JPH0355039Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a tube end surface anticorrosion core that is attached to a tube end surface and covers the tube end surface.

BACKGROUND ART A pipe whose inner surface is coated with anti-corrosion coating has a disadvantage in that when water is passed through the pipe, the water tends to cause peeling and corrosion of the coating film from the end face of the pipe at the joint. For this reason, the above-mentioned pipe end surface anti-corrosion core has been proposed.

FIG. 5 illustrates a conventional pipe end face anti-corrosion core. Here, 1 is a tube, and a coating film 2 made of anticorrosion coating is formed on the inner surface of the tube. 3 is the tube end surface. Reference numeral 4 denotes a plastic tube end surface anti-corrosion core, which has a structure in which a cylindrical tube insertion section 5 and a collar-shaped tube end surface mounting section 6 are integrally formed. According to such a configuration, by fitting the tube insertion portion 5 into the end of the tube 1, the tube end surface anti-corrosion core 4 is fitted.
is attached to the end of the tube 1, whereby the tube end surface mounting portion 6 is brought into close contact with the tube end surface 3.

Problems to be Solved by the Invention However, in the above-mentioned conventional configuration, there is a problem in that it is difficult to completely shut off water due to the presence of a gap between the pipe 1 and the pipe end anticorrosion core 4. be. Furthermore, since there are variations in the thickness of the coating film 2 and the inner diameter of the tube 1, there is also the problem that insertion into the tube 1 may be difficult or loose.

Therefore, the purpose of this invention is to solve these problems, to make it possible to completely stop water, and to be able to sufficiently deal with variations in the inner diameter of the pipe and the thickness of the coating film. shall be.

Means for Solving the Problems In order to solve the above problems, the present invention has a cylindrical pipe insertion part and a collar-shaped pipe end face device part integrally, and at least the pipe insertion part is made of water-swellable rubber. It has a structure in which a rigid member is embedded inside.

Function: With this type of tube, the tube insertion portion is made of water-swollen rubber, so even if it is larger than the tube inner diameter, it can be easily inserted due to the elastic deformation of the rubber. Furthermore, when water is passed through the tube, the rubber swells, so even if the tube insertion section is smaller than the tube, it can be properly attached by pressing it against the inner surface of the tube. In addition, this pressing force stretches the entire core onto the inner surface of the pipe, increasing the water-stopping effect.
It is possible to effectively prevent the peeling of the coating film from the end surface of the tube and the occurrence of corrosion. Further, by embedding a rigid member inside the water-expandable rubber, sufficient rigidity of the tube insertion portion can be ensured.

Embodiment FIG. 1 shows a first embodiment of the present invention. Here, 11 is a pipe, which is made of a cast iron pipe, a steel pipe, or the like. Reference numeral 12 indicates an anticorrosive coating applied to the inner surface of the tube 11, and 13 indicates an end surface of the tube.

Reference numeral 14 denotes a pipe end surface anticorrosion core according to the present invention, which includes a cylindrical pipe insertion part 15 and a collar-shaped pipe end face mounting part 1.
6 are integrally formed. Reference numeral 17 denotes an annular plastic material constituting the tube end mounting portion 16, and the cross section L is such that a portion 18 thereof is also placed inside the tube 11.
It has a character-shaped configuration. 19 is an annular water-swellable rubber made of hydrophilic urethane rubber. This water-swollen rubber 19 has a portion 18 of the plastic material 17 embedded therein, so that the water-swollen rubber 19 and the portion 18 are attached to the tube insertion portion 1.
5. That is, water-swollen rubber 19
are fitted into the tube 11 with the plastic material 17 being disposed on the inner and outer surfaces of the portion 18.

According to such a configuration, the contact portion of the tube insertion portion 15 with the inner surface of the tube 11 is made of water-swellable rubber 19. Therefore, even if the inner diameter of the tube 11 and the thickness of the coating film 12 vary and the inner tube insertion portion 15 is larger than the inner diameter of the tube 11, the elastic deformation of the water-swellable rubber 19 causes the inner tube insertion portion 15 to can be easily fitted into the tube 11.

When water is passed into the pipe 11 after joining the joint part,
The water-swellable rubber 19 absorbs water and swells, so that the entire core 14 is stretched over the inner surface of the tube 11. For this reason,
Contrary to the above, even if the tube insertion portion 15 is smaller than the inner diameter of the tube 11, the water-swellable rubber 19
1. Correct installation is achieved by being pressed against the inner surface. Moreover, this pressing force increases the water-stopping effect, and can effectively prevent peeling of the coating film 12 from the tube end surface 13 and corrosion. In addition, since the part 18 of the plastic material 17 is embedded in the water-swellable rubber 19, the rigidity of the tube insertion part 15 is sufficient.

FIG. 2 shows a second embodiment of the present invention. In this example, a plurality of claw-like portions 20 are formed in the plastic material 17 in the circumferential direction toward the inner side of the tube 11, and the claw-like portions 20 are made to protrude from the water-swellable rubber 19. This makes it easy to insert the tube insertion section 15 into the tube 11, which is particularly effective when the water flowing through the tube 11 has a low flow rate.

FIG. 3 shows a third embodiment of the present invention. In this example, water-swellable rubber 19 is provided on both sides of the plastic material 17 not only in the tube insertion part 15 but also in the tube end face attachment part 16. In this case, the water-swellable rubber 19 is also pressed against the tube end surface 13.

FIG. 4 shows a fourth embodiment of the present invention. In this example, both the tube insertion portion 15 and the tube end surface mounting portion 16 are made of plastic material 17.
Water-swellable rubber 19 is arranged only on one side.

Effects of the invention As described above, according to the invention, not only can water be completely stopped due to the swelling action of the water-swellable rubber, but even if there are variations in the pipe inner diameter or coating thickness, these can be sufficiently stopped. Can be absorbed.

[Brief explanation of drawings]

1 to 4 are views showing first to fourth embodiments of the present invention, and FIG. 5 is a view showing a conventional example. 11... Pipe, 13... Pipe end surface, 15... Intra-pipe insertion part,
16...Pipe end mounting part, 19...Water swelling rubber.

Claims (1)

[Scope of utility model registration request] A pipe end anticorrosion core that is attached to a pipe end and covers the pipe end surface, which integrally has a cylindrical pipe insertion part and a collar-shaped pipe end mounting part, and at least the pipe pipe insertion part is made of water-swellable rubber. What is claimed is: 1. A corrosion-protective core for a pipe end face, characterized by having a structure in which a rigid member is embedded inside the core.