efficiency.

The packing material of the example can also be widely applied to the connection of hume pipes having the above-mentioned B-shaped sockets and propulsion hume pipes using steel plate collars. The packing material is fitted between the inner circumferential surface of the tube and the outer circumferential surface of the hume tube.

As described above, according to the packing material for pipes according to the present invention, the main body portion of the packing material that is fitted between the inner circumferential surface and the outer circumferential surface of the pipe connecting portion is molded from a non-water-expandable material. Since a coating made of water-expandable material is formed at the intermediate portion of the inner and outer circumferential surfaces, the ability to follow the gaps between the joints of the buried pipe connection area is improved, and this makes it possible to avoid poor installation conditions. Regardless of the type of pipe material or harsh buried environment, the connection part can always be easily and reliably sealed.

In addition, according to the present invention, if water leaks due to the unevenness of the corrugated hump pipe wall surface of the packing material not only on the outer peripheral surface side but also on the inner peripheral surface side of the connecting part of the piping, it is possible to prevent water expansion. By expanding the inner surface coating 7, it is possible to stop water leakage from the inner peripheral surface side as well as from the outer peripheral surface side.

In addition, if a water-expandable outer surface coating is provided only on the outer peripheral surface of the main body, the outer surface of the packing material expands due to water leakage, deforming the packing material into a meandering shape, and causing the inner peripheral surface of the packing material to expand. A gap may be created between the pipe and the outer circumferential surface of the pipe, causing water leakage, but in the present invention, the inner surface coating 7 and the outer surface coating 8 made of a water-expandable material expand evenly. There is no partial deformation of the packing material, and water can be effectively stopped.

Furthermore, the packing material of the present invention has inner and outer covering layers 7 and 8 formed of a water-swellable rubber material made of synthetic rubber and a superabsorbent resin. Grooves 6d, 6e
Since the two are fixed by integral vulcanization while embedded in the inner wall, the structure is solid and the above-mentioned fixation is strong, and there is no possibility of peeling off when water expands, tearing, cracking, etc.

[Brief explanation of the drawing]

Fig. 1 is a side view of a pipe packing material according to an embodiment of the present invention in an installed state, Fig. 2 is a partial side sectional view of the packing material in the part shown in Fig. It is a sectional view showing a free state of the material. 1... Packing material, 2, 4... One and the other piping, 6... Main body portion, 7, 8... Covering layer.

Claims (1)

[Claims for Utility Model Registration] One pipe 2 and the other pipe 4 connected to each other
In the annular or band-shaped packing material 1 fitted between the inner circumferential surface and the outer circumferential surface of the connecting portion of inner and outer surface coatings 7 and 8 made of a water-swellable rubber material made of synthetic rubber and super absorbent resin, which are filled and fixed in the inner and outer grooves 6d and 6e of the main body portion 6, respectively; The covering layers 7 and 8 are formed by the concave groove 6 of the main body portion 6.
A pipe packing material characterized in that it is fixed by integral vulcanization with the main body part 6 while embedded in the pipes d and 6e.