JP2001165385A - Water cut-off rubber for anti-corrosive pipe end cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain stickiness of a water cut-off rubber against an anti-corrosive cover so as to facilitate covering work, while attaining secure sealing of the rubber for an exposed metal face and the anti-corrosive cover. SOLUTION: An anti-corrosive cover 4 is covered over an end face 2 of a pipe 1 and a side face 1b, which is disposed in the vicinity of the pipe end and outside the pipe. The anti-corrosive cover 4, the end face 2 and the side face outside the pipe are sealed with a water cut-off rubber. This rubber includes plural extruded fins extending in the longitudinal direction on the metal face, which makes contact with the anti-corrosive cover. The remaining part of the metal face is press fitted on the pipe surface to be sealed by a contracting force of the anti-corrosive cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof rubber for a pipe end face corrosion-resistant cover for protecting a cut end face when a metal pipe such as a ductile cast iron pipe is cut.

[0002]

2. Description of the Related Art When laying a metal pipe such as a ductile cast iron pipe along an excavation groove, the pipe may be cut in order to adjust the length. In this case, as shown in FIG.
Cut one end of the opening of the
As shown in FIG. 12 (a), a groove 1b is cut out at the pipe end of the insertion port 1, and a ring 1c for the insertion projection 1a is fitted.
As shown in (b), the end of the ring 1c is fastened with a rivet 1d or the like to form the insertion projection 1a.

[0003] However, when the work is performed on site, the metal ground surface is exposed on the cut end surface 2 of the insertion opening 1 and the surface of the insertion projection 1a, so that it is necessary to perform anticorrosion work at the installation site. Therefore, conventionally, as shown in FIG. 12 (a), tapes 3 and 3 made of adhesive butyl rubber are attached to the cut end 2 of the metal tube 1 and the tube side 1e where the metal surface is exposed, and then heat shrinkage and the like are performed. The anticorrosion cover 4 is put between the tapes 3 and 3 and shrinked by heating to adhere to each other to perform anticorrosion.

In FIG. 11, reference numeral 11 denotes a receiving port at the other end of the pipe, reference numeral 12 denotes a rubber ring for sealing, which is stored in a receiving groove 11a on the inner surface of the receiving port, reference numeral 13 denotes a lock ring, and reference numeral 13 denotes a lock ring receiving groove. 11b via a centering rubber 14. The lock ring 13 prevents the insertion opening 1 from coming out of the reception opening 11 by engaging with the insertion opening projection 1a.

[0005]

However, as described above, when the anticorrosion cover 4 is put between the tapes 3 and 3, the tapes 3 and 3 made of butyl rubber are rich in adhesion. When the cover 4 is to be put on, the anticorrosion cover 4 often becomes tape 3,
No. 3, which was disadvantageous in that the coating operation was extremely difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, to suppress the adhesion to the corrosion-resistant cover, to facilitate the coating operation, and to ensure the sealing performance.

[0007]

In order to achieve the above object, a first aspect of the present invention is to provide a seal between an end surface of a tube and an outer surface of the tube in the vicinity of the end surface, the anticorrosion cover, and the end surface and the outer surface of the tube. A plurality of fins continuous in the longitudinal direction are projected from a surface in contact with the anticorrosion cover, and the other surface is pressed against the surface of the pipe by a contraction force of the anticorrosion cover so as to seal. It was made.

Therefore, according to the present invention, since the surface of the waterproof rubber is formed of only a plurality of fins, it does not adhere to the corrosion-resistant cover, while the surface against the outer surface of the tube is compressed by the shrinkage of the corrosion-resistant cover. Therefore, even if an adhesive rubber such as butyl rubber is provided on this surface, there is no danger of sticking to the anticorrosion sheet.

[0009]

Next, an embodiment of the present invention will be described. FIG. 1 is a cross-sectional perspective view of a water-stop rubber for a corrosion-resistant cover for a pipe end surface according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing another configuration example. b)
(C) shows the case where both sides are finned. FIG. 3 is an explanatory view showing the types of the form of the waterproof rubber for the pipe end face corrosion protection cover.

In FIG. 1, a water-stopping rubber (hereinafter simply referred to as "water-stopping rubber") 5 for a corrosion-resistant cover on a pipe end face is made of styrene.
A plurality of fins 5b... 5b are formed on one surface of a tape-shaped main body 5a made of rubber such as butadiene rubber (SBR) or ethylene propylene rubber (EPDM) along the longitudinal direction of the tape. Is formed with an adhesive layer 5c such as butyl rubber.

When the adhesive layer 5c of butyl rubber or the like is provided as described above, in order to improve the adhesion between the butyl rubber and the tape-shaped main body 5a, an anti-aging agent is removed from the rubber material of the tape-shaped main body 5a. A blend of EPDM with SBR is preferably used. Although the fins 5b... 5b of the water-stopping rubber 5 are formed in a comb-like shape as the cross-sectional shape, they may be formed as smooth uneven ridges as shown in FIG.

In place of the adhesive layer 5c formed on the other surface of the tape-shaped main body 5a, a plurality of fins 5d... 5d may be used as shown in FIGS. 2 (b) and 2 (c). As shown in FIG. 3, the waterproof rubber 5 has a strip-like shape 51 wound around the outer surface 1b of the metal tube 1 and a cut end 2 of the metal tube 1.
And an annular one 52 that comes into contact with the ring.

Next, a use state of the above embodiment will be described. FIG. 4 is a cross-sectional view showing a use state, and shows a use state of a detachable pipe joint having an insertion projection 1a at the insertion port 1 as a target pipe joint, and FIG. The use state of the insertion opening 1 not having is shown. First, as shown in FIG. 4, an insertion convex portion 1a is attached to the outer periphery of the cut opening 1 by welding or the like, and an annular waterproof rubber 52 is temporarily attached to the cut end 2 via an adhesive layer 5c. Then, a band-shaped waterproof rubber 51 is wound around the outer surface 1b of the metal tube 1 over the entire circumference, and is temporarily attached via the adhesive layer 5c.

Next, a corrosion-resistant cover 4 made of a heat-shrinkable plastic sheet or the like is put over the waterproof rubber 5 at the end of the pipe and the waterproof rubber 5 on the outer surface 1b of the pipe. At this time, since the fins are provided only on the surface of the water-stop rubber 5 and are not used as the adhesive surface, the covering operation of the anticorrosion cover 4 can be easily performed. Next, the anticorrosion cover 4 is placed on the hot air generator 1.
2 and shrink as shown in FIG.

At this time, the waterproof rubber 5 disposed on the end face 2 and the outer periphery 1b of the pipe is compressed as shown in an enlarged view in FIG. 6, and the fins 5b.
Further, the adhesive layer 5c of the main body 5a is pressure-bonded to the surface of each metal tube to perform a waterproof seal at the contact interface. Therefore, the fins 5b... 5b on the front surface of the water-stopping rubber 5 and the adhesive layer 5c on the back surface seal the anticorrosion cover 4 with the outer surface of the tube 1 and the end surface 2 of the tube.

Then, the end of the heat-shrinkable tube which contracts and protrudes into the pipe opening 2f is cut off to complete the anticorrosion work. FIG. 7 is a cross-sectional view showing another embodiment and relates to a straight insertion tube having no insertion protrusion. This embodiment is the same as the embodiment shown in FIG. 3 except for the presence or absence of an insertion projection, so that only the same reference numerals are given and the detailed description is omitted.

Also in this embodiment, the waterproof and corrosion-proofing is ensured by the heat-shrinkable anticorrosion cover 4 and the waterproof rubber 5. FIG. 8 is an enlarged sectional view of a main part of the embodiment in the case where the waterproof rubber 5 shown in FIG. 2A is used, and the fins 5b. This shows a state where the sheet is compressed and deformed by the shrinkable sheet.

In this case, the space between the heat-shrinkable sheet 4 and the waterproof rubber 5 is minimized.
9 and 10 are enlarged cross-sectional views of a main part of the embodiment when the water-stopping rubber 5 having the cross-sectional shape shown in FIGS. 2B and 2C is used. Between the water rubber 5 and the fin 5b which is compressed and deformed,
Seals are formed between the outer surface and the fins 5d which are similarly compressed and deformed.

In this case, a double-sided adhesive tape or the like is used as a temporary fixing means between the waterproof rubber 5 and the outer surface of the insertion opening 1 although not shown.

[0020]

As described above, according to the present invention, if the waterproof rubber for the anticorrosion cover of the pipe end is disposed at the cut section of the pipe and temporarily fixed, the adhesive layer is not exposed on the outer surface, so that the heat shrinkable tube is covered. During the operation, the operation of the heat-shrinkable tube is completed easily and quickly without any obstacle to the operation due to adhesion. Further, after coating, only the heating to a shrinkable temperature completes the complete corrosion protection of the pipe end including the insertion projection, so that the time required for the corrosion protection as a whole is very short.

Further, since the heat-shrinkable tube is thin,
Even if there is a tolerance due to the dimensions of the pipe, it does not cause an obstacle when connecting the pipe.Also, even in the case of a disconnection prevention joint, even if it is covered on the insertion projection, when the pipe is connected, an obstacle to the passage of the lock ring. It has the effect that it does not become.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional perspective view of a main part showing an embodiment of the present invention.

FIGS. 2A and 2B are cross-sectional views illustrating another configuration example of the embodiment, in which FIG. 2A is a diagram in which fins have smooth unevenness, FIG. ) Indicate comb-shaped fins.

FIG. 3 is a perspective view showing a use mode of the embodiment shown in FIG. 1;

FIG. 4 is an enlarged sectional view of a main part showing a use state of the embodiment.

FIG. 5 is an enlarged sectional view of a main part showing a use state of the embodiment.

FIG. 6 is an enlarged sectional view of a main part of a waterproof rubber portion of FIG. 5;

FIG. 7 is an enlarged sectional view of a main part showing another use state of the embodiment.

FIG. 8 is an enlarged sectional view of a main part showing a use state of another configuration example.

FIG. 9 is an enlarged sectional view of a main part showing a use state of still another configuration example.

FIG. 10 is an enlarged sectional view of a main part showing a use state of still another configuration example.

FIG. 11 is a cross-sectional view of a conventional separation prevention pipe joint.

FIG. 12 is an enlarged sectional view of a main part of a conventional separation preventing pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insertion pipe 1a Insertion convex part 2 Cutting end face 5 Pipe end face Waterproof rubber for anticorrosion cover 5a Waterproof rubber main body 5b Fin 5c Adhesive layer 5d Fin

Claims (1)

[Claims] 1. A waterproof rubber covering between an end face of a pipe and an outer face of the pipe near the end face and a waterproof rubber for sealing between the end face of the pipe and the outer face of the pipe. , A plurality of continuous fins are protruded,
A waterproof rubber for a corrosion-resistant cover on a pipe end face, the other surface of which is pressed against the surface of the pipe by the contraction force of the corrosion-resistant cover to be sealed.