JP4085887B2

JP4085887B2 - Sealed container and manufacturing method thereof

Info

Publication number: JP4085887B2
Application number: JP2003144540A
Authority: JP
Inventors: 昭慈今永; 光明羽田; 正寿稲垣; 修渡辺; 良樹杣友
Original assignee: Hitachi Ltd; Hitachi Maxell Energy Ltd
Current assignee: Hitachi Ltd; Hitachi Maxell Energy Ltd
Priority date: 2003-05-22
Filing date: 2003-05-22
Publication date: 2008-05-14
Anticipated expiration: 2023-05-22
Also published as: JP2004344926A

Description

【０００１】
【発明の属する技術分野】
本発明は、非電池部品類が収納された容器の開口部を密閉する蓋板表面にある小径穴を封止する新規な密閉容器及びその製造方法に関する。
【０００２】
【従来の技術】
【特許文献１】
特開平８−４５４８８号公報
【特許文献２】
特開平１１−２５９３６号公報
【特許文献３】
特開平１１−１４９９１５号公報
【特許文献４】
特開２００２−２３９７６２号公報
携帯電話やノート型パソコンなどの情報機器の普及により、密閉型電池の需要が高まっている。中でも、リチウムイオン電池は、ニカド電池やニッケル水素電池と比べエネルギー密度、作動電圧が高く、各種の情報機器などの電源に多く使用されてきている。
【０００３】
密閉が必要な密閉型電池は、主に正極材、セパレータ、負極材などの電池部品を収納した電池容器と、この電池容器の開口上部を密閉する蓋板とを事前に一体接合し、この蓋板表面に予め設けられている小径の穴から有機溶剤の電解液を容器内に注入した後に、この小径穴を最後に完全封止して製造されている。電池容器及び蓋板には、従来から安価なスチール材、耐食性に優れたステンレス鋼材が用いられ、最近では、軽量なアルミニウム材が多く用いられてきている。
【０００４】
使用する金属の材質、接合方法や接合条件などに大きな相違があっても、密閉型電池の製造工程で、容器内を密閉保持するべく、最後に小径穴を完全封止する必要がある。小径穴を封止するための封止方法がこれまでに幾つか提案されている。
【０００５】
例えば、特許文献１の密閉型電池では、電解液を注入した後、小径穴にアルミニウム製の球状の封止栓を押圧し、超音波溶接で封止することが提案されている。又、特許文献２の角形密閉式蓄電池及びその製造方法、特許文献３の密閉型電池では、小径穴に封止栓を挿入し、レーザー溶接で封止することがそれぞれ提案されている。また、特許文献４の容器における注入口の封止方法及び密閉容器では、注入口にステンレス製の球状の封止部材を押し込み、手段の異なる抵抗溶接とレーザー溶接の二段階で封止溶接することが提案されている。
【０００６】
【発明が解決しようとする課題】
特許文献１〜４のいずれの従来技術においても、超音波溶接或はレーザ溶接等により注入穴に挿入した封止栓の外周と蓋板表面との継ぎ部のみを溶接させる浅い溶け込みの円周溶接である。隙間腐食を抑えるには、裏面側の継ぎ部は未接合部を残さない方が良い。又、レーザービーム溶接の場合、ビームを照射する継ぎ部に隙間が生じていたり、注入穴部分に液が付着していたりすると、溶接ビードの形成に乱れが生じ易く、ピンホールの発生によって未接合部分が生じ易い。以上の電池容器における問題点は、電子部品などの非電池部品を収納する小型容器の製造においても同様である。
【０００７】
本発明の目的は、非電池部品類が収納された容器の開口部を密閉する蓋板表面にある小径穴を溶接によって容易かつ確実に封止でき、溶接後の表面が平滑で高品質な溶接部を得ることができる密閉容器及びその製造方法を提供することにある。
【０００８】
【課題を解決するための手段】
本発明は、非電池部品類が収納された容器の開口部を密閉する金属製の蓋板と、該蓋板表面に設けられた小径穴を封止する金属製の封止栓とを有する密閉容器において、前記蓋板は前記小径穴近傍裏面側にその外周部より薄い薄肉部を有する平面形状が円形又は多角形であるザグリ溝が形成され、前記封止栓はその頭部に平面形状で円形又は多角形である張出し部を有し、前記封止栓と蓋板の薄肉部との溶接によって封止されていることを特徴とする。
【０００９】
また、本発明は、前述の密閉容器において、前記蓋板は前記小径穴近傍裏面側にその外周部より薄い薄肉部を有する平面形状が円形又は多角形であるザグリ溝が形成され、前記封止栓の頭部に形成された平面形状が円形又は多角形である張り出し部と薄肉部との溶接によって前記封止されていることを特徴とする。
【００１０】
前記小径穴は平面形状が円形又は多角形であり、前記封止栓は前記小径穴の径より大きい径の張り出し部と前記小径穴に挿入する円形又は多角形の挿入部とを有し、該封止栓頭部の張り出し部は蓋板の薄肉部の体積と同程度又はそれよりも小さい体積を有することが好ましい。
【００１１】
更に、本発明は、非電池部品類が収納された容器の開口部を金属製の蓋板によって密閉し、前記蓋板表面に設けられた小径穴を金属製の封止栓によって封止する密閉容器の製造方法において、前記蓋板の前記小径穴近傍裏面側にその外周部より薄い薄肉部を有する平面形状が円形又は多角形であるザグリ溝を形成し、前記封止栓の頭部に平面形状で円形又は多角形である張出し部を形成し、前記封止栓と薄肉部との溶接によって前記封止することを特徴とする。
【００１２】
また、本発明は、前述の密閉容器の製造方法において、前記蓋板の前記小径穴近傍裏面側にその外周部より薄い薄肉部を有する平面形状が円形又は多角形であるザグリ溝を形成し、前記封止栓の頭部に平面形状が円形又は多角形である張り出し部を形成し、該張り出し部と蓋板の薄肉部との溶接によって前記封止することを特徴とする。
【００１３】
前記封止栓を前記小径穴に挿入する工程と、前記封止栓をアーク熱源又はレーザー熱源により溶融して前記小径穴を封止溶接する工程と、前記封止後の溶接部を検査する検査工程とを有することを特徴とする。
【００１４】
さらに、前記溶接は非消耗性電極によるＴＩＧアーク溶接又はプラズマアーク溶接によって行い、該アーク溶接における電流Ｉ（Ａ）と溶接時間Ｔ（ｍｓ）とを下記の（１）式に基づいて設定することが好ましい。但し、ｂは接合部分の溶融に係わる定数、ｃは栓頭部の加熱に係わる定数である。
【００１５】
Ｉ＝(ｃ／Ｔ) ^ｂ ……（１）
すなわち、本発明は、前記蓋板の前記小径穴近傍裏面側にその外周部より薄い薄肉部を有する平面形状が円形又は多角形であるザグリ溝を形成することにより、その薄肉部のみを短時間で少ないエネルギーで加熱溶融できるので、溶融範囲のバラツキが極めて少ない溶接部を得ることができる。また、封止栓の頭部に短時間で溶融可能な大きさの平面形状が円形又は多角形である張り出し部を形成すると、封止栓の頭部を冶具で簡単につかんで小径穴へ圧入することができ、張り出し部の下面と小径穴周囲の蓋板表面とを確実に密着させることができるばかりでなく、蓋板表面の高さより突き出した栓頭部にアーク熱源を加え易く、短時間で確実に溶融させることができる。
【００１６】
特に、封止栓頭部の張出し部は、少なくとも蓋板表面にある小径穴の内径より大きく、蓋板の裏面側に設けたザグリ溝の内径より小さい径にし、前記ザグリ溝上部の薄肉部(ツバ部分)の体積と同程度又は幾分小さい体積に形成すると、融合すべき蓋板の薄肉部との体積バランスが良くなり、短時間のアーク加熱によって封止栓頭部の張り出し部又は封止栓全体を確実に溶融でき、蓋板表面の薄肉部と平滑に一体融合させることができる。
【００１７】
また、本発明は、封止栓の挿入部を蓋板表面の小径穴に挿入する工程と、該封止栓をアーク熱源により溶融して前記小径穴を封止溶接する工程と、封止溶接後の溶接部を検査する検査工程とを少なくとも有することにより、製造ラインでの自動溶接によって穴封止できるばかりでなく、該溶接後の不良品を除外し、合格品のみを選択、認定することができるので、密閉性の高い密閉容器を提供することができる。
【００１８】
特に、前記アーク熱源として、非消耗性電極によるＴＩＧアーク又はプラズマアークを用い、前述の関係式に基づいて溶接条件を設定すると、確実な封止溶接ができ、溶接条件の管理、溶接品質の管理が容易となる。ＴＩＧアーク溶接やプラズマアーク溶接の他に、レーザー溶接も可能である。
【００１９】
【発明の実施の形態】
（実験例）
図１は、本発明に関連する密閉容器の一例である角形密閉電池の斜視図である。図１において、角形密閉電池の密閉容器１の内部(図示せずに省略)には、正極材、セパレータ、負極材、タブなどの電池部品が収納され、電池用の密閉容器１が正極端子を兼ねている。電池用の密閉容器１の上部には、密閉するための蓋板２が装着され、蓋板２の外周継ぎ部を溶接８して密閉容器１と一体接合されている。蓋板２の外周継ぎ部の溶接８は、レーザー熱源やアーク熱源を与えて接合するレーザー溶接法やアーク溶接法によって行うことが可能である。蓋板２の中央部には、負極端子７が絶縁パッキング６を介して予め固定されている。また、蓋板２には、電解液を注入するための小径穴４が予め設けられており、この小径穴４に封止栓３を挿入し、アーク溶接によって完全に封止溶接するようにしている。これら電池用の密閉容器１、蓋板２、封止栓３には、いずれも軽量なアルミニウム材が用いられる。なお、電池用の密閉容器１に安価なスチール材又は耐食性に優れたステンレス材を用いる場合には、蓋板２及び封止栓３の材料も、電池用の密閉容器１と同じ材質又は類以材質を用いることが望ましい。いずれも溶接性を良くするためである。
【００２０】
図２は、本発明に関連する製造方法に係る小径穴及び封止栓の一実施形態を示す断面図である。図２に示すように、小径穴４の外周部には、蓋板２の裏面側に蓋板２より薄肉とした平面形状が円形である薄肉部５ｂを有するザグリ溝５が設けられている。例えば、小径穴４の大きさは約ｄ1＝１〜２ｍｍである。また、ザグリ溝５の大きさは、約ｄ2＝２〜３ｍｍであり、そのザグリ溝５上部のツバ部分（薄肉部）の厚みｈは、蓋板２の厚さｔに対して、ｔ／２≦ｈ≦ｔ／３程度にするとよい。一方、この小径穴４に挿入する封止栓３の頭部には、短時間で溶融可能な大きさの薄肉を有し、平面形状が円形である張出し部３ａを設けている。図２に示した封止栓３は、全体を円形にした加工が簡単な平面形状をしている。
【００２１】
図３は、小径穴の外周部に設けるザグリ溝の形状が異なる一実施形態を示す断面図である。蓋板２の裏面側に形成されたザグリ溝５の形状は、平面形状で円形だけでなく、図３に示した多角形にしてもよい。さらに、小径穴４の形状を平面形状で多角形にすることも可能であり、この時には、多角形の小径穴に挿入する封止栓３の挿入部３ｂの形状を多角形に統一して挿入可能にすればよい。この小径穴４に挿入する封止栓３の頭部には、短時間で溶融可能な大きさの薄肉を有する張出し部３ａを設けている。
【００２２】
図４〜７は、種々の封止栓の形状を示す平面図及び断面図である。図４は、封止栓３の張り出し部３ａ及び小径穴４への挿入部３ｂが共に平面形状が円形であるものである。図５は、封止栓３の張り出し部３ａの平面形状が六角形及び小径穴４への挿入部３ｂの平面形状が円形であるものである。図６に示した封止栓３の頭部は、滑らかな曲面形状又は半球形状をしており、また、図７に示した封止栓３の頭部は、中央に突起を有する形状をしており、溶接時に位置合せを容易にすることができる。
【００２３】
これらの封止栓３頭部に設ける円形又は多角形の張出し部３ａは、いずれの場合も、少なくとも小径穴４の内径ｄ1より大きく、ザグリ溝５の内径ｄ2より小さい外径(ｄ1＜Ｄ＜ｄ2)にし、ザグリ溝５上部のツバ部分５ｂの体積(小径穴を含む合計体積｛（ｄ2^２−ｄ１^２）πｈ／４｝と同程度又は幾分小さい体積に形成するとよい。封止栓３の張り出し部を多角形にすると、転がりにくくつかみ易く、体積の調整も容易である。このように形状の異なる封止栓３や蓋板２は、例えば、金型成形加工よって容易に製作することができる。
【００２４】
張出し部３ａを有する封止栓３は、小径穴４から電解液を注入した後に、封止栓３の下部３ｂを押し込み、張り出し部分３ａの下面と小径穴４周囲のツバ部分５ｂ上面(蓋板表面)とを密着させる。その後、アーク熱源を封止栓３頭部より与えて、張出し部３ａと蓋板２表面の小径穴４周辺部とを封止溶接する。
【００２５】
このように、封止栓３頭部に短時間で溶融可能な円形又は多角形の張出し部３ａを設けると、封止栓３の張出し部３ａを冶具などで簡単につかんで小径穴４へ圧入することができ、張出し部３ａの下面と小径穴４周囲の蓋板表面とを確実に密着させることができるばかりでなく、蓋板表面より凸形状に突き出した封止栓３頭部にアーク熱源を加え易くなる。また、円形又は多角形のザグリ溝５を蓋板２の裏面側に設けると、封止溶接すべき小径穴４周辺部の肉厚が薄く、表面側から行うアーク溶接で裏側まで完全に溶融させることができる。また、張出し部の３ａの体積をツバ部分５ｂ(薄肉部)の体積と同程度又は幾分小さい体積に形成すると、融合すべきツバ部分５ｂとの体積バランスが良くなり、短時間で封止栓３頭部を確実に溶融でき、蓋板表面の小径穴４周辺のツバ部分と平滑に一体融合させることができる。
【００２６】
図８は、本発明に関連する製造方法による小径穴の封止をＴＩＧアーク溶接によって行う工程を示す断面図及び溶接電流と時間との関係を示す線図であり、（１）溶接前の封止栓と電極の配置、（２）封止栓頭部のアーク加熱、（３）封止栓頭部の球形溶融、（４）蓋板ツバ部との一体融合、（５）溶接後の溶接部、（６）時間経過の電流波形の様子をそれぞれ示している。この実施例で用いているアーク熱源は、非消耗性のタングステンを電極１２にするＴＩＧアークであり、所定の溶接条件(電流と溶接時間)を溶接電源に設定し出力させている。本実施例における小径穴４及び封止栓３の平面形状は前述のいずれの形状での組み合わせにおいても同様の工程によって行うことができる。
【００２７】
図８（１）に示したように、蓋板２の裏側にザグリ溝５を有する小径穴４に密着挿入された封止栓３の頭部中央に電極１２先端を位置決めする。溶接開始によってシールドガス（Ａｒガス）流出の雰囲気内で封止栓３頭部にアーク１１を発生させ、図８（６）に示したように所定時間Ｔ(ｍｓ)の電流Ｉ(Ａ)を出力させている。次に、図８（２）示すようにアーク加熱によって封止栓３頭部の張り出し部分３ａが最初に溶融し、図８（３）に示すように、溶融金属の表面張力によって球形状に溶融変化する。そして、図８（４）に示すように、その後に加熱溶融される小径穴４周辺のツバ部分と、既に球形状に溶融変化した封止栓３頭部の張出し部３ａとが平滑に一体融合し、蓋板２の裏側まで完全に溶け込ますことができる。更に、図８（５）に示すように溶接後の表面が平滑で略円形を有する完全封止の良好な溶接部９を得ることができる。
【００２８】
図９は、小径穴の封止溶接における適正な時間と電流の関係を示す線図である。本実施例の小径穴４及び封止栓３の平面形状は前述の図２及び図４のいずれも円での組み合わせによって行ったものである。図中の○印が接合良好な領域である。蓋板２及び封止栓３は、いずれもアルミニウム材であり、小径穴４の径ｄ1が１．４ｍｍ、ザグリ溝５の径ｄ2が２．４ｍｍ、ツバ部分５ａの厚みｈが約０．３ｍｍの小径穴封止の結果を示している。例えば、電流Ｉが９０Ａの時には約２９ｍｓの短い時間、４０Ａの時には約１００ｍｓでアーク溶接すると、良好な溶接部９を得ることができる。
【００２９】
接合良好な適正条件は、電流Ｉ(Ａ)と時間Ｔ(ｍｓ)との相関関係があり、下記の（１）式で求めることができる。ただし、ｂは、小径穴３接合部分の溶融に係わる乗数であり、封止栓３及び蓋板２の小径穴４周辺部の形状や材質などの違いで変化し、０．５〜０．８程度となる。また、ｃは、栓頭部の加熱に係わる定数であり、約９３００〜１７５０００の範囲である。
【００３０】
Ｉ＝(ｃ／Ｔ) ^ｂ・・・（１）
このように、所定条件のアーク熱源を封止栓３の頭部より短時間与えて加熱溶融させると、封止栓３の張り出し部分３ａと蓋板２表面の小径穴４周辺部とが適正に一体融合し完全封止することができ、溶接後の表面が平滑で高品質な溶接部９を得ることができる。また、溶接条件を少なくとも電流と溶接時間との関係式に基づいて設定すると、完全封止が可能な適正条件を確実に出力でき、溶接条件の管理、溶接の品質管理が容易となる。
【００３１】
アルミニウム材と異なる他のステンレス材やスチール材やニッケル材などの金属材料に対しても、図８に示したＴＩＧアーク溶接によって良好に穴封止溶接を行うことが可能である。これらの金属材料は、アルミニウム材より融点が高いが、電気抵抗が大きいためにＴＩＧアークによる通電加熱で溶融し易い材料である。また、ＴＩＧアークによる穴封止溶接の代わりにプラズマアーク及び溶接電源を用い、封止栓３の頭部よりアーク熱源を与えて加熱溶融させても、ＴＩＧアーク溶接の時とほぼ同様に、封止栓３の張出し部３ａと蓋板２表面の小径穴４周辺部とが適正に一体融合して完全封止でき、溶接後の表面が平滑で高品質な溶接部を得ることが可能である。プラズマアーク溶接は、電極の外周部にあるノズル及びノズル穴から流出するプラズマガスで保護されているので、電極の寿命が長く、長時間使用が可能である。
【００３２】
図１０は、本発明に関連する密閉容器の一例である角型電池の製造工程を示すフロー図である。最初の工程で製造組立２１された電池部品を電池用の密閉容器１内に収納２２する。この容器上面の開口部を密閉するため、次の工程で、蓋板２を装着２３した後に、例えば、レーザー溶接で蓋板２をその外周に沿って電池用の密閉容器１に封止溶接２４をする。その後、予め蓋板２に設けられた小径穴４より電池用の密閉容器１内に電解液１０を注入２５する。次の工程で封止栓３を小径穴４に圧入２７する。最後に小径穴４を密閉するため、アーク熱源による小径穴４の封止溶接２８をする。この封止溶接２８後に溶接部８、９及び液漏れの検査２９を行う。アーク熱源の代わりにレーザー熱源を用いて該小径穴４の封止溶接を行うことも可能である。図示していないが、さらに、電池外装の洗浄と乾燥、電池の充電、性能試験や品質検査などを行う。
【００３３】
このように、電池部品の製造組立２１から溶接後の溶接部及び液漏れの検査２９まで製造工程により、密閉が必要な所望の密閉容器及び電池を一連の製造ラインで確実に生産することができる。特に、小径穴の封止溶接２８において、封止栓の張り出し部３ａと前記蓋板表面の小径穴周辺部との一体融合が可能な溶接条件を出力させてアーク溶接すると、従来のレーザー溶接による円周封止溶接と異なる融合形態及び溶け込み形状になり、溶接後の表面が平滑で高品質な溶接部を得ることができる。また、溶接後に行う溶接部及び液漏れの検査によって、不良品を除外し、合格品のみを選択、認定するので、密閉性の高い密閉容器及び電池を確実に生産することができる。
【００３４】
以上、本実験例によれば、封止栓の頭部に形成した平面形状が円形又は多角形である張り出し部と、同様の平面形状を有する蓋板表面の小径穴周辺部の薄肉部との一体融合によって、小径穴を短時間で少ないエネルギーで容易に溶融でき、確実に完全封止することができる。更に、表面が平滑で欠陥のない高品質な溶接部が得られ、バラツキの少ない密閉性の高い密閉容器を製造することができる。
【００３５】
（実施例）
図１１は、本発明の非電池部品類を収納する密閉容器の斜視図である。本実施例における部品類を収納するものとして、例えば、電子部品を収納した小径容器、センサ部品を収納した密閉容器、微細な機械部品を収納した密閉容器などがある。これらの密閉容器１の上部にある金属製の蓋板２表面に小径穴４が設けられており、この小径穴４を実験例と同様に密閉するために封止栓３を挿入して封止溶接することができる。小径穴４及び封止栓３の平面形状の組み合わせは実験例と同様に行うことができる。
【００３６】
図１２は、図１１に示した密閉容器の小径穴を封止溶接する工程の一実施形態を示すフロー図である。最初に、別の工程で製造された部品類を容器内に収納し、その容器１上部を蓋板２で密閉して密閉容器の組み立て２０が行われる。次の工程で蓋板２表面にある小径穴４に封止栓３を圧入して封止栓挿入２７ｂを行う。封止栓３挿入後の次の工程で、小径穴４を密閉するためにアーク熱源又はレーザー熱源による小径穴４の封止溶接３０を行う。最後に封止溶接後の溶接部９の品質検査３１を行う。特に、小径穴４を封止溶接３０する工程で、図８に示したように封止栓３の張り出し部と蓋板２表面の小径穴４周辺部との一体融合が可能な溶接条件を出力させてアーク溶接すると、溶接後の表面が平滑で高品質な溶接部を得ることができる。また、アーク溶接の代わりにレーザー熱源を用いて該小径穴４の封止溶接を行うことも可能である。そして、封止溶接した後に行う溶接部の品質検査３１によって、不良品を除外し、合格品のみを選択、認定できるので、密閉性の高い密閉容器を確実に生産することができる。
【００３７】
以上、本実施例によれば、実験例と同様に、封止栓の頭部に形成した平面形状が円形又は多角形である張り出し部と、同様の平面形状を有する蓋板表面の小径穴周辺部の薄肉部との一体融合によって、小径穴を短時間で少ないエネルギーで容易に溶融でき、確実に完全封止することができる。更に、溶接後の表面が平滑で欠陥のない高品質な溶接部が得られ、バラツキの少ない密閉性の高い密閉容器を製造することができる。
【００３８】
【発明の効果】
以上、本発明によれば、小径穴を短時間で少ないエネルギーで容易に溶接でき、確実に完全封止することができる。また、溶接後の表面が平滑で欠陥のない高品質な溶接部が得られ、バラツキの少ない密閉性の高い密閉容器及びその製造方法を提供することができる。
【図面の簡単な説明】
【図１】本発明に関連する密閉容器の一例である角形電池の斜視図である。
【図２】本発明に関連する封止栓の一例を示す断面図及び小径穴の一例を示す断面図及び平面図である。
【図３】本発明に関連する小径穴の他の例を示す断面図及び平面図である。
【図４】本発明に関連する封止栓の一例を示す平面図及び断面図である。
【図５】本発明に関連する封止栓の他の例を示す平面図及び断面図である。
【図６】本発明に関連する封止栓及び小径穴の他の例を示す断面図である。
【図７】本発明に関連する封止栓及び小径穴の他の例を示す断面図である。
【図８】本発明に関連する小径穴をＴＩＧアーク溶接によって封止する工程を示す封止栓及び小径穴の断面図である。
【図９】本発明に関連する小径穴の封止溶接における溶接時間と電流との関係を示す線図である。
【図１０】本発明に関連する密閉容器の一例である角形電池の製造工程を示すフロー図である。
【図１１】本発明に係る密閉容器の他の例を示す斜視図である。
【図１２】本発明に係る密閉容器の他の例の小径穴を封止溶接する製造工程を示すフロー図である。
【符号の説明】
１…密閉容器、２…蓋板、３…封止栓、３ａ…張り出し部、３ｂ…挿入部、４…小径穴、５…ザグリ溝、５ａ…ツバ部分、６…絶縁パッキング、７…負極端子、８…蓋板外周の溶接部、９…小径穴封止の溶接部、１１…アーク、１２…電極。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel sealed container that seals a small-diameter hole in a cover plate surface that seals an opening of a container in which non-battery components are stored, and a method for manufacturing the same.
[0002]
[Prior art]
[Patent Document 1]
JP-A-8-45488 [Patent Document 2]
JP 11-25936 A [Patent Document 3]
JP-A-11-149915 [Patent Document 4]
With the widespread use of information devices such as mobile phones and laptop computers, the demand for sealed batteries is increasing. Among them, lithium ion batteries have higher energy density and operating voltage than nickel-cadmium batteries and nickel-metal hydride batteries, and have been widely used as power sources for various information devices.
[0003]
In a sealed battery that needs to be sealed, a battery container that mainly stores battery components such as a positive electrode material, a separator, and a negative electrode material, and a lid plate that seals the upper opening of the battery container are integrally joined in advance. An organic solvent electrolyte is injected into the container from a small-diameter hole provided in advance on the surface of the plate, and the small-diameter hole is finally completely sealed. Conventionally, inexpensive steel materials and stainless steel materials with excellent corrosion resistance have been used for battery containers and lid plates, and recently, lightweight aluminum materials have been used frequently.
[0004]
Even if there is a large difference in the material of the metal used, the joining method, the joining conditions, etc., it is necessary to completely seal the small-diameter hole at the end in order to keep the inside of the container hermetically in the manufacturing process of the sealed battery. Several sealing methods for sealing the small-diameter hole have been proposed so far.
[0005]
For example, in the sealed battery of Patent Document 1, after injecting an electrolytic solution, it is proposed that a spherical sealing plug made of aluminum is pressed into a small-diameter hole and sealed by ultrasonic welding. In addition, in the rectangular sealed storage battery and the manufacturing method of Patent Document 2 and the sealed battery of Patent Document 3, it has been proposed to insert a sealing plug into a small-diameter hole and seal it by laser welding. In addition, in the sealing method and the sealed container in the container of Patent Document 4, a spherical sealing member made of stainless steel is pushed into the inlet, and sealing welding is performed in two stages of resistance welding and laser welding with different means. Has been proposed.
[0006]
[Problems to be solved by the invention]
In any of the prior arts disclosed in Patent Documents 1 to 4, shallow penetration circumferential welding that welds only the joint between the outer periphery of the sealing plug inserted into the injection hole and the lid plate surface by ultrasonic welding or laser welding or the like. It is. In order to suppress crevice corrosion, it is better not to leave an unjoined part at the joint on the back side. In the case of laser beam welding, if there is a gap in the joint where the beam is irradiated or if liquid adheres to the injection hole, the formation of the weld bead is likely to be disturbed, and the unbonded due to the occurrence of the pinhole. Part tends to occur. The above problems in the battery container are the same in the manufacture of a small container for storing non-battery parts such as electronic parts.
[0007]
The object of the present invention is to easily and reliably seal a small-diameter hole on the lid plate surface that seals the opening of a container in which non-battery parts are stored, and to weld with a smooth and high-quality surface after welding. It is in providing the airtight container which can obtain a part, and its manufacturing method.
[0008]
[Means for Solving the Problems]
The present invention includes a metal lid plate that seals an opening of a container in which non-battery components are stored, and a metal seal plug that seals a small-diameter hole provided on the surface of the lid plate. In the container, the cover plate is formed with a counterbore groove having a circular or polygonal planar shape having a thin wall portion thinner than the outer peripheral portion on the back side near the small-diameter hole, and the sealing plug has a planar shape on its head. It has a projecting portion that is circular or polygonal, and is sealed by welding between the sealing plug and the thin portion of the cover plate.
[0009]
Further, the present invention is the above-mentioned sealed container, wherein the cover plate is formed with a counterbore groove having a circular or polygonal planar shape having a thin wall portion thinner than the outer peripheral portion on the back side near the small-diameter hole. The sealing is characterized in that the planar shape formed on the head of the stopper is circular or polygonal, and is sealed by welding between a protruding portion and a thin portion.
[0010]
The small-diameter hole has a circular or polygonal planar shape, and the sealing plug has a projecting portion having a diameter larger than the diameter of the small-diameter hole and a circular or polygonal insertion portion inserted into the small-diameter hole, It is preferable that the protruding portion of the sealing plug head has a volume that is the same as or smaller than the volume of the thin portion of the lid plate.
[0011]
Furthermore, the present invention provides a hermetic seal in which an opening of a container in which non-battery components are stored is sealed with a metal lid plate, and a small-diameter hole provided in the lid plate surface is sealed with a metal sealing plug. In the container manufacturing method, a counterbore groove having a circular or polygonal planar shape having a thin wall portion thinner than its outer peripheral portion is formed on the back surface near the small-diameter hole of the lid plate, and is flat on the head of the sealing plug. A projecting portion that is circular or polygonal in shape is formed, and the sealing is performed by welding the sealing plug and the thin-walled portion.
[0012]
Further, the present invention, in the method for manufacturing a closed container described above, a counterbore groove having a circular or polygonal planar shape having a thin wall portion thinner than its outer peripheral portion on the back surface side near the small-diameter hole of the lid plate, A protruding portion having a circular or polygonal planar shape is formed on the head of the sealing plug, and the sealing is performed by welding the protruding portion and the thin portion of the lid plate.
[0013]
Inserting the sealing plug into the small-diameter hole, melting the sealing plug with an arc heat source or a laser heat source and sealing welding the small-diameter hole, and inspecting the welded portion after the sealing And a process.
[0014]
Further, the welding is performed by TIG arc welding or plasma arc welding with a non-consumable electrode, and the current I (A) and welding time T (ms) in the arc welding are set based on the following equation (1). Is preferred. However, b is a constant number relating to the melting of the joint portion, c is a constant related to the heating of the plug head.
[0015]
I = (c / T) ^b (1)
That is, the present invention forms a counterbore groove in which the planar shape having a thin part thinner than the outer peripheral part is circular or polygonal on the back surface near the small-diameter hole of the lid plate, so that only the thin part is shortened for a short time. Since it can be heated and melted with a small amount of energy, it is possible to obtain a welded portion with extremely small variation in the melting range. In addition, if an overhanging part with a circular or polygonal planar shape that can be melted in a short time is formed on the head of the sealing plug, the head of the sealing plug can be easily grasped with a jig and pressed into a small-diameter hole. In addition to ensuring that the lower surface of the overhang and the surface of the cover plate around the small-diameter hole are in close contact with each other, it is easy to apply an arc heat source to the plug head protruding from the height of the cover plate surface, and for a short time. Can be surely melted.
[0016]
In particular, the overhanging portion of the sealing plug head is at least larger than the inner diameter of the small-diameter hole on the surface of the lid plate and smaller than the inner diameter of the counterbore groove provided on the back surface side of the lid plate, If the volume is the same as or slightly smaller than the volume of the collar part, the volume balance with the thin part of the lid plate to be fused is improved, and the overhanging part or sealing of the sealing plug head is achieved by short-time arc heating. The entire stopper can be reliably melted, and can be smoothly and integrally fused with the thin wall portion of the lid plate surface.
[0017]
The present invention also includes a step of inserting the insertion portion of the sealing plug into the small-diameter hole on the surface of the lid plate, a step of sealing the small-diameter hole by melting the sealing plug with an arc heat source, and sealing welding. By having at least an inspection process for inspecting the subsequent welded part, not only can the hole be sealed by automatic welding on the production line, but also exclude defective products after the welding and select and certify only the acceptable products. Therefore, an airtight container with high airtightness can be provided.
[0018]
In particular, when a TIG arc or plasma arc with a non-consumable electrode is used as the arc heat source and the welding conditions are set based on the above-described relational expression, reliable sealed welding can be performed, and the welding conditions are controlled and the welding quality is controlled. Becomes easy. In addition to TIG arc welding and plasma arc welding, laser welding is also possible.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
(Experimental Example)
FIG. 1 is a perspective view of a prismatic sealed battery which is an example of a sealed container related to the present invention. In FIG. 1, a battery component such as a positive electrode material, a separator, a negative electrode material, a tab, and the like is housed in a closed container 1 (not shown) of a rectangular sealed battery, and the battery closed container 1 has a positive electrode terminal. Also serves as. A lid plate 2 for sealing is attached to the upper portion of the battery sealed container 1, and the outer peripheral joint portion of the lid plate 2 is welded 8 and integrally joined to the sealed container 1. The welding 8 of the outer peripheral joint portion of the cover plate 2 can be performed by a laser welding method or an arc welding method in which a laser heat source or an arc heat source is applied and joined. A negative electrode terminal 7 is fixed in advance to the center portion of the lid plate 2 via an insulating packing 6. Further, the lid plate 2 is provided with a small-diameter hole 4 for injecting an electrolytic solution in advance, and a sealing plug 3 is inserted into the small-diameter hole 4 and completely sealed and welded by arc welding. Yes. Lightweight aluminum materials are used for the sealed container 1, the cover plate 2, and the sealing plug 3 for these batteries. In addition, when an inexpensive steel material or a stainless steel material having excellent corrosion resistance is used for the battery sealed container 1, the materials of the cover plate 2 and the sealing plug 3 are the same as or similar to the battery sealed container 1. It is desirable to use a material. Both are for improving the weldability.
[0020]
FIG. 2 is a cross-sectional view showing an embodiment of a small diameter hole and a sealing plug according to the manufacturing method related to the present invention. As shown in FIG. 2, a counterbore groove 5 having a thin wall portion 5 b having a circular planar shape that is thinner than the cover plate 2 is provided on the back surface side of the cover plate 2 on the outer peripheral portion of the small diameter hole 4. For example, the size of the small diameter hole 4 is about d1 = 1 to 2 mm. The size of the counterbore groove 5 is about d2 = 2 to 3 mm, and the thickness h of the brim portion (thin wall portion) at the top of the counterbore groove 5 is t / 2 with respect to the thickness t of the cover plate 2. It is preferable that ≦ h ≦ t / 3. On the other hand, the head portion of the sealing plug 3 to be inserted into the small-diameter hole 4 is provided with an overhang portion 3a having a thin wall that can be melted in a short time and having a circular planar shape. The sealing plug 3 shown in FIG. 2 has a planar shape that can be easily processed into a circular shape.
[0021]
FIG. 3 is a cross-sectional view showing an embodiment in which the shape of a counterbore groove provided on the outer peripheral portion of the small-diameter hole is different. The shape of the counterbore groove 5 formed on the back surface side of the cover plate 2 may be a polygon shown in FIG. Further, the shape of the small-diameter hole 4 can be made into a polygonal shape in a planar shape. At this time, the shape of the insertion portion 3b of the sealing plug 3 to be inserted into the small-diameter hole of the polygon is unified into a polygonal shape. You can make it possible. At the head of the sealing plug 3 to be inserted into the small-diameter hole 4, an overhanging portion 3a having a thin wall with a size that can be melted in a short time is provided.
[0022]
4-7 is the top view and sectional drawing which show the shape of various sealing plugs. In FIG. 4, both the projecting portion 3 a of the sealing plug 3 and the insertion portion 3 b into the small diameter hole 4 have a circular planar shape. In FIG. 5, the planar shape of the projecting portion 3a of the sealing plug 3 is hexagonal, and the planar shape of the insertion portion 3b into the small diameter hole 4 is circular. The head of the sealing plug 3 shown in FIG. 6 has a smooth curved surface shape or a hemispherical shape, and the head of the sealing plug 3 shown in FIG. 7 has a shape having a protrusion in the center. Therefore, alignment can be facilitated during welding.
[0023]
The circular or polygonal overhanging portion 3a provided on the head of these sealing plugs 3 is in any case an outer diameter (d1 <D <D <2) which is at least larger than the inner diameter d1 of the small diameter hole 4 and smaller than the inner diameter d2 of the counterbore groove 5. d2) and the volume of the flange portion 5b above the counterbored groove 5 (the total volume including the small-diameter holes {(d2 ² -d1 ² ) πh / 4}) or a slightly smaller volume. If the overhanging portion is made into a polygon, it is difficult to roll and easy to adjust, and the volume can be easily adjusted. Can do.
[0024]
The sealing plug 3 having the overhanging portion 3 a is injected with the electrolyte solution from the small diameter hole 4, and then the lower part 3 b of the sealing plug 3 is pushed into the lower surface of the overhanging portion 3 a and the upper surface of the flange portion 5 b around the small diameter hole 4 (cover plate The surface). Thereafter, an arc heat source is applied from the head of the sealing plug 3, and the overhang portion 3 a and the peripheral portion of the small-diameter hole 4 on the surface of the lid plate 2 are sealed and welded.
[0025]
As described above, when the circular or polygonal overhanging portion 3a that can be melted in a short time is provided on the head of the sealing plug 3, the overhanging portion 3a of the sealing plug 3 can be easily grasped with a jig or the like and press-fitted into the small diameter hole 4. In addition to ensuring that the lower surface of the overhang portion 3a and the cover plate surface around the small-diameter hole 4 are in close contact with each other, an arc heat source is provided on the head of the sealing plug 3 protruding in a convex shape from the cover plate surface. It becomes easy to add. Further, when the circular or polygonal counterbore groove 5 is provided on the back surface side of the cover plate 2, the peripheral portion of the small-diameter hole 4 to be sealed and welded is thin, and is completely melted to the back side by arc welding performed from the front surface side. be able to. In addition, if the volume of the overhanging portion 3a is formed to be approximately the same as or slightly smaller than the volume of the flange portion 5b (thin wall portion), the volume balance with the flange portion 5b to be fused is improved, and the sealing plug is shortened in a short time. The three heads can be reliably melted and can be smoothly and integrally fused with the flanges around the small-diameter hole 4 on the surface of the cover plate.
[0026]
FIG. 8 is a cross-sectional view showing a process of sealing a small-diameter hole by a manufacturing method related to the present invention by TIG arc welding and a diagram showing a relationship between welding current and time. (1) Sealing before welding Stopper and electrode arrangement, (2) Arc heating of sealing plug head, (3) Spherical melting of sealing plug head, (4) Integrated fusion with lid plate flange, (5) Welding after welding And (6) the state of the current waveform over time. The arc heat source used in this embodiment is a TIG arc in which non-consumable tungsten is used as the electrode 12, and predetermined welding conditions (current and welding time) are set in a welding power source and output. The planar shape of the small-diameter hole 4 and the sealing plug 3 in the present embodiment can be performed by the same process in any combination of the shapes described above.
[0027]
As shown in FIG. 8 (1), the tip of the electrode 12 is positioned at the center of the head of the sealing plug 3 that is tightly inserted into the small-diameter hole 4 having the counterbore groove 5 on the back side of the lid plate 2. When welding starts, an arc 11 is generated at the head of the sealing plug 3 in the atmosphere of shielding gas (Ar gas) outflow, and the current I (A) for a predetermined time T (ms) is generated as shown in FIG. It is output. Next, as shown in FIG. 8 (2), the overhang portion 3a of the head of the sealing plug 3 is first melted by arc heating, and as shown in FIG. 8 (3), it is melted into a spherical shape by the surface tension of the molten metal. Change. Then, as shown in FIG. 8 (4), the flange portion around the small-diameter hole 4 to be heated and melted thereafter and the overhanging portion 3a of the sealing plug 3 head which has already been melted and changed into a spherical shape are integrated integrally smoothly. And can be completely melted to the back side of the cover plate 2. Furthermore, as shown in FIG. 8 (5), it is possible to obtain a welded portion 9 having a perfectly sealed surface with a smooth surface after welding and a substantially circular shape.
[0028]
FIG. 9 is a diagram showing a relationship between an appropriate time and current in sealing welding of a small-diameter hole. The planar shapes of the small-diameter hole 4 and the sealing plug 3 of this embodiment are those obtained by combining both the above-described FIGS. 2 and 4 with circles. The circles in the figure are areas with good bonding. The cover plate 2 and the sealing plug 3 are both made of aluminum, the diameter d1 of the small-diameter hole 4 is 1.4 mm, the diameter d2 of the counterbored groove 5 is 2.4 mm, and the thickness h of the flange portion 5a is about 0.3 mm. The results of the small-diameter hole sealing are shown. For example, a good weld 9 can be obtained by arc welding in a short time of about 29 ms when the current I is 90 A and about 100 ms when the current I is 40 A.
[0029]
An appropriate condition for good bonding has a correlation between the current I (A) and the time T (ms), and can be obtained by the following equation (1). However, b is a multiplier related to the melting of the joint portion of the small diameter hole 3 and varies depending on the shape and material of the peripheral portion of the small diameter hole 4 of the sealing plug 3 and the cover plate 2, and is 0.5 to 0.8. It will be about. C is a constant relating to heating of the plug head, and is in the range of about 9300 to 175000.
[0030]
I = (c / T) ^b (1)
As described above, when an arc heat source of a predetermined condition is given from the head of the sealing plug 3 for a short time and heated and melted, the overhanging portion 3a of the sealing plug 3 and the periphery of the small-diameter hole 4 on the surface of the lid plate 2 are properly aligned. The welded portion 9 can be integrally fused and completely sealed, and the welded surface 9 having a smooth surface after welding can be obtained. If the welding conditions are set based on at least a relational expression between current and welding time, appropriate conditions capable of complete sealing can be surely output, and management of welding conditions and quality control of welding become easy.
[0031]
Hole sealing welding can be satisfactorily performed by TIG arc welding shown in FIG. 8 for other stainless steel materials different from aluminum materials, such as steel materials and nickel materials. These metal materials have higher melting points than aluminum materials, but are easily melted by energization heating with a TIG arc because of their large electric resistance. Even if a plasma arc and a welding power source are used instead of hole sealing welding by TIG arc and an arc heat source is applied from the head of the sealing plug 3 to heat and melt, sealing is performed in the same manner as in TIG arc welding. The overhanging portion 3a of the stopper plug 3 and the peripheral portion of the small-diameter hole 4 on the surface of the cover plate 2 can be appropriately integrally fused and completely sealed, and a welded portion having a smooth surface after welding can be obtained. . Since plasma arc welding is protected by the plasma gas flowing out from the nozzle and nozzle hole on the outer periphery of the electrode, the electrode has a long life and can be used for a long time.
[0032]
FIG. 10 is a flowchart showing a manufacturing process of a prismatic battery which is an example of a sealed container related to the present invention. The battery parts manufactured and assembled 21 in the first step are accommodated 22 in the battery closed container 1. In order to seal the opening on the upper surface of the container, in the next step, after the cover plate 2 is mounted 23, the cover plate 2 is sealed and welded to the battery closed container 1 along its outer periphery by laser welding, for example. do. Thereafter, the electrolytic solution 10 is injected 25 into the battery sealed container 1 from the small-diameter hole 4 provided in the lid plate 2 in advance. The sealing plug 3 is press-fitted 27 into the small-diameter hole 4 in the next step. Finally, in order to seal the small-diameter hole 4, sealing welding 28 of the small-diameter hole 4 with an arc heat source is performed. After the sealing welding 28, the welds 8 and 9 and the liquid leakage inspection 29 are performed. It is also possible to perform sealing welding of the small-diameter hole 4 using a laser heat source instead of the arc heat source. Although not shown, cleaning and drying of the battery exterior, charging of the battery, performance test, quality inspection, and the like are further performed.
[0033]
In this way, a desired sealed container and battery that need to be sealed can be reliably produced in a series of production lines from the battery component manufacturing assembly 21 to the welded part after welding and the liquid leak inspection 29. . In particular, in the welding welding 28 for small diameter holes, arc welding is performed by outputting welding conditions capable of integrating the sealing plug overhanging portion 3a and the peripheral portion of the small diameter hole on the surface of the lid plate. It becomes a fusion form and a penetration shape different from the circumferential seal welding, and a surface having a smooth surface after welding can be obtained. In addition, since defective products are excluded and only acceptable products are selected and certified by inspection of welded portions and liquid leakage performed after welding, it is possible to reliably produce highly sealed containers and batteries.
[0034]
As described above, according to this experiment example, the overhang planar shape formed in the head of the sealing plug has a circular or polygonal, and thin portion of the small-diameter hole peripheral portion of the cover plate surfaces having the same planar shape As a result of the integrated fusion, the small-diameter hole can be easily melted with a small amount of energy in a short time, and can be completely sealed reliably. Furthermore, a high-quality welded portion having a smooth surface and no defects can be obtained, and a hermetically sealed container with little variation can be manufactured.
[0035]
( Example )
FIG. 11 is a perspective view of a sealed container that houses the non-battery components of the present invention. Examples of housing parts in the present embodiment include a small-diameter container containing electronic parts, a sealed container containing sensor parts, and a sealed container containing fine mechanical parts. The small-diameter hole 4 is provided on the metal cover plate 2 surface at the top of these closed container 1, sealing by inserting a sealing plug 3 to seal the small holes 4 as with real Kenrei Can be welded. The combination of the planar shape of small-diameter hole 4 and the sealing plug 3 can be performed in the same manner as the actual Kenrei.
[0036]
FIG. 12 is a flowchart showing an embodiment of a process for sealing and welding the small-diameter hole of the sealed container shown in FIG. First, parts manufactured in another process are stored in a container, and the upper part of the container 1 is sealed with a cover plate 2 to assemble a sealed container 20. In the next step, the sealing plug 3 is press-fitted into the small-diameter hole 4 on the surface of the lid plate 2 to perform the sealing plug insertion 27b. In the next step after the sealing plug 3 is inserted, sealing welding 30 of the small-diameter hole 4 by an arc heat source or a laser heat source is performed in order to seal the small-diameter hole 4. Finally, quality inspection 31 of the welded portion 9 after sealing welding is performed. In particular, in the process of sealing welding 30 for the small-diameter hole 4, a welding condition is output that enables the fusion of the overhanging portion of the sealing plug 3 and the peripheral portion of the small-diameter hole 4 on the surface of the lid plate 2 as shown in FIG. When arc welding is performed, a welded portion having a smooth surface after welding and a high quality can be obtained. It is also possible to perform sealing welding of the small-diameter hole 4 using a laser heat source instead of arc welding. And since the defective product is excluded and only the acceptable product can be selected and certified by the quality inspection 31 of the welded portion that is performed after sealing welding, a sealed container with high hermeticity can be reliably produced.
[0037]
As described above, according to this embodiment, as in the real Kenrei, small-diameter hole of the cover plate surfaces having a projecting portion planar shape formed in the head of the sealing plug has a circular or polygonal, the same planar shape The integrated fusion with the thin portion at the periphery allows the small-diameter hole to be easily melted in a short time with a small amount of energy, and can be surely completely sealed. Furthermore, a high-quality welded portion having a smooth surface after welding and no defects can be obtained, and a hermetically sealed container with little variation can be manufactured.
[0038]
【The invention's effect】
As described above, according to the present invention, a small-diameter hole can be easily welded with a small amount of energy in a short time and can be completely sealed reliably. In addition, a high-quality welded portion having a smooth surface after welding and no defects can be obtained, and a hermetically sealed container with little variation and a manufacturing method thereof can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view of a prismatic battery which is an example of a sealed container related to the present invention.
2 is a cross-sectional view and a plan view showing an example of a sectional view and a small-diameter hole showing an example of a sealing plug that relate to the present invention.
3 is a cross-sectional view and a plan view showing another example of the small-diameter hole that relate to the present invention.
Is a plan view and a cross-sectional view showing an example of a sealing plug that relate to the present invention; FIG.
5 is a plan view and a cross-sectional view showing another example of Rufutomesen related to the present invention.
It is a cross-sectional view showing another example of the sealing stopper and the small-diameter hole that relate to the present invention; FIG.
7 is a sectional view showing another example of the sealing stopper and the small-diameter hole that relate to the present invention.
[8] The small-diameter hole that relate to the present invention by TIG arc welding is a sectional view of the sealing stopper and the small-diameter hole showing a step of sealing.
9 is a diagram showing a relationship between the welding time and the current in the sealing weld of the small-diameter hole that relate to the present invention.
FIG. 10 is a flowchart showing a manufacturing process of a prismatic battery which is an example of a sealed container related to the present invention.
FIG. 11 is a perspective view showing another example of a sealed container according to the present invention.
FIG. 12 is a flowchart showing a manufacturing process for sealing and welding a small-diameter hole of another example of a sealed container according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sealed container, 2 ... Cover plate, 3 ... Sealing plug, 3a ... Overhang | projection part, 3b ... Insertion part, 4 ... Small-diameter hole, 5 ... Counterbore groove, 5a ... Collar part, 6 ... Insulation packing, 7 ... Negative electrode terminal , 8... Welded portion on the outer periphery of the cover plate, 9... Welded portion sealed with a small diameter hole, 11.

Claims

A sealed container having a metal container in which a non-battery component is housed, a lid plate that seals an opening of the container, and a sealing plug that seals a small-diameter hole provided in the lid plate; The back surface of the plate has a thin-walled portion in which the outer peripheral portion of the small-diameter hole has a planar shape that is circular or polygonal, and the sealing plug has a protruding portion that is planar or circular or polygonal in its head. The sealed container, wherein the small-diameter hole is sealed by welding the thin-walled portion and the sealing plug.

A sealed container having a metal container in which a non-battery component is housed, a lid plate that seals an opening of the container, and a sealing plug that seals a small-diameter hole provided in the lid plate; The back surface of the plate has a thin-walled portion in which the outer peripheral portion of the small-diameter hole has a planar shape that is circular or polygonal, and the sealing plug has a protruding portion that is planar or circular or polygonal in its head. The closed container, wherein the small-diameter hole is sealed by welding the overhanging portion of the sealing plug and the thin-walled portion.

3. The small-diameter hole according to claim 1, wherein the small-diameter hole has a circular or polygonal planar shape, and the sealing plug has a circular shape having a diameter larger than the diameter of the small-diameter hole or a polygon having a width larger than the diameter of the small-diameter hole. The projecting portion and a planar or circular insertion portion that is inserted into the small-diameter hole have a circular shape or a polygonal shape, and the projecting portion has a volume equal to or more than the volume of the space formed by the thin portion of the lid plate. A sealed container having a small volume.

In a method for manufacturing a sealed container, the opening of a metal container containing non-battery parts is sealed with a cover plate, and then the small-diameter hole provided in the cover plate is sealed with a sealing plug. A thin-walled portion that is circular or polygonal in a planar shape is formed on the outer peripheral portion of the small-diameter hole on the back surface side, and a protruding portion that is circular or polygonal in a planar shape is formed on the head of the sealing plug , and the thin-walled portion A method for manufacturing a sealed container, wherein the small-diameter hole is sealed by welding between a portion and the sealing plug.

In a method for manufacturing a sealed container, the opening of a metal container containing non-battery parts is sealed with a cover plate, and then the small-diameter hole provided in the cover plate is sealed with a sealing plug. A thin-walled portion that is circular or polygonal in a planar shape is formed on the outer peripheral portion of the small-diameter hole on the back surface side, and a protruding portion that is circular or polygonal in a planar shape is formed on the head of the sealing plug, and the protruding portion The small-diameter hole is sealed by welding the portion and the thin portion of the lid plate.

6. The process according to claim 4, wherein the step of inserting the sealing plug into the small-diameter hole, the step of melting the sealing plug with an arc heat source or a laser heat source and welding, and inspecting the welded portion after the sealing. The manufacturing method of the airtight container characterized by having an inspection process to do.

In claim 4, the welding performed by TIG arc welding or plasma arc welding with non-consumable electrodes, the current I (A) and welding time in the arc welding T (ms) and the following ( 1) A method for producing a sealed container, which is set based on the formula.
I = (c / T) ^b (1)
(Where, b is a constant number relating to the melting of the joint portion, c is a constant relating to heat the plug head)