JP4736848B2 - Cable manufacturing method - Google Patents

Description

  The present invention relates to a cable manufacturing method for manufacturing a cable covered with a jacket.

As a power transmission / communication cable, a resin made of a thermoplastic resin or the like is coated on the outer periphery of a linear member such as an electric wire or an optical fiber core wire for insulation and protection.
In order to manufacture a cable coated with this type of resin, extrusion is performed by covering the linear member with the resin filled in the die by passing the linear member guided by the nipple through the die. .
Here, a technique is known in which a plurality of nipples that respectively guide a plurality of linear members are held by a nipple holder, and the positions of the nipple holders are adjusted to adjust the mutual distance between the linear members (for example, patents). Reference 1).
It is also known to measure the film thickness of the covering of the linear member with a sensor and adjust the relative position of the nipple and the die with a fine movement mechanism so as to absorb the uneven thickness of the film thickness based on the measurement result. (For example, refer to Patent Document 2).

JP-A-5-135638 JP 2000-90756 A

In the technique of the above-mentioned Patent Document 1, it is possible to facilitate the operation of adjusting the position of the linear member in the finished cable by adjusting the position of the nipple holder, but the cross section of the extruded cable is observed. Therefore, it is necessary to check the bias of the linear body and to adjust the position of the nipple holder based on the result.
Moreover, in the technique of the above-mentioned Patent Document 2, it is possible to measure the deviation of a single linear member, but it is not possible to measure the deviation of a plurality of linear members, so a cable that covers a plurality of linear members. It was unsuitable for position adjustment when manufacturing.

  Then, this invention aims at providing the manufacturing method of the cable which can position the linear member easily and can manufacture the cable which coat | covered the several linear member with resin.

  A cable manufacturing method according to the present invention that can solve the above-mentioned problems is a method of holding a nipple for guiding a plurality of linear members and a die having a die hole through which resin is extruded together with the linear members from the nipple. A cable manufacturing method for manufacturing a cable in which a plurality of linear members are coated with a resin by a crosshead that has a cross-sectional shape that approximates the shape of a die hole of the die at a tip portion, and Use a position adjustment jig that has the same shape as the nipple except for the tip, and fix the position adjustment jig at the nipple fixing position with respect to the die holder before the cable is extruded by the cross head. And the die holder at the position where the protruding portion of the position adjusting jig is inserted into the die hole of the die. Fixed, characterized by fixing the nipple to the position adjustment jig in the nipple fixed position relative to the die holder removed from the die holder.

  According to the cable manufacturing method of the present invention, the die is fixed to the die holder in a state where the position adjusting jig having the protruding portion having a cross-sectional shape approximate to the shape of the die hole of the die is once fixed at the nipple fixing position. After the positioning, the position adjustment jig is removed and the nipple is fixed at the nipple fixing position, so that the relative position between the nipple and the die is accurately positioned. Therefore, a cable in which a plurality of linear members are covered with a resin can be manufactured by easily positioning the linear members.

Hereinafter, an example of an embodiment of a cable manufacturing method according to the present invention will be described with reference to the drawings.
1 is a cross-sectional view of a cable manufactured according to the present embodiment, FIG. 2 is a schematic configuration diagram illustrating a cable manufacturing apparatus manufactured according to the present embodiment, and FIG. 3 is a cross-sectional view illustrating a crosshead to which the present embodiment is applied. 4 and 4 are front views of the crosshead of FIG.
First, the cable manufactured in this embodiment will be described. In the present embodiment, an optical fiber cable having an optical fiber will be described as an example.
As shown in FIG. 1, an optical fiber cable (cable) 1 is composed of a single optical fiber core (linear member) 2 and two strength members disposed so as to sandwich the optical fiber core 2 at substantially the center. (Linear member) 3 and steel support wire (linear member) 4 are coated with a coating resin 5, a main body portion 6 having an optical fiber core 2, and a messenger wire portion 7 having a support wire 4. Are connected by a neck portion 8 made of a coating resin 5.

This optical fiber cable 1 is a drop cable used for applications such as FTTH (Fiber To The Home), and by separating the main body portion 6 having the optical fiber core wire 2 from the messenger wire portion 7 at the neck portion 8, The main body 6 can be easily pulled into the building from an imaginary pole such as a utility pole.
The optical fiber cable 1 has notches 9 formed on both sides of the main body 6. By tearing the coating resin 5 at the notches 9, the internal optical fiber 2 can be easily taken out. be able to.

Next, a manufacturing apparatus for manufacturing the optical fiber cable 1 will be described.
As shown in FIG. 2, the manufacturing apparatus 11 includes a collective covering portion 13 including an extruder 18.

The tensile body 3 fed out from the tensile body supply reel 21, the optical fiber core wire 2 fed out from the optical fiber core supply reel 22 and the support wire supply reel 23, and the support wire 4 are fed into the collective covering portion 13, and an extrusion molding machine The coating resin 5 is coated by extrusion molding at 18, cooled by the cooling device 19, and sent out.
Then, the optical fiber cable 1 integrated with the coating resin 5 in the collective covering portion 13 is taken up by the take-up device 24 and taken up on the take-up reel 25.
Here, in order to enhance the adhesion between the tensile body, the support wire and the coating resin, when using a thin resin adhesive layer provided on the surface in advance, a step of heating before being supplied to the extrusion molding machine 18 is performed. May be provided.

Next, the extrusion molding machine 18 of the collective coating portion 13 that extrudes the resin together with the tensile body 3, the optical fiber core wire 2, and the support wire 4 to coat the coating resin 5 will be described.
As shown in FIG. 3, the extruder 18 includes an extruder 31 and a crosshead 32. The extruder 31 includes a heating cylinder 33 and a screw 34. The screw 34 is rotated to increase the pressure in the heating cylinder 33, and a resin (not shown) that becomes the coating resin 5 is softened to cross the head 32. Push into the inside.

  The cross head 32 includes a cylindrical die holder 35, and a cylindrical nipple holder 36 is inserted into the die holder 35 from the rear side. The nipple holder 36 is formed with a locking step portion 36 a in the vicinity of the tip thereof by making the rear end side large in diameter. When the nipple holder 36 is inserted into the die holder 35, the locking step portion 36 a is connected to the die holder 35. Is engaged with an engaging projection 35a formed on the inner peripheral surface of the member, and positioning in the axial direction is performed. Further, the nipple holder 36 and the die holder 35 are provided with a key and a key groove (not shown) that engage with each other by inserting the nipple holder 36 into the die holder 35 and perform positioning in the direction around the axis.

  A hollow resin supply channel 37 is formed between the tip side of the nipple holder 36 and the die holder 35. The die holder 35 is formed with a resin supply port 38 communicating with the heating cylinder 33 and the resin supply channel 37, and the resin supplied by the extruder 31 is supplied from the resin supply port 38 to the resin supply channel 37. It is configured to be introduced.

  Further, the nipple holder 36 holds a cylindrical nipple 41 at its tip, and a die 42 is held at the tip of the die holder 35. The outer diameter of the die 42 is formed to be smaller than the inner diameter at the tip end side of the die holder 35, so that the die 42 can move in the direction intersecting the axis in the die holder 35. Yes. A gap 43 is provided between the die 42 and the nipple 41, and the resin supplied to the resin supply channel 37 is also introduced into the gap 43.

  As shown also in FIG. 4, the nipple 41 has an optical fiber core wire introduction hole 41a, a strength member introduction hole 41b, and a support wire introduction hole 41c on its tip surface, and these optical fiber core wire introduction holes 41a. The optical fiber core wire 2, the strength member 3 and the support wire 4 are inserted through the strength member introduction hole 41b and the support wire introduction hole 41c, respectively.

  The nipple 41 is formed at its rear end with a locking protrusion 41d protruding toward the outer peripheral side along the circumferential direction. Further, the nipple holder 36 is formed with an engaging step portion 36b by making the inner diameter at the tip portion small. When the nipple 41 is inserted from the rear end side of the nipple holder 36, the locking protrusion 41 d of the nipple 41 is engaged with the engagement step portion 36 b of the nipple holder 36, and the nipple 41 is pivoted with respect to the nipple holder 36. Positioned in the direction. The nipple 41 and the nipple holder 36 are provided with a key and a key groove (not shown) that engage with each other by positioning the nipple 41 into the nipple holder 36 and perform positioning in the direction around the axis.

  The die 42 is formed with a die hole 42a formed in a cross-sectional shape of the optical fiber cable 1 to be molded. In the die hole 42a, the optical fiber core wire introduction hole 41a, the strength member introduction hole 41b, and the support wire introduction hole 41c of the nipple 41 are arranged in a plan view, thereby introducing these optical fiber core wires. The optical fiber core wire 2, the tensile member 3 and the support wire 4 led out from the hole 41a, the strength member introduction hole 41b and the support wire introduction hole 41c are drawn out from the die hole 42a.

The die holder 35 has a detachable flange portion 35b that protrudes toward the inner peripheral side in the circumferential direction at the tip portion, and the flange portion 35b has four flange portions that are equally spaced in the circumferential direction. An insertion hole 35c is formed.
On the other hand, the die 42 is formed with a screw hole 42b communicating with the insertion hole 35c on the surface facing the flange portion 35b, and the fixing bolts 44 inserted into the insertion holes 35c of the flange portion 35b are screwed respectively. It is screwed into the hole 42b.

The insertion hole 35c is formed to have a larger diameter than the fixing bolt 44, and the die 42 is moved in the direction around the axis and the direction intersecting the axis in a temporarily fixed state in which the fixing bolt 44 is lightly screwed into the die 42. It can be made to.
Further, four screw holes 35d are formed in the vicinity of the tip of the die holder 35 at equal intervals in the circumferential direction toward the center, and positioning bolts 45 are screwed into the screw holes 35d from the outer peripheral side, respectively. The tip ends of the positioning bolts 45 are in contact with the outer peripheral surface of the die 42.

  A tool recess 42c is formed on the end face of the die 42. By inserting and operating a tool in the tool recess 42c, the die 42 is moved in the direction around the axis or intersecting the axis. Be able to.

  In the extruder 18 configured as described above, the thermoplastic resin fed from the extruder 31 through the resin supply port 38 to the resin supply flow path 37 and the gap 43 between the die 42 and the nipple 41 is converted into the light of the nipple 41. The optical fiber core wire 2, the tensile body 3 and the support wire 4 inserted through the fiber core wire introduction hole 41 a, the strength member introduction hole 41 b and the support wire introduction hole 41 c are pushed out from the die hole 42 a of the die 42. Thereby, the optical fiber cable 1 in which the coating resin 5 is coated on the optical fiber core wire 2, the tensile body 3, and the support wire 4 and is formed in the cross-sectional shape of the die hole 42a is extruded.

Next, a method for positioning the nipple 41 and the die 42 before the extrusion molding in the cross head 32 of the extruder 18 having the above structure will be described.
5 to 9 are diagrams showing a procedure for positioning the nipple and the die. FIG. 5 is a sectional view of the nipple holder, and FIGS. 6A and 6B are a side view and a front view showing the position adjusting jig. 7 is a cross-sectional view of the crosshead, FIG. 8 is a front view of the crosshead, and FIG. 9 is a cross-sectional view of the crosshead.

(1) First, as shown in FIG. 5, the position adjusting jig 51 is attached to the nipple holder 36. As shown in FIG. 6A, the position adjusting jig 51 has projecting portions 52 and 53 at the distal end portion, and the nipple 41 has other portions other than the distal end portion having the projecting portions 52 and 53. And the same shape. That is, the position adjusting jig 51 has the same outer diameter as that of the nipple 41, and a locking protrusion 51 a that protrudes to the outer peripheral side along the circumferential direction is formed at the rear end portion.

  When the position adjusting jig 51 is inserted from the rear end side of the nipple holder 36, the locking protrusion 51 a of the position adjusting jig 51 is engaged with the engaging step portion 36 b of the nipple holder 36. On the other hand, the position adjusting jig 51 is positioned in the axial direction. Further, the position adjusting jig 51 and the nipple holder 36 include a key and a key groove (not shown) that engage with each other by inserting the position adjusting jig 51 into the nipple holder 36 and perform positioning in the direction around the axis. Yes.

  As shown in FIG. 6B, the projecting portions 52 and 53 of the position adjusting jig 51 have a cross-sectional shape that approximates a part of the shape of the die hole 42 a of the die 42. . Specifically, the protrusion 52 is formed in a shape that approximates a partial cross-sectional shape of a portion of the die hole 42a through which the support line 4 passes, and the protrusion 53 is located on the outer side of the die hole 42a. It is formed in a shape that approximates the cross-sectional shape along the portion through which the strength member 3 passes. It should be noted that one protruding portion formed in a cross-sectional shape that approximates the entire shape of the die hole 42a may be formed.

(2) When the position adjusting jig 51 is attached to the nipple holder 36, as shown in FIG. 7, the nipple holder 36 is engaged from the rear side of the die holder 35 until the locking step 36a is locked to the locking projection 35a. The position adjustment jig 51 is fixed at a fixed position of the nipple 41 (a nipple fixing position) by inserting and mounting the key and the key groove in a state where the positioning around the axis is performed.

(3) Next, as shown in FIG. 7, the dice 42 is put into the dice holder 35, and the fixing bolt 44 is lightly screwed into the screw hole 42 b of the dice 42 and held in a temporarily fixed state. Further, the position adjusting bolt 45 is initially loosened so that its tip does not contact the outer peripheral surface of the die 42.
Then, the tool 42 is inserted into the tool recess 42c of the die 42 so that the protrusions 52 and 53 of the position adjusting jig 51 are inserted into the die hole 42a, and the position of the die 42 is adjusted in a direction intersecting the axis. In addition, it is preferable to adjust so that the clearance gap between the die hole 42a and the protrusion parts 52 and 53 may become uniform so that the protrusion parts 52 and 53 may not contact the inner peripheral surface of the die hole 42a.
In this way, as shown in FIG. 8, the protrusions 52 and 53 of the position adjusting jig 51 are inserted into the die hole 42a, so that the die 42 is positioned in the direction around the axis and in the direction intersecting the axis. Is done.

(4) After positioning the die 42 with the position adjusting jig 51 as described above, the fixing bolt 44 is tightened to fasten and fix the die 42 to the die holder 35, and the position adjusting bolt 45 is evenly tightened. Fix it.

(5) Pull out the nipple holder 36 from the die holder 35 to remove the position adjusting jig 51, and then attach the nipple 41 to the nipple holder 36 and attach the nipple holder 36 to the die holder 35 as shown in FIG. Thus, the nipple 41 is fixed at the fixed position of the nipple 41.
In this way, the nipple 41 mounted on the die holder 35 via the nipple holder 36 and the die 42 positioned by the position adjusting jig 51 are aligned with high accuracy.

When the nipple 41 and the die 42 are positioned as described above, the optical fiber core wire 2 and the tensile body 3 are inserted into the optical fiber core wire introduction hole 41a, the strength member introduction hole 41b, and the support wire introduction hole 41c of the nipple 41. Then, the support wire 4 is introduced and pulled out from the die hole 42 a of the die 42.
Thereafter, the optical fiber core wire 2, the tensile body 3 and the support wire 4 are connected while the thermoplastic resin is supplied from the extruder 31 to the resin supply flow path 37 and the gap 43 between the die 42 and the nipple 41 through the resin supply port 38. By pulling out from the die hole 42a, the optical fiber cable 1 in which the optical fiber core wire 2, the strength member 3 and the support wire 4 are coated with the coating resin 5 to have the cross-sectional shape of the die hole 42a is formed.

  As described above, according to the cable manufacturing method according to the above embodiment, the position adjusting jig 51 is positioned at the nipple fixing position with respect to the die holder 35 before the optical fiber cable 1 is extruded by the cross head 32 of the extrusion molding machine 18. The die 42 is fixed to the die holder 35 at a position where the protrusions 52 and 53 of the position adjusting jig 51 are inserted into the die hole 42a of the die 42, and the position adjusting jig 51 is removed from the die holder 35 to nipple. 41 is fixed, so that the optical fiber cable 1 is observed without cross-section of the optical fiber cable 1, the bias of the optical fiber core 2, the strength member 3, and the support wire 4 is adjusted to adjust the position. Manufactured by easily positioning an optical fiber cable 1 in which a plurality of linear members composed of a core wire 2, a tensile body 3 and a support wire 4 are coated with a coating resin 5 Rukoto can.

  In the above-described embodiment, the case where the optical fiber cable 1 is extrusion-molded by coating the optical fiber core wire 2, the tensile body 3 and the support wire 4 with the coating resin 5 has been described as an example. The members are not limited to these optical fiber core wire 2, strength member 3 and support wire 4. Moreover, it is applicable not only to the optical fiber cable 1 provided with the optical fiber core wire 2 but also to a cable for power transmission or the like in which a plurality of conducting wires are coated with resin.

It is sectional drawing of the cable manufactured in this embodiment. It is a schematic block diagram which shows the manufacturing apparatus of the cable manufactured in this embodiment. It is sectional drawing which shows the crosshead to which this embodiment was applied. It is a front view of the crosshead of FIG. It is sectional drawing of a nipple holder. It is the side view and front view explaining a position adjustment jig. It is sectional drawing of a crosshead. It is a front view of a crosshead. It is sectional drawing of a crosshead.

Explanation of symbols

1 Optical fiber cable (cable)
2 Optical fiber core wire (linear member)
3 Strength members (linear members)
4 Support lines (linear members)
5 Coating resin 18 Extruder 32 Crosshead 35 Die holder 41 Nipple 42 Die 42a Die hole 51 Position adjustment jig 52, 53 Projection

Claims (1)

Manufactures a cable in which a plurality of linear members are coated with a resin by a cross head that holds a nipple for guiding a plurality of linear members and a die having a die hole through which resin is extruded together with the linear members from the nipple. A cable manufacturing method comprising:
Using a position adjustment jig provided with a projecting portion having a cross-sectional shape approximate to the shape of the die hole of the die at the tip portion, and other portions except for the tip portion have the same shape as the nipple,
Before extrusion of the cable by the crosshead,
Fixing the position adjusting jig at a nipple fixing position with respect to the die holder;
Fixing the die to the die holder at a position where the protruding portion of the position adjusting jig is inserted into a die hole of the die;
A cable manufacturing method, wherein the position adjusting jig is removed from the die holder and the nipple is fixed at the nipple fixing position with respect to the die holder.

Images