JPS58162322A - Method and apparatus for manufacturing corrugated pipe - Google Patents

Abstract

PURPOSE:To manufacture efficiently corrugated pipe by a method wherein a cooled resin string body is wound along the trough of a group of forming rolls that are located in a circular form and have crests and trough in the axial direction on a peripheral surface and a fused resin tape is wound along the crests to weld neighboring side edges into each other. CONSTITUTION:A cooled thermoplastic resin string body W is wound along the trough 5 of a group of forming rolls 3 that is located in a circular form so that they are collected and form a cylindrical surface on the outside and has crests 4 and trough 5 in the axial direction on the peripheral surface. Therefore, if a thermoplastic resin tape T extruded from a die 7 of an extruder 6 is stuck on the spiral string body W along the crests 4, the tape T is mounted on the spiral string body W, introduced spirally to form a corrugated section by the crest 4 of the forming roll 3 and weld neighboring side edges into each other. In this manner, a synthetic resin corrugated pipe can be manufactured efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a corrugated tube made of thermoplastic resin, and more particularly, to a method and apparatus for extremely efficiently manufacturing an i-corrugated tube with flexibility and sufficient flattened strength. It is something.

Conventionally, as a method for manufacturing a synthetic resin corrugated pipe whose pipe wall surface is corrugated in cross section, for example, Japanese Patent Application Laid-Open No. 54-120685
In the publication, it is proposed to form a corrugated pipe by winding a molten synthetic resin tape in a complete spiral around the curved surface of a rotating shaft body having a spiral protrusion on the circumferential surface.

However, the above method is manufactured by supplying a molten synthetic resin tape freshly extruded from an extruder to the surface of a rotating shaft and fusing the side edges of the tape to the side edges of the preceding tape. Since the tube body is not cooled sufficiently on a short rotating shaft body, and when the molding speed is increased, the tube body sent out from the free end of the rotating shaft body is likely to be crushed or deformed, and the wavy shape The drawback was that the manufacturing efficiency of the tubes was extremely low.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, the present invention aims to provide a method for manufacturing corrugated synthetic resin pipes with high efficiency, and a manufacturing apparatus suitable for carrying out the method.

That is, the present invention is arranged on a strip made of a cooled thermoplastic resin in a circular manner so that the outer surfaces thereof form a cylindrical surface. After the forming roll group having troughs is rotated and advanced in a spiral manner along the troughs, a tape made of a molten thermoplastic resin is wound onto this spiraling strip along the crests of the forming roll group. The tape is guided by the strip in a spiral manner, joining the adjacent side edges and fusing with the strip to form the entire pipe wall. A method for manufacturing a tube, and a number of rolls of equal diameter arranged in a circle at equal intervals so as to come together to form a cylindrical surface on the outer surface, and having peaks and valleys formed in the axial direction on the surface. The troughs of each roll are rotated in the same direction at the same speed by a drive device, and the forming rolls are formed separately from the troughs so that the crests of each roll rotate freely. The gist of the present invention is a corrugated tube manufacturing apparatus characterized in that the corrugated tube is installed horizontally in a cantilevered manner on the front surface.

The method of the present invention will be explained below using examples shown in the drawings.

Figures 1 and 2 show an example of an apparatus for carrying out the method t of the present invention, (1) is a machine cabinet, (8H31... is a machine cabinet (11)
A group of forming rolls protruding from the front surface of the machine casing (1 ) The main shaft is connected to a gear mechanism inside the main shaft and rotated by a drive source (not shown), and the circumferential surface of each forming roll (3) has ring-shaped peaks (4) and valleys spaced equally apart in the axial direction. A portion (5) is formed.

In this device, a strip CwI made of a thermoplastic resin such as polyethylene, which has been extruded and then cooled, is transferred to a forming roll (
When it is rolled over the crotch part (5), the strip (Wl) rotates forward in a spiral manner above the trough part (5) of the forming roll.

Next, when the strip (3) begins to rotate forward on the trough (5) of the forming roll (8), the die (7) of the extruder (6)
) is extruded from a tape made of thermoplastic resin such as polyethylene (' 3) and is guided in a spiral shape to form the crest (4) of the forming roll (8).
), and the adjacent side edges are fused together to form a corrugated tube (Hl).

At this time, the strip M that conveys the tape (T) is
It is fused and integrated with T) and attached to the inner surface between the troughs of the corrugated tube (H) to form a part of the tube wall.

Thereafter, the corrugated tube (H) is continued to rotate forward on the forming roll (3), and is eventually fed out from the free end of the forming roll ((), cooled, and then cut to a desired length, completing the forming of the corrugated tube.

According to the method of the present invention, a strip of cooled plastic is wound around the troughs of a forming roll, and even when the forming roll is rotated at high speed, the strip continues to spiral on the troughs in a stable state. The newly extruded molten tape is placed on this strip and guided in a spiral shape at a high speed, so that the corrugated tube can be formed at a significantly increased forming speed without any problems in forming the corrugated tube. can be manufactured.

Further, according to the method of the present invention, it is also possible to easily manufacture a corrugated pipe in which the inner surface of the trough of the pipe wall is reinforced with strips.

FIG. 8 relates to an improvement of the forming roll (3) in FIG.
) is integrally formed and rotates with differential drive on both sides, so the valley part (
The strip (4) wound around the groove (5) comes off from the valley (5) and ends up at the peak (
(8) is a forming roll that protrudes from the front of the machine casing, and its base end is connected to the gear mechanism inside the machine casing. A drive shaft (91) that rotates in the same direction at a constant speed due to the rotation of the main shaft that is rotated by a drive source, a plurality of valley forming rings 0 that are fitted and fixed on the outside of this drive shaft (9), and this valley. A bearing made of self-lubricating metal (1
1) It is composed of a plurality of peak-forming rings (12) that are fitted at intervals through.

(18) connects the valley forming ring (lO) to the drive shaft (9)
(14) is a retaining plate.

In this device, valley forming phosphorus, ri° (10) I/
i It rotates together with the drive shaft (9), but the peak forming ring (
1g) F! Since it is designed to rotate freely, the strip wound around the troughs of the forming roll does not move to the crests, but rotates forward on the troughs in a more stable state, making the corrugated tube smoother. has the advantage of high-speed molding.

[Brief explanation of the drawing]

The drawings fully show an embodiment of the invention, FIG. 1 is a side view of one apparatus showing the implementation of the uninvented method, FIG. 2 is an enlarged view of the forming roll of FIG. 1, and FIG. It is a partially broken side view of the forming roll in an example of an apparatus.

Claims (1)

[Claims] (11. Strips made of cooled thermoplastic resin are arranged in a circle so that the outer surfaces thereof form a complete cylindrical surface, rotate in the same direction at a constant speed, and have peaks in the circumferential axial direction. After nine months, the forming roll group having a part and a trough is rotated and advanced in a spiral manner while staying in the trough part.
A tape made of a molten thermoplastic resin is wound onto the advancing strip, overflowing to the ridges of the forming roll group, and the tape is guided by the strip and guided in a spiral shape while adjoining the tape. A method for manufacturing a corrugated tube, characterized in that the side edges are joined together and fused to the strip to form a tube wall. (2) Consisting of several rolls of equal diameter arranged in a circle at equal intervals so that they come together to form a cylindrical surface on the outer surface, and have peaks and valleys formed in the axial direction on the circumferential surface. ,
The troughs of each roll are rotated by a drive device in the same direction at the same speed, and the crests of each roll are formed separately from the troughs so that they can all rotate freely. A manufacturing device for corrugated tubes, which is characterized by being installed horizontally in a cantilevered manner.