JP3666846B2

JP3666846B2 - High pressure gas filling welding method

Info

Publication number: JP3666846B2
Application number: JP06727499A
Authority: JP
Inventors: 正二三平; 征一谷岡; 俊之高橋
Original assignee: 株式会社電元社製作所
Priority date: 1999-02-05
Filing date: 1999-02-05
Publication date: 2005-06-29
Anticipated expiration: 2019-02-05
Also published as: JP2000227199A

Description

【０００１】
【発明の属する利用分野】
本発明は自動車の安全用に搭載されるエアバックのボトル本体又は緩衝器のシリンダ本体等（以下ボトル本体という）の本体容器に，小さな高圧ガス注入孔を設けてその注入孔から高圧ガスを給入し，前記注入孔を溶接ピンで塞いでプロジェクション溶接して密封する高圧ガス充填溶接方法に関する。
【０００２】
【従来の技術】
従来一般に知られている高圧ガス充填溶接装置は，たとえば自動車に使用される緩衝器の場合は，ボトル本体をターンテーブル又はコンベヤー等により垂直状態にクランプし，順次溶接ステーションに移送し，高圧ガス注入孔より圧縮ガスを供給して，この高圧ガス注入孔に溶接ピンを挿入して後，そのボトル本体を押し上げ，シリンダの外周を割り電極で挟持し，その後ボトル本体を上部電極まで押し上げ，溶接ピンを加圧し電極に溶接電流を流して溶接ピンの頭部を高圧ガス注入孔にプロジェクション溶接して高圧ガスを前記ボトル本体内に密封する方式が知られている。
【０００３】
【発明が解決しようとする課題】
ボトル本体に高圧ガスを給入する場合，従来はメタルシールの先端刃先を高圧ガス注入部の平面に対し直角に押し当ててシールドするもので，一般にはボトル本体の断面形状が円形の場合は，メタルシールを高圧ガス注入孔のあるボトル本体側面に押し当ててシールドすることはできないので，高圧ガス注入孔近辺の側面を平滑に加工した後，その平面部にメタルシールを押し付けてガスシールドしていた。しかしながら，従来のこの種の方法は，パイプ状の側面を一部平坦に整形するための工数が掛かる分，効率が悪くコストアップの要因になっていた。
【０００４】
【発明の目的】
本発明は断面形状が円形体のボトル本体に対し効率的に高圧ガス充填を行うことができる生産性の高い溶接システムの実現に資することを目的とする。
【０００５】
【課題を解決するための手段】
本発明は上記の目的を達成するため，次のような技術的手段を講じてある。すなわち，請求項１の発明は，断面円形をなすボトル本体の側面に予め穿設された高圧ガス注入孔に，径が前記高圧ガス注入孔の径を塞ぐ大きさの頭部と径が前記高圧ガス注入孔の径より小さい軸栓と前記頭部に形成された高圧ガス流入溝とからなる溶接ピンを挿入し，前記溶接ピンを含む高圧ガス注入孔の周囲をシールド手段により局部的にシールドした後，前記シールドした空間に高圧ガスを注入して前記溶接ピンに形成された高圧ガス流入溝から高圧ガスを前記ボトル本体内に供給して所定の高圧ガス充填圧に達したときに前記シールド内に挿入された電極チップを動作させて前記溶接ピンの頭部を前記高圧ガス注入孔に押し付け，さらに前記電極チップを介して溶接に必要な加圧力と溶接電流を与えてプロジェクション溶接する高圧ガス充填溶接方法において，前記シールド手段は円筒体をなし，しかも前記シールド手段の円筒体の先端には刃先が形成され，前記刃先は前記ボトル本体側面の曲面形状に対応した形状をもって前記ボトル本体の側面の法線方向から前記ボトル本体側面に押し付けられるようになし，前記シールド内に注入される高圧ガスで前記溶接ピンを浮上する方向に付勢させるに際し，前記シールド内の電極チップと相対する前記溶接ピンの頭部との相互間に前記溶接ピンの浮上方向の高さを規制するためのスキ間ｅが設定され，それによって少なくとも前記溶接ピンの軸栓の一部が前記高圧ガス注入孔に差し込まれた状態で前記ボトル本体内に高圧ガスが注入され前記溶接動作で密封されるようにしたことを特徴とする高圧ガス充填溶接方法を提供する。
【０００６】
また請求項２の高圧ガス充填溶接方法は，前記シールド手段の円筒体の先端に形成された刃先の形状が鋭角を挟む辺の一方が傾斜していること又は鋭角を挟む両方の辺が傾斜していることを特徴とする。
【０００７】
また請求項３の高圧ガス充填溶接方法は，前記シールド手段の先端刃先を前記ボトル本体側面Ｒに食い込ませ，それによって前記高圧ガス注入孔周辺のシールドを行うことを特徴とする。
【０００８】
次の請求項４の高圧ガス充填溶接方法において，前記シールド手段のシールド加圧を二段加圧方式とし，その一段目の加圧力で前記シールド手段の先端刃先を前記ボトル本体の側面に食い込ませた後，高圧ガス注入過程において，前記ボトル本体の高圧ガス充填圧が，予め設定された高圧ガス充填圧に達したときに，前記一段目の加圧力よりもさらに上昇した二段目の加圧を行い，それによって板厚の薄いボトル本体のシールド性を向上させることを特徴とする。
【０００９】
こうすることによって，ボトル本体側面Ｒ及びボトル本体の板厚に関係無く直接高圧ガス注入孔にメタルシールの先端刃先を押し当てて，完全なシールド効果を得ることができ，高圧ガス注入効率と溶接品質を高める。
【００１０】
さらに請求項５の発明は，前記ボトル本体は下部クランプ電極と上部クランプ電極とを有する抵抗溶接機によりクランプ保持され，前記下部クランプ電極及び上部クランプ電極は，実質的にボトル本体の側面Ｒを支持する断面凹形のワーククランプ面とワーク給電面を兼ね備え，前記下部クランプ電極及び前記上部クランプ電極により溶接部近傍を含む前記ボトル本体の側面Ｒを強制的に拘束し，それによって，高圧ガス注入時及び／又は加圧溶接時に生じる前記ボトル本体の変形を防止するようにしたことを特徴とする。
【００１１】
【発明の実施の形態】
以下，本発明の好ましい実施例を図面に基づいて説明する。
図１は本発明の方法を実施するための高圧ガス充填溶接装置の概略を示す必要構成部の断面図である。図２は前記溶接装置の概略を示す正面図である。図３は溶接ピンの実施例を示す外観図である。
【００１２】
本発明の実施例では代表的な例としてエアバックに使用される高圧ガス充填ボトルの高圧ガス封入溶接法に関して説明する。
【００１３】
図１及び図２において，ボトル本体1は板厚が２ｍｍ程度のもので，断面形状が直径２５ｍｍ程度の円筒形軟鋼材から構成されている。前記ボトル本体はパイプの両側開口部１ａが気密に塞がれている。前記ボトル本体の側面Ｒには，予め直径３ｍｍ程度の小さな高圧ガス注入孔２が明けられている。前記ガス注入孔は実質的にパイプ壁を前記ボトル本体の軸心線に対し直角方向から貫通し，パイプ中空内に連通されている。
【００１４】
溶接ピン３は図３に示すように，高圧ガス注入孔に挿入される軸栓４と，高圧ガス注入孔を塞ぐ大きさの頭部５とを有するものである。前記頭部５に円すい形のテ―パ部が形成され，そのテーパ部の周囲に３本の突起Ｐが形成されていて，前記突起Ｐは集中的に加熱溶融されるプロジェクション溶接部と高圧ガスが容易にボトル内に入るように，つまり前記ガス注入孔２に溶接ピン３の軸栓４を挿入した状態で前記突起Ｐのスキ間からボトル内に高圧ガスを注入できるように，高圧ガス流入溝を兼ねている。
【００１５】
前記ボトル本体１は溶接機の下部クランプ電極６と上部クランプ電極７によりしっかりクランプ保持される。前記下部クランプ電極６及び上部クランプ電極７は，実質的にボトル本体１の側面Ｒと適合する断面凹形の曲面をもつワーククランプ面Ｕとワーク給電面を兼ね備えたもので，前記下部クランプ電極６を昇降シリンダ８により矢印方向にクランプないし開放動作を行い，ワークセット位置と高圧ガス注入・溶接基準位置との距離を上下動するものである。
【００１６】
なお，上記上下クランプ電極６，７は上下からそれぞれの駆動源で相互にクランプ駆動するようにしてもよい。
【００１７】
上部クランプ電極７は下部クランプ電極６に相対して配置され，図示しない抵抗溶接機の本体上部アーム側に支持されていて，前記ボトル本体１の高圧ガス注入孔２に対応する位置には開口部９が形成されていて，前記開口部９には前記シールド装置が挿入されるように構成されている。
【００１８】
前記シールド装置１０は，前記電極チップ１２の外径より大径の金属製円筒体のメタルシール１１から構成されていて，前記メタルシール１１は前記電極チップの外径より大きい内径の中空間ｂを有し，その中空間ｂと同心円上に挿入された棒状の電極チップ１２とが前記上部クランプ電極７の開口部９内に配置されている。
【００１９】
前記電極チップ１２と前記メタルシール１１とは絶縁された状態で同心的に重ねられており，前記電極チップ１２は加圧用アクチュエータ(図省略)により支持され前記メタルシール内を上下動する。上記メタルシール１１の内径と上記電極チップ１２の外周とはＯリング１３などで気密にシールされている。
【００２０】
前記上部クランプ電極７と電極チップ１２は溶接トランスＴからの二次回路に接続され，必要な溶接電流は前記ボトル本体内に高圧ガスが所定の高圧ガス充填圧に達するまで給入された後，前記電極チップ１２及び上部クランプ電極７を介して前記溶接ピン３に供給される。
【００２１】
前記メタルシール１１の開先は円筒状になっている。前記円筒状のシール先端には刃先が形成されている。この刃先の形状は鋭角Ｑをなすものである。刃先の形状は鋭角を挟む両方の辺が傾斜している断面Ｖ字形であるか又は鋭角を挟む辺の一方がそのメタルシールの外がわからその軸心線に向かって次第に傾斜したものである。その円形の刃先は前記ボトル本体側面Ｒの曲面形状に適合した形状に形成されている。これによって前記ボトル本体の側面の法線方向から前記刃先を前記ボトル本体側面に押し当てて食い込ませることで，前記メタルシール内に完全に外気と遮蔽された小容積のシールド空間１４が形成される。
【００２２】
とくに前記ボトル本体１の板厚が薄い場合は，二段加圧シリンダにより一段目のシールド加圧時にボトル本体が変形する場合があるので，注入時の高圧ガスによるボトル内圧の上昇と共にシールド先端刃先の一段目の加圧力をさらに上昇させた加圧力で二段目の加圧を行いよりシールド性を向上させる。
【００２３】
シールド空間１４には高圧ガス供給源１５からの高圧ガスが高圧ガス供給回路１６を経てメタルシール１１に設けられた高圧ガス供給口１７から供給される。
【００２４】
以下，本発明の方法を実施するための装置による高圧ガス注入／溶接動作を図４に基づいて説明する。
まず，前記ボトル本体1は昇降シリンダ８で戻しワークセット位置に待機している下部クランプ電極６にセットされる。そして下部クランプ電極６を上部クランプ電極７の溶接基準位置に上昇させ，これによりボトル本体が上下からクランプ保持される(図４Ａ)。
【００２５】
次いで，クランプ保持された前記ボトル本体１の高圧ガス注入孔２に溶接ピン３が挿入される。溶接ピンの挿入は手動又はパーツフイダ―で自動的に行われる(図４Ｂ)。
【００２６】
前記溶接ピン３がボトル本体１の高圧ガス注入孔２に挿入されると，前記シールド装置１０のメタルシール１１が加圧アクチュエータにより下降され，シール開先が溶接ピン３を含むガス給入孔周辺を包囲し外気から局部的に遮蔽することで，小容積のシールド空間１４が形成される(図4Ｃ)。
【００２７】
次に前記シールドされた前記密封空間１４に高圧ガス供給源１５からたとえば高圧ガス圧力４０Ｍｐａの高圧ガスが供給される(図４Ｄ)。
【００２８】
この場合，前記ボトル本体の板厚がたとえば２ｍｍ程度の薄いものに対しては，一段目のシールド加圧力は前記ボトル本体が変形しない１５ｋＮ程度の加圧力で行い，さらに高圧ガス注入過程中において，ボトル内の供給高圧ガスが所定のガス充填圧まで上昇したときに，二段目として前記メタルシール刃先のシールド加圧力を１７ｋＮに上昇させてよりシールド性を向上させる(図４Ｃ)。
【００２９】
前記シールドされた前記密封空間１４に供給された高圧ガスは，前記溶接ピン３が高圧ガス注入孔２に挿入されたまま突起Ｐより形成された僅かな隙間から容易にボトル本体内に供給される。
【００３０】
つまり前記メタルシール内の前記電極チップ１２の先端が溶接ピン３と非接触状態で対向し，前記チップ先端と溶接ピンの頭部５との間に若干のスキ間ｅが形成される。前記スキ間ｅは溶接ピン３の長さより短く設定され，これにより溶接ピン３が高圧ガス流により高圧ガス注入孔２から浮上しても，電極チップ先端で溶接ピン３の浮き揚がる高さが規制されることで溶接ピン３は高圧ガス注入孔２から抜けることなく嵌め込んだまま効率よく高圧ガス注入が行われる。
【００３１】
したがって，溶接ピン３は高圧ガス注入孔２から前記スキ間ｅ分のみ僅かに浮き揚がるだけで，その間，シールド室内に高圧ガスのみ供給される。この高圧ガス流は溶接ピンの突起Ｐによる高圧ガス流入溝からボトル容積の規定充填圧に達するまで供給される。
【００３２】
次いで，加圧アクチュエータを動作させて電極チップ１２を加圧駆動し溶接ピン３の頭部５を前記ボトル本体の高圧ガス注入孔２の縁周に押し付け，溶接に必要なたとえば２ｋＮから４ｋＮの電極加圧力と，たとえば電流値８０００Ａから１００００Ａの溶接電流を供給して溶接ピン３の頭部突起Ｐと高圧ガス注入孔２の縁周とを集中的に加熱溶融し高圧ガス封入溶接を完了する(図４Ｅ)。
【００３３】
上記動作過程中において，前記ボトル本体１がとくに薄板の場合は，高圧ガス注入時の高圧ガスの影響でボトル容積が膨張し，加圧溶接時の衝撃力や熱影響で撓みや曲率変形を受けようとするが，下部クランプ電極６と上部クランプ電極７とでボトル本体側面Rと同等の曲率を有するワーククランプ面Ｕにより溶接部を含むワーク側面全体を強制的に拘束ないし整形するため，ワーク変形をまったく受けることなく高圧ガス封入／溶接加工することができる。
【００３４】
以上のサイクルで溶接が終了すると，昇降シリンダ８が下降し，溶接された前記ボトル本体１は上下電極クランプから開放され，元のアンクランプ位置に戻され，そして搬出される。搬出された後の下部クランプ電極には次の新しボトル本体１が供給され，以下同様に溶接作業が繰り返し行われる
【００３５】
【発明の効果】
以上で説明したように，本発明の請求項１の方法によれば，ボトル本体に高圧ガスを封入する場合，従来は一旦その高圧ガス注入部近辺を平滑に加工した後，平滑面にメタルシールを押し当てて前記ボトル内に高圧ガスを充填して溶接していたのに対し，本願発明は断面円形をなすボトル本体の側面に形成された高圧ガス注入部に，予め溶接ピンを挿入して置き，その溶接ピンの周囲空間をシールドして，そのシールド空間に供給される高圧ガス流によって溶接ピンの頭部が浮上する方向に付勢されることしかも浮上方向に付勢された溶接ピンの位置規制をシールド内の電極チップと相対する高圧ガス注入部との間に設けた僅かなスキ間分で行うこと，それによって浮上する方向に付勢された状態で少なくとも溶接ピンの軸栓の一部が高圧ガス注入孔に差し込まれたまま高圧ガスがボトル本体内に注入されること。さらに前記ボトル本体の側面にシールド空間を形成するためのシールド手段が円筒体をなしその円筒体の先端には刃先が形成され当該刃先は前記ボトル本体側面の曲面形状に対応した形状を有し，しかも当該刃先を前記ボトル表面に押し付ける方向が，前記ボトル本体の側面の法線であり，これによってシールド装置の刃先が高圧ガス注入部を有するボトル本体側面Ｒの曲面形状に適合した状態で食い込み，直接高圧ガス注入に必要最小限の容積と完全な遮蔽空間を形成することができるのでその高圧ガス注入部位を従来のように平滑面の加工をせずに済み効率的に高圧ガス充填・溶接することができ，設備も簡単で設備投資のコストの問題も解決できる。
【００３６】
次の請求項２，３の発明によれば，前記シールド手段の先端刃先は鋭角を挟む両側の辺がＶ字状に傾斜した形状であるか又は鋭角を挟む一方の辺が円筒体の外がわから軸心線に向かって次第に傾斜した形状を有し，これにより前記シールド手段の先端刃先を前記ボトル本体の側面の法線方向から前記ボトル本体側面Ｒに押圧して容易に食い込ませることができ，高圧ガス注入部位に必要最小限の容積で飛躍的にシールド性を向上することができる。
【００３７】
また本発明の請求項４によれば，とくに前記ボトル本体の板厚が薄い場合に，二段加圧方式により一段目を前記ボトル本体が変形しない程度のシールド加圧力で加圧し，次いで二段目の加圧で前記ガス注入時の高圧ガスによるガス充填圧を上昇させると共にシールド加圧力を上昇させる。これにより前記メタルシールの先端刃先によるシールド性を向上させることができる。
【００３８】
次に，本発明の請求項５の方法によれば，上下クランプ電極により前記ボトル本体側面Ｒの曲面形状に適合した断面凹形のワーククランプ面で溶接部を含むワーク側面全体が強制的に拘束されるため，ボトル本体外形の変形をまったく受けないで整形加工することができる。
【００３９】
つまりボトル本体は高圧ガス注入時の高圧ガスの影響でボトル容積が膨張し加圧溶接時に衝撃力や熱影響を受けるが，クランプ電極による整形効果が得られ，これによって前記ボトル本体の変形を防止することができる。
【図面の簡単な説明】
【図１】本発明の方法を実施するための高圧ガス充填溶接装置の実施例を示す必要構成部の断面図である。
【図２】本発明の方法を実施するための前記装置の実施例を示す正面図である。
【図3】溶接ピンの一例を示す外観図である。
【図４】本発明方法による高圧ガス充填／溶接動作パターンを示す図である。
【符号の説明】
１ボトル本体
２高圧ガス注入孔
３溶接ピン
４軸栓
５頭部
６下部クランプ電極
７上部クランプ電極
８昇降シリンダ
９電極開口部
１０シールド装置
１１メタルシール
１２電極チップ
１３Ｏリング
１４シールド空間
１５高圧ガス供給源
１６高圧ガス供給回路
１７高圧ガス供給口
Ｐ突起
Ｑ鋭角
Ｒボトル本体側面
Ｔ溶接トランス
Ｕワーククランプ面[0001]
BACKGROUND OF THE INVENTION
In the present invention, a small high-pressure gas injection hole is provided in a main body container of an airbag bottle body or a cylinder body of a shock absorber (hereinafter referred to as a bottle body) mounted for safety of an automobile, and high-pressure gas is supplied from the injection hole. The present invention relates to a high-pressure gas-filled welding method in which the injection hole is closed with a welding pin , and is sealed by projection welding.
[0002]
[Prior art]
For example, in the case of a shock absorber used in an automobile, a high-pressure gas filling welding apparatus generally known in the art clamps the bottle body in a vertical state by a turntable or a conveyor, and sequentially transfers the bottle body to a welding station to inject high-pressure gas. After supplying compressed gas from the hole and inserting a welding pin into this high-pressure gas injection hole, the bottle body is pushed up, the outer periphery of the cylinder is clamped with a split electrode, and then the bottle body is pushed up to the upper electrode, and the welding pin There is known a system in which a welding current is passed through an electrode and a welding pin is projected to a high-pressure gas injection hole to seal the high-pressure gas in the bottle body.
[0003]
[Problems to be solved by the invention]
When supplying high-pressure gas to the bottle body, conventionally, the tip of the metal seal is pressed at a right angle to the plane of the high-pressure gas injection part and shielded. Generally, when the cross-sectional shape of the bottle body is circular, Since the metal seal cannot be pressed against the side of the bottle body with the high-pressure gas injection hole to shield it, after the side surface near the high-pressure gas injection hole is processed smoothly, the metal seal is pressed against the flat part to gas shield. It was. However, this type of conventional method is inefficient and increases costs because it takes time to shape the pipe-shaped side surface partially.
[0004]
OBJECT OF THE INVENTION
An object of the present invention is to contribute to the realization of a highly productive welding system capable of efficiently performing high-pressure gas filling on a bottle body having a circular cross-sectional shape.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention takes the following technical means. That is, according to the first aspect of the present invention, a high-pressure gas injection hole previously drilled in a side surface of a bottle body having a circular cross-section has a head having a diameter large enough to block the diameter of the high-pressure gas injection hole and the diameter of the high-pressure gas injection hole insert welding pins made of a high-pressure gas inlet groove formed in the head and smaller than the diameter shaft plug of the gas injection hole was locally shielded by shielding means around the high-pressure gas injection hole including the welded pin Thereafter, high-pressure gas is injected into the shielded space, and high-pressure gas is supplied into the bottle body from a high-pressure gas inflow groove formed in the welding pin . high pressure operates the inserted electrode tip pressed against the high-pressure gas injection hole of the head of the welding pin further projection welding giving pressure and the welding current required to weld through the electrode tip In the filling welding method, the shield means has a cylindrical body, and a cutting edge is formed at the tip of the cylindrical body of the shielding means, and the cutting edge has a shape corresponding to the curved shape of the side surface of the bottle body. The bottle is pressed against the side of the bottle body from the normal direction of the side, and the high pressure gas injected into the shield is used to urge the welding pin in the direction of rising so as to face the electrode tip in the shield. A gap e is set between the head of the welding pin and the height of the welding pin in the flying direction, whereby at least a part of the shaft plug of the welding pin is placed in the high-pressure gas injection hole. to provide a high pressure gas filling welding method high pressure gas inserted state in the bottle body, characterized in that it has to be injected is sealed by the welding operation .
[0006]
In the high-pressure gas-filled welding method according to claim 2, the shape of the cutting edge formed at the tip of the cylindrical body of the shield means is such that one of the sides sandwiching an acute angle is inclined or both sides sandwiching the acute angle are inclined. It is characterized by.
[0007]
The high-pressure gas filling welding method according to claim 3 is characterized in that the tip edge of the shield means bites into the bottle body side surface R, thereby shielding the periphery of the high-pressure gas injection hole.
[0008]
5. The high pressure gas filling welding method according to claim 4, wherein the shield pressurization of the shield means is a two-stage pressurization method, and the tip edge of the shield means is bitten into the side surface of the bottle body by the first pressurizing force. After that, during the high pressure gas injection process, when the high pressure gas filling pressure of the bottle body reaches a preset high pressure gas filling pressure, the second stage pressurization is further increased from the first stage pressurization pressure. It is characterized by improving the shielding performance of the thin bottle body.
[0009]
This makes it possible to obtain a complete shielding effect by directly pressing the tip of the metal seal against the high-pressure gas injection hole regardless of the side wall R of the bottle main body and the thickness of the bottle main body. Increase quality.
[0010]
Further, in the invention of claim 5, the bottle body is clamped and held by a resistance welding machine having a lower clamp electrode and an upper clamp electrode, and the lower clamp electrode and the upper clamp electrode substantially support the side surface R of the bottle body. A work clamping surface having a concave cross section and a workpiece feeding surface, and the side surface R of the bottle body including the vicinity of the welded portion is forcibly constrained by the lower clamp electrode and the upper clamp electrode. And / or deformation of the bottle body that occurs during pressure welding is prevented.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a necessary component showing an outline of a high-pressure gas-filled welding apparatus for carrying out the method of the present invention. FIG. 2 is a front view showing an outline of the welding apparatus. FIG. 3 is an external view showing an embodiment of a welding pin.
[0012]
In the embodiments of the present invention, a high pressure gas sealed welding method for a high pressure gas filled bottle used for an air bag will be described as a representative example.
[0013]
1 and 2, the bottle body 1 has a plate thickness of about 2 mm and is made of a cylindrical mild steel material having a cross-sectional shape of about 25 mm in diameter. The bottle body has airtightly closed openings 1a on both sides of the pipe. A small high-pressure gas injection hole 2 having a diameter of about 3 mm is previously opened on the side surface R of the bottle body. The gas injection hole substantially penetrates the pipe wall from a direction perpendicular to the axis of the bottle body and communicates with the inside of the pipe hollow.
[0014]
As shown in FIG. 3, the welding pin 3 has a shaft plug 4 to be inserted into the high-pressure gas injection hole and a head 5 having a size that closes the high-pressure gas injection hole. A conical taper portion is formed on the head portion 5, and three projections P are formed around the taper portion. The projection P is heated and melted in a concentrated manner, and a high pressure gas. So that the high pressure gas can be injected into the bottle through the gap of the projection P with the shaft plug 4 of the welding pin 3 inserted into the gas injection hole 2. Also serves as a groove.
[0015]
The bottle body 1 is firmly clamped and held by the lower clamp electrode 6 and the upper clamp electrode 7 of the welding machine. The lower clamp electrode 6 and the upper clamp electrode 7 have both a workpiece clamping surface U having a concave curved surface and a workpiece feeding surface that substantially match the side surface R of the bottle body 1. Is lifted or lowered in the direction of the arrow by the elevating cylinder 8, and the distance between the work set position and the high pressure gas injection / welding reference position is moved up and down.
[0016]
Note that the upper and lower clamp electrodes 6 and 7 may be driven to be clamped with each other from the upper and lower sides.
[0017]
The upper clamp electrode 7 is disposed relative to the lower clamp electrode 6 and is supported on the upper arm side of the main body of a resistance welder (not shown), and has an opening at a position corresponding to the high-pressure gas injection hole 2 of the bottle main body 1. 9 is formed, and the shield device is inserted into the opening 9.
[0018]
The shield device 10 is composed of a metal seal 11 made of a metal cylinder having a diameter larger than the outer diameter of the electrode tip 12, and the metal seal 11 has a medium space b having an inner diameter larger than the outer diameter of the electrode tip. The inner space b and a rod-shaped electrode tip 12 inserted concentrically are arranged in the opening 9 of the upper clamp electrode 7.
[0019]
The electrode tip 12 and the metal seal 11 are concentrically stacked in an insulated state, and the electrode tip 12 is supported by a pressurizing actuator (not shown) and moves up and down in the metal seal. The inner diameter of the metal seal 11 and the outer periphery of the electrode tip 12 are hermetically sealed by an O-ring 13 or the like.
[0020]
The upper clamp electrode 7 and the electrode tip 12 are connected to a secondary circuit from a welding transformer T, and a necessary welding current is supplied until high pressure gas reaches a predetermined high pressure gas filling pressure in the bottle body. The welding pin 3 is supplied via the electrode tip 12 and the upper clamp electrode 7.
[0021]
The groove of the metal seal 11 has a cylindrical shape. A blade edge is formed at the end of the cylindrical seal. The shape of the cutting edge forms an acute angle Q. The shape of the cutting edge is a V-shaped cross section in which both sides sandwiching an acute angle are inclined, or one of the sides sandwiching the acute angle is gradually inclined from the outer side of the metal seal toward the axis. The circular cutting edge is formed in a shape suitable for the curved surface shape of the bottle body side surface R. As a result, the blade edge is pressed against the side surface of the bottle body from the normal direction of the side surface of the bottle body, and a small volume shield space 14 completely shielded from outside air is formed in the metal seal. .
[0022]
In particular, when the thickness of the bottle body 1 is thin, the bottle body may be deformed when the first stage of the shield is pressed by the two-stage pressurizing cylinder. The shielding performance is further improved by applying the second-stage pressurization with a further increase in the first-stage applied pressure .
[0023]
The shield space 14 is supplied with high-pressure gas from a high-pressure gas supply source 15 through a high-pressure gas supply circuit 16 through a high-pressure gas supply port 17 provided in the metal seal 11.
[0024]
Hereinafter, the high-pressure gas injection / welding operation by the apparatus for carrying out the method of the present invention will be described with reference to FIG.
First, the bottle body 1 is set on the lower clamp electrode 6 waiting at the return work setting position by the elevating cylinder 8. Then, the lower clamp electrode 6 is raised to the welding reference position of the upper clamp electrode 7, and the bottle body is clamped and held from above and below (FIG. 4A).
[0025]
Next, a welding pin 3 is inserted into the high-pressure gas injection hole 2 of the bottle body 1 held by the clamp. The welding pin is inserted manually or automatically by a parts feeder (FIG. 4B).
[0026]
When the welding pin 3 is inserted into the high-pressure gas injection hole 2 of the bottle body 1, the metal seal 11 of the shield device 10 is lowered by the pressure actuator, and the seal groove is around the gas supply hole including the welding pin 3. And a small shield space 14 is formed (FIG. 4C).
[0027]
Next, a high-pressure gas having a high-pressure gas pressure of 40 MPa is supplied from the high-pressure gas supply source 15 to the shielded sealed space 14 (FIG. 4D).
[0028]
In this case, when the thickness of the bottle main body is as thin as about 2 mm, for example, the first stage shield pressure is about 15 kN which does not deform the bottle main body. When the supply high-pressure gas in the bottle rises to a predetermined gas filling pressure, the shield pressure is further improved by raising the shield pressure of the metal seal blade edge to 17 kN as the second stage (FIG. 4C).
[0029]
The high-pressure gas supplied to the shielded sealed space 14 is easily supplied into the bottle body through a slight gap formed by the protrusion P while the welding pin 3 is inserted into the high-pressure gas injection hole 2. .
[0030]
That is, the tip of the electrode tip 12 in the metal seal faces the welding pin 3 in a non-contact state, and a slight gap e is formed between the tip of the tip and the head 5 of the welding pin. The gap e is set to be shorter than the length of the welding pin 3, so that the height at which the welding pin 3 floats at the tip of the electrode tip is restricted even if the welding pin 3 floats from the high-pressure gas injection hole 2 due to the high-pressure gas flow. As a result, the high-pressure gas injection is efficiently performed while the welding pin 3 is fitted without coming out of the high-pressure gas injection hole 2.
[0031]
Therefore, the welding pin 3 is slightly lifted from the high-pressure gas injection hole 2 by the gap e, and only high-pressure gas is supplied into the shield chamber during that time. This high-pressure gas flow is supplied from the high-pressure gas inflow groove formed by the projection P of the welding pin until the specified filling pressure of the bottle volume is reached.
[0032]
Next, the pressurizing actuator is operated to pressurize and drive the electrode tip 12, and the head 5 of the welding pin 3 is pressed against the peripheral edge of the high-pressure gas injection hole 2 of the bottle main body, for example, 2kN to 4kN electrode necessary for welding Supplying a pressing force and, for example, a welding current having a current value of 8000A to 10000A, the head projection P of the welding pin 3 and the peripheral edge of the high-pressure gas injection hole 2 are intensively heated and melted to complete the high-pressure gas sealing welding ( FIG. 4E).
[0033]
During the above operation process, when the bottle body 1 is particularly a thin plate, the bottle volume expands due to the influence of the high-pressure gas at the time of high-pressure gas injection, and is subject to bending or curvature deformation due to the impact force or heat effect during the pressure welding. However, since the lower clamp electrode 6 and the upper clamp electrode 7 forcibly restrain or shape the entire workpiece side surface including the welded portion by the workpiece clamp surface U having the same curvature as the bottle body side surface R, the workpiece deformation High-pressure gas filling / welding can be performed without receiving any.
[0034]
When the welding is completed in the above cycle, the elevating cylinder 8 is lowered, and the welded bottle body 1 is released from the upper and lower electrode clamps, returned to the original unclamping position, and carried out. After the unloading, the next new bottle body 1 is supplied to the lower clamp electrode, and the welding operation is repeated in the same manner.
【The invention's effect】
As described above, according to the method of claim 1 of the present invention, when high-pressure gas is sealed in the bottle body, conventionally, after the vicinity of the high-pressure gas injection portion is once processed smoothly, a metal seal is formed on the smooth surface. In the present invention, a welding pin is inserted in advance into the high-pressure gas injection part formed on the side surface of the bottle body having a circular cross section. The space around the welding pin is shielded, and the head of the welding pin is energized in the direction of rising by the high-pressure gas flow supplied to the shielded space . Position control is performed by a slight gap provided between the electrode tip in the shield and the high-pressure gas injection part opposite to the electrode tip, and at least one shaft plug of the welding pin is urged in the floating direction. High pressure gas The high-pressure gas remains plugged into the injection hole is injected into the bottle body. Further, the shielding means for forming a shield space on the side surface of the bottle body forms a cylindrical body, a blade edge is formed at the tip of the cylindrical body, and the blade edge has a shape corresponding to the curved shape of the side surface of the bottle body, Moreover, the direction in which the blade edge is pressed against the bottle surface is a normal line of the side surface of the bottle body, and the blade edge of the shield device bites in a state in which the blade edge of the shield device conforms to the curved surface shape of the bottle body side surface R having the high pressure gas injection part The minimum volume required for direct high-pressure gas injection and a completely shielded space can be formed, so that the high-pressure gas injection site can be efficiently filled and welded without the need to process a smooth surface as in the prior art. The equipment is simple and the cost of capital investment can be solved.
[0036]
According to the second and third aspects of the invention, the tip edge of the shield means has a shape in which both sides sandwiching an acute angle are inclined in a V shape, or one side sandwiching the acute angle is outside the cylindrical body. It has a shape that is gradually inclined toward the axial center line , so that the tip edge of the shield means can be easily pushed into the bottle body side surface R from the normal direction of the side surface of the bottle body. , Shielding performance can be drastically improved with the minimum volume required at the high pressure gas injection site.
[0037]
According to claim 4 of the present invention, particularly when the thickness of the bottle body is thin, the first stage is pressurized with a shield pressure so that the bottle body is not deformed by the two-stage pressurization method, and then the second stage. By pressurizing the eyes, the gas filling pressure by the high-pressure gas at the time of gas injection is raised and the shield pressure is raised. Thereby, the shielding property by the front-end | tip blade edge | tip of the said metal seal can be improved.
[0038]
Next, according to the method of claim 5 of the present invention, the entire work side surface including the welded portion is forcibly restrained by the work clamp surface having a concave cross section adapted to the curved surface shape of the bottle body side surface R by the upper and lower clamp electrodes. Therefore, shaping can be performed without undergoing any deformation of the bottle body outer shape.
[0039]
In other words, the bottle body expands due to the influence of the high-pressure gas during high-pressure gas injection, and is affected by impact force and heat during pressure welding, but a shaping effect is obtained by the clamp electrode, thereby preventing deformation of the bottle body. can do.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of necessary components showing an embodiment of a high-pressure gas-filled welding apparatus for carrying out the method of the present invention.
FIG. 2 is a front view showing an embodiment of the apparatus for carrying out the method of the present invention.
FIG. 3 is an external view showing an example of a welding pin.
FIG. 4 is a diagram showing a high-pressure gas filling / welding operation pattern according to the method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bottle main body 2 High pressure gas injection hole 3 Welding pin 4 Shaft plug 5 Head 6 Lower clamp electrode 7 Upper clamp electrode 8 Lifting cylinder 9 Electrode opening 10 Shielding device 11 Metal seal 12 Electrode tip 13 O-ring 14 Shield space 15 High pressure gas Supply source 16 High-pressure gas supply circuit 17 High-pressure gas supply port P Projection Q Sharp angle R Bottle body side T Welding transformer U Work clamp surface

Claims

A high-pressure gas injection hole previously drilled in the side surface of the bottle body having a circular cross section, a head having a diameter that blocks the diameter of the high-pressure gas injection hole, and a shaft plug having a diameter smaller than the diameter of the high-pressure gas injection hole And a high-pressure gas inflow groove formed in the head, and the periphery of the high-pressure gas injection hole including the welding pin is locally shielded by shielding means, and then the high-pressure gas is introduced into the shielded space. When the high pressure gas is supplied from the high pressure gas inflow groove formed in the welding pin into the bottle body and a predetermined high pressure gas filling pressure is reached, the electrode tip inserted in the shield is operated. the welding pin head pressed against the high-pressure gas injection holes, further said the high pressure gas filling welding method of projection welding giving pressure and the welding current required to weld through the electrode tip, before Te Shielding means has a cylindrical body, moreover the cutting edge is formed at the tip of the cylindrical body of the shielding means, said cutting edge from said normal direction of the side surface of the bottle body with a shape corresponding to the curved shape of the bottle body side When pressing the welding pin in the direction of rising with the high-pressure gas injected into the shield so as to be pressed against the side surface of the bottle main body, the head of the welding pin facing the electrode tip in the shield A gap e for regulating the height of the welding pin in the flying direction is set between the bottles so that at least a part of the shaft plug of the welding pin is inserted into the high-pressure gas injection hole. A high-pressure gas-filled welding method, wherein high-pressure gas is injected into the body and sealed by the welding operation .

2. The high-pressure gas-filled welding method according to claim 1, wherein one of the sides sandwiching an acute angle is inclined or both sides sandwiching the acute angle are inclined in the shape of the blade tip formed at the tip of the cylindrical body of the shield means . A high-pressure gas-filled welding method characterized by that.

3. The high-pressure gas filling welding method according to claim 2, wherein the tip of the shield means is cut into the side surface of the bottle body, thereby shielding the periphery of the high-pressure gas injection hole on the side surface of the bottle body. Filling welding method.

The high-pressure gas-filled welding method according to claim 1, 2 or 3, wherein the shield means is shield-pressurized by a two-stage pressurization method, and the leading edge of the shield means is applied to the side surface of the bottle body by the first-stage pressurizing force. After the bite, in the high-pressure gas injection process, when the high-pressure gas filling pressure of the bottle body reaches a preset high-pressure gas filling pressure, the second-stage pressure increased further than the first-stage applied pressure. A high-pressure gas-filled welding method characterized in that pressurization is performed, thereby improving the shielding performance of a thin bottle body.

5. The high-pressure gas-filled welding method according to claim 1, wherein the bottle body is clamped and held by a resistance welding machine having a lower clamp electrode and an upper clamp electrode, and the lower clamp electrode and the upper clamp electrode are A work clamp surface having a concave cross section that substantially supports the side surface of the bottle body and a work feeding surface are combined, and the side surface of the bottle body including the vicinity of the welded portion is forcibly constrained by the lower clamp electrode and the upper clamp electrode. Thus, the high pressure gas filling welding method is characterized in that deformation of the bottle main body which occurs at the time of high pressure gas injection and / or pressure welding is prevented.