JPH04305433A - Method for inserting rigid plastic flat pipe for lining in pipeline - Google Patents

Abstract

PURPOSE:To insert an flat pipe in a pipeline without almost generating elongation or a scratch in the flat pipe. CONSTITUTION:When a rigid plastic flat pipe 1 for lining is inserted in a pipeline 2 in a heated and softened state while drawn out of a roll, the flat pipe 1 is held between two non-stretchable and flexible holding belts 3 capable of holding both flat surfaces of the flat pipe 1 while press rolls are adapted between both belts on this side of the inlet of the pipeline 2 and inserted in the pipeline 2 as the holding belts 3 are drawn in the pipeline 2. After insertion, the holding belts 3 are released from the pressing action of the press rollers 8 to be brought to a state free from the flat pipe 1 and drawn out of the pipeline 2 to be recovered.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inserting hard plastic flat pipes for lining into pipes.

0002

[Prior art and its problems] As a conventional method for lining the inner surface of a pipe, a hard plastic pipe is used as the lining material.
A construction method has been proposed in which after this hard plastic pipe is inserted into a pipe, it is heated and pressurized from the inside to expand in the radial direction of the pipe and adhere to the inner surface of the pipe. According to this running construction method, since the inner lining is made of a hard plastic pipe, it has shape retention and high strength, and is attracting attention because it provides a high quality inner lining.

[0003] The hard plastic pipes used in the above construction method are rigid at room temperature and cannot be bent in their circular shape. During the manufacturing process, the product is extruded into a circular tube shape, then crushed in the radial direction of the tube, shaped into a flat tube, and if necessary, folded in half from the flat tube shape and wound onto a drum.
The drum is transported to the construction site in this state. During the process of inserting the flat tube into the pipe, the flat tube is heated and softened to enable it to be pulled out from the drum.

[0004] Insertion of a hard plastic flat tube into a conduit is usually carried out by a pulling operation using a pulling rope, and since a considerable amount of pulling resistance is generated during this pulling operation, the flat tube may be elongated or even Scratches may occur due to friction with the inner wall, which may cause tube rupture during the heating, pressurizing, and expanding operations that follow the insertion process, and may also cause uneven thickness of the inner lining, both of which are undesirable.

[0005] The present invention has been made with the object of further alleviating these conventional problems.

[0006]

[Means for Solving the Problems] The present invention provides a method for inserting a hard plastic flat tube for lining into a conduit while pulling it out from a roll in a heated and softened state, from both sides of the flat surface of the flat tube. Using a set of two non-stretchable and flexible holding belts that can be held by clamping them, the flat pipe is held between the two belts with the application of pressure rolls in front of the entrance of the pipeline. At the same time, the flat tube is inserted into the conduit as the holding belt is drawn into the conduit, and after insertion, the holding belt is released from the pressure of the presser roll and is pulled out from the conduit and collected in a state where it is free from the flat tube. The present invention relates to a method for inserting a hard plastic flat pipe for lining into a pipe line, which is characterized by the following.

[0007]

[Example] The implementation status of the construction method of the present invention will be explained below based on the attached drawings.

FIGS. 1 and 2 schematically show the process of inserting a hard plastic flat tube 1 into a conduit 2. The flat tube 1 is softened by applying heating means according to a conventional method and is then pulled out from a drum (not shown) installed on the ground.

A non-stretchable and flexible holding belt 3 is disposed on both sides of the flat surface 1a of the flat tube 1, and the belt 3 is pulled out parallel to the flat tube 1 from a ground-mounted drum (not shown). It is now possible to do so.

As shown in FIG. 3, the holding belt 3 has a width comparable to that of the flat tube 1 so that it can come into contact with the flat surface 1a of the flat tube 1 over almost its entire surface. The holding belt 3 is made of rubber, for example, and is prevented from expanding or contracting at least in the length direction by an embedded reinforcing material (not shown) such as a woven fabric.

FIG. 1 shows the situation at the start of the insertion work. When the work starts again, a pair of holding belts 3, 3 are first moved from a drum (not shown) installed on the ground to a guide roll 7. As it passes through, it is pulled out to the entrance of the conduit 2 through a pair of upper and lower presser rolls 8 while changing direction from the vertical direction to the horizontal direction, and at this position, it is attached to the tip of the traction rope 4 that has been passed through the conduit 2 in advance. They are connected via a connector 5, and a gap 6 approximately corresponding to the thickness of the flat tube 1 is formed between both belts 3, 3 at the connecting portion.

Further, the flat tube 1 is pulled out from a drum (not shown) installed on the ground in a heated and softened state. The drawn flat tube 1 passes between the holding belts 3, 3, changes direction from the vertical direction to the horizontal direction when passing the guide roll 9, and then passes between the presser rolls 8, 8, and passes between the belts 3, 3. It is held between the By this frictional engagement in the clamping portions 3a, the starting end of the flat tube 1 is substantially integrated with both belts 3, 3, and all preparations for starting work are finally completed.

In the state shown in FIG. 1, when the holding belts 3, 3 are pulled into the pipe line 2 via the tow rope 4, the clamping portion 3
The flat tube 1, which is integrated with the holding belts 3, 3 by the frictional engagement at point a, is drawn into the pipe line 2 together with the holding belts 3, 3. Immediately after the start of work, the frictional engagement force in the clamping portion 3a is insufficient, which may hinder the accompanying movement. In such cases, the flat tube 1 should not be held until the accompanying movement begins. It is only necessary to actively feed it toward the conduit 2 by manual operation or the like.

As shown in FIG. 2, when the drawing into the pipe 2 progresses to a certain extent, the frictional engagement area of the clamping portion 3a increases and sufficient frictional engagement force is obtained, so that from then on, active feeding is performed. belt 3, which holds the flat tube 1 without the need for
3 can accompany the movement within the pipe. By continuing to pull in the holding belts 3, 3 using the pulling rope 4 in this state, the flat tube 1 can be inserted over the entire length of the conduit 2.

In order to assist the accompanying movement at the initial stage of the retracting operation, as shown in FIG.
0 may be connected to the connector 5.

During the insertion operation of the flat tube 1 into the conduit 2, the pulling resistance is received by the holding belts 3, 3, and the flat tube 1
Since this has little effect on the flat tube 1, it is possible to insert the flat tube 1 into the conduit 2 without the risk of the tube 1 being stretched.

Furthermore, since the flat tube 1 is protected from friction with the inner wall of the conduit 2 by the holding belts 3, 3, the flat tube 1 is protected from friction with the inner wall of the conduit 2.
The risk of getting scratched by friction with the inner wall is reduced. After the insertion operation into the pipe line 2 is completed, the presser rolls 8, 8 are removed from the entrance side of the pipe line 2, as shown in FIG.
The holding belts 3, 3 are released from the pressure of the presser rolls 8, 8. By releasing this pressure, the holding belts 3, 3 are attached to the flat tube 1.
becomes free, and in this state, the holding belt 3,
3 out of the conduit 2, the flat tube 1 can be recovered while remaining in the conduit 2. During this recovery operation, in order to reduce the weight load of the flat tube 1 on the lower belt 3 as much as possible, tension should be applied to the flat tube 1 so that the flat tube 1 slightly floats in the conduit 2. is preferred. In FIG. 5, reference numerals 11, 12, and 13 are guide rolls installed on the outlet side of the pipe line 2, and a rope 15 is connected to the starting end of the flat pipe 1 via a connector 14.

[0018]

[Effect] According to the method of the present invention, it is possible to insert the flat tube into the pipe line without causing any elongation or scratches, and there are no concerns in the next step of heating, pressurizing and expanding the tube. This eliminates the causes of troubles such as tube rupture caused by heat and pressure expansion, and at the same time contributes to improving the quality of the inner lining formed by heating and pressurizing expansion.

[Brief explanation of drawings]

[Figure 1] Explanatory diagram showing the situation at the start of construction using the method of the present invention

[
Figure 2: Explanatory diagram showing the situation during construction using the method of the present invention

[Figure 3
]A cross-sectional view taken along line A-A in Figure 2.

[Figure 4] Vertical cross-sectional view showing the starting end of a flat tube connected to a connector via a spring

[Figure 5] Explanatory diagram showing the recovery status of the holding belt

[Explanation of symbols]

1 Flat tube 2 Pipeline 3 Holding belt 4 Tow rope 5 Connecting tool 6 Interval 7 Guide roll 8 Presser roll 9 Guide roll

Claims (1)

[Claims] 1. A hard plastic flat tube for lining that can be held by clamping it from both sides of the flat surface when the hard plastic flat tube is inserted into the conduit while being pulled out from the roll in a heated and softened state. Using a set of two stretchable and flexible holding belts, the holding belts are pulled into the pipe while holding the flat pipe between the two belts using presser rolls before the entrance of the pipe. A hard plastic for lining, characterized in that the flat tube is inserted into the conduit as the process progresses, and after insertion, the holding belt is released from the pressure of the press roll and is pulled out from the conduit and collected in a state free from the flat tube. A method for inserting flat pipes into pipelines.