JPH10108331A - Tip part of sub-duct for charging hole conduit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly insert a tip part into a charging hole conduit by fitting a tip cap in which the tip is formed in a spherical surface-like form and the spherical surface radius is nearly equal to the outer radius of a sub-duct to the tip of the sub-duct. SOLUTION: A sub-duct 1 is formed by providing a plastic cover layer 3 in which a plurality of projecting parts 3a are formed in the direction of the length of the peripheral surface of a corrugated pipe 2, and a plastic cover layer 3 located in the vicinity of an end part is removed to expose an internal corrugated pipe 2 and at the same time the projecting parts 3a of the continuous cover layer surface are removed by cutting. A tip cap 11 formed in a tip spherical surface-like form with a wave 11a of engaging with the wave of the pipe 2 being formed in the inner surface on the exposed corrugated pipe 2 is screwed thereinto and fixed thereto, and however, the tip cap 11 is formed of brass, an ABS resin or the like, and the radius 7 of the spherical surface is made nearly equal to the outer radius Rsm of the sub-duct 1. As a result, the tip part is prevented from being caught by the valley part of the corrugated conduit, so that it may be smoothly inserted into the charging hole conduit.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、既に電力ケーブル
等のケーブル類が布設されているいわゆる充孔管路内
に、新たに押込むサブダクトの先端部に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip portion of a sub duct which is newly pushed into a so-called filled pipe in which cables such as a power cable are already laid.

【０００２】近時、電力会社等においては、既に電力ケ
ーブルが布設されているいわゆる充孔管路の隙間にサブ
ダクトを挿入しておき、必要な時に上記サブダクト内に
光ケーブル等の通信、制御用ケーブルを挿入する方法が
採用されようとしている。In recent years, a power company or the like inserts a subduct in a gap of a so-called filled conduit in which a power cable is already laid, and a communication and control cable such as an optical cable is inserted into the subduct when necessary. Is being adopted.

【０００３】上記挿入するサブダクトとしては、例えば
ステンレス等の波付金属パイプの外周上に、ポリエチレ
ン等のプラスチック被覆層を具えており、挿入を容易に
するために、上記プラスチック被覆層の外周表面に長さ
方向に複数の凸条が直線状又はらせん状に形成されたも
のが用いられる。[0003] The subduct to be inserted is provided with a plastic coating layer of polyethylene or the like on the outer periphery of a corrugated metal pipe of stainless steel or the like. One in which a plurality of ridges are formed linearly or spirally in the length direction is used.

【０００４】図２は上記のような構成をもったサブダク
トを充孔管路内へ挿入する際の従来の先端部の一例の側
面図である。サブダクト１の先端を金づち等で潰し、こ
の部分1aに熱収縮性のキャップ21を装着し、加熱収縮さ
せて一体化するのが一般的であった。FIG. 2 is a side view of an example of a conventional distal end portion when a subduct having the above-described configuration is inserted into a filling conduit. In general, the tip of the sub duct 1 is crushed by a metal tool or the like, and a heat-shrinkable cap 21 is attached to this portion 1a, and the heat-shrinkable cap 21 is integrated.

【０００５】[0005]

【発明が解決しようとする課題】上述のようなサブダク
トの先端処理部は端末部防水には効果が認められたが、
挿入の際、サブダクト先端部が波付管路の谷部に引掛か
って挿入困難になるという問題があった。The end treatment section of the sub duct as described above was effective in waterproofing the terminal section.
At the time of insertion, there is a problem that the tip of the subduct is caught by the valley of the corrugated pipe and insertion becomes difficult.

【０００６】[0006]

【課題を解決するための手段】本発明は上述の問題点を
解消し、充孔管路内へサブダクトを挿入する際、先端部
が波付管路の谷部に引掛かることなくスムーズに挿入可
能なサブダクトの先端部を提供するもので、その特徴
は、サブダクトの先端に先端が球面状をなし、かつ球面
半径がサブダクトの外半径にほぼ等しい先端キャップを
取付けたことにある。DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and when a subduct is inserted into a filled pipe, the tip is smoothly inserted without being caught in a valley of a corrugated pipe. The present invention provides a possible sub-duct tip, which is characterized in that the tip of the sub-duct is fitted with a tip cap having a spherical tip and a spherical radius substantially equal to the outer radius of the sub-duct.

【０００７】[0007]

【作用】サブダクト先端部の引掛かり防止のためには、
先端の形状は凹部のない滑らかな凸曲面とする必要があ
る。このような曲面としては例えば球面が考えられる。
サブダクト先端部を球面状としたとき、サブダクト押込
み中にサブダクト先端部が障害物と接触した場合のサブ
ダクト先端部−障害物接線とサブダクト中心軸との交差
角θの違いによる、サブダクト先端部の移動方向の関係
を図３に示す。押込み方向の力Ｆが障害物からの反抗力
Ｈと左（又は右）方向へ動く力Ｌ（又はＲ）へと分れ
る。Ｌ（Ｒ）が大きくなる程左（右）への移動は容易に
なる。[Function] To prevent the sub duct from getting caught,
The shape of the tip must be a smooth convex curved surface without a concave portion. For example, a spherical surface can be considered as such a curved surface.
If the tip of the subduct is spherical, the tip of the subduct moves when the tip of the subduct contacts the obstacle during the pushing of the subduct due to the difference in the intersection angle θ between the tangent to the obstacle and the center axis of the subduct. FIG. 3 shows the relationship between the directions. The force F in the pushing direction is divided into a reaction force H from the obstacle and a force L (or R) moving leftward (or right). The movement to the left (right) becomes easier as L (R) increases.

【０００８】図面において、角度θ＝90°（図３、ロ）
では先端部は左右のいずれにも移動せず、θ＞90°（図
３、イ）以上であればサブダクト先端部は左方向に、θ
＞90°（図３、ハ）では先端部は右方向に移動すること
がわかる。従って、図３の障害物を波付管路の谷部に置
換え、同図の左方向を山部、右方向を谷部と考えると、
角度θ＞90°であればサブダクトの先端部は山部の方向
へ移動し、谷部での引掛かりは発生しないことがわか
る。In the drawing, the angle θ = 90 ° (FIG. 3, b)
In this case, the tip does not move to the left or right, and if θ> 90 ° or more (A in FIG. 3), the tip of the sub duct moves to the left, θ
At> 90 ° (FIG. 3, C), the tip moves to the right. Therefore, if the obstacle in FIG. 3 is replaced with a valley of a corrugated pipe, and the left direction in the figure is considered as a mountain and the right direction is considered as a valley,
If the angle θ> 90 °, the tip of the sub duct moves in the direction of the peak, and it can be seen that no catch occurs in the valley.

【０００９】サブダクト先端部と波付管路内面との接触
状況は実際には図４のようになる。同図においてはサブ
ダクト中心軸と管路中心軸との交差角φが一定の場合、
即ちφａ＝φｂ＝φｃの場合には、球面半径ｒが大きく
なる程（ｒａ＞ｒｂ＞ｒｃ）、角度θも大となり（θａ
＞θｂ＞θｃ）、波付管路の谷部への引掛かりが発生し
にくくなることがわかる。反面、先端部の球面半径が管
路のクリアランスを超えると挿通不能となる。又先端部
外径がネックとなって挿通不能となるのは本来の目的に
反する。従って、先端キャップの球面半径は、可能な限
り大きくすることと、先端部が挿通ネックとならないこ
との２つを満足する必要があることがわかる。以上のこ
とから、先端キャップの球面半径ｒはサブダクトの外半
径Ｒｓｍａｘとほぼ等しくするのが適当である。The contact state between the tip of the subduct and the inner surface of the corrugated pipeline is actually as shown in FIG. In the figure, when the intersection angle φ between the subduct center axis and the pipe center axis is constant,
That is, when φa = φb = φc, as the spherical radius r increases (ra>rb> rc), the angle θ also increases (θa
>Θb> θc), it can be seen that it is less likely to be caught in the valley of the corrugated pipe. On the other hand, if the spherical radius of the distal end exceeds the clearance of the conduit, insertion becomes impossible. Further, the fact that the outer diameter of the distal end portion becomes a neck and cannot be inserted is contrary to the original purpose. Therefore, it can be seen that the spherical radius of the tip cap needs to satisfy two requirements, that is, as large as possible and that the tip does not become an insertion neck. From the above, it is appropriate that the spherical radius r of the tip cap be substantially equal to the outer radius Rsmax of the subduct.

【００１０】[0010]

【発明の実施の形態】図１は本発明の充孔管用サブダク
トの先端部の具体例の下半分縦断面をあらわした側面図
である。図面において、１はサブダクトで、例えばステ
ンレスの波付パイプ２の外周上に、外周表面に長さ方向
に複数の凸条3aを形成したポリエチレン等のプラスチッ
ク被覆層３を設けて構成されている。上記サブダクト１
の端部付近のプラスチック被覆層３を除去して内部の波
付パイプ２を露出するとともに、これに続くプラスチッ
ク被覆層表面の凸条3aを削り取って表面を平滑3bにす
る。FIG. 1 is a side view showing a lower half vertical section of a specific example of a tip portion of a subduct for a filled pipe according to the present invention. In the drawings, reference numeral 1 denotes a subduct, which is formed by, for example, providing a plastic coating layer 3 of polyethylene or the like having a plurality of ridges 3a formed in a length direction on an outer peripheral surface of a corrugated pipe 2 of stainless steel. The above sub duct 1
The plastic coating layer 3 near the end is removed to expose the internal corrugated pipe 2, and the ridges 3a on the surface of the plastic coating layer following this are scraped to make the surface smooth 3b.

【００１１】上記露出した波付パイプ２上には、内面に
パイプ２の波に係合する波11a を形成した先端球面状の
先端キャップ11をねじ込むことによって取付ける。この
先端キャップ11は真ちゅう、アルミニウム、ＡＢＳ樹脂
等で形成されており、その球面半径ｒはサブダクト１の
外半径Ｒｓｍａｘにほぼ等しい。なお、12は先端キャッ
プ11に形成したひき紐取付け用のプーリング用穴であ
る。上記のように、波付金属パイプ２上に取付けた先端
キャップ11端部と凸条3aを削り取ったプラスチック被覆
層3b端部の間には、水密コンパウンド13を充填し、さら
に先端キャップ11端部から上記被覆層3b間にわたって、
例えば自己融着テープ層14及び保護テープ層15を施して
端末部防水処理部を形成する。A tip cap 11 having a spherical tip is formed on the exposed corrugated pipe 2 and has a wave 11a on its inner surface which engages with the wave of the pipe 2. The tip cap 11 is made of brass, aluminum, ABS resin or the like, and its spherical radius r is substantially equal to the outer radius Rsmax of the subduct 1. Reference numeral 12 denotes a pulling hole formed in the tip cap 11 for attaching a drawstring. As described above, the watertight compound 13 is filled between the end of the tip cap 11 attached on the corrugated metal pipe 2 and the end of the plastic coating layer 3b from which the ridges 3a have been removed. From between the coating layer 3b to
For example, a self-sealing tape layer 14 and a protective tape layer 15 are applied to form a terminal waterproofing section.

【００１２】[0012]

【実験例】図５は実験例の説明図である。図のように配
設された波付プラスチックパイプＡ（内径 156mm、外径
195mm、波付ピッチ38mm）内に既に電力ケーブルＢ（66
00Ｖ、ＣＶＴ３×250mm²、外径78mm）が布設されてい
る。このような状態において、図２に示す従来の先端キ
ャップと本発明の先端キャップ（材質：真ちゅう）を、
それぞれ外径が38mmφのサブダクトに取付け、図の矢印
ａの方向から上記波付パイプＡ内に押込み、挿通性能を
比較した。結果は、従来の先端キャップを取付けたサブ
ダクトは入口から75ｍの山の頂上を過ぎたあたりでスト
ップし、本発明のサブダクトは全長挿通可能であること
が確認された。EXPERIMENTAL EXAMPLE FIG. 5 is an explanatory view of an experimental example. Corrugated plastic pipe A (inner diameter 156mm, outer diameter as shown)
Power cable B (66mm) within 195mm, corrugated pitch 38mm
00V, CVT 3 × 250 mm ² , outer diameter 78 mm). In such a state, the conventional tip cap shown in FIG. 2 and the tip cap of the present invention (material: brass) are
Each was attached to a sub-duct having an outer diameter of 38 mmφ, pushed into the corrugated pipe A from the direction of arrow a in the figure, and the penetration performance was compared. As a result, it was confirmed that the conventional subduct with the tip cap was stopped around the top of the mountain 75 m from the entrance, and that the subduct of the present invention could be fully inserted.

【００１３】[0013]

【発明の効果】以上説明したように、本発明の充孔管路
用サブダクトの先端部によれば、サブダクトの先端に取
付けるキャップを球面状となし、かつ球面半径をサブダ
クトの外半径にほぼ等しくすることにより、先端部が波
付管路の谷部に引掛かることを防ぎ、スムーズに充孔管
路内に挿入することが可能となる。As described above, according to the tip of the subduct for a filled conduit of the present invention, the cap attached to the tip of the subduct has a spherical shape, and the spherical radius is substantially equal to the outer radius of the subduct. By doing so, it is possible to prevent the distal end portion from being caught in the valley portion of the corrugated pipe, and to smoothly insert the pipe into the filled pipe.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の充孔管路用サブダクトの先端部の具体
例の下半分縦断面をあらわした側面図である。FIG. 1 is a side view showing a lower half longitudinal section of a specific example of a distal end portion of a subduct for a filled pipeline of the present invention.

【図２】従来のサブダクト先端部の一例の側面図であ
る。FIG. 2 is a side view of an example of a conventional sub duct tip.

【図３】（イ）〜（ハ）はいずれもサブダクト先端部が
障害物と接触した場合のサブダクト先端部の移動方向の
説明図である。FIGS. 3A to 3C are explanatory diagrams of the moving direction of the subduct tip when the tip of the subduct contacts an obstacle.

【図４】サブダクト先端部と波付管路内面との接触状況
の説明図である。FIG. 4 is an explanatory diagram of a state of contact between a tip end of a subduct and an inner surface of a corrugated pipe.

【図５】実験例の説明図である。FIG. 5 is an explanatory diagram of an experimental example.

【符号の説明】[Explanation of symbols]

１ サブダクト ２ 波付金属パイプ ３ プラスチック被覆層 11 先端キャップ 12 プーリング用穴 13 水密コンパウンド 14 自己融着テープ層 15 保護テープ層 DESCRIPTION OF SYMBOLS 1 Subduct 2 Corrugated metal pipe 3 Plastic coating layer 11 Tip cap 12 Pooling hole 13 Watertight compound 14 Self-fusing tape layer 15 Protective tape layer

───────────────────────────────────────────────────── フロントページの続き (72)発明者 永野 浩文 福岡市中央区渡辺通２丁目１番82号 九州 電力株式会社内 (72)発明者 大宝 俊弘 福岡市南区那の川１丁目23番35号 株式会 社九電工内 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hirofumi Nagano 2-182 Watanabe-dori, Chuo-ku, Fukuoka City Inside Kyushu Electric Power Co., Inc. (72) Inventor Toshihiro 1-23-35 Nanokawa, Minami-ku, Fukuoka Shares Company Kyuden

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 既にケーブルが布設されている充孔管路
内に押込むサブダクトの先端部であって、上記サブダク
トの先端に、先端が球面状をなし、かつ球面半径がサブ
ダクトの外半径にほぼ等しい先端キャップを取付けたこ
とを特徴とする充孔管路用サブダクトの先端部。1. A tip portion of a subduct which is pushed into a filled conduit in which a cable is already laid, wherein the tip of the subduct has a spherical shape, and a spherical radius corresponds to an outer radius of the subduct. A distal end portion of a subduct for a filled conduit, wherein a substantially equal distal end cap is mounted.