JPS584614B2 - Method for manufacturing highly flexible underdrain drainage pipes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an underdrain drainage pipe in which the wall surface is made uneven to give flexibility and a large number of through holes are formed in the concave portion. The aim is to efficiently and continuously manufacture good quality underdrain drainage pipes that do not cause any problems. Some underdrain drainage pipes utilize a corrugated hose with a bellows-shaped wall and have a through hole formed in a part of the concave portion of the hose wall.

This culvert drainage pipe uses a corrugated hose manufacturing device with a set of caterpillars, and is equipped with a blade body having a plurality of scratching blades formed on its circumferential surface, which is located on the molding side of the device and inside the molded hose. The corrugated hose is manufactured by scraping a portion of the concave portion of the corrugated hose continuously molded by the manufacturing apparatus using the scraping blade of the blade to form a through hole.

However, with the above-mentioned lucky manufacturing method, the through holes are formed by scratching, which causes stress to concentrate in the through hole area, causing stress when handling the underdrain drainage pipe and when buried in the soil. When external pressure is applied to the pipe, stress cracks occur in the through-hole portion, resulting in a defective product, or the pipe has a defect that prevents it from functioning satisfactorily as an underdrain drainage pipe.

Furthermore, in the above method, if a highly viscous polyethylene resin or the like is used as the pipe material, it becomes difficult to form a through hole using the scratching blade of the blade. Hard vinyl chloride, which can be molded, is mainly used, but when making underdrain drain pipes with this resin, there is a problem that it has poor cold resistance and is prone to cracking.

The present invention was invented to solve the above problems.
Highly flexible without causing stress cracks,
Moreover, the present invention aims to provide a method for manufacturing an underdrain drain pipe that can be freely selected from any material.

Next, the present invention will be explained with reference to the embodiments shown in the figures.
In the figure, reference numeral 1 denotes a support body for a molded shaft attached to a mounting base 2. A cylindrical magnet 4 is inserted onto the support shaft 3, and a fixing nut is attached to the threaded end 3a of the shaft 3. The magnet 4 is fixed by screwing 5, and the support 1 is rotatably driven by a pulley 6 provided on the side of the mounting base 2.

At this time, as the magnet 4, ferrite, alnico, or the like is used.

Reference numeral 7 denotes a forming roller guide tool having a cylindrical forming shaft and made of a non-magnetic material such as plastic or brass, which is inserted onto the magnet 4 of the support 1, and the base end of the tool 7 is connected to the mounting 8'2. The other free end side is supported on the nut 5 via a bearing 8, and is held in an independent state without rotating together with the support body 1.

Therefore, the guide tool 7 has a plurality of opening windows 9 arranged in a row with appropriate inclination angles in the longitudinal direction.
In other words, when looking at the rows as a whole, they are arranged in a twisted state so as to rotate on the guide tool 7, and moreover, the rows of open windows are arranged in a plurality of rows at equal intervals in the circumferential direction of the guide tool 7. ing.

Each opening window 9 is provided with a forming roller 1 having irregularities 10a and IQb formed on its circumferential surface as shown in an enlarged view in FIG.
0 are arranged respectively, and each roller 10 is connected to the opening window 9.
Inside, a portion of the outer periphery of the uneven portions 10a and 10b protrudes outside the window 9, and a portion of the outer periphery is attracted and held by the magnet 4 of the support 1.

At this time, each forming roller 10 has its uneven portion 1Oa,
10b are arranged to draw a spiral locus in the circumferential direction.

In the figure, reference numeral 11 denotes an extrusion molding machine, and at the extrusion tip of the machine 11, a thin strip extrusion port 12 with a concave central portion is formed as shown in FIG. Curved a. The belt-shaped body b is continuously extruded, and this belt-shaped body b is supplied onto each forming roller 10 of the above-mentioned forming shaft in an uncured state.

As shown in FIG. 2, a cutter 13 is rotatably disposed near the extrusion port 12 of the molding machine 11 in order to cut the curved portion a of the extruded strip b and make a cut C in the portion a. There is.

This extruded strip b is supplied under tension to the forming roller 10 of the forming shaft, that is, in a drawn-down state, whereby the cut C formed in the strip b is gradually extended, and finally, A substantially circular through hole d is formed.

In addition, when forming the through hole d in the strip b, not only the rotary cutter 1.3 is used as described above, but also a cutter that moves back and forth intermittently toward the strip b, or only a part of the extrusion port 12 is used. It is possible to use a resistor that temporarily closes the closed part and opens the closed part, or other resistors that can substantially form an opening in the band-shaped body, and when using these, the band-shaped body It is not necessary to form the curved portion a at b.

Further, the through-hole d of the band-shaped body b may have any shape other than a perfect circle, such as a square.

However, when the support body 1 is rotated via the pulley 6, the magnets 4 of the support body 1 are also rotated, so that each molding held by the magnets 4 in each opening window 9 of the guide tool 7 is rotated. The rollers 10 are rotated in the opposite direction to the magnet 4 at the same speed.

Therefore, as shown in FIGS. 1 and 3, a strip b is extruded from an extrusion molding machine 11, and when the strip b is in an uncured state, a through hole d is formed with a cutter 13, and the through hole d is inserted into the forming roller on the forming shaft. When the strip b is fed from the rotation rear side of the roller 10, the strip b is wound around the outer periphery of the forming shaft by each roller 10, and since each roller 10 is held in an inclined position by each opening window 9 of the guide tool 7 during the rotation, the strip b is body b
is given a predetermined advance angle.

Therefore, the strips b are wound spirally around the outer periphery of the forming shaft, and since the strips b are in an uncured state, they are sequentially welded on top of the previously wound ones.

By the way, the forming roller 10 has an uneven portion 10a on the circumferential surface.
, 10b are formed, so when the strip b is fed so that its through hole d is located in the recess 10a of the roller 10, the strip b has the uneven parts 10a, 10 of the roller 10.
b, the same shape of unevenness is formed along this, and the through hole d is located in the recessed part, so that from the side of the free end of the forming shaft, the unevenness can be seen on the wall surface as shown in Fig. 4. Underdrain drain pipes g having holes e and f formed therein and a large number of through holes d formed within the recesses e will be continuously manufactured.

Incidentally, when supplying the strip b onto the forming roller 10 and forming it into an uneven shape, the uneven portion 1 of the forming roller 10
If 0a, 10b are relatively shallow, there is no problem because molding can be done easily, but on the other hand, if the uneven portions 10a, 10b are deep and difficult to mold, an auxiliary roller that meshes with the molding roller 10 may be used. It is preferable to use a plurality of auxiliary rollers or strings to circulate around the concave portions 10a of each forming roller 10, and to form the strip into an uneven shape along the forming roller 10 using this auxiliary roller or string.

Incidentally, the present invention is not limited to the above-mentioned apparatus. For example, a plurality of rod-shaped bodies having the same shape as the forming roller 10 are rotatably supported in an inclined position, and while each of the rod-shaped bodies is rotated, the rod-shaped bodies are It is also possible to manufacture an underdrain drain pipe similar to that described above by supplying a strip on the body in the same manner as described above.

According to the present invention as described above, it is possible to efficiently and continuously manufacture an underdrain drain pipe in which an uneven portion is formed on the peripheral wall and a large number of through holes are formed in the concave portion. Since the through-hole is cut and formed at a certain time, stress cracks do not occur in the through-hole part as in the conventional method.
Therefore, it is possible to prevent the production of defective products or to prevent the drainage action from being obstructed when buried.

Further, in the present invention, unlike conventional means, any resin can be used, such as polyethylene resin, etc.
When used as an underdrain drainage pipe, its cold resistance can be improved and cracks can be prevented.

Furthermore, since the underdrain drain pipe obtained by the present invention has uneven parts formed on the peripheral wall, it has excellent flexibility, and when transporting the underdrain drain pipe, it can be rolled and stored on a drum, etc., making it extremely convenient. In addition, since it is highly flexible, it is possible to bury the pipe along the uneven ground when burying it, and since the culvert drain pipe has a through hole in the recessed part, there is no need to remove mud during burying. This allows for good drainage without clogging.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of a manufacturing device used in the present invention, FIG. 2 is a front view showing an extrusion port portion of the extrusion molding machine, and FIG. 3 is a simplified view of the manufacturing process using the device. diagram showing,
FIG. 4 is a front view of an underdrain drain pipe manufactured by the present invention. 10... Forming roller, 10a, 10b...
... Uneven part, 11... Extrusion molding machine, 13...
... cutter, b ... band-shaped body, d ...
...Through hole, e, f...Irregular wall part, g...
...Drainage pipe.

Claims (1)

[Claims] 1. A belt-shaped body continuously extruded from an extrusion molding machine is fed to a forming shaft consisting of a plurality of forming rollers with a plurality of irregularities on the circumferential surface, and as the forming rollers rotate, the forming shaft is This is a manufacturing method for obtaining an underdrain drainage pipe with an uneven wall surface from the side, in which a large number of through holes are formed at equal intervals in the belt-shaped body extruded from an extrusion molding machine while the belt-shaped body is in an uncured state. By supplying the formed strip onto the forming shaft so that the through holes of the strip are located in the recesses of each roller in the forming shaft, an underdrain drain pipe having a large number of through holes formed in the wall recesses is obtained. A method for manufacturing a highly flexible underdrain drainage pipe characterized by: