JP2004358535A

JP2004358535A - Method of joining thick material to be joined, and joined structure

Info

Publication number: JP2004358535A
Application number: JP2003162459A
Authority: JP
Inventors: Hisashi Hori; 久司堀; Isato Sato; 勇人佐藤; Shinya Makita; 慎也牧田
Original assignee: Nippon Light Metal Co Ltd
Current assignee: Nippon Light Metal Co Ltd
Priority date: 2003-06-06
Filing date: 2003-06-06
Publication date: 2004-12-24
Anticipated expiration: 2023-06-06
Also published as: JP4273846B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of closely joining the thick materials to be joined, and to provide a joined structure. <P>SOLUTION: In the joined structure of the thick materials to be joined, a pair of thick materials 1, 1 to be joined in which a step part comprising an outside edge face, an intermediate face and an inside edge face is each formed along the respective joining edges and the outside edge faces are mutually butted, and a connection board 5 inserted into a recessed part formed between the intermediate faces and the inside edge faces of both the thick materials 1, 1 to be joined and having a cross-sectional shape same as or similar to that of the recessed part are provided. A butted part obtained by mutually butting the outside faces of both the thick materials 1, 1 to be joined and butted parts between the connection board 5 and the inside edge face of each material 1, 1 to be joined are respectively subjected to friction stir joining to form joining lines W1 and W2. Further, the boundary face 7 between the connection board 5 and the bottom face of the recessed part is subjected to friction stirring. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、厚肉の被接合材同士を隙間なく接合する方法及び構造に関する。
【０００２】
【従来の技術】
特許文献１には、厚肉の被接合材同士を摩擦攪拌接合する方法が開示されている。その手順としては、まず図２１（Ａ）に示すように、一対の厚肉被接合材１，１の各接合端に、外側端面２ａと中間面２ｂと内側端面２ｃとからなる段部２を形成しておく。そして図２１（Ｂ）に示すように、これら一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、この突合せ部３に沿って摩擦攪拌接合用のツール１０を挿入して摩擦攪拌接合を施すことにより、両厚肉被接合材１，１を接合して接合線Ｗ１を形成する。次に図２１（Ｃ）に示すように、両厚肉被接合材１，１の中間面２ｂ，２ｂと内側端面２ｃ，２ｃとで形成される凹部４に、この凹部４と同一又は相似の断面形状の接続板５を装入する。最後に図２１（Ｄ）に示すように、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの突合せ部６，６に沿って摩擦攪拌接合用のツール１０を挿入してそれぞれ摩擦攪拌接合を施すことにより、接合線Ｗ２，Ｗ２を形成する。このように、被接合材の厚さ方向に二段に分けて摩擦攪拌接合を施すことにより、既存の接合ツールでは対応できないような厚肉の被接合材を互いに接合することができる。
【０００３】
【特許文献１】
特許第３３０７３３０号公報（［００１３］−［００１８］，図１−２）
【０００４】
【発明が解決しようとする課題】
しかしながら、上記従来の方法によって接合された接合構造では、図２２に示したように、接続板５の底面と凹部４の底面（各厚肉被接合材１，１の中間面２ｂ，２ｂ）とが未接合のままで隙間８が残ってしまうことがある。また、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの突合せ部６を摩擦攪拌接合してなる接合線Ｗ２の内部に、ツールの進行方向に連続するトンネル状空洞欠陥９が残ってしまうことがある。そして、かかる隙間８やトンネル状空洞欠陥９は当該部分の気密性を低下させるので、この接合構造をたとえば半導体製造装置の真空処理容器等に用いた場合にはリークが発生しやすく、容器内を超高真空状態にして長時間保持することができないなどという問題がある。
【０００５】
本発明はかかる事情に鑑みてなされたものであり、厚肉の被接合材同士を隙間なく接合する厚肉被接合材の接合方法（以下、単に「接合方法」という。）及び厚肉被接合材の接合構造（以下、単に「接合構造」という。）を提案するものである。
【０００６】
【課題を解決するための手段】
すなわち、請求項１に係る発明は、それぞれの接合端に沿って外側端面と中間面と内側端面とを含む段部が形成された一対の厚肉被接合材の前記外側端面同士を突き合わせて、該突合せ部を摩擦攪拌接合する第一工程と、前記両厚肉被接合材の中間面と内側端面とで形成される凹部に、該凹部と同一又は相似の断面形状の接続板を装入する第二工程と、前記接続板と前記各厚肉被接合材の内側端面との突合せ部をそれぞれ摩擦攪拌接合するとともに、前記接続板と前記凹部の底面との境界面を摩擦攪拌する第三工程と、を含んでなることを特徴とする接合方法である。
また、請求項３に係る発明は、それぞれの接合端に沿って外側端面と中間面と内側端面とを含む段部が形成された一対の厚肉被接合材の前記外側端面同士を突き合わせるとともに、前記両厚肉被接合材の中間面と内側端面とで形成される凹部に、該凹部と同一又は相似の断面形状の接続板を装入する第一工程と、前記一対の厚肉被接合材の外側端面同士を突き合わせてなる突合せ部と、前記接続板と前記各厚肉被接合材の内側端面との突合せ部と、についてそれぞれ摩擦攪拌接合を施すとともに、前記接続板と前記凹部の底面との境界面を摩擦攪拌する第二工程と、を含んでなることを特徴とする接合方法である。
さらに、請求項７に係る発明は、それぞれの接合端に沿って外側端面と中間面と内側端面とを含む段部が形成され、前記外側端面同士が突き合わされた一対の厚肉被接合材と、前記両厚肉被接合材の中間面と内側端面とで形成される凹部に装入された、該凹部と同一又は相似の断面形状の接続板と、を備え、前記両厚肉被接合材の外側面同士を突き合わせてなる突合せ部と、前記接続板と前記各厚肉被接合材の内側端面との突合せ部と、がそれぞれ摩擦攪拌接合されているとともに、前記接続板と前記凹部の底面との境界面が摩擦攪拌されている、ことを特徴とする接合構造である。
【０００７】
かかる接合方法ないし接合構造によれば、従来の接合方法ないし接合構造において未接合のまま残されていた、接続板と凹部の底面との境界面が摩擦攪拌により一体化されるので、当該部分の隙間をなくした気密性の高い接合部を形成することができる。
【０００８】
また、請求項２に係る発明は、請求項１に記載の接合方法の第三工程において、前記接続板と前記各厚肉被接合材の内側端面との突合せ部を摩擦攪拌接合した後に、前記接続板と前記凹部の底面との境界面を摩擦攪拌する、ことを特徴とする。
また、請求項４に係る発明は、請求項３に記載の接合方法の第二工程において、前記一対の厚肉被接合材の外側端面同士を突き合わせてなる突合せ部と、前記接続板と前記各厚肉被接合材の内側端面との突合せ部と、についてそれぞれ摩擦攪拌接合を施した後に、前記接続板と前記凹部の底面との境界面を摩擦攪拌する、ことを特徴とする。
【０００９】
かかる接合方法では、接続板と凹部の底面との境界面についての摩擦攪拌の前に、一対の厚肉被接合材の外側端面同士を突き合わせてなる突合せ部と、接続板と各厚肉被接合材の内側端面との突合せ部と、についての摩擦攪拌接合が完了しているので、摩擦攪拌時の接続板の位置決め・固定が容易である。
【００１０】
また、請求項５に係る発明は、請求項１乃至請求項４のいずれか一項に記載の接合方法において、前記接続板と前記凹部の底面との境界面の摩擦攪拌を、前記接続板と前記各厚肉被接合材の内側端面との突合せ部を横断して施す、ことを特徴とする。
また、請求項８に係る発明は、請求項７に記載の接合構造において、前記接続板と前記凹部の底面との境界面の摩擦攪拌が、前記接続板と前記各厚肉被接合材の内側端面との突合せ部を横断して施されている、ことを特徴とする。
【００１１】
かかる接合方法ないし接合構造によれば、接続板と各厚肉被接合材の内側端面との突合せ部を横断して摩擦攪拌が施されるので、摩擦攪拌接合したときにトンネル状空洞欠陥が発生したとしても、このトンネル状空洞欠陥を分断して、気密性をさらに高めることができる。
【００１２】
また、請求項６に係る発明は、請求項１乃至請求項５のいずれか一項に記載の接合方法において、前記接続板と前記凹部の底面との境界面を摩擦攪拌する際に、該接続板の中心部から周縁部に向かって摩擦攪拌用ツールを移動させる、ことを特徴とする。
【００１３】
かかる接合方法によれば、摩擦攪拌時に接続板の中心部から周縁部に向かって摩擦攪拌用ツールを移動させるので、境界面に残存するエアーを巻き込むことなく接合できる。周縁部から中心部に向かって接合した場合、エアー巻き込みによるトンネル状欠陥が発生する。
【００１４】
【発明の実施の形態】
以下、添付図面を参照しつつ、本発明の実施の形態を詳細に説明する。なお、説明において、同一要素には同一の符号を用い、重複する説明は省略するものとする。また、厚肉被接合材として厚肉のアルミニウム板材を用い、且つ摩擦攪拌接合装置の接合能力が厚さ５ｍｍの場合を想定している。
【００１５】
＜第一実施形態＞
図１〜図４は本発明に係る接合方法の第一実施形態の各工程を表す断面図である。
まず、図１（Ａ）に示すように、接合すべき一対の厚肉被接合材１，１を、それぞれの外側端面２ａ，２ａで面接触させて突合せ部３を形成した上で、図示しない治具で拘束する。各厚肉被接合材１の厚さは５〜１０ｍｍであり、それぞれの接合端に沿って段部２が形成されている。段部２は、外側端面２ａと中間面２ｂと内側端面２ｃとを含んで形成されている。そして、一対の厚肉被接合材１，１の外側端面２ａ，２ａを互いに突き合わせたときに、連続する両中間面２ｂ，２ｂと、対向する一対の内側端面２ｃ，２ｃとで凹部４が形成される。なお、厚肉被接合材１にはアルミニウムの圧延板（ＡＡ５０５２合金、ＡＡ６０６１合金）を切削加工したものか、あるいは、段部２を予め一体に形成したアルミニウム（ＪＩＳ；Ａ６０６３−Ｔ５又はＴ６等）の押出形材が用いられる。
【００１６】
次に、図１（Ｂ）に示すように、突合せ部３上に、摩擦攪拌接合用のツール１０をセットする。このツール１０は、工具鋼からなり、回転円柱体１１と、その底面であって緩く湾曲して凹んだ表面押え部１２の中心から同軸にて垂下する攪拌ピン１３とからなる。この攪拌ピン１３は、厚肉被接合材１の外側端面２ａや内側端面２ｃの高さより若干短く、その周面には、図示しないネジ状の小さな摩擦攪拌翼が形成されている。そして、図１（Ｃ）及び（ｃ）に示すように、回転円柱体１１と攪拌ピン１３の中心軸を各厚肉被接合材１，１の突合せ部３に沿ってやや斜めにした状態で、図示しないモータによりツール１０を回転させつつ突合せ部３に向けて進入させる。ツール１０の回転速度は３００〜５０００ｒｐｍの範囲内において適宜選択される。なお、厚肉被接合材１，１は予め互いに長手方向及び幅方向に移動しないように拘束されている。
【００１７】
次いで、図示のように、ツール１０を各厚肉被接合材１に対し垂直方向に押圧し、表面押え部１２全体が中間面２ｂ，２ｂの表面に達するまで攪拌ピン１３を押し込む。この状態で、ツール１０をその傾斜した向きと反対方向に（図１（ｃ）で左方）に移動させる。この送り速度は、０．０２〜２ｍ／分の範囲内において適宜選択される。このツール１０の回転と移動に伴って、突合せ部３付近のメタルは攪拌ピン１３により加熱され可塑化されると共に、突合せ部３の左右の厚肉被接合材１，１間において水平及び垂直方向に流動化される。
【００１８】
また、流動化されたメタルは、ツール１０の表面押え部１２により垂直方向の流動に対し一定の圧力を与えられると共に、突合せ部３の表面付近から外部に飛散することを阻止される。この結果、図１（Ｄ），（ｄ）に示すように、ツール１０が通過した後において、流動化されたメタルは、流動化状態から固化して断面略半楕円形の接合線Ｗ１となる。この接合線Ｗ１の表面は、表面押え部１２により、その直径の幅相当分が僅かに凹むが、突合せ部３に沿って所要の長さで連続し、且つ表面が平らな接合線Ｗ１となる。
【００１９】
次いで、図２（Ａ），（Ｂ）に示すように、厚肉被接合材１，１の連続する両中間面２ｂ，２ｂと、対向する一対の内側端面２ｃ，２ｃとで形成された凹部４内に、この凹部４と同じ断面を有するアルミニウム製の接続板５を装入し、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの間に突合せ部６，６を形成する。そして、図２（Ｃ），（Ｄ）に示すように、突合せ部６，６に沿って、前記同様にツール１０を用いて摩擦攪拌接合を順次施す。その結果、図２（Ｅ）に示すように、突合せ部６，６に沿って、接続板５と各厚肉被接合材１，１とを接合する平行な一対の接合線Ｗ２，Ｗ２が形成される。
【００２０】
次に、図３及び図４（Ａ），（Ｂ）に示すように、摩擦攪拌用のツール２０を接続板５の上方から挿入して、凹部４の底面（中間面２ｂ，２ｂ）と接続板５の底面との境界面７を摩擦攪拌して一体化しながら、ツール２０を接続板５に沿って移動させる。図５に示すように、摩擦攪拌用のツール２０は工具鋼からなり、回転円柱体２１と、その水平な底面である表面押え部２２の中心から同軸にて垂下する攪拌ピン２３とを備えている。表面押え部２２には、その周縁から攪拌ピン２３の基端部に向かって、底面視で略二周の渦巻状に突出する凸条２４が形成されている。この凸条２４は、図５（Ｂ）中の矢印で示す方向にツール２０が回転したときに、塑性化したメタルを攪拌ピン２３の基端部に向かって強制的に集めるような向きで形成されている。また、攪拌ピン２３の周面には、ネジ状の小さな摩擦攪拌翼２５が形成されている。この摩擦攪拌翼２５は、図５（Ｂ）中の矢印で示す方向にツール２０が回転したときに、塑性化したメタルを下方から上方に向かって（攪拌ピン２３の先端から表面押え部２２に向かって）強制的に集めるような向きで形成されている。
【００２１】
そして、回転円柱体２１と攪拌ピン２３の中心軸を接続板５の表面に垂直な向きであるいはやや傾斜させて、図示しないモータによりツール２０を回転させつつ接続板５に向けて進入させる。ツール２０の回転に伴って、凹部４の底面（中間面２ｂ，２ｂ）と接続板５の底面との境界面７付近のメタルは攪拌ピン２３により加熱され可塑化されると共に、当該部分において水平及び垂直方向に流動化され、凹部４の底面付近の厚肉被接合材１，１のメタルと接続板５の底面付近のメタルとが一体化して、境界面７の微細な隙間が塞がれる。そして、接続板５の表面を表面押え部２２で押さえ込みながら、ツール２０を接続板５の表面全面に沿って順次移動させることにより、境界面７の微細な隙間を全て塞ぐことができる。
【００２２】
ここで、ツール２０を、図３及び図４（Ｂ）に示したように、接続板５の中心付近から周縁部に向かって平面視で螺旋模様の連続的な軌跡を描くように移動させれば、境界面に残存するエアーが接合部に巻き込まれることなく接合でき、さらにツール２０を引き抜いたときに不可避的にできる孔を接続板５内に残さないようにすることができる。
もちろん、ツール２０の移動軌跡はこれに限定されるものではなく、たとえば図６（Ａ）に示すように、Ｕターンを繰り返しつつ接合線Ｗ２に平行な向きで移動させるようにしてもよいし、図６（Ｂ）に示すように、Ｕターンを繰り返しつつ接合線Ｗ２に直交する向きで移動させるようにしてもよく、これら以外の移動パターンとしてもよい。連続的にでも不連続的にでもよいが、ツール２０が接続板５の表面全面を満遍なく通過するようにして、境界面７の隙間の接合線Ｗ２方向の連続性を分断することが重要である。
【００２３】
ツール２０による摩擦攪拌が完了すると、図７（Ａ）に示すように、接続板５が、ツール２０が通過した後にできる攪拌部Ｗ３となる。攪拌部Ｗ３は境界面７を含むように形成されるので、凹部４の底面と接続板５のメタルが一体化して、境界面７の微細な隙間が塞がれた接合構造を得ることができる。
なお、図７（Ｂ）に示すように、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの突合せ部６，６（接合線Ｗ２，Ｗ２）を横断するようにツール２０を移動させれば、境界面７の隙間が塞がれるだけでなく、接合線Ｗ２，Ｗ２内のトンネル状空洞欠陥が攪拌部Ｗ３で分断されるので、より気密性の高い接合構造となる。
【００２４】
＜第二実施形態＞
図８は本発明に係る接合方法の第二実施形態の各工程を表す断面図である。本実施形態は基本的に第一実施形態と同様であるが、突合せ部６，６の摩擦攪拌接合と境界面７の摩擦攪拌の順序のみにおいて異なる。
つまり、まず図８（Ａ）に示すように、それぞれの接合端に沿って外側端面２ａと中間面２ｂと内側端面２ｃとを含む段部２が形成された一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、該突合せ部３を摩擦攪拌接合して接合線Ｗ１を形成する。
次に図８（Ｂ）に示すように、両厚肉被接合材１，１の中間面２ｂ，２ｂと内側端面２ｃ，２ｃとで形成される凹部４に該凹部４と同一断面形状の接続板５を装入した後、接続板５の上方から摩擦攪拌用のツール２０を挿入し、凹部４の底面（中間面２ｂ，２ｂ）と接続板５の底面との境界面７を摩擦攪拌して一体化させ、境界面７を含む攪拌部Ｗ３を形成する。
最後に図８（Ｃ）に示すように、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの間の突合せ部６，６を順次あるいは同時に摩擦攪拌接合する。
【００２５】
このようにして得られる接合構造も、第一実施形態と同様、凹部４の底面と接続板５のメタルが一体化して、境界面７の微細な隙間が塞がれた気密性の高いものとなっている。
なお、第一実施形態と異なり、凹部４の底面と接続板５の底面との境界面７を摩擦攪拌して一体化させる際には、接続板５が移動しないように強固に拘束しておく必要がある。
【００２６】
＜第三実施形態＞
図９は本発明に係る接合方法の第三実施形態の各工程を表す断面図である。本実施形態は基本的に第二実施形態と同様であるが、境界面７の摩擦攪拌時のツールの挿入方向のみにおいて異なる。
つまり、まず図９（Ａ）に示すように、それぞれの接合端に沿って外側端面２ａと中間面２ｂと内側端面２ｃとを含む段部２が形成された一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、該突合せ部３を摩擦攪拌接合して接合線Ｗ１を形成する。
次に図９（Ｂ）に示すように、両厚肉被接合材１，１の中間面２ｂ，２ｂと内側端面２ｃ，２ｃとで形成される凹部４に該凹部４と同一断面形状の接続板５を装入した後、接続板５の下方（接合線Ｗ１側）から摩擦攪拌用のツール２０を挿入し、凹部４の底面（中間面２ｂ，２ｂ）と接続板５の底面との境界面７を摩擦攪拌して一体化させ、境界面７を含む攪拌部Ｗ３を形成する。
最後に図９（Ｃ）に示すように、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの間の突合せ部６，６を順次あるいは同時に摩擦攪拌接合する。
【００２７】
＜第四実施形態＞
図１０は本発明に係る接合方法の第四実施形態の各工程を表す断面図である。本実施形態は基本的に第一実施形態と同様であるが、突合せ部６，６の摩擦攪拌接合と境界面７の摩擦攪拌の順序のみにおいて異なる。
つまり、まず図１０（Ａ）に示すように、それぞれの接合端に沿って外側端面２ａと中間面２ｂと内側端面２ｃとを含む段部２が形成された一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、該突合せ部３を摩擦攪拌接合して接合線Ｗ１を形成する。
次に図１０（Ｂ），（Ｃ）に示すように、両厚肉被接合材１，１の中間面２ｂ，２ｂと内側端面２ｃ，２ｃとで形成される凹部４に該凹部４と同一断面形状の接続板５を装入した後、接続板５の上方から摩擦攪拌用のツール２０を挿入し、凹部４の底面（中間面２ｂ，２ｂ）と接続板５の底面との境界面７を摩擦攪拌するとともに、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの間の突合せ部６，６を摩擦攪拌接合する。つまり、突合せ部６，６の摩擦攪拌接合と境界面７の摩擦攪拌とを区別せず、突合せ部６，６を包含するように摩擦攪拌を行うことにより、接続板５と各厚肉被接合材１，１との接合と、境界面７を含む攪拌部Ｗ３の形成を同時並行的に行うのである。したがって、作業工程の簡略化を図ることが可能である。
【００２８】
＜第五実施形態＞
図１１は本発明に係る接合方法の第五実施形態の各工程を表す断面図である。本実施形態は、突合せ部３の接合タイミングのみにおいて上記各実施形態と異なる。
つまり、まず図１１（Ａ）に示すように、それぞれの接合端に沿って外側端面２ａと中間面２ｂと内側端面２ｃとを含む段部が形成された一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成するとともに、両厚肉被接合材１，１の中間面２ｂ，２ｂと内側端面２ｃ，２ｃとで形成される凹部に該凹部と同一の断面形状の接続板５を装入する。
次に図１１（Ｂ）に示すように、下方から摩擦攪拌接合用のツールを挿入し、突合せ部３を摩擦攪拌接合して接合線Ｗ１を形成する。
続いて図１１（Ｃ）に示すように、上方から摩擦攪拌接合用のツールを挿入し、突合せ部６，６を摩擦攪拌接合して接合線Ｗ２，Ｗ２を形成する。
最後に図１１（Ｄ）に示すように、上方から摩擦攪拌用のツールを挿入し、凹部の底面（中間面２ｂ，２ｂ）と接続板５の底面との境界面７を摩擦攪拌して一体化させ、境界面７を含む攪拌部Ｗ３を形成する。摩擦攪拌用のツールは下から挿入することも可能である。
【００２９】
なお、図１１（Ａ）の後の図１１（Ｂ）〜（Ｄ）の順序は任意に変更可能であり、最終的に接合線Ｗ１，Ｗ２と攪拌部Ｗ３を形成できればよい。
【００３０】
＜第六実施形態＞
図１２は本発明に係る接合方法の第六実施形態の各工程を表す断面図である。本実施形態では、各厚肉被接合材１，１の接合端に沿って上面側に二段の段部２，２’が形成されている。
図１２（Ａ）に示すように、厚肉被接合材１，１は厚さ１０〜１５ｍｍで、それぞれの接合端に沿って二段の段部２，２’が形成されている。段部２は外側端面２ａと第一中間面２ｂと第一内側端面２ｃとで形成され、段部２’は第一内側端面２ｃと第二中間面２ｂ’と第二内側端面２ｃ’とで形成されている。そして、このような一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成する。すると、第一中間面２ｂ，２ｂと第一内側端面２ｃ，２ｃとで幅狭の凹部４が形成され、第二中間面２ｂ’，２ｂ’と第二内側端面２ｃ’，２ｃ’とで幅広の凹部４’が形成される。
続いて図１２（Ｂ）に示すように、凹部４に該凹部４と同一断面形状の接続板５を装入した上で、上記各実施形態と同様に、突合せ部３，６，６の摩擦攪拌接合による接合線Ｗ１，Ｗ２を形成するとともに、境界面７の摩擦攪拌により攪拌部Ｗ３を形成する。
最後に図１２（Ｃ）に示すように、凹部４’に該凹部４’と同一断面形状の接続板５’を装入した上で、上記各実施形態と同様に、接続板５’と各厚肉被接合材１，１の第二内側端面２ｃ’，２ｃ’との間の突合せ部６’，６’を摩擦攪拌接合するとともに、接続板５’の底面と凹部４’の底面（第二中間面２ｂ’，２ｂ’及び接続板５の上面）との境界面７’を摩擦攪拌して攪拌部Ｗ３を形成する。
【００３１】
＜第七実施形態＞
図１３は本発明に係る接合方法の第七実施形態の各工程を表す断面図である。本実施形態では、各厚肉被接合材１，１の接合端に沿って形成された段部２が、底広凹溝２ｄを有する。つまり図１３（Ａ）に示すように、段部２は、外側端面２ａと中間面２ｂと底広凹溝２ｄと内側端面２ｃとで形成されている。
そしてまず同図に示すように、これら一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、該突合せ部３を摩擦攪拌接合して接合線Ｗ１を形成する。
次に図１３（Ｂ）に示すように、両厚肉被接合材１，１の中間面２ｂ，２ｂと内側端面２ｃ，２ｃと底広凹溝２ｄ，２ｄとで形成される凹部４に該凹部４と同一断面形状の接続板５をスライド装入した後、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの間の突合せ部６，６を摩擦攪拌接合する。接続板５は、底広凹溝２ｄ，２ｄに嵌合する底広凸条５ｄ，５ｄを有している。
最後に図１３（Ｃ）に示すように、接続板５の上方から摩擦攪拌用のツールを挿入し、凹部４の底面（中間面２ｂ，２ｂ及び底広凹溝２ｄ，２ｄの底面）と接続板５の底面との境界面７を摩擦攪拌して攪拌部Ｗ３を形成する。
【００３２】
このように、本発明における境界面７は、一水平面に限定されるわけではなく、二段以上の水平面を有するものであってもよいなど、その態様は任意である。また、図１３（Ａ）〜（Ｃ）の順序は適宜変更可能である。
【００３３】
＜第八実施形態＞
図１４は本発明に係る接合方法の第八実施形態の各工程を表す断面図である。本実施形態では、接合すべき一対の厚肉被接合材のうちの一方の厚肉被接合材１の厚さが他方の厚肉被接合材１’の厚さよりも大きくなっている。つまり図１４（Ａ）に示すように、一方の厚肉被接合材１の接合端には、外側端面２ａと中間面２ｂと内側端面２ｃとからなる段部２が形成されており、他方の厚肉被接合材１’の接合端には、外側端面２ａと中間面２ｂと内側端面２ｃ’とからなる段部２’が形成されているが、内側端面２ｃの高さは内側端面２ｃ’の高さよりも大きい。
そしてまず同図に示すように、これら一対の厚肉被接合材１，１’の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、該突合せ部３を摩擦攪拌接合して接合線Ｗ１を形成する。
次に図１４（Ｂ）に示すように、両厚肉被接合材１，１’の中間面２ｂ，２ｂと内側端面２ｃ，２ｃ’とで形成される凹部４に該凹部４と相似断面形状の接続板５を装入した後、接続板５と各厚肉被接合材１，１’の内側端面２ｃ，２ｃ’との間の突合せ部６，６’を摩擦攪拌接合する。接続板５の上面は、凹部４に装入されたときにそれぞれ厚肉被接合材１，１’の上面と同一高さとなるような第一水平面５ａ、第二水平面５ｂと、第一水平面５ａと第二水平面５ｂとをつなぐ斜面５ｃとで形成されている。
最後に図１４（Ｃ）に示すように、接続板５の上方から摩擦攪拌用のツールを挿入し、凹部４の底面（中間面２ｂ，２ｂ）と接続板５の底面との境界面７を摩擦攪拌して攪拌部Ｗ３を形成する。
【００３４】
このように本発明は、一対の厚肉被接合材の厚さが異なる場合にも対応可能である。また、図１４（Ａ）〜（Ｃ）の順序は適宜変更可能である。
【００３５】
＜第九実施形態＞
図１５は本発明に係る接合方法の第九実施形態の各工程を表す断面図である。本実施形態では、各厚肉被接合材１，１の接合端に沿って上下両側にそれぞれ段部２，２’が形成されている。
図１５（Ａ）に示すように、厚肉被接合材１，１は厚さ１０〜１５ｍｍで、それぞれ接合端に沿って上段の段部２と下段の段部２’が形成されている。上段の段部２は外側端面２ａと第一中間面２ｂと第一内側端面２ｃとで形成され、下段の段部２’は外側端面２ａと第二中間面２ｂ’と第二内側端面２ｃ’とで形成されている。そして、このような一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、該突合せ部３を摩擦攪拌接合して接合線Ｗ１を形成する。
次に図１５（Ｂ）に示すように、両厚肉被接合材１，１の第一中間面２ｂ，２ｂと第一内側端面２ｃ，２ｃとで形成される凹部４に該凹部４と同一断面形状の接続板５を装入した後、接続板５と各厚肉被接合材１，１の第一内側端面２ｃ，２ｃとの間の突合せ部６，６を摩擦攪拌接合して接合線Ｗ２，Ｗ２を形成する。また、両厚肉被接合材１，１の第二中間面２ｂ’，２ｂ’と第二内側端面２ｃ’，２ｃ’とで形成される凹部４’に該凹部４’と同一断面形状の接続板５’を装入した後、接続板５’と各厚肉被接合材１，１の第二内側端面２ｃ’，２ｃ’との間の突合せ部６’，６’を摩擦攪拌接合して接合線Ｗ２，Ｗ２を形成する。
最後に図１５（Ｃ）に示すように、接続板５の底面と凹部４の底面（第一中間面２ｂ，２ｂ）との境界面７を摩擦攪拌して攪拌部Ｗ３を形成するとともに、接続板５’の底面（同図では上面）と凹部４の底面（第二中間面２ｂ’，２ｂ’）との境界面７’を摩擦攪拌して攪拌部Ｗ３を形成する。
【００３６】
このように本発明は、各厚肉被接合材の接合端に沿って上下両側に段部が形成されている場合にも対応可能である。また、図１５（Ｂ），（Ｃ）の順序は適宜変更可能である。
【００３７】
＜第十実施形態＞
図１６は本発明に係る接合方法の第十実施形態の各工程を表す断面図である。
図１６（Ａ）に示すように、厚肉被接合材１，１は厚さ１０〜１５ｍｍで、接合端に沿って段部２が形成されている。段部２は高さの大きな（５〜１０ｍｍの）外側端面２ａと中間面２ｂと高さの小さな（５ｍｍ以下の）内側端面２ｃとで形成されている。そして、このような一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、該突合せ部３に上下両方から摩擦攪拌接合用のツールを装入して摩擦攪拌接合を行い、接合線Ｗ１，Ｗ１を形成する。
次に図１６（Ｂ）に示すように、両厚肉被接合材１，１の中間面２ｂ，２ｂと内側端面２ｃ，２ｃとで形成される凹部４に該凹部４と同一断面形状の接続板５を装入した後、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの間の突合せ部６，６を摩擦攪拌接合して接合線Ｗ２，Ｗ２を形成する。
最後に図１６（Ｃ）に示すように、接続板５の底面と凹部４の底面（中間面２ｂ，２ｂ）との境界面７を摩擦攪拌して攪拌部Ｗ３を形成する。
【００３８】
このように本発明は、各厚肉被接合材の接合端に沿って形成された段部の外側端面の高さが大きい場合にも対応可能である。また、図１６（Ｂ），（Ｃ）の順序は適宜変更可能である。
【００３９】
＜第十一実施形態＞
図１７は本発明に係る接合方法の第十一実施形態の各工程を表す断面図である。本実施形態では、各厚肉被接合材１，１の接合端に沿って上下両面側にそれぞれ段部２，２’が形成されている。
図１７（Ａ）に示すように、厚肉被接合材１，１は厚さ１５〜２０ｍｍで、それぞれ接合端に沿って上段の段部２と下段の段部２’が形成されている。上段の段部２は外側端面２ａと第一中間面２ｂと第一内側端面２ｃとで形成され、下段の段部２’は外側端面２ａと第二中間面２ｂ’と第二内側端面２ｃ’とで形成されている。外側端面２ａの高さは５〜１０ｍｍである。そして、このような一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、該突合せ部３に上下両方から摩擦攪拌接合用のツールを装入して摩擦攪拌接合を行い、接合線Ｗ１，Ｗ１を形成する。
次に図１７（Ｂ）に示すように、両厚肉被接合材１，１の第一中間面２ｂ，２ｂと第一内側端面２ｃ，２ｃとで形成される凹部４に該凹部４と同一断面形状の接続板５を装入した後、接続板５と各厚肉被接合材１，１の第一内側端面２ｃ，２ｃとの間の突合せ部６，６を摩擦攪拌接合して接合線Ｗ２，Ｗ２を形成する。また、両厚肉被接合材１，１の第二中間面２ｂ’，２ｂ’と第二内側端面２ｃ’，２ｃ’とで形成される凹部４’に該凹部４’と同一断面形状の接続板５’を装入した後、接続板５’と各厚肉被接合材１，１の第二内側端面２ｃ’，２ｃ’との間の突合せ部６’，６’を摩擦攪拌接合して接合線Ｗ２，Ｗ２を形成する。
最後に図１７（Ｃ）に示すように、接続板５の底面と凹部４の底面（第一中間面２ｂ，２ｂ）との境界面７を摩擦攪拌して攪拌部Ｗ３を形成するとともに、接続板５’の底面（同図では上面）と凹部４の底面（第二中間面２ｂ’，２ｂ’）との境界面７’を摩擦攪拌して攪拌部Ｗ３を形成する。
【００４０】
このように本発明は、各厚肉被接合材の接合端に沿って上下両側に段部が形成され、外側端面の高さが大きい場合にも対応可能である。また、図１７（Ｂ），（Ｃ）の順序は適宜変更可能である。
【００４１】
＜第十二実施形態＞
図１８は本発明に係る接合方法の第十二実施形態の各工程を表す断面図である。本実施形態は基本的に第一乃至第五の実施形態と同じであるが、各厚肉被接合材が曲面板材である点のみにおいて異なる。
つまり、図１８（Ａ）に示すように、それぞれの接合端に沿って外側端面２ａと中間面２ｂと内側端面２ｃとを含む段部２が形成された一対の厚肉被接合材１，１の外側端面２ａ，２ａ同士を突き合わせて突合せ部３を形成し、該突合せ部３を摩擦攪拌接合して接合線Ｗ１を形成する。中間面２ｂは曲面となっている。
次に図１８（Ｂ）に示すように、両厚肉被接合材１，１の中間面２ｂ，２ｂと内側端面２ｃ，２ｃとで形成される凹部４に該凹部４と同一断面形状の接続板５を装入した後、接続板５と各厚肉被接合材１，１の内側端面２ｃ，２ｃとの間の突合せ部６，６を摩擦攪拌接合して接合線Ｗ２，Ｗ２を形成する。
最後に図１８（Ｃ）に示すように、凹部４の底面（中間面２ｂ，２ｂ）と接続板５の底面との境界面７を摩擦攪拌して一体化させ、境界面７を含む攪拌部Ｗ３を形成する。
【００４２】
このように本発明は、各厚肉被接合材が曲面板状である場合にも対応可能である。また、図１８（Ａ）〜（Ｃ）の順序は適宜変更可能である。
【００４３】
＜ツールについて＞
以上の各実施形態で用いた摩擦攪拌用のツール２０は、適宜の変更が可能である。たとえば図１９に示した摩擦攪拌用のツール２０’は、回転円柱体２１の底面である表面押え部２２の中心からずれた位置から（偏心して）円柱形の攪拌ピン２３が垂下している。このように攪拌ピン２３が回転円柱体２１に対して偏心していると、回転円柱体２１をその軸まわりに回転させたときに、攪拌ピン２３が自転するとともに回転円柱体２１の軸まわりに公転するので、境界面７の攪拌作用が増大する。攪拌ピン２３の周面には、ネジ状の小さな摩擦攪拌翼２５が形成されているので、この摩擦攪拌翼２５を利用して攪拌ピン２３を回転円柱体２２に固定することができ、攪拌ピンの突出長さも容易に調節可能である。
【００４４】
さらにまた、図２０（Ａ）〜（Ｅ）に示したツールを用いることも可能である。図２０（Ａ）のツール２０Ａは、回転円柱体２１の底面である表面押え部２２の中心からずれた位置から（偏心して）多角形柱体状の攪拌ピン２３が垂下し、表面押え部２２の周縁から攪拌ピン２３の基端部に向かって渦巻状に突出する凸条２４が形成されたものである。図２０（Ｂ）〜（Ｅ）のツール２０Ｂ〜２０Ｅはいずれも、回転円柱体２１の底面である表面押え部２２の中心からずれた位置から（偏心して）略円柱形の攪拌ピン２３が垂下しており、さらに、ツール２０Ｂは攪拌ピン２３の底面に十字形の凸条２６が形成されたもの、ツール２０Ｃは攪拌ピン２３の底面に多数の細かい直方体形状の突起２７，２７，…が格子状に形成されたもの、ツール２０Ｄは攪拌ピン２３の底面に同心円状にリング状の突起２８，２８，…が形成されたもの、ツール２０Ｅは攪拌ピン２３の周面の底面付近に複数の凹溝２９，２９，…が形成されたものである。これらのツールはいずれも境界面７の攪拌作用を増大させたものである。
【００４５】
なお、上記各実施形態では、摩擦攪拌接合用のツール１０と摩擦攪拌用のツール２０を別々のものとしたが、もちろん同一のツールで摩擦攪拌接合と摩擦攪拌の双方を行うようにしてもよい。
【００４６】
【発明の効果】
以上のように、本発明によれば、接続板の底面と凹部の底面との間の隙間や、接続板と各厚肉被接合材の内側端面との突合せ部を摩擦攪拌接合してなる接合線の内部にトンネル状空洞欠陥を残さずに、気密性の高い厚肉被接合材の接合構造を得ることができる。
【図面の簡単な説明】
【図１】（Ａ）〜（Ｄ）はそれぞれ本発明に係る接合方法の第一実施形態の各工程を表す断面図であり、（ｃ）は（Ｃ）のｃ−ｃ断面図、（ｄ）は（Ｄ）のｄ−ｄ断面図である。
【図２】（Ａ）〜（Ｅ）はそれぞれ本発明に係る接合方法の第一実施形態の各工程を表す断面図である。
【図３】本発明に係る接合方法の第一実施形態の一工程を表す斜視図である。
【図４】（Ａ）は図３のａ−ａ断面図であり、（Ｂ）は図３の平面図である。
【図５】（Ａ）は摩擦攪拌用ツールの側面図、（Ｂ）は（Ａ）の底面図、（Ｃ）は（Ｂ）のＣ−Ｃ断面図である。
【図６】（Ａ），（Ｂ）はそれぞれ、摩擦攪拌ツールの移動軌跡の別の例を表す平面図である。
【図７】（Ａ），（Ｂ）はそれぞれ、摩擦攪拌ツールの移動完了後の状態を表す断面図である。
【図８】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第二実施形態の各工程を表す断面図である。
【図９】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第三実施形態の各工程を表す断面図である。
【図１０】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第四実施形態の各工程を表す断面図である。
【図１１】（Ａ）〜（Ｄ）はそれぞれ本発明に係る接合方法の第五実施形態の各工程を表す断面図である。
【図１２】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第六実施形態の各工程を表す断面図である。
【図１３】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第七実施形態の各工程を表す断面図である。
【図１４】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第八実施形態の各工程を表す断面図である。
【図１５】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第九実施形態の各工程を表す断面図である。
【図１６】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第十実施形態の各工程を表す断面図である。
【図１７】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第十一実施形態の各工程を表す断面図である。
【図１８】（Ａ）〜（Ｃ）はそれぞれ本発明に係る接合方法の第十二実施形態の各工程を表す断面図である。
【図１９】（Ａ）は摩擦攪拌用ツールの別の例を表す斜視図であり、（Ｂ）は同断面図である。
【図２０】（Ａ）〜（Ｅ）はそれぞれ摩擦攪拌用ツールの別の例を表す斜視図である。
【図２１】（Ａ）〜（Ｄ）は従来の接合方法の各工程を表す断面図である。
【図２２】図２０（Ｄ）の部分拡大斜視図である。
【符号の説明】
１ … 厚肉被接合材
２ … 段部
２ａ … 外側端面
２ｂ … 中間面
２ｃ … 内側端面
２ｄ … 底広凹溝
３ … 突合せ部
４ … 凹部
５ … 接続板
５ａ … 第一水平面
５ｂ … 第二水平面
５ｃ … 斜面
５ｄ … 底広凸条
６ … 突合せ部
７ … 境界面
８ … 隙間
１０ … （摩擦攪拌接合用の）ツール
１１ … 回転円柱体
１２ … 表面押え部
１３ … 攪拌ピン
２０ … （摩擦攪拌用の）ツール
２１ … 回転円柱体
２２ … 表面押え部
２３ … 攪拌ピン
２４ … 凸条
２５ … 摩擦攪拌翼
２６ … 凸条
２７ … 突起
２８ … 突起
２９ … 凹溝
Ｗ１，Ｗ２ … 接合線
Ｗ３ … 攪拌部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and a structure for joining thick workpieces without gaps.
[0002]
[Prior art]
Patent Literature 1 discloses a method of friction stir welding thick workpieces. As a procedure, first, as shown in FIG. 21A, a stepped portion 2 composed of an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c is attached to each joint end of the pair of thick materials 1 and 1 to be joined. It is formed. Then, as shown in FIG. 21B, the outer end surfaces 2a, 2a of the pair of thick workpieces 1, 1 are butted against each other to form a butt portion 3, and along the butt portion 3, the friction stir welding is performed. By inserting the tool 10 and performing friction stir welding, the thick workpieces 1 and 1 are joined to form a joining line W1. Next, as shown in FIG. 21 (C), a concave portion 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the both thick workpieces 1, 1 is identical or similar to the concave portion 4. The connecting plate 5 having a sectional shape is inserted. Finally, as shown in FIG. 21 (D), a tool 10 for friction stir welding is inserted along abutting portions 6, 6 between the connection plate 5 and the inner end surfaces 2c, 2c of the thick workpieces 1, 1. Then, by performing friction stir welding, respectively, welding lines W2 and W2 are formed. In this way, by performing friction stir welding in two steps in the thickness direction of the material to be joined, it is possible to join materials having a large thickness that cannot be handled by existing welding tools.
[0003]
[Patent Document 1]
Japanese Patent No. 3307330 ([0013]-[0018], FIG. 1-2)
[0004]
[Problems to be solved by the invention]
However, in the joint structure joined by the above-described conventional method, as shown in FIG. 22, the bottom surface of the connection plate 5 and the bottom surface of the concave portion 4 (the intermediate surfaces 2b and 2b of the thick materials 1 and 1) are connected. May be left unbonded and the gap 8 may remain. In addition, a tunnel-shaped cavity continuous in the traveling direction of the tool is provided inside a joining line W2 formed by friction stir welding of a joining portion 6 between the connection plate 5 and the inner end surfaces 2c, 2c of the thick workpieces 1, 1. The defect 9 may remain. Since the gap 8 and the tunnel-like cavity defect 9 reduce the airtightness of the portion, when this joint structure is used, for example, in a vacuum processing container or the like of a semiconductor manufacturing apparatus, a leak is likely to occur. There is a problem that it cannot be maintained in an ultra-high vacuum state for a long time.
[0005]
The present invention has been made in view of the above circumstances, and a method of joining a thick material to be joined (hereinafter, simply referred to as a “joining method”) and a thick material to join the thick materials to be joined without gaps. It proposes a joining structure of materials (hereinafter, simply referred to as “joining structure”).
[0006]
[Means for Solving the Problems]
That is, the invention according to claim 1 abuts the outer end surfaces of a pair of thick workpieces formed with a stepped portion including an outer end surface, an intermediate surface, and an inner end surface along each joint end, A first step of friction stir welding the butted portion, and a connecting plate having the same or similar cross-sectional shape as the concave portion is inserted into a concave portion formed by an intermediate surface and an inner end surface of the thick workpieces. A second step, and a third step of friction stir welding the butted portions of the connection plate and the inner end surfaces of the thick workpieces, respectively, and friction stir a boundary surface between the connection plate and the bottom surface of the concave portion. And a joining method.
In addition, the invention according to claim 3 abuts the outer end surfaces of a pair of thick materials to be joined having a stepped portion including an outer end surface, an intermediate surface, and an inner end surface along each joint end. A first step of inserting a connection plate having the same or similar cross-sectional shape as the concave portion into a concave portion formed by an intermediate surface and an inner end surface of the thick material to be bonded; Abutting portions formed by abutting outer end surfaces of the members, and abutting portions between the connecting plate and the inner end surfaces of the thick workpieces, respectively, are subjected to friction stir welding, respectively, and the bottom surfaces of the connecting plate and the recess are provided. And a second step of friction-stirring a boundary surface between the two.
Further, according to the invention according to claim 7, a stepped portion including an outer end surface, an intermediate surface, and an inner end surface is formed along each joint end, and the pair of thick joined members whose outer end surfaces abut against each other. A connection plate having the same or similar cross-sectional shape as the concave portion, which is inserted into a concave portion formed by an intermediate surface and an inner end surface of the both thick bonded members. Abutting portions formed by abutting outer surfaces of the connecting plates, and butting portions of the connecting plate and inner end surfaces of the thick workpieces are friction stir welded, respectively, and the bottom surfaces of the connecting plate and the concave portion And the boundary surface is friction-stirred.
[0007]
According to such a joining method or joining structure, the boundary surface between the connecting plate and the bottom surface of the concave portion, which is left unjoined in the conventional joining method or joining structure, is integrated by friction stirring, so that A highly airtight joint with no gap can be formed.
[0008]
Further, the invention according to claim 2 is, in the third step of the joining method according to claim 1, after performing a friction stir welding of a butt portion between the connection plate and the inner end surface of each of the thick workpieces, It is characterized in that a boundary surface between the connection plate and the bottom surface of the concave portion is friction-stirred.
According to a fourth aspect of the present invention, in the second step of the joining method according to the third aspect, a butt portion formed by abutting outer end surfaces of the pair of thick materials to be joined, After performing friction stir welding on the butted portion with the inner end surface of the thick workpiece, friction stir is performed on the boundary surface between the connection plate and the bottom surface of the concave portion.
[0009]
In such a joining method, before friction stir processing on a boundary surface between the connecting plate and the bottom surface of the concave portion, a butt portion formed by abutting outer end surfaces of a pair of thick joined materials, and the connecting plate and each thick joined material. Since friction stir welding has been completed for the butted portion with the inner end surface of the material, positioning and fixing of the connection plate during friction stirring is easy.
[0010]
According to a fifth aspect of the present invention, in the joining method according to any one of the first to fourth aspects, friction stir of a boundary surface between the connection plate and a bottom surface of the concave portion is performed by the connection method. The method is characterized in that it is applied across the butted portion of the thick material to be joined with the inner end face.
According to an eighth aspect of the present invention, in the joining structure according to the seventh aspect, friction stir of a boundary surface between the connection plate and the bottom surface of the concave portion is performed inside the connection plate and each of the thick workpieces. It is characterized by being provided across the abutting portion with the end face.
[0011]
According to such a joining method or a joining structure, friction stir is performed across the abutting portion between the connection plate and the inner end face of each thick material to be joined. Even if it does, this tunnel-like cavity defect can be divided to further improve the airtightness.
[0012]
According to a sixth aspect of the present invention, in the joining method according to any one of the first to fifth aspects, when the interface between the connection plate and the bottom surface of the concave portion is friction-stirred, the connection is performed. The friction stir tool is moved from the center of the plate toward the peripheral edge.
[0013]
According to such a joining method, the friction stir tool is moved from the center of the connection plate toward the peripheral edge at the time of friction stirring, so that joining can be performed without involving air remaining on the boundary surface. When joining from the periphery to the center, a tunnel-like defect occurs due to air entrainment.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same elements will be denoted by the same reference symbols, without redundant description. It is also assumed that a thick aluminum plate is used as the thick material to be joined and the joining capacity of the friction stir welding apparatus is 5 mm.
[0015]
<First embodiment>
1 to 4 are cross-sectional views showing each step of the first embodiment of the bonding method according to the present invention.
First, as shown in FIG. 1 (A), a pair of thick materials to be joined 1, 1 to be joined are brought into surface contact with respective outer end surfaces 2a, 2a to form a butted portion 3, and then not shown. Restrain with a jig. Each thick workpiece 1 has a thickness of 5 to 10 mm, and a step 2 is formed along each of the bonding ends. The step portion 2 is formed to include an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c. When the outer end surfaces 2a, 2a of the pair of thick workpieces 1, 1 abut against each other, a recess 4 is formed by the continuous two intermediate surfaces 2b, 2b and the pair of opposing inner end surfaces 2c, 2c. Is done. The thick workpiece 1 is a rolled aluminum plate (AA5052 alloy, AA6061 alloy) that is cut or processed, or aluminum (JIS: A6063-T5 or T6, etc.) in which the step portion 2 is integrally formed in advance. Is used.
[0016]
Next, as shown in FIG. 1B, a tool 10 for friction stir welding is set on the butting portion 3. The tool 10 is made of tool steel, and includes a rotating cylindrical body 11 and a stirring pin 13 that is coaxially suspended from the center of a slightly curved and concave surface holding portion 12 on the bottom surface. The stirring pin 13 is slightly shorter than the height of the outer end face 2a and the inner end face 2c of the thick workpiece 1 and has a small screw-shaped friction stirrer blade (not shown) formed on its peripheral surface. Then, as shown in FIGS. 1C and 1C, the center axes of the rotating cylindrical body 11 and the stirring pin 13 are slightly inclined along the butted portions 3 of the thick workpieces 1, 1. The tool 10 is advanced toward the butting portion 3 while rotating the tool 10 by a motor (not shown). The rotation speed of the tool 10 is appropriately selected within a range of 300 to 5000 rpm. The thick materials 1 and 1 are restrained in advance so as not to move in the longitudinal direction and the width direction.
[0017]
Next, as shown in the figure, the tool 10 is pressed against each thick workpiece 1 in the vertical direction, and the stirring pin 13 is pushed in until the entire surface holding portion 12 reaches the surface of the intermediate surfaces 2b, 2b. In this state, the tool 10 is moved in the direction opposite to the inclined direction (to the left in FIG. 1C). This feed speed is appropriately selected within a range of 0.02 to 2 m / min. As the tool 10 rotates and moves, the metal in the vicinity of the butting portion 3 is heated and plasticized by the stirring pin 13, and the metal in the horizontal and vertical directions between the left and right thick workpieces 1 and 1 of the butting portion 3. Fluidized.
[0018]
In addition, the fluidized metal is given a constant pressure to the flow in the vertical direction by the surface pressing portion 12 of the tool 10 and is prevented from scattering outside from near the surface of the butting portion 3. As a result, as shown in FIGS. 1D and 1D, after the tool 10 has passed, the fluidized metal solidifies from the fluidized state to become a joining line W1 having a substantially semi-elliptical cross section. . Although the surface of the joining line W1 is slightly recessed by the surface pressing portion 12 by the width of the diameter, the joining line W1 is continuous at a required length along the butt portion 3 and has a flat surface. .
[0019]
Next, as shown in FIGS. 2A and 2B, a concave portion formed by the continuous two intermediate surfaces 2b, 2b of the thick workpieces 1, 1 and a pair of opposed inner end surfaces 2c, 2c. 4, an aluminum connecting plate 5 having the same cross section as the concave portion 4 is inserted, and abutting portions 6 are formed between the connecting plate 5 and the inner end surfaces 2 c, 2 c of the thick workpieces 1, 1. 6 is formed. Then, as shown in FIGS. 2C and 2D, friction stir welding is sequentially performed along the butting portions 6 and 6 using the tool 10 in the same manner as described above. As a result, as shown in FIG. 2 (E), a pair of parallel joining lines W2, W2 for joining the connecting plate 5 and the thick workpieces 1, 1 are formed along the butted portions 6, 6. Is done.
[0020]
Next, as shown in FIGS. 3 and 4A and 4B, a friction stir tool 20 is inserted from above the connection plate 5 and connected to the bottom surface of the recess 4 (intermediate surfaces 2b, 2b). The tool 20 is moved along the connection plate 5 while integrating the boundary surface 7 with the bottom surface of the plate 5 by friction stirring. As shown in FIG. 5, the friction stir tool 20 is made of tool steel, and includes a rotating cylindrical body 21 and a stirring pin 23 which coaxially hangs from the center of the surface pressing portion 22 which is a horizontal bottom surface. I have. The surface pressing portion 22 is provided with a spiral ridge 24 that protrudes in a substantially spiral shape from the periphery to the base end of the stirring pin 23 in substantially two rounds when viewed from the bottom. The protruding ridges 24 are formed in such a direction that the plasticized metal is forcibly collected toward the base end of the stirring pin 23 when the tool 20 rotates in the direction indicated by the arrow in FIG. Have been. A small screw-shaped friction stirrer blade 25 is formed on the peripheral surface of the stirring pin 23. When the tool 20 rotates in the direction indicated by the arrow in FIG. 5B, the friction stirrer blade 25 moves the plasticized metal upward from below (from the tip of the stirring pin 23 to the surface pressing portion 22). It is formed in such a way that it is forcibly collected.
[0021]
Then, the center axes of the rotating cylindrical body 21 and the stirring pin 23 are set in a direction perpendicular to the surface of the connecting plate 5 or slightly inclined, and the tool 20 is rotated toward the connecting plate 5 by a motor (not shown). With the rotation of the tool 20, the metal near the boundary surface 7 between the bottom surface (intermediate surfaces 2b, 2b) of the concave portion 4 and the bottom surface of the connection plate 5 is heated by the stirring pin 23 and plasticized, and the metal is also horizontal at this portion. And the metal in the vicinity of the bottom surface of the concave portion 4 is integrated with the metal of the thick material 1 and 1 near the bottom surface of the connection plate 5 to close the fine gap at the boundary surface 7. . Then, the tool 20 is sequentially moved along the entire surface of the connection plate 5 while the surface of the connection plate 5 is pressed by the surface pressing portion 22, so that all the fine gaps on the boundary surface 7 can be closed.
[0022]
Here, as shown in FIGS. 3 and 4B, the tool 20 is moved so as to draw a continuous trajectory of a spiral pattern in plan view from near the center of the connection plate 5 toward the peripheral edge. In this case, the air remaining on the boundary surface can be joined without being entangled in the joining portion, and a hole that is inevitable when the tool 20 is pulled out can be prevented from being left in the connecting plate 5.
Of course, the movement locus of the tool 20 is not limited to this. For example, as shown in FIG. 6A, the tool 20 may be moved in a direction parallel to the joining line W2 while repeating a U-turn. As shown in FIG. 6B, the U-turn may be repeated to move in the direction orthogonal to the joining line W2, or a movement pattern other than these may be used. Although it may be continuous or discontinuous, it is important to break the continuity of the gap of the boundary surface 7 in the direction of the joining line W2 so that the tool 20 passes over the entire surface of the connection plate 5 evenly. .
[0023]
When the friction stir by the tool 20 is completed, as shown in FIG. 7A, the connection plate 5 becomes a stirring portion W3 formed after the tool 20 passes. Since the stirring portion W3 is formed so as to include the boundary surface 7, the bottom surface of the concave portion 4 and the metal of the connection plate 5 are integrated, and a bonding structure in which the minute gap of the boundary surface 7 is closed can be obtained. .
In addition, as shown in FIG. 7 (B), abutment portions 6 and 6 (joining lines W2 and W2) between connecting plate 5 and inner end faces 2c and 2c of thick materials 1 and 1 are traversed. When the tool 20 is moved, not only the gap between the boundary surfaces 7 is closed, but also the tunnel-like cavity defects in the joining lines W2 and W2 are separated by the stirring portion W3, so that a more airtight joining structure is obtained. Become.
[0024]
<Second embodiment>
FIG. 8 is a sectional view illustrating each step of the second embodiment of the joining method according to the present invention. This embodiment is basically the same as the first embodiment, but differs only in the order of the friction stir welding of the butting portions 6 and 6 and the friction stirring of the boundary surface 7.
In other words, first, as shown in FIG. 8A, a pair of thick workpieces 1 having a stepped portion 2 including an outer end face 2a, an intermediate face 2b, and an inner end face 2c are formed along respective joining ends. The butting portions 3 are formed by abutting the outer end surfaces 2a of the first member 1 with each other, and the butting portions 3 are friction stir welded to form a joining line W1.
Next, as shown in FIG. 8 (B), a connection having the same cross-sectional shape as that of the concave portion 4 is formed in the concave portion 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the both thick workpieces 1, 1. After the plate 5 is loaded, a friction stir tool 20 is inserted from above the connection plate 5 to friction stir the boundary surface 7 between the bottom surface (intermediate surfaces 2b, 2b) of the recess 4 and the bottom surface of the connection plate 5. Then, the agitation unit W3 including the boundary surface 7 is formed.
Finally, as shown in FIG. 8C, the butting portions 6, 6 between the connecting plate 5 and the inner end surfaces 2c, 2c of the thick workpieces 1, 1 are friction stir welded sequentially or simultaneously.
[0025]
Similarly to the first embodiment, the joint structure obtained in this manner also has a highly airtight structure in which the bottom surface of the concave portion 4 and the metal of the connection plate 5 are integrated, and the minute gap at the boundary surface 7 is closed. Has become.
Note that, unlike the first embodiment, when the boundary surface 7 between the bottom surface of the concave portion 4 and the bottom surface of the connection plate 5 is integrated by friction stirring, the connection plate 5 is firmly restrained so as not to move. There is a need.
[0026]
<Third embodiment>
FIG. 9 is a cross-sectional view illustrating each step of the third embodiment of the bonding method according to the present invention. This embodiment is basically the same as the second embodiment, but differs only in the insertion direction of the tool at the time of friction stirring of the boundary surface 7.
In other words, first, as shown in FIG. 9A, a pair of thick workpieces 1 having a stepped portion 2 including an outer end face 2a, an intermediate face 2b, and an inner end face 2c are formed along respective joining ends. The butting portions 3 are formed by abutting the outer end surfaces 2a of the first member 1 with each other, and the butting portions 3 are friction stir welded to form a joining line W1.
Next, as shown in FIG. 9 (B), a connection having the same cross-sectional shape as that of the concave portion 4 is formed in the concave portion 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the both thick workpieces 1, 1. After the plate 5 is inserted, a friction stir tool 20 is inserted from below the connection plate 5 (on the side of the joining line W1), and a boundary between the bottom surface of the recess 4 (the intermediate surfaces 2b, 2b) and the bottom surface of the connection plate 5 is formed. The surfaces 7 are integrated by frictional stirring to form a stirring portion W3 including the boundary surface 7.
Finally, as shown in FIG. 9 (C), the butting portions 6, 6 between the connecting plate 5 and the inner end surfaces 2c, 2c of the thick workpieces 1, 1 are friction stir welded sequentially or simultaneously.
[0027]
<Fourth embodiment>
FIG. 10 is a sectional view illustrating each step of the fourth embodiment of the joining method according to the present invention. This embodiment is basically the same as the first embodiment, but differs only in the order of the friction stir welding of the butting portions 6 and 6 and the friction stirring of the boundary surface 7.
That is, first, as shown in FIG. 10A, a pair of thick workpieces 1 having a stepped portion 2 including an outer end face 2a, an intermediate face 2b, and an inner end face 2c are formed along respective joining ends. The butting portions 3 are formed by abutting the outer end surfaces 2a of the first member 1 with each other, and the butting portions 3 are friction stir welded to form a joining line W1.
Next, as shown in FIGS. 10 (B) and 10 (C), the concave portions 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the thick workpieces 1, 1 are the same as the concave portions 4. After inserting the connecting plate 5 having a cross-sectional shape, a friction stir tool 20 is inserted from above the connecting plate 5, and a boundary surface 7 between the bottom surface (intermediate surfaces 2 b, 2 b) of the recess 4 and the bottom surface of the connecting plate 5 is formed. Of the connecting plate 5 and the inner end surfaces 2c, 2c of the thick workpieces 1, 1 by friction stir welding. That is, the friction stir welding of the butting portions 6 and 6 and the friction stirring of the boundary surface 7 are not distinguished, and the friction stirring is performed so as to include the butting portions 6 and 6, so that the connection plate 5 and each thick welded member are joined. The joining with the materials 1 and 1 and the formation of the stirring section W3 including the boundary surface 7 are performed simultaneously and in parallel. Therefore, it is possible to simplify the operation process.
[0028]
<Fifth embodiment>
FIG. 11 is a sectional view illustrating each step of the fifth embodiment of the bonding method according to the present invention. This embodiment is different from the above embodiments only in the joining timing of the butting portion 3.
That is, first, as shown in FIG. 11A, a pair of thick workpieces 1 and 1 each having a stepped portion including the outer end face 2a, the intermediate face 2b, and the inner end face 2c are formed along the respective joining ends. Abutting portions 3 are formed by abutting the outer end surfaces 2a, 2a of each other, and the recesses formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the thick workpieces 1, 1 are the same as the recesses. Is inserted.
Next, as shown in FIG. 11B, a tool for friction stir welding is inserted from below, and the butting portions 3 are friction stir welded to form a welding line W1.
Subsequently, as shown in FIG. 11C, a tool for friction stir welding is inserted from above, and the butting portions 6, 6 are friction stir welded to form welding lines W2, W2.
Finally, as shown in FIG. 11 (D), a friction stir tool is inserted from above, and the boundary surface 7 between the bottom surface of the concave portion (intermediate surfaces 2b, 2b) and the bottom surface of the connection plate 5 is friction-stirred and integrated. To form the stirring section W3 including the boundary surface 7. The tool for friction stirring can be inserted from below.
[0029]
Note that the order of FIGS. 11B to 11D after FIG. 11A can be arbitrarily changed, as long as the joining lines W1 and W2 and the stirring portion W3 can be finally formed.
[0030]
<Sixth embodiment>
FIG. 12 is a sectional view illustrating each step of the sixth embodiment of the joining method according to the present invention. In the present embodiment, two step portions 2, 2 ′ are formed on the upper surface side along the joining ends of the thick workpieces 1, 1.
As shown in FIG. 12 (A), the thick material to be joined 1, 1 has a thickness of 10 to 15 mm, and two step portions 2, 2 ′ are formed along the respective joining ends. The step portion 2 is formed by the outer end surface 2a, the first intermediate surface 2b, and the first inner end surface 2c, and the step portion 2 'is formed by the first inner end surface 2c, the second intermediate surface 2b', and the second inner end surface 2c '. Is formed. Then, the butting portions 3 are formed by abutting the outer end surfaces 2a, 2a of such a pair of thick materials 1 to 1 to be joined. As a result, a narrow recess 4 is formed between the first intermediate surfaces 2b, 2b and the first inner end surfaces 2c, 2c, and is wider between the second intermediate surfaces 2b ', 2b' and the second inner end surfaces 2c ', 2c'. Is formed.
Subsequently, as shown in FIG. 12 (B), after the connecting plate 5 having the same cross-sectional shape as the concave portion 4 is inserted into the concave portion 4, the friction of the butted portions 3, 6, and 6 is set in the same manner as in the above-described embodiments. The joining lines W1 and W2 are formed by the stir welding, and the stirring section W3 is formed by friction stirring of the boundary surface 7.
Finally, as shown in FIG. 12 (C), after a connection plate 5 'having the same cross-sectional shape as the recess 4' is inserted into the recess 4 ', the connection plate 5' The butted portions 6 ', 6' between the second inner end faces 2c ', 2c' of the thick workpieces 1, 1 are friction stir welded, and the bottom of the connecting plate 5 'and the bottom of the recess 4' (the A boundary portion 7 'between the two intermediate surfaces 2b' and 2b 'and the upper surface of the connection plate 5) is friction-stirred to form a stirring portion W3.
[0031]
<Seventh embodiment>
FIG. 13 is a sectional view illustrating each step of the seventh embodiment of the bonding method according to the present invention. In this embodiment, the step portion 2 formed along the joining end of each of the thick materials 1 and 1 has the wide bottom groove 2d. That is, as shown in FIG. 13A, the stepped portion 2 is formed by the outer end surface 2a, the intermediate surface 2b, the wide bottom groove 2d, and the inner end surface 2c.
First, as shown in the figure, the outer end surfaces 2a, 2a of the pair of thick workpieces 1, 1 are butted against each other to form a butt portion 3, and the butt portion 3 is friction stir welded to form a welding line W1. To form
Next, as shown in FIG. 13 (B), the recesses 4 formed by the intermediate surfaces 2b, 2b, the inner end surfaces 2c, 2c, and the wide bottom grooves 2d, 2d of the both thick workpieces 1, 1 are provided. After the connecting plate 5 having the same cross-sectional shape as the concave portion 4 is slid in, the butting portions 6, 6 between the connecting plate 5 and the inner end surfaces 2c, 2c of the thick workpieces 1, 1 are friction stir welded. . The connection plate 5 has wide bottom convex ridges 5d fitted into the wide bottom concave grooves 2d.
Finally, as shown in FIG. 13 (C), a friction stir tool is inserted from above the connection plate 5 and connected to the bottom surface of the recess 4 (the bottom surfaces of the intermediate surfaces 2b, 2b and the wide bottom grooves 2d, 2d). The boundary portion 7 with the bottom surface of the plate 5 is friction-stirred to form a stirring portion W3.
[0032]
As described above, the boundary surface 7 in the present invention is not limited to a single horizontal plane, and may have two or more horizontal planes. The order of FIGS. 13A to 13C can be changed as appropriate.
[0033]
<Eighth embodiment>
FIG. 14 is a cross-sectional view illustrating each step of the eighth embodiment of the bonding method according to the present invention. In the present embodiment, the thickness of one thick joined material 1 of the pair of thick joined materials to be joined is larger than the thickness of the other thick joined material 1 '. That is, as shown in FIG. 14 (A), a stepped portion 2 composed of an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c is formed at the joint end of one thick material 1 to be joined. At the joining end of the thick joining material 1 ', a step 2' composed of an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c 'is formed. The height of the inner end surface 2c is set to the inner end surface 2c'. Greater than the height of.
First, as shown in the figure, the outer end surfaces 2a, 2a of the pair of thick workpieces 1, 1 'are butted against each other to form a butt portion 3, and the butt portion 3 is friction stir welded and joined to each other. Form W1.
Next, as shown in FIG. 14 (B), the concave portion 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c 'of the thick materials 1 and 1' has a similar cross-sectional shape to the concave portion 4. After the connection plate 5 is inserted, the butting portions 6, 6 'between the connection plate 5 and the inner end faces 2c, 2c' of the thick workpieces 1, 1 'are friction stir welded. The upper surface of the connection plate 5 has a first horizontal surface 5a, a second horizontal surface 5b, and a first horizontal surface 5a which are the same height as the upper surfaces of the thick workpieces 1 and 1 ', respectively, when inserted into the concave portion 4. And a slope 5c connecting the second horizontal plane 5b.
Finally, as shown in FIG. 14 (C), a friction stir tool is inserted from above the connection plate 5, and the boundary surface 7 between the bottom surface (intermediate surfaces 2b, 2b) of the recess 4 and the bottom surface of the connection plate 5 is formed. The stirring portion W3 is formed by friction stirring.
[0034]
As described above, the present invention can cope with the case where the thickness of the pair of thick materials to be joined is different. The order of FIGS. 14A to 14C can be changed as appropriate.
[0035]
<Ninth embodiment>
FIG. 15 is a cross-sectional view illustrating each step of the ninth embodiment of the bonding method according to the present invention. In the present embodiment, steps 2 and 2 ′ are formed on both upper and lower sides along the joining ends of the thick materials 1 and 1, respectively.
As shown in FIG. 15 (A), the thick materials 1 and 1 have a thickness of 10 to 15 mm, and an upper step 2 and a lower step 2 ′ are formed along the joining ends. The upper step 2 is formed of an outer end surface 2a, a first intermediate surface 2b, and a first inner end surface 2c, and the lower step 2 'is formed of an outer end surface 2a, a second intermediate surface 2b', and a second inner end surface 2c '. And formed. Then, the outer end surfaces 2a, 2a of the pair of thick workpieces 1, 1 are butted against each other to form a butt portion 3, and the butt portions 3 are friction stir welded to form a joining line W1.
Next, as shown in FIG. 15 (B), the concave portions 4 formed by the first intermediate surfaces 2b, 2b and the first inner end surfaces 2c, 2c of the both thick workpieces 1, 1 are the same as the concave portions 4. After the connection plate 5 having the cross-sectional shape is inserted, the butting portions 6, 6 between the connection plate 5 and the first inner end surfaces 2c, 2c of the thick workpieces 1, 1 are friction stir welded and joined together. W2 and W2 are formed. In addition, a connection having the same cross-sectional shape as the recess 4 ′ is connected to a recess 4 ′ formed by the second intermediate surfaces 2 b ′, 2 b ′ and the second inner end surfaces 2 c ′, 2 c ′ of the thick workpieces 1, 1. After loading the plate 5 ', the butting portions 6', 6 'between the connecting plate 5' and the second inner end surfaces 2c ', 2c' of the thick workpieces 1, 1 are friction stir welded. The joining lines W2 and W2 are formed.
Finally, as shown in FIG. 15C, the boundary surface 7 between the bottom surface of the connection plate 5 and the bottom surface of the concave portion 4 (first intermediate surfaces 2b, 2b) is friction-stirred to form the stirrer W3, and the connection is established. An agitating portion W3 is formed by friction-stirring the boundary surface 7 'between the bottom surface (the upper surface in the figure) of the plate 5' and the bottom surface (the second intermediate surfaces 2b ', 2b') of the concave portion 4.
[0036]
As described above, the present invention is also applicable to the case where the steps are formed on both the upper and lower sides along the joining end of each thick workpiece. The order of FIGS. 15B and 15C can be changed as appropriate.
[0037]
<Tenth embodiment>
FIG. 16 is a cross-sectional view illustrating each step of the tenth embodiment of the bonding method according to the present invention.
As shown in FIG. 16A, the thick materials 1 and 1 have a thickness of 10 to 15 mm, and a step 2 is formed along the joining end. The step portion 2 is formed by an outer end surface 2a having a large height (5 to 10 mm), an intermediate surface 2b, and an inner end surface 2c having a small height (5 mm or less). Then, the outer end surfaces 2a, 2a of the pair of thick workpieces 1, 1 are butted against each other to form a butt portion 3, and a tool for friction stir welding is inserted into the butt portion 3 from above and below. By performing friction stir welding, welding lines W1 and W1 are formed.
Next, as shown in FIG. 16 (B), a connection having the same cross-sectional shape as the recess 4 is formed in the recess 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the both thick workpieces 1, 1. After the plate 5 is inserted, the butting portions 6, 6 between the connection plate 5 and the inner end surfaces 2c, 2c of the thick workpieces 1, 1 are friction stir welded to form welding lines W2, W2. .
Finally, as shown in FIG. 16C, a boundary surface 7 between the bottom surface of the connection plate 5 and the bottom surface of the recess 4 (intermediate surfaces 2b, 2b) is friction-stirred to form a stirring portion W3.
[0038]
As described above, the present invention can cope with the case where the height of the outer end surface of the step formed along the joining end of each thick joining member is large. The order of FIGS. 16B and 16C can be changed as appropriate.
[0039]
<Eleventh embodiment>
FIG. 17 is a cross-sectional view illustrating each step of the eleventh embodiment of the bonding method according to the present invention. In the present embodiment, steps 2 and 2 ′ are formed on both upper and lower surfaces along the joining ends of the thick materials 1 and 1, respectively.
As shown in FIG. 17 (A), the thick material to be joined 1, 1 has a thickness of 15 to 20 mm, and an upper step 2 and a lower step 2 ′ are formed along the joining ends, respectively. The upper step 2 is formed of an outer end surface 2a, a first intermediate surface 2b, and a first inner end surface 2c, and the lower step 2 'is formed of an outer end surface 2a, a second intermediate surface 2b', and a second inner end surface 2c '. And formed. The height of the outer end face 2a is 5 to 10 mm. Then, the outer end surfaces 2a, 2a of the pair of thick workpieces 1, 1 are butted against each other to form a butt portion 3, and a tool for friction stir welding is inserted into the butt portion 3 from above and below. By performing friction stir welding, welding lines W1 and W1 are formed.
Next, as shown in FIG. 17 (B), the concave portions 4 formed by the first intermediate surfaces 2b, 2b and the first inner end surfaces 2c, 2c of the both thick workpieces 1, 1 are identical to the concave portions 4. After the connection plate 5 having the cross-sectional shape is inserted, the butting portions 6, 6 between the connection plate 5 and the first inner end surfaces 2c, 2c of the thick workpieces 1, 1 are friction stir welded and joined together. W2 and W2 are formed. In addition, a connection having the same cross-sectional shape as the recess 4 ′ is connected to a recess 4 ′ formed by the second intermediate surfaces 2 b ′, 2 b ′ and the second inner end surfaces 2 c ′, 2 c ′ of the thick workpieces 1, 1. After loading the plate 5 ', the butting portions 6', 6 'between the connecting plate 5' and the second inner end surfaces 2c ', 2c' of the thick workpieces 1, 1 are friction stir welded. The joining lines W2 and W2 are formed.
Finally, as shown in FIG. 17C, the boundary surface 7 between the bottom surface of the connection plate 5 and the bottom surface of the concave portion 4 (the first intermediate surfaces 2b, 2b) is friction-stirred to form the stirrer W3, and the connection is established. A stirrer W3 is formed by friction-stirring the boundary surface 7 'between the bottom surface (the upper surface in the figure) of the plate 5' and the bottom surface (the second intermediate surfaces 2b ', 2b') of the concave portion 4.
[0040]
As described above, the present invention can cope with the case where the step portions are formed on both the upper and lower sides along the joining end of each thick material to be joined, and the height of the outer end surface is large. The order of FIGS. 17B and 17C can be changed as appropriate.
[0041]
<Twelfth embodiment>
FIG. 18 is a sectional view showing each step of the twelfth embodiment of the joining method according to the present invention. This embodiment is basically the same as the first to fifth embodiments, except that each thick joined material is a curved plate material.
That is, as shown in FIG. 18A, a pair of thick workpieces 1 and 1 in which a step 2 including an outer end face 2a, an intermediate face 2b, and an inner end face 2c is formed along each joint end. Butt portions 3 are formed by butting the outer end surfaces 2a, 2a of each other, and the butt portions 3 are friction stir welded to form a joining line W1. The intermediate surface 2b is a curved surface.
Next, as shown in FIG. 18 (B), a connection having the same cross-sectional shape as the recess 4 is formed in the recess 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the thick workpieces 1, 1. After the plate 5 is inserted, the butting portions 6, 6 between the connection plate 5 and the inner end surfaces 2c, 2c of the thick workpieces 1, 1 are friction stir welded to form welding lines W2, W2. .
Finally, as shown in FIG. 18C, the boundary surface 7 between the bottom surface (intermediate surfaces 2b, 2b) of the concave portion 4 and the bottom surface of the connection plate 5 is integrated by friction stirring, and the stirring section including the boundary surface 7 Form W3.
[0042]
As described above, the present invention is also applicable to the case where each of the thick workpieces has a curved plate shape. The order of FIGS. 18A to 18C can be changed as appropriate.
[0043]
<About the tool>
The tool 20 for friction stirring used in each of the above embodiments can be appropriately changed. For example, in a friction stir tool 20 ′ shown in FIG. 19, a cylindrical stirring pin 23 hangs (eccentrically) from a position shifted from the center of the surface pressing portion 22 which is the bottom surface of the rotating cylindrical body 21. As described above, when the stirring pin 23 is eccentric with respect to the rotating cylinder 21, when the rotating cylinder 21 is rotated around its axis, the stirring pin 23 rotates and revolves around the axis of the rotating cylinder 21. Therefore, the stirring effect of the boundary surface 7 increases. Since a small screw-shaped friction stirrer blade 25 is formed on the peripheral surface of the stirring pin 23, the stirring pin 23 can be fixed to the rotating cylinder 22 by using the friction stirrer blade 25. The length of the protrusion can also be easily adjusted.
[0044]
Furthermore, the tools shown in FIGS. 20A to 20E can be used. In the tool 20A of FIG. 20 (A), the polygonal column-shaped stirring pin 23 hangs (eccentrically) from a position shifted from the center of the surface pressing portion 22 which is the bottom surface of the rotating cylindrical body 21, and the surface pressing portion 22 A ridge 24 projecting spirally from the periphery of the stirrer pin 23 toward the base end of the stirring pin 23 is formed. In each of the tools 20B to 20E shown in FIGS. 20B to 20E, the substantially cylindrical stirring pin 23 droops (eccentrically) from a position shifted from the center of the surface pressing portion 22 which is the bottom surface of the rotating cylindrical body 21. Further, the tool 20B has a cross-shaped ridge 26 formed on the bottom surface of the stirring pin 23, and the tool 20C has a large number of small rectangular parallelepiped projections 27, 27,. The tool 20D has a ring-shaped projection 28, 28,... Formed concentrically on the bottom surface of the stirring pin 23, and the tool 20E has a plurality of recesses near the bottom surface of the peripheral surface of the stirring pin 23. Grooves 29, 29,... Are formed. All of these tools increase the stirring effect of the boundary surface 7.
[0045]
In each of the above embodiments, the friction stir welding tool 10 and the friction stir tool 20 are provided separately. However, both the friction stir welding and the friction stirring may be performed with the same tool. .
[0046]
【The invention's effect】
As described above, according to the present invention, a joint formed by friction stir welding the gap between the bottom surface of the connection plate and the bottom surface of the concave portion, or the butted portion between the connection plate and the inner end surface of each thick workpiece. It is possible to obtain a joining structure of a thick material to be joined having high airtightness without leaving a tunnel-like cavity defect inside the wire.
[Brief description of the drawings]
FIGS. 1A to 1D are cross-sectional views illustrating respective steps of a first embodiment of a bonding method according to the present invention, FIG. 1C is a cc cross-sectional view of FIG. () Is a dd sectional view of (D).
FIGS. 2A to 2E are cross-sectional views illustrating respective steps of a first embodiment of a bonding method according to the present invention.
FIG. 3 is a perspective view illustrating one step of a first embodiment of a bonding method according to the present invention.
4A is a sectional view taken along a line aa in FIG. 3, and FIG. 4B is a plan view in FIG.
5A is a side view of the friction stir tool, FIG. 5B is a bottom view of FIG. 5A, and FIG. 5C is a cross-sectional view of FIG.
FIGS. 6A and 6B are plan views each showing another example of the movement locus of the friction stir tool.
FIGS. 7A and 7B are cross-sectional views each showing a state after the movement of the friction stir tool is completed.
FIGS. 8A to 8C are cross-sectional views illustrating respective steps of a second embodiment of the bonding method according to the present invention.
FIGS. 9A to 9C are cross-sectional views illustrating respective steps of a third embodiment of the bonding method according to the present invention.
FIGS. 10A to 10C are cross-sectional views illustrating respective steps of a fourth embodiment of the bonding method according to the present invention.
FIGS. 11A to 11D are cross-sectional views illustrating respective steps of a fifth embodiment of the bonding method according to the present invention.
FIGS. 12A to 12C are cross-sectional views illustrating respective steps of a sixth embodiment of the bonding method according to the present invention.
FIGS. 13A to 13C are cross-sectional views illustrating respective steps of a seventh embodiment of the bonding method according to the present invention.
14A to 14C are cross-sectional views illustrating respective steps of an eighth embodiment of the bonding method according to the present invention.
FIGS. 15A to 15C are cross-sectional views illustrating respective steps of a ninth embodiment of a bonding method according to the present invention.
FIGS. 16A to 16C are cross-sectional views illustrating respective steps of a tenth embodiment of the bonding method according to the present invention.
17A to 17C are cross-sectional views illustrating respective steps of an eleventh embodiment of the bonding method according to the present invention.
FIGS. 18A to 18C are cross-sectional views illustrating respective steps of a twelfth embodiment of a bonding method according to the present invention.
FIG. 19A is a perspective view showing another example of a friction stir tool, and FIG. 19B is a sectional view of the same.
FIGS. 20A to 20E are perspective views each showing another example of a friction stir tool.
FIGS. 21A to 21D are cross-sectional views illustrating each step of a conventional bonding method.
FIG. 22 is a partially enlarged perspective view of FIG. 20 (D).
[Explanation of symbols]
1 ... thick material to be joined
2 ... step
2a ... Outside end face
2b ... middle plane
2c… inside end face
2d ... wide bottom groove
3 ... Butt
4 ... recess
5 ... connecting plate
5a: First horizontal plane
5b… Second horizontal plane
5c… slope
5d… wide bottom ridge
6 ... Butt
7 ... Boundary surface
8 ... gap
10… Tools (for friction stir welding)
11 ... rotating cylinder
12… surface holding part
13 ... Stirring pin
20… Tools (for friction stirring)
21… rotating cylinder
22… surface holding part
23… stirring pin
24… ridge
25… Friction stirrer
26… ridge
27 ... projection
28 ... projection
29… groove
W1, W2 ... joining line
W3: Stirrer

Claims

A first step of abutting the outer end faces of a pair of thick workpieces having a stepped portion including an outer end face, an intermediate face, and an inner end face along each joining end, and friction stir welding the butted portions; Process and
A second step of loading a connection plate having the same or similar cross-sectional shape as the concave portion into the concave portion formed between the intermediate surface and the inner end surface of the both thick workpieces,
A third step of friction stir welding the butting portions of the connection plate and the inner end surfaces of the thick workpieces, respectively, and friction stirs a boundary surface between the connection plate and the bottom surface of the concave portion,
A method for joining thick material to be joined, characterized by comprising:

In the third step, after the friction stir welding of the butted portion between the connection plate and the inner end surface of each of the thick workpieces, friction stir the boundary surface between the connection plate and the bottom surface of the concave portion,
The method for joining a thick material to be joined according to claim 1, wherein:

Abutting the outer end surfaces of a pair of thick materials to be joined having a stepped portion including an outer end surface, an intermediate surface, and an inner end surface along each joint end, and intermediate the two thick materials to be joined. A first step of loading a connection plate having the same or similar cross-sectional shape as the concave portion into the concave portion formed by the surface and the inner end surface,
Abutting portions formed by abutting outer end surfaces of the pair of thick workpieces, and abutting portions of the connection plate and the inner end surfaces of the thick workpieces, respectively, are subjected to friction stir welding, respectively, A second step of friction-stirring a boundary surface between the connection plate and the bottom surface of the concave portion,
A method for joining thick material to be joined, characterized by comprising:

In the second step, friction agitation is performed on a butt portion formed by abutting outer end surfaces of the pair of thick workpieces and a butt portion between the connection plate and the inner end surface of each thick workpiece. After performing the joining, frictional stirring is performed on a boundary surface between the connection plate and the bottom surface of the concave portion.
The method for joining a thick material to be joined according to claim 3, wherein:

The friction stir of a boundary surface between the connection plate and the bottom surface of the concave portion is applied across a butt portion between the connection plate and an inner end surface of each of the thick workpieces.
The method for joining a thick material to be joined according to any one of claims 1 to 4, characterized in that:

When friction stir the interface between the connection plate and the bottom surface of the concave portion, move the friction stir tool from the center of the connection plate toward the peripheral edge,
The method for joining a thick material to be joined according to any one of claims 1 to 5, characterized in that:

A step portion including an outer end surface, an intermediate surface, and an inner end surface is formed along each joint end, and a pair of thick workpieces in which the outer end surfaces are butted against each other,
A connection plate having the same or similar cross-sectional shape as the concave portion, which is inserted into the concave portion formed by the intermediate surface and the inner end surface of the both thick workpieces,
With
A butt portion formed by abutting the outer surfaces of the thick workpieces, and a butt portion of the connection plate and an inner end surface of each of the thick workpieces are friction stir welded, respectively, A boundary surface between the connection plate and the bottom surface of the concave portion is friction-stirred,
A joining structure for a thick material to be joined.

The friction stir of a boundary surface between the connection plate and the bottom surface of the concave portion is performed across a butt portion between the connection plate and an inner end surface of each of the thick workpieces. Item 7. A bonding structure of a thick material to be bonded according to Item 7.