JP2005000921A

JP2005000921A - Welding torch and automatic welding equipment

Info

Publication number: JP2005000921A
Application number: JP2003163919A
Authority: JP
Inventors: Yoshio Okayama; 良雄岡山
Original assignee: Futaba Industrial Co Ltd
Current assignee: Futaba Industrial Co Ltd
Priority date: 2003-06-09
Filing date: 2003-06-09
Publication date: 2005-01-06

Abstract

PROBLEM TO BE SOLVED: To provide a welding torch, in which a front end part is locked to a main body with sufficient force in a way that the front end part is locked easily at a front/rear directional position appropriate to the main body, and to provide automatic welding equipment provided with such a welding torch. SOLUTION: In a welding torch 100, when an outer cylindrical part 130 is arranged such that the rear end side part of an inside tapered face 132 is opposed to a taper hole 124, a spherical member 126 is held between the inside tapered face 132 and the tapered part of the taper hole 124. At that time, a part of the spherical member 126 is fitted into a recessed part 156 so that a front end part 150 is locked to a main body part 110. On the other hand, when the outer cylindrical part 130 is arranged such that the front end side part of the inside tapered face 132 is opposed to the taper hole 124, the spherical member 126 is released from the holding of the inside tapered face 132 and the tapered part of the taper hole 124, and consequently the front end part 150 may be extracted from the main body part 110. COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、交換可能な先端部を有する溶接トーチと、該溶接トーチを備えた自動溶接装置に関する。
【０００２】
【従来の技術】
従来より、アーク溶接やスポット溶接などに使用される溶接トーチには、本体部と、該本体部の前端側に着脱自在に取り付けられる先端部とを有するものがあることが知られている。このような溶接トーチにおいて、先端部は、溶接作業の繰り返しによって劣化した際等に取り替えられる。
【０００３】
本体部に対する先端部の取付構造としては、例えば、以下の特許文献１、２に記載のものが知られている。
特許文献１に記載の溶接トーチにおいては、チップを備えた先端部が筒状の本体部に挿入されるよう構成されている。この溶接トーチは、係止手段を備え、該係止手段は、先端部の外周面に設けられた凹溝と、本体部が備える筒状部分の内部に配置された球と、筒状部分に挿入される先端部の凹溝に向けて前記球を付勢するバネと、を備える。
【０００４】
この溶接トーチでは、先端部を本体部の筒状部分に挿入し、該先端部の凹溝にバネの付勢力により球を係止させることで、先端部が本体部に取り付けられる。また、この状態の本体部から先端部を引き抜く方向の負荷を本体部および先端部に作用させて、バネの弾発力に抗して球の凹溝への係止が解除されるようにすれば、先端部を取り外せる。
【０００５】
一方、特許文献２に記載の溶接トーチにおいては、電極ホルダーからなる先端部が本体部における筒状コレットに把持されるよう構成されている。この溶接トーチでは、本体部がトーチホルダーを備えており、筒状コレットは該トーチホルダーに対して前後方向に移動可能に配置されている。この溶接トーチでは、筒状コレットがトーチホルダーに対して前進した際には筒状コレットの内径が拡径されて先端部の把持が解除される一方、筒状コレットがトーチホルダーに対して後退した際には筒状コレットの内径が縮径されて先端部が把持されるようにされている。
【０００６】
【特許文献１】
特開昭５５−１１４４６５
【特許文献２】
特開昭６０−２０３３７１
【０００７】
【発明が解決しようとする課題】
しかし、上記特許文献１の構成では、バネの弾発力が付与された球によって先端部が本体部に係止されるに過ぎないため、先端部に衝撃等の外力が加わった際には、先端部に位置ずれが生じたり、先端部が本体部から抜け落ちる場合がある。
【０００８】
また、上記特許文献２の構成では、筒状コレットの内壁と先端部の外壁との摩擦力により先端部が本体部に対して十分な力で係止される。しかし、予め何らかの精巧な保持具等で先端部の前後方向の位置決めを行わないと、先端部の取替えの前後で本体部に対する先端部の前後位置がずれてしまう場合がある。
【０００９】
本発明は上記問題点を解決するためになされたものであり、その目的は、先端部を十分な力で本体部に係止できると共に、その係止の際には先端部を本体部に対して容易に適切な前後方向位置に係止できる溶接トーチと、このような溶接トーチを備えた自動溶接装置とを提供することである。
【００１０】
【課題を解決するための手段及び発明の効果】
かかる目的を達成するため、本発明の溶接トーチは、本体部と、該本体部の前端側に着脱自在に取り付けられる先端部とを有する。
この溶接トーチでは、先端部の外周面に凹部が設けられている。また、本体部は、先端部を挿入するための筒状部と、筒状部を取り囲み、筒状部に対して前後方向に移動可能に配置された外筒状部と、を備える。
【００１１】
また、筒状部は、細径側を内側にして当該筒状部をなす部材を貫通するテーパ孔を有し、該テーパ孔内には球状部材が配置され、外筒状部の内壁面には、前端側に向かって内径が拡径された内側テーパ面が設けられている。
この溶接トーチでは、外筒状部の筒状部に対する前後方向位置を変えることで、本体部に先端部を係止させたり、本体部による先端部の係止を解除させたりすることができる。
【００１２】
具体的には、この溶接トーチでは、先端部が筒状部に挿入され、内側テーパ面の後端側の部分がテーパ孔と対向するよう外筒状部が配置された際には、球状部材の一部がテーパ孔を介して筒状部の内側に突出して凹部に嵌め込まれ、この状態で球状部材が内側テーパ面とテーパ孔のテーパ部分とによって挟持されるようにされている。
【００１３】
また、この溶接トーチでは、内側テーパ面の前端側の部分がテーパ孔と対向するよう外筒状部が配置された際には、内側テーパ面とテーパ孔のテーパ部分とによる球状部材の係止が解除され、先端部の筒状部からの引き抜きが可能になるよう構成されている。
【００１４】
本発明の溶接トーチでは、球状部材の一部が凹部に嵌め込まれることにより、先端部が本体部に係止される。
そして、本発明では、凹部に嵌め込まれる球状部材にて先端部の係止を行う際に、球状部材が内側テーパ面とテーパ孔のテーパ部分とによって挟持されるので、球状部材をバネの弾発力によって付勢して先端部を係止する場合に比べ、先端部は十分な力で本体部に係止される。
【００１５】
また、先端部の凹部に球状部材の一部を嵌め込むことにより、先端部の本体部に対する前後方向位置を球状部材が凹部に嵌め込まれる位置に対応した適切な位置に容易に設定できる。
本発明の溶接トーチにおいては、筒状部の内部に配置され、先端部の後端側を当接させることで先端部の粗位置決めを行うための当接部を本体部が備えていることが好ましい。
【００１６】
この場合は、例えば、先端部の後端側を当接部に当接させた際に、先端部の凹部がテーパ孔と対向するよう構成することが望ましい。このようにすれば、テーパ孔から突出した球状部材の一部を容易に凹部に嵌め込ませることができる。
また、先端部の凹部は、細径側を内側とされたテーパ状凹部であることが好ましい。
【００１７】
このようにすれば、テーパ孔から突出した球状部材の一部が凹部に嵌め込まれ易くなる。つまり、例えば、筒状部に挿入された先端部における凹部の位置がテーパ孔と対向する適切な位置から若干ずれていたとしても、テーパ孔から突出した球状部材の一部が凹部に嵌め込まれていく際に、球状部材が凹部のテーパ部分に当接する。そして、球状部材が凹部のテーパ部分に沿って押し込まれていくにつれて、球状部材の凹部に対する適切な位置での嵌め込みが可能となるよう、球状部材に対する凹部の位置はずらされていき、球状部材は適切に凹部に嵌め込まれることになる。
【００１８】
本発明の溶接トーチにおいては、凹部に対する球状部材の嵌め込みが容易になされるよう、先端部の凹部が、先端部の外周面において周方向に延びる環状の凹部であってもよい。
また、本発明では、本体部の筒状部がテーパ孔を複数有し、それぞれのテーパ孔内には球状部材が配置されていてもよい。この場合、先端部が筒状部に挿入され、内側テーパ面の後端側の部分が複数の前記テーパ孔と対向するよう外筒状部が配置された際に、複数の前記テーパ孔を介して筒状部の内側に突出した複数の球状部材の一部が先端部の凹部に嵌め込まれるよう、凹部は構成されていることが好ましい。
【００１９】
一方、本体部は、外筒状部を前方に付勢することで、内側テーパ面の後端側の部分をテーパ孔と対向させ、球状部材の一部がテーパ孔を介して筒状部の内側に突出した状態で、球状部材を内側テーパ面とテーパ孔のテーパ部分とによって係止させる付勢手段を備えていることが好ましい。
【００２０】
このようにすれば、付勢手段の付勢力によって、球状部材が内側テーパ面とテーパ孔のテーパ部分とに挟持され、球状部材の一部が凹部に嵌め込まれた状態が安定的に維持される。よって、先端部が本体部に一層安定して保持される。
そして、このように付勢手段が設けられた場合においては、本体部が、付勢手段による付勢に抗して外筒状部を後方に移動させて、内側テーパ面の前端側の部分をテーパ孔と対向させ、内側テーパ面とテーパ孔のテーパ部分とによる球状部材の係止を解除して、先端部の筒状部からの引き抜きを可能にするためのロック解除手段を備えているとよい。
【００２１】
このようにすれば、ロック解除手段を機能させることで、先端部が本体部に安定的に保持された状態、或いは、先端部を本体部から取り外せる状態に設定可能となる。
ここで、付勢手段は、外筒状部の内壁に取り付けられる第１支持部と、第１支持部に前端が配置され、外筒状部の内壁と筒状部の外壁との間の箇所で前後方向に延在して、外筒状部を前方に移動させる付勢力を外筒状部に付与する付勢部材と、本体部の部分に設けられ、付勢部材の後端が配置される第２支持部と、を備えたものであってもよい。
【００２２】
また、付勢手段は、外筒状部の内壁に取り付けられ、筒状部の外壁に対して気密状態となるよう配置される第１支持部と、第１支持部の後端に前端が配置され、外筒状部の内壁と筒状部の外壁との間の箇所で前後方向に延在して、外筒状部を前方に移動させる付勢力を外筒状部に付与する付勢部材と、本体部の部分に設けられ、付勢部材の後端が配置される第２支持部と、を備えたものであってもよい。
【００２３】
この場合、ロック解除手段は、第１支持部と、第１支持部よりも前方の箇所で、外筒状部の内壁と筒状部の外壁との間に気密状態を付与する気密付与部と、第１支持部と気密付与部との間における外筒状部の内壁と筒状部の外壁との間の領域に画定される空隙部と、予め定められた流体の空隙部に対する供給や該流体の空隙部からの排出を行うため空隙部に接続された流体供給路と、を備えたものとして構成してもよい。
【００２４】
このようにすれば、第１支持部を付勢手段とロック解除手段との両方の構成要素として機能させることができ、部品点数を削減できる。
なお、本発明の溶接トーチにおいては、先端部が、軸方向の湾曲部分を有していてもよい。例えば、先端部が、予め定められた部分に予め定められた角度だけ曲げられることで軸方向が変化された湾曲部分を有していれば、全長に亘って直線状の先端部を用いたのでは溶接できない箇所に対する溶接が可能になる場合がある。
【００２５】
本発明の溶接トーチの用途は特定のものに限定されないが、例えば、アーク溶接やスポット溶接用のものであってもよい。
本発明の溶接トーチがアーク溶接用のものである場合、先端部は、溶接ワイヤを送出可能に保持するチップと、該チップを取り囲むノズルと、を備えたものとするとよい。
【００２６】
また、本発明においては、先端部が筒状部に挿入され、内側テーパ面の後端側の部分をテーパ孔と対向させて、球状部材の一部がテーパ孔を介して筒状部の内側に突出して凹部に嵌め込まれ、この状態で球状部材が内側テーパ面とテーパ孔のテーパ部分とによって係止された際に、筒状部、球状部材、及び先端部が相互に電気的に導通状態となり得るよう構成されているとよい。
【００２７】
このようにすれば、例えば、筒状部に通電を行うだけで先端部に対する通電が可能となり、溶接が可能となるという効果が得られる。
一方、本発明の自動溶接装置は、上述の溶接トーチと、該溶接トーチの制御を行う制御手段と、を備えている。この自動溶接装置によれば、上述の溶接トーチに関する効果と同様の効果が得られる。
【００２８】
本発明の自動溶接装置には、少なくとも１つの交換用の先端部が配置される先端部保持部が設けられ、当該自動溶接装置の制御手段は、溶接トーチの先端部の交換制御を行う交換手段を有しているとよい。
この場合、交換手段は、下記のように、解除位置設定手段と、引抜手段と、挿入手段と、固定位置設定手段とを有しているものとして構成すれば、先端部の交換作業自体が人手を介さずに自動で実行可能になる。
【００２９】
ここで、解除位置設定手段は、内側テーパ面の前端側の部分がテーパ孔と対向するよう外筒状部の位置設定を行い、内側テーパ面とテーパ孔のテーパ部分とによる球状部材の係止を解除して、先端部の筒状部からの引き抜きを可能にする。
引抜手段は、解除位置設定手段による外筒状部の位置設定の後に、筒状部に挿入されていた先端部を引き抜き、挿入手段は、該引抜手段による先端部の引き抜きの後、先端部保持部に配置された交換用の先端部を筒状部に挿入する。
【００３０】
また、固定位置設定手段は、挿入手段による交換用の先端部の挿入の後、内側テーパ面の後端側の部分がテーパ孔と対向するよう外筒状部の位置設定を行い、球状部材を内側テーパ面とテーパ孔のテーパ部分とによって係止して、球状部材の一部がテーパ孔を介して筒状部の内側に突出して凹部に嵌め込まれるようにする。
【００３１】
本発明の自動溶接装置における溶接トーチがアーク溶接用のものである場合、交換手段は、チップから外部に突出した溶接ワイヤの前端部を切断する切断手段と、前端部が切断された溶接ワイヤを後方に引き込み、筒状部に挿入された先端部内から溶接ワイヤを排除するワイヤ引込手段と、を備えたものとするとよい。
【００３２】
この場合、上述の解除位置設定手段は、ワイヤ引込手段による溶接ワイヤの引き込みの後に、動作するよう構成するとよい。
このように溶接ワイヤを引き込んでおけば、溶接ワイヤの位置を精密に考慮せずに、挿入手段によって、交換用の先端部の筒状部への挿入を実行しても問題が生じない。
【００３３】
つまり、例えば、上述のような溶接ワイヤの引き込みがなされず、先端部の配置箇所に溶接ワイヤが残っている状態で、挿入手段が、交換用の先端部の挿入を行う場合には、交換用の先端部に溶接ワイヤを挿入させながら、交換用の先端部を筒状部に挿入できるよう、交換用の先端部の軸心位置を精密に制御する必要がある。
【００３４】
一方、上記のように溶接ワイヤの引き込みがなされる場合には、交換用の先端部を筒状部に挿入できる程度に、交換用の先端部の軸心位置を調整すればよい。
そして、このように溶接ワイヤの引き込みがなされる場合には、固定位置設定手段による外筒状部の位置設定の後に、筒状部に挿入された先端部内に溶接ワイヤを通し、該ワイヤの前端部を前記チップから外部に突出させるワイヤ送出手段を備えるとよい。このようにすることで、交換用の先端部を用いたアーク溶接が実行可能となる。
【００３５】
なお、ワイヤ送出手段によって先端部内に溶接ワイヤが通される工程が適切に実行されるよう溶接トーチを構成することが望ましい。
具体的には、固定位置設定手段による外筒状部の位置設定の際には、凹部に嵌め込まれる球状部材により、交換用の先端部の軸心が溶接ワイヤの挿入動作が可能な位置に位置決めされるよう、溶接トーチを構成することが望ましい。
【００３６】
また、更に、ワイヤ送出手段によってチップの外部に突出させられた溶接ワイヤの突出長さを調整するワイヤ長調整手段を備えていてもよい。
ワイヤ長調整手段は、例えば、チップの外部に突出した溶接ワイヤの前端部を予め定められた箇所で切断することにより、溶接ワイヤの突出長さを調整するものであってもよい。
【００３７】
一方、本発明の自動溶接装置では、更に、制御手段が、筒状部に現在挿入され取り付けられている先端部につき、予め定められた交換時期に至ったか否かを判定する判定手段を備え、該判定手段にて先端部の交換時期に至ったと判定された際に、交換手段による先端部の交換制御が開始されるよう構成してもよい。
【００３８】
このようにすれば、先端部の交換時期が到来しているか否かの判断、及び先端部の交換作業自体という一連の作業全体を人手を介さずに自動で実行可能になる。
また、先端部が筒状部に挿入され、内側テーパ面の後端側の部分を前記テーパ孔と対向させて、球状部材の一部がテーパ孔を介して筒状部の内側に突出して凹部に嵌め込まれ、この状態で球状部材が内側テーパ面とテーパ孔のテーパ部分とによって係止された際に、筒状部、球状部材、及び先端部が相互に電気的に導通状態となり得るよう、溶接トーチが構成されている場合、制御手段は、筒状部に通電を行うことで先端部に対する通電を行うようにされているとよい。
【００３９】
このようにすれば、例えば、筒状部から球状部材を経て先端部に至る上述の電気的経路の他に先端部に至る特別な電気的経路を設けなくても、先端部を用いた溶接が可能となり、溶接トーチの構成が簡略化されるという効果が得られる。
【００４０】
【発明の実施の形態】
以下に、本発明の好適な実施形態を図面に基づいて説明する。
図１は、本実施形態の自動溶接装置１の構成を機能ブロックで示した機能ブロック図、図２は、自動溶接装置１中の溶接トーチ１００の構成を示した断面図である。
【００４１】
本実施形態の自動溶接装置１は、アーク溶接用の装置である。この自動溶接装置１は、図１に示すように、溶接部１０と、エア供給部２０と、溶接ワイヤ送り部３０と、溶接ワイヤ切断部４０と、これらの部分１０，２０，３０，４０の制御を行う制御部５０と、先端部保持部６０と、先端部係合プレート７０と、を備えている。
【００４２】
溶接部１０は、溶接トーチ１００と、該溶接トーチ１００に取り付けられ、制御部５０からの制御信号に基づき該溶接トーチ１００を所定の溶接箇所に移動させて支持するアーム部１２と、を備えている。
エア供給部２０は、エアポンプ（図示省略）等からなり、制御部５０からの制御信号に基づき圧縮空気を圧送し、エア供給路１４２（後述）を介して溶接トーチ１００の空隙部１４０（後述）に圧縮空気を充填させる。
【００４３】
溶接ワイヤ送り部３０は、アーク溶接用として溶接トーチ１００に供給される溶接ワイヤが巻回されたリール（図示省略）や、制御部５０からの制御信号に基づき、該リールを回動させて溶接トーチ１００への溶接ワイヤの供給及び溶接トーチ１００からの溶接ワイヤの引き込みを行うためのモータ（図示省略）等からなる。
【００４４】
溶接ワイヤ切断部４０は、制御部５０からの制御信号に基づき溶接ワイヤの切断を行うエアニッパ４２（図４（ａ）参照）を備えている。
そして、制御部５０は、ＣＰＵ、メモリ等を備えた論理演算回路を中心として構成され、該論理演算回路は、メモリに記憶されたプログラム等に基づき、溶接部１０、エア供給部２０、溶接ワイヤ送り部３０及び溶接ワイヤ切断部４０との間で信号の入出力を行う。
【００４５】
また、先端部保持部６０は、溶接トーチ１００の構成要素である先端部１５０（後述）が交換用のものとして少なくとも１つ配置された部材として構成されている。
本実施形態では、先端部保持部６０は、上方に開口した複数の先端部保持孔６２を有するものとして構成されている（図４（ｄ）参照）。そして、複数の先端部保持孔６２のそれぞれには交換用の先端部１５０がそれぞれ配置される。
【００４６】
また、先端部係合プレート７０は、溶接トーチ１００の先端部１５０を交換のため引き抜く際に、当該先端部１５０を保持するための部材であり、先端部に係合させるための係合部７２を有している（図４（ｃ）参照）。
次に、図２を参照して、本実施形態の溶接トーチ１００の構成につき説明する。
【００４７】
溶接トーチ１００は、本体部１１０と、該本体部１１０の前端側に着脱自在に取り付けられる先端部１５０とを備える。
本体部１１０は、溶接ワイヤ３を挿通可能な貫通孔１１６を有するトーチ本体１１５と、該トーチ本体１１５を内部に装着させてなる筒状部１２０と、該筒状部１２０を取り囲み、該筒状部１２０に対して前方向Ｘ１または後方向Ｘ２に移動可能に配置された外筒状部１３０と、を備えている。
【００４８】
トーチ本体１１５は、筒状部１２０の内部の後方部分に嵌合されている。筒状部１２０の内部の前方部分は、先端部１５０の後端部分を挿入可能となるよう前方に開口した先端部挿入穴１２２とされている。
なお、トーチ本体１１５の前端面１１７は、先端部１５０の本体部１１０への装着時に先端部１５０の後端面１５２を当接させて先端部１５０の粗位置決めを行うための当接部としての機能を有している。
【００４９】
筒状部１２０は、その前方部分に、細径側を内側にして当該筒状部１２０をなす部材を貫通する複数のテーパ孔１２４を有している。そして、各テーパ孔１２４内には、球状部材１２６が配置されている。球状部材１２６は、少なくとも表面部分が導電性を有する材料で構成された部材であり、例えば、真鍮球や、表面に銀メッキを施された球状の部材として構成されている。
【００５０】
外筒状部１３０の前方部分の内壁面には、前端側に向かって内径が拡径された内側テーパ面１３２が設けられている。
図２に示すように外筒状部１３０が筒状部１２０に対して比較的前方Ｘ１に押し出され、内側テーパ面１３２の後端側の部分がテーパ孔１２４と対向するよう外筒状部１３０が配置されると、球状部材１２６が内側テーパ面１３２に押される。
【００５１】
そして、該球状部材１２６の一部がテーパ孔１２４を介して筒状部１２０の内側に突出し、この状態で、球状部材１２６は内側テーパ面１３２とテーパ孔１２４のテーパ部分とによって挟持される。
逆に、外筒状部１３０が筒状部１２０に対して比較的後方Ｘ２に押され、内側テーパ面１３２の前端側の部分がテーパ孔１２４と対向するよう外筒状部１３０が配置されると、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによる球状部材１２６の挟持が解除される。
【００５２】
一方、本実施形態では、外筒状部１３０の内壁に、周方向に延びる環状の第１支持部１３４が取り付けられている。第１支持部１３４は、外筒状部１３０の内壁に取り付けられた環状部材１３４ａと、密閉部材１３４ｂとを備える。
環状部材１３４ａは、筒状部１２０を取り囲むよう配置されており、筒状部１２０の外壁側を向いた内側の部分に環状の凹部を有している。そして、この凹部には、密閉部材１３４ｂが嵌め込まれている。密閉部材１３４ｂは、ゴム状樹脂（例えば、フッ素ゴム）等の弾性部材からなり、環状の形状を有している（例えば、Ｏリング等として構成されている）。密閉部材１３４ｂは筒状部１２０の外壁に対して気密状態となるよう配置されている。
【００５３】
第１支持部１３４の後端には、バネ状部材等として構成された付勢部材１３８の前端が配置されている。付勢部材１３８は、外筒状部１３０の内壁と筒状部１２０の外壁との間の箇所で前後方向に延在しており、その後端は、外筒状部１３０の後方におけるトーチ本体１１５の外壁部分に取り付けられた第２支持部１３９に配置されている。
【００５４】
外筒状部１３０は、付勢部材１３８の付勢力によって前方に付勢され、後述のエア圧力による付勢力が作用しない定常状態においては、図２に示すように、内側テーパ面１３２の後端側の部分とテーパ孔１２４とが対向する。このとき、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによって球状部材１２６は挟持され、球状部材１２６の一部がテーパ孔１２４を介して筒状部１２０の内側に突出した状態となる。
【００５５】
また、一方、第１支持部１３４よりも前方における外筒状部１３０の内壁と筒状部１２０の外壁との間の箇所には、気密付与部１２８が設けられている。
気密付与部１２８は、筒状部１２０の外壁に全周にわたって設けられた環状凹部１２８ａと、該環状凹部１２８ａに全周にわたって嵌め込まれた環状の密閉部材１２８ｂとを備える。密閉部材１２８ｂは、上述の密閉部材１３４ｂと同様に弾性部材からなり、該密閉部材１２８ｂが配置された箇所で、外筒状部１３０の内壁と筒状部１２０の外壁との間に気密状態を付与している。
【００５６】
本実施形態では、第１支持部１３４と気密付与部１２８との間における外筒状部１３０の内壁と筒状部１２０の外壁との間の領域に空隙部１４０が画定されている。空隙部１４０には、エア供給部２０につながったエア供給路１４２（流体供給路に相当）が接続されている。
【００５７】
エア供給部２０の働きにより、エア供給路１４２を介して空隙部１４０に圧縮空気が充填されると、そのエア圧力により、外筒状部１３０は、付勢部材１３８による付勢に抗して後方に移動される。
その際には、内側テーパ面１３２の前端側の部分がテーパ孔１２４と対向するよう外筒状部１３０が配置され、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによる球状部材１２６の挟持が解除される。
【００５８】
一方、先端部１５０は、溶接ワイヤ３を挿通可能な貫通孔１５４を有する先端部本体１５１と、該先端部本体１５１の前方に連設され、貫通孔１５４を通過した溶接ワイヤ３を接触状態で通過させる貫通孔１６２を有するチップ１６０と、該チップ１６０を取り囲むように設けられたノズル１６５と、を有する。
【００５９】
先端部本体１５１の後方部分１５１ａは、筒状部１２０の先端部挿入穴１２２に挿入されるよう構成されている。先端部本体１５１の外周面には、筒状部１２０のテーパ孔１２４に対応する箇所に、周方向に延びる環状の凹部１５６が設けられており、該凹部１５６は、細径側を内側とされたテーパ状凹部とされている。
【００６０】
本実施例では、空隙部１４０に圧縮空気を充填して外筒状部１３０を後方に移動させ、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによる球状部材１２６の挟持を解除させた状態で、先端部挿入穴１２２に後方部分１５１ａを挿入すると、球状部材１２６は、挿入されてきた後方部分１５１ａによって筒状部１２０の半径方向外側の方向（内側テーパ面１３２に近づく方向）に押し出される。
【００６１】
そして、先端部本体１５１の後端面１５２がトーチ本体１１５の前端面１１７に当接するまでは、球状部材１２６は、外周面１５１ｂに当接した状態となる。後端面１５２が前端面１１７に当接して、先端部１５０の粗位置決めがなされると、凹部１５６がテーパ孔１２４に対向する。そして、エア供給部２０から空隙部１４０への圧縮空気の供給が切られ、空隙部１４０に充填された圧縮空気がエア供給路１４２を介して排出されると、付勢部材１３８の付勢力により外筒状部１３０が前方に移動される。
【００６２】
このとき、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによって球状部材１２６は挟持される。そして、図２に示すように、球状部材１２６の一部は、テーパ孔１２４を介して筒状部１２０の内側に突出して凹部１５６に嵌め込まれ、先端部１５０は、本体部１１０に係止される。
【００６３】
本実施形態では、このように内側テーパ面１３２とテーパ孔１２４のテーパ部分とによって挟持された球状部材１２６で先端部１５０の係止を行う分だけ、バネの弾発力によって付勢された球状部材で先端部を本体部に係止する従来の場合に比べ、先端部１５０は十分な力で本体部１１０に係止される。
【００６４】
また、凹部１５６に球状部材１２６の一部が嵌め込まれることにより、先端部１５０の本体部１１０に対する前後方向位置が、球状部材１２６の凹部１５６への嵌め込み位置に対応した適切な位置に容易に設定される。
また、本実施形態では、上述のように、先端部１５０の凹部１５６が細径側を内側とされたテーパ状凹部である。よって、筒状部１２０に挿入された先端部１５０における凹部１５６の位置がテーパ孔１２４と対向する適切な位置から若干ずれていたとしても、両者の位置関係は球状部材１２６が凹部１５６に挿入されていくにつれて適切なものに補正される。
【００６５】
また、本実施形態では、凹部１５６は周方向に全周にわたって延びる環状のものとされている。よって、先端部１５０が前後方向を軸とするどのような回転方向位置にあっても、凹部１５６に対する球状部材１２６の嵌め込みは容易に実行できる。
【００６６】
なお、本実施形態では、先端部本体１５１の外周面の後端部分に、細径側を後端側としたテーパ面１５８を設けてある。よって、このようなテーパ面１５８がない場合に比べ、先端部本体１５１の後方部分１５１ａを筒状部１２０の先端部挿入穴１２２に挿入し易い。
【００６７】
また、本実施形態では、トーチ本体１１５、筒状部１２０、及び先端部１５０（少なくとも先端部本体１５１とチップ１６０）が導電性を有する材料で構成されている。
そして、上記のように内側テーパ面１３２とテーパ孔１２４のテーパ部分とによって球状部材１２６が挟持され、球状部材１２６の一部が凹部１５６に嵌め込まれた際には、トーチ本体１１５、筒状部１２０、球状部材１２６、及び先端部１５０は相互に接触した状態となり、これらは通電を行うことで相互に電気的に導通状態となりえるよう構成されている。
【００６８】
本実施形態では、制御部５０がトーチ本体１１５を介して筒状部１２０に通電を行えるよう構成されている。溶接時には、筒状部１２０に通電がなされることで、先端部１５０のチップ１６０を経て、チップ１６０に接触している溶接ワイヤ３に通電がなされ、アーク溶接が可能となる。
【００６９】
次に、制御部５０内のメモリに記憶されたプログラムに基づき、溶接実行時に制御部５０で繰り返し実行される制御処理につき、図３に示すフローチャートと、図４に示す制御処理実行時の溶接トーチの状態を示す説明図とを用いて説明する。
【００７０】
図３に示す如く、制御処理が開始されると、まず、Ｓ１１０（Ｓはステップを表す）にて、溶接処理を実行させる。この処理では、アーム部１２を駆動させて溶接トーチ１００を予め定められた溶接箇所に移動させると共に、筒状部１２０に通電を行うことで、チップ１６０に送出可能に保持された溶接ワイヤ３によるアーク溶接が実行される。
【００７１】
次に、Ｓ１２０では、チップ１６０の損耗等により先端部１５０を交換すべき時期に至ったか否かを判断する。本実施例では、同一の先端部１５０を用いてアーク溶接を行った距離等の溶接履歴を記憶しておき、それが所定の数値に達した時点（例えば、アーク溶接を行った距離が１００ｍに達した時点）を先端部１５０の交換時期として判断する。
【００７２】
Ｓ１２０で交換時期に達していないと判断されると（Ｓ１２０：ＮＯ）、Ｓ１１０に移行するが、交換時期に達したと判断されると（Ｓ１２０：ＹＥＳ）、続くＳ１３０に移行する。
Ｓ１３０では、アーム部１２を駆動させて溶接トーチ１００の先端部１５０から突出した溶接ワイヤ３を溶接ワイヤ切断部４０のエアニッパ４２近傍に移動させる。そして、該エアニッパ４２にて、溶接ワイヤ３の先端で塊状となった部分を含む該溶接ワイヤ３の前端部を切断させる（図４（ａ）参照）。
【００７３】
次に、Ｓ１４０では、溶接ワイヤ送り部３０のリールを回動させて、溶接トーチ１００内の溶接ワイヤ３を矢印ａで示す後方に引き込み、現在筒状部１２０に装着されている先端部１５０内から溶接ワイヤ３を排除する（図４（ｂ）参照）。
【００７４】
そして、続くＳ１５０では、エア供給部２０の動作により、空隙部１４０に圧縮空気を充填して、外筒状部１３０を矢印ｂで示す後方に移動させる。それにより、内側テーパ面１３２の前端側の部分がテーパ孔１２４と対向するようにして、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによる球状部材１２６の挟持を解除させる。
【００７５】
次に、Ｓ１６０では、アーム部１２により溶接トーチ１００を移動させ、先端部本体１５１の段部１５１ｃに先端部係合プレート７０の係合部７２を係合させる。そして、この状態で、アーム部１２により溶接トーチ１００を矢印ｃで示す後方に移動させることで、筒状部１２０に挿入されていた先端部１５０を引き抜く（図４（ｃ）参照）。
【００７６】
次に、Ｓ１７０では、アーム部１２を駆動させて、先端部保持部６０に配置された複数の先端部１５０のうちの１つを筒状部１２０の先端部挿入穴１２２に挿入させるよう筒状部１２０の位置設定を行う（図４（ｄ）参照）。
このときは、空隙部１４０に圧縮空気を充填した状態を保持して、外筒状部１３０を矢印ｂで示した後方に位置させ、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによる球状部材１２６の挟持が解除された状態としておく。
【００７７】
よって、この処理では、図４（ｄ）中に矢印ｄで示された前方に本体部１１０を移動させるだけで、先端部挿入穴１２２に対する先端部１５０の挿入が可能となる。
そして、Ｓ１８０では、空隙部１４０への圧縮空気の供給を切り、外筒状部１３０を図４（ｅ）中に矢印ｅで示された前方に移動させる。このとき、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによって球状部材１２６は挟持され、球状部材１２６の一部は凹部１５６に嵌め込まれる。それにより、先端部１５０は、本体部１１０に係止される。
【００７８】
続くＳ１９０では、溶接ワイヤ送り部３０のリールを回動させて、トーチ本体１１５内の溶接ワイヤ３を図４（ｅ）中に矢印ｆで示された前方に送り出す。そして、今回新たに筒状部１２０に装着された先端部１５０内に溶接ワイヤ３を通し、該溶接ワイヤ３の前端部をチップ１６０から外部に突出させる（図４（ｅ）参照）。
【００７９】
次に、Ｓ２００では、アーム部１２を駆動させて溶接トーチ１００の先端部１５０から突出した溶接ワイヤ３をエアニッパ４２近傍に移動させる。そして、該エアニッパ４２にて、溶接ワイヤ３の前端部を予め定められた箇所で切断させることで、チップ１６０から突出した溶接ワイヤ３の長さ調整を行う（図４（ｆ）参照）。
【００８０】
そして、Ｓ２００の処理が完了すると、再びＳ１１０に移行し、以後、Ｓ１１０〜Ｓ２００の処理を再度実行する。
本実施形態では、上記Ｓ１１０〜Ｓ２００の処理を繰り返し実行することで、溶接処理（Ｓ１１０）、先端部１５０の交換時期が到来しているか否かの判断（Ｓ１２０）、及び先端部１５０の交換作業自体（Ｓ１３０〜Ｓ２００）という一連の作業全体を人手を介さずに自動で実行可能になる。
【００８１】
なお、上記において、Ｓ１２０の処理は判定手段の動作に相当し、Ｓ１３０の処理は切断手段の動作に相当し、Ｓ１４０の処理はワイヤ引込手段の動作に相当し、Ｓ１５０の処理は解除位置設定手段の動作に相当する。また、Ｓ１６０の処理は引抜手段の動作に相当し、Ｓ１７０の処理は挿入手段の動作に相当し、Ｓ１８０の処理は固定位置設定手段の動作に相当し、Ｓ１９０の処理はワイヤ送出手段の動作に相当し、Ｓ２００の処理はワイヤ長調節手段の動作に相当する。
【００８２】
以上、本発明の一実施形態について説明したが、本発明は、上記実施形態に限定されるものではなく、種々の態様を採ることができる。
例えば、上記実施形態では、図２に示すように、溶接トーチ１００においては、先端部１５０が前後方向に延設された直線状の部材として構成されていたが、図５（ａ）、（ｂ）に示すように、先端部に関しては、軸方向の湾曲部分２０１を有する先端部１５０’として構成されていてもよい。
【００８３】
このようにすれば、全長にわたって直線状の先端部１５０を用いたのでは溶接できない箇所に対する溶接が可能になる場合がある。
なお、図５（ａ）、（ｂ）では、図２に示した溶接トーチ１００の場合と同様の構成を有する部分には溶接トーチ１００の場合と同様の符号を付し、これらについての説明は省略する。
【００８４】
図５（ａ）、（ｂ）に示した溶接トーチ１００’の場合は、本体部１１０’に装着された先端部１５０’が外力の作用等により筒状部１２０’に対して回転してしまい、チップ１６０の位置が不安定になってしまうことを防止する回り止め機構２００を有していてもよい。
【００８５】
例えば、回り止め機構２００は、筒状部１２０’の前端部に設けられた筒状部側係合部（例えば、嵌合凹部として構成される部分）と、先端部１５０’の前記筒状部側係合部に対応する箇所に設けられた先端部側係合部（例えば、前記嵌合凹部に嵌合される突出部として構成される部分）と、からなるものであってもよい。
【００８６】
この場合、先端部１５０’が筒状部１２０’に挿入され、先端部１５０’の後端面１５２がトーチ本体１１５の前端面１１７に当接した際に、筒状部側係合部と先端部側係合部とが係合し、それにより、先端部１５０’の筒状部１２０’に対する回転が防止されるよう構成されているとよい。
【００８７】
また、一方、筒状部１２０（１２０’）に挿入された先端部１５０（１５０’）が筒状部１２０（１２０’）内でがたつくことが好適に防止されるよう構成されていることが好ましい。
例えば、筒状部１２０（１２０’）の内壁と先端部１５０（１５０’）の筒状部１２０（１２０’）に挿入される部分との間に少なくとも１つの密封状態付与部２１０（例えば、図５（ａ）参照）を設けることで、このようながたつきを防止するようにするとよい。
【００８８】
密封状態付与部２１０は、図５（ａ）に示すように、筒状部１２０’の内壁の全周にわたって設けられた環状凹部２１０ａと、該環状凹部２１０ａに全周にわたって嵌め込まれた環状の密封部材２１０ｂとを備える。密封部材２１０ｂは、上述の密閉部材１２８ｂ，１３４ｂと同様に弾性部材からなり、先端部１５０’の部分に密着することで、先端部１５０’が筒状部１２０’内でがたつかないようにする。
【００８９】
なお、図５（ａ）のように密封状態付与部２１０を構成すると、その構成によっては、密封部材２１０ｂが環状凹部２１０ａから外れやすくなってしまう場合もある。そこで、そのような外れやすさを好適に防止するため、密封状態付与部は、図６に示すように、先端部１５０’の外壁に設けられたもの２２０であってもよい。この場合、密封状態付与部２２０は、先端部１５０’の筒状部１２０’に挿入される部分の外壁の全周にわたって設けられた環状凹部２２０ａと、該環状凹部２２０ａに全周にわたって嵌め込まれた環状の密封部材２２０ｂとを備える。密封部材２２０ｂは、上述の密封部材２１０ｂと同様に弾性部材からなり、筒状部１２０’の内壁に密着することで、先端部１５０’が筒状部１２０’内でがたつかないようにする。
【００９０】
また、上記実施形態では、自動溶接装置１がアーク溶接用の装置である旨の説明をしたが、交換可能な先端部を有する溶接トーチを備えたものであれば、他の種類の自動溶接装置であっても本発明を適用可能である。
例えば、スポット溶接用の自動溶接装置に本発明を適用することも当然可能であり、図７（ａ）〜（ｃ）は、スポット溶接用の溶接トーチ３００に本発明を適用した他の実施形態を示す断面図である。
【００９１】
溶接トーチ３００は、本体部３１０と、該本体部３１０の前端側に着脱自在に取り付けられる交換可能な先端部３５０とを備える。
図７（ａ）〜（ｃ）では、図２に示した溶接トーチ１００の場合と同様の構成を有する部分には溶接トーチ１００の場合と同様の符号を付してある。なお、図７（ａ）では、気密付与部１２８、第１支持部１３４、空隙部１４０、エア供給路１４２の図示を行っているが、図７（ｂ）、（ｃ）では、これらの図示を省略している。
【００９２】
この溶接トーチ３００を備えた自動溶接装置では、上記実施形態で説明した自動溶接装置１の場合と異なり、溶接ワイヤ３を用いない。よって、この自動溶接装置では、図１で示した構成のうち、溶接ワイヤ送り部３０や溶接ワイヤ切断部４０が省かれる。また、図３で示した各処理のうち、Ｓ１３０，Ｓ１４０，Ｓ１９０，Ｓ２００が省かれる。
【００９３】
この溶接トーチ３００を備えた自動溶接装置においても、図３で示したＳ１２０，Ｓ１５０〜Ｓ１８０に対応した処理を行うことにより、先端部３５０の交換が可能である。
つまり、まず、溶接処理を継続していく中で先端部３５０の交換時期が到来したと判断された際に（Ｓ１２０：ＹＥＳ，図７（ａ）参照）、外筒状部１３０を後方に移動させ、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによる球状部材１２６の挟持を解除させる（Ｓ１５０，図７（ｂ）参照）。
【００９４】
次いで、筒状部１２０に挿入されていた先端部３５０を引き抜く（Ｓ１６０，図７（ｃ）参照）。そして、交換用の先端部３５０を筒状部１２０に挿入した上（Ｓ１７０）、外筒状部１３０を前方に移動させ、内側テーパ面１３２とテーパ孔１２４のテーパ部分とによって球状部材１２６を挟持させる（Ｓ１８０）。このとき、球状部材１２６の一部は凹部１５６に嵌め込まれ、それにより、先端部３５０は、本体部３１０に係止される（図７（ａ）参照）。
【００９５】
なお、この自動溶接装置の場合、Ｓ１２０に対応した処理では、例えば、同一の先端部３５０を用いた溶接の回数（溶接打点数）等の溶接履歴を記憶しておき、それが所定の回数に達した時点（例えば、スポット溶接を行った回数が５００回に達した時点）を先端部３５０の交換時期として判断してもよい。
【００９６】
そして、このような溶接トーチ３００を備えた自動溶接装置の場合も、先端部３５０を十分な力で本体部３１０に係止できると共に、その係止の際には先端部３５０を本体部３１０に対して容易に適切な前後方向位置に係止できる等の上記実施形態と同様の効果が得られる。
【００９７】
なお、この自動溶接装置において、溶接トーチ３００内に溶接トーチ冷却用の冷却液を流す冷却液流路が設けられ、該冷却液に流動力を付与するポンプ等の流動力付与手段が設けられている場合は、上記のＳ１２０に対応した処理とＳ１５０に対応した処理との間に、冷却液の流動を止める処理を行ってもよい。そして、この場合は、上記のＳ１８０に対応した処理の後に、冷却液の流動を再開させる処理を行うとよい。
【図面の簡単な説明】
【図１】実施形態の自動溶接装置の構成を機能ブロックで示した機能ブロック図である。
【図２】実施形態の自動溶接装置中の溶接トーチの構成を示した断面図である。
【図３】実施形態の自動溶接装置の制御部が実行する制御処理を示したフローチャートである。
【図４】制御処理実行時の溶接トーチの状態を示す説明図である。
【図５】他の実施形態の溶接トーチの構成を示した断面図である。
【図６】他の実施形態の溶接トーチの構成を示した断面図である。
【図７】他の実施形態の溶接トーチの構成、及び該溶接トーチの先端部の交換時の状態を示した断面図である。
【符号の説明】
１…自動溶接装置、３…溶接ワイヤ、１０…溶接部、２０…エア供給部、３０…溶接ワイヤ送り部、４０…溶接ワイヤ切断部、５０…制御部、６０…先端部保持部、７０…先端部係合プレート、１００，１００’，３００…溶接トーチ、１１０，１１０’，３１０…本体部、１１５…トーチ本体、１１７…前端面、１２０，１２０’…筒状部、１２４…テーパ孔、１２６…球状部材、１２８…気密付与部、１３０…外筒状部、１３２…内側テーパ面、１３４…第１支持部、１３８…付勢部材、１３９…第２支持部、１４０…空隙部、１４２…エア供給路、１５０，１５０’，３５０…先端部、１５１…先端部本体、１５２…後端面、１５６…凹部、１６０…チップ、１６５…ノズル、２０１…湾曲部分[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a welding torch having a replaceable tip and an automatic welding apparatus including the welding torch.
[0002]
[Prior art]
Conventionally, it has been known that some welding torches used for arc welding, spot welding, and the like have a main body portion and a tip portion that is detachably attached to the front end side of the main body portion. In such a welding torch, the tip is replaced when it deteriorates due to repeated welding operations.
[0003]
For example, the following Patent Documents 1 and 2 are known as the attachment structure of the tip part with respect to the main body part.
The welding torch described in Patent Document 1 is configured such that a tip portion provided with a tip is inserted into a cylindrical main body portion. The welding torch includes locking means, and the locking means includes a concave groove provided on the outer peripheral surface of the distal end portion, a sphere disposed inside the cylindrical portion provided in the main body portion, and a cylindrical portion. And a spring that biases the sphere toward the concave groove of the inserted tip.
[0004]
In this welding torch, the distal end portion is attached to the main body portion by inserting the distal end portion into the cylindrical portion of the main body portion and locking the ball in the concave groove of the distal end portion by the biasing force of the spring. In addition, a load in the direction of pulling the tip portion out of the main body portion in this state is applied to the main body portion and the tip portion so that the lock on the concave groove of the sphere is released against the elastic force of the spring. The tip can be removed.
[0005]
On the other hand, the welding torch described in Patent Document 2 is configured such that the tip portion made of an electrode holder is held by a cylindrical collet in the main body portion. In this welding torch, the main body portion includes a torch holder, and the cylindrical collet is arranged so as to be movable in the front-rear direction with respect to the torch holder. In this welding torch, when the cylindrical collet moves forward with respect to the torch holder, the inner diameter of the cylindrical collet is expanded and the grip of the tip is released, while the cylindrical collet is retracted with respect to the torch holder. At this time, the inner diameter of the cylindrical collet is reduced to grip the tip.
[0006]
[Patent Document 1]
JP 55-114465 A
[Patent Document 2]
JP-A-60-203371
[0007]
[Problems to be solved by the invention]
However, in the configuration of Patent Document 1 described above, since the tip portion is merely locked to the main body portion by the sphere to which the elastic force of the spring is applied, when an external force such as an impact is applied to the tip portion, There may be a positional shift at the tip, or the tip may fall out of the main body.
[0008]
Moreover, in the structure of the said patent document 2, a front-end | tip part is latched with sufficient force with respect to a main-body part with the frictional force of the inner wall of a cylindrical collet, and the outer wall of a front-end | tip part. However, if the front-end portion is not positioned in the front-rear direction with some sophisticated holding tool or the like, the front-rear position of the front-end portion with respect to the main body portion may be shifted before and after replacement of the front-end portion.
[0009]
The present invention has been made in order to solve the above-described problems, and the purpose of the present invention is to lock the tip portion to the main body portion with a sufficient force, and to fix the tip portion to the main body portion at the time of locking. It is another object of the present invention to provide a welding torch that can be easily locked at an appropriate front-rear direction position and an automatic welding apparatus equipped with such a welding torch.
[0010]
[Means for Solving the Problems and Effects of the Invention]
In order to achieve this object, the welding torch of the present invention has a main body portion and a tip portion that is detachably attached to the front end side of the main body portion.
In this welding torch, a concave portion is provided on the outer peripheral surface of the tip portion. The main body portion includes a cylindrical portion for inserting the distal end portion, and an outer cylindrical portion that surrounds the cylindrical portion and is arranged to be movable in the front-rear direction with respect to the cylindrical portion.
[0011]
Further, the cylindrical portion has a tapered hole that penetrates a member forming the cylindrical portion with the narrow diameter side inward, and a spherical member is disposed in the tapered hole, and is formed on the inner wall surface of the outer cylindrical portion. Is provided with an inner tapered surface whose inner diameter is increased toward the front end side.
In this welding torch, the front end portion can be locked to the main body portion or the front end portion can be unlocked by the main body portion by changing the position of the outer cylindrical portion relative to the cylindrical portion.
[0012]
Specifically, in this welding torch, when the outer cylindrical portion is disposed so that the tip end portion is inserted into the cylindrical portion and the rear end side portion of the inner tapered surface faces the tapered hole, Part of this protrudes into the inside of the cylindrical portion through the tapered hole and is fitted into the concave portion, and in this state, the spherical member is sandwiched between the inner tapered surface and the tapered portion of the tapered hole.
[0013]
Further, in this welding torch, when the outer cylindrical portion is disposed so that the front end portion of the inner tapered surface faces the tapered hole, the spherical member is locked by the inner tapered surface and the tapered portion of the tapered hole. Is released, and the tip portion can be pulled out from the cylindrical portion.
[0014]
In the welding torch of the present invention, the tip portion is locked to the main body portion by fitting a part of the spherical member into the recess.
In the present invention, since the spherical member is held between the inner tapered surface and the tapered portion of the tapered hole when the tip portion is locked by the spherical member fitted in the concave portion, the spherical member is Compared with the case where the front end is locked by urging with force, the front end is locked to the main body with a sufficient force.
[0015]
Further, by fitting a part of the spherical member into the concave portion of the distal end portion, the front-rear direction position of the distal end portion with respect to the main body portion can be easily set to an appropriate position corresponding to the position where the spherical member is fitted into the concave portion.
In the welding torch of the present invention, the main body portion may be provided with a contact portion that is disposed inside the cylindrical portion and that performs rough positioning of the front end portion by contacting the rear end side of the front end portion. preferable.
[0016]
In this case, for example, when the rear end side of the front end portion is brought into contact with the contact portion, it is desirable that the concave portion of the front end portion is opposed to the tapered hole. In this way, a part of the spherical member protruding from the tapered hole can be easily fitted in the recess.
Moreover, it is preferable that the recessed part of a front-end | tip part is a taper-shaped recessed part which made the small diameter side the inner side.
[0017]
In this way, a part of the spherical member protruding from the tapered hole is easily fitted into the recess. That is, for example, even if the position of the concave portion at the tip portion inserted into the cylindrical portion is slightly deviated from an appropriate position facing the tapered hole, a part of the spherical member protruding from the tapered hole is fitted into the concave portion. When going, the spherical member comes into contact with the tapered portion of the recess. Then, as the spherical member is pushed along the tapered portion of the concave portion, the position of the concave portion with respect to the spherical member is shifted so that the spherical member can be fitted at an appropriate position with respect to the concave portion. It will fit into the recess properly.
[0018]
In the welding torch of the present invention, the concave portion of the tip portion may be an annular concave portion extending in the circumferential direction on the outer peripheral surface of the tip portion so that the spherical member can be easily fitted into the concave portion.
Moreover, in this invention, the cylindrical part of a main-body part has multiple taper holes, and the spherical member may be arrange | positioned in each taper hole. In this case, when the outer cylindrical portion is disposed so that the tip end portion is inserted into the cylindrical portion and the rear end side portion of the inner tapered surface faces the plurality of tapered holes, the plurality of tapered holes are interposed. It is preferable that the concave portion is configured so that a part of the plurality of spherical members protruding inside the cylindrical portion is fitted into the concave portion of the tip portion.
[0019]
On the other hand, the main body portion urges the outer cylindrical portion forward so that the rear end portion of the inner tapered surface faces the tapered hole, and a part of the spherical member passes through the tapered hole. It is preferable that a biasing means for locking the spherical member with the inner tapered surface and the tapered portion of the tapered hole in a state of protruding inward is provided.
[0020]
By doing so, the spherical member is sandwiched between the inner tapered surface and the tapered portion of the tapered hole by the urging force of the urging means, and a state in which a part of the spherical member is fitted in the recess is stably maintained. . Therefore, the tip portion is more stably held on the main body portion.
In the case where the urging means is provided in this way, the main body moves the outer cylindrical part backward against the urging by the urging means so that the front end portion of the inner tapered surface is moved. With a lock release means for releasing the locking of the spherical member by the inner taper surface and the taper portion of the taper hole so as to be opposed to the taper hole and allowing the tip portion to be pulled out from the cylindrical portion. Good.
[0021]
In this way, by causing the lock release means to function, it is possible to set the state in which the tip end portion is stably held by the main body portion or the state in which the tip end portion can be removed from the main body portion.
Here, the biasing means includes a first support part attached to the inner wall of the outer cylindrical part, a front end disposed on the first support part, and a location between the inner wall of the outer cylindrical part and the outer wall of the cylindrical part. And a biasing member that extends in the front-rear direction and applies a biasing force to the outer cylindrical portion to move the outer cylindrical portion forward, and a rear end of the biasing member is disposed on the body portion. The 2nd support part which may be provided.
[0022]
The urging means is attached to the inner wall of the outer cylindrical portion, and is arranged to be airtight with respect to the outer wall of the cylindrical portion, and the front end is arranged at the rear end of the first supporting portion. And a biasing member that extends in the front-rear direction at a location between the inner wall of the outer cylindrical portion and the outer wall of the cylindrical portion, and applies a biasing force that moves the outer cylindrical portion forward to the outer cylindrical portion. And a second support portion that is provided in the main body portion and on which the rear end of the urging member is disposed.
[0023]
In this case, the unlocking means includes a first support portion, and an airtight imparting portion that imparts an airtight state between the inner wall of the outer cylindrical portion and the outer wall of the cylindrical portion at a location in front of the first support portion. A gap defined in a region between the inner wall of the outer cylindrical portion and the outer wall of the cylindrical portion between the first support portion and the airtightness imparting portion, and supply of the predetermined fluid to the gap portion, You may comprise as a thing provided with the fluid supply path connected to the space | gap part in order to discharge | emit the fluid from the space | gap part.
[0024]
If it does in this way, a 1st support part can be functioned as both components of an urging means and a lock release means, and a number of parts can be reduced.
In the welding torch according to the present invention, the tip end portion may have an axially curved portion. For example, if the tip has a curved portion whose axial direction has been changed by being bent at a predetermined angle to a predetermined portion, the straight tip is used over the entire length. In some cases, it is possible to weld a portion that cannot be welded.
[0025]
Although the use of the welding torch of the present invention is not limited to a specific one, for example, it may be used for arc welding or spot welding.
In the case where the welding torch of the present invention is for arc welding, the tip portion may be provided with a tip that holds the welding wire so that the welding wire can be delivered and a nozzle that surrounds the tip.
[0026]
In the present invention, the tip portion is inserted into the cylindrical portion, the rear end portion of the inner tapered surface is opposed to the tapered hole, and a part of the spherical member is located inside the cylindrical portion via the tapered hole. When the spherical member is locked by the inner tapered surface and the tapered portion of the tapered hole in this state, the cylindrical portion, the spherical member, and the tip end portion are electrically connected to each other. It is good to be configured so that
[0027]
In this way, for example, it is possible to energize the tip portion simply by energizing the cylindrical portion, and the effect that welding is possible is obtained.
On the other hand, the automatic welding apparatus of the present invention includes the above-described welding torch and control means for controlling the welding torch. According to this automatic welding apparatus, an effect similar to the effect relating to the above-described welding torch can be obtained.
[0028]
The automatic welding apparatus of the present invention is provided with a tip end holding portion in which at least one replacement tip is disposed, and the control means of the automatic welding apparatus is an exchange means for performing exchange control of the tip of the welding torch. It is good to have.
In this case, if the replacement means is configured to have a release position setting means, a pulling means, an insertion means, and a fixed position setting means as described below, the tip replacement operation itself is manual. It can be executed automatically without going through.
[0029]
Here, the release position setting means sets the position of the outer cylindrical portion so that the front end portion of the inner tapered surface faces the tapered hole, and the spherical member is locked by the inner tapered surface and the tapered portion of the tapered hole. To release the tip from the cylindrical part.
The pulling means pulls out the tip part inserted into the cylindrical part after the position setting of the outer cylindrical part by the release position setting means, and the inserting means holds the tip part after pulling out the tip part by the pulling means. The tip part for replacement arranged in the part is inserted into the cylindrical part.
[0030]
The fixed position setting means sets the position of the outer cylindrical portion so that the rear end side portion of the inner tapered surface faces the tapered hole after the replacement tip portion is inserted by the insertion means, and the spherical member is The inner taper surface and the taper portion of the taper hole are used for locking so that a part of the spherical member protrudes inside the cylindrical portion through the taper hole and is fitted into the recess.
[0031]
When the welding torch in the automatic welding apparatus of the present invention is for arc welding, the exchange means includes a cutting means for cutting the front end portion of the welding wire protruding outward from the tip, and a welding wire with the front end portion cut. Wire pulling means for pulling backward and removing the welding wire from the tip portion inserted into the cylindrical portion may be provided.
[0032]
In this case, the release position setting means described above may be configured to operate after the welding wire is drawn by the wire drawing means.
If the welding wire is drawn in this way, there is no problem even if the insertion means inserts the replacement tip into the cylindrical portion without considering the position of the welding wire precisely.
[0033]
That is, for example, when the insertion means inserts the replacement tip when the welding wire is not drawn as described above and the welding wire remains at the position where the tip is disposed, the replacement means is used. It is necessary to precisely control the axial center position of the replacement tip so that the replacement tip can be inserted into the cylindrical portion while the welding wire is inserted into the tip.
[0034]
On the other hand, when the welding wire is pulled in as described above, the axial center position of the replacement tip may be adjusted to such an extent that the replacement tip can be inserted into the cylindrical portion.
When the welding wire is drawn in this way, after the position of the outer cylindrical portion is set by the fixed position setting means, the welding wire is passed through the tip portion inserted into the cylindrical portion, and the front end of the wire It is preferable to provide a wire feeding means for projecting the portion from the chip to the outside. By doing in this way, arc welding using the exchange front-end | tip part can be performed.
[0035]
It is desirable to configure the welding torch so that the process of passing the welding wire into the tip by the wire delivery means is appropriately executed.
Specifically, when the position of the outer cylindrical portion is set by the fixed position setting means, the axis of the tip of the replacement is positioned at a position where the welding wire can be inserted by the spherical member fitted into the recess. It may be desirable to construct a welding torch.
[0036]
Furthermore, you may provide the wire length adjustment means which adjusts the protrusion length of the welding wire protruded outside the chip | tip by the wire sending means.
For example, the wire length adjusting means may adjust the protruding length of the welding wire by cutting the front end portion of the welding wire protruding outside the tip at a predetermined location.
[0037]
On the other hand, in the automatic welding apparatus of the present invention, the control means further comprises a determination means for determining whether or not a predetermined replacement time has been reached for the tip portion currently inserted and attached to the cylindrical portion, When the determination unit determines that the tip replacement time has come, the tip replacement control by the replacement unit may be started.
[0038]
In this way, it is possible to automatically execute a series of operations such as determination of whether or not the tip replacement time has come and the tip replacement operation itself without human intervention.
Further, the tip portion is inserted into the cylindrical portion, the rear end portion of the inner tapered surface is opposed to the tapered hole, and a part of the spherical member protrudes into the cylindrical portion through the tapered hole to form a recess. When the spherical member is locked by the inner tapered surface and the tapered portion of the tapered hole in this state, the cylindrical portion, the spherical member, and the tip portion can be electrically connected to each other. When the welding torch is configured, the control means may be configured to energize the tip portion by energizing the cylindrical portion.
[0039]
In this way, for example, the welding using the tip portion can be performed without providing a special electrical route leading to the tip portion in addition to the above-described electrical route from the cylindrical portion to the tip portion through the spherical member. It becomes possible, and the effect that the structure of a welding torch is simplified is acquired.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a functional block diagram showing the configuration of the automatic welding apparatus 1 of the present embodiment in functional blocks, and FIG. 2 is a cross-sectional view showing the configuration of a welding torch 100 in the automatic welding apparatus 1.
[0041]
The automatic welding apparatus 1 of this embodiment is an apparatus for arc welding. As shown in FIG. 1, the automatic welding apparatus 1 includes a welding portion 10, an air supply portion 20, a welding wire feeding portion 30, a welding wire cutting portion 40, and these portions 10, 20, 30, 40. The control part 50 which performs control, the front-end | tip part holding | maintenance part 60, and the front-end | tip part engagement plate 70 are provided.
[0042]
The welded portion 10 includes a welding torch 100 and an arm portion 12 that is attached to the welding torch 100 and supports the moving torch 100 by moving the welding torch 100 to a predetermined welding location based on a control signal from the control unit 50. Yes.
The air supply unit 20 includes an air pump (not shown) and the like. The air supply unit 20 pressure-feeds compressed air based on a control signal from the control unit 50, and a gap 140 (described later) of the welding torch 100 via an air supply path 142 (described later). Is filled with compressed air.
[0043]
The welding wire feed unit 30 is welded by rotating a reel (not shown) around which a welding wire supplied to the welding torch 100 for arc welding is wound, or by rotating the reel based on a control signal from the control unit 50. A motor (not shown) for supplying the welding wire to the torch 100 and drawing the welding wire from the welding torch 100 is included.
[0044]
The welding wire cutting unit 40 includes an air nipper 42 (see FIG. 4A) that cuts the welding wire based on a control signal from the control unit 50.
The control unit 50 is mainly configured by a logical operation circuit including a CPU, a memory, and the like. The logical operation circuit is based on a program stored in the memory, and the welding unit 10, the air supply unit 20, the welding wire. Signals are input / output between the feeding unit 30 and the welding wire cutting unit 40.
[0045]
Further, the tip holding portion 60 is configured as a member in which at least one tip 150 (described later), which is a component of the welding torch 100, is disposed as a replacement.
In the present embodiment, the tip end holding portion 60 is configured to have a plurality of tip end holding holes 62 opened upward (see FIG. 4D). A replacement tip portion 150 is disposed in each of the plurality of tip portion holding holes 62.
[0046]
The distal end engaging plate 70 is a member for holding the distal end 150 when the distal end 150 of the welding torch 100 is pulled out for replacement, and an engaging portion 72 for engaging with the distal end. (See FIG. 4C).
Next, the configuration of the welding torch 100 of the present embodiment will be described with reference to FIG.
[0047]
The welding torch 100 includes a main body part 110 and a tip part 150 that is detachably attached to the front end side of the main body part 110.
The main body 110 includes a torch main body 115 having a through hole 116 through which the welding wire 3 can be inserted, a cylindrical portion 120 having the torch main body 115 mounted therein, and the cylindrical portion 120 surrounding the cylindrical portion 120. And an outer tubular portion 130 that is arranged to be movable in the front direction X1 or the rear direction X2 with respect to the portion 120.
[0048]
The torch main body 115 is fitted in a rear portion inside the cylindrical portion 120. The front part inside the cylindrical part 120 is a tip part insertion hole 122 that opens forward so that the rear end part of the tip part 150 can be inserted.
The front end surface 117 of the torch main body 115 functions as a contact portion for performing rough positioning of the front end portion 150 by contacting the rear end surface 152 of the front end portion 150 when the front end portion 150 is attached to the main body portion 110. have.
[0049]
The cylindrical part 120 has a plurality of tapered holes 124 in the front portion thereof, with the narrow diameter side on the inside and penetrating the members forming the cylindrical part 120. A spherical member 126 is disposed in each tapered hole 124. The spherical member 126 is a member made of a material having at least a surface portion having conductivity. For example, the spherical member 126 is made of a brass ball or a spherical member whose surface is plated with silver.
[0050]
An inner tapered surface 132 whose inner diameter is increased toward the front end side is provided on the inner wall surface of the front portion of the outer cylindrical portion 130.
As shown in FIG. 2, the outer cylindrical portion 130 is pushed relatively forward X1 with respect to the cylindrical portion 120, and the rear end portion of the inner tapered surface 132 faces the tapered hole 124. Is arranged, the spherical member 126 is pushed against the inner tapered surface 132.
[0051]
A part of the spherical member 126 protrudes to the inside of the cylindrical portion 120 through the tapered hole 124. In this state, the spherical member 126 is sandwiched between the inner tapered surface 132 and the tapered portion of the tapered hole 124.
Conversely, the outer cylindrical portion 130 is pushed relatively rearward X2 with respect to the cylindrical portion 120, and the outer cylindrical portion 130 is disposed so that the front end portion of the inner tapered surface 132 faces the tapered hole 124. Then, the holding of the spherical member 126 by the inner tapered surface 132 and the tapered portion of the tapered hole 124 is released.
[0052]
On the other hand, in the present embodiment, an annular first support portion 134 extending in the circumferential direction is attached to the inner wall of the outer cylindrical portion 130. The first support part 134 includes an annular member 134a attached to the inner wall of the outer cylindrical part 130, and a sealing member 134b.
The annular member 134a is disposed so as to surround the tubular portion 120, and has an annular recess in an inner portion facing the outer wall side of the tubular portion 120. And the sealing member 134b is engage | inserted by this recessed part. The sealing member 134b is made of an elastic member such as rubber-like resin (for example, fluorine rubber) and has an annular shape (for example, configured as an O-ring or the like). The sealing member 134b is disposed so as to be airtight with respect to the outer wall of the cylindrical portion 120.
[0053]
A front end of an urging member 138 configured as a spring-like member or the like is disposed at the rear end of the first support portion 134. The urging member 138 extends in the front-rear direction at a position between the inner wall of the outer cylindrical portion 130 and the outer wall of the cylindrical portion 120, and the rear end thereof is the torch body 115 at the rear of the outer cylindrical portion 130. It arrange | positions at the 2nd support part 139 attached to the outer wall part.
[0054]
The outer cylindrical portion 130 is urged forward by the urging force of the urging member 138, and in a steady state where an urging force due to air pressure described later does not act, as shown in FIG. The side portion and the tapered hole 124 face each other. At this time, the spherical member 126 is sandwiched between the inner tapered surface 132 and the tapered portion of the tapered hole 124, and a part of the spherical member 126 protrudes to the inside of the cylindrical portion 120 through the tapered hole 124.
[0055]
On the other hand, an airtightness imparting portion 128 is provided at a location between the inner wall of the outer cylindrical portion 130 and the outer wall of the cylindrical portion 120 in front of the first support portion 134.
The airtight provision part 128 is provided with the annular recessed part 128a provided in the outer wall of the cylindrical part 120 over the perimeter, and the cyclic | annular sealing member 128b inserted by this annular recessed part 128a over the perimeter. The sealing member 128b is made of an elastic member in the same manner as the above-described sealing member 134b, and an airtight state is established between the inner wall of the outer cylindrical portion 130 and the outer wall of the cylindrical portion 120 at the place where the sealing member 128b is disposed. Has been granted.
[0056]
In the present embodiment, a gap 140 is defined in a region between the inner wall of the outer cylindrical portion 130 and the outer wall of the cylindrical portion 120 between the first support portion 134 and the airtightness imparting portion 128. An air supply path 142 (corresponding to a fluid supply path) connected to the air supply section 20 is connected to the gap 140.
[0057]
When compressed air is filled in the gap 140 via the air supply path 142 due to the function of the air supply unit 20, the outer cylindrical portion 130 resists urging by the urging member 138 due to the air pressure. Moved backwards.
At that time, the outer cylindrical portion 130 is disposed so that the front end portion of the inner tapered surface 132 faces the tapered hole 124, and the spherical member 126 is held between the inner tapered surface 132 and the tapered portion of the tapered hole 124. Canceled.
[0058]
On the other hand, the tip portion 150 is connected to the tip portion main body 151 having a through hole 154 into which the welding wire 3 can be inserted and the front end of the tip portion main body 151, and the welding wire 3 that has passed through the through hole 154 in a contact state. A chip 160 having a through-hole 162 to be passed therethrough and a nozzle 165 provided so as to surround the chip 160 are provided.
[0059]
A rear portion 151 a of the tip body 151 is configured to be inserted into the tip insertion hole 122 of the cylindrical portion 120. An annular recess 156 extending in the circumferential direction is provided on the outer peripheral surface of the tip body 151 at a location corresponding to the tapered hole 124 of the cylindrical portion 120, and the recess 156 has the small diameter side as an inner side. It is made into the taper-shaped recessed part.
[0060]
In this embodiment, the gap 140 is filled with compressed air and the outer cylindrical portion 130 is moved rearward, and the nipping of the spherical member 126 by the inner tapered surface 132 and the tapered portion of the tapered hole 124 is released. When the rear portion 151a is inserted into the distal end portion insertion hole 122, the spherical member 126 is pushed out in the radially outer direction of the cylindrical portion 120 (direction approaching the inner tapered surface 132) by the inserted rear portion 151a.
[0061]
The spherical member 126 is in contact with the outer peripheral surface 151b until the rear end surface 152 of the distal end main body 151 contacts the front end surface 117 of the torch main body 115. When the rear end surface 152 comes into contact with the front end surface 117 and the front end portion 150 is roughly positioned, the concave portion 156 faces the tapered hole 124. Then, when the supply of compressed air from the air supply unit 20 to the gap 140 is cut off and the compressed air filled in the gap 140 is discharged through the air supply path 142, the biasing force of the biasing member 138 causes The outer cylindrical part 130 is moved forward.
[0062]
At this time, the spherical member 126 is sandwiched between the inner tapered surface 132 and the tapered portion of the tapered hole 124. Then, as shown in FIG. 2, a part of the spherical member 126 protrudes inside the cylindrical portion 120 through the tapered hole 124 and is fitted into the concave portion 156, and the distal end portion 150 is locked to the main body portion 110. The
[0063]
In the present embodiment, the spherical member urged by the spring force of the spring as much as the tip 150 is locked by the spherical member 126 sandwiched between the inner tapered surface 132 and the tapered portion of the tapered hole 124 as described above. Compared to the conventional case where the tip is locked to the main body by the member, the tip 150 is locked to the main body 110 with a sufficient force.
[0064]
In addition, when a part of the spherical member 126 is fitted into the recess 156, the front-rear direction position of the tip 150 with respect to the main body 110 is easily set to an appropriate position corresponding to the fitting position of the spherical member 126 into the recess 156. Is done.
In the present embodiment, as described above, the concave portion 156 of the distal end portion 150 is a tapered concave portion with the small diameter side on the inside. Therefore, even if the position of the concave portion 156 at the distal end portion 150 inserted into the cylindrical portion 120 is slightly deviated from an appropriate position facing the tapered hole 124, the spherical member 126 is inserted into the concave portion 156. As it goes on, it will be corrected to an appropriate one.
[0065]
Moreover, in this embodiment, the recessed part 156 is made into the cyclic | annular thing extended over the perimeter in the circumferential direction. Therefore, the spherical member 126 can be easily fitted into the concave portion 156 regardless of the rotational direction position where the front end portion 150 is the front-rear direction.
[0066]
In the present embodiment, a tapered surface 158 with the small diameter side as the rear end side is provided at the rear end portion of the outer peripheral surface of the front end portion main body 151. Therefore, it is easier to insert the rear portion 151a of the tip portion main body 151 into the tip portion insertion hole 122 of the cylindrical portion 120 than in the case where such a tapered surface 158 is not provided.
[0067]
In the present embodiment, the torch body 115, the cylindrical part 120, and the tip part 150 (at least the tip part body 151 and the chip 160) are made of a conductive material.
When the spherical member 126 is sandwiched between the inner tapered surface 132 and the tapered portion of the tapered hole 124 as described above and a part of the spherical member 126 is fitted into the recess 156, the torch body 115, the cylindrical portion 120, the spherical member 126, and the front-end | tip part 150 will be in the state which mutually contacted, These are comprised so that it may become an electrical continuity state mutually by supplying with electricity.
[0068]
In the present embodiment, the control unit 50 is configured to energize the cylindrical part 120 through the torch body 115. At the time of welding, the cylindrical portion 120 is energized, whereby the welding wire 3 that is in contact with the tip 160 is energized through the tip 160 of the tip 150, and arc welding is possible.
[0069]
Next, based on the program stored in the memory in the control unit 50, the flowchart shown in FIG. 3 and the welding torch at the time of execution of the control process shown in FIG. This will be described with reference to an explanatory diagram showing the state.
[0070]
As shown in FIG. 3, when the control process is started, first, a welding process is executed in S110 (S represents a step). In this process, the arm portion 12 is driven to move the welding torch 100 to a predetermined welding location, and the cylindrical portion 120 is energized, whereby the welding wire 3 held to be able to be sent out to the tip 160 is used. Arc welding is performed.
[0071]
Next, in S120, it is determined whether or not it is time to replace the tip 150 due to wear of the chip 160 or the like. In the present embodiment, a welding history such as the distance at which arc welding is performed using the same tip portion 150 is stored, and when it reaches a predetermined numerical value (for example, the distance at which arc welding is performed is 100 m). Is determined as the replacement time of the tip 150.
[0072]
If it is determined in S120 that the replacement time has not been reached (S120: NO), the process proceeds to S110. If it is determined that the replacement time has been reached (S120: YES), the process proceeds to S130.
In S 130, the arm portion 12 is driven to move the welding wire 3 protruding from the distal end portion 150 of the welding torch 100 to the vicinity of the air nipper 42 of the welding wire cutting portion 40. Then, the air nipper 42 cuts the front end portion of the welding wire 3 including the portion that is agglomerated at the tip of the welding wire 3 (see FIG. 4A).
[0073]
Next, in S140, the reel of the welding wire feeding part 30 is rotated, and the welding wire 3 in the welding torch 100 is drawn backward as indicated by an arrow a, and the inside of the distal end part 150 currently attached to the cylindrical part 120 is drawn. The welding wire 3 is excluded from the above (see FIG. 4B).
[0074]
In subsequent S150, the air supply unit 20 operates to fill the gap 140 with compressed air and move the outer cylindrical part 130 rearward as indicated by the arrow b. Thereby, the portion of the front end side of the inner tapered surface 132 is opposed to the tapered hole 124, and the nipping of the spherical member 126 by the inner tapered surface 132 and the tapered portion of the tapered hole 124 is released.
[0075]
Next, in S 160, the welding torch 100 is moved by the arm portion 12, and the engaging portion 72 of the distal end portion engaging plate 70 is engaged with the step portion 151 c of the distal end portion main body 151. In this state, the arm portion 12 moves the welding torch 100 rearward as indicated by the arrow c, thereby pulling out the distal end portion 150 inserted into the cylindrical portion 120 (see FIG. 4C).
[0076]
Next, in S 170, the arm portion 12 is driven so that one of the plurality of tip portions 150 arranged in the tip portion holding portion 60 is inserted into the tip portion insertion hole 122 of the tubular portion 120. The position of the unit 120 is set (see FIG. 4D).
At this time, while maintaining the state in which the gap 140 is filled with compressed air, the outer cylindrical portion 130 is positioned rearward as indicated by the arrow b, and the spherical member is formed by the inner tapered surface 132 and the tapered portion of the tapered hole 124. It is assumed that 126 is released.
[0077]
Therefore, in this process, the tip portion 150 can be inserted into the tip portion insertion hole 122 only by moving the main body portion 110 forward as indicated by the arrow d in FIG.
In S180, the supply of compressed air to the gap 140 is turned off, and the outer cylindrical portion 130 is moved forward as indicated by the arrow e in FIG. 4 (e). At this time, the spherical member 126 is held between the inner tapered surface 132 and the tapered portion of the tapered hole 124, and a part of the spherical member 126 is fitted into the recess 156. Thereby, the distal end portion 150 is locked to the main body portion 110.
[0078]
In subsequent S190, the reel of the welding wire feeding section 30 is rotated to feed the welding wire 3 in the torch main body 115 forward as indicated by an arrow f in FIG. 4 (e). Then, the welding wire 3 is passed through the tip portion 150 newly attached to the cylindrical portion 120 this time, and the front end portion of the welding wire 3 is projected outside from the tip 160 (see FIG. 4E).
[0079]
Next, in S 200, the arm portion 12 is driven to move the welding wire 3 protruding from the distal end portion 150 of the welding torch 100 to the vicinity of the air nipper 42. Then, the length of the welding wire 3 protruding from the tip 160 is adjusted by cutting the front end portion of the welding wire 3 at a predetermined position with the air nipper 42 (see FIG. 4F).
[0080]
Then, when the process of S200 is completed, the process proceeds to S110 again, and thereafter the processes of S110 to S200 are executed again.
In the present embodiment, by repeatedly executing the processes of S110 to S200, the welding process (S110), the determination of whether or not the replacement time of the tip 150 has arrived (S120), and the replacement work of the tip 150 The entire series of operations (S130 to S200) can be automatically executed without human intervention.
[0081]
In the above, the process of S120 corresponds to the operation of the determining means, the process of S130 corresponds to the operation of the cutting means, the process of S140 corresponds to the operation of the wire drawing means, and the process of S150 is the release position setting means. It corresponds to the operation. The process of S160 corresponds to the operation of the pulling means, the process of S170 corresponds to the operation of the insertion means, the process of S180 corresponds to the operation of the fixed position setting means, and the process of S190 corresponds to the operation of the wire sending means. Correspondingly, the process of S200 corresponds to the operation of the wire length adjusting means.
[0082]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various aspect can be taken.
For example, in the above embodiment, as shown in FIG. 2, in the welding torch 100, the distal end portion 150 is configured as a linear member extending in the front-rear direction, but FIGS. ), The tip portion may be configured as a tip portion 150 ′ having a curved portion 201 in the axial direction.
[0083]
If it does in this way, the welding to the location which cannot be welded using the linear front-end | tip part 150 over the full length may be attained.
5A and 5B, parts having the same configuration as in the case of the welding torch 100 shown in FIG. Omitted.
[0084]
In the case of the welding torch 100 ′ shown in FIGS. 5 (a) and 5 (b), the tip portion 150 ′ attached to the main body portion 110 ′ rotates with respect to the cylindrical portion 120 ′ due to the action of an external force or the like. The anti-rotation mechanism 200 may be provided to prevent the position of the chip 160 from becoming unstable.
[0085]
For example, the anti-rotation mechanism 200 includes a cylindrical portion side engaging portion (for example, a portion configured as a fitting recess) provided at the front end portion of the cylindrical portion 120 ′ and the cylindrical portion of the distal end portion 150 ′. It may consist of a front end side engaging portion (for example, a portion configured as a protruding portion fitted in the fitting concave portion) provided at a location corresponding to the side engaging portion.
[0086]
In this case, when the distal end portion 150 ′ is inserted into the cylindrical portion 120 ′ and the rear end surface 152 of the distal end portion 150 ′ contacts the front end surface 117 of the torch main body 115, the tubular portion side engaging portion and the distal end portion It is good to be comprised so that rotation with respect to cylindrical part 120 'of front-end | tip part 150' may be engaged with a side engaging part, and, thereby.
[0087]
On the other hand, it is preferable that the distal end portion 150 (150 ′) inserted into the cylindrical portion 120 (120 ′) is preferably prevented from rattling in the cylindrical portion 120 (120 ′). .
For example, at least one sealed state imparting portion 210 (for example, the figure) between the inner wall of the cylindrical portion 120 (120 ′) and the portion inserted into the cylindrical portion 120 (120 ′) of the distal end portion 150 (150 ′). 5 (a)) may be provided to prevent such rattling.
[0088]
As shown in FIG. 5A, the sealing state imparting portion 210 includes an annular recess 210a provided over the entire circumference of the inner wall of the cylindrical portion 120 ', and an annular seal fitted into the annular recess 210a over the entire circumference. And a member 210b. The sealing member 210b is made of an elastic member in the same manner as the above-described sealing members 128b and 134b, and is in close contact with the tip portion 150 ′ so that the tip portion 150 ′ does not rattle in the cylindrical portion 120 ′. To do.
[0089]
In addition, when the sealing state provision part 210 is comprised like Fig.5 (a), the sealing member 210b may become easy to remove | deviate from the cyclic | annular recessed part 210a depending on the structure. Therefore, in order to suitably prevent such detachability, the sealing state imparting portion may be a member 220 provided on the outer wall of the tip portion 150 ′ as shown in FIG. In this case, the sealing state imparting portion 220 is fitted over the entire circumference of the annular recess 220a provided over the entire circumference of the outer wall of the portion inserted into the cylindrical portion 120 ′ of the tip portion 150 ′. And an annular sealing member 220b. The sealing member 220b is made of an elastic member in the same manner as the sealing member 210b described above, and is in close contact with the inner wall of the cylindrical portion 120 ′ so that the distal end portion 150 ′ does not rattle within the cylindrical portion 120 ′. .
[0090]
Moreover, in the said embodiment, although the automatic welding apparatus 1 demonstrated that it was an apparatus for arc welding, if it was provided with the welding torch which has a replaceable front-end | tip part, another kind of automatic welding apparatus Even so, the present invention is applicable.
For example, the present invention can naturally be applied to an automatic welding apparatus for spot welding, and FIGS. 7A to 7C show other embodiments in which the present invention is applied to a welding torch 300 for spot welding. FIG.
[0091]
The welding torch 300 includes a main body portion 310 and a replaceable tip portion 350 that is detachably attached to the front end side of the main body portion 310.
7A to 7C, parts having the same configuration as in the case of the welding torch 100 shown in FIG. In FIG. 7A, the airtightness imparting portion 128, the first support portion 134, the gap portion 140, and the air supply path 142 are illustrated, but in FIGS. 7B and 7C, these are illustrated. Is omitted.
[0092]
Unlike the automatic welding apparatus 1 described in the above embodiment, the automatic welding apparatus including the welding torch 300 does not use the welding wire 3. Therefore, in this automatic welding apparatus, the welding wire feed part 30 and the welding wire cutting part 40 are omitted from the configuration shown in FIG. Also, S130, S140, S190, and S200 are omitted from the processes shown in FIG.
[0093]
Also in the automatic welding apparatus provided with this welding torch 300, the tip portion 350 can be replaced by performing processing corresponding to S120 and S150 to S180 shown in FIG.
That is, first, when it is determined that it is time to replace the tip 350 while continuing the welding process (S120: YES, see FIG. 7A), the outer tubular portion 130 is moved backward. Then, the holding of the spherical member 126 by the inner tapered surface 132 and the tapered portion of the tapered hole 124 is released (S150, see FIG. 7B).
[0094]
Next, the distal end portion 350 inserted into the cylindrical portion 120 is pulled out (S160, see FIG. 7C). Then, the replacement tip 350 is inserted into the cylindrical portion 120 (S170), the outer cylindrical portion 130 is moved forward, and the spherical member 126 is sandwiched between the inner tapered surface 132 and the tapered portion of the tapered hole 124. (S180). At this time, a part of the spherical member 126 is fitted into the recess 156, whereby the tip 350 is locked to the main body 310 (see FIG. 7A).
[0095]
In the case of this automatic welding apparatus, in the processing corresponding to S120, for example, a welding history such as the number of times of welding (the number of welding points) using the same tip portion 350 is stored, and the predetermined number of times is stored. The time point at which the tip part 350 is reached (for example, the time point when the number of spot weldings reaches 500 times) may be determined as the replacement time of the tip portion 350.
[0096]
Even in the case of an automatic welding apparatus equipped with such a welding torch 300, the front end portion 350 can be locked to the main body portion 310 with sufficient force, and the front end portion 350 is fixed to the main body portion 310 at the time of locking. On the other hand, it is possible to obtain the same effect as that of the above-described embodiment, such as being able to be easily locked at an appropriate front-rear position.
[0097]
In this automatic welding apparatus, a cooling fluid passage for flowing a cooling fluid for cooling the welding torch is provided in the welding torch 300, and a fluid force imparting means such as a pump for imparting a fluid force to the coolant is provided. If there is, a process for stopping the flow of the coolant may be performed between the process corresponding to S120 and the process corresponding to S150. In this case, a process for resuming the flow of the coolant may be performed after the process corresponding to S180.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing the configuration of an automatic welding apparatus according to an embodiment in functional blocks.
FIG. 2 is a cross-sectional view showing a configuration of a welding torch in the automatic welding apparatus of the embodiment.
FIG. 3 is a flowchart illustrating a control process executed by a control unit of the automatic welding apparatus according to the embodiment.
FIG. 4 is an explanatory view showing a state of a welding torch when a control process is executed.
FIG. 5 is a cross-sectional view showing a configuration of a welding torch according to another embodiment.
FIG. 6 is a cross-sectional view showing a configuration of a welding torch according to another embodiment.
FIG. 7 is a cross-sectional view showing a configuration of a welding torch according to another embodiment and a state at the time of replacement of a tip portion of the welding torch.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Automatic welding apparatus, 3 ... Welding wire, 10 ... Welding part, 20 ... Air supply part, 30 ... Welding wire feed part, 40 ... Welding wire cutting part, 50 ... Control part, 60 ... Tip part holding part, 70 ... Tip engagement plate, 100, 100 ', 300 ... welding torch, 110, 110', 310 ... main body, 115 ... torch main body, 117 ... front end surface, 120, 120 '... cylindrical portion, 124 ... taper hole, 126 ... spherical member, 128 ... airtight imparting portion, 130 ... outer cylindrical portion, 132 ... inner tapered surface, 134 ... first support portion, 138 ... biasing member, 139 ... second support portion, 140 ... gap portion, 142 ... Air supply path, 150, 150 ', 350 ... Tip, 151 ... Tip body, 152 ... Rear end face, 156 ... Recess, 160 ... Tip, 165 ... Nozzle, 201 ... Curved part

Claims

A welding torch having a main body part and a tip part detachably attached to the front end side of the main body part,
The outer peripheral surface of the tip is provided with a recess,
The body part is
A cylindrical portion for inserting the tip portion;
An outer tubular portion that surrounds the tubular portion and is arranged to be movable in the front-rear direction with respect to the tubular portion;
The cylindrical portion has a tapered hole penetrating a member forming the cylindrical portion with the small diameter side inside, and a spherical member is disposed in the tapered hole,
The inner wall surface of the outer cylindrical portion is provided with an inner tapered surface whose inner diameter is increased toward the front end side,
When the outer cylindrical portion is disposed so that the tip portion is inserted into the cylindrical portion and the rear end portion of the inner tapered surface faces the tapered hole, a part of the spherical member is It protrudes inside the cylindrical part through the tapered hole and is fitted into the concave part, and in this state, the spherical member is sandwiched between the inner tapered surface and the tapered part of the tapered hole,
When the outer cylindrical portion is disposed so that the front end portion of the inner tapered surface faces the tapered hole, the spherical member is locked by the inner tapered surface and the tapered portion of the tapered hole. A welding torch configured to be released and to be able to be pulled out from the cylindrical portion.

3. The welding torch according to claim 1, wherein the concave portion of the tip portion is a tapered concave portion with a small diameter side as an inner side.

The welding torch according to any one of claims 1 to 3, wherein the concave portion of the tip portion is an annular concave portion extending in a circumferential direction on an outer peripheral surface of the tip portion.

The cylindrical portion of the main body has a plurality of tapered holes, and a spherical member is disposed in each of the tapered holes,
When the outer cylindrical portion is disposed such that the tip portion is inserted into the cylindrical portion and the rear end portion of the inner tapered surface faces the plurality of tapered holes, the plurality of tapered holes are formed. 5. The concave portion is configured such that a part of the plurality of spherical members protruding to the inside of the cylindrical portion is fitted into the concave portion of the tip portion. The welding torch described in 1.

The body part is
By urging the outer cylindrical portion forward, a portion of the inner tapered surface on the rear end side is opposed to the tapered hole, and a part of the spherical member is formed on the cylindrical portion via the tapered hole. The welding according to any one of claims 1 to 5, further comprising a biasing means for locking the spherical member by the inner tapered surface and a tapered portion of the tapered hole in a state of protruding inward. torch.

The body part is
The outer cylindrical portion is moved rearward against the urging by the urging means, the front end portion of the inner tapered surface is opposed to the tapered hole, and the inner tapered surface and the tapered hole are tapered. The welding torch according to claim 6, further comprising: a lock release means for releasing the locking of the spherical member by the portion and enabling the tip portion to be pulled out from the cylindrical portion. .

The biasing means is
A first support portion attached to the inner wall of the outer tubular portion;
A front end is disposed on the first support portion, and extends in the front-rear direction at a location between the inner wall of the outer cylindrical portion and the outer wall of the cylindrical portion, and moves the outer cylindrical portion forward. A biasing member for applying a force to the outer tubular portion;
A second support provided on a portion of the main body, on which a rear end of the biasing member is disposed;
The welding torch according to claim 6 or 7, further comprising:

The biasing means is
A first support part attached to the inner wall of the outer cylindrical part and arranged to be airtight with respect to the outer wall of the cylindrical part;
A front end is disposed at a rear end of the first support portion, and extends in a front-rear direction at a position between an inner wall of the outer cylindrical portion and an outer wall of the cylindrical portion, and the outer cylindrical portion is moved forward. A biasing member that imparts a biasing force to move to the outer cylindrical portion;
A second support portion provided at a portion of the main body portion, on which a rear end of the urging member is disposed,
The unlocking means is
The first support part;
An air-tightness imparting portion that imparts an airtight state between the inner wall of the outer tubular portion and the outer wall of the tubular portion at a location ahead of the first support portion;
A gap defined in a region between the inner wall of the outer cylindrical part and the outer wall of the cylindrical part between the first support part and the hermeticity imparting part;
8. A fluid supply path connected to the gap portion for supplying a predetermined fluid to the gap portion and discharging the fluid from the gap portion. Welding torch.

The welding torch according to any one of claims 1 to 9, wherein the tip has a curved portion in the axial direction.

The welding torch is for arc welding,
The tip is
A tip for holding the welding wire in a deliverable manner;
A nozzle surrounding the chip;
The welding torch according to claim 1, comprising:

The tip part is inserted into the cylindrical part, the rear end part of the inner tapered surface is opposed to the tapered hole, and a part of the spherical member is located inside the cylindrical part via the tapered hole. When the spherical member is locked by the inner tapered surface and the tapered portion of the tapered hole in this state, the cylindrical portion, the spherical member, and the tip portion are The welding torch according to claim 1, wherein the welding torch is configured to be in an electrically conductive state with each other.

An automatic welding apparatus comprising: the welding torch according to any one of claims 1 to 12; and a control unit that controls the welding torch.

An automatic welding apparatus comprising: the welding torch according to any one of claims 1 to 11; and a control unit that controls the welding torch.
A tip holding portion on which at least one replacement tip is disposed;
The control means has an exchange means for performing exchange control of the tip of the welding torch,
The exchange means is
The position of the outer cylindrical portion is set so that the front end side portion of the inner tapered surface faces the tapered hole, and the locking of the spherical member by the inner tapered surface and the tapered portion of the tapered hole is released. Release position setting means that enables the tip portion to be pulled out from the tubular portion;
A pulling means for pulling out the tip part inserted into the cylindrical part after the position setting of the outer cylindrical part by the release position setting means;
An insertion means for inserting the replacement distal end portion disposed in the distal end portion holding portion into the tubular portion after the distal end portion is pulled out by the withdrawal means;
After the insertion of the tip for replacement by the insertion means, the outer cylindrical portion is positioned so that the rear end portion of the inner tapered surface faces the tapered hole, and the spherical member is moved to the inner portion. A fixed position setting means that is locked by a tapered surface and a tapered portion of the tapered hole so that a part of the spherical member protrudes inside the cylindrical portion through the tapered hole and is fitted into the recessed portion. When,
An automatic welding apparatus comprising:

An automatic welding apparatus comprising the welding torch according to claim 11 and a control means for controlling the welding torch,
A tip holding portion on which at least one replacement tip is disposed;
The control means has an exchange means for performing exchange control of the tip of the welding torch,
The exchange means is
Cutting means for cutting a front end portion of the welding wire protruding outward from the tip;
Wire pulling means for pulling the welding wire with the front end portion cut backward, and removing the welding wire from the tip portion inserted into the tubular portion;
After the welding wire is drawn by the wire drawing means, the position of the outer cylindrical portion is set so that the front end portion of the inner tapered surface faces the tapered hole, and the inner tapered surface and the tapered hole are Release position setting means for releasing the locking of the spherical member by the taper portion, and enabling the tip portion to be pulled out from the cylindrical portion,
A pulling means for pulling out the tip part inserted into the cylindrical part after the position setting of the outer cylindrical part by the release position setting means;
An insertion means for inserting the replacement distal end portion disposed in the distal end portion holding portion into the tubular portion after the distal end portion is pulled out by the withdrawal means;
After the insertion of the tip for replacement by the insertion means, the outer cylindrical portion is positioned so that the rear end portion of the inner tapered surface faces the tapered hole, and the spherical member is moved to the inner portion. A fixed position setting means that is locked by a tapered surface and a tapered portion of the tapered hole so that a part of the spherical member protrudes inside the cylindrical portion through the tapered hole and is fitted into the recessed portion. When,
After the position setting of the outer tubular portion by the fixed position setting means, the wire is passed through the tip inserted into the tubular portion, and the front end of the wire is projected from the tip to the outside. Means,
An automatic welding apparatus comprising:

The control means includes
A determination means for determining whether or not a predetermined replacement time has been reached for the tip portion currently inserted and attached to the cylindrical portion,
The automatic welding apparatus according to claim 14 or 15, wherein when the determination means determines that the time for replacement of the tip end has been reached, replacement control of the tip end by the replacement means is started. .

The welding torch is
The tip portion is inserted into the cylindrical portion, a rear end portion of the inner tapered surface is opposed to the tapered hole, and a part of the spherical member is located inside the cylindrical portion via the tapered hole. When the spherical member is locked by the inner tapered surface and the tapered portion of the tapered hole in this state, the cylindrical portion, the spherical member, and the tip portion are Configured to be electrically conductive with each other,
17. The automatic welding apparatus according to claim 13, wherein the control unit energizes the tip part by energizing the cylindrical part.