JPS5926457B2 - 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 tube manufactured by this method and apparatus has holes in the tube axis arranged in parallel on the tube wall that continuously communicate with both end walls of the tube. In this method, the diameter of the pipe is enlarged to form a pipe socket, and the end of another pipe whose diameter is not enlarged is inserted into the socket and connected with adhesive, a seal ring, etc., whereby the hole in the pipe wall communicates with the inside and outside of the pipe, and the fluid It has the disadvantage that it cannot be adopted as is because it is leaked. Therefore, for example, JP-A-52-5
Publication No. 2222 proposes that after manufacturing the resin tube, the hole in the tube wall is closed using a separate closing member, or the hole is crushed by heating the tube end and pressing it into a mold. has been done.

However, when using a closing member, the sealing of the hole may not be complete, or the closing member may come off, resulting in insufficient sealing, and if the end of the pipe is crushed, this work cannot be done on site.
Furthermore, when the pipes are cut for reasons related to 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-mentioned 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 having holes arranged in parallel in the pipe axis direction on the pipe wall is extruded using a mold having pins arranged at appropriate intervals on the open end side of the resin passage. In this case, the pin is provided with a through hole, and the hole closing member is intermittently supplied from the through hole to the hole of the resin tube. The present invention relates to a method of manufacturing a resin pipe with closed portions.

Next, the present invention will be explained with reference to embodiments shown in the drawings.

A is an extruder, a mold B is attached to the tip of the extruder A, and a cooling device C is provided following the mold B.

D is a take-up device for taking off the resin pipe E extruded from the mold B, and F is a cutting device for the resin pipe E. Mold B will be explained.

A core mold 1 and an outer mold 2 are supported by a spider 3 to form an annular resin passage 4, and a plurality of pins 5 are concentrically arranged at equal intervals at the tip of this annular resin passage 4. . The pin 5 is made of a cylindrical body having a through hole 51, is inserted into the outer mold 2, and has a closing member supply cylinder 6 in a portion protruding from the outer mold 2.
are connected to each other, and the hole closing members 7 are pushed by a pressing spring 61 so that the closing members 7 are supplied to the through holes 51 one by one. The hole closing member 7 supplied to the through hole 51 of the pin 5 is a push rod 8
By sliding it forward through the through-hole 51, it is sent toward the tip of the pin 5, and is fed to the hole e portion of the resin pipe E through the outlet of the mold B. The other end of the push rod 8 is a disk 9
This disk 9 is attached to a rod 101 of a hydraulic cylinder 10, and the disk 9 reciprocates around the outer periphery of the outer mold 2 due to the intermittent operation of the hydraulic cylinder 10. The push rod 8 also intermittently moves back and forth through the through hole 51 of the pin 5 to intermittently close the hole closing member 7 through the resin pipe E.
It is supplied to the hole e. The hole closing member 7 is a spherical, solid rod body that is the same or different from the resin pipe E, and its outer diameter is approximately the same size as the inner diameter of the through hole 51 of the pin 5.
Although the outer diameter is smaller than the outer diameter of the pin 5, the hole e of the resin pipe E extruded from the resin passage 4 of the mold B becomes smaller than the outer diameter of the pin 5 because the resin expands due to the so-called balance effect. It comes into close contact with the tube wall and the hole e is closed.

Furthermore, in order to actively reduce the diameter of the hole e in the tube wall, the speed at which the resin tube E is taken up may be temporarily reduced or stopped when the hole closing member 7 is fed from the pin 5.

In the resin tube E extruded from the mold B, a hole e in the tube axis direction is formed in the tube wall by the pin 7, and this hole e is intermittently penetrated by the through hole 51 of the pin 5 by the intermittently operated push rod 8. The holes e are closed at appropriate intervals by the supplied hole closing member 7, guided to a cooling device C to be cooled and solidified, and then cut into a predetermined length by a cutting device F. The intervals at which the holes e of the resin pipe E are closed by the hole closing members 7 are determined by the supply intervals of the hole closing members 7, and the intervals are not particularly limited, but are equal to or shorter than the cut length of the resin pipe E. It is normal to do this.

For example, if a 4 m long resin pipe is sealed in about four places, most of the holes in each resin pipe will be blocked even if the resin pipe is cut at a later piping site, and each resin pipe can be used for piping, which is preferable. Further, if a metal material is used as the hole closing member 7, the metal material will be buried in the hole e of the resin pipe E, and when used buried, it is convenient to be able to detect the buried position.

As described above, in the method of the present invention, a hole closing member is intermittently supplied from the pin to the hole portions of the resin tube wall formed by the pin during extrusion molding, so that the holes are closed at appropriate locations and separately. The trouble of clogging can be saved, and a pipe suitable for plumbing can be provided.

[Brief explanation of drawings]

FIG. 1 is a front view schematically showing an embodiment of the present invention;
2 is a partially enlarged sectional view of the opening of the mold E shown in FIG. 1, and FIG. 3 is a partially cutaway perspective view of the mold E. A...Extruder, B...Mold, E...Resin pipe, 1.
... Core mold, 2 ... Outer mold, 4 ... Annular resin passage, 5.
... Pin, 51... Through hole, 7... Hole closing member.

Claims (1)

[Claims] 1. Using a mold having an annular resin passageway and pins arranged at appropriate intervals on the open end side of the resin passageway, a resin pipe with parallel holes in the pipe axis direction is made in the pipe wall. In extrusion molding, a through hole is provided in the pin, and a hole closing member is intermittently supplied to the hole of the resin tube from the through hole. A method for producing a resin pipe in which holes are closed at appropriate locations.