JP5402858B2 - Self-supporting optical cable covering molding apparatus and covering molding method - Google Patents

Description

The present invention relates to a coating molding apparatus and a coating molding method for molding a jacket of a self-supporting optical cable into two layers.

  With the spread of information communication such as the Internet, in addition to increasing the communication speed and the amount of information, construction of an optical network has recently been progressing to support bidirectional communication and large-capacity communication. In this optical network, a FTTH (Fiber To The Home) service for connecting a communication carrier and each home directly with an optical fiber and providing a high-speed communication service has been started. As a result, there is an increasing demand for drop optical cables used for drawing optical cables into the home. As shown in FIG. 3A, in the optical fiber cable 100, the tension member 102 and the support wire 103 are integrally embedded in the cable jacket 104 in parallel with the optical fiber core wire 101 to increase the tensile strength of the optical cable 100. In addition, a structure that can be suspended and supported is used. When the optical cable 100 is drawn into the house, the neck part 106 is torn, the main body part 108 is separated from the support line part 107, and the optical cable 100 is drawn into the house.

  The optical cable 100 having this structure is usually provided with a V-shaped notch 110 for easily tearing the cable jacket 104 by hand and taking out the optical fiber core wire 101 inside. However, a problem has arisen in which the notch portion 110 pierces the laying tube and damages the optical fiber core wire 101 inside. For this reason, the jacket 104 is required to have a hardness that can resist the piercing of the spawning tube of the spider. Further, the optical cable 100 is required to have non-halogen flame retardancy as the application environment of the optical fiber cable expands. Here, in order to use a hard resin material for the jacket 104, there is a problem that the addition of a flame retardant is suppressed and sufficient flame retardancy cannot be realized.

  In order to satisfy the above requirements, in Patent Document 1, as shown in FIG. 3B, an optical cable 100 includes a main body portion 108 in which an optical fiber core wire 101 and a tension member 102 are arranged in parallel with an inner layer resin. The outer layer resin is covered and molded into two layers, and the supporting line portion 107 for supporting the suspension is integrally molded with the main body portion 108 via the narrow neck portion 106 using the outer layer resin. Here, the inner layer 104a is made of a hard resin that protects against spider laying tubes, and the outer layer 104b is made of a flame-retardant resin.

  In order to cover such two resin layers, there is a method in which a molding apparatus for molding the inner layer 104a and a molding apparatus for molding the outer layer 104b are arranged in tandem. However, this method requires a large installation space for molding equipment, and requires two molding apparatuses, resulting in high costs.

On the other hand, there is also a method of coating using a two-layer extrusion head. For example, Patent Document 2 discloses a two-layer extrusion head. FIG. 4 is a diagram schematically showing an extrusion head according to Patent Document 2. As shown in FIG. As shown in FIG. 4 , the extrusion head 120 has a flow path 122 that guides the resin to the die hole 121. The flow path 122 is formed on the inner layer resin flowing from the upstream side in the traveling direction of the wire through the first introduction path 123 and flowing through the first flow path 123 through the second flow path 124 from the downstream side. The resin for the outer layer is poured into the resin, and the two-layered resin is covered with the wires arranged by the nipple 125.

JP 2009-265394 A JP 2006-175675 A

  However, it has been difficult to simultaneously mold the two layers of the optical cable 100 of FIG. 3B with the two-layer extrusion head 120 shown in FIG. This is because the two-layer extrusion head 120 shown in FIG. 4 is configured so that the two-layer resin is covered with the wire material, so that the inner layer 104a such as the outer cover of the optical cable 100 in FIG. This is because the outer layer 104b is not suitable for molding a jacket having a shape that is not similar. That is, when the two-layer outer cover of the optical cable of FIG. 3B is formed by the two-layer extrusion head 120 of FIG. 4, the inner layer 104a and the outer layer 104b as shown in FIG. Since the neck portion 106 is covered with the hard inner layer resin, there is a problem that the tearability between the main body portion 107 and the support wire portion 108 of the optical cable 100 is impaired.

Accordingly, the present invention has been made in view of the above-described circumstances, and provides a coating molding apparatus and coating molding method for a self-supporting optical cable capable of molding an inner layer and an outer layer of a jacket in an unsimilar shape. With the goal.

The optical fiber core wire and the tension member are arranged in parallel, and the main body part is coated and formed into two layers with the inner layer resin and the outer layer resin, and the suspension support line part is made of the outer layer resin with the narrow neck part. Through a device for forming a self-supporting optical cable that is integrally molded with the main body via a first resin reservoir composed of a nipple and a first die for supplying the resin for the inner layer, and a resin for the outer layer. Ru provided with O and sump second resin comprising a first die and a second die being. The first die has an inner layer die hole through which the optical fiber core wire and the tension member pass, and a support wire hole through which the support wire of the support wire portion passes, and the inner layer die hole is for the inner layer of the main body portion. The molded layer made of resin has a cylindrical guide portion extending on the second die side for guiding the outer layer resin in the second resin reservoir so as not to contact for a predetermined distance . The diameter is slightly larger than the outer diameter of the support wire enough to scrape off the resin for the inner layer coated on the support wire. In addition, it is preferable that at least the second die of the nipple and the second die is provided with a centering mechanism capable of aligning with the first die.

  The self-supporting optical cable coating molding method uses a self-supporting optical cable coating molding apparatus, using a hard resin for weathering as the resin for the inner layer, and using a flame-retardant resin for the resin for the outer layer. ing.

  According to the present invention, the resin for the outer layer is supplied from the second resin reservoir while the inner layer resin supplied from the first resin reservoir is maintained in its molded shape. As a result, the influence on the inner layer during molding of the outer layer is reduced, and even if the shapes of the inner layer and the outer layer are dissimilar, they can be molded simultaneously.

FIG. 1 is a cross-sectional view of the coating molding apparatus of the present invention. FIG. 2 is a partial arrow view for explaining the details of FIG. FIG. 3 is a diagram showing a cross section of the optical cable. FIG. 4 is a diagram showing a crosshead according to the prior art.

The coating molding apparatus 1 will be described with reference to FIGS. 1 and 2. FIG. 1A is a cross-sectional view of the coating molding apparatus 1 of the present invention. FIG. 1B is a partially enlarged view showing the AA cross section of FIG. 2 is a partial arrow view for explaining the details of FIG. 1, in which (A) shows a BB cross section of FIG. 1, (B) shows a CC cross section of FIG. 1, and (C) These are figures which show the DD cross section of FIG.
As shown in FIG. 1A, the coating molding apparatus 1 includes a coating molding apparatus main body 2, a base 3, a support member 4, a wire rod holder 5, a sleeve 6, a nipple 7, and an inner layer die ( A first die 8 and an outer layer die (second die) 10.

  The coating molding apparatus main body 2 has a cylindrical shape and has an internal space. The internal space includes a base holder 2a that holds the base 3, a sleeve holder 2b that holds the sleeve 6, a first resin flow path 2c that forms part of the first resin flow path, and an inner layer It has a die holding part 2d, a second resin flow path part 2e that forms part of the second resin flow path, and an outer layer die holding part 2f that holds the outer layer die 10. The first resin flow path portion 2c communicates with the first resin supply path 11 into which the resin for the inner layer is poured. The second resin flow path portion 2e communicates with the second resin supply path 12 into which the outer layer resin is poured.

  The base 3 has, for example, a cylindrical shape having a small diameter portion 3a and a large diameter portion 3b, and has a through hole 3c. The base 3 is fixed to the coating forming apparatus main body 2 by fixing the large diameter portion 3b to the base holding portion 2a.

  The support member 4 has a cylindrical outer shape, and a holding hole for holding the wire rod holder 5 is formed. The support member 4 is inserted into the through hole 3 c of the base 3 and is held by the push bolt 13. The support member 4 can be adjusted in position in a direction orthogonal to the traveling direction of the wire by adjusting the push bolt 13.

  The wire rod holder 5 is for guiding the wire rod to the nipple 7 and has a pipe shape. The wire rod holder 5 has a nipple attached to one side (downstream in the direction of travel of the wire rod). The other side (the upstream side in the traveling direction of the wire) is fitted and held in a holding hole formed in the support member 4. In the present embodiment, one optical fiber core, two tension members, and one support wire are inserted into the wire holder 5.

  The outer shape of the sleeve 6 has a truncated cone shape, and the large diameter side is held and fixed by the sleeve holding portion 2 b of the coating forming apparatus main body 2. When the sleeve 6 is held by the sleeve holding part 2b of the coating molding apparatus main body 2, a part of the first resin flow path 14 is formed by the outer peripheral surface 6a of the sleeve 6 and the first resin flow path part 2c. A wire rod holder 5 for guiding the wire rod is passed through the sleeve 6.

  The nipple 7 has a truncated cone shape, and has a plurality of nipple holes for positioning the wire at a predetermined position (see FIG. 2A). The nipple hole is formed with an optical fiber core hole 7a for positioning the optical fiber core wire, a tension member hole 7b for positioning the tension member, and a support wire hole 7c for positioning the support line. The nipple 7 is supported on the one end side (downstream side in the traveling direction of the wire) of the sleeve 6 by being supported by the wire holder 5. The outer peripheral surface 7 a of the nipple 7 constitutes a part of the first resin flow path 14 when the nipple 7 is supported on one end side of the sleeve 6.

  The nipple 7 is supported by a wire rod holder 5 supported by the support member 4. As described above, the support member 4 can be adjusted in position in the direction orthogonal to the traveling direction of the wire by the push bolt 13. Thereby, the position of the nipple 7 can be adjusted by adjusting the push bolt 13 in a direction orthogonal to the traveling direction of the wire. Although the mechanism for adjusting the position of the nipple 7 with the push bolt 13 has been described, it is only necessary that the nipple 7 can be aligned with the inner layer die 8, and the present invention is not limited to this.

  The inner layer die 8 has a substantially funnel shape and is held by the inner layer die holding portion 2d of the coating forming apparatus main body 2. The inner layer die 8 is formed with an inner layer die hole 8a for extruding the inner layer resin in a predetermined outer shape and a support wire hole 8b through which the support wire passes (see FIG. 1B). The outer diameter of the support wire hole 8b is slightly larger than the outer diameter of the support wire. On one side of the inner layer die 8 (on the downstream side in the direction of travel of the wire), there is a cylindrical guide portion 8c extending so as to surround the inner layer die hole 8a with a predetermined thickness in the direction of travel of the wire. It is extended.

  Further, when the inner layer die 8 is held by the inner layer die holding portion 2d of the coating forming apparatus main body 2, one side of the nipple 7 (downstream side in the traveling direction of the wire) and the other side of the inner layer die 8 (wire material) The first resin reservoir 15 is formed between the outer peripheral surface 8d of the inner layer die 8 and the second resin flow path portion 2e. A flow path 16 is formed.

  The outer layer die 10 has an outer diameter that is cylindrical, and is formed with an outer layer die hole 10a (see FIG. 3C). The outer layer die 10 is disposed in the outer layer die holding portion 2f of the coating forming apparatus main body 2, and is held by, for example, four push bolts 17 from the radial direction. The outer layer die 10 can be adjusted in position in a direction orthogonal to the traveling direction of the wire by adjusting the push bolt 17.

When the outer layer die 10 is arranged in the outer layer die holding portion 2f of the coating forming apparatus main body 2, one side of the inner layer die 8 (downstream side in the direction of travel of the wire) and the other side of the outer layer die 10 (wire material) A resin reservoir (second resin reservoir) 18 of the resin for the outer layer is formed with the upstream side in the traveling direction.
Although the mechanism for adjusting the position of the outer layer die 10 with the push bolt 17 has been described, it is only necessary that the position of the outer layer die 10 can be adjusted with respect to the inner layer die 8, and the present invention is not limited to this.

  A process of covering a wire with a two-layer jacket using the two-layer crosshead having the above-described configuration will be described. A wire rod (optical fiber core wire, two tension members, support wire) is inserted into each hole 7a, 7b, 7b, 7c of the nipple 7, and a predetermined arrangement position is regulated to a predetermined winding device side (not shown). Transport at a speed of As a result, the wire rods (optical fiber core wire, two tension members, support wires) are made of the nipple 7, the resin reservoir 15 for the inner layer resin, the die hole 8a for the inner layer and the support wire hole 8b, and the resin reservoir 18 for the outer layer resin. The outer die hole 10a is moved.

  Then, an inner layer resin, for example, a relatively hard nylon resin for facing, is poured into the first resin supply passage 11 by the inner layer extruder (not shown) into the coating molding apparatus 1 and an outer layer extrusion (not shown). The outer layer resin, for example, a flame retardant polyethylene resin is poured into the second resin supply path 12 by the machine.

  The resin for the inner layer flows through the first resin flow path 14 and is extruded in a predetermined shape from the inner layer extrusion hole 8a through the resin reservoir 15 for the inner layer resin (see FIG. 2B). Of the wires, the optical fiber and the two tension members pass through the nipples 7a, 7b, 7b, and are filled with the inner layer resin reservoir 15 with the inner layer resin, and then pass through the inner layer die hole 8a. As a result, an inner layer is formed.

Of the wire rod, the support wire passes through the nipple 7c and is filled with the inner layer resin in the inner layer resin reservoir 15. However, the outer diameter of the support wire hole 8b is slightly larger than the outer diameter of the support wire, and the coated resin for the inner layer is scraped off at the entrance of the support wire hole 8b. Yes. As a result, the support wire is not covered with the resin for the inner layer.
As described above, only the optical fiber and the two tension members can be covered with the resin for the inner layer.

  The outer layer resin flows through the second resin flow path 16 and is extruded from the outer layer extrusion hole 10a through the resin reservoir 18 of the outer layer resin. The wire (optical fiber and two tension members) on which the resin layer for the inner layer is formed and the support wire are passed through the inner layer die hole 8a, and then surrounded by the resin reservoir 18 for the outer layer resin. The outer layer is formed in a predetermined outer shape that is not similar to the inner layer by passing through the die hole 10a for the outer layer.

At this time , the resin layer for the inner layer formed around the optical fiber and the two tension members does not come into contact with the resin for the outer layer for a predetermined distance in the resin reservoir 18 for the outer layer resin by the guide portion 8c. In this way, the outer layer die 10 is guided while being protected. Thus, the layer of resin for the inner layer which is molded around the wire (optical fiber and two tension members), the pressure of the outer layer resin, it is possible to suppress the collapse of the shape.
Moreover, the optical cable (refer FIG. 3 (B)) by which the shape of the inner layer of an outer cover and an outer layer is an unsimilar shape can be manufactured according to the above process.

  A method of adjusting the position of the wire (optical fiber, tension member, support wire) will be described with reference to FIG. The wires (optical fiber and two tension members) that have passed through the nipple holes 7a, 7b, and 7b are covered with the resin for the inner layer in the resin reservoir 15 for the inner layer resin. At this time, the pressure of the resin for the inner layer In some cases, the inner layer die 8 is not fixed at a predetermined position with respect to the die hole 8a. In this case, by adjusting the nipple 7 using the push bolt 13, the wire is adjusted by aligning the core with the die hole 8 a of the inner layer die 8.

  A wire rod (optical fiber and two tension members) that passes through the inner layer die hole 8a and has an inner layer resin layer formed around it is covered with the outer layer resin reservoir 18 with the outer layer resin. However, at this time, it may not be determined at a predetermined position with respect to the die hole 10a of the outer layer die 10 due to the influence of the pressure of the outer layer resin. In this case, by adjusting the outer layer die 10 using the push bolts 17, the wire material is adjusted by aligning the core with the die hole 10 a of the outer layer die 10.

When the alignment is performed specifically, the eccentricity is examined by observing the cross section of the sample. Based on the result, the push bolts 13 and 17 are adjusted to adjust the position of the nipple 7 and the position of the outer layer die 10 with respect to the inner layer die 8.
As described above, the optical fiber core wire and the tension member can be arranged at predetermined positions even if the inner layer and the outer layer are extruded at a time.

  In the above description, both the nipple 7 and the outer layer die 10 have been described so as to be aligned with the inner layer die 8 by the adjusting mechanism. However, at least the outer layer die 10 can be aligned with the inner layer die 8. It ’s fine.

  Further, although the configuration has been described in which the coated resin for the inner layer is scraped off at the entrance of the support wire hole 8b, the present invention is not limited to this. For example, on the other side of the inner layer die 8 (upstream in the direction of travel of the wire), a cylindrical support line guide tube portion that prevents the support wire from coming into contact with the resin for the inner layer is placed on the nipple side opposite to the direction of travel of the wire. You may make it extend toward.

DESCRIPTION OF SYMBOLS 1 ... Cross head for 2 layers, 2 ... Cross head main body, 3 ... Base, 4 ... Support member, 5 ... Wire material holder, 6 ... Sleeve, 7 ... Nipple, 8 ... Die for inner layers (1st die), 8c DESCRIPTION OF SYMBOLS ... Guide part, 10 ... Outer layer die (second die), 11 ... First resin supply path, 12 ... Second resin supply path, 13 ... Push bolt, 14 ... First resin flow path, 15 ... Inner layer resin Resin reservoir (first resin reservoir), 16 ... second resin flow path, 17 ... push bolt, 18 ... resin reservoir for resin for outer layer (second resin reservoir).

Claims (3)

The optical fiber core wire and the tension member are arranged in parallel, and the body portion is coated and formed into two layers with the inner layer resin and the outer layer resin, and the suspension support wire portion is made of the outer layer resin with a narrow neck portion. A self-supporting type optical cable covering and molding apparatus integrally formed with the main body via
A first resin reservoir comprising a nipple and a first die to which the inner layer resin is supplied, and a second resin reservoir comprising the first die and a second die to which the outer layer resin is supplied. And comprising
The first die has an inner layer die hole through which the optical fiber core wire and the tension member pass, and a support wire hole through which the support line of the support wire portion passes,
The inner layer die hole guides the second die to guide the inner layer resin layer of the main body portion so as not to contact the outer layer resin in the second resin reservoir for a predetermined distance. Having a cylindrical guide portion extending to the side ,
The support wire hole has a diameter slightly larger than the outer diameter of the support wire so as to scrape off the resin for the inner layer coated on the support wire .   2. The self-supporting device according to claim 1, wherein at least the second die of the nipple and the second die is provided with a centering mechanism capable of aligning with the first die. Type optical cable coating molding equipment.   3. Using the self-supporting optical cable covering and molding apparatus according to claim 1 or 2, using a hard resin for anti-glare as the resin for the inner layer, and using a flame-retardant resin as the resin for the outer layer. A method of coating and forming a self-supporting optical cable characterized by the above.

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