JP4354160B2

JP4354160B2 - Double pipe manufacturing method and double pipe welding apparatus

Info

Publication number: JP4354160B2
Application number: JP2002249070A
Authority: JP
Inventors: 充黒澤; 幸二長沢; 力豊原
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2002-08-28
Filing date: 2002-08-28
Publication date: 2009-10-28
Anticipated expiration: 2022-08-28
Also published as: JP2004082191A

Description

【０００１】
【発明の属する技術分野】
本発明は、内管と二重管結合部材を有する内管本体の二重管結合部材によって内管の周りに空隙部を保って外管を溶接接合して二重管を造る二重管の製作方法、及びそのような二重管を製作するため前記内管本体と外管とを溶接接合するための溶接装置に関する。
【０００２】
【従来の技術】
従来、管体と管体とを溶接で接合する場合には、これら管体に仮付け溶接を施した上、それら管体をチャック等で固定し、あるいは、ローラで回転させるとともに管内にシールドガスを送入して管継手における裏波溶接を実施することが考えられている。そのような技術については、特開平０９−２７１９８５号公報「シールドガスを用いる溶接方法およびシールドガス供給装置」、特開平０６−３２０２６８号公報「ステンレス鋼パイプなどの溶接方法と装置」、及び特開平０５−１７７３８９号公報「管溶接装置及び管溶接方法」などに記載されている。
【０００３】
一方、管体を通して液体窒素を流通させる場合、管内を流通する液体窒素を断熱するために、外管と内管との間に空隙部を介在させて構成した二重管が用いられる。
そのような二重管として、図２に示すように、フランジ部４−１を有する内管端部４と、この内管端部４の一端４−２に一端２−１を接合された二重管結合部材２と、この二重管結合部材２の内管接合部２−２に一端３−１が溶接接合された内管３とにより内管本体を構成し、この内管本体を外管１の貫通部１−１に挿入して、二重管結合部材２の外管接合部２−３と外管１の一端１−２とを溶接接合することにより、内管３と外管１との間に空隙部５が設けられた構造とした二重管が用いられる。
【０００４】
この二重管は、例えば、外管１を高張力鋼等、内管端部４と二重管結合部材２と内管３で構成された内管本体をステンレス鋼等で構成しているが、この二重管を製造するために二重管結合部材２の外管接合部２−３と外管１の一端１−２とを溶接接合する場合、外管接合部２−３と外管１の一端１−２とをショートビードによる仮付け溶接を施すと、ショートビードによる仮付け溶接による溶接熱、応力集中等により溶着部又は母材に欠陥等が生ずることとなるため、仮付け溶接を施すことができない、という問題点があった．
そのため、図３の（ａ）に示すように横向姿勢で裏波溶接等を行う際に、仮付け溶接を施すことなく外管接合部２−３と外管１の一端１−２とを溶接接合すると、図３の（ｂ）に示すように溶接による熱収縮により角変形による溶接歪みが生じ、二重管の精度を保持することが困難という問題があった。
【０００５】
【発明が解決しようとする課題】
本発明は、二重管結合部材に内管が接合されて形成された内管本体の前記内管との接合部の周りに空隙部を保って、仮付け溶接を施すことなく、しかも溶接による熱収縮により溶接歪みを生じさせずに、外管を溶接接合して二重管を造る二重管の製作方法、及びそのような二重管を製作するため前記内管本体と外管とを溶接接合するための溶接装置を提供することを課題としている。
【０００６】
【課題を解決するための手段】
本発明は前記課題を解決する二重管の製作方法として、内管と接合される第１の接合部と、同第１の接合部の周りに空隙部を保って外管と接合される第２の接合部と、を具えた二重管結合部材を有する内管本体をつくり、フランジに固定された外管の軸心を通り同フランジに一端が固定されたシャフトを介して前記外管内に前記内管本体を挿入し、同シャフトの他端に、前記内管本体が固定されたフランジを螺子部とナットによって取り付けて、前記外管の端部と前記第２の接合部の開先取り合い面を位置決めし、前記外管と内管本体との間の前記空隙部にシールドガスを送入して前記開先を溶接することを特徴とする二重管の製作方法を提供する。
【０００７】
本発明のこの二重管の製作方法によれば、二重管結合部材を有する内管本体をつくり、フランジに固定された外管の軸心を通るシャフトを介してその外管内にその内管本体を挿入して外管の端部と前記第２の接合部の開先取り合い面を位置決めし、外管と内管本体との間の空隙部にシールドガスを送入して前記開先を溶接することにより、仮付け溶接を施すことなく、しかも溶接による熱収縮により溶接歪みが生じないようフランジと外管の軸心を通るシャフトによって保持しつつ、外管を内管本体に溶接接合して所望どおり二重管を造ることができる。
【０００８】
また、本発明は、前記課題を解決する二重管の溶接装置として、外管を保持する第１のフランジと、前記外管の端部と接合される開先が外周に形成された内管本体を保持する第２のフランジと、前記両フランジの中心軸線上に位置され前記第１のフランジに一端が固定され他端に前記第２のフランジを螺子部とナットによって取り付け前記外管の端部と前記内管本体の開先の取り合い面を位置決めするシャフトと、前記フランジに保持された外管と内管本体を把持するチャックと、同チャックによって把持された外管と内管本体を一体に回転させる回転駆動機構と、前記外管と内管本体との間の空隙にシールドガスを導入する導入管と、を有することを特徴とする二重管の溶接装置を提供する。
【０００９】
本発明のこの二重管の溶接装置によれば、外管と内管本体を、それぞれ、第１と第２のフランジによって保持するとともに両フランジの中心軸線上に位置されたシャフトによって外管と内管本体を同心に位置決めして、前記第１のフランジに保持された外管と内管本体をチャックによって一体に回転させ、かつ、内管本体と外管との間の空隙にシールドガスを導入して外管を内管本体に溶接接合して、所望どおり二重管を造ることができる。
【００１０】
【発明の実施の形態】
以下、本発明を図１に示した実施の形態に基づいて具体的に説明する。
この実施の形態は、図２に示したように、内管端部４、二重管結合部材２、及び内管３とにより構成された内管本体に対し、内管３の周りに空隙部５を保って外管１を溶接して二重管を製造するのに本発明による二重管の溶接装置を適用した場合である。
【００１１】
この二重管において、外管１は高張力鋼等で構成され、内管本体を構成している二重管結合部材２、内管３、及び内管端部４はステンレス鋼等で構成されている。また、内管３とその周りの外管１との間には、空隙部５が形成されている。
【００１２】
この二重管において、内管本体を構成する二重管結合部材２、内管３、及び内管端部４は、既知の溶接手法を適宜利用して接合すべき各端部を溶接接合して組み立てる。その内管本体に対して図１に示す溶接装置を使って図２に示す状態に外管１を溶接接合する。
【００１３】
次に、内管本体に対し外管１を溶接接合するやり方を図１によって説明する。図１において、１５はフランジで、その中心軸線上にシャフト８端部の螺子と係合されてシャフト８を保持する孔部１５−１を設けてある。
１１はフランジで、フランジ１５の端部に位置し、外管１を保持するためのボルト１０を挿入するためのボルト挿入孔部１１−１を有している。
【００１４】
６はフランジで、外管１を位置決め拘束する機能をもつ。すなわち、外管１は、フランジ６、１１、１５を貫通するボルト１０が外管１に設けられた螺子部１−３に螺合することによってフランジ６に固定して位置決めされる。
８はシャフトで、このシャフト８の一端部に螺子部８−１を有しフランジ１５の中心軸線上に設けられた孔部１５−１に螺合して取り付けられている。なお、フランジ１５は本発明にいう第１のフランジに相当する。
【００１５】
シャフト８は外管１と内管本体の軸線を貫通していて、その他端に螺子部８−２を有している。
１６はチャックを示し、チャック１６はフランジ６、１１、１５を介して外管１と内管本体からなる二重管を把持し、図示していない駆動源からの動力で二重管に回転を与える。
【００１６】
７はガス導入管で、二重管の内管本体と外管１との間の空隙部５にＡｒガス等のシールドガスを送入する機能をもつ。
９は調節フランジで、この調節フランジ９はシャフト８の他端に設けられている螺子部８−２に螺合してルートギャップ保持の機能をもつ。調節フランジ９は、内管本体を構成する内管端部４のフランジ部４−１にボルト１２、ナット１３で拘束される。
１４はナットで、ルートギャップ保持用の調節フランジ９の後方に位置してシャフト８の螺子部８−２と螺合する。なお、調節フランジ９は本発明にいう第２のフランジに相当する。
【００１７】
以上説明したように、外管１をフランジ６、１１、１５を貫通するボルト１０によって固定するとともに、シャフト８に内管本体を通してその内管端部４をルートギャップ保持用の調節フランジ９にボルト１２とナット１３によって保持して、外管１の一端１−２と内管本体を構成する二重管結合部材２の外管接合部２−３との開先取り合い面を、ルートギャップ保持用の調節フランジ９後方に位置されたシャフト８の螺子部８−２に螺合するナット１４によって調節して拘束する。なお、上記外管接合部２−３は本発明にいう第２の接合部に相当し、図２の内管接合部２−２が本発明にいう第１の接合部に相当する。
【００１８】
ガス導入管７からＡｒガス等のシールドガスを二重管内の空隙部５に送入して、チャック１６を介して図示していない駆動源で二重管に回転を与えながら二重管結合部材２の外管接合部２−３との開先を下向き裏波溶接する。
【００１９】
こうして、図１の溶接装置によって内管３と外管１との間に空隙部５を介在させた二重管を製作することができ、この二重管は、内管３内に液体窒素を流通させる場合に、内管３と外管１の間の空隙部５が外管１に対する液体窒素等の低温流体の熱影響による不具合を解消することができる。
【００２０】
以上説明したように、図１に示した実施形態によれば、シャフト８を介して外管１内に、内管端部４、二重管結合部材２及び内管３から適宜の溶接接合によって組み立てた内管本体を挿入し、フランジ６に固定された外管１と調節フランジ９に保持された内管本体の二重管結合部材２との開先取り合い面を位置決めして拘束し、仮付溶接を施すことなく二重管内へシールドガスを送入して前記開先を溶接して内管３と外管１との間に空隙部５を形成した二重管を製作することができる。
【００２１】
以上説明した実施形態では、次のような利点をもつ二重管の製作方法及び二重管の製造装置が提供されている。
１）外管１と二重管結合部材２との溶接面を仮付け溶接をすることなく、開先面のルートギャップを自在に設定して健全な溶着金属を得て高品質な溶接をうることができる。
２）仮付け溶接を施すことなく溶接接合する従来のやり方では、熱収縮による溶接歪みが生じて手直し作業が必要であったが、本実施形態によればそのような手直し作業が必要でない。
【００２２】
以上、本発明を実施の形態に基づいて具体的に説明したが、本発明はこの実施形態に限定されるものではなく、特許請求の範囲に示す本発明の範囲内で種々の変形、変更を加えてよいことはいうまでもない。
【００２３】
例えば、本発明による二重管の製作方法は、図１に示した実施形態による溶接装置以外、適宜の装置を使って実施してよい。
【００２４】
また、この実施形態では外管１及び内管本体をフランジ６、９に取付けるのにボルト１０、１２を用いているが、ボルトによる取り付けに代え、クランプ等、他の適宜の取り付け機構によってもよい。
【００２５】
更にまた、図示した実施形態では、内管本体が内管端部４、二重管結合部材２及び内管３の３つの部材から構成されるものとしているが、３つの部材から構成することは不可欠ではなく、要は、内管との接合部を有するとともに内管との接合部の周りに空隙部を保って外管との接合部を具えた二重管結合部材を有する内管本体であればよく、その内管本体の二重管結合部材によって内管と外管を、両者の間に空隙部を形成して溶接接合するようにした構造であればよい。
【００２６】
【発明の効果】
以上説明したように、本発明は、内管と接合される第１の接合部と、同第１の接合部の周りに空隙部を保って外管と接合される第２の接合部と、を具えた二重管結合部材を有する内管本体をつくり、フランジに固定された外管の軸心を通り同フランジに一端が固定されたシャフトを介して前記外管内に前記内管本体を挿入し、同シャフトの他端に、前記内管本体が固定されたフランジを螺子部とナットによって取り付けて、前記外管の端部と前記第２の接合部の開先取り合い面を位置決めし、前記外管と内管本体との間の前記空隙部にシールドガスを送入して前記開先を溶接する二重管の製作方法を提供する。
【００２７】
本発明のこの二重管の製作方法によれば、二重管結合部材を有する内管本体を適宜組み立ててつくり、フランジに固定された外管の軸心を通るシャフトを介して該外管内にその内管本体を挿入して外管の端部と二重管結合部材の第２の接合部の開先取り合い面を位置決めし、外管と内管本体との間の空隙部にシールドガスを送入して前記開先を溶接することにより、仮付け溶接を施すことなく、外管を内管本体に溶接接合して所望どおり二重管を造ることができる。
【００２８】
また、本発明は、外管を保持する第１のフランジと、前記外管の端部と接合される開先が外周に形成された内管本体を保持する第２のフランジと、前記両フランジの中心軸線上に位置され前記第１のフランジに一端が固定され他端に前記第２のフランジを螺子部とナットによって取り付け前記外管の端部と前記内管本体の開先の取り合い面を位置決めするシャフトと、前記フランジに保持された外管と内管本体を把持するチャックと、同チャックによって把持された外管と内管本体を一体に回転させる回転駆動機構と、前記外管と内管本体との間の空隙にシールドガスを導入する導入管と、を有する二重管の溶接装置を提供する。
【００２９】
本発明の二重管の溶接装置によれば、外管と内管本体を、それぞれ、第１と第２のフランジによって保持するとともに両フランジの中心軸線上に位置されたシャフトによって外管と内管本体を同心に位置決めして、前記第１のフランジに保持された外管と内管本体をチャックによって一体に回転させ、かつ、内管本体と外管との間の空隙にシールドガスを導入して外管を内管本体に溶接接合して、所望どおり二重管を造ることができる。
【図面の簡単な説明】
【図１】本発明の実施の一形態による二重管の溶接装置を用いて内管本体と外管とを溶接接合して二重管を製作している状態を示す断面図。
【図２】本発明を適用して内管本体と外管を溶接接合して製造される二重管の例を示す断面図。
【図３】図２に示すように内管本体と外管を溶接接合して二重管を製造する従来のやり方を説明する断面図で、（ａ）は横向姿勢で仮付け溶接無しで裏波溶接を行う場合を示し、（ｂ）は溶接による熱収縮で角変形を生じた状態を示している。
【符号の説明】
１外管
１−１外管の貫通部
１−２外管の一端
１−３外管の螺子部
２二重管結合部材
２−１二重管結合部材の一端
２−２内管接合部（第１の接合部）
２−３外管接合部（第２の接合部）
３内管
３−１内管の一端
４内管端部
４−１フランジ
４−２内管端部の一端
５空隙部
６フランジ
７ガス導入管
８シャフト
８−１シャフトの螺子部
８−２シャフトの螺子部
９フランジ（第２のフランジ）
１０ボルト
１１フランジ
１１−１ボルト挿入孔部
１２ボルト
１３ナット
１４ナット
１５フランジ（第１のフランジ）
１５−１孔部
１６チャック[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a double pipe in which a double pipe is formed by welding and joining an outer pipe while maintaining a void around the inner pipe by a double pipe coupling member of an inner pipe body having an inner pipe and a double pipe coupling member. The present invention relates to a manufacturing method and a welding apparatus for welding and joining the inner tube main body and the outer tube in order to manufacture such a double tube.
[0002]
[Prior art]
Conventionally, when joining pipes to each other by welding, these pipes are tack-welded, and the pipes are fixed with a chuck or the like, or rotated with a roller and shield gas is put into the pipes. It is considered that reverse wave welding is performed on pipe joints. For such techniques, Japanese Patent Application Laid-Open No. 09-271985 “Welding Method Using Shielding Gas and Shielding Gas Supply Device”, Japanese Patent Application Laid-Open No. 06-320268 “Welding Method and Device for Stainless Steel Pipes”, No. 05-177389, “Pipe Welding Apparatus and Pipe Welding Method”.
[0003]
On the other hand, when liquid nitrogen is circulated through the tube body, a double tube configured by interposing a gap between the outer tube and the inner tube is used to insulate the liquid nitrogen flowing through the tube.
As such a double pipe, as shown in FIG. 2, an inner pipe end portion 4 having a flange portion 4-1 and an end 2-1 joined to one end 4-2 of the inner pipe end portion 4. The inner pipe body is constituted by the heavy pipe coupling member 2 and the inner pipe 3 in which one end 3-1 is welded to the inner pipe joint portion 2-2 of the double pipe coupling member 2, and the inner pipe body is The inner pipe 3 and the outer pipe are inserted into the penetration part 1-1 of the pipe 1 and the outer pipe joining part 2-3 of the double pipe coupling member 2 and the one end 1-2 of the outer pipe 1 are welded. A double pipe having a structure in which a gap portion 5 is provided between the first and second gaps is used.
[0004]
In this double pipe, for example, the outer pipe 1 is made of high-strength steel or the like, and the inner pipe body made up of the inner pipe end 4, the double pipe coupling member 2 and the inner pipe 3 is made of stainless steel or the like. In order to manufacture this double pipe, when the outer pipe joint 2-3 of the double pipe coupling member 2 and the one end 1-2 of the outer pipe 1 are welded, the outer pipe joint 2-3 and the outer pipe When one end 1-2 of 1 is tack-welded with a short bead, welding heat or stress concentration due to tack-welding with a short bead will cause defects in the welded part or the base metal. There was a problem that could not be applied.
Therefore, as shown in FIG. 3A, when performing reverse wave welding or the like in the horizontal orientation, the outer pipe joint 2-3 and the one end 1-2 of the outer pipe 1 are welded without performing tack welding. When joined, as shown in FIG. 3B, there is a problem that welding distortion due to angular deformation occurs due to heat shrinkage due to welding, and it is difficult to maintain the accuracy of the double pipe.
[0005]
[Problems to be solved by the invention]
The present invention maintains a gap around the joint portion of the inner tube main body formed by joining the inner tube to the double tube coupling member, and does not perform temporary welding, but also by welding. A method of manufacturing a double pipe in which the outer pipe is welded and joined to produce a double pipe without causing welding distortion due to heat shrinkage, and the inner pipe body and the outer pipe are combined to manufacture such a double pipe. It is an object of the present invention to provide a welding apparatus for welding and joining.
[0006]
[Means for Solving the Problems]
The present invention provides a method of manufacturing a double pipe that solves the above-mentioned problems . A first joint that is joined to the inner pipe, and a first joint that is joined to the outer pipe while maintaining a gap around the first joint . creating an inner tube body with a double pipe coupling member equipped with second joining portion, the outer tube end the axis of the outer tube fixed to the flange through Ri same flange via a fixed shaft in inserting the inner tube body, the other end of the shaft, a flange within the tube body is fixed by attaching the screw portion and the nut, groove between the end portion of the outer tube and the second junction Provided is a method of manufacturing a double pipe, wherein a mating surface is positioned, a shield gas is fed into the gap between the outer pipe and the inner pipe main body, and the groove is welded.
[0007]
According to this method of manufacturing a double pipe of the present invention, an inner pipe body having a double pipe coupling member is formed, and the inner pipe is inserted into the outer pipe via a shaft passing through the axis of the outer pipe fixed to the flange. The main body is inserted to position the end of the outer tube and the groove joining surface of the second joint, and a shield gas is fed into the gap between the outer tube and the inner tube main body to By welding, the outer pipe is welded and joined to the inner pipe body while holding it by the shaft passing through the flange and the axis of the outer pipe so that welding distortion does not occur due to thermal shrinkage caused by welding. Double pipes can be made as desired.
[0008]
In addition, the present invention provides a double pipe welding apparatus that solves the above-described problems, and a first flange that holds the outer pipe, and an inner pipe having a groove joined to the end of the outer pipe formed on the outer periphery. A second flange for holding the main body; one end fixed to the first flange located on the center axis of the two flanges, and the second flange attached to the other end by a screw portion and a nut; the end of the outer tube A shaft for positioning the joint surface of the groove of the inner portion and the inner tube body, an outer tube held by the flange and a chuck for holding the inner tube body, and an outer tube and an inner tube body held by the chuck are integrated. A double pipe welding apparatus comprising: a rotary drive mechanism for rotating the first pipe; and an introduction pipe for introducing a shielding gas into a gap between the outer pipe and the inner pipe main body.
[0009]
According to this double pipe welding apparatus of the present invention, the outer pipe and the inner pipe main body are held by the first and second flanges, respectively, and the outer pipe and the outer pipe are supported by the shaft positioned on the center axis of both flanges. The inner pipe main body is positioned concentrically, the outer pipe and the inner pipe main body held by the first flange are rotated together by a chuck, and a shielding gas is introduced into the gap between the inner pipe main body and the outer pipe. Once introduced, the outer tube can be welded to the inner tube body to create a double tube as desired.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described based on the embodiment shown in FIG.
In this embodiment, as shown in FIG. 2, the inner tube body constituted by the inner tube end portion 4, the double tube coupling member 2, and the inner tube 3 has a gap portion around the inner tube 3. This is a case where the double pipe welding apparatus according to the present invention is applied to manufacture a double pipe by welding the outer pipe 1 while maintaining 5.
[0011]
In this double pipe, the outer pipe 1 is made of high tensile steel or the like, and the double pipe coupling member 2, the inner pipe 3 and the inner pipe end 4 constituting the inner pipe body are made of stainless steel or the like. ing. Further, a gap 5 is formed between the inner tube 3 and the outer tube 1 around it.
[0012]
In this double pipe, the double pipe coupling member 2, the inner pipe 3, and the inner pipe end 4 constituting the inner pipe main body are welded to each end to be joined by appropriately using a known welding technique. And assemble. The outer pipe 1 is welded to the inner pipe main body in the state shown in FIG. 2 using the welding apparatus shown in FIG.
[0013]
Next, a manner of welding and joining the outer pipe 1 to the inner pipe main body will be described with reference to FIG. In FIG. 1, reference numeral 15 denotes a flange, which is provided with a hole 15-1 that holds the shaft 8 by being engaged with a screw at the end of the shaft 8 on the center axis.
Reference numeral 11 denotes a flange, which is located at an end of the flange 15 and has a bolt insertion hole portion 11-1 for inserting a bolt 10 for holding the outer tube 1.
[0014]
A flange 6 has a function of restraining positioning of the outer tube 1. That is, the outer tube 1 is positioned by being fixed to the flange 6 by screwing a bolt 10 penetrating the flanges 6, 11, 15 into a screw part 1-3 provided in the outer tube 1.
Reference numeral 8 denotes a shaft, which has a screw portion 8-1 at one end portion of the shaft 8 and is screwed into a hole portion 15-1 provided on the central axis of the flange 15. The flange 15 corresponds to the first flange according to the present invention.
[0015]
The shaft 8 penetrates the axis of the outer tube 1 and the inner tube main body, and has a screw portion 8-2 at the other end.
Reference numeral 16 denotes a chuck. The chuck 16 grips the double pipe composed of the outer pipe 1 and the inner pipe main body through the flanges 6, 11, and 15, and rotates to the double pipe by power from a drive source (not shown). give.
[0016]
A gas introduction pipe 7 has a function of feeding a shielding gas such as Ar gas into the gap 5 between the inner pipe body of the double pipe and the outer pipe 1.
Reference numeral 9 denotes an adjustment flange. The adjustment flange 9 is screwed into a screw portion 8-2 provided at the other end of the shaft 8 and has a function of holding a root gap. The adjustment flange 9 is restrained by a bolt 12 and a nut 13 on the flange portion 4-1 of the inner tube end 4 constituting the inner tube main body.
A nut 14 is positioned behind the adjustment flange 9 for maintaining the root gap and is screwed with the screw portion 8-2 of the shaft 8. The adjustment flange 9 corresponds to a second flange according to the present invention.
[0017]
As described above, the outer tube 1 is fixed by the bolt 10 that penetrates the flanges 6, 11, 15, and the inner tube end 4 is passed through the shaft 8 to the adjustment flange 9 for maintaining the root gap. 12 and the nut 13, the groove connecting surface between the end 1-2 of the outer pipe 1 and the outer pipe joint 2-3 of the double pipe coupling member 2 constituting the inner pipe main body is used for holding the root gap. The adjustment flange 9 is adjusted and restrained by a nut 14 screwed into the screw portion 8-2 of the shaft 8 positioned behind the adjustment flange 9. The outer tube joint 2-3 corresponds to the second joint according to the present invention, and the inner tube joint 2-2 of FIG. 2 corresponds to the first joint according to the present invention.
[0018]
Shield gas such as Ar gas is fed from the gas introduction pipe 7 into the gap 5 in the double pipe, and the double pipe coupling member is rotated through the chuck 16 with a driving source (not shown) while rotating the double pipe. The groove with the outer pipe joint 2-3 of 2 is welded downward and reverse wave.
[0019]
In this way, a double pipe in which the gap 5 is interposed between the inner pipe 3 and the outer pipe 1 can be manufactured by the welding apparatus of FIG. In the case of circulation, the gap 5 between the inner tube 3 and the outer tube 1 can eliminate problems caused by the thermal influence of a low-temperature fluid such as liquid nitrogen on the outer tube 1.
[0020]
As described above, according to the embodiment shown in FIG. 1, the inner pipe end 4, the double pipe coupling member 2, and the inner pipe 3 are appropriately welded to the outer pipe 1 through the shaft 8. The assembled inner pipe main body is inserted, and the groove connecting surface between the outer pipe 1 fixed to the flange 6 and the double pipe coupling member 2 of the inner pipe main body held by the adjusting flange 9 is positioned and restrained. A double pipe in which a gap portion 5 is formed between the inner pipe 3 and the outer pipe 1 can be manufactured by feeding shield gas into the double pipe without welding and welding the groove. .
[0021]
In the embodiment described above, a double pipe manufacturing method and a double pipe manufacturing apparatus having the following advantages are provided.
1) Without welding the welding surface of the outer pipe 1 and the double pipe coupling member 2, the root gap of the groove surface can be freely set to obtain a sound weld metal and obtain high quality welding. be able to.
2) In the conventional method of welding and joining without performing tack welding, welding distortion occurs due to heat shrinkage and a reworking operation is necessary. However, according to the present embodiment, such a reworking operation is not necessary.
[0022]
Although the present invention has been specifically described above based on the embodiment, the present invention is not limited to this embodiment, and various modifications and changes can be made within the scope of the present invention shown in the claims. Needless to say, it may be added.
[0023]
For example, the method for manufacturing a double pipe according to the present invention may be performed using an appropriate apparatus other than the welding apparatus according to the embodiment shown in FIG.
[0024]
In this embodiment, the bolts 10 and 12 are used to attach the outer tube 1 and the inner tube main body to the flanges 6 and 9. However, instead of using bolts, other appropriate attachment mechanisms such as clamps may be used. .
[0025]
Furthermore, in the illustrated embodiment, the inner tube main body is composed of three members, that is, the inner tube end portion 4, the double tube coupling member 2, and the inner tube 3. It is not essential, but the main point is an inner pipe body having a double pipe coupling member having a joint with the inner pipe and having a joint with the outer pipe while maintaining a gap around the joint with the inner pipe. Any structure may be used as long as the inner pipe and the outer pipe are welded together by forming a gap portion between the inner pipe and the outer pipe by the double pipe coupling member of the inner pipe main body.
[0026]
【The invention's effect】
As described above, the present invention includes a first bonding portion that is bonded to the inner tube, and a second joint portion to be joined to the outer tube while maintaining a gap portion around the same first junction, creating an inner tube body with a double pipe coupling member equipped with, said inner tube body to the outer tube via a shaft whose one end is fixed the axis of the outer tube which is fixed to the flange through Ri in the flange inserting the other end of the shaft, a flange within the tube body is fixed by attaching the screw portion and a nut, positioning the GMA scramble surface of the end portion of the outer tube and the second joint portion, Provided is a method of manufacturing a double pipe in which a shield gas is fed into the gap between the outer pipe and the inner pipe main body and the groove is welded.
[0027]
According to the method for manufacturing a double pipe of the present invention, an inner pipe body having a double pipe coupling member is appropriately assembled and formed in the outer pipe via a shaft passing through the axis of the outer pipe fixed to the flange. The inner pipe body is inserted, the end of the outer pipe and the groove joint surface of the second joint portion of the double pipe coupling member are positioned, and a shielding gas is put into the gap between the outer pipe and the inner pipe body. By feeding and welding the groove, it is possible to make a double pipe as desired by welding the outer pipe to the inner pipe main body without performing tack welding.
[0028]
Further, the present invention includes a second flange for holding the first flange to hold the outer tube, the inner tube body GMA to be joined to the end portion of the outer tube is formed on the outer periphery, said flanges One end of the first flange is fixed to the first flange and the second flange is attached to the other end with a screw portion and a nut, and an end face of the outer tube and a joint surface of the groove of the inner tube main body are attached. A shaft for positioning, a chuck for holding the outer tube and the inner tube main body held by the flange, a rotation driving mechanism for integrally rotating the outer tube and the inner tube main body held by the chuck, and the outer tube and the inner tube Provided is a double pipe welding device having an introduction pipe for introducing a shielding gas into a gap between the pipe body.
[0029]
According to the double pipe welding apparatus of the present invention, the outer pipe and the inner pipe main body are held by the first and second flanges, respectively, and the outer pipe and the inner pipe are supported by the shaft positioned on the center axis of both flanges. The tube body is positioned concentrically, the outer tube and the inner tube body held by the first flange are rotated together by a chuck, and a shielding gas is introduced into the gap between the inner tube body and the outer tube. Then, the outer pipe can be welded to the inner pipe main body to make a double pipe as desired.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state in which a double pipe is manufactured by welding and joining an inner pipe main body and an outer pipe using a double pipe welding apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an example of a double pipe manufactured by welding and joining an inner pipe main body and an outer pipe by applying the present invention.
FIG. 3 is a cross-sectional view for explaining a conventional method of manufacturing a double pipe by welding and joining an inner pipe body and an outer pipe as shown in FIG. The case where wave welding is performed is shown, and (b) shows a state in which angular deformation is caused by heat shrinkage due to welding.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outer pipe 1-1 Outer pipe penetration part 1-2 One end of outer pipe 1-3 Screw part 2 of outer pipe Double pipe coupling member 2-1 One end 2-2 of double pipe coupling member Inner pipe joint ( First joint)
2-3 Outer pipe joint (second joint)
3 Inner tube 3-1 One end of inner tube 4 Inner tube end 4-1 Flange 4-2 One end of inner tube end 5 Gap 6 Flange 7 Gas introduction tube 8 Shaft 8-1 Screw portion of shaft 8-2 Shaft Screw part 9 flange (second flange)
10 bolt 11 flange 11-1 bolt insertion hole 12 bolt 13 nut 14 nut 15 flange (first flange)
15-1 Hole 16 Chuck

Claims

A double pipe coupling member comprising a first joint joined to the inner pipe and a second joint joined to the outer pipe while maintaining a gap around the first joint. An inner pipe body is made, and the inner pipe body is inserted into the outer pipe through a shaft having one end fixed to the flange passing through the axis of the outer pipe fixed to the flange and the other end having a screw portion. , the other end of the shaft, a flange within the tube body is fixed attached by screwing said screw portion and the nut, GMA scramble the end of the outer tube and the second junction A method of manufacturing a double pipe, wherein a surface is positioned, a shield gas is fed into the gap between the outer pipe and the inner pipe main body, and the groove is welded.

A first flange for holding an outer pipe, a second flange for holding an inner pipe body in which a groove joined to an end of the outer pipe is formed on the outer periphery, and a position on the central axis of the two flanges to one end to the first flange screw portion is provided at the other end is fixed, the inner tube body and the end portion of the attachment the outer tube by causing said second flange screwed with the screw portion and the nut A shaft for positioning the joint surface of the groove, a chuck for gripping the outer tube and the inner tube body held by the flange, and a rotation drive mechanism for integrally rotating the outer tube and the inner tube body held by the chuck And an introduction pipe for introducing a shielding gas into a gap between the outer pipe and the inner pipe main body.