JP2652655B2 - Internal lining method for existing pipes - Google Patents

Description

The present invention relates to a method for lining an existing pipe such as an aged sewer pipe.

[Prior art] As a measure to extend the useful life of an aging existing pipe that has caused internal corrosion or cracks, the existing pipe may be lined with an inner surface, and one of the inner lining methods is a synthetic resin lining. For example, after inserting a long connected body of reinforced plastic short pipes such as FRP into an existing pipe, fill the gap formed between the existing pipe and the connected body with a filler such as a cement mill. In some cases, an internal passage of the connected body is used as a new passage by holding the connected body to an existing pipe via the filler.

In such an inner surface lining method, after the uncured filler is injected into the gap, a load due to the weight of the filler is applied to the connected body until the filler is cured. For this reason, it is necessary that the connecting body has such a strength that it is not deformed by the load.

Therefore, conventionally, the required strength required for the connected body has been ensured by increasing the thickness of the tube wall of the short tube.

[Problems to be solved by the invention]

By the way, although the lining layer formed on the existing pipe by the above-described method has a two-layer structure of the filler and the pipe wall of the connected body, the filler itself has shape retention by curing, so The load due to the weight of the material is not applied to the connected body. As a result, considering only the state after the filler has hardened, it is not necessary to increase the thickness of the tube wall of the connecting body, that is, the tube wall of the short tube.

However, conventionally, it is necessary to increase the thickness of the tube wall of the connected body so that the connected body is not deformed by the load due to the weight of the filler until the uncured filler is hardened as described above. Due to the necessity, the thickness of the tube wall of the connecting body becomes unnecessarily thick after the filler is hardened, which has led to a problem that the cost is increased and the workability is deteriorated due to an increase in weight. This tendency becomes more pronounced as the diameter of the connected body increases.

The present invention has been made in view of the above circumstances, and even when the pipe wall of the connected body is thinned, the inner surface lining of the existing pipe is not deformed by the load due to the weight of the uncured filler. The aim is to provide a method.

[Means for solving the problem]

The method for lining the inner surface of an existing pipe according to the present invention comprises inserting a flexible tube through a connecting body inserted into the existing pipe, sending fluid into the tube to make it rigid, and using the rigidized tube to connect the connecting body with the rigidized tube. The pipe wall is backed up from the inside, and in this state, an uncured filler is put into a gap formed between the existing pipe and the connector, and the tube is removed after the filler is cured.

(Operation)

According to this method, the load due to the weight of the uncured filler injected into the gap between the existing pipe and the connector is substantially supported by the rigidified tube. Further, when the filler is hardened, the filler itself has a shape retaining property. Therefore, even if the tube is removed, the connected body is not deformed by the load due to the weight of the filler.

〔Example〕

FIG. 1 shows a state in which a connecting body 2 is provided inside a straight existing pipe 1, and FIG. 2 shows a state in which a fluid pressure is applied to a tube 3 inserted into the connecting body 2 to make the tube 3 rigid. Is shown.

Existing pipe 1 to be subjected to inner lining by connecting body 2
There are various types such as a sewer pipe consisting of fume pipes buried in the ground and a drain pipe for factory waste liquid, and when manholes 4 and 4 are provided in the middle of the pipe as shown in the figure, In this case, various operations such as insertion of a short pipe and insertion of a tube, which will be described later, can be performed without difficulty using the manholes 4 without cutting the existing pipe 1. The internal surface of the existing pipe 1 is washed by an appropriate means such as jet water jet before the connection body 2 is provided, and solid foreign matters and the like inside the pipe 1 are removed in advance.

The connecting body 2 includes a plurality of short tubes 5 inserted from the manhole 4.
Are often connected inside the existing pipe 1, but it is not always necessary to connect inside the existing pipe 1, and in some cases, the short pipe may be connected outside the existing pipe 1 (for example, at a construction site or a factory). 5 may be connected to form a connected body 2, and the connected body 2 may be inserted into the existing pipe 1 from one end side. As shown in FIG. 7, the short pipe 5 shown has a receiving port 51 on one end side and a port 52 on the other end side, and is connected by inserting the port 52 of another short pipe 5 into the receiving port 51. The resilient seal ring 6 held in the receiving port 51 is pressed against the spigot 52 inserted in the receiving port 51 to maintain necessary liquid tightness.

A tube 3 is attached to the connecting body 2 provided inside the existing pipe 1.
Is inserted in a state of being folded flat, for example, and air or water is fed into the tube 3 after the insertion to inflate the tube 3 as shown in FIG. 2, and the tube 3 is made rigid by air pressure or water pressure. Alternatively, the tubes 3 may be inserted into the connecting body 2 while being reversed by fluid pressure, and may be rigidified. Then, the tube wall of the connecting body 2 is backed up from the inside by the rigidized tube 3. Thereafter, an uncured filler is injected into the gap S formed between the existing pipe 1 and the connector 2, and the tube is removed after the filler is cured. In this case, the load due to the weight of the uncured filler injected into the gap S is substantially supported by the rigidized tube 3, and thus the tube wall of the connecting body 2, that is, the tube of the short tube 5 is formed. Even if the wall is made thin, the tube wall is not deformed by the load. Also, after the filler has hardened, the filler itself has shape retention,
Even if the tube 3 is removed, the connected body will not be deformed by the load due to the weight of the filler.

As described above, the tube 3 needs to keep the fluid pressure high in order to substantially receive the load of the filler. Therefore, as the material of the tube 3, a glass fiber non-woven fabric impregnated with neoprene rubber, an organic fiber cloth impregnated or coated with a resin, rubber, or the like, a cloth sandwiched with a resin, a rubber, or the like is used. Is preferred. Also,
The tube 3 is inserted into the connector 2 using the manhole 4, and it is desirable that both ends of the tube 3 be positioned by predetermined holders 7, 7. In addition, air supply or water supply to the tube 3 may be performed from the ground. In order to apply a predetermined air pressure or water pressure to the tube 3, the tip of the tube 3
Of course, 31 is closed.

Incidentally, since the outer diameter of the short pipe 5 is set to be slightly smaller than the inner diameter of the existing pipe 1, the short pipes 5, 5 connected to each other are connected.
Between the short pipes 5 as shown in FIG. 7, even though the existing pipes 1 are straight.
May not be connected straight. If the existing pipe 1 is an aging pipe, such bending of the connecting portion occurs relatively remarkably in the case where there are irregularities, solids that have not been washed away by washing, and the like on the inner surface thereof. And the short pipe 5,5
If the connecting portions are bent, for example, when water flows in the direction of the arrow A in the drawing, a portion showing an upward slope may be formed in the middle of the pipeline. Such bending of the connecting portion also occurs when short pipes are connected to each other by a connecting structure other than that shown in the drawing, for example, when the short pipes are connected using a joint.

However, according to the method of the present invention, the bending at the connection point is naturally corrected as follows. In other words, in the process of inflating the tube 3 inserted into the connecting tube 2 by air pressure or water pressure to make it rigid, the tube 3 is forcibly displaced so that the short tubes 5, 5 are arranged along the tube 3. The connecting point between the short pipes 5,5 that are bent like this is straightened.

In the new passage formed by the above method, there is no deformed portion on the pipe wall of the connecting body 2 and there is no portion showing an upward gradient in the middle thereof, so that sewage and waste liquid flow smoothly, and the solid content Is less likely to be deposited. The short pipe 5 can be suitably made of FRP made by impregnating a reinforcing material such as glass fiber with an unsaturated polyester resin.

In the above method, a hardening type filler such as cement milk or an adhesive is used as the filler. Since the connecting body 2 provided inside the existing pipe 1 is placed on the bottom surface of the existing pipe 1 as shown in FIG. 3, the gap S is wider at the upper part and there is almost no gap at the lower part. become. Therefore, if an uncured filler is put into the gap S from this state, there is a problem that the filler does not uniformly enter the periphery of the connecting body 2. An example of a means that can solve such a problem will be described below. Note that, in this example, a light-weight connecting body 2 in which short pipes made of FRP are connected is used.

First, as shown in FIG. 4, a required amount of cement milk C, which is a filler heavier than FRP, is injected into the gap S to float the connecting body 2 on the cement milk C inside the existing pipe 1 so that the connecting body 2 2 is arranged concentrically with the existing pipe 1, and after the hardening of the cement milk C, the cement milk C is injected or press-fitted into the remaining upper gap S, and the cement milk C is hardened to connect the cement milk C as shown in FIG. 2 is held in the existing pipe 1. If the cement milk C is filled twice in this manner, the connected body 2 may be further lifted by the second filling, but this point is, for example, to leave the tube 3 inserted through the connected body 2 as it is. By adding the weight of the water W injected into the tube 3, it is possible to prevent the connecting body 2 from floating.

Although the above-described embodiment is directed to the case where the straight connecting body 2 is internally lined to the straight existing pipe 1, the present invention can be similarly applied to the case where the internal pipe is bent and laid on the existing pipe. . The tube used in this case needs to be bent to the same shape as the existing tube when inflated by fluid pressure.

〔The invention's effect〕

According to the present invention, as long as the filler is uncured and has no shape-retention itself, even if a load due to the weight of the filler is applied to the tube wall of the connected body, the tube wall is backed up by the rigidified tube. No deformation. Therefore, it is possible to reduce the thickness of the tube wall of the connecting body, and it is possible to reduce the material of the short pipe constituting the connecting body, for example, the material of a reinforced plastic such as FRP, thereby achieving cost reduction. Further, the short pipe can be lightened, the workability of insertion into the existing pipe and the like can be improved, and the transportation can be easily performed.

Also, since the tube is inserted into the connecting body and the fluid is sent in to make it rigid, the bending angle of the connecting portion of the short pipe that constitutes the connecting body is properly corrected, so a new construction consisting of a connecting body There is also an advantage that there is no place showing an upward slope from the passage.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a state in which a connecting member is provided inside an existing pipe, FIG. 2 is a state in which a tube inserted into the connecting member is made rigid by applying a fluid pressure, and FIGS. FIG. 7 is a longitudinal sectional front view showing a series of steps from the step of disposing the connector inside the existing pipe to the step of holding the connector on the existing pipe, FIG. 7 is an enlarged longitudinal side view showing a bent portion of the connector, FIG. The figure is an enlarged vertical sectional side view showing a state in which the bending angle of the connecting body is corrected. 1 ... existing pipe, 2 ... connected body, 3 ... tube, 5 ...
Short tube.

Claims (1)

(57) [Claims] 1. A method for lining an existing pipe in which a plurality of short pipes made of synthetic resin are held in the existing pipe, wherein a flexible tube is inserted through the connection body inserted into the existing pipe. A fluid is fed into this tube to make it rigid, and the tube wall of the above-mentioned connected body is backed up from the inside by the stiffened tube, and the uncured filler is filled in the gap formed between the existing pipe and the connected body in this state. And removing the above-mentioned tube after the filler has hardened, the inner surface lining method of an existing tube.