JP4503192B2

JP4503192B2 - Slot for optical fiber cable

Info

Publication number: JP4503192B2
Application number: JP2001030782A
Authority: JP
Inventors: 裕人渡邉; 和永小林; 末広宮本
Original assignee: Fujikura Ltd
Current assignee: Fujikura Ltd
Priority date: 2001-02-07
Filing date: 2001-02-07
Publication date: 2010-07-14
Anticipated expiration: 2021-02-07
Also published as: JP2002228901A

Description

【０００１】
【発明の属する技術分野】
本発明は、光ファイバ収納用の交互に反転する複数の螺旋状溝を有する光ファイバケーブル用スロットに関する。
【０００２】
【従来の技術】
図７は、外周に光ファイバ収納用の交互に反転する螺旋状溝を有する光ファイバケーブル用スロットの代表的なものの断面図を示すものである。このスロットは、抗張力線１と、その外周に設けられた一次被覆層２と、一次被覆層２の外周に設けられた二次被覆層３で構成されている。二次被覆層３の外周には、断面形状が略Ｕ字型の螺旋溝５が複数個形成され、該螺旋溝５はリブ６により隔てられている。該螺旋溝５はスロットの長手方向にわたって形成され、所定間隔毎に反転するように形成されている。
【０００３】
この種のスロットの製造方法としては、スロットの断面形状を有するダイから溶融樹脂を押出して抗張力線に被覆する際に、ダイ自身を交互に回転するか、あるいは抗張力線を交互に回転する方法が公知である。
【０００４】
【発明が解決しようとする課題】
しかし、従来公知のこれらの方法では、スロットの螺旋方向が反転する部分の近傍において、樹脂が冷却固化する際の体積収縮等によって、螺旋溝５を形成するリブ６が反転中心側に傾いて、例えば図８に示すように螺旋溝５が変形する。そのため、光ファイバ心線を確実に螺旋溝内に収納することが困難になるという欠点があった。
【０００５】
【課題を解決するための手段】
上記問題を解決するために本発明は、抗張力線と、この抗張力線の外周部を被覆する一次被覆層と、この一次被覆層の外周に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を形成するように被覆した二次被覆層とを有する光ファイバケーブル用スロットにおいて、前記一次被覆層の外周部を、前記二次被覆層の螺旋状溝間で形成されるリブ部の根元にあたる部分に沿って突起を設けた形状としたことを特徴とする。
【０００６】
また、前記一次被覆層外周部の突起の先端の外接円の径ｄ３と、前記螺旋状溝の底部の内接円の径ｄ２と、前記二次被覆層最外周の径ｄ４との関係が、
ｄ２＜ｄ３＜ｄ４
好ましくは、
ｄ２＋０.１（ｄ４−ｄ２）＜ｄ３＜ｄ４−０.５（ｄ４−ｄ２）
を満足していることを特徴とする。
【０００７】
また、請求項４記載の光ファイバケーブル用スロットの製造装置は、回転制御機構を備えたダイス部を有し、抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成する一次被覆層形成装置と、この一次被覆層形成装置で形成された一次被覆層外周部の突起が長手方向に描く軌跡を検出する検出装置と、この検出装置で検出した一次被覆層外周部の螺旋状突起が長手方向に描く軌跡に追従して回転するダイス部を有し、一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成する二次被覆層形成装置で構成されることを特徴とする。
【０００８】
請求項５記載の光ファイバケーブル用スロットの製造装置は、回転機構を備えたダイス部を有し、抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成する一次被覆層形成装置と、この一次被覆層形成装置の後段に配置され、回転機構を備えたダイス部を有し、前記一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成する二次被覆層形成装置と、これら一次及び二次被覆層形成装置の回転機構を関連して制御する制御装置で構成されることを特徴とする。
【０００９】
請求項６記載の光ファイバケーブル用スロットの製造装置は、回転機構を備えたダイス部を有し、抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成する一次被覆層形成装置と、この一次被覆層形成装置の後段に配置され、固定ダイス部を有し、前記一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成する二次被覆層形成装置と、前記二次被覆層形成装置の前段および後段、もしくは前段のみに、前記二次被覆層形成装置と距離をおいて設置され、前記スロットを把持する把持機構とから構成されることを特徴とする。
請求項６記載の光ファイバケーブル用スロットの製造装置において、前記一次被覆層外周部の突起の先端の外接円の径ｄ３と、前記螺旋状溝の底部の内接円の径ｄ２と、前記二次被覆層最外周の径ｄ４とが、ｄ２＜ｄ３＜ｄ４の関係を満足するように、前記一次被覆層形成装置が前記一次被覆層を形成するとともに、前記二次被覆層形成装置が前記二次被覆層を形成することが好ましい。
【００１０】
請求項８記載の光ファイバケーブル用スロットの製造方法は、回転制御機構を備えたダイス部を用いて抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成し、該一次被覆層の外周部の突起が長手方向に描く軌跡を検出し、この軌跡に追従して回転するダイス部を用いて、該一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成することを特徴とする。
【００１１】
請求項９記載の光ファイバケーブル用スロットの製造方法は、回転機構を備えたダイス部を用いて抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成し、ついで該一次被覆層の外周部に回転機構を備えたダイス部を用いて長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成するとともに、上記ダイス部の回転運動を関連して制御することを特徴とする。
【００１２】
請求項１０記載の光ファイバケーブル用スロットの製造方法は、回転機構を備えたダイス部を用いて抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成し、ついで該一次被覆層の外周部に固定ダイス部を用いて長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成し、前記二次被覆層の形成前後または前記二次被覆層の形成前に、前記固定ダイス部と間隔を置いて配置された把持機構を用いて、前記スロットを把持することを特徴とする。
請求項１０記載の光ファイバケーブル用スロットの製造方法において、前記一次被覆層外周部の突起の先端の外接円の径ｄ３と、前記螺旋状溝の底部の内接円の径ｄ２と、前記二次被覆層最外周の径ｄ４とが、ｄ２＜ｄ３＜ｄ４の関係を満足するように、前記一次被覆層と前記二次被覆層を形成することが好ましい。
【００１３】
【発明の実施の形態】
以下本発明の実施の形態について、図１ないし図６により詳細に説明する。
図１は、本発明の光ファイバケーブル用スロットの断面形状の実施例を示している。このスロットは、中心部に配置された抗張力線１と、その外周に設けられた一次被覆層２と、一次被覆層２の外周に設けられた二次被覆層３で構成されている。
【００１４】
二次被覆層３の外周には、略Ｕ字型の螺旋溝５が複数個形成され、該螺旋溝５はリブ６により隔てられている。該螺旋溝５はスロットの長手方向にわたって設置され、所定間隔毎に反転するように形成されている。
一次被覆層２の外周には、凸型の突起４が、リブ６の根元部にあたる部分に沿って設けられている。この突起４は、リブ６と同じ周期で所定間隔毎に反転する螺旋状に形成されている。
【００１５】
そのため、リブ６の根元部の近傍で二次被覆層３と一次被覆層２との接触面積が広くなり、二次被覆層３から一次被覆層２への伝熱による放熱が進みやすく、リブ根元部の冷却固化が早期に進行する。リブ６を支持するためのリブ根元部が冷却固化された後にリブ中央部が冷却固化するので、リブ中央部の根元側の樹脂が冷却固化する際に収縮してリブ根元部の未固化樹脂を引き込む作用がなくなり、リブ６の変形を抑えることができる。
【００１６】
一次被覆層２の突起４は、小さくし過ぎると二次被覆層３と一次被覆層２の接触面積が広くできないので、二次被覆層３から一次被覆層２への放熱効果が不十分となる。また、大きくし過ぎると二次被覆層３を形成する際にダイスに突起４が引っ掛かりやすくなる。
【００１７】
そのため、一次被覆層２の外周部の突起４の先端の外接円の径ｄ３と、螺旋状溝５の底部の内接円の径ｄ２と、二次被覆層３の最外周の径ｄ４とは、
ｄ２＜ｄ３＜ｄ４
の関係を満足している必要があり、さらには、
ｄ２＋０.１（ｄ４−ｄ２）＜ｄ３＜ｄ４−０.５（ｄ４−ｄ２）
の関係を満足していることが好ましい。
【００１８】
ここで、ｄ２＜ｄ３＜ｄ４は、一次被覆層２の外周部の突起４の先端が、螺旋状溝５の底部の内接円と二次被覆層３の最外周との間に位置する必要があることを示している。
さらに、ｄ２＋０.１（ｄ４−ｄ２）＜ｄ３＜ｄ４−０.５（ｄ４−ｄ２）は、図１より、ｄ２＋０.１×２ｈ＜ｄ３＜ｄ４−０.５×２ｈと表され、一次被覆層２の外周部の突起４の先端は、螺旋状溝５の底部の内接円よりも半径方向外側にリブ６の高さｈの１０％を超えたところに位置することが好ましく、二次被覆層３の最外周よりも半径方向内側にリブ６の高さの５０％を超えたところに位置することが好ましいことを示している。
【００１９】
なお、一次被覆層２の外周凹部の底部の内接円の径ｄ1は、あまり小さくし過ぎると二次被覆層３の押出し時に一次被覆層２の突起４が倒れやすくなるので、次の範囲であることが望ましい。
０.８５ｄ２＜ｄ１＜ｄ２
【００２０】
図４は、本発明の製造装置の第１の実施例を示している。
送出し装置１１から送出された抗張力線１は、一次被覆層形成装置１２へ送られる。該一次被覆層形成装置１２は、押出し装置１３と冷却装置１４で構成されている。
押出し装置１３内には、回転制御機構を備えた回転するダイス部が備えられており、抗張力線１の通過する所定間隔毎にダイス部の回転方向が反転する。このダイス部の断面形状は、得ようとする一次被覆層外形に対応した図２に示す形状となっている。そして、抗張力線１の外周部にダイス形状に対応した形で樹脂が押出され、長手方向にわたり所定間隔毎に反転する複数の螺旋状突起４を有する一次被覆層２が形成される。
【００２１】
抗張力線１上の一次被覆層２が冷却装置１４で冷却固化された後、検出装置１５で一次被覆層外周の突起４が長手方向に描く軌跡が読み取られ、二次被覆層形成装置１６に連続的に送られる。
【００２２】
二次被覆層形成装置１６は、押出し装置１７と冷却装置１８で構成されている。押出し装置１７内には、前記検出装置１５で検出された一次被覆層外周部の突起４が長手方向に描く軌跡に追従して回転するダイス部が備えられている。このダイス部の断面形状は、得ようとするスロット外形に対応した図３に示す形状となっている。そして、一次被覆層２の外周部にダイス形状に対応した形で樹脂が押出され、長手方向にわたり所定間隔毎に反転する複数の螺旋状溝５を有する二次被覆層３が形成される。
【００２３】
一次被覆層形成装置１２内で、抗張力線１は、回転するダイス部により押出された樹脂との摩擦で捩りを与えられる。但し、回転ダイス部を通過すると摩擦が無くなり、抗張力線１に与えられた捩れは戻る。
ここで、ダイスの設定回転角度をスロット完成時の所定回転角度に設定しておいた場合、抗張力線１が前記のように捩られてから戻るので、抗張力線１が捩られた回転角度分だけスロット完成時の所定回転角度が不足することになる。
そのため、ダイスの設定回転角度は、この捩れ分を見込んでスロット完成時の所定回転角度よりも大きめに設定しておく。
【００２４】
この捩りが二次被覆層形成時に影響を与えないようにするためには、一次被覆層形成装置１２の前段及び後段、もしくは後段のみにスロットの把持機構（図示しない）を設けておく。該把持機構は、例えば２枚の対向したベルトでスロットを上下から押さえ込み、スロットの回転を防止できる構造のものを用いると良い。
【００２５】
図５は、本発明の製造装置の第２の実施例を示している。
送出し装置２１から送出された抗張力線１は、一次被覆層形成装置２２へ送られる。該一次被覆層形成装置２２は、押出し装置２３と冷却装置２４で構成されている。
押出し装置２３内には、回転機構を備えた回転するダイス部が設けられ、抗張力線１の通過する所定間隔毎にダイス部の回転方向が反転する。このダイス部の断面形状は、得ようとする一次被覆層外形に対応した図２に示す形状となっている。
そして、抗張力線１の外周部にダイス形状に対応した形で樹脂が押出され、長手方向にわたり所定間隔毎に反転する複数の螺旋状突起４を有する一次被覆層２が形成される。
【００２６】
抗張力線上の一次被覆層は冷却装置２４で冷却固化された後、二次被覆層形成装置２６に入る。
二次被覆層形成装置２６は、押出し装置２７と冷却装置２８で構成されている。押出し装置２７内には、回転機構を備えたダイス部が設けられ、このダイス部の断面形状は、得ようとするスロット外形に対応した図３に示す形状となっている。そして、一次被覆層２の外周部にダイス形状に対応した形で樹脂が押出され、長手方向にわたり所定間隔毎に反転する複数の螺旋状溝５を有する二次被覆層３が形成される。
【００２７】
これら一次及び二次被覆層形成装置２２、２６の回転機構は、一次被覆層外周部の突起４が長手方向に描く軌跡と二次被覆層外周部のリブ６が長手方向に描く軌跡を同位置にするために、例えば次の如く制御装置２５により関連して制御される。
二次被覆層形成装置２６の回転機構の回転速度及び回転方向を、一次被覆層形成装置２２の回転機構と同期させる。かつ、二次被覆層形成装置２６の回転ダイス部と一次被覆層形成装置２２の回転ダイス部間の距離と回転ダイスの回転方向の初期位置を、一次被覆層外周部の突起４が長手方向に描く軌跡と二次被覆層外周部のリブ６が長手方向に描く軌跡が重なるように設定する。
【００２８】
図６は、本発明の製造装置の第３の実施例を示している。
送出し装置３１から送出された抗張力線１は、一次被覆層形成装置３２へ送られる。該一次被覆層形成装置３２は、押出し装置３３と冷却装置３４で構成されている。
押出し装置３３内には、回転機構を備えた回転するダイス部が設けられ、抗張力線１の通過する所定間隔毎にダイス部の回転方向が反転する。このダイス部の断面形状は、得ようとする一次被覆層外形に対応した図２に示す形状となっている。
そして、抗張力線１の外周部にダイス形状に対応した形で樹脂が押出され、長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層が形成される。
【００２９】
抗張力線上の一次被覆層は冷却装置３４で冷却固化された後、二次被覆層形成装置３６に入る。
二次被覆層形成装置３６は、押出し装置３７と冷却装置３８で構成されている。押出し装置３７内には、固定ダイスが設けられ、このダイス部の断面形状は、得ようとするスロット外形に対応した図３に示す形状となっている。
一次被覆層外周部の突起４は、固定ダイスのリブ部に嵌合するように固定ダイスに進入して行く。この時、一次被覆層外周部の突起４の外径ｄ３は、二次被覆層最外周の外径ｄ４と螺旋状溝５の底部の内接円ｄ２の間に位置するので、一次被覆層外周部の突起４が交互に反転しても固定ダイスのリブ部からは外れない。そのため、スロットが固定ダイス部を通過する際には、スロット全体が一次被覆層外周部の突起４の軌跡に沿って交互に反転しながら進む。
このようにして、一次被覆層２の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝５を有する二次被覆層３が形成される。
【００３０】
スロットが反転する際の捩りが一次被覆層形成時に影響を与えないようにするためには、二次被覆層形成装置３６の前段及び後段、もしくは前段のみにスロットの把持機構（図示しない）を設けておく。但し、該把持機構を二次被覆層形成装置３６に近接させて設置すると、スロットが固定ダイス部を捩れながら通過することが困難になるので、該把持機構は二次被覆層形成装置と距離をおいて設置することが好ましい。該把持機構は、例えば２枚の対向したベルトでスロットを上下から押さえ込み、スロットの回転を防止できる構造のものを用いると良い。
【００３１】
【発明の効果】
以上説明したように、本発明の光ファイバケーブル用スロットは、抗張力線と、この抗張力線の外周部を被覆する一次被覆層と、この一次被覆層の外周に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を形成するように被覆した二次被覆層とを有し、一次被覆層の外周部を、二次被覆層の螺旋状溝間で形成されるリブ部の根元にあたる部分に沿って突起を設けた形状としているので、リブの根元部の近傍で二次被覆層と一次被覆層との接触面積が広くなり、二次被覆層から一次被覆層への伝熱による放熱が進みやすく、リブ根元部の冷却固化が早期に進行する。リブを支持するためのリブ根元部が冷却固化された後にリブ中央部が冷却固化するので、リブ中央部の根元側の樹脂が冷却固化する際にリブ根元部の未固化樹脂を引き込む作用がなくなり、リブの変形を抑えることができる。
【００３２】
また、一次被覆層の外周部の突起の先端の外接円の径ｄ３と、螺旋状溝の底部の内接円の径ｄ２と、二次被覆層の最外周の径ｄ４とが、
ｄ２＋０.１（ｄ４−ｄ２）＜ｄ３＜ｄ４−０.５（ｄ４−ｄ２）
の関係を満足していることにより、二次被覆層と一次被覆層の接触面積を広く保つことができるので、二次被覆層から一次被覆層への十分な放熱効果を得ることができ、また、二次被覆層を形成する際にダイスに突起が引っ掛かりやすくなることを防ぐことができる。
【００３３】
回転制御機構を備えたダイス部を有し、抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成する一次被覆層形成装置と、この一次被覆層形成装置で形成された一次被覆層外周部の突起が長手方向に描く軌跡を検出する検出装置と、この検出装置で検出した一次被覆層外周部の螺旋状突起が長手方向に描く軌跡に追従して回転するダイス部を有し、一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成する二次被覆層形成装置で構成されることを特徴とする請求項４記載の光ファイバケーブル用スロットの製造装置を用いることにより、抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成し、該一次被覆層の外周部の突起が長手方向に描く軌跡を検出し、この軌跡に追従して、該一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成することができる。
【００３４】
回転機構を備えたダイス部を有し、抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成する一次被覆層形成装置と、この一次被覆層形成装置の後段に配置され、回転機構を備えたダイス部を有し、前記一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成する二次被覆層形成装置と、これら一次及び二次被覆層形成装置の回転機構を関連して制御する制御装置で構成されることを特徴とする請求項５記載の光ファイバケーブル用スロットの製造装置を用いることにより、抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成し、ついで該一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成ことができる。
【００３５】
回転機構を備えたダイス部を有し、抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成する一次被覆層形成装置と、この一次被覆層形成装置の後段に配置され、固定ダイス部を有し、前記一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成する二次被覆層形成装置で構成されることを特徴とする請求項６記載の光ファイバケーブル用スロットの製造装置を用いることにより、抗張力線の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状突起を有する一次被覆層を形成し、ついで該一次被覆層の外周部に長手方向にわたり所定間隔毎に反転する複数の螺旋状溝を有する二次被覆層を形成することができる。
【図面の簡単な説明】
【図１】本発明の光ファイバケーブル用スロットの断面図である。
【図２】本発明の光ファイバケーブル用スロットの製造装置の一次被覆層形成装置のダイス部出口の断面図である。
【図３】本発明の光ファイバケーブル用スロットの製造装置の二次被覆層形成装置のダイス部出口の断面図である。
【図４】本発明の光ファイバケーブル用スロットの製造装置の第１の実施例の構成図である。
【図５】本発明の光ファイバケーブル用スロットの製造装置の第２の実施例の構成図である。
【図６】本発明の光ファイバケーブル用スロットの製造装置の第３の実施例の構成図である。
【図７】従来の光ファイバケーブル用スロットの断面図の一例である。
【図８】従来の光ファイバケーブル用スロットの螺旋溝が反転する部分の断面図の一例である。
【符号の説明】
１…抗張力体、２…一次被覆層、３…二次被覆層、４…突起、５…螺旋溝、６…リブ、１１,２１,３１…送出し装置、１２,２２,３２…一次被覆層形成装置、１３,２３,３３,１７,２７…回転ダイス部付押出し装置、１４,２４,３４,１８,２８,３８…冷却装置、１５…検出装置、１６,２６,３６…二次被覆層形成装置、２５…回転制御装置、３７…固定ダイス部付押出し装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical fiber cable slot having a plurality of alternately inverted spiral grooves for storing optical fibers.
[0002]
[Prior art]
FIG. 7 shows a cross-sectional view of a typical slot for an optical fiber cable having spiral grooves alternately inverted for accommodating optical fibers on the outer periphery. This slot is composed of a tensile wire 1, a primary coating layer 2 provided on the outer periphery thereof, and a secondary coating layer 3 provided on the outer periphery of the primary coating layer 2. A plurality of spiral grooves 5 having a substantially U-shaped cross section are formed on the outer periphery of the secondary coating layer 3, and the spiral grooves 5 are separated by ribs 6. The spiral groove 5 is formed along the longitudinal direction of the slot and is formed so as to be reversed at predetermined intervals.
[0003]
As a manufacturing method of this type of slot, when the molten resin is extruded from a die having a cross-sectional shape of the slot and coated on the tensile strength wire, the die itself is rotated alternately or the tensile strength wire is rotated alternately. It is known.
[0004]
[Problems to be solved by the invention]
However, in these conventionally known methods, in the vicinity of the portion where the spiral direction of the slot is reversed, the rib 6 forming the spiral groove 5 is inclined toward the inversion center side due to volume shrinkage or the like when the resin is cooled and solidified. For example, the spiral groove 5 is deformed as shown in FIG. Therefore, there has been a drawback that it is difficult to reliably store the optical fiber core wire in the spiral groove.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a tensile wire, a primary coating layer that covers the outer periphery of the tensile wire, and a plurality of spiral grooves that are inverted at predetermined intervals over the outer periphery of the primary coating layer in the longitudinal direction. A slot for an optical fiber cable having a secondary coating layer coated so as to form an outer peripheral portion of the primary coating layer, the portion corresponding to the root of a rib portion formed between the spiral grooves of the secondary coating layer It is characterized by having a shape provided with a protrusion along the line.
[0006]
Further, the relationship between the diameter d3 of the circumscribed circle at the tip of the protrusion on the outer periphery of the primary coating layer, the diameter d2 of the inscribed circle at the bottom of the spiral groove, and the diameter d4 of the outermost periphery of the secondary coating layer,
d2 <d3 <d4
Preferably,
d2 + 0.1 (d4-d2) <d3 <d4-0.5 (d4-d2)
It is characterized by satisfying.
[0007]
According to a fourth aspect of the present invention, there is provided a manufacturing apparatus for a slot for an optical fiber cable, comprising: a die portion having a rotation control mechanism; and a plurality of spiral protrusions that are inverted at predetermined intervals along the longitudinal direction on an outer peripheral portion of the tensile strength line. A primary coating layer forming device for forming a primary coating layer, a detection device for detecting a trajectory drawn in the longitudinal direction by protrusions on the outer periphery of the primary coating layer formed by the primary coating layer forming device, and a detection device for detecting A spiral protrusion on the outer periphery of the primary coating layer has a die portion that rotates following the trajectory drawn in the longitudinal direction, and has a plurality of spiral grooves that are inverted at predetermined intervals along the longitudinal direction on the outer periphery of the primary coating layer. It is comprised with the secondary coating layer forming apparatus which forms a secondary coating layer, It is characterized by the above-mentioned.
[0008]
The apparatus for manufacturing a slot for an optical fiber cable according to claim 5 includes a primary coating having a die portion having a rotation mechanism and a plurality of spiral protrusions that are inverted at predetermined intervals along the longitudinal direction on the outer peripheral portion of the tensile strength wire. A primary coating layer forming apparatus for forming a layer, and a die part provided with a rotating mechanism, arranged at a subsequent stage of the primary coating layer forming apparatus, and reversed at predetermined intervals over the longitudinal direction on the outer periphery of the primary coating layer A secondary coating layer forming device for forming a secondary coating layer having a plurality of spiral grooves and a control device for controlling the rotation mechanisms of the primary and secondary coating layer forming devices in association with each other. And
[0009]
The apparatus for manufacturing a slot for an optical fiber cable according to claim 6, wherein the primary coating has a die portion having a rotation mechanism, and has a plurality of spiral protrusions that are inverted at predetermined intervals along the longitudinal direction on the outer peripheral portion of the tensile strength wire. A primary coating layer forming apparatus for forming a layer, and a plurality of spirals disposed at a subsequent stage of the primary coating layer forming apparatus, having a fixed die portion, and being inverted at predetermined intervals along the longitudinal direction on the outer peripheral portion of the primary coating layer A secondary coating layer forming apparatus for forming a secondary coating layer having a groove, and the secondary coating layer forming apparatus is disposed at a distance from the secondary coating layer forming apparatus at a front stage and a rear stage of the secondary coating layer forming apparatus, or only at a front stage. And a gripping mechanism for gripping the slot .
7. The apparatus for manufacturing a slot for an optical fiber cable according to claim 6, wherein a diameter d3 of a circumscribed circle at a tip of the protrusion on the outer periphery of the primary coating layer, a diameter d2 of an inscribed circle at the bottom of the spiral groove, The primary coating layer forming apparatus forms the primary coating layer so that the diameter d4 of the outermost circumference of the secondary coating layer satisfies the relationship d2 <d3 <d4, and the secondary coating layer forming apparatus It is preferable to form a secondary coating layer.
[0010]
9. A method of manufacturing a slot for an optical fiber cable according to claim 8 , wherein a primary coating having a plurality of spiral protrusions that are inverted at predetermined intervals along the longitudinal direction on the outer peripheral portion of the tensile strength wire using a die portion having a rotation control mechanism. Forming a layer, detecting a trajectory drawn by the protrusions on the outer peripheral portion of the primary coating layer in the longitudinal direction, and using a dice portion that rotates following the trajectory, the outer peripheral portion of the primary coating layer is predetermined in the longitudinal direction. A secondary coating layer having a plurality of spiral grooves that are inverted at intervals is formed.
[0011]
10. The method of manufacturing a slot for an optical fiber cable according to claim 9 , wherein a primary coating layer having a plurality of spiral protrusions that are inverted at predetermined intervals over the longitudinal direction on the outer peripheral portion of the tensile strength wire using a die portion having a rotation mechanism. And then forming a secondary coating layer having a plurality of spiral grooves that are inverted at predetermined intervals in the longitudinal direction using a die portion having a rotation mechanism on the outer peripheral portion of the primary coating layer. It is characterized in that the rotational movement of the part is controlled in relation to it.
[0012]
The method for manufacturing a slot for an optical fiber cable according to claim 10 , wherein a primary coating layer having a plurality of spiral protrusions that are inverted at predetermined intervals over the longitudinal direction on the outer peripheral portion of the tensile strength wire using a die portion having a rotation mechanism. And then forming a secondary coating layer having a plurality of spiral grooves that are inverted at predetermined intervals in the longitudinal direction using a fixed die portion on the outer periphery of the primary coating layer, and forming the secondary coating layer Before and after the formation of the secondary coating layer, the slot is gripped by using a gripping mechanism disposed at a distance from the fixed die portion .
11. The method for manufacturing a slot for an optical fiber cable according to claim 10, wherein a diameter d3 of a circumscribed circle at a tip of the protrusion on the outer peripheral portion of the primary coating layer, a diameter d2 of an inscribed circle at the bottom of the spiral groove, It is preferable to form the primary coating layer and the secondary coating layer so that the diameter d4 of the outermost circumference of the secondary coating layer satisfies the relationship of d2 <d3 <d4.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.
FIG. 1 shows an embodiment of a cross-sectional shape of a slot for an optical fiber cable according to the present invention. This slot is composed of a tensile strength wire 1 disposed in the center, a primary coating layer 2 provided on the outer periphery thereof, and a secondary coating layer 3 provided on the outer periphery of the primary coating layer 2.
[0014]
A plurality of substantially U-shaped spiral grooves 5 are formed on the outer periphery of the secondary coating layer 3, and the spiral grooves 5 are separated by ribs 6. The spiral groove 5 is installed over the longitudinal direction of the slot and is formed so as to be reversed at predetermined intervals.
On the outer periphery of the primary coating layer 2, convex protrusions 4 are provided along portions corresponding to the root portions of the ribs 6. The protrusions 4 are formed in a spiral shape that reverses at predetermined intervals with the same period as the ribs 6.
[0015]
Therefore, the contact area between the secondary coating layer 3 and the primary coating layer 2 increases in the vicinity of the root portion of the rib 6, and heat dissipation from the secondary coating layer 3 to the primary coating layer 2 easily proceeds. Cooling and solidification of the part proceeds at an early stage. Since the rib central portion for cooling and solidifying the rib base portion for supporting the rib 6 is cooled and solidified, the resin on the root side of the rib central portion contracts when the solidified by cooling, and the unsolidified resin at the rib root portion is removed. The drawing action is eliminated, and the deformation of the rib 6 can be suppressed.
[0016]
If the protrusion 4 of the primary coating layer 2 is too small, the contact area between the secondary coating layer 3 and the primary coating layer 2 cannot be increased, so that the heat dissipation effect from the secondary coating layer 3 to the primary coating layer 2 becomes insufficient. . On the other hand, if the size is too large, the protrusion 4 is easily caught on the die when the secondary coating layer 3 is formed.
[0017]
Therefore, the diameter d3 of the circumscribed circle at the tip of the projection 4 on the outer peripheral portion of the primary coating layer 2, the diameter d2 of the inscribed circle at the bottom of the spiral groove 5, and the outermost diameter d4 of the secondary coating layer 3 are: ,
d2 <d3 <d4
Must be satisfied, and
d2 + 0.1 (d4-d2) <d3 <d4-0.5 (d4-d2)
It is preferable that the relationship is satisfied.
[0018]
Here, d2 <d3 <d4 needs to be such that the tip of the protrusion 4 on the outer periphery of the primary coating layer 2 is located between the inscribed circle at the bottom of the spiral groove 5 and the outermost periphery of the secondary coating layer 3. It shows that there is.
Further, d2 + 0.1 (d4-d2) <d3 <d4-0.5 (d4-d2) is expressed as d2 + 0.1 × 2h <d3 <d4-0.5 × 2h from FIG. The tip of the protrusion 4 on the outer peripheral portion of the layer 2 is preferably located at a position exceeding 10% of the height h of the rib 6 on the outer side in the radial direction from the inscribed circle at the bottom of the spiral groove 5. This indicates that it is preferable to be located at a position exceeding 50% of the height of the rib 6 on the radially inner side of the outermost periphery of the coating layer 3.
[0019]
If the diameter d1 of the inscribed circle at the bottom of the outer peripheral recess of the primary coating layer 2 is too small, the protrusion 4 of the primary coating layer 2 is likely to fall down when the secondary coating layer 3 is extruded. It is desirable to be.
0.85d2 <d1 <d2
[0020]
FIG. 4 shows a first embodiment of the manufacturing apparatus of the present invention.
The tensile strength wire 1 delivered from the delivery device 11 is sent to the primary coating layer forming device 12. The primary coating layer forming device 12 includes an extrusion device 13 and a cooling device 14.
The extrusion device 13 is provided with a rotating die portion having a rotation control mechanism, and the direction of rotation of the die portion is reversed at every predetermined interval through which the tensile strength line 1 passes. The cross-sectional shape of the die portion is a shape shown in FIG. 2 corresponding to the outer shape of the primary coating layer to be obtained. Then, the resin is extruded in a shape corresponding to the die shape on the outer peripheral portion of the tensile strength wire 1 to form the primary coating layer 2 having a plurality of spiral protrusions 4 that are inverted at predetermined intervals in the longitudinal direction.
[0021]
After the primary coating layer 2 on the tensile strength line 1 is cooled and solidified by the cooling device 14, the locus drawn by the protrusion 4 on the outer periphery of the primary coating layer in the longitudinal direction is read by the detection device 15, and is continuously connected to the secondary coating layer forming device 16. Sent.
[0022]
The secondary coating layer forming device 16 includes an extrusion device 17 and a cooling device 18. The extrusion device 17 includes a die portion that rotates following the trajectory drawn in the longitudinal direction by the protrusion 4 on the outer periphery of the primary coating layer detected by the detection device 15. The cross-sectional shape of this die portion is the shape shown in FIG. 3 corresponding to the outer shape of the slot to be obtained. And resin is extruded to the outer peripheral part of the primary coating layer 2 in the shape corresponding to a die shape, and the secondary coating layer 3 which has the some helical groove | channel 5 which reverses for every predetermined space | interval over a longitudinal direction is formed.
[0023]
In the primary coating layer forming apparatus 12, the tensile strength wire 1 is twisted by friction with the resin extruded by the rotating die part. However, when passing through the rotating die portion, the friction disappears and the twist applied to the tensile strength wire 1 returns.
Here, when the set rotation angle of the die is set to a predetermined rotation angle at the time of completion of the slot, the tensile strength wire 1 returns after being twisted as described above, and therefore, only the rotation angle corresponding to the tensile strength wire 1 is twisted. The predetermined rotation angle when the slot is completed is insufficient.
For this reason, the set rotation angle of the die is set to be larger than a predetermined rotation angle at the time of completion of the slot in consideration of the twist.
[0024]
In order to prevent this twist from affecting the formation of the secondary coating layer, a slot gripping mechanism (not shown) is provided only at the front stage, the rear stage, or the rear stage of the primary coating layer forming apparatus 12. As the gripping mechanism, for example, a mechanism that can hold the slot from above and below with two opposing belts and prevent the slot from rotating may be used.
[0025]
FIG. 5 shows a second embodiment of the manufacturing apparatus of the present invention.
The tensile strength wire 1 delivered from the delivery device 21 is sent to the primary coating layer forming device 22. The primary coating layer forming device 22 includes an extrusion device 23 and a cooling device 24.
A rotating die portion having a rotation mechanism is provided in the extrusion device 23, and the rotation direction of the die portion is reversed at every predetermined interval through which the tensile strength wire 1 passes. The cross-sectional shape of the die portion is a shape shown in FIG. 2 corresponding to the outer shape of the primary coating layer to be obtained.
Then, the resin is extruded in a shape corresponding to the die shape on the outer peripheral portion of the tensile strength wire 1 to form the primary coating layer 2 having a plurality of spiral protrusions 4 that are inverted at predetermined intervals in the longitudinal direction.
[0026]
The primary coating layer on the tensile strength line is cooled and solidified by the cooling device 24 and then enters the secondary coating layer forming device 26.
The secondary coating layer forming device 26 includes an extrusion device 27 and a cooling device 28. In the extrusion device 27, a die portion having a rotation mechanism is provided, and the cross-sectional shape of the die portion is a shape shown in FIG. 3 corresponding to the slot outer shape to be obtained. And resin is extruded to the outer peripheral part of the primary coating layer 2 in the shape corresponding to a die shape, and the secondary coating layer 3 which has the some helical groove | channel 5 which reverses for every predetermined space | interval over a longitudinal direction is formed.
[0027]
The rotation mechanisms of the primary and secondary coating layer forming apparatuses 22 and 26 are located at the same position of the trajectory drawn by the protrusion 4 on the outer periphery of the primary coating layer in the longitudinal direction and the trajectory drawn by the rib 6 on the outer periphery of the secondary coating layer in the longitudinal direction. In order to achieve this, for example, control is performed in association with the control device 25 as follows.
The rotational speed and direction of the rotation mechanism of the secondary coating layer forming apparatus 26 are synchronized with the rotation mechanism of the primary coating layer forming apparatus 22. In addition, the distance between the rotating die portion of the secondary coating layer forming device 26 and the rotating die portion of the primary coating layer forming device 22 and the initial position in the rotating direction of the rotating die are indicated by the protrusion 4 on the outer periphery of the primary coating layer in the longitudinal direction. The trajectory drawn and the trajectory drawn in the longitudinal direction by the rib 6 on the outer periphery of the secondary coating layer are set to overlap.
[0028]
FIG. 6 shows a third embodiment of the manufacturing apparatus of the present invention.
The tensile strength wire 1 delivered from the delivery device 31 is sent to the primary coating layer forming device 32. The primary coating layer forming device 32 includes an extrusion device 33 and a cooling device 34.
A rotating die portion having a rotation mechanism is provided in the extrusion device 33, and the rotation direction of the die portion is reversed at every predetermined interval through which the tensile strength wire 1 passes. The cross-sectional shape of the die portion is a shape shown in FIG. 2 corresponding to the outer shape of the primary coating layer to be obtained.
Then, resin is extruded in a shape corresponding to a die shape on the outer peripheral portion of the tensile strength wire 1 to form a primary coating layer having a plurality of spiral protrusions that are inverted at predetermined intervals in the longitudinal direction.
[0029]
The primary coating layer on the tensile strength line is cooled and solidified by the cooling device 34 and then enters the secondary coating layer forming device 36.
The secondary coating layer forming device 36 includes an extrusion device 37 and a cooling device 38. A fixed die is provided in the extrusion device 37, and the cross-sectional shape of this die portion is the shape shown in FIG. 3 corresponding to the outer shape of the slot to be obtained.
The protrusion 4 on the outer periphery of the primary coating layer enters the fixed die so as to be fitted into the rib portion of the fixed die. At this time, since the outer diameter d3 of the protrusion 4 on the outer periphery of the primary coating layer is located between the outer diameter d4 of the outermost periphery of the secondary coating layer and the inscribed circle d2 at the bottom of the spiral groove 5, the outer periphery of the primary coating layer Even if the protrusions 4 of the portions are alternately reversed, they do not come off the rib portion of the fixed die. Therefore, when the slot passes through the fixed die portion, the whole slot advances while being alternately reversed along the locus of the protrusion 4 on the outer peripheral portion of the primary coating layer.
In this manner, the secondary coating layer 3 having a plurality of spiral grooves 5 that are inverted at predetermined intervals along the longitudinal direction is formed on the outer peripheral portion of the primary coating layer 2.
[0030]
In order to prevent the twist when the slot is reversed from affecting the formation of the primary coating layer, a slot gripping mechanism (not shown) is provided at the front and rear stages of the secondary coating layer forming apparatus 36 or only at the front stage. Keep it. However, if the gripping mechanism is installed close to the secondary coating layer forming device 36, it becomes difficult for the slot to pass through the fixed die part while twisting, so the gripping mechanism is separated from the secondary coating layer forming device. It is preferable to install the As the gripping mechanism, for example, a mechanism that can hold the slot from above and below with two opposing belts and prevent the slot from rotating may be used.
[0031]
【The invention's effect】
As described above, the slot for an optical fiber cable of the present invention is inverted at predetermined intervals over the longitudinal direction on the outer periphery of the primary coating layer, the primary coating layer covering the outer periphery of the tensile wire, A secondary coating layer coated so as to form a plurality of spiral grooves, and the outer periphery of the primary coating layer extends along the portion corresponding to the root of the rib portion formed between the spiral grooves of the secondary coating layer. Therefore, the contact area between the secondary coating layer and the primary coating layer is increased in the vicinity of the base of the rib, and heat dissipation from the secondary coating layer to the primary coating layer is easy to proceed. In addition, the cooling and solidification of the rib base portion proceeds at an early stage. Since the rib central part is cooled and solidified after the rib base part for supporting the rib is cooled and solidified, there is no effect of drawing the unsolidified resin at the rib base part when the resin on the root side of the rib central part is cooled and solidified. The deformation of the rib can be suppressed.
[0032]
The diameter d3 of the circumscribed circle at the tip of the protrusion on the outer peripheral portion of the primary coating layer, the diameter d2 of the inscribed circle at the bottom of the spiral groove, and the outermost diameter d4 of the secondary coating layer are:
d2 + 0.1 (d4-d2) <d3 <d4-0.5 (d4-d2)
By satisfying the relationship, the contact area between the secondary coating layer and the primary coating layer can be kept wide, so that a sufficient heat dissipation effect from the secondary coating layer to the primary coating layer can be obtained, and It is possible to prevent protrusions from being easily caught on the die when forming the secondary coating layer.
[0033]
A primary coating layer forming apparatus that has a die portion having a rotation control mechanism and forms a primary coating layer having a plurality of spiral protrusions that are inverted at predetermined intervals over the longitudinal direction on the outer peripheral portion of the tensile strength wire, and the primary coating A detection device that detects the trajectory drawn in the longitudinal direction by the protrusion on the outer periphery of the primary coating layer formed by the layer forming device, and follows the trajectory drawn in the longitudinal direction by the spiral projection on the outer periphery of the primary coating layer detected by this detection device. And a secondary coating layer forming apparatus for forming a secondary coating layer having a plurality of spiral grooves that are rotated at predetermined intervals along the longitudinal direction on the outer peripheral portion of the primary coating layer. By using the optical fiber cable slot manufacturing apparatus according to claim 4, a primary coating layer having a plurality of spiral protrusions that are inverted at predetermined intervals in the longitudinal direction on the outer periphery of the tensile strength wire is formed. A plurality of spiral grooves that detect a trajectory drawn in the longitudinal direction by the protrusions on the outer peripheral portion of the primary coating layer, and follow the trajectory and invert the outer peripheral portion of the primary coating layer in the longitudinal direction at predetermined intervals. A secondary coating layer having can be formed.
[0034]
A primary coating layer forming apparatus for forming a primary coating layer having a plurality of spiral protrusions having a die portion having a rotation mechanism and being reversed at predetermined intervals over the longitudinal direction on the outer peripheral portion of the tensile strength line, and the primary coating layer A secondary coating layer having a plurality of spiral grooves arranged at a predetermined interval in the longitudinal direction is formed on the outer peripheral portion of the primary coating layer, which is disposed at the rear stage of the forming apparatus and has a die portion having a rotation mechanism. 6. An apparatus for manufacturing a slot for an optical fiber cable according to claim 5, comprising a secondary coating layer forming device and a control device for controlling the rotation mechanisms of the primary and secondary coating layer forming devices in association with each other. Is used to form a primary coating layer having a plurality of spiral protrusions that are inverted at predetermined intervals over the longitudinal direction on the outer peripheral portion of the tensile strength wire, and then to the outer peripheral portion of the primary coating layer at a predetermined interval over the longitudinal direction. A plurality of helical grooves reversing can form a secondary coating layer having a.
[0035]
A primary coating layer forming apparatus for forming a primary coating layer having a plurality of spiral protrusions having a die portion having a rotation mechanism and being reversed at predetermined intervals over the longitudinal direction on the outer peripheral portion of the tensile strength line, and the primary coating layer A secondary coating layer that is disposed at a subsequent stage of the forming apparatus, has a fixed die portion, and forms a secondary coating layer having a plurality of spiral grooves that are inverted at predetermined intervals along the longitudinal direction on the outer peripheral portion of the primary coating layer. 7. A device for manufacturing a slot for an optical fiber cable according to claim 6, wherein a plurality of spiral protrusions that are inverted at predetermined intervals over the longitudinal direction are provided on the outer periphery of the tensile strength wire. The primary coating layer can be formed, and then the secondary coating layer having a plurality of spiral grooves that are inverted at predetermined intervals along the longitudinal direction can be formed on the outer periphery of the primary coating layer.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a slot for an optical fiber cable according to the present invention.
FIG. 2 is a cross-sectional view of the outlet of the die portion of the primary coating layer forming apparatus of the optical fiber cable slot manufacturing apparatus of the present invention.
FIG. 3 is a cross-sectional view of the outlet of the die portion of the secondary coating layer forming apparatus of the apparatus for manufacturing a slot for an optical fiber cable according to the present invention.
FIG. 4 is a configuration diagram of a first embodiment of an apparatus for manufacturing a slot for an optical fiber cable according to the present invention.
FIG. 5 is a configuration diagram of a second embodiment of the optical fiber cable slot manufacturing apparatus according to the present invention.
FIG. 6 is a configuration diagram of a third embodiment of the optical fiber cable slot manufacturing apparatus according to the present invention.
FIG. 7 is an example of a cross-sectional view of a conventional slot for an optical fiber cable.
FIG. 8 is an example of a cross-sectional view of a portion where a spiral groove of a conventional optical fiber cable slot is reversed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Strength body, 2 ... Primary coating layer, 3 ... Secondary coating layer, 4 ... Protrusion, 5 ... Spiral groove, 6 ... Rib, 11, 21, 31 ... Delivery apparatus, 12, 22, 32 ... Primary coating layer Forming device, 13, 23, 33, 17, 27 ... Extruding device with rotating die part, 14, 24, 34, 18, 28, 38 ... Cooling device, 15 ... Detection device, 16, 26, 36 ... Secondary coating layer Forming device, 25 ... rotation control device, 37 ... extrusion device with fixed die part

Claims

A tensile strength wire, a primary coating layer that covers the outer periphery of the tensile strength wire, and a secondary coating layer that is coated so as to form a plurality of spiral grooves that are inverted at predetermined intervals along the longitudinal direction on the outer periphery of the primary coating layer In a slot for an optical fiber cable having
A slot for an optical fiber cable, wherein the outer peripheral portion of the primary coating layer has a shape provided with a protrusion along a portion corresponding to a base of a rib portion formed between the spiral grooves of the secondary coating layer.

2. The slot for an optical fiber cable according to claim 1, wherein a diameter d3 of a circumscribed circle at a tip of the protrusion on the outer periphery of the primary coating layer, a diameter d2 of an inscribed circle at the bottom of the spiral groove, and the secondary coating layer The outermost diameter d4 is
d2 <d3 <d4
A slot for an optical fiber cable characterized by satisfying the above relationship.

2. The slot for an optical fiber cable according to claim 1, wherein a diameter d3 of a circumscribed circle at a tip of the protrusion on the outer periphery of the primary coating layer, a diameter d2 of an inscribed circle at the bottom of the spiral groove, and the secondary coating layer The outermost diameter d4 is
d2 + 0.1 (d4-d2) <d3 <d4-0.5 (d4-d2)
A slot for an optical fiber cable characterized by satisfying the above relationship.

A primary coating layer forming apparatus that has a die portion having a rotation control mechanism and forms a primary coating layer having a plurality of spiral protrusions that are inverted at predetermined intervals over the longitudinal direction on the outer peripheral portion of the tensile strength line;
A detection device for detecting a trajectory drawn in the longitudinal direction by the protrusion on the outer periphery of the primary coating layer formed by the primary coating layer forming device;
A plurality of dice portions that rotate following the trajectory drawn in the longitudinal direction by the spiral projections on the outer periphery of the primary coating layer detected by the detection device, and are inverted at predetermined intervals along the longitudinal direction on the outer periphery of the primary coating layer. An apparatus for producing a slot for an optical fiber cable, comprising: a secondary coating layer forming device for forming a secondary coating layer having a spiral groove of

A primary coating layer forming apparatus that has a die portion having a rotation mechanism and forms a primary coating layer having a plurality of spiral projections that are inverted at predetermined intervals over the longitudinal direction on the outer peripheral portion of the tensile strength line;
A secondary coating that is disposed downstream of the primary coating layer forming apparatus, has a dice portion equipped with a rotation mechanism, and has a plurality of spiral grooves that are inverted at predetermined intervals over the longitudinal direction on the outer peripheral portion of the primary coating layer. A secondary coating layer forming device for forming a layer;
An apparatus for manufacturing a slot for an optical fiber cable, comprising a control device for controlling the rotation mechanisms of the primary and secondary coating layer forming devices in association with each other.

A primary coating layer forming apparatus that has a die portion having a rotation mechanism and forms a primary coating layer having a plurality of spiral projections that are inverted at predetermined intervals over the longitudinal direction on the outer peripheral portion of the tensile strength line;
A secondary coating layer that is disposed downstream of the primary coating layer forming device, has a fixed die portion, and has a plurality of spiral grooves that are inverted at predetermined intervals in the longitudinal direction on the outer peripheral portion of the primary coating layer. A secondary coating layer forming device ;
A light comprising: a holding mechanism that holds the slot and is disposed at a distance from the secondary coating layer forming apparatus at a front stage and a rear stage of the secondary coating layer forming apparatus, or only at the front stage. Fiber cable slot manufacturing equipment.

The diameter d3 of the circumscribed circle at the tip of the protrusion on the outer periphery of the primary coating layer, the diameter d2 of the inscribed circle at the bottom of the spiral groove, and the diameter d4 of the outermost periphery of the secondary coating layer,
d2 <d3 <d4
The primary coating layer forming device forms the primary coating layer and the secondary coating layer forming device forms the secondary coating layer so as to satisfy the above relationship. Manufacturing equipment for optical fiber cable slots.

A primary coating layer having a plurality of spiral projections that are inverted at predetermined intervals over the longitudinal direction is formed on the outer peripheral portion of the tensile strength wire using a die portion having a rotation control mechanism, and the projections on the outer peripheral portion of the primary coating layer A secondary coating having a plurality of spiral grooves that are reversed at predetermined intervals over the longitudinal direction on the outer peripheral portion of the primary coating layer using a die portion that detects a locus drawn in the longitudinal direction and rotates following the locus. A method of manufacturing a slot for an optical fiber cable, comprising forming a layer.

A primary coating layer having a plurality of spiral protrusions that are inverted at predetermined intervals over the longitudinal direction is formed on the outer peripheral portion of the tensile strength wire using a die portion having a rotating mechanism, and then the rotating mechanism is formed on the outer peripheral portion of the primary coating layer. Forming a secondary coating layer having a plurality of spiral grooves that are inverted at predetermined intervals in the longitudinal direction using a dice portion including: and controlling the rotational motion of the dice portion in association with each other. Manufacturing method of slot for optical fiber cable.

A primary coating layer having a plurality of spiral protrusions that are inverted at predetermined intervals over the longitudinal direction is formed on the outer peripheral portion of the tensile strength wire using a die portion having a rotating mechanism, and then a fixed die is formed on the outer peripheral portion of the primary coating layer. And forming a secondary coating layer having a plurality of spiral grooves that are inverted at predetermined intervals over the longitudinal direction, and before and after forming the secondary coating layer or before forming the secondary coating layer. A slot for an optical fiber cable , wherein the slot is gripped by using a gripping mechanism disposed at a distance from the portion .

The diameter d3 of the circumscribed circle at the tip of the protrusion on the outer periphery of the primary coating layer, the diameter d2 of the inscribed circle at the bottom of the spiral groove, and the diameter d4 of the outermost periphery of the secondary coating layer,
d2 <d3 <d4
The method of manufacturing a slot for an optical fiber cable according to claim 10, wherein the primary coating layer and the secondary coating layer are formed so as to satisfy the relationship.