JPS6227684B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a synthetic resin spacer for optical fiber cables, and more particularly to a method and apparatus for manufacturing a spacer that allows a tension member to be inserted accurately into the center of the spacer.

In order to simplify the production of conventional multilayer structures, optical fiber cables are manufactured by forming multiple concave grooves 12 on the outer surface of a synthetic resin wire 10 and attaching a tension member at the center of the wire 10, as shown in FIG. A member 14 is inserted to serve as a spacer, and an optical fiber core 16 is arranged within the groove 12.

However, it is difficult to insert the tension member 14 accurately on the axis of the wire 10, and the tension member 14 may be offset from the axis of the wire 10, resulting in a decrease in strength as a spacer, or even worse.
There are disadvantages in that the cable is exposed in the groove 12 and has a negative effect on the optical transmission performance of the cable.

The present invention has been made in order to solve the above-mentioned difficulties, and its purpose is to provide an extruder for extruding synthetic resin by heating and melting it, in which the tension member can be inserted accurately on the axis of the wire, and the purpose is to provide an extruder that heats and melts synthetic resin and extrudes it by forming pleats on the inner peripheral surface. A nozzle having an extrusion hole in which a shaped protrusion is formed is provided rotatably in a horizontal plane, and a guide tube provided in the vicinity of the nozzle is inserted into the resin flow path of the extruder and passed through to the center of the extrusion hole. The tension member is guided vertically downward so as to pass through the nozzle, and while the nozzle is rotated in a horizontal plane, the heated and melted resin is extruded vertically downward onto the tension member while rotating around the vertical line, and the resin is The tension member is fed out vertically downward in synchronization with the extrusion speed, and the resin is cooled and solidified onto the tension member by passing through a cooling water tank installed below the nozzle, and then taken out, and is turned into resin between the nozzle and the cooling water surface. A method for manufacturing a synthetic resin spacer for an optical fiber cable, which is characterized by adding a spiral twist to form a spiral groove in which an optical fiber core can be arranged and housed on the resin surface, and an extrusion device thereof. Attach the die head to the tip of the machine,
A head shaft is fit and supported in the die head so as to be rotatable about its axis in the vertical direction, and a circumferential groove communicating with the resin inflow path from the extruder is provided approximately in the center of the head shaft, and the head shaft is inserted radially into the circumferential groove. A through hole is provided that penetrates in the radial direction, a resin passage is provided below the through hole on the axis of the headshaft and communicates with the through hole, and a through hole for inserting the tension member is provided above the through hole on the axis of the headshaft. An optical fiber characterized in that a hole is provided, a tension member guide cylinder is provided in the resin passage, and a nozzle having an extrusion hole in which a pleated protrusion is formed on the inner circumferential wall is attached to the lower end of the head shaft. The present invention provides an apparatus for manufacturing synthetic resin spacers for cables.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings.

First, the apparatus according to the present invention will be explained. Second
In the figure, 20 is a die head, and an extruder 22
fixed at the tip.

A shaft fitting hole 24 is formed in the center of the die head 20 and penetrates in the vertical direction, and a resin inflow path 26 from the extruder 22 communicates with the substantially central portion of the fitting hole 24 from the perpendicular direction.

Reference numeral 28 denotes a head shaft, which is fitted and held in the shaft fitting hole 24 so as to be rotatable about its axis, and has a circumference wider than the opening of the resin inflow path 26 at a portion thereof corresponding to the resin inflow path 26. A groove 30 is carved.

A through hole 32 is bored in the circumferential groove 30 and extends radially through the headshaft 28, and the through hole 32 communicates downward from this position with a resin passage 34 provided on the axis of the headshaft 28. The lower part of this resin passage 34 is formed into a large diameter part 36, and the head shaft 28 is opened at the lower end.

The resin inflow path 26, the circumferential groove 30, the through hole 32, and the resin passage 34 form a resin flow path.

Reference numeral 38 designates a tension member 40 guide hole, which passes through the head shaft 28 from its upper end on the axis line and communicates with the through hole 32, and is formed to have a small diameter slightly larger than that of the tension member.

42 is a nozzle nut, and the head shaft 2
8 is screwed onto a male threaded portion 44 carved at the lower end of the headshaft 28, and protrudes downward from the head shaft 28, and its axis has the same diameter as the large diameter portion 36 of the resin passage 34, extending slightly downward and expanding in diameter, toward the lower end. A nozzle holding hole 46 is formed through the nozzle holding hole 46 whose diameter gradually decreases.

A pulley 47 is fitted to the lower end of the headshaft 28, and is connected to a drive source (not shown) via a V-belt (not shown) so that the headshaft 28 can be rotated about its axis. .

Reference numeral 48 shown in FIGS. 3a and 3b is a nozzle, which has the same outer shape as the inner shape of the nozzle holding hole 46, is fitted into the nozzle holding hole 46, and is tightened and fixed with the nozzle nut 42, and is attached to the head shaft. It is designed to rotate together with 28.

The nozzle 48 has a large-diameter hole 50 that continues to the resin passage 34, a small-diameter hole 52 that continues to the large-diameter hole 50, and an inner circumferential surface that opens at the nozzle end after the small-diameter hole 52. An extruded hole 56 having a circular protrusion 54 is formed.

Reference numeral 58 shown in FIGS. 4a and 4b is a tension member guide cylinder, which is fitted into the large diameter hole 50 of the nozzle 48.

The guide tube 58 has both tapered ends and a semicircular recess 60 formed on the outer periphery of the center portion to guide the resin to the extrusion hole 56 of the nozzle 48 .

In addition, the extrusion hole 5 of the nozzle 48 is provided at the tip of the guide tube 58.
A small cylindrical portion 62 that slightly protrudes from the center of the guide tube 58 is provided, and a tension member insertion hole 64 that extends along the axis of the guide tube 58 passes through the small cylindrical portion 62 and faces the center of the extrusion hole 56. .

In FIG. 5, 22 is the extruder described above, and 20 is its die head.

Reference numeral 70 indicates a reel for feeding out a tension member, which is located above the die head 20 and supported by an appropriate member; 72 is a first cooling water tank, which is arranged below the lower end of the nozzle 48 of the die head 20, and which is supported by an appropriate member. The nozzle 48 is supported by the nozzle 48 and is configured to be movable up and down, so that the distance between the water surface position and the lower end position of the nozzle 48 can be adjusted as appropriate.

74 is a second cooling water tank, which is the first cooling water tank 7
2, and is provided with a reversing roller 76 and a reversing roller 78 at predetermined positions inside.

At a predetermined position on the bottom of the first cooling water tank 72, there is a linear passage hole (not shown) for extruded resin.
A circulation pump (not shown) is provided to send slightly more water than the amount of water flowing down this passage hole from the second cooling water tank 74 to the first cooling water tank 72. A small amount of water is always overflowing from the water tank 72 to keep the water surface in a fixed position.

Note that 80 is a known take-up machine, and 82 is a take-up reel.

The device of the present invention is configured as described above. Next, its effects will be explained together with the method of the present invention.

First, as a preparation step, the tension member 40 wound around the tension member feeding reel 70 is inserted into the tension member guide hole 38 of the head shaft 28 and guided into the resin passage 34. The member is passed through the member insertion hole 64 and pulled out below the extrusion hole 56 of the nozzle 48 .

This operation can be easily accomplished by removing the nozzle nut 42 from the headshaft 28.

Next, a driving source (not shown) is activated to rotate the nozzle 48 together with the head shaft 28 (the tension member 40 does not rotate), and pour the heated and melted resin into the resin inflow path 26, the circumferential groove 30, the through hole 32, and the resin. It passes through the passage 34, the tapered portion of the guide tube 58, and the recessed portion 60 of the guide tube 58, and is extruded vertically downward from the extrusion hole 56 onto the tension member 40. The tension member 40 is let out downward in synchronization with the extrusion speed of the resin, enters the first cooling water tank 72 together with the resin, and is further inserted into a passage hole (not shown) provided at the bottom of the first cooling water tank 72. It penetrates and leads out into the second cooling water tank 74.

Next, it is brought into contact with the lower surface of the reversing roller 76, reversed and guided upward, and is brought into contact with the upper surface of the reversing roller 76 and pulled out horizontally, and is held by the take-up roller 80 and taken up and wound up in synchronization with the resin extrusion speed. It is wound on a reel 82 and taken up.

After the resin cools and solidifies, the reversing roller 7
However, since the resin immediately after being extruded from the nozzle 48 is in a softened and molten state, the rotation of the nozzle 48 causes it to move around the tension member 40 around its axis. The resin slides and rotates, and at the position where it enters the water surface of the first cooling water tank 72, it solidifies on the tension member 40 and becomes non-rotating, so the resin is twisted in a spiral between the nozzle 48 and the water surface. Extrusion hole 5 of nozzle 48
By the protrusions 54 provided on the inner circumferential surface of the resin 6, a spiral groove is formed on the resin surface, and the resin is solidified and taken off to obtain a desired spacer. The pitch of the spiral of this groove is determined by the extrusion speed of the resin, the rotational speed of the nozzle 48, the relative relationship between the nozzle 48 and the water surface, etc., and can be arbitrarily adjusted by changing any of these factors.

In this case, the tension member 40 is
When the resin flows into the resin passage 34 in the head shaft 28 from the resin inlet passage 26 of No. 2, the resin goes around the circumferential groove 30 and flows through the through hole 32 that opens into the resin passage 34 from opposite sides. The tension member 40 is connected to the head shaft 2.
8, and is guided accurately to the center of the extrusion hole 56 by the guide tube 58,
Position exactly on the axis of the extruded resin.

Furthermore, by setting the distance between the end of the nozzle 48 and the water surface to about 3 to 5 mm, the tension member 40 does not bend during this time, and the resin is cooled and solidified while the tension member 40 remains in the center. .

Furthermore, since the resin is extruded vertically downward, unlike when extruded horizontally, the resin does not sag in the radial direction.

In addition to metal wire, heat-resistant resin, glass fiber, etc. can be used for the tension member.

As described above, according to the method and apparatus of the present invention, the tension member can be accurately positioned on the axis of the extruded resin that is the wire material, and the tension member can be used for optical fiber cables that have excellent strength and do not impair optical communication performance. This has the remarkable effect of providing a spacer of

Although the present invention has been variously explained above with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It is.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the optical fiber cable, Fig. 2 is a sectional view showing the die head of the extruder, Fig. 3a is a sectional view of the nozzle, Fig. 4b is a side view thereof, and Fig. 4a is the guide tube. 5 is a side view of the front view, and FIG. 5 is an explanatory diagram showing the entire manufacturing apparatus. 10...Wire rod, 12...Concave groove, 14...Tension member, 16...Optical fiber core wire, 20...
Die head, 22...extruder, 24...fitting hole,
26... Resin inflow path, 28... Head shaft,
30... Peripheral groove, 32... Through hole, 34... Resin passage, 36... Large diameter part, 38... Guide hole, 40...
Tension member, 42... Nozzle nut, 44
... Male thread part, 46 ... Nozzle holding hole, 47 ...
Pulley, 48... Nozzle, 50... Large diameter hole, 5
2...Small diameter hole portion, 54...Protrusion, 56...Extrusion hole, 58...Tension member guide tube, 60...
Recessed part, 62... Small cylindrical part, 64... Tension member insertion hole, 70... Tension member feeding reel, 72... First cooling water tank, 74... Second cooling water tank, 76, 78 ...Reversing roller, 80
...Take-up machine, 82... Take-up reel.

Claims (1)

[Scope of Claims] 1. An extruder for heating and melting and extruding synthetic resin is provided with a nozzle having an extrusion hole in which pleated protrusions are formed on the inner circumferential surface so as to be rotatable in a horizontal plane. guiding a tension member vertically downward so as to pass through a guide tube provided in the resin flow path close to the nozzle and through the center of the extrusion hole;
While rotating the nozzle in a horizontal plane, the heated and melted resin is extruded vertically downward onto a tension member while rotating around a vertical line, and the tension member is fed out vertically downward in synchronization with the extrusion speed of the resin; The resin is passed through a cooling water tank installed below the nozzle, cooled and solidified on a tension member, and then taken out, a spiral twist is added to the resin between the nozzle and the cooling water surface, and an optical fiber core is applied to the resin surface. 1. A method for manufacturing a synthetic resin spacer for optical fiber cables, the method comprising forming a spiral concave groove in which spacers can be placed and housed. 2. A die head is attached to the tip of the extruder, a head shaft is fit and supported vertically inside the die head so as to be freely rotatable about its axis, and a circumferential groove is provided approximately in the center of the head shaft to communicate with the resin inflow path from the extruder. A through hole is provided in the circumferential groove that penetrates the headshaft in a radial direction, and a resin passage is provided on the axis of the headshaft below from the through hole to communicate with the through hole, and from the through hole to the upper headshaft. A through hole for insertion of the tension member is provided on the axis, a tension member guide cylinder is provided in the resin passage, and a nozzle having an extrusion hole in which a pleated protrusion is formed on the inner peripheral wall is provided at the lower end of the head shaft. A manufacturing device for a synthetic resin spacer for optical fiber cable, characterized in that a spacer made of synthetic resin is attached to the fiber optic cable.