JPS6112047B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel synthetic resin underdrain drain pipe.

Underdrain drainage pipes are subject to large earth pressures, so they must have excellent earth pressure resistance, but as shown in Figure 6, a small water permeable hole b in an extremely thick pipe a...
If a general underdrain drainage pipe with a structure with many holes is manufactured from synthetic resin, it requires a large amount of resin, which is disadvantageous from an economic and resource saving perspective, and it is also heavy and difficult to hold. It was also at a disadvantage in terms of luck. Not only that, but such drainage pipe has water permeability hole b...
Excessive drilling reduces the earth pressure resistance, which naturally limits the permeable aperture ratio, and is therefore unsatisfactory in terms of water absorption efficiency.

Focusing on this point, various synthetic resin underdrain drain pipes have recently been developed, but the reality is that there are hardly any that are fully satisfactory.

In view of the above circumstances, the present invention has a pipe wall that has a three-dimensional structure, is thick, has high earth pressure resistance, and has low water absorption efficiency, although the amount of resin used is relatively small and it is lightweight. It is an object of the present invention to provide a synthetic resin underdrain drain pipe that is excellent in several respects.

The underdrain drainage pipe of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a schematic vertical cross-sectional view of an embodiment of the present invention, and Fig. 2 is a schematic cross-sectional view of the same embodiment, with the illustrations The present invention provides a net cylindrical frame 1 as shown in FIG.
A plurality of thick wave yarns 1 made of synthetic resin are partially fused to each other and run in the axial direction while meandering in the circumferential direction.
This invention relates to an underdrain drain pipe, which is formed of a frame 1 and a large number of thin synthetic resin threads 2 running in the axial direction around the outer periphery of the frame 1 are fused.

The wavy threads 11 constituting the mesh tubular frame 1 are made of hard synthetic resin such as polypropylene or high-density polyethylene (preferably 1.5 to 5 times, especially 2 to 3 times
In this example, eight wavy yarns 11 are arranged alternately on the inside and outside, each meandering in the circumferential direction and axially. The wave yarns 11 are partially fused to each other where their peaks and valleys overlap. In this embodiment, the wave yarn 11...
The pressure-resistant strength of the frame 1 is designed to be further increased by making it an extremely thick thread with a substantially oval cross section that is long in the diametrical direction of the drain pipe, and by setting the wavelength l of the wavy threads 11 to be small. To give a specific example of a suitable frame 1, for example, a frame suitable for obtaining an underdrain drainage pipe with an outer diameter of about 10 to 15 cm is:
The number of wave threads 11 is 6 to 16, and the thickness is about the major axis.
0.5 to 1.5 cm, wavelength l is approximately 0.5 to 3.5 cm, amplitude is approximately 0.5
Examples include those set within the range of ~4 cm. An underdrain drain pipe using such a frame has a flattening strength (20% deformation) of at least 1 t or more, preferably 2 t or more per meter, and is sufficiently durable for civil engineering applications.

Note that the net cylindrical frame 1 of this embodiment has wavy threads 1
1... are made to overlap at their peaks and troughs, but for example, as shown in Fig. 3, the wave yarns 11... are fused by increasing the degree of overlap so that they overlap at places other than the crests and troughs. Alternatively, as shown in FIG. 4, the wave yarns 11 may be fused so that the crests and troughs are brought into contact with each other in the circumferential direction without overlapping each other.

A large number of thin threads 2 of synthetic resin running in the axial direction are fused to the outer periphery of the net cylindrical frame 1 as described above, thereby creating waves between the thin threads 2 and the inside and outside of the frame 1. A very thick tube wall A having a partially triple layered structure is formed by the threads 11. This tube wall A has a water permeability gap 3 which is sufficient to prevent the passage of the earth and sand grains formed between the fine threads 2 on the surface, and a wave thread 1 on the inside.
1... has a high water permeable aperture ratio with large water permeable gaps 3' formed between the thin threads 2. In particular, in this embodiment, by irregularly sliding the thin threads 2... The water permeable opening ratio is further improved by forming more water permeable gaps 3 than when they are provided linearly. However, in a straight line, thin thread 2...
Of course, it is also possible to provide a drain pipe, and even in that case, a water permeable aperture ratio higher than that of the conventional drain pipe as shown in FIG. 6 can be obtained. Such thin threads 2 may be made of either the same hard synthetic resin as the mesh cylindrical frame 1 described above, or other semi-hard or relatively soft synthetic resin; From the viewpoint of increasing the tensile strength, semi-hard or relatively soft synthetic resin fine threads having excellent tensile strength and shock absorbing properties are more preferably employed. There are no particular restrictions on the thickness or number of such thin threads 2, but for example, if the outer diameter is 10
In the case of an underdrain drainage pipe of about 15 cm, it is appropriate to set the diameter of the thin threads to about 0.1 to 0.5 cm and the number of threads in the range of about 50 to 150. In this embodiment, the thin threads 2 are provided in a single layer on the outer periphery of the net cylindrical frame 1, but they may be provided in double or triple layers depending on the case.

The above-mentioned culvert drainage pipe is made by winding a plurality of thick threads of synthetic resin in the circumferential direction from double rotating dies x and y, which rotate inside and outside while changing the direction of rotation from side to side and reversing each other, as shown in Fig. 5. These wavy threads 11 are partially fused where they overlap to form a net cylindrical frame 1 by continuous extrusion. To manufacture easily and with high efficiency by extruding a large number of thin threads 2 of synthetic resin along the frame 1 from a ring-shaped die z, and fusing the thin threads 2 to the frame 1. I can do it. In this case, if the reversing speed of the rotary die is kept constant and the take-up speed is slower than the extrusion speed of the mesh cylindrical frame 1 and the fine yarn 2..., the wavelength l of the wave yarn 11 of the mesh cylindrical frame 1 can be adjusted to a smaller value. , plus fine thread 2...
It can also be bent.

The above is the basic configuration of the present invention, but furthermore,
If necessary, attach an appropriate synthetic resin film-like material 4 or the like as shown in the illustration to the water surface inside the drain pipe, or
Alternatively, it is desirable to use other appropriate means to reduce the roughness coefficient of the water surface inside the drain pipe and make it smooth so that the water absorbed into the drain pipe can flow smoothly.

As can be understood from the above explanation, in the underdrain drainage pipe of the present invention, a three-dimensional three-dimensional structure is partially formed by the wave yarns 11 constituting the mesh tubular frame 1 and the fine yarns 2 on the surface. Since the extremely thick pipe wall A is formed, a large earth pressure resistance strength can be obtained even though the amount of resin used is small. This effect is particularly noticeable when the wavy yarns 11 are made of extremely thick yarns with a substantially oval cross section that are long in the diametrical direction of the drain pipe, and the wavelength l of the wavy yarns 11 is set to be small, as in the embodiment. Become something. In addition, if the thin threads 2 on the surface are made of a semi-hard or relatively soft synthetic resin as described above, the impact resistance will be improved and the drain pipe will be extremely durable. In addition, in the drain pipe of the present invention, the wave thread 11
..., and the gaps formed between all the threads of the thin threads 2... become water permeable gaps 3... and 3'..., so the water permeable aperture ratio of the tube wall A is high, and the small gaps between the thin threads 2... on the surface The water that has entered from the water permeation gap 3... is the wave thread 11...
Since the water is quickly attracted to the large water permeable gaps 3' between the pipes and flows into the drain pipe, the water absorption efficiency is greatly improved. This efficiency is based on the thin threads 2 on the surface as in the example.
This becomes even more noticeable when the water-permeable aperture ratio is increased by bending the surface. Furthermore, when the flowing water surface is made smooth by means such as pasting the film-like material 4 on the inner flowing water surface as in the previously described embodiments, there is an additional effect that the absorbed moisture flows smoothly. It has a great effect.

As described above, the underdrain drain pipe of the present invention is useful because it has a high earth pressure strength despite the small amount of resin used, and has a large water permeable aperture ratio and good water absorption efficiency.

[Brief explanation of the drawing]

Fig. 1 is a schematic partial cross-sectional view of one embodiment of the culvert drainage pipe of the present invention, Fig. 2 is a schematic cross-sectional view of the same embodiment, and Figs. 3 and 4 are other examples of the mesh tubular frame. FIG. 5 is an explanatory view of an example of a manufacturing method of the underdrain drain pipe of the present invention, and FIG. 6 is a partial perspective view of a conventional underdrain drain pipe. Explanation of main symbols in the drawings: 1...Mesh cylindrical frame, 11...Wave yarn, 2...Thin thread, 3, 3'...Water gap, 4...Film-like material, A...Pipe wall, l ……
Wavelength, W...width.

Claims (1)

[Claims] 1 A net cylindrical frame 1 is formed of a plurality of thick wave yarns 11 made of synthetic resin that are partially fused to each other and run in the axial direction while meandering in the circumferential direction. An underdrain drain pipe made by fusing together many running thin synthetic resin threads 2.