JPH0814346B2 - Subdivision method of space in pipeline - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subdivision method for forming a plurality of small-diameter pipes in an existing buried pipe.

Conventional technology and its problems Communication cables and electric power cables are often inserted into underground pipelines, especially in urban areas. There is usually an empty space in the existing buried pipeline used for inserting this kind of cable, and this empty space is used for inserting communication cables and other various cables due to the increasing demand due to the sophistication and diversification of communication technology. There is a tendency. However, since this type of conduit has a single passage inside, the existing old cable may be damaged when a new cable is inserted, and various cables of different uses and types may be inserted into a single passage. Then, there is a problem that the insertion state becomes cluttered, it becomes difficult to distinguish the cables, and it is impossible to replace the cables, which is inconvenient for wiring work and other maintenance and maintenance.

The present invention has been made for the purpose of eliminating such conventional problems.

Means for Solving the Problems The present invention provides a plurality of small pipes using a plurality of small-diameter rigid plastic pipes in an existing buried pipeline between one shaft and another shaft. A method of forming a passage, in which a plurality of small-diameter hard plastic pipes wound in a roll shape in a state of being processed into a flat pipe from an i-shaped pipe is installed near one vertical shaft, and In the installed state,
A first step of heating and softening each plastic pipe to a state where it can be pulled out from a roll, ii A pipeline for opening a plurality of the heat-softened plastic pipes into the shaft from the roll while maintaining the heat-softened state. The second step of drawing out toward the front position of the inlet and supplying the pressurized fluid into the plastic pipe to restore the pipe withdrawal part from the flat tubular shape to the original circular tubular shape, and iii to the front position of the pipeline inlet A plurality of drawn out circular tubular restored plastic pipes are moved along the extension line of the central axis of the pipeline from the front position toward the pipeline inlet while maintaining the heat-softened state. Iv, during the movement along the extension line in the above-mentioned third step, the plurality of plastic pipes are cooled and solidified while gathering in a polygonal cross-section, and then drawn from the pipe inlet to the inside thereof. Nde go, it according to the subdivision method of the conduit space, wherein.

In the method of the present invention, the small-diameter hard plastic pipe used for subdividing the space in the pipeline is wound into a roll under the flattened tubular working state, so that this is, for example, 200 to 400 m. Even if it has a length that exceeds it, it can be brought into the construction site and installed without any problems. Furthermore, the hard plastic tube can be pulled out by heating and softening, and the pressurized fluid supplied internally during the withdrawal restores it from a flat tubular shape to a circular tubular shape. Can be inserted in the state. Moreover, each plastic tube that has been restored to a circular tubular shape is assembled into a polygonal cross-section and cooled and solidified on the extension line of the central axis of the pipeline before the entrance of the pipeline, so that the pipe is in a rigid state. That is, it can be inserted in a state in which it has the smallest frictional resistance with the pipe line, and in a state in which it is aligned, that is, in a state in which it can smoothly pass through the pipe line along the central axis, for example, 20
Even when it is inserted into a pipe having an ultra-long span of 0 to 400 m, the purpose of the insertion can be safely and reliably achieved without causing troubles such as pipe cutting. Therefore, in the method of the present invention, an ultra-long span of about 200 to 400 m is used as one construction length, and the subdivision method can be carried out efficiently.

Example An example of the method of the present invention will be described below with reference to the accompanying drawings. Although the drawing shows the case where three subdivision pipelines are formed by applying the method of the present invention, the number of subdivision pipelines is not particularly limited.

In carrying out the method of the present invention, three small-diameter hard plastic pipes (2) are used to divide the existing buried pipeline (1) into three subdivided passages.

The hard plastic tube (2) is a circular tube and is molded from a thermoplastic synthetic resin having a relatively low softening point (for example, 60 to 100 ° C) such as vinyl chloride resin, polyethylene, polypropylene, etc., and is assembled (Fig. 5). (See), it has an outer diameter that allows it to be loosely inserted into the conduit (1).

The hard plastic pipe (2) is the length of the pipe (1) between the two manholes (1a) (1b) to be constructed (for example, 20
It has a length slightly exceeding 0 to 400 m) and is carried into the construction site in a state of being wound into a roll on a drum (3) in the form of a flat tube.

On the construction site, on the other hand, a heat insulating casing (4) and a drum supporting device (5) housed in the casing (4) are installed near the manhole (1a), and a rotating vertical axis (5a) of the device (5) is installed. ) 3 drums (3) on top and bottom with 3 drums sideways
It is mounted so as to rotate integrally with the vertical axis (5a) that wins the step.

The vertical axis (5a) is hollow and constitutes a part of the passage for supplying pressurized fluid into the plastic tube (2) for winding the drum, and the upper end thereof has a swivel joint (6) and a supply line (7). ) To a pressurized fluid supply unit (not shown), and the side portion is connected to a rear end (end on the drum center side) of the plastic pipe (2) via a connection line (8).

One end side of the connection line (8) is connected to the rear end side of the plastic pipe (2) at a rear end side of the plastic pipe (2) so that a pressurized fluid can be supplied, when the plastic pipe (2) is wound around the drum (3), The other end is pulled out from the side plate of the drum (3) and is detachably connected to a connection port (not shown) on the side of the vertical axis (5a).

Inside the manhole (1a), the assembly guide mechanism (9) for the plastic pipe (2) is provided at a portion from the inlet side of the pipe line (1).
A horizontal heat-insulating duct (10) having a pipe (1) is installed at the front end of the duct (10) so as to face the inlet of the pipe (1) and project forward. Exit passage (11)
Is provided. The outlet passage (11) is made of a metal member, and cooperates with the cooling fluid supply device (12) installed above the outlet passage (11) to cool and solidify the plastic pipe (2) passing through the inside.

In the horizontal heat insulation duct (10), as shown in FIG. 3, three front conduits (13) are inserted and installed in advance.
As 3), a material having the same diameter as the plastic tube (2) or a different material having the same diameter as that of the plastic tube (2) is used.

As shown in FIG. 3, the front end (13
a) is drawn out forward from the outlet passage (11) of the horizontal heat insulation duct (10) under the assembled state, and is connected to the pipe (1) in advance by the connecting tool (15) at the tip of the towing line (14). ) Is connected and fixed. On the other hand, the rear end portion (13b) of the front conduit (13) extends from the inlet (10a) at the rear end of the duct through the inclined heat retaining duct (16) to the outlet (4a) of the heat retaining casing (4), At this position, it is connected in an internal communication state to the circular tubular restoration part (2a) at the front end of each stage of the plastic pipe (2) that is preliminarily pulled out.

FIGS. 4 (a) to 4 (d) are explanatory views of the principle of the assembly guide mechanism (9). The action of the horizontal rolls (9a) ... and the vertical rolls (9b) indicates that the point A shown in FIG. When the three parallel plastic pipes (2) [or the leading conduit (13)] reach the point D through the points B and C, they are gathered in a substantially triangular shape.

At the start of construction, the heating fluid, for example, heating air, in the state shown in FIG. 3, is fed through the heat retaining casing (4), the inclined heat retaining duct (16) and the horizontal heat retaining duct (10) connected to the heat retaining casing (4), The plastic pipe (2) is circulated by utilizing the (18) and the discharge line (19), and the circulation of this heating fluid heats the plastic pipe (2).

After the plastic pipe (2) is softened by the heating by the heating fluid and it is possible to draw it out from the drum (3),
The pressurized fluid passes through the supply line (7), the swivel joint (6), the hollow rotating vertical axis (5a), and the connection line (8) in this order from the rear end (end on the drum center side) of the plastic pipe (2) to the inside thereof. And the inside of the plastic pipe (2) is kept under pressure.

The pressure retention inside the plastic pipe (2) is to restore the plastic pipe (2) pulled out under the heat-softened state from the flat tubular shape to the original circular tubular shape. , depending on the softened state, usually held in a pressurized state of 0.1~0.2kg / cm ^2, the pressure exceeding 0.5 kg / cm ^2,
It is not preferable because there is a risk of expansion beyond the tubular restoration.

Thus, the winch (20) installed on the other side of the manhole (1b) while continuously heating the plastic pipe (2) from the outside and applying pressure from the inside (see FIG. 2).
When the plastic pipe (2) is pulled out from the drum (3) through the pulling line (14), the three plastic pipes pulled out from the drum (3) under the softened state. (2) is an inclined heat insulation duct (16) under the parallel state (see FIG. 4 (a)) by the guide of the upper guide roller (21) while restoring the shape from a flat tube to a circular tube by internal pressure.
It passes through the inside and enters the horizontal heat-insulating duct (10), where it reaches the inside of the outlet passage (11) at the front end thereof while being collectively guided by the gathering guide mechanism (9) so as to have a polygonal cross section.

The outlet passage (11) is made of a heat conductive material such as metal, and functions as a cooling means in cooperation with cooling water from the supply device (12) which is rained on the constituent members of the passage (11). Therefore, the collected plastic pipes (2) are cooled and solidified during the passage in the passage (11), and this cooling and solidification is further promoted by the cooling water directly rained in the passage (11), It comes to possess rigidity as a hard plastic material.

Furthermore, since the outlet passage (11) faces the inlet of the pipe (1), the collected plastic pipes (2) ...
Can be inserted from directly in front of the inlet of the outlet passageway (11), and therefore in an aligned state.

Therefore, since the plastic pipe (2) is drawn into the pipe line (1) in a rigid and aligned state, it passes smoothly through the pipe line (1) and has an ultra long span of 200 to 400 m. Regardless of whether it is inserted into the pipeline (1), it can be inserted through the entire length of the pipeline by pulling and pulling the pull line (14), and as shown in FIG. 5, the pipeline (1)
It is possible to form three subdivision conduits (2 ') therein.

According to the construction method of the present invention, as shown in FIG. 6, for example, the plastic pipe (2) is provided under the concentric arrangement of the conduit (1).
By inserting the pipe into the pipe (1), seven subdivided pipes (2 ') can be formed.

In the method of the present invention, it is not always necessary to apply the front conduit (13), and the tip of the plastic pipe (2) is pulled out from the outlet passage (11) of the horizontal heat insulation duct (10) by preliminary operation. It may be directly connected to the connector (15) later.

Further, if the predetermined number of small-diameter plastic pipes (2) are still inserted in the pipe line (1), the inserted state will be somewhat loose, so for the purpose of eliminating looseness,
Part or all of the inserted plastic pipe (2) may be slightly expanded in the radial direction of the pipe by heat and pressure applied from the inside.

As the shafts (1a) and (1b), the case where the existing manhole is used has been described in the embodiment, but the ground may be excavated to form the shaft.

Effect According to the method of the present invention, it is possible to form a subdivided pipe line made of plastic pipe while smoothly inserting and inserting a plurality of small-diameter hard plastic pipes into an existing buried pipe line under a polygonal cross-section assembly. However, such a subdivision pipeline can be formed with a long span of, for example, about 200 to 400 m as one construction length, and the subdivision pipeline can be formed with good work efficiency and at low cost.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a manhole portion on the one hand showing an implementation state of the method of the present invention, FIG. 2 is a schematic explanatory diagram of the manhole portion on the other hand, and FIG. 3 is a preliminary working step of the method of the present invention. Schematic explanatory views, FIGS. 4 (a) to 4 (d) are explanatory views of the principle of the assembly guide mechanism, and FIGS. 5 and 6 are enlarged cross-sectional views showing two examples of the formation state of the subdivided conduits. In the figure, (1) is a pipe line, (2) is a hard plastic pipe, (3) is a winding drum thereof, (4) is a heat retaining casing, (5) is a drum supporting device, and (6) is a swivel joint. , (7) is a supply line, (8) is a connection line,
(9) is a set guide mechanism, (10) is a horizontal heat insulation duct, (1
1) is an outlet passage, (12) is a cooling water supply device, (14) is a towing line, (15) is a connector, (16) is an inclined heat insulation duct,
(17) and (18) are supply lines and (19) are discharge lines.

Claims (1)

[Claims] 1. A method of forming a plurality of small-division pipelines by using a plurality of small-diameter hard plastic pipes in an existing buried pipeline between one vertical shaft and another vertical shaft. I) A plurality of small-diameter hard plastic pipes wound into a roll in a state of being processed into a flat pipe from a circular pipe is installed in the vicinity of one vertical shaft, and in this installed state,
A first step of heating and softening each plastic pipe to a state where it can be pulled out from a roll, ii A pipeline for opening a plurality of the heat-softened plastic pipes into the shaft from the roll while maintaining the heat-softened state. The second step of drawing out toward the front position of the inlet and supplying pressurized fluid into the plastic pipe to restore the pipe withdrawal part from the flat tubular shape to the original circular tubular shape, and iii to the front position of the pipeline inlet A plurality of drawn out circular tubular restored plastic pipes are moved along the extension of the central axis of the pipeline from the front position toward the pipeline inlet while maintaining the heat-softened state. Iv, during the movement along the extension line in the above-mentioned third step, the plurality of plastic pipes are cooled and solidified while gathering in a polygonal cross-section, and then drawn from the pipe inlet to the inside thereof. Nde go, subdivision method in the line space, characterized in that.