JP4732571B2

JP4732571B2 - Friction stir welding tool and friction stir welding method

Info

Publication number: JP4732571B2
Application number: JP2000287123A
Authority: JP
Inventors: 武典橋本; 茂利成願; 喜隆長野
Original assignee: Showa Denko KK
Current assignee: Resonac Holdings Corp
Priority date: 2000-09-21
Filing date: 2000-09-21
Publication date: 2011-07-27
Anticipated expiration: 2020-09-21
Also published as: JP2002096183A

Description

【０００１】
【発明の属する技術分野】
この発明は、アルミニウム材やその合金材等の金属材からなる接合部材を接合する際に用いられる摩擦撹拌接合用の接合工具及びこれを用いた摩擦撹拌接合法に関する。
【０００２】
【従来の技術】
摩擦撹拌接合は、固相接合の範疇に入り、接合される金属材の種類に制限を受けないとか、接合に伴う熱歪みが少ない等の優れた利点を有し、近年、船舶、自動車、鉄道車両における床材、壁材、天井材、サスペンションアーム等を製作する際に用いられてきている。
【０００３】
この摩擦撹拌接合の接合方法を、２個の平板状のアルミニウム合金製接合部材を突合せ接合する場合について説明する。
【０００４】
図６及び図７において、（110A）は従来の摩擦撹拌接合用の接合工具である。この接合工具（110A）は、径大の円柱状回転子（111）と、該回転子（111）の先端部の端面（112）の回転中心部に一体に突設された径小のピン状プローブ（113）とを備えたものである。この接合工具（110A）を用い、その回転子（111）を回転させることによりプローブ（113）を回転させる。そして、該プローブ（113）を両接合部材（101a）（101b）の突合せ部（103）中に挿入するとともに、回転子（111）の先端部を両接合部材（101a）（101b）の表面に圧接する。そして、この状態を維持しながら回転子（111）の先端部を突合せ部（103）に沿って移動させる。
【０００５】
すると、プローブ（113）の回転により発生する摩擦熱と、回転子（111）の先端部の端面（112）と両接合部材（101a）（101b）の表面との摺動に伴い発生する摩擦熱とによって、両接合部材（101a）（101b）は回転子（111）の先端部及びプローブ（113）との接触部分近傍にて軟化する。そして、該軟化部中の肉が、回転子（111）の先端部及びプローブ（113）の回転力を受けて撹拌混合されるとともに回転子（111）の先端部の移動に伴って該回転子（111）の先端部及びプローブ（113）の通過溝を埋めるように塑性流動したのち、摩擦熱を急速に失って冷却固化される。この現象が回転子（111）の先端部の移動に伴って順次繰り返されていき、最終的に両接合部材（101a）（101b）が突合せ部（103）において接合一体化（接合部104）されるものである。
【０００６】
ところで、この摩擦撹拌接合法によれば、回転子（110A）の先端部を突合せ部（103）に沿って移動させると、摩擦熱にて軟化した両接合部材（101a）（101b）の軟化部中の肉は、回転子（111）の先端部の進行圧力を受けて両接合部材（101a）（101b）の外面側に排出されるという不具合が生じる。このようになると、肉不足による接合欠陥（例えば空洞部）が接合部（104）の内部に発生したり、肉の排出に伴うバリが接合部（104）の表面に発生したり、更には肉の排出に伴って接合部（104）の肉厚が減少したりして、接合状態の良好な接合継手を得ることができなくなる。
【０００７】
そこで、このような問題を解決するため、従来では、同図６及び図７に示すように、回転子（111）の先端部を移動させるときに該回転子（111）の回転軸線（Ｑ’）を接合方向の後方側（即ち、移動方向の後方側）に傾斜させることによって、図７に示すように該回転子（111）の先端部の端面（112）の接合方向前端部を接合部材（101a）（101b）の表面から浮き上がらせ、この状態を維持したままで該回転子（111）の先端部を突合せ部（103）に沿って移動させることが行われていた。なお、Ｔは両接合部材（101a）（101b）のプローブ挿入位置における表面の法線を示しており、θはこの法線Ｔに対する回転子（111）の回転軸線（Ｑ’）の接合方向後方側への傾斜角である。
【０００８】
この方法では、回転子（111）の先端部の端面（112）の接合方向前端部を両接合部材（101a）（101b）の表面から浮き上がらせた状態に維持したままで、回転子（111）の先端部を移動させることによって、両接合部材（101a）（101b）の肉を回転子（111）の端面（112）で受け止め、これにより当該肉が排出されないよう当該肉を保持し、かかる問題を解決しようとするものである。
【０００９】
【発明が解決しようとする課題】
しかしながら、従来の接合工具（110A）は、図７に示すように、回転子（111）の先端部の端面（112）は平坦面に形成されていたので、接合部材（101a）（101b）の肉を保持することが困難であった。
【００１０】
一方、接合工具として図８に示したもの（10B）が用いられる場合がある。この接合工具（110B）は、回転子（111）の先端部の端面（112）がその外周縁から該端面（112）の回転中心部側に向かって一定勾配をもって窪んだ断面逆Ｖ字状の凹面に形成されるとともに、該回転子（111）の先端部の端面（112）の回転中心部にプローブ（113）が一体に突設されているものである。
【００１１】
しかしながら、この接合工具（110B）を用いて接合を行う場合であっても、接合部材（101a）（101b）の肉の保持力が小さく、かかる問題を完全に解決することができなかった。
【００１２】
さらに、この方法によれば、回転子（111）の回転軸線（Ｑ’）を接合方向後方側に傾斜させた状態のままで移動させなければならないので、接合操作が困難になり、殊に接合線が曲線状になっている場合には接合操作が極めて困難になっていた。
【００１３】
この発明は、このような技術背景に鑑みてなされたもので、その目的は、摩擦熱にて軟化した接合部材の軟化分中の肉をしっかりを保持することができて、接合状態の良好な接合継手を得ることのできる摩擦撹拌接合用接合工具及びこれを用いた摩擦撹拌接合法を提供することにある。
【００１４】
【課題を解決するための手段】
上記目的を達成するため、請求項１の発明に係る接合工具は、先端部が接合部材の表面に圧接される径大の回転子と、接合部材の接合予定部中に挿入される径小のプローブとを備えた摩擦撹拌接合用の接合工具において、回転子の先端部の端面）が、その外周縁から該端面の回転中心部側に向かって窪んだ凹面に形成されており、この端面の回転中心部に、プローブが突設されるとともに、この端面に、プローブを取り巻く態様で渦巻き状又は環状の溝条が設けられていることを特徴としている。
【００１５】
この接合工具において、回転子の先端部の端面が、その外周縁から該端面の回転中心部側に向かって窪んだ凹面に形成されることにより、この端面の内側に、摩擦熱にて軟化した接合部材の軟化部中の肉を収容保持し得るようになる。さらに、この端面に溝条が設けられることにより、収容された肉が溝条内に食い込むようになって、肉の保持力が向上する。この結果、端面の内側に収容保持された肉が接合部材の表面側に排出され難くなり、もって接合状態の良好な接合継手を得ることができるようになる。特に、この溝条が渦巻き状のものである場合には、該溝条内に食い込んだ肉が回転子の回転動作に伴いプローブ側に吸い込まれるように塑性流動されるようになり、この結果、端面の内側に収容保持された肉が更に排出され難くなって、肉の保持力が更に向上し、もってより一層高品質の接合継手が得られるようになる。
【００１６】
請求項２の発明に係る接合工具は、先端部が接合部材の表面に圧接される径大の回転子と、接合部材の接合予定部中に挿入される径小のプローブとを備えた摩擦撹拌接合用の接合工具において、回転子の先端部の端面が、その外周縁から該端面の回転中心部側に向かって窪んだ凹面に形成されており、この端面の回転中心部に、プローブが突設されるとともに、回転子の先端部の外周面に、先端側に進むにつれてプローブ側に段階的に接近する段状部が形成されていることを特徴としている。
【００１７】
この接合工具においては、回転子の先端部の外周面に、先端側に進むにつれてプローブ側に段階的に接近する段状部が形成されていることにより、該回転子の先端部を接合部材の表面に圧接させると、その外周面に形成されている段状部の肩部が接合部材の表面に押し付けられ、これにより該回転子の先端部の外周面が接合部材の表面に強く密着するようになる。この結果、端面の内側に収容保持された接合部材の肉が排出され難くなり、もって接合状態の良好な接合継手を得ることができるようになる。
【００１８】
また、請求項３の発明に係る摩擦撹拌接合法は、上記請求項１又は２記載の接合工具を用いて接合を行う摩擦撹拌接合法であって、プローブを接合部材の接合予定部中に挿入するとともに、回転子の先端部を接合部材の表面に圧接し、この状態で、回転子の回転軸線を接合方向の前方側及び後方側に傾けないで該回転子の先端部を接合予定部に沿って接合部材に対して相対的に移動させることにより、接合を行うことを特徴としている。
【００１９】
この摩擦撹拌接合法によれば、回転子の回転軸線を接合方向の前方側及び後方側に傾けないで該回転子の先端部を接合予定部に沿って相対移動させることにより、接合作業が容易になる。したがって、接合予定部が直線状に延びている場合はもとより、これが曲線状に延びている場合であっても、回転子の先端部をこの接合予定部に沿って容易に相対移動させ得るようになる。
【００２０】
【発明の実施の形態】
次に、この発明の実施形態を図面を参照して説明する。
【００２１】
図１〜図３は、この発明（請求項１）の第１実施形態を示している。図１において、（1a）（1b）は２個の平板状の金属製接合部材である。この実施形態では、各接合部材（1a）（1b）はともにアルミニウム又はその合金からなるものであって、一方の接合部材（1a）の肉厚と他方の接合部材（1b）の肉厚は同寸に設定されている。そして、一方の接合部材（1a）の幅方向の端部と他方の接合部材（1b）の幅方向の端部とが、表面同士が面一に連なる態様にして突き合わされており、且つ、この突合せ状態で支持部材（図示せず）によって両接合部材（1a）（1b）がその裏面側から支持されている。
【００２２】
この実施形態では、こうして突合せ状態に配置された両接合部材（1a）（1b）の突合せ部（３）を該突合せ部（３）に沿って摩擦撹拌接合する場合について示すものである。したがって、両接合部材（1a）（1b）の突合せ部（３）が接合予定部となる。
【００２３】
図１において、（10A）は摩擦撹拌接合用の接合工具である。この接合工具（10A）は、先端部が両接合部材（1a）（1b）の表面に圧接される径大の円柱状回転子（11）と、突合せ部（３）中に挿入される径小のピン状プローブ（13）とを備えている。前記回転子（11）及びプローブ（13）は、両接合部材（1a）（1b）よりも硬質で且つ接合時に発生する摩擦熱に耐えうる耐熱材料から形成されている。
【００２４】
この接合工具（10A）において、図２及び図３に示すように、回転子（11）の先端部の外周面と端面（13）との角部（11a）は、全周に亘って丸く面取りされており、これにより、当該角部（11a）の圧接に伴う両接合部材（1a）（1b）の表面の傷付きを防止し得るものとなされている。そして、該回転子（11）の先端部の端面（12）は、その外周縁から該端面（12）の回転中心部側に向かって一定勾配をもって窪んだ断面逆Ｖ字状の凹面に形成されている。そして、この端面（12）の回転中心部に、前記プローブ（13）が回転子（11）の回転軸線（Ｑ）上に突出して一体に設けられている。
【００２５】
さらに、この回転子（11）の先端部の端面（12）には、図３（イ）に示すように、プローブ（13）の基端部の位置を中心にした２本の渦巻き状の溝条（15）（15）が、互いに１８０°の位相差をもって、プローブ（13）の基端部の外周縁から端面（12）の外周縁に及ぶ領域に亘って該プローブ（13）を取り巻く態様で設けられている。この各溝条（15）は、図３（ロ）に示すように、断面コ字状のものであって、接合時に、この溝条（15）内に、摩擦熱にて軟化した両接合部材（1a）（1b）の軟化部中の肉を食い込ませることで、該端面（12）の内側に収容された肉に対する保持力を向上させるためのものである。この溝条（15）は、幅ｗ1が０．５〜２．０ｍｍ、平均深さｈ1が０．５×ｗ1〜２×ｗ1ｍｍ、回転子（11）の回転軸線（Ｑ）を含む断面において凹面に沿う方向のピッチｐ1が０．５×ｗ1〜３×ｗ1ｍｍの範囲内に設定されていることが、かかる作用を確実に奏し得るようになる点で、望ましい。
【００２６】
一方、プローブ（13）の外周面には、摩擦熱にて軟化した両接合部材（1a）（1b）の軟化部中の肉を撹拌するための断面三角形状の撹拌用凸部（13a）が、該プローブ（13）の略全長に亘って螺旋状に設けられている。この第１実施形態では、このプローブ（13）は、Ｍ５のネジの軸部状に形成されたものであって、ネジ山を撹拌用凸部（13a）とするものである。
【００２７】
以上の構成の接合工具（10A）を用いて両接合部材（1a）（1b）の突合せ部（３）を接合する場合には、図１に示すように、まず回転子（11）をその回転軸線（Ｑ）を中心に所定の回転方向Ｒに回転させ（その回転方向は後述する）、これによりプローブ（13）を一体回転させる。そして、回転しているプローブ（13）を突合せ部（３）中に表面側から挿入するとともに、回転している回転子（11）の先端部を両接合部材（1a）（1b）の表面に圧接させ、更に、回転子（11）の回転軸線（Ｑ）を両接合部材（1a）（1b）のプローブ挿入位置における表面の法線Ｔに一致させる。このとき、回転子（11）の先端部は、両接合部材（1a）（1b）の表面に圧接されることで、図２に示すように両接合部材（1a）（1b）中に僅かに埋入された状態になる。そして、この状態を維持しながら、回転子（11）の先端部を突合せ部（３）に沿って移動させる。この移動方向Ｍが接合方向となる。なお、この発明では、プローブ（13）の突合せ部（３）中への挿入は、両接合部材（1a）（1b）の長さ方向の一端面から行っても良いことはもちろんである。
【００２８】
すると、プローブ（13）の回転により発生する摩擦熱と、回転子（11）の先端部の端面（12）と両接合部材（1a）（1b）の表面との摺動に伴い発生する摩擦熱とによって、両接合部材（1a）（1b）は、回転子（11）の先端部及びプローブ（13）との接触部分近傍において軟化する。そして、両接合部材（1a）（1b）の軟化部中の肉は、回転子（11）の先端部からの圧接力を受けることによって該回転子（11）の先端部の端面（12）内に収容保持され、もって当該肉が両接合部材（1a）（1b）の外面側に排出され難くなる。さらには、こうして回転子（11）の先端部からの圧接力を受けることによって、当該肉が溝条（15）内に食い込んで、当該肉の排出がより強く阻止されるようになる。
【００２９】
こうして回転子（11）の先端部の端面（12）の内側に収容保持された両接合部材（1a）（1b）の肉は、回転子（11）の先端部及びプローブ（13）の回転力を受けることによって撹拌混合されるとともに、回転子（11）の先端部の移動に伴って該先端部及びプローブ（13）の通過溝を埋めるように塑性流動したのち、摩擦熱を急速に失って冷却固化される。この現象が回転子（11）の先端部の移動に伴って順次繰り返されていき、最終的に両接合部材（1a）（1b）が突合せ部（３）において接合一体化され、もって所望する突合せ接合継手が得られる。図１において、（４）は、両接合部材（1a）（1b）の突合せ部（３）に形成された接合部を示している。
【００３０】
ここで、この第１実施形態では、回転子（11）の回転方向Ｒは、図３（イ）に示すように、回転子（11）の先端側から見て、溝条（15）がプローブ（13）の周りをプローブ（13）から遠ざかりながら回転する方向に、設定されている。このように設定することにより、溝条（15）内に食い込んだ肉が端面（12）の回転動作に伴いプローブ（13）側に吸い込まれるように塑性流動されるようになり、このため、肉の排出をより一層強く阻止できるようになって、より一層良好な接合部（４）を形成できるようになる。
【００３１】
以上の摩擦撹拌接合法においては、接合工具（10A）として、回転子（11）の先端部の端面（12）が上述したような凹面に形成されており且つこの端面（12）に上述した渦巻き状の溝条（15）が設けられたものが用いられているから、接合の際に回転子（11）の回転軸線（Ｑ）を接合方向（Ｍ）後方側に傾斜させなくても、両接合部材（1a）（1b）の肉を端面（12）の内側にしっかりと収容保持することができる。したがって、この接合工具（10A）によれば、回転子（11）の回転軸線（Ｑ）を両接合部材（1a）（1b）のプローブ挿入位置における表面の法線Ｔに一致させた状態で、回転子（11）の先端部の移動操作（接合操作）を行うことができる。このため、突合せ部（３）がこの実施形態のように直線状に延びている場合はもとより、これが曲線状に延びている場合（図示せず）であっても、回転子（11）の先端部の移動操作を容易に行うことができるようになる。
【００３２】
さらに、この接合工具（10A）によれば、両接合部材（1a）（1b）の肉を端面（12）の内側にしっかりと収容保持できるようになっているから、肉不足による接合欠陥（空洞部等）を防止できるし、肉の排出に伴うバリの発生を防止できるし、更には、肉の排出に伴って接合部（４）の肉厚が減少する不具合を防止することもできる。したがって、この接合工具（10A）を用いて接合を行うことにより、接合状態の良好な突合せ接合継手を得ることができる。
【００３３】
なお、この発明では、渦巻き状の溝条（15）は、１本であっても良いし、３本等の複数本であっても良いことはもちろんである。
【００３４】
図４は、この発明（請求項１）の第２実施形態の接合工具（10B）を示している。同図には、上記第１実施形態の接合工具（10A）と同じ要素に、同一の符号が付されている。
【００３５】
この接合工具（10B）においては、回転子（11）の先端部の端面（12）には、該端面（12）の回転中心部を中心にした、互いに半径の異なる３本の環状の溝条（16）（16）（16）が、プローブ（13）を取り囲む態様で同心状に設けられている。この溝条（16）における望ましい幅ｗ2、平均深さｈ2及びピッチｐ2は、上記第１実施形態の接合工具（10A）の溝条（15）の場合と同じである。
【００３６】
この接合工具（10B）の他の構成は、上記第１実施形態の接合工具（10A）と同一である。また、この接合工具（10B）を用いて接合を行う接合方法についても、上記第１実施形態で示された接合方法と同じであり、重複する説明を省略する。
【００３７】
この接合工具（10B）によれば、回転子（11）の先端部からの圧接力を受けることによって、両接合部材（1a）（1b）の肉が回転子（11）の先端部の端面（12）の内側に収容保持される。さらに、当該肉が溝条（16）内に食い込むことにより、当該肉の排出がより強く阻止されるようになり、もって接合状態の良好な突合せ接合継手を得ることができるようになる。
【００３８】
なお、この発明では、環状の溝条（16）は、１個であっても良いし、３本等の複数個であっても良いことはもちろんである。
【００３９】
図５は、この発明（請求項２）の第３実施形態の接合工具（10C）を示している。同図には、上記第１実施形態の接合工具（10A）と同じ要素に、同一の符号が付されている。
【００４０】
この接合工具（10C）においては、回転子（11）の先端部の端面（12）には溝条（15）が設けられておらず、回転子（11）の先端部の外周面に、先端側に進むにつれてプローブ（13）側に段階的に接近する断面Ｌ字状の２段の段状部が、該回転子（11）の回転軸線（Ｑ）を中心にして全周に亘って形成されている。図５（ロ）において、（17）（17）は段状部の肩部を示している。
【００４１】
この接合工具（10C）の他の構成は、上記第１実施形態の接合工具（10A）と同一であり、またこの接合工具（10C）を用いて接合を行う接合方法についても、上記第１実施形態で示された接合方法と同じであり、重複する説明を省略する。
【００４２】
この接合工具（10C）によれば、回転子（11）の先端部の外周面に２段の段状部が形成されているので、接合の際に、該回転子（11）の先端部を両接合部材（1a）（1b）の表面に圧接することによって、これら２段の段状部の肩部（17）（17）を両接合部材（1a）（1b）の表面に押し付けることができるようになり、これにより、該回転子（11）の先端部の外周面を両接合部材（1a）（1b）の表面に強く密着させることができるようになる。この結果、端面（12）の内側に収容保持された両接合部材（1a）（1b）の肉が排出され難くなり、もって接合状態の良好な突合せ接合継手を得ることができるようになる。
【００４３】
この接合工具（10C）において、各段状部は、段差ｓが０．３〜１ｍｍの範囲内に設定されていることが、上述した作用を確実に奏し得るようになる点で、望ましい。
【００４４】
なお、この発明では、段状部の段数は、１段であっても良いし、３段等の複数段であっても良いことはもちろんである。
【００４５】
以上、この発明の第１〜第３実施形態について説明したが、この発明はこれら実施形態に限定されるものではなく、様々に設定変更可能である。
【００４６】
例えば、接合工具の回転子（11）の先端部の端面（12）は、その外周縁から該端面（12）の回転中心部側に向かって窪んだ断面円弧状の凹面に形成されていても良い。
【００４７】
また、接合工具は、回転子（11）の先端部の外周面に段状部が形成され、且つ該回転子（11）の先端部の端面（12）に渦巻き状の溝条（15）又は環状の溝条（16）が設けられたものであっても良い。
【００４８】
また、接合操作については、接合工具の回転子（11）の先端部の位置を固定しておき、突合せ部（３）が順次、回転子（11）の先端部を通過するように両接合部材（1a）（1b）を移動させることにより、接合を行っても良い。
【００４９】
【実施例】
次に、この発明の具体的実施例を示す。
【００５０】
＜実施例１＞
平板状のアルミニウム合金からなる２個の同形同寸の接合部材（材質：Ａ６０６３−Ｔ５、寸法：長さ２００ｍｍ×幅１００ｍｍ×厚さ４ｍｍ）を準備した。そして、一方の接合部材の幅方向の端部と他方の接合部材の幅方向の端部とを、表面同士が面一に連なる態様で突き合わせた。そして、両接合部材の突合せ部を、図１〜図３に示された上記第１実施形態の接合工具（10A）を用いて上記第１実施形態の接合方法に従って全長に亘って接合した。ここでは、回転子の回転軸線Ｑを両接合部材のプローブ挿入位置における表面の法線Ｔに一致させた状態で、すなわち、法線Ｔに対する回転子の回転軸線Ｑの接合方向後方側への傾斜角θを０°に設定して、接合を行った。
【００５１】
この接合の際に使用された接合工具（10A）は、プローブ（13）がＭ５のネジの軸部状に形成されているものであって、回転子（11）の先端部の外径が１５ｍｍ、プローブ（13）の長さが４ｍｍのものである。また、この接合工具（10A）の溝条（15）の寸法及びこの接合の際に適用された接合条件は、次の通りである。
【００５２】
［接合工具の溝条の寸法］
・溝条の幅ｗ1…１ｍｍ
・溝条の平均深さｈ1…１ｍｍ
・溝条のピッチｐ1…１ｍｍ
［接合条件］
・回転子の回転数…１０００ｒｐｍ
・接合速度…６００ｍｍ／ｍｉｎ
＜実施例２＞
両接合部材の突合せ部を、図４に示された上記第２実施形態の接合工具（10B）を用いて全長に亘って接合した。この接合の際に使用された接合工具（10B）の溝条の寸法及びこの接合の際に適用された接合条件は、次の通りである。他の接合工具の寸法及び接合条件は、上記実施例１と同じである。
【００５３】
［接合工具の溝条の寸法］
・溝条の幅ｗ2…１ｍｍ
・溝条の平均深さｈ2…１ｍｍ
・溝条のピッチｐ2…１ｍｍ
＜実施例３＞
両接合部材の突合せ部を、図５に示された上記第３実施形態の接合工具（10C）を用いて全長に亘って接合した。この接合の際に使用された接合工具（10C）の段状部の寸法及びこの接合の際に適用された接合条件は、次の通りである。他の接合工具の寸法及び接合条件は、上記実施例１と同じである。
【００５４】
［接合工具の段状部の寸法］
・段状部の段差ｓ…０．５ｍｍ
＜比較例１＞
両接合部材の突合せ部を、図７に示された接合工具（110A）を用いて全長に亘って接合した。他の接合条件は上記実施例１と同じである。
【００５５】
＜比較例２＞
両接合部材の突合せ部を、図８に示された接合工具（110B）を用いて全長に亘って接合した。他の接合条件は上記実施例１と同じである。
【００５６】
＜比較例３＞
両接合部材の突合せ部を、図８に示された接合工具（110B）を用いて全長に亘って接合した。ここでは、法線Ｔに対する回転子の回転軸線の接合方向後方側への傾斜角θを３°に設定して、接合を行った。他の接合条件は上記実施例１と同じである。
【００５７】
以上の実施例１〜３及び比較例１〜３で得られた突合せ接合継手について、接合部の表面状態を肉眼にて調べ、また接合部の内部欠陥の有無をＸ線試験により調べた。この結果を表１に示す。
【００５８】
【表１】

【００５９】
なお、表１中の「接合部の表面状態」の欄において、×は接合部の表面状態が不良であるものを示している。一方、△、○、◎は接合部の表面状態が良好であるものを示すとともに、この順に表面状態が良好であることを示している。
【００６０】
表１に示すように、実施例１〜３では、いずれも、接合部の表面状態が良好であり、しかも接合部に空洞部等の内部欠陥が生じておらず、更には接合部の肉厚が殆ど減少していなかったことから、接合の際に回転子の回転軸線を接合方向後方側に傾斜させなくても、良好な接合部を形成できることが分かった。特に、実施例１では、表面状態の極めて良好な接合部を形成することができ、したがって極めて高品質の突合せ接合継手を得ることができることを確認し得た。
【００６１】
一方、比較例１及び２では、接合部に空洞部等の内部欠陥が生じてしまい、良好な接合部を形成できないことが分かった。また、比較例１では、接合部の表面にバリが発生してしまい、表面状態が不良になることが分かった。
【００６２】
【発明の効果】
上述の次第で、請求項１の発明に係る接合工具は、回転子の先端部の端面が、その外周縁から該端面の回転中心部側に向かって窪んだ凹面に形成されており、この端面の回転中心部に、プローブが突設されるとともに、この端面に、プローブを取り巻く態様で渦巻き状又は環状の溝条が設けられているものなので、この接合工具によれば、接合時に、回転子の先端部の端面の内側に、摩擦熱にて軟化した接合部材の軟化部中の肉を収容保持することができるし、その上、収容された肉を溝条内に食い込ませることができるから、該肉をしっかりと保持することができて、肉の排出を抑制できるようになる。したがって、この接合工具によれば、接合の際に、回転子の回転軸線を接合方向の後方側に傾斜させなくても、良好な接合部を形成することができる。特に、溝条が渦巻き状のものである場合には、肉をよりしっかりと保持することができる。したがって、肉の排出をより一層抑制することができるようになって、より一層良好な接合部を形成できるようになる。
【００６３】
請求項２の発明に係る接合工具は、回転子の先端部の端面が、その外周縁から該端面の回転中心部側に向かって窪んだ凹面に形成されており、この端面の回転中心部に、プローブが突設されるとともに、回転子の先端部の外周面に、先端側に進むにつれてプローブ側に段階的に接近する段状部が形成されているものなので、この接合工具によれば、接合時に、回転子の先端部を接合部材の表面に圧接させることにより、その外周面に形成されている段状部の肩部を接合部材の表面に押し付けることができて、該回転子の先端部の外周面を接合部材の表面に強く密着させることができる。したがって、端面の内側に収容保持された接合部材の肉の排出を抑制することができるようになる。したがって、この接合工具によれば、接合の際に、回転子の回転軸線を接合方向の後方側に傾斜させなくても、良好な接合部を形成することができる。
【００６４】
また、請求項３の発明に係る摩擦撹拌接合法は、上記請求項１又は２記載の接合工具を用いて接合を行う摩擦撹拌接合法において、プローブを接合部材の接合予定部中に挿入するとともに、回転子の先端部を接合部材の表面に圧接し、この状態で、回転子の回転軸線を接合方向の前方側及び後方側に傾けないで該回転子の先端部を接合線に沿って接合部材に対して相対的に移動させることにより、接合を行うものであるから、接合予定部が直線状に延びている場合はもとより、これが曲線状に延びている場合であっても、回転子の先端部をこの接合予定部に沿って容易に相対移動させることができるようになって、接合操作を容易に行うことができるようになる。
【図面の簡単な説明】
【図１】この発明の第１実施形態の接合工具を用いて接合を行う場合における接合途中の状態を示す斜視図である。
【図２】図１中のII−II線拡大断面図である。
【図３】（イ）は第１実施形態の接合工具を先端側から視た底面図、（ロ）は（イ）中のIII−III線断面図である。
【図４】（イ）は第２実施形態の接合工具を先端側から視た底面図、（ロ）は（イ）中のIV−IV線断面図である。
【図５】（イ）は第３実施形態の接合工具の半断面側面図、（ロ）は（イ）中のＡ部分の拡大断面図である。
【図６】従来の接合工具を用いて接合を行う場合における接合途中の状態を示す斜視図である。
【図７】図６中のVII−VII線の拡大断面図である。
【図８】従来のもう一つの接合工具を示す、図７に対応する拡大断面図である。
【符号の説明】
１…接合部材
３…突合せ部（接合予定部）
４…接合部
10A…第１実施形態の接合工具
10B…第２実施形態の接合工具
10C…第３実施形態の接合工具
11…回転子
12…端面
13…プローブ
15…渦巻き状の溝条
16…環状の溝条
17…段状部の肩部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a friction stir welding tool for use in joining a joining member made of a metal material such as an aluminum material or an alloy material thereof, and a friction stir welding method using the same.
[0002]
[Prior art]
Friction stir welding is in the category of solid-phase bonding, and has excellent advantages such as not being limited by the type of metal material to be bonded, and less thermal distortion associated with bonding. It has been used when manufacturing floor materials, wall materials, ceiling materials, suspension arms and the like in vehicles.
[0003]
A method of this friction stir welding will be described for a case where two flat aluminum alloy joining members are butt-joined.
[0004]
6 and 7, (110A) is a conventional welding tool for friction stir welding. This joining tool (110A) has a large-diameter columnar rotor (111) and a small-diameter pin-like projecting integrally at the center of rotation of the end surface (112) of the tip of the rotor (111). And a probe (113). Using the joining tool (110A), the probe (113) is rotated by rotating the rotor (111). Then, the probe (113) is inserted into the abutting portion (103) of both joining members (101a) (101b), and the tip of the rotor (111) is placed on the surface of both joining members (101a) (101b). Press contact. Then, while maintaining this state, the tip of the rotor (111) is moved along the butted portion (103).
[0005]
Then, frictional heat generated by the rotation of the probe (113) and frictional heat generated by sliding between the end surface (112) of the tip of the rotor (111) and the surfaces of the joint members (101a) (101b). As a result, the joint members (101a) and (101b) are softened in the vicinity of the contact portion between the tip of the rotor (111) and the probe (113). Then, the meat in the softened portion is stirred and mixed by receiving the rotational force of the tip of the rotor (111) and the probe (113), and the rotor as the tip of the rotor (111) moves. After plastically flowing so as to fill the tip of (111) and the passage groove of the probe (113), it rapidly loses frictional heat and solidifies by cooling. This phenomenon is repeated in sequence with the movement of the tip of the rotor (111), and finally the joint members (101a) and (101b) are joined and integrated (joined portion 104) at the butted portion (103). Is.
[0006]
By the way, according to this friction stir welding method, when the tip of the rotor (110A) is moved along the butted portion (103), the softened portion of both the joined members (101a) and (101b) softened by frictional heat. The inside meat receives the advancing pressure at the tip of the rotor (111) and is discharged to the outer surface side of both joint members (101a) (101b). In this case, a joint defect (for example, a cavity) due to lack of meat occurs inside the joint (104), a burr accompanying discharge of meat occurs on the surface of the joint (104), and further, As a result of the discharge, the thickness of the joint portion (104) decreases, and it becomes impossible to obtain a joint joint with a good joint state.
[0007]
Therefore, in order to solve such a problem, conventionally, as shown in FIGS. 6 and 7, when the tip of the rotor (111) is moved, the rotation axis (Q ′ of the rotor (111) is moved. ) To the rear side in the joining direction (that is, the rear side in the moving direction), as shown in FIG. 7, the joining direction front end portion of the end surface (112) of the tip portion of the rotor (111) is joined to the joining member. (101a) (101b) is lifted from the surface, and the tip of the rotor (111) is moved along the butted portion (103) while maintaining this state. T represents the normal line of the surface at the probe insertion position of both the joining members (101a) and (101b), and θ represents the rearward direction of the rotation axis (Q ′) of the rotor (111) with respect to the normal line T. The tilt angle to the side.
[0008]
In this method, the rotor (111) is maintained while the front end in the joining direction of the end surface (112) of the tip of the rotor (111) is lifted from the surfaces of both joining members (101a) (101b). By moving the tip part of the rotor, the meat of both joint members (101a) (101b) is received by the end face (112) of the rotor (111), thereby holding the meat so that the meat is not discharged, such a problem. Is to solve.
[0009]
[Problems to be solved by the invention]
However, in the conventional joining tool (110A), as shown in FIG. 7, since the end surface (112) of the tip of the rotor (111) is formed as a flat surface, the joining member (101a) (101b) It was difficult to hold the meat.
[0010]
On the other hand, the joining tool (10B) shown in FIG. 8 may be used. This joining tool (110B) has an inverted V-shaped cross section in which the end surface (112) of the tip of the rotor (111) is recessed from the outer peripheral edge toward the rotation center of the end surface (112) with a constant gradient. A probe (113) is integrally formed at the center of rotation of the end surface (112) of the tip of the rotor (111).
[0011]
However, even when joining is performed using the joining tool (110B), the meat holding force of the joining members (101a) and (101b) is small, and this problem cannot be completely solved.
[0012]
Further, according to this method, since the rotation axis (Q ′) of the rotor (111) must be moved while being tilted rearward in the joining direction, the joining operation becomes difficult. When the line is curved, the joining operation has become extremely difficult.
[0013]
The present invention has been made in view of such a technical background, and the object of the present invention is to hold firmly the meat in the softened portion of the joining member softened by frictional heat, and to achieve a good joined state. It is an object of the present invention to provide a friction stir welding joining tool capable of obtaining a joint joint and a friction stir welding method using the same.
[0014]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, a joining tool according to the invention of claim 1 includes a large-diameter rotor whose tip is pressed against the surface of the joining member, and a small-diameter inserted into the joining planned portion of the joining member. In a welding tool for friction stir welding provided with a probe, the end surface of the end of the rotor is formed as a concave surface recessed from the outer peripheral edge toward the rotation center side of the end surface. A probe protrudes from the center of rotation, and a spiral or annular groove is provided on the end face so as to surround the probe.
[0015]
In this joining tool, the end surface of the tip portion of the rotor is formed as a concave surface that is recessed from the outer peripheral edge toward the rotation center portion side of the end surface, so that it is softened by frictional heat inside the end surface. The meat in the softened part of the joining member can be accommodated and held. Further, by providing the groove on the end face, the stored meat bites into the groove and the holding power of the meat is improved. As a result, the meat housed and held inside the end face is not easily discharged to the surface side of the joining member, and a joined joint with a good joined state can be obtained. In particular, when the groove is spiral, the meat that has bitten into the groove is plastically flowed so as to be sucked into the probe side as the rotor rotates. The meat accommodated and held inside the end face is more difficult to be discharged, and the holding power of the meat is further improved, so that a higher quality joint joint can be obtained.
[0016]
A welding tool according to a second aspect of the present invention is a friction stirrer provided with a large-diameter rotor whose tip is pressed against the surface of the joining member, and a small-diameter probe inserted into a joining-scheduled portion of the joining member. In a welding tool for joining, the end surface of the tip of the rotor is formed as a concave surface that is recessed from the outer peripheral edge toward the rotation center of the end surface, and the probe projects into the center of rotation of the end surface. And a stepped portion that gradually approaches the probe side as it advances toward the distal end side is formed on the outer peripheral surface of the distal end portion of the rotor.
[0017]
In this joining tool, a stepped portion that gradually approaches the probe side as it advances toward the distal end side is formed on the outer peripheral surface of the distal end portion of the rotor, so that the distal end portion of the rotor is connected to the joining member. When pressed against the surface, the shoulder of the stepped portion formed on the outer peripheral surface is pressed against the surface of the joining member, so that the outer peripheral surface of the tip of the rotor is in close contact with the surface of the joining member. become. As a result, the meat of the joining member accommodated and held inside the end face is not easily discharged, and a joined joint having a good joined state can be obtained.
[0018]
Further, the friction stir welding method according to the invention of claim 3 is a friction stir welding method for joining using the joining tool according to claim 1 or 2, wherein the probe is inserted into the joining portion of the joining member. At the same time, the front end of the rotor is pressed against the surface of the joining member, and in this state, the front end of the rotor is used as a planned joining portion without tilting the rotation axis of the rotor toward the front side and the rear side in the joining direction. It is characterized by joining by moving relatively with respect to a joining member along.
[0019]
According to this friction stir welding method, the joining operation is facilitated by relatively moving the tip of the rotor along the planned joining portion without tilting the rotation axis of the rotor toward the front side and the rear side in the joining direction. become. Therefore, not only when the planned joining portion extends linearly, but also when this is extended in a curved shape, the tip of the rotor can be easily moved relatively along the planned joining portion. Become.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
[0021]
1 to 3 show a first embodiment of the present invention (claim 1). In FIG. 1, (1a) and (1b) are two flat metal joining members. In this embodiment, each joining member (1a) (1b) is made of aluminum or an alloy thereof, and the thickness of one joining member (1a) and the thickness of the other joining member (1b) are the same. The size is set. And the edge part of the width direction of one joining member (1a) and the edge part of the width direction of the other joining member (1b) are faced | matched by the aspect which surfaces are mutually connected, and this Both joining members (1a) and (1b) are supported from the back side thereof by a support member (not shown) in the butted state.
[0022]
In this embodiment, a case where the abutting portions (3) of both the joining members (1a) and (1b) thus arranged in the abutting state are subjected to friction stir welding along the abutting portions (3) is shown. Therefore, the butted portion (3) of both the joining members (1a) and (1b) is a portion to be joined.
[0023]
In FIG. 1, (10A) is a welding tool for friction stir welding. This joining tool (10A) has a cylindrical rotor (11) having a large diameter whose tip is pressed against the surfaces of both joining members (1a) (1b), and a small diameter inserted into the butting part (3). Pin-shaped probe (13). The rotor (11) and the probe (13) are made of a heat-resistant material that is harder than both the joining members (1a) and (1b) and can withstand frictional heat generated during joining.
[0024]
In this joining tool (10A), as shown in FIGS. 2 and 3, the corner (11a) between the outer peripheral surface of the tip of the rotor (11) and the end surface (13) is rounded over the entire circumference. Thus, it is possible to prevent the surface of both the joining members (1a) and (1b) from being damaged due to the pressure contact of the corner portion (11a). And the end surface (12) of the front-end | tip part of this rotor (11) is formed in the concave surface of an inverted V-shaped cross section which was depressed with the fixed gradient toward the rotation center part side of this end surface (12) from the outer periphery. ing. The probe (13) protrudes on the rotation axis (Q) of the rotor (11) and is provided integrally with the center of rotation of the end face (12).
[0025]
Further, on the end surface (12) of the distal end portion of the rotor (11), as shown in FIG. 3 (a), two spiral grooves centered on the position of the proximal end portion of the probe (13). A mode in which the strips (15) and (15) surround the probe (13) over a region extending from the outer peripheral edge of the proximal end of the probe (13) to the outer peripheral edge of the end face (12) with a phase difference of 180 ° from each other. Is provided. Each groove (15) has a U-shaped cross section as shown in FIG. 3 (B), and both joint members softened by frictional heat in the groove (15) at the time of joining. (1a) It is for improving the holding power with respect to the meat accommodated inside the end face (12) by biting the meat in the softened portion of (1b). The groove (15) has a width w1 of 0.5 to 2.0 mm, an average depth h1 of 0.5 × w1 to 2 × w1 mm, and is concave in the cross section including the rotation axis (Q) of the rotor (11). It is desirable that the pitch p1 in the direction along the line is set within the range of 0.5 × w1 to 3 × w1 mm in order to reliably achieve such an action.
[0026]
On the other hand, on the outer peripheral surface of the probe (13), there is a stirring convex part (13a) having a triangular cross section for stirring the meat in the softened part of both joint members (1a) and (1b) softened by frictional heat. The probe (13) is provided in a spiral shape over substantially the entire length. In the first embodiment, the probe (13) is formed in the shape of a shaft portion of an M5 screw, and has a thread as a stirring convex portion (13a).
[0027]
When joining the butting portions (3) of both joining members (1a) and (1b) using the joining tool (10A) having the above configuration, the rotor (11) is first rotated as shown in FIG. The probe is rotated in a predetermined rotation direction R around the axis (Q) (the rotation direction will be described later), thereby rotating the probe (13) integrally. Then, the rotating probe (13) is inserted into the abutting portion (3) from the surface side, and the tip of the rotating rotor (11) is placed on the surfaces of both joining members (1a) (1b). Further, the rotation axis (Q) of the rotor (11) is made to coincide with the surface normal T at the probe insertion position of both the joining members (1a) and (1b). At this time, the tip of the rotor (11) is pressed into contact with the surfaces of the joint members (1a) and (1b), so that the joint members (1a) and (1b) are slightly in contact with each other as shown in FIG. It becomes the state of being buried. Then, while maintaining this state, the tip of the rotor (11) is moved along the butted portion (3). This moving direction M becomes the joining direction. In the present invention, it goes without saying that the probe (13) may be inserted into the butting portion (3) from one end face in the length direction of both the joining members (1a) and (1b).
[0028]
Then, frictional heat generated by the rotation of the probe (13) and frictional heat generated by sliding between the end surface (12) of the tip of the rotor (11) and the surfaces of the joint members (1a) (1b). Thus, both the joining members (1a) and (1b) are softened in the vicinity of the contact portion between the tip of the rotor (11) and the probe (13). And the meat in the softened part of both joining members (1a) and (1b) receives the pressure contact force from the front end part of the rotor (11), and thereby the end surface (12) of the front end part of the rotor (11) So that the meat is less likely to be discharged to the outer surface side of both the joining members (1a) and (1b). Furthermore, by receiving the pressing force from the tip of the rotor (11) in this way, the meat bites into the groove (15), and the discharge of the meat is more strongly prevented.
[0029]
Thus, the meat of the joint members (1a) (1b) housed and held inside the end face (12) of the tip of the rotor (11) is the rotational force of the tip of the rotor (11) and the probe (13). In addition to stirring and mixing, the frictional heat is lost rapidly after plastic flow to fill the passage groove of the tip and the probe (13) as the tip of the rotor (11) moves. Cooled and solidified. This phenomenon is repeated in sequence with the movement of the tip of the rotor (11), and finally the joint members (1a) and (1b) are joined and integrated at the butting portion (3). A joint joint is obtained. In FIG. 1, (4) has shown the junction part formed in the butt | matching part (3) of both joining members (1a) (1b).
[0030]
Here, in the first embodiment, the rotation direction R of the rotor (11) is such that the groove (15) is a probe as viewed from the front end side of the rotor (11) as shown in FIG. It is set in a direction to rotate around (13) away from the probe (13). By setting in this way, the meat that has bitten into the groove (15) is plastically flowed so as to be sucked into the probe (13) side as the end face (12) rotates, and therefore the meat It becomes possible to more strongly prevent the discharge, and it is possible to form an even better joint (4).
[0031]
In the friction stir welding method described above, the end surface (12) of the tip of the rotor (11) is formed as a concave surface as described above as the welding tool (10A), and the spiral described above is formed on this end surface (12). Since a groove provided with a groove-like groove (15) is used, both the rotation axes (Q) of the rotor (11) do not have to be inclined backward in the joining direction (M) during joining. The meat of the joining members (1a) and (1b) can be firmly accommodated and held inside the end face (12). Therefore, according to this joining tool (10A), in a state where the rotation axis (Q) of the rotor (11) is matched with the surface normal T at the probe insertion position of both joining members (1a) (1b), The moving operation (joining operation) of the tip of the rotor (11) can be performed. For this reason, not only when the butting portion (3) extends linearly as in this embodiment, the tip of the rotor (11) even when it extends in a curved shape (not shown) The moving operation of the part can be easily performed.
[0032]
Furthermore, according to this joining tool (10A), the meat of both joining members (1a) and (1b) can be firmly accommodated and held inside the end face (12). And the like can be prevented, and the occurrence of burrs associated with meat discharge can be prevented, and further, the problem that the thickness of the joint portion (4) decreases as the meat is discharged can be prevented. Therefore, by joining using this joining tool (10A), a butt joint having a good joined state can be obtained.
[0033]
In the present invention, the spiral groove (15) may be a single groove or a plurality of grooves such as three.
[0034]
FIG. 4 shows a joining tool (10B) according to a second embodiment of the present invention (invention 1). In the figure, the same reference numerals are assigned to the same elements as those of the joining tool (10A) of the first embodiment.
[0035]
In this joining tool (10B), the end surface (12) of the tip of the rotor (11) has three annular grooves with different radii around the center of rotation of the end surface (12). (16), (16), and (16) are provided concentrically so as to surround the probe (13). Desirable width w2, average depth h2 and pitch p2 in the groove (16) are the same as those in the groove (15) of the joining tool (10A) of the first embodiment.
[0036]
Other configurations of the joining tool (10B) are the same as those of the joining tool (10A) of the first embodiment. Also, the joining method for joining using this joining tool (10B) is the same as the joining method shown in the first embodiment, and redundant description is omitted.
[0037]
According to this joining tool (10B), by receiving the pressure contact force from the tip of the rotor (11), the meat of both joining members (1a) (1b) becomes the end face of the tip of the rotor (11) ( 12) Housed and held inside. Furthermore, when the meat bites into the groove (16), the meat is prevented from being discharged more strongly, so that a butt joint having a good joined state can be obtained.
[0038]
In the present invention, the number of the annular grooves (16) may be one, or a plurality of three or the like.
[0039]
FIG. 5 shows a welding tool (10C) according to a third embodiment of the present invention (Claim 2). In the figure, the same reference numerals are assigned to the same elements as those of the joining tool (10A) of the first embodiment.
[0040]
In this joining tool (10C), the groove (15) is not provided on the end surface (12) of the tip of the rotor (11), and the tip of the rotor (11) A stepped portion having an L-shaped section that gradually approaches the probe (13) side as it goes to the side is formed over the entire circumference around the rotation axis (Q) of the rotor (11). Has been. In FIG. 5B, (17) and (17) indicate shoulder portions of the stepped portion.
[0041]
Other configurations of the joining tool (10C) are the same as those of the joining tool (10A) of the first embodiment, and a joining method for joining using the joining tool (10C) is also the first embodiment. This is the same as the joining method shown in the form, and redundant description is omitted.
[0042]
According to this joining tool (10C), since the two-stepped portion is formed on the outer peripheral surface of the tip of the rotor (11), the tip of the rotor (11) is attached at the time of joining. The shoulders (17) and (17) of the two stepped portions can be pressed against the surfaces of the two joining members (1a) and (1b) by press-contacting the surfaces of both joining members (1a) and (1b). As a result, the outer peripheral surface of the tip of the rotor (11) can be strongly adhered to the surfaces of the joint members (1a) (1b). As a result, it becomes difficult for the meat of both the joining members (1a) and (1b) accommodated and held inside the end face (12) to be discharged, so that a butt joint having a good joined state can be obtained.
[0043]
In this joining tool (10C), it is desirable that each stepped portion is set to have a step s within a range of 0.3 to 1 mm in that the above-described operation can be reliably achieved.
[0044]
In the present invention, the number of steps of the stepped portion may be one step or may be a plurality of steps such as three steps.
[0045]
The first to third embodiments of the present invention have been described above. However, the present invention is not limited to these embodiments, and various setting changes can be made.
[0046]
For example, the end surface (12) of the tip end portion of the rotor (11) of the joining tool may be formed as a concave surface having a circular arc shape that is recessed from the outer peripheral edge toward the rotation center portion side of the end surface (12). good.
[0047]
Further, in the joining tool, a stepped portion is formed on the outer peripheral surface of the front end portion of the rotor (11), and the spiral groove (15) or the end surface (12) of the front end portion of the rotor (11) is formed. An annular groove (16) may be provided.
[0048]
For the joining operation, both joining members are fixed so that the position of the tip of the rotor (11) of the joining tool is fixed and the abutting part (3) sequentially passes through the tip of the rotor (11). Bonding may be performed by moving (1a) and (1b).
[0049]
【Example】
Next, specific examples of the present invention will be described.
[0050]
<Example 1>
Two joining members (material: A6063-T5, dimensions: length 200 mm × width 100 mm × thickness 4 mm) made of a flat aluminum alloy were prepared. And the edge part of the width direction of one joining member and the edge part of the width direction of the other joining member were faced | matched in the aspect with which the surfaces continued in a flush manner. And the butt | matching part of both joining members was joined over the full length according to the joining method of the said 1st Embodiment using the joining tool (10A) of the said 1st Embodiment shown by FIGS. 1-3. Here, in a state where the rotation axis Q of the rotor is made to coincide with the surface normal T at the probe insertion position of both joint members, that is, the inclination of the rotor rotation axis Q with respect to the normal T toward the rear side in the joining direction. Bonding was performed with the angle θ set to 0 °.
[0051]
In the joining tool (10A) used in this joining, the probe (13) is formed in the shape of a shaft of an M5 screw, and the outer diameter of the tip of the rotor (11) is 15 mm. The length of the probe (13) is 4 mm. The dimensions of the groove (15) of the joining tool (10A) and the joining conditions applied at the time of joining are as follows.
[0052]
[Groove dimensions of welding tool]
・ Groove width w1… 1mm
・ Average depth h1 of groove: 1mm
・ Groove pitch p1 ... 1mm
[Bonding conditions]
・ Rotor speed: 1000rpm
-Joining speed: 600 mm / min
<Example 2>
The butted portions of both joining members were joined over the entire length using the joining tool (10B) of the second embodiment shown in FIG. The dimensions of the groove of the joining tool (10B) used in this joining and the joining conditions applied in this joining are as follows. The dimensions and joining conditions of other joining tools are the same as those in the first embodiment.
[0053]
[Groove dimensions of welding tool]
・ Groove width w2… 1mm
・ Average depth of groove h2… 1mm
・ Groove pitch p2… 1mm
<Example 3>
The butted portions of both joining members were joined over the entire length using the joining tool (10C) of the third embodiment shown in FIG. The dimensions of the stepped portion of the joining tool (10C) used during this joining and the joining conditions applied during this joining are as follows. The dimensions and joining conditions of other joining tools are the same as those in the first embodiment.
[0054]
[Dimensions of stepped parts of welding tool]
・ Step s of stepped part ... 0.5mm
<Comparative Example 1>
The butted portions of both joining members were joined over the entire length using the joining tool (110A) shown in FIG. Other bonding conditions are the same as those in the first embodiment.
[0055]
<Comparative example 2>
The butted portions of both joining members were joined over the entire length using the joining tool (110B) shown in FIG. Other bonding conditions are the same as those in the first embodiment.
[0056]
<Comparative Example 3>
The butted portions of both joining members were joined over the entire length using the joining tool (110B) shown in FIG. Here, joining was performed by setting the inclination angle θ of the rotation axis of the rotor with respect to the normal T to the rear side in the joining direction to 3 °. Other bonding conditions are the same as those in the first embodiment.
[0057]
Regarding the butt joints obtained in Examples 1 to 3 and Comparative Examples 1 to 3, the surface state of the joint was examined with the naked eye, and the presence or absence of internal defects in the joint was examined by an X-ray test. The results are shown in Table 1.
[0058]
[Table 1]

[0059]
In Table 1, in the column of “Surface condition of bonded part”, “X” indicates that the surface condition of the bonded part is poor. On the other hand, Δ, ○, and ◎ indicate that the surface state of the joint is good and that the surface state is good in this order.
[0060]
As shown in Table 1, in each of Examples 1 to 3, the surface state of the joint is good, and internal defects such as cavities are not generated in the joint, and the thickness of the joint is further increased. As a result, it was found that a good joint could be formed without inclining the rotation axis of the rotor to the rear side in the joining direction during joining. In particular, in Example 1, it was confirmed that it was possible to form a very good joint portion in the surface state, and thus it was possible to obtain an extremely high quality butt joint.
[0061]
On the other hand, in Comparative Examples 1 and 2, it was found that an internal defect such as a cavity portion occurred in the joint portion, and a good joint portion could not be formed. Moreover, in the comparative example 1, it turned out that a burr | flash generate | occur | produces on the surface of a junction part and a surface state becomes defective.
[0062]
【The invention's effect】
As described above, in the joining tool according to the first aspect of the present invention, the end surface of the tip portion of the rotor is formed as a concave surface that is recessed from the outer peripheral edge toward the rotation center side of the end surface. Since the probe protrudes from the center of rotation and the end surface is provided with a spiral or annular groove in a manner surrounding the probe, according to this joining tool, at the time of joining, the rotor Because the meat in the softened portion of the joining member softened by frictional heat can be accommodated and held inside the end face of the tip portion of the metal, and further, the accommodated meat can be bitten into the groove. , The meat can be held firmly, and the discharge of the meat can be suppressed. Therefore, according to this joining tool, it is possible to form a good joined portion without joining the rotation axis of the rotor to the rear side in the joining direction at the time of joining. In particular, when the groove is spiral, the meat can be held more firmly. Therefore, it becomes possible to further suppress the meat discharge and to form a better joint.
[0063]
In the joining tool according to the invention of claim 2, the end face of the tip of the rotor is formed as a concave surface that is recessed from the outer peripheral edge toward the rotation center of the end face. In addition, since the probe protrudes and the outer peripheral surface of the tip of the rotor is formed with a stepped portion that gradually approaches the probe as it advances toward the tip, according to this joining tool, At the time of joining, by pressing the tip of the rotor against the surface of the joining member, the shoulder of the stepped portion formed on the outer peripheral surface can be pressed against the surface of the joining member, and the tip of the rotor The outer peripheral surface of the part can be strongly adhered to the surface of the joining member. Therefore, the discharge of the meat of the joining member accommodated and held inside the end face can be suppressed. Therefore, according to this joining tool, it is possible to form a good joined portion without joining the rotation axis of the rotor to the rear side in the joining direction at the time of joining.
[0064]
Further, the friction stir welding method according to the invention of claim 3 is the friction stir welding method for joining using the joining tool according to claim 1 or 2, wherein the probe is inserted into the joining planned portion of the joining member. The tip of the rotor is pressed against the surface of the joining member, and in this state, the tip of the rotor is joined along the joining line without tilting the rotational axis of the rotor forward and backward in the joining direction. Since it is joined by moving it relative to the member, not only when the planned joining part extends in a straight line, but also when this is extended in a curved line, The tip portion can be easily relatively moved along the planned joining portion, and the joining operation can be easily performed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a state in the middle of joining when joining is performed using a joining tool according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view taken along line II-II in FIG.
3A is a bottom view of the welding tool of the first embodiment viewed from the tip side, and FIG. 3B is a cross-sectional view taken along line III-III in FIG.
4A is a bottom view of the joining tool of the second embodiment viewed from the tip side, and FIG. 4B is a cross-sectional view taken along the line IV-IV in FIG.
5A is a half sectional side view of a welding tool according to a third embodiment, and FIG. 5B is an enlarged sectional view of a portion A in FIG.
FIG. 6 is a perspective view showing a state in the middle of joining when joining is performed using a conventional joining tool.
7 is an enlarged sectional view taken along line VII-VII in FIG.
FIG. 8 is an enlarged cross-sectional view corresponding to FIG. 7, showing another conventional joining tool.
[Explanation of symbols]
1 ... Joining member
3 ... Butting part (part to be joined)
4 ... Junction
10A ... Joining tool of the first embodiment
10B ... Joining tool of the second embodiment
10C ... Joining tool of the third embodiment
11 ... Rotor
12… End face
13 ... Probe
15 ... spiral groove
16 ... annular groove
17… Shoulder shoulder

Claims

A large-diameter rotor (11) whose tip is pressed against the surface of the joining member (1), and a small-diameter probe (13) inserted into the joining portion (3) of the joining member (1). In the welding tool (10A) for friction stir welding provided,
The end surface (12) of the tip of the rotor (11) is formed as a concave surface that is recessed from the outer peripheral edge toward the rotation center portion of the end surface (12),
A probe (13) protrudes from the center of rotation of the end face (12),
The end surface (12) is provided with a spiral groove (15) in a manner surrounding the probe (13),
A joining tool for friction stir welding, characterized in that a stepped portion is formed on the outer peripheral surface of the tip of the rotor (11) stepwise toward the probe as it advances toward the tip.

The welding tool for friction stir welding according to claim 1, wherein the step (s) of the stepped portion is set within a range of 0.3 to 1 mm.

A large-diameter rotor (11) whose tip is pressed against the surface of the joining member (1), and a small-diameter probe (13) inserted into the joining portion (3) of the joining member (1). In the welding tool (10B) for friction stir welding provided,
The end surface (12) of the tip of the rotor (11) is formed as a concave surface that is recessed from the outer peripheral edge toward the rotation center portion of the end surface (12),
A probe (13) protrudes from the center of rotation of the end face (12),
An annular groove (16) is provided on the end face (12) in a manner surrounding the probe (13).
A joining tool for friction stir welding, characterized in that a stepped portion is formed on the outer peripheral surface of the tip of the rotor (11) stepwise toward the probe as it advances toward the tip.

The joining tool for friction stir welding according to claim 3, wherein the step (s) of the stepped portion is set within a range of 0.3 to 1 mm.

A large-diameter rotor (11) whose tip is pressed against the surface of the joining member (1), and a small-diameter probe (13) inserted into the joining portion (3) of the joining member (1). In the welding tool (10C) for friction stir welding provided,
The end surface (12) of the tip of the rotor (11) is formed as a concave surface that is recessed from the outer peripheral edge toward the rotation center portion of the end surface (12),
A probe (13) protrudes from the center of rotation of the end face (12),
A joining tool for friction stir welding, characterized in that a stepped portion is formed on the outer peripheral surface of the tip of the rotor (11) stepwise toward the probe as it advances toward the tip.

A friction stir welding method for joining using the joining tool according to claim 1,
The rotating probe (13) is inserted into the joining portion (3) of the joining member (1), the frictional heat generated by the rotation of the probe (13), and the rotating rotor (11) The meat in the softened part of the joining member (1) softened by the frictional heat generated by sliding between the end face (12) of the tip part and the surfaces of both joining members (1a) (1b) becomes the rotor (11 ) Of the joining member (1) so that the tip of the rotor (11) is accommodated and held in the end surface (12) of the tip of the rotor (11) by receiving the pressure contact force from the tip of the joint (1). In this state, the front end of the rotor (11) is not tilted to the front side and the rear side in the joining direction, and the tip of the rotor (11) is joined to the part to be joined (3). The friction stir welding method is characterized in that the joining is performed by moving relative to the joining member (1) along.

A friction stir welding method for joining using the joining tool according to claim 1 or 2,
The rotor (11) and the probe in the direction (R) in which the spiral groove (15) rotates around the probe (13) away from the probe (13) when viewed from the tip side of the rotor (11) (13) rotate together,
The rotating probe (13) is inserted into the joining portion (3) of the joining member (1), the frictional heat generated by the rotation of the probe (13), and the rotating rotor (11) The meat in the softened part of the joining member (1) softened by the frictional heat generated by sliding between the end face (12) of the tip part and the surfaces of both joining members (1a) (1b) becomes the rotor (11 ) Of the joining member (1) so that the tip of the rotor (11) is accommodated and held in the end surface (12) of the tip of the rotor (11) by receiving the pressure contact force from the tip of the joint (1). In this state, the front end of the rotor (11) is not tilted to the front side and the rear side in the joining direction, and the tip of the rotor (11) is joined to the part to be joined (3). The friction stir welding method is characterized in that the joining is performed by moving relative to the joining member (1) along.

A friction stir welding method for joining using a welding tool for friction stir welding,
The joining tool includes a large-diameter rotor (11) whose tip is pressed against the surface of the joining member (1), and a small-diameter probe (3) inserted into a joining scheduled portion (3) of the joining member (1). 13)
The end surface (12) of the tip of the rotor (11) is formed in a concave surface that is recessed from the outer peripheral edge toward the rotation center portion of the end surface (12),
A probe (13) protrudes from the center of rotation of the end face (12),
The end surface (12) is provided with a spiral groove (15) in a manner surrounding the probe (13),
The rotating probe (13) of the bonding tool is inserted into the bonding scheduled portion (3) of the bonding member (1), and frictional heat generated by the rotation of the probe (13) and the rotating rotor are rotated. The meat in the softened portion of the joining member (1) softened by frictional heat generated by sliding between the end surface (12) of the tip of (11) and the surfaces of both joining members (1a) and (1b), The tip of the rotor (11) is joined to the end face (12) of the tip of the rotor (11) by receiving a pressure contact force from the tip of the rotor (11). In pressure contact with the surface of (1), in this state, the tip of the rotor (11) is to be joined without tilting the rotational axis (Q) of the rotor (11) forward and backward in the joining direction. It is a friction stir welding method for joining by moving relative to the joining member (1) along (3) ,
In addition, when viewed from the front end side of the rotor (11), the spiral groove (15) rotates in the direction (R) rotating around the probe (13) away from the probe (13). And a friction stir welding method, wherein the probe (13) is integrally rotated to perform the joining.