JPS6144161B2 - - Google Patents

Description

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

Ideally, underdrain drainage pipes should have both high earth pressure resistance and high water permeability opening ratio. However, earth pressure resistance and water permeability aperture ratio are generally in an inversely proportional relationship, and when one is superior, the other is inferior. For this reason, the reality is that an excellent underdrain drainage pipe that combines both has not yet been developed.

In view of the above-mentioned circumstances, the present invention has been made to provide a synthetic resin underdrain drainage pipe which has a good water permeability opening ratio and is particularly excellent in earth pressure resistance. Inside the bellows-tube drain pipe body, which is constructed by layering wavy warp threads of synthetic resin in the diameter direction and partially fusing them together, the void in the convex large diameter part of the main body is not blocked. The present invention relates to an underdrain drain pipe comprising a thick annular weft of synthetic resin fused to each concave small diameter portion of the main body.

Hereinafter, the underdrain drain pipe of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a longitudinal cross-sectional view of one embodiment of the present invention, and Fig. 2 is a cross-sectional view of the same, in which 1 shows a large number of wavy warp threads 2 of synthetic resin layered in the diameter direction. The drain pipe main body 3 is in the shape of a bellows tube and is partially fused to each other, and numerals 3 are thick annular wefts of synthetic resin formed at intervals on the inside of the main body 1.

Wavy warp threads 2 constituting the drain pipe main body 1...
They are all curved in the axial direction while undulating and sliding approximately in the diametrical direction of the drain pipe body 1 with substantial regularity, and in this embodiment, they are provided twice inside and outside. . That is, the inner wavy warp threads are arranged and fused rather densely around the weft thread 3 with a gap smaller than the thread diameter of the warp thread at the welded part with the annular weft thread 3, and the outer wavy warp threads are fused together. The warp threads are arranged alternately between the inner wavy warp threads and are fused to these inner warp threads or annular weft threads. Of course, the wavy warp yarns 2 can be provided in three or more layers. Inside the concave small diameter portion 11 of the bellows cylindrical drain pipe main body 1,
An annular weft thread 3 is arranged, respectively.
The wavy warp threads 2 are densely fused together around the annular weft thread 3. This circular weft thread 3...... is the warp thread 2...
During the formation of the drain pipe main body 1 by extrusion of..., the warp threads 2...... were intermittently extruded from the same die while maintaining a constant interval through several auxiliary threads 21... It is a thick thread with a cross-sectional area about 5 to 30 times that of ...... Therefore, this concave curved small diameter portion 11
In particular, the circular weft thread 3 and the wavy warp thread 2...
The welded portions with ... are almost in a knotted state, but other parts, especially the convex curved large diameter portion 12 of the drain pipe main body 1 ......, the adjacent wavy warp threads 2
......A considerable amount of voids are formed between them.

The convex curved large diameter portion 12 of the drain pipe main body 1 referred to in this specification is a concept that refers to the outer half when the peripheral wall of the drain pipe main body is divided into approximately two equal parts, as shown in FIG. The concave small diameter portion 11 is a concept that refers to the inner half. Therefore, in an extreme case, the annular weft 3 fused to the inside of the concave curved small diameter section 11 may be fused to the inside of the convex curved large diameter section 12, as shown in FIG.
This also includes a case where the position of the fusion is shifted to the vicinity of the equal dividing line l.

Such an underdrain drain pipe can be regarded as a drain pipe having a large wall thickness corresponding to the amplitude w of the wavy warp threads 2.
As shown in the figure, the convex curved large diameter portion 12 of the drain pipe main body 1
The earth pressure P applied to ......... the wavy warp threads 2 that undulate and slide with substantial regularity in the diameter direction...
The wavy warp threads 2... are stopped by respective annular weft threads 3...... which are almost evenly distributed along...
It has extremely high earth pressure resistance because it does not cause large stress peaks locally.
In addition, when the drain pipe main body 1 is configured in an accordion tube shape by the wavy warp threads 2, a void 4 is created in the convex curved large diameter portion 12 as described above. is formed and the surface area of the drain pipe main body 1 increases, so the water permeation opening area increases and the water absorption rate increases.

In addition, since the warp yarns 2 are layered in multiple layers in the diameter direction, the drain pipe main body 1 is composed of an extremely large number of warp yarns 2.
Coupled with the above-mentioned effect due to the up-and-down sliding of the warp yarns 2, the earth pressure resistance strength is further increased without reducing the water absorption rate. Moreover, if the outer wavy warp yarns are arranged alternately between the inner wavy warp yarns as in the case of the embodiment, the intrusion of dirt particles into the inside of the drain pipe main body 1 is prevented, and only moisture is allowed to pass through. The so-called filter effect is improved. This filter effect becomes even more remarkable as the wavy warp threads 2 are alternately arranged in triple or quadruple layers as described above.

As mentioned above, the underdrain drain pipe of the present invention is constructed by bending the wavy warp threads 2 constituting the drain pipe main body 1 with substantial regularity in the diameter direction. One major feature is that the warp is simply extruded from the die at high speed,
Simply bending the warp by taking it up at a low speed will cause the warp to wind and bend randomly.
It is completely impossible to produce the regular undulating sliding in the radial direction as in the present invention, and therefore such a device cannot be expected to have the same effect as the present invention. As mentioned above, such regular undulations and sliding in the diameter direction occur when the drain pipe main body 1 is formed by extruding the warp yarns 2 from a die, and the annular weft yarns 3 are extruded from the same die at a constant interval. ... is intermittently extruded and fused with the warp thread 2...... to prevent the warp thread 2...... from being disturbed, while the warp thread 2...
This is achieved by increasing the extrusion speed and slowing down the withdrawal speed.
In this way, the annular weft thread 3 does not merely function as a rim material to increase strength, but also plays an important role in the regular ups and downs of the warp thread 2. This is another major feature of the present invention. By making the extrusion interval of the annular weft yarns 3 constant, the pitch and amplitude of the wavy warp yarns 2 can be kept constant, and the earth pressure resistance and substantial wall thickness can be kept constant. By adjusting the extrusion interval of the annular weft threads 3, the earth pressure resistance can be improved substantially while keeping the number of warp threads 2 constant. It also becomes possible to adjust the target wall thickness and water permeation opening area. Note that the cross-sectional shape of the drain pipe is not limited to only the circular shape of the embodiment.
Of course, it is possible to have any desired shape, such as a triangle, square, or semicircle, and the same effect can be obtained with any of them.

As mentioned above, the underdrain drainage pipe of the present invention has a substantial wall thickness, a good water permeability opening ratio, and especially an extremely high earth pressure resistance strength, and furthermore, it is easy to adjust the wall thickness, earth pressure resistance strength, water permeation opening ratio, etc. In addition to being easy to use, since it is a synthetic resin product, it is lightweight and can be manufactured at low cost, making it extremely useful.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, Fig. 2 is a partial cross-sectional view of the same embodiment, Fig. 3 is a schematic diagram for explaining the dispersion state of earth pressure, and Fig. 4 is a diagram of the present invention. FIG. 3 is a partial schematic diagram showing another embodiment of the present invention. (Explanation of symbols in drawings), 1... Drain pipe body, 1
1...Concave curved small diameter part, 12...Convex curved large diameter part, 2...
Wavy warp, 21... Auxiliary thread, 3... Circular weft, 4
... air gap, P ... earth pressure, w ... amplitude.

Claims (1)

[Claims] 1 Inside a bellows-shaped drain pipe body, which is constructed by layering a large number of wavy warps of synthetic resin in the diametrical direction and partially fusing each other, there is a convex part on the inside of the main body. An underdrain drain pipe comprising a thick synthetic resin annular weft fused to each concave curved small diameter section of the main body so as not to block the gap in the curved large diameter section.