JP3750032B2

JP3750032B2 - Structure having cross joint and method for assembling and manufacturing the same

Info

Publication number: JP3750032B2
Application number: JP30142596A
Authority: JP
Inventors: 貴祐横山; 武和田
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1996-11-13
Filing date: 1996-11-13
Publication date: 2006-03-01
Anticipated expiration: 2016-11-13
Also published as: JPH10142386A

Description

【０００１】
【発明の属する技術分野】
本発明は十字継手を有する構造物およびその組立製造方法に係り、特に、ボロン入りステンレス鋼板のように、伸びの少ない板を組合せ溶接する板構造に好適な十字継手を有する構造物およびその組立製造方法に関する。
【０００２】
【従来の技術】
従来、使用済燃料貯蔵ラックなど、十字継手を有する構造物の溶接組立方法は、例えば特開平５−８０１８９号公報記載の例がある。便宜的に図２を参照して説明すると、長尺仕切板３Ａ〜３Ｅと、下側より挿入する短尺仕切板２Ａ〜２Ｅとを栓溶接で一体化している。
【０００３】
【発明が解決しようとする課題】
このような栓溶接では溶着量が多くなり、溶着収縮応力が大きくなるという問題があった。さらに、栓溶接端部で溶接応力集中が起きるとともに、端部では溶接応力の変化が激しいので、局部的に大きく伸ばされる。この結果、高ボロン入りステンレス鋼のように伸びのない材料では、割れが発生するという欠点があった。
本発明の目的は、高ボロン入りのステンレス鋼のように、伸びの少ない材料を用いた格子状の継手を有する十字継手の溶接において、溶着量、溶接収縮力を減らし、また切り込み孔端部での応力集中を減らし、溶接ビード端部の溶接応力の変化を減らすことのできる十字継手を有する構造物およびその組立製造方法を提供することである。
【０００４】
【課題を解決するための手段】
上記目的を達成するために、本発明の特徴は、例えば高ボロン入りステンレス鋼のように、伸びの少ない材料を用いた格子状継手を有するラック等の構造物の溶接割れを防止する手段として、下側から挿入した突起部と長尺仕切板との突合せ溶接において、開先深さを板厚の２／３を超えないようにするとともに、長尺仕切板の上に設置する短尺仕切板との隅肉溶接において、脚長を板厚の２／３を超えないようにして溶接応力を小さくする。さらに、突合せ溶接のビード端部と隅肉溶接のビード端部を一致させずにずらすことにより、溶接応力の発生を急激に変化させないようにして溶接ビード割れの発生を防ぐとともに、さらに、長尺仕切板の切り込み孔のコーナ部から、上記突合せ溶接と隅肉溶接の終始端部をはずして、切り込み孔のコーナ部にかかる応力を漸減し、コーナ部に発生する割れを防止するようにした。
以下に、各請求項記載発明について説明する。
請求項１記載発明は、長尺仕切板に設けた切り込み孔に、短尺仕切板の突起部を挿入し、さらにその上に第２の短尺仕切板を載置し、順次溶接して組み立てた十字継手を有する構造物において、前記長尺仕切板と前記突起部との突合せ溶接の終始端部と、前記長尺仕切板と前記第２の短尺仕切板との隅肉溶接の終始端部とが、前記切り込み孔のコーナ部とずれて重複していないことを特徴とするものである。本構造物によれば、応力集中しやすい切り込み孔のコーナ部と、溶接の終始端部とが、ずれて一致していないので、切り込み孔のコーナ部での応力集中が減少し、溶接割れのない板構造の燃料ラック等を得られる。
また、請求項２記載発明は、長尺仕切板に複数の切り込み孔を設け、この切り込み孔に挿入できる突起部を短尺仕切板に設け、前記切り込み孔へ前記突起部を下側より挿入して組み立てたのち突合せ溶接を行い、次いで、上側より第２の短尺仕切板を設置して前記長尺仕切板との間で隅肉溶接を行ない、長尺仕切板と短尺仕切板とを格子状に組合せて製造する十字継手を有する構造物の組立製造方法において、前記長尺仕切板と前記突起部との突合せ溶接の終始端部を、前記切り込み孔のコーナ部から離して溶接し、次いで、前記長尺仕切板と前記第２の短尺仕切板との間の隅肉溶接の終始端部を、前記コーナ部から離して溶接するようにしたことを特徴とする。本方法によれば、長尺仕切板に設けた切り込み孔のコーナ部と、突合せ溶接あるいは隅肉溶接の終始端部とが重ならないので、溶接割れをなくすことができる。
また、請求項３記載発明は、前記突合せ溶接の開先深さを、前記長尺仕切板の板厚の２／３を超えないで、かつ前記隅肉溶接の脚長以上、すなわち脚長を突合せ溶接の開先深さ以下とし、前記隅肉溶接の脚長を、前記長尺仕切板の板厚の２／３を超えない脚長としたことを特徴とするので、突合せ溶接部の単位当りの溶着量を減らす一方で、隅肉溶接の脚長も小さくして溶接収縮力を軽減し、溶接割れを抑えることができる。
また、請求項４記載発明は、前記隅肉溶接と前記突合せ溶接のそれぞれの端部を、一致させないようにずらしたことを特徴とするので、溶接端部の溶接収縮力が急激に変化しないため、溶接割れの発生を防ぐことができる。
また、請求項５記載発明は、前記切り込み孔の両端コーナ部と、前記切り込み孔に挿入された突起部との間に、所定間隔の隙間を有することを特徴とするので、突起部の突合せ溶接とコーナ部とが重複しないため、コーナ部の溶接割れを防ぐことができる。
また、請求項６記載発明は、前記長尺仕切板の突起部は、根本に所定Ｒ以上の丸みを形成したことを特徴とするので、突起部根本の割れを防止でき、十字継手を有する構造物の構造強度を向上させることができる。
【０００５】
【発明の実施の形態】
以下、本発明の実施形態を、図面を参照して説明する。
図１および図２は、十字継手を有する板構造の燃料ラック組立図である。図１は、本実施形態の板構造ラックの全体斜視図、図２は、図１に示す板構造ラックのＡ−Ａ断面図である。これらの図に示すように、板構造ラックはシート１に長尺仕切底板１１を水平に設置し、次にその長尺仕切底板１１上に短尺仕切板２Ａを垂直に設置する。次にその短尺仕切板２Ａの上に長尺仕切板３Ａを設置する。長尺仕切板３Ａには切り込み孔１５をあらかじめ設けておき、短尺仕切板２Ａには突起部４を設けてある。長尺仕切板３Ａと短尺仕切板２Ａの組合せは、短尺仕切板２Ａに設けてある突起部４を、長尺仕切板３Ａに設けてある切り込み孔１５に差し込み格子状に組み合わせる。
【０００６】
図２に示すように、短尺仕切板２Ｂ〜２Ｅにも、短尺仕切板２Ａと同様に、突起部４が設けられ、また、長尺仕切板３Ｂ〜３Ｄにも、長尺仕切板３Ａと同様に、切り込み孔１５が設けてある。そして、組立てに際しては、短尺仕切板２Ｂ〜２Ｅの突起部４を、長尺仕切板３Ｂ〜３Ｄの切り込み孔１５に差し込んで格子状に組合せる。
【０００７】
ここで、参考までに、従来のラックの溶接部について説明する。図１２〜図１７は、従来の溶接部形状を説明するための図である。
図１２は、図２のＡ部について、従来の組立方法を示す詳細図である。鉛直に設置した短尺仕切板２Ｃの突起１４を浅く形成し、水平の長尺仕切板３Ｃの切り込み孔１５に開先（栓溶接）９を設定し、溶着金属１０で埋めている。
図１３〜図１５は、図１２のＥ−Ｅ断面である。図１３は、長尺仕切板３Ｃの切り込み孔１５に、短尺仕切板２Ｃの突起部１４を差し込んでいる。それにより開先９が形成されたものである。
図１４は、開先９を栓溶接して溶着金属１０が形成され、その形成された溶着金属１０の上方に、短尺仕切板２Ｄをセットした状態を示す。
図１５は、短尺仕切板２Ｄと長尺仕切板３Ｃの隅肉溶接１０を行った溶接部断面を示す。
【０００８】
図１６は、図１５のＦ−Ｆ断面を示す。図１５のＦ−Ｆ断面は、栓溶接９が実施されている。栓溶接９は、矩形で板厚相当の溶接が行なわれるので溶着量が多くなり、溶接収縮応力も大きくなる。また、切り込み孔１５の端部まで溶接されるため端部のコーナ部では応力集中が発生しやすくなる。
図１７は、図１６のＧ−Ｇ断面である。図１７では、栓溶接９の端部が、切り込み孔１５の溶接応力の発生しやすいコーナ部１６では、母材割れ１２及び溶接ビード割れ１３が発生している。
【０００９】
上記のように、この従来の方法では、長尺仕切板３Ｃに設けてある切り込み孔１５と、短尺仕切板２Ｃで形成された開先９を、栓溶接する状況になるために、溶着量が多くなり、この結果、溶接収縮力が大きくなる。しかも、溶接は、応力集中の発生しやすい切り込み孔１５のコーナ部１６まで溶接される。そのため、結果として、切り込み孔１５のコーナ部１６を起点として、母材割れ１２あるいは溶接ビード割れ１３が発生する欠点があった。
【００１０】
次に、図３〜図８を用いて、本発明の板構造の燃料ラックについて述べる。
図３は、図２のＡ部の詳細図である。水平に設置した長尺仕切板３Ｃに設けてある切り込み孔１５に、短尺仕切板２Ｃに設けてある突起部４を挿入し、格子状に組合せている。本実施形態では、突起部４は従来より高さを高くし、切り込み孔１５の両端コーナ部１６との間に、所定の隙間１７を設けている。また、突起部４の根本には、図中に点線で示すように、例えば１Ｒ程度の所定の丸み１８を形成することにより、組立強度を向上させることができる。
【００１１】
図４、図５、図６は、図３のＢ−Ｂ断面である。図４は、長尺仕切板３Ｃと短尺仕切板２Ｃの組立を示す。長尺仕切板３Ｃに設けられた切り込み孔１５には開先５が設けられ、また、短尺仕切板２Ｃには突起部４が設けられ、切り込み孔１５に差し込み、組み合わせて突合せ溶接ができるようにしてある。開先５の開先深さ、および長尺仕切板３Ｃと短尺仕切板２Ｄの隅肉溶接７の脚長は、溶着量を増加させないため、また、溶接応力の増加を防ぐために、板厚の２／３以下になるように寸法を決定し、強度不足に対しては、溶接長を長くするようにしてある。一方、長尺仕切板３Ｃとそれに垂直に載せる短尺仕切板２Ｄとの間の隅肉溶接７の脚長より開先５の深さを小さくすると、隅肉溶接７の収縮応力により、図１１に示すように、溶接部に割れ１９が発生する。このため、開先５の深さの下限は、隅肉溶接７の脚長以上にするようにした。
【００１２】
図５は、図４の長尺仕切板３Ｃに設けた開先５を、短尺仕切板２Ｃの突起部４と突合せ溶接６を行ない、その後、上方より短尺仕切板２Ｄをセットした状態を示す。
図６は、長尺仕切板３Ｃと、上方よりセットされる短尺仕切板２Ｄの隅肉溶接７を示すもので、隅肉溶接７の脚長は、短尺仕切板２Ｄおよび長尺仕切板３Ｃの板厚の２／３を超えないようにして、溶着断面積が小さくなるようにしてある。突合せ溶接６、隅肉溶接７の反対側は、強度上不足する場合で、必要ならば、隅肉溶接８を実施してもよい。
【００１３】
図７は図６のＣ−Ｃ断面で、図８は図７のＤ−Ｄ断面である。切り込み孔１５と突起部４との突合せ溶接６、および隅肉溶接７とには、溶接の影響を受けない隙間１７を３ｍｍ程度設け、切り込み孔１５の応力集中の発生しやすい端部コーナ１６に、溶接応力が直接作用しないようにし、応力集中しやすい切り込み孔１５のコーナ１６に割れが発生しないようにした。突合せ溶接６の溶着断面積の減少による強度不足については、突起部４の水平な長手方向の長さを長くし、溶接部全体強度を上げさせて確保するようにした。さらに、強度上不足する場合で、必要ならば、隅肉溶接７の反対側に隅肉溶接８を実施することもできる。
【００１４】
このように本発明では、長尺仕切板３に設けた切り込み孔１５の開先５の深さ、および隅肉溶接７の脚長は、いずれも板厚の２／３を超えず、しかも、隅肉溶接７の脚長を開先５の深さ以内にしてある。さらに、突合せ溶接６は切り込み孔１５の端部から３ｍｍ以上離すことで、応力集中の発生しやすい切り込み孔１５のコーナ部への溶接収縮力の影響を避けられ、応力集中を避けることができる。この結果、高ボロン材においても割れの発生しない溶接方法を提供できる。
【００１５】
図９は、本発明の他の実施形態を示す。本実施形態が図７の実施形態と異なるところは、長尺仕切板３Ｃと上方の短尺仕切板２Ｄの隅肉溶接７Ｃを、切り込み孔１５の長手方向の長さより大きくして、溶接端部を切り込み孔１５端部のコーナ１６より外側に外していることである。この方法では、突合せ溶接の端部と隅肉溶接の端部を一致させないようにし、また、溶接応力の分布の変化が発生しやすい溶接部端部が切り込み孔端部より離れるようにしている。このように切り込み孔１５端部で溶接ビードを止めていないので割れは起きない。
【００１６】
図１０は、本発明のさらに他の実施形態を示す。本実施形態が図７の実施形態と異なるところは、突合せ溶接６の長さより隅肉溶接７を短くしてある。突合せ溶接６の端部と隅肉溶接７端部を一致させないようにして、ビードの終始端部に発生する応力が急激に変化させないようにしてある。そのため、切り込み孔１５の端部に応力集中せずに、溶接端部に応力変化を大きくさせないので、応力が分散し割れが発生しない。
【００１７】
以上説明したように、これらの実施形態における特徴は、例えば高ボロン入りステンレス鋼のように、伸びの少ない材料を用いた格子状継手を有するラック等の構造物の溶接割れを防止する手段として、下側から挿入した突起部と長尺仕切板との突合せ溶接の開先深さと、長尺仕切板とその上に設置する短尺仕切板との隅肉溶接の脚長とを、それぞれ板厚の２／３を超えないようにし、かつ隅肉溶接の脚長を突合せ溶接の開先深さ以内として溶接応力を小さくする。さらに、突合せ溶接のビード端部と隅肉溶接のビード端部を一致させずにずらすことにより、溶接応力の発生を急激に変化させないようにして溶接ビード割れの発生を防ぐとともに、さらに、長尺仕切板の切り込み孔のコーナ部から、上記突合せ溶接と隅肉溶接の終始端部を外して、切り込み孔のコーナ部にかかる応力を漸減し、コーナ部に発生する割れを防止するようにした。
【００１８】
すなわち、図３以下に示すように、本発明における十字継手を有する燃料ラック等の構造物は、長尺仕切板３Ｃに設けた切り込み孔１５に、短尺仕切板２Ｃの突起部４を挿入し、さらにその上に上側の短尺仕切板２Ｄを載置し、順次溶接して組み立てた十字継手を有する構造物において、長尺仕切板２Ｃと突起部４との突合せ溶接６の終始端部と、長尺仕切板２Ｃと上側の短尺仕切板２Ｄとの隅肉溶接７の終始端部とが、切り込み孔１５のコーナ部１６とずれて重複していないことを特徴とし、それにより、切り込み孔１５のコーナ部１６と、溶接の終始端部とが、ずれて一致していないので、コーナ部１６での応力集中が減少し、溶接割れのない板構造の燃料ラック等を得られるのである。
【００１９】
また、本発明における溶接組立方法は、長尺仕切板３Ｃと突起部４との突合せ溶接６の終始端部を、切り込み孔１５のコーナ部１６から離して溶接し、次いで、長尺仕切板３Ｃと上側の短尺仕切板２Ｄとの間の隅肉溶接７の終始端部を、コーナ部１６から離して溶接するようにしたので、長尺仕切板３Ｃに設けた切り込み孔１５のコーナ部１６と、突合せ溶接６あるいは隅肉溶接７の終始端部とが重ならないので、溶接割れをなくすことができる。この場合、突合せ溶接６の開先５の深さと隅肉溶接７の脚長とを、それぞれ長尺仕切板３Ｃの板厚の２／３を超えないようにし、かつ隅肉溶接７の脚長を開先５の深さ以内に抑えたので、単位当りの溶着量を減らして溶接収縮力を軽減し、溶接割れを抑えることができる。また、隅肉溶接７と突合せ溶接６のそれぞれの端部をずらしたので、溶接端部の溶接収縮力が急激に変化しないため、溶接割れの発生を防ぐことができる。また、切り込み孔１５の両端コーナ部１６と突起部４との間に、３ｍｍ以上の隙間を設けたので、突合せ溶接６とコーナ部１６とが重複しないため、コーナ部１６の溶接割れを防ぐことができる。また、長尺仕切板３Ｃの突起部４は、根本に少なくとも１Ｒ以上の丸み１８を形成すると、突起部根本の割れを防止でき、十字継手を有する構造物の構造強度を向上させることができる。
【００２０】
以上の如く、これらの実施形態によれば、従来ラックの継手では溶着量が多いので溶接応力が発生し割れを引き起こしていたが、高ボロンの格子状の板構造ラックなどの継手では溶着量を増加させないため、および溶接応力の増加を防ぐために、突合せ溶接および隅肉溶接の寸法を規制し、さらに、溶着断面積の減少による強度不足については、突起部の長さを長くし、単位当りの溶接収縮力を増加させずに強度を上げさせ確保するようにした。また、強度上不足する場合で必要ならば隅肉溶接の反対側に隅肉溶接を実施することで割れの発生しない継手を提供することができる。
【００２１】
【発明の効果】
本発明によれば、例えば、高ボロン入りのステンレス鋼のように、伸びの少ない材料を用いた格子状の継手を有する十字継手を有する構造物およびその組立製造方法において、突合せ溶接および隅肉溶接の寸法を規制することにより、溶接の溶着量や溶接収縮力を減らし、また切り込み孔端部での応力集中を減らし、溶接ビード端部の溶接応力の変化を減らすことができる。
【図面の簡単な説明】
【図１】本発明の一実施形態を示す板構造燃料ラックの組立図。
【図２】図１のＡ−Ａ矢視図。
【図３】図２のＡ部拡大図。
【図４】図３のＢ−Ｂ矢視図。
【図５】図４の突合せ溶接を示す断面図。
【図６】図５の隅肉溶接を示す断面図。
【図７】図６のＣ−Ｃ矢視図で、突合せ溶接と隅肉溶接を示す側面図。
【図８】図７のＤ−Ｄ矢視図で、突合せ溶接と隅肉溶接を示す上面図。
【図９】本発明の他の実施形態の突合せ溶接と隅肉溶接を示す上面図。
【図１０】本発明のさらに他の実施形態の突合せ溶接と隅肉溶接を示す上面図。
【図１１】突合せ溶接と隅肉溶接における収縮応力による割れを示す図。
【図１２】本発明の図３に相当する従来型燃料ラックの溶接部拡大図。
【図１３】図１２のＥ−Ｅ矢視図。
【図１４】図１３の栓溶接を示す断面図。
【図１５】図１４の隅肉溶接を示す断面図。
【図１６】図１５のＦ−Ｆ矢視図。
【図１７】図１６のＧ−Ｇ矢視図。
【符号の説明】
１板構造燃料ラックベース板
２、２Ａ、２Ｂ、２Ｃ、２Ｄ、２Ｅ短尺仕切板
３、３Ａ、３Ｂ、３Ｃ、３Ｄ長尺仕切板
４突起部
５長尺仕切板開先
６突合せ溶接
７隅肉溶接
８裏溶接
９栓溶接
１０栓溶接溶着金属
１１長尺仕切底板
１２切り込み孔のコーナ部より発生する母材割れ
１３溶接ビードに発生する割れ
１４従来の突起部
１５切り込み孔
１６切り込み孔のコーナ部
１７隙間
１８丸み
１９溶接部の収縮応力割れ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure having a cruciform joint and a method for assembling and manufacturing the structure, and more particularly to a structure having a cruciform joint suitable for a plate structure for combining and welding plates having low elongation, such as a stainless steel sheet containing boron. Regarding the method.
[0002]
[Prior art]
Conventionally, as a method for welding and assembling a structure having a cross joint such as a spent fuel storage rack, there is an example described in JP-A-5-80189. If it demonstrates with reference to FIG. 2 for convenience, the long partition plates 3A-3E and the short partition plates 2A-2E inserted from the lower side are integrated by plug welding.
[0003]
[Problems to be solved by the invention]
In such plug welding, there is a problem that the amount of welding increases and the welding shrinkage stress increases. Further, the welding stress concentration occurs at the end portion of the plug weld, and the change in the welding stress is severe at the end portion, so that it is greatly extended locally. As a result, a material that does not stretch, such as high-boron stainless steel, has a drawback of causing cracks.
The object of the present invention is to reduce the amount of welding and welding shrinkage force in the welding of a cruciform joint having a lattice-like joint using a material with low elongation, such as stainless steel containing high boron. It is an object to provide a structure having a cruciform joint and a method for assembling and manufacturing the structure, which can reduce the stress concentration of the weld bead and change the welding stress at the end of the weld bead.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the feature of the present invention is, for example, as a means for preventing weld cracking of a structure such as a rack having a lattice joint using a material having low elongation, such as high-boron stainless steel. In the butt welding of the protruding portion inserted from the lower side and the long partition plate, the groove depth should not exceed 2/3 of the plate thickness, and the short partition plate installed on the long partition plate; In the fillet welding, the welding stress is reduced so that the leg length does not exceed 2/3 of the plate thickness. Furthermore, by shifting the butt weld bead end and fillet weld bead end without matching, it prevents the occurrence of weld bead cracking by preventing abrupt changes in the generation of welding stress, The end portion of the butt welding and fillet weld was removed from the corner portion of the notch hole of the partition plate, and the stress applied to the corner portion of the notch hole was gradually reduced to prevent cracks occurring in the corner portion.
The invention described in each claim will be described below.
The invention according to claim 1 is a cross formed by inserting a projection of a short partition plate into a cut hole provided in the long partition plate, placing a second short partition plate thereon, and sequentially welding it. In the structure having a joint, an end portion of the butt welding between the long partition plate and the protruding portion, and an end portion of the fillet weld between the long partition plate and the second short partition plate are The corners of the cut holes are not shifted and overlapped. According to this structure, the corner portion of the notch hole where the stress is likely to concentrate and the starting end portion of the welding are not shifted and do not coincide with each other. It is possible to obtain a fuel rack with no plate structure.
According to a second aspect of the present invention, a plurality of cut holes are provided in the long partition plate, a protrusion that can be inserted into the cut hole is provided in the short partition plate, and the protrusion is inserted into the cut hole from below. After assembling, butt welding is performed, then a second short partition plate is installed from the upper side and fillet welding is performed between the long partition plate and the long partition plate and the short partition plate in a lattice shape. In the method of assembling and manufacturing a structure having a cross joint manufactured in combination, the starting end of the butt welding between the long partition plate and the protrusion is welded away from the corner of the cut hole, and then The fillet weld starting end portion between the long partition plate and the second short partition plate is welded away from the corner portion. According to this method, since the corner portion of the cut hole provided in the long partition plate does not overlap with the starting end portion of the butt welding or fillet welding, the weld crack can be eliminated.
The invention according to claim 3 is that the groove depth of the butt welding does not exceed 2/3 of the plate thickness of the long partition plate and is not less than the leg length of the fillet weld, that is, the leg length is butt welded. The groove depth is less than the groove depth, and the leg length of the fillet weld is a leg length not exceeding 2/3 of the plate thickness of the long partition plate. On the other hand, the leg length of fillet welding can be reduced to reduce the welding shrinkage and suppress weld cracking.
The invention according to claim 4 is characterized in that the end portions of the fillet weld and the butt weld are shifted so as not to coincide with each other, so that the welding shrinkage force of the weld end portion does not change abruptly. The occurrence of weld cracks can be prevented.
The invention according to claim 5 is characterized in that there is a gap at a predetermined interval between the corner portions at both ends of the cut hole and the protrusions inserted into the cut holes. Since the corner portion does not overlap with the corner portion, it is possible to prevent weld cracks in the corner portion.
Further, the invention according to claim 6 is characterized in that the protrusion of the long partition plate is formed with a roundness of a predetermined R or more at the root, so that the root of the protrusion can be prevented and a structure having a cross joint is provided. The structural strength of the object can be improved.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
1 and 2 are fuel rack assembly diagrams of a plate structure having a cross joint. FIG. 1 is an overall perspective view of the plate structure rack of the present embodiment, and FIG. 2 is a cross-sectional view taken along line AA of the plate structure rack shown in FIG. As shown in these drawings, in the plate structure rack, the long partition bottom plate 11 is horizontally installed on the sheet 1, and then the short partition plate 2 A is vertically installed on the long partition bottom plate 11. Next, the long partition plate 3A is installed on the short partition plate 2A. The long partition plate 3A is provided with a cut hole 15 in advance, and the short partition plate 2A is provided with a protrusion 4. In the combination of the long partition plate 3A and the short partition plate 2A, the protrusions 4 provided on the short partition plate 2A are inserted into the slits 15 provided on the long partition plate 3A and combined in a lattice pattern.
[0006]
As shown in FIG. 2, the short partition plates 2 B to 2 E are also provided with protrusions 4 similarly to the short partition plate 2 A, and the long partition plates 3 B to 3 D are also similar to the long partition plate 3 A. In addition, a cut hole 15 is provided. And in the case of an assembly, the projection part 4 of the short partition plates 2B-2E is inserted in the notch hole 15 of long partition plates 3B-3D, and is combined in a grid | lattice form.
[0007]
Here, for reference, a welded portion of a conventional rack will be described. 12-17 is a figure for demonstrating the conventional welding part shape.
FIG. 12 is a detailed view showing a conventional assembling method for part A in FIG. The projection 14 of the short partition plate 2 C installed vertically is formed shallowly, and a groove (plug welding) 9 is set in the cut hole 15 of the horizontal long partition plate 3 C and is filled with the weld metal 10.
13 to 15 are cross sections taken along the line EE of FIG. In FIG. 13, the protrusion 14 of the short partition plate 2 C is inserted into the cut hole 15 of the long partition plate 3 C. As a result, the groove 9 is formed.
FIG. 14 shows a state in which the weld 9 is formed by plug welding the groove 9 and the short partition plate 2 D is set above the formed weld metal 10.
FIG. 15 shows a cross section of a welded part in which fillet welding 10 is performed between the short partition plate 2D and the long partition plate 3C.
[0008]
FIG. 16 shows an FF cross section of FIG. The plug weld 9 is implemented in the FF cross section of FIG. Since the plug weld 9 is rectangular and welds corresponding to the plate thickness are performed, the amount of welding increases, and the welding shrinkage stress also increases. Further, since welding is performed up to the end portion of the cut hole 15, stress concentration is likely to occur at the corner portion of the end portion.
17 is a GG cross section of FIG. In FIG. 17, the base metal crack 12 and the weld bead crack 13 are generated at the corner portion 16 where the end portion of the plug weld 9 is likely to generate the welding stress of the cut hole 15.
[0009]
As described above, in this conventional method, since the notch hole 15 provided in the long partition plate 3C and the groove 9 formed by the short partition plate 2C are plug welded, the welding amount is small. As a result, the welding shrinkage force increases. In addition, the welding is performed up to the corner 16 of the cut hole 15 where stress concentration is likely to occur. Therefore, as a result, there is a defect that the base material crack 12 or the weld bead crack 13 is generated starting from the corner portion 16 of the cut hole 15.
[0010]
Next, the plate structure fuel rack of the present invention will be described with reference to FIGS.
FIG. 3 is a detailed view of part A of FIG. The protrusions 4 provided on the short partition plate 2C are inserted into the slits 15 provided on the long partition plate 3C installed horizontally, and are combined in a lattice shape. In the present embodiment, the protrusion 4 has a higher height than the conventional one, and a predetermined gap 17 is provided between the corner portions 16 at both ends of the cut hole 15. Further, as shown by a dotted line in the drawing, for example, a predetermined roundness 18 of about 1R can be formed at the root of the protrusion 4 to improve the assembly strength.
[0011]
4, FIG. 5 and FIG. 6 are BB cross sections of FIG. FIG. 4 shows assembly of the long partition plate 3C and the short partition plate 2C. A groove 5 is provided in the cut hole 15 provided in the long partition plate 3C, and a protrusion 4 is provided in the short partition plate 2C so that the butt welding can be performed by being inserted into the cut hole 15 and combined. It is. The groove depth of the groove 5 and the leg length of the fillet weld 7 between the long partition plate 3C and the short partition plate 2D do not increase the welding amount, and in order to prevent an increase in welding stress, The dimension is determined so as to be equal to or less than / 3, and the welding length is increased for insufficient strength. On the other hand, when the depth of the groove 5 is made smaller than the leg length of the fillet weld 7 between the long partition plate 3 C and the short partition plate 2 D placed perpendicularly thereto, the shrinkage stress of the fillet weld 7 shows the result shown in FIG. Thus, the crack 19 occurs in the welded part. For this reason, the lower limit of the depth of the groove 5 is set to be not less than the leg length of the fillet weld 7.
[0012]
FIG. 5 shows a state in which the groove 5 provided in the long partition plate 3C of FIG. 4 is subjected to butt welding 6 with the projection 4 of the short partition plate 2C, and then the short partition plate 2D is set from above.
FIG. 6 shows the fillet weld 7 of the long partition plate 3C and the short partition plate 2D set from above. The leg length of the fillet weld 7 is the plate of the short partition plate 2D and the long partition plate 3C. The welding cross-sectional area is made small so as not to exceed 2/3 of the thickness. The opposite side of butt weld 6 and fillet weld 7 is a case where the strength is insufficient, and fillet weld 8 may be performed if necessary.
[0013]
7 is a CC cross section of FIG. 6, and FIG. 8 is a DD cross section of FIG. The butt weld 6 and the fillet weld 7 between the cut hole 15 and the protrusion 4 are provided with a clearance 17 of about 3 mm which is not affected by the welding, and the end corner 16 is prone to stress concentration in the cut hole 15. The welding stress is prevented from acting directly, and the corner 16 of the cut hole 15 where stress is easily concentrated is prevented from cracking. The lack of strength due to a decrease in the weld cross-sectional area of the butt weld 6 is ensured by increasing the horizontal length of the protrusion 4 and increasing the overall strength of the weld. Further, if the strength is insufficient, the fillet weld 8 can be performed on the opposite side of the fillet weld 7 if necessary.
[0014]
Thus, in the present invention, the depth of the groove 5 of the cut hole 15 provided in the long partition plate 3 and the leg length of the fillet weld 7 do not exceed 2/3 of the plate thickness. The leg length of the meat weld 7 is set within the depth of the groove 5. Furthermore, the butt weld 6 is separated from the end of the cut hole 15 by 3 mm or more, so that the influence of the welding shrinkage force on the corner portion of the cut hole 15 where stress concentration is likely to occur can be avoided and stress concentration can be avoided. As a result, it is possible to provide a welding method in which cracking does not occur even in a high boron material.
[0015]
FIG. 9 shows another embodiment of the present invention. This embodiment is different from the embodiment of FIG. 7 in that the fillet weld 7C of the long partition plate 3C and the upper short partition plate 2D is made larger than the length in the longitudinal direction of the cut hole 15, and the weld end portion is made. That is, it is removed outside the corner 16 at the end of the cut hole 15. In this method, the end of butt welding and the end of fillet weld are not matched, and the end of the weld that is likely to change the distribution of welding stress is separated from the end of the cut hole. Since the weld bead is not stopped at the end of the cut hole 15 as described above, no cracking occurs.
[0016]
FIG. 10 shows still another embodiment of the present invention. The difference between the present embodiment and the embodiment of FIG. 7 is that the fillet weld 7 is shorter than the length of the butt weld 6. The end of the butt weld 6 and the end of the fillet weld 7 are not matched so that the stress generated at the beginning and end of the bead does not change abruptly. Therefore, stress is not concentrated at the end of the cut hole 15 and stress change is not increased at the weld end, so that stress is dispersed and cracks do not occur.
[0017]
As described above, the feature in these embodiments is, for example, as a means for preventing weld cracking of a structure such as a rack having a lattice-like joint using a material with low elongation, such as high-boron stainless steel. The groove depth of the butt welding between the protruding portion inserted from the lower side and the long partition plate, and the leg length of fillet welding between the long partition plate and the short partition plate installed thereon are each 2 / 3 and the fillet weld leg length is within the butt weld groove depth to reduce the welding stress. Furthermore, by shifting the butt weld bead end and fillet weld bead end without matching, it prevents the occurrence of weld bead cracking by preventing abrupt changes in the generation of welding stress, The end portion of the butt welding and fillet weld was removed from the corner portion of the notch hole of the partition plate, and the stress applied to the corner portion of the notch hole was gradually reduced to prevent cracks occurring in the corner portion.
[0018]
That is, as shown in FIG. 3 and subsequent figures, in a structure such as a fuel rack having a cross joint according to the present invention, the protrusion 4 of the short partition plate 2C is inserted into the cut hole 15 provided in the long partition plate 3C. Furthermore, in a structure having a cross joint that is mounted by sequentially placing the upper short partition plate 2D on the upper short partition plate 2D, the end portion of the butt weld 6 between the long partition plate 2C and the protrusion portion 4 The end portion of the fillet weld 7 between the shank partition plate 2C and the upper short partition plate 2D is not shifted and overlapped with the corner portion 16 of the cut hole 15, Since the corner portion 16 and the starting end portion of the welding are shifted and do not coincide with each other, the stress concentration at the corner portion 16 is reduced, and a plate-like fuel rack or the like having no weld cracks can be obtained.
[0019]
In the welding assembly method according to the present invention, the starting end portion of the butt weld 6 between the long partition plate 3C and the protruding portion 4 is welded away from the corner portion 16 of the cut hole 15, and then the long partition plate 3C. Since the starting end portion of the fillet weld 7 between the upper partition plate 2D and the upper short partition plate 2D is welded away from the corner portion 16, the corner portion 16 of the cut hole 15 provided in the long partition plate 3C and Since the butt weld 6 or the fillet weld 7 does not overlap with the beginning and end portions, weld cracks can be eliminated. In this case, the depth of the groove 5 of the butt weld 6 and the leg length of the fillet weld 7 do not exceed 2/3 of the thickness of the long partition plate 3C, respectively, and the leg length of the fillet weld 7 is opened. Since it is suppressed within the depth of the tip 5, the amount of welding per unit can be reduced, the welding shrinkage force can be reduced, and weld cracking can be suppressed. Further, since the end portions of the fillet weld 7 and the butt weld 6 are shifted, the welding shrinkage force of the weld end portion does not change abruptly, so that the occurrence of weld cracks can be prevented. Further, since a gap of 3 mm or more is provided between the corner portions 16 and the projections 4 at both ends of the cut hole 15, the butt weld 6 and the corner portion 16 do not overlap with each other, so that welding cracks in the corner portion 16 are prevented. Can do. Further, when the protrusion 4 of the long partition plate 3C is formed with a round 18 of at least 1R or more at the root, the protrusion root can be prevented from cracking, and the structural strength of the structure having a cross joint can be improved.
[0020]
As described above, according to these embodiments, since the welding amount of the conventional rack joint is large, the welding stress is generated and the crack is caused. However, the joint amount of the joint such as a high boron lattice-like plate structure rack is reduced. In order to prevent an increase and to prevent an increase in welding stress, the dimensions of butt and fillet welds are regulated. The strength was increased and secured without increasing the welding shrinkage force. In addition, when the strength is insufficient, if necessary, the joint which is not cracked can be provided by performing the fillet welding on the opposite side of the fillet weld.
[0021]
【The invention's effect】
According to the present invention, for example, in a structure having a cruciform joint having a lattice-like joint using a material having low elongation, such as stainless steel containing high boron, and a method for assembling and manufacturing the structure, a butt weld and a fillet weld By restricting the dimensions of the welds, it is possible to reduce the welding amount and welding shrinkage of the weld, reduce the stress concentration at the end of the cut hole, and reduce the change in the welding stress at the end of the weld bead.
[Brief description of the drawings]
FIG. 1 is an assembly diagram of a plate-structured fuel rack showing an embodiment of the present invention.
FIG. 2 is an AA arrow view of FIG.
FIG. 3 is an enlarged view of a part A in FIG. 2;
4 is a BB arrow view of FIG. 3;
5 is a cross-sectional view showing the butt welding of FIG. 4. FIG.
6 is a cross-sectional view showing fillet welding of FIG. 5. FIG.
7 is a side view showing butt welding and fillet welding in the CC arrow view of FIG. 6;
8 is a top view showing butt welding and fillet welding as seen from the direction of arrows DD in FIG. 7; FIG.
FIG. 9 is a top view showing butt welding and fillet welding according to another embodiment of the present invention.
FIG. 10 is a top view showing butt welding and fillet welding according to still another embodiment of the present invention.
FIG. 11 is a diagram showing cracks due to shrinkage stress in butt welding and fillet welding.
12 is an enlarged view of a welded portion of a conventional fuel rack corresponding to FIG. 3 of the present invention.
13 is an EE arrow view of FIG.
14 is a cross-sectional view showing the plug welding of FIG.
15 is a cross-sectional view showing fillet welding of FIG.
16 is a view taken along the line FF in FIG.
17 is a GG arrow view of FIG.
[Explanation of symbols]
1 plate structure fuel rack base plate 2, 2A, 2B, 2C, 2D, 2E short partition plate 3, 3A, 3B, 3C, 3D long partition plate 4 protrusion 5 long partition plate groove 6 butt weld 7 fillet Weld 8 Back weld 9 Plug weld 10 Plug weld weld metal 11 Long partition bottom plate 12 Base material crack generated at the corner of the cut hole 13 Crack generated at the weld bead 14 Conventional protrusion 15 Cut hole 16 Corner of the cut hole 17 Clearance 18 Round 19 Shrinkage stress cracking of weld

Claims

In a structure having a cruciform joint assembled by inserting a protrusion of a short partition plate into a cut hole provided in the long partition plate, placing a second short partition plate thereon, and sequentially welding it. The starting end portion of the butt welding between the long partition plate and the protruding portion, and the starting end portion of fillet welding between the long partition plate and the second short partition plate are corner portions of the cut hole. A structure having a cruciform joint, characterized in that it does not overlap and overlap.

The long partition plate is provided with a plurality of cut holes, a protrusion that can be inserted into the cut hole is provided in the short partition plate, the protrusion is inserted into the cut hole from below, and then butt welding is performed. A structure having a cross joint for installing a second short partition plate from above and performing fillet welding between the long partition plate and combining the long partition plate and the short partition plate in a lattice shape In the method for assembling and manufacturing an article, a starting end portion of the butt welding between the long partition plate and the projection is welded away from a corner portion of the cut hole, and then the long partition plate and the second partition plate are welded. A method for assembling and manufacturing a structure having a cruciform joint, characterized in that an end portion of fillet welding with a short partition plate is welded away from the corner portion.

3. The method of assembling and manufacturing a structure having a cross joint according to claim 2, wherein a groove depth of the butt welding does not exceed 2/3 of a plate thickness of the long partition plate and the fillet welding is performed. A method for assembling and manufacturing a structure having a cross joint, characterized in that the leg length of the fillet weld is a leg length not exceeding 2/3 of the plate thickness of the long partition plate.

3. The method for assembling and manufacturing a structure having a cross joint according to claim 2, wherein the ends of the fillet weld and the butt weld are shifted so as not to coincide with each other. Assembly manufacturing method.

3. The method of assembling and manufacturing a structure having a cross joint according to claim 2, wherein a gap having a predetermined interval is provided between a corner portion at both ends of the cut hole and a protrusion portion inserted into the cut hole. A method for assembling and manufacturing a structure having a cross joint as a feature.

3. The method for assembling and manufacturing a structure having a cross joint according to claim 2, wherein the protrusion of the long partition plate is formed with a rounded portion of a predetermined radius or more at the root. Assembly manufacturing method.