JPH07100926B2 - Underdrain drainage pipe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an underdrain drainage pipe used by being buried in a golf course, a wetland, or other ground.

[0002]

2. Description of the Related Art Conventionally, as this type of underdrain drainage pipe, as described in Japanese Utility Model Publication No. 54-27206, a tape-shaped net is spirally formed and its side edges are successively overlapped with each other. Winding to form a resin tube, and a non-woven fabric between the overlapping parts of the net in this resin tube,
Alternatively, there is known a structure in which a filter made of glass fiber or other woven fabric is sandwiched, and reinforcing strips are spirally fused and fixed to the inner and outer circumferences of a resin pipe.

[0003]

Such an underdrain drainage pipe is laid in an underdrain formed under the ground, and filters the muddy water penetrating under the ground by a filter to guide it into the drainage pipe. However, there are various soil types in the buried place of the underdrain drainage pipe, for example, there are various types such as muddy water, clay type, and gravel type, and in the filter made of the above-mentioned non-woven fabric or glass fiber or other woven fabric, It is not suitable for all soil types.

That is, in such a filter, particularly a filter made of a non-woven fabric, the passage resistance of water becomes large because the thickness of the filter is relatively large, and at the same time, it is filtered through the gaps between the fibers caused by the entanglement of the fibers. Since it works, it has too small an aperture to allow fine particles of mud to pass through, and the fine particles remain between the fibers in the surface layer of the filter and accumulate, causing clogging, making them unusable in a short period of time. There was a problem that

Further, since the resin pipe is formed of a net, when the pipe is arranged in the underdrain, the resin pipe is stretched and the filter is broken, and muddy water flows into and accumulates in the drain pipe. There was a problem. Further, a woven fabric coarsely woven by a narrow flat yarn is also used as a filter, but since it is relatively coarse, it may not only pass through sandy soil. However, misalignment causes sand soil to flow in more severely, which makes it unsuitable for use as an underdrain drainage pipe.

Furthermore, a strip tape made of such a woven fabric is spirally wound so that the edge portions overlap each other to form a tubular body, and the tape is formed on the side edge of the outermost layer of the tubular body. When the reinforcing strip is wrapped and the bottom of the reinforcing strip is melted and the reinforcing strip is integrally welded to the tape, the tape is also melted and the strength is reduced, and bending such as during handling or construction of the drainage pipe may occur. There is a problem that it cannot withstand stress or external pressure after construction. It is an object of the present invention to provide an underdrain drainage pipe which can be used for a long period of time without being affected by soil properties and without causing clogging.

[0007]

In order to achieve the above object, the underdrain drainage pipe of the present invention has a plurality of resin yarns 2, 2 stretched in the lengthwise direction, which are arranged vertically and horizontally. A band-shaped filter material 4 having innumerable filtering small holes 3 is formed by welding the intersecting portions, and the band-shaped filter material 4 is spirally wound to form a cylindrical pipe wall 1 and a spiral.
Of adjacent strip-shaped filter materials 4 and 4 wound in a circular pattern
Those having I have been opposed end on a belt-shaped filter material reinforcing strip member 5 made of resin through the low melting point resin adhesive layer 6 than 4 wrapped spiral strip, comprising integrated structure is there.

[0008]

The pipe wall 1 of this underdrain drainage pipe is composed of a band-shaped filter material 4 having innumerable small holes 3 formed by longitudinally and laterally arranged yarns 2, 2 ... Since it is configured, the small thickness is small and the small holes 3 communicate directly between the inner and outer circumferences of the pipe wall 1 so that the passage resistance of water is extremely small and the muddy water in the earth and sand flows quickly and easily. It enables smooth drainage and allows fine particles of mud to pass through together with the mud to eliminate clogging. Further, even if the small holes 3 are closed by gravel, the gravel itself exerts a filtering action and does not reduce the drainage efficiency.

Further, the stretched thread 2 constituting the tube wall 1 has a very high tensile strength, and the tube wall 1 is damaged even if a pulling action occurs on the tube when it is laid in an underdrain. There is no risk of this happening, and the reinforcing strip 5 is wound around the pipe wall 1 in a spiral shape.
The torsional strength and pressure resistance are maintained by this, and the reinforcing strip 5 is spirally wound around the side edge of the strip-shaped filter material 4 forming the tube wall 1 via the low melting point resin adhesive layer 6. ,
Since they are integrated, the belt-shaped filter material 4 can be firmly fixed to each other without melting, and the reinforcing strip 5 can be thin and thick to increase the effective drainage area by the split cloth. In addition, the pressure resistance is further improved, and therefore, the above-mentioned good drainage action can be maintained for a long period of time.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.
Reference numeral 1 denotes a cylindrical tube wall, which has a large number of narrow flat resin yarns 2, 2 ... 2 stretched in the length direction, such as polyethylene.
The flat strip-shaped filter material 4 having a large number of square filtration small holes 3, 3, ... The filter material 4 is spirally wound around a molding shaft (not shown), and one end surface of the filter material previously wound is overlapped with the other end surface of the same filter material to be wound next, or close to the one end surface. It is formed by winding in a butt state.

As the flat belt-shaped filter material 4 constituting the tube wall 1 as described above, a stretched film such as a high density polyethylene film having a thickness of about 0.07 to 0.15 mm is provided in a large number by making fine cracks in the stretching direction. 2 of the split films formed on the parallel yarns 2, 2 ... 2 of
It may be formed by laminating one or more sheets in a direction perpendicular to each other and integrally welding, or using a flat narrow width (about 2 mm) resin yarn 2 stretched in the length direction. Then, the flat belt-like filter material 4 having a large number of square-shaped filtering small holes 3, 3, ...

The filtering small hole 3 of the filter material 4 is 0.3
It is formed to have a constant size in the range of up to 3 mm, and the size can be easily set by the arrangement interval of the narrow flat resin yarns 2, 2. In the outer peripheral surface of the tube wall 1, 5 is a superimposition of one side edge portion of the filter material 4 which is spirally wound once, and the other side edge portion of the filter material 4 which is wound once, or on the abutting portion. Is a thick strip-shaped reinforcing strip formed by spirally winding and integrating it through a resin adhesive layer 6 having a melting point lower than that of the filter material 4, and is made of a hard polyethylene resin.

The resin adhesive layer 6 for adhering the reinforcing strips 5 on the side edges of the filter material 4 is made of a narrow low melting point synthetic resin tape such as soft polyethylene which melts at a temperature lower than that of the filter material 4. , This tape is a filter material 4
After being spirally wound around the overlapping or abutting side edges of the tape, the strip-shaped reinforcing strips 5 made of the above-mentioned hard polyethylene resin or the like having the same width as the tape are overlapped and wound in a spiral shape. This tape is welded to the bottom surface of the reinforcing strip 5 by heating and melting, and the molten resin of the tape is filled in the small holes 3 of the filter material 4 and solidified to integrally form the pipe wall 1 and the reinforcing strip 5. It is glued.

The adhesive layer 6 formed by melting and solidifying the tape is also provided on the inner surface of the side edge of the filter material 4 as shown in FIG. The inner reinforcing strip 7 may be fixedly attached to the inner peripheral surface of 1. or,
When the pipe wall 1 is formed by the strip-shaped filter material 4, the strip-shaped filter material 4 having a width that is at least twice the spiral pitch of the reinforcing strips 5 is spiraled so that the opposite end faces thereof are overlapped or abutted. The tubular wall 1 may be wound in a circular shape to form a cylindrical wall 1, and the reinforcing strip 5 may be wound around the widthwise intermediate portion of the strip-shaped filter material 4.

Further, the pipe wall 1 may be formed by stacking two or more strip-shaped filter materials 4 together, or by using two or more wide strip-shaped filter materials 4 as shown in FIG. As shown in Fig. 4, the reinforcing strips 5 are stacked in such a manner that they are displaced by the spiral pitch dimension, and several layers of the filter materials 4 and 4 are stacked.
You may form the tube wall 1 which consists of. In such a case, a reinforcing strip may be integrally interposed between the filter materials 4 and 4 that are superposed on the inside and outside.

The underdrain drainage pipe constructed as described above is installed by being drawn into the underdrain in the ground, and the water in the earth and sand that permeates below the ground is flowed into the pipe from the large number of small filtration holes 3 of the filter material 4. . At that time, the filtering small holes 3 of the filter material 4 are
Since a large number of narrow flat resin yarns 2, 2 ... 2 are arranged at regular small intervals in the vertical and horizontal directions and the intersections thereof are welded, they spread or contract. There is no such thing, and a uniform size and shape are always maintained to perform a uniform filtering action.
Further, since the narrow flat resin yarn 2 is stretched in the length direction, the pressure-resistant tension of the pipe main body 1 is increased, and the shape and the workability are excellent together with the reinforcing strip 5. .

[0017]

As described above, according to the underdrain drainage pipe of the present invention, the pipe wall 1 has the yarns 2, 2, ...
Since 2 is composed of a band-shaped filter material 4 having innumerable filtering small holes 3 arranged vertically and horizontally, the filtering small holes 3 are directly communicated between the inner and outer peripheral surfaces of the pipe wall 1. As a result, the passage resistance of water is extremely small, and muddy water other than gravel in the earth and sand can be quickly and easily circulated through the small holes 3 into the pipe. The drainage efficiency is remarkably improved as compared with a drainage pipe made of, etc., and fine particles of mud can be passed through the small holes 3 together with mudwater to eliminate clogging.
Despite the long-term use, there is almost no decrease in drainage capacity. Further, even if the small holes 3 are closed by gravel, the gravel itself exerts a filtering action, so there is almost no risk of reducing the drainage efficiency.

Furthermore, since the intersecting portions of the yarns 2 and 2 arranged in the vertical and horizontal directions are welded, a large number of filtration small holes 3 formed by these yarns 2 and 2 have a substantially constant shape and size. In this way, it is possible to prevent the occurrence of misalignment by being held at a high level, and to obtain a uniform filtering action over the entire length of the drainage pipe. Further, since the filter material 4 forming the innumerable filtration small holes 3 is composed of the drawn yarns 2 and 2, the tensile strength is very high, and when the filter material 4 is pulled into the underdrain or the like, it is stretched on the pipe. Even if the pulling action occurs, the pipe wall 1 is unlikely to be damaged, and the reinforcement strip 5 is spirally wound around the outer periphery of the pipe wall 1, so that the reinforcement strip 5 is sufficiently twisted. The strength and pressure resistance can be maintained, and the shape retention of the tube wall 1 is improved, which makes it easier to handle and improves workability.

Further, the resin yarns 2, 2 are crossed vertically and horizontally.
And welding the intersections
The band-shaped filter material 4 having the filtering small holes 3 is wound in a spiral shape.
In the state where the tube wall 1 is turned to form the tube wall 1, the adjacent strips are
The opposite ends of the sheet-shaped filters 4 and 4 are overlapped.
And the strip-shaped filter material on the overlapped side edges.
Is the resin reinforcing strip 5 wound around and integrated with the spiral strip through the resin adhesive layer 6 having a melting point lower than 4 ?
Before the band-shaped filter material 4 is melted.
The resin adhesive layer 6 having a lower melting point than the material 4 melts
The molten resin adhesive layer 6 is overlapped with the band-shaped filter material 4.
In the state where it is filled and solidified in the filtering small hole 3 at the side end
Therefore, the strength of the band-shaped filter material 4 is reduced.
Without using the resin adhesive layer 6
Of the underdrain drainage pipe, which is firmly bonded and integrated with the reinforcement strip 5.
It has a structure that is durable and can withstand long-term use.
It is possible to provide an underdrain drainage pipe.

[Brief description of drawings]

FIG. 1 is a simplified side view,

2 is a partially enlarged vertical side view,

FIG. 3 is a partially enlarged vertical side view showing another embodiment,

FIG. 4 is a partially enlarged vertical side view showing still another embodiment.

FIG. 5 is a partial plan view of a filter material.

[Explanation of symbols]

 1 Pipe Wall 2 Yarn 3 Filter Small Hole 4 Filter Material 5 Reinforcing Strip 6 Low Melting Adhesive Layer

Claims (1)

[Claims] 1. A belt-shaped filter material 4 having a large number of filtration small holes 3 by arranging a large number of resin yarns 2, 2 stretched in the lengthwise direction in the vertical and horizontal directions and welding their intersecting portions. The strip-shaped filter material 4 is spirally wound to form the cylindrical tube wall 1 and is spirally wound.
Adjacent strip-shaped filter materials 4 and 4 overlapped with each other
A resin-made reinforcing strip 5 is spirally wound around the side end portion through a resin adhesive layer 6 having a melting point lower than that of the strip-shaped filter material 4 ,
An underdrain drainage pipe characterized by being integrated.