JPH0132485B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Background and Objects of the Invention] The present invention particularly relates to a spacer type optical fiber cable manufacturing apparatus.

FIG. 1A is a cross-sectional view of a conventional optical fiber cable, B is a cross-sectional view of the spacer of A, and C is a front view of the spacer of B. In FIG. 1, numeral 7 denotes a spacer, which is extruded from a resin having a spiral groove 4 on the outer periphery of the tension member 1 at the center. The optical fiber 2 is inserted into the groove 4 of the spacer 7, and the presser tape 5 is wound around the outer periphery of the rib 3 and the opening surface of the groove 4 into which the optical fiber 2 is inserted. The outside is further covered with a sheath 6. Note that A is the groove pitch.

In this conventional spacer-type optical fiber cable manufacturing device, the groove 4 of the spacer 7 is formed by a rotating die of an extruder, so if the cross-sectional dimensions of the groove 4 exceed 3 mm in width x 3 mm in depth, the cross-section of the spacer 7 Even if it is extruded into a predetermined shape, during the cooling process, due to the difference in the weight of the rib 3 and the cooling rate of the material near the rib 3 and tension member 1, the rib 3 will collapse and the groove 4 will collapse, causing the groove to collapse. This will result in a mismatch between pitch A and the twisting pitch. Therefore, in order to ensure the cross-sectional shape of the groove 4, it is necessary to increase the outer diameter of the spacer 7, but this is undesirable as it increases the cost. Furthermore, if the groove pitch A is less than 300 mm, the ribs will collapse and the width of the groove 4 will become narrower, so when the cable is bent, the transmission characteristics will deteriorate due to the influence of lateral pressure and the allowable bending radius will become larger. Furthermore, when forming spacer grooves using an extruder, uneven rotation of the rotating die of the extruder causes irregularities in the pitch of the spacer grooves, resulting in problems such as overlapping of the grooves when the fiber 2 is inserted.

As described above, the problem when trying to form a spacer having the ribs 3 and grooves 4 on the outer periphery of the tension member 1 by one extrusion is that the ribs 3 fall down. In an attempt to resolve the
(Japanese Patent Application No. 1983-126505), Japanese Patent Application No. 1986-8644
Publication No.) etc. have been proposed.

The former invention, disclosed in Japanese Patent Application No. 57-8643, involves extruding a spacer having a spiral groove, and then rotating the spacer to follow the rotation of the groove while keeping the spacer fed out from an extruder warm in a heat insulating tank. A pressure die is used to adjust the external shape of the spacer, and a cutting die that rotates independently of the rotation of the pressure die and follows the rotation of the groove is used to adjust the cross-sectional shape of the groove formed by the pressure die to a predetermined shape. This invention relates to an apparatus for cutting into shapes. but,
In this device, the resin of the spacer is made soft enough to be deformed under pressure by the pressure die, and the cutting die rotates independently of the pressure die to cut the groove. There is a high risk that the cutting die will cut away from the groove formed by the pressure die. In addition, since the resin in the spacer is kept warm so that it becomes soft, when the spacer comes out of the heat insulating tank and cools down, the carefully molded grooves become deformed, resulting in a loss of precision in the cross-sectional shape of the grooves. There was a problem.

In the latter invention of Japanese Patent Application No. 57-8644, after a spacer having a spiral groove is once extruded, the spacer is fed out from an extruder and kept warm in a heat-retaining tank, while a rotatable roller is placed in a circle. This device relates to a device that adjusts the outer appearance of the spacer by fitting the peripheral stepped portion into the groove, and further pressure-forms the cross-sectional shape of the groove formed by the roller into a predetermined shape using a drawing die. It is. However, in this device, as in the invention of Japanese Patent Application No. 57-8644 mentioned above, the resin of the spacer is kept warm so that it becomes soft enough to be easily deformed under pressure, so the spacer that comes out of the heat insulating tank is cooled. This resulted in the problem that the carefully molded grooves were deformed, resulting in poor accuracy in the cross-sectional shape of the grooves.

The present invention has been developed in view of the above circumstances, and it is possible to freely select the cross-sectional shape and groove pitch of the groove on the outer periphery of the spacer, and also to eliminate the problem of rib collapse and narrowing of the groove. An object of the present invention is to provide an optical fiber cable manufacturing apparatus that can improve the accuracy of the cross-sectional shape of the optical fiber cable.

[Summary of the Invention] The optical fiber cable manufacturing apparatus of the present invention is configured to cool and harden a spacer extruded from an extruder and having a spiral groove having a cross-sectional shape smaller than the cross-sectional shape of a predetermined groove on the outer peripheral surface. After the provided water tank, there is provided a groove cutting device provided with a cutter for cutting a groove having a cross-sectional shape smaller than that of the predetermined cross-sectional shape of the predetermined groove of the spacer into a predetermined cross-sectional shape; A guide that rotates and is integrally connected to the cutter so as to rotate independently of the cutter and synchronously rotate in the same direction without rotating around the advancing direction of the spacer as a rotation axis. In this way, the above-mentioned purpose is achieved.

[Embodiment] An embodiment of the optical fiber cable manufacturing apparatus of the present invention will be described below with reference to FIGS. 2 and 4.

Figure 2 is a schematic plan view of the spacer manufacturing device;
The figure is a schematic diagram of a manufacturing device that inserts an optical fiber into a groove of a spacer to form a cable.

In Fig. 2, 8 is an extruder, 9 is a crosshead, 10 is an extrusion die, 11 is a motor, 12, 1
3 is a sprocket foil, 14 is a water tank, 15 is a groove cutting device, and 16 is a take-up caterpillar.

First, the extruder 8 is placed around the outer periphery of the tension member 1.
The spacer 7 is formed by extruding the resin provided with the spiral groove 4 having a cross-sectional shape smaller than the predetermined cross-sectional shape of the groove from an extrusion die 10 . The extrusion die 10 is driven by a motor 11 with sprocket wheels 12 and 13 interposed therebetween. Subsequently, the spacer 7 is cooled by passing through a water tank 14,
The resin of the spacer 7 is cooled and hardened. In this state, since the cross-sectional shape of the groove 4 is smaller than the predetermined shape, deformation due to cooling is small and there is almost no rib collapse.

Thereafter, the groove 4 having a cross-sectional shape smaller than the predetermined cross-sectional shape of the groove is cut deeper by a groove cutting device 15, which will be described in detail later, into a predetermined shape, and then the spacer 7 is taken out by a take-up caterpillar 16. .

In addition, in FIG. 4, 17 is a winding machine, 18 is a take-up capstan, 19 is a taping head, 2
0 is a gathering die, 21 is a gathering board, 22 is a cage,
23 is a bobbin, and 24 is a feeder. In FIG. 2, the spacer 7 in which the groove 4 has been cut by the groove cutting device 15 is sent out directly from the take-up caterpillar 16 in FIG. Enter 20.
On the other hand, the optical fiber 2 enters the collecting die 11 from the bobbin 23 attached to the cage 22 via the collecting plate 21. Here, after the optical fiber 2 is inserted into the groove 4 of the spacer 7 and the tape 5 is wrapped by the taping head 19,
It is attracted by a take-up capstan 18 and wound around a winder 17. Thereafter, a sheath 6 is coated in a sheath extruder (not shown) to complete the optical fiber cable.

FIG. 5 is a sectional view showing the structure of one embodiment of the groove cutting device 15. In the figure, a holder 31 is rotatably supported by a case 38 via a ball bearing 33 and a slide bearing 34.
A cutter 25 for cutting the cross-sectional shape of the groove 4 of the spacer 7 into a predetermined shape is fixed to a cutter holder 28 by a bolt 26, and this cutter holder 28 is fixed to a holder 31 by a bolt 39.
Further, 35 is a guide fitted into a groove having a cross-sectional shape smaller than that of a predetermined groove of the spacer 7, and is fixed to the extruder 8 side of the holder 31 with a bolt 36. That is, the guide 35 and the cutter 25 are integrally connected to the holder 31, and do not rotate independently, but always rotate in synchronization in the same direction. Therefore, when the guide 35 rotates following the rotation of the spiral groove, the cutter 25 can cut the cross-sectional shape of the groove into a predetermined shape while rotating in the same direction in synchronization with the rotation of the guide 35. At the same time, since the guide 35 is fitted into the groove, the portion where the cutter 25 deviates from the groove is not cut away, and it is possible to stably obtain the helical groove 4 with a highly accurate cross-sectional shape.

In addition, when extrusion molding a guide groove having a cross-sectional shape smaller than the cross-sectional shape of the predetermined groove of the spacer 7, the cross-sectional shape of the groove is set to have a depth of Hmm and a width of Wmm.
When, the value of H x W is 1.5 ~ 3.0 x H x 1.5 ~
It is desirable that the size be in the range of 3.0×W, and if the dimensions are within this range, the guide 35 will not come out of the groove.

Further, the cutter 25 and the guide 35 are attached with bolts 26 and 36 so that their positions can be adjusted in the circumferential direction, and the holes for attaching the bolts 26 and 36 of the cutter 25 and the guide 35 are elongated holes, and the spacer The outer diameter of the groove 7 and the depth of the groove 4 can be adjusted. The cutter holder 28 is fixed with a bolt 39 so that the cutter holder 28 can be adjusted in the circumferential direction so that the cutter 25 is positioned in the same groove as the guide 35.

It is preferable that the rotary cutter 25 gradually cuts deeper into the groove 4 in stages 1 to 5, thereby preventing the tension from becoming extremely strong. In addition, one cutter holder 28 has 4 to 6
Make sure that the book cutter 25 can be attached. Furthermore, the die 30 through which the spacer 7 passes has an inner diameter that is 0.5 to 1.5 mm larger than the outer diameter of the spacer. It is desirable that the chips 27 are discharged through the loop hole 37.

As described above, the optical fiber cable manufacturing apparatus of this embodiment uses a groove having a cross-sectional shape smaller than the predetermined cross-sectional shape of a predetermined groove of a spacer that has been extruded and then cooled and hardened as a guide that is fitted into the groove and rotates. Since the cross-sectional shape of the groove is cut into a predetermined shape using cutters that always rotate in synchronization in the same direction, the cross-sectional shape of the groove and groove pitch dimensions can be freely selected, eliminating the problem of conventional rib collapse and narrow grooves. This can be reliably prevented, and the cross-sectional shape of the groove can be processed with high precision. Furthermore, since the outer diameter can be made small, the cable itself can be made inexpensive, and since the groove pitch can be made small, the bending characteristics are good and the allowable bending radius can be made small. Furthermore, optical fibers are not compressed by narrow grooves or overlapping due to groove pitch mismatches are eliminated, reducing transmission loss and reducing work man-hours.

In the above embodiment, the guide 35 is attached directly to the groove cutting device 15, and the groove cutting device 15 is attached to the front part of the take-up caterpillar 16, but as shown in FIG. cage 2
It may be configured such that it is fixed to the cage 22 and rotates integrally with the cage 22. In this way, the cage 22, which rotates following the rotation of the groove, plays the same role as the guide 35, making it possible to process a spacer having a groove with a highly accurate cross-sectional shape, and also to adjust the optical fiber insertion pitch and groove. You can match the pitch. In this case, case 38 is fixed to cage 22.

Further, the adjustment between the guide and the cutter may be structured like a chuck on a lathe, and instead of the cutter, a rotary blade may be attached for scraping.

[Effects of the Invention] As described above, the optical fiber cable manufacturing apparatus of the present invention is extrusion-molded by a guide that rotates following the rotation of the spacer groove and a cutter that always rotates in synchronization with the same direction, and then cooled and hardened. Since the groove is cut into a predetermined cross-sectional shape, the cross-sectional shape of the groove is smaller than that of the predetermined groove of the spacer. Since narrowing can be avoided, and the cutter does not cut away from the predetermined position, it is possible to obtain a spiral groove with a highly accurate cross-sectional shape, which is a remarkable effect.

[Brief explanation of drawings]

Fig. 1A is a sectional view of a conventional optical fiber cable, B is a sectional view of the spacer in A, C is a front view of B, and Fig. 2 is a schematic plan view of a spacer manufacturing apparatus according to an embodiment of the present invention. 3 is a schematic diagram showing another embodiment of the present invention, FIG. 4 is a schematic diagram of an apparatus for inserting an optical fiber into a groove of a spacer to form a cable according to an embodiment of the present invention, and FIG. 5 is a diagram showing a groove cutting device. FIG. 2 is a partially cross-sectional side view of one embodiment of the device. 1: Tension member, 2: Optical fiber, 4:
groove, 5: pressure tape, 7: spacer, 8: extruder, 14: water tank, 15: groove cutting device, 19: taping head, 20: collecting die, 21: collecting plate,
22: Cage, 23: Bobbin.

Claims (1)

[Claims] 1. An extruder that molds a spacer by extruding a resin that has a spiral groove on its outer peripheral surface with a cross-sectional shape smaller than a predetermined cross-sectional shape of a predetermined groove around a tension member that is driven to travel, and extrusion molding from the extruder. a water tank for cooling and hardening the spacer, a groove cutting device equipped with a cutter for cutting a groove having a cross-sectional shape smaller than the cross-sectional shape of the predetermined groove of the spacer into a predetermined cross-sectional shape; a cage that repeats optical fibers inserted into grooves having a cross-sectional shape; and a gathering die that collects the optical fibers fed out from the cage via a gathering plate and then stores them in the grooves of a predetermined cross-sectional shape of the spacer. and a taping head that wraps a pressure tape around the outer periphery of the spacer fed out from the collecting die and housing the optical fiber, the groove cutting device is configured to follow the grooves of the spacer. A rotating guide is provided so as to be integrally connected with the cutter so as to rotate synchronously in the same direction without rotating with the advancing direction of the spacer as an axis of rotation independently of the cutter. Optical fiber cable manufacturing equipment.