JPH01263028A - Covering method for inner periphery of conduit - Google Patents

Abstract

PURPOSE:To form a rigid coating layer on the inner periphery of a conduit by disposing an unreacted material tube in the conduit, applying a pressure difference to the tube to extend it, press-bonding it to the inner periphery of the conduit, and reaction curing the tube. CONSTITUTION:A tube 7 made of an unreacted material having a plenty of shrinkability and flexibility such as unreacted resin, unreacted rubber, etc., is folded, one side end 7a of the tube 7 is closed to be formed in a bag state, the other side end 7b of the tube 7 is extended in its diameter, and narrowed by the flange 2 of a pipe 1 and a cover 8. When compressed gas is gradually poured from the nozzle 10 of the cover 8 into the tube 7 to be pressurized, or the air in the pipe 1 and a short tube 4 is discharged from the nozzle 11 of a cover 9 to be reduced under pressure while the nozzle 10 remains opened, the tube 7 is gradually expanded from the end 7b to be brought into pressure contact with the inner periphery of the pipe 1, and eventually brought into pressure contact with the whole length of the pipe 1. When this state is left to stand for, the tube 7 is naturally reacted progressively, the tube 7 is cured while in contact with the inner periphery of the pipe 1, thereby forming a rigid coating layer.

Description

[Detailed Description of the Invention] LL 1 per 5 ri 1 The present invention involves attaching a duplex made of an unreacted material such as unreacted resin or unreacted rubber to the inner circumferential surface of the pipe, and then reacting and hardening this tube. The present invention relates to a method for coating the inner circumferential surface of a conduit by which a strong coating layer can be formed on the inner circumferential surface of the conduit.

In order to prevent rust and corrosion on the inner peripheral surface of the pipe and to prevent the adhesion of foreign matter, it was highly necessary to coat the inner peripheral surface of the pipe.

In order to meet this need, conventionally, a resin tube with the required elasticity 1 strength that has undergone a reaction or a seal boce with a reinforcing layer is placed inside the conduit, and this resin tube or The seal hose was attached to the inner peripheral surface of the pipe with adhesive.

However, resin tubes and seal hoses incorporating reinforcing layers, which provide the required elastic strength after the reaction has been completed, lack elasticity, so the outer diameter of these tubes and seal hoses does not match the inner diameter of the pipe. If the tube or seal hose is smaller than the inner diameter of the pipe, there will be a portion where the tube or seal hose cannot adhere tightly to the inner circumferential surface of the pipe.
Wrinkles appeared on these.

Furthermore, if the conduit is curved, the radius of curvature on the inside and outside of this curved portion is different, making it impossible for the tube or seal hose to make close contact.

Furthermore, resin tubes that have completed the reaction and seal hoses that incorporate reinforcing layers lack flexibility, so if there are irregularities on the inner circumferential surface of the conduit, these tubes or seal hoses may It cannot be completely adhered to without any gaps,
Air remains on the outer peripheral surface of the tube or seal hose and the inner peripheral surface of the conduit, and when this air is heated and expanded, the tube or seal hose floats up from the conduit, causing separation.

・The present invention relates to an improvement of a method for covering the inner circumferential surface of a pipe that overcomes such difficulties, and is in a state where the elastic strength, etc. that it should originally have when using the material is not reached. A duplex made of an unreacted material whose circumferential length is less than or equal to the circumference of the inner circumferential surface of the conduit is disposed in the conduit, and the tube is expanded by applying a pressure difference to the inner circumferential surface of the conduit. This method is characterized in that the tube is reacted and hardened after being crimped.

In the present invention, as described above, a pressure difference is applied to the unreacted material conditioning tube, which has not reached the original elasticity 1 strength etc. that it should have when the material is used, and the tube is expanded to the inner circumferential surface of the conduit. Even if the diameter of the inner circumferential surface of the conduit changes or the inner circumferential surface is uneven or the conduit is curved due to crimping, the tube can be crimped to create wrinkles on the inner circumferential surface of the conduit. It can be attached completely without any gaps.

In the present invention, after the tube is brought into close contact with the inner circumferential surface of the conduit, the tube is cured by reaction.
A strong coating layer can be formed on the inner peripheral surface of the pipe.

As described above, according to the present invention, the tube is brought into close contact with the inner circumferential surface of the conduit completely without wrinkles or gaps, so that air is not allowed to flow between the inner circumferential surface of the conduit and the tube. Even if the inner peripheral surface of the cough duct and the tube are heated, it is possible to prevent the tube from floating or peeling off due to expansion of the residual air.

Further, in the present invention, after the dupe is brought into close contact with the inner circumferential surface of the pipe, the dupe is reacted and hardened, so that a strong coating layer can be formed on the inner circumferential surface of the pipe. It is possible to reliably protect the inner peripheral surface for a long period of time, preventing rust, corrosion, and adhesion of foreign substances.

Point-1-1 An embodiment of the tree 1-1 shown in FIGS. 1 to 3 will be described below.

A flange 2 and a flange 3 are integrally connected to both ends of a vibrator 1, and 7 flange 5 and 7 flange 6 are integrally connected to both ends of a short tube 4 having the same diameter as the vibrator 1, which constitutes a pipe line. , the vibrator 1 and the short tube 4 are 7 lunges 3. They are connected at a flange 5 so that they can be freely approached and separated.

Further, the tube 7 made of an unreacted material with high elasticity and flexibility, such as unreacted resin or unreacted rubber, is folded as shown in FIG. 4, and one end 7a of the tube 7 is closed. The tube 7 is formed into a bag shape, and the other end 7b of the duplex 7 is expanded in diameter to form a flange 2 of the vibrator 1.
The other open end 7b of the tube 7 is sandwiched between the 7 langes 2 of the vibrator 1'' and the lid 8 by applying the lid 8 to this and tightening with bolts (not shown).

Furthermore, the cover 9 is airtightly attached to the flange 6 of the short pipe 4, and the N
Compressed gas is gradually injected into the tube 7 through the nozzle 10 of the lid 9 to pressurize it, or the vibrator 1. When the air in the short tube 4 is exhausted and the pressure is reduced, the tube 7 gradually expands from the other end 7b and comes into pressure contact with the inner peripheral surface of the vibrator 1, as shown in FIG. As shown in FIG. 3, the tube 7 is pressed over the entire length of the vibrator 1.

If this state is left as it is, the tube 7 will naturally undergo a reaction, and the tube 7 will harden while remaining in close contact with the inner peripheral surface of the vibrator 1, forming a strong coating layer.

In addition, if the reaction is heated to accelerate the reaction, the time required to complete the reaction will be shortened.

Furthermore, since the tube 7 is made of an unreacted material that is highly stretchable and flexible, even if the vibrator 1 is partially thick or thin, the tube 7
When the tube 7 is inflated, the inner peripheral surface of the vibrator 1 is not wrinkled and has no gaps. ! You can wear it.

Furthermore, since the tube 7 is highly elastic, it is not necessary to make the outer circumference of the tube 7 approximately equal to the inner circumference of the vibrator 1, and it is possible to shorten the outer circumference of the tube 7 and make the tube 7 thick. When the tube 7 is drawn into the pipe 1, the contact portion with the inner circumferential surface of the vibrator 1 is narrowed, and the tube 7 can be easily placed inside the vibrator 1.

In addition, in order to heat the tube 7 evenly and sufficiently in order to promote the reaction of the tube 7, as shown in FIG. By pinching the end 7b of the running body 14 and applying pressurized fluid to the back of the running body 14 fitted in the short pipe 12, the running body 14 is run toward the one end 7a of the duplex 7. The heater 15 of the traveling body 14 may be energized from the power source 16 to heat the traveling body 12, and in such an embodiment,
The tube 7 is not only pressed against the inner circumferential surface of the vibrator 1 by the pressure of the pressurized fluid, but also mechanically pressed against the inner circumferential surface of the vibrator 1 by the traveling body short tube 12, so that the inner circumferential surface of the vibrator 1 Now tube 7 can be crimped more tightly.

Note that the adhesive force between the inner peripheral surface of the vibrator 1 and the tube 7 is
If sufficient adhesive cannot be obtained, it is of course possible to apply the adhesive to the inner circumferential surface of the vibrator 1 or the outer circumferential surface of the tube 7 in advance using another method.

As described above, according to the present invention, since the tube is completely attached to the inner circumferential surface of the conduit without wrinkles or gaps, air is not allowed to flow between the inner circumferential surface of the conduit and the tube. Even if the inner circumferential surface of the conduit and the tube are heated, it is possible to prevent the tube from floating or peeling off due to expansion of the residual air.

Further, in the present invention, after the tube is brought into close contact with the inner circumferential surface of the conduit, the tube is subjected to reaction hardening, so that a strong coating layer can be formed on the inner circumferential surface of the conduit. It is possible to reliably protect the inner circumferential surface of the road for a long period of time, and prevent rust, corrosion, and adhesion of foreign matter.

[Brief explanation of the drawing]

1 to 3 are longitudinal sectional side views illustrating an embodiment of the method for coating the inner peripheral surface of a pipe according to the present invention, in which FIG. 1 is an initial stage, FIG. 2 is an intermediate stage, and FIG. The state at the end of the process is shown, and FIG. 4 is a side view showing the folded state of the tube, and FIG. 5 is a longitudinal sectional side view of another embodiment. 1...vibrator, 2.3...flange, 4...mf
2.5゜6...7 lunge, 7...tube, 8.9
...Lid, 10°11...Nozzle, 12...Short pipe,
13...Flange, 14...Running body, 15...Heater, 16...Power source.

Claims (1)

[Claims] A tube made of an unreacted material that has not reached the elasticity, strength, etc. that it should originally have when the material is used, and whose circumference is less than or equal to the circumference of the inner circumferential surface of the conduit, is placed in the conduit, and the tube is A method for coating an inner circumferential surface of a conduit, which comprises expanding the tube by applying a pressure difference to press the tube against the inner circumferential surface of the conduit, and then reaction-hardening the tube.