JP3689032B2

JP3689032B2 - Fixing ring for tube end anticorrosion core, fixing structure using the same, and fixing method

Info

Publication number: JP3689032B2
Application number: JP2001319335A
Authority: JP
Inventors: 祥一平田; 吉彦山本; 大造渡辺; 仁猪尾
Original assignee: Kurimoto Ltd; Togawa Rubber Co Ltd
Current assignee: Kurimoto Ltd; Togawa Rubber Co Ltd
Priority date: 2001-10-17
Filing date: 2001-10-17
Publication date: 2005-08-31
Anticipated expiration: 2021-10-17
Also published as: JP2003120892A

Description

【０００１】
【発明の属する技術分野】
この発明は、パイプラインを構成する上で必要となる乱尺管（切管）に供するもので、特に水道などに用いられる金属管切管端面の防食コアの固定リング及びその固定構造並びに固定方法に関するものである。
【０００２】
【従来の技術】
従来、ダクタイル鋳鉄管を地中に埋設して管路を布設する際、管全体に亘って塗装やライニングによって防食を行い、図１３に示すように、先行する管１の受口１ａに後続管２の挿し口２ａを挿入して継合されるのが一般的である。このとき、同図に示すように、耐震性を付与したＮＳ形継手にあっては、受口１ａ内面にロックリング３を設け、同図鎖線のごとく、このロックリング３を突起４が乗り越えて挿し口２ａを挿入する。図中、５はパッキング、６はライニングである。
【０００３】
この管路の布設において、常に定寸法な管による継合だけでは留まらず、工事現場で所定の長さになるように管２を切断して継合しなければならない場合がある。このように途中で管２を切断すると、切断面となる管端面は塗装が剥離して地肌が露出するために、防食機能が損なわれ赤水などの発生を招くことになる。そのため、一般には、切管後の端面には防食塗装を再度塗布して防食を行うことが行われている。しかし、切管後の端面に防食塗料を塗布して再度防食を行う場合、寒冷時においては乾燥に時間がかかり、また、切替工事などの流水が完全に止まらない個所では、塗布しにくい等の作業しづらい、といった問題がある。
【０００４】
このため、切管後の端面に防食用塗料を塗布する以外の方法として、図１４に示すように、防食コア７を使用して露出した部分をシールする方法がある。この防食コア７はゴムなどの弾性体で構成されているので、その弾性によって保持されるが、より確実に固定する方法として特開平７−１３９６８６号公報等に示すように、周方向一つ割の開き勝手の固定リング１０を溝８に嵌めて防食コア７を内面から拡径力によって固定させるものがある。
【０００５】
しかし、この固定リング１０は開き勝手の拡径力で防食コア７を固定しているため、長期使用すると、固定リング１０の材料の経年劣化などにより拡径力の減衰が生じ、防食機能を維持し続けるには限度があって、信頼性が低いという問題がある。
【０００６】
また、管を埋設する際には、土かぶりによる外圧、路面荷重による土圧、内圧などの使用条件、地形、地質、交通量等から管布設方法として適切に選定される開削工法、推進工法、シールド工法等の布設工法、耐用年数等を考慮して、技術面や経済面を検討して使用管種を選択することになる。
【０００７】
このとき、選択される管種によって、例えば、１種管、３種管のように同じ呼び径であっても、管厚差及び製造時の管厚公差により管の内周長が変わることになる。この管内周長が変っても、同じ固定リング１０で対応できることが好ましい。
【０００８】
このため、本出願人は、特開２００１−１４１１７５号公報で示され、図１１に示す縮径防止機能付き固定リング１０を提案した。この固定リング１０は、一つ割りの一端１１に首部１１ａが形成され、同図（ｂ）に示すように、その首部１１ａを他端１３の長孔１４に挿入係止するとともに、他端１３の係止片１５を一端１１の係止孔１２に挿通して円環状にし、その円環状固定リング１０を防食コア７の内面に装填して拡張して圧接した後、係止片１５を折り返して一端１１に係止し、その係止により縮径を防止したものである（図４参照）。
【０００９】
【発明が解決しようとする課題】
この図１１の固定リング１０においては、コア７内面周長の変化に対して、その調整幅は、首部１１ａが長孔１４内を移動し得る範囲に限定される。このとき、仮に、図１２（ａ）に示すように、長孔１４と係止片１５の切欠を連続したものとして、首部１１ａの移動度を大きくしてある程度のコア内面周長に対応することを可能としても、係止片１５を折り曲げることができる範囲内でしか調整幅がなく、特に、ダクタイル鋳鉄管において内面をモルタルライニングする場合には、管厚の大小（管外径が同じ時、管厚が厚いと内径小、管厚が薄いと内径大）の幅が大きく、その管内周長の変化を吸収することができない場合がある。また、この場合、同図（ｂ）に示すように、拡径工具（図６の符号２０参照）先端の開き幅Ｌが大きくなりすぎて、拡径治具に大きな調整機能が必要となる上、固定リング１０を拡径させた場合に拡径用孔１６、１６間の固定リング部分が反り上がってしまい、固定リング１０による固定力が不完全なものとなって防食コア７の固定力が低下して、防食コアが脱落するという問題がある。
【００１０】
この発明は、管内周長の変化に対応し易くすることを課題とする。
【００１１】
【課題を解決するための手段】
上記課題を解決するために、この発明は、上述の固定リングの一つ割りの両端間に縮径防止機能を付与したものにおいても、その縮径防止機能の対応幅を広くして、管内周長の変化に対応し得るようにしたのである。
【００１２】
【発明の実施の形態】
この発明の固定リングに係る実施形態としては、管端防食コアの管端部内面に挿入された円筒部内面全周に亘って設けられて、防食コアをその前記円筒部を管端部内面に圧接して固定する固定リングにおいて、周方向一つ割りで、その一端に他端の係止片が挿し通されて、その係止片は折り返される構成を採用し得る。この構成では、係止片の折り返しにより、その折曲部と挿し通し孔の縁が係止して固定リングの縮径防止機能が果たされる。
【００１３】
この構成において、固定リングの一端は幅狭となった首部が形成され、その首部を介して他端の固定リングの周方向に長い長孔にその一端が摺動自在に挿し通され、その一端の幅は前記長孔の幅より広くて抜け止めされる構成とすれば、その一端の抜け止め状態の前記長孔内の移動によって、固定リングの拡縮径が円滑に調整される。すなわち、その移動がガイドとなる。
【００１４】
さらに、上記首部を複数個形成すれば、その首部を適宜に選択することにより、管内周長の変化に対応し易くなる。また、拡径用孔間をほぼ一定の間隔として拡径することが可能となり（リングを掛け合わせたときのリング周長を自在に変えることができ）、固定リングの拡径が反り上がりがなく完全なものとなる。
【００１５】
このように構成される固定リングは、管端防食コアの管端部内面に挿入された円筒部内面全周に亘って嵌められ、その両端は重ねられて、一端は所要の首部を介して他端の長孔に挿し通されて抜け止めされ、他端の係止片は一端の孔に挿し通されて拡径の後、折り返されて取付けられる。このとき、長孔に係止する首部より先端の首部は切除するとよく、その切断は一端を他端に挿し通す前が好ましいが、挿し通し後でもよい。
【００１６】
【実施例】
図５はこの発明の縮径防止機能を兼ね備えた固定リングを示す正面図であり、この固定リング１０は従来から用いられている一つ割りの形態で、Ａ側の一端（先端）１１は所要数の首部１１ａが長さ方向に形成されてその内側に孔１２を有し、Ｂ側の他端１３には先端１１の首部１１ａと掛け合わされる長孔１４と前記孔１２に差し込む係止片１５が形成されている。１６はスナップリングプライヤー２０などを用いて固定リング１０を拡張させて管端防食コア７に嵌め込むために設けた拡径用孔であり、他端１３側の孔１６は長孔１４の丸形一端で兼用でき、これらの孔１６はなくても取付けに支障はない。固定リング１０の材質はばね性のステンレス材が望ましいが、ばね性がない材料などと特に限定しない。
【００１７】
図４、図６はこの固定リング１０の取付け手順を示す斜視図であり、防食コア７はごく一般的に使用されているもので、図１、図２に示すように、内面に固定リング１０を嵌め込む突起（突条）９が設けられている。この突起９の数は任意であり、その上面は、固定リング１０側から防食コア７内面に向って下り勾配のテーパ面９ａとなっており、このテーパ面９ａによって、固定リング１０の嵌め込みをスムースに行うことができるとともに、水等の流れもスムースに案内される。このとき、この突起９の高さ及びテーパ面９ａの傾斜角度は、固定リング１０の位置決め（抜け止め）及び嵌め込みをスムースにし得るかぎりにおいて任意であるが、高さは、流通性から固定リング１０の厚みと同一か、又は低くすることが好ましいが、外れることも考慮すれば、固定リング１０の厚みより高くてもよい。なお、この突起９を設けたことにより、コア７内面の厚みを全体的に薄くすることができ、その結果、コア７に柔軟性が出ることとなり、コア７の装着が容易となる。
【００１８】
この固定リング１０による防食コア７の固定は、まず、図６（ａ）のごとく固定リング１０を円環状にし、つぎに、同図（ｂ）のごとく、先端１１を長孔１４に掛け合わせた後、孔１２に係止片１５を差し込んで、このリング１０の外径をコア７の内径より小さくし、図４の鎖線から実線のごとく、固定リング１０をコア７内面の突起９間に納め、スナップリングプライヤー２０や万力などの簡単な治具を使用してコア７内面で固定リング１０を拡張させ（図６（ｂ）参照）、孔１２からのぞいている係止片１５を同図及び図６（ｃ）のごとく折り曲げ、固定リング１０が円周方向に縮まないように固定する。
【００１９】
このとき、同一外径の管Ｐであっても、管厚、ライニング層によって管内周長が異なるため、その内周長に応じて長孔１４に掛け合わす先端（首部）１１ａを適宜に選択する。図７はその一例を示すもので、管内周長が長い（管内径大）場合には、最先端の首部１１ａと他端１３に設けた両拡径用孔（治具用孔）１６とでリング１０の拡径を行い（ｄ）、管内周長が短く（管内径小）なるに連れて、内側の首部１１ａを選択することで、拡径用孔１６、１６間をほぼ一定Ｌ₁に保つことが可能となるため、リング１０に最適な拡径力を与えることが可能となる。
【００２０】
この手法によって固定リング１０を防食コア７内面に固定（拡径）するにあたり、管端に防食コア７を嵌め込んだ状態でコア７内面の直径を測定し、この数値から管内周長を算出して、その長さに最適となる首部１１ａを選定し、余分となる首部１１ａを切断した後に固定リング１０をその両端１１，１３を掛け合わせて円環状とし、又は円環状とした後に余分な首部１１ａを切断し、その後，防食コア７に嵌め、拡径して取り付けを行う。このとき、現地での施工性を考慮して、予め直径に対する管内周長を算出し、その数値と選定する首部１１ａについて早見表等を作成しておけば、直径を測定するだけで選定する首部１１ａが分かるため、取り付けの際に選定ミスが発生することが少なくなる。例えば、周長に合う番号を各首部１１ａに付けておくとよい。
【００２１】
このようにして固定リング１０をコア７内面に装着することにより、水流によるコア７の脱落を防止することに加えて、複数個設けた首部１１ａを管内周長に応じて適宜に選択して、拡径用孔１６、１６間をほぼ一定にして長孔１４に掛け合わせることで、固定リング１０に最適な拡径力を与えることが可能となるとともに、長孔１４の長さ分、及び先端１１に設けた首部１１ａの数だけ管内径の円周寸法公差を吸収できて、リング１０をコア７に円滑に固定でき、かつ、係止片１５により縮径を長期にわたり防止してコア７を管端に強固に固定して赤水を防止する。なお、以上の実施例では首部１１ａの数を４つとして説明したが、数に拘りはなく管径によって数を増減できることは言うまでもない。
【００２２】
図８の実施例は、肉抜き１７を形成したものであり、この肉抜き１７の形状は、長孔（同図（ａ））、円孔（同図（ｂ））、角孔などと任意である。この肉抜き１７は、固定リング１０を曲げ易くするためであり、このため、その程度において、数、位置を設定する。曲げ易くなれば、内周長が短くなると（小口径管の場合）、有利である。
【００２３】
なお、拡径用孔１６は、図９に示すように、その周囲に立ち上がり壁１６ａを形成すると、スナップリングプライヤー２０等の治具によるリング１０の拡縮径時、その壁１６ａが補強となって治具２０がその孔１６から外れにくく、その作用がスムースとなる。その壁１６ａは、孔１６の形成時に切り起こしによって形成すればよく、同図（ｂ）のように傾斜壁とすれば、治具２０の先端部が入り易い等の利点がある。
【００２４】
また、拡径用孔１６に代えて係止突起とすることもできる。このため、「拡径用孔１６」には「係止突起」も含む。例えば、図１０（ａ）乃至（ｃ）に示すように、弧状に膨出させた突起１８を採用することができ、この突起１８は、同図（ｄ）のごとく、治具２０と係止する。このとき、同図（ｃ）のように、突起１８に治具２０の係止孔１８ａを形成するとよい。
【００２５】
さらに、係止片１５をその全長に亘って高周波などにより焼きなましすれば、係止片１５が折り曲げ易くなって、その作業性が向上するとともに、しっかり折り曲げることができてその係止状態が安定する。この焼きなましは、固定リング１０が弾性材の場合に有効である。
【００２６】
この発明に係る固定リング１０は図１４のように溝８に嵌める態様も採用し得ることは言うまでもなく、また、ＮＳ形継手に限らず、防食コア７を嵌着固定する管端の全てに適用し得ることは勿論である。
【００２７】
【発明の効果】
この発明は、以上のように固定リングに縮径防止機能を付与したので、固定リングの拡径力の経年劣化も抑制され、このため、防水コアの管端への十分な密着度も長年に亘って維持され、長期間にわたり、赤水を防止することができる。
【００２８】
また、首部を複数にしたので、管内周長の変化に対応し易いうえに、係止片を長くする必要もなく、このため、管内面に突出する部分が少ない。
【図面の簡単な説明】
【図１】一実施例の要部斜視図
【図２】（ａ）は図１のＡ−Ａ線断面図、（ｂ）は同Ｂ−Ｂ線断面図
【図３】同実施例の防食コアの取付説明図
【図４】同実施例の固定リングの取付け作用図
【図５】同固定リングの一実施例の平面図
【図６】同固定リングの取付作用図
【図７】同固定リングの取付作用図
【図８】他の固定リングの各実施例の平面図
【図９】他の各実施例の要部断面図
【図１０】他の実施例の要部斜視図又は断面図
【図１１】従来の固定リングを示し、（ａ）は平面図、（ｂ）は作用図
【図１２】同従来例の作用図
【図１３】管継手部の要部断面図
【図１４】管挿し口の要部拡大断面図
【符号の説明】
１、２管
１ａ受口
２ａ挿し口
７防食コア
９固定リング位置決め突起
１０防食コア用固定リング
１１固定リングの一つ割りの一端（先端）
１１ａ一端首部
１２係止片挿通用孔
１３固定リングの一つ割りの他端
１４長孔
１５係止片
１６拡径用孔
１８係止突起
２０スナップリングプライヤー（拡径治具）[0001]
BACKGROUND OF THE INVENTION
The present invention is used for a turbulent pipe (cut pipe) necessary for constructing a pipeline, and in particular, a fixing ring of a corrosion prevention core on a metal pipe cut pipe end face used for water supply, a fixing structure thereof, and a fixing method It is about.
[0002]
[Prior art]
Conventionally, when a ductile cast iron pipe is buried in the ground and a pipe line is laid, the entire pipe is protected against corrosion by painting or lining, and as shown in FIG. It is common to insert and insert two insertion openings 2a. At this time, as shown in the figure, in the NS type joint provided with earthquake resistance, the lock ring 3 is provided on the inner surface of the receiving port 1a, and the projection 4 gets over the lock ring 3 as shown by the chain line in the figure. Insert the insertion slot 2a. In the figure, 5 is a packing and 6 is a lining.
[0003]
In the laying of this pipe line, there is a case where the pipe 2 is not always connected only by a fixed-size pipe, but the pipe 2 must be cut and joined so as to have a predetermined length at the construction site. When the tube 2 is cut in this way, the coating is peeled off and the background is exposed on the tube end surface that becomes the cut surface, so that the anticorrosion function is impaired and red water or the like is generated. Therefore, in general, the anticorrosion coating is applied again to the end face after the cut tube to perform the anticorrosion. However, when anticorrosion paint is applied to the end face after the cut tube and the anticorrosion is applied again, it takes time to dry in cold weather, and it is difficult to apply in places where running water does not stop completely, such as switching work. There is a problem that it is difficult to work.
[0004]
For this reason, as a method other than applying the anticorrosion paint to the end face after the cut tube, there is a method of sealing the exposed portion using the anticorrosion core 7, as shown in FIG. Since this anticorrosion core 7 is made of an elastic body such as rubber, it is held by its elasticity. However, as shown in Japanese Patent Laid-Open No. 7-139686, etc. There is a type of fixing the anti-corrosion core 7 from the inner surface by a diameter expansion force by fitting the fixing ring 10 of the open side to the groove 8.
[0005]
However, since the fixing ring 10 fixes the anticorrosion core 7 with a large opening force, the expansion force is attenuated due to deterioration of the material of the fixing ring 10 over time, and the anticorrosion function is maintained. There is a problem that there is a limit to continuing to do so and the reliability is low.
[0006]
In addition, when burying pipes, the excavation method, propulsion method, which is appropriately selected as the pipe laying method based on the use conditions such as external pressure due to earth covering, earth pressure due to road load, internal pressure, topography, geology, traffic volume, Considering the laying method such as the shield method, the service life, etc., the type of pipe to be used will be selected by considering the technical and economic aspects.
[0007]
At this time, depending on the selected pipe type, the inner peripheral length of the pipe varies depending on the pipe thickness difference and the pipe thickness tolerance at the time of manufacture even if the same nominal diameter is used, for example, the first and third pipes. Become. It is preferable that the same fixing ring 10 can cope with the change in the inner circumferential length of the pipe.
[0008]
For this reason, the present applicant has proposed a fixing ring 10 with a diameter reduction preventing function shown in Japanese Patent Laid-Open No. 2001-141175 and shown in FIG. The fixing ring 10 has a neck portion 11a formed at one end 11 divided into one portion, and as shown in FIG. 5B, the neck portion 11a is inserted and locked into the long hole 14 at the other end 13 and the other end 13 is inserted. The locking piece 15 is inserted into the locking hole 12 of the one end 11 to form an annular shape, the annular fixing ring 10 is loaded on the inner surface of the anticorrosion core 7 and expanded and pressed, and then the locking piece 15 is folded back. The one end 11 is locked and the diameter is prevented by the locking (see FIG. 4).
[0009]
[Problems to be solved by the invention]
In the fixing ring 10 shown in FIG. 11, the adjustment width is limited to a range in which the neck portion 11 a can move in the long hole 14 with respect to the change in the inner circumferential length of the core 7. At this time, as shown in FIG. 12A, assuming that the notch of the long hole 14 and the locking piece 15 is continuous, the mobility of the neck portion 11a is increased to correspond to a certain length of the inner circumference of the core. However, the adjustment width is only within the range in which the locking piece 15 can be bent. Especially, when the inner surface is mortar-lined in a ductile cast iron pipe, the pipe thickness is large (when the pipe outer diameter is the same, If the tube thickness is thick, the inner diameter is small, and if the tube thickness is thin, the inner diameter is large. In some cases, changes in the inner peripheral length of the tube cannot be absorbed. Further, in this case, as shown in FIG. 6B, the opening width L at the tip of the diameter expansion tool (see reference numeral 20 in FIG. 6) becomes too large, and a large adjustment function is required for the diameter expansion jig. When the diameter of the fixing ring 10 is increased, the fixing ring portion between the diameter expanding holes 16 and 16 warps, and the fixing force by the fixing ring 10 becomes incomplete, and the fixing force of the anticorrosion core 7 is increased. There exists a problem that it falls and an anticorrosion core falls off.
[0010]
This invention makes it a subject to make it easy to respond to the change of pipe inner periphery length.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a diameter reduction preventing function between both ends of the above-mentioned fixing ring, and the corresponding width of the diameter reducing prevention function is widened so that the inner diameter of the pipe is increased. It was able to respond to changes in length.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
As an embodiment according to the fixing ring of the present invention, the anticorrosion core is provided on the inner surface of the tube end portion, and is provided over the entire inner surface of the cylindrical portion inserted into the inner surface of the tube end portion of the tube end anticorrosion core. In the fixing ring that is pressed and fixed, it is possible to adopt a configuration in which the locking piece at the other end is inserted into one end and the locking piece is folded back in one circumferential direction. In this configuration, when the locking piece is folded back, the bent portion and the edge of the through hole are locked, and the function of preventing the diameter reduction of the fixing ring is achieved.
[0013]
In this configuration, a narrow neck portion is formed at one end of the fixing ring, and one end of the fixing ring is slidably inserted into a long hole in the circumferential direction of the fixing ring at the other end through the neck portion. If the width of the fixing ring is wider than that of the long hole and is prevented from coming off, the expansion / contraction diameter of the fixing ring is smoothly adjusted by the movement of one end of the fixing hole in the long hole. That is, the movement becomes a guide.
[0014]
Furthermore, if a plurality of the neck portions are formed, it becomes easy to cope with a change in the inner peripheral length of the pipe by appropriately selecting the neck portions. In addition, it is possible to expand the diameter between the diameter expansion holes with a substantially constant spacing (the ring circumference when the rings are combined can be changed freely), and the diameter of the fixed ring does not warp It will be complete.
[0015]
The fixing ring configured as described above is fitted over the entire inner surface of the cylindrical portion inserted into the inner surface of the tube end portion of the tube end anticorrosion core, its both ends are overlapped, and one end is connected to the other via a required neck portion. It is inserted through the long hole at the end and is prevented from coming off, and the locking piece at the other end is inserted through the hole at one end, and after being expanded in diameter, is folded and attached. At this time, the neck portion at the tip of the neck portion locked in the long hole may be excised, and the cutting is preferably performed before one end is inserted into the other end, but may be after the insertion.
[0016]
【Example】
FIG. 5 is a front view showing a fixing ring having a function of preventing diameter reduction of the present invention. This fixing ring 10 is a conventional one-piece configuration, and one end (tip) 11 on the A side is required. A plurality of neck portions 11 a are formed in the length direction and have a hole 12 on the inside thereof. A long hole 14 that is engaged with the neck portion 11 a of the tip 11 and a locking piece that is inserted into the hole 12 are formed on the other end 13 on the B side. 15 is formed. Reference numeral 16 denotes a diameter expansion hole provided for expanding the fixing ring 10 using a snap ring pliers 20 or the like to be fitted into the pipe end anticorrosion core 7, and the hole 16 on the other end 13 side is a round shape of the long hole 14. It can be used at one end, and even if these holes 16 are not provided, there is no hindrance to the mounting. The material of the fixing ring 10 is preferably a springy stainless material, but is not particularly limited to a material having no springiness.
[0017]
FIGS. 4 and 6 are perspective views showing the mounting procedure of the fixing ring 10, and the anticorrosion core 7 is generally used. As shown in FIGS. 1 and 2, the fixing ring 10 is provided on the inner surface. A protrusion (protrusion) 9 is provided for fitting. The number of the projections 9 is arbitrary, and the upper surface thereof is a tapered surface 9a having a downward slope from the fixing ring 10 side toward the inner surface of the anticorrosion core 7, and the fitting of the fixing ring 10 is smoothly performed by the tapered surface 9a. The flow of water or the like is also smoothly guided. At this time, the height of the protrusion 9 and the inclination angle of the taper surface 9a are arbitrary as long as the positioning (removal prevention) and fitting of the fixing ring 10 can be made smooth. It is preferable that the thickness is equal to or lower than the thickness of the fixing ring 10, but it may be higher than the thickness of the fixing ring 10 in consideration of detachment. In addition, by providing this protrusion 9, the thickness of the inner surface of the core 7 can be reduced as a whole. As a result, the core 7 becomes flexible and the core 7 can be easily attached.
[0018]
The anti-corrosion core 7 is fixed by the fixing ring 10 as follows. First, the fixing ring 10 is formed into an annular shape as shown in FIG. 6 (a), and then the tip 11 is hung on the long hole 14 as shown in FIG. 6 (b). Thereafter, the locking piece 15 is inserted into the hole 12 so that the outer diameter of the ring 10 is smaller than the inner diameter of the core 7, and the fixing ring 10 is placed between the protrusions 9 on the inner surface of the core 7 as shown by the solid line from the chain line in FIG. The fixing ring 10 is expanded on the inner surface of the core 7 by using a simple jig such as a snap ring pliers 20 or a vise (see FIG. 6B), and the locking piece 15 being seen from the hole 12 is shown in FIG. And it bends like FIG.6 (c) and it fixes so that the fixing ring 10 may not shrink in the circumferential direction.
[0019]
At this time, even if the pipe P has the same outer diameter, the inner peripheral length of the pipe differs depending on the pipe thickness and the lining layer, and accordingly, the tip (neck) 11a to be engaged with the long hole 14 is appropriately selected according to the inner peripheral length. . FIG. 7 shows an example. When the inner peripheral length of the pipe is long (the inner diameter of the pipe is large), the most advanced neck portion 11a and the both diameter-expanding holes (jig holes) 16 provided at the other end 13 are used. The diameter of the ring 10 is increased (d), and the inner neck portion 11a is selected as the inner peripheral length of the pipe becomes shorter (the inner diameter of the pipe becomes smaller), so that the distance between the diameter-expanding holes 16 and 16 is made substantially constant L ₁ . Since it becomes possible to maintain, it becomes possible to give the ring 10 the optimal diameter expansion force.
[0020]
When the fixing ring 10 is fixed (expanded diameter) to the inner surface of the anticorrosion core 7 by this method, the diameter of the inner surface of the core 7 is measured in a state where the anticorrosion core 7 is fitted to the pipe end, and the inner peripheral length of the pipe is calculated from this value. Then, the neck portion 11a that is optimal for the length is selected, and after the extra neck portion 11a is cut, the fixing ring 10 is made into an annular shape by multiplying both ends 11 and 13 thereof, or the extra neck portion is formed after making the annular shape. 11a is cut | disconnected, after that, it fits in the anticorrosion core 7, expands in diameter, and is attached. At this time, in consideration of the workability at the site, if the pipe inner circumference is calculated in advance with respect to the diameter, and a quick reference table is prepared for the numerical value and the neck 11a to be selected, the neck that is selected only by measuring the diameter Since 11a is known, selection errors are less likely to occur during installation. For example, a number that matches the circumference may be given to each neck portion 11a.
[0021]
By attaching the fixing ring 10 to the inner surface of the core 7 in this way, in addition to preventing the core 7 from dropping off due to the water flow, the plurality of neck portions 11a are appropriately selected according to the inner circumferential length of the pipe, By multiplying the elongated holes 14 with the diameter-expanding holes 16 and 16 substantially constant, it is possible to give the fixing ring 10 an optimum diameter-expanding force, and the length of the elongated hole 14 and the tip 11 can absorb the circumferential dimension tolerance of the inner diameter of the tube by the number of the neck portions 11a provided in the ring 11, the ring 10 can be smoothly fixed to the core 7, and the diameter of the core 7 can be prevented by the locking piece 15 for a long period of time. It is firmly fixed to the end of the tube to prevent red water. In the above embodiment, the number of the neck portions 11a has been described as four. However, it goes without saying that the number can be increased or decreased depending on the tube diameter without regard to the number.
[0022]
The embodiment of FIG. 8 is formed with a hollow 17 and the shape of the hollow 17 can be an arbitrary shape such as a long hole (FIG. 8A), a circular hole (FIG. 8B), a square hole, or the like. It is. This lightening 17 is for facilitating bending of the fixing ring 10, and therefore, the number and position are set to that extent. If it becomes easy to bend, it is advantageous if the inner peripheral length is shortened (in the case of a small-diameter pipe).
[0023]
As shown in FIG. 9, when the rising wall 16a is formed around the diameter expansion hole 16, the wall 16a is reinforced when the ring 10 is expanded or contracted by a jig such as the snap ring pliers 20 or the like. The jig 20 is difficult to be removed from the hole 16, and the operation is smooth. The wall 16a may be formed by cutting and raising when the hole 16 is formed. If the wall 16a is an inclined wall as shown in FIG.
[0024]
Moreover, it can replace with the diameter expansion hole 16, and can also be used as a latching protrusion. For this reason, the “expansion hole 16” includes a “locking protrusion”. For example, as shown in FIGS. 10A to 10C, a projection 18 bulged in an arc shape can be adopted, and this projection 18 is engaged with the jig 20 as shown in FIG. To do. At this time, the locking hole 18a of the jig 20 may be formed in the protrusion 18 as shown in FIG.
[0025]
Further, if the locking piece 15 is annealed over its entire length by high frequency or the like, the locking piece 15 can be easily bent, its workability is improved, and it can be bent firmly and its locked state is stabilized. . This annealing is effective when the fixing ring 10 is an elastic material.
[0026]
Needless to say, the fixing ring 10 according to the present invention can also be applied to the groove 8 as shown in FIG. 14, and is not limited to the NS type joint, and is applied to all pipe ends to which the anticorrosion core 7 is fitted and fixed. Of course you can.
[0027]
【The invention's effect】
As described above, since the present invention provides the fixing ring with the function of preventing the diameter reduction, the aging degradation of the diameter expansion force of the fixing ring is also suppressed, and therefore, the sufficient adhesion to the tube end of the waterproof core has also been maintained for many years. It is maintained over a long period of time, and red water can be prevented over a long period of time.
[0028]
In addition, since a plurality of neck portions are provided, it is easy to cope with changes in the inner peripheral length of the tube, and it is not necessary to lengthen the locking piece, and therefore there are few portions protruding on the inner surface of the tube.
[Brief description of the drawings]
1 is a perspective view of an essential part of one embodiment. FIG. 2A is a cross-sectional view taken along line AA in FIG. 1, and FIG. 1B is a cross-sectional view taken along line BB. Core installation explanatory diagram [Fig. 4] Mounting action diagram of fixing ring of the same embodiment [Fig. 5] Plan view of one embodiment of the fixing ring [Fig. 6] Mounting action diagram of the fixing ring [Fig. FIG. 8 is a plan view of each embodiment of another fixing ring. FIG. 9 is a cross-sectional view of a main part of each of the other embodiments. FIG. 10 is a perspective view or a cross-sectional view of a main part of the other embodiment. FIG. 11 shows a conventional fixing ring, (a) is a plan view, (b) is an operation diagram. FIG. 12 is an operation diagram of the conventional example. FIG. 13 is a cross-sectional view of the main part of a pipe joint. Expanded sectional view of the main part of the pipe insertion opening [Explanation of symbols]
1, 2 Tube 1a Receptor 2a Insert 7 Corrosion-proof core 9 Fixing ring positioning projection 10 Corrosion-proof core fixing ring 11 One end (tip) of the fixing ring
11a One end neck portion 12 Locking piece insertion hole 13 The other end 14 of the fixing ring 10 Long hole 15 Locking piece 16 Diameter expansion hole 18 Locking protrusion 20 Snap ring pliers (diameter expansion jig)

Claims

A fixing ring 10 is provided over the inner circumference of the cylindrical portion inserted into the inner surface of the tube end portion of the tube end anticorrosion core 7 and fixes the anticorrosion core 7 by pressing the cylindrical portion against the inner surface of the tube end portion. ,
The neck portion 11a is narrowed at one end 11 in the circumferential direction, and a narrow neck portion 11a is formed in a plurality of stages in the length direction, and a hole 12 is formed on the other end 13 side from the neck portion 11a. The other end 13 has a long hole 14 formed in the circumferential direction of the fixing ring 10 into which the one end 11 is slidably inserted via the neck portion 11 a and is inserted through the hole 12 in the one end 11. A locking piece 15 extending toward the one end 11 is provided. The width of the one end 11 is wider than that of the long hole 14 to prevent the locking piece 15 from being pulled out, and the locking piece 15 is inserted into the hole 12 and folded back. Accordingly, the pipe ring anticorrosion core fixing ring is provided with a function of preventing the diameter reduction of the fixing ring 10.

The fixing ring 10 according to claim 1 is fitted in a pressure contact state over the entire inner surface of the cylindrical portion inserted into the inner surface of the tube end portion of the tube end anticorrosion core 7, and both ends 11 and 13 of the fixing ring 10 are overlapped. The one end 11 is inserted into a long hole 14 at the other end 13 through a required neck portion 11 a and is prevented from coming off, and the locking piece 15 at the other end 13 is inserted into the hole 12 at the one end 11. A structure for fixing a pipe end anticorrosion core, which is folded and provided with a function of preventing the diameter reduction of the fixing ring 10 by the folding.

Both ends 11 and 13 of the fixing ring 10 according to claim 1 are overlapped, and one end 11 thereof is inserted into a long hole 14 of the other end 13 through a required neck portion 11a to prevent it from coming off and to make an annular shape. The locking piece 15 of the end 13 is inserted into the hole 12 of the end 11, and the annular fixing ring 10 is fitted and expanded in a press-contact state on the entire inner surface of the cylindrical portion inserted into the inner surface of the tube end portion of the tube end anticorrosive core 7. Thereafter, the locking piece 15 is folded back and the pipe end anticorrosion core is secured by folding back to the elongated hole 14 at one end of the fixing ring 10. The tube end anticorrosive core is fixed by cutting the tip from the neck portion 11a before or after the end 10 is inserted into the long hole 12.