JP3746681B2

JP3746681B2 - Optical cable laying method in sewer pipes

Info

Publication number: JP3746681B2
Application number: JP2001023164A
Authority: JP
Inventors: 明良関口; 政雄末広; 隆好志村; 宏野地; 明弘木村
Original assignee: 日本コムシス株式会社
Priority date: 2001-01-31
Filing date: 2001-01-31
Publication date: 2006-02-15
Anticipated expiration: 2021-01-31
Also published as: JP2002233016A

Description

【０００１】
【発明の属する技術分野】
この発明は、下水道を利用して光ファイバケーブル（以下「光ケーブル」という。）を敷設する際に用いられる敷設方法に関するものである。
【０００２】
【従来の技術】
近年、下水道を利用して、光ケーブルの基線ケーブル網を構築するとともにその基線ケーブル網から光ケーブルを建物まで敷設することで、各家庭や企業での高速大容量通信を可能にする計画が進められているが、下水道のマンホールから建物までの下水道管は、マンホール間に延在する本管でも直径３００ｍｍ程度、本管と建物付近の公共ますとを繋ぐ取付管では直径１５０ｍｍ程度の空間で、人が入ることができない。
【０００３】
このため、下水道管のうちでもそれら本管や取付管内への光ケーブルの敷設には、下水道管の内壁頂部に特殊な工具を使用して取り付けた金具や硬化性樹脂等で光ケーブルを固定するといった方法が検討されている。また、直径の大きな下水道管幹線部分では、ロボットや人手により、下水道管の内壁頂部にネジ留め金具で光ケーブルを固定するといった方法がとられている。
【０００４】
【発明が解決しようとする課題】
しかしながら、マンホールと建物付近の公共ますとの間に延在する、上記下水道管の本管や取付管内に光ケーブルを敷設する場合には、単に光ケーブルをその管内に通しただけでは、下水流を妨げたり下水道の保守に支障を来したりして、下水道本来の機能が損なわれる可能性がある。
【０００５】
また、光ケーブルの本来の機能を維持するためには、光ケーブルを下水流や急な曲がりから保護する必要がある。
【０００６】
それゆえこの発明は、下水道管のうちでも上記のように細い本管や取付管内へ光ケーブルを、ロボットのような複雑で高価な装置や特殊な材料を使用することなく簡単にかつ下水流を妨げたり下水道の保守に支障を来したりせずに敷設することができる方法を提供し、さらに、光ケーブルを下水流や急な曲がりから保護することができる方法を提供することを目的とする。
【０００７】
【課題を解決するための手段およびその作用・効果】
上記課題を有利に解決したこの発明の下水道内光ケーブル敷設方法は、マンホールと建物付近の公共ますとの間に延在する下水道管内に光ケーブルを敷設するに際し、前記マンホールおよび公共ますの下水道管口にそれぞれ、その下水道管口の内周面に嵌まり合うとともに下部が切り欠かれた嵌合部と、その下水道管口の外側部分に掛合するフランジ部とを有する引き止め金具を設け、前記マンホールおよび公共ますの下水道管口にそれぞれ設けた前記引き留め金具の上部に、前記下水道管内に通すとともに張力を与えた光ケーブルの対応する部分をそれぞれ固定することで、前記張力により前記引き留め金具を前記下水道管口に固定しつつ、それらの引き留め金具の間に前記光ケーブルを張り渡すことを特徴とするものである。
【０００８】
かかる敷設方法によれば、マンホールと建物付近の公共ますとの下水道管口にそれぞれ設けた、下水道管口の内周面に嵌まり合うとともにその下水道管口の外側部分に掛合する、下部が切り欠かれた引き留め金具の上部に、それらマンホールと公共ますとの間に延在する下水道管内に通すとともに張力を与えた光ケーブルの、それら引き留め金具と対応する部分をそれぞれ固定することで、それらの引き留め金具間に光ケーブルを張り渡すので、下水道管の内壁上部からの光ケーブルの離間を最小限にし得て、下水道管のうちでも細い本管や取付管内へ光ケーブルを、複雑で高価な装置や特殊な材料を使用することなく簡単に、かつ下水流を妨げたり下水道の保守に支障を来したりせずに敷設することができ、しかも光ケーブルを下水流から保護することができる。
【０００９】
なお、この発明の敷設方法においては、前記下水道管の急な曲がり部に位置させる光ケーブルの所定位置に、その光ケーブルの許容曲げ半径以上の半径の光ケーブル保持部を有する許容曲げ半径保障部材をあらかじめ取り付けておき、前記光ケーブルを引き込むことで前記許容曲げ半径保障部材を前記急な曲がり部に配置することとしてもよく、このようにすれば、マンホールと公共ますとの間に延在する下水道管の本管から取付管への分岐部等に急な曲がり部がある場合でも、光ケーブルを急な曲がりから保護することができる。
【００１０】
また、この発明の敷設方法においては、前記公共ますとそれより下流側のマンホールとの間に延在する下水道管内に光ケーブルを通す際に、浮き部材と水流抵抗部材とを持つ先端治具を通線紐の先端に接続し、その先端治具を前記公共ますから水流により前記下流側のマンホールへ前記通線紐を繰り出しながら流すことで、前記公共ますと前記下流側のマンホールとの間に前記通線紐を通し、その通線紐に光ケーブルの一端部を接続してその通線紐を引くこととしてもよく、このようにすれば、公共ますとそれより下流側のマンホールとの間の、下水道管のうちでも細い本管や取付管内に光ケーブルを、複雑で高価な装置や特殊な材料を使用することなく簡単に通すことができる。
【００１１】
さらに、この発明の敷設方法においては、前記公共ますとそれより上流側のマンホールとの間に延在する下水道管内に光ケーブルを通す際に、浮き部材と水流抵抗部材と磁石または磁性体とを持つ先端治具を通線紐の先端に接続し、その先端治具を前記公共ますから水流により前記上流側のマンホールからの下水道管との合流位置まで前記通線紐を繰り出しながら流すとともに、その上流側のマンホールから前記合流位置まで、前記磁石または磁性体に磁力で吸着する引き込み装置を挿入し、前記通線紐を繰り出しながらその引き込み装置で前記先端治具を引き寄せることで、前記公共ますと前記上流側のマンホールとの間に前記通線紐を通し、その通線紐に光ケーブルの一端部を接続してその通線紐を引くこととしてもよく、このようにすれば、公共ますとそれより上流側のマンホールとの間の、下水道管のうちでも細い本管や取付管内に光ケーブルを、複雑で高価な装置や特殊な材料を使用することなく簡単に通すことができる。ここで、前記引き込み装置としては、例えばある程度の太さのワイヤの先端に強力な磁石を取り付けたもの等を用いることができる。
【００１２】
またこの発明の敷設方法は、二つのマンホールの間に延在する下水道管内に光ケーブルを敷設するに際し、前記二つのマンホールの下水道管口にそれぞれ、その下水道管口の内周面に嵌まり合うとともに下部が切り欠かれた嵌合部と、その下水道管口の外側部分に掛合するフランジ部とを有する引き止め金具を設け、前記二つのマンホールの下水道管口にそれぞれ設けた前記引き留め金具の上部に、前記下水道管内に通すとともに張力を与えた光ケーブルの対応する部分をそれぞれ固定することで、前記張力により前記引き留め金具を前記下水道管口に固定しつつ、それらの引き留め金具の間に前記光ケーブルを張り渡すことを特徴とするものである。
【００１３】
かかる敷設方法によれば、二つのマンホールの下水道管口にそれぞれ設けた、下水道管口の内周面に嵌まり合うとともにその下水道管口の外側部分に掛合する、下部が切り欠かれた引き留め金具の上部に、それらのマンホールの間に延在する下水道管すなわち本管内に通すとともに張力を与えた光ケーブルの、それら引き留め金具と対応する部分をそれぞれ固定することで、それらの引き留め金具間に光ケーブルを張り渡すので、下水道管の内壁上部からの光ケーブルの離間を最小限にし得て、下水道管のうちでも細い本管内へ光ケーブルを、複雑で高価な装置や特殊な材料を使用することなく簡単に、かつ下水流を妨げたり下水道の保守に支障を来したりせずに敷設することができ、しかも光ケーブルを下水流から保護することができる。
【００１４】
なお、この発明の敷設方法においては、建物付近の公共ますから前記二つのマンホール間の下水道管に至る下水道管内に前記公共ますから通した通線紐で、前記二つのマンホール間の下水道管内に通した光ケーブルを中間位置で支持する中間支持部材を吊り上げて、前記公共ますからの下水道管の位置にて前記二つのマンホール間の下水道管の内壁上部に固定することとしてもよい。
【００１５】
かかる敷設方法によれば、二つのマンホール間のスパンが長くて、張力のみでは中間位置で光ケーブルに多少弛みが生ずるような場合に、光ケーブルをその中間位置にて、下水道管の内壁上部に固定した中間支持部材で支持し得て、光ケーブルと下水道管の内壁との間の距離を最小限に維持することができる。
【００１６】
そしてこの発明の敷設方法においては、前記二つのマンホール間の下水道管内に通した光ケーブルに対し前記中間支持部材を摺動させることで、前記中間支持部材を前記公共ますからの下水道管の位置に配置することとしてもよく、また前記二つのマンホール間の下水道管内に通した光ケーブルの所定位置に前記中間支持部材をあらかじめ固定しておき、その光ケーブルを移動させることで、前記中間支持部材を前記公共ますからの下水道管の位置に配置してもよい。
【００１７】
【発明の実施の形態】
以下に、この発明の実施の形態を実施例によって、図面に基づき詳細に説明する。ここに、図１（ａ）は、この発明の下水道内光ケーブル敷設方法の一実施例による光ケーブルの敷設状態の概要を示す透視図、図１（ｂ）は、（ａ）の本管から取付管への分岐部を示す断面図、図１（ｃ）は、本管内の光ケーブルの保持方法を示す斜視図であり、図中符号１はマンホール、２は建物付近の公共ます、３は二つのマンホール１の間に延在する下水道管である本管、４はその本管３と公共ます２との間に延在する下水道管である取付管をそれぞれ示す。
【００１８】
また図中符号５は本管３内に敷設した光ケーブルである配線ケーブル、６はその配線ケーブル５からマンホール１内で分岐させて本管３および取付管４内を通し公共ます２まで敷設した光ケーブルである引込みケーブル、７はマンホール１の下水道管口に設けたマンホール用引き留め金具、８は公共ます２の下水道管口に設けた公共ます用引き留め金具、９は引込みケーブル６に設けた許容曲げ半径保障部材をそれぞれ示す。
【００１９】
そして図中符号１０は本管３の中間位置で配線ケーブル５を支持する筒状の中間支持部材、１１は図１ではその中間支持部材１０を本管３の内壁上部に固定している通線紐、１２はそれら引込みケーブル６および通線紐１１を取付管４の内壁上部に固定している弾性環状板をそれぞれ示す。
【００２０】
先ず、図１に示す光ケーブルのうちの一方である引込みケーブル６の敷設作業手順について説明すると、この実施例の敷設方法では最初に、図２に示す如く、発泡スチロール製の球状の浮き部材１３と合成ゴム製の円板状の水流抵抗部材１４とを例えば複数ずつ交互に配置した状態でそれらにワイヤ１５を、挿通して構成した先端治具１６のワイヤ１５の後端部を、通常の通線紐１１の先端に撚り戻し１７を介して接続する。かかる先端治具１６は、水に入れると水面１８付近に浮遊して、水流に対し充分な抵抗を持つとともに下水道管内の下部に溜まった汚泥等に引っ掛からずに水流で流されることができる。
【００２１】
次いで、この先端治具１６を、公共ます２から取付管４内に入れて、通線紐１１を繰り出しながら本管３内まで、図３に示す給水車１９等からの流水により流し込む。そしてその公共ます２からそれよりも下流側のマンホール１に引込みケーブル６を敷設する場合は、さらに図３に示すように、本管３内も給水車１９等からの流水により、下流側のマンホール１まで先端治具１６を流す。その後は、下流側のマンホール１に先端治具１６とともに到達した通線紐１１の先端に引込みケーブル６の端部を接続して、公共ます２から通線紐１１を引くことにより、引込みケーブル６をマンホール１から、公共ます２とマンホール１との間の本管３および取付管４内に通す。
【００２２】
一方、公共ます２からそれよりも上流側のマンホール１に引込みケーブル６を敷設する場合は、ワイヤ１５の先端部に磁石または磁性体を取り付けた上記先端治具１６を、公共ます２から取付管４内に入れ、通線紐１１を繰り出しながら図４中矢印で示すように水流で流し込んで本管３内に到達させ、その一方で上流側のマンホール１から本管３内に、例えば押し進められる程度の太さのワイヤ２０の先端に強力な磁石２１を取り付けた引込み装置２２を挿入し、その磁石２１の磁力で先端治具１６の磁石または磁性体を吸着してワイヤ２０で先端治具１６を上流側のマンホール１まで引き寄せる。その後は、上流側のマンホール１に先端治具１６とともに到達した通線紐１１の先端に引込みケーブル６の端部を接続して、公共ます２から通線紐１１を引くことにより、引込みケーブル６を公共ます２とマンホール１との間の本管３および取付管４内に通す。
【００２３】
次にこの実施例の敷設方法では、図１に示すように、公共ます２内に開口している下水道管口に、図５（ａ）の斜視図および図５（ｂ）の正面図に示す如き公共ます用引き留め金具８を嵌着するとともに、マンホール１内に開口している下水道管口に、図６（ａ）の斜視図および図６（ｂ）の正面図に示す如きマンホール用引き留め金具７を嵌着する。
【００２４】
マンホール用引き留め金具７と公共ます用引き留め金具８とは、何れも鋼の厚板にて形成されていて、下水道管（マンホール用引き留め金具７では本管３、公共ます用引き留め金具８では取付管４）の口の内周面に沿って周方向に延在しその下水道管口に嵌まり合うとともに下部が切り欠かれた半円以上の部分円筒状の嵌合部２３と、その嵌合部２３の軸線方向端部と一体をなすとともに上記軸線に関し互いに概略反対方向の半径方向外方へ突出して下水道管口の外側のマンホール１や公共ます２の内壁に掛合する二つの掛止フランジ部２４と、それらの掛止フランジ部２４の間の位置にて嵌合部２３の軸線方向端部と一体をなすとともに上記軸線に関し半径方向外方へ突出してマンホール１や公共ます２の内壁に掛合する引き留めフランジ部２５とを有している。
【００２５】
そして、公共ます用引き留め金具８では図５に示すように、引き留めフランジ部２５に三本のメッセンジャワイヤ巻付けボルト２６が螺着され、またマンホール用引き留め金具７では図６に示すように、引き留めフランジ部２５に三本のメッセンジャワイヤ巻付けボルト２６が螺着されるとともにメッセンジャワイヤクリップ２７が設けられている。さらに、マンホール用引き留め金具７では、図２２にも示すように、嵌合部２３の周方向中央部の内面にメッセンジャワイヤ固定部材２８が固設されており、そのメッセンジャワイヤ固定部材２８にはマンホール１側へ向かうにつれて拡径する裁頭円錐状の楔孔２８ａが形成されている。
【００２６】
また、この実施例の敷設方法では、図１に示すように、マンホール１と公共ます２との間の距離から推測される本管３と取付管４との分岐部の位置に対応する引込みケーブル６の位置に、図７に示す如き、その引込みケーブル６の許容曲げ半径以上の半径Ｒｍを持つとともに両端部分で引込みケーブル６を下水道管内壁から僅かな距離ｄしか離間させない光ケーブル保持部９ａを有する許容曲げ半径保障部材９をあらかじめ装着しておいて、上記マンホール１と公共ます２との間の下水道管内への引込みケーブル６の挿通を行う。なお、本管３への取付管４の取り付け角度が直角でなかったり、取り付け部に大きな丸め半径がつけられていたりして、引込みケーブル６が許容曲げ半径より小さく曲げられる可能性がない場合には、許容曲げ半径保障部材９の装着を省略することもできる。
【００２７】
図８〜図１１は、この許容曲げ半径保障部材９の一例を示し、図８（ａ）は、その例の許容曲げ半径保障部材９の、組み立てて引込みケーブル６に装着した状態での部分断面正面図、図８（ｂ）は、その例の許容曲げ半径保障部材９の側面図、図８（ｃ）は、その例の許容曲げ半径保障部材９の、図８（ａ）のＡ−Ａ線に沿う断面図、図８（ｄ）は、その例の許容曲げ半径保障部材９の、図８（ａ）のＢ−Ｂ線に沿う断面図である。
【００２８】
上記例の許容曲げ半径保障部材９は、図９（ａ）の正面図および図９（ｂ）の側面図に示す如き内側部材２９と、図１０の正面図に示す如き外側部材３０とからなり、内側部材２９は、例えばクロロプレンスポンジ等からなるとともに、中間部の外側（図では上側）の溝２９ａと、中間部の内側の楔形の複数の切込み２９ｂと、両端部の外側に凹曲面を持つ差込み部２９ｃとを有しており、また外側部材３０は、例えば合成ゴム等の弾性的に伸びる素材からなるとともに、上記差込み部２９ｃの凹曲面に引込みケーブル６分の隙間をあけて対向する凸曲面を持つ両端部の差込み孔３０ａと、上記溝２９ａと嵌まり合う突条を持つ中間部の帯状蓋部３０ｂとを有している。
【００２９】
かかる許容曲げ半径保障部材９は、図１１（ａ）に示すように、あらかじめ外側部材３０の両端部の差込み孔３０ａに引込みケーブル６を挿通して外側部材３０を上記配置位置に概ね位置させておいて、同図中矢印Ｃで示すようにその外側部材３０の一端部の差込み孔３０ａに内側部材２９の一端部の差込み部２９ｃを内側から差し込み、次いで図１１（ｂ）中矢印Ｄで示すように、帯状蓋部３０ｂを引き伸ばして外側部材３０の他端部の差込み孔３０ａに内側部材２９の他端部の差込み部２９ｃを内側から差し込むことで、引込みケーブル６に装着することができ、また通常は概略直線状をなしていて下水道管内への引込みケーブル６の挿通を容易にしているが、上記配置位置にて引込みケーブル６に張力が与えられて曲げられた場合には、内側部材２９の内側の楔形の複数の切込み２９ｂの両壁が当接することで所定以上小さい半径への曲がりを規制する。従って、この例の許容曲げ半径保障部材９の、内側部材２９と外側部材３０との間に形成される通路は、引込みケーブル６の許容曲げ半径以上の半径Ｒｍの光ケーブル保持部９ａとなる。なお、この許容曲げ半径保障部材９は装着後も引込みケーブル６上でずらして装着位置を調整することができる。
【００３０】
図１２は、上記実施例の敷設方法で用い得る許容曲げ半径保障部材９の他の一例を示し、図１２（ａ）は、その例の許容曲げ半径保障部材９の、引込みケーブル６への装着前の状態での正面図、図１２（ｂ）は、その例の許容曲げ半径保障部材９の、引込みケーブル６への装着後の状態での正面図、図１２（ｃ）は、その例の許容曲げ半径保障部材９の、下水道管の本管３と取付管４との分岐部への配置状態での正面図である。
【００３１】
この例の許容曲げ半径保障部材９は、金属製あるいはプラスチック製の帯板をスパイラル状に巻いて形成した概略１ｍの長さのいわゆるフレキ管からなり、通常は直線状をなしていて下水道管内への引込みケーブル６の挿通を容易にしているが、上記配置位置にて引込みケーブル６に張力が与えられて曲げられた場合には、曲げ内側の帯板部分同士が当接することで所定以上小さい半径への曲がりを規制する。従って、引込みケーブル６が挿通されたこの例の許容曲げ半径保障部材９の中心孔は、図１２（ｃ）に示すように、引込みケーブル６の許容曲げ半径以上の半径Ｒｍの光ケーブル保持部９ａとなる。
【００３２】
マンホール用引き留め金具７と公共ます用引き留め金具８との下水道管口への嵌着と、概略所定位置に許容曲げ半径保障部材９を装着した引込みケーブル６の下水管内への挿通とが済んだら、引込みケーブル６を適宜出入りさせて許容曲げ半径保障部材９を本管３と取付管４との分岐部に位置させてから、図１３（ａ）に示すように、公共ます２から取付管４内に遠隔操作式移動治具３１を挿入し、図１４（ｂ）に示す如く両端部に掛合孔３２ａを持つ弾性平板（後述の弾性環状板の素材ゆえそれと同一符号で示す）３２の両端部を丸めた弾性板（後述の弾性環状板の素材ゆえそれと同一符号で示す）３２をさらに図１４（ｃ）に示すように丸めた弾性環状板３２を、図１４（ｄ）の左側に示すように弾性的に縮径状態にして遠隔操作式移動治具３１により取付管４内の任意の位置に運んで、その位置で解放し、図１４（ｄ）の左側に示すように弾性力で拡径させることで、図１４（ａ）に示すように、その弾性環状板３２と取付管４の管壁との間に引込みケーブル６を挟持する。
【００３３】
上記遠隔操作式移動治具３１としてここでは、例えば両端部の掛合孔３２ａにピンを掛合させて弾性環状板３２を縮径状態で保持し得るとともに解放して拡径させ得る電動式の図示しないプライヤ状ハンドを電動式の模型自動車の如き台車に搭載したものを用いているが、手動ワイヤ操作式等の他の構成の遠隔操作式移動治具３１を用いることもできる。
【００３４】
かかる作業を繰り返すことで、図１３（ｂ），（ｃ）に示すように、本管３側から順次、複数の弾性環状板３２を配置して、取付管４の管壁に添わせて引込みケーブル６を固定した後は、引込みケーブル６に適当な張力を与えた状態で、図１５（ａ）およびその一部を拡大した図１５（ｂ）に示すように、その引込みケーブル６のケーブル芯線６ａから分離させたメッセンジャワイヤ６ｂを公共ます２内の公共ます用引き留め金具８の三本のメッセンジャワイヤ巻付けボルト２６に巻き付けてそれらのボルト２６を締め込むことで、引込みケーブル６の、公共ます用引き留め金具８に隣接する部分（対応する部分）を公共ます用引き留め金具８に固定するとともに、図１６に示すように、上記と同様その引込みケーブル６のメッセンジャワイヤ６ｂをマンホール１内のマンホール用引き留め金具７の三本のメッセンジャワイヤ巻付けボルト２６に巻き付けてそれらのボルト２６を締め込むことで、引込みケーブル６の、マンホール用引き留め金具７に隣接する部分（対応する部分）をマンホール用引き留め金具７に固定する。なお、図１６ではケーブル芯線６ａに図１２に示す例の許容曲げ半径保障部材９が装着されてケーブル芯線６ａを保護している。
【００３５】
次に、図１に示す光ケーブルのうちのもう一方である配線ケーブル５の敷設作業手順について説明すると、この実施例の敷設方法では、先ず、上流側のマンホール１よりも上流側の本管３を閉塞し、図１７および図１８に示すように、通線紐１１を接続した上記先端治具１６を、その上流側のマンホール１から本管３内に入れて、通線紐１１を繰り出しながら、図３に示す給水車１９等からの流水により下流側のマンホール１まで流すとともに、それら二つのマンホール１の間の本管３に繋がった取付管４の先の公共ます２からも、通線紐１１を接続した上記先端治具１６を本管３内に入れて、通線紐１１を繰り出しながら、同様にして流水により下流側のマンホール１まで流す。
【００３６】
その後は、図１９に示すように、上流側のマンホール１と下流側のマンホール１との本管３の口にそれぞれマンホール用引き留め金具７を、上述したと同様にして嵌着し、次いで、図２０に示すように、上流側（図では左側）のマンホール１から下流側のマンホール１に先端治具１６とともに到達した通線紐１１の後端に、上流側のマンホール１付近に配置したケーブルドラム３３に巻かれた配線ケーブル５の端部を接続具３４で接続して、下流側のマンホール１から通線紐１１を引くことにより、配線ケーブル５を上流側と下流側との二つのマンホール１の間の本管３内に通す。
【００３７】
そしてその配線ケーブル５を先に述べた筒状の中間支持部材１０に挿通し、その中間支持部材１０を、途中の公共ます２から下流側のマンホール１に先端治具１６とともに到達した通線紐１１の先端に接続して、図２１中一点鎖線で示すように公共ます２から通線紐１１を引くことにより、図２１中矢印Ｅで示すように中間支持部材１０を配線ケーブル５に沿って取付管４の位置まで移動させ、その後、通線紐１１をさらに引くことにより、図２１および図１（ｃ）に実線で示すように通線紐１１が取付管４の方に中間支持部材１０を引き上げて、図１（ａ）および（ｂ）と図１７とに示すように、中間支持部材１０を本管３の内壁上部の取付管４の口に架け渡し、中間支持部材１０の両端部をその取付管口に掛合させることで、中間支持部材１０ひいてはそこに挿通した配線ケーブル５を本管３の内壁上部の取付管口に固定する。なお、公共ます２からの通線紐１１は、上述した取付管４の内壁への引込みケーブル６の固定用の弾性環状板３２によって引込みケーブル６と一緒に取付管４の内壁に添わせ、その通線紐１１の上端部は、引込みケーブル６のメッセンジャワイヤ６ｂと一緒に公共ます２内の公共ます用引き留め金具８に固定する。
【００３８】
次いで、図２２（ａ）に示すように、二つのマンホール１の間の本管３内に通した配線ケーブル５の一端部のケーブル芯線５ａから分離させたメッセンジャワイヤ５ｂを、一方のマンホール１内の図２２（ｂ）に示す如きマンホール用引き留め金具７のメッセンジャワイヤ固定部材２８の楔孔２８ａに図２２（ｃ）に示すように挿通して、そのメッセンジャワイヤ５ｂを複数分割した筒状の楔３４で挟み、その楔３４を楔孔２８ａ内に打ち込んで、メッセンジャワイヤ５ｂを楔３４で挟持しメッセンジャワイヤ固定部材２８に固定することで、配線ケーブル５の、一方のマンホール１内のマンホール用引き留め金具７に隣接する部分（対応する部分）をマンホール用引き留め金具７に固定し、楔孔２８ａから出たメッセンジャワイヤ５ｂの端部は、図２２（ｄ），（ｅ）に示すように上向きに折り曲げてマンホール用引き留め金具７のボルト締め式のメッセンジャワイヤクリップ２７で挟持する。
【００３９】
次いで、上記配線ケーブル５の他端部のケーブル芯線５ａから分離させたメッセンジャワイヤ５ｂを、他方のマンホール１内のマンホール用引き留め金具７のメッセンジャワイヤ固定部材２８の楔孔２８ａに図２３（ａ）に示すように挿通するとともに、図１７の右側のマンホール１内に示すように、その他方のマンホール１内に張線用治具３５を密にセットする。図２４（ａ）は、この張線用治具３５の一例を示す平面図、図２４（ｂ）は、その例の張線用治具３５の、（ａ）のＦ−Ｆ線に沿う断面図、図２４（ｃ）は、その例の張線用治具３５の、（ａ）のＧ−Ｇ線に沿う断面図であり、この例の張線用治具３５は、マンホール１の内部への挿入後に伸長し得るターンバックル３６ａを持つフレーム３６に金車３７を回転自在に支持してなるものである。
【００４０】
しかるのち、図２３（ａ）に示すように、マンホール用引き留め金具７のメッセンジャワイヤ固定部材２８の楔孔２８ａに通した上記メッセンジャワイヤ５ｂを上記張線用治具３５の金車３７に掛け回して上方へ向かわせ、マンホール１上に組んだ櫓に吊るした通常のラチェット式手動張線機３８で、そのメッセンジャワイヤ５ｂに図２３（ａ）中矢印Ｊで示すように張力を与えて、二つのマンホール１の間の本管３内に通した配線ケーブル５を本管３の内壁上部付近に張線し、その状態でメッセンジャワイヤ５ｂを複数分割した筒状の楔３４で挟み、その楔３４を図２３（ａ）中矢印Ｋで示すように楔孔２８ａ内に打ち込んで、メッセンジャワイヤ５ｂを楔３４で挟持しメッセンジャワイヤ固定部材２８に固定することで、配線ケーブル５に張力を持たせたまま、配線ケーブル５の、他方のマンホール１内のマンホール用引き留め金具７に隣接する部分（対応する部分）をマンホール用引き留め金具７に固定する。
【００４１】
そしてその後は、マンホール１内から張線用治具３５を撤去し、張線用治具３５から外したメッセンジャワイヤ５ｂを図２３（ａ），（ｂ）に示すように上向きに折り曲げてマンホール用引き留め金具７のボルト締め式のメッセンジャワイヤクリップ２７で挟持し、メッセンジャワイヤクリップ２７より先の余った部分は切断して除去する。これにより、二つのマンホール１の間の本管３内に配線ケーブル５を敷設することができる。
【００４２】
図２５（ａ）は、上記張線用治具３５の他の一例を示す平面図、図２５（ｂ）は、その例の張線用治具３５の、（ａ）のＨ−Ｈ線に沿う断面図、図２５（ｃ）は、その例の張線用治具３５の、（ａ）のＩ−Ｉ線に沿う断面図であり、この例の張線用治具３５は、マンホール１の内部への挿入後に組み立て得る組立式のフレーム３６に金車３７を回転自在に支持するとともに、そのフレーム３６の上部に油圧式のセンタホールジャッキ３８を立設し、そのセンタホールジャッキ３８をマンホール１外から手動油圧ポンプ３９で作動させるようにしてなるものである。かかる張線用治具３５によってもメッセンジャワイヤ５ｂに張力を与えることができる。
【００４３】
かかる実施例の敷設方法によれば、マンホール１と建物付近の公共ます２との下水道管口にそれぞれ設けた、下水道管口の内周面に嵌まり合うとともにその下水道管口の外側部分に掛合する、下部が切り欠かれた引き留め金具７，８の上部に、それらマンホール１と公共ます２との間に延在する下水道管である本管３および取付管４内に通すとともに張力を与えた引込みケーブル６の、それら引き留め金具７，８と対応する部分をそれぞれ固定することで、それらの引き留め金具間に光ケーブルとしての引込みケーブル６を張り渡すので、本管３および取付管４の内壁上部からの引込みケーブル６の離間を最小限にし得て、下水道管のうちでも細い本管３および取付管４内へ引込みケーブル６を、複雑で高価な装置や特殊な材料を使用することなく簡単に、かつ下水流を妨げたり下水道の保守に支障を来したりせずに敷設することができ、しかも引込みケーブル６を下水流から保護することができる。ちなみに、例えば１ｍ当たり１８ｇｗ程度の重量の引込みケーブル６の場合、３０ｋｇｆの張力をかければ、ほぼ弛みをなくすことができる。
【００４４】
また、この実施例の敷設方法によれば、下水道管内の本管３と取付管４との分岐部等に急な曲がり部がある場合に、その急な曲がり部に位置する引込みケーブル６の部分に、その引込みケーブル６の許容曲げ半径以上の半径の光ケーブル保持部を有する許容曲げ半径保障部材９を配置するので、引込みケーブル６を急な曲がりから保護することができる。
【００４５】
また、この実施例の敷設方法によれば、公共ます２とそれより下流側のマンホール１との間に延在する下水道管である本管３および取付管４内に光ケーブルとしての引込みケーブル６を通す際に、浮き部材１３と水流抵抗部材１４とを持つ先端治具１６を通線紐１１の先端に接続し、その先端治具１６を公共ます２から水流により下流側のマンホール１へ通線紐１１を繰り出しながら流すことで、公共ます２と下流側のマンホール１との間に通線紐１１を通し、その通線紐１１に引込みケーブル６の一端部を接続してその通線紐１１を引くので、公共ます２とそれより下流側のマンホール１との間の、下水道管のうちでも細い本管３および取付管４内に引込みケーブル６を、複雑で高価な装置や特殊な材料を使用することなく簡単に通すことができる。
【００４６】
さらに、この実施例の敷設方法によれば、公共ます２とそれより上流側のマンホール１との間に延在する下水道管である本管３および取付管４内に光ケーブルとしての引込みケーブル６を通す際に、浮き部材１３と水流抵抗部材１４と磁石または磁性体とを持つ先端治具１６を通線紐１１の先端に接続し、その先端治具１６を公共ます２から水流により上流側のマンホール１からの本管３との合流位置まで通線紐１１を繰り出しながら流すとともに、その上流側のマンホール１から上記合流位置まで、上記磁石または磁性体に磁力で吸着する引き込み装置２２を挿入し、上記通線紐１１を繰り出しながらその引き込み装置２２で先端治具１６を引き寄せることで、公共ます２と上流側のマンホール１との間に通線紐１１を通し、その通線紐１１に引込みケーブル６の一端部を接続してその通線紐１１を引くので、公共ます２とそれより上流側のマンホール１との間の、下水道管のうちでも細い本管３および取付管４内に引込みケーブル６を、複雑で高価な装置や特殊な材料を使用することなく簡単に通すことができる。
【００４７】
さらに、この実施例の敷設方法によれば、公共ます２とマンホール１との間に延在する下水道管内に引込みケーブル６を固定する際に、その下水道管のうちの取付管４内では、弾性環状板３２を縮径状態で遠隔操作式移動治具３１によって任意の位置に運んでその位置で解放し弾性力で拡径させることで、その弾性環状板３２と取付管４の内壁との間に引込みケーブル６を挟持するので、途中で曲がっている取付管４の場合でも、その取付管４内に引込みケーブル６を、複雑で高価な装置や特殊な材料を使用することなく簡単に、かつ下水流を妨げたり下水道の保守に支障を来したりせずに固定することができる。
【００４８】
さらに、この実施例の敷設方法によれば、二つのマンホール１の下水道管口にそれぞれ設けた、下水道管口の内周面に嵌まり合うとともにその下水道管口の外側部分に掛合する、下部が切り欠かれたマンホール用引き留め金具７の上部に、それらのマンホール１の間に延在する下水道管すなわち本管３内に通すとともに張力を与えた光ケーブルとしての配線ケーブル５の、それら引き留め金具７と対応する部分をそれぞれ固定することで、それらの引き留め金具７間に配線ケーブル５を張り渡すので、本管３の内壁上部からの配線ケーブル５の離間を最小限にし得て、下水道管のうちでも細い本管３内へ配線ケーブル５を、複雑で高価な装置や特殊な材料を使用することなく簡単に、かつ下水流を妨げたり下水道の保守に支障を来したりせずに敷設することができ、しかも配線ケーブル５を下水流から保護することができる。
【００４９】
ところで、例えば１ｍ当たり２００ｇｗ程度の重量の配線ケーブル５の場合には、張力をかけても５０ｍスパンで１００ｍｍ程度の弛みが発生するが、この実施例の敷設方法によれば、建物付近の公共ます２から二つのマンホール１間の下水道管である本管３に至る取付管４内に公共ます２から通した通線紐１１で、その本管３内に通した配線ケーブル５を中間位置で支持する中間支持部材１０を吊り上げて、公共ます２からの取付管４の位置にて二つのマンホール１間の本管３の内壁上部に固定するので、二つのマンホール１間のスパンが長くて、張力のみでは中間位置で配線ケーブル５に多少弛みが生ずるような場合でも、配線ケーブル５をその中間位置にて、本管３の内壁上部に固定した中間支持部材１０で支持し得て、配線ケーブル５と本管３の内壁との間の距離を最小限に維持することができる。
【００５０】
以上、図示例に基づき説明したが、この発明は上述の例に限定されるものでなく、例えば、引き留め金具７、８の材質、形状、掛止フランジ部２４やメッセンジャワイヤ巻付けボルト２６の数等を適宜変更することもでき、例えば、二個の掛止フランジ部２４と引き留めフランジ部２５との代わりに、下部が切り欠かかれた概略Ｃ字状の平板を用い、その平板にメッセンジャワイヤを固定するとともにその平板の内周部に軸線方向に延在して下水道管口の内周面と嵌合して引き留め金具を位置決めする複数のフランジを設けるようにしてもよい。
【００５１】
また、上記実施例では二つのマンホール１間の本管３内に通した配線ケーブル５に対して中間支持部材１０を摺動させることで、公共ます２からの取付管４の位置に中間支持部材１０を配置したが、二つのマンホール１間の本管３内に通した配線ケーブル５の所定位置にあらかじめ中間支持部材を固定しておき、その配線ケーブル５を移動させることで、公共ます２からの取付管４の位置に中間支持部材を配置することとしてもよい。
【００５２】
さらに、遠隔操作式移動治具３１にテレビカメラを搭載して、より適切に光ケーブルを固定できるようにしてもよく、また、許容曲げ半径保障部材９や引き込み装置２２や張線用治具３５等も、所要に応じて適宜変更することができる。
【図面の簡単な説明】
【図１】（ａ）は、この発明の下水道内光ケーブル敷設方法の一実施例による光ケーブルの敷設状態の概要を示す透視図、（ｂ）は、（ａ）の本管から取付管への分岐部を示す断面図、（ｃ）は、本管内の光ケーブルの保持方法を示す斜視図である。
【図２】上記実施例の敷設方法に用いる先端治具を例示する側面図である。
【図３】上記実施例の敷設方法のうち下流側への引込みケーブルの敷設方法を示す略線図である。
【図４】上記実施例の敷設方法のうち上流側への引込みケーブルの敷設方法を示す略線図である。
【図５】（ａ）は、上記実施例の敷設方法に用いる公共ます用引き留め金具を例示する斜視図、（ｂ）は、その例の公共ます用引き留め金具を示す正面図である。
【図６】（ａ）は、上記実施例の敷設方法に用いるマンホール用引き留め金具を例示する斜視図、（ｂ）は、その例のマンホール用引き留め金具を示す正面図である。
【図７】上記実施例の敷設方法に用いる許容曲げ半径保障部材を示す斜視図である。
【図８】（ａ）は、上記許容曲げ半径保障部材の一例を示す、組み立てて引込みケーブルに装着した状態での部分断面正面図、（ｂ）は、その例の許容曲げ半径保障部材の側面図、（ｃ）は、その例の許容曲げ半径保障部材の、（ａ）のＡ−Ａ線に沿う断面図、（ｄ）は、その例の許容曲げ半径保障部材の、（ａ）のＢ−Ｂ線に沿う断面図である。
【図９】（ａ）は、上記許容曲げ半径保障部材を構成する内側部材を示す正面図、（ｂ）は、その例の内側部材を示す側面図である。
【図１０】上記許容曲げ半径保障部材を構成する外側部材の正面図である。
【図１１】（ａ），（ｂ）は、上記許容曲げ半径保障部材の組立ておよび光ケーブルへの装着方法を示す斜視図である。
【図１２】（ａ）は、上記許容曲げ半径保障部材の他の一例を示す、引込みケーブルへの装着前の状態での正面図、（ｂ）は、その例の許容曲げ半径保障部材の、引込みケーブルへの装着後の状態での正面図、（ｃ）は、その例の許容曲げ半径保障部材の、下水道管の本管と取付管との分岐部への配置状態での正面図である。
【図１３】（ａ），（ｂ），（ｃ）は、上記実施例の敷設方法における弾性環状板の配置方法を示す略線図である。
【図１４】（ａ）は、上記環状弾性板の配置状態を示す正面図、（ｂ）および（ｃ）は、その環状弾性板の素材を示す斜視図、（ｄ）は、配置の際のその環状弾性板の拡径状態を示す説明図である。
【図１５】（ａ），（ｂ）は、上記公共ます用引き留め金具への引込みケーブルの固定状態を示す説明図である。
【図１６】上記マンホール用引き留め金具への引込みケーブルの固定状態を示す説明図である。
【図１７】上記実施例の敷設方法のうち配線ケーブルの敷設方法を示す透視図である。
【図１８】上記配線ケーブルの敷設方法における通線紐の通線方法を示す略線図である。
【図１９】上記マンホール用引き留め金具の嵌着方法を示す説明図である。
【図２０】上記配線ケーブルの敷設方法における配線ケーブルの通線方法を示す略線図である。
【図２１】上記配線ケーブルの敷設方法における中間支持部材の設置方法を示す略線図である。
【図２２】（ａ），（ｂ），（ｃ），（ｄ），（ｅ）は、上記マンホール用引き留め金具への配線ケーブルの固定方法を示す説明図である。
【図２３】（ａ），（ｂ）は、配線ケーブルに張線用治具で張力を与える方法および上記マンホール用引き留め金具への配線ケーブルの固定方法を示す説明図である。
【図２４】（ａ）は、上記張線用治具の一例を示す平面図、（ｂ）は、その例の張線用治具の、（ａ）のＦ−Ｆ線に沿う断面図、（ｃ）は、その例の張線用治具の、（ａ）のＧ−Ｇ線に沿う断面図である。
【図２５】（ａ）は、上記張線用治具の他の一例を示す平面図、（ｂ）は、その例の張線用治具の、（ａ）のＨ−Ｈ線に沿う断面図、（ｃ）は、その例の張線用治具の、（ａ）のＩ−Ｉ線に沿う断面図である。
【符号の説明】
１マンホール
２公共ます
３本管
４取付管
５配線ケーブル
６引込みケーブル
７マンホール用引き止め金具
８公共ます用引き止め金具
９許容曲げ半径保障部材
１０中間支持部材
１１通線紐
１２弾性環状板
１３浮き部材
１４水流抵抗部材
１５ワイヤ
１６先端治具
１７撚り戻し
１８水面
１９給水車
２０ワイヤ
２１磁石
２２引込み装置
２３嵌合部
２４掛止フランジ部
２５引き留めフランジ部
２６メッセンジャワイヤ巻付けボルト
２７メッセンジャワイヤクリップ
２８メッセンジャワイヤ固定部材
２９内側部材
３０外側部材
３１遠隔操作式移動治具
３２弾性環状板
３３ケーブルドラム
３４接続具
３５張線用治具
３６フレーム
３７金車
３８手動張線機
３９手動油圧ポンプ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laying method used when laying an optical fiber cable (hereinafter referred to as “optical cable”) using a sewer.
[0002]
[Prior art]
In recent years, plans have been made to enable high-speed and large-capacity communication in homes and businesses by constructing a base cable network for optical cables using the sewer and laying optical cables from the base cable network to the building. However, the sewer pipe from the sewer manhole to the building has a diameter of about 300 mm even in the main pipe extending between the manholes, and the installation pipe that connects the main and the public space near the building has a space of about 150 mm in diameter. I can't enter.
[0003]
For this reason, among the sewer pipes, for laying the optical cable in the main pipe and the mounting pipe, a method of fixing the optical cable with a metal fitting or a curable resin attached to the top of the inner wall of the sewer pipe using a special tool. Is being considered. Moreover, in the sewer pipe main line part with a large diameter, the method of fixing an optical cable with the screw fastener to the inner wall top part of a sewer pipe is taken with a robot or a hand.
[0004]
[Problems to be solved by the invention]
However, when laying an optical cable in the main or mounting pipe of the sewer pipe that extends between the manhole and the public mass near the building, simply passing the optical cable through the pipe prevents the sewage flow. There is a possibility that the original function of the sewerage may be impaired due to troubles in the maintenance of the sewerage.
[0005]
Further, in order to maintain the original function of the optical cable, it is necessary to protect the optical cable from sewage flow and sudden bends.
[0006]
Therefore, the present invention can prevent the sewage flow easily and without using a complicated and expensive device such as a robot or a special material in the thin main pipe or the mounting pipe as described above among the sewer pipes. It is an object of the present invention to provide a method capable of laying without disturbing the maintenance of sewage and further providing a method capable of protecting an optical cable from sewage flow or sudden bends.
[0007]
[Means for solving the problems and their functions and effects]
The method of laying an optical cable in a sewer according to the present invention that has advantageously solved the above-described problem is that, when an optical cable is laid in a sewer pipe extending between a manhole and a public basin near a building, Each of the manhole and the public is provided with a fitting that has a fitting portion that fits to the inner peripheral surface of the sewer pipe port and that has a notch at the bottom, and a flange portion that engages with an outer portion of the sewer pipe port. By fixing the corresponding portion of the optical cable that is passed through the sewer pipe and given tension to the upper part of the clasp provided at each sewer pipe port, the retainer metal fitting is connected to the sewer pipe port by the tension. The optical cable is stretched between the retaining metal fittings while being fixed.
[0008]
According to this laying method, the lower part of the manhole and the public sewer pipe in the vicinity of the building that fits on the inner peripheral surface of the sewer pipe and engages with the outer part of the sewer pipe is cut off. By fixing the portions of the optical cables that are passed through the sewer pipe extending between the manhole and the public mass and corresponding to the tension brackets to the upper portions of the missing brackets, respectively. The optical cable is stretched between the metal fittings, so that the optical cable can be kept away from the upper part of the inner wall of the sewer pipe, and the optical cable can be put into a thin main pipe or mounting pipe among the sewer pipes. Can be installed easily and without disturbing the sewage flow or disturbing the maintenance of the sewer, and the optical cable from the sewage flow. It is possible to protect.
[0009]
In the laying method of the present invention, an allowable bending radius ensuring member having an optical cable holding portion having a radius equal to or greater than the allowable bending radius of the optical cable is attached in advance to a predetermined position of the optical cable positioned at the sharp bend of the sewer pipe. In addition, the permissible bending radius securing member may be disposed at the steep bend by drawing the optical cable, and in this way, the main sewer pipe extending between the manhole and the public trough. Even when there is a sudden bend in the branching portion from the tube to the mounting tube, the optical cable can be protected from the sudden bend.
[0010]
Further, in the laying method of the present invention, when an optical cable is passed through the sewer pipe extending between the public mass and the manhole downstream of the public mass, a tip jig having a floating member and a water flow resistance member is passed. The wire is connected to the tip of the wire string, and the tip jig is flowed from the public wall to the downstream manhole by water flow while being drawn out, so that the wire is between the public wall and the downstream manhole. It is also possible to pass a wire string, connect one end of the optical cable to the wire string, and pull the wire line. In this way, between the public and the downstream manhole, Among sewer pipes, optical cables can be easily passed through thin main pipes and mounting pipes without using complicated and expensive equipment or special materials.
[0011]
Furthermore, in the laying method of the present invention, when the optical cable is passed through the sewer pipe extending between the public mass and the manhole on the upstream side, the floating member, the water flow resistance member, the magnet or the magnetic material are provided. The tip jig is connected to the tip of the wire string, and the tip jig is made to flow while feeding the wire string from the upstream manhole to the merging position with the sewer pipe by the water flow, and the upstream From the manhole on the side to the merging position, by inserting a retracting device that is magnetically attracted to the magnet or magnetic body, pulling the tip jig with the retracting device while drawing the wire string, It is also possible to pass the wire string between the upstream manhole, connect one end of the optical cable to the wire string, and pull the wire string. For example, an optical cable can be easily passed between a public main and an upstream manhole through a thin main pipe or mounting pipe among sewer pipes without using complicated and expensive equipment or special materials. it can. Here, as the drawing-in device, for example, a device in which a strong magnet is attached to the tip of a wire having a certain thickness can be used.
[0012]
The laying method of the present invention, when laying an optical cable in a sewer pipe extending between two manholes, fits into the sewer pipe port of the two manholes, respectively, and fits to the inner peripheral surface of the sewer pipe port. Provided with a retaining part having a fitting part with a lower part cut off and a flange part that engages with the outer part of the sewer pipe, on the upper part of the retaining part provided respectively in the sewer pipes of the two manholes, By fixing the corresponding portions of the optical cable that is passed through the sewer pipe and applied with tension, the optical cable is stretched between the retaining metal fittings while fixing the retaining metal fitting to the sewer pipe opening by the tension. It is characterized by this.
[0013]
According to such a laying method, the retaining metal fittings fitted to the inner peripheral surface of the sewer pipe port and hooked to the outer part of the sewer pipe port are provided at the two manhole sewer pipe ports, respectively. In the upper part of the optical cable, the portion of the optical cable that is passed through the sewer pipe extending between the manholes, that is, the main pipe and is tensioned, and the portion corresponding to the retaining bracket are fixed, so that the optical cable is connected between the retaining brackets. Because it is stretched out, the separation of the optical cable from the upper part of the inner wall of the sewer pipe can be minimized, and the optical cable can be easily put into the thin main pipe of the sewer pipe without using complicated and expensive equipment or special materials. Moreover, it can be laid without disturbing the sewage flow or disturbing the maintenance of the sewer, and can protect the optical cable from the sewage flow.
[0014]
In the laying method according to the present invention, a line string passed from the public mass into the sewer pipe from the public mass near the building to the sewer pipe between the two manholes, and is passed through the sewer pipe between the two manholes. An intermediate support member that supports the optical cable at an intermediate position may be lifted and fixed to the upper part of the inner wall of the sewer pipe between the two manholes at the position of the sewer pipe from the public mass.
[0015]
According to this laying method, when the span between two manholes is long and the optical cable is somewhat slacked at the intermediate position only by tension, the optical cable is fixed to the upper part of the inner wall of the sewer pipe at the intermediate position. It can be supported by an intermediate support member, and the distance between the optical cable and the inner wall of the sewer pipe can be kept to a minimum.
[0016]
And in the laying method of the present invention, the intermediate support member is slid to the optical cable passed through the sewer pipe between the two manholes, and the intermediate support member is disposed at the position of the sewer pipe from the public mass. The intermediate support member may be fixed to a predetermined position of the optical cable passed through the sewer pipe between the two manholes, and the intermediate support member is moved to the public by moving the optical cable. You may arrange in the position of the sewer pipe from.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, FIG. 1A is a perspective view showing an outline of an installed state of an optical cable according to an embodiment of an optical cable laying method in a sewer according to the present invention, and FIG. 1B is a main tube from FIG. Fig. 1 (c) is a perspective view showing a method of holding an optical cable in the main pipe. Reference numeral 1 is a manhole, 2 is a public near the building, and 3 is two manholes. 1 is a main pipe that is a sewer pipe extending between 1 and 4 is a mounting pipe that is a sewer pipe extending between the main pipe 3 and the public mass 2.
[0018]
In the figure, reference numeral 5 is a distribution cable which is an optical cable laid in the main pipe 3, and 6 is an optical cable which is branched from the distribution cable 5 in the manhole 1 and laid to the public 2 through the main pipe 3 and the mounting pipe 4. , 7 is a manhole retaining metal fitting provided at the sewer pipe of the manhole 1, 8 is a public metal retaining metal fitting provided at the sewer pipe of the public 2, and 9 is an allowable bending radius provided for the drawing cable 6. Each security member is shown.
[0019]
In the figure, reference numeral 10 denotes a cylindrical intermediate support member that supports the wiring cable 5 at an intermediate position of the main pipe 3, and reference numeral 11 denotes a line through which the intermediate support member 10 is fixed to the upper part of the inner wall of the main pipe 3 in FIG. A string 12 indicates an elastic annular plate for fixing the lead-in cable 6 and the wire string 11 to the upper part of the inner wall of the attachment tube 4.
[0020]
First, the procedure for laying the retractable cable 6 which is one of the optical cables shown in FIG. 1 will be described. In the laying method of this embodiment, first, as shown in FIG. For example, a plurality of rubber disk-shaped water flow resistance members 14 are alternately arranged, for example, and wires 15 are inserted therethrough, and the rear end portion of the wire 15 of the tip jig 16 configured by inserting the wires 15 is used as a normal wiring. Connected to the tip of the string 11 via a twistback 17. When the tip jig 16 is put in water, it floats in the vicinity of the water surface 18, has sufficient resistance to the water flow, and can be flowed in the water flow without being caught by sludge accumulated in the lower part of the sewer pipe.
[0021]
Next, the tip jig 16 is inserted into the attachment pipe 4 from the public trough 2, and poured into the main pipe 3 by running water from a water supply wheel 19 shown in FIG. Then, when the lead-in cable 6 is laid from the public mass 2 to the manhole 1 on the downstream side, the manhole on the downstream side of the main pipe 3 is also flown from the water truck 19 or the like as shown in FIG. The tip jig 16 is flowed to 1. Thereafter, the end of the lead-in cable 6 is connected to the tip of the wire string 11 that has reached the manhole 1 on the downstream side together with the tip jig 16, and the lead-in cable 6 is pulled by pulling the wire string 11 from the public grid 2. Is passed from the manhole 1 into the main pipe 3 and the mounting pipe 4 between the public mast 2 and the manhole 1.
[0022]
On the other hand, when the lead-in cable 6 is laid from the public trough 2 to the manhole 1 on the upstream side, the above-mentioned tip jig 16 having a magnet or a magnetic body attached to the tip of the wire 15 is attached to the mounting pipe from the public trough 2. 4, while drawing out the wire 11, the water is poured into the main pipe 3 as indicated by the arrow in FIG. 4, while being pushed forward from the upstream manhole 1 into the main pipe 3, for example. A pulling device 22 having a strong magnet 21 attached to the tip of a wire 20 having a thickness of a certain degree is inserted, and the magnet or magnetic body of the tip jig 16 is attracted by the magnetic force of the magnet 21 and the tip jig 16 is attracted by the wire 20. To the manhole 1 on the upstream side. Thereafter, the end of the lead-in cable 6 is connected to the leading end of the wire string 11 that has reached the upstream manhole 1 together with the tip jig 16, and the lead-in cable 6 is pulled by pulling the wire string 11 from the public grid 2. Is passed through the main pipe 3 and the mounting pipe 4 between the public bus 2 and the manhole 1.
[0023]
Next, in the laying method of this embodiment, as shown in FIG. 1, the sewer pipe opening opened in the public basin 2 is shown in the perspective view of FIG. 5 (a) and the front view of FIG. 5 (b). A sewer fitting 8 for a public mascot as shown above is fitted, and a sewer pipe opening opened in the manhole 1 is attached to a sewer pipe as shown in a perspective view of FIG. 6 (a) and a front view of FIG. 6 (b). 7 is inserted.
[0024]
The manhole retaining bracket 7 and the public trough retaining bracket 8 are both made of steel slabs. The sewer pipe (the main hole 3 for the manhole retaining bracket 7 and the mounting pipe for the public trough retaining bracket 8). 4) a semi-circular or more semi-circular fitting portion 23 that extends in the circumferential direction along the inner peripheral surface of the mouth and fits into the sewer pipe mouth and is cut out at the lower portion; and the fitting portion Two hooking flange portions 24 that are integrated with the axial end portion 23 and project outward in a radial direction substantially opposite to each other with respect to the above-described axial line and engage with the inner wall of the manhole 1 or the public trough 2 outside the sewer pipe port. And is integrated with the axial end of the fitting portion 23 at a position between the retaining flange portions 24 and protrudes outward in the radial direction with respect to the axial line to be engaged with the inner wall of the manhole 1 or the public mast 2. Retaining flange And a 25.
[0025]
As shown in FIG. 5, the three messenger wire winding bolts 26 are screwed onto the retaining flange portion 25 in the public holding clasp 8, and the manhole retaining bracket 7 is tightened as shown in FIG. 6. Three messenger wire winding bolts 26 are screwed to the flange portion 25 and a messenger wire clip 27 is provided. Further, as shown in FIG. 22, in the manhole retaining bracket 7, a messenger wire fixing member 28 is fixed to the inner surface of the center portion in the circumferential direction of the fitting portion 23, and the messenger wire fixing member 28 has a manhole. A truncated conical wedge hole 28a is formed which increases in diameter toward the one side.
[0026]
Moreover, in the laying method of this Example, as shown in FIG. 1, the lead-in cable corresponding to the position of the branch part of the main pipe 3 and the mounting pipe 4 estimated from the distance between the manhole 1 and the public mast 2 As shown in FIG. 7, an optical cable holding portion 9a having a radius Rm greater than the allowable bending radius of the lead-in cable 6 and separating the lead-in cable 6 from the inner wall of the sewer pipe by a slight distance d at both ends is provided at the position 6. The allowable bending radius guarantee member 9 is mounted in advance, and the lead-in cable 6 is inserted into the sewer pipe between the manhole 1 and the public slab 2. In addition, when the attachment angle of the attachment tube 4 to the main tube 3 is not a right angle or a large rounding radius is attached to the attachment portion, there is no possibility that the lead-in cable 6 is bent smaller than the allowable bending radius. The mounting of the allowable bending radius ensuring member 9 can be omitted.
[0027]
8 to 11 show an example of the allowable bending radius ensuring member 9, and FIG. 8A is a partial cross section of the allowable bending radius ensuring member 9 of the example in a state where it is assembled and attached to the retractable cable 6. FIG. 8B is a side view of the allowable bending radius ensuring member 9 of the example, and FIG. 8C is an AA view of the allowable bending radius ensuring member 9 of the example. FIG. 8D is a cross-sectional view taken along the line BB in FIG. 8A of the allowable bending radius ensuring member 9 of the example.
[0028]
The allowable bending radius ensuring member 9 in the above example includes an inner member 29 as shown in the front view of FIG. 9A and a side view of FIG. 9B, and an outer member 30 as shown in the front view of FIG. The inner member 29 is made of, for example, chloroprene sponge or the like, and has a groove 29a on the outer side (upper side in the figure), a plurality of wedge-shaped cuts 29b on the inner side of the intermediate portion, and a concave curved surface on the outer sides of both ends. The outer member 30 is made of an elastically extending material such as synthetic rubber, and has a convex surface that is opposed to the concave curved surface of the insertion portion 29c with a gap of the lead-in cable 6 therebetween. It has insertion holes 30a at both ends having curved surfaces, and an intermediate band-shaped lid portion 30b having a protrusion that fits into the groove 29a.
[0029]
As shown in FIG. 11A, the permissible bending radius ensuring member 9 is formed by inserting the lead-in cable 6 into the insertion holes 30a at both ends of the outer member 30 in advance so that the outer member 30 is generally positioned at the arrangement position. Then, as shown by an arrow C in the figure, an insertion portion 29c at one end of the inner member 29 is inserted from the inside into an insertion hole 30a at one end of the outer member 30, and then indicated by an arrow D in FIG. 11 (b). Thus, by extending the band-shaped lid portion 30b and inserting the insertion portion 29c of the other end portion of the inner member 29 into the insertion hole 30a of the other end portion of the outer member 30, it can be attached to the drawing cable 6. Moreover, it is generally straight and facilitates the insertion of the lead-in cable 6 into the sewer pipe. However, when the lead-in cable 6 is bent and tensioned at the arrangement position, A plurality of walls of the incision 29b inside the wedge-shaped inner member 29 regulates the bending of the abutment small predetermined or by radius. Accordingly, the passage formed between the inner member 29 and the outer member 30 of the allowable bending radius ensuring member 9 of this example is an optical cable holding portion 9a having a radius Rm greater than the allowable bending radius of the lead-in cable 6. The allowable bending radius ensuring member 9 can be shifted on the lead-in cable 6 after installation to adjust the mounting position.
[0030]
FIG. 12 shows another example of the allowable bending radius ensuring member 9 that can be used in the laying method of the above embodiment, and FIG. 12A shows the mounting of the allowable bending radius ensuring member 9 of the example to the retractable cable 6. FIG. 12B is a front view in the previous state, FIG. 12B is a front view in a state after the allowable bending radius ensuring member 9 of the example is attached to the retractable cable 6, and FIG. It is a front view in the arrangement state to the branch part of main pipe 3 and attachment pipe 4 of a sewer pipe of permissible bending radius guarantee member 9.
[0031]
The allowable bending radius guarantee member 9 in this example is a so-called flexible pipe having a length of about 1 m formed by winding a metal or plastic strip in a spiral shape, and is usually linear and is into a sewer pipe. However, when the lead-in cable 6 is bent with tension applied to the lead-in cable 6 at the above-mentioned arrangement position, the strips on the inner side of the bend come into contact with each other so that the radius is smaller than a predetermined value. Regulates bending to. Accordingly, the center hole of the allowable bending radius ensuring member 9 of this example through which the lead-in cable 6 is inserted has an optical cable holding portion 9a having a radius Rm equal to or larger than the allowable bending radius of the lead-in cable 6 as shown in FIG. Become.
[0032]
Once the manhole retaining bracket 7 and the public trough retaining bracket 8 are fitted into the sewer pipe opening and inserted into the sewer pipe of the lead-in cable 6 fitted with the allowable bending radius securing member 9 at a predetermined position, As shown in FIG. 13 (a), the allowable bending radius securing member 9 is positioned at the branch portion between the main pipe 3 and the mounting pipe 4 by properly moving the lead-in cable 6 in and out. 14 is inserted, and both ends of an elastic plate 32 (shown by the same reference numerals because of a material of an elastic annular plate described later) having engagement holes 32a at both ends as shown in FIG. As shown in the left side of FIG. 14 (d), the rounded elastic plate (shown by the same reference numeral as the material of the elastic annular plate described later) 32 is further rounded as shown in FIG. 14 (c). Remotely controlled movement with elastically reduced diameter As shown in FIG. 14 (a), it is carried by the tool 31 to an arbitrary position in the mounting tube 4, released at that position, and expanded in diameter by elastic force as shown on the left side of FIG. 14 (d). The lead-in cable 6 is sandwiched between the elastic annular plate 32 and the tube wall of the attachment tube 4.
[0033]
Here, as the remote operation type moving jig 31, for example, an electric type (not shown) that can hold the elastic annular plate 32 in a contracted state by releasing a pin in the engaging holes 32 a at both ends and release the elastic annular plate 32. Although a plier-like hand mounted on a carriage such as an electric model car is used, a remote operation type moving jig 31 having another configuration such as a manual wire operation type can also be used.
[0034]
By repeating such operations, a plurality of elastic annular plates 32 are sequentially arranged from the main pipe 3 side as shown in FIGS. 13 (b) and 13 (c) and retracted along the pipe wall of the mounting pipe 4. After the cable 6 is fixed, the cable core wire of the lead-in cable 6 is shown in FIG. 15 (a) and a part of FIG. The messenger wire 6b separated from 6a is wound around the three messenger wire winding bolts 26 of the public metal clasp 8 in the public mass 2, and these bolts 26 are tightened, so that the public cable 6 The portion adjacent to the retaining bracket 8 (corresponding portion) is fixed to the public retaining bracket 8 and, as shown in FIG. 6b is wound around the three messenger wire winding bolts 26 of the manhole retaining bracket 7 in the manhole 1 and these bolts 26 are tightened, so that the portion of the retracting cable 6 adjacent to the manhole retaining bracket 7 (corresponding To the manhole retaining bracket 7. In FIG. 16, the allowable bending radius ensuring member 9 shown in FIG. 12 is attached to the cable core 6a to protect the cable core 6a.
[0035]
Next, the laying operation procedure of the wiring cable 5 which is the other of the optical cables shown in FIG. 1 will be described. In the laying method of this embodiment, first, the main pipe 3 upstream of the upstream manhole 1 is connected. 17 and 18, as shown in FIG. 17 and FIG. 18, the tip jig 16 to which the wire string 11 is connected is inserted into the main pipe 3 from the manhole 1 on the upstream side, and the wire string 11 is fed out. As shown in FIG. 3, water flows from the water truck 19 to the manhole 1 on the downstream side, and also from the public pipe 2 at the end of the mounting pipe 4 connected to the main pipe 3 between the two manholes 1. 11 is inserted into the main pipe 3, and the wire string 11 is fed out to flow to the manhole 1 on the downstream side by running water.
[0036]
Thereafter, as shown in FIG. 19, the manhole retaining metal fitting 7 is fitted in the same manner as described above at the mouths of the main pipe 3 of the upstream manhole 1 and the downstream manhole 1, respectively. As shown in FIG. 20, a cable drum disposed near the upstream manhole 1 at the rear end of the wire string 11 that has reached the downstream manhole 1 from the upstream manhole 1 to the downstream manhole 1 together with the tip jig 16. The ends of the wiring cable 5 wound around the wire 33 are connected by a connector 34, and the wiring string 11 is pulled from the manhole 1 on the downstream side, whereby the wiring cable 5 is connected to the two manholes 1 on the upstream side and the downstream side. Pass through the main 3 between.
[0037]
Then, the wiring cable 5 is inserted into the cylindrical intermediate support member 10 described above, and the intermediate support member 10 is connected to the manhole 1 on the downstream side from the midway public wall 2 together with the tip jig 16 and the wire string. 11 is connected to the tip of the wire 11, and the intermediate support member 10 is moved along the wiring cable 5 as shown by an arrow E in FIG. By moving to the position of the attachment tube 4 and then further pulling the wire string 11, the wire string 11 moves toward the attachment tube 4 as shown by the solid line in FIG. 21 and FIG. 1A and 1B and FIG. 17, the intermediate support member 10 is bridged over the opening of the mounting pipe 4 on the inner wall upper portion of the main pipe 3, and both end portions of the intermediate support member 10 are The intermediate support part 10 distribution cable 5 which is inserted therein and thus fixing the mounting tube opening of the upper portion of the inner wall of the main pipe 3. In addition, the wiring string 11 from the public mast 2 is attached to the inner wall of the mounting tube 4 together with the retracting cable 6 by the elastic annular plate 32 for fixing the retracting cable 6 to the inner wall of the mounting tube 4 described above. The upper end of the wire 11 is fixed together with the messenger wire 6 b of the lead-in cable 6 to the public metal fitting retaining bracket 8 in the public mast 2.
[0038]
Next, as shown in FIG. 22 (a), the messenger wire 5 b separated from the cable core wire 5 a at one end of the wiring cable 5 passed through the main pipe 3 between the two manholes 1 is placed in one manhole 1. 22 (b), a cylindrical wedge in which the messenger wire 5b is divided into a plurality of parts as shown in FIG. 22 (c) through the wedge hole 28a of the messenger wire fixing member 28 of the manhole retaining bracket 7 as shown in FIG. 34, the wedge 34 is driven into the wedge hole 28a, and the messenger wire 5b is clamped by the wedge 34 and fixed to the messenger wire fixing member 28, so that the wiring cable 5 is retained in the manhole 1 in one manhole 1. The part (corresponding part) adjacent to the metal fitting 7 is fixed to the manhole retaining metal fitting 7, and the end of the messenger wire 5b coming out of the wedge hole 28a Is FIG. 22 (d), to clamp bolted formula messenger wire clips 27 of metal 7 detained manhole bent upwardly as shown in (e).
[0039]
Next, the messenger wire 5b separated from the cable core wire 5a at the other end of the wiring cable 5 is inserted into the wedge hole 28a of the messenger wire fixing member 28 of the manhole retaining member 7 in the other manhole 1 as shown in FIG. In addition, as shown in the right manhole 1 in FIG. 17, a tensioning jig 35 is densely set in the other manhole 1. FIG. 24A is a plan view showing an example of the wire-drawing jig 35, and FIG. 24B is a cross-section of the wire-drawing jig 35 of the example taken along the line FF in FIG. FIG. 24C is a cross-sectional view taken along line GG in FIG. 24A of the tension wire jig 35 of the example, and the tension wire jig 35 of this example is the interior of the manhole 1. A gold wheel 37 is rotatably supported on a frame 36 having a turnbuckle 36a that can be extended after being inserted into the wheel.
[0040]
After that, as shown in FIG. 23A, the messenger wire 5b passed through the wedge hole 28a of the messenger wire fixing member 28 of the manhole retaining bracket 7 is hung around the metal wheel 37 of the tensioning jig 35. The messenger wire 5b is tensioned as shown by an arrow J in FIG. 23 (a) by a normal ratchet type manual wire tensioning machine 38 hung on a mandrel assembled on the manhole 1. The distribution cable 5 passed through the main pipe 3 between the two manholes 1 is stretched near the upper portion of the inner wall of the main pipe 3, and the messenger wire 5b is sandwiched by a plurality of divided cylindrical wedges 34 in this state. Is inserted into the wedge hole 28a as indicated by an arrow K in FIG. 23A, and the messenger wire 5b is clamped by the wedge 34 and fixed to the messenger wire fixing member 28, whereby the wiring cable 5 While to have a tension of cables 5, a portion adjacent to the manhole for anchoring bracket 7 of the other manhole 1 (corresponding part) fixed to the bracket 7 detention manhole.
[0041]
Thereafter, the tensioning jig 35 is removed from the manhole 1, and the messenger wire 5b removed from the tensioning jig 35 is bent upward as shown in FIGS. 23 (a) and 23 (b). The retaining metal fitting 7 is clamped by a bolt-tightened messenger wire clip 27, and the remaining portion ahead of the messenger wire clip 27 is cut and removed. Thereby, the wiring cable 5 can be laid in the main pipe 3 between the two manholes 1.
[0042]
FIG. 25 (a) is a plan view showing another example of the above-described wire-drawing jig 35, and FIG. 25 (b) is a cross-sectional view taken along line H-H of (a) of the wire-drawing jig 35 of the example. FIG. 25C is a cross-sectional view taken along the line II of FIG. 25A of the tension wire jig 35 of the example, and the tension wire jig 35 of this example is the manhole 1. A gold wheel 37 is rotatably supported on an assembling-type frame 36 that can be assembled after being inserted into the inside, and a hydraulic center hole jack 38 is erected on the upper portion of the frame 36, and the center hole jack 38 is connected to a manhole. The manual hydraulic pump 39 is operated from outside 1. The tension wire 35b can also apply tension to the messenger wire 5b.
[0043]
According to the laying method of this embodiment, it fits to the inner peripheral surface of the sewer pipe port provided in the manhole 1 and the public sewer 2 near the building, and engages with the outer part of the sewer pipe port. The upper part of the retaining brackets 7 and 8 with the lower part cut out is passed through the main pipe 3 and the mounting pipe 4 which are sewer pipes extending between the manhole 1 and the public slat 2 and is given tension. By fixing the portions of the retractable cable 6 corresponding to the retaining brackets 7 and 8 respectively, the retractable cable 6 as an optical cable is stretched between the retaining brackets. The separation of the lead-in cable 6 can be minimized, and the lead-in cable 6 is inserted into the thin main pipe 3 and the mounting pipe 4 among the sewer pipes by using complicated and expensive equipment or special materials. Without simply and Shimozuru can be laid without or disturbed in sewer maintenance or interfere with, yet it is possible to protect the pull cable 6 from Shimozuru. Incidentally, for example, in the case of the lead-in cable 6 having a weight of about 18 gw per meter, if a tension of 30 kgf is applied, the slack can be almost eliminated.
[0044]
Further, according to the laying method of this embodiment, when there is a sudden bend at the branching portion of the main pipe 3 and the attachment pipe 4 in the sewer pipe, the portion of the lead-in cable 6 located at the sharp bend Further, since the allowable bending radius ensuring member 9 having the optical cable holding portion having a radius equal to or larger than the allowable bending radius of the drawing cable 6 is disposed, the drawing cable 6 can be protected from a sudden bend.
[0045]
In addition, according to the laying method of this embodiment, the lead-in cable 6 as an optical cable is installed in the main pipe 3 and the mounting pipe 4 which are sewer pipes extending between the public mass 2 and the manhole 1 on the downstream side. When passing, the tip jig 16 having the floating member 13 and the water flow resistance member 14 is connected to the tip of the wire 11, and the tip jig 16 is connected from the public 2 to the manhole 1 on the downstream side by water flow. By passing the string 11 while it is fed out, the wire string 11 is passed between the public cable 2 and the manhole 1 on the downstream side, and one end of the lead-in cable 6 is connected to the cable string 11 to connect the cable string 11. In the sewer pipe, the main cable 3 and the installation pipe 4 are connected between the public housing 2 and the manhole 1 on the downstream side. Easy to pass without using It can be.
[0046]
Furthermore, according to the laying method of this embodiment, the lead-in cable 6 as an optical cable is installed in the main pipe 3 and the mounting pipe 4 which are sewer pipes extending between the public slat 2 and the manhole 1 on the upstream side. When passing, a tip jig 16 having a floating member 13, a water flow resistance member 14 and a magnet or a magnetic body is connected to the tip of the wire string 11, and the tip jig 16 is connected to the upstream side by water flow from the public drain 2. While pulling the connecting string 11 from the manhole 1 to the joining position with the main pipe 3, the pulling device 22 is inserted from the upstream manhole 1 to the joining position to attract the magnet or the magnetic body with a magnetic force. By pulling the tip jig 16 with the retracting device 22 while feeding out the wire 11, the wire 11 is passed between the public mast 2 and the upstream manhole 1, and the wire 1 Since one end of the lead-in cable 6 is connected to the cable 11 and the wire string 11 is pulled, the inside of the main pipe 3 and the mounting pipe 4 that are thin among the sewer pipes between the public tank 2 and the manhole 1 on the upstream side. The lead-in cable 6 can be easily passed without using complicated and expensive devices or special materials.
[0047]
Furthermore, according to the laying method of this embodiment, when the lead-in cable 6 is fixed in the sewer pipe extending between the public mass 2 and the manhole 1, the elastic pipe is elastic in the attachment pipe 4 of the sewer pipe. The annular plate 32 is brought into an arbitrary position by the remote-operated moving jig 31 in a reduced diameter state, released at that position, and enlarged by an elastic force, so that the space between the elastic annular plate 32 and the inner wall of the mounting tube 4 is increased. In the case of the mounting tube 4 bent in the middle, the pull-in cable 6 can be easily inserted into the mounting tube 4 without using complicated and expensive devices or special materials. It can be fixed without obstructing sewer flow or disturbing sewer maintenance.
[0048]
Further, according to the laying method of this embodiment, the lower part that fits to the inner peripheral surface of the sewer pipe port and is engaged with the outer part of the sewer pipe port provided respectively in the sewer pipe port of the two manholes 1 In the upper part of the cut-out metal fitting 7 for manholes, the holding metal fitting 7 of the distribution cable 5 as an optical cable that is passed through a sewer pipe or main pipe 3 extending between the manholes 1 and is given tension By fixing the corresponding parts respectively, the wiring cable 5 is stretched between the clasps 7, so that the separation of the wiring cable 5 from the upper part of the inner wall of the main pipe 3 can be minimized, and even among sewer pipes The wiring cable 5 can be easily inserted into the thin main pipe 3 without using complicated and expensive equipment and special materials, and without disturbing the sewage flow or disturbing the maintenance of the sewage system. It can be laid. Moreover, it is possible to protect the wiring cable 5 from Shimozuru.
[0049]
By the way, for example, in the case of the wiring cable 5 having a weight of about 200 gw per meter, even if tension is applied, a slack of about 100 mm occurs in a 50 m span. The wiring cable 5 passed through the main pipe 3 is supported at an intermediate position by the wiring string 11 passed from the public trunk 2 in the mounting pipe 4 leading to the main pipe 3 which is a sewer pipe between the two manholes 1. Since the intermediate support member 10 is lifted and fixed to the upper part of the inner wall of the main pipe 3 between the two manholes 1 at the position of the mounting pipe 4 from the public mass 2, the span between the two manholes 1 is long, and the tension Even if the wiring cable 5 is somewhat loosened at the intermediate position, the wiring cable 5 can be supported at the intermediate position by the intermediate support member 10 fixed to the upper part of the inner wall of the main pipe 3. The distance between the inner wall of the main pipe 3 can be kept to a minimum.
[0050]
Although the present invention has been described based on the illustrated example, the present invention is not limited to the above-described example. For example, the material and shape of the clasps 7 and 8, the number of the retaining flange portions 24 and the number of messenger wire winding bolts 26. For example, instead of the two retaining flange portions 24 and the retaining flange portions 25, a substantially C-shaped flat plate with a lower part cut out is used, and a messenger wire is attached to the flat plate. A plurality of flanges may be provided that are fixed to the inner peripheral portion of the flat plate and extend in the axial direction so as to fit the inner peripheral surface of the sewer pipe port and position the retaining metal fitting.
[0051]
In the above embodiment, the intermediate support member 10 is slid to the wiring cable 5 passed through the main pipe 3 between the two manholes 1 so that the intermediate support member is located at the position of the mounting pipe 4 from the public grid 2. 10 is arranged, but the intermediate support member is fixed in advance to a predetermined position of the distribution cable 5 passing through the main pipe 3 between the two manholes 1, and the distribution cable 5 is moved, so that the public mass 2 An intermediate support member may be arranged at the position of the mounting pipe 4.
[0052]
Further, a television camera may be mounted on the remote operation type moving jig 31 so that the optical cable can be more appropriately fixed. Further, the allowable bending radius ensuring member 9, the drawing device 22, the tensioning jig 35, etc. Also, it can be changed as needed.
[Brief description of the drawings]
FIG. 1A is a perspective view showing an outline of an optical cable laying state according to an embodiment of an optical cable laying method in a sewer according to the present invention, and FIG. 1B is a branch from a main pipe to a mounting pipe in FIG. Sectional drawing which shows a part, (c) is a perspective view which shows the holding method of the optical cable in a main pipe.
FIG. 2 is a side view illustrating a tip jig used in the laying method of the embodiment.
FIG. 3 is a schematic diagram showing a method for laying a lead-in cable downstream in the laying method of the embodiment.
FIG. 4 is a schematic diagram illustrating a method for laying a lead-in cable upstream in the laying method of the embodiment.
FIG. 5A is a perspective view illustrating a public metal retaining clasp used in the laying method of the embodiment, and FIG. 5B is a front view illustrating the public clasp retaining metal of the example.
6A is a perspective view illustrating a manhole retaining bracket used in the laying method of the embodiment, and FIG. 6B is a front view illustrating the manhole retaining bracket of the example.
FIG. 7 is a perspective view showing an allowable bending radius ensuring member used in the laying method of the embodiment.
FIG. 8A is a partial cross-sectional front view showing an example of the above-described allowable bending radius ensuring member in an assembled state and attached to a retractable cable, and FIG. 8B is a side view of the allowable bending radius ensuring member of the example. FIG. 4C is a cross-sectional view of the allowable bending radius ensuring member of the example along the line AA in FIG. 4D, and FIG. It is sectional drawing which follows the -B line.
9A is a front view showing an inner member constituting the allowable bending radius ensuring member, and FIG. 9B is a side view showing the inner member of the example.
FIG. 10 is a front view of an outer member constituting the allowable bending radius ensuring member.
11A and 11B are perspective views showing how to assemble the allowable bending radius ensuring member and how to attach it to the optical cable.
FIG. 12A is a front view showing another example of the above-mentioned allowable bending radius ensuring member, in a state before being attached to the lead-in cable, and FIG. The front view in the state after mounting | wearing with a lead-in cable, (c) is a front view in the arrangement | positioning state to the branch part of the main pipe of a sewer pipe, and an attachment pipe of the allowable bending-radius ensuring member of the example. .
FIGS. 13A, 13B and 13C are schematic diagrams showing a method for arranging an elastic annular plate in the laying method of the embodiment.
14A is a front view showing an arrangement state of the annular elastic plate, FIGS. 14B and 14C are perspective views showing materials of the annular elastic plate, and FIG. It is explanatory drawing which shows the diameter expansion state of the cyclic | annular elastic board.
FIGS. 15A and 15B are explanatory views showing a state in which the lead-in cable is fixed to the above-described public metal fastener. FIG.
FIG. 16 is an explanatory view showing a fixed state of the lead-in cable to the manhole retaining metal fitting.
FIG. 17 is a perspective view showing a wiring cable laying method among the laying methods of the embodiment.
FIG. 18 is a schematic diagram illustrating a method of passing a wire string in the wiring cable laying method.
FIG. 19 is an explanatory view showing a fitting method of the manhole retaining metal fitting.
FIG. 20 is a schematic diagram showing a wiring cable passing method in the wiring cable laying method.
FIG. 21 is a schematic diagram illustrating a method for installing an intermediate support member in the method for laying a wiring cable.
22 (a), (b), (c), (d), and (e) are explanatory views showing a method of fixing a wiring cable to the manhole retaining bracket.
FIGS. 23A and 23B are explanatory views showing a method of applying tension to the wiring cable with a tensioning jig and a method of fixing the wiring cable to the manhole retaining bracket.
FIG. 24A is a plan view showing an example of the above-mentioned wire-drawing jig, FIG. 24B is a cross-sectional view of the wire-drawing jig of the example, taken along line FF in FIG. (C) is sectional drawing which follows the GG line of (a) of the jig | tool for a tension wire of the example.
FIG. 25A is a plan view showing another example of the above-described wire-drawing jig, and FIG. 25B is a cross-sectional view taken along line HH of FIG. FIG. 4C is a cross-sectional view taken along line II of FIG.
[Explanation of symbols]
1 Manhole
2 public
3 Main
4 Mounting pipe
5 Wiring cable
6 Lead-in cable
7 Manhole retaining bracket
8 Retention bracket for public masu
9 Allowable bending radius guarantee member
10 Intermediate support member
11 Line cord
12 Elastic annular plate
13 Floating member
14 Current resistance member
15 wire
16 Tip jig
17 Twisting back
18 Water surface
19 Water truck
20 wires
21 Magnet
22 Retraction device
23 Fitting part
24 latching flange
25 Retaining flange
26 Messenger Wire Winding Bolt
27 Messenger Wire Clip
28 Messenger wire fixing member
29 Inner member
30 Outer member
31 Remote operation type moving jig
32 Elastic annular plate
33 Cable drum
34 Connecting tools
35 Jig for wire
36 frames
37 gold wheel
38 Manual wire drawing machine
39 Manual hydraulic pump

Claims

When laying an optical cable in the sewer pipe extending between the manhole and the public mass near the building,
Each of the manhole and the public sewage pipe has a fitting part that fits on the inner peripheral surface of the sewage pipe and has a lower part cut out, and a flange that engages with an outer part of the sewage pipe. Provided with retaining clasps,
On top of the anchoring bracket is provided to each of the manhole and public masu sewer pipe opening, by respectively fixing the corresponding portion of the optical cable under tension with passed through the sewer pipe, the said anchoring bracket by the tension A method for laying an optical cable in a sewer pipe, wherein the optical cable is stretched between the retaining metal fittings while being fixed to a sewer pipe port .

At the predetermined position of the optical cable to be positioned at the sharp bend of the sewer pipe, an allowable bending radius ensuring member having an optical cable holding portion having a radius equal to or larger than the allowable bending radius of the optical cable is attached in advance, and the optical cable is pulled in to The method for laying an optical cable in a sewer pipe according to claim 1, wherein an allowable bending radius ensuring member is disposed at the steep bend.

When passing the optical cable through the sewer pipe extending between the public mass and the manhole on the downstream side, the tip jig having a floating member and a water flow resistance member is connected to the tip of the wire string, and the tip By passing the jig from the public mass to the downstream manhole by flowing water, the jig is passed between the public mass and the downstream manhole. The method for laying an optical cable in a sewer pipe according to claim 1 or 2, wherein one end portion of the optical cable is connected to the cable and the wire string is pulled.

When passing the optical cable through the sewer pipe extending between the public and the upstream manhole, a tip jig having a floating member, a water flow resistance member, and a magnet or magnetic material is passed to the tip of the wire string. And connecting the tip jig with the water flow from the upstream manhole to the merging position with the sewer pipe while feeding out the wire string, from the upstream manhole to the merging position, By inserting a retraction device that attracts magnets or magnetic bodies with magnetic force, and pulling out the wire string while pulling the tip jig with the retraction device, the communication between the public mass and the upstream manhole is performed. The method of laying an optical cable in a sewer pipe according to claim 1 or 2, characterized in that a wire string is passed, one end of the optical cable is connected to the wire string, and the wire string is pulled.

When laying an optical cable in a sewer pipe extending between two manholes,
Each of the two manhole sewer pipes has a fitting part that fits on the inner peripheral surface of the sewer pipe and has a notched lower part, and a flange that engages with the outer part of the sewer pipe A retaining bracket is provided,
On top of the anchoring fittings provided respectively to sewer pipe opening of the two manholes, the corresponding portion of the optical cable under tension with passed through the sewer pipe by fixing each said sewerage the anchor bracket by the tension A method for laying an optical cable in a sewer pipe, wherein the optical cable is stretched between the retaining metal fittings while being fixed to a pipe opening .

An intermediate support that supports the optical cable passed through the sewer pipe between the two manholes at an intermediate position with a line string passed from the public maser to the sewer pipe between the public mantle near the building and the sewer pipe between the two manholes. 6. The method of laying an optical cable in a sewer pipe, wherein the member is lifted and fixed to an upper part of an inner wall of the sewer pipe between the two manholes at a position of the sewer pipe from the public mass.

The intermediate support member is disposed at a position of a sewer pipe from the public basin by sliding the intermediate support member with respect to an optical cable passed through a sewer pipe between the two manholes. 6. An optical cable laying method in a sewer pipe according to 6.

The intermediate support member is fixed in advance to a predetermined position of the optical cable passed through the sewer pipe between the two manholes, and the intermediate support member is moved to the position of the sewer pipe from the public mass by moving the optical cable. The method for laying an optical cable in a sewer pipe according to claim 6, wherein the optical cable is laid.