JP3682173B2

JP3682173B2 - Pipe connection structure

Info

Publication number: JP3682173B2
Application number: JP30256398A
Authority: JP
Inventors: 和芳山本; 誠一人見
Original assignee: Sekisui Chemical Co Ltd
Current assignee: Sekisui Chemical Co Ltd
Priority date: 1998-10-23
Filing date: 1998-10-23
Publication date: 2005-08-10
Anticipated expiration: 2018-10-23
Also published as: JP2000130659A

Description

【０００１】
【発明の属する技術分野】
本発明は、離脱防止機能を有した管接続構造に関する。
【０００２】
【従来の技術】
接続される管の差口を、管継手の受口内に挿入するだけで簡単に接続可能で、しかも離脱防止機能を有する管継手として、特開平１０−１２２４６１号公報に記載されているものがある。この離脱防止管継手は、円筒状の継手本体と、略Ｃリング状の離脱防止リングと、補強部材とを備えている。
【０００３】
【発明が解決しようとする課題】
しかしながら、上記従来の管継手で用いられる補強部材は、差口本体を補強する部材ではあるが、耐水圧強度を発現するための好適な効果が得られる形状としては、不十分な場合があった。
【０００４】
また、従来の管継手は、補強部材の折り返し部の外径が差口の外径を越えているため、補強部材を装着した差口を受口に挿入する際に、管締付け用の割りリングの係止突起の刃先を傷つけてしまい、十分な離脱防止効果が得られなくなるという問題点が生じる場合があった。
【０００５】
しかしながら、ステンレス製のものではその内周面に形成されている鋸歯状の刃が硬すぎるため、たとえば挿入接続される管がポリエチレン樹脂管などのポリオレフィン樹脂管の場合、この樹脂管の外周面を削ってしまうなど、著しく傷つけてしまうため、その離脱防止効果は低かった。また、ステンレス製の離脱防止リングの場合はその剛性が高すぎるがために、管継手の受口内への離脱防止リングの装着が困難であった。
【０００６】
本発明の目的は、特にポリオレフィン樹脂管と離脱防止管継手との管接続構造として、すぐれた耐水圧性能を発揮する管接続構造を提供することである。
【０００７】
【課題を解決するための手段】
請求項１記載の発明は、継手本体の開口端部側の内周面に設けられた環状凹溝内にシール用ゴム輪が装着され、このゴム輪よりも奥側に位置する継手本体の内周面が奥部に向かって拡径する傾斜溝を有し、この傾斜溝内に、その内周面にほぼ符合した傾斜外周面を有する管締付け用の割りリングが遊嵌状態で配置されてなる受口内に、差口内に円筒状の補強部材が装着された樹脂管の差し口が挿入接続されてなる管接続構造において、前記補強部材の外径が樹脂管の差口の内径の９７．５〜９９．８％とされ、補強部材の一端部が外方に折り返えされて折り返し部とされ、この折り返し部の最大外径が樹脂管の差口の外径の９０〜１００％とされているものである。
【０００８】
請求項２記載の発明は、請求項１記載の管接続構造において、補強部材の外面に突起が設けられ、突起高さが０．３〜１．５ｍｍであるものである。
請求項３記載の発明は、請求項１又は２記載の管接続構造において、補強部材の折り返し部は、円筒部の一端部が外方に傘状に折り返されて傾斜面とされており、折り返し面はＲがつけられているものである。
【０００９】
本発明においては、管締付け用の割りリングは、半径方向に拡縮自在となっており、材質としては金属製あるいは樹脂製のどちらでもよいが、耐水性などの面から、ポリアセタール、ポリアミド、ポリスルホン、ポリフェニレンサルファイド、ポリエーテルエーテルケトンなどの樹脂製のものが望ましい。そして、この割りリングの内径はその自由状態において、挿入接続されるポリオレフィン系樹脂管の外径より少し小径とされ、その内周面の周方向に沿って複数の係止突条（たとえば鋸歯状のもの）を備えているのが望ましい。
【００１０】
本発明においては、樹脂管の差口内に装着される円筒状の補強部材の外径は樹脂管の差口の内径の９７．５〜９９．８％、特に好ましくは、９８．０〜９９．５％である。これは、補強部材の外径が樹脂管の差口の内径の９７．５％未満では、接続部の十分な耐水圧性能が得られないからである。つまり、補強部材としての補強が不十分であり、内水圧がかかった時に、受口から差口が抜けてしまうなどの問題が生じるためである。また、逆に、補強部材の外径が樹脂管の差口の内径の９９．８％を越えると、差口への装着が困難となるからである。
【００１１】
そして、補強部材の折り返し部の最大外径は樹脂管の差口の外径の９０〜１００％、特に好ましくは、９５〜１００％とするのが望ましい。これは、折り返し部の最大外径が樹脂管の差口の外径を越えると、補強部材を装着した差口を受口内に挿入する際に、管締付け用の割りリングの係止突条の刃先を傷つけてしまうため、十分な離脱防止効果を得ることができなくなるからである。また、折り返し部が大きくなる分の受口の内周面を大きくする必要があり、その場合にも接合部の強度が不十分となるからである。
【００１２】
逆に、折り返し部の最大外径が樹脂管の差口の外径の９０％未満の場合には、差口と補強部材の折り返し部に大きな段差が生じることになり、補強部材を装着した差口を受口内に挿入する際に、管締付け用の割りリングの刃先を傷つけてしまい、十分な離脱防止効果を得ることができなくなるからである。
【００１３】
また、折り返し部の先端が尖っていると、管締付け用の割りリングの刃先を傷つけるので、補強部材の折り返し部の先端に面取りを施したり、あるいは数ｍｍ程度の平行部を設けるのが望ましい。
【００１４】
樹脂管の差口内から補強部材の抜けを防止するために、補強部材の外面にすべり止め手段としての多数の突起を設けるのが望ましい。この突起の高さとしては、差口の内径と補強部材の外径の大小にもよるが、０．３〜１．５ｍｍが好ましい。これは、突起の高さが０．３ｍｍ未満では、すべり止め効果が少なく、また、逆に突起の高さが１．５ｍｍを越えると、差口の内面を著しく傷つけるか、あるいは樹脂管の差口内への補強部材の装着が困難となるからであり、かつ、差口の内径と補強部材の筒部外周径の差が大きくなり、接続部での十分な耐水圧性能が得られないからである。
【００１５】
補強部材の材質は、鋳鉄、アルミニウムなどの金属製のものの他、ガラス繊維や炭素繊維などの補強繊維にて補強されたＦＲＰ製のものであってもよい。耐水性を考慮した場合には、ステンレス鋼製が好ましい。折り返し部は、円筒部の一端部が外方に傘状に折り返されて傾斜面とされており、差口を受口にスムースに挿入できるように、１０〜５０度の傾斜角度とするのが望ましい。また、折り返し面は鋭角に折り返さず、Ｒをつけた方が好ましい。補強部材の長さは継手本体の受口の挿入代とほぼ同一とするのが望ましい。これは、その長さが短すぎるとゴム輪からの締め力による樹脂管のコールドフローを抑止する効果がなく、逆に長過ぎても、さらなる効果は期待できず不経済となるからである。
【００１６】
【発明の実施の形態】
以下、本発明の管接続構造の実施の形態を図面に基づいて説明する。
図１は本発明の管接続構造の第１実施例を示す半縦断面図、図２は図１における離脱防止管継手の部分を示す半縦断面図、図３は図１における補強部材を示す半縦断面図である。
【００１７】
図１において、樹脂管５、７はともに密度が０．９４０以上の高密度ポリエチレン樹脂から押出成形されたものである。樹脂管７の一端面には、受け口を有する管継手１の小径側の端面がバット融着されて両者が一体化されている。そして、差口５１の内周面側に短円筒状の補強部材６が内挿された樹脂管５の差口５１が、管継手１の受口内に挿入接続されることで樹脂管５と樹脂管７との接続構造が形成されている。
【００１８】
管継手１は離脱防止機能を有するタイプのものであり、継手本体２と、管締付け用の割りリング３と、シール用ゴム輪４とを備えている。継手本体２はポリエチレン樹脂製の円筒状のものであり、その大径側の一端部は接続される樹脂管５の挿入口を備えた受口を有しており、挿入口側の内周面に環状凹溝２１が設けられ、この環状凹溝２１内にシール用ゴム輪４が装着されている。このゴム輪４よりも奥側に位置する継手本体２の内周面２２は奥部に向かってテーパ面状に拡径されて傾斜溝２３とされている。
【００１９】
この傾斜溝２３内には、管締付け用の割りリング３が遊嵌状態で配置されている。この割りリング３はその管壁の一部が切り欠かれており、傾斜溝２３の内周面２２にほぼ符合した傾斜外周面３１を有している。割りリング３はその自由状態において、その内径が後述する樹脂管５の差口５１の外径より少し小さくなるようにされており、その内周面に多数の鋸歯状の係止突条３２が設けられている。割りリング３は直鎖型ポリフェニレンサルファイド樹脂から射出成形法にて成形されており、この場合、直鎖型ポリフェニレンサルファイド樹脂はその曲げ弾性率が３６３０ＭＰａ、ノッチ付アイゾット衝撃値が２５Ｊ／ｍの機械的性質を有しているものを使用した〔ポリプラスチック株式会社の「フォートロン」（登録商標）：グレード０２２０Ｕ９〕。
【００２０】
補強部材６は耐蝕性を有するステンレス鋼製のものであり、図３に示すように、短円筒部６１と折り返し部６２とを備えており、短円筒部６１の外径は樹脂管５の差口５１の内径の９７．５〜９９．８％とされている。短円筒部６１の外周面には、図３に示すように、すべり止め手段としての小突起６３が切り起こされて周方向の４ヵ所に設けられている。折り返し部６２は、短円筒部６１の一端部が外方に傘状に折り返されてテーパ面とされている。
【００２１】
そして、図に示すように、折り返し部６２の先端が樹脂管５の差口５１端面の外周縁を囲繞するようになっており、折り返し部６２の最大外径の大きさは、樹脂管５の差口５１の外径の９０〜１００％とされている。
【００２２】
そして、樹脂管５の差口５１を管継手１の挿入口から奥側に向かって挿入すると、補強部材６の折り返し部６２の外周面のテーパ面６４によって割りリング３が押し広げられるので、奥側まで挿入することができる。なお、継手本体２の受け口の奥部内周面には、補強部材６の折り返し部６２の外周面が当接する当接段部２４が形成されている。
【００２３】
この場合、割りリング３が直鎖型ポリフェニレンサルファイド樹脂製のものであるので、拡径によって塑性変形や割れを起こすことがなく、その弾性復元力によって樹脂管５の外径より少し小さい内径の元の自由状態まで縮径することになる。
【００２４】
さらに、管継手１は、折り返し部６２の先端が割りリング３より奥側まで挿入されると、樹脂管５あるいは管継手１に樹脂管５の抜け方向の力が作用した場合、割りリング３の鋸歯状の係止突条３２の働きにより、樹脂管５の動きにともなって割りリング３も挿入口側へ移動してその外周面３１が傾斜溝２３のテーパ面２２に押し当たり、割りリング３が縮径する。したがって、樹脂管５の差口５１の外周面が割りリング３の内周面にしっかりと把持され、樹脂管５の抜け止めが確実に行われる。
【００２５】
また、樹脂管５の差口５１内に、補強部材６の短円筒部６１が圧入嵌合されることで、差口５１が内側から補強されているので、割りリング３やシール用ゴム輪４によって締付け力が長期間にわたって継続して樹脂管５に加えられても、樹脂管５の差口５１がコールドフローによって寸法変形を起こすことがない。しかも、補強部材６の短円筒部６１の外周面にすべり止め手段としての小突起６３が周方向の４箇所に設けられているので、補強部材６を継手本体２内に残した状態で樹脂管５の差口５１がすべり抜けるというトラブルも確実に防止できる。
【００２６】
【実施例１〜３】
上記高密度ポリエチレン樹脂製の樹脂管５、７として呼び径７５ｍｍのものを用い、接続部の耐水圧性能を行った。具体的には、両樹脂管５、７の開口端を栓体にて閉塞し、この閉塞した両樹脂管５、７を所定の受け台上に載置して支持する。なお、樹脂管７側の栓体は加圧ポンプと接続され、被試験体内に所定の内水圧を付与できるようになっている。
そして、補強部材６の外径（ｄ３）と樹脂管５の差口５１の内径（ｄ１）との寸法比（ｄ３／ｄ１）、補強部材６の折り返し部の外径（ｄ４）と樹脂管５の差口５１の外径（ｄ２）との寸法比（ｄ４／ｄ２）を変化させた各接続構造について、加圧ポンプにて２．５ＭＰａまでの内水圧を負荷して２分間保持し、その後、管の破壊最高圧力５．０ＭＰａ前後までの内水圧を負荷して接続部からの漏れおよび異常の有無を確認した。
なお、ｄ３／ｄ１比が０．９６７〜０．９７２のものを比較例１〜３、ｄ４／ｄ２比が０．８９３、１．００８〜１．０１２のものを比較例４〜６として同様に評価した。その結果を表１および表２に示す。
耐水圧試験の欄で、○印は管の破壊最高圧力５．０ＭＰａまで内水圧を負荷しても、漏水や管の抜けなどの接続部の異常がなかったことを示し、×印は接続部に異常があったことを示す。
表１に示すように、ｄ３／ｄ１比が０．９７５〜０．９９８の範囲内で、かつ、ｄ４／ｄ２比が０．９００〜１．０００であれば、十分に止水できることが明らかである。
なお、呼び径が１００ｍｍおよび１５０ｍｍの樹脂管５、７についても、上記と同様に性能評価した結果、表１に示すとおりの性能を得ることができた。
【００２７】
【表１】

【００２８】
【表２】

【００２９】
本発明においては、上記の実施の形態に限定されない。たとえば、上記実施例では、継手本体２の一側にのみ樹脂管５を接続するようにしたが、継手本体２の両側に樹脂管５を接続できる構造にしてもよい。
【００３０】
【発明の効果】
請求項１記載の本発明の管接続構造では、補強部材の外径が樹脂管の差し口の内径の９７．５〜９９．８％とされ、補強部材の一端部が外方に折り返えされて折り返し部とされ、この折り返し部の最大外径が樹脂管の差口の外径の９０〜１００％とされていることにより、受口内に挿入接続される樹脂管の差口が補強部材にて好適に補強され、この結果、受口内からの樹脂管の差口の抜けを管締付け用の割りリングにて防止することができるとともに、受口内に樹脂管の差口を挿入する際に、補強部材の折り返し部先端が管締付け用の割りリングの係止突条の刃先を傷つけることがなく、すぐれた耐水圧性能を発揮することができる。
【００３１】
請求項２記載の本発明では、補強部材の外面に突起が設けられ、突起高さが０．３〜１．５ｍｍであるので、樹脂管の差口内から補強部材の抜けを防止することができ、上記効果は更に確実なものとなる。
請求項３記載の本発明では、補強部材の折り返し部は、円筒部の一端部が外方に傘状に折り返されて傾斜面とされており、折り返し面はＲがつけられているので、差口を受口にスムースに挿入でき、上記効果は更に確実なものとなる。
【図面の簡単な説明】
【図１】本発明の管接続構造の第１実施例を示す半縦断面図である。
【図２】図１における接続前の管継手を示す半縦断面図である。
【図３】図１における補強部材を示す半縦断面図である。
【符号の説明】
１管継手
２継手本体
２１環状凹溝
２２内周面
２３傾斜溝
３管締付け用の割りリング
３１傾斜外周面
３２鋸歯状の係止突条
４シール用ゴム輪
５、７樹脂管
５１差口
６補強部材
６１短円筒部
６２折り返し部
６３小突起[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe connection structure having a detachment preventing function.
[0002]
[Prior art]
Japanese Laid-Open Patent Publication No. 10-122461 discloses a pipe joint that can be easily connected by simply inserting a pipe outlet into a pipe joint receptacle and has a function of preventing detachment. . This detachment prevention pipe joint includes a cylindrical joint body, a substantially C-ring detachment prevention ring, and a reinforcing member.
[0003]
[Problems to be solved by the invention]
However, the reinforcing member used in the above-described conventional pipe joint is a member that reinforces the main body of the gap, but there are cases where it is insufficient as a shape that can provide a suitable effect for expressing the water pressure resistance. .
[0004]
In addition, since the outer diameter of the folded portion of the reinforcing member exceeds the outer diameter of the outlet in the conventional pipe joint, the split ring for tightening the pipe is inserted when inserting the outlet with the reinforcing member into the receptacle. In some cases, the edge of the locking projection is damaged, and a sufficient detachment preventing effect cannot be obtained.
[0005]
However, since the sawtooth blade formed on the inner peripheral surface of the stainless steel one is too hard, for example, when the pipe to be inserted and connected is a polyolefin resin pipe such as a polyethylene resin pipe, the outer peripheral surface of the resin pipe is Since it was severely damaged, such as by shaving, its removal preventing effect was low. In addition, in the case of a stainless steel release prevention ring, its rigidity is too high, so it was difficult to mount the release prevention ring into the pipe joint receiving port.
[0006]
An object of the present invention is to provide a pipe connection structure that exhibits excellent water pressure resistance, particularly as a pipe connection structure between a polyolefin resin pipe and a detachment prevention pipe joint.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, a sealing rubber ring is mounted in an annular groove provided on the inner peripheral surface on the opening end side of the joint body, and the inner side of the joint body located on the back side of the rubber ring. The peripheral surface has an inclined groove whose diameter increases toward the inner part, and a split ring for pipe tightening having an inclined outer peripheral surface substantially coincident with the inner peripheral surface is disposed in the inclined groove in a loosely fitted state. In the pipe connection structure in which the insertion port of the resin tube having the cylindrical reinforcing member mounted therein is inserted and connected in the receiving port, the outer diameter of the reinforcing member is 97. 5 to 99.8% , one end portion of the reinforcing member is folded outward to be a folded portion, and the maximum outer diameter of the folded portion is 90 to 100% of the outer diameter of the resin pipe outlet. It is what has been.
[0008]
According to a second aspect of the present invention, in the pipe connection structure according to the first aspect, a protrusion is provided on the outer surface of the reinforcing member , and the protrusion height is 0.3 to 1.5 mm .
According to a third aspect of the present invention, in the pipe connection structure according to the first or second aspect, the folded portion of the reinforcing member has an inclined surface formed by folding one end of the cylindrical portion outwardly in an umbrella shape. The surface is marked with R.
[0009]
In the present invention, the split ring for tightening the pipe is radially expandable and contractable, and the material may be either metal or resin, but from the viewpoint of water resistance, polyacetal, polyamide, polysulfone, Those made of resin such as polyphenylene sulfide and polyether ether ketone are desirable. The inner diameter of the split ring is a little smaller than the outer diameter of the polyolefin-based resin pipe to be inserted and connected in the free state, and a plurality of locking protrusions (for example, saw-toothed) are formed along the circumferential direction of the inner peripheral surface. Preferably).
[0010]
In the present invention, the outer diameter of the cylindrical reinforcing member mounted in the outlet of the resin pipe is 97.5 to 99.8%, particularly preferably 98.0 to 99.%, of the inner diameter of the outlet of the resin pipe. 5%. This is because if the outer diameter of the reinforcing member is less than 97.5% of the inner diameter of the resin pipe outlet, sufficient water pressure resistance of the connecting portion cannot be obtained. In other words, the reinforcement as the reinforcing member is insufficient, and problems such as a gap coming out from the receiving port occur when internal water pressure is applied. Conversely, if the outer diameter of the reinforcing member exceeds 99.8% of the inner diameter of the resin pipe outlet, it is difficult to attach the reinforcing member to the outlet.
[0011]
The maximum outer diameter of the folded portion of the reinforcing member is 90 to 100%, particularly preferably 95 to 100%, of the outer diameter of the resin pipe outlet. This is because when the maximum outer diameter of the folded portion exceeds the outer diameter of the resin pipe outlet, when inserting the reinforcing member-attached outlet into the receiving opening, This is because the blade edge is damaged, and a sufficient separation preventing effect cannot be obtained. Moreover, it is necessary to enlarge the inner peripheral surface of the receiving port as the folded portion becomes larger, and in this case, the strength of the joint portion is insufficient.
[0012]
On the other hand, when the maximum outer diameter of the folded portion is less than 90% of the outer diameter of the resin pipe outlet, a large step will be formed between the outlet and the folded portion of the reinforcing member, and the difference between the attachment of the reinforcing member. This is because, when inserting the opening into the receiving opening, the cutting edge of the split ring for tightening the tube is damaged, and a sufficient detachment preventing effect cannot be obtained.
[0013]
Further, if the tip of the folded portion is sharp, the cutting edge of the split ring for pipe tightening is damaged, so it is desirable to chamfer the tip of the folded portion of the reinforcing member or to provide a parallel portion of about several mm.
[0014]
In order to prevent the reinforcing member from coming off from the inside of the resin pipe, it is desirable to provide a large number of protrusions as anti-slip means on the outer surface of the reinforcing member. The height of the protrusion is preferably 0.3 to 1.5 mm, although it depends on the inner diameter of the opening and the outer diameter of the reinforcing member. This is because the anti-skid effect is small if the height of the protrusion is less than 0.3 mm, and conversely, if the height of the protrusion exceeds 1.5 mm, the inner surface of the gap is markedly damaged, or the difference in resin pipes This is because it is difficult to attach the reinforcing member in the mouth, and the difference between the inner diameter of the opening and the outer peripheral diameter of the cylindrical portion of the reinforcing member is large, and sufficient water pressure resistance performance at the connecting portion cannot be obtained. is there.
[0015]
The material of the reinforcing member may be made of FRP reinforced with reinforcing fibers such as glass fiber and carbon fiber in addition to those made of metal such as cast iron and aluminum. In consideration of water resistance, stainless steel is preferable. The folded portion has an inclined angle of 10 to 50 degrees so that one end portion of the cylindrical portion is folded outwardly in an umbrella shape to form an inclined surface, and the insertion port can be smoothly inserted into the receiving port. desirable. Further, it is preferable that the folded surface is not folded at an acute angle and is given an R. It is desirable that the length of the reinforcing member is substantially the same as the insertion allowance of the joint body receptacle. This is because if the length is too short, there is no effect of inhibiting the cold flow of the resin pipe due to the tightening force from the rubber ring, and conversely if it is too long, no further effect can be expected and it becomes uneconomical.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the pipe connection structure of the present invention will be described below with reference to the drawings.
FIG. 1 is a half longitudinal sectional view showing a first embodiment of the pipe connection structure of the present invention, FIG. 2 is a half longitudinal sectional view showing a part of a separation preventing pipe joint in FIG. 1, and FIG. 3 shows a reinforcing member in FIG. FIG.
[0017]
In FIG. 1, resin tubes 5 and 7 are both extruded from a high density polyethylene resin having a density of 0.940 or more. The end face of the small diameter side of the pipe joint 1 having a receiving port is butt-fused to one end face of the resin pipe 7 so as to integrate them. Then, the resin pipe 5 and the resin are inserted into the receiving port of the pipe joint 1 by inserting the connecting port 51 of the resin tube 5 in which the short cylindrical reinforcing member 6 is inserted into the inner peripheral surface side of the connecting port 51. A connection structure with the tube 7 is formed.
[0018]
The pipe joint 1 is of a type having a detachment preventing function, and includes a joint body 2, a pipe tightening split ring 3, and a seal rubber ring 4. The joint body 2 has a cylindrical shape made of polyethylene resin, and one end portion on the large diameter side has a receiving port provided with an insertion port for the resin pipe 5 to be connected, and the inner peripheral surface on the insertion port side. An annular groove 21 is provided in the annular groove 21, and a sealing rubber ring 4 is mounted in the annular groove 21. The inner peripheral surface 22 of the joint main body 2 located on the back side of the rubber ring 4 is enlarged in a tapered surface shape toward the back portion to form an inclined groove 23.
[0019]
In the inclined groove 23, a split ring 3 for pipe tightening is arranged in a loosely fitted state. The split ring 3 has a part of the tube wall cut away, and has an inclined outer peripheral surface 31 substantially coinciding with the inner peripheral surface 22 of the inclined groove 23. In the free state, the split ring 3 is configured such that its inner diameter is slightly smaller than the outer diameter of a later-described outlet 51 of the resin pipe 5, and a large number of sawtooth-shaped locking protrusions 32 are formed on the inner peripheral surface thereof. Is provided. The split ring 3 is molded from a linear polyphenylene sulfide resin by an injection molding method. In this case, the linear polyphenylene sulfide resin has a bending elastic modulus of 3630 MPa and a notched Izod impact value of 25 J / m. A material having properties was used [Polyplastic Co., Ltd. "Fortron" (registered trademark): Grade 0220U9].
[0020]
The reinforcing member 6 is made of stainless steel having corrosion resistance and includes a short cylindrical portion 61 and a folded portion 62 as shown in FIG. 3. The outer diameter of the short cylindrical portion 61 is different from that of the resin tube 5. The inner diameter of the mouth 51 is 97.5 to 99.8%. As shown in FIG. 3, small protrusions 63 as anti-slip means are cut and raised on the outer peripheral surface of the short cylindrical portion 61 and provided at four locations in the circumferential direction. The folded portion 62 has a tapered surface in which one end portion of the short cylindrical portion 61 is folded outward in an umbrella shape.
[0021]
As shown in the figure, the tip of the folded portion 62 surrounds the outer peripheral edge of the end surface of the differential port 51 of the resin tube 5, and the maximum outer diameter of the folded portion 62 is the size of the resin tube 5. The outer diameter of the difference port 51 is 90 to 100%.
[0022]
When the insertion port 51 of the resin pipe 5 is inserted from the insertion port of the pipe joint 1 toward the back side, the split ring 3 is pushed and widened by the tapered surface 64 of the outer peripheral surface of the folded portion 62 of the reinforcing member 6. Can be inserted to the side. Note that a contact step portion 24 is formed on the inner peripheral surface of the inner portion of the joint body 2 at the back of the outer periphery of the folded portion 62 of the reinforcing member 6.
[0023]
In this case, since the split ring 3 is made of a linear polyphenylene sulfide resin, it does not cause plastic deformation or cracking due to expansion of the diameter, and its elastic restoring force causes an inner diameter slightly smaller than the outer diameter of the resin tube 5. The diameter is reduced to the free state.
[0024]
Furthermore, when the tip of the folded portion 62 is inserted deeper than the split ring 3, the pipe joint 1 is configured such that when a force in the removal direction of the resin pipe 5 acts on the resin pipe 5 or the pipe joint 1, Due to the action of the serrated locking ridge 32, the split ring 3 also moves to the insertion port side in accordance with the movement of the resin tube 5, and the outer peripheral surface 31 presses against the tapered surface 22 of the inclined groove 23. Decreases in diameter. Accordingly, the outer peripheral surface of the outlet 51 of the resin tube 5 is firmly held by the inner peripheral surface of the split ring 3, and the resin tube 5 is reliably prevented from coming off.
[0025]
In addition, since the short cylindrical portion 61 of the reinforcing member 6 is press-fitted into the insertion opening 51 of the resin pipe 5, the insertion opening 51 is reinforced from the inside, so that the split ring 3 and the rubber band 4 for sealing are used. Therefore, even if the tightening force is continuously applied to the resin pipe 5 for a long period of time, the differential opening 51 of the resin pipe 5 is not deformed by cold flow. In addition, since the small protrusions 63 as the slip preventing means are provided at four locations in the circumferential direction on the outer peripheral surface of the short cylindrical portion 61 of the reinforcing member 6, the resin pipe is left in a state in which the reinforcing member 6 remains in the joint body 2. It is possible to reliably prevent the trouble that the five differential openings 51 slip out.
[0026]
Examples 1 to 3
The resin pipes 5 and 7 made of high-density polyethylene resin were those having a nominal diameter of 75 mm, and the water pressure resistance performance of the connecting portions was performed. Specifically, the open ends of both resin pipes 5 and 7 are closed with plugs, and the closed resin pipes 5 and 7 are placed on and supported on a predetermined cradle. The plug body on the resin tube 7 side is connected to a pressurizing pump so that a predetermined internal water pressure can be applied to the body under test.
Then, the dimensional ratio (d3 / d1) between the outer diameter (d3) of the reinforcing member 6 and the inner diameter (d1) of the differential port 51 of the resin tube 5, the outer diameter (d4) of the folded portion of the reinforcing member 6 and the resin tube 5 For each connection structure in which the dimensional ratio (d4 / d2) to the outer diameter (d2) of the difference port 51 is changed, an internal water pressure of up to 2.5 MPa is loaded with a pressure pump and held for 2 minutes. In addition, the internal water pressure up to around 5.0 MPa at the maximum breaking pressure of the tube was loaded, and the presence or absence of leakage from the connecting portion and abnormality was confirmed.
Similarly, those having a d3 / d1 ratio of 0.967 to 0.972 are comparative examples 1 to 3, and those having a d4 / d2 ratio of 0.893 and 1.008 to 1.012 are comparative examples 4 to 6. evaluated. The results are shown in Tables 1 and 2.
In the column of the water pressure resistance test, ○ indicates that there was no abnormality in the connection part such as water leakage or pipe disconnection even when the internal water pressure was applied up to the maximum breaking pressure of the pipe of 5.0 MPa. Indicates that there was an abnormality.
As shown in Table 1, it is clear that the water can be sufficiently stopped if the d3 / d1 ratio is in the range of 0.975 to 0.998 and the d4 / d2 ratio is 0.900 to 1.000. is there.
As a result of evaluating the performance of the resin pipes 5 and 7 having nominal diameters of 100 mm and 150 mm in the same manner as described above, the performance shown in Table 1 was obtained.
[0027]
[Table 1]

[0028]
[Table 2]

[0029]
The present invention is not limited to the above embodiment. For example, in the above embodiment, the resin pipe 5 is connected only to one side of the joint body 2, but the resin pipe 5 may be connected to both sides of the joint body 2.
[0030]
【The invention's effect】
The tube connection structure of the present invention of claim 1 Symbol mounting, the outer diameter of the reinforcing member is a 97.5 to 99.8% of the inner diameter of the spigot of the resin pipe, one end portion of the reinforcing member is returned folded outwardly As a result, the maximum outer diameter of the folded portion is 90 to 100% of the outer diameter of the resin pipe outlet, thereby reinforcing the resin pipe outlet inserted and connected into the receptacle. are suitably reinforced by members, this result, Rutotomoni can prevent omission of the difference port of the resin pipe from the receptacle at a split ring for clamping the tube, inserting the difference port of the resin pipe in the receptacle At this time, the tip of the folded portion of the reinforcing member does not damage the cutting edge of the locking protrusion of the split ring for tightening the pipe, and excellent water pressure resistance can be exhibited.
[0031]
According to the second aspect of the present invention, since the protrusion is provided on the outer surface of the reinforcing member and the protrusion height is 0.3 to 1.5 mm, the reinforcing member can be prevented from coming off from the inside of the resin pipe. The above effect is further certain.
In the present invention as defined in claim 3, the folded portion of the reinforcing member has an end portion of the cylindrical portion folded back in an umbrella shape to form an inclined surface, and the folded surface is provided with an R. The mouth can be smoothly inserted into the receiving port, and the above effect is further ensured.
[Brief description of the drawings]
FIG. 1 is a half longitudinal sectional view showing a first embodiment of a pipe connection structure according to the present invention.
FIG. 2 is a half longitudinal sectional view showing a pipe joint before connection in FIG.
FIG. 3 is a semi-longitudinal sectional view showing a reinforcing member in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pipe joint 2 Joint main body 21 Annular concave groove 22 Inner peripheral surface 23 Inclined groove 3 Split ring 31 for pipe fastening 31 Inclined outer peripheral surface 32 Saw-toothed locking protrusion 4 Seal rubber ring 5, 7 Resin pipe 51 Inlet 6 Reinforcing member 61 Short cylindrical part 62 Folded part 63 Small protrusion

Claims

A rubber ring for sealing is mounted in an annular groove provided on the inner peripheral surface on the opening end side of the joint main body, and the inner peripheral surface of the joint main body located on the back side of the rubber ring faces the rear. An inclined groove having an enlarged diameter is provided. In the inclined groove, a split ring for pipe tightening having an inclined outer peripheral surface substantially coinciding with the inner peripheral surface thereof is provided in a loosely fitted state. In the pipe connection structure in which the outlet of the resin pipe equipped with the cylindrical reinforcing member is inserted and connected,
The outer diameter of the reinforcing member is 97.5 to 99.8% of the inner diameter of the resin pipe outlet, and one end of the reinforcing member is folded outward to form a folded portion. A pipe connection structure characterized in that the outer diameter is 90 to 100% of the outer diameter of the outlet of the resin pipe .

2. The pipe connection structure according to claim 1, wherein a protrusion is provided on the outer surface of the reinforcing member, and the protrusion height is 0.3 to 1.5 mm.

3. The folded portion of the reinforcing member has an inclined surface formed by folding one end portion of the cylindrical portion outward in an umbrella shape, and the folded surface is provided with an R. Pipe connection structure.