JPS5926456B2 - A method for producing a resin pipe in which holes are arranged in parallel in the tube wall in the tube axis direction, and the holes are closed at appropriate locations. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a resin tube in which holes are arranged in the tube wall in parallel in the tube axis direction and the holes are closed at appropriate locations.

By making the walls of resin pipes such as hard vinyl chloride resin pipes relatively thick and arranging many holes in parallel in the pipe axis direction, we aim to reduce the weight of the pipes and improve their strength against flat loads. Attempts have been made to reduce deformation due to stress such as earth pressure.

A method and apparatus for manufacturing such resin pipes were disclosed in Japanese Patent Application Laid-Open No. 52
This is proposed in the publication No.-89170. The resin pipe manufactured by this method and apparatus has holes in the pipe axis direction arranged in parallel on the pipe wall that continuously communicate with both end walls of the pipe. In the method of enlarging the diameter of a tube to use it as a tube socket, inserting the unexpanded end of another tube into this, and connecting it with adhesive, a seal ring, etc., the hole in the tube wall communicates with the inside and outside of the tube. There is a drawback that fluid leaks and cannot be used as is. Therefore, for example,
No. 2-52222 proposes closing the hole in the tube wall using a separate closing member, or crushing the hole by heating the tube end and pressing it against a mold.

However, if a closing member is used, the sealing of the hole 5 may not be complete, or the closing member may come off, and the end of the pipe may be crushed, and this work cannot be done on site. When the pipes are cut for reasons of the connection process, one of the pipes has a through hole communicating with it and cannot be used as is for connection. In view of the above points, this invention was made by attempting to close the holes in the tube wall at appropriate intervals during extrusion molding of such a resin tube. A resin pipe in which holes in the pipe axis direction are formed in parallel on the pipe wall using a mold having a passageway and pins arranged concentrically at appropriate intervals on the open end side of the resin passageway. is continuously extruded, the resin pipe is introduced into an annular space between an inner diameter regulating mold and an outer diameter regulating mold, and the taking speed of the resin pipe is intermittently reduced or stopped in the annular space. The resin is characterized in that the inner and outer walls of the hole portion of the tube wall are fused and closed at appropriate intervals by causing the tube wall to have holes arranged in parallel in the tube axis direction, and the holes are closed at appropriate locations. It depends on the method of manufacturing the pipe. Next, the present invention will be explained with reference to embodiments shown in the drawings.

1 is an extruder, a mold 2 is attached to the tip of the extruder 1, and a diameter regulating mold 3 is provided at the open end of the mold 2.

Reference numeral 6 denotes a take-off device for taking off the resin pipe 5 extruded from the mold 2.

4 is a cooling tank, and 7 is a cutting device. The mold 2 will be explained.

The core mold 21 and the outer mold 22 are supported by a spider 23 to form an annular resin passage 24.
A pin support 25 is disposed at 4 by a pin spider 26. A plurality of pins 27 are supported by the pin support 25, so that the pins 27 are arranged concentrically at equal intervals at the open end of the annular resin passage 24. each pin 2
A through hole 271 is bored in 7, and the pin support 25, pin spider 26 and outer mold 2 communicate with this through hole 271.
A passage 28 is formed through 2. The diameter regulation type 3 consists of an outer diameter regulation type 31 and an inner diameter regulation type 32, each of which is a cylindrical body with a predetermined inner diameter or outer diameter and a jacket cooling tank. A pressure reducing pipe from a pressure reducing device is provided that opens on the outer circumferential surface, and the inner and outer walls of the resin pipe 5 extruded from the mold 2 slide closely against the inner and outer circumferential surfaces of both the regulating molds 31 and 32. is being used.

The molten resin continuously extruded from the extruder 1 passes through the annular resin passage 24 of the mold 2 and is discharged into a tubular shape.

At this time, due to the presence of the pin 27, a hole 5 in the tube axis direction is formed in the tube wall.
1 is formed, and this resin tube 5 is guided between an outer diameter regulating mold 31 and an inner diameter regulating mold 32. When the speed at which the resin pipe 5 is picked up by the pulling device 6 is intermittently reduced or stopped, the annular passage 33 between the outer diameter regulating mold 31 and the inner diameter regulating mold 32
, the resin pipes 5 are relatively stagnant, and the peripheral wall of the hole 51 becomes thicker, approaches each other, and fuses together, resulting in the closed portion 51 of the hole 51.
1 is formed. As mentioned above, by intermittently slowing down or stopping the withdrawal speed of the resin pipe 5, the pin 27
The holes 51 in the tube wall formed by the holes 51 are closed at intervals.
1 resin tube 5 is continuously manufactured.

When opening the passage 28 and forming the hole 51 in the tube wall with the pin 27, pressurized fluid is sent into the hole 51 through the passage 28 to bring the inner and outer walls of the hole 51 into close contact with the regulating molds 31 and 32 to prevent their deformation. You can do it like this. Of course, the pressure of the pressurized fluid at this time needs to be adjusted according to the molding situation. Based on the above, since the method of the present invention temporarily slows down or stops the take-up speed of the resin tube formed by the pin during extrusion molding, the holes in the tube wall can be easily spaced at appropriate intervals. It is possible to provide a pipe suitable for piping construction, which eliminates the trouble of separately blocking the pipe.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the main part of FIG. 1. 1... Extruder, 2... Mold, 21... Core mold, 22
...Outer mold, 24...Annular resin passage, 27...Pin, 5...Resin pipe, 6...Take-off device.

Claims (1)

[Claims] 1. Holes in the tube axis direction were formed in parallel on the tube wall using a mold that had an annular resin passage and pins were arranged concentrically at appropriate intervals on the open end side of the resin passage. Continuously extrude the resin pipe, guide the resin pipe into an annular space between the inner diameter regulating type and the outer diameter regulating type, and intermittently reduce the take-up speed of the resin pipe in the annular space. Alternatively, the inner and outer walls of the hole portion of the tube wall are fused and closed at appropriate intervals by stopping the tube. A method for manufacturing resin pipes.