JPS6232682B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a water stopper for a conduit through which three cables are inserted. More specifically, the present invention relates to a three-part pipe water stopper that utilizes the force generated by the volumetric expansion of a water-swellable member when it swells with water. [Conventional technology] In conduits for underground cables for transmission and reception of electric power, power distribution, telegraph and telephone lines, it is necessary to prevent underground water seepage from the conduits into manholes, power distribution rooms, etc. . In addition, when repairing rainwater or underground water drainage pipes, or constructing halls or manholes, the pipes must be temporarily sealed. One way to stop the water in such pipes is to seal the pipes with putty. However, in this method, the putty is sticky, making it difficult to handle, and the putty deteriorates over time, resulting in water leakage when used for a long period of time. In order to overcome these shortcomings of putty, a method has been proposed in which the pipes are sealed with a water stopper. Water stoppers include (1) a type in which an elastic body is sandwiched between two flanges, and the flanges are tightened with bolts to compress and deform the elastic body to seal the pipe (Utility Model No. 55-35886);
No. Publication, (2) An annular rubber body having a brim-shaped portion is arranged so that the jaw-shaped portion is in contact with the inner wall surface of the pipe, and a putty-like compound or a foam sealant is applied to the space formed by the annular rubber body and the inner wall surface of the pipe. Filling type (Mitsukaiaki
55-24019 and Utility Model Application Publication No. 55-100432), (3) A plug is made of a rubber elastic body or a material in which a water-swellable resin is mixed with a synthetic resin, and the plug is fitted into a pipe. (4) a type in which a waterproof compound mixed with water-absorbing resin is sandwiched between packings and fixed by pressure contact with bolts (Japanese Utility Model Publication No. 189225/1983), and (5) packings with a flange only on the cable side. Type that presses clay-like mixture (Jikko Sho 43-
29896). Also, it is used as a water stopper for pipes with three cables inserted.
No. 57-189225 discloses a packing divided into two parts. [Problems to be solved by the invention] However, the water stopper of the type (1) in which the elastic body is compressed and deformed cannot obtain the desired water stop pressure unless a large elastic body is used, making it heavy. Another disadvantage is that flanges and bolts that can withstand the large repulsive force of the elastic body must be used, and it is difficult to seal the complicated and small gaps. In addition, the water stopper of type (2), in which a putty-like compound or foam sealant is filled into an annular rubber body, is sticky and fluid, making it difficult to handle and difficult to inject. It requires special equipment and techniques, and has the drawback of not being able to adequately deal with minute gaps and irregularities on the inner wall surface of the pipe.
Furthermore, in the type (3) type of water stopper that uses a plug made of a material in which water-swellable resin is mixed with a rubber elastic body, the water-swellable resin is mixed to give the plug a certain degree of strength. As a result, the rate of increase in volume due to water swelling is slow, and the water stoppage at the initial stage of sealing is insufficient, requiring a fairly long period of time to achieve complete waterstopping power. Similar to type (2), it is difficult to stop water between complex and minute gaps, and the processing cost is also high. In addition, in the case of type 4, the water stopping power is mainly obtained from the pressure contact force of the waterproof compound by pressing with packing. The expansion power of the absorbent resin in the waterproof compound can only be obtained on the surface that comes into contact with water, that is, the peripheral surface.
The ability of water-absorbing resin cannot be fully utilized. Furthermore, the problem of leakage of the waterproofing compound arises. (Five)
Similar to type (2), type (2) also has problems with long-term water-stopping because the pressure force generated by pressing the clay-like mixture gradually decreases. In addition, in the two-part water stop device disclosed in Utility Model Application Publication No. 57-189225 for three cable pipes, water is stopped by filling the space surrounded by three cables with only waterproof compound. However, there is no way to stop the waterproofing compound from leaking in that area, and there is no hope of completely stopping the water for a long period of time. The inventors of the present invention have conducted intensive research to solve the above-mentioned drawbacks, and as a result, they have used a water-swellable material as a pressure generation source, and arranged the water-swellable resin with a space between them so that it can be easily absorbed. When the seal with the inner wall of the pipe is made with a lip made of garbage that is pressed against the inner wall of the pipe by the pressure, it is possible to completely stop water in a short time and to obtain the necessary pressure for a long period of time.
Furthermore, we discovered that the elastic deformation of the lip allows it to respond to minute changes in the wall surface.Furthermore, when the water stop device is divided into three fan-shaped blocks, the water stop in the area surrounded by the three cables is complete. The present invention was completed based on the discovery that the installation work becomes extremely easy. [Means for Solving the Problems] That is, the present invention is a water stopper for a conduit through which three cables are inserted, and includes a pair of rubber expansion members and a pair of rubber expansion members for fixing them. It is composed of a flange and a fixing means consisting of three sets of bolts and nuts, and each expansion member and flange is divided into three equal parts into three fan-shaped blocks, and each fan-shaped expansion member block has (a) It has approximately semicircular recesses on two sides that are larger than the thickness of the cable,
and (b) has a bolt insertion hole near the center, and
(c) It has continuous, pointed, elastically deformable lips on the outer edge of one surface and the periphery of the bolt insertion hole, and each pair of fan-shaped expansion member blocks has opposing lips. As shown in FIG. This article relates to a pipe water stopper. [Operation and Examples] The water stopper of the present invention is intended for stopping water in a conduit through which three cables are inserted, and the conduit is divided into three fan-shaped blocks. It can be easily installed by using a water stopper, and it can be completely maintained over a long period of time by compressing the pointed and elastically deformable lip using the expansion force of the water-swellable material. It is characterized by its ability to stop water. The expansion member block is a sector-shaped elastic plate-like member, such as rubber, having an outer diameter slightly smaller than the inner diameter of the tube, and has a continuous lip on the outer edge of one side thereof. The lip is integrally formed with the plate-like portion, and has a pointed tip and is highly elastically deformable. Preferably, the inner surface of the lip has an angle with respect to the plate. The inner surface of the lip may be flat or curved. Further, the size of the lip may be selected as appropriate depending on the material of the lip and the location to which it is applied, as long as it can exert a sufficient pressure contact force on the inner wall surface of the pipe and be in close contact with the inner wall surface of the pipe. In the present invention, such a pair of expansion members is used to arrange the lips so as to face each other and to fix them relatively. A combination of flanges and bolts/nuts can be used for this fixing. When using flanges and bolts/nuts, the flange may be brought into contact with the surface of each expansion member on which the lip is not provided, and the bolts may be inserted through the flange and the pair of expansion members and fixed with nuts. In this case, it is not necessary to compress both expansion members, and it is preferable not to compress them. This is because the purpose of the relative fixation of the expansion members in the present invention is to maintain a constant distance between the expansion members, and not to compress them. The water-swellable resin is placed in at least a portion of the space formed between the pair of expansion members. As the water-swellable resin, a superabsorbent resin or a mixture of a superabsorbent resin and another synthetic resin is used. Super absorbent resin absorbs and retains about 500 times its own weight of water, and expands greatly as it absorbs water. Examples of superabsorbent resins include starch-based superabsorbent resins obtained by graft copolymerizing starch with acrylonitrile, acrylic acid, styrene sulfonic acid, vinyl sulfonic acid, etc., cellulose-acrylonitrile graft copolymers, and cellulose-styrene sulfonic acid graft copolymers. Polymers, cellulose-based super-absorbent resins such as cross-linked carboxymethyl cellulose, cross-linked polyvinyl alcohol, polyvinyl alcohol-based super-absorbent resins such as acrylic-vinyl acetate saponified products, polyacrylate cross-linked products, polyacrylonitrile polymers and acrylic superabsorbent resins such as saponified products of and cross-linked polyethylene glycol diacrylate. When using super absorbent resin alone,
It is preferable to use a fibrous material. The water-swellable member is placed between the expansion members when they are fixed, but it may be filled in advance into a recess surrounded by the lip and plate-like portion of at least one, preferably both expansion members. Alternatively, it may be formed in advance into a rectangular cross-sectional shape. In that case, since the superabsorbent resin alone does not have good moldability, a material mixed with other resins may be used. Preferred examples of other resins to be mixed include synthetic resins such as ethylene-vinyl acetate copolymer and polyurethane, and natural rubber. The amount of other resins must be suppressed to an extent that does not significantly impair the volumetric swelling ability of the superabsorbent resin, for example, such that the volumetric swelling ratio of the water-swellable member is about twice or more. The blending ratio is 10 to 300 parts, preferably 100 to 250 parts, of super absorbent resin to 100 parts (parts by weight, the same applies below) of other resins.
Department. The amount of the water-swellable member must be such that it still has water-absorbing capacity even when it absorbs water and expands to completely fill the space formed between the two expandable members. The preferred amount varies depending on the maximum expansion ratio of the water-swellable resin, but when the volume when expanded to the maximum is about 2 times or more, preferably 3 to 30 times, the space between the expansion members, the lip can be used on the inner wall surface of the pipe, etc. This creates enough pressure to press the The water stop mechanism in the water stop device of the present invention is as follows. First, when water enters the space between the pair of expansion members, the water-swellable member absorbs the water and expands. This expansion continues until the space is filled and the lip is pressed against the inner wall of the cable pipe. All the water that enters during this period is absorbed by the water-swellable member, so no water leakage occurs. Even at maximum expansion, water-swellable materials still have significant water absorption capacity (volume expansion capacity)
have. Therefore, even if the water pressure increases and water intrudes, the water-swellable member absorbs it and the expansion pressure further increases, so that no water leaks. The water stopper of the present invention can sufficiently withstand water pressure of about 5 kg/cm ² and does not cause initial water leakage. In order to make the expansion of the water-swellable members uniform, a porous body such as a sponge may be placed between two facing water-swellable members. By arranging such a porous body, the infiltrated water is almost uniformly absorbed into the water-swellable member, resulting in uniform expansion of the water-swellable member. Further, by arranging the porous body, it is possible to maintain a predetermined distance between the expansion members during installation. Next, embodiments of the water stopper of the present invention will be described based on the drawings, but the present invention is not limited to these embodiments. FIG. 1 is a schematic front view of a water stopper of the present invention attached to a cable pipe 1 through which three cables 2 are inserted. The water stopper of the present invention is divided into fan-shaped blocks obtained by dividing a circle into three equal parts, and by combining these blocks, one water stopper is completed. FIG. 2 shows a schematic exploded perspective view of one fan-shaped block. The fan-shaped block consists of a pair of flange blocks 6a, 7a and fan-shaped expansion member blocks 3a, 4a sandwiched between them, which are relatively fixed with bolts 8 and nuts 9. The expansion member blocks 3a, 4a each have sharp, elastically deformable lips 5a, 5b on their peripheries, and the water-swellable member 10 is disposed inside the lips 5a, 5b. Furthermore, a substantially semicircular recess 14 larger than the thickness of the cable is provided on each of the two sides of the sector, and an insertion hole 15 for the bolt 8 is also provided. Lips 5 are also provided on the peripheries of these irregularly shaped parts. When three such fan-shaped blocks are installed in the cable pipe 1 along the three cables 2, the shape shown in FIG. 1 is obtained. FIG. 3 shows a sectional view taken along the line X--X in FIG. 1. 1 is an underground cable pipe, through which a cable 2 is passed. Expansion member block 3a,
3c, 4a, 4c have lips 5a, 5b on their outer edges, respectively. The expansion member block is sandwiched between flange blocks 6a, 6c, 7a, and 7c, and is relatively spaced apart by bolts 8 and nuts 9.
It is fixed with 2 spaces apart. The recesses surrounded by the lips 5a, 5b of the expandable member block are each filled with a water-swellable member 10. A small space is left between the expansion member block, the flange block, the inner wall surface 11 of the cable pipe 1, and the surface of the cable 2 so that a water stopper can be easily inserted. FIG. 4 shows a schematic longitudinal sectional view of the embodiment shown in FIG. 3 when water is stopped. When water 13 enters the space 12 (FIG. 3) formed between the expansion members, the water-swellable member 10 rapidly expands and fills the space 12, causing the expansion member block and its lips 5a, 5 to expand.
Apply pressure to b. However, the expansion member is bolt 8.
Since they are relatively fixed by the nuts 9 and 9, they do not move, and only the lips 5a and 5b are pushed outward and are pressed against the inner wall surface 11 of the cable pipe 1, the bolt 8, and the surface of the cable 2, creating a complete seal. achieved. Since the lip is made of an elastic material like the main body of the expansion member, it is highly elastically deformable, and therefore can sufficiently cope with some irregularities on the inner wall surface 11 of the tube, and can provide a sufficient seal. FIG. 5 is a schematic perspective view of the expansion member block used in the embodiment shown in FIG. A schematic cross-sectional view is shown. As shown in FIG. 5, the lip 5a is provided over the entire outer edge of the expansion member block 3a, including the outer edge of the recess 14 and the immediate bolt passage hole 15. By providing the lip 5a in this way, it is possible to completely seal with all the members in contact with it. Although the lip can be made in various shapes, it is preferable to use a lip that can effectively utilize the pressure generated by the expansion of the water-swellable member and that can adhere tightly to the inner wall surface of the tube. For example, as shown in FIG. 3, the inner surface may be an inclined surface and the entire surface may be protruded outward, or only the inner surface may be an inclined surface as shown in FIG. 6A. Further, the inner surface may be a curved surface as shown in FIG. 6B. Furthermore, as shown in FIG. 7, the expansion member itself may be formed by cutting into a V-shape. It is preferable that the tip of the lip be pointed in view of effective use of pressure and elastic deformability. Each fan-shaped block of the water stopper assembled according to the procedure shown in FIG. 2 is placed along the cable 2 at a predetermined position within the cable pipe 1 while remaining relatively fixed. Further, as shown in FIG. 8, a porous body 16 such as a sponge may be inserted between the water-swellable members 10 so that the water that has entered the water-swellable member can be distributed. Further, by arranging the porous body, the shape can be easily maintained during installation. In this way, the water stopper of the present invention can be extremely easily installed by anyone into a conduit through which a cable has already been inserted, no special equipment is required, and it can be easily removed by simply loosening the nut. can. Next, the volume expansion performance of various water-swellable members used in the present invention was investigated. First, a mixture of Sumikagel S-33 (trade name of super absorbent resin manufactured by Sumitomo Chemical Co., Ltd.) and Sumitate (trade name of ethylene-vinyl acetate copolymer manufactured by Sumitomo Chemical Co., Ltd.) is kneaded. A paste was used as a water-swellable member. Volumetric expansion times of water-swellable parts at maximum water absorption when the mixing ratio of Sumikagel S-33 and Sumitate is changed

[Table] As shown in Table 1 and FIG. 9, all of the water-swellable members have a sufficient volumetric expansion ratio. In addition, sample 3 was formed into a 1 cm square dice shape, and this was placed in a water tank and pressure was applied to measure the pressure that would prevent the sample from expanding. The results are shown in FIG. From FIG. 10, it can be seen that the inflation pressure generated exhibits an upwardly convex curve, allowing the seal to produce the necessary lip expansion pressure. Table 2 shows the maximum volume expansion ratio of mixtures of various super absorbent resins and other resins.

[Table] As is clear from Table 2, the necessary volumetric expansion ratio can be obtained even in mixtures of various super absorbent resins and other resins. Next, the first step is to stop the water in the cable pipe with an inner diameter of 132.5 mmφ through which three cables with an outer diameter of 32.5 mmφ are inserted.
The test was carried out using the water stopper of the present invention shown in the figure. The water stopper used had an outer diameter of 132 mmφ when assembled, and a cable insertion hole diameter of 32 mmφ. As the expansion member, a three-part member made of natural rubber was used, and a flange made of polyvinyl chloride was used. As the water-swellable member, 50 g of the sample 3 (mixture of Sumitate (100 parts) and Sumikagel S-33 (250 parts): maximum volumetric expansion magnification of approximately 30 times) was used, and the distance between the expansion members was set to 3 mm. . At this time, the space volume formed between the expansion members was 91 cm ³ , and the volume occupied by the water-swellable member was 50 cm ³ . The water stopper of the present invention constructed in this way was attached to the cable pipe, water was poured into the cable pipe from one side, and a pressure of 0.5 kg/cm ² was applied for 10 minutes, but no water leakage occurred during that time. It didn't happen right away. Then, increase the water pressure to 0.6Kg/cm ² and maintain it for 50 minutes, and then
It was maintained at 1.0Kg/cm ² for 23 hours and at 2.0Kg/cm ² for 120 hours, but no water leakage occurred in either case.
Furthermore, even when a water pressure of 5 kg/cm ² was applied, no water leakage occurred.

[Brief explanation of the drawing]

Figure 1 is a schematic front view of one embodiment of the water stopper of the present invention when it is attached to a cable pipe (before water is stopped);
The figure is a schematic exploded perspective view of the fan-shaped block of the water stopper of the present invention, FIG. 3 is a sectional view taken along the line X-X of FIG. 1, and FIG. 4 is a schematic diagram of the water stopper shown in FIG. 5 is a schematic perspective view of an expansion member block used in the present invention, FIGS. 6A and 6B are schematic sectional views of lips of different shapes, and FIG. 7 is a schematic sectional view of another embodiment of the expansion member block. Fig. 8 is a schematic sectional view of still another embodiment of the water stopper of the present invention, and Fig. 9 shows the relationship between the volumetric expansion ratio and water immersion time of various water-swellable members used in the present invention. The graph shown in FIG. 10 is a graph showing the change over time in the expansion pressure of the water-swellable member used in the present invention. (Main symbols in the drawing), 1: Cable pipe, 2: Cable, 3a, 3b, 3c, 4a, 4b, 4c:
Fan-shaped expansion member block, 5, 5a, 5b: lip, 6, 7: flange, 6a, 6b, 6c, 7
a, 7b, 7c: fan-shaped flange block, 8: bolt, 9: nut, 10: water-swellable member, 11:
Inner wall surface of cable pipe, 12: Space, 13: Water, 1
4: recess, 15: bolt insertion hole, 16: porous body.

Claims (1)

[Claims] 1. A water stopper for a conduit through which three cables are inserted, which includes a pair of rubber expansion members, a pair of flanges for fixing them, and three sets of bolts and nuts. each of the expansion members and the flange is divided into three equal parts into three fan-shaped blocks, and each fan-shaped expansion member block has (a) a substantially half-shaped extension member that is larger than the thickness of the cable; It has circular recesses on two sides, and (b) it has a bolt insertion hole near the center, and (c) it has a continuous tip on the outer edge of one side and the periphery of the bolt insertion hole. It has sharp, elastically deformable lips, and each pair of fan-shaped expansion member blocks is relatively fixed to a pair of fan-shaped flange blocks with bolts and nuts so that the lips face each other. A water-swellable member is disposed in at least a portion of a space surrounded by the pair of fan-shaped expansion member blocks. 2. The water stopper according to claim 1, wherein the water-swellable member is made of a super absorbent resin. 3. The water stopper according to claim 1, wherein the water-swellable member is formed of a super absorbent resin and another resin.