JPS5845337B2 - Underdrain drainage pipe manufacturing method and manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a synthetic resin underdrain drain pipe that is buried in the soil to collect and drain excess water in the soil.

Conventionally, synthetic resin underdrain drainage pipes have been used, such as vinyl chloride pipes or corrugated pipes with holes drilled in them, or mesh pipes. There are disadvantages such as a decrease in strength against pressure and a decrease in water collection efficiency if the number of holes is small. Although there is no problem in terms of water collection efficiency with the latter type of mesh pipe, sediment can pass through the mesh. The disadvantage is that drainage efficiency decreases as water flows in.

In addition, double-walled pipes, which are coated with finely meshed mesh pipes, are also used to prevent the inflow of earth and sand, but these have drawbacks such as not only increasing the number of steps but also requiring high equipment and raw material costs.

The present invention forms a fine mesh by cross-welding a large number of filaments and spiral filaments in the generatrix direction of the pipe, and at the same time fuses and integrates thick spiral filaments to ensure strength against earth pressure. , an underdrain drain pipe that eliminates the drawbacks of the conventional products mentioned above.
The purpose is to provide a method and apparatus for continuous and efficient production.

The details of the present invention will be explained below using embodiments shown in the drawings.

FIG. 1 shows an embodiment of the mold used in the present invention, in which an inner cylinder 2 is fitted and fixed concentrically to an outer cylinder 1, and a spider 4 and a ring 3 are fixed concentrically to the upper part of the outer cylinder 1. ing.

A cylindrical space surrounded by the upper outer peripheral wall of the inner cylinder 2 and the upper inner peripheral wall of the ring 3 is partitioned by the upper part 4a of the spider 4, and two concentric spaces are provided adjacent to the inside and outside of the spider upper part 4a. An annular nozzle 9a is formed between the outer peripheral wall of the inner cylinder 2 and the inner peripheral wall of the spider upper part 4a, and an outer annular nozzle 9c is formed between the inner peripheral wall of the ring 3 and the outer peripheral wall of the spider upper part 4a. are doing.

The spider upper part 4a has a comb-teeth shape, and has a large number of circularly arranged grooves at equal intervals forming a linear nozzle 9b.

A hollow rotating shaft 5 is inserted into the inner cylinder 2 via a bearing 6, and the upper end of the rotating shaft 5 blocks a part of the outlet of the inner annular nozzle 9a in the circumferential direction. A cutting tool γ is used to cut off the resin coming out from the resin, and a rotating shaft and a driving sprocket wheel 8 are respectively fixed to the lower end.

A sprocket wheel 10 is attached to the ring 3 via a bearing 11, and a sprocket wheel 10 has a cutter 12 fixed to the upper end thereof for blocking a part of the outlet of the outer annular nozzle 9c in the circumferential direction and cutting off the resin discharged from the outer annular nozzle 9c. The cutter γ and the cutter 12 are rotatably mounted, and the cutter γ and the cutter 12 rotate independently and concentrically with the inner and outer annular nozzles 9a and 9c.

A heating means is provided on the outer periphery of the mold, but is not shown.

Next, the operation of the present invention will be described.

The molten resin supplied from the connection part 13 with the extruder is uniformly distributed in the circumferential direction in the resin reservoir 14, and the resin passage 15
It is divided into three nozzles 9 a t 9 b t 9 c and extruded.

Between the comb teeth of the spider upper part 4a, that is, the linear nozzle 9b
The resin extruded from the resin is drawn upward and becomes a large number of filaments 16 in the generatrix direction.

The resin extruded from the outer annular nozzle 9c is separated from the resin inside the slit by the rotation of the cutter 12 that blocks a part of the nozzle outlet in the circumferential direction, and becomes a spiral filament 17.
An integral tubular network is formed by fusion bonding with the generatrix direction filaments 16 on the inside.

The resin extruded from the inner annular nozzle 9a is similarly separated as the cutter 7 rotates to form a spiral filament 18, which is fused and integrated with the filament 16 on the outside, and is molded in this manner. At this time, by making the rotation of the cutter 7 slower than the rotational speed of the cutter 12, the spiral filaments 18 become thicker, and as a result, a reticular tube having a shape in which a fine mesh is reinforced with thick spiral filaments is obtained.

For example, the rotation speed of the cutter 12 was made three times the speed of the cutter 7, and the slit gap of the annular nozzle was adjusted so that the amount of resin extruded from the inner annular nozzle 9a was twice the amount of resin from the outer annular nozzle 9c. In this case, the interval 1 between the spiral filaments 17 is 1/3 of the interval between the spiral filaments 18, giving a fine mesh, and at the same time, the cross-sectional area of the spiral filaments 18 is twice as large as the amount of extruded resin. The cross-sectional area of the filament 17 is six times larger, and a thick filament is created.

In the above embodiment, a fine mesh is created by adjusting the slit gap of the annular nozzle and increasing the rotational speed of the blade 12, but a fine mesh can also be obtained by increasing the number of blades fixed to the sprocket 101.

For example, when a set of three blades 12 are installed at positions that equally divide the circumference, three spiral filaments are formed at the same time, and the interval I between the filaments 17 is equal to the interval between the spiral filaments 18. 1/
It becomes 3.

The spacing m between the filaments 16 in the generatrix direction can be freely changed by changing the spacing between the comb teeth of the spider upper part 4a, but for general use it is preferable to make it approximately the same as the spacing I between the spiral filaments 1γ.

Further, although an example has been described in which the reinforcing thick spiral filaments 18 are formed on the inside of the tube, they may be formed on the outside of the tube.

As described above, according to the present invention, one of the two spiral filaments □ formed by two independently rotating blades is cross-fused with a large number of generatrix direction filaments to form a fine mesh. , and the other one can be made into a thick spiral wire, so there is no drop in drainage efficiency due to the inflow of earth and sand, and it is possible to manufacture an underdrain drainage pipe with excellent strength against earth pressure in one process. be.

Furthermore, all the filaments forming the underdrain drainage pipe according to the present invention are extruded from fixed nozzles and no rotating nozzles are used, which not only simplifies the structure of the mold but also has the advantage of being suitable for high-speed continuous production. be.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a mold according to an embodiment of the present invention, and FIG. 2 is a partial perspective view of the vicinity of the nozzle outlet. 9a... Inner annular nozzle, 9b... Linear nozzle, 9c... Outer annular nozzle, 7, 12
... cutlery, 16 ... wires in the generatrix direction,
17,18...Spiral striations.

Claims (1)

[Scope of Claims] 1. A comb-like spider having a large number of linear nozzles arranged in a circular manner. From the inner and outer annular nozzles, two blades (or two sets of blades) are positioned so as to partially block the exit of the nozzle in the circumferential direction, and which rotate independently concentrically with the inner and outer annular nozzles. Separate the extruded resin and make two inner and outer pieces (
Alternatively, manufacturing an underdrain drainage pipe characterized in that two sets of spiral filaments are formed and at the same time the spiral filaments are cross-fused to the filaments in the generatrix direction of the pipe extruded from the linear nozzle. Method. 2. A comb-shaped spider upper part having a large number of linear nozzles arranged in a circular manner, inner and outer annular nozzles provided concentrically adjacent to the inside and outside of the spider upper part, and a circumferential direction of the outlet of the inner and outer annular nozzles. Two (or two sets of) cutters are provided, each of which blocks off a portion of the inner and outer annular nozzles, and rotates independently and concentrically with the inner and outer annular nozzles, and the resin extruded from the inner and outer annular nozzles is separated by the cutters. An apparatus for manufacturing an underdrain drain pipe, characterized in that a spiral filament is cross-fused with a filament in the generatrix direction of the pipe extruded from a linear nozzle.