JP2000107858A - Welded structure of pipe jointing part and welding method thereof - Google Patents
Welded structure of pipe jointing part and welding method thereofInfo
- Publication number
- JP2000107858A JP2000107858A JP28377098A JP28377098A JP2000107858A JP 2000107858 A JP2000107858 A JP 2000107858A JP 28377098 A JP28377098 A JP 28377098A JP 28377098 A JP28377098 A JP 28377098A JP 2000107858 A JP2000107858 A JP 2000107858A
- Authority
- JP
- Japan
- Prior art keywords
- welding
- pipe
- branch pipe
- main pipe
- main
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Butt Welding And Welding Of Specific Article (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は金属あるいは合金材
料からなる管と管を溶接接合する管継手部の溶接構造に
係り、特にボイラ、化学プラント等、高温あるいは高圧
の条件下で使用される大径厚肉管の溶接接合に好適な管
継手部の溶接構造およびその溶接方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welded structure of a pipe joint for welding a pipe made of a metal or an alloy material to a pipe, and particularly to a large-sized pipe used in a high temperature or high pressure condition such as a boiler or a chemical plant. The present invention relates to a welded structure of a pipe joint suitable for welding a thick pipe and a method of welding the same.
【０００２】[0002]
【従来の技術】発電用ボイラや各種熱交換器等において
は、多数の伝熱管群および伝熱管を集合する管寄せと連
絡配管などが高温、高圧の条件下で使用されている。図
９は、ボイラ過熱器の管寄せ回りの構造の一例を示す。
管寄せ５には数十列の伝熱管６と、さらに、これらの伝
熱管群から集合した蒸気を、後流側の機器へ送るための
連絡管７が接合されている。特に、管寄せ５や連絡管７
は、大きなものでは８０〜１２０ｍｍもの厚さになる
が、管と管の接合は溶接によって行われるので、これら
の厚肉大径管の溶接部は、製品の品質上重要な部位とな
る。近年、発電用ボイラは大型化し、また蒸気条件も高
温、高圧化しつつあるため管の肉厚は、さらに増加する
傾向にあり、厚肉大径管の溶接部の信頼性は、ますます
重要視されるようになってきている。図１０（ａ）、
（ｂ）は、図９の管寄せ５に相当する主管１と、それよ
りもやや径の小さい枝管２（図９の連絡管７に相当）と
の溶接構造を示す従来技術の一例であって、最も簡単な
構造であり、広く一般に用いられているものである。通
常の場合、主管１に、枝管２の内径と等しい径の穴を加
工し、また、枝管２の先端の一部を加工して開先面３を
形成し、主管１と枝管２を直角に突き合わせて、枝管２
の周囲から溶接する。なお、溶接トーチ９は、図中の
（イ）で示す方向に上下移動し、（ロ）で示す方向に回
転し、かつ（ハ）で示す方向に揺動する。溶接後の接合
状況を図１１に示す。この場合、枝管２の開先先端は、
主管１の穴縁に沿った立体的な形状となるため、開先加
工には３軸制御の高級な加工機械を必要とする問題があ
る。開先加工を容易に行うために、ガス切断法を用いる
方法（特開昭６１−７０６５号公報）も提案されている
が、やはり３軸または４軸制御のマニピュレータが必要
となり、より簡易な開先加工法が望まれている。さら
に、高温配管に用いられる配管材料自身は、通常、製管
後に、焼準し−焼戻し等の熱処理を施してミクロ組織を
調整しているのに対し、溶接金属４は凝固組織のままの
不均質な状態で使用されるので、微小なブローホールや
介在物等の欠陥が残存する可能性がある。このことから
溶接部は強度的に弱点部位となるものであり、特に、図
９〜１１のような一般的な従来技術による構造の場合に
は、溶接金属４の量が多くなる上、溶接作業の難しい水
平姿勢での溶接作業となるため溶接欠陥が生じ易く、高
温、高圧での運転中に溶接部で亀裂が発生し、内部流体
がリークする危険性が高いという問題がある。厚肉大径
管の溶接方法に関しては、例えば、特開平６−４７５３
７号公報、特公昭６２−５８８２６号公報、特開平１−
４２７９５号公報、その他多くの発明、考案がなされて
いる。しかし、これらの発明、考案のほとんどは、多軸
マニピュレータやコンピュータを利用して溶接トーチを
制御するなど、溶接作業を高度に自動化する方法に関す
るものであって、上記のような開先加工の問題や冶金的
な問題は全く考慮されていない。また、溶接姿勢につい
ても水平に近いものが主体で、溶接時の作業性の問題は
本質的には解決されていなかった。2. Description of the Related Art In a boiler for power generation, various heat exchangers, etc., a large number of heat transfer tube groups and headers and connecting pipes for collecting the heat transfer tubes are used under high temperature and high pressure conditions. FIG. 9 shows an example of a structure around a tube of a boiler superheater.
The header 5 is joined with several tens of rows of heat transfer tubes 6, and further, a connecting tube 7 for sending the steam collected from these heat transfer tube groups to downstream equipment. In particular, header 5 and connecting pipe 7
Although the thickness of a large pipe is as large as 80 to 120 mm, since the pipes are joined by welding, the welded portions of these thick large-diameter pipes are important parts in terms of product quality. In recent years, boilers for power generation have become larger, and steam conditions have been increasing at high temperatures and pressures, so the wall thickness of the pipes has tended to increase further, and the reliability of the welds of thick-walled large-diameter pipes has become increasingly important. It is becoming. FIG. 10 (a),
(B) is an example of a prior art showing a welding structure of a main pipe 1 corresponding to the header 5 in FIG. 9 and a branch pipe 2 having a slightly smaller diameter (corresponding to the connecting pipe 7 in FIG. 9). Therefore, it is the simplest structure and widely used. In a normal case, a hole having a diameter equal to the inner diameter of the branch pipe 2 is formed in the main pipe 1, and a part of the tip of the branch pipe 2 is processed to form a groove surface 3. At right angles and branch tube 2
Weld from around. The welding torch 9 moves up and down in the direction indicated by (a) in the figure, rotates in the direction indicated by (b), and swings in the direction indicated by (c). FIG. 11 shows the joining state after welding. In this case, the tip of the groove of the branch pipe 2 is
Since it has a three-dimensional shape along the hole edge of the main pipe 1, there is a problem that a high-quality three-axis control processing machine is required for beveling. A method using a gas cutting method (Japanese Patent Laid-Open Publication No. Sho 61-7065) has been proposed to facilitate groove preparation. However, a three-axis or four-axis control manipulator is required, and a simpler opening operation is required. A pre-processing method is desired. Further, the pipe material itself used for the high-temperature pipe is usually subjected to a heat treatment such as normalizing and tempering to form a microstructure after the pipe is made, while the weld metal 4 is not solidified. Since it is used in a homogeneous state, defects such as minute blow holes and inclusions may remain. For this reason, the welded portion is a weak point portion in terms of strength. Particularly, in the case of a structure according to a general conventional technique as shown in FIGS. 9 to 11, the amount of the weld metal 4 increases and the welding work is performed. Since the welding operation is performed in a horizontal position that is difficult to perform, there is a problem that a welding defect is easily generated, a crack is generated in a welded portion during operation at a high temperature and a high pressure, and there is a high risk that an internal fluid leaks. Regarding a method for welding a thick-walled large-diameter pipe, for example, Japanese Unexamined Patent Publication No.
7, Japanese Patent Publication No. 62-58826,
No. 42795, and many other inventions and inventions have been made. However, most of these inventions and inventions are related to a method of automating welding work, such as controlling a welding torch using a multi-axis manipulator or a computer. And metallurgical issues are not considered at all. In addition, the welding posture is mainly horizontal, and the problem of workability during welding has not been essentially solved.
【０００３】[0003]
【発明が解決しようとする課題】本発明の目的は、上述
した従来技術における開先加工が複雑で高価となる点、
溶接姿勢が水平となるため溶接欠陥が生じ易いという
点、および溶接金属の量が多くなり強度的に弱い溶接部
が大きくなる点などの問題点を解消し、通常用いられて
いる一般的な加工機械で容易に開先加工を行うことがで
き、かつ溶接作業性を改善し、溶接金属の量も少なくす
ることによって信頼性の高い溶接部を有する管継手部の
溶接構造およびその溶接方法を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to make the groove forming in the prior art described above complicated and expensive.
General processing that is normally used to solve problems such as the fact that welding defects are likely to occur because the welding position is horizontal, and that the amount of weld metal increases and the strength of weakly welded parts increases. Provided is a welded structure of a pipe joint having a highly reliable welded portion, which can be easily grooved by a machine, improves welding workability, and reduces the amount of weld metal, and a method for welding the same. Is to do.
【０００４】[0004]
【課題を解決するための手段】上記本発明の目的を達成
するために、特許請求の範囲に記載のような構成とする
ものである。すなわち、本発明は請求項１に記載のよう
に、主管に枝管が交差する管継手部の溶接構造であっ
て、上記主管に、上記枝管の外径よりもやや大きい径の
穴を開け、該主管の穴部に、溶接接合する枝管の端部を
挿入して、上記主管の穴の内面と上記枝管の端部の外周
面との間の隙間部に溶接開先を形成し、該溶接開先内に
溶接トーチの先端部を挿入して、下向き姿勢で溶接トー
チの先端部を枝管の外周方向および上下方向に移動させ
ながら溶接した管継手部の溶接構造とするものである。
このように、主管と枝管の溶接開先を簡易な機械加工に
より作製することができ、かつ、下向き姿勢で狭開先溶
接を自動的に行うことができるので、溶接欠陥が少なく
溶接金属の量を低減した信頼性の高い管継手の溶接部を
安価に作製できる効果がある。また、本発明は請求項２
に記載のように、請求項１に記載の管継手部の溶接構造
において、主管に開ける枝管の外径よりもやや大きい穴
径（Ｄ）は、Ｄ＝｛（枝管の外径）＋２×（開先幅）｝
ｍｍとする管継手部の溶接構造である。このように、溶
接開先の形状を具体的に設定することにより、溶接欠陥
が少なく溶接金属の量を低減した信頼性の高い管継手の
溶接部を安定して作製できる効果がある。また、本発明
は請求項３に記載のように、請求項１に記載の管継手部
の溶接構造において、主管の穴の内面と枝管の端部の外
周面との間に形成される溶接開先の下部に、初層を溶接
する際に用いる主管の外面側から当て金を装着するか、
もしくは丸棒状または角棒状の金属製インサートリング
を上記溶接開先の下部に挿着した管継手部の溶接構造と
するものである。このように、当て金の装着あるいはイ
ンサートリングの挿入をすることにより、溶接欠陥の少
ない溶接部を安定して作製できる効果がある。また、本
発明は請求項４に記載のように、請求項１ないし請求項
３のいずれか１項に記載の管継手部の溶接構造を作製す
る溶接方法であって、枝管が主管の下側となるように配
置し、上記主管の内面側から下向き姿勢で溶接を行う管
継手部の溶接方法とするものである。このような溶接方
法とすることにより、下向き姿勢で自動的に狭開先溶接
を行うことができ、溶接欠陥の少ない信頼性の高い溶接
部を容易に得られる効果がある。また、本発明は請求項
５に記載のように、請求項１ないし請求項３のいずれか
１項に記載の管継手部の溶接構造を作製する溶接方法で
あって、枝管が主管の上側となるように配置し、主管の
外面側から下向き姿勢で溶接を行う管継手部の溶接方法
とするものである。このような溶接方法とすることによ
り、下向き姿勢で自動的に狭開先溶接を行うことがで
き、溶接欠陥の少ない信頼性の高い溶接部を容易に得ら
れる効果がある。また、本発明は請求項６に記載のよう
に、請求項１ないし請求項３のいずれか１項に記載の管
継手部の溶接構造を作製する溶接方法であって、枝管の
管軸を中心に回転する回転台上に溶接トーチを保持し、
該溶接トーチを枝管の管軸中心の円周上に沿って回転さ
せながら上下方向に動かすことにより溶接を行う管継手
部の溶接方法とするものである。このような溶接方法と
することにより、簡易な自動装置を用いるだけで、管継
手部の自動溶接化を達成できる効果がある。また、本発
明は請求項７に記載のように、請求項１ないし請求項３
のいずれか１項に記載の管継手部の溶接構造を作製する
溶接方法であって、枝管の管軸と一致する軸を枝管の内
部に挿入し、該軸に溶接トーチを保持して、該溶接トー
チを枝管の管軸中心の円周上に沿って回転させながら上
下方向に動かすことにより溶接を行う管継手部の溶接方
法とするものである。このような溶接方法とすることに
より、上記請求項６と同様に、簡易な自動装置を用いる
だけで、容易に管継手部の自動溶接化を達成できる効果
がある。本発明の管継手部の溶接構造は、主管の側面に
枝管の外径よりもやや大きい径の穴を開け、該穴に、溶
接する枝管の端部を挿入して、枝管が主管の下側になる
ように配置し、主管の内面側から狭開先溶接を行うか、
あるいは枝管が主管の上側になるように配置し、主管の
外側から狭開先溶接を行うことにより実現できる。そし
て、高価で特別な加工技術を用いて溶接開先を加工する
必要がないうえ、溶接線（溶接ライン）は、溶接部の全
周にわたって下向き姿勢で溶接できるため、溶接の作業
性が良く、下向き溶接であるため溶接欠陥を生じる問題
点はほとんどなくなり、また、狭開先溶接法であるため
溶接金属の量を、従来の水平姿勢の溶接法に比べて大幅
に低減することができ、溶接欠陥の少ない信頼性の高い
管継手の溶接構造を実現することができる。Means for Solving the Problems In order to achieve the above object of the present invention, the present invention is configured as described in the claims. That is, the present invention provides a welded structure of a pipe joint portion in which a branch pipe intersects a main pipe, wherein a hole having a diameter slightly larger than an outer diameter of the branch pipe is formed in the main pipe. Inserting the end of the branch pipe to be welded into the hole of the main pipe to form a welding groove in a gap between the inner surface of the hole of the main pipe and the outer peripheral surface of the end of the branch pipe. A welding structure of a pipe joint portion welded by inserting a tip of a welding torch into the welding groove and moving the tip of the welding torch in a downward position in an outer circumferential direction and a vertical direction of a branch pipe. is there.
In this way, the welding groove of the main pipe and the branch pipe can be manufactured by simple machining, and the narrow groove welding can be automatically performed in the downward position, so that there are few welding defects and the welding metal can be welded. There is an effect that a welded portion of a pipe joint having a reduced amount and high reliability can be manufactured at low cost. Further, the present invention provides a second aspect
In the pipe joint welded structure according to claim 1, the hole diameter (D) slightly larger than the outer diameter of the branch pipe opened in the main pipe is D = ｛(outer diameter of branch pipe) +2. × (groove width)｝
It is a welded structure of the pipe joint part which is set to mm. In this way, by setting the shape of the welding groove specifically, there is an effect that a reliable welded portion of a pipe joint having few welding defects and a reduced amount of weld metal can be stably manufactured. According to a third aspect of the present invention, in the welded structure for a pipe joint according to the first aspect, a weld formed between the inner surface of the hole of the main pipe and the outer peripheral surface of the end of the branch pipe. At the bottom of the groove, attach a metal plate from the outer surface side of the main pipe used when welding the first layer,
Alternatively, a pipe-joint portion having a round or square bar-shaped metal insert ring is inserted into a lower portion of the welding groove. As described above, by attaching the backing plate or inserting the insert ring, there is an effect that a welded portion having few welding defects can be stably manufactured. According to a fourth aspect of the present invention, there is provided a welding method for producing a welded structure for a pipe joint according to any one of the first to third aspects, wherein the branch pipe is located below the main pipe. And a method of welding a pipe joint portion in which welding is performed in a downward position from the inner surface side of the main pipe. By adopting such a welding method, narrow groove welding can be automatically performed in a downward posture, and there is an effect that a highly reliable weld having few welding defects can be easily obtained. According to a fifth aspect of the present invention, there is provided a welding method for producing a welded structure for a pipe joint according to any one of the first to third aspects, wherein the branch pipe is located above the main pipe. And a welding method for a pipe joint portion in which welding is performed in a downward position from the outer surface side of the main pipe. By adopting such a welding method, narrow groove welding can be automatically performed in a downward posture, and there is an effect that a highly reliable weld having few welding defects can be easily obtained. According to a sixth aspect of the present invention, there is provided a welding method for producing a welded structure for a pipe joint according to any one of the first to third aspects, wherein the pipe shaft of the branch pipe is provided. Hold the welding torch on a turntable that rotates around the center,
A welding method for a pipe joint portion in which welding is performed by moving the welding torch in a vertical direction while rotating the welding torch along the circumference of the pipe axis center of the branch pipe. With such a welding method, there is an effect that automatic welding of a pipe joint can be achieved only by using a simple automatic device. In addition, the present invention provides, as described in claim 7, claims 1 to 3
A welding method for producing a welded structure for a pipe joint according to any one of claims 1 to 3, wherein a shaft coinciding with a pipe axis of the branch pipe is inserted into the inside of the branch pipe, and a welding torch is held on the shaft. A method of welding a pipe joint portion in which welding is performed by moving the welding torch up and down while rotating the welding torch along the circumference of the pipe axis center of the branch pipe. By adopting such a welding method, there is an effect that the automatic welding of the pipe joint can be easily achieved simply by using a simple automatic device, as in the above-described claim 6. The welding structure of the pipe joint of the present invention is characterized in that a hole having a diameter slightly larger than the outer diameter of the branch pipe is formed in a side surface of the main pipe, and an end of the branch pipe to be welded is inserted into the hole, so that the branch pipe is connected to the main pipe. , And perform narrow groove welding from the inner side of the main pipe,
Alternatively, it can be realized by arranging the branch pipe so as to be above the main pipe and performing narrow groove welding from outside the main pipe. And it is not necessary to process the welding groove using expensive and special processing technology, and since the welding line (welding line) can be welded in a downward position over the entire circumference of the welded portion, the workability of welding is good, Because of the downward welding, there are almost no problems that cause welding defects.In addition, the narrow gap welding method can significantly reduce the amount of weld metal compared to the conventional horizontal position welding method. A highly reliable pipe joint welding structure with few defects can be realized.
【０００５】[0005]
【実施の形態】以下に、本発明の実施の形態について例
を挙げ、図面を用いてさらに詳細に説明する。 〈実施の形態１〉まず、溶接の開先形状およびその加工
方法について説明する。図１（ａ）、（ｂ）は、本発明
の管継手部の溶接構造における主管１側の溶接開先〔図
１（ｂ）〕および枝管２側の溶接開先〔図１（ａ）〕の
形状を示すものである。枝管側の溶接開先は、枝管２の
先端を、枝管２の管軸と直角な軸を中心として、主管の
内径ｄ1に等しい曲率で切削加工するだけでよい。ま
た、主管側の溶接開先としては、主管１の側面に、主管
１の管軸と直角方向に、枝管挿入用穴径ｄ4の円形の穴
を開ける。ここで、枝管挿入用穴径ｄ4は、枝管２の外
径ｄ3よりやや大きく取り、ｄ4＝ｄ3＋２×（開先幅）
〔単位ｍｍ〕とする。これらの開先加工には、３軸以上
の多軸制御の加工機械を必要とせず、一般に広く普及し
ている大型旋盤があればよい。図２に管継手部の溶接開
先合わせの状態を示す。枝管２を、主管１の側面に設け
た枝管挿入用の円形の穴に挿入して仮付けし、枝管２が
主管１の下側になるように、架台１２の上に配置する。
この図で示すように、主管１と枝管２の間の空隙である
主管側の開先面３ａと枝管側の開先面３ｂとの間が溶接
開先となる。図３は、図２に示した管継手部の溶接状況
を示す。回転軸を枝管２の管軸と一致させた回転台８を
枝管２の真下に設置し、回転台８に、支持アーム１０を
介して溶接トーチ９を取り付け、枝管２の中に下側から
挿入する。さらに、溶接トーチ９の先端を下に向けて溶
接開先内に挿入し、主管１の内面側から下向き姿勢で狭
開先溶接を行う。溶接方法としては、ＴＩＧ溶接法ある
いはＭＩＧ溶接法が適用できる。主管１の内面側から溶
接するため、主管１の外面側から溶接する場合に比べ
て、溶接トーチ９や支持アーム１０が枝管２と干渉する
ことがなく、比較的自在に溶接作業を行うことができ
る。溶接線（溶接ライン）は３次元溶接となるが、溶接
トーチ９の位置が、初層から最終層に至るまで、常に枝
管２の管軸から一定の距離にあるため、溶接中は溶接ト
ーチ９の周回に合わせて、図中の（ロ）方向に回転する
回転台８を、（イ）に示す上下方向に移動させるだけで
よく、溶接トーチ９の回転半径方向の調整は不要であ
る。すなわち、２軸制御で自動溶接が可能となる。ま
た、本発明では溶接開先のルート部がないが、初層を溶
接する際には、主管１の外側から当て金１１を用い、溶
接後に削り取ればよい。また、必要であれば裏側溶接を
行うこともできる。当て金１１の削り取りや裏側溶接は
従来技術とは異なり、主管１の外側からの作業となるた
め容易に行える。図４は、図３の当て金１１の代わり
に、インサートリング１３を用いる例を示したものであ
る。主管１と枝管２の溶接開先面３ａ、３ｂとを合わせ
て固定した後、インサートリング１３（丸棒状または角
棒状の金属）を主管１の外側から開先の下部に挿入して
溶接すればよく、容易に実施できる手段である。図５
に、主管１と枝管２を溶接した後の管継手部の接合状態
を示す。狭開先溶接法によるため、図９に示した従来技
術と比較して大幅に溶接金属４の量を低減することがで
きるので、溶接構造物としての信頼性を向上することが
できると共に、溶接工数も大幅に低減できる効果があ
る。本実施の形態では、開先加工の際に、多軸制御の高
級な加工機械を全く必要とせず、一般的な工作機械があ
ればよく、しかも単純な加工形状であるため加工工数を
大幅に削減することができる。また、溶接ラインの全周
にわたって下向き姿勢で溶接を施工することができるの
で作業性が良く、溶接欠陥も生じ難い。さらに、特殊な
多軸のマニピュレータ等を必要としないので、容易に自
動溶接が可能となる。Embodiments of the present invention will be described below in more detail with reference to the drawings. <Embodiment 1> First, the groove shape of welding and the processing method thereof will be described. FIGS. 1 (a) and 1 (b) show a weld groove on the main pipe 1 side (FIG. 1 (b)) and a weld groove on the branch pipe 2 side (FIG. 1 (a)). ] Is shown. The welding groove on the branch pipe side only needs to cut the tip of the branch pipe 2 with a curvature equal to the inner diameter d 1 of the main pipe around an axis perpendicular to the pipe axis of the branch pipe 2. As the weld groove of the main pipe side, the side surface of the main pipe 1, the tube axis and perpendicular direction of the main pipe 1, a circular drilling of the lateral pipe insertion hole diameter d 4. Here, the branch pipe insertion hole diameter d 4 is slightly larger than the outer diameter d 3 of the branch pipe 2, and d 4 = d 3 + 2 × (groove width).
[Unit mm]. These groove processing does not require a processing machine of multi-axis control of three or more axes, and it is sufficient to use a large-sized lathe that is widely used in general. FIG. 2 shows a state in which the welding groove of the pipe joint is aligned. The branch pipe 2 is inserted into a circular hole for inserting a branch pipe provided on a side surface of the main pipe 1 and temporarily attached, and is placed on the gantry 12 so that the branch pipe 2 is located below the main pipe 1.
As shown in this figure, a gap between the main pipe side groove surface 3a and the branch pipe side groove surface 3b, which is a gap between the main pipe 1 and the branch pipe 2, is a welding groove. FIG. 3 shows a welding state of the pipe joint shown in FIG. A turntable 8 whose rotation axis coincides with the pipe axis of the branch pipe 2 is installed directly below the branch pipe 2, and a welding torch 9 is attached to the turntable 8 via a support arm 10. Insert from the side. Furthermore, the tip of the welding torch 9 is inserted downward into the welding groove, and narrow groove welding is performed in a downward posture from the inner surface side of the main pipe 1. As a welding method, a TIG welding method or a MIG welding method can be applied. Since the welding is performed from the inner surface side of the main pipe 1, the welding torch 9 and the support arm 10 do not interfere with the branch pipe 2 and the welding operation can be performed relatively freely, compared to the case where welding is performed from the outer surface side of the main pipe 1. Can be. Although the welding line (welding line) is three-dimensional welding, the position of the welding torch 9 is always at a certain distance from the pipe axis of the branch pipe 2 from the first layer to the last layer. It is only necessary to move the turntable 8 that rotates in the direction (b) in the figure in the vertical direction shown in (a) in accordance with the rotation of 9, and it is not necessary to adjust the welding torch 9 in the rotational radius direction. That is, automatic welding can be performed by two-axis control. Further, in the present invention, there is no root portion of the welding groove, but when welding the first layer, it is only necessary to use the backing 11 from the outside of the main pipe 1 and scrape off after welding. Also, if necessary, backside welding can be performed. Unlike the prior art, shaving of the backing plate 11 and backside welding are performed from the outside of the main pipe 1 and thus can be easily performed. FIG. 4 shows an example in which an insert ring 13 is used instead of the backing 11 in FIG. After the welding groove surfaces 3a and 3b of the main pipe 1 and the branch pipe 2 are aligned and fixed, an insert ring 13 (round bar or square bar metal) is inserted into the lower part of the groove from outside the main pipe 1 and welded. It is a means that can be easily implemented. FIG.
2 shows a joint state of the pipe joint after the main pipe 1 and the branch pipe 2 are welded. Since the narrow groove welding method is used, the amount of the weld metal 4 can be greatly reduced as compared with the prior art shown in FIG. 9, so that the reliability as a welded structure can be improved and the welding can be performed. This has the effect that the number of steps can be significantly reduced. In the present embodiment, a high-end multi-axis control processing machine is not required at the time of the bevel processing, and a general machine tool is sufficient. Can be reduced. In addition, since welding can be performed in a downward posture over the entire circumference of the welding line, workability is good, and welding defects hardly occur. Further, since a special multi-axis manipulator or the like is not required, automatic welding can be easily performed.
【０００６】〈実施の形態２〉本発明の他の実施の形態
を図６に示す。管継手部の溶接構造としては、上記実施
の形態１と同様であるが、本実施の形態では、溶接トー
チを回転台（図３、４の符号８）に取り付けるのではな
く、治具１５を介して、枝管２に直接取り付けて溶接を
行う例を示した。図６において、溶接トーチ９は、治具
１５に固定された支持アーム１０に取り付けられてお
り、回転機構１４によって、支持アーム１０を中心に回
転する。支持アーム１０と枝管２の管軸とが一致するよ
うに、治具１５を枝管２の先端に固定し、主管１の内面
側から溶接トーチ９を、主管側の開先面３ａと枝管側の
開先面３ｂとの間に挿入して溶接を行う。以後の溶接手
順および得られる効果は、上記実施の形態１と同様であ
るが、回転台を設置できないような場所での溶接施工の
場合は好適に用いられる。<Embodiment 2> FIG. 6 shows another embodiment of the present invention. The welding structure of the pipe joint is the same as that of the first embodiment, but in this embodiment, the welding torch is not attached to the turntable (8 in FIGS. 3 and 4), but the jig 15 is attached. An example in which welding is performed by directly attaching the branch pipe 2 to the branch pipe 2 is shown. In FIG. 6, the welding torch 9 is attached to a support arm 10 fixed to a jig 15, and is rotated about the support arm 10 by a rotation mechanism 14. The jig 15 is fixed to the tip of the branch pipe 2 so that the support arm 10 and the pipe axis of the branch pipe 2 coincide with each other, and the welding torch 9 is inserted from the inner surface side of the main pipe 1 to the groove 3a on the main pipe side and the branch. Welding is performed by inserting between the groove side surface 3b on the tube side. The subsequent welding procedure and the effects obtained are the same as those in the first embodiment, but are preferably used in the case of welding work in a place where a turntable cannot be installed.
【０００７】〈実施の形態３〉本発明の他の実施の形態
を図７および図８に示す。管継手部の溶接構造として
は、上記実施の形態１と同様であるが、本実施の形態で
は、溶接の施工を主管１の内側からではなく、主管１の
外側から狭開先溶接を行う方法である。主管１および枝
管２の溶接開先は、図１で示した溶接開先と同様であ
る。図７は、溶接開先合わせの状態を示すもので、枝管
２を、主管１の側面に設けた枝管挿入用の円形の穴に挿
入し、仮付けをして、枝管２が主管１の上側となるよう
に架台１２の上に配置する。この図７では、主管１と枝
管２の間の開先面３ａと開先面３ｂの空隙が溶接開先と
なる。図８に、図７に示した溶接開先合わせ部の溶接方
法を示す。溶接トーチ９は、治具１５に設けられた支持
アーム１０に取り付けられており、支持アーム１０は、
回転機構１４によって、軸１６を中心として回転する。
軸１６は、枝管２の管軸と一致するように、治具１５を
枝管２の先端部に固定し、主管１の外面側から溶接トー
チ９を開先面３ａ、３ｂとの間に挿入して、下向き姿勢
で溶接を行う。以後の溶接手順および得られる効果は、
上記実施の形態１、２と同様である。本実施の形態で
は、枝管２ゃ主管１の内径が小さく、主管１の内側から
溶接することが困難な場合に好適である。Third Embodiment FIGS. 7 and 8 show another embodiment of the present invention. The welding structure of the pipe joint portion is the same as that of the first embodiment, but in this embodiment, the welding is performed not from the inside of the main pipe 1 but from the outside of the main pipe 1 by narrow groove welding. It is. The welding groove of the main pipe 1 and the branch pipe 2 is the same as the welding groove shown in FIG. FIG. 7 shows a state in which the welding groove is aligned. The branch pipe 2 is inserted into a circular hole for branch pipe insertion provided on the side surface of the main pipe 1 and is temporarily attached. 1 on the gantry 12. In FIG. 7, the gap between the groove surface 3a and the groove surface 3b between the main pipe 1 and the branch pipe 2 becomes a welding groove. FIG. 8 shows a welding method of the welding groove fitting portion shown in FIG. The welding torch 9 is attached to a support arm 10 provided on a jig 15.
The rotation mechanism 14 rotates about the shaft 16.
The shaft 16 fixes the jig 15 to the distal end of the branch pipe 2 so as to coincide with the pipe axis of the branch pipe 2, and places the welding torch 9 from the outer surface side of the main pipe 1 between the groove faces 3 a and 3 b. Insert and weld in a downward position. The subsequent welding procedure and the effect obtained are
This is the same as the first and second embodiments. This embodiment is suitable when the inner diameter of the branch pipe 2 ゃ the main pipe 1 is small and it is difficult to weld from the inside of the main pipe 1.
【０００８】[0008]
【発明の効果】本発明の管継手部の溶接構造およびその
溶接方法は、高級な開先加工機械を必要とすることな
く、一般に用いられている加工機械で簡易に溶接開先加
工が行えるので安価な管継手部の溶接構造が得られる。
また、溶接ラインの全周にわたって、下向き姿勢で溶接
が行えるので溶接作業性が良く、溶接欠陥が生じ難い。
また、溶接施工のための周辺装置としては２軸制御がで
きるものでよく、簡易に自動溶接化が可能である。さら
に、狭開先溶接法であるため溶接金属の量を従来技術に
比べて大幅に低減できるので、溶接部の品質の信頼性が
著しく向上し、溶接の工数低減にも有効であり、工業
的、経済的効果は大きい。The welding structure for a pipe joint and the method for welding the same according to the present invention do not require a high-grade beveling machine, and can easily perform weld beveling with a commonly used processing machine. An inexpensive welded structure for the pipe joint can be obtained.
In addition, since welding can be performed in a downward posture over the entire circumference of the welding line, welding workability is good and welding defects are less likely to occur.
Further, a peripheral device for performing welding may be a device capable of two-axis control, and automatic welding can be easily performed. In addition, the narrow groove welding method makes it possible to significantly reduce the amount of weld metal compared to the conventional technology, significantly improving the reliability of the quality of the welded portion, and is effective in reducing the number of welding steps. The economic effect is great.
【図１】本発明の実施の形態１で例示した管継手部の主
管と枝管の溶接開先形状を示す模式図。FIG. 1 is a schematic view showing a weld groove shape of a main pipe and a branch pipe of a pipe joint illustrated in Embodiment 1 of the present invention.
【図２】本発明の実施の形態１で例示した管継手部の主
管と枝管の開先合わせの状態を示す模式図。FIG. 2 is a schematic view showing a state in which a main pipe and a branch pipe of the pipe joint illustrated in the first embodiment of the present invention are grooved;
【図３】本発明の実施の形態１で例示した管継手部の主
管と枝管の溶接方法を示す模式図。FIG. 3 is a schematic view showing a method of welding the main pipe and the branch pipe of the pipe joint illustrated in the first embodiment of the present invention.
【図４】本発明の実施の形態１で例示した管継手部の主
管と枝管の溶接開先部にインサートリングを用いた場合
の溶接方法を示す模式図。FIG. 4 is a schematic view showing a welding method when an insert ring is used for a welding groove between a main pipe and a branch pipe of the pipe joint illustrated in the first embodiment of the present invention.
【図５】本発明の実施の形態１で例示した管継手部の主
管と枝管の溶接状態を示す模式図。FIG. 5 is a schematic view showing a welded state of a main pipe and a branch pipe of the pipe joint illustrated in the first embodiment of the present invention.
【図６】本発明の実施の形態２で例示した管継手部の主
管と枝管の溶接方法を示す模式図。FIG. 6 is a schematic view showing a method of welding a main pipe and a branch pipe of a pipe joint illustrated in Embodiment 2 of the present invention.
【図７】本発明の実施の形態３で例示した管継手部の主
管と枝管の開先合わせの状態を示す模式図。FIG. 7 is a schematic view showing a state in which a main pipe and a branch pipe of a pipe joint illustrated in Embodiment 3 of the present invention are grooved.
【図８】本発明の実施の形態３で例示した管継手部の主
管と枝管の溶接方法を示す模式図。FIG. 8 is a schematic view showing a method of welding a main pipe and a branch pipe of a pipe joint illustrated in Embodiment 3 of the present invention.
【図９】従来のボイラにおける蒸気管寄せの構造の一例
を示す模式図。FIG. 9 is a schematic diagram showing an example of a structure of a steam header in a conventional boiler.
【図１０】従来の主管と枝管の開先形状と溶接方法を示
す模式図。FIG. 10 is a schematic view showing a conventional groove shape of a main pipe and a branch pipe and a welding method.
【図１１】従来の主管と枝管の溶接状態を示す模式図。FIG. 11 is a schematic view showing a conventional welding state of a main pipe and a branch pipe.
１…主管 ２…枝管 ３…開先面 ３ａ…開先面 ３ｂ…開先面 ４…溶接金属 ５…管寄せ ６…伝熱管 ７…連絡管 ８…回転台 ９…溶接トーチ １０…支持アーム １１…当て金 １２…架台 １３…インサートリング １４…回転機構 １５…治具 １６…軸 ｄ1…主管の内径 ｄ2…主管の外径 ｄ3…枝管の外径 ｄ4…枝管挿入用穴径DESCRIPTION OF SYMBOLS 1 ... Main pipe 2 ... Branch pipe 3 ... Groove face 3a ... Groove face 3b ... Groove face 4 ... Weld metal 5 ... Head pipe 6 ... Heat transfer pipe 7 ... Connecting pipe 8 ... Turntable 9 ... Welding torch 10 ... Support arm 11 ... straps 12 ... frame 13 ... insert ring 14 ... rotating mechanism 15 ... jig 16 ... axis d 1 ... for the outer diameter d 4 ... branch pipe insertion of the main pipe of inside diameter d 2 ... main outer diameter d 3 ... branch pipe Hole diameter
Claims (7)
であって、上記主管に、上記枝管の外径よりもやや大き
い径の穴を開け、該主管の穴部に、溶接接合する枝管の
端部を挿入して、上記主管の穴の内面と上記枝管の端部
の外周面との間の隙間部に溶接開先を形成し、該溶接開
先内に溶接トーチの先端部を挿入して、下向き姿勢で溶
接トーチの先端部を枝管の外周方向および上下方向に移
動させながら溶接してなることを特徴とする管継手部の
溶接構造。1. A welding structure for a pipe joint in which a branch pipe intersects a main pipe, wherein a hole having a diameter slightly larger than an outer diameter of the branch pipe is formed in the main pipe, and a welding hole is formed in a hole of the main pipe. An end of the branch pipe to be joined is inserted to form a welding groove in a gap between the inner surface of the hole of the main pipe and the outer peripheral surface of the end of the branch pipe, and a welding torch is formed in the welding groove. A welding structure for a pipe joint portion, wherein the welding portion is formed by inserting a tip portion of the welding torch in a downward position and moving the tip portion of the welding torch in an outer circumferential direction and a vertical direction of the branch pipe.
いて、主管に開ける枝管の外径よりもやや大きい穴径
（Ｄ）は、Ｄ＝｛（枝管の外径）＋２×（開先幅）｝ｍ
ｍとすることを特徴とする管継手部の溶接構造。2. The welding structure for a pipe joint according to claim 1, wherein the hole diameter (D) slightly larger than the outer diameter of the branch pipe opened in the main pipe is D = ｛(outer diameter of branch pipe) + 2 × (Groove width)｝ m
m, a welded structure for a pipe joint.
いて、主管の穴の内面と枝管の端部の外周面との間に形
成される溶接開先の下部に、初層を溶接する際に用いる
主管の外面側から当て金を装着するか、もしくは丸棒状
または角棒状の金属製インサートリングを上記溶接開先
の下部に挿着してなることを特徴とする管継手部の溶接
構造。3. The welding structure for a pipe joint according to claim 1, wherein an initial layer is formed below a welding groove formed between an inner surface of a hole of the main pipe and an outer peripheral surface of an end of the branch pipe. A pipe fitting is characterized in that a metal plate is attached from the outer surface side of the main pipe used for welding, or a round or square bar-shaped metal insert ring is inserted into a lower portion of the welding groove. Welded structure.
記載の管継手部の溶接構造を作製する溶接方法であっ
て、枝管が主管の下側となるように配置し、上記主管の
内面側から下向き姿勢で溶接を行うことを特徴とする管
継手部の溶接方法。4. A welding method for producing a welded structure of a pipe joint according to claim 1, wherein the branch pipe is disposed below the main pipe. A method of welding a pipe joint, wherein the welding is performed in a downward position from an inner surface side of a main pipe.
記載の管継手部の溶接構造を作製する溶接方法であっ
て、枝管が主管の上側となるように配置し、主管の外面
側から下向き姿勢で溶接を行うことを特徴とする管継手
部の溶接方法。5. A welding method for producing a welded structure for a pipe joint according to any one of claims 1 to 3, wherein the branch pipe is disposed above the main pipe, and A method of welding a pipe joint, wherein the welding is performed in a downward position from an outer surface side.
記載の管継手部の溶接構造を作製する溶接方法であっ
て、枝管の管軸を中心に回転する回転台上に溶接トーチ
を保持して、該溶接トーチを枝管の管軸中心の円周上に
沿って回転させながら上下方向に動かすことにより溶接
を行うことを特徴とする管継手部の溶接方法。6. A welding method for producing a welded structure for a pipe joint according to claim 1, wherein the welding is performed on a turntable that rotates about a pipe axis of a branch pipe. A welding method for a pipe joint portion, wherein the welding is performed by holding the torch and moving the welding torch in a vertical direction while rotating the welding torch along the circumference of the center axis of the branch pipe.
記載の管継手部の溶接構造を作製する溶接方法であっ
て、枝管の管軸と一致する軸を枝管の内部に挿入し、該
軸に溶接トーチを保持して、該溶接トーチを枝管の管軸
中心の円周上に沿って回転させながら上下方向に動かす
ことにより溶接を行うことを特徴とする管継手部の溶接
方法。7. A welding method for producing a welded structure for a pipe joint according to claim 1, wherein an axis coinciding with the pipe axis of the branch pipe is provided inside the branch pipe. A pipe joint portion, wherein the welding is performed by inserting, holding a welding torch on the shaft, and moving the welding torch up and down while rotating the welding torch along the circumference of the center axis of the branch pipe. Welding method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28377098A JP2000107858A (en) | 1998-10-06 | 1998-10-06 | Welded structure of pipe jointing part and welding method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28377098A JP2000107858A (en) | 1998-10-06 | 1998-10-06 | Welded structure of pipe jointing part and welding method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000107858A true JP2000107858A (en) | 2000-04-18 |
Family
ID=17669902
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28377098A Pending JP2000107858A (en) | 1998-10-06 | 1998-10-06 | Welded structure of pipe jointing part and welding method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000107858A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012129994A1 (en) * | 2011-03-30 | 2012-10-04 | 上海锅炉厂有限公司 | Automatic submerged arc welding method for large inserted connecting tube on cone |
| CN109648240A (en) * | 2019-01-24 | 2019-04-19 | 奥克斯空调股份有限公司 | A kind of welder |
-
1998
- 1998-10-06 JP JP28377098A patent/JP2000107858A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012129994A1 (en) * | 2011-03-30 | 2012-10-04 | 上海锅炉厂有限公司 | Automatic submerged arc welding method for large inserted connecting tube on cone |
| CN109648240A (en) * | 2019-01-24 | 2019-04-19 | 奥克斯空调股份有限公司 | A kind of welder |
| CN109648240B (en) * | 2019-01-24 | 2021-01-29 | 奥克斯空调股份有限公司 | Welding device |
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