JP3700906B2

JP3700906B2 - Electric gun

Info

Publication number: JP3700906B2
Application number: JP14669498A
Authority: JP
Inventors: 和嗣吹田; 豊小西; 啓之坂倉; 滋梅田; 良夫佐藤
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 1998-05-13
Filing date: 1998-05-13
Publication date: 2005-09-28
Anticipated expiration: 2018-05-13
Also published as: JPH11320112A

Description

【０００１】
【発明の属する技術分野】
本発明は、先端に相対向する電極を備えた第１および第２ガンア―ムを軸支してなるＸ型電動溶接機の第１ガンア―ムから分岐した第３ガンア―ムを形成すると共に、前記第２ガンア―ムから延長した又は連結部に独立して回動自在に軸支した第４ガンア―ムを形成し、第３ガンア―ムの先端に設けた電極に第４ガンア―ムの先端に設けた電極を対向させ、前記第１および第２ガンア―ムの連結部より後方に配置した電動機の出力軸に減速機を接続し、該減速機の出力側に設けた動力伝達機構により前記第２および第４ガンア―ムを回動させるようにした電動ガンに関し、特にそのア―ムの回動装置に関するものである。
【０００２】
【従来の技術】
従来、先端に相対向する電極を備えた第１および第２ガンア―ムを軸支してなるＸ型電動溶接機の第１ガンア―ムから分岐した第３ガンア―ムを形成すると共に、前記第２ガンア―ムから延長した第４ガンア―ムを形成し、第３ガンア―ムの先端に設けた電極に第４ガンア―ムの先端に設けた電極を対向させ、エアシリンダのピストンロッドにより前記第２および第４ガンア―ムを回動させるようにした溶接ガン（以下，前者という）は公知である（例えば実公昭５２ー４４５８２号公報参照）。
【０００３】
また、Ｘ型電動ガンにおいて、サ―ボモ―タの容量を小さく抑えて高加圧力を得るために、ガンブラケットと一体化した第１ガンア―ムに対してガンブラケットに回動自在に軸支された第２ガンア―ムをサ―ボモ―タ，減速装置を介して減速装置の出力側に固定された出力円板と該出力円板の外周寄り位置に設けたピンと該ピンと前記第２ガンア―ムの後端間を連結するように設けられたコネクタア―ム（リンク）によって構成されたクランク機構（加圧機構）によって加圧するようにしたもの（以下，後者という）がある（例えば特開平９ー２４８６７８号公報参照）。
【０００４】
【発明が解決しようとする課題】
ところで前記公知の前者の溶接ガンでは、エアシリンダからのピストンロッドをガンア―ムの駆動に用いているため、加圧力の調整や開放ストロ―クの調整が困難である、という問題がある。
【０００５】
また、前記公知の後者のガンア―ムの回動手段では、サ―ボモ―タの容量を小さく抑えるために、減速装置を介した出力円板の中心と該円板の外周寄り位置に設けたピンの中心を結ぶ線と、前記第２ガンア―ムの後端と前記ピンをつなぐリング、とのなす角度が１８０度となる少し手前に位置で加圧動作を行わせ、所謂トグル機構を利用して加圧力の増大を図っている。ところが、このような加圧手段では、円板の回転トルクに対するリンクの出力の関係から、円板の回転角度の変化量に対して加圧力の変化度合が大きく、それも一次関数的な変化ではなく、１８０度に近付くほど指数関数的に変化し、ピンとリンクのなす角度の少しの変化で電極加圧力は大きく変化するものである。そして、溶接機の実使用上では、電極の摩耗量の変化の他にア―ムの撓み量が各加圧力毎に変化することと主軸部を含めた各支持ピン軸受の経年摩耗の変化によって上記角度が変化して安定した角度が得難いものである。そのため、円板の回転角度の変化量に対して加圧力が指数関数的に変化するトグル機構の特性から、前記公知の技術では設定加圧値に合った正確な加圧力を得るように制御することは極めて難しい、という問題がある。
【０００６】
本発明は、従来の技術の有するこのような問題点に鑑みてなされたものであり、その目的とするところは、第１ないし第４ガンア―ムを備えた２セットの電極を有する電動ガンにおいて各セットにおける加圧力の調整や開放ストロ―クの調整が極めて容易であり、且つ電極や軸受の摩耗や各加圧力毎に変化するガンア―ムの撓み等に電極加圧力が影響を受けることなく、簡単な制御で設定した加圧力に対して正確な加圧力が出力され、安定した加圧力が得られる電動ガンを提供しようとするものである。
【０００７】
【課題を解決するための手段】
上記目的を達成するために、本発明における電動ガンは、それぞれ先端に電極を有する第１ないし第４ガンア―ムを備え、第１ガンア―ムの電極を第２ガンア―ムの電極と、第３ガンア―ムの電極を第４ガンア―ムの電極とそれぞれ相対向させて２セットの電動ガンとし、第１及び第３ガンア―ムを固定ア―ムとし、第２及び第４ガンア―ムを可動ア―ムとして、電動機の駆動により減速機を介して前記両可動ア―ムの電極に対して、一方の電極が加圧動作時に他方の電極に開放動作を行わせると共に電動機の正転時と逆転時のトルクと回転角度を自由に変え得るようにしたことを特徴とするものである。
また、先端に相対向する電極を備えた第１および第２ガンア―ムを軸支してなるＸ型電動溶接機の第１ガンア―ムから分岐した第３ガンア―ムを形成すると共に、前記第２ガンア―ムから延長した第４ガンア―ムを形成し、第３ガンア―ムの先端に設けた電極に第４ガンア―ムの先端に設けた電極を対向させ、前記第１および第２ガンア―ムの連結部より後方に配置した電動機の出力軸にガンブラケットに固定した減速機を接続し、該減速機の出力側に設けた動力伝達機構により前記第２および第４ガンア―ムを回動させるようにし、該動力伝達機構が、減速機の出力側に固定された揺動レバ―と、該レバ―と第２ガンア―ム間又は第４ガンア―ム間に形成されたリンクとからなり、前記揺動レバ―とリンクはガンブラケットを固定節としたほぼ平行四節リンクの構成要員とし、前記電動機軸のトルクと、前記揺動レバ―の先端からリンクを介して電極に伝達される電極加圧力とがほぼ線形関係にあるように揺動レバ―とリンクを連結し、且つ第１および第２ガンア―ムの加圧動作時に第３および第４ガンア―ムが開放動作を行わせると共に電動機の正転時と逆転時のトルクと回転角度を自由に変え得るようにしたことを特徴とするものである。
【０００８】
また、先端に相対向する電極を備えた第１および第２ガンア―ムを軸支してなるＸ型電動溶接機の第１ガンア―ムから分岐した第３ガンア―ムを形成すると共に、前記第２ガンア―ムから延長した第４ガンア―ムを形成し、第３ガンア―ムの先端に設けた電極に第４ガンア―ムの先端に設けた電極を対向させ、前記第１および第２ガンア―ムの連結部より後方に配置した電動機の出力軸にガンブラケットに固定した減速機を接続し、該減速機の出力側に設けた動力伝達機構により前記第２および第４ガンア―ムを回動させるようにし、該動力伝達機構が、減速機の出力側に固定された揺動レバ―と、該レバ―と第２ガンア―ム間又は第４ガンア―ム間に形成されたリンクとからなり、前記揺動レバ―とリンクはガンブラケットを固定節としたほぼ平行四節リンクの構成要員とし、前記電動機軸のトルクと、前記揺動レバ―の先端からリンクを介して電極に伝達される電極加圧力とがほぼ線形関係にあるように揺動レバ―とリンクを連結し、且つ第１および第２ガンア―ムの加圧動作時に第３および第４ガンア―ムが開放動作を行わせると共に電動機の正転時と逆転時のトルクと回転角度を自由に変え得るようにしたことを特徴とするものである。
【０００９】
また、先端に相対向する電極を備えた第１および第２ガンア―ムを軸支してなるＸ型電動溶接機の第１ガンア―ムから分岐した第３ガンア―ムを形成すると共に、前記第２ガンア―ムから延長した第４ガンア―ムを形成し、第３ガンア―ムの先端に設けた電極に第４ガンア―ムの先端に設けた電極を対向させ、前記第１および第２ガンア―ムの連結部より後方に配置した電動機の出力軸に減速機を接続し、該減速機の出力側に設けた動力伝達機構により前記第２および第４ガンア―ムを回動させるようにし、該動力伝達機構が、減速機の出力側に固定された揺動レバ―と、該揺動レバ―に設けた溝又はロ―ラと、前記第２ガンア―ムに設けたロ―ラ又は溝とからなり、揺動レバ―の揺動時に減速機の出力軸とロ―ラと連結部とが同一直線上になる位置を、第１および第２ガンア―ムによる加圧位置と第３および第４ガンア―ムによる加圧位置のほぼ中間位置にし、前記電動機軸のトルクと、前記揺動レバ―の先端からロ―ラ又は溝を介して電極に伝達される電極加圧力とがほぼ線形関係にあるように、前記揺動レバ―の先端を第２ガンア―ムに設けたロ―ラ又は溝を揺動レバ―の先端の溝又はロ―ラに接続し、且つ第１および第２ガンア―ムが加圧動作時に第３および第４ガンア―ムが開放動作を行わせると共に電動機の正転時と逆転時のトルクと回転角度を自由に変え得るようにしたことを特徴とするものである。
【００１０】
また、先端に相対向する電極を備えた第１および第２ガンア―ムを軸支してなるＸ型電動溶接機の第１ガンア―ムから分岐した第３ガンア―ムを形成すると共に、前記第２ガンア―ムから延長した第４ガンア―ムを形成し、第３ガンア―ムの先端に設けた電極に第４ガンア―ムの先端に設けた電極を対向させ、前記第１および第２ガンア―ムの連結部より後方に配置した電動機の出力軸に減速機を接続し、該減速機の出力側に設けた動力伝達機構により前記第２および第４ガンア―ムを回動させるようにし、該動力伝達機構が、減速機の出力側に固定されたギヤと、第２ガンア―ムに設けられたギヤとからなり、これら両ギヤの噛合い箇所を減速機の出力軸と連結部を結ぶ直線上にほぼ位置させ、前記電動機軸のトルクと、前記減速機の出力側に固定されたギヤから第２ガンア―ムに設けられたギヤを介して電極に伝達される電極加圧力とがほぼ線形関係にあるように減速機の出力側に固定されたギヤと第２ガンア―ムに設けられたギヤとを噛み合わせ、且つ第１および第２ガンア―ムが加圧動作時に第３および第４ガンア―ムが開放動作を行わせると共に電動機の正転時と逆転時のトルクと回転角度を自由に変え得るようにしたことを特徴とするものである。
【００１１】
【発明の実施の形態】
添付図面を参照して本発明の実施例について説明する。
図１は本発明に係る電動ガンの側面図、図２はその平面図、図３は本発明に係る電動ガンの他の実施例の側面図、図４は更に他の実施例の側面図、図５は更にまた他の実施例の側面図であり、いずれの図も二次電流回路等についてはその図示を省略している。
【００１２】
図１および図２において、１は固定ガンア―ムであり本発明における第１ガンア―ムを構成するものであって、先端に電極２を備えていると共に、後端は枢軸からなる連結部３に固定されている。また、４は可動ガンア―ムであり本発明における第２ガンア―ムを構成するものであって、先端に前記電極２と対向する電極５を備え中間上部にはリンク６が接続されていると共に、後端は前記枢軸からなる連結部３に回動可能に軸支されている。そして、これら第１ガンア―ム１と第２ガンア―ム４とでＸ型電動溶接機を構成している。また、前記第１ガンア―ム１の中間から下方に固定ガンア―ムである第３ガンア―ム７が分岐され該第３ガンア―ム７の先端には電極８が備えられ、更に前記第２ガンア―ム４の後端の連結部３からは可動ガンア―ムである第４ガンア―ム９が延長され該第４ガンア―ム９の先端には前記電極８と対向する電極１０が備えられている。
【００１３】
また、１１はガンブラケットであり、該ガンブラケット１１の先端には前記枢軸からなる連結部３が形成されていると共に、後端は図示しないロボットの手首に接続されるようになっている。そして、該ガンブラケット１１の中間上方には電動機１２が取付けられ、該電動機１２の出力軸１３とガンブラケット１１内に配置された減速機１４とは例えばベルト伝動装置１５によって接続されている。
【００１４】
前記減速機１４の出力側には板体からなる揺動レバ―１６が固着されている。また、前記第２ガンア―ム４の中間上部には前記リンク６の一端が枢軸１７されており、該リンク６の他端は前記揺動レバ―１６の先端に枢軸１８されている。そして、揺動レバ―１６の中心点１９と連結部３間のガンブラケット１１と、揺動レバ―１６と、リンク６と、軸１７と連結部３間のア―ム４とで動力伝達機構はガンブラケット１１を固定節としたほぼ平行四節リンクを形成するようになっている。なお、２０は前記ガンブラケット１１の後部に取付けられた溶接機用トランスである。
【００１５】
上記のような構成からなる電動ガンにおいて、電動機１２は正逆交互に回転するようになっている。そして、図１に示すように上下の電極２，５をワ―ク２１に当接・加圧させた状態（この時，電極８，１０は開放状態にある）で溶接を終了したならば、電動機１２を例えば時計方向に回転させると、その回転が減速機１４で減速されて揺動レバ―１６を時計方向に回動させ、第２ガンア―ム４はリンク６によって引かれて開放動作を行う（この時，電極８，１０は加圧動作に入る）。そして、第１および第２ガンア―ムが開放状態で電動ガンはロボットにより移動され次のワ―クに導かれて、下部の電極２をワ―クに当接させた状態で電動機１２を逆転させる。この回転が減速機１４で減速されて揺動レバ―１６を反時計方向に回動させ、第２ガンア―ム４はリンク６によって押されて加圧動作を行い（この時，電極８，１０は開放動作を行う）、図１の状態に戻り溶接作業を行う（以上は第１および第２ガンア―ムによる溶接作業を行わせ、第３および第４ガンア―ムによる溶接作業は行わせない場合の説明である）。
【００１６】
そして、図１の状態から第３および第４ガンア―ムによる溶接作業を行わせるには、電極８にワ―クを当接させて、電動機１２を例えば時計方向に回転させて電極８，１０を加圧動作させ、第３および第４ガンア―ムによる溶接作業が終了したならば、電動機１２を逆転させて電極８，１０を開放状態とすればよい。
【００１７】
このように、該電動ガンにおいては、電動機１２の急速回転が減速機１４で減速された後、揺動レバ―１６とリンク６を介して第２ガンア―ム４および第４ガンア―ム９を開放或は加圧動作させるので、電動機１２の軸換算の慣性モ―メント値が小さくなり、その結果，電動ガンの電極開閉時の加減速時間が短くなって溶接機の打点速度の短縮が有効に望めるものである。また、減速機１４で出力を増幅した後に揺動レバ―１６，リンク６を介して第２ガンア―ム４および第４ガンア―ム９を開放或は加圧動作させるので、電極５，１０よる加圧力にばらつきが生ずることが少なく所望の溶接ができ、しかも、比較的に直径の大きな減速機１４をガンア―ム１，４の連結部３より後方に配置したため、従来例のようなガンア―ムの有効懐深さが小さくなることもなく、大きなワ―クへのガンの適用が可能となる。また、電動機１２の正転時と逆転時のトルクと回転量は自由に変えることが可能であるので、電極２，５による溶接と電極８，１０による溶接はそれぞれ独立してワ―クに最適な加圧力および開放ストロ―クを選定することができるものである。
【００１８】
そして、前述の如く、動力伝達機構は揺動レバ―１６，リンク６はガンブラケット１１を固定節としたほぼ平行四節リンクの構成要員となっていることから、揺動レバ―１６が固定された減速機１４の出力軸の出力である電動機軸１３の出力と、前記揺動レバ―１６の先端からリンク６を介して電極５，１０に伝達される電極加圧力とは比例してほぼ線形関係にあるので、簡単な制御で設定した加圧力に対して正確な加圧力が得られる。しかも、第２ガンア―ム４および第４ガンア―ム９の変位角度と揺動レバ―１６の変化角度が同一角度であるので、電極摩耗による電極位置補正や第２ガンア―ム４および第４ガンア―ム９の開放角度の制御も極めて容易である。
【００１９】
なお、以上の実施例では、リンク６を揺動レバ―１６と第２ガンア―ム４の間に設けたものについて説明をしたが、このリンク６は揺動レバ―１６と第４ガンア―ム９の間に設けても略同様の動作を行うものである。
【００２０】
次に図３に示す実施例について説明をする。この実施例の場合、揺動レバ―１６に二個のリンク接合部を設けると共に、第２ガンア―ム４および第４ガンア―ム９にそれぞれリンクを接合した以外は前の実施例と実質的に同一であるので、実質的に同一部材については同一符号を付してその説明を省略することがある。図において、揺動レバ―１６はその上下にリンク接合部を備えるように形成されている。そして、第２ガンア―ム４の中間上部にリンク６ａの一端が枢軸１７されており、該リンク６ａの他端は前記揺動レバ―１６の上部のリンク接合部に枢軸１８されている。また、第４ガンア―ム９にリンク６ｂの一端が枢軸２２されており、該リンク６ｂの他端は前記揺動レバ―１６の下部のリンク接合部に枢軸２３されている。
【００２１】
したがって、この実施例の場合、リンク６ａ，６ｂが協働して第２ガンア―ム４および第４ガンア―ム９の開閉を確実に行わせるものである。
なお、第４ガンア―ム９は第２ガンア―ム４から延長させることなく、前記連結部に独立して回動自在としてもよく、この場合には、リンク６ａによって第２ガンア―ム４が開閉され、リンク６ｂによって第４ガンア―ム９が開閉されるようになる。
【００２２】
次に図４に示す実施例について説明をする。なお、この場合も前の実施例と実質的に同一部材については同一符号を付してその説明を省略することがある。
図において、３１は第２ガンア―ム４の後部上方に取付けられたロ―ラであり、また揺動レバ―１６の先端には溝３２が形成されており、前記ロ―ラ３１は溝３２の内周に沿って移動可能になっている。
【００２３】
また、ガンブラケット１１には、溶接機用トランス２０が取付けられていると共に、該溶接機用トランス２０には、電動機の出力軸に接続された減速機１４が保持されている。
【００２４】
上記のような構成からなる電動ガンにおいて、図４に示すように上下の電極２，５をワ―ク２１に当接・加圧させた状態（この時，電極８，１０は開放状態にある）で溶接を終了したならば、電動機を反時計方向に回転させると、その回転が減速機１４で減速されて揺動レバ―１６を反時計方向に回動させ、第２ガンア―ム４はロ―ラ３１を介して揺動レバ―１６によって引かれて開放動作を行う（この時，電極８，１０は加圧動作に入る）。そして、ガンは開放状態でロボットにより移動され次のワ―クに導かれて、下部の電極２をワ―クに当接させた状態で電動機を逆転させる。この回転が減速機１４で減速されて揺動レバ―１６を時計方向に回動させ、第２ガンア―ム４はロ―ラ３１を介して揺動レバ―１６によって押されて加圧動作を行い（この時，電極８，１０は開放動作を行う）、図４の状態に戻り溶接作業を行う。なお、前記第２ガンア―ム４の開放動作および加圧動作時にロ―ラ３１は揺動レバ―１６に形成された前記溝３２の内周に沿って移動可能であるので揺動レバ―１６に無理な力が掛ることはない。（以上は第１および第２ガンア―ムによる溶接作業を行わせ、第３および第４ガンア―ムによる溶接作業は行わせない場合の説明である）。
【００２５】
そして、図４の状態から第３および第４ガンア―ムによる溶接作業を行わせるには、電極８にワ―クを当接させて、電動機１２を例えば反時計方向に回転させて電極８，１０を加圧動作させ、第３および第４ガンア―ムによる溶接作業が終了したならば、電動機１２を逆転させて電極８，１０を開放状態とすればよい。
【００２６】
そして、この実施例の場合には、第２ガンア―ム４に設けたロ―ラ３１を揺動レバ―１６の先端の溝３２内に移動可能に配置し、揺動レバ―１６の揺動時に減速機１４の出力軸３３とロ―ラ３１と連結部３とが同一直線上になる位置を、第１および第２ガンア―ムによる加圧位置と第３および第４ガンア―ムによる加圧位置のほぼ中間位置にすることにより、揺動レバ―１６が固定された減速機１４の出力軸３３の出力である電動機軸の出力と、前記揺動レバ―１６の先端からロ―ラ３１を介して電極５又は電極１０に伝達される電極加圧力とはほぼ比例してほぼ線形関係にあるので、電極２，５，８，１０等の摩耗やガンア―ム１，４，７，９等の撓み量の変化や各軸受の摩耗等によっても電極加圧力が影響を受けることが少ない。しかも、第２ガンア―ム４や第４ガンア―ム９の変位角度と揺動レバ―１６の変化角度がほぼ直線的な比例関係にあるので、電極摩耗による電極位置補正や第２ガンア―ム４や第４ガンア―ム９の開放角度の制御も極めて容易である。
【００２７】
なお、この実施例の場合、第２ガンア―ム４の後部上方にロ―ラ３１を取付け、揺動レバ―１６の先端に溝３２を形成して前記ロ―ラ３１を溝３２の内周に沿って移動可能としたが、第２ガンア―ム４の後部上方に溝を形成し、揺動レバ―１６の先端にロ―ラを取付けて該ロ―ラを前記溝の内周に沿って移動可能としても、実質的にほぼ同様の動作を行うものである。
【００２８】
次に図５に示す実施例について説明をする。なお、この場合も前の実施例と実質的に同一部材については同一符号を付してその説明を省略することがある。
図において、４１は第２ガンア―ム４の後端部に取付けられたギヤであり、また４２は揺動レバ―１６の先端に形成されたギヤ（減速機１４の出力軸３３に固定されたギヤ）であり、両ギヤ４１，４２は相互に噛合い状態にある。
【００２９】
上記のような構成からなる電動ガンにおいても、電動機の正逆交互に回転により、減速機１４の出力軸３３に固定されたギヤ４２によって第２ガンア―ム４および第４ガンア―ム９の開放動作或は加圧動作を行わせることができる。そして、両ギヤ４１，４２の噛合い箇所が軸３３と連結部３を結ぶ直線上にほぼ位置していることから、直前の実施例と実質的にほぼ同様の動作を行うものである。
【００３０】
【発明の効果】
本発明に係る電動ガンは、上述のように、請求項１の発明においては、それぞれ先端に電極を有する第１ないし第４ガンア―ムを備え、第１ガンア―ムの電極を第２ガンア―ムの電極と、第３ガンア―ムの電極を第４ガンア―ムの電極とそれぞれ相対向させて２セットの電動ガンとし、第１及び第３ガンア―ムを固定ア―ムとし、第２及び第４ガンア―ムを可動ア―ムとして、電動機の駆動により減速機を介して前記両可動ア―ムの電極に対して、一方の電極が加圧動作時に他方の電極に開放動作を行わせると共に電動機の正転時と逆転時のトルクと回転角度を自由に変え得るようにしたので、第１および第２ガンア―ムを用いた溶接と、第３および第４ガンア―ムを用いた溶接は、それぞれ独立してワ―クに最適な加圧力および開放ストロ―クを選定することができる電動ガンである。
また、請求項２ないし５の発明においても、先端に相対向する電極を備えた第１および第２ガンア―ムを軸支してなるＸ型電動溶接機の第１ガンア―ムから分岐した第３ガンア―ムを形成すると共に、前記第２ガンア―ムから延長した又は連結部に独立して回動自在に軸支した第４ガンア―ムを形成し、第３ガンア―ムの先端に設けた電極に第４ガンア―ムの先端に設けた電極を対向させ、前記第１および第２ガンア―ムの連結部より後方に配置した電動機の出力軸に減速機を接続し、該減速機の出力側に設けた動力伝達機構により前記第２および第４ガンア―ムを回動させるようにし、且つ第１および第２ガンア―ムの加圧動作時に第３および第４ガンア―ムが開放動作を行うようにしたので、該電動ガンにおいては電動機の正転時と逆転時のトルクと回転角度を自由に変えることが可能であり、第１および第２ガンア―ムを用いた溶接と、第３および第４ガンア―ムを用いた溶接は、それぞれ独立してワ―クに最適な加圧力および開放ストロ―クを選定することができる電動ガンである。
【００３１】
また、請求項２ないし５の発明においては、比較的に直径の大きな減速機をガンア―ムの連結部より後方に配置したため、従来例のようなガンア―ムの有効懐深さが小さくなることもなく、大きなワ―クへのガンの適用が可能となる電動ガンでありながら、電動機軸のトルクと、電極に伝達される電極加圧力とがほぼ線形関係にあるようにしたので、簡単な制御で設定した加圧力に対して正確な電極加圧力が得られ、しかも電極の摩耗やガンア―ムの撓み量の変化や各軸受の摩耗等によっても、電極加圧力が影響を受けることがない。また、ガンア―ムの変位角度と電動機の回転数も一次関数的に比例しているので、位置の制御も容易な電動ガンである。
【図面の簡単な説明】
【図１】図１は本発明に係る電動ガンの側面図である。
【図２】図２はその平面図である。
【図３】図３は本発明に係る電動ガンの他の実施例の側面図である。
【図４】図４は更に他の実施例の側面図である。
【図５】図５は更にまた他の実施例の側面図である。
【符号の説明】
１第１ガンア―ム
２，５，８，１０電極
３連結部
４第２ガンア―ム
６，６ａ，６ｂリンク
７第３ガンア―ム
９第４ガンア―ム
１２電動機
１３電動機の出力軸
１４減速機
１６揺動レバ―
３１ロ―ラ
３２溝
４１，４２ギヤ[0001]
BACKGROUND OF THE INVENTION
The present invention forms a third gun arm that branches from the first gun arm of an X-type electric welding machine that pivotally supports first and second gun arms having electrodes opposed to each other at the tip. A fourth gun arm extending from the second gun arm or pivotally supported independently of the connecting portion is formed, and the fourth gun arm is formed on the electrode provided at the tip of the third gun arm. A power transmission mechanism provided on the output side of the speed reducer, with a reduction gear connected to the output shaft of the electric motor arranged opposite to the electrode provided at the tip of the motor and disposed behind the connecting portion of the first and second gun arms In particular, the present invention relates to an electric gun in which the second and fourth gun arms are rotated.
[0002]
[Prior art]
Conventionally, a third gun arm branched from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms having electrodes opposed to each other at the tip is formed. A fourth gun arm extended from the second gun arm is formed, and the electrode provided at the tip of the fourth gun arm is opposed to the electrode provided at the tip of the third gun arm, and the piston rod of the air cylinder is used. A welding gun (hereinafter referred to as the former) in which the second and fourth gun arms are rotated is known (see, for example, Japanese Utility Model Publication No. 52-44582).
[0003]
In addition, in the X-type electric gun, in order to reduce the servo motor capacity and obtain a high applied pressure, the gun bracket is pivotally supported with respect to the first gun arm integrated with the gun bracket. An output disc fixed to the output side of the speed reducer via a servo motor and a speed reducer, a pin provided at a position near the outer periphery of the output disc, the pin, and the second gun arm -There is one that is pressurized by a crank mechanism (pressurizing mechanism) constituted by a connector arm (link) provided to connect the rear ends of the arms (hereinafter referred to as the latter). (See Kaihei 9-248678).
[0004]
[Problems to be solved by the invention]
By the way, the known former welding gun has a problem that it is difficult to adjust the applied pressure and the open stroke because the piston rod from the air cylinder is used for driving the gun arm.
[0005]
Further, in the known latter gun arm rotating means, in order to keep the servo motor capacity small, it is provided at the center of the output disk through the speed reducer and the position near the outer periphery of the disk. Using a so-called toggle mechanism, pressurization is performed at a position just before the angle between the line connecting the center of the pin and the rear end of the second gun arm and the ring connecting the pin is 180 degrees. Thus, the pressurizing force is increased. However, in such a pressurizing means, the degree of change in the applied pressure with respect to the amount of change in the rotation angle of the disk is large due to the relationship of the link output with respect to the rotation torque of the disk. However, as the angle approaches 180 degrees, it changes exponentially, and the electrode pressure changes greatly with a slight change in the angle between the pin and the link. In actual use of the welding machine, in addition to the change in the amount of wear of the electrodes, the amount of deflection of the arm changes for each applied pressure and the change in the aged wear of each support pin bearing including the main shaft part. It is difficult to obtain a stable angle by changing the angle. Therefore, from the characteristic of the toggle mechanism in which the applied pressure changes exponentially with respect to the amount of change in the rotation angle of the disc, the known technique is controlled so as to obtain an accurate applied pressure that matches the set pressure value. There is a problem that it is extremely difficult.
[0006]
The present invention has been made in view of such problems of the prior art, and an object thereof is to provide an electric gun having two sets of electrodes having first to fourth gun arms. It is extremely easy to adjust the applied pressure and open stroke in each set, and the electrode applied pressure is not affected by electrode or bearing wear or gun arm deflection that changes with each applied pressure. Thus, an electric gun is intended to output an accurate pressurizing force with respect to the pressurizing force set by simple control and obtain a stable pressurizing force.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the electric gun according to the present invention includes first to fourth gun arms each having an electrode at the tip, and the electrodes of the first gun arm and the electrodes of the second gun arm, The 3 gun arm electrodes are opposite to the 4 gun arm electrodes to form 2 sets of electric guns, the 1st and 3rd gun arms are fixed arms, and the 2nd and 4th gun arms. the movable a - as a beam, said via a reduction gear driven by the electric motor both movable a - positive motor with respect to beam of electrodes, one electrode to perform the opening operation to the other electrode during the pressurizing operation The torque and rotation angle at the time of rotation and reverse rotation can be freely changed.
And forming a third gun arm branched from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms having electrodes opposed to each other at the tip, A fourth gun arm extending from the second gun arm is formed, and an electrode provided at the tip of the fourth gun arm is opposed to an electrode provided at the tip of the third gun arm, so that the first and second A reduction gear fixed to the gun bracket is connected to the output shaft of the electric motor arranged behind the connecting portion of the gun arm, and the second and fourth gun arms are connected by a power transmission mechanism provided on the output side of the reduction gear. The power transmission mechanism includes a swinging lever fixed to the output side of the speed reducer, and a link formed between the lever and the second gun arm or the fourth gun arm. It consists of, the swing lever - and the link was fixed link the gun bracket URN a configuration personnel parallel four-link, the torque of the motor shaft, the swing lever - electrode pressurizing force and the swing lever such that a substantially linear relationship to be transmitted to the electrode through the link from the tip - and connecting the link and the first and second Gan'a - the torque and angle of rotation of the reverse rotation and forward rotation of the motor together with the beam causes I rows opening operation - the third and fourth Gan'a when no pressurized operation It is characterized by being able to change freely .
[0008]
And forming a third gun arm branched from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms having electrodes opposed to each other at the tip, A fourth gun arm extending from the second gun arm is formed, and an electrode provided at the tip of the fourth gun arm is opposed to an electrode provided at the tip of the third gun arm, so that the first and second A reduction gear fixed to the gun bracket is connected to the output shaft of the electric motor arranged behind the connecting portion of the gun arm, and the second and fourth gun arms are connected by a power transmission mechanism provided on the output side of the reduction gear. The power transmission mechanism includes a swinging lever fixed to the output side of the speed reducer, and a link formed between the lever and the second gun arm or the fourth gun arm. It consists of, the swing lever - and the link was fixed link the gun bracket URN a configuration personnel parallel four-link, the torque of the motor shaft, the swing lever - electrode pressurizing force and the swing lever such that a substantially linear relationship to be transmitted to the electrode through the link from the tip - and connecting the link and the first and second Gan'a - the torque and angle of rotation of the reverse rotation and forward rotation of the motor together with the beam causes I rows opening operation - the third and fourth Gan'a when no pressurized operation It is characterized by being able to change freely .
[0009]
And forming a third gun arm branched from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms having electrodes opposed to each other at the tip, A fourth gun arm extending from the second gun arm is formed, and an electrode provided at the tip of the fourth gun arm is opposed to an electrode provided at the tip of the third gun arm, so that the first and second A reduction gear is connected to the output shaft of the electric motor disposed behind the gun arm connecting portion, and the second and fourth gun arms are rotated by a power transmission mechanism provided on the output side of the reduction gear. The power transmission mechanism includes a swinging lever fixed to the output side of the speed reducer, a groove or roller provided in the swinging lever, and a roller provided in the second gun arm. It consists of a groove, the swing lever - an output shaft of the reduction gear during swing and Hollow - La and the connecting portion and is collinear to The that position, the first and second Gan'a - pressure position by arm and the third and fourth Gan'a - in almost middle position of the pressing position by the arm, and the torque of the motor shaft, the swing lever - from the tip The roller or groove provided with the tip of the swing lever on the second gun arm is swung so that the electrode pressing force transmitted to the electrode through the roller or groove is in a substantially linear relationship. lever - the tip of the groove or b - connected to La, and the first and second Gan'a - and the forward rotation of the motor together with the beam causes I rows opening operation - the third and fourth Gan'a arm is at pressure operation The torque and the rotation angle at the time of reverse rotation can be freely changed .
[0010]
And forming a third gun arm branched from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms having electrodes opposed to each other at the tip, A fourth gun arm extending from the second gun arm is formed, and an electrode provided at the tip of the fourth gun arm is opposed to an electrode provided at the tip of the third gun arm, so that the first and second A reduction gear is connected to the output shaft of the electric motor disposed behind the gun arm connecting portion, and the second and fourth gun arms are rotated by a power transmission mechanism provided on the output side of the reduction gear. The power transmission mechanism is composed of a gear fixed to the output side of the speed reducer and a gear provided in the second gun arm, and the meshing portion of both gears is connected to the output shaft of the speed reducer and the connecting portion. is substantially located on the straight line connecting the torque of the motor shaft, the output of the speed reducer The gear fixed to the output side of the speed reducer and the second gun arm so that the electrode pressurization transmitted to the electrode from the gear fixed to the second gun arm via the gear provided to the second gun arm has a substantially linear relationship. - engaging a gear provided on the arm, and first and second Gan'a - third and fourth Gan'a arm is at pressure operation - reverse rotation and forward rotation of the motor together with the beam causes I rows opening operation The torque and the rotation angle of can be freely changed .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the accompanying drawings.
1 is a side view of an electric gun according to the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a side view of another embodiment of the electric gun according to the present invention, and FIG. 4 is a side view of still another embodiment. FIG. 5 is a side view of still another embodiment. In each figure, the secondary current circuit and the like are not shown.
[0012]
1 and 2, reference numeral 1 denotes a fixed gun arm which constitutes a first gun arm according to the present invention, which is provided with an electrode 2 at the front end and a connecting portion 3 having a pivot at the rear end. It is fixed to. Reference numeral 4 denotes a movable gun arm, which constitutes the second gun arm in the present invention, and is provided with an electrode 5 facing the electrode 2 at the tip and a link 6 connected to the middle upper part. The rear end is pivotally supported by the connecting portion 3 comprising the pivot shaft. The first gun arm 1 and the second gun arm 4 constitute an X-type electric welding machine. A third gun arm 7 as a fixed gun arm is branched downward from the middle of the first gun arm 1, and an electrode 8 is provided at the tip of the third gun arm 7, and the second gun arm 7 is further provided with the second gun arm 7. A fourth gun arm 9 as a movable gun arm is extended from the connecting portion 3 at the rear end of the gun arm 4, and an electrode 10 facing the electrode 8 is provided at the tip of the fourth gun arm 9. ing.
[0013]
Reference numeral 11 denotes a gun bracket. A connecting portion 3 comprising the pivot is formed at the tip of the gun bracket 11, and the rear end is connected to a wrist of a robot (not shown). An electric motor 12 is attached to the middle upper portion of the gun bracket 11, and the output shaft 13 of the electric motor 12 and the speed reducer 14 disposed in the gun bracket 11 are connected by, for example, a belt transmission device 15.
[0014]
A rocking lever 16 made of a plate is fixed to the output side of the speed reducer 14. One end of the link 6 is pivoted at the middle upper portion of the second gun arm 4, and the other end of the link 6 is pivoted at the tip of the swinging lever 16. A power transmission mechanism is formed by the gun bracket 11 between the center point 19 of the swing lever 16 and the connecting portion 3, the swing lever 16, the link 6, and the arm 4 between the shaft 17 and the connecting portion 3. Forms a substantially parallel four-bar link with the gun bracket 11 as a fixed node. Reference numeral 20 denotes a welding machine transformer attached to the rear portion of the gun bracket 11.
[0015]
In the electric gun having the above-described configuration, the electric motor 12 rotates alternately forward and reverse. Then, as shown in FIG. 1, if welding is finished in a state where the upper and lower electrodes 2 and 5 are in contact with and pressed against the work 21 (the electrodes 8 and 10 are in an open state at this time), For example, when the electric motor 12 is rotated in the clockwise direction, the rotation is decelerated by the speed reducer 14 and the swing lever 16 is rotated in the clockwise direction. The second gun arm 4 is pulled by the link 6 to perform the opening operation. (At this time, the electrodes 8 and 10 enter the pressurizing operation). When the first and second gun arms are open, the electric gun is moved by the robot and guided to the next work, and the electric motor 12 is reversed with the lower electrode 2 in contact with the work. Let This rotation is decelerated by the speed reducer 14 to rotate the swing lever 16 counterclockwise, and the second gun arm 4 is pushed by the link 6 to perform a pressurizing operation (at this time, the electrodes 8, 10). 1 performs the welding operation by returning to the state shown in FIG. 1 (the above operation is performed by the first and second gun arms, and the third and fourth gun arms are not performed). Is an explanation of the case).
[0016]
In order to perform the welding operation by the third and fourth gun arms from the state shown in FIG. 1, the work is brought into contact with the electrode 8 and the electric motor 12 is rotated, for example, in the clockwise direction, so that the electrodes 8, 10 When the welding operation using the third and fourth gun arms is completed, the motors 12 may be reversed to open the electrodes 8 and 10.
[0017]
As described above, in the electric gun, after the rapid rotation of the electric motor 12 is decelerated by the speed reducer 14, the second gun arm 4 and the fourth gun arm 9 are moved via the swing lever 16 and the link 6. Since the motor is released or pressurized, the inertia moment value in terms of the shaft of the electric motor 12 is reduced. As a result, the acceleration / deceleration time when opening and closing the electrode of the electric gun is shortened, and shortening of the welding spot speed is effective. It can be hoped for. Further, after the output is amplified by the speed reducer 14, the second gun arm 4 and the fourth gun arm 9 are operated to open or pressurize via the swing lever 16 and the link 6; Since the welding force is less likely to vary and desired welding can be performed, and the reduction gear 14 having a relatively large diameter is disposed behind the connecting portion 3 of the gun arms 1 and 4, the gun arm as in the conventional example is used. The effective depth of the system is not reduced, and the gun can be applied to a large work. Further, since the torque and amount of rotation at the time of forward rotation and reverse rotation of the electric motor 12 can be freely changed, welding by the electrodes 2 and 5 and welding by the electrodes 8 and 10 are each optimal for the work. It is possible to select an appropriate pressure and open stroke.
[0018]
As described above, since the power transmission mechanism is a swinging lever 16 and the link 6 is a constituent member of a substantially parallel four-joint link having the gun bracket 11 as a fixed joint, the swinging lever 16 is fixed. The output of the motor shaft 13 which is the output of the output shaft of the reduction gear 14 and the electrode pressurizing force transmitted from the tip of the swing lever 16 to the electrodes 5 and 10 via the link 6 are approximately linear. Since there is a relationship, an accurate pressure can be obtained with respect to the pressure set by simple control. In addition, since the displacement angle of the second gun arm 4 and the fourth gun arm 9 and the change angle of the swing lever 16 are the same angle, the electrode position correction due to electrode wear and the second gun arm 4 and the fourth gun arm 4 Control of the opening angle of the gun arm 9 is extremely easy.
[0019]
In the above embodiment, the link 6 is provided between the swinging lever 16 and the second gun arm 4. However, the link 6 has the swinging lever 16 and the fourth gun arm 4. Even if it is provided between 9, the same operation is performed.
[0020]
Next, the embodiment shown in FIG. 3 will be described. This embodiment is substantially the same as the previous embodiment except that two link joints are provided on the swing lever 16 and the links are joined to the second gun arm 4 and the fourth gun arm 9, respectively. Therefore, substantially the same members may be denoted by the same reference numerals and the description thereof may be omitted. In the figure, the swing lever 16 is formed so as to have link joints at the top and bottom thereof. One end of the link 6 a is pivoted at the middle upper part of the second gun arm 4, and the other end of the link 6 a is pivoted at the link joint at the upper part of the swing lever 16. Further, one end of the link 6b is pivotally connected to the fourth gun arm 9 and the other end of the link 6b is pivotally connected to the lower link joint of the swing lever 16.
[0021]
Therefore, in this embodiment, the links 6a and 6b cooperate to reliably open and close the second gun arm 4 and the fourth gun arm 9.
The fourth gun arm 9 may be rotatable independently of the connecting portion without extending from the second gun arm 4. In this case, the second gun arm 4 is connected by the link 6a. The fourth gun arm 9 is opened and closed by the link 6b.
[0022]
Next, the embodiment shown in FIG. 4 will be described. In this case, members that are substantially the same as those in the previous embodiment may be given the same reference numerals and explanation thereof may be omitted.
In the figure, reference numeral 31 denotes a roller mounted on the rear upper part of the second gun arm 4, and a groove 32 is formed at the tip of the swing lever 16, and the roller 31 is formed in the groove 32. It is possible to move along the inner circumference.
[0023]
The gun bracket 11 has a welding machine transformer 20 attached thereto, and the welding machine transformer 20 holds a speed reducer 14 connected to the output shaft of the electric motor.
[0024]
In the electric gun configured as described above, as shown in FIG. 4, the upper and lower electrodes 2 and 5 are in contact with and pressed against the work 21 (at this time, the electrodes 8 and 10 are in an open state). ), When the electric motor is rotated counterclockwise, the rotation is decelerated by the speed reducer 14 and the swing lever 16 is rotated counterclockwise. The second gun arm 4 The opening operation is performed by being pulled by the swing lever 16 through the roller 31 (at this time, the electrodes 8 and 10 enter the pressurizing operation). The gun is moved by the robot in an open state and guided to the next work, and the motor is reversed with the lower electrode 2 in contact with the work. This rotation is decelerated by the speed reducer 14 to rotate the swinging lever 16 in the clockwise direction, and the second gun arm 4 is pushed by the swinging lever 16 through the roller 31 to perform the pressurizing operation. (At this time, the electrodes 8 and 10 are opened), returning to the state shown in FIG. The roller 31 can move along the inner periphery of the groove 32 formed in the swing lever 16 when the second gun arm 4 is opened and pressurized. There is no unreasonable force. (The above is a description of the case where the welding operation is performed by the first and second gun arms and the welding operation by the third and fourth gun arms is not performed).
[0025]
Then, in order to perform the welding operation by the third and fourth gun arms from the state of FIG. 4, the work is brought into contact with the electrode 8 and the electric motor 12 is rotated, for example, counterclockwise, so that the electrodes 8, When the welding operation by the third and fourth gun arms is completed by pressurizing 10, the motors 12 may be reversed to open the electrodes 8 and 10.
[0026]
In this embodiment, the roller 31 provided on the second gun arm 4 is movably disposed in the groove 32 at the tip of the swing lever 16 so that the swing lever 16 can be swung. Sometimes the position where the output shaft 33, the roller 31 and the connecting portion 3 of the speed reducer 14 are on the same straight line is determined by the pressurization position by the first and second gun arms and the addition by the third and fourth gun arms. By setting the pressure position substantially in the middle, the output of the motor shaft, which is the output of the output shaft 33 of the speed reducer 14 to which the swing lever 16 is fixed, and the roller 31 from the tip of the swing lever 16 are provided. Since the electrode pressurizing force transmitted to the electrode 5 or the electrode 10 via the electrode is substantially proportional to the linear relationship, the wear of the electrodes 2, 5, 8, 10 etc. and the gun arm 1, 4, 7, 9 The electrode pressing force is less affected by changes in the amount of deflection such as wear and wear of each bearing. In addition, since the displacement angle of the second gun arm 4 and the fourth gun arm 9 and the change angle of the swing lever 16 are in a substantially linear proportional relationship, the electrode position correction due to electrode wear and the second gun arm It is very easy to control the opening angle of the fourth gun arm 4 and the fourth gun arm 9.
[0027]
In this embodiment, a roller 31 is mounted above the rear part of the second gun arm 4 and a groove 32 is formed at the tip of the swinging lever 16 so that the roller 31 is attached to the inner periphery of the groove 32. However, a groove is formed above the rear part of the second gun arm 4, and a roller is attached to the tip of the swing lever 16, so that the roller runs along the inner periphery of the groove. Even if it is movable, substantially the same operation is performed.
[0028]
Next, the embodiment shown in FIG. 5 will be described. In this case, members that are substantially the same as those in the previous embodiment may be assigned the same reference numerals and explanation thereof may be omitted.
In the figure, 41 is a gear attached to the rear end portion of the second gun arm 4, and 42 is a gear formed at the tip of the swing lever 16 (fixed to the output shaft 33 of the speed reducer 14). The gears 41 and 42 are in mesh with each other.
[0029]
Even in the electric gun having the above-described configuration, the second gun arm 4 and the fourth gun arm 9 are opened by the gear 42 fixed to the output shaft 33 of the speed reducer 14 by alternately rotating the motor forward and backward. Operation or pressurization operation can be performed. And since the meshing location of both the gears 41 and 42 is located substantially on the straight line which connects the axis | shaft 33 and the connection part 3, operation | movement substantially the same as the last Example is performed.
[0030]
【The invention's effect】
Electric gun according to the present invention, as described above, in the invention of claim 1, each of the first to fourth Gan'a having electrodes on the tip - with the arm, first Gan'a - the arm of the electrode second Gan'a - The second electrode and the third gun arm are opposed to the fourth gun arm electrode to form two sets of electric guns, the first and third gun arms are fixed arms, and fourth Gan'a - moving the arm a - as a beam, said via a reduction gear driven by the electric motor two movable a - relative to arm electrode, the opening operation to the other electrode when one of the electrodes is pressurized operation Since the torque and rotation angle during forward and reverse rotation of the motor can be changed freely, welding using the first and second gun arms and the third and fourth gun arms are used. Welding was performed independently for each workpiece. An electric gun can be selected click.
Further, in the inventions of claims 2 to 5 , the first branching from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms each having an electrode opposed to the tip. A third gun arm is formed, and a fourth gun arm extending from the second gun arm or pivotally supported independently of the connecting portion is formed and provided at the tip of the third gun arm. The electrode provided at the tip of the fourth gun arm is opposed to the connected electrode, and a reduction gear is connected to the output shaft of the electric motor disposed behind the connecting portion of the first and second gun arms. The second and fourth gun arms are rotated by a power transmission mechanism provided on the output side, and the third and fourth gun arms are opened during the pressurizing operation of the first and second gun arms. In the electric gun, the electric gun rotates in reverse and forward It is possible to vary the the torque rotational angle freely, first and second Gan'a - welding and using beam, third and fourth Gan'a - welding using beam are each independently Wa - click It is an electric gun that can select the most suitable pressure and open stroke.
[0031]
Further, in the inventions of claims 2 to 5, since the reduction gear having a relatively large diameter is arranged behind the connecting portion of the gun arm, the effective depth of the gun arm as in the conventional example is reduced. In addition, although it is an electric gun that can be applied to a large work, the torque of the motor shaft and the electrode pressurizing force transmitted to the electrode are in a substantially linear relationship, so it is simple. Accurate electrode pressure can be obtained with respect to the pressure set by the control, and the electrode pressure is not affected by electrode wear, changes in gun arm deflection, or wear of each bearing. . Further, since the displacement angle of the gun arm and the rotational speed of the electric motor are proportional to each other in a linear function, the electric gun can be easily controlled in position.
[Brief description of the drawings]
FIG. 1 is a side view of an electric gun according to the present invention.
FIG. 2 is a plan view thereof.
FIG. 3 is a side view of another embodiment of the electric gun according to the present invention.
FIG. 4 is a side view of still another embodiment.
FIG. 5 is a side view of still another embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st gun arm 2, 5, 8, 10 Electrode 3 Connecting part 4 2nd gun arm 6, 6a, 6b Link 7 3rd gun arm 9 4th gun arm 12 Electric motor 13 Output shaft 14 of motor Deceleration Machine 16 Swing lever
31 Roller 32 Groove 41, 42 Gear

Claims

First to fourth gun arms each having an electrode at the tip are provided, the first gun arm electrode is the second gun arm electrode, the third gun arm electrode is the fourth gun arm electrode, and the like. Electric motors fixed to the gun bracket with two sets of electric guns facing each other, the first and third gun arms as fixed arms, and the second and fourth gun arms as movable arms A reduction gear is connected to the output shaft of the motor, and the output side of the reduction gear is connected to one of the movable arms via a swinging lever and a link. An electric gun characterized in that the other electrode performs an opening operation during the pressurizing operation, and the torque and rotation angle during forward and reverse rotation of the electric motor can be freely changed.

Forming a third gun arm branched from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms having electrodes opposed to each other at the tip; A fourth gun arm extending from the gun arm is formed, and an electrode provided at the tip of the fourth gun arm is opposed to an electrode provided at the tip of the third gun arm, so that the first and second gun arms are opposed to each other. A reduction gear fixed to the gun bracket is connected to the output shaft of the electric motor arranged behind the connecting portion of the motor, and the second and fourth gun arms are rotated by a power transmission mechanism provided on the output side of the reduction gear. The power transmission mechanism comprises a swinging lever fixed to the output side of the speed reducer and a link formed between the lever and the second gun arm or the fourth gun arm. the swing lever - link nearly was fixed link cancer bracket Rights A configuration personnel four-bar linkage, the torque of the motor shaft, the swing lever - tip transmitted to the electrode via a link from the electrode pressurizing force and the swing lever such that a substantially linear relationship - and links was ligated, and the first and second Gan'a - the torque and angle of rotation of the reverse rotation and forward rotation of the motor together with the beam causes I line open free to operate - the third and fourth Gan'a when no pressurized operation An electric gun that can be changed .

Forming a third gun arm branched from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms having electrodes opposed to each other at the tip; A fourth gun arm extended from the gun arm or pivotally supported independently of the connecting portion is formed, and an electrode provided at the tip of the third gun arm is provided at the tip of the fourth gun arm. The power transmission provided on the output side of the reduction gear is connected to a reduction gear fixed to the gun bracket to the output shaft of the electric motor disposed opposite to the connecting portion of the first and second gun arms. The mechanism is configured to rotate the second and fourth gun arms, and the power transmission mechanism is fixed to the output side of the speed reducer, and includes a swing lever having two link joints, Between one link joint and the second gun arm, and the other link joint and the fourth N'a - consists of a respective link formed between arm, the swing lever - link a configuration personnel substantially parallel four-link which is a fixed node cancer bracket, a torque of the motor shaft, said swing lever -The swing lever and each link are connected so that the electrode pressurizing force transmitted from the tip of the electrode to the electrode through each link has a substantially linear relationship, and the pressurizing operation of the first and second gun arms at the third and fourth Gan'a - AEG, characterized in that it has to be changed torque and rotation angle of the reverse rotation and forward rotation of the motor freely with arm causes I rows opening operation.

Forming a third gun arm branched from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms having electrodes opposed to each other at the tip; A fourth gun arm extending from the gun arm is formed, and an electrode provided at the tip of the fourth gun arm is opposed to an electrode provided at the tip of the third gun arm, so that the first and second gun arms are opposed to each other. A reduction gear is connected to the output shaft of the electric motor disposed behind the connecting portion of the motor, and the second and fourth gun arms are rotated by a power transmission mechanism provided on the output side of the reduction gear, The power transmission mechanism includes a swing lever fixed to the output side of the speed reducer, a groove or roller provided in the swing lever, and a roller or groove provided in the second gun arm. from it, the swing lever - output shaft b of the reduction gear when the swing of - La between positions in which the connecting portion is on the same line The first and second Gan'a - arm by pressing position and the third and fourth Gan'a - in almost middle position of the pressing position by the arm, and the torque of the motor shaft, the swing lever - tip Kararo - The roller or groove in which the tip of the swing lever is provided in the second gun arm so that the electrode pressing force transmitted to the electrode through the roller or groove has a substantially linear relationship. grooves or Hollow tip of - connecting to La, and the first and second Gan'a - third and fourth Gan'a arm is at pressure operation - forward during the reverse rotation of the motor together with the beam causes I rows opening operation An electric gun characterized in that the torque and rotation angle can be changed freely .

Forming a third gun arm branched from the first gun arm of the X-type electric welding machine that pivotally supports the first and second gun arms having electrodes opposed to each other at the tip; A fourth gun arm extending from the gun arm is formed, and an electrode provided at the tip of the fourth gun arm is opposed to an electrode provided at the tip of the third gun arm, so that the first and second gun arms are opposed to each other. A reduction gear is connected to the output shaft of the electric motor disposed behind the connecting portion of the motor, and the second and fourth gun arms are rotated by a power transmission mechanism provided on the output side of the reduction gear, The power transmission mechanism is composed of a gear fixed to the output side of the reduction gear and a gear provided on the second gun arm, and a straight line connecting the meshing portion of both gears with the output shaft of the reduction gear and the connecting portion. substantially is located above, and the torque of the motor shaft, the solid on the output side of the reduction gear The gear fixed to the output side of the speed reducer and the second gun arm so that the electrode pressurizing force transmitted to the electrode through the gear provided to the second gun arm from the formed gear has a substantially linear relationship meshing a gear provided in, and the first and second Gan'a - third and fourth Gan'a arm is at pressure operation - torque during reverse rotation and forward rotation of the motor together with the beam causes I rows opening operation An electric gun characterized in that the rotation angle can be freely changed .