JPS63128928A - Method and apparatus for forming synthetic resin tube with spiral filament on inner surface - Google Patents

Abstract

PURPOSE:To integrally form hard resin filaments in spiral shape onto the inner surface of a tube at the stage that the tube is extruded from an extrusion machine by a method wherein hard synthetic resin is discharged in the form of filaments from a die, on the outer peripheral surface of which discharge ports are open and which is rotated in the tube, and at the same time the tube is axially run by means of a take-off. CONSTITUTION:Molten soft resin is fed to a melt feed opening 8 and extruded through a nozzle 7 in order to form a tube (a) constituting a tube main body. At the same time, warps (b) are supplied through warp guide holes 10, which are bored through a fixed die 5 from outside to inside, into the nozzle 7 and at the same time pulled ahead an extruder by getting over a projection 9, which is protrusively provided on the inner surface of the fixed die 5. At the position that a warpcontaining tube leaves the nozzle 7, which is formed between the fixed die 5 and a nipple 6, hard resin melt is discharged from discharge ports 14, which are open on the outer peripheral surface at the tip of a rotary die 12, during the rotation of the rotary die 12, in the form of filaments (c). The filaments c are integrally pasted onto the inner peripheral surface of the tube (a) by being formed in a spiral shape due to the rotation of the filaments (c) and the axial movement of the tube (a).

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for molding a synthetic resin tube with spirally warped filaments on its inner surface, which is used to protect cables such as electric wires and optical fibers. Regarding the molding device 9.

(Prior Art) Corrugated pipes are commonly known as synthetic pipes that are considered to have circular or polygonal stripes arranged in a spiral pattern on the inner surface.

This corrugate vibe is a mold in which a cylindrical melt extruded from a double pipe land is expanded by compressed air jetted from an air hole, and is delayed by a caterpillar that circulates in front of the outside of the double pipe land. By crimping the corrugated portion of the pipe, a Korgu 1-pipe (fluted pipe) is continuously formed.

By the way,] Lugate Vibe is made of synthetic resin such as polyethylene or vinyl chloride resin, and not only the inner surface but also the outer surface is uneven, so the vibrator itself lacks pressure resistance.
It has the disadvantage that it is easily broken by external pressure.

Therefore, in order to obtain a synthetic resin pipe with excellent pressure resistance and flexibility, it has been considered to attach a reinforcing body made of hard synthetic resin to the inner circumferential surface of the pipe in a spiral shape. The method involves integrally fixing a reinforcing wire made of hard synthetic resin to one side of a flexible seven-bar shaped soft resin strip along its longitudinal direction.
Such a soft resin band is wound spirally with a part of it A-bar wrapped so that the reinforcing wire piece is placed on the inside, and the overlapped part is welded and integrated to form a pipe shape.

Therefore, in this method, the band is first formed and then transferred to the next winding process and welded, which requires time and effort for forming.
There is a problem in that it is difficult to control the dimensions of the completed tube.

(Problems to be Solved by the Invention) In view of the above-mentioned conventional problems, the present invention has been developed in such a way that the filaments are already integrally formed in a spiral shape on the inner surface in the extruded state from the extrusion molding machine. The purpose is to make sure that

(Means for solving the problem □) The technical means taken by the present invention to solve the above problem is that the inner surface of the molten tube extruded from between the nipple and die of the extrusion While avoiding adhesion of the filaments discharged from the discharge port opened on the outer peripheral surface of the rotary die, the tube is run in the axial direction by a take-up device, thereby pasting the filaments in a spiral shape on the inner surface of the die. This is a method of molding.

In addition, the device used to implement the molding method rotatably supports a rotary die with an extruder connected to the rear part in the nipple of the extrusion molding machine, and an Iil at the axis of the rotary die.
The discharge port communicating with the provided passage opens on the outer peripheral surface of the tip 11ri, and the discharge port portion is disposed in a fixed die in front of the nipple.

The extrusion molding machine for molding the tube body may be one that extrudes a single tube, a composite laminated tube, or a tube with warp threads. In addition, the discharge I of the rotary die that spirally adheres hard filaments (aggregate) to the inner surface of the tube is one or more on the outer circumferential surface, and if there are multiple on the rear right, the filaments are It can be arranged in multiple threads in a spiral shape.

(Function) According to the above means, the tube extruded from the extrusion molding machine is pulled in the axial direction by the take-off device, and inside the tube moving in the axial direction, a rotary die having a discharge port opened on the outer circumferential surface is placed. By rotating in position, the molten filaments discharged from the discharge port of the rotary die are stuck together in a spiral shape. Since the discharge port of the rotary die is located inside the fixed die of the extrusion molding machine, the filament is discharged and pasted from inside the tube by the rotation of the rotary die, and the outer diameter of the tube is regulated by the fixed die. It is held in place, and the filaments are adhered to the inner surface in a spiral pattern to form a continuous mold.

(Example) Embodiments of the present invention will be described below based on the drawings.

The drawing shows an extrusion molding machine for tubes with warp threads, which is equipped with a rotating die for discharging and spirally pasting hard reinforcing □ strong wire, and rectifying it inside the cylindrical main body 1! 12
A cylindrical nipple holder 3 is fitted and fixed through the cylindrical nipple holder 3, and a passage 4 through which a tube-forming melt flows is defined between the two. Nipple 6 connected to nipple holder 3
A melt supply port 8 communicating with the passage 4 is formed on the circumferential surface of the main body 1 .

On the inner circumferential surface of the fixed die 5 that defines the tapered nozzle 7, an annular protrusion 9 with a protrusion amount approximately half the gap between the nozzles 7 is formed, and at the inner base of the protrusion 9. , Warp thread guide holes 10 are bored at equal intervals in the circumferential direction toward the outer surface of the fixed die 5, and reinforcing warp threads are inserted through the warp thread guide holes 10 and run over the protrusions 9. Fixed die 5
He was being dragged forward.

Inside the nipple holder 3 and the nipple 6, a rotary die 12 having a discharge port 13 on the outer peripheral surface of its tip is rotatably supported.

In the rotary die 12, a passage 13 is opened along the axis from the rear end to the tip by a rod, and the tip of the passage 13 is perpendicular to the axis at a position in front of the tip and on a diametric line. It communicates with the opened discharge port 14, and the discharge port 14 portion is positioned in the fixed die 5 in front of the nipple 6.

In addition, the outer shape of the rotary die 12 is a step A-1 shape that gradually becomes smaller in diameter toward the tip, and the two steps A-1 after IYI are rotatably supported by bearings 15 and 15'. At the same time, the outer shape of the space between the front and rear bearings 15 and 15' supported by the bearings 15 and 15' is smaller in diameter than the inner diameter of the nipple holder 3, and the air passage 1G is formed. An air supply port 17 is opened in the main body 1.

Further, a portion of the rotary die 12 that protrudes rearward from the main body 1 is an extruder 18 that extrudes and supplies a molten body of hard 71 resin.
The sprocket 21 is integrally fixed to the outside of the rotary die 12 between the main body 1 and the extruder 18, - The rotation of the printer 22 is caused by the chain 23
The rotary die 12 is driven to rotate. In the figure, 24 is a heater, 25 is a cold 1J1 water tank,
26 is a take-up machine, and 27 is a winding machine.

Next, I will explain the operation of the above device.
Molten soft resin is fed into the melt supply port 8 for molding the tube a constituting the tube body and extruded from the nozzle 7, and at the same time, it is extruded from the air supply port 17 into the air passage 16.
The tube a is shaped into a cylindrical shape by the compressed air sent into the tube. Incidentally, the warp yarns are supplied into the nozzle 7 through the warp guide holes 10 bored from the outside to the inside of the fixed die 5, and pass over the n protrusions 9 protruding from the inner surface of the fixed die 5. As the molten resin is drawn out to the front of the extruder, the molten resin fed into the nozzle 7 crosses the protrusion 9 and fills the gap with the same width as the original gap. The tube a is integrally embedded within the wall thickness of the tube a, contributing to reinforcement and stable molding of the tube a. The process before the extrusion molding machine for the tube a is as is well known today: it is passed through a cooling water tank 25 to be cooled and hardened, and then sequentially pulled by a pulling machine 26.
It is wound up by a winding machine 27.

At the point where the warp-filled tube formed as described above comes out from the nozzle 7 between the fixed die 5 and the nipple 6, the rotary die 12 rotates to melt the hard resin from the discharge port 14 on the outer peripheral surface of the tip. The body is discharged onto the filament C, and as the filament C rotates and the tube a moves in the axial direction, the filament C is integrally attached to the inner peripheral surface of the tube a in a spiral shape. Ru.

Note that the bits of the filament C that are helically attached and integrated on the inner surface of the tube a can be adjusted as appropriate by the moving speed of the tube a and the rotational speed of the rotary die 12 that discharges the filament C. be. Furthermore, when the number of discharge ports in the rotary die 12 is two opposite to each other on the diameter line, the discharged filaments C are formed into a multi-filament coil shape, and the manufacturing efficiency is doubled. Furthermore, the cross-sectional shape of the filament C discharged from the discharge port 14 of the rotary die 12 is not limited to a circular shape;
It can be formed into a triangular cross-section, a quadrilateral cross-section, a pentagonal cross-section, etc. Further, the tube a is not limited to the single tube with warp threads shown in the figure, but may of course be a laminated tube with multiple layers.

(Effects of the Invention) As detailed above, the method of molding a synthetic resin tube having spiral filaments on the inner surface of the present invention is a single tube or a laminated tube of soft synthetic resin extruded by an extrusion molding machine. Before the resin hardens, a die with a discharge opening on the outer circumferential surface is rotated within the tube to discharge the hard synthetic resin in a linear manner. Therefore, at the stage of extruding the tube from an extrusion molding machine, it is possible to mold the tube by integrally pasting a spiral strip of hard resin on the inner surface.

Therefore, compared to the conventional method of forming a hose by spirally winding a tape-like material, since the hose is formed in a due-I shape from the beginning, there are no problems such as peeling, and stable products can be efficiently produced. This is a method that can be used. .

In addition, the molding Km is rotatably inserted and supported in the nipple of a tube extrusion molding machine with a rotary die having a passage in its axis, and an extruder is connected to the rear of the rotary die. The tip of the rotary die is located in the fixed die in front of the nipple, and the passage of the rotary die is bent in the radial direction at the tip plane and communicates with the discharge port opening on the outer circumferential surface. It can be easily manufactured by modifying the extrusion molding machine used for molding (hose). Moreover, the device that spirally attaches filaments to the inner surface of the tube utilizes the axial movement of the tube, and inside the tube,
Since it has a structure in which a die with a discharge port on the outer circumferential surface is rotated, it can be manufactured at a low cost in terms of structure. Moreover, since the filaments discharged from the rotating die are attached and integrated inside the fixed die, the dimensional viscosity is constant, and a stable tube body can be formed. Furthermore, by forming a plurality of discharge ports in the rotary die on the circumference, it is possible to
□The filaments formed into a multi-filament coil shape can improve manufacturing efficiency.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a pseudo-sectional side view, FIG. 2 is a sectional view taken along line (2) to (2) in FIG. 1, and FIG.
The figure is a schematic diagram of a tube manufacturing line. In the figure, 1: Main body 5: Fixed die 6: Nipple 12 Two-rotation die 14: Discharge port a: Tube C: Wire

Claims (4)

[Claims] (1) Before a single tube or laminated tube of soft synthetic resin extruded by an extrusion molding machine is cured, a die with a discharge opening on the outer circumferential surface is rotated within the tube to form a filament of hard synthetic resin. At the same time, the tube is run in the axial direction by a take-up machine, so that the filaments of the hard resin are helically attached to and integrated with the inner surface of the tube. A method for molding synthetic resin pipes. (2) A patent characterized in that the number of filaments discharged in one rotation of the rotary die is a plurality of filaments spaced apart in the circumferential direction, and the filaments of hard resin are attached and integrated in a multi-strand spiral shape. A method for molding a synthetic resin pipe having spiral filaments on its inner surface as set forth in claim 1. (3) A rotary die with a passage in the shaft center is rotatably inserted and supported in the nipple of the extrusion molding machine, and the extruder is connected to the rear of the rotary die, and the tip of the rotary die is inserted from the nipple. It is located in the fixed die at the front, and the passage of the rotating die is bent in the radial direction in front of the tip and communicates with the discharge port opened on the outer circumferential surface. Synthetic resin pipe molding equipment. (4) A synthetic resin pipe having spiral filaments on its inner surface as claimed in claim 3, wherein a plurality of discharge ports are provided at intervals in the circumferential direction, and the rotary die is provided with a plurality of discharge ports at intervals in the circumferential direction. Molding equipment.