JP2004216421A

JP2004216421A - Friction stir welding method and equipment

Info

Publication number: JP2004216421A
Application number: JP2003006156A
Authority: JP
Inventors: Hideo Nakamura; 秀夫中村; Masaru Odajima; 賢小田島; Tsutomu Asaine; 勉朝稲; Masahiko Natsuume; 征彦夏梅
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2003-01-14
Filing date: 2003-01-14
Publication date: 2004-08-05
Anticipated expiration: 2023-01-14
Also published as: JP3762371B2

Abstract

<P>PROBLEM TO BE SOLVED: To satisfactorily join thin plate members to each other in particular and to maintain joining strength by securely eliminating unjoined parts. <P>SOLUTION: First and second abutting parts 48, 50 between a barrel member 42 and flange members 44, 46 are held on a first and a second backing holder 88, 92. In the first and second backing holders 88, 92, there is provided: a recessed part 97 that circumvents correspondingly to the inner circumferential face 48b of the first abutting part 48 between the barrel member 42 and the flange member 44; and also an opening part 99 that circumvents in communication with the bottom of the recessed part 97. In the recessed part 97, a first cushion member 98 is attached. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、第１プレート部材の端部と第２プレート部材の端部とを突き合わせた突き合わせ部の一方の面に、回転するプローブを押し付けながら、前記プローブを前記突き合わせ部に沿って相対的に移動させることにより、前記突き合わせ部を接合する摩擦撹拌接合方法および装置に関する。
【０００２】
【従来の技術】
一般的に、ワーク（物体）に回転するプローブを挿入する際に発生する摩擦熱を利用して、２つのワークを固相接合する摩擦撹拌溶接（ＦｒｉｃｔｉｏｎＳｔｉｒＷｅｌｄｉｎｇ：以下、ＦＳＷともいう）が知られている。上記の接合によると、ワークの接合部分は、母材に対して８０％程度の強度を維持することができ、結晶の粗大化も防止することが可能になる。
【０００３】
例えば、ワークとしてアルミニウム材を用い、従来のスポット溶接や電子ビームによる溶接を行うと、このアルミニウム材に過剰な熱が付与されてしまう。このため、材料の劣化や粗大化による強度の低下が惹起されるおそれがある。
【０００４】
これに対して、ＦＳＷでは、アルミニウム材のように比較的融点の低い金属材料（アルミニウム材では、６００℃〜６６０℃程度）を用いても、５００℃程度で接合が行われるため、熱による劣化が防止される。従って、ＦＳＷは、アルミニウム材の他、マグネシウムやチタン、高分子等の他の材料にも適用することが可能である。
【０００５】
上記のＦＳＷをアルミニウム材に適用する例として、電車のような大型部材のアルミニウムフレームが挙げられる。この種の大型部材は、接合の強度を重視しており、アルミニウム材の厚さは、通常、５ｍｍ以上に設定されている。一方、ガスタービンエンジン部材のように、強度の向上とともに軽量化を図ることが望まれている部材では、厚さを大きくすることができない。このため、例えば、１．２ｍｍ程度の薄板状のアルミニウム材を用い、ガスタービンエンジンの外枠を構成している。
【０００６】
しかしながら、薄板状のアルミニウム材の両端部を突き合わせた突き合わせ部を、ＦＳＷで接合して比較的大径な円筒部材を形成する際、このアルミニウム材が薄肉であるために真円度を得ることができないという問題がある。
【０００７】
さらに、２つの円筒部材の端部同士を突き合わせた突き合わせ部を、ＦＳＷにより接合する際、各端部の円周長さが同一寸法にならないおそれがある。従って、この状態で、円筒部材をＦＳＷにより接合すると、接合部の最終部位で位相差が発生し、例えば、波形に変形する、所謂、皺が惹起されるという問題がある。
【０００８】
しかも、特に薄板状のアルミニウム材の突き合わせ部は、ＦＳＷにより接合する際に未接合部分が発生し易い。具体的には、図１５に示すように、アルミニウム材Ｗ１、Ｗ２が突き合わされた状態で、突き合わせ部Ｔに回転しているプローブＰが挿入されると、この突き合わせ部Ｔには、プローブ先端Ｐａが到達しないことによる摩擦撹拌不足が惹起し、未接合部分Ｕが発生し易い。
【０００９】
さらに、プローブＰは、プローブ先端Ｐａに近づくにつれて周速が遅くなり、このプローブ先端Ｐａ近傍では、周速の低下によって摩擦撹拌される領域Ｓが制限されてしまう。これにより、摩擦熱が不足して未接合部分Ｕが生じ、この未接合部分Ｕが破壊起点となって構造上の信頼性が低下するという問題がある。
【００１０】
この他、ＦＳＷによる接合時には、薄板状のアルミニウム材Ｗ１、Ｗ２に１ｔ〜２ｔ単位の押し付け力が付与される。このため、アルミニウム材Ｗ１、Ｗ２を確実に保持し得ないと、接合部にはＦＳＷによって凹凸が発生するという問題がある。
【００１１】
そこで、例えば、特許文献１の突き合わせ継手の製造方法では、図１６に示すように、アルミニウム製の接合部材１ａ、１ｂの端面が突き合わされて突き合わせ部２が設けられるとともに、この突き合わせ部２に対応してアルミニウム製の裏当て部材３が配置される。この裏当て部材３の表面には、断面円弧状の凹部３ａが形成されている。
【００１２】
このような構成において、回転子４およびプローブ５を回転させて、このプローブ５を接合部材１ａ、１ｂの突き合わせ部２に挿入する。このため、接合部材１ａ、１ｂの突き合わせ部２は、裏面側が裏当て部材３の凹部３ａに沿って突出変形する。さらに、プローブ５を突き合わせ部２に挿入した状態で、前記突き合わせ部２に沿って移動させることにより、前記突き合わせ部２の全長にわたって摩擦撹拌接合が行われる。次いで、裏当て部材３の凹部３ａに突出変形した変形部６は、フライス盤等により切削されて平坦面が得られる。
【００１３】
【特許文献１】
特開平１０−２２５７８０号公報（段落［００３２］〜［００３６］、図３）
【００１４】
【発明が解決しようとする課題】
しかしながら、上記の特許文献１では、突き合わせ部２の裏面側を裏当て部材３の凹部３ａに突出変形させるために、プローブ５を前記突き合わせ部２の裏面まで挿入する必要がある。このため、特に、薄肉状の接合部材１ａ、１ｂが用いられる際には、接合部材１ａ、１ｂに破損が発生するおそれがある。
【００１５】
しかも、接合処理が終了した後、突き合わせ部２の裏面から裏当て部材３を剥離しなければならない。従って、薄肉状の接合部材１ａ、１ｂでは、裏当て部材３の剥離処理により残留歪みが発生するという問題が指摘されている。
【００１６】
一方、裏当て部材３は、剥離により破損するおそれがあり、これによって繰り返し利用することができず、経済的ではないという問題がある。
【００１７】
本発明はこの種の問題を解決するものであり、特に薄肉なプレート部材同士を良好に接合するとともに、未接合部分を確実に除去して接合強度を維持することが可能な摩擦撹拌接合方法および装置を提供することを目的とする。
【００１８】
【課題を解決するための手段】
本発明の請求項１に係る摩擦撹拌接合方法および請求項８に係る摩擦撹拌接合装置では、突き合わせ部の他方の面を保持する裏当て治具に、前記突き合わせ部に対応して形成された開口部を覆って緩衝部材が取り付けられる。次いで、第１および第２プレート部材が裏当て治具に保持された状態で、プローブを突き合わせ部の一方の面から挿入して前記緩衝部材および前記突き合わせ部の一部を開口部側に突出変形させながら、前記突き合わせ部に沿って摩擦撹拌接合が行われる。そして、摩擦撹拌接合が行われた後、突き合わせ部から開口部側に突出した部分が除去される。
【００１９】
このため、第１および第２プレート部材は、裏当て治具に張り付くことがなく、前記裏当て治具は、前記第１および第２プレート部材から剥離されることによる破損のおそれがない。これによって、裏当て治具は、繰り返し利用することができ、経済的である。さらに、第１および第２プレート部材は、緩衝部材に接合されることがなく、前記緩衝部材の離脱処理が容易に遂行されるとともに、残留歪みが発生することを有効に阻止することが可能になる。
【００２０】
しかも、未接合部分が発生し易い突き合わせ部の他方の面は、裏当て治具の開口部側に突出変形するとともに、摩擦撹拌接合が終了した後に前記突き合わせ部から除去される。従って、第１および第２プレート部材は、未接合部分を確実に除去することができ、接合部の強度が有効に増大して信頼性の向上を図ることが可能になる。
【００２１】
また、本発明の請求項２に係る摩擦撹拌接合方法では、摩擦撹拌接合が行われた後、突き合わせ部の他方の面に緩衝部材が圧着した状態で、前記突き合わせ部から裏当て治具のみが離脱される。次に、突き合わせ部の他方の面から緩衝部材が離脱される。このため、第１および第２プレート部材には、裏当て治具および緩衝部材が離脱される際に残留歪みが発生することがない。
【００２２】
さらに、本発明の請求項３に係る摩擦撹拌接合方法および請求項９に係る摩擦撹拌接合装置では、裏当て治具と突き合わせ部の他方の面とを密着状態にすることにより、前記第１および第２プレート部材の端部同士を同一の長さに規制する。従って、特に薄肉でかつ比較的大径な突き合わせ部であっても、プローブの挿入によって変形や皺等による位相差が発生することがなく、前記突き合わせ部の真円度を良好に維持することができ、寸法精度が向上する。しかも、突き合わせ部のずれを阻止して正確な位置出しが可能になり、摩擦撹拌接合処理が効率的に遂行される。
【００２３】
さらにまた、本発明の請求項４に係る摩擦撹拌接合方法および請求項１０に係る摩擦撹拌接合装置では、裏当て治具は、真円形状の外周面を有しており、この外周面に密着する第１および第２プレート部材の端部同士を同一の円周長さに規制する。これにより、簡単かつ経済的な構成および工程で、第１および第２プレート部材は、真円度を確実に維持して突き合わせ部の全周が良好に接合される。
【００２４】
その際、裏当て治具は、複数に分割されて径方向に進退自在な分割治具を備えるとともに、緩衝部材は、それぞれの分割治具に形成された各凹状部に一体的に嵌合自在なリング状に構成される（本発明の請求項４に係る摩擦撹拌接合方法および請求項１１に係る摩擦撹拌接合装置）。このため、摩擦撹拌接合後に、裏当て治具を突き合わせ部から容易かつ迅速に離脱させることができる。
【００２５】
また、本発明の請求項５に係る摩擦撹拌接合方法では、第１および第２プレート部材を裏当て治具に対し相対的に膨張させた状態で、前記裏当て治具に前記第１および第２プレート部材が配置される。例えば、第１および第２プレート部材が加熱されると、この第１および第２プレート部材が熱膨張して内周径が拡大する。従って、第１および第２プレート部材は、裏当て治具に容易に外装されるとともに、冷却されることにより収縮して前記裏当て治具の外周面に確実に密着する。
【００２６】
さらに、本発明の請求項６に係る摩擦撹拌接合方法および請求項１２に係る摩擦撹拌接合装置では、第１および第２プレート部材は、プローブの挿入方向と略直交する方向から加圧力が付与された状態で、突き合わせ部に沿って摩擦撹拌接合される。これにより、第１および第２プレート部材の端部同士を確実に圧着することができ、突き合わせ部を高品質に接合することが可能になる。
【００２７】
さらにまた、本発明の請求項７に係る摩擦撹拌接合方法および請求項１３に係る摩擦撹拌接合装置では、第１および第２プレート部材は、厚さが２ｍｍ以下に設定されている。このため、薄肉なプレート部材であっても、摩擦撹拌接合が良好に遂行されるとともに、前記薄肉なプレート部材に残留歪みが発生することを有効に阻止することができる。
【００２８】
【発明の実施の形態】
図１は、本発明の第１の実施形態に係る摩擦撹拌接合方法が実施されるファンダクト１０を組み込む航空機用ガスタービンエンジン１２の概略構成説明図である。
【００２９】
ガスタービンエンジン１２はファン１４を備え、このファン１４は、高速で回転して外部から空気を吸引し、この空気を圧縮して後方に圧送する。ファン１４の近傍には、コアダクト１６とファンダクト１０とによってファンバイパス通路１８が形成され、このファンバイパス通路１８を通って後方に噴射される空気を介し、図示しない機体に推力を生じさせる。
【００３０】
ファン１４は、低圧圧縮機２０を構成しており、この低圧圧縮機２０で圧縮された空気は、後段の高圧圧縮機２２に送られる。この高圧圧縮機２２で圧縮された空気は、さらに後段の燃焼室２４に送られる。この燃焼室２４は燃料ノズル２６を備え、この燃料ノズル２６から前記燃焼室２４に燃料が圧送される。燃焼室２４では、高圧圧縮機２２から圧送された圧縮空気と、燃料ノズル２６から噴霧された燃料とを混合した混合気が、エンジン始動時に点火されて燃焼する。
【００３１】
混合気が燃焼することによって高温高圧ガスが発生し、この高温高圧ガスは、高圧タービン２８に送られてこの高圧タービン２８を高速回転させる。この高圧タービン２８は、ファン１４のロータ１４ａを回転させる一方、高温高圧ガスは、前記高圧タービン２８を回転駆動した後、低圧タービン３０に送られる。低圧タービン３０は、低圧圧縮機２０のロータ１４ａおよびファン１４を回転させる。
【００３２】
ガスタービンエンジン１２の外部下面には、スタータおよび発電機を組み込むスタータジェネレータ３２が、アクセサリギアボックス３４を介して取り付けられる。
【００３３】
図２は、ファンダクト１０を構成するダクト構造体４０の説明図である。このダクト構造体４０は、薄板状、例えば、厚さが２ｍｍ以下のアルミニウム材を略円筒形状に成形した胴部材（第１プレート部材）４２と、薄板状のアルミニウム材を略円筒形状に成形したフランジ部材（第２プレート部材）４４、４６とを備える。胴部材４２の端部４２ａ、４２ｂと、フランジ部材４４、４６の端部４４ａ、４６ａとを突き合わせた第１および第２突き合わせ部４８、５０は、その外周面（一方の面）４８ａ、５０ａに摩擦撹拌接合が行われ、前記胴部材４２と前記フランジ部材４４、４６とが接合される。
【００３４】
図３は、上記のダクト構造体４０を摩擦撹拌接合する本発明の第１の実施形態に係る摩擦撹拌接合装置６０の一部分解斜視図であり、図４は、前記摩擦撹拌接合装置６０の断面説明図である。
【００３５】
この摩擦撹拌接合装置６０は、回転テーブル６２に固定されて回転されるとともに、予め仮接合された胴部材４２とフランジ部材４４、４６とを一体的に保持する台部材６４を備える。台部材６４の上部には、略円盤状の支持ベース６６が固着され、この支持ベース６６の中央部には、鉛直方向（矢印Ａ方向）に延在して支柱６８が立設される。支柱６８の先端には、加圧機構７０を構成するねじ部７２が形成される。
【００３６】
加圧機構７０は加圧板７４を備え、この加圧板７４は、略円盤状を有するとともに、中央部に支柱６８を挿入する孔部７６が形成される。加圧板７４は、支持ベース６６上に配置される胴部材４２およびフランジ部材４４、４６を後述するプローブ１４４（図５参照）の挿入方向（矢印Ｂ方向）と略直交する矢印Ａ方向から加圧力を付与する機能を有する。
【００３７】
加圧板７４の中央部分には、押圧ブロック７７が係合するとともに、ねじ部７２に螺合するナット部材７８が前記押圧ブロック７７を介して加圧板７４を矢印Ａ方向に加圧する。ねじ部７２の先端には、吊り下げ用ボルト７９が螺着される。加圧板７４には、等角度間隔離間して複数の開口部８０と、前記開口部８０よりも小径な複数の開口部８２とが形成される。
【００３８】
支持ベース６６には、支柱６８を中心に周回するリング部８６が矢印Ａ方向に膨出して形成される。リング部８６の外周には、第１裏当て治具８８が着脱自在に設けられるとともに、前記リング部８６に固定されるロッド９０を介して第２裏当て治具９２が取り付けられる。
【００３９】
第１裏当て治具８８は、例えば、鉄系材料で形成された複数、例えば、４つの分割治具９４ａ〜９４ｄを備えており、全体として略リング状を有する。分割治具９４ａ〜９４ｄは、アクチュエータ、例えば、シリンダ９６ａ〜９６ｄに連結されて半径方向に個別に進退可能に構成される。
【００４０】
第１裏当て治具８８の外周面８８ａは、真円形状に設定される。この第１裏当て治具８８の外周面８８ａには、図５に示すように、胴部材４２とフランジ部材４４との第１突き合わせ部４８の内周面（他方の面）４８ｂに対応して周回する凹状部９７が設けられるとともに、前記凹状部９７の底部に連通して周回する開口部９９が形成される。
【００４１】
凹状部９７には、第１突き合わせ部４８に摩擦撹拌接合が行われた後、前記第１突き合わせ部４８の内周面４８ｂから離脱される第１緩衝部材９８が取り付けられる。この第１緩衝部材９８は、例えば、鉄系材料あるいはアルミニウム製のリング材で構成されるとともに、厚さが凹状部９７の深さと同一寸法、例えば、略１ｍｍ程度の厚さに設定される。開口部９９は、第１裏当て治具８８の外周面８８ａを周回しかつ凹状部９７よりも幅狭な凹状溝に構成され、第１突き合わせ部４８の内周面４８ｂにおいて、摩擦撹拌接合後に未接合部分となり易い領域を収容し得る寸法に限定されている。例えば、未接合部分が２０μｍ〜３０μｍである際に、開口部９９の深さが５０μｍ程度に設定される。
【００４２】
図４に示すように、リング部８６の上面には、所定の角度間隔ずつ離間してねじ穴１００が形成され、前記ねじ穴１００には、各ロッド９０が一方の端部に設けられるねじ部１０２が螺合する。ロッド９０の他方の端部には、ねじ穴１０４が形成され、第２裏当て治具９２を構成する取り付け板１０６からボルト１０８がねじ込まれることにより、前記取り付け板１０６がロッド９０に固定される。
【００４３】
図３および図４に示すように、第２裏当て治具９２は、例えば、鉄系材料で形成された複数の分割治具、例えば、４つの分割治具１１０ａ〜１１０ｄを備えており、全体として略リング状を有する。分割治具１１０ａ〜１１０ｄは、アクチュエータ、例えば、シリンダ１１２ａ〜１１２ｄに連結されて取り付け板１０６上を半径方向に個別に進退可能に構成される。
【００４４】
第２裏当て治具９２の外周面９２ａは、全体として真円形状に構成される。この第２裏当て治具９２の外周面９２ａには、図６に示すように、胴部材４２とフランジ部材４４との第２突き合わせ部５０の内周面（他方の面）５０ｂに対応して周回する凹状部１１４が設けられるとともに、前記凹状部１１４の底部に連通して周回する開口部１１５が形成される。
【００４５】
凹状部１１４には、第２突き合わせ部５０に摩擦撹拌接合が行われた後、前記第２突き合わせ部５０の内周面５０ｂから離脱される第２緩衝部材１１６が取り付けられる。この第２緩衝部材１１６は、例えば、鉄系材料あるいはアルミニウム製のリング材で構成されるとともに、その厚さが凹状部１１４の深さと同一寸法、例えば、略１ｍｍ程度の厚さに設定される。開口部１１５は、第２裏当て治具９２の外周面９２ａを周回しかつ凹状部１１４よりも幅狭な凹状溝に構成され、第２突き合わせ部５０の内周面５０ｂにおいて、摩擦撹拌接合後に未接合部分となり易い領域を収容し得る寸法に設定されている。
【００４６】
図３および図４に示すように、第１および第２裏当て治具８８、９２の外周面８８ａ、９２ａは、ダクト構造体４０のスプリングバックを考慮して、前記ダクト構造体４０を最終的に設計寸法に維持する必要があり、前記第１および第２裏当て治具８８、９２が拡径した際の前記外周面８８ａ、９２ａの最大外径寸法は、加熱前の第１および第２突き合わせ部４８、５０の内径よりも大きい。
【００４７】
第１突き合わせ部４８の外周面４８ａには、前記第１突き合わせ部４８を保持する第１クランプ治具１１７が配置されるとともに、第２突き合わせ部５０の外周面５０ａには、前記第２突き合わせ部５０を保持する第２クランプ治具１１８が配置される。
【００４８】
図３に示すように、第１クランプ治具１１７は、角材をリング状に成形してベルト状に構成される。第１クランプ治具１１７の一方の端面には、ねじ穴１１９が形成されるとともに、他方の端面には、孔部１２０が形成される。ボルト１２２が孔部１２０を通ってねじ穴１１９にねじ込まれることにより、第１クランプ治具１１７は、径方向の寸法が縮小されて第１突き合わせ部４８の外周面４８ａを締め付ける。
【００４９】
図３および図４に示すように、支持ベース６６の外周縁部には、ボルト１２４を介して複数本のロッド１２６が固定される。各ロッド１２６は、矢印Ａ方向に延在しており、その端部にねじ込まれるボルト１２８を介して取り付け板１３０が設けられる。この取り付け板１３０は、略リング状に構成され、ボルト１３２を介して前記取り付け板１３０に第２クランプ治具１１８が固定される。第２クランプ治具１１８は、略リング状に構成され、第２突き合わせ部５０の外周面５０ａを締め付け保持する。
【００５０】
図５に示すように、第１突き合わせ部４８を接合する接合機１４０は、回転工具１４２を備える。この回転工具１４２の先端には、所定の長さだけ突出するプローブ１４４が設けられる。このプローブ１４４は、第１突き合わせ部４８に挿入されるプローブ先端部１１４ａの長さが、前記第１突き合わせ部４８の肉厚よりも短尺に設定される。なお、第２突き合わせ部５０は、上記の接合機１４０により接合してもよく（図６参照）、あるいは個別の接合機を用いて接合作業を行ってもよい。
【００５１】
このように構成される摩擦撹拌接合装置６０の動作について、第１の実施形態に係る摩擦撹拌接合方法との関連で、図７に示すフローチャートに沿って以下に説明する。
【００５２】
まず、円筒形状を有する胴部材４２およびフランジ部材４４、４６が作製される（ステップＳ１）。具体的には、図２に示すように、胴部材４２を構成する薄板状のアルミニウム材を略円筒形状に成形し、その両端部を突き合わせた突き合わせ部４２ｃに沿って摩擦撹拌接合（ＦＳＷ）が行われ、前記突き合わせ部４２ｃが接合される。このため、胴部材４２が得られる。
【００５３】
同様に、フランジ部材４４、４６を構成する薄板状のアルミニウム材が略円筒形状に成形された後、それぞれの突き合わせ部４４ｃ、４６ｃが摩擦撹拌接合により接合される。従って、フランジ部材４４、４６が得られる。
【００５４】
なお、上記の摩擦撹拌接合時には、図示しないプローブが、円筒形状の中心から所定距離だけオフセットして配置されており、接合面の切断を有効に阻止している。
【００５５】
次いで、胴部材４２の端部４２ａ、４２ｂにフランジ部材４４、４６の端部４４ａ、４６ａを突き合わせた状態で、第１および第２突き合わせ部４８、５０には、所定の個所にアルミニウムテープ（図示せず）が貼り付けられる。このため、胴部材４２の両側にフランジ部材４４、４６が仮接合される（ステップＳ２）。この仮接合された胴部材４２およびフランジ部材４４、４６は、図示しない加熱炉内に配置されて所定の温度に加熱される（ステップＳ３）。所定温度に加熱された胴部材４２およびフランジ部材４４、４６は、台部材６４にセットされる（ステップＳ４）。
【００５６】
具体的には、図３および図４に示すように、台部材６４を構成する支持ベース６６上には、リング部８６を周回して第１裏当て治具８８を構成する分割治具９４ａ〜９４ｄが半径内方向に配置されている。従って、第１裏当て治具８８は、外周面８８ａの直径が最小直径に維持されており、この外周面８８ａの凹状部９７に対応して第１緩衝部材９８が配置された状態で、シリンダ９６ａ〜９６ｄが駆動される。このため、分割治具９４ａ〜９４ｄは、半径外方向に移動して第１裏当て治具８８の外周面８８ａが拡径し、この外周面８８ａにより第１緩衝部材９８が押圧保持される。
【００５７】
一方、リング部８６に形成されたねじ穴１００には、ロッド９０のねじ部１０２が螺着される。ロッド９０上には、第２裏当て治具９２を構成する取り付け板１０６が配置され、前記ロッド９０のねじ穴１０４に前記取り付け板１０６の孔部を通ってボルト１０８が螺着される。これにより、各ロッド９０には、取り付け板１０６が固定されるとともに、分割治具１１０ａ〜１１０ｄが半径内方向に配置されている。
【００５８】
この状態で、第２裏当て治具９２の外周面９２ａに第２緩衝部材１１６が配置され、シリンダ１１２ａ〜１１２ｄが駆動されて分割治具１１０ａ〜１１０ｄが半径外方向に移動する。従って、外周面９２ａが拡径してこの外周面９２ａにより第２緩衝部材１１６が押圧保持される。
【００５９】
そこで、所定温度に加熱された胴部材４２およびフランジ部材４４、４６は、第１および第２裏当て治具８８、９２に外装される。この場合、胴部材４２およびフランジ部材４４、４６は、所定の温度に加熱されており、熱膨張によって内周径が拡大している。このため、胴部材４２およびフランジ部材４４、４６の第１および第２突き合わせ部４８、５０は、第１および第２裏当て治具８８、９２に配置された第１および第２緩衝部材９８、１１６に容易に外装される。
【００６０】
さらに、胴部材４２およびフランジ部材４４、４６は、冷却されることによって内周径が収縮し、第１および第２突き合わせ部４８、５０の内周面４８ｂ、５０ｂは、第１および第２裏当て治具８８、９２の外周面８８ａ、９２ａ、すなわち、第１および第２緩衝部材９８、１１６に密着した状態で確実に嵌合する（図５および図６参照）。第１および第２裏当て治具８８、９２の外周面８８ａ、９２ａの最大外径寸法が、加熱前の第１および第２突き合わせ部４８、５０の内周面４８ｂ、５０ｂの内径寸法よりも大きいからである。
【００６１】
ここで、第１および第２裏当て治具８８、９２の外周面８８ａ、９２ａは、真円形状を有しており、この外周面８８ａ、９２ａの凹状部９７、１１４に嵌合する第１および第２緩衝部材９８、１１６に密着する端部４２ａ、４４ａおよび端部４２ｂ、４６ａは、それぞれ同一の円周長さに規制されるとともに、真円形状に維持される。
【００６２】
次に、第２裏当て治具９２上に加圧板７４が配置され、押圧ブロック７７がねじ部７２に外装された後、ナット部材７８が前記ねじ部７２にねじ込まれる。これにより、押圧ブロック７７を介して加圧板７４が加圧され、胴部材４２およびフランジ部材４４、４６は、矢印Ａ方向に締め付け荷重が付与される。この結果、第１および第２突き合わせ部４８、５０は、隙間が生じない状態で押圧保持される（ステップＳ５）。そして、ステップＳ６に進み、第１および第２突き合わせ部４８、５０に貼り付けられているアルミニウムテープ（図示せず）が除去され、表面の洗浄が行われる。
【００６３】
さらに、ステップＳ７において、第１クランプ治具１１７が装着される。この第１クランプ治具１１７は、ベルト状に構成されており、胴部材４２の外周を端部４２ａ側に沿って周回している。そこで、孔部１２０にボルト１２２を挿入し、このボルト１２２をねじ穴１１９にねじ込むことにより、第１クランプ治具１１７の内周径が縮小する。従って、第１クランプ治具１１７は、胴部材４２の外周面を締め付け保持する。
【００６４】
次いで、台部材６４は、回転テーブル６２にねじ止めによって固定される（ステップＳ８）。この状態で、図８に示すように、接合機１４０を構成する回転工具１４２が高速で回転しながら、第１突き合わせ部４８に向かって（矢印Ｂ方向）移動する。このため、高速回転するプローブ１４４のプローブ先端１４４ａが第１突き合わせ部４８に挿入され、摩擦熱によって前記第１突き合わせ部４８が溶接される（図９参照）。
【００６５】
その際、第１突き合わせ部４８には、第１裏当て治具８８に設けられた開口部９９に向かって加圧力が付与される。従って、第１緩衝部材９８の裏面側および第１突き合わせ部４８の一部は、開口部９９内に突出変形する一方、高速回転するプローブ１４４は、回転テーブル６２の回転作用下に前記第１突き合わせ部４８に沿って相対的に移動し、該第１突き合わせ部４８の全周にわたり接合作業が遂行される（ステップＳ９）。
【００６６】
第１突き合わせ部４８の接合作業が終了すると、回転テーブル６２が停止されるとともに、接合機１４０がこの第１突き合わせ部４８から離間する。さらに、第１クランプ治具１１７が取り外される一方、第２クランプ治具１１８が取り付けられる（ステップＳ１０）。第１クランプ治具１１７は、ボルト１２２をねじ穴１１９から離脱させることにより、内周径が拡大して胴部材４２から取り外される。
【００６７】
一方、支持ベース６６の外周縁部には、ボルト１２４を介して複数のロッド１２６が取り付けられ、前記ロッド１２６の先端部には、ボルト１２８を介して取り付け板１３０が取り付けられる。この取り付け板１３０には、ボルト１３２を介して第２クランプ治具１１８が装着され、この第２クランプ治具１１８が胴部材４２の端部４２ｂ側の外周面を締め付け保持する。
【００６８】
この状態で、図１０に示すように、例えば、接合機１４０が第２突き合わせ部５０に対応して配置され、回転工具１４２と一体的にプローブ１４４が回転しながら、このプローブ１４４のプローブ先端１４４ａが前記第２突き合わせ部５０の外周面５０ａに挿入される。この第２突き合わせ部５０は、回転テーブル６２の回転作用下に接合機１４０に対して回転しており、前記第２突き合わせ部５０の全周にわたって摩擦撹拌接合が行われる（ステップＳ１１）。
【００６９】
上記のように、第１および第２突き合わせ部４８、５０が接合されて接合品であるダクト構造体４０が得られた後、このダクト構造体４０は、第１および第２裏当て治具８８、９２とともに、台部材６４から取り外される（ステップＳ１２）。具体的には、第１裏当て治具８８を構成する分割治具９４ａ〜９４ｄは、シリンダ９６ａ〜９６ｄの駆動によって半径内方向に移動し、外周面８８ａが第１緩衝部材９８から離間する（図１１参照）。一方、第２裏当て治具９２を構成する分割治具１１０ａ〜１１０ｄは、シリンダ１１２ａ〜１１２ｄの作用下に半径内方向に移動し、外周面９２ａが第２緩衝部材１１６から離間する。
【００７０】
そこで、吊り下げ用ボルト７９およびナット部材７８がねじ部７２から離脱されて押圧ブロック７７が取り外されるとともに、加圧板７４が支柱６８から取り外される。そして、ダクト構造体４０は、第１および第２緩衝部材９８、１１６を内周面に保持した状態で、支持ベース６６から取り出される。次に、図１２に示すように、第１突き合わせ部４８では、第１緩衝部材９８がダクト構造体４０の内周面から離脱される（ステップＳ１３）。ダクト構造体４０の内周面には、第１突き合わせ部４８に対応して開口部９９側に突出変形した突起部１５０が設けられており、この突起部１５０が切削加工等によって前記内周面から除去される（ステップＳ１４）。なお、第２突き合わせ部５０では、上記の第１突き合わせ部４８と同様の作業が行われる。
【００７１】
このように、第１の実施形態では、第１および第２裏当て治具８８、９２の外周面８８ａ、９２ａに、第１および第２突き合わせ部４８、５０に対応して凹状部９７、１１４が形成され、この凹状部９７、１１４に第１および第２緩衝部材９８、１１６が装着される。このため、第１および第２突き合わせ部４８、５０の内周面４８ｂ、５０ｂに第１および第２緩衝部材９８、１１６が密着した状態で、前記第１および第２突き合わせ部４８、５０の外周面４８ａ、５０ａに摩擦撹拌接合が行われる。
【００７２】
従って、第１および第２突き合わせ部４８、５０は、第１および第２裏当て治具８８、９２に張り付くことがなく、前記第１および第２裏当て治具８８、９２は、ダクト構造体４０から剥離されることによる破損のおそれがない。これによって、第１および第２裏当て治具８８、９２は、繰り返し利用することができ、経済的であるという効果が得られる。
【００７３】
しかも、図９に示すように、第１裏当て治具８８の外周面８８ａには、第１突き合わせ部４８の内周面４８ｂに対応して周回する凹状部９７が設けられるとともに、この凹状部９７の底部に連通して周回する開口部９９が形成されている。凹状部９７には、第１緩衝部材９８が取り付けられており、プローブ先端１４４ａが第１突き合わせ部４８の外周面４８ａから挿入されることにより、第１緩衝部材９８および前記第１突き合わせ部４８の内周面４８ｂの一部が前記開口部９９側に突出変形される。
【００７４】
このため、プローブ先端１４４ａが到達せず、かつ、前記プローブ先端１４４ａの周速の影響によって未接合部分が発生し易い内周面４８ｂ側には、開口部９９側に突出変形して突起部１５０が設けられる。そして、この突起部１５０は、摩擦撹拌接合後に切削加工等によって内周面４８ｂから除去される（図１２および図１３参照）。
【００７５】
従って、ダクト構造体４０は、未接合部分を確実に除去することができ、接合部の強度が有効に増大して信頼性の向上を図ることが可能になるという効果が得られる。
【００７６】
また、第１および第２突き合わせ部４８、５０は、第１および第２緩衝部材９８、１１６に接合されることがなく、前記第１および第２緩衝部材９８、１１６の離脱処理が容易に遂行される。さらに、ダクト構造体４０には、第１および第２緩衝部材９８、１１６の剥離による残留歪みが発生することがない。
【００７７】
特に、第１および第２裏当て治具８８、９２の外周面８８ａ、９２ａが真円形状に構成されており、第１および第２突き合わせ部４８、５０の内周面４８ｂ、５０ｂは、前記外周面８８ａ、９２ａに密着して真円形状が維持される。しかも、それぞれの端部４２ａ、４４ａの内周長さおよび端部４２ｂ、４６ａの円周長さが同一の長さに規制される。
【００７８】
このため、厚さが２ｍｍ以下の薄肉でかつ比較的大径な第１および第２突き合わせ部４８、５０であっても、変形や皺等による位相差が発生することがなく、前記第１および第２突き合わせ部４８、５０の真円度を良好に維持することができ、寸法精度が向上する。これにより、簡単かつ経済的な工程で、第１および第２突き合わせ部４８、５０の摩擦撹拌接合作業が効率的に遂行されるという効果が得られる。
【００７９】
さらに、第１および第２突き合わせ部４８、５０は、第１および第２緩衝部材９８、１１６を介して第１および第２裏当て治具８８、９２の外周面８８ａ、９２ａに密着状態で嵌合する。このため、第１および第２突き合わせ部４８、５０のずれを阻止して正確な位置出しが可能になり、摩擦撹拌接合処理が効率的に遂行される。
【００８０】
その際、第１および第２突き合わせ部４８、５０は、所定温度に加熱されることによって熱膨張により内周径を拡大させた状態で、第１および第２裏当て治具８８、９２に嵌合している。従って、第１および第２裏当て治具８８、９２の外周面８８ａ、９２ａに対し、第１および第２突き合わせ部４８、５０を容易かつ確実に密着させることができる。
【００８１】
さらにまた、胴部材４２とフランジ部材４４、４６とは、加圧機構７０を介してプローブ１４４の挿入方向（矢印Ｂ方向）と略直交する方向（矢印Ａ方向）から加圧力が付与される。これにより、第１および第２突き合わせ部４８、５０に隙間が発生することがなく、確実に圧着することができ、高品質な接合処理が遂行されるとともに、加圧機構７０の構成が容易に簡素化する。
【００８２】
なお、上記した第１の実施形態では、図示しないアルミニウムテープで仮接合された胴部材４２と、フランジ部材４４、４６とを、加熱炉内で所定温度に加熱することにより、内周径を拡径させて第１および第２裏当て治具８８、９２に装着しているが、これに限定されるものではない。例えば、第１および第２裏当て治具８８、９２を冷却して該第１および第２裏当て治具８８、９２の外径寸法を縮小させてもよい。
【００８３】
また、それぞれ４分割された分割治具９４ａ〜９４ｄ、１１０ａ〜１１０ｄを用いているが、分割数は種々選択可能である。さらに、シリンダ９６ａ〜９６ｄ、１１２ａ〜１１２ｄに代替して電磁ソレノイド等の駆動源を用いてもよい。さらにまた、分割治具９４ａ〜９４ｄ（および／または分割治具１１０ａ〜１１０ｄ）を単一の駆動源を介して一体的に進退させることもできる。
【００８４】
図１４は、本発明の第２の実施形態に係る摩擦撹拌接合装置１６０の一部斜視図である。なお、第１の実施形態に係る摩擦撹拌接合装置６０と同一の構成要素には同一の参照符号を付して、その詳細な説明は省略する。
【００８５】
摩擦撹拌接合装置１６０は、第１および第２裏当て治具１６２、１６４を備える。第１裏当て治具１６２は、例えば、鉄系材料で形成された複数の分割治具、例えば、４つの分割治具９４ａ〜９４ｄと、前記分割治具９４ａ〜９４ｄの内側に配置されて該分割治具９４ａ〜９４ｄを拡径させる第１リング部材１６６とを備える。第２裏当て治具１６４は、第１裏当て治具１６２と同様に、例えば、鉄系材料で形成された複数、例えば、４つの分割治具１１０ａ〜１１０ｄと、前記分割治具１１０ａ〜１１０ｄの内側に配置されて該分割治具１１０ａ〜１１０ｄを拡径させる第２リング部材１６８とを備える。
【００８６】
このように構成される摩擦撹拌接合装置１６０では、第１裏当て治具１６２を構成する分割治具９４ａ〜９４ｄの外周に第１緩衝部材９８が配置された状態で、この分割治具９４ａ〜９４ｄの内側に第１リング部材１６６が挿入される。これにより、分割治具９４ａ〜９４ｄが拡径して前記分割治具９４ａ〜９４ｄの外周に第１リング部材１６６が密着保持される。同様に、第２リング部材１６８が第２裏当て治具１６４を構成する分割治具１１０ａ〜１１０ｄの内側に挿入されることによって、前記分割治具１１０ａ〜１１０ｄの外周には、第２緩衝部材１１６が密着保持される。
【００８７】
従って、第２の実施形態では、第１の実施形態と同様の効果が得られるとともに、構成が一層簡素化するという利点がある。なお、第１および第２リング部材１６６、１６８に代替して楔部材等を使用してもよい。
【００８８】
【発明の効果】
本発明に係る摩擦撹拌接合方法および装置では、未接合部分が発生し易い突き合わせ部の他方の面は、裏当て治具の開口部側に突出変形するとともに、摩擦撹拌接合が終了した後に前記突き合わせ部から除去される。従って、第１および第２プレート部材は、未接合部分を確実に除去することができ、接合部の強度が有効に増大して信頼性の向上を図ることが可能になる。
【００８９】
さらに、裏当て治具は、第１および第２プレート部材から剥離されることによる破損のおそれがなく、前記裏当て治具を繰り返し利用することができ、経済的である。また、緩衝部材の離脱処理が容易に遂行されるとともに、特に薄肉な第１および第２プレート部材であっても、残留歪みが発生することを有効に阻止することが可能になる。
【図面の簡単な説明】
【図１】本発明の実施形態に係る摩擦撹拌接合方法が実施されるファンダクトを組み込む航空機用ガスタービンエンジンの概略構成説明図である。
【図２】前記ファンダクトを構成するダクト構造体の説明図である。
【図３】前記ダクト構造体を接合する本発明の第１の実施形態に係る摩擦撹拌接合装置の一部分解斜視図である。
【図４】前記摩擦撹拌接合装置の断面説明図である。
【図５】第１裏当て治具の拡大説明図である。
【図６】第２裏当て治具の拡大説明図である。
【図７】前記摩擦撹拌接合方法のフローチャートである。
【図８】第１突き合わせ部を接合する際の動作説明図である。
【図９】前記第１突き合わせ部を接合する際の断面説明図である。
【図１０】第２突き合わせ部を接合する際の動作説明図である。
【図１１】前記第１突き合わせ部から前記第１裏当て治具を分離する際の動作説明図である。
【図１２】前記第１突き合わせ部から第１緩衝部材を分離する際の動作説明図である。
【図１３】前記第１突き合わせ部から未接合部を除去する際の動作説明図である。
【図１４】本発明の第２の実施形態に係る摩擦撹拌接合装置の一部斜視図である。
【図１５】摩擦撹拌接合による未接合部の説明図である。
【図１６】特許文献１のアルミニウム部材の接合方法を示す説明図である。
【符号の説明】
１０…ファンダクト１２…ガスタービンエンジン
１４…ファン４０…ダクト構造体
４２…胴部材４４、４６…フランジ部
４４ａ、４６ａ…端部４８、５０…突き合わせ部
４８ａ、５０ａ、８８ａ、９２ａ…外周面４８ｂ、５０ｂ…内周面
６０、１６０…摩擦撹拌接合装置６２…回転テーブル
６４…台部材６６…支持ベース
６８…支柱７０…加圧機構
７２…ねじ部７４…加圧板
７７…押圧ブロック
８８、９２、１６２、１６４…裏当て治具９０…ロッド
９４ａ〜９４ｄ、１１０ａ〜１１０ｄ…分割治具
９６ａ〜９６ｄ、１１２ａ〜１１２ｄ…シリンダ
９７、１１４…凹状部９８、１１６…緩衝部材
９９、１１５…開口部１１７、１１８…クランプ治具
１３０…取り付け板１４０…接合機
１４４…プローブ１６６、１６８…リング部材[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, the probe is relatively moved along the butting portion while pressing the rotating probe against one surface of a butting portion where the end of the first plate member and the end of the second plate member are butted. The present invention relates to a friction stir welding method and apparatus for joining the butted portions by moving.
[0002]
[Prior art]
In general, friction stir welding (hereinafter, also referred to as FSW) for solid-phase joining two works by utilizing frictional heat generated when a rotating probe is inserted into a work (object) is known. Have been. According to the above-described joining, the joint portion of the work can maintain a strength of about 80% with respect to the base material, and the crystal can be prevented from becoming coarse.
[0003]
For example, when an aluminum material is used as a work and conventional spot welding or welding using an electron beam is performed, excessive heat is applied to the aluminum material. For this reason, there is a possibility that the strength may be reduced due to the deterioration or coarsening of the material.
[0004]
On the other hand, in the case of FSW, even if a metal material having a relatively low melting point such as an aluminum material (about 600 ° C. to 660 ° C. for an aluminum material) is used, bonding is performed at about 500 ° C. Is prevented. Therefore, the FSW can be applied to other materials such as magnesium, titanium, and a polymer in addition to the aluminum material.
[0005]
An example of applying the above FSW to an aluminum material is an aluminum frame of a large member such as a train. This type of large-sized member emphasizes the strength of bonding, and the thickness of the aluminum material is usually set to 5 mm or more. On the other hand, in a member such as a gas turbine engine member in which it is desired to reduce the weight while improving the strength, the thickness cannot be increased. For this reason, for example, an outer frame of a gas turbine engine is formed by using a thin aluminum material having a thickness of about 1.2 mm.
[0006]
However, when a butted portion obtained by butting both ends of a thin aluminum material is joined by FSW to form a relatively large-diameter cylindrical member, roundness may be obtained because the aluminum material is thin. There is a problem that can not be.
[0007]
Furthermore, when the butted portions where the ends of the two cylindrical members are butted to each other are joined by FSW, there is a possibility that the circumferential length of each end may not be the same. Therefore, when the cylindrical members are joined by the FSW in this state, there is a problem that a phase difference is generated at a final portion of the joined portion and, for example, a so-called wrinkle is caused to be deformed into a waveform.
[0008]
In addition, in particular, the butted portion of the thin aluminum material is likely to have an unjoined portion when joined by FSW. Specifically, as shown in FIG. 15, when the rotating probe P is inserted into the butting portion T in a state where the aluminum materials W1 and W2 are butted, the probe tip Pa is inserted into the butting portion T. Does not reach, frictional agitation is insufficient, and an unjoined portion U is likely to occur.
[0009]
Furthermore, the peripheral speed of the probe P becomes slower as it approaches the probe tip Pa, and in the vicinity of the probe tip Pa, the region S subjected to frictional stirring is limited due to a decrease in the peripheral speed. As a result, there is a problem that an unjoined portion U is generated due to a lack of frictional heat, and the unjoined portion U serves as a starting point of destruction, thereby lowering structural reliability.
[0010]
In addition, at the time of joining by the FSW, a pressing force of 1 t to 2 t units is applied to the thin aluminum materials W1 and W2. For this reason, if the aluminum materials W1 and W2 cannot be reliably held, there is a problem that unevenness occurs at the joint due to FSW.
[0011]
Therefore, for example, in the method of manufacturing a butt joint disclosed in Patent Document 1, as shown in FIG. 16, the end surfaces of the aluminum joining members 1a and 1b are butted together to provide a butt portion 2. Then, the aluminum backing member 3 is arranged. On the surface of the backing member 3, a concave portion 3a having an arc-shaped cross section is formed.
[0012]
In such a configuration, the rotor 4 and the probe 5 are rotated, and the probe 5 is inserted into the butting portion 2 of the joining members 1a and 1b. For this reason, the butting portion 2 of the joining members 1 a and 1 b is deformed so that the back surface side protrudes along the concave portion 3 a of the backing member 3. Further, by moving the probe 5 along the butting portion 2 with the probe 5 inserted into the butting portion 2, friction stir welding is performed over the entire length of the butting portion 2. Next, the deformed portion 6 protruding and deforming into the concave portion 3a of the backing member 3 is cut by a milling machine or the like to obtain a flat surface.
[0013]
[Patent Document 1]
JP-A-10-225780 (paragraphs [0032] to [0036], FIG. 3)
[0014]
[Problems to be solved by the invention]
However, in Patent Literature 1, it is necessary to insert the probe 5 to the back surface of the butting portion 2 in order to cause the back surface of the butting portion 2 to protrude and deform into the concave portion 3 a of the backing member 3. For this reason, especially when the thin joining members 1a and 1b are used, there is a possibility that the joining members 1a and 1b may be damaged.
[0015]
In addition, after the joining process is completed, the backing member 3 must be peeled from the back surface of the butted portion 2. Therefore, a problem has been pointed out that in the thin joining members 1a and 1b, residual strain occurs due to the peeling treatment of the backing member 3.
[0016]
On the other hand, there is a possibility that the backing member 3 may be damaged by peeling, and thus cannot be used repeatedly, which is not economical.
[0017]
The present invention is intended to solve this kind of problem, and in particular, a thin stir plate member can be satisfactorily joined together, and a friction stir welding method capable of reliably removing unjoined portions and maintaining the joining strength, and It is intended to provide a device.
[0018]
[Means for Solving the Problems]
In the friction stir welding method according to the first aspect of the present invention and the friction stir welding apparatus according to the eighth aspect, an opening formed in the backing jig for holding the other surface of the butting portion corresponding to the butting portion. A cushioning member is attached so as to cover the portion. Next, in a state where the first and second plate members are held by the backing jig, a probe is inserted from one surface of the butting portion to deform the buffer member and a part of the butting portion toward the opening. Then, friction stir welding is performed along the butted portion. Then, after the friction stir welding is performed, a portion protruding from the butted portion toward the opening is removed.
[0019]
For this reason, the first and second plate members do not stick to the backing jig, and there is no possibility that the backing jig is damaged by being separated from the first and second plate members. As a result, the backing jig can be used repeatedly and is economical. Further, the first and second plate members are not joined to the cushioning member, so that the buffering member can be easily separated from the cushioning member and effectively prevent residual strain from occurring. Become.
[0020]
In addition, the other surface of the butt portion where an unjoined portion is likely to be generated is protruded and deformed toward the opening of the backing jig, and is removed from the butt portion after the friction stir welding is completed. Therefore, the first and second plate members can reliably remove the unjoined portion, and the strength of the joined portion can be effectively increased to improve the reliability.
[0021]
Further, in the friction stir welding method according to claim 2 of the present invention, after the friction stir welding is performed, only the backing jig is moved from the butting portion in a state where the cushioning member is pressed against the other surface of the butting portion. Be separated. Next, the buffer member is detached from the other surface of the butted portion. For this reason, when the backing jig and the cushioning member are detached from the first and second plate members, residual strain does not occur.
[0022]
Furthermore, in the friction stir welding method according to claim 3 of the present invention and the friction stir welding apparatus according to claim 9, the first and the second surfaces are brought into close contact with the backing jig and the other surface of the butting portion. The ends of the second plate members are regulated to the same length. Therefore, even if the butt portion is particularly thin and has a relatively large diameter, a phase difference due to deformation or wrinkles does not occur due to insertion of the probe, and the roundness of the butt portion can be maintained well. Dimensional accuracy is improved. In addition, it is possible to prevent displacement of the butted portion and to perform accurate positioning, and the friction stir welding process is efficiently performed.
[0023]
Furthermore, in the friction stir welding method according to claim 4 of the present invention and the friction stir welding apparatus according to claim 10, the backing jig has a perfect circular outer peripheral surface, and is closely attached to the outer peripheral surface. The ends of the first and second plate members are restricted to the same circumferential length. Thus, the first and second plate members can be reliably joined to the entire circumference of the butted portion with a simple and economical configuration and process while maintaining the roundness.
[0024]
At this time, the backing jig includes a plurality of split jigs that can be divided and moved in the radial direction, and the buffer member can be integrally fitted into each concave portion formed in each split jig. A friction stir welding method according to claim 4 of the present invention and a friction stir welding apparatus according to claim 11 of the present invention. Therefore, after the friction stir welding, the backing jig can be easily and quickly separated from the butted portion.
[0025]
Further, in the friction stir welding method according to claim 5 of the present invention, the first and second plate members are expanded relative to the backing jig and the first and second plate members are attached to the backing jig. Two plate members are arranged. For example, when the first and second plate members are heated, the first and second plate members thermally expand and the inner peripheral diameter increases. Therefore, the first and second plate members are easily packaged in the backing jig, and contract by cooling to securely adhere to the outer peripheral surface of the backing jig.
[0026]
Further, in the friction stir welding method according to claim 6 of the present invention and the friction stir welding apparatus according to claim 12, a pressing force is applied to the first and second plate members from a direction substantially orthogonal to the insertion direction of the probe. In this state, friction stir welding is performed along the butted portion. Thereby, the end portions of the first and second plate members can be securely press-bonded to each other, and the butted portions can be joined with high quality.
[0027]
Furthermore, in the friction stir welding method according to claim 7 and the friction stir welding apparatus according to claim 13, the first and second plate members are set to a thickness of 2 mm or less. For this reason, even if it is a thin plate member, friction stir welding can be performed favorably, and the occurrence of residual strain in the thin plate member can be effectively prevented.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic configuration explanatory view of an aircraft gas turbine engine 12 incorporating a fan duct 10 in which a friction stir welding method according to a first embodiment of the present invention is performed.
[0029]
The gas turbine engine 12 includes a fan 14, which rotates at a high speed to suck air from outside, compresses the air, and sends the air backward. A fan bypass passage 18 is formed in the vicinity of the fan 14 by the core duct 16 and the fan duct 10, and a thrust is generated in an airframe (not shown) through the air injected rearward through the fan bypass passage 18.
[0030]
The fan 14 forms a low-pressure compressor 20, and the air compressed by the low-pressure compressor 20 is sent to a high-pressure compressor 22 at a subsequent stage. The air compressed by the high-pressure compressor 22 is sent to a combustion chamber 24 at a later stage. The combustion chamber 24 has a fuel nozzle 26 from which fuel is pumped to the combustion chamber 24. In the combustion chamber 24, a mixture of the compressed air fed from the high-pressure compressor 22 and the fuel sprayed from the fuel nozzle 26 is ignited when the engine is started and burns.
[0031]
The combustion of the air-fuel mixture generates a high-temperature high-pressure gas, which is sent to the high-pressure turbine 28 to rotate the high-pressure turbine 28 at a high speed. The high-pressure turbine 28 rotates the rotor 14 a of the fan 14, and the high-temperature high-pressure gas is sent to the low-pressure turbine 30 after driving the high-pressure turbine 28 to rotate. The low-pressure turbine 30 rotates the rotor 14a and the fan 14 of the low-pressure compressor 20.
[0032]
A starter generator 32 that incorporates a starter and a generator is mounted on an external lower surface of the gas turbine engine 12 via an accessory gear box 34.
[0033]
FIG. 2 is an explanatory diagram of a duct structure 40 that constitutes the fan duct 10. The duct structure 40 has a body member (first plate member) 42 formed of a thin plate, for example, an aluminum material having a thickness of 2 mm or less into a substantially cylindrical shape, and a thin plate aluminum material formed into a substantially cylindrical shape. Flange members (second plate members) 44 and 46. The first and second butted portions 48 and 50 in which the ends 42a and 42b of the body member 42 and the ends 44a and 46a of the flange members 44 and 46 abut against each other have outer peripheral surfaces (one surface) 48a and 50a. The friction stir welding is performed, and the body member 42 and the flange members 44 and 46 are joined.
[0034]
FIG. 3 is a partially exploded perspective view of a friction stir welding apparatus 60 according to the first embodiment of the present invention for friction stir welding the duct structure 40, and FIG. FIG.
[0035]
The friction stir welding apparatus 60 includes a base member 64 that is fixed to a rotary table 62 and is rotated, and that integrally holds the body member 42 and the flange members 44 and 46 that have been temporarily joined in advance. A substantially disk-shaped support base 66 is fixed to an upper portion of the base member 64, and a support column 68 is erected at the center of the support base 66 so as to extend in the vertical direction (the direction of arrow A). At the tip of the support column 68, a screw portion 72 constituting the pressing mechanism 70 is formed.
[0036]
The pressing mechanism 70 includes a pressing plate 74. The pressing plate 74 has a substantially disk shape, and has a hole 76 into which a support 68 is inserted in the center. The pressing plate 74 applies a pressing force to the body member 42 and the flange members 44 and 46 disposed on the support base 66 from an arrow A direction substantially perpendicular to an insertion direction (arrow B direction) of a probe 144 (see FIG. 5) described later. Has the function of providing
[0037]
A pressing block 77 is engaged with a central portion of the pressing plate 74, and a nut member 78 screwed to the screw portion 72 presses the pressing plate 74 in the direction of arrow A via the pressing block 77. A suspension bolt 79 is screwed to the tip of the screw portion 72. A plurality of openings 80 and a plurality of openings 82 smaller in diameter than the openings 80 are formed in the pressing plate 74 at equal angular intervals.
[0038]
On the support base 66, a ring portion 86 circling around the support 68 is formed so as to bulge in the direction of arrow A. A first backing jig 88 is detachably provided on the outer periphery of the ring portion 86, and a second backing jig 92 is attached via a rod 90 fixed to the ring portion 86.
[0039]
The first backing jig 88 includes a plurality of, for example, four divided jigs 94a to 94d formed of, for example, an iron-based material, and has a substantially ring shape as a whole. The dividing jigs 94a to 94d are connected to actuators, for example, cylinders 96a to 96d, and are configured to be individually movable in the radial direction.
[0040]
The outer peripheral surface 88a of the first backing jig 88 is set in a perfect circular shape. As shown in FIG. 5, the outer peripheral surface 88a of the first backing jig 88 corresponds to the inner peripheral surface (the other surface) 48b of the first butted portion 48 between the body member 42 and the flange member 44. An orbiting concave portion 97 is provided, and an orifice 99 is formed so as to communicate with the bottom of the concave portion 97 and to orbit.
[0041]
After friction stir welding has been performed on the first butting portion 48, a first buffer member 98 detached from the inner peripheral surface 48 b of the first butting portion 48 is attached to the concave portion 97. The first buffer member 98 is made of, for example, an iron-based material or an aluminum ring material, and has a thickness set to the same dimension as the depth of the concave portion 97, for example, a thickness of about 1 mm. The opening 99 is formed as a concave groove which goes around the outer peripheral surface 88 a of the first backing jig 88 and is narrower than the concave portion 97, and is formed on the inner peripheral surface 48 b of the first butting portion 48 after the friction stir welding. It is limited to a size that can accommodate a region that is likely to be an unjoined portion. For example, when the unjoined portion is 20 μm to 30 μm, the depth of the opening 99 is set to about 50 μm.
[0042]
As shown in FIG. 4, screw holes 100 are formed on the upper surface of the ring portion 86 at predetermined angular intervals, and each of the screw holes 100 has a rod 90 at one end. 102 is screwed. A screw hole 104 is formed in the other end of the rod 90, and the mounting plate 106 is fixed to the rod 90 by screwing a bolt 108 from a mounting plate 106 constituting the second backing jig 92. .
[0043]
As shown in FIGS. 3 and 4, the second backing jig 92 includes, for example, a plurality of division jigs formed of an iron-based material, for example, four division jigs 110 a to 110 d. Has a substantially ring shape. The dividing jigs 110a to 110d are connected to actuators, for example, cylinders 112a to 112d, and are configured to be individually movable in the radial direction on the mounting plate 106.
[0044]
The outer peripheral surface 92a of the second backing jig 92 is formed in a perfect circular shape as a whole. As shown in FIG. 6, the outer peripheral surface 92a of the second backing jig 92 corresponds to the inner peripheral surface (the other surface) 50b of the second butted portion 50 of the body member 42 and the flange member 44. An orbiting concave portion 114 is provided, and an orifice 115 is formed to communicate with the bottom of the concave portion 114 and to orbit.
[0045]
After the friction stir welding has been performed on the second butting portion 50, a second buffer member 116 detached from the inner peripheral surface 50 b of the second butting portion 50 is attached to the concave portion 114. The second cushioning member 116 is made of, for example, an iron-based material or an aluminum ring material, and has a thickness set to the same dimension as the depth of the concave portion 114, for example, a thickness of about 1 mm. . The opening 115 is formed as a concave groove which goes around the outer peripheral surface 92 a of the second backing jig 92 and is narrower than the concave portion 114, and is formed on the inner peripheral surface 50 b of the second butting portion 50 after the friction stir welding. The size is set to be able to accommodate a region that is likely to be an unjoined portion.
[0046]
As shown in FIGS. 3 and 4, the outer peripheral surfaces 88 a and 92 a of the first and second backing jigs 88 and 92 are formed by taking into account the springback of the duct structure 40. When the first and second backing jigs 88 and 92 are expanded in diameter, the maximum outer diameter of the outer peripheral surfaces 88a and 92a is determined by the first and second pre-heating first and second backing jigs. It is larger than the inside diameter of the butted portions 48 and 50.
[0047]
A first clamp jig 117 for holding the first butting portion 48 is disposed on an outer peripheral surface 48 a of the first butting portion 48, and the second butting portion is provided on an outer peripheral surface 50 a of the second butting portion 50. A second clamp jig 118 that holds 50 is arranged.
[0048]
As shown in FIG. 3, the first clamp jig 117 is formed in a belt shape by forming a square material into a ring shape. A screw hole 119 is formed on one end surface of the first clamp jig 117, and a hole 120 is formed on the other end surface. As the bolt 122 is screwed into the screw hole 119 through the hole 120, the first clamp jig 117 is reduced in radial dimension and tightens the outer peripheral surface 48 a of the first butting portion 48.
[0049]
As shown in FIGS. 3 and 4, a plurality of rods 126 are fixed to the outer peripheral edge of the support base 66 via bolts 124. Each rod 126 extends in the direction of arrow A, and is provided with a mounting plate 130 via a bolt 128 screwed into its end. The mounting plate 130 has a substantially ring shape, and a second clamp jig 118 is fixed to the mounting plate 130 via a bolt 132. The second clamp jig 118 is formed in a substantially ring shape, and clamps and holds the outer peripheral surface 50 a of the second butting portion 50.
[0050]
As shown in FIG. 5, the joining machine 140 that joins the first butting portions 48 includes a rotating tool 142. A probe 144 protruding by a predetermined length is provided at the tip of the rotary tool 142. In the probe 144, the length of the probe tip 114a inserted into the first butting portion 48 is set to be shorter than the thickness of the first butting portion 48. The second butting portion 50 may be joined by the above-described joining machine 140 (see FIG. 6), or the joining operation may be performed using an individual joining machine.
[0051]
The operation of the friction stir welding apparatus 60 thus configured will be described below with reference to the flowchart shown in FIG. 7 in relation to the friction stir welding method according to the first embodiment.
[0052]
First, a cylindrical body member 42 and flange members 44 and 46 are manufactured (step S1). Specifically, as shown in FIG. 2, a thin plate-like aluminum material constituting the body member 42 is formed into a substantially cylindrical shape, and friction stir welding (FSW) is performed along a butting portion 42 c where both ends thereof are butted. Then, the butted portions 42c are joined. Thus, a trunk member 42 is obtained.
[0053]
Similarly, after the thin aluminum material forming the flange members 44 and 46 is formed into a substantially cylindrical shape, the butted portions 44c and 46c are joined by friction stir welding. Therefore, the flange members 44 and 46 are obtained.
[0054]
At the time of the above-mentioned friction stir welding, a probe (not shown) is arranged offset by a predetermined distance from the center of the cylindrical shape, thereby effectively preventing the joining surface from being cut.
[0055]
Next, in a state where the ends 44a, 46a of the flange members 44, 46 abut against the ends 42a, 42b of the body member 42, the first and second butting portions 48, 50 are provided with aluminum tape (see FIG. (Not shown) is attached. For this reason, the flange members 44 and 46 are temporarily joined to both sides of the trunk member 42 (step S2). The temporarily joined body member 42 and flange members 44 and 46 are arranged in a heating furnace (not shown) and heated to a predetermined temperature (step S3). The body member 42 and the flange members 44 and 46 heated to the predetermined temperature are set on the base member 64 (Step S4).
[0056]
Specifically, as shown in FIGS. 3 and 4, divided jigs 94 a to 94 g which surround the ring portion 86 and constitute the first backing jig 88 are provided on the support base 66 which constitutes the base member 64. 94d are arranged in a radially inward direction. Accordingly, the first backing jig 88 has the outer peripheral surface 88a maintained at the minimum diameter, and the first cushioning member 98 is disposed corresponding to the concave portion 97 of the outer peripheral surface 88a. 96a to 96d are driven. Therefore, the dividing jigs 94a to 94d move outward in the radial direction, and the outer peripheral surface 88a of the first backing jig 88 expands in diameter, and the first buffer member 98 is pressed and held by the outer peripheral surface 88a.
[0057]
On the other hand, the screw portion 102 of the rod 90 is screwed into the screw hole 100 formed in the ring portion 86. A mounting plate 106 constituting the second backing jig 92 is disposed on the rod 90, and a bolt 108 is screwed into a screw hole 104 of the rod 90 through a hole of the mounting plate 106. Thus, the mounting plate 106 is fixed to each rod 90, and the dividing jigs 110a to 110d are arranged in the radial inner direction.
[0058]
In this state, the second buffer member 116 is disposed on the outer peripheral surface 92a of the second backing jig 92, and the cylinders 112a to 112d are driven to move the dividing jigs 110a to 110d in the radially outward direction. Therefore, the outer peripheral surface 92a expands in diameter, and the second buffer member 116 is pressed and held by the outer peripheral surface 92a.
[0059]
Then, the body member 42 and the flange members 44 and 46 heated to the predetermined temperature are packaged in the first and second backing jigs 88 and 92. In this case, the body member 42 and the flange members 44 and 46 are heated to a predetermined temperature, and the inner diameter is increased by thermal expansion. For this reason, the first and second butting portions 48 and 50 of the body member 42 and the flange members 44 and 46 are connected to the first and second buffer members 98 and 98 disposed on the first and second backing jigs 88 and 92, respectively. 116 is easily packaged.
[0060]
Further, the inner diameter of the body member 42 and the flange members 44 and 46 is reduced by being cooled, and the inner peripheral surfaces 48b and 50b of the first and second butted portions 48 and 50 are connected to the first and second back surfaces. The jigs 88 and 92 are securely fitted in tight contact with the outer peripheral surfaces 88a and 92a, that is, the first and second buffer members 98 and 116 (see FIGS. 5 and 6). The maximum outer diameter of the outer peripheral surfaces 88a, 92a of the first and second backing jigs 88, 92 is larger than the inner diameter of the inner peripheral surfaces 48b, 50b of the first and second butted portions 48, 50 before heating. Because it is big.
[0061]
Here, the outer peripheral surfaces 88a, 92a of the first and second backing jigs 88, 92 have a perfect circular shape, and the first outer surfaces 88a, 92a fit into the concave portions 97, 114 of the outer peripheral surfaces 88a, 92a. The end portions 42a, 44a and the end portions 42b, 46a that are in close contact with the second buffer members 98, 116 are each regulated to the same circumferential length, and are maintained in a perfect circular shape.
[0062]
Next, the pressing plate 74 is arranged on the second backing jig 92, and after the pressing block 77 is covered with the screw portion 72, the nut member 78 is screwed into the screw portion 72. Accordingly, the pressing plate 74 is pressed through the pressing block 77, and a tightening load is applied to the body member 42 and the flange members 44 and 46 in the direction of arrow A. As a result, the first and second butting portions 48 and 50 are pressed and held without any gap (step S5). Then, proceeding to step S6, the aluminum tape (not shown) attached to the first and second butted portions 48 and 50 is removed, and the surface is cleaned.
[0063]
Further, in step S7, the first clamp jig 117 is mounted. The first clamp jig 117 is formed in a belt shape and circulates around the outer periphery of the body member 42 along the end 42a. Then, by inserting the bolt 122 into the hole 120 and screwing the bolt 122 into the screw hole 119, the inner peripheral diameter of the first clamp jig 117 is reduced. Therefore, the first clamp jig 117 clamps and holds the outer peripheral surface of the body member 42.
[0064]
Next, the base member 64 is fixed to the rotary table 62 by screwing (step S8). In this state, as shown in FIG. 8, the rotating tool 142 included in the welding machine 140 moves toward the first butting portion 48 (in the direction of arrow B) while rotating at high speed. Therefore, the probe tip 144a of the probe 144 rotating at a high speed is inserted into the first butting portion 48, and the first butting portion 48 is welded by frictional heat (see FIG. 9).
[0065]
At this time, a pressing force is applied to the first butting portion 48 toward the opening 99 provided in the first backing jig 88. Accordingly, the rear surface of the first buffer member 98 and a part of the first butting portion 48 are protruded and deformed into the opening portion 99, while the probe 144 rotating at high speed makes the first butting under the rotating action of the rotary table 62. The first moving portion 48 relatively moves along the portion 48, and the joining operation is performed over the entire circumference of the first butting portion 48 (step S9).
[0066]
When the joining operation of the first butting portion 48 is completed, the rotary table 62 is stopped, and the joining machine 140 is separated from the first butting portion 48. Further, while the first clamp jig 117 is removed, the second clamp jig 118 is attached (Step S10). The first clamp jig 117 is detached from the body member 42 by removing the bolt 122 from the screw hole 119 to increase the inner peripheral diameter.
[0067]
On the other hand, a plurality of rods 126 are attached to the outer peripheral edge of the support base 66 via bolts 124, and a mounting plate 130 is attached to the tip of the rod 126 via bolts 128. A second clamp jig 118 is mounted on the mounting plate 130 via bolts 132, and the second clamp jig 118 tightens and holds the outer peripheral surface of the body member 42 on the end 42b side.
[0068]
In this state, as shown in FIG. 10, for example, the joining machine 140 is arranged corresponding to the second butting portion 50, and while the probe 144 rotates integrally with the rotating tool 142, the probe tip 144 a of the probe 144 Is inserted into the outer peripheral surface 50a of the second butting portion 50. The second butting portion 50 is rotated with respect to the welding machine 140 under the rotation of the rotary table 62, and the friction stir welding is performed over the entire circumference of the second butting portion 50 (Step S11).
[0069]
As described above, after the first and second butted portions 48 and 50 are joined to obtain the joined duct structure 40, the duct structure 40 is attached to the first and second backing jigs 88. , 92 together with the base member 64 (step S12). Specifically, the division jigs 94a to 94d constituting the first backing jig 88 move inward in the radial direction by driving the cylinders 96a to 96d, and the outer peripheral surface 88a is separated from the first buffer member 98 ( (See FIG. 11). On the other hand, the divided jigs 110a to 110d constituting the second backing jig 92 move inward in the radial direction under the action of the cylinders 112a to 112d, and the outer peripheral surface 92a is separated from the second buffer member 116.
[0070]
Then, the suspension bolt 79 and the nut member 78 are detached from the screw portion 72 to remove the pressing block 77, and the pressing plate 74 is removed from the support 68. Then, the duct structure 40 is taken out from the support base 66 with the first and second buffer members 98 and 116 held on the inner peripheral surface. Next, as shown in FIG. 12, in the first butting portion 48, the first buffer member 98 is separated from the inner peripheral surface of the duct structure 40 (step S13). The inner peripheral surface of the duct structure 40 is provided with a projection 150 which is deformed toward the opening 99 corresponding to the first abutting portion 48, and the projection 150 is formed by cutting or the like. (Step S14). In the second butting section 50, the same operation as that of the first butting section 48 is performed.
[0071]
As described above, in the first embodiment, the concave portions 97 and 114 corresponding to the first and second butted portions 48 and 50 are formed on the outer peripheral surfaces 88a and 92a of the first and second backing jigs 88 and 92. Are formed, and the first and second buffer members 98 and 116 are mounted on the concave portions 97 and 114. For this reason, the outer periphery of the first and second butting portions 48 and 50 is in a state where the first and second buffer members 98 and 116 are in close contact with the inner peripheral surfaces 48b and 50b of the first and second butting portions 48 and 50. Friction stir welding is performed on the surfaces 48a and 50a.
[0072]
Therefore, the first and second butting portions 48 and 50 do not stick to the first and second backing jigs 88 and 92, and the first and second backing jigs 88 and 92 are not attached to the duct structure. There is no danger of breakage due to peeling from the base 40. As a result, the first and second backing jigs 88 and 92 can be repeatedly used, and the effect of being economical is obtained.
[0073]
In addition, as shown in FIG. 9, a concave portion 97 is provided on the outer peripheral surface 88a of the first backing jig 88 so as to correspond to the inner peripheral surface 48b of the first butting portion 48. An opening 99 is formed so as to communicate with the bottom of the nozzle 97 and circulate therearound. The first buffer member 98 is attached to the concave portion 97, and the probe tip 144 a is inserted from the outer peripheral surface 48 a of the first butting portion 48, so that the first buffering member 98 and the first butting portion 48 are connected to each other. A part of the inner peripheral surface 48b is projected and deformed toward the opening 99 side.
[0074]
For this reason, on the inner peripheral surface 48b side where the probe tip 144a does not reach and where an unbonded portion is likely to be generated due to the influence of the peripheral speed of the probe tip 144a, the protrusion 150 is deformed toward the opening 99 side. Is provided. Then, the protrusion 150 is removed from the inner peripheral surface 48b by cutting or the like after the friction stir welding (see FIGS. 12 and 13).
[0075]
Therefore, the duct structure 40 has an effect that the unjoined portion can be surely removed, and the strength of the joined portion can be effectively increased and the reliability can be improved.
[0076]
Also, the first and second butting portions 48 and 50 are not joined to the first and second buffer members 98 and 116, and the first and second buffer members 98 and 116 can be easily separated. Is done. Further, in the duct structure 40, there is no occurrence of residual strain due to the separation of the first and second cushioning members 98 and 116.
[0077]
In particular, the outer peripheral surfaces 88a and 92a of the first and second backing jigs 88 and 92 are formed in a perfect circular shape, and the inner peripheral surfaces 48b and 50b of the first and second butted portions 48 and 50 are The circular shape is maintained in close contact with the outer peripheral surfaces 88a and 92a. In addition, the inner peripheral lengths of the ends 42a, 44a and the circumferential lengths of the ends 42b, 46a are restricted to the same length.
[0078]
Therefore, even if the first and second butted portions 48 and 50 are thin and have a relatively large diameter of 2 mm or less, a phase difference due to deformation, wrinkles, or the like does not occur, and the first and second butted portions 48 and 50 are not affected. The roundness of the second butted portions 48 and 50 can be favorably maintained, and the dimensional accuracy is improved. Thus, the effect of efficiently performing the friction stir welding of the first and second butting portions 48 and 50 can be obtained in a simple and economical process.
[0079]
Further, the first and second butting portions 48 and 50 are fitted in tight contact with the outer peripheral surfaces 88a and 92a of the first and second backing jigs 88 and 92 via the first and second buffer members 98 and 116. Combine. For this reason, the first and second butting portions 48 and 50 are prevented from being shifted from each other, so that accurate positioning can be performed, and the friction stir welding process is efficiently performed.
[0080]
At this time, the first and second butting portions 48 and 50 are fitted to the first and second backing jigs 88 and 92 in a state where the inner peripheral diameter is enlarged by thermal expansion by being heated to a predetermined temperature. I agree. Therefore, the first and second butting portions 48 and 50 can be easily and reliably brought into close contact with the outer peripheral surfaces 88a and 92a of the first and second backing jigs 88 and 92.
[0081]
Furthermore, a pressing force is applied to the body member 42 and the flange members 44 and 46 from the direction (arrow A direction) substantially perpendicular to the insertion direction of the probe 144 (arrow B direction) via the pressing mechanism 70. Thereby, the first and second butting portions 48 and 50 can be securely press-bonded without generating a gap, a high-quality joining process can be performed, and the configuration of the pressing mechanism 70 can be easily configured. Simplify.
[0082]
In the above-described first embodiment, the inner diameter is increased by heating the body member 42 and the flange members 44 and 46 that are temporarily joined by an aluminum tape (not shown) to a predetermined temperature in a heating furnace. Although they are mounted on the first and second backing jigs 88 and 92 with their diameters, the invention is not limited to this. For example, the outer diameter of the first and second backing jigs 88 and 92 may be reduced by cooling the first and second backing jigs 88 and 92.
[0083]
In addition, although the dividing jigs 94a to 94d and 110a to 110d which are respectively divided into four are used, the number of divisions can be variously selected. Further, a drive source such as an electromagnetic solenoid may be used instead of the cylinders 96a to 96d and 112a to 112d. Furthermore, the division jigs 94a to 94d (and / or the division jigs 110a to 110d) can be integrally advanced and retracted via a single drive source.
[0084]
FIG. 14 is a partial perspective view of a friction stir welding apparatus 160 according to the second embodiment of the present invention. The same components as those of the friction stir welding apparatus 60 according to the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.
[0085]
The friction stir welding apparatus 160 includes first and second backing jigs 162 and 164. The first backing jig 162 includes, for example, a plurality of split jigs formed of an iron-based material, for example, four split jigs 94a to 94d, and is disposed inside the split jigs 94a to 94d. A first ring member 166 for expanding the diameter of the dividing jigs 94a to 94d. Similarly to the first backing jig 162, the second backing jig 164 includes, for example, a plurality of, for example, four divided jigs 110a to 110d formed of an iron-based material, and the divided jigs 110a to 110d. And a second ring member 168 that is arranged inside and extends the diameter of the dividing jigs 110a to 110d.
[0086]
In the friction stir welding apparatus 160 configured as described above, the first jigs 94a to 94d constituting the first backing jig 162 are arranged on the outer periphery of the first buffer members 98, and the first jigs 94a to 94d are arranged. The first ring member 166 is inserted inside 94d. Thereby, the diameter of the dividing jigs 94a to 94d is increased, and the first ring member 166 is held in close contact with the outer periphery of the dividing jigs 94a to 94d. Similarly, by inserting the second ring member 168 inside the dividing jigs 110a to 110d constituting the second backing jig 164, the second buffer member is provided on the outer periphery of the dividing jigs 110a to 110d. 116 is closely held.
[0087]
Therefore, in the second embodiment, the same effects as those of the first embodiment can be obtained, and there is an advantage that the configuration is further simplified. Note that a wedge member or the like may be used instead of the first and second ring members 166 and 168.
[0088]
【The invention's effect】
In the friction stir welding method and apparatus according to the present invention, the other surface of the butt portion where an unwelded portion is liable to occur is protruded and deformed toward the opening side of the backing jig, and the butt portion is joined after the friction stir welding is completed. Removed from the part. Therefore, the first and second plate members can reliably remove the unjoined portion, and the strength of the joined portion can be effectively increased to improve the reliability.
[0089]
Further, the backing jig is economical because the backing jig can be used repeatedly without fear of breakage due to peeling from the first and second plate members. In addition, the detachment process of the buffer member is easily performed, and even if the first and second plate members are particularly thin, it is possible to effectively prevent the occurrence of residual strain.
[Brief description of the drawings]
FIG. 1 is a schematic structural explanatory view of an aircraft gas turbine engine incorporating a fan duct in which a friction stir welding method according to an embodiment of the present invention is performed.
FIG. 2 is an explanatory diagram of a duct structure constituting the fan duct.
FIG. 3 is a partially exploded perspective view of the friction stir welding apparatus according to the first embodiment of the present invention for joining the duct structures.
FIG. 4 is an explanatory sectional view of the friction stir welding apparatus.
FIG. 5 is an enlarged explanatory view of a first backing jig.
FIG. 6 is an enlarged explanatory view of a second backing jig.
FIG. 7 is a flowchart of the friction stir welding method.
FIG. 8 is an operation explanatory diagram when the first butting portion is joined.
FIG. 9 is an explanatory cross-sectional view when the first butting portion is joined.
FIG. 10 is an explanatory diagram of the operation when the second butting portion is joined.
FIG. 11 is an operation explanatory view when the first backing jig is separated from the first butting portion.
FIG. 12 is an operation explanatory view when the first buffer member is separated from the first butting portion.
FIG. 13 is an explanatory diagram of an operation when removing an unjoined portion from the first butted portion.
FIG. 14 is a partial perspective view of a friction stir welding apparatus according to a second embodiment of the present invention.
FIG. 15 is an explanatory view of an unjoined portion by friction stir welding.
FIG. 16 is an explanatory diagram showing a method of joining aluminum members of Patent Document 1.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Fan duct 12 ... Gas turbine engine 14 ... Fan 40 ... Duct structure 42 ... Body member 44, 46 ... Flange part 44a, 46a ... End part 48, 50 ... Butt part 48a, 50a, 88a, 92a ... Outer peripheral surface 48b , 50b ... inner peripheral surfaces 60, 160 ... friction stir welding device 62 ... rotary table 64 ... base member 66 ... support base 68 ... column 70 ... pressing mechanism 72 ... screw part 74 ... pressing plate 77 ... pressing blocks 88, 92, 162, 164: Backing jig 90: Rods 94a to 94d, 110a to 110d: Dividing jigs 96a to 96d, 112a to 112d: Cylinders 97, 114: Concave parts 98, 116: Buffer members 99, 115: Opening 117 , 118: clamp jig 130: mounting plate 140: joining machine 144: probe 166, 168: ring member

Claims

By pressing the rotating probe against one surface of the butted portion where the end of the first plate member and the end of the second plate member are butted, the probe is relatively moved along the butted portion. A friction stir welding method for joining the butted portions,
A step of attaching a cushioning member to a backing jig holding the other surface of the butting portion, covering an opening formed corresponding to the butting portion,
In a state where the first and second plate members are held by a backing jig, the probe is inserted from one surface of the butting portion to move the buffer member and a part of the butting portion toward the opening. Performing a friction stir welding along the butted portion while projecting and deforming;
After the friction stir welding is performed, a step of removing a portion protruding from the butt portion to the opening side,
A friction stir welding method comprising:

2. The friction stir welding method according to claim 1, wherein after the friction stir welding is performed, only the backing jig is detached from the butting portion in a state where the buffer member is pressed against the other surface of the butting portion. The step of causing
Removing the cushioning member from the other surface of the butting portion,
Removing a portion projecting toward the opening from the butting portion;
A friction stir welding method comprising:

3. The friction stir welding method according to claim 1, wherein the other end of the butting portion is brought into close contact with the outer peripheral surface of the backing jig, so that the ends of the first and second plate members are brought together. A friction stir welding method wherein the length is regulated to the same length.

4. The friction stir welding method according to claim 1, wherein the backing division jig has a perfect circular outer peripheral surface, and is divided into a plurality of divisional jigs that can freely advance and retreat in a radial direction. 5. Tools,
The jig is provided with a concave portion that communicates with the opening at the bottom and circulates corresponding to the other surface of the butting portion,
In a state in which the ring-shaped buffer member is integrally attached to each concave portion, the ends of the first and second plate members that are in close contact with the outer peripheral surface of the backing jig have the same circumferential length. Friction stir welding method characterized in that it is regulated to:

5. The friction stir welding method according to claim 3, wherein the first and second plate members are relatively expanded with respect to the backing jig, and the first and second plate members are attached to the backing jig. A friction stir welding method comprising disposing a plate member.

The friction stir welding method according to any one of claims 1 to 5, wherein the first and second plate members are applied with a pressing force from a direction substantially perpendicular to a direction in which the probe is inserted. A friction stir welding method characterized by performing friction stir welding along a butt portion.

7. The friction stir welding method according to claim 1, wherein the first and second plate members have a thickness of 2 mm or less. 8.

By pressing the rotating probe against one surface of the butted portion where the end of the first plate member and the end of the second plate member are butted, the probe is relatively moved along the butted portion. A friction stir welding apparatus for joining the butted portions,
A backing jig that disposes the first and second plate members to hold the other surface of the butting portion and separates from the other surface of the butting portion after friction stir welding is performed,
The backing jig has a concave portion corresponding to the other surface of the butting portion,
An opening communicating with the bottom of the concave portion,
Along with
After the friction stir welding is performed on the concave portion, a buffer member detached from the other surface of the butting portion is attached,
A friction stir welding apparatus, wherein a part of the buffer member and the butting portion is protruded and deformed in the opening during friction stir welding.

9. The friction stir welding apparatus according to claim 8, wherein the other end of the butting portion is arranged in close contact with the outer peripheral surface of the backing jig so that the ends of the first and second plate members are the same. A friction stir welding apparatus characterized in that the length is regulated to the length.

The friction stir welding apparatus according to claim 8, wherein the backing jig has a perfect circular outer peripheral surface, and the first and second plate members are fitted into the outer peripheral surface in close contact. A friction stir welding apparatus characterized in that the end portions are restricted to the same circumferential length.

The friction stir welding apparatus according to claim 10, wherein the backing jig includes a division jig that is divided into a plurality of parts and is capable of moving back and forth in the radial direction.
The friction stir welding apparatus according to claim 1, wherein the buffer member is formed in a ring shape that can be integrally fitted into each of the concave portions formed in each of the divided jigs.

The friction stir welding apparatus according to any one of claims 8 to 11, further comprising a pressurizing mechanism for applying a pressing force to the first and second plate members from a direction substantially orthogonal to a direction in which the probe is inserted. A friction stir welding apparatus characterized in that:

The friction stir welding apparatus according to any one of claims 8 to 12, wherein the first and second plate members have a thickness of 2 mm or less.