JP2014109737A - Die device and method of manufacturing self-support type optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die device which can suppress resin pressure variation between neck part formation and slit formation while suppressing the waste amount of resin when providing slits intermittently in a length direction of a neck part, and also can suppress variation in shape and size of a cable.SOLUTION: A die device includes: a mouthpiece 40 provided successively with a main body part passage 42 forming a cable main body part, a neck part passage 43 forming a neck part, and a support wire part passage 41 forming a support wire; and a shutter 50 which can move in a direction orthogonal to the direction of succession of the main body part passage 42, neck part passage 43, and support wire part passage 41, and has a part with a first width SW1 and a part with a second width SW2 narrower than the first width SW1 in the direction of succession, a part of the neck part passage 43 being shielded with the part with the first width SW1 not to part the neck part passage 43 during neck part formation and the other part of the neck part passage 43 being shielded with the part with the second width SW2 to part the neck part passage 43.

Description

  The present invention relates to a die device and a method for manufacturing a self-supporting optical fiber cable.

  One type of optical fiber cable is a self-supporting optical fiber cable that is wired overhead. The self-supporting optical fiber cable is configured by connecting a cable main body portion and a support wire portion (hanging wire portion) at a neck portion. When manufacturing a self-supporting optical fiber cable, the cable body, neck, and support line are integrally formed by simultaneously extruding the optical fiber and support line (hanging line) through an extruder. To do.

  In such a self-supporting optical fiber cable, in order to improve the workability when separating the cable main body portion and the support wire portion, and to reduce the influence of wind pressure such as cross wind, it is intermittent in the longitudinal direction of the neck portion. In particular, a slit (opening) is provided. As a method for forming the slit, a method is known in which the resin in the neck discharged from the die of the extruder is dammed up using a pin or a shutter.

  In this method, when the resin is dammed up with a pin or a shutter at the time of slit formation, the cross-sectional area through which the resin of the die (die) is discharged decreases, thereby increasing the resin pressure in the die. On the other hand, the resin pressure is released when the shutter or pin is removed during neck formation, so that the shape and dimensions of the neck fluctuate or support is caused by the flow of resin from the high side to the low side. In some cases, resin shrinkage may occur in the wire portion or the cable body portion. As described above, the resin pressure fluctuates between the neck formation and the slit formation, whereby the shape and dimensions of the cable may fluctuate.

  Therefore, as a method of suppressing the resin pressure fluctuation at the time of neck formation and slit formation, when resin is dammed with a shutter to form a slit, there is a method of switching the dammed resin flow path and discharging it to the outside. It is known (for example, see Patent Documents 1 and 2).

Japanese Patent Application Laid-Open No. 8-27359 Japanese Patent No. 3712282

  However, in the methods described in Patent Documents 1 and 2, the dammed resin is discharged to the outside and becomes waste, which increases wasteful cost. In addition, since the resin flow path changes greatly, it is considered that the effect of suppressing the resin pressure fluctuation is weakened by receiving pressure loss and shearing due to bending of the resin flow path, the base wall surface, and the like.

  The object of the present invention is to suppress the resin pressure fluctuation between the neck formation and the slit formation while suppressing the amount of discarded resin when the slit is intermittently provided in the longitudinal direction of the neck. It is an object of the present invention to provide a die apparatus and a self-supporting optical fiber cable manufacturing method capable of suppressing variations in shape and dimensions.

  According to one aspect of the present invention, in a dice apparatus for manufacturing a self-supporting optical fiber cable in which a cable main body portion and a support wire portion are connected at a neck portion and slits are provided intermittently in the longitudinal direction of the neck portion. A base body passage forming a cable body portion, a neck passage forming a neck portion, and a base provided with a support wire portion passage forming a support line, a body portion passage, a neck passage, and a support wire portion. And a shutter having a first width portion and a second width portion narrower than the first width in the continuous direction. In order to prevent the neck passage from being divided in the moving direction of the shutter, a part of the neck passage is shielded by the first width portion, and when the slit is formed, the neck passage is separated from the neck passage in the moving direction of the shutter. Partly Die apparatus for shielding part of second width is provided.

  In one aspect of the present invention, it is preferable that the cross-sectional area of the neck passage blocked by the shutter when the neck is formed is equal to the cross-sectional area of the neck passage shielded by the shutter when forming the slit.

  In one embodiment of the present invention, the shutter has a first width, a pair of neck forming shielding portions that interlock with each other while maintaining a predetermined distance in the moving direction of the shutter, and a second width, A slit forming shield that is coupled to one of the pair of neck forming shields in the moving direction of the shutter and interlocks with the pair of neck forming shields, and the slit forming shield is connected to the neck passage when the neck is formed. The pair of neck forming shielding portions shields a part of the neck passage, and at the time of forming the slit, the pair of neck forming shielding portions retracts from the neck passage, and the slit forming shielding portion other than the neck passage. A part of may be shielded.

In one embodiment of the present invention, when the width of the neck is Nw, the predetermined interval between the pair of neck forming shielding portions is Ss, the first width is Sw1, and the second width is Sw2, the following formula

Sw1 (Nw−Ss) = Nw · Sw2 (where Nw> Ss)

It is preferable to satisfy the relationship.

  In one embodiment of the present invention, the shutter has a neck-forming shielding portion having a first width, and has a second width, and is connected to the neck-forming shielding portion in the moving direction of the shutter. And a slit forming shield that interlocks with the slit, the slit forming shield retracts from the neck passage when the neck is formed, and the neck forming shield shields a part of the neck passage and forms the neck when the slit is formed. The shielding portion for retraction may be withdrawn from the neck portion passage, and the slit forming shielding portion may shield another part of the neck portion passage.

In one aspect of the present invention, the width of the neck portion is Nw, the gap between the tip of the neck portion forming shielding portion and the end portion of the neck passage in the moving direction of the shutter at the time of neck formation is Ss, the first width is Sw1, and the second width When the width of Sw2 is Sw2,

Sw1 (Nw−Ss) = Nw · Sw2 (where Nw> Ss)

It is preferable to satisfy the relationship.

  In one embodiment of the present invention, the shutter has a pair of neck forming shields each having a first width and spaced apart from each other in the moving direction of the shutter, and a pair of neck forming shields having a second width. A slit-forming shield that can move independently from the head, and when the neck is formed, the slit-forming shield is retracted from the neck passage, and the pair of neck-forming shields shields part of the neck passage. At the time of slit formation, the pair of neck forming shielding portions may retreat from the neck passage in opposite directions, and the slit forming shielding portion may shield the other part of the neck passage.

  According to another aspect of the present invention, there is provided a method of manufacturing a self-supporting optical fiber cable in which a cable body portion and a support wire portion are connected at a neck portion, and slits are provided intermittently in the longitudinal direction of the neck portion, The main body passage that forms the cable main body provided in the base, the support wire passage that forms the support line, and the neck passage that forms the neck are movable in a direction orthogonal to the continuous direction, and are continuous. Using a shutter having a first width portion in the direction and a second width narrower than the first width, when forming the neck portion, a part of the neck passage is first formed so as not to divide the neck passage in the moving direction of the shutter. And a step of shielding the other part of the neck passage with the second width part so as to divide the neck passage in the moving direction of the shutter when the slit is formed. Optical fa Method for producing a bus cable is provided.

  According to the present invention, when the slits are intermittently provided in the longitudinal direction of the neck, the resin pressure fluctuation between the neck and the slit can be suppressed while suppressing the amount of discarded resin. It is possible to provide a die device and a self-supporting optical fiber cable manufacturing method capable of suppressing variations in shape and dimensions.

It is sectional drawing which shows an example of the self-supporting type optical fiber cable which concerns on embodiment of this invention. 1 is a perspective view showing an example of a self-supporting optical fiber cable according to an embodiment of the present invention. It is the schematic which shows an example of the manufacturing system of the self-supporting type optical fiber cable which concerns on embodiment of this invention. Fig.4 (a) is the schematic at the time of slit formation of the die apparatus which concerns on a comparative example. FIG.4 (b) is the schematic at the time of neck part formation of the die apparatus which concerns on a comparative example. It is the schematic at the time of neck formation of the dice apparatus concerning an embodiment of the invention. It is the elements on larger scale at the time of neck formation of the dice apparatus concerning an embodiment of the invention. It is the schematic at the time of slit formation of the dice apparatus concerning an embodiment of the invention. It is the elements on larger scale at the time of slit formation of the dice apparatus concerning an embodiment of the invention. It is the schematic at the time of neck formation of the dice apparatus concerning the 1st modification of an embodiment of the invention. It is the elements on larger scale at the time of neck part formation of the dice apparatus concerning the 1st modification of an embodiment of the invention. It is the schematic at the time of slit formation of the dice apparatus concerning the 1st modification of an embodiment of the invention. It is the elements on larger scale at the time of slit formation of the dice apparatus concerning the 1st modification of an embodiment of the invention. It is the elements on larger scale at the time of neck formation of the dice apparatus concerning the 2nd modification of an embodiment of the invention. It is the elements on larger scale at the time of slit formation of the dice apparatus concerning the 2nd modification of an embodiment of the invention. It is a schematic sectional drawing (sectional drawing of the BB direction of Drawing 16) at the time of neck formation of the dice device concerning the 3rd modification of an embodiment of the invention. It is a schematic sectional drawing (sectional view of AA direction of Drawing 15) at the time of neck formation of a dice device concerning the 3rd modification of an embodiment of the invention. It is a schematic sectional drawing (sectional view of the BB direction of Drawing 18) at the time of slit formation of a dice device concerning the 3rd modification of an embodiment of the invention. It is a schematic sectional drawing (sectional drawing of the AA direction of Drawing 17) at the time of slit formation of a dice device concerning the 3rd modification of an embodiment of the invention. It is a perspective view which shows an example of the self-supporting type optical fiber cable which concerns on other embodiment of this invention.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings. Further, the embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention includes the material, shape, structure, The layout is not specified as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

(Structure of self-supporting optical fiber cable)
As shown in FIG. 1, a self-supporting optical fiber cable according to an embodiment of the present invention includes a support wire portion 1, a cable body portion 2, and a neck portion 3 in which the support wire portion 1 and the cable body portion 2 are connected. Is provided.

  The support wire portion 1 includes a support wire 4 extending in the cable longitudinal direction and an outer sheath (sheath) 5 covering the support wire 4.

  The cable main body 2 includes a plurality of optical fibers 6, a press-wound tape 7 vertically attached in the cable longitudinal direction so as to cover the periphery of the plurality of optical fibers 6, and a jacket covering the periphery of the press-winding tape 7. (Sheath) 8.

  The plurality of optical fibers 6 are, for example, a collection of 24 optical fiber cores having a diameter of 0.25 mm. As the optical fiber 6, a core wire such as an optical fiber strand, an optical fiber core wire or an optical fiber tape core wire can be adopted. As the optical fiber ribbon, an intermittently fixed ribbon or the like can be used. In the embodiment of the present invention, the number of optical fibers 6 and the type of optical fibers 6 are not particularly limited. The plurality of optical fibers 6 may be stretched in parallel without being twisted in the longitudinal direction, may be twisted in one direction, may be twisted in an SZ shape, and may be twisted in one direction. You may hold | maintain the composite shape from which twisting changes in the middle. Further, a plurality of optical fiber units on which a plurality of optical fibers 6 are mounted may be mounted in the jacket 8.

  The material of the presser winding tape 7 is a thermoplastic resin such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or nylon (registered trademark), or thermosetting such as epoxy. Resin can be used.

  The outer cover 8 of the cable main body 2, the neck (outer cover) 3, and the outer cover 5 of the support wire portion 1 are integrally formed. As the material of the jackets 3, 5, and 8, resins such as polyvinyl chloride (PVC), polyethylene (PE), nylon (registered trademark), ethylene fluoride, or polypropylene (PP) can be used.

  A pair of tear strings (lip cords) 9 a and 9 b are embedded in the jacket 8 of the cable body 2 at positions facing each other with the optical fiber 6 interposed therebetween. The tear strings 9a and 9b are made of a twisted yarn made of polyester, a fiber string-like body such as an aramid fiber or glass fiber, or the like.

  A pair of strength members (tension members) 10a and 10b are disposed on the jacket 8 of the cable body 2 at positions facing each other with the optical fiber 6 interposed therebetween in a direction perpendicular to a straight line connecting the pair of tear strings 9a and 9b. Buried. The strength members 10a and 10b are made of a metal wire such as a steel wire, fiber reinforced plastic (FRP), or the like. The tensile bodies 10a and 10b are not limited to linear bodies, but may be strips. The band-like body is a long band-like one having a flat cross section, an elliptical shape, or a rectangular shape such as a rectangle.

  In the self-supporting optical fiber cable according to the embodiment of the present invention, as shown in FIG. 2, the neck portion 3 is formed intermittently (discontinuously), and the neck portion 3 is provided with a slit 11. By providing the slit 11, it is possible to improve workability when separating the cable main body portion 2 and the support wire portion 1 and to reduce the influence of wind pressure such as cross wind.

  Further, in the self-supporting optical fiber cable according to the embodiment of the present invention, the basis weight of resin (weight per unit area) in the cross section perpendicular to the cable longitudinal direction of the portion where the neck portion 3 is formed, and the slit 11 The basis weight of the resin in the cross section perpendicular to the cable longitudinal direction of the provided portion is substantially equal.

(Self-supporting optical fiber cable manufacturing system)
As shown in FIG. 3, the self-supporting optical fiber cable manufacturing system according to the embodiment of the present invention includes an optical fiber sending unit 21 for sending a plurality of optical fibers 6 and a presser winding for sending a presser winding tape 7. A tape sending unit 24, a collective twisting machine 22 that collects and twists together a plurality of optical fibers 6, a wire collecting jig 23 that collects the optical fibers 6, and tensile member sending units 26a and 26b that send the tensile members 10a and 10b, respectively. , Tear string sending sections 25a and 25b for sending the tear strings 9a and 9b, a support line sending section 27 for sending the support line 4, the support line 4, the plurality of optical fibers 6, the presser winding tape 7, and the tear string 9a, 9b, tensile strength members 10a, 10b are introduced, and an extruder 28 for extruding by covering the resin to form the outer jackets 3, 5, 8; a support wire sending part 27; and an extruder 28; Comprises a tensioning device 31 arranged in between.

  The extruder 28 introduces the support wire 4 and the plurality of optical fibers 6 and the like, and is attached to the crosshead 29 and the crosshead 29 for supplying the resin to become the jackets 3, 5, and 8. And a die device 30 that coats and extrudes a plurality of optical fibers 6 with a resin supplied from a crosshead 29.

  In addition, although the main structure was demonstrated in FIG. 3, of course, you may increase / decrease various structures as needed.

(Comparative example)
Here, a dice apparatus according to a comparative example will be described with reference to FIG. 4A and FIG. As shown in FIG. 4A, the dice apparatus according to the comparative example includes a base 100 and a shutter 104 that is provided on the resin discharge side of the base 100 and is movable up and down. The base 100 is provided with a hole for forming the support wire portion 101, a hole for forming the cable main body portion 102, and a hole for forming the neck portion 103.

  When forming a slit in the neck portion 103, as shown in FIG. 4A, the shutter 104 is raised to block the hole forming the neck portion 103, thereby blocking the resin in the neck portion 103.

  On the other hand, when forming the neck portion 103, as shown in FIG. 4B, the shutter 104 is lowered, and the hole forming the neck portion 103 is opened, thereby discharging the resin of the neck portion 103.

  Thus, the cross-sectional area from which the resin is discharged varies between the formation of the neck portion 103 and the slit formation, and the resin pressure varies. For this reason, as shown in FIG. 4B, when the hole forming the neck portion 103 is opened, the resin wire 201 or 202 is generated in the support wire portion 101 or the cable main body portion 102, and the shape of the cable. And dimensions may vary.

(Dice device)
As shown in FIG. 5, the dice apparatus 30 according to the embodiment of the present invention includes a base 40 and a plate-like shutter 50 provided on the resin discharge side of the base 40.

  In the base 40, a support line portion passage 41 that discharges the resin that forms the support line portion 1, a main body portion passage 42 that discharges the resin that forms the cable main body portion 2, the support line portion passage 41 and the main body portion passage 42. And a neck portion passage 43 for discharging the resin forming the neck portion 3. The support line portion passage 41, the main body portion passage 42, and the neck portion passage 43 extend linearly in parallel with each other at the land portion of the base 40.

  A driving unit 54 that drives the shutter 50 is connected to the shutter 50. The shutter 50 has a vertical direction in FIG. 5, that is, a linear direction connecting the center of the support line passage 41 and the center of the main body passage 42 (in other words, the main body passage 42, the neck passage 43, and the support line passage 41 are connected to each other). In a direction perpendicular to the continuous direction) and in a direction perpendicular to the extrusion direction.

  The shutter 50 may be movable in an oblique direction with respect to a direction in which the main body passage 42, the neck portion passage 43, and the support wire portion passage 41 are continuous, or may be movable in an oblique direction with respect to the extrusion direction. May be. Further, the shutter 50 may be disposed in contact with the surface of the base 40 so as to slide on the surface of the base 40, may be disposed away from the surface of the base 40, or is embedded in the base 40. May be.

  The shutter 50 has a first width SW1 portion and a second width SW2 portion narrower than the first width SW1 in a direction orthogonal to the moving direction of the shutter 50. When the neck portion 3 is formed, the shutter 50 shields a part of the neck passage 43 with the first width SW1 so as not to divide the neck passage 43 in the moving direction of the shutter 50. In addition, when the slit 11 is formed, the shutter 50 shields a part of the neck passage 43 with the second width SW2 so as to divide the neck passage 43 in the moving direction of the shutter 50.

  In the embodiment of the present invention, each shutter 50 has a first width Sw1, and has a pair of neck forming shielding portions 51 and 53 that interlock with each other while maintaining a predetermined distance, and a second width Sw2. And a slit-forming shielding portion 52 that is coupled to the neck-forming shielding portion 51 in the moving direction of the shutter 50 and interlocks with the pair of neck-forming shielding portions 51, 53.

  When the neck 3 is formed, as shown in FIGS. 5 and 6, the shutter 50 is raised, the slit forming shield 52 is retracted from the neck passage 43, and the pair of neck forming shields 51, 53 are Without dividing the neck passage 43, the main body passage 42, the neck passage 43, and the support wire passage 41 are continuously connected to shield a part of the neck passage 43, and a part of the resin discharged from the neck passage 43 is blocked. Dam up.

  On the other hand, when forming the slit 11, as shown in FIGS. 7 and 8, the shutter 50 is lowered to retract the pair of neck portion forming shielding portions 51, 53 from the neck passage 43 and to form the slit forming shielding portion 52. Shields a part of the neck passage 43 so as to divide the main body passage 42 and the support wire portion passage 41 (in other words, so as to divide the neck passage 43 in the moving direction of the shutter 50). A part of the resin discharged from the dam is dammed up.

  In the embodiment of the present invention, the cross-sectional area from which the resin is discharged from the neck passage 43 when the neck 3 shown in FIGS. 5 and 6 is formed, and the neck passage 43 when the slit 11 shown in FIGS. 7 and 8 is formed. It is preferable to make the cross-sectional area from which the resin is discharged equal from the viewpoint of suppressing the resin pressure fluctuation. In other words, the cross-sectional area of the neck passage 43 that is shielded by the pair of neck-forming shielding portions 51 and 53 when the neck portion 3 is formed, and the neck passage 43 that is shielded by the slit-forming shielding portion 52 when the slit 11 is formed. The cross-sectional area is preferably equal.

  That is, the width Nw of the neck portion 3 shown in FIGS. 6 and 8, the distance Ss between the pair of neck portion forming shielding portions 51 and 53, the first width Sw <b> 1, and the second width Sw <b> 2 satisfy the relationship of the following formula. It is preferable that it is prescribed | regulated.

Sw1 (Nw−Ss) = Nw · Sw2 (where Nw> Ss)

In addition, as the shutter 50, the configuration in which the pair of neck-forming shielding parts 51 and 53 and the slit-forming shielding part 52 are connected in an annular shape and driven by one driving part 54 has been described. The slit forming shielding part 52 and the neck part forming shielding part 53 may be interlocked by different driving parts.

(Manufacturing method of self-supporting optical fiber cable)
Next, an example of a method for manufacturing a self-supporting optical fiber cable according to an embodiment of the present invention will be described.

  (A) As shown in FIG. 3, the optical fiber sending unit 21 sends out a plurality of optical fibers 6. The collective twisting machine 22 aggregates a plurality of optical fibers 6 and twists the plurality of optical fibers 6 in one direction or the SZ direction. The wire collecting jig 23 collects a plurality of optical fibers 6.

  (B) The presser winding tape sending unit 24 sends the presser winding tape 7. The strength member sending units 26a and 26b send the strength members 10a and 10b. The tear string sending sections 25a and 25b send the tear strings 9a and 9b. Then, the bundle of optical fibers 6 to which the press-wound tape 7 is vertically attached is introduced into the extruder 28 together with the strength members 10a and 10b and the tear strings 9a and 9b. Further, the support wire sending unit 27 sends the support wire 4. The support wire 4 is introduced into the extruder 28 in parallel with the bundle of optical fibers 6 while applying a predetermined tension using the tension applying device 31 so that the cable body 2 is slackened.

  (C) The extruder 28 performs extrusion molding so as to integrally form the jackets 5 and 8 and the neck 3 of the cable body 2 and the support wire 1 shown in FIG. Here, when the neck portion 3 is formed, as shown in FIGS. 5 and 6, the shutter 50 is raised, the slit forming shielding portion 52 is retracted from the neck portion passage 43, and the main body portion passage 42 and the support line portion passage are provided. In a state where 41 is continuous, the pair of neck portion forming shielding portions 51 and 53 block a part of the neck passage 43 and block a part of the resin discharged from the neck passage 43. On the other hand, when forming the slit 11, as shown in FIGS. 7 and 8, the shutter 50 is lowered to retract the pair of neck portion forming shielding portions 51, 53 from the neck passage 43 and to form the slit forming shielding portion 52. Then, a part of the neck passage 43 is closed so as to divide the main body passage 42 and the support wire portion passage 41, and a part of the resin discharged from the neck passage 43 is blocked.

  (D) The cable 10 after passing through the extruder 28 shown in FIG. 3 is cooled by a water tank or the like (not shown), and the jackets 5 and 8 and the neck 3 of the cable body 2 and the support wire 1 are cured. . It winds up with the winder which abbreviate | omitted illustration.

  According to the self-supporting optical fiber cable manufacturing method using the self-supporting optical fiber cable manufacturing system having the dice device 30 according to the embodiment of the present invention, the neck 3 is formed and the slit 11 is formed. By damming a part of the neck passage 43 at the part of the first width Sw1 and the part of the second width Sw2, the resin pressure fluctuation at the time of forming the neck part 3 and the slit 11 can be suppressed, It is possible to realize a self-supporting optical fiber cable that can suppress variations in the shape and dimensions of the cable.

(Example)
As an example of the self-supporting optical fiber cable according to the embodiment of the present invention, the height Nh of the neck 3 shown in FIGS. 6 and 8 is 2.0 mm, the width Nw of the neck 3 is 4.0 mm, A self-supporting optical fiber cable was prototyped with a width Sw1 of 2.0 mm, a second width Sw2 of 0.75 mm, and a distance Ss between the pair of neck forming shielding portions 51 and 53 of 2.5 mm.

  When the prototyped self-supporting optical fiber cable was visually observed, it was confirmed that the cable main body 2 and the support wire portion 1 were suppressed in resin shrinkage and resin fluctuation and had a good shape.

  In addition, regarding the prototyped self-supporting optical fiber cable, the area of the resin (resin cross-sectional area) in the cross section perpendicular to the cable longitudinal direction of the region where the neck 3 is formed and the region where the slit 11 is formed is measured with a microscope. It was measured. As a result, it was confirmed that the resin cross-sectional areas of the region where the neck portion 3 was formed and the region where the slit 11 was formed were substantially the same.

(First modification)
Another example of the shutter 50 of the die device 30 of the extruder 28 will be described as a first modification of the embodiment of the present invention. As shown in FIGS. 9 and 10, the shutter 50 according to the first modification of the embodiment of the present invention has a neck portion forming shielding portion 51 having a first width Sw1 and a second width Sw2. In addition, there is a slit-forming shielding portion 52 that is connected to the neck-forming shielding portion 51 in the moving direction of the shutter 50 and interlocks with the neck-forming shielding portion 51.

  When the neck 3 is formed, the shutter 50 is lowered as shown in FIGS. 9 and 10, the slit forming shielding part 52 is retracted from the neck passage 43, and the support line portion passage 41 and the main body portion passage 42 are continuous. In this state, the neck forming shielding portion 51 blocks a part of the neck passage 43 to block a part of the resin discharged from the neck passage 43.

  On the other hand, when the slit 11 is formed, the shutter 50 is lifted as shown in FIGS. 11 and 12, the neck portion forming shielding portion 51 is retracted from the neck portion passage 43, and the slit forming shielding portion 52 is moved to the main body portion passage 42. A part of the resin discharged from the neck passage 43 is blocked by closing a part of the neck passage 43 so as to divide the support line passage 41 and the support wire passage 41.

  The cross-sectional area from which the resin in the neck passage 43 is discharged when the neck 3 shown in FIG. 10 is formed is equal to the cross-sectional area from which the resin in the neck passage 43 is discharged when the slit 11 shown in FIG. 12 is formed. The resin pressure fluctuation can be further suppressed, which is preferable.

  That is, the width Nw of the neck 3, the distance Ss between the tip of the neck forming shield 51 and the end of the neck passage 43 in the moving direction of the shutter 50, the first width Sw 1, and the second width Sw 2 are expressed by the following formulas: It is preferable to be defined so as to satisfy the relationship.

Sw1 (Nw−Ss) = Nw · Sw2 (where Nw> Ss)

According to the first modification of the embodiment of the present invention, even when the shutter 50 shown in FIGS. 9 to 12 is used, the neck 3 is formed and the slit 11 is formed as in the embodiment of the present invention. By damming a part of the neck passage 43 with the first width Sw1 and the second width Sw2 at the time of forming, the resin pressure fluctuation at the time of forming the neck 3 and the slit 11 is suppressed. Therefore, it is possible to realize a self-supporting optical fiber cable that can suppress variations in the shape and dimensions of the cable.

(Second modification)
Another example of the shutter 50 of the die device 30 of the extruder 28 will be described as a second modification of the embodiment of the present invention. In the shutter 50 according to the second modification of the embodiment of the present invention, as shown in FIG. 13, the neck portion forming shielding portion 51 has the same first width Sw <b> 1 as the height Nh of the neck portion passage 43. Is different. The second width Sw2 of the slit-forming shielding part 52 is shown in FIGS. 9 to 12 so that the cross-sectional areas from which the resin is discharged are equal when the slit 11 is formed and when the neck part 3 is formed. It is wider than the second width Sw2.

  When the neck 3 is formed, as shown in FIG. 13, the shutter 50 is lowered to open the neck passage 43 in a rectangular shape, and the neck forming shielding portion 51 closes a part of the neck passage 43 to close the neck passage. Part of the resin discharged from 43 is dammed up.

  On the other hand, when the slit 11 is formed, the resin discharged from the neck passage 43 is divided by raising the shutter 50 and closing a part of the neck passage 43 with the slit forming shielding portion 52 as shown in FIG. Dam up as you do.

  According to the second modification of the embodiment of the present invention, even when the shutter 50 shown in FIGS. 13 and 14 is used, as in the embodiment of the present invention, the neck 3 is formed and the slit 11 is formed. By damming a part of the neck passage 43 with the first width Sw1 and the second width Sw2 at the time of forming, the resin pressure fluctuation at the time of forming the neck 3 and the slit 11 is suppressed. Therefore, it is possible to realize a self-supporting optical fiber cable that can suppress variations in the shape and dimensions of the cable.

(Third Modification)
Another example of the die device 30 of the extruder 28 will be described as a third modification of the embodiment of the present invention.

  As shown in FIGS. 15 and 16, a shutter 50x according to a third modification of the embodiment of the present invention has first widths SW4 and SW5, respectively, and a pair separated from each other in the moving direction of the shutter 50x. And a slit forming shield 56 having a second width SW6 and movable independently of the pair of neck forming shields 54, 55.

  As shown in FIG. 16, the base 40 has a tapered portion to which the resin 45 is supplied between the nipple 44 and a land portion that is continuous with the tapered portion and into which the resin 45 is introduced. A main body passage 42, a neck passage 43, and a support wire passage 41 shown in FIG. 15 are provided in the land portion of the base 40. A groove portion for the shutter 50x is provided in the land portion of the base 40, and a pair of neck portion forming shielding portions 54 and 55 and a slit forming shielding portion 56 are movably disposed in the groove portion.

  When the neck 3 is formed, as shown in FIGS. 15 and 16, the slit forming shield 56 is retracted from the neck passage 43, and the pair of neck forming shields 54, 55 occupies part of the neck passage 43. Shield. 15 and 16 show the case where the position of the tip of the slit forming shield 56 matches the position of the tip of the neck forming shield 55, but the position of the tip of the slit forming shield 56 is the neck. There is no particular limitation as long as it is retracted from the tip of the forming shielding portion 55.

  On the other hand, when the slit 11 is formed, as shown in FIGS. 17 and 18, the pair of neck-forming shielding portions 54 and 55 are retracted from the neck passage 43 in the opposite directions, and the slit-forming shielding portion 56 is the neck passage. A part of 43 is shielded. Here, from the viewpoint of suppressing resin pressure fluctuation at the time of forming the neck portion 3 and at the time of forming the slit 11, the cross-sectional area of the neck passage 43 shielded by the pair of neck portion forming shielding portions 54 and 55, and the slit forming shielding portion. It is preferable that the cross-sectional areas of the neck passage 43 shielded by 56 are equal.

  According to the third modification of the embodiment of the present invention, even when the shutter 50x is provided in the land portion of the base 40, as in the embodiment of the present invention, the neck 3 is formed and the slit 11 is formed. It is possible to realize a self-supporting optical fiber cable that can suppress resin pressure fluctuations at the time and can suppress fluctuations in the shape and dimensions of the cable.

  The slit forming shielding portion 56 is provided at a position overlapping the neck forming shielding portion 55, but may be provided at a position overlapping the neck forming shielding portion 54.

  Further, the slit forming shielding part 56 is provided on the outlet side of the base 40 with respect to the neck forming shielding part 55, but may be provided on the inlet side of the base 40 with respect to the neck forming shielding part 55. .

(Other embodiments)
As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the embodiment of the present invention, a self-supporting optical fiber cable having a linear cable body 2 as shown in FIG. 2 has been described as an example. However, as shown in FIG. The present invention can also be applied to a self-supporting optical fiber cable having a surplus length and having a surplus length. A self-supporting optical fiber cable with a surplus length can be realized by making the amount of pulling out of the cable body portion 2 larger than the amount of pulling out of the supporting wire portion 1 when pulling out from the extruder 28.

  Further, in the shutter 50 shown in FIG. 5, the case where the pair of neck portion forming shielding portions 50 and 53 have the same first width Sw1 has been described. However, the pair of neck portion forming shielding portions 50 and 53 have different widths. You may have. Further, in the shutter 50x shown in FIG. 15, the case where the first widths SW4 and SW5 of the pair of neck portion forming shielding portions 54 and 55 are the same has been described, but the widths of the neck portion forming shielding portions 54 and 55 are different. May be.

  Further, in the embodiment of the present invention, the case where the shutter 50 slides on the surface of the base 40 has been described. However, a concave portion may be provided on the surface of the base 40 and the shutter 50 may move in the concave portion. A shutter passage may be provided inside the shutter 50, and the shutter 50 may move in the shutter passage.

  The shape of the shutter 50 is not particularly limited as long as the cross-sectional area of the neck passage 43 that is shielded when the neck portion 3 is formed is equal to the cross-sectional area of the neck passage 43 that is shielded when the slit 11 is formed. For example, in the shutter 50 shown in FIG. 5, the pair of neck forming shields 50 and 53 may be triangular or circular.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Support wire part 2 ... Cable main-body part 3 ... Outer jacket (neck part)
DESCRIPTION OF SYMBOLS 4 ... Support wire 5, 8 ... Outer sheath 6 ... Optical fiber 7 ... Pressing winding tape 9a, 9b ... Tear string 10 ... Self-supporting type optical fiber cable 10a, 10b ... Strength member 11 ... Slit 21 ... Optical fiber delivery part 22 ... Aggregate twister 23 ... Concentration jig 24 ... Press-wound tape delivery part 25a, 25b ... Tear string delivery part 26a, 26b ... Tensile body delivery part 27 ... Support wire delivery part 28 ... Extruder 29 ... Crosshead 30 ... Dice device 31 ... Tension applying device 40 ... Die
DESCRIPTION OF SYMBOLS 41 ... Support line part channel | path 42 ... Main-body part channel | path 43 ... Neck part channel | path 44 ... Nipple 45 ... Resin 50, 50x ... Shutter 51, 53, 54, 56 ... Neck part formation shielding part 52, 55 ... Slit formation shielding part 54 ... Drive part

Claims (8)

A die device for manufacturing a self-supporting optical fiber cable in which a cable main body part and a support line part are connected at a neck part, and slits are provided intermittently in the longitudinal direction of the neck part,
A base body passage forming the cable body portion, a neck passage forming the neck portion, and a base provided continuously with a support wire portion passage forming the support line;
The main body passage, the neck passage, and the support line passage are movable in a direction perpendicular to the continuous direction, and the first width portion and the first width narrower than the first width in the continuous direction. A shutter having a width of 2;
When forming the neck portion, a portion of the neck passage is shielded by the first width portion so as not to divide the neck passage in the moving direction of the shutter,
A die apparatus characterized in that when the slit is formed, another part of the neck passage is shielded by the second width portion so as to divide the neck passage in the moving direction of the shutter.   2. The dice apparatus according to claim 1, wherein a cross-sectional area of the neck passage blocked by the shutter when the neck is formed is equal to a cross-sectional area of the neck passage shielded by the shutter when the slit is formed. The shutter is
A pair of neck-forming shielding portions each having the first width and interlocking with each other while maintaining a predetermined interval in the moving direction of the shutter;
A slit forming shielding portion having the second width, connected to one of the pair of neck portion forming shielding portions in the moving direction of the shutter, and interlocking with the pair of neck portion forming shielding portions;
When the neck portion is formed, the slit forming shielding portion is retracted from the neck passage, and the pair of neck forming shielding portions shields part of the neck passage,
The pair of neck-forming shielding portions are retracted from the neck passage when the slit is formed, and the slit-forming shielding portions shield other parts of the neck passage. The dice apparatus as described in. When the width of the neck is Nw, the predetermined interval between the pair of neck-forming shielding portions is Ss, the first width is Sw1, and the second width is Sw2, the following formula

Sw1 (Nw−Ss) = Nw · Sw2 (where Nw> Ss)

The die device according to claim 3, wherein the relationship is satisfied. The shutter is
A neck forming shield having the first width;
A slit forming shielding portion having the second width, connected to the neck forming shielding portion in the moving direction of the shutter, and interlocking with the neck forming shielding portion;
When the neck is formed, the slit forming shielding part is retracted from the neck passage, and the neck forming shielding part shields a part of the neck passage,
The said neck part formation shielding part retracts | saves from the said neck part channel | path at the time of the said slit formation, and the said slit formation shielding part shields another part of the said neck part channel | path. Dice equipment. The width of the neck is Nw, the gap between the tip of the neck forming shield and the end of the neck passage in the moving direction of the shutter when the neck is formed is Ss, the first width is Sw1, and the second When the width of Sw2 is Sw2,

Sw1 (Nw−Ss) = Nw · Sw2 (where Nw> Ss)

The die device according to claim 5, wherein the relationship is satisfied. The shutter is
A pair of neck-forming shielding portions each having the first width and spaced apart from each other in the moving direction of the shutter;
A slit-forming shielding part having the second width and movable independently of the pair of neck-forming shielding parts;
When the neck portion is formed, the slit forming shielding portion is retracted from the neck passage, and the pair of neck forming shielding portions shields part of the neck passage,
The pair of neck-forming shielding portions retracts from the neck passage in opposite directions when the slit is formed, and the slit-forming shielding portion shields the other part of the neck passage. Item 3. The die apparatus according to Item 1 or 2. A cable body part and a support line part are connected by a neck part, and a manufacturing method of a self-supporting optical fiber cable in which slits are provided intermittently in the longitudinal direction of the neck part,
It is movable in a direction orthogonal to the direction in which the main body passage that forms the cable main body provided in the base, the support wire passage that forms the support wire, and the neck passage that forms the neck portion is continuous. Using a shutter having a first width portion in the continuous direction and a second width narrower than the first width,
Shielding the part of the neck passage with the first width portion so as not to divide the neck passage in the moving direction of the shutter when the neck is formed;
Shielding the other part of the neck passage with the second width portion so as to divide the neck passage in the moving direction of the shutter when the slit is formed. Manufacturing method of optical fiber cable.

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