JPH0726342Y2 - Resin coating device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin coating device for coating a resin on the outer surface of a twisted wire formed by twisting wire rods such as optical fibers, and in particular, such as an optical fiber strand. While twisting the wires, apply a thermosetting resin such as silicone resin to the outer surface,
When coating the outer surface of the stranded wire, it may be applied to the outer surface of the stranded wire, and the thermosetting resin that falls from this outer surface may be circulated and used again to coat the outer surface of the stranded wire. The present invention relates to a resin coating device.

Conventional technology and problems Conventionally, an optical cable formed for use in an optical composite overhead ground wire is formed by twisting optical fiber strands together and applying heat such as silicone resin, epoxy resin or polyimide resin to the outer surface of the formed twisted wire. Apply a curable resin to finish to a specified outer diameter, then heat cure in a heating furnace such as an electric furnace, and then form a PFA resin layer as the outermost layer on the outer surface of the thermosetting resin that has been heat cured. Alternatively, a polyimide tape or the like is wound around to form an optical cable. As described above, the silicone resin used to form the optical cable has a cushioning effect on the optical fiber to protect the optical fiber housed in the optical cable, and the optical resin inside the optical cable for connection work. This is used to prevent the optical fiber from being damaged when the outermost PFA resin layer or the like is peeled off with a sharp blade or the like when separating the fiber strands.

When a resin such as a silicone resin is interposed in the optical cable when the optical cable is manufactured in this way, that is, when the resin is filled, for example, as shown in FIG. 5, three optical fiber strands are twisted together. Taking the core stranding as an example, first, the optical fiber strands B are twisted together to form a strand, and then the silicone resin C is applied to the outer surface of the strand to form an optical cable. An air portion A is formed at the center of the optical cable by the optical fiber of the book. The air in the air portion A may expand due to heating during the subsequent heat curing treatment and may foam through the silicone resin layer, so that the outer surface of the silicone resin layer is smoothed to a prescribed outer diameter dimension. There is a problem that it may not be possible to finish or the outer surface of the silicone resin layer may be damaged in extreme cases.

In order to prevent the formation of an air portion in the center of such an optical cable, a step drawing die is used to squeeze the air in the air section at the center of the three-fiber twisting of the optical fiber, and a silicon resin is applied to the optical fiber using the step drawing die. Attempts have been made to take out the air in the central part while applying it, but the air in the central part is squeezed out, but when this air is not completely squeezed out and many remain in the silicon resin coating layer from the central part. In the same manner as described above, during the heat curing treatment, this air expands due to heating and foams through the silicone resin layer to smooth the outer surface of the silicone resin layer to a specified outer diameter dimension. It may not be able to be finished or, in extreme cases, the outer surface may be damaged. Further, even if the air does not foam, if the air is contained in the silicon resin layer, the stress applied to the optical fiber element wire in the optical cable becomes non-uniform, which is not preferable.

Then, at that time, excess silicon resin of the silicon resin applied to the optical fiber while squeezing air is squeezed out into the silicon resin receiving tank arranged below the step drawing die part. Although it falls, the silicone resin that has fallen into this receiving tank contains a considerable amount of air. To circulate this silicone resin and reuse it again for coating the outer surface of the stranded wire, use it after venting air. There is a need to. However, it is not easy to remove the air contained in the silicone resin, and in order to remove this air, it is usually stored in a low temperature room such as a refrigerator for several tens of minutes,
Since it is necessary to leave it alone, it is impossible to circulate the silicon resin immediately and apply it to the optical fiber at the stage drawing die to reuse it. Until now, it is reused for this air release. The silicon resin to be stored is stored in a low temperature room such as a refrigerator for several tens of minutes as described above, left for air removal, and then manually circulated in a resin supply tank for supplying the stair drawing die part. It was Therefore,
The work efficiency when applying silicone resin to the outer surface of the stranded wire was poor.

Also, when applying silicone resin or the like to the outer surface of the stranded wire,
When foreign matter is mixed in, problems occur in the outer diameter dimension of the silicon resin layer and the like, as described above.

Further, in the case of the silicone resin as described above, as can be understood from the viewpoint of the characteristics of the silicone resin, the silicone resin gradually hardens with the passage of time even at room temperature. The silicon resin supply passage for supplying the silicon resin gradually becomes a closed state and becomes narrower. As a result, the supply of the silicon resin to the step drawing die part deteriorates, causing a problem in the outer diameter dimension of the silicon resin layer. This causes a problem that the work of coating the optical fiber with the silicone resin must be performed in a short time, and the time of the work of coating the silicon resin cannot be extended.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Therefore, an object of the present invention is to allow air bubbles or the like to be mixed into a resin layer when a resin such as a silicone resin is coated on a stranded wire formed by twisting wires such as optical fibers. It is an object of the present invention to provide a resin coating device capable of coating a resin without using the resin coating device.

Another object of the present invention is to coat a resin such as a silicone resin on a stranded wire formed by twisting wire rods such as optical fibers without introducing foreign matter and to reduce the time for coating the silicone resin. It is an object of the present invention to provide a resin coating device that can take a sufficient curing time of silicon.

Means for Solving the Problems The above objects are achieved by the resin coating apparatus according to the present invention. In summary, the present invention applies a thermosetting resin supplied through a step drawing die to a twisted wire formed by twisting a plurality of supplied wire rods, and applies the thermosetting resin to the outer surface of the twisted wire. In a resin coating device for coating a stranded wire by applying a thermosetting resin while squeezing, a resin supply tank for supplying the resin to the step drawing die and the resin supplied for application to the step drawing die. A resin receiving tank for receiving excess resin, a pump for sucking the resin in the resin receiving tank, a resin in the resin receiving tank sucked up by the pump is stored and held, and bubbles in the resin are removed. At the same time, the resin coating device is provided with a bubble removing tank for supplying the resin for removing air bubbles to the resin supply tank through a foreign matter mixing prevention filter for eliminating foreign matter mixing.

Embodiment Hereinafter, the present invention will be described based on an embodiment with reference to the accompanying drawings.

1 and 1a, there is shown a resin coating apparatus 10 according to the present invention. This resin coating device 10 is entirely covered by a low temperature chamber 11 such as a refrigerator which is maintained in a temperature atmosphere of about 15 ° C. In other words, the resin coating device 10 is housed in the low temperature chamber 11. . A wire rod take-up reel 12 in which a wire rod such as an optical fiber is wound upstream of a low temperature chamber 11 accommodating the resin coating device 10.
A stand 13 that holds and houses the wire rod is provided between the stand 13 and the low temperature chamber 11.
A twisting machine 14 is provided which twists the wire materials supplied from 12 to form a twisted wire S.

A stranded wire insertion port 15 is provided in a portion of the low temperature chamber 11 facing the stranded wire machine 14, and the stranded wire S formed by the stranded wire machine 14 can be inserted into the low temperature chamber 11. .

The resin coating device 10 has a support frame 16 and a stage drawing die 17 arranged at a predetermined position inside the support frame 16 for gradually reducing the stranded wire S supplied thereto.
Placed on 16 and fixed to the staged drawing die 17, for example, a thermosetting silicone resin, an epoxy resin, a resin such as a polyimide resin (in this embodiment, as the resin, CY52-130 manufactured by Toray Silicone Co., Ltd. is used. The first tank for supplying the resin, that is, the resin supply tank 18 is provided. In this embodiment, the stage drawing die 17 includes a first stage drawing die 17a, a second stage drawing die 17b, and a third stage drawing die 17c, each of which has a diameter of, for example,
It is 5.0 mm, 2.0 mm and 0.9 mm.

Further, the resin coating device 10 is a second tank disposed below the step drawing die 17, that is, a resin receiving tank for receiving the excess resin applied to the stranded wire by the step drawing die 17 and falling. It also has a circulation pump 20 fixed to the upper wall of the low temperature chamber 11, for example. Then, the resin coating device 10 drops the resin containing the air bubbles contained in the resin receiving tank 19 into the resin receiving tank 19, that is, the resin to be circulated by being used for application by the circulation pump 20 via the pipe 21. The suctioned resin is supplied by the circulation pump 20 through the pipe 22 and stored therein, and also has a third tank for removing bubbles mixed in the resin, that is, a bubble removing tank 23. .

The resin supply tank 18 and the bubble removing tank 23 are connected by a pipe 24 through a hole provided at the bottom of the side wall of each tank, that is, a resin flow port, and a pipe.
A foreign matter mixture prevention filter 25 for preventing foreign matter from mixing into the resin supply tank 18 from the bubble elimination tank 23 is disposed inside the pipe on the side of the bubble elimination tank 23 which is one end side of 24.

Further, in order to supply the resin from the resin supply tank 18 to the step drawing die 17, the resin supply passage 26 provided in the first drawing die 17a through the hole provided at the bottom of the resin supply tank 18 is provided.
A communication pipe 27 that communicates with is provided.

At the position of the support frame 16 facing the twisted wire insertion port 15 of the low temperature chamber 11, there is provided a twisted wire supply port 28 for supplying a twisted wire into the resin coating device 10, and this twisted wire is supplied. The line S is further supplied to the step drawing die 17 and passes therethrough, but each step drawing die 17a, 1a of the step drawing die 17
The supply passage lines of the stranded wire S in 7b and 17c are made to coincide with each other. The twisted wire S that has passed through the exit of the step drawing die 17c of the step drawing die 17 provided on the twisted wire exit side of the support frame 16 is made to pass through the twisted wire exit 29 provided on the twisted wire exit side of the low temperature chamber 11. ing.

Therefore, the twisted wire insertion port 15, the twisted wire supply port 28, the twisted wire passage line and the twisted wire outlet 29 of each stage drawing die 17a, 17b, 17c are matched so that the twisted wire can pass without any trouble. Will be there.

Resin is applied to the outer surface of the stranded wire S by the resin coating device 10 downstream of the stranded wire outlet 29 of the low greenhouse 11 to heat and cure the stranded wire S that has passed through the stranded wire outlet 29 of the low temperature chamber 11. The electric furnace 30 is disposed, and downstream of the electric furnace 30, an extruder for forming a PFA resin layer as the outermost layer on the outer surface of the cured stranded wire, or for winding a polyimide tape or the like. A coating means 31 is provided to allow the final optical cable to be made.

A take-up machine 32 for taking up the optical cable conveyed from the covering means 31 is disposed downstream of the covering means 31, and a take-up machine 34 for taking up the optical cable by controlling the tension to a suitable state by a dancer 33 is provided. It is arranged.

The operation of the resin coating apparatus of the above embodiment of the present invention as described above will be described below.

Now, when the resin coating device 10 is in the operating state, the resin coating device 10 is operated in the low temperature chamber 11 kept at a temperature of 15 ° C.
Being housed within, the resin, such as silicone resin, in the resin coating apparatus 10 is viewed by comparing Figures 2a and 2b, whose characteristics are shown with respect to temperature, time and viscosity. As can be clearly understood, it is set in a state of preventing curing at room temperature for a considerable time, and therefore, sufficient working time is required to apply and coat the resin on the outer surface of the stranded wire. In this state, from the take-up reel 12 of the stand 13, for example, a diameter of 0.4 m.
An optical fiber (three in the present embodiment) as a strand of m is supplied to a twisting machine 14 to form a twisted wire S. The twisted wire S is a twisted wire insertion port 15 and a support frame of the low temperature chamber 11. Step drawing die 17 in the resin coating device 10 through the 16 twisted wire supply ports 28
Is supplied to.

The outer surface of the stranded wire S supplied to the first-stage drawing die 17a of the stage-drawing die 17 is predetermined from the resin supply tank 18 via the communication pipe 27 and the resin supply passage 26 of the first-stage drawing die 17a. Supplied a fixed amount of resin such as silicone resin,
As it is applied and squeezed by a predetermined amount, this stranded wire S is
Furthermore, the amount of resin applied to the outer surface of the twisted wire is reduced by a predetermined amount by the second-stage drawing die 17b, and further reduced by a predetermined amount by the third-stage drawing die 17c. Air bubbles at the center of the twisted core are removed and removed, and a resin-coated stranded wire having a predetermined outer diameter of, for example, 0.9 mm is formed. Bubbles in the stranded wire S can be removed by drawing in this stage drawing die 17. At this time, the stranded wire S is supplied to the drawing die 17a of the first stage.
The excess resin used for coating and coating the resin falls into the resin receiving tank 19 arranged below the step drawing die 17, and the resin in this resin receiving tank 19 is pumped. At 20 it is sucked up into the bubble removal tank 23.

The resin sucked up in the bubble removal tank 23 is stored here, and the bubbles in the resin float up on the upper surface of the bubble removal tank 23 while being held, so that the bubbles in the resin in the bubble removal tank 23 are removed. , The resin from which the air bubbles in this bubble removal tank 23 have been removed are
It is supplied to the resin supply tank 18 through the pipe 24, and is stored and held in the resin supply tank 18 for coating and coating on the outer surface of the stranded wire S which is supplied later. Such a cycle is repeated, so that the resin is circulated through the resin supply tank 18, the resin receiving tank 19, and the bubble removing tank 23.

The formed resin-coated stranded wire passes through the stranded wire outlet 29 of the low temperature chamber 11 and is conveyed to the electric furnace 30, where it is heated and the resin-coated portion of the stranded wire is cured.

The cured resin-coated stranded wire is then wrapped by the coating means 31 with an outermost layer of a PFA resin layer or a polyimide tape as an outermost layer to produce a final optical cable having an outer diameter of 1.1 mm, for example. To be done. Therefore, this optical cable is manufactured. Therefore, in this optical cable, as shown in FIG. 3, the outer surface of the stranded wire S formed by twisting the optical fibers B as wire rods is coated with the silicone resin C, and the outer surface thereof is further covered with the PFA resin layer. Alternatively, the outermost layer D such as a polyimide tape is coated.

This optical cable is then taken up by the take-up machine 32 and taken up by the take-up machine 34 while the tension is controlled to a suitable state by the dancer 33.

In the above embodiment, the number of optical fibers supplied is three.
Although the present invention has been described as a book, the present invention is not limited to the number of the embodiments described above, and this number can be set to any number, and the form of the optical cable can be selected as desired. it can. For example, as shown in Fig. 4, FRP as a reinforcing material is provided at the center of the finally formed optical cable.
Alternatively, the steel wire E is interposed and the surrounding area is used as a wire rod.
The optical fiber B of the book is twisted together to form a twisted wire S, and thereafter, the outer surface thereof is covered with a silicone resin C, and the outer surface thereof is covered with a PFA resin layer or a polyimide tape. The outermost layer D is covered.

Effects of the Invention As described above, according to the resin coating device of the present invention, a thermosetting resin such as a silicone resin is provided on the outer surface of a stranded wire formed by twisting wires such as optical fibers from a resin supply tank. When the silicone resin layer is formed by supplying, coating and coating, the resin can be uniformly coated on the stranded wire without mixing air bubbles such as air into the silicon resin layer. When applying and coating a resin on the surface, it is possible to circulate and use an extra resin that has not been used for coating and coating, and to use again for coating and coating the stranded wire. Further, it also has an effect of preventing foreign matter from being mixed into the silicone resin layer.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional explanatory view of an embodiment of a manufacturing apparatus for manufacturing an optical cable using the resin coating apparatus according to the present invention. FIG. 1a is a schematic perspective view of the resin coating device portion shown in FIG. 2A and 2B are graphs showing the relationship between the temperature, time and viscosity of the resin used in the resin coating apparatus shown in FIG. 1, respectively. FIG. 3 is a schematic cross-sectional explanatory view of the final optical cable manufactured by the manufacturing apparatus shown in FIG. FIG. 4 is a schematic cross-sectional explanatory view of another final optical cable manufactured by another manufacturing apparatus similar to the manufacturing apparatus shown in FIG. FIG. 5 is a schematic cross-sectional explanatory view for explaining an air portion generated when a final optical cable is manufactured by a conventional method. 10: Resin coating device 11: Low temperature chamber 17: Step drawing die 18: Resin supply tank 19: Resin receiving tank 20: Pump 23: Bubble removal tank 25: Foreign matter mixing filter S: Stranded wire

Claims (2)

[Scope of utility model registration request] 1. A thermosetting resin supplied through a step drawing die is applied to a twisted wire formed by twisting a plurality of supplied wire rods, and the resin is applied to the outer surface of the twisted wire. In a resin coating device that coats a stranded wire by applying while drawing, a resin supply tank that supplies the thermosetting resin to the step drawing die and an excess of the resin supplied to the step drawing die for application. A resin receiving tank that receives a resin, a pump that sucks up the resin in the resin receiving tank, and stores and holds the resin in the resin receiving tank that has been sucked up by the pump, and removes air bubbles in the resin,
A resin coating device, comprising: a bubble removing tank for supplying resin for removing bubbles to the resin supply tank through a foreign matter mixing prevention filter for eliminating foreign matter mixing. 2. The resin coating device is housed in a low temperature chamber.