JPS638896B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for coating the inner surface of a small diameter pipe including a bent portion.

Conventionally, an inner surface coating method has been proposed in which a flexible hose made of synthetic resin is inserted into the pipe, and this is adhered to the inner surface of the pipe using an adhesive that has been applied to the outer circumferential surface of the hose in advance. There is. However, in such conventional inner surface coating method, if the pipe has a relatively small diameter (about 20 to 60 mm) and includes a bent part consisting of an elbow (or bend) in the middle, The flexible hose got stuck at the bent part of the pipe, and could not be inserted into the pipe from that point on, making it impossible to apply it to the inner surface coating of the pipe.

The present invention has been made for the purpose of eliminating such conventional problems, and one embodiment of the present invention will be described below with reference to the accompanying drawings.

The drawing shows an example of the case where the construction method of the present invention is applied to a gas supply light pipe, which usually has a diameter of 25 to 40 mm and a pipe length of about 2 to 10 m, and there is a pipe in the middle of the pipe. It has about 1 to 5 bent parts consisting of elbows (or bends).

Figure 1 shows the situation before construction; 1 is the gas main;
2 is a supply light tube, 3 is a gas meter, 4 is an iron kettle, and 5 is a bent part.

FIG. 2 shows an example of a flexible hose 6 for lining used in the construction method of the present invention. In order to improve the reinforcing effect, a hard wire 7 made of hard plastic or metal such as iron, copper, or copper alloy can be buried in the projection 6a. The pitch of the protrusions 6a spirally formed on the outer peripheral surface of the flexible hose 6 is not particularly limited, but if the pitch is too small, the spiral feeding effect described below will be inefficient, and if it is too large, the reinforcing effect will be reduced. The width of one pitch of the spiral should be 1 to 1/4 of the diameter of the hose 6, as this may reduce the spiral feeding effect.
The degree, particularly about 1/2, is suitable. Further, the outer diameter of the flexible hose 6 (the outer diameter of the projection 6a) is slightly smaller than the outer tube 2, and is usually about 1 to 3 mm smaller.

When carrying out the construction method of the present invention, the supply light tube 2 is removed from the gas meter 3 part from the state shown in FIG. 1, and then, as shown in FIG. As shown in 8, insert while applying adhesive to the outer peripheral surface. This insertion is carried out extremely smoothly without any particular rotation until it reaches the first bent part 5, but after the tip has been inserted to a certain extent into the first bent part 5, it gets stuck and further insertion becomes difficult. will no longer be possible.

FIG. 4 shows the state of the hose 6 when it has been inserted into the first bend 5 and it has become difficult to insert it any further. The bent portion 5 is generally composed of a screw-in elbow (or bend), and the inlet and outlet portions of the bent portion 5 are provided with concave step portions 5a based on the elbow.
is formed, so that the recessed step 5a and the spiral recess 6a' on the outer circumferential surface of the hose 6 engage with each other. In this state, when the hose 6 is rotated in the same direction as the spiral, the engaging portion exerts a screw feeding effect, and the hose 6 gradually moves toward the tip with each rotation, as shown in FIG. As shown, the hose 6 can be inserted beyond the bent portion 5. By inserting the hose 6 into the light tube 2 in this manner, the lining made of the hose 6 can be applied over the entire length of the pipe as shown in FIG.

If both ends of the pipe are open,
The terminal treatment can be easily carried out by applying appropriate means, but for example, when carrying out the terminal treatment with the other end connected to the gas main pipe 1, as in the case of the light tube 2 shown in the figure, other methods may be necessary. Terminal processing on the end side requires special measures, and for example, terminal processing means as shown in FIGS. 7 to 9 are employed.

In the terminal processing means shown in FIGS. 7 to 9,
A cylindrical part 6 for terminal treatment is provided at the tip of the flexible hose 6.
During construction, this cylindrical portion 6b is folded back and stored inside the hose tip as shown in FIG. A flexible tube 9 for blowing air is inserted into the hose 6 along its entire length, and a balloon 10 is attached to the tip of the flexible tube 9 in a folded state. The cylindrical portion 6b and the cylindrical portion 6b are linked together so that when the balloon 10 is inflated, the cylindrical portion 6b is extruded from the inside of the hose 6 together with the balloon 10.

In general, the elbow 2b provided at the tip of the togai tube 2 has a diameter of the tube portion 2b' on the side that connects to the gas body 1, which is somewhat smaller than the diameter of the togai tube 2, so that the end of the inserted hose 6 can be inserted. will stop at this part and no further insertion will be possible. Therefore, after such a state is obtained, by inflating the balloon 10 by sending air from the ground through the flexible tube 9, the cylindrical portion 6b is pushed out as shown in FIGS. 8 and 9, and its outer peripheral surface is The inner surface of the elbow 2b can be lined with an adhesive that has been applied in advance to the elbow 2b. As shown in FIG. 10, a small diameter part 6c that can be inserted into the small diameter side pipe part 2b' of the elbow 2b is connected to the distal end of the hose 6, and a cylindrical part 6b is connected to the distal end of the small diameter part 6c. This cylindrical portion 6c is used as a balloon 10.
It may be configured such that it is applied to the tip end surface portion of the elbow 2b by extrusion.

The construction method of the present invention may be applied to the lantern tube 2 in a degassed state or in a gassed state. If the work is carried out in a gas-permeable state, it is necessary to maintain airtightness during construction.

FIG. 11 shows an example of an airtight maintenance means. According to this means, the winding drum 11 of the flexible hose 6 is rotatably supported in the airtight drum 12 in the feeding direction of the hose 6, and the airtight drum 12 is supported by a bearing. 1
3 and 13 so as to be rotatable in the direction along the spiral of the hose 6. One rotating shaft 12a of the airtight drum 12 is hollow, and the hose 6 is moved between the hollow rotating shaft 12a and the shaft 12 by positively driven feed rolls 14, 14 provided in the airtight drum 12.
a and a flexible joint pipe 15 connected via a swivel joint (not shown), a terminal pipe 16 connected to the joint pipe 15, and then inserted into the light tube 2, and when necessary, the airtight drum 12. By rotating the hose 6 in a predetermined direction, the hose 6 can be rotated in the same direction as the spiral. During construction, gas flows into the airtight drum 12 from the main pipe 1;
Since it is airtight, gas will not leak outside and the purpose of airtightness can be achieved. 1 in the diagram
7 is an adhesive supply section provided in the terminal pipe 13;
As the adhesive, for example, an epoxy resin-based two-component curing type adhesive is used with the curing time adjusted appropriately. Although details of the flexible tube 9 for air blowing are omitted, for example, the rear end of the tube 9 wound together with the hose 6 is passed through the hollow rotating shaft 11a of the winding drum 11 to the airtight drum 12. If it is opened to the outside, air can be appropriately blown through this opening. This opening can be provided with a seal plug if necessary.

As described above, the present invention is capable of coating the inner surface of pipes including bent portions, and is suitable for coating the inner surface of portions of existing gas pipes and water pipes including the bent portions, such as the illustrated lighting pipes. It is extremely useful in application.

[Brief explanation of the drawing]

The drawings show a state in which the construction method of the present invention is implemented, and FIG. 1 is a longitudinal cross-sectional view showing the situation before construction, and FIG. 2 is a partial longitudinal cross-section showing an enlarged part of the flexible hose used in the construction method of the present invention. FIG. 3 is a longitudinal cross-sectional view showing the flexible hose inserted to the first bend of the light tube;
4 and 5 are longitudinal cross-sectional views showing an enlarged bending part, FIG. 6 is a vertical cross-sectional view schematically showing the situation when the inner surface coating is completed, and FIGS. 7 to 9 are examples of terminal processing means. FIG. 10 is a vertical cross-sectional view showing a modification thereof, and FIG. 11 is a vertical cross-sectional view showing an example of the airtight maintaining means. In the figure, 1 is the gas main pipe, 2 is the supply light pipe, and 3 is the gas main pipe.
is a gas meter, 4 is an iron pot, 5 is a bent part, 6 is a flexible hose, and 7 is a hard wire.

Claims (1)

[Claims] 1 An inner coating method in which a lining material is inserted and lined through an opening at one end of a small-diameter pipe including a bent part while applying an adhesive to the outer circumferential surface, and the lining material is a spiral-shaped pipe formed on the outer circumference. By using a flexible hose reinforced with protrusions and inserting this flexible hose into a small diameter pipe while applying rotation in the same direction as the spiral of the protrusions, the hose is A method for coating the inner surface of a small-diameter pipe including a bent part, which is characterized by gradually inserting and transferring from a bent part of the pipe to a subsequent part.